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Sample records for sysmex uf-100 flow

  1. Automated flow cytometry compared with an automated dipstick reader for urinalysis.

    PubMed

    Langlois, M R; Delanghe, J R; Steyaert, S R; Everaert, K C; De Buyzere, M L

    1999-01-01

    Recently, the Sysmex UF-100 flow cytometer was developed to automate urinalysis. We compared UF-100 test results with those of an automated dipstick reader. A cross-check of UF-100, dipstick, and microscopic sediment data was performed in 1001 urine samples. Good agreements (P <0.001) were obtained between UF-100 and dipstick data for erythrocytes (r = 0.636) and leukocytes (r = 0.785). Even in urine with low conductivity, the UF-100 could detect lysed erythrocytes. The UF-100 bacterial count was higher among nitrite-positive urine samples (P <0.0001) and was positively correlated with the UF-100 leukocyte count (r = 0.745; P <0.001). In stored urine (24 h), bacterial counts increased, whereas the forward light scatter of leukocytes decreased (P <0.01). Casts and yeast cells reported by the UF-100 should be confirmed by microscopic review because false positives occurred. We suggest that a computer-assisted cross-check of UF-100 and dipstick data allows a clinically acceptable sieving system to reduce the workload of microscopic sediment urinalysis.

  2. Evaluation of the Sysmex UF1000i flow cytometer for ruling out bacterial urinary tract infection.

    PubMed

    De Rosa, Rita; Grosso, Shamanta; Bruschetta, Graziano; Avolio, Manuela; Stano, Paola; Modolo, Maria Luisa; Camporese, Alessandro

    2010-08-05

    Urine culture is one of the most frequently requested tests in microbiology, and it represents the gold standard for the diagnosis of UTIs. Considering the high prevalence of negative results and the long TAT of the culture test, the use of a rapid and reliable screening method is becoming more and more important, as it reduces the workload, the TAT of negative results, and above all, unnecessary antibiotic prescription. The Sysmex UF1000i is a new urine flow cytometry analyzer capable of quantifying urinary particles, including BACT, WBCs, and YLCs. To evaluate the analytical performance of the UF1000i as a method for ruling out UTIs, we examined 1349 urine samples and compared the UF1000i results with standard urine culture results. With instrument cut-off values of 170BACTx10(6)/L and 150WBCsx10(6)/L, we obtained a sensitivity of 98.8%, a specificity of 76.5%, a NPV of 99.5%, and four false negative results (1.2%), avoiding the culture of 57.1% of samples. The Sysmex UF1000i was capable of improving the efficiency of a routine microbiology laboratory by processing 100samples/h and providing negative results in a few minutes, thus reducing unnecessary testing with an acceptable number of false negative results. In addition, the preliminary evaluation of B_FSC and B_FLH parameters from bacteria histograms seems to be useful for the distinction of bacterial strains detected (Gram-negatives versus Gram-positives). In fact when B_FSC was less than 30 ch, it allowed the distinction of Gram-negative bacteria in 97% of the samples. Copyright 2010 Elsevier B.V. All rights reserved.

  3. HPC enumeration with the Sysmex XE-2100 can guide further flow cytometric CD34(+) measurements and timing of leukaphereses.

    PubMed

    Oelschlaegel, U; Bornhaeuser, M; Thiede, C; Ehninger, G; Hoelig, K

    2003-01-01

    The aim of this study was to evaluate whether HPC counts measured with the hematology analyzer can predict CD34+ levels in peripheral blood and in the apheresis product, as detected by standard flow cytometry. The main focus was the evaluation of HPC counts in poor mobilizers. Progenitor cell quantification was performed measuring HPC counts provided by the Sysmex XE-2100 hematology analyzer and CD34+ counts obtained in parallel by flow cytometry. Peripheral blood of patients who had received chemotherapy and G-CSF (142 measurements) and healthy donors mobilized with G-CSF alone (106 measurements) was investigated HPC counts in peripheral blood were also correlated with apheresis yield. HPC counts were significantly higher than CD34+ counts (3.5 fold inpatients and 1.7 fold in healthy donors, p= 0.0015). Our data indicate that HPC counts < or = 10/microL in pretreated patients predict a low probability of adequate CD34+ counts in peripheral blood and yields < 2 x 10(6)/kg in subsequent aphereses. Furthermore, repetitive low HPC enumerations in an individual were followed by insufficientCD34+ counts in peripheral blood or aphereses in 81% of investigations. In healthy donors low HPC counts (< or = 10/microL; 12/106 measurements) did not exclusively predict low CD34+ counts (median 23/microL). HPC counts can be used to schedule the start of CD34+ measurements(threshold > 10 HPC/microL) in patients mobilized after chemotherapy for autologous donation. Thus, expensive and time-consuming CD34+ enumerations can perhaps be minimized HPC measurements cannot completely replace flow cytometric CD34+ enumeration. In particular healthy stem-cell donors should be monitored with both methods to exclude false negative HPC measurements.

  4. Performance evaluation of the Sysmex haematology XN modular system.

    PubMed

    Briggs, Carol; Longair, Ian; Kumar, Punamar; Singh, Deepak; Machin, Samuel J

    2012-11-01

    The Sysmex XN haematology instrument performs automatic reflex testing, depending on sample results. A nucleated red blood cell (NRBC) count is provided on all samples. The instrument has a smaller footprint (34%) than previous Sysmex XE analysers. An evaluation comparing all results to the Sysmex XE-2100 and manual microscopic differential and morphology (n=390) was performed followed by a workflow study of 1000 samples to compare speed of operation and number of blood films reviews required from both systems. The new features on the instrument are: (1) white cell and NRBC channel, all samples include the NRBC count; (2) white cell precursor channel: false positive flags for blasts, abnormal lymphocytes and atypical lymphocytes are reduced significantly without a statistical increase of false negatives; (3) low white cell count mode: suggested setting of <0.5×10(9)/l. An extended count is more precise and provides an accurate differential. Fluorescent platelet count is performed in a dedicated channel. If the red cell or platelet size histograms are abnormal or if the platelet count is low, then a fluorescent platelet count is automatically performed. Good correlation with the XE-2100 and manual differential was found and the improved results compared to the reference flow cytometric analysis for platelet counts, especially below 30×10(9)/l (XE-2100, R(2)=0.500; XN, R(2)=0.875). The XN showed reduced sample turnaround time of 10% and reduced number of blood films for examination, 49% less than the XE-2100 without loss of sensitivity with more precise and accurate results on low cell counts.

  5. Evaluation of the SediMax automated microscopy sediment analyzer and the Sysmex UF-1000i flow cytometer as screening tools to rule out negative urinary tract infections.

    PubMed

    Íñigo, Melania; Coello, Andreu; Fernández-Rivas, Gema; Carrasco, María; Marcó, Clara; Fernández, Anabel; Casamajor, Teresa; Ausina, Vicente

    2016-05-01

    Urinary tract infections (UTI) are highly prevalent in nosocomial and community settings, and their diagnosis is costly and time-consuming. Screening methods represent an important advance towards the final UTI diagnosis, diminishing inappropriate treatment or clinical complications. Automated analyzers have been developed and commercialized to screen and rule out negative urine samples. The aim of this study was to evaluate two of these automated analyzers (SediMax, an automatic sediment analyzer and UF-1000i a flow cytometer) to predict negative urine cultures. A total of 1934 urine samples were analyzed. A very strong correlation for white blood cells (WBC) (rs: 0.928) and a strong correlation for bacteria (BAC) (rs: 0.693) were obtained. We also calculated optimal cut-off points for both autoanalyzers: 18 WBC/μL and 97 BAC/μL for SediMax (sensitivity=96.25%, specificity=63.04%, negative predictive value=97.97%), and 40 WBC/μL and 460 BAC/μL for UF-1000i (sensitivity=98.13%, specificity=79.16%, negative predictive value=99.18%). The use of SediMax and UF-1000i resulted in a 46.33% and 57.19% reduction of all samples cultured, respectively. In conclusion, both analyzers are good UTI screening tools in our setting.

  6. Flow Cytometry Analysis Using Sysmex UF-1000i Classifies Uropathogens Based on Bacterial, Leukocyte, and Erythrocyte Counts in Urine Specimens among Patients with Urinary Tract Infections

    PubMed Central

    Rydén, Patrik

    2014-01-01

    Urinary tract infections (UTIs) are the second most common bacterial infection. Urine culture is the gold standard for diagnosis, but new techniques, such as flow cytometry analysis (FCA), have been introduced. The aim of the present study was to evaluate FCA characteristics regarding bacteriuria, leukocyturia, and erythrocyturia in relation to cultured uropathogens in specimens from patients with a suspected UTI. We also wanted to evaluate whether the FCA characteristics can identify uropathogens prior to culture. From a prospective study, 1,587 consecutive urine specimens underwent FCA prior to culture during January and February 2012. Outpatients and inpatients (79.6% and 19.4%, respectively) were included, of whom women represented 67.5%. In total, 620 specimens yielded growth, of which Escherichia coli represented 65%, Enterococcus spp. 8%, Klebsiella spp. 7%, and Staphylococcus spp. 5%. For the uropathogens, the outcome of FCA was compared against the results for specimens with E. coli and those with a negative culture. E. coli had high bacterial (median, 17,914/μl), leukocyte (median, 348/μl), and erythrocyte (median, 23/μl) counts. With the exception of Klebsiella spp., the majority of the uropathogens had considerable or significantly lower bacterial counts than that of E. coli. High leukocyte counts were found in specimens with Staphylococcus aureus, Proteus mirabilis, Pseudomonas aeruginosa, and group C streptococci. Elevated erythrocyte counts were found for P. vulgaris, P. aeruginosa, and group C streptococci, as well as for Staphylococcus saprophyticus. In essence, FCA adds new information about the bacterial, leukocyte, and erythrocyte counts in urine specimens for different uropathogens. Based on FCA characteristics, uropathogens can be classified and identified prior to culture. E. coli and Klebsiella spp. have similar FCA characteristics. PMID:25472486

  7. Flow cytometry analysis using sysmex UF-1000i classifies uropathogens based on bacterial, leukocyte, and erythrocyte counts in urine specimens among patients with urinary tract infections.

    PubMed

    Monsen, Tor; Rydén, Patrik

    2015-02-01

    Urinary tract infections (UTIs) are the second most common bacterial infection. Urine culture is the gold standard for diagnosis, but new techniques, such as flow cytometry analysis (FCA), have been introduced. The aim of the present study was to evaluate FCA characteristics regarding bacteriuria, leukocyturia, and erythrocyturia in relation to cultured uropathogens in specimens from patients with a suspected UTI. We also wanted to evaluate whether the FCA characteristics can identify uropathogens prior to culture. From a prospective study, 1,587 consecutive urine specimens underwent FCA prior to culture during January and February 2012. Outpatients and inpatients (79.6% and 19.4%, respectively) were included, of whom women represented 67.5%. In total, 620 specimens yielded growth, of which Escherichia coli represented 65%, Enterococcus spp. 8%, Klebsiella spp. 7%, and Staphylococcus spp. 5%. For the uropathogens, the outcome of FCA was compared against the results for specimens with E. coli and those with a negative culture. E. coli had high bacterial (median, 17,914/μl), leukocyte (median, 348/μl), and erythrocyte (median, 23/μl) counts. With the exception of Klebsiella spp., the majority of the uropathogens had considerable or significantly lower bacterial counts than that of E. coli. High leukocyte counts were found in specimens with Staphylococcus aureus, Proteus mirabilis, Pseudomonas aeruginosa, and group C streptococci. Elevated erythrocyte counts were found for P. vulgaris, P. aeruginosa, and group C streptococci, as well as for Staphylococcus saprophyticus. In essence, FCA adds new information about the bacterial, leukocyte, and erythrocyte counts in urine specimens for different uropathogens. Based on FCA characteristics, uropathogens can be classified and identified prior to culture. E. coli and Klebsiella spp. have similar FCA characteristics.

  8. Analytic errors in Sysmex-generated hematology results in blood from a dog with chronic lymphocytic leukemia.

    PubMed

    Novacco, Marilisa; Martini, Valeria; Grande, Carmen; Comazzi, Stefano

    2015-09-01

    A blood sample from a 14-year-old dog was submitted to the veterinary diagnostic laboratory of the University of Milan for marked leukocytosis with atypical cells. A diagnosis of chronic T-cell lymphocytic leukemia (CLL) was made based on blood smear evaluation and flow cytometric phenotyping. A CBC by Sysmex XT-2000iV revealed a moderate normocytic normochromic anemia. Red blood cells counted by optic flow cytometry (RBC-O) resulted in a higher value than using electrical impedance (RBC-I). The relative reticulocyte count based on RNA content and size was 35.3%, while the manual reticulocyte count was < 1%. The WBC count of 1,562,680 cells/μL was accompanied by a flag. Manual counts for RBC and WBC using the Bürker chamber confirmed the Sysmex impedance results. Finally the manual PCV was lower than HCT by Sysmex. While Sysmex XT can differentiate between RBC and WBC by impedance, even in the face of extreme lymphocytosis due to CLL, RBC-O can be affected by bias, resulting in falsely increased RBC and reticulocyte numbers. Overestimation of RBC-O may be due to incorrect Sysmex classification of leukemic cells or their fragments as reticulocytes. This phenomenon is known as pseudoreticulocytosis and can lead to misinterpretation of regenerative anemia. On the other side PCV can be affected by bias in CLL due to the trapping of RBC in the buffy coat, resulting in a pink hue in the separation area. As HGB concentration is not affected by flow cytometric or other cell-related artifacts it may represent the most reliable variable to assess the degree of anemia in cases of CLL.

  9. Clinical laboratory automated urinalysis: comparison among automated microscopy, flow cytometry, two test strips analyzers, and manual microscopic examination of the urine sediments.

    PubMed

    Mayo, S; Acevedo, D; Quiñones-Torrelo, C; Canós, I; Sancho, M

    2008-01-01

    Urinalysis is one of the habitual clinical laboratory procedures, which implies that one of the largest sample volumes currently requires significant labor to examine microscopic sediments. Different analyzers currently used to perform this task have been compared with the manual microscopic sediment examination. The Atlas Clinitek 10 (Bayer Corporation, Diagnostics Division, Tarrytown, NY) and Urisys 2400 (Hitachi Science Systems Ltd., Ibaraki, Japan) test strips analyzers and two automated urinalysis systems, Sysmex UF-100 (Sysmex Corporation Kobe, Japan) and IRIS iQ200 (International Imaging Remote Systems, Chatsworth, CA), have been considered. We assessed the concordance between the results obtained from 652 freshly collected urine samples for erythrocytes (RBC), leukocytes (WBC), squamous epithelial cells (EC), nitrites/bacteria, and crystals using the methodologies mentioned. A principal components analysis was performed in order to examine the correlation between these parameters. Instrument accuracy was also assessed. The Spearman's statistic (p) showed an adequate agreement between methods for RBC (iQ200=0.473; UF-100=0.439; Atlas=0.525; Urisys=0.539), WBC (iQ200=0.695; UF-100=0.761; Atlas=0.684: Urisys=0.620), and bacteria/nitrites (iQ200=0.538; UF-100=0.647; Atlas=0.532; Urisys=0.561) counts. By applying the Wilcoxon and McNemar tests, a concordance degree was found between 82-99 and 52-95% for the values obtained from the two test strips analyzers considered and from the iQ200 and UF-100 systems, respectively. From these results, we can conclude that both test strips analyzers are similar and, on the other hand, that automated urinalysis is needed to improve precision and the response time; but sometimes manual microscopic revisions are required, mainly when flags, because of crystals, are detected.

  10. Automated detection of malaria with haematology analyzer Sysmex XE-2100.

    PubMed

    Mohapatra, Sarita; Samantaray, Jyotish C; Arulselvi, S; Panda, Jitender; Munot, Khushboo; Saxena, Renu

    2011-01-01

    Diagnosis of malaria is usually made by microscopy [Giemsa, Acridine Orange (AO), and Quantitative Buffy Coat (QBC) assay], which requires expertise. Currently, automated haematology analyzers are being used for complete blood count (CBC), in all acute febrile and non-febrile illnesses which simultaneously detects malaria. The normal scattergram by the analyzer (Sysmex 2100) comprises of five parameters i.e. lymphocytes (pink), monocytes (green), neutrophils (blue), eosinophils (red) with a space between the neutrophil and eosinophil populations. We carried out a prospective study to compare the efficacy of Sysmex XE-2100 (Sysmex Corporation, Kobe) for detection of malaria in comparison to other conventional techniques. 430 cases were analyzed for malaria by microscopy (QBC, AO, Giemsa), ICT (Immunochromatography) and flowcytometric analyzer (Sysmex XE-2100). The abnormal scattergrams were observed as double neutrophil, double eosinophil, grey zone, extended neutrophil zone with a decrease space between eosinophil and neutrophil, and a combination of above patterns. Out of 70 positive cases [49/70 (70%) P. vivax, 18/70 (25.7%) P. falciparum, and 3/70 (4.2%) both P. vivax and P. falciparum], 52 showed abnormal scattergrams by the analyzer. The sensitivity and specificity of hematology analyzer found to be 74.2% and 88%, respectively. Flowcytometric analyzer is a rapid, high throughput device which needs less expertization for the diagnosis of malaria. Hence, it can be used in the diagnostic laboratories as an early modality for diagnosis of malaria in suspected as well as clinically in apparent cases.

  11. New parameters available on Sysmex XE-5000 hematology analyzers contribute to differentiating dengue from leptospirosis and enteric fever.

    PubMed

    Oehadian, A; Michels, M; de Mast, Q; Prihatni, D; Puspita, M; Hartantri, Y; Sinarta, S; van der Ven, A J A M; Alisjahbana, B

    2015-12-01

    Distinguishing dengue virus infection from other febrile thrombocytopenic illnesses such as leptospirosis or enteric fever is important but difficult, due to the unavailability of reliable diagnostic tests. Sysmex XE-5000 hematology analyzers use fluorescence flow cytometry to quantitate new parameters including cells in the atypical lymphocyte area (AL), high-fluorescent lymphocyte counts (HFLC), immature granulocytes (IG), and immature platelets (IPF). This study aimed to investigate whether these parameters can help to discriminate between the diseases. We compared hematocytometry performed by a Sysmex XE-5000 analyzer in Indonesian adults with dengue (n = 93), leptospirosis (n = 11), and enteric fever (n = 6) infection, and in healthy controls (n = 28). Receiver operating characteristic curves comparing dengue and leptospirosis showed that dengue was characterized by increased %AL (AUC 0.87; 95% CI 0.70-1.03), %HFLC (AUC 0.89; 95% CI 0.78-0.99), and %IPF (AUC 0.81; 95% CI 0.65-0.97), while patients with leptospirosis had increased %IG (AUC 0.86; 95% CI 0.71-1.02). Low %AL, %HFLC, and %IG supported a diagnosis of enteric fever. The detection of AL, HFLC, IG, and IPF by Sysmex XE-5000 hematology analyzers can help to differentiate between common causes of febrile illnesses with thrombocytopenia in dengue endemic areas. We recommend further investigating the discriminatory value of these parameters in clinical practice. © 2015 John Wiley & Sons Ltd.

  12. Sysmex UF-1000i performance for screening yeasts in urine.

    PubMed

    Gutiérrez-Fernández, José; Riazzo, Cristina; Sanbonmatsu, Sara; de Dios Luna, Juan; Sorlózano, Antonio; Miranda, Consuelo; Navarro, José María

    2014-04-01

    We tested the capacity of the Sysmex UF-1000i system to detect yeasts in urine by screening a total of 22 132 urine samples received for culture in our microbiology laboratory during 1 year. We also analyzed different dilutions of previously filtered urine inoculated with a strain of Candida albicans. With clinical samples, a single cut-off point of 50 yeast-like cells (YLCs)/μL detected candiduria ≥10 000 colony forming units (CFU)/mL and >100 000 CFU/mL with a sensitivity of 87.3%/95.4%, a specificity of 97%, a negative predictive value of 95.9%, and a positive predictive value of 9.3%/5.7%. With the simulated samples, a linear relationship was observed between the dilution factor and the number of cells detected by UF-1000i. This instrument appears to be able to reliably rule out candiduria of a magnitude of at least 10 000 CFU/mL and facilitate urine sample screening, thereby providing fast results. The Sysmex UF1000i system can be adapted for candiduria screening by the use of an appropriate YLCs/μL cut-off point that takes account of the prevalence of candiduria in the population.

  13. [Erythrocytic parameters Sysmex in a case of severe haemolysis].

    PubMed

    Ferrero-Vacher, Corinne; Senlis, Jean-Éric; Loustaunau, Denis; Aquaronne, Danièle; Jeandel, Pierre-Yves; Sudaka, Isabelle

    2015-01-01

    We are reporting a case of severe haemolytic anemia with cold agglutinins which combines several spurious determinations. It shows the usefulness of the new erythrocytic parameters of the XE 5000 Sysmex, specially: red blood cells with optical count (RBC-O), GR-He (intra-erythocytic hemoglobin) and R-MFV (most frequent volume). Optical red blood cells act as a substitute for red cells count instead of impedance red cells and R-MFV as a substitute for MCV (mean cell volume). The hematocrit (HCT) is corrected thanks to the following formula: HCT=(RBC-O X R- MFV)/1000. Free plasmatic hemoglobin is included in the measure of hemoglobin by the analyzer but is not available for tissue oxygenation. So, hemoglobin (HGB) has to be corrected by the means of GR- He thanks to the following formula: HGB=(GR He x RBC-O)/10.

  14. Malaria detection with the Sysmex XE-2100 hematology analyzer using pseudoeosinophilia and abnormal WBC scattergram.

    PubMed

    Huh, Hee Jin; Oh, Gwi Young; Huh, Jung Won; Chae, Seok Lae

    2008-09-01

    Recent investigation using the Sysmex XE-2100 hematology analyzer (Sysmex Corporation, Japan) has demonstrated erroneously high eosinophil counts and abnormal white blood cell (WBC) scattergrams in malaria cases. This study was conducted to assess the diagnostic efficiency of the Sysmex XE-2100 analyzer for malaria. One hundred forty-four patients initially diagnosed with Plasmodium vivax infection, 319 patients with febrile illness, and 24 patients who underwent malaria treatment were analyzed. Atypical features on Sysmex XE-2100 analyzer were categorized as pseudoeosinophilia (a gap of more than 5% in eosinophil counts between the Sysmex XE-2100 analyzer and microscopic examination) and abnormal WBC scattergram. Pseudoeosinophilia or abnormal WBC scattergram were detected in 100 of 144 malaria-positive samples (sensitivity 69.4%, specificity 100%). The samples with pseudoeosinophilia or abnormal WBC scattergrams showed significantly higher parasite counts than the samples without pseudoeosinophilia or an abnormal WBC scattergram (P<0.05). All 24 samples from patients for whom the malaria smear was repeated after malaria treatment was initiated showed a normalized eosinophil count and a normal WBC histogram. In conclusion, attention to differential count and WBC scattergrams provided by the Sysmex XE-2100 would be a valuable tool in malaria detection.

  15. Performance evaluation of the Sysmex XS-1000i automated haematology analyser.

    PubMed

    Ghys, T; Malfait, R; VAN den Bossche, J

    2009-10-01

    The Sysmex XS-1000i is a compact new, fully automated haematology analyser, designed to generate complete blood counts with five-part leucocyte differential. In our study, a Sysmex XS-1000i instrument was evaluated according to Clinical Laboratory Standards Institute (CLSI) and International Council for Standardization in Haematology (ICSH) guidelines. Precision, carry-over and linearity were determined. Using a total of 700 patient samples, results from the Sysmex XS-1000i were compared with those from a Sysmex XE-2100, an Abbott Cell Dyn 4000 and the manual reference leucocyte differential. Using quality control material, total and within-run imprecision was less than 3% except for platelets. The system demonstrated good linearity over the entire reporting range and no carry-over (<0.5%). The Sysmex XS-1000i showed good correlation with XE-2100, CD-4000 and the manual reference leucocyte differential. Overall flagging sensitivity and specificity were 91% and 48%, respectively. In conclusion, the Sysmex XS-1000i demonstrated good analytical performance, is able to generate a complete blood count with five-part differential on low blood volumes and has considerable back-up capacity.

  16. Sysmex XT-2000iV scattergram analysis in a cat with basophilia.

    PubMed

    Stranieri, Angelica; Ferrari, Roberta; Zanzani, Sergio; Rossi, Gabriele

    2016-06-01

    A 13-year-old female Domestic Shorthair cat was presented to the Veterinary Teaching Hospital of the University of Milan for an interscapular mass suspected to be a mesenchymal malignant tumor. A preoperative CBC performed with Sysmex XT-2000iV showed leukocytosis with neutrophilia and eosinophilia. The Sysmex WBC/DIFF scattergram showed an additional, well-separated cluster of events between the neutrophil, eosinophil, and lymphocyte clusters. Blood smear evaluation revealed the presence of a significant number of basophils; thus, it was hypothesized that the additional cluster could represent the basophilic population. A second CBC, 24 days later, showed the same pattern on the WBC/DIFF scattergram in the absence of leukocytosis and neutrophilia. After surgical excision of the mass, a definitive diagnosis of feline injection site sarcoma was made. To the author's knowledge, there are no previous reports about the identification of feline basophils in the WBC/DIFF scattergram of Sysmex XT-2000iV.

  17. Comparison of abnormal cell flagging of the hematology analyzers Sysmex XN and Sysmex XE-5000 in oncohematologic patients.

    PubMed

    Furundarena, J R; Sainz, M; Uranga, A; Cuevas, L; Lopez, I; Zubicaray, J; Bizjak, A; Robado, N; Araiz, M

    2017-02-01

    Hematology analyzers should optimize flagging while minimizing false-negative results and unnecessary microscopic reviews. We compared flagging performance of Sysmex XE-5000 and XN analyzers in oncohematologic patients. Differential counts were performed by Cellavision digital system (100 cells) and a hematologist (another 100 cells). First, we included 292 samples (86 with blasts): 28 acute lymphoblastic leukemia, 88 acute myeloid leukemia, 91 myelodysplastic syndromes, 45 chronic myeloproliferative neoplasms, and 40 chronic myelomonocytic leukemia. Sensitivity, specificity and efficiency to detect blasts were 59.3%, 88.3%, and 79.8% for XE-5000 analyzer and 70.9%, 91.3%, and 85.2% for the XN analyzer. Then, we included 111 lymphoid malignancies. In 55 CLL XE-5000 flagged for Abn Lympho/L_Blasts?, XN flagged for Abn Lympho?. In one-third of 19 samples with splenic marginal lymphoma, none of the analyzers flagged. In 5 Sézary syndrome cases, XE-5000 triggered the Abn Lympho/L_Blasts? flag while the flagging in XN was less consistent: Abn Lympho? Blasts? and Atypical Lympho?. In 5 hairy cell leukemias, both analyzers only flagged one sample. In 13 myelomas, XE-5000 generated Atypical Lympho? flag; XN triggered more variable flags. In other lymphoid malignancies, flags were variable. XN analyzer generates less samples with false basophilia. XN analyzer has improved blast detection in oncohematologic patients. Operators cannot rely on the blast flag alone but have to consider other flags and hemogram data. In lymphoproliferative disorders, XN analyzer yields less samples with pseudobasophilia. Both analyzers must improve flagging for hairy cell leukemia. © 2016 John Wiley & Sons Ltd.

  18. Evaluation of the Sysmex pocH-1001 haematology analyser in an outdoor oncology service.

    PubMed

    Van Hecke, I; Vanden Bempt, I; Malfait, R; Van Den Bossche, J

    2010-01-01

    Since rapid blood count analysis as near patient testing is expanding, we evaluated the use of a Sysmex pocH-100i compact haematology analyser in an outdoor oncology setting according to the recently published International Council for Standardization in Haematology (ICSH) guidelines. In total, 838 blood samples from oncology patients were analysed by pocH-100i and re-analysed by a high-throughput haematology analyser for comparison (Abbott CD-4000 or Sysmex XE-2100) to evaluate in use imprecision, comparability and vote-outs. Imprecision was less than 5%, except for platelet enumeration in the low range (within-run imprecision 7%). Good comparability was found even for platelet enumeration in the low range (r2 = 0.82). Vote-outs were found in 10.6% of examined samples. In conclusion, the Sysmex pocH-100i demonstrates good imprecision conform with former publications, produces reliable results in normal and in lower ranges comparable to the results of high throughput haematology analysers. In a well controlled management plan the Sysmex pocH-100i is suitable for near patient testing in oncology.

  19. An evaluation of the Sysmex NE-8000 hematology analyzer.

    PubMed

    Hallawell, R; O'Malley, C; Hussein, S; Dauer, R J; Tanti, M; Wootton, A M; McGrath, K M

    1991-11-01

    The Sysmex NE-8000 is a new, fully automated hematology analyzer capable of providing a five-part white blood cell differential count and identifying abnormal specimens. This instrument was evaluated on 5,000 consecutive blood specimens and compared to the Coulter S Plus-IV analyzer and manual differential cell counts to determine the efficacy of its five-cell differential and screening capabilities. There was a high correlation between the commercial counters for the standard parameters, white blood cell count, red blood cell count, hemoglobin level, hematocrit, mean corpuscular volume, mean corpuscular hemoglobin concentration, and platelet count (r greater than 0.95), except for the mean corpuscular hemoglobin concentration (r = 0.51), for which the NE-8000 was considered the more accurate measurement. Precision and linearity studies were excellent. The white blood cell count, red blood cell count, hemoglobin level, and platelet count were reproducible on specimens stored at 4 degrees C or room temperature for 72 hours and the differential counts were reproducible for 12 hours. The correlations between automated and manual counts for neutrophils, eosinophils, basophils, and lymphocytes were excellent: r = 0.912, 0.945, 0.332, and 0.964, respectively. The monocyte correlation improved with software modification from 0.306 to 0.801. The NE-8000 gave accurate and reproducible differential counts for neutrophils, lymphocytes, and monocytes on specimens with white blood cell counts as low as 0.6 x 10(9)/1. The ability of the instrument to 'flag' abnormal specimens was excellent. The false-positive rate on normal samples was 1.8%, and the false-negative rate on known abnormal samples was 0.3%, due only to nonrecognition of a mild left shift. The identification of specific abnormalities was less precise. The NE-8000 is a powerful hematology analyzer that can perform a five-part white blood cell differential count accurately for a wide range of WBCs and reliably

  20. Performance evaluation of the Sysmex Cystatin C assay on the Roche Modular P Analyzer.

    PubMed

    He, Min; Ke, Pei-Feng; Xu, Jian-Hua; Chen, Wei-Ye; Lin, Hai-Biao; Zhang, Cheng; Wang, Yun-Xiu; Zhuang, Jun-Hua; Huang, Xian-Zhang

    2016-08-01

    Serum Cystatin C (CysC) is a promising endogenous marker for estimation of glomerular filtration rate. This study evaluated the analytical performance of the Sysmex CysC assay on the Roche Modular P Chemistry Analyzer (Modular P). The evaluation of imprecision, linearity, recovery, and interference were performed in accordance with the relevant Clinical and Laboratory Standards Institute guidelines protocols, using quality controls and patient samples. Comparison studies were conducted against the Siemens and Roche assay for CysC. At CysC concentrations of 0.45 and 1.80mg/L, the within-run coefficient of variations (CVs) were 2.81% and 2.04%, respectively, and the between-run CVs were 3.14% and 3.26%. The CysC assay was proven throughout the measuring range from 0.10 to 8.00mg/L. Good correlations were achieved among the 3 CysC assays. The Sysmex assay appeared to report higher results than the Siemens assay. No interference was detected from hemoglobin 5g/L, bilirubin (free or conjugated) 200mg/L, or chyle 1500 formazin turbidity units. The Sysmex CysC assay performed well with regard to basic performance, including precision, dilution linearity, and effects of interfering substances, and is an acceptable assay for the determination of CysC on the Modular P. Copyright © 2016 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

  1. Use of hematopoietic progenitor cell count on the Sysmex XE-2100 for peripheral blood stem cell harvest monitoring.

    PubMed

    Letestu, Rémi; Marzac, Christophe; Audat, Françoise; Belhocine, Ramdane; Tondeur, Sylvie; Baccini, Véronique; Garçon, Loïc; Cortivo, Liliane Dal; Perrot, Jean-Yves; Lefrère, François; Valensi, Françoise; Ajchenbaum-Cymbalista, Florence

    2007-01-01

    Successful peripheral blood stem cell (PBSC) collection depends on the timing of apheresis based on CD34+ cell enumeration. Because this analysis is expensive and induces organization difficulties, we evaluated hematopoietic progenitor cell (HPC) quantification on the Sysmex XE-2100 as a surrogate analysis. We tested 157 blood samples for CD34+ cells and HPC counts. We found a good linear correlation between HPC and CD34+ and determined simple rules allowing to use HPC count in daily practice. We set a positive cut-off >30 HPC/mm(3) for allowing PBSC harvest and a negative cut-off at 0 HPC/mm(3) for which collection should be delayed. These two situations accounted for 62% of cases and CD34+ cell count by flow cytometry confirmed HPC result in 95% of cases. Between 0 and 30 HPC/mm3, CD34+ enumeration is required for decision-making. We conclude that HPC count may be a useful surrogate for CD34+ enumeration in PBSC harvest monitoring.

  2. Performance evaluation of the Sysmex(®) XP-300 in an oncology setting: evaluation and comparison of hematological parameters with the Sysmex(®) XN-3000.

    PubMed

    van Dievoet, M A; Louagie, H; Ghys, T

    2016-10-01

    The Sysmex XP-300(®) (XP-300) is a new, fully automated hematology analyzer, designed to generate complete blood counts (CBC) with 3-part differential. In our study, the XP-300 was evaluated as a point-of-care (POC) analyzer in an oncology setting. In which blood samples from patients with different pathologies and treatments, affecting hematopoiesis, were analyzed. Performance was evaluated according to the International Council for Standardization in Haematology (ICSH) guidelines and CLSI protocol H20-A2 . Beside precision, linearity and carry-over, a comparison study with the Sysmex(®) XN-3000 (XN-3000) and a manual reference leukocyte differential was performed. Flagging performance was also evaluated. XP-300 showed excellent precision and linearity results. For within- and between-run precision, the criteria, according to Ricos et al. , were met for all parameters tested, except for platelets in the low level. Less than or equal to 0.5% carry-over was seen for all parameters tested. Comparison studies showed an acceptable correlation with both XN-3000 and the manual reference leukocyte count. A suboptimal flagging performance was demonstrated. In the context of diagnosing cytopenia due to myelosuppressing agents or leukocytosis due to infection, the XP-300 showed good analytical performance. However, in the thrombocytopenic range, precision was suboptimal. In follow-up of hematological malignancies with the occurrence of abnormal cells, we advise verification with a more advanced analyzer or with microscopic review, although further studies with a higher prevalence of abnormal cells are needed. © 2016 John Wiley & Sons Ltd.

  3. Evaluation and optimization of the Sysmex UF1000i system for the screening of urinary tract infection in primary health care elderly patients.

    PubMed

    Martín-Gutiérrez, Guillermo; Porras-González, Ana; Martín-Pérez, Carlos; Lepe, Jose Antonio; Aznar, Javier

    2015-05-01

    Urinary tract infections (UTIs) are a common problem in the elderly population. Urine culture is still considered the "gold standard" to diagnose infection in this population. However, urine cultures are laborious and costly, and most samples will yield no growth. An evaluation was made of the Sysmex UF-1000i flow cytometer as a screening tool for UTI in an elderly population older than 65 years who lived in the community, using 346 urine samples submitted for culture. The Receiver Operating Characteristic (ROC) analysis showed a significant difference (P<0.01) between 0.98 bacteria area under the curve value and 0.82 of white blood cells (WBC). The combination of both counts for screening did not show any improvement in specificity or sensitivity. According to our data, the use of a single cut-off point of 200bacteria/μL is suggested, in which the sensitivity and specificity were 99.11% and 91.59%, respectively, with a NPV of 99.49%. Moreover, this cut-off value could avoid 60.24% of the samples to be cultured, with a minimal false negative results rate of 0.87%. The stratification of age groups stratification helps in selecting a more adjusted Sysmex UF1000i cut-off limit, leading to an improvement in the screening parameters that would imply a better management of these infections, as well as a high reduction in the workload and cost savings. Copyright © 2014 Elsevier España, S.L.U. y Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.

  4. Validation of the Sysmex sp-1000i automated slide preparer-stainer in a clinical laboratory

    PubMed Central

    de Bitencourt, Eberson Damião dos Santos; Voegeli, Carlos Franco; Onzi, Gabriela dos Santos; Boscato, Sara Cardoso; Ghem, Carine; Munhoz, Terezinha

    2013-01-01

    Background The speed and quality of information have become essential items in the release of laboratory reports. The Sysmex®SP1000-I device has been developed to prepare and stain smear slides. However, for a device to be cleared for use in the laboratory routine it must pass through a validation process. Objective To evaluate the performance and reliability of the Sysmex® SP-1000i slide preparer-stainer incorporated into the routine of a hospital laboratory in Porto Alegre. Methods Peripheral blood samples of patients attending the laboratory for ambulatory exams with leukocyte counts between 7000/°L and 12,000/°L were evaluated, independent of gender and age. Two slides were prepared for each sample using the Sysmex® SP-1000i equipment; one of the slides was used to perform quality control tests using the CellaVision® DM96 device, and the other slide was used to compare pre-classification by the same device and the classification performed by a pharmacist-biochemist. Results The results of all the slides used as controls were acceptable according to the quality control test as established by the manufacturer of the device. In the comparison between the automated pre-classification and the classification made by the professional, there was an acceptable variation in the differential counts of leukocytes for 90% of the analyzed slides. Pearson correlation coefficient showed a strong correlation for band neutrophils (r = 0.802; p-value < 0.001), segmented neutrophils (r = 0.963; p-value < 0.001), eosinophils (r = 0.958; p-value < 0.001), lymphocytes (r = 0.985; p-value < 0.001) and atypical lymphocytes (r = 0.866; p-value < 0.001) using both methods. The red blood cell analysis was adequate for all slides analyzed by the equipment and by the professional. Conclusion The new Sysmex®SP1000-i methodology was found to be reliable, fast and safe for the routines of medium and large laboratories, improving the quality of microscopic analysis in complete blood

  5. The usefulness of blast flags on the Sysmex XE-5000 is questionable.

    PubMed

    Eilertsen, Heidi; Vøllestad, Nina K; Hagve, Tor-Arne

    2013-05-01

    Hematology analyzers generate suspect flags that involve microscopic reviews to confirm the presence of pathologic cells. This study investigated the reliability of the blast flag in a side-by-side evaluation of 3 Sysmex XE-5000 instruments (Sysmex, Kobe, Japan). The repeatability of the Q values reported by each instrument for 10 replicates of the same blood samples was low (intraclass correlation coefficient [ICC] values, 0.62-0.74). The reproducibility of the Q values obtained by analyzing 408 samples on all 3 instruments was reasonable (ICC value, 0.85). In addition, a systematic difference was observed among the instruments in the level of reported Q values. With cutoff commonly being 100, the observed reproducibility of the blast flagging among the instruments was evaluated as poor (κ = 0.73). Based on the observed low performances, we question the usefulness of the Q value as a predictor of blasts and whether a blast flag reported by the XE-5000 is sufficient as a criterion for performing a microscopic review.

  6. [Evaluation of the automated coagulation analyser Sysmex(®) CS-5100 (Siemens)].

    PubMed

    Martin-Toutain, Isabelle; Jobic, Lionel; Mancic, Tessy; Brissard, Alexandre; Ankri, Annick

    2015-01-01

    The Sysmex® CS-5100 is a fully automated multiparameter hemostasis analyzer equipped with a photo-optical clot detection unit, a cap-piercing system and a pre-analytical check screens for interfering substances such as bilirubin, lipids and haemolysis (HIL system). It is designed to perform coagulation tests as well as coagulometric, chromogenic and immunologic assays. The aim of the present study was to evaluate its performance. The intra-assay and inter-assay coefficients of variation (CV) were below 6% for most parameters both in the normal and in the pathological range (exceptions: intra-assay for severe factor VIII deficiency (CV = 7.4%) and for vWFRco (CV = 7.3% and 7.7%); and inter-assay for anti-Xa activity (CV = 8.8%) and vWFRco (9.3% and 11.1%). The measured lower limits of linearity for factor VIII and factor V were satisfactory. No sample or reagent carryover was detected in the conditions of the study. Our results demonstrated that using the Sysmex® CS-5100 analyzer, routine coagulation testing can be performed with satisfactory precision. This automate has the advantage of being connectable to an automation chain.

  7. Erroneously elevated immature reticulocyte counts in leukemic patients determined using a Sysmex XE-2100 hematology analyzer.

    PubMed

    Huh, Jungwon; Moon, Heewon; Chung, Whasoon

    2007-10-01

    The immature reticulocyte fraction (IRF) in peripheral blood, as determined by automated reticulocyte analysis, is calculated using the sum of medium and highly fluorescent reticulocyte numbers and provides information about erythropoietic activity in bone marrow. The purpose of this study was to investigate erroneously elevated IRF in leukemic patients, as determined using a Sysmex XE-2100 hematology analyzer (Sysmex, Kobe, Japan). Normal reticulocyte scattergram patterns show regions corresponding to reticulocytes located between matured RBCs and an upper particle (UPP) region, which show a continuum of non-separated fraction. The UPP represents erythroblasts and some immature reticulocytes. As a control group, peripheral blood was taken from patients with benign hematologic diseases, and their reticulocyte scattergrams all showed a normal pattern; UPP values were all less than 100. However, the reticulocyte scattergrams of 5 of 11 leukemia patients showed abnormal patterns and displayed a gap between RBC and reticulocyte regions. Three patients showed a flag with a message such as "RET Abn Scattergram". IRF results were elevated in these five patients, and their UPP values were above 100. For the remaining six leukemia patients with a normal reticulocyte scattergram pattern, immature reticulocytes were not markedly increased, and UPP values were less than 100. The findings of the present study demonstrate that IRF results may be erroneously elevated in leukemia patients and indicate that hematologists should examine reticulocyte scattergrams and UPP values carefully.

  8. Fragmented red cells reference range (Sysmex XN(®) automated blood cell counter).

    PubMed

    Lesesve, Jean-François; Daigney, Amandine; Henry, Sylvain; Speyer, Elodie

    2015-01-01

    Fragmented red cells (FRCs) is a new parameter automatedly determined by recent blood cell counters. Their count might be of interest because FRCs are supposed to reflect schistocytes counts measured on a stained peripheral blood smear observed under the microscope. But FRCs depend from the technical procedure used to detect them and thus reference ranges are device-dependent. The XN-9000(®) is one of the last model from Sysmex series. We aimed to establish reference range for FRCs, from 2389 controls. The mean ± SD was 0.32% ± 0.81, the median 0.02% (95% confidence interval ot the mean: 0.29-0.35%). We observed that the percentage of red blood cells with less than 17 pg of hemoglobin content (Hypo-He) was correlated to FRC increase, Hypo-He increase resulting in spurious FRCs majoration. FRCs reference range should be useful for: 1) laboratory staff in order to select which blood smears to check optically; 2) Sysmex company to set-up more optimal rules proposed with the counter (automated making of blood smear).

  9. Analysis of reticulocyte parameters on the Sysmex XE 5000 and LH 750 analyzers in the diagnosis of inefficient erythropoiesis.

    PubMed

    Urrechaga, E; Borque, L; Escanero, J F

    2011-02-01

    The reticulocyte hemoglobin equivalent (Ret He) represents an indirect measure of the functional iron available for erythropoiesis over the previous 2-3 days. Only the analyzers of a single manufacturer, Sysmex (Sysmex Corporation, Kobe, Japan), include Ret He. Red blood cell size factor (RSf) is a new parameter provided by Beckman Coulter, which joins together the volume of the erythrocytes and the volume of reticulocytes. The aims of the study were to investigate the clinical usefulness of RSf in the study of erythropoiesis status and to assess its concordance with Ret He values. Samples from 417 patients were run on both LH 780 (Beckman Coulter) and Sysmex XE 5000 analyzers. Independent samples t-test, Pearson correlation, receiver operating characteristic (ROC) analysis and inter-rater reliability (κ index) were applied. Good correlation between RSf and Ret He was observed, r = 0.8184. Significant differences (P < 0.001) were detected when groups with inefficient erythropoiesis were compared with patients undergoing therapy and healthy subjects. ROC analysis for RSf in the diagnosis of inefficient erythropoiesis, cutoff 91.1 fl, area under curve 0.963, sensitivity 91.7%, specificity 88.5%. Concordance between RSf and Ret He κ = 0.68. RSf and Ret He are suitable parameters for the assessment of erythropoiesis status.

  10. Evaluation of Sysmex XN-1000 hematology analyzer for cell count and screening of malignant cells of serous cavity effusion

    PubMed Central

    Xu, Weiyi; Yu, Qian; Xie, Lixia; Chen, Baode; Zhang, Ling

    2017-01-01

    Abstract Over the years, with the advancement in hematology analyzer technology, the use of fluid analysis method has seen a drastic increase in clinical examinations. Cell counting and classification in independent body fluid analysis method are conducted by semiconductor laser flow cytometry and nucleic acid fluorescence staining techniques. This study is to evaluate the efficacy of Sysmex XN-1000 hematology analyzer in cell counting and to screen malignant cells with serous cavity effusion. Specimens (N = 206) with serous cavity effusion from our hospital were included in this study. Manual and instrumental methods for cell counting, nucleated cell classification, and high-fluorescent cells (HFC) were used in this study. The correlation between RBC, nucleated cell count (NUC), the percentages of polymorphonuclear cell (PMN%), and mononuclear cells (MN%) was statistically analyzed using manual and instrumental methods. The regression equations of RBC, NUC, PMN%, and MN% in the manual and instrumental methods were RBC y = 0.88x + 426.4; NUC y = 0.85x + 33.4; PMN% y = 0.91x + 4.2; and MN% y = 0.91x + 5.1. Correlation coefficient R2 was 0.99, 0.98, 0.90, and 0.90 (P < .001). ROC curve analysis showed that when the cut-off value of HFC% was 4.4% and HFC# was 24.5/μL, area under curve (AUC), sensitivity, specificity, and 95% confidence interval were 0.707, 0.792, 0.558, 0.637–0.777; 0.708, 0.753, 0.550, 0.635–0.780, respectively. XN-1000 hematology analyzer body fluid method can accurately and rapidly count cell and nucleated cell classification with serous cavity effusion. HFC can indicate the possible existence of malignant cells; however, further investigations are required to validate its efficacy. PMID:28682907

  11. Investigation of morphological changes for the discrimination of nucleated red blood cells and other leukocytes in Sysmex XN hematology analyzer scattergrams using transmission electron microscopy.

    PubMed

    Kaido, Masako; Takagi, Yuri; Kono, Mari; Nakazawa, Fumie; Yamamoto, Shiori; Wada, Atsushi; Morikawa, Takashi

    2017-08-01

    The WNR channel of the XN-Series automated hematology analyzer (Sysmex) counts white blood cells (WBCs) and simultaneously performs a differential counting of basophils and nucleated red blood cells (NRBCs). The detection process involves exposing the cells to WNR-specific reagents containing an acidic detergent and a fluorescent dye and measuring the intensity of the forward scattered light (FSC) and side fluorescence light (SFL). We treated isolated peripheral WBCs and NRBCs with specific reagents and assessed the morphological changes in NRBCs and each leukocyte type using transmission electron microscopy (TEM). The results from a flow cytometer (FCM) showed that, after exposure to the reagents, basophils appeared on the highest FSC and SFL areas compared to other leukocytes on the WNR scattergram. Owing to the hemolysis of reticulocytes and erythrocytes, NRBCs that survived the reagent treatment could be distinguished by their lower intensity than those of the other leukocytes on the WNR scattergram. We investigated the significance of the relationship between the TEM and FCM results after the reagent treatment. We confirmed that the WNR channel differentiates the blood cells on the WNR scattergram based on differences in the amount of residual cytoplasm and nucleic acids.

  12. Fragmented red cells reference range for the Sysmex XN®-series of automated blood cell counters.

    PubMed

    Lesesve, J-F; Speyer, E; Perol, J-P

    2015-10-01

    Fragmented red cells (FRCs) are a new parameter determined automatically by the latest generation of blood cell counters. FRC counts may be of interest as they may reflect schistocyte counts measured on a stained peripheral blood smear observed under the microscope. However, FRC counts depend on the technical procedure used to detect them so that reference ranges are device dependent. The XN-9000® is one of the latest models from the Sysmex series of analysers. We aimed to establish a reference range for FRCs based on 1366 normal patient samples. The mean ± SD was 0.14 ± 0.35% and the median was 0% (95% confidence interval of the mean: 0.12-0.16%). We observed that the percentage of red blood cells with <17 pg of haemoglobin content (Hypo-He) was correlated to an FRC increase and that flagged results relating to red blood cells, reticulocytes or platelets might have presented with artefactually increased FRCs. The FRCs reference range (healthy subjects) should be useful for laboratory staff for selecting which blood smears to check optically. © 2015 John Wiley & Sons Ltd.

  13. Usefulness of thresholds for smear review of neutropenic samples analyzed with a Sysmex XN-10 analyzer.

    PubMed

    Ronez, Emily; Geara, Carole; Coito, Sylvie; Jacqmin, Hugues; Cornet, Edouard; Troussard, Xavier; Chatelain, Bernard; Mullier, François

    2017-10-01

    Neutropenia is one of the main criteria for a blood smear review. The objective of this study was to compare the thresholds proposed by the international consensus group for hematology review (1.0 10(9)/L) and the French speaking Group for Cellular Haematology (1.5 10(9)/L) in terms of the number of useless smears. We collected 112,097 analyzed samples from four laboratories equipped with XN instruments (Sysmex, Kobe, Japan) during early 2016. The only exclusion criterion was a leucocyte count below 0.5 10(9)/L. In the absence of abnormal cells and/or morphology suggesting haematological disease, samples were classified as 'negative for morphology' and the differential from the XN-10 was reported. These smear procedures were considered as uninformative. Some 2202 samples met the criterion for neutropenia (<1.5 10(9)/L) for slide review representing 1.96% of the total. These included 1031 with neutropenia alone and 1171 neutropenia plus other abnormalities. Of the 1031 with neutropenia alone, 886 had a neutrophil count between 1.0 10(9)/L and 1.5 10(9)/L. The smear was uninformative for all of these samples. In conclusion, microscopic examination of a blood smear provided very limited information in cases of neutropenia without other abnormalities.

  14. Performance evaluation of the automated nucleated red blood cell enumeration on Sysmex XN analyser.

    PubMed

    Tantanate, C; Klinbua, C

    2015-06-01

    Presence of peripheral blood nucleated red blood cell (NRBC) is associated with pathological conditions and leads to the overestimation of white blood cell count in automated haematology analysers (HA). The authors evaluated NRBC enumeration by a new HA Sysmex XN (XN) to demonstrate the precision and comparability to manual count (MC) at the various NRBC values. Specimens with initially NRBC positive were included. For precision assessment, 8 levels of NRBCs were repeatedly analysed. For comparison study, 234 specimens were analysed by both XN and MC. For precision study, the percentage of coefficient of variation ranged from 14% to 45.6% and 1.2% to 4.4% for MC and XN, respectively. For comparison study between XN and MC, NRBCs ranged from 0% to 612.5%. Regression analysis demonstrated an r(2) of 0.98. The mean bias of 14.1% with 95% limits of agreement between -48.76% and 76.95% was found. The NRBC counts from XN appeared to be more in accordance with MC when the NRBCs were lower than 200% with the concordance rate of 94.2%. The automated NRBC enumeration by XN was precise and could replace the traditional MC, especially for the specimens with NRBCs lower than 200%. © 2014 John Wiley & Sons Ltd.

  15. Two cases of false platelet clumps flagged by the automated hematology analyzer Sysmex XE-2100.

    PubMed

    Dai, Qingkai; Zhang, Ge; Lai, Chunqi; Du, Zeli; Chen, Lan; Chen, Qi; Peng, Leiwen; Wang, Yuefang; Yang, Hui; Ye, Lei; Yang, Xianjun; Jiang, Yongmei

    2014-02-15

    Automated hematology analyzer is widely used by clinical laboratories to examine blood cell counts and differential leukocyte counts. However, a microscopic examination of a well-prepared blood film is still necessary and useful in most cases. Two patients with severe disease were required complete blood counts (CBC) after admission at West China Second University Hospital in Southwest China. A false "platelet clumps?" flag was generated by the automated hematology analyzer Sysmex XE-2100. However, when the well-prepared blood film was reviewed, there was echinocytosis rather than clumps of platelets. In addition, both patients had severe metabolic acidosis with arterial blood pH <7.00 and HCO3- <4 mmol/l. On day 2 of admission, the false platelet clumps flags were not presented in both cases. Our further results suggested that the false platelet clumps had been flagged probably due to the influence of the extremely low blood pH. These two cases emphasized that a microscopic examination of a blood film was central to the morphology of blood cells. When the result of microscopic examination was abnormal, it was suggested that the physician should consider further testing to find underlying condition. Copyright © 2013 Elsevier B.V. All rights reserved.

  16. Local verification between the hematological analyzers Sysmex XN-series and XE-5000.

    PubMed

    Pérez, I; Redín, M E; Vives, A; Garrido, A; Urrechaga, E; Lacasta, M

    2016-06-01

    The aim of this study was to perform a verification of the hematology analyzer Sysmex XN-2000 by comparing with the previous XE-5000. This study assessed the precision and carryover on the XN-2000 and the systematic error between the both counters according to desirable biological variability criterion and a flag comparison study. Within-run precision and between-batch precision were measured according to the ICSH guidelines. A comparative study was performed analyzing two hundred and six samples of peripheral blood from patients. The statistical study was conducted using the Passing-Bablok and Bland-Altman analyses. The leucocyte flag comparison was made by measuring the efficiency rate. Between-batch precision was lower than that recommended by the biological variability criterion and manufacturer specifications. The comparison gave nonagreement results for neutrophil and basophil counts according to the criterion of biological variability. Erythroblasts and immature granulocytes showed nonagreement, but there is no available biological variation database for these parameters to compare with. Nevertheless, excellent absolute agreement was found for red blood cell parameters, and for platelet, lymphocyte, monocyte, and eosinophil counts. The global results obtained for the precision, comparability, and efficiency provide a satisfactory integration of the XN-2000 in the core laboratory routine and accomplish an optimal reliability. © 2016 John Wiley & Sons Ltd.

  17. Sample stability for complete blood cell count using the Sysmex XN haematological analyser

    PubMed Central

    Daves, Massimo; Zagler, Elmar M.; Cemin, Roberto; Gnech, Flora; Joos, Alexandra; Platzgummer, Stefan; Lippi, Giuseppe

    2015-01-01

    Background Sample stability is a crucial aspect for the quality of results of a haematology laboratory. This study was conducted to investigate the reliability of haematological testing using Sysmex XN in samples stored for up to 24 h at different temperatures. Materials and methods Haematological tests were performed on whole blood samples collected from 16 ostensibly healthy outpatients immediately after collection and 3 h, 6 h or 24 h afterwards, with triple aliquots kept at room temperature, 4 °C or 37 °C. Results No meaningful bias was observed after 3 h under different storage conditions, except for red blood cell distribution width (RDW) and platelet count (impedance technique, PLT-I) at 37 °C. After 6 h, meaningful bias was observed for mean corpuscular haemoglobin (MCH) and mean corpuscular volume (MCV) at room temperature, red blood cell (RBC) count, mean corpuscular haemoglobin concentration (MCHC), MCH, MCV and PLT-I at 4 °C, and RBC, RDW, MCHC, MCH and PLT-I at 37 °C. After 24 h, a meaningful bias was observed for MCHC, MCV, platelet count (fluorescent technique, PLT-F) and mean platelet volume (MPV) at room temperature, MCHC, MCV, PLT-I and MPV at 4 °C, and all parameters except RBC count and MPV at 37 °C. Discussion Great caution should be observed when analysing results of haematological tests conducted more than 3 h after sample collection. PMID:26057491

  18. Cell analysis in cerebrospinal fluid (CSF) using Sysmex® hematology analyzers XT-4000i and XE-5000: evaluation with CSF controls of the Joint German Society for Clinical Chemistry and Laboratory Medicine (DGKL).

    PubMed

    Kleine, Tilmann O; Nebe, Carl Thomas; Löwer, Christa; Geilenkeuser, Wolf-Jochen; Dorn-Beineke, Alexandra

    2012-03-01

    In cerebrospinal fluid (CSF) analysis, hematology analyzers (HAs) Sysmex® XT-4000i and XE-5000, equipped with flow cytometry (FCM), were used to count cells and differentiate leukocytes into mononuclear and polymorphonuclear cells (MNCs, PMCs) applying body fluid mode. FCM was evaluated with 20 DGKL CSF controls containing viable human leukocytes and erythrocytes. HA values were compared with reference values by Passing/Bablok regression analysis to reveal conformity. Conformity of white blood cells (WBCs) was obtained with native leukocytes, counted in calibrated Fuchs-Rosenthal chamber as reference; red blood cell counts proved inaccurate. CV <40% with WBC counts <20 per μL impairs accuracy. Reference WBC differentiation was assayed using FACS Canto II™ and FC-500 SN with anti-CD45, anti-CD14, anti-CD16, anti-CD16/56 [Becton Dickinson (BD); Beckman Coulter (BC)]. BD FACS lysing solution®-no-wash-procedure was applied. BC pretreatment with Versalyse lysing solution was not recommended. MNCs (lymphocytes + monocytes) were significantly lower (∼14%) on both HAs; PMCs (granulocytes or sum of neutrophils + eosinophils + basophils: range 1-86 M/L) were significantly higher (∼2.2-fold). WBC HA differentiation is not reliable because MNC/PMC differentiation yielded lower and higher values than FACS-FCM references, respectively. This is attributed to incorrect discrimination of leukocytes with rounded/nonrounded nuclei; adding leukocytes with nonrounded nuclei to too low HA MNCs (about 40% not-activated) yielded P/B conformity; subtraction of leukocytes with nonrounded nuclei from elevated HA PMCs showed conformity (about 85% activated). Nucleus/activation state of leukocytes was assessed using microhistology. Sysmex XT-4000i and XE-5000 HAs systems are inappropriate for complete CSF cell analysis. Copyright © 2012 International Society for Advancement of Cytometry.

