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Sample records for estimating donor flows

  1. A neural flow estimator

    DEFF Research Database (Denmark)

    Jørgensen, Ivan Harald Holger; Bogason, Gudmundur; Bruun, Erik

    1995-01-01

    This paper proposes a new way to estimate the flow in a micromechanical flow channel. A neural network is used to estimate the delay of random temperature fluctuations induced in a fluid. The design and implementation of a hardware efficient neural flow estimator is described. The system...... is implemented using switched-current technique and is capable of estimating flow in the μl/s range. The neural estimator is built around a multiplierless neural network, containing 96 synaptic weights which are updated using the LMS1-algorithm. An experimental chip has been designed that operates at 5 V...

  2. Robust Optical Flow Estimation

    Directory of Open Access Journals (Sweden)

    Javier Sánchez Pérez

    2013-10-01

    Full Text Available n this work, we describe an implementation of the variational method proposed by Brox etal. in 2004, which yields accurate optical flows with low running times. It has several benefitswith respect to the method of Horn and Schunck: it is more robust to the presence of outliers,produces piecewise-smooth flow fields and can cope with constant brightness changes. Thismethod relies on the brightness and gradient constancy assumptions, using the information ofthe image intensities and the image gradients to find correspondences. It also generalizes theuse of continuous L1 functionals, which help mitigate the effect of outliers and create a TotalVariation (TV regularization. Additionally, it introduces a simple temporal regularizationscheme that enforces a continuous temporal coherence of the flow fields.

  3. Intelligent Flow Friction Estimation.

    Science.gov (United States)

    Brkić, Dejan; Ćojbašić, Žarko

    2016-01-01

    Nowadays, the Colebrook equation is used as a mostly accepted relation for the calculation of fluid flow friction factor. However, the Colebrook equation is implicit with respect to the friction factor (λ). In the present study, a noniterative approach using Artificial Neural Network (ANN) was developed to calculate the friction factor. To configure the ANN model, the input parameters of the Reynolds Number (Re) and the relative roughness of pipe (ε/D) were transformed to logarithmic scales. The 90,000 sets of data were fed to the ANN model involving three layers: input, hidden, and output layers with, 2, 50, and 1 neurons, respectively. This configuration was capable of predicting the values of friction factor in the Colebrook equation for any given values of the Reynolds number (Re) and the relative roughness (ε/D) ranging between 5000 and 10(8) and between 10(-7) and 0.1, respectively. The proposed ANN demonstrates the relative error up to 0.07% which had the high accuracy compared with the vast majority of the precise explicit approximations of the Colebrook equation.

  4. Intelligent Flow Friction Estimation

    Directory of Open Access Journals (Sweden)

    Dejan Brkić

    2016-01-01

    Full Text Available Nowadays, the Colebrook equation is used as a mostly accepted relation for the calculation of fluid flow friction factor. However, the Colebrook equation is implicit with respect to the friction factor (λ. In the present study, a noniterative approach using Artificial Neural Network (ANN was developed to calculate the friction factor. To configure the ANN model, the input parameters of the Reynolds Number (Re and the relative roughness of pipe (ε/D were transformed to logarithmic scales. The 90,000 sets of data were fed to the ANN model involving three layers: input, hidden, and output layers with, 2, 50, and 1 neurons, respectively. This configuration was capable of predicting the values of friction factor in the Colebrook equation for any given values of the Reynolds number (Re and the relative roughness (ε/D ranging between 5000 and 108 and between 10−7 and 0.1, respectively. The proposed ANN demonstrates the relative error up to 0.07% which had the high accuracy compared with the vast majority of the precise explicit approximations of the Colebrook equation.

  5. Estimation of standard liver volume in Chinese adult living donors.

    Science.gov (United States)

    Fu-Gui, L; Lu-Nan, Y; Bo, L; Yong, Z; Tian-Fu, W; Ming-Qing, X; Wen-Tao, W; Zhe-Yu, C

    2009-12-01

    To determine a formula predicting the standard liver volume based on body surface area (BSA) or body weight in Chinese adults. A total of 115 consecutive right-lobe living donors not including the middle hepatic vein underwent right hemi-hepatectomy. No organs were used from prisoners, and no subjects were prisoners. Donor anthropometric data including age, gender, body weight, and body height were recorded prospectively. The weights and volumes of the right lobe liver grafts were measured at the back table. Liver weights and volumes were calculated from the right lobe graft weight and volume obtained at the back table, divided by the proportion of the right lobe on computed tomography. By simple linear regression analysis and stepwise multiple linear regression analysis, we correlated calculated liver volume and body height, body weight, or body surface area. The subjects had a mean age of 35.97 +/- 9.6 years, and a female-to-male ratio of 60:55. The mean volume of the right lobe was 727.47 +/- 136.17 mL, occupying 55.59% +/- 6.70% of the whole liver by computed tomography. The volume of the right lobe was 581.73 +/- 96.137 mL, and the estimated liver volume was 1053.08 +/- 167.56 mL. Females of the same body weight showed a slightly lower liver weight. By simple linear regression analysis and stepwise multiple linear regression analysis, a formula was derived based on body weight. All formulae except the Hong Kong formula overestimated liver volume compared to this formula. The formula of standard liver volume, SLV (mL) = 11.508 x body weight (kg) + 334.024, may be applied to estimate liver volumes in Chinese adults.

  6. 2007 Estimated International Energy Flows

    Energy Technology Data Exchange (ETDEWEB)

    Smith, C A; Belles, R D; Simon, A J

    2011-03-10

    An energy flow chart or 'atlas' for 136 countries has been constructed from data maintained by the International Energy Agency (IEA) and estimates of energy use patterns for the year 2007. Approximately 490 exajoules (460 quadrillion BTU) of primary energy are used in aggregate by these countries each year. While the basic structure of the energy system is consistent from country to country, patterns of resource use and consumption vary. Energy can be visualized as it flows from resources (i.e. coal, petroleum, natural gas) through transformations such as electricity generation to end uses (i.e. residential, commercial, industrial, transportation). These flow patterns are visualized in this atlas of 136 country-level energy flow charts.

  7. Estimating the Number of Organ Donors in Australian Hospitals—Implications for Monitoring Organ Donation Practices

    Science.gov (United States)

    Pilcher, David; Gladkis, Laura; Arcia, Byron; Bailey, Michael; Cook, David; Cass, Yael; Opdam, Helen

    2015-01-01

    Background The Australian DonateLife Audit captures information on all deaths which occur in emergency departments, intensive care units and in those recently discharged from intensive care unit. This information provides the opportunity to estimate the number of donors expected, given present consent rates and contemporary donation practices. This may then allow benchmarking of performance between hospitals and jurisdictions. Our aim was to develop a method to estimate the number of donors using data from the DonateLife Audit on the basis of baseline patient characteristics alone. Methods All intubated patient deaths at contributing hospitals were analyzed. Univariate comparisons of donors to nondonors were performed. A logistic regression model was developed to estimate expected donor numbers from data collected between July 2012 and December 2013. This was validated using data from January to April 2014. Results Between July 2012 and April 2014, 6861 intubated patient deaths at 68 hospitals were listed on the DonateLife Audit of whom 553 (8.1%) were organ donors. Factors independently associated with organ donation included age, brain death, neurological diagnoses, chest x-ray findings, PaO2/FiO2, creatinine, alanine transaminase, cancer, cardiac arrest, chronic heart disease, and peripheral vascular disease. A highly discriminatory (area under the receiver operatory characteristic, 0.940 [95% confidence interval, 0.924-0.957]) and well-calibrated prediction model was developed which accurately estimated donor numbers. Three hospitals appeared to have higher numbers of actual donors than expected. Conclusions It is possible to estimate the expected number of organ donors. This may assist benchmarking of donation outcomes and interpretation of changes in donation rates over time. PMID:25919766

  8. Dynamic renal scintigraphic estimation of deceased donor kidneys in a rat model

    Directory of Open Access Journals (Sweden)

    Huseyin Aydin Mitil

    2017-01-01

    Full Text Available At present a large number of the renal transplantations are being performed from the deceased donors. The success of these transplantations depends on the viability of the deceased donor kidneys. The aim of this study was to investigate the reliability of scintigraphic estimation of function of deceased donor kidneys by comparing the histopathologic and scintigraphic findings. Ten rats were included in the study (2–3 months old, 250–300 g, all male. Control scintigraphy was performed to all the rats by injection of 37 MBq Tc-99m DTPA from the tail vein in a dynamic manner. Brain death of the rats was achieved by inflation of a Fogartys catheter in the cranial cavity. Immediately, after brain death confirmation, dynamic renal scintigraphy was performed with the same parameters of control scintigraphy. In the comparison of scintigraphies obtained in the before and just after brain death period, there was impairment of tubular functions, concentration and excretion functions in the postbrain death period. In the immediate postbrain death period, there was a significant elevation in the glomerular filtration rate and time to maximum concentration values. In the histopathological evaluation of the kidney samples in the postbrain death period, there were definitive findings of tubular impairment. Dynamic renal scintigraphy also demonstrated definite impairment of tubular system and tubular functions in the deceased donor kidneys. This could explain the reason of the increased frequency of acute tubular necrosis seen among deceased donor kidneys.

  9. Microsphere estimates of blood flow: Methodological considerations

    International Nuclear Information System (INIS)

    von Ritter, C.; Hinder, R.A.; Womack, W.; Bauerfeind, P.; Fimmel, C.J.; Kvietys, P.R.; Granger, D.N.; Blum, A.L.

    1988-01-01

    The microsphere technique is a standard method for measuring blood flow in experimental animals. Sporadic reports have appeared outlining the limitations of this method. In this study the authors have systematically assessed the effect of blood withdrawals for reference sampling, microsphere numbers, and anesthesia on blood flow estimates using radioactive microspheres in dogs. Experiments were performed on 18 conscious and 12 anesthetized dogs. Four blood flow estimates were performed over 120 min using 1 x 10 6 microspheres each time. The effects of excessive numbers of microspheres pentobarbital sodium anesthesia, and replacement of volume loss for reference samples with dextran 70 were assessed. In both conscious and anesthetized dogs a progressive decrease in gastric mucosal blood flow and cardiac output was observed over 120 min. This was also observed in the pancreas in conscious dogs. The major factor responsible for these changes was the volume loss due to the reference sample withdrawals. Replacement of the withdrawn blood with dextran 70 led to stable blood flows to all organs. The injection of excessive numbers of microspheres did not modify hemodynamics to a greater extent than did the injection of 4 million microspheres. Anesthesia exerted no influence on blood flow other than raising coronary flow. The authors conclude that although blood flow to the gastric mucosa and the pancreas is sensitive to the minor hemodynamic changes associated with the microsphere technique, replacement of volume loss for reference samples ensures stable blood flow to all organs over a 120-min period

  10. Estimating the risk of parvovirus B19 infection in blood donors and pregnant women in Japan.

    Directory of Open Access Journals (Sweden)

    Koji Nabae

    Full Text Available BACKGROUND: Seroepidemiological study of parvovirus B19 has not taken place for some 20 years in Japan. To estimate the risk of parvovirus B19 infection in Japan among blood donors and pregnant women in this century, a seroepidemiological survey and statistical modeling of the force of infection were conducted. METHODOLOGY/PRINCIPAL FINDINGS: The time- and age-specific seroprevalence data were suggestive of strong age-dependency in the risk of infection. Employing a piecewise constant model, the highest forces of infection of 0.05 and 0.12 per year were observed among those aged 0-4 and 5-9 years, respectively, while estimates among older individuals were less than 0.01 per year. Analyzing the antigen detection data among blood donors, the age-specific proportion positive was highest among those aged 30-39 years, agreeing with the presence of dip in seroprevalence in this age-group. Among pregnant women, up to 107 fetal deaths and 21 hydrops fetalis were estimated to have occurred annually across Japan. CONCLUSIONS: Seroepidemiological profiles of PVB19 infection in Japan was characterized with particular emphasis on the risk of infection in blood donors and the burden of infection among pregnant women. When a vaccine becomes available in the future, a similar seroepidemiological study is expected to play a key role in planning the appropriate immunization policy.

  11. Estimation of the basicity of the donor strength of terminal groups in cationic polymethine dyes

    Science.gov (United States)

    Kachkovsky, Alexey; Obernikhina, Nataliya; Prostota, Yaroslav; Naumenko, Antonina; Melnyk, Dmitriy; Yashchuk, Valeriy

    2018-02-01

    The well-known conception of the basicity of the terminal groups in the cationic polymethine dyes showing their donor properties is examined (considered) in detail. The various approachs are proposed to quantitative quantum-chemical estimation of a donor strength of the terminal groups in cationic polymethine dyes: shift of the frontier levels upon introducing terminal residues in comparison with unsybstituted polymethine cation; transferring of the electron density from the terminal groups to the polymethine chain and hence manifested itself as a redistribution of total positive charge between molecular fragments; changes of the charge alternation at carbon atoms along the chain. All approach correlate between them and agree with the concept of the basicity as a capability of terminal heterocycles to show its donor properties in the polymethine dyes. The results of the fulfilled calculations of numerous examples are presented; the proposed parameters point correctly the tendency in the change donor strength upon varying of the chemical constitution: the dimension of cycle, introducing of various heteroatoms, linear or angular annelating by benzene ring; as well as direct to take into consideration the existence of local levels.

  12. Emerging infectious disease outbreaks: estimating disease risk in Australian blood donors travelling overseas.

    Science.gov (United States)

    Coghlan, A; Hoad, V C; Seed, C R; Flower, R Lp; Harley, R J; Herbert, D; Faddy, H M

    2018-01-01

    International travel assists spread of infectious pathogens. Australians regularly travel to South-eastern Asia and the isles of the South Pacific, where they may become infected with infectious agents, such as dengue (DENV), chikungunya (CHIKV) and Zika (ZIKV) viruses that pose a potential risk to transfusion safety. In Australia, donors are temporarily restricted from donating for fresh component manufacture following travel to many countries, including those in this study. We aimed to estimate the unmitigated transfusion-transmission (TT) risk from donors travelling internationally to areas affected by emerging infectious diseases. We used the European Up-Front Risk Assessment Tool, with travel and notification data, to estimate the TT risk from donors travelling to areas affected by disease outbreaks: Fiji (DENV), Bali (DENV), Phuket (DENV), Indonesia (CHIKV) and French Polynesia (ZIKV). We predict minimal risk from travel, with the annual unmitigated risk of an infected component being released varying from 1 in 1·43 million to disease outbreak areas to source plasma collection provides a simple and effective risk management approach. © 2017 International Society of Blood Transfusion.

  13. Estimating the risk of dengue transmission from Dutch blood donors travelling to Suriname and the Dutch Caribbean.

    Science.gov (United States)

    Oei, W; Lieshout-Krikke, R W; Kretzschmar, M E; Zaaijer, H L; Coutinho, R A; Eersel, M; Jubithana, B; Halabi, Y; Gerstenbluth, I; Maduro, E; Tromp, M; Janssen, M P

    2016-05-01

    The risk of dengue transmitted by travellers is known. Methods to estimate the transmission by transfusion (TT) risk from blood donors travelling to risk areas are available, for instance, the European Up-Front Risk Assessment Tool (EUFRAT). This study aimed to validate the estimated risk from travelling donors obtained from EUFRAT. Surveillance data on notified dengue cases in Suriname and the Dutch Caribbean islands (Aruba, Curaçao, St. Maarten, Bonaire, St. Eustatius and Saba) in 2001-2011 was used to calculate local incidence rates. Information on travel and donation behaviour of Dutch donors was collected. With the EUFRAT model, the TT risks from Dutch travelling donors were calculated. Model estimates were compared with the number of infections in Dutch travellers found by laboratory tests in the Netherlands. The expected cumulative number of donors becoming infected during travels to Suriname and the Dutch Caribbean from 2001 to 2011 was estimated at 5 (95% CI, 2-11) and 86 (45-179), respectively. The infection risk inferred from the laboratory-based study was 19 (9-61) and 28 (14-92). Given the independence of the data sources, these estimates are remarkably close. The model estimated that 0·02 (0·001-0·06) and 0·40 (0·01-1·4) recipients would have been infected by these travelling donors. The EUFRAT model provided an estimate close to actual observed number of dengue infections. The dengue TT risk among Dutch travelling donors can be estimated using basic transmission, travel and donation information. The TT risk from Dutch donors travelling to Suriname and the Dutch Caribbean is small. © 2016 International Society of Blood Transfusion.

  14. OPTICAL FLOW FOR GLACIER MOTION ESTIMATION

    Directory of Open Access Journals (Sweden)

    C. Vogel

    2012-07-01

    Full Text Available Quantitative measurements of glacier flow over time are an important ingredient for glaciological research, for example to determine the mass balances and the evolution of glaciers. Measuring glacier flow in multi-temporal images involves the estimation of a dense set of corresponding points, which in turn define the flow vectors. Furthermore glaciers exhibit rather difficult radiometry, since their surface usually contains homogeneous areas as well as weak texture and contrast. To date glacier flow is usually observed by manually measuring a sparse set of correspondences, which is labor-intensive and often yields rather irregular point distributions, with the associated problems of interpolating over large areas. In the present work we propose to densely compute motion vectors at every pixel, by using recent robust methods for optic flow computation. Determining the optic flow, i.e. the dense deformation field between two images of a dynamic scene, has been a classic, long-standing research problem in computer vision and image processing. Sophisticated methods exist to optimally balance data fidelity with smoothness of the motion field. Depending on the strength of the local image gradients these methods yield a smooth trade-off between matching and interpolation, thereby avoiding the somewhat arbitrary decision which discrete anchor points to measure, while at the same time mitigating the problem of gross matching errors. We evaluate our method by comparing with manually measured point wise ground truth.

  15. Directional Transverse Oscillation Vector Flow Estimation

    DEFF Research Database (Denmark)

    Jensen, Jørgen Arendt

    2017-01-01

    A method for estimating vector velocities using transverse oscillation (TO) combined with directional beamforming is presented. In Directional Transverse Oscillation (DTO) a normal focused field is emitted and the received signals are beamformed in the lateral direction transverse to the ultrasound...... beam to increase the amount of data for vector velocity estimation. The approach is self-calibrating as the lateral oscillation period is estimated from the directional signal through a Fourier transform to yield quantitative velocity results over a large range of depths. The approach was extensively...... simulated using Field IIpro and implemented on the experimental SARUS scanner in connection with a BK Medical 8820e convex array transducer. Velocity estimates for DTO are found for beam-to-flow angles of 60, 75, and 90, and vessel depths from 24 to 156 mm. Using 16 emissions the Standard Deviation (SD...

  16. Preoperative computed tomography volumetry and graft weight estimation in adult living donor liver transplantation

    Energy Technology Data Exchange (ETDEWEB)

    Pinheiro, Rafael S.; Cruz Junior, Ruy J.; Andraus, Wellington; Ducatti, Liliana; Martino, Rodrigo B.; Nacif, Lucas S.; Rocha-Santos, Vinicius; Arantes, Rubens M.; D' Albuquerque, Luiz A.C., E-mail: rsnpinheiro@gmail.com [Universidade de Sao Paulo (USP), SP (Brazil). Dept. de Gastroenterologia. Div. de Transplante de Orgaos do Aparelho Digestivo; Lai, Quirino [Universidade de L' Aquila, San Salvatore Hospital (Italy); Ibuki, Felicia S.; Rocha, Manoel S. [Universidade de Sao Paulo (USP), SP (Brazil). Departamento de Radiologia

    2017-09-01

    Background: Computed tomography volumetry (CTV) is a useful tool for predicting graft weights (GW) for living donor liver transplantation (LDLT). Few studies have examined the correlation between CTV and GW in normal liver parenchyma. Aim: To analyze the correlation between CTV and GW in an adult LDLT population and provide a systematic review of the existing mathematical models to calculate partial liver graft weight. Methods: Between January 2009 and January 2013, 28 consecutive donors undergoing right hepatectomy for LDLT were retrospectively reviewed. All grafts were perfused with HTK solution. Estimated graft volume was estimated by CTV and these values were compared to the actual graft weight, which was measured after liver harvesting and perfusion. Results: Median actual GW was 782.5 g, averaged 791.43±136 g and ranged from 520-1185 g. Median estimated graft volume was 927.5 ml, averaged 944.86±200.74 ml and ranged from 600-1477 ml. Linear regression of estimated graft volume and actual GW was significantly linear (GW=0.82 estimated graft volume, r{sup 2} =0.98, slope=0.47, standard deviation of 0.024 and p<0.0001). Spearman Linear correlation was 0.65 with 95% CI of 0.45 – 0.99 (p<0.0001). Conclusion: The one-to-one rule did not applied in patients with normal liver parenchyma. A better estimation of graft weight could be reached by multiplying estimated graft volume by 0.82. (author)

  17. Preoperative computed tomography volumetry and graft weight estimation in adult living donor liver transplantation

    International Nuclear Information System (INIS)

    Pinheiro, Rafael S.; Cruz Junior, Ruy J.; Andraus, Wellington; Ducatti, Liliana; Martino, Rodrigo B.; Nacif, Lucas S.; Rocha-Santos, Vinicius; Arantes, Rubens M.; D'Albuquerque, Luiz A.C.; Ibuki, Felicia S.; Rocha, Manoel S.

    2017-01-01

    Background: Computed tomography volumetry (CTV) is a useful tool for predicting graft weights (GW) for living donor liver transplantation (LDLT). Few studies have examined the correlation between CTV and GW in normal liver parenchyma. Aim: To analyze the correlation between CTV and GW in an adult LDLT population and provide a systematic review of the existing mathematical models to calculate partial liver graft weight. Methods: Between January 2009 and January 2013, 28 consecutive donors undergoing right hepatectomy for LDLT were retrospectively reviewed. All grafts were perfused with HTK solution. Estimated graft volume was estimated by CTV and these values were compared to the actual graft weight, which was measured after liver harvesting and perfusion. Results: Median actual GW was 782.5 g, averaged 791.43±136 g and ranged from 520-1185 g. Median estimated graft volume was 927.5 ml, averaged 944.86±200.74 ml and ranged from 600-1477 ml. Linear regression of estimated graft volume and actual GW was significantly linear (GW=0.82 estimated graft volume, r"2 =0.98, slope=0.47, standard deviation of 0.024 and p<0.0001). Spearman Linear correlation was 0.65 with 95% CI of 0.45 – 0.99 (p<0.0001). Conclusion: The one-to-one rule did not applied in patients with normal liver parenchyma. A better estimation of graft weight could be reached by multiplying estimated graft volume by 0.82. (author)

  18. PREOPERATIVE COMPUTED TOMOGRAPHY VOLUMETRY AND GRAFT WEIGHT ESTIMATION IN ADULT LIVING DONOR LIVER TRANSPLANTATION

    Science.gov (United States)

    PINHEIRO, Rafael S.; CRUZ-JR, Ruy J.; ANDRAUS, Wellington; DUCATTI, Liliana; MARTINO, Rodrigo B.; NACIF, Lucas S.; ROCHA-SANTOS, Vinicius; ARANTES, Rubens M; LAI, Quirino; IBUKI, Felicia S.; ROCHA, Manoel S.; D´ALBUQUERQUE, Luiz A. C.

    2017-01-01

    ABSTRACT Background: Computed tomography volumetry (CTV) is a useful tool for predicting graft weights (GW) for living donor liver transplantation (LDLT). Few studies have examined the correlation between CTV and GW in normal liver parenchyma. Aim: To analyze the correlation between CTV and GW in an adult LDLT population and provide a systematic review of the existing mathematical models to calculate partial liver graft weight. Methods: Between January 2009 and January 2013, 28 consecutive donors undergoing right hepatectomy for LDLT were retrospectively reviewed. All grafts were perfused with HTK solution. Estimated graft volume was estimated by CTV and these values were compared to the actual graft weight, which was measured after liver harvesting and perfusion. Results: Median actual GW was 782.5 g, averaged 791.43±136 g and ranged from 520-1185 g. Median estimated graft volume was 927.5 ml, averaged 944.86±200.74 ml and ranged from 600-1477 ml. Linear regression of estimated graft volume and actual GW was significantly linear (GW=0.82 estimated graft volume, r2=0.98, slope=0.47, standard deviation of 0.024 and p<0.0001). Spearman Linear correlation was 0.65 with 95% CI of 0.45 - 0.99 (p<0.0001). Conclusion: The one-to-one rule did not applied in patients with normal liver parenchyma. A better estimation of graft weight could be reached by multiplying estimated graft volume by 0.82. PMID:28489167

  19. MRI estimation of total renal volume demonstrates significant association with healthy donor weight

    International Nuclear Information System (INIS)

    Cohen, Emil I.; Kelly, Sarah A.; Edye, Michael; Mitty, Harold A.; Bromberg, Jonathan S.

    2009-01-01

    Purpose: The purpose of this study was to correlate total renal volume (TRV) calculations, obtained through the voxel-count method and ellipsoid formula with various physical characteristics. Materials and methods: MRI reports and physical examination from 210 healthy kidney donors (420 kidneys), on whom renal volumes were obtained using the voxel-count method, were retrospectively reviewed. These values along with ones obtained through a more traditional method (ellipsoid formula) were correlated with subject height, body weight, body mass index (BMI), and age. Results: TRV correlated strongly with body weight (r = 0.7) and to a lesser degree with height, age, or BMI (r = 0.5, -0.2, 0.3, respectively). The left kidney volume was greater than the right, on average (p < 0.001). The ellipsoid formula method over-estimated renal volume by 17% on average which was significant (p < 0.001). Conclusions: Body weight was the physical characteristic which demonstrated the strongest correlation with renal volume in healthy subjects. Given this finding, a formula was derived for estimating the TRV for a given patient based on the his or her weight: TRV = 2.96 x weight (kg) + 113 ± 64.

  20. MDRD or CKD-EPI for glomerular filtration rate estimation in living kidney donors

    Directory of Open Access Journals (Sweden)

    Carla Burballa

    2018-03-01

    Full Text Available Introduction: The evaluation of the measured Glomerular Filtration Rate (mGFR or estimated Glomerular Filtration Rate (eGFR is key in the proper assessment of the renal function of potential kidney donors. We aim to study the correlation between glomerular filtration rate estimation equations and the measured methods for determining renal function. Material and methods: We analyzed the relationship between baseline GFR values measured by Tc-99m-DTPA (diethylene-triamine-pentaacetate and those estimated by the four-variable Modification of Diet in Renal Disease (MDRD4 and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI equations in a series of living donors at our institution. Results: We included 64 donors (70.6% females; mean age 48.3 ± 11 years. Baseline creatinine was 0.8 ± 0.1 mg/dl and it was 1.1 ± 0.2 mg/dl one year after donation. The equations underestimated GFR when measured by Tc99m-DTPA (MDRD4 – 9.4 ± 25 ml/min, P < .05, and CKD-EPI – 4.4 ± 21 ml/min. The correlation between estimation equations and the measured method was superior for CKD-EPI (r = .41; P < .004 than for MDRD4 (r = .27; P < .05. eGFR decreased to 59.6 ± 11 (MDRD4 and 66.2 ± 14 ml/min (CKD-EPI one year after donation. This means a mean eGFR reduction of 28.2 ± 16.7 ml/min (MDRD4 and 27.31 ± 14.4 ml/min (CKD-EPI at one year. Conclusions: In our experience, CKD-EPI is the equation that better correlates with mGFR-Tc99m-DTPA when assessing renal function for donor screening purposes. Resumen: Introducción: El estudio del filtrado glomerular medido (FGm o del estimado (FGe es el eje de la evaluación adecuada de la función renal en la valoración de un potencial donante vivo renal. Nos planteamos estudiar la correlación entre las fórmulas de estimación del FG y los métodos de medición para

  1. Estimation of Centers and Stagnation points in optical flow fields

    DEFF Research Database (Denmark)

    Larsen, Rasmus

    1997-01-01

    In a topological sense fluid flows are characterised by their stagnation points. Given a temporal sequence of images of fluids we will consider the application of local polynomials to the estimation of smooth fluid flow fields. The normal flow at intensity contours is estimated from the local dis...

  2. China's role as a global health donor in Africa: what can we learn from studying under reported resource flows?

    Science.gov (United States)

    Grépin, Karen A; Fan, Victoria Y; Shen, Gordon C; Chen, Lucy

    2014-12-30

    There is a growing recognition of China's role as a global health donor, in particular in Africa, but there have been few systematic studies of the level, destination, trends, or composition of these development finance flows or a comparison of China's engagement as a donor with that of more traditional global health donors. Using newly released data from AidData on China's development finance activities in Africa, developed to track under reported resource flows, we identified 255 health, population, water, and sanitation (HPWS) projects from 2000-2012, which we descriptively analyze by activity sector, recipient country, project type, and planned activity. We compare China's activities to projects from traditional donors using data from the OECD's Development Assistance Committee (DAC) Creditor Reporting System. Since 2000, China increased the number of HPWS projects it supported in Africa and health has increased as a development priority for China. China's contributions are large, ranking it among the top 10 bilateral global health donors to Africa. Over 50% of the HPWS projects target infrastructure, 40% target human resource development, and the provision of equipment and drugs is also common. Malaria is an important disease priority but HIV is not. We find little evidence that China targets health aid preferentially to natural resource rich countries. China is an important global health donor to Africa but contrasts with traditional DAC donors through China's focus on health system inputs and on malaria. Although better data are needed, particularly through more transparent aid data reporting across ministries and agencies, China's approach to South-South cooperation represents an important and distinct source of financial assistance for health in Africa.

  3. Estimation of Dense Image Flow Fields in Fluids

    DEFF Research Database (Denmark)

    Larsen, Rasmus; Conradsen, Knut; Ersbøll, Bjarne Kjær

    or an estimate there-of is known. Estimated flow fields in weather satellite imagery might also be used on an operational basis as inputs to short-term weather prediction. In this article we describe a method for the estimation of dense flow fields. Local measurements of motion are obtained by analysis...

  4. Estimation of Dense Image Flow Fields in Fluids

    DEFF Research Database (Denmark)

    Larsen, Rasmus; Conradsen, Knut; Ersbøll, Bjarne Kjær

    1998-01-01

    or an estimate there-of is known. Estimated flow fields in weather satellite imagery might also be used on an operational basis as inputs to short-term weather prediction. In this article we describe a method for the estimation of dense flow fields. Local measurements of motion are obtained by analysis...

  5. PREOPERATIVE COMPUTED TOMOGRAPHY VOLUMETRY AND GRAFT WEIGHT ESTIMATION IN ADULT LIVING DONOR LIVER TRANSPLANTATION.

    Science.gov (United States)

    Pinheiro, Rafael S; Cruz, Ruy J; Andraus, Wellington; Ducatti, Liliana; Martino, Rodrigo B; Nacif, Lucas S; Rocha-Santos, Vinicius; Arantes, Rubens M; Lai, Quirino; Ibuki, Felicia S; Rocha, Manoel S; D Albuquerque, Luiz A C

    2017-01-01

    Computed tomography volumetry (CTV) is a useful tool for predicting graft weights (GW) for living donor liver transplantation (LDLT). Few studies have examined the correlation between CTV and GW in normal liver parenchyma. To analyze the correlation between CTV and GW in an adult LDLT population and provide a systematic review of the existing mathematical models to calculate partial liver graft weight. Between January 2009 and January 2013, 28 consecutive donors undergoing right hepatectomy for LDLT were retrospectively reviewed. All grafts were perfused with HTK solution. Estimated graft volume was estimated by CTV and these values were compared to the actual graft weight, which was measured after liver harvesting and perfusion. Median actual GW was 782.5 g, averaged 791.43±136 g and ranged from 520-1185 g. Median estimated graft volume was 927.5 ml, averaged 944.86±200.74 ml and ranged from 600-1477 ml. Linear regression of estimated graft volume and actual GW was significantly linear (GW=0.82 estimated graft volume, r2=0.98, slope=0.47, standard deviation of 0.024 and ppeso do enxerto (PE) para o transplante hepático com doador vivo (TFDV). Poucos estudos examinaram a correlação entre o VTC e PE no parênquima hepático normal. Analisar a correlação entre VTC e PE em uma população adulta de doadores para o TFDV e realização de revisão sistemática dos modelos matemáticos existentes para calcular o peso de enxertos hepáticos parciais. Foram revisados retrospectivamente 28 doadores consecutivos submetidos à hepatectomia direita para o TFDV entre janeiro de 2009 a janeiro de 2013. Todos os doadores eram adultos saudáveis ​​com VTC pré-operatório. Os enxertos foram perfundidos com solução de preservação HTK. O volume estimado foi obtido por VTC e estes valores foram comparados com o peso real do enxerto, o qual foi aferido depois da hepatectomia e perfusão do enxerto. A mediana do PE real foi de 782,5 g, média de 791,43±136 g, variando

  6. Donor-estimated GFR as an appropriate criterion for allocation of ECD kidneys into single or dual kidney transplantation.

    Science.gov (United States)

    Snanoudj, R; Rabant, M; Timsit, M O; Karras, A; Savoye, E; Tricot, L; Loupy, A; Hiesse, C; Zuber, J; Kreis, H; Martinez, F; Thervet, E; Méjean, A; Lebret, T; Legendre, C; Delahousse, M

    2009-11-01

    It has been suggested that dual kidney transplantation (DKT) improves outcomes for expanded criteria donor (ECD) kidneys. However, no criteria for allocation to single or dual transplantation have been assessed prospectively. The strategy of DKT remains underused and potentially eligible kidneys are frequently discarded. We prospectively compared 81 DKT and 70 single kidney transplant (SKT) receiving grafts from ECD donors aged >65 years, allocated according to donor estimated glomerular filtration rate (eGFR): DKT if eGFR between 30 and 60 mL/min, SKT if eGFR greater than 60 mL/min. Patient and graft survival were similar in the two groups. In the DKT group, 13/81 patients lost one of their two kidneys due to hemorrhage, arterial or venous thrombosis. Mean eGFR at month 12 was similar in the DKT and SKT groups (47.8 mL/min and 46.4 mL/min, respectively). Simulated allocation of kidneys according to criteria based on day 0 donor parameters such as those described by Remuzzi et al., Andres et al. and UNOS, did not indicate an improvement in 12-month eGFR compared to our allocation based on donor eGFR.

  7. Estimating the Heading Direction Using Normal Flow

    Science.gov (United States)

    1994-01-01

    understood (Faugeras and Maybank 1990), 3 Kinetic Stabilization under the assumption that optic flow or correspon- dence is known with some uncertainty...accelerometers can achieve very It can easily be shown (Koenderink and van Doom high accuracy, the same is not true for inexpensive 1975; Maybank 1985... Maybank . ’Motion from point matches: Multi- just don’t compute normal flow there (see Section 6). plicity of solutions". Int’l J. Computer Vision 4

  8. Estimating the consequences of significant fracture flow at Yucca Mountain

    International Nuclear Information System (INIS)

    Gauthier, J.H.; Wilson, M.L.; Lauffer, F.C.

    1992-01-01

    In this paper a simple model is proposed for investigating the possibility of significant fracture flow at Yucca Mountain, Nevada. The model allows an estimate of the number of flowing fractures at Yucca Mountain based on the size of the fractures and the yearly volume of infiltrating water. Given the number of flowing fractures, the number of waste containers they contact is estimated by a geometric argument. Preliminary results indicate that the larger the flowing fractures, the lower the releases of radionuclides. Also, even with significant fracture flow, releases could be well below the limits set by the Environmental Protection Agency

  9. Estimating the consequences of significant fracture flow at Yucca Mountain

    International Nuclear Information System (INIS)

    Gauthier, J.H.; Wilson, M.L.; Lauffer, F.C.

    1991-01-01

    A simple model is proposed for investigating the possibility of significant fracture flow at Yucca Mountain, Nevada. The model allows an estimate of the number of flowing fractures at Yucca Mountain based on the size of the fractures and the yearly volume of infiltrating water. Given the number of flowing fractures, the number of waste containers they contact is estimated by a geometric argument. Preliminary results indicate that the larger the flowing fractures, the lower the releases of radionuclides. Also, even with significant fracture flow, releases could be well below the limits set by the Environmental Protection Agency

  10. Experimental investigation of transverse flow estimation using transverse oscillation

    DEFF Research Database (Denmark)

    Udesen, Jesper; Jensen, Jørgen Arendt

    2003-01-01

    Conventional ultrasound scanners can only display the blood velocity component parallel to the ultrasound beam. Introducing a laterally oscillating field gives signals from which the transverse velocity component can be estimated using 2:1 parallel receive beamformers. To yield the performance...... perpendicular to the ultrasound beam. The velocity profile of the blood is parabolic, and the speed of the blood in the center of the vessel is 1.1 m/s. An extended autocorrelation algorithm is used for velocity estimation for 310 trials, each containing 32 beamformed signals. The velocity can be estimated.......0% and the relative mean standard deviation is found to be 9.8%. With the Compuflow 1000 programmable flow pump a color flow mode image is produced of the experimental setup for a parabolic flow. Also the flow of the human femoralis is reproduced and it is found that the characteristics of the flow can be estimated....

  11. Renal blood flow using arterial spin labelling MRI and calculated filtration fraction in healthy adult kidney donors Pre-nephrectomy and post-nephrectomy.

    Science.gov (United States)

    Cutajar, Marica; Hilton, Rachel; Olsburgh, Jonathon; Marks, Stephen D; Thomas, David L; Banks, Tina; Clark, Christopher A; Gordon, Isky

    2015-08-01

    Renal plasma flow (RPF) (derived from renal blood flow, RBF) and glomerular filtration rate (GFR) allow the determination of the filtration fraction (FF), which may have a role as a non-invasive renal biomarker. This is a hypothesis-generating pilot study assessing the effect of nephrectomy on renal function in healthy kidney donors. Eight living kidney donors underwent arterial spin labelling (ASL) magnetic resonance imaging (MRI) and GFR measurement prior to and 1 year after nephrectomy. Chromium-51 labelled ethylenediamine tetraacetic acid ((51)Cr-EDTA) with multi-blood sampling was undertaken and GFR calculated. The RBF and GFR obtained were used to calculate FF. All donors showed an increase in single kidney GFR of 24 - 75 %, and all but two showed an increase in FF (-7 to +52 %) after nephrectomy. The increase in RBF, and hence RPF, post-nephrectomy was not as great as the increase in GFR in seven out of eight donors. As with any pilot study, the small number of donors and their relatively narrow age range are potential limiting factors. The ability to measure RBF, and hence RPF, non-invasively, coupled with GFR measurement, allows calculation of FF, a biomarker that might provide a sensitive indicator of loss of renal reserve in potential donors. • Non-invasive MRI measured renal blood flow and calculated renal plasma flow. • Effect of nephrectomy on blood flow and filtration in donors is presented. • Calculated filtration fraction may be a useful new kidney biomarker.

  12. Preliminary evaluation of vector flow and spectral velocity estimation

    DEFF Research Database (Denmark)

    Pedersen, Mads Møller; Pihl, Michael Johannes; Haugaard, Per

    Spectral estimation is considered as the golden standard in ultrasound velocity estimation. For spectral velocity estimation the blood flow angle is set by the ultrasound operator. Vector flow provides temporal and spatial estimates of the blood flow angle and velocity. A comparison of vector flow...... line covering the vessel diameter. A commercial ultrasound scanner (ProFocus 2202, BK Medical, Denmark) and a 7.6 MHz linear transducer was used (8670, BK Medical). The mean vector blood flow angle estimations were calculated {52(18);55(23);60(16)}°. For comparison the fixed angles for spectral...... estimation were obtained {52;56;52}°. The mean vector velocity estimates at PS {76(15);95(17);77(16)}cm/s and at end diastole (ED) {17(6);18(6);24(6)}cm/s were calculated. For comparison spectral velocity estimates at PS {77;110;76}cm/s and ED {18;18;20}cm/s were obtained. The mean vector angle estimates...

  13. Dense Descriptors for Optical Flow Estimation: A Comparative Study

    Directory of Open Access Journals (Sweden)

    Ahmadreza Baghaie

    2017-02-01

    Full Text Available Estimating the displacements of intensity patterns between sequential frames is a very well-studied problem, which is usually referred to as optical flow estimation. The first assumption among many of the methods in the field is the brightness constancy during movements of pixels between frames. This assumption is proven to be not true in general, and therefore, the use of photometric invariant constraints has been studied in the past. One other solution can be sought by use of structural descriptors rather than pixels for estimating the optical flow. Unlike sparse feature detection/description techniques and since the problem of optical flow estimation tries to find a dense flow field, a dense structural representation of individual pixels and their neighbors is computed and then used for matching and optical flow estimation. Here, a comparative study is carried out by extending the framework of SIFT-flow to include more dense descriptors, and comprehensive comparisons are given. Overall, the work can be considered as a baseline for stimulating more interest in the use of dense descriptors for optical flow estimation.

  14. Multiphase flow parameter estimation based on laser scattering

    Science.gov (United States)

    Vendruscolo, Tiago P.; Fischer, Robert; Martelli, Cicero; Rodrigues, Rômulo L. P.; Morales, Rigoberto E. M.; da Silva, Marco J.

    2015-07-01

    The flow of multiple constituents inside a pipe or vessel, known as multiphase flow, is commonly found in many industry branches. The measurement of the individual flow rates in such flow is still a challenge, which usually requires a combination of several sensor types. However, in many applications, especially in industrial process control, it is not necessary to know the absolute flow rate of the respective phases, but rather to continuously monitor flow conditions in order to quickly detect deviations from the desired parameters. Here we show how a simple and low-cost sensor design can achieve this, by using machine-learning techniques to distinguishing the characteristic patterns of oblique laser light scattered at the phase interfaces. The sensor is capable of estimating individual phase fluxes (as well as their changes) in multiphase flows and may be applied to safety applications due to its quick response time.

  15. Multiphase flow parameter estimation based on laser scattering

    International Nuclear Information System (INIS)

    Vendruscolo, Tiago P; Fischer, Robert; Martelli, Cicero; Da Silva, Marco J; Rodrigues, Rômulo L P; Morales, Rigoberto E M

    2015-01-01

    The flow of multiple constituents inside a pipe or vessel, known as multiphase flow, is commonly found in many industry branches. The measurement of the individual flow rates in such flow is still a challenge, which usually requires a combination of several sensor types. However, in many applications, especially in industrial process control, it is not necessary to know the absolute flow rate of the respective phases, but rather to continuously monitor flow conditions in order to quickly detect deviations from the desired parameters. Here we show how a simple and low-cost sensor design can achieve this, by using machine-learning techniques to distinguishing the characteristic patterns of oblique laser light scattered at the phase interfaces. The sensor is capable of estimating individual phase fluxes (as well as their changes) in multiphase flows and may be applied to safety applications due to its quick response time. (paper)

  16. Velocity estimation using synthetic aperture imaging [blood flow

    DEFF Research Database (Denmark)

    Nikolov, Svetoslav; Jensen, Jørgen Arendt

    2001-01-01

    Presented an approach for synthetic aperture blood flow ultrasound imaging. Estimates with a low bias and standard deviation can be obtained with as few as eight emissions. The performance of the new estimator is verified using both simulations and measurements. The results demonstrate that a fully...

  17. An In-vivo investigation of transverse flow estimation

    DEFF Research Database (Denmark)

    Udesen, Jesper; Jensen, Jørgen Arendt

    2004-01-01

    , and 1.4 seconds of data is acquired. Using 2 parallel receive beamformers a transverse oscillation is introduced with an oscillation period 1.2 mm. The velocity estimation is performed using an extended autocorrelation algorithm. The volume flow can be estimated with a relative standard deviation of 13...

  18. Data adaptive estimation of transversal blood flow velocities

    DEFF Research Database (Denmark)

    Pirnia, E.; Jakobsson, A.; Gudmundson, E.

    2014-01-01

    the transversal blood flow. In this paper, we propose a novel data-adaptive blood flow estimator exploiting this modulation scheme. Using realistic Field II simulations, the proposed estimator is shown to achieve a notable performance improvement as compared to current state-of-the-art techniques.......The examination of blood flow inside the body may yield important information about vascular anomalies, such as possible indications of, for example, stenosis. Current Medical ultrasound systems suffer from only allowing for measuring the blood flow velocity along the direction of irradiation......, posing natural difficulties due to the complex behaviour of blood flow, and due to the natural orientation of most blood vessels. Recently, a transversal modulation scheme was introduced to induce also an oscillation along the transversal direction, thereby allowing for the measurement of also...

  19. Rapid estimation of split renal function in kidney donors using software developed for computed tomographic renal volumetry

    International Nuclear Information System (INIS)

    Kato, Fumi; Kamishima, Tamotsu; Morita, Ken; Muto, Natalia S.; Okamoto, Syozou; Omatsu, Tokuhiko; Oyama, Noriko; Terae, Satoshi; Kanegae, Kakuko; Nonomura, Katsuya; Shirato, Hiroki

    2011-01-01

    Purpose: To evaluate the speed and precision of split renal volume (SRV) measurement, which is the ratio of unilateral renal volume to bilateral renal volume, using a newly developed software for computed tomographic (CT) volumetry and to investigate the usefulness of SRV for the estimation of split renal function (SRF) in kidney donors. Method: Both dynamic CT and renal scintigraphy in 28 adult potential living renal donors were the subjects of this study. We calculated SRV using the newly developed volumetric software built into a PACS viewer (n-SRV), and compared it with SRV calculated using a conventional workstation, ZIOSOFT (z-SRV). The correlation with split renal function (SRF) using 99m Tc-DMSA scintigraphy was also investigated. Results: The time required for volumetry of bilateral kidneys with the newly developed software (16.7 ± 3.9 s) was significantly shorter than that of the workstation (102.6 ± 38.9 s, p < 0.0001). The results of n-SRV (49.7 ± 4.0%) were highly consistent with those of z-SRV (49.9 ± 3.6%), with a mean discrepancy of 0.12 ± 0.84%. The SRF also agreed well with the n-SRV, with a mean discrepancy of 0.25 ± 1.65%. The dominant side determined by SRF and n-SRV showed agreement in 26 of 28 cases (92.9%). Conclusion: The newly developed software for CT volumetry was more rapid than the conventional workstation volumetry and just as accurate, and was suggested to be useful for the estimation of SRF and thus the dominant side in kidney donors.

  20. Rapid estimation of split renal function in kidney donors using software developed for computed tomographic renal volumetry

    Energy Technology Data Exchange (ETDEWEB)

    Kato, Fumi, E-mail: fumikato@med.hokudai.ac.jp [Department of Radiology, Hokkaido University Graduate School of Medicine, N15, W7, Kita-ku, Sapporo, Hokkaido 060-8638 (Japan); Kamishima, Tamotsu, E-mail: ktamotamo2@yahoo.co.jp [Department of Radiology, Hokkaido University Graduate School of Medicine, N15, W7, Kita-ku, Sapporo, Hokkaido 060-8638 (Japan); Morita, Ken, E-mail: kenordic@carrot.ocn.ne.jp [Department of Urology, Hokkaido University Graduate School of Medicine, N15, W7, Kita-ku, Sapporo, 060-8638 (Japan); Muto, Natalia S., E-mail: nataliamuto@gmail.com [Department of Radiology, Hokkaido University Graduate School of Medicine, N15, W7, Kita-ku, Sapporo, Hokkaido 060-8638 (Japan); Okamoto, Syozou, E-mail: shozo@med.hokudai.ac.jp [Department of Nuclear Medicine, Hokkaido University Graduate School of Medicine, N15, W7, Kita-ku, Sapporo, 060-8638 (Japan); Omatsu, Tokuhiko, E-mail: omatoku@nirs.go.jp [Department of Radiology, Hokkaido University Graduate School of Medicine, N15, W7, Kita-ku, Sapporo, Hokkaido 060-8638 (Japan); Oyama, Noriko, E-mail: ZAT04404@nifty.ne.jp [Department of Radiology, Hokkaido University Graduate School of Medicine, N15, W7, Kita-ku, Sapporo, Hokkaido 060-8638 (Japan); Terae, Satoshi, E-mail: saterae@med.hokudai.ac.jp [Department of Radiology, Hokkaido University Graduate School of Medicine, N15, W7, Kita-ku, Sapporo, Hokkaido 060-8638 (Japan); Kanegae, Kakuko, E-mail: IZW00143@nifty.ne.jp [Department of Nuclear Medicine, Hokkaido University Graduate School of Medicine, N15, W7, Kita-ku, Sapporo, 060-8638 (Japan); Nonomura, Katsuya, E-mail: k-nonno@med.hokudai.ac.jp [Department of Urology, Hokkaido University Graduate School of Medicine, N15, W7, Kita-ku, Sapporo, 060-8638 (Japan); Shirato, Hiroki, E-mail: shirato@med.hokudai.ac.jp [Department of Radiology, Hokkaido University Graduate School of Medicine, N15, W7, Kita-ku, Sapporo, Hokkaido 060-8638 (Japan)

    2011-07-15

    Purpose: To evaluate the speed and precision of split renal volume (SRV) measurement, which is the ratio of unilateral renal volume to bilateral renal volume, using a newly developed software for computed tomographic (CT) volumetry and to investigate the usefulness of SRV for the estimation of split renal function (SRF) in kidney donors. Method: Both dynamic CT and renal scintigraphy in 28 adult potential living renal donors were the subjects of this study. We calculated SRV using the newly developed volumetric software built into a PACS viewer (n-SRV), and compared it with SRV calculated using a conventional workstation, ZIOSOFT (z-SRV). The correlation with split renal function (SRF) using {sup 99m}Tc-DMSA scintigraphy was also investigated. Results: The time required for volumetry of bilateral kidneys with the newly developed software (16.7 {+-} 3.9 s) was significantly shorter than that of the workstation (102.6 {+-} 38.9 s, p < 0.0001). The results of n-SRV (49.7 {+-} 4.0%) were highly consistent with those of z-SRV (49.9 {+-} 3.6%), with a mean discrepancy of 0.12 {+-} 0.84%. The SRF also agreed well with the n-SRV, with a mean discrepancy of 0.25 {+-} 1.65%. The dominant side determined by SRF and n-SRV showed agreement in 26 of 28 cases (92.9%). Conclusion: The newly developed software for CT volumetry was more rapid than the conventional workstation volumetry and just as accurate, and was suggested to be useful for the estimation of SRF and thus the dominant side in kidney donors.

  1. Estimation of flow rates through intergranular stress corrosion cracks

    International Nuclear Information System (INIS)

    Collier, R.P.; Norris, D.M.

    1984-01-01

    Experimental studies of critical two-phase water flow, through simulated and actual intergranular stress corrosion cracks, were performed to obtain data to evaluate a leak flow rate model and investigate acoustic transducer effectiveness in detecting and sizing leaks. The experimental program included a parametric study of the effects of crack geometry, fluid stagnation pressure and temperature, and crack surface roughness on leak flow rate. In addition, leak detection, location, and leak size estimation capabilities of several different acoustic transducers were evaluated as functions of leak rate and transducer position. This paper presents flow rate data for several different cracks and fluid conditions. It also presents the minimum flow rate detected with the acoustic sensors and a relationship between acoustic signal strength and leak flow rate

  2. Ten years cardiovascular risk estimation according to Framingham score and non HDL-cholesterol in blood donors.

    Science.gov (United States)

    Graffigna, Mabel Nora; Berg, Gabriela; Migliano, Marta; Salgado, Pablo; Soutelo, Jimena; Musso, Carla

    2015-01-01

    Cardiovascular disease (CVD) is currently the primary cause of morbidity and mortality. (1) Assess the 10 years risk for CVD in Argentinean blood donors, according to Framingham score (updated by ATP III), (2) evaluate the prevalence of the MS, (3) evaluate non HDL-cholesterol level in this population as other risk for CVD. A prospective, epidemiological, transversal study was performed to evaluate 585 volunteer blood donors for two years. Non HDL-C was calculated as total cholesterol minus HDL-C and we evaluated the 10 years risk for CVD according to Framingham score (updated by ATP III). Metabolic syndrome prevalence was estimated according to ATP III and IDF criteria. Non HDL-C was (media±SD) 178.3±48.0 mg/dl in participants with MS and 143.7±39.3 mg/dl without MS (ATPIII) and 160.1±43.6 mg/dl in participants with MS and 139.8±43.1 mg/dl without MS (IDF). Participants with MS presented an OR of 3.1; IC 95% (2-5) of CVD according to de Framingham score. Individuals with MS and elevated non HDL-C are at a higher estimated risk for cardiovascular events in the next 10 years according to the Framingham risk score. Copyright © 2014. Published by Elsevier Ltd.

  3. Coded Ultrasound for Blood Flow Estimation Using Subband Processing

    DEFF Research Database (Denmark)

    Gran, Fredrik; Udesen, Jesper; Nielsen, Michael Bachamnn

    2008-01-01

    the excitation signal is broadband and has good spatial resolution after pulse compression. This means that time can be saved by using the same data for B-mode imaging and blood flow estimation. Two different coding schemes are used in this paper, Barker codes and Golay codes. The performance of the codes......This paper investigates the use of coded excitation for blood flow estimation in medical ultrasound. Traditional autocorrelation estimators use narrow-band excitation signals to provide sufficient signal-to-noise-ratio (SNR) and velocity estimation performance. In this paper, broadband coded...... signals are used to increase SNR, followed by subband processing. The received broadband signal is filtered using a set of narrow-band filters. Estimating the velocity in each of the bands and averaging the results yields better performance compared with what would be possible when transmitting a narrow...

  4. Ultrasonic 3-D Vector Flow Method for Quantitative In Vivo Peak Velocity and Flow Rate Estimation

    DEFF Research Database (Denmark)

    Holbek, Simon; Ewertsen, Caroline; Bouzari, Hamed

    2017-01-01

    Current clinical ultrasound (US) systems are limited to show blood flow movement in either 1-D or 2-D. In this paper, a method for estimating 3-D vector velocities in a plane using the transverse oscillation method, a 32×32 element matrix array, and the experimental US scanner SARUS is presented...... is validated in two phantom studies, where flow rates are measured in a flow-rig, providing a constant parabolic flow, and in a straight-vessel phantom ( ∅=8 mm) connected to a flow pump capable of generating time varying waveforms. Flow rates are estimated to be 82.1 ± 2.8 L/min in the flow-rig compared...

  5. Self Calibrating Flow Estimation in Waste Water Pumping Stations

    DEFF Research Database (Denmark)

    Kallesøe, Carsten Skovmose; Knudsen, Torben

    2016-01-01

    Knowledge about where waste water is flowing in waste water networks is essential to optimize the operation of the network pumping stations. However, installation of flow sensors is expensive and requires regular maintenance. This paper proposes an alternative approach where the pumps and the waste...... water pit are used for estimating both the inflow and the pump flow of the pumping station. Due to the nature of waste water, the waste water pumps are heavily affected by wear and tear. To compensate for the wear of the pumps, the pump parameters, used for the flow estimation, are automatically...... calibrated. This calibration is done based on data batches stored at each pump cycle, hence makes the approach a self calibrating system. The approach is tested on a pumping station operating in a real waste water network....

  6. Cystatin C-Based Equation Does Not Accurately Estimate the Glomerular Filtration in Japanese Living Kidney Donors.

    Science.gov (United States)

    Tsujimura, Kazuma; Ota, Morihito; Chinen, Kiyoshi; Adachi, Takayuki; Nagayama, Kiyomitsu; Oroku, Masato; Nishihira, Morikuni; Shiohira, Yoshiki; Iseki, Kunitoshi; Ishida, Hideki; Tanabe, Kazunari

    2017-06-23

    BACKGROUND Precise evaluation of a living donor's renal function is necessary to ensure adequate residual kidney function after donor nephrectomy. Our aim was to evaluate the feasibility of estimating glomerular filtration rate (GFR) using serum cystatin-C prior to kidney transplantation. MATERIAL AND METHODS Using the equations of the Japanese Society of Nephrology, we calculated the GFR using serum creatinine (eGFRcre) and cystatin C levels (eGFRcys) for 83 living kidney donors evaluated between March 2010 and March 2016. We compared eGFRcys and eGFRcre values against the creatinine clearance rate (CCr). RESULTS The study population included 27 males and 56 females. The mean eGFRcys, eGFRcre, and CCr were, 91.4±16.3 mL/min/1.73 m² (range, 59.9-128.9 mL/min/1.73 m²), 81.5±14.2 mL/min/1.73 m² (range, 55.4-117.5 mL/min/1.73 m²) and 108.4±21.6 mL/min/1.73 m² (range, 63.7-168.7 mL/min/1.73 m²), respectively. eGFRcys was significantly lower than CCr (p<0.001). The correlation coefficient between eGFRcys and CCr values was 0.466, and the mean difference between the two values was -17.0 (15.7%), with a root mean square error of 19.2. Thus, eGFRcre was significantly lower than CCr (p<0.001). The correlation coefficient between eGFRcre and CCr values was 0.445, and the mean difference between the two values was -26.9 (24.8%), with a root mean square error of 19.5. CONCLUSIONS Although eGFRcys provided a better estimation of GFR than eGFRcre, eGFRcys still did not provide an accurate measure of kidney function in Japanese living kidney donors.

  7. Maximum Likelihood Blood Velocity Estimator Incorporating Properties of Flow Physics

    DEFF Research Database (Denmark)

    Schlaikjer, Malene; Jensen, Jørgen Arendt

    2004-01-01

    )-data under investigation. The flow physic properties are exploited in the second term, as the range of velocity values investigated in the cross-correlation analysis are compared to the velocity estimates in the temporal and spatial neighborhood of the signal segment under investigation. The new estimator...... has been compared to the cross-correlation (CC) estimator and the previously developed maximum likelihood estimator (MLE). The results show that the CMLE can handle a larger velocity search range and is capable of estimating even low velocity levels from tissue motion. The CC and the MLE produce...... for the CC and the MLE. When the velocity search range is set to twice the limit of the CC and the MLE, the number of incorrect velocity estimates are 0, 19.1, and 7.2% for the CMLE, CC, and MLE, respectively. The ability to handle a larger search range and estimating low velocity levels was confirmed...

  8. Optical flow estimation on image sequences with differently exposed frames

    Science.gov (United States)

    Bengtsson, Tomas; McKelvey, Tomas; Lindström, Konstantin

    2015-09-01

    Optical flow (OF) methods are used to estimate dense motion information between consecutive frames in image sequences. In addition to the specific OF estimation method itself, the quality of the input image sequence is of crucial importance to the quality of the resulting flow estimates. For instance, lack of texture in image frames caused by saturation of the camera sensor during exposure can significantly deteriorate the performance. An approach to avoid this negative effect is to use different camera settings when capturing the individual frames. We provide a framework for OF estimation on such sequences that contain differently exposed frames. Information from multiple frames are combined into a total cost functional such that the lack of an active data term for saturated image areas is avoided. Experimental results demonstrate that using alternate camera settings to capture the full dynamic range of an underlying scene can clearly improve the quality of flow estimates. When saturation of image data is significant, the proposed methods show superior performance in terms of lower endpoint errors of the flow vectors compared to a set of baseline methods. Furthermore, we provide some qualitative examples of how and when our method should be used.

  9. Methods for estimating low-flow statistics for Massachusetts streams

    Science.gov (United States)

    Ries, Kernell G.; Friesz, Paul J.

    2000-01-01

    Methods and computer software are described in this report for determining flow duration, low-flow frequency statistics, and August median flows. These low-flow statistics can be estimated for unregulated streams in Massachusetts using different methods depending on whether the location of interest is at a streamgaging station, a low-flow partial-record station, or an ungaged site where no data are available. Low-flow statistics for streamgaging stations can be estimated using standard U.S. Geological Survey methods described in the report. The MOVE.1 mathematical method and a graphical correlation method can be used to estimate low-flow statistics for low-flow partial-record stations. The MOVE.1 method is recommended when the relation between measured flows at a partial-record station and daily mean flows at a nearby, hydrologically similar streamgaging station is linear, and the graphical method is recommended when the relation is curved. Equations are presented for computing the variance and equivalent years of record for estimates of low-flow statistics for low-flow partial-record stations when either a single or multiple index stations are used to determine the estimates. The drainage-area ratio method or regression equations can be used to estimate low-flow statistics for ungaged sites where no data are available. The drainage-area ratio method is generally as accurate as or more accurate than regression estimates when the drainage-area ratio for an ungaged site is between 0.3 and 1.5 times the drainage area of the index data-collection site. Regression equations were developed to estimate the natural, long-term 99-, 98-, 95-, 90-, 85-, 80-, 75-, 70-, 60-, and 50-percent duration flows; the 7-day, 2-year and the 7-day, 10-year low flows; and the August median flow for ungaged sites in Massachusetts. Streamflow statistics and basin characteristics for 87 to 133 streamgaging stations and low-flow partial-record stations were used to develop the equations. The

  10. Renal blood flow using arterial spin labelling MRI and calculated filtration fraction in healthy adult kidney donors pre-nephrectomy and post-nephrectomy

    Energy Technology Data Exchange (ETDEWEB)

    Cutajar, Marica; Clark, Christopher A.; Gordon, Isky [University College London, Imaging and Biophysics Unit, Institute of Child Health, London (United Kingdom); Hilton, Rachel; Olsburgh, Jonathon [Renal Unit, Guy' s and St Thomas' NHS Foundation Trust, London (United Kingdom); Marks, Stephen D. [Great Ormond Street Hospital for Children NHS Foundation Trust, Department of Paediatric Nephrology, London (United Kingdom); Thomas, David L. [University College London, Department of Brain Repair and Rehabilitation, Institute of Neurology, London (United Kingdom); Banks, Tina [Great Ormond Street Hospital for Children NHS Foundation Trust, Department of Radiology, London (United Kingdom)

    2015-08-15

    Renal plasma flow (RPF) (derived from renal blood flow, RBF) and glomerular filtration rate (GFR) allow the determination of the filtration fraction (FF), which may have a role as a non-invasive renal biomarker. This is a hypothesis-generating pilot study assessing the effect of nephrectomy on renal function in healthy kidney donors. Eight living kidney donors underwent arterial spin labelling (ASL) magnetic resonance imaging (MRI) and GFR measurement prior to and 1 year after nephrectomy. Chromium-51 labelled ethylenediamine tetraacetic acid ({sup 51}Cr-EDTA) with multi-blood sampling was undertaken and GFR calculated. The RBF and GFR obtained were used to calculate FF. All donors showed an increase in single kidney GFR of 24 - 75 %, and all but two showed an increase in FF (-7 to +52 %) after nephrectomy. The increase in RBF, and hence RPF, post-nephrectomy was not as great as the increase in GFR in seven out of eight donors. As with any pilot study, the small number of donors and their relatively narrow age range are potential limiting factors. The ability to measure RBF, and hence RPF, non-invasively, coupled with GFR measurement, allows calculation of FF, a biomarker that might provide a sensitive indicator of loss of renal reserve in potential donors. (orig.)

  11. Renal blood flow using arterial spin labelling MRI and calculated filtration fraction in healthy adult kidney donors pre-nephrectomy and post-nephrectomy

    International Nuclear Information System (INIS)

    Cutajar, Marica; Clark, Christopher A.; Gordon, Isky; Hilton, Rachel; Olsburgh, Jonathon; Marks, Stephen D.; Thomas, David L.; Banks, Tina

    2015-01-01

    Renal plasma flow (RPF) (derived from renal blood flow, RBF) and glomerular filtration rate (GFR) allow the determination of the filtration fraction (FF), which may have a role as a non-invasive renal biomarker. This is a hypothesis-generating pilot study assessing the effect of nephrectomy on renal function in healthy kidney donors. Eight living kidney donors underwent arterial spin labelling (ASL) magnetic resonance imaging (MRI) and GFR measurement prior to and 1 year after nephrectomy. Chromium-51 labelled ethylenediamine tetraacetic acid ( 51 Cr-EDTA) with multi-blood sampling was undertaken and GFR calculated. The RBF and GFR obtained were used to calculate FF. All donors showed an increase in single kidney GFR of 24 - 75 %, and all but two showed an increase in FF (-7 to +52 %) after nephrectomy. The increase in RBF, and hence RPF, post-nephrectomy was not as great as the increase in GFR in seven out of eight donors. As with any pilot study, the small number of donors and their relatively narrow age range are potential limiting factors. The ability to measure RBF, and hence RPF, non-invasively, coupled with GFR measurement, allows calculation of FF, a biomarker that might provide a sensitive indicator of loss of renal reserve in potential donors. (orig.)

  12. Coded ultrasound for blood flow estimation using subband processing

    DEFF Research Database (Denmark)

    Gran, Fredrik; Udesen, Jesper; Nielsen, Michael bachmann

    2007-01-01

    This paper further investigates the use of coded excitation for blood flow estimation in medical ultrasound. Traditional autocorrelation estimators use narrow-band excitation signals to provide sufficient signal-to-noise-ratio (SNR) and velocity estimation performance. In this paper, broadband...... coded signals are used to increase SNR, followed by sub-band processing. The received broadband signal, is filtered using a set of narrow-band filters. Estimating the velocity in each of the bands and averaging the results yields better performance compared to what would be possible when transmitting...... a narrow-band pulse directly. Also, the spatial resolution of the narrow-band pulse would be too poor for brightness-mode (B-mode) imaging and additional transmissions would be required to update the B-mode image. In the described approach, there is no need for additional transmissions, because...

  13. Synthesis of Donor/Acceptor-Substituted Diazo Compounds in Flow and Their Application in Enantioselective Dirhodium-Catalyzed Cyclopropanation and C-H Functionalization.

    Science.gov (United States)

    Rackl, Daniel; Yoo, Chun-Jae; Jones, Christopher W; Davies, Huw M L

    2017-06-16

    A tandem reaction system has been developed for the preparation of donor/acceptor-substituted diazo compounds in continuous flow coupled to dirhodium-catalyzed C-H functionalization or cyclopropanation. Hydrazones were oxidized in flow by solid-supported N-iodo-p-toluenesulfonamide potassium salt (PS-SO 2 NIK) to generate the diazo compounds, which were then purified by passing through a column of molecular sieves/sodium thiosulfate.

  14. Monocular distance estimation from optic flow during active landing maneuvers

    International Nuclear Information System (INIS)

    Van Breugel, Floris; Morgansen, Kristi; Dickinson, Michael H

    2014-01-01

    Vision is arguably the most widely used sensor for position and velocity estimation in animals, and it is increasingly used in robotic systems as well. Many animals use stereopsis and object recognition in order to make a true estimate of distance. For a tiny insect such as a fruit fly or honeybee, however, these methods fall short. Instead, an insect must rely on calculations of optic flow, which can provide a measure of the ratio of velocity to distance, but not either parameter independently. Nevertheless, flies and other insects are adept at landing on a variety of substrates, a behavior that inherently requires some form of distance estimation in order to trigger distance-appropriate motor actions such as deceleration or leg extension. Previous studies have shown that these behaviors are indeed under visual control, raising the question: how does an insect estimate distance solely using optic flow? In this paper we use a nonlinear control theoretic approach to propose a solution for this problem. Our algorithm takes advantage of visually controlled landing trajectories that have been observed in flies and honeybees. Finally, we implement our algorithm, which we term dynamic peering, using a camera mounted to a linear stage to demonstrate its real-world feasibility. (paper)

  15. Improving chemical species tomography of turbulent flows using covariance estimation.

    Science.gov (United States)

    Grauer, Samuel J; Hadwin, Paul J; Daun, Kyle J

    2017-05-01

    Chemical species tomography (CST) experiments can be divided into limited-data and full-rank cases. Both require solving ill-posed inverse problems, and thus the measurement data must be supplemented with prior information to carry out reconstructions. The Bayesian framework formalizes the role of additive information, expressed as the mean and covariance of a joint-normal prior probability density function. We present techniques for estimating the spatial covariance of a flow under limited-data and full-rank conditions. Our results show that incorporating a covariance estimate into CST reconstruction via a Bayesian prior increases the accuracy of instantaneous estimates. Improvements are especially dramatic in real-time limited-data CST, which is directly applicable to many industrially relevant experiments.

  16. Nitrite accumulation in continuous-flow partial autotrophic denitrification reactor using sulfide as electron donor.

    Science.gov (United States)

    Liu, Chunshuang; Li, Wenfei; Li, Xuechen; Zhao, Dongfeng; Ma, Bin; Wang, Yongqiang; Liu, Fang; Lee, Duu-Jong

    2017-11-01

    The nitrite accumulation in handling nitrate and sulfide-laden wastewater in a continuous-flow upflow anaerobic sludge blanket reactor was studied. At sulfide/nitrate-nitrogen ratio of 1:0.76 and loading rates of 1.2kg-Sm -3 d -1 and 0.4kg-Nm -3 d -1 , the elemental sulfur and nitrite accumulation rates peaked at 90% and 70%, respectively, with Acrobacter, Azoarcus and Thauera presenting the functional strains in the studied reactor. The accumulated nitrite was proposed a promising feedstock for anaerobic ammonia oxidation process. An integrated partial autotrophic denitrification-anaerobic ammonia oxidation-aeration process for handling the ammonia and sulfide-laden wastewaters is proposed for further studies. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Discharge estimation combining flow routing and occasional measurements of velocity

    Directory of Open Access Journals (Sweden)

    G. Corato

    2011-09-01

    Full Text Available A new procedure is proposed for estimating river discharge hydrographs during flood events, using only water level data at a single gauged site, as well as 1-D shallow water modelling and occasional maximum surface flow velocity measurements. One-dimensional diffusive hydraulic model is used for routing the recorded stage hydrograph in the channel reach considering zero-diffusion downstream boundary condition. Based on synthetic tests concerning a broad prismatic channel, the "suitable" reach length is chosen in order to minimize the effect of the approximated downstream boundary condition on the estimation of the upstream discharge hydrograph. The Manning's roughness coefficient is calibrated by using occasional instantaneous surface velocity measurements during the rising limb of flood that are used to estimate instantaneous discharges by adopting, in the flow area, a two-dimensional velocity distribution model. Several historical events recorded in three gauged sites along the upper Tiber River, wherein reliable rating curves are available, have been used for the validation. The outcomes of the analysis can be summarized as follows: (1 the criterion adopted for selecting the "suitable" channel length based on synthetic test studies has proved to be reliable for field applications to three gauged sites. Indeed, for each event a downstream reach length not more than 500 m is found to be sufficient, for a good performances of the hydraulic model, thereby enabling the drastic reduction of river cross-sections data; (2 the procedure for Manning's roughness coefficient calibration allowed for high performance in discharge estimation just considering the observed water levels and occasional measurements of maximum surface flow velocity during the rising limb of flood. Indeed, errors in the peak discharge magnitude, for the optimal calibration, were found not exceeding 5% for all events observed in the three investigated gauged sections, while the

  18. Influence of Flow Velocity on Tsunami Loss Estimation

    Directory of Open Access Journals (Sweden)

    Jie Song

    2017-11-01

    Full Text Available Inundation depth is commonly used as an intensity measure in tsunami fragility analysis. However, inundation depth cannot be taken as the sole representation of tsunami impact on structures, especially when structural damage is caused by hydrodynamic and debris impact forces that are mainly determined by flow velocity. To reflect the influence of flow velocity in addition to inundation depth in tsunami risk assessment, a tsunami loss estimation method that adopts both inundation depth and flow velocity (i.e., bivariate intensity measures in evaluating tsunami damage is developed. To consider a wide range of possible tsunami inundation scenarios, Monte Carlo-based tsunami simulations are performed using stochastic earthquake slip distributions derived from a spectral synthesis method and probabilistic scaling relationships of earthquake source parameters. By focusing on Sendai (plain coast and Onagawa (ria coast in the Miyagi Prefecture of Japan in a case study, the stochastic tsunami loss is evaluated by total economic loss and its spatial distribution at different scales. The results indicate that tsunami loss prediction is highly sensitive to modelling resolution and inclusion of flow velocity for buildings located less than 1 km from the sea for Sendai and Onagawa of Miyagi Prefecture.

