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Sample records for suvmean short-axis diameter

  1. Short-axis epicardial volume change is a measure of cardiac left ventricular short-axis function, which is independent of myocardial wall thickness.

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    Ugander, Martin; Carlsson, Marcus; Arheden, Håkan

    2010-02-01

    Fractional shortening (FS) by echocardiography is considered to represent the short-axis contribution to the stroke volume (SV), also called short-axis function. However, FS is mathematically coupled to the amount of myocardium, since it rearranges during atrioventricular plane displacement (AVPD). The SV is the sum of the volumes generated by 1) reduction in outer volume of the heart, and 2) inner AVPD. The long-axis contribution to the SV is generated by AVPD, and thus the short-axis contribution is the remaining outer volume change of the heart, which should be unrelated to myocardial wall thickness. We hypothesized that both endocardial and midwall shortening indexed to SV are dependent on myocardial wall thickness, whereas epicardial volume change (EVC) indexed to SV is not. Twelve healthy volunteers (normals), 12 athletes, and 12 patients with dilated cardiomyopathy (ejection fraction EVC was defined as SV minus long-axis function. Endocardial and midwall shortening were measured in a midventricular short-axis slice. Endocardial shortening/SV and midwall shortening/SV both varied in relation to end-diastolic myocardial wall thickness (R(2) = 0.16, P = 0.008 and R(2) = 0.14, P = 0.012, respectively), whereas EVC/SV did not (R(2) = 0.00, P = 0.37). FS is dependent on myocardial wall thickness, whereas EVC is not and therefore represents true short-axis function. This is not surprising considering that FS is mainly caused by rearrangement of myocardium secondary to long-axis function. FS is therefore not synonymous with short-axis function.

  2. 3D segmentation of the left ventricle combining long- and short-axis MR images.

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    Säring, D; Relan, J; Groth, M; Müllerleile, K; Handels, H

    2009-01-01

    Segmentation of the left ventricle (LV) is required to quantify LV remodeling after myocardial infarction. Therefore spatiotemporal cine MR sequences including long-axis and short-axis images are acquired. In this paper a new segmentation method for fast and robust segmentation of the left ventricle is presented. The new approach considers the position of the mitral valve and the apex as well as the long-axis contours to generate a 3D LV surface model. The segmentation result can be checked and adjusted in the short-axis images. Finally quantitative parameters were extracted. For evaluation the LV was segmented in eight datasets of the same subject by two medical experts using a contour drawing tool and the new segmentation tool. The results of both methods were compared concerning interaction time and intra- and inter-observer variance. The presented segmentation method proved to be fast. The mean difference and standard deviation of all parameters are decreased. In case of intra-observer comparison e.g. the mean ESV difference is reduced from 8.8% to 0.5%. A semi-automatic LV segmentation method has been developed that combines long- and short-axis views. Using the presented approach the intra- and interobserver difference as well as the time for the segmentation process are decreased. So the semi-automatic segmentation using long- and short-axis information proved to be fast and robust for the quantification of LV mass and volume properties.

  3. Gaussian Element Formulation of Short-Axis Rotation of a Rigid Body

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    Fukushima, Toshio

    2008-08-01

    Equations of the short-axis-mode rotation of a rigid body under a general torque field are derived in terms of a new set of variables. The transformation between the new variables and the non-canonical Andoyer variables is explicitly given in closed form. The right-hand sides of the new equations are the sum of two main terms for two angle variables and six perturbative terms. All the perturbative terms are expressed as linear combinations of torque vector components. In the case of torque-free motions, the two angle variables become linear functions of time and the remaining four variables become constants of motion. As a result, the new variables consist of a set of rotational elements in a broad sense. This formulation is a counterpart, in rotational dynamics, of the Gaussian formulation of the Keplerian orbital elements for elliptic orbits.

  4. Non Invasive Estimation of Left VentrNon Invasive Estimation of Left Ventricular Normalized Torsion Angle in Healthy Persons by Echo Tracking Algorithm: Short Axis Viewicular Normalized Torsion Angle in Healthy Persons by Echo Tracking Algorithm: Short Axis View

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    Zahra Arab Baferani

    2011-12-01

    Full Text Available Background: Left ventricular (LV torsion angle is a key parameter of cardiac performance but is difficult to measure. The purpose of this study is to describe a noninvasive imaging method for the assessment of these complex cardiac motions. Objectives: In this study, left ventricular torsion angle and normalized torsion angle were estimated in the short axis view for healthy persons. Patients and Methods: We acquired basal and apical short axis left ventricular LV images in the short axis view for 14 healthy men to estimate LV torsion angle by echo tracking under a block-matching (BM algorithm. By extracting the instantaneous changes in total displacement vector in the short axis view throughout a cardiac cycle, we calculated the instantaneous rotation and torsion angles in the short axis view. To account for differences in heart size, normalized torsion was calculated based on the radius of both the apical and basal slices in the end diastolic frame. Results: Apical and basal rotation was measured from short axis images by automatic frame-to-frame tracking of grayscale echo patterns. The vertical and horizontal displacements of the apical level were more than those of the basal level. All data are expressed as mean ± standard deviation (SD. Data was tested for normal distribution and homogeneity of variance by the Kolmogorov-Smirnov test (K-S and Levene’s test respectively. The peak rotation angles of the basal and apical levels and LV torsion angle in the short axis view were 8.0 ± 1.6°, 9.5 ± 1.8°, and 17.3 ± 2.5°, respectively. The normalized torsion was calculated as 7.8 ± 1.3°, based on the basal maximum radius, the apical maximum radius, and the distance between the apical and basal levels. Conclusions: We conclude that the normalized torsion angle is an important biomechanical parameter, because it is independent of heart size and distorted geometries in pathological ventricles.