  19. Performance evaluation of the Sysmex XE-5000 hematology analyzer for white blood cell analysis in cerebrospinal fluid.

    PubMed

    Perné, Andrea; Hainfellner, Johannes A; Womastek, Irene; Haushofer, Alexander; Szekeres, Thomas; Schwarzinger, Ilse

    2012-02-01

    The newest generation hematology analyzer, Sysmex XE-5000 (Sysmex Corporation, Kobe, Japan) is equipped with an improved body fluid analysis mode. To evaluate the applicability of the XE-5000 analyzer to white blood cell (WBC) analysis in cerebrospinal fluid (CSF). A total of 425 routinely collected, consecutive CSF samples were included in the study. For a comparison of total WBC counts, the results of routine chamber counts were grouped into categories of 0 to 5 (n  =  330), >5 to 10 (n  =  36), >10 to 50 (n  =  39), >50 to 200 (n  =  15), and >200 (n  =  5) WBC/µL. Microscopic differential counts were performed using cytospins from 276 samples. Results were grouped according to the percent content of polymorphonuclear (PMN) cells, 0% to 25% (n  =  263), >25% to 50% (n  =  7), >50% to 75% (n  =  3), and >75% to 100% (n  =  3) of WBC. Corresponding results of XE-5000 analysis were matched to these particular count categories. For total WBC counts, the proportions of samples correctly classified by the XE-5000 from the percentage groups described above were 88%, 47%, 72%, 93%, and 100%, respectively. After the two lowest count categories were combined into one range of 0 to 10 WBC/µL, matches increased to 95%. For PMN counts in the 0% to 25% group, 37% of samples were misclassified by the XE-5000. Conversely, for samples with microscopic PMN counts of more than 25%, there was a trend toward underestimation by the XE-5000. Mismatches were most pronounced in samples with fewer than 10 WBC/µL. The Sysmex XE-5000 hematology analyzer yields valid total CSF cell counts and may be considered an acceptable alternative to the traditional chamber method, even for samples with low WBC counts. However, it cannot be recommended as a suitable alternative for manual differential cytologic workup.

  20. Hypo- and hypernatremia results in inaccurate erythrocyte mean corpuscular volume measurement in vitro, when using Sysmex XE 2100.

    PubMed

    Philipsen, Jens Peter; Madsen, Kirsten Vikkelsø

    2015-11-01

    Automated hematology analyzers dilute patient erythrocytes with an isoosmotic diluent before quantitating the erythrocyte mean cell volume (MCV). However, if patient plasma osmolality differs from the diluent, water will cross the erythrocytes membrane and establish a new equilibrium across the membrane. Since the new equilibrium is reached before the measurement of the MCV, the measured MCV may not reflect the true MCV in vivo. Calculation of the theoretical change in MCV at changed P-Sodium/P-Osmolality and to investigate if the automated blood cell counter Sysmex XE 2100 measures MCV correctly in hypo- and hyperosmolality and hypo-and hypernatremia. In addition, to examine whether the theoretically calculated change in MCV corresponds with the experimentally determined MCV change. Theoretical calculation of the MCV inaccuracy at hypo- and hypernatremia, as well as at hypo- and hyperosmolality. Experimental studies with comparison of MCV measured at Sysmex XE 2100 to MCV found by using the manual measured packed cell volume method. Measurement of MCV in hypo- and hypernatremia patients using the automated blood cell counter Sysmex XE 2100 resulted in inaccurate MCV. The experimental results also revealed a strong correlation between P-Osmolality/P-Sodium and MCV inaccuracy (R(2) = 0.70/0.85) similar to the theoretically calculated MCV inaccuracy. We suggest using mean cellular Hb (MCH) instead of MCV, mean corpuscular Hb concentration (MCHC) and B-Erythrocyte volume fraction (EVF). Alternatively, we suggest standardizing the measured MCV to a normal P-Sodium e.g. 140 mmol/L to estimate the in vivo MCV.

  1. Performance evaluation of the white cell precursor channel on the Sysmex XN hematology analyzer in HIV specimens.

    PubMed

    Schapkaitz, Elise; Khoza, Phoyisile

    2017-09-26

    Automated hematology analyzers generate white blood cell (WBC) suspect flags to indicate smears requiring manual review. In a human immunodeficiency virus (HIV) patient population with a high frequency of abnormal specimens, the usefulness of these flags depends on their sensitivity and specificity. The white cell precursor (WPC) channel on the Sysmex XN-9000 analyzer (Sysmex Corporation, Kobe, Japan) has recently been introduced in order to distinguish immature cells such as blasts and abnormal lymphocytes. The efficiency of the flags generated by WPC reflex testing was compared to the white cell differential (WDF) on the Sysmex XN-9000 in 400 routine HIV samples. A flag was generated by the WDF channel in 346 (86.50%) samples. Addition of the WPC to the WDF resulted in a 20.99% reduction in the smear review rate. WPC analysis correctly identified the initial WDF flag in 59 (60.82%) samples with 'blasts?' or 'abnormal lympho?' flags. WPC showed an excellent sensitivity of 100%. However, the specificity remained poor. On investigation, samples with chronic infection/inflammation (35.00%) and lymphopenia (63.25%) were associated with a high false positive rate of 76.32% and 55.56%, respectively. WPC analysis removed 45 (51.72%) coexisting 'atypical lympho?' false positive WDF flags. The 'atypical lympho?' flag showed an increased sensitivity and specificity of 88.46% and 74.67%, respectively. White cell precursor reflex testing showed improved flagging efficiency for the 'atypical lympho?' flag, which was a good indicator of reactive lymphocytes during chronic infection/inflammation. Nevertheless, the false positive rate for 'abnormal lympho/blasts?' was high in the presence of lymphopenia and infection. © 2017 Wiley Periodicals, Inc.

  2. Evaluation of the Flagging Performance of the Hematology Analyzer Sysmex XN Series on the Basis of "Q Values".

    PubMed

    Kweon, Oh Joo; Lee, Mi-Kyung; Kim, Hye Ryoun

    2017-08-31

    - In the XN series of hematology analyzers (Sysmex, Kobe, Japan), the probability of the presence of abnormal cells is indicated by flags based on Q values. - To evaluate the Q values performance of the Sysmex XN-20 modular analyzer. - The interinstrumental concordance, intrainstrumental precision, and diagnostic accuracy of Q values, with tested flags of "blasts/abnormal lymphocytes," "atypical lymphocytes," and "blasts," were investigated. - Absolute concordance rates in flagging between 2 analyzers ranged from 69.8% to 80.8%, and κ values ranged from 0.43 to 0.61. In samples with absolute related cell counts lower than 100/μL, the values ranged from 0.31 to 0.52. For intrainstrumental precision, standard deviations ranged from 4.8 to 23.9 for the blasts/abnormal lymphocytes, from 18.7 to 59.1 for the blasts, and from 11.0 to 23.0 for the atypical lymphocytes. Using a default Q value cutoff, diagnostic accuracy values based on the area under the curve, sensitivity, and specificity were, respectively, 0.910, 90.9%, and 72.2% for blasts/abnormal lymphocytes; 0.927, 84.9%, and 89.8% for blasts; and 0.865, 74.4%, and 84.9% for atypical lymphocytes. The diagnostic accuracy of Q values was much lower in samples with absolute related cell counts lower than 100/μL than in those 100/μL or higher. - Q values of the Sysmex XN-20 analyzer were found to be imprecise and irreproducible, especially with samples containing a small number of pathologic cells. Adjustments in the Q value threshold may help in the detection of these cells.

  3. Comparison of the Sysmex XT-2000iV with microscopic differential counts of canine bone marrow.

    PubMed

    Pernecker, Iris; Bauer, Natali B; Johannes, Sigrid; Ginder, Melanie; Harleman, Johannes H; Moritz, Andreas

    2017-03-01

    Canine bone marrow is frequently assessed in the advanced preclinical research environment. Automated analysis provides time savings and objectivity over the gold standard of microscopic (cytologic) evaluation. We compared the analysis of 90 canine bone marrow samples by the Sysmex XT-2000iV hematology analyzer (Sysmex Corp., Kobe, Japan) with cytologic evaluation. Gates for cell populations were created in the system's WBC/BASO channel. Variables "total nucleated red blood cells" (total_NRBC), "poly- and orthochromatic nucleated red blood cells" (poly_orth_NRBC), "total neutrophils" (total_NEUT), "mature neutrophils" (mature_NEUT), and myeloid-to-erythroid (M:E) ratio were compared with cytologic evaluation. Intra-assay repeatability and total error (TE) were calculated for both methods. Intra-assay repeatability was 0.95-2.48% for the XT-2000iV and 8.32-23.23% for cytology. Observed TE for the automated measurement was 5.16-46.8% and for cytology 22.70-76.74%. Spearman rank correlation was excellent for M:E ratio (0.91) and fair for the other populations (0.65-0.71). Absolute bias for M:E ratio was low (-0.114). A negative absolute bias of -7.71% for the XT-2000iV was found for poly_orth_NRBC, whereas the bias was positive for total_NEUT (7.10%) and mature_NEUT (14.67%). M:E ratio of canine bone marrow samples can be precisely determined using the Sysmex XT-2000iV WBC/BASO channel. Total_NRBC, poly_orth_NRBC, total_NEUT, and mature_NEUT can be estimated rapidly. With distinctly lower coefficient of variation and observed TE compared with cytology, automated measurement provides advantages in terms of standardization, and it is suited to the advanced preclinical research environment where large numbers of samples are investigated.

  4. Identification of spurious hemolysis in anticoagulated blood with Sysmex XE-2100 and Siemens Advia 2120.

    PubMed

    Lippi, Giuseppe; Pipitone, Silvia; Gennari, Daniela; Franchini, Massimo

    2012-01-01

    Various degrees of hemolysis might occur during collection, processing and storage of blood bags or blood tubes for hematological testing. In both circumstances, the identification of hemolysis is challenging since the centrifugation process is not required. The aim of this study was to identify simple hematological parameters that would help identify the presence of hemolysis in anticoagulated blood. Twenty tubes containing K2EDTA anticoagulated blood were randomly selected from outpatient samples and divided in two aliquots. The former was immediately analyzed, whereas the latter was subjected to mechanical hemolysis by aspirating whole blood two times through a very fine needle to generate mechanical hemolysis. Both aliquots were tested on Advia 2120 and Sysmex XE-2100. The double aspiration of the blood through the fine needle caused a remarkable hemolysis with significant decrease of red blood cell (RBC) count (-17 +/- 11%; p < 0.01), hematocrit (-18 +/- 12%; p < 0.01) and reticulocytes (-24 +/- 13%; p < 0.01), but not of hemoglobin, white blood cell or platelet counts. A remarkable increase of immature platelet fraction (IPF) on XE-2100 and RBC ghosts on Advia 2120 was observed in the hemolyzed samples, whereas RBC fragments did not vary significantly. A significant correlation was also observed between hemolysis and reticulocyte count (r = 0.823; p < 0.01), IPF (r = -0.502, p = 0.024) and RBC ghosts (r = -0.711; p < 0.01). Receiver Operating Characteristic (ROC) curve analysis demonstrated a good performance of both IPF and RBC ghosts (i.e., AUCs 0.91 and 0.96, respectively) for distinguishing non-hemolyzed from hemolyzed specimens. The absolute values of both IPF and RBC ghosts perform efficiently for distinguishing hemolyzed from non-hemolyzed specimens, although neither reached 100% sensitivity and specificity. Nevertheless, the demonstration that both parameters significantly increase after hemolysis can be reliably used to distinguish hemolyzed from non

  5. Automated five-part white blood cell differential counts. Efficiency of software-generated white blood cell suspect flags of the hematology analyzers Sysmex SE-9000, Sysmex NE-8000, and Coulter STKS.

    PubMed

    Thalhammer-Scherrer, R; Knöbl, P; Korninger, L; Schwarzinger, I

    1997-06-01

    The present study evaluates the efficiency of software-generated white blood cell (WBC) "suspect flags" of the hematology analyzers Sysmex SE-9000, Sysmex NE-8000, and Coulter STKS. Automated WBC differential counts were considered positive if they contained any suspect WBC flag indicating the presence of blasts, myeloid precursor cells, or abnormal lymphocytes. Reference differential counts were performed by microscopic examination of 400 WBCs per sample. After comparison to the reference method, automated differential counts were classified as true-positive, true-negative, false-positive, and false-negative. The flagging efficiency of analyzers was expressed as a percentage of subjects correctly classified. Four hundred sixty-seven blood samples were randomly chosen for comparison analysis from various inpatient and outpatient departments of the Vienna university hospital, Austria. The efficiency rates of flagging for the presence of > or = 1% abnormal WBCs were 78% (SE-9000), 77% (NE-8000), and 72% (Coulter STKS). The flagging efficiencies were best for samples with normal WBC counts. With regard to the specific suspect flags, the flagging of blast cells was most efficient on all analyzers. Our results demonstrate the comparable overall performance of three analyzers, SE-9000, NE-8000, and Coulter STKS. They further underscore the importance of critical interpretation of automated differential counts, because at a detection limit of > or = 1% abnormal WBCs > 20% of samples were not correctly flagged by either analyzer.

  6. Performance evaluation of the Abbott CELL-DYN Ruby and the Sysmex XT-2000i haematology analysers.

    PubMed

    Leers, M P G; Goertz, H; Feller, A; Hoffmann, J J M L

    2011-02-01

    Two mid-range haematology analysers (Abbott CELL-DYN Ruby and Sysmex XT-2000i) were evaluated to determine their analytical performance and workflow efficiency in the haematology laboratory. In total 418 samples were processed for determining equivalence of complete blood count (CBC) measurements, and 100 for reticulocyte comparison. Blood smears served for assessing the agreement of the differential counts. Inter-instrument agreement for most parameters was good although small numbers of discrepancies were observed. Systematic biases were found for mean cell volume, reticulocytes, platelets and mean platelet volume. CELL-DYN Ruby WBC differentials were obtained with all samples while the XT-2000i suppressed differentials partially or completely in 13 samples (3.1%). WBC subpopulation counts were otherwise in good agreement with no major outliers. Following first-pass CBC/differential analysis, 88 (21%) of XT-2000i samples required further analyser processing compared to 18 (4.3%) for the CELL-DYN Ruby. Smear referrals for suspected WBC/nucleated red blood cells and platelet abnormalities were indicated for 106 (25.4%) and 95 (22.7%) of the XT-2000i and CELL-DYN Ruby samples respectively. Flagging efficiencies for both analysers were found to be similar. The Sysmex XT-2000i and Abbott CELL-DYN Ruby analysers have broadly comparable analytical performance, but the CELL-DYN Ruby showed superior first-pass efficiency. © 2010 Blackwell Publishing Ltd.

  7. Do the flags related to immature granulocytes reported by the Sysmex XE-5000 warrant a microscopic slide review?

    PubMed

    Eilertsen, Heidi; Hagve, Tor-Arne

    2014-10-01

    The Sysmex XE-5000 instruments (Sysmex, Kobe, Japan) count immature granulocytes (IGs) and use the "Imm Gran?" flag to signal unreliable results. This study investigated the usefulness of the "Imm Gran?" flag and the analytical and diagnostic performance of the IG measurements in a side-by-side evaluation. In total, 408 samples were analyzed on three XE-5000 instruments. The IG count and the "Imm Gran?" flag reports from all three instruments were used for reproducibility studies. The diagnostic performance of the automated IGs and the "Imm Gran?" flag were studied by comparing the XE-5000 results with the results of the manual differential. The reproducibility of the "Imm Gran?" flagging between instruments was poor (қ, 0.75-0.80). The most significant contributor to the report of the "Imm Gran?" flag was bands, and the flag played a minor role in detecting blasts. The interinstrument reproducibility of the IG counts was high (intraclass correlation, 0.99). The IG count reported by XE-5000s was higher than the manual IG count (36%-55%), and the difference and the variability tended to increase with increasing levels of IGs. The "Imm Gran?" flag has a poor analytical quality and gives no substantial information on the presence of blasts in the sample. We therefore suggest reporting the automated IG count without initial microscopic slide review. Copyright© by the American Society for Clinical Pathology.

  8. Clinical application and evaluation of Sysmex XE-5000 analyser for detecting nucleated red blood cells in peripheral blood.

    PubMed

    Zheng, Shan-Luan; Zheng, Tian; Cheng, Xiang; Hao, Xiao-Ke

    2014-01-01

    To evaluate the performance of Sysmex XE-5000 analyser for detecting nucleated red blood cells (NRBCs) in peripheral blood and investigate the clinical application of this analyser. The absolute NRBC counts (NRBC#) and percentage (NRBC%) of 137 blood specimens (NRBC-positive according to the DIFF channel of the analyser) were determined in the NRBC channel of the analyser. The intra-assay imprecision, carryover rate, and linear range of the analyser were evaluated. The NRBC% of the blood sample was detected with a microscope, and the difference between two methods was analysed. The intra-assay imprecision of the analyser for detecting NRBC# in specimens with high, moderate, and low Q-flag values were 2.10%, 3.26%, and 11.62%, respectively, and the imprecision for detecting NRBC% were 3.79%, 5.80%, and 13.33%, respectively. The carryover rates of the analyser for detecting NRBC# and NRBC% were 0.51% and 0.26%, respectively. Sysmex XE-5000 analyser had good linearity in NRBC# (i.e., 0/L to 18 x 10(9)/L). The NRBC%s of the two methods did not significantly differ (p = 0.716). The analyser can completely replace the traditional microscope for clinically classifying and counting NRBCs.

  9. Use of Sysmex XE-2100 and XE-5000 hematology analyzers for the diagnosis of malaria in a nonendemic country (France).

    PubMed

    Dubreuil, P; Pihet, M; Cau, S; Croquefer, S; Deguigne, P A; Godon, A; Genevieve, F; De Gentile, L; Zandecki, M

    2014-04-01

    Most studies dealing with automated hematology analyzers (HAs) and malaria diagnosis are conducted in endemic countries. We retrospectively studied cell blood counts (CBCs) performed with Sysmex XE-2100 and XE-5000 HAs in our center (Angers, France) regarding 67 patients returning from endemic areas and infected with various Plasmodium species. In 83% of infected samples with Plasmodium vivax (Pv), ovale (Po), or malariae (Pm), extra clouds of dots were present in neutrophil and/or eosinophil area(s) on routine differential (DIFF) scattergrams. In contrast, samples infected with Plasmodium falciparum (Pf) failed to show such DIFF scattergrams, or any other suggesting malaria infection (0/ 49 pts). Abnormal areas from DIFF scattergrams were related to the presence of mature schizonts and gametocytes, undestroyed by lysis agent, the latter not observed in Pf-infected patients from our series. The internal parameter WBC[DIFF] - WBC[BASO] raised in parallel to parasitemia in Pv, Po, and Pm samples but could not be used as a surrogate for parasitemia. In Pf infection, reticulocyte/ immature reticulocyte fraction (IRF) ratio showed a significant correlation with parasitemia (P < 0.05). A diagnostic model developed for Pf in endemic countries showed sensitivity of 77%. Using SYSMEX analyzers, Pv, Po, and Pm infections are easy to ascertain as DIFF scattergrams are almost specific (specificity = 99.9%). Pf infection diagnosis by CBC may be a more promising tool. © 2013 John Wiley & Sons Ltd.

  10. Establishment of Age- and Gender-Specific Reference Ranges for 36 Routine and 57 Cell Population Data Items in a New Automated Blood Cell Analyzer, Sysmex XN-2000.

    PubMed

    Park, Sang Hyuk; Park, Chan Jeoung; Lee, Bo Ra; Kim, Mi Jeong; Han, Min Young; Cho, Young Uk; Jang, Seongsoo

    2016-05-01

    We established age- and gender-specific reference ranges for the 36 routine complete blood cell (CBC) and 57 cell population data (CPD) items in the Sysmex XN-2000 (Sysmex, Japan). In total, 280 peripheral blood samples were obtained from an equal number of healthy adults. Values for 36 routine items and 57 CPD items were obtained for each sample, and the results were categorized into six subgroups (N>39 in each subgroup) according to patient age (20-40, 41-60, and >60 yr) and gender (male and female), and compared with respect to age and gender differences. The majority of data items (22 of 36 routine CBC items and 44 of 57 CPD items) exhibited significant differences (P≤0.05) in their results with respect to age or gender, and several red cell-, lymphocyte-, and platelet-related data tended to decrease in women or older adults. These results provide a basis for establishing age- and gender-specific reference ranges for routine and CPD items in Sysmex XN-2000. Furthermore, these reference ranges could be used to determine clinical significance for new items of Sysmex XN-2000 in further studies.

  11. Establishment of Age- and Gender-Specific Reference Ranges for 36 Routine and 57 Cell Population Data Items in a New Automated Blood Cell Analyzer, Sysmex XN-2000

    PubMed Central

    Park, Sang Hyuk; Lee, Bo-Ra; Kim, Mi-Jeong; Han, Min-Young; Cho, Young-Uk; Jang, Seongsoo

    2016-01-01

    We established age- and gender-specific reference ranges for the 36 routine complete blood cell (CBC) and 57 cell population data (CPD) items in the Sysmex XN-2000 (Sysmex, Japan). In total, 280 peripheral blood samples were obtained from an equal number of healthy adults. Values for 36 routine items and 57 CPD items were obtained for each sample, and the results were categorized into six subgroups (N>39 in each subgroup) according to patient age (20-40, 41-60, and >60 yr) and gender (male and female), and compared with respect to age and gender differences. The majority of data items (22 of 36 routine CBC items and 44 of 57 CPD items) exhibited significant differences (P≤0.05) in their results with respect to age or gender, and several red cell-, lymphocyte-, and platelet-related data tended to decrease in women or older adults. These results provide a basis for establishing age- and gender-specific reference ranges for routine and CPD items in Sysmex XN-2000. Furthermore, these reference ranges could be used to determine clinical significance for new items of Sysmex XN-2000 in further studies. PMID:26915613

  12. Optimization of laboratory workflow in clinical hematology laboratory with reduced manual slide review: comparison between Sysmex XE-2100 and ABX Pentra DX120.

    PubMed

    Hur, M; Cho, J-H; Kim, H; Hong, M-H; Moon, H-W; Yun, Y-M; Kim, J Q

    2011-08-01

    The validation of automated hematology analyzer results by manual slide review (MSR) is currently an inevitable work process in clinical hematology laboratories. The laboratory workload would be optimized if the requirement for MSR could be reduced without compromising patient care. We investigated whether slide-making rates would be different between two hematology analyzers, which were paired with their own automated slide makers/stainers: Sysmex XE-2100 with SP-1000i (Sysmex, Kobe, Japan) and ABX Pentra DX120 with SPS evolution (ABX-Horiba, Montpellier, France). A total of 943 samples were run in parallel on the Sysmex XE-2100 and ABX Pentra DX120. Reflex slides were automatically made in each analyzer according to its own criteria, which reflected the criteria of MSR in our laboratory. The slide-making rates were compared, and the results were further confirmed using the criteria of MSR. The slide-making rates in Sysmex XE-2100, ABX Pentra DX120, and manual review were 22.5% (212/943), 15.91% (150/943), and 11.5% (108/943), respectively. In 774 (82.1%) samples, the three methods showed concordant results, and all made slides in 82 samples. Using the manual method as a standard, the sensitivity and specificity were 86.1% and 85.8% in Sysmex XE-2100 and 89.8% and 93.7% in ABX Pentra DX120. Our data show that the slide-making rates are variable in different hematology analyzers. It also implies that although MSR cannot be fully substituted by modern hematology analyzers, it can be effectively reduced to optimize laboratory workload. © 2011 Blackwell Publishing Ltd.

  13. [Influence of reagent storage in Sysmex CA7000 for different time on 4 test RESULTS: of the plasma coagulation].

    PubMed

    Chen, Tong-Qing; Li, Zhen-Xing

    2014-12-01

    The purpose of this study was to investigate the influence of blood coagulation reagents stored for different time on test results of the specimens prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time (TT) and fibrinogen (Fib). A total of 21 patient plasma specimens was taken and measured for homeostasis by Sysmex CA7000 automated blood coagulation analyzer and supporting reagent. The PT, APTT, TT and Fib of specimens were measured with the reagents stored in Sysmex CA7000 for different time. The differences of PT, APTT, TT and Fib were analyzed between values measured of the reagents stored for 0 hour and different time (TS:12, 24, 36,48, 60, 72 h; DA:24, 48, 72, 96, 120 h; TT:2, 4, 6, 8, 10, 12 h; TR:4, 8, 12, 16, 20, 24 h; OVB:1, 2, 3, 4, 5 ,6 h), respectively. The results showed that when coagulation reagent TS were stored for more than 48 h , DA 96 h, TT 10 h, TR 16 h and OVB 4 h, the values of PT, APTT, TT and Fib of samples were statistically different from the values measured with fresh coagulation reagent (P < 0.01), respectively. Compared 0 h with TS stored for 48-72, DA 96-120, TT 10-12, TR 16-24 and OVB 4-6 h, the percentage difference of PT, APTT, TT and Fib is in -2.6% ∼ 10.8%, -3.44% ∼ 4.8%, -3.9% ∼ 5.52%, -10.8% ∼ 3.3% and -17.2% ∼ 0.5%, the PT and Fib changes were more significant. Accordingly, the result of PT, APTT and TT had a uptrend as the reagent stored in Sysmex CA7000 analyzer for a long time, while Fib downtrend. It is concluded that the reagents showed be timely replaced when the plasma coagulation test is performed so as to obtain accurate results of examination.

  14. The value of the white precursor cell channel (WPC) on the Sysmex XN-1000 analyser in a specialist paediatric hospital.

    PubMed

    Jones, Amanda S; Tailor, Hitesh; Liesner, Ri; Machin, Samuel J; Briggs, Carol J

    2015-02-01

    Historically, haematology analyser flags for abnormal white blood cells (WBCs) show good sensitivity but lower specificity, causing unnecessary blood film reviews. While the WBC differential channel on Sysmex XE and XN instruments reports a combined flag for blasts/abnormal lymphocytes, the new white precursor cell channel (WPC) on the XN series has been introduced to separate this into a specific flag for either cell type or, if no abnormality, remove the flag entirely. To compare the efficiency of abnormal WBC flags from the XN WPC to our existing analyser and determine whether WPC can reduce false positive flags and blood films required. Abnormal WBC flags from the Sysmex XE-5000 and XN-1000 were compared to manual differential and blood film morphology on 300 K2EDTA samples from infants and children. The XN WPC flag for blasts was more sensitive and specific than flags indicating blasts on the XE-5000, with a reduction in false positives from 64% (XE) to 36% (XN). Overall efficiency of the WPC flag for abnormal lymphocytes was 94% vs 79% on the XE. WPC reduced false positive flags for blasts and abnormal lymphocytes on neonatal samples by 50%. Automatic reflex analysis by WPC correctly removed a false positive flag from the white cell differential channel on 46% of samples. Total abnormal WBC flags from XN WPC were less (73) than the XE-5000 (92). XN WPC demonstrated superior efficiency of abnormal WBC flags on paediatric samples, compared to the XE-5000, with greater sensitivity and specificity of flagging, reducing blood films for review. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  15. Diagnosing feline infectious peritonitis using the Sysmex XT-2000iV based on frozen supernatants from cavitary effusions.

    PubMed

    Stranieri, Angelica; Paltrinieri, Saverio; Giordano, Alessia

    2017-02-01

    The delta total nucleated cells (ΔTNC) measurement with the Sysmex XT-2000iV (Sysmex Europe, Norderstedt, Germany) has high diagnostic accuracy on effusions in feline infectious peritonitis (FIP) cases, but the test can be performed only on fresh samples. We evaluated whether supernatants from effusions retain the ability to induce cell clumping and assessed the diagnostic accuracy of this modified ΔTNC method. Effusions were collected from FIP cats ( n = 19) and from cats with other diseases ( n = 15). ΔTNC was measured on fresh samples and on frozen-thawed supernatants after the addition of feline blood at 1:10 dilution. Diagnostic accuracy was assessed at the cutoffs of suggestive of FIP (ΔTNC = 1.7) and consistent with FIP (ΔTNC = 3.4). The influence of the protein content, number of added cells, and magnitude of dilution were also investigated. Specificity and positive predictive value were 100% for both the methods. Sensitivity and negative predictive value were higher for the modified ΔTNC (84.2% and 83.3%, respectively, at the cutoff of 1.7; 78.9% and 78.9%, respectively, at the cutoff of 3.4) than for the ΔTNC on fresh samples (78.6% and 81.3%, respectively, at the cutoff of 1.7; 57.1% and 68.4%, respectively, at the cutoff of 3.4). Protein content, total cell count of the added blood, and magnitude of dilutions did not influence the results. Supernatants of frozen effusions from FIP cats retain the ability to induce cell clumping, thus the modified ΔTNC measurement is a reliable tool to diagnose FIP on samples that cannot be analyzed immediately.

  16. Optimized gating and reference ranges of reticulated platelets in dogs for the Sysmex XT-2000iV.

    PubMed

    Oellers, Dana E; Bauer, Natali; Ginder, Melanie; Johannes, Sigrid; Pernecker, Iris; Moritz, Andreas

    2016-07-22

    Canine reticulated platelets (r-PLTs) i.e., juvenile PLTs reflecting thrombopoiesis can be measured automatically with the hematology analyzer Sysmex XT-2000iV using manual gating options. However, the impact of interferences on r-PLT measurements performed with the gates published previously (Pankraz et al., Vet Clin Path 38:30-38, 2009; Gelain et al., High fluorescent platelets fraction in macrothrombocytopenic Norfolk terrier, 2010) is largely unknown. The aim was to compare different published gates for measurement of r-PLTs with the Sysmex XT-2000iV with an own, optimized gate ("Oellers-gate") and to establish reference intervals (RIs) in > 120 dogs. Data of 362 measurements of diseased and healthy dogs were analyzed retrospectively. Several gates were applied and RIs for r-PLTs and platelet indices were established for pet dogs and a group of 153 healthy Beagles kept under defined housing conditions. Intra-assay precision (CV) was also assessed. In 30/362 samples, interferences consistent with small erythrocytes/reticulocytes were seen in the previously published gates but not in the "Oellers-gate". Good correlation was found between the different gates (rs: 0.88-1.00). RIs for the "Pankraz-gate", the "Gelain-gate", and the "Oellers-gate" were 0.0-1.2, 0.2-3.7 and 0.2-3.9 % respectively. CVs were ranging between 22 and 41 %. Optimization of previously published gates minimized interferences of small erythrocytes with r-PLT measurements.

  17. Measurement of immature platelets with Abbott CD-Sapphire and Sysmex XE-5000 in haematology and oncology patients.

    PubMed

    Meintker, Lisa; Haimerl, Maria; Ringwald, Jürgen; Krause, Stefan W

    2013-11-01

    Measurement of immature platelets was introduced into routine diagnostics by Sysmex as immature platelet fraction (IPF) some years ago and recently by Abbott as reticulated platelet fraction (rPT). Here, we compare both methods. We evaluated the precision and agreement of these parameters between Sysmex XE-5000 and Abbott CD-Sapphire in three distinct thrombocytopaenic cohorts: 30 patients with beginning thrombocytopaenia and 64 patients with recovering platelets (PLT) after chemotherapy, 16 patients with immune thrombocytopaenia (ITP) or heparin-induced thrombocytopaenia type 2 (HIT) and 110 additional normal controls. Furthermore, we analysed, how IPF/rPT differed between these thrombocytopaenic cohorts and controls. Both analysers demonstrated acceptable overall precision (repeatability) of IPF/rPT with lower precision at low PLT counts. IPF/rPT artificially increased during storage of blood samples overnight. Inter-instrument comparison showed a moderate correlation (Pearson r²=0.38) and a systematic bias of 1.04 towards higher IPF-values with the XE-5000. IPF/rPT was highest in recovering thrombopoesis after chemotherapy and moderately increased in ITP/HIT. The normal range deduced from control samples was much narrower with CD-Sapphire (1.0%-3.8%, established here for the first time) in comparison to XE-5000 (0.8%-7.9%) leading to a smaller overlap of samples with increased PLT turnover and normal controls. IPF and rPT both give useful information on PLT turnover, although the two analysers only show a moderate inter-instrument correlation and have different reference ranges. A better separation of patient groups with high PLT turnover like ITP/HIT from normal controls is obtained by CD-Sapphire.

  18. Limits of preservation of samples for urine strip tests and particle counting.

    PubMed

    Kouri, Timo; Malminiemi, Outi; Penders, Joris; Pelkonen, Virpi; Vuotari, Lotta; Delanghe, Joris

    2008-01-01

    Preservation of urine samples is important for centralised laboratory services with automated instruments. A multicentre evaluation was carried out to assess preservative tubes from BD Diagnostics-Preanalytical Systems and from Greiner Bio-One for test strip reading (documented at the level of remission values), for particle counting by flow cytometers (UF-100) and for visual microscopy. Failures were expressed as percentages of originally positive samples beyond a two-fold change (+100% or -50%) from the original values. The preservative-containing BD Plus C&S plastic, BD Plus UAP and Greiner Stabilur tubes succeeded in preservation of test strip results for 6-24 h (exceptions were glucose and nitrite tests). Greiner boric acid tube showed false negative results in leukocyte, protein and ketone strip tests immediately after adding the preservative. Urine red blood cell counts (with Sysmex UF-100) were preserved for 5 h in BD Plus C&S plastic and Greiner Stabilur tubes (Greiner tubes having clearly larger preservative-related background). Bacteria or white blood cell counting succeeded in BD Plus C&S plastic tubes for 5 or 24 h, respectively, but up to 72 h in Greiner Stabilur tubes. In visual microscopy, the Greiner Stabilur tube was slightly better than the BD Plus C&S plastic tube. Urine specimens can be transported at +20 degrees C on the day of collection if preserved properly. Longer delays need careful planning with current preservatives. Flow cytometry with UF-100 is sensitive to non-dissolved preservative remnants.

  19. A Comparison of Mindray BC-6800, Sysmex XN-2000, and Beckman Coulter LH750 Automated Hematology Analyzers: A Pediatric Study.

    PubMed

    Ciepiela, Olga; Kotuła, Iwona; Kierat, Szymon; Sieczkowska, Sandra; Podsiadłowska, Anna; Jenczelewska, Anna; Księżarczyk, Karolina; Demkow, Urszula

    2016-11-01

    Modern automated laboratory hematology analyzers allow the measurement of over 30 different hematological parameters useful in the diagnostic and clinical interpretation of patient symptoms. They use different methods to measure the same parameters. Thus, a comparison of complete blood count made by Mindray BC-6800, Sysmex XN-2000 and Beckman Coulter LH750 was performed. A comparison of results obtained by automated analysis of 807 anticoagulated blood samples from children and 125 manual microscopic differentiations were performed. This comparative study included white blood cell count, red blood cell count, and erythrocyte indices, as well as platelet count. The present study showed a poor level of agreement between white blood cell enumeration and differentiation of the three automated hematology analyzers under comparison. A very good agreement was found when comparing manual blood smear and automated granulocytes, monocytes, and lymphocytes differentiation. Red blood cell evaluation showed better agreement than white blood cells between the studied analyzers. To conclude, studied instruments did not ensure satisfactory interchangeability and did not facilitate a substitution of one analyzer by another. © 2016 Wiley Periodicals, Inc.

  20. Clinical significance of cell population data (CPD) on Sysmex XN-9000 in septic patients with our without liver impairment

    PubMed Central

    Seghezzi, Michela; Vavassori, Mauro; Dominoni, Paola; Apassiti Esposito, Sara; Manenti, Barbara; Mecca, Tommaso; Marchesi, Gianmariano; Castellucci, Enrico; Azzarà, Giovanna; Ottomano, Cosimo; Lippi, Giuseppe

    2016-01-01

    Background This study evaluated the clinical significance of cell population data (CPD) parameters obtained on Sysmex XN-9000 in septic patients admitted to intensive care unit (ICU) and stratified according to liver function. Methods The study population consisted in 84 patients, 44 of whom did not develop sepsis (NS), whereas the remaining 40 developed sepsis (SE) (n=24) or septic shock (SS) (n=16). Two hundred ostensibly healthy blood donors [healthy subjects (HS)], undergoing routine blood testing before a regular blood donation, were studied. Results Except for neutrophils and lymphocytes cell size (NE-FCS and LY-Z), all other CPD values were significantly different in ICU patients compared to HS. Neutrophils and monocytes fluorescence intensity (NE-SFL and MO-X) values were significantly higher in SS compared to sepsis and not develop sepsis patients. The value of many parameters was also different according to liver function. Overall, MO-X and neutrophils fluorescence intensity (NE-SFL) exhibited the best performance for diagnosing sepsis in all patients (AUC, 0.75 and 0.72), as well as in those with (AUC, 0.95 and 0.89) or without (AUC, 0.72 for both) liver impairment. These parameters were also significantly correlated with Sequential Organ Failure Assessment (SOFA) score. Conclusions This study suggested that some novel CPD parameters (namely NE-SFL and MO-X) may provide useful information for diagnosis and management of sepsis. PMID:27942509

  1. Comparison of five automated hematology analyzers in a university hospital setting: Abbott Cell-Dyn Sapphire, Beckman Coulter DxH 800, Siemens Advia 2120i, Sysmex XE-5000, and Sysmex XN-2000.

    PubMed

    Bruegel, Mathias; Nagel, Dorothea; Funk, Manuela; Fuhrmann, Petra; Zander, Johannes; Teupser, Daniel

    2015-06-01

    Various types of automated hematology analyzers are used in clinical laboratories. Here, we performed a side-by-side comparison of five current top of the range routine hematology analyzers in the setting of a university hospital central laboratory. Complete blood counts (CBC), differentials, reticulocyte and nucleated red blood cell (NRBC) counts of 349 patient samples, randomly taken out of routine diagnostics, were analyzed with Cell-Dyn Sapphire (Abbott), DxH 800 (Beckman Coulter), Advia 2120i (Siemens), XE-5000 and XN-2000 (Sysmex). Inter-instrument comparison of CBCs including reticulocyte and NRBC counts and investigation of flagging quality in relation to microscopy were performed with the complete set of samples. Inter-instrument comparison of five-part differential was performed using samples without atypical cells in blood smear (n=292). Automated five-part differentials and NRBCs were additionally compared with microscopy. The five analyzers showed a good concordance for basic blood count parameters. Correlations between instruments were less well for reticulocyte counts, NRBCs, and differentials. The poorest concordance for NRBCs with microscopy was observed for Advia 2120i (Kendall's τb=0.37). The highest flagging sensitivity for blasts was observed for XN-2000 (97% compared to 65%-76% for other analyzers), whereas overall specificity was comparable between different instruments. To the best of our knowledge, this is the most comprehensive side-by-side comparison of five current top of the range routine hematology analyzers. Variable analyzer quality and parameter specific limitations must be considered in defining laboratory algorithms in clinical practice.

  2. Canine differential leukocyte counting with the CellaVision DM96Vision, Sysmex XT-2000iV, and Advia 2120 hematology analyzers and a manual method.

    PubMed

    Tvedten, Harold W; Lilliehöök, Inger E

    2011-09-01

    For differential leukocyte counts, automated blood smear evaluation systems have been too slow or inaccurate to replace or supplement the manual differential count. The CellaVision DM96Vision (DM96V), a new instrument, is an automated image analysis system that is rapid and accurate enough to be used for enumerating human leukocytes and may be useful for analysis of canine blood. The aims of this study were to evaluate the performance of the DM96V in differential counting of canine leukocytes, to compare its performance with that of other methods, and to analyze interoperator variability. Four methods of determining the leukocyte differential count of 108 canine blood samples were compared based on agreement, precision, and errors as well as relative performance. Differential counts were obtained using the DM96V, the manual method, and automated methods performed by the Advia 2120 and Sysmex XT-2000iV. All leukocyte types were detected by the DM96V and the manual method, and all 4 methods had similar mean and median results in most cases. The automated methods were more precise than either the DM96V or manual method when comparing identification of a single type of leukocyte, especially neutrophils and lymphocytes. However, precision of the automated methods was only fair for monocytes, and the Advia and Sysmex failed to identify basophils. The Advia reported fewer monocytes and eosinophils than did the other methods. Significantly fewer lymphocytes were identified by the manual method than by the Sysmex, Advia, and DM96V. The DM96V occasionally presented duplicate images of the same neutrophils. The CellaVision DM96V is a satisfactory system for facilitating canine differential leukocyte counting. The DM96V differential count was more similar to the manual count than to automated counts, which were more precise but had errors and omissions in detecting some types of leukocytes. ©2011 American Society for Veterinary Clinical Pathology.

  3. Cell Population Data and reflex testing rules of cell analysis in pleural and ascitic fluids using body fluid mode on Sysmex XN-9000.

    PubMed

    Buoro, Sabrina; Mecca, Tommaso; Azzarà, Giovanna; Seghezzi, Michela; Dominoni, Paola; Crippa, Alberto; Ottomano, Cosimo; Lippi, Giuseppe

    2016-01-15

    Although optical microscopy (OM) remains the reference technique for analysis of ascitic (AF) and pleural (PF) fluids, novel hematological analyzers are equipped with modules for body fluid (BF) analysis. This study was aimed to analyze the performance of XN-BF module in Sysmex XN-9000, and to develop validation rules for automated cell counts in BFs. The evaluation of XN-BF module included assessment of carryover, Limit of Blank (LoB), Limit of Detection (LoD), Limit of Quantitation (LoQ), linearity, data comparison with OM, and development of rules for assisting the validation of automated analysis of BFs and activating reflex testing. The carryover was negligible. The LoB, LoD, LoQ and linearity were always excellent. The comparison with OM was characterized by Pearson's correlations ranging from r=0.50 to r=0.99 (p<0.001), modest bias and high diagnostic concordance (Area Under the Curve between 0.85 and 0.99). The use of instrument-specific cut-offs further increased diagnostic concordance. The implementation of reflex testing rules based on XN-BF data increased sensitivity and specificity of BFs classification to 0.98 and 0.95. Our results suggest that the XN-BF module on Sysmex-9000 may be a suitable alternative to OM for screening BF samples, especially when specific validation rules are used. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Improved flagging rates on the Sysmex XE-5000 compared with the XE-2100 reduce the number of manual film reviews and increase laboratory productivity.

    PubMed

    Briggs, Carol J; Linssen, Joachim; Longair, Ian; Machin, Samuel J

    2011-08-01

    Hematology analyzers generate suspect flags in the presence of abnormal cells. False-positive rates for flags are high on all analyzers. Sysmex, Kobe, Japan, has developed new software for its XE-5000 with improved algorithms for flagging blast cells, abnormal lymphocytes or lymphoblasts, and atypical lymphocytes. This study evaluated the efficiency of these flags in 1,002 samples. The XE-5000 was compared with the XE-2100 (Sysmex) and microscopic examination of cell morphologic features. On the XE-2100, the blast flag demonstrated 90 false-positives, 13 true-positives, and 3 false-negatives. The values on the XE-5000 were 27 false-positives, 14 true-positives, and 2 false-negatives. The abnormal lymphocyte/lymphoblast flag was assessed with the atypical lymphocyte flag. The XE-2100 showed 114 false-positives, 23 true-positives, and 20 false-negatives, and on the XE-5000, there were 45 false-positives, 22 true-positives, and 21 false-negatives. This more specific flagging reduces the number of films that require manual review.

  5. Identification of neoplastic cells in blood using the Sysmex XT-2000iV: a preliminary step in the diagnosis of canine leukemia.

    PubMed

    Gelain, Maria Elena; Rossi, Gabriele; Giori, Luca; Comazzi, Stefano; Paltrinieri, Saverio

    2010-06-01

    Classification of leukemias requires specialized diagnostic techniques. Automated preliminary indicators of neoplastic cells in blood would expedite selection of appropriate tests. The objective of this study was to assess the capacity of the Sysmex XT-2000iV hematology analyzer to identify neoplastic cells in canine blood samples. Blood samples (n=160) were grouped into 5 categories: acute leukemia (n=30), chronic leukemia (n=15), neoplasia without blood involvement (n=41), non-neoplastic reactive conditions (n=31), and healthy dogs (n=43). WBC counts, WBC flags, scattergrams, percentages of cells with high fluorescence intensity, and percentages of cells in the lysis-resistant region were evaluated alone or in combination to establish a "leukemic flag." Sensitivity, specificity, negative (LR-) and positive (LR+) likelihood ratios, and the number of false-negative (FN) and false-positive (FP) results were calculated, and receiver operating characteristic curves were designed for numerical values. Among single measurements and parameters, only the evaluation of scattergrams minimized FN and FP results (sensitivity 100%, specificity 94.8%, LR+ 19.17, and LR- 0.00), although their interpretation was subjective. The more objective approach based on the generation of a "leukemic flag" had a sensitivity of 100%, specificity of 87.0%, LR- of 0.00, and LR+ of 7.67. Using a novel gating strategy the Sysmex XT-2000iV may be used effectively to screen canine blood for hematopoietic neoplasia.

  6. Detection of malignant cells in serous body fluids by counting high-fluorescent cells on the Sysmex XN-2000 hematology analyzer.

    PubMed

    Labaere, D; Boeckx, N; Geerts, I; Moens, M; Van den Driessche, M

    2015-10-01

    The body fluid mode of the Sysmex XN-2000 hematology analyzer differentiates cells into mononuclear and polymorphonuclear white blood cells (WBC) and high-fluorescent cells (HFC). The aim of this study was to evaluate the performance of the HFC count for detecting malignant cells in serous body fluids. Two-hundred and thirty serous fluids were analyzed on the Sysmex XN body fluid mode. HFC were measured as relative count (HFC/100 WBC) and absolute count (HFC/μL). All samples were microscopically screened on cytospin slides for the presence of malignant cells. Malignant cells were found by microscopic examination in 49 of 230 samples (21.3%). Malignant samples contained significantly higher percentages (10.2 vs. 2.6/100 WBC) and absolute numbers (65 vs. 10/μL) of HFC than nonmalignant samples (P < 0.001). Areas under the ROC curve for relative and absolute HFC count were 0.69 and 0.77, respectively. A cutoff level of ≥17 HFC/μL showed the best performance to predict malignancy, with 88% sensitivity and 61% specificity. As serous body fluids will be more analyzed on automated analyzers in the future, HFC count can be a useful tool to select samples for microscopic review. Microscopic evaluation should be performed if HFC values are above a certain threshold (e.g. ≥17 HFC/μL) or in case of clinical suspicion of malignancy. © 2015 John Wiley & Sons Ltd.

  7. Feline reference intervals for the Sysmex XT-2000iV and the ProCyte DX haematology analysers in EDTA and CTAD blood specimens.

    PubMed

    Granat, Fanny; Geffré, Anne; Bourgès-Abella, Nathalie; Mortier, Jeremy; Théron, Marie-Laure; Fauchon, Emilie; Braun, Jean-Pierre; Trumel, Catherine

    2014-06-01

    Laser-based haematology analysers are routinely used in veterinary clinical pathology laboratories, and are available to practitioners. However, feline haematological reference intervals (RIs) determined according to international recommendations are, to our knowledge, not available. Furthermore, platelet count RI is difficult to establish in cats because of the frequent occurrence of platelet aggregation in blood specimens. The purpose of this study was to establish feline haematological RIs with the Sysmex XT-2000iV and ProCyte DX analysers, in ethylenediamine tetra-acetic acid (EDTA) and in citrate, theophylline, adenosine and dipyridamole (CTAD), which is a combination of anticoagulants limiting platelet aggregation. Blood specimens from 120 healthy cats were analysed in duplicate, and the degree of platelet aggregation was assessed on blood smears. After exclusion of inadequate specimens, 81 sets of results (from 44 males and 37 females, aged from 6 to 116 months) were available for the determination of RIs by the non-parametric method. The effects of the anticoagulant, analyser and aggregation score were assessed. When the aggregation effect was significant, the RIs were determined using the subgroup of blood specimens with no or little aggregation. The effects of sex, age and weight were also investigated, but were moderate. The different RIs obtained with the Sysmex XT-2000iV and ProCyte DX analysers, and the two anticoagulants, were very similar to previous RIs established in EDTA with the ADVIA 120, another laser-based analyser, except for the platelet count in CTAD specimens. Its lower reference limit was higher in CTAD vs EDTA specimens, which confirms the interest in this anticoagulant in cats.

  8. [Laboratory evaluation of the Sysmex NE-7000 flagging system; a tool for the recognition of abnormal cells in white cell differentials].

    PubMed

    Kondo, S; Yamaguchi, N; Imanishi, T; Sakota, H; Jokei, Y; Mituda, A

    1991-06-01

    Sysmex NE-7000 flagging system was evaluated for the recognition of abnormal cells in white cell differentials. Six flags that could mark blasts, immature granulocytes, left shift, nucleated red blood cells, atypical lymphocytes, and platelet clumps were selected for evaluation. 182 morphologic abnormal samples were screened from the Kobe University Hospital patients, by means of the 600 eye counts differentials. Blasts flag missed 8 of 28 cases, and immature granulocytes flag missed 25 of 56 cases. These missed cases contained either relatively few abnormal cells; less than 3% immature granulocytes, or absolutely few cells; less than 201 per micro liter blasts. Platelet clumps flag missed only 2 of 23 cases. But nucleated red blood cells and atypical lymphocytes flags missed all of 7 and 4 cases respectively. Left shift flag missed 36 of 64 cases, but it could help marking immature granulocytes or blasts. To use the NE-7000 as a screening tool, we compared the NE's all 35 flags versus abnormal cells or status based on the 100 eye counts. 1,153 cases were analyzed. Full agreement; 1047 (90.8%), partial agreement; 61 (5.2%), distributional false normal; 7 (1.6%), and morphological false normal; 4 (4.6%), were obtained. The more flags were used, the less abnormal cases were missed. But it accompanied the increase of the flag positive cases that must be confirmed by eye.

  9. Comparison of four hematology analyzers, CELL-DYN Sapphire, ADVIA 120, Coulter LH 750, and Sysmex XE-2100, in terms of clinical usefulness.

    PubMed

    Kang, S H; Kim, H K; Ham, C K; Lee, D S; Cho, H I

    2008-12-01

    We evaluated the clinical usefulness (leukocyte distribution classification, morphologic classification, and morphologic flags) of the following four hematology analyzers: CELL-DYN Sapphire (CD-Sapphire) (Abbott Diagnostics, Santa Clara, CA, USA), ADVIA 120 (Bayer Diagnostics, Tarrytown, NY, USA), Beckman Coulter LH 750 (Beckman Coulter, Miami, FL, USA), and Sysmex XE-2100 (TOA Medical Electronics Co., Kobe, Japan). Four hundred thirty samples from patients and 100 samples from healthy individuals were analyzed. For distributional classification, the sensitivity rates of CD-Sapphire, ADVIA 120, LH 750, and XE-2100 were 93.1, 95.9, 94.9, and 94.9%, respectively, and the efficiency rates were 80.7, 81.6, 84.1, and 84.2%, respectively. For morphologic classification, the sensitivity rates of CD-Sapphire, ADVIA 120, LH 750, and XE-2100 were 88.6, 93.2, 77.3, and 94.3%, respectively, and the efficiency rates were 80.9, 73.0, 79.5, and 74.2%, respectively. Comparing the findings in different morphologic flags, XE-2100 showed the highest sensitivity for Blasts flag (90.9%); CD-Sapphire showed the highest sensitivity for Immature granulocytes and/or Left-shift flag (85.5%); ADVIA 120 showed the highest sensitivity for Atypical lymphocytes flag (60.0%); and LH 750 showed the highest sensitivity for Nucleated RBC flag (75.0%). Our results demonstrate that the four analyzers are comparable in overall performance.

  10. Validation of the Sysmex CS5100 coagulation analyzer and comparison to the Stago STA-R analyzer for routine coagulation parameters.

    PubMed

    Geens, T; Vertessen, F; Malfait, R; Deiteren, K; Maes, M B

    2015-06-01

    The CS5100 analyzer (Sysmex) was validated for the determination of routine coagulation parameters. This fully automated coagulation analyzer uses multiple wavelength technology to perform coagulation (e.g., activated partial thromboplastin time - APTT, prothrombin time - PT, fibrinogen - FBG), chromogenic (e.g., antithrombin - AT) and immunological (e.g., D-dimers - DDi) assays. A comparison with the currently used STA-R Evolution (Stago) was performed. Validation and verification of reference values of the CS5100 was performed in accordance to CLSI guidelines (H57-A, H47-A2, and C28-A3). As a different detection system and reagents were used, significant differences were observed (e.g. APTT). The within-day and between-day imprecision, accuracy and total error were all acceptable. The reference values defined by the manufacturer could be used except for APTT. In our settings, the therapeutic anti-Xa range of 0.3-0.7 IU/mL corresponded to an APTT range of 60-100 s (Dade actin FS reagent). The APTT reagent showed factor sensitivities between 46 and 72% for FVIII, IX, XI and XII while the PT reagent showed sensitivities between 34 and 52% for FII, FV, FXII, and FX. In conclusion, the CS5100 instrument is suitable for the determination of the APTT, PT, FBG, DDi and AT in routine analysis. © 2014 John Wiley & Sons Ltd.

  11. Evaluation of the automated hematology analyzer Sysmex XT-2000iV™ compared to the ADVIA® 2120 for its use in dogs, cats, and horses: Part I--precision, linearity, and accuracy of complete blood cell count.

    PubMed

    Bauer, Natali; Nakagawa, Julia; Dunker, Cathrin; Failing, Klaus; Moritz, Andreas

    2011-11-01

    The automated laser-based hematology analyzer Sysmex XT-2000iV™ providing a complete blood cell count (CBC) and 5-part differential has been introduced in large veterinary laboratories. The aim of the current study was to determine precision, linearity, and accuracy of the Sysmex analyzer. Reference method for the accuracy study was the laser-based hematology analyzer ADVIA® 2120. For evaluation of accuracy, consecutive fresh blood samples from healthy and diseased cats (n = 216), dogs (n = 314), and horses (n = 174) were included. A low intra-assay coefficient of variation (CV) of approximately 1% was seen for the CBC except platelet count (PLT). An intra-assay CV ranging between 2% and 5.5% was evident for the differential count except for feline and equine monocytes (7.7%) and horse eosinophils (15.7%). Linearity was excellent for white blood cell count (WBC), hematocrit value, red blood cell count (RBC), and PLT. For all evaluated species, agreement was excellent for WBC and RBC, with Spearman rank correlation coefficients (r(s)) ranging from >0.99 to 0.98. Hematocrit value correlated excellently in cats and dogs, whereas for horses, a good correlation was evident. A good correlation between both analyzers was seen in feline and equine PLT (r(s) = 0.89 and 0.92, respectively), whereas correlation was excellent for dogs (r(s) = 0.93). Biases were close to 0 except for mean corpuscular hemoglobin concentration (4.11 to -7.25 mmol/l) and canine PLT (57 × 10(9)/l). Overall, the performance of the Sysmex analyzer was excellent and compared favorably with the ADVIA analyzer.

  12. The use of CellaVision™ DM96 in the verification of the presence of blasts in samples flagged by the Sysmex XE-5000.

    PubMed

    Eilertsen, H; Henriksson, C E; Hagve, T-A

    2017-08-01

    The CellaVision™DM96 is a digital pattern recognition system that classifies white blood cells. The aim of this study was to evaluate whether the CellaVision preclassification feature, without a subsequent re-classification, was a sufficient approach to follow up flags reported by Sysmex XE-5000. Pairs of blood smears from 400 samples reported with suspect flags were examined using conventional microscopy and the CellaVision features. The effect of pre- vs. re-classification, and intersmear and between-technologist variation, on blast counts was assessed using generalized linear mixed models (GLMM). The GLMM analysis showed a significant difference between the blast counts of preclassification vs. re-classification (P = 0.009). The analysis showed no significant difference between duplicate smears (P = 0.621) or between technologists (P = 0.542). Preclassification showed blasts in 105 samples (26%), where the re-classification feature did not detect any blasts. Not a single sample that was re-classified as positive for blasts was preclassified as negative. Compared to manual microscopy, the sensitivity and specificity of the preclassification feature were 0.83 and 0.66, respectively. The preclassification feature alone is sufficient to verify the absence of blasts in flagged samples. When the preclassification feature detects blasts, the finding has to be verified or reclassified by an experienced technologist. However, the use of CellaVision™DM96 in the follow-up of blast reports has to be questioned due to the finding of false-negative samples in the preclassification feature, but also after re-classification, compared to manual slide review. © 2017 John Wiley & Sons Ltd.

  13. Changes in haematology measurements with the Sysmex XT-2000iV during storage of feline blood sampled in EDTA or EDTA plus CTAD.

