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Sample records for lung density measurements

  1. Lung density

    DEFF Research Database (Denmark)

    Garnett, E S; Webber, C E; Coates, G

    1977-01-01

    The density of a defined volume of the human lung can be measured in vivo by a new noninvasive technique. A beam of gamma-rays is directed at the lung and, by measuring the scattered gamma-rays, lung density is calculated. The density in the lower lobe of the right lung in normal man during quiet...... breathing in the sitting position ranged from 0.25 to 0.37 g.cm-3. Subnormal values were found in patients with emphsema. In patients with pulmonary congestion and edema, lung density values ranged from 0.33 to 0.93 g.cm-3. The lung density measurement correlated well with the findings in chest radiographs...... but the lung density values were more sensitive indices. This was particularly evident in serial observations of individual patients....

  2. Quantitative measurement of lung density with x-ray CT and positron CT, (2). Diseased subjects

    Energy Technology Data Exchange (ETDEWEB)

    Ito, Kengo; Ito, Masatoshi; Kubota, Kazuo

    1985-05-01

    Lung density was quantitatively measured on six diseased patients with X-ray CT (XCT) and Positron CT(PCT). The findings are as follows: In the silicosis, extravascular lung density was found to be remarkably increased compared to normals (0.29gcm/sup 3/), but blood volume was in normal range. In the post-irradiated lung cancers, extravascular lung density increased in the irradiated sites compared to the non-irradiated opposite sites, and blood volume varied in each case. In a patient with chronic heart failure, blood volume decreased (0.11mlcm/sup 3/) with increased extravascular lung density (0.23gcm/sup 3/). In the chronic obstructive pulmonary disease, both extravascular lung density and blood volume decreased (0.11gcm/sup 3/ and 0.10mlcm/sup 3/ respectively). Lung density measured with XCT was constantly lower than that with PCT in all cases. But changes in the values of lung density measured, correlated well with each other. In conclusion, the method presented here may clarify the etiology of the diffuse pulmonary diseases, and be used to differentiate and grade the diseases.

  3. Quantitative measurement of lung density with x-ray CT and positron CT, (2)

    International Nuclear Information System (INIS)

    Ito, Kengo; Ito, Masatoshi; Kubota, Kazuo

    1985-01-01

    Lung density was quantitatively measured on six diseased patients with X-ray CT (XCT) and Positron CT(PCT). The findings are as follows: In the silicosis, extravascular lung density was found to be remarkably increased compared to normals (0.29gcm -3 ), but blood volume was in normal range. In the post-irradiated lung cancers, extravascular lung density increased in the irradiated sites compared to the non-irradiated opposite sites, and blood volume varied in each case. In a patient with chronic heart failure, blood volume decreased (0.11mlcm -3 ) with increased extravascular lung density (0.23gcm -3 ). In the chronic obstructive pulmonary disease, both extravascular lung density and blood volume decreased (0.11gcm -3 and 0.10mlcm -3 respectively). Lung density measured with XCT was constantly lower than that with PCT in all cases. But changes in the values of lung density measured, correlated well with each other. In conclusion, the method presented here may clarify the etiology of the diffuse pulmonary diseases, and be used to differentiate and grade the diseases. (author)

  4. Indirect measurement of lung density and air volume from electrical impedance tomography (EIT) data.

    Science.gov (United States)

    Nebuya, Satoru; Mills, Gary H; Milnes, Peter; Brown, Brian H

    2011-12-01

    This paper describes a method for estimating lung density, air volume and changes in fluid content from a non-invasive measurement of the electrical resistivity of the lungs. Resistivity in Ω m was found by fitting measured electrical impedance tomography (EIT) data to a finite difference model of the thorax. Lung density was determined by comparing the resistivity of the lungs, measured at a relatively high frequency, with values predicted from a published model of lung structure. Lung air volume can then be calculated if total lung weight is also known. Temporal changes in lung fluid content will produce proportional changes in lung density. The method was implemented on EIT data, collected using eight electrodes placed in a single plane around the thorax, from 46 adult male subjects and 36 adult female subjects. Mean lung densities (±SD) of 246 ± 67 and 239 ± 64 kg m(-3), respectively, were obtained. In seven adult male subjects estimates of 1.68 ± 0.30, 3.42 ± 0.49 and 4.40 ± 0.53 l in residual volume, functional residual capacity and vital capacity, respectively, were obtained. Sources of error are discussed. It is concluded that absolute differences in lung density of about 30% and changes over time of less than 30% should be detected using the current technology in normal subjects. These changes would result from approximately 300 ml increase in lung fluid. The method proposed could be used for non-invasive monitoring of total lung air and fluid content in normal subjects but needs to be assessed in patients with lung disease.

  5. Interobserver variability in visual evaluation of thoracic CT scans and comparison with automatic computer measurements of CT lung density

    DEFF Research Database (Denmark)

    Winkler Wille, Mathilde Marie; Thomsen, Laura Hohwü; Dirksen, Asger

    2012-01-01

    lung density measurements, i.e. densitometry. Methods – In a pilot study 60 CT scans were selected from a sample of 3980 CT scans from The Danish Lung Cancer Screening Trial (DLCST). The amount of emphysema in these scans was scored independently by two observers, who were blinded regarding clinical...... information. The lung was segmented automatically by in-house developed computer software, and the percentage of pixels below -950 HU was used as a surrogate marker for emphysema. The observer variability, as well as the correlation with the lung density measurements, was analysed using Spearman’s rank...... in emphysema grading. However, the agreement with the CT lung density measurement was poor, indicating that the two types of evaluation represent different aspects of emphysema. Most likely, they should be seen as complementary rather than competitive evaluations. Future comparison with physiological tests...

  6. Measurement of lung density in congestive heart failure by computed tomography

    International Nuclear Information System (INIS)

    Nomura, Masanori; Miyagi, Yutaka; Tachi, Keiji; Sakabe, Yoshiyuki; Sakai, Yasuhiko; Hishida, Hitoshi; Mizuno, Yasushi; Sasaki, Fumio; Koga, Sukehiko

    1984-01-01

    The computed tomography (CT) number within the region of interest (ROI) was used as a parameter to assess lung density in patients with congestive heart failure. Thirty-eight patients with valvular heart disease (VHD) and 34 patients with ischemic heart disease (IHD) were studied. Based on the New York Heart Association (NYHA) classification, 24 VHD patients were in class I or II (VHD I-II) and the other 14 were in NYHA class III or IV (VHD III-IV). Eighteen patients with IHD were in NYHA class I or II (IHD I-II) and 16 were in class III or IV (IHD III-IV). The CT number was measured bilaterally at the upper, middle and lower levels of the chest and compared with the corresponding value in 21 normal subjects (Group N). In a preliminary study on Group N, the CT numbers were insensitive to the size of the ROI, but were closely related to its location. In clinical applications, the mean values of the CT numbers in all six lung fields increased in the order of IHD I-II, to VHD I-II, IHD III-IV and VHD III-IV. Except for patients in IHD I-II, they were significantly larger than in Group N. The relationship between the CT number and the systolic and mean pulmonary arterial pressures and the pulmonary capillary wedge pressure were evaluated in 36 patients. Significant correlations were obtained in all six lung fields (r=0.65-0.78, p<0.001). The results suggest that measurement of lung density by CT is useful for the quantitative evaluation of the severity of disease in patients with congestive heart failure. (author)

  7. Measurement of lung density in congestive heart failure by computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Nomura, Masanori; Miyagi, Yutaka; Tachi, Keiji; Sakabe, Yoshiyuki; Sakai, Yasuhiko; Hishida, Hitoshi; Mizuno, Yasushi; Sasaki, Fumio; Koga, Sukehiko [Fujita-Gakuen Health Univ., Toyoake, Aichi (Japan)

    1984-11-01

    The computed tomography (CT) number within the region of interest (ROI) was used as a parameter to assess lung density in patients with congestive heart failure. Thirty-eight patients with valvular heart disease (VHD) and 34 patients with ischemic heart disease (IHD) were studied. Based on the New York Heart Association (NYHA) classification, 24 VHD patients were in class I or II (VHD I-II) and the other 14 were in NYHA class III or IV (VHD III-IV). Eighteen patients with IHD were in NYHA class I or II (IHD I-II) and 16 were in class III or IV (IHD III-IV). The CT number was measured bilaterally at the upper, middle and lower levels of the chest and compared with the corresponding value in 21 normal subjects (Group N). In a preliminary study on Group N, the CT numbers were insensitive to the size of the ROI, but were closely related to its location. In clinical applications, the mean values of the CT numbers in all six lung fields increased in the order of IHD I-II, to VHD I-II, IHD III-IV and VHD III-IV. Except for patients in IHD I-II, they were significantly larger than in Group N. The relationship between the CT number and the systolic and mean pulmonary arterial pressures and the pulmonary capillary wedge pressure were evaluated in 36 patients. Significant correlations were obtained in all six lung fields (r=0.65-0.78, p < 0.001). The results suggest that measurement of lung density by CT is useful for the quantitative evaluation of the severity of disease in patients with congestive heart failure.

  8. Influences of lung parenchyma density and thoracic fluid on ventilatory EIT measurements

    NARCIS (Netherlands)

    Kunst, P. W.; Vonk Noordegraaf, A.; Straver, B.; Aarts, R. A.; Tesselaar, C. D.; Postmus, P. E.; de Vries, P. M.

    1998-01-01

    Ventilatory impedance changes can be measured by electrical impedance tomography (EIT). Several studies have pointed out that the ventilatory-induced impedance change measured over the lungs shows a linear relationship with tidal volume. However, EIT measures the ventilatory impedance changes

  9. Measurement of regional extravascular lung density and of pulmonary blood volume with positron emitting isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Larock, M.P.; Quaglia, L.; Lamotte, D.; De Landsheere, C.; Del Fiore, G.; Chevigne, M.; Peters, J.M.; Rigo, P. (Universite de Liege (Belgium))

    1982-01-01

    Studies of pulmonary blood volume changes with exercise can be performed after labelling of the blood pool by /sup 11/CO inhalation. Positron transaxial tomography permits the quantitative study of density distribution of the chest and of the pulmonary blood volume. This paper represents our preliminary experience with these techniques on models and control patients. We have first verified the linearity of transmission for density distribution below one. The tomographic examination first records a transmission image, then an emission image on the same section. We next normalize emission and transmission values on a region of unit density corresponding to blood: then we substract the emission from the transmission values to measure the extravascular pulmonary density. With crystal probes we record pulmonary blood volume variations before, during and after exercise. Peripheral hemodynamic variations explain the change recorded at the begining and at the end of exercise. Combination of these two techniques should help us to better study the importance of the acute changes in the ''formation'' of pulmonary oedema and its influence on regional pulmonary blood volume.

  10. Increased mean lung density: Another independent predictor of lung cancer?

    Energy Technology Data Exchange (ETDEWEB)

    Sverzellati, Nicola, E-mail: nicola.sverzellati@unipr.it [Department of Department of Surgical Sciences, Section of Diagnostic Imaging, University of Parma, Padiglione Barbieri, University Hospital of Parma, V. Gramsci 14, 43100 Parma (Italy); Randi, Giorgia, E-mail: giorgia.randi@marionegri.it [Department of Epidemiology, Mario Negri Institute, Via La Masa 19, 20156 Milan (Italy); Spagnolo, Paolo, E-mail: paolo.spagnolo@unimore.it [Respiratory Disease Unit, Center for Rare Lung Disease, Department of Oncology, Hematology and Respiratory Disease, University of Modena and Reggio Emilia, Via del Pozzo 71, 44124 Modena (Italy); Marchianò, Alfonso, E-mail: alfonso.marchiano@istitutotumori.mi.it [Department of Radiology, Fondazione IRCCS Istituto Nazionale dei Tumori, Via Venezian 1, 20133 Milan (Italy); Silva, Mario, E-mail: mac.mario@hotmail.it [Department of Department of Surgical Sciences, Section of Diagnostic Imaging, University of Parma, Padiglione Barbieri, University Hospital of Parma, V. Gramsci 14, 43100 Parma (Italy); Kuhnigk, Jan-Martin, E-mail: Jan-Martin.Kuhnigk@mevis.fraunhofer.de [Fraunhofer MEVIS, Universitaetsallee 29, 28359 Bremen (Germany); La Vecchia, Carlo, E-mail: carlo.lavecchia@marionegri.it [Department of Occupational Health, University of Milan, Via Venezian 1, 20133 Milan (Italy); Zompatori, Maurizio, E-mail: maurizio.zompatori@unibo.it [Department of Radiology, Cardio-Thoracic Section, S. Orsola-Malpighi Hospital, Via Albertoni 15, 40138 Bologna (Italy); Pastorino, Ugo, E-mail: ugo.pastorino@istitutotumori.mi.it [Department of Surgery, Section of Thoracic Surgery, Fondazione IRCCS Istituto Nazionale dei Tumori, Via Venezian 1, 20133 Milan (Italy)

    2013-08-15

    Objectives: To investigate the relationship between emphysema phenotype, mean lung density (MLD), lung function and lung cancer by using an automated multiple feature analysis tool on thin-section computed tomography (CT) data. Methods: Both emphysema phenotype and MLD evaluated by automated quantitative CT analysis were compared between outpatients and screening participants with lung cancer (n = 119) and controls (n = 989). Emphysema phenotype was defined by assessing features such as extent, distribution on core/peel of the lung and hole size. Adjusted multiple logistic regression models were used to evaluate independent associations of CT densitometric measurements and pulmonary function test (PFT) with lung cancer risk. Results: No emphysema feature was associated with lung cancer. Lung cancer risk increased with decreasing values of forced expiratory volume in 1 s (FEV{sub 1}) independently of MLD (OR 5.37, 95% CI: 2.63–10.97 for FEV{sub 1} < 60% vs. FEV{sub 1} ≥ 90%), and with increasing MLD independently of FEV{sub 1} (OR 3.00, 95% CI: 1.60–5.63 for MLD > −823 vs. MLD < −857 Hounsfield units). Conclusion: Emphysema per se was not associated with lung cancer whereas decreased FEV{sub 1} was confirmed as being a strong and independent risk factor. The cross-sectional association between increased MLD and lung cancer requires future validations.

  11. Factors influencing the decline in lung density in a Danish lung cancer screening cohort

    DEFF Research Database (Denmark)

    Shaker, Saher B.; Dirksen, Asger; Lo, Pechin Chien Pau

    2012-01-01

    Lung cancer screening trials provide an opportunity to study the natural history of emphysema by using CT lung density as a surrogate parameter.In the Danish Lung Cancer Screening Trial, 2,052 participants were included. At screening rounds, smoking habits were recorded and spirometry was performed....... CT lung density was measured as the volume-adjusted 15th percentile density (PD15). A mixed effects model was used with former smoking males with...

  12. Short-term Reproducibility of Computed Tomography-based Lung Density Measurements in Alpha-1 Antitrypsin Deficiency and Smokers with Emphysema

    International Nuclear Information System (INIS)

    Shaker, S.B.; Dirksen, A.; Laursen, L.C.; Maltbaek, N.; Christensen, L.; Sander, U.; Seersholm, N.; Skovgaard, L.T.; Nielsen, L.; Kok-Jensen, A.

    2004-01-01

    Purpose: To study the short-term reproducibility of lung density measurements by multi-slice computed tomography (CT) using three different radiation doses and three reconstruction algorithms. Material and Methods: Twenty-five patients with smoker's emphysema and 25 patients with 1-antitrypsin deficiency underwent 3 scans at 2-week intervals. Low-dose protocol was applied, and images were reconstructed with bone, detail, and soft algorithms. Total lung volume (TLV), 15th percentile density (PD-15), and relative area at -910 Hounsfield units (RA-910) were obtained from the images using Pulmo-CMS software. Reproducibility of PD-15 and RA-910 and the influence of radiation dose, reconstruction algorithm, and type of emphysema were then analysed. Results: The overall coefficient of variation of volume adjusted PD-15 for all combinations of radiation dose and reconstruction algorithm was 3.7%. The overall standard deviation of volume-adjusted RA-910 was 1.7% (corresponding to a coefficient of variation of 6.8%). Radiation dose, reconstruction algorithm, and type of emphysema had no significant influence on the reproducibility of PD-15 and RA-910. However, bone algorithm and very low radiation dose result in overestimation of the extent of emphysema. Conclusion: Lung density measurement by CT is a sensitive marker for quantitating both subtypes of emphysema. A CT-protocol with radiation dose down to 16 mAs and soft or detail reconstruction algorithm is recommended

  13. Asynchrony in respiratory movements between the pulmonary lobes in patients with COPD: continuous measurement of lung density by 4-dimensional dynamic-ventilation CT

    Directory of Open Access Journals (Sweden)

    Yamashiro T

    2017-07-01

    Full Text Available Tsuneo Yamashiro,1 Hiroshi Moriya,2 Shin Matsuoka,3 Yukihiro Nagatani,4 Maho Tsubakimoto,1 Nanae Tsuchiya,1 Sadayuki Murayama1 On behalf of the ACTIve Study Group 1Department of Radiology, Graduate School of Medical Science, University of the Ryukyus, Nishihara, Okinawa, Japan; 2Department of Radiology, Ohara General Hospital, Fukushima-City, Fukushima, Japan; 3Department of Radiology, St Marianna University School of Medicine, Kawasaki, Kanagawa, Japan; 4Department of Radiology, Shiga University of Medical Science, Otsu, Shiga, Japan Purpose: Four-dimensional dynamic-ventilation CT imaging demonstrates continuous movement of the lung. The aim of this study was to assess the correlation between interlobar synchrony in lung density and spirometric values in COPD patients and smokers, by measuring the continuous changes in lung density during respiration on the dynamic-ventilation CT. Materials and methods: Thirty-two smokers, including ten with COPD, underwent dynamic-ventilation CT during free breathing. CT data were continuously reconstructed every 0.5 sec. Mean lung density (MLD of the five lobes (right upper [RU], right middle [RM], right lower [RL], left upper [LU], and left lower [LL] was continuously measured by commercially available software using a fixed volume of volume of interest which was placed and tracked on a single designated point in each lobe. Concordance between the MLD time curves of six pairs of lung lobes (RU-RL, RU-RM, RM-RL, LU-LL, RU-LU, and RL-LL lobes was expressed by cross-correlation coefficients. The relationship between these cross-correlation coefficients and the forced expiratory volume in one second/forced vital capacity (FEV1.0/FVC values was assessed by Spearman rank correlation analysis. Results: In all six pairs of the pulmonary lobes, the cross-correlation coefficients of the two MLD curves were significantly positively correlated with FEV1.0/FVC (ρ =0.60–0.73, P<0.001. The mean value of the six

  14. Measurement of true density

    International Nuclear Information System (INIS)

    Carr-Brion, K.G.; Keen, E.F.

    1982-01-01

    System for determining the true density of a fluent mixture such as a liquid slurry, containing entrained gas, such as air comprises a restriction in pipe through which at least a part of the mixture is passed. Density measuring means such as gamma-ray detectors and source measure the apparent density of the mixture before and after its passage through the restriction. Solid-state pressure measuring devices are arranged to measure the pressure in the mixture before and after its passage through the restriction. Calculating means, such as a programmed microprocessor, determine the true density from these measurements using relationships given in the description. (author)

  15. Lung density: clinical method for quantitation of pulmonary congestion and edema

    Energy Technology Data Exchange (ETDEWEB)

    Garnett, E S; Webber, C E; Coates, G; Cockshott, W P; Nahmias, C; Lassen, N [McMaster Univ., Hamilton, Ontario (Canada); Bispebjerg Hospital, Copenhagen (Denmark))

    1977-01-22

    The density of a defined volume of the human lung can be measured in vivo by a new noninvasive technique. A beam of ..gamma..-rays is directed at the lung and, by measuring the scattered ..gamma..-rays, lung density is calculated.

  16. Hazy increased density in diffuse lung disease

    International Nuclear Information System (INIS)

    Klein, J.S.; Webb, W.R.; Gamsu, G.; Warnock, M.; Park, C.K.

    1989-01-01

    In order to determine the significance of ground glass density on high-resolution CT scans of patients with idiopathic pulmonary fibrosis and other lung disorders, the authors have reviewed 200 high-resolution CT studies and found 50 cases demonstrating areas of hazy increased lung density. Disease entities most often associated with this finding included DIP, UIP, alveolar proteinosis, sarcoidosis, and bronchiolitis obliterans/ organizing pneumonia. Pathologic examination revealed either cellular or fluid material lining terminal air spaces, often associated with alveolar wall infiltration and an absence of fibrosis. Gallium scans and bronchoalveolar lavage in some cases showed active inflammation Follow-up high-resolution CT studies in 10 patients showed either change or resolution of the hazy densities, confirming the presence of a reversible parenchymal lesion

  17. Quantitative computed tomography of lung parenchyma in patients with emphysema: analysis of higher-density lung regions

    Science.gov (United States)

    Lederman, Dror; Leader, Joseph K.; Zheng, Bin; Sciurba, Frank C.; Tan, Jun; Gur, David

    2011-03-01

    Quantitative computed tomography (CT) has been widely used to detect and evaluate the presence (or absence) of emphysema applying the density masks at specific thresholds, e.g., -910 or -950 Hounsfield Unit (HU). However, it has also been observed that subjects with similar density-mask based emphysema scores could have varying lung function, possibly indicating differences of disease severity. To assess this possible discrepancy, we investigated whether density distribution of "viable" lung parenchyma regions with pixel values > -910 HU correlates with lung function. A dataset of 38 subjects, who underwent both pulmonary function testing and CT examinations in a COPD SCCOR study, was assembled. After the lung regions depicted on CT images were automatically segmented by a computerized scheme, we systematically divided the lung parenchyma into different density groups (bins) and computed a number of statistical features (i.e., mean, standard deviation (STD), skewness of the pixel value distributions) in these density bins. We then analyzed the correlations between each feature and lung function. The correlation between diffusion lung capacity (DLCO) and STD of pixel values in the bin of -910HU lung parenchyma and lung function, which indicates that similar to the conventional density mask method, the pixel value distribution features in "viable" lung parenchyma areas may also provide clinically useful information to improve assessments of lung disease severity as measured by lung functional tests.

  18. Intra-observer and inter-observer agreements for the measurement of dual-input whole tumor computed tomography perfusion in patients with lung cancer: Influences of the size and inner-air density of tumors.

    Science.gov (United States)

    Wang, Qingle; Zhang, Zhiyong; Shan, Fei; Shi, Yuxin; Xing, Wei; Shi, Liangrong; Zhang, Xingwei

    2017-09-01

    This study was conducted to assess intra-observer and inter-observer agreements for the measurement of dual-input whole tumor computed tomography perfusion (DCTP) in patients with lung cancer. A total of 88 patients who had undergone DCTP, which had proved a diagnosis of primary lung cancer, were divided into two groups: (i) nodules (diameter ≤3 cm) and masses (diameter >3 cm) by size, and (ii) tumors with and without air density. Pulmonary flow, bronchial flow, and pulmonary index were measured in each group. Intra-observer and inter-observer agreements for measurement were assessed using intraclass correlation coefficient, within-subject coefficient of variation, and Bland-Altman analysis. In all lung cancers, the reproducibility coefficient for intra-observer agreement (range 26.1-38.3%) was superior to inter-observer agreement (range 38.1-81.2%). Further analysis revealed lower agreements for nodules compared to masses. Additionally, inner-air density reduced both agreements for lung cancer. The intra-observer agreement for measuring lung cancer DCTP was satisfied, while the inter-observer agreement was limited. The effects of tumoral size and inner-air density to agreements, especially between two observers, should be emphasized. In future, an automatic computer-aided segment of perfusion value of the tumor should be developed. © 2017 The Authors. Thoracic Cancer published by China Lung Oncology Group and John Wiley & Sons Australia, Ltd.

  19. Rapid fall in lung density following smoking cessation in COPD

    DEFF Research Database (Denmark)

    Shaker, Saher B; Stavngaard, Trine; Laursen, Lars Christian

    2011-01-01

    Whether smoking-induced lung inflammation subsides after smoking cessation is currently a matter of debate. We used computed tomography (CT) to evaluate the effect of smoking cessation on lung density in patients with COPD....

  20. Rapid fall in lung density following smoking cessation in COPD

    DEFF Research Database (Denmark)

    Shaker, Saher B; Stavngaard, Trine; Laursen, Lars Christian

    2011-01-01

    Whether smoking-induced lung inflammation subsides after smoking cessation is currently a matter of debate. We used computed tomography (CT) to evaluate the effect of smoking cessation on lung density in patients with COPD.......Whether smoking-induced lung inflammation subsides after smoking cessation is currently a matter of debate. We used computed tomography (CT) to evaluate the effect of smoking cessation on lung density in patients with COPD....

  1. Density measures and additive property

    OpenAIRE

    Kunisada, Ryoichi

    2015-01-01

    We deal with finitely additive measures defined on all subsets of natural numbers which extend the asymptotic density (density measures). We consider a class of density measures which are constructed from free ultrafilters on natural numbers and study a certain additivity property of such density measures.

  2. Factors influencing the decline in lung density in a Danish lung cancer screening cohort.

    Science.gov (United States)

    Shaker, Saher B; Dirksen, Asger; Lo, Pechin; Skovgaard, Lene T; de Bruijne, Marleen; Pedersen, Jesper H

    2012-11-01

    Lung cancer screening trials provide an opportunity to study the natural history of emphysema by using computed tomography (CT) lung density as a surrogate parameter. In the Danish Lung Cancer Screening Trial, 2,052 participants were included. At screening rounds, smoking habits were recorded and spirometry was performed. CT lung density was measured as the volume-adjusted 15th percentile density (PD15). A mixed effects model was used with former smoking males with <30 pack-yrs and without airflow obstruction (AFO) at entry as a reference group. At study entry, 893 (44%) participants had AFO. For the reference group, PD15 was 72.6 g·L(-1) with an annual decline of -0.33 g·L(-1). Female sex and current smoking increased PD15 at baseline, 17.3 g·L(-1) (p<0.001) and 10 g·L(-1) (p<0.001), respectively; and both increased the annual decline in PD15 (female: -0.3 g·L(-1); current smoking: -0.4 g·L(-1)). The presence and severity of AFO was a strong predictor of low PD15 at baseline (Global Initiative for Chronic Obstructive Lung Disease (GOLD) I: -1.4 g·L(-1); GOLD II: -6.3 g·L(-1); GOLD III: -17 g·L(-1)) and of increased annual decline in PD15 (GOLD I: -0.2 g·L(-1); GOLD II: -0.5 g·L(-1); GOLD III: -0.5 g·L(-1)). Female sex, active smoking and the presence of AFO are associated with accelerated decline in lung density.

  3. Intravenous augmentation treatment and lung density in severe α1 antitrypsin deficiency (RAPID)

    DEFF Research Database (Denmark)

    Chapman, Kenneth R; Burdon, Jonathan G W; Piitulainen, Eeva

    2015-01-01

    BACKGROUND: The efficacy of α1 proteinase inhibitor (A1PI) augmentation treatment for α1 antitrypsin deficiency has not been substantiated by a randomised, placebo-controlled trial. CT-measured lung density is a more sensitive measure of disease progression in α1 antitrypsin deficiency emphysema...... of emphysema, a finding that could not be substantiated by lung density measurement at FRC alone or by the two measurements combined. These findings should prompt consideration of augmentation treatment to preserve lung parenchyma in individuals with emphysema secondary to severe α1 antitrypsin deficiency...

  4. Factors influencing the decline in lung density in a Danish lung cancer screening cohort

    NARCIS (Netherlands)

    S.B. Shaker (Saher); A. Dirksen (Asger); P. Lo (Pechin); L.T. Skovgaard (Lene); M. de Bruijne (Marleen); J.H. Pedersen (Jerry)

    2012-01-01

    textabstractLung cancer screening trials provide an opportunity to study the natural history of emphysema by using computed tomography (CT) lung density as a surrogate parameter. In the Danish Lung Cancer Screening Trial, 2,052 participants were included. At screening rounds, smoking habits were

  5. Measurement of loose powder density

    International Nuclear Information System (INIS)

    Akhtar, S.; Ali, A.; Haider, A.; Farooque, M.

    2011-01-01

    Powder metallurgy is a conventional technique for making engineering articles from powders. Main objective is to produce final products with the highest possible uniform density, which depends on the initial loose powder characteristics. Producing, handling, characterizing and compacting materials in loose powder form are part of the manufacturing processes. Density of loose metallic or ceramic powder is an important parameter for die design. Loose powder density is required for calculating the exact mass of powder to fill the die cavity for producing intended green density of the powder compact. To fulfill this requirement of powder metallurgical processing, a loose powder density meter as per ASTM standards is designed and fabricated for measurement of density. The density of free flowing metallic powders can be determined using Hall flow meter funnel and density cup of 25 cm/sup 3/ volume. Density of metal powders like cobalt, manganese, spherical bronze and pure iron is measured and results are obtained with 99.9% accuracy. (author)

  6. Association Between RT-Induced Changes in Lung Tissue Density and Global Lung Function

    International Nuclear Information System (INIS)

    Ma Jinli; Zhang Junan; Zhou Sumin; Hubbs, Jessica L.; Foltz, Rodney J.; Hollis, Donna R.; Light, Kim L.; Wong, Terence Z.; Kelsey, Christopher R.; Marks, Lawrence B.

    2009-01-01

    Purpose: To assess the association between radiotherapy (RT)-induced changes in computed tomography (CT)-defined lung tissue density and pulmonary function tests (PFTs). Methods and Materials: Patients undergoing incidental partial lung RT were prospectively assessed for global (PFTs) and regional (CT and single photon emission CT [SPECT]) lung function before and, serially, after RT. The percent reductions in the PFT and the average changes in lung density were compared (Pearson correlations) in the overall group and subgroups stratified according to various clinical factors. Comparisons were also made between the CT- and SPECT-based computations using the Mann-Whitney U test. Results: Between 1991 and 2004, 343 patients were enrolled in this study. Of these, 111 patients had a total of 203 concurrent post-RT evaluations of changes in lung density and PFTs available for the analyses, and 81 patients had a total of 141 concurrent post-RT SPECT images. The average increases in lung density were related to the percent reductions in the PFTs, albeit with modest correlation coefficients (range, 0.20-0.43). The analyses also indicated that the association between lung density and PFT changes is essentially equivalent to the corresponding association with SPECT-defined lung perfusion. Conclusion: We found a weak quantitative association between the degree of increase in lung density as defined by CT and the percent reduction in the PFTs.

  7. Rapid fall in lung density following smoking cessation in COPD.

    Science.gov (United States)

    Shaker, Saher B; Stavngaard, Trine; Laursen, Lars Christian; Stoel, Berend C; Dirksen, Asger

    2011-02-01

    Whether smoking-induced lung inflammation subsides after smoking cessation is currently a matter of debate. We used computed tomography (CT) to evaluate the effect of smoking cessation on lung density in patients with COPD. Thirty-six patients quit smoking out of 254 current smokers with COPD who were followed with annual CT and lung function tests (LFT) for 2?4 years as part of a randomised placebo-controlled trial of the effect of inhaled budesonide on CT-lung density. Lung density was expressed as the 15th percentile density (PD15) and relative area of emphysema below -910 HU (RA-910). From the time-trends in the budesonide and placebo groups the expected CT-lung densities at the first visit after smoking cessation were calculated by linear regression and compared to the observed densities. Following smoking cessation RA-910 increased by 2.6% (p = 0.003) and PD15 decreased by -4.9 HU (p = 0.0002). Furthermore, changes were larger in the budesonide group than the placebo group (PD15: -7.1 vs -2.8 HU. RA-910 3.7% vs 1.7%). These differences were, however, not statistically significant. The LFT parameters (FEV(1) and diffusion capacity) were not significantly influenced by smoking cessation. Inflammation partly masks the presence of emphysema on CT and smoking cessation results in a paradoxical fall in lung density, which resembles rapid progression of emphysema. This fall in density is probably due to an anti-inflammatory effect of smoking cessation.

  8. Measuring single-cell density.

    Science.gov (United States)

    Grover, William H; Bryan, Andrea K; Diez-Silva, Monica; Suresh, Subra; Higgins, John M; Manalis, Scott R

    2011-07-05

    We have used a microfluidic mass sensor to measure the density of single living cells. By weighing each cell in two fluids of different densities, our technique measures the single-cell mass, volume, and density of approximately 500 cells per hour with a density precision of 0.001 g mL(-1). We observe that the intrinsic cell-to-cell variation in density is nearly 100-fold smaller than the mass or volume variation. As a result, we can measure changes in cell density indicative of cellular processes that would be otherwise undetectable by mass or volume measurements. Here, we demonstrate this with four examples: identifying Plasmodium falciparum malaria-infected erythrocytes in a culture, distinguishing transfused blood cells from a patient's own blood, identifying irreversibly sickled cells in a sickle cell patient, and identifying leukemia cells in the early stages of responding to a drug treatment. These demonstrations suggest that the ability to measure single-cell density will provide valuable insights into cell state for a wide range of biological processes.

  9. Feasibility of using 'lung density' values estimated from EIT images for clinical diagnosis of lung abnormalities in mechanically ventilated ICU patients.

    Science.gov (United States)

    Nebuya, Satoru; Koike, Tomotaka; Imai, Hiroshi; Iwashita, Yoshiaki; Brown, Brian H; Soma, Kazui

    2015-06-01

    This paper reports on the results of a study which compares lung density values obtained from electrical impedance tomography (EIT), clinical diagnosis and CT values (HU) within a region of interest in the lung. The purpose was to assess the clinical use of lung density estimation using EIT data. In 11 patients supported by a mechanical ventilator, the consistency of regional lung density measurements as estimated by EIT was validated to assess the feasibility of its use in intensive care medicine. There were significant differences in regional lung densities recorded in the supine position between normal lungs and diseased lungs associated with pneumonia, atelectasis and pleural effusion (normal; 240 ± 71.7 kg m(-3), pneumonia; 306 ± 38.6 kg m(-3), atelectasis; 497 ± 130 kg m(-3), pleural effusion; 467 ± 113 kg m(-3): Steel-Dwass test, p EIT images. The results of CT and EIT images from five patients in an intensive care unit showed a correlation coefficient of 0.66 ± 0.13 between the CT values (HU) and the lung density values (kg m(-3)) obtained from EIT. These results indicate that it may be possible to obtain a quantitative value for regional lung density using EIT.

  10. Accuracy of lung nodule density on HRCT: analysis by PSF-based image simulation.

    Science.gov (United States)

    Ohno, Ken; Ohkubo, Masaki; Marasinghe, Janaka C; Murao, Kohei; Matsumoto, Toru; Wada, Shinichi

    2012-11-08

    A computed tomography (CT) image simulation technique based on the point spread function (PSF) was applied to analyze the accuracy of CT-based clinical evaluations of lung nodule density. The PSF of the CT system was measured and used to perform the lung nodule image simulation. Then, the simulated image was resampled at intervals equal to the pixel size and the slice interval found in clinical high-resolution CT (HRCT) images. On those images, the nodule density was measured by placing a region of interest (ROI) commonly used for routine clinical practice, and comparing the measured value with the true value (a known density of object function used in the image simulation). It was quantitatively determined that the measured nodule density depended on the nodule diameter and the image reconstruction parameters (kernel and slice thickness). In addition, the measured density fluctuated, depending on the offset between the nodule center and the image voxel center. This fluctuation was reduced by decreasing the slice interval (i.e., with the use of overlapping reconstruction), leading to a stable density evaluation. Our proposed method of PSF-based image simulation accompanied with resampling enables a quantitative analysis of the accuracy of CT-based evaluations of lung nodule density. These results could potentially reveal clinical misreadings in diagnosis, and lead to more accurate and precise density evaluations. They would also be of value for determining the optimum scan and reconstruction parameters, such as image reconstruction kernels and slice thicknesses/intervals.

  11. CT analysis of lung density changes in patients undergoing total body irradiation prior to bone marrow transplantation

    International Nuclear Information System (INIS)

    Lee, J.Y.; Shank, B.; Bonfiglio, P.; Reid, A.

    1984-01-01

    Sequential changes in lung density measured by CT are potentially sensitive and convenient monitors of lung abnormalities following total body irradiation (TBI). Methods have been developed to compare pre- and post-TBI CT of lung. The average local features of a cross-sectional lung slice are extracted from three peripheral regions of interest in the anterior, posterior, and lateral portions of the CT image. Also, density profiles across a specific region may be obtained. These may be compared first for verification of patient position and breathing status and then for changes between pre- and post-TBI. These may also be compared with radiation dose profiles through the lung. A preliminary study on 21 leukemia patients undergoing total body irradiation indicates the following: (a) Density gradients of patients' lungs in the antero-posterior direction show a marked heterogeneity before and after transplantation compared with normal lungs. The patients with departures from normal density gradients pre-TBI correlate with later pulmonary complications. (b) Measurements of average peripheral lung densities have demonstrated that the average lung density in the younger age group is substantially higher: pre-TBI, the average CT number (1,000 scale) is -638 +/- 39 Hounsfield unit (HU) for 0-10 years old and -739 +/- 53 HU for 21-40 years old. (c) Density profiles showed no post-TBI regional changes in lung density corresponding to the dose profile across the lung, so no differentiation of a radiation-specific effect has yet been possible. Computed tomographic density profiles in the antero-posterior direction are successfully used to verify positioning of the CT slice and the breathing level of the lung

  12. Lung volumes: measurement, clinical use, and coding.

    Science.gov (United States)

    Flesch, Judd D; Dine, C Jessica

    2012-08-01

    Measurement of lung volumes is an integral part of complete pulmonary function testing. Some lung volumes can be measured during spirometry; however, measurement of the residual volume (RV), functional residual capacity (FRC), and total lung capacity (TLC) requires special techniques. FRC is typically measured by one of three methods. Body plethysmography uses Boyle's Law to determine lung volumes, whereas inert gas dilution and nitrogen washout use dilution properties of gases. After determination of FRC, expiratory reserve volume and inspiratory vital capacity are measured, which allows the calculation of the RV and TLC. Lung volumes are commonly used for the diagnosis of restriction. In obstructive lung disease, they are used to assess for hyperinflation. Changes in lung volumes can also be seen in a number of other clinical conditions. Reimbursement for measurement of lung volumes requires knowledge of current procedural terminology (CPT) codes, relevant indications, and an appropriate level of physician supervision. Because of recent efforts to eliminate payment inefficiencies, the 10 previous CPT codes for lung volumes, airway resistance, and diffusing capacity have been bundled into four new CPT codes.

  13. The association of systemic microvascular changes with lung function and lung density: a cross-sectional study.

    Directory of Open Access Journals (Sweden)

    Bianca Harris

    Full Text Available Smoking causes endothelial dysfunction and systemic microvascular disease with resultant end-organ damage in the kidneys, eyes and heart. Little is known about microvascular changes in smoking-related lung disease. We tested if microvascular changes in the retina, kidneys and heart were associated with obstructive spirometry and low lung density on computed tomography. The Multi-Ethnic Study of Atherosclerosis recruited participants age 45-84 years without clinical cardiovascular disease. Measures of microvascular function included retinal arteriolar and venular caliber, urine albumin-to-creatinine ratio and, in a subset, myocardial blood flow on magnetic resonance imaging. Spirometry was measured following ATS/ERS guidelines. Low attenuation areas (LAA were measured on lung fields of cardiac computed tomograms. Regression models adjusted for pulmonary and cardiac risk factors, medications and body size. Among 3,397 participants, retinal venular caliber was inversely associated with forced expiratory volume in one second (FEV(1 (P<0.001 and FEV(1/forced vital capacity (FVC ratio (P = 0.04. Albumin-to-creatinine ratio was inversely associated with FEV(1 (P = 0.002 but not FEV(1/FVC. Myocardial blood flow (n = 126 was associated with lower FEV(1 (P = 0.02, lower FEV(1/FVC (P = 0.001 and greater percentage LAA (P = 0.04. Associations were of greater magnitude among smokers. Low lung function was associated with microvascular changes in the retina, kidneys and heart, and low lung density was associated with impaired myocardial microvascular perfusion. These cross-sectional results suggest that microvascular damage with end-organ dysfunction in all circulations may pertain to the lung, that lung dysfunction may contribute to systemic microvascular disease, or that there may be a shared predisposition.

  14. Volume Adjustment of Lung Density by Computed Tomography Scans in Patients with Emphysema

    International Nuclear Information System (INIS)

    Shaker, S.B.; Dirksen, A.; Laursen, L.C.; Skovgaard, L.T.; Holstein-Rathlou, N.H.

    2004-01-01

    Purpose: To determine how to adjust lung density measurements for the volume of the lung calculated from computed tomography (CT) scans in patients with emphysema. Material and Methods: Fifty patients with emphysema underwent 3 CT scans at 2-week intervals. The scans were analyzed with a software package that detected the lung in contiguous images and subsequently generated a histogram of the pixel attenuation values. The total lung volume (TLV), lung weight, percentile density (PD), and relative area of emphysema (RA) were calculated from this histogram. RA and PD are commonly applied measures of pulmonary emphysema derived from CT scans. These parameters are markedly influenced by changes in the level of inspiration. The variability of lung density due to within-subject variation in TLV was explored by plotting TLV against PD and RA. Results: The coefficients for volume adjustment for PD were relatively stable over a wide range from the 10th to the 80th percentile, whereas for RA the coefficients showed large variability especially in the lower range, which is the most relevant for quantitation of pulmonary emphysema. Conclusion: Volume adjustment is mandatory in repeated CT densitometry and is more robust for PD than for RA. Therefore, PD seems more suitable for monitoring the progression of emphysema

  15. Method of measuring surface density

    International Nuclear Information System (INIS)

    Gregor, J.

    1982-01-01

    A method is described of measuring surface density or thickness, preferably of coating layers, using radiation emitted by a suitable radionuclide, e.g., 241 Am. The radiation impinges on the measured material, e.g., a copper foil and in dependence on its surface density or thickness part of the flux of impinging radiation is reflected and part penetrates through the material. The radiation which has penetrated through the material excites in a replaceable adjustable backing characteristic radiation of an energy close to that of the impinging radiation (within +-30 keV). Part of the flux of the characteristic radiation spreads back to the detector, penetrates through the material in which in dependence on surface density or thickness of the coating layer it is partly absorbed. The flux of the penetrated characteristic radiation impinging on the face of the detector is a function of surface density or thickness. Only that part of the energy is evaluated of the energy spectrum which corresponds to the energy of characteristic radiation. (B.S.)

  16. Volume adjustment of lung density by computed tomography scans in patients with emphysema

    DEFF Research Database (Denmark)

    Shaker, S B; Dirksen, A; Laursen, Lars Christian

    2004-01-01

    of pulmonary emphysema derived from CT scans. These parameters are markedly influenced by changes in the level of inspiration. The variability of lung density due to within-subject variation in TLV was explored by plotting TLV against PD and RA. RESULTS: The coefficients for volume adjustment for PD were...... relatively stable over a wide range from the 10th to the 80th percentile, whereas for RA the coefficients showed large variability especially in the lower range, which is the most relevant for quantitation of pulmonary emphysema. CONCLUSION: Volume adjustment is mandatory in repeated CT densitometry......PURPOSE: To determine how to adjust lung density measurements for the volume of the lung calculated from computed tomography (CT) scans in patients with emphysema. MATERIAL AND METHODS: Fifty patients with emphysema underwent 3 CT scans at 2-week intervals. The scans were analyzed with a software...

  17. Measurement of lung water with SPECT

    International Nuclear Information System (INIS)

    Chu, R.Y.L.; Ficken, V.J.; Ekeh, S.U.; Ryals, C.J.; Allen, E.W.; Basmadjian, G.

    1990-01-01

    This paper investigates the use of iodoantipyrine (IAP) labeled with radioactive iodine (I-123) and single photon emission tomography (SPECT) to measure lung water. I-123 IAP was injected intravenously to six New Zealand White rabbits under anesthesia. After 1 hour, Tc-99m macroaggregates of albumin (MAA) were injected. SPECT imaging was performed in dual-energy mode. After a blood sample was drawn, the animals were sacrificed, and the lungs were removed. Blood samples were assayed for radioactivity. The lungs were weighed, dried, and weighted again to determine water content. The product of area defined by MAA in a tomogram and IAP count rate of central pixels of that region in the corresponding tomogram was taken as the relative amount of IAP in each lung

  18. The effect of respiratory induced density variations on non-TOF PET quantitation in the lung

    Science.gov (United States)

    Holman, Beverley F.; Cuplov, Vesna; Hutton, Brian F.; Groves, Ashley M.; Thielemans, Kris

    2016-04-01

    Accurate PET quantitation requires a matched attenuation map. Obtaining matched CT attenuation maps in the thorax is difficult due to the respiratory cycle which causes both motion and density changes. Unlike with motion, little attention has been given to the effects of density changes in the lung on PET quantitation. This work aims to explore the extent of the errors caused by pulmonary density attenuation map mismatch on dynamic and static parameter estimates. Dynamic XCAT phantoms were utilised using clinically relevant 18F-FDG and 18F-FMISO time activity curves for all organs within the thorax to estimate the expected parameter errors. The simulations were then validated with PET data from 5 patients suffering from idiopathic pulmonary fibrosis who underwent PET/Cine-CT. The PET data were reconstructed with three gates obtained from the Cine-CT and the average Cine-CT. The lung TACs clearly displayed differences between true and measured curves with error depending on global activity distribution at the time of measurement. The density errors from using a mismatched attenuation map were found to have a considerable impact on PET quantitative accuracy. Maximum errors due to density mismatch were found to be as high as 25% in the XCAT simulation. Differences in patient derived kinetic parameter estimates and static concentration between the extreme gates were found to be as high as 31% and 14%, respectively. Overall our results show that respiratory associated density errors in the attenuation map affect quantitation throughout the lung, not just regions near boundaries. The extent of this error is dependent on the activity distribution in the thorax and hence on the tracer and time of acquisition. Consequently there may be a significant impact on estimated kinetic parameters throughout the lung.

  19. The effect of respiratory induced density variations on non-TOF PET quantitation in the lung

    International Nuclear Information System (INIS)

    Holman, Beverley F; Cuplov, Vesna; Hutton, Brian F; Groves, Ashley M; Thielemans, Kris

    2016-01-01

    Accurate PET quantitation requires a matched attenuation map. Obtaining matched CT attenuation maps in the thorax is difficult due to the respiratory cycle which causes both motion and density changes. Unlike with motion, little attention has been given to the effects of density changes in the lung on PET quantitation. This work aims to explore the extent of the errors caused by pulmonary density attenuation map mismatch on dynamic and static parameter estimates. Dynamic XCAT phantoms were utilised using clinically relevant 18 F-FDG and 18 F-FMISO time activity curves for all organs within the thorax to estimate the expected parameter errors. The simulations were then validated with PET data from 5 patients suffering from idiopathic pulmonary fibrosis who underwent PET/Cine-CT. The PET data were reconstructed with three gates obtained from the Cine-CT and the average Cine-CT. The lung TACs clearly displayed differences between true and measured curves with error depending on global activity distribution at the time of measurement. The density errors from using a mismatched attenuation map were found to have a considerable impact on PET quantitative accuracy. Maximum errors due to density mismatch were found to be as high as 25% in the XCAT simulation. Differences in patient derived kinetic parameter estimates and static concentration between the extreme gates were found to be as high as 31% and 14%, respectively. Overall our results show that respiratory associated density errors in the attenuation map affect quantitation throughout the lung, not just regions near boundaries. The extent of this error is dependent on the activity distribution in the thorax and hence on the tracer and time of acquisition. Consequently there may be a significant impact on estimated kinetic parameters throughout the lung. (paper)

  20. Two methods for isolating the lung area of a CT scan for density information

    International Nuclear Information System (INIS)

    Hedlund, L.W.; Anderson, R.F.; Goulding, P.L.; Beck, J.W.; Effmann, E.L.; Putman, C.E.

    1982-01-01

    Extracting density information from irregularly shaped tissue areas of CT scans requires automated methods when many scans are involved. We describe two computer methods that automatically isolate the lung area of a CT scan. Each starts from a single, operator specified point in the lung. The first method follows the steep density gradient boundary between lung and adjacent tissues; this tracking method is useful for estimating the overall density and total area of lung in a scan because all pixels within the lung area are available for statistical sampling. The second method finds all contiguous pixels of lung that are within the CT number range of air to water and are not a part of strong density gradient edges; this method is useful for estimating density and area of the lung parenchyma. Structures within the lung area that are surrounded by strong density gradient edges, such as large blood vessels, airways and nodules, are excluded from the lung sample while lung areas with diffuse borders, such as an area of mild or moderate edema, are retained. Both methods were tested on scans from an animal model of pulmonary edema and were found to be effective in isolating normal and diseased lungs. These methods are also suitable for isolating other organ areas of CT scans that are bounded by density gradient edges

  1. Study of lung density corrections in a clinical trial (RTOG 88-08)

    International Nuclear Information System (INIS)

    Orton, Colin G.; Chungbin, Suzanne; Klein, Eric E.; Gillin, Michael T.; Schultheiss, Timothy E.; Sause, William T.

    1998-01-01

    Purpose: To investigate the effect of lung density corrections on the dose delivered to lung cancer radiotherapy patients in a multi-institutional clinical trial, and to determine whether commonly available density-correction algorithms are sufficient to improve the accuracy and precision of dose calculation in the clinical trials setting. Methods and Materials: A benchmark problem was designed (and a corresponding phantom fabricated) to test density-correction algorithms under standard conditions for photon beams ranging from 60 Co to 24 MV. Point doses and isodose distributions submitted for a Phase III trial in regionally advanced, unresectable non-small-cell lung cancer (Radiation Therapy Oncology Group 88-08) were calculated with and without density correction. Tumor doses were analyzed for 322 patients and 1236 separate fields. Results: For the benchmark problem studied here, the overall correction factor for a four-field treatment varied significantly with energy, ranging from 1.14 ( 60 Co) to 1.05 (24 MV) for measured doses, or 1.17 ( 60 Co) to 1.05 (24 MV) for doses calculated by conventional density-correction algorithms. For the patient data, overall correction factors (calculated) ranged from 0.95 to 1.28, with a mean of 1.05 and distributional standard deviation of 0.05. The largest corrections were for lateral fields, with a mean correction factor of 1.11 and standard deviation of 0.08. Conclusions: Lung inhomogeneities can lead to significant variations in delivered dose between patients treated in a clinical trial. Existing density-correction algorithms are accurate enough to significantly reduce these variations

  2. Lung function measurements in children

    DEFF Research Database (Denmark)

    Poorisrisak, Porntiva

    2010-01-01

    was to expand normative sRaw values for non-asthmatic children in 5 centers. 105 healthy preschool children were recruited locally for sRaw measurements. Normative data was generated and was without significant difference between centers and independent of height, weight, age and gender. Furthermore......The Ph.D. thesis is based on studies conducted at 6 pediatric departments in following hospitals: Naestved, Gentofte, Kolding, Skejby, Hvidovre and Rigshospitalet. Study I: Specific airway resistance (sRaw) measured by wholebody plethysmography in preschool children is increasingly used in research...... and measured by a center specific investigator as well as an investigator visiting each center. We found sRaw measurements at two centers were significantly lower in all children compared to the other 4 centers and one center had significantly higher sRaw values than the other centers. The secondary aim...

  3. Lung function measurements in children

    DEFF Research Database (Denmark)

    Poorisrisak, Porntiva

    2010-01-01

    , there was no effect of the child's history of atopy, parental atopy or smoking. We subsequently pooled these normative data (105 children) with previous data from 121 healthy young children; mean sRaw (SD) 1.27 kPa*s (0.25). Conclusion: Control using biological standards revealed errors in factory setting......The Ph.D. thesis is based on studies conducted at 6 pediatric departments in following hospitals: Naestved, Gentofte, Kolding, Skejby, Hvidovre and Rigshospitalet. Study I: Specific airway resistance (sRaw) measured by wholebody plethysmography in preschool children is increasingly used in research...... and clinical practise. However, there is no available method for calibration of the resistance measure, which raises concern of accuracy. The primary aim was to determine the agreement of sRaw measurements in 6 centers. Seven healthy young children were brought to each of the 6 centers for sRaw measurements...

  4. The relationship between microvessels density and CT enhancement of the peripheral lung cancer

    International Nuclear Information System (INIS)

    Liu Shiyuan; Zhou Kangrong; Xiao Xiangsheng; Ye Tingjun; Zhang Zhiyong

    1999-01-01

    Objective: To investigate the relationship between microvessel density (MVD), clinical prognosis and CT enhancement of the peripheral lung cancer. Methods: 127 cases of peripheral lung cancer were examined with CT (87 cases retrospectively and 40 cases prospectively), and MVD were measured with immunohistochemical method by factor VIII on the specimens of the resected tumors. The results were analyzed and compared with CT enhancement, metastasis and prognosis. Results: The MVD was higher in the peripheral junction zone and interstitial areas than that in the parenchymal areas and necrotic zones of the tumors. Patients with nodal metastasis had higher MVD than those without nodal metastasis (56.9 +- 18.1 versus 43.8 +- 23.6, P 0.05); but the enhancement of the lung cancer correlated well with MVD (r 0.8874). Conclusions: Measurement of the microvessel density of tumor can determine the degree of angiogenesis of neoplasm and predict the metastasis or prognosis of the lung cancer. Angiogenesis not only constitutes the basis of enhancement of the tumor, but also determine the various degrees and patterns of enhancement. Spiral dynamic CT is the technique ideal to demonstrate the enhancement features, which might be helpful in making differential diagnosis of pulmonary nodules

  5. Lung function measurement in awake young children

    DEFF Research Database (Denmark)

    Bisgaard, H; Klug, B

    1995-01-01

    ) and transcutaneous measurements of oxygen tension (Ptc,O2) were compared with concomitant measurements of specific airway resistance (sRaw) and forced expiratory volume in one second (FEV1) by whole body plethysmography and spirometry, respectively, during methacholine challenge in 21 young children aged 4-6 yrs...... to methacholine in young children aged 4-6 yrs. This implies that ZIOS, Rint and Ptc,O2 provide convenient indices of changes in lung function. Their combined use will be useful for monitoring airway diseases of young children.......The aim of the study was to evaluate methods applicable in a clinical setting for monitoring of changes in lung function in awake young children. Impedance measurements by the impulse oscillation technique (ZIOS), respiratory resistance measurements by the interrupter technique (Rint...

  6. On the validity of density overrides for VMAT lung SBRT planning

    Energy Technology Data Exchange (ETDEWEB)

    Wiant, David, E-mail: david.wiant@conehealth.com; Vanderstraeten, Caroline; Maurer, Jacqueline; Pursley, Jan; Terrell, Jonathon; Sintay, Benjamin J. [Cone Health Cancer Center, Greensboro, North Carolina 27403 (United States)

    2014-08-15

    Purpose: Modeling dose to a moving target in lung is a very difficult task. Current approaches to planning lung stereotactic body radiotherapy (SBRT) generally calculate dose on either free breathing or average computed tomography (CT) scans, which do not always accurately predict dose to parts of the target volume not occupied by tumor on the planning scan. In this work, the authors look at using density overrides of the target volumes to more accurately predict dose for lung SBRT using the analytic anisotropic algorithm (AAA). Methods: Volumetric modulated arc therapy plans were created on free breathing scans (FBP), time average scans (AVGP), free breathing scans with the internal target volume overridden to tumor density (ITVP), free breathing scans with the planning target volume overridden to tumor density (PTVP), and free breathing scan using a hybrid scheme with the internal target volume set to tumor density and the planning target volume minus the internal target volume set to a density intermediate between lung and tumor (HP) for the case of a 4D motion phantom and five patient cases. Radiochromic film measurements were made for the phantom plans, with gamma analysis used to compare the planned to delivered dose. The patient plans were recalculated on each of the phases of a 4DCT to evaluate tumor coverage and conformity index (CI). A modified modulation complexity score (MCSv) and average open area per control point (AA) metrics were used to evaluate multileaf collimator (MLC) modulation for each of the plans. Results: The HP plans showed significantly higher gamma passing rates (p < 0.05) than the FBP, AVGP, and ITVP for criteria of 2 mm/2% and 1 mm/1%. No significant correlation was observed between gamma values and AA or MCSv. The tumor volume was covered by the prescription dose on all phases of the 4DCT for all patient plans. The PTVP and HP yielded lower mean CI than the other plans for all five patients, with three of the cases showing

  7. On the validity of density overrides for VMAT lung SBRT planning

    International Nuclear Information System (INIS)

    Wiant, David; Vanderstraeten, Caroline; Maurer, Jacqueline; Pursley, Jan; Terrell, Jonathon; Sintay, Benjamin J.

    2014-01-01

    Purpose: Modeling dose to a moving target in lung is a very difficult task. Current approaches to planning lung stereotactic body radiotherapy (SBRT) generally calculate dose on either free breathing or average computed tomography (CT) scans, which do not always accurately predict dose to parts of the target volume not occupied by tumor on the planning scan. In this work, the authors look at using density overrides of the target volumes to more accurately predict dose for lung SBRT using the analytic anisotropic algorithm (AAA). Methods: Volumetric modulated arc therapy plans were created on free breathing scans (FBP), time average scans (AVGP), free breathing scans with the internal target volume overridden to tumor density (ITVP), free breathing scans with the planning target volume overridden to tumor density (PTVP), and free breathing scan using a hybrid scheme with the internal target volume set to tumor density and the planning target volume minus the internal target volume set to a density intermediate between lung and tumor (HP) for the case of a 4D motion phantom and five patient cases. Radiochromic film measurements were made for the phantom plans, with gamma analysis used to compare the planned to delivered dose. The patient plans were recalculated on each of the phases of a 4DCT to evaluate tumor coverage and conformity index (CI). A modified modulation complexity score (MCSv) and average open area per control point (AA) metrics were used to evaluate multileaf collimator (MLC) modulation for each of the plans. Results: The HP plans showed significantly higher gamma passing rates (p < 0.05) than the FBP, AVGP, and ITVP for criteria of 2 mm/2% and 1 mm/1%. No significant correlation was observed between gamma values and AA or MCSv. The tumor volume was covered by the prescription dose on all phases of the 4DCT for all patient plans. The PTVP and HP yielded lower mean CI than the other plans for all five patients, with three of the cases showing

  8. Value of radio density determined by enhanced computed tomography for the differential diagnosis of lung masses

    International Nuclear Information System (INIS)

    Xie, Min

    2011-01-01

    Lung masses are often difficult to differentiate when their clinical symptoms and shapes or densities on computed tomography images are similar. However, with different pathological contents, they may appear differently on plain and enhanced computed tomography. Objectives: To determine the value of enhanced computed tomography for the differential diagnosis of lung masses based on the differences in radio density with and without enhancement. Patients and Methods: Thirty-six patients with lung cancer, 36 with pulmonary tuberculosis and 10 with inflammatory lung pseudo tumors diagnosed by computed tomography and confirmed by pathology in our hospital were selected. The mean ±SD radio densities of lung masses in the three groups of patients were calculated based on the results of plain and enhanced computed tomography. Results: There were no significant differences in the radio densities of the masses detected by plain computed tomography among patients with inflammatory lung pseudo tumors, tuberculosis and lung cancer (P> 0.05). However, there were significant differences (P< 0.01)between all the groups in terms of radio densities of masses detected by enhanced computed tomography. Conclusions: The radio densities of lung masses detected by enhanced computed tomography could potentially be used to differentiate between lung cancer, pulmonary tuberculosis and inflammatory lung pseudo tumors.

  9. Mast cell density in isolated monkey lungs on exposure to cigarette smoke.

    OpenAIRE

    Walter, A; Walter, S

    1982-01-01

    The density and percentage of degranulated cells of the mast cell population were studied in the isolated lungs of 25 monkeys (Macaca radiata radiata) before and after acute exposure to cigarette smoke. In each animal one lung was used as the test lung while the other lung was used as its control. In the control lungs the total mean mast cell count was 9.5/mm2 and the proportion of degranulated cells was 9.7%. In the lungs exposed to smoke the total counts were lower (7.3/mm2) and the percent...

  10. 18FDG uptake associated with CT density on PET/CT in lungs with and without chronic interstitial lung diseases

    International Nuclear Information System (INIS)

    Inoue, Kentaro; Okada, Ken; Taki, Yasuyuki; Goto, Ryoi; Kinomura, Shigeo; Fukuda, Hiroshi

    2009-01-01

    The dependent-density of computed tomography (CT) images of positron emission tomography (PET)/CT is sometimes difficult to distinguish from chronic interstitial lung disease (ILD) when it accompanies increased 18 F-fluorodeoxy-D-glucose ( 18 FDG) uptake. Though the possible utility of 18 FDG-PET for the diagnosis of active ILD has been reported, the clinical relevance of mild lung 18 FDG uptake in ILD cases without signs and symptoms suggesting acute progression has not been described. This study aimed to test relationships between 18 FDG uptake and lung density on CT using PET/CT in patients with normal lung as well as clinically stable chronic ILD. Thirty-six patients with normal lungs (controls) and 28 patients with chronic ILD (ILD cases) without acute exacerbation were retrospectively selected from 18 FDG PET/CT scans performed in examination of malignant neoplasms. Elliptical regions of interest (ROIs) were placed on the lung. The relationships between CT density and 18 FDG uptake between the control and ILD cases were tested. The CT density and 18 FDG uptake had a linear correlation in both the controls and the ILD cases without a difference in their regression slopes, and they were overlapped between the controls and the ILD cases with higher mean values in the ILD cases. Lung 18 FDG uptake was considered to reflect a gravity-dependent tissue density in the normal lung. Though the lung 18 FDG uptake as well as the CT density tended to be higher in chronic ILD patients, it may be difficult to distinguish them in normal dependent regions from those related to chronic ILD in some cases. (author)

  11. Precision density measuring equipment: Design, selected examples

    International Nuclear Information System (INIS)

    Karasinski, T.; Patzelt, K.; Dieker, C.; Hansen, H.; Wenzl, H.; Schober, T.

    1987-06-01

    The report deals with solids density measurement using the pyknometer, the hydrostatic balance, or the floating specimen method. The mathematical relations are derived, and error sources are shown. A detailed description is given of a measuring set-up for measuring the density of solids and liquids. An error calculation is presented. After explaining the determination of density of a standard solid body, the report describes the density measurement of monocrystalline germanium, of niobium-tritide, Ni 3 Al, Ge-Si, and gallium arsenide, the determination of space-lattice expansion by hydrogen isotopes, and of the purity of H-D mixtures. (GG) [de

  12. Measure and dimension functions: measurability and densities

    Science.gov (United States)

    Mattila, Pertti; Mauldin, R. Daniel

    1997-01-01

    During the past several years, new types of geometric measure and dimension have been introduced; the packing measure and dimension, see [Su], [Tr] and [TT1]. These notions are playing an increasingly prevalent role in various aspects of dynamics and measure theory. Packing measure is a sort of dual of Hausdorff measure in that it is defined in terms of packings rather than coverings. However, in contrast to Hausdorff measure, the usual definition of packing measure requires two limiting procedures, first the construction of a premeasure and then a second standard limiting process to obtain the measure. This makes packing measure somewhat delicate to deal with. The question arises as to whether there is some simpler method for defining packing measure and dimension. In this paper, we find a basic limitation on this possibility. We do this by determining the descriptive set-theoretic complexity of the packing functions. Whereas the Hausdorff dimension function on the space of compact sets is Borel measurable, the packing dimension function is not. On the other hand, we show that the packing dimension functions are measurable with respect to the [sigma]-algebra generated by the analytic sets. Thus, the usual sorts of measurability properties used in connection with Hausdorff measure, for example measures of sections and projections, remain true for packing measure.

  13. Mammography density estimation with automated volumetic breast density measurement

    International Nuclear Information System (INIS)

    Ko, Su Yeon; Kim, Eun Kyung; Kim, Min Jung; Moon, Hee Jung

    2014-01-01

    To compare automated volumetric breast density measurement (VBDM) with radiologists' evaluations based on the Breast Imaging Reporting and Data System (BI-RADS), and to identify the factors associated with technical failure of VBDM. In this study, 1129 women aged 19-82 years who underwent mammography from December 2011 to January 2012 were included. Breast density evaluations by radiologists based on BI-RADS and by VBDM (Volpara Version 1.5.1) were compared. The agreement in interpreting breast density between radiologists and VBDM was determined based on four density grades (D1, D2, D3, and D4) and a binary classification of fatty (D1-2) vs. dense (D3-4) breast using kappa statistics. The association between technical failure of VBDM and patient age, total breast volume, fibroglandular tissue volume, history of partial mastectomy, the frequency of mass > 3 cm, and breast density was analyzed. The agreement between breast density evaluations by radiologists and VBDM was fair (k value = 0.26) when the four density grades (D1/D2/D3/D4) were used and moderate (k value = 0.47) for the binary classification (D1-2/D3-4). Twenty-seven women (2.4%) showed failure of VBDM. Small total breast volume, history of partial mastectomy, and high breast density were significantly associated with technical failure of VBDM (p 0.001 to 0.015). There is fair or moderate agreement in breast density evaluation between radiologists and VBDM. Technical failure of VBDM may be related to small total breast volume, a history of partial mastectomy, and high breast density.

  14. Signs of Gas Trapping in Normal Lung Density Regions in Smokers.

    Science.gov (United States)

    Bodduluri, Sandeep; Reinhardt, Joseph M; Hoffman, Eric A; Newell, John D; Nath, Hrudaya; Dransfield, Mark T; Bhatt, Surya P

    2017-12-01

    A substantial proportion of subjects without overt airflow obstruction have significant respiratory morbidity and structural abnormalities as visualized by computed tomography. Whether regions of the lung that appear normal using traditional computed tomography criteria have mild disease is not known. To identify subthreshold structural disease in normal-appearing lung regions in smokers. We analyzed 8,034 subjects with complete inspiratory and expiratory computed tomographic data participating in the COPDGene Study, including 103 lifetime nonsmokers. The ratio of the mean lung density at end expiration (E) to end inspiration (I) was calculated in lung regions with normal density (ND) by traditional thresholds for mild emphysema (-910 Hounsfield units) and gas trapping (-856 Hounsfield units) to derive the ND-E/I ratio. Multivariable regression analysis was used to measure the associations between ND-E/I, lung function, and respiratory morbidity. The ND-E/I ratio was greater in smokers than in nonsmokers, and it progressively increased from mild to severe chronic obstructive pulmonary disease severity. A proportion of 26.3% of smokers without airflow obstruction had ND-E/I greater than the 90th percentile of normal. ND-E/I was independently associated with FEV 1 (adjusted β = -0.020; 95% confidence interval [CI], -0.032 to -0.007; P = 0.001), St. George's Respiratory Questionnaire scores (adjusted β = 0.952; 95% CI, 0.529 to 1.374; P smokers without airflow obstruction, and it is associated with respiratory morbidity. Clinical trial registered with www.clinicaltrials.gov (NCT00608764).