  19. Error estimation for CFD aeroheating prediction under rarefied flow condition

    Science.gov (United States)

    Jiang, Yazhong; Gao, Zhenxun; Jiang, Chongwen; Lee, Chunhian

    2014-12-01

    Both direct simulation Monte Carlo (DSMC) and Computational Fluid Dynamics (CFD) methods have become widely used for aerodynamic prediction when reentry vehicles experience different flow regimes during flight. The implementation of slip boundary conditions in the traditional CFD method under Navier-Stokes-Fourier (NSF) framework can extend the validity of this approach further into transitional regime, with the benefit that much less computational cost is demanded compared to DSMC simulation. Correspondingly, an increasing error arises in aeroheating calculation as the flow becomes more rarefied. To estimate the relative error of heat flux when applying this method for a rarefied flow in transitional regime, theoretical derivation is conducted and a dimensionless parameter ɛ is proposed by approximately analyzing the ratio of the second order term to first order term in the heat flux expression in Burnett equation. DSMC simulation for hypersonic flow over a cylinder in transitional regime is performed to test the performance of parameter ɛ, compared with two other parameters, Knρ and MaṡKnρ.

  20. Load estimation from planar PIV measurement in vortex dominated flows

    Science.gov (United States)

    McClure, Jeffrey; Yarusevych, Serhiy

    2017-11-01

    Control volume-based loading estimates are employed on experimental and synthetic numerical planar Particle Image Velocimetry (PIV) data of a stationary cylinder and a cylinder undergoing one degree-of-freedom (1DOF) Vortex Induced Vibration (VIV). The results reveal the necessity of including out of plane terms, identified from a general formulation of the control volume momentum balance, when evaluating loads from planar measurements in three-dimensional flows. Reynolds stresses from out of plane fluctuations are shown to be significant for both instantaneous and mean force estimates when the control volume encompasses vortex dominated regions. For planar measurement, invoking a divergence-free assumption allows accurate estimation of half the identified terms. Towards evaluating the fidelity of PIV-based loading estimates for obtaining the forcing function unobtrusively in VIV experiments, the accuracy of the control volume-based loading methodology is evaluated using the numerical data with synthetically generated experimental PIV error, and a comparison is made between experimental PIV-based estimates and simultaneous force balance measurements.

  1. stochastic estimation of transmissivity fields conditioned to flow connectivity data

    Science.gov (United States)

    Freixas, Genis; Fernàndez-Garcia, Daniel; Sanchez-vila, Xavier

    2017-04-01

    Most methods for hydraulic parameter interpretation rely on a number of simplifications regarding the homogeneity of the underlying porous media. This way, the actual heterogeneity of any natural parameter, such as transmissivity, is transferred to the estimated in a way heavily dependent on the interpretation method used. An example is a pumping test, in most cases interpreted by means of the Cooper-Jacob method, which implicitly assumes a homogeneous isotropic confined aquifer. It was shown that the estimates obtained from this method when applied to a real site are not local values, but still have a physical meaning; the estimated transmissivity is equal to the effective transmissivity characteristic of the regional scale, while the log-ratio of the estimated storage coefficient with respect to the actual real value (assumed constant), indicated by , is an indicator of flow connectivity, representative of the scale given by the distance between the pumping and the observation wells. In this work we propose a methodology to use together with actual measurements of the log transmissivity at selected points to obtain a map of the best local transmissivity estimates using cokriging. Since the interpolation involves two variables measured at different support scales, a critical point is the estimation of the covariance and crosscovariance matrices, involving some quadratures that are obtained using some simplified approach. The method was applied to a synthetic field displaying statistical anisotropy, showing that the use of connectivity indicators mixed with the local values provide a better representation of the local value map, in particular regarding the enhanced representation of the continuity of structures corresponding to either high or low values.

  2. Systematic donor blood qualification by flow cytometry would have been able to avoid CLL-type MBL transmission after unrelated hematopoietic stem cell transplantation.

    Science.gov (United States)

    Ferrand, Christophe; Garnache-Ottou, Francine; Collonge-Rame, Marie Agnès; Larosa, Fabrice; Blanc, Michel; Behar, Catherine; Giannoli, Catherine; Garnier, Frédérico; Tiberghien, Pierre; Deconinck, Eric; Rohrlich, Pierre Simon

    2012-03-01

    The current screening for eligibility of unrelated volunteer marrow donors comprises a complete clinical check-up, a blood CBC and serum protein immunoelectrophoresis. This allows to eliminate acute leukemias, myeloproliferative and myelodysplastic disorders, myelomas and MGUS. To date, the risk of transmission of chronic lymphocytic leukemia (CLL) disease is only evaluated by the clinical evaluation and CBC. We report here the case of a CLL-type MBL disease occurring in a 12-year-old boy after unrelated BMT. Deep biological investigations, as Immunophenotyping, cytogenetic and molecular biology allow us to determine the donor origin of the CLL clone. In 2010, 14.2% donor (105/737) for unrelated hematopoietic stem cell transplantation were over 45y. It is currently estimated (USA) that 1 in 210 men and women will be diagnosed with CLL during their lifetime. Given the long asymptomatic phase of CLL, this raises the case for a detection strategy analog to that used for MGUS and myeloma through serum protein electrophoresis. This case-report, to our knowledge, of a CLL-type MBL unrelated donor-to-recipient transmission through BMT raises ethical and practical questions, such as the proper information about disease transmission risk. The cost-effectiveness of a systematic peripheral blood Immunophenotyping in donors elder than 40y at time of stem cell donation should be evaluated. © 2012 John Wiley & Sons A/S.

  3. Source Estimation for the Damped Wave Equation Using Modulating Functions Method: Application to the Estimation of the Cerebral Blood Flow

    KAUST Repository

    Asiri, Sharefa M.; Laleg-Kirati, Taous-Meriem

    2017-01-01

    In this paper, a method based on modulating functions is proposed to estimate the Cerebral Blood Flow (CBF). The problem is written in an input estimation problem for a damped wave equation which is used to model the spatiotemporal variations

  4. Cash flows: The Gap Between Reported and Estimated Operating Cash Flow Elements

    Directory of Open Access Journals (Sweden)

    Mark Hughes

    2010-03-01

    Full Text Available The FASB and the IASB recently released a joint Discussion Paper “Preliminary Views on FinancialStatement Presentation” (International Accounting Standards Board 2008, which contains a major proposalrequiring companies to report operating cash flows using the direct method and it also requires that theindirect method of calculating operating cash flows be disclosed in the notes. This is a departure from currentrules and has generated considerable debate among respondents’ comment letters on the Discussion Paper.This paper adds to this debate by providing some evidence as to the size of the gap users confront when usingthe indirect method to estimate the major operating cash flow elements, such as cash collected fromcustomers and cash paid to suppliers. Using a sample of Australian companies which reported operating cashflows using the direct method, and presented the indirect method in the notes, we find significant differencesbetween reported and estimated figures for both cash collected from customers and cash paid to suppliers.These findings support the discussion paper’s proposal that companies be required to report cash flows usingboth the direct and indirect methods.

  5. Estimating preferential flow in karstic aquifers using statistical mixed models.

    Science.gov (United States)

    Anaya, Angel A; Padilla, Ingrid; Macchiavelli, Raul; Vesper, Dorothy J; Meeker, John D; Alshawabkeh, Akram N

    2014-01-01

    Karst aquifers are highly productive groundwater systems often associated with conduit flow. These systems can be highly vulnerable to contamination, resulting in a high potential for contaminant exposure to humans and ecosystems. This work develops statistical models to spatially characterize flow and transport patterns in karstified limestone and determines the effect of aquifer flow rates on these patterns. A laboratory-scale Geo-HydroBed model is used to simulate flow and transport processes in a karstic limestone unit. The model consists of stainless steel tanks containing a karstified limestone block collected from a karst aquifer formation in northern Puerto Rico. Experimental work involves making a series of flow and tracer injections, while monitoring hydraulic and tracer response spatially and temporally. Statistical mixed models (SMMs) are applied to hydraulic data to determine likely pathways of preferential flow in the limestone units. The models indicate a highly heterogeneous system with dominant, flow-dependent preferential flow regions. Results indicate that regions of preferential flow tend to expand at higher groundwater flow rates, suggesting a greater volume of the system being flushed by flowing water at higher rates. Spatial and temporal distribution of tracer concentrations indicates the presence of conduit-like and diffuse flow transport in the system, supporting the notion of both combined transport mechanisms in the limestone unit. The temporal response of tracer concentrations at different locations in the model coincide with, and confirms the preferential flow distribution generated with the SMMs used in the study. © 2013, National Ground Water Association.

  6. Developing a planning model to estimate future cash flows.

    Science.gov (United States)

    Barenbaum, L; Monahan, T F

    1988-03-01

    Financial managers are discovering that net income and other traditional measures of cash flow may not provide them with the flexibility needed for comprehensive internal planning and control. By using a discretionary cash flow model, financial managers have a forecasting tool that can help them measure anticipated cash flows, and make better decisions concerning financing alternatives, capital expansion, and performance appraisal.

  7. Dual states estimation of a subsurface flow-transport coupled model using ensemble Kalman filtering

    KAUST Repository

    El Gharamti, Mohamad; Hoteit, Ibrahim; Valstar, Johan R.

    2013-01-01

    Modeling the spread of subsurface contaminants requires coupling a groundwater flow model with a contaminant transport model. Such coupling may provide accurate estimates of future subsurface hydrologic states if essential flow and contaminant data

  8. A service and value based approach to estimating environmental flows

    DEFF Research Database (Denmark)

    Korsgaard, Louise; Jensen, R.A.; Jønch-Clausen, Torkil

    2008-01-01

    at filling that gap by presenting a new environmental flows assessment approach that explicitly links environmental flows to (socio)-economic values by focusing on ecosystem services. This Service Provision Index (SPI) approach is a novel contribution to the existing field of environmental flows assessment...... of sustaining ecosystems but also a matter of supporting humankind/livelihoods. One reason for the marginalisation of environmental flows is the lack of operational methods to demonstrate the inherently multi-disciplinary link between environmental flows, ecosystem services and economic value. This paper aims...

  9. Methods for estimating flow-duration and annual mean-flow statistics for ungaged streams in Oklahoma

    Science.gov (United States)

    Esralew, Rachel A.; Smith, S. Jerrod

    2010-01-01

    Flow statistics can be used to provide decision makers with surface-water information needed for activities such as water-supply permitting, flow regulation, and other water rights issues. Flow statistics could be needed at any location along a stream. Most often, streamflow statistics are needed at ungaged sites, where no flow data are available to compute the statistics. Methods are presented in this report for estimating flow-duration and annual mean-flow statistics for ungaged streams in Oklahoma. Flow statistics included the (1) annual (period of record), (2) seasonal (summer-autumn and winter-spring), and (3) 12 monthly duration statistics, including the 20th, 50th, 80th, 90th, and 95th percentile flow exceedances, and the annual mean-flow (mean of daily flows for the period of record). Flow statistics were calculated from daily streamflow information collected from 235 streamflow-gaging stations throughout Oklahoma and areas in adjacent states. A drainage-area ratio method is the preferred method for estimating flow statistics at an ungaged location that is on a stream near a gage. The method generally is reliable only if the drainage-area ratio of the two sites is between 0.5 and 1.5. Regression equations that relate flow statistics to drainage-basin characteristics were developed for the purpose of estimating selected flow-duration and annual mean-flow statistics for ungaged streams that are not near gaging stations on the same stream. Regression equations were developed from flow statistics and drainage-basin characteristics for 113 unregulated gaging stations. Separate regression equations were developed by using U.S. Geological Survey streamflow-gaging stations in regions with similar drainage-basin characteristics. These equations can increase the accuracy of regression equations used for estimating flow-duration and annual mean-flow statistics at ungaged stream locations in Oklahoma. Streamflow-gaging stations were grouped by selected drainage

  10. Do analysts disclose cash flow forecasts with earnings estimates when earnings quality is low?

    OpenAIRE

    Bilinski, P.

    2014-01-01

    Cash flows are incrementally useful to earnings in security valuation mainly when earnings quality is low. This suggests that when earnings quality decreases, analysts will be more likely to supplement their earnings forecasts with cash flow estimates. Contrary to this prediction, we find that analysts do not disclose cash flow forecasts when the quality of earnings is low. This is because cash flow forecast accuracy depends on the accuracy of the accrual estimates and the precision of accrua...

  11. Accuracy of GFR estimation formula in determination of glomerular filtration rate in kidney donors: Comparison with 24 h urine creatinine clearance

    Directory of Open Access Journals (Sweden)

    Abdul Rauf Hafeez

    2016-01-01

    Full Text Available To determine the accuracy of estimated glomerular filtration rate (eGFR using the modification of diet in renal disease (MDRD, Cockcroft-Gault (CG, and chronic kidney disease epidemiology (CKD-EPI formulas in potential kidney donors compared with 24-h urine creatinine clearance, we studied 207 potential live kidney donors in our center. There were 126 (60.9% males and 81 (39.1% females. Male:female ratio was 1.6:1. The age of the donors ranged from 18-58 years, with mean age of 35.30 ± 9.23 years and most of the individuals were below 40 years of age. The body mass index (BMI was calculated and venous blood samples were obtained for the measurement of serum creatinine and every study participant was instructed to collect 24-h urine. GFR was calculated based on 24-h urine creatinine clearance and the formulas. The accuracy of GFR estimation formula was taken as positive if the GFR calculated by the formulas and urine creatinine clearance fell between 90-120 mL/min/1.73 m 2 . The accuracy of the MDRD formula was 48.8% and the CG formula was 41.5% whereas the accuracy of the CKD-EPI formula was 78.2%. The accuracy of the eGFR using the MDRD formula was significantly higher in males than females (57.9% vs. 33.3% P = 0.001, while there was no statistically significant difference in the eGFR between them in case of the use of the CG and the CKD-EPI formulas. BMI and obesity had no effect on the accuracy of eGFR by the use of the different formulas. The performance of GFR estimation formulas was sub optimal and these either underestimated and/or over-estimated the GFR in healthy subjects. CKD-EPI is closer to 24 -h urinary creatinine clearance in the calculation of eGFR. However, none of the eGFR formulas can be used in renal transplant donors because of their low accuracy, and 24-h urine creatinine clearance should be used for evaluation of the GFR in this population.

  12. Endothelial shear stress estimation in the human carotid artery based on Womersley versus Poiseuille flow

    NARCIS (Netherlands)

    Schwarz, Janina C. V.; Duivenvoorden, Raphaël; Nederveen, Aart J.; Stroes, Erik S. G.; VanBavel, Ed

    2015-01-01

    Endothelial shear stress (ESS) dynamics are a major determinant of atherosclerosis development. The frequently used Poiseuille method to estimate ESS dynamics has important limitations. Therefore, we investigated whether Womersley flow may provide a better alternative for estimation of ESS while

  13. Estimation of friction loss under forced flow pulsations in a channel with discrete roughness elements

    Science.gov (United States)

    Davletshin, I. A.; Dushina, O. A.; Mikheev, N. I.; Kolchin, S. A.

    2017-11-01

    The pulsating flow in a circular channel with semicircular annular ribs as discrete roughness elements has been studied experimentally. Air flow under atmospheric conditions at the channel inlet has been considered. Steady and pulsating air flow has been studied under different frequencies and amplitudes of forced pulsations generated by periodic blockage of the channel cross section by a rotating flap. Flow resistance in pulsating regimes has been estimated from the average static pressure drop. The resistance values attained twice the steady flow ones.

  14. Estimation of Flow Channel Parameters for Flowing Gas Mixed with Air in Atmospheric-pressure Plasma Jets

    Science.gov (United States)

    Yambe, Kiyoyuki; Saito, Hidetoshi

    2017-12-01

    When the working gas of an atmospheric-pressure non-equilibrium (cold) plasma flows into free space, the diameter of the resulting flow channel changes continuously. The shape of the channel is observed through the light emitted by the working gas of the atmospheric-pressure plasma. When the plasma jet forms a conical shape, the diameter of the cylindrical shape, which approximates the conical shape, defines the diameter of the flow channel. When the working gas flows into the atmosphere from the inside of a quartz tube, the gas mixes with air. The molar ratio of the working gas and air is estimated from the corresponding volume ratio through the relationship between the diameter of the cylindrical plasma channel and the inner diameter of the quartz tube. The Reynolds number is calculated from the kinematic viscosity of the mixed gas and the molar ratio. The gas flow rates for the upper limit of laminar flow and the lower limit of turbulent flow are determined by the corresponding Reynolds numbers estimated from the molar ratio. It is confirmed that the plasma jet length and the internal plasma length associated with strong light emission increase with the increasing gas flow rate until the rate for the upper limit of laminar flow and the lower limit of turbulent flow, respectively. Thus, we are able to explain the increasing trend in the plasma lengths with the diameter of the flow channel and the molar ratio by using the cylindrical approximation.

  15. Improved flow velocity estimates from moving-boat ADCP measurements

    NARCIS (Netherlands)

    Vermeulen, B.; Hoitink, A.J.F.; Sassi, M.G.

    2014-01-01

    Acoustic Doppler current profilers (ADCPs) are the current standard for flow measurements in large-scale open water systems. Existing techniques to process vessel-mounted ADCP data assume homogeneous or linearly changing flow between the acoustic beams. This assumption is likely to fail but is

  16. Estimation of preferred water flow parameters for four species of ...

    African Journals Online (AJOL)

    Blackfly larvae typically occur in fast-flowing riffle sections of rivers, with different blackfly species showing preferences for different hydraulic conditions. Very little quantitative data exist on hydraulic conditions linked to the blackfly species occurring in South African streams. Stones-in-current biotopes (i.e. fast riffle flows over ...

  17. Estimating daily flow duration curves from monthly streamflow data

    CSIR Research Space (South Africa)

    Smakhtin, VU

    2000-01-01

    Full Text Available The paper describes two techniques by which to establish 1-day (1d) flow duration curves at an ungauged site where only a simulated or calculated monthly flow time series is available. Both methods employ the straightforward relationships between...

  18. Optic Flow Based State Estimation for an Indoor Micro Air Vehicle

    NARCIS (Netherlands)

    Verveld, M.J.; Chu, Q.P.; De Wagter, C.; Mulder, J.A.

    2010-01-01

    This work addresses the problem of indoor state estimation for autonomous flying vehicles with an optic flow approach. The paper discusses a sensor configuration using six optic flow sensors of the computer mouse type augmented by a three-axis accelerometer to estimate velocity, rotation, attitude

  19. Local scattering property scales flow speed estimation in laser speckle contrast imaging

    International Nuclear Information System (INIS)

    Miao, Peng; Chao, Zhen; Feng, Shihan; Ji, Yuanyuan; Yu, Hang; Thakor, Nitish V; Li, Nan

    2015-01-01

    Laser speckle contrast imaging (LSCI) has been widely used in in vivo blood flow imaging. However, the effect of local scattering property (scattering coefficient µ s ) on blood flow speed estimation has not been well investigated. In this study, such an effect was quantified and involved in relation between speckle autocorrelation time τ c and flow speed v based on simulation flow experiments. For in vivo blood flow imaging, an improved estimation strategy was developed to eliminate the estimation bias due to the inhomogeneous distribution of the scattering property. Compared to traditional LSCI, a new estimation method significantly suppressed the imaging noise and improves the imaging contrast of vasculatures. Furthermore, the new method successfully captured the blood flow changes and vascular constriction patterns in rats’ cerebral cortex from normothermia to mild and moderate hypothermia. (letter)

  20. A simple estimation of the renal plasma flow

    International Nuclear Information System (INIS)

    Shinpo, Takako

    1987-01-01

    The renal plasma flow was determined conventionally by the excretive ratio to urine using a 131 I-Hippuran renogram. In this report, we proposed the renal clearance, the product of the disappearance rate coefficient and the maximum counts of the bladder, for the simple quantitative value of renal plasma flow. The disappearance rate coefficient was calculated by approximating the exponential function of the initial slope from the disappearance curve of the heart. The renal clearances was compared with the renal plasma flow calculated by the conventional method. The results gave a high correlation coefficient of r = 0.91. The renal clearances can be calculated easily and it offers useful renogram information. (author)

  1. Transverse correlation: An efficient transverse flow estimator - initial results

    DEFF Research Database (Denmark)

    Holfort, Iben Kraglund; Henze, Lasse; Kortbek, Jacob

    2008-01-01

    , a standard deviation of 1.64% and a bias of 1.13% are obtained for a beam to flow angle of 90 degrees. Using the same setup a standard deviation of 2.21% and a bias of 1.07% are obtained for a beam to flow angle of 75 degrees. Using 20 emissions a standard deviation of 3.4% and a bias of 2.06% are obtained...... at 45 degrees. The method performs stable down to a signal-to-noise ratio of 0 dB, where a standard deviation of 5.5% and a bias of 1.2% is achieved....

  2. Vector velocity volume flow estimation: Sources of error and corrections applied for arteriovenous fistulas

    DEFF Research Database (Denmark)

    Jensen, Jonas; Olesen, Jacob Bjerring; Stuart, Matthias Bo

    2016-01-01

    radius. The error sources were also studied in vivo under realistic clinical conditions, and the theoretical results were applied for correcting the volume flow errors. Twenty dialysis patients with arteriovenous fistulas were scanned to obtain vector flow maps of fistulas. When fitting an ellipsis......A method for vector velocity volume flow estimation is presented, along with an investigation of its sources of error and correction of actual volume flow measurements. Volume flow errors are quantified theoretically by numerical modeling, through flow phantom measurements, and studied in vivo...

  3. Development of flow injection analysis technique for uranium estimation

    International Nuclear Information System (INIS)

    Paranjape, A.H.; Pandit, S.S.; Shinde, S.S.; Ramanujam, A.; Dhumwad, R.K.

    1991-01-01

    Flow injection analysis is increasingly used as a process control analytical technique in many industries. It involves injection of the sample at a constant rate into a steady flowing stream of reagent and passing this mixture through a suitable detector. This paper describes the development of such a system for the analysis of uranium (VI) and (IV) and its gross gamma activity. It is amenable for on-line or automated off-line monitoring of uranium and its activity in process streams. The sample injection port is suitable for automated injection of radioactive samples. The performance of the system has been tested for the colorimetric response of U(VI) samples at 410 nm in the range of 35 to 360mg/ml in nitric acid medium using Metrohm 662 Photometer and a recorder as detector assembly. The precision of the method is found to be better than +/- 0.5%. This technique with certain modifications is used for the analysis of U(VI) in the range 0.1-3mg/ailq. by alcoholic thiocynate procedure within +/- 1.5% precision. Similarly the precision for the determination of U(IV) in the range 15-120 mg at 650 nm is found to be better than 5%. With NaI well-type detector in the flow line, the gross gamma counting of the solution under flow is found to be within a precision of +/- 5%. (author). 4 refs., 2 figs., 1 tab

  4. Remotely Sensed, catchment scale, estimations of flow resistance

    Science.gov (United States)

    Carbonneau, P.; Dugdale, S. J.

    2009-12-01

    Despite a decade of progress in the field of fluvial remote sensing, there are few published works using this new technology to advance and explore fundamental ideas and theories in fluvial geomorphology. This paper will apply remote sensing methods in order to re-visit a classic concept in fluvial geomorphology: flow resistance. Classic flow resistance equations such as those of Strickler and Keulegan typically use channel slope, channel depth or hydraulic radius and some measure channel roughness usually equated to the 50th or 84th percentile of the bed material size distribution. In this classic literature, empirical equations such as power laws are usually calibrated and validated with a maximum of a few hundred data points. In contrast, fluvial remote sensing methods are now capable of delivering millions of high resolution data points in continuous, catchment scale, surveys. On the river Tromie in Scotland, a full dataset or river characteristics is now available. Based on low altitude imagery and NextMap topographic data, this dataset has a continuous sampling of channel width at a resolution of 3cm, of depth and median grain size at a resolution of 1m, and of slope at a resolution of 5m. This entire data set is systematic and continuous for the entire 20km length of the river. When combined with discharge at the time of data acquisition, this new dataset offers the opportunity to re-examine flow resistance equations with a 2-4 orders of magnitude increase in calibration data. This paper will therefore re-examine the classic approaches of Strickler and Keulagan along with other more recent flow resistance equations. Ultimately, accurate predictions of flow resistance from remotely sensed parameters could lead to acceptable predictions of velocity. Such a usage of classic equations to predict velocity could allow lotic habitat models to account for microhabitat velocity at catchment scales without the recourse to advanced and computationally intensive

  5. Estimation of inhalation flow profile using audio-based methods to assess inhaler medication adherence

    Science.gov (United States)

    Lacalle Muls, Helena; Costello, Richard W.; Reilly, Richard B.

    2018-01-01

    Asthma and chronic obstructive pulmonary disease (COPD) patients are required to inhale forcefully and deeply to receive medication when using a dry powder inhaler (DPI). There is a clinical need to objectively monitor the inhalation flow profile of DPIs in order to remotely monitor patient inhalation technique. Audio-based methods have been previously employed to accurately estimate flow parameters such as the peak inspiratory flow rate of inhalations, however, these methods required multiple calibration inhalation audio recordings. In this study, an audio-based method is presented that accurately estimates inhalation flow profile using only one calibration inhalation audio recording. Twenty healthy participants were asked to perform 15 inhalations through a placebo Ellipta™ DPI at a range of inspiratory flow rates. Inhalation flow signals were recorded using a pneumotachograph spirometer while inhalation audio signals were recorded simultaneously using the Inhaler Compliance Assessment device attached to the inhaler. The acoustic (amplitude) envelope was estimated from each inhalation audio signal. Using only one recording, linear and power law regression models were employed to determine which model best described the relationship between the inhalation acoustic envelope and flow signal. Each model was then employed to estimate the flow signals of the remaining 14 inhalation audio recordings. This process repeated until each of the 15 recordings were employed to calibrate single models while testing on the remaining 14 recordings. It was observed that power law models generated the highest average flow estimation accuracy across all participants (90.89±0.9% for power law models and 76.63±2.38% for linear models). The method also generated sufficient accuracy in estimating inhalation parameters such as peak inspiratory flow rate and inspiratory capacity within the presence of noise. Estimating inhaler inhalation flow profiles using audio based methods may be

  6. Estimation of roughness lengths and flow separation over compound bedforms in a natural-tidal inlet

    DEFF Research Database (Denmark)

    Lefebvre, Alice; Ernstsen, Verner Brandbyge; Winter, Christian

    2013-01-01

    was found to underestimate the length of the flow separation zone of the primary bedforms. A better estimation of the presence and shape of the flow separation zone over complex bedforms in a tidal environment still needs to be determined; in particular the relationship between flow separation zone......The hydraulic effect of asymmetric compound bedforms on tidal currents was assessed from field measurements of flow velocity in the Knudedyb tidal inlet, Denmark. Large asymmetric bedforms with smaller superimposed ones are a common feature of sandy shallow water environments and are known to act...... as hydraulic roughness elements in dependence with flow direction. The presence of a flow separation zone on the bedform lee was estimated through analysis of the measured velocity directions and the calculation of the flow separation line. The Law of the Wall was used to calculate roughness lengths and shear...

  7. A service and value based approach to estimating environmental flows

    DEFF Research Database (Denmark)

    Korsgaard, Louise; Jensen, R.A.; Jønch-Clausen, Torkil

    2008-01-01

    An important challenge of Integrated Water Resources Management (IWRM) is to balance water allocation between different users and uses. While economically and/or politically powerful users have relatively well developed methods for quantifying and justifying their water needs, this is not the case...... methodologies. The SPI approach is a pragmatic and transparent tool for incorporating ecosystems and environmental flows into the evaluation of water allocation scenarios, negotiations of trade-offs and decision-making in IWRM....

  8. 3-D Vector Flow Estimation With Row-Column-Addressed Arrays.

    Science.gov (United States)

    Holbek, Simon; Christiansen, Thomas Lehrmann; Stuart, Matthias Bo; Beers, Christopher; Thomsen, Erik Vilain; Jensen, Jorgen Arendt

    2016-11-01

    Simulation and experimental results from 3-D vector flow estimations for a 62 + 62 2-D row-column (RC) array with integrated apodization are presented. A method for implementing a 3-D transverse oscillation (TO) velocity estimator on a 3-MHz RC array is developed and validated. First, a parametric simulation study is conducted, where flow direction, ensemble length, number of pulse cycles, steering angles, transmit/receive apodization, and TO apodization profiles and spacing are varied, to find the optimal parameter configuration. The performance of the estimator is evaluated with respect to relative mean bias ~B and mean standard deviation ~σ . Second, the optimal parameter configuration is implemented on the prototype RC probe connected to the experimental ultrasound scanner SARUS. Results from measurements conducted in a flow-rig system containing a constant laminar flow and a straight-vessel phantom with a pulsating flow are presented. Both an M-mode and a steered transmit sequence are applied. The 3-D vector flow is estimated in the flow rig for four representative flow directions. In the setup with 90° beam-to-flow angle, the relative mean bias across the entire velocity profile is (-4.7, -0.9, 0.4)% with a relative standard deviation of (8.7, 5.1, 0.8)% for ( v x , v y , v z ). The estimated peak velocity is 48.5 ± 3 cm/s giving a -3% bias. The out-of-plane velocity component perpendicular to the cross section is used to estimate volumetric flow rates in the flow rig at a 90° beam-to-flow angle. The estimated mean flow rate in this setup is 91.2 ± 3.1 L/h corresponding to a bias of -11.1%. In a pulsating flow setup, flow rate measured during five cycles is 2.3 ± 0.1 mL/stroke giving a negative 9.7% bias. It is concluded that accurate 3-D vector flow estimation can be obtained using a 2-D RC-addressed array.

  9. Estimation of local and regional components of drain - flow from an irrigated field

    International Nuclear Information System (INIS)

    Eching, S.O.; Hopmans, J.W.; Wallender, W.W.; Macyntyre, J.L.; Peters, D.

    1995-01-01

    The contribution of regional ground water and deep percolation from a furrow irrigated field to total drain flow was estimated using salt load analysis. It was found that 64% of the drain flow comes from regional ground water flow. The electrical conductivity of the drain water was highly correlated with the drain flow rate. From the field water balance with deep percolation as estimated from the salt load analysis, using yield function derived evapotranspiration, and measured changes in root zone water storage, it was shown that 14% of the crop evapotranspiration comes from ground water during the study period. 8 figs; 5 tabs; 15 refs ( Author )

  10. Modeling, Identification, Estimation, and Simulation of Urban Traffic Flow in Jakarta and Bandung

    Directory of Open Access Journals (Sweden)

    Herman Y. Sutarto

    2015-06-01

    Full Text Available This paper presents an overview of urban traffic flow from the perspective of system theory and stochastic control. The topics of modeling, identification, estimation and simulation techniques are evaluated and validated using actual traffic flow data from the city of Jakarta and Bandung, Indonesia, and synthetic data generated from traffic micro-simulator VISSIM. The results on particle filter (PF based state estimation and Expectation-Maximization (EM based parameter estimation (identification confirm the proposed model gives satisfactory results that capture the variation of urban traffic flow. The combination of the technique and the simulator platform assembles possibility to develop a real-time traffic light controller.  

  11. Comparison of lactate, formate, and propionate as hydrogen donors for the reductive dehalogenation of trichloroethene in a continuous-flow column

    Science.gov (United States)

    Azizian, Mohammad F.; Marshall, Ian P. G.; Behrens, Sebastian; Spormann, Alfred M.; Semprini, Lewis

    2010-04-01

    A continuous-flow column study was conducted to analyze the reductive dehalogenation of trichloroethene (TCE) with aquifer material with high content of iron oxides. The column was bioaugmented with the Point Mugu (PM) culture, which is a mixed microbial enrichment culture capable of completely transforming TCE to ethene (ETH). We determined whether lactate, formate, or propionate fermentation resulted in more effective dehalogenation. Reductive dehalogenation, fermentation, and sulfate, Fe(III), and Mn(IV) reduction were all exhibited within the column. Different steady-states of dehalogenation were achieved based on the concentration of substrates added, with effective transformation to ETH obtained when ample electron donor equivalents were provided. Most of the metabolic reducing equivalents were channeled to sulfate, Fe(III), and Mn(IV) reduction. When similar electron reducing equivalents were added, the most effective dehalogenation was achieved with formate, with 14% of the electron equivalents going towards dehalogenation reactions, compared to 6.5% for lactate and 9.6% for propionate. Effective dehalogenation was maintained over 1000 days of column operation. Over 90% of electron equivalents added could be accounted for by the different electron accepting processes in the column, with 50% associated with soluble and precipitated Fe(II) and Mn(II). Bulk Fe(III) and Mn(IV) reduction was rather associated with lactate and propionate addition than formate addition. Sulfate reduction was a competing electron acceptor reaction with all three electron donors. DNA was extracted from solid coupon samples obtained during the course of the experiment and analyzed using 16S rRNA gene clone libraries and quantitative PCR. Lactate and propionate addition resulted in a significant increase in Geobacter, Spirochaetes, and Desulfitobacterium phylotypes relative to " Dehalococcoides" when compared to formate addition. Results from the molecular biological analyses support

  12. Source Estimation for the Damped Wave Equation Using Modulating Functions Method: Application to the Estimation of the Cerebral Blood Flow

    KAUST Repository

    Asiri, Sharefa M.

    2017-10-19

    In this paper, a method based on modulating functions is proposed to estimate the Cerebral Blood Flow (CBF). The problem is written in an input estimation problem for a damped wave equation which is used to model the spatiotemporal variations of blood mass density. The method is described and its performance is assessed through some numerical simulations. The robustness of the method in presence of noise is also studied.

  13. Thermal particle image velocity estimation of fire plume flow

    Science.gov (United States)

    Xiangyang Zhou; Lulu Sun; Shankar Mahalingam; David R. Weise

    2003-01-01

    For the purpose of studying wildfire spread in living vegetation such as chaparral in California, a thermal particle image velocity (TPIV) algorithm for nonintrusively measuring flame gas velocities through thermal infrared (IR) imagery was developed. By tracing thermal particles in successive digital IR images, the TPIV algorithm can estimate the velocity field in a...

  14. Risk and size estimation of debris flow caused by storm rainfall in mountain regions

    Institute of Scientific and Technical Information of China (English)

    CHENG; Genwei

    2003-01-01

    Debris flow is a common disaster in mountain regions. The valley slope, storm rainfall and amassed sand-rock materials in a watershed may influence the types of debris flow. The bursting of debris flow is not a pure random event. Field investigations show the periodicity of its burst, but no directive evidence has been found yet. A risk definition of debris flow is proposed here based upon the accumulation and the starting conditions of loose material in channel. According to this definition, the risk of debris flow is of quasi-periodicity. A formula of risk estimation is derived. Analysis of relative factors reveals the relationship between frequency and size of debris flow. For a debris flow creek, the longer the time interval between two occurrences of debris flows is, the bigger the bursting event will be.

  15. Use of a Phase Transition Concept for Traffic Flow Condition Estimation

    Directory of Open Access Journals (Sweden)

    Larin Oleg N.

    2014-12-01

    Full Text Available The article covers the main models of traffic flow conditions, analyzes the condition estimation criteria, and provides the classification of models. The article provides the grounds for the use of the phase transition concept for traffic flow condition estimation. The models of the aggregate condition of free and congested traffic have been developed, the phase boundaries between free and congested traffic have been defined. Applicability conditions for the models of the aggregate condition of have been analyzed.

  16. Toward an enhanced Bayesian estimation framework for multiphase flow soft-sensing

    International Nuclear Information System (INIS)

    Luo, Xiaodong; Lorentzen, Rolf J; Stordal, Andreas S; Nævdal, Geir

    2014-01-01

    In this work the authors study the multiphase flow soft-sensing problem based on a previously established framework. There are three functional modules in this framework, namely, a transient well flow model that describes the response of certain physical variables in a well, for instance, temperature, velocity and pressure, to the flow rates entering and leaving the well zones; a Markov jump process that is designed to capture the potential abrupt changes in the flow rates; and an estimation method that is adopted to estimate the underlying flow rates based on the measurements from the physical sensors installed in the well. In the previous studies, the variances of the flow rates in the Markov jump process are chosen manually. To fill this gap, in the current work two automatic approaches are proposed in order to optimize the variance estimation. Through a numerical example, we show that, when the estimation framework is used in conjunction with these two proposed variance-estimation approaches, it can achieve reasonable performance in terms of matching both the measurements of the physical sensors and the true underlying flow rates. (paper)

  17. Association of HeartMate II left ventricular assist device flow estimate with thermodilution cardiac output.

    Science.gov (United States)

    Hasin, Tal; Huebner, Marianne; Li, Zhuo; Brown, Daniel; Stulak, John M; Boilson, Barry A; Joyce, Lyle; Pereira, Naveen L; Kushwaha, Sudhir S; Park, Soon J

    2014-01-01

    Cardiac output (CO) assessment is important in treating patients with heart failure. Durable left ventricular assist devices (LVADs) provide essentially all CO. In currently used LVADs, estimated device flow is generated by a computerized algorithm. However, LVAD flow estimate may be inaccurate in tracking true CO. We correlated LVAD (HeartMate II) flow with thermodilution CO during postoperative care (day 2-10 after implant) in 81 patients (5,616 paired measurements). Left ventricular assist device flow and CO correlated with a low correlation coefficient (r = 0.42). Left ventricular assist device readings were lower than CO measurements by approximately 0.36 L/min, trending for larger difference with higher values. Left ventricular assist device flow measurements showed less temporal variability compared with CO. Grouping for simultaneous measured blood pressure (BP device flow generally trends with measured CO, but large variability exists, hence flow measures should not be assumed to equal with CO. Clinicians should take into account variables such as high CO, BP, and opening of the aortic valve when interpreting LVAD flow readout. Direct flow sensors incorporated in the LVAD system may allow for better estimation.

  18. Estimating drain flow from measured water table depth in layered soils under free and controlled drainage

    Science.gov (United States)

    Saadat, Samaneh; Bowling, Laura; Frankenberger, Jane; Kladivko, Eileen

    2018-01-01

    Long records of continuous drain flow are important for quantifying annual and seasonal changes in the subsurface drainage flow from drained agricultural land. Missing data due to equipment malfunction and other challenges have limited conclusions that can be made about annual flow and thus nutrient loads from field studies, including assessments of the effect of controlled drainage. Water table depth data may be available during gaps in flow data, providing a basis for filling missing drain flow data; therefore, the overall goal of this study was to examine the potential to estimate drain flow using water table observations. The objectives were to evaluate how the shape of the relationship between drain flow and water table height above drain varies depending on the soil hydraulic conductivity profile, to quantify how well the Hooghoudt equation represented the water table-drain flow relationship in five years of measured data at the Davis Purdue Agricultural Center (DPAC), and to determine the impact of controlled drainage on drain flow using the filled dataset. The shape of the drain flow-water table height relationship was found to depend on the selected hydraulic conductivity profile. Estimated drain flow using the Hooghoudt equation with measured water table height for both free draining and controlled periods compared well to observed flow with Nash-Sutcliffe Efficiency values above 0.7 and 0.8 for calibration and validation periods, respectively. Using this method, together with linear regression for the remaining gaps, a long-term drain flow record for a controlled drainage experiment at the DPAC was used to evaluate the impacts of controlled drainage on drain flow. In the controlled drainage sites, annual flow was 14-49% lower than free drainage.

  19. Simulating nailfold capillaroscopy sequences to evaluate algorithms for blood flow estimation.

    Science.gov (United States)

    Tresadern, P A; Berks, M; Murray, A K; Dinsdale, G; Taylor, C J; Herrick, A L

    2013-01-01

    The effects of systemic sclerosis (SSc)--a disease of the connective tissue causing blood flow problems that can require amputation of the fingers--can be observed indirectly by imaging the capillaries at the nailfold, though taking quantitative measures such as blood flow to diagnose the disease and monitor its progression is not easy. Optical flow algorithms may be applied, though without ground truth (i.e. known blood flow) it is hard to evaluate their accuracy. We propose an image model that generates realistic capillaroscopy videos with known flow, and use this model to quantify the effect of flow rate, cell density and contrast (among others) on estimated flow. This resource will help researchers to design systems that are robust under real-world conditions.

  20. Analysis of methods to estimate spring flows in a karst aquifer.

    Science.gov (United States)

    Sepúlveda, Nicasio

    2009-01-01

    Hydraulically and statistically based methods were analyzed to identify the most reliable method to predict spring flows in a karst aquifer. Measured water levels at nearby observation wells, measured spring pool altitudes, and the distance between observation wells and the spring pool were the parameters used to match measured spring flows. Measured spring flows at six Upper Floridan aquifer springs in central Florida were used to assess the reliability of these methods to predict spring flows. Hydraulically based methods involved the application of the Theis, Hantush-Jacob, and Darcy-Weisbach equations, whereas the statistically based methods were the multiple linear regressions and the technology of artificial neural networks (ANNs). Root mean square errors between measured and predicted spring flows using the Darcy-Weisbach method ranged between 5% and 15% of the measured flows, lower than the 7% to 27% range for the Theis or Hantush-Jacob methods. Flows at all springs were estimated to be turbulent based on the Reynolds number derived from the Darcy-Weisbach equation for conduit flow. The multiple linear regression and the Darcy-Weisbach methods had similar spring flow prediction capabilities. The ANNs provided the lowest residuals between measured and predicted spring flows, ranging from 1.6% to 5.3% of the measured flows. The model prediction efficiency criteria also indicated that the ANNs were the most accurate method predicting spring flows in a karst aquifer.

  1. Directional velocity estimation using focusing along the flow direction - I: Theory and simulation

    DEFF Research Database (Denmark)

    Jensen, Jørgen Arendt

    2003-01-01

    A new method for directional velocity estimation is presented. The method uses beamformation along the flow direction to generate data in which the correct velocity magnitude can be directly estimated from the shift in position of the received consecutive signals. The shift is found by cross-corr...

  2. Accurate Angle Estimator for High-Frame-rate 2-D Vector Flow Imaging

    DEFF Research Database (Denmark)

    Villagómez Hoyos, Carlos Armando; Stuart, Matthias Bo; Lindskov Hansen, Kristoffer

    2016-01-01

    This paper presents a novel approach for estimating 2-D flow angles using a high-frame-rate ultrasound method. The angle estimator features high accuracy and low standard deviation (SD) over the full 360° range. The method is validated on Field II simulations and phantom measurements using...

  3. Effect of region assignment on relative renal blood flow estimates using radionuclides

    International Nuclear Information System (INIS)

    Harris, C.C.; Ford, K.K.; Coleman, R.E.; Dunnick, N.R.

    1984-01-01

    To determine the value of the initial phase of the Tc-99m DTPA renogram in the direct estimation of relative renal blood flow in dogs, the ratios of the slopes of renal time-activity curves were compared with the ratios of measured blood flow. Radionuclide results were dependent on region-of-interest (ROI) and background ROI assignment, and correlated well with measured relative flow only with a maximum renal outline region. Curve slope ratios correlated well with measured flow ratios with and without background correction, while 1- to 2-minute uptake ratios correlated well only when corrected for background

  4. Energy flow models for the estimation of technical losses in distribution network

    International Nuclear Information System (INIS)

    Au, Mau Teng; Tan, Chin Hooi

    2013-01-01

    This paper presents energy flow models developed to estimate technical losses in distribution network. Energy flow models applied in this paper is based on input energy and peak demand of distribution network, feeder length and peak demand, transformer loading capacity, and load factor. Two case studies, an urban distribution network and a rural distribution network are used to illustrate application of the energy flow models. Results on technical losses obtained for the two distribution networks are consistent and comparable to network of similar types and characteristics. Hence, the energy flow models are suitable for practical application.

  5. Real-Time Aerodynamic Parameter Estimation without Air Flow Angle Measurements

    Science.gov (United States)

    Morelli, Eugene A.

    2010-01-01

    A technique for estimating aerodynamic parameters in real time from flight data without air flow angle measurements is described and demonstrated. The method is applied to simulated F-16 data, and to flight data from a subscale jet transport aircraft. Modeling results obtained with the new approach using flight data without air flow angle measurements were compared to modeling results computed conventionally using flight data that included air flow angle measurements. Comparisons demonstrated that the new technique can provide accurate aerodynamic modeling results without air flow angle measurements, which are often difficult and expensive to obtain. Implications for efficient flight testing and flight safety are discussed.

  6. Accuracy and Sources of Error for an Angle Independent Volume Flow Estimator

    DEFF Research Database (Denmark)

    Jensen, Jonas; Olesen, Jacob Bjerring; Hansen, Peter Møller

    2014-01-01

    This paper investigates sources of error for a vector velocity volume flow estimator. Quantification of the estima tor’s accuracy is performed theoretically and investigated in vivo . Womersley’s model for pulsatile flow is used to simulate velo city profiles and calculate volume flow errors....... A BK Medical UltraView 800 ultrasound scanner with a 9 MHz linear array transducer is used to obtain Vector Flow Imaging sequences of a superficial part of the fistulas. Cross-sectional diameters of each fistu la are measured on B-mode images by rotating the scan plane 90 degrees. The major axis...

  7. Modeling of hyaluronan clearance with application to estimation of lymph flow

    International Nuclear Information System (INIS)

    Rössler, Andreas; Goswami, Nandu; Fink, Martin; Batzel, Jerry J

    2011-01-01

    One of the important factors in blood pressure regulation is the maintenance of the level of blood volume, which depends on several factors including the rate of lymph flow. Lymph flow can be measured directly using cannulation of lymphatic vessels, which is not clinically feasible, or indirectly by the tracer appearance rate, which is the rate at which macromolecules appear into the blood from the peritoneal cavity. However, indirect lymph flow measurements do not always provide consistent results. Through its contribution to osmotic pressure and resistance to flow, the macromolecule hyaluronan takes part in the regulation of tissue hydration and the maintenance of water and protein homeostasis. It arrives in blood plasma through lymph flow. Lymphatic hyaluronic acid (HA, hyaluronan) concentration is several times higher than that in plasma, suggesting that the lymphatic route may account for the majority of HA found in plasma. Furthermore, circulating levels of HA reflect the dynamic state between delivery to—and removal from—the bloodstream. To develop an accurate estimation of the fluid volume distribution and dynamics, the rate of lymph flow needs to be taken into account and hyaluronan could be used as a marker in estimating this flow. To examine the HA distribution and system fluid dynamics, a six-compartment model, which could reflect both the steady-state relationships and qualitative characteristics of the dynamics, was developed. This was then applied to estimate fluid shifts from the interstitial space via the lymphatic system to the plasma during different physiological stresses (orthostatic stress and the stress of ultrafiltration during dialysis). Sensitivity analysis shows that during ultrafiltration, lymph flow is a key parameter influencing the total HA level, thus suggesting that the model may find applications in addressing the problem of estimating lymph flow. Since the fluid balance between interstitium and plasma is maintained by lymph

  8. Dual states estimation of a subsurface flow-transport coupled model using ensemble Kalman filtering

    KAUST Repository

    El Gharamti, Mohamad

    2013-10-01

    Modeling the spread of subsurface contaminants requires coupling a groundwater flow model with a contaminant transport model. Such coupling may provide accurate estimates of future subsurface hydrologic states if essential flow and contaminant data are assimilated in the model. Assuming perfect flow, an ensemble Kalman filter (EnKF) can be used for direct data assimilation into the transport model. This is, however, a crude assumption as flow models can be subject to many sources of uncertainty. If the flow is not accurately simulated, contaminant predictions will likely be inaccurate even after successive Kalman updates of the contaminant model with the data. The problem is better handled when both flow and contaminant states are concurrently estimated using the traditional joint state augmentation approach. In this paper, we introduce a dual estimation strategy for data assimilation into a one-way coupled system by treating the flow and the contaminant models separately while intertwining a pair of distinct EnKFs, one for each model. The presented strategy only deals with the estimation of state variables but it can also be used for state and parameter estimation problems. This EnKF-based dual state-state estimation procedure presents a number of novel features: (i) it allows for simultaneous estimation of both flow and contaminant states in parallel; (ii) it provides a time consistent sequential updating scheme between the two models (first flow, then transport); (iii) it simplifies the implementation of the filtering system; and (iv) it yields more stable and accurate solutions than does the standard joint approach. We conducted synthetic numerical experiments based on various time stepping and observation strategies to evaluate the dual EnKF approach and compare its performance with the joint state augmentation approach. Experimental results show that on average, the dual strategy could reduce the estimation error of the coupled states by 15% compared with the

  9. Leading-Edge Flow Sensing for Aerodynamic Parameter Estimation

    Science.gov (United States)

    Saini, Aditya

    The identification of inflow air data quantities such as airspeed, angle of attack, and local lift coefficient on various sections of a wing or rotor blade provides the capability for load monitoring, aerodynamic diagnostics, and control on devices ranging from air vehicles to wind turbines. Real-time measurement of aerodynamic parameters during flight provides the ability to enhance aircraft operating capabilities while preventing dangerous stall situations. This thesis presents a novel Leading-Edge Flow Sensing (LEFS) algorithm for the determination of the air -data parameters using discrete surface pressures measured at a few ports in the vicinity of the leading edge of a wing or blade section. The approach approximates the leading-edge region of the airfoil as a parabola and uses pressure distribution from the exact potential-ow solution for the parabola to _t the pressures measured from the ports. Pressures sensed at five discrete locations near the leading edge of an airfoil are given as input to the algorithm to solve the model using a simple nonlinear regression. The algorithm directly computes the inflow velocity, the stagnation-point location, section angle of attack and lift coefficient. The performance of the algorithm is assessed using computational and experimental data in the literature for airfoils under different ow conditions. The results show good correlation between the actual and predicted aerodynamic quantities within the pre-stall regime, even for a rotating blade section. Sensing the deviation of the aerodynamic behavior from the linear regime requires additional information on the location of ow separation on the airfoil surface. Bio-inspired artificial hair sensors were explored as a part of the current research for stall detection. The response of such artificial micro-structures can identify critical ow characteristics, which relate directly to the stall behavior. The response of the microfences was recorded via an optical microscope for

  10. Estimating Jupiter’s Gravity Field Using Juno Measurements, Trajectory Estimation Analysis, and a Flow Model Optimization

    International Nuclear Information System (INIS)

    Galanti, Eli; Kaspi, Yohai; Durante, Daniele; Finocchiaro, Stefano; Iess, Luciano

    2017-01-01

    The upcoming Juno spacecraft measurements have the potential of improving our knowledge of Jupiter’s gravity field. The analysis of the Juno Doppler data will provide a very accurate reconstruction of spatial gravity variations, but these measurements will be very accurate only over a limited latitudinal range. In order to deduce the full gravity field of Jupiter, additional information needs to be incorporated into the analysis, especially regarding the Jovian flow structure and its depth, which can influence the measured gravity field. In this study we propose a new iterative method for the estimation of the Jupiter gravity field, using a simulated Juno trajectory, a trajectory estimation model, and an adjoint-based inverse model for the flow dynamics. We test this method both for zonal harmonics only and with a full gravity field including tesseral harmonics. The results show that this method can fit some of the gravitational harmonics better to the “measured” harmonics, mainly because of the added information from the dynamical model, which includes the flow structure. Thus, it is suggested that the method presented here has the potential of improving the accuracy of the expected gravity harmonics estimated from the Juno and Cassini radio science experiments.

  11. Estimating Jupiter’s Gravity Field Using Juno Measurements, Trajectory Estimation Analysis, and a Flow Model Optimization

    Energy Technology Data Exchange (ETDEWEB)

    Galanti, Eli; Kaspi, Yohai [Department of Earth and Planetary Sciences, Weizmann Institute of Science, Rehovot (Israel); Durante, Daniele; Finocchiaro, Stefano; Iess, Luciano, E-mail: eli.galanti@weizmann.ac.il [Dipartimento di Ingegneria Meccanica e Aerospaziale, Sapienza Universita di Roma, Rome (Italy)

    2017-07-01

    The upcoming Juno spacecraft measurements have the potential of improving our knowledge of Jupiter’s gravity field. The analysis of the Juno Doppler data will provide a very accurate reconstruction of spatial gravity variations, but these measurements will be very accurate only over a limited latitudinal range. In order to deduce the full gravity field of Jupiter, additional information needs to be incorporated into the analysis, especially regarding the Jovian flow structure and its depth, which can influence the measured gravity field. In this study we propose a new iterative method for the estimation of the Jupiter gravity field, using a simulated Juno trajectory, a trajectory estimation model, and an adjoint-based inverse model for the flow dynamics. We test this method both for zonal harmonics only and with a full gravity field including tesseral harmonics. The results show that this method can fit some of the gravitational harmonics better to the “measured” harmonics, mainly because of the added information from the dynamical model, which includes the flow structure. Thus, it is suggested that the method presented here has the potential of improving the accuracy of the expected gravity harmonics estimated from the Juno and Cassini radio science experiments.

  12. Radar rainfall estimation for the identification of debris-flow precipitation thresholds

    Science.gov (United States)

    Marra, Francesco; Nikolopoulos, Efthymios I.; Creutin, Jean-Dominique; Borga, Marco

    2014-05-01

    Identification of rainfall thresholds for the prediction of debris-flow occurrence is a common approach for warning procedures. Traditionally the debris-flow triggering rainfall is derived from the closest available raingauge. However, the spatial and temporal variability of intense rainfall on mountainous areas, where debris flows take place, may lead to large uncertainty in point-based estimates. Nikolopoulos et al. (2014) have shown that this uncertainty translates into a systematic underestimation of the rainfall thresholds, leading to a step degradation of the performances of the rainfall threshold for identification of debris flows occurrence under operational conditions. A potential solution to this limitation lies on use of rainfall estimates from weather radar. Thanks to their high spatial and temporal resolutions, these estimates offer the advantage of providing rainfall information over the actual debris flow location. The aim of this study is to analyze the value of radar precipitation estimations for the identification of debris flow precipitation thresholds. Seven rainfall events that triggered debris flows in the Adige river basin (Eastern Italian Alps) are analyzed using data from a dense raingauge network and a C-Band weather radar. Radar data are elaborated by using a set of correction algorithms specifically developed for weather radar rainfall application in mountainous areas. Rainfall thresholds for the triggering of debris flows are identified in the form of average intensity-duration power law curves using a frequentist approach by using both radar rainfall estimates and raingauge data. Sampling uncertainty associated to the derivation of the thresholds is assessed by using a bootstrap technique (Peruccacci et al. 2012). Results show that radar-based rainfall thresholds are largely exceeding those obtained by using raingauge data. Moreover, the differences between the two thresholds may be related to the spatial characteristics (i.e., spatial

  13. Flow modelling to estimate suspended sediment travel times for two Canadian Deltas

    Directory of Open Access Journals (Sweden)

    S. R. Fassnacht

    2000-01-01

    Full Text Available The approximate travel times for suspended sediment transport through two multi-channel networks are estimated using flow modelling. The focus is on the movement of high sediment concentrations that travel rapidly downstream. Since suspended sediment transport through river confluences and bifurcation movement is poorly understood, it is assumed that the sediment moves at approximately the average channel velocity during periods of high sediment load movement. Calibration of the flow model is discussed, with an emphasis on the incorporation of cross-section data, that are not referenced to a datum, using a continuous water surface profile. Various flow regimes are examined for the Mackenzie and the Slave River Deltas in the Northwest Territories, Canada, and a significant variation in travel times is illustrated. One set of continuous daily sediment measurements throughout the Mackenzie Delta is used to demonstrate that the travel time estimates are reasonable. Keywords: suspended sediment; multi-channel river systems; flow modelling; sediment transport

  14. Estimation of groundwater flow rate using the decay of 222Rn in a well

    International Nuclear Information System (INIS)

    Hamada, Hiromasa

    1999-01-01

    A method of estimating groundwater flow rate using the decay of 222 Rn in a well was investigated. Field application revealed that infiltrated water (i.e., precipitation, pond water and irrigation water) accelerated groundwater flow. In addition, the depth at which groundwater was influenced by surface water was determined. The velocity of groundwater in a test well was estimated to be of the order of 10 -6 cm s -1 , based on the ratio of 222 Rn concentration in groundwater before and after it flowed into the well. This method is applicable for monitoring of groundwater flow rate where the velocity in a well is from 10 -5 to 10 -6 cm s -1

  15. A Novel Predictor of Posttransplant Portal Hypertension in Adult-To-Adult Living Donor Liver Transplantation: Increased Estimated Spleen/Graft Volume Ratio.

    Science.gov (United States)

    Gyoten, Kazuyuki; Mizuno, Shugo; Kato, Hiroyuki; Murata, Yasuhiro; Tanemura, Akihiro; Azumi, Yoshinori; Kuriyama, Naohisa; Kishiwada, Masashi; Usui, Masanobu; Sakurai, Hiroyuki; Isaji, Shuji

    2016-10-01

    In adult living donor liver transplantation (ALDLT), graft-to-recipient weight ratio of less than 0.8 is incomplete for predicting portal hypertension (>20 mm Hg) after reperfusion. We aimed to identify preoperative factors contributing to portal venous pressure (PVP) after reperfusion and to predict portal hypertension, focusing on spleen volume-to-graft volume ratio (SVGVR). In 73 recipients with ALDLT between 2002 and 2013, first we analyzed survival according to PVP of 20 mm Hg as the threshold, evaluating the efficacy of splenectomy. Second, we evaluated various preoperative factors contributing to portal hypertension after reperfusion. All of the recipients with PVP greater than 20 mm Hg (n = 19) underwent PVP modulation by splenectomy, and their overall survival was favorable compared with 54 recipients who did not need splenectomy (PVP ≤ 20 mm Hg). Graft-to-recipient weight ratio had no correlation with PVP.Multivariate analysis revealed that estimated graft and spleen volume were significant factors contributing to PVP after reperfusion (P portal hypertension was 0.95. In ALDLT, preoperative assessment of SVGVR is a good predictor of portal hypertension after reperfusion can be used to indicate the need for splenectomy before reperfusion.

  16. Estimation of Engine Intake Air Mass Flow using a generic Speed-Density method

    OpenAIRE

    Vojtíšek Michal; Kotek Martin

    2014-01-01

    Measurement of real driving emissions (RDE) from internal combustion engines under real-world operation using portable, onboard monitoring systems (PEMS) is becoming an increasingly important tool aiding the assessment of the effects of new fuels and technologies on environment and human health. The knowledge of exhaust flow is one of the prerequisites for successful RDE measurement with PEMS. One of the simplest approaches for estimating the exhaust flow from virtually any engine is its comp...

  17. 3-D Vector Flow Estimation With Row–Column-Addressed Arrays

    DEFF Research Database (Denmark)

    Holbek, Simon; Christiansen, Thomas Lehrmann; Stuart, Matthias Bo

    2016-01-01

    Simulation and experimental results from 3-D vector flow estimations for a 62 + 62 2-D row–column (RC) array with integrated apodization are presented. A method for implementing a 3-D transverse oscillation (TO) velocity estimator on a 3-MHz RC array is developed and validated. First, a parametric...... mean bias B˜ and mean standard deviation σ˜ . Second, the optimal parameter configuration is implemented on the prototype RC probe connected to the experimental ultrasound scanner SARUS. Results from measurements conducted in a flow-rig system containing a constant laminar flow and a straight.......7, −0.9, 0.4)% with a relative standard deviation of (8.7, 5.1, 0.8)% for (vx , vy, vz). The estimated peak velocity is 48.5 ± 3 cm/s giving a −3% bias. The out-of-plane velocity component perpendicular to the cross section is used to estimate volumetric flow rates in the flow rig at a 90° beam...

  18. Dynamic Phase Boundary Estimation in Two-phase Flows Based on Electrical Impedance Tomography

    International Nuclear Information System (INIS)

    Lee, Jeong Seong; Muhammada, Nauman Malik; Kim, Kyung Youn; Kim, Sin

    2008-01-01

    For the dynamic visualization of the phase boundary in two-phase flows, the electrical impedance tomography (EIT) technique is introduced. In EIT, a set of predetermined electrical currents is injected through the electrodes placed on the boundary of the flow passage and the induced electrical potentials are measured on the electrodes. With the relationship between the injected currents and the induced voltages, the electrical conductivity distribution across the flow domain is estimated through the image reconstruction algorithm where the conductivity distribution corresponds to the phase distribution. In the application of EIT to two-phase flows where there are only two conductivity values, the conductivity distribution estimation problem can be transformed into the boundary estimation problem. This paper considers phase boundary estimation with EIT in annular two-phase flows. As the image reconstruction algorithm, the unscented Kalman filter (UKF) is adopted since from the control theory it is reported that the UKF shows better performance than the extended Kalman filter (EKF) that has been commonly used. For the present problem, the formulation of UKF algorithm involved its incorporation in the adopted image reconstruction algorithm. Also, phantom experiments have been conducted to evaluate the improvement reported by UKF

  19. Bubble boundary estimation in an annulus two-phase flow using electrical impedance tomography

    International Nuclear Information System (INIS)

    Lee, Jeong Seong

    2008-02-01

    For the visualization of the phase boundary in an annulus two-phase flows, the electrical impedance tomography (EIT) technique is introduced. In EIT, a set of predetermined electrical currents is injected trough the electrodes placed on the boundary of the flow passage and the induced electrical potentials are measured on the electrode. With the relationship between the injected currents and the induced voltages, the electrical conductivity distribution across the flow domain is estimated through the image reconstruction algorithm. In this, the conductivity distribution corresponds to the phase distribution. In the application of EIT to two-phase flows where there are only two conductivity values, the conductivity distribution estimation problem can be transformed into the boundary estimation problem. This paper considers a bubble boundary estimation with EIT in an annulus two-phase flows. And in many industrial cases there are a priori known internal structures inside the vessels which could be used as internal electrodes in tomographical imaging. In this paper internal electrodes were considered in electrical impedance tomography. As the image reconstruction algorithm, the unscented Kalman filter (UKF) is adopted since from the control theory it is reported that the UKF shows better performance than the extended Kalman filter (EKF) that has been commonly used. The UKF algorithm was formulated to be incorporate into the image reconstruction algorithm for the present problem. Also, phantom experiments have been conducted to evaluate the improvement by UKF

  20. Estimation of the flow resistances exerted in coronary arteries using a vessel length-based method.

    Science.gov (United States)

    Lee, Kyung Eun; Kwon, Soon-Sung; Ji, Yoon Cheol; Shin, Eun-Seok; Choi, Jin-Ho; Kim, Sung Joon; Shim, Eun Bo

    2016-08-01

    Flow resistances exerted in the coronary arteries are the key parameters for the image-based computer simulation of coronary hemodynamics. The resistances depend on the anatomical characteristics of the coronary system. A simple and reliable estimation of the resistances is a compulsory procedure to compute the fractional flow reserve (FFR) of stenosed coronary arteries, an important clinical index of coronary artery disease. The cardiac muscle volume reconstructed from computed tomography (CT) images has been used to assess the resistance of the feeding coronary artery (muscle volume-based method). In this study, we estimate the flow resistances exerted in coronary arteries by using a novel method. Based on a physiological observation that longer coronary arteries have more daughter branches feeding a larger mass of cardiac muscle, the method measures the vessel lengths from coronary angiogram or CT images (vessel length-based method) and predicts the coronary flow resistances. The underlying equations are derived from the physiological relation among flow rate, resistance, and vessel length. To validate the present estimation method, we calculate the coronary flow division over coronary major arteries for 50 patients using the vessel length-based method as well as the muscle volume-based one. These results are compared with the direct measurements in a clinical study. Further proving the usefulness of the present method, we compute the coronary FFR from the images of optical coherence tomography.

  1. IN-CYLINDER MASS FLOW ESTIMATION AND MANIFOLD PRESSURE DYNAMICS FOR STATE PREDICTION IN SI ENGINES

    Directory of Open Access Journals (Sweden)

    Wojnar Sławomir

    2014-06-01

    Full Text Available The aim of this paper is to present a simple model of the intake manifold dynamics of a spark ignition (SI engine and its possible application for estimation and control purposes. We focus on pressure dynamics, which may be regarded as the foundation for estimating future states and for designing model predictive control strategies suitable for maintaining the desired air fuel ratio (AFR. The flow rate measured at the inlet of the intake manifold and the in-cylinder flow estimation are considered as parts of the proposed model. In-cylinder flow estimation is crucial for engine control, where an accurate amount of aspired air forms the basis for computing the manipulated variables. The solutions presented here are based on the mean value engine model (MVEM approach, using the speed-density method. The proposed in-cylinder flow estimation method is compared to measured values in an experimental setting, while one-step-ahead prediction is illustrated using simulation results.

  2. Estimating Probable Maximum Precipitation by Considering Combined Effect of Typhoon and Southwesterly Air Flow

    Directory of Open Access Journals (Sweden)

    Cheng-Chin Liu

    2016-01-01

    Full Text Available Typhoon Morakot hit southern Taiwan in 2009, bringing 48-hr of heavy rainfall [close to the Probable Maximum Precipitation (PMP] to the Tsengwen Reservoir catchment. This extreme rainfall event resulted from the combined (co-movement effect of two climate systems (i.e., typhoon and southwesterly air flow. Based on the traditional PMP estimation method (i.e., the storm transposition method, STM, two PMP estimation approaches, i.e., Amplification Index (AI and Independent System (IS approaches, which consider the combined effect are proposed in this work. The AI approach assumes that the southwesterly air flow precipitation in a typhoon event could reach its maximum value. The IS approach assumes that the typhoon and southwesterly air flow are independent weather systems. Based on these assumptions, calculation procedures for the two approaches were constructed for a case study on the Tsengwen Reservoir catchment. The results show that the PMP estimates for 6- to 60-hr durations using the two approaches are approximately 30% larger than the PMP estimates using the traditional STM without considering the combined effect. This work is a pioneer PMP estimation method that considers the combined effect of a typhoon and southwesterly air flow. Further studies on this issue are essential and encouraged.

  3. Estimating the system price of redox flow batteries for grid storage

    Science.gov (United States)

    Ha, Seungbum; Gallagher, Kevin G.

    2015-11-01

    Low-cost energy storage systems are required to support extensive deployment of intermittent renewable energy on the electricity grid. Redox flow batteries have potential advantages to meet the stringent cost target for grid applications as compared to more traditional batteries based on an enclosed architecture. However, the manufacturing process and therefore potential high-volume production price of redox flow batteries is largely unquantified. We present a comprehensive assessment of a prospective production process for aqueous all vanadium flow battery and nonaqueous lithium polysulfide flow battery. The estimated investment and variable costs are translated to fixed expenses, profit, and warranty as a function of production volume. When compared to lithium-ion batteries, redox flow batteries are estimated to exhibit lower costs of manufacture, here calculated as the unit price less materials costs, owing to their simpler reactor (cell) design, lower required area, and thus simpler manufacturing process. Redox flow batteries are also projected to achieve the majority of manufacturing scale benefits at lower production volumes as compared to lithium-ion. However, this advantage is offset due to the dramatically lower present production volume of flow batteries compared to competitive technologies such as lithium-ion.

  4. Estimation of natural historical flows for the Manitowish River near Manitowish Waters, Wisconsin

    Science.gov (United States)

    Juckem, Paul F.; Reneau, Paul C.; Robertson, Dale M.

    2012-01-01

    The Wisconsin Department of Natural Resources is charged with oversight of dam operations throughout Wisconsin and is considering modifications to the operating orders for the Rest Lake Dam in Vilas County, Wisconsin. State law requires that the operation orders be tied to natural low flows at the dam. Because the presence of the dam confounds measurement of natural flows, the U.S. Geological Survey, in cooperation with the Wisconsin Department of Natural Resources, installed streamflow-gaging stations and developed two statistical methods to improve estimates of natural flows at the Rest Lake Dam. Two independent methods were used to estimate daily natural flow for the Manitowish River approximately 1 mile downstream of the Rest Lake Dam. The first method was an adjusted drainage-area ratio method, which used a regression analysis that related measured water yield (flow divided by watershed area) from short-term (2009–11) gaging stations upstream of the Manitowish Chain of Lakes to the water yield from two nearby long-term gaging stations in order to extend the flow record (1991–2011). In this approach, the computed flows into the Chain of Lakes at the upstream gaging stations were multiplied by a coefficient to account for the monthly hydrologic contributions (precipitation, evaporation, groundwater, and runoff) associated with the additional watershed area between the upstream gaging stations and the dam at the outlet of the Chain of Lakes (Rest Lake Dam). The second method used to estimate daily natural flow at the Rest Lake Dam was a water-budget approach, which used lake stage and dam outflow data provided by the dam operator. A water-budget model was constructed and then calibrated with an automated parameter-estimation program by matching simulated flow-duration statistics with measured flow-duration statistics at the upstream gaging stations. After calibration of the water-budget model, the model was used to compute natural flow at the dam from 1973 to

  5. Determination of the equation parameters of carbon flow curves and estimated carbon flow and CO2 emissions from broiler production.

    Science.gov (United States)

    Henn, J D; Bockor, L; Borille, R; Coldebella, A; Ribeiro, A M L; Kessler, A M

    2015-09-01

    The objective of this study was to determine the equation parameters of carbon (i.e., C) flow curves and to estimate C flow and carbon dioxide (i.e., CO2) emissions from the production of 1- to 49-day-old broilers from different genetic strains. In total, 384 1-day-old chicks were used, distributed into 4 groups: high-performance males (Cobb-M) and females (Cobb-F), and intermediate-performance males (C44-M) and females (C44-F), with 6 replicates/treatment according to a completely randomized study design. Carbon intake and retention were calculated based on diet and body C composition, and expired C was stoichiometrically estimated as digestible C intake-C retention-C in the urine. Litter C emission was estimated as initial litter C+C in the excreta-final litter C. Carbon flow curves were determined fitting data by nonlinear regression using the Gompertz function. Expired CO2 was calculated based on expired C. The applied nonlinear model presented goodness-of-fit for all responses (R2>0.99). Carbon dioxide production was highly correlated with growth rate. At 42 d age, CO2 expiration (g/bird) was 3,384.4 for Cobb-M, 2,947.9 for Cobb-F, 2,512.5 for C44-M, and 2185.1 for C44-F. Age also significantly affected CO2 production: to achieve 2.0 kg BW, CO2 expiration (g/bird) was 1,794.3 for Cobb-M, 2,016.5 for Cobb-F, 2617.7 for C44-M, and 3,092.3 for C44-F. The obtained equations present high predictability to estimate individual CO2 emissions in strains of Cobb and C44 broilers of any weight, or age, reared between 1 and 49 d age. © 2015 Poultry Science Association Inc.