    PubMed

    Granat, Fanny; Geffré, Anne; Bourgès-Abella, Nathalie; Braun, Jean-Pierre; Trumel, Catherine

    2013-06-01

    In veterinary medicine a complete blood cell count (CBC) cannot always be performed within 24 h as usually recommended, particularly for specimens shipped to a reference laboratory. This raises the question of the stability of the variables, especially in ethylenediamine tetra-acetic acid (EDTA) feline blood specimens, known to be prone to in vitro platelet aggregation. Citrate, theophylline, adenosine and dipyridamole (CTAD) has been reported to limit platelet aggregation in feline blood specimens. The aim of this study was to measure the stability of the haematological variables and the platelet aggregation score in EDTA and EDTA plus CTAD (EDCT) feline blood specimens during 48 h of storage at room temperature. Forty-six feline EDTA and EDCT blood specimens were analysed with a Sysmex XT-2000iV analyser, and the platelet count and score of platelet aggregation were estimated immediately and after 24 and 48 h of storage. A significant increase in mean corpuscular volume, haematocrit, reticulocyte and eosinophil counts, and a significant decrease in mean corpuscular haemoglobin concentration and monocyte count were observed. Haemoglobin, mean corpuscular haemoglobin, and red blood cell, white blood cell, neutrophil and lymphocyte counts remained stable. Changes in reticulocyte indexes with time (low fluorescence ratio, medium fluorescence ratio, high fluorescence ratio and immature reticulocyte fraction) were not significant. Changes were generally more pronounced in EDTA than in EDCT. Platelet aggregation decreased markedly in initially highly aggregated EDTA specimens, and increased slightly in initially non- or mildly-aggregated EDTA or EDCT specimens. Platelet counts increased and decreased, or remained stable, respectively. CTAD can reduce storage-induced changes of the haematological variables in feline samples, thus improving the reliability of a CBC and limiting clinical misinterpretations.

  14. Evaluation of Sysmex XN-1000 High-Sensitive Analysis (hsA) Research Mode for Counting and Differentiating Cells in Cerebrospinal Fluid.

    PubMed

    Fleming, Chérina; Russcher, Henk; Brouwer, Rob; Lindemans, Jan; de Jonge, Robert

    2016-03-01

    Counting cells in cerebrospinal fluid (CSF) using automated analyzers is generally problematic due to low precision at low cell numbers. To overcome this limitation, Sysmex (Kobe, Japan) developed the high-sensitive analysis (hsA) research mode specifically for counting cells in fluids that contain low cell counts. We evaluated this mode by counting RBCs, WBCs, and differentiated WBCs in CSF samples. We analyzed 248 CSF samples using the hsA mode and compared these results with those obtained using the manual counting method. We also evaluated the linearity, detection limits, carryover, and precision of the hsA mode. Using the hsA mode, the lower limit of quantification for RBCs and WBCs was 10 and 2 cells/μL, respectively. Comparing the two methods revealed good agreement with respect to WBCs (y = 1.08x + 0.52), RBCs (y = 1.07x + 0.00), lymphocytes (y = 1.00x + 0.00), neutrophils (y = 1.05x + 0.00), and monocytes (y = 0.88x + 0.07). Regression analysis for samples containing low WBCs (<10 cells/μL) and low RBCs (<50 cells/μL) also had good agreement, although a slight positive bias was found for RBCs. Linearity was good (r(2) ≥ 0.99) for all parameters evaluated. Carryover was negligible and never exceeded 0.04%. The XN hsA research mode provides reliable cell counts in CSF samples, even in samples containing low numbers of WBCs and RBCs. © American Society for Clinical Pathology, 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  15. Validation of the body fluid module on the new Sysmex XN-1000 for counting blood cells in cerebrospinal fluid and other body fluids.

    PubMed

    Fleming, Chérina; Brouwer, Rob; Lindemans, Jan; de Jonge, Robert

    2012-10-01

    We evaluated the body fluid (BF) module on the new Sysmex XN-1000 for counting blood cells. One hundred and eighty-seven BF samples [73 cerebrospinal fluid (CSF), 48 continuous ambulatory peritoneal dialysis (CAPD), 46 ascites, and 20 pleural fluid] were used for method comparison between the XN-1000 and manual microscopy (Fuchs-Rosenthal chamber and stained cytospin slides) for counting red blood cells (RBCs) and white blood cells (WBCs) (differential). Good agreement was found for counting WBCs (y=1.06x+0.09, n=67, R2=0.96) and mononuclear cells (MNs) (y=1.04x-0.01, n=40, R2=0.93) in CSF. However, the XN-1000 systematically counted more polymorphonuclear cells (PMNs) (y=1.48x+0.18, n=40, R2=0.99) compared to manual microscopy. Excellent correlation for RBCs >1×109/L (y=0.99x+116.56, n=26, R2=0.99) in CSF was found. For other fluids (CAPD, ascites and pleural fluid) excellent agreement was found for counting WBCs (y=1.06x+0.26, n=109, R2=0.98), MNs (y=1.06x-0.41, n=93, R2=0.96), PMNs (y=1.06x+0.81, n=93, R2=0.98) and RBCs (y=1.04x+110.04, n=43, R2=0.98). By using BF XN-check, the lower limit of quantitation (LLoQ) for WBC was defined at 5×106/L. Linearity was excellent for both the WBCs (R2=0.99) and RBCs (R2=0.99) and carry-over never exceeded 0.05%. The BF module on the XN-1000 is a suitable tool for fast and accurate quantification of WBC (differential) and RBC counts in CSF and other BFs in a diagnostic setting.

  16. Effect of the hemoglobin-based oxygen carrier HBOC-201 on laboratory instrumentation: cobas integra, chiron blood gas analyzer 840, Sysmex SE-9000 and BCT.

    PubMed

    Wolthuis, A; Peek, D; Scholten, R; Moreira, P; Gawryl, M; Clark, T; Westerhuis, L

    1999-01-01

    As part of a clinical trial, we evaluated the effects of the hemoglobin-based oxygen-carrier (HBOC) HBOC-201 (an ultrapurified, stroma-free bovine hemoglobin product, Biopure, Cambridge, MA, USA) on our routine clinical chemistry analyzer (Cobas Integra, F. Hoffmann-La Roche Ltd, Basel, Switzerland ), blood gas analyzer (Chiron 840, Chiron Diagnostics Corporation, East Walpole, MA, USA), routine hemocytometry analyzer (Sysmex SE-9000, TOA Medical Electronics Co Ltd., Kobe, Japan), hemostasis analyzer (BCT, Dade-Behring, Marburg, Germany) and bloodbanking system (Dia-Med-ID Micro Typing System, DiaMed AG, Cressier, Switzerland). The maximum tested concentration of HBOC-201 was 65 g/l. Of the 27 routine clinical chemistry tests challenged with HBOC-201, bilirubin-direct, creatine kinase MB-fraction (CK-MB), creatine kinase (CK), gamma-glutamyltransferase (GGT), magnesium and uric acid were influenced by even low concentrations of HBOC-201. These tests were excluded from use on the plasma of patients treated with HBOC-201. Since the non-availability of the cardiac marker CK-MB may lead to problems in acute situations, we introduced the qualitative Trop T-test (Boehringer Mannheim), which was not influenced. The applicability of another nine tests was limited by the concentration of the HBOC-201 in the patients' plasma. No interference of HBOC-201 in routine hemocytometry, hemostasis-analysis and red-blood cell agglutination detection (blood-bank tests) was observed. Although immediate patient-care was not compromised, routine use of hemoglobin-based oxygen carriers will have a strong impact on logistical management. The development of robust laboratory tests free from the interference of the pigmented oxygen carriers should therefore precede its introduction into routine transfusion medicine.

  17. Performance evaluation of the Sysmex pocH-100iV Diff hematology analyzer for analysis of canine, feline, equine, and bovine blood.

    PubMed

    Riond, Barbara; Weissenbacher, Stefan; Hofmann-Lehmann, Regina; Lutz, Hans

    2011-12-01

    The Sysmex pocH-100iV Diff is an impedance hematology analyzer recently introduced for point-of-care use in veterinary practices in Europe. The purpose of this study was to validate the pocH-100iV Diff for analysis of blood samples from dogs, cats, horses, and cattle. Fresh EDTA-blood samples from healthy and ill dogs (115), cats (94), horses (91), and cattle (78) were analyzed on the pocH-100iV Diff and the Cell-Dyn 3500. Results of the automated WBC differential counts were compared with the manual differential counts for 77 dogs, 65 cats, 40 horses, and 46 cattle. HCT were compared with PCVs obtained by microhematocrit centrifugation. Furthermore, precision, linearity, carry-over, cell aging, and clinical relevance of the pocH-100iV Diff results were assessed. Most of the CBC results obtained by the pocH-100iV Diff correlated well with those of the Cell-Dyn 3500. Slightly low correlation was observed for canine MCV and hemoglobin concentration. Lymphocytes correlated well in horses and cattle, but less well in cats and dogs. The mixed cell population termed "OTHRS" (all granulocytes and monocytes for horses and cattle; neutrophils, monocytes, and basophils for cats and dogs) correlated well in all tested species. The instrument overestimated feline and canine eosinophils. In cats, platelet counts showed a strong negative bias. The overall performance of the pocH-100iV Diff was excellent with the noted limitations. The automated differential count can be used as screening tool in conjunction with evaluation of a blood smear. © 2011 American Society for Veterinary Clinical Pathology.

  18. Reflex Testing Rules for Cell Count and Differentiation of Nucleated Elements in Pleural and Ascitic Fluids on Sysmex XE-5000.

    PubMed

    Buoro, Sabrina; Appassiti Esposito, Sara; Vavassori, Mauro; Mecca, Tommaso; Ottomano, Cosimo; Dominoni, Paola; Seghezzi, Michela; Candiago, Elisabetta; Farina, Claudio; Gianatti, Andrea; Crippa, Alberto; Lippi, Giuseppe

    2016-04-01

    Flow cytometry is widely used in many laboratories for automated nucleated cell counts and their differentiation in body fluids. The implementation of new reflex testing rules on these automated instruments could open new frontiers in laboratory workflow, improving characterization of body fluids and clinical diagnosis and decreasing costs. Ascitic (150) and pleural (33) fluids were collected and assessed by XE-5000 and optical microscopy. Cell counts performed with the methods showed a Pearson's correlation of 0.98 (p < 0.0001), Passing-Bablok regression y = 0.99x + 2.44, and bias of 32.3. In ascitic fluids, the best diagnostic performance was found for polymorphonuclear and neutrophil counts on XE-5000, which exhibited areas under the curve (AUCs) 0.98 (p < 0.0001) and 0.99 (p < 0.0001), respectively. In pleural fluids the best diagnostic performance was found for polymorphonuclear percent parameter, which displayed 0.97 (p < 0.0001). Specific reflex test rules based on these parameters were characterized by 92% diagnostic concordance, 1.00 sensitivity, and 0.84 specificity with optical microscopy. The application of a set of reflex testing rules may improve the diagnostic performance of XE-5000, increasing its reliability for routine automated cell count in body fluids. We acknowledge that further studies should be planned to validate our findings according to clinical data. © 2015 Society for Laboratory Automation and Screening.

  19. Evaluation of the automated hematology analyzer Sysmex XT-2000iV ™ compared to the ADVIA ® 2120 for its use in dogs, cats, and horses. Part II: Accuracy of leukocyte differential and reticulocyte count, impact of anticoagulant and sample aging.

    PubMed

    Bauer, Natali; Nakagawa, Julia; Dunker, Cathrin; Failing, Klaus; Moritz, Andreas

    2012-01-01

    The automated laser-based hematology analyzer Sysmex XT-2000iV™ provides a 5-part differential count and specific cytograms that are of great interest for large veterinary laboratories. The aim of the study was to validate the Sysmex XT-2000iV compared to the laser-based hematology analyzer ADVIA® 2120 and manual differential in dogs, cats, and horses as well as the impact of anticoagulant (heparin, ethylenediamine tetra-acetic acid [EDTA], and citrate) and storage at 22°C and 4°C. Consecutive fresh K(3)-EDTA blood samples from 216 cats, 314 dogs, and 174 horses were included. The impact of anticoagulant and sample storage was assessed in specimens obtained from an additional 9 cats, 10 dogs, and 10 horses. Agreement between both analyzers was excellent to good except for monocytes and canine reticulocytes. Spearman rank correlation coefficients (r (s)) between Sysmex XT-2000iV and manual differential were good to fair and ranged from 0.91 (cat lymphocytes) to 0.44 (cat monocytes). Hematocrit value (Hct), mean corpuscular hemoglobin (MCH), MCH concentration (MCHC; all: P < 0.001), and mean corpuscular volume (MCV; P < 0.01) were higher in canine citrated blood compared to heparin and EDTA. In cats, lymphocytes and monocytes were lower in heparinized blood compared to EDTA (P < 0.05), whereas in horses no significant effect was seen. Regarding storage time and temperature, white and red blood cell counts, hemoglobin, and MCH were stable. Hct, MCV, and MCHC were influenced by erythrocyte swelling. Differential count remained stable for 24 hr (22°C) and nearly 72 hr (4°C) except for monocytes. The overall performance of the Sysmex XT-2000iV was excellent and compared favorably with that of the ADVIA 2120. A special strength was the excellent detection of feline eosinophils.

  20. Evaluation and optimization of the extended information process unit (E-IPU) validation module integrating the sysmex flag systems and the recommendations of the French-speaking cellular hematology group (GFHC).

    PubMed

    Cornet, Edouard; Mullier, François; Despas, Noemie; Jacqmin, Hugues; Geara, Carole; Boubaya, Marouane; Chatelain, Bernard; Troussard, Xavier

    2016-10-01

    The French-Speaking Cellular Haematology Group (GFHC) recently published criteria for microscopic analysis of a blood smears when a hemogram is requested. In order to evaluate and improve these recommendations using an XN (Sysmex) analyzer, we assessed 31,836 samples categorized into two sub-groups of patients either receiving or not receiving care in the clinical hematology/oncology departments of two university hospitals. By combining the manufacturer's recommendations and the GFHC recommendations, 21.3% of samples had a positive review flag in phase 1 of our study (17,991 samples). In phase 2 (13,845 samples), increasing the immature granulocytes (IG) percentage from 5-10% as a review trigger threshold, and ignoring slides with isolated flags 'PLT HIGH' (thrombocytosis) or 'MCV LOW' (microcytosis) or 'Blast/Abn Lymph and Atypical Lymph' (blast cells/abnormal lymphocytes and atypical lymphocytes) (in the absence of abnormal cells on a previous blood smear within 72 h), enabled us to significantly reduce the number of slides reviewed from 21.3-15.0% (p < 0.0001), without loss of clinical value. This decrease occurred in both sub-groups (hematology 48.7-38.0%, non-hematology 18.3-11.7%, p < 0.0001). In conclusion, the application of the GFHC criteria adapted to XN analyzers has enabled us to optimize the hematology laboratory processes, and thus reduce the production costs and the turnaround time of hemogram results.

  1. Sepsis affects most routine and cell population data (CPD) obtained using the Sysmex XN-2000 blood cell analyzer: neutrophil-related CPD NE-SFL and NE-WY provide useful information for detecting sepsis.

    PubMed

    Park, S H; Park, C-J; Lee, B-R; Nam, K-S; Kim, M-J; Han, M-Y; Kim, Y J; Cho, Y-U; Jang, S

    2015-04-01

    The Sysmex XN-2000 analyzer can assess 36 routine and 57 cell population data (CPD) items. In this study, we evaluated these items as sepsis biomarkers. We enrolled 280 normal control (NC) and 130 sepsis patients. The sepsis patients were classified as uncomplicated or complicated sepsis. Routine and CPD items were determined, and the results were compared at between the NC and sepsis groups, uncomplicated and complicated sepsis groups, and survivors and nonsurvivors. For the detection of sepsis, CPD items NE-SFL [defined as the fluorescent light intensity of the neutrophil area on the WDF (white blood cell differential) scattergram] and NE-WY (defined as the fluorescent light distribution width of the neutrophil area on the WDF scattergram) showed comparative or higher AUC of 0.909 and 0.905, respectively, when compared with routine items such as hematocrit, hemoglobin, RBC, RDW, immature granulocytes count, lymphocytes count, and neutrophils count. For the discrimination of sepsis severity, only platelet-related items showed higher AUC (0.723 - 0.748) than lactic acid (0.695). For the prediction of 28-day mortality, only CV and SD of RDW showed higher AUC (0.766 and 0.732 each) than lactic acid (0.712). Sepsis patients demonstrated significant changes in routine and CPD items related to RBC, neutrophils, lymphocytes, and platelets when compared to NCs. Increase in CPD items NE-SFL and NE-WY, which may indicate neutrophil immaturity or activation, could be useful for the detection of sepsis patients, in conjunction with currently used surrogate sepsis biomarkers. However, these items did not efficiently contribute to the discrimination of sepsis severity or predict mortality. © 2014 John Wiley & Sons Ltd.

  2. Detection and quantification of hypo- and hypergranulated neutrophils on the new Sysmex XN hematology analyzer: establishment of an adapted reference interval for the neutrophil-granularity-intensity compared to XE-technology in adult patients.

    PubMed

    Zimmermann, Mathias; Steenhuis, Pieter; Linssen, Jo; Weimann, Andreas

    2015-01-01

    Since the recent introduction of Sysmex hematology analyzers of the XN-series it can be expected that the values of individual hematological parameters might differ between the new XN and the well-established XE platform. One such parameter is called Neutrophil-Granularity-Intensity or NEUT-GI on the XN-series and NEUT-X on the XE-series. Both parameters are used by clinicians to calculate the Granularity-Index (GI-Index), an important tool to detect hypo- or hypergranulated neutrophils occurring during myelodysplasia or inflammation. The aims of this study were to determine if previously reported reference intervals for NEUT-X can be used for NEUT-GI as well and if the GI-Indices on both analyzer platforms correlate with each other. NEUT-GI and NEUT-X were assessed in a set of 789 blood samples (n = 543 samples from adult intensive care units and n = 246 samples from adult "blood-healthy" control patients) and the corresponding Granularity-Indices were calculated for all samples using data obtained from XE-5000 and XN-1000 hematology analyzers. NEUT-GI and NEUT-X correlated significantly with each other (r2: 0.6512; p < 0.0001) with statistically significant higher values for NEUT-GI compared to NEUT-X in the control group (p < 0.0001) as well as in the ICU patients (p < 0.0001). This indicated that previously established reference intervals for NEUT-X cannot be used for NEUT-GI. In contrast, the GI-Indices showed no statistically significant difference between the analyzers in both groups. The GI-Indices were higher in the ICU patients compared to the control group on both analyzer platforms (p < 0.0001), as would be expected. Our study revealed the emphatic need for a new reference interval for NEUT-GI on the XN platform. The resulting 95% reference intervals were 140.91 - 160.46 channels for NEUT-GI and 129.20 - 142.33 channels for NEUT-X. The GI-Indices showed no significant statistical difference between the XN- and XE-series in both cohorts.

  3. Urine flow cytometry can rule out urinary tract infection, but cannot identify bacterial morphologies correctly.

    PubMed

    Geerts, N; Jansz, A R; Boonen, K J M; Wijn, R P W F; Koldewijn, E L; Boer, A K; Scharnhorst, V

    2015-08-25

    The diagnosis of urinary tract infection (UTI) by urine culture is a time-consuming and costly procedure. Usage of a screening method, to identify negative samples, would therefore affect time-to-diagnosis and laboratory cost positively. Urine flow cytometers are able to identify particles in urine. Together with the introduction of a cut-off value, which determines if a urine sample is subsequently cultured or not, the number of cultures can be reduced, while maintaining a low level of false negatives and a high negative predictive value. Recently, Sysmex developed additional software for their urine flow cytometers. Besides measuring the number of bacteria present in urine, information is given on bacterial morphology, which may guide the physician in the choice of antibiotic. In this study, we evaluated this software update. The UF1000i classifies bacteria into two categories: 'rods' and 'cocci/mixed'. Compared to the actual morphology of the bacterial pathogen found, the 'rods' category scores reasonably well with 91% chance of classifying rod-shaped bacteria correctly. The 'cocci/mixed' category underperforms, with only 29% of spherical-shaped bacteria (cocci) classified as such. In its current version, the bacterial morphology software does not classify bacteria, according to their morphology, well enough to be of clinical use in this study population.

  4. Rarefied Flow

    NASA Technical Reports Server (NTRS)

    Moss, James N.; Lengrand, Jean-Claude

    1998-01-01

    Rarefaction effects are important for hypersonic applications for a wide spectrum of conditions ranging from low-density (high altitude) situations to relatively high-density flows where the characteristic dimension is small. The present chapter concentrates on two hypersonic flow problems at flow conditions that produce a significant range of rarefaction effects: corner flow with jet interaction and blunt body flow with special emphasis on the near wake, These problems were chosen because they involve complex flow interactions that have significant implications for both spacecraft and re-entry vehicles. In an effort to clarify issues associated with these two general flow problems and to enhance their respective databases, both experimental and computational contributions were executed by an international group of researchers. In some cases, multiple data sources for both experimental and computational contributions are achieved.

  5. Rarefied Flow

    NASA Technical Reports Server (NTRS)

    Moss, James N.; Lengrand, Jean-Claude

    1998-01-01

    Rarefaction effects are important for hypersonic applications for a wide spectrum of conditions ranging from low-density (high altitude) situations to relatively high-density flows where the characteristic dimension is small. The present chapter concentrates on two hypersonic flow problems at flow conditions that produce a significant range of rarefaction effects: corner flow with jet interaction and blunt body flow with special emphasis on the near wake, These problems were chosen because they involve complex flow interactions that have significant implications for both spacecraft and re-entry vehicles. In an effort to clarify issues associated with these two general flow problems and to enhance their respective databases, both experimental and computational contributions were executed by an international group of researchers. In some cases, multiple data sources for both experimental and computational contributions are achieved.

  6. Flow visualization

    NASA Technical Reports Server (NTRS)

    Weinstein, Leonard M.

    1991-01-01

    Flow visualization techniques are reviewed, with particular attention given to those applicable to liquid helium flows. Three techniques capable of obtaining qualitative and quantitative measurements of complex 3D flow fields are discussed including focusing schlieren, particle image volocimetry, and holocinematography (HCV). It is concluded that the HCV appears to be uniquely capable of obtaining full time-varying, 3D velocity field data, but is limited to the low speeds typical of liquid helium facilities.

  7. Flow visualization

    NASA Astrophysics Data System (ADS)

    Weinstein, Leonard M.

    Flow visualization techniques are reviewed, with particular attention given to those applicable to liquid helium flows. Three techniques capable of obtaining qualitative and quantitative measurements of complex 3D flow fields are discussed including focusing schlieren, particle image volocimetry, and holocinematography (HCV). It is concluded that the HCV appears to be uniquely capable of obtaining full time-varying, 3D velocity field data, but is limited to the low speeds typical of liquid helium facilities.

  8. Flow chamber

    DOEpatents

    Morozov, Victor [Manassas, VA

    2011-01-18

    A flow chamber having a vacuum chamber and a specimen chamber. The specimen chamber may have an opening through which a fluid may be introduced and an opening through which the fluid may exit. The vacuum chamber may have an opening through which contents of the vacuum chamber may be evacuated. A portion of the flow chamber may be flexible, and a vacuum may be used to hold the components of the flow chamber together.

  9. Rock flows

    NASA Technical Reports Server (NTRS)

    Matveyev, S. N.

    1986-01-01

    Rock flows are defined as forms of spontaneous mass movements, commonly found in mountainous countries, which have been studied very little. The article considers formations known as rock rivers, rock flows, boulder flows, boulder stria, gravel flows, rock seas, and rubble seas. It describes their genesis as seen from their morphological characteristics and presents a classification of these forms. This classification is based on the difference in the genesis of the rubbly matter and characterizes these forms of mass movement according to their source, drainage, and deposit areas.

  10. Network Flows

    DTIC Science & Technology

    1988-12-01

    Researchers have suggested other solution strategies, using ideas from nonlinear progamming for solving this general separable convex cost flow problems. Some...plane methods and branch and bound procedures of integer programming, primal-dual methods of linear and nonlinear programming, and polyhedral methods...Combinatorial Optimization: Networks and Matroids), Bazaraa and Jarvis [1978] (Linear Programming and Network Flows), Minieka [1978] (Optimization Algorithms for

  11. Debris Flow

    NASA Image and Video Library

    2015-04-14

    This image captured by NASA 2001 Mars Odyssey spacecraft shows downslope movement of material from the hill at the top of the image. Linear ridges and channels are visible on the surface to the debris flow deposit.

  12. Thermocapillary flow without return flow-linear flow

    NASA Astrophysics Data System (ADS)

    Ospennikov, N. A.; Schwabe, D.

    The experimental realization of thermocapillary flow without return flow is reported. This type of flow (linear flow) was proposed and analyzed theoretically by Smith and Davis (J. Fluid Mech., 132:119-144, 1983). We suppressed the return flow by providing channels and side channels with lower flow resistance compared to that of the return flow. Cooling the layer with linear flow from above results in the Marangoni instability of longitudinal rolls as the most dangerous mode. Strong linear flow stabilizes the system against longitudinal rolls. We report preliminary results on the threshold and on the wavelength of the longitudinal rolls.

  13. Lubrication Flows.

    ERIC Educational Resources Information Center

    Papanastasiou, Tasos C.

    1989-01-01

    Discusses fluid mechanics for undergraduates including the differential Navier-Stokes equations, dimensional analysis and simplified dimensionless numbers, control volume principles, the Reynolds lubrication equation for confined and free surface flows, capillary pressure, and simplified perturbation techniques. Provides a vertical dip coating…

  14. Flow cytometer

    DOEpatents

    Van den Engh, G.

    1995-11-07

    A Faraday cage is described which encloses the flow chamber of a cytometer. Ground planes associated with each field deflection plate inhibit electric fields from varying the charge on designated events/droplets and further concentrates. They also increase forces applied to a passing charged event for accurate focus while concomitantly inhibiting a potential shock hazard. 4 figs.

  15. Lubrication Flows.

    ERIC Educational Resources Information Center

    Papanastasiou, Tasos C.

    1989-01-01

    Discusses fluid mechanics for undergraduates including the differential Navier-Stokes equations, dimensional analysis and simplified dimensionless numbers, control volume principles, the Reynolds lubrication equation for confined and free surface flows, capillary pressure, and simplified perturbation techniques. Provides a vertical dip coating…

  16. Flow cytometer

    DOEpatents

    van den Engh, Ger

    1995-01-01

    A Faraday cage enclosing the flow chamber of a cytometer and ground planes associated with each field deflection plate in concert therewith inhibit electric fields from varying the charge on designated events/droplets and further concentrates and increases forces applied to a charged event passing therethrough for accurate focus thereof while concomitantly inhibiting a potential shock hazard.

  17. Gender's equality in evaluation of urine particles: Results of a multicenter study of the Italian Urinalysis Group.

    PubMed

    Manoni, Fabio; Gessoni, Gianluca; Alessio, Maria Grazia; Caleffi, Alberta; Saccani, Graziella; Epifani, Maria Grazia; Tinello, Agostino; Zorzan, Tatiana; Valverde, Sara; Caputo, Marco; Lippi, Giuseppe

    2014-01-01

    We performed a multicenter study to calculate the upper reference limits (URL) for urine particle quantification in mid-stream samples by using automated urine analyzers. Two laboratories tested 283 subjects using a Sysmex UF-100, two other laboratories tested 313 subjects using Sysmex UF-1000i, whereas two other laboratories tested 267 subjects using Iris IQ®200. The URLs of UF-100 in females and males were 7.8/μL and 6.7/μL for epithelial cells (EC), 11.1/μL and 9.9/μL for red blood cells (RBC), 10.2/μL and 9.7/μL for white blood cells (WBC), and 0.85/μL and 0.87/μL for cylinders (CAST). The URLs of UF-1000i in females and males were 7.6/μL and 7.1/μL for EC, 12.2/μL and 11.1/μL for RBC, 11.9/μL and 11.7/μL for WBC, and 0.88/μL and 0.86/μL for CAST. The URLs of Iris IQ®200 in females and males were 7.8/μL and 6.6/μL for EC, 12.4/μL and 10.1/μL for RBC, 10.9/μL and 9.9/μL for WBC, and 1.1/μL and 1.0/μL for CAST. The URLs obtained in this study were comparable to the lowest values previously reported in the literature. Moreover, no gender-related difference was observed, and analyzer-specific upper reference limits were very similar. © 2013.

  18. Flow Separation

    DTIC Science & Technology

    1975-11-01

    Born, Constantin Caratheodory, Richard Couiant, Kurt Friedrichs, Werner Heisenberg, Gustav Herglotz, Erich von Hoist, Pascual Jordan, Walther Nernst...existence of these two flow regimes in boundary layers was discovered by PRANDTL when EIFFEL [8] published in 1912 his measurements on the drag of...simultaneously by G. EIFFEL in Paris and became so successful that other wind tunnels were modelled after it in many countries. Fig. 18 gives an impression of

  19. Flow Control

    DTIC Science & Technology

    2013-04-08

    capture the asymmetric vortex dynamics . These methods were validated by time and fre- quency domain methods . The measurements and modeling methods ...and are time invariant. Protrusions or intrusions will be added along the body’s geometry to induce some type of flow change . These methods yield only...The lag time or presence of non- minimum phase are difficult issues to decouple in the dynamics so further analysis techniques are necessary. 86

  20. Lava Flows

    NASA Technical Reports Server (NTRS)

    2006-01-01

    [figure removed for brevity, see original site] Context image for PIA03658 Lava Flows

    These relatively young lava flows are part of Arsia Mons.

    Image information: VIS instrument. Latitude -22.5N, Longitude 242.3E. 17 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  1. Lava Flows

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site] Context image for PIA03054 Lava Flows

    The lava flows in this image are only a very small part of the voluminous lava erupted from the Arsia Mons volcano.

    Image information: VIS instrument. Latitude 19.1S, Longitude 244.5E. 17 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  2. Flow Cage Assemblies

    NASA Technical Reports Server (NTRS)

    Sherrit, Stewart (Inventor); Badescu, Mircea (Inventor); Bao, Xiaoqi (Inventor); Bar-Cohen, Yoseph (Inventor)

    2017-01-01

    Apparatus, systems and methods for implementing flow cages and flow cage assemblies in association with high pressure fluid flows and fluid valves are provided. Flow cages and flow assemblies are provided to dissipate the energy of a fluid flow, such as by reducing fluid flow pressure and/or fluid flow velocity. In some embodiments the dissipation of the fluid flow energy is adapted to reduce erosion, such as from high-pressure jet flows, to reduce cavitation, such as by controllably increasing the flow area, and/or to reduce valve noise associated with pressure surge.

  3. Environment Flow Assessment with Flow Regime Transition

    NASA Astrophysics Data System (ADS)

    Su, J.; Ho, C. C.; Chang, L. C.

    2015-12-01

    To avoid worsen river and estuarine ecosystems cause by overusing water resources, environmental flows conservation is applied to reduce the impact of river environment. Environmental flows refer to water provided within a river, wetland or coastal zone to sustain ecosystems and benefits to human wellbeing. Environment flow assessment is now widely accepted that a naturally variable flow regime, rather than just a minimum low flow. In this study, we propose four methods, experience method, Tenant method, hydraulic method and habitat method to assess the environmental flow of base flow, flush flow and overbank flow with different discharge, frequency and occurrence period. Dahan River has been chosen as a case to demonstrate the assessment mechanism. The alternatives impact analysis of environment and human water used provides a reference for stakeholders when holding an environmental flow consultative meeting.

  4. Flow distances on open flow networks

    NASA Astrophysics Data System (ADS)

    Guo, Liangzhu; Lou, Xiaodan; Shi, Peiteng; Wang, Jun; Huang, Xiaohan; Zhang, Jiang

    2015-11-01

    An open flow network is a weighted directed graph with a source and a sink, depicting flux distributions on networks in the steady state mode of an open flow system. Energetic food webs, economic input-output networks, and international trade networks are open flow network models of energy flows between species, money or value flows between industrial sectors, and goods flows between countries, respectively. An open flow network is different from a closed flow network because it considers the flows from or to the environment (the source and the sink). For instance, in energetic food webs, species obtain energy not only from other species but also from the environment (sunlight), and species also dissipate energy to the environment. Flow distances between any two nodes i and j are defined as the average number of transition steps of a random walker along the network from i to j. The conventional method for the calculation of the random walk distance on closed flow networks cannot be applied to open flow networks. Therefore, we derive novel explicit expressions for flow distances of open flow networks according to their underlying Markov matrix of the network in this paper. We apply flow distances to two types of empirical open flow networks, including energetic food webs and economic input-output networks. In energetic food webs, we visualize the trophic level of each species and compare flow distances with other distance metrics on the graph. In economic input-output networks, we rank sectors according to their average flow distances and cluster sectors into different industrial groups with strong connections. Other potential applications and mathematical properties are also discussed. To summarize, flow distance is a useful and powerful tool to study open flow systems.

  5. The Importance of Nucleated Red Blood Cells in Patients with Beta Thalassemia Major and Comparison of Two Automated Systems with Manual Microscopy and Flow Cytometry.

    PubMed

    Karakukcu, Musa; Karakukcu, Cigdem; Unal, Ekrem; Ozturk, Ahmet; Ciraci, Zahid; Patiroglu, Turkan; Ozdemir, Mehmet Akif

    2015-01-01

    Nucleated red blood cells (NRBC) can be used as a marker of erythropoietic stress and help optimize transfusion therapy in patients with beta thalassemia major. The aim of this study was to determine this correlation; and compare two automated systems (Sysmex XE-2100, and Advia 2120i) with manual microscopy and flow cytometry (FCM). Absolute NRBC counts and percentages (NRBC%) from 51 patients were analyzed with both automated and reference methods. The results were compared with levels of pre-transfusion hemoglobin and ferritin levels. The mean age of the included patients (31 female, 20 male) were 12.9 ± 7.5 years. Mean levels of hemoglobin and ferritin were 9.5 ± 1.2 g/dL and 1896 ± 1194 ng/mL respectively. The NRBC% of two instruments did not significantly differ and correlated well (p < 0.0001, r2 = 0.984). NRBC% obtained with the XE-2100 and Advia 2120i versus manual microscopy also yielded high correlations (r2 = 0.951 and r2 0.981, respectively); however, absolute NRBC counts versus FCM yielded lower coefficients (r2 = 0.723 and r2 = 0.694, respectively). High serum ferritin levels were correlated with both NRBC% and counts with both instruments (p < 0.001) and hemoglobin levels lower than 9.0 g/dL had a negative correlation with NRBC% and NRBC counts with the Advia 2120i (p < 0.05, r = -0.495) but not with the XE-2100. Monitoring of NRBC% with both instruments can help optimize transfusion therapy for patients with beta thalassemia major. Following the NRBC% is more efficient than absolute counts.

  6. Variable orifice flow regulator

    NASA Technical Reports Server (NTRS)

    Christianson, Rollin C. (Inventor)

    1991-01-01

    A flow regulator for high-pressure fluids at elevated temperatures includes a body having a flow passage extending between inlet and outlet openings. First and second orifice members are arranged in the flow passage so at least one of the orifice members can be moved transversely in relation to the flow passage between one operating position where the two orifice openings are aligned for establishing a maximum flow rate of fluids flowing through the flow passage and at least one other operating position in which the two openings are moderately misaligned with one another for establishing a predetermined reduced flow rate of fluids flowing through the flow passage.

  7. Flow direction determination of lava flows.

    NASA Technical Reports Server (NTRS)

    Smith, E. I.; Rhodes, R. C.

    1972-01-01

    The flow direction technique, previously applied to ash-flow sheets, can be used to determine direction of movement and locate eruptive centers for lava flows. The method provides statistically stronger and more consistent flow direction data for lava than ash-flow tuff. The accuracy and reliability of the technique was established on the porphyritic basaltic andesite of Mount Taylor, New Mexico, which erupted from a known center, the Mount Taylor Amphitheater. The technique was then applied to volcanic units with unknown sources: the John Kerr Peak Quartz Latite and mid-Tertiary andesite flows in the Mogollon Mountains, both in southwestern New Mexico. The flow direction technique indicated flow patterns and suggested source areas for each rock unit. In the Mogollon Mountains flow direction measurements were supported by independent directional criteria such as dips of cross beds, stratigraphic thickening, facies changes, and megascopic textures.-

  8. Flow Instability in Baffled Channel Flow

    NASA Astrophysics Data System (ADS)

    Kang, Changwoo; Yang, Kyung-Soo; Lee, Kyongjun

    2010-11-01

    Flow instability of baffled channel flow, where thin baffles are mounted on both channel walls periodically in the direction of the main flow, has been numerically investigated. Flow in a baffled channel is regarded as a simple model for flow in finned heat exchangers, including micro channels. In baffled channel flow, flow characteristics are significantly affected by geometrical configuration of the baffles. Two key parameters were considered, namely baffle interval (L) and Reynolds number (Re) of the main flow. The baffle height is fixed as one quarter of the channel height (H). By using a parametric study, we elucidate dependency of the primary instability, a Hopf bifurcation from steady to a time-periodic flow, on L. It turned out that the most unstable flow is obtained with L/H=3. Transition of two-dimensional (2D) time-periodic flow to three-dimensional (3D) flow is initiated by a secondary instability (SI). Floquet stability analysis was performed to identify the critical Reynolds number of SI for some selected baffle intervals. Several distinct modes were identified, and dependency of SI on L was elucidated. A 3D simulation was finally carried out to confirm the Floquet analysis. The current results shed light on understanding flow characteristics of a finned heat exchanger.

  9. Low volume flow meter

    DOEpatents

    Meixler, Lewis D.

    1993-01-01

    The low flow monitor provides a means for determining if a fluid flow meets a minimum threshold level of flow. The low flow monitor operates with a minimum of intrusion by the flow detection device into the flow. The electrical portion of the monitor is externally located with respect to the fluid stream which allows for repairs to the monitor without disrupting the flow. The electronics provide for the adjustment of the threshold level to meet the required conditions. The apparatus can be modified to provide an upper limit to the flow monitor by providing for a parallel electronic circuit which provides for a bracketing of the desired flow rate.

  10. Laminar Flow Aircraft Certification

    NASA Technical Reports Server (NTRS)

    Williams, Louis J. (Compiler)

    1986-01-01

    Various topics telative to laminar flow aircraft certification are discussed. Boundary layer stability, flaps for laminar flow airfoils, computational wing design studies, manufacturing requirements, windtunnel tests, and flow visualization are among the topics covered.

  11. Multiphase flow calculation software

    DOEpatents

    Fincke, James R.

    2003-04-15

    Multiphase flow calculation software and computer-readable media carrying computer executable instructions for calculating liquid and gas phase mass flow rates of high void fraction multiphase flows. The multiphase flow calculation software employs various given, or experimentally determined, parameters in conjunction with a plurality of pressure differentials of a multiphase flow, preferably supplied by a differential pressure flowmeter or the like, to determine liquid and gas phase mass flow rates of the high void fraction multiphase flows. Embodiments of the multiphase flow calculation software are suitable for use in a variety of applications, including real-time management and control of an object system.

  12. Relaminarization of fluid flows

    NASA Technical Reports Server (NTRS)

    Narasimha, R.; Sreenivasan, K. R.

    1979-01-01

    The mechanisms of the relaminarization of turbulent flows are investigated with a view to establishing any general principles that might govern them. Three basic archetypes of reverting flows are considered: the dissipative type, the absorptive type, and the Richardson type exemplified by a turbulent boundary layer subjected to severe acceleration. A number of other different reverting flows are then considered in the light of the analysis of these archetypes, including radial Poiseuille flow, convex boundary layers, flows reverting by rotation, injection, and suction, as well as heated horizontal and vertical gas flows. Magnetohydrodynamic duct flows are also examined. Applications of flow reversion for turbulence control are discussed.

  13. Flow structure in continuous flow electrophoresis chambers

    NASA Technical Reports Server (NTRS)

    Deiber, J. A.; Saville, D. A.

    1982-01-01

    There are at least two ways that hydrodynamic processes can limit continiuous flow electrophoresis. One arises from the sensitivity of the flow to small temerature gradients, especially at low flow rates and power levels. This sensitivity can be suppressed, at least in principle, by providing a carefully tailored, stabilizing temperature gradient in the cooling system that surrounds the flow channel. At higher power levels another limitation arises due to a restructuring of the main flow. This restructuring is caused by buoyancy, which is in turn affected by the electro-osmotic crossflow. Approximate solutions to appropriate partial differential equations have been computed by finite difference methods. One set of results is described here to illustrate the strong coupling between the structure of the main (axial) flow and the electro-osmotic flow.

  14. Evolution and Flow.

    ERIC Educational Resources Information Center

    Csikszentmihalyi, Mihaly

    1997-01-01

    Presents flow theory in the context of evolution. Defines the elements of "flow" and contends that flow results in an optimal state of inner harmony which improves one's chance for survival. Identifies consequences of flow for creativity, peak performance, talent development, productivity, self-esteem, and stress reduction. Examines the…

  15. Brain-Flow Writing.

    ERIC Educational Resources Information Center

    Peterson, Robert J.

    The brain-flow writing technique, which might also be called the "fast flow" technique, offers a particularly useful means of helping adults overcome writer's block. It also offers some bonuses in the form of enhanced creativity, improved thought-flow, and much faster writing output. There are six steps to brain-flow writing. In the…

  16. Portable wastewater flow meter

    DOEpatents

    Hunter, Robert M.

    1999-02-02

    A portable wastewater flow meter particularly adapted for temporary use at a single location in measuring the rate of liquid flow in a circular entrance conduit of a sewer manhole both under free flow and submerged, open channel conditions and under fill pipe, surcharged conditions, comprising an apparatus having a cylindrical external surface and an inner surface that constricts the flow through the apparatus in such a manner that a relationship exists between (1) the difference between the static pressure head of liquid flowing through the entrance of the apparatus and the static pressure head of liquid flowing through the constriction, and (2) the rate of liquid flow through the apparatus.

  17. Portable wastewater flow meter

    DOEpatents

    Hunter, Robert M.

    1990-01-01

    A portable wastewater flow meter particularly adapted for temporary use at a single location in measuring the rate of liquid flow in a circular entrance conduit of a sewer manhole both under free flow and submerged, open channel conditions and under full pipe, surcharged conditions, comprising an apparatus having a cylindrical external surface and an inner surface that constricts the flow through the apparatus in such a manner that a relationship exists between (1) the difference between the static pressure head of liquid flowing through the entrance of the apparatus and the static pressure head of liquid flowing through the constriction, and (2) the rate of liquid flow through the apparatus.

  18. Portable wastewater flow meter

    SciTech Connect

    Hunter, Robert M.

    1999-02-02

    A portable wastewater flow meter particularly adapted for temporary use at a single location in measuring the rate of liquid flow in a circular entrance conduit of a sewer manhole both under free flow and submerged, open channel conditions and under fill pipe, surcharged conditions, comprising an apparatus having a cylindrical external surface and an inner surface that constricts the flow through the apparatus in such a manner that a relationship exists between (1) the difference between the static pressure head of liquid flowing through the entrance of the apparatus and the static pressure head of liquid flowing through the constriction, and (2) the rate of liquid flow through the apparatus.

  19. Intelligent Flow Control Valve

    NASA Technical Reports Server (NTRS)

    Kelley, Anthony R (Inventor)

    2015-01-01

    The present invention is an intelligent flow control valve which may be inserted into the flow coming out of a pipe and activated to provide a method to stop, measure, and meter flow coming from the open or possibly broken pipe. The intelligent flow control valve may be used to stop the flow while repairs are made. Once repairs have been made, the valve may be removed or used as a control valve to meter the amount of flow from inside the pipe. With the addition of instrumentation, the valve may also be used as a variable area flow meter and flow controller programmed based upon flowing conditions. With robotic additions, the valve may be configured to crawl into a desired pipe location, anchor itself, and activate flow control or metering remotely.

  20. Flow mapping of the mercury flow

    NASA Astrophysics Data System (ADS)

    Takeda, Y.; Kikura, H.

    An ultrasonic velocity profile (UVP) method has been successfully applied to the investigation of mercury flow contained in a stainless steel wall in the configuration of a liquid metal target of a spallation neutron source called SINQ at the Paul Scherrer Institute. One- and two-dimensional stationary flow has been fully investigated in the form of velocity profiles. Using velocity profiles obtained by the UVP method, a two-dimensional flow map was efficiently produced. A steady state vector map was successfully made and time dependent flow mapping is feasible.

  1. Reactive flow in solids

    NASA Astrophysics Data System (ADS)

    Brassart, Laurence; Suo, Zhigang

    2013-01-01

    When guest atoms diffuse into a host solid and react, the host may flow inelastically. Often a reaction can stimulate flow in a host too brittle to flow under a mechanical load alone. We formulate a theory of reactive flow in solids by regarding both flow and reaction as nonequilibrium processes, and placing the driving forces for flow and reaction on equal footing. We construct chemomechanical rate-dependent kinetic models without yield strength. In a host under constant stress and chemical potential, flow will persist indefinitely, but reaction will arrest. We also construct chemomechanical yield surface and flow rule by extending the von Mises theory of plasticity. We show that the host under a constant deviatoric stress will flow gradually in response to ramp chemical potential, and will ratchet in response to cyclic chemical potential.

  2. Compressible Flow Toolbox

    NASA Technical Reports Server (NTRS)

    Melcher, Kevin J.

    2006-01-01

    The Compressible Flow Toolbox is primarily a MATLAB-language implementation of a set of algorithms that solve approximately 280 linear and nonlinear classical equations for compressible flow. The toolbox is useful for analysis of one-dimensional steady flow with either constant entropy, friction, heat transfer, or Mach number greater than 1. The toolbox also contains algorithms for comparing and validating the equation-solving algorithms against solutions previously published in open literature. The classical equations solved by the Compressible Flow Toolbox are as follows: The isentropic-flow equations, The Fanno flow equations (pertaining to flow of an ideal gas in a pipe with friction), The Rayleigh flow equations (pertaining to frictionless flow of an ideal gas, with heat transfer, in a pipe of constant cross section), The normal-shock equations, The oblique-shock equations, and The expansion equations.

  3. Generalized radial flow in synthetic flow systems.

    PubMed

    Bowman, Dale O; Roberts, Randall M; Holt, Robert M

    2013-01-01

    Traditional analysis methods used to determine hydraulic properties from pumping tests work well in many porous media aquifers, but they often do not work in heterogeneous and fractured-rock aquifers, producing non-plausible and erroneous results. The generalized radial flow model developed by Barker (1988) can reveal information about heterogeneity characteristics and aquifer geometry from pumping test data by way of a flow dimension parameter. The physical meaning of non-integer flow dimensions has long been a subject of debate and research. We focus on understanding and interpreting non-radial flow through high permeability conduits within fractured aquifers. We develop and simulate flow within idealized non-radial flow conduits and expand on this concept by simulating pumping in non-fractal random fields with specific properties that mimic persistent sub-radial flow responses. Our results demonstrate that non-integer flow dimensions can arise from non-fractal geometries within aquifers. We expand on these geometric concepts and successfully simulate pumping in random fields that mimic well-test responses seen in the Culebra Dolomite above the Waste Isolation Pilot Plant. © 2012, The Author(s). Groundwater © 2012, National Ground Water Association.

  4. Unsteady flow volumes

    SciTech Connect

    Becker, B.G.; Lane, D.A.; Max, N.L.

    1995-03-01

    Flow volumes are extended for use in unsteady (time-dependent) flows. The resulting unsteady flow volumes are the 3 dimensional analog of streamlines. There are few examples where methods other than particle tracing have been used to visualize time varying flows. Since particle paths can become convoluted in time there are additional considerations to be made when extending any visualization technique to unsteady flows. We will present some solutions to the problems which occur in subdivision, rendering, and system design. We will apply the unsteady flow volumes to a variety of field types including moving multi-zoned curvilinear grids.

  5. Dynamic power flow controllers

    DOEpatents

    Divan, Deepakraj M.; Prasai, Anish

    2017-03-07

    Dynamic power flow controllers are provided. A dynamic power flow controller may comprise a transformer and a power converter. The power converter is subject to low voltage stresses and not floated at line voltage. In addition, the power converter is rated at a fraction of the total power controlled. A dynamic power flow controller controls both the real and the reactive power flow between two AC sources having the same frequency. A dynamic power flow controller inserts a voltage with controllable magnitude and phase between two AC sources; thereby effecting control of active and reactive power flows between two AC sources.

  6. Quantitative Flow Visualization in Unseeded Flows

    NASA Astrophysics Data System (ADS)

    Miles, Richard B.; Lempert, Walter R.

    The various tools for flow visualization have been significantly expanded over the past several years through the use of molecular scattering and molecular laser-induced fluorescence. These approaches have added the capability of sampling individual small volume elements within a flow, and by using cameras for detection, they are easily extended to sample lines and cross-sectional planes. This localized measurement capability means that these approaches can be made quantitative even in complex and/or unsteady flow fields. If the molecular species is naturally occurring, such as oxygen or nitrogen in air, then no seeding is required. Furthermore, in these applications, images of the flow can be frozen in time by using a short pulse laser for illumination. The distribution of the molecules reflects the true physics of the flow, so even raw images taken in this manner give an immediate understanding of flow field properties. With proper calibration, the images can be further analyzed to yield quantitative information about the flow. In the case of flow tagging, the analysis gives velocity profiles when lines are written, and deformation, vorticity, and dilation with grid patterns. Molecular scattering can be used to give quantitative values of density, temperature, and two-dimensional velocity. This paper presents three such molecular-based approaches: laser-induced fluorescence from oxygen, flow tagging by oxygen excitation, and Rayleigh scattering. These three approaches are chosen because all three can be used in naturally occurring air with no seeding. The raw data from each of these approaches gives an immediate appreciation of the flow structure and further analysis yields accurate values of velocity, temperature, and density. These approaches use readily available laser sources; however, they will be greatly enhanced with new source technologies that are currently under development.

  7. Numerical flow analysis for axial flow turbine

    NASA Astrophysics Data System (ADS)

    Sato, T.; Aoki, S.

    Some numerical flow analysis methods adopted in the gas turbine interactive design system, TDSYS, are described. In the TDSYS, a streamline curvature program for axisymmetric flows, quasi 3-D and fully 3-D time marching programs are used respectively for blade to blade flows and annular cascade flows. The streamline curvature method has some advantages in that it can include the effect of coolant mixing and choking flow conditions. Comparison of the experimental results with calculated results shows that the overall accuracy is determined more by the empirical correlations used for loss and deviation than by the numerical scheme. The time marching methods are the best choice for the analysis of turbine cascade flows because they can handle mixed subsonic-supersonic flows with automatic inclusion of shock waves in a single calculation. Some experimental results show that a time marching method can predict the airfoil surface Mach number distribution more accurately than a finite difference method. One weakpoint of the time marching methods is a long computer time; they usually require several times as much CPU time as other methods. But reductions in computer costs and improvements in numerical methods have made the quasi 3-D and fully 3-D time marching methods usable as design tools, and they are now used in TDSYS.

  8. Peak flow meter (image)

    MedlinePlus

    A peak flow meter is commonly used by a person with asthma to measure the amount of air that can be ... become narrow or blocked due to asthma, peak flow values will drop because the person cannot blow ...

  9. Urination - difficulty with flow

    MedlinePlus

    ... gov/ency/article/003143.htm Urination - difficulty with flow To use the sharing features on this page, ... at night? Has the force of your urine flow decreased? Do you have dribbling or leaking urine? ...

  10. Handbook of flow visualization

    NASA Astrophysics Data System (ADS)

    Yang, Wen-Jei

    The present conference flow visualization encompasses the fundamental principles of visualization, methods for visualizing different flow types, image processing and computer-assisted methods, and a number of practical applications of the methodologies for studying heat transfer, gas-turbine-disk cooling flows, indoor environments, building aerodynamics, and land vehicles. Specific issues addressed include fluid dynamics, the basics of heat and mass transfer, electrical discharges, liquid crystals, streaming birefringence, speckle photography, Schlieren methods, surface tracing, planar fluorescence imaging in gases, digital processing in interferograms, and ultrasonic image processing. Also addressed are computer-aided flow visualization, flow-field survey data, thermography, flow solutions with scalar variable presentation, and special applications including aerospace and wind-tunnel testing, internal flows, and explosive flows such as shock tubes and blast waves.

  11. A Nonideal Flow Experiment.

    ERIC Educational Resources Information Center

    Gonzalez-Velasco, Juan Ramon; Elorriaga, Javier Bilbao

    1984-01-01

    Considers the deviation from the ideal flows of both a backmix tank and a backmix tank followed by a flow vessel. Background information, apparatus used, and experimental procedures are provided. Typical results are also provided and discussed. (JN)

  12. Guide tube flow diffuser

    SciTech Connect

    Berringer, R.T.; Myron, D.L.

    1980-11-04

    A nuclear reactor upper internal guide tube has a flow diffuser integral with its bottom end. The guide tube provides guidance for control rods during their ascent or descent from the reactor core. The flow diffuser serves to divert the upward flow of reactor coolant around the outside of the guide tube thereby limiting the amount of coolant flow and turbulence within the guide tube, thus enhancing the ease of movement of the control rods.

  13. Ultrasonic flow metering system

    DOEpatents

    Gomm, Tyler J.; Kraft, Nancy C.; Mauseth, Jason A.; Phelps, Larry D.; Taylor, Steven C.

    2002-01-01

    A system for determining the density, flow velocity, and mass flow of a fluid comprising at least one sing-around circuit that determines the velocity of a signal in the fluid and that is correlatable to a database for the fluid. A system for determining flow velocity uses two of the inventive circuits with directional transmitters and receivers, one of which is set at an angle to the direction of flow that is different from the others.

  14. Elbow mass flow meter

    DOEpatents

    McFarland, Andrew R.; Rodgers, John C.; Ortiz, Carlos A.; Nelson, David C.

    1994-01-01

    Elbow mass flow meter. The present invention includes a combination of an elbow pressure drop generator and a shunt-type mass flow sensor for providing an output which gives the mass flow rate of a gas that is nearly independent of the density of the gas. For air, the output is also approximately independent of humidity.

  15. Blood Flow in Arteries

    NASA Astrophysics Data System (ADS)

    Ku, David N.

    Blood flow in arteries is dominated by unsteady flow phenomena. The cardiovascular system is an internal flow loop with multiple branches in which a complex liquid circulates. A nondimensional frequency parameter, the Womersley number, governs the relationship between the unsteady and viscous forces. Normal arterial flow is laminar with secondary flows generated at curves and branches. The arteries are living organs that can adapt to and change with the varying hemodynamic conditions. In certain circumstances, unusual hemodynamic conditions create an abnormal biological response. Velocity profile skewing can create pockets in which the direction of the wall shear stress oscillates. Atherosclerotic disease tends to be localized in these sites and results in a narrowing of the artery lumena stenosis. The stenosis can cause turbulence and reduce flow by means of viscous head losses and flow choking. Very high shear stresses near the throat of the stenosis can activate platelets and thereby induce thrombosis, which can totally block blood flow to the heart or brain. Detection and quantification of stenosis serve as the basis for surgical intervention. In the future, the study of arterial blood flow will lead to the prediction of individual hemodynamic flows in any patient, the development of diagnostic tools to quantify disease, and the design of devices that mimic or alter blood flow. This field is rich with challenging problems in fluid mechanics involving three-dimensional, pulsatile flows at the edge of turbulence.

  16. Computing Blood Flows

    NASA Technical Reports Server (NTRS)

    Kwak, D.; Chang, J. L. C.; Rogers, S. E.; Rosenfeld, M.

    1990-01-01

    Methods developed for aerospace applied to mechanics of biofluids. Report argues use of advanced computational fluid dynamics to analyze flows of biofluids - especially blood. Ability to simulate numerically and visualize complicated, time-varying three-dimensional flows contributes to understanding of phenomena in heart and blood vessels, offering potential for development of treatments for abnormal flow conditions.

  17. Integer Equal Flows

    SciTech Connect

    Meyers, C A; Schulz, A S

    2009-01-07

    The integer equal flow problem is an NP-hard network flow problem, in which all arcs in given sets R{sub 1}, ..., R{sub {ell}} must carry equal flow. We show this problem is effectively inapproximable, even if the cardinality of each set R{sub k} is two. When {ell} is fixed, it is solvable in polynomial time.

  18. Computing Blood Flows

    NASA Technical Reports Server (NTRS)

    Kwak, D.; Chang, J. L. C.; Rogers, S. E.; Rosenfeld, M.

    1990-01-01

    Methods developed for aerospace applied to mechanics of biofluids. Report argues use of advanced computational fluid dynamics to analyze flows of biofluids - especially blood. Ability to simulate numerically and visualize complicated, time-varying three-dimensional flows contributes to understanding of phenomena in heart and blood vessels, offering potential for development of treatments for abnormal flow conditions.

  19. Flow boiling in vertical down-flow

    SciTech Connect

    Dougherty, T.; Fighetti, C.; Reddy, G.; Yang, B.; Jafri, T.; McAssey, E.; Qureshi, Z.

    1989-12-31

    An experimental program has been conducted to investigate the onset of Ledinegg instability in vertical down-flow. For three size uniformly heated test sections with L/D ratios from 100 to 150, the pressure drop under subcooled boiling conditions has been obtained for a wide range of operating parameters. The results are presented in non-dimensional forms which correlate the important variables and provide techniques for predicting the onset of flow instability. 3 refs.

  20. Flow boiling in vertical down-flow

    SciTech Connect

    Dougherty, T.; Fighetti, C.; Reddy, G.; Yang, B.; Jafri, T. ); McAssey, E. ); Qureshi, Z. )

    1989-01-01

    An experimental program has been conducted to investigate the onset of Ledinegg instability in vertical down-flow. For three size uniformly heated test sections with L/D ratios from 100 to 150, the pressure drop under subcooled boiling conditions has been obtained for a wide range of operating parameters. The results are presented in non-dimensional forms which correlate the important variables and provide techniques for predicting the onset of flow instability. 3 refs.

  1. Flow quality measurements in compressible subsonic flows

    NASA Technical Reports Server (NTRS)

    Stainback, P. Calvin; Johnson, Charles B.