  5. Automatic short axis orientation of the left ventricle in 3D ultrasound recordings

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    Pedrosa, João.; Heyde, Brecht; Heeren, Laurens; Engvall, Jan; Zamorano, Jose; Papachristidis, Alexandros; Edvardsen, Thor; Claus, Piet; D'hooge, Jan

    2016-04-01

    The recent advent of three-dimensional echocardiography has led to an increased interest from the scientific community in left ventricle segmentation frameworks for cardiac volume and function assessment. An automatic orientation of the segmented left ventricular mesh is an important step to obtain a point-to-point correspondence between the mesh and the cardiac anatomy. Furthermore, this would allow for an automatic division of the left ventricle into the standard 17 segments and, thus, fully automatic per-segment analysis, e.g. regional strain assessment. In this work, a method for fully automatic short axis orientation of the segmented left ventricle is presented. The proposed framework aims at detecting the inferior right ventricular insertion point. 211 three-dimensional echocardiographic images were used to validate this framework by comparison to manual annotation of the inferior right ventricular insertion point. A mean unsigned error of 8, 05° +/- 18, 50° was found, whereas the mean signed error was 1, 09°. Large deviations between the manual and automatic annotations (> 30°) only occurred in 3, 79% of cases. The average computation time was 666ms in a non-optimized MATLAB environment, which potentiates real-time application. In conclusion, a successful automatic real-time method for orientation of the segmented left ventricle is proposed.

  6. Convolutional neural network regression for short-axis left ventricle segmentation in cardiac cine MR sequences.

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    Tan, Li Kuo; Liew, Yih Miin; Lim, Einly; McLaughlin, Robert A

    2017-07-01

    Automated left ventricular (LV) segmentation is crucial for efficient quantification of cardiac function and morphology to aid subsequent management of cardiac pathologies. In this paper, we parameterize the complete (all short axis slices and phases) LV segmentation task in terms of the radial distances between the LV centerpoint and the endo- and epicardial contours in polar space. We then utilize convolutional neural network regression to infer these parameters. Utilizing parameter regression, as opposed to conventional pixel classification, allows the network to inherently reflect domain-specific physical constraints. We have benchmarked our approach primarily against the publicly-available left ventricle segmentation challenge (LVSC) dataset, which consists of 100 training and 100 validation cardiac MRI cases representing a heterogeneous mix of cardiac pathologies and imaging parameters across multiple centers. Our approach attained a .77 Jaccard index, which is the highest published overall result in comparison to other automated algorithms. To test general applicability, we also evaluated against the Kaggle Second Annual Data Science Bowl, where the evaluation metric was the indirect clinical measures of LV volume rather than direct myocardial contours. Our approach attained a Continuous Ranked Probability Score (CRPS) of .0124, which would have ranked tenth in the original challenge. With this we demonstrate the effectiveness of convolutional neural network regression paired with domain-specific features in clinical segmentation. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Assessment of Left Ventricular Torsion in Short Axis View between Healthy Subjects and Significant Coronary Artery Disease Patients

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    Zahra Arab

    2013-09-01

    Full Text Available Background: Coronary artery disease causes changes in biomechanical parameters and function of myocardial. Recently, torsion angle is one of the most important mechanical parameters. Therefore in this study, torsion angle in healthy subjects and LAD significant coronary artery disease patients, using echo tracking method in short axis view, was evaluated.Materials and Methods: In cross sectional study, 14 healthy subjects and 10 patients with significant stenosis of LAD were evaluated. Two dimensional echocardiography images were scanned in apical and basal parasternal short axis view were recorded. Successive ultrasonic images were processed by echo tracking under block matching algorithm and peak torsion angle were estimated. Difference between healthy group and patient group were extracted by using peak torsion angle by the confidence level of 95%.Results: In this study, basal rotation angle, apical rotation angle and torsion angle in short axis view in significant coronary artery disease patients significantly decreased 33%, 44% and 38% relative to healthy subjects, respectively. Also time to reach peak torsion angle in LAD coronary artery stenosis patients increased 19% relative to healthy group.Conclusion: It seems, torsion angle in short axis view, can diagnose LAD coronary artery stenosis patients reative to healthy subject.

  8. Automatic segmentation of left ventricle cavity from short-axis cardiac magnetic resonance images.

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    Yang, Xulei; Song, Qing; Su, Yi

    2017-02-03

    In this paper, a computational framework is proposed to perform a fully automatic segmentation of the left ventricle (LV) cavity from short-axis cardiac magnetic resonance (CMR) images. In the initial phase, the region of interest (ROI) is automatically identified on the first image frame of the CMR slices. This is done by partitioning the image into different regions using a standard fuzzy c-means (FCM) clustering algorithm where the LV region is identified according to its intensity, size and circularity in the image. Next, LV segmentation is performed within the identified ROI by using a novel clustering method that utilizes an objective functional with a dissimilarity measure that incorporates a circular shape function. This circular shape-constrained FCM algorithm is able to differentiate pixels with similar intensity but are located in different regions (e.g. LV cavity and non-LV cavity), thus improving the accuracy of the segmentation even in the presence of papillary muscles. In the final step, the segmented LV cavity is propagated to the adjacent image frame to act as the ROI. The segmentation and ROI propagation are then iteratively executed until the segmentation has been performed for the whole cardiac sequence. Experiment results using the LV Segmentation Challenge validation datasets show that our proposed framework can achieve an average perpendicular distance (APD) shift of 2.23 ± 0.50 mm and the Dice metric (DM) index of 0.89 ± 0.03, which is comparable to the existing cutting edge methods. The added advantage over state of the art is that our approach is fully automatic, does not need manual initialization and does not require a prior trained model.