  6. Parameter estimation techniques and uncertainty in ground water flow model predictions

    International Nuclear Information System (INIS)

    Zimmerman, D.A.; Davis, P.A.

    1990-01-01

    Quantification of uncertainty in predictions of nuclear waste repository performance is a requirement of Nuclear Regulatory Commission regulations governing the licensing of proposed geologic repositories for high-level radioactive waste disposal. One of the major uncertainties in these predictions is in estimating the ground-water travel time of radionuclides migrating from the repository to the accessible environment. The cause of much of this uncertainty has been attributed to a lack of knowledge about the hydrogeologic properties that control the movement of radionuclides through the aquifers. A major reason for this lack of knowledge is the paucity of data that is typically available for characterizing complex ground-water flow systems. Because of this, considerable effort has been put into developing parameter estimation techniques that infer property values in regions where no measurements exist. Currently, no single technique has been shown to be superior or even consistently conservative with respect to predictions of ground-water travel time. This work was undertaken to compare a number of parameter estimation techniques and to evaluate how differences in the parameter estimates and the estimation errors are reflected in the behavior of the flow model predictions. That is, we wished to determine to what degree uncertainties in flow model predictions may be affected simply by the choice of parameter estimation technique used. 3 refs., 2 figs

  7. Recruitment of feces donors among blood donors

    DEFF Research Database (Denmark)

    Dahl Jørgensen, Simon Mark; Erikstrup, Christian; Dinh, Khoa Manh

    2018-01-01

    As the use of fecal microbiota transplantation (FMT) has gained momentum, an increasing need for continuous access to healthy feces donors has developed. Blood donors constitute a healthy subset of the general population and may serve as an appropriate group for recruitment. In this study, we...... investigated the suitability of blood donors as feces donors. In a prospective cohort study, we recruited blood donors onsite at a public Danish blood bank. Following their consent, the blood donors underwent a stepwise screening process: First, blood donors completed an electronic pre-screening questionnaire...... to rule out predisposing risk factors. Second, eligible blood donors had blood and fecal samples examined. Of 155 blood donors asked to participate, 137 (88%) completed the electronic pre-screening questionnaire, 16 declined, and 2 were excluded. Of the 137 donors who completed the questionnaire, 79 (58...

  8. Erosion estimation of guide vane end clearance in hydraulic turbines with sediment water flow

    Science.gov (United States)

    Han, Wei; Kang, Jingbo; Wang, Jie; Peng, Guoyi; Li, Lianyuan; Su, Min

    2018-04-01

    The end surface of guide vane or head cover is one of the most serious parts of sediment erosion for high-head hydraulic turbines. In order to investigate the relationship between erosion depth of wall surface and the characteristic parameter of erosion, an estimative method including a simplified flow model and a modificatory erosion calculative function is proposed in this paper. The flow between the end surfaces of guide vane and head cover is simplified as a clearance flow around a circular cylinder with a backward facing step. Erosion characteristic parameter of csws3 is calculated with the mixture model for multiphase flow and the renormalization group (RNG) k-𝜀 turbulence model under the actual working conditions, based on which, erosion depths of guide vane and head cover end surfaces are estimated with a modification of erosion coefficient K. The estimation results agree well with the actual situation. It is shown that the estimative method is reasonable for erosion prediction of guide vane and can provide a significant reference to determine the optimal maintenance cycle for hydraulic turbine in the future.

  9. ESTIMATION OF THE DECREASING OF 137 CS SEDIMENT IN THE SOIL DUE TO HORIZONTAL FLOWING

    Directory of Open Access Journals (Sweden)

    O. N. Prokof'ev

    2008-01-01

    Full Text Available The purpose of work is to estimate the possible decreasing of the density of  137 Cs sediment in the soil influenced by the horizontal flowing basing on the analysis of on location observations on the density of  137 Cs sediment in the soil after the Chernobyl accident.

  10. Automated estimation of defects in magnetographic defectoscopy. 1. Automated magnetographic flow detectors

    International Nuclear Information System (INIS)

    Mikhajlov, S.P.; Vaulin, S.L.; Shcherbinin, V.E.; Shur, M.L.

    1993-01-01

    Consideration is given to specific features and possible functions of equipment for automated estimation of stretched continuity defects for samples with plane surface in magnetographic defectoscopy are discussed. Two models of automated magnetographic flow detectors, those with built-in microcomputer and in the form computer attachment, are described. Directions of further researches and development are discussed. 35 refs., 6 figs

  11. Estimation of the Heat Flow Variation in the Chad Basin Nigeria ...

    African Journals Online (AJOL)

    Wireline logs from 14 oil wells from the Nigerian sector of the Chad Basin were analyzed and interpreted to estimate the heat flow trend in the basin. Geothermal gradients were computed from corrected bottom hole temperatures while the bulk effective thermal conductivity for the different stratigraphic units encountered in ...

  12. Robust Non-Local TV-L1 Optical Flow Estimation with Occlusion Detection.

    Science.gov (United States)

    Zhang, Congxuan; Chen, Zhen; Wang, Mingrun; Li, Ming; Jiang, Shaofeng

    2017-06-05

    In this paper, we propose a robust non-local TV-L1 optical flow method with occlusion detection to address the problem of weak robustness of optical flow estimation with motion occlusion. Firstly, a TV-L1 form for flow estimation is defined using a combination of the brightness constancy and gradient constancy assumptions in the data term and by varying the weight under the Charbonnier function in the smoothing term. Secondly, to handle the potential risk of the outlier in the flow field, a general non-local term is added in the TV-L1 optical flow model to engender the typical non-local TV-L1 form. Thirdly, an occlusion detection method based on triangulation is presented to detect the occlusion regions of the sequence. The proposed non-local TV-L1 optical flow model is performed in a linearizing iterative scheme using improved median filtering and a coarse-to-fine computing strategy. The results of the complex experiment indicate that the proposed method can overcome the significant influence of non-rigid motion, motion occlusion, and large displacement motion. Results of experiments comparing the proposed method and existing state-of-the-art methods by respectively using Middlebury and MPI Sintel database test sequences show that the proposed method has higher accuracy and better robustness.

  13. Estimating the vibration level of an L-shaped beam using power flow techniques

    Science.gov (United States)

    Cuschieri, J. M.; Mccollum, M.; Rassineux, J. L.; Gilbert, T.

    1986-01-01

    The response of one component of an L-shaped beam, with point force excitation on the other component, is estimated using the power flow method. The transmitted power from the source component to the receiver component is expressed in terms of the transfer and input mobilities at the excitation point and the joint. The response is estimated both in narrow frequency bands, using the exact geometry of the beams, and as a frequency averaged response using infinite beam models. The results using this power flow technique are compared to the results obtained using finite element analysis (FEA) of the L-shaped beam for the low frequency response and to results obtained using statistical energy analysis (SEA) for the high frequencies. The agreement between the FEA results and the power flow method results at low frequencies is very good. SEA results are in terms of frequency averaged levels and these are in perfect agreement with the results obtained using the infinite beam models in the power flow method. The narrow frequency band results from the power flow method also converge to the SEA results at high frequencies. The advantage of the power flow method is that detail of the response can be retained while reducing computation time, which will allow the narrow frequency band analysis of the response to be extended to higher frequencies.

  14. Estimation of Particle Material And Dissolved Flows During Floods In The Inaouene Watershed. (Northeast Of Morocco)

    Science.gov (United States)

    Sibari, Hayat; Haida, Souad; Foutlane, Mohamed

    2018-05-01

    This work aims to estimate the contributions of the Inaouene River during the floods. It is in this context that the dissolved and particulate matter flows were measured during the flood periods followed by the 1996/97 study year at the two hydrological stations Bab Marzouka (upstream) and El Kouchat (downstream). The specific flows of dissolved materials calculated upstream and downstream of the Inaouene watershed correspond respectively to 257 t/ km2/year and 117 t/ km2/year. Chlorides represent 30% and 41% respectively of the total dissolved transport upstream and downstream. The potential mechanical degradation affecting the Inaouene watershed can deliver a solid load estimated at 6.106 t/year corresponding to a specific flow of 2142 t/km2/year.

  15. Optic flow estimation on trajectories generated by bio-inspired closed-loop flight.

    Science.gov (United States)

    Shoemaker, Patrick A; Hyslop, Andrew M; Humbert, J Sean

    2011-05-01

    We generated panoramic imagery by simulating a fly-like robot carrying an imaging sensor, moving in free flight through a virtual arena bounded by walls, and containing obstructions. Flight was conducted under closed-loop control by a bio-inspired algorithm for visual guidance with feedback signals corresponding to the true optic flow that would be induced on an imager (computed by known kinematics and position of the robot relative to the environment). The robot had dynamics representative of a housefly-sized organism, although simplified to two-degree-of-freedom flight to generate uniaxial (azimuthal) optic flow on the retina in the plane of travel. Surfaces in the environment contained images of natural and man-made scenes that were captured by the moving sensor. Two bio-inspired motion detection algorithms and two computational optic flow estimation algorithms were applied to sequences of image data, and their performance as optic flow estimators was evaluated by estimating the mutual information between outputs and true optic flow in an equatorial section of the visual field. Mutual information for individual estimators at particular locations within the visual field was surprisingly low (less than 1 bit in all cases) and considerably poorer for the bio-inspired algorithms that the man-made computational algorithms. However, mutual information between weighted sums of these signals and comparable sums of the true optic flow showed significant increases for the bio-inspired algorithms, whereas such improvement did not occur for the computational algorithms. Such summation is representative of the spatial integration performed by wide-field motion-sensitive neurons in the third optic ganglia of flies.

  16. Estimation of regional-scale groundwater flow properties in the Bengal Basin of India and Bangladesh

    Science.gov (United States)

    Michael, H.A.; Voss, C.I.

    2009-01-01

    Quantitative evaluation of management strategies for long-term supply of safe groundwater for drinking from the Bengal Basin aquifer (India and Bangladesh) requires estimation of the large-scale hydrogeologic properties that control flow. The Basin consists of a stratified, heterogeneous sequence of sediments with aquitards that may separate aquifers locally, but evidence does not support existence of regional confining units. Considered at a large scale, the Basin may be aptly described as a single aquifer with higher horizontal than vertical hydraulic conductivity. Though data are sparse, estimation of regional-scale aquifer properties is possible from three existing data types: hydraulic heads, 14C concentrations, and driller logs. Estimation is carried out with inverse groundwater modeling using measured heads, by model calibration using estimated water ages based on 14C, and by statistical analysis of driller logs. Similar estimates of hydraulic conductivities result from all three data types; a resulting typical value of vertical anisotropy (ratio of horizontal to vertical conductivity) is 104. The vertical anisotropy estimate is supported by simulation of flow through geostatistical fields consistent with driller log data. The high estimated value of vertical anisotropy in hydraulic conductivity indicates that even disconnected aquitards, if numerous, can strongly control the equivalent hydraulic parameters of an aquifer system. ?? US Government 2009.

  17. Methods for estimating wake flow and effluent dispersion near simple block-like buildings

    International Nuclear Information System (INIS)

    Hosker, R.P. Jr.

    1981-05-01

    This report is intended as an interim guide for those who routinely face air quality problems associated with near-building exhaust stack placement and height, and the resulting concentration patterns. Available data and methods for estimating wake flow and effluent dispersion near isolated block-like structures are consolidated. The near-building and wake flows are described, and quantitative estimates for frontal eddy size, height and extent of roof and wake cavities, and far wake behavior are provided. Concentration calculation methods for upwind, near-building, and downwind pollutant sources are given. For an upwind source, it is possible to estimate the required stack height, and to place upper limits on the likely near-building concentration. The influences of near-building source location and characteristics relative to the building geometry and orientation are considered. Methods to estimate effective stack height, upper limits for concentration due to flush roof vents, and the effect of changes in rooftop stack height are summarized. Current wake and wake cavity models are presented. Numerous graphs of important expressions have been prepared to facilitate computations and quick estimates of flow patterns and concentration levels for specific simple buildings. Detailed recommendations for additional work are given

  18. A predictor-corrector algorithm to estimate the fractional flow in oil-water models

    International Nuclear Information System (INIS)

    Savioli, Gabriela B; Berdaguer, Elena M Fernandez

    2008-01-01

    We introduce a predictor-corrector algorithm to estimate parameters in a nonlinear hyperbolic problem. It can be used to estimate the oil-fractional flow function from the Buckley-Leverett equation. The forward model is non-linear: the sought- for parameter is a function of the solution of the equation. Traditionally, the estimation of functions requires the selection of a fitting parametric model. The algorithm that we develop does not require a predetermined parameter model. Therefore, the estimation problem is carried out over a set of parameters which are functions. The algorithm is based on the linearization of the parameter-to-output mapping. This technique is new in the field of nonlinear estimation. It has the advantage of laying aside parametric models. The algorithm is iterative and is of predictor-corrector type. We present theoretical results on the inverse problem. We use synthetic data to test the new algorithm.

  19. Use of flow cytometry for high-throughput cell population estimates in fixed brain tissue

    Directory of Open Access Journals (Sweden)

    Nicole A Young

    2012-07-01

    Full Text Available The numbers and types of cells in an area of cortex define its function. Therefore it is essential to characterize the numbers and distributions of total cells in areas of the cortex, as well as to identify numbers of subclasses of neurons and glial cells. To date, the large size of the primate brain and the lack of innovation in cell counting methods have been a roadblock to obtaining high-resolution maps of cell and neuron density across the cortex in humans and non-human primates. Stereological counting methods and the isotropic fractionator are valuable tools for estimating cell numbers, but are better suited to smaller, well-defined brain structures or to cortex as a whole. In the present study, we have extended our flow-cytometry based counting method, the flow fractionator (Collins et al., 2010a, to include high-throughput total cell population estimates in homogenized cortical samples. We demonstrate that our method produces consistent, accurate and repeatable cell estimates quickly. The estimates we report are in excellent agreement with estimates for the same samples obtained using a Neubauer chamber and a fluorescence microscope. We show that our flow cytometry-based method for total cell estimation in homogenized brain tissue is more efficient and more precise than manual counting methods. The addition of automated nuclei counting to our flow fractionator method allows for a fully automated, rapid characterization of total cells and neuronal and non-neuronal populations in human and non-human primate brains, providing valuable data to further our understanding of the functional organization of normal, aging and diseased brains.

  20. Estimation of Rheological Properties of Viscous Debris Flow Using a Belt Conveyor

    Science.gov (United States)

    Hübl, J.; Steinwendtner, H.

    2000-09-01

    Rheological parameters of viscous debris flows are influenced by a great amount of factors and are therefore extremely difficult to estimate. Because of this uncertainties a belt conveyor (conveyor channel) was constructed to measure flow behaviour and rheological properties of natural debris flow material. The upward movement of the smooth rubberised belt between fixed lateral plastic walls causes a stationary wave relative to these bends. This special experimental design enables to study behaviour of viscous ebris flow material with maximum grain diameters up to 20 mm within several minutes and to hold measuring equipment very simple. The conveyor channel was calibrated first with Xanthan, a natural polysaccharide used as thickener in food technology, whose rheological properties are similar to viscous debris flow material. In a second step natural debris flow material was investigated. Velocities and rheological parameters were measured with varying solid concentration and slope of the channel. In cases where concentration of coarse particles exceed around 15% by volume the conveyor channel obtains an alternative to expensive commercial viscometers for determination of rheological parameters of viscous debris flows.

  1. Modification of Turbulent Pipe Flow Equations to Estimate the Vertical Velocity Profiles Under Woody Debris Jams

    Science.gov (United States)

    Cervania, A.; Knack, I. M. W.

    2017-12-01

    The presence of woody debris (WD) jams in rivers and streams increases the risk of backwater flooding and reduces the navigability of a channel, but adds fish and macroinvertebrate habitat to the stream. When designing river engineering projects engineers use hydraulic models to predict flow behavior around these obstructions. However, the complexities of flow through and beneath WD jams are still poorly understood. By increasing the ability to predict flow behavior around WD jams, landowners and engineers are empowered to develop sustainable practices regarding the removal or placement of WD in rivers and flood plains to balance the desirable and undesirable effects to society and the environment. The objective of this study is to address some of this knowledge gap by developing a method to estimate the vertical velocity profile of flow under WD jams. When flow passes under WD jams, it becomes affected by roughness elements on all sides, similar to turbulent flows in pipe systems. Therefore, the method was developed using equations that define the velocity profiles of turbulent pipe flows: the law of the wall, the logarithmic law, and the velocity defect law. Flume simulations of WD jams were conducted and the vertical velocity profiles were measured along the centerline. A calculated velocity profile was fit to the measured profile through the calibration of eight parameters. An optimal value or range of values have been determined for several of these parameters using cross-validation techniques. The results indicate there may be some promise to using this method in hydraulic models.

  2. Viscosity estimation utilizing flow velocity field measurements in a rotating magnetized plasma

    International Nuclear Information System (INIS)

    Yoshimura, Shinji; Tanaka, Masayoshi Y.

    2008-01-01

    The importance of viscosity in determining plasma flow structures has been widely recognized. In laboratory plasmas, however, viscosity measurements have been seldom performed so far. In this paper we present and discuss an estimation method of effective plasma kinematic viscosity utilizing flow velocity field measurements. Imposing steady and axisymmetric conditions, we derive the expression for radial flow velocity from the azimuthal component of the ion fluid equation. The expression contains kinematic viscosity, vorticity of azimuthal rotation and its derivative, collision frequency, azimuthal flow velocity and ion cyclotron frequency. Therefore all quantities except the viscosity are given provided that the flow field can be measured. We applied this method to a rotating magnetized argon plasma produced by the Hyper-I device. The flow velocity field measurements were carried out using a directional Langmuir probe installed in a tilting motor drive unit. The inward ion flow in radial direction, which is not driven in collisionless inviscid plasmas, was clearly observed. As a result, we found the anomalous viscosity, the value of which is two orders of magnitude larger than the classical one. (author)

  3. Satellite Angular Velocity Estimation Based on Star Images and Optical Flow Techniques

    Directory of Open Access Journals (Sweden)

    Giancarmine Fasano

    2013-09-01

    Full Text Available An optical flow-based technique is proposed to estimate spacecraft angular velocity based on sequences of star-field images. It does not require star identification and can be thus used to also deliver angular rate information when attitude determination is not possible, as during platform de tumbling or slewing. Region-based optical flow calculation is carried out on successive star images preprocessed to remove background. Sensor calibration parameters, Poisson equation, and a least-squares method are then used to estimate the angular velocity vector components in the sensor rotating frame. A theoretical error budget is developed to estimate the expected angular rate accuracy as a function of camera parameters and star distribution in the field of view. The effectiveness of the proposed technique is tested by using star field scenes generated by a hardware-in-the-loop testing facility and acquired by a commercial-off-the shelf camera sensor. Simulated cases comprise rotations at different rates. Experimental results are presented which are consistent with theoretical estimates. In particular, very accurate angular velocity estimates are generated at lower slew rates, while in all cases the achievable accuracy in the estimation of the angular velocity component along boresight is about one order of magnitude worse than the other two components.

  4. Velocity vector estimation in synthetic aperture flow and B-mode imaging

    DEFF Research Database (Denmark)

    Jensen, Jørgen Arendt

    2004-01-01

    A method for determining both velocity magnitude and angle in a synthetic aperture ultrasound system is described. The approach uses directional beamforming along the flow direction and cross-correlation to determine velocity magnitude. The angle of the flow is determined from the maximum normali...... with a precision of 0.36 % (60°) and 1.2 % (90°), respectively. The 60° angle is estimated with a bias of 0.54° and a standard deviation of 2.1°. For 90° the bias is 0.0003° and standard deviation 1.32°....

  5. Review of flow rate estimates of the Deepwater Horizon oil spill

    OpenAIRE

    McNutt, Marcia K.; Camilli, Rich; Crone, Timothy J.; Guthrie, George D.; Hsieh, Paul A.; Ryerson, Thomas B.; Savas, Omer; Shaffer, Frank

    2011-01-01

    The unprecedented nature of the Deepwater Horizon oil spill required the application of research methods to estimate the rate at which oil was escaping from the well in the deep sea, its disposition after it entered the ocean, and total reservoir depletion. Here, we review what advances were made in scientific understanding of quantification of flow rates during deep sea oil well blowouts. We assess the degree to which a consensus was reached on the flow rate of the well by comparing in situ ...

  6. Computational Fluid Dynamic Pressure Drop Estimation of Flow between Parallel Plates

    Energy Technology Data Exchange (ETDEWEB)

    Son, Hyung Min; Yang, Soo Hyung; Park, Jong Hark [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-10-15

    Many pool type reactors have forced downward flows inside the core during normal operation; there is a chance of flow inversion when transients occur. During this phase, the flow undergo transition between turbulent and laminar regions where drastic changes take place in terms of momentum and heat transfer, and the decrease in safety margin is usually observed. Additionally, for high Prandtl number fluids such as water, an effect of the velocity profile inside the channel on the temperature distribution is more pronounced over the low Prandtl number ones. This makes the checking of its pressure drop estimation accuracy less important, assuming the code verification is complete. With an advent of powerful computer hardware, engineering applications of computational fluid dynamics (CFD) methods have become quite common these days. Especially for a fully-turbulent and single phase convective heat transfer, the predictability of the commercial codes has matured enough so that many well-known companies adopt those to accelerate a product development cycle and to realize an increased profitability. In contrast to the above, the transition models for the CFD code are still under development, and the most of the models show limited generality and prediction accuracy. Unlike the system codes, the CFD codes estimate the pressure drop from the velocity profile which is obtained by solving momentum conservation equations, and the resulting friction factor can be a representative parameter for a constant cross section channel flow. In addition, the flow inside a rectangular channel with a high span to gap ratio can be approximated by flow inside parallel plates. The computational fluid dynamics simulation on the flow between parallel plates showed reasonable prediction capability for the laminar and the turbulent regime.

  7. Comparison of blood flow models and acquisitions for quantitative myocardial perfusion estimation from dynamic CT

    International Nuclear Information System (INIS)

    Bindschadler, Michael; Alessio, Adam M; Modgil, Dimple; La Riviere, Patrick J; Branch, Kelley R

    2014-01-01

    Myocardial blood flow (MBF) can be estimated from dynamic contrast enhanced (DCE) cardiac CT acquisitions, leading to quantitative assessment of regional perfusion. The need for low radiation dose and the lack of consensus on MBF estimation methods motivates this study to refine the selection of acquisition protocols and models for CT-derived MBF. DCE cardiac CT acquisitions were simulated for a range of flow states (MBF = 0.5, 1, 2, 3 ml (min g) −1 , cardiac output = 3, 5, 8 L min −1 ). Patient kinetics were generated by a mathematical model of iodine exchange incorporating numerous physiological features including heterogenenous microvascular flow, permeability and capillary contrast gradients. CT acquisitions were simulated for multiple realizations of realistic x-ray flux levels. CT acquisitions that reduce radiation exposure were implemented by varying both temporal sampling (1, 2, and 3 s sampling intervals) and tube currents (140, 70, and 25 mAs). For all acquisitions, we compared three quantitative MBF estimation methods (two-compartment model, an axially-distributed model, and the adiabatic approximation to the tissue homogeneous model) and a qualitative slope-based method. In total, over 11 000 time attenuation curves were used to evaluate MBF estimation in multiple patient and imaging scenarios. After iodine-based beam hardening correction, the slope method consistently underestimated flow by on average 47.5% and the quantitative models provided estimates with less than 6.5% average bias and increasing variance with increasing dose reductions. The three quantitative models performed equally well, offering estimates with essentially identical root mean squared error (RMSE) for matched acquisitions. MBF estimates using the qualitative slope method were inferior in terms of bias and RMSE compared to the quantitative methods. MBF estimate error was equal at matched dose reductions for all quantitative methods and range of techniques evaluated. This

  8. Estimation of gas wall shear stress in horizontal stratified gas-liquid pipe flow

    International Nuclear Information System (INIS)

    Newton, C.H.; Behnia, M.

    1996-01-01

    Two-phase pipe flows occur in many industrial applications, such as condensers and evaporators, chemical processing equipment, nuclear reactors, and oil pipelines. A variety of basic mechanistic flow models for predicting the pressure gradient and liquid loading characteristics of these types of flows to assist in design calculations has emerged over the past two decades, especially for the stratified and slug flow regimes. These models generally rely on a number of basic assumptions and empirical closure equations. Possibly the most notable of these relates to the evaluation of interfacial shear stresses. However, one of the most important yet least discussed assumptions used in most of these models is that the phase wall shear stresses can be accurately estimated from correlations developed for single-phase pipe flows. The object of this article is to present measurements of gas wall shear up to locations in close proximity to the gas-liquid interface for a variety of interface conditions in developed flow, and to determine the effects of the interface on average gas wall friction factors. In this context the interface may be smooth, rippled or wavy

  9. An inverse method to estimate the flow through a levee breach

    Science.gov (United States)

    D'Oria, Marco; Mignosa, Paolo; Tanda, Maria Giovanna

    2015-08-01

    We propose a procedure to estimate the flow through a levee breach based on water levels recorded in river stations downstream and/or upstream of the failure site. The inverse problem is solved using a Bayesian approach and requires the execution of several forward unsteady flow simulations. For this purpose, we have used the well-known 1-D HEC-RAS model, but any unsteady flow model could be adopted in the same way. The procedure has been tested using four synthetic examples. Levee breaches with different characteristics (free flow, flow with tailwater effects, etc.) have been simulated to collect the synthetic level data used at a later stage in the inverse procedure. The method was able to accurately reproduce the flow through the breach in all cases. The practicability of the procedure was then confirmed applying it to the inundation of the Polesine Region (Northern Italy) which occurred in 1951 and was caused by three contiguous and almost simultaneous breaches on the left embankment of the Po River.

  10. Methods for estimating flow-duration curve and low-flow frequency statistics for ungaged locations on small streams in Minnesota

    Science.gov (United States)

    Ziegeweid, Jeffrey R.; Lorenz, David L.; Sanocki, Chris A.; Czuba, Christiana R.

    2015-12-24

    Knowledge of the magnitude and frequency of low flows in streams, which are flows in a stream during prolonged dry weather, is fundamental for water-supply planning and design; waste-load allocation; reservoir storage design; and maintenance of water quality and quantity for irrigation, recreation, and wildlife conservation. This report presents the results of a statewide study for which regional regression equations were developed for estimating 13 flow-duration curve statistics and 10 low-flow frequency statistics at ungaged stream locations in Minnesota. The 13 flow-duration curve statistics estimated by regression equations include the 0.0001, 0.001, 0.02, 0.05, 0.1, 0.25, 0.50, 0.75, 0.9, 0.95, 0.99, 0.999, and 0.9999 exceedance-probability quantiles. The low-flow frequency statistics include annual and seasonal (spring, summer, fall, winter) 7-day mean low flows, seasonal 30-day mean low flows, and summer 122-day mean low flows for a recurrence interval of 10 years. Estimates of the 13 flow-duration curve statistics and the 10 low-flow frequency statistics are provided for 196 U.S. Geological Survey continuous-record streamgages using streamflow data collected through September 30, 2012.

  11. An iterative stochastic ensemble method for parameter estimation of subsurface flow models

    International Nuclear Information System (INIS)

    Elsheikh, Ahmed H.; Wheeler, Mary F.; Hoteit, Ibrahim

    2013-01-01

    Parameter estimation for subsurface flow models is an essential step for maximizing the value of numerical simulations for future prediction and the development of effective control strategies. We propose the iterative stochastic ensemble method (ISEM) as a general method for parameter estimation based on stochastic estimation of gradients using an ensemble of directional derivatives. ISEM eliminates the need for adjoint coding and deals with the numerical simulator as a blackbox. The proposed method employs directional derivatives within a Gauss–Newton iteration. The update equation in ISEM resembles the update step in ensemble Kalman filter, however the inverse of the output covariance matrix in ISEM is regularized using standard truncated singular value decomposition or Tikhonov regularization. We also investigate the performance of a set of shrinkage based covariance estimators within ISEM. The proposed method is successfully applied on several nonlinear parameter estimation problems for subsurface flow models. The efficiency of the proposed algorithm is demonstrated by the small size of utilized ensembles and in terms of error convergence rates

  12. An iterative stochastic ensemble method for parameter estimation of subsurface flow models

    KAUST Repository

    Elsheikh, Ahmed H.

    2013-06-01

    Parameter estimation for subsurface flow models is an essential step for maximizing the value of numerical simulations for future prediction and the development of effective control strategies. We propose the iterative stochastic ensemble method (ISEM) as a general method for parameter estimation based on stochastic estimation of gradients using an ensemble of directional derivatives. ISEM eliminates the need for adjoint coding and deals with the numerical simulator as a blackbox. The proposed method employs directional derivatives within a Gauss-Newton iteration. The update equation in ISEM resembles the update step in ensemble Kalman filter, however the inverse of the output covariance matrix in ISEM is regularized using standard truncated singular value decomposition or Tikhonov regularization. We also investigate the performance of a set of shrinkage based covariance estimators within ISEM. The proposed method is successfully applied on several nonlinear parameter estimation problems for subsurface flow models. The efficiency of the proposed algorithm is demonstrated by the small size of utilized ensembles and in terms of error convergence rates. © 2013 Elsevier Inc.

  13. Flow velocities estimated from chlorine-36 in the South-West Great Artesian Basin, Australia

    International Nuclear Information System (INIS)

    Herczeg, A.L.; Love, A.J.; Sampson, L.; Cresswell, R.G.; Fifield, L.K.

    1999-01-01

    The Great Artesian Basin (GAB) is the largest groundwater basin in the world and is the lifeline for water resources in a large proportion of the arid interior of the Australian continent. Despite its obvious importance, there is a great deal of uncertainty in the estimates of horizontal groundwater flow velocities and recharge rates. We report the first reliable estimates of these sustainability indicators in the south west segment of the GAB. Groundwater was sampled from 23 wells along two transects parallel to the W-E hydraulic gradient for 36 Cl, 14 C, stable isotopes (δ 13 C, δ 18 O, δ 2 H) and major ion chemistry. The groundwater collected was from the undifferentiated Jurassic and Cretaceous (J and K) aquifer. These new data potentially contribute to the resolution of the interpretation of 36 Cl derived ages in a very large slow moving groundwater system and to the overall conceptual understanding of flow systems of the GAB

  14. Parameter estimation of an ARMA model for river flow forecasting using goal programming

    Science.gov (United States)

    Mohammadi, Kourosh; Eslami, H. R.; Kahawita, Rene

    2006-11-01

    SummaryRiver flow forecasting constitutes one of the most important applications in hydrology. Several methods have been developed for this purpose and one of the most famous techniques is the Auto regressive moving average (ARMA) model. In the research reported here, the goal was to minimize the error for a specific season of the year as well as for the complete series. Goal programming (GP) was used to estimate the ARMA model parameters. Shaloo Bridge station on the Karun River with 68 years of observed stream flow data was selected to evaluate the performance of the proposed method. The results when compared with the usual method of maximum likelihood estimation were favorable with respect to the new proposed algorithm.

  15. A pilot study of a simple screening technique for estimation of salivary flow.

    Science.gov (United States)

    Kanehira, Takashi; Yamaguchi, Tomotaka; Takehara, Junji; Kashiwazaki, Haruhiko; Abe, Takae; Morita, Manabu; Asano, Kouzo; Fujii, Yoshinori; Sakamoto, Wataru

    2009-09-01

    The purpose of this study was to develop a simple screening technique for estimation of salivary flow and to test the usefulness of the method for determining decreased salivary flow. A novel assay system comprising 3 spots containing 30 microg starch and 49.6 microg potassium iodide per spot on filter paper and a coloring reagent, based on the color reaction of iodine-starch and theory of paper chromatography, was designed. We investigated the relationship between resting whole salivary rates and the number of colored spots on the filter produced by 41 hospitalized subjects. A significant negative correlation was observed between the number of colored spots and the resting salivary flow rate (n = 41; r = -0.803; P bedridden and disabled elderly people.

  16. Influence of flow stress choice on the plastic collapse estimation of axially cracked steam generator tubes

    International Nuclear Information System (INIS)

    Tonkovic, Zdenko; Skozrit, Ivica; Alfirevic, Ivo

    2008-01-01

    The influence of the choice of flow stress on the plastic collapse estimation of axially cracked steam generator (SG) tubes is considered. The plastic limit and collapse loads of thick-walled tubes with external axial semi-elliptical surface cracks are investigated by three-dimensional non-linear finite element (FE) analyses. The limit pressure solution as a function of the crack depth, length and tube geometry has been developed on the basis of extensive FE limit load analyses employing the elastic-perfectly plastic material behaviour and small strain theory. Unlike the existing solutions, the newly developed analytical approximation of the plastic limit pressure for thick-walled tubes is applicable to a wide range of crack dimensions. Further, the plastic collapse analysis with a real strain-hardening material model and a large deformation theory is performed and an analytical approximation for the estimation of the flow stress is proposed. Numerical results show that the flow stress, defined by some failure assessment diagram (FAD) methods, depends not only on the tube material, but also on the crack geometry. It is shown that the plastic collapse pressure results, in the case of deeper cracks obtained by using the flow stress as the average of the yield stress and the ultimate tensile strength, can become unsafe

  17. Estimation of permafrost thawing rates in a sub-arctic catchment using recession flow analysis

    Directory of Open Access Journals (Sweden)

    S. W. Lyon

    2009-05-01

    Full Text Available Permafrost thawing is likely to change the flow pathways taken by water as it moves through arctic and sub-arctic landscapes. The location and distribution of these pathways directly influence the carbon and other biogeochemical cycling in northern latitude catchments. While permafrost thawing due to climate change has been observed in the arctic and sub-arctic, direct observations of permafrost depth are difficult to perform at scales larger than a local scale. Using recession flow analysis, it may be possible to detect and estimate the rate of permafrost thawing based on a long-term streamflow record. We demonstrate the application of this approach to the sub-arctic Abiskojokken catchment in northern Sweden. Based on recession flow analysis, we estimate that permafrost in this catchment may be thawing at an average rate of about 0.9 cm/yr during the past 90 years. This estimated thawing rate is consistent with direct observations of permafrost thawing rates, ranging from 0.7 to 1.3 cm/yr over the past 30 years in the region.

  18. Estimating construction and demolition debris generation using a materials flow analysis approach.

    Science.gov (United States)

    Cochran, K M; Townsend, T G

    2010-11-01

    The magnitude and composition of a region's construction and demolition (C&D) debris should be understood when developing rules, policies and strategies for managing this segment of the solid waste stream. In the US, several national estimates have been conducted using a weight-per-construction-area approximation; national estimates using alternative procedures such as those used for other segments of the solid waste stream have not been reported for C&D debris. This paper presents an evaluation of a materials flow analysis (MFA) approach for estimating C&D debris generation and composition for a large region (the US). The consumption of construction materials in the US and typical waste factors used for construction materials purchasing were used to estimate the mass of solid waste generated as a result of construction activities. Debris from demolition activities was predicted from various historical construction materials consumption data and estimates of average service lives of the materials. The MFA approach estimated that approximately 610-78 × 10(6)Mg of C&D debris was generated in 2002. This predicted mass exceeds previous estimates using other C&D debris predictive methodologies and reflects the large waste stream that exists. Copyright © 2010 Elsevier Ltd. All rights reserved.

  19. Estimation of daily flow rate of photovoltaic water pumping systems using solar radiation data

    Directory of Open Access Journals (Sweden)

    M. Benghanem

    2018-03-01

    Full Text Available This paper presents a simple model which allows us to contribute in the studies of photovoltaic (PV water pumping systems sizing. The nonlinear relation between water flow rate and solar power has been obtained experimentally in a first step and then used for performance prediction. The model proposed enables us to simulate the water flow rate using solar radiation data for different heads (50 m, 60 m, 70 m and 80 m and for 8S × 3P PV array configuration. The experimental data are obtained with our pumping test facility located at Madinah site (Saudi Arabia. The performances are calculated using the measured solar radiation data of different locations in Saudi Arabia. Knowing the solar radiation data, we have estimated with a good precision the water flow rate Q in five locations (Al-Jouf, Solar Village, AL-Ahsa, Madinah and Gizan in Saudi Arabia. The flow rate Q increases with the increase of pump power for different heads following the nonlinear model proposed. Keywords: Photovoltaic water pumping system, Solar radiation data, Simulation, Flow rate

  20. Recession-based hydrological models for estimating low flows in ungauged catchments in the Himalayas

    Directory of Open Access Journals (Sweden)

    H. G. Rees

    2004-01-01

    Full Text Available The Himalayan region of Nepal and northern India experiences hydrological extremes from monsoonal floods during July to September, when most of the annual precipitation falls, to periods of very low flows during the dry season (December to February. While the monsoon floods cause acute disasters such as loss of human life and property, mudslides and infrastructure damage, the lack of water during the dry season has a chronic impact on the lives of local people. The management of water resources in the region is hampered by relatively sparse hydrometerological networks and consequently, many resource assessments are required in catchments where no measurements exist. A hydrological model for estimating dry season flows in ungauged catchments, based on recession curve behaviour, has been developed to address this problem. Observed flows were fitted to a second order storage model to enable average annual recession behaviour to be examined. Regionalised models were developed, using a calibration set of 26 catchments, to predict three recession curve parameters: the storage constant; the initial recession flow and the start date of the recession. Relationships were identified between: the storage constant and catchment area; the initial recession flow and elevation (acting as a surrogate for rainfall; and the start date of the recession and geographic location. An independent set of 13 catchments was used to evaluate the robustness of the models. The regional models predicted the average volume of water in an annual recession period (1st of October to the 1st of February with an average error of 8%, while mid-January flows were predicted to within ±50% for 79% of the catchments in the data set. Keywords: Himalaya, recession curve, water resources, ungauged catchment, regionalisation, low flows

  1. Development and comparision of techniques for estimating design basis flood flows for nuclear power plants

    International Nuclear Information System (INIS)

    1980-05-01

    Estimation of the design basis flood for Nuclear Power Plants can be carried out using either deterministic or stochastic techniques. Stochastic techniques, while widely used for the solution of a variety of hydrological and other problems, have not been used to date (1980) in connection with the estimation of design basis flood for NPP siting. This study compares the two techniques against one specific river site (Galt on the Grand River, Ontario). The study concludes that both techniques lead to comparable results , but that stochastic techniques have the advantage of extracting maximum information from available data and presenting the results (flood flow) as a continuous function of probability together with estimation of confidence limits. (author)

  2. Validating alternative methodologies to estimate the hydrological regime of temporary streams when flow data are unavailable

    Science.gov (United States)

    Llorens, Pilar; Gallart, Francesc; Latron, Jérôme; Cid, Núria; Rieradevall, Maria; Prat, Narcís

    2016-04-01

    ) were examined. In this case, flow permanence metrics were estimated as the proportion of photographs presenting stream flow. Results indicate that for streams being more than 25% of the time dry, interviews systematically underestimated flow, but the qualitative information given by inhabitants was of great interest to understand river dynamics. On the other hand, the use of aerial photographs gave a good estimation of flow permanence, but the seasonality was conditioned to the capture date of the aerial photographs. For these reasons, we recommend to use both methodologies together.

  3. Recession-based hydrological models for estimating low flows in ungauged catchments in the Himalayas

    Science.gov (United States)

    Rees, H. G.; Holmes, M. G. R.; Young, A. R.; Kansakar, S. R.

    The Himalayan region of Nepal and northern India experiences hydrological extremes from monsoonal floods during July to September, when most of the annual precipitation falls, to periods of very low flows during the dry season (December to February). While the monsoon floods cause acute disasters such as loss of human life and property, mudslides and infrastructure damage, the lack of water during the dry season has a chronic impact on the lives of local people. The management of water resources in the region is hampered by relatively sparse hydrometerological networks and consequently, many resource assessments are required in catchments where no measurements exist. A hydrological model for estimating dry season flows in ungauged catchments, based on recession curve behaviour, has been developed to address this problem. Observed flows were fitted to a second order storage model to enable average annual recession behaviour to be examined. Regionalised models were developed, using a calibration set of 26 catchments, to predict three recession curve parameters: the storage constant; the initial recession flow and the start date of the recession. Relationships were identified between: the storage constant and catchment area; the initial recession flow and elevation (acting as a surrogate for rainfall); and the start date of the recession and geographic location. An independent set of 13 catchments was used to evaluate the robustness of the models. The regional models predicted the average volume of water in an annual recession period (1st of October to the 1st of February) with an average error of 8%, while mid-January flows were predicted to within ±50% for 79% of the catchments in the data set.

  4. Estimation of Leak Flow Rate during Post-LOCA Using Cascaded Fuzzy Neural Networks

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dong Yeong [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Na, Man Gyun [Chosun University, Gwangju (Korea, Republic of)

    2016-10-15

    In this study, important parameters such as the break position, size, and leak flow rate of loss of coolant accidents (LOCAs), provide operators with essential information for recovering the cooling capability of the nuclear reactor core, for preventing the reactor core from melting down, and for managing severe accidents effectively. Leak flow rate should consist of break size, differential pressure, temperature, and so on (where differential pressure means difference between internal and external reactor vessel pressure). The leak flow rate is strongly dependent on the break size and the differential pressure, but the break size is not measured and the integrity of pressure sensors is not assured in severe circumstances. In this paper, a cascaded fuzzy neural network (CFNN) model is appropriately proposed to estimate the leak flow rate out of break, which has a direct impact on the important times (time approaching the core exit temperature that exceeds 1200 .deg. F, core uncover time, reactor vessel failure time, etc.). The CFNN is a data-based model, it requires data to develop and verify itself. Because few actual severe accident data exist, it is essential to obtain the data required in the proposed model using numerical simulations. In this study, a CFNN model was developed to predict the leak flow rate before proceeding to severe LOCAs. The simulations showed that the developed CFNN model accurately predicted the leak flow rate with less error than 0.5%. The CFNN model is much better than FNN model under the same conditions, such as the same fuzzy rules. At the result of comparison, the RMS errors of the CFNN model were reduced by approximately 82 ~ 97% of those of the FNN model.

  5. Estimation of daily flow rate of photovoltaic water pumping systems using solar radiation data

    Science.gov (United States)

    Benghanem, M.; Daffallah, K. O.; Almohammedi, A.

    2018-03-01

    This paper presents a simple model which allows us to contribute in the studies of photovoltaic (PV) water pumping systems sizing. The nonlinear relation between water flow rate and solar power has been obtained experimentally in a first step and then used for performance prediction. The model proposed enables us to simulate the water flow rate using solar radiation data for different heads (50 m, 60 m, 70 m and 80 m) and for 8S × 3P PV array configuration. The experimental data are obtained with our pumping test facility located at Madinah site (Saudi Arabia). The performances are calculated using the measured solar radiation data of different locations in Saudi Arabia. Knowing the solar radiation data, we have estimated with a good precision the water flow rate Q in five locations (Al-Jouf, Solar Village, AL-Ahsa, Madinah and Gizan) in Saudi Arabia. The flow rate Q increases with the increase of pump power for different heads following the nonlinear model proposed.

  6. Two-phase flow patterns recognition and parameters estimation through natural circulation test loop image analysis

    Energy Technology Data Exchange (ETDEWEB)

    Mesquita, R.N.; Libardi, R.M.P.; Masotti, P.H.F.; Sabundjian, G.; Andrade, D.A.; Umbehaun, P.E.; Torres, W.M.; Conti, T.N.; Macedo, L.A. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Nuclear Engineering Center], e-mail: rnavarro@ipen.br

    2009-07-01

    Visualization of natural circulation test loop cycles is used to study two-phase flow patterns associated with phase transients and static instabilities of flow. Experimental studies on natural circulation flow were originally related to accidents and transient simulations relative to nuclear reactor systems with light water refrigeration. In this regime, fluid circulation is mainly caused by a driving force ('thermal head') which arises from density differences due to temperature gradient. Natural circulation phenomenon has been important to provide residual heat removal in cases of 'loss of pump power' or plant shutdown in nuclear power plant accidents. The new generation of compact nuclear reactors includes natural circulation of their refrigerant fluid as a security mechanism in their projects. Two-phase flow patterns have been studied for many decades, and the related instabilities have been object of special attention recently. Experimental facility is an all glass-made cylindrical tubes loop which contains about twelve demineralized water liters, a heat source by an electrical resistor immersion heater controlled by a Variac, and a helicoidal heat exchanger working as cold source. Data is obtained through thermo-pairs distributed over the loop and CCD cameras. Artificial intelligence based algorithms are used to improve (bubble) border detection and patterns recognition, in order to estimate and characterize, phase transitions patterns and correlate them with the periodic static instability (chugging) cycle observed in this circuit. Most of initial results show good agreement with previous numerical studies in this same facility. (author)

  7. Two-phase flow patterns recognition and parameters estimation through natural circulation test loop image analysis

    International Nuclear Information System (INIS)

    Mesquita, R.N.; Libardi, R.M.P.; Masotti, P.H.F.; Sabundjian, G.; Andrade, D.A.; Umbehaun, P.E.; Torres, W.M.; Conti, T.N.; Macedo, L.A.

    2009-01-01

    Visualization of natural circulation test loop cycles is used to study two-phase flow patterns associated with phase transients and static instabilities of flow. Experimental studies on natural circulation flow were originally related to accidents and transient simulations relative to nuclear reactor systems with light water refrigeration. In this regime, fluid circulation is mainly caused by a driving force ('thermal head') which arises from density differences due to temperature gradient. Natural circulation phenomenon has been important to provide residual heat removal in cases of 'loss of pump power' or plant shutdown in nuclear power plant accidents. The new generation of compact nuclear reactors includes natural circulation of their refrigerant fluid as a security mechanism in their projects. Two-phase flow patterns have been studied for many decades, and the related instabilities have been object of special attention recently. Experimental facility is an all glass-made cylindrical tubes loop which contains about twelve demineralized water liters, a heat source by an electrical resistor immersion heater controlled by a Variac, and a helicoidal heat exchanger working as cold source. Data is obtained through thermo-pairs distributed over the loop and CCD cameras. Artificial intelligence based algorithms are used to improve (bubble) border detection and patterns recognition, in order to estimate and characterize, phase transitions patterns and correlate them with the periodic static instability (chugging) cycle observed in this circuit. Most of initial results show good agreement with previous numerical studies in this same facility. (author)

  8. Wavelet denoising method; application to the flow rate estimation for water level control

    International Nuclear Information System (INIS)

    Park, Gee Young; Park, Jin Ho; Lee, Jung Han; Kim, Bong Soo; Seong, Poong Hyun

    2003-01-01

    The wavelet transform decomposes a signal into time- and frequency-domain signals and it is well known that a noise-corrupted signal could be reconstructed or estimated when a proper denoising method is involved in the wavelet transform. Among the wavelet denoising methods proposed up to now, the wavelets by Mallat and Zhong can reconstruct best the pure transient signal from a highly corrupted signal. But there has been no systematic way of discriminating the original signal from the noise in a dyadic wavelet transform. In this paper, a systematic method is proposed for noise discrimination, which could be implemented easily into a digital system. For demonstrating the potential role of the wavelet denoising method in the nuclear field, this method is applied to the steam or feedwater flow rate estimation of the secondary loop. And the configuration of the S/G water level control system is proposed for incorporating the wavelet denoising method in estimating the flow rate value at low operating powers

  9. Using Mathematical Modeling Methods for Estimating Entrance Flow Heterogeneity Impact on Aviation GTE Parameters and Performances

    Directory of Open Access Journals (Sweden)

    Yu. A. Ezrokhi

    2017-01-01

    Full Text Available The paper considers methodological approaches to the mathematical models (MM of various levels, dedicated to estimate an impact of the entrance flow heterogeneity on the main parameters and performances of the aviation GTE and it units. By an example of calculation of a twin-shaft turbofan engine in cruiser mode, demonstrates engineering mathematical model capabilities to define the impact of the total pressure field distortion on engine trust and air flow parameters, and also gas dynamic stability margin of the both compressors.It is shown that the presented first level mathematical model allows us to estimate sufficiently the impact of entrance total pressure heterogeneity on the engine parameters. Here reliability of calculations is proved to be true by their comparison with the results, obtained owing to well fulfilled 2D & 3D mathematical models of the engine, which have been repeatedly identified by the results of experiments.It is shown that received results including those on decreasing values of stability margin of both compressors can be used for tentative estimates when choosing a desirable stability margin, providing steady operation of compressors and engine in an entire range of its operating modes. Carrying out a definitive testing calculation using the specialized engine MM of a higher level will not only confirm the results obtained, but also reduce their expected error with regard to the real values reached as a result of tests.

  10. Pinsker estimators for local helioseismology: inversion of travel times for mass-conserving flows

    International Nuclear Information System (INIS)

    Fournier, Damien; Holzke, Martin; Hohage, Thorsten; Gizon, Laurent

    2016-01-01

    A major goal of helioseismology is the three-dimensional reconstruction of the three velocity components of convective flows in the solar interior from sets of wave travel-time measurements. For small amplitude flows, the forward problem is described in good approximation by a large system of convolution equations. The input observations are highly noisy random vectors with a known dense covariance matrix. This leads to a large statistical linear inverse problem. Whereas for deterministic linear inverse problems several computationally efficient minimax optimal regularization methods exist, only one minimax-optimal linear estimator exists for statistical linear inverse problems: the Pinsker estimator. However, it is often computationally inefficient because it requires a singular value decomposition of the forward operator or it is not applicable because of an unknown noise covariance matrix, so it is rarely used for real-world problems. These limitations do not apply in helioseismology. We present a simplified proof of the optimality properties of the Pinsker estimator and show that it yields significantly better reconstructions than traditional inversion methods used in helioseismology, i.e. regularized least squares (Tikhonov regularization) and SOLA (approximate inverse) methods. Moreover, we discuss the incorporation of the mass conservation constraint in the Pinsker scheme using staggered grids. With this improvement we can reconstruct not only horizontal, but also vertical velocity components that are much smaller in amplitude. (paper)

  11. A hybrid method of estimating pulsating flow parameters in the space-time domain

    Science.gov (United States)

    Pałczyński, Tomasz

    2017-05-01

    This paper presents a method for estimating pulsating flow parameters in partially open pipes, such as pipelines, internal combustion engine inlets, exhaust pipes and piston compressors. The procedure is based on the method of characteristics, and employs a combination of measurements and simulations. An experimental test rig is described, which enables pressure, temperature and mass flow rate to be measured within a defined cross section. The second part of the paper discusses the main assumptions of a simulation algorithm elaborated in the Matlab/Simulink environment. The simulation results are shown as 3D plots in the space-time domain, and compared with proposed models of phenomena relating to wave propagation, boundary conditions, acoustics and fluid mechanics. The simulation results are finally compared with acoustic phenomena, with an emphasis on the identification of resonant frequencies.

  12. Nyretransplantation med levende donor

    DEFF Research Database (Denmark)

    Kamper, A L; Løkkegaard, H; Rasmussen, F

    2000-01-01

    In recent years transplantation from living donors has accounted for 25-30% of all kidney transplants in Denmark corresponding to 40-45 per year. Most of these living donors are parents or siblings, although internationally an increasing number are unrelated donors. Donor nephrectomy is associate...... in cadaver transplantation. The ethical and psychological aspects related to transplantation from a living donor are complex and need to be carefully evaluated when this treatment is offered to the patients....

  13. Online state of charge and model parameter co-estimation based on a novel multi-timescale estimator for vanadium redox flow battery

    International Nuclear Information System (INIS)

    Wei, Zhongbao; Lim, Tuti Mariana; Skyllas-Kazacos, Maria; Wai, Nyunt; Tseng, King Jet

    2016-01-01

    Highlights: • Battery model parameters and SOC co-estimation is investigated. • The model parameters and OCV are decoupled and estimated independently. • Multiple timescales are adopted to improve precision and stability. • SOC is online estimated without using the open-circuit cell. • The method is robust to aging levels, flow rates, and battery chemistries. - Abstract: A key function of battery management system (BMS) is to provide accurate information of the state of charge (SOC) in real time, and this depends directly on the precise model parameterization. In this paper, a novel multi-timescale estimator is proposed to estimate the model parameters and SOC for vanadium redox flow battery (VRB) in real time. The model parameters and OCV are decoupled and estimated independently, effectively avoiding the possibility of cross interference between them. The analysis of model sensitivity, stability, and precision suggests the necessity of adopting different timescales for each estimator independently. Experiments are conducted to assess the performance of the proposed method. Results reveal that the model parameters are online adapted accurately thus the periodical calibration on them can be avoided. The online estimated terminal voltage and SOC are both benchmarked with the reference values. The proposed multi-timescale estimator has the merits of fast convergence, high precision, and good robustness against the initialization uncertainty, aging states, flow rates, and also battery chemistries.

  14. Estimating the Natural Flow Regime of Rivers With Long-Standing Development: The Northern Branch of the Rio Grande

    Science.gov (United States)

    Blythe, Todd L.; Schmidt, John C.

    2018-02-01

    An estimate of a river's natural flow regime is useful for water resource planning and ecosystem rehabilitation by providing insight into the predisturbance form and function of a river. The natural flow regime of most rivers has been perturbed by development during the 20th century and in some cases, before stream gaging began. The temporal resolution of natural flows estimated using traditional methods is typically not sufficient to evaluate cues that drive native ecosystem function. Additionally, these traditional methods are watershed specific and require large amounts of data to produce accurate results. We present a mass balance method that estimates natural flows at daily time step resolution for the northern branch of the Rio Grande, upstream from the Rio Conchos, that relies only on easily obtained streamflow data. Using an analytical change point method, we identified periods of the measured flow regime during the 20th century for comparison with the estimated natural flows. Our results highlight the significant deviation from natural conditions that occurred during the 20th century. The total annual flow of the northern branch is 95% lower than it would be in the absence of human use. The current 2 year flood has decreased by more than 60%, is shorter in duration, and peaks later in the year. When compared to unregulated flows estimated using traditional mass balance accounting methods, our approach provides similar results.

  15. Non-invasive estimation of pulsatile flow and differential pressure in an implantable rotary blood pump for heart failure patients

    International Nuclear Information System (INIS)

    AlOmari, A H; Savkin, A V; Karantonis, D M; Lim, E; Lovell, N H

    2009-01-01

    We propose dynamical models for pulsatile flow and head estimation in an implantable rotary blood pump. Pulsatile flow and head data were obtained using a circulatory mock loop where fluid solutions with different values of viscosities were used as a blood analogue with varying haematocrit (HCT). Noninvasive measurements of power and pump speed were used with HCT values as inputs to the flow model while the estimated flow was used with the speed as inputs to a head estimation model. Linear regression analysis between estimated and measured flows obtained from a mock loop resulted in a highly significant correlation (R 2 = 0.982) and a mean absolute error (e) of 0.323 L min −1 , while for head, R 2 = 0.933 and e = 7.682 mmHg were obtained. R 2 = 0.849 and e = 0.584 L min −1 were obtained when the same model derived in the mock loop was used for flow estimation in ex vivo porcine data (N = 6). Furthermore, in the steady state, the solution of the presented flow model can be described by a previously designed and verified static model. The models developed herein will play a vital role in developing a robust control system of the pump flow coping with changing physiological demands

  16. Air mass flow estimation in turbocharged diesel engines from in-cylinder pressure measurement

    Energy Technology Data Exchange (ETDEWEB)

    Desantes, J.M.; Galindo, J.; Guardiola, C.; Dolz, V. [CMT - Motores Termicos, Universidad Politecnica de Valencia (Spain)

    2010-01-15

    Air mass flow determination is needed for the control of current internal combustion engines. Current methods are based on specific sensors (as hot wire anemometers) or indirect estimation through manifold pressure. With the availability of cylinder pressure sensors for engine control, methods based on them can be used for replacing or complementing standard methods. Present paper uses in cylinder pressure increase during the intake stroke for inferring the trapped air mass. The method is validated on two different turbocharged diesel engines and compared with the standard methods. (author)

  17. Estimating annual high-flow statistics and monthly and seasonal low-flow statistics for ungaged sites on streams in Alaska and conterminous basins in Canada

    Science.gov (United States)

    Wiley, Jeffrey B.; Curran, Janet H.

    2003-01-01

    Methods for estimating daily mean flow-duration statistics for seven regions in Alaska and low-flow frequencies for one region, southeastern Alaska, were developed from daily mean discharges for streamflow-gaging stations in Alaska and conterminous basins in Canada. The 15-, 10-, 9-, 8-, 7-, 6-, 5-, 4-, 3-, 2-, and 1-percent duration flows were computed for the October-through-September water year for 222 stations in Alaska and conterminous basins in Canada. The 98-, 95-, 90-, 85-, 80-, 70-, 60-, and 50-percent duration flows were computed for the individual months of July, August, and September for 226 stations in Alaska and conterminous basins in Canada. The 98-, 95-, 90-, 85-, 80-, 70-, 60-, and 50-percent duration flows were computed for the season July-through-September for 65 stations in southeastern Alaska. The 7-day, 10-year and 7-day, 2-year low-flow frequencies for the season July-through-September were computed for 65 stations for most of southeastern Alaska. Low-flow analyses were limited to particular months or seasons in order to omit winter low flows, when ice effects reduce the quality of the records and validity of statistical assumptions. Regression equations for estimating the selected high-flow and low-flow statistics for the selected months and seasons for ungaged sites were developed from an ordinary-least-squares regression model using basin characteristics as independent variables. Drainage area and precipitation were significant explanatory variables for high flows, and drainage area, precipitation, mean basin elevation, and area of glaciers were significant explanatory variables for low flows. The estimating equations can be used at ungaged sites in Alaska and conterminous basins in Canada where streamflow regulation, streamflow diversion, urbanization, and natural damming and releasing of water do not affect the streamflow data for the given month or season. Standard errors of estimate ranged from 15 to 56 percent for high-duration flow

  18. An extended continuous estimation of distribution algorithm for solving the permutation flow-shop scheduling problem

    Science.gov (United States)

    Shao, Zhongshi; Pi, Dechang; Shao, Weishi

    2017-11-01

    This article proposes an extended continuous estimation of distribution algorithm (ECEDA) to solve the permutation flow-shop scheduling problem (PFSP). In ECEDA, to make a continuous estimation of distribution algorithm (EDA) suitable for the PFSP, the largest order value rule is applied to convert continuous vectors to discrete job permutations. A probabilistic model based on a mixed Gaussian and Cauchy distribution is built to maintain the exploration ability of the EDA. Two effective local search methods, i.e. revolver-based variable neighbourhood search and Hénon chaotic-based local search, are designed and incorporated into the EDA to enhance the local exploitation. The parameters of the proposed ECEDA are calibrated by means of a design of experiments approach. Simulation results and comparisons based on some benchmark instances show the efficiency of the proposed algorithm for solving the PFSP.

  19. A Flow Cytometry Protocol to Estimate DNA Content in the Yellowtail Tetra Astyanax altiparanae

    Directory of Open Access Journals (Sweden)

    Pedro L. P. Xavier

    2017-09-01

    Full Text Available The production of triploid yellowtail tetra Astyanax altiparanae is a key factor to obtain permanently sterile individuals by chromosome set manipulation. Flow cytometric analysis is the main tool for confirmation of the resultant triploids individuals, but very few protocols are specific for A. altiparanae species. The current study has developed a protocol to estimate DNA content in this species. Furthermore, a protocol for long-term storage of dorsal fins used for flow cytometry analysis was established. The combination of five solutions with three detergents (Nonidet P-40 Substitute, Tween 20, and Triton X-100 at 0.1, 0.2, and 0.4% concentration was evaluated. Using the best solution from this first experiment, the addition of trypsin (0.125, 0.25, and 0.5% and sucrose (74 mM and the effects of increased concentrations of the detergents at 0.6 and 1.2% concentration were also evaluated. After adjustment of the protocol for flow cytometry, preservation of somatic tissue or isolated nuclei was also evaluated by freezing (at −20°C and fixation in saturated NaCl solution, acetic methanol (1:3, ethanol, and formalin at 10% for 30 or 60 days of storage at 25°C. Flow cytometry analysis in yellowtail tetra species was optimized using the following conditions: lysis solution: 9.53 mM MgCl2.7H20; 47.67 mM KCl; 15 mM Tris; 74 mM sucrose, 0.6% Triton X-100, pH 8.0; staining solution: Dulbecco's PBS with DAPI 1 μg mL−1; preservation procedure: somatic cells (dorsal fin samples frozen at −20°C. Using this protocol, samples may be stored up to 60 days with good accuracy for flow cytometry analysis.

  20. Review of flow rate estimates of the Deepwater Horizon oil spill

    Science.gov (United States)

    McNutt, Marcia K.; Camilli, Rich; Crone, Timothy J.; Guthrie, George D.; Hsieh, Paul A.; Ryerson, Thomas B.; Savas, Omer; Shaffer, Frank

    2012-01-01

    The unprecedented nature of the Deepwater Horizon oil spill required the application of research methods to estimate the rate at which oil was escaping from the well in the deep sea, its disposition after it entered the ocean, and total reservoir depletion. Here, we review what advances were made in scientific understanding of quantification of flow rates during deep sea oil well blowouts. We assess the degree to which a consensus was reached on the flow rate of the well by comparing in situ observations of the leaking well with a time-dependent flow rate model derived from pressure readings taken after the Macondo well was shut in for the well integrity test. Model simulations also proved valuable for predicting the effect of partial deployment of the blowout preventer rams on flow rate. Taken together, the scientific analyses support flow rates in the range of ~50,000–70,000 barrels/d, perhaps modestly decreasing over the duration of the oil spill, for a total release of ~5.0 million barrels of oil, not accounting for BP's collection effort. By quantifying the amount of oil at different locations (wellhead, ocean surface, and atmosphere), we conclude that just over 2 million barrels of oil (after accounting for containment) and all of the released methane remained in the deep sea. By better understanding the fate of the hydrocarbons, the total discharge can be partitioned into separate components that pose threats to deep sea vs. coastal ecosystems, allowing responders in future events to scale their actions accordingly.

  1. A tool to estimate bar patterns and flow conditions in estuaries when limited data is available

    Science.gov (United States)

    Leuven, J.; Verhoeve, S.; Bruijns, A. J.; Selakovic, S.; van Dijk, W. M.; Kleinhans, M. G.

    2017-12-01

    The effects of human interventions, natural evolution of estuaries and rising sea-level on food security and flood safety are largely unknown. In addition, ecologists require quantified habitat area to study future evolution of estuaries, but they lack predictive capability of bathymetry and hydrodynamics. For example, crucial input required for ecological models are values of intertidal area, inundation time, peak flow velocities and salinity. While numerical models can reproduce these spatial patterns, their computational times are long and for each case a new model must be developed. Therefore, we developed a comprehensive set of relations that accurately predict the hydrodynamics and the patterns of channels and bars, using a combination of the empirical relations derived from approximately 50 estuaries and theory for bars and estuaries. The first step is to predict local tidal prisms, which is the tidal prism that flows through a given cross-section. Second, the channel geometry is predicted from tidal prism and hydraulic geometry relations. Subsequently, typical flow velocities can be estimated from the channel geometry and tidal prism. Then, an ideal estuary shape is fitted to the measured planform: the deviation from the ideal shape, which is defined as the excess width, gives a measure of the locations where tidal bars form and their summed width (Leuven et al., 2017). From excess width, typical hypsometries can be predicted per cross-section. In the last step, flow velocities are calculated for the full range of occurring depths and salinity is calculated based on the estuary shape. Here, we will present a prototype tool that predicts equilibrium bar patterns and typical flow conditions. The tool is easy to use because the only input required is the estuary outline and tidal amplitude. Therefore it can be used by policy makers and researchers from multiple disciplines, such as ecologists, geologists and hydrologists, for example for paleogeographic

  2. Review of flow rate estimates of the Deepwater Horizon oil spill.

    Science.gov (United States)

    McNutt, Marcia K; Camilli, Rich; Crone, Timothy J; Guthrie, George D; Hsieh, Paul A; Ryerson, Thomas B; Savas, Omer; Shaffer, Frank

    2012-12-11

    The unprecedented nature of the Deepwater Horizon oil spill required the application of research methods to estimate the rate at which oil was escaping from the well in the deep sea, its disposition after it entered the ocean, and total reservoir depletion. Here, we review what advances were made in scientific understanding of quantification of flow rates during deep sea oil well blowouts. We assess the degree to which a consensus was reached on the flow rate of the well by comparing in situ observations of the leaking well with a time-dependent flow rate model derived from pressure readings taken after the Macondo well was shut in for the well integrity test. Model simulations also proved valuable for predicting the effect of partial deployment of the blowout preventer rams on flow rate. Taken together, the scientific analyses support flow rates in the range of ∼50,000-70,000 barrels/d, perhaps modestly decreasing over the duration of the oil spill, for a total release of ∼5.0 million barrels of oil, not accounting for BP's collection effort. By quantifying the amount of oil at different locations (wellhead, ocean surface, and atmosphere), we conclude that just over 2 million barrels of oil (after accounting for containment) and all of the released methane remained in the deep sea. By better understanding the fate of the hydrocarbons, the total discharge can be partitioned into separate components that pose threats to deep sea vs. coastal ecosystems, allowing responders in future events to scale their actions accordingly.

  3. A thermal analysis computer programme package for the estimation of KANUPP coolant channel flows and outlet header temperature distribution

    International Nuclear Information System (INIS)

    Siddiqui, M.S.

    1992-06-01

    COFTAN is a computer code for actual estimation of flows and temperatures in the coolant channels of a pressure tube heavy water reactor. The code is being used for Candu type reactor with coolant flowing 208 channels. The simulation model first performs the detailed calculation of flux and power distribution based on two groups diffusion theory treatment on a three dimensional mesh and then channel powers, resulting from the summation of eleven bundle powers in each of the 208 channels, are employed to make actual estimation of coolant flows using channel powers and channel outlet temperature monitored by digital computers. The code by using the design flows in individual channels and applying a correction factor based on control room monitored flows in eight selected channels, can also provide a reserve computational tool of estimating individual channel outlet temperatures, thus providing an alternate arrangements for checking Rads performance. 42 figs. (Orig./A.B.)

  4. Estimation of the annual flow and stock of marine debris in South Korea for management purposes.

    Science.gov (United States)

    Jang, Yong Chang; Lee, Jongmyoung; Hong, Sunwook; Mok, Jin Yong; Kim, Kyoung Shin; Lee, Yun Jeong; Choi, Hyun-Woo; Kang, Hongmook; Lee, Sukhui

    2014-09-15

    The annual flow and stock of marine debris in the Sea of Korea was estimated by summarizing previous survey results and integrating them with other relevant information to underpin the national marine debris management plan. The annual inflow of marine debris was estimated to be 91,195 tons [32,825 tons (36% of the total) from sources on land and 58,370 tons (64%) from ocean sources]. As of the end of 2012, the total stock of marine debris on all South Korean coasts (12,029 tons), the seabed (137,761 tons), and in the water column (2451 tons) was estimated to be 152,241 tons. In 2012, 42,595 tons of marine debris was collected from coasts, seabeds, and the water column. This is a very rare case study that estimated the amount of marine debris at a national level, the results of which provide essential information for the development of efficient marine debris management policies. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Estimating the State of Aerodynamic Flows in the Presence of Modeling Errors

    Science.gov (United States)

    da Silva, Andre F. C.; Colonius, Tim

    2017-11-01

    The ensemble Kalman filter (EnKF) has been proven to be successful in fields such as meteorology, in which high-dimensional nonlinear systems render classical estimation techniques impractical. When the model used to forecast state evolution misrepresents important aspects of the true dynamics, estimator performance may degrade. In this work, parametrization and state augmentation are used to track misspecified boundary conditions (e.g., free stream perturbations). The resolution error is modeled as a Gaussian-distributed random variable with the mean (bias) and variance to be determined. The dynamics of the flow past a NACA 0009 airfoil at high angles of attack and moderate Reynolds number is represented by a Navier-Stokes equations solver with immersed boundaries capabilities. The pressure distribution on the airfoil or the velocity field in the wake, both randomized by synthetic noise, are sampled as measurement data and incorporated into the estimated state and bias following Kalman's analysis scheme. Insights about how to specify the modeling error covariance matrix and its impact on the estimator performance are conveyed. This work has been supported in part by a Grant from AFOSR (FA9550-14-1-0328) with Dr. Douglas Smith as program manager, and by a Science without Borders scholarship from the Ministry of Education of Brazil (Capes Foundation - BEX 12966/13-4).

  6. The impact of interpreted flow regimes during constant head injection tests on the estimated transmissivity from injection tests and difference flow logging

    Energy Technology Data Exchange (ETDEWEB)

    Hjerne, Calle; Ludvigsson, Jan-Erik; Harrstroem, Johan [Geosigma AB, Uppsala (Sweden)

    2013-04-15

    A large number of constant head injection tests were carried out in the site investigation at Forsmark using the Pipe String System, PSS3. During the original evaluation of the tests the dominating transient flow regimes during both the injection and recovery period were interpreted together with estimation of hydraulic parameters. The flow regimes represent different flow and boundary conditions during the tests. Different boreholes or borehole intervals may display different distributions of flow regimes. In some boreholes good agreement was obtained between the results of the injection tests and difference flow logging with Posiva flow log (PFL) but in other boreholes significant discrepancies were found. The main objective of this project is to study the correlation between transient flow regimes from the injection tests and other borehole features such as transmissivity, depth, geology, fracturing etc. Another subject studied is whether observed discrepancies between estimated transmissivity from difference flow logging and injection tests can be correlated to interpreted flow regimes. Finally, a detailed comparison between transient and stationary evaluation of transmissivity from the injection tests in relation to estimated transmissivity from PFL tests in corresponding sections is made. Results from previous injection tests in 5 m sections in boreholes KFM04, KFM08A and KFM10A were used. Only injection tests above the (test-specific) measurement limit regarding flow rate are included in the analyses. For all of these tests transient flow regimes were interpreted. In addition, results from difference flow logging in the corresponding 5 m test sections were used. Finally, geological data of fractures together with rock and fracture zone properties have been used in the correlations. Flow regimes interpreted from the injection period of the tests are generally used in the correlations but deviations between the interpreted flow regimes from the injection and

  7. Hour-Glass Neural Network Based Daily Money Flow Estimation for Automatic Teller Machines

    Science.gov (United States)

    Karungaru, Stephen; Akashi, Takuya; Nakano, Miyoko; Fukumi, Minoru

    Monetary transactions using Automated Teller Machines (ATMs) have become a normal part of our daily lives. At ATMs, one can withdraw, send or debit money and even update passbooks among many other possible functions. ATMs are turning the banking sector into a ubiquitous service. However, while the advantages for the ATM users (financial institution customers) are many, the financial institution side faces an uphill task in management and maintaining the cash flow in the ATMs. On one hand, too much money in a rarely used ATM is wasteful, while on the other, insufficient amounts would adversely affect the customers and may result in a lost business opportunity for the financial institution. Therefore, in this paper, we propose a daily cash flow estimation system using neural networks that enables better daily forecasting of the money required at the ATMs. The neural network used in this work is a five layered hour glass shaped structure that achieves fast learning, even for the time series data for which seasonality and trend feature extraction is difficult. Feature extraction is carried out using the Akamatsu Integral and Differential transforms. This work achieves an average estimation accuracy of 92.6%.