    1987-01-01

    The purpose is to re-examine the heat transfer from a hot-wire probe in the compressible subsonic flow regime; describe the three-wire hot-wire probe calibration and data reduction techniques used to measure the velocity, density, and total temperature fluctuation; and present flow quality results obtained in the Langley 0.3 meter Transonic Cryogenic Wind Tunnel and in flight with the NASA JetStar from the same three-wire hot-wire probe.

  2. Lateral flow strip assay

    DOEpatents

    Miles, Robin R [Danville, CA; Benett, William J [Livermore, CA; Coleman, Matthew A [Oakland, CA; Pearson, Francesca S [Livermore, CA; Nasarabadi, Shanavaz L [Livermore, CA

    2011-03-08

    A lateral flow strip assay apparatus comprising a housing; a lateral flow strip in the housing, the lateral flow strip having a receiving portion; a sample collection unit; and a reagent reservoir. Saliva and/or buccal cells are collected from an individual using the sample collection unit. The sample collection unit is immersed in the reagent reservoir. The tip of the lateral flow strip is immersed in the reservoir and the reagent/sample mixture wicks up into the lateral flow strip to perform the assay.

  3. Low flow fume hood

    DOEpatents

    Bell, Geoffrey C.; Feustel, Helmut E.; Dickerhoff, Darryl J.

    2002-01-01

    A fume hood is provided having an adequate level of safety while reducing the amount of air exhausted from the hood. A displacement flow fume hood works on the principal of a displacement flow which displaces the volume currently present in the hood using a push-pull system. The displacement flow includes a plurality of air supplies which provide fresh air, preferably having laminar flow, to the fume hood. The displacement flow fume hood also includes an air exhaust which pulls air from the work chamber in a minimally turbulent manner. As the displacement flow produces a substantially consistent and minimally turbulent flow in the hood, inconsistent flow patterns associated with contaminant escape from the hood are minimized. The displacement flow fume hood largely reduces the need to exhaust large amounts of air from the hood. It has been shown that exhaust air flow reductions of up to 70% are possible without a decrease in the hood's containment performance. The fume hood also includes a number of structural adaptations which facilitate consistent and minimally turbulent flow within a fume hood.

  4. Technology and new fluorescence flow cytometry parameters in hematological analyzers.

    PubMed

    Arneth, Borros M; Menschikowki, Mario

    2015-05-01

    Modern hematological analyzers offer a series of new tests in addition to the differential blood cell count. Here, we provide a short overview of the technique and the new tests included in the hematological analyzers manufactured by the company Sysmex (Kobe, Japan). As introduced here, the resulting new extended blood cell count allows for the quantification of DNA- and RNA-rich, activated and/or precursor leukocyte subpopulations. To compare the different methods of blood cell counting, repetitive cell counting is carried out by hematological experts using microscopy and using the XE-5000 hematological analyzer. The hematological analyzer delivers more-accurate results with respect to normal cells but microscopy is suited better to recognize and count pathological cells. With the new hematological analyzers, several new hematological tests are made available as screening tools that were not possible previously using standard cell-counting procedures. © 2014 Wiley Periodicals, Inc.

  5. 46 CFR 154.546 - Excess flow valve: Closing flow.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Excess flow valve: Closing flow. 154.546 Section 154.546... and Process Piping Systems § 154.546 Excess flow valve: Closing flow. (a) The rated closing flow of vapor or liquid cargo for an excess flow valve must be specially approved by the Commandant (CG-522)....

  6. Make peak flow a habit!

    MedlinePlus

    Asthma - make peak flow a habit; Reactive airway disease - peak flow; Bronchial asthma - peak flow ... your airways are narrowed and blocked due to asthma, your peak flow values drop. You can check ...

  7. Concentric Split Flow Filter

    NASA Technical Reports Server (NTRS)

    Stapleton, Thomas J. (Inventor)

    2015-01-01

    A concentric split flow filter may be configured to remove odor and/or bacteria from pumped air used to collect urine and fecal waste products. For instance, filter may be designed to effectively fill the volume that was previously considered wasted surrounding the transport tube of a waste management system. The concentric split flow filter may be configured to split the air flow, with substantially half of the air flow to be treated traveling through a first bed of filter media and substantially the other half of the air flow to be treated traveling through the second bed of filter media. This split flow design reduces the air velocity by 50%. In this way, the pressure drop of filter may be reduced by as much as a factor of 4 as compare to the conventional design.

  8. Microparticle Flow Sensor

    NASA Technical Reports Server (NTRS)

    Morrison, Dennis R.

    2005-01-01

    The microparticle flow sensor (MFS) is a system for identifying and counting microscopic particles entrained in a flowing liquid. The MFS includes a transparent, optoelectronically instrumented laminar-flow chamber (see figure) and a computer for processing instrument-readout data. The MFS could be used to count microparticles (including micro-organisms) in diverse applications -- for example, production of microcapsules, treatment of wastewater, pumping of industrial chemicals, and identification of ownership of liquid products.

  9. Polyoxometalate flow battery

    DOEpatents

    Anderson, Travis M.; Pratt, Harry D.

    2016-03-15

    Flow batteries including an electrolyte of a polyoxometalate material are disclosed herein. In a general embodiment, the flow battery includes an electrochemical cell including an anode portion, a cathode portion and a separator disposed between the anode portion and the cathode portion. Each of the anode portion and the cathode portion comprises a polyoxometalate material. The flow battery further includes an anode electrode disposed in the anode portion and a cathode electrode disposed in the cathode portion.

  10. Gas Flow Controller

    NASA Technical Reports Server (NTRS)

    1980-01-01

    The Mass Flowmeter is a device used to measure flow of oxygen in spacecraft's life support system. Tylan Corporation's Mass Flow Controller's major application is accurate control of reactive gases-- such as hydrogen, phosphine and silane as they are diffused at extremely high temperatures into silicon wafers. Wafers are ultimately cut up into integrated circuits or "chips" for electronic products. Precise process control afforded by the Mass Flow Controller makes it possible to produce circuit chips of greater performance at lower cost.

  11. Equivariant mean field flow

    NASA Astrophysics Data System (ADS)

    Castéras, Jean-baptiste

    2013-12-01

    We consider a gradient flow associated to the mean field equation on (M,g), a compact Riemannian surface without boundary. We prove that this flow exists for all time. Moreover, letting G be a group of isometry acting on (M,g), we obtain the convergence of the flow to a solution of the mean field equation under suitable hypothesis on the orbits of points of M under the action of G.

  12. Solids mass flow determination

    DOEpatents

    Macko, Joseph E.

    1981-01-01

    Method and apparatus for determining the mass flow rate of solids mixed with a transport fluid to form a flowing mixture. A temperature differential is established between the solids and fluid. The temperature of the transport fluid prior to mixing, the temperature of the solids prior to mixing, and the equilibrium temperature of the mixture are monitored and correlated in a heat balance with the heat capacities of the solids and fluid to determine the solids mass flow rate.

  13. Excess flow shutoff valve

    DOEpatents

    Kiffer, Micah S.; Tentarelli, Stephen Clyde

    2016-02-09

    Excess flow shutoff valve comprising a valve body, a valve plug, a partition, and an activation component where the valve plug, the partition, and activation component are disposed within the valve body. A suitable flow restriction is provided to create a pressure difference between the upstream end of the valve plug and the downstream end of the valve plug when fluid flows through the valve body. The pressure difference exceeds a target pressure difference needed to activate the activation component when fluid flow through the valve body is higher than a desired rate, and thereby closes the valve.

  14. Multiple sort flow cytometer

    DOEpatents

    Van den Engh, Ger; Esposito, Richard J.

    1996-01-01

    A flow cytometer utilizes multiple lasers for excitation and respective fluorescence of identified dyes bonded to specific cells or events to identify and verify multiple events to be sorted from a sheath flow and droplet stream. Once identified, verified and timed in the sheath flow, each event is independently tagged upon separation from the flow by an electrical charge of +60, +120, or +180 volts and passed through oppositely charged deflection plates with ground planes to yield a focused six way deflection of at least six events in a narrow plane.

  15. Multiple sort flow cytometer

    DOEpatents

    Engh, G. van den; Esposito, R.J.

    1996-01-09

    A flow cytometer utilizes multiple lasers for excitation and respective fluorescence of identified dyes bonded to specific cells or events to identify and verify multiple events to be sorted from a sheath flow and droplet stream. Once identified, verified and timed in the sheath flow, each event is independently tagged upon separation from the flow by an electrical charge of +60, +120, or +180 volts and passed through oppositely charged deflection plates with ground planes to yield a focused six way deflection of at least six events in a narrow plane. 8 figs.

  16. Flows in Stenotic Vessels

    NASA Astrophysics Data System (ADS)

    Berger, S. A.; Jou, L.-D.

    The relationship between flow in the arteries, particularly the wall shear stresses, and the sites where atherosclerosis develops has motivated much of the research on arterial flow in recent decades. It is now well accepted that it is sites where shear stresses are low, or change rapidly in time or space, that are most vulnerable. These conditions are likely to prevail at places where the vessel is curved; bifurcates; has a junction, a side branch, or other sudden change in flow geometry; and when the flow is unsteady. These flows, often but not always involving flow separation or secondary motions, are also the most difficult ones in fluid mechanics to analyze or compute. In this article we review the modeling studies and experiments on steady and unsteady, two-and three-dimensional flows in arteries, and in arterial geometries most relevant in the context of atherosclerosis. These include studies of normal vessels -- to identify, on the basis of the fluid mechanics, lesion foci -- and stenotic vessels, to model and measure flow in vessels after the lesions have evolved into plaques sufficiently large to significantly modify the flow. We also discuss recent work that elucidates many of the pathways by which mechanical forces, primarily the wall shear stresses, are transduced to effect changes in the arterial wall at the cellular, subcellular, and genetic level.

  17. Viscoelastic Squeeze Flow

    NASA Astrophysics Data System (ADS)

    Ashrafi, Nariman; Shafahi, Mehdi

    2016-11-01

    The squeeze flow of a nonlinear viscoelastic flow is studied. In particular the flow of an upper-convected Maxwell fluid between two approaching disks of is analyzed. The momentum and continuity equations together with constitutive relations are solved by a low-order method. Both no slip and slip boundary conditions are considered. Next, stress components are evaluated and flow stability is investigated. It is observed that as the disks approach velocity is increased the developed stresses, which are interrelated to velocity gradients through the constitutive relation, are altered exponentially. This analysis is applicable to many industrial instances of such as lubrication as well as natural joints. nariman ashrafi.

  18. Flowing in, Flowing out of Aelia

    NASA Image and Video Library

    2013-12-16

    This colorful composite image from NASA Dawn mission shows the flow of material inside and outside a crater called Aelia on the giant asteroid Vesta. To the naked eye, these structures would not be seen. But here, they stand out in blue and red.

  19. Elbow mass flow meter

    DOEpatents

    McFarland, A.R.; Rodgers, J.C.; Ortiz, C.A.; Nelson, D.C.

    1994-08-16

    The present invention includes a combination of an elbow pressure drop generator and a shunt-type mass flow sensor for providing an output which gives the mass flow rate of a gas that is nearly independent of the density of the gas. For air, the output is also approximately independent of humidity. 3 figs.

  20. Flow Interactions and Control

    DTIC Science & Technology

    2013-03-04

    0 0.1 0.2 0.3 F H T A T H F H average duration of active turbulence fraction of time taken by hibernation Onset of DR average duration of... hibernation Laminar flow Turbulent flow Upper branch ECS Low-drag excursions- hibernation Turbulent bursts Basin boundary: • lower-branch

  1. Turbulence in Compressible Flows

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Lecture notes for the AGARD Fluid Dynamics Panel (FDP) Special Course on 'Turbulence in Compressible Flows' have been assembled in this report. The following topics were covered: Compressible Turbulent Boundary Layers, Compressible Turbulent Free Shear Layers, Turbulent Combustion, DNS/LES and RANS Simulations of Compressible Turbulent Flows, and Case Studies of Applications of Turbulence Models in Aerospace.

  2. Microelectromechanical flow control apparatus

    DOEpatents

    Okandan, Murat [NE Albuquerque, NM

    2009-06-02

    A microelectromechanical (MEM) flow control apparatus is disclosed which includes a fluid channel formed on a substrate from a first layer of a nonconducting material (e.g. silicon nitride). A first electrode is provided on the first layer of the nonconducting material outside the flow channel; and a second electrode is located on a second layer of the nonconducting material above the first layer. A voltage applied between the first and second electrodes deforms the fluid channel to increase its cross-sectional size and thereby increase a flow of a fluid through the channel. In certain embodiments of the present invention, the fluid flow can be decreased or stopped by applying a voltage between the first electrode and the substrate. A peristaltic pumping of the fluid through the channel is also possible when the voltage is applied in turn between a plurality of first electrodes and the substrate. A MEM flow control assembly can also be formed by providing one or more MEM flow control devices on a common substrate together with a submicron filter. The MEM flow control assembly can optionally include a plurality of pressure sensors for monitoring fluid pressure and determining flow rates through the assembly.

  3. Flow cytometry of sperm

    SciTech Connect

    Gledhill, B.L.

    1987-09-21

    This brief paper summarizes automated flow cytometric determination of sperm morphology and flow cytometry/sorting of sperm with application to sex preselection. In the latter context, mention is made of results of karyotypic determination of sex chromosome ratios in albumin-processed human sperm. 23 refs., 1 fig., 1 tab.

  4. Growing with the Flows

    ERIC Educational Resources Information Center

    Durkin, Dorothy

    2010-01-01

    People live and work in an era of transformation and uncertainty; they know that things are changing, but they are not sure where they are headed. One of the key forces of change is the enormous flow of information that individuals and institutions consume and produce. Awareness of knowledge flow is essential, but so is the sense that neither…

  5. Hanford basalt flow mineralogy

    SciTech Connect

    Ames, L.L.

    1980-09-01

    Mineralogy of the core samples from five core wells was examined in some detail. The primary mineralogy study included an optical examination of polished mounts, photomicrographs, chemical analyses of feldspars, pyroxenes, metallic oxides and microcrystalline groundmasses and determination from the chemical analyses of the varieties of feldspars, pyroxenes and metallic oxides. From the primary mineralogy data, a firm understanding of the average Hanford basalt flow primary mineralogy emerged. The average primary feldspar was a laboradorite, the average pyroxene was an augite and the average metallic oxide was a solid solution of ilmenite and magnetite. Secondary mineralization consisted of vug filling and joint coating, chiefly with a nontronite-beidellite clay, several zeolites, quartz, calcite, and opal. Specific flow units also were examined to determine the possibility of using the mineralogy to trace flows between core wells. These included units of the Pomona, the Umatilla and a high chromium flow just below the Huntzinger. In the Umatilla, or high barium flow, the compositional variation of the feldspars was unique in range. The pyroxenes in the Pomona were relatively highly zoned and accumulated chromium. The high chromium flow contained chromium spinels that graded in chromium content into simple magnetites very low in chromium content. A study of the statistical relationships of flow unit chemical constituents showed that flow unit constituents could be roughly correlated between wells. The probable cause of the correlation was on-going physical-chemical changes in the source magma.

  6. Elliptic Flow Fluctuations

    NASA Astrophysics Data System (ADS)

    Mrowczynski, Stanislaw; Shuryak, Edward V.

    2003-08-01

    We suggest to perform systematic measurements of the elliptic flow fluctuations which are sensitive to the early stage dynamics of heavy-ion collisions at high-energies. Significant flow fluctuations are shown to be generated due to the formation of topological clusters and development of the filamentation instability. The statistical noise and hydrodynamic fluctuations are also estimated.

  7. Stochastic Flows in Networks.

    DTIC Science & Technology

    1987-12-01

    Telecomunications Networks This work appeared in: ., Serfozo, R.f. (1986). Equitable transit charges for multi-administration ? telecommunications...solved an analogous problem for a single server that can serve one of several separate flows of customers; the question being which flow should the

  8. Lava Flow Dynamics

    NASA Technical Reports Server (NTRS)

    Taylor, G. Jeffrey

    1996-01-01

    This grant originally had four major tasks, all of which were addressed to varying extents during the course of the research: (1) Measure the fractal dimensions of lava flows as a function of topography, substrate, and rheology; (2) The nature of lava tube systems and their relation to flow fields; (3) A quantitative assessment of lava flow dynamics in light of the fractal nature of lava flow margins; and (4) Development and application of a new remote sensing tool based on fractal properties. During the course of the research, the project expanded to include the following projects: (1) A comparison of what we can-learn from remote sensing studies of lava flow morphology and from studies of samples of lava flows; (2) Study of a terrestrial analog of the nakhlites, one of the groups of meteorites from Mars; and (3) Study of the textures of Hawaiian basalts as an aid in understanding the dynamics (flow rates, inflation rates, thermal history) of flow interiors. In addition, during the first year an educational task (development and writing of a teacher's guide and activity set to accompany the lunar sample disk when it is sent to schools) was included.

  9. Turbulence in Compressible Flows

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Lecture notes for the AGARD Fluid Dynamics Panel (FDP) Special Course on 'Turbulence in Compressible Flows' have been assembled in this report. The following topics were covered: Compressible Turbulent Boundary Layers, Compressible Turbulent Free Shear Layers, Turbulent Combustion, DNS/LES and RANS Simulations of Compressible Turbulent Flows, and Case Studies of Applications of Turbulence Models in Aerospace.

  10. AUTO-EXPANSIVE FLOW

    EPA Science Inventory

    Physics suggests that the interplay of momentum, continuity, and geometry in outward radial flow must produce density and concomitant pressure reductions. In other words, this flow is intrinsically auto-expansive. It has been proposed that this process is the key to understanding...

  11. Field-Flow Fractionation.

    ERIC Educational Resources Information Center

    Caldwell, Karin D.

    1988-01-01

    Describes a technique for separating samples that range over 15 orders of magnitude in molecular weight. Discusses theory, apparatus, and sample preparation techniques. Lists several types of field-flow fractionation (FFF) and their uses: sedimentation FFF, thermal FFF, flow FFF, electrical FFF, and steric FFF. (ML)

  12. AUTO-EXPANSIVE FLOW

    EPA Science Inventory

    Physics suggests that the interplay of momentum, continuity, and geometry in outward radial flow must produce density and concomitant pressure reductions. In other words, this flow is intrinsically auto-expansive. It has been proposed that this process is the key to understanding...

  13. Flow compensating pressure regulator

    NASA Technical Reports Server (NTRS)

    Baehr, E. F. (Inventor)

    1978-01-01

    An apparatus for regulating pressure of treatment fluid during ophthalmic procedures is described. Flow sensing and pressure regulating diaphragms are used to modulate a flow control valve. The pressure regulating diaphragm is connected to the flow control valve to urge the valve to an open position due to pressure being applied to the diaphragm by bias means such as a spring. The flow sensing diaphragm is mechanically connected to the flow control valve and urges it to an opened position because of the differential pressure on the diaphragm generated by a flow of incoming treatment fluid through an orifice in the diaphragm. A bypass connection with a variable restriction is connected in parallel relationship to the orifice to provide for adjusting the sensitivity of the flow sensing diaphragm. A multiple lever linkage system is utilized between the center of the second diaphragm and the flow control valve to multiply the force applied to the valve by the other diaphragm and reverse the direction of the force.

  14. Facilitating Naval Knowledge Flow

    DTIC Science & Technology

    2001-07-01

    Transition ...................................................................... 9 Figure 5 Nonaka Knowledge Flow Theory...terms of the dimension reach above. Episteoloogical Explicit Tackt Individual Group Organizabori loter-organization Ontological Figure 5 Nonaka ... Knowledge Flow Theory (Adapted from [48]) As depicted in Figure 5, Nonaka views the interaction between these dimensions as the principal drivers of

  15. RG flows and bifurcations

    NASA Astrophysics Data System (ADS)

    Gukov, Sergei

    2017-06-01

    Interpreting RG flows as dynamical systems in the space of couplings we produce a variety of constraints, global (topological) as well as local. These constraints, in turn, rule out some of the proposed RG flows and also predict new phases and fixed points, surprisingly, even in familiar theories such as O (N) model, QED3, or QCD4.

  16. Flow Around Steep Topography

    DTIC Science & Technology

    2015-09-30

    Flow around steep topography T. M. Shaun Johnston Scripps Institution of Oceanography University of California, San Diego 9500 Gilman Drive, M...tall, steep, submarine topography and islands. During the Flow Encountering Abrupt Topography (FLEAT) DRI, investigators will determine: • Whether...estimates from making accurate statistical/deterministic predictions at ᝺ km resolution around submarine topography and islands? How can we

  17. Base Flow Model Validation

    NASA Technical Reports Server (NTRS)

    Sinha, Neeraj; Brinckman, Kevin; Jansen, Bernard; Seiner, John

    2011-01-01

    A method was developed of obtaining propulsive base flow data in both hot and cold jet environments, at Mach numbers and altitude of relevance to NASA launcher designs. The base flow data was used to perform computational fluid dynamics (CFD) turbulence model assessments of base flow predictive capabilities in order to provide increased confidence in base thermal and pressure load predictions obtained from computational modeling efforts. Predictive CFD analyses were used in the design of the experiments, available propulsive models were used to reduce program costs and increase success, and a wind tunnel facility was used. The data obtained allowed assessment of CFD/turbulence models in a complex flow environment, working within a building-block procedure to validation, where cold, non-reacting test data was first used for validation, followed by more complex reacting base flow validation.

  18. Flows around bacterial swarms

    NASA Astrophysics Data System (ADS)

    Dauparas, Justas; Lauga, Eric

    2015-11-01

    Flagellated bacteria on nutrient-rich substrates can differentiate into a swarming state and move in dense swarms across surfaces. A recent experiment (HC Berg, Harvard University) measured the flow in the fluid around the swarm. A systematic chiral flow was observed in the clockwise direction (when viewed from above) ahead of a E.coli swarm with flow speeds of about 10 μm/s, about 3 times greater than the radial velocity at the edge of the swarm. The working hypothesis is that this flow is due to the flagella of cells stalled at the edge of a colony which extend their flagellar filaments outwards, moving fluid over the virgin agar. In this talk we quantitatively test his hypothesis. We first build an analytical model of the flow induced by a single flagellum in a thin film and then use the model, and its extension to multiple flagella, to compare with experimental measurements.

  19. Lasers in flow cytometry.

    PubMed

    Telford, William G

    2011-01-01

    Laser technology has advanced tremendously since the first gas lasers were incorporated into early flow cytometers. Gas lasers have been largely replaced by solid-state laser technology, making virtually any desirable visible light wavelength available for flow cytometry. Multiwavelength, white light, and wavelength tunable lasers are poised to enhance our analytical capabilities even further. In this chapter, I summarize the role that lasers play in cytometry, and the practical characteristics that make a laser appropriate for flow cytometry. I then review the latest single wavelength lasers available for flow cytometry, and how they can be used to excite the ever-expanding array of available fluorochromes. Finally, I review the contribution and potential of the latest tunable laser technology to flow cytometry, and show several examples of these novel sources integrated into production instruments. Technical details and critical parameters for successful application of these lasers for biomedical analysis are covered in depth.

  20. Data flow modeling techniques

    NASA Technical Reports Server (NTRS)

    Kavi, K. M.

    1984-01-01

    There have been a number of simulation packages developed for the purpose of designing, testing and validating computer systems, digital systems and software systems. Complex analytical tools based on Markov and semi-Markov processes have been designed to estimate the reliability and performance of simulated systems. Petri nets have received wide acceptance for modeling complex and highly parallel computers. In this research data flow models for computer systems are investigated. Data flow models can be used to simulate both software and hardware in a uniform manner. Data flow simulation techniques provide the computer systems designer with a CAD environment which enables highly parallel complex systems to be defined, evaluated at all levels and finally implemented in either hardware or software. Inherent in data flow concept is the hierarchical handling of complex systems. In this paper we will describe how data flow can be used to model computer system.

  1. Vortex flow hysteresis

    NASA Technical Reports Server (NTRS)

    Cunningham, A. M., Jr.

    1986-01-01

    An experimental study was conducted to quantify the hysteresis associated with various vortex flow transition points and to determine the effect of planform geometry. The transition points observed consisted of the appearance (or disappearance) of trailing edge vortex burst and the transition to (or from) flat plate or totally separated flows. Flow visualization with smoke injected into the vortices was used to identify the transitions on a series of semi-span models tested in a low speed tunnel. The planforms tested included simple deltas (55 deg to 80 deg sweep), cranked wings with varying tip panel sweep and dihedral, and a straked wing. High speed movies at 1000 frames per second were made of the vortex flow visualization in order to better understand the dynamics of vortex flow, burst and transition.

  2. Flow in bedrock canyons.

    PubMed

    Venditti, Jeremy G; Rennie, Colin D; Bomhof, James; Bradley, Ryan W; Little, Malcolm; Church, Michael

    2014-09-25

    Bedrock erosion in rivers sets the pace of landscape evolution, influences the evolution of orogens and determines the size, shape and relief of mountains. A variety of models link fluid flow and sediment transport processes to bedrock incision in canyons. The model components that represent sediment transport processes are increasingly well developed. In contrast, the model components being used to represent fluid flow are largely untested because there are no observations of the flow structure in bedrock canyons. Here we present a 524-kilometre, continuous centreline, acoustic Doppler current profiler survey of the Fraser Canyon in western Canada, which includes 42 individual bedrock canyons. Our observations of three-dimensional flow structure reveal that, as water enters the canyons, a high-velocity core follows the bed surface, causing a velocity inversion (high velocities near the bed and low velocities at the surface). The plunging water then upwells along the canyon walls, resulting in counter-rotating, along-stream coherent flow structures that diverge near the bed. The resulting flow structure promotes deep scour in the bedrock channel floor and undercutting of the canyon walls. This provides a mechanism for channel widening and ensures that the base of the walls is swept clear of the debris that is often deposited there, keeping the walls nearly vertical. These observations reveal that the flow structure in bedrock canyons is more complex than assumed in the models presently used. Fluid flow models that capture the essence of the three-dimensional flow field, using simple phenomenological rules that are computationally tractable, are required to capture the dynamic coupling between flow, bedrock erosion and solid-Earth dynamics.

  3. 46 CFR 154.546 - Excess flow valve: Closing flow.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 5 2012-10-01 2012-10-01 false Excess flow valve: Closing flow. 154.546 Section 154.546 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SAFETY... and Process Piping Systems § 154.546 Excess flow valve: Closing flow. (a) The rated closing flow of...

  4. 46 CFR 154.546 - Excess flow valve: Closing flow.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false Excess flow valve: Closing flow. 154.546 Section 154.546 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SAFETY... and Process Piping Systems § 154.546 Excess flow valve: Closing flow. (a) The rated closing flow of...

  5. 46 CFR 154.546 - Excess flow valve: Closing flow.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 5 2014-10-01 2014-10-01 false Excess flow valve: Closing flow. 154.546 Section 154.546 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SAFETY... and Process Piping Systems § 154.546 Excess flow valve: Closing flow. (a) The rated closing flow of...

  6. 46 CFR 154.546 - Excess flow valve: Closing flow.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 5 2013-10-01 2013-10-01 false Excess flow valve: Closing flow. 154.546 Section 154.546 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SAFETY... and Process Piping Systems § 154.546 Excess flow valve: Closing flow. (a) The rated closing flow of...

  7. Gas Flow Detection System

    NASA Technical Reports Server (NTRS)

    Moss, Thomas; Ihlefeld, Curtis; Slack, Barry

    2010-01-01

    This system provides a portable means to detect gas flow through a thin-walled tube without breaking into the tubing system. The flow detection system was specifically designed to detect flow through two parallel branches of a manifold with only one inlet and outlet, and is a means for verifying a space shuttle program requirement that saves time and reduces the risk of flight hardware damage compared to the current means of requirement verification. The prototype Purge Vent and Drain Window Cavity Conditioning System (PVD WCCS) Flow Detection System consists of a heater and a temperature-sensing thermistor attached to a piece of Velcro to be attached to each branch of a WCCS manifold for the duration of the requirement verification test. The heaters and thermistors are connected to a shielded cable and then to an electronics enclosure, which contains the power supplies, relays, and circuit board to provide power, signal conditioning, and control. The electronics enclosure is then connected to a commercial data acquisition box to provide analog to digital conversion as well as digital control. This data acquisition box is then connected to a commercial laptop running a custom application created using National Instruments LabVIEW. The operation of the PVD WCCS Flow Detection System consists of first attaching a heater/thermistor assembly to each of the two branches of one manifold while there is no flow through the manifold. Next, the software application running on the laptop is used to turn on the heaters and to monitor the manifold branch temperatures. When the system has reached thermal equilibrium, the software application s graphical user interface (GUI) will indicate that the branch temperatures are stable. The operator can then physically open the flow control valve to initiate the test flow of gaseous nitrogen (GN2) through the manifold. Next, the software user interface will be monitored for stable temperature indications when the system is again at

  8. AFE base flow computations

    NASA Technical Reports Server (NTRS)

    Venkatapathy, Ethiraj; Prabhu, Dinesh K.; Palmer, Grant

    1991-01-01

    Hypersonic wake flows behind the Aeroassist Flight Experiment (AFE) geometry are analyzed using two Navier-Stokes flow solvers. Many of the AFE wake features observed in ballistic-range shadowgraphs are simulated using a simple, two-dimensional semicylinder geometry at moderate angles of attack. At free-stream conditions corresponding to a Hypersonic Free Flight Facility (HFFF) AFE experiment, the three-dimensional base flow for the AFE geometry is computed using an ideal-gas, Navier-Stokes solver. The computed results agree reasonably well with the shadowgraphs taken at the HFFF. An ideal-gas and a nonequilibrium Navier-Stokes solver have been coupled and applied to the complete flow around the AFE vehicle at the free-stream conditions corresponding to a nomial trajectory point. Limitations of the coupled ideal-gas and nonequilibrium solution are discussed. The nonequilibrium base flow solution is analyzed for the wake radiation and the radiation profiles along various lines of sight are compared. Finally, the wake unsteadiness is predicted using experimental correlations and the numerical solutions. An adaptive grid code, SAGE, has been used in all the simulations to enhance the solution accuracy. The grid adaptation is found to be necessary in obtaining base flow solutions with accurate flow features.

  9. Flow-duration curves

    USGS Publications Warehouse

    Searcy, James Kincheon

    1959-01-01

    The flow-duration curve is a cumulative frequency curve that shows the percent of time specified discharges were equaled or exceeded during a given period. It combines in one curve the flow characteristics of a stream throughout the range of discharge, without regard to the sequence of occurrence. If the period upon which the curve is based represents the long-term flow of a stream, the curve may be used to predict the distribution of future flows for water- power, water-supply, and pollution studies. This report shows that differences in geology affect the low-flow ends of flow-duration curves of streams in adjacent basins. Thus, duration curves are useful in appraising the geologic characteristics of drainage basins. A method for adjusting flow-duration curves of short periods to represent long-term conditions is presented. The adjustment is made by correlating the records of a short-term station with those of a long-term station.

  10. Counting RG flows

    DOE PAGES

    Gukov, Sergei

    2016-01-05

    Here, interpreting renormalization group flows as solitons interpolating between different fixed points, we ask various questions that are normally asked in soliton physics but not in renormalization theory. Can one count RG flows? Are there different "topological sectors" for RG flows? What is the moduli space of an RG flow, and how does it compare to familiar moduli spaces of (supersymmetric) dowain walls? Analyzing these questions in a wide variety of contexts -- from counting RG walls to AdS/CFT correspondence -- will not only provide favorable answers, but will also lead us to a unified general framework that is powerfulmore » enough to account for peculiar RG flows and predict new physical phenomena. Namely, using Bott's version of Morse theory we relate the topology of conformal manifolds to certain properties of RG flows that can be used as precise diagnostics and "topological obstructions" for the strong form of the C-theorem in any dimension. Moreover, this framework suggests a precise mechanism for how the violation of the strong C-theorem happens and predicts "phase transitions" along the RG flow when the topological obstruction is non-trivial. Along the way, we also find new conformal manifolds in well-known 4d CFT's and point out connections with the superconformal index and classifying spaces of global symmetry groups.« less

  11. Natural flow wing

    NASA Technical Reports Server (NTRS)

    Wood, Richard M. (Inventor); Bauer, Steven X. S. (Inventor)

    1992-01-01

    The invention is a natural flow wing and a method for constructing the same. The method comprises contouring a three-dimensional upper surface and a three-dimensional lower surface of the natural flow wing independently of one another into a prescribed shape. Experimental data and theoretical analysis show that flow and pressure-loading over an upper surface of a wing tend to be conical about an apex of the wing, producing favorable and unfavorable regions of performance based on drag. The method reduces these unfavorable regions by shaping the upper surface such that the maximum thickness near a tip of the natural flow wing moves aft, thereby, contouring the wing to coincide more closely with the conical nature of the flow on the upper surface. Nearly constant compressive loading characterizes the flow field over a lower surface of the conventional wing. Magnitude of these compressive pressures on the lower surface depends on angle of attack and on a streamwise curvature of the lower surface of the wing and not on a cross-sectional spanwise curvature. The method, thereby, shapes the lower surface to create an area as large as possible with negative slopes. Any type of swept wing may be used to obtain the final, shaped geometry of the upper and lower surfaces of the natural flow wing.

  12. Counting RG flows

    SciTech Connect

    Gukov, Sergei

    2016-01-05

    Here, interpreting renormalization group flows as solitons interpolating between different fixed points, we ask various questions that are normally asked in soliton physics but not in renormalization theory. Can one count RG flows? Are there different "topological sectors" for RG flows? What is the moduli space of an RG flow, and how does it compare to familiar moduli spaces of (supersymmetric) dowain walls? Analyzing these questions in a wide variety of contexts -- from counting RG walls to AdS/CFT correspondence -- will not only provide favorable answers, but will also lead us to a unified general framework that is powerful enough to account for peculiar RG flows and predict new physical phenomena. Namely, using Bott's version of Morse theory we relate the topology of conformal manifolds to certain properties of RG flows that can be used as precise diagnostics and "topological obstructions" for the strong form of the C-theorem in any dimension. Moreover, this framework suggests a precise mechanism for how the violation of the strong C-theorem happens and predicts "phase transitions" along the RG flow when the topological obstruction is non-trivial. Along the way, we also find new conformal manifolds in well-known 4d CFT's and point out connections with the superconformal index and classifying spaces of global symmetry groups.

  13. Flow cytometric analysis of platelet cyclooxygenase-1 and -2 and surface glycoproteins in patients with immune thrombocytopenia and healthy individuals.

    PubMed

    Rubak, Peter; Kristensen, Steen D; Hvas, Anne-Mette

    2017-06-01

    Immature platelets may contain more platelet enzymes such as cyclooxygenase (COX)-1 and COX-2 than mature platelets. Patients with immune thrombocytopenia (ITP) have a higher fraction of immature platelets and can therefore be utilized as a biological model for investigating COX-1 and COX-2 platelet expression. The aims were to develop flow cytometric assays for platelet COX-1 and COX-2 and to investigate the COX-1 and COX-2 platelet expression, platelet turnover, and platelet glycoproteins in ITP patients (n = 10) compared with healthy individuals (n = 30). Platelet count and platelet turnover parameters (mean platelet volume (MPV), immature platelet fraction (IPF), and immature platelet count (IPC)) were measured by flow cytometry (Sysmex XE-5000). Platelet COX-1, COX-2, and the glycoproteins (GP)IIb, IX, Ib, Ia, and IIIa were all analyzed by flow cytometry (Navios) and expressed as median fluorescence intensity. COX analyses were performed in both whole blood and platelet rich plasma (PRP), whereas platelet glycoproteins were analyzed in whole blood only. ITP patients had significantly lower platelet count (55 × 10(9)/L) than healthy individuals (240 × 10(9)/L, p < 0.01), but a higher MPV (p = 0.03) and IPF (p < 0.01). IPC was similar for the two groups (p = 0.74). PRP had significantly lower MPV (p < 0.01) and significantly higher platelet count and IPC (both p-values <0.03) when compared with whole blood. IPF was similar for PRP and whole blood (p = 0.18). COX-1 expression was 10 times higher and COX-2 expression was 50% higher in PRP than in whole blood (pCOX-1 < 0.01, pCOX-2 < 0.01). Platelet COX-1 expression was higher in ITP patients than healthy individuals using whole blood (pCOX-1 < 0.01) and PRP, though this was nonsignificant in PRP (pCOX-1 = 0.17). In ITP patients, positive correlations were found between platelet turnover and COX-1 expression (all p-values <0.01, rho = 0.80-0.94), whereas healthy individuals showed significant though weaker

  14. Numerical calculations of flow fields

    NASA Technical Reports Server (NTRS)

    Anderson, D.; Vogel, J. M.

    1973-01-01

    Numerical calculations were made of flow fields generated by various aerodynamic configurations. Data cover flow fields generated by a finitely thick lifting three dimensional wing with subsonic tips moving at supersonic speeds, cross flow instability associated with lifting delta wing configurations such as space shuttles, and flow fields produced by a lifting elliptic cone. Finite difference techniques were used to determine elliptic cone flow.

  15. Shroud leakage flow discouragers

    DOEpatents

    Bailey, Jeremy Clyde; Bunker, Ronald Scott

    2002-01-01

    A turbine assembly includes a plurality of rotor blades comprising a root portion, an airfoil having a pressure sidewall and a suction sidewall, and a top portion having a cap. An outer shroud is concentrically disposed about said rotor blades, said shroud in combination with said tip portions defining a clearance gap. At least one circumferential shroud leakage discourager is disposed within the shroud. The leakage discourager(s) increase the flow resistance and thus reduce the flow of hot gas flow leakage for a given pressure differential across the clearance gap to improve overall turbine efficiency.

  16. Flow-induced vibration

    SciTech Connect

    Blevins, R.D.

    1990-01-01

    This book reports on dimensional analysis; ideal fluid models; vortex-induced vibration; galloping and flutter; instability of tube and cylinder arrays; vibrations induced by oscillating flow; vibration induced by turbulence and sound; damping of structures; sound induced by vortex shedding; vibrations of a pipe containing a fluid flow; indices. It covers the analysis of the vibrations of structures exposed to fluid flows; explores applications for offshore platforms and piping; wind-induced vibration of buildings, bridges, and towers; and acoustic and mechanical vibration of heat exchangers, power lines, and process ducting.

  17. Tank depletion flow controller

    DOEpatents

    Georgeson, Melvin A.

    1976-10-26

    A flow control system includes two bubbler tubes installed at different levels within a tank containing such as radioactive liquid. As the tank is depleted, a differential pressure transmitter monitors pressure differences imparted by the two bubbler tubes at a remote, shielded location during uniform time intervals. At the end of each uniform interval, balance pots containing a dense liquid are valved together to equalize the pressures. The resulting sawtooth-shaped signal generated by the differential pressure transmitter is compared with a second sawtooth signal representing the desired flow rate during each time interval. Variations in the two signals are employed by a control instrument to regulate flow rate.

  18. Geophysical fluid flow experiment

    NASA Technical Reports Server (NTRS)

    Broome, B. G.; Fichtl, G.; Fowlis, W.

    1979-01-01

    The essential fluid flow processes associated with the solar and Jovian atmospheres will be examined in a laboratory experiment scheduled for performance on Spacelab Missions One and Three. The experimental instrumentation required to generate and to record convective fluid flow is described. Details of the optical system configuration, the lens design, and the optical coatings are described. Measurement of thermal gradient fields by schlieren techniques and measurement of fluid flow velocity fields by photochromic dye tracers is achieved with a common optical system which utilizes photographic film for data recording. Generation of the photochromic dye tracers is described, and data annotation of experimental parameters on the film record is discussed.

  19. Aircraft Laminar Flow Control

    NASA Technical Reports Server (NTRS)

    Joslin, Ronald D.

    1998-01-01

    Aircraft laminar flow control (LFC) from the 1930's through the 1990's is reviewed and the current status of the technology is assessed. Examples are provided to demonstrate the benefits of LFC for subsonic and supersonic aircraft. Early studies related to the laminar boundary-layer flow physics, manufacturing tolerances for laminar flow, and insect-contamination avoidance are discussed. LFC concept studies in wind-tunnel and flight experiments are the major focus of the paper. LFC design tools are briefly outlined for completeness.

  20. Bypass Flow Study

    SciTech Connect

    Richard Schultz

    2011-09-01

    The purpose of the fluid dynamics experiments in the MIR (Matched Index of-Refraction) flow system at Idaho National Laboratory (INL) is to develop benchmark databases for the assessment of Computational Fluid Dynamics (CFD) solutions of the momentum equations, scalar mixing, and turbulence models for the flow ratios between coolant channels and bypass gaps in the interstitial regions of typical prismatic standard fuel element (SFE) or upper reflector block geometries of typical Modular High-temperature Gas-cooled Reactors (MHTGR) in the limiting case of negligible buoyancy and constant fluid properties. The experiments use Particle Image Velocimetry (PIV) to measure the velocity fields that will populate the bypass flow study database.

  1. Vesicles in Poiseuille flow.

    PubMed

    Danker, Gerrit; Vlahovska, Petia M; Misbah, Chaouqi

    2009-04-10

    Blood microcirculation critically depends on the migration of red cells towards the flow centerline. We identify theoretically the ratio of the inner over the outer fluid viscosities lambda as a key parameter. At low lambda, the vesicle deforms into a tank-treading ellipsoid shape far away from the flow centerline. The migration is always towards the flow centerline, unlike drops. Above a critical lambda, the vesicle tumbles or breaths and migration is suppressed. A surprising coexistence of two types of shapes at the centerline, a bulletlike and a parachutelike shape, is predicted.

  2. Pulsatile prosthetic valve flows.

    PubMed

    Phillips, W M; Snyder, A; Alchas, P; Rosenberg, G; Pierce, W S

    1980-01-01

    The laser Doppler system has been established as a useful tool for eliciting the properties of simulated cardiovascular flows, and thus for comparative studies of flow properties of prosthetic valves. Significant differences among valve types and between models of one type have been documented. The complex variations of velocity profiles with time show that comparisons must be made for unsteady pulsatile rather than steady flow, despite the volume and complexity of the data required. Future studies will include methods of compacting the data presentation and improving the details of the experimental stimulation.

  3. Marangoni flow revisited.

    PubMed

    Tadmor, Rafael

    2009-04-15

    A view of the Marangoni effect from the perspectives of all three possible interfaces as motion inducing agents is given. Arguments are made that it is required and sufficient that surface tension gradient at the substrate surface induce the flow while the liquid vapor surface tension gradient is unable to induce a flow on its own; that the flow is toward a lower interface potential at the wall liquid interface; and that this is an appropriate way of viewing the Marangoni effect is demonstrated with examples.

  4. Initiation of slug flow

    SciTech Connect

    Hanratty, T.J.; Woods, B.D.

    1995-12-31

    The initiation of slug flow in a horizontal pipe can be predicted either by considering the stability of a slug or by considering the stability of a stratified flow. Measurements of the shedding rate of slugs are used to define necessary conditions for the existence of a slug. Recent results show that slugs develop from an unstable stratified flow through the evolution of small wavelength waves into large wavelength waves that have the possibility of growing to form a slug. The mechanism appears to be quite different for fluids with viscosities close to water than for fluids with large viscosities (20 centipoise).

  5. Flow Resistivity Instrument

    NASA Technical Reports Server (NTRS)

    Zuckerwar, A. J. (Inventor)

    1983-01-01

    A method and apparatus for making in-situ measurements of flow resistivity on the Earth's ground surface is summarized. The novel feature of the invention is two concentric cylinders, inserted into the ground surface with a measured pressure applied to the surface inside the inner cylinder. The outer cylinder vents a plane beneath the surface to the atmosphere through an air space. The flow to the inner cylinder is measured thereby indicating the flow from the surface to the plane beneath the surface.

  6. Flow visualization in long neck Helmholtz resonators with grazing flow

    NASA Technical Reports Server (NTRS)

    Baumeister, K. J.; Rice, E. J.

    1976-01-01

    Both oscillating and steady flows were applied to a single plexiglass resonator cavity with colored dyes injected in both the orifice and grazing flow field to record the motion of the fluid. For oscillatory flow, the instantaneous dye streamlines were similar for both the short and long-neck orifices. The orifice flow blockage appears to be independent of orifice length for a fixed amplitude of flow oscillation and magnitude of the grazing flow. The steady flow dye studies showed that the acoustic and steady flow resistances do not necessarily correspond for long neck orifices.

  7. Low pressure stagnation flow reactor with a flow barrier

    DOEpatents

    Vosen, Steven R.

    2001-01-01

    A flow barrier disposed at the periphery of a workpiece for achieving uniform reaction across the surface of the workpiece, such as a semiconductor wafer, in a stagnation flow reactor operating under the conditions of a low pressure or low flow rate. The flow barrier is preferably in the shape of annulus and can include within the annular structure passages or flow channels for directing a secondary flow of gas substantially at the surface of a semiconductor workpiece. The flow barrier can be constructed of any material which is chemically inert to reactive gases flowing over the surface of the semiconductor workpiece.

  8. Zonal flow generation in parallel flow shear driven turbulence

    NASA Astrophysics Data System (ADS)

    Kosuga, Y.; Itoh, S.-I.; Itoh, K.

    2017-03-01

    Generation of zonal flow in parallel flow shear driven turbulence is discussed. Nonlinear dynamics is formulated by calculating energy transfer in the wave number space. It is shown that zonal flows can be generated (gain energy) from the primary mode which is driven by parallel flow shear. As a result, helical flow pattern can develop in turbulent plasmas. Our results imply that zonal flow can be generated in 3D parallel flow shear driven turbulence, which indicates that zonal flows are ubiquitous in turbulent plasmas, either 2D or 3D. Implications for turbulent momentum transport in laboratory and astrophysical plasmas are discussed.

  9. Parallel flow diffusion battery

    DOEpatents

    Yeh, Hsu-Chi; Cheng, Yung-Sung

    1984-08-07

    A parallel flow diffusion battery for determining the mass distribution of an aerosol has a plurality of diffusion cells mounted in parallel to an aerosol stream, each diffusion cell including a stack of mesh wire screens of different density.

  10. Sulphur flows on Io

    NASA Technical Reports Server (NTRS)

    Sagan, C.

    1979-01-01

    Flows of liquid sulfur are discussed as the sources of the variegated color patterns observed on Io. The variation of the viscosity of liquid sulfur as it cools from black to red to orange to yellow are shown to explain the black and red-black colors of the calderas, where molten sulfur reaches the surface, the red sinuous deposits presumably formed by high-viscosity laminar flows, and the yellow and orange-yellow plains, a product of rapid, turbulent flows. The sulfur allotropes responsible for these colors are preserved in the rapid quenching of molten sulfur, with a characteristic decay time under Ionian conditions estimated to be greater than the lifetime of Io. Observations of an atmospheric pressure of 10 to the -6th bar indicate that only a small fraction of Io is molten at any one time, however the entire surface is renewed in color and albedo by sulfur flows every thousand years.

  11. Parallel flow diffusion battery

    DOEpatents

    Yeh, H.C.; Cheng, Y.S.

    1984-01-01

    A parallel flow diffusion battery for determining the mass distribution of an aerosol has a plurality of diffusion cells mounted in parallel to an aerosol stream, each diffusion cell including a stack of mesh wire screens of different density.

  12. Cryogenic Flows on Ceres

    NASA Astrophysics Data System (ADS)

    Krohn, K.; Jaumann, R.; Otto, K. A.; von der Gahten, I.; Matz, K.-D.; Buczkowski, D. L.; Williams, D. A.; Pieters, C. M.; Preusker, F.; Roatsch, T.; Stephan, K.; Wagner, R. J.; Russell, C. T.; Raymond, C. A.

    2016-08-01

    Cereś surface is affected by numerous impact craters and some of them show features such as channels or multiple flow events forming a smooth, less cratered surface, indicating possible post-impact resurfacing.

  13. Greenland Ice Flow

    NASA Image and Video Library

    Greenland looks like a big pile of snow seen from space using a regular camera. But satellite radar interferometry helps us detect the motion of ice beneath the snow. Ice starts flowing from the fl...

  14. Complex Flow Workshop Report

    SciTech Connect

    none,

    2012-05-01

    This report documents findings from a workshop on the impacts of complex wind flows in and out of wind turbine environments, the research needs, and the challenges of meteorological and engineering modeling at regional, wind plant, and wind turbine scales.

  15. RG flows and instantons

    SciTech Connect

    Gava, Edi

    2012-09-24

    In these two lectures I discuss RG flow solutions in (1,0) six dimensional supergravity involving SU(2) Yang-Mills instantons. in the conformally flat part of the 6D metric. The solutions interpolate between two (4,0) supersymmetric AdS{sub 3} Multiplication-Sign S{sup 3} backgrounds with different values of AdS{sub 3} and S{sup 3} radii and describe RG flows in the dual 2D SCFT. The flows described are of v.e.v. type, driven by a vacuum expectation value of a (not exactly) marginal operator of dimension 2 in the UV. We give an interpretation of the supergravity solution in terms of the D1/D5 system in type I string theory on K3, whose effective field theory is expected to flow to a (4,0) SCFT in the infrared.

  16. Cash Flow Planning.

    ERIC Educational Resources Information Center

    Littman, George W., III

    1979-01-01

    Proper cash flow planning allows a school business administrator to determine the availability of cash for operating expenses, the need for bank loans to cover these expenses, and the availability of idle cash for investment. (Author)

  17. Kamoamoa Flow Field Animation

    NASA Image and Video Library

    2012-02-06

    This frame from an animation, which depicts the growth of the Kamoamoa Flow Field, Kilauea Volcano, Hawaii, was generated from a sequence of ten multispectral images acquired between September 3 and 17, 1995.

  18. Laminar-flow airfoil

    NASA Technical Reports Server (NTRS)

    Somers, Dan M. (Inventor)

    2005-01-01

    An airfoil having a fore airfoil element, an aft airfoil element, and a slot region in between them. These elements induce laminar flow over substantially all of the fore airfoil element and also provide for laminar flow in at least a portion of the slot region. The method of the invention is one for inducing natural laminar flow over an airfoil. In the method, a fore airfoil element, having a leading and trailing edge, and an aft airfoil element define a slot region. Natural laminar flow is induced over substantially all of the fore airfoil element, by inducing the pressures on both surfaces of the fore airfoil element to decrease to a location proximate the trailing edge of the fore airfoil element using pressures created by the aft airfoil element.

  19. Visualising patient flow.

    PubMed

    Jensen, Andrew; Boyle, Justin; Khanna, Sankalp

    2012-01-01

    We describe the development of a method to distil routinely collected clinical data into patient flow information to aid hospital bed management. Using data from state-wide emergency department and inpatient clinical information systems, a user-friendly interface was developed to visualise patient flow conditions for a particular hospital. The historical snapshots employ a variable time scale, allowing flow to be visualised across a day, week, month or year. Flow information includes occupancy, arrival and departure rates, length-of-stay and access block observations, which can be filtered by age, departure status, diagnosis, elective status, triage category, and admission unit. The tool may be helpful in supporting hospital bed managers in their daily decision making.

  20. An orographic flow diagramme

    NASA Astrophysics Data System (ADS)

    Opsanger Jonassen, Marius; Ólafsson, Haraldur; Ágústsson, Hálfdán

    2017-04-01

    Elevated temperature inversions are recognised to potentially have a significant impact on flow over and around mountains. In this study, we devise a new flow diagram for flow over mountains in the presence of such an inversion using a suite of numerical simulations. The simulations are carried out with the WRF model and open boundary conditions are applied. A neutral boundary layer is capped by a 10K inversion, of which the height varies. The mountain is 1 km high and the upstream wind speeds are 10, 15, 20, 25 or 30 m/s. The surface has zo=0.1m. Vortices, vortex shedding, lee waves and hydraulic jump are detected and related to values of the height of the inversion and the shallow water Froude number. Cases of real flow are compared to the idealized results.

  1. Digital work-flow

    PubMed Central

    MARSANGO, V.; BOLLERO, R.; D’OVIDIO, N.; MIRANDA, M.; BOLLERO, P.; BARLATTANI, A.

    2014-01-01

    SUMMARY Objective. The project presents a clinical case in which the digital work-flow procedure was applied for a prosthetic rehabilitation in natural teeth and implants. Materials. Digital work-flow uses patient’s photo for the aesthetic’s planning, digital smile technology for the simulation of the final restoration and real time scanning to register the two arches. Than the scanning are sent to the laboratory that proceed with CAD-CAM production. Results. Digital work-flow offers the opportunities to easily speak with laboratory and patients, gives better clinical results and demonstrated to be a less invasiveness method for the patient. Conclusion. Intra-oral scanner, digital smile design, preview using digital wax-up, CAD-CAM production, are new predictable opportunities for prosthetic team. This work-flow, compared with traditional methods, is faster, more precise and predictable. PMID:25694797

  2. Martian Lava Flows

    NASA Technical Reports Server (NTRS)

    2005-01-01

    19 October 2005 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows lava flows at the southeast base of the giant volcano, Olympus Mons. The flat plain in the south-southeast (bottom/lower right) portion of the image is younger than and cuts off the ends of many of the lava flows that came from the northwest (upper left). Many of the lava flows in this image exhibit channels with levees bounding their margins. As each lava flow was advancing, its outer margins cooled and hardened, forming a channel or tube through which the molten rock continued to advance.

    Location near: 17.2oN, 129.0oW Image width: width: 3 km (1.9 mi) Illumination from: lower left Season: Northern Winter

  3. The Flow of Sand.

    ERIC Educational Resources Information Center

    Yersel, Metin

    2000-01-01

    Describes a simple demonstration of the flow of sand through an orifice at the bottom of a sandbox. Advocates the experiment's use with dimensional analysis for students in an introductory physics course. (WRM)

  4. Olympus Mons Flows

    NASA Image and Video Library

    2002-12-19

    Like drippings from a candle, these lava flows on the flank of Olympus Mons volcano, seen in this image from NASA Mars Odyssey spacecraft, demonstrate how it became the largest volcano in the solar system.

  5. Web life: Ice Flows

    NASA Astrophysics Data System (ADS)

    2016-11-01

    Computer and video gamers of a certain vintage will have fond memories of Lemmings, a game in which players must shepherd pixelated, suicidal rodents around a series of obstacles to reach safety. At first glance, Ice Flows is strikingly similar.

  6. Optimal Flow Control Design

    NASA Technical Reports Server (NTRS)

    Allan, Brian; Owens, Lewis

    2010-01-01

    In support of the Blended-Wing-Body aircraft concept, a new flow control hybrid vane/jet design has been developed for use in a boundary-layer-ingesting (BLI) offset inlet in transonic flows. This inlet flow control is designed to minimize the engine fan-face distortion levels and the first five Fourier harmonic half amplitudes while maximizing the inlet pressure recovery. This concept represents a potentially enabling technology for quieter and more environmentally friendly transport aircraft. An optimum vane design was found by minimizing the engine fan-face distortion, DC60, and the first five Fourier harmonic half amplitudes, while maximizing the total pressure recovery. The optimal vane design was then used in a BLI inlet wind tunnel experiment at NASA Langley's 0.3-meter transonic cryogenic tunnel. The experimental results demonstrated an 80-percent decrease in DPCPavg, the reduction in the circumferential distortion levels, at an inlet mass flow rate corresponding to the middle of the operational range at the cruise condition. Even though the vanes were designed at a single inlet mass flow rate, they performed very well over the entire inlet mass flow range tested in the wind tunnel experiment with the addition of a small amount of jet flow control. While the circumferential distortion was decreased, the radial distortion on the outer rings at the aerodynamic interface plane (AIP) increased. This was a result of the large boundary layer being distributed from the bottom of the AIP in the baseline case to the outer edges of the AIP when using the vortex generator (VG) vane flow control. Experimental results, as already mentioned, showed an 80-percent reduction of DPCPavg, the circumferential distortion level at the engine fan-face. The hybrid approach leverages strengths of vane and jet flow control devices, increasing inlet performance over a broader operational range with significant reduction in mass flow requirements. Minimal distortion level requirements

  7. Patterning flows and polymers

    NASA Astrophysics Data System (ADS)

    Stroock, Abraham Duncan

    This thesis presents the use of patterned surfaces for controlling fluid dynamics on a sub-millimeter scale, and for fabricating a new class of polymeric materials. In chapters 1--4, chemical and mechanical structures were used to control the form of flows of fluids in microchannels. This work was done in the context of the development of microfluidic technology for performing chemical tasks in portable, integrated devices. Chapter 1 reviews this work for an audience of chemists who are potential users of these techniques in the development of micro-analytical and micro-synthetic devices. Appendix 1 contains a more general review of microfluidics. Chapter 2 presents experimental results on the use of patterned surface charge density to create new electroosmotic (EO) flows in microchannels; the chapter includes a successful model of the observed flows. In Chapter 3, patterns of topography on the wall of a microchannel were used to generate recirculation in pressure-driven flows. The design and characterization of an efficient mixer based on these flows is presented. A theoretical treatment of these flows is given in Appendix 2. The experimental methods used for the work with both EO and pressure-driven flows are presented in Chapter 4. In Chapter 5, a pattern of asymmetrical grooves in a heated plate was used to perturb Marangoni-Benard (M-B) convection, a dynamic system that spontaneously forms patterned flows. The interaction of the imposed pattern and the inherent pattern of the M-B convection led to a net flow in the plane of convecting layer of fluid. The direction of this flow depended on the orientation of the asymmetrical grooves, the temperature difference across the layer, and the thickness of the layer. A phenomenological model is presented to explain this ratchet effect in which local recirculation was coupled into a global flow. In Chapter 6, surfaces patterned by microcontact printing were used as a workbench on which to build molecularly thin polymer

  8. Magnetically stimulated fluid flow patterns

    ScienceCinema

    Martin, Jim; Solis, Kyle

    2016-07-12

    Sandia National Laboratories' Jim Martin and Kyle Solis explain research on the effects of magnetic fields on fluid flows and how they stimulate vigorous flows. Fluid flow is a necessary phenomenon in everything from reactors to cooling engines in cars.