  15. Time evolution of regional CT density changes in normal lung after IMRT for NSCLC

    International Nuclear Information System (INIS)

    Bernchou, Uffe; Schytte, Tine; Bertelsen, Anders; Bentzen, Søren M.; Hansen, Olfred; Brink, Carsten

    2013-01-01

    Purpose: This study investigates the clinical radiobiology of radiation induced lung disease in terms of regional computed tomography (CT) density changes following intensity modulated radiotherapy (IMRT) for non-small-cell lung cancer (NSCLC). Methods: A total of 387 follow-up CT scans in 131 NSCLC patients receiving IMRT to a prescribed dose of 60 or 66 Gy in 2 Gy fractions were analyzed. The dose-dependent temporal evolution of the density change was analyzed using a two-component model, a superposition of an early, transient component and a late, persistent component. Results: The CT density of healthy lung tissue was observed to increase significantly (p 12 months. Conclusions: The radiobiology of lung injury may be analyzed in terms of CT density change. The initial transient change in density is consistent with radiation pneumonitis, while the subsequent stabilization of the density is consistent with pulmonary fibrosis

  16. Quantification of neonatal lung parenchymal density via ultrashort echo time MRI with comparison to CT.

    Science.gov (United States)

    Higano, Nara S; Fleck, Robert J; Spielberg, David R; Walkup, Laura L; Hahn, Andrew D; Thomen, Robert P; Merhar, Stephanie L; Kingma, Paul S; Tkach, Jean A; Fain, Sean B; Woods, Jason C

    2017-10-01

    To demonstrate that ultrashort echo time (UTE) magnetic resonance imaging (MRI) can achieve computed tomography (CT)-like quantification of lung parenchyma in free-breathing, non-sedated neonates. Because infant CTs are used sparingly, parenchymal disease evaluation via UTE MRI has potential for translational impact. Two neonatal control cohorts without suspected pulmonary morbidities underwent either a research UTE MRI (n = 5; 1.5T) or a clinically-ordered CT (n = 9). Whole-lung means and anterior-posterior gradients of UTE-measured image intensity (arbitrary units, au, normalized to muscle) and CT-measured density (g/cm 3 ) were compared (Mann-Whitney U-test). Separately, a diseased neonatal cohort (n = 5) with various pulmonary morbidities underwent both UTE MRI and CT. UTE intensity and CT density were compared with Spearman correlations within ∼33 anatomically matched regions of interest (ROIs) in each diseased subject, spanning low- to high-density tissues. Radiological classifications were evaluated in all ROIs, with mean UTE intensities and CT densities compared in each classification. In control subjects, whole-lung UTE intensities (0.51 ± 0.04 au) were similar to CT densities (0.44 ± 0.09 g/cm 3 ) (P = 0.062), as were UTE (0.021 ± 0.020 au/cm) and CT (0.034 ± 0.024 [g/cm 3 ]/cm) anterior-posterior gradients (P = 0.351). In diseased subjects' ROIs, significant correlations were observed between UTE and CT (P ≤0.007 in each case). Relative differences between UTE and CT were small in all classifications (4-25%). These results demonstrate a strong association between UTE image intensity and CT density, both between whole-lung tissue in control patients and regional radiological pathologies in diseased patients. This indicates the potential for UTE MRI to longitudinally evaluate neonatal pulmonary disease and to provide visualization of pathologies similar to CT, without sedation/anesthesia or ionizing radiation

  17. Absolute density measurements in the middle atmosphere

    Directory of Open Access Journals (Sweden)

    M. Rapp

    2001-05-01

    Full Text Available In the last ten years a total of 25 sounding rockets employing ionization gauges have been launched at high latitudes ( ~ 70° N to measure total atmospheric density and its small scale fluctuations in an altitude range between 70 and 110 km. While the determination of small scale fluctuations is unambiguous, the total density analysis has been complicated in the past by aerodynamical disturbances leading to densities inside the sensor which are enhanced compared to atmospheric values. Here, we present the results of both Monte Carlo simulations and wind tunnel measurements to quantify this aerodynamical effect. The comparison of the resulting ‘ram-factor’ profiles with empirically determined density ratios of ionization gauge measurements and falling sphere measurements provides excellent agreement. This demonstrates both the need, but also the possibility, to correct aerodynamical influences on measurements from sounding rockets. We have determined a total of 20 density profiles of the mesosphere-lower-thermosphere (MLT region. Grouping these profiles according to season, a listing of mean density profiles is included in the paper. A comparison with density profiles taken from the reference atmospheres CIRA86 and MSIS90 results in differences of up to 40%. This reflects that current reference atmospheres are a significant potential error source for the determination of mixing ratios of, for example, trace gas constituents in the MLT region.Key words. Middle atmosphere (composition and chemistry; pressure, density, and temperature; instruments and techniques

  18. Absolute density measurements in the middle atmosphere

    Directory of Open Access Journals (Sweden)

    M. Rapp

    Full Text Available In the last ten years a total of 25 sounding rockets employing ionization gauges have been launched at high latitudes ( ~ 70° N to measure total atmospheric density and its small scale fluctuations in an altitude range between 70 and 110 km. While the determination of small scale fluctuations is unambiguous, the total density analysis has been complicated in the past by aerodynamical disturbances leading to densities inside the sensor which are enhanced compared to atmospheric values. Here, we present the results of both Monte Carlo simulations and wind tunnel measurements to quantify this aerodynamical effect. The comparison of the resulting ‘ram-factor’ profiles with empirically determined density ratios of ionization gauge measurements and falling sphere measurements provides excellent agreement. This demonstrates both the need, but also the possibility, to correct aerodynamical influences on measurements from sounding rockets. We have determined a total of 20 density profiles of the mesosphere-lower-thermosphere (MLT region. Grouping these profiles according to season, a listing of mean density profiles is included in the paper. A comparison with density profiles taken from the reference atmospheres CIRA86 and MSIS90 results in differences of up to 40%. This reflects that current reference atmospheres are a significant potential error source for the determination of mixing ratios of, for example, trace gas constituents in the MLT region.

    Key words. Middle atmosphere (composition and chemistry; pressure, density, and temperature; instruments and techniques

  19. Fast response densitometer for measuring liquid density

    Science.gov (United States)

    1972-01-01

    Densitometer was developed which produces linear voltage proportional to changes in density of flowing liquid hydrogen. Unit has fast response time and good system stability, statistical variation, and thermal equilibrium. System accuracy is 2 percent of total density span. Basic design may be altered to include measurement of other flowing materials.

  20. Device for measuring fission product density

    International Nuclear Information System (INIS)

    Kaneda, Mitsunori.

    1980-01-01

    Purpose: To determine the fission product density of xenon or the like and enable measurement of real time of fission product density in a reactor by calculating the disintegration and annihilation of the fission product on the basis of neutron detected output. Constitution: The neutron flux in a reactor is detected by a detector, and applied to first and second density calculators. Second fission product density signal of xenon or the like outputted from first device is again inputted to the device to form an annihilation signal due to disintegration to determine the present density of the second fission product of xenon or the like corresponding to the decrease of the neutron due to the poison of xeron or the like. Similarly, second device determines the first fission product density of iodine or the like. (Sekiya, K.)

  1. Whole-lung volume and density in spirometrically-gated inspiratory and expiratory CT in systemic sclerosis: correlation with static volumes at pulmonary function tests.

    Science.gov (United States)

    Camiciottoli, G; Diciotti, S; Bartolucci, M; Orlandi, I; Bigazzi, F; Matucci-Cerinic, M; Pistolesi, M; Mascalchi, M

    2013-03-01

    Spiral low-dose computed tomography (LDCT) permits to measure whole-lung volume and density in a single breath-hold. To evaluate the agreement between static lung volumes measured with LDCT and pulmonary function test (PFT) and the correlation between the LDCT volumes and lung density in restrictive lung disease. Patients with Systemic Sclerosis (SSc) with (n = 24) and without (n = 16) pulmonary involvement on sequential thin-section CT and patients with chronic obstructive pulmonary disease (COPD)(n = 29) underwent spirometrically-gated LDCT at 90% and 10% of vital capacity to measure inspiratory and expiratory lung volumes and mean lung attenuation (MLA). Total lung capacity and residual volume were measured the same day of CT. Inspiratory [95% limits of agreement (95% LoA)--43.8% and 39.2%] and expiratory (95% LoA -45.8% and 37.1%) lung volumes measured on LDCT and PFT showed poor agreement in SSc patients with pulmonary involvement, whereas they were in substantial agreement (inspiratory 95% LoA -14.1% and 16.1%; expiratory 95% LoA -13.5% and 23%) in SSc patients without pulmonary involvement and in inspiratory scans only (95% LoA -23.1% and 20.9%) of COPD patients. Inspiratory and expiratory LDCT volumes, MLA and their deltas differentiated both SSc patients with or without pulmonary involvement from COPD patients. LDCT lung volumes and density were not correlated in SSc patients with pulmonary involvement, whereas they did correlate in SSc without pulmonary involvement and in COPD patients. In restrictive lung disease due to SSc there is poor agreement between static lung volumes measured using LDCT and PFT and the relationship between volume and density values on CT is altered.

  2. Current lung water measurement methods in man

    International Nuclear Information System (INIS)

    Basset, G.; Moreau, F.; Marsac, J.; Capitini, R.; Botter, F.

    1979-01-01

    Two kinds of tracer method are used to estimate the lung water pools differing by the tracer intake and the sector observed. Airborne intake gives an estimate of the tissues irrigated by the lung and bronchial circulation, whereas vascular intake only shows the sectors perfused by the lung flow. Either of these methods is suitable for a general or regional analysis. In general methods the tracer is followed at the lung exit on expired air for the first method, on peripheral arterial blood for the second. Regional methods imply partial or whole-lung external detection systems [fr

  3. Late regional density changes of the lung after radiotherapy for breast cancer

    International Nuclear Information System (INIS)

    Vagane, Randi; Danielsen, Turi; Fossa, Sophie Dorothea; Lokkevik, Erik; Olsen, Dag Rune

    2009-01-01

    Background and purpose: To investigate density changes in lung tissue, 3-4 years after postoperative adjuvant radiotherapy for breast cancer, based on dose dependence and regional differences. Material and methods: Sixty-one breast cancer patients, who had received computed tomography (CT) based postoperative radiotherapy, were included. CT scans were performed 35-51 months after start of radiotherapy. Dose information and CT scans from before and after radiotherapy were geometrically aligned in order to analyse changes in air-filled fraction (derived from CT density) as a function of dose for different regions of the lung. Results: Dose-dependent reduction of the air-filled fraction was shown to vary between the different regions of the lung. For lung tissue receiving about 50 Gy, the largest reduction in air-filled fraction was found in the cranial part of the lung. An increased air-filled fraction was observed for lung tissue irradiated to doses below 20 Gy, indicating compensatory response. Conclusions: The treatment-induced change in whole-lung density is a weighted response, involving the different regions, the irradiated volumes, and dose levels to these volumes. Simplistic models may therefore not be appropriate for describing the whole-lung dose-volume-response relationship following inhomogeneous irradiation

  4. Influence of radiation therapy on lung tissue in breast cancer patients. CT-assessed density changes 4 years after completion of radiotherapy

    International Nuclear Information System (INIS)

    Svane, G.; Rotstein, S.; Lax, I.

    1995-01-01

    CT-assessed density changes in lung tissues were measured in 22 disease-free breast cancer patients 4 years after completion of radiation therapy. All patients had previously undergone similar CT-examinations before treatment, 3 months, and 9 months after radiotherapy. In patients with visible areas of increased lung density at earlier CT-examinations a decrease of focal findings was observed at 4 years. In patients without focal findings, an increase in density relative to that before therapy was observed. The difference between the mean lung density values among those with visible radiological findings and those without was statistically significant both at 3 and 9 months after therapy. However, this difference did not persist at 4 years. These results may indicate a 2-phase development of radiation-induced lung damages - an acute phase and a late phase; the late phase emerging slowly, and in this study detectable 4 years after completion of radiation therapy. (orig.)

  5. Apparatus for measurement of tree core density

    International Nuclear Information System (INIS)

    Blincow, D.W.

    1975-01-01

    Apparatus is described for direct measurement of the density of a core sample from a tree. A radiation source and detector with a receptacle for the core therebetween, an integrator unit for the detector output, and an indicating meter driven by the integrator unit are described

  6. Measuring Air Density in the Introductory Lab

    Science.gov (United States)

    Calza, G.; Gratton, L. M.; Lopez-Arias, T.; Oss, S.

    2010-01-01

    The measurement of the mass, or the density, of air can easily be done with very simple materials and offers many interesting phenomena for discussion--buoyancy and its effects being the most obvious but not the only one. Many interesting considerations can be done regarding the behavior of gases, the effect of the external conditions in the…

  7. Adsorption Properties of Typical Lung Cancer Breath Gases on Ni-SWCNTs through Density Functional Theory

    Directory of Open Access Journals (Sweden)

    Qianqian Wan

    2017-01-01

    Full Text Available A lot of useful information is contained in the human breath gases, which makes it an effective way to diagnose diseases by detecting the typical breath gases. This work investigated the adsorption of typical lung cancer breath gases: benzene, styrene, isoprene, and 1-hexene onto the surface of intrinsic and Ni-doped single wall carbon nanotubes through density functional theory. Calculation results show that the typical lung cancer breath gases adsorb on intrinsic single wall carbon nanotubes surface by weak physisorption. Besides, the density of states changes little before and after typical lung cancer breath gases adsorption. Compared with single wall carbon nanotubes adsorption, single Ni atom doping significantly improves its adsorption properties to typical lung cancer breath gases by decreasing adsorption distance and increasing adsorption energy and charge transfer. The density of states presents different degrees of variation during the typical lung cancer breath gases adsorption, resulting in the specific change of conductivity of gas sensing material. Based on the different adsorption properties of Ni-SWCNTs to typical lung cancer breath gases, it provides an effective way to build a portable noninvasive portable device used to evaluate and diagnose lung cancer at early stage in time.

  8. Measurement of lung volume by lung perfusion scanning using SPECT and prediction of postoperative respiratory function

    International Nuclear Information System (INIS)

    Andou, Akio; Shimizu, Nobuyosi; Maruyama, Shuichiro

    1992-01-01

    Measurement of lung volume by lung perfusion scanning using single photon emission computed tomography (SPECT) and its usefulness for the prediction of respiratory function after lung resection were investigated. The lung volumes calculated in 5 patients by SPECT (threshold level 20%) using 99m Tc-macroaggregated albumin (MAA), related very closely to the actually measured lung volumes. This results prompted us to calculate the total lung volume and the volume of the lobe to be resected in 18 patients with lung cancer by SPECT. Based on the data obtained, postoperative respiratory function was predicted. The predicted values of forced vital capacity (FVC), forced expiratory volume (FEV 1.0 ), and maximum vital volume (MVV) showed closer correlations with the actually measured postoperative values (FVC, FEV 1.0 , MVV : r=0.944, r=0.917, r=0.795 respectively), than the values predicted by the ordinary lung perfusion scanning. This method facilitates more detailed evaluation of local lung function on a lobe-by-lobe basis, and can be applied clinically to predict postoperative respiratory function. (author)

  9. Acoustic levitation methods for density measurements

    Science.gov (United States)

    Trinh, E. H.; Hsu, C. J.

    1986-01-01

    The capability of ultrasonic levitators operating in air to perform density measurements has been demonstrated. The remote determination of the density of ordinary liquids as well as low density solid metals can be carried out using levitated samples with size on the order of a few millimeters and at a frequency of 20 kHz. Two basic methods may be used. The first one is derived from a previously known technique developed for acoustic levitation in liquid media, and is based on the static equilibrium position of levitated samples in the earth's gravitational field. The second approach relies on the dynamic interaction between a levitated sample and the acoustic field. The first technique appears more accurate (1 percent uncertainty), but the latter method is directly applicable to a near gravity-free environment such as that found in space.

  10. Measurement of the lunar neutron density profile

    International Nuclear Information System (INIS)

    Woolum, D.S.; Burnett, D.S.; Furst, M.; Weiss, J.R.

    1975-01-01

    An in situ measurement of the lunar neutron density from 20 to 400 g cm -2 depth below the lunar surface was made by the Apollo 17 Lunar Neutron Probe Experiment (LNPE) using particle tracks produced by the 10 B (n,α) 7 Li reaction. Both the absolute magnitude and the depth profile of the neutron density are in good agreement with theoretical calculations by Lingenfelter, Canfield, and Hampel. However, relatively small deviations between experiment and theory in the effect of Cd absorption on the neutron density and in the relative 149 Sm to 157 Gd capture rates reported previously (Russ et al., 1972) imply that the true lunar 157 Gd capture rate is about one half of that calculated theoretically. (Auth.)

  11. Airspace Dimension Assessment with nanoparticles reflects lung density as quantified by MRI

    Science.gov (United States)

    Jakobsson, Jonas K; Löndahl, Jakob; Olsson, Lars E; Diaz, Sandra; Zackrisson, Sophia; Wollmer, Per

    2018-01-01

    Background Airspace Dimension Assessment with inhaled nanoparticles is a novel method to determine distal airway morphology. This is the first empirical study using Airspace Dimension Assessment with nanoparticles (AiDA) to estimate distal airspace radius. The technology is relatively simple and potentially accessible in clinical outpatient settings. Method Nineteen never-smoking volunteers performed nanoparticle inhalation tests at multiple breath-hold times, and the difference in nanoparticle concentration of inhaled and exhaled gas was measured. An exponential decay curve was fitted to the concentration of recovered nanoparticles, and airspace dimensions were assessed from the half-life of the decay. Pulmonary tissue density was measured using magnetic resonance imaging (MRI). Results The distal airspace radius measured by AiDA correlated with lung tissue density as measured by MRI (ρ = −0.584; p = 0.0086). The linear intercept of the logarithm of the exponential decay curve correlated with forced expiratory volume in one second (FEV1) (ρ = 0.549; p = 0.0149). Conclusion The AiDA method shows potential to be developed into a tool to assess conditions involving changes in distal airways, eg, emphysema. The intercept may reflect airway properties; this finding should be further investigated.

  12. Lung Density Changes After Stereotactic Radiotherapy: A Quantitative Analysis in 50 Patients

    Energy Technology Data Exchange (ETDEWEB)

    Palma, David A., E-mail: david.palma@uwo.ca [Department of Radiation Oncology, VU University Medical Center, Amsterdam (Netherlands); Soernsen de Koste, John van; Verbakel, Wilko F.A.R. [Department of Radiation Oncology, VU University Medical Center, Amsterdam (Netherlands); Vincent, Andrew [Department of Biometrics, Netherlands Cancer Institute, Amsterdam (Netherlands); Senan, Suresh [Department of Radiation Oncology, VU University Medical Center, Amsterdam (Netherlands)

    2011-11-15

    Purpose: Radiologic lung density changes are observed in more than 50% of patients after stereotactic body radiotherapy (SBRT) for lung cancer. We studied the relationship between SBRT dose and posttreatment computed tomography (CT) density changes, a surrogate for lung injury. Methods and Materials: The SBRT fractionation schemes used to treat Stage I lung cancer with RapidArc were three fractions of 18 Gy, five fractions of 11 Gy, or eight fractions of 7.5 Gy, prescribed at the 80% isodose. Follow-up CT scans performed at less than 6 months (n = 50) and between 6 and 9 months (n = 30) after SBRT were reviewed. Posttreatment scans were coregistered with baseline scans using a B-spline deformable registration algorithm. Voxel-Hounsfield unit histograms were created for doses between 0.5 and 50 Gy. Linear mixed effects models were used to assess the effects of SBRT dose on CT density, and the influence of possible confounders was tested. Results: Increased CT density was associated with higher dose, increasing planning target volume size, and increasing time after SBRT (all p < 0.0001). Density increases were apparent in areas receiving >6 Gy, were most prominent in areas receiving >20 Gy, and seemed to plateau above 40 Gy. In regions receiving >36 Gy, the reduction in air-filled fraction of lung after treatment was up to 18%. No increase in CT density was observed in the contralateral lung receiving {>=}3 Gy. Conclusions: A dose-response relationship exists for quantitative CT density changes after SBRT. A threshold of effect is seen at low doses, and a plateau at highest doses.

  13. Lung density change after SABR: A comparative study between tri-Co-60 magnetic resonance-guided system and linear accelerator.

    Science.gov (United States)

    Kim, Eunji; Wu, Hong-Gyun; Park, Jong Min; Kim, Jung-In; Kim, Hak Jae; Kang, Hyun-Cheol

    2018-01-01

    Radiation-induced lung damage is an important treatment-related toxicity after lung stereotactic ablative radiotherapy (SABR). After implementing a tri-60Co magnetic-resonance image guided system, ViewRayTM, we compared the associated early radiological lung density changes to those associated with a linear accelerator (LINAC). Eight patients treated with the tri-60Co system were matched 1:1 with patients treated with LINAC. Prescription doses were 52 Gy or 60 Gy in four fractions, and lung dose-volumetric parameters were calculated from each planning system. The first two follow-up computed tomography (CT) were co-registered with the planning CT through deformable registration software, and lung density was measured by isodose levels. Tumor size was matched between the two groups, but the planning target volume of LINAC was larger than that of the tri-60Co system (p = 0.036). With regard to clinically relevant dose-volumetric parameters in the lungs, the ipsilateral lung mean dose, V10Gy and V20Gy were significantly poorer in tri-60Co plans compared to LINAC plans (p = 0.012, 0.036, and 0.017, respectively). Increased lung density was not observed in the first follow-up scan compared to the planning scan. A significant change of lung density was shown in the second follow-up scan and there was no meaningful difference between the tri-60Co system and LINAC for all dose regions. In addition, no patient developed clinical radiation pneumonitis until the second follow-up scan. Therefore, there was no significant difference in the early radiological lung damage between the tri-60Co system and LINAC for lung SABR despite of the inferior plan quality of the tri-60Co system compared to that of LINAC. Further studies with a longer follow-up period are needed to confirm our findings.

  14. Deep inspiration breath-hold technique for lung tumors: the potential value of target immobilization and reduced lung density in dose escalation

    International Nuclear Information System (INIS)

    Hanley, J.; Debois, M.M.; Raben, A.; Mageras, G.S.; Lutz, W.R.; Mychalczak, B.; Schwartz, L.H.; Gloeggler, P.J.; Leibel, S.A.; Fuks, Z.; Kutcher, G.J.

    1996-01-01

    compared to assess the improvement due to target immobilization and reduced lung density. To estimate the role of target immobilization alone, an additional plan is generated using the DIBH PTV, but with the assumption it is surrounded by free-breathing, not deep inspiration, density lung. Results: The results of the study suggest that the DIBH technique can reduce the mass of lung irradiated to high dose, so that the possibility for dose escalation is increased. The relative contribution of reduced lung density and reduced margin for motion vary depending on the tumor size, level of DIBH and extent of tumor motion in free-breathing. An example treatment plan comparison for a typical patient is shown in the figure, which is a cumulative dose mass histogram (DMH) depicting the mass of normal lung tissue receiving at least a certain dose. The lung DMHs shown are for three plans: (A) Free-breathing; (B) Target immobilization only; (C) Target immobilization plus reduced lung density. It is observed that the mass of lung tissue treated to high doses is less for cases B and C. For example, the mass receiving >24.5 Gy is 235 g for free-breathing (A), 180 g for immobilization alone (B) and 150 g for DIBH (C). For this patient, target immobilization alone would allow a dose escalation from 75.6 Gy to 95 Gy for the same level of NTCP as the free-breathing plan, the added effect of reduced density would then enable a further escalation from 95 Gy to 110 Gy. For this study, the measured tumor motions ranged from 5 to 12 mm for free-breathing and 1 to 3 mm for DIBH. For the example shown in the figure the tumor motion was 10 mm and DIBH reproducibility was 3 mm. Additional details on the DIBH technique and results for a group of patients will be presented. Conclusions: Compared to conventional free-breathing treatment the DIBH technique benefits from reduced margins, as a result of the suppressed target motion, as well as a decreased lung density - both contribute to moving normal lung

  15. Accurate heterogeneous dose calculation for lung cancer patients without high‐resolution CT densities

    Science.gov (United States)

    Li, Jonathan G.; Liu, Chihray; Olivier, Kenneth R.; Dempsey, James F.

    2009-01-01

    The aim of this study was to investigate the relative accuracy of megavoltage photon‐beam dose calculations employing either five bulk densities or independent voxel densities determined by calibration of the CT Houndsfield number. Full‐resolution CT and bulk density treatment plans were generated for 70 lung or esophageal cancer tumors (66 cases) using a commercial treatment planning system with an adaptive convolution dose calculation algorithm (Pinnacle3, Philips Medicals Systems). Bulk densities were applied to segmented regions. Individual and population average densities were compared to the full‐resolution plan for each case. Monitor units were kept constant and no normalizations were employed. Dose volume histograms (DVH) and dose difference distributions were examined for all cases. The average densities of the segmented air, lung, fat, soft tissue, and bone for the entire set were found to be 0.14, 0.26, 0.89, 1.02, and 1.12 g/cm3, respectively. In all cases, the normal tissue DVH agreed to better than 2% in dose. In 62 of 70 DVHs of the planning target volume (PTV), agreement to better than 3% in dose was observed. Six cases demonstrated emphysema, one with bullous formations and one with a hiatus hernia having a large volume of gas. These required the additional assignment of density to the emphysemic lung and inflammatory changes to the lung, the regions of collapsed lung, the bullous formations, and the hernia gas. Bulk tissue density dose calculation provides an accurate method of heterogeneous dose calculation. However, patients with advanced emphysema may require high‐resolution CT studies for accurate treatment planning. PACS number: 87.53.Tf

  16. Electron density measurement for steady state plasmas

    International Nuclear Information System (INIS)

    Kawano, Yasunori; Chiba, Shinichi; Inoue, Akira

    2000-01-01

    Electron density of a large tokamak has been measured successfully by the tangential CO 2 laser polarimeter developed in JT-60U. The tangential Faraday rotation angles of two different wavelength of 9.27 and 10.6 μm provided the electron density independently. Two-color polarimeter concept for elimination of Faraday rotation at vacuum windows is verified for the first time. A system stability for long time operation up to ∼10 hours is confirmed. A fluctuation of a signal baseline is observed with a period of ∼3 hours and an amplitude of 0.4 - 0.7deg. In order to improve the polarimeter, an application of diamond window for reduction of the Faraday rotation at vacuum windows and another two-color polarimeter concept for elimination of mechanical rotation component are proposed. (author)

  17. Capacitive density measurement for supercritical hydrogen

    Science.gov (United States)

    Funke, Th; Haberstroh, Ch; Szoucsek, K.; Schott, S.; Kunze, K.

    2017-12-01

    A new approach for automotive hydrogen storage systems is the so-called cryo-compressed hydrogen storage (CcH2). It has a potential for increased energy densities and thus bigger hydrogen amounts onboard, which is the main attractiveness for car manufacturers such as BMW. This system has further advantages in terms of safety, refueling and cooling potential. The current filling level measurement by means of pressure and temperature measurement and subsequent density calculation faces challenges especially in terms of precision. A promising alternative is the capacitive gauge. This measuring principle can determine the filling level of the CcH2 tank with significantly smaller tolerances. The measuring principle is based on different dielectric constants of gaseous and liquid hydrogen. These differences are successfully leveraged in liquid hydrogen storage systems (LH2). The present theoretical analysis shows that the dielectric values of CcH2 in the relevant operating range are comparable to LH2, thus achieving similarly good accuracy. The present work discusses embodiments and implementations for such a sensor in the CcH2 tank.

  18. Measurement of asbestos bodies in lung tissue of autopsy cases diagnosed with primary lung cancer

    International Nuclear Information System (INIS)

    Idei, Yuka; Kamada, Satoe; Matsumoto, Shoji; Ohnishi, Kazuo; Kitazawa, Riko; Kitazawa, Sohei

    2007-01-01

    To investigate the relation between asbestos-related lung cancer and the concentration of asbestos bodies in lung tissue, we analyzed the concentration in 24 autopsy cases diagnosed with primary lung cancer, with regard to the gender, age, histological type of lung cancer and occupation of each case. The asbestos bodies were measured according to Kohyama's method. Positive cases (more than 5,000 bodies per 1 g of dry lung tissue) were further analyzed for asbestosis and pleural plaques by chest X-ray and chest CT. Two cases exhibited more than 5,000 bodies, five cases between 1,000 and 5,000, and seventeen cases less than 1,000. The occupation of the two positive cases was not informative: one demonstrated neither asbestosis nor pleural plaques, and the other showed only pleural plaques. Although the number of cases of asbestos-related lung cancer is minimal among all lung cancer cases, the number of the former may exceed that of mesothelioma patients. Not only physicians but also radiologists, surgeons and pathologists need to collaborate in the diagnosis of asbestos-related lung cancer. (author)

  19. SU-F-T-136: Breath Hold Lung Phantom Study in Using CT Density Versus Relative Stopping Power Ratio for Proton Pencil Beam Scanning System

    Energy Technology Data Exchange (ETDEWEB)

    Syh, J; Wu, H; Rosen, L [Willis-Knighton Medical Center, Shreveport, LA (United States)

    2016-06-15

    Purpose: To evaluate mass density effects of CT conversion table and its variation in current treatment planning system of spot scanning proton beam using an IROC proton lung phantom for this study. Methods: A proton lung phantom study was acquired to Imaging and Radiation Oncology Core Houston (IROC) Quality Assurance Center. Inside the lung phantom, GAF Chromic films and couples of thermal luminescent dosimeter (TLD) capsules embedded in specified PTV and adjacent structures to monitor delivered dosage and 3D dose distribution profiles. Various material such as cork (Lung), blue water (heart), Techron HPV (ribs) and organic material of balsa wood and cork as dosimetry inserts within phantom of solid water (soft tissue). Relative stopping power (RLSP) values were provided. Our treatment planning system (TPS) doesn’t require SP instead relative density was converted relative to water. However lung phantom was irradiated by planning with density override and the results were compared with IROC measurements. The second attempt was conducted without density override and compared with IROC’s. Results: The higher passing rate of imaging and measurement results of the lung phantom irradiation met the criteria by IROC without density override. The film at coronal plane was found to be shift due to inclined cylinder insertion. The converted CT density worked as expected to correlate relative stopping power. Conclusion: The proton lung phantom provided by IROC is a useful tool to qualify our commissioned proton pencil beam delivery with TPS within reliable confidence. The relative mass stopping power ratios of materials were converted from the relative physical density relative to water and the results were satisfied.

  20. Electron density measurements on the plasma focus

    International Nuclear Information System (INIS)

    Rueckle, B.

    1976-01-01

    The paper presents a determination of the maximum electron density in a plasma focus, produced with the NESSI experimental setup, by the method of laser beam deflection. For each discharge a time-resolved measurement was performed at four different places. Neutron efficiency as well as the time of the initial X-ray emission was registrated. The principle and the economic aspects of the beam deflection method are presented in detail. The experimental findings and the resulting knowledge of the neutron efficiency are discussed. (GG) [de

  1. Regional Lung Density Changes After Radiation Therapy for Tumors in and Around Thorax

    International Nuclear Information System (INIS)

    Ma Jinli; Zhang Junan; Zhou Sumin; Hubbs, Jessica L.; Foltz, Rodney J.; Hollis, Donna R.; Light, Kim L.; Wong, Terence Z.; Kelsey, Christopher R.; Marks, Lawrence B.

    2010-01-01

    Purpose: To study the temporal nature of regional lung density changes and to assess whether the dose-dependent nature of these changes is associated with patient- and treatment-associated factors. Methods and Materials: Between 1991 and 2004, 118 patients with interpretable pre- and post-radiation therapy (RT) chest computed tomography (CT) scans were evaluated. Changes in regional lung density were related to regional dose to define a dose-response curve (DRC) for RT-induced lung injury using three-dimensional planning tools and image fusion. Multiple post-RT follow-up CT scans were evaluated by fitting linear-quadratic models of density changes on dose with time as the covariate. Various patient- and treatment-related factors were examined as well. Results: There was a dose-dependent increase in regional lung density at nearly all post-RT follow-up intervals. The population volume-weighted changes evolved over the initial 6-month period after RT and reached a plateau thereafter (p < 0.001). On univariate analysis, patient age greater than 65 years (p = 0.003) and/or the use of pre-RT surgery (p < 0.001) were associated with significantly greater changes in CT density at both 6 and 12 months after RT, but the magnitude of this effect was modest. Conclusions: There appears to be a temporal nature for the dose-dependent increases in lung density. Nondosimetric clinical factors tend to have no, or a modest, impact on these changes.

  2. Quadrature interferometry for plasma density measurements

    International Nuclear Information System (INIS)

    Warthen, B.J.; Shlachter, J.S.

    1995-01-01

    A quadrature interferometer has been used routinely in several pulsed power experiments to measure the line-averaged electron density. The optical source is a 30 mW, continuous wave Nd-YAG laser operating at 1,300 nm. The light is coupled directly to an optical fiber and split into reference and scene beams with a fiber splitter. The scene beam is transported to and from the plasma using single mode optical fibers up to 100 m in length. To simplify alignment through the plasma, the authors have used GRIN lenses on both the launch and receive sides of the single pass transmission diagnostic where this is possible. The return beam passes through a half-wave plate which is used to compensate for polarization rotation associated with slow (hour) time scale drift in the single mode fibers. The reference beam is sent through a quarter-wave plate to produce circular polarization; mixing of the reference and scene beams is accomplished using a non-polarizing beam splitter, and the interference signals are focused into additional fibers which relay the light to fast photodiodes. The quadrature optics allow for an unambiguous determination of the slope of the density changes at inflection points. All of the beam processing optics are located on a stable optical table which is remote and protected from the experiment. Final setup of the interferometer is facilitated by looking at the Lissajous figure generated from the two quadrature components. The authors have used this interferometer to diagnose the background density in the Pegasus-II power flow channel, to study the plasma plume generated in foil implosion experiments, to measure the plasma blowoff during implosions, and to understand the plasma formation mechanism in a fusion target plasma system

  3. Prediction of lung density changes after radiotherapy by cone beam computed tomography response markers and pre-treatment factors for non-small cell lung cancer patients

    DEFF Research Database (Denmark)

    Bernchou, Uffe; Hansen, Olfred; Schytte, Tine

    2015-01-01

    BACKGROUND AND PURPOSE: This study investigates the ability of pre-treatment factors and response markers extracted from standard cone-beam computed tomography (CBCT) images to predict the lung density changes induced by radiotherapy for non-small cell lung cancer (NSCLC) patients. METHODS...... AND MATERIALS: Density changes in follow-up computed tomography scans were evaluated for 135 NSCLC patients treated with radiotherapy. Early response markers were obtained by analysing changes in lung density in CBCT images acquired during the treatment course. The ability of pre-treatment factors and CBCT...

  4. Prediction of lung density changes after radiotherapy by cone beam computed tomography response markers and pre-treatment factors for non-small cell lung cancer patients.

    Science.gov (United States)

    Bernchou, Uffe; Hansen, Olfred; Schytte, Tine; Bertelsen, Anders; Hope, Andrew; Moseley, Douglas; Brink, Carsten

    2015-10-01

    This study investigates the ability of pre-treatment factors and response markers extracted from standard cone-beam computed tomography (CBCT) images to predict the lung density changes induced by radiotherapy for non-small cell lung cancer (NSCLC) patients. Density changes in follow-up computed tomography scans were evaluated for 135 NSCLC patients treated with radiotherapy. Early response markers were obtained by analysing changes in lung density in CBCT images acquired during the treatment course. The ability of pre-treatment factors and CBCT markers to predict lung density changes induced by radiotherapy was investigated. Age and CBCT markers extracted at 10th, 20th, and 30th treatment fraction significantly predicted lung density changes in a multivariable analysis, and a set of response models based on these parameters were established. The correlation coefficient for the models was 0.35, 0.35, and 0.39, when based on the markers obtained at the 10th, 20th, and 30th fraction, respectively. The study indicates that younger patients without lung tissue reactions early into their treatment course may have minimal radiation induced lung density increase at follow-up. Further investigations are needed to examine the ability of the models to identify patients with low risk of symptomatic toxicity. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  5. Uptake of low density lipoproteins by the hamster lung. Interactions with capillary endothelium

    International Nuclear Information System (INIS)

    Nistor, A.; Simionescu, M.

    1986-01-01

    The mechanism by which the circulating low density lipoproteins (LDL) contribute to the lung surfactant cholesterol was investigated by perfusing the hamster lung in situ with LDL either radiolabeled or coupled to gold, or both. Part of [ 125 I]-LDL and [ 3 H]-cholesterol LDL were taken up by a specific process which was time- and concentration-dependent and reached saturation within 20 to 30 min of perfusion. Competition experiments and removal of receptor-bound LDL by heparin suggested that about 50% of LDL uptake is receptor-independent. Experiments using double labeled LDL showed a preferential uptake of 3 H-cholesterol versus 125 I by the lung both in situ and in vivo. LDL-gold particles (LDL-Au), recirculated through the isolated lung, bound to the endothelial luminal plasma membrane and to features potentially involved in receptor-mediated endocytosis (coated pits, coated vesicles, lysosomelike structures) and in transcytosis (plasmalemmal vesicles). The results suggest that LDL uptake by the lung takes place by both receptor-mediated and receptor-independent mechanisms. Cholesterol may be in part transferred to the lung without the apoprotein moiety; the alveolar capillary endothelium appears to be the first monitor of this complex process

  6. Correlation and spectral density measurements by LDA

    International Nuclear Information System (INIS)

    Pfeifer, H.J.

    1986-01-01

    The present paper is intended to give a review on the state-of-the art in correlation and spectral density measurements by means of laser Doppler anemometry. As will be shown in detail the most important difference in performing this type of studies is the fact that laser anemometry relies on the presence of particles in the flow serving as flow velocity indicators. This means that, except in heavily seeded flows, the instantaneous velocity can only be sampled at random instants. This calls for new algorithms to calculate estimates of both correlation functions and power spectra. Various possibilities to handle the problem of random sampling have been developed in the past. They are explained from the theoretical point of view and the experimental aspects are detailed as far as they are different from conventional applications of laser anemometry

  7. Noninvasive measurement of lung carbon-11-serotonin extraction in man

    International Nuclear Information System (INIS)

    Coates, G.; Firnau, G.; Meyer, G.J.; Gratz, K.F.

    1991-01-01

    The fraction of serotonin extracted on a single passage through the lungs is being used as an early indicator of lung endothelial damage but the existing techniques require multiple arterial blood samples. We have developed a noninvasive technique to measure lung serotonin uptake in man. We utilized the double indicator diffusion principle, a positron camera, 11 C-serotonin as the substrate, and 11 CO-erythrocytes as the vascular marker. From regions of interest around each lung, we recorded time-activity curves in 0.5-sec frames for 30 sec after a bolus injection of first the vascular marker 11 CO-erythrocytes and 10 min later 11 C-serotonin. A second uptake measurement was made after imipramine 25-35 mg was infused intravenously. In three normal volunteers, the single-pass uptake of 11 C-serotonin was 63.9% +/- 3.6%. This decreased in all subjects to a mean of 53.6% +/- 1.4% after imipramine. The rate of lung washout of 11 C was also significantly prolonged after imipramine. This noninvasive technique can be used to measure lung serotonin uptake to detect early changes in a variety of conditions that alter the integrity of the pulmonary endothelium

  8. Boron uptake measurements in metastatic tumours in rat lung

    International Nuclear Information System (INIS)

    Bortolussi, S.; Altieri, S.; Bruschi, P.

    2006-01-01

    Lung carcinoma is the leading cause of cancer mortality worldwide; despite the introduction over the last few years of new therapeutic agents, very little progress has been made in terms of survival, and the overall prognosis for these patients remains poor. For these reasons any efforts to find and validate new effective therapeutic procedures for lung cancer are very timely and essential. To study the possibility to apply BNCT in the cure of diffuse pulmonary tumours, we created a BNCT Lung Project in Pavia, supported by Ministry of Education, University and Research (MIUR), in which Physicists, Medical Doctors and Biologists are involved. The first steps were; 1. development of an animal model for Boron uptake measurements in healthy and tumour lung tissues; 2. evaluation of the possibility to treat patients with epithermal neutron beams (See S. Altieri et al., this Conference); 3. in-vitro study of BNCT efficacy (see A. Zonta et al.). Spatial Boron distribution by neutron radiography in lung metastases from Colon Adenocarcinoma is reported; furthermore we present preliminary results of Boron concentration measures in rat lung tissues. The measures were performed using alpha spectrometry in thin tissue samples. (author)

  9. Radio-frequency slurry-density measurement for dredging pipelines

    NARCIS (Netherlands)

    van Eeten, M.J.C.

    2011-01-01

    Hydraulic dredgers make use of a density meter to measure the instantaneous density in the slurry transport pipeline, primarily for process control and production calculation. the current ‘golden’ standard for slurry density measurement is the radioactive density meter. It is based on a slurry

  10. Reineke’s stand density index: a quantitative and non-unitless measure of stand density

    Science.gov (United States)

    Curtis L. VanderSchaaf

    2013-01-01

    When used as a measure of relative density, Reineke’s stand density index (SDI) can be made unitless by relating the current SDI to a standard density but when used as a quantitative measure of stand density SDI is not unitless. Reineke’s SDI relates the current stand density to an equivalent number of trees per unit area in a stand with a quadratic mean diameter (Dq)...

  11. Evaluation of changes in central airway dimensions, lung area and mean lung density at paired inspiratory/expiratory high-resolution computed tomography

    International Nuclear Information System (INIS)

    Ederle, J.R.; Heussel, C.P.; Hast, J.; Ley, S.; Thelen, M.; Kauczor, H.U.; Fischer, B.; Beek, E.J.R. van

    2003-01-01

    The aim of this study was to improve the understanding of interdependencies of dynamic changes in central airway dimensions, lung area and lung density on HRCT. The HRCT scans of 156 patients obtained at full inspiratory and expiratory position were evaluated retrospectively. Patients were divided into four groups according to lung function tests: normal subjects (n=47); obstructive (n=74); restrictive (n=19); or mixed ventilatory impairment (n=16). Mean lung density (MLD) was correlated with cross-sectional area of the lung (CSA L ), cross-sectional area of the trachea (CSA T ) and diameter of main-stem bronchi (D B ). The CSA L was correlated with CSA T and D B . MLD correlated with CSA L in normal subjects (r=-0.66, p T in the control group (r=-0.50, p B was found (r=-0.52, p L and CSA T correlated in the control group (r=0.67, p L and D B correlated in the control group (r=0.42, p<0.0001) and in patients with obstructive lung disease (r=0.24, p<0.05). Correlations for patients with restrictive and mixed lung disease were constantly lower. Dependencies between central and peripheral airway dimensions and lung parenchyma are demonstrated by HRCT. Best correlations are observed in normal subjects and patients with obstructive lung disease. Based on these findings we postulate that the dependencies are the result of air-flow and pressure patterns. (orig.)

  12. Detection of Mild Emphysema by Computed Tomography Density Measurements

    International Nuclear Information System (INIS)

    Vikgren, J.; Friman, O.; Borga, M.; Boijsen, M.; Gustavsson, S.; Bake, B.; Tylen, U.; Ekberg-Jansson, A.

    2005-01-01

    Purpose: To assess the ability of a conventional density mask method to detect mild emphysema by high-resolution computed tomography (HRCT); to analyze factors influencing quantification of mild emphysema; and to validate a new algorithm for detection of mild emphysema. Material and Methods: Fifty-five healthy male smokers and 34 never-smokers, 61-62 years of age, were examined. Emphysema was evaluated visually, by the conventional density mask method, and by a new algorithm compensating for the effects of gravity and artifacts due to motion and the reconstruction algorithm. Effects of the reconstruction algorithm, slice thickness, and various threshold levels on the outcome of the density mask area were evaluated. Results: Forty-nine percent of the smokers had mild emphysema. The density mask area was higher the thinner the slice irrespective of the reconstruction algorithm and threshold level. The sharp algorithm resulted in increased density mask area. The new reconstruction algorithm could discriminate between smokers with and those without mild emphysema, whereas the density mask method could not. The diagnostic ability of the new algorithm was dependent on lung level. At about 90% specificity, sensitivity was 65-100% in the apical levels, but low in the rest of the lung. Conclusion: The conventional density mask method is inadequate for detecting mild emphysema, while the new algorithm improves the diagnostic ability but is nevertheless still imperfect

  13. Enhancements of a mechanical lung simulator for ex vivo measuring of aerosol deposition in lungs

    Czech Academy of Sciences Publication Activity Database

    Steiner, T.; Forjan, M.; Kopp, T.; Bureš, Zbyněk; Drauschke, A.

    2012-01-01

    Roč. 57, Suppl.1 (2012), s. 799-802 ISSN 0013-5585 Institutional research plan: CEZ:AV0Z50390512 Keywords : aerosol measurement * lung simulator Subject RIV: FS - Medical Facilities ; Equipment Impact factor: 1.157, year: 2012

  14. Optical measurements of lung microvascular filtration coefficient using polysulfone fibers.

    Science.gov (United States)

    Klaesner, J W; Roselli, R J; Evans, S; Pou, N A; Parker, R E; Tack, G; Parham, M

    1994-01-01

    Lung fluid balance, which is governed by the product of net transvascular pressure difference and lung filtration coefficient, can be altered in pulmonary diseases. A simple measurement of the lung filtration coefficient (Kfc) would be clinically useful and has been examined by several researchers. Current methods of determining Kfc include gravimetric measurement in isolated lungs and lymph node cannulation, neither of which can be extended to human use. Optical measurements of protein concentration changes in venous blood can be combined with pressure measurements to calculate Kfc. Blood, though, contains red corpuscles, which tend to absorb and scatter light, obscuring these optical measurements. In this study, an optical system was developed in which a polysulfone filter cartridge was used to remove red blood cells before the filtrate was passed through a spectrophotometer. Absorbance changes caused by changes in concentration of albumin labeled with Evans Blue were monitored at 620 nm after venous pressure was elevated by about 13 cm H2O. Optical measurements of Kfc averaged 0.401 +/- 0.074 (ml/min cm H2O 100 g DLW) for an isolated canine lung. Optical measurements of Kfc (0.363 +/- 0.120 ml/min cm H2O 100 g DLW) were made for the first time in an intact, closed chest sheep in which pulmonary pressure was altered by inflating a Foley balloon in the left atrium. We conclude that absorbance and scattering artifacts introduced by red blood cells can be eliminated by first filtering the blood through polysulfone fibers. Kfc measurements using the optical method are similar to values obtained by others using gravimetric methods. Finally, we have demonstrated that the technique can be used to estimate Kfc in an intact animal.

  15. X-ray measurements of water fog density

    International Nuclear Information System (INIS)

    Camp, A.L.

    1982-11-01

    Water-fog densities were measured in a laboratory experiment using x-ray diagnostics. Fog densities were measured, varying the flow rate, nozzle type, nozzle configuration, nozzle height above the x-ray beam, and water surface tension. Suspended water volume fractions between 0.0008 and 0.0074 percent were measured. The fog density increases approximately as the square root of the flow rate; the other parameters had little effect on the density

  16. Electron density measurements in the TRIAM-1 tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Mitarai, O; Nakashima, H; Nakamura, K; Hiraki, N; Toi, K [Kyushu Univ., Fukuoka (Japan). Research Inst. for Applied Mechanics

    1980-02-01

    Electron density measurements in the TRIAM-1 tokamak are carried out by a 140 GHz microwave interferometer. To follow rapid density variations, a high-speed direct-reading type interferometer is constructed. The density of (1 - 20) x 10/sup 13/ cm/sup -3/ is measured.

  17. Electron density measurements in the TRIAM-1 tokamak

    International Nuclear Information System (INIS)

    Mitarai, Osamu; Nakashima, Hisatoshi; Nakamura, Kazuo; Hiraki, Naoji; Toi, Kazuo

    1980-01-01

    Electron density measurements in the TRIAM-1 tokamak are carried out by a 140 GHz microwave interferometer. To follow rapid density variations, a high-speed direct-reading type interferometer is constructed. The density of (1 - 20) x 10 13 cm -3 is measured. (author)

  18. Method of measuring density of gas in a vessel

    International Nuclear Information System (INIS)

    Shono, Kosuke.

    1981-01-01

    Purpose: To accurately measure the density of a gas in a vessel even at a loss-of-coolant accident in a BWR type reactor. Method: When at least one of the pressure or the temperature of gas in a vessel exceeds the usable range of a gas density measuring instrument due to a loss-of-coolant accident, the gas in the vessel is sampled, and the pressure or the temperature of the sampled gas are measured by matching them to the usable conditions of the gas density measuring instrument. Hydrogen gas and oxygen gas densities exceeding the usable range of the gas density measuring instrument are calculated by the following formulae based on the measured values. C'sub(O) = P sub(T).C sub(O)/P sub(T), C'sub(H) = C''sub(H).C'sub(O)/C''sub(O), where C sub(O), P sub(T), C'sub(H) represent the oxygen density, the total pressure and the hydrogen density of the internal pressure gas of the vessel after the respective gas density measuring instruments exceed the usable ranges; C sub(O), P sub(T) represent the oxygen density and the total pressure of the gas in the vessel before the gas density measuring instruments exceeded the usable range, and C''sub(H), C''sub(O) represent the hydrogen density and oxygen density of the respective sampled gases. (Kamimura, M.)

  19. Statistical Measure Of Association Between Smoking And Lung ...

    African Journals Online (AJOL)

    Statistical Measure Of Association Between Smoking And Lung Cancer In Abakaliki, Ebonyi State Nigeria. ... East African Journal of Public Health ... To investigate the havoc caused by all these on people, questionnaire was distributed among smokers and non smokers in various areas of specialization and habitations.

  20. Procedure for Uranium-Molybdenum Density Measurements and Porosity Determination

    Energy Technology Data Exchange (ETDEWEB)

    Prabhakaran, Ramprashad [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Devaraj, Arun [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Joshi, Vineet V. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Lavender, Curt A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-08-13

    The purpose of this document is to provide guidelines for preparing uranium-molybdenum (U-Mo) specimens, performing density measurements, and computing sample porosity. Typical specimens (solids) will be sheared to small rectangular foils, disks, or pieces of metal. A mass balance, solid density determination kit, and a liquid of known density will be used to determine the density of U-Mo specimens using the Archimedes principle. A standard test weight of known density would be used to verify proper operation of the system. By measuring the density of a U-Mo sample, it is possible to determine its porosity.

  1. Plant density affects measures of biodiversity effects

    Czech Academy of Sciences Publication Activity Database

    Stachová, T.; Fibich, P.; Lepš, Jan

    2013-01-01

    Roč. 6, č. 1 (2013), s. 1-11 ISSN 1752-9921 R&D Projects: GA ČR GD206/08/H044 Grant - others:GA JU(CZ) 138/2010/P Institutional support: RVO:60077344 Keywords : biodiversity effects * plant density * constant final yield Subject RIV: EH - Ecology, Behaviour Impact factor: 2.284, year: 2013 http://jpe.oxfordjournals.org/content/early/2012/04/27/jpe.rts015.full.pdf+html

  2. Estimating snowpack density from Albedo measurement

    Science.gov (United States)

    James L. Smith; Howard G. Halverson

    1979-01-01

    Snow is a major source of water in Western United States. Data on snow depth and average snowpack density are used in mathematical models to predict water supply. In California, about 75 percent of the snow survey sites above 2750-meter elevation now used to collect data are in statutory wilderness areas. There is need for a method of estimating the water content of a...

  3. Functional residual capacity measurement by heptafluoropropane in ventilated newborn lungs

    OpenAIRE

    Kusztrich, Ariane

    2012-01-01

    Objective: Heptafluoropropane is an inert gas commercially used as propellant for inhalers. Since heptafluoropropane can be detected in low concentrations, it could also be used as a tracer gas to measure functional residual capacity. The aim of the present study was to validate functional residual capacity measurements by heptafluoropropane wash-in/wash-out (0.8%) during mechanical ventilation in small, surfactant-depleted lungs using a newborn piglet model. Design: Prospective laborato...

  4. Gamma densitometer for measuring Pu density in fuel tubes

    International Nuclear Information System (INIS)

    Winn, W.G.

    1982-01-01

    A fuel-gamma-densitometer (FGD) has been developed to examine nondestructively the uniformity of plutonium in aluminum-clad fuel tubes at the Savannah River Plant (SRP). The monitoring technique is γ-ray spectroscopy with a lead-collimated Ge(Li) detector. Plutonium density is correlated with the measured intensity of the 208 keV γ-ray from 237 U (7d) of the 241 Pu (15y) decay chain. The FGD measures the plutonium density within 0.125- or 0.25-inch-diameter areas of the 0.133- to 0.183-inch-thick tube walls. Each measurement yields a density ratio that relates the plutonium density of the measured area to the plutonium density in normal regions of the tube. The technique was used to appraise a series of fuel tubes to be irradated in an SRP reactor. High-density plutonium areas were initially identified by x-ray methods and then examined quantitatively with the FGD. The FGD reliably tested fuel tubes and yielded density ratios over a range of 0.0 to 2.5. FGD measurements examined (1) nonuniform plutonium densities or hot spots, (2) uniform high-density patches, and (3) plutonium density distribution in thin cladding regions. Measurements for tubes with known plutonium density agreed with predictions to within 2%. Attenuation measurements of the 208-keV γ-ray passage through the tube walls agreed to within 2 to 3% of calculated predictions. Collimator leakage measurements agreed with model calculations that predicted less than a 1.5% effect on plutonium density ratios. Finally, FGD measurements correlated well with x-ray transmission and fluoroscopic measurements. The data analysis for density ratios involved a small correction of about 10% for γ-shielding within the fuel tube. For hot spot examinations, limited information for this correction dictated a density ratio uncertainty of 3 to 5%

  5. Measurement of lung volumes : usefulness of spiral CT

    International Nuclear Information System (INIS)

    Kang, Ho Yeong; Kwak, Byung Kook; Lee, Sang Yoon; Kim, Soo Ran; Lee, Shin Hyung; Lee, Chang Joon; Park, In Won

    1996-01-01

    To evaluate the usefulness of spiral CT in the measurement of lung volumes. Fifteen healthy volunteers were studied by both spirometer and spiral CT at full inspiration and expiration in order to correlated their results, including total lung capacity (TLC), vital capacity (VC) and residual volume (RV). 3-D images were reconstructed from spiral CT, and we measured lung volumes at a corresponding CT window range ; their volumes were compared with the pulmonary function test (paired t-test). The window range corresponding to TLC was from -1000HU to -150HU (p=0.279, r=0.986), and for VC from -910HU to -800HU (p=0.366, r=0.954) in full-inspiratory CT. The optimal window range for RV in full-expiratory CT was from -1000HU to -450HU (p=0.757, r=0.777), and TLC-VC in full-inspiratory CT was also calculated (p=0.843, r=0.847). Spiral CT at full inspiration can used to lung volumes such as TLC, VC and RV

  6. Density measurements of small amounts of high-density solids by a floatation method

    International Nuclear Information System (INIS)

    Akabori, Mitsuo; Shiba, Koreyuki

    1984-09-01

    A floatation method for determining the density of small amounts of high-density solids is described. The use of a float combined with an appropriate floatation liquid allows us to measure the density of high-density substances in small amounts. Using the sample of 0.1 g in weight, the floatation liquid of 3.0 g cm -3 in density and the float of 1.5 g cm -3 in apparent density, the sample densities of 5, 10 and 20 g cm -3 are determined to an accuracy better than +-0.002, +-0.01 and +-0.05 g cm -3 , respectively that correspond to about +-1 x 10 -5 cm 3 in volume. By means of appropriate degassing treatments, the densities of (Th,U)O 2 pellets of --0.1 g in weight and --9.55 g cm -3 in density were determined with an accuracy better than +-0.05 %. (author)

  7. Density overwrites of internal tumor volumes in intensity modulated proton therapy plans for mobile lung tumors

    Science.gov (United States)

    Botas, Pablo; Grassberger, Clemens; Sharp, Gregory; Paganetti, Harald

    2018-02-01

    The purpose of this study was to investigate internal tumor volume density overwrite strategies to minimize intensity modulated proton therapy (IMPT) plan degradation of mobile lung tumors. Four planning paradigms were compared for nine lung cancer patients. Internal gross tumor volume (IGTV) and internal clinical target volume (ICTV) structures were defined encompassing their respective volumes in every 4DCT phase. The paradigms use different planning CT (pCT) created from the average intensity projection (AIP) of the 4DCT, overwriting the density within the IGTV to account for movement. The density overwrites were: (a) constant filling with 100 HU (C100) or (b) 50 HU (C50), (c) maximum intensity projection (MIP) across phases, and (d) water equivalent path length (WEPL) consideration from beam’s-eye-view. Plans were created optimizing dose-influence matrices calculated with fast GPU Monte Carlo (MC) simulations in each pCT. Plans were evaluated with MC on the 4DCTs using a model of the beam delivery time structure. Dose accumulation was performed using deformable image registration. Interplay effect was addressed applying 10 times rescanning. Significantly less DVH metrics degradation occurred when using MIP and WEPL approaches. Target coverage (D99≥slant 70 Gy(RBE)) was fulfilled in most cases with MIP and WEPL (D{{99}WEPL}=69.2+/- 4.0 Gy (RBE)), keeping dose heterogeneity low (D5-D{{95}WEPL}=3.9+/- 2.0 Gy(RBE)). The mean lung dose was kept lowest by the WEPL strategy, as well as the maximum dose to organs at risk (OARs). The impact on dose levels in the heart, spinal cord and esophagus were patient specific. Overall, the WEPL strategy gives the best performance and should be preferred when using a 3D static geometry for lung cancer IMPT treatment planning. Newly available fast MC methods make it possible to handle long simulations based on 4D data sets to perform studies with high accuracy and efficiency, even prior to individual treatment planning.

  8. Tomographic Measurements of Longitudinal Phase Space Density

    CERN Document Server

    Hancock, S; McIntosh, E; Metcalf, M

    1999-01-01

    Tomography : the reconstruction of a two-dimensional image from a series of its one-dimensional projections is now a very broad topic with a wealth of algorithms for the reconstruction of both qualitative and quantitative images. One of the simplest algorithms has been modified to take into account the non-linearity of large-amplitude synchrotron motion in a particle accelerator. This permits the accurate reconstruction of longitudinal phase space density from one-dimensional bunch profile data. The algorithm was developed in Mathematica TM in order to exploit the extensive built-in functions and graphics. Subsequently, it has been recoded in Fortran 90 with the aim of reducing the execution time by at least a factor of one hundred. The choice of Fortran 90 was governed by the desire ultimately to exploit parallel architectures, but sequential compilation and execution have already largely yielded the required gain in speed. The use of the method to produce longitudinal phase space plots, animated sequences o...

  9. In vivo measurement of actinides in the human lung

    International Nuclear Information System (INIS)

    Anderson, A.L.; Campbell, G.W.; Griffith, R.V.

    1979-01-01

    The problems associated with the in vivo detection and measurement of actinides in the human lung are discussed together with various measurement systems currently in use. In particular, the methods and calibration procedures employed at the Lawrence Livermore Laboratory, namely, the use of twin Phoswich detectors and a new, more realistic, tissue-equivalent phantom, are described. Methods for the measurement of chest-wall thickness, fat content, and normal human background counts are also discussed. Detection-efficiency values and minimum detectable activity estimates are given for three common actinides, 238 Pu, 239 Pu, and 241 Am

  10. Smart density: A more accurate method of measuring rural residential density for health-related research.

    Science.gov (United States)

    Owens, Peter M; Titus-Ernstoff, Linda; Gibson, Lucinda; Beach, Michael L; Beauregard, Sandy; Dalton, Madeline A

    2010-02-12

    Studies involving the built environment have typically relied on US Census data to measure residential density. However, census geographic units are often unsuited to health-related research, especially in rural areas where development is clustered and discontinuous. We evaluated the accuracy of both standard census methods and alternative GIS-based methods to measure rural density. We compared residential density (units/acre) in 335 Vermont school neighborhoods using conventional census geographic units (tract, block group and block) with two GIS buffer measures: a 1-kilometer (km) circle around the school and a 1-km circle intersected with a 100-meter (m) road-network buffer. The accuracy of each method was validated against the actual residential density for each neighborhood based on the Vermont e911 database, which provides an exact geo-location for all residential structures in the state. Standard census measures underestimate residential density in rural areas. In addition, the degree of error is inconsistent so even the relative rank of neighborhood densities varies across census measures. Census measures explain only 61% to 66% of the variation in actual residential density. In contrast, GIS buffer measures explain approximately 90% of the variation. Combining a 1-km circle with a road-network buffer provides the closest approximation of actual residential density. Residential density based on census units can mask clusters of development in rural areas and distort associations between residential density and health-related behaviors and outcomes. GIS-defined buffers, including a 1-km circle and a road-network buffer, can be used in conjunction with census data to obtain a more accurate measure of residential density.

  11. Smart density: a more accurate method of measuring rural residential density for health-related research

    Directory of Open Access Journals (Sweden)

    Gibson Lucinda

    2010-02-01

    Full Text Available Abstract Background Studies involving the built environment have typically relied on US Census data to measure residential density. However, census geographic units are often unsuited to health-related research, especially in rural areas where development is clustered and discontinuous. Objective We evaluated the accuracy of both standard census methods and alternative GIS-based methods to measure rural density. Methods We compared residential density (units/acre in 335 Vermont school neighborhoods using conventional census geographic units (tract, block group and block with two GIS buffer measures: a 1-kilometer (km circle around the school and a 1-km circle intersected with a 100-meter (m road-network buffer. The accuracy of each method was validated against the actual residential density for each neighborhood based on the Vermont e911 database, which provides an exact geo-location for all residential structures in the state. Results Standard census measures underestimate residential density in rural areas. In addition, the degree of error is inconsistent so even the relative rank of neighborhood densities varies across census measures. Census measures explain only 61% to 66% of the variation in actual residential density. In contrast, GIS buffer measures explain approximately 90% of the variation. Combining a 1-km circle with a road-network buffer provides the closest approximation of actual residential density. Conclusion Residential density based on census units can mask clusters of development in rural areas and distort associations between residential density and health-related behaviors and outcomes. GIS-defined buffers, including a 1-km circle and a road-network buffer, can be used in conjunction with census data to obtain a more accurate measure of residential density.

  12. Laser produced plasma density measurement by Mach-Zehnder interferometry

    International Nuclear Information System (INIS)

    Vaziri, A.; Kohanzadeh, Y.; Mosavi, R.K.

    1976-06-01

    This report describes an optical interferometric method of measuring the refractive index of the laser-produced plasma, giving estimates of its electron density. The plasma is produced by the interaction of a high power pulsed CO 2 laser beam with a solid target in the vacuum. The time varying plasma has a transient electron density. This transient electron density gives rise to a changing plasma refractive index. A Mach-Zehnder ruby laser interferometer is used to measure this refractive index change

  13. Quantum probability measures and tomographic probability densities

    NARCIS (Netherlands)

    Amosov, GG; Man'ko, [No Value

    2004-01-01

    Using a simple relation of the Dirac delta-function to generalized the theta-function, the relationship between the tomographic probability approach and the quantum probability measure approach with the description of quantum states is discussed. The quantum state tomogram expressed in terms of the

  14. A gauge for the measurement of wood density MGD-05

    International Nuclear Information System (INIS)

    Bartak, J.; Machaj, B.; Urbanski, P.; Pienkos, P.

    2006-01-01

    Wood density is an important parameter determining several properties of wood as: wood quality, mechanical resistance, charcoal production, transport cost, etc. Radiometric methods for the measurement of wood density are based on attenuation of 241 Am gamma radiation, or measurement of backscattered 241 Am radiation. In the paper authors describe the newly constructed computerized gauge designed for the non routine measurements. Up to 1000 measuring results can be stored in the gauge memory and the measuring results can be sent to an external laptop for computations of density contours

  15. Alpha radiation gauge for the measurement of gas density

    International Nuclear Information System (INIS)

    Lech, M.

    1977-01-01

    Alpha gauge for the measurement of gas density with thick alfa source, has been developed. The gauge is based on radiation transmission through a space filled with gas and total-count principle. Air density can be measured in the range 1,2 - 1,27 kg m -3 with a maximum standard deviation of 2 x 10 -3 kg m -3 . (author)

  16. Preionization electron density measurement by collecting electric charge

    International Nuclear Information System (INIS)

    Giordano, G.; Letardi, T.

    1988-01-01

    A method using electron collection for preionization-electron number density measurements is presented. A cathode-potential drop model is used to describe the measurement principle. There is good agreement between the model and the experimental result

  17. Spectrum of density turbulence measured by microwave reflectometer

    International Nuclear Information System (INIS)

    Ding Xuantong; Cao Janyong; Xu Deming; Zhang Hongying; Yang Qinwei

    1993-01-01

    The principle of measuring lower frequency density turbulence with microwave reflectometer is presented. Preliminary results from the HL-1 tokamak have been obtained and compared with the results measured by means of electrostatic probe

  18. Procedure of non-contacting local mass density and mass density distribution measurements

    International Nuclear Information System (INIS)

    Menzel, M.; Winkler, K.

    1985-01-01

    The invention has been aimed at a procedure of non-contacting local mass density and/or mass density distribution measurements i.e. without the interfering influence of sensors or probes. It can be applied to installations, apparatuses and pipings of chemical engineering, to tank constructions and transportation on extreme temperature and/or pressure conditions and aggressive media influences respectively. The procedure has utilized an ionizing quantum radiation whereby its unknown weakening and scattering is compensated by a suitable combination of scattering and transmission counter rate measurements in such a way that the local mass densities and the mass density distribution respectively are determinable

  19. High current density ion beam measurement techniques

    International Nuclear Information System (INIS)

    Ko, W.C.; Sawatzky, E.

    1976-01-01

    High ion beam current measurements are difficult due to the presence of the secondary particles and beam neutralization. For long Faraday cages, true current can be obtained only by negative bias on the target and by summing the cage wall and target currents; otherwise, the beam will be greatly distorted. For short Faraday cages, a combination of small magnetic field and the negative target bias results in correct beam current. Either component alone does not give true current

  20. Density and temperature measurement using CARS spectroscopy

    International Nuclear Information System (INIS)

    Hirth, A.; Vollrath, K.

    1979-01-01

    Coherent Anti Stokes Raman Scattering (CARS) a technique derived from nonlinear optics offers two major advantages compared with the spontaneous Raman method: improved scattering efficiency and spatial coherence of the scattered signal. The theory of the coherent mixing in resonant media serves as a quantitative background of the CARS technique. A review of several applications on plasma physics and gasdynamics is given, which permits to consider the CARS spectroscopy as a potential method for nonintrusive measurement of local concentration and temperature in gas flows and reactive media. (Auth.)

  1. TH-CD-207B-11: Multi-Vendor Phantom Study of CT Lung Density Metrics: Is a Reproducibility of Less Than 1 HU Achievable?

    Energy Technology Data Exchange (ETDEWEB)

    Chen-Mayer, H [National Institute of Standards & Technology, Gaithersburg, MD (United States); Judy, P [Brigham & Women’s Hospital, Boston, MA (United States); Fain, S [University of Wisconsin, Madison, WI (United States); Hoppel, B [Toshiba Medical Research Institute USA, Inc, Vernon Hills, IL (United States); Lynch, D [Nation Jewish Health, Denver, CO (United States); Fuld, M [Siemens Medical Solutions USA, Inc., Baltimore, MD (United States)

    2016-06-15

    Purpose: To standardize the calibration procedures of CT lung density measurements using low-density reference foams in a phantom, and to demonstrate a reproducibility of less than 1 HU for lung equivalent foam densities measured across CT vendor platforms and protocols. Methods: A phantom study was conducted on CT scanner models from 4 vendors at 100, 120, and 135/140 kVp and 1.5, 3, and 6 mGy dose settings, using a lung density phantom containing air, water, and 3 reference foams (indirectly calibrated) with discrete densities simulating a 5-cm slice of the human chest. Customized segmentation software was used to analyze the images and generate a mean HU and variance for each of the density for the 22 vendor/protocols. A 3-step calibration process was devised to remove a scanner-dependent parameter using linear regression of the HU value vs the relative electron density. The results were mapped to a single energy (80 keV) for final comparison. Results: The heterogeneity across vendor platforms for each density assessed by a random effects model was reduced by 50% after re-calibration, while the standard deviation of the mean HU values also improved by about the same amount. The 95% CI of the final HU value was within +/−1 HU for all 3 reference foam densities. For the backing lung foam in the phantom (served as an “unknown”), this CI is +/− 1.6 HU. The kVp and dose settings did not appear to have significant contributions to the variability. Conclusion: With the proposed calibration procedures, the inter-scanner reproducibility of better than 1 HU is demonstrated in the current phantom study for the reference foam densities, but not yet achieved for a test density. The sources of error are being investigated in the next round of scanning with a certified Standard Reference Material for direct calibration. Fain: research funding from GE Healthcare to develop pulmonary MRI techniques. Hoppel: employee of Toshiba Medical Research Institute USA

  2. Electron density and gas density measurements in a millimeter-wave discharge

    Energy Technology Data Exchange (ETDEWEB)

    Schaub, S. C., E-mail: sschaub@mit.edu; Hummelt, J. S.; Guss, W. C.; Shapiro, M. A.; Temkin, R. J. [Plasma Science and Fusion Center, Massachusetts Institute of Technology 167 Albany St., Bldg. NW16, Cambridge, Massachusetts 02139 (United States)

    2016-08-15

    Electron density and neutral gas density have been measured in a non-equilibrium air breakdown plasma using optical emission spectroscopy and two-dimensional laser interferometry, respectively. A plasma was created with a focused high frequency microwave beam in air. Experiments were run with 110 GHz and 124.5 GHz microwaves at powers up to 1.2 MW. Microwave pulses were 3 μs long at 110 GHz and 2.2 μs long at 124.5 GHz. Electron density was measured over a pressure range of 25 to 700 Torr as the input microwave power was varied. Electron density was found to be close to the critical density, where the collisional plasma frequency is equal to the microwave frequency, over the pressure range studied and to vary weakly with input power. Neutral gas density was measured over a pressure range from 150 to 750 Torr at power levels high above the threshold for initiating breakdown. The two-dimensional structure of the neutral gas density was resolved. Intense, localized heating was found to occur hundreds of nanoseconds after visible plasma formed. This heating led to neutral gas density reductions of greater than 80% where peak plasma densities occurred. Spatial structure and temporal dynamics of gas heating at atmospheric pressure were found to agree well with published numerical simulations.

  3. Electron density and gas density measurements in a millimeter-wave discharge

    International Nuclear Information System (INIS)

    Schaub, S. C.; Hummelt, J. S.; Guss, W. C.; Shapiro, M. A.; Temkin, R. J.

    2016-01-01

    Electron density and neutral gas density have been measured in a non-equilibrium air breakdown plasma using optical emission spectroscopy and two-dimensional laser interferometry, respectively. A plasma was created with a focused high frequency microwave beam in air. Experiments were run with 110 GHz and 124.5 GHz microwaves at powers up to 1.2 MW. Microwave pulses were 3 μs long at 110 GHz and 2.2 μs long at 124.5 GHz. Electron density was measured over a pressure range of 25 to 700 Torr as the input microwave power was varied. Electron density was found to be close to the critical density, where the collisional plasma frequency is equal to the microwave frequency, over the pressure range studied and to vary weakly with input power. Neutral gas density was measured over a pressure range from 150 to 750 Torr at power levels high above the threshold for initiating breakdown. The two-dimensional structure of the neutral gas density was resolved. Intense, localized heating was found to occur hundreds of nanoseconds after visible plasma formed. This heating led to neutral gas density reductions of greater than 80% where peak plasma densities occurred. Spatial structure and temporal dynamics of gas heating at atmospheric pressure were found to agree well with published numerical simulations.