  8. Enhancement of automated blood flow estimates (ENABLE) from arterial spin-labeled MRI.

    Science.gov (United States)

    Shirzadi, Zahra; Stefanovic, Bojana; Chappell, Michael A; Ramirez, Joel; Schwindt, Graeme; Masellis, Mario; Black, Sandra E; MacIntosh, Bradley J

    2018-03-01

    To validate a multiparametric automated algorithm-ENhancement of Automated Blood fLow Estimates (ENABLE)-that identifies useful and poor arterial spin-labeled (ASL) difference images in multiple postlabeling delay (PLD) acquisitions and thereby improve clinical ASL. ENABLE is a sort/check algorithm that uses a linear combination of ASL quality features. ENABLE uses simulations to determine quality weighting factors based on an unconstrained nonlinear optimization. We acquired a set of 6-PLD ASL images with 1.5T or 3.0T systems among 98 healthy elderly and adults with mild cognitive impairment or dementia. We contrasted signal-to-noise ratio (SNR) of cerebral blood flow (CBF) images obtained with ENABLE vs. conventional ASL analysis. In a subgroup, we validated our CBF estimates with single-photon emission computed tomography (SPECT) CBF images. ENABLE produced significantly increased SNR compared to a conventional ASL analysis (Wilcoxon signed-rank test, P Wilcoxon signed-rank test, P < 0.0001) and this similarity was strongly related to ASL SNR (t = 24, P < 0.0001). These findings suggest that ENABLE improves CBF image quality from multiple PLD ASL in dementia cohorts at either 1.5T or 3.0T, achieved by multiparametric quality features that guided postprocessing of dementia ASL. 2 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2018;47:647-655. © 2017 International Society for Magnetic Resonance in Medicine.

  9. Estimation of brachial artery volume flow by duplex ultrasound imaging predicts dialysis access maturation.

    Science.gov (United States)

    Ko, Sae Hee; Bandyk, Dennis F; Hodgkiss-Harlow, Kelley D; Barleben, Andrew; Lane, John

    2015-06-01

    This study validated duplex ultrasound measurement of brachial artery volume flow (VF) as predictor of dialysis access flow maturation and successful hemodialysis. Duplex ultrasound was used to image upper extremity dialysis access anatomy and estimate access VF within 1 to 2 weeks of the procedure. Correlation of brachial artery VF with dialysis access conduit VF was performed using a standardized duplex testing protocol in 75 patients. The hemodynamic data were used to develop brachial artery flow velocity criteria (peak systolic velocity and end-diastolic velocity) predictive of three VF categories: low (800 mL/min). Brachial artery VF was then measured in 148 patients after a primary (n = 86) or revised (n = 62) upper extremity dialysis access procedure, and the VF category correlated with access maturation or need for revision before hemodialysis usage. Access maturation was conferred when brachial artery VF was >600 mL/min and conduit imaging indicated successful cannulation based on anatomic criteria of conduit diameter >5 mm and skin depth 800 mL/min was predicted when the brachial artery lumen diameter was >4.5 mm, peak systolic velocity was >150 cm/s, and the diastolic-to-systolic velocity ratio was >0.4. Brachial artery velocity spectra indicating VF 800 mL/min. Duplex testing to estimate brachial artery VF and assess the conduit for ease of cannulation can be performed in 5 minutes during the initial postoperative vascular clinic evaluation. Estimation of brachial artery VF using the duplex ultrasound, termed the "Fast, 5-min Dialysis Duplex Scan," facilitates patient evaluation after new or revised upper extremity dialysis access procedures. Brachial artery VF correlates with access VF measurements and has the advantage of being easier to perform and applicable for forearm and also arm dialysis access. When brachial artery velocity spectra criteria confirm a VF >800 mL/min, flow maturation and successful hemodialysis are predicted if anatomic criteria

  10. Estimated flows of gases and carbon within CEEF ecosystem composed of human, crops and goats

    Science.gov (United States)

    Tako, Y.; Komatsubara, O.; Honda, G.; Arai, R.; Nitta, K.

    The Closed Ecology Experiment Facilities (CEEF) can be used as a test bed for Controlled Ecological Life Support Systems (CELSS), because technologies developed for the CEEF system facilitate self-sufficient material circulation necessary for long term missions such as Lunar and Mars exploration. In the experiment conducted under closed condition in FY2003, rice and soybeans were cultivated sequentially in two chambers and a chamber, each having a cultivation area of 30 m2 and floor area of 43 m2, inside the Plantation Module with artificial lighting of the CEEF. In the chamber having a cultivation area of 60 m2 and floor area of 65 m2, inside the Plantation Module with natural and artificial lighting, peanuts and safflowers were also cultivated. Stable transplant (or seeding) and harvest of each crop were maintained during a month. Flows of CO2, O2 and carbon to and from the crops were analyzed during the stable cultivation period. Simulated works and stay in the CEEF lasting five days were conducted two times under ventilating condition in FY2003. Gas exchange of human was estimated using heart rate data collected during the experiments and correlation between gas exchange rate and heart rate. Gas exchange rate and carbon balance of female goats were determined using an open-flow measurement system with a gastight chamber. From these results, flows of gases and carbon in the CEEF were discussed.

  11. Estimation of Engine Intake Air Mass Flow using a generic Speed-Density method

    Directory of Open Access Journals (Sweden)

    Vojtíšek Michal

    2014-10-01

    Full Text Available Measurement of real driving emissions (RDE from internal combustion engines under real-world operation using portable, onboard monitoring systems (PEMS is becoming an increasingly important tool aiding the assessment of the effects of new fuels and technologies on environment and human health. The knowledge of exhaust flow is one of the prerequisites for successful RDE measurement with PEMS. One of the simplest approaches for estimating the exhaust flow from virtually any engine is its computation from the intake air flow, which is calculated from measured engine rpm and intake manifold charge pressure and temperature using a generic speed-density algorithm, applicable to most contemporary four-cycle engines. In this work, a generic speed-density algorithm was compared against several reference methods on representative European production engines - a gasoline port-injected automobile engine, two turbocharged diesel automobile engines, and a heavy-duty turbocharged diesel engine. The overall results suggest that the uncertainty of the generic speed-density method is on the order of 10% throughout most of the engine operating range, but increasing to tens of percent where high-volume exhaust gas recirculation is used. For non-EGR engines, such uncertainty is acceptable for many simpler and screening measurements, and may be, where desired, reduced by engine-specific calibration.

  12. THE ASSESSMENT OF GEOTHERMAL POTENTIAL OF TURKEY BY MEANS OF HEAT FLOW ESTIMATION

    Directory of Open Access Journals (Sweden)

    UĞUR AKIN

    2014-12-01

    Full Text Available In this study, the heat flow distribution of Turkey was investigated in the interest ofexploring new geothermal fields in addition to known ones. For this purposes, thegeothermal gradient was estimated from the Curie point depth map obtained from airbornemagnetic data by means of power spectrum method. By multiplying geothermal gradientwith thermal conductivity values, the heat flow map of Turkey was obtained. The averagevalue in the heat flow map of Turkey was determined as 74 mW/m2. It points out existenceof resources of geothermal energy larger than the average of the world resources. in termsof geothermal potential, the most significant region of Turkey is the Aydin and itssurrounding with a value exceeding 200 mW/m2. On the contrary, the value decreasesbelow 30 mW/m2in the region bordered by Aksaray, Niğde, Karaman and Konya. Thenecessity of conducting a detailed additional studies for East Black sea, East and SoutheastAnatolia is also revealed

  13. Impact of using different blood donor subpopulations and models on the estimation of transfusion transmission residual risk of human immunodeficiency virus, hepatitis B virus, and hepatitis C virus in Zimbabwe.

    Science.gov (United States)

    Mapako, Tonderai; Janssen, Mart P; Mvere, David A; Emmanuel, Jean C; Rusakaniko, Simbarashe; Postma, Maarten J; van Hulst, Marinus

    2016-06-01

    Various models for estimating the residual risk (RR) of transmission of infections by blood transfusion have been published mainly based on data from high-income countries. However, to obtain the data required for such an assessment remains challenging for most developing settings. The National Blood Service Zimbabwe (NBSZ) adapted a published incidence-window period (IWP) model, which has less demanding data requirements. In this study we assess the impact of various definitions of blood donor subpopulations and models on RR estimates. We compared the outcomes of two published models and an adapted NBSZ model. The Schreiber IWP model (Model 1), an amended version (Model 2), and an adapted NBSZ model (Model 3) were applied. Variably the three models include prevalence, incidence, preseroconversion intervals, mean lifetime risk, and person-years at risk. Annual mean RR estimates and 95% confidence intervals for each of the three models for human immunodeficiency virus (HIV), hepatitis B virus (HBV), and hepatitis C virus (HCV) were determined using NBSZ blood donor data from 2002 through 2011. The annual mean RR estimates for Models 1 through 3 were 1 in 6542, 5805, and 6418, respectively for HIV; 1 in 1978, 2027, and 1628 for HBV; and 1 in 9588, 15,126, and 7750, for HCV. The adapted NBSZ model provided comparable results to the published methods and these highlight the high occurrence of HBV in Zimbabwe. The adapted NBSZ model could be used as an alternative to estimate RRs when in settings where two repeat donations are not available. © 2016 AABB.

  14. Estimating evapotranspiration and groundwater flow from water-table fluctuations for a general wetland scenario

    Science.gov (United States)

    Weber, Lisa C.; Wiley, Michael J.; Wilcox, Douglas A.

    2016-01-01

    The use of diurnal water-table fluctuation methods to calculate evapotranspiration (ET) and groundwater flow is of increasing interest in ecohydrological studies. Most studies of this type, however, have been located in riparian wetlands of semi-arid regions where groundwater levels are consistently below topographic surface elevations and precipitation events are infrequent. Current methodologies preclude application to a wider variety of wetland systems. In this study, we extended a method for estimating sub-daily ET and groundwater flow rates from water-level fluctuations to fit highly dynamic, non-riparian wetland scenarios. Modifications included (1) varying the specific yield to account for periodic flooded conditions and (2) relating empirically derived ET to estimated potential ET for days when precipitation events masked the diurnal signal. To demonstrate the utility of this method, we estimated ET and groundwater fluxes over two growing seasons (2006–2007) in 15 wetlands within a ridge-and-swale wetland complex of the Laurentian Great Lakes under flooded and non-flooded conditions. Mean daily ET rates for the sites ranged from 4.0 mm d−1 to 6.6 mm d−1. Shallow groundwater discharge rates resulting from evaporative demand ranged from 2.5 mm d−1 to 4.3 mm d−1. This study helps to expand our understanding of the evapotranspirative demand of plants under various hydrologic and climate conditions. Published 2013. This article is a U.S. Government work and is in the public domain in the USA.

  15. The impact of coronary chronic total occlusion percutaneous coronary intervention upon donor vessel fractional flow reserve and instantaneous wave-free ratio: Implications for physiology-guided PCI in patients with CTO.

    Science.gov (United States)

    Mohdnazri, Shah R; Karamasis, Grigoris V; Al-Janabi, Firas; Cook, Christopher M; Hampton-Till, James; Zhang, Jufen; Al-Lamee, Rasha; Dungu, Jason N; Gedela, Swamy; Tang, Kare H; Kelly, Paul A; Davies, Justin E; Davies, John R; Keeble, Thomas R

    2018-03-22

    To investigate the immediate and short term impact of right coronary artery (RCA) chronic total coronary occlusion (CTO) percutaneous coronary intervention (PCI) upon collateral donor vessel fractional flow reserve (FFR) and instantaneous wave-free ratio (iFR). CTO PCI influences collateral donor vessel physiology, making the indication and/or timing of donor vessel revascularization difficult to determine. In patients with RCA CTO, FFR, iFR, and collateral function index (FFR coll ) were measured in LAD and LCx pre-CTO PCI, immediately post and at 4 month follow-up. 34 patients underwent successful PCI. In the predominant donor vessel immediately post PCI, FFR, and FFR coll did not change (0.76 ± 0.12 to 0.75 ± 0.13, P = 0.267 and 0.31 ± 0.10 vs. 0.34 ± 0.11, P = 0.078), but iFR increased significantly (0.86 ± 0.10 to 0.88 ± 0.10, P = 0.012). At follow-up, there was a significant increase in predominant donor FFR and iFR (0.76 ± 0.12 to 0.79 ± 0.11, P = 0.047 and 0.86 ± 0.10 to 0.90 ± 0.07, P = 0.003), accompanied by a significant reduction in FFR coll (0.31 ± 0.10 to 0.18 ± 0.07 P PCI in the case of iFR and at 4-month follow-up for FFR and iFR compared to pre-PCI with a concomitant reduction in collateral function. © 2018 Wiley Periodicals, Inc.

  16. Case Study: On Objective Functions for the Peak Flow Calibration and for the Representative Parameter Estimation of the Basin

    Directory of Open Access Journals (Sweden)

    Jungwook Kim

    2018-05-01

    Full Text Available The objective function is usually used for verification of the optimization process between observed and simulated flows for the parameter estimation of rainfall–runoff model. However, it does not focus on peak flow and on representative parameter for various rain storm events of the basin, but it can estimate the optimal parameters by minimizing the overall error of observed and simulated flows. Therefore, the aim of this study is to suggest the objective functions that can fit peak flow in hydrograph and estimate the representative parameter of the basin for the events. The Streamflow Synthesis And Reservoir Regulation (SSARR model was employed to perform flood runoff simulation for the Mihocheon stream basin in Geum River, Korea. Optimization was conducted using three calibration methods: genetic algorithm, pattern search, and the Shuffled Complex Evolution method developed at the University of Arizona (SCE-UA. Two objective functions of the Sum of Squared of Residual (SSR and the Weighted Sum of Squared of Residual (WSSR suggested in this study for peak flow optimization were applied. Since the parameters estimated using a single rain storm event do not represent the parameters for various rain storms in the basin, we used the representative objective function that can minimize the sum of objective functions of the events. Six rain storm events were used for the parameter estimation. Four events were used for the calibration and the other two for validation; then, the results by SSR and WSSR were compared. Flow runoff simulation was carried out based on the proposed objective functions, and the objective function of WSSR was found to be more useful than that of SSR in the simulation of peak flow runoff. Representative parameters that minimize the objective function for each of the four rain storm events were estimated. The calibrated observed and simulated flow runoff hydrographs obtained from applying the estimated representative

  17. Estimation of the duodenal flow of microbial nitrogen in ruminants based on the chemical composition of forages: a literature review

    NARCIS (Netherlands)

    Gosselink, J.M.J.; Poncet, C.; Dulphy, J.P.; Cone, J.W.

    2003-01-01

    The objective of this study was to evaluate the estimation of the duodenal flow of microbial nitrogen (N) in ruminants fed forage only, per kilogram of dry matter (DM) intake, which is the yield of microbial protein (YMP). The estimation was based on the chemical composition of forages. A data file

  18. Comparison of catchment grouping methods for flow duration curve estimation at ungauged sites in France

    Directory of Open Access Journals (Sweden)

    E. Sauquet

    2011-08-01

    Full Text Available The study aims at estimating flow duration curves (FDC at ungauged sites in France and quantifying the associated uncertainties using a large dataset of 1080 FDCs. The interpolation procedure focuses here on 15 percentiles standardised by the mean annual flow, which is assumed to be known at each site. In particular, this paper discusses the impact of different catchment grouping procedures on the estimation of percentiles by regional regression models.

    In a first step, five parsimonious FDC parametric models are tested to approximate FDCs at gauged sites. The results show that the model based on the expansion of Empirical Orthogonal Functions (EOF outperforms the other tested models. In the EOF model, each FDC is interpreted as a linear combination of regional amplitude functions with spatially variable weighting factors corresponding to the parameters of the model. In this approach, only one amplitude function is required to obtain a satisfactory fit with most of the observed curves. Thus, the considered model requires only two parameters to be applicable at ungauged locations.

    Secondly, homogeneous regions are derived according to hydrological response, on the one hand, and geological, climatic and topographic characteristics on the other hand. Hydrological similarity is assessed through two simple indicators: the concavity index (IC representing the shape of the dimensionless FDC and the seasonality ratio (SR, which is the ratio of summer and winter median flows. These variables are used as homogeneity criteria in three different methods for grouping catchments: (i according to an a priori classification of French Hydro-EcoRegions (HERs, (ii by applying regression tree clustering and (iii by using neighbourhoods obtained by canonical correlation analysis.

    Finally, considering all the data, and subsequently for each group obtained through the tested grouping techniques, we derive regression models between

  19. Comparison of thermal, salt and dye tracing to estimate shallow flow velocities: Novel triple-tracer approach

    Science.gov (United States)

    Abrantes, João R. C. B.; Moruzzi, Rodrigo B.; Silveira, Alexandre; de Lima, João L. M. P.

    2018-02-01

    The accurate measurement of shallow flow velocities is crucial to understand and model the dynamics of sediment and pollutant transport by overland flow. In this study, a novel triple-tracer approach was used to re-evaluate and compare the traditional and well established dye and salt tracer techniques with the more recent thermal tracer technique in estimating shallow flow velocities. For this purpose a triple tracer (i.e. dyed-salted-heated water) was used. Optical and infrared video cameras and an electrical conductivity sensor were used to detect the tracers in the flow. Leading edge and centroid velocities of the tracers were measured and the correction factors used to determine the actual mean flow velocities from tracer measured velocities were compared and investigated. Experiments were carried out for different flow discharges (32-1813 ml s-1) on smooth acrylic, sand, stones and synthetic grass bed surfaces with 0.8, 4.4 and 13.2% slopes. The results showed that thermal tracers can be used to estimate shallow flow velocities, since the three techniques yielded very similar results without significant differences between them. The main advantages of the thermal tracer were that the movement of the tracer along the measuring section was more easily visible than it was in the real image videos and that it was possible to measure space-averaged flow velocities instead of only one velocity value, with the salt tracer. The correction factors used to determine the actual mean velocity of overland flow varied directly with Reynolds and Froude numbers, flow velocity and slope and inversely with flow depth and bed roughness. In shallow flows, velocity estimation using tracers entails considerable uncertainty and caution must be taken with these measurements, especially in field studies where these variables vary appreciably in space and time.

  20. An investigation on how to estimate future cash flows: Evidence from Tehran Stock Exchange

    OpenAIRE

    Roghayeh Ahmdi Panah Banad Koki; Iman Jokar

    2014-01-01

    This paper presents an empirical investigation to predict future cash flows using present cash flow and accruals using the information of 96 selected firms listed on Tehran Stock Exchange over the period 2007-2011. The proposed study uses linear regression techniques to forecast future cash flow and the results indicate that cash flow and accruals together could provide more power to forecast cash flow. In addition, accrual provides future cash flow better than cash flow. The survey also perf...

  1. Groundwater flow analysis and dose rate estimates from releases to wells at a coastal site

    Energy Technology Data Exchange (ETDEWEB)

    Kattilakoski, E.; Suolanen, V. [VTT Energy, Espoo (Finland)

    2000-09-01

    In the groundwater flow modelling part of this work the effective dilution volume in the well scenario was estimated by means of transient simulations of groundwater flow and transport, which are coupled due to the varying salinity. Both deep, drilled wells and shallow surface wells in the vicinity of the repository were considered. The simulations covered the time period from the present to 1000 years after the present. Conceptually the fractured bedrock consists of planar fracture zones (with a high fracture density and a greater ability to conduct water) and the intact rock (in which the fracture density and the hydraulic conductivity are low). For them the equivalent-continuum model was applied separately. Thus, the fractured bedrock was considered as piecewise homogeneous (except for the depth dependence) and isotropic continuum with representative average characteristics. A generic simulation model for groundwater flow and solute transport was developed on the basis of geological, hydrogeological and hydrogeochemical data at a coastal area. The simulation model contains all the data necessary for the numerical simulations, i.e. the groundwater table and topography, salinity, the postglacial land uplift and sea level rise, the conceptual geometry of fracture zones, the hydraulic properties of the bedrock as well as the description of the modelling volume. The model comprises an area of about 26 km{sup 2}. It covers an island and the surrounding sea. The finite element code FEFTRA (formerly known as FEFLOW) was used in this work for the numerical solution. The channelling along the flow routes was found to be critical for the resulting in a well. A deep well may extend near the area of the deep flow routes, but in order to get flow routes into a shallow well, it has to be placed in the immediate vicinity of the discharge areas. According to the groundwater flow analyses the effective dilution volume of the well seems to vary from 30 000 m{sup 3}/a to 460 000 m

  2. Analysis of digital subtraction coronary angiography for estimation of flow reserve in critical coronary stenosis

    International Nuclear Information System (INIS)

    Kohtoku, Shinya

    1988-01-01

    To examine the accuracy of digital subtraction angiographic assessment of coronary flow reserve in critical coronary stenosis, time-density curve was obtained from digital subtraction coronary angiograms for myocardial region of interest. Time to peak contrast(TPC) and time constant of the washout exponential curve(T) were measured in 14 patients with stable effort angina pectoris and critical one vessel lesion before and after percutaneous transluminal coronary angioplasty(PTCA). All patients had normal left ventricular ejection fraction (59 ± 7 %) and Tl 201 myocardial image at rest. The values of TPC and T were significantly shortened from 5.4 ± 1.3 to 4.5 ± 1.0 sec (p < 0.02) and from 10.9 ± 3.8 to 5.3 ± 1.3 sec(p < 0.001) after PTCA, respectively. However, in 9 of all patients TPC after PTCA showed approximately the same valued as those before PTCA. In 5 experimental dogs with critical circumflex stenosis, coronary flow(CF;Doppler flow meter) and systolic thickning of the posterior wall(by sonomicrometry) at rest were not different from control, however, contrast media-induced reactive hyperemia was markedly attenuated, accompanied with a significant of T (7.7 ± 4.5 vs 15.8 ± 10.9 sec, p < 0.01) and completely unchanged TPC (both 6.8 sec). With simultaneous tracing of CF and time-density curve, TPC and washout phase corresponded with contrast-induced transient CF reduction and hyperemic phase, respectively. We conclude that T might be more sensitive for estimation of CF is maintained almost normal, such as patients with stable effort angina pectoris having normal left ventricular wall motion at rest. (author)

  3. Association of coronary ischemia estimated by fractional flow reserve and psychological characteristics of patients

    Directory of Open Access Journals (Sweden)

    Miodrag Jovan Sreckovic

    2017-05-01

    Full Text Available Introduction : Psychological characteristics of patients, depression, stress and anxiety are recognized as important confounding risk factors for ischemic heart disease. However, the impact of psychological characteristics on coronary ischemia and vice versa remain poorly understood. Aim: To demonstrate the interplay of psychological characteristics, depression, stress and anxiety with coronary ischemia estimated with fractional flow reserve (FFR. Material and methods : From 2014 to 2016, 147 patients who were planned for FFR measurement were included in this study. Psychological characteristics of patients were evaluated using the Depression, Anxiety and Stress Scale 21 items (DASS 21 self-report questionnaire. Results : Comparing the FFR ischemic vs. FFR non-ischemic groups, a significant difference was observed regarding results achieved for the depression, anxiety and stress scales. Multivariate logistic regression analysis was used to model the correlation between FFR and the DAS scale. It was clear, when controlling for previous myocardial infarction, that FFR was significant in all analyses. However, when the Canadian Cardiovascular Society grading of angina pectoris (CCS class was entered in the model, FFR was not a significant predictor of anxiety, but was significant in other analysis. Conclusions : Higher degrees of the psychological characteristics depression, stress and anxiety were observed in the group of patients with coronary ischemia, corresponding to lower fractional flow values.

  4. Noninvasive estimation of pulmonary arterial pressure by analysis of pulmonary blood-flow distribution

    International Nuclear Information System (INIS)

    Konstam, M.A.; Strauss, H.W.; Alpert, N.M.; Miller, S.W.; Murphy, R.X.; Greene, R.E.; McKusick, K.A.

    1979-01-01

    To determine whether a correlation exists between pulmonary arterial (PA) pressure (P/sub a/) and the distribution of pulmonary blood flow, this distribution was measured in four upright dogs in the control state and during intravenous infusions of epinephrine or prostaglandin F/sub 2α/. During suspension of respiration, 15 mCi of Xe-133 were injected intravenously, and perfusion and equilibration lung images were recorded with a scintillation camera. The procedure was performed several times on each dog, with and without pharmacological elevation of PA pressure by 5 to 50 cm H 2 O. For each scintigram, the relative blood flow per unit ventilated lung volume (F) was plotted against centimeters above the hilum (h). Pulmonary arterial pressure was derived from each curve, assuming the relation F = B(P/sub a/ - hD) 2 , where B = constant and D = specific gravity of blood. Calculated PA pressure correlated strongly (r = 0.83) with measured PA pressure, suggesting a possible means of noninvasive estimation of PA pressure

  5. Estimation of nitrogen and phosphorus flows in livestock production in Dianchi Lake basin, China.

    Science.gov (United States)

    Anzai, Hiroki; Wang, Lin; Oishi, Kazato; Irbis, Chagan; Li, Kunzhi; Kumagai, Hajime; Inamura, Tatsuya; Hirooka, Hiroyuki

    2016-01-01

    We assessed the nitrogen (N) and phosphorus (P) flows in intensified livestock production systems by investigating nutrient budgets and cycling in the basin of Dianchi Lake, one of the most eutrophic lakes in China. We conducted field surveys based on feed samplings and interviews of livestock farmers. The N and P in local and external feeds, animal body retentions, animal products and excretions were calculated at the individual level for dairy cattle, fattening pigs, breeding sows, broilers and laying hens. The N and P flows in the total livestock production system in the area were estimated by multiplying the individual N and P budgets by the number of animals. For the dairy and fattening pig productions, N and P supplied from local crops or by-products accounted for large parts of the inputs. For the other livestock categories, most of the N and P inputs depended on external resources. The N and P outputs through animal manure into the cropland were 287 and 66 kg/ha/year, respectively, which were higher than the N and P inputs into the livestock production systems from the cropland. The N and P loads from manure should be reduced for the establishment of sustainable agricultural production systems. © 2015 Japanese Society of Animal Science.

  6. Stochastic estimation of flow near the trailing edge of a NACA0012 airfoil

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Sagrado, Ana [University of Cambridge, Whittle Laboratory, Department of Engineering, Cambridge (United Kingdom); Applied Modelling and Computation Group, Department of Earth Science and Engineering, Royal School of Mines, Imperial College London, London (United Kingdom); Hynes, Tom [University of Cambridge, Whittle Laboratory, Department of Engineering, Cambridge (United Kingdom)

    2011-10-15

    A stochastic estimation technique has been applied to simultaneously acquired data of velocity and surface pressure as a tool to identify the sources of wall-pressure fluctuations. The measurements have been done on a NACA0012 airfoil at a Reynolds number of Re{sub c} = 2 x 10 {sup 5}, based on the chord of the airfoil, where a separated laminar boundary layer was present. By performing simultaneous measurements of the surface pressure fluctuations and of the velocity field in the boundary layer and wake of the airfoil, the wall-pressure sources near the trailing edge (TE) have been studied. The mechanisms and flow structures associated with the generation of the surface pressure have been investigated. The ''quasi-instantaneous'' velocity field resulting from the application of the technique has led to a picture of the evolution in time of the convecting surface pressure generating flow structures and revealed information about the sources of the wall-pressure fluctuations, their nature and variability. These sources are closely related to those of the radiated noise from the TE of an airfoil and to the vibration issues encountered in ship hulls for example. The NACA0012 airfoil had a 30 cm chord and aspect ratio of 1. (orig.)

  7. A method of estimating inspiratory flow rate and volume from an inhaler using acoustic measurements

    International Nuclear Information System (INIS)

    Holmes, Martin S; D'Arcy, Shona; O'Brien, Ultan; Reilly, Richard B; Seheult, Jansen N; Geraghty, Colm; Costello, Richard W; Crispino O'Connell, Gloria

    2013-01-01

    Inhalers are devices employed to deliver medication to the airways in the treatment of respiratory diseases such as asthma and chronic obstructive pulmonary disease. A dry powder inhaler (DPI) is a breath actuated inhaler that delivers medication in dry powder form. When used correctly, DPIs improve patients' clinical outcomes. However, some patients are unable to reach the peak inspiratory flow rate (PIFR) necessary to fully extract the medication. Presently clinicians have no reliable method of objectively measuring PIFR in inhalers. In this study, we propose a novel method of estimating PIFR and also the inspiratory capacity (IC) of patients' inhalations from a commonly used DPI, using acoustic measurements. With a recording device, the acoustic signal of 15 healthy subjects using a DPI over a range of varying PIFR and IC values was obtained. Temporal and spectral signal analysis revealed that the inhalation signal contains sufficient information that can be employed to estimate PIFR and IC. It was found that the average power (P ave ) in the frequency band 300–600 Hz had the strongest correlation with PIFR (R 2 = 0.9079), while the power in the same frequency band was also highly correlated with IC (R 2 = 0.9245). This study has several clinical implications as it demonstrates the feasibility of using acoustics to objectively monitor inhaler use. (paper)

  8. Flow measurement and thrust estimation of a vibrating ionic polymer metal composite

    International Nuclear Information System (INIS)

    Chae, Woojin; Cha, Youngsu; Peterson, Sean D; Porfiri, Maurizio

    2015-01-01

    Ionic polymer metal composites (IPMCs) are an emerging class of soft active materials that are finding growing application as underwater propulsors for miniature biomimetic swimmers. Understanding the hydrodynamics generated by an IPMC vibrating under water is central to the design of such biomimetic swimmers. In this paper, we propose the use of time-resolved particle image velocimetry to detail the fluid kinematics and kinetics in the vicinity of an IPMC vibrating along its fundamental structural mode. The reconstructed pressure field is ultimately used to estimate the thrust produced by the IPMC. The vibration frequency is systematically varied to elucidate the role of the Reynolds number on the flow physics and the thrust production. Experimental results indicate the formation and shedding of vortical structures from the IPMC tip during its vibration. Vorticity shedding is sustained by the pressure gradients along each side of the IPMC, which are most severe in the vicinity of the tip. The mean thrust is found to robustly increase with the Reynolds number, closely following a power law that has been derived from direct three-dimensional numerical simulations. A reduced order distributed model is proposed to describe IPMC underwater vibration and estimate thrust production, offering insight into the physics of underwater propulsion and aiding in the design of IPMC-based propulsors. (paper)

  9. Distributed flow estimation and closed-loop control of an underwater vehicle with a multi-modal artificial lateral line.

    Science.gov (United States)

    DeVries, Levi; Lagor, Francis D; Lei, Hong; Tan, Xiaobo; Paley, Derek A

    2015-03-25

    Bio-inspired sensing modalities enhance the ability of autonomous vehicles to characterize and respond to their environment. This paper concerns the lateral line of cartilaginous and bony fish, which is sensitive to fluid motion and allows fish to sense oncoming flow and the presence of walls or obstacles. The lateral line consists of two types of sensing modalities: canal neuromasts measure approximate pressure gradients, whereas superficial neuromasts measure local flow velocities. By employing an artificial lateral line, the performance of underwater sensing and navigation strategies is improved in dark, cluttered, or murky environments where traditional sensing modalities may be hindered. This paper presents estimation and control strategies enabling an airfoil-shaped unmanned underwater vehicle to assimilate measurements from a bio-inspired, multi-modal artificial lateral line and estimate flow properties for feedback control. We utilize potential flow theory to model the fluid flow past a foil in a uniform flow and in the presence of an upstream obstacle. We derive theoretically justified nonlinear estimation strategies to estimate the free stream flowspeed, angle of attack, and the relative position of an upstream obstacle. The feedback control strategy uses the estimated flow properties to execute bio-inspired behaviors including rheotaxis (the tendency of fish to orient upstream) and station-holding (the tendency of fish to position behind an upstream obstacle). A robotic prototype outfitted with a multi-modal artificial lateral line composed of ionic polymer metal composite and embedded pressure sensors experimentally demonstrates the distributed flow sensing and closed-loop control strategies.

  10. Estimated water withdrawals and return flows in Vermont in 2005 and 2020

    Science.gov (United States)

    Medalie, Laura; Horn, Marilee A.

    2010-01-01

    these MCDs had small populations themselves but provided water to community water systems in neighboring towns or cities. Wilmington probably will be added to this list by 2020 because of proposed new withdrawals for snowmaking in Dover. About 15 percent of MCDs had greater return flows than withdrawals; possible reasons are water importation, larger service areas for municipal sewer than for municipal water resulting in underestimation of withdrawals, leakage into sewer pipes, faulty assumptions in assigning coefficients, or other limitations of the study methods. To store and facilitate retrieval of water-use estimates and data for 2005 and projections for 2020, a water-use database for Vermont was designed and populated. Data include withdrawals and return flows from and to groundwater and surface water for all individual facilities and entities that are in Vermont drinking water, discharge permit, or other State water-use databases, along with estimates for many other facilities. Also included are estimates for aggregated domestic and livestock withdrawals and return flows by census block. Retrievals from the database and summaries presented in this report can be used to help identify areas where projected growth in Vermont from 2005 to 2020 might affect groundwater availability.

  11. A residual-based a posteriori error estimator for single-phase Darcy flow in fractured porous media

    KAUST Repository

    Chen, Huangxin

    2016-12-09

    In this paper we develop an a posteriori error estimator for a mixed finite element method for single-phase Darcy flow in a two-dimensional fractured porous media. The discrete fracture model is applied to model the fractures by one-dimensional fractures in a two-dimensional domain. We consider Raviart–Thomas mixed finite element method for the approximation of the coupled Darcy flows in the fractures and the surrounding porous media. We derive a robust residual-based a posteriori error estimator for the problem with non-intersecting fractures. The reliability and efficiency of the a posteriori error estimator are established for the error measured in an energy norm. Numerical results verifying the robustness of the proposed a posteriori error estimator are given. Moreover, our numerical results indicate that the a posteriori error estimator also works well for the problem with intersecting fractures.

  12. Laparoscopic donor nephrectomy increases the supply of living donor kidneys: a center-specific microeconomic analysis.

    Science.gov (United States)

    Kuo, P C; Johnson, L B

    2000-05-27

    A tenet of microeconomics is that new technology will shift the supply curve to the right. Laparoscopic donor nephrectomy (LDN) is a new technique for removal of living donor kidneys. Centers performing this procedure have noted an increased number of patients presenting for donor evaluation. This has not been previously studied. The records of all LDN performed from May 1998 to February 1999 were reviewed. The following variables were examined: sex, age, related vs. unrelated donation, estimated blood loss, i.v. analgesia, length of stay, and time out of work. Donors undergoing traditional open donor nephrectomy during January 1997 to May 1998 served as the control group. A composite cost index was constructed. LDN significantly decreased length of stay, pain, and time out of work; the supply function shifted to the right. Telephone interviews revealed that 47% donated solely because of the LDN procedure. LDN increases the supply of living donor kidneys.

  13. Analysis of digital subtraction angiography for estimating flow reserve in critical coronary artery stenosis

    International Nuclear Information System (INIS)

    Kotoku, Shinya; Matsuzaki, Masunori; Otani, Nozomi

    1988-01-01

    To assess the accuracy of digital subtraction angiography in evaluating coronary flow reserve in cases with critical coronary artery stenosis, time-density curves were obtained from digital subtraction coronary angiograms in the myocardial region of interest. Time to peak contrast (TPC) and time constant of the washout exponential curve (T) were measured in 14 patients with stable effort angina pectoris and critical one vessel lesion before and after percutaneous transluminal coronary angioplasty (PTCA). All patients had normal left ventricular ejection fraction (59±7%) and 201 Tl myocardial images at rest. The values of TPC and T were significantly shortened from 5.4±1.3 to 4.5±1.0 sec (p<0.02) and from 10.9±3.8 to 5.3±1.3 sec (p<0.001) after PTCA, respectively. However, in 9 patients TPC values were approximately the same before and after PTCA. In five experimental dogs with critical circumflex coronary artery stenosis, coronary flow (CF; Doppler flowmeter) and systolic thickening of the posterior wall (by sonomicrometry) at rest did not differ from those of the controls. However, contrast media-induced reactive hyperemia was markedly attenuated, accompanied by a significant increase in T (7.7±4.5 vs 15.8±10.9 sec, p<0.01) and totally unchanged TPC (both 6.8 sec). With simultaneous tracings of CF and time-density curves, TPC and washout phases corresponded with contrast-induced transient CF reduction and hyperemic phases, respectively. We concluded that T may be more sensitive for estimating CF maintained nearly normal, e.g., in patients with stable effort angina pectoris having normal left ventricular wall motion at rest. (author)

  14. Construction of estimated flow- and load-duration curves for Kentucky using the Water Availability Tool for Environmental Resources (WATER)

    Science.gov (United States)

    Unthank, Michael D.; Newson, Jeremy K.; Williamson, Tanja N.; Nelson, Hugh L.

    2012-01-01

    Flow- and load-duration curves were constructed from the model outputs of the U.S. Geological Survey's Water Availability Tool for Environmental Resources (WATER) application for streams in Kentucky. The WATER application was designed to access multiple geospatial datasets to generate more than 60 years of statistically based streamflow data for Kentucky. The WATER application enables a user to graphically select a site on a stream and generate an estimated hydrograph and flow-duration curve for the watershed upstream of that point. The flow-duration curves are constructed by calculating the exceedance probability of the modeled daily streamflows. User-defined water-quality criteria and (or) sampling results can be loaded into the WATER application to construct load-duration curves that are based on the modeled streamflow results. Estimates of flow and streamflow statistics were derived from TOPographically Based Hydrological MODEL (TOPMODEL) simulations in the WATER application. A modified TOPMODEL code, SDP-TOPMODEL (Sinkhole Drainage Process-TOPMODEL) was used to simulate daily mean discharges over the period of record for 5 karst and 5 non-karst watersheds in Kentucky in order to verify the calibrated model. A statistical evaluation of the model's verification simulations show that calibration criteria, established by previous WATER application reports, were met thus insuring the model's ability to provide acceptably accurate estimates of discharge at gaged and ungaged sites throughout Kentucky. Flow-duration curves are constructed in the WATER application by calculating the exceedence probability of the modeled daily flow values. The flow-duration intervals are expressed as a percentage, with zero corresponding to the highest stream discharge in the streamflow record. Load-duration curves are constructed by applying the loading equation (Load = Flow*Water-quality criterion) at each flow interval.

  15. A Real-Time Method to Estimate Speed of Object Based on Object Detection and Optical Flow Calculation

    Science.gov (United States)

    Liu, Kaizhan; Ye, Yunming; Li, Xutao; Li, Yan

    2018-04-01

    In recent years Convolutional Neural Network (CNN) has been widely used in computer vision field and makes great progress in lots of contents like object detection and classification. Even so, combining Convolutional Neural Network, which means making multiple CNN frameworks working synchronously and sharing their output information, could figure out useful message that each of them cannot provide singly. Here we introduce a method to real-time estimate speed of object by combining two CNN: YOLOv2 and FlowNet. In every frame, YOLOv2 provides object size; object location and object type while FlowNet providing the optical flow of whole image. On one hand, object size and object location help to select out the object part of optical flow image thus calculating out the average optical flow of every object. On the other hand, object type and object size help to figure out the relationship between optical flow and true speed by means of optics theory and priori knowledge. Therefore, with these two key information, speed of object can be estimated. This method manages to estimate multiple objects at real-time speed by only using a normal camera even in moving status, whose error is acceptable in most application fields like manless driving or robot vision.

  16. An estimation of reactor thermal power uncertainty using UFM-based feedwater flow rate in nuclear power plants

    International Nuclear Information System (INIS)

    Byung Ryul Jung; Ho Cheol Jang; Byung Jin Lee; Se Jin Baik; Woo Hyun Jang

    2005-01-01

    Most of Pressurized Water Reactors (PWRs) utilize the venturi meters (VMs) to measure the feedwater (FW) flow rate to the steam generator in the calorimetric measurement, which is used in the reactor thermal power (RTP) estimation. However, measurement drifts have been experienced due to some anomalies on the venturi meter (generally called the venturi meter fouling). The VM's fouling tends to increase the measured pressure drop across the meter, which results in indication of increased feedwater flow rate. Finally, the reactor thermal power is overestimated and the actual reactor power is to be reduced to remain within the regulatory limits. To overcome this VM's fouling problem, the Ultrasonic Flow Meter (UFM) has recently been gaining attention in the measurement of the feedwater flow rate. This paper presents the applicability of a UFM based feedwater flow rate in the estimation of reactor thermal power uncertainty. The FW and RTP uncertainties are compared in terms of sensitivities between the VM- and UFM-based feedwater flow rates. Data from typical Optimized Power Reactor 1000 (OPR1000) plants are used to estimate the uncertainty. (authors)

  17. A remark on "Nonlinear output feedback control of underwater vehicle propellers using feedback form estimated axial flow velocity"

    DEFF Research Database (Denmark)

    Jouffroy, Jerome; Lottin, Jacques

    2002-01-01

    For original paper see T.I.Fossen and M.Blanke, ibid., vol.25, pp.241-55 (2000). In the work presented by Fossen and Blanke, a nonlinear observer for estimation of propeller axial flow velocity for UUVs was introduced. The proof of the convergence behavior of the observer was carried out with a L......For original paper see T.I.Fossen and M.Blanke, ibid., vol.25, pp.241-55 (2000). In the work presented by Fossen and Blanke, a nonlinear observer for estimation of propeller axial flow velocity for UUVs was introduced. The proof of the convergence behavior of the observer was carried out...

  18. Stream flow - its estimation, uncertainty and interaction with groundwater and floodplains

    DEFF Research Database (Denmark)

    Poulsen, Jane Bang

    , floodplain hydraulics and sedimentation patterns has been investigated along a restored channel section of Odense stream, Denmark. Collected samples of deposited sediment, organic matter and phosphorus on the floodplain were compared with results from a 2D dynamic flow model. Three stage dependent flow...... regimes were predicted by the flow model with shifting primary overbank flow and zones of flow confluence. These dynamic flow patterns were found to correlate with the spatial deposition of total phosphorus (11.4 g m-2), organic matter (0.65 kg m-2) and sediment (4.72 kg m-2), and zones of major total...... sediment deposition coincided with the flow confluence zones. The revealed complex spatially and temporally changing floodplain flow pattern was found to play a decisive role for the deposition processes. The interaction between stream flow and groundwater from catchment to point scale has been...

  19. Effects of cypress knee roughness on flow resistance and discharge estimates of the Turkey Creek watershed

    Directory of Open Access Journals (Sweden)

    Miroslaw-Swiatek Dorota

    2017-09-01

    Full Text Available Effects of cypress knee roughness on flow resistance and discharge estimates of the Turkey Creek watershed. In this study effects of cypress knees as vegetation resistance factor on Turkey Creek watershed discharge calculation were analyzed. The Turkey Creek watershed is a 3rd order stream system draining an approximate area of 5,240 ha. It is located at 33°08' N latitude and 79°47' W longitude, approximately 60 km north-west of City of Charleston in South Carolina (USA. Turkey Creek (WS 78 is typical of other watersheds in the south Atlantic coastal plain. In the case of Turkey Creek watershed, one of the main channels and riparian floodplain vegetation contains cypress trees. Cypress trees live in moist or swampy regions along the Atlantic coastal plain. The cypress trees are characterized by the unique root system called knees that appear just above the water line, up to 1.2 m above water surface. This study is conducted to examine the effects of roughness of cypress knee as related to its shape (diameter and height on discharge estimates of the Turkey Creek watershed. Hydraulic characteristics of the cypress knees were determined by field inventory in selected cross-section along the main stream channel. The Pasche method was used to calculate the total Darcy–Weisbach friction factor in discharge capacity calculation of the study watershed. The results of this study show that the effect of vegetation shape in the Pasche approach is significant. If the variability of vegetation stem diameter is taken into consideration in the calculations, an increase by 10–32% in the values of friction coefficients occurs.

  20. Theoretical estimation of adiabatic temperature rise from the heat flow data obtained from a reaction calorimeter

    International Nuclear Information System (INIS)

    Das, Parichay K.

    2012-01-01

    Highlights: ► This method for estimating ΔT ad (t) against time in a semi-batch reactor is distinctively pioneer and novel. ► It has established uniquely a direct correspondence between the evolution of ΔT ad (t) in RC and C A (t) in a semi-batch reactor. ► Through a unique reaction scheme, the independent effects of heat of mixing and reaction on ΔT ad (t) has been demonstrated quantitatively. ► This work will help to build a thermally safe corridor of a thermally hazard reaction. ► This manuscript, the author believes will open a new vista for further research in Adiabatic Calorimetry. - Abstract: A novel method for estimating the transient profile of adiabatic rise in temperature has been developed from the heat flow data for exothermic chemical reactions that are conducted in reaction calorimeter (RC). It has also been mathematically demonstrated by the present design that there exists a direct qualitative equivalence between the temporal evolution of the adiabatic temperature rise and the concentration of the limiting reactant for an exothermic chemical reaction, carried out in semi batch mode. The proposed procedure shows that the adiabatic temperature rise will always be less than that of the reaction executed at batch mode thereby affording a thermally safe corridor. Moreover, a unique reaction scheme has been designed to establish the independent heat effect of dissolution and reaction quantitatively. It is hoped that the testimony of the transient adiabatic temperature rise that can be prepared by the proposed method, may provide ample scope for further research.

  1. Adaptive finite element analysis of incompressible viscous flow using posteriori error estimation and control of node density distribution

    International Nuclear Information System (INIS)

    Yashiki, Taturou; Yagawa, Genki; Okuda, Hiroshi

    1995-01-01

    The adaptive finite element method based on an 'a posteriori error estimation' is known to be a powerful technique for analyzing the engineering practical problems, since it excludes the instinctive aspect of the mesh subdivision and gives high accuracy with relatively low computational cost. In the adaptive procedure, both the error estimation and the mesh generation according to the error estimator are essential. In this paper, the adaptive procedure is realized by the automatic mesh generation based on the control of node density distribution, which is decided according to the error estimator. The global percentage error, CPU time, the degrees of freedom and the accuracy of the solution of the adaptive procedure are compared with those of the conventional method using regular meshes. Such numerical examples as the driven cavity flows of various Reynolds numbers and the flows around a cylinder have shown the very high performance of the proposed adaptive procedure. (author)

  2. Incorporating a Time Horizon in Rate-of-Return Estimations: Discounted Cash Flow Model in Electric Transmission Rate Cases

    International Nuclear Information System (INIS)

    Chatterjee, Bishu; Sharp, Peter A.

    2006-01-01

    Electric transmission and other rate cases use a form of the discounted cash flow model with a single long-term growth rate to estimate rates of return on equity. It cannot incorporate information about the appropriate time horizon for which analysts' estimates of earnings growth have predictive powers. Only a non-constant growth model can explicitly recognize the importance of the time horizon in an ROE calculation. (author)

  3. Estimation of the supplementary axial wall stress generated at peak flow by an arterial stenosis

    International Nuclear Information System (INIS)

    Doriot, Pierre-Andre

    2003-01-01

    Mechanical stresses in arterial walls are known to be implicated in the development of atherosclerosis. While shear stress and circumferential stress have received a lot of attention, axial stress has not. Yet, stenoses can be intuitively expected to produce a supplementary axial stress during flow systole in the region immediately proximal to the constriction cone. In this paper, a model for the estimation of this effect is presented, and ten numerical examples are computed. These examples show that the cyclic increase in axial stress can be quite considerable in severe stenoses (typically 120% or more of the normal stress value). This result is in best agreement with the known mechanical or morphological risk factors of stenosis progression and restenosis (hypertension, elevated pulse pressure, degree of stenosis, stenosis geometry, residual stenosis, etc). The supplementary axial stress generated by a stenosis might create the damages in the endothelium and in the elastic membranes which potentiate the action of the other risk factors (hyperlipidaemia, diabetes, etc). It could thus be an important cause of stenosis progression and of restenosis

  4. Nonlinear parameter estimation in inviscid compressible flows in presence of uncertainties

    International Nuclear Information System (INIS)

    Jemcov, A.; Mathur, S.

    2004-01-01

    The focus of this paper is on the formulation and solution of inverse problems of parameter estimation using algorithmic differentiation. The inverse problem formulated here seeks to determine the input parameters that minimize a least squares functional with respect to certain target data. The formulation allows for uncertainty in the target data by considering the least squares functional in a stochastic basis described by the covariance of the target data. Furthermore, to allow for robust design, the formulation also accounts for uncertainties in the input parameters. This is achieved using the method of propagation of uncertainties using the directional derivatives of the output parameters with respect to unknown parameters. The required derivatives are calculated simultaneously with the solution using generic programming exploiting the template and operator overloading features of the C++ language. The methodology described here is general and applicable to any numerical solution procedure for any set of governing equations but for the purpose of this paper we consider a finite volume solution of the compressible Euler equations. In particular, we illustrate the method for the case of supersonic flow in a duct with a wedge. The parameter to be determined is the inlet Mach number and the target data is the axial component of velocity at the exit of the duct. (author)

  5. Estimation of distribution algorithm with path relinking for the blocking flow-shop scheduling problem

    Science.gov (United States)

    Shao, Zhongshi; Pi, Dechang; Shao, Weishi

    2018-05-01

    This article presents an effective estimation of distribution algorithm, named P-EDA, to solve the blocking flow-shop scheduling problem (BFSP) with the makespan criterion. In the P-EDA, a Nawaz-Enscore-Ham (NEH)-based heuristic and the random method are combined to generate the initial population. Based on several superior individuals provided by a modified linear rank selection, a probabilistic model is constructed to describe the probabilistic distribution of the promising solution space. The path relinking technique is incorporated into EDA to avoid blindness of the search and improve the convergence property. A modified referenced local search is designed to enhance the local exploitation. Moreover, a diversity-maintaining scheme is introduced into EDA to avoid deterioration of the population. Finally, the parameters of the proposed P-EDA are calibrated using a design of experiments approach. Simulation results and comparisons with some well-performing algorithms demonstrate the effectiveness of the P-EDA for solving BFSP.

  6. Estimation of the supplementary axial wall stress generated at peak flow by an arterial stenosis

    Science.gov (United States)

    Doriot, Pierre-André

    2003-01-01

    Mechanical stresses in arterial walls are known to be implicated in the development of atherosclerosis. While shear stress and circumferential stress have received a lot of attention, axial stress has not. Yet, stenoses can be intuitively expected to produce a supplementary axial stress during flow systole in the region immediately proximal to the constriction cone. In this paper, a model for the estimation of this effect is presented, and ten numerical examples are computed. These examples show that the cyclic increase in axial stress can be quite considerable in severe stenoses (typically 120% or more of the normal stress value). This result is in best agreement with the known mechanical or morphological risk factors of stenosis progression and restenosis (hypertension, elevated pulse pressure, degree of stenosis, stenosis geometry, residual stenosis, etc). The supplementary axial stress generated by a stenosis might create the damages in the endothelium and in the elastic membranes which potentiate the action of the other risk factors (hyperlipidaemia, diabetes, etc). It could thus be an important cause of stenosis progression and of restenosis.

  7. Laparoscopic donor nephrectomy

    Directory of Open Access Journals (Sweden)

    Gupta Nitin

    2005-01-01

    Full Text Available Of the various options for patients with end stage renal disease, kidney transplantation is the treatment of choice for a suitable patient. The kidney for transplantation is retrieved from either a cadaver or a live donor. Living donor nephrectomy has been developed as a method to address the shortfall in cadaveric kidneys available for transplantation. Laparoscopic living donor nephrectomy (LLDN, by reducing postoperative pain, shortening convalescence, and improving the cosmetic outcome of the donor nephrectomy, has shown the potential to increase the number of living kidney donations further by removing some of the disincentives inherent to donation itself. The technique of LLDN has undergone evolution at different transplant centers and many modifications have been done to improve donor safety and recipient outcome. Virtually all donors eligible for an open surgical procedure may also undergo the laparoscopic operation. Various earlier contraindications to LDN, such as right donor kidney, multiple vessels, anomalous vasculature and obesity have been overcome with increasing experience. Laparoscopic live donor nephrectomy can be done transperitoneally or retroperitoneally on either side. The approach is most commonly transperitoneal, which allows adequate working space and easy dissection. A review of literature and our experience with regards to standard approach and the modifications is presented including a cost saving model for the developing countries. An assessment has been made, of the impact of LDN on the outcome of donor and the recipient.

  8. Myocardial blood flow estimates from dynamic contrast-enhanced magnetic resonance imaging: three quantitative methods

    Science.gov (United States)

    Borrazzo, Cristian; Galea, Nicola; Pacilio, Massimiliano; Altabella, Luisa; Preziosi, Enrico; Carnì, Marco; Ciolina, Federica; Vullo, Francesco; Francone, Marco; Catalano, Carlo; Carbone, Iacopo

    2018-02-01

    Dynamic contrast-enhanced cardiovascular magnetic resonance imaging can be used to quantitatively assess the myocardial blood flow (MBF), recovering the tissue impulse response function for the transit of a gadolinium bolus through the myocardium. Several deconvolution techniques are available, using various models for the impulse response. The method of choice may influence the results, producing differences that have not been deeply investigated yet. Three methods for quantifying myocardial perfusion have been compared: Fermi function modelling (FFM), the Tofts model (TM) and the gamma function model (GF), with the latter traditionally used in brain perfusion MRI. Thirty human subjects were studied at rest as well as under cold pressor test stress (submerging hands in ice-cold water), and a single bolus of gadolinium weighing 0.1  ±  0.05 mmol kg-1 was injected. Perfusion estimate differences between the methods were analysed by paired comparisons with Student’s t-test, linear regression analysis, and Bland-Altman plots, as well as also using the two-way ANOVA, considering the MBF values of all patients grouped according to two categories: calculation method and rest/stress conditions. Perfusion estimates obtained by various methods in both rest and stress conditions were not significantly different, and were in good agreement with the literature. The results obtained during the first-pass transit time (20 s) yielded p-values in the range 0.20-0.28 for Student’s t-test, linear regression analysis slopes between 0.98-1.03, and R values between 0.92-1.01. From the Bland-Altman plots, the paired comparisons yielded a bias (and a 95% CI)—expressed as ml/min/g—for FFM versus TM, -0.01 (-0.20, 0.17) or 0.02 (-0.49, 0.52) at rest or under stress respectively, for FFM versus GF, -0.05 (-0.29, 0.20) or  -0.07 (-0.55, 0.41) at rest or under stress, and for TM versus GF, -0.03 (-0.30, 0.24) or  -0.09 (-0.43, 0.26) at rest or under stress. With the

  9. Estimation of urinary flow velocity in models of obstructed and unobstructed urethras by decorrelation of ultrasound radiofrequency signals

    NARCIS (Netherlands)

    Arif, M.; Idzenga, T.; Mastrigt, R. van; Korte, C.L. de

    2014-01-01

    The feasibility of estimating urinary flow velocity from the decorrelation of radiofrequency (RF) signals was investigated in soft tissue-mimicking models of obstructed and unobstructed urethras. The decorrelation was studied in the near field, focal zone and far field of the ultrasound beam.

  10. Estimating Bus Loads and OD Flows Using Location-Stamped Farebox and Wi-Fi Signal Data

    Directory of Open Access Journals (Sweden)

    Yuxiong Ji

    2017-01-01

    Full Text Available Electronic fareboxes integrated with Automatic Vehicle Location (AVL systems can provide location-stamped records to infer passenger boarding at individual stops. However, bus loads and Origin-Destination (OD flows, which are useful for route planning, design, and real-time controls, cannot be derived directly from farebox data. Recently, Wi-Fi sensors have been used to collect passenger OD flow information. But the data are insufficient to capture the variation of passenger demand across bus trips. In this study, we propose a hierarchical Bayesian model to estimate trip-level OD flow matrices and a period-level OD flow matrix using sampled OD flow data collected by Wi-Fi sensors and boarding data provided by fareboxes. Bus loads on each bus trip are derived directly from the estimated trip-level OD flow matrices. The proposed method is evaluated empirically on an operational bus route and the results demonstrate that it provides good and detailed transit route-level passenger demand information by combining farebox and Wi-Fi signal data.

  11. Estimation of exhaust gas aerodynamic force on the variable geometry turbocharger actuator: 1D flow model approach

    International Nuclear Information System (INIS)

    Ahmed, Fayez Shakil; Laghrouche, Salah; Mehmood, Adeel; El Bagdouri, Mohammed

    2014-01-01

    Highlights: • Estimation of aerodynamic force on variable turbine geometry vanes and actuator. • Method based on exhaust gas flow modeling. • Simulation tool for integration of aerodynamic force in automotive simulation software. - Abstract: This paper provides a reliable tool for simulating the effects of exhaust gas flow through the variable turbine geometry section of a variable geometry turbocharger (VGT), on flow control mechanism. The main objective is to estimate the resistive aerodynamic force exerted by the flow upon the variable geometry vanes and the controlling actuator, in order to improve the control of vane angles. To achieve this, a 1D model of the exhaust flow is developed using Navier–Stokes equations. As the flow characteristics depend upon the volute geometry, impeller blade force and the existing viscous friction, the related source terms (losses) are also included in the model. In order to guarantee stability, an implicit numerical solver has been developed for the resolution of the Navier–Stokes problem. The resulting simulation tool has been validated through comparison with experimentally obtained values of turbine inlet pressure and the aerodynamic force as measured at the actuator shaft. The simulator shows good compliance with experimental results

  12. Distributed Cerebral Blood Flow estimation using a spatiotemporal hemodynamic response model and a Kalman-like Filter approach

    KAUST Repository

    Belkhatir, Zehor

    2015-11-23

    This paper discusses the estimation of distributed Cerebral Blood Flow (CBF) using spatiotemporal traveling wave model. We consider a damped wave partial differential equation that describes a physiological relationship between the blood mass density and the CBF. The spatiotemporal model is reduced to a finite dimensional system using a cubic b-spline continuous Galerkin method. A Kalman Filter with Unknown Inputs without Direct Feedthrough (KF-UI-WDF) is applied on the obtained reduced differential model to estimate the source term which is the CBF scaled by a factor. Numerical results showing the performances of the adopted estimator are provided.

  13. Promoting Organ Donor Registries Through Public Education: What Is the Cost of Securing Organ Donors?

    Science.gov (United States)

    Razdan, Manik; Smith, Kenneth J; Bryce, Cindy L; Degenholtz, Howard B

    2016-06-01

    Transplant medicine's impact on America's public health is seriously limited by acute shortage of transplantable organs. Consequently, the United Sates has witnessed considerable investment in the promotion of organ donor registries. Although there is no evidence to support that donor registry promotion alleviates organ shortage, this belief continues to drive investments into registry promotion. In this study, return on investment in donor registry promotion was examined using cost-outcomes analysis. Cost of promoting the donor registry was estimated in US dollars whereas the outcome was measured as the number of individuals who join the registry (registrants) and their value in terms of organ donors. The study was conducted from the perspective of a regional Organ Procurement Organization (OPO). Costs were directly obtained from the OPO. The number of new registrants was obtained from the OPO and the departments of motor vehicles that maintain the donor registry. The value of registrants in terms of organ donors was computed based on a registrant's age-dependent risk of dying and age-dependent probability of becoming an organ donor. Six thousand seven hundred eight individuals joined the organ donor registry (95% confidence interval [95% CI], 5429-7956) at a cost of $455 per registrant (95% CI, US $383-US $562). These individuals result in 4.2 present-day donors (95% CI, 2.5-6.6) at a cost of US $726 000 (95% CI, US $462000-US $1.2 million). Because the cost per registrant and cost per donor is less than society's willingness to pay, donor registry promotion offers positive return on investment. Investment in registry promotion should at the minimum be maintained at current levels.

  14. An investigation on how to estimate future cash flows: Evidence from Tehran Stock Exchange

    Directory of Open Access Journals (Sweden)

    Roghayeh Ahmdi Panah Banad Koki

    2014-03-01

    Full Text Available This paper presents an empirical investigation to predict future cash flows using present cash flow and accruals using the information of 96 selected firms listed on Tehran Stock Exchange over the period 2007-2011. The proposed study uses linear regression techniques to forecast future cash flow and the results indicate that cash flow and accruals together could provide more power to forecast cash flow. In addition, accrual provides future cash flow better than cash flow. The survey also performs an investigation on discretionary accrual and finds that the firms with higher accruals maintain lower return compared with firms with lower return. This means there is a clear evidence of discretionary accruals on Tehran Stock Exchange.

  15. Donor Telomere Length SAA

    Science.gov (United States)

    A new NCI study has found that, among patients with severe aplastic anemia who received a hematopoietic cell transplant from an unrelated donor, those whose donor white blood cells had longer telomeres had higher survival rates five-years after transplant

  16. Systems of donor transfer

    NARCIS (Netherlands)

    F.T. de Charro (Frank); J.E.M. Akveld (Hans); E. Hessing (Ellen)

    1993-01-01

    textabstractThe development of medical knowledge has resulted in a demand in society for donor organs, but the recruitment of donor organs for transplantation is difficult. This paper aims to provide some general insights into the complex interaction processes involved. A laissez-faire policy, in

  17. A State-of-the-Art Review of the Sensor Location, Flow Observability, Estimation, and Prediction Problems in Traffic Networks

    Directory of Open Access Journals (Sweden)

    Enrique Castillo

    2015-01-01

    Full Text Available A state-of-the-art review of flow observability, estimation, and prediction problems in traffic networks is performed. Since mathematical optimization provides a general framework for all of them, an integrated approach is used to perform the analysis of these problems and consider them as different optimization problems whose data, variables, constraints, and objective functions are the main elements that characterize the problems proposed by different authors. For example, counted, scanned or “a priori” data are the most common data sources; conservation laws, flow nonnegativity, link capacity, flow definition, observation, flow propagation, and specific model requirements form the most common constraints; and least squares, likelihood, possible relative error, mean absolute relative error, and so forth constitute the bases for the objective functions or metrics. The high number of possible combinations of these elements justifies the existence of a wide collection of methods for analyzing static and dynamic situations.

  18. Proper orthogonal decomposition-based estimations of the flow field from particle image velocimetry wall-gradient measurements in the backward-facing step flow

    International Nuclear Information System (INIS)

    Nguyen, Thien Duy; Wells, John Craig; Mokhasi, Paritosh; Rempfer, Dietmar

    2010-01-01

    In this paper, particle image velocimetry (PIV) results from the recirculation zone of a backward-facing step flow, of which the Reynolds number is 2800 based on bulk velocity upstream of the step and step height (h = 16.5 mm), are used to demonstrate the capability of proper orthogonal decomposition (POD)-based measurement models. Three-component PIV velocity fields are decomposed by POD into a set of spatial basis functions and a set of temporal coefficients. The measurement models are built to relate the low-order POD coefficients, determined from an ensemble of 1050 PIV fields by the 'snapshot' method, to the time-resolved wall gradients, measured by a near-wall measurement technique called stereo interfacial PIV. These models are evaluated in terms of reconstruction and prediction of the low-order temporal POD coefficients of the velocity fields. In order to determine the estimation coefficients of the measurement models, linear stochastic estimation (LSE), quadratic stochastic estimation (QSE), principal component regression (PCR) and kernel ridge regression (KRR) are applied. We denote such approaches as LSE-POD, QSE-POD, PCR-POD and KRR-POD. In addition to comparing the accuracy of measurement models, we introduce multi-time POD-based estimations in which past and future information of the wall-gradient events is used separately or combined. The results show that the multi-time estimation approaches can improve the prediction process. Among these approaches, the proposed multi-time KRR-POD estimation with an optimized window of past wall-gradient information yields the best prediction. Such a multi-time KRR-POD approach offers a useful tool for real-time flow estimation of the velocity field based on wall-gradient data

  19. Estimation of respiratory heat flows in prediction of heat strain among Taiwanese steel workers.

    Science.gov (United States)

    Chen, Wang-Yi; Juang, Yow-Jer; Hsieh, Jung-Yu; Tsai, Perng-Jy; Chen, Chen-Peng

    2017-01-01

    International Organization for Standardization 7933 standard provides evaluation of required sweat rate (RSR) and predicted heat strain (PHS). This study examined and validated the approximations in these models estimating respiratory heat flows (RHFs) via convection (C res ) and evaporation (E res ) for application to Taiwanese foundry workers. The influence of change in RHF approximation to the validity of heat strain prediction in these models was also evaluated. The metabolic energy consumption and physiological quantities of these workers performing at different workloads under elevated wet-bulb globe temperature (30.3 ± 2.5 °C) were measured on-site and used in the calculation of RHFs and indices of heat strain. As the results show, the RSR model overestimated the C res for Taiwanese workers by approximately 3 % and underestimated the E res by 8 %. The C res approximation in the PHS model closely predicted the convective RHF, while the E res approximation over-predicted by 11 %. Linear regressions provided better fit in C res approximation (R 2  = 0.96) than in E res approximation (R 2  ≤ 0.85) in both models. The predicted C res deviated increasingly from the observed value when the WBGT reached 35 °C. The deviations of RHFs observed for the workers from those predicted using the RSR or PHS models did not significantly alter the heat loss via the skin, as the RHFs were in general of a level less than 5 % of the metabolic heat consumption. Validation of these approximations considering thermo-physiological responses of local workers is necessary for application in scenarios of significant heat exposure.

  20. An energy signature scheme for steam trap assessment and flow rate estimation using pipe-induced acoustic measurements

    Science.gov (United States)

    Olama, Mohammed M.; Allgood, Glenn O.; Kuruganti, Teja P.; Lake, Joe E.

    2012-06-01

    The US Congress has passed legislation dictating that all government agencies establish a plan and process for improving energy efficiencies at their sites. In response to this legislation, Oak Ridge National Laboratory (ORNL) has recently conducted a pilot study to explore the deployment of a wireless sensor system for a real-time measurement-based energy efficiency optimization framework within the steam distribution system within the ORNL campus. We make assessments on the real-time status of the distribution system by observing the state measurements of acoustic sensors mounted on the steam pipes/traps/valves. In this paper, we describe a spectral-based energy signature scheme that interprets acoustic vibration sensor data to estimate steam flow rates and assess steam traps health status. Experimental results show that the energy signature scheme has the potential to identify different steam trap health status and it has sufficient sensitivity to estimate steam flow rate. Moreover, results indicate a nearly quadratic relationship over the test region between the overall energy signature factor and flow rate in the pipe. The analysis based on estimated steam flow and steam trap status helps generate alerts that enable operators and maintenance personnel to take remedial action. The goal is to achieve significant energy-saving in steam lines by monitoring and acting on leaking steam pipes/traps/valves.

  1. Estimation on the Flow Phenomena and the Pressure Loss for the Inlet Part of a Research Reactor Vessel

    International Nuclear Information System (INIS)

    Seo, Kyoung Woo; Oh, Jae Min; Seo, Jae Kwang; Yoon, Ju Hyeon; Lee, Doo Jeong

    2009-01-01

    For a research reactor, a conceptual primary cooling system (PCS) was designed for an adequate cooling to the reactor core. The developed primary cooling circuit consisted of decay tanks, pumps, heat exchangers, vacuum breakers, some isolation and check valves, connection piping, and instruments. The main function of the primary cooling pumps (PCPs) of the PCS was to circulate the reactor coolant through the fuel core and the heat exchangers during a normal operation. The head according to the design flow rate which was determined by the thermal hydraulic design analysis for the core should be estimated to design the PCPs in the fluid system. The pressure loss in the PCS can be calculated by the dimensional analysis of the pipe flow and the head loss coefficient of the components. However, it is insufficient to estimate the pressure loss for 3-dimensional flow phenomena such as the flow path in the reactor with the theoretical dimensional analysis based on experimental data. The purpose of this research is to evaluate the pressure loss of the part of a research reactor vessel. For evaluating the pressure loss, the commercially available CFD computer model, FLUENT, was employed. First, for validating the application of FLUENT to the pressure loss, a simple case was calculated and compared with the Idelchik empirical correlation. Secondly, several cases for the inlet part of a research reactor vessel were estimated by a FLUENT 3- dimensional calculation

  2. Estimation of groundwater flow from temperature monitoring in a borehole heat exchanger during a thermal response test

    Science.gov (United States)

    Yoshioka, Mayumi; Takakura, Shinichi; Uchida, Youhei

    2018-05-01

    To estimate the groundwater flow around a borehole heat exchanger (BHE), thermal properties of geological core samples were measured and a thermal response test (TRT) was performed in the Tsukuba upland, Japan. The thermal properties were measured at 57 points along a 50-m-long geological core, consisting predominantly of sand, silt, and clay, drilled near the BHE. In this TRT, the vertical temperature in the BHE was also monitored during and after the test. Results for the thermal properties of the core samples and from the monitoring indicated that groundwater flow enhanced thermal transfers, especially at shallow depths. The groundwater velocities around the BHE were estimated using a two-dimensional numerical model with monitoring data on temperature changes. According to the results, the estimated groundwater velocity was generally consistent with hydrogeological data from previous studies, except for the data collected at shallow depths consisting of a clay layer. The reasons for this discrepancy at shallow depths were predicted to be preferential flow and the occurrence of vertical flow through the BHE grout, induced by the hydrogeological conditions.

  3. Estimation of water flow velocity in small plants using cold neutron imaging with D 2O tracer

    Science.gov (United States)

    Matsushima, U.; Herppich, W. B.; Kardjilov, N.; Graf, W.; Hilger, A.; Manke, I.

    2009-06-01

    Water flow imaging may help to better understand various problems related to water stress of plants. It may help to fully understand the water relations of plants. The objective of this research was to estimate the velocity of water flow in plant samples. Cut roses ( Rosa hybrida, var. 'Milva') were used as samples. Cold neutron radiography (CNR) was conducted at CONRAD, Helmholtz Center Berlin for Materials and Energy, Berlin, Germany. D 2O and H 2O were interchangeably injected into the water feeding system of the sample. After the uptake of D 2O, the neutron transmission increased due to the smaller attenuation coefficient of D 2O compared to H 2O. Replacement of D 2O in the rose peduncle was clearly observed. Three different optical flow algorithms, Block Matching, Horn-Schunck and Lucas-Kanade, were used to calculate the vector of D 2O tracer flow. The quality of sequential images providing sufficient spatial and temporal resolution allowed to estimate flow vector.

  4. Real time estimation of generation, extinction and flow of muscle fibre action potentials in high density surface EMG.