  9. Magnetically stimulated fluid flow patterns

    SciTech Connect

    Martin, Jim; Solis, Kyle

    2014-03-06

    Sandia National Laboratories' Jim Martin and Kyle Solis explain research on the effects of magnetic fields on fluid flows and how they stimulate vigorous flows. Fluid flow is a necessary phenomenon in everything from reactors to cooling engines in cars.

  10. Oscillating stagnation point flow

    NASA Technical Reports Server (NTRS)

    Grosch, C. E.; Salwen, H.

    1982-01-01

    A solution of the Navier-Stokes equations is given for an incompressible stagnation point flow whose magnitude oscillates in time about a constant, non-zero, value (an unsteady Hiemenz flow). Analytic approximations to the solution in the low and high frequency limits are given and compared with the results of numerical integrations. The application of these results to one aspect of the boundary layer receptivity problem is also discussed.

  11. Oscillating stagnation point flow

    NASA Astrophysics Data System (ADS)

    Grosch, C. E.; Salwen, H.

    1982-11-01

    A solution of the Navier-Stokes equations is given for an incompressible stagnation point flow whose magnitude oscillates in time about a constant, non-zero, value (an unsteady Hiemenz flow). Analytic approximations to the solution in the low and high frequency limits are given and compared with the results of numerical integrations. The application of these results to one aspect of the boundary layer receptivity problem is also discussed.

  12. MHD Flow Control

    DTIC Science & Technology

    2006-09-01

    tested is a model to simulate the hypersonic intake configuration. The corresponding photo is presented in Fig. 49. 75 i I I I I I I Figure 49. The third... hypersonic air stream within the propulsion system inlet. The extra benefit of this proposed Project is the experimental facility to be used for experimental...plasma aerodynamics, and in particular, MHD control of external and internal flows. The MHD control of the external hypersonic flow over the simplest

  13. High Speed Vortex Flows

    NASA Technical Reports Server (NTRS)

    Wood, Richard M.; Wilcox, Floyd J., Jr.; Bauer, Steven X. S.; Allen, Jerry M.

    2000-01-01

    A review of the research conducted at the National Aeronautics and Space Administration (NASA), Langley Research Center (LaRC) into high-speed vortex flows during the 1970s, 1980s, and 1990s is presented. The data reviewed is for flat plates, cavities, bodies, missiles, wings, and aircraft. These data are presented and discussed relative to the design of future vehicles. Also presented is a brief historical review of the extensive body of high-speed vortex flow research from the 1940s to the present in order to provide perspective of the NASA LaRC's high-speed research results. Data are presented which show the types of vortex structures which occur at supersonic speeds and the impact of these flow structures to vehicle performance and control is discussed. The data presented shows the presence of both small- and large scale vortex structures for a variety of vehicles, from missiles to transports. For cavities, the data show very complex multiple vortex structures exist at all combinations of cavity depth to length ratios and Mach number. The data for missiles show the existence of very strong interference effects between body and/or fin vortices and the downstream fins. It was shown that these vortex flow interference effects could be both positive and negative. Data are shown which highlights the effect that leading-edge sweep, leading-edge bluntness, wing thickness, location of maximum thickness, and camber has on the aerodynamics of and flow over delta wings. The observed flow fields for delta wings (i.e. separation bubble, classical vortex, vortex with shock, etc.) are discussed in the context of' aircraft design. And data have been shown that indicate that aerodynamic performance improvements are available by considering vortex flows as a primary design feature. Finally a discussing of a design approach for wings which utilize vortex flows for improved aerodynamic performance at supersonic speed is presented.

  14. Entropy of stochastic flows

    SciTech Connect

    Dorogovtsev, Andrei A

    2010-06-29

    For sets in a Hilbert space the concept of quadratic entropy is introduced. It is shown that this entropy is finite for the range of a stochastic flow of Brownian particles on R. This implies, in particular, the fact that the total time of the free travel in the Arratia flow of all particles that started from a bounded interval is finite. Bibliography: 10 titles.

  15. Extra Terrestrial Lava Flows

    NASA Technical Reports Server (NTRS)

    Lopes-Gautier, R.

    1993-01-01

    Volcanism has been one of the major processes shaping the surfaces of the terrestrial planets. Lava flows have been identified on the Moon, Mars, Venus, and on Juptier's moon Io. The study of extra-terrestrial lavas has largely relied on the interpretation of remotely acquired imaging, topographic and spectroscopic data. Models relating the final flow morpohology to eruption characteristics and magma chemistry have been important tools in the interpretation of these data.

  16. Go With the Flow

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Based on work begun in the 1970s, Analytical Methods, Inc. (AMI) developed computational fluid dynamics (CFD) technology called VSAERO. VSAERO can image aerodynamic flows and has been used in a number of unique designs such as the U.S. sailboat used in the 1996 America's Cup, solar automobiles, and solar airplaces. VSAERO is applicable to fluid flow problems in aerospace, aeronautical, automotive, and marine engineering.

  17. Multiplex Flow Assays

    PubMed Central

    2016-01-01

    Lateral flow or dipstick assays (e.g., home pregnancy tests), where an analyte solution is drawn through a porous membrane and is detected by localization onto a capture probe residing at a specific site on the flow strip, are the most commonly and extensively used type of diagnostic assay. However, after over 30 years of use, these assays are constrained to measuring one or a few analytes at a time. Here, we describe a completely general method, in which any single-plex lateral flow assay is transformed into a multiplex assay capable of measuring an arbitrarily large number of analytes simultaneously. Instead of identifying the analyte by its localization onto a specific geometric location in the flow medium, the analyte-specific capture probe is identified by its association with a specific optically encoded region within the flow medium. The capture probes for nucleic acids, antigens, or antibodies are attached to highly porous agarose beads, which have been encoded using multiple lanthanide emitters to create a unique optical signature for each capture probe. The optically encoded capture probe-derivatized beads are placed in contact with the analyte-containing porous flow medium and the analytes are captured onto the encoded regions as the solution flows through the porous medium. To perform a multiplex diagnostic assay, a solution comprising multiple analytes is passed through the flow medium containing the capture probe-derivatized beads, and the captured analyte is treated with a suitable fluorescent reporter. We demonstrate this multiplex analysis technique by simultaneously measuring DNA samples, antigen–antibody pairs, and mixtures of multiple nucleic acids and antibodies. PMID:27819063

  18. Go With the Flow

    NASA Technical Reports Server (NTRS)

    1998-01-01

    Under SBIR (Small Business Innovative Research) contracts with Lewis Research Center, Nektonics, Inc., developed coating process simulation tools, known as Nekton. This powerful simulation software is used specifically for the modeling and analysis of a wide range of coating flows including thin film coating analysis, polymer processing, and glass melt flows. Polaroid, Xerox, 3M, Dow Corning, Mead Paper, BASF, Mitsubishi, Chugai, and Dupont Imaging Systems are only a few of the companies that presently use Nekton.

  19. Cryogenic Flow Sensor

    NASA Technical Reports Server (NTRS)

    Justak, John

    2010-01-01

    An acousto-optic cryogenic flow sensor (CFS) determines mass flow of cryogens for spacecraft propellant management. The CFS operates unobtrusively in a high-pressure, high-flowrate cryogenic environment to provide measurements for fluid quality as well as mass flow rate. Experimental hardware uses an optical plane-of-light (POL) to detect the onset of two-phase flow, and the presence of particles in the flow of water. Acousto-optic devices are used in laser equipment for electronic control of the intensity and position of the laser beam. Acousto-optic interaction occurs in all optical media when an acoustic wave and a laser beam are present. When an acoustic wave is launched into the optical medium, it generates a refractive index wave that behaves like a sinusoidal grating. An incident laser beam passing through this grating will diffract the laser beam into several orders. Its angular position is linearly proportional to the acoustic frequency, so that the higher the frequency, the larger the diffracted angle. If the acoustic wave is traveling in a moving fluid, the fluid velocity will affect the frequency of the traveling wave, relative to a stationary sensor. This frequency shift changes the angle of diffraction, hence, fluid velocity can be determined from the diffraction angle. The CFS acoustic Bragg grating data test indicates that it is capable of accurately determining flow from 0 to 10 meters per second. The same sensor can be used in flow velocities exceeding 100 m/s. The POL module has successfully determined the onset of two-phase flow, and can distinguish vapor bubbles from debris.

  20. Electrochemical flow capacitors

    DOEpatents

    Gogotsi, Yury; Presser, Volker; Kumbur, Emin Caglan

    2015-10-27

    The present invention generally relates to devices for energy storage technologies, and more particularly to electrochemical flow capacitor systems and applications. In some aspects, these flow capacitors have at least one electrode comprising a non-stationary solid or semi-solid composition comprising supercapacitive particles and an electrolytic solvent in electrical communication with at least one current collector, and energy is stored and/or released by charging and/or discharging the electrode(s).

  1. Secondary Flows in Turbomachines

    DTIC Science & Technology

    1990-02-01

    transfer coefficient . A fluorescent dye flow visualization technique was used in the annular cascade test to aid in interpretation. Detailed...that rotation increases the heat transfer coefficient . Experimental evidence is provided and is supported by three-dimensional Navier-Stokes...diffusive mixing due to the random effects of turbulence is modeled by empirical coefficients . The flow field on the S3-surface is reconstructed from

  2. Conjugate flow action functionals

    SciTech Connect

    Venturi, Daniele

    2013-11-15

    We present a new general framework to construct an action functional for a non-potential field theory. The key idea relies on representing the governing equations relative to a diffeomorphic flow of curvilinear coordinates which is assumed to be functionally dependent on the solution field. Such flow, which will be called the conjugate flow, evolves in space and time similarly to a physical fluid flow of classical mechanics and it can be selected in order to symmetrize the Gâteaux derivative of the field equations with respect to suitable local bilinear forms. This is equivalent to requiring that the governing equations of the field theory can be derived from a principle of stationary action on a Lie group manifold. By using a general operator framework, we obtain the determining equations of such manifold and the corresponding conjugate flow action functional. In particular, we study scalar and vector field theories governed by second-order nonlinear partial differential equations. The identification of transformation groups leaving the conjugate flow action functional invariant could lead to the discovery of new conservation laws in fluid dynamics and other disciplines.

  3. Conjugate flow action functionals

    NASA Astrophysics Data System (ADS)

    Venturi, Daniele

    2013-11-01

    We present a new general framework to construct an action functional for a non-potential field theory. The key idea relies on representing the governing equations relative to a diffeomorphic flow of curvilinear coordinates which is assumed to be functionally dependent on the solution field. Such flow, which will be called the conjugate flow, evolves in space and time similarly to a physical fluid flow of classical mechanics and it can be selected in order to symmetrize the Gâteaux derivative of the field equations with respect to suitable local bilinear forms. This is equivalent to requiring that the governing equations of the field theory can be derived from a principle of stationary action on a Lie group manifold. By using a general operator framework, we obtain the determining equations of such manifold and the corresponding conjugate flow action functional. In particular, we study scalar and vector field theories governed by second-order nonlinear partial differential equations. The identification of transformation groups leaving the conjugate flow action functional invariant could lead to the discovery of new conservation laws in fluid dynamics and other disciplines.

  4. Sperm Motility in Flow

    NASA Astrophysics Data System (ADS)

    Guasto, Jeffrey; Juarez, Gabriel; Stocker, Roman

    2012-11-01

    A wide variety of plants and animals reproduce sexually by releasing motile sperm that seek out a conspecific egg, for example in the reproductive tract for mammals or in the water column for externally fertilizing organisms. Sperm are aided in their quest by chemical cues, but must also contend with hydrodynamic forces, resulting from laminar flows in reproductive tracts or turbulence in aquatic habitats. To understand how velocity gradients affect motility, we subjected swimming sperm to a range of highly-controlled straining flows using a cross-flow microfluidic device. The motion of the cell body and flagellum were captured through high-speed video microscopy. The effects of flow on swimming are twofold. For moderate velocity gradients, flow simply advects and reorients cells, quenching their ability to cross streamlines. For high velocity gradients, fluid stresses hinder the internal bending of the flagellum, directly inhibiting motility. The transition between the two regimes is governed by the Sperm number, which compares the external viscous stresses with the internal elastic stresses. Ultimately, unraveling the role of flow in sperm motility will lead to a better understanding of population dynamics among aquatic organisms and infertility problems in humans.

  5. Reversing Flow Test Facility

    NASA Astrophysics Data System (ADS)

    Roach, P. D.

    1986-04-01

    The Reversing Flow Test Facility (RFTF) is intended for the study of fluid flow and heat transfer under the reversing-flow conditions that occur in Stirling engines. The facility consists of four major parts: (1) Mechanical Drive - two cylinders with cam-driven pistons which generate the reversing gas flow, (2) Test Section - a U-shaped section containing instrumented test pieces, (3) Instruments -l high-speed transducers for measuring gas pressure and temperature, piston positions, and other system parameters, and (4) Data Acquisition System - a computer-based system able to acquire, store, display and analyze the data from the instruments. The RFTF can operate at pressures up to 8.0 MPa, hot-side temperatures to 800 deg. C, and flow-reversal frequencies to 50 Hz. Operation to data has used helium as the working gas at pressures of 3.0 and 6.0 MPa, at ambient temperature, and at frequencies from 1 to 50 Hz. The results show that both frictional and inertial parts of the pressure drop are significant in the heater, coolers and connecting tubes; the inertial part is negligible in the regenerators. In all cases, the frictional part of the pressure drop is nearly in phase with the mass flow.

  6. Elastic Granular Flows

    NASA Astrophysics Data System (ADS)

    Campbell, Charles

    2006-03-01

    There is no fundamental understanding of the mechanics of granular solids. Partially this is because granular flows have historically been divided into two very distinct flow regimes, (1) the slow, quasistatic regime, in which the bulk friction coefficient is taken to be a material constant, and (2) the fast, rapid-flow regime, where the particles interact collisionally. But slow hopper flow simulations indicate that the bulk friction coefficient is not a constant. Rapidly moving large scale landslide simulations never entered the collisional regime and operate in a separate intermediate flow regime. In other words, most realistic granular flows are not described by either the quasistatic or rapid flow models and it is high time that the field look beyond those early models. This talk will discuss computer simulation studies that draw out the entire flowmap of shearing granular materials, spanning the quasistatic, rapid and the intermediate regimes. The key was to include the elastic properties of the solid material in the set of rheological parameters; in effect, this puts solid properties back into the rheology of granular solids. The solid properties were previously unnecessary in the plasticity and kinetic theory formalisms that respectively form the foundations of the quasistatic and rapid-flow theories. Granular flows can now be divided into two broad categories, the Elastic Regimes, in which the particles are locked in force chains and interact elastically over long duration contact with their neighbors and the Inertial regimes, where the particles have broken free of the force chains. The Elastic regimes can be further subdivided into the Elastic-Quasistatic regime (the old quasistatic regime) and the Elastic-Inertial regime. The Elastic-Inertial regime is the ``new'' regime observed in the landslide simulations, in which the inertially induced stresses are significant compared to the elastically induced stresses. The Inertial regime can also be sub

  7. Which Way Is the Flow?

    NASA Technical Reports Server (NTRS)

    Kao, David

    1999-01-01

    The line integral convolution (LIC) technique has been known to be an effective tool for depicting flow patterns in a given vector field. There have been many extensions to make it run faster and reveal useful flow information such as velocity magnitude, motion, and direction. There are also extensions to unsteady flows and 3D vector fields. Surprisingly, none of these extensions automatically highlight flow features, which often represent the most important and interesting physical flow phenomena. In this sketch, a method for highlighting flow direction in LIC images is presented. The method gives an intuitive impression of flow direction in the given vector field and automatically reveals saddle points in the flow.

  8. Planetary heat flow measurements.

    PubMed

    Hagermann, Axel

    2005-12-15

    The year 2005 marks the 35th anniversary of the Apollo 13 mission, probably the most successful failure in the history of manned spaceflight. Naturally, Apollo 13's scientific payload is far less known than the spectacular accident and subsequent rescue of its crew. Among other instruments, it carried the first instrument designed to measure the flux of heat on a planetary body other than Earth. The year 2005 also should have marked the launch of the Japanese LUNAR-A mission, and ESA's Rosetta mission is slowly approaching comet Churyumov-Gerasimenko. Both missions carry penetrators to study the heat flow from their target bodies. What is so interesting about planetary heat flow? What can we learn from it and how do we measure it?Not only the Sun, but all planets in the Solar System are essentially heat engines. Various heat sources or heat reservoirs drive intrinsic and surface processes, causing 'dead balls of rock, ice or gas' to evolve dynamically over time, driving convection that powers tectonic processes and spawns magnetic fields. The heat flow constrains models of the thermal evolution of a planet and also its composition because it provides an upper limit for the bulk abundance of radioactive elements. On Earth, the global variation of heat flow also reflects the tectonic activity: heat flow increases towards the young ocean ridges, whereas it is rather low on the old continental shields. It is not surprising that surface heat flow measurements, or even estimates, where performed, contributed greatly to our understanding of what happens inside the planets. In this article, I will review the results and the methods used in past heat flow measurements and speculate on the targets and design of future experiments.

  9. Flow: Statistics, visualization and informatics for flow cytometry

    PubMed Central

    Frelinger, Jacob; Kepler, Thomas B; Chan, Cliburn

    2008-01-01

    Flow is an open source software application for clinical and experimental researchers to perform exploratory data analysis, clustering and annotation of flow cytometric data. Flow is an extensible system that offers the ease of use commonly found in commercial flow cytometry software packages and the statistical power of academic packages like the R BioConductor project. PMID:18559108

  10. Heat flow in Oklahoma

    NASA Astrophysics Data System (ADS)

    Cranganu, Constantin

    Twenty new heat flow values are incorporated, along with 40 previously published data, into a heat flow map of Oklahoma. The new heat flow data were estimated using previous temperature measurements in boreholes made by American Petroleum Institute researchers and 1,498 thermal conductivity measurements on drill cuttings. The mean of 20 average thermal gradients is 30.50sp°C/km. In general, thermal gradients increase from SW (14.11sp°C/km) to NE (42.24sp°C/km). The range of 1,498 in situ thermal conductivity measurements (after corrections for anisotropy, in situ temperature, and porosity) is 0.90-6.1 W/m-K; the average is 1.68 W/m-K. Estimated near-surface heat flow (±20%) at 20 new sites in Oklahoma varies between 22 ± 4 mW/msp2 and 86 ± 17 mW/msp2; the average is 50 mW/msp2. Twenty-seven new heat-generation estimates, along with 22 previously published data, are used to create a heat generation map of Oklahoma. The range of heat production estimates is 1.1-3.5 muW/msp3, with an average of 2.5 muW/msp3. The heat flow regime in Oklahoma is primarily conductive in nature, except for a zone in northeast. Transient effects due to sedimentary processes and metamorphic/igneous activity, as well as past climatic changes, do not significantly influence the thermal state of the Oklahoma crust. Heat flow near the margins of the Arkoma and Anadarko Basins may be depressed or elevated by 5-13 mW/msp2 by refraction of heat from sedimentary rocks of relatively low thermal conductivity (1-2 W/m-K) into crystalline basement rocks of relatively high thermal conductivity (˜3-4 W/m-K). The heat generation-heat flow relationship shows a modest correlation. The relatively high heat flow (˜70-80 mW/msp2) in part of northeastern Oklahoma suggests that the thermal regime there may be perturbed by regional groundwater flow originating in the fractured outcrops of the Arbuckle-Simpson aquifer in the Arbuckle Mountains.

  11. National Flow Cytometry Resource

    SciTech Connect

    Bell-Prince, C.; Dickson, J.A.; Jett, J.H.; Stevenson, A.P.; Sklar, L.A. )

    1993-01-01

    thee National Flow Cytometry and Sorting Resource (NFCR) was established in 1982 to develop advanced flow cytometric instrumentation and methodology, to provide facilities for using the fruits of the NFCR developments in collaborative projects and to disseminate the results to the cytometry community at large. Achievements of the NFCR for 1992 include: (1) preliminary studies of DNA inactivation in preparation for the development of an optical chromosome sorter; (2) modeling of real-time cytometry data using th ISML software package on a Cray supercomputer; (3) execution of proof-of-principle experiments on a phase sensitive flow cytometer in which cellular fluorescence lifetimes were determined; (4) continued development of the DiDAC data acquisition system to include bit mapped sorting and multi-laser capabilities; (5) development of new display modalities for flow cytometric data using the high level graphics language IDL; (6) development and testing of new approaches to clustering of multivariate data; (7) novel applications of Fourier transform flow cytometry to questions of cell activation and molecular structure.

  12. Lava That Once Flowed

    NASA Image and Video Library

    2016-10-19

    This image shows some beautiful lava flows in Amazonis Planitia. Lava isn't moving around on Mars today, but it certainly once did, and images like this one are evidence of that. A thick lava flow came in from the west, and you can see the cooled flow lobes and wrinkled upper surface. East of the flow margin, this most recent flow also coursed over an older lava surface which shows some long, north-south breaks, and in the southeast corner, an arrowhead-shaped set of ridges. These textures are most likely from rafted slabs of lava. Under certain conditions, a large piece of lava can cool, but then detach and move like an iceberg over a cushion of still-molten lava. The long, narrow north-south smooth areas are probably where two of these plates rafted away from one another exposing the lava below. The arrowhead-shaped ridges are probably from when one of these plates pushed up against another one and caused a pile-up before cooling. http://photojournal.jpl.nasa.gov/catalog/PIA21113

  13. Upscaling of Forchheimer flows

    NASA Astrophysics Data System (ADS)

    Aulisa, Eugenio; Bloshanskaya, Lidia; Efendiev, Yalchin; Ibragimov, Akif

    2014-08-01

    In this work we propose upscaling method for nonlinear Forchheimer flow in heterogeneous porous media. The generalized Forchheimer law is considered for incompressible and slightly-compressible single-phase flows. We use recently developed analytical results (Aulisa et al., 2009) [1] and formulate the resulting system in terms of a degenerate nonlinear flow equation for the pressure with the nonlinearity depending on the pressure gradient. The coarse scale parameters for the steady state problem are determined so that the volumetric average of velocity of the flow in the domain on fine scale and on coarse scale are close. A flow-based coarsening approach is used, where the equivalent permeability tensor is first evaluated following streamline methods for linear cases, and modified in order to take into account the nonlinear effects. Compared to previous works (Garibotti and Peszynska, 2009) [2], (Durlofsky and Karimi-Fard) [3], this approach can be combined with rigorous mathematical upscaling theory for monotone operators, (Efendiev et al., 2004) [4], using our recent theoretical results (Aulisa et al., 2009) [1]. The developed upscaling algorithm for nonlinear steady state problems is effectively used for variety of heterogeneities in the domain of computation. Direct numerical computations for average velocity and productivity index justify the usage of the coarse scale parameters obtained for the special steady state case in the fully transient problem. For nonlinear case analytical upscaling formulas in stratified domain are obtained. Numerical results were compared to these analytical formulas and proved to be highly accurate.

  14. Piezoelectric axial flow microvalve

    DOEpatents

    Gemmen, Randall; Thornton, Jimmy; Vipperman, Jeffrey S.; Clark, William W.

    2007-01-09

    This invention is directed to a fuel cell operable with a quantity of fuel and a quantity of an oxidizer to produce electrical power, the fuel cell including a fuel cell body including a labyrinth system structured to permit the fuel and the oxidizer to flow therethrough; at least a first catalyst in fluid communication with the labyrinth; and at least a first microvalve operably disposed within at least a portion of the labyrinth. The microvalve utilizes a deflectable member operable upon the application of a voltage from a voltage source. The microvalve includes an elongated flow channel formed therein and extending substantially longitudinally between the first and second ends to permit substantially longitudinal flow of the fluid therethrough and between the first and second ends; and the deflectable member disposed on the valve body, the deflectable member including at least a first piezoelectric portion that is piezoelectrically operable to deflect the deflectable member between an open position and a closed position upon the application of a voltage, the deflectable member in the closed position being operable to resist the flow of the fluid through the flow channel.

  15. Rokhlin Dimension for Flows

    NASA Astrophysics Data System (ADS)

    Hirshberg, Ilan; Szabó, Gábor; Winter, Wilhelm; Wu, Jianchao

    2016-10-01

    We introduce a notion of Rokhlin dimension for one parameter automorphism groups of {C^*} -algebras. This generalizes Kishimoto's Rokhlin property for flows, and is analogous to the notion of Rokhlin dimension for actions of the integers and other discrete groups introduced by the authors and Zacharias in previous papers. We show that finite nuclear dimension and absorption of a strongly self-absorbing {C^*} -algebra are preserved under forming crossed products by flows with finite Rokhlin dimension, and that these crossed products are stable. Furthermore, we show that a flow on a commutative {C^*} -algebra arising from a free topological flow has finite Rokhlin dimension, whenever the spectrum is a locally compact metrizable space with finite covering dimension. For flows that are both free and minimal, this has strong consequences for the associated crossed product {C^{*}} -algebras: Those containing a non-zero projection are classified by the Elliott invariant (for compact manifolds this consists of topological {K} -theory together with the space of invariant probability measures and a natural pairing given by the Ruelle-Sullivan map).

  16. Flocking in Flow

    NASA Astrophysics Data System (ADS)

    Ouellette, Nicholas; Khurana, Nidhi

    2013-03-01

    Models of active, self-propelled particles with simple interaction rules have long been shown to produce large-scale emergent behavior reminiscent of collective animal motion seen in nature. Such model flocks can be shown to be robust against random noise terms added to the equations. But real animals, such as birds, fish, or insects, live in fluid environments, where the background flow field is nonzero and is often turbulent. In this case, the fluctuations experienced by the individuals in the aggregation are not random, but rather are correlated in space and time. We explore the impact of such spatiotemporally correlated perturbations on flocking by numerically simulating the behavior of a simple flocking model in a turbulent-like flow field produced by a kinematic simulation. The introduction of flow strongly changes the flock formation dynamics. Additionally, we find that under some conditions the background flow tends to break stable flocks into smaller units. We study these clusters, and discuss their relation to the underlying flow field.

  17. Rokhlin Dimension for Flows

    NASA Astrophysics Data System (ADS)

    Hirshberg, Ilan; Szabó, Gábor; Winter, Wilhelm; Wu, Jianchao

    2017-07-01

    We introduce a notion of Rokhlin dimension for one parameter automorphism groups of {C^*}-algebras. This generalizes Kishimoto's Rokhlin property for flows, and is analogous to the notion of Rokhlin dimension for actions of the integers and other discrete groups introduced by the authors and Zacharias in previous papers. We show that finite nuclear dimension and absorption of a strongly self-absorbing {C^*}-algebra are preserved under forming crossed products by flows with finite Rokhlin dimension, and that these crossed products are stable. Furthermore, we show that a flow on a commutative {C^*}-algebra arising from a free topological flow has finite Rokhlin dimension, whenever the spectrum is a locally compact metrizable space with finite covering dimension. For flows that are both free and minimal, this has strong consequences for the associated crossed product {C^{*}}-algebras: Those containing a non-zero projection are classified by the Elliott invariant (for compact manifolds this consists of topological {K}-theory together with the space of invariant probability measures and a natural pairing given by the Ruelle-Sullivan map).

  18. Marte Vallis Platy Flows

    NASA Technical Reports Server (NTRS)

    2003-01-01

    MGS MOC Release No. MOC2-442, 4 August 2003

    The Marte Vallis system, located east of Cerberus and west of Amazonis Planitia, is known for its array of broken, platy flow features. This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a close-up view of some of these plates; they appear to be like puzzle pieces that have been broken apart and moved away from each other. The Mars science community has been discussing these features for the past several years--either the flows in Marte Vallis are lava flows, or mud flows. In either case, the material was very fluid and had a thin crust on its surface. As the material continued to flow through the valley system, the crust broke up into smaller plates that were then rafted some distance down the valley. This picture is located near 6.9oN, 182.8oW. It is illuminated by sunlight from the left.

  19. Two-phase flow

    NASA Technical Reports Server (NTRS)

    Tacina, Robert R.

    1986-01-01

    An experimental program to characterize the spray from candidate nozzles for icing-cloud simulation is discussed. One canidate nozzle, which is currently used for icing research, has been characterized for flow and drop size. The median-volume diameter (MVD) from this air-assist nozzle is compared with correlations in the literature. The new experimental spray facility is discussed, and the drop-size instruments are discussed in detail. Since there is no absolute standard for drop-size measurements and there are other limitations, such as drop -size range and velocity range, several instruments are used and results are compared. A two-phase model was developed at Pennsylvania State University. The model uses the k-epsilon model of turbulence in the continous phase. Three methods for treating the discrete phase are used: (1) a locally homogeneous flow (LHF) model, (2) a deterministic separated flow (DSF) model, and (3) a stochastic separated flow (SSF) model. In the LHF model both phases have the same velocity and temperature at each point. The DSF model provides interphase transport but ignores the effects of turbulent fluctuations. In the SSF model the drops interact with turbulent eddies whose properties are determined by the k-epsilon turbulence model. The two-phase flow model has been extended to include the effects of evaporation and combustion.

  20. Chemical reacting flows

    NASA Astrophysics Data System (ADS)

    Mularz, Edward J.; Sockol, Peter M.

    1990-02-01

    Future aerospace propulsion concepts involve the combustion of liquid or gaseous fuels in a highly turbulent internal airstream. Accurate predictive computer codes which can simulate the fluid mechanics, chemistry, and turbulence-combustion interaction of these chemical reacting flows will be a new tool that is needed in the design of these future propulsion concepts. Experimental and code development research is being performed at LeRC to better understand chemical reacting flows with the long-term goal of establishing these reliable computer codes. Our approach to understand chemical reacting flows is to look at separate, more simple parts of this complex phenomenon as well as to study the full turbulent reacting flow process. As a result, we are engaged in research on the fluid mechanics associated with chemical reacting flows. We are also studying the chemistry of fuel-air combustion. Finally, we are investigating the phenomenon of turbulence-combustion interaction. Research, both experimental and analytical, is highlighted in each of these three major areas.

  1. Instabilities and Turbulent Flows

    NASA Astrophysics Data System (ADS)

    Oertel, Herbert

    When a viscous fluid flows through long straight tubes at reasonably high speeds, the Hagen-Poiseuille law (4.45), according to which the pressure drop is linearly proportional to the volume of fluid flowing through the pipe, is replaced by another law, in which the pressure drop is significantly greater, and almost proportional to the square of the volume flow rate of fluid. At the same time it is found that the flow field, which is smooth and straight (or laminar) in the Hagen-Poiseuille regime, becomes at higher velocities full of irregular eddying motions (or turbulent). This may be seen clearly in the case of a fluid flowing through glass tubes if a dye is introduced through a small injector at the inlet (Figures 6.1, 4.52). The colored filament is straight and smooth for low speeds but breaks off and disperses almost uniformly when turbulence develops. As a second example, introduced in Chapter 1, consider a jet of water that emerges from a circular orifice into a tank of still water. At very low speeds of the fluid the jet is smooth and steady. For higher speeds, it develops swirls of various sizes amidst avalanches of complexity.

  2. Arsia Mons Surface Flow

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site]

    Today's VIS image of lava flows south of Arsia Mons shows a broad, rough surfaced flow (brighter in image). The brighter flow splits at the bottom and then rejoins again, leaving a window of older flow visible. Note how the flows overlap at the bottom of the image.

    Image information: VIS instrument. Latitude -22.6, Longitude 239.7 East (120.3 West). 17 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  3. Chemical reacting flows

    NASA Technical Reports Server (NTRS)

    Mularz, Edward J.; Sockol, Peter M.

    1990-01-01

    Future aerospace propulsion concepts involve the combustion of liquid or gaseous fuels in a highly turbulent internal airstream. Accurate predictive computer codes which can simulate the fluid mechanics, chemistry, and turbulence-combustion interaction of these chemical reacting flows will be a new tool that is needed in the design of these future propulsion concepts. Experimental and code development research is being performed at LeRC to better understand chemical reacting flows with the long-term goal of establishing these reliable computer codes. Our approach to understand chemical reacting flows is to look at separate, more simple parts of this complex phenomenon as well as to study the full turbulent reacting flow process. As a result, we are engaged in research on the fluid mechanics associated with chemical reacting flows. We are also studying the chemistry of fuel-air combustion. Finally, we are investigating the phenomenon of turbulence-combustion interaction. Research, both experimental and analytical, is highlighted in each of these three major areas.

  4. Chemical reacting flows

    NASA Technical Reports Server (NTRS)

    Mularz, Edward J.; Sockol, Peter M.

    1987-01-01

    Future aerospace propulsion concepts involve the combination of liquid or gaseous fuels in a highly turbulent internal air stream. Accurate predictive computer codes which can simulate the fluid mechanics, chemistry, and turbulence combustion interaction of these chemical reacting flows will be a new tool that is needed in the design of these future propulsion concepts. Experimental and code development research is being performed at Lewis to better understand chemical reacting flows with the long term goal of establishing these reliable computer codes. The approach to understanding chemical reacting flows is to look at separate simple parts of this complex phenomena as well as to study the full turbulent reacting flow process. As a result research on the fluid mechanics associated with chemical reacting flows was initiated. The chemistry of fuel-air combustion is also being studied. Finally, the phenomena of turbulence-combustion interaction is being investigated. This presentation will highlight research, both experimental and analytical, in each of these three major areas.

  5. Hospital free cash flow.

    PubMed

    Kauer, R T; Silvers, J B

    1991-01-01

    Hospital managers may find it difficult to admit their investments have been suboptimal, but such investments often lead to poor returns and less future cash. Inappropriate use of free cash flow produces large transaction costs of exit. The relative efficiency of investor-owned and tax-exempt hospitals in the product market for hospital services is examined as the free cash flow theory is used to explore capital-market conditions of hospitals. Hypotheses concerning the current competitive conditions in the industry are set forth, and the implications of free cash flow for risk, capital-market efficiency, and the cost of capital to tax-exempt institution is compared to capital-market norms.

  6. Microwave fluid flow meter

    DOEpatents

    Billeter, Thomas R.; Philipp, Lee D.; Schemmel, Richard R.

    1976-01-01

    A microwave fluid flow meter is described utilizing two spaced microwave sensors positioned along a fluid flow path. Each sensor includes a microwave cavity having a frequency of resonance dependent upon the static pressure of the fluid at the sensor locations. The resonant response of each cavity with respect to a variation in pressure of the monitored fluid is represented by a corresponding electrical output which can be calibrated into a direct pressure reading. The pressure drop between sensor locations is then correlated as a measure of fluid velocity. In the preferred embodiment the individual sensor cavities are strategically positioned outside the path of fluid flow and are designed to resonate in two distinct frequency modes yielding a measure of temperature as well as pressure. The temperature response can then be used in correcting for pressure responses of the microwave cavity encountered due to temperature fluctuations.

  7. Electrocapturing flow cell

    DOEpatents

    Morozov, Victor [Manassas, VA

    2011-04-05

    A flow cell for electrophoretically-assisted capturing analytes from a flow. The flow cell includes a specimen chamber, a first membrane, a second membrane, a first electrode chamber, and a second electrode chamber. The specimen chamber may have a sample inlet and a sample outlet. A first portion of the first membrane may be coupled to a first portion of the specimen chamber. A first portion of the second membrane may be coupled to a second portion of the specimen chamber. The first electrode chamber may be configured to accept a charge. A portion of the first electrode chamber may be coupled to a second portion of the first membrane. A second electrode chamber may be configured to accept an opposite charge. A portion of the second electrode chamber may be coupled to a second portion of the second membrane.

  8. Microfluidic binary phase flow

    NASA Astrophysics Data System (ADS)

    Angelescu, Dan; Menetrier, Laure; Wong, Joyce; Tabeling, Patrick; Salamitou, Philippe

    2004-03-01

    We present a novel binary phase flow regime where the two phases differ substantially in both their wetting and viscous properties. Optical tracking particles are used in order to investigate the details of such multiphase flow inside capillary channels. We also describe microfluidic filters we have developed, capable of separating the two phases based on capillary pressure. The performance of the filters in separating oil-water emulsions is discussed. Binary phase flow has been previously used in microchannels in applications such as emulsion generation, enhancement of mixing and assembly of custom colloidal paticles. Such microfluidic systems are increasingly used in a number of applications spanning a diverse range of industries, such as biotech, pharmaceuticals and more recently the oil industry.

  9. Rarefied-flow aerodynamics

    NASA Technical Reports Server (NTRS)

    Potter, J. Leith

    1992-01-01

    Means for relatively simple and quick procedures are examined for estimating aerodynamic coefficients of lifting reentry vehicles. The methods developed allow aerospace designers not only to evaluate the aerodynamics of specific shapes but also to optimize shapes under given constraints. The analysis was also studied of the effect of thermomolecular flow on pressures measured by an orifice near the nose of a Space Shuttle Orbiter at altitudes above 75 km. It was shown that pressures corrected for thermomolecular flow effect are in good agreement with values predicted by independent theoretical methods. An incidental product was the insight gained about the free molecular thermal accommodation coefficient applicable under 'real' conditions of high speed flow in the Earth's atmosphere. The results are presented as abstracts of referenced papers. One reference paper is presented in its entirety.

  10. Shaped Recess Flow Control

    NASA Technical Reports Server (NTRS)

    Shyam, Vikram (Inventor); Poinsatte, Philip (Inventor); Thurman, Douglas (Inventor)

    2017-01-01

    One or more embodiments of techniques or systems for shaped recess flow control are provided herein. A shaped recess or cavity can be formed on a surface associated with fluid flow. The shaped recess can be configured to create or induce fluid effects, temperature effects, or shedding effects that interact with a free stream or other structures. The shaped recess can be formed at an angle to a free stream flow and may be substantially "V" shaped. The shaped recess can be coupled with a cooling channel, for example. The shaped recess can be upstream or downstream from a cooling channel and aligned in a variety of manners. Due to the fluid effects, shedding effects, and temperature effects created by a shaped recess, lift-off or separation of cooling jets of cooling channels can be mitigated, thereby enhancing film cooling effectiveness.

  11. Steady Capillary Driven Flow

    NASA Technical Reports Server (NTRS)

    Weislogel, Mark M.

    1996-01-01

    A steady capillary driven flow is developed for a liquid index in a circular tube which is partially coated with a surface modifier to produce a discontinuous wetting condition from one side of the tube to the other. The bulk flow is novel in that it is truly steady, and controlled solely by the physics associated with dynamic wetting. The influence of gravity on the flow is minimized through the use of small diameter tubes approximately O(1 mm) tested horizontally in a laboratory and larger tubes approximately O(10 mm) tested in the low gravity environment of a drop tower. Average steady velocities are predicted and compared against a large experimental data set which includes the effects of tube dimensions and fluid properties. The sensitivity of the velocity to surface cleanliness is dramatic and the advantages of experimentation in a microgravity environment are discussed.

  12. Natural convective mixing flows

    NASA Astrophysics Data System (ADS)

    Ramos, Eduardo; de La Cruz, Luis; del Castillo, Luis

    1998-11-01

    Natural convective mixing flows. Eduardo Ramos and Luis M. de La Cruz, National University of Mexico and Luis Del Castillo San Luis Potosi University. The possibility of mixing a fluid with a natural convective flow is analysed by solving numerically the mass, momentum and energy equations in a cubic container. Two opposite vertical walls of the container are assumed to have temperatures that oscillate as functions of time. The phase of the oscillations is chosen in such a way that alternating corrotating vortices are formed in the cavity. The mixing efficiency of this kind of flow is examined with a Lagrangian tracking technique. This work was partially financed by CONACyT-Mexico project number GE0044

  13. Flux flow microelectronics

    NASA Astrophysics Data System (ADS)

    Martens, J. S.; Hietala, V. M.; Plut, T. A.; Ginley, D. S.; Vawter, G. A.; Tigges, C. P.; Siegal, M. P.; Phillips, J. M.; Hou, S. Y.

    Flux-flow based devices such as the superconducting flux flow transistor and magnetically controlled long junctions have been made from thin films of TlCaBaCuO and YBaCuO. The devices are based on the magnetic control of flux flow in their respective structures: a long junction or an array of weak links. The equivalent circuits of the two devices are similar: a low impedance input control line, an output impedance of 3 - 20 ohm and an active current-controlled element. The long junctions have tended to be slower, have lower gain and be somewhat less noisy than their counterparts. The performance of circuits such as narrowband and distributed amplifiers (50 GHz bandwidths, noise figures less than 3 dB), phase shifters (continuous with less than 2 dB loss 4 - 40 GHz), logic gates (2 - 3 ps gate delays) and memories made using these devices will be compared and analyzed.

  14. Pressure driven particulate flows

    SciTech Connect

    Ingher, M.S.; Mondy, L.A.

    1996-03-01

    Numerical simulations of pressure-driven particulate Stokes flows are performed in cylindrical and rectangular conduits using a parallel boundary element code. Spherical particles are randomly placed in the conduits and a pressure drop between the ends of the conduits is imposed by the boundary conditions to induce a Poiseuille-like flow field. The instantaneous velocities of the particles are then calculated, as well as the additional pressure drop necessary to maintain a constant flow rate. Because the results depend on the spatial distribution of the particles, several random configurations of particles are examined for each case. Depending on two different interpretations of the numerical results, the solid phase can be represented as either leading or lagging the fluid phase. Both of the analyses and interpretations are presented.

  15. Alkaline quinone flow battery.

    PubMed

    Lin, Kaixiang; Chen, Qing; Gerhardt, Michael R; Tong, Liuchuan; Kim, Sang Bok; Eisenach, Louise; Valle, Alvaro W; Hardee, David; Gordon, Roy G; Aziz, Michael J; Marshak, Michael P

    2015-09-25

    Storage of photovoltaic and wind electricity in batteries could solve the mismatch problem between the intermittent supply of these renewable resources and variable demand. Flow batteries permit more economical long-duration discharge than solid-electrode batteries by using liquid electrolytes stored outside of the battery. We report an alkaline flow battery based on redox-active organic molecules that are composed entirely of Earth-abundant elements and are nontoxic, nonflammable, and safe for use in residential and commercial environments. The battery operates efficiently with high power density near room temperature. These results demonstrate the stability and performance of redox-active organic molecules in alkaline flow batteries, potentially enabling cost-effective stationary storage of renewable energy. Copyright © 2015, American Association for the Advancement of Science.

  16. Paraelectric gas flow accelerator

    NASA Technical Reports Server (NTRS)

    Sherman, Daniel M. (Inventor); Wilkinson, Stephen P. (Inventor); Roth, J. Reece (Inventor)

    2001-01-01

    A substrate is configured with first and second sets of electrodes, where the second set of electrodes is positioned asymmetrically between the first set of electrodes. When a RF voltage is applied to the electrodes sufficient to generate a discharge plasma (e.g., a one-atmosphere uniform glow discharge plasma) in the gas adjacent to the substrate, the asymmetry in the electrode configuration results in force being applied to the active species in the plasma and in turn to the neutral background gas. Depending on the relative orientation of the electrodes to the gas, the present invention can be used to accelerate or decelerate the gas. The present invention has many potential applications, including increasing or decreasing aerodynamic drag or turbulence, and controlling the flow of active and/or neutral species for such uses as flow separation, altering heat flow, plasma cleaning, sterilization, deposition, etching, or alteration in wettability, printability, and/or adhesion.

  17. Evaluation of flow hood measurements for residential register flows

    SciTech Connect

    Walker, I.S.; Wray, C.P.; Dickerhoff, D.J.; Sherman, M.H.

    2001-09-01

    Flow measurement at residential registers using flow hoods is becoming more common. These measurements are used to determine if the HVAC system is providing adequate comfort, appropriate flow over heat exchangers and in estimates of system energy losses. These HVAC system performance metrics are determined by using register measurements to find out if individual rooms are getting the correct airflow, and in estimates of total air handler flow and duct air leakage. The work discussed in this paper shows that commercially available flow hoods are poor at measuring flows in residential systems. There is also evidence in this and other studies that flow hoods can have significant errors even when used on the non-residential systems they were originally developed for. The measurement uncertainties arise from poor calibrations and the sensitivity of exiting flow hoods to non-uniformity of flows entering the device. The errors are usually large--on the order of 20% of measured flow, which is unacceptably high for most applications. Active flow hoods that have flow measurement devices that are insensitive to the entering airflow pattern were found to be clearly superior to commercially available flow hoods. In addition, it is clear that current calibration procedures for flow hoods may not take into account any field application problems and a new flow hood measurement standard should be developed to address this issue.

  18. Interactive Flow in Exercise Pedagogy

    ERIC Educational Resources Information Center

    Lloyd, Rebecca; Smith, Stephen

    2006-01-01

    A phenomenology of the bodily experience of interactive flow adds to Csikszentmihalyi's flow theory. Whereas Csikszentmihalyi attended to teachers' and students' experiences of flow separately, this inquiry explores flow through three water-inspired layers of physical interaction between fitness professionals and their clients. Teaching fitness is…

  19. Interactive Flow in Exercise Pedagogy

    ERIC Educational Resources Information Center

    Lloyd, Rebecca; Smith, Stephen

    2006-01-01

    A phenomenology of the bodily experience of interactive flow adds to Csikszentmihalyi's flow theory. Whereas Csikszentmihalyi attended to teachers' and students' experiences of flow separately, this inquiry explores flow through three water-inspired layers of physical interaction between fitness professionals and their clients. Teaching fitness is…

  20. Flow visualization in fluid mechanics

    NASA Astrophysics Data System (ADS)

    Freymuth, Peter

    1993-01-01

    The history of flow visualization is reviewed and basic methods are examined. A classification of the field of physical flow visualization is presented. The introduction of major methods is discussed and discoveries made using flow visualization are reviewed. Attention is given to limitations and problem areas in the visual evaluation of velocity and vorticity fields and future applications for flow visualization are suggested.

  1. Flow transition behavior between the film flow and rivulet flow on an inclined wall

    NASA Astrophysics Data System (ADS)

    Iso, Yoshiyuki; Chen, Xi

    2010-11-01

    Gas-liquid two-phase flows on the wall like liquid film flows, which are the so-called wetted wall flows, are observed in many industrial processes such as absorption, desorption, distillation and others. For the optimum design of packed columns widely used in those kind of processes, the accurate predictions of the wetted wall flow behavior in packing elements are important, especially in order to enhance the mass transfer between the gas and liquid and to prevent flooding and channeling of the liquid flow. The present study focused on the effects of the change of liquid flow rate and the wall surface texture treatments on the characteristics of wetted wall flows which have the drastic flow transition between the film flow and rivulet flow. In this paper, gas-liquid two-phase flow simulation by using the volume of fluid (VOF) model is applied into wetted wall flows. Firstly, present results showed that the hysteresis of the flow transition between the film flow and rivulet flow arose against the increasing or decreasing stages of the liquid flow rate. It was supposed that this transition phenomenon depends on the history of flow pattern as the change of curvature of interphase surface which leads to the surface tension. Secondary, the present simulations showed that surface texture treatments added on the wall can improve the prevention of liquid channeling and can increase the wetted area.

  2. Coagulation in chaotic flows

    SciTech Connect

    Muzzio, F.J.; Ottino, J.M.

    1988-09-01

    We study coagulation in the flow field of a time-periodic deterministic chaotic flow and focus on the simplest case: point particles convected without diffusion and allowed to coagulate with probability 1 when the distance is less than d. An analysis of the underlying physics is presented. Under ''well-mixed'' conditions the system behaves as if the particles were moved by Brownian motion, and a simple kinetic model describes the main results. The poorly mixed case is considerably more complex. Spatial inhomogeneities result from competition between the rate of coagulation and mixing, and trapping and leaking of clusters due to Kolmogorov-Arnold-Moser surfaces.

  3. Flow Analysis Software Toolkit

    NASA Technical Reports Server (NTRS)

    Watson, Velvin; Castagnera, Karen; Plessel, Todd; Merritt, Fergus; Kelaita, Paul; West, John; Sandstrom, Tim; Clucas, Jean; Globus, AL; Bancroft, Gordon; hide

    1993-01-01

    Flow Analysis Software Toolkit (FAST) computer program provides software environment facilitating visualization of data. Collection of separate programs (modules) running simultaneously and helps user to examine results of numerical and experimental simulations. Intended for graphical depiction of computed flows, also assists in analysis of other types of data. Combines capabilities of such programs as PLOT3D, RIP, SURF, and GAS into one software environment with modules sharing data. All modules have consistent, highly interactive graphical user interface. Modular construction makes it flexible and extensible. Environment custom-configured, and new modules developed and added as needed. Written in ANSI compliant FORTRAN 77 and C language.

  4. IGS Data Flow

    NASA Technical Reports Server (NTRS)

    Noll, Carey

    2006-01-01

    The IGS analysis centers and user community in general need to be assured that the data centers archive a consistent set of files. Changes to the archives can occur because of the re-publishing of data, the transmission of historic data, and the resulting re-distribution (or lack thereof) of these data from data center to data center. To ensure the quality of the archives, a defined data flow and method of archive population needs to be established. This poster will diagram and review the current IGS data flow, discuss problems that have occurred, and provide recommendations for improvement.

  5. Flow line sampler

    DOEpatents

    Nicholls, Colin I.

    1992-07-14

    An on-line product sampling apparatus and method for measuring product samples from a product stream (12) in a flow line (14) having a sampling aperture (11), includes a sampling tube (18) for containing product samples removed from flow line (14). A piston (22) removes product samples from the product stream (12) through the sampling aperture (11) and returns samples to product stream (12). A sensor (20) communicates with sample tube (18), and senses physical properties of samples while the samples are within sample tube (18). In one embodiment, sensor (20) comprises a hydrogen transient nuclear magnetic resonance sensor for measuring physical properties of hydrogen molecules.

  6. Von Karman swirling flows

    NASA Astrophysics Data System (ADS)

    Zandbergen, P. J.; Dijkstra, D.

    A development history is presented for research on the problem of swirling flow infinite disks from its formulation by von Karman in 1921 through the treatments of Batchelor (1951) and Stewartson (1953) to the present, with a view to both its one-disk and two-disk forms. Attention is given to the stability of the stationary solutions for these problems, and to the case where the radii of the disks are finite. The question as to the extent to which the Karman swirling flow occurs in a finite radial geometry is noted to be of fundamental importance.

  7. History of fracture flow

    NASA Astrophysics Data System (ADS)

    Wang, Herbert F.; Doe, Thomas W.

    1990-09-01

    The Committee on the History and Heritage of Hydrology sponsored this special session at the 1990 AGU Spring Meeting, held in Baltimore, Md. The history of fracture flow was an appropriate conclusion to 2 days of papers on the geologic characterization of media heterogeneity. Fracture flow theory developed from several technical disciplines, including rock mechanics and geological engineering in addition to hydrogeology. In particular, the 1960s and 1970s saw major advances in methods for describing and analyzing discontinuous geologic features. Institutions such as the University of California, Berkeley, which had strong interdisciplinary groups in the fields mentioned above, spearheaded much of the technical development.

  8. Flow energizers. Task A

    NASA Technical Reports Server (NTRS)

    Ward, D.; Binford, R.; Vonlavante, E.; Paul, B.

    1985-01-01

    The effects of a propeller slipstream on the wing laminar boundary are being investigated. Hot-wire velocity sensor measurements have been performed in flight and in a wind tunnel. It is shown that the boundary layer cycles between a laminar state and a turbulent state at the propeller blade passage rate. The cyclic length of the turbulent state increases with decreasing laminar stability. Analyses of the time-varying velocity profiles show the turbulent state to lie in a transition region between fully laminar and fully turbulent. The observed cyclic boundary layer has characteristics similar to relaminarizing flow and laminar flow with external turbulence.

  9. Systematic review and meta-analysis of flow cytometry in urinary tract infection screening.

    PubMed

    Shang, Yan-Jun; Wang, Qian-Qian; Zhang, Jian-Rong; Xu, Yu-Lian; Zhang, Wei-Wei; Chen, Yan; Gu, Ming-Li; Hu, Zhi-De; Deng, An-Mei

    2013-09-23

    Automated urine sediment analysis of white blood cells (WBCs) and bacteria is a promising approach for urinary tract infections (UTIs) screening. However, available data on their screening efficacy is inconsistent. English articles from Pubmed, EMBASE, and Web of Science published before December 1, 2012 were analyzed. The Quality Assessment for Studies of Diagnostic Accuracy (QUADAS) tool was used to evaluate the quality of eligible studies. Performance characteristics of WBCs and bacteria (sensitivity, specificity, and other measures of accuracy) were pooled and examined by random-effects models. Nineteen studies containing 22,305 samples were included. Pooled sensitivities were 0.87 (95% confidence interval [CI], 0.86-0.89) for WBCs and 0.92 (95% CI, 0.91-0.93) for bacteria. Corresponding pooled specificities were 0.67 (95% CI, 0.66-0.68) for WBCs and 0.60 (95% CI, 0.59-0.61) for bacteria. Areas under the summary receiver operating characteristics curves were 0.87 and 0.93 for WBCs and bacteria, respectively. The major limitation of eligible studies was that enrolled subjects were often not representative of clinical patient populations in which UTI would be suspected. WBC and bacterial measurements by the UF-100 and UF-1000i are useful indicators in UTI screening; however, the performances of these systems should be rigorously evaluated by additional studies. Copyright © 2013 Elsevier B.V. All rights reserved.

  10. Siphon flows in isolated magnetic flux tubes. II - Adiabatic flows

    NASA Technical Reports Server (NTRS)

    Montesinos, Benjamin; Thomas, John H.

    1989-01-01

    This paper extends the study of steady siphon flows in isolated magnetic flux tubes surrounded by field-free gas to the case of adiabatic flows. The basic equations governing steady adiabatic siphon flows in a thin, isolated magnetic flux tube are summarized, and qualitative features of adiabatic flows in elevated, arched flux tubes are discussed. The equations are then cast in nondimensional form and the results of numerical computations of adiabatic siphon flows in arched flux tubes are presented along with comparisons between isothermal and adiabatic flows. The effects of making the interior of the flux tube hotter or colder than the surrounding atmosphere at the upstream footpoint of the arch is considered. In this case, is it found that the adiabatic flows are qualitatively similar to the isothermal flows, with adiabatic cooling producing quantitative differences. Critical flows can produce a bulge point in the rising part of the arch and a concentration of magnetic flux above the bulge point.

  11. Flow cytometry apparatus

    DOEpatents

    Pinkel, Daniel

    1991-01-01

    An obstruction across the flow chamber creates a one dimensional convergence of a sheath fluid. A passageway in the construction directs flat cells near to the area of one dimensional convergence in the sheath fluid to provide proper orientation of flat cells at fast rates.

  12. Surface Erosion and Flow

    NASA Image and Video Library

    2003-04-09

    The mottled surface texture and flow features observed in this NASA Mars Odyssey image suggest materials may be, or have been, mixed with ice. There is also evidence in some areas for infilling of sediments as crater rims and ridges appear covered.

  13. Alba Mons Flows

    NASA Image and Video Library

    2014-03-19

    This image from NASA 2001 Mars Odyssey spacecraft shows a small portion of the lava flows from Alba Mons. The depression and collapse features within it are part of the large system of tectonic features created by the apparent collapse of the volcano.

  14. Faults and Flows

    NASA Image and Video Library

    2014-10-20

    Lava flows of Daedalia Planum can be seen at the top and bottom portions of this image from NASA 2001 Mars Odyssey spacecraft. The ridge and linear depression in the central part of the image are part of Mangala Fossa, a fault bounded graben.

  15. Modeling and flow theory

    SciTech Connect

    Not Available

    1981-10-01

    (1) We recommend the establishment of an experimental test facility, appropriately instrumented, dedicated to research on theoretical modeling concepts. Validation of models for the various flow regimes, and establishment of the limitations or concepts used in the construction of models, are sorely needed areas of research. There exists no mechanism currently for funding of such research on a systematic basis. Such a facility would provide information fundamental to progress in the physics of turbulent multi-phase flow, which would also have impact on the understanding of coal utilization processes; (2) combustion research appears to have special institutional barriers to information exchange because it is an established, commercial ongoing effort, with heavy reliance on empirical data for proprietary configurations; (3) for both gasification and combustion reactors, current models appear to handle adequately some, perhaps even most, gross aspects of the reactors such as overall efficiency and major chemical output constituents. However, new and more stringent requirements concerning NOX, SOX and POX (small paticulate) production require greater understanding of process details and spatial inhomogenities, hence refinement of current models to include some greater detail is necessary; (4) further progress in the theory of single-phase turbulent flow would benefit our understanding of both combustors and gasifiers; and (5) another area in which theoretical development would be extremely useful is multi-phase flow.

  16. Social Studies Flow Chart.

    ERIC Educational Resources Information Center

    New York State Education Dept., Albany. Bureau of General Education Curriculum Development.