  4. Interferometer for electron density measurement in exploding wire plasma

    International Nuclear Information System (INIS)

    Batra, Jigyasa; Jaiswar, Ashutosh; Kaushik, T.C.

    2016-12-01

    Mach-Zehnder Interferometer (MZI) has been developed for measuring electron density profile in pulsed plasmas. MZI is to be used for characterizing exploding wire plasmas for correlating electron density dynamics with x-rays emission. Experiments have been carried out for probing electron density in pulsed plasmas produced in our laboratory like in spark gap and exploding wire plasmas. These are microsecond phenomenon. Changes in electron density have been registered in interferograms with the help of a streak camera for specific time window. Temporal electron density profiles have been calculated by analyzing temporal fringe shifts in interferograms. This report deals with details of MZI developed in our laboratory along with its theory. Basic introductory details have also been provided for exploding wire plasmas to be probed. Some demonstrative results of electron density measurements in pulsed plasmas of spark gap and single exploding wires have been described. (author)

  5. Paramagnetic ionic liquids for measurements of density using magnetic levitation.

    Science.gov (United States)

    Bwambok, David K; Thuo, Martin M; Atkinson, Manza B J; Mirica, Katherine A; Shapiro, Nathan D; Whitesides, George M

    2013-09-03

    Paramagnetic ionic liquids (PILs) provide new capabilities to measurements of density using magnetic levitation (MagLev). In a typical measurement, a diamagnetic object of unknown density is placed in a container containing a PIL. The container is placed between two magnets (typically NdFeB, oriented with like poles facing). The density of the diamagnetic object can be determined by measuring its position in the magnetic field along the vertical axis (levitation height, h), either as an absolute value or relative to internal standards of known density. For density measurements by MagLev, PILs have three advantages over solutions of paramagnetic salts in aqueous or organic solutions: (i) negligible vapor pressures; (ii) low melting points; (iii) high thermal stabilities. In addition, the densities, magnetic susceptibilities, glass transition temperatures, thermal decomposition temperatures, viscosities, and hydrophobicities of PILs can be tuned over broad ranges by choosing the cation-anion pair. The low melting points and high thermal stabilities of PILs provide large liquidus windows for density measurements. This paper demonstrates applications and advantages of PILs in density-based analyses using MagLev.

  6. Predictive Value of Early Tumor Shrinkage and Density Reduction of Lung Metastases in Patients With Metastatic Colorectal Cancer Treated With Regorafenib.

    Science.gov (United States)

    Vanwynsberghe, Hannes; Verbeke, Xander; Coolen, Johan; Van Cutsem, Eric

    2017-12-01

    The benefit of regorafenib in colorectal cancer is not very pronounced. At present, there is lack of predictive biological or radiological markers. We studied if density reduction or small changes in size of lung metastases could be a predictive marker. We retrospectively measured density in size of lung metastases of all patients included in the CORRECT and CONSIGN trials at our center. Contrast-enhanced CT scan at baseline and at week 8 were compared. Data of progressive-free survival and overall survival were collected from the CORRECT and CONSIGN trials. A significant difference in progressive-free survival was seen in 3 groups: response or stable disease in size (5.36 vs. 3.96 months), response in density (6.03 vs. 2.72 months), and response in corrected density (6.14 vs. 3.08 months). No difference was seen for response in size versus stable disease or progressive disease in size. For overall survival, a difference was observed in the same 3 groups: response or stable disease in size (9.89 vs. 6.44 months), response in density (9.59 vs. 7.04 months), and response in corrected density (9.09 vs. 7.16 months). No difference was seen for response in size versus stable disease or progressive disease in size. Density reduction in lung metastases might be a good predictive parameter to predict outcome for regorafenib. Early tumor progression might be a negative predictive factor. If further validated, density reduction and early tumor progression might be useful to ameliorate the cost-benefit of regorafenib. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Recent advances in measurements of the nuclear level density

    International Nuclear Information System (INIS)

    John, Bency

    2007-01-01

    A short review of recent advances in measurements of the nuclear level density is given. First results of the inverse level density parameter - angular momentum correlation in a number of nuclei around Z∼50 shell region at an excitation energy around 0.3 MeV/nucleon are presented. Significant variations observed over and above the expected shell corrections are discussed in context of the emerging trends in microscopic calculations of the nuclear level density. (author)

  8. Effects of Respiration-Induced Density Variations on Dose Distributions in Radiotherapy of Lung Cancer

    International Nuclear Information System (INIS)

    Mexner, Vanessa; Wolthaus, Jochem W.H.; Herk, Marcel van; Damen, Eugene M.F.; Sonke, Jan-Jakob

    2009-01-01

    Purpose: To determine the effect of respiration-induced density variations on the estimated dose delivered to moving structures and, consequently, to evaluate the necessity of using full four-dimensional (4D) treatment plan optimization. Methods and Materials: In 10 patients with large tumor motion (median, 1.9 cm; range, 1.1-3.6 cm), the clinical treatment plan, designed using the mid-ventilation ([MidV]; i.e., the 4D-CT frame closest to the time-averaged mean position) CT scan, was recalculated on all 4D-CT frames. The cumulative dose was determined by transforming the doses in all breathing phases to the MidV geometry using deformable registration and then averaging the results. To determine the effect of density variations, this cumulative dose was compared with the accumulated dose after similarly deforming the planned (3D) MidV-dose in each respiratory phase using the same transformation (i.e., 'blurring the dose'). Results: The accumulated tumor doses, including and excluding density variations, were almost identical. Relative differences in the minimum gross tumor volume (GTV) dose were less than 2% for all patients. The relative differences were even smaller in the mean lung dose and the V20 (<0.5% and 1%, respectively). Conclusions: The effect of respiration-induced density variations on the dose accumulated over the respiratory cycle was very small, even in the presence of considerable respiratory motion. A full 4D-dose calculation for treatment planning that takes into account such density variations is therefore not required. Planning using the MidV-CT derived from 4D-CT with an appropriate margin for geometric uncertainties is an accurate and safe method to account for respiration-induced anatomy variations.

  9. A comprehensive tool for measuring mammographic density changes over time.

    Science.gov (United States)

    Eriksson, Mikael; Li, Jingmei; Leifland, Karin; Czene, Kamila; Hall, Per

    2018-06-01

    Mammographic density is a marker of breast cancer risk and diagnostics accuracy. Density change over time is a strong proxy for response to endocrine treatment and potentially a stronger predictor of breast cancer incidence. We developed STRATUS to analyse digital and analogue images and enable automated measurements of density changes over time. Raw and processed images from the same mammogram were randomly sampled from 41,353 healthy women. Measurements from raw images (using FDA approved software iCAD) were used as templates for STRATUS to measure density on processed images through machine learning. A similar two-step design was used to train density measures in analogue images. Relative risks of breast cancer were estimated in three unique datasets. An alignment protocol was developed using images from 11,409 women to reduce non-biological variability in density change. The protocol was evaluated in 55,073 women having two regular mammography screens. Differences and variances in densities were compared before and after image alignment. The average relative risk of breast cancer in the three datasets was 1.6 [95% confidence interval (CI) 1.3-1.8] per standard deviation of percent mammographic density. The discrimination was AUC 0.62 (CI 0.60-0.64). The type of image did not significantly influence the risk associations. Alignment decreased the non-biological variability in density change and re-estimated the yearly overall percent density decrease from 1.5 to 0.9%, p density measures was not influenced by mammogram type. The alignment protocol reduced the non-biological variability between images over time. STRATUS has the potential to become a useful tool for epidemiological studies and clinical follow-up.

  10. Density gradients in ceramic pellets measured by computed tomography

    International Nuclear Information System (INIS)

    Sawicka, B.D.; Palmer, B.J.F.

    1986-07-01

    Density gradients are of fundamental importance in ceramic processing and computed tomography (CT) can provide accurate measurements of density profiles in sintered and unsintered ceramic parts. As a demonstration of this potential, the density gradients in an unsintered pellet pressed from an alumina powder were measured by CT scanning. To detect such small density gradients, the CT images must have good density resolution and be free from beam-hardening effects. This was achieved by measuring high-contrast (low-noise) images with the use of an Ir-192 isotopic source. A beam-hardening correction was applied. The resulting images are discussed relative to the transmission of forces through the powder mass during the pelletizing process

  11. Magnetic induction pneumography: a planar coil system for continuous monitoring of lung function via contactless measurements

    Directory of Open Access Journals (Sweden)

    Doga Gursoy

    2010-11-01

    Full Text Available Continuous monitoring of lung function is of particular interest to the mechanically ventilated patients during critical care. Recent studies have shown that magnetic induction measurements with single coils provide signals which are correlated with the lung dynamics and this idea is extended here by using a 5 by 5 planar coil matrix for data acquisition in order to image the regional thoracic conductivity changes. The coil matrix can easily be mounted onto the patient bed, and thus, the problems faced in methods that use contacting sensors can readily be eliminated and the patient comfort can be improved. In the proposed technique, the data are acquired by successively exciting each coil in order to induce an eddy-current density within the dorsal tissues and measuring the corresponding response magnetic field strength by the remaining coils. The recorded set of data is then used to reconstruct the internal conductivity distribution by means of algorithms that minimize the residual norm between the estimated and measured data. To investigate the feasibility of the technique, the sensitivity maps and the point spread functions at different locations and depths were studied. To simulate a realistic scenario, a chest model was generated by segmenting the tissue boundaries from NMR images. The reconstructions of the ventilation distribution and the development of an edematous lung injury were presented. The imaging artifacts caused by either the incorrect positioning of the patient or the expansion of the chest wall due to breathing were illustrated by simulations.

  12. Silicon surface barrier detectors used for liquid hydrogen density measurement

    Science.gov (United States)

    James, D. T.; Milam, J. K.; Winslett, H. B.

    1968-01-01

    Multichannel system employing a radioisotope radiation source, strontium-90, radiation detector, and a silicon surface barrier detector, measures the local density of liquid hydrogen at various levels in a storage tank. The instrument contains electronic equipment for collecting the density information, and a data handling system for processing this information.

  13. Ambient RF energy scavenging: GSM and WLAN power density measurements

    NARCIS (Netherlands)

    Visser, H.J.; Reniers, A.C.F.; Theeuwes, J.A.C.

    2009-01-01

    To assess the feasibility of ambient RF energy scavenging, a survey of expected power density levels distant from GSM-900 and GSM-1800 base stations has been conducted and power density measurements have been performed in a WLAN environment. It appears that for distances ranging from 25 m to 100 m

  14. A magnetic suspension system for measuring liquid density

    Directory of Open Access Journals (Sweden)

    Luz María Centeno González

    2013-01-01

    Full Text Available Density is a derived quantity of mass and length; it is defined as mass per volume unit and its SI unit is kg/m3. National metrology institutes have been designing and building their own magnetic suspension systems during the last 5 decades for making fluid density measurements; this has allowed them to carry out research into liquids and gases’ physical characteristics. This paper was aimed at designing and developing a magnetic suspension system for a magnetic balance used in determining liquid density to be used in CENAM’s metrology density laboratories.

  15. Density measurements of microsecond-conduction-time POS plasmas

    International Nuclear Information System (INIS)

    Hinshelwood, D.; Goodrich, P.J.; Weber, B.V.; Commisso, R.J.; Grossmann, J.M.; Kellogg, J.C.

    1993-01-01

    Measurements of the electron density in a coaxial microsecond conduction time plasma opening switch during switch operation are described. Current conduction is observed to cause a radial redistribution of the switch plasma. A local reduction in axial line density of more than an order of magnitude occurs by the time opening begins. This reduction, and the scaling of conduction current with plasma density, indicate that current conduction in this experiment is limited by hydrodynamic effects. It is hypothesized that the density reduction allows the switch to open by an erosion mechanism. Initial numerical modeling efforts have reproduced the principal observed results. A model that predicts accurately the conduction current is presented

  16. PWFA plasma source - interferometric diagnostics for Li vapor density measurements

    International Nuclear Information System (INIS)

    Sivakumaran, V.; Mohandas, K.K.; Singh, Sneha; Ravi Kumar, A.V.

    2015-01-01

    A prototype (40 cm long) plasma source based on Li heat pipe oven has been developed for the Plasma Wakefield Acceleration (PWFA) experiments at IPR (IPR), Gujarat as a part of the ongoing Accelerator Programme. Li vapor in the oven is produced by heating solid Li in helium buffer gas. A uniform column of Li plasma is generated by UV photo ionization (193 nm) of the Li vapor in the heat pipe oven. In these experiments, an accurate measurement of Li vapor density is important as it has got a direct consequence on the plasma electron density. In the present experiment, the vapor density is measured optically by using Hook method (spectrally resolved white light interferometry). The hook like structure formed near the vicinity of the Li 670.8 nm resonance line was recorded with a white light Mach Zehnder interferometer crossed with an imaging spectrograph to estimate the Li vapor density. The vapor density measurements have been carried out as a function of external oven temperature and the He buffer gas pressure. This technique has the advantage of being insensitive to line broadening and line shape, and its high dynamic range even with optically thick absorption line. Here, we present the line integrated Lithium vapor density measurement using Hook method and also compare the same with other optical diagnostic techniques (White light absorption and UV absorption) for Li vapor density measurements. (author)

  17. Rapid density-measurement system with vibrating-tube densimeter

    International Nuclear Information System (INIS)

    Kayukawa, Yohei; Hasumoto, Masaya; Watanabe, Koichi

    2003-01-01

    Concerning an increasing demand for environmentally friendly refrigerants including hydrocarbons, thermodynamic properties of such new refrigerants, especially densities, are essential information for refrigeration engineering. A rapid density-measurement system with vibrating-tube densimeter was developed in the present study with an aim to supply large numbers of high-quality PVT property data in a short period. The present system needs only a few minutes to obtain a single datum, and requires less than 20 cm 3 sample fluid. PVT properties in the entire fluid-phase, vapor-pressures, saturated-liquid densities for pure fluid are available. Liquid densities, bubble-point pressures and saturated-liquid densities for mixture can be obtained. The measurement range is from 240 to 380 K for temperature and up to 7 MPa for pressure. By employing a new calibration function, density can be precisely obtained even at lower densities. The densimeter is calibrated with pure water and iso-octane which is one of the density-standard fluids, and then measurement uncertainty was evaluated to be 0.1 kg m -3 or 0.024% whichever greater in density, 0.26 kPa or 0.022% whichever greater in pressure and 3 mK for temperature, respectively. The performance of the present measurement system was examined by measuring thermodynamic properties for refrigerant R134a. The experimental results were compared with available equation of state and confirmed to agree with it within ±0.05% for liquid densities while ±0.5% in pressure for the gas phase

  18. Direct assessment of lung function in COPD using CT densitometric measures

    International Nuclear Information System (INIS)

    Gu, Suicheng; Leader, Joseph; Gur, David; Pu, Jiantao; Zheng, Bin; Chen, Qihang; Sciurba, Frank; Kminski, Naftali

    2014-01-01

    To investigate whether lung function in patients with chronic obstructive pulmonary disease (COPD) can be directly predicted using CT densitometric measures and assess the underlying prediction errors as compared with the traditional spirometry-based measures. A total of 600 CT examinations were collected from a COPD study. In addition to the entire lung volume, the extent of emphysema depicted in each CT examination was quantified using density mask analysis (densitometry). The partial least square regression was used for constructing the prediction model, where a repeated random split-sample validation was employed. For each split, we randomly selected 400 CT exams for training (regression) purpose and the remaining 200 exams for assessing performance in prediction of lung function (e.g., FEV1 and FEV1/FVC) and disease severity. The absolute and percentage errors as well as their standard deviations were computed. The averaged percentage errors in prediction of FEV1, FEV1/FVC%, TLC, RV/TLC% and DLco% predicted were 33%, 17%, 9%, 18% and 23%, respectively. When classifying the exams in terms of disease severity grades using the CT measures, 37% of the subjects were correctly classified with no error and 83% of the exams were either correctly classified or classified into immediate neighboring categories. The linear weighted kappa and quadratic weighted kappa were 0.54 (moderate agreement) and 0.72 (substantial agreement), respectively. Despite the existence of certain prediction errors in quantitative assessment of lung function, the CT densitometric measures could be used to relatively reliably classify disease severity grade of COPD patients in terms of GOLD. (paper)

  19. Negative vacuum energy densities and the causal diamond measure

    International Nuclear Information System (INIS)

    Salem, Michael P.

    2009-01-01

    Arguably a major success of the landscape picture is the prediction of a small, nonzero vacuum energy density. The details of this prediction depend in part on how the diverging spacetime volume of the multiverse is regulated, a question that remains unresolved. One proposal, the causal diamond measure, has demonstrated many phenomenological successes, including predicting a distribution of positive vacuum energy densities in good agreement with observation. In the string landscape, however, the vacuum energy density is expected to take positive and negative values. We find the causal diamond measure gives a poor fit to observation in such a landscape - in particular, 99.6% of observers in galaxies seemingly just like ours measure a vacuum energy density smaller than we do, most of them measuring it to be negative.

  20. Optimum design of a microwave interferometer for plasma density measurement

    International Nuclear Information System (INIS)

    Lindberg, L.; Eriksson, A.

    1980-11-01

    Theoretical and practical problems arising in the application of microwave interferometry to density measurements on transient plasmas are discussed. The conditions for unambiquous measurements in a density range as wide as possible are analyzed. It is shown that the initial zero adjustment of the interferometer bridge recommended in many text books is the worst possible choice of initial condition when the aim is high initial sensitivity at low densities. The analytic expressions needed for unambiquous evaluation of any phase shift from a few degrees to several times π (counting of fringes) are derived. The practical design of the interferometer circuit and its inherent error sources due to reflexions and non-ideal component properties are discussed. The results are applied to an interferometer operating at 80 GHz used on a pulsed plasma experiment. The minimum measurable phase shift is 2deg and the range of linear densities that have been measured is = 1 . 10 16 - 3 . 10 18 m -2

  1. Automated Volumetric Mammographic Breast Density Measurements May Underestimate Percent Breast Density for High-density Breasts

    NARCIS (Netherlands)

    Rahbar, K.; Gubern Merida, A.; Patrie, J.T.; Harvey, J.A.

    2017-01-01

    RATIONALE AND OBJECTIVES: The purpose of this study was to evaluate discrepancy in breast composition measurements obtained from mammograms using two commercially available software methods for systematic trends in overestimation or underestimation compared to magnetic resonance-derived

  2. Precision Electron Density Measurements in the SSX MHD Wind Tunnel

    Science.gov (United States)

    Suen-Lewis, Emma M.; Barbano, Luke J.; Shrock, Jaron E.; Kaur, Manjit; Schaffner, David A.; Brown, Michael R.

    2017-10-01

    We characterize fluctuations of the line averaged electron density of Taylor states produced by the magnetized coaxial plasma gun of the SSX device using a 632.8 nm HeNe laser interferometer. The analysis method uses the electron density dependence of the refractive index of the plasma to determine the electron density of the Taylor states. Typical magnetic field and density values in the SSX device approach about B ≅ 0.3 T and n = 0 . 4 ×1016 cm-3 . Analysis is improved from previous density measurement methods by developing a post-processing method to remove relative phase error between interferometer outputs and to account for approximately linear phase drift due to low-frequency mechanical vibrations of the interferometer. Precision density measurements coupled with local measurements of the magnetic field will allow us to characterize the wave composition of SSX plasma via density vs. magnetic field correlation analysis, and compare the wave composition of SSX plasma with that of the solar wind. Preliminary results indicate that density and magnetic field appear negatively correlated. Work supported by DOE ARPA-E ALPHA program.

  3. How Useful is Extravascular Lung Water Measurement in Managing Lung Injury in Intensive Care Unit?

    Science.gov (United States)

    Bhattacharjee, Anirban; Pradhan, Debasis; Bhattacharyya, Prithwis; Dey, Samarjit; Chhunthang, Daniala; Handique, Akash; Barman, Angkita; Yunus, Mohd

    2017-08-01

    The primary goal of septic shock management is optimization of organ perfusion, often at the risk of overloading the interstitium and causing pulmonary edema. The conventionally used end points of resuscitation do not generally include volumetric parameters such as extravascular lung water index (EVLWI) and pulmonary vascular permeability index (PVPI). This study aimed to assess the prognostic value of EVLWI and PVPI by calculating their correlation with the severity of lung injury. This prospective observational study included twenty mechanically ventilated critically ill patients with Acute Physiology and Chronic Health Evaluation score (APACHE II) >20. EVLWI and PVPI were measured using transpulmonary thermodilution, and simultaneously, PaO 2 :FiO 2 ratio, alveolar-arterial gradient of oxygen (AaDO 2 ), and chest radiograph scores from two radiologists were obtained. The correlation of EVLWI and PVPI with chest radiograph scores, PaO 2 :FiO 2 ratio, and AaDO 2 were calculated. The inter-observer agreement between the two radiologists was tested using kappa test. EVLWI and PVPI correlated modestly with PaO 2 :FiO 2 ( r = -0.32, P = 0.0004; r = -0.39, P = 0.0001). There was a better correlation of EVLWI and PVPI with PaO 2 :FiO 2 ratio ( r = -0.71, P < 0.0001; r = -0.58, P = 0.0001) in the acute respiratory distress syndrome (ARDS) subgroup. The EVLWI values correlated significantly with corresponding chest radiograph scores ( r = 0.71, P < 0.0001 for observer 1 and r = 0.68, P < 0.0001 for observer 2). EVLWI and PVPI may have a prognostic significance in the assessment of lung injury in septic shock patients with ARDS. Further research is required to reveal the usefulness of EVLWI as an end point of fluid resuscitation in the management of septic shock with ARDS.

  4. Electron density profile measurements by microwave reflectometry on Tore Supra

    International Nuclear Information System (INIS)

    Clairet, F.; Paume, M.; Chareau, J.M.

    1995-01-01

    A proposal is presented developing reflectometry diagnostic for electron density profile measurements as routine diagnostic without manual intervention as achieved at JET. Since density fluctuations seriously perturb the reflected signal and the measurement of the group delay, a method is described to overcome the irrelevant results with the help of an adaptive filtering technique. Accurate profiles are estimated for about 70% of the shots. (author) 3 refs.; 6 figs

  5. Cross-sectional changes in lung volume measured by electrical impedance tomography are representative for the whole lung in ventilated preterm infants

    NARCIS (Netherlands)

    van der Burg, Pauline S.; Miedema, Martijn; de Jongh, Frans H.; Frerichs, Inez; van Kaam, Anton H.

    2014-01-01

    Electrical impedance tomography measures lung volume in a cross-sectional slice of the lung. Whether these cross-sectional volume changes are representative of the whole lung has only been investigated in adults, showing conflicting results. This study aimed to compare cross-sectional and whole lung

  6. Mammographic density measurements are not affected by mammography system.

    Science.gov (United States)

    Damases, Christine N; Brennan, Patrick C; McEntee, Mark F

    2015-01-01

    Mammographic density (MD) is a significant risk factor for breast cancer and has been shown to reduce the sensitivity of mammography screening. Knowledge of a woman's density can be used to predict her risk of developing breast cancer and personalize her imaging pathway. However, measurement of breast density has proven to be troublesome with wide variations in density recorded using radiologists' visual Breast Imaging Reporting and Data System (BIRADS). Several automated methods for assessing breast density have been proposed, each with their own source of measurement error. The use of differing mammographic imaging systems further complicates MD measurement, especially for the same women imaged over time. The purpose of this study was to investigate whether having a mammogram on differing manufacturer's equipment affects a woman's MD measurement. Raw mammographic images were acquired on two mammography imaging systems (General Electric and Hologic) one year apart and processed using VolparaDensity™ to obtain the Volpara Density Grade (VDG) and average volumetric breast density percentage (AvBD%). Visual BIRADS scores were also obtained from 20 expert readers. BIRADS scores for both systems showed strong positive correlation ([Formula: see text]; [Formula: see text]), while the VDG ([Formula: see text]; [Formula: see text]) and AvBD% ([Formula: see text]; [Formula: see text]) showed stronger positive correlations. Substantial agreement was shown between the systems for BIRADS ([Formula: see text]; [Formula: see text]), however, the systems demonstrated an almost perfect agreement for VDG ([Formula: see text]; [Formula: see text]).

  7. Identification of early-stage usual interstitial pneumonia from low-dose chest CT scans using fractional high-density lung distribution

    Science.gov (United States)

    Xie, Yiting; Salvatore, Mary; Liu, Shuang; Jirapatnakul, Artit; Yankelevitz, David F.; Henschke, Claudia I.; Reeves, Anthony P.

    2017-03-01

    A fully-automated computer algorithm has been developed to identify early-stage Usual Interstitial Pneumonia (UIP) using features computed from low-dose CT scans. In each scan, the pre-segmented lung region is divided into N subsections (N = 1, 8, 27, 64) by separating the lung from anterior/posterior, left/right and superior/inferior in 3D space. Each subsection has approximately the same volume. In each subsection, a classic density measurement (fractional high-density volume h) is evaluated to characterize the disease severity in that subsection, resulting in a feature vector of length N for each lung. Features are then combined in two different ways: concatenation (2*N features) and taking the maximum in each of the two corresponding subsections in the two lungs (N features). The algorithm was evaluated on a dataset consisting of 51 UIP and 56 normal cases, a combined feature vector was computed for each case and an SVM classifier (RBF kernel) was used to classify them into UIP or normal using ten-fold cross validation. A receiver operating characteristic (ROC) area under the curve (AUC) was used for evaluation. The highest AUC of 0.95 was achieved by using concatenated features and an N of 27. Using lung partition (N = 27, 64) with concatenated features had significantly better result over not using partitions (N = 1) (p-value < 0.05). Therefore this equal-volume partition fractional high-density volume method is useful in distinguishing early-stage UIP from normal cases.

  8. Ultrasonic Technique for Density Measurement of Liquids in Extreme Conditions

    Directory of Open Access Journals (Sweden)

    Rymantas Kazys

    2015-08-01

    Full Text Available An ultrasonic technique, invariant to temperature changes, for a density measurement of different liquids under in situ extreme conditions is presented. The influence of geometry and material parameters of the measurement system (transducer, waveguide, matching layer on measurement accuracy and reliability is analyzed theoretically along with experimental results. The proposed method is based on measurement of the amplitude of the ultrasonic wave, reflected from the interface of the solid/liquid medium under investigation. In order to enhance sensitivity, the use of a quarter wavelength acoustic matching layer is proposed. Therefore, the sensitivity of the measurement system increases significantly. Density measurements quite often must be performed in extreme conditions at high temperature (up to 220 °C and high pressure. In this case, metal waveguides between piezoelectric transducer and the measured liquid are used in order to protect the conventional transducer from the influence of high temperature and to avoid depolarization. The presented ultrasonic density measurement technique is suitable for density measurement in different materials, including liquids and polymer melts in extreme conditions. A new calibration algorithm was proposed. The metrological evaluation of the measurement method was performed. The expanded measurement uncertainty Uρ = 7.4 × 10−3 g/cm3 (1%.

  9. Ultrasonic Technique for Density Measurement of Liquids in Extreme Conditions

    Science.gov (United States)

    Kazys, Rymantas; Sliteris, Reimondas; Rekuviene, Regina; Zukauskas, Egidijus; Mazeika, Liudas

    2015-01-01

    An ultrasonic technique, invariant to temperature changes, for a density measurement of different liquids under in situ extreme conditions is presented. The influence of geometry and material parameters of the measurement system (transducer, waveguide, matching layer) on measurement accuracy and reliability is analyzed theoretically along with experimental results. The proposed method is based on measurement of the amplitude of the ultrasonic wave, reflected from the interface of the solid/liquid medium under investigation. In order to enhance sensitivity, the use of a quarter wavelength acoustic matching layer is proposed. Therefore, the sensitivity of the measurement system increases significantly. Density measurements quite often must be performed in extreme conditions at high temperature (up to 220 °C) and high pressure. In this case, metal waveguides between piezoelectric transducer and the measured liquid are used in order to protect the conventional transducer from the influence of high temperature and to avoid depolarization. The presented ultrasonic density measurement technique is suitable for density measurement in different materials, including liquids and polymer melts in extreme conditions. A new calibration algorithm was proposed. The metrological evaluation of the measurement method was performed. The expanded measurement uncertainty Uρ = 7.4 × 10−3 g/cm3 (1%). PMID:26262619

  10. Ultrasonic Technique for Density Measurement of Liquids in Extreme Conditions.

    Science.gov (United States)

    Kazys, Rymantas; Sliteris, Reimondas; Rekuviene, Regina; Zukauskas, Egidijus; Mazeika, Liudas

    2015-08-07

    An ultrasonic technique, invariant to temperature changes, for a density measurement of different liquids under in situ extreme conditions is presented. The influence of geometry and material parameters of the measurement system (transducer, waveguide, matching layer) on measurement accuracy and reliability is analyzed theoretically along with experimental results. The proposed method is based on measurement of the amplitude of the ultrasonic wave, reflected from the interface of the solid/liquid medium under investigation. In order to enhance sensitivity, the use of a quarter wavelength acoustic matching layer is proposed. Therefore, the sensitivity of the measurement system increases significantly. Density measurements quite often must be performed in extreme conditions at high temperature (up to 220 °C) and high pressure. In this case, metal waveguides between piezoelectric transducer and the measured liquid are used in order to protect the conventional transducer from the influence of high temperature and to avoid depolarization. The presented ultrasonic density measurement technique is suitable for density measurement in different materials, including liquids and polymer melts in extreme conditions. A new calibration algorithm was proposed. The metrological evaluation of the measurement method was performed. The expanded measurement uncertainty Uρ = 7.4 × 10(-3) g/cm(3) (1%).

  11. RZP 202 - a modular system for surface density measurement

    International Nuclear Information System (INIS)

    Severa, L.; Merinsky, J.

    The sensing element is an ionization chamber of the type that has maximum sensitivity to beta radiation of the used radionuclide ( 147 Pm, 85 Kr, 90 Sr- 90 Y) or to gamma radiation of radionuclide 241 Am. Collimation shields were developed for the said sources. Measurement of the ionization currents is made with an electrometer with a vibration capacitor. Invariable configuration is secured by a measuring arm. The modular units are of the CAMAC system design. The surface density meters measure deviations from the rated surface density. The scale for inputting surface density is linear. The configuration, functional continuity of the individual parts and the possibility of variant designs of surface density meters are described and the technical parameters of RZP 202 and its configuration and design are given

  12. Wireless Sensor Node for Surface Seawater Density Measurements

    Directory of Open Access Journals (Sweden)

    Roberto Saletti

    2012-03-01

    Full Text Available An electronic meter to measure surface seawater density is presented. It is based on the measurement of the difference in displacements of a surface level probe and a weighted float, which according to Archimedes’ law depends on the density of the water. The displacements are simultaneously measured using a high-accuracy magnetostrictive sensor, to which a custom electronic board provides a wireless connection and power supply so that it can become part of a wireless sensor network. The electronics are designed so that different kinds of wireless networks can be used, by simply changing the wireless module and the relevant firmware of the microcontroller. Lastly, laboratory and at-sea tests are presented and discussed in order to highlight the functionality and the performance of a prototype of the wireless density meter node in a Bluetooth radio network. The experimental results show a good agreement of the values of the calculated density compared to reference hydrometer readings.

  13. Wireless sensor node for surface seawater density measurements.

    Science.gov (United States)

    Baronti, Federico; Fantechi, Gabriele; Roncella, Roberto; Saletti, Roberto

    2012-01-01

    An electronic meter to measure surface seawater density is presented. It is based on the measurement of the difference in displacements of a surface level probe and a weighted float, which according to Archimedes' law depends on the density of the water. The displacements are simultaneously measured using a high-accuracy magnetostrictive sensor, to which a custom electronic board provides a wireless connection and power supply so that it can become part of a wireless sensor network. The electronics are designed so that different kinds of wireless networks can be used, by simply changing the wireless module and the relevant firmware of the microcontroller. Lastly, laboratory and at-sea tests are presented and discussed in order to highlight the functionality and the performance of a prototype of the wireless density meter node in a Bluetooth radio network. The experimental results show a good agreement of the values of the calculated density compared to reference hydrometer readings.

  14. Dosimetry in single lung cells by means of microautoradiographic activity measurements

    International Nuclear Information System (INIS)

    Kraus, W.

    1976-01-01

    After inhalation of compounds containing promethium-147 in the lungs of mice most of the activity was deposited in the form of local concentrations (hotspots). By means of a special quantitative microautoradiographic method using stripping film ORWO K 105, measurements of the activity of single hotspots of about 10 -14 Ci were possible. A microphotometer with a variable measuring diaphragm was used for the determination of the density profile of the autoradiographic image in order to get hotspot depth within the biological specimen. To determine hotspot activity it was necessary to calibrate the film with a Pm-147 plane source. The systematic and random errors of the method are discussed in detail, giving a total error of +- 21% (SD) for one hotspot activity measurement. A few examples of biological results obtained by the method are given. Simple models were used to calculate doses absorbed in macrophage and alveolar cell nuclei from the measured activities. (author)

  15. Measurement of lung tumor motion using respiration-correlated CT

    International Nuclear Information System (INIS)

    Mageras, Gig S.; Pevsner, Alex; Yorke, Ellen D.; Rosenzweig, Kenneth E.; Ford, Eric C.; Hertanto, Agung; Larson, Steven M.; Lovelock, D. Michael; Erdi, Yusuf E.; Nehmeh, Sadek A.; Humm, John L.; Ling, C. Clifton

    2004-01-01

    Purpose: We investigate the characteristics of lung tumor motion measured with respiration-correlated computed tomography (RCCT) and examine the method's applicability to radiotherapy planning and treatment. Methods and materials: Six patients treated for non-small-cell lung carcinoma received a helical single-slice computed tomography (CT) scan with a slow couch movement (1 mm/s), while simultaneously respiration is recorded with an external position-sensitive monitor. Another 6 patients receive a 4-slice CT scan in a cine mode, in which sequential images are acquired for a complete respiratory cycle at each couch position while respiration is recorded. The images are retrospectively resorted into different respiration phases as measured with the external monitor (4-slice data) or patient surface displacement observed in the images (single-slice data). The gross tumor volume (GTV) in lung is delineated at one phase and serves as a visual guide for delineation at other phases. Interfractional GTV variation is estimated by scaling diaphragm position variations measured in gated radiographs at treatment with the ratio of GTV:diaphragm displacement observed in the RCCT data. Results: Seven out of 12 patients show GTV displacement with respiration of more than 1 cm, primarily in the superior-inferior (SI) direction; 2 patients show anterior-posterior displacement of more than 1 cm. In all cases, extremes in GTV position in the SI direction are consistent with externally measured extremes in respiration. Three patients show evidence of hysteresis in GTV motion, in which the tumor trajectory is displaced 0.2 to 0.5 cm anteriorly during expiration relative to inspiration. Significant (>1 cm) expansion of the GTV in the SI direction with respiration is observed in 1 patient. Estimated intrafractional GTV motion for gated treatment at end expiration is 0.6 cm or less in all cases; however; interfraction variation estimates (systematic plus random) are more than 1 cm in 3

  16. Relationship of the Functional Movement Screen In-Line Lunge to Power, Speed, and Balance Measures

    OpenAIRE

    Hartigan, Erin H.; Lawrence, Michael; Bisson, Brian M.; Torgerson, Erik; Knight, Ryan C.

    2014-01-01

    Background: The in-line lunge of the Functional Movement Screen (FMS) evaluates lateral stability, balance, and movement asymmetries. Athletes who score poorly on the in-line lunge should avoid activities requiring power or speed until scores are improved, yet relationships between the in-line lunge scores and other measures of balance, power, and speed are unknown. Hypothesis: (1) Lunge scores will correlate with center of pressure (COP), maximum jump height (MJH), and 36.6-meter sprint time...

  17. Electron density values of various human tissues: in vitro Compton scatter measurements and calculated ranges

    International Nuclear Information System (INIS)

    Shrimpton, P.C.

    1981-01-01

    Accurate direct measurements of electron density have been performed on specimens from 10 different tissue types of the human body, representing the major organs, using a Compton scatter technique. As a supplement to these experimental values, calculations have been carried out to determine the electron densities expected for these tissue types. The densities observed are in good agreement with the broad ranges deduced from the basic data previously published. The results of both the in vitro sample measurements and the approximate calculations indicate that the electron density of most normal healthy soft tissue can be expected to fall within the fairly restricted range of +- 5% around 3.4 X 10 23 electrons per cm 3 . The obvious exception to this generalisation is the result for lung tissue, which falls considerably below this range owing to the high air content inherent in its construction. In view of such an overall limited variation with little difference between tissues, it would appear that electron density alone is likely to be a rather poor clinical parameter for tissue analysis, with high accuracy and precision being essential in any in vivo Compton measurements for imaging or diagnosis on specific organs. (author)

  18. Measurement and analyses of molten Ni-Co alloy density

    Institute of Scientific and Technical Information of China (English)

    XIAO Feng; K. MUKAI; FANG Liang; FU Ya; YANG Ren-hui

    2006-01-01

    With the advent of powerful mathematical modeling techniques for material phenomena, there is renewed interest in reliable data for the density of the Ni-based superalloys. Up to now, there has been few report on the density of molten Ni-Co alloy.In order to obtain more accurate density data for molten Ni-Co alloy, the density of molten Ni-Co alloy was measured with a modified sessile drop method, and the accommodation of different atoms in molten Ni-Co alloy was analyzed. The density of alloy is found to decrease with increasing temperature and Co concentration in the alloy. The molar volume of molten Ni-Co alloy increases with increasing Co concentration. The molar volume of Ni-Co alloy determined shows a positive deviation from the linear molar volume, and the deviation of molar volume from ideal mixing increases with increasing Co concentration over the experimental concentration range.

  19. Why do we need more data on MR volumetric measurements of the fetal lung?

    International Nuclear Information System (INIS)

    Rubesova, Erika

    2016-01-01

    Fetal lung hypoplasia is associated with a series of congenital anomalies, particularly the congenital diaphragmatic hernia. Evaluation of the severity of the lung hypoplasia is important for parental counseling, assessment of prognosis and planning of postnatal management. Although a large number of studies have been performed to measure fetal lung volumes in order to predict outcome, there are little data on fetuses younger than 24 weeks of gestation, the age when parental counseling is crucial if termination is considered. Few studies have evaluated prognosis of lung hypoplasia in fetuses with congenital chest anomalies other than congenital diaphragmatic hernia. We review the studies on measurements of the fetal lung volumes by MRI. (orig.)

  20. Why do we need more data on MR volumetric measurements of the fetal lung?

    Energy Technology Data Exchange (ETDEWEB)

    Rubesova, Erika [Stanford University, Pediatric Radiology, Lucile Packard Children' s Hospital at Stanford, Stanford, CA (United States)

    2016-02-15

    Fetal lung hypoplasia is associated with a series of congenital anomalies, particularly the congenital diaphragmatic hernia. Evaluation of the severity of the lung hypoplasia is important for parental counseling, assessment of prognosis and planning of postnatal management. Although a large number of studies have been performed to measure fetal lung volumes in order to predict outcome, there are little data on fetuses younger than 24 weeks of gestation, the age when parental counseling is crucial if termination is considered. Few studies have evaluated prognosis of lung hypoplasia in fetuses with congenital chest anomalies other than congenital diaphragmatic hernia. We review the studies on measurements of the fetal lung volumes by MRI. (orig.)

  1. Electron and current density measurements on tokamak plasmas

    International Nuclear Information System (INIS)

    Lammeren, A.C.A.P. van.

    1991-01-01

    The first part of this thesis describes the Thomson-scattering diagnostic as it was present at the TORTUR tokamak. For the first time with this diagnostic a complete tangential scattering spectrum was recorded during one single laser pulse. From this scattering spectrum the local current density was derived. Small deviations from the expected gaussian scattering spectrum were observed indicating the non-Maxwellian character of the electron-velocity distribution. The second part of this thesis describes the multi-channel interferometer/ polarimeter diagnostic which was constructed, build and operated on the Rijnhuizen Tokamak Project (RTP) tokamak. The diagnostic was operated routinely, yielding the development of the density profiles for every discharge. When ECRH (Electron Cyclotron Resonance Heating) is switched on the density profile broadens, the central density decreases and the total density increases, the opposite takes place when ECRH is switched off. The influence of MHD (magnetohydrodynamics) activity on the density was clearly observable. In the central region of the plasma it was measured that in hydrogen discharges the so-called sawtooth collapse is preceded by an m=1 instability which grows rapidly. An increase in radius of this m=1 mode of 1.5 cm just before the crash is observed. In hydrogen discharges the sawtooth induced density pulse shows an asymmetry for the high- and low-field side propagation. This asymmetry disappeared for helium discharges. From the location of the maximum density variations during an m=2 mode the position of the q=2 surface is derived. The density profiles are measured during the energy quench phase of a plasma disruption. A fast flattening and broadening of the density profile is observed. (author). 95 refs.; 66 figs.; 7 tabs

  2. Nondestructive density measured in powder metallurgy and ceramics

    International Nuclear Information System (INIS)

    Schlieper, G.; Arnold, V.; Dirkes, H.

    1989-01-01

    Absorption measurements with gamma radiation have been utilized for the determination of porosities (densities) in materials compacted or sintered from metallic or ceramic powders. The mathematical background for the assessment of this method, and for evaluations of the accuracy of measurement is presented within the reported paper. The equipment for the practical application of density measurements in industry has been developed. Hardware and software of this computerized instrument are designed for a maximum of safety, ease of operation, reliability, flexibility, and efficiency. (orig./RHM) [de

  3. Space potential, temperature, and density profile measurements on RENTOR

    International Nuclear Information System (INIS)

    Schoch, P.M.

    1983-05-01

    Radial profiles of the space potential, electron temperature, and density have been measured on RENTOR with a heavy-ion-beam probe. The potential profile has been compared to predictions from a stochastic magnetic field fluctuation theory, using the measured temperature and density profiles. The comparison shows strong qualitative agreement in that the potential is positive and the order of T/sub e//e. There is some quantitative disagreement in that the measured radial electric fields are somewhat smaller than the theoretical predictions. To facilitate this comparison, a detailed analysis of the possible errors has been completed

  4. Rocket measurements of electron density irregularities during MAC/SINE

    Science.gov (United States)

    Ulwick, J. C.

    1989-01-01

    Four Super Arcas rockets were launched at the Andoya Rocket Range, Norway, as part of the MAC/SINE campaign to measure electron density irregularities with high spatial resolution in the cold summer polar mesosphere. They were launched as part of two salvos: the turbulent/gravity wave salvo (3 rockets) and the EISCAT/SOUSY radar salvo (one rocket). In both salvos meteorological rockets, measuring temperature and winds, were also launched and the SOUSY radar, located near the launch site, measured mesospheric turbulence. Electron density irregularities and strong gradients were measured by the rocket probes in the region of most intense backscatter observed by the radar. The electron density profiles (8 to 4 on ascent and 4 on descent) show very different characteristics in the peak scattering region and show marked spatial and temporal variability. These data are intercompared and discussed.

  5. Plasma density measurements from the GEOS-1 relaxation sounder

    International Nuclear Information System (INIS)

    Etcheto, J.; Bloch, J.J.

    1978-01-01

    The relaxation sounder uses the characteristics of the propagation of radiowaves to sound the plasma surrounding the spacecraft. It determines, in particular, the plasma frequency, which gives the electron density. Measurements over the whole dayside of the magnetosphere, from the evening to the night sectors, are now available. The behaviour of the plasma resonance depends on local time, the nighttime echoes being generally weaker. Density measurements thus obtained are shown and discussed in the context of what is presently known about the plasma distribution in the magnetosphere. In particular, the density around apogee is studied as a function of magnetic activity. On the dayside, it appears to vary between a few and a few tens of electrons per cubic centimeter. The evolution of the density profile for several consecutive days is studied and interpreted tracing back the drift of the particles. (Auth.)

  6. Density dependence of stopping cross sections measured in liquid ethane

    International Nuclear Information System (INIS)

    Both, G.; Krotz, R.; Lohmer, K.; Neuwirth, W.

    1983-01-01

    Electronic stopping cross sections for 7 Li projectiles (840--175 keV) have been measured with the inverted Doppler-shift attenuation method in liquid ethane (C 2 H 6 ) at two different densities. The density of the target has been varied by changing the temperature, and measurements have been performed at 0.525 g/cm 3 (199 K) and 0.362 g/cm 3 (287 K). At the higher density the stopping cross section is about 2% smaller. This result agrees with a calculation of the stopping cross section of liquid ethane, applying Lindhard's theory in the local-density approximation using a simple model of the liquid. It is also in agreement with various observations of the so-called physical-state effect, which show that the stopping cross section of the same substance is smaller in a condensed phase than in the gaseous one

  7. WSN-Based Space Charge Density Measurement System.

    Science.gov (United States)

    Deng, Dawei; Yuan, Haiwen; Lv, Jianxun; Ju, Yong

    2017-01-01

    It is generally acknowledged that high voltage direct current (HVDC) transmission line endures the drawback of large area, because of which the utilization of cable for space charge density monitoring system is of inconvenience. Compared with the traditional communication network, wireless sensor network (WSN) shows advantages in small volume, high flexibility and strong self-organization, thereby presenting great potential in solving the problem. Additionally, WSN is more suitable for the construction of distributed space charge density monitoring system as it has longer distance and higher mobility. A distributed wireless system is designed for collecting and monitoring the space charge density under HVDC transmission lines, which has been widely applied in both Chinese state grid HVDC test base and power transmission projects. Experimental results of the measuring system demonstrated its adaptability in the complex electromagnetic environment under the transmission lines and the ability in realizing accurate, flexible, and stable demands for the measurement of space charge density.

  8. TH-CD-202-06: A Method for Characterizing and Validating Dynamic Lung Density Change During Quiet Respiration

    Energy Technology Data Exchange (ETDEWEB)

    Dou, T [University of California, Los Angeles, Los Angeles, CA (United States); Ruan, D [UCLA School of Medicine, Los Angeles, CA (United States); Heinrich, M [Institute of Medical Informatics, University of Lubeck, Lubeck, Schleswig-Holstein (Germany); Low, D [UCLA, Los Angeles, CA (United States)

    2016-06-15

    Purpose: To obtain a functional relationship that calibrates the lung tissue density change under free breathing conditions through correlating Jacobian values to the Hounsfield units. Methods: Free-breathing lung computed tomography images were acquired using a fast helical CT protocol, where 25 scans were acquired per patient. Using a state-of-the-art deformable registration algorithm, a set of the deformation vector fields (DVF) was generated to provide spatial mapping from the reference image geometry to the other free-breathing scans. These DVFs were used to generate Jacobian maps, which estimate voxelwise volume change. Subsequently, the set of 25 corresponding Jacobian and voxel intensity in Hounsfield units (HU) were collected and linear regression was performed based on the mass conservation relationship to correlate the volume change to density change. Based on the resulting fitting coefficients, the tissues were classified into parenchymal (Type I), vascular (Type II), and soft tissue (Type III) types. These coefficients modeled the voxelwise density variation during quiet breathing. The accuracy of the proposed method was assessed using mean absolute difference in HU between the CT scan intensities and the model predicted values. In addition, validation experiments employing a leave-five-out method were performed to evaluate the model accuracy. Results: The computed mean model errors were 23.30±9.54 HU, 29.31±10.67 HU, and 35.56±20.56 HU, respectively, for regions I, II, and III, respectively. The cross validation experiments averaged over 100 trials had mean errors of 30.02 ± 1.67 HU over the entire lung. These mean values were comparable with the estimated CT image background noise. Conclusion: The reported validation experiment statistics confirmed the lung density modeling during free breathing. The proposed technique was general and could be applied to a wide range of problem scenarios where accurate dynamic lung density information is needed

  9. Radiometric densimeter for measuring and automatic control of liquid density

    International Nuclear Information System (INIS)

    Wajs, J.

    1982-01-01

    A performance rule of the radiometric densimeter produced by ''POLON ''Works is presented. A simplified analysis of the correction of density indication changes due to liquid temperature variations is described. A method of replacing the measuring pipe carrying the liquid being measured by suitable standards is given. The method is for automatic systems control. (A.S.)

  10. Measurements of electron density profiles using an angular filter refractometer

    International Nuclear Information System (INIS)

    Haberberger, D.; Ivancic, S.; Hu, S. X.; Boni, R.; Barczys, M.; Craxton, R. S.; Froula, D. H.

    2014-01-01

    A novel diagnostic technique, angular filter refractometry (AFR), has been developed to characterize high-density, long-scale-length plasmas relevant to high-energy-density physics experiments. AFR measures plasma densities up to 10 21  cm −3 with a 263-nm probe laser and is used to study the plasma expansion from CH foil and spherical targets that are irradiated with ∼9 kJ of ultraviolet (351-nm) laser energy in a 2-ns pulse. The data elucidate the temporal evolution of the plasma profile for the CH planar targets and the dependence of the plasma profile on target radius for CH spheres

  11. Measurements of electron density profiles using an angular filter refractometer

    Energy Technology Data Exchange (ETDEWEB)

    Haberberger, D., E-mail: dhab@lle.rochester.edu; Ivancic, S.; Hu, S. X.; Boni, R.; Barczys, M.; Craxton, R. S.; Froula, D. H. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14636 (United States)

    2014-05-15

    A novel diagnostic technique, angular filter refractometry (AFR), has been developed to characterize high-density, long-scale-length plasmas relevant to high-energy-density physics experiments. AFR measures plasma densities up to 10{sup 21} cm{sup −3} with a 263-nm probe laser and is used to study the plasma expansion from CH foil and spherical targets that are irradiated with ∼9 kJ of ultraviolet (351-nm) laser energy in a 2-ns pulse. The data elucidate the temporal evolution of the plasma profile for the CH planar targets and the dependence of the plasma profile on target radius for CH spheres.

  12. Correlations between different methods of UO2 pellet density measurement

    International Nuclear Information System (INIS)

    Yanagisawa, Kazuaki

    1977-07-01

    Density of UO 2 pellets was measured by three different methods, i.e., geometrical, water-immersed and meta-xylene immersed and treated statistically, to find out the correlations between UO 2 pellets are of six kinds but with same specifications. The correlations are linear 1 : 1 for pellets of 95% theoretical densities and above, but such do not exist below the level and variated statistically due to interaction between open and close pores. (auth.)

  13. High-Sensitivity Measurement of Density by Magnetic Levitation.

    Science.gov (United States)

    Nemiroski, Alex; Kumar, A A; Soh, Siowling; Harburg, Daniel V; Yu, Hai-Dong; Whitesides, George M

    2016-03-01

    This paper presents methods that use Magnetic Levitation (MagLev) to measure very small differences in density of solid diamagnetic objects suspended in a paramagnetic medium. Previous work in this field has shown that, while it is a convenient method, standard MagLev (i.e., where the direction of magnetization and gravitational force are parallel) cannot resolve differences in density mm) because (i) objects close in density prevent each other from reaching an equilibrium height due to hard contact and excluded volume, and (ii) using weaker magnets or reducing the magnetic susceptibility of the medium destabilizes the magnetic trap. The present work investigates the use of weak magnetic gradients parallel to the faces of the magnets as a means of increasing the sensitivity of MagLev without destabilization. Configuring the MagLev device in a rotated state (i.e., where the direction of magnetization and gravitational force are perpendicular) relative to the standard configuration enables simple measurements along the axes with the highest sensitivity to changes in density. Manipulating the distance of separation between the magnets or the lengths of the magnets (along the axis of measurement) enables the sensitivity to be tuned. These modifications enable an improvement in the resolution up to 100-fold over the standard configuration, and measurements with resolution down to 10(-6) g/cm(3). Three examples of characterizing the small differences in density among samples of materials having ostensibly indistinguishable densities-Nylon spheres, PMMA spheres, and drug spheres-demonstrate the applicability of rotated Maglev to measuring the density of small (0.1-1 mm) objects with high sensitivity. This capability will be useful in materials science, separations, and quality control of manufactured objects.

  14. High-density Lipoproteins and Apolipoprotein A-I: Potential New Players in the Prevention and Treatment of Lung Disease

    Directory of Open Access Journals (Sweden)

    Elizabeth M. Gordon

    2016-09-01

    Full Text Available Apolipoprotein A-I (apoA-I and high-density lipoproteins (HDL mediate reverse cholesterol transport out of cells. Furthermore, HDL has additional protective functions, which include anti-oxidative, anti-inflammatory, anti-apoptotic, and vasoprotective effects. In contrast, HDL can become dysfunctional with a reduction in both cholesterol efflux and anti-inflammatory properties in the setting of disease or the acute phase response. These paradigms are increasingly being recognized to be active in the pulmonary system, where apoA-I and HDL have protective effects in normal lung health, as well as in a variety of disease states, including acute lung injury, asthma, chronic obstructive pulmonary disease, lung cancer, pulmonary arterial hypertension, pulmonary fibrosis, and viral pneumonia. Similar to observations in cardiovascular disease, however, HDL may become dysfunctional and contribute to disease pathogenesis in respiratory disorders. Furthermore, synthetic apoA-I mimetic peptides have been shown to have protective effects in animal models of acute lung injury, asthma, pulmonary hypertension, and influenza pneumonia. These findings provide evidence to support the concept that apoA-I mimetic peptides might be developed into a new treatment that can either prevent or attenuate the manifestations of lung diseases, such as asthma. Thus, the lung is positioned to take a page from the cardiovascular disease playbook and utilize the protective properties of HDL and apoA-I as a novel therapeutic approach.

  15. Measurement of temperature, electric conductivity and density of plasma

    International Nuclear Information System (INIS)

    Vasilevova, I.; Nefedov, A.; Oberman, F.; Urinson, A.

    1982-01-01

    Three instruments are briefly described developed by the High Temperatures Institute of the USSR Academy of Sciences for the measurement of plasma temperature, electric conductivity and density. The temperature measuring instrument uses as a standard a light source whose temperature may significantly differ from plasma temperature because three light fluxes are compared, namely the flux emitted by the plasma, the flux emitted directly by the standard source, and the flux emitted by the standard source after passage through the plasma. The results of measurement are computer processed. Electric conductivity is measured using a coil placed in a probe which is automatically extended for a time of maximally 0.3 seconds into the plasma stream. The equipment for measuring plasma density consists of a special single-channel monochromator, a temperature gauge, a plasma pressure gauge, and of a computer for processing the results of measurement. (Ha)

  16. WE-AB-207B-05: Correlation of Normal Lung Density Changes with Dose After Stereotactic Body Radiotherapy (SBRT) for Early Stage Lung Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Q; Devpura, S; Feghali, K; Liu, C; Ajlouni, M; Movsas, B; Chetty, I [Henry Ford Health System, Detroit, MI (United States)

    2016-06-15

    Purpose: To investigate correlation of normal lung CT density changes with dose accuracy and outcome after SBRT for patients with early stage lung cancer. Methods: Dose distributions for patients originally planned and treated using a 1-D pencil beam-based (PB-1D) dose algorithm were retrospectively recomputed using algorithms: 3-D pencil beam (PB-3D), and model-based Methods: AAA, Acuros XB (AXB), and Monte Carlo (MC). Prescription dose was 12 Gy × 4 fractions. Planning CT images were rigidly registered to the followup CT datasets at 6–9 months after treatment. Corresponding dose distributions were mapped from the planning to followup CT images. Following the method of Palma et al .(1–2), Hounsfield Unit (HU) changes in lung density in individual, 5 Gy, dose bins from 5–45 Gy were assessed in the peri-tumor region, defined as a uniform, 3 cm expansion around the ITV(1). Results: There is a 10–15% displacement of the high dose region (40–45 Gy) with the model-based algorithms, relative to the PB method, due to the electron scattering of dose away from the tumor into normal lung tissue (Fig.1). Consequently, the high-dose lung region falls within the 40–45 Gy dose range, causing an increase in HU change in this region, as predicted by model-based algorithms (Fig.2). The patient with the highest HU change (∼110) had mild radiation pneumonitis, and the patient with HU change of ∼80–90 had shortness of breath. No evidence of pneumonitis was observed for the 3 patients with smaller CT density changes (<50 HU). Changes in CT densities, and dose-response correlation, as computed with model-based algorithms, are in excellent agreement with the findings of Palma et al. (1–2). Conclusion: Dose computed with PB (1D or 3D) algorithms was poorly correlated with clinically relevant CT density changes, as opposed to model-based algorithms. A larger cohort of patients is needed to confirm these results. This work was supported in part by a grant from Varian

  17. Simulation of density measurements in plasma wakefields using photo acceleration

    CERN Document Server

    Kasim, Muhammad Firmansyah; Ceurvorst, Luke; Sadler, James; Burrows, Philip N; Trines, Raoul; Holloway, James; Wing, Matthew; Bingham, Robert; Norreys, Peter

    2015-01-01

    One obstacle in plasma accelerator development is the limitation of techniques to diagnose and measure plasma wakefield parameters. In this paper, we present a novel concept for the density measurement of a plasma wakefield using photon acceleration, supported by extensive particle in cell simulations of a laser pulse that copropagates with a wakefield. The technique can provide the perturbed electron density profile in the laser’s reference frame, averaged over the propagation length, to be accurate within 10%. We discuss the limitations that affect the measurement: small frequency changes, photon trapping, laser displacement, stimulated Raman scattering, and laser beam divergence. By considering these processes, one can determine the optimal parameters of the laser pulse and its propagation length. This new technique allows a characterization of the density perturbation within a plasma wakefield accelerator.

  18. Simulation of density measurements in plasma wakefields using photon acceleration

    Directory of Open Access Journals (Sweden)

    Muhammad Firmansyah Kasim

    2015-03-01

    Full Text Available One obstacle in plasma accelerator development is the limitation of techniques to diagnose and measure plasma wakefield parameters. In this paper, we present a novel concept for the density measurement of a plasma wakefield using photon acceleration, supported by extensive particle in cell simulations of a laser pulse that copropagates with a wakefield. The technique can provide the perturbed electron density profile in the laser’s reference frame, averaged over the propagation length, to be accurate within 10%. We discuss the limitations that affect the measurement: small frequency changes, photon trapping, laser displacement, stimulated Raman scattering, and laser beam divergence. By considering these processes, one can determine the optimal parameters of the laser pulse and its propagation length. This new technique allows a characterization of the density perturbation within a plasma wakefield accelerator.

  19. Electron density interferometry measurement in laser-matter interaction

    International Nuclear Information System (INIS)

    Popovics-Chenais, C.

    1981-05-01

    This work is concerned with the laser-interferometry measurement of the electronic density in the corona and the conduction zone external part. Particularly, it is aimed at showing up density gradients and at their space-time localization. The first chapter recalls the density profile influence on the absorption principal mechanisms and the laser energy transport. In chapter two, the numerical and analytical hydrodynamic models describing the density profile are analysed. The influence on the density profile of the ponderomotive force associated to high oscillating electric fields is studied, together with the limited thermal conduction and suprathermal electron population. The mechanism action, in our measurement conditions, is numerically simulated. Calculations are made with experimental parameters. The measurement interaction conditions, together with the diagnostic method by high resolution laser interferometry are detailed. The results are analysed with the help of numerical simulation which is the experiment modeling. An overview of the mechanisms shown up by interferometric measurements and their correlation with other diagnostics is the conclusion of this work [fr

  20. DAQ system for low density plasma parameters measurement

    International Nuclear Information System (INIS)

    Joshi, Rashmi S.; Gupta, Suryakant B.

    2015-01-01

    In various cases where low density plasmas (number density ranges from 1E4 to 1E6 cm -3 ) exist for example, basic plasma studies or LEO space environment measurement of plasma parameters becomes very critical. Conventional tip (cylindrical) Langmuir probes often result into unstable measurements in such lower density plasma. Due to larger surface area, a spherical Langmuir probe is used to measure such lower plasma densities. Applying a sweep voltage signal to the probe and measuring current values corresponding to these voltages gives V-I characteristics of plasma which can be plotted on a digital storage oscilloscope. This plot is analyzed for calculating various plasma parameters. The aim of this paper is to measure plasma parameters using a spherical Langmuir probe and indigenously developed DAQ system. DAQ system consists of Keithley source-meter and a host system connected by a GPIB interface. An online plasma parameter diagnostic system is developed for measuring plasma properties for non-thermal plasma in vacuum. An algorithm is developed using LabVIEW platform. V-I characteristics of plasma are plotted with respect to different filament current values and different locations of Langmuir probe with reference to plasma source. V-I characteristics is also plotted for forward and reverse voltage sweep generated programmatically from the source meter. (author)

  1. Outcomes of bone density measurements in coeliac disease.

    Science.gov (United States)

    Bolland, Mark J; Grey, Andrew; Rowbotham, David S

    2016-01-29

    Some guidelines recommend that patients with newly diagnosed coeliac disease undergo bone density scanning. We assessed the bone density results in a cohort of patients with coeliac disease. We searched bone density reports over two 5-year periods in all patients from Auckland District Health Board (2008-12) and in patients under 65 years from Counties Manukau District Health Board (2009-13) for the term 'coeliac.' Reports for 137 adults listed coeliac disease as an indication for bone densitometry. The average age was 47 years, body mass index (BMI) 25 kg/m(2), and 77% were female. The median time between coeliac disease diagnosis and bone densitometry was 261 days. The average bone density Z-score was slightly lower than expected (Z-score -0.3 to 0.4) at the lumbar spine, total hip and femoral neck, but 88-93% of Z-scores at each site lay within the normal range. Low bone density was strongly related to BMI: the proportions with Z-score 30 kg/m(2) were 28%, 15%, 6% and 0% respectively. Average bone density was normal, suggesting that bone density measurement is not indicated routinely in coeliac disease, but could be considered on a case-by-case basis for individuals with strong risk factors for fracture.

  2. Density and water content measurement with two dual detector probes

    International Nuclear Information System (INIS)

    Cariou, J.; Menard, J.

    1980-01-01

    The ''Laboratoires des Ponts et Chaussees'' have developed an electronic device for geological prospections. This system includes gamma-gamma and neutron-neutron probes for continuous measurement in borehole down to one hundred meters. It is used, as well to measure the density and the water content in the field of soil mechanic engineering. When the diameter is not constant all along the borehole the two probes have to use a dual detector procedure. When constant, a simple detector procedure is sufficient to obtain density and water content. Two examples show the possibilities of this apparatus, particularly to control the borehole diameter and the soil chemical composition [fr

  3. Methods and apparatus for measuring the density of geological formations

    International Nuclear Information System (INIS)

    Seeman, B.

    1975-01-01

    A tool for measuring the density of the geological formations traversed by a borehole is described. An apparatus corrects the effects of barite on the count rate of the pulses which are used for the density measurement and have an amplitude higher than a given threshold, by determining the deformations in the amplitude spectrum of these pulses and adjusting this threshold so as to compensate by the variation in the number of pulses taken into account, resulting from the adjustment for the variation in the number of counted pulses resulting from the said deformations

  4. Precision measurements of linear scattering density using muon tomography

    Science.gov (United States)

    Åström, E.; Bonomi, G.; Calliari, I.; Calvini, P.; Checchia, P.; Donzella, A.; Faraci, E.; Forsberg, F.; Gonella, F.; Hu, X.; Klinger, J.; Sundqvist Ökvist, L.; Pagano, D.; Rigoni, A.; Ramous, E.; Urbani, M.; Vanini, S.; Zenoni, A.; Zumerle, G.

    2016-07-01

    We demonstrate that muon tomography can be used to precisely measure the properties of various materials. The materials which have been considered have been extracted from an experimental blast furnace, including carbon (coke) and iron oxides, for which measurements of the linear scattering density relative to the mass density have been performed with an absolute precision of 10%. We report the procedures that are used in order to obtain such precision, and a discussion is presented to address the expected performance of the technique when applied to heavier materials. The results we obtain do not depend on the specific type of material considered and therefore they can be extended to any application.

  5. Agreement of mammographic measures of volumetric breast density to MRI.

    Directory of Open Access Journals (Sweden)

    Jeff Wang

    Full Text Available Clinical scores of mammographic breast density are highly subjective. Automated technologies for mammography exist to quantify breast density objectively, but the technique that most accurately measures the quantity of breast fibroglandular tissue is not known.To compare the agreement of three automated mammographic techniques for measuring volumetric breast density with a quantitative volumetric MRI-based technique in a screening population.Women were selected from the UCSF Medical Center screening population that had received both a screening MRI and digital mammogram within one year of each other, had Breast Imaging Reporting and Data System (BI-RADS assessments of normal or benign finding, and no history of breast cancer or surgery. Agreement was assessed of three mammographic techniques (Single-energy X-ray Absorptiometry [SXA], Quantra, and Volpara with MRI for percent fibroglandular tissue volume, absolute fibroglandular tissue volume, and total breast volume.Among 99 women, the automated mammographic density techniques were correlated with MRI measures with R(2 values ranging from 0.40 (log fibroglandular volume to 0.91 (total breast volume. Substantial agreement measured by kappa statistic was found between all percent fibroglandular tissue measures (0.72 to 0.63, but only moderate agreement for log fibroglandular volumes. The kappa statistics for all percent density measures were highest in the comparisons of the SXA and MRI results. The largest error source between MRI and the mammography techniques was found to be differences in measures of total breast volume.Automated volumetric fibroglandular tissue measures from screening digital mammograms were in substantial agreement with MRI and if associated with breast cancer could be used in clinical practice to enhance risk assessment and prevention.

  6. Agreement of mammographic measures of volumetric breast density to MRI.

    Science.gov (United States)

    Wang, Jeff; Azziz, Ania; Fan, Bo; Malkov, Serghei; Klifa, Catherine; Newitt, David; Yitta, Silaja; Hylton, Nola; Kerlikowske, Karla; Shepherd, John A

    2013-01-01

    Clinical scores of mammographic breast density are highly subjective. Automated technologies for mammography exist to quantify breast density objectively, but the technique that most accurately measures the quantity of breast fibroglandular tissue is not known. To compare the agreement of three automated mammographic techniques for measuring volumetric breast density with a quantitative volumetric MRI-based technique in a screening population. Women were selected from the UCSF Medical Center screening population that had received both a screening MRI and digital mammogram within one year of each other, had Breast Imaging Reporting and Data System (BI-RADS) assessments of normal or benign finding, and no history of breast cancer or surgery. Agreement was assessed of three mammographic techniques (Single-energy X-ray Absorptiometry [SXA], Quantra, and Volpara) with MRI for percent fibroglandular tissue volume, absolute fibroglandular tissue volume, and total breast volume. Among 99 women, the automated mammographic density techniques were correlated with MRI measures with R(2) values ranging from 0.40 (log fibroglandular volume) to 0.91 (total breast volume). Substantial agreement measured by kappa statistic was found between all percent fibroglandular tissue measures (0.72 to 0.63), but only moderate agreement for log fibroglandular volumes. The kappa statistics for all percent density measures were highest in the comparisons of the SXA and MRI results. The largest error source between MRI and the mammography techniques was found to be differences in measures of total breast volume. Automated volumetric fibroglandular tissue measures from screening digital mammograms were in substantial agreement with MRI and if associated with breast cancer could be used in clinical practice to enhance risk assessment and prevention.

  7. Electron density measurements during ion beam transport on Gamble II

    International Nuclear Information System (INIS)

    Weber, B.V.; Hinshelwood, D.D.; Neri, J.M.; Ottinger, P.F.; Rose, D.V.; Stephanakis, S.J.; Young, F.C.

    1999-01-01

    High-sensitivity laser interferometry was used to measure the electron density created when an intense proton beam (100 kA, 1 MeV, 50 ns) from the Gamble II generator was transported through low-pressure gas as part of a project investigating Self-Pinched Transport (SPT) of intense ion beams. This measurement is non-perturbing and sufficiently quantitative to allow benchmarking of codes (particularly IPROP) used to model beam-gas interaction and ion-beam transport. Very high phase sensitivity is required for this measurement. For example, a 100-kA, 1-MeV, 10-cm-radius proton beam with uniform current density has a line-integrated proton density equal to n b L = 3 x 10 13 cm -2 . An equal electron line-density, n e L = n b L, (expected for transport in vacuum) will be detected as a phase shift of the 1.064 microm laser beam of only 0.05degree, or an optical path change of 1.4 x 10 -4 waves (about the size of a hydrogen atom). The time-history of the line-integrated electron density, measured across a diameter of the transport chamber at 43 cm from the input aperture, starts with the proton arrival time and decays differently depending on the gas pressure. The gas conditions included vacuum (10 -4 Torr air), 30 to 220 mTorr He, and 1 Torr air. The measured densities vary by three orders of magnitude, from 10 13 to 10 16 cm -2 for the range of gas pressures investigated. In vacuum, the measured electron densities indicate only co-moving electrons (n e L approximately n b L). In He, when the gas pressure is sufficient for ionization by beam particles and SPT is observed, n e L increases to about 10 n b L. At even higher pressures where electrons contribute to ionization, even higher electron densities are observed with an ionization fraction of about 2%. The diagnostic technique as used on the SPT experiment will be described and a summary of the results will be given. The measurements are in reasonable agreement with theoretical predictions from the IPROP code

  8. Density of asphalt paving mixtures: Measurements, variations, and influencing factors

    International Nuclear Information System (INIS)

    Solaimanian, M.