  9. Ultrasound-guided internal jugular vein access: Comparison between short axis and long axis techniques

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    Tarek F Tammam

    2013-01-01

    Full Text Available The use of real-time ultrasound (US is advantageous in the insertion of central venous catheters (CVCs in adults, especially in whom difficulties are anticipated for various reasons. The aim of the present study was to compare two different real-time 2-dimensional US-guided techniques [short axis view/out-of-plane approach (SAX OOP approach versus long axis view/in-plane approach (LAX IP approach] for internal jugular vein (IJV cannulation. In this prospective study, 90 critical care and hemodialysis patients were assigned for insertion of CVCs using either the real-time US-guided (SAX OOP approach or LAX IP approach or landmark technique (control group. Failed catheter placement, risk of complications from placement, failure on first attempt at placement, number of attempts until successful catheterization, time to successful catheterization, incidence of central line-associated blood stream infection (CLA-BSI and demographics of each patient were recorded. There were no significant differences in patient′s demographic characteristics, side of cannulation (right or left or presence of risk factors for difficult venous cannulation between the three groups of patients. Cannulation of the IJV was achieved in all patients by using US (SAX OOP and LAX IP approaches and in 27 of the patients (90% by using the landmark technique (P = 0.045. Average access time (skin to vein and number of attempts were comparable between the SAX OOP and the LAX IP approaches while significantly reduced in both US groups of patients compared with the landmark group (P <0.001. In the landmark group, puncture of the carotid artery occurred in 16.7% of the patients, hematoma in 23.3% of the patients, pneumothorax in 3.3% of the patients and CLA-BSI in 20% of the patients, which were all significantly increased compared with the US group (P <0.05. The findings of this study suggest that the SAX OOP and LAX IP approaches were comparable for cannulation of IJV in critical

  10. Goldstone radar evidence for short-axis mode non-principal-axis rotation of near-Earth asteroid (214869) 2007 PA8

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    Brozović, Marina; Benner, Lance A. M.; Magri, Christopher; Scheeres, Daniel J.; Busch, Michael W.; Giorgini, Jon D.; Nolan, Michael C.; Jao, Joseph S.; Lee, Clement G.; Snedeker, Lawrence G.; Silva, Marc A.; Lawrence, Kenneth J.; Slade, Martin A.; Hicks, Michael D.; Howell, Ellen S.; Taylor, Patrick A.; Sanchez, Juan A.; Reddy, Vishnu; Dykhuis, Melissa; Le Corre, Lucille

    2017-04-01

    We report radar and optical photometric observations of near-Earth asteroid (214869) 2007 PA8 obtained during October 2-November 13, 2012. We observed 2007 PA8 on sixteen days with Goldstone (8560 MHz, 3.5 cm) and on five days with the 0.6 m telescope at Table Mountain Observatory. Closest approach was on November 5 at a distance of 0.043 au. Images obtained with Goldstone's new chirp system achieved range resolutions as fine as 3.75 m, placing thousands of pixels on the asteroid's surface, and revealing that 2007 PA8 is an elongated, asymmetric object. Surface features include angularities, facets, and a concavity approximately 400 m in diameter. We used the Shape software to estimate the asteroid's 3D shape and spin state. 2007 PA8 has a broad, rounded end and a tapered, angular end with sharp-crested ridges. The asteroid's effective diameter is 1.35 ± 0.07 km, which in combination with the absolute magnitude of 16.30 ± 0.52 gives an optical albedo of pV = 0.29 ± 0.14. The shape modeling of the radar data revealed that 2007 PA8 is a non-principal axis (NPA) rotator in the short-axis mode with an average period of precession by the long axis around the angular momentum vector of 4.26 ± 0.02 days and an oscillatory period around the long axis of 20.55 ± 3.75 days. The amplitude of rolling around the long axis is 42 ± 7° . The angular momentum vector points toward ecliptic longitude and latitude of 273.6 ± 10°, +16.9 ± 5°. 2007 PA8 is only the second confirmed short-axis mode NPA rotator known in the near-Earth asteroid population after (99942) Apophis (Pravec et al., 2014). 2007 PA8 has a geopotential high at the equator, where the equator is defined as the plane that contains the long and intermediate axis. This geopotential extreme could be interpreted as a large, hidden surface depression, or as evidence that 2007 PA8 is a multi-component body.

  11. Ventricular short-axis measurements in patients with pulmonary embolism: Effect of ECG-gating on variability, accuracy, and risk prediction

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    Scheffel, Hans, E-mail: hscheffel@partners.org [Institute of Diagnostic Radiology, University Hospital Zurich (Switzerland); Cardiac MR PET CT Program, Massachusetts General Hospital and Harvard Medical School, Boston (United States); Stolzmann, Paul [Institute of Diagnostic Radiology, University Hospital Zurich (Switzerland); Cardiac MR PET CT Program, Massachusetts General Hospital and Harvard Medical School, Boston (United States); Leschka, Sebastian; Desbiolles, Lotus [Institute of Diagnostic Radiology, University Hospital Zurich (Switzerland); Seifert, Burkhardt [Biostatistics Unit, Institute of Social and Preventive Medicine, University of Zurich (Switzerland); Marincek, Borut [Institute of Diagnostic Radiology, University Hospital Zurich (Switzerland); Alkadhi, Hatem [Institute of Diagnostic Radiology, University Hospital Zurich (Switzerland); Cardiac MR PET CT Program, Massachusetts General Hospital and Harvard Medical School, Boston (United States)