    The flow chart outlines the division of content within social studies courses for each grade (K-12) in New York State public schools. It is strictly an outline of content; it does not reflect emphasis on concept development or use of the inductive mode which are stressed in state teacher's guides. In kindergarten and grade one, social studies…

  17. Muddy Ejecta Flow

    NASA Image and Video Library

    2017-01-10

    This small 2 kilometer-wide crater was sitting around, minding its own business when a meteoroid struck the ground just to the west and created a new, larger crater almost 10 kilometers in diameter (not pictured). The ejecta spraying out of the new crater landed back on the ground and then continued to flow away from the new crater, and the smaller crater was in the way of that muddy flow. You can see where much of the muddy material flowed around the crater's uplifted rim and forms a squiggly ridge, but you can also see where the mud flow slid over the rim and ponded down in the bottom of the crater. One question we don't know the answer to is: "how wet was the muddy ejecta?" Ongoing observations like this and laboratory-based experiments are trying to find the answer to that question. This image also illustrates a common theme in geology, namely, the law of superposition. Because the crater has been affected by ejecta from the larger crater to the west, the small crater had to be there first and then the second, larger crater and its ejecta had to form. This allows planetary geologists to decipher the relative ages of different landforms. Because a central goal of geology is to understand past events from present-day clues, geology is sometimes compared to forensic science. http://photojournal.jpl.nasa.gov/catalog/PIA13181

  18. Sinuous flow in metals

    PubMed Central

    Yeung, Ho; Viswanathan, Koushik; Compton, Walter Dale; Chandrasekar, Srinivasan

    2015-01-01

    Annealed metals are surprisingly difficult to cut, involving high forces and an unusually thick “chip.” This anomaly has long been explained, based on ex situ observations, using a model of smooth plastic flow with uniform shear to describe material removal by chip formation. Here we show that this phenomenon is actually the result of a fundamentally different collective deformation mode—sinuous flow. Using in situ imaging, we find that chip formation occurs via large-amplitude folding, triggered by surface undulations of a characteristic size. The resulting fold patterns resemble those observed in geophysics and complex fluids. Our observations establish sinuous flow as another mesoscopic deformation mode, alongside mechanisms such as kinking and shear banding. Additionally, by suppressing the triggering surface undulations, sinuous flow can be eliminated, resulting in a drastic reduction of cutting forces. We demonstrate this suppression quite simply by the application of common marking ink on the free surface of the workpiece material before the cutting. Alternatively, prehardening a thin surface layer of the workpiece material shows similar results. Besides obvious implications to industrial machining and surface generation processes, our results also help unify a number of disparate observations in the cutting of metals, including the so-called Rehbinder effect. PMID:26216980

  19. Infinitesimal Conical Supersonic Flow

    NASA Technical Reports Server (NTRS)

    Busemann, Adolf

    1947-01-01

    The calculation of infinitesimal conical supersonic flow has been applied first to the simplest examples that have also been calculated in another way. Except for the discovery of a miscalculation in an older report, there was found the expected conformity. The new method of calculation is limited more definitely to the conical case.

  20. Duct Flow Control System.

    DTIC Science & Technology

    is ejected under pressure tangentially of local duct surfaces through Coanda affected slots at the trailing edge of the duct from which only the...channel passages in order to modify the flow stream through the duct so as to perform certain functions such as thrust control and steerage control effects enhancing vehicle maneuverability.

  1. Wet solids flow enhancement

    SciTech Connect

    Caram, H.S.; Agrawal, D.K.; Foster, N.

    1997-07-01

    The objective was to visualize the flow of granular materials in the silo using Nuclear Magnetic Resonance. This was done by introducing traces. Mustard seeds and poppy seeds were used as trace particles. The region sampled was a cylinder 25 mm in diameter and 40 mm in length. Eight slices containing 128 by 128 to 256 by 256 pixels were generated for each image.

  2. US energy flow, 1991

    SciTech Connect

    Borg, I.Y.; Briggs, C.K.

    1992-06-01

    Trends in energy consumption and assessment of energy sources are discussed. Specific topics discussed include: energy flow charts; comparison of energy use with 1990 and earlier years; supply and demand of fossil fuels (oils, natural gas, coal); electrical supply and demand; and nuclear power.

  3. Materials Flow and Sustainability

    USGS Publications Warehouse

    Sznopek, John L.; Brown, William M.

    1998-01-01

    Materials extracted from the Earth are necessary to produce our most fundamental needs – food, clothing, and shelter. Materials are needed to maintain and improve our standard of living. Understanding the whole system of materials flow, from source to ultimate disposition, can help us better manage the use of natural resources and protect the environment.

  4. Visualization of relaminarizing flows

    NASA Technical Reports Server (NTRS)

    Viswanath, P. R.; Narasimha, R.; Prabhu, A.

    1978-01-01

    The experiments described in the present paper provided conclusive evidence for the feasibility of achieving reverse transition by several different mechanisms. Turbulent-to-laminar transition in water was visualized by injection of purple and green dyes. Air flows were visualized by colored schlieren photography.

  5. Flow cytometry apparatus

    DOEpatents

    Pinkel, D.

    1987-11-30

    An obstruction across the flow chamber creates a one-dimensional convergence of a sheath fluid. A passageway in the obstruction directs flat cells near to the area of one-dimensional convergence in the sheath fluid to provide proper orientation of flat cells at fast rates. 6 figs.

  6. KP flows and quantization

    NASA Astrophysics Data System (ADS)

    Luu, Martin T.

    2016-12-01

    The quantization of a pair of commuting differential operators is a pair of non-commuting differential operators. Both at the classical and quantum levels, the flows of the Kadomtsev-Petviashvili (KP) hierarchy are defined and further one can consider switching, up to a sign, the ordering of the operators. We discuss the interaction of these operations with the quantization.

  7. Sinuous flow in metals.

    PubMed

    Yeung, Ho; Viswanathan, Koushik; Compton, Walter Dale; Chandrasekar, Srinivasan

    2015-08-11

    Annealed metals are surprisingly difficult to cut, involving high forces and an unusually thick "chip." This anomaly has long been explained, based on ex situ observations, using a model of smooth plastic flow with uniform shear to describe material removal by chip formation. Here we show that this phenomenon is actually the result of a fundamentally different collective deformation mode--sinuous flow. Using in situ imaging, we find that chip formation occurs via large-amplitude folding, triggered by surface undulations of a characteristic size. The resulting fold patterns resemble those observed in geophysics and complex fluids. Our observations establish sinuous flow as another mesoscopic deformation mode, alongside mechanisms such as kinking and shear banding. Additionally, by suppressing the triggering surface undulations, sinuous flow can be eliminated, resulting in a drastic reduction of cutting forces. We demonstrate this suppression quite simply by the application of common marking ink on the free surface of the workpiece material before the cutting. Alternatively, prehardening a thin surface layer of the workpiece material shows similar results. Besides obvious implications to industrial machining and surface generation processes, our results also help unify a number of disparate observations in the cutting of metals, including the so-called Rehbinder effect.

  8. More on Cotton flow

    NASA Astrophysics Data System (ADS)

    Kilicarslan, Ercan; Dengiz, Suat; Tekin, Bayram

    2015-06-01

    Cotton flow tends to evolve a given initial metric on a three manifold to a conformally flat one. Here we expound upon the earlier work on Cotton flow and study the linearized version of it around a generic initial metric by employing a modified form of the DeTurck trick. We show that the flow around the flat space, as a critical point, reduces to an anisotropic generalization of linearized KdV equation with complex dispersion relations one of which is an unstable mode, rendering the flat space unstable under small perturbations. We also show that Einstein spaces and some conformally flat non-Einstein spaces are linearly unstable. We refine the gradient flow formalism and compute the second variation of the entropy and show that generic critical points are extended Cotton solitons. We study some properties of these solutions and find a Topologically Massive soliton that is built from Cotton and Ricci solitons. In the Lorentzian signature, we also show that the pp-wave metrics are both Cotton and Ricci solitons.

  9. Quaternions and ideal flows

    NASA Astrophysics Data System (ADS)

    Eshraghi, H.; Gibbon, J. D.

    2008-08-01

    After a review of some of the recent works by Holm and Gibbon on quaternions and their application to Lagrangian flows, particularly the incompressible Euler equations and the equations of ideal MHD, this paper investigates the compressible and relativistic Euler equations using these methods.

  10. Epiglottal Flow Physics

    NASA Astrophysics Data System (ADS)

    Pollard, Andrew; Shinneeb, Abdul-Monsif

    2011-11-01

    PIV measurements have been made at three locations in the pharynx/larynx region in the ETA model, one along the central sagittal plane and two cross-sectional planes. The measurements were made at a flow rate of 9.04 l/min which corresponds approximately to 10 l/min in the prototype. The corresponding Reynolds number Re based on the inlet condition is 716. Two thousand images were acquired at each location at a framing rate of 2 Hz. The mean velocity fields were then calculated. In addition,the data was analysed by the proper orthogonal decomposition (POD) technique to expose vortical structures. Only few modes were used for the POD reconstruction which recovered about 60% of the turbulent kinetic energy. The results showed that the flow is characterised by regions of re-circulation, jet-like, and sink-like flows. In addition, the POD-reconstructed fields revealed some interesting features that occur in the human pharynx/larynx region near the epiglottis such as tearing and pairing processes, as well as the interaction between the flows induced by the structures. Funded by NSERC.

  11. Sonic flow distortion experiment

    NASA Astrophysics Data System (ADS)

    Peters, Gerhard; Kirtzel, Hans-Jürgen; Radke, Jürgen

    2017-04-01

    We will present results from a field experiment with multiple sonic anemometers, and will address the question about residual errors of wind tunnel based calibrations that are transferred to atmospheric measurements. Ultrasonic anemometers have become standard components of high quality in-situ instrumentations, because of the long term calibration stability, fast response, wide dynamic range, and various options of built in quality control. On the downside of this technology is the fact that the sound transducers and the carrying structure represent obstacles in the flow causing systematic deviations of the measured flow from the free flow. Usually, the correction schemes are based on wind tunnel observations of the sonic-response as function of angle of attack under stationary conditions. Since the natural atmospheric flow shows turbulence intensities and scales, which cannot be mimicked in a wind tunnel, it is suspected that the wind-tunnel based corrections may be not (fully) applicable to field data. The wide spread use of sonic anemometers in eddy flux instrumentations for example in the frame of EuroFlux, AmeriFlux or other international observation programs has therefore prompted a - still controversial - discussion of the significance of residual flow errors. In an attempt to quantify the flow distortion in free field conditions, 12 identical 3-component sonics with 120 degree head symmetry were operated at the north margin of an abandoned airfield. The sonics were installed in a straight line in WE-direction at 2.6 m height with a mutual distance of 3 meters and with an azimuth increment of the individual sonics of 11 degrees. Synchronous raw data were recorded with 20 Hz sample rate. Data of about 12 hours with southerly winds (from the relatively flat airfield) were analyzed. Statistical homogeneity of the wind field in the range of the instruments line was assumed, but a variable finite turbulent decay constant was accounted for, which was estimated

  12. Enceladus' Enigmatic Heat Flow

    NASA Astrophysics Data System (ADS)

    Howett, C.; Spencer, J. R.; Spencer, D.; Verbiscer, A.; Hurford, T.; Segura, M.

    2013-12-01

    Accurate knowledge of Enceladus' heat flow is important because it provides a vital constraint on Enceladus' tidal dissipation mechanisms, orbital evolution, and the physical processes that generate the plumes. In 2011 we published an estimate of the current heat flow from Enceladus' active south polar terrain: 15.8 +/- 3.1 GW (Howett et al., 2011). This value was calculated by first estimating by modeling, and then removing, the passive component from 17 to 1000 micron observations made of the entire south polar terrain by Cassini's Composite Infrared Spectrometer (CIRS). The heat flow was then directly calculated from the residual, assumed endogenic, component. The derived heat flow of 15.8 GW was surprisingly high, about 10 times greater than that predicted by steady-state tidal heating (Meyer and Wisdom, 2007). CIRS has also returned high spatial resolution observations of Enceladus' active south polar terrain. Two separate observations are used: 9 to 16 micron observations taken over nearly the complete south polar terrain and a single 17 to 1000 micron scan over Damascus, Baghdad and Cairo. The shorter wavelength observations are only sensitive to high temperature emission (>70 K), and so longer wavelength observations are required (despite their limited spatial coverage) to estimate the low temperature emission from the stripes. Analysis of these higher resolution observations tells a different story of Enceladus' endogenic heat flow: the preliminary estimate of the heat flow from the active tiger stripes using these observations is 4.2 GW. An additional 0.5 GW must be added to this number to account for the latent heat release by the plumes (Ingersoll and Pankine 2009), giving a total preliminary estimate of 4.9 GW. The discrepancy in these two numbers is significant and we are currently investigating the cause. One possible reason is that there is significantly higher endogenic emission from the regions between the tiger stripes than we currently estimate

  13. Ultrasensitive flow cytometric analyses

    SciTech Connect

    Jett, J.H.; Cram, L.S.; Keller, R.A.; Martin, J.C.; Saunders, G.C.; Sklar, L.A.; Steinkamp, J.A.

    1993-01-01

    New techniques and approaches to cellular analysis being developed at the Los Alamos National Flow Cytometry Resource can be divided into those that improve sensitivity and those that move the technology into new areas by refining existing approaches. An example of the first category is a flow cytometric system capable of measuring the phase shift of fluorescence emitted by fluorophors bound to cells is being assembled. This phase sensitive cytometer is be capable of quantifying fluorescence life time on a cell-by-cell basis as well as using the phase sensitive detection to separate fluorescence emissions that overlap spectrally but have different lifetimes. A Fourier transform flow cytometer capable of measuring the fluorescence emission spectrum of individual labeled cells at rates approaching several hundred per second is also in the new technology category. The current implementation is capable of resolving the visible region of the spectrum into 8 bands. With this instrument, it is possible to resolve the contributions of fluorophors with overlapping emission spectra and to determine the emission spectra of dyes such as calcium concentration indicators that are sensitive to the physiological environment. Flow cytometric techniques have been refined to the point that it is possible to detect individual fluorescent molecules in solution as they flow past a laser beam. This capability has lead to a rapid DNA sequencing project. The goal of the project is to develop a technique that is capable of sequencing long strands of DNA (40,000 kb) at a rate of between 100 and 1,000 bases per second.

  14. Physics of Traffic Flow

    NASA Astrophysics Data System (ADS)

    Davis, L. C.

    2015-03-01

    The Texas A&M Transportation Institute estimated that traffic congestion cost the United States 121 billion in 2011 (the latest data available). The cost is due to wasted time and fuel. In addition to accidents and road construction, factors contributing to congestion include large demand, instability of high-density free flow and selfish behavior of drivers, which produces self-organized traffic bottlenecks. Extensive data collected on instrumented highways in various countries have led to a better understanding of traffic dynamics. From these measurements, Boris Kerner and colleagues developed a new theory called three-phase theory. They identified three major phases of flow observed in the data: free flow, synchronous flow and wide moving jams. The intermediate phase is called synchronous because vehicles in different lanes tend to have similar velocities. This congested phase, characterized by lower velocities yet modestly high throughput, frequently occurs near on-ramps and lane reductions. At present there are only two widely used methods of congestion mitigation: ramp metering and the display of current travel-time information to drivers. To find more effective methods to reduce congestion, researchers perform large-scale simulations using models based on the new theories. An algorithm has been proposed to realize Wardrop equilibria with real-time route information. Such equilibria have equal travel time on alternative routes between a given origin and destination. An active area of current research is the dynamics of connected vehicles, which communicate wirelessly with other vehicles and the surrounding infrastructure. These systems show great promise for improving traffic flow and safety.

  15. Elastic Granular Flows

    NASA Astrophysics Data System (ADS)

    Campbell, C. S.

    2014-12-01

    The dry granular flowmap can be broken into two broad categories, the Elastic and the Inertial. Elastic flows are dominated by force chains and stresses are generated by the compression of the interparticle contacts within those chains, and thus are proportional to the stiffness of the contacts. The Elastic zone can be subdivided into two regimes, the Elastic-Quasistatic where forces are independent of the shear rate which at high shear rates transitions to Elastic-Inertial where the particle inertia is reflected in the forces and the stresses increase linearly with the shear rate. In the Inertial regime, the stresses vary with the square of the shear rate. It also is divided into two regimes, the Dense-Inertial where the flow is dominated by clusters of particles, and the Inertial-Collisional where the flow is dominated by binary collisions. Appropriately the elastic theory grew out of an old study of landslides. But like most such studies, all of the above depend on idealized computer simulations of uniform sized spherical particles. Real particles are never round, never of uniform size, and the process of flowing changes surface properties and may even shatter the particles. But all indications are that real systems still fit into the pattern drawn out in the last paragraph. A grave problem facing the field is how to incorporate these effects without losing a fundamental understanding of the internal rheological processes. This talk will begin with an overview of the Elastic flowmap and the behaviors associated with each flow regime. It will then discuss early work to include effects of particle shape and size mixtures and perhaps some effects of particle breakage.

  16. Numerical Analysis for the Air Flow of Cross Flow Fan

    NASA Astrophysics Data System (ADS)

    Sakai, Hirokazu; Tokushge, Satoshi; Ishikawa, Masatoshi; Ishihara, Takuya

    There are many factors for designing the cross flow fan. Therefore, the performance of cross flow fan is not clear yet. We can analyze the transient flow of a cross flow fan using sliding mesh approach. One of the tasks using Computational Fluid Dynamics (CFD) is a way of modeling for analysis heat exchangers with cross flow fan. These tasks are very important for design. The paper has a modeling of heat exchangers and meshing the fan blades. The next tasks, we focus the ability of cross flow fan when we change the geometry of fan blades.

  17. Visualization study of flow in axial flow inducer.

    NASA Technical Reports Server (NTRS)

    Lakshminarayana, B.

    1972-01-01

    A visualization study of the flow through a three ft dia model of a four bladed inducer, which is operated in air at a flow coefficient of 0.065, is reported in this paper. The flow near the blade surfaces, inside the rotating passages, downstream and upstream of the inducer is visualized by means of smoke, tufts, ammonia filament, and lampblack techniques. Flow is found to be highly three dimensional, with appreciable radial velocity throughout the entire passage. The secondary flows observed near the hub and annulus walls agree with qualitative predictions obtained from the inviscid secondary flow theory.

  18. Flow Split of Churn Flow at a Vertical Impacting T,

    DTIC Science & Technology

    1986-11-01

    Barnea, D. and Dukler , A.E. (980). "Modelling flow pattern .transitions for steady upwards gas liquid flow in vertical tubes", (AIChE Journal Vol. 26...churn flow at a vertical impacting T DTIC 4 ELECTE B J Azzopardi, A Purvis and A H Govan JAU I1MD COPYRIGHT ANO REPRODUCTION fn lies about copyriqht ant...FLOW SPLIT OF CHURN FLOW AT A VERTICAL IMPACTING T B. J. Azzopardi, A. Purvi:’ and A. H. Govan ABSTRACT Measurements have been made of the flow split

  19. Secondary flows in slow granular flows

    NASA Astrophysics Data System (ADS)

    Dsouza, Peter Varun; Krishnaraj, K. P.; Nott, Prabhu R.

    2017-06-01

    Recent findings by Krishnaraj and Nott [1] show that a granular material sheared in a cylindrical Couette cell at low shear rates forms a single secondary vortex. The vortex spans the entire width of the Couette cell and has a sense opposite to the centrifugally driven Taylor-Couette vortex in a Newtonian fluid - it is in fact shown to be driven by shear-induced dilation. Krishnaraj and Nott [1] show that the vortex also explains a Theological anomaly observed earlier [2], wherein all components of the stress on the outer cylinder increase nearly exponentially with depth from the free surface. In this study, we test the robustness of this vortex by varying the parameters of the grain contact model. We show that the presence of a free surface is not essential for the formation of the secondary vortex. The vortex forms even when a rigid plate of finite weight confines the granular column at the top. We find that as the shear rate is increased, an additional centrifugally-driven vortex appears. This new vortex keeps growing until, at Savage number close to one, the dilation-driven vortex disappears. We also present the variation of the wall stresses at the inner cylinder with depth. Finally, we argue that the secondary flow can also help to understand the rheological behaviour observed in geometries such as the split-bottom Couette device [3].

  20. Using flow feature to extract pulsatile blood flow from 4D flow MRI images

    NASA Astrophysics Data System (ADS)

    Wang, Zhiqiang; Zhao, Ye; Yu, Whitney; Chen, Xi; Lin, Chen; Kralik, Stephen F.; Hutchins, Gary D.

    2017-02-01

    4D flow MRI images make it possible to measure pulsatile blood flow inside deforming vessel, which is critical in accurate blood flow visualization, simulation, and evaluation. Such data has great potential to overcome problems in existing work, which usually does not reflect the dynamic nature of elastic vessels and blood flows in cardiac cycles. However, the 4D flow MRI data is often low-resolution and with strong noise. Due to these challenges, few efforts have been successfully conducted to extract dynamic blood flow fields and deforming artery over cardiac cycles, especially for small artery like carotid. In this paper, a robust flow feature, particularly the mean flow intensity is used to segment blood flow regions inside vessels from 4D flow MRI images in whole cardiac cycle. To estimate this flow feature more accurately, adaptive weights are added to the raw velocity vectors based on the noise strength of MRI imaging. Then, based on this feature, target arteries are tracked in at different time steps in a cardiac cycle. This method is applied to the clinical 4D flow MRI data in neck area. Dynamic vessel walls and blood flows are effectively generated in a cardiac cycle in the relatively small carotid arteries. Good image segmentation results on 2D slices are presented, together with the visualization of 3D arteries and blood flows. Evaluation of the method was performed by clinical doctors and by checking flow volume rates in the vertebral and carotid arteries.

  1. How to use your peak flow meter

    MedlinePlus

    Peak flow meter - how to use; Asthma - peak flow meter; Reactive airway disease - peak flow meter; Bronchial asthma - peak flow meter ... your airways are narrowed and blocked due to asthma, your peak flow values drop. You can check ...

  2. Low flow vortex shedding flowmeter

    NASA Technical Reports Server (NTRS)

    Waugaman, Charles J.

    1989-01-01

    The purpose was to continue a development project on a no moving parts vortex shedding flowmeter used for flow measurement of hypergols. The project involved the design and construction of a test loop to evaluate the meter for flow of Freon which simulates the hypergol fluids. Results were obtained on the output frequency characteristics of the flow meter as a function of flow rate. A family of flow meters for larger size lines and ranges of flow was sized based on the results of the tested meter.

  3. Flow equation for porous plug and capillary tube flow restrictors

    NASA Technical Reports Server (NTRS)

    Davis, W. S.

    1972-01-01

    Development of flow measuring apparatus for determining low flow performance of resistojet thruster is discussed. Diagram of test equipment is presented. Operation of test equipment is described and numerical relationships are explained.

  4. Transition in Turbine Flows

    NASA Technical Reports Server (NTRS)

    Herbert, Thorwald

    1998-01-01

    We have further developed our capabilities to analyze transition in turbine boundary layers from first principles by integrating the nonlinear parabolized stability equations (PSE) with improved initial and boundary conditions. With modified iteration schemes, we are able to proceed deeper into the transition region where skin friction coefficient and heat transfer coefficient significantly increase. Initial and boundary conditions at elevated turbulence levels can be derived by receptivity analysis. Test runs for ERCOFTAC test case T3A at 2.4\\% turbulence level provide results in good agreement with the experimental data. The sharper minimum of the skin coefficient also shown by DNS results is likely due to the missing intermittency. The method has been applied to various experimentally studied turbine blades (UTRC, VKI, Zierke, Langston, Hippensteele, and others). The PSE results, though physically reasonable, do not agree as well as expected with the experimental findings. We have, therefore, performed an extensive search for the reasons of the seemingly systematic deviations. A first source of uncertainty has been found in the often insufficient documentation of the experiments (e.g. on blockage by end-wall boundary layers). However, variation of the relevant parameters does not lead to more satisfactory agreement. A second reason has been found in the "standard procedure" which considers a 2D flow at midspan and uses a panel code and subsequent boundary-layer code to obtain the laminar basic flow for the transition analysis. Comparison with the pressure distribution obtained with a 3D design code (RVC3D) shows significant three-dimensionality of the flow (e.g. in the UTRC experiments). The spanwise variation has been neglected in our original PSE code. To overcome this problem, we have developed the PSE/3D for fully 3D boundary layers to account for streamwise and spanwise variations. Since the design code does not provide the boundary-layer flow with

  5. Wet solids flow enhancemant

    SciTech Connect

    Caram, H.S.; Foster, N.; Wildman, D.J.

    1996-12-31

    WE used glass beads of different sizes as.a model system to study the flow enhancing properties of Octadecyltrichlorosilane (OTS). 0TS provides Si(CH{sub 2}){sub 17}CH{sub 3} groups that bind with the surface hydrox groups to make it hydrophobic. Experimental data showed, indeed, that surface hydrophobicity promotes the flow of wet granular materials. Mixtures of different percentage of silanized/unsilanized particles were prepared for tensile strength measurements. The tensile strength decreased as more silanized particles were added to the samples. The relationship between dimensionless tensile strength and void fraction followed the correlation found by Pierrat (1994). Contact angles were larger for the silanized particles, as compared with unsilanized ones.

  6. Underwater Flow Noise

    NASA Astrophysics Data System (ADS)

    Dowling, A. P.

    Lighthill's theory of aerodynamic sound provides an effective way of investigating underwater flow noise. When combined with a model of the coherent vortical structures in a turbulent boundary layer, it predicts the wave-number frequency pressure spectrum on a rigid surface and, in particular, highlights the rôle of surface viscous stresses as a source of low wave-number pressure fluctuations on a plane surface. The inclusion of surface curvature and flexibility enables the theory to be applied to acoustic streamers (sometimes known as towed arrays). The effect of the interior mechanical structure of the streamers on the flow noise is investigated. Simple algebraic forms are derived for the comparative performance of liquid and visco-elastic-filled streamers. The introduction of porous foam into a liquid streamer is found to be a particularly effective way of attenuating low wave-number disturbances, and theoretical predictions are compared with experiment.

  7. Osmotically driven pipe flows

    NASA Astrophysics Data System (ADS)

    Rio, Emmanuelle; Hansen, Rasmus; Jensen, Kaare; Bohr, Tomas; Clanet, Christophe

    2006-11-01

    The mechanism for the transport of sugar in plants is a key issue for the understanding of their growth. Since the 1930'ies the dominant model has been the so-called M"unch model (M"unch 1930) where the transport of sugar in the phloem of plants is viewed as a purely passive hydrodynamical process. According to M"unch, differences in osmotic pressure caused by differences in sugar concentration create a mean flow, transporting sugar from high concentration regions (e.g. leaves) to low concentration regions (e.g. new shoots or roots). We have performed experiments and numerical solutions for such flows under various conditions, to explore the nature of the ensuing rich fluid dynamics. Experiments are performed with solutions of dextran of various molecular weights and in channels of widths ranging from centimetric down to micrometric.

  8. Turbulent nonreacting swirling flows

    NASA Astrophysics Data System (ADS)

    Ramos, J. I.

    1984-06-01

    Numerical results for incompressible confined swirling flows in a model combustor were obtained using the k-epsilon and k-l models of turbulence developed by Ramos (1980, 1981). Calculations were performed for a model combustor consisting of a 3.43-cm diameter inner pipe and a 14.5-cm diameter outer pipe. The outside diameter of the inner pipe is 3.86 cm. It is shown that the k-epsilon model does predict a recirculation zone for both coswirl and counterswirl flow conditions if suitable inlet conditions are used. Both turbulence models predict a nonexistent recirculation zone under coswirl conditions. The calculated mean axial and tangential velocity profiles are compared with the experimental data of Vu and Gouldin (1980).

  9. Structural power flow measurement

    SciTech Connect

    Falter, K.J.; Keltie, R.F.

    1988-12-01

    Previous investigations of structural power flow through beam-like structures resulted in some unexplained anomalies in the calculated data. In order to develop structural power flow measurement as a viable technique for machine tool design, the causes of these anomalies needed to be found. Once found, techniques for eliminating the errors could be developed. Error sources were found in the experimental apparatus itself as well as in the instrumentation. Although flexural waves are the carriers of power in the experimental apparatus, at some frequencies longitudinal waves were excited which were picked up by the accelerometers and altered power measurements. Errors were found in the phase and gain response of the sensors and amplifiers used for measurement. A transfer function correction technique was employed to compensate for these instrumentation errors.

  10. Modelling pulmonary blood flow.

    PubMed

    Tawhai, Merryn H; Burrowes, Kelly S

    2008-11-30

    Computational model analysis has been used widely to understand and interpret complexity of interactions in the pulmonary system. Pulmonary blood transport is a multi-scale phenomenon that involves scale-dependent structure and function, therefore requiring different model assumptions for the microcirculation and the arterial or venous flows. The blood transport systems interact with the surrounding lung tissue, and are dependent on hydrostatic pressure gradients, control of vasoconstriction, and the topology and material composition of the vascular trees. This review focuses on computational models that have been developed to study the different mechanisms contributing to regional perfusion of the lung. Different models for the microcirculation and the pulmonary arteries are considered, including fractal approaches and anatomically-based methods. The studies that are reviewed illustrate the different complementary approaches that can be used to address the same physiological question of flow heterogeneity.

  11. The Flow of Energy

    NASA Astrophysics Data System (ADS)

    Znidarsic, F.; Robertson, G. A.

    In this paper, the flow of energy in materials is presented as mechanical waves with a distinct velocity or speed of transition. This speed of transition came about through the observations of cold fusion experiments, i.e., Low Energy Nuclear Reactions (LENR) and superconductor gravity experiments, both assumed speculative by mainstream science. In consideration of superconductor junctions, the LENR experiments have a similar speed of transition, which seems to imply that the reactions in the LENR experiment are discrete quantized reactions (energy - burst vs. continuous). Here an attempt is made to quantify this new condition as it applies to electrons; toward the progression of quantized energy flows (discrete energy burst) as a new source of clean energy and force mechanisms (i.e, propulsion).

  12. Hawaii Lava Flows

    NASA Image and Video Library

    2001-10-22

    This sequence of ASTER nighttime thermal images shows the Pu'u O'o lava flows entering the sea at Kamokuna on the southeast side of the Island of Hawaii. Each image covers an area of 9 x 12 km. The acquisition dates are April 4 2000, May 13 2000, May 22 2000 (upper row) and June 30 2000, August 1 2000 and January 1 2001 (lower row). Thermal band 14 has been color coded from black (coldest) through blue, red, yellow and white (hottest). The first 5 images show a time sequence of a single eruptive phase; the last image shows flows from a later eruptive phase. The images are located at 19.3 degrees north latitude, 155 degrees west longitude. http://photojournal.jpl.nasa.gov/catalog/PIA11093

  13. Nonlocal Curvature Flows

    NASA Astrophysics Data System (ADS)

    Chambolle, Antonin; Morini, Massimiliano; Ponsiglione, Marcello

    2015-12-01

    This paper aims at building a unified framework to deal with a wide class of local and nonlocal translation-invariant geometric flows. We introduce a class of nonlocal generalized mean curvatures and prove the existence and uniqueness for the level set formulation of the corresponding geometric flows. We then introduce a class of generalized perimeters, whose first variation is an admissible generalized curvature. Within this class, we implement a minimizing movements scheme and we prove that it approximates the viscosity solution of the corresponding level set PDE. We also describe several examples and applications. Besides recovering and presenting in a unified way existence, uniqueness, and approximation results for several geometric motions already studied and scattered in the literature, the theory developed in this paper also allows us to establish new results.

  14. Microfluidic flow spectrometer

    NASA Astrophysics Data System (ADS)

    Vázquez-Vergara, Pamela; Torres Rojas, Aimee M.; Guevara-Pantoja, Pablo E.; Corvera Poiré, Eugenia; Caballero-Robledo, Gabriel A.

    2017-07-01

    We present a microfluidic device which allows one to study the dynamics of oscillatory flows for a frequency range between 1 and 300 Hz. The fluid in the microdevice could be Newtonian, viscoelastic, or even a biofluid, since the device is made of PMMA, which makes it biocompatible and free of elastomeric elements. Coupling a piezoelectric to a micropiston allows one to impose periodic movement to the fluid, with zero mean flow and amplitudes of up to 20~μ m, within the microchannels in which the dynamics is studied. The use of a fast camera coupled to a microscope allows one to study the dynamics of 1~μ m tracer particles and interfaces at an image acquisition rate as fast as 5000 frames per second. The fabrication of the device is easy and cost-effective, since it is based on the use of a micromilling machine. The dynamics of a Newtonian fluid is studied as a proof of principle.

  15. Lateral flow assays

    PubMed Central

    Koczula, Katarzyna M.

    2016-01-01

    Lateral flow assays (LFAs) are the technology behind low-cost, simple, rapid and portable detection devices popular in biomedicine, agriculture, food and environmental sciences. This review presents an overview of the principle of the method and the critical components of the assay, focusing on lateral flow immunoassays. This type of assay has recently attracted considerable interest because of its potential to provide instantaneous diagnosis directly to patients. The range and interpretation of results and parameters used for evaluation of the assay will also be discussed. The main advantages and disadvantages of LFAs will be summarized and relevant future improvements to testing devices and strategies will be proposed. Finally, the major recent advances and future diagnostic applications in the LFA field will be explored. PMID:27365041

  16. KSC's work flow assistant

    NASA Technical Reports Server (NTRS)

    Wilkinson, John; Johnson, Earl

    1991-01-01

    The work flow assistant (WFA) is an advanced technology project under the shuttle processing data management system (SPDMS) at Kennedy Space Center (KSC). It will be utilized for short range scheduling, controlling work flow on the floor, and providing near real-time status for all major space transportation systems (STS) work centers at KSC. It will increase personnel and STS safety and improve productivity through deeper active scheduling that includes tracking and correlation of STS and ground support equipment (GSE) configuration and work. It will also provide greater accessibility to this data. WFA defines a standards concept for scheduling data which permits both commercial off-the-shelf (COTS) scheduling tools and WFA developed applications to be reused. WFA will utilize industry standard languages and workstations to achieve a scalable, adaptable, and portable architecture which may be used at other sites.

  17. Oahu Groundwater Flow Model

    DOE Data Explorer

    Nicole Lautze

    2015-01-01

    Groundwater flow model for the island of Oahu. Data is from the following sources: Rotzoll, K., A.I. El-Kadi. 2007. Numerical Ground-Water Flow Simulation for Red Hill Fuel Storage Facilities, NAVFAC Pacific, Oahu, Hawaii - Prepared TEC, Inc. Water Resources Research Center, University of Hawaii, Honolulu.; Whittier, R.B., K. Rotzoll, S. Dhal, A.I. El-Kadi, C. Ray, G. Chen, and D. Chang. 2004. Hawaii Source Water Assessment Program Report – Volume VII – Island of Oahu Source Water Assessment Program Report. Prepared for the Hawaii Department of Health, Safe Drinking Water Branch. University of Hawaii, Water Resources Research Center. Updated 2008.; and Whittier, R. and A.I. El-Kadi. 2009. Human and Environmental Risk Ranking of Onsite Sewage Disposal Systems – Final. Prepared by the University of Hawaii, Dept. of Geology and Geophysics for the State of Hawaii Dept. of Health, Safe Drinking Water Branch. December 2009.

  18. Vortex flow aerodynamics

    NASA Technical Reports Server (NTRS)

    Smith, J. H. B.; Campbell, J. F.; Young, A. D. (Editor)

    1992-01-01

    The principal emphasis of the meeting was to be on the understanding and prediction of separation-induced vortex flows and their effects on vehicle performance, stability, control, and structural design loads. This report shows that a substantial amount of the papers covering this area were received from a wide range of countries, together with an attendance that was even more diverse. In itself, this testifies to the current interest in the subject and to the appropriateness of the Panel's choice of topic and approach. An attempt is made to summarize each paper delivered, and to relate the contributions made in the papers and in the discussions to some of the important aspects of vortex flow aerodynamics. This reveals significant progress and important clarifications, but also brings out remaining weaknesses in predictive capability and gaps in understanding. Where possible, conclusions are drawn and areas of continuing concern are identified.

  19. Fluid Flow of Vitrectomy

    NASA Astrophysics Data System (ADS)

    Sharif-Kashani, Pooria; Juan, Tingting; Hubschman, Jean-Pierre; Eldredge, Jeff D.; Pirouz Kavehpour, H.

    2011-11-01

    Vitrectomy is a microsurgical technique to remove the vitreous gel from the vitreous cavity. Due to the viscoelastic nature of the vitreous gel, its complex fluidic behavior during vitrectomy affects the outcome of the procedure. Therefore, the knowledge of such behavior is essential for better designing the vitrectomy devices, such as vitreous cutters, and tuning the system settings such as port and shaft diameters, infusion, vacuum, and cutting rate. We studied the viscoelastic properties of porcine vitreous humor using a stressed-control shear rheometer and obtained its relaxation time, retardation time, and shear-zero viscosity. We performed a computational study of the flow in a vitreous cutter using the viscoelastic parameters obtained from the rheology experiments. We found significant differences between the modeled vitreous gel and a Newtonian surrogate fluid in the flow behavior and performance of the vitreous cutter. Our results will help in understanding of the vitreous behavior during vitrectomy and providing guidelines for new vitreous cutter design.

  20. Vortex flow aerodynamics

    NASA Technical Reports Server (NTRS)

    Smith, J. H. B.; Campbell, J. F.; Young, A. D. (Editor)

    1992-01-01

    The principal emphasis of the meeting was to be on the understanding and prediction of separation-induced vortex flows and their effects on vehicle performance, stability, control, and structural design loads. This report shows that a substantial amount of the papers covering this area were received from a wide range of countries, together with an attendance that was even more diverse. In itself, this testifies to the current interest in the subject and to the appropriateness of the Panel's choice of topic and approach. An attempt is made to summarize each paper delivered, and to relate the contributions made in the papers and in the discussions to some of the important aspects of vortex flow aerodynamics. This reveals significant progress and important clarifications, but also brings out remaining weaknesses in predictive capability and gaps in understanding. Where possible, conclusions are drawn and areas of continuing concern are identified.

  1. Capillary Flow Experiment

    NASA Image and Video Library

    2014-06-19

    ISS040-E-015545 (19 June 2014) --- European Space Agency astronaut Alexander Gerst, Expedition 40 flight engineer, conducts a session with the Capillary Flow Experiment (CFE-2) in the Harmony node of the International Space Station. CFE is a suite of fluid physics experiments that investigate how fluids behave in microgravity which could benefit water and fuel delivery systems on future spacecraft. Scientists designed the CFE-2 to study properties of fluids and bubbles inside containers with a specific 3-D geometry.

  2. Capillary Flow Experiment

    NASA Image and Video Library

    2014-06-19

    ISS040-E-015539 (19 June 2014) --- NASA astronaut Reid Wiseman, Expedition 40 flight engineer, conducts a session with the Capillary Flow Experiment (CFE-2) in the Harmony node of the International Space Station. CFE is a suite of fluid physics experiments that investigate how fluids behave in microgravity which could benefit water and fuel delivery systems on future spacecraft. Scientists designed the CFE-2 to study properties of fluids and bubbles inside containers with a specific 3-D geometry.

  3. On rotational conical flow

    NASA Technical Reports Server (NTRS)

    Ferrari, Carlo

    1952-01-01

    Some general properties of isoenergetic rotational conical fields are determined. For such fields, provided the physical parameters of the fluid flow are known on a conical reference surface, it being understood that they satisfy certain imposed conditions, it is shown how to construct the hodographs in the various meridional semiplanes, as the envelope of either the tangents to the hodographs or of the osculatory circles.

  4. Hypogenetic chaotic jerk flows

    NASA Astrophysics Data System (ADS)

    Li, Chunbiao; Sprott, Julien Clinton; Xing, Hongyan

    2016-03-01

    Removing the amplitude or polarity information in the feedback loop of a jerk structure shows that special nonlinearities with partial information in the variable can also lead to chaos. Some striking properties are found for this kind of hypogenetic chaotic jerk flow, including multistability of symmetric coexisting attractors from an asymmetric structure, hidden attractors with respect to equilibria but with global attraction, easy amplitude control, and phase reversal which is convenient for chaos applications.

  5. Projectile Base Flow Analysis

    DTIC Science & Technology

    2007-11-02

    S) AND ADDRESS(ES) DCW Industries, Inc. 5354 Palm Drive La Canada, CA 91011 8. PERFORMING ORGANIZATION...REPORT NUMBER DCW -38-R-05 9. SPONSORING / MONITORING AGENCY NAME(S) AND ADDRESS(ES) U. S. Army Research Office...Turbulence Modeling for CFD, Second Edition, DCW Industries, Inc., La Cañada, CA. Wilcox, D. C. (2001), “Projectile Base Flow Analysis,” DCW

  6. Chemically Reacting Turbulent Flow.

    DTIC Science & Technology

    1987-04-14

    the 1986 Spring Meeting of the Western States Section of the Combustion Institute, Banff , Canada (April 27-30,1986). 56. Wohl, K., Gazley, C., and Kapp...block number) FIELD GROUP SUB-GROUP concentration fluctuations; coacentration measurement ;densitv, effects;digitai line camera;flow visualization; hot ...Either of two techniques, hot -wire anemometry (HWA) or laser Doppler V velocimetry (LDV), are usually employed for real-time velocity measurement

  7. Determining Optical Flow.

    DTIC Science & Technology

    1980-04-01

    ioli of, conlvel gk:iicC OF C th0e 101 saitoil in th M Irii it icedcl diaei Alis. Illaiplc1) *rse id diffrent types of opticail flow pAtterns e rc...Properties of Binary Images in Two Dimensions ," IEEE’ Transactions on CoinputersC-20,5 (May 1971), pp. 551-561. Hladani, ., Ishai, G. & Gur, M. (1980

  8. Complex Flows by Nanohydrodynamics

    SciTech Connect

    Alley, E; Covello, P; Alder, B

    2004-03-01

    The study of complex flows by particle simulations is speeded up over molecular dynamics (MD) by more than two orders of magnitude by employing a stochastic collision dynamics method (DSMC) extended to high density (CBA). As a consequence, a picture generated on a single processor shows the typical features of the Rayleigh-Taylor instability and is in quantitative agreement with the experimentally found long time behavior.

  9. Flow Control Technology

    DTIC Science & Technology

    2010-07-01

    downstream of the propeller system. Figure 16 and Figure 17 show the ADV used by Huxley and Hartman [5] as well as a flow diagram for their...Max 17° Figure 23: Power Coefficient of Asymmetric Test Trials vs. Sinusoid pitch schedule. The aim of the work by Huxley and Hartman [5] was...Fagley, Ph.D. candidate, worked with Cadets Thiago Huxley and Christopher Hartman on a feedback controlled cycloidal wave energy converter in

  10. Ridges and Flows

    NASA Image and Video Library

    2015-11-16

    Located southwest of Olympus Mons, this image captured by NASA 2001 Mars Odyssey spacecraft shows part of a complex region that has undergone several geologic processes. The hills have been modified by wind, creating narrow ridges, and then the entire region has been covered with volcanic flows from Olympus Mons. Orbit Number: 60744 Latitude: 13.4267 Longitude: 220.554 Instrument: VIS Captured: 2015-08-24 10:00 http://photojournal.jpl.nasa.gov/catalog/PIA20093

  11. Heat flow in Oklahoma

    SciTech Connect

    Cranganu, C.; Deming, D.

    1996-12-31

    Oklahoma is one area in which terrestrial heat flow data are sparse. The thermal state of the southern mid-continent, however, is a key to understanding several important geologic problems. These include thermal anomalies associated with Paleozoic fluid migrations and the formation of Mississippi Valley-type lead-zinc deposits, the thermal evolution of the Arkoma and Anadarko sedimentary basins, and the history of hydrocarbon generation and overpressuring in the Anadarko Basin. In the late 1920s, the American Petroleum Institute made a set of equilibrium temperature logs in idle oil wells. These temperature data are generally regarded as being high quality, accurate estimates of rock temperature and they cover the entire central part of Oklahoma. Average thermal gradients in the API survey range from 14 to 43 {sup 0}C/km (average 31.2 {sup 0}C/km) over depth intervals that extend from the surface to a an average depth of 961 m. Geothermal gradients decrease from NNE to SSW. The observed change in thermal gradients could be due to a number of factors. The change in thermal gradients could simply reflect changes in lithology and thermal conductivity. Alternatively, the variation in thermal gradients could be indicative of a change in heat flow related perhaps to variations in the concentration of radioactive heat-producing elements in the crust or heat transport by one or more regional groundwater flow systems. We are proceeding to reduce ambiguity in interpretation by estimating heat flow from thermal conductivity measurements on drill cuttings and heat production from available gamma-ray logs which penetrate basement rocks.

  12. Heat flow in Oklahoma

    SciTech Connect

    Cranganu, C.; Deming, D. )

    1996-01-01

    Oklahoma is one area in which terrestrial heat flow data are sparse. The thermal state of the southern mid-continent, however, is a key to understanding several important geologic problems. These include thermal anomalies associated with Paleozoic fluid migrations and the formation of Mississippi Valley-type lead-zinc deposits, the thermal evolution of the Arkoma and Anadarko sedimentary basins, and the history of hydrocarbon generation and overpressuring in the Anadarko Basin. In the late 1920s, the American Petroleum Institute made a set of equilibrium temperature logs in idle oil wells. These temperature data are generally regarded as being high quality, accurate estimates of rock temperature and they cover the entire central part of Oklahoma. Average thermal gradients in the API survey range from 14 to 43 [sup 0]C/km (average 31.2 [sup 0]C/km) over depth intervals that extend from the surface to a an average depth of 961 m. Geothermal gradients decrease from NNE to SSW. The observed change in thermal gradients could be due to a number of factors. The change in thermal gradients could simply reflect changes in lithology and thermal conductivity. Alternatively, the variation in thermal gradients could be indicative of a change in heat flow related perhaps to variations in the concentration of radioactive heat-producing elements in the crust or heat transport by one or more regional groundwater flow systems. We are proceeding to reduce ambiguity in interpretation by estimating heat flow from thermal conductivity measurements on drill cuttings and heat production from available gamma-ray logs which penetrate basement rocks.

  13. Lava flows and domes

    SciTech Connect

    Fink, J. )

    1989-01-01

    This book discusses emplacement of silicic domes and mafic lava flows. The authors have utilized the combination of field, experimental and theoretical methods to constrain various characteristics of recently-emplaced lavas, including dimensions, growth rates, surface morphology, deformation styles, rheology, and volatile contents. Filed measurements from numerous volcanoes are presented. Focus is on data from Mount St. Helens. The value of such investigations is addressed.

  14. Capillary Flow Experiment

    NASA Image and Video Library

    2014-06-19

    ISS040-E-015523 (19 June 2014) --- European Space Agency astronaut Alexander Gerst, Expedition 40 flight engineer, conducts a session with the Capillary Flow Experiment (CFE-2) in the Harmony node of the International Space Station. CFE is a suite of fluid physics experiments that investigate how fluids behave in microgravity which could benefit water and fuel delivery systems on future spacecraft. Scientists designed the CFE-2 to study properties of fluids and bubbles inside containers with a specific 3-D geometry.

  15. Capillary Flow Experiment

    NASA Image and Video Library

    2014-06-19

    ISS040-E-015536 (19 June 2014) --- European Space Agency astronaut Alexander Gerst, Expedition 40 flight engineer, conducts a session with the Capillary Flow Experiment (CFE-2) in the Harmony node of the International Space Station. CFE is a suite of fluid physics experiments that investigate how fluids behave in microgravity which could benefit water and fuel delivery systems on future spacecraft. Scientists designed the CFE-2 to study properties of fluids and bubbles inside containers with a specific 3-D geometry.

  16. Capillary Flow Experiment

    NASA Image and Video Library

    2014-06-19

    ISS040-E-015532 (19 June 2014) --- European Space Agency astronaut Alexander Gerst, Expedition 40 flight engineer, conducts a session with the Capillary Flow Experiment (CFE-2) in the Harmony node of the International Space Station. CFE is a suite of fluid physics experiments that investigate how fluids behave in microgravity which could benefit water and fuel delivery systems on future spacecraft. Scientists designed the CFE-2 to study properties of fluids and bubbles inside containers with a specific 3-D geometry.

  17. Capillary Flow Experiment

    NASA Image and Video Library

    2014-06-19

    ISS040-E-015543 (19 June 2014) --- European Space Agency astronaut Alexander Gerst, Expedition 40 flight engineer, conducts a session with the Capillary Flow Experiment (CFE-2) in the Harmony node of the International Space Station. CFE is a suite of fluid physics experiments that investigate how fluids behave in microgravity which could benefit water and fuel delivery systems on future spacecraft. Scientists designed the CFE-2 to study properties of fluids and bubbles inside containers with a specific 3-D geometry.

  18. Unsteady Turbopump Flow Simulations

    NASA Technical Reports Server (NTRS)

    Centin, Kiris C.; Kwak, Dochan

    2001-01-01

    The objective of the current effort is two-fold: 1) to provide a computational framework for design and analysis of the entire fuel supply system of a liquid rocket engine; and 2) to provide high-fidelity unsteady turbopump flow analysis capability to support the design of pump sub-systems for advanced space transportation vehicle. Since the space launch systems in the near future are likely to involve liquid propulsion system, increasing the efficiency and reliability of the turbopump components is an important task. To date, computational tools for design/analysis of turbopump flow are based on relatively lower fidelity methods. Unsteady, three-dimensional viscous flow analysis tool involving stationary and rotational components for the entire turbopump assembly has not been available, at least, for real-world engineering applications. Present effort is an attempt to provide this capability so that developers of the vehicle will be able to extract such information as transient flow phenomena for start up, impact of non-uniform inflow, system vibration and impact on the structure. Those quantities are not readily available from simplified design tools. In this presentation, the progress being made toward complete turbo-pump simulation capability for a liquid rocket engine is reported. Space Shuttle Main Engine (SSME) turbo-pump is used as a test case for the performance evaluation of the hybrid MPI/Open-MP and MLP versions of the INS3D code. Relative motion of the grid system for rotor-stator interaction was obtained by employing overset grid techniques. Time-accuracy of the scheme has been evaluated by using simple test cases. Unsteady computations for SSME turbopump, which contains 106 zones with 34.5 Million grid points, are currently underway on Origin 2000 systems at NASA Ames Research Center. Results from these time-accurate simulations with moving boundary capability and the performance of the parallel versions of the code will be presented.

  19. Transonic swirling nozzle flow

    NASA Astrophysics Data System (ADS)

    Keith, Theo G., Jr.; Pawlas, Gary E.

    1991-06-01

    A numerical model of viscous transonic swirling flow in axisymmetric nozzles is developed. MacCormack's implicit Gauss-Seidel method is applied to the thin-layer Navier-Stokes equations in transformed coordinates. Numerical results are compared with experimental data to validate the method. The effect of swirl and viscosity on nozzle performance are demonstrated by examining wall pressures, Mach contours, and integral parameters.

  20. Nighttime Lava Flows

    NASA Technical Reports Server (NTRS)

    2004-01-01

    [figure removed for brevity, see original site]

    This nighttime IR image is of lava flows from Arsia Mons, the southernmost of the three Tharsis Montes. Lava flow surfaces are generally rough, and trap sand and dust with time. The addition of sand/dust will affect the nighttime IR appearance of the surface [dust cools quickly and is darker than slow cooling rocks in the nighttime IR]. The rough, rockier surface of young flows are brighter than the older dust covered flows.

    Image information: IR instrument. Latitude -14, Longitude 247.4 East (112.6 West). 100 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  1. TEP process flow diagram

    SciTech Connect

    Wilms, R Scott; Carlson, Bryan; Coons, James; Kubic, William

    2008-01-01

    This presentation describes the development of the proposed Process Flow Diagram (PFD) for the Tokamak Exhaust Processing System (TEP) of ITER. A brief review of design efforts leading up to the PFD is followed by a description of the hydrogen-like, air-like, and waterlike processes. Two new design values are described; the mostcommon and most-demanding design values. The proposed PFD is shown to meet specifications under the most-common and mostdemanding design values.

  2. Flow-batch miniaturization.

    PubMed

    Monte-Filho, Severino S; Lima, Marcelo B; Andrade, Stéfani I E; Harding, David P; Fagundes, Yebá N M; Santos, Sergio R B; Lemos, Sherlan G; Araújo, Mario C U

    2011-10-30

    This study introduces the first micro-flow-batch analyzer (μFBA). A simple, low-cost, deep urethane-acrylate photo-resist ultraviolet-lithographic technique was used in its development. Details of the microfabrication process are presented including; the use of two superimposed photo-masks to improve the micro-channel and stop chamber border definition, as well as integration of an LED/phototransistor photometric pair, while using an open nylon-thread (fishing line) micro-mixing system for solutions homogenization. The system was used for photometric determination of Fe(II) in oral solution iron supplements employing the well-known 1,10-phenanthroline method, with instantaneously prepared micro-chamber calibration solutions. All analytical processes were accomplished by simply changing the timing parameters in the control software. It must be emphasized here that there was no outside preparation of the standard calibration solutions; the mixing was all done in-chamber/in-line, with all solutions maintained flowing while being proportioned for the measurement processes. The μFBA results were acceptable when compared to the reference method, and comparable to normal flow-batch systems. It was possible both to project and build a low-cost probe with high sample throughput (about 120 h(-1)), low relative standard deviations (about 1.1%), and reduced reagent consumption (30 times less than the reference method). The μFBA system based on urethane-acrylate presented satisfactory physical and chemical properties while keeping the flexibility, versatility, robustness, and multi-task characteristics of normal flow-batch analyzers. The μFBA system contributes to the advance of micro-analytical instrumentation, while realizing the basic principles of "Green Chemistry".

  3. FLOW SYSTEM FOR REACTOR

    DOEpatents

    Zinn, W.H.

    1963-06-11

    A reactor is designed with means for terminating the reaction when returning coolant is below a predetermined temperature. Coolant flowing from the reactor passes through a heat exchanger to a lower reservoir, and then circulates between the lower reservoir and an upper reservoir before being returned to the reactor. Means responsive to the temperature of the coolant in the return conduit terminate the chain reaction when the temperature reaches a predetermined minimum value. (AEC)

  4. Olympus Mons Flows

    NASA Technical Reports Server (NTRS)

    2002-01-01

    [figure removed for brevity, see original site]

    Like drippings from a candle, these lava flows on the flank of Olympus Mons volcano demonstrate how it became the largest volcano in the solar system. Multiple flows from an unknowable number of eruptions have piled one on top of another until the mountain of lava reached a height of 27 km above the average Martian elevation. The change in texture seen in the bottom 1/3 of the image marks a break in slope from the flank of the volcano to the north (top) and the flat plain surrounding it. The direction of flows changes from roughly N-S to E-W, suggesting another source for the flows on the plain.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  5. Transition Region Flows

    NASA Astrophysics Data System (ADS)

    Brekke, P.; Murdin, P.

    2000-11-01

    Ultraviolet emission lines emitted from the SOLAR TRANSITION REGION are often shifted from their expected rest wavelengths. Shifts of spectral lines are due to the so-called DOPPLER EFFECT, where the source of emission is moving either away from or towards the observer, causing a change in the apparent wavelength. The shifted emission lines are most often interpreted as a flow of plasma along ...

  6. Photoacoustic flow cytometry

    PubMed Central

    Galanzha, Ekaterina I.; Zharov, Vladimir P.

    2016-01-01

    Conventional flow cytometry using scattering and fluorescent detection methods has been a fundamental tool of biological discoveries for many years. Invasive extraction of cells from a living organism, however, may lead to changes in cell properties and prevents the long-term study of cells in their native environment. Here, we summarize recent advances of new generation flow cytometry for in vivo noninvasive label-free or targeted detection of cells in blood, lymph, bone, cerebral and plant vasculatures using photoacoustic (PA) detection techniques, multispectral high-pulse-repetition-rate lasers, tunable ultrasharp (up to 0.8 nm) rainbow plasmonic nanoprobes, positive and negative PA contrasts, in vivo magnetic enrichment, time-of-flight cell velocity measurement, PA spectral analysis, and integration of PA, photothermal (PT), fluorescent, and Raman methods. Unique applications of this tool are reviewed with a focus on ultrasensitive detection of normal blood cells at different functional states (e.g., apoptotic and necrotic) and rare abnormal cells including circulating tumor cells (CTCs), cancer stem cells, pathogens, clots, sickle cells as well as pharmokinetics of nanoparticles, dyes, microbubbles and drug nanocarriers. Using this tool we discovered that palpation, biopsy, or surgery can enhance CTC release from primary tumors, increasing the risk of metastasis. The novel fluctuation flow cytometry provided the opportunity for the dynamic study of blood rheology including red blood cell aggregation and clot formation in different medical conditions (e.g., blood disorders, cancer, or surgery). Theranostics, as a combination of PA diagnosis and PT nanobubble-amplified multiplex therapy, was used for eradication of CTCs, purging of infected blood, and thrombolysis of clots using PA guidance to control therapy efficiency. In vivo flow cytometry using a portable fiber-based devices can provide a breakthrough platform for early diagnosis of cancer, infection and

  7. Vortex shedding flow meter performance at high flow velocities

    NASA Technical Reports Server (NTRS)

    Siegwarth, J. D.

    1986-01-01

    In some of the ducts of the Space Shuttle Main Engine (SSME), the maximum liquid oxygen flow velocities approach 10 times those at which liquid flow measurements are normally made. The hydrogen gas flow velocities in other ducts exceed the maximum for gas flow measurement by more than a factor of 3. The results presented here show from water flow tests that vortex shedding flow meters of the appropriate design can measure water flow to velocities in excess of 55 m/s, which is a Reynolds number of about 2 million. Air flow tests have shown that the same meter can measure flow to a Reynolds number of at least 22 million. Vortex shedding meters were installed in two of the SSME ducts and tested with water flow. Narrow spectrum lines were obtained and the meter output frequencies were proportional to flow to + or - 0.5% or better over the test range with no flow conditioning, even though the ducts had multiple bends preceeding the meter location. Meters with the shedding elements only partially spanning the pipe and some meters with ring shaped shedding elements were also tested.

  8. Conversational flow promotes solidarity.

    PubMed

    Koudenburg, Namkje; Postmes, Tom; Gordijn, Ernestine H

    2013-01-01

    Social interaction is fundamental to the development of various aspects of "we-ness". Previous research has focused on the role the content of interaction plays in establishing feelings of unity, belongingness and shared reality (a cluster of variables referred to as solidarity here). The present paper is less concerned with content, but focuses on the form of social interaction. We propose that the degree to which conversations flow smoothly or not is, of itself, a cue to solidarity. We test this hypothesis in samples of unacquainted and acquainted dyads who communicate via headsets. Conversational flow is disrupted by introducing a delay in the auditory feedback (vs. no delay). Results of three studies show that smoothly coordinated conversations (compared with disrupted conversations and a control condition) increase feelings of belonging and perceptions of group entitativity, independently of conversation content. These effects are driven by the subjective experience of conversational flow. Our data suggest that this process occurs largely beyond individuals' control. We conclude that the form of social interaction is a powerful cue for inferring group solidarity. Implications for the impact of modern communication technology on developing a shared social identity are discussed.