    1990-01-01

    The first part describes the results of a research study to determine the effectiveness of the Troxler Model 4640 Thin Lift Nuclear Density Gauge. The densities obtained from cores and the nuclear density gauge from seven construction projects were compared. A linear regression technique was used to investigate how well the core densities could be predicted from nuclear densities. Correlation coefficients were determined to indicate the degree of correlation between the core and nuclear densities. Using a statistical analysis technique, the range of differences between core and nuclear measurements was established for specified confidence levels for each project. Analysis of the data indicated that the accuracy of this gauge is highly material dependent. While acceptable results were obtained with limestone mixtures, the gauge did not perform satisfactorily with mixtures containing siliceous aggregate. The data presented in this paper indicate that the gauge could be used as a quality control tool provided that a calibration is developed for each project. The maximum theoretical specific gravities of asphalt-aggregate paving mixtures obtained from different methods were compared. The study included experimental work and analysis of the resulting data. The agreement between results obtained from the Texas C-14 method and the Rice method were excellent. Results obtained by backcalculating theoretical maximum densities from a single Rice test were also found to be satisfactory. Theoretical approach based on bulk specific gravity of aggregate is not recommended because of yielding significantly low theoretical maximum specific gravities and high relative densities. The last two parts summarize density levels and corresponding variations obtained from fifty-seven construction projects throughout the state of Texas

  9. Urinary density measurement and analysis methods in neonatal unit care

    Directory of Open Access Journals (Sweden)

    Maria Vera Lúcia Moreira Leitão Cardoso

    2013-09-01

    Full Text Available The objective was to assess urine collection methods through cotton in contact with genitalia and urinary collector to measure urinary density in newborns. This is a quantitative intervention study carried out in a neonatal unit of Fortaleza-CE, Brazil, in 2010. The sample consisted of 61 newborns randomly chosen to compose the study group. Most neonates were full term (31/50.8% males (33/54%. Data on urinary density measurement through the methods of cotton and collector presented statistically significant differences (p<0.05. The analysis of interquartile ranges between subgroups resulted in statistical differences between urinary collector/reagent strip (1005 and cotton/reagent strip (1010, however there was no difference between urinary collector/ refractometer (1008 and cotton/ refractometer. Therefore, further research should be conducted with larger sampling using methods investigated in this study and whenever possible, comparing urine density values to laboratory tests.

  10. Measurement of radon concentration in dwellings in the region of highest lung cancer incidence in India

    International Nuclear Information System (INIS)

    Zoliana, B.; Rohmingliana, P.C.; Sahoo, B.K.; Mayya, Y.S.

    2015-01-01

    Monitoring of radon exhalation from soil and its concentration in indoor is found to be helpful in many investigations such as health risk assessment and others as radiation damage to bronchial cells which eventually can be the second leading cause of lung cancer next to smoking. The fact that Aizawl District, Mizoram, India has the highest lung cancer incidence rates among males and females in Age Adjusted Rate (AAR) in India as declared by Population Based Cancer Registry Report 2008 indicates the need for quantification of radon and its anomalies attached to it. Measurement of radon concentration had been carried out inside the dwellings in Aizawl district, Mizoram. A time integrated method of measurement was employed by using a solid state nuclear track detector (SSNTD) type (LR-115 films) kept in a twin cup dosimeter for measurement of concentration of radon and thoron. The dosimeters were suspended over bed rooms or living rooms in selected dwellings. They were deployed for a period of about 120 days at a time in 63 houses which were selected according to their place of location viz. fault region, places where fossil remains were found and geologically unidentified region. After the desired period of exposure, the detectors were retrieved and chemically etched which were then counted by using a spark counter. The recorded nuclear tract densities are then converted into air concentrations of Radon and Thoron

  11. A pilot study examining density of suppression measurement in strabismus.

    Science.gov (United States)

    Piano, Marianne; Newsham, David

    2015-01-01

    Establish whether the Sbisa bar, Bagolini filter (BF) bar, and neutral density filter (NDF) bar, used to measure density of suppression, are equivalent and possess test-retest reliability. Determine whether density of suppression is altered when measurement equipment/testing conditions are changed. Our pilot study had 10 subjects aged ≥18 years with childhood-onset strabismus, no ocular pathologies, and no binocular vision when manifest. Density of suppression upon repeated testing, with clinic lights on/off, and using a full/reduced intensity light source, was investigated. Results were analysed for test-retest reliability, equivalence, and changes with alteration of testing conditions. Test-retest reliability issues were present for the BF bar (median 6 filter change from first to final test, p = 0.021) and NDF bar (median 5 filter change from first to final test, p = 0.002). Density of suppression was unaffected by environmental illumination or fixation light intensity variations. Density of suppression measurements were higher when measured with the NDF bar (e.g. NDF bar = 1.5, medium suppression, vs BF bar = 6.5, light suppression). Test-retest reliability issues may be present for the two filter bars currently still under manufacture. Changes in testing conditions do not significantly affect test results, provided the same filter bar is used consistently for testing. Further studies in children with strabismus having active amblyopia treatment would be of benefit. Despite extensive use of these tests in the UK, this is to our knowledge the first study evaluating filter bar equivalence/reliability.

  12. Measurement of simulated lung deposition of radon daughters

    International Nuclear Information System (INIS)

    Jonassen, N.; Jensen, B.

    1992-01-01

    A measurement system for the lung deposition of radon daughters based on respiratory models was suggested by Hopke et al. By choosing suitable mesh size and flow velocities it is possible to design a multiple-wire screen sampler simulating deposition in the respiratory tract of aerosols over the size range 0.5-1000 nm. This paper describes a preliminary investigation where simulated deposition in the nasal tract and in the bronchii (for mouth breathing as well as nasal breathing) is determined. The measurements were performed in atmospheres where the normalised exposure rate (equilibrium factor) was varied by changing the aerosol loading of the air as well as by enhanced electrostatic plateout. The general results of the measurements are that the energy deposited in the nose with nasal breathing and in the bronchii with mouth breathing varies as the calculated dose while the energy deposited in the bronchii with nasal breathing follows the exposure. It is also demonstrated that the energy deposited for a fixed value of the radon concentration may vary by a factor of 2-7 depending on the treatment of the air. (author)

  13. Coupling two iteratives algorithms for density measurements by computerized tomography

    International Nuclear Information System (INIS)

    Silva, L.E.M.C.; Santos, C.A.C.; Borges, J.C.; Frenkel, A.D.B.; Rocha, G.M.

    1986-01-01

    This work develops a study for coupling two iteratives algotithms for density measurements by computerized tomography. Tomographies have been obtained with an automatized prototype, controled by a microcomputer, projected and assembled in the Nuclear Instrumentation Laboratory, at COPPE/UFRJ. Results show a good performance of the tomographic system, and demonstrate the validity of the method of calculus adopted. (Author) [pt

  14. Measurements of plasma temperature and electron density in laser

    Indian Academy of Sciences (India)

    The temperature and electron density characterizing the plasma are measured by time-resolved spectroscopy of neutral atom and ion line emissions in the time window of 300–2000 ns. An echelle spectrograph coupled with a gated intensified charge coupled detector is used to record the plasma emissions.

  15. Electron density measurement in an evolving plasma. Experimental devices

    International Nuclear Information System (INIS)

    Consoli, Terenzio; Dagai, Michel

    1960-01-01

    The experimental devices described here allow the electron density measurements in the 10 16 e/m 3 to 10 20 e/m 3 interval. Reprint of a paper published in Comptes rendus des seances de l'Academie des Sciences, t. 250, p. 1223-1225, sitting of 15 February 1960 [fr

  16. Device for measuring neutron-flux distribution density

    International Nuclear Information System (INIS)

    Rozenbljum, N.D.; Mitelman, M.G.; Kononovich, A.A.; Kirsanov, V.S.; Zagadkin, V.A.

    1977-01-01

    An arrangement is described for measuring the distribution of neutron flux density over the height of a nuclear reactor core and which may be used for monitoring energy release or for detecting deviations of neutron flux from an optimal level so that subsequent balance can be achieved. It avoids mutual interference of detectors. Full constructional details are given. (UK)

  17. Improved density measurement by FIR laser interferometer on EAST tokamak

    International Nuclear Information System (INIS)

    Shen, Jie; Jie, Yinxian; Liu, Haiqing; Wei, Xuechao; Wang, Zhengxing; Gao, Xiang

    2013-01-01

    Highlights: • In 2012, the water-cooling Mo wall was installed in EAST. • A schottky barrier diode detector is designed and used on EAST for the first time. • The three-channel far-infrared laser interferometer can measure the electron density. • The improved measurement and latest experiment results are reported. • The signal we get in this experiment campaign is much better than we got in 2010. -- Abstract: A three-channel far-infrared (FIR) hydrogen cyanide (HCN) laser interferometer is in operation since 2010 to measure the line averaged electron density on experimental advanced superconducting tokamak (EAST). The HCN laser signal is improved by means of a new schottky barrier diode (SBD) detector. The improved measurement and latest experiment results of the three-channel FIR laser interferometer on EAST tokamak are reported

  18. Improved density measurement by FIR laser interferometer on EAST tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Jie, E-mail: shenjie1988@ipp.ac.cn; Jie, Yinxian; Liu, Haiqing; Wei, Xuechao; Wang, Zhengxing; Gao, Xiang

    2013-11-15

    Highlights: • In 2012, the water-cooling Mo wall was installed in EAST. • A schottky barrier diode detector is designed and used on EAST for the first time. • The three-channel far-infrared laser interferometer can measure the electron density. • The improved measurement and latest experiment results are reported. • The signal we get in this experiment campaign is much better than we got in 2010. -- Abstract: A three-channel far-infrared (FIR) hydrogen cyanide (HCN) laser interferometer is in operation since 2010 to measure the line averaged electron density on experimental advanced superconducting tokamak (EAST). The HCN laser signal is improved by means of a new schottky barrier diode (SBD) detector. The improved measurement and latest experiment results of the three-channel FIR laser interferometer on EAST tokamak are reported.

  19. Density measurement using gamma radiation - theory and application

    International Nuclear Information System (INIS)

    Springer, E.K.

    1979-01-01

    There are still widespread uncertainties about the use and safety of gamma radiation in industries. This paper describes, by the example of radiometric density measurement, the theory of gamma radiation. The differences and advantages of both types of detectors, the ionization chamber and the scintillation counter, are discussed. The degree of accuracy which can be expected from the radiometric density meter will be defined, and the inter-relationship: source strength - measuring range - measuring length(normally the pipe diameter) in relation to the measuring accuracy required will be explained in detail. The use of radioactive material requires the permission of the Atomic Energy Board. The formalities involved to receive a user's licence and the implementations of safety standards set by the local authorities are discussed in depth [af

  20. Measurement of histamine release from human lung tissue ex vivo by microdialysis technique

    DEFF Research Database (Denmark)

    Nissen, Dan; Petersen, Lars Jelstrup; Nolte, H

    1998-01-01

    OBJECTIVE AND DESIGN: Currently no method is available for measurement of mediator release from intact human lung. In this study, a microdialysis technique was used to measure histamine release from mast cells in human lung tissue ex vivo. MATERIAL: Microdialysis fibers of 216 microm were inserted...... responses were observed but data could be reproduced within individual donors. Monocyte chemoattractant protein-1, a potent basophil secretagogue, did not induce histamine release in lung tissue which indicated mast cells to be the histamine source. Substance P did not release histamine in the lung tissue....... CONCLUSIONS: The microdialysis technique allowed measurements of histamine release from mast cells in intact lung ex vivo. The method may prove useful since a number of experiments can be performed in a few hours in intact lung tissue without any dispersion or enzymatic treatment....

  1. Relationship of the Functional Movement Screen In-Line Lunge to Power, Speed, and Balance Measures

    Science.gov (United States)

    Hartigan, Erin H.; Lawrence, Michael; Bisson, Brian M.; Torgerson, Erik; Knight, Ryan C.

    2014-01-01

    Background: The in-line lunge of the Functional Movement Screen (FMS) evaluates lateral stability, balance, and movement asymmetries. Athletes who score poorly on the in-line lunge should avoid activities requiring power or speed until scores are improved, yet relationships between the in-line lunge scores and other measures of balance, power, and speed are unknown. Hypothesis: (1) Lunge scores will correlate with center of pressure (COP), maximum jump height (MJH), and 36.6-meter sprint time and (2) there will be no differences between limbs on lunge scores, MJH, or COP. Study Design: Descriptive laboratory study. Level of Evidence: Level 3. Methods: Thirty-seven healthy, active participants completed the first 3 tasks of the FMS (eg, deep squat, hurdle step, in-line lunge), unilateral drop jumps, and 36.6-meter sprints. A 3-dimensional motion analysis system captured MJH. Force platforms measured COP excursion. A laser timing system measured 36.6-m sprint time. Statistical analyses were used to determine whether a relationship existed between lunge scores and COP, MJH, and 36.6-m speed (Spearman rho tests) and whether differences existed between limbs in lunge scores (Wilcoxon signed-rank test), MJH, and COP (paired t tests). Results: Lunge scores were not significantly correlated with COP, MJH, or 36.6-m sprint time. Lunge scores, COP excursion, and MJH were not statistically different between limbs. Conclusion: Performance on the FMS in-line lunge was not related to balance, power, or speed. Healthy participants were symmetrical in lunging measures and MJH. Clinical Relevance: Scores on the FMS in-line lunge should not be attributed to power, speed, or balance performance without further examination. However, assessing limb symmetry appears to be clinically relevant. PMID:24790688

  2. Relationship of the functional movement screen in-line lunge to power, speed, and balance measures.

    Science.gov (United States)

    Hartigan, Erin H; Lawrence, Michael; Bisson, Brian M; Torgerson, Erik; Knight, Ryan C

    2014-05-01

    The in-line lunge of the Functional Movement Screen (FMS) evaluates lateral stability, balance, and movement asymmetries. Athletes who score poorly on the in-line lunge should avoid activities requiring power or speed until scores are improved, yet relationships between the in-line lunge scores and other measures of balance, power, and speed are unknown. (1) Lunge scores will correlate with center of pressure (COP), maximum jump height (MJH), and 36.6-meter sprint time and (2) there will be no differences between limbs on lunge scores, MJH, or COP. Descriptive laboratory study. Level 3. Thirty-seven healthy, active participants completed the first 3 tasks of the FMS (eg, deep squat, hurdle step, in-line lunge), unilateral drop jumps, and 36.6-meter sprints. A 3-dimensional motion analysis system captured MJH. Force platforms measured COP excursion. A laser timing system measured 36.6-m sprint time. Statistical analyses were used to determine whether a relationship existed between lunge scores and COP, MJH, and 36.6-m speed (Spearman rho tests) and whether differences existed between limbs in lunge scores (Wilcoxon signed-rank test), MJH, and COP (paired t tests). Lunge scores were not significantly correlated with COP, MJH, or 36.6-m sprint time. Lunge scores, COP excursion, and MJH were not statistically different between limbs. Performance on the FMS in-line lunge was not related to balance, power, or speed. Healthy participants were symmetrical in lunging measures and MJH. Scores on the FMS in-line lunge should not be attributed to power, speed, or balance performance without further examination. However, assessing limb symmetry appears to be clinically relevant.

  3. Grain bulk density measurement based on wireless network

    Directory of Open Access Journals (Sweden)

    Wu Fangming

    2017-01-01

    Full Text Available To know the accurate quantity of stored grain, grain density sensors must be used to measure the grain’s bulk density. However, multi-sensors should be inserted into the storage facility, to quickly collect data during the inventory checking of stored grain. In this study, the ZigBee and Wi-Fi coexistence network’s ability to transmit data collected by density sensors was investigated. A system consisting of six sensor nodes, six router nodes, one gateway and one Android Pad was assembled to measure the grain’s bulk density and calculate its quantity. The CC2530 chip with ZigBee technology was considered as the core of the information processing, and wireless nodes detection in sensor, and router nodes. ZigBee worked in difference signal channel with Wi-Fi to avoid interferences and connected with Wi-Fi module by UART serial communications interfaces in gateway. The Android Pad received the measured data through the gateway and processed this data to calculate quantity. The system enabled multi-point and real-time parameter detection inside the grain storage. Results show that the system has characteristics of good expansibility, networking flexibility and convenience.

  4. Density and volume measurements of reprocessing plant feed

    International Nuclear Information System (INIS)

    Platzer, R.; Carrier, M.; Neuilly, M.; Dedaldechamp, P.

    1985-05-01

    A theoretical study of the phenomenon of gas bubbles formation within a liquid led to an adaptation of the differential pressure bubbling technique for the measurement of liquid levels and densities in tanks. Experiments, carried out on a 800 liters tank with water and uranyl nitrate solutions had the double aim to study the precision attainable on volume and density measurements and to design a method for corrections of influencing factors. In parallel, procedures for transfer of known volumes through the use of siphons and for tank calibration by liquid level measurement are also investigated. The paper presents the first results obtained so far and the conclusions to be drawn for the elaboration of calibration and exploitation procedures suitables for use in reprocessing plants. The demonstration to transfer mass of solution with an accuracy of 0.1% is made [fr

  5. Conservative surgery and radiotherapy for early-stage breast cancer using a lung density correction: the University of Michigan experience

    International Nuclear Information System (INIS)

    Pierce, Lori J.; Strawderman, Myla H.; Douglas, Kathye R.; Lichter, Allen S.

    1997-01-01

    Purpose: Although an abundance of reports detail the successful use of definitive radiotherapy of the breast in the treatment in Stage I or II breast cancer, little data have been published concerning the use of lung density correction and its effect upon long-term outcome. As it has been the practice at the University of Michigan to routinely use lung density correction in the dose calculations to the breast, we retrospectively analyzed our results for local control, relapse-free, and overall survival. Methods and Materials: Clinical records were reviewed of 429 women with Stage I or II breast cancer treated with lumpectomy, axillary dissection, and breast irradiation with or without systemic chemo/hormonal therapy. Tangential radiotherapy fields delivering 45 to 50 Gy were used to treat the entire breast. A boost was delivered in 95% of cases for a total tumor bed dose of 60 to 66 Gy. All treatment plans were calculated using a lung density correction. Results: With a median follow up of 4.4 years, the 5-year actuarial rate of local control with local failure as the only site of first failure was 96% (95% CI 94-98%). Univariate analysis for local failure as only first failure found the following factors to statistically predict for increased risk of breast recurrence: young age (≤35 years old), premenopausal status, tumor size >2 cm, positive family history, and positive microscopic margins. Multivariate analysis revealed young age and margin status to be the only factors remaining significant for local failure. The 5-year actuarial relapse-free survival was 85% (95% CI 81-89%); overall survival at 5 years was 90% (95% CI 87-94%). Conclusions: Lung density correction results in rates of local control, disease-free, and overall survival at 5 years that compare favorably with series using noncorrected unit density calculations. While we will continue to update our results with increasing follow-up, our 5-year data indicate that the use of lung-density correction

  6. Ventilation inhomogeneity in obstructive lung diseases measured by electrical impedance tomography: a simulation study.

    Science.gov (United States)

    Schullcke, B; Krueger-Ziolek, S; Gong, B; Jörres, R A; Mueller-Lisse, U; Moeller, K

    2017-10-10

    Electrical impedance tomography (EIT) has mostly been used in the Intensive Care Unit (ICU) to monitor ventilation distribution but is also promising for the diagnosis in spontaneously breathing patients with obstructive lung diseases. Beside tomographic images, several numerical measures have been proposed to quantitatively assess the lung state. In this study two common measures, the 'Global Inhomogeneity Index' and the 'Coefficient of Variation' were compared regarding their capability to reflect the severity of lung obstruction. A three-dimensional simulation model was used to simulate obstructed lungs, whereby images were reconstructed on a two-dimensional domain. Simulations revealed that minor obstructions are not adequately recognized in the reconstructed images and that obstruction above and below the electrode plane may result in misleading values of inhomogeneity measures. EIT measurements on several electrode planes are necessary to apply these measures in patients with obstructive lung diseases in a promising manner.

  7. Cross-sectional changes in lung volume measured by electrical impedance tomography are representative for the whole lung in ventilated preterm infants

    NARCIS (Netherlands)

    van der Burg, Pauline S.; Miedema, Martijn; de Jongh, Franciscus H.C.; Frerichs, Inez; van Kaam, Anton H.

    2014-01-01

    Objective: Electrical impedance tomography measures lung volume in a cross-sectional slice of the lung. Whether these cross-sectional volume changes are representative of the whole lung has only been investigated in adults, showing conflicting results. This study aimed to compare cross-sectional and

  8. Cumulative sum quality control for calibrated breast density measurements

    International Nuclear Information System (INIS)

    Heine, John J.; Cao Ke; Beam, Craig

    2009-01-01

    Purpose: Breast density is a significant breast cancer risk factor. Although various methods are used to estimate breast density, there is no standard measurement for this important factor. The authors are developing a breast density standardization method for use in full field digital mammography (FFDM). The approach calibrates for interpatient acquisition technique differences. The calibration produces a normalized breast density pixel value scale. The method relies on first generating a baseline (BL) calibration dataset, which required extensive phantom imaging. Standardizing prospective mammograms with calibration data generated in the past could introduce unanticipated error in the standardized output if the calibration dataset is no longer valid. Methods: Sample points from the BL calibration dataset were imaged approximately biweekly over an extended timeframe. These serial samples were used to evaluate the BL dataset reproducibility and quantify the serial calibration accuracy. The cumulative sum (Cusum) quality control method was used to evaluate the serial sampling. Results: There is considerable drift in the serial sample points from the BL calibration dataset that is x-ray beam dependent. Systematic deviation from the BL dataset caused significant calibration errors. This system drift was not captured with routine system quality control measures. Cusum analysis indicated that the drift is a sign of system wear and eventual x-ray tube failure. Conclusions: The BL calibration dataset must be monitored and periodically updated, when necessary, to account for sustained system variations to maintain the calibration accuracy.

  9. Cumulative sum quality control for calibrated breast density measurements

    Energy Technology Data Exchange (ETDEWEB)

    Heine, John J.; Cao Ke; Beam, Craig [Cancer Prevention and Control Division, Moffitt Cancer Center, 12902 Magnolia Drive, Tampa, Florida 33612 (United States); Division of Epidemiology and Biostatistics, School of Public Health, University of Illinois at Chicago, 1603 W. Taylor St., Chicago, Illinois 60612 (United States)

    2009-12-15

    Purpose: Breast density is a significant breast cancer risk factor. Although various methods are used to estimate breast density, there is no standard measurement for this important factor. The authors are developing a breast density standardization method for use in full field digital mammography (FFDM). The approach calibrates for interpatient acquisition technique differences. The calibration produces a normalized breast density pixel value scale. The method relies on first generating a baseline (BL) calibration dataset, which required extensive phantom imaging. Standardizing prospective mammograms with calibration data generated in the past could introduce unanticipated error in the standardized output if the calibration dataset is no longer valid. Methods: Sample points from the BL calibration dataset were imaged approximately biweekly over an extended timeframe. These serial samples were used to evaluate the BL dataset reproducibility and quantify the serial calibration accuracy. The cumulative sum (Cusum) quality control method was used to evaluate the serial sampling. Results: There is considerable drift in the serial sample points from the BL calibration dataset that is x-ray beam dependent. Systematic deviation from the BL dataset caused significant calibration errors. This system drift was not captured with routine system quality control measures. Cusum analysis indicated that the drift is a sign of system wear and eventual x-ray tube failure. Conclusions: The BL calibration dataset must be monitored and periodically updated, when necessary, to account for sustained system variations to maintain the calibration accuracy.

  10. Pulse compression radar reflectometry for density measurements on fusion plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Costley, A; Prentice, R [Commission of the European Communities, Abingdon (United Kingdom). JET Joint Undertaking; Laviron, C [Compagnie Generale des Matieres Nucleaires (COGEMA), 78 - Velizy-Villacoublay (France); Prentice, R [Toulouse-3 Univ., 31 (France). Centre d` Etude Spatiale des Rayonnements

    1994-07-01

    On tokamaks and other toroidal machines, reflectometry is a very rapidly developing technique for density profile measurements, particularly near the edge. Its principle relies on the total reflection of an electromagnetic wave at a cutoff layer, where the critical density is reached and the local refractive index goes to zero. With the new fast frequency synthesizers now available, a method based on pulse compression radar is proposed for plasma reflectometry, overcoming the limitations of the previous reflectometry methods. The measurement can be made on a time-scale which is effectively very short relatively to the plasma fluctuations, and the very high reproducibility and stability of the source allows an absolute calibration of the waveguides to be made, which corrects for the effects of the parasitic reflections. 2 refs., 5 figs.

  11. Plasma density measurement with ring-type cutoff probe

    International Nuclear Information System (INIS)

    Kim, D.W.; You, S.J.; Na, B.K.; Kim, J.H.; Shin, Y.H.; Chang, H.Y.; Oh, W.Y.

    2013-01-01

    We proposed a cutoff probe with a ring-type detection tip enclosing a bar-type radiation tip. A comparative study between a proposed ring-type cutoff (RTC) probe and a conventional bar-type cutoff (BTC) probe showed that the RTC probe solved the problem of the BTC probe, the large measurement uncertainty of the electron density in a capacitively coupled plasma source. This improved characteristics of the RTC probe might have originated from the geometrical structure of the RTC probe concerning the monopole antennae radiation. This proposed cutoff probe can be expected to expand the applicable diagnostic range and to enhance the sensitivity of the cutoff probe. - Highlights: ► A cutoff probe with a ring type detection tip is proposed. ► Comparative experiment and simulation were conducted. ► The proposed probe showed a small uncertainty of measured plasma density. ► Improved characteristics might be originated from the geometrical structure

  12. Comparison of manual and automated size measurements of lung metastases on MDCT images: Potential influence on therapeutic decisions

    Energy Technology Data Exchange (ETDEWEB)

    Pauls, Sandra [Department of Diagnostic and Interventional Radiology, University of Ulm, Robert-Koch-Strasse 8, 89081 Ulm (Germany)], E-mail: sandra.pauls@uni-ulm.de; Kuerschner, Christian [Department of Diagnostic and Interventional Radiology, University of Ulm, Robert-Koch-Strasse 8, 89081 Ulm (Germany)], E-mail: chris.kuerschner@web.de; Dharaiya, Ekta [CT-Clinical Science, Philips Medical Systems, Highland Heights, OH 44143 (United States)], E-mail: ekta.shah@philips.com; Muche, Rainer [Institute of Biometrics, University of Ulm, Schwabstrasse 13, 89075 Ulm (Germany)], E-mail: rainer.muche@uni-ulm.de; Schmidt, Stefan A. [Department of Diagnostic and Interventional Radiology, University of Ulm, Robert-Koch-Strasse 8, 89081 Ulm (Germany)], E-mail: stefan-a.schmidt@gmx.de; Krueger, Stefan [Department of Internal Medicine II, University of Ulm, Robert-Koch-Strasse 8, 89081 Ulm (Germany)], E-mail: s.krueger@uniklinik-ulm.de; Brambs, Hans-Juergen [Department of Diagnostic and Interventional Radiology, University of Ulm, Robert-Koch-Strasse 8, 89081 Ulm (Germany)], E-mail: hans-juergen.brambs@uniklinik-ulm.de; Aschoff, Andrik J. [Department of Diagnostic and Interventional Radiology, University of Ulm, Robert-Koch-Strasse 8, 89081 Ulm (Germany)], E-mail: andrik.aschoff@uni-ulm.de

    2008-04-15

    Purpose: The goal of this study was to evaluate the influence of automated measurement of diameter, area, and volume from chest CT scans on therapeutic decisions of lung nodules as compared to manual 2-D measurements. Patients and method: The retrospective study involved 25 patients with 75 lung metastases. Contrast enhanced CT scans (16 row) of the lung were performed three times during chemotherapy with a mean time interval of 67.9 days between scans. In each patient, three metastases were evaluated (n = 225). Automatic measurements were compared to manual assessment for the following parameters: diameter, area, and density. The influence on the therapeutic decisions was evaluated using the RECIST criteria. Results: The maximum diameter measured by the automatic application was on an average 27% (S.D. 39; CI: 0.22-0.32; p < 0.0001) higher than the maximum diameter with manual assessment, and the differences depended on metastases size. Based on diameter calculation, manual and automated assessment disagreed in up to 32% of therapeutic decisions. Volumetric assessment tended towards more changes in therapy as compared to diameter calculation. The calculation of mean transversal area of metastases was 36% (S.D. 0.305; CI: -0.40 to -0.32; p < 0.0001) less with automated measurement. Therapeutic strategy would be changed in up to 25.7% of nodules using automated area calculation. Automated assessment of nodules' area and volume could influence the therapeutic decisions in up to 51.4% of all nodules. Density of the nodules was not validated to determine the influence on therapeutic decisions. Conclusion: There is a discrepancy between the manual and automated size measurement of lung metastases which could be significant.

  13. Comparison of manual and automated size measurements of lung metastases on MDCT images: Potential influence on therapeutic decisions

    International Nuclear Information System (INIS)

    Pauls, Sandra; Kuerschner, Christian; Dharaiya, Ekta; Muche, Rainer; Schmidt, Stefan A.; Krueger, Stefan; Brambs, Hans-Juergen; Aschoff, Andrik J.

    2008-01-01

    Purpose: The goal of this study was to evaluate the influence of automated measurement of diameter, area, and volume from chest CT scans on therapeutic decisions of lung nodules as compared to manual 2-D measurements. Patients and method: The retrospective study involved 25 patients with 75 lung metastases. Contrast enhanced CT scans (16 row) of the lung were performed three times during chemotherapy with a mean time interval of 67.9 days between scans. In each patient, three metastases were evaluated (n = 225). Automatic measurements were compared to manual assessment for the following parameters: diameter, area, and density. The influence on the therapeutic decisions was evaluated using the RECIST criteria. Results: The maximum diameter measured by the automatic application was on an average 27% (S.D. 39; CI: 0.22-0.32; p < 0.0001) higher than the maximum diameter with manual assessment, and the differences depended on metastases size. Based on diameter calculation, manual and automated assessment disagreed in up to 32% of therapeutic decisions. Volumetric assessment tended towards more changes in therapy as compared to diameter calculation. The calculation of mean transversal area of metastases was 36% (S.D. 0.305; CI: -0.40 to -0.32; p < 0.0001) less with automated measurement. Therapeutic strategy would be changed in up to 25.7% of nodules using automated area calculation. Automated assessment of nodules' area and volume could influence the therapeutic decisions in up to 51.4% of all nodules. Density of the nodules was not validated to determine the influence on therapeutic decisions. Conclusion: There is a discrepancy between the manual and automated size measurement of lung metastases which could be significant

  14. Longitudinal Decline in Lung Function Measurements among Saskatchewan Grain Workers

    Directory of Open Access Journals (Sweden)

    Punam Pahwa

    2003-01-01

    Full Text Available OBJECTIVE: To evaluate the relationship between the long term effects of grain dust and decline in lung function among grain elevator workers in Saskatchewan, studied over a 15-year period.

  15. Measurements of H-atom density by a catalytic probe

    International Nuclear Information System (INIS)

    Vesel, A.; Drenik, A.; Mozetic, M.

    2006-01-01

    One of the important plasma parameters in tokamaks is the density of neutral hydrogen atoms which can be measured by catalytic probes. The method is based on the catalytic recombination of H atoms on the metal surface. In order to prevent a substantial drain of atoms by the probe, it should be made as small as possible. But still this effect can not be neglected. Therefore a study of the influence of a catalytic probe on the H-atom density was performed. The source of neutral H-atoms was inductively coupled RF hydrogen plasma. The gas from the discharge vessel was leaked to an experimental chamber through a narrow tube with the diameter of 5 mm and the length of 6 cm. Charged particles created in the discharge vessel were recombined on the walls of the narrow tube, so that the gas entering the experimental chamber was a mixture of hydrogen atoms and molecules only. The density of H-atoms in the experimental chamber was measured with two nickel catalytic probes. One probe was at fixed position and the other one was made movable. A change in the probe signal of the fixed probe was measured versus the position of the movable probe. The measurements were performed at the pressures between 10 Pa and 200 Pa and at two different RF powers 200 W and 300 W. It was found that the density of neutral hydrogen atoms was reduced for about 20% due to the presence of the probe. This result was independent from the pressure in the experimental chamber. (author)

  16. An ultracold neutron storage bottle for UCN density measurements

    Energy Technology Data Exchange (ETDEWEB)

    Bison, G.; Burri, F.; Daum, M. [Paul Scherrer Institute (PSI), CH-5232 Villigen PSI (Switzerland); Kirch, K. [Paul Scherrer Institute (PSI), CH-5232 Villigen PSI (Switzerland); Institute for Particle Physics, Eidgenössische Technische Hochschule (ETH), Zürich (Switzerland); Krempel, J. [Institute for Particle Physics, Eidgenössische Technische Hochschule (ETH), Zürich (Switzerland); Lauss, B., E-mail: bernhard.lauss@psi.ch [Paul Scherrer Institute (PSI), CH-5232 Villigen PSI (Switzerland); Meier, M. [Paul Scherrer Institute (PSI), CH-5232 Villigen PSI (Switzerland); Ries, D., E-mail: dieter.ries@psi.ch [Paul Scherrer Institute (PSI), CH-5232 Villigen PSI (Switzerland); Institute for Particle Physics, Eidgenössische Technische Hochschule (ETH), Zürich (Switzerland); Schmidt-Wellenburg, P.; Zsigmond, G. [Paul Scherrer Institute (PSI), CH-5232 Villigen PSI (Switzerland)

    2016-09-11

    We have developed a storage bottle for ultracold neutrons (UCNs) in order to measure the UCN density at the beamports of the Paul Scherrer Institute's (PSI) UCN source. This paper describes the design, construction and commissioning of the robust and mobile storage bottle with a volume comparable to typical storage experiments (32 L) e.g. searching for an electric dipole moment of the neutron.

  17. Ventilatory protective strategies during thoracic surgery: effects of alveolar recruitment maneuver and low-tidal volume ventilation on lung density distribution.

    Science.gov (United States)

    Kozian, Alf; Schilling, Thomas; Schütze, Hartmut; Senturk, Mert; Hachenberg, Thomas; Hedenstierna, Göran

    2011-05-01

    The increased tidal volume (V(T)) applied to the ventilated lung during one-lung ventilation (OLV) enhances cyclic alveolar recruitment and mechanical stress. It is unknown whether alveolar recruitment maneuvers (ARMs) and reduced V(T) may influence tidal recruitment and lung density. Therefore, the effects of ARM and OLV with different V(T) on pulmonary gas/tissue distribution are examined. Eight anesthetized piglets were mechanically ventilated (V(T) = 10 ml/kg). A defined ARM was applied to the whole lung (40 cm H(2)O for 10 s). Spiral computed tomographic lung scans were acquired before and after ARM. Thereafter, the lungs were separated with an endobronchial blocker. The pigs were randomized to receive OLV in the dependent lung with a V(T) of either 5 or 10 ml/kg. Computed tomography was repeated during and after OLV. The voxels were categorized by density intervals (i.e., atelectasis, poorly aerated, normally aerated, or overaerated). Tidal recruitment was defined as the addition of gas to collapsed lung regions. The dependent lung contained atelectatic (56 ± 10 ml), poorly aerated (183 ± 10 ml), and normally aerated (187 ± 29 ml) regions before ARM. After ARM, lung volume and aeration increased (426 ± 35 vs. 526 ± 69 ml). Respiratory compliance enhanced, and tidal recruitment decreased (95% vs. 79% of the whole end-expiratory lung volume). OLV with 10 ml/kg further increased aeration (atelectasis, 15 ± 2 ml; poorly aerated, 94 ± 24 ml; normally aerated, 580 ± 98 ml) and tidal recruitment (81% of the dependent lung). OLV with 5 ml/kg did not affect tidal recruitment or lung density distribution. (Data are given as mean ± SD.) The ARM improves aeration and respiratory mechanics. In contrast to OLV with high V(T), OLV with reduced V(T) does not reinforce tidal recruitment, indicating decreased mechanical stress.

  18. A measurement of perpendicular current density in an aurora

    International Nuclear Information System (INIS)

    Bering, E.A.; Mozer, F.S.

    1975-01-01

    A Nike Tomahawk sounding rocket was launched into a 400-γ auroral substorm on February 7, 1972, from Esrange, Kiruna, Sweden. The rocket instrumentation included a split Langmuir probe plasma velocity detector and a double-probe electric field detector. Above 140-km altitude the electric field deduced from the ion flow velocity measurement and the electric field measured by the double probe agree to an accuracy within the uncertainties of the two measurements. The difference between the two measurements at altitudes below 140 km provides an in situ measurement of current density and conductivity. Alternatively, if values for the conductivity are assumed, the neutral wind velocity can be deduced. The height-integrated current was 0.11 A/m flowing at an azimuth of 276degree. The neutral winds were strong, exhibited substantial altitude variation in the east-west component, and were predominantly southward

  19. Electron density fluctuation measurements in the TORTUR tokamak

    International Nuclear Information System (INIS)

    Remkes, G.J.J.

    1990-01-01

    This thesis deals with measurements of electron-density fluctuations in the TORTUR tokamak. These measurements are carried out by making use of collective scattering of electromagnetic beams. The choice of the wavelength of the probing beam used in collective scattering experiments has important consequences. in this thesis it is argued that the best choice for a wavelength lies in the region 0.1 - 1 mm. Because sources in this region were not disposable a 2 mm collective scattering apparatus has been used as a fair compromise. The scattering theory, somewhat adapted to the specific TORTUR situation, is discussed in Ch. 2. Large scattering angles are admitted in scattering experiments with 2 mm probing beams. This had consequences for the spatial response functions. Special attention has been paid to the wave number resolution. Expressions for the minimum source power have been determined for two detection techniques. The design and implementation of the scattering apparatus has been described in Ch. 3. The available location of the scattering volume and values of the scattering angle have been determined. The effect of beam deflection due to refraction effects is evaluated. The electronic system is introduced. Ch. 4 presents the results of measurements of density fluctuations in the TORTUR tokamak in the frequency range 1 kHz to 100 MHz end the wave number region 400 - 4000 m -1 in different regions of the plasma. Correlation between density and magnetic fluctuations has been found in a number of cases. During the current decay at the termination of several plasma discharges minor disruptions occurred. The fluctuations during these disruptions have been monitored. Measurements have been performed in hydrogen as well as deuterium. A possible dependence of the wave number on the ion gyroradius has been investigated. The isotropy of the fluctuations in the poloidal plane was investigated. A theoretical discussion of the measured results is given in ch. 5. ( H.W.). 63

  20. A Simple Device for Measuring Static Compliance of Lung-Thorax Combine

    Science.gov (United States)

    Sircar, Sabyasachi

    2015-01-01

    Explaining the concept of lung compliance remains a challenge to the physiology teacher because it cannot be demonstrated easily in human subjects and all attempts until now have used only simulation models. A simple device is described in the present article to measure the compliance of the "lung-thorax" combine in human subjects with…

  1. Measurement of lung fluid volumes and albumin exclusion in sheep

    International Nuclear Information System (INIS)

    Pou, N.A.; Roselli, R.J.; Parker, R.E.; Clanton, J.A.; Harris, T.R.

    1989-01-01

    A radioactive tracer technique was used to determine interstitial diethylenetriaminepentaacetic acid (DTPA) and albumin distribution volume in sheep lungs. 125 I- and/or 131 I-labeled albumin were injected intravenously and allowed to equilibrate for 24 h. 99m Tc-labeled DTPA and 51 Cr-labeled erythrocytes were injected and allowed to equilibrate (2 h and 15 min, respectively) before a lethal dose of thiamylal sodium. Two biopsies (1-3 g) were taken from each lung and the remaining tissue was homogenized for wet-to-dry lung weight and volume calculations. Estimates of distribution volumes from whole lung homogenized samples were statistically smaller than biopsy samples for extravascular water, interstitial 99m Tc-DTPA, and interstitial albumin. The mean fraction of the interstitium (Fe), which excludes albumin, was 0.68 +/- 0.04 for whole lung samples compared with 0.62 +/- 0.03 for biopsy samples. Hematocrit may explain the consistent difference. To make the Fe for biopsy samples match that for homogenized samples, a mean hematocrit, which was 82% of large vessel hematocrit, was required. Excluded volume fraction for exogenous sheep albumin was compared with that of exogenous human albumin in two sheep, and no difference was found at 24 h

  2. Interferometric measurements of plasma density in high-β plasmas

    International Nuclear Information System (INIS)

    Quinn, W.E.

    1977-01-01

    The coupled-cavity laser interferometer technique is particularly applicable to the measurement of pulsed plasma densities. This technique is based on the fact that if a small fraction of a gas laser's output radiation is reflected into the laser with an external mirror, the intensity of the laser output is modulated. These amplitude or intensity modulations are produced by changes in the laser gain. A rotating corner mirror or an oscillating mirror can be used to produce a continuous feedback modulation of the interferometer which produces a continuous background fringe pattern. The presence of plasma in the outer cavity causes an additional change which results in a phase shift of the regular period of the background fringe pattern. The integral of the plasma density along the line of sight can be evaluated by comparison of the time history of the fringes obtained with and without plasma

  3. Measurements of edge density profile modifications during IBW on TFTR

    International Nuclear Information System (INIS)

    Hanson, G.R.; Bush, C.E.; Wilgen, J.B.

    1997-01-01

    Ion Bernstein wave (IBW) antennas are known to have substantial localized effects on the plasma edge. To allow better understanding and measurement of these effects, the TFTR edge reflectometer has been relocated to the new IBW antenna. This move was facilitated by the incorporation of a diagnostic access tube in the IBW antenna identical to the original diagnostic tube in the fast-wave (FW) antenna. This allowed the reflectometer launcher to simply be moved from the old FW antenna to the new IBW antenna. Only a moderate extension of the waveguide transmission line was required to reconnect the reflectometer to the launcher in its new location. Edge density profile modification during IBW experiments has been observed. Results from IBW experiments will be presented and contrasted to the edge density modifications previously observed during FW heating experiments

  4. Measurements of Deposition, Lung Surface Area and Lung Fluid for Simulation of Inhaled Compounds.

    Science.gov (United States)

    Fröhlich, Eleonore; Mercuri, Annalisa; Wu, Shengqian; Salar-Behzadi, Sharareh

    2016-01-01

    Modern strategies in drug development employ in silico techniques in the design of compounds as well as estimations of pharmacokinetics, pharmacodynamics and toxicity parameters. The quality of the results depends on software algorithm, data library and input data. Compared to simulations of absorption, distribution, metabolism, excretion, and toxicity of oral drug compounds, relatively few studies report predictions of pharmacokinetics and pharmacodynamics of inhaled substances. For calculation of the drug concentration at the absorption site, the pulmonary epithelium, physiological parameters such as lung surface and distribution volume (lung lining fluid) have to be known. These parameters can only be determined by invasive techniques and by postmortem studies. Very different values have been reported in the literature. This review addresses the state of software programs for simulation of orally inhaled substances and focuses on problems in the determination of particle deposition, lung surface and of lung lining fluid. The different surface areas for deposition and for drug absorption are difficult to include directly into the simulations. As drug levels are influenced by multiple parameters the role of single parameters in the simulations cannot be identified easily.

  5. Physical properties of Martian meteorites: Porosity and density measurements

    Science.gov (United States)

    Coulson, Ian M.; Beech, Martin; Nie, Wenshuang

    Martian meteorites are fragments of the Martian crust. These samples represent igneous rocks, much like basalt. As such, many laboratory techniques designed for the study of Earth materials have been applied to these meteorites. Despite numerous studies of Martian meteorites, little data exists on their basic structural characteristics, such as porosity or density, information that is important in interpreting their origin, shock modification, and cosmic ray exposure history. Analysis of these meteorites provides both insight into the various lithologies present as well as the impact history of the planet's surface. We present new data relating to the physical characteristics of twelve Martian meteorites. Porosity was determined via a combination of scanning electron microscope (SEM) imagery/image analysis and helium pycnometry, coupled with a modified Archimedean method for bulk density measurements. Our results show a range in porosity and density values and that porosity tends to increase toward the edge of the sample. Preliminary interpretation of the data demonstrates good agreement between porosity measured at 100× and 300× magnification for the shergottite group, while others exhibit more variability. In comparison with the limited existing data for Martian meteorites we find fairly good agreement, although our porosity values typically lie at the low end of published values. Surprisingly, despite the increased data set, there is little by way of correlation between either porosity or density with parameters such as shock effect or terrestrial residency. Further data collection on additional meteorite samples is required before more definitive statements can be made concerning the validity of these observations.

  6. The Physical Density of the City—Deconstruction of the Delusive Density Measure with Evidence from Two European Megacities

    Directory of Open Access Journals (Sweden)

    Hannes Taubenböck

    2016-11-01

    Full Text Available Density is among the most important descriptive as well as normative measures in urban research. While its basic concept is generally understandable, approaches towards the density measure are manifold, diverse and of multidimensional complexity. This evolves from differing thematic, spatial and calculative specifications. Consequently, applied density measures are often used in a subjective, non-transparent, unspecific and thus non-comparable manner. In this paper, we aim at a systematic deconstruction of the measure density. Varying thematic, spatial and calculative dimensions show significant influence on the measure. With both quantitative and qualitative techniques of evaluation, we assess the particular influences on the measure density. To do so, we reduce our experiment setting to a mere physical perspective; that is, the quantitative measures building density, degree of soil sealing, floor space density and, more specifically, the density of generic structural classes such as open spaces and highest built-up density areas. Using up-to-date geodata derived from remote sensing and volunteered geographic information, we build upon high-quality spatial information products such as 3-D city models. Exemplified for the comparison of two European megacities, namely Paris and London, we reveal and systemize necessary variables to be clearly defined for meaningful conclusions using the density measure.

  7. Sensors for Metering Heat Flux Area Density and Metrological Equipment for the Heat Flux Density Measurement

    Science.gov (United States)

    Doronin, D. O.

    2018-04-01

    The demand in measuring and studies of heat conduction of various media is very urgent now. This article considers the problem of heat conduction monitoring and measurement in various media and materials in any industries and branches of science as well as metrological support of the heat flux measurement equipment. The main study objects are both the sensors manufactured and facilities onto which these sensors will be installed: different cladding structures of the buildings, awnings, rocket fairings, boiler units, internal combustion engines. The Company develops and manufactures different types of heat flux sensors: thermocouple, thin-film, heterogeneous gradient as well as metrological equipment for the gauging calibration of the heat flux density measurement. The calibration shall be performed using both referencing method in the unit and by fixed setting of the heat flux in the unit. To manufacture heterogeneous heat flux gradient sensors (HHFGS) the Company developed and designed a number of units: diffusion welding unit, HHFGS cutting unit. Rather good quality HHFGS prototypes were obtained. At this stage the factory tests on the equipment for the heat flux density measurement equipment are planned. A high-sensitivity heat flux sensor was produced, now it is tested at the Construction Physics Research Institute (Moscow). It became possible to create thin-film heat flux sensors with the sensitivity not worse than that of the sensors manufactured by Captec Company (France). The Company has sufficient premises to supply the market with a wide range of sensors, to master new sensor manufacture technologies which will enable their application range.

  8. Density and SUV Ratios from PET/CT in the Detection of Mediastinal Lymph Node Metastasis in Non-small Cell Lung Cancer

    Directory of Open Access Journals (Sweden)

    Tingting SHAO

    2015-03-01

    Full Text Available Background and objective Mediastinal involvement in lung cancer is a highly significant prognostic factor for survival, and accurate staging of the mediastinum will correctly identify patients who will benefit the most from surgery. Positron emission tomography/computed tomography (PET/CT has become the standard imaging modality for the staging of patients with lung cancer. The aim of this study is to investigate 18-fluoro-2-deoxy-glucose (18F-FDG PET/CT imaging in the detection of mediastinal disease in lung cancer. Methods A total of 72 patients newly diagnosed with non-small cell lung cancer (NSCLC who underwent preoperative whole-body 18F-FDG PET/CT were retrospectively included. All patients underwent radical surgery and mediastinal lymph node dissection. Mediastinal disease was histologically confirmed in 45 of 413 lymph nodes. PET/CT doctors analyzed patients’ visual images and evaluated lymph node’s short axis, lymph node’s maximum standardized uptake value (SUVmax, node/aorta density ratio, node/aorta SUV ratio, and other parameters using the histopathological results as the reference standard. The optimal cutoff value for each ratio was determined by receiver operator characteristic curve analysis. Results Using a threshold of 0.9 for density ratio and 1.2 for SUV ratio yielded high accuracy for the detection of mediastinal disease. The lymph node’s short axis, lymph node’s SUVmax, density ratio, and SUV ratio of integrated PET/CT for the accuracy of diagnosing mediastinal lymph node was 95.2%. The diagnostic accuracy of mediastinal lymph node with conventional PET/CT was 89.8%, whereas that of PET/CT comprehensive analysis was 90.8%. Conclusion Node/aorta density ratio and SUV ratio may be complimentary to conventional visual interpretation and SUVmax measurement. The use of lymph node’s short axis, lymph node’s SUVmax, and both ratios in combination is better than either conventional PET/CT analysis or PET

  9. Remote application of an oscillatory system for density measurements

    International Nuclear Information System (INIS)

    Fortsch, E.M.; Wade, M.A.

    1974-01-01

    An Anton-Paar densimeter was modified for remote use and installed in the Remote Analytical Facility of the Idaho Chemical Processing Plant. This instrument determines density by measuring the deviation in resonant frequency of a hollow-glass mechanical oscillator when filled with sample material. The volume of the oscillator is constant and any change in its frequency is due to the sample. The change in frequency is a measure of the mass of the sample. Since there is no need to measure either volume or mass, the remote manipulations are simplified. This unit replaced existing falling-drop equipment with a reduction in cost and improvement of precision. The remote unit is used routinely 24 h a day with a precision of better than +- 5 x 10 -4 g/ml

  10. Improved electrode positions for local impedance measurements in the lung-a simulation study.

    Science.gov (United States)

    Orschulik, Jakob; Petkau, Rudolf; Wartzek, Tobias; Hochhausen, Nadine; Czaplik, Michael; Leonhardt, Steffen; Teichmann, Daniel

    2016-12-01

    Impedance spectroscopy can be used to analyze the dielectric properties of various materials. In the biomedical domain, it is used as bioimpedance spectroscopy (BIS) to analyze the composition of body tissue. Being a non-invasive, real-time capable technique, it is a promising modality, especially in the field of lung monitoring. Unfortunately, up to now, BIS does not provide any regional lung information as the electrodes are usually placed in hand-to-hand or transthoracic configurations. Even though transthoracic electrode configurations are in general capable of monitoring the lung, no focusing to specific regions is achieved. In order to resolve this issue, we use a finite element model (FEM) of the human body to study the effect of different electrode configurations on measured BIS data. We present evaluation results and show suitable electrode configurations for eight lung regions. We show that, using these optimized configurations, BIS measurements can be focused to desired regions allowing local lung analysis.

  11. Evaluation of the Automatic Density Compensation for Pressurizer Level Measurement

    International Nuclear Information System (INIS)

    Jeong, Insoo; Min, Seohong; Ahn, Myunghoon

    2014-01-01

    When using two transmitters, it is difficult for the operators to identify the correct level of the pressurizer (PZR) upon failure of one of the two transmitters. For this reason, Korean Utility Requirements Document (KURD) requires that the operators to use three independent level indicators. Two hot calibrated transmitters and one cold calibrated transmitter compose PZR level transmitters in APR1400. In this paper, the deviation between cold calibration and hot calibration is evaluated, and the application of compensated PZR level measurement and uncompen-sated PZR level measurement during the normal operation of APR1400 are introduced. The PZR level signals for APR1400 come in three channels. To satisfy the KURD requirements for PZR level measurement, and at the same time to accomplish correction design and implementation, applicability and differences between hot calibration and cold calibration, compensated level and uncompensated level were evaluated as follows: For proper indication of PZR levels under normal operating condition, two of the three transmitters went through hot calibration and the remaining one transmitter went through cold calibration. This was to allow indicating entire regions of PZR regardless of the plant operation modes. For automatic density compensation per KURD requirements, the algorithm of the density compensated PZR level implemented in the DCS controller and PRV logic is adopted as a signal validation method

  12. SU-F-J-162: Is Bulky Electron Density Assignment Appropriatefor MRI-Only Based Treatment Planning for Lung Cancer?

    Energy Technology Data Exchange (ETDEWEB)

    Prior, P; Chen, X; Johnstone, C; Gore, E; Li, X [Medical College of Wisconsin, Milwaukee, WI (United States)

    2016-06-15

    Purpose: To assess the appropriateness of bulky electron density assisment for MRI-only treatment planning for lung cancer via comparing dosimetric difference between MRI- and CT-based plans. Methods: Planning 4DCTs acquired for six representative lung cancer patients were used to generate CT-based IMRT plans. To avoid the effect of anatomic difference between CT and MRI, MRI-based plans were generated using CTs by forcing the relative electron density (rED) of organ specific values from ICRU report 46 and using the mean rED value of the internal target volume (ITV) of the patient for the ITV. Both CT and “MRI” plans were generated using a research planning system (Monaco, Elekta) employing Monte Carlo dose calculation the following dose-volume-parameters (DVPs): D99 – dose delivered to 99% of the ITV/PTV volume; D95; D5; D1; Vpd –volume receiving the prescription dose; V5 – volume of normal lung irradiated > 5 Gy; and V20. The percent point difference and dose difference was used for comparison for Vpd-V5-V20 and D99-D1, respectively. Four additional plans per patient were calculated with rEDITV = 0.6 and 1.0 and rEDlung = 0.1 and 0.5. Results: Noticeable differences in the ITV and PTV point doses and DVPs were observed. Variations in Vpd ranged from 0.0–6.4% and 0.32–18.3% for the ITV and PTV, respectively. The ITV and PTV variations in D99, D95, D5 and D1 were 0.15–3.2 Gy. The normal lung V5 & V20 variations were no larger than 1.9%. In some instances, varying the rEDITV between rEDmean, 0.6 and 1.0 resulted in D95 increases ranging from 3.9–6.3%. Uniform rED assignment on normal lung affected DVPs of ITV and PTV by 4.0–9.8% and 0.3–19.6%, respectively. Conclusion: The commonly-used uniform rED assignment in MRI-only based planning may not be appropriate for lung-cancer. A voxel based method, e.g. synthetic CT generated from MRI data, is required. This work was partially funded by Elekta, Inc.

  13. X-ray spectroscopy for high energy-density X pinch density and temperature measurements (invited)

    International Nuclear Information System (INIS)

    Pikuz, S.A.; Shelkovenko, T.A.; Chandler, K.M.; Mitchell, M.D.; Hammer, D.A.; Skobelev, I.Y.; Shlyaptseva, A.S.; Hansen, S.B.

    2004-01-01

    X pinch plasmas produced from fine metal wires can reach near solid densities and temperatures of 1 keV or even more. Plasma conditions change on time scales as short as 5-10 ps as determined using an x-ray streak camera viewing a focusing crystal spectrograph or directly viewing the plasma through multiple filters on a single test. As a result, it is possible to determine plasma conditions from spectra with ∼10 ps time resolution. Experiments and theory are now coming together to give a consistent picture of the dynamics and kinetics of these high energy density plasmas with very high temporal and spatial precision. A set of diagnostic techniques used in experiments for spectrally, temporally, and spatially resolved measurements of X pinch plasmas is described. Results of plasma parameter determination from these measurements are presented. X ray backlighting of one x-pinch by another with ∼30 ps x-ray pulses enables the dynamics and kinetics to be correlated in time

  14. Quantitative measurement of the orbital angular momentum density of light

    CSIR Research Space (South Africa)

    Dudley, Angela L

    2012-03-01

    Full Text Available of the azimuthal mode index, n, on LCD1 is equiva- lent to n on LCD2. If the reader wishes to orientate the experimental setup differently, such that the two SLMs have the same orientation (i.e., are not mirror images of each other), the complex conjugate... measurement, is separated into two parts: (1) the generation of the optical field and (2) the mea- surement of the OAM density, which is achieved by performing a modal decomposition of the opti- cal field. A. Symmetric Superposition of Two Bessel Beams...

  15. Poloidal polarimeter for current density measurements in ITER

    International Nuclear Information System (INIS)

    Donne, A.J.H.; Graswinckel, M.F.; Cavinato, M.; Giudicotti, L.; Zilli, E.; Gil, C.; Koslowski, H.R.; McCarthy, P.; Nyhan, C.; Prunty, S.; Spillane, M.; Walker, C.

    2004-01-01

    One of the systems envisaged for measuring the current density profile in the ITER is a 118 μm poloidal polarimeter system. The proposed system has two independent views: one fan of chords observes the plasma via an equatorial port and a second fan views down from an upper port. This article will present the status of the on-going work and will address issues as sensitivity and accuracy, refraction, Gaussian beam ray-tracing, alignment, and calibration as well as some specific design details

  16. A torque-measuring micromotor provides operator independent measurements marking four different density areas in maxillae.

    Science.gov (United States)

    Di Stefano, Danilo Alessio; Arosio, Paolo; Piattelli, Adriano; Perrotti, Vittoria; Iezzi, Giovanna

    2015-02-01

    Bone density at implant placement site is a key factor to obtain the primary stability of the fixture, which, in turn, is a prognostic factor for osseointegration and long-term success of an implant supported rehabilitation. Recently, an implant motor with a bone density measurement probe has been introduced. The aim of the present study was to test the objectiveness of the bone densities registered by the implant motor regardless of the operator performing them. A total of 3704 bone density measurements, performed by means of the implant motor, were registered by 39 operators at different implant sites during routine activity. Bone density measurements were grouped according to their distribution across the jaws. Specifically, four different areas were distinguished: a pre-antral (between teeth from first right maxillary premolar to first left maxillary premolar) and a sub-antral (more distally) zone in the maxilla, and an interforaminal (between and including teeth from first left mandibular premolar to first right mandibular premolar) and a retroforaminal (more distally) zone in the lower one. A statistical comparison was performed to check the inter-operators variability of the collected data. The device produced consistent and operator-independent bone density values at each tooth position, showing a reliable bone-density measurement. The implant motor demonstrated to be a helpful tool to properly plan implant placement and loading irrespective of the operator using it.

  17. Density Measurement of Compact Toroid with Mach-Zehnder Interferometer

    Science.gov (United States)

    Laufman-Wollitzer, Lauren; Endrizzi, Doug; Brookhart, Matt; Flanagan, Ken; Forest, Cary

    2016-10-01

    Utilizing a magnetized coaxial plasma gun (MCPG) built by Tri Alpha Energy, a dense compact toroid (CT) is created and injected at high speed into the Wisconsin Plasma Astrophysics Laboratory (WiPAL) vessel. A modified Mach-Zehnder interferometer from the Line-Tied Reconnection Experiment (LTRX) provides an absolute measurement of electron density. The interferometer is located such that the beam intersects the plasma across the diameter of the MCPG drift region before the CT enters the vessel. This placement ensures that the measurement is taken before the CT expand. Results presented will be used to further analyze characteristics of the CT. Funding provided by DoE, NSF, and WISE Summer Research.

  18. Positron emission tomography of the lung

    International Nuclear Information System (INIS)

    Wollmer, P.

    1984-01-01

    Positron emission tomography enables the distribution of positron emitting isotopes to be imaged in a transverse plane through the body and the regional concentration of the isotope to be measured quantitatively. This thesis reports some applications of positron emission tomography to studies of pulmonary pathophysiology. Measurements in lung phantoms showed that regional lung density could be measured from a transmission tomogram obtained with an external source of positron emitting isotope. The regional, fractional blood volume was measured after labelling the blood with carbon-11-monoxide. Regional extravascular lung density (lung tissue and interstitial water per unit thoracic volume) was obtained by subtracting fractional blood volume from lung density. Measurements in normal subjects revealed large regional variations in lung density and fractional blood volume in the supine posture. Extravascular lung density showed a more uniform distribution. The technique has been used to study patients with chronic interstitial pulmonary oedema, pulmonary sarcoidosis and fibrosis, pulmonary arterial hypertension and patients with intracardiac, left-to-right shunt. Tomographic measurements of pulmonary tissue concentration of radionuclides are difficult, since corrections for the blood content and the inflation of the lung must be applied. A simultaneous measurement of lung density and fractional blood volume allows such corrections to be made and the extravascular tracer concentration to be calculated. This has been applied to measurements of the tissue penetration of carbon-11-labelled erythromycin in patients with lobar pneumonia. (author)

  19. Technical Note: Is bulk electron density assignment appropriate for MRI-only based treatment planning for lung cancer?

    Science.gov (United States)

    Prior, Phil; Chen, Xinfeng; Gore, Elizabeth; Johnstone, Candice; Li, X Allen

    2017-07-01

    MRI-based treatment planning in radiation therapy (RT) is prohibitive, in part, due to the lack of electron density (ED) information within the image. The dosimetric differences between MRI- and CT-based planning for intensity modulated RT (IMRT) of lung cancer were investigated to assess the appropriateness of bulk ED assignment. Planning CTs acquired for six representative lung cancer patients were used to generate bulk ED IMRT plans. To avoid the effect of anatomic differences between CT and MRI, "simulated MRI-based plans" were generated by forcing the relative ED (rED) to water on CT-delineated structures using organ specific values from the ICRU Report 46 and using the mean rED value of the internal target volume (ITV) from the planning CT. The "simulated MRI-based plans" were generated using a research planning system (Monaco v5.09.07a, Elekta, AB) and employing Monte Carlo dose calculation. The following dose-volume-parameters (DVPs) were collected from both the "simulated MRI-based plans" and the original planning CT: D 95 , the dose delivered to 95% of the ITV & planning target volume (PTV), D 5 and V 5 , the volume of normal lung irradiated ≥5 Gy. The percent point difference and relative dose difference were used for comparison with the CT based plan for V 5 and D 95 respectively. A total of five plans per patient were generated; three with the ITV rED (rED ITV ) = 1.06, 1.0 and the mean value from the planning CT while the lung rED (rED lung ) was fixed at the ICRU value of 0.26 and two with rED lung = 0.1 and 0.5 while the rED ITV was fixed to the mean value from the planning CT. Noticeable differences in the ITV and PTV DVPs were observed. Variations of the normal lung V 5 can be as large as 9.6%. In some instances, varying the rED ITV between rED mean and 1.06 resulted in D 95 increases ranging from 3.9% to 6.3%. Bulk rED assignment on normal lung affected the DVPs of the ITV and PTV by 4.0-9.8% and 0.3-19.6% respectively. Dose volume histograms

  20. Use of sup(81m)Kr gas for the measurement of absolute regional lung ventilation

    Energy Technology Data Exchange (ETDEWEB)

    Nosil, J; Bajzer, Z; Spaventi, S [Mladen Stojanovic Clinical Hospital, Zagreb (Yugoslavia). Dept. of Nuclear Medicine and Oncology; Institut Rudjer Boskovic, Zagreb (Yugoslavia))

    1977-02-01

    In this paper a new method of using sup(81m)Kr for the measurement of specific absolute regional lung ventilation is described. Experimental data suitable for the calculation of quantitative regional ventilation are provided using an adequate respiratory system for sup(81m)Kr dosage and a scintillation gamma camera interfaced to a digital computer. A simple mathematical lung model for the inhalation of sup(81m)Kr is used to determine the specific ventilation and the parameters proportional to the ventilation for the whole lung and different lung regions in patients and in healthy subjects. The lung count rate for a given region correlated well with the ventilation of that region. Clinical examples are given and discussed.

  1. Annual measurements of gain and loss in aboveground carbon density

    Science.gov (United States)

    Baccini, A.; Walker, W. S.; Carvalho, L.; Farina, M.; Sulla-menashe, D. J.; Houghton, R. A.

    2017-12-01

    Tropical forests hold large stores of carbon, but their net carbon balance is uncertain. Land use and land-cover change (LULCC) are believed to release between 0.81 and 1.14 PgC yr-1, while intact native forests are thought to be a net carbon sink of approximately the same magnitude. Reducing the uncertainty of these estimates is not only fundamental to the advancement of carbon cycle science but is also of increasing relevance to national and international policies designed to reduce emissions from deforestation and forest degradation (e.g., REDD+). Contemporary approaches to estimating the net carbon balance of tropical forests rely on changes in forest area between two periods, typically derived from satellite data, together with information on average biomass density. These approaches tend to capture losses in biomass due to deforestation (i.e., wholesale stand removals) but are limited in their sensitivity to forest degradation (e.g., selective logging or single-tree removals), which can account for additional biomass losses on the order of 47-75% of deforestation. Furthermore, while satellite-based estimates of forest area loss have been used successfully to estimate associated carbon losses, few such analyses have endeavored to determine the rate of carbon sequestration in growing forests. Here we use 12 years (2003-2014) of pantropical satellite data to quantify net annual changes in the aboveground carbon density of woody vegetation (MgC ha-1yr-1), providing direct, measurement-based evidence that the world's tropical forests are a net carbon source of 425.2 ± 92.0 Tg C yr-1. This net release of carbon consists of losses of 861.7 ± 80.2 Tg C yr-1 and gains of -436.5 ± 31.0 Tg C yr-1 . Gains result from forest growth; losses result from reductions in forest area due to deforestation and from reductions in biomass density within standing forests (degradation), with the latter accounting for 68.9% of overall losses. Our findings advance previous research

  2. CT Measured Psoas Density Predicts Outcomes After Enterocutaneous Fistula Repair

    Science.gov (United States)

    Lo, Wilson D.; Evans, David C.; Yoo, Taehwan

    2018-01-01

    Background Low muscle mass and quality are associated with poor surgical outcomes. We evaluated CT measured psoas muscle density as a marker of muscle quality and physiologic reserve, and hypothesized that it would predict outcomes after enterocutaneous fistula repair (ECF). Methods We conducted a retrospective cohort study of patients 18 – 90 years old with ECF failing non-operative management requiring elective operative repair at Ohio State University from 2005 – 2016 that received a pre-operative abdomen/pelvis CT with intravenous contrast within 3 months of their operation. Psoas Hounsfield Unit average calculation (HUAC) were measured at the L3 level. 1 year leak rate, 90 day, 1 year, and 3 year mortality, complication risk, length of stay, dependent discharge, and 30 day readmission were compared to HUAC. Results 100 patients met inclusion criteria. Patients were stratified into interquartile (IQR) ranges based on HUAC. The lowest HUAC IQR was our low muscle quality (LMQ) cutoff, and was associated with 1 year leak (OR 3.50, p < 0.01), 1 year (OR 2.95, p < 0.04) and 3 year mortality (OR 3.76, p < 0.01), complication risk (OR 14.61, p < 0.01), and dependent discharge (OR 4.07, p < 0.01) compared to non-LMQ patients. Conclusions Psoas muscle density is a significant predictor of poor outcomes in ECF repair. This readily available measure of physiologic reserve can identify patients with ECF on pre-operative evaluation that have significantly increased risk that may benefit from additional interventions and recovery time to mitigate risk before operative repair. PMID:29505144

  3. Optical measurement of isolated canine lung filtration coefficients at normal hematocrits.

    Science.gov (United States)

    Klaesner, J W; Pou, N A; Parker, R E; Finney, C; Roselli, R J

    1997-12-01

    In this study, lung filtration coefficient (Kfc) values were measured in eight isolated canine lung preparations at normal hematocrit values using three methods: gravimetric, blood-corrected gravimetric, and optical. The lungs were kept in zone 3 conditions and subjected to an average venous pressure increase of 10.24 +/- 0.27 (SE) cmH2O. The resulting Kfc (ml . min-1 . cmH2O-1 . 100 g dry lung wt-1) measured with the gravimetric technique was 0.420 +/- 0.017, which was statistically different from the Kfc measured by the blood-corrected gravimetric method (0.273 +/- 0.018) or the product of the reflection coefficient (sigmaf) and Kfc measured optically (0. 272 +/- 0.018). The optical method involved the use of a Cellco filter cartridge to separate red blood cells from plasma, which allowed measurement of the concentration of the tracer in plasma at normal hematocrits (34 +/- 1.5). The permeability-surface area product was measured using radioactive multiple indicator-dilution methods before, during, and after venous pressure elevations. Results showed that the surface area of the lung did not change significantly during the measurement of Kfc. These studies suggest that sigmafKfc can be measured optically at normal hematocrits, that this measurement is not influenced by blood volume changes that occur during the measurement, and that the optical sigmafKfc agrees with the Kfc obtained via the blood-corrected gravimetric method.

  4. The impact of mammographic imaging systems on density measurement

    Science.gov (United States)

    Damases, Christine N.; Brennan, Patrick C.; McEntee, Mark F.

    2015-03-01

    The purpose of this study is to investigate whether having a mammogram on differing manufacturer equipment will affect a woman's breast density (BD) measurement. The data set comprised of 40 cases, each containing a combined image of the left craniocaudal (LCC) and left mediolateral oblique (LMLO). These images were obtained from 20 women age between 42-89 years. The images were acquired on two imaging systems (GE and Hologic) one year apart. Volumetric BD was assessed by using Volpara Density Grade (VDG) and average BD% (AvBD%). Twenty American Board of Radiology (ABR) examiners assessed the same images using the BIRADS BD scale 1-4. Statistical comparisons were performed on the means using Mann-Whitney, on correlation using Spearman's rank coefficient of correlation and agreement using Cohen's Kappa. The absolute median BIRADS difference between GE and Hologic was 0.225 (2.00 versus 2.00; pperfect agreement for VDG (κ=0.933; p<0.001).