    Science.gov (United States)

    Mesin, Luca

    2015-02-01

    Developing a real time method to estimate generation, extinction and propagation of muscle fibre action potentials from bi-dimensional and high density surface electromyogram (EMG). A multi-frame generalization of an optical flow technique including a source term is considered. A model describing generation, extinction and propagation of action potentials is fit to epochs of surface EMG. The algorithm is tested on simulations of high density surface EMG (inter-electrode distance equal to 5mm) from finite length fibres generated using a multi-layer volume conductor model. The flow and source term estimated from interference EMG reflect the anatomy of the muscle, i.e. the direction of the fibres (2° of average estimation error) and the positions of innervation zone and tendons under the electrode grid (mean errors of about 1 and 2mm, respectively). The global conduction velocity of the action potentials from motor units under the detection system is also obtained from the estimated flow. The processing time is about 1 ms per channel for an epoch of EMG of duration 150 ms. A new real time image processing algorithm is proposed to investigate muscle anatomy and activity. Potential applications are proposed in prosthesis control, automatic detection of optimal channels for EMG index extraction and biofeedback. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Distance and velocity estimation using optical flow from a monocular camera

    NARCIS (Netherlands)

    Ho, H.W.; de Croon, G.C.H.E.; Chu, Q.

    2016-01-01

    Monocular vision is increasingly used in Micro Air Vehicles for navigation. In particular, optical flow, inspired by flying insects, is used to perceive vehicles’ movement with respect to the surroundings or sense changes in the environment. However, optical flow does not directly provide us the

  6. Distance and velocity estimation using optical flow from a monocular camera

    NARCIS (Netherlands)

    Ho, H.W.; de Croon, G.C.H.E.; Chu, Q.

    2017-01-01

    Monocular vision is increasingly used in micro air vehicles for navigation. In particular, optical flow, inspired by flying insects, is used to perceive vehicle movement with respect to the surroundings or sense changes in the environment. However, optical flow does not directly provide us the

  7. Estimates of the impacts of invasive alien plants on water flows in ...

    African Journals Online (AJOL)

    The adverse impacts of alien plant invasions on water flows have been a prime motivation for South Africa's Working for Water Programme. The approach used in this study builds on a previous national assessment in 1998 by incorporating factors that limit plant water-use, information from recent research and improved flow ...

  8. Estimation of Parameters and Flow Characteristics for the Design of Sanitary Sewers in Malaysia

    Directory of Open Access Journals (Sweden)

    Kamran Ansari

    2013-01-01

    Full Text Available Determination of the flow characteristics is very important for the design of sanitary sewers in any area. In the present study these are determined in the running sewers for the two parameters; per capita flow contribution and the peak flow factor. ISCO area - velocity flow meter model 4250 is used for this purpose. The flow meter, before being used in the running sewers, is calibrated first in the Hydraulics and Hydrology Laboratory of the UTM (Universiti Teknologi Malaysia. During the study the flow meter is installed inside the manhole in 10 different phases in the months of June, August, September, and October 2005 to monitor the sewage flow running in it. Continuous data is recorded in the flow meter during the process and the recorded time varies between 47 hours 25 minutes and 128 hours 35 minutes. The rainfall data is also collected during the same time using an automatic rain gauge which recorded rainfall at every five minutes of interval. Both the parameters thus calculated are then compared with the Malaysian Standard for sewer design i.e. MS 1228:1991. The results show that higher values of these parameters are being used in the design of sanitary sewers and extensive study needs to be carried out to review these values for future use

  9. Impact of flow routing on catchment area calculations, slope estimates, and numerical simulations of landscape development

    Science.gov (United States)

    Shelef, Eitan; Hilley, George E.

    2013-12-01

    Flow routing across real or modeled topography determines the modeled discharge and wetness index and thus plays a central role in predicting surface lowering rate, runoff generation, likelihood of slope failure, and transition from hillslope to channel forming processes. In this contribution, we compare commonly used flow-routing rules as well as a new routing rule, to commonly used benchmarks. We also compare results for different routing rules using Airborne Laser Swath Mapping (ALSM) topography to explore the impact of different flow-routing schemes on inferring the generation of saturation overland flow and the transition between hillslope to channel forming processes, as well as on location of saturation overland flow. Finally, we examined the impact of flow-routing and slope-calculation rules on modeled topography produced by Geomorphic Transport Law (GTL)-based simulations. We found that different rules produce substantive differences in the structure of the modeled topography and flow patterns over ALSM data. Our results highlight the impact of flow-routing and slope-calculation rules on modeled topography, as well as on calculated geomorphic metrics across real landscapes. As such, studies that use a variety of routing rules to analyze and simulate topography are necessary to determine those aspects that most strongly depend on a chosen routing rule.

  10. Correlation dimension estimate and its potential use in analysis of gas-solid flows

    DEFF Research Database (Denmark)

    Yin, Chungen; Rosendahl, Lasse Aistrup; Kær, Søren Knudsen

    2005-01-01

    Gas-solid flows are nonlinear systems. Therefore state-space analysis, a tool developed within the framework of nonlinear dynamics, could provide more useful insights into complex gas-solid flows. One of the positive aspects of state-space analysis is that the major properties of a system can be ...

  11. Estimation of flow stress of radiation induced F/M steels using molecular dynamics and discrete dislocation dynamics approach

    International Nuclear Information System (INIS)

    More, Ameya; Dutta, B.K.; Durgaprasad, P.V.; Arya, A.K.

    2012-01-01

    Fe-Cr based Ferritic/Martensitic (F/M) steels are the candidate structural materials for future fusion reactors. In this work, a multi-scale approach comprising atomistic Molecular Dynamics (MD) simulations and Discrete Dislocation Dynamics (DDD) simulations are used to model the effect of irradiation dose on the flow stress of F/M steels. At the atomic scale, molecular dynamics simulations are used to study the dislocation interaction with irradiation induced defects, i.e. voids and He bubbles. Whereas, the DDD simulations are used to estimate the change in flow stress of the material as a result of irradiation hardening. (author)

  12. New model and field data on estimates of Antarctic Bottom Water flow through the deep Vema Channel

    Science.gov (United States)

    Frey, D. I.; Fomin, V. V.; Diansky, N. A.; Morozov, E. G.; Neiman, V. G.

    2017-05-01

    We used a numerical model of the ocean circulation with a high spatial resolution to obtain estimates of the kinematic characteristics of Antarctic Bottom Water flow through the abyssal Vema Channel in the southwestern part of the Atlantic Ocean. The results of simulations correspond to the data of direct velocity measurements made at several locations in the channel. The high horizontal and vertical resolution of the model in the bottom layer allowed us to study in detail the hydrodynamics of this flow over its entire length.

  13. Preliminary Estimation of Local Bypass Flow Gap Sizes for a Prismatic VHTR Core

    International Nuclear Information System (INIS)

    Kim, Min Hwan; Jo, Chang Keun; Lee, Won Jae

    2009-01-01

    The Very High Temperature Reactor (VHTR) has been selected for the Nuclear Hydrogen Development and Demonstration (NHDD) project. In the VHTR design, core bypass flow has been one of key issues for core thermal margins and target temperature of the core outlet. The core bypass flow in the prismatic VHTR varies with the core life due to the irradiation shrinkage/ swelling and thermal expansion of the graphite blocks, which could be a significant proportion of the total core flow. Thus, accurate prediction of the bypass flow is of major importance in assuring the core thermal margin. To predict the bypass flow, first of all, local gap sizes between graphite blocks in the core should be determined. The objectives of this work are to develop a methodology for determining the gap sizes and to perform a preliminary evaluation for a reference reactor

  14. The effect of whole-blood donor adverse events on blood donor return rates.

    Science.gov (United States)

    Newman, Bruce H; Newman, Daniel T; Ahmad, Raffat; Roth, Arthur J

    2006-08-01

    Some blood donation-related adverse events (AEs) can negatively impact the blood donor return rate (BDRR) and decrease donor retention. One-thousand randomly selected whole-blood donors were interviewed 3 weeks after a 525-mL index whole-blood donation for seven AEs. The number of return visits and duration of follow-up were recorded for each of the 1000 donors. A negative binomial regression analysis was used to determine the contribution of the four most common AEs to the BDRR, and interactions between these AEs were also evaluated. The four most common AEs were bruise alone (15.1%), sore arm "alone" (7.0%), fatigue "alone" (5.1%), and donor reaction "alone" (4.2%), where "alone" is defined to also include donors who had a bruise but no other AE. The estimated BDRR for donations without AEs was 1.32 visits per year. The estimated BDRRs for the four most common AEs were: bruise alone, 1.32 visits per year; sore arm alone, 1.30 visits per year (2% reduction in BDRR); fatigue alone, 1.06 visits per year (20% reduction in BDRR); and donor reaction alone, 0.87 visits per year (34% reduction in BDRR). The BDRR for donor reaction, fatigue, and sore arm together was 0.20 visits per year (85% reduction in BDRR). Donor reaction had the most negative impact on the BDRR. There appears to be a synergistic effect between donor reaction, fatigue, and sore arm. Theoretically, amelioration of some AEs has the potential to improve BDRRs.

  15. Marginal kidney donor

    Directory of Open Access Journals (Sweden)

    Ganesh Gopalakrishnan

    2007-01-01

    Full Text Available Renal transplantation is the treatment of choice for a medically eligible patient with end stage renal disease. The number of renal transplants has increased rapidly over the last two decades. However, the demand for organs has increased even more. This disparity between the availability of organs and waitlisted patients for transplants has forced many transplant centers across the world to use marginal kidneys and donors. We performed a Medline search to establish the current status of marginal kidney donors in the world. Transplant programs using marginal deceased renal grafts is well established. The focus is now on efforts to improve their results. Utilization of non-heart-beating donors is still in a plateau phase and comprises a minor percentage of deceased donations. The main concern is primary non-function of the renal graft apart from legal and ethical issues. Transplants with living donors outnumbered cadaveric transplants at many centers in the last decade. There has been an increased use of marginal living kidney donors with some acceptable medical risks. Our primary concern is the safety of the living donor. There is not enough scientific data available to quantify the risks involved for such donation. The definition of marginal living donor is still not clear and there are no uniform recommendations. The decision must be tailored to each donor who in turn should be actively involved at all levels of the decision-making process. In the current circumstances, our responsibility is very crucial in making decisions for either accepting or rejecting a marginal living donor.

  16. Estimated probability of postwildfire debris flows in the 2012 Whitewater-Baldy Fire burn area, southwestern New Mexico

    Science.gov (United States)

    Tillery, Anne C.; Matherne, Anne Marie; Verdin, Kristine L.

    2012-01-01

    In May and June 2012, the Whitewater-Baldy Fire burned approximately 1,200 square kilometers (300,000 acres) of the Gila National Forest, in southwestern New Mexico. The burned landscape is now at risk of damage from postwildfire erosion, such as that caused by debris flows and flash floods. This report presents a preliminary hazard assessment of the debris-flow potential from 128 basins burned by the Whitewater-Baldy Fire. A pair of empirical hazard-assessment models developed by using data from recently burned basins throughout the intermountain Western United States was used to estimate the probability of debris-flow occurrence and volume of debris flows along the burned area drainage network and for selected drainage basins within the burned area. The models incorporate measures of areal burned extent and severity, topography, soils, and storm rainfall intensity to estimate the probability and volume of debris flows following the fire. In response to the 2-year-recurrence, 30-minute-duration rainfall, modeling indicated that four basins have high probabilities of debris-flow occurrence (greater than or equal to 80 percent). For the 10-year-recurrence, 30-minute-duration rainfall, an additional 14 basins are included, and for the 25-year-recurrence, 30-minute-duration rainfall, an additional eight basins, 20 percent of the total, have high probabilities of debris-flow occurrence. In addition, probability analysis along the stream segments can identify specific reaches of greatest concern for debris flows within a basin. Basins with a high probability of debris-flow occurrence were concentrated in the west and central parts of the burned area, including tributaries to Whitewater Creek, Mineral Creek, and Willow Creek. Estimated debris-flow volumes ranged from about 3,000-4,000 cubic meters (m3) to greater than 500,000 m3 for all design storms modeled. Drainage basins with estimated volumes greater than 500,000 m3 included tributaries to Whitewater Creek, Willow

  17. Adverse Reactions in Allogeneic Blood Donors: A Tertiary Care Experience from a Developing Country

    OpenAIRE

    Sultan, Sadia; Baig, Mohammad Amjad; Irfan, Syed Mohammed; Ahmed, Syed Ijlal; Hasan, Syeda Faiza

    2016-01-01

    Objectives: Fragmented blood transfusion services along with an unmotivated blood donation culture often leads to blood shortage. Donor retention is crucial to meet the increasing blood demand, and adverse donor reactions have a negative impact on donor return. The aim of this study was to estimate adverse donor reactions and identify any demographic association.   Methods: We conducted a prospective study between January 2011 and December 2013. A total of 41,759 healthy donors were enrol...

  18. Optimal estimation of spatially variable recharge and transmissivity fields under steady-state groundwater flow. Part 2. Case study

    Science.gov (United States)

    Graham, Wendy D.; Neff, Christina R.

    1994-05-01

    The first-order analytical solution of the inverse problem for estimating spatially variable recharge and transmissivity under steady-state groundwater flow, developed in Part 1 is applied to the Upper Floridan Aquifer in NE Florida. Parameters characterizing the statistical structure of the log-transmissivity and head fields are estimated from 152 measurements of transmissivity and 146 measurements of hydraulic head available in the study region. Optimal estimates of the recharge, transmissivity and head fields are produced throughout the study region by conditioning on the nearest 10 available transmissivity measurements and the nearest 10 available head measurements. Head observations are shown to provide valuable information for estimating both the transmissivity and the recharge fields. Accurate numerical groundwater model predictions of the aquifer flow system are obtained using the optimal transmissivity and recharge fields as input parameters, and the optimal head field to define boundary conditions. For this case study, both the transmissivity field and the uncertainty of the transmissivity field prediction are poorly estimated, when the effects of random recharge are neglected.

  19. Estimation of groundwater consumption by phreatophytes using diurnal water table fluctuations: A saturated‐unsaturated flow assessment

    Science.gov (United States)

    Loheide, Steven P.; Butler, James J.; Gorelick, Steven M.

    2005-01-01

    Groundwater consumption by phreatophytes is a difficult‐to‐measure but important component of the water budget in many arid and semiarid environments. Over the past 70 years the consumptive use of groundwater by phreatophytes has been estimated using a method that analyzes diurnal trends in hydrographs from wells that are screened across the water table (White, 1932). The reliability of estimates obtained with this approach has never been rigorously evaluated using saturated‐unsaturated flow simulation. We present such an evaluation for common flow geometries and a range of hydraulic properties. Results indicate that the major source of error in the White method is the uncertainty in the estimate of specific yield. Evapotranspirative consumption of groundwater will often be significantly overpredicted with the White method if the effects of drainage time and the depth to the water table on specific yield are ignored. We utilize the concept of readily available specific yield as the basis for estimation of the specific yield value appropriate for use with the White method. Guidelines are defined for estimating readily available specific yield based on sediment texture. Use of these guidelines with the White method should enable the evapotranspirative consumption of groundwater to be more accurately quantified.

  20. Estimation of intersubject variability of cerebral blood flow measurements using MRI and positron emission tomography

    DEFF Research Database (Denmark)

    Henriksen, Otto Mølby; Larsson, Henrik B W; Hansen, Adam E

    2012-01-01

    PURPOSE: To investigate the within and between subject variability of quantitative cerebral blood flow (CBF) measurements in normal subjects using various MRI techniques and positron emission tomography (PET). MATERIALS AND METHODS: Repeated CBF measurements were performed in 17 healthy, young...

  1. Modeling Flow Rate to Estimate Hydraulic Conductivity in a Parabolic Ceramic Water Filter

    Directory of Open Access Journals (Sweden)

    Ileana Wald

    2012-01-01

    Full Text Available In this project we model volumetric flow rate through a parabolic ceramic water filter (CWF to determine how quickly it can process water while still improving its quality. The volumetric flow rate is dependent upon the pore size of the filter, the surface area, and the height of water in the filter (hydraulic head. We derive differential equations governing this flow from the conservation of mass principle and Darcy's Law and find the flow rate with respect to time. We then use methods of calculus to find optimal specifications for the filter. This work is related to the research conducted in Dr. James R. Mihelcic's Civil and Environmental Engineering Lab at USF.

  2. National Marrow Donor Program

    National Research Council Canada - National Science Library

    Setterholm, Michelle

    2008-01-01

    ... a nationwide contingency response plan. 2. Rapid Identification of Matched Donors : Increase operational efficiencies that accelerate the search process and increase patient access are key to preparedness in a contingency event. pa 3...

  3. ACFAC: a cash flow analysis code for estimating product price from an industrial operation

    International Nuclear Information System (INIS)

    Delene, J.G.

    1980-04-01

    A computer code is presented which uses a discountted cash flow methodology to obtain an average product price for an industtrial process. The general discounted cash flow method is discussed. Special code options include multiple treatments of interest during construction and other preoperational costs, investment tax credits, and different methods for tax depreciation of capital assets. Two options for allocating the cost of plant decommissioning are available. The FORTRAN code listing and the computer output for a sample problem are included

  4. Thermodilution versus inert gas rebreathing for estimation of effective pulmonary blood flow

    DEFF Research Database (Denmark)

    Christensen, P; Clemensen, P; Andersen, P K

    2000-01-01

    To compare measurements of the effective pulmonary blood flow (Qep, i.e., nonshunted fraction of cardiac output, Qt) by the inert gas rebreathing (RB) method and the thermodilution (TD) technique in critically ill patients.......To compare measurements of the effective pulmonary blood flow (Qep, i.e., nonshunted fraction of cardiac output, Qt) by the inert gas rebreathing (RB) method and the thermodilution (TD) technique in critically ill patients....

  5. Water flow in bedrock; estimation of influence of transmissive shaft and borehole

    International Nuclear Information System (INIS)

    Andersson, L.; Neretnieks, J.; Rasmuson, A.

    1983-01-01

    The bedrock, a system of large and small fractures that permit water transport through the rock mass. The water content of the bedrock can, under varying hydrostatic pressure conditions, give rise to different flow patterns via boreholes or shafts drilled through the rock. A case is dealt with where a borehole connects a low point in the terrain with a point in the repository where the hydrostatic pressure is higher than at the mouth of the borehole. The situation may be conceived as having arisen when the area was investigated and a hole was drilled at an angle down from the valley to a point below the high point in the area. If the borehole is not sealed, an artesian well may be created. The conductivity used, 2 times 10- 9 m/s, presumes that the repository has been emplaced in average quality rock at this depth. In reality, the repository site will be selected where the rock is better than average. In reality, a shaft - even if it is imperfectly backfilled - or a borehole exerts a flow resistance that reduces the available pressure difference at a depth of 500 m. Taken together, these factors indicate that approx. 5 m 3 /(year, 5 m) is the water flow that can be expected to emerge from the repository through a shaft or a borehole. Only this flow can have been contaminated with escaping substances from the repository area. Water that flows in from other parts of the hole dilutes this flow considerably. (G.B.)

  6. A pilot study of the relationship between Doppler-estimated carotid and brachial artery flow and cardiac index.

    Science.gov (United States)

    Weber, U; Glassford, N J; Eastwood, G M; Bellomo, R; Hilton, A K

    2015-10-01

    We measured carotid and brachial artery blood flow by Doppler ultrasound in 11 human volunteers, and related these to cardiac index and to each other. The median (IQR [range]) carotid arterial blood flow was 0.334 (0.223-0.381 [0.052-0.563]) l.min(-1) on the right and 0.315 (0.223-0.369 [0.061-0.690]) l.min(-1) on the left. The brachial arterial blood flow was 0.049 (0.033-0.062 [0.015-0.204]) l.min(-1) on the right and 0.039 (0.027-0.054 [0.011-0.116]) on the left. Cardiac index was 3.2 (2.8-3.5 [1.9-5.4]) l.min(-1) .m(-2) . There was a moderate to good correlation between right-and left-sided flows (brachial: ρ = 0.45; carotid: ρ = 0.567). Brachial and carotid flow had no or a negative correlation with cardiac index (right brachial: ρ = -0.145, left brachial: ρ = -0.349; right carotid: ρ = -0.376, left carotid: ρ = -0.285). In contrast to some previous studies, we found that Doppler-estimated peripheral arterial blood flows only show a weak correlation with cardiac index and cannot be used to provide non-invasive estimates of cardiac index in man. © 2015 The Association of Anaesthetists of Great Britain and Ireland.

  7. Realtime estimation of city gas pipe network damage by lateral flow of liquefied ground behind quay walls

    Energy Technology Data Exchange (ETDEWEB)

    Ishida, E.; Isoyama, R. [Japan Engineering Consultants Co., Ltd., Tokyo (Japan). Public Management Research Center; Koganemaru, K.; Shimuzu, Y. [Tokyo Gas Co. Ltd., Tokyo (Japan). Center for Disaster Management and Supply Control; Morimoto, I. [Kiso-Jiban Consultants Co. Ltd., Tokyo (Japan); Yasuda, S. [Tokyo Denki Univ., Tokyo (Japan). Dept. of Civil and Environmental Engineering

    2004-07-01

    Estimating the degree of damage to city gas pipe networks is difficult because of the lack of damage case data. This paper proposes a method for calculating the amount of earthquake-induced ground displacement at pipe node locations by constructing ground models. Data for the models was obtained from boreholes and by using a simple ground flow formula. The analysis method will make it possible to calculate the allowable limits of damage-causing factors such as ground motion and flow for different pipe network elements. The analysis procedure was conducted using a 2-dimensional liquefaction-induced flow analysis program finite element method. A real time damage estimation system for low pressure gas pipes uses ground motions having a design seismic coefficient of 0.4 in preparing strong earthquake liquefied layer thickness distribution data. Flow calculations were presented as well as a ground revetment database to replace node location data. It was concluded that achieving consistency was desirable. 7 refs., 2 tabs., 5 figs.

  8. Towards breaking the spatial resolution barriers: An optical flow and super-resolution approach for sea ice motion estimation

    Science.gov (United States)

    Petrou, Zisis I.; Xian, Yang; Tian, YingLi

    2018-04-01

    Estimation of sea ice motion at fine scales is important for a number of regional and local level applications, including modeling of sea ice distribution, ocean-atmosphere and climate dynamics, as well as safe navigation and sea operations. In this study, we propose an optical flow and super-resolution approach to accurately estimate motion from remote sensing images at a higher spatial resolution than the original data. First, an external example learning-based super-resolution method is applied on the original images to generate higher resolution versions. Then, an optical flow approach is applied on the higher resolution images, identifying sparse correspondences and interpolating them to extract a dense motion vector field with continuous values and subpixel accuracies. Our proposed approach is successfully evaluated on passive microwave, optical, and Synthetic Aperture Radar data, proving appropriate for multi-sensor applications and different spatial resolutions. The approach estimates motion with similar or higher accuracy than the original data, while increasing the spatial resolution of up to eight times. In addition, the adopted optical flow component outperforms a state-of-the-art pattern matching method. Overall, the proposed approach results in accurate motion vectors with unprecedented spatial resolutions of up to 1.5 km for passive microwave data covering the entire Arctic and 20 m for radar data, and proves promising for numerous scientific and operational applications.

  9. Application of the extended Kalman filtering for the estimation of core coolant flow rate in pressurized water reactors

    International Nuclear Information System (INIS)

    Shieh, D.J.; Upadhyaya, B.R.

    1986-01-01

    In-core neutron detector and core-exit temperature signals in a pressurized water reactor (PWR) satisfy the condition of observability of the core dynamic system, and can be used to estimate nonmeasurable state variables and model parameters. The extension of the Kalman filtering technique is very useful for direct parameter estimation. This approach is applied to the determination of core coolant mass flow rate in PWRs and is evaluated using in-core measurements at the Loss-of-Fluid Test (LOFT) reactor. The influence of model uncertainties on the estimation accuracy was studied using the ambiguity function analysis. A sequential discretization method was developed to achieve faster convergence to the true value, avoiding model discretization at each sample point. The performance of the extended Kalman filter and the computational innovations were evaluated using a reduced order core dynamic model of the LOFT reactor and random data simulation. The technique was then applied to the determination of LOFT core coolant flow rate from operational data at 100% and 65% flow conditions

  10. Adaptive estimation of state of charge and capacity with online identified battery model for vanadium redox flow battery

    Science.gov (United States)

    Wei, Zhongbao; Tseng, King Jet; Wai, Nyunt; Lim, Tuti Mariana; Skyllas-Kazacos, Maria

    2016-11-01

    Reliable state estimate depends largely on an accurate battery model. However, the parameters of battery model are time varying with operating condition variation and battery aging. The existing co-estimation methods address the model uncertainty by integrating the online model identification with state estimate and have shown improved accuracy. However, the cross interference may arise from the integrated framework to compromise numerical stability and accuracy. Thus this paper proposes the decoupling of model identification and state estimate to eliminate the possibility of cross interference. The model parameters are online adapted with the recursive least squares (RLS) method, based on which a novel joint estimator based on extended Kalman Filter (EKF) is formulated to estimate the state of charge (SOC) and capacity concurrently. The proposed joint estimator effectively compresses the filter order which leads to substantial improvement in the computational efficiency and numerical stability. Lab scale experiment on vanadium redox flow battery shows that the proposed method is highly authentic with good robustness to varying operating conditions and battery aging. The proposed method is further compared with some existing methods and shown to be superior in terms of accuracy, convergence speed, and computational cost.

  11. Estimation of shear stress in counter-current gas-liquid annular two-phase flow

    International Nuclear Information System (INIS)

    Abe, Yutaka; Akimoto, Hajime; Murao, Yoshio

    1991-01-01

    The accuracy of the correlations of the friction factor is important for the counter-current flow (CCF) analysis with two-fluid model. However, existing two fluid model codes use the correlations of friction factors for co-current flow or correlation developed based on the assumption of no wall shear stress. The assessment calculation for two fluid model code with those existing correlations of friction factors shows the falling water flow rate is overestimated. Analytical model is developed to calculate the shear stress distribution in water film at CCF in order to get the information on the shear stress at the interface and the wall. The analytical results with the analysis model and Bharathan's CCF data shows that the wall shear stress acting on the falling water film is almost same order as the interfacial shear stress and the correlations for co-current flow cannot be applied to the counter-current flow. Tentative correlations of the interfacial and the wall friction factors are developed based on the results of the present study. (author)

  12. Estimation of flows cavitation by similarity test: application to the couple water/liquid sodium

    International Nuclear Information System (INIS)

    Espanet, Laurent

    2000-01-01

    In many industrial flows, it is necessary to perform a similarity test to assess the cavitation intensity. The similarity laws must take into account the physical properties of the two fluids and especially the surface tension. To obtain such laws, a continuous description of the two-phase flow has been used. The non linear model of Cahn and Hilliard allows to obtain the equations of motion for these fluids, and non-dimensional conditions yield to the similarity laws. This method has been checked experimentally by achieving two different flows through a diaphragm. When respecting the similarity laws, the comparison of these flows allows to validate the transposition laws and to determine their associated tolerance. At last, the number of dusts and particles is an important parameter for cavitation inception threshold since it leads to the number of bubbles. Using the Laplace theory, it is shown that for each value of flow rate, it exists an upper bound value for the bubble density, which allows to establish a similarity law concerning this number of bubbles. (author) [fr

  13. Individual, contextual and network characteristics of blood donors and non-donors: a systematic review of recent literature

    NARCIS (Netherlands)

    Piersma, Tjeerd W.; Bekkers, René; Klinkenberg, Elisabeth F.; de Kort, Wim L. A. M.; Merz, Eva-Maria

    2017-01-01

    Background. The ageing population and recent migration flows may negatively affect the blood supply in the long term, increasing the importance of targeted recruitment and retention strategies to address donors. This review sought to identify individual, network and contextual characteristics

  14. Dominant root locus in state estimator design for material flow processes: A case study of hot strip rolling.

    Science.gov (United States)

    Fišer, Jaromír; Zítek, Pavel; Skopec, Pavel; Knobloch, Jan; Vyhlídal, Tomáš

    2017-05-01

    The purpose of the paper is to achieve a constrained estimation of process state variables using the anisochronic state observer tuned by the dominant root locus technique. The anisochronic state observer is based on the state-space time delay model of the process. Moreover the process model is identified not only as delayed but also as non-linear. This model is developed to describe a material flow process. The root locus technique combined with the magnitude optimum method is utilized to investigate the estimation process. Resulting dominant roots location serves as a measure of estimation process performance. The higher the dominant (natural) frequency in the leftmost position of the complex plane the more enhanced performance with good robustness is achieved. Also the model based observer control methodology for material flow processes is provided by means of the separation principle. For demonstration purposes, the computer-based anisochronic state observer is applied to the strip temperatures estimation in the hot strip finishing mill composed of seven stands. This application was the original motivation to the presented research. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  15. Estimating the Risk of River Flow under Climate Change in the Tsengwen River Basin

    Directory of Open Access Journals (Sweden)

    Hsiao-Ping Wei

    2016-03-01

    Full Text Available This study evaluated the overflow risk of the Tsengwen River under a climate change scenario by using bias-corrected dynamic downscaled data as inputs for a SOBEK model (Deltares, the Netherlands. The results showed that the simulated river flow rate at Yufeng Bridge (upstream, Erxi Bridge (midstream, and XinZong (1 (downstream stations are at risk of exceeding the management plan’s flow rate for three projection periods (1979–2003, 2015–2039, 2075–2099. After validation with the geomorphic and hydrological data collected in this study, the frequency at which the flow rate exceeded the design flood was 2 in 88 events in the base period (1979–2003, 6 in 82 events in the near future (2015–2039, and 10 in 81 events at the end of the century (2075–2099.

  16. An integrated model for reliability estimation of digital nuclear protection system based on fault tree and software control flow methodologies

    International Nuclear Information System (INIS)

    Kim, Man Cheol; Seong, Poong Hyun

    2000-01-01

    In the nuclear industry, the difficulty of proving the reliabilities of digital systems prohibits the widespread use of digital systems in various nuclear application such as plant protection system. Even though there exist a few models which are used to estimate the reliabilities of digital systems, we develop a new integrated model which is more realistic than the existing models. We divide the process of estimating the reliability of a digital system into two phases, a high-level phase and a low-level phase, and the boundary of two phases is the reliabilities of subsystems. We apply software control flow method to the low-level phase and fault tree analysis to the high-level phase. The application of the model to Dynamic Safety System(DDS) shows that the estimated reliability of the system is quite reasonable and realistic

  17. Optimal estimation of spatially variable recharge and transmissivity fields under steady-state groundwater flow. Part 1. Theory

    Science.gov (United States)

    Graham, Wendy D.; Tankersley, Claude D.

    1994-05-01

    Stochastic methods are used to analyze two-dimensional steady groundwater flow subject to spatially variable recharge and transmissivity. Approximate partial differential equations are developed for the covariances and cross-covariances between the random head, transmissivity and recharge fields. Closed-form solutions of these equations are obtained using Fourier transform techniques. The resulting covariances and cross-covariances can be incorporated into a Bayesian conditioning procedure which provides optimal estimates of the recharge, transmissivity and head fields given available measurements of any or all of these random fields. Results show that head measurements contain valuable information for estimating the random recharge field. However, when recharge is treated as a spatially variable random field, the value of head measurements for estimating the transmissivity field can be reduced considerably. In a companion paper, the method is applied to a case study of the Upper Floridan Aquifer in NE Florida.

  18. An integrated model for reliability estimation of digital nuclear protection system based on fault tree and software control flow methodologies

    International Nuclear Information System (INIS)

    Kim, Man Cheol; Seong, Poong Hyun

    2000-01-01

    In nuclear industry, the difficulty of proving the reliabilities of digital systems prohibits the widespread use of digital systems in various nuclear application such as plant protection system. Even though there exist a few models which are used to estimate the reliabilities of digital systems, we develop a new integrated model which is more realistic than the existing models. We divide the process of estimating the reliability of a digital system into two phases, a high-level phase and a low-level phase, and the boundary of two phases is the reliabilities of subsystems. We apply software control flow method to the low-level phase and fault tree analysis to the high-level phase. The application of the model of dynamic safety system (DSS) shows that the estimated reliability of the system is quite reasonable and realistic. (author)

  19. Improvement of Estimation method for two-phase flow in a large-diameter pipe. Pt. 4. Effect of the inlet boundary condition of the upward flow section on flow characteristics

    International Nuclear Information System (INIS)

    Yoneda, Kimitoshi; Okawa, Tomio; Zhou, Shirong

    1999-01-01

    In nuclear power plants, many large-diameter pipes are subject to gas-liquid two-phase flow. For rational design and performance estimation, the flow in the pipes should be predicted accurately. With the correlation used at present, however, the flow analysis can not reach desirable precision. This is partly due to the lack of understanding of the two-phase flow characteristics in large-diameter pipes. Therefore, steam-water two-phase flow in a vertical pipe (155 mm i.d.) was investigated empirically. Lateral distribution data of phase volume fraction, gas velocity and bubble diameter were obtained. The effects of the inlet boundary condition were also observed. The drift velocity in the developing region was considerably affected by the inlet boundary condition. By deriving the correlation of mean bubble diameter as a function of void fraction and pressure, the empirical data was predicted with high accuracy compared with the existing correlation used in best-estimate codes of nuclear reactor safety analysis. (author)

  20. Estimation of vessel diameter and blood flow dynamics from laser speckle images

    DEFF Research Database (Denmark)

    Postnov, Dmitry D.; Tuchin, Valery V.; Sosnovtseva, Olga

    2016-01-01

    Laser speckle imaging is a rapidly developing method to study changes of blood velocity in the vascular networks. However, to assess blood flow and vascular responses it is crucial to measure vessel diameter in addition to blood velocity dynamics. We suggest an algorithm that allows for dynamical...

  1. Implementation of unscented transform to estimate the uncertainty of a liquid flow standard system

    Energy Technology Data Exchange (ETDEWEB)

    Chun, Sejong; Choi, Hae-Man; Yoon, Byung-Ro; Kang, Woong [Korea Research Institute of Standards and Science, Daejeon (Korea, Republic of)

    2017-03-15

    First-order partial derivatives of a mathematical model are an essential part of evaluating the measurement uncertainty of a liquid flow standard system according to the Guide to the expression of uncertainty in measurement (GUM). Although the GUM provides a straightforward method to evaluate the measurement uncertainty of volume flow rate, the first-order partial derivatives can be complicated. The mathematical model of volume flow rate in a liquid flow standard system has a cross-correlation between liquid density and buoyancy correction factor. This cross-correlation can make derivation of the first-order partial derivatives difficult. Monte Carlo simulation can be used as an alternative method to circumvent the difficulty in partial derivation. However, the Monte Carlo simulation requires large computational resources for a correct simulation because it considers the completeness issue whether an ideal or a real operator conducts an experiment to evaluate the measurement uncertainty. Thus, the Monte Carlo simulation needs a large number of samples to ensure that the uncertainty evaluation is as close to the GUM as possible. Unscented transform can alleviate this problem because unscented transform can be regarded as a Monte Carlo simulation with an infinite number of samples. This idea means that unscented transform considers the uncertainty evaluation with respect to the ideal operator. Thus, unscented transform can evaluate the measurement uncertainty the same as the uncertainty that the GUM provides.

  2. Debris flows risk analysis and direct loss estimation: the case study of Valtellina di Tirano, Italy

    Czech Academy of Sciences Publication Activity Database

    Blahůt, Jan; Glade, T.; Sterlacchini, S.

    2014-01-01

    Roč. 11, č. 2 (2014), s. 288-307 ISSN 1672-6316 Institutional support: RVO:67985891 Keywords : Debris flows * Risk analysis * Economic losses * Central Alps * Italy Subject RIV: DE - Earth Magnetism, Geodesy, Geography OBOR OECD: Physical geography Impact factor: 0.963, year: 2014

  3. Generalized Adaptive Smoothing Method for State Estimation of Generic Two-Dimensional Flows

    NARCIS (Netherlands)

    Yuan, Y.; Hoogendoorn, S.P.

    2016-01-01

    In big cities, the proportion of slow-mode (such as pedestrian) flows in total trip demand is steadily growing every year. Along with this trend, many concerns arise about accessibility and safety. The monitoring and the management of pedestrians serve as a potential solution to maintain the

  4. Granger causality estimate of information flow in temperature fields is consistent with wind direction

    Czech Academy of Sciences Publication Activity Database

    Jajcay, Nikola; Hlinka, Jaroslav; Hartman, David; Paluš, Milan

    2014-01-01

    Roč. 16, - (2014), EGU2014-12768 ISSN 1607-7962. [EGU General Assembly /11./. 27.04.2014-02.05.2014, Vienna] Institutional support: RVO:67985807 Keywords : Granger causality * climate * information flow * surface air temperature * wind Subject RIV: BB - Applied Statistics, Operational Research

  5. Evaluation of an ion adsorption method to estimate intragravel flow velocity in salmonid spawning gravels

    Science.gov (United States)

    James L. Clayton; John G. King; Russell F. Thurow

    1996-01-01

    Intragravel water exchange provides oxygenated water, removes metabolic waste, and is an essential factor in salmonid embryo survival. Measurements of intragravel flow velocity have been suggested as an index of gravel quality and also as a useful predictor of fry emergence; however, proposed methods for measuring velocity in gravel are problematic. We evaluate an ion...

  6. Investigating the Potential of Activity Tracking App Data to Estimate Cycle Flows in Urban Areas

    Science.gov (United States)

    Haworth, J.

    2016-06-01

    Traffic congestion and its associated environmental effects pose a significant problem for large cities. Consequently, promoting and investing in green travel modes such as cycling is high on the agenda for many transport authorities. In order to target investment in cycling infrastructure and improve the experience of cyclists on the road, it is important to know where they are. Unfortunately, investment in intelligent transportation systems over the years has mainly focussed on monitoring vehicular traffic, and comparatively little is known about where cyclists are on a day to day basis. In London, for example, there are a limited number of automatic cycle counters installed on the network, which provide only part of the picture. These are supplemented by surveys that are carried out infrequently. Activity tracking apps on smart phones and GPS devices such as Strava have become very popular over recent years. Their intended use is to track physical activity and monitor training. However, many people routinely use such apps to record their daily commutes by bicycle. At the aggregate level, these data provide a potentially rich source of information about the movement and behaviour of cyclists. Before such data can be relied upon, however, it is necessary to examine their representativeness and understand their potential biases. In this study, the flows obtained from Strava Metro (SM) are compared with those obtained during the 2013 London Cycle Census (LCC). A set of linear regression models are constructed to predict LCC flows using SM flows along with a number of dummy variables including road type, hour of day, day of week and presence/absence of cycle lane. Cross-validation is used to test the fitted models on unseen LCC sites. SM flows are found to be a statistically significant (p<0.0001) predictor of total flows as measured by the LCC and the models yield R squared statistics of ~0.7 before considering spatio-temporal variation. The initial results indicate

  7. INVESTIGATING THE POTENTIAL OF ACTIVITY TRACKING APP DATA TO ESTIMATE CYCLE FLOWS IN URBAN AREAS

    Directory of Open Access Journals (Sweden)

    J. Haworth

    2016-06-01

    Full Text Available Traffic congestion and its associated environmental effects pose a significant problem for large cities. Consequently, promoting and investing in green travel modes such as cycling is high on the agenda for many transport authorities. In order to target investment in cycling infrastructure and improve the experience of cyclists on the road, it is important to know where they are. Unfortunately, investment in intelligent transportation systems over the years has mainly focussed on monitoring vehicular traffic, and comparatively little is known about where cyclists are on a day to day basis. In London, for example, there are a limited number of automatic cycle counters installed on the network, which provide only part of the picture. These are supplemented by surveys that are carried out infrequently. Activity tracking apps on smart phones and GPS devices such as Strava have become very popular over recent years. Their intended use is to track physical activity and monitor training. However, many people routinely use such apps to record their daily commutes by bicycle. At the aggregate level, these data provide a potentially rich source of information about the movement and behaviour of cyclists. Before such data can be relied upon, however, it is necessary to examine their representativeness and understand their potential biases. In this study, the flows obtained from Strava Metro (SM are compared with those obtained during the 2013 London Cycle Census (LCC. A set of linear regression models are constructed to predict LCC flows using SM flows along with a number of dummy variables including road type, hour of day, day of week and presence/absence of cycle lane. Cross-validation is used to test the fitted models on unseen LCC sites. SM flows are found to be a statistically significant (p<0.0001 predictor of total flows as measured by the LCC and the models yield R squared statistics of ~0.7 before considering spatio-temporal variation. The initial

  8. Estimating nutrient releases from agriculture in China: An extended substance flow analysis framework and a modeling tool

    International Nuclear Information System (INIS)

    Chen, M.; Chen, J.; Sun, F.

    2010-01-01

    Agriculture related pollution has attracted the attention of policy makers as well as scientists in China as its contribution to water impairment has increased, and quantitative information at the national and regional levels is being sought to support decision making. However, traditional approaches are either time-consuming, expensive (e.g. national surveys) or oversimplified and crude (e.g. coefficient methods). Therefore, this study proposed an extended substance flow analysis (SFA) framework to estimate nutrient releases from agricultural and rural activities in China by depicting the nutrient flows in Chinese agro-ecosystems. The six-step process proposed herein includes: (a) system definition; (b) model development; (c) database development; (d) model validation; (e) results interpretation; and (f) uncertainty analysis. The developed Eubolism (Elementary Unit based nutrient Balance mOdeLIng in agro-ecoSysteM) model combined a nutrient balance module with an emission inventory module to quantify the nutrient flows in the agro-ecosystem. The model was validated and then applied to estimate the total agricultural nutrient loads, identify the contribution of different agricultural and rural activities and different land use types to the total loads, and analyze the spatial pattern of agricultural nutrient emissions in China. These results could provide an entire picture of agricultural pollution at the national level and be used to support policy making. Furthermore, uncertainties associated with the structure of the elementary units, spatial resolution, and inputs/parameters were also analyzed to evaluate the robustness of the model results.

  9. Variable disparity estimation based intermediate view reconstruction in dynamic flow allocation over EPON-based access networks

    Science.gov (United States)

    Bae, Kyung-Hoon; Lee, Jungjoon; Kim, Eun-Soo

    2008-06-01

    In this paper, a variable disparity estimation (VDE)-based intermediate view reconstruction (IVR) in dynamic flow allocation (DFA) over an Ethernet passive optical network (EPON)-based access network is proposed. In the proposed system, the stereoscopic images are estimated by a variable block-matching algorithm (VBMA), and they are transmitted to the receiver through DFA over EPON. This scheme improves a priority-based access network by converting it to a flow-based access network with a new access mechanism and scheduling algorithm, and then 16-view images are synthesized by the IVR using VDE. Some experimental results indicate that the proposed system improves the peak-signal-to-noise ratio (PSNR) to as high as 4.86 dB and reduces the processing time to 3.52 s. Additionally, the network service provider can provide upper limits of transmission delays by the flow. The modeling and simulation results, including mathematical analyses, from this scheme are also provided.

  10. Heat flux estimate of warm water flow in a low-temperature diffuse flow site, southern East Pacific Rise 17°25‧ S

    Science.gov (United States)

    Goto, Shusaku; Kinoshita, Masataka; Mitsuzawa, Kyohiko

    2003-09-01

    A low-temperature diffuse flow site associated with abundant vent fauna was found by submersible observations on the southern East Pacific Rise at 17°25‧ S in 1997. This site was characterized by thin sediment covered pillow and sheet lavas with collapsed pits up to ˜15 m in diameter. There were three warm water vents (temperature: 6.5 to 10.5 °C) within the site above which the vented fluids rise as plumes. To estimate heat flux of the warm water vents, a temperature logger array was deployed and the vertical temperature distribution in the water column up to 38 m above the seafloor was monitored. A stationary deep seafloor observatory system was also deployed to monitor hydrothermal activity in this site. The temperature logger array measured temperature anomalies, while the plumes from the vents passed through the array. Because the temperature anomalies were measured in only specific current directions, we identified one of the vents as the source. Heat flux from the vent was estimated by applying a plume model in crossflow in a density-stratified environment. The average heat flux from September 13 to October 18, 1997 was 39 MW. This heat flux is as same order as those of high-temperature black smokers, indicating that a large volume flux was discharged from the vent (1.9 m3/s). Previous observations found many similar warm water flow vents along the spreading axis between 17°20‧ S 30‧ S. The total heat flux was estimated to be at least a few hundred mega-watts. This venting style would contribute to form effluent hydrothermal plumes extended above the spreading axis.

  11. Interpretation of Flow Logs from Nevada Test Site Boreholes to Estimate Hydraulic conductivity Using Numerical Simulations Constrained by Single-Well Aquifer Tests

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, C. Amanda; Halford, Keith J.; Laczniak, Randell J.

    2010-02-12

    Hydraulic conductivities of volcanic and carbonate lithologic units at the Nevada Test Site were estimated from flow logs and aquifer-test data. Borehole flow and drawdown were integrated and interpreted using a radial, axisymmetric flow model, AnalyzeHOLE. This integrated approach is used because complex well completions and heterogeneous aquifers and confining units produce vertical flow in the annular space and aquifers adjacent to the wellbore. AnalyzeHOLE simulates vertical flow, in addition to horizontal flow, which accounts for converging flow toward screen ends and diverging flow toward transmissive intervals. Simulated aquifers and confining units uniformly are subdivided by depth into intervals in which the hydraulic conductivity is estimated with the Parameter ESTimation (PEST) software. Between 50 and 150 hydraulic-conductivity parameters were estimated by minimizing weighted differences between simulated and measured flow and drawdown. Transmissivity estimates from single-well or multiple-well aquifer tests were used to constrain estimates of hydraulic conductivity. The distribution of hydraulic conductivity within each lithology had a minimum variance because estimates were constrained with Tikhonov regularization. AnalyzeHOLE simulated hydraulic-conductivity estimates for lithologic units across screened and cased intervals are as much as 100 times less than those estimated using proportional flow-log analyses applied across screened intervals only. Smaller estimates of hydraulic conductivity for individual lithologic units are simulated because sections of the unit behind cased intervals of the wellbore are not assumed to be impermeable, and therefore, can contribute flow to the wellbore. Simulated hydraulic-conductivity estimates vary by more than three orders of magnitude across a lithologic unit, indicating a high degree of heterogeneity in volcanic and carbonate-rock units. The higher water transmitting potential of carbonate-rock units relative

  12. Interpretation of Flow Logs from Nevada Test Site Boreholes to Estimate Hydraulic Conductivity Using Numerical Simulations Constrained by Single-Well Aquifer Tests

    Science.gov (United States)

    Garcia, C. Amanda; Halford, Keith J.; Laczniak, Randell J.

    2010-01-01

    Hydraulic conductivities of volcanic and carbonate lithologic units at the Nevada Test Site were estimated from flow logs and aquifer-test data. Borehole flow and drawdown were integrated and interpreted using a radial, axisymmetric flow model, AnalyzeHOLE. This integrated approach is used because complex well completions and heterogeneous aquifers and confining units produce vertical flow in the annular space and aquifers adjacent to the wellbore. AnalyzeHOLE simulates vertical flow, in addition to horizontal flow, which accounts for converging flow toward screen ends and diverging flow toward transmissive intervals. Simulated aquifers and confining units uniformly are subdivided by depth into intervals in which the hydraulic conductivity is estimated with the Parameter ESTimation (PEST) software. Between 50 and 150 hydraulic-conductivity parameters were estimated by minimizing weighted differences between simulated and measured flow and drawdown. Transmissivity estimates from single-well or multiple-well aquifer tests were used to constrain estimates of hydraulic conductivity. The distribution of hydraulic conductivity within each lithology had a minimum variance because estimates were constrained with Tikhonov regularization. AnalyzeHOLE simulated hydraulic-conductivity estimates for lithologic units across screened and cased intervals are as much as 100 times less than those estimated using proportional flow-log analyses applied across screened intervals only. Smaller estimates of hydraulic conductivity for individual lithologic units are simulated because sections of the unit behind cased intervals of the wellbore are not assumed to be impermeable, and therefore, can contribute flow to the wellbore. Simulated hydraulic-conductivity estimates vary by more than three orders of magnitude across a lithologic unit, indicating a high degree of heterogeneity in volcanic and carbonate-rock units. The higher water transmitting potential of carbonate-rock units relative

  13. On the possibilities of watershed parameterization for extreme flow estimation in ungauged basins

    Directory of Open Access Journals (Sweden)

    S. Kohnová

    2015-06-01

    Full Text Available The estimation of design discharges and water levels of extreme floods is one of the most important parts of the design process for a large number of engineering projects and studies. Design flood estimates require a consideration of the hydrological, meteorological and physiographical situation, the legal requirements, and the available estimation techniques and methods. In the last decades changes in floods have been observed (Hall et al., 2014 which makes design flood estimation particularly challenging. Methods of design flood estimation can be applied either locally or regionally. A significant problem may arise in small catchments that are poorly gauged or when no recorded data exist. To obtain the design values in such cases, many countries have adopted procedures that fit the local conditions and requirements. One of these methods is the Soil Conservation Service – Curve number (SCS-CN method which is often used in design flood estimation for ungauged sites, including those in Slovakia. Since the method was derived on the basis of the specific characteristics of selected river basins in the United States, it may lead to significant uncertainties in other countries with different hydrological conditions. The aim of this study was to test the SCN-CN method and derive regional runoff curve numbers based on rainfall and discharge measurements for selected region in Slovakia. The results show that the classical CN method gives too high estimates of event runoff depths and is not valid in the study area. To avoid the overestimation of runoff caused by extreme rainfall events, the use of the empirically derived regional runoff curves was tested and finally proposed for practical application in engineering hydrology.

  14. Estimating the contribution of preferential flow to subsurface runoff from a hillslope using deuterium and chloride

    Science.gov (United States)

    Leaney, F. W.; Smettem, K. R. J.; Chittleborough, D. J.

    1993-06-01

    The concentrations of deuterium and chloride in rainfall, soil water and throughflow are reported for flow components through a mid-level gently sloping hillside podzolic soil with a well developed network of macropores. The deuterium and chloride signatures of the throughflow are shown to resemble that of rainfall rather than soil water for all rainfall events. Flow through macropores is considered to be the major mechanism for infiltration and throughflow. During the initial stages of rainfall, infiltrating water bypasses much of the soil matrix and a transient water table is established. Storage associated with this water table dampens much of the noise from the deuterium and chloride signature of the rainfall while maintaining the mean rainfall signature. The possible implications on the use of stable isotopes and conservative tracers such as chloride for streamflow partitioning are discussed.

  15. Nonlinear output feedback control of underwater vehicle propellers using feedback form estimated axial flow velocity

    DEFF Research Database (Denmark)

    Fossen, T. I.; Blanke, Mogens

    2000-01-01

    Accurate propeller shaft speed controllers can be designed by using nonlinear control theory and feedback from the axial water velocity in the propeller disc. In this paper, an output feedback controller is derived, reconstructing the axial flow velocity from vehicle speed measurements, using...... a three-state model of propeller shaft speed, forward (surge) speed of the vehicle, and the axial flow velocity. Lyapunov stability theory is used to prove that a nonlinear observer combined with an output feedback integral controller provide exponential stability. The output feedback controller...... compensates for variations in thrust due to time variations in advance speed. This is a major problem when applying conventional vehicle-propeller control systems, The proposed controller is simulated for an underwater vehicle equipped with a single propeller. The simulations demonstrate that the axial water...

  16. CAPILLARY BLOOD FLOW STATE ESTIMATION DURING PATIENTS TREATMENT WITH ORTODENTIC MECHANICAL APPLIANCES

    Directory of Open Access Journals (Sweden)

    D. A. Domenyuk

    2015-01-01

    Full Text Available Laser Doppler flowmetry was used to investigate the palatal muscosa capillary bloodflow in children aged 4.5-9 years with crowded teeth undergoing treatment with removable orthodontic appliances from cold-cured base polymers. The results obtained from the examination of the capillary blood flow based on the amplitude standard deviation, the variation coefficient, the amplitudes of vasomotor, breathing, and cardiorhythms, as well as the indices for active and passive mechanisms of blood flow modulation at the areas under study, showed that the hemodynamics indices in the palatal muscosa got disturbed a month after the treatment was started while the disturbances went even worse at later stages

  17. Photometric estimation of plutonium in product solutions and acid waste solutions using flow injection analysis technique

    International Nuclear Information System (INIS)

    Dhas, A.J.A.; Dharmapurikar, G.R.; Kumaraguru, K.; Vijayan, K.; Kapoor, S.C.; Ramanujam, A.

    1995-01-01

    Flow injection analysis technique is employed for the measurement of plutonium concentrations in product nitrate solutions by measuring the absorbance of Pu(III) at 565 nm and of Pu(IV) at 470 nm, using a Metrohm 662 photometer, with a pyrex glass tube of 2 nm (ID) inserted in the light path of the detector serving as a flow cell. The photometer detector never comes in contact with radioactive solution. In the case of acid waste solutions Pu is first purified by extraction chromatography with 2-ethyl hexyl hydrogen 2 ethyl hexyl phosphonate (KSM 17)- chromosorb and the Pu in the eluate in complexed with Arsenazo III followed by the measured of absorbance at 665 nm. Absorbance of reference solutions in the desired concentration ranges are measured to calibrate the system. The results obtained agree with the reference values within ±2.0%. (author). 3 refs., 1 tab

  18. Monodimensional estimation of maximum Reynolds shear stress in the downstream flow field of bileaflet valves.

    Science.gov (United States)

    Grigioni, Mauro; Daniele, Carla; D'Avenio, Giuseppe; Barbaro, Vincenzo

    2002-05-01

    Turbulent flow generated by prosthetic devices at the bloodstream level may cause mechanical stress on blood particles. Measurement of the Reynolds stress tensor and/or some of its components is a mandatory step to evaluate the mechanical load on blood components exerted by fluid stresses, as well as possible consequent blood damage (hemolysis or platelet activation). Because of the three-dimensional nature of turbulence, in general, a three-component anemometer should be used to measure all components of the Reynolds stress tensor, but this is difficult, especially in vivo. The present study aimed to derive the maximum Reynolds shear stress (RSS) in three commercially available prosthetic heart valves (PHVs) of wide diffusion, starting with monodimensional data provided in vivo by echo Doppler. Accurate measurement of PHV flow field was made using laser Doppler anemometry; this provided the principal turbulence quantities (mean velocity, root-mean-square value of velocity fluctuations, average value of cross-product of velocity fluctuations in orthogonal directions) needed to quantify the maximum turbulence-related shear stress. The recorded data enabled determination of the relationship, the Reynolds stresses ratio (RSR) between maximum RSS and Reynolds normal stress in the main flow direction. The RSR was found to be dependent upon the local structure of the flow field. The reported RSR profiles, which permit a simple calculation of maximum RSS, may prove valuable during the post-implantation phase, when an assessment of valve function is made echocardiographically. Hence, the risk of damage to blood constituents associated with bileaflet valve implantation may be accurately quantified in vivo.

  19. Estimating flow characteristics of different weir types and optimum dimensions of downstream receiving pool

    OpenAIRE

    Emiroglu, M. Emin

    2010-01-01

    This paper presents the results of a laboratory study on the flow characteristics of sharp-crested weirs, broad-crested weirs, and labyrinth weirs. The variation of the maximum bubble penetration depth for different weir types is investigated depending on overfall jet expansion, discharge, and drop height. Moreover, most efficient depth, length and width of the downstream receiving pool in an open channel system are studied by considering the penetration depth, overfall jet expansion, jet tra...

  20. Design of a Bidirectional Energy Storage System for a Vanadium Redox Flow Battery in a Microgrid with SOC Estimation

    Directory of Open Access Journals (Sweden)

    Qingwu Gong

    2017-03-01

    Full Text Available This paper used a Vanadium Redox flow Battery (VRB as the storage battery and designed a two-stage topology of a VRB energy storage system in which a phase-shifted full bridge dc-dc converter and three-phase inverter were used, considering the low terminal voltage of the VRB. Following this, a model of the VRB was simplified, according to the operational characteristics of the VRB in this designed topology of a VRB energy storage system (ESS. By using the simplified equivalent model of the VRB, the control parameters of the ESS were designed. For effectively estimating the state of charge (SOC of the VRB, a traditional method for providing the SOC estimation was simplified, and a simple and effective SOC estimation method was proposed in this paper. Finally, to illustrate the proper design of the VRB ESS and the proposed SOC estimation method, a corresponding simulation was designed by Simulink. The test results have demonstrated that this proposed SOC estimation method is feasible and effective for indicating the SOC of a VRB and the proper design of this VRB ESS is very reasonable for VRB applications.

  1. A prototype of radar-drone system for measuring the surface flow velocity at river sites and discharge estimation

    Science.gov (United States)

    Moramarco, Tommaso; Alimenti, Federico; Zucco, Graziano; Barbetta, Silvia; Tarpanelli, Angelica; Brocca, Luca; Mezzanotte, Paolo; Rosselli, Luca; Orecchini, Giulia; Virili, Marco; Valigi, Paolo; Ciarfuglia, Thomas; Pagnottelli, Stefano

    2015-04-01

    Discharge estimation at a river site depends on local hydraulic conditions identified by recording water levels. In fact, stage monitoring is straightforward and relatively inexpensive compared with the cost necessary to carry out flow velocity measurements which are, however, limited to low flows and constrained by the accessibility of the site. In this context the mean flow velocity is hard to estimate for high flow, affecting de-facto the reliability of discharge assessment for extreme events. On the other hand, the surface flow velocity can be easily monitored by using radar sensors allowing to achieve a good estimate of discharge by exploiting the entropy theory applied to rivers hydraulic (Chiu,1987). Recently, a growing interest towards the use of Unmanned Aerial Vehicle (UVA), henceforth drone, for topographic applications is observed and considering their capability drones may be of a considerable interest for the hydrological monitoring and in particular for streamflow measurements. With this aim, for the first time, a miniaturized Doppler radar sensor, operating at 24 GHz, will be mounted on a drone to measure the surface flow velocity in rivers. The sensor is constituted by a single-board circuit (i.e. is a fully planar circuits - no waveguides) with the antenna on one side and the front-end electronic on the other side (Alimenti et al., 2007). The antenna has a half-power beam width of less than 10 degrees in the elevation plane and a gain of 13 dBi. The radar is equipped with a monolithic oscillator and transmits a power of about 4 mW at 24 GHz. The sensor is mounted with an inclination of 45 degrees with respect to the drone flying plane and such an angle is considered in recovering the surface speed of the water. The drone is a quadricopter that has more than 30 min, flying time before recharging the battery. Furthermore its flying plan can be scheduled with a suitable software and is executed thanks to the on-board sensors (GPS, accelerometers

  2. Optimization of Financial Flow Management Based on Estimates of Regional Multiplicative Effects

    Directory of Open Access Journals (Sweden)

    Denis Aleksandrovich Tatarkin

    2015-12-01

    Full Text Available The article deals with questions of increasing the management efficiency of the regional financial resources. As the main hypothesis, the idea of the optimization of the management of the regional financial flows based on the multiplicative economic effect is proved. This measure will allow to evaluate more efficiently the impact of the regional socio-economic policy. The article presents a multifactor model of the management of the regional financial flows on the regional level — the matrix of financial flows, based on the principles of the general economic equilibrium theory, the balance method of «input-output» and the methodology of national accounts. The paper introduces a methodology for the integration of the regional consolidated budget balance in a matrix of financial flows. Matrix multipliers of the consolidated budget balance are calculated for some regions of the Russian Federation allowing to model the economic multiplicative effects resulting from impact of different types of exogenous factors on the economic development of the regions, such as to predict the impact of fiscal redistribution on the GRP and income, to assess the impact of foreign investment on economic growth, to explore the effectiveness of the federal tax policy at the regional level. The article shows that the multiplier effect depends on several factors, including the foreign trade relations of the region, its dependence on imports, the share of value added in gross output, as well as the household savings. Various levels of government can use the author’s approach during development of strategies for socio-economic development, in assessing the extent and direction of the influence of exogenous factors on the economy of the territory, as well as in analyzing the investment initiatives from the private sector applying for state financial support for projects. In the conclusion, the ways of improving the management of financial flows on the basis of

  3. Estimated probabilities, volumes, and inundation areas depths of potential postwildfire debris flows from Carbonate, Slate, Raspberry, and Milton Creeks, near Marble, Gunnison County, Colorado

    Science.gov (United States)

    Stevens, Michael R.; Flynn, Jennifer L.; Stephens, Verlin C.; Verdin, Kristine L.

    2011-01-01

    During 2009, the U.S. Geological Survey, in cooperation with Gunnison County, initiated a study to estimate the potential for postwildfire debris flows to occur in the drainage basins occupied by Carbonate, Slate, Raspberry, and Milton Creeks near Marble, Colorado. Currently (2010), these drainage basins are unburned but could be burned by a future wildfire. Empirical models derived from statistical evaluation of data collected from recently burned basins throughout the intermountain western United States were used to estimate the probability of postwildfire debris-flow occurrence and debris-flow volumes for drainage basins occupied by Carbonate, Slate, Raspberry, and Milton Creeks near Marble. Data for the postwildfire debris-flow models included drainage basin area; area burned and burn severity; percentage of burned area; soil properties; rainfall total and intensity for the 5- and 25-year-recurrence, 1-hour-duration-rainfall; and topographic and soil property characteristics of the drainage basins occupied by the four creeks. A quasi-two-dimensional floodplain computer model (FLO-2D) was used to estimate the spatial distribution and the maximum instantaneous depth of the postwildfire debris-flow material during debris flow on the existing debris-flow fans that issue from the outlets of the four major drainage basins. The postwildfire debris-flow probabilities at the outlet of each drainage basin range from 1 to 19 percent for the 5-year-recurrence, 1-hour-duration rainfall, and from 3 to 35 percent for 25-year-recurrence, 1-hour-duration rainfall. The largest probabilities for postwildfire debris flow are estimated for Raspberry Creek (19 and 35 percent), whereas estimated debris-flow probabilities for the three other creeks range from 1 to 6 percent. The estimated postwildfire debris-flow volumes at the outlet of each creek range from 7,500 to 101,000 cubic meters for the 5-year-recurrence, 1-hour-duration rainfall, and from 9,400 to 126,000 cubic meters for

  4. Blood donation and blood donor mortality after adjustment for a healthy donor effect

    DEFF Research Database (Denmark)

    Ullum, Henrik; Rostgaard, Klaus; Kamper-Jørgensen, Mads

    2015-01-01

    BACKGROUND: Studies have repeatedly demonstrated that blood donors experience lower mortality than the general population. While this may suggest a beneficial effect of blood donation, it may also reflect the selection of healthy persons into the donor population. To overcome this bias, we...... investigated the relation between blood donation frequency and mortality within a large cohort of blood donors. In addition, our analyses also took into consideration the effects of presumed health differences linked to donation behavior. STUDY DESIGN AND METHODS: Using the Scandinavian Donation...... and mortality. The magnitude of the association was reduced after adjustment for an estimate of self-selection in the donor population. Our observations indicate that repeated blood donation is not associated with premature death, but cannot be interpreted as conclusive evidence of a beneficial health effect....

  5. Culvert Analysis Program Graphical User Interface 1.0--A preprocessing and postprocessing tool for estimating flow through culvert

    Science.gov (United States)

    Bradley, D. Nathan

    2013-01-01

    The peak discharge of a flood can be estimated from the elevation of high-water marks near the inlet and outlet of a culvert after the flood has occurred. This type of discharge estimate is called an “indirect measurement” because it relies on evidence left behind by the flood, such as high-water marks on trees or buildings. When combined with the cross-sectional geometry of the channel upstream from the culvert and the culvert size, shape, roughness, and orientation, the high-water marks define a water-surface profile that can be used to estimate the peak discharge by using the methods described by Bodhaine (1968). This type of measurement is in contrast to a “direct” measurement of discharge made during the flood where cross-sectional area is measured and a current meter or acoustic equipment is used to measure the water velocity. When a direct discharge measurement cannot be made at a streamgage during high flows because of logistics or safety reasons, an indirect measurement of a peak discharge is useful for defining the high-flow section of the stage-discharge relation (rating curve) at the streamgage, resulting in more accurate computation of high flows. The Culvert Analysis Program (CAP) (Fulford, 1998) is a command-line program written in Fortran for computing peak discharges and culvert rating surfaces or curves. CAP reads input data from a formatted text file and prints results to another formatted text file. Preparing and correctly formatting the input file may be time-consuming and prone to errors. This document describes the CAP graphical user interface (GUI)—a modern, cross-platform, menu-driven application that prepares the CAP input file, executes the program, and helps the user interpret the output

  6. Computed statistics at streamgages, and methods for estimating low-flow frequency statistics and development of regional regression equations for estimating low-flow frequency statistics at ungaged locations in Missouri

    Science.gov (United States)

    Southard, Rodney E.

    2013-01-01

    The weather and precipitation patterns in Missouri vary considerably from year to year. In 2008, the statewide average rainfall was 57.34 inches and in 2012, the statewide average rainfall was 30.64 inches. This variability in precipitation and resulting streamflow in Missouri underlies the necessity for water managers and users to have reliable streamflow statistics and a means to compute select statistics at ungaged locations for a better understanding of water availability. Knowledge of surface-water availability is dependent on the streamflow data that have been collected and analyzed by the U.S. Geological Survey for more than 100 years at approximately 350 streamgages throughout Missouri. The U.S. Geological Survey, in cooperation with the Missouri Department of Natural Resources, computed streamflow statistics at streamgages through the 2010 water year, defined periods of drought and defined methods to estimate streamflow statistics at ungaged locations, and developed regional regression equations to compute selected streamflow statistics at ungaged locations. Streamflow statistics and flow durations were computed for 532 streamgages in Missouri and in neighboring States of Missouri. For streamgages with more than 10 years of record, Kendall’s tau was computed to evaluate for trends in streamflow data. If trends were detected, the variable length method was used to define the period of no trend. Water years were removed from the dataset from the beginning of the record for a streamgage until no trend was detected. Low-flow frequency statistics were then computed for the entire period of record and for the period of no trend if 10 or more years of record were available for each analysis. Three methods are presented for computing selected streamflow statistics at ungaged locations. The first method uses power curve equations developed for 28 selected streams in Missouri and neighboring States that have multiple streamgages on the same streams. Statistical

  7. Frequency and risk factors for donor reactions in an anonymous blood donor survey.

    Science.gov (United States)

    Goldman, Mindy; Osmond, Lori; Yi, Qi-Long; Cameron-Choi, Keltie; O'Brien, Sheila F

    2013-09-01

    Adverse donor reactions can result in injury and decrease the likelihood of donor return. Reaction reports captured in the blood center's database provide an incomplete picture of reaction rates and risk factors. We performed an anonymous survey, mailed to 40,000 donors in 2008, including questions about symptoms, height, weight, sex, and donation status. Reaction rates were compared to those recorded in our database. Possible risk factors were assessed for various reactions. The response rate was 45.5%. A total of 32% of first-time and 14% of repeat donors reported having any adverse symptom, most frequently bruising (84.9 per 1000 donors) or feeling faint or weak (66.2 per 1000). Faint reactions were two to eight times higher than reported in our database, although direct comparison was difficult. Younger age, female sex, and first-time donation status were risk factors for systemic and arm symptoms. In females, low estimated blood volume (EBV) was a risk factor for systemic symptoms. Only 51% of donors who consulted an outside physician also called Canadian Blood Services. A total of 10% of first-time donors with reactions found adverse effects information inadequate. This study allowed us to collect more information about adverse reactions, including minor symptoms and delayed reactions. Based on our findings of the risk factors and frequency of adverse reactions, we are implementing more stringent EBV criteria for younger donors and providing more detailed information to donors about possible adverse effects and their management. © 2012 American Association of Blood Banks.

  8. Influence of temporally variable groundwater flow conditions on point measurements and contaminant mass flux estimations

    DEFF Research Database (Denmark)

    Rein, Arno; Bauer, S; Dietrich, P

    2009-01-01

    Monitoring of contaminant concentrations, e.g., for the estimation of mass discharge or contaminant degradation rates. often is based on point measurements at observation wells. In addition to the problem, that point measurements may not be spatially representative. a further complication may ari...

  9. Joint disparity and motion estimation using optical flow for multiview Distributed Video Coding

    DEFF Research Database (Denmark)

    Salmistraro, Matteo; Raket, Lars Lau; Brites, Catarina

    2014-01-01

    Distributed Video Coding (DVC) is a video coding paradigm where the source statistics are exploited at the decoder based on the availability of Side Information (SI). In a monoview video codec, the SI is generated by exploiting the temporal redundancy of the video, through motion estimation and c...

  10. Estimation of traffic recovery time for different flow regimes on freeways.

    Science.gov (United States)

    2008-06-01

    This study attempts to estimate post-incident traffic recovery time along a freeway using Monte Carlo simulation techniques. It has been found that there is a linear relationship between post-incident traffic recovery time, and incident time and traf...

  11. Laparoscopic nephrectomy in live donor

    Directory of Open Access Journals (Sweden)

    Mitre Anuar I.

    2004-01-01

    Full Text Available OBJECTIVE: To present the initial experience of videolaparoscopic nephrectomy in live renal donor. MATERIALS AND METHODS: In the period from April 2000 to August 2003, 50 left nephrectomies in live donor were performed by videolaparoscopy for transplantation. Twenty-eight patients were male (56% and 22 female (44%. Mean age was 37.2 years, and the mean body mass index (BMI was 27.1 kg/m². RESULTS: Mean surgical time was 179.5 minutes, and warm ischemia time of the graft was 3.79 minutes. The mean estimated bleeding was 141 mL. There was no need of blood transfusion or conversion to open surgery. In 42 cases (84%, the vascular portion of the graft was considered good by the recipient's surgical team and in all cases, the ureter was considered of proper size, though in one of them (2% its vascularization was considered improper. The transplanted kidneys produced urine still in the surgical room in 46 of the 50 transplantations considered. In only 2 cases opioid was required for analgesia. In average, 3.1 doses of dipyrone were used for each patient during hospital stay, and hospital discharge occurred, in average, after 3.2 days post-operatively. Two patients required re-operations and one of them evolved to death. CONCLUSIONS: The laparoscopic nephrectomy in live donor for renal transplantation is an alternative to conventional open surgery. In relation to the graft, no alteration, either anatomic or functional, was detected. Though there is already a large documentation in the international literature regarding this procedure, in our setting a prospective randomized study with the usual surgical study is still necessary in order to prove the advantages and disadvantages of the method.