    2012-09-15

    Objective: To assess prospectively the intra- and interobserver variability, accuracy, and prognostic value of right and left ventricular short-axis diameter (RVd and LVd) measurements for risk stratification in patients with pulmonary embolism (PE) using ECG-gated compared to non-gated CT. Materials and methods: Sixty consecutive patients (33 women; mean age 58.7 ± 10.3 years) with suspicion of PE underwent both non-gated and ECG-gated chest CT. RVd and LVd on four-chamber views and intra- and interobserver agreements were calculated for both protocols. RVd/LVd ratios were calculated and were related to 30-days adverse clinical events using receiver operating characteristics with area-under-the-curve (AUC) analyses. Results: Both inter- and intraobserver variability showed narrower limits of agreement for all measurements with ECG-gated as compared to non-gated CT. Diameter measurements were significantly lower using non-ECG-gated CT as compared to ECG-gated CT for RVd and LVd (both p < .05). The AUC for the RVd/LVd ratio from ECG-gated CT was significantly larger than that from non-gated CT (0.956, 95% CI: 0.768–0.999 versus 0.675, 95% CI: 0.439–0.860; p = .048). Conclusion: RVd and LVd measurements from ECG-gated chest CT show less intra- and interobserver variability and more accurately reflect ventricular function. In our patient cohort ECG-gated chest CT allows better prediction of short-term outcome of patients with acute PE that needs to be validated in a larger outcome study.

  12. Comparison of US-Guided Catheterization of the Right Internal Jugular Vein Using Medial-Oblique and Short Axis Techniques

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    Hamid Kamalipour

    2014-09-01

    Full Text Available Background: Although some investigations have shown higher rates of successful first attempt and fewer attempts by using ultrasound-guided Internal Jugular Vein (IJV catheterization, arterial puncture is still common.. Objectives: The present study aimed to investigate US-guided catheterization of the right IJV via medial-oblique technique and also compare this technique to short-axis technique in open-heart surgery patients.. Patients and Methods: In this randomized clinical trial, 80 patients referred to cardiac operating room of Namazi hospital, Shiraz, Iran from March to July 2014 were selected using census method. Block randomization with website was also done. Then, the patients were divided into two groups of 40, Short Axis Group (SAG and Medial-Oblique Group (M-OG. For short-axis technique, patient’s head was positioned at zero degree angulation with his trunk. For medial-oblique technique, on the other hand, patient’s head was tilted to left to 45 degrees between the head and trunk. Sex, age, Body Mass Index (BMI, access time, guidewire time, cannulation time, total attempts for catheterization, first, second, and third attempt success, arterial puncture, hematoma, bleeding, and catheter malposition were recorded. The overlap between the carotid artery and IJV in zero- and 45-degree angulation was estimated through ultrasound print. After all, Kolmogorov-Smirnov test was used to assess normal distribution of the data. Then, the data were analyzed through Student’s t-test, Mann-Whitney U test, and chi-square test. P < 0.05 was considered as statistically significant.. Results: The results showed no significant differences between the two groups regarding the duration of different catheterization steps (P = 0.376. In all the cases in both groups, accessing the vein was successful with three attempts or less. There were no clinical complications of catheterization in the two groups. The mean of overlap was 23.60 ± 33.47 in zero

  13. Subendocardial motion in hypertrophic cardiomyopathy: assessment from long- and short-axis views by pulsed tissue Doppler imaging

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    Tabata, T.; Oki, T.; Yamada, H.; Abe, M.; Onose, Y.; Thomas, J. D.

    2000-01-01

    BACKGROUND: Tissue Doppler imaging (TDI) is a recently developed technique that allows the instantaneous measurement of intrinsic regional myocardial motion velocity. Pulsed TDI is capable of separately assessing left ventricular (LV) regional motion velocity caused by circumferential and longitudinal fiber contraction. This particular feature of function is still controversial in patients with hypertrophic cardiomyopathy (HC). METHODS: To better characterize intrinsic circumferential and longitudinal LV systolic myocardial function in HC, we used pulsed TDI to measure short- and long-axis LV motion velocities, respectively. The subendocardial motion velocity patterns at the middle of the LV posterior wall (PW) and ventricular septum (IVS) in LV parasternal and apical long-axis views were recorded by pulsed TDI in 19 patients with nonobstructive HC and in 21 normal controls (NC). RESULTS: Peak short- and long-axis systolic subendocardial velocities in both the LV PW and IVS were significantly smaller in the HC group than in the NC group, and the time to peak velocity was significantly delayed. Furthermore, peak PW systolic velocity was significantly greater along the long axis than along the short axis in the NC group (8.8 +/- 1.5 cm/s vs 8.2 +/- 1.4 cm/s, P <.05), whereas the opposite was observed in the HC group (6.1 +/- 1.2 cm/s vs 7.5 +/- 1.0 cm/s, P <.0001). No significant differences were found in either group between the long- and short-axis IVS velocities (HC: 5.9 +/- 1.4 cm/s vs 5.5 +/- 1.3 cm/s; NC: 7.8 +/- 1.3 cm/s vs 7.9 +/- 1.6 cm/s). CONCLUSIONS: By using the capability of pulsed TDI for the evaluation of intrinsic myocardial velocity instantaneously in a specific region and direction, we found impairment of LV myocardial systolic function in patients with HC not only in the hypertrophied IVS but also in the nonhypertrophied LV PW. We also found a greater decrease in LV PW velocities along the long axis than the short axis, suggesting greater

  14. Automated short-axis cardiac magnetic resonance image acquisitions: accuracy of left ventricular dimension measurements in normal subjects and patients.