  5. Measurement of total lung capacity : a comparison of spiral CT and spirometry

    International Nuclear Information System (INIS)

    Chung, Kyung Il; Park, Kyung Ju; Lee, Eh Hyung; Yune, Heun Young; Suh, Jung Ho; Choe, Kyu Ok; Lim, Tae Hwan; Chung, In Hyuk

    1996-01-01

    To determine the potential of spiral CT as a functional imaging modality of the lung aside from its proven value in morphological depiction. Spiral CT scan was performed in ten normal female and nine normal male adults (mean age: 39, height: 163 cm, weight: 62 kg ) after single full breath-holding. Three dimensional lung images were reconstructed(minimal threshold value: -1,000HU, maximal threshold values: -150, 250, -350, -450 HU) to obtain total lung volume(TLV) on a histogram. Total lung volume measured by spiral CT was compared with TLV obtained by spirometry. Mean TLV measured by spirometry was 5.62L and TLV measured by CT at maximal threshold values of -150, -250, -350, and -450 HU was 5.53, 5.33, 5.15, and 4.98L, respectively. Mean absolute differences between the modalities of 0.17L(3%), 0.32L(5.6%), 0.48L(8.5%), 0.65L(11.5%) were statistically significant(p<0.001). Linear regression coefficients between the modalities were 0.99, 0.97, 095, and 0.94 and no statistically significant differences in accuracy of threshold levels in the estimation of lung volume(r=0.99, standard error=0.034L in all) were seen. TLV measured by spiral CT closely approximated that measured by spirometry. Spiral CT may be useful as a means of evaluating lung function

  6. Bone mineral density measurement over the shoulder region

    DEFF Research Database (Denmark)

    Doetsch, A M; Faber, J; Lynnerup, N

    2002-01-01

    values decreased with age (P shoulder BMD levels increased significantly with increased body mass index (BMI) (P positive relationship between the increased hip/shoulder BMD differential with BMI supports the conclusion that the shoulder is subject......The purpose of this study was to (1). establish a method for measuring bone mineral density (BMD) over the shoulder region; (2). compare the relationship between shoulder BMD levels with hip BMD and body mass index (BMI); and (3). discuss the relevance of the shoulder scan as an early indicator...... of osteoporosis compared with hip scans, the latter representing a weight-bearing part of the skeleton. We developed a scanning procedure, including a shoulder fixation device, and determined the most appropriate software in order to establish a reference material with the highest possible precision. Duplicate...

  7. Comparison of sliced lungs with whole lung sets for a torso phantom measured with Ge detectors using Monte Carlo simulations (MCNP).

    Science.gov (United States)

    Kramer, Gary H; Guerriere, Steven

    2003-02-01

    Lung counters are generally used to measure low energy photons (<100 keV). They are usually calibrated with lung sets that are manufactured from a lung tissue substitute material that contains homogeneously distributed activity; however, it is difficult to verify either the activity in the phantom or the homogeneity of the activity distribution without destructive testing. Lung sets can have activities that are as much as 25% different from the expected value. An alternative method to using whole lungs to calibrate a lung counter is to use a sliced lung with planar inserts. Experimental work has already indicated that this alternative method of calibration can be a satisfactory substitute. This work has extended the experimental study by the use of Monte Carlo simulation to validate that sliced and whole lungs are equivalent. It also has determined the optimum slice thicknesses that separate the planar sources in the sliced lung. Slice thicknesses have been investigated in the range of 0.5 cm to 9.0 cm and at photon energies from 17 keV to 1,000 keV. Results have shown that there is little difference between sliced and whole lungs at low energies providing that the slice thickness is 2.0 cm or less. As the photon energy rises the slice thickness can increase substantially with no degradation on equivalence.

  8. Effect of Clothing on Measurement of Bone Mineral Density.

    Science.gov (United States)

    McNamara, Elizabeth A; Feldman, Anna Z; Malabanan, Alan O; Abate, Ejigayehu G; Whittaker, LaTarsha G; Yano-Litwin, Amanda; Dorazio, Jolene; Rosen, Harold N

    2016-01-01

    It is unknown whether allowing patients to have BMD (bone mineral density) studies acquired while wearing radiolucent clothing adlib contributes appreciably to the measurement error seen. To examine this question, a spine phantom was scanned 30 times without any clothing, while draped with a gown, and while draped with heavy winter clothing. The effect on mean BMD and on SD (standard deviation) was assessed. The effect of clothing on mean or SD of the area was not significant. The effect of clothing on mean and SD for BMD was small but significant and was around 1.6% for the mean. However, the effect on BMD precision was much more clinically important. Without clothing the spine phantom had an least significant change of 0.0077 gm/cm(2), while when introducing variability of clothing the least significant change rose as high as 0.0305 gm/cm(2). We conclude that, adding clothing to the spine phantom had a small but statistically significant effect on the mean BMD and on variance of the measurement. It is unlikely that the effect on mean BMD has any clinical significance, but the effect on the reproducibility (precision) of the result is likely clinically significant. Copyright © 2016 The International Society for Clinical Densitometry. Published by Elsevier Inc. All rights reserved.

  9. Quasi-quadrature interferometer for plasma density radial profile measurements

    International Nuclear Information System (INIS)

    Lowenthal, D.D.; Hoffman, A.L.

    1979-01-01

    A cw Mach Zehnder multichannel interferometer has been developed to measure time-dependent fractional fringe shifts with an accuracy of one-fortieth fringe. The design is quasi-quadrature in that known phase shifts, introduced in the reference beam, are time multiplexed with the normal reference beam. This technique requires only one detector per interferometer channel as compared to two detectors for most quadrature designs. The quadrature information makes the sense of density changes unambiguous, it automatically calibrates the instrument during the plasma event, and it makes fringe shift measurements virtually independent of fringe contrast fluctuations caused by plasma refractive and/or absorptive effects. The interferometer optical design is novel in that the electro-optic crystal used to introduce the 90 0 phase shifts is located in the common 2-mm-diam HeNe entrance beam to the interferometer, by exploiting polarization techniques, rather than in the expanded 1--2-cm reference beam itself. This arrangement greatly reduces the size, cost, and high-voltage requirements for the phase modulating crystal

  10. Clinical Utility of Additional Measurement of Total Lung Capacity in Diagnosing Obstructive Lung Disease in Subjects With Restrictive Pattern of Spirometry.

    Science.gov (United States)

    Lee, Hyun; Chang, Boksoon; Kim, Kyunga; Song, Won Jun; Chon, Hae Ri; Kang, Hyung Koo; Kim, Jung Soo; Jeong, Byeong-Ho; Oh, Yeon-Mok; Koh, Won-Jung; Park, Hye Yun

    2016-04-01

    Total lung capacity (TLC), forced expiratory flow between 25 and 75% (FEF25-75%), peak expiratory flow (PEF), or post-bronchodilator volume response is recommended to detect obstructive abnormalities in the lung. The present study was performed to evaluate the usefulness of these pulmonary function test (PFT) parameters to diagnose obstructive lung disease in subjects with a restrictive pattern of spirometry. A retrospective study was conducted in 64 subjects with a restrictive pattern of spirometry (normal FEV1/FVC and low FVC) out of 3,030 patients who underwent all pre- and post-bronchodilator spirometry and lung volume measurement between April 2008 and December 2010. After subjects were clinically classified into those with obstructive lung disease, restrictive lung disease, and mixed lung disease, the agreements between the clinical diagnosis and PFT classification according to TLC, FEF(25-75%), PEF, and post-bronchodilator response criteria were compared. Of 64 subjects, 18 (28.1%) were classified with obstructive lung disease, 39 (60.9%) had restrictive lung disease, 1 (1.6%) had mixed lung disease, and 6 (9.4%) had no clinical lung disease. Among the 58 subjects with clinical lung disease, 22 (37.9%), 37 (63.8%), 33 (56.9%), and 3 (5.2%) were classified as having obstructive pattern based on TLC, FEF25-75%, PEF, and post-bronchodilator response criteria, respectively. The kappa coefficients for the agreement between the clinical classification and PFT classification using TLC, FEF25-75%, PEF, and post-bronchodilator response criteria in 58 subjects were 0.59, 0.18, 0.17, and spirometry, when obstructive lung disease is clinically suspected. Copyright © 2016 by Daedalus Enterprises.

  11. Lung

    International Nuclear Information System (INIS)

    DeNardo, G.L.; Blankenship, W.J.; Burdine, J.A. Jr.; DeNardo, S.J.

    1975-01-01

    At present no simple statement can be made relative to the role of radionuclidic lung studies in the pediatric population. It is safe to assume that they will be used with increasing frequency for research and clinical applications because of their sensitivity and ready applicability to the pediatric patient. Methods comparable to those used in adults can be used in children older than 4 years. In younger children, however, a single injection of 133 Xe in solution provides an index of both regional perfusion and ventilation which is easier to accomplish. This method is particularly valuable in infants and neonates because it is rapid, requires no patient cooperation, results in a very low radiation dose, and can be repeated in serial studies. Radionuclidic studies of ventilation and perfusion can be performed in almost all children if the pediatrician and the nuclear medicine specialist have motivation and ingenuity. S []ontaneous pulmonary vascular occlusive disease which occurs in infants and pulmonary emboli in children are easily detected using radionuclides. The pathophysiologic defects of pulmonary agenesis, bronchopulmonary sequestration, and foreign body aspiration may be demonstrated by these techniques. These techniques also appear to be useful in following patients with bronchial asthma, cystic fibrosis, congenital emphysema, and postinfection pulmonary abnormalities. (auth)

  12. CO{sub 2} laser diagnostics for measurements of the plasma density profile and plasma density fluctuations on LHD

    Energy Technology Data Exchange (ETDEWEB)

    Vyacheslavov, L.N. [Budker Institute of Nuclear Physics, Novosibirsk (Russian Federation); Tanaka, K.; Kawahata, K. [National Inst. for Fusion Science, Toki, Gifu (Japan)

    2001-04-01

    A CO{sub 2} laser based diagnostics complimentary to the existing FIR interferometer is proposed. It combines interferometry for plasma density profile measurement under conditions of large density gradients, and both imaging and scattering techniques for observation of plasma fluctuations. Two-colour interferometer with a slablike probe beam and a single multichannel linear detector array provide observation of plasma density profile and density fluctuations at two locations along the probe beam. Basic characteristics of the diagnostics are considered as well as some effects that include dispersion and are critical for two colour imaging technique. The results of the bench-top experiments with the prototype of the interferometer are presented. (author)

  13. CO2 laser diagnostics for measurements of the plasma density profile and plasma density fluctuations on LHD

    International Nuclear Information System (INIS)

    Vyacheslavov, L.N.; Tanaka, K.; Kawahata, K.

    2001-04-01

    A CO 2 laser based diagnostics complimentary to the existing FIR interferometer is proposed. It combines interferometry for plasma density profile measurement under conditions of large density gradients, and both imaging and scattering techniques for observation of plasma fluctuations. Two-colour interferometer with a slablike probe beam and a single multichannel linear detector array provide observation of plasma density profile and density fluctuations at two locations along the probe beam. Basic characteristics of the diagnostics are considered as well as some effects that include dispersion and are critical for two colour imaging technique. The results of the bench-top experiments with the prototype of the interferometer are presented. (author)

  14. Clinical application of exhaled nitric oxide measurement in pediatric lung diseases

    Directory of Open Access Journals (Sweden)

    Manna Angelo

    2012-12-01

    Full Text Available Summary Fractional exhaled nitric oxide (FeNO is a non invasive method for assessing the inflammatory status of children with airway disease. Different ways to measure FeNO levels are currently available. The possibility of measuring FeNO levels in an office setting even in young children, and the commercial availability of portable devices, support the routine use of FeNO determination in the daily pediatric practice. Although many confounding factors may affect its measurement, FeNO is now widely used in the management of children with asthma, and seems to provide significantly higher diagnostic accuracy than lung function or bronchial challenge tests. The role of FeNO in airway infection (e.g. viral bronchiolitis and common acquired pneumonia, in bronchiectasis, or in cases with diffuse lung disease is less clear. This review focuses on the most recent advances and the current clinical applications of FeNO measurement in pediatric lung disease.

  15. Experiment to measure oxygen opacity at high density and temperature

    Science.gov (United States)

    Keiter, Paul; Butler, Hannah; Trantham, Matt; Mussack, Katie; Colgan, James; Fontes, Chris; Guzik, Joyce; Kilcrease, David; Perry, Ted; Orban, Chris; Ducret, Jean-Eric; La Pennec, Maelle; Turck-Chieze, Sylvaine; Mancini, Roberto; Heeter, Robert

    2017-10-01

    In recent years, there has been a debate over the abundances of heavy elements (Z >2) in the solar interior. Recent solar atmosphere models [Asplund 2009] find a significantly lower abundance for C, N, and O compared to models used roughly a decade ago. Recent opacity measurements of iron disagree with opacity model predictions [Bailey et al., 2015]. Repeated scrutiny of the experiment and data has not produced a conclusive reason for the discrepancy. New models have been implemented in the ATOMIC opacity code for low-Z elements [Colgan, 2013, Armstrong 2014], however no data currently exists to test the low-Z material models in the regime relevant to the solar convection zone. We present an experimental design using the opacity platform developed at the National Ignition Facility to study the oxygen opacity at densities and temperatures near the solar convection zone conditions. This work is funded by the U.S. DOE, through the NNSA-DS and SC-OFES Joint Program in HEDLP, Grant Number DE-NA0002956, and the NLUF Program, Grant Number DE-NA0002719, and through the LLE, University of Rochester by the NNSA/OICF under No. DE-NA0001944.

  16. Using quantitative breath sound measurements to predict lung function following resection

    Directory of Open Access Journals (Sweden)

    Keus Leendert

    2010-10-01

    Full Text Available Abstract Background Predicting postoperative lung function is important for estimating the risk of complications and long-term disability after pulmonary resection. We investigated the capability of vibration response imaging (VRI as an alternative to lung scintigraphy for prediction of postoperative lung function in patients with intrathoracic malignancies. Methods Eighty-five patients with intrathoracic malignancies, considered candidates for lung resection, were prospectively studied. The projected postoperative (ppo lung function was calculated using: perfusion scintigraphy, ventilation scintigraphy, and VRI. Two sets of assessments made: one for lobectomy and one for pneumonectomy. Clinical concordance was defined as both methods agreeing that either a patient was or was not a surgical candidate based on a ppoFEV1% and ppoDLCO% > 40%. Results Limits of agreement between scintigraphy and VRI for ppo following lobectomy were -16.47% to 15.08% (mean difference = -0.70%;95%CI = -2.51% to 1.12% and for pneumonectomy were -23.79% to 19.04% (mean difference = -2.38%;95%CI = -4.69% to -0.07%. Clinical concordance between VRI and scintigraphy was 73% for pneumonectomy and 98% for lobectomy. For patients who had surgery and postoperative lung function testing (n = 31, ppoFEV1% using scintigraphic methods correlated with measured postoperative values better than projections using VRI, (adjusted R2 = 0.32 scintigraphy; 0.20 VRI, however the difference between methods failed to reach statistical significance. Limits of agreement between measured FEV1% postoperatively and ppoFEV1% based on perfusion scintigraphy were -16.86% to 23.73% (mean difference = 3.44%;95%CI = -0.29% to 7.16%; based on VRI were -19.56% to 28.99% (mean difference = 4.72%;95%CI = 0.27% to 9.17%. Conclusions Further investigation of VRI as an alternative to lung scintigraphy for prediction of postoperative lung function is warranted.

  17. Quantification of lung surface area using computed tomography

    Directory of Open Access Journals (Sweden)

    Xing Li

    2010-10-01

    Full Text Available Abstract Objective To refine the CT prediction of emphysema by comparing histology and CT for specific regions of lung. To incorporate both regional lung density measured by CT and cluster analysis of low attenuation areas for comparison with histological measurement of surface area per unit lung volume. Methods The histological surface area per unit lung volume was estimated for 140 samples taken from resected lung specimens of fourteen subjects. The region of the lung sampled for histology was located on the pre-operative CT scan; the regional CT median lung density and emphysematous lesion size were calculated using the X-ray attenuation values and a low attenuation cluster analysis. Linear mixed models were used to examine the relationships between histological surface area per unit lung volume and CT measures. Results The median CT lung density, low attenuation cluster analysis, and the combination of both were important predictors of surface area per unit lung volume measured by histology (p Conclusion Combining CT measures of lung density and emphysematous lesion size provides a more accurate estimate of lung surface area per unit lung volume than either measure alone.

  18. Measurement of neoclassically predicted edge current density at ASDEX Upgrade

    Science.gov (United States)

    Dunne, M. G.; McCarthy, P. J.; Wolfrum, E.; Fischer, R.; Giannone, L.; Burckhart, A.; the ASDEX Upgrade Team

    2012-12-01

    Experimental confirmation of neoclassically predicted edge current density in an ELMy H-mode plasma is presented. Current density analysis using the CLISTE equilibrium code is outlined and the rationale for accuracy of the reconstructions is explained. Sample profiles and time traces from analysis of data at ASDEX Upgrade are presented. A high time resolution is possible due to the use of an ELM-synchronization technique. Additionally, the flux-surface-averaged current density is calculated using a neoclassical approach. Results from these two separate methods are then compared and are found to validate the theoretical formula. Finally, several discharges are compared as part of a fuelling study, showing that the size and width of the edge current density peak at the low-field side can be explained by the electron density and temperature drives and their respective collisionality modifications.

  19. Measurement of neoclassically predicted edge current density at ASDEX Upgrade

    International Nuclear Information System (INIS)

    Dunne, M.G.; McCarthy, P.J.; Wolfrum, E.; Fischer, R.; Giannone, L.; Burckhart, A.

    2012-01-01

    Experimental confirmation of neoclassically predicted edge current density in an ELMy H-mode plasma is presented. Current density analysis using the CLISTE equilibrium code is outlined and the rationale for accuracy of the reconstructions is explained. Sample profiles and time traces from analysis of data at ASDEX Upgrade are presented. A high time resolution is possible due to the use of an ELM-synchronization technique. Additionally, the flux-surface-averaged current density is calculated using a neoclassical approach. Results from these two separate methods are then compared and are found to validate the theoretical formula. Finally, several discharges are compared as part of a fuelling study, showing that the size and width of the edge current density peak at the low-field side can be explained by the electron density and temperature drives and their respective collisionality modifications. (paper)

  20. The role of adequate reference materials in density measurements in hemodialysis

    Science.gov (United States)

    Furtado, A.; Moutinho, J.; Moura, S.; Oliveira, F.; Filipe, E.

    2015-02-01

    In hemodialysis, oscillation-type density meters are used to measure the density of the acid component of the dialysate solutions used in the treatment of kidney patients. An incorrect density determination of this solution used in hemodialysis treatments can cause several and adverse events to patients. Therefore, despite the Fresenius Medical Care (FME) tight control of the density meters calibration results, this study shows the benefits of mimic the matrix usually measured to produce suitable reference materials for the density meter calibrations.

  1. The role of adequate reference materials in density measurements in hemodialysis

    International Nuclear Information System (INIS)

    Furtado, A; Moura, S; Filipe, E; Moutinho, J; Oliveira, F

    2015-01-01

    In hemodialysis, oscillation-type density meters are used to measure the density of the acid component of the dialysate solutions used in the treatment of kidney patients. An incorrect density determination of this solution used in hemodialysis treatments can cause several and adverse events to patients. Therefore, despite the Fresenius Medical Care (FME) tight control of the density meters calibration results, this study shows the benefits of mimic the matrix usually measured to produce suitable reference materials for the density meter calibrations

  2. Boron uptake measurements in a rat model for Boron Neutron Capture Therapy of lung tumours

    Energy Technology Data Exchange (ETDEWEB)

    Bortolussi, S., E-mail: silva.bortolussi@pv.infn.i [Department of Nuclear and Theoretical Physics, University of Pavia, via Bassi 6, 27100 Pavia (Italy); National Institute of Nuclear Physics (INFN), Section of Pavia, via Bassi 6, 27100 Pavia (Italy); Bakeine, J.G. [Department of Nuclear and Theoretical Physics, University of Pavia, via Bassi 6, 27100 Pavia (Italy); Ballarini, F. [Department of Nuclear and Theoretical Physics, University of Pavia, via Bassi 6, 27100 Pavia (Italy); National Institute of Nuclear Physics (INFN), Section of Pavia, via Bassi 6, 27100 Pavia (Italy); Bruschi, P. [Department of Nuclear and Theoretical Physics, University of Pavia, via Bassi 6, 27100 Pavia (Italy); Gadan, M.A. [Department of Nuclear and Theoretical Physics, University of Pavia, via Bassi 6, 27100 Pavia (Italy); Comision Nacional de Energia Atomica, Buenos Aires (Argentina); Protti, N.; Stella, S. [Department of Nuclear and Theoretical Physics, University of Pavia, via Bassi 6, 27100 Pavia (Italy); National Institute of Nuclear Physics (INFN), Section of Pavia, via Bassi 6, 27100 Pavia (Italy); Clerici, A.; Ferrari, C.; Cansolino, L.; Zonta, C.; Zonta, A. [Department of Surgery, University of Pavia, via Ferrata 27100 Pavia (Italy); Nano, R. [Department of Animal Biology, University of Pavia, via Ferrata 27100 Pavia (Italy); Altieri, S. [Department of Nuclear and Theoretical Physics, University of Pavia, via Bassi 6, 27100 Pavia (Italy); National Institute of Nuclear Physics (INFN), Section of Pavia, via Bassi 6, 27100 Pavia (Italy)

    2011-02-15

    Lung carcinoma is the leading cause of cancer mortality in the Western countries. Despite the introduction over the last few years of new therapeutic agents, survival from lung cancer has shown no discernible improvement in the last 20 years. For these reasons any efforts to find and validate new effective therapeutic procedures for lung cancer are very timely. The selective boron uptake in the tumour with respect to healthy tissues makes Boron Neutron Capture Therapy a potentially advantageous option in the treatment of tumours that affect whole vital organs, and that are surgically inoperable. To study the possibility of applying BNCT to the treatment of diffuse pulmonary tumours, an animal model for boron uptake measurements in lung metastases was developed. Both healthy and tumour-bearing rats were infused with Boronophenylalanine (BPA) and sacrificed at different time intervals after drug administration. The lungs were extracted, and prepared for boron analysis by neutron autoradiography and {alpha}-spectroscopy. The boron concentrations in tumour and normal lung were plotted as a function of the time elapsed after BPA administration. The concentration in tumour is almost constant within the error bars for all the time intervals of the experiment (1-8 h), while the curve in normal lung decreases after 4 h from BPA infusion. At 4 h, the ratio of boron concentration in tumour to boron concentration in healthy lung is higher than 3, and it stays above this level up to 8 h. Also the images of boron distribution in the samples, obtained by neutron autoradiography, show a selective absorption in the metastases.

  3. MEASURING PROTOPLANETARY DISK GAS SURFACE DENSITY PROFILES WITH ALMA

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Jonathan P.; McPartland, Conor, E-mail: jpw@ifa.hawaii.edu [Institute for Astronomy, University of Hawaii at Manoa, Honolulu, HI 96822 (United States)

    2016-10-10

    The gas and dust are spatially segregated in protoplanetary disks due to the vertical settling and radial drift of large grains. A fuller accounting of the mass content and distribution in disks therefore requires spectral line observations. We extend the modeling approach presented in Williams and Best to show that gas surface density profiles can be measured from high fidelity {sup 13}CO integrated intensity images. We demonstrate the methodology by fitting ALMA observations of the HD 163296 disk to determine a gas mass, M {sub gas} = 0.048 M {sub ⊙}, and accretion disk characteristic size R {sub c} = 213 au and gradient γ = 0.39. The same parameters match the C{sup 18}O 2–1 image and indicate an abundance ratio [{sup 12}CO]/[C{sup 18}O] of 700 independent of radius. To test how well this methodology can be applied to future line surveys of smaller, lower mass T Tauri disks, we create a large {sup 13}CO 2–1 image library and fit simulated data. For disks with gas masses 3–10 M {sub Jup} at 150 pc, ALMA observations with a resolution of 0.″2–0.″3 and integration times of ∼20 minutes allow reliable estimates of R {sub c} to within about 10 au and γ to within about 0.2. Economic gas imaging surveys are therefore feasible and offer the opportunity to open up a new dimension for studying disk structure and its evolution toward planet formation.

  4. A NEW RECIPE FOR OBTAINING CENTRAL VOLUME DENSITIES OF PRESTELLAR CORES FROM SIZE MEASUREMENTS

    International Nuclear Information System (INIS)

    Tassis, Konstantinos; Yorke, Harold W.

    2011-01-01

    We propose a simple analytical method for estimating the central volume density of prestellar molecular cloud cores from their column density profiles. Prestellar cores feature a flat central part of the column density and volume density profiles of the same size indicating the existence of a uniform-density inner region. The size of this region is set by the thermal pressure force which depends only on the central volume density and temperature of the core, and can provide a direct measurement of the central volume density. Thus, a simple length measurement can immediately yield a central density estimate independent of any dynamical model for the core and without the need for fitting. Using the radius at which the column density is 90% of the central value as an estimate of the size of the flat inner part of the column density profile yields an estimate of the central volume density within a factor of two for well-resolved cores.

  5. Density measurement verification for hot mix asphalt concrete pavement construction.

    Science.gov (United States)

    2010-06-01

    Oregon Department of Transportation (ODOT) requires a minimum density for the construction of dense-graded hot mix asphalt concrete (HMAC) pavements to ensure the likelihood that the pavement will not experience distresses that reduce the expected se...

  6. Density measurement verification for hot mixed asphalt concrete pavement construction.

    Science.gov (United States)

    2010-06-01

    Oregon Department of Transportation (ODOT) requires a minimum density for the construction of dense-graded hot mix asphalt concrete (HMAC) pavements to ensure the likelihood that the pavement will not experience distresses that reduce the expected se...

  7. Measurement of acidity and density of plutonium solutions

    International Nuclear Information System (INIS)

    Hofstetter, K.J.; Bowers, D.L.; Kemmerlin, R.P.

    1978-01-01

    The solutions were analyzed for acidity and total Pu concentration at ambient temperature while the density was determined at 25, 35, 45, and 60 0 C. From least squares fitting, it was found that the density could be computed to within 1% of the experimental value using the equation D = 1 + 0.0477[H + ] - 4.25 x 10 -3 [H + ] 2 + 1.477 x 10 -3 [Pu] - (T - 25)/1000

  8. Fetal lung volume measurement by MRI with high-speed imaging systems

    Energy Technology Data Exchange (ETDEWEB)

    Osada, Hisao; Kaku, Kenshi [Chiba Univ. (Japan). Hospital

    2002-08-01

    Although ultrasonography is widely used for fetal morphologic observation, magnetic resonance imaging (MRI) has gained popularity as a new prenatal diagnostic method with recent introduction of high-speed imaging systems. Infants with lung hypoplasia affecting respiratory function require intensive management starting immediately after birth. Therefore, accurate prenatal differential diagnosis and severity evaluation are extremely important for these fetuses. The aim of this study is to measure fetal lung volume using a computer-based, three-dimensional MRI imaging system and to evaluate the possibility of clinical applications of this procedure. A total of 96 fetuses were evaluated, all were morphologically abnormal, and MRI was done for advanced assessment from 24 to 39 weeks gestation. Three-directional views of fetal chest were imaged by Signa Horizon, 1.5 Tesla, version 5.6 (General Electronics) with the following conditions; coil: TORSO coil, sequence: SSFSE (single shot fast spin echo), slice thickness: 5 mm, and imaging speed: 2 seconds/slice. To calculate the lung volume and create three-dimensional image, the lung area in each slice was traced out, then multiplied using computer image processing. Simultaneously, the volumes of all slices were summed to give the volume of each lung. Linear regression analysis and analysis of covariance (ANCOVA) were used for statistical analyses. In all cases, clear images were obtained, and were adequate for three-dimensional evaluation of the fetal lung. Thirty-five fetuses had poor outcomes, such as intrauterine fetal death, neonatal death, and intensive respiratory care. Regression lines of lung volume versus gestational week were calculated for these fetuses with poor outcome and 61 other fetuses with good outcome. ANCOVA, with gestational week as a covariant, revealed a significant intergroup difference in the lung volume (p<0.001). Similarly, regression lines of lung volume versus fetal body weight estimated by

  9. Audiovisual Biofeedback Improves Cine–Magnetic Resonance Imaging Measured Lung Tumor Motion Consistency

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Danny [Radiation Physics Laboratory, Sydney Medical School, The University of Sydney, Sidney, NSW (Australia); Greer, Peter B. [School of Mathematical and Physical Sciences, The University of Newcastle, Newcastle, NSW (Australia); Department of Radiation Oncology, Calvary Mater Newcastle, Newcastle, NSW (Australia); Ludbrook, Joanna; Arm, Jameen; Hunter, Perry [Department of Radiation Oncology, Calvary Mater Newcastle, Newcastle, NSW (Australia); Pollock, Sean; Makhija, Kuldeep; O' brien, Ricky T. [Radiation Physics Laboratory, Sydney Medical School, The University of Sydney, Sidney, NSW (Australia); Kim, Taeho [Radiation Physics Laboratory, Sydney Medical School, The University of Sydney, Sidney, NSW (Australia); Department of Radiation Oncology, Virginia Commonwealth University, Richmond, Virginia (United States); Keall, Paul, E-mail: paul.keall@sydney.edu.au [Radiation Physics Laboratory, Sydney Medical School, The University of Sydney, Sidney, NSW (Australia)

    2016-03-01

    Purpose: To assess the impact of an audiovisual (AV) biofeedback on intra- and interfraction tumor motion for lung cancer patients. Methods and Materials: Lung tumor motion was investigated in 9 lung cancer patients who underwent a breathing training session with AV biofeedback before 2 3T magnetic resonance imaging (MRI) sessions. The breathing training session was performed to allow patients to become familiar with AV biofeedback, which uses a guiding wave customized for each patient according to a reference breathing pattern. In the first MRI session (pretreatment), 2-dimensional cine-MR images with (1) free breathing (FB) and (2) AV biofeedback were obtained, and the second MRI session was repeated within 3-6 weeks (mid-treatment). Lung tumors were directly measured from cine-MR images using an auto-segmentation technique; the centroid and outlier motions of the lung tumors were measured from the segmented tumors. Free breathing and AV biofeedback were compared using several metrics: intra- and interfraction tumor motion consistency in displacement and period, and the outlier motion ratio. Results: Compared with FB, AV biofeedback improved intrafraction tumor motion consistency by 34% in displacement (P=.019) and by 73% in period (P<.001). Compared with FB, AV biofeedback improved interfraction tumor motion consistency by 42% in displacement (P<.046) and by 74% in period (P=.005). Compared with FB, AV biofeedback reduced the outlier motion ratio by 21% (P<.001). Conclusions: These results demonstrated that AV biofeedback significantly improved intra- and interfraction lung tumor motion consistency for lung cancer patients. These results demonstrate that AV biofeedback can facilitate consistent tumor motion, which is advantageous toward achieving more accurate medical imaging and radiation therapy procedures.

  10. Audiovisual Biofeedback Improves Cine–Magnetic Resonance Imaging Measured Lung Tumor Motion Consistency

    International Nuclear Information System (INIS)

    Lee, Danny; Greer, Peter B.; Ludbrook, Joanna; Arm, Jameen; Hunter, Perry; Pollock, Sean; Makhija, Kuldeep; O'brien, Ricky T.; Kim, Taeho; Keall, Paul

    2016-01-01

    Purpose: To assess the impact of an audiovisual (AV) biofeedback on intra- and interfraction tumor motion for lung cancer patients. Methods and Materials: Lung tumor motion was investigated in 9 lung cancer patients who underwent a breathing training session with AV biofeedback before 2 3T magnetic resonance imaging (MRI) sessions. The breathing training session was performed to allow patients to become familiar with AV biofeedback, which uses a guiding wave customized for each patient according to a reference breathing pattern. In the first MRI session (pretreatment), 2-dimensional cine-MR images with (1) free breathing (FB) and (2) AV biofeedback were obtained, and the second MRI session was repeated within 3-6 weeks (mid-treatment). Lung tumors were directly measured from cine-MR images using an auto-segmentation technique; the centroid and outlier motions of the lung tumors were measured from the segmented tumors. Free breathing and AV biofeedback were compared using several metrics: intra- and interfraction tumor motion consistency in displacement and period, and the outlier motion ratio. Results: Compared with FB, AV biofeedback improved intrafraction tumor motion consistency by 34% in displacement (P=.019) and by 73% in period (P<.001). Compared with FB, AV biofeedback improved interfraction tumor motion consistency by 42% in displacement (P<.046) and by 74% in period (P=.005). Compared with FB, AV biofeedback reduced the outlier motion ratio by 21% (P<.001). Conclusions: These results demonstrated that AV biofeedback significantly improved intra- and interfraction lung tumor motion consistency for lung cancer patients. These results demonstrate that AV biofeedback can facilitate consistent tumor motion, which is advantageous toward achieving more accurate medical imaging and radiation therapy procedures.

  11. Measurement and classification of heart and lung sounds by using LabView for educational use.

    Science.gov (United States)

    Altrabsheh, B

    2010-01-01

    This study presents the design, development and implementation of a simple low-cost method of phonocardiography signal detection. Human heart and lung signals are detected by using a simple microphone through a personal computer; the signals are recorded and analysed using LabView software. Amplitude and frequency analyses are carried out for various phonocardiography pathological cases. Methods for automatic classification of normal and abnormal heart sounds, murmurs and lung sounds are presented. Various cases of heart and lung sound measurement are recorded and analysed. The measurements can be saved for further analysis. The method in this study can be used by doctors as a detection tool aid and may be useful for teaching purposes at medical and nursing schools.

  12. Measurement of lung tissue dynamics in artificially ventilated rats with optical coherence tomography

    Directory of Open Access Journals (Sweden)

    Schnabel Christian

    2017-09-01

    Full Text Available Diseases of lung tissue and the airways become a major task for medical care and health care systems in modern industrial countries in the future. Suitable treatment methods and strategies for lung support and artificial ventilation are of dare need. Besides the obvious importance as life-saving intervention, the effects of usually used over-pressure ventilation onto the sensitive alveolar tissue are insufficiently understood. Therefore, it is of great interest to characterize lung tissue during artificial ventilation at the alveolar level. Those measurements can be used to link micromechanics of alveolar structures to mechanical properties of the whole lung like compliance and resistance measured at the ventilator device. This can be done only in animal experiments due to the fact that imaging techniques used in human diagnostics like CT or MRT fail to resolve alveolar tissue structures. The disadvantage of high-resolution techniques like optical coherence tomography (OCT or intravital microscopy (IVM is the need of a surgical access to the lung due to the limitation in penetration depth of these techniques. Furthermore, imaging dynamic processes with high-resolution imaging techniques during uninterrupted artificial ventilation is a challenging task. In this study, we present a measurement setup for combined imaging of conventional pressure-controlled ventilated rats and the visualization of volume changes of alveolar structures during one cycle of breath. A custom-made OCT system in combination with a triggered scanning algorithm was used to acquire time-resolved 3D OCT image data. Furthermore, this system was combined with a self-adapting autofocus function for intravital microscopy to track the lung surface keeping the tissue in focal plane. The combination of new dynamic measurement modes for OCT and IVM allows new insights into alveolar tissue and will promote the understanding of mechanical behavior during artificial ventilation.

  13. Density-based similarity measures for content based search

    Energy Technology Data Exchange (ETDEWEB)

    Hush, Don R [Los Alamos National Laboratory; Porter, Reid B [Los Alamos National Laboratory; Ruggiero, Christy E [Los Alamos National Laboratory

    2009-01-01

    We consider the query by multiple example problem where the goal is to identify database samples whose content is similar to a coUection of query samples. To assess the similarity we use a relative content density which quantifies the relative concentration of the query distribution to the database distribution. If the database distribution is a mixture of the query distribution and a background distribution then it can be shown that database samples whose relative content density is greater than a particular threshold {rho} are more likely to have been generated by the query distribution than the background distribution. We describe an algorithm for predicting samples with relative content density greater than {rho} that is computationally efficient and possesses strong performance guarantees. We also show empirical results for applications in computer network monitoring and image segmentation.

  14. Optical density measurements on the examination of colon cancer tissues

    International Nuclear Information System (INIS)

    Touati, E.; Ajaal, T.; Hamassi, A.

    2015-01-01

    Automated quantitative image analysis can aid in cancer diagnosis and, in general, mange medical treatments managements and improve routine medical diagnosis. Early diagnosis can make big difference between life and death. Microscopic images from two tissue types forty-four normal and fifty-eight cancers, was evaluated based on their ability to identify abnormalities in colon images. Optical density approach is applied to extract parameters that exhibit cancer behavior on colon tissues images. Using statistical toolbox, a significant result of (p<0.0001) for the mean and the variance of the optical density parameter were detected, and only (p<0.001) for skewness optical density. based on linear discrimination method, the obtained result shows 905 accuracy for both sensitivity and specificity, and with an overall accuracy of 90% (author)

  15. Observer variability of absolute and relative thrombus density measurements in patients with acute ischemic stroke

    NARCIS (Netherlands)

    Santos, Emilie M. M.; Yoo, Albert J.; Beenen, Ludo F.; Berkhemer, Olvert A.; den Blanken, Mark D.; Wismans, Carrie; Niessen, Wiro J.; Majoie, Charles B.; Marquering, Henk A.; Fransen, Puck S. S.; Beumer, Debbie; van den Berg, Lucie A.; Lingsma, Hester F.; Schonewille, Wouter J.; Vos, Jan Albert; Nederkoorn, Paul J.; Wermer, Marieke J. H.; van Walderveen, Marianne A. A.; Staals, Julie; Hofmeijer, Jeannette; van Oostayen, Jacques A.; Lycklama à Nijeholt, Geert J.; Boiten, Jelis; Brouwer, Patrick A.; Emmer, Bart J.; de Bruijn, Sebastiaan F.; van Dijk, Lukas C.; Kappelle, L. Jaap; Lo, Rob H.; van Dijk, Ewoud J.; de Vries, Joost; de Kort, Paul L. M.; van den Berg, Jan S. P.; A A M van Hasselt, Boudewijn; Aerden, Leo A. M.; Dallinga, René J.; Visser, Marieke C.; Bot, Joseph C. J.; Vroomen, Patrick C.; Eshghi, Omid; Schreuder, Tobien H. C. M. L.; Heijboer, Roel J. J.; Keizer, Koos; Tielbeek, Alexander V.; Hertog, Heleen M. Den; Gerrits, Dick G.; van den Berg-Vos, Renske M.; Karas, Giorgos B.; Steyerberg, Ewout W.; Flach, H. Zwenneke; Sprengers, Marieke E. S.; Jenniskens, Sjoerd F. M.; van den Berg, René; Koudstaal, Peter J.; van Zwam, Wim H.; Roos, Yvo B. W. E. M.; van der Lugt, Aad; van Oostenbrugge, Robert J.; Dippel, Diederik W. J.

    2016-01-01

    Thrombus density may be a predictor for acute ischemic stroke treatment success. However, only limited data on observer variability for thrombus density measurements exist. This study assesses the variability and bias of four common thrombus density measurement methods by expert and non-expert

  16. Observer variability of absolute and relative thrombus density measurements in patients with acute ischemic stroke

    NARCIS (Netherlands)

    E.M.M. Santos (Emilie M.); A.J. Yoo (Albert J.); L.F.M. Beenen (Ludo); O.A. Berkhemer (Olvert); M.D. Den Blanken (Mark D.); C. Wismans (Carrie); W.J. Niessen (Wiro); C.B. Majoie (Charles); H. Marquering (Henk)

    2016-01-01

    textabstractIntroduction: Thrombus density may be a predictor for acute ischemic stroke treatment success. However, only limited data on observer variability for thrombus density measurements exist. This study assesses the variability and bias of four common thrombus density measurement methods by

  17. Observer variability of absolute and relative thrombus density measurements in patients with acute ischemic stroke

    NARCIS (Netherlands)

    Santos, E.M.; Yoo, A.J.; Beenen, L.F.; Berkhemer, O.A.; Blanken, M.D. den; Wismans, C.; Niessen, W.J.; Majoie, C.B.; Marquering, H.A.; Dijk, E.J. van; et al.,

    2016-01-01

    INTRODUCTION: Thrombus density may be a predictor for acute ischemic stroke treatment success. However, only limited data on observer variability for thrombus density measurements exist. This study assesses the variability and bias of four common thrombus density measurement methods by expert and

  18. Density measurements as a means for detection of semiconductor - metal transitions in melts of chalcogenide systems

    International Nuclear Information System (INIS)

    Thurn, H.; Ruska, J.

    1976-01-01

    It is reported on density measurements from liquidus temperature up to 900 or 1,000 0 C of a number of Se- or Te-containing liquid alloys. Anomalous density variations with temperature were found in many cases. The density measurements have been performed by a γ-ray absorption method. (orig./HK) [de

  19. Effects of the light beam bending on the interferometric electron density measurements

    International Nuclear Information System (INIS)

    Matsumoto, Y.; Koyama, K.; Tanimoto, M.; Sugiura, M.

    1980-01-01

    In the measurements of plasma density profile with laser interferometers, the maximum relative errors due to the deflection of laser light caused by steep gradients of the electron density are analytically evaluated. As an example the errors in the measurements of density profile of a plasma focus by using a UV-N 2 laser are estimated. (author)

  20. Radiologic total lung capacity measurement. Development and evaluation of a computer-based system

    Energy Technology Data Exchange (ETDEWEB)

    Seeley, G.W.; Mazzeo, J.; Borgstrom, M.; Hunter, T.B.; Newell, J.D.; Bjelland, J.C.

    1986-11-01

    The development of a computer-based radiologic total lung capacity (TLC) measurement system designed to be used by non-physician personnel is detailed. Four operators tested the reliability and validity of the system by measuring inspiratory PA and lateral pediatric chest radiographs with a Graf spark pen interfaced to a DEC VAX 11/780 computer. First results suggest that the ultimate goal of developing an accurate and easy to use TLC measurement system for non-physician personnel is attainable.

  1. Measurements of regional lung water with 0-15 labeled water and CO-15 labeled carboxyhemoglobin

    International Nuclear Information System (INIS)

    Helmeke, H.J.; Schober, O.; Lehr, L.; Junker, D.; Meyer, G.J.; Fitschen, J.; Bossaller, C.; Hundeshagen, H.

    1982-01-01

    Determination of regional vascular lung water is only practicable by external imaging since it is the only method which allows analysis of many regions. 0-15 was produced by our medical cyclotron (MC-35) via the N-14(d,n)0-15 reaction and processed to H 2 O-15 as the diffusible and to CO-15-hemiglobin autologous erythrocytes - as the intravascular tracer. The activity over both lungs applied as a bolus into the right atrium (5-10 mCi/1 sec) was followed by a positron camera (4200; Cycl. Corp.). Data acquisition and analysis was done in a pdp 11-55 computer system. Mean transit times were computed by the 'height over area' and the 'ratio of moments' method. The extravascular lung water per unit of plasma volume (ELW/Vp) was calculated according to Fazio et al. (1976).The lungs were divided into six zones. 47 investigations in 27 patients were caried out (controls, patients with heart failure, and critically ill with respiratory distress). As expected critically ill patients (ELW/Vp = 0.39+-0.19/0.66+-0.21) demonstrated a higher ELW/Vp than those suffering from myocardial insufficiency (ELW/V = 0.30+-0.13) or controls (ELW/Vp = 0.22+-0.11). Various factors involved in the measurement of lung water are mentioned. Because of methodological considerations and the worse discrimination concerning of the 'ratio of moments' method we prefer the 'height over area' analysis in the determination of transit times. The scintigraphic estimation of the so defind regional lung water is possible as the discrimination of groups is; the follow up or quantification of regional lung water of a patient in clinical routine work seems to be not yet established under the demonstrated conditions. (Author)

  2. Wood fibre density measurement with 238 Pu radiation

    International Nuclear Information System (INIS)

    Barry, B.J.; Baker, D.B.

    1996-01-01

    The form of the curve of attenuation by wood fibre of the X radiation from 238 Pu has been determined. An exponential function containing a term second order in the areal density of the fibre described the curve accurately. The effect of scatter is negligible, even with an uncollimated radiation beam. (author). 18 refs., 1 tab., 6 figs

  3. Electron momentum density measurements by means of positron annihilation and Compton spectroscopy

    International Nuclear Information System (INIS)

    Gerber, W.; Dlubek, G.; Marx, U.; Bruemmer, O.; Prautzsch, J.

    1982-01-01

    The electron momentum density is measured applying positron annihilation and Compton spectroscopy in order to get information about electron wave functions. Compton spectroscopic measurements of Pd-Ag and Cu-Zn alloy systems are carried out taking into account crystal structure, mixability, and order state. Three-dimensional momentum densities of silicon are determined in order to get better information about its electronic structure. The momentum density and the spin density of ferromagnetic nickel are investigated using angular correlation curves

  4. Measurements of the Fe3+ diffusion coefficient in Fricke Xylenol gel using optical density measurements

    International Nuclear Information System (INIS)

    Nonato de Oliveira, Lucas; Sampaio, Francisco Glaildo Almeida; Moreira, Marcos Vasques; Almeida, Adelaide de

    2014-01-01

    In Fricke dosimetry, optical density measurements are performed some time after dosimeter irradiation. Values of the diffusion coefficient of Fe 3+ in Fricke Xylenol gel (FXG) are necessary for determining the spatial distribution of the absorbed dose from measurements of the optical density. Five sets of FXG dosimeters, kept at different constant temperatures, were exposed to collimated 6 MV photons. The optical density profile, proportional to the Fe 3+ concentration, at the boundary between irradiated and non-irradiated parts of each dosimeter was measured periodically over a period of 60 h. By comparing the experimental data with a function that accounts for the unobserved initial concentration profile of Fe 3+ in the FXG, we obtained diffusion coefficients 0.30±0.05, 0.40±0.05, 0.50±0.05, 0.60±0.05 and 0.80±0.05 mm 2 /h for the temperatures 283.0±0.5, 286.0±0.5, 289.0±0.5, 292.0±0.5, and 296.0±0.5 K, respectively. The activation energy of Fe 3+ diffusion in the gel, 0.54±0.06 eV, was determined from the temperature dependence of the diffusion coefficients. - Highlights: • A new analytical method to determine diffusion coefficients of ions in gels is proposed. • The method is applied for measurements of the diffusion coefficients of Fe 3+ ions in a Fricke gel dosimeter. • Activation energy of the Fe 3+ ions in the gel was found to be 0.54 ±0.06 eV

  5. Thickness gauge for the measurement of the density of graphite

    International Nuclear Information System (INIS)

    Leveque, P.; Gasnier, M.; Hours, R.; Jouquet, G.; Rappeneau, J.; Tanguy, J.C.

    1961-01-01

    A thickness gauge was built, based on absorption of Bremsstrahlung generated in a Be target by a ( 90 Sr + 90 Y) β- source. This allows rapid and precise estimation (95 per cent probable error = 0.7 per cent) of the densities in slabs of graphite having a constant thickness of 25 ± 0.05 mm, the diameter of the beam being about 1 cm. Results obtained in this way are presented. (author) [fr

  6. A brief measure of Smokers' knowledge of lung cancer screening with low-dose computed tomography

    Directory of Open Access Journals (Sweden)

    Lisa M. Lowenstein

    2016-12-01

    Full Text Available We describe the development and psychometric properties of a new, brief measure of smokers' knowledge of lung cancer screening with low-dose computed tomography (LDCT. Content experts identified key facts smokers should know in making an informed decision about lung cancer screening. Sample questions were drafted and iteratively refined based on feedback from content experts and cognitive testing with ten smokers. The resulting 16-item knowledge measure was completed by 108 heavy smokers in Houston, Texas, recruited from 12/2014 to 09/2015. Item difficulty, item discrimination, internal consistency and test-retest reliability were assessed. Group differences based upon education levels and smoking history were explored. Several items were dropped due to ceiling effects or overlapping constructs, resulting in a 12-item knowledge measure. Additional items with high item uncertainty were retained because of their importance in informed decision making about lung cancer screening. Internal consistency reliability of the final scale was acceptable (KR-20 = 0.66 and test-retest reliability of the overall scale was 0.84 (intraclass correlation. Knowledge scores differed across education levels (F = 3.36, p = 0.04, while no differences were observed between current and former smokers (F = 1.43, p = 0.24 or among participants who met or did not meet the 30-pack-year screening eligibility criterion (F = 0.57, p = 0.45. The new measure provides a brief, valid and reliable indicator of smokers' knowledge of key concepts central to making an informed decision about lung cancer screening with LDCT, and can be part of a broader assessment of the quality of smokers' decision making about lung cancer screening.

  7. Optical measurement of isolated canine lung filtration coefficients after alloxan infusion.

    Science.gov (United States)

    Klaesner, J W; Pou, N A; Parker, R E; Finney, C; Roselli, R J

    1998-04-01

    In this study, lung filtration coefficient (Kfc) was measured in eight isolated canine lung preparations by using three methods: standard gravimetric (Std), blood-corrected gravimetric (BC), and optical. The lungs were held in zone III conditions and were subjected to an average venous pressure increase of 8.79 +/- 0.93 (mean +/- SD) cmH2O. The permeability of the lungs was increased with an infusion of alloxan (75 mg/kg). The resulting Kfc values (in milliliters . min-1 . cmH2O-1 . 100 g dry lung weight-1) measured by using Std and BC gravimetric techniques before vs. after alloxan infusion were statistically different: Std, 0.527 +/- 0.290 vs. 1. 966 +/- 0.283; BC, 0.313 +/- 0.290 vs. 1.384 +/- 0.290. However, the optical technique did not show any statistical difference between pre- and postinjury with alloxan, 0.280 +/- 0.305 vs. 0.483 +/- 0. 297, respectively. The alloxan injury, quantified by using multiple-indicator techniques, showed an increase in permeability and a corresponding decrease in reflection coefficient for albumin (sigmaf). Because the optical method measures the product of Kfc and sigmaf, this study shows that albumin should not be used as an intravascular optical filtration marker when permeability is elevated. However, the optical technique, along with another means of measuring Kfc (such as BC), can be used to calculate the sigmaf of a tracer (in this study, sigmaf of 0.894 at baseline and 0.348 after injury). Another important finding of this study was that the ratio of baseline-to-injury Kfc values was not statistically different for Std and BC techniques, indicating that the percent contribution of slow blood-volume increases does not change because of injury.

  8. Evaluation of measurement precision errors at different bone density values

    International Nuclear Information System (INIS)

    Wilson, M.; Wong, J.; Bartlett, M.; Lee, N.

    2002-01-01

    Full text: The precision error commonly used in serial monitoring of BMD values using Dual Energy X Ray Absorptometry (DEXA) is 0.01-0.015g/cm - for both the L2 L4 lumbar spine and total femur. However, this limit is based on normal individuals with bone densities similar to the population mean. The purpose of this study was to systematically evaluate precision errors over the range of bone density values encountered in clinical practice. In 96 patients a BMD scan of the spine and femur was immediately repeated by the same technologist with the patient taken off the bed and repositioned between scans. Nine technologists participated. Values were obtained for the total femur and spine. Each value was classified as low range (0.75-1.05 g/cm ) and medium range (1.05- 1.35g/cm ) for the spine, low range (0.55 0. 85 g/cm ) and medium range (0.85-1.15 g/cm ) for the total femur. Results show that the precision error was significantly lower in the medium range for total femur results with the medium range value at 0.015 g/cm - and the low range at 0.025 g/cm - (p<0.01). No significant difference was found for the spine results. We also analysed precision errors between three technologists and found a significant difference (p=0.05) occurred between only two technologists and this was seen in the spine data only. We conclude that there is some evidence that the precision error increases at the outer limits of the normal bone density range. Also, the results show that having multiple trained operators does not greatly increase the BMD precision error. Copyright (2002) The Australian and New Zealand Society of Nuclear Medicine Inc

  9. Quantitatively measuring the orbital angular momentum density of light : Presentation

    CSIR Research Space (South Africa)

    Dudley, Angela L

    2013-08-01

    Full Text Available the orbital angular momentum density of light Angela Dudleya, Christian Schulzeb, Igor Litvina, Michael Duparréb and Andrew Forbes*a,c,d a CSIR National Laser Centre, PO Box 395, Pretoria 0001, South Africa; b Institute of Applied Optics, Friedrich...., “Generation of high-order Bessel beams by use of an axicon,” Opt. Commun. 177(1-6), 297–301 (2000). [3] Sztul, H. I. and Alfano, R. R., “The Poynting vector and angular momentum of Airy beams,” Opt. Express 16(13), 9411–9416 (2008). [4] Allen, L...

  10. Correlation between Podoplanin-positive Lymphatic Microvessel Density 
and CT Characteristics of Non-small Cell Lung Cancer

    Directory of Open Access Journals (Sweden)

    Hui ZHOU

    2012-01-01

    Full Text Available Background and objective It has been proven that ymphatic microvessel density (LMVD was closely correlated with the lymphatic metastasis of non-small cell lung cancer (NSCLC. The aim of the present study is to explore the relationship between podoplanin-LMVD and multi-slice spiral computed tomography (MSCT characteristics of NSCLC. Methods MSCT scanning was performed on 34 cases of NSCLC (squamous carcinoma, 15 cases; adenocarcinoma, 15 cases; and adenosquamous carcinoma, 4 cases prior to operation. Clinical pathology results, including lymph node metastasis, were obtained. CT characteristics, such as shape of the edge, internal structure, and adjacent structures, were described. LMVD in the central and peripheral areas examined respectively using SP immunohistochemical technique were analyzed. Results Lymph node metastasis was found to be associated with LMVD in the peripheral areas. LMVD in the peripheral areas of the resected lesions, the MSCT findings of which included spinous process, pleural indentation, and carcinomatous lymphangitis, was higher than that of the lesions without these MSCT characteristics (P<0.05. Conclusion MSCT findings of spinous process, pleural indentation, or carcinomatous lymphangitis of NSCLC may suggest a higher level of tumor lymphangiogenesis with a higher risk of lymph node metastasis.

  11. Characterizing functional lung heterogeneity in COPD using reference equations for CT scan-measured lobar volumes.

    Science.gov (United States)

    Come, Carolyn E; Diaz, Alejandro A; Curran-Everett, Douglas; Muralidhar, Nivedita; Hersh, Craig P; Zach, Jordan A; Schroeder, Joyce; Lynch, David A; Celli, Bartolome; Washko, George R

    2013-06-01

    CT scanning is increasingly used to characterize COPD. Although it is possible to obtain CT scan-measured lung lobe volumes, normal ranges remain unknown. Using COPDGene data, we developed reference equations for lobar volumes at maximal inflation (total lung capacity [TLC]) and relaxed exhalation (approximating functional residual capacity [FRC]). Linear regression was used to develop race-specific (non-Hispanic white [NHW], African American) reference equations for lobar volumes. Covariates included height and sex. Models were developed in a derivation cohort of 469 subjects with normal pulmonary function and validated in 546 similar subjects. These cohorts were combined to produce final prediction equations, which were applied to 2,191 subjects with old GOLD (Global Initiative for Chronic Obstructive Lung Disease) stage II to IV COPD. In the derivation cohort, women had smaller lobar volumes than men. Height positively correlated with lobar volumes. Adjusting for height, NHWs had larger total lung and lobar volumes at TLC than African Americans; at FRC, NHWs only had larger lower lobes. Age and weight had no effect on lobar volumes at TLC but had small effects at FRC. In subjects with COPD at TLC, upper lobes exceeded 100% of predicted values in GOLD II disease; lower lobes were only inflated to this degree in subjects with GOLD IV disease. At FRC, gas trapping was severe irrespective of disease severity and appeared uniform across the lobes. Reference equations for lobar volumes may be useful in assessing regional lung dysfunction and how it changes in response to pharmacologic therapies and surgical or endoscopic lung volume reduction.

  12. A straightforward method for measuring the range of apparent density of microplastics.

    Science.gov (United States)

    Li, Lingyun; Li, Mengmeng; Deng, Hua; Cai, Li; Cai, Huiwen; Yan, Beizhan; Hu, Jun; Shi, Huahong

    2018-10-15

    Density of microplastics has been regarded as the primary property that affect the distribution and bioavailability of microplastics in the water column. For measuring the density of microplastis, we developed a simple and rapid method based on density gradient solutions. In this study, we tested four solvents to make the density gradient solutions, i.e., ethanol (0.8 g/cm 3 ), ultrapure water (1.0 g/cm 3 ), saturated NaI (1.8 g/cm 3 ) and ZnCl 2 (1.8 g/cm 3 ). Density of microplastics was measured via observing the float or sink status in the density gradient solutions. We found that density gradient solutions made from ZnCl 2 had a larger uncertainty in measuring density than that from NaI, most likely due to a higher surface tension of ZnCl 2 solution. Solutions made from ethanol, ultrapure water, and NaI showed consistent density results with listed densities of commercial products, indicating that these density gradient solutions were suitable for measuring microplastics with a density range of 0.8-1.8 g/cm 3 . Copyright © 2018 Elsevier B.V. All rights reserved.

  13. Implementation of 252Cf-source-driven power spectrum density measurement system

    International Nuclear Information System (INIS)

    Ren Yong; Wei Biao; Feng Peng; Li Jiansheng; Ye Cenming

    2012-01-01

    The principle of 252 Cf-source-driven power spectrum density measurement method is introduced. A measurement system and platform is realized accordingly, which is a combination of hardware and software, for measuring nuclear parameters. The detection method of neutron pulses based on an ultra-high-speed data acquisition card (three channels, 1 GHz sampling rate, 1 ns synchronization) is described, and the data processing process and the power spectrum density algorithm on PC are designed. This 252 Cf-source-driven power spectrum density measurement system can effectively obtain the nuclear tag parameters of nuclear random processes, such as correlation function and power spectrum density. (authors)

  14. The estimation of heavy metal concentration in FBR reprocessing solvent streams by density measurement

    International Nuclear Information System (INIS)

    Brown, M.L.; Savage, D.J.

    1986-04-01

    The application of density measurement to heavy metal monitoring in the solvent phase is described, including practical experience gained during three fast reactor fuel reprocessing campaigns. An experimental algorithm relating heavy metal concentration and sample density was generated from laboratory-measured density data, for uranyl nitrate dissolved in nitric acid loaded tri-butyl phosphate in odourless kerosene. Differences in odourless kerosene batch densities are mathematically interpolated, and the algorithm can be used to estimate heavy metal concentrations from the density to within +1.5 g/l. An Anton Paar calculating digital densimeter with remote cell operation was used for all density measurements, but the algorithm will give similar accuracy with any density measuring device capable of a precision of better than 0.0005 g/cm 3 . For plant control purposes, the algorithm was simplified using a density referencing system, whereby the density of solvent not yet loaded with heavy metal is subtracted from the sample density. This simplified algorithm compares very favourably with empirical algorithms, derived from numerical analysis of density data and chemically measured uranium and plutonium data obtained during fuel reprocessing campaigns, particularly when differences in the acidity of the solvent are considered before and after loading with heavy metal. This simplified algorithm had been successfully used for plant control of heavy metal loaded solvent during four fast reactor fuel reprocessing campaigns. (author)

  15. Extravascular lung water: its measurement by simultaneous pulmonary and aortic sampling and iterative convolution

    International Nuclear Information System (INIS)

    Giuntini, C.; Fazio, F.

    1975-01-01

    The inadequacy of the apparent distribution volume of THO during the first passage dilution curve (a) to account for the total lung water in in-vitro measurements in dogs and (b) to measure any increase in lung water, even in patients with obvious clinical pulmonary oedema, prompted the present investigation. Tritiated water, THO, as diffusible indicator, and human serum albumin labelled with 131 I, ALB, as intravascular tracer, are injected into the superior vena cava at the junction with the right atrium. In order to clear the aortic blood samples of recirculation, the recirculating tracers must be determined. This is accomplished by pulmonary artery sampling. Iterative convolution of the pulmonary artery dilution curves with suitable test functions eventually yields products of convolution that fit well the corresponding aortic dilution curves of THO and ALB. The test functions that yield the best fit are taken to represent the frequency functions of the transit time from pulmonary artery to aorta of THO and ALB, respectively. By applying the same procedure of iterative convolution to these frequency functions, we obtain the dilution curve of THO in the extravascular lung space. As a result of this analysis: (a) forward extrapolation is less subject to systematic errors such as overestimation of the mean transit time of ALB, i.e. of the tracer that recirculates more; and (b) the distribution volume of THO can be better defined since the dilution of THO in the extravascular lung space may be followed beyond the point of recirculation. The results indicate that both in normal subjects and in patients with left ventricular insufficiency the computed dilution curves of THO in the extravascular lung space have a long tail which is more pronounced in the patients. These findings suggest the existence in the lungs of extravascular water pools that are slowly exchanging with pulmonary water flow. This may depend both on inhomogeneities of perfusion, with lack of it at

  16. In situ/non-contact superfluid density measurement apparatus

    Science.gov (United States)

    Nam, Hyoungdo; Su, Ping-Hsang; Shih, Chih-Kang

    2018-04-01

    We present a double-coil apparatus designed to operate with in situ capability, which is strongly desired for superconductivity studies on recently discovered two-dimensional superconductors. Coupled with a scanning tunneling microscope, the study of both local and global superconductivity [for superconducting gap and superfluid density (SFD), respectively] is possible on an identical sample without sample degradations due to damage, contamination, or oxidation in an atmosphere. The performance of the double-coil apparatus was tested on atomically clean surfaces of non-superconducting Si(111)-7 × 7 and on superconducting films of 100 nm-thick Pb and 1.4 nm-ultrathin Pb. The results clearly show the normal-to-superconductor phase transition for Pb films with a strong SFD.

  17. Euthanasia and Lavage Mediated Effects on Bronchoalveolar Measures of Lung Injury and Inflammation.

    Science.gov (United States)

    Tighe, Robert M; Birukova, Anastasiya; Yeager, Michael J; Reece, Sky W; Gowdy, Kymberly M

    2018-02-26

    Accurate and reproducible assessments of experimental lung injury and inflammation are critical to basic and translational research. In particular, investigators use varied methods of bronchoalveolar lavage and euthanasia but their impact to assessments of injury and inflammation are unknown. To define potential effects, we compared methods of lavage and euthanasia in uninjured mice and following a mild lung injury model (ozone). C57BL/6J male mice age 8-10 weeks underwent BAL following euthanasia with ketamine/xylazine, carbon dioxide (C0 2 ), or isoflurane. BAL methods included 800-μL instilled and withdrawn three times, and 1 or 3 passive fill(s) and drainage to 20cm H20. Parallel experiments were performed 24hr following 3hr of ozone (O 3 ) exposure at 2 parts per million (ppm). BAL total cell counts/differentials and total protein/albumin were determined. Lung histology was evaluated for lung inflammation/injury. BAL cells were cultured and stimulated with PBS, phorbol myristate acetate (PMA) or lipopolysaccharide (LPS) for 4hr and supernatants were evaluated for cytokine content. In uninjured mice, we observed differences due to the lavage and euthanasia methods. The lavage method increased uninjured and O 3 exposure total cells and total protein/albumin with 800-μL instillation having the highest values. Isoflurane increased uninjured total BAL cells, while C0 2 euthanasia increased the uninjured total protein/albumin levels. These effects limited the ability to detect differences in BAL injury measures following O 3 exposure. In conclusion, the method of lavage and euthanasia affects measures of lung inflammation/injury and should be considered a variable in model assessment.

  18. Direct measurements of neutral density depletion by two-photon absorption laser-induced fluorescence spectroscopy

    International Nuclear Information System (INIS)

    Aanesland, A.; Liard, L.; Leray, G.; Jolly, J.; Chabert, P.

    2007-01-01

    The ground state density of xenon atoms has been measured by spatially resolved laser-induced fluorescence spectroscopy with two-photon excitation in the diffusion chamber of a magnetized Helicon plasma. This technique allows the authors to directly measure the relative variations of the xenon atom density without any assumptions. A significant neutral gas density depletion was measured in the core of the magnetized plasma, in agreement with previous theoretical and experimental works. It was also found that the neutral gas density was depleted near the radial walls

  19. Foveal cone spacing and cone photopigment density difference: objective measurements in the same subjects.

    Science.gov (United States)

    Marcos, S; Tornow, R P; Elsner, A E; Navarro, R

    1997-07-01

    Foveal cone spacing was measured in vivo using an objective technique: ocular speckle interferometry. Cone packing density was computed from cone spacing data. Foveal cone photopigment density difference was measured in the same subjects using retinal densitometry with a scanning laser ophthalmoscope. Both the cone packing density and cone photopigment density difference decreased sharply with increasing retinal eccentricity. From the comparison of both sets of measurements, the computed amounts of photopigment per cone increased slightly with increasing retinal eccentricity. Consistent with previous results, decreases in cone outer segment length are over-compensated by an increase in the outer segment area, at least in retinal eccentricities up to 1 deg.

  20. Addition of internal electrodes is beneficial for focused bioimpedance measurements in the lung.

    Science.gov (United States)

    Orschulik, Jakob; Hochhausen, Nadine; Czaplik, Michael; Teichmann, Daniel; Leonhardt, Steffen; Walter, Marian

    2018-03-29

    Bioimpedance measurements such as bioimpedance spectroscopy (BIS) or electrical impedance tomography (EIT) are used in many biomedical applications. While BIS measures and analyzes the impedance in a frequency range at constant electrode positions, EIT aims to reconstruct images of the conductivity distribution from multiple measurements at different electrode positions. Our aim is to add spatial information to tetrapolar BIS measurements by using electrode positions that focus measurements on desired regions of interest. In this paper, we aim to investigate, whether internal electrodes that can be integrated into breathing or gastroesophageal tubes, can improve the local sensitivity of bioimpedance spectroscopy measurements. We present the results of a simulation study, in which we investigated more than 4 M different electrode configurations on their ability to monitor specific regions of interest (ROI) in the lung. Based on the sensitivity, which describes the impact of a conductivity change on the measured impedance, we define three main criteria which we use to evaluate our simulation results: the selectivity [Formula: see text], which describes the impact of a conductivity change inside the region of interest compared to a conductivity change outside the ROI; the homogeneity [Formula: see text], which describes the distribution of the sensitivity inside the ROI; and the absolute impedance contribution ratio [Formula: see text], which describes the contribution of the ROI to the measured impedance. Depending on the region of interest, electrode configurations using internal electrodes are between 9.8 % and 90 % better with respect to these criteria than configurations using external electrodes only. The combination of internal and external electrodes improves the focusing ability of tetrapolar impedance measurements on specific lung regions, which may be especially beneficial for lung monitoring in intensive care.

  1. Observer variability of absolute and relative thrombus density measurements in patients with acute ischemic stroke

    International Nuclear Information System (INIS)

    Santos, Emilie M.M.; Yoo, Albert J.; Beenen, Ludo F.; Majoie, Charles B.; Berkhemer, Olvert A.; Blanken, Mark D. den; Wismans, Carrie; Niessen, Wiro J.; Marquering, Henk A.

    2016-01-01

    Thrombus density may be a predictor for acute ischemic stroke treatment success. However, only limited data on observer variability for thrombus density measurements exist. This study assesses the variability and bias of four common thrombus density measurement methods by expert and non-expert observers. For 132 consecutive patients with acute ischemic stroke, three experts and two trained observers determined thrombus density by placing three standardized regions of interest (ROIs) in the thrombus and corresponding contralateral arterial segment. Subsequently, absolute and relative thrombus densities were determined using either one or three ROIs. Intraclass correlation coefficient (ICC) was determined, and Bland-Altman analysis was performed to evaluate interobserver and intermethod agreement. Accuracy of the trained observer was evaluated with a reference expert observer using the same statistical analysis. The highest interobserver agreement was obtained for absolute thrombus measurements using three ROIs (ICCs ranging from 0.54 to 0.91). In general, interobserver agreement was lower for relative measurements, and for using one instead of three ROIs. Interobserver agreement of trained non-experts and experts was similar. Accuracy of the trained observer measurements was comparable to the expert interobserver agreement and was better for absolute measurements and with three ROIs. The agreement between the one ROI and three ROI methods was good. Absolute thrombus density measurement has superior interobserver agreement compared to relative density measurement. Interobserver variation is smaller when multiple ROIs are used. Trained non-expert observers can accurately and reproducibly assess absolute thrombus densities using three ROIs. (orig.)