  9. Convective heat flow probe

    DOEpatents

    Dunn, James C.; Hardee, Harry C.; Striker, Richard P.

    1985-01-01

    A convective heat flow probe device is provided which measures heat flow and fluid flow magnitude in the formation surrounding a borehole. The probe comprises an elongate housing adapted to be lowered down into the borehole; a plurality of heaters extending along the probe for heating the formation surrounding the borehole; a plurality of temperature sensors arranged around the periphery of the probe for measuring the temperature of the surrounding formation after heating thereof by the heater elements. The temperature sensors and heater elements are mounted in a plurality of separate heater pads which are supported by the housing and which are adapted to be radially expanded into firm engagement with the walls of the borehole. The heat supplied by the heater elements and the temperatures measured by the temperature sensors are monitored and used in providing the desired measurements. The outer peripheral surfaces of the heater pads are configured as segments of a cylinder and form a full cylinder when taken together. A plurality of temperature sensors are located on each pad so as to extend along the length and across the width thereof, with a heating element being located in each pad beneath the temperature sensors. An expansion mechanism driven by a clamping motor provides expansion and retraction of the heater pads and expandable packer-type seals are provided along the probe above and below the heater pads.

  10. Convective heat flow probe

    DOEpatents

    Dunn, J.C.; Hardee, H.C.; Striker, R.P.

    1984-01-09

    A convective heat flow probe device is provided which measures heat flow and fluid flow magnitude in the formation surrounding a borehole. The probe comprises an elongate housing adapted to be lowered down into the borehole; a plurality of heaters extending along the probe for heating the formation surrounding the borehole; a plurality of temperature sensors arranged around the periphery of the probe for measuring the temperature of the surrounding formation after heating thereof by the heater elements. The temperature sensors and heater elements are mounted in a plurality of separate heater pads which are supported by the housing and which are adapted to be radially expanded into firm engagement with the walls of the borehole. The heat supplied by the heater elements and the temperatures measured by the temperature sensors are monitored and used in providing the desired measurements. The outer peripheral surfaces of the heater pads are configured as segments of a cylinder and form a full cylinder when taken together. A plurality of temperature sensors are located on each pad so as to extend along the length and across the width thereof, with a heating element being located in each pad beneath the temperature sensors. An expansion mechanism driven by a clamping motor provides expansion and retraction of the heater pads and expandable packet-type seals are provided along the probe above and below the heater pads.

  11. Seasonal Flows in Palikir Crater

    NASA Image and Video Library

    2013-05-15

    Seasonal flows on warm Martian slopes may be caused by the flow of salty water on Mars, active today when the surface is warm above the freezing point of the solution. This observation is from NASA Mars Reconnaissance Orbiter.

  12. Flow Boiling and Condensation Experiment

    NASA Image and Video Library

    The Flow Boiling and Condensation Experiment is another investigation that examines the flow of a mixture of liquids and the vapors they produce when in contact with hot space system equipment. Coo...

  13. Vortex generator for flow control

    NASA Technical Reports Server (NTRS)

    Collins, Jr., Earl R. (Inventor); Marner, Wilbur J. (Inventor); Rohatgi, Naresh K. (Inventor)

    1989-01-01

    Fluidics flow control of a multiphase supply using a cylindrical chamber is achieved by introducing the supply flow radially into the chamber. The supply flow exits through a port in the center at the chamber. A control fluid is then introduced tangentially about 90.degree. upstream from the supply port. A second control fluid port may be added about 90.degree. upstream from the first control fluid port, but preferably two sets of supply and control ports are added with like ports diametrically opposite each other. The control fluid flows against the circular wall of the control chamber, which introduces a vortex in the flow of the supply flow that decays into a spiral path to the exit port in the center of the chamber. The control flow rate may thus be used to control the spiral path, and therefore the supply flow rate through the exit port.

  14. Radial flow pulse jet mixer

    DOEpatents

    VanOsdol, John G.

    2013-06-25

    The disclosure provides a pulse jet mixing vessel for mixing a plurality of solid particles. The pulse jet mixing vessel is comprised of a sludge basin, a flow surface surrounding the sludge basin, and a downcoming flow annulus between the flow surface and an inner shroud. The pulse jet mixing vessel is additionally comprised of an upper vessel pressurization volume in fluid communication with the downcoming flow annulus, and an inner shroud surge volume separated from the downcoming flow annulus by the inner shroud. When the solid particles are resting on the sludge basin and a fluid such as water is atop the particles and extending into the downcoming flow annulus and the inner shroud surge volume, mixing occurs by pressurization of the upper vessel pressurization volume, generating an inward radial flow over the flow surface and an upwash jet at the center of the sludge basin.

  15. FAITH Water Channel Flow Visualization

    NASA Image and Video Library

    Water channel flow visualization experiments are performed on a three dimensional model of a small hill. This experiment was part of a series of measurements of the complex fluid flow around the hi...

  16. Numerical study of juncture flows

    NASA Technical Reports Server (NTRS)

    Chen, Chung-Lung; Hung, Ching-Mao

    1991-01-01

    The present paper describes a computational study of laminar/turbulent and subsonic/supersonic horseshoe vortex systems generated by a cylindrical protuberance mounted on a flat plate. Various vortex structures are predicted and discussed. Low-speed laminar juncture flows are computed to determine the Reynolds number effect with the same incoming boundary-layer thickness. For a low subsonic laminar flow, the number of vortex arrays increases with the Reynolds number, in agreement with both experimental and numerical observations. Qualitative comparisons are made along with the computations, experimental observations, and analytical work. For incompressible flow, the relationships among pressure extrema, vorticity, and singular points in flow structure are discussed. A parametric study of the effect of the free-stream Mach number on the flow structure for laminar flow is conducted. The juncture flow when the incoming flow is turbulent and supersonic is computed.

  17. Lava Flows of Daedalia Planum

    NASA Image and Video Library

    2002-12-19

    This NASA Mars Odyssey image captures a portion of several lava flows in Daedalia Planum southwest of the Arsia Mons shield volcano. Textures characteristic of the variable surface roughness associated with different lava flows in this region are easily s

  18. Lava Flows around Olympus Mons

    NASA Image and Video Library

    2002-12-16

    This image from NASA Mars Odyssey of lava flows around the large scarp of Olympus Mons reveals textures characteristic of the variable surface roughness associated with different lava flows in this region.

  19. Asymmetric reactions in continuous flow

    PubMed Central

    Mak, Xiao Yin; Laurino, Paola

    2009-01-01

    Summary An overview of asymmetric synthesis in continuous flow and microreactors is presented in this review. Applications of homogeneous and heterogeneous asymmetric catalysis as well as biocatalysis in flow are discussed. PMID:19478913

  20. Virtual Flow Simulator

    SciTech Connect

    Calderer, Antoni; Yang, Xiaolei; Angelidis, Dionysios; Khosronejad, Ali; Le, Trung; Kang, Seokkoo; Gilmanov, Anvar; Ge, Liang; Borazjani, Iman

    2015-10-05

    Virtual Flow Simulator (VFS) is a state-of-the-art computational fluid mechanics (CFD) package that is capable of simulating multi-physics/multi-phase flows with the most advanced turbulence models (RANS, LES) over complex terrains. The flow solver is based on the Curvilinear Immersed Boundary (CURVIB) method to handle geometrically complex and moving domains. Different modules of the VFS package can provide different simulation capabilities for specific applications ranging from the fluid-structure interaction (FSI) of solid and deformable bodies, the two-phase free surface flow solver based on the level set method for ocean waves, sediment transport models in rivers and the large-scale models of wind farms based on actuator lines and surfaces. All numerical features of VFS package have been validated with known analytical and experimental data as reported in the related journal articles. VFS package is suitable for a broad range of engineering applications within different industries. VFS has been used in different projects with applications in wind and hydrokinetic energy, offshore and near-shore ocean studies, cardiovascular and biological flows, and natural streams and river morphodynamics. Over the last decade, the development of VFS has been supported and assisted with the help of various United States companies and federal agencies that are listed in the sponsor lists. In this version, VFS-Wind contains all the necessary modeling tools for wind energy applications, including land-based and offshore wind farms. VFS is highly scalable to run on either desktop computers or high performance clusters (up to 16,000 CPUs). This released version comes with a detailed user’s manual and a set of case studies designed to facilitate the learning of the various aspects of the code in a comprehensive manner. The included documentation and support material has been elaborated in a collaboration effort with Sandia National Labs under the contract DE-EE0005482. The VFS

  1. Stochastically forced zonal flows

    NASA Astrophysics Data System (ADS)

    Srinivasan, Kaushik

    This thesis investigates the dynamics of multiple zonal jets, that spontaneously emerge on the barotropic beta-plane, driven by a homogenous and rapidly decorrelating forcing and damped by bottom drag. Decomposing the barotropic vorticity equation into the zonal-mean and eddy equations, and neglecting the eddy-eddy interactions, defines the quasi-linear (QL) system. Numerical solution of the QL system shows zonal jets with length scales comparable to jets obtained by solving the nonlinear (NL) system. Starting with the QL system, one can construct a deterministic equation for the evolution of the two-point single-time correlation function of the vorticity, from which one can obtain the Reynolds stress that drives the zonal mean flow. This deterministic system has an exact nonlinear solution, which is a homogenous eddy field with no jets. When the forcing is also isotropic in space, we characterize the linear stability of this jetless solution by calculating the critical stability curve in the parameter space and successfully comparing this analytic result with numerical solutions of the QL system. But the critical drag required for the onset of NL zonostrophic instability is up to a factor of six smaller than that for QL zonostrophic instability. The constraint of isotropic forcing is then relaxed and spatially anisotropic forcing is used to drive the jets. Meridionally drifting jets are observed whenever the forcing breaks an additional symmetry that we refer to as mirror, or reflexional symmetry. The magnitude of drift speed in our results shows a strong variation with both mu and beta: while the drift speed decreases almost linearly with decreasing mu, it actually increases as beta decreases. Similar drifting jets are also observed in QL, with the same direction (i.e. northward or southward) and similar magnitude as NL jet-drift. Starting from the laminar solution, and assuming a mean-flow that varies slowly with reference to the scale of the eddies, we obtain

  2. Basics of flow cytometry.

    PubMed

    Radcliff, G; Jaroszeski, M J

    1998-01-01

    In summary, a beginner requires fundamental knowledge about flow cytometric instrumentation in order to effectively use this technology. It is important to remember that flow cytometers are very complex instruments that are composed of four closely related systems. The fluidic system transports particles from a suspension through the cytometer for interrogation by an illumination system. The resulting light scattering and fluorescence is collected, filtered, and converted into electrical signals by the optical and electronics system. The data storage and computer control system saves acquired data and is also the user interface for controlling most instrument functions. These four systems provide a very unique and powerful analytical tool for researchers and clinicians. This is because they analyze the properties of individual particles, and thousands of particles can be analyzed in a matter of seconds. Thus, data for a flow cytometric sample are a collection of many measurements instead of a single bulk measurement. Basic knowledge of instrumentation is a tremendous aid to designing experiments that can be successfully analyzed using flow cytometry. For example, it is important to know the emission wavelength of the laser in the instrument that will be used for analysis. This wavelength is critical knowledge for selecting probes. It is also important to understand that a different range of wavelengths is detected for each fluorescent channel. This will aid selection of probes that are compatible with the flow cytometer. Understanding the complication that emission spectra overlap contributes to detection can be used to guide fluorochrome selections for multicolor analysis. All of these experiment design considerations that rely on knowledge of how flow cytometers work are a very practical and effective means of avoiding wasted time, energy, and costly reagents. Data analysis is a paramount issue in flow cytometry. Analysis includes interpreting as well as

  3. Analysis of axial flow turbines

    NASA Astrophysics Data System (ADS)

    Garg, V. K.

    A variety of steady and time-dependent, two and three dimensional numerical techniques for axial-flow turbulent design and analysis is reviewed. Meridional flow solutions are discussed, including the streamline curvature method, the matrix method, and finite element methods. Blade-to-blade flow solutions are considered, including singularity methods, field methods, and transonic blade-to-blade calculations. Three-dimensional flow solutions are briefly examined.

  4. Unsteady flow phenomena in turbomachines

    NASA Astrophysics Data System (ADS)

    Greitzer, Edward M.; Epstein, Alan H.; Giles, Michael B.; McCune, James E.; Tan, Choon S.

    1990-01-01

    Work carried out at the Gas Turbine Laboratory at M.I.T. as part of the multi-investigator effort on basic unsteady flow phenomena is described. Within the overall project, four separate tasks are specified. These are, in brief: unsteady flow in compressors; computational techniques for unsteady flows; unsteady phenomena, inlet distortion, and flow instabilities in multistage compressors; and unsteady vortical wakes behind blade rows - prediction of relationships with blade properties.

  5. Interference between boundary layer flow and wake flow

    NASA Astrophysics Data System (ADS)

    Kanemoto, T.; Toyokura, T.; Kurokawa, J.

    1981-03-01

    The characteristics of a flow in which the laminar boundary layer along a flat plate at zero incidence interferes with the turbulent wake behind a circular cylinder are examined for several relative positions of the cylinder and the plate. It is shown that turbulent velocity fluctuation of the wake flow results in the boundary layer flow transition from the laminar to the turbulent region. It is also shown that the velocity profile in the boundary layer region, when the flows interfere, can be well approximated by subtracting the velocity defect of the boundary layer unaffected by the wake from the velocity distribution of the wake flow unaffected by the wall.

  6. Stokes flow inside a sphere in an inviscid extensional flow

    NASA Astrophysics Data System (ADS)

    Krehbiel, Joel D.; Freund, Jonathan B.

    2017-08-01

    We derive the streamfunction solution for flow in and around a viscous sphere suspended in an inviscid extensional flow with matched stress boundary conditions, which is a model for estimating the stresses on a tiny suspended organism by a nearby expanding and collapsing bubble. The boundary conditions are enforced in an easily resolvable form by expressing the surface stresses as sums of Legendre and Gegenbauer functions. The flow inside the sphere reflects a balance of exterior inertia with internal viscous forces, which together are shown to constitute the relevant flow Reynolds number. The solution is evaluated to examine the flow field inside this sphere as a potential source of damage to the organism.

  7. Peak flow meter use - slideshow

    MedlinePlus

    ... medlineplus.gov/ency/presentations/100202.htm Peak flow meter use - Series—Peak flow meter use - part one To use the sharing features ... 7 out of 7 Overview A peak flow meter helps you check how well your asthma is ...

  8. Distorted turbulence in axisymmetric flow

    NASA Technical Reports Server (NTRS)

    Durbin, P. A.

    1981-01-01

    A solution to the rapid-distortion theory for small-scale turbulence in flow round an axisymmetric obstacle is derived. General formulae for velocity covariances and Eulerian time scales are obtained and are evaluated for the particular case of flow round a sphere. The large-scale limit for this flow is also discussed.

  9. COMPRESSIBLE FLOW, ENTRAINMENT, AND MEGAPLUME

    EPA Science Inventory

    It is generally believed that low Mach number, i.e., low-velocity, flow may be assumed to be incompressible flow. Under steady-state conditions, an exact equation of continuity may then be used to show that such flow is non-divergent. However, a rigorous, compressible fluid-dynam...

  10. Liquid/Gas Flow Mixers

    NASA Technical Reports Server (NTRS)

    Fabris, Gracio

    1994-01-01

    Improved devices mix gases and liquids into bubbly or foamy flows. Generates flowing, homogeneous foams or homogeneous dispersions of small, noncoalescing bubbles entrained in flowing liquids. Mixers useful in liquid-metal magnetohydrodynamic electric-power generator, froth flotation in mining industry, wastewater treatment, aerobic digestion, and stripping hydrocarbon contaminants from ground water.

  11. COMPRESSIBLE FLOW, ENTRAINMENT, AND MEGAPLUME

    EPA Science Inventory

    It is generally believed that low Mach number, i.e., low-velocity, flow may be assumed to be incompressible flow. Under steady-state conditions, an exact equation of continuity may then be used to show that such flow is non-divergent. However, a rigorous, compressible fluid-dynam...

  12. Flow of Talent at Zhongguancun

    ERIC Educational Resources Information Center

    Hansheng, Li; Ruixin, Kang

    2004-01-01

    This article reports the flow of talent at Zhongguancun. Zhongguancun, with its many enterprise opportunities, high returns, and concentration of large corporations, is an ideal place for talent to seek employment, and the flow of talent here is more lively than in other regions. The talent flow rate in Zhongguancun is 20 percent, but the flow…

  13. Bellows flow-induced vibrations

    NASA Technical Reports Server (NTRS)

    Tygielski, P. J.; Smyly, H. M.; Gerlach, C. R.

    1983-01-01

    The bellows flow excitation mechanism and results of comprehensive test program are summarized. The analytical model for predicting bellows flow induced stress is refined. The model includes the effects of an upstream elbow, arbitrary geometry, and multiple piles. A refined computer code for predicting flow induced stress is described which allows life prediction if a material S-N diagram is available.

  14. Flow shapes and higher harmonics in anisotropic transverse collective flow

    NASA Astrophysics Data System (ADS)

    Argintaru, Danut; Besliu, Calin; Jipa, Alexandru; Esanu, Tiberiu; Baban, Valerica; Cherciu, Madalin; Grossu, Valeriu

    2017-01-01

    In this paper we show that by using a jet-finder algorithm (the Anti- kT one) on UrQMD/C simulated (Au+Au at 4, 10 and 15A GeV) collisions, we can identify different flow shape structures (single flow stream events, two flow streams events, three flow streams events, etc.) and order the bulk of events in equivalence flow shape classes. Considering these flow streams as the main directions of anisotropic transverse flow, we show that the Fourier coefficients vn of anisotropic flow are better emphasized when we analyze the different event flow shape classes than when the events are mixed. Also, if we do not know the real orientation of the reaction plane, we can use as reference the Flow stream 1 -the main particle flow stream -orientation (Ψ_{Flowstream 1}) to highlight the initial shape of the participant nuclear matter in a central to peripheral collision, and the orientation of the participant plane of order n.

  15. Modeling shrouded stator cavity flows in axial-flow compressors

    SciTech Connect

    Wellborn, S.R.; Tolchinsky, I.; Okiishi, T.H.

    2000-01-01

    Experiments and computational analyses were completed to understand the nature of shrouded stator cavity flows. From this understanding, a one-dimensional model of the flow through shrouded stator cavities was developed. This model estimates the leakage mass flow, temperature rise, and angular momentum increase through the cavity, given geometry parameters and the flow conditions at the interface between the cavity and primary flow path. This cavity model consists of two components, one that estimates the flow characteristics through the labyrinth seals and the other that predicts the transfer of momentum due to windage. A description of the one-dimensional model is given. The incorporation and use of the one-dimensional model in a multistage compressor primary flow analysis tool is described. The combination of this model and the primary flow solver was used to reliably simulate the significant impact on performance of the increase of hub seal leakage in a twelve-stage axial-flow compressor. Observed higher temperatures of the hub region fluid, different stage matching, and lower overall efficiencies and core flow than expected could be correctly linked to increased hub seal clearance with this new technique. The importance of including these leakage flows in compressor simulations is shown.

  16. Influence of flow velocity on flow field's optical tomography diagnosis

    NASA Astrophysics Data System (ADS)

    Chen, Yun-yun; Yu, Yang; Zhong, Xia; Zhang, Ying-ying

    2017-01-01

    The effect of flow velocity is usually neglected when optical computerized tomography (OCT) methods are chosen to measure the temperature distribution of the flow fields up to now. In this paper, two sets of experiment are supplied to verify the effect of flow velocity on flow field's moiré tomography. Specifically speaking, the temperature results with the assumption that it is an isobaric process (omit the effect of flow velocity) in the measured flame flow fields, manifest that the isobaric supposition is not suitable for all the flames. And then, a condition, which can be adopted to judge that when the effect of flow velocity on its temperature reconstruction can not be neglected any more, is proposed. This study would provide some reference to the temperature diagnosis by the optical methods which are based on the measurement of the refractive index.

  17. Gas flow meter and method for measuring gas flow rate

    DOEpatents

    Robertson, Eric P.

    2006-08-01

    A gas flow rate meter includes an upstream line and two chambers having substantially equal, fixed volumes. An adjustable valve may direct the gas flow through the upstream line to either of the two chambers. A pressure monitoring device may be configured to prompt valve adjustments, directing the gas flow to an alternate chamber each time a pre-set pressure in the upstream line is reached. A method of measuring the gas flow rate measures the time required for the pressure in the upstream line to reach the pre-set pressure. The volume of the chamber and upstream line are known and fixed, thus the time required for the increase in pressure may be used to determine the flow rate of the gas. Another method of measuring the gas flow rate uses two pressure measurements of a fixed volume, taken at different times, to determine the flow rate of the gas.

  18. Flow between rotating disks. Part 1: Basic flow

    NASA Astrophysics Data System (ADS)

    Schneider, S. J.; Labbe, F.; Kaufman, H. N.; Szeri, A. Z.

    Multiplicity of basic flows, when the fluid is bounded by two infinite disks, reported by several investigators is examined with emphasis on whether, and under what conditions infinite disk flows approximate to laboratory flows between two finite disks. Laser Doppler velocity measurements were obtained in water between finite rotating disks, with and without through flow. Angular velocity ratios were studied for: (1) one disk rotating and the other stationary; (2) co-rotating disks of equal angular velocity; and (3) counter rotating disks of equal but opposite angular velocity. It is concluded that limiting flows are unique and are independent of flow history. With one disk rotating and the other stationary, the mid-radius limiting flow is recognized as the Batchelor profile of infinite disk theory. Other profiles, predicted by this theory to coexist with the Batchelor profile were neither observed experimentally nor were they calculated numerically by the finite disk solution obtained with a Galerkin, b-spline formulation.

  19. Rotating cooloing flows

    NASA Technical Reports Server (NTRS)

    Kley, Wilhelm; Mathews, William G.

    1995-01-01

    We describe the evolution of the hot interstellar medium in a large, slowly rotating elliptical galaxy. Although the rotation assumed is a small fraction of the circular velocity, in accordance with recent observations, it is sufficient to have a profound influence on the X-ray emission and cooling geometry of the interstellar gas. The hot gas cools into a disk that extends out to approximately 10 kpc. The cool, dusty disks observed in the majority of elliptical galaxies may arise naturally from internal cooling rather than from mergers with gas-rich companions. As a result of angular momentum conservation in the cooling flow, the soft X-ray isophotes are quite noticeably flatter than those of the stellar image. The gas temperature is higer along the rotation axis. The rotational velocity of the gas several kiloparcsecs above the central disk far exceeds the local stellar rotation and approaches the local circular velocity as it flows toward the galactic core. The detailed appearance of the X-ray image and velocity field of the X-ray gas provide information about the global rotational properties of giant ellipticals at radii too distant for optical observations. The overall pattern of rotation in these galaxies retains information about the origin of ellipticals, particularly of their merging history. In ellipticals having radio jets, if the jets are aligned with the rotation axis of the inner cooling flow, rotation within the jet could be sustained by the rotating environment. Since most large ellipticals have modest rotation, the X-ray observations at low spatial resolution, when interpreted with spherical theoretical models, give the impression that hot gas undergoes localized cooling to very low temperatures many kiloparcsecs from the galactic core. We suggest that such apparent cooling can result in a natural way as gas cools onto a rotating disk.

  20. Flow Along Valley Floors

    NASA Technical Reports Server (NTRS)

    2003-01-01

    [figure removed for brevity, see original site]

    Released 9 May 2003

    Lines indicative of flow in a valley floor (east to west) cut across similar lines in a slightly smaller valley (southeast to northwest), indicating both that material flowed along the valley floor (as opposed to across it) and that relative flow ages may be determined from crosscutting relationships.

    Image information: VIS instrument. Latitude 39.6, Longitude 31.1East (328.9). 19 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  1. Secondary Flow in Cascades.

    DTIC Science & Technology

    1984-06-01

    formulation on the other hand is more complex since it models the elliptic influence of the three dimensional pressure field. Computer time savings...thateur on-*,,. ,mim - -h arid ly h h nwsotie tc be conpared with the present anlyi ca rdc-h of angus ; eflec ofithe9 ue trto d10 ivsi secondary flow...fields," th arbesle Nuim-Sto weuotindfo but have been demonstrated to predict -2ea ueesn h it irt iv solu- complex three dimensional phenomena such ties

  2. Bondi flow revisited

    NASA Astrophysics Data System (ADS)

    Datta, Satadal

    2016-08-01

    Newtonian spherically symmetric transonic accretion is studied by including the mass of the accreting matter, while considering the growth of the accretor itself to be negligibly small. A novel iterative method is introduced to accomplish that task. It is demonstrated that the inclusion of the mass of the fluid changes the critical properties of the flow as well as the topological phase portraits of the stationary integral solution. The changes are small in the framework of this methodology. It is shown that to get large changes one has to develop a new method.

  3. Flow phenomena in turbomachines

    NASA Astrophysics Data System (ADS)

    Creitzer, E. M.; Epstein, A. H.; Giles, M. B.; McCune, J. E.; Tan, C. S.

    1993-01-01

    This report describes work carried out at the Gas Turbine Laboratory at MIT during the period 10/20/89 - 10/19/92, as part of our multi-investigator effort on basic unsteady flow phenomena in turbomachines. Within the overall project four separate tasks are specified. These are, in brief: (1) The Influence of Inlet Temperature Nonuniformities on Turbine Heat Transfer and Dynamics; (2) Assessment of Unsteady Losses in Stator/ Rotor Interactions; (3) Unsteady Phenomena and Flowfield instabilities in Multistage Axial Compressors; (4) Vortex Wake-Compressor Blade Interaction in Cascades - A New Rapid Method for Unsteady Separation and Vorticity Flux Calculations.

  4. Heat flow in structures

    SciTech Connect

    Burrer, G.J.

    1980-01-01

    Heat is transferred through a wall structure by the mechanisms of conduction, convection, and radiation. These mechanisms are introduced and developed in terms of their thermal resistances. Temperature difference is identified as the cause of heat flow through the structure which is impeded by the thermal resistances of the structures. Calculations are made of the thermal resistances at several points in a specific test wall section. The performance predicted from these calculations is compared to thermographic measurements made on the wall under laboratory controlled conditions. These comparisons are used to draw conclusions as to the usefulness and limitations of thermographic practices.

  5. Cell adhesion under flow.

    PubMed

    Ley, Klaus

    2009-01-01

    Cell adhesion under flow is a central function of the microcirculation during inflammation, hemostasis, and immune regulation. This special issue of Microcirculation explores the common and distinct mechanisms that myeloid cells, lymphocytes, platelets, and sickle erythrocytes use to adhere to microvascular endothelium and the underlying basement membrane structures. A common theme in these processes is the need for rapid integrin activation, often initiated by binding of ligands to their cognate G protein-coupled receptors, followed by adhesion strengthening associated with integrin redistribution and outside-in signaling. These elements have been identified for all cells tested except sickle erythrocytes.

  6. Cash flow management.

    PubMed

    Kamenetzky, S A

    1993-06-01

    In the face of decreasing reimbursement and increasing expenses, careful cash flow management has assumed an increasingly important role in developing and maintaining a successful ophthalmology practice. Funds must be collected as promptly and efficiently as possible, and retained and invested until needed by the practice to pay expenses. Office collection techniques and suggestions for dealing with third-party payers are presented. Managed care contracting and the inherent risks involved are discussed. Advice on accounts payable management is provided, and suggestions for investment of idle funds are outlined. This information should allow the formulation of a practical plan to maximize profitability in each ophthalmology practice.

  7. Disorders of lymph flow.

    PubMed

    Witte, C L; Witte, M H

    1995-04-01

    Disturbances in blood capillary exchange of fluid, macromolecules, and cells across intact and abnormal microvessels and deranged lymphatic transport are integral, interacting components in disorders of tissue swelling. Lymphedema or low-output failure of the lymph circulation is often indolent for many years before lymphatic insufficiency (failure) and tissue swelling emerge and persist. Superimposed occult or overt infection (lymphangitis) are probably major contributors to progressive limb deformity (elephantiasis). Long-standing lymphedema is characterized by trapping in the skin and subcutaneous tissue of fluid, extravasated plasma proteins, and other macromolecules: impaired immune cell trafficking; abnormal processing of autologous and foreign antigens; heightened susceptibility to superimposed infection; local immunodysregulation; defective lymphatic (lymphangion) propulsion from an imbalance of mediators regulating vasomotion; soft-tissue overgrowth; scarring and hypertrophy; and exuberant angiogenesis occasionally culminating in vascular tumors (Fig. 8). In contrast to the blood circulation, where flow depends primarily on the propulsive force of the myocardium, lymph propulsion depends predominately on intrinsic truncal contraction, a phylogenetic vestige of amphibian lymph hearts. Whereas venous "plasma" flows rapidly (2-3 l/min) against low vascular resistance, lymph flows slowly (1-2 ml/min) against high vascular resistance. On occasion, impaired transport of intestinal lymph may be associated with reflux and accumulation and leakage of intestinal chyle in a swollen leg. Although the term "lymphedema" is usually reserved for extremity swelling, the pathogenesis of a wide variety of visceral disorders also may be traceable to defective tissue fluid and macromolecular circulation and impaired cell trafficking of lymphocytes and macrophages. Thus, lymph stasis, with impaired tissue fluid flow, underlies or complicates an indolent subclinical course with

  8. Resting cerebral blood flow

    PubMed Central

    Ances, B M.; Sisti, D; Vaida, F; Liang, C L.; Leontiev, O; Perthen, J E.; Buxton, R B.; Benson, D; Smith, D M.; Little, S J.; Richman, D D.; Moore, D J.; Ellis, R J.

    2009-01-01

    Objective: HIV enters the brain soon after infection causing neuronal damage and microglial/astrocyte dysfunction leading to neuropsychological impairment. We examined the impact of HIV on resting cerebral blood flow (rCBF) within the lenticular nuclei (LN) and visual cortex (VC). Methods: This cross-sectional study used arterial spin labeling MRI (ASL-MRI) to measure rCBF within 33 HIV+ and 26 HIV− subjects. Nonparametric Wilcoxon rank sum test assessed rCBF differences due to HIV serostatus. Classification and regression tree (CART) analysis determined optimal rCBF cutoffs for differentiating HIV serostatus. The effects of neuropsychological impairment and infection duration on rCBF were evaluated. Results: rCBF within the LN and VC were significantly reduced for HIV+ compared to HIV− subjects. A 2-tiered CART approach using either LN rCBF ≤50.09 mL/100 mL/min or LN rCBF >50.09 mL/100 mL/min but VC rCBF ≤37.05 mL/100 mL/min yielded an 88% (29/33) sensitivity and an 88% (23/26) specificity for differentiating by HIV serostatus. HIV+ subjects, including neuropsychologically unimpaired, had reduced rCBF within the LN (p = 0.02) and VC (p = 0.001) compared to HIV− controls. A temporal progression of brain involvement occurred with LN rCBF significantly reduced for both acute/early (<1 year of seroconversion) and chronic HIV-infected subjects, whereas rCBF in the VC was diminished for only chronic HIV-infected subjects. Conclusion: Resting cerebral blood flow (rCBF) using arterial spin labeling MRI has the potential to be a noninvasive neuroimaging biomarker for assessing HIV in the brain. rCBF reductions that occur soon after seroconversion possibly reflect neuronal or vascular injury among HIV+ individuals not yet expressing neuropsychological impairment. GLOSSARY AEH = acute/early HIV infection; ANOVA = analysis of variance; ASL-MRI = arterial spin labeling MRI; CART = classification and regression tree; CBF = cerebral blood flow; CH = chronic HIV

  9. WET SOLIDS FLOW ENHANCEMENT

    SciTech Connect

    Hugo S. Caram; Natalie Foster

    1997-03-31

    The objective was to visualize the flow of granular materials in flat bottomed silo. This was done by for dry materials introducing mustard seeds and poppy seeds as tracer particles and imaging them using Nuclear Magnetic Resonance. The region sampled was a cylinder 25 mm in diameter and 40 mm in length. Eight slices containing 128*128 to 256*256 pixels were generated for each image. The size of the silo was limited by the size of the high resolution NMR imager available. Cross-sections of 150mm flat bottomed silos, with the tracer layers immobilized by a gel, showed similar qualitative patterns for both dry and wet granular solids.

  10. Bacterial suspensions under flow

    NASA Astrophysics Data System (ADS)

    Clement, Eric; Lindner, Anke; Douarche, Carine; Auradou, Harold

    2016-11-01

    Fluids laden with motile bacteria enter in the category of active matter, a new field currently developing at the convergence of biology, hydrodynamics and statistical physics. Such suspensions were shown recently to exhibit singular macroscopic transport properties. In this paper we review some recent results, either theoretical or experimental, on the active fluid rheology. We focus principally on bacteria suspensions and the objective is to provide the basis for understanding the emergence of the singular constitutive relations characterizing the macroscopic transport properties of such an active fluid under flow.

  11. Continuous information flow fluctuations

    NASA Astrophysics Data System (ADS)

    Rosinberg, Martin Luc; Horowitz, Jordan M.

    2016-10-01

    Information plays a pivotal role in the thermodynamics of nonequilibrium processes with feedback. However, much remains to be learned about the nature of information fluctuations in small-scale devices and their relation with fluctuations in other thermodynamics quantities, like heat and work. Here we derive a series of fluctuation theorems for information flow and partial entropy production in a Brownian particle model of feedback cooling and extend them to arbitrary driven diffusion processes. We then analyze the long-time behavior of the feedback-cooling model in detail. Our results provide insights into the structure and origin of large deviations of information and thermodynamic quantities in autonomous Maxwell's demons.

  12. CARMENES: data flow

    NASA Astrophysics Data System (ADS)

    Caballero, J. A.; Guàrdia, J.; López del Fresno, M.; Zechmeister, M.; de Juan, E.; Alonso-Floriano, F. J.; Amado, P. J.; Colomé, J.; Cortés-Contreras, M.; García-Piquer, Á.; Gesa, L.; de Guindos, E.; Hagen, H.-J.; Helmling, J.; Hernández Castaño, L.; Kürster, M.; López-Santiago, J.; Montes, D.; Morales Muñoz, R.; Pavlov, A.; Quirrenbach, A.; Reiners, A.; Ribas, I.; Seifert, W.; Solano, E.

    2016-07-01

    CARMENES, the new Calar Alto spectrograph especially built for radial-velocity surveys of exoearths around M dwarfs, is a very complicated system. For reaching the goal of 1 m/s radial-velocity accuracy, it is appropriate not only to monitor stars with the best observing procedure, but to monitor also the parameters of the CARMENES subsystems and safely store all the engineer and science data. Here we describe the CARMENES data flow from the different subsystems, through the instrument control system and pipeline, to the virtual-observatory data server and astronomers.

  13. Potential flow in engine valves

    NASA Technical Reports Server (NTRS)

    Eck, Bruno

    1925-01-01

    The extensive applicability of the hydrodynamic theory to the problems of engine construction is clearly shown in the following attempt to determine by exact methods the nature of the flow in valves under variously restricted conditions. Observation shows that two principal kinds of flow occur in simple flat-seated valves. For small valve lifts, the flow is along the horizontal wall and is therefore deflected 90 degrees, but for greater valve lifts the flow separates and forms a free stream, whose angle of deflection naturally increases with increasing lift. Both these kinds of flow can, in fact, be theoretically explained

  14. On flows having constant vorticity

    NASA Astrophysics Data System (ADS)

    Roberts, Paul H.; Wu, Cheng-Chin

    2011-10-01

    Constant vorticity flows of a uniform fluid in a rigid ellipsoidal container rotating at a variable rate are considered. These include librationally driven and precessionally driven flows. The well-known Poincaré solution for precessionally driven flow in a spheroid is generalized to an ellipsoid with unequal principal axes. The dynamic stability of these flows is investigated, and of other flows in which the angular velocity of the container is constant in time. Solutions for the Chandler wobble are discussed. The role of an invariant, called here the Helmholtzian, is examined.

  15. Heat exchanger with oscillating flow

    NASA Technical Reports Server (NTRS)

    Scotti, Stephen J. (Inventor); Blosser, Max L. (Inventor); Camarda, Charles J. (Inventor)

    1993-01-01

    Various heat exchange apparatuses are described in which an oscillating flow of primary coolant is used to dissipate an incident heat flux. The oscillating flow may be imparted by a reciprocating piston, a double action twin reciprocating piston, fluidic oscillators or electromagnetic pumps. The oscillating fluid flows through at least one conduit in either an open loop or a closed loop. A secondary flow of coolant may be used to flow over the outer walls of at least one conduit to remove heat transferred from the primary coolant to the walls of the conduit.

  16. Heat exchanger with oscillating flow

    NASA Technical Reports Server (NTRS)

    Scotti, Stephen J. (Inventor); Blosser, Max L. (Inventor); Camarda, Charles J. (Inventor)

    1992-01-01

    Various heat exchange apparatuses are described in which an oscillating flow of primary coolant is used to dissipate an incident heat flux. The oscillating flow may be imparted by a reciprocating piston, a double action twin reciprocating piston, fluidic oscillators, or electromagnetic pumps. The oscillating fluid flows through at least one conduit in either an open loop or a closed loop. A secondary flow of coolant may be used to flow over the outer walls of at least one conduit to remove heat transferred from the primary coolant to the walls of the conduit.

  17. Lunar ash flows - Isothermal approximation.

    NASA Technical Reports Server (NTRS)

    Pai, S. I.; Hsieh, T.; O'Keefe, J. A.

    1972-01-01

    Suggestion of the ash flow mechanism as one of the major processes required to account for some features of lunar soil. First the observational background and the gardening hypothesis are reviewed, and the shortcomings of the gardening hypothesis are shown. Then a general description of the lunar ash flow is given, and a simple mathematical model of the isothermal lunar ash flow is worked out with numerical examples to show the differences between the lunar and the terrestrial ash flow. The important parameters of the ash flow process are isolated and analyzed. It appears that the lunar surface layer in the maria is not a residual mantle rock (regolith) but a series of ash flows due, at least in part, to great meteorite impacts. The possibility of a volcanic contribution is not excluded. Some further analytic research on lunar ash flows is recommended.

  18. Ground vortex flow field investigation

    NASA Technical Reports Server (NTRS)

    Kuhn, Richard E.; Delfrate, John H.; Eshleman, James E.

    1988-01-01

    Flow field investigations were conducted at the NASA Ames-Dryden Flow Visualization Facility (water tunnel) to investigate the ground effect produced by the impingement of jets from aircraft nozzles on a ground board in a STOL operation. Effects on the overall flow field with both a stationary and a moving ground board were photographed and compared with similar data found in other references. Nozzle jet impingement angles, nozzle and inlet interaction, side-by-side nozzles, nozzles in tandem, and nozzles and inlets mounted on a flat plate model were investigated. Results show that the wall jet that generates the ground effect is unsteady and the boundary between the ground vortex flow field and the free-stream flow is unsteady. Additionally, the forward projection of the ground vortex flow field with a moving ground board is one-third less than that measured over a fixed ground board. Results also showed that inlets did not alter the ground vortex flow field.

  19. Monolithic Continuous-Flow Bioreactors

    NASA Technical Reports Server (NTRS)

    Stephanopoulos, Gregory; Kornfield, Julia A.; Voecks, Gerald A.

    1993-01-01

    Monolithic ceramic matrices containing many small flow passages useful as continuous-flow bioreactors. Ceramic matrix containing passages made by extruding and firing suitable ceramic. Pores in matrix provide attachment medium for film of cells and allow free movement of solution. Material one not toxic to micro-organisms grown in reactor. In reactor, liquid nutrients flow over, and liquid reaction products flow from, cell culture immobilized in one set of channels while oxygen flows to, and gaseous reaction products flow from, culture in adjacent set of passages. Cells live on inner surfaces containing flowing nutrient and in pores of walls of passages. Ready access to nutrients and oxygen in channels. They generate continuous high yield characteristic of immobilized cells, without large expenditure of energy otherwise incurred if necessary to pump nutrient solution through dense biomass as in bioreactors of other types.

  20. Monolithic Continuous-Flow Bioreactors

    NASA Technical Reports Server (NTRS)

    Stephanopoulos, Gregory; Kornfield, Julia A.; Voecks, Gerald A.

    1993-01-01

    Monolithic ceramic matrices containing many small flow passages useful as continuous-flow bioreactors. Ceramic matrix containing passages made by extruding and firing suitable ceramic. Pores in matrix provide attachment medium for film of cells and allow free movement of solution. Material one not toxic to micro-organisms grown in reactor. In reactor, liquid nutrients flow over, and liquid reaction products flow from, cell culture immobilized in one set of channels while oxygen flows to, and gaseous reaction products flow from, culture in adjacent set of passages. Cells live on inner surfaces containing flowing nutrient and in pores of walls of passages. Ready access to nutrients and oxygen in channels. They generate continuous high yield characteristic of immobilized cells, without large expenditure of energy otherwise incurred if necessary to pump nutrient solution through dense biomass as in bioreactors of other types.

  1. Blood flow in abdominal aortic aneurysms: pulsatile flow hemodynamics.

    PubMed

    Finol, E A; Amon, C H

    2001-10-01

    Numerical predictions of blood flow patterns and hemodynamic stresses in Abdominal Aortic Aneurysms (AAAs) are performed in a two-aneurysm, axisymmetric, rigid wall model using the spectral element method. Physiologically realistic aortic blood flow is simulated under pulsatile conditions for the range of time-averaged Reynolds numbers 50< or =Re(m)< or =300, corresponding to a range of peak Reynolds numbers 262.5< or =Re(peak) < or = 1575. The vortex dynamics induced by pulsatile flow in AAAs is characterized by a sequence of five different flow phases in one period of the flow cycle. Hemodynamic disturbance is evaluated for a modified set of indicator functions, which include wall pressure (p(w)), wall shear stress (tau(w)), and Wall Shear Stress Gradient (WSSG). At peak flow, the highest shear stress and WSSG levels are obtained downstream of both aneurysms, in a pattern similar to that of steady flow. Maximum values of wall shear stresses and wall shear stress gradients obtained at peak flow are evaluated as a function of the time-average Reynolds number resulting in a fourth order polynomial correlation. A comparison between predictions for steady and pulsatile flow is presented, illustrating the importance of considering time-dependent flow for the evaluation of hemodynamic indicators.

  2. Prediction of Geophysical Flow Mobility

    NASA Astrophysics Data System (ADS)

    Cagnoli, B.; Piersanti, A.

    2014-12-01

    The prediction of the mobility of geophysical flows to assess their hazards is one of the main research goals in the earth sciences. Our laboratory experiments and numerical simulations are carried out to understand the effects of grain size and flow volume on the mobility of the centre of mass of dry granular flows of angular rock fragments that have pyroclastic flows and rock avalanches as counterpart in nature. We focus on the centre of mass because it provides information about the intrinsic ability of a flow to dissipate more or less energy as a function of its own features. We show that the grain size and flow volume effects can be expressed by a linear relationship between scaling parameters where the finer the grain size or the smaller the flow volume, the more mobile the centre of mass of the granular flow. The grain size effect is the result of the decrease of particle agitation per unit of flow mass, and thus, the decrease of energy dissipation per unit of travel distance, as grain size decreases. In this sense, flows with different grain sizes are like cars with engines with different fuel efficiencies. The volume effect is the result of the fact that the deposit accretes backward during its formation on a slope change (either gradual or abrupt). We adopt for the numerical simulations a 3D discrete element modeling which confirms the grain size and flow volume effects shown by the laboratory experiments. This confirmation is obtained without prior fine tuning of the parameter values to get the desired output. The numerical simulations reveal also that the larger the initial compaction of the granular mass before release, the more mobile the flow. This behaviour must be taken into account to prevent misinterpretation of laboratory and field data. Discrete element modeling predicts the correct effects of grain size and flow volume because it takes into consideration particle interactions that are responsible for the energy dissipated by the flows.

  3. UZ Flow Models and Submodels

    SciTech Connect

    Y. Wu

    2004-11-01

    The purpose of this report is to document the unsaturated zone (UZ) flow models and submodels, as well as the flow fields that have been generated using the UZ flow model(s) of Yucca Mountain, Nevada. In this report, the term ''UZ model'' refers to the UZ flow model and the several submodels, which include tracer transport, temperature or ambient geothermal, pneumatic or gas flow, and geochemistry (chloride, calcite, and strontium) submodels. The term UZ flow model refers to the three-dimensional models used for calibration and simulation of UZ flow fields. This work was planned in the ''Technical Work Plan (TWP) for: Unsaturated Zone Flow Analysis and Model Report Integration'' (BSC 2004 [DIRS 169654], Section 1.2.7). The table of included Features, Events, and Processes (FEPs), Table 6.2-11, is different from the list of included FEPs assigned to this report in the ''Technical Work Plan for: Unsaturated Zone Flow Analysis and Model Report Integration'' (BSC 2004 [DIRS 169654], Table 2.1.5-1), as discussed in Section 6.2.6. The UZ model has revised, updated, and enhanced the previous UZ model (BSC 2001 [DIRS 158726]) by incorporating the repository design with new grids, recalibration of property sets, and more comprehensive validation effort. The flow fields describe fracture-fracture, matrix-matrix, and fracture-matrix liquid flow rates, and their spatial distributions as well as moisture conditions in the UZ system. These three-dimensional UZ flow fields are used directly by Total System Performance Assessment (TSPA). The model and submodels evaluate important hydrogeologic processes in the UZ as well as geochemistry and geothermal conditions. These provide the necessary framework to test hypotheses of flow and transport at different scales, and predict flow and transport behavior under a variety of climatic conditions. In addition, the limitations of the UZ model are discussed in Section 8.11.

  4. Lava Flows in Eastern Tharsis

    NASA Technical Reports Server (NTRS)

    2002-01-01

    (Released 31 May 2002) This image may at first appear somewhat bland -- there is little contrast in the surface materials due to dust cover, and there are few impact craters -- but there are some very interesting geologic features here. The great Tharsis volcanoes have produced vast fields of lava flows, such as those shown in this image, to the east of Tharsis Tholus. The flows in this image have moved from west to east, down the regional topographic slope. The lobate edges of the flows are distinctive, and permit the discrimination of many overlapping individual flows that may represent tens, hundreds, thousands, or even millions of years worth of volcanic activity (overlapping relationships are especially evident at the bottom of the image). Viewed at full resolution, the image reveals interesting patterns and textures on the top surfaces of these flows. In particular, at the top of the image, there are numerous parallel curved ridges visible on the upper surfaces of the lava flows. These ridges make the flow surface look somewhat ropy, and at smaller scales this flow might be referred to as pahoehoe, indicative of a relatively fluid type of lava flow. At the scales observed here, however, these features are probably better referred to as pressure ridges. Pressure ridges form on the surface of a lava flow when the upper part of the flow is exposed to air, freezing it, but the insulated unfrozen interior of the flow continues to move down slope (and more material is pushed forward from behind), causing the surface to compress and pile up like a rug. Rough-looking flows with less distinct (more random) patterns on their surfaces may be flows that are more like terrestrial a'a flows, which are distinguished from pahoehoe flows by their higher viscosities and effusion rates. Near the center of the image there is an east-west trending, smooth-floored depression. The somewhat continuous width of this depression suggests that it is not simply formed by the edges of two

  5. Annular flow diverter valve

    DOEpatents

    Rider, Robert L.

    1980-01-01

    A valve for diverting flow from the center of two concentric tubes to the annulus between the tubes or, operating in the reverse direction, for mixing fluids from concentric tubes into a common tube and for controlling the volume ratio of said flow consists of a toroidal baffle disposed in sliding engagement with the interior of the inner tube downstream of a plurality of ports in the inner tube, a plurality of gates in sliding engagement with the interior of the inner tube attached to the baffle for movement therewith, a servomotor having a bullet-shaped plug on the downstream end thereof, and drive rods connecting the servomotor to the toroidal baffle, the servomotor thereby being adapted to move the baffle into mating engagement with the bullet-shaped plug and simultaneously move the gates away from the ports in the inner tube and to move the baffle away from the bullet-shaped plug and simultaneously move the gates to cover the ports in the inner tube.

  6. Wellhead flow control devices

    SciTech Connect

    McLean, D.K.

    1981-09-15

    A wellhead flow control device includes a main flow control valve and associated packings designed for operation under extreme conditions associated with the pumping of high viscosity asphaltic crude wherein the formation includes toxic gases. The formation is produced using steam flooding techniques. The main valve seat and the associated valve closure, consisting of a reciprocating ram and packing plug, are coaxial with the pump polished rod. The valve seat icludes tapered walls defining a shoulder which partially confronts the ram plug. The ram plug is formed of a compressible material formed to the shape of the valve seat. The packing plug is retained on the end of the ram by axial tie rods and a retaining ring. The ring may engage the valve seat shoulder to effect axial compression of the packing plug between the retaining ring and ram face, with consequent radial expansion into the sealing engagement. The ram is reciprocated axially, either manually or hydraulically relative to the ram body. A packing gland, suitable to seal against toxic gases, is provided between the ram and valve body. A rod packing, at the upper end of the ram, includes a primary adjustable packing gland for sealing between the ram and the reciprocating polished rod. 41 claims.

  7. Active flows on trees

    NASA Astrophysics Data System (ADS)

    Forrow, Aden; Woodhouse, Francis G.; Dunkel, Jörn

    2016-11-01

    Coherent, large scale dynamics in many nonequilibrium physical, biological, or information transport networks are driven by small-scale local energy input. We introduce and explore a generic model for compressible active flows on tree networks. In contrast to thermally-driven systems, active friction selects discrete states with only a small number of oscillation modes activated at distinct fixed amplitudes. This state selection can interact with graph topology to produce different localized dynamical time scales in separate regions of large networks. Using perturbation theory, we systematically predict the stationary states of noisy networks. Our analytical predictions agree well with a Bayesian state estimation based on a hidden Markov model applied to simulated time series data on binary trees. While the number of stable states per tree scales exponentially with the number of edges, the mean number of activated modes in each state averages 1 / 4 the number of edges. More broadly, these results suggest that the macroscopic response of active networks, from actin-myosin networks in cells to flow networks in Physarum polycephalum, can be dominated by a few select modes.

  8. AC Optimal Power Flow

    SciTech Connect

    2016-10-04

    In this work, we have implemented and developed the simulation software to implement the mathematical model of an AC Optimal Power Flow (OPF) problem. The objective function is to minimize the total cost of generation subject to constraints of node power balance (both real and reactive) and line power flow limits (MW, MVAr, and MVA). We have currently implemented the polar coordinate version of the problem. In the present work, we have used the optimization solver, Knitro (proprietary and not included in this software) to solve the problem and we have kept option for both the native numerical derivative evaluation (working satisfactorily now) as well as for analytical formulas corresponding to the derivatives being provided to Knitro (currently, in the debugging stage). Since the AC OPF is a highly non-convex optimization problem, we have also kept the option for a multistart solution. All of these can be decided by the user during run-time in an interactive manner. The software has been developed in C++ programming language, running with GCC compiler on a Linux machine. We have tested for satisfactory results against Matpower for the IEEE 14 bus system.

  9. Internal Surface Water Flows

    USGS Publications Warehouse

    Murray, Mitchell H.

    1999-01-01

    Introduction The South Florida Ecosystem Restoration Program is an intergovernmental effort to reestablish and maintain the ecosystem of south Florida. One element of the restoration effort is the development of a firm scientific basis for resource decision making.The U.S. Geological Survey (USGS) provides scientitic information as part of the South Florida Ecosystem Restoration Program. The USGS began its own project, called the South Florida Ecosystem Project in fiscal year 1995 for the purpose of gathering hydrologic, cartographic, and geologic data that relate to the mainland of south Florida, Florida Bay, and the Florida Keys and Reef ecosystems. Historical changes in water-management practices to accommodate a large and rapidly growing urban population along the Atlantic coast, as well as intensive agricultural activities, have resulted in a highly managed hydrologic system with canals, levees, and pumping stations. These structures have altered the hydology of the Everglades ecosystem on both coastal and interior lands. Surface-water flows in a direction south of Lake Okeechobee have been regulated by an extensive canal network, begun in the 1940's, to provide for drainage, flood control, saltwater intrusion control, agricultural requirements, and various environmental needs. Much of the development and subsequent monitoring of canal and river discharge south of Lake Okeechobee has traditionally emphasized the eastern coastal areas of Florida. Recently, more emphasis has been placed on providing a more accurate water budget for internal canal flows.

  10. Radial flow heat exchanger

    DOEpatents

    Valenzuela, Javier

    2001-01-01

    A radial flow heat exchanger (20) having a plurality of first passages (24) for transporting a first fluid (25) and a plurality of second passages (26) for transporting a second fluid (27). The first and second passages are arranged in stacked, alternating relationship, are separated from one another by relatively thin plates (30) and (32), and surround a central axis (22). The thickness of the first and second passages are selected so that the first and second fluids, respectively, are transported with laminar flow through the passages. To enhance thermal energy transfer between first and second passages, the latter are arranged so each first passage is in thermal communication with an associated second passage along substantially its entire length, and vice versa with respect to the second passages. The heat exchangers may be stacked to achieve a modular heat exchange assembly (300). Certain heat exchangers in the assembly may be designed slightly differently than other heat exchangers to address changes in fluid properties during transport through the heat exchanger, so as to enhance overall thermal effectiveness of the assembly.

  11. Olympus Mons Flows

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site] Context image for PIA03633 Olympus Mons Flows

    This image shows the massive Olympus Mons flows at the basal escarpment.

    Image information: VIS instrument. Latitude 14.9S, Longitude 229.1E. 18 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  12. Birkeland current boundary flows

    NASA Astrophysics Data System (ADS)

    Archer, W. E.; Knudsen, D. J.; Burchill, J. K.; Jackel, B.; Donovan, E.; Connors, M.; Juusola, L.

    2017-04-01

    Intense zonal ion velocity jets in the northern nightside auroral zone are measured during quiet geomagnetic conditions by the Swarm satellites around 500 km altitude. These velocity jets, exceeding 1 km/s in over 50% of orbits measured, range from 20 to 100 km in meridional thickness and reach a maximum at the boundary between upward and downward field-aligned current. On average they represent a potential difference of approximately 3 kV between the R1/R2 currents. This boundary also separates different regions of electron temperature and meridional flow and is associated with ion upflows and anisotropic heating. Both dawnward and duskward velocity jets are observed, including some oppositely directed pairs bounding regions of upward field-aligned current. Coincident ground-based observations place ion velocity jets adjacent to auroral arcs, embedded in the auroral electrojets. Previous literature has focused on fast flows occurring in regions of relative low conductivity surrounding auroral arcs, typically during geomagnetically active conditions, and does not address the occurrence frequency of these events. We show ion velocity jets to be a persistent and ubiquitous property of the electrodynamics of quiet time R1/R2 current closure near midnight in the winter hemisphere.

  13. Fluid flow monitoring device

    DOEpatents

    McKay, Mark D.; Sweeney, Chad E.; Spangler, Jr., B. Samuel

    1993-01-01

    A flow meter and temperature measuring device comprising a tube with a body centered therein for restricting flow and a sleeve at the upper end of the tube to carry several channels formed longitudinally in the sleeve to the appropriate axial location where they penetrate the tube to allow pressure measurements and temperature measurements with thermocouples. The high pressure measurement is made using a channel penetrating the tube away from the body and the low pressure measurement is made at a location at the widest part of the body. An end plug seals the end of the device and holes at its upper end allow fluid to pass from the interior of the tube into a plenum. The channels are made by cutting grooves in the sleeve, the grooves widened at the surface of the sleeve and then a strip of sleeve material is welded to the grooves closing the channels. Preferably the sleeve is packed with powdered graphite before cutting the grooves and welding the strips.

  14. Ellipsoidal cell flow system

    DOEpatents

    Salzman, Gary C.; Mullaney, Paul F.

    1976-01-01

    The disclosure relates to a system incorporating an ellipsoidal flow chamber having light reflective walls for low level light detection in practicing cellular analysis. The system increases signal-to-noise ratio by a factor of ten over prior art systems. In operation, laser light passes through the primary focus of the ellipsoid. A controlled flow of cells simultaneously passes through this focus so that the laser light impinges on the cells and is modulated by the cells. The reflective walls of the ellipsoid reflect the cell-modulated light to the secondary focus of the ellipsoid. A tapered light guide at the secondary focus picks up a substantial portion of modulated reflective light and directs it onto a light detector to produce a signal. The signal is processed to obtain the intensity distribution of the modulated light and hence sought after characteristics of the cells. In addition, cells may be dyed so as to fluoresce in response to the laser light and their fluorescence may be processed as cell-modulated light above described. A light discriminating filter would be used to distinguish reflected modulated laser light from reflected fluorescent light.

  15. Gaseous Flows in Microchannels

    NASA Astrophysics Data System (ADS)

    Graur, I. A.; Méolans, J. G.; Zeitoun, D. E.

    2005-05-01

    The objective of this study is to broaden the fundamental understanding of the emerging field of microfluidics especially in a long channel. The quasi gasdynamic (QGD) equations, originally developed on the basis of a kinetical model are used for numerical and analytical simulation. A two-dimensional analysis of the QGD equations with a first order slip velocity boundary conditions demonstrates that both compressibility and rarefied effects are present in long microchannels. Analytical solutions for the pressure and the velocity profiles are derived from the quasi gasdynamic equations by undertaking perturbation expansions according to a small parameter ɛ (the height-to-length ratio of the channel) and using the isothermal flow assumption. The deduced expression for the mass flow rate is similar to the analytical expression obtained from the Navier-Stokes equations with a second order slip boundary condition and gives results in agreement with the measurements. The effects of the rarefaction and of the compressibility on pressure distributions are analyzed. The analytical expression of the pressure predicts accurately the measured pressure distribution. The Knudsen numbers calculated at the exit of the channel and based on the channel height vary from 10-3 to 0.4. The comparisons of analytical and numerical solutions confirm the validity of the analytical approach.