  12. Laparoscopic nephrectomy in live donor

    Directory of Open Access Journals (Sweden)

    Anuar I. Mitre

    2004-02-01

    Full Text Available OBJECTIVE: To present the initial experience of videolaparoscopic nephrectomy in live renal donor. MATERIALS AND METHODS: In the period from April 2000 to August 2003, 50 left nephrectomies in live donor were performed by videolaparoscopy for transplantation. Twenty-eight patients were male (56% and 22 female (44%. Mean age was 37.2 years, and the mean body mass index (BMI was 27.1 kg/m². RESULTS: Mean surgical time was 179.5 minutes, and warm ischemia time of the graft was 3.79 minutes. The mean estimated bleeding was 141 mL. There was no need of blood transfusion or conversion to open surgery. In 42 cases (84%, the vascular portion of the graft was considered good by the recipient's surgical team and in all cases, the ureter was considered of proper size, though in one of them (2% its vascularization was considered improper. The transplanted kidneys produced urine still in the surgical room in 46 of the 50 transplantations considered. In only 2 cases opioid was required for analgesia. In average, 3.1 doses of dipyrone were used for each patient during hospital stay, and hospital discharge occurred, in average, after 3.2 days post-operatively. Two patients required re-operations and one of them evolved to death. CONCLUSIONS: The laparoscopic nephrectomy in live donor for renal transplantation is an alternative to conventional open surgery. In relation to the graft, no alteration, either anatomic or functional, was detected. Though there is already a large documentation in the international literature regarding this procedure, in our setting a prospective randomized study with the usual surgical study is still necessary in order to prove the advantages and disadvantages of the method.

  13. Exact solutions to traffic density estimation problems involving the Lighthill-Whitham-Richards traffic flow model using mixed integer programming

    KAUST Repository

    Canepa, Edward S.; Claudel, Christian G.

    2012-01-01

    This article presents a new mixed integer programming formulation of the traffic density estimation problem in highways modeled by the Lighthill Whitham Richards equation. We first present an equivalent formulation of the problem using an Hamilton-Jacobi equation. Then, using a semi-analytic formula, we show that the model constraints resulting from the Hamilton-Jacobi equation result in linear constraints, albeit with unknown integers. We then pose the problem of estimating the density at the initial time given incomplete and inaccurate traffic data as a Mixed Integer Program. We then present a numerical implementation of the method using experimental flow and probe data obtained during Mobile Century experiment. © 2012 IEEE.

  14. Exact solutions to traffic density estimation problems involving the Lighthill-Whitham-Richards traffic flow model using mixed integer programming

    KAUST Repository

    Canepa, Edward S.

    2012-09-01

    This article presents a new mixed integer programming formulation of the traffic density estimation problem in highways modeled by the Lighthill Whitham Richards equation. We first present an equivalent formulation of the problem using an Hamilton-Jacobi equation. Then, using a semi-analytic formula, we show that the model constraints resulting from the Hamilton-Jacobi equation result in linear constraints, albeit with unknown integers. We then pose the problem of estimating the density at the initial time given incomplete and inaccurate traffic data as a Mixed Integer Program. We then present a numerical implementation of the method using experimental flow and probe data obtained during Mobile Century experiment. © 2012 IEEE.

  15. Poor agreement between transcranial Doppler and near-infrared spectroscopy-based estimates of cerebral blood flow changes in sepsis

    DEFF Research Database (Denmark)

    Toksvang, Linea N; Plovsing, Ronni R; Petersen, Marie W

    2014-01-01

    BACKGROUND: Continuous monitoring of cerebral blood flow (CBF) may be valuable in critically ill patients with sepsis. In this study, we compared spatially resolved near-infrared spectroscopy (NIRS) to transcranial Doppler ultrasound (TCD)-derived estimates of noradrenaline-associated changes...... in CBF in such patients. METHODS: Mean arterial blood pressure (MAP) was elevated by increasing the noradrenaline infusion rate in eight mechanically ventilated, critically ill patients diagnosed with severe sepsis or septic shock. The associated changes in CBF were assessed by simultaneous ipsilateral......-derived estimates with a relative bias of 14% and limits of agreement of -18% to 45% change in CBF. CONCLUSION: Our findings stress that TCD and NIRS cannot be used interchangeably for monitoring changes in cerebral haemodynamics in critically ill patients with sepsis receiving vasopressor treatment...

  16. Effect of the Length of Traffic Flow Records on the Estimate of a Bridge Service Life

    Directory of Open Access Journals (Sweden)

    Krejsa Jan

    2016-12-01

    Full Text Available The service life of bridges is significantly affected by fatigue of used material induced by heavy vehicles. Therefore, precise determination of the vehicle weight is of crucial importance for the calculation of fatigue damage and the prediction of the bridge serviceability. This paper investigates accuracy of the determination of fatigue depending on the length of traffic flow recording. The presented data were obtained from the measurements carried out on a bridge of the Prague Highway Ring. The analysis reveals that the optimal length of traffic recording is about 30 days.

  17. Novel nuclei isolation buffer for flow cytometric genome size estimation of Zingiberaceae: a comparison with common isolation buffers.

    Science.gov (United States)

    Sadhu, Abhishek; Bhadra, Sreetama; Bandyopadhyay, Maumita

    2016-11-01

    Cytological parameters such as chromosome numbers and genome sizes of plants are used routinely for studying evolutionary aspects of polyploid plants. Members of Zingiberaceae show a wide range of inter- and intrageneric variation in their reproductive habits and ploidy levels. Conventional cytological study in this group of plants is severely hampered by the presence of diverse secondary metabolites, which also affect their genome size estimation using flow cytometry. None of the several nuclei isolation buffers used in flow cytometry could be used very successfully for members of Zingiberaceae to isolate good quality nuclei from both shoot and root tissues. The competency of eight nuclei isolation buffers was compared with a newly formulated buffer, MB01, in six different genera of Zingiberaceae based on the fluorescence intensity of propidium iodide-stained nuclei using flow cytometric parameters, namely coefficient of variation of the G 0 /G 1 peak, debris factor and nuclei yield factor. Isolated nuclei were studied using fluorescence microscopy and bio-scanning electron microscopy to analyse stain-nuclei interaction and nuclei topology, respectively. Genome contents of 21 species belonging to these six genera were determined using MB01. Flow cytometric parameters showed significant differences among the analysed buffers. MB01 exhibited the best combination of analysed parameters; photomicrographs obtained from fluorescence and electron microscopy supported the superiority of MB01 buffer over other buffers. Among the 21 species studied, nuclear DNA contents of 14 species are reported for the first time. Results of the present study substantiate the enhanced efficacy of MB01, compared to other buffers tested, in the generation of acceptable cytograms from all species of Zingiberaceae studied. Our study facilitates new ways of sample preparation for further flow cytometric analysis of genome size of other members belonging to this highly complex polyploid family

  18. BLOOD DONORS CAMPAIGN

    CERN Document Server

    Medical Service

    2002-01-01

    Tuesday 19 March 2002 in restaurant nr 2, from 9.00 to 16.30 hrs A blood donors campaign, organized by the Centre de Transfusion sanguine of Geneva If you already have a card giving your blood group, please bring this with you.

  19. BLOOD DONORS CAMPAIGN

    CERN Multimedia

    2001-01-01

    A blood donors campaign, organized by the Centre de Transfusion Sanguine of Geneva will be held at CERN on Tuesday 13 March 2001 in restaurant nr 2, from 9.00 to 16.30 hrs If you already have a card giving your blood group, please bring this with you.

  20. BLOOD DONORS CAMPAIGN

    CERN Document Server

    2002-01-01

    Wednesday 13 November 2002 in restaurant nr 2, from 8.30 to 16.30 hrs will be held a blood donors campaign, organized by the Etablissement de Transfusion de Haute-Savoie If you already have a card giving your blood group, please bring this with you.

  1. BLOOD DONORS CAMPAIGN

    CERN Document Server

    2000-01-01

    A blood donors campaign, organized by the Établissement de Transfusion de Rhône-Alpes will be held at CERN on Tuesday 14 November 2000 in restaurant nr 2, from 8.30 to 16.30 hrs If you already have a card giving your blood group, please bring this with you.

  2. BLOOD DONORS CAMPAIGN

    CERN Document Server

    2001-01-01

    A blood donors campaign, organized by the Centre de Transfusion d'Annemasse will be held at CERN on Tuesday 14 November 2001 in restaurant nr 2, from 9.00 to 16.30 hrs If you already have a card giving your blood group, please bring this with you.

  3. Bed Evolution under Rapidly Varying Flows by a New Method for Wave Speed Estimation

    Directory of Open Access Journals (Sweden)

    Khawar Rehman

    2016-05-01

    Full Text Available This paper proposes a sediment-transport model based on coupled Saint-Venant and Exner equations. A finite volume method of Godunov type with predictor-corrector steps is used to solve a set of coupled equations. An efficient combination of approximate Riemann solvers is proposed to compute fluxes associated with sediment-laden flow. In addition, a new method is proposed for computing the water depth and velocity values along the shear wave. This method ensures smooth solutions, even for flows with high discontinuities, and on domains with highly distorted grids. The numerical model is tested for channel aggradation on a sloping bottom, dam-break cases at flume-scale and reach-scale with flat bottom configurations and varying downstream water depths. The proposed model is tested for predicting the position of hydraulic jump, wave front propagation, and for predicting magnitude of bed erosion. The comparison between results based on the proposed scheme and analytical, experimental, and published numerical results shows good agreement. Sensitivity analysis shows that the model is computationally efficient and virtually independent of mesh refinement.

  4. Donor transplant programme

    International Nuclear Information System (INIS)

    Abu Bakar Sulaiman

    1999-01-01

    The transplantation of organs and tissues from one human to another human has become an essential and well established form of therapy for many types of organ and tissue failure. In Malaysia, kidney, cornea and bone marrow transplantation are well established. Recently, liver, bone and heart transplanation have been performed. Unfortunately, because of the lack of cadaveric organ donation, only a limited number of solid organ transplantation have been performed. The cadaveric organ donor rate in Malaysia is low at less than one per million population. The first tissue transplanted in Malaysia was the cornea which was performed in the early 1970s. At that time and even now the majority of corneas came from Sri Lanka. The first kidney transplant was performed in 1975 from a live related donor. The majority of the 629 kidney transplants done at Hospital Kuala Lumpur to date have been from live related donors. Only 35 were from cadaver donors. Similarly, the liver transplantation programme which started in 1995 are from live related donors. A more concerted effort has been made recently to increase the awareness of the public and the health professionals on organ and tissue donation. This national effort to promote organ and tissue donation seems to have gathered momentum in 1997 with the first heart transplant successfully performed at the National Heart Institute. The rate of cadaveric donors has also increased from a previous average of I to 2 per year to 6 per year in the last one year. These developments are most encouraging and may signal the coming of age of our transplantati on programme. The Ministry of Health in conjunction with various institutions, organizations and professional groups, have taken a number of proactive measures to facilitate the development of the cadaveric organ donation programme. Efforts to increase public awareness and to overcome the negative cultural attitude towards organ donation have been intensified. Equally important are efforts

  5. An adaptive model for vanadium redox flow battery and its application for online peak power estimation

    Science.gov (United States)

    Wei, Zhongbao; Meng, Shujuan; Tseng, King Jet; Lim, Tuti Mariana; Soong, Boon Hee; Skyllas-Kazacos, Maria

    2017-03-01

    An accurate battery model is the prerequisite for reliable state estimate of vanadium redox battery (VRB). As the battery model parameters are time varying with operating condition variation and battery aging, the common methods where model parameters are empirical or prescribed offline lacks accuracy and robustness. To address this issue, this paper proposes to use an online adaptive battery model to reproduce the VRB dynamics accurately. The model parameters are online identified with both the recursive least squares (RLS) and the extended Kalman filter (EKF). Performance comparison shows that the RLS is superior with respect to the modeling accuracy, convergence property, and computational complexity. Based on the online identified battery model, an adaptive peak power estimator which incorporates the constraints of voltage limit, SOC limit and design limit of current is proposed to fully exploit the potential of the VRB. Experiments are conducted on a lab-scale VRB system and the proposed peak power estimator is verified with a specifically designed "two-step verification" method. It is shown that different constraints dominate the allowable peak power at different stages of cycling. The influence of prediction time horizon selection on the peak power is also analyzed.

  6. COPATH - a spreadsheet model for the estimation of carbon flows associated with the use of forest resources

    International Nuclear Information System (INIS)

    Makundi, W.; Sathaye, J.; Ketoff, A.

    1995-01-01

    The forest sector plays a key role in the global climate change process. A significant amount of net greenhouse gas emissions emanate from land use changes, and the sector offers a unique opportunity to sequester carbon in vegetation, detritus, soils and forest products. However, the estimates of carbon flows associated with the use of forest resources have been quite imprecise. This paper describes a methodological framework-COPATH-which is a spreadsheet model for estimating carbon emissions and sequestration from deforestation and harvesting of forests. The model has two parts, the first estimates carbon stocks, emissions and uptake in the base year, while the second part forecasts future emissions and the uptake under various scenarios. The forecast module is structured after the main modes of forest conversion, i.e. agriculture, pasture, forest harvesting and other land uses. The model can be used by countries which may not possess an abundance of pertinent data, and allows for the use of forest inventory data to estimate carbon stocks. The choice of the most likely scenario provides the country with a carbon flux profile necessary to formulate GHG mitigation strategies. (Author)

  7. Reproducibility of estimation of blood flow in the human masseter muscle from measurements of 133Xe clearance

    International Nuclear Information System (INIS)

    Monteiro, A.A.; Kopp, S.

    1989-01-01

    The reproducibility of estimations of the masseter intramuscular blood flow (IMBF) was assessed bilaterally within and between clinical sessions. The 133 Xe clearance in nine normal individuals was measured before, during, and immediately after endurance of isometric contraction at an attempted level of 50% of maximum voluntary clenching contraction. An overall low reproducibility of the estimations was found. This result was probably caused by uncertainties about the excact site of intramuscular 133 Xe deposition, errors in assessment of the plots of clearance, and variabilities in the relative contraction levels sustained, especially in the overall muscle effort. In agreement with previous reports concerning other skeletal muscles, the 133 Xe clearance method provided inconsistent estimates of absolute values of IMBF also in this clinical setting. Although there was a high intra-individual variation in the relative level of isometric contraction sustained, the endurance test induced distinct changes in IMBF, among which the estimate of post-endurance hyperemia was the most consistent for each individual. Therefore, measurements of 133 Xe clearance seem to be useful to detect intra-induvidual changes in masseter IMBF resulting from isometric work. 21 refs

  8. Evaluating Investments in Natural Gas Vehicles and Infrastructure for Your Fleet: Vehicle Infrastructure Cash-Flow Estimation -- VICE 2.0; Clean Cities, Energy Efficiency & Renewable Energy (EERE)

    Energy Technology Data Exchange (ETDEWEB)

    Gonzales, John

    2015-04-02

    Presentation by Senior Engineer John Gonzales on Evaluating Investments in Natural Gas Vehicles and Infrastructure for Your Fleet using the Vehicle Infrastructure Cash-flow Estimation (VICE) 2.0 model.

  9. Use of instantaneous streamflow measurements to improve regression estimates of index flow for the summer month of lowest streamflow in Michigan

    Science.gov (United States)

    Holtschlag, David J.

    2011-01-01

    In Michigan, index flow Q50 is a streamflow characteristic defined as the minimum of median flows for July, August, and September. The state of Michigan uses index flow estimates to help regulate large (greater than 100,000 gallons per day) water withdrawals to prevent adverse effects on characteristic fish populations. At sites where long-term streamgages are located, index flows are computed directly from continuous streamflow records as GageQ50. In an earlier study, a multiple-regression equation was developed to estimate index flows IndxQ50 at ungaged sites. The index equation explains about 94 percent of the variability of index flows at 147 (index) streamgages by use of six explanatory variables describing soil type, aquifer transmissivity, land cover, and precipitation characteristics. This report extends the results of the previous study, by use of Monte Carlo simulations, to evaluate alternative flow estimators, DiscQ50, IntgQ50, SiteQ50, and AugmQ50. The Monte Carlo simulations treated each of the available index streamgages, in turn, as a miscellaneous site where streamflow conditions are described by one or more instantaneous measurements of flow. In the simulations, instantaneous flows were approximated by daily mean flows at the corresponding site. All estimators use information that can be obtained from instantaneous flow measurements and contemporaneous daily mean flow data from nearby long-term streamgages. The efficacy of these estimators was evaluated over a set of measurement intensities in which the number of simulated instantaneous flow measurements ranged from 1 to 100 at a site. The discrete measurement estimator DiscQ50 is based on a simple linear regression developed between information on daily mean flows at five or more streamgages near the miscellaneous site and their corresponding GageQ50 index flows. The regression relation then was used to compute a DiscQ50 estimate at the miscellaneous site by use of the simulated instantaneous flow

  10. Simultaneous estimates of regional myocardial blood flow and metabolism by the developing chick heart using [201]thallium and [14C] 2-deoxyglucose autoradiography

    International Nuclear Information System (INIS)

    Kostreva, D.R.; Wood, J.D.

    1990-01-01

    Little is known about regional myocardial blood flow and metabolism in the developing heart. Simultaneous estimates of regional myocardial blood flow and glucose metabolism have been made in the adult rat by Yonekura et al using [ 201 ] Thallium (THAL) and [ 14 C]2-deoxyglucose (DG) autoradiography. Since glucose is the primary cardiac metabolic substrate during development, glucose utilization is also an estimate of myocardial metabolism. Examination and comparison of the THAL and DG autoradiographs revealed that there is an uncoupling of blood flow and metabolism in the developing chick heart. Areas of the heart which had marked glucose utilization did not always have marked blood flow. Regions of the heart which had marked blood flow but very little glucose utilization were the interventricular septum and the apex. One explanation for this disparity is that although blood flow may be established in these regions, normal cardiac function requiring significant substrate utilization may not be fully developed

  11. Error-Rate Estimation Based on Multi-Signal Flow Graph Model and Accelerated Radiation Tests.

    Directory of Open Access Journals (Sweden)

    Wei He

    Full Text Available A method of evaluating the single-event effect soft-error vulnerability of space instruments before launched has been an active research topic in recent years. In this paper, a multi-signal flow graph model is introduced to analyze the fault diagnosis and meantime to failure (MTTF for space instruments. A model for the system functional error rate (SFER is proposed. In addition, an experimental method and accelerated radiation testing system for a signal processing platform based on the field programmable gate array (FPGA is presented. Based on experimental results of different ions (O, Si, Cl, Ti under the HI-13 Tandem Accelerator, the SFER of the signal processing platform is approximately 10-3(error/particle/cm2, while the MTTF is approximately 110.7 h.

  12. Estimation of the quantification uncertainty from flow injection and liquid chromatography transient signals in inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    Laborda, Francisco; Medrano, Jesus; Castillo, Juan R.

    2004-01-01

    The quality of the quantitative results obtained from transient signals in high-performance liquid chromatography-inductively coupled plasma mass spectrometry (HPLC-ICPMS) and flow injection-inductively coupled plasma mass spectrometry (FI-ICPMS) was investigated under multielement conditions. Quantification methods were based on multiple-point calibration by simple and weighted linear regression, and double-point calibration (measurement of the baseline and one standard). An uncertainty model, which includes the main sources of uncertainty from FI-ICPMS and HPLC-ICPMS (signal measurement, sample flow rate and injection volume), was developed to estimate peak area uncertainties and statistical weights used in weighted linear regression. The behaviour of the ICPMS instrument was characterized in order to be considered in the model, concluding that the instrument works as a concentration detector when it is used to monitorize transient signals from flow injection or chromatographic separations. Proper quantification by the three calibration methods was achieved when compared to reference materials, although the double-point calibration allowed to obtain results of the same quality as the multiple-point calibration, shortening the calibration time. Relative expanded uncertainties ranged from 10-20% for concentrations around the LOQ to 5% for concentrations higher than 100 times the LOQ

  13. Preliminary methodological proposal for estimating environmental flows in projects approved by the ministry of environment and sustainable development (MADS), Colombia

    International Nuclear Information System (INIS)

    Pinilla Agudelo, Gabriel A; Rodriguez Sandoval, Erasmo A; Camacho Botero, Luis A

    2014-01-01

    A methodological proposal for estimating environmental flows in large projects approved by Agencia Nacional de Licencias Ambientales (ANLA) in Colombian rivers was developed. The project is the result of an agreement between the MADS and the Universidad Nacional de Colombia, Bogota (UNC). The proposed method begins with an evaluation of hydrological criteria, continues with a hydraulic and water quality validation, and follows with the determination of habitat integrity. This is an iterative process that compares conditions before and after the project construction and allows to obtain the magnitude of a monthly flow that, besides preserving the ecological functions of the river, guarantees the water uses downstream. Regarding to the biotic component, the proposal includes the establishment and monitoring of biotic integrity indices for four aquatic communities (periphyton, macro invertebrates, riparian vegetation, and fish). The effects that flow reduction may produce in the medium and long term can be assessed by these indices. We present the results of applying the methodology to several projects licensed by the MADS.

  14. ESTIMATING THE PARAMETERS OF SAGITTARIUS A*'s ACCRETION FLOW VIA MILLIMETER VLBI

    Energy Technology Data Exchange (ETDEWEB)

    Broderick, Avery E [Canadian Institute for Theoretical Astrophysics, 60 St. George St., Toronto, ON M5S 3H8 (Canada); Fish, Vincent L; Doeleman, Sheperd S [Massachusetts Institute of Technology, Haystack Observatory, Route 40, Westford, MA 01886 (United States); Loeb, Abraham [Institute for Theory and Computation, Harvard University, Center for Astrophysics, 60 Garden St., Cambridge, MA 02138 (United States)

    2009-05-20

    Recent millimeter-VLBI observations of Sagittarius A* (Sgr A*) have, for the first time, directly probed distances comparable to the horizon scale of a black hole. This provides unprecedented access to the environment immediately around the horizon of an accreting black hole. We leverage both existing spectral and polarization measurements and our present understanding of accretion theory to produce a suite of generic radiatively inefficient accretion flow (RIAF) models of Sgr A*, which we then fit to these recent millimeter-VLBI observations. We find that if the accretion flow onto Sgr A* is well described by an RIAF model, the orientation and magnitude of the black hole's spin are constrained to a two-dimensional surface in the spin, inclination, position angle parameter space. For each of these, we find the likeliest values and their 1{sigma} and 2{sigma} errors to be a = 0{sup +0.4+0.7}, {theta}=50{sup o+10{sup o}}{sup +30{sup o}}{sub -10{sup o}}{sub -10{sup o}}, and {xi}=-20{sup o+31{sup o}}{sup +107{sup o}}{sub -16{sup o}}{sub -29{sup o}}, when the resulting probability distribution is marginalized over the others. The most probable combination is a = 0{sup +0.2+0.4}, {theta}=90{sup o}{sub -40{sup o}}{sub -50{sup o}}, and {xi}=-14{sup o+7{sup o}}{sup +11{sup o}}{sub -7{sup o}}{sub -11{sup o}}, though the uncertainties on these are very strongly correlated, and high probability configurations exist for a variety of inclination angles above 30 deg. and spins below 0.99. Nevertheless, this demonstrates the ability millimeter-VLBI observations, even with only a few stations, to significantly constrain the properties of Sgr A*.

  15. Estimation of Resource Productivity and Efficiency: An Extended Evaluation of Sustainability Related to Material Flow

    Directory of Open Access Journals (Sweden)

    Pin-Chih Wang

    2014-09-01

    Full Text Available This study is intended to conduct an extended evaluation of sustainability based on the material flow analysis of resource productivity. We first present updated information on the material flow analysis (MFA database in Taiwan. Essential indicators are selected to quantify resource productivity associated with the economy-wide MFA of Taiwan. The study also applies the IPAT (impact-population-affluence-technology master equation to measure trends of material use efficiency in Taiwan and to compare them with those of other Asia-Pacific countries. An extended evaluation of efficiency, in comparison with selected economies by applying data envelopment analysis (DEA, is conducted accordingly. The Malmquist Productivity Index (MPI is thereby adopted to quantify the patterns and the associated changes of efficiency. Observations and summaries can be described as follows. Based on the MFA of the Taiwanese economy, the average growth rates of domestic material input (DMI; 2.83% and domestic material consumption (DMC; 2.13% in the past two decades were both less than that of gross domestic product (GDP; 4.95%. The decoupling of environmental pressures from economic growth can be observed. In terms of the decomposition analysis of the IPAT equation and in comparison with 38 other economies, the material use efficiency of Taiwan did not perform as well as its economic growth. The DEA comparisons of resource productivity show that Denmark, Germany, Luxembourg, Malta, Netherlands, United Kingdom and Japan performed the best in 2008. Since the MPI consists of technological change (frontier-shift or innovation and efficiency change (catch-up, the change in efficiency (catch-up of Taiwan has not been accomplished as expected in spite of the increase in its technological efficiency.

  16. Model Related Estimates of time dependent quantiles of peak flows - case study for selected catchments in Poland

    Science.gov (United States)

    Strupczewski, Witold G.; Bogdanowich, Ewa; Debele, Sisay

    2016-04-01

    Under Polish climate conditions the series of Annual Maxima (AM) flows are usually a mixture of peak flows of thaw- and rainfall- originated floods. The northern, lowland regions are dominated by snowmelt floods whilst in mountainous regions the proportion of rainfall floods is predominant. In many stations the majority of AM can be of snowmelt origin, but the greatest peak flows come from rainfall floods or vice versa. In a warming climate, precipitation is less likely to occur as snowfall. A shift from a snow- towards a rain-dominated regime results in a decreasing trend in mean and standard deviations of winter peak flows whilst rainfall floods do not exhibit any trace of non-stationarity. That is why a simple form of trends (i.e. linear trends) are more difficult to identify in AM time-series than in Seasonal Maxima (SM), usually winter season time-series. Hence it is recommended to analyse trends in SM, where a trend in standard deviation strongly influences the time -dependent upper quantiles. The uncertainty associated with the extrapolation of the trend makes it necessary to apply a relationship for trend which has time derivative tending to zero, e.g. we can assume a new climate equilibrium epoch approaching, or a time horizon is limited by the validity of the trend model. For both winter and summer SM time series, at least three distributions functions with trend model in the location, scale and shape parameters are estimated by means of the GAMLSS package using the ML-techniques. The resulting trend estimates in mean and standard deviation are mutually compared to the observed trends. Then, using AIC measures as weights, a multi-model distribution is constructed for each of two seasons separately. Further, assuming a mutual independence of the seasonal maxima, an AM model with time-dependent parameters can be obtained. The use of a multi-model approach can alleviate the effects of different and often contradictory trends obtained by using and identifying

  17. Individual, contextual and network characteristics of blood donors and non-donors: a systematic review of recent literature

    Science.gov (United States)

    Piersma, Tjeerd W.; Bekkers, René; Klinkenberg, Elisabeth F.; de Kort, Wim L.A.M.; Merz, Eva-Maria

    2017-01-01

    Background The ageing population and recent migration flows may negatively affect the blood supply in the long term, increasing the importance of targeted recruitment and retention strategies to address donors. This review sought to identify individual, network and contextual characteristics related to blood donor status and behaviour, to systematically discuss differences between study results, and to identify possible factors to target in recruitment and retention efforts. Methods The systematic review was conducted in accordance with a predefined PROSPERO protocol (CRD42016039591). After quality assessments by multiple independent raters, a final set of 66 peer-reviewed papers, published between October 2009 and January 2017, were included for review. Results Individual and contextual characteristics of blood donor status and behaviour were categorised into five main lines of research: donor demographics, motivations and barriers, adverse reactions and deferral, contextual factors, and blood centre factors. Results on donor demographics, motivations and barriers, and contextual factors were inconclusive, differing between studies, countries, and sample characteristics. Adverse reactions and deferral were negatively related to blood donor behaviour. Blood centre factors play an important role in donor management, e.g., providing information, reminders, and (non-)monetary rewards. No studies were found on network characteristics of (non-)donors. Discussion Although individual and contextual characteristics strongly relate to blood donor status and behaviour, mechanisms underlying these relations have not been studied sufficiently. We want to stress the importance of longitudinal studies in donor behaviour, exploring the role of life events and network characteristics within blood donor careers. Increased understanding of donor behaviour will assist policy makers of blood collection agencies, with the ultimate goal of safeguarding a sufficient and matching blood

  18. Individual, contextual and network characteristics of blood donors and non-donors: a systematic review of recent literature.

    Science.gov (United States)

    Piersma, Tjeerd W; Bekkers, René; Klinkenberg, Elisabeth F; De Kort, Wim L A M; Merz, Eva-Maria

    2017-09-01

    The ageing population and recent migration flows may negatively affect the blood supply in the long term, increasing the importance of targeted recruitment and retention strategies to address donors. This review sought to identify individual, network and contextual characteristics related to blood donor status and behaviour, to systematically discuss differences between study results, and to identify possible factors to target in recruitment and retention efforts. The systematic review was conducted in accordance with a predefined PROSPERO protocol (CRD42016039591). After quality assessments by multiple independent raters, a final set of 66 peer-reviewed papers, published between October 2009 and January 2017, were included for review. Individual and contextual characteristics of blood donor status and behaviour were categorised into five main lines of research: donor demographics, motivations and barriers, adverse reactions and deferral, contextual factors, and blood centre factors. Results on donor demographics, motivations and barriers, and contextual factors were inconclusive, differing between studies, countries, and sample characteristics. Adverse reactions and deferral were negatively related to blood donor behaviour. Blood centre factors play an important role in donor management, e.g., providing information, reminders, and (non-)monetary rewards. No studies were found on network characteristics of (non-)donors. Although individual and contextual characteristics strongly relate to blood donor status and behaviour, mechanisms underlying these relations have not been studied sufficiently. We want to stress the importance of longitudinal studies in donor behaviour, exploring the role of life events and network characteristics within blood donor careers. Increased understanding of donor behaviour will assist policy makers of blood collection agencies, with the ultimate goal of safeguarding a sufficient and matching blood supply.

  19. Estimation and Control of Networked Distributed Parameter Systems: Application to Traffic Flow

    KAUST Repository

    Canepa, Edward

    2016-11-01

    The management of large-scale transportation infrastructure is becoming a very complex task for the urban areas of this century which are covering bigger geographic spaces and facing the inclusion of connected and self-controlled vehicles. This new system paradigm can leverage many forms of sensing and interaction, including a high-scale mobile sensing approach. To obtain a high penetration sensing system on urban areas more practical and scalable platforms are needed, combined with estimation algorithms suitable to the computational capabilities of these platforms. The purpose of this work was to develop a transportation framework that is able to handle different kinds of sensing data (e.g., connected vehicles, loop detectors) and optimize the traffic state on a defined traffic network. The framework estimates the traffic on road networks modeled by a family of Lighthill-Whitham-Richards equations. Based on an equivalent formulation of the problem using a Hamilton-Jacobi equation and using a semi-analytic formula, I will show that the model constraints resulting from the Hamilton-Jacobi equation are linear, albeit with unknown integer variables. This general framework solve exactly a variety of problems arising in transportation networks: traffic estimation, traffic control (including robust control), cybersecurity and sensor fault detection, or privacy analysis of users in probe-based traffic monitoring systems. This framework is very flexible, fast, and yields exact results. The recent advances in sensors (GPS, inertial measurement units) and microprocessors enable the development low-cost dedicated devices for traffic sensing in cities, 5 which are highly scalable, providing a feasible solution to cover large urban areas. However, one of the main problems to address is the privacy of the users of the transportation system, the framework presented here is a viable option to guarantee the privacy of the users by design.

  20. Theoretical estimation of Photons flow rate Production in quark gluon interaction at high energies

    Science.gov (United States)

    Al-Agealy, Hadi J. M.; Hamza Hussein, Hyder; Mustafa Hussein, Saba

    2018-05-01

    photons emitted from higher energetic collisions in quark-gluon system have been theoretical studied depending on color quantum theory. A simple model for photons emission at quark-gluon system have been investigated. In this model, we use a quantum consideration which enhances to describing the quark system. The photons current rate are estimation for two system at different fugacity coefficient. We discussion the behavior of photons rate and quark gluon system properties in different photons energies with Boltzmann model. The photons rate depending on anisotropic coefficient : strong constant, photons energy, color number, fugacity parameter, thermal energy and critical energy of system are also discussed.

  1. Observing expertise-related actions leads to perfect time flow estimations.

    Directory of Open Access Journals (Sweden)

    Yin-Hua Chen

    Full Text Available The estimation of the time of exposure of a picture portraying an action increases as a function of the amount of movement implied in the action represented. This effect suggests that the perceiver creates an internal embodiment of the action observed as if internally simulating the entire movement sequence. Little is known however about the timing accuracy of these internal action simulations, specifically whether they are affected by the level of familiarity and experience that the observer has of the action. In this study we asked professional pianists to reproduce different durations of exposure (shorter or longer than one second of visual displays both specific (a hand in piano-playing action and non-specific to their domain of expertise (a hand in finger-thumb opposition and scrambled-pixels and compared their performance with non-pianists. Pianists outperformed non-pianists independently of the time of exposure of the stimuli; remarkably the group difference was particularly magnified by the pianists' enhanced accuracy and stability only when observing the hand in the act of playing the piano. These results for the first time provide evidence that through musical training, pianists create a selective and self-determined dynamic internal representation of an observed movement that allows them to estimate precisely its temporal duration.

  2. Development of flood regressions and climate change scenarios to explore estimates of future peak flows

    Science.gov (United States)

    Burns, Douglas A.; Smith, Martyn J.; Freehafer, Douglas A.

    2015-12-31

    A new Web-based application, titled “Application of Flood Regressions and Climate Change Scenarios To Explore Estimates of Future Peak Flows”, has been developed by the U.S. Geological Survey, in cooperation with the New York State Department of Transportation, that allows a user to apply a set of regression equations to estimate the magnitude of future floods for any stream or river in New York State (exclusive of Long Island) and the Lake Champlain Basin in Vermont. The regression equations that are the basis of the current application were developed in previous investigations by the U.S. Geological Survey (USGS) and are described at the USGS StreamStats Web sites for New York (http://water.usgs.gov/osw/streamstats/new_york.html) and Vermont (http://water.usgs.gov/osw/streamstats/Vermont.html). These regression equations include several fixed landscape metrics that quantify aspects of watershed geomorphology, basin size, and land cover as well as a climate variable—either annual precipitation or annual runoff.

  3. Kidney transplantation from donors with rhabdomyolysis and acute renal failure.

    Science.gov (United States)

    Chen, Chuan-Bao; Zheng, Yi-Tao; Zhou, Jian; Han, Ming; Wang, Xiao-Ping; Yuan, Xiao-Peng; Wang, Chang-Xi; He, Xiao-Shun

    2017-08-01

    Rhabdomyolysis in deceased donors usually causes acute renal failure (ARF), which may be considered a contraindication for kidney transplantation. From January 2012 to December 2016, 30 kidneys from 15 deceased donors with severe rhabdomyolysis and ARF were accepted for transplantation at our center. The peak serum creatinine (SCr) kinase, myoglobin, and SCr of the these donors were 15 569±8597 U/L, 37 092±42 100 μg/L, and 422±167 μmol/L, respectively. Two donors received continuous renal replacement therapy due to anuria. Six kidneys exhibited a discolored appearance (from brown to glossy black) due to myoglobin casts. The kidney transplant results from the donors with rhabdomyolysis donors were compared with those of 90 renal grafts from standard criteria donors (SCD). The estimated glomerular filtration rate at 2 years was similar between kidney transplants from donors with rhabdomyolysis and SCD (70.3±14.6 mL/min/1.73 m 2 vs 72.3±15.1 mL/min/1.73 m 2 ). We conclude that excellent graft function can be achieved from kidneys donors with ARF caused by rhabdomyolysis. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  4. OPTICAL FLOW APPLIED TO TIME-LAPSE IMAGE SERIES TO ESTIMATE GLACIER MOTION IN THE SOUTHERN PATAGONIA ICE FIELD

    Directory of Open Access Journals (Sweden)

    E. Lannutti

    2016-06-01

    Full Text Available In this work, we assessed the feasibility of using optical flow to obtain the motion estimation of a glacier. In general, former investigations used to detect glacier changes involve solutions that require repeated observations which are many times based on extensive field work. Taking into account glaciers are usually located in geographically complex and hard to access areas, deploying time-lapse imaging sensors, optical flow may provide an efficient solution at good spatial and temporal resolution to describe mass motion. Several studies in computer vision and image processing community have used this method to detect large displacements. Therefore, we carried out a test of the proposed Large Displacement Optical Flow method at the Viedma Glacier, located at South Patagonia Icefield, Argentina. We collected monoscopic terrestrial time-lapse imagery, acquired by a calibrated camera at every 24 hour from April 2014 until April 2015. A filter based on temporal correlation and RGB color discretization between the images was applied to minimize errors related to changes in lighting, shadows, clouds and snow. This selection allowed discarding images that do not follow a sequence of similarity. Our results show a flow field in the direction of the glacier movement with acceleration in the terminus. We analyzed the errors between image pairs, and the matching generally appears to be adequate, although some areas show random gross errors related to the presence of changes in lighting. The proposed technique allowed the determination of glacier motion during one year, providing accurate and reliable motion data for subsequent analysis.

  5. Spacecraft angular velocity estimation algorithm for star tracker based on optical flow techniques

    Science.gov (United States)

    Tang, Yujie; Li, Jian; Wang, Gangyi

    2018-02-01

    An integrated navigation system often uses the traditional gyro and star tracker for high precision navigation with the shortcomings of large volume, heavy weight and high-cost. With the development of autonomous navigation for deep space and small spacecraft, star tracker has been gradually used for attitude calculation and angular velocity measurement directly. At the same time, with the dynamic imaging requirements of remote sensing satellites and other imaging satellites, how to measure the angular velocity in the dynamic situation to improve the accuracy of the star tracker is the hotspot of future research. We propose the approach to measure angular rate with a nongyro and improve the dynamic performance of the star tracker. First, the star extraction algorithm based on morphology is used to extract the star region, and the stars in the two images are matched according to the method of angular distance voting. The calculation of the displacement of the star image is measured by the improved optical flow method. Finally, the triaxial angular velocity of the star tracker is calculated by the star vector using the least squares method. The method has the advantages of fast matching speed, strong antinoise ability, and good dynamic performance. The triaxial angular velocity of star tracker can be obtained accurately with these methods. So, the star tracker can achieve better tracking performance and dynamic attitude positioning accuracy to lay a good foundation for the wide application of various satellites and complex space missions.

  6. Ensemble/Variational Estimation (EnVE) and its application to canonical turbulent flow realizations

    Science.gov (United States)

    Colburn, Christopher; Cessna, Joseph; Bewley, Thomas

    2008-11-01

    The recently-developed hybrid EnVE method for data assimilation incorporates successive adjoint optimizations to update the initial conditions of a flow model, over various horizons of interest, in order to reconcile this model with recent measurements. Such adjoint optimizations typically require the trajectory to be saved over the entire interval over which the optimization is performed; in high-dimensional systems, this can lead to significant storage problems, which can be partially alleviated via checkpointing. In the EnVE framework, this requirement is eliminated, and supplanted by a requirement to march the state of the system backward in time simultaneously with the adjoint. If the system is derived from a PDE with a diffusive component, this backward-in-time state march is ill conditioned, and requires regularization/smoothing to prevent errors from accumulating rapidly at the small scales. The present talk focuses on this peculiar requirement of the EnVE algorithm. As the forecasting problem may itself be considered as a smoothing problem, it is, in fact, expected to find a ``smoothing'' ingredient at the heart of an algorithm of this sort. Various strategies are proposed and tested for accomplishing the required smoothing in the EnVE setting, and are tested on both a chaotic 1D PDE (the Kuramoto-Sivashinsky equation) as well as our in-house spectral 3D DNS/LES code, diablo.

  7. Multi-processor system for real-time deconvolution and flow estimation in medical ultrasound

    DEFF Research Database (Denmark)

    Jensen, Jesper Lomborg; Jensen, Jørgen Arendt; Stetson, Paul F.

    1996-01-01

    of the algorithms. Many of the algorithms can only be properly evaluated in a clinical setting with real-time processing, which generally cannot be done with conventional equipment. This paper therefore presents a multi-processor system capable of performing 1.2 billion floating point operations per second on RF...... filter is used with a second time-reversed recursive estimation step. Here it is necessary to perform about 70 arithmetic operations per RF sample or about 1 billion operations per second for real-time deconvolution. Furthermore, these have to be floating point operations due to the adaptive nature...... interfaced to our previously-developed real-time sampling system that can acquire RF data at a rate of 20 MHz and simultaneously transmit the data at 20 MHz to the processing system via several parallel channels. These two systems can, thus, perform real-time processing of ultrasound data. The advantage...

  8. CUFID-query: accurate network querying through random walk based network flow estimation.

    Science.gov (United States)

    Jeong, Hyundoo; Qian, Xiaoning; Yoon, Byung-Jun

    2017-12-28

    Functional modules in biological networks consist of numerous biomolecules and their complicated interactions. Recent studies have shown that biomolecules in a functional module tend to have similar interaction patterns and that such modules are often conserved across biological networks of different species. As a result, such conserved functional modules can be identified through comparative analysis of biological networks. In this work, we propose a novel network querying algorithm based on the CUFID (Comparative network analysis Using the steady-state network Flow to IDentify orthologous proteins) framework combined with an efficient seed-and-extension approach. The proposed algorithm, CUFID-query, can accurately detect conserved functional modules as small subnetworks in the target network that are expected to perform similar functions to the given query functional module. The CUFID framework was recently developed for probabilistic pairwise global comparison of biological networks, and it has been applied to pairwise global network alignment, where the framework was shown to yield accurate network alignment results. In the proposed CUFID-query algorithm, we adopt the CUFID framework and extend it for local network alignment, specifically to solve network querying problems. First, in the seed selection phase, the proposed method utilizes the CUFID framework to compare the query and the target networks and to predict the probabilistic node-to-node correspondence between the networks. Next, the algorithm selects and greedily extends the seed in the target network by iteratively adding nodes that have frequent interactions with other nodes in the seed network, in a way that the conductance of the extended network is maximally reduced. Finally, CUFID-query removes irrelevant nodes from the querying results based on the personalized PageRank vector for the induced network that includes the fully extended network and its neighboring nodes. Through extensive

  9. Estimation of myocardial blood flow and myocardial flow reserve by 99mTc-sestamibi imaging: comparison with the results of [15O]H2O PET

    International Nuclear Information System (INIS)

    Ito, Yoshinori; Noriyasu, Kazuyuki; Kohya, Tetsuro; Kitabatake, Akira; Katoh, Chietsugu; Kuge, Yuji; Furuyama, Hideto; Morita, Koichi; Tamaki, Nagara

    2003-01-01

    We developed a noninvasive method to quantitatively estimate the myocardial blood flow (MBF) index and flow reserve (MFR) using dynamic and static data obtained with technetium-99m sestamibi, and compared the results with MBF and MFR measured by oxygen-15-labeled water ([ 15 O]H 2 O) PET. Twenty patients with coronary artery disease (CAD) and nine normal subjects underwent both 99m Tc-sestamibi and PET studies within 2 weeks. From the anterior view, dynamic data were acquired for 2 min immediately after the injection of 99m Tc-sestamibi, and planar static images were also obtained after 5 min at rest and during ATP stress (0.16 mg kg -1 min -1 for 5 min) on another day. The area under the time-activity curve on the aortic arch (Aorta ACU), myocardial weight with the SPET image (M), and the myocardial count on the planar image for 1 min (C m ) were obtained. The MBF index (MBFI) was calculated as follows: MBFI=C m /Aorta ACU x 100/M. MFR was measured by dividing the MBFI at ATP stress by MBFI at rest. The MBFI measured by 99m Tc-sestamibi was significantly correlated with MBF obtained using [ 15 O]H 2 O PET (MBFI=13.174+11.732 x MBF, r=0.821, P 99m Tc-sestamibi was well correlated with that obtained using [ 15 O]H 2 O PET, with some underestimation (r=0.845, P 99m Tc-sestamibi in patients with CAD was significantly lower than that in normal subjects (CAD: 1.484±0.256 vs normal: 2.127±0.308, P 99m Tc-sestamibi. This may be useful for the quantitative assessment of CAD, especially in those patients with diffuse coronary disease. (orig.)

  10. A New Approximate Chimera Donor Cell Search Algorithm

    Science.gov (United States)

    Holst, Terry L.; Nixon, David (Technical Monitor)

    1998-01-01

    The objectives of this study were to develop chimera-based full potential methodology which is compatible with overflow (Euler/Navier-Stokes) chimera flow solver and to develop a fast donor cell search algorithm that is compatible with the chimera full potential approach. Results of this work included presenting a new donor cell search algorithm suitable for use with a chimera-based full potential solver. This algorithm was found to be extremely fast and simple producing donor cells as fast as 60,000 per second.

  11. Uncertainty estimation with bias-correction for flow series based on rating curve

    Science.gov (United States)

    Shao, Quanxi; Lerat, Julien; Podger, Geoff; Dutta, Dushmanta

    2014-03-01

    Streamflow discharge constitutes one of the fundamental data required to perform water balance studies and develop hydrological models. A rating curve, designed based on a series of concurrent stage and discharge measurements at a gauging location, provides a way to generate complete discharge time series with a reasonable quality if sufficient measurement points are available. However, the associated uncertainty is frequently not available even though it has a significant impact on hydrological modelling. In this paper, we identify the discrepancy of the hydrographers' rating curves used to derive the historical discharge data series and proposed a modification by bias correction which is also in the form of power function as the traditional rating curve. In order to obtain the uncertainty estimation, we propose a further both-side Box-Cox transformation to stabilize the regression residuals as close to the normal distribution as possible, so that a proper uncertainty can be attached for the whole discharge series in the ensemble generation. We demonstrate the proposed method by applying it to the gauging stations in the Flinders and Gilbert rivers in north-west Queensland, Australia.

  12. Intra-Urban Movement Flow Estimation Using Location Based Social Networking Data

    Science.gov (United States)

    Kheiri, A.; Karimipour, F.; Forghani, M.

    2015-12-01

    In recent years, there has been a rapid growth of location-based social networking services, such as Foursquare and Facebook, which have attracted an increasing number of users and greatly enriched their urban experience. Location-based social network data, as a new travel demand data source, seems to be an alternative or complement to survey data in the study of mobility behavior and activity analysis because of its relatively high access and low cost. In this paper, three OD estimation models have been utilized in order to investigate their relative performance when using Location-Based Social Networking (LBSN) data. For this, the Foursquare LBSN data was used to analyze the intra-urban movement behavioral patterns for the study area, Manhattan, the most densely populated of the five boroughs of New York city. The outputs of models are evaluated using real observations based on different criterions including distance distribution, destination travel constraints. The results demonstrate the promising potential of using LBSN data for urban travel demand analysis and monitoring.

  13. INTRA-URBAN MOVEMENT FLOW ESTIMATION USING LOCATION BASED SOCIAL NETWORKING DATA

    Directory of Open Access Journals (Sweden)

    A. Kheiri

    2015-12-01

    Full Text Available In recent years, there has been a rapid growth of location-based social networking services, such as Foursquare and Facebook, which have attracted an increasing number of users and greatly enriched their urban experience. Location-based social network data, as a new travel demand data source, seems to be an alternative or complement to survey data in the study of mobility behavior and activity analysis because of its relatively high access and low cost. In this paper, three OD estimation models have been utilized in order to investigate their relative performance when using Location-Based Social Networking (LBSN data. For this, the Foursquare LBSN data was used to analyze the intra-urban movement behavioral patterns for the study area, Manhattan, the most densely populated of the five boroughs of New York city. The outputs of models are evaluated using real observations based on different criterions including distance distribution, destination travel constraints. The results demonstrate the promising potential of using LBSN data for urban travel demand analysis and monitoring.

  14. Cancer Incidence and Mortality in a Cohort of US Blood Donors: A 20-Year Study

    International Nuclear Information System (INIS)

    Vahidnia, F.; Busch, M. P.; Custer, B.; Hirschler, N. V.; Chinn, A.; Agapova, M.; Busch, M. P.; Custer, B.

    2013-01-01

    Blood donors are considered one of the healthiest populations. This study describes the epidemiology of cancer in a cohort of blood donors up to 20 years after blood donation. Records from donors who participated in the Retroviral Epidemiology Donor Study (REDS, 1991-2002) at Blood Centers of the Pacific (BCP), San Francisco, were linked to the California Cancer Registry (CCR, 1991-2010). Standardized incidence ratios (SIR) were estimated using standard US 2000 population, and survival analysis used to compare all-cause mortality among donors and a random sample of non donors with cancer from CCR. Of 55,158 eligible allogeneic blood donors followed-up for 863,902 person-years, 4,236 (7.7%) primary malignant cancers were diagnosed. SIR in donors was 1.59 (95% CI = 1.54,1.64). Donors had significantly lower mortality (adjusted HR = 0.70, 95% CI = 0.66-0.74) compared with non donor cancer patients, except for respiratory system cancers (adjusted HR = 0.93, 95% CI = 0.82-1.05). Elevated cancer incidence among blood donors may reflect higher diagnosis rates due to health seeking behavior and cancer screening in donors. A “healthy donor effect” on mortality following cancer diagnosis was demonstrated. This population-based database and sample repository of blood donors with long-term monitoring of cancer incidence provides the opportunity for future analyses of genetic and other bio markers of cancer

  15. Evaluation of the return rate of volunteer blood donors

    Directory of Open Access Journals (Sweden)

    Adriana de Fátima Lourençon

    2011-06-01

    Full Text Available BACKGROUND: To convert first-time blood donors into regular volunteer donors is a challenge to transfusion services. OBJECTIVES: This study aims to estimate the return rate of first time donors of the Ribeirão Preto Blood Center and of other blood centers in its coverage region. METHODS: The histories of 115,553 volunteer donors between 1996 and 2005 were analyzed. Statistical analysis was based on a parametric long-term survival model that allows an estimation of the proportion of donors who never return for further donations. RESULTS: Only 40% of individuals return within one year after the first donation and 53% return within two years. It is estimated that 30% never return to donate. Higher return rates were observed among Black donors. No significant difference was found in non-return rates regarding gender, blood type, Rh blood group and blood collection unit. CONCLUSIONS: The low percentage of first-time donors who return for further blood donation reinforces the need for marketing actions and strategies aimed at increasing the return rates.

  16. Methods for estimating magnitude and frequency of floods in Arizona, developed with unregulated and rural peak-flow data through water year 2010

    Science.gov (United States)

    Paretti, Nicholas V.; Kennedy, Jeffrey R.; Turney, Lovina A.; Veilleux, Andrea G.

    2014-01-01

    Flooding is among the worst natural disasters responsible for loss of life and property in Arizona, underscoring the importance of accurate estimation of flood magnitude for proper structural design and floodplain mapping. Twenty-four years of additional peak-flow data have been recorded since the last comprehensive regional flood frequency analysis conducted in Arizona. Periodically, flood frequency estimates and regional regression equations must be revised to maintain the accurate estimation of flood frequency and magnitude.

  17. Development and validation of a CFD based methodology to estimate the pressure loss of flow through perforated plates

    International Nuclear Information System (INIS)

    Barros Filho, Jose A.; Navarro, Moyses A.; Santos, Andre A.C. dos; Jordao, E.

    2011-01-01

    In spite of the recent great development of Computational Fluid Dynamics (CFD), there are still some issues about how to assess its accurateness. This work presents the validation of a CFD methodology devised to estimate the pressure drop of water flow through perforated plates similar to the ones used in some reactor core components. This was accomplished by comparing the results of CFD simulations against experimental data of 5 perforated plates with different geometric characteristics. The proposed methodology correlates the experimental data within a range of ± 7.5%. The validation procedure recommended by the ASME Standard for Verification and Validation in Computational Fluid Dynamics and Heat Transfer-V and V 20 is also evaluated. The conclusion is that it is not adequate to this specific use. (author)

  18. Are drowned donors marginal donors? A single pediatric center experience.

    Science.gov (United States)

    Kumm, Kayla R; Galván, N Thao N; Koohmaraie, Sarah; Rana, Abbas; Kueht, Michael; Baugh, Katherine; Hao, Liu; Yoeli, Dor; Cotton, Ronald; O'Mahony, Christine A; Goss, John A

    2017-09-01

    Drowning, a common cause of death in the pediatric population, is a potentially large donor pool for OLT. Anecdotally, transplant centers have deemed these organs high risk over concerns for infection and graft dysfunction. We theorized drowned donor liver allografts do not portend worse outcomes and therefore should not be excluded from the donation pool. We reviewed our single-center experience of pediatric OLTs between 1988 and 2015 and identified 33 drowned donor recipients. These OLTs were matched 1:2 to head trauma donor OLTs from our center. A chart review assessed postoperative peak AST and ALT, incidence of HAT, graft and recipient survival. Recipient survival at one year between patients with drowned donor vs head trauma donor allografts was not statistically significant (94% vs 97%, P=.63). HAT incidence was 6.1% in the drowned donor group vs 7.6% in the control group (P=.78). Mean postoperative peak AST and ALT was 683 U/L and 450 U/L for drowned donors vs 1119 U/L and 828 U/L in the matched cohort. These results suggest drowned donor liver allografts do not portend worse outcomes in comparison with those procured from head trauma donors. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  19. Estimation of coronary flow reserve by sestamibi imaging in patients with mild hypertension and normal coronary arteries

    International Nuclear Information System (INIS)

    Storto, G.; Gallicchio, R.; Maddalena, F.; Pellegrino, T.; Petretta, M.; Fiumara, G.; Cuocolo, A.

    2015-01-01

    Patients with hypertension may exhibit abnormal vasodilator capacity during pharmacological vasodilatation. We assessed coronary flow reserve (CFR) by sestamibi imaging in hypertensive patients with normal coronary vessels. Twenty-five patients with untreated mild essential hypertension and normal coronary vessels and 10 control subjects underwent dipyridamole-rest Tc-99m sestamibi imaging. Myocardial blood flow (MBF) was estimated by measuring first transit counts in pulmonary artery and myocardial counts from tomograhic images. CFR was expressed as the ratio of stress to rest MBF. Coronary vascular resistances (CVR) were computed as the ratio between mean arterial pressure and MBF. Estimated MBF at rest was not different in patients and controls (1.11±0.59 vs. 1.14±0.28 counts/pixel/s; P=0.87). Conversely, stress MBF was lower in patients than in controls (1.55±0.47 vs. 2.68±0.53 counts/pixel/s; P<0.001). Thus, CFR was reduced in patients compared to controls (1.61±0.58 vs. 2.43±0.62; P<0.001). Rest and stress CVR values were higher in patients (P<0.001), while stress-induced changes in CVR were not different (P=0.08) between patients (-51%) and controls (-62%). In the overall study population, a significant relation between CFR and stress-induced changes in CVR was observed (r=-0.86; P<0.001). Sestamibi imaging may detect impaired coronary vascular function in response to dipyridamole in patients with untreated mild essential hypertension and normal coronary arteries. A mild increase in arterial blood pressure does not affect baseline MBF, but impairs coronary reserve due to the amplified resting coronary resistances.

  20. Does manipulating the speed of visual flow in virtual reality change distance estimation while walking in Parkinson's disease?

    Science.gov (United States)

    Ehgoetz Martens, Kaylena A; Ellard, Colin G; Almeida, Quincy J

    2015-03-01

    Although dopaminergic replacement therapy is believed to improve sensory processing in PD, while delayed perceptual speed is thought to be caused by a predominantly cholinergic deficit, it is unclear whether sensory-perceptual deficits are a result of corrupt sensory processing, or a delay in updating perceived feedback during movement. The current study aimed to examine these two hypotheses by manipulating visual flow speed and dopaminergic medication to examine which influenced distance estimation in PD. Fourteen PD and sixteen HC participants were instructed to estimate the distance of a remembered target by walking to the position the target formerly occupied. This task was completed in virtual reality in order to manipulate the visual flow (VF) speed in real time. Three conditions were carried out: (1) BASELINE: VF speed was equal to participants' real-time movement speed; (2) SLOW: VF speed was reduced by 50 %; (2) FAST: VF speed was increased by 30 %. Individuals with PD performed the experiment in their ON and OFF state. PD demonstrated significantly greater judgement error during BASELINE and FAST conditions compared to HC, although PD did not improve their judgement error during the SLOW condition. Additionally, PD had greater variable error during baseline compared to HC; however, during the SLOW conditions, PD had significantly less variable error compared to baseline and similar variable error to HC participants. Overall, dopaminergic medication did not significantly influence judgement error. Therefore, these results suggest that corrupt processing of sensory information is the main contributor to sensory-perceptual deficits during movement in PD rather than delayed updating of sensory feedback.

  1. Estimating the energy-saving benefit of reduced-flow and/or multi-speed commercial kitchen ventilation systems

    Energy Technology Data Exchange (ETDEWEB)

    Fisher, D.; Schmid, F.; Spata, A.J.

    1999-07-01

    Kitchen exhaust ventilation systems are recognized as a major energy user within commercial food service facilities and restaurants. Minimizing the design ventilation rate of an appliance/hood system by optimizing hood performance in the laboratory is a viable strategy for reducing the makeup air heating and cooling loads as well as the exhaust and supply fan energy. Cutting back the exhaust flow under conditions of noncooking (appliance idle) can further reduce the energy load associated with a kitchen ventilation system. An optimized, two-speed exhaust system was installed within the scope of an energy-efficient, quick service restaurant (QSR) design and demonstration project. This paper evaluates the energy benefit of this variable-flow strategy as well as the savings associated with reducing the design ventilation rate (compared to an off-the-shelf exhaust hood). The paper describes a new public-domain software tool for estimating heating and cooling loads associated with the makeup air requirements of commercial kitchens. This bin-based software provides ASHRAE engineers with an alternative to hand calculations or more sophisticated hour-by-hour simulation. The dramatic impact that both makeup air set point and geographic location have on the outdoor air load is illustrated. The paper concludes with an industry-wide projection of energy savings associated with optimizing the design and operation of commercial kitchen ventilation (CKV) systems.

  2. A hybrid EKF and switching PSO algorithm for joint state and parameter estimation of lateral flow immunoassay models.

    Science.gov (United States)

    Zeng, Nianyin; Wang, Zidong; Li, Yurong; Du, Min; Liu, Xiaohui

    2012-01-01

    In this paper, a hybrid extended Kalman filter (EKF) and switching particle swarm optimization (SPSO) algorithm is proposed for jointly estimating both the parameters and states of the lateral flow immunoassay model through available short time-series measurement. Our proposed method generalizes the well-known EKF algorithm by imposing physical constraints on the system states. Note that the state constraints are encountered very often in practice that give rise to considerable difficulties in system analysis and design. The main purpose of this paper is to handle the dynamic modeling problem with state constraints by combining the extended Kalman filtering and constrained optimization algorithms via the maximization probability method. More specifically, a recently developed SPSO algorithm is used to cope with the constrained optimization problem by converting it into an unconstrained optimization one through adding a penalty term to the objective function. The proposed algorithm is then employed to simultaneously identify the parameters and states of a lateral flow immunoassay model. It is shown that the proposed algorithm gives much improved performance over the traditional EKF method.

  3. Estimation of the sources and flow system of groundwater in Fuji-Gotenba area by stable isotopic analysis and groundwater flow simulation

    International Nuclear Information System (INIS)

    Tomiyama, Shingo; Miyaike, Shusaku; Ii, Hiroyuki; Hattori, Ryota; Ito, Yuji

    2009-01-01

    Understanding the source and chemical character of the groundwater provides an important strategy for the quality management of mineral water and food materials. In order to identify a source and the flow paths of groundwater used for mineral water, the water quality and stable isotopes of hydrogen and oxygen of well water in Gotenba city were studied. The electrical conductivity and chemical character of sampled water are similar to those of well water and spring water discharged elsewhere around Mt. Fuji. The hydrogen and oxygen isotopic ratios of water samples indicate their origin to be solely meteoric and the oxygen isotopic ratios suggest that the groundwater mainly originated from the mountain-side of Mt. Fuji at altitudes of from 1500 m to 2300 m. A subsequent simulation of groundwater showed that the distribution of the total head and the Darcy velocity are down streamlines from mountain-sides toward the study area in Gotenba city. The altitudes of discharge obtained by the simulation are above 2000 m, and these correspond well with altitudes estimated from δ 18 O values of the samples. (author)

  4. Iron deficiency in blood donors

    Directory of Open Access Journals (Sweden)

    Rodolfo Delfini Cançado

    Full Text Available CONTEXT: Blood donation results in a substantial loss of iron (200 to 250 mg at each bleeding procedure (425 to 475 ml and subsequent mobilization of iron from body stores. Recent reports have shown that body iron reserves generally are small and iron depletion is more frequent in blood donors than in non-donors. OBJECTIVE: The aim of this study was to evaluate the frequency of iron deficiency in blood donors and to establish the frequency of iron deficiency in blood donors according to sex, whether they were first-time or multi-time donors, and the frequency of donations per year. DESIGN: From September 20 to October 5, 1999, three hundred blood donors from Santa Casa Hemocenter of São Paulo were studied. DIAGNOSTIC TESTS: Using a combination of biochemical measurements of iron status: serum iron, total iron-binding capacity, transferrin saturation index, serum ferritin and the erythrocyte indices. RESULTS: The frequency of iron deficiency in blood donors was 11.0%, of whom 5.5% (13/237 were male and 31.7% (20/63 female donors. The frequency of iron deficiency was higher in multi-time blood donors than in first-time blood donors, for male blood donors (7.6% versus 0.0%, P < 0.05 and female ones (41.5% versus 18.5%, P < 0.05. The frequency of iron deficiency found was higher among the male blood donors with three or more donations per year (P < 0.05 and among the female blood donors with two or more donations per year (P < 0.05. CONCLUSIONS: We conclude that blood donation is a very important factor for iron deficiency in blood donors, particularly in multi-time donors and especially in female donors. The high frequency of blood donors with iron deficiency found in this study suggests a need for a more accurate laboratory trial, as hemoglobin or hematocrit measurement alone is not sufficient for detecting and excluding blood donors with iron deficiency without anemia.

  5. Regional regression equations for the estimation of selected monthly low-flow duration and frequency statistics at ungaged sites on streams in New Jersey

    Science.gov (United States)

    Watson, Kara M.; McHugh, Amy R.

    2014-01-01

    Regional regression equations were developed for estimating monthly flow-duration and monthly low-flow frequency statistics for ungaged streams in Coastal Plain and non-coastal regions of New Jersey for baseline and current land- and water-use conditions. The equations were developed to estimate 87 different streamflow statistics, which include the monthly 99-, 90-, 85-, 75-, 50-, and 25-percentile flow-durations of the minimum 1-day daily flow; the August–September 99-, 90-, and 75-percentile minimum 1-day daily flow; and the monthly 7-day, 10-year (M7D10Y) low-flow frequency. These 87 streamflow statistics were computed for 41 continuous-record streamflow-gaging stations (streamgages) with 20 or more years of record and 167 low-flow partial-record stations in New Jersey with 10 or more streamflow measurements. The regression analyses used to develop equations to estimate selected streamflow statistics were performed by testing the relation between flow-duration statistics and low-flow frequency statistics for 32 basin characteristics (physical characteristics, land use, surficial geology, and climate) at the 41 streamgages and 167 low-flow partial-record stations. The regression analyses determined drainage area, soil permeability, average April precipitation, average June precipitation, and percent storage (water bodies and wetlands) were the significant explanatory variables for estimating the selected flow-duration and low-flow frequency statistics. Streamflow estimates were computed for two land- and water-use conditions in New Jersey—land- and water-use during the baseline period of record (defined as the years a streamgage had little to no change in development and water use) and current land- and water-use conditions (1989–2008)—for each selected station using data collected through water year 2008. The baseline period of record is representative of a period when the basin was unaffected by change in development. The current period is

  6. Three-dimensional reconstruction of highly complex microscopic samples using scanning electron microscopy and optical flow estimation.

    Directory of Open Access Journals (Sweden)

    Ahmadreza Baghaie

    Full Text Available Scanning Electron Microscope (SEM as one of the major research and industrial equipment for imaging of micro-scale samples and surfaces has gained extensive attention from its emerge. However, the acquired micrographs still remain two-dimensional (2D. In the current work a novel and highly accurate approach is proposed to recover the hidden third-dimension by use of multi-view image acquisition of the microscopic samples combined with pre/post-processing steps including sparse feature-based stereo rectification, nonlocal-based optical flow estimation for dense matching and finally depth estimation. Employing the proposed approach, three-dimensional (3D reconstructions of highly complex microscopic samples were achieved to facilitate the interpretation of topology and geometry of surface/shape attributes of the samples. As a byproduct of the proposed approach, high-definition 3D printed models of the samples can be generated as a tangible means of physical understanding. Extensive comparisons with the state-of-the-art reveal the strength and superiority of the proposed method in uncovering the details of the highly complex microscopic samples.

  7. Estimation of the Arterial Fraction of Total Hepatic Flow from Radionuclide Angiogram Using 99mTc-DISIDA

    International Nuclear Information System (INIS)

    Lee, Hae Gin; Lim, Gye Yeon; Yang, Il Kwon; Kim, Hack Hee; Lim, Jung Ik; Bahk, Yong Whee; Han, Sok Won; Han, Nam Ik; Lee, Young Sok

    1991-01-01

    Arterial fraction of total hepatic blood flow was estimated by a new method, slope method, on radionuclide angiogram using 99m Tc-DISIDA and was compared with that from 99m Tc-Phytate radionuclide angiogram. This study included 11 of normal subjects, 37 of intermediate group with various liver diseases, and 25 patients with liver cirrhosis. We analyzed the data with slope method from radionuclide angiograms and the results were compared with hepatic arterial fractions from uptake method, introduced by Lee et al. at 1986. The hepatic arterial fractions from radionuclide angiograms using 99m Tc-DISIDA and 99m Tc- Phytate were 0.32 ± 0.09 and 0.31 ± 0.11 respectively in normal subjects, and 0.75 ± 0.18 and 0.77 ± 0.21 respectively in patients with liver cirrhosis. The hepatic arterial fractions by the slope method was well correlated with those of the uptake method on 99m Tc-DISIDA scan. There was high correlation between the hepatic arterial fractions from 99m Tc-DISIDA and 99m Tc-Phytate scans. Hepatic arterial fraction estimated by the slope method is a useful index for the diagnosis of liver cirrhosis and the evaluation of status of portal hypertension.

  8. Meet the donors

    DEFF Research Database (Denmark)

    Olejaz, Maria; Hoeyer, Klaus

    2016-01-01

    motivations, but rather as something made meaningful in the light of how donors understand their bodies; their social relations; and their societal position and experiences as patients in the healthcare system. The article thus contributes to the field by investigating the nature of the relationship between......For centuries, gross anatomy teaching and anatomical dissection have been fundamental elements in the training of medical doctors and surgeons across the world. Anatomy education and research rely on a stable and reliable supply of bodies in order to take place. Based on qualitative in...

  9. Crustal heat production and estimate of terrestrial heat flow in central East Antarctica, with implications for thermal input to the East Antarctic ice sheet

    Science.gov (United States)

    Goodge, John W.

    2018-02-01

    Terrestrial heat flow is a critical first-order factor governing the thermal condition and, therefore, mechanical stability of Antarctic ice sheets, yet heat flow across Antarctica is poorly known. Previous estimates of terrestrial heat flow in East Antarctica come from inversion of seismic and magnetic geophysical data, by modeling temperature profiles in ice boreholes, and by calculation from heat production values reported for exposed bedrock. Although accurate estimates of surface heat flow are important as an input parameter for ice-sheet growth and stability models, there are no direct measurements of terrestrial heat flow in East Antarctica coupled to either subglacial sediment or bedrock. As has been done with bedrock exposed along coastal margins and in rare inland outcrops, valuable estimates of heat flow in central East Antarctica can be extrapolated from heat production determined by the geochemical composition of glacial rock clasts eroded from the continental interior. In this study, U, Th, and K concentrations in a suite of Proterozoic (1.2-2.0 Ga) granitoids sourced within the Byrd and Nimrod glacial drainages of central East Antarctica indicate average upper crustal heat production (Ho) of about 2.6 ± 1.9 µW m-3. Assuming typical mantle and lower crustal heat flux for stable continental shields, and a length scale for the distribution of heat production in the upper crust, the heat production values determined for individual samples yield estimates of surface heat flow (qo) ranging from 33 to 84 mW m-2 and an average of 48.0 ± 13.6 mW m-2. Estimates of heat production obtained for this suite of glacially sourced granitoids therefore indicate that the interior of the East Antarctic ice sheet is underlain in part by Proterozoic continental lithosphere with an average surface heat flow, providing constraints on both geodynamic history and ice-sheet stability. The ages and geothermal characteristics of the granites indicate that crust in central

  10. Iron deficiency among blood donors

    DEFF Research Database (Denmark)

    Rigas, A S; Pedersen, O B; Magnussen, K

    2017-01-01

    Blood components collected from blood donors are an invaluable part of modern-day medicine. A healthy blood donor population is therefore of paramount importance. The results from the Danish Blood Donor Study (DBDS) indicate that gender, number of previous donations, time since last donation...... and menopausal status are the strongest predictors of iron deficiency. Only little information on the health effects of iron deficiency in blood donors exits. Possibly, after a standard full blood donation, a temporarily reduced physical performance for women is observed. However, iron deficiency among blood...... donors is not reflected in a reduced self-perceived mental and physical health. In general, the high proportion of iron-deficient donors can be alleviated either by extending the inter-donation intervals or by guided iron supplementation. The experience from Copenhagen, the Capital Region of Denmark...

  11. Model-Assisted Control of Flow Front in Resin Transfer Molding Based on Real-Time Estimation of Permeability/Porosity Ratio

    Directory of Open Access Journals (Sweden)

    Bai-Jian Wei

    2016-09-01

    Full Text Available Resin transfer molding (RTM is a popular manufacturing technique that produces fiber reinforced polymer (FRP composites. In this paper, a model-assisted flow front control system is developed based on real-time estimation of permeability/porosity ratio using the information acquired by a visualization system. In the proposed control system, a radial basis function (RBF network meta-model is utilized to predict the position of the future flow front by inputting the injection pressure, the current position of flow front, and the estimated ratio. By conducting optimization based on the meta-model, the value of injection pressure to be implemented at each step is obtained. Moreover, a cascade control structure is established to further improve the control performance. Experiments show that the developed system successfully enhances the performance of flow front control in RTM. Especially, the cascade structure makes the control system robust to model mismatch.