  2. Observer variability of absolute and relative thrombus density measurements in patients with acute ischemic stroke

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Emilie M.M. [Erasmus MC - University Medical Center Rotterdam, Department of Radiology, P.O. Box 2040, Rotterdam (Netherlands); Department of Radiology, AMC, Amsterdam (Netherlands); Yoo, Albert J. [Texas Stroke Institute, Plano, TX (United States); Beenen, Ludo F.; Majoie, Charles B. [Department of Radiology, AMC, Amsterdam (Netherlands); Berkhemer, Olvert A. [Department of Radiology, AMC, Amsterdam (Netherlands); Department of Neurology, Erasmus MC, Rotterdam (Netherlands); Blanken, Mark D. den; Wismans, Carrie [AMC, Department of Biomedical Engineering and Physics, Amsterdam (Netherlands); Niessen, Wiro J. [Erasmus MC - University Medical Center Rotterdam, Department of Radiology, P.O. Box 2040, Rotterdam (Netherlands); Delft University of Technology, Faculty of Applied Sciences, Delft (Netherlands); Marquering, Henk A. [Department of Radiology, AMC, Amsterdam (Netherlands); AMC, Department of Biomedical Engineering and Physics, Amsterdam (Netherlands); Collaboration: on behalf of the MR CLEAN investigators

    2016-02-15

    Thrombus density may be a predictor for acute ischemic stroke treatment success. However, only limited data on observer variability for thrombus density measurements exist. This study assesses the variability and bias of four common thrombus density measurement methods by expert and non-expert observers. For 132 consecutive patients with acute ischemic stroke, three experts and two trained observers determined thrombus density by placing three standardized regions of interest (ROIs) in the thrombus and corresponding contralateral arterial segment. Subsequently, absolute and relative thrombus densities were determined using either one or three ROIs. Intraclass correlation coefficient (ICC) was determined, and Bland-Altman analysis was performed to evaluate interobserver and intermethod agreement. Accuracy of the trained observer was evaluated with a reference expert observer using the same statistical analysis. The highest interobserver agreement was obtained for absolute thrombus measurements using three ROIs (ICCs ranging from 0.54 to 0.91). In general, interobserver agreement was lower for relative measurements, and for using one instead of three ROIs. Interobserver agreement of trained non-experts and experts was similar. Accuracy of the trained observer measurements was comparable to the expert interobserver agreement and was better for absolute measurements and with three ROIs. The agreement between the one ROI and three ROI methods was good. Absolute thrombus density measurement has superior interobserver agreement compared to relative density measurement. Interobserver variation is smaller when multiple ROIs are used. Trained non-expert observers can accurately and reproducibly assess absolute thrombus densities using three ROIs. (orig.)

  3. Estimating tree bole and log weights from green densities measured with the Bergstrom Xylodensimeter.

    Science.gov (United States)

    Dale R. Waddell; Michael B. Lambert; W.Y. Pong

    1984-01-01

    The performance of the Bergstrom xylodensimeter, designed to measure the green density of wood, was investigated and compared with a technique that derived green densities from wood disk samples. In addition, log and bole weights of old-growth Douglas-fir and western hemlock were calculated by various formulas and compared with lifted weights measured with a load cell...

  4. Study on Method of Asphalt Density Measurement Using Low Level Radioactive Isotope

    International Nuclear Information System (INIS)

    Chung, Jin-young; Kim, Jung-hoon; Whang, Joo-ho

    2008-01-01

    The fundamental cause of damage to road pavement is insufficient management of asphalt density during construction. Currently, asphalt density in Korea is measured in a laboratory by extracting a core sample after construction. This method delays the overall time of measurement and therefore it is difficult to achieve real-time density management. Using a radioactive isotope for measuring asphalt density during construction reduces measuring time thus enabling realtime measurement. Also, it is provided reliable density measurement to achieve effective density management at work sites. However, existing radiological equipment has not been widely used because of management restrictions and regulations due to the high radiation dose. In this study, we employed a non-destructive method for density measurement. Density is measured by using a portable gamma-ray backscatter device having a radioactivity emission of 100 μCi or less (notice No. 2002-23, Ministry of Science and Technology, standards on radiation protection, etc.), a sealed radioactive source subject to declaration

  5. A microwave interferometer for density measurement and stabilization in process plasmas

    International Nuclear Information System (INIS)

    Pearson, D.I.C.; Campbell, G.A.; Domier, C.W.

    1988-01-01

    A low-cost heterodyne microwave interferometer system capable of measuring and/or controlling the plasma density over a dynamic range covering two orders of magnitude is demonstrated. The microwave frequency is chosen to match the size and density of plasma to be monitored. Large amplitude, high frequency fluctuations can be quantitatively followed and the longer-time-scale density can be held constant over hours of operation, for example during an inline production process to maintain uniformity and stoichiometry of films. A linear relationship is shown between plasma density and discharge current in a specific plasma device. This simple relationship makes control of the plasma straightforward using the interferometer as a density monitor. Other plasma processes could equally well benefit from such density control capability. By combining the interferometer measurement with diagnostics such as probes or optical spectroscopy, the total density profile and the constituent proportions of the various species in the plasma could be determined

  6. Correction for ‘artificial’ electron disequilibrium due to cone-beam CT density errors: implications for on-line adaptive stereotactic body radiation therapy of lung

    International Nuclear Information System (INIS)

    Disher, Brandon; Hajdok, George; Craig, Jeff; Gaede, Stewart; Battista, Jerry J; Wang, An

    2013-01-01

    Cone-beam computed tomography (CBCT) has rapidly become a clinically useful imaging modality for image-guided radiation therapy. Unfortunately, CBCT images of the thorax are susceptible to artefacts due to scattered photons, beam hardening, lag in data acquisition, and respiratory motion during a slow scan. These limitations cause dose errors when CBCT image data are used directly in dose computations for on-line, dose adaptive radiation therapy (DART). The purpose of this work is to assess the magnitude of errors in CBCT numbers (HU), and determine the resultant effects on derived tissue density and computed dose accuracy for stereotactic body radiation therapy (SBRT) of lung cancer. Planning CT (PCT) images of three lung patients were acquired using a Philips multi-slice helical CT simulator, while CBCT images were obtained with a Varian On-Board Imaging system. To account for erroneous CBCT data, three practical correction techniques were tested: (1) conversion of CBCT numbers to electron density using phantoms, (2) replacement of individual CBCT pixel values with bulk CT numbers, averaged from PCT images for tissue regions, and (3) limited replacement of CBCT lung pixels values (LCT) likely to produce artificial lateral electron disequilibrium. For each corrected CBCT data set, lung SBRT dose distributions were computed for a 6 MV volume modulated arc therapy (VMAT) technique within the Philips Pinnacle treatment planning system. The reference prescription dose was set such that 95% of the planning target volume (PTV) received at least 54 Gy (i.e. D95). Further, we used the relative depth dose factor as an a priori index to predict the effects of incorrect low tissue density on computed lung dose in regions of severe electron disequilibrium. CT number profiles from co-registered CBCT and PCT patient lung images revealed many reduced lung pixel values in CBCT data, with some pixels corresponding to vacuum (−1000 HU). Similarly, CBCT data in a plastic lung

  7. Local density measurement of additive manufactured copper parts by instrumented indentation

    Science.gov (United States)

    Santo, Loredana; Quadrini, Fabrizio; Bellisario, Denise; Tedde, Giovanni Matteo; Zarcone, Mariano; Di Domenico, Gildo; D'Angelo, Pierpaolo; Corona, Diego

    2018-05-01

    Instrumented flat indentation has been used to evaluate local density of additive manufactured (AM) copper samples with different relative density. Indentations were made by using tungsten carbide (WC) flat pins with 1 mm diameter. Pure copper powders were used in a selective laser melting (SLM) machine to produce samples to test. By changing process parameters, samples density was changed from the relative density of 63% to 71%. Indentation tests were performed on the xy surface of the AM samples. In order to make a correlation between indentation test results and sample density, the indentation pressure at fixed displacement was selected. Results show that instrumented indentation is a valid technique to measure density distribution along the geometry of an SLM part. In fact, a linear trend between indentation pressure and sample density was found for the selected density range.

  8. The effect of different lung densities on the accuracy of various radiotherapy dose calculation methods: implications for tumour coverage

    DEFF Research Database (Denmark)

    Aarup, Lasse Rye; Nahum, Alan E; Zacharatou, Christina

    2009-01-01

    PURPOSE: To evaluate against Monte-Carlo the performance of various dose calculations algorithms regarding lung tumour coverage in stereotactic body radiotherapy (SBRT) conditions. MATERIALS AND METHODS: Dose distributions in virtual lung phantoms have been calculated using four commercial Treatm...... target dose, the AAA(Ecl) and CCC(OMP) algorithms appear to be adequate alternatives to MC....

  9. Efficacy of lung ventilation scintigram and exercise pulmonary hemodynamic measurement to evaluate operability for pulmonary resection

    International Nuclear Information System (INIS)

    Kaneda, Masanori; Hayashi, Takashi; Hiraiwa, Takane; Sakai, Takashi; Namikawa, Shoji; Kusakawa, Minoru.

    1989-01-01

    Preoperative evaluation of patients with lung cancer should include data concerning both resectability and operability. Operability addresses the question how much pulmonary tissue can be safely removed. The purpose of this study is to demonstrate an efficacy of the lung ventilation scintigram and measurement of exercise change in pulmonary hemodynamic parameters by detecting respiratory and circulatory reserve of pulmonary function. Predicted postoperative forced vital capacity (FVC) were calculated from the data of lung scintigram and preoperative spirometry by means of subsegmental formula. Accuracy of prediction was confirmed by spirometry 6 months after the operation. Correlation coefficient between predicted value and actually measured one was R=0.95, and simple regression formula was y=0.98x-10.4. It was recommended that the lower limit should be setted at 40% by the calculated postoperative %FVC. Exercise test were performed by means of bicycle ergometer with the measurement of pulmonary arterial pressure and cardiac output. Pulmonary arterial resistance index (PARI) were also calculated. In younger group rise of pulmonary arterial pressure during exercise was gentle, and PARI was settled between 150 to 200 in high output state. But in older group rise of pulmonary aerial pressure was steep and PARI was over 200 in some cases, just like the case of COLD. It should be recommended to set the upper limit of PARI at 400 in maximum exercise. (author)

  10. Lung function and functional capacity among foundry workers using effective risk control measures.

    Science.gov (United States)

    Bernardes, Rosane Andrea Bretas; Chiavegato, Luciana Dias; de Moraes, Mônica Vasconcelos; Negreiros, Alexandher; Padula, Rosimeire Simprini

    2015-01-01

    Inhaled dust in the environment can trigger specific reactions in the airways and cause various respiratory diseases. Evaluate the lung function and functional capacity of foundry workers who are exposed to metals and use effective control measures. A cross-sectional study was realized with 108 workers at a bronze foundry and machining plant and in maintenance at a private university, both in Brazil. The workers were divided into two groups: the study group exposed to metals but using risk control measues and a control group not exposed to metal work. The Medical Research Council Questionnaire on Respiratory Symptoms and the International Physical Activity Questionnaire were administered, and lung function and functional capacity were evaluated. Comparative statistics were used to identify differences in the outcome measures between the two groups. The groups had similar personal and anthropometric characteristics and time on the job. Spirometry and peak expiratory flow presented no significant differences between the groups. And there was also no statistically significant difference between groups in functional capacity as assessed by performance on the six-minute walk test. Foundry industry workers in Brazil who were exposed to metal but used risk control measures had similar lung function and functional capacity when compared to the control group who were not exposed to metal. This is a positive results and maybe related to age, time exposure and control of occupational hazards. However, these workers need to continue being monitored in longitudinal studies.

  11. Measurement of the density profile of pure and seeded molecular beams by femtosecond ion imaging

    Energy Technology Data Exchange (ETDEWEB)

    Meng, Congsen [LaserLaB Amsterdam, VU University Amsterdam, de Boelelaan 1083, 1081 HV Amsterdam (Netherlands); Department of Physics, National University of Defense Technology, Changsha 410073 (China); Janssen, Maurice H. M. [LaserLaB Amsterdam, VU University Amsterdam, de Boelelaan 1083, 1081 HV Amsterdam (Netherlands)

    2015-02-15

    Here, we report on femtosecond ion imaging experiments to measure the density profile of a pulsed supersonic molecular beam. Ion images are measured for both a molecular beam and bulk gas under identical experimental conditions via femtosecond multiphoton ionization of Xe atoms. We report the density profile of the molecular beam, and the measured absolute density is compared with theoretical calculations of the centre line beam density. Subsequently, we discuss reasons accounting for the differences between measurements and calculations and propose that strong skimmer interference is the most probable cause for the differences. Furthermore, we report on experiments measuring the centre line density of seeded supersonic beams. The femtosecond ion images show that seeding the heavy Xe atom at low relative seed fractions (1%-10%) in a light carrier gas like Ne results in strong relative enhancements of up to two orders of magnitude.

  12. Distinguishing radiation fibrosis from tumour recurrence after stereotactic ablative radiotherapy (SABR) for lung cancer: A quantitative analysis of CT density changes

    Energy Technology Data Exchange (ETDEWEB)

    Mattonen, Sarah A.; Ward, Aaron D. [Dept. of Medical Biophysics, Univ. of Western Ontario, London, Ontario (Canada); Palma, David A. [Dept. of Radiation Oncology, London Regional Cancer Program, London, Ontario (Canada)], E-mail: david.palma@lhsc.on.ca; Haasbeek, Cornelis J. A.; Senan, Suresh [Dept. of Radiation Oncology, VU Univ. Medical Center, Amsterdam (Netherlands)

    2013-06-15

    Background. For patients treated with stereotactic ablative radiotherapy (SABR) for early-stage non-small cell lung cancer, benign computed tomography (CT) changes due to radiation-induced lung injury (RILI) can be difficult to differentiate from recurrence. We measured the utility of CT image feature analysis in differentiating RILI from recurrence, compared to Response Evaluation Criteria In Solid Tumours (RECIST). Materials and methods. Twenty-two patients with 24 lesions treated with SABR were selected (11 with recurrence, 13 with substantial RILI). On each follow-up CT, consolidative changes and ground glass opacities (GGO) were contoured. For each lesion, contoured regions were analysed for mean and variation in Hounsfi eld units (HU), 3D volume, and RECIST size during follow-up. Results . One hundred and thirtysix CT scans were reviewed, with a median imaging follow-up of 26 months. The 3D volume and RECIST measures of consolidative changes could significantly distinguish recurrence from RILI, but not until 15 months post-SABR; mean volume at 15 months [all values {+-}95% confidence interval (CI)] of 30.1 {+-} 19.3 cm{sup 3} vs. 5.1 {+-} 3.6 cm{sup 3} (p 0.030) and mean RECIST size at 15 months of 4.34 {+-} 1.13 cm vs. 2.63 {+-} 0.84 cm (p =0.028) respectively for recurrence vs. RILI. At nine months post-SABR, patients with recurrence had significantly higher-density consolidative changes (mean at nine months of -96.4 {+-} 32.7 HU vs. -143.2 {+-} 28.4 HU for RILI; p =0.046). They also had increased variability of HU, an image texture metric, measured as the standard deviation (SD) of HU, in the GGO areas (SD at nine months of 210.6 {+-} 14.5 HU vs. 175.1 {+-} 18.7 HU for RILI; p =0.0078). Conclusions. Quantitative changes in mean HU and GGO textural analysis have the potential to distinguish RILI from recurrence as early as nine months post-SABR, compared to 15 months with RECIST and 3D volume. If validated, this approach could allow for earlier detection

  13. Measurement of the filtration coefficient (Kfc) in the lung of Gallus domesticus and the effects of increased microvascular permeability.

    Science.gov (United States)

    Weidner, W Jeffrey; Waddell, David S; Furlow, J David

    2006-08-01

    The filtration coefficient (Kfc) is a sensitive measure of microvascular hydraulic conductivity and has been reported for the alveolar lungs of many mammalian species, but not for the parabronchial avian lung. This study reports the Kfc in the isolated lungs of normal chickens and in the lungs of chickens given the edemogenic agents oleic acid (OA) or dimethyl amiloride (DMA). The control Kfc =0.04+/-0.01 ml min(-1) kPa(-1) g(-1). This parameter increased significantly following the administration of both OA (0.12+/-0.02 ml min(-1) kPa(-1) g(-1)) and DMA (0.07+/-0.01 ml min kPa(-1) g(-1)). As endothelial cadherins are thought to play a role in the dynamic response to acute lung injury, we utilized Western blot analysis to assess lung cadherin content and Northern blot analysis to assess pulmonary vascular endothelial (VE) cadherin expression following drug administration. Lung cadherin content decreases markedly following DMA, but not OA administration. VE cadherin expression increases as a result of DMA treatment, but is unchanged following OA. Our results suggest that the permeability characteristics of the avian lung are more closely consistent with those of the mammalian rather than the reptilian lung, and, that cadherins may play a significant role in the response to acute increases in avian pulmonary microvascular permeability.

  14. Measuring the Magnetic Flux Density in the CMS Steel Yoke

    CERN Document Server

    Klyukhin, V I; Ball, A; Curé, B; Gaddi, A; Gerwig, H; Hervé, A; Mulders, M; Loveless, R

    2012-01-01

    The Compact Muon Solenoid (CMS) is a general purpose detector, designed to run at the highest luminosity at the CERN Large Hadron Collider (LHC). Its distinctive features include a 4 T superconducting solenoid with 6-m-diameter by 12.5-m-length free bore, enclosed inside a 10000-ton return yoke made of construction steel. The return yoke consists of five dodecagonal three-layered barrel wheels and four end-cap disks at each end comprised of steel blocks up to 620 mm thick, which serve as the absorber plates of the muon detection system. Accurate characterization of the magnetic field everywhere in the CMS detector is required. To measure the field in and around the steel, a system of 22 flux-loops and 82 3-D Hall sensors is installed on the return yoke blocks. Fast discharges of the solenoid (190 s time-constant) made during the CMS magnet surface commissioning test at the solenoid central fields of 2.64, 3.16, 3.68 and 4.01 T were used to induce voltages in the flux-loops. The voltages are measured on-line a...

  15. Study on the technique for precision measurement of density of SiO_2 foam shells

    International Nuclear Information System (INIS)

    Ma Xiaojun; Gao Dangzhong; Meng Jie

    2013-01-01

    The measuring method based on vertical scanning interference and combined with the relation between refraction index and density of SiO_2 foam shells is introduced, and the relation is analyzed according to formulas of Lorentz-Lorenz and Gladstone-Dale. The experimental result and measuring uncertainty evaluation indicate that the precision measurement of density of low density SiO_2 foam shells can be realized by using the vertical scanning interference technique and combining with Gladstone and Dale analysis method, and the measuring uncertainty is about 5%. (authors)

  16. Large density amplification measured on jets ejected from a magnetized plasma gun

    OpenAIRE

    Yun, Gunsu S.; You, Setthivoine; Bellan, Paul M.

    2007-01-01

    Observation of a large density amplification in the collimating plasma jet ejected from a coplanar coaxial plasma gun is reported. The jet velocity is ~30 km s^-1 and the electron density increases from ~10^20 to 10^(22–23) m^-3. In previous spheromak experiments, electron density of the order 10^(19–21) m^-3 had been measured in the flux conserver region, but no density measurement had been reported for the source gun region. The coplanar geometry of our electrodes permits direct observation...

  17. Direct measurement of electron density in microdischarge at atmospheric pressure by Stark broadening

    International Nuclear Information System (INIS)

    Dong Lifang; Ran Junxia; Mao Zhiguo

    2005-01-01

    We present a method and results for measurement of electron density in atmospheric-pressure dielectric barrier discharge. The electron density of microdischarge in atmospheric pressure argon is measured by using the spectral line profile method. The asymmetrical deconvolution is used to obtain Stark broadening. The results show that the electron density in single filamentary microdischarge at atmospheric pressure argon is 3.05x10 15 cm -3 if the electron temperature is 10,000 K. The result is in good agreement with the simulation. The electron density in dielectric barrier discharge increases with the increase of applied voltage

  18. Absolute measurement of alkaline atoms in low density jet

    International Nuclear Information System (INIS)

    Labbe, J.; Guernigou, J.

    1974-01-01

    In order to determine the neutral fraction of cesium vapor which is not ionized in the beam issuing from an ion thruster, a particular sensor was developed at ONERA. This probe, the sensibility of which is 6 10 7 atoms sec -1 was used in order to measure the variation of cesium atom flux ejected from a spherical isothermal cavity. Experiments were performed in three flow conditions caracterized by the ratio of the mean free path to the dimension of the orifice or to the diameter of the cavity. Results demonstrate that it is possible in this configuration to obtain an efflux of 5 10 13 atoms sec -1 in accordance to cosine law when the mean free path is about the diameter of the spherical cavity [fr

  19. Plasma density fluctuation measurements from coherent and incoherent microwave reflection

    International Nuclear Information System (INIS)

    Conway, G.D.; Schott, L.; Hirose, A.

    1996-01-01

    Using the spatial coherency present in a reflected microwave signal (Conway et al 1994 Rev. Sci. Instrum. 65 2920) it is possible to measure a coherent, Γ c , and an incoherent, Γ i , reflection coefficient (proportional to the radar cross section) from a turbulent plasma cutoff layer. Results acquired with a 17 GHz reflectometer from a STOR-M tokamak edge region (r/a ∼ 0.8) give significant Γ c and Γ i , which suggests two-dimensional structure in the reflection layer. Using a 'distorted-mirror' model for the plasma fluctuations, estimates of an effective radial width, σ, and poloidal correlation length, L p , can be derived from the reflection coefficients. STOR-M results typically give a σ of a few millimetres and an L p of a couple of centimetres. (author)

  20. Modeling dendrite density from magnetic resonance diffusion measurements

    DEFF Research Database (Denmark)

    Jespersen, Sune Nørhøj; Kroenke, CD; Østergaard, Leif

    2007-01-01

    in this model: (i) the dendrites and axons, which are modeled as long cylinders with two diffusion coefficients, parallel (DL) and perpendicular (DT) to the cylindrical axis, and (ii) an isotropic monoexponential diffusion component describing water diffusion within and across all other structures, i.......e., in extracellular space and glia cells. The model parameters are estimated from 153 diffusion-weighted images acquired from a formalin-fixed baboon brain. A close correspondence between the data and the signal model is found, with the model parameters consistent with literature values. The model provides......Diffusion-weighted imaging (DWI) provides a noninvasive tool to probe tissue microstructure. We propose a simplified model of neural cytoarchitecture intended to capture the essential features important for water diffusion as measured by NMR. Two components contribute to the NMR signal...

  1. Blood Density Is Nearly Equal to Water Density: A Validation Study of the Gravimetric Method of Measuring Intraoperative Blood Loss.

    Science.gov (United States)

    Vitello, Dominic J; Ripper, Richard M; Fettiplace, Michael R; Weinberg, Guy L; Vitello, Joseph M

    2015-01-01

    Purpose. The gravimetric method of weighing surgical sponges is used to quantify intraoperative blood loss. The dry mass minus the wet mass of the gauze equals the volume of blood lost. This method assumes that the density of blood is equivalent to water (1 gm/mL). This study's purpose was to validate the assumption that the density of blood is equivalent to water and to correlate density with hematocrit. Methods. 50 µL of whole blood was weighed from eighteen rats. A distilled water control was weighed for each blood sample. The averages of the blood and water were compared utilizing a Student's unpaired, one-tailed t-test. The masses of the blood samples and the hematocrits were compared using a linear regression. Results. The average mass of the eighteen blood samples was 0.0489 g and that of the distilled water controls was 0.0492 g. The t-test showed P = 0.2269 and R (2) = 0.03154. The hematocrit values ranged from 24% to 48%. The linear regression R (2) value was 0.1767. Conclusions. The R (2) value comparing the blood and distilled water masses suggests high correlation between the two populations. Linear regression showed the hematocrit was not proportional to the mass of the blood. The study confirmed that the measured density of blood is similar to water.

  2. Radioisotope albumin flux measurement of microvascular lung permeability: an independent parameter in acute respiratory failure?

    International Nuclear Information System (INIS)

    Hoegerle, S.; Nitzsche, E.U.; Reinhardt, M.J.; Moser, E.; Benzing, A.; Geiger, K.; Schulte Moenting, J.

    2001-01-01

    Aim: To evaluate the extent to which single measurements of microvascular lung permeability may be relevant as an additional parameter in a heterogenous clinical patient collective with Acute Lung Injury (ALI) and Acute Respiratory Distress Syndrome (ARDS). Methods: In 36 patients with pneumonia (13), non pneumogenic sepsis (9) or trauma (14) meeting the consensus conference criteria of ALI or ARDS double-isotope protein flux measurements ( 51 Cr erythrocytes as intravascular tracer, Tc-99m human albumin as diffusible tracer) of microvascular lung permeability were performed using the Normalized Slope Index (NSI). The examination was to determine whether there is a relationship between the clinical diagnosis of ALI/ARDS, impaired permeability and clinical parameters, that is the underlying disease, oxygenation, duration of mechanical ventilation and mean pulmonary-artery pressure (PAP). Results: At the time of study, 25 patients presented with increased permeability (NSI > 1 x 10 -3 min -1 ) indicating an exudative stage of disease, and 11 patients with normal permeability. The permeability impairment correlated with the underlying disease (p > 0.05). With respect to survival, there was a negative correlation to PAP (p [de

  3. Comparison of neutral density profiles measured using Dα and C5+ in NSTX-U

    Science.gov (United States)

    Bell, R. E.; Scotti, F.; Diallo, A.; Leblanc, B. P.; Podesta, M.; Sabbagh, S. A.

    2017-10-01

    Edge neutral density profiles determined from two different measurements are compared on NSTX-U plasmas. Neutral density measurements were not typical on NSTX plasmas. An array of fibers dedicated to the measurement of passive emission of C5+, used to subtract background emission for charge exchange recombination spectroscopy (CHERS), can be used to infer deuterium neutral density near the plasma edge. The line emission from C5+ is dominated by charge exchange with neutral deuterium near the plasma edge. An edge neutral density diagnostic consisting of a camera with a Dα filter was installed on NSTX-U. The line-integrated measurements from both diagnostics are inverted to obtain local emissivity profiles. Neutral density is then inferred using atomics rates from ADAS and profile measurements from Thomson scattering and CHERS. Comparing neutral density profiles from the two diagnostic measurements helps determine the utility of using the more routinely available C5+ measurements for neutral density profiles. Initial comparisons show good agreement between the two measurements inside the separatrix. Supported by US DoE Contracts DE-AC02-09CH11466 and DE-AC52-07NA27344.

  4. Separate density and viscosity measurements of unknown liquid using quartz crystal microbalance

    Directory of Open Access Journals (Sweden)

    Feng Tan

    2016-09-01

    Full Text Available Aqueous liquids have a wide range of applications in many fields. Basic physical properties like the density and the viscosity have great impacts on the functionalities of a given ionic liquid. For the millions kinds of existing liquids, only a few have been systematically measured with the density and the viscosity using traditional methods. However, these methods are limited to measure the density and the viscosity of an ionic liquid simultaneously especially in processing micro sample volumes. To meet this challenge, we present a new theoretical model and a novel method to separate density and viscosity measurements with single quartz crystal microbalance (QCM in this work. The agreement of experimental results and theocratical calculations shows that the QCM is capable to measure the density and the viscosity of ionic liquids.

  5. An exposure system for measuring nasal and lung uptake of vapors in rats

    Energy Technology Data Exchange (ETDEWEB)

    Dahl, A.R.; Brookins, L.K.; Gerde, P. [National Inst. for Working Life, Solna (Sweden)

    1995-12-01

    Inhaled gases and vapors often produce biological damage in the nasal cavity and lower respiratory tract. The specific site within the respirator tract at which a gas or vapor is absorbed strongly influences the tissues at risk to potential toxic effects; to predict or to explain tissue or cell specific toxicity of inhaled gases or vapors, the sites at which they are absorbed must be known. The purpose of the work reported here was to develop a system for determining nose and lung absorption of vapors in rats, an animal commonly used in inhalation toxicity studies. In summary, the exposure system described allows us to measure in the rate: (1) nasal absorption and desorption of vapors; (2) net lung uptake of vapors; and (3) the effects of changed breathing parameters on vapor uptake.

  6. Application of interferometry and Faraday rotation techniques for density measurements on ITER

    International Nuclear Information System (INIS)

    Snider, R.T.; Carlstrom, T.N.; Ma, C.H.; Peebles, W.A.

    1995-01-01

    There is a need for real time, reliable density measurement for density control, compatible with the restricted access and radiation environment on ITER. Line average density measurements using microwave or laser interferometry techniques have proven to be robust and reliable for density control on contemporary tokamaks. In ITER, the large path length, high density and density gradients, limit the wavelength of a probing beam to shorter then about 50 microm due to refraction effects. In this paper the authors consider the design of short wavelength vibration compensated interferometers and Faraday rotation techniques for density measurements on ITER. These techniques allow operation of the diagnostics without a prohibitively large vibration isolated structure and permits the optics to be mounted directly on the radial port plugs on ITER. A beam path designed for 10.6 microm (CO2 laser) with a tangential path through the plasma allows both an interferometer and a Faraday rotation measurement of the line average density with good density resolution while avoiding refraction problems. Plasma effects on the probing beams and design tradeoffs will be discussed along with radiation and long pulse issues. A proposed layout of the diagnostic for ITER will be present

  7. Measurements of the sheath potential in low density plasmas

    International Nuclear Information System (INIS)

    Bradley, J.W.; Khamis, R.A.; Sanduk, M.I.; Elliott, J.A.; Rusbridge, M.G.

    1992-01-01

    We have measured the sheath potential around a probe in a range of different plasma conditions in the UMIST, University of Manchester Institute of Science and Technology, quadrupole GOLUX and in a related experiment in which the plasma expands freely to supersonic velocity. In the latter case, the sheath potential agrees well with an appropriately modified form of the usual expression for a field-free plasma, for both hydrogen and argon plasmas. In GOLUX, however, the sheath potential is found to be significantly less than the accepted value, even when the magnetic field is taken into account. For the slow moving plasma in the outer part of the quadrupole confining field, we present both theoretical and experimental results showing that the reduction is due to truncation of the electron velocity distribution as the probe drains electrons from a closed flux tube faster than they can be replaced. In the central hot plasma, however, this explanation cannot apply. Here, the plasma is moving at about sonic speed and magnetic effects are weak. Nevertheless, the results are significantly different from both in the field free experiment. (author)

  8. A high-throughput and sensitive method to measure Global DNA Methylation: Application in Lung Cancer

    Directory of Open Access Journals (Sweden)

    Mamaev Sergey

    2008-08-01

    Full Text Available Abstract Background Genome-wide changes in DNA methylation are an epigenetic phenomenon that can lead to the development of disease. The study of global DNA methylation utilizes technology that requires both expensive equipment and highly specialized skill sets. Methods We have designed and developed an assay, CpGlobal, which is easy-to-use, does not utilize PCR, radioactivity and expensive equipment. CpGlobal utilizes methyl-sensitive restriction enzymes, HRP Neutravidin to detect the biotinylated nucleotides incorporated in an end-fill reaction and a luminometer to measure the chemiluminescence. The assay shows high accuracy and reproducibility in measuring global DNA methylation. Furthermore, CpGlobal correlates significantly with High Performance Capillary Electrophoresis (HPCE, a gold standard technology. We have applied the technology to understand the role of global DNA methylation in the natural history of lung cancer. World-wide, it is the leading cause of death attributed to any cancer. The survival rate is 15% over 5 years due to the lack of any clinical symptoms until the disease has progressed to a stage where cure is limited. Results Through the use of cell lines and paired normal/tumor samples from patients with non-small cell lung cancer (NSCLC we show that global DNA hypomethylation is highly associated with the progression of the tumor. In addition, the results provide the first indication that the normal part of the lung from a cancer patient has already experienced a loss of methylation compared to a normal individual. Conclusion By detecting these changes in global DNA methylation, CpGlobal may have a role as a barometer for the onset and development of lung cancer.

  9. Density measurements in the boundary layer of the ASDEX RF heated plasma

    International Nuclear Information System (INIS)

    El Shaer, M.

    1986-11-01

    The boundary layer in the main chamber of ASDEX is diagnosed using a movable 2.2 mm microwave interferometer. The measured radial density profile decreases exponentially outside of the separatrix with three different e-folding lengths, the middle part of the profile is flatter with a larger e-folding length. The boundary density increases proportionally to the increase of the main plasmy density near the separatrix, far from the separatrix this increase is weaker. The boundary density increases with the increase of the main magnetic field in the discharge. With the application of the RF heating at the lower hybrid frequency the boundary density is submitted to a large modification. The behavior of this modification in the density profile depends on the rate of injection of the cold feeding gas. In the discharge with a constant or decreasing gas feeding rate the density profile flattens, and with an increasing rate it steepens when the RF pulse is applied. (orig.)

  10. Conservative surgery and radiotherapy for stage I/II breast cancer using lung density correction: 10-year and 15-year results

    International Nuclear Information System (INIS)

    Pierce, Lori J.; Griffith, Kent A.; Hayman, James A.; Douglas, Kathye R.; Lichter, Allen S.

    2005-01-01

    Purpose: Radiotherapy (RT) planning for breast cancer using lung density correction improves dose homogeneity. Its use obviates the need for a medial wedge, thus reducing scatter to the opposite breast. Although lung density correction is used at many centers in planning for early-stage breast cancer, long-term results of local control and survival have not been reported. Since 1984, we have used lung density correction for dose calculations at the University of Michigan. We now present our 10-year and 15-year results. Methods and Materials: The records of 867 patients with Stage I/II breast cancer treated with breast-conserving surgery and RT with or without systemic therapy were reviewed. Tangential fields delivering 45-50 Gy to the whole breast calculated using lung density correction were used. A boost was added in 96.8% of patients for a total median dose of 61.8 Gy. Results: With a median follow-up of 6.6 years (range, 0.2-18.9 years), 5-, 10-, and 15-year actuarial rates of in-breast tumor recurrence as only first failure were 2.2%, 3.6%, and 5.4%, respectively. With surgical salvage, the 15-year cumulative rate of local control was 99.7%. Factors that significantly predicted for increased rate of local recurrence in multivariate analysis were age ≤ 35 years, hazard ratio 4.8 (95% confidence interval [CI], 1.6-13.9) p = 0.004; negative progesterone receptor status, hazard ratio 6.8 (95% CI, 2.3-20.3) p = < 0.001; negative estrogen receptor status, hazard ratio 4.0 (95% CI, 1.5-11.1) p = 0.007; and lack of adjuvant tamoxifen therapy, hazard ratio 7.7 (95% CI, 1.7-33.3) p = 0.008. Relapse-free survival rates at 5, 10, and 15 years were 84.6%, 70.8%, and 55.9%, respectively; breast cancer-specific survival rates were 94.4%, 90.5%, and 86.9%, respectively; and corresponding estimates for overall survival were 89.7%, 75.7%, and 61.3%. Conclusions: Use of lung density correction was associated with high rates of local control, relapse-free survival, breast

  11. Study of errors in absolute flux density measurements of Cassiopeia A

    International Nuclear Information System (INIS)

    Kanda, M.

    1975-10-01

    An error analysis for absolute flux density measurements of Cassiopeia A is discussed. The lower-bound quadrature-accumulation error for state-of-the-art measurements of the absolute flux density of Cas A around 7 GHz is estimated to be 1.71% for 3 sigma limits. The corresponding practicable error for the careful but not state-of-the-art measurement is estimated to be 4.46% for 3 sigma limits

  12. Trapezium Bone Density-A Comparison of Measurements by DXA and CT.

    Science.gov (United States)

    Breddam Mosegaard, Sebastian; Breddam Mosegaard, Kamille; Bouteldja, Nadia; Bæk Hansen, Torben; Stilling, Maiken

    2018-01-18

    Bone density may influence the primary fixation of cementless implants, and poor bone density may increase the risk of implant failure. Before deciding on using total joint replacement as treatment in osteoarthritis of the trapeziometacarpal joint, it is valuable to determine the trapezium bone density. The aim of this study was to: (1) determine the correlation between measurements of bone mineral density of the trapezium obtained by dual-energy X-ray absorptiometry (DXA) scans by a circumference method and a new inner-ellipse method; and (2) to compare those to measurements of bone density obtained by computerized tomography (CT)-scans in Hounsfield units (HU). We included 71 hands from 59 patients with a mean age of 59 years (43-77). All patients had Eaton-Glickel stage II-IV trapeziometacarpal (TM) joint osteoarthritis, were under evaluation for trapeziometacarpal total joint replacement, and underwent DXA and CT wrist scans. There was an excellent correlation (r = 0.94) between DXA bone mineral density measures using the circumference and the inner-ellipse method. There was a moderate correlation between bone density measures obtained by DXA- and CT-scans with (r = 0.49) for the circumference method, and (r = 0.55) for the inner-ellipse method. DXA may be used in pre-operative evaluation of the trapezium bone quality, and the simpler DXA inner-ellipse measurement method can replace the DXA circumference method in estimation of bone density of the trapezium.

  13. Plasma density measurements on COMPASS-C tokamak from electron cyclotron emission cutoffs

    International Nuclear Information System (INIS)

    Chenna Reddy, D.; Edlington, T.

    1996-01-01

    Electron cyclotron emission (ECE) is a standard diagnostic in present day tokamak devices for temperature measurement. When the plasma density is high enough the emission at some frequencies is cut off. Of these cutoff frequencies, the first frequency to cut off depends on the shape of the density profile. If the density profile can be described by a few parameters, in some circumstances, this first cutoff frequency can be used to obtain two of these parameters. If more than two parameters are needed to describe the density profile, then additional independent measurements are required to find all the parameters. We describe a technique by which it is possible to obtain an analytical relation between the radius at which the first cutoff occurs and the profile parameters. Assuming that the shape of the profile does not change as the average density rises after the first cutoff, one can use the cutoffs at other frequencies to obtain the average density at the time of these cutoffs. The plasma densities obtained with this technique using the data from a 14 channel ECE diagnostic on COMPASS-C tokamak are in good agreement with those measured by a standard 2 mm interferometer. The density measurement using the ECE cutoffs is an independent measurement and requires only a frequency calibration of the ECE diagnostic. copyright 1996 American Institute of Physics

  14. Simulating measures of wood density through the surface by Compton scattering

    International Nuclear Information System (INIS)

    Penna, Rodrigo; Oliveira, Arno H.; Braga, Mario R.M.S.S.; Vasconcelos, Danilo C.; Carneiro, Clemente J.G.; Penna, Ariane G.C.

    2009-01-01

    Monte Carlo code (MCNP-4C) was used to simulate a nuclear densimeter for measuring wood densities nondestructively. An Americium source (E = 60 keV) and a NaI (Tl) detector were placed on a wood block surface. Results from MCNP shown that scattered photon fluxes may be used to determining wood densities. Linear regressions between scattered photons fluxes and wood density were calculated and shown correlation coefficients near unity. (author)

  15. High spatiotemporal resolution measurement of regional lung air volumes from 2D phase contrast x-ray images.

    Science.gov (United States)

    Leong, Andrew F T; Fouras, Andreas; Islam, M Sirajul; Wallace, Megan J; Hooper, Stuart B; Kitchen, Marcus J

    2013-04-01

    Described herein is a new technique for measuring regional lung air volumes from two-dimensional propagation-based phase contrast x-ray (PBI) images at very high spatial and temporal resolution. Phase contrast dramatically increases lung visibility and the outlined volumetric reconstruction technique quantifies dynamic changes in respiratory function. These methods can be used for assessing pulmonary disease and injury and for optimizing mechanical ventilation techniques for preterm infants using animal models. The volumetric reconstruction combines the algorithms of temporal subtraction and single image phase retrieval (SIPR) to isolate the image of the lungs from the thoracic cage in order to measure regional lung air volumes. The SIPR algorithm was used to recover the change in projected thickness of the lungs on a pixel-by-pixel basis (pixel dimensions ≈ 16.2 μm). The technique has been validated using numerical simulation and compared results of measuring regional lung air volumes with and without the use of temporal subtraction for removing the thoracic cage. To test this approach, a series of PBI images of newborn rabbit pups mechanically ventilated at different frequencies was employed. Regional lung air volumes measured from PBI images of newborn rabbit pups showed on average an improvement of at least 20% in 16% of pixels within the lungs in comparison to that measured without the use of temporal subtraction. The majority of pixels that showed an improvement was found to be in regions occupied by bone. Applying the volumetric technique to sequences of PBI images of newborn rabbit pups, it is shown that lung aeration at birth can be highly heterogeneous. This paper presents an image segmentation technique based on temporal subtraction that has successfully been used to isolate the lungs from PBI chest images, allowing the change in lung air volume to be measured over regions as small as the pixel size. Using this technique, it is possible to measure

  16. Comparison of subjective and fully automated methods for measuring mammographic density.

    Science.gov (United States)

    Moshina, Nataliia; Roman, Marta; Sebuødegård, Sofie; Waade, Gunvor G; Ursin, Giske; Hofvind, Solveig

    2018-02-01

    Background Breast radiologists of the Norwegian Breast Cancer Screening Program subjectively classified mammographic density using a three-point scale between 1996 and 2012 and changed into the fourth edition of the BI-RADS classification since 2013. In 2015, an automated volumetric breast density assessment software was installed at two screening units. Purpose To compare volumetric breast density measurements from the automated method with two subjective methods: the three-point scale and the BI-RADS density classification. Material and Methods Information on subjective and automated density assessment was obtained from screening examinations of 3635 women recalled for further assessment due to positive screening mammography between 2007 and 2015. The score of the three-point scale (I = fatty; II = medium dense; III = dense) was available for 2310 women. The BI-RADS density score was provided for 1325 women. Mean volumetric breast density was estimated for each category of the subjective classifications. The automated software assigned volumetric breast density to four categories. The agreement between BI-RADS and volumetric breast density categories was assessed using weighted kappa (k w ). Results Mean volumetric breast density was 4.5%, 7.5%, and 13.4% for categories I, II, and III of the three-point scale, respectively, and 4.4%, 7.5%, 9.9%, and 13.9% for the BI-RADS density categories, respectively ( P for trend density categories was k w  = 0.5 (95% CI = 0.47-0.53; P density increased with increasing density category of the subjective classifications. The agreement between BI-RADS and volumetric breast density categories was moderate.

  17. Plasma electron density measurement with multichannel microwave interferometer on the HL-1 tokamak device

    International Nuclear Information System (INIS)

    Xu Deming; Zhang Hongyin; Liu Zetian; Ding Xuantong; Li Qirui; Wen Yangxi

    1989-11-01

    A multichannel microwave interferometer which is composed of different microwave interferometers (one 2 mm band, one 4 mm band and two 8 mm band) has been used to measure the plasma electron density on HL-1 tokamak device. The electron density approaching to 5 x 10 13 cm -3 is measured by a 2 mm band microwave interferometer. In the determinable range, the electron density profile in the cross-section on HL-1 device has been measured by this interferometer. A microcomputer data processing system is also developed

  18. Measurements of low density, high velocity flow by electron beam fluorescence technique

    International Nuclear Information System (INIS)

    Soga, Takeo; Takanishi, Masaya; Yasuhara, Michiru

    1981-01-01

    A low density chamber with an electron gun system was made for the measurements of low density, high velocity (high Mach number) flow. This apparatus is a continuous running facility. The number density and the rotational temperature in the underexpanding free jet of nitrogen were measured along the axis of the jet by the electron beam fluorescence technique. The measurements were carried out from the vicinity of the exit of the jet to far downstream of the first Mach disk. Rotational nonequilibrium phenomena were observed in the hypersonic flow field as well as in the shock wave (Mach disk). (author)

  19. A method of atmospheric density measurements during Shuttle entry using UV laser Rayleigh scattering

    Science.gov (United States)

    Mckenzie, Robert L.

    1987-01-01

    A detailed study is described of the performance capabilities and the hardware requirements for a method in which ambient density is measured along the Space Shuttle flight path using on-board optical instrumentation. The technique relies on Rayleigh scattering of light from a pulsed, ultraviolet, ArF excimer laser operating at a wavelength of 193 nm. The method is shown to be capable of providing direct measurements of ambient density with an uncertainty of less than 1 percent and with a spatial resolution of 1 km, over an altitude range from 50 to 90 km. In addition, extensions of this concept are discussed that allow measurements of the shock wave location and the density profile within the shock layer. Two approaches are identified that appear to be feasible, in which the same laser system is used for the extended measurements as that required for the ambient density measurements.

  20. Measurements relating fire radiative energy density and surface fuel consumption - RxCADRE 2011 and 2012

    Science.gov (United States)

    Andrew T. Hudak; Matthew B. Dickinson; Benjamin C. Bright; Robert L. Kremens; E. Louise Loudermilk; Joseph J. O' Brien; Benjamin S. Hornsby; Roger D. Ottmar

    2016-01-01

    Small-scale experiments have demonstrated that fire radiative energy is linearly related to fuel combusted but such a relationship has not been shown at the landscape level of prescribed fires. This paper presents field and remotely sensed measures of pre-fire fuel loads, consumption, fire radiative energy density (FRED) and fire radiative power flux density (FRFD),...

  1. Reproducible automated breast density measure with no ionizing radiation using fat-water decomposition MRI.

    Science.gov (United States)

    Ding, Jie; Stopeck, Alison T; Gao, Yi; Marron, Marilyn T; Wertheim, Betsy C; Altbach, Maria I; Galons, Jean-Philippe; Roe, Denise J; Wang, Fang; Maskarinec, Gertraud; Thomson, Cynthia A; Thompson, Patricia A; Huang, Chuan

    2018-04-06

    Increased breast density is a significant independent risk factor for breast cancer, and recent studies show that this risk is modifiable. Hence, breast density measures sensitive to small changes are desired. Utilizing fat-water decomposition MRI, we propose an automated, reproducible breast density measurement, which is nonionizing and directly comparable to mammographic density (MD). Retrospective study. The study included two sample sets of breast cancer patients enrolled in a clinical trial, for concordance analysis with MD (40 patients) and reproducibility analysis (10 patients). The majority of MRI scans (59 scans) were performed with a 1.5T GE Signa scanner using radial IDEAL-GRASE sequence, while the remaining (seven scans) were performed with a 3T Siemens Skyra using 3D Cartesian 6-echo GRE sequence with a similar fat-water separation technique. After automated breast segmentation, breast density was calculated using FraGW, a new measure developed to reliably reflect the amount of fibroglandular tissue and total water content in the entire breast. Based on its concordance with MD, FraGW was calibrated to MR-based breast density (MRD) to be comparable to MD. A previous breast density measurement, Fra80-the ratio of breast voxels with density changes and treatment response. 3 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2018. © 2018 International Society for Magnetic Resonance in Medicine.

  2. Local electron density measurements in a screw pinch by means of a Michelson interferometer

    International Nuclear Information System (INIS)

    Hoekzema, J.A.; Busch, P.J.; Mastop, W.J.

    1976-06-01

    The time-dependent density profile of a toroidal screw-pinch plasma is determined from successive measurements of the line density along different sections of a line through the plasma. The pathlength is varied by the introduction of a hollow quartz tube into the plasma

  3. Microwave measurements of the time evolution of electron density in the T-11M tokamak

    International Nuclear Information System (INIS)

    Petrov, V.G.; Petrov, A.A.; Malyshev, A.Yu.; Markov, V.K.; Babarykin, A.V.

    2004-01-01

    Unambiguous diagnostics intended for measuring the time behavior of the electron density and monitoring the line-averaged plasma density in the T-11M tokamak are described. The time behavior of the plasma density in the T-11M tokamak is measured by a multichannel phase-jump-free microwave polarization interferometer based on the Cotton-Mouton effect. After increasing the number of simultaneously operating interferometer channels and enhancing the sensitivity of measurements, it became possible to measure the time evolution of the plasma density profile in the T-11M tokamak. The first results from such measurements in various operating regimes of the T-11M tokamak are presented. The measurement and data processing techniques are described, the measurement errors are analyzed, and the results obtained are discussed. We propose using a pulsed time-of-flight refractometer to monitor the average plasma density in the T-11M tokamak. The refractometer emits nanosecond microwave probing pulses with a carrier frequency that is higher than the plasma frequency and, thus, operates in the transmission mode. A version of the instrument has been developed with a carrier frequency of 140 GHz, which allows one to measure the average density in regimes with a nominal T-11M plasma density of (3-5) x 10 13 cm -3 . Results are presented from the first measurements of the average density in the T-11M tokamak with the help of a pulsed time-of-flight refractometer by probing the plasma in the equatorial plane in a regime with the reflection of the probing radiation from the inner wall of the vacuum chamber

  4. Real-time electron density measurements from Cotton-Mouton effect in JET machine

    International Nuclear Information System (INIS)

    Brombin, M.; Boboc, A.; Zabeo, L.; Murari, A.

    2008-01-01

    Real-time density profile measurements are essential for advanced fusion tokamak operation and interferometry is a proven method for this task. Nevertheless, as a consequence of edge localized modes, pellet injections, fast density increases, or disruptions, the interferometer is subject to fringe jumps, which produce loss of the signal preventing reliable use of the measured density in a real-time feedback controller. An alternative method to measure the density is polarimetry based on the Cotton-Mouton effect, which is proportional to the line-integrated electron density. A new analysis approach has been implemented and tested to verify the reliability of the Cotton-Mouton measurements for a wide range of plasma parameters and to compare the density evaluated from polarimetry with that from interferometry. The density measurements based on polarimetry are going to be integrated in the real-time control system of JET since the difference with the interferometry is within one fringe for more than 90% of the cases.

  5. Experimental study of a swept reflectometer with a single antenna for plasma density profile measurement

    International Nuclear Information System (INIS)

    Calderon, M.A.G.; Simonet, F.

    1984-12-01

    The feasibility of a swept microwave reflectometer, with one antenna only, for plasma electron density measurement is studied. Experimental results obtained in the laboratory by simulating the plasma with a metallic mirror are presented

  6. Porosity, Bulk Density, and Volume Reduction During Drying: Review of Measurement Methods and Coefficient Determinations

    NARCIS (Netherlands)

    Qiu, J.; Khalloufi, S.; Martynenko, A.; Dalen, van G.; Schutyser, M.A.I.; Almeida-Rivera, C.

    2015-01-01

    Several experimental methods for measuring porosity, bulk density and volume reduction during drying of foodstuff are available. These methods include among others geometric dimension, volume displacement, mercury porosimeter, micro-CT, and NMR. However, data on their accuracy, sensitivity, and

  7. Stantardization problems in radioisotopic techniques for measuring rock density and humidity

    International Nuclear Information System (INIS)

    Golubin, O.V.; Pavlov, L.S.

    1977-01-01

    A description of the main technical characteristics is given of radioisotope densimeters and hydrometers taken as a base for the State Standard design for field radioisotope instruments for measuring density and moisture of the soil and rocks

  8. Modal decomposition for measuring the orbital angular momentum density of light

    CSIR Research Space (South Africa)

    Schulze, C

    2013-02-01

    Full Text Available We present a novel technique to measure the orbital angular momentum (OAM) density of light. The technique is based on modal decomposition, enabling the complete reconstruction of optical fields, including the reconstruction of the beams Poynting...

  9. Experimental measurements and prediction of liquid densities for n-alkane mixtures

    International Nuclear Information System (INIS)

    Ramos-Estrada, Mariana; Iglesias-Silva, Gustavo A.; Hall, Kenneth R.

    2006-01-01

    We present experimental liquid densities for n-pentane, n-hexane and n-heptane and their binary mixtures from (273.15 to 363.15) K over the entire composition range (for the mixtures) at atmospheric pressure. A vibrating tube densimeter produces the experimental densities. Also, we present a generalized correlation to predict the liquid densities of n-alkanes and their mixtures. We have combined the principle of congruence with the Tait equation to obtain an equation that uses as variables: temperature, pressure and the equivalent carbon number of the mixture. Also, we present a generalized correlation for the atmospheric liquid densities of n-alkanes. The average absolute percentage deviation of this equation from the literature experimental density values is 0.26%. The Tait equation has an average percentage deviation of 0.15% from experimental density measurements

  10. Obtaining sub-daily new snow density from automated measurements in high mountain regions

    Science.gov (United States)

    Helfricht, Kay; Hartl, Lea; Koch, Roland; Marty, Christoph; Olefs, Marc

    2018-05-01

    The density of new snow is operationally monitored by meteorological or hydrological services at daily time intervals, or occasionally measured in local field studies. However, meteorological conditions and thus settling of the freshly deposited snow rapidly alter the new snow density until measurement. Physically based snow models and nowcasting applications make use of hourly weather data to determine the water equivalent of the snowfall and snow depth. In previous studies, a number of empirical parameterizations were developed to approximate the new snow density by meteorological parameters. These parameterizations are largely based on new snow measurements derived from local in situ measurements. In this study a data set of automated snow measurements at four stations located in the European Alps is analysed for several winter seasons. Hourly new snow densities are calculated from the height of new snow and the water equivalent of snowfall. Considering the settling of the new snow and the old snowpack, the average hourly new snow density is 68 kg m-3, with a standard deviation of 9 kg m-3. Seven existing parameterizations for estimating new snow densities were tested against these data, and most calculations overestimate the hourly automated measurements. Two of the tested parameterizations were capable of simulating low new snow densities observed at sheltered inner-alpine stations. The observed variability in new snow density from the automated measurements could not be described with satisfactory statistical significance by any of the investigated parameterizations. Applying simple linear regressions between new snow density and wet bulb temperature based on the measurements' data resulted in significant relationships (r2 > 0.5 and p ≤ 0.05) for single periods at individual stations only. Higher new snow density was calculated for the highest elevated and most wind-exposed station location. Whereas snow measurements using ultrasonic devices and snow

  11. Measurement of hard tissue density of head phantom based on the HU by using CBCT

    International Nuclear Information System (INIS)

    Kim, Moon Sun; Kang, Dong Wan; Kim, Jae Duk

    2009-01-01

    The purpose of this study was to determine a conversion coefficient for Hounsfield Units(HU) to material density (g cm -3 ) obtained from cone-beam computed tomography (CBMercuRay TM ) data and to measure the hard tissue density based on the Hounsfield scale on dental head phantom. CT Scanner Phantom (AAPM) equipped with CT Number Insert consists of five cylindrical pins of materials with different densities and teflon ring was scanned by using the CBMercuRay TM (Hitachi, Tokyo, Japan) volume scanner. The raw data were converted into DICOM format and the HU of different areas of CT number insert measured by using CBWorks TM . Linear regression analysis and Student t-test were performed statistically. There was no significant difference (P>0.54) between real densities and measured densities. A linear regression was performed using the density, ρ (g cm -3 ), as the dependent variable in terms of the HU (H). The regression equation obtained was ρ=0.00072 H-0.01588 with an R2 value of 0.9968. Density values based on the Hounsfield scale was 1697.1 ± 24.9 HU in cortical bone, 526.5 ± 44.4 HU in trabecular bone, 2639.1 ± 48.7 HU in enamel, 1246.1 ± 39.4 HU in dentin of dental head phantom. CBCT provides an effective option for determination of material density expressed as Hounsfield Units.

  12. Spectroscopic measurements of the density and electronic temperature at the plasma edge in Tore Supra

    International Nuclear Information System (INIS)

    Lediankine, A.

    1996-01-01

    The profiles of temperature and electronic density at the plasma edge are important to study the wall-plasma interaction and the radiative layers in the Tokamak plasmas. The laser ablation technique of the lithium allows to measure the profile of electronic density. To measure the profile of temperature, it has been used for the first time, the injection of a fluorine neutral atoms beam. The experiments, the results are described in this work. (N.C.)

  13. Method of measuring the current density distribution and emittance of pulsed electron beams

    International Nuclear Information System (INIS)

    Schilling, H.B.

    1979-07-01

    This method of current density measurement employs an array of many Faraday cups, each cup being terminated by an integrating capacitor. The voltages of the capacitors are subsequently displayed on a scope, thus giving the complete current density distribution with one shot. In the case of emittance measurements, a moveable small-diameter aperture is inserted at some distance in front of the cup array. Typical results with a two-cathode, two-energy electron source are presented. (orig.)

  14. System for uranium superficial density measurement in U3Si2 MTR fuel plates using radiography

    International Nuclear Information System (INIS)

    Hey, Martin A.; Gomez Marlasca, Fernando

    2003-01-01

    The paper describes a method for measuring uranium superficial density in high density uranium silicide (U 3 Si 2 ) MTR fuel plates, through the use of industrial radiography, a set of patterns built for this purpose, a transmission optical densitometer, and a quantitative model of analysis and measurement. Our choice for this particular method responds to its high accuracy, low cost and easy implementation according to the standing quality control systems. (author)

  15. Measurement of the absolute tunneling current density in field emission from tungsten(110)

    International Nuclear Information System (INIS)

    Ehrlich, C.D.; Plummer, E.W.

    1978-01-01

    The phenomenon of quantum-mechanical tunneling of an electron through a barrier in the potential energy has been well established in a variety of experiments. The quantity which is usually measured in these experiments is the rate of change of tunneling current and not the absolute current density. This paper reports on a direct measurement of the tunneling current density, which is found to be in good agreement with free-electron theory for W

  16. Comparison of measured and modelled negative hydrogen ion densities at the ECR-discharge HOMER

    Science.gov (United States)

    Rauner, D.; Kurutz, U.; Fantz, U.

    2015-04-01

    As the negative hydrogen ion density nH- is a key parameter for the investigation of negative ion sources, its diagnostic quantification is essential in source development and operation as well as for fundamental research. By utilizing the photodetachment process of negative ions, generally two different diagnostic methods can be applied: via laser photodetachment, the density of negative ions is measured locally, but only relatively to the electron density. To obtain absolute densities, the electron density has to be measured additionally, which induces further uncertainties. Via cavity ring-down spectroscopy (CRDS), the absolute density of H- is measured directly, however LOS-averaged over the plasma length. At the ECR-discharge HOMER, where H- is produced in the plasma volume, laser photodetachment is applied as the standard method to measure nH-. The additional application of CRDS provides the possibility to directly obtain absolute values of nH-, thereby successfully bench-marking the laser photodetachment system as both diagnostics are in good agreement. In the investigated pressure range from 0.3 to 3 Pa, the measured negative hydrogen ion density shows a maximum at 1 to 1.5 Pa and an approximately linear response to increasing input microwave powers from 200 up to 500 W. Additionally, the volume production of negative ions is 0-dimensionally modelled by balancing H- production and destruction processes. The modelled densities are adapted to the absolute measurements of nH- via CRDS, allowing to identify collisions of H- with hydrogen atoms (associative and non-associative detachment) to be the dominant loss process of H- in the plasma volume at HOMER. Furthermore, the characteristic peak of nH- observed at 1 to 1.5 Pa is identified to be caused by a comparable behaviour of the electron density with varying pressure, as ne determines the volume production rate via dissociative electron attachment to vibrationally excited hydrogen molecules.

  17. Changes in CT density-measurement of intraorbital wooden foreign bodies

    International Nuclear Information System (INIS)

    Otani, Etsuko; Hiyama, Fusako; Machi, Setsuko; Hagihara, Masahiro.

    1991-01-01

    We examined in vitro changes in CT density-measurement of intraorbital wooden foreign bodies. Dry wooden sticks were immersed in distilled water, saline, and serum. Computerized tomography scans were taken several times during 22 weeks. Scans were taken in room air and in fatty tissue. The CT density-measurement of the central part of the wooden bodies was calculated. That of the dry wood was about 500 HU; all of the wooden foreign bodies became denser during the 22 weeks, with those immersed in distilled water and saline at about 130 HU, and those immersed in serum at about 150 HU. It was confirmed that wood becomes denser after soaking in aqueous environments. The CT density of wood soaked in water depends on the density of wood fiber, and the CT density of the wood fiber itself. (author)

  18. X-ray radiographic technique for measuring density uniformity of silica aerogel

    International Nuclear Information System (INIS)

    Tabata, Makoto; Hatakeyama, Yoshikiyo; Adachi, Ichiro; Morita, Takeshi; Nishikawa, Keiko

    2013-01-01

    This paper proposes a new X-ray radiographic technique for measuring density uniformity of silica aerogels used as radiator in proximity-focusing ring-imaging Cherenkov detectors. To obtain high performance in a large-area detector, a key characteristic of radiator is the density (i.e. refractive index) uniformity of an individual aerogel monolith. At a refractive index of n=1.05, our requirement for the refractive index uniformity in the transverse plane direction of an aerogel tile is |δ(n−1)/(n−1)|<4% in a focusing dual layer radiator (with different refractive indices) scheme. We applied the radiographic technique to evaluate the density uniformity of our original aerogels from a trial production and that of Panasonic products (SP-50) as a reference, and to confirm they have sufficient density uniformity within ±1% along the transverse plane direction. The measurement results show that the proposed technique can quantitatively estimate the density uniformity of aerogels.

  19. Measuring the Plasma Density of a Ferroelectric Plasma Source in an Expanding Plasma

    International Nuclear Information System (INIS)

    Dunaevsky, A.; Fisch, N.J.

    2003-01-01

    The initial density and electron temperature at the surface of a ferroelectric plasma source were deduced from floating probe measurements in an expanding plasma. The method exploits negative charging of the floating probe capacitance by fast flows before the expanding plasma reaches the probe. The temporal profiles of the plasma density can be obtained from the voltage traces of the discharge of the charged probe capacitance by the ion current from the expanding plasma. The temporal profiles of the plasma density, at two different distances from the surface of the ferroelectric plasma source, could be further fitted by using the density profiles for the expanding plasma. This gives the initial values of the plasma density and electron temperature at the surface. The method could be useful for any pulsed discharge, which is accompanied by considerable electromagnetic noise, if the initial plasma parameters might be deduced from measurements in expanding plasma

  20. Electron temperature and density profiles measurement in the TJ-1 tokamak by Thomson scattering

    International Nuclear Information System (INIS)

    Pardo, C.; Zurro, B.

    1986-01-01

    Electron temperature and density profiles of ohmically heated hydrogen plasmas in the TJ-1 tokamak have been measured by Thomson scattering. The temperature profile peaks sharply in the central region while the density profile is very flat. Temperature values between 100 and 390 eV have been measured for densities in the range of 5.10 12 to 2.6.10 13 cm -3 . Parameters characterizing TJ-1 plasma, such as confinement times Z eff , have been deduced from experimental data. Energy confinement times are compared with experimental scaling laws. (author)

  1. CO2 laser interferometer for temporally and spatially resolved electron density measurements

    Science.gov (United States)

    Brannon, P. J.; Gerber, R. A.; Gerardo, J. B.

    1982-09-01

    A 10.6-μm Mach-Zehnder interferometer has been constructed to make temporally and spatially resolved measurements of electron densities in plasmas. The device uses a pyroelectric vidicon camera and video memory to record and display the two-dimensional fringe pattern and a Pockels cell to limit the pulse width of the 10.6-μm radiation. A temporal resolution of 14 ns has been demonstrated. The relative sensitivity of the device for electron density measurements is 2×1015 cm-2 (the line integral of the line-of-sight length and electron density), which corresponds to 0.1 fringe shift.

  2. CO2 laser interferometer for temporally and spatially resolved electron density measurements

    International Nuclear Information System (INIS)

    Brannon, P.J.; Gerber, R.A.; Gerardo, J.B.

    1982-01-01

    A 10.6-μm Mach--Zehnder interferometer has been constructed to make temporally and spatially resolved measurements of electron densities in plasmas. The device uses a pyroelectric vidicon camera and video memory to record and display the two-dimensional fringe pattern and a Pockels cell to limit the pulse width of the 10.6-μm radiation. A temporal resolution of 14 ns has been demonstrated. The relative sensitivity of the device for electron density measurements is 2 x 10 15 cm -2 (the line integral of the line-of-sight length and electron density), which corresponds to 0.1 fringe shift

  3. Measurement of log moisture content and density by gamma and neutron backscatter

    International Nuclear Information System (INIS)

    Barry, B.J.

    2002-01-01

    Measurement of the moisture content and green density of wood was investigated using scattering of gamma rays and neutrons. Both of these processes are dependent on density but neutrons are particularly sensitive to the hydrogen content, which changes with moisture content. A material mimicking the green density and moisture content of real wood was successfully used in a laboratory study to establish the feasibility of measuring these within the range found in standing trees. A later field trial indicated that the technique needed more development to take account of the natural variability of real trees. (author). 3 refs., 11 figs., 1 table

  4. Density measurement by means of once scattered gamma radiation the ETG probe, principles and equipment

    International Nuclear Information System (INIS)

    Joergensen, J.L.; Oelgaard, P.L.; Berg, F.

    1987-01-01

    The Department of Electrophysics, the Technical University of Denmark, and the Danish National Road Laboratory have together developed a new patent claimed device for measurements of the in situ density of materials. This report describes the principles of the system and some experimental results. The system is based on the once scattered gamma radiation. In a totally non-destructive and fast way it is possible to measure the density of up to 25 cm thick layers. Furthermore, an estimate of the density variation through the layer may be obtained. Thus the gauge represents a new generation of equipment for e.g. compaction control of road constructions. (author)

  5. Radioisotope labeling technique for vapor density measurements of volatile inorganic species

    International Nuclear Information System (INIS)

    Peterson, E.J.; Caird, J.A.; Hessler, J.P.; Hoekstra, H.R.; Williams, C.W.

    1979-01-01

    A new method for complexed metal ion vapor density measurement involving labeling the metal ions of interest with a radioactive isotope is described. The isotope chosen in the present work is unstable and leads to emission of a characteristic γ ray. Thus the γ-counting rate was related to the number density of complexed metal ions in the vapor phase. This technique is applicable to the study of any volatile inorganic species, but in the present study has been used to measure vapor densities of complex species in the TbCl 3 -AlCl 3 system by using tracer 160 Tb. 4 figures, 2 tables

  6. The association between anthropometric measures and lung function in a population-based study of Canadian adults.

    Science.gov (United States)

    Rowe, A; Hernandez, P; Kuhle, S; Kirkland, S

    2017-10-01

    Decreased lung function has health impacts beyond diagnosable lung disease. It is therefore important to understand the factors that may influence even small changes in lung function including obesity, physical fitness and physical activity. The aim of this study was to determine the anthropometric measure most useful in examining the association with lung function and to determine how physical activity and physical fitness influence this association. The current study used cross-sectional data on 4662 adults aged 40-79 years from the Canadian Health Measures Survey Cycles 1 and 2. Linear regression models were used to examine the association between the anthropometric and lung function measures (forced expiratory volume in 1 s [FEV 1 ] and forced vital capacity [FVC]); R 2 values were compared among models. Physical fitness and physical activity terms were added to the models and potential confounding was assessed. Models using sum of 5 skinfolds and waist circumference consistently had the highest R 2 values for FEV 1 and FVC, while models using body mass index consistently had among the lowest R 2 values for FEV 1 and FVC and for men and women. Physical activity and physical fitness were confounders of the relationships between waist circumference and the lung function measures. Waist circumference remained a significant predictor of FVC but not FEV 1 after adjustment for physical activity or physical fitness. Waist circumference is an important predictor of lung function. Physical activity and physical fitness should be considered as potential confounders of the relationship between anthropometric measures and lung function. Copyright © 2017. Published by Elsevier Ltd.

  7. Role of perfusion SPECT in prediction and measurement of pulmonary complications after radiotherapy for lung cancer

    Energy Technology Data Exchange (ETDEWEB)

    Farr, Katherina P.; Khalil, Azza A.; Grau, Cai [Aarhus University Hospital, Department of Oncology, Aarhus C (Denmark); Kramer, Stine; Morsing, Anni [Aarhus University Hospital, Department of Nuclear Medicine and PET Centre, Aarhus C (Denmark)

    2015-07-15

    The purpose of the study was to evaluate the ability of baseline perfusion defect score (DS) on SPECT to predict the development of severe symptomatic radiation pneumonitis (RP) and to evaluate changes in perfusion on SPECT as a method of lung perfusion function assessment after curative radiotherapy (RT) for non-small-cell lung cancer (NSCLC). Patients with NSCLC undergoing curative RT were included prospectively. Perfusion SPECT/CT and global pulmonary function tests (PFT) were performed before RT and four times during follow-up. Functional activity on SPECT was measured using a semiquantitative perfusion DS. Pulmonary morbidity was graded by the National Cancer Institute's Common Terminology Criteria for Adverse Events version 4 for pneumonitis. Patients were divided into two groups according to the severity of RP. A total of 71 consecutive patients were included in the study. Baseline DS was associated with chronic obstructive pulmonary disease. A significant inverse correlation was found between baseline DS and forced expiratory volume in 1 s and diffusing capacity of the lung for carbon monoxide. Patients with severe RP had significantly higher baseline total lung DS (mean 5.43) than those with no or mild symptoms (mean DS 3.96, p < 0.01). PFT results were not different between these two groups. The odds ratio for total lung DS was 7.8 (95 % CI 1.9 - 31) demonstrating the ability of this parameter to predict severe RP. Adjustment for other potential confounders known to be associated with increased risk of RP was performed and did not change the odds ratio. The median follow-up time after RT was 8.4 months. The largest DS increase of 13.3 % was associated with severe RP at 3 months of follow-up (p < 0.01). The development of severe RP during follow-up was not associated with changes in PFT results. Perfusion SPECT is a valuable method for predicting severe RP and for assessing changes in regional functional perfusion after curative RT comparable with

  8. A lung cancer risk classifier comprising genome maintenance genes measured in normal bronchial epithelial cells.

    Science.gov (United States)

    Yeo, Jiyoun; Crawford, Erin L; Zhang, Xiaolu; Khuder, Sadik; Chen, Tian; Levin, Albert; Blomquist, Thomas M; Willey, James C

    2017-05-02

    Annual low dose CT (LDCT) screening of individuals at high demographic risk reduces lung cancer mortality by more than 20%. However, subjects selected for screening based on demographic criteria typically have less than a 10% lifetime risk for lung cancer. Thus, there is need for a biomarker that better stratifies subjects for LDCT screening. Toward this goal, we previously reported a lung cancer risk test (LCRT) biomarker comprising 14 genome-maintenance (GM) pathway genes measured in normal bronchial epithelial cells (NBEC) that accurately classified cancer (CA) from non-cancer (NC) subjects. The primary goal of the studies reported here was to optimize the LCRT biomarker for high specificity and ease of clinical implementation. Targeted competitive multiplex PCR amplicon libraries were prepared for next generation sequencing (NGS) analysis of transcript abundance at 68 sites among 33 GM target genes in NBEC specimens collected from a retrospective cohort of 120 subjects, including 61 CA cases and 59 NC controls. Genes were selected for analysis based on contribution to the previously reported LCRT biomarker and/or prior evidence for association with lung cancer risk. Linear discriminant analysis was used to identify the most accurate classifier suitable to stratify subjects for screening. After cross-validation, a model comprising expression values from 12 genes (CDKN1A, E2F1, ERCC1, ERCC4, ERCC5, GPX1, GSTP1, KEAP1, RB1, TP53, TP63, and XRCC1) and demographic factors age, gender, and pack-years smoking, had Receiver Operator Characteristic area under the curve (ROC AUC) of 0.975 (95% CI: 0.96-0.99). The overall classification accuracy was 93% (95% CI 88%-98%) with sensitivity 93.1%, specificity 92.9%, positive predictive value 93.1% and negative predictive value 93%. The ROC AUC for this classifier was significantly better (p < 0.0001) than the best model comprising demographic features alone. The LCRT biomarker reported here displayed high accuracy and ease

  9. New bioreactor for in situ simultaneous measurement of bioluminescence and cell density

    Science.gov (United States)

    Picart, Pascal; Bendriaa, Loubna; Daniel, Philippe; Horry, Habib; Durand, Marie-José; Jouvanneau, Laurent; Thouand, Gérald

    2004-03-01

    This article presents a new device devoted to the simultaneous measurement of bioluminescence and optical density of a bioluminescent bacterial culture. It features an optoelectronic bioreactor with a fully autoclavable module, in which the bioluminescent bacteria are cultivated, a modulated laser diode dedicated to optical density measurement, and a detection head for the acquisition of both bioluminescence and optical density signals. Light is detected through a bifurcated fiber bundle. This setup allows the simultaneous estimation of the bioluminescence and the cell density of the culture medium without any sampling. The bioluminescence is measured through a highly sensitive photomultiplier unit which has been photometrically calibrated to allow light flux measurements. This was achieved by considering the bioluminescence spectrum and the full optical transmission of the device. The instrument makes it possible to measure a very weak light flux of only a few pW. The optical density is determined through the laser diode and a photodiode using numerical synchronous detection which is based on the power spectrum density of the recorded signal. The detection was calibrated to measure optical density up to 2.5. The device was validated using the Vibrio fischeri bacterium which was cultivated under continuous culture conditions. A very good correlation between manual and automatic measurements processed with this instrument has been demonstrated. Furthermore, the optoelectronic bioreactor enables determination of the luminance of the bioluminescent bacteria which is estimated to be 6×10-5 W sr-1 m-2 for optical density=0.3. Experimental results are presented and discussed.