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    Danilouchkine, Mikhail G; Westenberg, Jos J M; Reiber, Johan H C; Lelieveldt, Boudewijn P F

    2004-12-01

    This study investigates the use of an automated observer-independent planning system for short-axis cardiovascular magnetic resonance (MR) acquisitions in the clinical environment. The capacity of the automated method to produce accurate measurements of left ventricular dimensions and function was quantitatively assessed in normal subjects and patients. Fourteen healthy volunteers and 8 patients underwent cardiovascular MR (CMR) acquisitions for ventricular function assessment. Short-axis datasets of the left ventricle (LV) were acquired in 2 ways: manually planned and generated in an automatic fashion. End-diastolic volume (EDV), end-systolic volume (ESV), ejection fraction (EF), and left ventricular mass (LVM) were derived from the 2 datasets. The agreement between the manual and automatic planning methods was assessed. The mean differences between the manual and automated CMR planning methods for the normal subjects and patients were 5.89 mL and 1.93 mL (EDV), 1.14 mL and -0.41 mL (ESV), 0.81% and 0.89% (EF), and 4.35 g and 3.88 g (LVM), respectively. There was no significant difference in ESV and EF. LVM significantly differed in both groups, whereas EDV was significantly different in the normal subjects and insignificantly different in the patients. The variability coefficients were 2.8 and 3.59 (EDV), 3.3 and 5.03 (ESV), 1.79 and 2.65 (EF), and 4.36 and 2.27 (LVM) for the normal subjects and patients, respectively. The mean angular deviation of the LV axes turned out to be 8.58 +/- 5.76 degrees for the normal subjects and 8.35 +/- 5.15 degrees for the patients. Automated CMR planning method can provide accurate measurements of LV dimensions in normal subjects and patients, and therefore, can be used in the clinical environment for functional assessment of the human cardiovascular system.

  15. Nodal parameters of FDG PET/CT performed during radiotherapy for locally advanced mucosal primary head and neck squamous cell carcinoma can predict treatment outcomes: SUVmean and response rate are useful imaging biomarkers

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    Lin, Peter [Liverpool Hospital, Department of Nuclear Medicine and PET, Liverpool BC, NSW (Australia); University of New South Wales, South Western Sydney Clinical School, Sydney, NSW (Australia); Western Sydney University, Sydney, NSW (Australia); Min, Myo; Forstner, Dion [University of New South Wales, South Western Sydney Clinical School, Sydney, NSW (Australia); Liverpool Hospital, Cancer Therapy Centre, Liverpool, NSW (Australia); Ingham Institute of Applied Medical Research, Liverpool, NSW (Australia); Lee, Mark [University of New South Wales, South Western Sydney Clinical School, Sydney, NSW (Australia); Liverpool Hospital, Cancer Therapy Centre, Liverpool, NSW (Australia); Holloway, Lois [University of New South Wales, South Western Sydney Clinical School, Sydney, NSW (Australia); Western Sydney University, Sydney, NSW (Australia); Liverpool Hospital, Cancer Therapy Centre, Liverpool, NSW (Australia); Ingham Institute of Applied Medical Research, Liverpool, NSW (Australia); Bray, Victoria; Fowler, Allan [Liverpool Hospital, Cancer Therapy Centre, Liverpool, NSW (Australia)

    2017-05-15

    To evaluate the prognostic utility of nodal metabolic parameters derived from FDG PET/CT performed before radiotherapy (prePET) and during the third week of radiotherapy (iPET) in patients with mucosal primary head and neck squamous cell carcinoma (MPHNSCC). This analysis included 75 patients with newly diagnosed locally advanced node-positive MPHNSCC treated with radical radiotherapy and concurrent systemic therapy who underwent prePET and iPET: N1 11 patients, N2a 38, N2b 12, N2c 9, N3 5. The median follow-up was 28 months (9 - 70 months). The maximum and mean standardized uptake values (SUVmax and SUVmean), metabolic tumour volume (MTV) and total lesional glycolysis (TLG) of the index lymph node (node with the highest TLG) and the combined total lymph nodes, and their percentage reductions on iPET were determined, and the results were correlated with 3-year Kaplan-Meier locoregional, regional and distant metastatic failure-free survival (FFS), disease-free survival (DFS) and overall survival (OS). Optimal cut-off values were derived from receiver operating characteristic curves. Cox regression univariate and multivariate analyses with clinical covariates were performed. Based on assessment of residual nodal metabolic burden during treatment, the iPET index node SUVmean (optimal cut-off value 2.95 g/ml) and the total node SUVmean (optimal cut-off value 3.25) were the best independent predictors of outcome in the multivariate analysis: index node SUVmean for DFS and OS p = 0.033 and 0.003, respectively, and the total node SUVmean for locoregional FFS, DFS and OS p = 0.028, 0.025 and 0.014, respectively. Based on the assessment of response rates during treatment, a reduction of more than 50 % in the total node TLG was the best biomarker for locoregional and regional FFS, DFS and OS in the multivariate analysis (p = 0.001, 0.016, 0.001 and 0.004, respectively), and reduction in the total node MTV for locoregional FFS, DFS and OS (p = 0.026, 0.003 and 0

  16. Dynamic ultrasound-guided short-axis needle tip navigation technique vs. landmark technique for difficult saphenous vein access in children: a randomised study.

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    Hanada, S; Van Winkle, M T; Subramani, S; Ueda, K

    2017-12-01

    Dynamic ultrasound-guided short-axis needle tip navigation is a novel technique for vascular access. After venipuncture, the needle and catheter are further advanced within the vessel lumen under real-time ultrasound guidance with constant visualisation of the needle tip in the short-axis view. This can minimise the risk of transfixing the cannulated vessel. We compared two techniques for non-visible saphenous vein cannulation under general anaesthesia in children weighing ≥ 3 kg and less than four years of age: dynamic ultrasound-guided short-axis needle tip navigation technique (ultrasound group) vs. landmark technique. Venous cannulation was performed by three experienced anaesthetists. The primary outcome measure was first-attempt success rate. Success rate within 10 min was a secondary outcome. A total of 102 patients were randomly allocated to either the ultrasound group or the landmark group. First-attempt success rate was 90% in the ultrasound group compared with 51% in the landmark group, pdynamic ultrasound-guided short-axis needle tip navigation technique improved non-visible saphenous vein cannulation in children compared with the landmark technique. © 2017 The Association of Anaesthetists of Great Britain and Ireland.