  12. PRELIMINARY METHODOLOGICAL PROPOSAL FOR ESTIMATING ENVIRONMENTAL FLOWS IN PROJECTS APPROVED BY THE MINISTRY OF ENVIRONMENT AND SUSTAINABLE DEVELOPMENT (MADS, COLOMBIA

    Directory of Open Access Journals (Sweden)

    Gabriel A. Pinilla Agudelo

    2014-01-01

    Full Text Available ABSTRACT A methodological proposal for estimating environmental flows in large projects approved by Agencia Nacional de Licencias Ambientales (ANLA in Colombian rivers was developed. The project is the result of an agreement between the MADS and the Universidad Nacional de Colombia, Bogotá (UNC. The proposed method begins with an evaluation of hydrological criteria,continues with a hydraulic and water quality validation, and follows with the determination of habitat integrity. This is an iterative process that compares conditions before and after the project construction and allows to obtain the magnitude of a monthly flow that, besides preserving the ecological functions of the river, guarantees the water uses downstream. Regarding to the biotic component, the proposal includes the establishment and monitoring of biotic integrity indices for four aquatic communities (periphyton, macroinvertebrates, riparian vegetation, and fish. The effects that flow reduction may produce in the medium and long term can be assessed by these indices. We present the results of applying the methodology to several projects licensed by the MADS. RESUMEN Se presenta una propuesta metodológica para estimar los caudales ambientales en grandes proyectos licenciados por la Agencia Nacional de Licencias Ambientales (ANLA de Colombia, resultado de un convenio interadministrativo suscrito entre el ahora Ministerio de Ambiente y Desarrollo Sostenible (MADS de Colombia y la Universidad Nacional de Colombia, Bogotá (UNC. El método propuesto parte de garantizar criterios hidrológicos, continúa con una validación hidráulica y de calidad del agua, sigue con la determinación de la integridad del hábitat, en un proceso iterativo que requiere evaluación para las condiciones antes y después de la construcción del proyecto y que permite establecer un caudal que, además de conservar las funciones ecológicas del río, garantiza los usos del recurso aguas abajo. Espec

  13. PHOSPHATE METABOLISM IN KIDNEY DONORS: A CROSS-SECTIONAL STUDY

    Directory of Open Access Journals (Sweden)

    Jayakumar Edathedathe

    2016-05-01

    Full Text Available AIM To study the changes in phosphate metabolism in kidney donors, to study the correlation of albuminuria, fractional excretion of phosphorus [FE Pi] and estimated glomerular filtration rate [eGFR] with fibroblast growth factor 23 [FGF 23] in kidney donors, to study the early tubule interstitial injury in the remnant kidney of donors by measuring urine transforming growth factor beta [TGF beta] levels. MATERIALS AND METHODS A cross-sectional study in which kidney donors with 1 year or more after donation were included. 69 kidney donors with a mean duration of 5.86 years after kidney donation were studied. Serum phosphate level, fractional excretion of phosphorus [FE Pi] and serum levels of parathyroid hormone were measured. Plasma levels of FGF 23 were measured by a second generation enzyme linked immune sorbent assay [ELISA]. Renal function was assessed by estimated glomerular filtration rate [eGFR] and degree of albuminuria. Urine levels of transforming growth factor beta [TGF beta] were measured by ELISA. A hypothesis that in kidney donors with reduced nephron number, the single nephron excretion of phosphorus will be increased to maintain normal phosphorus homeostasis and that this increase in single nephron phosphorus excretion may be mediated by FGF 23 was proposed. Testing of this hypothesis was done by studying the correlation between parameters of phosphorus metabolism, FGF 23 and the renal function of the donors. RESULTS The mean eGFR was 70.36 mL/min/1.73 m2 . 52.2% of donors had moderate increase in albuminuria [microalbuminuria], Serum phosphorus, fractional excretion of phosphorus and serum PTH levels were in the normal range. FGF 23 levels were in the normal reference range and showed no correlation with FE pi, eGFR or albuminuria, Urine TGF-beta levels were undetectable in all the donors. DISCUSSION Normal phosphorus homeostasis is maintained in kidney donors. There was no correlation between FE pi and FGF 23 levels. Kidney

  14. Laser Doppler flowmetry for bone blood flow measurement: correlation with microsphere estimates and evaluation of the effect of intracapsular pressure on femoral head blood flow

    International Nuclear Information System (INIS)

    Swiontkowski, M.F.; Tepic, S.; Perren, S.M.; Moor, R.; Ganz, R.; Rahn, B.A.

    1986-01-01

    Laser Doppler flowmetry (LDF) was used to measure bone blood flow in the rabbit femoral condyles. To correlate the LDF output signal blood cell flux to in vivo blood flow, simultaneous measurements using LDF and 85 Sr-labeled microspheres were made in an adult rabbit model. There was no correlation between the two methods for blood flow in the femoral condyles and the correlation between the two methods for blood flow in the femoral head does not achieve statistical significance. An LDF signal of 0.4 V was approximately equal to a microsphere measured flow rate of 0.4 ml blood/g bone/min. The strength of the correlation in the latter case may have been affected by (a) large arteriovenous shunts, (b) inadequate mixing of the microspheres with a left ventricular injection, and (c) insufficient numbers of microspheres present in the bone samples. When LDF was used to evaluate the effect of elevated intracapsular pressure on femoral head blood flow in skeletally mature rabbits, femoral head subchondral bone blood flow declined with increasing intracapsular pressure from a baseline value of 0.343 +/- 0.036 to a value of 0.127 +/- 0.27 at 120 cm of water pressure. The decline in femoral head blood flow was statistically significant at pressures of 40 cm of water or higher (p less than 0.001), and evaluation of sections of the proximal femora made from preterminal disulphine blue injections confirmed these findings. Intracapsular tamponade has an adverse effect on femoral head blood flow beginning well below central venous pressure and should be considered in the pathophysiology of posttraumatic and nontraumatic necrosis of the femoral head. Laser Doppler flowmetry was easy to use and appears to be a reproducible technique for evaluating femoral head blood flow, offering distinct advantages over the microsphere technique for measuring bone blood flow

  15. Estimates of Lagrangian particle transport by wave groups: forward transport by Stokes drift and backward transport by the return flow

    Science.gov (United States)

    van den Bremer, Ton S.; Taylor, Paul H.

    2014-11-01

    Although the literature has examined Stokes drift, the net Lagrangian transport by particles due to of surface gravity waves, in great detail, the motion of fluid particles transported by surface gravity wave groups has received considerably less attention. In practice nevertheless, the wave field on the open sea often has a group-like structure. The motion of particles is different, as particles at sufficient depth are transported backwards by the Eulerian return current that was first described by Longuet-Higgins & Stewart (1962) and forms an inseparable counterpart of Stokes drift for wave groups ensuring the (irrotational) mass balance holds. We use WKB theory to study the variation of the Lagrangian transport by the return current with depth distinguishing two-dimensional seas, three-dimensional seas, infinite depth and finite depth. We then provide dimensional estimates of the net horizontal Lagrangian transport by the Stokes drift on the one hand and the return flow on the other hand for realistic sea states in all four cases. Finally we propose a simple scaling relationship for the transition depth: the depth above which Lagrangian particles are transported forwards by the Stokes drift and below which such particles are transported backwards by the return current.

  16. Validation of myocardial blood flow estimation with nitrogen-13 ammonia PET by the argon inert gas technique in humans

    International Nuclear Information System (INIS)

    Kotzerke, J.; Glatting, G.; Neumaier, B.; Reske, S.N.; Hoff, J. van den; Hoeher, M.; Woehrle, J. n

    2001-01-01

    We simultaneously determined global myocardial blood flow (MBF) by the argon inert gas technique and by nitrogen-13 ammonia positron emission tomography (PET) to validate PET-derived MBF values in humans. A total of 19 patients were investigated at rest (n=19) and during adenosine-induced hyperaemia (n=16). Regional coronary artery stenoses were ruled out by angiography. The argon inert gas method uses the difference of arterial and coronary sinus argon concentrations during inhalation of a mixture of 75% argon and 25% oxygen to estimate global MBF. It can be considered as valid as the microspheres technique, which, however, cannot be applied in humans. Dynamic PET was performed after injection of 0.8±0.2 GBq 13 N-ammonia and MBF was calculated applying a two-tissue compartment model. MBF values derived from the argon method at rest and during the hyperaemic state were 1.03±0.24 ml min -1 g -1 and 2.64±1.02 ml min -1 g -1 , respectively. MBF values derived from ammonia PET at rest and during hyperaemia were 0.95±0.23 ml min -1 g -1 and 2.44±0.81 ml min -1 g -1 , respectively. The correlation between the two methods was close (y=0.92x+0.14, r=0.96; P 13 N-ammonia PET. (orig.)

  17. Modeling the radical chemistry in an oxidation flow reactor: radical formation and recycling, sensitivities, and the OH exposure estimation equation.

    Science.gov (United States)

    Li, Rui; Palm, Brett B; Ortega, Amber M; Hlywiak, James; Hu, Weiwei; Peng, Zhe; Day, Douglas A; Knote, Christoph; Brune, William H; de Gouw, Joost A; Jimenez, Jose L

    2015-05-14

    Oxidation flow reactors (OFRs) containing low-pressure mercury (Hg) lamps that emit UV light at both 185 and 254 nm ("OFR185") to generate OH radicals and O3 are used in many areas of atmospheric science and in pollution control devices. The widely used potential aerosol mass (PAM) OFR was designed for studies on the formation and oxidation of secondary organic aerosols (SOA), allowing for a wide range of oxidant exposures and short experiment duration with reduced wall loss effects. Although fundamental photochemical and kinetic data applicable to these reactors are available, the radical chemistry and its sensitivities have not been modeled in detail before; thus, experimental verification of our understanding of this chemistry has been very limited. To better understand the chemistry in the OFR185, a model has been developed to simulate the formation, recycling, and destruction of radicals and to allow the quantification of OH exposure (OHexp) in the reactor and its sensitivities. The model outputs of OHexp were evaluated against laboratory calibration experiments by estimating OHexp from trace gas removal and were shown to agree within a factor of 2. A sensitivity study was performed to characterize the dependence of the OHexp, HO2/OH ratio, and O3 and H2O2 output concentrations on reactor parameters. OHexp is strongly affected by the UV photon flux, absolute humidity, reactor residence time, and the OH reactivity (OHR) of the sampled air, and more weakly by pressure and temperature. OHexp can be strongly suppressed by high OHR, especially under low UV light conditions. A OHexp estimation equation as a function of easily measurable quantities was shown to reproduce model results within 10% (average absolute value of the relative errors) over the whole operating range of the reactor. OHexp from the estimation equation was compared with measurements in several field campaigns and shows agreement within a factor of 3. The improved understanding of the OFR185 and

  18. Usefulness of the automatic quantitative estimation tool for cerebral blood flow: clinical assessment of the application software tool AQCEL.

    Science.gov (United States)

    Momose, Mitsuhiro; Takaki, Akihiro; Matsushita, Tsuyoshi; Yanagisawa, Shin; Yano, Kesato; Miyasaka, Tadashi; Ogura, Yuka; Kadoya, Masumi

    2011-01-01

    AQCEL enables automatic reconstruction of single-photon emission computed tomogram (SPECT) without image degradation and quantitative analysis of cerebral blood flow (CBF) after the input of simple parameters. We ascertained the usefulness and quality of images obtained by the application software AQCEL in clinical practice. Twelve patients underwent brain perfusion SPECT using technetium-99m ethyl cysteinate dimer at rest and after acetazolamide (ACZ) loading. Images reconstructed using AQCEL were compared with those reconstructed using conventional filtered back projection (FBP) method for qualitative estimation. Two experienced nuclear medicine physicians interpreted the image quality using the following visual scores: 0, same; 1, slightly superior; 2, superior. For quantitative estimation, the mean CBF values of the normal hemisphere of the 12 patients using ACZ calculated by the AQCEL method were compared with those calculated by the conventional method. The CBF values of the 24 regions of the 3-dimensional stereotaxic region of interest template (3DSRT) calculated by the AQCEL method at rest and after ACZ loading were compared to those calculated by the conventional method. No significant qualitative difference was observed between the AQCEL and conventional FBP methods in the rest study. The average score by the AQCEL method was 0.25 ± 0.45 and that by the conventional method was 0.17 ± 0.39 (P = 0.34). There was a significant qualitative difference between the AQCEL and conventional methods in the ACZ loading study. The average score for AQCEL was 0.83 ± 0.58 and that for the conventional method was 0.08 ± 0.29 (P = 0.003). During quantitative estimation using ACZ, the mean CBF values of 12 patients calculated by the AQCEL method were 3-8% higher than those calculated by the conventional method. The square of the correlation coefficient between these methods was 0.995. While comparing the 24 3DSRT regions of 12 patients, the squares of the correlation

  19. Donor selection criteria and procurement

    International Nuclear Information System (INIS)

    Agcaoili, N.R.

    1999-01-01

    Donor selection is one of the most important aspects of tissue banking practice. Without a good donor selection criteria, the results of any effort of trying to preserve tissues will have disastrous outcome for the recipient of these tissues. While with a very good and strict donor selection the Tissue Bank can guarantee safe and effective tissue allografts. There are significant aspects in the history and physical examination of the donor that must be emphasized. A donor exclusion criteria has also been formulated together with a list of all the needed laboratory examinations to eliminate possible diseases that may be transferred from the donor. The methods of procurement of tissue allografts from living and cadaver donors will be described. The limitations and advantages of each will be taken.There are also special restrictions that are important in the practice of removing the tissues from the donors. All the necessary equipment should be ready and the potential risk on the personnel should be known to all doing Tissue Banking

  20. The Dirt on the Donors.

    Science.gov (United States)

    Walker, Mary Margaret

    1996-01-01

    A discussion of donor records in college and university fund-raising programs looks at a variety of issues, including who sees them (administrators, donors, volunteers, and members of the legal profession), how access to them is controlled, and what is kept in them. Suggestions are offered for managing such records, and the experiences of a number…

  1. Heart transplantation from older donors

    Directory of Open Access Journals (Sweden)

    V. N. Poptsov

    2017-01-01

    Full Text Available In the current situation of the shortage of suitable donor organs, heart transplantation from older donors is one of the ways to increase the performance of more heart transplants, particularly, in patients with urgent need of transplantation. While planning a heart transplantation from older donor one should consider increased risk of early cardiac allograft dysfunction, preexisting coronary artery disease, accelerated transplant vasculopathy which may adversely affect early and long-term survival of recipients. Subject to careful selection of donor–recipient pairs, effective prevention and treatment of early cardiac allograft dysfunction, pre-existing atherosclerosis and transplant vasculopathy the early and long-term survival of heart transplant recipients from older donors is comparable to heart transplantation from young donors.

  2. Test of the suitability of ECOPATH/ECOSIM modelling software as a compliment to estimate flows of carbon, C-14 and radionuclides in the Oeregrundsgrepen area

    Energy Technology Data Exchange (ETDEWEB)

    Sandberg, Johannes [Stockholm Univ. (Sweden). Dept. of Systems Ecology

    2004-04-01

    In this study it was evaluated whether the ECOPATH with ECOSIM software could be used as a standard platform to facilitate for radioecologists to construct and study transport and accumulation of radionuclides in aquatic food webs. The evaluation was based upon: 1) a previously published food web model of carbon/carbon-14 flow for the Oeregrundsgrepen area, Baltic Sea, 2) a generic model, 3) an ECOSIM model and 4) an ECOTRACE model. The results presented clearly shows that there is great potential for a successful development of this scientific approach in the future. The original carbon flows and assumptions was easily incorporated into the ECOPATH with ECOSIM modelling environment. The carbon flows differed only negligible between the two models, except for the benthic flows, which was more accurately described in this study. Further, by using ECOPATH it was easily discovered that the growth efficiencies used in the original model was quite high, being 47% for most of the heterotrophs, which are high from an ecological point of view. However, that is probably due to differences in how the carbon flows have been estimated in the original versus the present study. It is likely, however that the carbon demand has been underestimated in the original model. The generic model was parameterised from data available through the software as well from the diets and assumptions used in the original carbon model. The use of these parameters resulted in carbon flows, which was between 0.7 to 11 times the flows estimated by the ECOPATH model. The difference was greatest for primary producers being 3.7 to 11 times the original flows. Thus, depending on the question one is addressing it was suggested that the use of generic parameters is best for making test models of carbon and radionuclide flows in ecosystems, where the data set for validation is limited. Finally, the ECOPATH and ECOSIM model was well suited to drive a C-14 flow model, such as ECOTRACER for each of the

  3. Test of the suitability of ECOPATH/ECOSIM modelling software as a compliment to estimate flows of carbon, C-14 and radionuclides in the Oeregrundsgrepen area

    International Nuclear Information System (INIS)

    Sandberg, Johannes

    2004-04-01

    In this study it was evaluated whether the ECOPATH with ECOSIM software could be used as a standard platform to facilitate for radioecologists to construct and study transport and accumulation of radionuclides in aquatic food webs. The evaluation was based upon: 1) a previously published food web model of carbon/carbon-14 flow for the Oeregrundsgrepen area, Baltic Sea, 2) a generic model, 3) an ECOSIM model and 4) an ECOTRACE model. The results presented clearly shows that there is great potential for a successful development of this scientific approach in the future. The original carbon flows and assumptions was easily incorporated into the ECOPATH with ECOSIM modelling environment. The carbon flows differed only negligible between the two models, except for the benthic flows, which was more accurately described in this study. Further, by using ECOPATH it was easily discovered that the growth efficiencies used in the original model was quite high, being 47% for most of the heterotrophs, which are high from an ecological point of view. However, that is probably due to differences in how the carbon flows have been estimated in the original versus the present study. It is likely, however that the carbon demand has been underestimated in the original model. The generic model was parameterised from data available through the software as well from the diets and assumptions used in the original carbon model. The use of these parameters resulted in carbon flows, which was between 0.7 to 11 times the flows estimated by the ECOPATH model. The difference was greatest for primary producers being 3.7 to 11 times the original flows. Thus, depending on the question one is addressing it was suggested that the use of generic parameters is best for making test models of carbon and radionuclide flows in ecosystems, where the data set for validation is limited. Finally, the ECOPATH and ECOSIM model was well suited to drive a C-14 flow model, such as ECOTRACER for each of the

  4. Cancer Incidence and Mortality in a Cohort of US Blood Donors: A 20-Year Study

    Science.gov (United States)

    Hirschler, Nora V.; Chinn, Artina; Busch, Michael P.; Custer, Brian

    2013-01-01

    Blood donors are considered one of the healthiest populations. This study describes the epidemiology of cancer in a cohort of blood donors up to 20 years after blood donation. Records from donors who participated in the Retroviral Epidemiology Donor Study (REDS, 1991–2002) at Blood Centers of the Pacific (BCP), San Francisco, were linked to the California Cancer Registry (CCR, 1991–2010). Standardized incidence ratios (SIR) were estimated using standard US 2000 population, and survival analysis used to compare all-cause mortality among donors and a random sample of nondonors with cancer from CCR. Of 55,158 eligible allogeneic blood donors followed-up for 863,902 person-years, 4,236 (7.7%) primary malignant cancers were diagnosed. SIR in donors was 1.59 (95% CI = 1.54,1.64). Donors had significantly lower mortality (adjusted HR = 0.70, 95% CI = 0.66–0.74) compared with nondonor cancer patients, except for respiratory system cancers (adjusted HR = 0.93, 95% CI = 0.82–1.05). Elevated cancer incidence among blood donors may reflect higher diagnosis rates due to health seeking behavior and cancer screening in donors. A “healthy donor effect” on mortality following cancer diagnosis was demonstrated. This population-based database and sample repository of blood donors with long-term monitoring of cancer incidence provides the opportunity for future analyses of genetic and other biomarkers of cancer. PMID:24489545

  5. Cancer Incidence and Mortality in a Cohort of US Blood Donors: A 20-Year Study

    Directory of Open Access Journals (Sweden)

    Farnaz Vahidnia

    2013-01-01

    Full Text Available Blood donors are considered one of the healthiest populations. This study describes the epidemiology of cancer in a cohort of blood donors up to 20 years after blood donation. Records from donors who participated in the Retroviral Epidemiology Donor Study (REDS, 1991–2002 at Blood Centers of the Pacific (BCP, San Francisco, were linked to the California Cancer Registry (CCR, 1991–2010. Standardized incidence ratios (SIR were estimated using standard US 2000 population, and survival analysis used to compare all-cause mortality among donors and a random sample of nondonors with cancer from CCR. Of 55,158 eligible allogeneic blood donors followed-up for 863,902 person-years, 4,236 (7.7% primary malignant cancers were diagnosed. SIR in donors was 1.59 (95% CI = 1.54,1.64. Donors had significantly lower mortality (adjusted HR = 0.70, 95% CI = 0.66–0.74 compared with nondonor cancer patients, except for respiratory system cancers (adjusted HR = 0.93, 95% CI = 0.82–1.05. Elevated cancer incidence among blood donors may reflect higher diagnosis rates due to health seeking behavior and cancer screening in donors. A “healthy donor effect” on mortality following cancer diagnosis was demonstrated. This population-based database and sample repository of blood donors with long-term monitoring of cancer incidence provides the opportunity for future analyses of genetic and other biomarkers of cancer.

  6. A new method to estimate risk and return of non-traded assets from cash flows : The case of private equity funds

    NARCIS (Netherlands)

    Driessen, J.J.A.G.; Lin, T.C.; Phalippou, L.

    2012-01-01

    We develop a new methodology to estimate abnormal performance and risk exposure of nontraded assets from cash flows. Our methodology extends the standard internal rate of return approach to a dynamic setting. The small-sample properties are validated using a simulation study. We apply the method to

  7. A comparison of daily water use estimates derived from constant-heat sap-flow probe values and gravimetric measurements in pot-grown saplings.

    Science.gov (United States)

    K.A. McCulloh; K. Winter; F.C. Meinzer; M. Garcia; J. Aranda; Lachenbruch B.

    2007-01-01

    The use of Granier-style heat dissipation sensors to measure sap flow is common in plant physiology, ecology, and hydrology. There has been concern that any change to the original Granier design invalidates the empirical relationship between sap flux density and the temperature difference between the probes. We compared daily water use estimates from gravimetric...

  8. Estimating the arterial input function from dynamic contrast-enhanced MRI data with compensation for flow enhancement (I): Theory, method, and phantom experiments

    NARCIS (Netherlands)

    van Schie, Jeroen J. N.; Lavini, Cristina; van Vliet, Lucas J.; Vos, Frans M.

    2017-01-01

    The arterial input function (AIF) represents the time-dependent arterial contrast agent (CA) concentration that is used in pharmacokinetic modeling. To develop a novel method for estimating the AIF from dynamic contrast-enhanced (DCE-) MRI data, while compensating for flow enhancement. Signal

  9. Salivary protein concentration, flow rate, buffer capacity and pH estimation: A comparative study among young and elderly subjects, both normal and with gingivitis and periodontitis.

    Science.gov (United States)

    Shaila, Mulki; Pai, G Prakash; Shetty, Pushparaj

    2013-01-01

    To evaluate the salivary protein concentration in gingivitis and periodontitis patients and compare the parameters like salivary total protein, salivary albumin, salivary flow rate, pH, buffer capacity and flow rate in both young and elderly patients with simple methods. One hundred and twenty subjects were grouped based on their age as young and elderly. Each group was subgrouped (20 subjects) as controls, gingivitis and periodontitis. Unstimulated whole saliva was collected from patients and flow rate was noted down during collection of the sample. Salivary protein estimation was done using the Biuret method and salivary albumin was assessed using the Bromocresol green method. pH was estimated with a pHmeter and buffering capacity was analyzed with the titration method. Student's t-test, Fisher's test (ANOVA) and Tukey HSD (ANOVA) tests were used for statistical analysis. A very highly significant rise in the salivary total protein and albumin concentration was noted in gingivitis and periodontitis subjects of both young and elderly. An overall decrease in salivary flow rate was observed among the elderly, and also the salivary flow rate of women was significantly lower than that of men. Significant associations between salivary total protein and albumin in gingivitis and periodontitis were found with simple biochemical tests. A decrease in salivary flow rate among elderly and among women was noted.

  10. Methods for estimating peak-flow frequencies at ungaged sites in Montana based on data through water year 2011: Chapter F in Montana StreamStats

    Science.gov (United States)

    Sando, Roy; Sando, Steven K.; McCarthy, Peter M.; Dutton, DeAnn M.

    2016-04-05

    The U.S. Geological Survey (USGS), in cooperation with the Montana Department of Natural Resources and Conservation, completed a study to update methods for estimating peak-flow frequencies at ungaged sites in Montana based on peak-flow data at streamflow-gaging stations through water year 2011. The methods allow estimation of peak-flow frequencies (that is, peak-flow magnitudes, in cubic feet per second, associated with annual exceedance probabilities of 66.7, 50, 42.9, 20, 10, 4, 2, 1, 0.5, and 0.2 percent) at ungaged sites. The annual exceedance probabilities correspond to 1.5-, 2-, 2.33-, 5-, 10-, 25-, 50-, 100-, 200-, and 500-year recurrence intervals, respectively.Regional regression analysis is a primary focus of Chapter F of this Scientific Investigations Report, and regression equations for estimating peak-flow frequencies at ungaged sites in eight hydrologic regions in Montana are presented. The regression equations are based on analysis of peak-flow frequencies and basin characteristics at 537 streamflow-gaging stations in or near Montana and were developed using generalized least squares regression or weighted least squares regression.All of the data used in calculating basin characteristics that were included as explanatory variables in the regression equations were developed for and are available through the USGS StreamStats application (http://water.usgs.gov/osw/streamstats/) for Montana. StreamStats is a Web-based geographic information system application that was created by the USGS to provide users with access to an assortment of analytical tools that are useful for water-resource planning and management. The primary purpose of the Montana StreamStats application is to provide estimates of basin characteristics and streamflow characteristics for user-selected ungaged sites on Montana streams. The regional regression equations presented in this report chapter can be conveniently solved using the Montana StreamStats application.Selected results from

  11. Estimating the arterial input function from dynamic contrast-enhanced MRI data with compensation for flow enhancement (I): Theory, method, and phantom experiments.

    Science.gov (United States)

    van Schie, Jeroen J N; Lavini, Cristina; van Vliet, Lucas J; Vos, Frans M

    2018-05-01

    The arterial input function (AIF) represents the time-dependent arterial contrast agent (CA) concentration that is used in pharmacokinetic modeling. To develop a novel method for estimating the AIF from dynamic contrast-enhanced (DCE-) MRI data, while compensating for flow enhancement. Signal simulation and phantom measurements. Time-intensity curves (TICs) were simulated for different numbers of excitation pulses modeling flow effects. A phantom experiment was performed in which a solution (without CA) was passed through a straight tube, at constant flow velocity. Dynamic fast spoiled gradient echo (FSPGRs) at 3T MRI, both in the simulations and in the phantom experiment. TICs were generated for a duration of 373 seconds and sampled at intervals of 1.247 seconds (300 timepoints). The proposed method first estimates the number of pulses that spins have received, and then uses this knowledge to accurately estimate the CA concentration. The difference between the median of the estimated number of pulses and the true value was determined, as well as the interquartile range (IQR) of the estimations. The estimated CA concentrations were evaluated in the same way. The estimated number of pulses was also used to calculate flow velocity. The difference between the median estimated and reference number of pulses varied from -0.005 to -1.371 (corresponding IQRs: 0.853 and 48.377) at true values of 10 and 180 pulses, respectively. The difference between the median estimated CA concentration and the reference value varied from -0.00015 to 0.00306 mmol/L (corresponding IQRs: 0.01989 and 1.51013 mmol/L) at true values of 0.5 and 8.0 mmol/l, respectively, at an intermediate value of 100 pulses. The estimated flow velocities in the phantom were within 10% of the reference value. The proposed method accurately corrects the MRI signal affected by the inflow effect. 1 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2018;47:1190-1196. © 2017 International Society for Magnetic

  12. Two-dimensional magnetic field evolution measurements and plasma flow speed estimates from the coaxial thruster experiment

    International Nuclear Information System (INIS)

    Black, D.C.; Mayo, R.M.; Gerwin, R.A.; Schoenberg, K.F.; Scheuer, J.T.; Hoyt, R.P.; Henins, I.

    1994-01-01

    Local, time-dependent magnetic field measurements have been made in the Los Alamos coaxial thruster experiment (CTX) [C. W. Barnes et al., Phys. Fluids B 2, 1871 (1990); J. C. Fernandez et al., Nucl. Fusion 28, 1555 (1988)] using a 24 coil magnetic probe array (eight spatial positions, three axis probes). The CTX is a magnetized, coaxial plasma gun presently being used to investigate the viability of high pulsed power plasma thrusters for advanced electric propulsion. Previous efforts on this device have indicated that high pulsed power plasma guns are attractive candidates for advanced propulsion that employ ideal magnetohydrodynamic (MHD) plasma stream flow through self-formed magnetic nozzles. Indirect evidence of magnetic nozzle formation was obtained from plasma gun performance and measurements of directed axial velocities up to v z ∼10 7 cm/s. The purpose of this work is to make direct measurement of the time evolving magnetic field topology. The intent is to both identify that applied magnetic field distortion by the highly conductive plasma is occurring, and to provide insight into the details of discharge evolution. Data from a magnetic fluctuation probe array have been used to investigate the details of applied magnetic field deformation through the reconstruction of time-dependent flux profiles. Experimentally observed magnetic field line distortion has been compared to that predicted by a simple one-dimensional (1-D) model of the discharge channel. Such a comparison is utilized to estimate the axial plasma velocity in the thruster. Velocities determined in this manner are in approximate agreement with the predicted self-field magnetosonic speed and those measured by a time-of-flight spectrometer

  13. On the estimate of the transpiration in Mediterranean heterogeneous ecosystems with the coupled use of eddy covariance and sap flow techniques.

    Science.gov (United States)

    Corona, Roberto; Curreli, Matteo; Montaldo, Nicola; Oren, Ram

    2013-04-01

    Mediterranean ecosystems are commonly heterogeneous savanna-like ecosystems, with contrasting plant functional types (PFT) competing for the water use. Mediterranean regions suffer water scarcity due to the dry climate conditions. In semi-arid regions evapotranspiration (ET) is the leading loss term of the root-zone water budget with a yearly magnitude that may be roughly equal to the precipitation. Despite the attention these ecosystems are receiving, a general lack of knowledge persists about the estimate of ET and the relationship between ET and the plant survival strategies for the different PFTs under water stress. During the dry summers these water-limited heterogeneous ecosystems are mainly characterized by a simple dual PFT-landscapes with strong-resistant woody vegetation and bare soil since grass died. In these conditions due to the low signal of the land surface fluxes captured by the sonic anemometer and gas analyzer the widely used eddy covariance may fail and its ET estimate is not robust enough. In these conditions the use of the sap flow technique may have a key role, because theoretically it provides a direct estimate of the woody vegetation transpiration. Through the coupled use of the sap flow sensor observations, a 2D foot print model of the eddy covariance tower and high resolution satellite images for the estimate of the foot print land cover map, the eddy covariance measurements can be correctly interpreted, and ET components (bare soil evaporation and woody vegetation transpiration) can be separated. The case study is at the Orroli site in Sardinia (Italy). The site landscape is a mixture of Mediterranean patchy vegetation types: trees, including wild olives and cork oaks, different shrubs and herbaceous species. An extensive field campaign started in 2004. Land-surface fluxes and CO2 fluxes are estimated by an eddy covariance technique based micrometeorological tower. Soil moisture profiles were also continuously estimated using water

  14. Estimation of low-flow statistics at ungaged sites on streams in the Lower Hudson River Basin, New York, from data in geographic information systems

    Science.gov (United States)

    Randall, Allan D.; Freehafer, Douglas A.

    2017-08-02

    A variety of watershed properties available in 2015 from geographic information systems were tested in regression equations to estimate two commonly used statistical indices of the low flow of streams, namely the lowest flows averaged over 7 consecutive days that have a 1 in 10 and a 1 in 2 chance of not being exceeded in any given year (7-day, 10-year and 7-day, 2-year low flows). The equations were based on streamflow measurements in 51 watersheds in the Lower Hudson River Basin of New York during the years 1958–1978, when the number of streamflow measurement sites on unregulated streams was substantially greater than in subsequent years. These low-flow indices are chiefly a function of the area of surficial sand and gravel in the watershed; more precisely, 7-day, 10-year and 7-day, 2-year low flows both increase in proportion to the area of sand and gravel deposited by glacial meltwater, whereas 7-day, 2-year low flows also increase in proportion to the area of postglacial alluvium. Both low-flow statistics are also functions of mean annual runoff (a measure of net water input to the watershed from precipitation) and area of swamps and poorly drained soils in or adjacent to surficial sand and gravel (where groundwater recharge is unlikely and riparian water loss to evapotranspiration is substantial). Small but significant refinements in estimation accuracy resulted from the inclusion of two indices of stream geometry, channel slope and length, in the regression equations. Most of the regression analysis was undertaken with the ordinary least squares method, but four equations were replicated by using weighted least squares to provide a more realistic appraisal of the precision of low-flow estimates. The most accurate estimation equations tested in this study explain nearly 84 and 87 percent of the variation in 7-day, 10-year and 7-day, 2-year low flows, respectively, with standard errors of 0.032 and 0.050 cubic feet per second per square mile. The equations

  15. Anesthesia Management of Organ Donors.

    Science.gov (United States)

    Xia, Victor W; Braunfeld, Michelle

    2017-09-01

    The shortage of suitable organs is the biggest obstacle for transplants. At present, most organs for transplant in the United States are from donation after neurologic determination of death (brain death). Potential organs for transplant need to maintain their viability during a series of insults, including the original disease, physiologic derangements during the dying process, ischemia, and reperfusion. Proper donor management before, during, and after procurement has potential to increase the number and quality of organs from donors. Anesthesiologists need to understand the physiologic derangements associated with brain death and the updated donor management during the periprocurement period. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. New hydrogen donors in germanium

    International Nuclear Information System (INIS)

    Pokotilo, Yu.M.; Petukh, A.N.; Litvinov, V.V.

    2003-01-01

    The electrophysical properties of the n-type conductivity germanium, irradiated through protons, is studied by the volt-farad method. It is shown that the heat treatment of the implanted germanium at the temperature of 200-300 deg C leads to formation of the fast-diffusing second-rate donors. It is established that the diffusion coefficient of the identified donors coincides with the diffusion coefficient of the atomic hydrogen with an account of the capture on the traps. The conclusion is made, that the atomic hydrogen is the second-rate donor center in germanium [ru

  17. Can value for money be improved by changing the sequence of our donor work-up in the living kidney donor programme?

    DEFF Research Database (Denmark)

    Larsen, J.; Sorensen, S.S.; Feldt-Rasmussen, B.

    2009-01-01

    and December 2006 at our department. The cost in euro (euro) for the programme was estimated using the Danish diagnosis-related group-system (DRG). The donor work-up programme was described. One hundred and thirty-three potential donors were identified; 66 male- and 67 female subjects, median age of 52 years......The aim of the study was to identify procedures of maximum importance for acceptance or rejection of kidney donation from a living donor as well as making the process more cost-effective. We identified all potential living related donors who were examined during the period between January 2002...... was the procedure identifying most subjects who were unsuited for kidney donation. A rearrangement of the present donor work-up programme could potentially reduce the costs from euro6911 to euro5292 per donor--saving 23% of the costs. By changing the sequence of examinations, it might be possible to cut down...

  18. Individual, contextual and network characteristics of blood donors and non-donors: a systematic review of recent literature

    NARCIS (Netherlands)

    Piersma, Tjeerd W.; Bekkers, Rene; Klinkenberg, Elisabeth F.; De Kort, Wim L.A.M.; Merz, Eva-Maria

    2017-01-01

    Background The ageing population and recent migration flows may negatively affect the blood supply on the long-term, increasing the importance of targeted recruitment and retention strategies to address donors. This review sought to identify individual, network and contextual characteristics related

  19. Sizing up arthropod genomes: an evaluation of the impact of environmental variation on genome size estimates by flow cytometry and the use of qPCR as a method of estimation.

    Science.gov (United States)

    Gregory, T Ryan; Nathwani, Paula; Bonnett, Tiffany R; Huber, Dezene P W

    2013-09-01

    A study was undertaken to evaluate both a pre-existing method and a newly proposed approach for the estimation of nuclear genome sizes in arthropods. First, concerns regarding the reliability of the well-established method of flow cytometry relating to impacts of rearing conditions on genome size estimates were examined. Contrary to previous reports, a more carefully controlled test found negligible environmental effects on genome size estimates in the fly Drosophila melanogaster. Second, a more recently touted method based on quantitative real-time PCR (qPCR) was examined in terms of ease of use, efficiency, and (most importantly) accuracy using four test species: the flies Drosophila melanogaster and Musca domestica and the beetles Tribolium castaneum and Dendroctonus ponderosa. The results of this analysis demonstrated that qPCR has the tendency to produce substantially different genome size estimates from other established techniques while also being far less efficient than existing methods.

  20. Flow Cytometry Pulse Width Data Enables Rapid and Sensitive Estimation of Biomass Dry Weight in the Microalgae Chlamydomonas reinhardtii and Chlorella vulgaris

    Science.gov (United States)

    Chioccioli, Maurizio; Hankamer, Ben; Ross, Ian L.

    2014-01-01

    Dry weight biomass is an important parameter in algaculture. Direct measurement requires weighing milligram quantities of dried biomass, which is problematic for small volume systems containing few cells, such as laboratory studies and high throughput assays in microwell plates. In these cases indirect methods must be used, inducing measurement artefacts which vary in severity with the cell type and conditions employed. Here, we utilise flow cytometry pulse width data for the estimation of cell density and biomass, using Chlorella vulgaris and Chlamydomonas reinhardtii as model algae and compare it to optical density methods. Measurement of cell concentration by flow cytometry was shown to be more sensitive than optical density at 750 nm (OD750) for monitoring culture growth. However, neither cell concentration nor optical density correlates well to biomass when growth conditions vary. Compared to the growth of C. vulgaris in TAP (tris-acetate-phosphate) medium, cells grown in TAP + glucose displayed a slowed cell division rate and a 2-fold increased dry biomass accumulation compared to growth without glucose. This was accompanied by increased cellular volume. Laser scattering characteristics during flow cytometry were used to estimate cell diameters and it was shown that an empirical but nonlinear relationship could be shown between flow cytometric pulse width and dry weight biomass per cell. This relationship could be linearised by the use of hypertonic conditions (1 M NaCl) to dehydrate the cells, as shown by density gradient centrifugation. Flow cytometry for biomass estimation is easy to perform, sensitive and offers more comprehensive information than optical density measurements. In addition, periodic flow cytometry measurements can be used to calibrate OD750 measurements for both convenience and accuracy. This approach is particularly useful for small samples and where cellular characteristics, especially cell size, are expected to vary during growth. PMID

  1. Donor milk: current perspectives

    Directory of Open Access Journals (Sweden)

    Giuliani F

    2014-07-01

    Full Text Available Francesca Giuliani,1 Ilaria Rovelli,1 Chiara Peila,1 Stefania Alfonsina Liguori,2 Enrico Bertino,1 Alessandra Coscia1 1SCDU Neonatologia, Dipartimento di Scienze Pediatriche e dell'Adolescenza, Università degli Studi di Torino, Torino, Italy; 2SC Neonatologia, Ospedale Maria Vittoria, Torino, Italy Abstract: Mother's own milk is widely recognized as the optimal feeding for term infants, but increasing evidence exists of its benefits also for sick and preterm infants in neonatal intensive care units. However, the nutritional needs for appropriate growth and neurodevelopmental outcomes of such a particular population of infants should be attentively evaluated, considering also the indication to an appropriate fortification of human milk. The target is to achieve growth potential for preterm newborns while ensuring good metabolic outcomes and normal neurological development. When mother's milk is unavailable or in short supply, donor human milk (DHM represents the second best choice and, although somewhat modified by the Holder pasteurization process, it preserves many benefits when compared to formula, as documented by more and more reports, randomized controlled trials, and meta-analyses published in the past few years. Evidence exists of the protection exerted by DHM from necrotizing enterocolitis, while further studies are required to look at possible beneficial effects regarding infections, bronchopulmonary dysplasia, long-term cardiovascular risk factors, feeding tolerance, neurological outcome, and allergy. Finally, the concern that the use of DHM might decrease preterm infant breastfeeding is being raised. Conversely, publications exist showing that the use of DHM in the neonatal unit increases breastfeeding rates at discharge for infants of very low birth weight. Keywords: human milk, preterm infant feeding, milk bank, breast milk, mother's own milk, pasteurized human milk, fortification

  2. A mathematical method for verifying the validity of measured information about the flows of energy resources based on the state estimation theory

    Science.gov (United States)

    Pazderin, A. V.; Sof'in, V. V.; Samoylenko, V. O.

    2015-11-01

    Efforts aimed at improving energy efficiency in all branches of the fuel and energy complex shall be commenced with setting up a high-tech automated system for monitoring and accounting energy resources. Malfunctions and failures in the measurement and information parts of this system may distort commercial measurements of energy resources and lead to financial risks for power supplying organizations. In addition, measurement errors may be connected with intentional distortion of measurements for reducing payment for using energy resources on the consumer's side, which leads to commercial loss of energy resource. The article presents a universal mathematical method for verifying the validity of measurement information in networks for transporting energy resources, such as electricity and heat, petroleum, gas, etc., based on the state estimation theory. The energy resource transportation network is represented by a graph the nodes of which correspond to producers and consumers, and its branches stand for transportation mains (power lines, pipelines, and heat network elements). The main idea of state estimation is connected with obtaining the calculated analogs of energy resources for all available measurements. Unlike "raw" measurements, which contain inaccuracies, the calculated flows of energy resources, called estimates, will fully satisfy the suitability condition for all state equations describing the energy resource transportation network. The state equations written in terms of calculated estimates will be already free from residuals. The difference between a measurement and its calculated analog (estimate) is called in the estimation theory an estimation remainder. The obtained large values of estimation remainders are an indicator of high errors of particular energy resource measurements. By using the presented method it is possible to improve the validity of energy resource measurements, to estimate the transportation network observability, to eliminate

  3. Quantitative estimation of the influence of external vibrations on the measurement error of a coriolis mass-flow meter

    NARCIS (Netherlands)

    van de Ridder, Bert; Hakvoort, Wouter; van Dijk, Johannes; Lötters, Joost Conrad; de Boer, Andries; Dimitrovova, Z.; de Almeida, J.R.

    2013-01-01

    In this paper the quantitative influence of external vibrations on the measurement value of a Coriolis Mass-Flow Meter for low flows is investigated, with the eventual goal to reduce the influence of vibrations. Model results are compared with experimental results to improve the knowledge on how

  4. A residual-based a posteriori error estimator for single-phase Darcy flow in fractured porous media

    KAUST Repository

    Chen, Huangxin; Sun, Shuyu

    2016-01-01

    for the problem with non-intersecting fractures. The reliability and efficiency of the a posteriori error estimator are established for the error measured in an energy norm. Numerical results verifying the robustness of the proposed a posteriori error estimator

  5. Donor funding for family planning: levels and trends between 2003 and 2013.

    OpenAIRE

    Grollman, C; Cavallaro, FL; Duclos, D; Bakare, V; Martínez Álvarez, M; Borghi, J

    2018-01-01

    The International Conference on Population and Development in 1994 set targets for donor funding to support family planning programmes, and recent initiatives such as FP2020 have renewed focus on the need for adequate funding to rights-based family planning. Disbursements supporting family planning disaggregated by donor, recipient country and year are not available for recent years. We estimate international donor funding for family planning in 2003-13, the period covering the introduction o...

  6. Governance, resource curse and donor

    OpenAIRE

    Wiig, Arne

    2008-01-01

    Plan Part 1. Governance What is good governance? Why is it important? How can we measure good governance? Part 2. The resource curse and the importance of governance in resource rich countries Focus on political economy (PE) models of the resource curse Policy implications Some donor initiatives Transparency and the EITI Petroleum related aid - Window dressing initiatives or research based? Conclusion Governance, resource curse and donor

  7. Coupling habitat suitability and ecosystem health with AEHRA to estimate E-flows under intensive human activities

    Science.gov (United States)

    Zhao, C. S.; Yang, S. T.; Zhang, H. T.; Liu, C. M.; Sun, Y.; Yang, Z. Y.; Zhang, Y.; Dong, B. E.; Lim, R. P.

    2017-08-01

    Sustaining adequate environmental flows (e-flows) is a key principle for maintaining river biodiversity and ecosystem health, and for supporting sustainable water resource management in basins under intensive human activities. But few methods could correctly relate river health to e-flows assessment at the catchment scale when they are applied to rivers highly impacted by human activities. An effective method is presented in this study to closely link river health to e-flows assessment for rivers at the catchment scale. Key fish species, as indicators of ecosystem health, were selected by using the foodweb model. A multi-species-based habitat suitability model (MHSI) was improved, and coupled with dominance of the key fish species as well as the Index of Biological Integrity (IBI) to enhance its accuracy in determining the fish-preferred key hydrologic habitat variables related to ecosystem health. Taking 5964 fish samples and concurrent hydrological habitat variables as the basis, the combination of key variables of flow-velocity and water-depth were determined and used to drive the Adapted Ecological Hydraulic Radius Approach (AEHRA) to study e-flows in a Chinese urban river impacted by intensive human activities. Results showed that upstream urbanization resulted in abnormal river-course geomorphology and consequently abnormal e-flows under intensive human activities. Selection of key species based on the foodweb and trophic levels of aquatic ecosystems can reflect a comprehensive requirement on e-flows of the whole aquatic ecosystem, which greatly increases its potential to be used as a guidance tool for rehabilitation of degraded ecosystems at large spatial scales. These findings have significant ramifications for catchment e-flows assessment under intensive human activities and for river ecohealth restoration in such rivers globally.

  8. Digital subtraction angiography in 105 living renal transplant donors

    International Nuclear Information System (INIS)

    Suh, Ho Jong; Oh, Kyung Seung; Kim, So Sun; Huh, Jin Do; Kim, Ho Joon; Chun, Byung Hee; Joh, Young Duck

    1989-01-01

    In order to analyze the number and length of the renal arteries and to evaluate abnormalities of the renal parenchyma and vessel, digital subtraction angiogram images of 105 potential renal donors (45 men and 60 women aged 17-66 years) were studied retrospectively. For the entire series, 31 donors had multiple renal arteries on one side (15 on the left, 11 on the right) and 5 donors on the both sides. 89 donors were family related either parents or siblings of recipients. The estimation of the length of the renal artery was based on the mean height of the second lumbar vertebral body (L2). The right renal artery is significant longer than on the left and measured more than the height of L2 vertebral body in 84 cases on the right and 60 cases on the left. Twenty two donors underwent right nephrectomy due to presence of multiple renal arteries on the left (N=14), proximal bifurcation of left main renal artery (N=3), and young females in reproductive age (N=5). Unexpected abnormalities found with angiogram were seen in 7 cases and they include renal artery stenosis (N=2), renal cysts (N=4) and focal infarction (N=1). In cases of the renal cysts and focal infarction, there were no serious complications related to the abnormalities. It is conclude that intra-arterial digital subtraction angiography is safe and efficient method to image renal anatomy of the potential renal donors

  9. Sero prevalence of hepatitis -C antibodies in blood donors

    International Nuclear Information System (INIS)

    Rahman, M.U.; Akhtar, G.N.; Lodhi, Y.

    2002-01-01

    Objective: To assess the prevalence of anti HCV antibodies in blood donors. Design: The retrospective sero-epidemiological data of the institute of Hematology and Blood Transfusion Service, Punjab over a period of one year after starting HCV screening, was analyzed to estimate the percentage prevalence. Setting; The data was obtained regularly from the blood units established by this institute at the pablic sector hospitals and retesting on initially reactive serum sample by EIA was done at the Institute. Subjects: A total of 166183 directed first time donors or replacement blood donors aged 18-60 years who donated blood at these blood banks or at mobile sessions have been included in the study. All initially reactive donors who tested non-reactive on EIA were excluded from the study. Main outcome Measures: Assessment of prevalence of HCV in blood donors. Results: 4.45% of the total donors intially tested reactive of these 0.36 % were atsety reactive on intial screening. Further testing by EIA, 4.1%. Conclusions: The blood transfusion service started screening for HCV in April 2000 and the prevalence of HCV, amongst the transfusion transmitted infections (TTIs) being screened for in the Punjab, is the highest. It is almost double the prevalence of HBV and several thousand time that of HIV. Meticulous and total screening coverage is needed to curtail impending catastrophe. With experience, the choice of testing methodology might have to be reviewed. (author)

  10. Philanthropic Motivations of Community College Donors

    Science.gov (United States)

    Carter, Linnie S.; Duggan, Molly H.

    2011-01-01

    This descriptive study surveyed current, lapsed, and major gift donors to explore the impact of college communications on donors' decisions to contribute to the college, the likelihood of donor financial support for various college projects, and the philanthropic motivation profiles of the donors of a midsized, multicampus community college in…

  11. Kidney transplant outcomes from older deceased donors

    DEFF Research Database (Denmark)

    Pippias, Maria; Jager, Kitty J; Caskey, Fergus

    2018-01-01

    As the median age of deceased kidney donors rises, updated knowledge of transplant outcomes from older deceased donors in differing donor-recipient age groups is required. Using ERA-EDTA Registry data we determined survival outcomes of kidney allografts donated from the same older deceased donor...

  12. Estimation of Entropy Generation for Ag-MgO/Water Hybrid Nanofluid Flow through Rectangular Minichannel by Using Artificial Neural Network

    OpenAIRE

    Uysal, Cuneyt; Korkmaz, Mehmet Erdi

    2018-01-01

    The convective heat transfer andentropy generation characteristics of Ag-MgO/water hybrid nanofluid flowthrough rectangular minichannel were numerically investigated. The Reynoldsnumber was in the range of 200 to 2000 and different nanoparticle volume fractionswere varied between = 0.005 and 0.02. In addition, ArtificialNeural Network was used to create a model for estimating of entropy generationof Ag-MgO/water hybrid nanofluid flow. As a result, it was found th...

  13. Estimation of Solar Radiation, Management of Energy Flow and Development of a New Approach for the Optimisation of the Sizing of Photovoltaic System; Application to Algeria

    OpenAIRE

    Bouzid, Zakaria; Ghellai, Nassera; Benmedjahed, Miloud

    2016-01-01

    The design of photovoltaic systems is an important step, its optimization, as well as the optimization of different parameters, is a crucial operation. In our work, after estimating hourly solar radiation, we developed energy flow models for photovoltaic power based on the concept of solar usability. Then, we used a genetic algorithm to develop our own computer program (with Python) to find the best configuration (total surface of the panels, PV efficiency and total capacity of batteries) amo...

  14. Living related donor liver transplantation.

    Science.gov (United States)

    Chen, C L; Chen, Y S; Liu, P P; Chiang, Y C; Cheng, Y F; Huang, T L; Eng, H L

    1997-10-01

    Living related liver transplantation (LRLT) has been developed in response to the paediatric organ donor shortage. According to the International Living Donor Registry, 521 transplants had been performed in 515 patients between December 8 1988 and January 19 1996 in 30 centres worldwide. The overall actuarial patient and graft survival rates were 82.7 and 80%, respectively. Between June 17 1994 and November 30 1996, the authors performed 11 LRLT at the Chung Gung Memorial Hospital. The living donors consisted of 10 mothers and one father. The mean graft weight was 303 g and the mean graft recipient weight ratio was 2.2%. Donor hepatectomy was performed without vascular inflow occlusion. The intra-operative blood loss ranged from 30 mL to 120 mL with an average of 61 mL, and blood transfusion was not required in all donors both intra-operatively and during the postoperative period. Underlying diseases of the recipients were biliary atresia (n = 10) and glycogen storage disease (n = 1). The mean graft cold ischaemia time was 106 min, the mean second warm ischaemia time was 51 min and the mean interval between portal and arterial reperfusion was 81 min. The initial LRLT results were promising with all donors having been discharged without complication. The recipients experienced a few complications, all of which were manageable with early intervention. All 11 recipients are alive and well. These are encouraging results and the authors hope to expand the use of live donors for liver transplantation to cope with demand.

  15. Adverse Reactions in Allogeneic Blood Donors: A Tertiary Care Experience from a Developing Country

    Directory of Open Access Journals (Sweden)

    Sadia Sultan

    2016-03-01

    Full Text Available Objectives: Fragmented blood transfusion services along with an unmotivated blood donation culture often leads to blood shortage. Donor retention is crucial to meet the increasing blood demand, and adverse donor reactions have a negative impact on donor return. The aim of this study was to estimate adverse donor reactions and identify any demographic association.   Methods: We conducted a prospective study between January 2011 and December 2013. A total of 41,759 healthy donors were enrolled. Professionally trained donor attendants drew blood and all donors were observed during and following donation for possible adverse events for 20 minutes. Blood donors were asked to report if they suffered from any delayed adverse consequences.   Results: Out of 41,759 blood donors, 537 (1.3% experienced adverse reactions. The incidence was one in every 78 donations. The mean age of donors who experienced adverse events was 26.0±6.8 years, and all were male. Out of 537 donors, 429 (80% developed vasovagal reaction (VVR, 133 (25% had nausea, 63 (12% fainted, 35 (6% developed hyperventilation, 9 (2% had delayed syncope, and 9 (2% developed hematoma. Arterial prick, nerve injury, cardiac arrest, and seizures were not observed. Donors aged less than < 30 years and weighing < 70 kg were significantly associated with VVR, hyperventilation, and nausea (p < 0.005. Undergraduates and Urdu speaking donors also had a significant association with fainting and nausea, respectively (p < 0.05.   Conclusion: The prevalence of adverse events was low at our tertiary center. A VVR was the predominant adverse reaction and was associated with age and weight. Our study highlights the importance of these parameters in the donation process. A well-trained and experienced phlebotomist and pre-evaluation counseling of blood donors could further minimize the adverse reactions.

  16. Adverse Reactions in Allogeneic Blood Donors: A Tertiary Care Experience from a Developing Country.

    Science.gov (United States)

    Sultan, Sadia; Baig, Mohammad Amjad; Irfan, Syed Mohammed; Ahmed, Syed Ijlal; Hasan, Syeda Faiza

    2016-03-01

    Fragmented blood transfusion services along with an unmotivated blood donation culture often leads to blood shortage. Donor retention is crucial to meet the increasing blood demand, and adverse donor reactions have a negative impact on donor return. The aim of this study was to estimate adverse donor reactions and identify any demographic association.  . We conducted a prospective study between January 2011 and December 2013. A total of 41,759 healthy donors were enrolled. Professionally trained donor attendants drew blood and all donors were observed during and following donation for possible adverse events for 20 minutes. Blood donors were asked to report if they suffered from any delayed adverse consequences.  . Out of 41,759 blood donors, 537 (1.3%) experienced adverse reactions. The incidence was one in every 78 donations. The mean age of donors who experienced adverse events was 26.0±6.8 years, and all were male. Out of 537 donors, 429 (80%) developed vasovagal reaction (VVR), 133 (25%) had nausea, 63 (12%) fainted, 35 (6%) developed hyperventilation, 9 (2%) had delayed syncope, and 9 (2%) developed hematoma. Arterial prick, nerve injury, cardiac arrest, and seizures were not observed. Donors aged less than donors also had a significant association with fainting and nausea, respectively (p adverse events was low at our tertiary center. A VVR was the predominant adverse reaction and was associated with age and weight. Our study highlights the importance of these parameters in the donation process. A well-trained and experienced phlebotomist and pre-evaluation counseling of blood donors could further minimize the adverse reactions.

  17. Estimation of unsaturated zone traveltimes for Rainier Mesa and Shoshone Mountain, Nevada Test Site, Nevada, using a source-responsive preferential-flow model

    Energy Technology Data Exchange (ETDEWEB)

    Brian A. Ebel; John R. Nimmo

    2009-09-11

    unsaturated zone takes place as preferential flow, faster than would be predicted by the coupled Richards' and advection-dispersion equations with hydraulic properties estimated by traditional means. At present the hydrologic community has not achieved consensus as to whether a modification of Richards' equation, or a fundamentally different formulation, would best quantify preferential flow. Where the fastest contaminant transport speed is what needs to be estimated, there is the possibility of simplification of the evaluation process. One way of doing so is by a two-step process in which the first step is to evaluate whether significant preferential flow and solute transport is possible for the media and conditions of concern. The second step is to carry out (a) a basic Richards' and advection-dispersion equation analysis if it is concluded that preferential flow is not possible or (b) an analysis that considers only the fastest possible preferential-flow processes, if preferential flow is possible. For the preferential-flow situation, a recently published model describable as a Source-Responsive Preferential-Flow (SRPF) model is an easily applied option. This report documents the application of this two-step process to flow through the thick unsaturated zones of Rainier Mesa and Shoshone Mountain in the Nevada Test Site. Application of the SRPF model involves distinguishing between continuous and intermittent water supply to preferential flow paths. At Rainier Mesa and Shoshone Mountain this issue is complicated by the fact that contaminant travel begins at a location deep in the subsurface, where there may be perched water that may or may not act like a continuous supply, depending on such features as the connectedness of fractures and the nature of impeding layers. We have treated this situation by hypothesizing both continuous and intermittent scenarios for contaminant transport to the carbonate aquifer and reporting estimation of the fastest speed for

  18. Estimation of Unsaturated Zone Traveltimes for Rainier Mesa and Shoshone Mountain, Nevada Test Site, Nevada, Using a Source-Responsive Preferential-Flow Model

    Science.gov (United States)

    Ebel, Brian A.; Nimmo, John R.

    2009-01-01

    zone takes place as preferential flow, faster than would be predicted by the coupled Richards' and advection-dispersion equations with hydraulic properties estimated by traditional means. At present the hydrologic community has not achieved consensus as to whether a modification of Richards' equation, or a fundamentally different formulation, would best quantify preferential flow. Where the fastest contaminant transport speed is what needs to be estimated, there is the possibility of simplification of the evaluation process. One way of doing so is by a two-step process in which the first step is to evaluate whether significant preferential flow and solute transport is possible for the media and conditions of concern. The second step is to carry out (a) a basic Richards' and advection-dispersion equation analysis if it is concluded that preferential flow is not possible or (b) an analysis that considers only the fastest possible preferential-flow processes, if preferential flow is possible. For the preferential-flow situation, a recently published model describable as a Source-Responsive Preferential-Flow (SRPF) model is an easily applied option. This report documents the application of this two-step process to flow through the thick unsaturated zones of Rainier Mesa and Shoshone Mountain in the Nevada Test Site. Application of the SRPF model involves distinguishing between continuous and intermittent water supply to preferential flow paths. At Rainier Mesa and Shoshone Mountain this issue is complicated by the fact that contaminant travel begins at a location deep in the subsurface, where there may be perched water that may or may not act like a continuous supply, depending on such features as the connectedness of fractures and the nature of impeding layers. We have treated this situation by hypothesizing both continuous and intermittent scenarios for contaminant transport to the carbonate aquifer and reporting estimation of the fastest speed for both of th

  19. [Lack of donor organs as an argument for living donors?].

    Science.gov (United States)

    Kirste, G

    2010-09-01

    In Germany more than 12,000 patients are presently waiting for an organ donation. Living donation makes sense for the long waiting time for a kidney, but it is not a permanent solution for the lack of organ donations. In the future topics which should be discussed are intensified public relations, a better family care and the allocation of rights and duties at the German coordinating agency. For all the prospects of success after a living donation the high standards of quality and security, which are targeted by the German donor organization in recipient protection, responsible evaluation of the expanded donor criteria and immunosuppressive therapy are all in favor of post-mortem organ donation. For all the phenomenal chance of success the priority of the post-mortem organ donation is regulated by law. The living donation remains an individual decision of the donor and the personal situation of life.

  20. Estimation of left ventricular blood flow parameters: clinical application of patient-specific CFD simulations from 4D echocardiography

    Science.gov (United States)

    Larsson, David; Spühler, Jeannette H.; Günyeli, Elif; Weinkauf, Tino; Hoffman, Johan; Colarieti-Tosti, Massimiliano; Winter, Reidar; Larsson, Matilda

    2017-03-01

    Echocardiography is the most commonly used image modality in cardiology, assessing several aspects of cardiac viability. The importance of cardiac hemodynamics and 4D blood flow motion has recently been highlighted, however such assessment is still difficult using routine echo-imaging. Instead, combining imaging with computational fluid dynamics (CFD)-simulations has proven valuable, but only a few models have been applied clinically. In the following, patient-specific CFD-simulations from transthoracic dobutamin stress echocardiography have been used to analyze the left ventricular 4D blood flow in three subjects: two with normal and one with reduced left ventricular function. At each stress level, 4D-images were acquired using a GE Vivid E9 (4VD, 1.7MHz/3.3MHz) and velocity fields simulated using a presented pathway involving endocardial segmentation, valve position identification, and solution of the incompressible Navier-Stokes equation. Flow components defined as direct flow, delayed ejection flow, retained inflow, and residual volume were calculated by particle tracing using 4th-order Runge-Kutta integration. Additionally, systolic and diastolic average velocity fields were generated. Results indicated no major changes in average velocity fields for any of the subjects. For the two subjects with normal left ventricular function, increased direct flow, decreased delayed ejection flow, constant retained inflow, and a considerable drop in residual volume was seen at increasing stress. Contrary, for the subject with reduced left ventricular function, the delayed ejection flow increased whilst the retained inflow decreased at increasing stress levels. This feasibility study represents one of the first clinical applications of an echo-based patient-specific CFD-model at elevated stress levels, and highlights the potential of using echo-based models to capture highly transient flow events, as well as the ability of using simulation tools to study clinically complex

  1. Why Should Donors Care about Corruption?

    OpenAIRE

    Kolstad, Ivar

    2008-01-01

    Corruption is bad for donor business. Corruption reduces popular support for aid in donor countries. However, aid agencies should pay attention to corruption because it is the right thing to do, rather than just the smart thing to do. Donor anti-corruption policies require a strong grounding in ethics. Corruption produces bad development outcomes. This is the reasoning largely underlying donor anti-corruption efforts. The focus on consequences of corruption makes donor anticorruptioneffo...

  2. Unrelated Hematopoietic Stem Cell Donor Matching Probability and Search Algorithm

    Directory of Open Access Journals (Sweden)

    J.-M. Tiercy

    2012-01-01

    Full Text Available In transplantation of hematopoietic stem cells (HSCs from unrelated donors a high HLA compatibility level decreases the risk of acute graft-versus-host disease and mortality. The diversity of the HLA system at the allelic and haplotypic level and the heterogeneity of HLA typing data of the registered donors render the search process a complex task. This paper summarizes our experience with a search algorithm that includes at the start of the search a probability estimate (high/intermediate/low to identify a HLA-A, B, C, DRB1, DQB1-compatible donor (a 10/10 match. Based on 2002–2011 searches about 30% of patients have a high, 30% an intermediate, and 40% a low probability search. Search success rate and duration are presented and discussed in light of the experience of other centers. Overall a 9-10/10 matched HSC donor can now be identified for 60–80% of patients of European descent. For high probability searches donors can be selected on the basis of DPB1-matching with an estimated success rate of >40%. For low probability searches there is no consensus on which HLA incompatibilities are more permissive, although HLA-DQB1 mismatches are generally considered as acceptable. Models for the discrimination of more detrimental mismatches based on specific amino acid residues rather than specific HLA alleles are presented.

  3. Function following Living Donor Nephrectomy

    Directory of Open Access Journals (Sweden)

    Jonathan Heldt

    2011-01-01

    Full Text Available Background. While tobacco use by a renal transplant recipient has been shown to negatively affect graft and patient survival, the effect of smoking on the part of the kidney donor remains unknown. Methods. 29 smoking donors (SD and their recipients (SD-R as well as 71 non-smoking donors (ND and their recipients (ND-R were retrospectively reviewed. Preoperative demographics and perioperative variables including serum creatinine (Cr and glomerular filtration rate (GFR were calculated and stratified by amount of tobacco exposure in pack-years. Clinical outcomes were analyzed with a Student's t-test, chi-square, and multiple linear regression analysis (=0.05. Results. At most recent followup, SD-R's had a significantly smaller percent decrease in postoperative Cr than ND-R's (−57% versus −81%; =0.015 and lower calculated GFR's (37.0 versus 53.0 mL/min per 1.73 m2; <0.001. SD's had a larger percent increase in Cr than ND's at most recent followup (57% versus 40%; <0.001, with active smokers having a larger increase than those who quit, although this difference was not statistically significant (68% versus 52%; =0.055. Conclusions. Use of tobacco by kidney donors is associated with decreased posttransplant renal function, although smoking cessation can improve outcomes. Kidneys from donors who smoke should be used with caution.

  4. Dengue antibodies in blood donors.

    Science.gov (United States)

    Ribas-Silva, Rejane Cristina; Eid, Andressa Ahmad

    2012-01-01

    Dengue is an urban arbovirus whose etiologic agent is a virus of the genus Flavorius with four distinct antigen serotypes (DENV-1, DENV-2, DENV-3 and DENV-4) that is transmitted to humans through the bite of the mosquito Aedes aegypti. The Campo Mourão region in Brazil is endemic for dengue fever. OBTECTIVE: The aim of this study was to evaluate the presence of IgG and IgM antibodies specific to the four serotypes of dengue in donors of the blood donor service in the city of Campo Mourão. Epidemiological records were evaluated and 4 mL of peripheral blood from 213 blood donors were collected in tubes without anticoagulant. Serum was then obtained and immunochromatographic tests were undertaken (Imuno-Rápido Dengue IgM/IgG(TM)). Individuals involved in the study answered a social and epidemiological questionnaire on data which included age, gender and diagnosis of dengue. Only three (1.4%) of the 213 blood tests were positive for IgG anti-dengue antibodies. No donors with IgM antibody, which identifies acute infection, were identified. The results of the current analysis show that the introduction of quantitative or molecular serological methods to determine the presence of anti-dengue antibodies or the detection of the dengue virus in blood donors in endemic regions should be established so that the quality of blood transfusions is guaranteed.

  5. What Drives Donor Funding in Population Assistance Programs?

    NARCIS (Netherlands)

    H.P. van Dalen (Hendrik); M. Reuser

    2005-01-01

    textabstractThe 1994 International Conference of Population and Development (ICPD) established goals for the expansion of population assistance. This global effort has so far not sufficiently been supported by donor funds. Dynamic panel estimation methods are used to see what lies behind the sharing

  6. Random walk-percolation-based modeling of two-phase flow in porous media: Breakthrough time and net to gross ratio estimation

    Science.gov (United States)

    Ganjeh-Ghazvini, Mostafa; Masihi, Mohsen; Ghaedi, Mojtaba

    2014-07-01

    Fluid flow modeling in porous media has many applications in waste treatment, hydrology and petroleum engineering. In any geological model, flow behavior is controlled by multiple properties. These properties must be known in advance of common flow simulations. When uncertainties are present, deterministic modeling often produces poor results. Percolation and Random Walk (RW) methods have recently been used in flow modeling. Their stochastic basis is useful in dealing with uncertainty problems. They are also useful in finding the relationship between porous media descriptions and flow behavior. This paper employs a simple methodology based on random walk and percolation techniques. The method is applied to a well-defined model reservoir in which the breakthrough time distributions are estimated. The results of this method and the conventional simulation are then compared. The effect of the net to gross ratio on the breakthrough time distribution is studied in terms of Shannon entropy. Use of the entropy plot allows one to assign the appropriate net to gross ratio to any porous medium.

  7. Donor Outcomes in Living Donor Liver Transplantation-Analysis of 275 Donors From a Single Centre in India.

    Science.gov (United States)

    Narasimhan, Gomathy; Safwan, Mohamed; Kota, Venugopal; Reddy, Mettu S; Bharathan, Anand; Dabora, Abderrhaim; Kaliamoorthy, Ilankumaran; Kanagavelu, Rathnavel G; Srinivasan, Vijaya; Rela, Mohamed

    2016-06-01

    Live donor liver transplantation is the predominant form of liver transplantation in India and in most Asian countries. Donor outcome reports are an important source of information to be shared with prospective donors at the time of informed consent. This is the first donor outcome series from India. Analysis of donor characteristics and morbidity of 275 live donors from a single large volume center is documented. Two hundred seventy-five patients donated from November 2009 to October 2014, 144 were women and 131 were men, 180 donated to adults and 95 donated to children. Right lobe donors were majority at 62.2% followed by left lateral segment 28%. Two thirds of the live donors did not have any morbidity; 114 complications were encountered in 85 patients. The complications were graded as per Clavien 5 tier grading and major morbidity (grade III b, grade IV grade V) was 4.36%. Postoperative biliary complication was seen in 3 donors. This large single-center study is the first donor outcome report from India, and the results are comparable to other published donor series. Documentation and regular audit of donor outcomes is important to help improve the safety of donor hepatectomy and to provide a database for informed consent of prospective donors.

  8. Exchange donor transplantation: ethical option for living renal transplantation.

    Science.gov (United States)

    Gürkan, A; Kaçar, S; Varılsuha, C; Tilif, S; Turunç, V; Doǧan, M; Dheir, H; Sahin, S

    2011-04-01

    Taking in consideration the opinion of our team, which necessitates obligation of a relative relation between donors and recipients (genetic or matrimonial), we performed donor exchanges as an ethical alternative in living donor transplantations. We reviewed the outcomes of our exchange series. Between July 2003 and August 2010 we performed 110 exchange donor transplantations in four hospitals: one four-way, two three-way, and 100 two-way cases. Donors were mostly spouses (n = 71) or mothers (n = 15). The mean age of the donors was 48.8 (range = 23-69) and the recipients 41.4 years (range = 5-66). Two were transplanted preemptively and the others had a mean dialysis duration of 43 months (range = 1-120). Among 110 patients, three compatible pairs joined the group voluntarily; 71, due to ABO incompatibility and 36, due to crossmatch positivity. Induction therapy was used in 92 patients. HLA mismatches (MM) were: one MM in three; two MM in three; three MM in 18, four MM in 36; five MM in 34; and six MM in 18. Among 90 patients tested for panel-reactive antibodies PRA, five showed class I and 10, class II positivity. In 11 patients, B-cell positivity was detected by flow cytometry. Delayed graft function (n = 2), acute rejection (n = 11), BK virus infection (n = 1), and cytomegalovirus infection (n = 3) were seen postoperatively. Three (2.7%) patients died due to sepsis. Five patients returned to dialysis program due to interstitial fibrosis tubular atrophy (IFTA) (n = 2), renal vein thrombosis (n = 1), de novo glomerulopathy (n = 1), or primary nonfunction (n = 1). The 1- and 5-year patient and graft survival rates were 96% and 96%, 95% and 89%, respectively. We believe that exchange donor transplantation is as successful as direct transplants; it is a good, ethical alternative to unrelated living transplantations. Copyright © 2011 Elsevier Inc. All rights reserved.