  10. Sagittal-lung CT measurements in the evaluation of asthma-COPD overlap syndrome: a distinctive phenotype from COPD alone.

    Science.gov (United States)

    Qu, Yanjuan; Cao, Yiyuan; Liao, Meiyan; Lu, Zhiyan

    2017-07-01

    This study aimed at investigating the capability of sagittal-lung computed tomography (CT) measurements in differentiating chronic obstructive pulmonary disease (COPD) and asthma-COPD overlap syndrome (ACOS). Clinical and high-resolution CT of 229 patients including 123 pure COPD patients and 106 ACOS patients were included. Sagittal-lung CT measurements in terms of bilateral lung height (LH), anterior-posterior lung diameter (APLD), diaphragm height (DH), and anterior sterno-diaphragmatic angle (ASDA), as well as inter-pulmonary septum length (IPSL) on axial images were measured both before and after bronchodilator (BD) administration. Comparisons of clinical characteristics and CT measurements between patient groups were performed. All pre-BD quantitative sagittal features measuring diaphragm flattening and hyperinflation were not significantly different between patients with COPD and patients with ACOS (P values all >0.05). Following BD administration, the ACOS patients exhibited lower left LH, bilateral APLD, and bilateral ASDA, but higher right DH, compared to pure COPD patients (P values all <0.05). Right LH, left DH and IPSL were not significantly different between patient groups. Besides, variations of all sagittal-lung CT measurements were significantly larger in patients with ACOS than in patients with pure COPD (P values all <0.001) and showed high performance in differentiating these two kinds of patient, with diagnostic sensitivities ranging from 76.4 to 97.2%, specificities ranging from 86.2 to 100.0%, and accuracies ranging from 80.9 to 90.7%. Sagittal-lung CT measurements allow for differentiating patients with ACOS from those with pure COPD. The ACOS patients had larger post-BD variations of sagittal-lung CT measurements than patients with pure COPD.

  11. Spatially resolved density and ionization measurements of shocked foams using x-ray fluorescence

    Energy Technology Data Exchange (ETDEWEB)

    MacDonald, M. J.; Keiter, P. A.; Montgomery, D. S.; Scott, H. A.; Biener, M. M.; Fein, J. R.; Fournier, K. B.; Gamboa, E. J.; Kemp, G. E.; Klein, S. R.; Kuranz, C. C.; LeFevre, H. J.; Manuel, M. J. -E.; Wan, W. C.; Drake, R. P.

    2016-09-28

    We present experiments at the Trident laser facility demonstrating the use of x-ray fluorescence (XRF) to simultaneously measure density, ionization state populations, and electron temperature in shocked foams. An imaging x-ray spectrometer obtained spatially resolved measurements of Ti K-α emission. Density profiles were measured from K-α intensity. Ti ionization state distributions and electron temperatures were inferred by fitting K-α spectra to spectra from CRETIN simulations. This work shows that XRF provides a powerful tool to complement other diagnostics to make equation of state measurements of shocked materials containing a suitable tracer element.

  12. Summer sudden Na number density enhancements measured with the ALOMAR Weber Na Lidar

    Directory of Open Access Journals (Sweden)

    D. Heinrich

    2008-05-01

    Full Text Available We present summer Na-densities and atmospheric temperatures measured 80 to 110 km above the Arctic Lidar Observatory for Middle Atmosphere Research (ALOMAR. The Weber Na Lidar is part of ALOMAR, located at 69° N in Norway, 150 km north of the Arctic Circle. The sun does not set here during the summer months, and measurements require a narrowband Faraday Anomalous Dispersion Optical Filter (FADOF.

    We discuss an observed sudden enhancement in the Na number density around 22:00 UT on 1 to 2 June 2006. We compare this observation with previous summer measurements and find a frequent appearance of Na number density enhancements near local midnight. We describe the time of appearance, the altitude distribution, the duration and the strength of these enhancements and compare them to winter observations. We investigate possible formation mechanisms and, as others before, we find a strong link between these Na number density enhancements and sporadic E layers.

  13. Summer sudden Na number density enhancements measured with the ALOMAR Weber Na Lidar

    Directory of Open Access Journals (Sweden)

    D. Heinrich

    2008-05-01

    Full Text Available We present summer Na-densities and atmospheric temperatures measured 80 to 110 km above the Arctic Lidar Observatory for Middle Atmosphere Research (ALOMAR. The Weber Na Lidar is part of ALOMAR, located at 69° N in Norway, 150 km north of the Arctic Circle. The sun does not set here during the summer months, and measurements require a narrowband Faraday Anomalous Dispersion Optical Filter (FADOF. We discuss an observed sudden enhancement in the Na number density around 22:00 UT on 1 to 2 June 2006. We compare this observation with previous summer measurements and find a frequent appearance of Na number density enhancements near local midnight. We describe the time of appearance, the altitude distribution, the duration and the strength of these enhancements and compare them to winter observations. We investigate possible formation mechanisms and, as others before, we find a strong link between these Na number density enhancements and sporadic E layers.

  14. Observer variability of lung function measurements in 2-6-yr-old children

    DEFF Research Database (Denmark)

    Klug, B; Nielsen, K G; Bisgaard, H

    2000-01-01

    by the interrupter technique measurements in young children are subject to influence by the observer, and the random variability between observers appears to be particularly great for respiratory resistance assessed by the interrupter technique. The authors suggest that the between-observer variability should......The aim of this study was to assess the within-observer and between-observer variability of lung function measurements in children aged 2-6 yrs. Two observers examined 22 asthmatic children independently according to a predefined protocol. Each observer obtained duplicate measurements...... observers. The ratio SDw between observers/mean SDw within observers was 0.94, 1.25, 1.35 and 2.86 for Xrs,5, Rrs,5, sRaw and Rint, respectively, indicating greater between-observer variability of the latter. The systematic difference between observers assessed by the difference between observer means...

  15. Quantitative measurements of localized density variations in cylindrical tablets using X-ray microtomography.

    Science.gov (United States)

    Busignies, Virginie; Leclerc, Bernard; Porion, Patrice; Evesque, Pierre; Couarraze, Guy; Tchoreloff, Pierre

    2006-08-01

    Direct compaction is a complex process that results in a density distribution inside the tablets which is often heterogeneous. Therefore, the density variations may affect the compact properties. A quantitative analysis of this phenomenon is still lacking. Recently, X-ray microtomography has been successfully used in pharmaceutical development to study qualitatively the impact of tablet shape and break-line in the density of pharmaceutical tablets. In this study, we evaluate the density profile in microcrystalline cellulose (Vivapur 12) compacts obtained at different mean porosity (ranging from 7.7% to 33.5%) using X-ray tomography technique. First, the validity of the Beer-Lambert law is studied. Then, density calibration is performed and density maps of cylindrical tablets are obtained and visualized using a process with colour-scale calibration plot which is explained. As expected, important heterogeneity in density is observed and quantified. The higher densities in peripheral region were particularly investigated and appraised in regard to the lower densities observed in the middle of the tablet. The results also underlined that in the case of pharmaceutical tablets, it is important to differentiate the mechanical properties representative of the total volume tablet and the mechanical properties that only characterize the tablet surface like the Brinell hardness measurements.

  16. The prediction of cyclic proximal humerus fracture fixation failure by various bone density measures.

    Science.gov (United States)

    Varga, Peter; Grünwald, Leonard; Windolf, Markus

    2018-02-22

    Fixation of osteoporotic proximal humerus fractures has remained challenging, but may be improved by careful pre-operative planning. The aim of this study was to investigate how well the failure of locking plate fixation of osteoporotic proximal humerus fractures can be predicted by bone density measures assessed with currently available clinical imaging (realistic case) and a higher resolution and quality modality (theoretical best-case). Various density measures were correlated to experimentally assessed number of cycles to construct failure of plated unstable low-density proximal humerus fractures (N = 18). The influence of density evaluation technique was investigated by comparing local (peri-implant) versus global evaluation regions; HR-pQCT-based versus clinical QCT-based image data; ipsilateral versus contralateral side; and bone mineral content (BMC) versus bone mineral density (BMD). All investigated density measures were significantly correlated with the experimental cycles to failure. The best performing clinically feasible parameter was the QCT-based BMC of the contralateral articular cap region, providing significantly better correlation (R 2  = 0.53) compared to a previously proposed clinical density measure (R 2  = 0.30). BMC had consistently, but not significantly stronger correlations with failure than BMD. The overall best results were obtained with the ipsilateral HR-pQCT-based local BMC (R 2  = 0.74) that may be used for implant optimization. Strong correlations were found between the corresponding density measures of the two CT image sources, as well as between the two sides. Future studies should investigate if BMC of the contralateral articular cap region could provide improved prediction of clinical fixation failure compared to previously proposed measures. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  17. Measurement of lung function in awake 2-4-year-old asthmatic children during methacholine challenge and acute asthma

    DEFF Research Database (Denmark)

    Klug, B; Bisgaard, H

    1996-01-01

    This study evaluated three techniques for testing of lung function in young awake children. We compared measurements by the forced or impulse oscillation technique (IOS), the interrupter technique (IT), and transcutaneous measurements of oxygen (tcPo2) with concomitant measurements of specific ai...

  18. Quantitative evaluation of emphysematous changes in the lung by computed tomography (CT)

    International Nuclear Information System (INIS)

    Kitahara, Yoshinari; Hirayama, Takanobu; Hiratsuka, Toshihiko; Tanaka, Yasushi; Takamoto, Masahiro; Ishibashi, Tsuneo; Shinoda, Atsushi

    1987-01-01

    The present studies were undertaken to quantitatively evaluate emphysematous changes in the lung by CT scan. CT scans were made at inspiration and expiration at three levels (base, mid thorax and apex). Low density lesion ratio (LL %) was measured as the proportion of the area under -950 Housfield Unit in each lung field at expiration. Each value of LL % was determined in 6 lung fields (both lung fields at three levels). The LL % was calculated from the mean of these six values. The results suggest that LL % of the emphysematous lungs shows significant elevation of the values compared with those of normal lungs and lungs with bronchial asthma. (author)

  19. Calculation of new snow densities from sub-daily automated snow measurements

    Science.gov (United States)

    Helfricht, Kay; Hartl, Lea; Koch, Roland; Marty, Christoph; Lehning, Michael; Olefs, Marc

    2017-04-01

    In mountain regions there is an increasing demand for high-quality analysis, nowcasting and short-range forecasts of the spatial distribution of snowfall. Operational services, such as for avalanche warning, road maintenance and hydrology, as well as hydropower companies and ski resorts need reliable information on the depth of new snow (HN) and the corresponding water equivalent (HNW). However, the ratio of HNW to HN can vary from 1:3 to 1:30 because of the high variability of new snow density with respect to meteorological conditions. In the past, attempts were made to calculate new snow densities from meteorological parameters mainly using daily values of temperature and wind. Further complex statistical relationships have been used to calculate new snow densities on hourly to sub-hourly time intervals to drive multi-layer snow cover models. However, only a few long-term in-situ measurements of new snow density exist for sub-daily time intervals. Settling processes within the new snow due to loading and metamorphism need to be considered when computing new snow density. As the effect of these processes is more pronounced for long time intervals, a high temporal resolution of measurements is desirable. Within the pluSnow project data of several automatic weather stations with simultaneous measurements of precipitation (pluviometers), snow water equivalent (SWE) using snow pillows and snow depth (HS) measurements using ultrasonic rangers were analysed. New snow densities were calculated for a set of data filtered on the basis of meteorological thresholds. The calculated new snow densities were compared to results from existing new snow density parameterizations. To account for effects of settling of the snow cover, a case study based on a multi-year data set using the snow cover model SNOWPACK at Weissfluhjoch was performed. Measured median values of hourly new snow densities at the different stations range from 54 to 83 kgm-3. This is considerably lower than a 1

  20. Measuring the density and viscosity of H2S-loaded aqueous methyldiethanolamine solution

    International Nuclear Information System (INIS)

    Shokouhi, Mohammad; Ahmadi, Reza

    2016-01-01

    Highlights: • Measurement solubility of H 2 S in 46.78 mass% MDEA aqueous solutions. • Measurement density of H 2 S loaded of MDEA aqueous solution. • Measurement viscosity of H 2 S loaded of MDEA aqueous solution. • Correlation of the density and viscosity of H 2 S loaded of MDEA aqueous solution using modified setchenow equation. - Abstract: The density and viscosity of H 2 S-loaded aqueous 46.78 mass% methyldiethanolamine solution were experimentally measured accompanied with the solubility of H 2 S at temperatures (313.15, 328.15 and 343.15) K, pressures from vapor pressure of fresh solution up to 1.0 MPa and loadings up to 1.00 mol of H 2 S per 1 mol of amine. All experimental trials have been carried out using the new setup developed in our laboratory. It was observed that both density and viscosity of mixtures decrease by increasing temperature and density increase by increasing acid gas solubility (loading) by about 4.7%, whereas viscosity has a complicated behavior with H 2 S solubility. Viscosity decreases by increasing acid gas solubility (loading) at 313.15 K by about 20.6% and at 328.15 K by about 15.0%, but it is comparable at 343.15 K in terms of H 2 S solubility. Finally, the experimental density and viscosity data correlated using Modified Setchenow equation.

  1. Digital radiography density measurements in differentiation between periapical granulomas and radicular cysts.

    Science.gov (United States)

    Rózyło-Kalinowska, Ingrid

    2007-05-01

    The distinction between radicular cysts and apical granulomas is a matter of considerable importance in making a treatment decision. Because there are no clearly defined radiographic criteria, the distinction is made on the grounds of size. However, it has been suggested that cysts can be distinguished from granulomas on the basis of their radiometric density. The results of previous studies have proved conflicting. To determine possibilities of application of digital radiography density measurements in differentiation of periapical granulomas and radicular cysts of inflammatory origin. The material consisted of 355 digital periapical radiograms obtained using Digora, RVG and Dixi 2 digital radiography systems in patients aged 20 to 84, divided into two groups: 259 granulomas and 102 radicular cysts. By means of Digora 2.0 software there were measured maximum and minimum densities along a line, then there was calculated the difference between maximum and minimum density. The largest dimensions of the lesions were measured - perpendicular and parallel to the root canal axis. It was proved that to some extent it was possible to differentiate cystic granulomas and radicular cysts on the basis of the difference between maximum and minimum density in linear measurement - when the difference exceeded 85.6 the lesion was a cyst and when it was below 45.9 a granuloma was diagnosed. Combination of two criteria - the calculated difference between densities and the largest dimension of a lesion, increased diagnostic possibilities of radiological differentiation of granulomas and radicular cysts.

  2. Bayesian Semiparametric Density Deconvolution in the Presence of Conditionally Heteroscedastic Measurement Errors

    KAUST Repository

    Sarkar, Abhra

    2014-10-02

    We consider the problem of estimating the density of a random variable when precise measurements on the variable are not available, but replicated proxies contaminated with measurement error are available for sufficiently many subjects. Under the assumption of additive measurement errors this reduces to a problem of deconvolution of densities. Deconvolution methods often make restrictive and unrealistic assumptions about the density of interest and the distribution of measurement errors, e.g., normality and homoscedasticity and thus independence from the variable of interest. This article relaxes these assumptions and introduces novel Bayesian semiparametric methodology based on Dirichlet process mixture models for robust deconvolution of densities in the presence of conditionally heteroscedastic measurement errors. In particular, the models can adapt to asymmetry, heavy tails and multimodality. In simulation experiments, we show that our methods vastly outperform a recent Bayesian approach based on estimating the densities via mixtures of splines. We apply our methods to data from nutritional epidemiology. Even in the special case when the measurement errors are homoscedastic, our methodology is novel and dominates other methods that have been proposed previously. Additional simulation results, instructions on getting access to the data set and R programs implementing our methods are included as part of online supplemental materials.

  3. Bayesian Semiparametric Density Deconvolution in the Presence of Conditionally Heteroscedastic Measurement Errors

    KAUST Repository

    Sarkar, Abhra; Mallick, Bani K.; Staudenmayer, John; Pati, Debdeep; Carroll, Raymond J.

    2014-01-01

    We consider the problem of estimating the density of a random variable when precise measurements on the variable are not available, but replicated proxies contaminated with measurement error are available for sufficiently many subjects. Under the assumption of additive measurement errors this reduces to a problem of deconvolution of densities. Deconvolution methods often make restrictive and unrealistic assumptions about the density of interest and the distribution of measurement errors, e.g., normality and homoscedasticity and thus independence from the variable of interest. This article relaxes these assumptions and introduces novel Bayesian semiparametric methodology based on Dirichlet process mixture models for robust deconvolution of densities in the presence of conditionally heteroscedastic measurement errors. In particular, the models can adapt to asymmetry, heavy tails and multimodality. In simulation experiments, we show that our methods vastly outperform a recent Bayesian approach based on estimating the densities via mixtures of splines. We apply our methods to data from nutritional epidemiology. Even in the special case when the measurement errors are homoscedastic, our methodology is novel and dominates other methods that have been proposed previously. Additional simulation results, instructions on getting access to the data set and R programs implementing our methods are included as part of online supplemental materials.

  4. Breast fat volume measurement using wide-bore 3 T MRI: comparison of traditional mammographic density evaluation with MRI density measurements using automatic segmentation.

    Science.gov (United States)

    Petridou, E; Kibiro, M; Gladwell, C; Malcolm, P; Toms, A; Juette, A; Borga, M; Dahlqvist Leinhard, O; Romu, T; Kasmai, B; Denton, E

    2017-07-01

    To compare magnetic resonance imaging (MRI)-derived breast density measurements using automatic segmentation algorithms with radiologist estimations using the Breast Imaging Reporting and Data Systems (BI-RADS) density classification. Forty women undergoing mammography and dynamic breast MRI as part of their clinical management were recruited. Fat-water separated MRI images derived from a two-point Dixon technique, phase-sensitive reconstruction, and atlas-based segmentation were obtained before and after intravenous contrast medium administration. Breast density was assessed using software from Advanced MR Analytics (AMRA), Linköping, Sweden, with results compared to the widely used four-quartile quantitative BI-RADS scale. The proportion of glandular tissue in the breast on MRI was derived from the AMRA sequence. The mean unenhanced breast density was 0.31±0.22 (mean±SD; left) and 0.29±0.21 (right). Mean breast density on post-contrast images was 0.32±0.19 (left) and 0.32±0.2 (right). There was "almost perfect" correlation between pre- and post-contrast breast density quantification: Spearman's correlation rho=0.98 (95% confidence intervals [CI]: 0.97-0.99; left) and rho=0.99 (95% CI: 0.98-0.99; right). The 95% limits of agreement were -0.11-0.08 (left) and -0.08-0.03 (right). Interobserver reliability for BI-RADS was "substantial": weighted Kappa k=0.8 (95% CI: 0.74-0.87). The Spearman correlation coefficient between BI-RADS and MRI breast density was rho=0.73 (95% CI: 0.60-0.82; left) and rho=0.75 (95% CI: 0.63-0.83; right) which was also "substantial". The AMRA sequence provides a fully automated, reproducible, objective assessment of fibroglandular breast tissue proportion that correlates well with mammographic assessment of breast density with the added advantage of avoidance of ionising radiation. Copyright © 2017 The Royal College of Radiologists. All rights reserved.

  5. Comparison of measured and estimated maximum skin doses during CT fluoroscopy lung biopsies

    Energy Technology Data Exchange (ETDEWEB)

    Zanca, F., E-mail: Federica.Zanca@med.kuleuven.be [Department of Radiology, Leuven University Center of Medical Physics in Radiology, UZ Leuven, Herestraat 49, 3000 Leuven, Belgium and Imaging and Pathology Department, UZ Leuven, Herestraat 49, Box 7003 3000 Leuven (Belgium); Jacobs, A. [Department of Radiology, Leuven University Center of Medical Physics in Radiology, UZ Leuven, Herestraat 49, 3000 Leuven (Belgium); Crijns, W. [Department of Radiotherapy, UZ Leuven, Herestraat 49, 3000 Leuven (Belgium); De Wever, W. [Imaging and Pathology Department, UZ Leuven, Herestraat 49, Box 7003 3000 Leuven, Belgium and Department of Radiology, UZ Leuven, Herestraat 49, 3000 Leuven (Belgium)

    2014-07-15

    Purpose: To measure patient-specific maximum skin dose (MSD) associated with CT fluoroscopy (CTF) lung biopsies and to compare measured MSD with the MSD estimated from phantom measurements, as well as with the CTDIvol of patient examinations. Methods: Data from 50 patients with lung lesions who underwent a CT fluoroscopy-guided biopsy were collected. The CT protocol consisted of a low-kilovoltage (80 kV) protocol used in combination with an algorithm for dose reduction to the radiology staff during the interventional procedure, HandCare (HC). MSD was assessed during each intervention using EBT2 gafchromic films positioned on patient skin. Lesion size, position, total fluoroscopy time, and patient-effective diameter were registered for each patient. Dose rates were also estimated at the surface of a normal-size anthropomorphic thorax phantom using a 10 cm pencil ionization chamber placed at every 30°, for a full rotation, with and without HC. Measured MSD was compared with MSD values estimated from the phantom measurements and with the cumulative CTDIvol of the procedure. Results: The median measured MSD was 141 mGy (range 38–410 mGy) while the median cumulative CTDIvol was 72 mGy (range 24–262 mGy). The ratio between the MSD estimated from phantom measurements and the measured MSD was 0.87 (range 0.12–4.1) on average. In 72% of cases the estimated MSD underestimated the measured MSD, while in 28% of the cases it overestimated it. The same trend was observed for the ratio of cumulative CTDIvol and measured MSD. No trend was observed as a function of patient size. Conclusions: On average, estimated MSD from dose rate measurements on phantom as well as from CTDIvol of patient examinations underestimates the measured value of MSD. This can be attributed to deviations of the patient's body habitus from the standard phantom size and to patient positioning in the gantry during the procedure.

  6. Comparison of measured and estimated maximum skin doses during CT fluoroscopy lung biopsies

    International Nuclear Information System (INIS)

    Zanca, F.; Jacobs, A.; Crijns, W.; De Wever, W.

    2014-01-01

    Purpose: To measure patient-specific maximum skin dose (MSD) associated with CT fluoroscopy (CTF) lung biopsies and to compare measured MSD with the MSD estimated from phantom measurements, as well as with the CTDIvol of patient examinations. Methods: Data from 50 patients with lung lesions who underwent a CT fluoroscopy-guided biopsy were collected. The CT protocol consisted of a low-kilovoltage (80 kV) protocol used in combination with an algorithm for dose reduction to the radiology staff during the interventional procedure, HandCare (HC). MSD was assessed during each intervention using EBT2 gafchromic films positioned on patient skin. Lesion size, position, total fluoroscopy time, and patient-effective diameter were registered for each patient. Dose rates were also estimated at the surface of a normal-size anthropomorphic thorax phantom using a 10 cm pencil ionization chamber placed at every 30°, for a full rotation, with and without HC. Measured MSD was compared with MSD values estimated from the phantom measurements and with the cumulative CTDIvol of the procedure. Results: The median measured MSD was 141 mGy (range 38–410 mGy) while the median cumulative CTDIvol was 72 mGy (range 24–262 mGy). The ratio between the MSD estimated from phantom measurements and the measured MSD was 0.87 (range 0.12–4.1) on average. In 72% of cases the estimated MSD underestimated the measured MSD, while in 28% of the cases it overestimated it. The same trend was observed for the ratio of cumulative CTDIvol and measured MSD. No trend was observed as a function of patient size. Conclusions: On average, estimated MSD from dose rate measurements on phantom as well as from CTDIvol of patient examinations underestimates the measured value of MSD. This can be attributed to deviations of the patient's body habitus from the standard phantom size and to patient positioning in the gantry during the procedure

  7. Clinical assessment of mean washout time and lung functional image by ventilatory steady state measurement with /sup 133/Xe

    Energy Technology Data Exchange (ETDEWEB)

    Kimura, K; Hasegawa, T; Watanabe, H; Hasegawa, S; Oshima, M [Tsukuba Univ., Sakura, Ibaraki (Japan)

    1981-04-01

    Ventilatory steady state measurement with /sup 133/Xe, using Ventil-Con (Radx) and a large area scintillation camera (Searle, LFOV) combined with a mini-computer system (Shimadzu, Scintipac 230) was employed to evaluate regional pulmonary function of 94 patients with chronic obstructive lung disease (COLD), fibrosis, carcinoma and other lung diseases. In the patients with COLD, mean washout times (anti t) were markedly prolonged in whole lung fields (anti m 130 +- 33 sec.) and ventilation indices (V*/V) (*: radical) and perfusion indices (Q*/V) (*: radical) were reduced in regional zones, especially in bilateral lower lung zones. For the patients with lung fibrosis, anti t values were short and the distribution of ventilation indices were uniform, and in contrast perfusion indices were reduced in the lower lung fields. In the area most affected by carcinoma, lung volumes (V) were reduced in parallel with the regional ventilation (V*) (*: radical) and perfusion (Q*) (*: radical). As the tumor approached the hilum, the relative ventilation and perfusion of cancerous side decreased remarkably in patients with obstructive findings on bronchoscopy. The mean washout times (anti t) for /sup 133/Xe, calculated by a modified height over area method without background subtraction, were significantly longer than indicated by the data yielded by the least squares curve fitting of initial washout curve after background subtraction. Although the accuracy of these data was limited, it appeared that the prolonged anti t is a good parameter of regional ventilatory disturbance because significant correlations were found between the whole lung anti t in patients with lung diseases and their FEV 1.0% r = -0.66, RV/TLC r = 0.64, % TLC r = 0.43, PaCO/sub 2/ r = 0.41, PaO/sub 2/ r = -0.35.

  8. Simultaneous measurements of temperature and density in air flows using UV laser spectroscopy

    Science.gov (United States)

    Fletcher, D. G.; Mckenzie, R. L.

    1991-01-01

    The simultaneous measurement of temperature and density using laser-induced fluorescence of oxygen in combination with Q-branch Raman scattering of nitrogen and oxygen is demonstrated in a low-speed air flow. The lowest density and temperature measured in the experiment correspond to the freestream values at Mach 5 in the Ames 3.5-Foot Hypersonic Wind Tunnel for stagnation conditions of 100 atm and 1000 K. The experimental results demonstrate the viability of the optical technique for measurements that support the study of compressible turbulence and the validation of numerical codes in supersonic and hypersonic wind tunnel flows.

  9. Simultaneous measurement of line electron density and Faraday rotation in the ISX-B tokamak

    International Nuclear Information System (INIS)

    Hutchinson, D.P.; Ma, C.H.; Staats, P.A.; Vander Sluis, K.L.

    1981-01-01

    A new diagnostic system utilizing a submillimetre-wave, phase-modulated polarimeter/interferometer has been used to simultaneously measure the time evolution of the line-averaged electron density and poloidal field-induced Faraday rotation in the ISX-B tokamak. The measurements, performed along four chords of the plasma column, have been correlated with poloidal field changes associated with a ramp in the Ohmic-heating current and by neutral-beam injection. These are the first simultaneous measurements of line electron density and Faraday rotation to be made along a chord of submillimetre laser beam in a tokamak plasma. (author)

  10. Electronic density measurement in the TB R-1 tokamak using Faraday rotation

    International Nuclear Information System (INIS)

    Elizondo, Juan Iraburu

    1996-01-01

    In this work, the experimental results of electronic density measurements in the TBR-1 tokamak, obtained by Faraday rotation of a microwave beam, are presented, The beam (65 GHz, 500 MW) is generated by a Klystron and crosses the plasma in the horizontal plane. The density values obtained are in agreement with the measurements of a conventional microwave interferometer. As a result of numerical simulations and measurements, it can be concluded that it would be advisable the use of lower wavelengths, to minimize the beam refraction when it crosses the plasma. The results show the feasibility of the Faraday rotation method for density measurement, in the first experiment performed in a tokamak, for the geometry considered. (author)

  11. Brain parenchymal density measurements by CT in demented subjects and normal controls

    International Nuclear Information System (INIS)

    Gado, M.; Danziger, W.L.; Chi, D.; Hughes, C.P.; Coben, L.A.

    1983-01-01

    Parachymal density measurements of 14 regions of gray and white matter from each cerebral hemisphere were made from CT scans of 25 subjects who had varying degrees of dementia as measured by a global Clinical Dementia Rating, and also from CT scans of 33 normal control subjects. There were few significant differences between the two groups in the mean density value for each of the regions examined, although several individual psychometric tests did correlate with density changes. Moreover, for six regions in the cerebral cortex, and for one region in the thalamus of each hemisphere, we found no significant correlation between the gray-white matter density difference and dementia. There was, however, a loss of the discriminability between the gray and white matter with an increase in the size of the ventricles. These findings may be attributed to the loss of white matter volume

  12. Viscosity and Liquid Density of Asymmetric n-Alkane Mixtures: Measurement and Modelling

    DEFF Research Database (Denmark)

    Queimada, António J.; Marrucho, Isabel M.; Coutinho, João A.P.

    2005-01-01

    Viscosity and liquid density Measurements were performed, at atmospheric pressure. in pure and mixed n-decane. n-eicosane, n-docosane, and n-tetracosane from 293.15 K (or above the melting point) up to 343.15 K. The viscosity was determined with a rolling ball viscometer and liquid densities...... with a vibrating U-tube densimeter. Pure component results agreed, oil average, with literature values within 0.2% for liquid density and 3% for viscosity. The measured data were used to evaluate the performance of two models for their predictions: the friction theory coupled with the Peng-Robinson equation...... of state and a corresponding states model recently proposed for surface tension, viscosity, vapor pressure, and liquid densities of the series of n-alkanes. Advantages and shortcoming of these models are discussed....

  13. Interpretation of heat and density pulse measurements in JET in terms of coupled transport

    International Nuclear Information System (INIS)

    Haas, J.C.M. de; O'Rourke, J.; Sips, A.C.C.; Lopes Cardozo, N.J.

    1990-01-01

    The perturbations of electron density and temperature profiles in a tokamak following a sawtooth collapse are considered. An analytic model for the interpretation of such perturbations is presented. It is shown that the perturbation can be decomposed into two contributions, which are eigenmodes of the linearised coupled diffusion equations for particle and energy. The approximations made in the analytical treatment are checked using computer simulations. Measurements of heat and density pulses in Joint European Torus are used to illustrate the power of the new approach. It is shown that using the coupled equations, an improved description of the heat and density pulses is obtained. The analysis yields the four diffusion coefficients in the linearised transport matrix. The non-zero off-diagonal elements explain certain salient features of the measurements, notably a marked decrease of the local density which occurs during the maximum of the temperature pulse. (author)

  14. Technique of Critical Current Density Measurement of Bulk Superconductor with Linear Extrapolation Method

    International Nuclear Information System (INIS)

    Adi, Wisnu Ari; Sukirman, Engkir; Winatapura, Didin S.

    2000-01-01

    Technique of critical current density measurement (Jc) of HTc bulk ceramic superconductor has been performed by using linear extrapolation with four-point probes method. The measurement of critical current density HTc bulk ceramic superconductor usually causes damage in contact resistance. In order to decrease this damage factor, we introduce extrapolation method. The extrapolating data show that the critical current density Jc for YBCO (123) and BSCCO (2212) at 77 K are 10,85(6) Amp.cm - 2 and 14,46(6) Amp.cm - 2, respectively. This technique is easier, simpler, and the use of the current flow is low, so it will not damage the contact resistance of the sample. We expect that the method can give a better solution for bulk superconductor application. Key words. : superconductor, critical temperature, and critical current density

  15. Shuttle high resolution accelerometer package experiment results - Atmospheric density measurements between 60-160 km

    Science.gov (United States)

    Blanchard, R. C.; Hinson, E. W.; Nicholson, J. Y.

    1988-01-01

    Indirect or inferred values of atmospheric density encountered by the Shuttle Orbiter during reentry have been calculated from acceleration measurements made by the High Resolution Accelerometer Package (HiRAP) and the Orbiter Inertial Measurement Unit (IMU) liner accelerometers. The atmospheric density data developed from this study represent a significant gain with respect to the body of data collected to date by various techniques in the altitude range of 60 to 160 km. The data are unique in that they cover a very wide horizontal range during each flight and provide insight into the actual density variations encountered along the reentry flight path. The data, which were collected over about 3 years, are also characterized by variations in solar activity, geomagnetic index, and local solar time. Comparison of the flight-derived densities with various atmospheric models have been made, and analyses have attempted to characterize the data and to show correlation with selected physical variables.

  16. Eight-chord CO2 interferometer for plasma-density measurements on ZT-40

    International Nuclear Information System (INIS)

    Jacobson, A.R.; Jolin, L.J.

    1981-01-01

    We describe a CO 2 laser interferometer which measures the path-integrated density along eight different chords simultaneously in the ZT-40 reversed-field pinch, a toroidal magnetic confinement experiment at Los Alamos. The interferometer system combines several reliable, commercially available components in a package which provides exceptional measurement resolution as well as ease of operation and maintenance

  17. Measurement of the density profile of pure and seeded molecular beams by femtosecond ion imaging

    NARCIS (Netherlands)

    Meng, C.; Janssen, M.H.M.

    2015-01-01

    Here, we report on femtosecond ion imaging experiments to measure the density profile of a pulsed supersonic molecular beam. Ion images are measured for both a molecular beam and bulk gas under identical experimental conditions via femtosecond multiphoton ionization of Xe atoms. We report the

  18. Density-independent algorithm for sensing moisture content of sawdust based on reflection measurements

    Science.gov (United States)

    A density-independent algorithm for moisture content determination in sawdust, based on a one-port reflection measurement technique is proposed for the first time. Performance of this algorithm is demonstrated through measurement of the dielectric properties of sawdust with an open-ended haft-mode s...

  19. Particle image velocimetry measurements and numerical modeling of a saline density current

    CSIR Research Space (South Africa)

    Gerber, G

    2011-03-01

    Full Text Available Particle image velocimetry scalar measurements were carried out on the body of a stably stratified density current with an inlet Reynolds number of 2,300 and bulk Richardson number of 0.1. These measurements allowed the mass and momentum transport...

  20. Measurement of water content and density of soil using photon multiplescattering

    International Nuclear Information System (INIS)

    Ertek, C.; Haselberger, N.

    1981-04-01

    A gamma-backscatter gauge for field and laboratory applications was set up for the measurement of density and water content of soil at the same time. The method works successfully between 0-40 cm depth of the soil and is superior to the neutron gauge between 0-30 cm depth. The system is extremely simple and practical and can be installed on a tractor during ploughing. The developed method also works for absolute values of densities and moisture content and is able to distinguish the bulk density changes due to vacancies in the soil or the water content taken inside the soil grains

  1. Ultrasonic density detector for vessel and reactor core two-phase flow measurements

    International Nuclear Information System (INIS)

    Arave, A.E.

    1979-01-01

    A local ultrasonic density (LUD) detector has been developed by EG and G Idaho, Inc., at the Idaho National Engineering Laboratory for the Loss-of-Fluid Test (LOFT) reactor vessel and core two-phase flow density measurements. The principle of operating the sensor is the change in propagation time of a torsional ultrasonic wave in a metal transmission line as a function of the density of the surrounding media. A theoretical physics model is presented which represents the total propagation time as a function of the sensor modulus of elasticity and polar moment of inertia

  2. 2D electron density profile measurement in tokamak by laser-accelerated ion-beam probe.

    Science.gov (United States)

    Chen, Y H; Yang, X Y; Lin, C; Wang, L; Xu, M; Wang, X G; Xiao, C J

    2014-11-01

    A new concept of Heavy Ion Beam Probe (HIBP) diagnostic has been proposed, of which the key is to replace the electrostatic accelerator of traditional HIBP by a laser-driven ion accelerator. Due to the large energy spread of ions, the laser-accelerated HIBP can measure the two-dimensional (2D) electron density profile of tokamak plasma. In a preliminary simulation, a 2D density profile was reconstructed with a spatial resolution of about 2 cm, and with the error below 15% in the core region. Diagnostics of 2D density fluctuation is also discussed.

  3. Comparison of ICRP Publication 30 lung model-based predictions with measured bioassay data for airborne natural UO2 exposure

    International Nuclear Information System (INIS)

    Thind, K.S.

    1987-01-01

    In this paper a comparison is made between the build-up of U thorax burdens and the predicted total lung (lung and lymph) burden, based on the lung model provided in ICRP Publication 30 for a group of 29 atomic radiation workers at a Canadian fuel fabrication facility. A similar comparison is made between the predicted ratio of the total lung burden to urinary excretion and the ratio obtained from bioassay data. The study period for the comparison is 5 y. The inhalation input for the lung model calculations was derived from air-sampling data and the choice of particle size activity median aerodynamic diameter (AMAD) was guided by particle size measurements made at representative work locations. The pulmonary clearance half-times studied were 100, 250 and 500 d. For the purpose of this comparison, averaged exposure and averaged bioassay data for the group were used. This comparison indicates that for the conditions of this facility, the assumption of a 500-d pulmonary clearance half-time and a particle size of 1 micron (AMAD) may be too conservative. It is suggested that measurements of air concentrations and particle size used as input parameters for the ICRP Publication 30 lung model may be used to calculate bioassay parameters which may then be tested against bioassay data obtained as part of an operational health physics program, thereby giving a useful step towards defining a derived air concentration value for U in the workplace

  4. Density Measurement of Liquid Ni-Ta Alloys by a Modified Sessile Drop Method

    Institute of Scientific and Technical Information of China (English)

    FANG Liang; XIAO Feng; TAO Zainan; Kusuhiro Mukai

    2005-01-01

    The density of liquid Ni-Ta alloys was measured by using a modified sessile drop method. It is found that the density of the liquid Ni-Ta alloys decreases with the increasing temperature, but increases with the increase of tantalum concentration in the alloys. The molar volume of liquid Ni-Ta binary alloys increases with the increase of temperature and tantalum concentration.

  5. Comparative study of methods to measure the density of Cementious powders

    OpenAIRE

    Helsel, Michelle A.; Ferraris, Chiara F.; Bentz, Dale

    2015-01-01

    The accurate measurement of the density of hydraulic cement has an essential role in the determination of concrete mixture proportions. As more supplementary cementitious materials (SCM), such as fly ash, and slag, or cement replacements materials such as limestone and calcium carbonate are used in blended cements, knowledge of the density of each powder or of the blended cement would allow a more accurate calculation of the proportions of a concrete mixture by volume instead of by mass. The ...

  6. Novel Associations between Common Breast Cancer Susceptibility Variants and Risk-Predicting Mammographic Density Measures

    OpenAIRE

    Stone, Jennifer; Thompson, Deborah J.; dos-Santos-Silva, Isabel; Scott, Christopher; Tamimi, Rulla M.; Lindstrom, Sara; Kraft, Peter; Hazra, Aditi; Li, Jingmei; Eriksson, Louise; Czene, Kamila; Hall, Per; Jensen, Matt; Cunningham, Julie; Olson, Janet E.

    2015-01-01

    Mammographic density measures adjusted for age and body mass index (BMI) are heritable predictors of breast cancer risk but few mammographic density-associated genetic variants have been identified. Using data for 10,727 women from two international consortia, we estimated associations between 77 common breast cancer susceptibility variants and absolute dense area, percent dense area and absolute non-dense area adjusted for study, age and BMI using mixed linear modeling. We found strong suppo...

  7. Measurement of the temperature of density maximum of water solutions using a convective flow technique

    OpenAIRE

    Cawley, M.F.; McGlynn, D.; Mooney, P.A.

    2006-01-01

    A technique is described which yields an accurate measurement of the temperature of density maximum of fluids which exhibit such anomalous behaviour. The method relies on the detection of changes in convective flow in a rectangular cavity containing the test fluid.The normal single-cell convection which occurs in the presence of a horizontal temperature gradient changes to a double cell configuration in the vicinity of the density maximum, and this transition manifests itself in changes in th...

  8. Field mapping measurements to determine spatial and field dependence of critical current density in YBCO tapes

    International Nuclear Information System (INIS)

    Leclerc, J.; Berger, K.; Douine, B.; Lévêque, J.

    2013-01-01

    Highlights: • A method for characterizing superconducting tapes from field mapping is presented. • A new and efficient field mapping apparatus has been setup. • This method allows the spatial characterization of superconducting tapes. • The critical current density is obtained as a function of the flux density. • This method has been experimentally tested on an YBCO tape. -- Abstract: In this paper a measurement method that allows the determination of the critical current density of superconducting tape from field mapping measurements is presented. This contact-free method allows obtaining characteristics of the superconductor as a function of the position and of the applied flux density. With some modifications, this technique can be used for reel-to-reel measurements. The determination of the critical current density is based on an inverse calculation. This involves calculating the current distribution in the tape from magnetic measurements. An YBaCuO tape has been characterized at 77 K. A defect in this superconductor has been identified. Various tests were carried out to check the efficiency of the method. The inverse calculation was tested theoretically and experimentally. Comparison with a transport current measurement was also performed

  9. IN SITU MEASUREMENTS OF THE SIZE AND DENSITY OF TITAN AEROSOL ANALOGS

    Energy Technology Data Exchange (ETDEWEB)

    Hoerst, S. M.; Tolbert, M. A, E-mail: sarah.horst@colorado.edu [Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO (United States)

    2013-06-10

    The organic haze produced from complex CH{sub 4}/N{sub 2} chemistry in the atmosphere of Titan plays an important role in processes that occur in the atmosphere and on its surface. The haze particles act as condensation nuclei and are therefore involved in Titan's methane hydrological cycle. They also may behave like sediment on Titan's surface and participate in both fluvial and aeolian processes. Models that seek to understand these processes require information about the physical properties of the particles including their size and density. Although measurements obtained by Cassini-Huygens have placed constraints on the size of the haze particles, their densities remain unknown. We have conducted a series of Titan atmosphere simulation experiments and measured the size, number density, and particle density of Titan aerosol analogs, or tholins, for CH{sub 4} concentrations from 0.01% to 10% using two different energy sources, spark discharge and UV. We find that the densities currently in use by many Titan models are higher than the measured densities of our tholins.

  10. IN SITU MEASUREMENTS OF THE SIZE AND DENSITY OF TITAN AEROSOL ANALOGS

    International Nuclear Information System (INIS)

    Hörst, S. M.; Tolbert, M. A

    2013-01-01

    The organic haze produced from complex CH 4 /N 2 chemistry in the atmosphere of Titan plays an important role in processes that occur in the atmosphere and on its surface. The haze particles act as condensation nuclei and are therefore involved in Titan's methane hydrological cycle. They also may behave like sediment on Titan's surface and participate in both fluvial and aeolian processes. Models that seek to understand these processes require information about the physical properties of the particles including their size and density. Although measurements obtained by Cassini-Huygens have placed constraints on the size of the haze particles, their densities remain unknown. We have conducted a series of Titan atmosphere simulation experiments and measured the size, number density, and particle density of Titan aerosol analogs, or tholins, for CH 4 concentrations from 0.01% to 10% using two different energy sources, spark discharge and UV. We find that the densities currently in use by many Titan models are higher than the measured densities of our tholins.

  11. Regional measurement of ventilation and perfusion to detect subtle lung abnormalities in coal miners

    International Nuclear Information System (INIS)

    Susskind, H.; Liu, J.; Brill, A.B.

    1986-01-01

    The relationship between regional pulmonary ventilation (V) and perfusion (Q) uniquely determines the amount of gas exchange that occurs in the lungs. Therefore, the pixel-by-pixel distributions of V and Q were measured with continuously inhaled Kr-81m and i.v. injected Tc-99m MAA, respectively, in a group of 71 subjects exposed to coal dust and then compared with those from a control group of 9 healthy volunteers. Each subject sat upright with his back against a large-field-of-view scintillation camera; 500,000 count images were obtained, analyzed by computer, and then displayed in a 64 x 64 matrix. Individual pixel values of V and Q were correlated by a best-fit regression line, whose slope was proportional to the overall V/Q ratio. The slopes of individual groups of nonsmokers, ex-smokers, and smokers (0.83-0.85) were significantly greater (p < 0.02) than the slope of the controls (0.70 +/- 0.07). In addition, the authors found that the skewness of plots of frequency distribution of V/Q and of V and Q vs V/Q for the individual patient groups was statistically different from that of the normals (p < 0.01). Statistical analysis of local and Q values therefore appears to be a potentially useful, non-invasive method to evaluate subtle regional lung impairment

  12. Tibial shock measured during the fencing lunge: the influence of footwear.

    Science.gov (United States)

    Sinclair, Jonathan; Bottoms, Lindsay; Taylor, Katrina; Greenhalgh, Andrew

    2010-06-01

    Fencing is a high-intensity sport involving dynamic movements such as the lunge exposing the musculoskeletal system to high impact forces, which emphasises the importance of the shock attenuating properties of footwear as a factor in the prevention of injury. The aim of this study was to investigate the magnitudes of the transient axial impact shock experienced at the tibia between traditional fencing shoes and standard athletic footwear during the impact phase of the fencing lunge. Peak tibial shock was measured in 19 male fencers in 4 different footwear conditions using an accelerometer placed on the distal aspect of the tibia. The standard footwear (11.08 g and 8.75 g for squash and running shoe, respectively) resulted in significant (p Adidas and Hi-Tec shoe, respectively). No significant differences were found between the running and squash shoes (p = 0.09) or between the fencing shoes (p = 0.48). The documented reduction in impact shock found suggests that running or squash specific footwear may reduce overuse injury occurrence, indicating that there is justification for a re-design of fencing shoes.

  13. Evaluation of the ion-density measurements by the Indian satellite SROSS-C2

    Science.gov (United States)

    Subrahmanyam, P.; Jain, A. R.; Maini, H. K.; Bahl, M.; Das, Rupesh M.; Garg, S. C.; Niranjan, K.

    2010-12-01

    The ion and electron F region plasma measurements made by the ion and electron Retarding Potential Analyzers (RPAs) onboard the Indian satellite SROSS-C2, have yielded excellent data set over the Indian region for more than half a solar cycle, after the SROSS-C2 launch in May 1994. The absolute ion density, ion temperature, and ion composition parameters are derived from these in situ measurements and used by many workers. In this paper the absolute values of ion density derived from the ion RPA measurements are compared and evaluated with the measurements made by ground-based ionosondes located in the Indian region and close to the SROSS-C2 orbital path. It is shown that a slight adjustment in efficiency factor of the ion RPA sensor brings the in situ measurements much closer to those obtained from the ground-based ionosonde measurements taking into account the model calculations. It may be mentioned that this is a correction to the ion density measurement by SROSS-C2 by a fixed proportion (14-11.4%). The effect of change in efficiency factor on the ion current, which is used to deduce the ion number density, is demonstrated and discussed.

  14. UF6 Density and Mass Flow Measurements for Enrichment Plants using Acoustic Techniques

    Energy Technology Data Exchange (ETDEWEB)

    Good, Morris S.; Smith, Leon E.; Warren, Glen A.; Jones, Anthony M.; Ramuhalli, Pradeep; Roy, Surajit; Moran, Traci L.; Denslow, Kayte M.; Longoni, Gianluca

    2017-09-01

    A key enabling capability for enrichment plant safeguards being considered by the International Atomic Energy Agency (IAEA) is high-accuracy, noninvasive, unattended measurement of UF6 gas density and mass flow rate. Acoustic techniques are currently used to noninvasively monitor gas flow in industrial applications; however, the operating pressures at gaseous centrifuge enrichment plants (GCEPs) are roughly two orders magnitude below the capabilities of commercial instrumentation. Pacific Northwest National Laboratory is refining acoustic techniques for estimating density and mass flow rate of UF6 gas in scenarios typical of GCEPs, with the goal of achieving 1% measurement accuracy. Proof-of-concept laboratory measurements using a surrogate gas for UF6 have demonstrated signatures sensitive to gas density at low operating pressures such as 10–50 Torr, which were observed over the background acoustic interference. Current efforts involve developing a test bed for conducting acoustic measurements on flowing SF6 gas at representative flow rates and pressures to ascertain the viability of conducting gas flow measurements under these conditions. Density and flow measurements will be conducted to support the evaluation. If successful, the approach could enable an unattended, noninvasive approach to measure mass flow in unit header pipes of GCEPs.

  15. Intra- and inter-observer agreement and reliability of bone mineral density measurements around acetabular cup

    DEFF Research Database (Denmark)

    Mussmann, Bo Redder; Overgaard, Soren; Torfing, Trine

    2017-01-01

    in measuring bone density (BMD) in complex anatomic structures which might be overcome using dual-energy computed tomography (DECT).PurposeTo test inter- and intra-observer agreement and reliability of in-house segmentation software measuring BMD adjacent to acetabular cup and to compare measurements performed...... with single-energy CT (SECT) and DECT in cemented and cementless cups.Material and Methods: Twenty-four acetabular cups inserted in porcine hip specimens were scanned with SECT and DECT. Bone density was measured in a three-dimensional volume adjacent to the cup. Double measurements were performed.......Results: BMD derived from SECT was approximately four times higher than that of DECT. In both scan modes, intraclass correlation coefficient (ICC) was >0.90 with no differences between repeated measurements, except for uncemented cups where a statistically significant difference of 11 mg/cm3 was found...

  16. Effects of density gradients and fluctuations at the plasma edge on ECEI measurements at ASDEX Upgrade

    Science.gov (United States)

    Vanovac, B.; Wolfrum, E.; Denk, S. S.; Mink, F.; Laggner, F. M.; Birkenmeier, G.; Willensdorfer, M.; Viezzer, E.; Hoelzl, M.; Freethy, S. J.; Dunne, M. G.; Lessig, A.; Luhmann, N. C., Jr.; the ASDEX Upgrade Team; the EUROfusion MST1 Team

    2018-04-01

    Electron cyclotron emission imaging (ECEI) provides measurements of electron temperature (T e ) and its fluctuations (δT e ). However, when measuring at the plasma edge, in the steep gradient region, radiation transport effects must be taken into account. It is shown that due to these effects, the scrape-off layer region is not accessible to the ECEI measurements in steady state conditions and that the signal is dominated by the shine-through emission. Transient effects, such as filaments, can change the radiation transport locally, but cannot be distinguished from the shine-through. Local density measurements are essential for the correct interpretation of the electron cyclotron emission, since the density fluctuations influence the temperature measurements at the plasma edge. As an example, a low frequency 8 kHz mode, which causes 10%-15% fluctuations in the signal level of the ECEI, is analysed. The same mode has been measured with the lithium beam emission spectroscopy density diagnostic, and is very well correlated in time with high frequency magnetic fluctuations. With radiation transport modelling of the electron cyclotron radiation in the ECEI geometry, it is shown that the density contributes significantly to the radiation temperature (T rad) and the experimental observations have shown the amplitude modulation in both density and temperature measurements. The poloidal velocity of the low frequency mode measured by the ECEI is 3 km s-1. The calculated velocity of the high frequency mode measured with the magnetic pick-up coils is about 25 km s-1. Velocities are compared with the E × B background flow velocity and possible explanations for the origin of the low frequency mode are discussed.

  17. Plasma dynamics near critical density inferred from direct measurements of laser hole boring

    Science.gov (United States)

    Gong, Chao; Tochitsky, Sergei Ya.; Fiuza, Frederico; Pigeon, Jeremy J.; Joshi, Chan

    2016-06-01

    We have used multiframe picosecond optical interferometry to make direct measurements of the hole boring velocity, vHB, of the density cavity pushed forward by a train of C O2 laser pulses in a near critical density helium plasma. As the pulse train intensity rises, the increasing radiation pressure of each pulse pushes the density cavity forward and the plasma electrons are strongly heated. After the peak laser intensity, the plasma pressure exerted by the heated electrons strongly impedes the hole boring process and the vHB falls rapidly as the laser pulse intensity falls at the back of the laser pulse train. A heuristic theory is presented that allows the estimation of the plasma electron temperature from the measurements of the hole boring velocity. The measured values of vHB, and the estimated values of the heated electron temperature as a function of laser intensity are in reasonable agreement with those obtained from two-dimensional numerical simulations.

  18. Comparison of laser-induced surface damage density measurements with small and large beams: toward representativeness

    International Nuclear Information System (INIS)

    Lamaignere, Laurent; Dupuy, Gabriel; Donval, Thierry; Grua, Pierre; Bercegol, Herve

    2011-01-01

    Pulsed laser damage density measurements obtained with diverse facilities are difficult to compare, due to the interplay of numerous parameters, such as beam area and pulse geometry, which, in operational large beam conditions, are very different from laboratory measurements. This discrepancy could have a significant impact; if so, one could not even pretend that laser damage density control is a real measurement process. In this paper, this concern is addressed. Tests with large beams of centimeter size on a high-power laser facility have beam performed according to a parametric study and are compared to small beam laboratory tests. It is shown that laser damage densities obtained with large and small beams are equal, within calculated error bars.

  19. Frequency-resolved interferometric measurement of local density fluctuations for turbulent combustion analysis

    International Nuclear Information System (INIS)

    Köberl, S; Giuliani, F; Woisetschläger, J; Fontaneto, F

    2010-01-01

    A validation of a novel interferometric measurement technique for the frequency-resolved detection of local density fluctuation in turbulent combustion analysis was performed in this work. Two laser vibrometer systems together with a signal analyser were used to obtain frequency spectra of density fluctuations across a methane-jet flame. Since laser vibrometry is based on interferometric techniques, the derived signals are path-integrals along the measurement beam. To obtain local frequency spectra of density fluctuations, long-time-averaged measurements from each of the two systems were performed using correlation functions and cross spectra. Results were compared to data recorded by standard interferometric techniques for validation purposes. Additionally, Raman scattering and laser Doppler velocimetry were used for flame characterization

  20. Density and moisture measurements by nuclear method and its application to compaction control in road construction

    International Nuclear Information System (INIS)

    Mohd Azmi Ismail

    1994-01-01

    The application of nuclear technique in civil engineering sector which emphasises on the in-situ density and moisture measurements of soil in road construction is discussed. The nuclear density-moisture gauge utilises both gamma-rays and neutrons for the determination of the density and moisture content, respectively. The knowledge on the density and moisture content will be used to evaluate the degree of compaction of the compacted layers. The technique offers not only a fast and non-destructive measurement but it is also accurate, economical and repeatable. A calibration equation which is stored in the built-in microprocessor is applicable for any type of soil. Corrections for the interferences from needless gamma-rays produced as a result of thermal neutrons interaction with certain nuclei for the density measurement and effects of hydrogen other than absorbed water for the moisture measurement are considered in the equation. This paper describes briefly the theory and the characteristics of the nuclear gauge and its application in road construction work

  1. X-ray beam hardening correction for measuring density in linear accelerator industrial computed tomography

    International Nuclear Information System (INIS)

    Zhou Rifeng; Wang Jue; Chen Weimin

    2009-01-01

    Due to X-ray attenuation being approximately proportional to material density, it is possible to measure the inner density through Industrial Computed Tomography (ICT) images accurately. In practice, however, a number of factors including the non-linear effects of beam hardening and diffuse scattered radiation complicate the quantitative measurement of density variations in materials. This paper is based on the linearization method of beam hardening correction, and uses polynomial fitting coefficient which is obtained by the curvature of iron polychromatic beam data to fit other materials. Through theoretical deduction, the paper proves that the density measure error is less than 2% if using pre-filters to make the spectrum of linear accelerator range mainly 0.3 MeV to 3 MeV. Experiment had been set up at an ICT system with a 9 MeV electron linear accelerator. The result is satisfactory. This technique makes the beam hardening correction easy and simple, and it is valuable for measuring the ICT density and making use of the CT images to recognize materials. (authors)

  2. A MEMS Resonant Sensor to Measure Fluid Density and Viscosity under Flexural and Torsional Vibrating Modes

    Directory of Open Access Journals (Sweden)

    Libo Zhao

    2016-06-01

    Full Text Available Methods to calculate fluid density and viscosity using a micro-cantilever and based on the resonance principle were put forward. Their measuring mechanisms were analyzed and the theoretical equations to calculate the density and viscosity were deduced. The fluid-solid coupling simulations were completed for the micro-cantilevers with different shapes. The sensing chips with micro-cantilevers were designed based on the simulation results and fabricated using the micro electromechanical systems (MEMS technology. Finally, the MEMS resonant sensor was packaged with the sensing chip to measure the densities and viscosities of eight different fluids under the flexural and torsional vibrating modes separately. The relative errors of the measured densities from 600 kg/m3 to 900 kg/m3 and viscosities from 200 μPa·s to 1000 μPa·s were calculated and analyzed with different microcantilevers under various vibrating modes. The experimental results showed that the effects of the shape and vibrating mode of micro-cantilever on the measurement accuracies of fluid density and viscosity were analyzed in detail.

  3. Air Density Measurements in a Mach 10 Wake Using Iodine Cordes Bands

    Science.gov (United States)

    Balla, Robert J.; Everhart, Joel L.

    2012-01-01

    An exploratory study designed to examine the viability of making air density measurements in a Mach 10 flow using laser-induced fluorescence of the iodine Cordes bands is presented. Experiments are performed in the NASA Langley Research Center 31 in. Mach 10 air wind tunnel in the hypersonic near wake of a multipurpose crew vehicle model. To introduce iodine into the wake, a 0.5% iodine/nitrogen mixture is seeded using a pressure tap at the rear of the model. Air density was measured at 56 points along a 7 mm line and three stagnation pressures of 6.21, 8.62, and 10.0 MPa (900, 1250, and 1450 psi). Average results over time and space show rho(sub wake)/rho(sub freestream) of 0.145 plus or minus 0.010, independent of freestream air density. Average off-body results over time and space agree to better than 7.5% with computed densities from onbody pressure measurements. Densities measured during a single 60 s run at 10.0 MPa are time-dependent and steadily decrease by 15%. This decrease is attributed to model forebody heating by the flow.

  4. Precision flux density measurements of the giant planets at 8420 MHz

    Science.gov (United States)

    Turegano, J. A.; Klein, M. J.

    1981-01-01

    Precision measurements of the 3.56 cm flux densities of Jupiter, Saturn, Uranus, and Neptune are reported. The results are compared with previously published measurements as a means of: remotely sensing long-term changes in the microwave emission from the atmospheres of these planets and measuring the effects of Saturn's rings on the disk temperature as observed from earth at different ring inclination angles.

  5. Calculations and measurements of β-ray attenuation for determining density in an inhomogenous medium

    International Nuclear Information System (INIS)

    Williamson, T.G.; Mackinnon, J.G.; Frisch, A.F.; Jenkins, R.W. Jr.

    1980-01-01

    A model for the distribution of tobacco strands in a cigarette is proposed to explain the discrepancy between density as measured by weight and volume and that as measured by β-ray attenuation and to explain the large deviation of the β-ray measurements from the mean value. The parameters which contribute to this uncertainty are slope of the β-ray attenuation curve, the mean path length through the mass element, and the material volume fraction. (author)

  6. Dual energy quantitative computed tomography (QCT). Precision of the mineral density measurements

    International Nuclear Information System (INIS)

    Braillon, P.; Bochu, M.

    1989-01-01

    The improvement that could be obtained in quantitative bone mineral measurements by dual energy computed tomography was tested in vitro. From the results of 15 mineral density measurements (in mg Ca/cm 3 , done on a precise lumbar spine phantom (Hologic) and referred to the values obtained on the same slices on a Siemens Osteo-CT phantom, the precision found was 0.8%, six times better than the precision calculated from the uncorrected measured values [fr

  7. Feasibility of repetitive lung function measurements by raised volume rapid thoracoabdominal compression during methacholine challenge in young infants

    DEFF Research Database (Denmark)

    Loland, L.; Bisgaard, H.

    2008-01-01

    BACKGROUND: The aim of the study was to evaluate the feasibility of lung function measurements by the raised volume rapid thoracoabdominal compression (RVRTC) technique during bronchial methacholine challenge in young infants. METHOD: Four hundred two healthy infants were tested at 1 month of age....... The mean acceptability rating among parents was 8 on a scale from 1 to 10, with 13% rating test, with the actual lung function testing accounting for half the time. CONCLUSION: This very comprehensive experience with standardized measurements of lung...... was successfully measured in 87% by transcutaneous oxygen pressure. No serious adverse events were observed during testing or after discharge from the clinic. The methacholine dose range was appropriate as PD could be determined in the majority of infants. FEV(0.5) values in 21% of infants dropped > 40% during...

  8. Electron density measurement of a colliding plasma using soft x-ray laser interferometry

    International Nuclear Information System (INIS)

    Wan, A.S.; Back, C.A.; Barbee, T.W.Jr.; Cauble, R.; Celliers, P.; DaSilva, L.B.; Glenzer, S.; Moreno, J.C.; Rambo, P.W.; Stone, G.F.; Trebes, J.E.; Weber, F.

    1996-05-01

    The understanding of the collision and subsequent interaction of counter-streaming high-density plasmas is important for the design of indirectly-driven inertial confinement fusion (ICF) hohlraums. We have employed a soft x-ray Mach-Zehnder interferometer, using a Ne- like Y x-ray laser at 155 angstrom as the probe source, to study interpenetration and stagnation of two colliding plasmas. We observed a peaked density profile at the symmetry axis with a wide stagnation region with width of order 100 μm. We compare the measured density profile with density profiles calculated by the radiation hydrodynamic code LASNEX and a multi-specie fluid code which allows for interpenetration. The measured density profile falls in between the calculated profiles using collisionless and fluid approximations. By using different target materials and irradiation configurations, we can vary the collisionality of the plasma. We hope to use the soft x-ray laser interferometry as a mechanism to validate and benchmark our numerical codes used for the design and analysis of high-energy- density physics experiments

  9. Interpretation of fast measurements of plasma potential, temperature and density in SOL of ASDEX Upgrade

    DEFF Research Database (Denmark)

    Horacek, J.; Adamek, J.; Müller, H.W.

    2010-01-01

    This paper focuses on interpretation of fast (1 µs) and local (2–4 mm) measurements of plasma density, potential and electron temperature in the edge plasma of tokamak ASDEX Upgrade. Steady-state radial profiles demonstrate the credibility of the ball-pen probe. We demonstrate that floating...... potential fluctuations measured by a Langmuir probe are dominated by plasma electron temperature rather than potential. Spatial and temporal scales are found consistent with expectations based on interchange-driven turbulence. Conditionally averaged signals found for both potential and density are also...

  10. Measuring neutron flux density in near-vessel space of a commercial WWER-1000 reactor

    International Nuclear Information System (INIS)

    Borodkin, G.I.; Eremin, A.N.; Lomakin, S.S.; Morozov, A.G.

    1987-01-01

    Distribution of neutron flux density in two experimental channels on the reactor vessel external surface and in ionization chamber channel of a commercial WWER-1000 reactor, is measured by the activation detector technique. Azimuthal distributions of fast and thermal neutron fluxes and height distributions of fast neutron flux density within energy range >1.2 and 2.3 MeV are obtained. Conclusion is made, that reactor core state and its structural peculiarities in the measurement range essentially affect space and energy distribution of neutron field near the vessel. It should be taken into account when determining permissible neutron fluence for the reactor vessel

  11. Quantitative density measurements from a real-time neutron radiography system

    International Nuclear Information System (INIS)

    McRae, D.D.; Jenkins, R.W. Jr.; Brenizer, J.S.; Tobin, K.W.; Hosticka, B.; Sulcoski, M.F.

    1986-01-01

    An advanced video system has been assembled from commercially available equipment to support the real-time neutron radiography facility established jointly by the University of Virginia Department of Nuclear Engineering and Engineering Physics, and the Philip Morris Research Center. A schematic diagram of the equipment used for real-time neutron radiography is presented. To obtain quantitative density measurements with this system, several modifications of both hardware and image processing software were required. After implementation of these changes, the system was capable of determining material densities by measuring the degree of neutron attenuation

  12. High-pressure density measurements for the binary system ethanol plus heptane

    DEFF Research Database (Denmark)

    Watson, G.; Zeberg-Mikkelsen, Claus Kjær; Baylaucq, A.

    2006-01-01

    The density of the asymmetrical binary system composed of ethanol and heptane has been measured (630 points) for nine different compositions including the pure compounds at five temperatures in the range (293.15 to 333.15) K and 14 isobars up to 65 MPa with a vibrating-tube densimeter, The experi......The density of the asymmetrical binary system composed of ethanol and heptane has been measured (630 points) for nine different compositions including the pure compounds at five temperatures in the range (293.15 to 333.15) K and 14 isobars up to 65 MPa with a vibrating-tube densimeter...

  13. Comparison of measured and modelled negative hydrogen ion densities at the ECR-discharge HOMER

    Energy Technology Data Exchange (ETDEWEB)

    Rauner, D.; Kurutz, U.; Fantz, U. [Max-Planck-Institut für Plasmaphysik, Boltzmannstr. 2, 85748 Garching (Germany); AG Experimentelle Plasmaphysik, Universität Augsburg, 86135 Augsburg (Germany)

    2015-04-08

    As the negative hydrogen ion density n{sub H{sup −}} is a key parameter for the investigation of negative ion sources, its diagnostic quantification is essential in source development and operation as well as for fundamental research. By utilizing the photodetachment process of negative ions, generally two different diagnostic methods can be applied: via laser photodetachment, the density of negative ions is measured locally, but only relatively to the electron density. To obtain absolute densities, the electron density has to be measured additionally, which induces further uncertainties. Via cavity ring-down spectroscopy (CRDS), the absolute density of H{sup −} is measured directly, however LOS-averaged over the plasma length. At the ECR-discharge HOMER, where H{sup −} is produced in the plasma volume, laser photodetachment is applied as the standard method to measure n{sub H{sup −}}. The additional application of CRDS provides the possibility to directly obtain absolute values of n{sub H{sup −}}, thereby successfully bench-marking the laser photodetachment system as both diagnostics are in good agreement. In the investigated pressure range from 0.3 to 3 Pa, the measured negative hydrogen ion density shows a maximum at 1 to 1.5 Pa and an approximately linear response to increasing input microwave powers from 200 up to 500 W. Additionally, the volume production of negative ions is 0-dimensionally modelled by balancing H{sup −} production and destruction processes. The modelled densities are adapted to the absolute measurements of n{sub H{sup −}} via CRDS, allowing to identify collisions of H{sup −} with hydrogen atoms (associative and non-associative detachment) to be the dominant loss process of H{sup −} in the plasma volume at HOMER. Furthermore, the characteristic peak of n{sub H{sup −}} observed at 1 to 1.5 Pa is identified to be caused by a comparable behaviour of the electron density with varying pressure, as n{sub e} determines

  14. Advanced density profile reflectometry; the state-of-the-art and measurement prospects for ITER

    Science.gov (United States)

    Doyle, E. J.