  17. Fast susceptibility-weighted imaging with three-dimensional short-axis propeller (SAP)-echo-planar imaging.

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    Holdsworth, Samantha J; Yeom, Kristen W; Moseley, Michael E; Skare, S

    2015-05-01

    Susceptibility-weighted imaging (SWI) in neuroimaging can be challenging due to long scan times of three-dimensional (3D) gradient recalled echo (GRE), while faster techniques such as 3D interleaved echo-planar imaging (iEPI) are prone to motion artifacts. Here we outline and implement a 3D short-axis propeller echo-planar imaging (SAP-EPI) trajectory as a faster, motion-correctable approach for SWI. Experiments were conducted on a 3T MRI system. The 3D SAP-EPI, 3D iEPI, and 3D GRE SWI scans were acquired on two volunteers. Controlled motion experiments were conducted to test the motion-correction capability of 3D SAP-EPI. The 3D SAP-EPI SWI data were acquired on two pediatric patients as a potential alternative to 2D GRE used clinically. The 3D GRE images had a better target resolution (0.47 × 0.94 × 2 mm, scan time = 5 min), iEPI and SAP-EPI images (resolution = 0.94 × 0.94 × 2 mm) were acquired in a faster scan time (1:52 min) with twice the brain coverage. SAP-EPI showed motion-correction capability and some immunity to undersampling from rejected data. While 3D SAP-EPI suffers from some geometric distortion, its short scan time and motion-correction capability suggest that SAP-EPI may be a useful alternative to GRE and iEPI for use in SWI, particularly in uncooperative patients. © 2014 Wiley Periodicals, Inc.

  18. Performance comparison of ultrasound-based methods to assess aortic diameter and stiffness in normal and aneurysmal mice.

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    Bram Trachet

    Full Text Available Several ultrasound-based methods are currently used to assess aortic diameter, circumferential strain and stiffness in mice, but none of them is flawless and a gold standard is lacking. We aimed to assess the validity and sensitivity of these methods in control animals and animals developing dissecting abdominal aortic aneurysm.We first compared systolic and diastolic diameters as well as local circumferential strains obtained in 47 Angiotensin II-infused ApoE(-/- mice with three different techniques (BMode, short axis MMode, long axis MMode, at two different abdominal aortic locations (supraceliac and paravisceral, and at three different time points of abdominal aneurysm formation (baseline, 14 days and 28 days. We found that short axis BMode was preferred to assess diameters, but should be avoided for strains. Short axis MMode gave good results for diameters but high standard deviations for strains. Long axis MMode should be avoided for diameters, and was comparable to short axis MMode for strains. We then compared pulse wave velocity measurements using global, ultrasound-based transit time or regional, pressure-based transit time in 10 control and 20 angiotensin II-infused, anti-TGF-Beta injected C57BL/6 mice. Both transit-time methods poorly correlated and were not able to detect a significant difference in PWV between controls and aneurysms. However, a combination of invasive pressure and MMode diameter, based on radio-frequency data, detected a highly significant difference in local aortic stiffness between controls and aneurysms, with low standard deviation.In small animal ultrasound the short axis view is preferred over the long axis view to measure aortic diameters, local methods are preferred over transit-time methods to measure aortic stiffness, invasive pressure-diameter data are preferred over non-invasive strains to measure local aortic stiffness, and the use of radiofrequency data improves the accuracy of diameter, strain as well

  19. Differentiation of subendocardial and transmural infarction using two-dimensional strain rate imaging to assess short-axis and long-axis myocardial function.

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    Chan, Jonathan; Hanekom, Lizelle; Wong, Chiew; Leano, Rodel; Cho, Goo-Yeong; Marwick, Thomas H

    2006-11-21

    This study sought to differentiate the transmural extent of infarction (TME) by assessment of the short-axis and long-axis function of the left ventricle (LV) using 2-dimensional (2D) strain. The differentiation of subendocardial infarction from transmural infarction has significant prognostic and clinical implications. Contrast-enhanced magnetic resonance imaging (CE-MRI) and dobutamine stress echocardiography (DBE) were performed in 80 patients (age 63 +/- 10 years) with chronic ischemic LV dysfunction. Myocardial function was assessed in the short axis at the midventricular level using peak strain rate (SR) and strain (S) in circumferential and radial dimensions, and was assessed in the long axis using longitudinal SR and S. Wall motion analysis was performed during DBE to assess for contractile reserve. Transmural infarct segments had lower circumferential S (-10.7 +/- 6.3) and SR (-1.0 +/- 0.4) than subendocardial infarcts (S: -15.4 +/- 7.0, p subendocardial infarct segments had similar radial S and SR. Subendocardial infarct segments showed significant reduction of longitudinal S (-13.2 +/- 5.6) and SR (-0.91 +/- 0.45) compared with normal myocardium (S: -17.8 +/- 5.4, p subendocardial and transmural infarct segments (p = 0.09). Wall motion analysis by DBE could not identify subendocardial infarction on CE-MRI (TME 1% to 50%: DBE scar 38%, DBE viable 38%, DBE ischemic 24%, p = NS). The combined assessment of long-axis and short-axis function using 2D strain may be used to identify TME.

  20. A novel technique for ultrasound-guided central venous catheterization under short-axis out-of-plane approach: "stepwise flashing with triangulation".