  9. The use of a diffuse interface model to estimate effective transport properties for two-phase flows in porous media

    International Nuclear Information System (INIS)

    Fichot, Floriana; Duval, Fabiena; Garcia, Aureliena; Belloni, Julien; Quintard, Michel

    2005-01-01

    Full text of publication follows: In the framework of its research programme on severe nuclear reactor accidents, IRSN investigates the water flooding of an overheated porous bed, where complex two-phase flows are likely to exist. The goal is to describe the flow with a general model, covering rods and debris beds regions in the vessel. A better understanding of the flow at the pore level appears to be necessary in order to justify and improve closure laws of macroscopic models. Although the Direct Numerical Simulation (DNS) of two-phase flows is possible with several methods, applications are now limited to small computational domains, typically of the order of a few centimeters. Therefore, numerical solutions at the reactor scale can only be obtained by using averaged models. Volume averaging is the most traditional way of deriving such models. For nuclear safety codes, a control volume must include a few rods or a few debris particles, with a characteristic dimension of a few centimeters. The difficulty usually met with averaged models is the closure of several transport or source terms which appear in the averaged conservation equations (for example the interfacial drag or the heat transfers between phases) [2]. In the past, the closure of these terms was obtained, when possible, from one-dimensional experiments that allowed measurements of heat flux or pressure drops. For more complex flows, the experimental measurement of local parameters is often impossible and the effective properties cannot be determined easily. An alternative way is to perform 'numerical experiments' with numerical simulations of the local flow. As mentioned above, the domain of application of DNS corresponds to the size of control volumes necessary to derive averaged models. Therefore DNS appears as a powerful tool to investigate the local features of a two-phase flow in complex geometries. Diffuse interface methods provide a way to model flows with interfacial phenomena through an

  10. An inverse modeling approach to estimate groundwater flow and transport model parameters at a research site at Vandenberg AFB, CA

    Science.gov (United States)

    Rasa, E.; Foglia, L.; Mackay, D. M.; Ginn, T. R.; Scow, K. M.

    2009-12-01

    A numerical groundwater fate and transport model was developed for analyses of data from field experiments evaluating the impacts of ethanol on the natural attenuation of benzene, toluene, ethylbenzene, and xylenes (BTEX) and methyl tert-butyl ether (MTBE) at Vandenberg Air Force Base, Site 60. We used the U.S. Geological Survey (USGS) groundwater flow (MODFLOW2000) and transport (MT3DMS) models in conjunction with the USGS universal inverse modeling code (UCODE) to jointly determine flow and transport parameters using bromide tracer data from multiple experiments in the same location. The key flow and transport parameters include hydraulic conductivity of aquifer and aquitard layers, porosity, and transverse and longitudinal dispersivity. Aquifer and aquitard layers were assumed homogenous in this study. Therefore, the calibration parameters were not spatially variable within each layer. A total of 162 monitoring wells in seven transects perpendicular to the mean flow direction were monitored over the course of ten months, resulting in 1,766 bromide concentration data points and 149 head values used as observations for the inverse modeling. The results showed the significance of the concentration observation data in predicting the flow model parameters and indicated the sensitivity of the hydraulic conductivity of different zones in the aquifer including the excavated former contaminant zone. The model has already been used to evaluate alternative designs for further experiments on in situ bioremediation of the tert-butyl alcohol (TBA) plume remaining at the site. We describe the recent applications of the model and future work, including adding reaction submodels to the calibrated flow model.

  11. The impact of highway base-saturation flow rate adjustment on Kuwait's transport and environmental parameters estimation.

    Science.gov (United States)

    AlRukaibi, Fahad; AlKheder, Sharaf; Al-Rukaibi, Duaij; Al-Burait, Abdul-Aziz

    2018-03-23

    Traditional transportation systems' management and operation mainly focused on improving traffic mobility and safety without imposing any environmental concerns. Transportation and environmental issues are interrelated and affected by the same parameters especially at signalized intersections. Additionally, traffic congestion at signalized intersections has a major contribution in the environmental problem as related to vehicle emission, fuel consumption, and delay. Therefore, signalized intersections' design and operation is an important parameter to minimize the impact on the environment. The design and operation of signalized intersections are highly dependent on the base saturation flow rate (BSFR). Highway Capacity Manual (HCM) uses a base-saturation flow rate of 1900-passenger car/h/lane for areas with a population intensity greater than or equal to 250,000 and a value of 1750-passenger car/h/lane for less populated areas. The base-saturation flow rate value in HCM is derived from a field data collected in developed countries. The adopted value in Kuwait is 1800passengercar/h/lane, which is the value that used in this analysis as a basis for comparison. Due to the difference in behavior between drivers in developed countries and their fellows in Kuwait, an adjustment was made to the base-saturation flow rate to represent Kuwait's traffic and environmental conditions. The reduction in fuel consumption and vehicles' emission after modifying the base-saturation flow rate (BSFR increased by 12.45%) was about 34% on average. Direct field measurements of the saturation flow rate were used while using the air quality mobile lab to calculate emissions' rates. Copyright © 2018 Elsevier B.V. All rights reserved.

  12. Gamete donation: parents' experiences of searching for their child's donor siblings and donor.

    Science.gov (United States)

    Freeman, T; Jadva, V; Kramer, W; Golombok, S

    2009-03-01

    This study investigates the new phenomenon of parents of donor offspring searching for and contacting their child's 'donor siblings' (i.e. donor offspring conceived by the same donor) and donor. Online questionnaires were completed by 791 parents (39% lone-mother, 35% lesbian-couple, 21% heterosexual-couple, 5% non-specified) recruited via the Donor Sibling Registry; a US-based international registry that facilitates contact between donor conception families who share the same donor. Data were collected on parents' reasons for searching for their child's donor siblings and/or donor, the outcome of these searches and parents' and their child's experiences of any resulting contact. Parents' principal motivation for searching for their child's donor siblings was curiosity and for their donor, enhancing their child's sense of identity. Some parents had discovered large numbers of donor siblings (maximum = 55). Most parents reported positive experiences of contacting and meeting their child's donor siblings and donor. This study highlights that having access to information about a child's donor origins is important for some parents and has potentially positive consequences. These findings have wider implications because the removal of donor anonymity in the UK and elsewhere means that increasing numbers of donor offspring are likely to seek contact with their donor relations in the future.

  13. Comparing the Performance of Artificial Intelligence Models in Estimating Water Quality Parameters in Periods of Low and High Water Flow

    Directory of Open Access Journals (Sweden)

    majid montaseri

    2017-03-01

    Full Text Available Introduction: A total dissolved solid (TDS is an important indicator for water quality assesment. Since the composition of mineral salts and discharge affects the TDS of water, it is important to understand the relationships of mineral salts composition with TDS. Materials and Methods: In this study, methods of artificial neural networks with five different training algorithm,Levenberg-Marquardt (LM, Scaled Conjugate Gradient (SCG, Fletcher Conjugate Gradient (CGF, One Step Secant (OSS and Gradient descent with adaptive learning rate backpropagation(GDAalgorithm and adaptive Neurofuzzy inference system based on Subtractive Clustering were used to model water quality properties of Zarrineh River Basin, to be developed in total dissolved solids prediction. ANN and ANFIS program code were written in MATLAB language. Here, the ANN with one hidden layer was used and the hidden nodes’ number was determined using trial and error. Different activation functions (logarithm sigmoid, tangent sigmoid and linear were tried for the hidden and output nodes. Therefore, water quality data from seven hydrometer stationswere used during the statistical period of 18years (1993-2010.In this research, the study period was divided into two periods of dry and wet flow, and then in a preliminary statistical analysis, the main parameters affecting the estimation of the TDS are determined and isused for modeling. 75% of data are used for remaining and 25% of the data are used for evaluation of the model, randomly. In this paper, three statistical evaluation criteria, correlation coefficient (R, the root mean square error (RMSE and mean absolute error (MAE were used to assess models’ performances. Results and Discussion: By applying correlation coefficients method between the parameters of water quality and discharge with total dissolved solid in two periods, wet and dry periods, the significant (at 95% level variables entered into the model were Q, HCO3., Cl, So4, Ca

  14. Risk of cancer after blood transfusion from donors with subclinical cancer: a retrospective cohort study

    DEFF Research Database (Denmark)

    Edgren, Gustaf; Hjalgrim, Henrik; Reilly, Marie

    2007-01-01

    transmission from blood donors to recipients through blood transfusion. METHODS: We did a register-based retrospective cohort study of cancer incidence among patients who received blood from donors deemed to have a subclinical cancer at the time of donation. These precancerous donors were diagnosed......, and essentially complete, population and health-care registers. The risk of cancer in exposed recipients relative to that in recipients who received blood from non-cancerous donors was estimated with multivariate Poisson regression, adjusting for potential confounding factors. FINDINGS: Of the 354 094 transfusion...... recipients eligible for this analysis, 12,012 (3%) were exposed to blood products from precancerous donors. There was no excess risk of cancer overall (adjusted relative risk 1.00, 95% CI 0.94-1.07) or in crude anatomical subsites among recipients of blood from precancerous donors compared with recipients...

  15. Input Selection for Return Temperature Estimation in Mixing Loops using Partial Mutual Information with Flow Variable Delay

    DEFF Research Database (Denmark)

    Overgaard, Anders; Kallesøe, Carsten Skovmose; Bendtsen, Jan Dimon

    2017-01-01

    adgang til data, er ønsker at skabe en datadreven model til kontrol. Grundet den store mængde tilgængelig data anvendes der en metode til valg af inputs kaldet "Partial Mutual Information" (PMI). Denne artikel introducerer en metode til at inkluderer flow variable forsinkelser i PMI. Data fra en...... kontorbygning i Bjerringbro anvendes til analyse. Det vises at "Mutual Information" og et "Generalized Regression Neural Network" begge forbedres ved at anvende flow variabelt forsinkelse i forhold til at anvende konstante delay....

  16. Estimation of myocardial flow reserve utilizing an ultrafast cardiac SPECT: Comparison with coronary angiography, fractional flow reserve, and the SYNTAX score.

    Science.gov (United States)

    Miyagawa, Masao; Nishiyama, Yoshiko; Uetani, Teruyoshi; Ogimoto, Akiyoshi; Ikeda, Shuntaro; Ishimura, Hayato; Watanabe, Emiri; Tashiro, Rami; Tanabe, Yuki; Kido, Teruhito; Kurata, Akira; Mochizuki, Teruhito

    2017-10-01

    Quantitative assessment of myocardial flow reserve (MFR) by single photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) is challenging but may facilitate evaluation of multi-vessel coronary artery disease (CAD). We enrolled 153 patients with suspected or known CAD, referred for pharmacological stress MPI. They underwent a 99m Tc-perfusion stress/rest SPECT with an ultrafast cadmium-zinc-telluride (CZT) camera. Dynamic data were acquired and time-activity curves fitted to a 1-tissue compartment analysis with input function. K1 was assigned for stress and rest data. The MFR index (MFRi) was calculated as K1 stress/K1 at-rest. The findings were validated by invasive coronary angiography in 69 consecutive patients. The global MFRi was 1.46 (1.16-1.76), 1.33 (1.12-1.54), and 1.18 (1.01-1.35), for 1-vessel disease (VD), 2-VD, and 3-VD, respectively. In the 3-VD, global MFRi was lower than that in 0-VD (1.63 [1.22-2.04], Pfraction (OR: 61.6 [57.5-66.0]), and global MFRi (OR: 119.6 [111.5-127.7], P=0.002). A cut-off value of 1.3 yielded 93.3% sensitivity and 75.9% specificity for diagnosing 3-VD. Fractional flow reserve positively correlated with regional MFRi (r=0.62, P=0.008), and the SYNTAX score correlated negatively with global MFRi (r=0.567, P=0.0003). We developed and validated a clinically available method for MFR quantification by dynamic 99m Tc-perfusion SPECT utilizing a CZT camera, which improves the detectability of multi-vessel CAD. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Achieving donor management goals before deceased donor procurement is associated with more organs transplanted per donor.

    Science.gov (United States)

    Malinoski, Darren J; Daly, Michael C; Patel, Madhukar S; Oley-Graybill, Chrystal; Foster, Clarence E; Salim, Ali

    2011-10-01

    There is a national shortage of organs available for transplantation. Implementation of preset donor management goals (DMGs) to improve outcomes is recommended, but uniform practices and data are lacking. We hypothesized that meeting DMGs before organ procurement would result in more organs transplanted per donor (OTPD). The eight organ procurement organization in United Network for Organ Sharing Region 5 selected 10 critical care end points as DMGs. Each organ procurement organization submitted retrospective data from 40 standard criteria donors. "DMGs met" was defined as achieving any eight DMGs before procurement. The primary outcome was ≥4 OTPD. Binary logistic regression was used to determine independent predictors of ≥4 OTPD with a pdonors had 3.6±1.6 OTPD. Donors with DMGs met had more OTPD (4.4 vs. 3.3, p50% (OR=4.0), Pao2:FIO2>300 (OR=4.6), and serum sodium 135 to 160 mEq/L (OR=3.4). Meeting DMGs before procurement resulted in more OTPD. Donor factors and critical care end points are independent predictors of organ yield. Prospective studies are needed to determine the true impact of each DMG on the number and function of transplanted organs.

  18. Bone density in apheresis donors and whole blood donors

    NARCIS (Netherlands)

    Boot, C.L.; Luken, J.S.; van den Burg, P.J.M.; de Kort, W.L.A.M.; Koopman, M.M.W.; Vrielink, H.; van Schoor, N.M.; den Heijer, M.; Lips, P.

    2015-01-01

    Apheresis donation using citrate causes acute decrease in serum calcium and increase in serum parathyroid hormone. Long-term consequences, such as decrease in bone mineral density (BMD), are not known. In this study, we compared the BMD of 20 postmenopausal apheresis donors (mean donation number 115

  19. Suicidal hanging donors for lung transplantation

    Science.gov (United States)

    Ananiadou, Olga; Schmack, Bastian; Zych, Bartlomiej; Sabashnikov, Anton; Garcia-Saez, Diana; Mohite, Prashant; Weymann, Alexander; Mansur, Ashham; Zeriouh, Mohamed; Marczin, Nandor; De Robertis, Fabio; Simon, Andre Rüdiger; Popov, Aron-Frederik

    2018-01-01

    Abstract In the context of limited donor pool in cardiothoracic transplantation, utilization of organs from high risk donors, such as suicidal hanging donors, while ensuring safety, is under consideration. We sought to evaluate the outcomes of lung transplantations (LTx) that use organs from this group. Between January 2011 and December 2015, 265 LTx were performed at our center. Twenty-two recipients received lungs from donors after suicidal hanging (group 1). The remaining 243 transplantations were used as a control (group 2). Analysis of recipient and donor characteristics as well as outcomes was performed. No statistically significant difference was found in the donor characteristics between analyzed groups, except for higher incidence of cardiac arrest, younger age and smoking history of hanging donors (P donor cause of death is not associated with poor mid-term survival or chronic lung allograft dysfunction following transplantation. These results encourage assessment of lungs from hanging donors, and their consideration for transplantation. PMID:29620623

  20. A statistical method for estimating wood thermal diffusivity and probe geometry using in situ heat response curves from sap flow measurements.

    Science.gov (United States)

    Chen, Xingyuan; Miller, Gretchen R; Rubin, Yoram; Baldocchi, Dennis D

    2012-12-01

    The heat pulse method is widely used to measure water flux through plants; it works by using the speed at which a heat pulse is propagated through the system to infer the velocity of water through a porous medium. No systematic, non-destructive calibration procedure exists to determine the site-specific parameters necessary for calculating sap velocity, e.g., wood thermal diffusivity and probe spacing. Such parameter calibration is crucial to obtain the correct transpiration flux density from the sap flow measurements at the plant scale and subsequently to upscale tree-level water fluxes to canopy and landscape scales. The purpose of this study is to present a statistical framework for sampling and simultaneously estimating the tree's thermal diffusivity and probe spacing from in situ heat response curves collected by the implanted probes of a heat ratio measurement device. Conditioned on the time traces of wood temperature following a heat pulse, the parameters are inferred using a Bayesian inversion technique, based on the Markov chain Monte Carlo sampling method. The primary advantage of the proposed methodology is that it does not require knowledge of probe spacing or any further intrusive sampling of sapwood. The Bayesian framework also enables direct quantification of uncertainty in estimated sap flow velocity. Experiments using synthetic data show that repeated tests using the same apparatus are essential for obtaining reliable and accurate solutions. When applied to field conditions, these tests can be obtained in different seasons and can be automated using the existing data logging system. Empirical factors are introduced to account for the influence of non-ideal probe geometry on the estimation of heat pulse velocity, and are estimated in this study as well. The proposed methodology may be tested for its applicability to realistic field conditions, with an ultimate goal of calibrating heat ratio sap flow systems in practical applications.

  1. Thermal-dissipation sap flow sensors may not yield consistent sap-flux estimates over multiple years

    Science.gov (United States)

    Georgianne W. Moore; Barbara J. Bond; Julia A. Jones; Frederick C. Meinzer

    2010-01-01

    Sap flow techniques, such as thermal dissipation, involve an empirically derived relationship between sap flux and the temperature differential between a heated thermocouple and a nearby reference thermocouple inserted into the sapwood. This relationship has been widely tested but mostly with newly installed sensors. Increasingly, sensors are used for extended periods...

  2. Flow cytometric and microscopic analysis of the effect of tannic acid on plant nuclei and estimation of DNA content

    Czech Academy of Sciences Publication Activity Database

    Loureiro, J.; Rodriguez, E.; Doležel, Jaroslav; Santos, C.

    2006-01-01

    Roč. 98, - (2006), s. 515-527 ISSN 0305-7364 R&D Projects: GA MŠk(CZ) LC06004 Institutional research plan: CEZ:AV0Z50380511 Keywords : genome size * flow cytometry * nuclear DNA content Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.448, year: 2006

  3. Vehicle Infrastructure Cash-Flow Estimation--VICE 2.0; Clean Cities, Energy Efficiency & Renewable Energy (EERE)

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, G.

    2015-04-02

    This presentation discusses the differences between the original Vehicle and Infrastructure Cash-Flow Evaluation (VICE) Model and the revamped version, VICE 2.0. The enhanced tool can now help assess projects to acquire vehicles and infrastructure, or to acquire vehicles only.

  4. Solution of Inverse Problems using Bayesian Approach with Application to Estimation of Material Parameters in Darcy Flow

    Czech Academy of Sciences Publication Activity Database

    Domesová, Simona; Beres, Michal

    2017-01-01

    Roč. 15, č. 2 (2017), s. 258-266 ISSN 1336-1376 R&D Projects: GA MŠk LQ1602 Institutional support: RVO:68145535 Keywords : Bayesian statistics * Cross-Entropy method * Darcy flow * Gaussian random field * inverse problem Subject RIV: BA - General Mathematics OBOR OECD: Applied mathematics http://advances.utc.sk/index.php/AEEE/article/view/2236

  5. Impact of using different blood donor subpopulations and models on the estimation of transfusion transmission residual risk of human immunodeficiency virus, hepatitis B virus, and hepatitis C virus in Zimbabwe

    NARCIS (Netherlands)

    Mapako, Tonderai; Janssen, Mart P.; Mvere, David A.; Emmanuel, Jean C.; Rusakaniko, Simbarashe; Postma, Maarten J.; van Hulst, Marinus

    BACKGROUND: Various models for estimating the residual risk (RR) of transmission of infections by blood transfusion have been published mainly based on data from high-income countries. However, to obtain the data required for such an assessment remains challenging for most developing settings. The

  6. Impact of using different blood donor subpopulations and models on the estimation of transfusion transmission residual risk of human immunodeficiency virus, hepatitis B virus, and hepatitis C virus in Zimbabwe

    NARCIS (Netherlands)

    Mapako, Tonderai; Janssen, Mart P.; Mvere, David A.; Emmanuel, Jean C.; Rusakaniko, Simbarashe; Postma, Maarten J.; Van Hulst, Marinus

    2016-01-01

    BACKGROUND Various models for estimating the residual risk (RR) of transmission of infections by blood transfusion have been published mainly based on data from high-income countries. However, to obtain the data required for such an assessment remains challenging for most developing settings. The

  7. Higher Order Numerical Methods and Use of Estimation Techniques to Improve Modeling of Two-Phase Flow in Pipelines and Wells

    Energy Technology Data Exchange (ETDEWEB)

    Lorentzen, Rolf Johan

    2002-04-01

    The main objective of this thesis is to develop methods which can be used to improve predictions of two-phase flow (liquid and gas) in pipelines and wells. More reliable predictions are accomplished by improvements of numerical methods, and by using measured data to tune the mathematical model which describes the two-phase flow. We present a way to extend simple numerical methods to second order spatial accuracy. These methods are implemented, tested and compared with a second order Godunov-type scheme. In addition, a new (and faster) version of the Godunov-type scheme utilizing primitive (observable) variables is presented. We introduce a least squares method which is used to tune parameters embedded in the two-phase flow model. This method is tested using synthetic generated measurements. We also present an ensemble Kalman filter which is used to tune physical state variables and model parameters. This technique is tested on synthetic generated measurements, but also on several sets of full-scale experimental measurements. The thesis is divided into an introductory part, and a part consisting of four papers. The introduction serves both as a summary of the material treated in the papers, and as supplementary background material. It contains five sections, where the first gives an overview of the main topics which are addressed in the thesis. Section 2 contains a description and discussion of mathematical models for two-phase flow in pipelines. Section 3 deals with the numerical methods which are used to solve the equations arising from the two-phase flow model. The numerical scheme described in Section 3.5 is not included in the papers. This section includes results in addition to an outline of the numerical approach. Section 4 gives an introduction to estimation theory, and leads towards application of the two-phase flow model. The material in Sections 4.6 and 4.7 is not discussed in the papers, but is included in the thesis as it gives an important validation

  8. Diamagnetic susceptibility of a confined donor in inhomogeneous quantum dots

    International Nuclear Information System (INIS)

    Rahmani, K; Zorkani, I; Jorio, A

    2011-01-01

    The binding energy and diamagnetic susceptibility χ dia are estimated for a shallow donor confined to move in GaAs-GaAlAs inhomogeneous quantum dots. The calculation was performed within the effective mass approximation and using the variational method. The results show that the binding energy and the diamagnetic susceptibility χ dia depend strongly on the core radius and the shell radius. We have demonstrated that there is a critical value of the ratio of the inner radius to the outer radius which may be important for nanofabrication techniques. The binding energy E b shows a minimum for a critical value of this ratio depending on the value of the outer radius and shows a maximum when the donor is placed at the center of the spherical layer. The diamagnetic susceptibility is more sensitive to variations of the radius for a large spherical layer. The binding energy and diamagnetic susceptibility depend strongly on the donor position.

  9. For Donors Who Have Everything.

    Science.gov (United States)

    Shubeck, Theresa

    1990-01-01

    Most major donors don't need another plaque or formal dinner. Development officers need to be more imaginative and less materialistic in expressing their institution's thanks, personalizing them by tying the gesture in with something distinctive about the institution or the gift. Development office teamwork and care help promote donor…

  10. Being a Living Donor: Risks

    Science.gov (United States)

    ... to know FAQ Living donation What is living donation? Organs Types Being a living donor First steps Being ... are considering one of these types of living donation, please talk to your transplant center about the organ-specific risks. Psychological concerns You may also have ...

  11. Quantitative testing of the methodology for genome size estimation in plants using flow cytometry: a case study of the Primulina genus

    Directory of Open Access Journals (Sweden)

    Jing eWang

    2015-05-01

    Full Text Available Flow cytometry (FCM is a commonly used method for estimating genome size in many organisms. The use of flow cytometry in plants is influenced by endogenous fluorescence inhibitors and may cause an inaccurate estimation of genome size; thus, falsifying the relationship between genome size and phenotypic traits/ecological performance. Quantitative optimization of FCM methodology minimizes such errors, yet there are few studies detailing this methodology. We selected the genus Primulina, one of the most representative and diverse genera of the Old World Gesneriaceae, to evaluate the methodology effect on determining genome size. Our results showed that buffer choice significantly affected genome size estimation in six out of the eight species examined and altered the 2C-value (DNA content by as much as 21.4%. The staining duration and propidium iodide (PI concentration slightly affected the 2C-value. Our experiments showed better histogram quality when the samples were stained for 40 minutes at a PI concentration of 100 µg ml-1. The quality of the estimates was not improved by one-day incubation in the dark at 4 °C or by centrifugation. Thus, our study determined an optimum protocol for genome size measurement in Primulina: LB01 buffer supplemented with 100 µg ml-1 PI and stained for 40 minutes. This protocol also demonstrated a high universality in other Gesneriaceae genera. We report the genome size of nine Gesneriaceae species for the first time. The results showed substantial genome size variation both within and among the species, with the 2C-value ranging between 1.62 and 2.71 pg. Our study highlights the necessity of optimizing the FCM methodology prior to obtaining reliable genome size estimates in a given taxon.

  12. Optimal estimate of the coolant flow in the assemblies of a BWR of natural circulation in real time; Estimacion optima del flujo de refrigerante en los ensambles de un BWR de circulacion natural en tiempo real

    Energy Technology Data Exchange (ETDEWEB)

    Valle H, J.; Morales S, J. B. [UNAM, Facultad de Ingenieria, Division de Estudios de Posgrado, Laboratorio de Analisis de Ingenieria de Reactores Nucleares, Paseo Cuauhnahuac 8532, Col. Progreso, 62550 Jiutepec, Morelos (Mexico); Espinosa P, G., E-mail: julfi_jg@yahoo.com.mx [Universidad Autonoma Metropolitana, Unidad Iztapalapa, Av. San Rafael Atlixco 186, Col. Vicentina, 09340 Mexico D. F. (Mexico)

    2012-10-15

    The present work exposes the design and the implementation of an advanced controller that allows estimating the coolant flow in the fuel assemblies of a BWR reactor of natural circulation in real time. To be able to reduce the penalizations that are established in the calculations of the operation limits due to the magnitude of the uncertainties in the coolant flows of a natural circulation reactor, is the objective of this research. In this work the construction of the optimal controller that allows estimating the coolant flows in a fuel channels group of the reactor is shown, as well as the operation of this applied to a reduced order model that simulates the dynamics of a natural circulation reactor. The controller design required of an estimator of the valuation variables not directly of the plant and of the estimates use of the local distributions of the coolant flow. The controller construction of the estimator was based mathematically in the filter Kalman whose algorithm allows to be carried out an advanced control of the system. To prove the estimator operation was development a simplified model that reproduces the basic dynamics of the flowing coolant in the reactor, which works as observer of the system, this model is coupled by means of the estimator controller to a detail model of the plant. The results are presented by means of graphics of the interest variables and the estimate flow, and they are documented in the chart that is presented at the end of this article. (Author)

  13. Selection of a Suitable Wall Pressure Spectrum Model for Estimating Flow-Induced Noise in Sonar Applications

    Directory of Open Access Journals (Sweden)

    V. Bhujanga Rao

    1995-01-01

    Full Text Available Flow-induced structural noise of a sonar dome in which the sonar transducer is housed, constitutes a major source of self-noise above a certain speed of the vessel. Excitation of the sonar dome structure by random pressure fluctuations in turbulent boundary layer flow leads to acoustic radiation into the interior of the dome. This acoustic radiation is termed flow-induced structural noise. Such noise contributes significantly to sonar self-noise of submerged vessels cruising at high speed and plays an important role in surface ships, torpedos, and towed sonars as well. Various turbulent boundary layer wall pressure models published were analyzed and the most suitable analytical model for the sonar dome application selected while taking into account high frequency, fluid loading, low wave number contribution, and pressure gradient effects. These investigations included type of coupling that exists between turbulent boundary layer pressure fluctuations and dome wall structure of a typical sonar dome. Comparison of theoretical data with measured data onboard a ship are also reported.

  14. A dynamic model-based estimate of the value of a vanadium redox flow battery for frequency regulation in Texas

    International Nuclear Information System (INIS)

    Fares, Robert L.; Meyers, Jeremy P.; Webber, Michael E.

    2014-01-01

    Highlights: • A model is implemented to describe the dynamic voltage of a vanadium flow battery. • The model is used with optimization to maximize the utility of the battery. • A vanadium flow battery’s value for regulation service is approximately $1500/kW. - Abstract: Building on past work seeking to value emerging energy storage technologies in grid-based applications, this paper introduces a dynamic model-based framework to value a vanadium redox flow battery (VRFB) participating in Texas’ organized electricity market. Our model describes the dynamic behavior of a VRFB system’s voltage and state of charge based on the instantaneous charging or discharging power required from the battery. We formulate an optimization problem that incorporates the model to show the potential value of a VRFB used for frequency regulation service in Texas. The optimization is implemented in Matlab using the large-scale, interior-point, nonlinear optimization algorithm, with the objective function gradient, nonlinear constraint gradients, and Hessian matrix specified analytically. Utilizing market prices and other relevant data from the Electric Reliability Council of Texas (ERCOT), we find that a VRFB system used for frequency regulation service could be worth approximately $1500/kW

  15. On the coupled use of eddy covariance, sap flow sensors and remote sensing information for Evapotranspiration estimates in a typical heterogeneous Mediterranean ecosystem.

    Science.gov (United States)

    Corona, R.; Montaldo, N.

    2017-12-01

    Mediterranean ecosystems are typically heterogeneous, with contrasting plant functional types (PFT, woody vegetation and grass) that compete for water use. Due to the complexity of these ecosystems there is still uncertainty on the estimate of the evapotranspiration (ET). Micrometerological measurements (e.g. eddy covariance method based, EC ) are widely used for ET estimate, but in heterogeneous systems one of the main assumption (surface homogeneity) is not preserved and the method may become less robust. In this sense, the coupled use of sap flow sensors for tree transpiration estimate, surface temperature sensors, remote sensing information for land surface characterization allow to estimate the ET components and the energy balances of the three main land surface components (woody vegetation, grass and bare soil), overtaking the EC method uncertainties. The experimental site of Orroli, in Sardinia (Italy), is a typical Mediterranean heterogeneous ecosystem, monitored from the University of Cagliari since 2003. With the intent to perform an intensive field campaign for the ET estimation, we verified the potentiality of coupling eddy covariance (EC) method, infrared sensors and thermal dissipation methods (i.e. sap flow technique) for tree transpiration estimate. As a first step 3 commercial sap flux sensors were installed in a wild olive clump where the skin temperature of one tree in the clump was monitored with an infrared transducer. Then, other 54 handmade sensors were installed in 14 clumps in the EC footprint. Measurements of diameter were recorded in all the clumps and the sapwood depth was derived from measurements in several trees. The field ET estimation from the 4 commercial sensors was obtained assuming 4 different relationship between the monitored sap flux and the diameter of the species in the footprint. Instead for the 54 handmade sensors a scaling procedure was applied based on the allometric relationships between sapwood area, diameter and

  16. Hypophosphatemia after Right Hepatectomy for Living Donor Liver Transplantation

    Directory of Open Access Journals (Sweden)

    Kelly W Burak

    2004-01-01

    Full Text Available Hypophosphatemia has been described in patients undergoing right hepatectomy for liver cancer and in living donors for liver transplantation who also received total parenteral nutrition. At the study centre, significant hypophosphatemia (0.36 mmol/L or less requiring intravenous replacement was seen in two of the first nine living donors for adult-to-adult liver transplantation. To determine the frequency of hypophosphatemia in living donors, the authors obtained phosphate levels on stored serum samples from postoperative days 0, 1, 3 and 7 in all nine patients, none of whom were on total parenteral nutrition. Within the first week, hypophosphatemia developed in 55.6% of patients and phosphate levels returned to normal by day 7 in all nine patients. One patient had normal phosphate levels during the first week, but had profound hypophosphatemia (0.32 mmol/L on day 14 when he presented with a Staphylococcus aureus infection of a bile collection and significant hypoxemia. The extent of hepatectomy and the rate of liver regeneration, estimated by baseline and postoperative day 7 volumetric computed tomography scans, did not correlate with the development of hypophosphatemia. In conclusion, hypophosphatemia is common in living donors undergoing right hepatectomy and may be associated with complications. All living donors should be monitored for the development of hypophosphatemia during the first two postoperative weeks.

  17. Estimating reservoir permeability from gravity current modeling of CO2 flow at Sleipner storage project, North Sea

    Science.gov (United States)

    Cowton, L. R.; Neufeld, J. A.; Bickle, M.; White, N.; White, J.; Chadwick, A.

    2017-12-01

    Vertically-integrated gravity current models enable computationally efficient simulations of CO2 flow in sub-surface reservoirs. These simulations can be used to investigate the properties of reservoirs by minimizing differences between observed and modeled CO2 distributions. At the Sleipner project, about 1 Mt yr-1 of supercritical CO2 is injected at a depth of 1 km into a pristine saline aquifer with a thick shale caprock. Analysis of time-lapse seismic reflection surveys shows that CO2 is distributed within 9 discrete layers. The trapping mechanism comprises a stacked series of 1 m thick, impermeable shale horizons that are spaced at 30 m intervals through the reservoir. Within the stratigraphically highest reservoir layer, Layer 9, a submarine channel deposit has been mapped on the pre-injection seismic survey. Detailed measurements of the three-dimensional CO2 distribution within Layer 9 have been made using seven time-lapse surveys, providing a useful benchmark against which numerical flow simulations can be tested. Previous simulations have, in general, been largely unsuccessful in matching the migration rate of CO2 in this layer. Here, CO2 flow within Layer 9 is modeled as a vertically-integrated gravity current that spreads beneath a structurally complex caprock using a two-dimensional grid, considerably increasing computational efficiency compared to conventional three-dimensional simulators. This flow model is inverted to find the optimal reservoir permeability in Layer 9 by minimizing the difference between observed and predicted distributions of CO2 as a function of space and time. A three parameter inverse model, comprising reservoir permeability, channel permeability and channel width, is investigated by grid search. The best-fitting reservoir permeability is 3 Darcys, which is consistent with measurements made on core material from the reservoir. Best-fitting channel permeability is 26 Darcys. Finally, the ability of this simplified numerical model

  18. Associations of health status with subsequent blood donor behavior-An alternative perspective on the Healthy Donor Effect from Donor InSight

    NARCIS (Netherlands)

    van den Hurk, Katja; Zalpuri, Saurabh; Prinsze, Femmeke J.; Merz, Eva-Maria; de Kort, Wim L. A. M.

    2017-01-01

    In donor health research, the 'Healthy Donor Effect' (HDE) often biases study results and hampers their interpretation. This refers to the fact that donors are a selected 'healthier' subset of a population due to both donor selection procedures and self-selection. Donors with long versus short donor

  19. Development of an integrated sampler based on direct 222Rn/220Rn progeny sensors in flow-mode for estimating unattached/attached progeny concentration

    International Nuclear Information System (INIS)

    Mishra, Rosaline; Sapra, B.K.; Mayya, Y.S.

    2009-01-01

    A flow-mode integrated sampler consisting of a wire-mesh and filter-paper array along with passive solid state nuclear track detectors has been developed for estimating unattached and attached fraction of 222 Rn/ 220 Rn progeny concentration. The essential element of this sampler is the direct 222 Rn/ 220 Rn progeny sensor (DRPS/DTPS), which is an absorber-mounted-LR115 type nuclear track detector that selectively registers the alpha particles emitted from the progeny deposited on its surface. During sampling at a specified flow-rate, the unattached progeny is captured on the wire-mesh; while the attached progeny gets transmitted and is captured on the filter-paper. The alpha particles emitted by the deposited progeny atoms are registered on the sensors placed at a specified distance facing the wire-mesh and the filter-paper, respectively. The various steps involved in the development of this flow-mode direct progeny sampler such as the optimization of the sampling rate and the distance between the sensor and the deposition substrate are discussed. The sensitivity factor of the DTPS-loaded sampler for 220 Rn progeny deposited on the wire-mesh and filter-paper is found to be 23.77 ± 0.64 (track cm -2 h -1 ) (Bq m -3 ) -1 and 22.30 ± 0.18 (track cm -2 h -1 ) (Bq m -3 ) -1 , respectively; while that of DRPS-loaded sampler for 222 Rn progeny deposition, is 3.03 ± 0.14 (track cm -2 h -1 ) (Bq m -3 ) -1 and 2.08 ± 0.07 (track cm -2 h -1 ) (Bq m -3 ) -1 , respectively. The highlight of this flow-mode sampler is its high sensitivity and that it utilizes the passive technique for estimating the unattached and attached progeny concentration, thus doing away with the alpha counting procedures.

  20. Estimation of suspended sediment flux in streams using continuous turbidity and flow data coupled with laboratory concentrations

    Science.gov (United States)

    Jack Lewis

    2002-01-01

    The widening use of sediment surrogate measurements such as turbidity necessitates consideration of new methods for estimating sediment flux. Generally, existing methods can be simply be used in new ways. The effectiveness of a method varies according to the quality of the surrogate data and its relation to suspended sediment concentration (SSC). For this discussion,...

  1. Cerebral Blood Flow and A beta-Amyloid Estimates by WARAM Analysis of [C-11]PiB Uptake Distinguish among and between Neurodegenerative Disorders and Aging

    DEFF Research Database (Denmark)

    Rodell, Anders B.; O'Keefe, Graeme; Rowe, Christopher C.

    2017-01-01

    Alzheimer’s disease, and healthy volunteers. The method introduces two approaches to the identification of brain pathology related to amyloid accumulation, (1) a novel analysis of amyloid binding based on the late washout of the tracer from brain tissue, and (2) the simultaneous estimation of absolute...... metabolism and reduction of blood flow by neurovascular coupling in neurodegenerative disorders, including Alzheimer’s disease. Methods: Previously reported images of [11C]PiB retention in brain of 29 subjects with cognitive impairment or dementia [16 Alzheimer’s Disease (AD), eight subjects with dementia...

  2. Can value for money be improved by changing the sequence of our donor work-up in the living kidney donor programme?

    Science.gov (United States)

    Larsen, Jesper; Sørensen, Søren Schwartz; Feldt-Rasmussen, Bo

    2009-08-01

    The aim of the study was to identify procedures of maximum importance for acceptance or rejection of kidney donation from a living donor as well as making the process more cost-effective. We identified all potential living related donors who were examined during the period between January 2002 and December 2006 at our department. The cost in euro (euro) for the programme was estimated using the Danish diagnosis-related group-system (DRG). The donor work-up programme was described. One hundred and thirty-three potential donors were identified; 66 male- and 67 female subjects, median age of 52 years (range 22-69). Sixty-four participants were rejected as donors. Abdominal CT-scan with angiography and urography ruled out 22 of the above 64 potential organ donors; thus, 48% of the volunteers for living kidney donation were unsuited for donation. Abdominal CT-scan with angiography and urography was the procedure identifying most subjects who were unsuited for kidney donation. A rearrangement of the present donor work-up programme could potentially reduce the costs from euro6911 to euro5292 per donor--saving 23% of the costs. By changing the sequence of examinations, it might be possible to cut down on time spent and number of tests needed for approving or rejecting subjects for living kidney donation.

  3. Estimation of cardiac motion in cine-MRI sequences by correlation transform optical flow of monogenic features distance

    Science.gov (United States)

    Gao, Bin; Liu, Wanyu; Wang, Liang; Liu, Zhengjun; Croisille, Pierre; Delachartre, Philippe; Clarysse, Patrick

    2016-12-01

    Cine-MRI is widely used for the analysis of cardiac function in clinical routine, because of its high soft tissue contrast and relatively short acquisition time in comparison with other cardiac MRI techniques. The gray level distribution in cardiac cine-MRI is relatively homogenous within the myocardium, and can therefore make motion quantification difficult. To ensure that the motion estimation problem is well posed, more image features have to be considered. This work is inspired by a method previously developed for color image processing. The monogenic signal provides a framework to estimate the local phase, orientation, and amplitude, of an image, three features which locally characterize the 2D intensity profile. The independent monogenic features are combined into a 3D matrix for motion estimation. To improve motion estimation accuracy, we chose the zero-mean normalized cross-correlation as a matching measure, and implemented a bilateral filter for denoising and edge-preservation. The monogenic features distance is used in lieu of the color space distance in the bilateral filter. Results obtained from four realistic simulated sequences outperformed two other state of the art methods even in the presence of noise. The motion estimation errors (end point error) using our proposed method were reduced by about 20% in comparison with those obtained by the other tested methods. The new methodology was evaluated on four clinical sequences from patients presenting with cardiac motion dysfunctions and one healthy volunteer. The derived strain fields were analyzed favorably in their ability to identify myocardial regions with impaired motion.

  4. FLAIR vascular hyperintensities and dynamic 4D angiograms for the estimation of collateral blood flow in posterior circulation occlusion

    International Nuclear Information System (INIS)

    Foerster, Alex; Wenz, Holger; Kerl, Hans Ulrich; Al-Zghloul, Mansour; Habich, Sonia; Groden, Christoph

    2014-01-01

    The objectives of this paper are to assess collateral blood flow in posterior circulation occlusion by MRI-based approaches (fluid-attenuated inversion recovery (FLAIR) vascular hyperintensities (FVHs), collateralization on dynamic 4D angiograms) and investigate its relation to ischemic lesion size and growth. In 28 patients with posterior cerebral artery (PCA) and 10 patients with basilar artery (BA) occlusion, MRI findings were analyzed, with emphasis on distal FVH and collateralization on dynamic 4D angiograms. In PCA occlusion, distal FVH was observed in 18/29 (62.1 %), in BA occlusion, in 8/10 (80 %) cases. Collateralization on dynamic 4D angiograms was graded 1 in 8 (27.6 %) patients, 2 in 1 (3.4 %) patient, 3 in 12 (41.4 %) patients, and 4 in 8 (27.6 %) patients with PCA occlusion and 0 in 1 (10 %) patient, 2 in 3 (30 %) patients, 3 in 1 (10 %) patient, and 4 in 5 (50 %) patients with BA occlusion. FVH grade showed neither correlation with initial or follow-up diffusion-weighted image (DWI) lesion size nor DWI-perfusion-weighted imaging (PWI) mismatch ratio. Collateralization on dynamic 4D angiograms correlated inversely with initial DWI lesion size and moderately with the DWI-(PWI) mismatch ratio. The combination of distal FVH and collateralization grade on dynamic 4D angiograms correlated inversely with initial as well as follow-up DWI lesion size and highly with the DWI-PWI mismatch ratio. In posterior circulation occlusion, FVH is a frequent finding, but its prognostic value is limited. Dynamic 4D angiograms are advantageous to examine and graduate collateral blood flow. The combination of both parameters results in an improved characterization of collateral blood flow and might have prognostic relevance. (orig.)

  5. Cerebral Blood Flow and A beta-Amyloid Estimates by WARM Analysis of [C-11]PiB Uptake Distinguish among and between Neurodegenerative Disorders and Aging

    DEFF Research Database (Denmark)

    Rodell, Anders B.; O'Keefe, Graeme; Rowe, Christopher C.

    2017-01-01

    groups as a whole, sCBF estimates revealed the greatest discrimination between the patient and HC groups. WARM resolves a major issue of amyloid load quantification with [11C]PiB in human brain by determining absolute sCBF and amyloid load measures from the same images. The two parameter approach......Background: We report results of the novel Washout Allometric Reference Method (WARM) that uses estimates of cerebral blood flow and amyloid load from the same [11C]Pittsburgh Compound B ([11C]PiB) retention maps in brain to distinguish between patients with different forms dementia, including...... with Lewy bodies (DLB), five patients with frontotemporal lobar degeneration (FTLD), five patients with mild cognitive impairment, and 29 age-matched healthy control subjects (HC)], underwent analysis of PiB delivery and retention by means of WARM for quantitation of [11C]PiB's binding potentials (BPND...

  6. Influence of donor-donor transport on excitation energy transfer

    Energy Technology Data Exchange (ETDEWEB)

    Pandey, K K; Joshi, H C; Pant, T C [Kumaun University, Nainital (India). Department of Physics

    1989-01-01

    Energy migration and transfer from acriflavine to rhodamine B and malachite green in poly (methylmethacrylate) have been investigated using the decay function analysis. It is found that the influence of energy migration in energy transfer can be described quite convincingly by making use of the theories of Loring, Andersen and Fayer (LAF) and Huber. At high acceptor concentration direct donor-acceptor transfer occurs through Forster mechanism. (author). 17 refs., 5 figs.

  7. Establishment of an oocyte donor program. Donor screening and selection.

    Science.gov (United States)

    Quigley, M M; Collins, R L; Schover, L R

    1991-01-01

    IVF with donated oocytes, followed by embryo placement in the uterus of a recipient who has been primed with exogenous steroids, is a successful treatment for special cases of infertility. Preliminary results indicate that the success rate in this situation is even greater than that usually seen with normal IVF (with placement of the embryos back into the uteri of the women from whom the oocytes were recovered). Although different sources for donated oocytes have been identified, the use of "excess" oocytes from IVF cycles and the attempted collection of oocytes at the time of otherwise indicated pelvic surgery have ethical and practical problems associated with their use. We have herein described the establishment of a successful program relying on anonymous volunteers who go through ovarian stimulation, monitoring, and oocyte recovery procedures solely to donate oocytes. The potential donors go through an exhaustive screening and education process before they are accepted in the program. Psychological evaluation of our potential donors indicated a great degree of turmoil in their backgrounds and a wide variety of motivations for actually participating. Despite the extensive educational and screening process, a substantial percentage of the donors did not complete a donation cycle, having either voluntarily withdrawn or been dropped because of lack of compliance. Further investigation of the psychological aspects of participating in such a program is certainly warranted. The use of donated oocytes to alleviate specific types of infertility is quite successful, but the application of this treatment is likely to be limited by the relative unavailability of suitable oocyte donors.

  8. 2-D left ventricular flow estimation by combining speckle tracking with Navier-Stokes-based regularization: an in silico, in vitro and in vivo study.

    Science.gov (United States)

    Gao, Hang; Bijnens, Nathalie; Coisne, Damien; Lugiez, Mathieu; Rutten, Marcel; D'hooge, Jan

    2015-01-01

    Despite the availability of multiple ultrasound approaches to left ventricular (LV) flow characterization in two dimensions, this technique remains in its childhood and further developments seem warranted. This article describes a new methodology for tracking the 2-D LV flow field based on ultrasound data. Hereto, a standard speckle tracking algorithm was modified by using a dynamic kernel embedding Navier-Stokes-based regularization in an iterative manner. The performance of the proposed approach was first quantified in synthetic ultrasound data based on a computational fluid dynamics model of LV flow. Next, an experimental flow phantom setup mimicking the normal human heart was used for experimental validation by employing simultaneous optical particle image velocimetry as a standard reference technique. Finally, the applicability of the approach was tested in a clinical setting. On the basis of the simulated data, pointwise evaluation of the estimated velocity vectors correlated well (mean r = 0.84) with the computational fluid dynamics measurement. During the filling period of the left ventricle, the properties of the main vortex obtained from the proposed method were also measured, and their correlations with the reference measurement were also calculated (radius, r = 0.96; circulation, r = 0.85; weighted center, r = 0.81). In vitro results at 60 bpm during one cardiac cycle confirmed that the algorithm properly measures typical characteristics of the vortex (radius, r = 0.60; circulation, r = 0.81; weighted center, r = 0.92). Preliminary qualitative results on clinical data revealed physiologic flow fields. Copyright © 2015 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  9. Live donor transplantation--the incompetent donor: comparative law.

    Science.gov (United States)

    Wolfman, Samuel; Shaked, Tali

    2008-12-01

    Informed consent of the patient to medical treatment is an essential prerequisite for any invasive medical procedure. However in emergency cases, when the patient is unable to sign a consent form due to unconsciousness or to psychotic state, than the primary medical consideration shall take place. In such a case, in order to save life or even prevent a major medical hazard to the patient, doctors are allowed, in certain cases and in accordance with well accepted medical practice, to perform invasive procedures, major surgery or risky pharmacological treatment, without the explicit consent of the patient. All the above refers to the cases when avoidance of such non-consented treatment may harm severely the health and wellbeing of the patient and there is no doubt that such treatment is for the ultimate benefit of the patient. The question, however, shall arise when such a medical procedure is not necessarily for the benefit of the patient, but rather for the benefit of somebody else. Such is the case in the transplantation area and the question of living donor-donee relationship. This paper shall analyze the legal situation in cases of non competent donors whose consent cannot be considered legal consent given in full understanding and out of free will. It will also compare three legal systems, the Israeli, the American and the traditional Jewish law, with regard to the different approaches to this human problem, where the autonomy of the donor may be sacrificed for the purpose of saving life of another person.

  10. Quantification of transplant-derived circulating cell-free DNA in absence of a donor genotype.

    Science.gov (United States)

    Sharon, Eilon; Shi, Hao; Kharbanda, Sandhya; Koh, Winston; Martin, Lance R; Khush, Kiran K; Valantine, Hannah; Pritchard, Jonathan K; De Vlaminck, Iwijn

    2017-08-01

    Quantification of cell-free DNA (cfDNA) in circulating blood derived from a transplanted organ is a powerful approach to monitoring post-transplant injury. Genome transplant dynamics (GTD) quantifies donor-derived cfDNA (dd-cfDNA) by taking advantage of single-nucleotide polymorphisms (SNPs) distributed across the genome to discriminate donor and recipient DNA molecules. In its current implementation, GTD requires genotyping of both the transplant recipient and donor. However, in practice, donor genotype information is often unavailable. Here, we address this issue by developing an algorithm that estimates dd-cfDNA levels in the absence of a donor genotype. Our algorithm predicts heart and lung allograft rejection with an accuracy that is similar to conventional GTD. We furthermore refined the algorithm to handle closely related recipients and donors, a scenario that is common in bone marrow and kidney transplantation. We show that it is possible to estimate dd-cfDNA in bone marrow transplant patients that are unrelated or that are siblings of the donors, using a hidden Markov model (HMM) of identity-by-descent (IBD) states along the genome. Last, we demonstrate that comparing dd-cfDNA to the proportion of donor DNA in white blood cells can differentiate between relapse and the onset of graft-versus-host disease (GVHD). These methods alleviate some of the barriers to the implementation of GTD, which will further widen its clinical application.

  11. Quantification of transplant-derived circulating cell-free DNA in absence of a donor genotype.

    Directory of Open Access Journals (Sweden)

    Eilon Sharon

    2017-08-01

    Full Text Available Quantification of cell-free DNA (cfDNA in circulating blood derived from a transplanted organ is a powerful approach to monitoring post-transplant injury. Genome transplant dynamics (GTD quantifies donor-derived cfDNA (dd-cfDNA by taking advantage of single-nucleotide polymorphisms (SNPs distributed across the genome to discriminate donor and recipient DNA molecules. In its current implementation, GTD requires genotyping of both the transplant recipient and donor. However, in practice, donor genotype information is often unavailable. Here, we address this issue by developing an algorithm that estimates dd-cfDNA levels in the absence of a donor genotype. Our algorithm predicts heart and lung allograft rejection with an accuracy that is similar to conventional GTD. We furthermore refined the algorithm to handle closely related recipients and donors, a scenario that is common in bone marrow and kidney transplantation. We show that it is possible to estimate dd-cfDNA in bone marrow transplant patients that are unrelated or that are siblings of the donors, using a hidden Markov model (HMM of identity-by-descent (IBD states along the genome. Last, we demonstrate that comparing dd-cfDNA to the proportion of donor DNA in white blood cells can differentiate between relapse and the onset of graft-versus-host disease (GVHD. These methods alleviate some of the barriers to the implementation of GTD, which will further widen its clinical application.

  12. Electrical Manipulation of Donor Spin Qubits in Silicon and Germanium

    Science.gov (United States)

    Sigillito, Anthony James

    Many proposals for quantum information devices rely on electronic or nuclear spins in semiconductors because of their long coherence times and compatibility with industrial fabrication processes. One of the most notable qubits is the electron spin bound to phosphorus donors in silicon, which offers coherence times exceeding seconds at low temperatures. These donors are naturally isolated from their environments to the extent that silicon has been coined a "semiconductor vacuum". While this makes for ultra-coherent qubits, it is difficult to couple two remote donors so quantum information proposals rely on high density arrays of qubits. Here, single qubit addressability becomes an issue. Ideally one would address individual qubits using electric fields which can be easily confined. Typically these schemes rely on tuning a donor spin qubit onto and off of resonance with a magnetic driving field. In this thesis, we measure the electrical tunability of phosphorus donors in silicon and use the extracted parameters to estimate the effects of electric-field noise on qubit coherence times. Our measurements show that donor ionization may set in before electron spins can be sufficiently tuned. We therefore explore two alternative options for qubit addressability. First, we demonstrate that nuclear spin qubits can be directly driven using electric fields instead of magnetic fields and show that this approach offers several advantages over magnetically driven spin resonance. In particular, spin transitions can occur at half the spin resonance frequency and double quantum transitions (magnetic-dipole forbidden) can occur. In a second approach to realizing tunable qubits in semiconductors, we explore the option of replacing silicon with germanium. We first measure the coherence and relaxation times for shallow donor spin qubits in natural and isotopically enriched germanium. We find that in isotopically enriched material, coherence times can exceed 1 ms and are limited by a

  13. Flow regimes

    International Nuclear Information System (INIS)

    Liles, D.R.

    1982-01-01

    Internal boundaries in multiphase flow greatly complicate fluid-dynamic and heat-transfer descriptions. Different flow regimes or topological configurations can have radically dissimilar interfacial and wall mass, momentum, and energy exchanges. To model the flow dynamics properly requires estimates of these rates. In this paper the common flow regimes for gas-liquid systems are defined and the techniques used to estimate the extent of a particular regime are described. Also, the current computer-code procedures are delineated and introduce a potentially better method is introduced

  14. Alternative allogeneic donor sources for transplantation for childhood diseases: unrelated cord blood and haploidentical family donors.

    Science.gov (United States)

    Cairo, Mitchell S; Rocha, Vanderson; Gluckman, Eliane; Hale, Gregory; Wagner, John

    2008-01-01

    Allogeneic stem cell transplantation has been demonstrated to be curative in a wide variety of pediatric malignant and nonmalignant diseases, and can be traced back over 50 years ago to the original report of Thomas et al. HLA matched sibling donors have been the gold standard for pediatric recipients requiring allogeneic donors for both nonmalignant and malignant conditions. However, only 25% of potential pediatric recipients possesses an HLA-matched sibling donor, and the frequency is even less in those with genetic nonmalignant conditions because of genetically affected other siblings within the family. Therefore, 75% to 90% of potential pediatric recipients require alternative allogeneic donor cells for treatment of their underlying conditions. Potential alternative allogeneic donor sources include unrelated cord blood donors, unrelated adult donors, and haploidentical family donors. In this article we review the experience of both unrelated cord blood donor and haploidentical family donor transplants in selected pediatric malignant and nonmalignant conditions.

  15. Development of the system for the estimation of materials flow in pyrochemical reprocessing plant. Characteristic evaluation of the oxide electrowinning plant

    International Nuclear Information System (INIS)

    Okamura, Nobuo; Tozawa, Katuhiro; Sato, Koji

    2002-07-01

    The operation of the plant with the non-aqueous reprocessing technology depends on the materials handling equipment closely. Because the value of decontamination factor of the products in the plant is low, treatment of nuclear materials requires remote operation technology. So the system for the evaluation of materials flow in the plant was built to evaluate the production ability of the plant and to check out the plant operation from the viewpoint of materials flow. The system is only based on information of the treatment abilities of materials handling machines and process installations and the arrangement of process installations in the reprocessing cell that influences a way to operate materials handling machines intensity. Therefore the system can be used to estimate the characteristics of non-aqueous plants that are not in detail design stage. The amount of production and the characteristics of the oxide electrowinning plant (operation term 200days/year, plant capacity 50tHM/year in design) designed in Feasibility Study Phase1 were estimated using the system. The results show that the practical amount of production of the plant design is about 88% of the designed value. To increase the amount of production, it is more useful to speed up materials handling machine time than to install new installation or to give priority to conduct bottleneck processes. It is because materials handling influences the production ability of the plant deeply. (author)

  16. Blood donor: nursing care plan

    OpenAIRE

    Marco Antonio Zapata Sampedro; Laura Castro Varela

    2008-01-01

    The standardized nursing care plan can be used as a means through which the nurse will assess and identify the particular needs of the blood donor.To draw up the care plan, we have conducted the evaluation on the basis of the Marjory Gordon’s functional health patterns.The more prevailing diagnosis according to the NANDA taxonomy have been identified, results have been established according to the NOC (Nursing Outcomes Classification) taxonomy, and nursing interventions have been suggested ac...

  17. Modelling shallow landslide susceptibility by means of a subsurface flow path connectivity index and estimates of soil depth spatial distribution

    Directory of Open Access Journals (Sweden)

    C. Lanni

    2012-11-01

    Full Text Available Topographic index-based hydrological models have gained wide use to describe the hydrological control on the triggering of rainfall-induced shallow landslides at the catchment scale. A common assumption in these models is that a spatially continuous water table occurs simultaneously across the catchment. However, during a rainfall event isolated patches of subsurface saturation form above an impeding layer and their hydrological connectivity is a necessary condition for lateral flow initiation at a point on the hillslope.

    Here, a new hydrological model is presented, which allows us to account for the concept of hydrological connectivity while keeping the simplicity of the topographic index approach. A dynamic topographic index is used to describe the transient lateral flow that is established at a hillslope element when the rainfall amount exceeds a threshold value allowing for (a development of a perched water table above an impeding layer, and (b hydrological connectivity between the hillslope element and its own upslope contributing area. A spatially variable soil depth is the main control of hydrological connectivity in the model. The hydrological model is coupled with the infinite slope stability model and with a scaling model for the rainfall frequency–duration relationship to determine the return period of the critical rainfall needed to cause instability on three catchments located in the Italian Alps, where a survey of soil depth spatial distribution is available. The model is compared with a quasi-dynamic model in which the dynamic nature of the hydrological connectivity is neglected. The results show a better performance of the new model in predicting observed shallow landslides, implying that soil depth spatial variability and connectivity bear a significant control on shallow landsliding.

  18. FLAIR vascular hyperintensities and 4D MR angiograms for the estimation of collateral blood flow in anterior cerebral artery ischemia.

    Directory of Open Access Journals (Sweden)

    Matthias Gawlitza

    Full Text Available To assess FLAIR vascular hyperintensities (FVH and dynamic (4D angiograms derived from perfusion raw data as proposed magnetic resonance (MR imaging markers of leptomeningeal collateral circulation in patients with ischemia in the territory of the anterior cerebral artery (ACA.Forty patients from two tertiary care university hospitals were included. Infarct volumes and perfusion deficits were manually measured on DWI images and TTP maps, respectively. FVH and collateral flow on 4D MR angiograms were assessed and graded as previously specified.Forty-one hemispheres were affected. Mean DWI lesion volume was 8.2 (± 13.9; range 0-76.9 ml, mean TTP lesion volume was 24.5 (± 17.2, range 0-76.7 ml. FVH were observed in 26/41 (63.4% hemispheres. Significant correlations were detected between FVH and TTP lesion volume (ρ = 0.4; P<0.01 absolute (ρ = 0.37; P<0.05 and relative mismatch volume (ρ = 0.35; P<0.05. The modified ASITN/SIR score correlated inversely with DWI lesion volume (ρ = -0.58; P<0.01 and positively with relative mismatch (ρ = 0.29; P< 0.05. ANOVA of the ASITN/SIR score revealed significant inter-group differences for DWI (P<0.001 and TTP lesion volumes (P<0.05. No correlation was observed between FVH scores and modified ASITH/SIR scores (ρ = -0.16; P = 0.32.FVH and flow patterns on 4D MR angiograms are markers of perfusion deficits and tissue at risk. As both methods did not show a correlation between each other, they seem to provide complimentary instead of redundant information. Previously shown evidence for the meaning of these specific MR signs in internal carotid and middle cerebral artery stroke seems to be transferrable to ischemic stroke in the ACA territory.

  19. Estimation of time-variable fast flow path chemical concentrations for application in tracer-based hydrograph separation analyses

    Science.gov (United States)

    Kronholm, Scott C.; Capel, Paul D.

    2016-01-01

    Mixing models are a commonly used method for hydrograph separation, but can be hindered by the subjective choice of the end-member tracer concentrations. This work tests a new variant of mixing model that uses high-frequency measures of two tracers and streamflow to separate total streamflow into water from slowflow and fastflow sources. The ratio between the concentrations of the two tracers is used to create a time-variable estimate of the concentration of each tracer in the fastflow end-member. Multiple synthetic data sets, and data from two hydrologically diverse streams, are used to test the performance and limitations of the new model (two-tracer ratio-based mixing model: TRaMM). When applied to the synthetic streams under many different scenarios, the TRaMM produces results that were reasonable approximations of the actual values of fastflow discharge (±0.1% of maximum fastflow) and fastflow tracer concentrations (±9.5% and ±16% of maximum fastflow nitrate concentration and specific conductance, respectively). With real stream data, the TRaMM produces high-frequency estimates of slowflow and fastflow discharge that align with expectations for each stream based on their respective hydrologic settings. The use of two tracers with the TRaMM provides an innovative and objective approach for estimating high-frequency fastflow concentrations and contributions of fastflow water to the stream. This provides useful information for tracking chemical movement to streams and allows for better selection and implementation of water quality management strategies.

  20. Clinical and Biochemical Characteristics of Brain-Dead Donors as Predictors of Early- and Long-Term Renal Function After Transplant.

    Science.gov (United States)

    Kwiatkowska, Ewa; Domański, Leszek; Bober, Joanna; Safranow, Krzysztof; Pawlik, Andrzej; Ciechanowski, Kazimierz; Wiśniewska, Magda; Kędzierska, Karolina

    2017-08-01

    Organs from brain-dead donors are the main source of allografts for transplant. Comparisons between living-donor and brain-dead donor kidneys show that the latter are more likely to demonstrate delayed graft function and lower long-term survival. This study aimed to assess the effects of various clinical and biochemical factors of donors on early- and long-term renal function after transplant. We analyzed data from kidney recipients treated between 2006 and 2008 who received organs from brain-dead donors. Data from 54 donors and 89 recipients were analyzed. No relation was observed between donor sodium concentration and the presence of delayed graft function. Donor height was positively correlated with creatinine clearance in recipients in the 1 to 3 months after renal transplant. Donor diastolic blood pressure was negatively correlated with estimated glomerular filtration rate throughout the observation period. Donor age was negatively correlated with the allograft recipient's estimated glomerular filtration rate throughout 4 years of observation. Donor estimated glomerular filtration rate was positively correlated with that of the recipient throughout 3 years of observation. The results of this study indicate that various factors associated with allograft donors may influence graft function.

  1. Multijet Background Estimation For SUSY Searches And Particle Flow Offline Reconstruction Using The ATLAS Detector At The LHC

    CERN Document Server

    AUTHOR|(SzGeCERN)731691

    This thesis describes the jet smearing method, a data-driven technique for estimating the multijet background to Supersymmetry (SUSY) searches using the ATLAS detector at the Large Hadron Collider (LHC). The final 2011 and 2012 “ATLAS jets, missing transverse energy and zero leptons analysis” searches for SUSY are also documented. These analyses used the full ATLAS 2011 4.7 fb^{-1} $\\sqrt{s}$ = 7 TeV and 2012 20.3 fb$^{-1}$ $\\sqrt{s}$ = 8 TeV data sets. No statistically significant excess was found in either of these analyses; therefore, 95% C.L. mass exclusion limits were set on the mSUGRA/CMSSM m$_{0}$-m$_{1/2}$ and $m_{\\tilde{q}}$-$m_{\\tilde{g}}$ mass planes, and the simplified squark-gluino-neutralino pMSSM model. The jet smearing method was used in these analyses to estimate the multijet distributions of the Signal, Validation and Control Regions and also to calculate the multijet background Transfer Factors. This thesis also describes the missing transverse energy (E$_{miss}^{T}$ ) performance studi...

  2. Renal Transplantation from Elderly Living Donors

    Directory of Open Access Journals (Sweden)

    Jacob A. Akoh

    2013-01-01

    Full Text Available Acceptance of elderly living kidney donors remains controversial due to the higher incidence of comorbidity and greater risk of postoperative complications. This is a review of publications in the English language between 2000 and 2013 about renal transplantation from elderly living donors to determine trends and effects of donation, and the outcomes of such transplantation. The last decade witnessed a 50% increase in living kidney donor transplants, with a disproportionate increase in donors >60 years. There is no accelerated loss of kidney function following donation, and the incidence of established renal failure (ERF and hypertension among donors is similar to that of the general population. The overall incidence of ERF in living donors is about 0.134 per 1000 years. Elderly donors require rigorous assessment and should have a predicted glomerular filtration rate of at least 37.5 mL/min/1.73 m2 at the age of 80. Though elderly donors had lower glomerular filtration rate before donation, proportionate decline after donation was similar in both young and elderly groups. The risks of delayed graft function, acute rejection, and graft failure in transplants from living donors >65 years are significantly higher than transplants from younger donors. A multicentred, long-term, and prospective database addressing the outcomes of kidneys from elderly living donors is recommended.

  3. Development of Organ-Specific Donor Risk Indices

    OpenAIRE

    Akkina, Sanjeev K.; Asrani, Sumeet K.; Peng, Yi; Stock, Peter; Kim, Ray; Israni, Ajay K.

    2012-01-01

    Due to the shortage of deceased donor organs, transplant centers accept organs from marginal deceased donors, including older donors. Organ-specific donor risk indices have been developed to predict graft survival using various combinations of donor and recipient characteristics. We will review the kidney donor risk index (KDRI) and liver donor risk index (LDRI) and compare and contrast their strengths, limitations, and potential uses. The Kidney Donor Risk Index has a potential role in devel...

  4. GENE FLOW BETWEEN RED RICE AND CULTIVATED RICE ESTIMATED BY MICROSATELLITE MARKERS FLUXO GÊNICO ENTRE ARROZ VERMELHO E ARROZ CULTIVADO ESTIMADO POR MEIO DE MARCADORES MICROSSATÉLITES

    Directory of Open Access Journals (Sweden)

    Francisco , Moura Neto

    2007-09-01

    Full Text Available

    The study aimed to evaluate the capacity of SSR markers to detect the gene flow between the red rice (RR and the cultivated rice (CR. SSR is currently used in plant genomic analysis due to the high information content, to be co-dominant, and based on the PCR reaction. The field experiment was organized in ten concentric circles, 5 m to 50 m apart from a central red rice plant, assumed as the pollen donor. One hundred twenty rice CR plants, cv. BR-Irga 409, were planted in the intersections of the concentric circles and the twelve radii. From 51 SSR markers, four were selected due to their capacity to detect the polymorphism between RR and CR, aiming to identify RR alleles in seeds produced by BR-Irga 409 plants. The maximum distance found for gene flow between RR and CR plants was 10 m from the RR plant. In theory, at 0.1% cross pollination rate, this distance can generate 4,710 hybrids between RR and CR. In the next generation, about 3,532 plants would produce exclusively rice grains with red color. The SSR markers were able to identify the gene flow between RR and CR; therefore, they can be useful to increase the precision of cross pollination rate estimates in rice, mainly if used with other methodologies (e.g., herbicide tolerant plants.

    KEY WORDS: Cross pollination; microsatellite markers; Oryza sativa.

    Este trabalho objetivou avaliar a capacidade de marcadores SSR em detectar a ocorrência de fluxo gênico entre o arroz vermelho (AV e o arroz cultivado (AC. Marcadores SSR são utilizados em análise genômica de plantas devido ao alto conteúdo informativo, serem co-dominantes e baseados na reação de PCR. O ensaio de campo foi realizado em dez círculos concêntricos de 5 m a 50 m de distância, a partir de uma planta AV central, que foi a fonte

  5. The 2011 El Hierro submarine eruption: estimation of erupted lava flow volume on the basis of helicopter thermal surveys

    Science.gov (United States)

    Hernández, P. A.; Calvari, S.; Calvo, D.; Marquez, A.; Padron, E.; Pérez, N.; Melian, G.; Padilla, G.; Barrancos, J.; Dionis, S.; Rodríguez, F.; Nolasco, D.; Hernández, I.

    2012-04-01

    been collected each time in order to compare the temperature distribution with the features observed on the sea surface. Calculation of lava flow volume and effusion rate from thermal images collected by helicopter surveys has been largely used during the last decade for monitoring effusive eruptions at Etna, Stromboli, Kilauea, and other volcanoes. In this study, lava flow volume is calculated on the basis of temperature difference between the seawater contained within the dark patch, and the temperature of the seawater surface away from the eruption. These values have to be considered as minimum values, because they do not take into account the volume of lava isolated from the seawater by a thick crust that did not contribute to seawater warming. To calculate the lava volume we have used the model proposed by Harris et al. (1998) for the portion of the lava flow field spreading below sea level. Preliminary results indicate that during the period of study, about 5Mm3 of magma have been needed to heat the observed surface heated sea water at the submarine eruption site.

  6. Estimates of evapotranspiration for riparian sites (Eucalyptus) in the Lower Murray -Darling Basin using ground validated sap flow and vegetation index scaling techniques

    Science.gov (United States)

    Doody, T.; Nagler, P. L.; Glenn, E. P.

    2014-12-01

    Water accounting is becoming critical globally, and balancing consumptive water demands with environmental water requirements is especially difficult in in arid and semi-arid regions. Within the Murray-Darling Basin (MDB) in Australia, riparian water use has not been assessed across broad scales. This study therefore aimed to apply and validate an existing U.S. riparian ecosystem evapotranspiration (ET) algorithm for the MDB river systems to assist water resource managers to quantify environmental water needs over wide ranges of niche conditions. Ground-based sap flow ET was correlated with remotely sensed predictions of ET, to provide a method to scale annual rates of water consumption by riparian vegetation over entire irrigation districts. Sap flux was measured at nine locations on the Murrumbidgee River between July 2011 and June 2012. Remotely sensed ET was calculated using a combination of local meteorological estimates of potential ET (ETo) and rainfall and MODIS Enhanced Vegetation Index (EVI) from selected 250 m resolution pixels. The sap flow data correlated well with MODIS EVI. Sap flow ranged from 0.81 mm/day to 3.60 mm/day and corresponded to a MODIS-based ET range of 1.43 mm/day to 2.42 mm/day. We found that mean ET across sites could be predicted by EVI-ETo methods with a standard error of about 20% across sites, but that ET at any given site could vary much more due to differences in aquifer and soil properties among sites. Water use was within range of that expected. We conclude that our algorithm developed for US arid land crops and riparian plants is applicable to this region of Australia. Future work includes the development of an adjusted algorithm using these sap flow validated results.

  7. Geothermal properties and groundwater flow estimated with a three-dimensional geological model in a late Pleistocene terrace area, central Japan

    Science.gov (United States)

    Funabiki, A.; Takemura, T.; Hamamoto, S.; Komatsu, T.

    2012-12-01

    1. Introduction The ground source heat pump (GSHP) is a highly efficient and renewable energy technology for space heating and cooling, with benefits that include energy conservation and reductions in greenhouse gas emissions. One result of the huge Tohoku-oki earthquake and tsunami and the subsequent nuclear disasters is that GSHPs are receiving more attention from the media and they are being introduced by some local governments. Heat generated by underground GSHP installation, however, can pollute the geothermal environment or change groundwater flow patterns . In this study, we estimated possible effects from the use of GSHPs in the Tokyo area with a three-dimensional (3D) geological model. 2. Geological model The Tokyo Metropol