    2006-10-01

    Dramatic progress in millimeter-wave technology has allowed the realization of a key goal for ITER diagnostics, the routine measurement of the plasma density profile from millimeter-wave radar (reflectometry) measurements. In reflectometry, the measured round-trip group delay of a probe beam reflected from a plasma cutoff is used to infer the density distribution in the plasma. Reflectometer systems implemented by UCLA on a number of devices employ frequency-modulated continuous-wave (FM-CW), ultrawide-bandwidth, high-resolution radar systems. One such system on DIII-D has routinely demonstrated measurements of the density profile over a range of electron density of 0-6.4x10^19,m-3, with ˜25 μs time and ˜4 mm radial resolution, meeting key ITER requirements. This progress in performance was made possible by multiple advances in the areas of millimeter-wave technology, novel measurement techniques, and improved understanding, including: (i) fast sweep, solid-state, wide bandwidth sources and power amplifiers, (ii) dual polarization measurements to expand the density range, (iii) adaptive radar-based data analysis with parallel processing on a Unix cluster, (iv) high memory depth data acquisition, and (v) advances in full wave code modeling. The benefits of advanced system performance will be illustrated using measurements from a wide range of phenomena, including ELM and fast-ion driven mode dynamics, L-H transition studies and plasma-wall interaction. The measurement capabilities demonstrated by these systems provide a design basis for the development of the main ITER profile reflectometer system. This talk will explore the extent to which these reflectometer system designs, results and experience can be translated to ITER, and will identify what new studies and experimental tests are essential.

  15. Correcting the error in neutron moisture probe measurements caused by a water density gradient

    International Nuclear Information System (INIS)

    Wilson, D.J.

    1988-01-01

    If a neutron probe lies in or near a water density gradient, the probe may register a water density different to that at the measuring point. The effect of a thin stratum of soil containing an excess or depletion of water at various distances from a probe in an otherwise homogeneous system has been calculated, producing an 'importance' curve. The effect of these strata can be integrated over the soil region in close proximity to the probe resulting in the net effect of the presence of a water density gradient. In practice, the probe is scanned through the point of interest and the count rate at that point is corrected for the influence of the water density on each side of it. An example shows that the technique can reduce an error of 10 per cent to about 2 per cent

  16. Dual energy X-ray absorptiometry for the measurement of bone mineral density in Shanghai residents

    International Nuclear Information System (INIS)

    Zhang Yuanxun; Li Deyi; Ma Jixiao; Huang Qiren

    1996-01-01

    In recent years, the rapid development of bone mineral density determination technique provides a powerful research tool to diagnose osteoporosis and prevent fracture. Since the beginning of 1995, the research group incooperation with Shanghai 6th people's hospital is carrying on bone density measurements as a part of Co-ordinated Research Programme (CRP) organized by International Atomic Energy Agency (IAEA). The purpose of this study is to determine the age of peak bone mass in each study group of Shanghai residents and to quantify differences in bone density as functions of the age and sex of persons in the study groups. At the same time the authors should get the normal human BMD (Bone Mineral Density) reference database specially for Shanghai residents, China. The roles of various life styles, exercise, diet and so on are also investigated

  17. Density of Jatropha curcas Seed Oil and its Methyl Esters: Measurement and Estimations

    Science.gov (United States)

    Veny, Harumi; Baroutian, Saeid; Aroua, Mohamed Kheireddine; Hasan, Masitah; Raman, Abdul Aziz; Sulaiman, Nik Meriam Nik

    2009-04-01

    Density data as a function of temperature have been measured for Jatropha curcas seed oil, as well as biodiesel jatropha methyl esters at temperatures from above their melting points to 90 ° C. The data obtained were used to validate the method proposed by Spencer and Danner using a modified Rackett equation. The experimental and estimated density values using the modified Rackett equation gave almost identical values with average absolute percent deviations less than 0.03% for the jatropha oil and 0.04% for the jatropha methyl esters. The Janarthanan empirical equation was also employed to predict jatropha biodiesel densities. This equation performed equally well with average absolute percent deviations within 0.05%. Two simple linear equations for densities of jatropha oil and its methyl esters are also proposed in this study.

  18. Precise measurement of the densities of liquid Bi, Sn, Pb and Sb

    International Nuclear Information System (INIS)

    Wang Lianwen; Wang Qiang; Xian Aiping; Lu Kunquan

    2003-01-01

    The densities of liquid Bi, Sn, Pb and Sb have been precisely measured from the melting point up to about 1100 K using an improved Archimedean method. The densities at the melting point for liquid Bi, Sn, Pb and Sb are 10.042 x 10 3 , 6.983 x 10 3 , 10.635 x 10 3 and 6.454 x 10 3 kg m -3 , respectively. Comparisons between our data and those from the literature have been made and they show the present results to be more reliable. Rather than a linear fit for the temperature dependence of the density, a slight deviation from linearity in the temperature dependence of the densities has been observed

  19. Measuring irradiated lung and heart area in breast tangential fields using a simulator-based computerized tomography device

    Energy Technology Data Exchange (ETDEWEB)

    Mallik, Raj; Fowler, Allan; Hunt, Peter

    1995-01-15

    Purpose: To illustrate the use of a simulator based computerized tomography system (SIMCT) in the simulation and planning of tangential breast fields. Methods and Materials: Forty-five consecutive patients underwent treatment planning using a radiotherapy simulator with computerized tomography attachment. One to three scans were obtained for each patient, calculations were made on the central axis scan. Due to the wide aperture of this system all patients were able to be scanned in the desired treatment position with arm abducted 90 deg. . Using available software tools the area of lung and/or heart included within the tangential fields was calculated. The greatest perpendicular distance (GPD) from the chest wall to posterior field edge was also measured. Results: The mean GPD for the group was 25.40 mm with 71% of patients having GPDs of {<=} 30 mm. The mean area of irradiated lung was 1780 sq mm which represented 18.0% of the total ipsilateral lung area seen in the central axis. Seven of the patients with left sided tumors had an average 1314 sq mm heart irradiated in the central axis. This represented 11.9% of total heart area in these patients. Conclusion: Measurements of irradiated lung and heart area can be easily and accurately made using a SIMCT device. Such measurements may help identify those patients potentially at risk for lung or heart toxicity as a consequence of their treatment. A major advantage of this device is the ability to scan patients in the actual treatment position.

  20. Measuring irradiated lung and heart area in breast tangential fields using a simulator-based computerized tomography device

    International Nuclear Information System (INIS)

    Mallik, Raj; Fowler, Allan; Hunt, Peter

    1995-01-01

    Purpose: To illustrate the use of a simulator based computerized tomography system (SIMCT) in the simulation and planning of tangential breast fields. Methods and Materials: Forty-five consecutive patients underwent treatment planning using a radiotherapy simulator with computerized tomography attachment. One to three scans were obtained for each patient, calculations were made on the central axis scan. Due to the wide aperture of this system all patients were able to be scanned in the desired treatment position with arm abducted 90 deg. . Using available software tools the area of lung and/or heart included within the tangential fields was calculated. The greatest perpendicular distance (GPD) from the chest wall to posterior field edge was also measured. Results: The mean GPD for the group was 25.40 mm with 71% of patients having GPDs of ≤ 30 mm. The mean area of irradiated lung was 1780 sq mm which represented 18.0% of the total ipsilateral lung area seen in the central axis. Seven of the patients with left sided tumors had an average 1314 sq mm heart irradiated in the central axis. This represented 11.9% of total heart area in these patients. Conclusion: Measurements of irradiated lung and heart area can be easily and accurately made using a SIMCT device. Such measurements may help identify those patients potentially at risk for lung or heart toxicity as a consequence of their treatment. A major advantage of this device is the ability to scan patients in the actual treatment position

  1. Measurements with the PNNL Density Sensor aboard the Essayons, July 2009

    International Nuclear Information System (INIS)

    Greenwood, Margaret S.

    2009-01-01

    Report of the measurements and analysis of the density data. On July 9, 2009, the Pacific Northwest National Laboratory (PNNL) ultrasonic sensor obtained density data for the sand slurry dredged near the mouth of the Columbia River by the Essayons. The objective of these measurements was to compare the data from the ultrasonic sensor with that obtained by the radioactive sensor, currently in use. The U. S. Corps of Engineers is interested in a sensor technology capable of competing with the radioactive sensor to ease regulatory concerns. The average density obtained during the data acquisition was smaller than the expected value of 1.3 g/cm3. Further investigation showed that the radioactive sensor measured a density of 1.11 g/cm3 for the calibration liquid, but the code was set up with the density of seawater of 1.025 g/cm3. This mismatch partially explained the low density value. However, the conclusion was that, while the basic data is very good, the current interpretation of that data needed modification. A new model has been developed that describes how the ultrasound interacts with the sand particles in the slurry. The new model requires the evaluation of a constant ksurf from a laboratory experiment. This was carried out at PNNL using sand obtained from the Oregon coast during a previous visit to the Essayons. A value for ksurf was determined with an error of ±10%, which, of course, is too large. For future work, another design is proposed and a more accurate value is expected. Measurements with the refractometer showed the effects of tides. That is, in the morning the density of the seawater was very close to that for fresh water, while in the afternoon, the density was due to salt water. The results of the analysis showed that the average density of the sand slurry varies between 1.230 and 1.235 g/cm3. The last section of this report discusses in detail improvements for future development. The conclusion is that, once these improvements have been made

  2. Dose profile measurements during respiratory-gated lung stereotactic radiotherapy: A phantom study

    International Nuclear Information System (INIS)

    Jong, W L; Ung, N M; Wong, J H D; Ng, K H

    2016-01-01

    During stereotactic body radiotherapy, high radiation dose (∼60 Gy) is delivered to the tumour in small fractionation regime. In this study, the dosimetric characteristics were studied using radiochromic film during respiratory-gated and non-gated lung stereotactic body radiotherapy (SBRT). Specifically, the effect of respiratory cycle and amplitude, as well as gating window on the dosimetry were studied. In this study, the dose profiles along the irradiated area were measured. The dose profiles for respiratory-gated radiation delivery with different respiratory or tumour motion amplitudes, gating windows and respiratory time per cycle were in agreement with static radiation delivery. The respiratory gating system was able to deliver the radiation dose accurately (±1.05 mm) in the longitudinal direction. Although the treatment time for respiratory-gated SBRT was prolonged, this approach can potentially reduce the margin for internal tumour volume without compromising the tumour coverage. In addition, the normal tissue sparing effect can be improved. (paper)

  3. Power spectral density measurements with 252Cf for a light water moderated research reactor

    International Nuclear Information System (INIS)

    King, W.T.; Mihalczo, J.T.

    1979-01-01

    A method of determining the reactivity of far subcritical systems from neutron noise power spectral density measurements with 252 Cf has previously been tested in fast reactor critical assemblies: a mockup of the Fast Flux Test Facility reactor and a uranium metal sphere. Calculations indicated that this measurement was feasible for a pressurized water reactor (PWR). In order to evaluate the ability to perform these measurements with moderated reactors which have long prompt neutron lifetimes, measurements were performed with a small plate-type research reactor whose neutron lifetime (57 microseconds) was about a factor of three longer than that of a PWR and approx. 50% longer than that of a boiling water reactor. The results of the first measurements of power spectral densities with 252 Cf for a water moderated reactor are presented

  4. Measurements of density, temperature, and their fluctuations in turbulent supersonic flow using UV laser spectroscopy

    Science.gov (United States)

    Fletcher, Douglas G.; Mckenzie, R. L.

    1992-01-01

    Nonintrusive measurements of density, temperature, and their turbulent fluctuation levels were obtained in the boundary layer of an unseeded, Mach 2 wind tunnel flow. The spectroscopic technique that was used to make the measurements is based on the combination of laser-induced oxygen fluorescence and Raman scattering by oxygen and nitrogen from the same laser pulse. Results from this demonstration experiment are compared with previous measurements obtained in the same facility using conventional probes and an earlier spectroscopic technique. Densities and temperatures measured with the current technique agree with the previous surveys to within 3 percent and 2 percent, respectively. The fluctuation amplitudes for both variables agree with the measurements obtained using the earlier spectroscopic technique and show evidence of an unsteady, weak shock wave that perturbs the boundary layer.

  5. Poor sleep quality has an adverse effect on childhood asthma control and lung function measures.

    Science.gov (United States)

    Sheen, Youn Ho; Choi, Sun Hee; Jang, Sun Jung; Baek, Ji Hyeon; Jee, Hye Mi; Kim, Mi Ae; Chae, Kyu Young; Han, Man Yong

    2017-08-01

    It is unclear as to whether sleep respiratory breathing disorder (SRBD) is a risk factor for uncontrolled asthma in children. The aim of this study was therefore to investigate whether SRBD may have an adverse effect on childhood asthma control and lung function measures. This was a cross-sectional study of 220 children with well-controlled (n = 108), partly controlled (n = 92), and uncontrolled asthma (n = 20) according to the Global Initiative for Asthma guideline. SRBD was assessed using the Pediatric Sleep Questionnaire (PSQ). The association of SRBD with partly controlled/uncontrolled asthma was investigated on multivariate logistic regression analysis. Of 220 children with asthma, 43 (19.6%) had SRBD: well-controlled, 16.7% (18/108); partly controlled, 21.7% (20/92); and uncontrolled, 25.0% (5/20; P = 0.54). There was a significant difference in forced expiratory volume in 1 s/forced vital capacity (FEV 1 /FVC; P = 0.007) and childhood asthma control test (C-ACT) score (P asthma control status, but not in PSQ score (P = 0.18). Children with obstructive sleep apnea (PSQ >0.33) had a lower C-ACT score compared with controls (PSQ ≤0.33; 19.6 ± 5.1 vs 22.0 ± 4.2, P = 0.002). PSQ score was negatively correlated with FEV 1 /FVC (r = -0.16, P = 0.02). On multivariate logistic regression analysis, high PSQ score increased the odds of having partly controlled/uncontrolled asthma by 9.12 (95% CI: 1.04-79.72, P = 0.046) after adjusting for confounding factors. SRBD is an independent risk factor for partly controlled/uncontrolled asthma and has an adverse effect on lung function measures in children. Further research is warranted to determine whether the improvement of sleep quality may also enhance level of asthma control and lung function in children. © 2017 Japan Pediatric Society.

  6. Systematic comparison between line integrated densities measured with interferometry and polarimetry at JET

    International Nuclear Information System (INIS)

    Brombin, M.; Zilli, E.; Giudicotti, L.; Boboc, A.; Murari, A.

    2009-01-01

    A systematic comparison between the line integrated electron density derived from interferometry and polarimetry at JET has been carried out. For the first time the reliability of the measurements of the Cotton-Mouton effect has been analyzed for a wide range of main plasma parameters and the possibility to evaluate the electron density directly from polarimetric data has been studied. The purpose of this work is to recover the interferometric data with the density derived from the measured Cotton-Mouton effect, when the fringe jump phenomena occur. The results show that the difference between the line integrated electron density from interferometry and polarimetry is with one fringe (1.143x10 19 m -2 ) for more than 90% of the cases. It is possible to consider polarimetry as a satisfactory alternative method to interferometry to measure the electron density and it could be used to recover interferometric signal when a fringe jumps occurs, preventing difficulties for the real-time control of many experiments at the JET machine.

  7. Measuring Density Profiles of Electrons and Heavy Particles in a Stable Axially Blown Arc

    Science.gov (United States)

    Carstensen, J.; Stoller, P.; Galletti, B.; Doiron, C. B.; Sokolov, A.

    2017-08-01

    Two-color spatial carrier wave interferometry employing pulsed 532- and 671-nm lasers is used to measure the electron-density and heavy-particle-density profiles in the stagnation point of a stable, axially blown arc in argon for currents of 50 to 200 A and stagnation point pressures of 0.2 to 16 bar. This technique takes advantage of the fact that the free-electron contribution to the refractive index depends strongly on the wavelength, while that of the heavy particles does not. The high spatial resolution achieved allows the hot core of the arc to be readily distinguished from the surrounding boundary layer. A custom-built test device is used to ensure flow conditions that lead to a stable, axisymmetric arc; this permits the reconstruction of the density and temperature profiles using a single projection (interferometric image) of the refractive-index distribution through the arc (at two wavelengths). The arc radius determined from the heavy-particle density decreases with increasing stagnation pressure and increases with the current. These measurements are in good agreement with a simple axially blown arc model taking into account Ohmic heating, radiation losses, and enthalpy flow for core temperatures of approximately 16 500 K. The measured electron density at the center of the arc agrees well with a prediction based on local thermodynamic equilibrium.

  8. Two-Dimensional Electron Density Measurement of Positive Streamer Discharge in Atmospheric-Pressure Air

    Science.gov (United States)

    Inada, Yuki; Ono, Ryo; Kumada, Akiko; Hidaka, Kunihiko; Maeyama, Mitsuaki

    2016-09-01

    The electron density of streamer discharges propagating in atmospheric-pressure air is crucially important for systematic understanding of the production mechanisms of reactive species utilized in wide ranging applications such as medical treatment, plasma-assisted ignition and combustion, ozone production and environmental pollutant processing. However, electron density measurement during the propagation of the atmospheric-pressure streamers is extremely difficult by using the conventional localized type measurement systems due to the streamer initiation jitters and the irreproducibility in the discharge paths. In order to overcome the difficulties, single-shot two-dimensional electron density measurement was conducted by using a Shack-Hartmann type laser wavefront sensor. The Shack-Hartmann sensor with a temporal resolution of 2 ns was applied to pulsed positive streamer discharges generated in an air gap between pin-to-plate electrodes. The electron density a few ns after the streamer initiation was 7*1021m-3 and uniformly distributed along the streamer channel. The electron density and its distribution profile were compared with a previous study simulating similar streamers, demonstrating good agreement. This work was supported in part by JKA and its promotion funds from KEIRIN RACE. The authors like to thank Mr. Kazuaki Ogura and Mr. Kaiho Aono of The University of Tokyo for their support during this work.

  9. Novel analysis technique for measuring edge density fluctuation profiles with reflectometry in the Large Helical Device

    Science.gov (United States)

    Creely, A. J.; Ida, K.; Yoshinuma, M.; Tokuzawa, T.; Tsujimura, T.; Akiyama, T.; Sakamoto, R.; Emoto, M.; Tanaka, K.; Michael, C. A.

    2017-07-01

    A new method for measuring density fluctuation profiles near the edge of plasmas in the Large Helical Device (LHD) has been developed utilizing reflectometry combined with pellet-induced fast density scans. Reflectometer cutoff location was calculated by proportionally scaling the cutoff location calculated with fast far infrared laser interferometer (FIR) density profiles to match the slower time resolution results of the ray-tracing code LHD-GAUSS. Plasma velocity profile peaks generated with this reflectometer mapping were checked against velocity measurements made with charge exchange spectroscopy (CXS) and were found to agree within experimental uncertainty once diagnostic differences were accounted for. Measured density fluctuation profiles were found to peak strongly near the edge of the plasma, as is the case in most tokamaks. These measurements can be used in the future to inform inversion methods of phase contrast imaging (PCI) measurements. This result was confirmed with both a fixed frequency reflectometer and calibrated data from a multi-frequency comb reflectometer, and this method was applied successfully to a series of discharges. The full width at half maximum of the turbulence layer near the edge of the plasma was found to be only 1.5-3 cm on a series of LHD discharges, less than 5% of the normalized minor radius.

  10. The measurements of plasma cytokines in radiation-induced pneumonitis in lung cancer patients

    International Nuclear Information System (INIS)

    Hur, Won Joo; Youn, Seon Min; Lee, Hyung Sik; Yang, Kwang Mo; Sin, Geun Ho; Son, Choon Hee; Han, Jin Yeong; Lee, Ki Nam; Jeong, Min Ho

    2000-01-01

    To investigate whether changes in plasma concentrations of transforming growth factor-β 1(TGF-β 1), tumor necrosis factor-alpha (TNF-α) and interleukin-6 (lL -6) could be used to identify the development of radiation-induced pneumonitis in the lung cancer patients. Seventeen patients with lung cancer (11 NSCLC. 6 SCLC) were enrolled in a prospective study designed to evaluate clinical and molecular biologic correlation of radiation-induced pneumonitis. The study began in May 1998 and completed in July 1999. All patients were treated with radiotherapy with curative intent: 1.8 Gy per day, 5 fractions per week. Serial measurements of plasma TGF-β1, TNF--α and IL -6 were obtained in all patients before, weekly during radiotherapy and at each follow-up visits after completion of treatment. These measurements were quantified using enzyme linked immunosorbent assay (ELISA). All patients were evaluated for signs and symptoms of pneumonitis at each follow-up visits after completion of radiotherapy. High resolution CT (HRCT) scans were obtained when signs and symptoms of pneumonitis were developed after completion of radiotherapy. Thirteen patients eventually developed signs and symptoms of clinical pneumonitis while four patients did not. TGF- P 1 levels were elevated in - all 13 patients with pneumonitis, which showed characteristic pattern of elevation (38.45 ng/ml at pretreatment, 13.66 ng/ml during radiotherapy, then 60.63 ng/ml at 2-4 weeks after completion of radiotherapy). The levels of TNF--α and IL -6 were also elevated in the group of patients who developed pneumonitis but the pattern was not characteristic. Changes in plasma TGFβ-1 levels before, during and after radiotherapy appears to be a useful means by which to identify patients at risk for the development of symptomatic pneumonitis. Other cytokines like TNF--α and IL-6 shows no meaningful changes in association with radiation pneumonitis

  11. A comparison of five methods of measuring mammographic density: a case-control study.

    Science.gov (United States)

    Astley, Susan M; Harkness, Elaine F; Sergeant, Jamie C; Warwick, Jane; Stavrinos, Paula; Warren, Ruth; Wilson, Mary; Beetles, Ursula; Gadde, Soujanya; Lim, Yit; Jain, Anil; Bundred, Sara; Barr, Nicola; Reece, Valerie; Brentnall, Adam R; Cuzick, Jack; Howell, Tony; Evans, D Gareth

    2018-02-05

    High mammographic density is associated with both risk of cancers being missed at mammography, and increased risk of developing breast cancer. Stratification of breast cancer prevention and screening requires mammographic density measures predictive of cancer. This study compares five mammographic density measures to determine the association with subsequent diagnosis of breast cancer and the presence of breast cancer at screening. Women participating in the "Predicting Risk Of Cancer At Screening" (PROCAS) study, a study of cancer risk, completed questionnaires to provide personal information to enable computation of the Tyrer-Cuzick risk score. Mammographic density was assessed by visual analogue scale (VAS), thresholding (Cumulus) and fully-automated methods (Densitas, Quantra, Volpara) in contralateral breasts of 366 women with unilateral breast cancer (cases) detected at screening on entry to the study (Cumulus 311/366) and in 338 women with cancer detected subsequently. Three controls per case were matched using age, body mass index category, hormone replacement therapy use and menopausal status. Odds ratios (OR) between the highest and lowest quintile, based on the density distribution in controls, for each density measure were estimated by conditional logistic regression, adjusting for classic risk factors. The strongest predictor of screen-detected cancer at study entry was VAS, OR 4.37 (95% CI 2.72-7.03) in the highest vs lowest quintile of percent density after adjustment for classical risk factors. Volpara, Densitas and Cumulus gave ORs for the highest vs lowest quintile of 2.42 (95% CI 1.56-3.78), 2.17 (95% CI 1.41-3.33) and 2.12 (95% CI 1.30-3.45), respectively. Quantra was not significantly associated with breast cancer (OR 1.02, 95% CI 0.67-1.54). Similar results were found for subsequent cancers, with ORs of 4.48 (95% CI 2.79-7.18), 2.87 (95% CI 1.77-4.64) and 2.34 (95% CI 1.50-3.68) in highest vs lowest quintiles of VAS, Volpara and Densitas

  12. Analysis of factors causing signal loss in the measurement of lung tissue water by nuclear magnetic resonance

    International Nuclear Information System (INIS)

    Fukuzaki, Minoru; Shioya, Sumie; Haida, Munetaka

    1997-01-01

    The water content of lung, brain, and muscle tissue was measured by nuclear magnetic resonance (NMR) and compared with gravimetric determinations. The NMR signal intensity of water was measured by a single 90 degree pulse and by a spin-echo sequence. The absolute water content was determined by the difference in the sample's weight before and after desiccation. The NMR detectable water in each tissue was expressed as a percentage of the signal intensity for an equal weight of distilled water. Using the single pulse measurement, 67% of the gravimetrically-measured water was detected in collapsed lung samples (consisting of about 47% retained air), in contrast to 96% for brain and 98% for muscle. For degassed lung samples, the NMR detectability of water increased to 87% with the single pulse measurement and to 90% with the spin-echo measurement, but the values remained significantly less than those of brain or muscle. Factors that caused the NMR signal loss of 33% in collapsed lung samples were: air-tissue interfaces (20%), microscopic field inhomogeneity (3%), and a water component with an extremely short magnetization decay time constant (10%). (author)

  13. Longitudinal micro-CT as an outcome measure of interstitial lung disease in TNF-transgenic mice.

    Directory of Open Access Journals (Sweden)

    Richard D Bell

    Full Text Available Rheumatoid arthritis associated interstitial lung disease (RA-ILD is a debilitating condition with poor survival prognosis. High resolution computed tomography (CT is a common clinical tool to diagnose RA-ILD, and is increasingly being adopted in pre-clinical studies. However, murine models recapitulating RA-ILD are lacking, and CT outcomes for inflammatory lung disease have yet to be formally validated. To address this, we validate μCT outcomes for ILD in the tumor necrosis factor transgenic (TNF-Tg mouse model of RA.Cross sectional μCT was performed on cohorts of male TNF-Tg mice and their WT littermates at 3, 4, 5.5 and 12 months of age (n = 4-6. Lung μCT outcomes measures were determined by segmentation of the μCT datasets to generate Aerated and Tissue volumes. After each scan, lungs were obtained for histopathology and 3 sections stained with hematoxylin and eosin. Automated histomorphometry was performed to quantify the tissue area (nuclei, cytoplasm, and extracellular matrix and aerated area (white space within the tissue sections. Spearman's correlation coefficients were used to evaluate the extent of association between μCT imaging and histopathology endpoints.TNF-Tg mice had significantly greater tissue volume, total lung volume and mean intensity at all timepoints compared to age matched WT littermates. Histomorphometry also demonstrated a significant increase in tissue area at 3, 4, and 5.5 months of age in TNF-Tg mice. Lung tissue volume was correlated with lung tissue area (ρ = 0.81, p<0.0001, and normalize lung aerated volume was correlated with normalized lung air area (ρ = 0.73, p<0.0001.We have validated in vivo μCT as a quantitative biomarker of ILD in mice. Further, development of longitudinal measures is critical for dissecting pathologic progression of ILD, and μCT is a useful non-invasive method to study lung inflammation in the TNF-Tg mouse model.

  14. Electron density measurement in gas discharge plasmas by optical and acoustic methods

    International Nuclear Information System (INIS)

    Biagioni, A.; Anania, M.P.; Bellaveglia, M.; Chiadroni, E.; Giovenale, D. Di; Pirro, G. Di; Ferrario, M.; Pompili, R.; Shpakov, V.; Vaccarezza, C.; Villa, F.; Cianchi, A.; Filippi, F.; Mostacci, A.; Zigler, A.

    2016-01-01

    Plasma density represents a very important parameter for both laser wakefield and plasma wakefield acceleration, which use a gas-filled capillary plasma source. Several techniques can be used to measure the plasma density within a capillary discharge, which are mainly based on optical diagnostic methods, as for example the well-known spectroscopic method using the Stark broadening effect. In this work, we introduce a preliminary study on an alternative way to detect the plasma density, based on the shock waves produced by gas discharge in a capillary. Firstly, the measurements of the acoustic spectral content relative to the laser-induced plasmas by a solid target allowed us to understand the main properties of the acoustic waves produced during this kind of plasma generation; afterwards, we have extended such acoustic technique to the capillary plasma source in order to calibrate it by comparison with the stark broadening method.

  15. Body composition and bone mineral density measurements by using a multi-energy method

    International Nuclear Information System (INIS)

    Herve, L.

    2003-01-01

    Dual-energy X-ray absorptiometry is a major technique to evaluate bone mineral density, thus allowing diagnosis of bone decalcification ( osteoporosis). Recently, this method has proved useful to quantify body composition (fat ratio). However, these measurements suffer from artefacts which can lead to diagnosis errors in a number of cases. This work has aimed to improve both the reproducibility and the accuracy of bone mineral density and body composition measurements. To this avail, the acquisition conditions were optimised in order to ameliorate the results reproducibility and we have proposed a new method to correct inaccuracies in the determination of bone mineral density. Experimental validations yield encouraging results on both synthetic phantoms and biological samples. (author)

  16. Electron cloud density measurements in accelerator beam-pipe using resonant microwave excitation

    Energy Technology Data Exchange (ETDEWEB)

    Sikora, John P., E-mail: jps13@cornell.edu [CLASSE, Cornell University, Ithaca, NY 14853 (United States); Carlson, Benjamin T. [Carnegie Mellon University, Pittsburgh, PA 15213 (United States); Duggins, Danielle O. [Gordon College, Wenham, MA 01984 (United States); Hammond, Kenneth C. [Columbia University, New York, NY 10027 (United States); De Santis, Stefano [LBNL, Berkeley, CA 94720 (United States); Tencate, Alister J. [Idaho State University, Pocatello, ID 83209 (United States)

    2014-08-01

    An accelerator beam can generate low energy electrons in the beam-pipe, generally called electron cloud, that can produce instabilities in a positively charged beam. One method of measuring the electron cloud density is by coupling microwaves into and out of the beam-pipe and observing the response of the microwaves to the presence of the electron cloud. In the original technique, microwaves are transmitted through a section of beam-pipe and a change in EC density produces a change in the phase of the transmitted signal. This paper describes a variation on this technique in which the beam-pipe is resonantly excited with microwaves and the electron cloud density calculated from the change that it produces in the resonant frequency of the beam-pipe. The resonant technique has the advantage that measurements can be localized to sections of beam-pipe that are a meter or less in length with a greatly improved signal to noise ratio.

  17. Measuring the Density of a Molecular Cluster Injector via Visible Emission from an Electron Beam

    Energy Technology Data Exchange (ETDEWEB)

    Lundberg, D. P.; Kaita, R.; Majeski, R. M.; Stotler, D. P.

    2010-06-28

    A method to measure the density distribution of a dense hydrogen gas jet is pre- sented. A Mach 5.5 nozzle is cooled to 80K to form a flow capable of molecular cluster formation. A 250V, 10mA electron beam collides with the jet and produces Hα emission that is viewed by a fast camera. The high density of the jet, several 1016cm-3, results in substantial electron depletion, which attenuates the Hα emission. The attenuated emission measurement, combined with a simplified electron-molecule collision model, allows us to determine the molecular density profile via a simple iterative calculation.

  18. Radioisotope instrument for measuring the position of interface of two liquid media with similar density

    International Nuclear Information System (INIS)

    Afanas'ev, V.N.; Kolyada, A.N.; Krejndlin, I.I.; Pakhunkov, Yu.I.

    1977-01-01

    A gamma level indicator is developed for automatic and continuous remote measuring the location of the interface of two liquids with close densities in closed and open containers. The density of the upper (light) medium is 1.0-1.2 g/cm 3 . The instrument incorporates a transmitter-receiver unit, a relay regulator, a power amplifier and a secondary instrument. The operating principle of the level indicator is based on the detection of gamma-radiation scattered by a controlled medium; the alternations in gamma radiation flux serve to automatically set the transmitter-receiver unit on the interface of two media. The specially developed small transmitter-receiver with an Am 241 gamma radiation source is very sensible to little medium density changes and stable against perturbing factor action. The level indicator developed may be used to measure and regulate the level of liquid contacting with an air (gas) medium. The specifications of the instrument are presented

  19. Atomic Emission Spectra Diagnosis and Electron Density Measurement of Semiconductor Bridge (SCB) Plasma

    International Nuclear Information System (INIS)

    Feng Hongyan; Zhu Shunguan; Zhang Lin; Wan Xiaoxia; Li Yan; Shen Ruiqi

    2010-01-01

    Emission spectra of a semiconductor bridge (SCB) plasma in a visible range was studied in air. The electron density was measured in a conventional way from the broadening of the A1 I 394.4 nm Stark width. Based on the Saha equation, a system for recording the intensity of Si I 390.5 nm and Si II 413.1 nm was designed. With this technique, the SCB plasma electron density was measured well and accurately. Moreover, the electron density distribution Vs time was acquired from one SCB discharge. The individual result from the broadening of the Al I 394.4 nm Stark width and Saha equation was all in the range of 10 15 cm -3 to 10 16 cm -3 . Finally the presumption of the local thermodynamic equilibrium (LTE) condition was validated.

  20. Assessment of volume and leak measurements during CPAP using a neonatal lung model

    International Nuclear Information System (INIS)

    Fischer, H S; Roehr, C C; Proquitté, H; Wauer, R R; Schmalisch, G

    2008-01-01

    Although several commercial devices are available which allow tidal volume and air leak monitoring during continuous positive airway pressure (CPAP) in neonates, little is known about their measurement accuracy and about the influence of air leaks on volume measurement. The aim of this in vitro study was the validation of volume and leak measurement under CPAP using a commercial ventilatory device, taking into consideration the clinical conditions in neonatology. The measurement accuracy of the Leoni ventilator (Heinen and Löwenstein, Germany) was investigated both in a leak-free system and with leaks simulated using calibration syringes (2–10 ml, 20–100 ml) and a mechanical lung model. Open tubes of variable lengths were connected for leak simulation. Leak flow was measured with the flow-through technique. In a leak-free system the mean relative volume error ±SD was 3.5 ± 2.6% (2–10 ml) and 5.9 ± 0.7% (20–60 ml), respectively. The influence of CPAP level, driving flow, respiratory rate and humidification of the breathing gas on the volume error was negligible. However, an increasing F i O 2 caused the measured tidal volume to increase by up to 25% (F i O 2 = 1.0). The relative error ±SD of the leak measurements was −0.2 ± 11.9%. For leaks >19%, measured tidal volume was underestimated by more than 10%. In conclusion, the present in vitro study showed that the Leoni allowed accurate volume monitoring under CPAP conditions similar to neonates. Air leaks of up to 90% of patient flow were reliably detected. For an F i O 2 >0.4 and for leaks >19%, a numerical correction of the displayed volume should be performed

  1. Assessment of volume and leak measurements during CPAP using a neonatal lung model.

    Science.gov (United States)

    Fischer, H S; Roehr, C C; Proquitté, H; Wauer, R R; Schmalisch, G

    2008-01-01

    Although several commercial devices are available which allow tidal volume and air leak monitoring during continuous positive airway pressure (CPAP) in neonates, little is known about their measurement accuracy and about the influence of air leaks on volume measurement. The aim of this in vitro study was the validation of volume and leak measurement under CPAP using a commercial ventilatory device, taking into consideration the clinical conditions in neonatology. The measurement accuracy of the Leoni ventilator (Heinen & Löwenstein, Germany) was investigated both in a leak-free system and with leaks simulated using calibration syringes (2-10 ml, 20-100 ml) and a mechanical lung model. Open tubes of variable lengths were connected for leak simulation. Leak flow was measured with the flow-through technique. In a leak-free system the mean relative volume error +/-SD was 3.5 +/- 2.6% (2-10 ml) and 5.9 +/- 0.7% (20-60 ml), respectively. The influence of CPAP level, driving flow, respiratory rate and humidification of the breathing gas on the volume error was negligible. However, an increasing F(i)O(2) caused the measured tidal volume to increase by up to 25% (F(i)O(2) = 1.0). The relative error +/- SD of the leak measurements was -0.2 +/- 11.9%. For leaks > 19%, measured tidal volume was underestimated by more than 10%. In conclusion, the present in vitro study showed that the Leoni allowed accurate volume monitoring under CPAP conditions similar to neonates. Air leaks of up to 90% of patient flow were reliably detected. For an F(i)O(2) > 0.4 and for leaks > 19%, a numerical correction of the displayed volume should be performed.

  2. Comparison of neurite density measured by MRI and histology after TBI.

    Directory of Open Access Journals (Sweden)

    Shiyang Wang

    Full Text Available Functional recovery after brain injury in animals is improved by marrow stromal cells (MSC which stimulate neurite reorganization. However, MRI measurement of neurite density changes after injury has not been performed. In this study, we investigate the feasibility of MRI measurement of neurite density in an animal model of traumatic brain injury (TBI with and without MSC treatment.Fifteen male Wistar rats, were treated with saline (n = 6 or MSCs (n = 9 and were sacrificed at 6 weeks after controlled cortical impact (CCI. Healthy non-CCI rats (n = 5, were also employed. Ex-vivo MRI scans were performed two days after the rats were sacrificed. Multiple-shell hybrid diffusion imaging encoding scheme and spherical harmonic expansion of a two-compartment water diffusion displacement model were used to extract neurite related parameters. Bielshowski and Luxol Fast blue was used for staining axons and myelin, respectively. Modified Morris water maze and neurological severity score (mNSS test were performed for functional evaluation. The treatment effects, the correlations between neurite densities measured by MRI and histology, and the correlations between MRI and functional variables were calculated by repeated measures analysis of variance, the regression correlation analysis tests, and spearman correlation coefficients.Neurite densities exhibited a significant correlation (R(2>0.80, p<1E-20 between MRI and immuno-histochemistry measurements with 95% lower bound of the intra-correlation coefficient (ICC as 0.86. The conventional fractional anisotropy (FA correlated moderately with histological neurite density (R(2 = 0.59, P<1E-5 with 95% lower bound of ICC as 0.76. MRI data revealed increased neurite reorganization with MSC treatment compared with saline treatment, confirmed by histological data from the same animals. mNSS were significantly correlated with MRI neurite density in the hippocampus region.The present studies

  3. The effect of inspiration on airway dimensions measured in CT images from the Danish Lung Cancer Screening Trial

    DEFF Research Database (Denmark)

    Petersen, Jens; Wille, Mathilde; Thomsen, Laura

    2013-01-01

    of the same subject using image registration. Mixed effect models were used to predict the relative change in lumen diameter (LD) and wall thickness (WT) in airways of generation 0 (trachea) to 6 based on relative changes in the segmented total lung volume (TLV). Results: On average, 1.0, 2.0, 3.9, 7.6, 15...... and Materials: We selected from the Danish Lung Cancer Screening Trial 978 subjects without COPD who were scanned annually for 5 years with low-dose multi-slice CT. Using in-house developed software, the lungs and airways were automatically segmented and corresponding airway branches were found in all scans......Purpose: Airway dimensions measured from CT are increasingly being used to investigate diseases such as chronic obstructive pulmonary disease (COPD). In this study, we investigate the effect of differences in inspiration level on such measurements in voluntary inspiration breathhold scans. Methods...

  4. Molecular Rayleigh Scattering Diagnostic for Dynamic Temperature, Velocity, and Density Measurements

    Science.gov (United States)

    Mielke, Amy R.; Elam, Kristie A.; Sung, Chi-Jen

    2006-01-01

    A molecular Rayleigh scattering technique is developed to measure dynamic gas temperature, velocity, and density in unseeded turbulent flows at sampling rates up to 16 kHz. A high power CW laser beam is focused at a point in an air jet plume and Rayleigh scattered light is collected and spectrally resolved. The spectrum of the light, which contains information about the temperature and velocity of the flow, is analyzed using a Fabry-Perot interferometer. The circular interference fringe pattern is divided into four concentric regions and sampled at 1 and 16 kHz using photon counting electronics. Monitoring the relative change in intensity within each region allows for measurement of gas temperature and velocity. Independently monitoring the total scattered light intensity provides a measure of gas density. A low speed heated jet is used to validate the measurement of temperature fluctuations and an acoustically excited nozzle flow is studied to validate velocity fluctuation measurements. Power spectral density calculations of the property fluctuations, as well as mean and fluctuating quantities are presented. Temperature fluctuation results are compared with constant current anemometry measurements and velocity fluctuation results are compared with constant temperature anemometry measurements at the same locations.

  5. Proposed non-interferometric FIR electron density measuring scheme for Tokamaks

    Energy Technology Data Exchange (ETDEWEB)

    Dodel, G; Kunz, W [Stuttgart Univ. (TH) (Germany, F.R.). Inst. fuer Plasmaforschung

    1979-08-01

    Extension of FIR polarimetry to electron density measurements in Tokamaks is suggested as a possible alternative for devices in which FIR interferometry is not applicable or difficult to handle due to reduced accessibility or strong mechanical vibrations. The method is numerically simulated. The relative experimental simplicity compared with interferometry has to be paid for with symmetry assumptions which enter into the evaluation process.

  6. The density process of the minimal entropy Martingale measure in a ...

    African Journals Online (AJOL)

    In a stochastic volatility market the Radon-Nikodym density of the minimal entropy martingale measure can be expressed in terms of the solution of a semilinear partial differential equation (PDE). This fact has been explored and illustrated for the time-homogeneous case in a recent paper by Benth and Karlsen [3]. However ...

  7. STEREOCHEMICAL ASPECTS OF HYDRATION OF CARBOHYDRATES IN AQUEOUS-SOLUTIONS .3. DENSITY AND ULTRASOUND MEASUREMENTS

    NARCIS (Netherlands)

    GALEMA, SA; HOILAND, H

    1991-01-01

    Density and ultrasound measurements have been performed in aqueous solutions of pentoses, hexoses, methylpyranosides, and disaccharides as a function of molality of carbohydrate (0-0.3 mol kg-1). Partial molar volumes, partial molar isentropic compressibilities, and hydration numbers have been

  8. Microwave reflectrometry for electron density measurements in the TJ-1 tokamak plasma

    International Nuclear Information System (INIS)

    Anabitarte, E.; Bustamante, E.G.; Calderon, M.A.G.; Vegas, A.

    1986-01-01

    A study about microwave reflectometry to measure the outside profile of the electron plasma density on tokamak TJ-1 is presented. It is also presented the condition of applicability of this method after the characteristic parameters of the plasma and its resolution. The simulation of the plasma in laboratory by means of a metallic mirror causes the whole characterization of the reflectometer. (author)

  9. Measuring the Density of Different Materials by Using the Collimated Fast Neutron Beam

    Energy Technology Data Exchange (ETDEWEB)

    Sudac, D.; Nad, K.; Orlic, Z.; Obhodas, J. [Rudjer Boskovic Institute, Bijenicka c. 54, 10000 Zagreb (Croatia); Valkovic, V. [Rudjer Boskovic Institute, Zagreb (Croatia); Kvinticka 62, Zagreb (Croatia)

    2015-07-01

    It was demonstrated in the previous work that various threat materials could be detected inside the sea going cargo container by measuring the three variables, carbon and oxygen concentration and density of investigated material. Density was determined by measuring transmitted neutrons, which is not always practical in terms of setting up the instrument geometry. In order to enable more geometry flexibility, we have investigated the possibility of using the scattered neutrons in cargo material identification. For that purpose, the densities of different materials were measured depending on the position of neutron detectors and neutron generator with respect to the target position. One neutron detector was put above the target, one behind and one in front of the target, above the neutron generator. It was shown that all three positions of neutron detectors can be successfully used to measure the target density, but only if the detected neutrons are successfully discriminated from the gamma rays. Although the associated alpha particle technique/associate particle imaging (API) was used to discriminate the neutrons from the gamma rays, it is believed that the same results would be obtained by using the pulse shape discrimination method. In that way API technique can be avoided and the neutron generator which produces much higher beam intensity than 10{sup 8} n/s can be used. (authors)

  10. Sensor and method for measuring the areal density of magnetic nanoparticles on a micro-array

    NARCIS (Netherlands)

    2003-01-01

    The present invention relates to a method and a device for magnetic detection of binding of biological molecules on a biochip. A magnetoresistive sensor device for measuring an areal density of magnetic nanoparticles on a micro-array, the magnetic nanoparticles (15) being directly or indirectly

  11. Pinch density measurements in compact plasma foci of 400J and 50J

    International Nuclear Information System (INIS)

    Tarifeño-Saldivia, Ariel; Pavez, Cristian; Soto, Leopoldo

    2014-01-01

    A Mach-Zehnder interferometer using a pulsed Nd-YAG laser (600 mJ, 532 nm, 8 ns) was implemented to measure the electron density and the dimensions of the pinch column in two sub-kJ compact plasma focus devices operating at hundred joules (PF-400J) and tens of joules (PF-50J).

  12. Satellite accelerometer measurements of neutral density and winds during geomagnetic storms

    Science.gov (United States)

    Marcos, F. A.; Forbes, J. M.

    1986-01-01

    A new thermospheric wind measurement technique is reported which is based on a Satellite Electrostatic Triaxial Accelerometer (SETA) system capable of accurately measuring accelerations in the satellite's in-track, cross-track and radial directions. Data obtained during two time periods are presented. The first data set describes cross-track winds measured between 170 and 210 km during a 5-day period (25 to 29 March 1979) of mostly high geomagnetic activity. In the second data set, cross-track winds and neutral densities from SETA and exospheric temperatures from the Millstone Hill incoherent scatter radar are examined during an isolated magnetic substorm occurring on 21 March 1979. A polar thermospheric wind circulation consisting of a two cell horizontal convection pattern is reflected in both sets of cross-track acceleration measurements. The density response is highly asymmetric with respect to its day/night behavior. Latitude structures of the density response at successive times following the substorm peak suggest the equatorward propagation of a disturbance with a phase speed between 300 and 600 m/s. A deep depression in the density at high latitudes (less than 70 deg) is evident in conjunction with this phenomenon. The more efficient propagation of the disturbance to lower latitudes during the night is probably due to the midnight surge effect.

  13. High-resolution gamma ray attenuation density measurements on mining exploration drill cores, including cut cores

    Science.gov (United States)

    Ross, P.-S.; Bourke, A.

    2017-01-01

    Physical property measurements are increasingly important in mining exploration. For density determinations on rocks, one method applicable on exploration drill cores relies on gamma ray attenuation. This non-destructive method is ideal because each measurement takes only 10 s, making it suitable for high-resolution logging. However calibration has been problematic. In this paper we present new empirical, site-specific correction equations for whole NQ and BQ cores. The corrections force back the gamma densities to the "true" values established by the immersion method. For the NQ core caliber, the density range extends to high values (massive pyrite, 5 g/cm3) and the correction is thought to be very robust. We also present additional empirical correction factors for cut cores which take into account the missing material. These "cut core correction factors", which are not site-specific, were established by making gamma density measurements on truncated aluminum cylinders of various residual thicknesses. Finally we show two examples of application for the Abitibi Greenstone Belt in Canada. The gamma ray attenuation measurement system is part of a multi-sensor core logger which also determines magnetic susceptibility, geochemistry and mineralogy on rock cores, and performs line-scan imaging.

  14. Molecular Quantum Similarity Measures from Fermi hole Densities: Modeling Hammett Sigma Constants

    Czech Academy of Sciences Publication Activity Database

    Girónes, X.; Ponec, Robert

    2006-01-01

    Roč. 46, č. 3 (2006), s. 1388-1393 ISSN 1549-9596 Grant - others:SMCT(ES) SAF2000/0223/C03/01 Institutional research plan: CEZ:AV0Z40720504 Keywords : molecula quantum similarity measures * fermi hole densities * substituent effect Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.423, year: 2006

  15. Comparative measurement of the neutral density and particle confinement time in EBT

    International Nuclear Information System (INIS)

    Glowienka, J.C.; Richards, R.K.

    1985-11-01

    The neutral density and particle confinement time in the ELMO Bumpy Torus-Scale Experiment (EBT-S) have been determined by two different techniques. These involve a spectroscopic measurement of molecular and atomic hydrogen emissions and a time-decay measurement of a fast-ion population using a diagnostic neutral beam. The results from both diagnostics exhibit identical trends for either estimate, although the absolute values differ by a factor of 2 to 3. The observed variations with fill gas pressure and microwave power from either technique are consistent with measurements of electron density and temperature. In this paper, the measurement techniques are discussed, and the results are compared in the context of consistency with independently observed plasma behavior. 6 refs., 7 figs

  16. Measurement of average density and relative volumes in a dispersed two-phase fluid

    Science.gov (United States)

    Sreepada, Sastry R.; Rippel, Robert R.

    1992-01-01

    An apparatus and a method are disclosed for measuring the average density and relative volumes in an essentially transparent, dispersed two-phase fluid. A laser beam with a diameter no greater than 1% of the diameter of the bubbles, droplets, or particles of the dispersed phase is directed onto a diffraction grating. A single-order component of the diffracted beam is directed through the two-phase fluid and its refraction is measured. Preferably, the refracted beam exiting the fluid is incident upon a optical filter with linearly varing optical density and the intensity of the filtered beam is measured. The invention can be combined with other laser-based measurement systems, e.g., laser doppler anemometry.

  17. Do measures matter? Comparing surface-density-derived and census-tract-derived measures of racial residential segregation

    Directory of Open Access Journals (Sweden)

    Waller Lance A

    2010-06-01

    Full Text Available Abstract Background Racial residential segregation is hypothesized to affect population health by systematically patterning health-relevant exposures and opportunities according to individuals' race or income. Growing interest into the association between residential segregation and health disparities demands more rigorous appraisal of commonly used measures of segregation. Most current studies rely on census tracts as approximations of the local residential environment when calculating segregation indices of either neighborhoods or metropolitan areas. Because census tracts are arbitrary in size and shape, reliance on this geographic scale limits understanding of place-health associations. More flexible, explicitly spatial derivations of traditional segregation indices have been proposed but have not been compared with tract-derived measures in the context of health disparities studies common to social epidemiology, health demography, or medical geography. We compared segregation measured with tract-derived as well as GIS surface-density-derived indices. Measures were compared by region and population size, and segregation measures were linked to birth record to estimate the difference in association between segregation and very preterm birth. Separate analyses focus on metropolitan segregation and on neighborhood segregation. Results Across 231 metropolitan areas, tract-derived and surface-density-derived segregation measures are highly correlated. However overall correlation obscures important differences by region and metropolitan size. In general the discrepancy between measure types is greatest for small metropolitan areas, declining with increasing population size. Discrepancies in measures are greatest in the South, and smallest in Western metropolitan areas. Choice of segregation index changed the magnitude of the measured association between segregation and very preterm birth. For example among black women, the risk ratio for very

  18. Right ventricular systolic pressure measurements in combination with harvest of lung and immune tissue samples in mice.

    Science.gov (United States)

    Chen, Wen-Chi; Park, Sung-Hyun; Hoffman, Carol; Philip, Cecil; Robinson, Linda; West, James; Grunig, Gabriele

    2013-01-16

    The function of the right heart is to pump blood through the lungs, thus linking right heart physiology and pulmonary vascular physiology. Inflammation is a common modifier of heart and lung function, by elaborating cellular infiltration, production of cytokines and growth factors, and by initiating remodeling processes. Compared to the left ventricle, the right ventricle is a low-pressure pump that operates in a relatively narrow zone of pressure changes. Increased pulmonary artery pressures are associated with increased pressure in the lung vascular bed and pulmonary hypertension. Pulmonary hypertension is often associated with inflammatory lung diseases, for example chronic obstructive pulmonary disease, or autoimmune diseases. Because pulmonary hypertension confers a bad prognosis for quality of life and life expectancy, much research is directed towards understanding the mechanisms that might be targets for pharmaceutical intervention. The main challenge for the development of effective management tools for pulmonary hypertension remains the complexity of the simultaneous understanding of molecular and cellular changes in the right heart, the lungs and the immune system. Here, we present a procedural workflow for the rapid and precise measurement of pressure changes in the right heart of mice and the simultaneous harvest of samples from heart, lungs and immune tissues. The method is based on the direct catheterization of the right ventricle via the jugular vein in close-chested mice, first developed in the late 1990s as surrogate measure of pressures in the pulmonary artery. The organized team-approach facilitates a very rapid right heart catheterization technique. This makes it possible to perform the measurements in mice that spontaneously breathe room air. The organization of the work-flow in distinct work-areas reduces time delay and opens the possibility to simultaneously perform physiology experiments and harvest immune, heart and lung tissues. The

  19. A novel track density measurement method by thermal neutron activation of DYECETs

    International Nuclear Information System (INIS)

    Sohrabi, M.; Mahdi, Sh.

    1995-01-01

    A novel track density evaluation method based on thermal neutron activation of some elements of dyed electrochemically etched tracks (DYECETs) of charged particles in detectors like polycarbonate (PC) followed by measurements of gamma activity of the activated detectors is introduced. In this method, the tracks of charged particles like fast neutron-induced recoils in PC detectors were electrochemically etched, dyed by ''QuicDYECET'' methods as recently introduced by us, activated by thermal neutrons and counted for gamma activity determination to be correlated with track density. The activities of elements such as bromine-82 ( 82 Br) and sodium-24 ( 24 Na) on dyes such as Eosin Yellowish, Eosin Bluish, etc. determined by a hyper-pure germanium detector, were found to be in good correlation with DYECET density and thus particle fluence or dose. The effects of different types of dyes and their elements, dye concentration, neutron fluences and ECE durations on the DYECET density responses were studied. This new development is a method of scientific interest, potentially possessing some interesting features, as an alternative method for ECE track density determination using a gamma activity measuring system. It also has the drawback of being applicable only in centres having thermal neutron facilities. The results of the above studies are presented and discussed. (Author)

  20. Measured and predicted electron density at 600 km over Tucuman and Huancayo

    International Nuclear Information System (INIS)

    Ezquer, R.G.; Cabrera, M.A.; Araoz, L.; Mosert, M.; Radicella, S.M.

    2002-01-01

    The electron density at 600 Km of altitude (N 600 ) predicted by IRI are compared with the measurements for a given particular time and place (not average) obtained with the Japanese Hinotori satellite. The results showed that the best agreement among predictions and measurements were obtained near the magnetic equator. Disagreements about 50% were observed near the southern peak of the equatorial anomaly (EA), when the model uses the CCIR and URSI options to obtain the peak characteristics. (author)

  1. Measured density and calculated baricity of custom-compounded drugs for chronic intrathecal infusion.

    Science.gov (United States)

    Hejtmanek, Michael R; Harvey, Tracy D; Bernards, Christopher M

    2011-01-01

    To minimize the frequency that intrathecal pumps require refilling, drugs are custom compounded at very high concentrations. Unfortunately, the baricity of these custom solutions is unknown, which is problematic, given baricity's importance in determining the spread of intrathecally administered drugs. Consequently, we measured the density and calculated the baricity of clinically relevant concentrations of multiple drugs used for intrathecal infusion. Morphine, clonidine, bupivacaine, and baclofen were weighed to within 0.0001 g and diluted in volumetric flasks to produce solutions of known concentrations (morphine 1, 10, 25, and 50 mg/mL; clonidine 0.05, 0.5, 1, and 3 mg/mL; bupivacaine 2.5, 5, 10, and 20 mg/mL; baclofen 1, 1.5, 2, and 4 mg/mL). The densities of the solutions were measured at 37°C using the mechanical oscillation method. A "best-fit" curve was calculated for plots of concentration versus density for each drug. All prepared solutions of clonidine and baclofen were hypobaric. Higher concentrations of morphine and bupivacaine were hyperbaric, whereas lower concentrations were hypobaric. The relationship between concentration and density is linear for morphine (r > 0.99) and bupivacaine (r > 0.99) and logarithmic for baclofen (r = 0.96) and clonidine (r = 0.98). This is the first study to examine the relationship between concentration and density for custom drug concentrations commonly used in implanted intrathecal pumps. We calculated an equation that defines the relationship between concentration and density for each drug. Using these equations, clinicians can calculate the density of any solution made from the drugs studied here.

  2. Measurement of reactor parameters of the 'Nora' reactor by noise analysis method - power spectral density

    International Nuclear Information System (INIS)

    Jovanovic, S.; Stormark, E.

    1966-01-01

    Measurements of reactor parameters the Nora reactor by Power Spectral Density (PSD) method are described. In case of critical reactor this method was applied for direct measurement of β/l ratio, β is the effective yield of delayed neutrons and l is the neutron lifetime. In case of subcritical reactor values of α+β-ρ/l were measured, ρ is the negative reactivity. Out coming PSD was measured by a filter or by ISAC. PSD was registered by ISAC as well as the auto-correlation function [sr

  3. Temporal patterns of lung cancer risk from radon and smoking - consequences to remediation measures

    International Nuclear Information System (INIS)

    Tomasek, L.

    2004-01-01

    Studies of uranium miners conducted since the late 1960s demonstrated that the risk depends on cumulated exposure in terms of working level months (WLM) integrating both duration of exposure and concentration of radon. It has been also demonstrated that the risk from radon decreases with time since exposure. The present analysis of temporal changes of relative risk is based on a model where the total individual exposure is partitioned into components in dependence on time. Exposure to radon is studied in a cohort of 9411 Czech uranium miners with 766 cases of lung cancer and in a residential study of 11 803 inhabitants exposed to radon in houses with 218 cases. In addition, temporal patterns of the risk from smoking are analyzed in a case-control study of patients from a major Prague hospital including 566 cases. For both carcinogens, the relative risk decreases with time since exposure. The risk from exposures before 20-34 years is 36% and 34% in comparison to period 5-19 for smoking and radon, respectively. The effect of exposures from more distant periods 35-49 is only 5% for smoking and 14% for radon in comparison to 5-19 years. This substantial decrease of relative risk with time may contribute to a better evaluation of remediation measures taken in houses and in the cost effectiveness of remediation. Combined effect of smoking and radon is studied by a nested case-control approach including 434 cases and 962 controls. Analyses of the joint effects of smoking and radon, conducted in the occupational and the residential studies, suggest a sub-multiplicative interaction. The relative risk from radon among non-smokers is higher by a factor of 2-3 in comparison to smokers, suggesting different patterns of lung deposition and clearance among smokers and non-smokers. (author)

  4. Arterial Carboxyhemoglobin Measurement Is Useful for Evaluating Pulmonary Inflammation in Subjects with Interstitial Lung Disease.

    Science.gov (United States)

    Hara, Yu; Shinkai, Masaharu; Kanoh, Soichiro; Fujikura, Yuji; K Rubin, Bruce; Kawana, Akihiko; Kaneko, Takeshi

    2017-01-01

    Objective The arterial concentration of carboxyhemoglobin (CO-Hb) in subjects with inflammatory pulmonary disease is higher than that in healthy individuals. We retrospectively analyzed the relationship between the CO-Hb concentration and established markers of disease severity in subjects with interstitial lung disease (ILD). Methods The CO-Hb concentration was measured in subjects with newly diagnosed or untreated ILD and the relationships between the CO-Hb concentration and the serum biomarker levels, lung function, high-resolution CT (HRCT) findings, and the uptake in gallium-67 ( 67 Ga) scintigraphy were evaluated. Results Eighty-one non-smoking subjects were studied (mean age, 67 years). Among these subjects, (A) 17 had stable idiopathic pulmonary fibrosis (IPF), (B) 9 had an acute exacerbation of IPF, (C) 44 had stable non-IPF, and (D) 11 had an exacerbation of non-IPF. The CO-Hb concentrations of these subjects were (A) 1.5±0.5%, (B) 2.1±0.5%, (C) 1.2±0.4%, and (D) 1.7±0.5%. The CO-Hb concentration was positively correlated with the serum levels of surfactant protein (SP)-A (r=0.38), SP-D (r=0.39), and the inflammation index (calculated from HRCT; r=0.57) and was negatively correlated with the partial pressure of oxygen in the arterial blood (r=-0.56) and the predicted diffusion capacity of carbon monoxide (r=-0.61). The CO-Hb concentrations in subjects with a negative heart sign on 67 Ga scintigraphy were higher than those in subjects without a negative heart sign (1.4±0.5% vs. 1.1±0.3%, p=0.018). Conclusion The CO-Hb levels of subjects with ILD were increased, particularly during an exacerbation, and were correlated with the parameters that reflect pulmonary inflammation.

  5. Measurement of lung airways in three dimensions using hyperpolarized helium-3 MRI

    International Nuclear Information System (INIS)

    Peterson, Eric T; Fain, Sean B; Dai Jionghan; Holmes, James H

    2011-01-01

    Large airway measurement is clinically important in cases of airway disease and trauma. The gold standard is computed tomography (CT), which allows for airway measurement. However, the ionizing radiation dose associated with CT is a major limitation in longitudinal studies and trauma. To avoid ionizing radiation from CT, we present a method for measuring the large airway diameter in humans using hyperpolarized helium-3 (HPHe) MRI in conjunction with a dynamic 3D radial acquisition. An algorithm is introduced which utilizes the significant airway contrast for semi-automated segmentation and skeletonization which is used to derive the airway lumen diameter. The HPHe MRI method was validated with quantitative CT in an excised and desiccated porcine lung (linear regression R 2 = 0.974 and slope = 0.966 over 32 airway segments). The airway lumen diameters were then compared in 24 human subjects (22 asthmatics and 2 normals; linear regression R 2 value of 0.799 and slope = 0.768 over 309 airway segments). The feasibility for airway path analysis to areas of ventilation defect is also demonstrated.

  6. Lung nodule assessment in computed tomography. Precision of attenuation measurement based on computer-aided volumetry

    International Nuclear Information System (INIS)

    Knoess, Naomi; Hoffmann, B.; Fabel, M.; Wiese, C.; Bolte, H.; Heller, M.; Biederer, J.; Jochens, A.

    2009-01-01

    Purpose: to compare the reproducibility (r) of CT value measurement of pulmonary nodules using volumetry software (LungCare, LC) and manual ROIs (mROI). Materials and methods: 54 artificial nodules in a chest phantom were scanned three times with CT. CT values were measured with LC and mROI. The intrascan-r was assessed with three measurements in the first scan, and the interscan-r with measurements in three consecutive scans (one observer). Intrascan-r und interobserver-r (two obs.) were assessed in the first scan and in contrast-enhanced CT of 51 nodules from 15 patients (kernels b50f and b80f). Intrascan-r and interscan-r were described as the mean range and interobserver-r as the mean difference of CT values. The significance of differences was tested using t-test and sign test. Results: reproducibility was significantly higher for volumetry-based measurements in both artificial and patient nodules (range 0.11 vs. 6.16 HU for intrascan-r, 2.22 vs. 7.03 HU for interscan-r, difference 0.11 vs. 18.42 HU for interobserver-r; patients: 1.78 vs. 13.19 HU (b50f-Kernel) and 1.88 vs. 27.4 HU (b80f-Kernel) for intrascan-r, 3.71 vs. 22.43 HU for interobserver-r). Absolute CT values differed significantly between convolution kernels (pat./mROI: 29.3 [b50f] and 151.9 HU [b80f] pat./LC: 5 [b50f] and 147 HU [b80f]). Conclusion: the reproducibility of volumetry-based measurements of CT values in pulmonary nodules is significantly higher and should therefore be recommended, e.g. in dynamic chest CT protocols. Reproducibility does not depend on absolute CT values. (orig.)

  7. Rocket measurements of electric fields, electron density and temperature during the three phases of auroral substorms

    International Nuclear Information System (INIS)

    Marklund, G.; Block, L.; Lindqvist, P.-A.

    1979-12-01

    On Jan. 27, 1979, three rocket payloads were launched from Kiruna, Sweden, into different phases of two successive auroral substorms. Among other experiments, the payloads carried the RIT double probe electric field experiments, providing electric field, electron density and temperature data, which are presented here. These are discussed in association with observations of particles, ionospheric drifts (STARE) and electric fields in the equatorial plane (GEOS). The motions of the auroral forms, as obtained from auroral pictures are compared with the E x B/B 2 drifts and the currents calculated from the rocket electric field and density measurements with the equivalent current system deduced from ground based magnetometer data (SMA). (Auth.)

  8. Critical current density measurement of thin films by AC susceptibility based on the penetration parameter h

    DEFF Research Database (Denmark)

    Li, Xiao-Fen; Grivel, Jean-Claude; Abrahamsen, Asger B.

    2012-01-01

    We have numerically proved that the dependence of AC susceptibility χ of a E(J) power law superconducting thin disc on many parameters can be reduced to one penetration parameter h, with E the electric field and J the current density. Based on this result, we propose a way of measuring the critical...... current density Jc of superconducting thin films by AC susceptibility. Compared with the normally used method based on the peak of the imaginary part, our method uses a much larger range of the AC susceptibility curve, thus allowing determination of the temperature (T) dependence of Jc from a normally...

  9. Measurement and Analysis of Density of Molten Ni-W Alloys

    Institute of Scientific and Technical Information of China (English)

    FANG Liang; XIAO Feng; TAO Zainan; MuKai Kusuhiro

    2005-01-01

    The density of molten Ni-W alloys was measured with a modified pycnometric method. It is found that the density of the molten Ni- W alloys decreases with temperature rising, but increases with the increase of tungsten concentration in the alloys. The molar volume of molten Ni- W binary alloys increases with the increase of temperature and tungsten concentration. The partial molar volume of tungsten in liquid Ni- W binary alloy has been calculated approximately as ( - 1.59+ 5.64 × 10-3 T) × 10-6m3 ·mol-1.

  10. Molar Volume Analysis of Molten Ni-Al-Co Alloy by Measuring the Density

    Institute of Scientific and Technical Information of China (English)

    XIAO Feng; FANG Liang; FU Yuechao; YANG Lingchuan

    2004-01-01

    The density of molten Ni-Al-Co alloys was measured in the temperature range of 1714~1873K using a modified pycnometric method, and the molar volume of molten alloys was analyzed. The density of molten Ni-Al-Co alloys was found to decrease with increasing temperature and Co concentration in alloys. The molar volume of molten Ni-Al-Co alloys increases with increasing Co concentration in alloys. The molar volume of molten Ni-Al-Co alloys shows a negative deviation from the linear molar volume.

  11. Indirect Measurement of Energy Density of Soft PZT Ceramic Utilizing Mechanical Stress

    Science.gov (United States)

    Unruan, Muangjai; Unruan, Sujitra; Inkong, Yutthapong; Yimnirun, Rattikorn

    2017-11-01

    This paper reports on an indirect measurement of energy density of soft PZT ceramic utilizing mechanical stress. The method works analogous to the Olsen cycle and allows for a large amount of electro-mechanical energy conversion. A maximum energy density of 350 kJ/m3/cycle was found under 0-312 MPa and 1-20 kV/cm of applied mechanical stress and electric field, respectively. The obtained result is substantially higher than the results reported in previous studies of PZT materials utilizing a direct piezoelectric effect.

  12. The outcome of bone mineral density measurements on patients referred from general practice

    DEFF Research Database (Denmark)

    Iqbal, Sofia Inez; Mørch, Lina Steinrud; Rosenzweig, Mary

    2005-01-01

    The incidence of osteoporosis is increasing and the general practitioner is integral to identifying these patients. It is, therefore, of interest to characterize the referral pattern of patients scheduled for determination of bone density by means of dual-energy X-ray absorptiometry scanning. Alt......) increased the predictive value considerably. A low BMI is a good indicator for referral of women less than 60 yr for measurements of bone density. Forty-five percent of the referred women from general practitioners had a normal BMD....

  13. Measurement of current density fluctuations and ambipolar particle flux due to magnetic fluctuations in MST

    International Nuclear Information System (INIS)

    Shen, Weimin.

    1992-08-01

    Studies of magnetic fluctuation induced particle transport on Reversed Field Pinch plasmas were done on the Madison Symmetric Torus. Plasma current density and current density fluctuations were measured using a multi-coil magnetic probes. The low frequency (f parallel B r >. The result of zero net charged particle loss was obtained, meaning the flux is ambipolar. The ambipolarity of low frequency global tearing modes is satisfied through the phase relations determined by tearing instabilities. The ambipolarity of high frequency localized modes could be partially explained by the simple model of Waltz based on the radial average of small scale turbulence

  14. Measurement of Lung Cancer Tumor Markers in a Glass Wool Company Workers Exposed to Respirable Synthetic Vitreous Fiber and Dust

    Directory of Open Access Journals (Sweden)

    Shabnam Abtahi

    2018-01-01

    Full Text Available Background: Occupational exposures to respirable synthetic vitreous fiber (SVF and dust are associated with many lung diseases including lung cancer. Low-dose computed tomography is used for screening patients who are highly suspicious of having lung carcinoma. However, it seems not to be cost-effective. Serum biomarkers could be a useful tool for the surveillance of occupational exposure, by providing the possibility of diagnosing lung cancer in its early stages. Objective: To determine if serum carcinoembryonic antigen (CEA and cytokeratin fragment (CYFRA 21-1 levels in workers exposed more than normal population to respirable SVF and dust may be used as indicators of progression towards lung cancer. Methods: An analytic cross-sectional study, including 145 personnel of a glass wool company, along with 25 age-matched healthy individuals, was conducted to investigate the relationship between occupational exposure to respirable SVFs and dust and serum levels of two lung/pleura serum tumor markers, CEA and CYFRA 21-1, measured by ELISA. Results: Individuals exposed to higher than the recommended levels of respirable SVF had higher serum concentrations of CEA and CYFRA 21-1, compared to controls (p=0.008 and 0.040, respectively, as well as in comparison to those exposed to lower than recommended OSHA levels (p=0.046 and 0.033, respectively. Workers with >9 years work experience, had significantly (p=0.045 higher levels of serum CYFRA 21-1 than those with ≤9 years of experience. Conclusion: It seems that working for >9 years in sites with detectable levels of respirable SVF and dust would increase the levels of known lung cancer serum tumor markers. Transferring these workers to sites with respirable SVF concentrations lower than the limit of detection in the air is recommended.

  15. Measurement on the density resolution of industrial computerized tomography by using disc specimen with hol