    Science.gov (United States)

    Horiuchi, Toshinori; Okuda, Chie; Kurita, Naoko; Yamaguchi, Ayako; Kitagawa, Kazuhiko; Takeda, Masafumi; Sha, Keiichi; Nagahata, Toshihiro

    2017-10-01

    In ultrasound-guided central venous catheterization, there is no standard technique either for the needle tip visualization or for the adequate needle angle and entry to the skin with short-axis view under out-of-plane technique. In the present study, we propose a novel technique named "stepwise flashing with triangulation", and the efficacy of this technique is assessed. Before and after a didactic session in which the technique was explained, 12 novice residents were asked to position the needle tip on or into the imitation vessels and to avoid deeper penetration by using an agar tissue phantom with ultrasound guidance. "Stepwise flashing" technique was for stepwise visualization of the needle tip, and "triangulation" technique was for adequate needle angle and entry to the skin. After the session, the success rate was increased and a deeper penetration rate was decreased. This technique will help us to facilitate vascular access and to avoid complications in clinical settings.

  1. Influence of positional and angular variation of automatically planned short-axis stacks on quantification of left ventricular dimensions and function with cardiovascular magnetic resonance.

    Science.gov (United States)

    Danilouchkine, Mikhail G; van der Geest, Rob J; Westenberg, Jos J M; Lelieveldt, Boudewijn P F; Reiber, Johan H C

    2005-12-01

    To theoretically and experimentally investigate the influence of the automated cardiovascular magnetic resonance (CMR) scan planning pitfalls, namely inaccurate positioning and tilting of short-axis (SA) imaging planes, on quantification of the left ventricular (LV) dimensions and function. Eleven healthy subjects and eight patients underwent CMR. Manually and automatically planned SA sets were acquired. To obtain the quantitative measurements of LV function, one observer performed image analysis twice. The agreement between planning methods, as well as the decomposition of the total variation into interstudy and intraobserver components was measured. The decomposition of the total variation showed that the interstudy factor accounts for 70-85% of the total variation, while the rest is due to the intraobserver factor. Moreover, the relative contribution of the interstudy factor remains independent from errors in slice positioning and small angular deviation of SA stacks from the optimal orientation. Good agreement between the theoretical and measured variability factors was observed. Global LV function derived from the automatically planned CMR acquisitions yield accurate quantification of the human cardiovascular system. Inaccurate positioning and tilting of SA images does not affect the quantitative measurements of LV function. The computer-aided system for automated CMR has proven clinical applicability.

  2. Repeatability of quantitative FDG-PET/CT and contrast-enhanced CT in recurrent ovarian carcinoma: test-retest measurements for tumor FDG uptake, diameter, and volume.

    Science.gov (United States)

    Rockall, Andrea G; Avril, Norbert; Lam, Raymond; Iannone, Robert; Mozley, P David; Parkinson, Christine; Bergstrom, Donald; Sala, Evis; Sarker, Shah-Jalal; McNeish, Iain A; Brenton, James D

    2014-05-15

    Repeatability of baseline FDG-PET/CT measurements has not been tested in ovarian cancer. This dual-center, prospective study assessed variation in tumor 2[18F]fluoro-2-deoxy-D-glucose (FDG) uptake, tumor diameter, and tumor volume from sequential FDG-PET/CT and contrast-enhanced computed tomography (CECT) in patients with recurrent platinum-sensitive ovarian cancer. Patients underwent two pretreatment baseline FDG-PET/CT (n = 21) and CECT (n = 20) at two clinical sites with different PET/CT instruments. Patients were included if they had at least one target lesion in the abdomen with a standardized uptake value (SUV) maximum (SUVmax) of ≥ 2.5 and a long axis diameter of ≥ 15 mm. Two independent reading methods were used to evaluate repeatability of tumor diameter and SUV uptake: on site and at an imaging clinical research organization (CRO). Tumor volume reads were only performed by CRO. In each reading set, target lesions were independently measured on sequential imaging. Median time between FDG-PET/CT was two days (range 1-7). For site reads, concordance correlation coefficients (CCC) for SUVmean, SUVmax, and tumor diameter were 0.95, 0.94, and 0.99, respectively. Repeatability coefficients were 16.3%, 17.3%, and 8.8% for SUVmean, SUVmax, and tumor diameter, respectively. Similar results were observed for CRO reads. Tumor volume CCC was 0.99 with a repeatability coefficient of 28.1%. There was excellent test-retest repeatability for FDG-PET/CT quantitative measurements across two sites and two independent reading methods. Cutoff values for determining change in SUVmean, SUVmax, and tumor volume establish limits to determine metabolic and/or volumetric response to treatment in platinum-sensitive relapsed ovarian cancer. ©2014 American Association for Cancer Research.

  3. Failure Diameter Resolution Study

    Energy Technology Data Exchange (ETDEWEB)

    Menikoff, Ralph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-12-19

    Previously the SURFplus reactive burn model was calibrated for the TATB based explosive PBX 9502. The calibration was based on fitting Pop plot data, the failure diameter and the limiting detonation speed, and curvature effect data for small curvature. The model failure diameter is determined utilizing 2-D simulations of an unconfined rate stick to find the minimum diameter for which a detonation wave propagates. Here we examine the effect of mesh resolution on an unconfined rate stick with a diameter (10mm) slightly greater than the measured failure diameter (8 to 9 mm).

  4. Diameter Perfect Lee Codes

    CERN Document Server

    Horak, Peter

    2011-01-01

    Lee codes have been intensively studied for more than 40 years. Interest in these codes has been triggered by the Golomb-Welch conjecture on the existence of perfect error-correcting Lee codes. In this paper we deal with the existence and enumeration of diameter perfect Lee codes. As main results we determine all q for which there exists a linear diameter-4 perfect Lee code of word length n over Z_{q}, and prove that for each n\\geq3 there are unaccountably many diameter-4 perfect Lee codes of word length n over Z. This is in a strict contrast with perfect error-correcting Lee codes of word length n over Z as there is a unique such code for n=3, and its is conjectured that this is always the case when 2n+1 is a prime. Diameter perfect Lee codes will be constructed by an algebraic construction that is based on a group homomorphism. This will allow us to design an efficient algorithm for their decoding.