  16. Blood flow and microgravity

    NASA Astrophysics Data System (ADS)

    Bureau, Lionel; Coupier, Gwennou; Dubois, Frank; Duperray, Alain; Farutin, Alexander; Minetti, Christophe; Misbah, Chaouqi; Podgorski, Thomas; Tsvirkun, Daria; Vysokikh, Mikhail

    2017-01-01

    The absence of gravity during space flight can alter cardio-vascular functions partially due to reduced physical activity. This affects the overall hemodynamics, and in particular the level of shear stresses to which blood vessels are submitted. Long-term exposure to space environment is thus susceptible to induce vascular remodeling through a mechanotransduction cascade that couples vessel shape and function with the mechanical cues exerted by the circulating cells on the vessel walls. Central to such processes, the glycocalyx - i.e. the micron-thick layer of biomacromolecules that lines the lumen of blood vessels and is directly exposed to blood flow - is a major actor in the regulation of biochemical and mechanical interactions. We discuss in this article several experiments performed under microgravity, such as the determination of lift force and collective motion in blood flow, and some preliminary results obtained in artificial microfluidic circuits functionalized with endothelium that offer interesting perspectives for the study of the interactions between blood and endothelium in healthy condition as well as by mimicking the degradation of glycocalyx caused by long space missions. A direct comparison between experiments and simulations is discussed. xml:lang="fr"

  17. Transport in EHD flows distinct from HD and MHD flows

    NASA Astrophysics Data System (ADS)

    Kikuchi, H.

    2003-04-01

    EHD flows are typically composed of a charged (positively or negatively) fluid, though not all, that may be an electron fluid, an ion fluid or a dust fluid for a single fluid, or their mixtures for multi-component fluids in contrast to nonionized HD or plasma MHD flows. Electric or ponderomotive forces are newly exerted on EHD flows in addition to mechanical, viscous, and magnetic forces on HD and MHD flows. Accordingly, EHD flows hold electric pressure in addition to gas or plasma and magnetic pressure in HD and MHD flows. EHD flows hold space charge and displacement currents and are regarded as a dielectric or semiconducting fluid in contrast to nonionized HD flows or conducting plasma MHD flows. EHD flows are governed by a new equation of electric field transport in addition to fluid vortex transport (HD) and magnetic field transport (MHD), though their equations have to be supplemented by additional terms involving effects of space charge and electric fields, and are characterized by a new electric Reynolds number, R_E with spatial and temporal factors in addition to the fluid Reynolds number, R (spatial) and the magnetic Reynolds number, R_M (spatial) for HD and MHD flows. When R_E >> 1, however, the equation of electric field transport for EHD flows is reduced to the so-called Kelvin-Helmholtz equation just like equations of fluid vortex and magnetic field transport for R >> 1 for HD flows and R_M >> 1 for MHD flows. Accordingly, the EHD relation, H^* = H + v × .D ≈ 0 holds, analogous to the so-called MHD relation, E^* = E + v ×.B ≈ 0. In EHD flows, electric cusp or electrically neutral point can be formed as a bifurcation point of equipotential line or surface, analogous to a stagnation point in HD flows and magnetic cusp or separatrix in MHD flows. Accordingly, electric reconnection or space-charge related electric field line merging with particle acceleration or ionization due to critical velocity effects is possible in EHD flows, analogous to fluid

  18. Eddy Current Minimizing Flow Plug for Use in Flow Conditioning and Flow Metering

    NASA Technical Reports Server (NTRS)

    England, John Dwight (Inventor); Kelley, Anthony R. (Inventor)

    2015-01-01

    An eddy-current-minimizing flow plug has open flow channels formed between the plug's inlet and outlet. Each open flow channel includes (i) a first portion that originates at the inlet face and converges to a location within the plug that is downstream of the inlet, and (ii) a second portion that originates within the plug and diverges to the outlet. The diverging second portion is approximately twice the length of the converging first portion. The plug is devoid of planar surface regions at its inlet and outlet, and in fluid flow planes of the plug that are perpendicular to the given direction of a fluid flowing therethrough.

  19. Radioisotopic flow scanning for portal blood flow and portal hypertension

    SciTech Connect

    Hesdorffer, C.S.; Bezwoda, W.R.; Danilewitz, M.D.; Esser, J.D.; Tobias, M.

    1987-08-01

    The use of a simple, noninvasive, isotope scanning technique for the determination of relative portal blood flow and detection of portal hypertension is described. Using this technique the presence of portal hypertension was demonstrated in seven of nine patients known to have elevated portal venous pressure. By contrast, esophageal varices were demonstrated in only five of these patients, illustrating the potential value of the method. Furthermore, this technique has been adapted to the study of portal blood flow in patients with myeloproliferative disorders with splenomegaly but without disturbances in hepatic architecture. Results demonstrate that the high relative splenic flow resulting from the presence of splenomegaly may in turn be associated with elevated relative portal blood flow and portal hypertension. The theoretic reasons for the development of flow-related portal hypertension and its relationship to splenic blood flow are discussed.

  20. The sensitivity of stratified flow stability to base flow modifications

    NASA Astrophysics Data System (ADS)

    Chen, Kevin; Spedding, Geoffrey

    2016-11-01

    We present a novel theory that determines the sensitivity of linear stability to changes in the density or velocity of a base flow. The sensitivity is based on global direct and adjoint eigenmodes of the linearized Boussinesq equation, and is inspired by constant-density sensitivity analysis. The theory can be applied broadly to incompressible flows with small density variations, but it specifically provides new insight into the stability of density-stratified flows. Examples are given for the flows around a transverse thin plate at a Reynolds number of 30, a Prandtl number of 7.19, and Froude numbers of ∞ and 1. In the unstratified flow, the sensitivity is largest in the recirculation bubble; the stratified flow, however, exhibits high sensitivity in regions immediately upstream and downstream of the bluff body. Supported by the Viterbi Postdoctoral Fellowship, provided by the Viterbi School of Engineering at the University of Southern California.

  1. Positron Emission Tomography-Determined Hyperemic Flow, Myocardial Flow Reserve, and Flow Gradient—Quo Vadis?

    PubMed Central

    Leucker, Thorsten M.; Valenta, Ines; Schindler, Thomas Hellmut

    2017-01-01

    Positron emission tomography/computed tomography (PET/CT) applied with positron-emitting flow tracers such as 13N-ammonia and 82Rubidium enables the quantification of both myocardial perfusion and myocardial blood flow (MBF) in milliliters per gram per minute for coronary artery disease (CAD) detection and characterization. The detection of a regional myocardial perfusion defect during vasomotor stress commonly identifies the culprit lesion or most severe epicardial narrowing, whereas adding regional hyperemic MBFs, myocardial flow reserve (MFR), and/or longitudinal flow decrease may also signify less severe but flow-limiting stenosis in multivessel CAD. The addition of regional hyperemic flow parameters, therefore, may afford a comprehensive identification and characterization of flow-limiting effects of multivessel CAD. The non-specific origin of decreases in hyperemic MBFs and MFR, however, prompts an evaluation and interpretation of regional flow in the appropriate context with the presence of obstructive CAD. Conversely, initial results of the assessment of a longitudinal hyperemic flow gradient suggest this novel flow parameter to be specifically related to increases in CAD caused epicardial resistance. The concurrent assessment of myocardial perfusion and several hyperemic flow parameters with PET/CT may indeed open novel avenues of precision medicine to guide coronary revascularization procedures that may potentially lead to a further improvement in cardiovascular outcomes in CAD patients. PMID:28770213

  2. Flow Simulation of Solid Rocket Motors. 2; Sub-Scale Air Flow Simulation of Port Flows

    NASA Technical Reports Server (NTRS)

    Yeh, Y. P.; Ramandran, N.; Smith, A. W.; Heaman, J. P.

    2000-01-01

    The injection-flow issuing from a porous medium in the cold-flow simulation of internal port flows in solid rocket motors is characterized by a spatial instability termed pseudoturbulence that produces a rather non-uniform (lumpy) injection-velocity profile. The objective of this study is to investigate the interaction between the injection- and the developing axial-flows. The findings show that this interaction generally weakens the lumpy injection profile and affects the subsequent development of the axial flow. The injection profile is found to depend on the material characteristics, and the ensuing pseudoturbulence is a function of the injection velocity, the axial position and the distance from the porous wall. The flow transition (from laminar to turbulent) of the axial-flow is accelerated in flows emerging from smaller pores primarily due to the higher pseudoturbulence produced by the smaller pores in comparison to that associated with larger pores. In flows with rather uniform injection-flow profiles (weak or no pseudoturbulence), the axial and transverse velocity components in the porous duct are found to satisfy the sine/cosine analytical solutions derived from inviscid assumptions. The transition results from the present study are compared with previous results from surveyed literature, and detailed flow development measurements are presented in terms of the blowing fraction, and characterizing Reynolds numbers.

  3. FlowSim/FlowRisk: A code system for studying risk associated with material process flows

    SciTech Connect

    Kaufman, A.M.

    1993-10-01

    The need to study and assess life-cycle risks of Pu release by nuclear warheads during peace time lead to the development of a code suite which could model day to day operations involving nuclear weapons and calculate the associated risk involved in these proceedings. The life-cycle study called LIONSHARE is described in Reference 1. The code that models the flow is called FlowSim. The code that evaluates the associated risk is called FlowRisk. We shall concentrate here on the methodology used by FlowSim in modeling material flows. FlowRisk, mainly a postprocessor of FlowSim runs, will be dealt with in less detail.

  4. Graphics and Flow Visualization of Computer Generated Flow Fields

    NASA Technical Reports Server (NTRS)

    Kathong, M.; Tiwari, S. N.

    1987-01-01

    Flow field variables are visualized using color representations described on surfaces that are interpolated from computational grids and transformed to digital images. Techniques for displaying two and three dimensional flow field solutions are addressed. The transformations and the use of an interactive graphics program for CFD flow field solutions, called PLOT3D, which runs on the color graphics IRIS workstation are described. An overview of the IRIS workstation is also described.

  5. High flow ceramic pot filters.

    PubMed

    van Halem, D; van der Laan, H; Soppe, A I A; Heijman, S G J

    2017-07-20

    Ceramic pot filters are considered safe, robust and appropriate technologies, but there is a general consensus that water revenues are limited due to clogging of the ceramic element. The objective of this study was to investigate the potential of high flow ceramic pot filters to produce more water without sacrificing their microbial removal efficacy. High flow pot filters, produced by increasing the rice husk content, had a higher initial flow rate (6-19 L h(-1)), but initial LRVs for E. coli of high flow filters was slightly lower than for regular ceramic pot filters. This disadvantage was, however, only temporarily as the clogging in high flow filters had a positive effect on the LRV for E. coli (from below 1 to 2-3 after clogging). Therefore, it can be carefully concluded that regular ceramic pot filters perform better initially, but after clogging, the high flow filters have a higher flow rate as well as a higher LRV for E. coli. To improve the initial performance of new high flow filters, it is recommended to further utilize residence time of the water in the receptacle, since additional E. coli inactivation was observed during overnight storage. Although a relationship was observed between flow rate and LRV of MS2 bacteriophages, both regular and high flow filters were unable to reach over 2 LRV. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Preserving Flow Variability in Watershed Model Calibrations

    EPA Science Inventory

    Background/Question/Methods Although watershed modeling flow calibration techniques often emphasize a specific flow mode, ecological conditions that depend on flow-ecology relationships often emphasize a range of flow conditions. We used informal likelihood methods to investig...

  7. Preserving Flow Variability in Watershed Model Calibrations

    EPA Science Inventory

    Background/Question/Methods Although watershed modeling flow calibration techniques often emphasize a specific flow mode, ecological conditions that depend on flow-ecology relationships often emphasize a range of flow conditions. We used informal likelihood methods to investig...

  8. Flow rate limitation in open capillary channel flows.

    PubMed

    Haake, Dennis; Rosendahl, Uwe; Ohlhoff, Antje; Dreyer, Michael E

    2006-09-01

    This paper reports the experimental and theoretical investigations of forced liquid flows through open capillary channels under reduced gravity conditions. An open capillary channel is a structure that establishes a liquid flow path at low Bond numbers, when the capillary pressure caused by the surface tension force dominates in comparison to the hydrostatic pressure induced by gravitational or residual accelerations. In case of steady flow through the channel, the capillary pressure of the free surface balances the pressure difference between the liquid and the surrounding constant-pressure gas phase. Because of convective and viscous momentum transport, the pressure along the flow path decreases and causes the free surface to bend inward. The maximum flow rate is achieved when the free surface collapses and gas ingestion occurs at the outlet. This critical flow rate depends on the geometry of the channel and the properties of the liquid. In this paper we present a comparison of the theoretical and experimental critical flow rates and surface profiles for convective dominated flows. For the prediction of the critical flow rate a one-dimensional theoretical model taking into account the entrance pressure loss and the frictional pressure loss in the channel is developed.

  9. Underestimation of access flow by ultrasound dilution flow measurements

    NASA Astrophysics Data System (ADS)

    Bos, Clemens; Smits, Johannes H. M.; Zijlstra, Jan J.; Blankestijn, Peter J.; Bakker, Chris J. G.; Viergever, Max A.

    2002-02-01

    For hemodialysis access surveillance, flow measurements are increasingly considered important because they identify accesses at risk of thrombosis. Usually these flow measurements are performed with the ultrasound dilution technique. In a previous patient study it was observed that the resulting flow values were systematically low as compared to magnetic resonance flow measurements, but a satisfactory explanation was lacking. In the present study, we will demonstrate by hemodynamic calculations and in vitro experiments that this discrepancy can be explained by a temporary reduction of the access flow rate, caused by the reversed needle configuration during ultrasound dilution flow measurements. In this configuration, blood is injected retrogressively at one needle and flow between the needles is increased, causing an increased dissipation of energy. The proposed explanation is subsequently confirmed in a patient with a loop graft, by measuring the blood velocity by Doppler ultrasound as a function of reversed dialyzer flow rate. Apart from the ultrasound dilution technique, these findings are applicable to other recently proposed methods for measuring access flow that employ the reversed needle configuration.

  10. Flow feature detection for grid adaptation and flow visualization

    NASA Astrophysics Data System (ADS)

    Kallinderis, Yannis; Lymperopoulou, Eleni M.; Antonellis, Panagiotis

    2017-07-01

    Adaptive grid refinement/coarsening is an important method for achieving increased accuracy of flow simulations with reduced computing resources. Further, flow visualization of complex 3-D fields is a major task of both computational fluid dynamics (CFD), as well as experimental data analysis. A primary issue of adaptive simulations and flow visualization is the reliable detection of the local regions containing features of interest. A relatively wide spectrum of detection functions (sensors) is employed for representative flow cases which include boundary layers, vortices, jets, wakes, shock waves, contact discontinuities, and expansions. The focus is on relatively simple sensors based on local flow field variation using 3-D general hybrid grids consisting of multiple types of elements. A quantitative approach for sensors evaluation and comparison is proposed and applied. It is accomplished via the employment of analytic flow fields. Automation and effectiveness of an adaptive grid or flow visualization process requires the reliable determination of an appropriate threshold for the sensor. Statistical evaluation of the distributions of the sensors results in a proposed empirical formula for the threshold. The qualified sensors along with the automatic threshold determination are tested with more complex flow cases exhibiting multiple flow features.

  11. Heat Flow Measurement

    NASA Technical Reports Server (NTRS)

    1993-01-01

    Heat gauges are used to measure heat flow in industrial activities. They must periodically be certified by instruments designed to provide a heat flux measurement standard. CSTAR, a NASA CCDS, and REMTECH have developed a portable heat flux checker/calibrator. The Q-CHEC can be carried to the heat gauge for certification, reducing out of service time for the gauge and eliminating the need for a replacement gauge during certification. It can provide an "end-to-end" check of the instrumentation measurement system or be used as a standalone calibrator. Because Q-CHEC offers on-site capability to detect and eliminate measurement errors, measurements do not have to be repeated, and money is saved.

  12. Space station data flow

    NASA Technical Reports Server (NTRS)

    1972-01-01

    The results of the space station data flow study are reported. Conceived is a low cost interactive data dissemination system for space station experiment data that includes facility and personnel requirements and locations, phasing requirements and implementation costs. Each of the experiments identified by the operating schedule is analyzed and the support characteristics identified in order to determine data characteristics. Qualitative and quantitative comparison of candidate concepts resulted in a proposed data system configuration baseline concept that includes a data center which combines the responsibility of reprocessing, archiving, and user services according to the various agencies and their responsibility assignments. The primary source of data is the space station complex which provides through the Tracking Data Relay Satellite System (TDRS) and by space shuttle delivery data from experiments in free flying modules and orbiting shuttles as well as from the experiments in the modular space station itself.

  13. Kauai Groundwater Flow Model

    SciTech Connect

    Nicole Lautze

    2015-01-01

    Groundwater flow model for Kauai. Data is from the following sources: Whittier, R. and A.I. El-Kadi. 2014. Human and Environmental Risk Ranking of Onsite Sewage Disposal Systems For the Hawaiian Islands of Kauai, Molokai, Maui, and Hawaii – Final. Prepared by the University of Hawaii, Dept. of Geology and Geophysics for the State of Hawaii Dept. of Health, Safe Drinking Water Branch. September 2014.; and Whittier, R.B., K. Rotzoll, S. Dhal, A.I. El-Kadi, C. Ray, G. Chen, and D. Chang. 2004. Hawaii Source Water Assessment Program Report – Volume IV – Island of Kauai Source Water Assessment Program Report. Prepared for the Hawaii Department of Health, Safe Drinking Water Branch. University of Hawaii, Water Resources Research Center. Updated 2015.

  14. Molecular vibrational energy flow

    NASA Astrophysics Data System (ADS)

    Gruebele, M.; Bigwood, R.

    This article reviews some recent work in molecular vibrational energy flow (IVR), with emphasis on our own computational and experimental studies. We consider the problem in various representations, and use these to develop a family of simple models which combine specific molecular properties (e.g. size, vibrational frequencies) with statistical properties of the potential energy surface and wavefunctions. This marriage of molecular detail and statistical simplification captures trends of IVR mechanisms and survival probabilities beyond the abilities of purely statistical models or the computational limitations of full ab initio approaches. Of particular interest is IVR in the intermediate time regime, where heavy-atom skeletal modes take over the IVR process from hydrogenic motions even upon X H bond excitation. Experiments and calculations on prototype heavy-atom systems show that intermediate time IVR differs in many aspects from the early stages of hydrogenic mode IVR. As a result, IVR can be coherently frozen, with potential applications to selective chemistry.

  15. Continuous flow photochemistry.

    PubMed

    Gilmore, Kerry; Seeberger, Peter H

    2014-06-01

    Due to the narrow width of tubing/reactors used, photochemistry performed in micro- and mesoflow systems is significantly more efficient than when performed in batch due to the Beer-Lambert Law. Owing to the constant removal of product and facility of flow chemical scalability, the degree of degradation observed is generally decreased and the productivity of photochemical processes is increased. In this Personal Account, we describe a wide range of photochemical transformations we have examined using both visible and UV light, covering cyclizations, intermolecular couplings, radical polymerizations, as well as singlet oxygen oxygenations. Copyright © 2014 The Chemical Society of Japan and Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Voltage correction power flow

    SciTech Connect

    Rajicic, D.; Ackovski, R.; Taleski, R. . Dept. of Electrical Engineering)

    1994-04-01

    A method for power flow solution of weakly meshed distribution and transmission networks is presented. It is based on oriented ordering of network elements. That allows an efficient construction of the loop impedance matrix and rational organization of the processes such as: power summation (backward sweep), current summation (backward sweep) and node voltage calculation (forward sweep). The first step of the algorithm is calculation of node voltages on the radial part of the network. The second step is calculation of the breakpoint currents. Then, the procedure continues with the first step, which is preceded by voltage correction. It is illustrated that using voltage correction approach, the iterative process of weakly meshed network voltage calculation is faster and more reliable.

  17. Turbulent flow through screens

    NASA Technical Reports Server (NTRS)

    Mehta, R. D.

    1984-01-01

    A detailed experimental investigation has been carried out on the effects of different types of screens on turbulent flow, in particular turbulent boundary layers. The effect of a screen on a turbulent boundary layer is to give it a 'new lease of life'. The boundary layer turbulence is reorganized and the thickness reduced, thus making it less susceptible to separation. The aerodynamic properties of plastic screens are found to differ significantly from those of the conventional metal screens, evidently because of differences in the weaving properties. The 'overshoot' in mean velocity profile near the boudnary layer edge is shown to be a result of the effect of screen inclination on pressure drop coefficient. A more accurate formulation for the deflection coefficient of a screen is also proposed.

  18. Olympus Mons Lava Flows

    NASA Technical Reports Server (NTRS)

    2002-01-01

    (Released 05 April 2002) Olympus Mons stands 26 km above the surrounding plains, which is three times taller than Mt. Everest, and is the tallest volcano in the solar system. Olympus Mons is also wider (585 km) than the state of Arizona. Although these are impressive dimensions an astronaut would find walking these slopes easy, as they are typically only 2 to 5 degrees. This image contains numerous lava flows, leveed lava channels, a discontinuous sinuous rille (thought to be a collapsed lava tube) and lava plains. Close examination of the sinuous rille reveals that portions of the roof of the lava tube have not completely collapsed. All of these features can be seen in basaltic (iron and magnesium rich black rock) volcanic regions on Earth like Hawaii and Iceland. Impact craters are scarce, indicating a relatively young age (several hundred million years old) for these surfaces.

  19. Uranyl Nitrate Flow Loop

    SciTech Connect

    Ladd-Lively, Jennifer L

    2008-10-01

    The objectives of the work discussed in this report were to: (1) develop a flow loop that would simulate the purified uranium-bearing aqueous stream exiting the solvent extraction process in a natural uranium conversion plant (NUCP); (2) develop a test plan that would simulate normal operation and disturbances that could be anticipated in an NUCP; (3) use the flow loop to test commercially available flowmeters for use as safeguards monitors; and (4) recommend a flowmeter for production-scale testing at an NUCP. There has been interest in safeguarding conversion plants because the intermediate products [uranium dioxide (UO{sub 2}), uranium tetrafluoride (UF{sub 4}), and uranium hexafluoride (UF{sub 6})] are all suitable uranium feedstocks for producing special nuclear materials. Furthermore, if safeguards are not applied virtually any nuclear weapons program can obtain these feedstocks without detection by the International Atomic Energy Agency (IAEA). Historically, IAEA had not implemented safeguards until the purified UF{sub 6} product was declared as feedstock for enrichment plants. H. A. Elayat et al. provide a basic definition of a safeguards system: 'The function of a safeguards system on a chemical conversion plant is in general terms to verify that no useful nuclear material is being diverted to use in a nuclear weapons program'. The IAEA now considers all highly purified uranium compounds as candidates for safeguarding. DOE is currently interested in 'developing instruments, tools, strategies, and methods that could be of use to the IAEA in the application of safeguards' for materials found in the front end of the nuclear fuel cycle-prior to the production of the uranium hexafluoride or oxides that have been the traditional starting point for IAEA safeguards. Several national laboratories, including Oak Ridge, Los Alamos, Lawrence Livermore, and Brookhaven, have been involved in developing tools or techniques for safeguarding conversion plants. This study

  20. Eroding Lava Flows

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site]

    Today's image illustrates how radically the wind can affect the surface of Mars. The lava flows in this region have been covered by fine materials, and eroded by the sand blasting action of the wind. In this region the winds are blowing to the west, eroding the lava surface to form small east/west ridges and bumps. Given enough time the winds will change the appearance of the surface to such a large extent that all flow features will be erased.

    Image information: VIS instrument. Latitude -11.7, Longitude 220 East (140 West). 17 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  1. Magnetized Astrophysical Flows

    NASA Astrophysics Data System (ADS)

    Russo, Matthew

    2016-08-01

    This thesis combines two studies of astrophysical flows in which magnetic fields play a dominant role. The first concerns outflows from compact objects in which plasma is accelerated to highly relativistic speeds by strong, ordered magnetic fields. We generalize the theory of relativistic, ideal magnetohydrodynamic (MHD) outflows by including an intense radiation source as is likely to occur in gamma-ray bursts (GRBs). This represents a hybrid of the traditional fireball and electromagnetic models of GRBs, which posit respectively that the acceleration is accomplished by thermal pressure or magnetic stresses. We find that acceleration is more efficient and occurs over a larger range of radii than in a pure Poynting jet. We also uncover a distinct observational signature in the emitted spectrum when the Poynting flux exceeds the radiation energy flux due to the Compton up-scattering of photons within the relativistic flow. We then turn to study the accretion of magnetized protoplanetary disks (PPDs) in which the assumptions of ideal MHD begin to break down due to the low level of ionization. We develop a novel model that prescribes the profiles of the magnetic field and mass flux in PPDs by tying them to the field of a magnetized, radial protostellar wind. We find that the inner disk is more strongly magnetized and thus supports a higher accretion rate by both large scale stresses and turbulence driven by the magnetorotational instability (MRI). This leads to an inside-out clearing of the inner disk that stalls at a low column density when particles are lofted from the midplane to higher altitudes where they suppress MRI turbulence. We calculate the long-term evolution of such a disk and show that the migration of planets is significantly slowed (or reversed), perhaps alleviating one of the central problems concerning the formation of planetary systems.

  2. Saturation of Zonal Flows

    NASA Astrophysics Data System (ADS)

    Kim, Eun-Jin

    2002-11-01

    Zonal flows (ZF) are generated by drift wave (DW) turbulence and then regulate it near marginality by shear suppression. Since collisions damp ZF while ZF suppress DW, the amplitude of DW turbulence (i.e. turbulent transport) is, in turn, proportional to collisionality. A key question is then what happens away from marginality, namely what is the saturation mechanism of ZF in that regime? This raises the interesting physical question of how ZF interact with mne 0, poloidally non-axisymmetric modes [1], both linearly and non linearly. We investigate this issue by exploring the nonlinear excitation of GKH modes by modulational instability in the background of finite amplitude of DW turbulence, as well as the linear inflection-type instability of ZF. In a simple model with cold ions, we show that ZF can grow faster than the linear GKH for γ/ω

    flow and temperature are generated by modulational instability. The phase between the two is calculated self-consistently and shown to be positive. Furthermore, the correction to nonlinear generation of GKH modes appears to be small. [1] We refer to these low mne 0 modes as Generalized Kelvin-Helmholtz (GKH) modes, since they will appear as mne 0 distortions of a shear layer.

  3. Magnetic heat pump flow director

    NASA Technical Reports Server (NTRS)

    Howard, Frank S. (Inventor)

    1995-01-01

    A fluid flow director is disclosed. The director comprises a handle body and combed-teeth extending from one side of the body. The body can be formed of a clear plastic such as acrylic. The director can be used with heat exchangers such as a magnetic heat pump and can minimize the undesired mixing of fluid flows. The types of heat exchangers can encompass both heat pumps and refrigerators. The director can adjust the fluid flow of liquid or gas along desired flow directions. A method of applying the flow director within a magnetic heat pump application is also disclosed where the comb-teeth portions of the director are inserted into the fluid flow paths of the heat pump.

  4. Lava crusts and flow dynamics

    NASA Technical Reports Server (NTRS)

    Kilburn, C. R. J.

    1993-01-01

    Lava flows can be considered as hot viscous cores within thinner, solidified crusts. Interaction between crust and core determines a flow's morphological and dynamical evolution. When the lava core dominates, flow advance approaches a steady state. When crusts are the limiting factor, advance is more irregular. These two conditions can be distinguished by a timescale ratio comparing rates of core deformation and crustal formation. Aa and budding pahoehoe lavas are used as examples of core- and crustal-dominated flows, respectively. A simple model describes the transition between pahoehoe and aa flow in terms of lava discharge rate, underlying slope, and either the thickness or velocity of the flow front. The model shows that aa morphologies are characterized by higher discharge rates and frontal velocities and yields good quantitative agreement with empirical relations distinguishing pahoehoe and aa emplacement on Hawaii.

  5. Flow, affect and visual creativity.

    PubMed

    Cseh, Genevieve M; Phillips, Louise H; Pearson, David G

    2015-01-01

    Flow (being in the zone) is purported to have positive consequences in terms of affect and performance; however, there is no empirical evidence about these links in visual creativity. Positive affect often--but inconsistently--facilitates creativity, and both may be linked to experiencing flow. This study aimed to determine relationships between these variables within visual creativity. Participants performed the creative mental synthesis task to simulate the creative process. Affect change (pre- vs. post-task) and flow were measured via questionnaires. The creativity of synthesis drawings was rated objectively and subjectively by judges. Findings empirically demonstrate that flow is related to affect improvement during visual creativity. Affect change was linked to productivity and self-rated creativity, but no other objective or subjective performance measures. Flow was unrelated to all external performance measures but was highly correlated with self-rated creativity; flow may therefore motivate perseverance towards eventual excellence rather than provide direct cognitive enhancement.

  6. Flow analysis system and method

    NASA Technical Reports Server (NTRS)

    Hill, Wayne S. (Inventor); Barck, Bruce N. (Inventor)

    1998-01-01

    A non-invasive flow analysis system and method wherein a sensor, such as an acoustic sensor, is coupled to a conduit for transmitting a signal which varies depending on the characteristics of the flow in the conduit. The signal is amplified and there is a filter, responsive to the sensor signal, and tuned to pass a narrow band of frequencies proximate the resonant frequency of the sensor. A demodulator generates an amplitude envelope of the filtered signal and a number of flow indicator quantities are calculated based on variations in amplitude of the amplitude envelope. A neural network, or its equivalent, is then used to determine the flow rate of the flow in the conduit based on the flow indicator quantities.

  7. Coherent structures in reacting flows

    NASA Astrophysics Data System (ADS)

    Mahoney, John; Mitchell, Kevin

    2013-11-01

    Our goal is to characterize the nature of reacting flows by identifying important ``coherent'' structures. We follow the recent work by Haller, Beron-Vera, and Farazmand which formalized the the notion of lagrangian coherent structures (LCSs) in fluid flows. In this theory, LCSs were derived from the Cauchy-Green strain tensor. We adapt this perspective to analogously define coherent structures in reacting flows. By this we mean a fluid flow with a reaction front propagating through it such that the propagation does not affect the underlying flow. A reaction front might be chemical (Belousov-Zhabotinsky, flame front, etc.) or some other type of front (electromagnetic, acoustic, etc.). While the recently developed theory of burning invariant manifolds (BIMs) describes barriers to front propagation in time-periodic flows, this current work provides an important complement by extending to the aperiodic setting. The present work was supported by the US National Science Foundation under grants PHY- 0748828 and CMMI-1201236.

  8. Joule heating in electrokinetic flow.

    PubMed

    Xuan, Xiangchun

    2008-01-01

    Electrokinetic flow is an efficient means to manipulate liquids and samples in lab-on-a-chip devices. It has a number of significant advantages over conventional pressure-driven flow. However, there exists inevitable Joule heating in electrokinetic flow, which is known to cause temperature variations in liquids and draw disturbances to electric, flow and concentration fields via temperature-dependent material properties. Therefore, both the throughput and the resolution of analytic studies performed in microfluidic devices are affected. This article reviews the recent progress on the topic of Joule heating and its effect in electrokinetic flow, particularly the theoretical and experimental accomplishments from the aspects of fluid mechanics and heat/mass transfer. The primary focus is placed on the temperature-induced flow variations and the accompanying phenomena at the whole channel or chip level.

  9. Active combustion flow modulation valve

    DOEpatents

    Hensel, John Peter; Black, Nathaniel; Thorton, Jimmy Dean; Vipperman, Jeffrey Stuart; Lambeth, David N; Clark, William W

    2013-09-24

    A flow modulation valve has a slidably translating hollow armature with at least one energizable coil wound around and fixably attached to the hollow armature. The energizable coil or coils are influenced by at least one permanent magnet surrounding the hollow armature and supported by an outer casing. Lorentz forces on the energizable coils which are translated to the hollow armature, increase or decrease the flow area to provide flow throttling action. The extent of hollow armature translation depends on the value of current supplied and the direction of translation depends on the direction of current flow. The compact nature of the flow modulation valve combined with the high forces afforded by the actuator design provide a flow modulation valve which is highly responsive to high-rate input control signals.

  10. Endovascular blood flow measurement system

    NASA Astrophysics Data System (ADS)

    Khe, A. K.; Cherevko, A. A.; Chupakhin, A. P.; Krivoshapkin, A. L.; Orlov, K. Yu

    2016-06-01

    In this paper an endovascular measurement system used for intraoperative cerebral blood flow monitoring is described. The system is based on a Volcano ComboMap Pressure and Flow System extended with analogue-to-digital converter and PC laptop. A series of measurements performed in patients with cerebrovascular pathologies allows us to introduce “velocity-pressure” and “flow rate-energy flow rate” diagrams as important characteristics of the blood flow. The measurement system presented here can be used as an additional instrument in neurosurgery for assessment and monitoring of the operation procedure. Clinical data obtained with the system are used for construction of mathematical models and patient-specific simulations. The monitoring of the blood flow parameters during endovascular interventions was approved by the Ethics Committee at the Meshalkin Novosibirsk Research Institute of Circulation Pathology and included in certain surgical protocols for pre-, intra- and postoperative examinations.

  11. Direct Absorption Receiver flow experiments

    NASA Astrophysics Data System (ADS)

    Chavez, J. M.; Tyner, C. E.; Couch, W. A.

    1987-09-01

    In a solar central receiver system Direct Absorption Receiver (DAR), the heat absorbing fluid (a blackened molten nitrate salt) flows in a thin film down a vertical panel (rather than through tubes as in conventional receiver designs) and absorbs the concentrated solar flux directly. To better understand flow phenomena in this type of receiver, we are conducting flow tests using water (because its flow properties are similar to molten salt) and a 3 MWt solar-heated DAR panel research experiment using salt. In this paper we discuss the results of the water flow testing, including manifold development, film stability, wave phenomena, and wind and natural convection effects on flow. In addition, we describe the design of the panel research experiment and planned testing.

  12. Supersonic laminar flow control research

    NASA Technical Reports Server (NTRS)

    Lo, Ching F.

    1994-01-01

    The objective of the research is to understand supersonic laminar flow stability, transition, and active control. Some prediction techniques will be developed or modified to analyze laminar flow stability. The effects of supersonic laminar flow with distributed heating and cooling on active control will be studied. The primary tasks of the research applying to the NASA/Ames Proof of Concept (POC) Supersonic Wind Tunnel and Laminar Flow Supersonic Wind Tunnel (LFSWT) nozzle design with laminar flow control are as follows: (1) predictions of supersonic laminar boundary layer stability and transition, (2) effects of wall heating and cooling for supersonic laminar flow control, and (3) performance evaluation of POC and LFSWT nozzles design with wall heating and cooling effects applying at different locations and various length.

  13. Numerical Simulation of Turbulent Fluid Flows

    NASA Technical Reports Server (NTRS)

    Leonard, A.

    1983-01-01

    Numerical simulation of turbulent flows is discussed. Computational requirements for the direct simulaton of turbulence, simulation of arbitrary homogeneous flows, an expansion technique for wall bounded flows with application to pipe flow, and possibilities of flow representations or modeling techniques that allow the simulation of high Reynolds number flows with a relatively small number of dependent variables are included.

  14. Surface-Streamline Flow Visualization

    NASA Technical Reports Server (NTRS)

    Langston, L.; Boyle, M.

    1985-01-01

    Matrix of ink dots covers matte surface of polyester drafting film. Film placed against wind-tunnel wall. Layer of methyl salicylate (oil of wintergreen) sprayed over dotted area. Ink dot streaklines show several characteristics of flow, including primary saddle point of separations, primary horseshoe vortex and smaller vortex at cylinder/ endwall junction. Surface streamline flow visualization technique suitable for use in low-speed windtunnels or other low-speed gas flows.

  15. DEBRIS FLOWS AND HYPERCONCENTRATED STREAMFLOWS.

    USGS Publications Warehouse

    Wieczorek, Gerald F.

    1986-01-01

    Examination of recent debris-flow and hyperconcentrated-streamflow events in the western United States reveals (1) the topographic, geologic, hydrologic, and vegetative conditions that affect initiation of debris flows and (2) the wide ranging climatic conditions that can trigger debris flows. Recognition of these physiographic and climatic conditions has aided development of preliminary methods for hazard evaluation. Recent developments in the application of electronic data gathering, transmitting, and processing systems shows potential for real-time hazard warning.

  16. Geophysical fluid flow cell experiment

    NASA Technical Reports Server (NTRS)

    Hart, J. E.

    1982-01-01

    The primary purpose of the geophysical flow experiments is to simulate large-scale baroclinic (density-stratified) flows which occur naturally in the atmospheres of rotating planets and stars and to gain insights and obtain answers to crucial questions concerning the large-scale nonlinear mechanics of the global geophysical flows. Those external conditions related to fluid viscosity, rotation, gravity are identified, which allow qualitatively different modes of instability or waves in the model.

  17. Orbital shadowing for 3-flows

    NASA Astrophysics Data System (ADS)

    Gan, Shaobo; Li, Ming

    2017-05-01

    We call that a flow has the orbital shadowing property if for any ε > 0 there is d > 0 such that, for any d-pseudo orbit g (t) there exists an orbit Orb (x) satisfying distH (g (t) ‾ , Orb (x) ‾) < ε. In this paper, we show that the C1-interior of the set of 3-dimensional flows having the orbital shadowing property is contained in the set of Ω-stable 3-flows.

  18. Precipitated silica as flow regulator.

    PubMed

    Müller, Anne-Kathrin; Ruppel, Joanna; Drexel, Claus-Peter; Zimmermann, Ingfried

    2008-08-07

    Flow regulators are added to solid pharmaceutical formulations to improve the flow properties of the powder mixtures. The primary particles of the flow regulators exist in the form of huge agglomerates which are broken down into smaller aggregates during the blending process. These smaller aggregates adsorb at the surface of the solid's grains and thus diminish attractive Van-der-Waals-forces by increasing the roughness of the host's surface. In most cases amorphous silica is used as flow additive but material properties like particle size or bond strength influence the desagglomeration tendency of the agglomerates and thus the flow regulating potency of each silica. For some silica types we will show that the differences in their flow regulating potency are due to the rate and extent by which they are able to cover the surface of the host particles. Binary powder mixtures consisting of a pharmaceutical excipient and an added flow regulator were blended in a Turbula mixer for a defined period of time. As pharmaceutical excipient corn starch was used. The flow regulators were represented by a selection of amorphous silicon dioxide types like a commercial fumed silica and various types of SIPERNAT precipitated silica provided by Evonik-Degussa GmbH, Hanau, Germany. Flowability parameters of the mixtures were characterized by means of a tensile strength tester. The reduction of tensile strength with the blending time can be correlated with an increase in fragmentation of the flow regulator.

  19. Module bay with directed flow

    DOEpatents

    Torczynski, John R.

    2001-02-27

    A module bay requires less cleanroom airflow. A shaped gas inlet passage can allow cleanroom air into the module bay with flow velocity preferentially directed toward contaminant rich portions of a processing module in the module bay. Preferential gas flow direction can more efficiently purge contaminants from appropriate portions of the module bay, allowing a reduced cleanroom air flow rate for contaminant removal. A shelf extending from an air inlet slit in one wall of a module bay can direct air flowing therethrough toward contaminant-rich portions of the module bay, such as a junction between a lid and base of a processing module.

  20. Flow through very porous screens

    NASA Technical Reports Server (NTRS)

    Durbin, P. A.; Muramoto, K. K.

    1985-01-01

    Flow through and around screens with small resistance coefficient were analyzed. Both steady and oscillatory flows are considered, however, the case of a screen normal to the flow is treated. At second order in the asymptotic expansion the steady flow normal to the screen is nonuniform along the screen, due to components induced by the wake and by tangential drag. The third order pressure drop is nonuniform and the wake contains distributed vorticity, in addition to the vortex sheet along its boundary. The unsteady drag coefficient is found as a function of frequency.

  1. Numerical simulation of transitional flow

    NASA Technical Reports Server (NTRS)

    Biringen, Sedat

    1986-01-01

    The applicability of active control of transition by periodic suction-blowing is investigated via direct simulations of the Navier-Stokes equations. The time-evolution of finite-amplitude disturbances in plane channel flow is compared in detail with and without control. The analysis indicates that, for relatively small three-dimensional amplitudes, a two-dimensional control effectively reduces disturbance growth rates even for linearly unstable Reynolds numbers. After the flow goes through secondary instability, three-dimensional control seems necessary to stabilize the flow. An investigation of the temperature field suggests that passive temperature contamination is operative to reflect the flow dynamics during transition.

  2. Flow in Atherosclerotic Blood Vessels

    NASA Astrophysics Data System (ADS)

    Berger, Stanley A.; Stroud, Jenn S.

    2000-11-01

    Atherosclerotic lesions occur in arteries where there are major changes in flow structure, e.g. bifurcations and junctions. The reduction of vessel lumen alters the flow, including the mechanical forces on the walls. We have examined the flow in carotid artery bifurcations with realistic plaque contours. The unsteady, incompressible, Navier-Stokes equations are solved in finite-volume form. Steady and pulsatile flows have been analyzed for laminar and turbulent flows, using for the latter a low-Reynolds number k- ɛ model and a k-ω model. Non-Newtonian viscosity is also considered using a power-law model. In general the very irregular contours of the vessels lead to recirculating regions, strong spatial variations of wall shear stresses, and in some cases, vortex shedding. Even steady inlet flow exhibits fluctuating, unsteady behavior. Neither turbulence models captures all the physics of the flow. The flow, in fact, appears to be transitional and not fully turbulent. For unsteady flow, there are also strong temporal variations of normal and shear stresses, which together with the strong spatial variations, has important implications for the onset and progression of atherosclerotic disease.

  3. Optic flow and autonomous navigation.

    PubMed

    Campani, M; Giachetti, A; Torre, V

    1995-01-01

    Many animals, especially insects, compute and use optic flow to control their motion direction and to avoid obstacles. Recent advances in computer vision have shown that an adequate optic flow can be computed from image sequences. Therefore studying whether artificial systems, such as robots, can use optic flow for similar purposes is of particular interest. Experiments are reviewed that suggest the possible use of optic flow for the navigation of a robot moving in indoor and outdoor environments. The optic flow is used to detect and localise obstacles in indoor scenes, such as corridors, offices, and laboratories. These routines are based on the computation of a reduced optic flow. The robot is usually able to avoid large obstacles such as a chair or a person. The avoidance performances of the proposed algorithm critically depend on the optomotor reaction of the robot. The optic flow can be used to understand the ego-motion in outdoor scenes, that is, to obtain information on the absolute velocity of the moving vehicle and to detect the presence of other moving objects. A critical step is the correction of the optic flow for shocks and vibrations present during image acquisition. The results obtained suggest that optic flow can be successfully used by biological and artificial systems to control their navigation. Moreover, both systems require fast and accurate optomotor reactions and need to compensate for the instability of the viewed world.

  4. Turbulence in slurry pipe flow

    SciTech Connect

    Gore, R.A. ); Crowe, C.T. . Dept. of Mechanical and Materials Engineering)

    1990-01-01

    The present state of knowledge of liquid-solid flows (slurries) is far behind than that for single phase flows. Very few geometries have been examined with a slurry and only with a limited variation of system parameters i.e. fluid viscosity, particle diameter, etc. This paper presents the first part of a study which examines the effects of the addition of a solid to the flow through a confined coaxial jet. Presented here will be the initial conditions for the jet which correspond to fully developed pipe flow. 6 refs., 9 figs.

  5. Efficiency of osmotic pipe flows

    NASA Astrophysics Data System (ADS)

    Haaning, Louise Sejling; Jensen, Kaare Hartvig; Hélix-Nielsen, Claus; Berg-Sørensen, Kirstine; Bohr, Tomas

    2013-05-01

    We present experiments and theory for flows of sugar or salt solutions in cylindrical tubes with semipermeable walls (hollow fiber membranes) immersed in water, quantifying the strength of the osmotic driving force in relation to the dimensionless parameters that specify the system. The pumping efficiency of these flows is limited by the presence of “unstirred” concentration boundary layers near the tube walls, and our primary aim is to understand and quantify these layers and their effect on the flow. We measure the outlet flow rate Qout while varying the inlet flow rate Q*, concentration c*, and tube length L, and map out the dependence of the flow rate gain γ=Qout/Q*-1 on these parameters. A theoretical analysis based on (1) the known velocity field for slow flow in cylindrical porous tubes and (2) a parabolic concentration profile allows us to compute analytically how the flow gain depends on the relative magnitude of radial diffusion and advection as well as the ratio of the osmotic velocity to pumping velocity, in very good agreement with experiments and with no adjustable parameters. Our analysis provides criteria that are useful for optimizing osmotic flow processes in, e.g., water purification devices.

  6. Surface obstacles in pulsatile flow

    NASA Astrophysics Data System (ADS)

    Carr, Ian A.; Plesniak, Michael W.

    2016-11-01

    Flows past obstacles mounted on flat surfaces have been widely studied due to their ubiquity in nature and engineering. For nearly all of these studies, the freestream flow over the obstacle was steady, i.e. constant velocity unidirectional flow. Unsteady, pulsatile flows occur frequently in biology, geophysics, biomedical engineering, etc. Our study is aimed at extending the comprehensive knowledge base that exists for steady flows to considerably more complex pulsatile flows. Beyond the important practical applications, characterizing the vortex and wake dynamics of flows around surface obstacles embedded in pulsatile flows can provide insights into the underlying physics in all wake and junction flows. In this study, we experimentally investigated the wake of four canonical surface obstacles: hemisphere, cube, and circular cylinders with aspect ratio of 1:1 and 2:1. Phase-averaged PIV and hot-wire anemometry are used to characterize the dynamics of coherent structures in the wake and at the windward junction of the obstacles. Complex physics occur during the deceleration phase of the pulsatile inflow. We propose a framework for understanding these physics based on self-induced vortex propagation, similar to the phenomena exhibited by vortex rings. This material is based in part upon work supported by the National Science Foundation under Grant Number CBET-1236351, and GW Centeor Biomimetics and Bioinspired Engineering (COBRE).

  7. Supersonic laminar flow control research

    NASA Technical Reports Server (NTRS)

    Lo, C. F.

    1994-01-01

    The objective of the research is to understand supersonic laminar flow stability, transition and active control. Some prediction techniques will be developed or modified to analyze laminar stability. The effects of supersonic laminar flow with distributed heating and cooling on active control will be studied. The primary tasks of the research applying to the NASA/Ames POC and LFSWT's nozzle design with laminar flow control are as follows: (1) supersonic laminar boundary layer stability and transition prediction; (2) effects of heating and cooling for supersonic laminar flow control; and (3) POC and LFSWT nozzle design with heating and cooling effects combining wall contour and length changes.

  8. Computation of viscous incompressible flows

    NASA Technical Reports Server (NTRS)

    Kwak, Dochan

    1989-01-01

    Incompressible Navier-Stokes solution methods and their applications to three-dimensional flows are discussed. A brief review of existing methods is given followed by a detailed description of recent progress on development of three-dimensional generalized flow solvers. Emphasis is placed on primitive variable formulations which are most promising and flexible for general three-dimensional computations of viscous incompressible flows. Both steady- and unsteady-solution algorithms and their salient features are discussed. Finally, examples of real world applications of these flow solvers are given.

  9. Flight experiences with laminar flow

    NASA Technical Reports Server (NTRS)

    Holmes, Bruce J.

    1986-01-01

    A review of natural laminar flow (NLF) flight experiences over the period from the 1930's to the present has been given to provide information on the achievability and maintainability of NLF in typical airplane operating environments. Significant effects of loss of laminar flow on airplane performance have been observed for several airplanes, indicating the importance of providing information on these changes to laminar flow airplane operators. Significant changes in airplane stability and control and maximum lift were observed in flight experiments with the loss of laminar flow. However, these effects can be avoided by proper selection of airfoils. Conservative laminar flow airfoil designs should be employed which do not experience significant loss of lift (caused by flow separation) upon the loss of laminar flow. Mechanisms have been observed for the effects of insect accumulation, flight through clouds and precipitation, and propeller slipstreams on laminar flow behavior. Fixed transition testing, in addition to free transition testing, is recommended as a new standard procedure for airplanes with surfaces designed to support laminar flow.

  10. Go with the (Bright) Flow

    NASA Image and Video Library

    2017-09-18

    NASA's Mars Reconnaissance Orbiter observes many slopes in the middle latitudes of Mars showing icy flows or glaciers. The region shown here, in the south-facing slope of a crater, is unusual because the flows have bright highlights. The color and brightness variations are likely due to surface coatings of bright dust and dark sand. There is no evidence that these flows are currently active, but they may have been active only millions of years ago. These flows may well contain ice today in their interiors, as confirmed in places by the subsurface radar experiment on MRO. https://photojournal.jpl.nasa.gov/catalog/PIA21953

  11. Hydrodynamics of viscous inhalant flows

    NASA Astrophysics Data System (ADS)

    True, Aaron C.; Crimaldi, John P.

    2017-05-01

    Inhalant flows draw fluid into an orifice from a reservoir and are ubiquitous in engineering and biology. Surprisingly, there is a lack of quantitative information on viscous inhalant flows. We consider here laminar flows (Reynolds number Re≤100 ) developing after impulsive inhalation begins. We implement finite element simulations of flows with varying Re and extraction height h (orifice height above a bottom bed). Numerical results are experimentally validated using particle image velocimetry measurements in a physical model for a representative flow case in the middle of the Re-h parameter space. We use two metrics to characterize the flow in space and time: regions of influence (ROIs), which describe the spatial extent of the flow field, and inhalation volumes, which describe the initial distribution of inhaled fluid. The transient response for all Re features an inviscid sinklike component at early times followed by a viscous diffusive component. At lower Re, diffusion entrains an increasing volume of fluid over time, enlarging the ROI indefinitely. In some geometries, these flows spatially bifurcate, with some fluid being inhaled through the orifice and some bypassing into recirculation. At higher Re, inward advection dominates outward viscous diffusion and the flow remains trapped in a sinklike state. Both ROIs and inhalation volumes are strongly dependent on Re and extraction height, suggesting that organisms or engineers could tune these parameters to achieve specific inhalation criteria.

  12. The GO-FLOW methodology

    SciTech Connect

    Matsuoka, T.; Kobayashi, M.; Takemura, K.

    1989-03-01

    A reliability analysis using the GO-FLOW methodology is given for the emergency core cooling system (ECCS) of a marine reactor experiencing either a collision or a grounding accident. The analysis is an example of a phased mission problem, and the system is a relatively large system with 90 components. An overview of the GO-FLOW methodology, a description of the ECCS, and the analysis procedure are given. Time-dependent mission unreliabilities under three accident conditions are obtained by one GO-FLOW chart with one computer run. The GO-FLOW methodology has proved to be a useful tool for probabilistic safety assessments of actual systems.

  13. Modeling Size Polydisperse Granular Flows

    NASA Astrophysics Data System (ADS)

    Lueptow, Richard M.; Schlick, Conor P.; Isner, Austin B.; Umbanhowar, Paul B.; Ottino, Julio M.

    2014-11-01

    Modeling size segregation of granular materials has important applications in many industrial processes and geophysical phenomena. We have developed a continuum model for granular multi- and polydisperse size segregation based on flow kinematics, which we obtain from discrete element method (DEM) simulations. The segregation depends on dimensionless control parameters that are functions of flow rate, particle sizes, collisional diffusion coefficient, shear rate, and flowing layer depth. To test the theoretical approach, we model segregation in tri-disperse quasi-2D heap flow and log-normally distributed polydisperse quasi-2D chute flow. In both cases, the segregated particle size distributions match results from full-scale DEM simulations and experiments. While the theory was applied to size segregation in steady quasi-2D flows here, the approach can be readily generalized to include additional drivers of segregation such as density and shape as well as other geometries where the flow field can be characterized including rotating tumbler flow and three-dimensional bounded heap flow. Funded by The Dow Chemical Company and NSF Grant CMMI-1000469.

  14. UZ Flow Models and Submodels

    SciTech Connect

    P. Dixon

    2004-02-11

    The purpose of this Model Report is to document the unsaturated zone (UZ) fluid flow and tracer transport models and submodels as well as the flow fields generated utilizing the UZ Flow and Transport Model of Yucca Mountain (UZ Model), Nevada. This work was planned in ''Technical Work Plan (TWP) for: Performance Assessment Unsaturated Zone'' (BSC 2002 [160819], Section 1.10, Work Package AUZM06). The UZ Model has revised, updated, and enhanced the previous UZ Flow Model REV 00 ICN 01 (BSC 2001 [158726]) by incorporation of the conceptual repository design with new grids, recalibration of property sets, and more comprehensive validation effort. The flow fields describe fracture-fracture, matrix-matrix, and fracture-matrix liquid flow rates and their spatial distributions as well as moisture conditions in the UZ system. These 3-D UZ flow fields are used directly by Performance Assessment (PA). The model and submodels evaluate important hydrogeologic processes in the UZ as well as geochemistry and geothermal conditions. These provide the necessary framework to test conceptual hypotheses of flow and transport at different scales and predict flow and transport behavior under a variety of climatic conditions. In addition, this Model Report supports several PA activities, including abstractions, particle-tracking transport simulations, and the UZ Radionuclide Transport Model.

  15. Multigrid for hypersonic inviscid flows

    NASA Technical Reports Server (NTRS)

    Decker, Naomi H.; Turkel, Eli

    1990-01-01

    The use of multigrid methods to solve the Euler equations for hypersonic flow is discussed. The steady state equations are considered with a Runge-Kutta smoother based on the time accurate equations together with local time stepping and residual smoothing. The effect of the Runge-Kutta coefficients on the convergence rate was examined considering both damping characteristics and convection properties. The importance of boundary conditions on the convergence rate for hypersonic flow is discussed. Also of importance are the switch between the second and fourth difference viscosity. Solutions are given for flow around the bump in a channel and flow around a biconic section.

  16. Ferrofluid flow for TOUGH2

    SciTech Connect

    Oldenburg, Curtis; Moridis, George

    1998-03-24

    We have developed EOS7M, a ferrofluid flow and transport module for TOUGH2. EOS7M calculates the magnetic forces on ferrofluid caused by an external magnetic field and allows simulation of flow and advective transport of ferrofluid-water mixtures through porous media. Such flow problems are strongly coupled and well suited to the TOUGH2 framework. Preliminary applications of EOS7M to some simple pressure and flow problems for which experiments were carried out in the lab show good qualitative agreement with the laboratory results.

  17. Flow visualization using moving textures

    SciTech Connect

    Max, N.; Becker, B.

    1995-04-01

    An intuitive way to visualize a flow is to watch particles or textures move in the flow. In this paper, the authors show how texture mapping hardware can produce near-real-time texture motion, using a polygon grid, and one fixed texture. However, the authors make no attempt to indicate the flow direction in a still frame. As discussed here, any anisotropic stretching comes from the velocity gradient, not the velocity itself. The basic idea is to advect the texture by the flow field. In a cited paper, they gave an indication of the wind velocity by advecting the 3D texture coordinates on the polygon vertices of a cloudiness contour surface in a climate simulation. This was slow, because the 3D texture was rendered in software, and because advecting the texture was difficult for time-varying flows. In this paper, they replace the 3D textures by 2D texture maps compatible with hardware rendering, and give techniques for handling time-varying flows more efficiently. The next section gives their technique for the case of 2D steady flows, and the following one discusses the problems of texture distortion. Then they discuss the problems with extending method to time-varying flows, and two solutions. Next they develop compositing methods for visualizing 3D flows. The final section gives their results and conclusions.

  18. Computational Unsteady Flow Dynamics: Oscillating Flow About a Circular Cylinder

    DTIC Science & Technology

    1991-12-01

    that the calculations can be carried out only for short times (less than two cycles of flow oscillation) with a non-super computer. Murashige , Hinatsu...Flow Round a Circu- lar Cylinder," Computers &Fluids, Vol. 12, No. 4, pp. 255-280. 6. Murashige , S., Hinatsu, M., and Kinoshita, T, 1989, "Direct

  19. Reconsidering Television Program Flows, or Whose Flow Is It Anyway?

    ERIC Educational Resources Information Center

    White, Mimi

    1995-01-01

    Argues that media flow research needs to be reconceptualized differently from notions of one-way flows that serve coherent national interests, and whose asymmetries can be measured statistically and unambiguously. Argues that global circulation is now complex and contradictory, and that new culturally-based models and methods are needed for…

  20. Flow simulation and analysis of high-power flow batteries

    NASA Astrophysics Data System (ADS)

    Knudsen, E.; Albertus, P.; Cho, K. T.; Weber, A. Z.; Kojic, A.

    2015-12-01

    The cost of a flow battery system can be reduced by increasing its power density and thereby reducing its stack area. If per-pass utilizations are held constant, higher battery power densities can only be achieved using higher flow rates. Here, a 3D computational fluid dynamics model of a flow battery flow field and electrode is used to analyze the implications of increasing flow rates to high power density operating conditions. Interdigitated and serpentine designs, and cell sizes ranging from 10 cm2 to 400 cm2, are simulated. The results quantify the dependence of pressure loss on cell size and design, demonstrating that the details of the passages that distribute flow between individual channels and the inlet and outlet have a major impact on pressure losses in larger cells. Additionally, in-cell flow behavior is analyzed as a function of cell size and design. Flow structures are interrogated to show how and where electrode parameters influence pressure drops, and how regions where transport is slow are correlated with the presence of experimentally observed cell degradation.