  5. Normal cardiac diameters in cine-MRI of the heart; Normalwerte der Herzdurchmesser in der Cine-MRT

    Energy Technology Data Exchange (ETDEWEB)

    Hergan, K.; Schuster, A.; Mair, M.; Burger, R.; Toepker, M. [Zentrales Inst. fuer Radiologie, Landeskrankenhaus Feldkirch (Austria)

    2004-11-01

    Purpose: To measure the normal diameters of cardiac cavities in standard cardiac views using cine MRI. Materials and Methods: Fifty-six volunteers were examined (27 male, 29 female) on a 1.5 T MR unit with ECG-triggered single shot free precision (SSFP) cine MR sequences and parallel image acquisition. Standardized echocardiographic planes were used to depict the heart of all volunteers (short axis, 4-chamber view, left and right 2-chamber views). The different diameters of the cardiac cavities were measured using a fixed protocol. Results: For the estimation of ventricular dilatation, the important female/male cross diameters of the left ventricle are 45.2{+-}3.4/51.6{+-}4.6 mm diastolic and 30.5{+-}3.5/33.8{+-}3.6 mm systolic, and of the right ventricle 30.7{+-}3.8/37.1{+-}5.9 mm diastolic and 22.3{+-}3.8/28.1{+-}4.4 mm systolic. For the determination of a left ventricular hypertrophy, relevant septal wall thickness measured in the short axis of the left ventricle of female/male volunteers are 8.0{+-}1.0/9.9{+-}1.2 mm diastolic and 10.9{+-}1.4/13.6{+-}1.9 mm systolic. The measured normal values of male volunteers were generally higher than those of female volunteers. The thickness of the ventricular septum correlated well when measured in the short axis and 4-chamber view. When measured in the 4-chamber view, the longitudinal diameter of the ventricles had a higher value in diastole and a lower value in systole, compared to the 2-chamber views of the right and left cardiac cavities. The atrial longitudinal diameters were higher in the 4-chamber view compared to the 2-chamber views, without any difference in systole or diastole. Conclusion: Diameters of cardiac cavities are easily and quickly measured. Using the tables with the normal values published here, it is simple to estimate an abnormal size of the heart. (orig.)

  6. The DIAMET campaign

    Science.gov (United States)

    Vaughan, G.

    2012-04-01

    DIAMET (DIAbatic influences on Mesoscale structures in ExTratropical storms) is a joint project between the UK academic community and the Met Office. Its focus is on understanding and predicting mesoscale structures in synoptic-scale storms, and in particular on the role of diabatic processes in generating and maintaining them. Such structures include fronts, rain bands, secondary cyclones, sting jets etc, and are important because much of the extreme weather we experience (e.g. strong winds, heavy rain) comes from such regions. The project conducted two field campaigns in the autumn of 2011, from September 14 - 30 and November 24 - December 14, based around the FAAM BAe146 aircraft with support from ground-based radar and radiosonde measurements. Detailed modelling, mainly using the Met Office Unified model, supported the planning and interpretation of these campaigns. This presentation will give a brief overview of the campaigns. Both in September and November-December the weather regime was westerly, with a strong jet stream directed across the Atlantic. Three IOPs were conducted in September, to observe a convective band ahead of an upper-level trough, waves on a long trailing cold front, and a warm conveyor belt associated with a secondary cyclone. In November-December six IOPs were conducted, to observe frontal passages and high winds. This period was notable for a number of very strong windstorms passing across the north of the UK, and gave us an opportunity to examine bent-back warm fronts in the southern quadrant of these storms where the strongest winds are found. The case studies fell into two basic patterns. In the majority of cases, dropsonde legs at high level were used to obtain a cross-section of winds and thermodynamic structure (e.g. across a front), followed by in situ legs at lower levels (generally where the temperature was between 0 and -10°) to examine microphysical processes, especially ice multiplication and the extent of supercooled water

  7. Wheel Diameter and Speedometer Reading

    Science.gov (United States)

    Murray, Clifton

    2010-01-01

    Most introductory physics students have seen vehicles with nonstandard wheel diameters; some may themselves drive "low-rider" cars or "big-wheel" pickup trucks. But how does changing wheel diameter affect speedometer readout for a given speed? Deriving the answer can be followed readily by students who have been introduced to rotation, and it…

  8. Sunsets and Solar Diameter Measurement

    Science.gov (United States)

    Sigismondi, Costantino

    2012-03-01

    A sunset over the sea surface offers the possibility to chronometrate a solar transit across the horizon. The vertical solar diameter is proportional to the duration of the sunset, the cosine of the azimuth and the cosine of the latitude of the observing site. The same formula applies to every circle of equal height, called in arabic almucantarat, and it is exploited in the measurements of the solar diameter made with the Danjon's solar astrolabes. The analogies between sunsets and astrolabes observations are presented, showing advantages and sources of errors of these methods of solar astrometry.

  9. Diameter Measurement in Bald Cypress

    Science.gov (United States)

    Bernard R. Parresol; James E. Hotvedt

    1990-01-01

    The usual practice of measuring diameter at 4.5 feet ( 1.3 m) or Dbh is meaningless in wetland tree species such as bald cypress (Taxodium distichum (L.) Rich.), due to the presence of fluted basal swells. Since buttress dimensions usually have no consistent relation to volume or form in the tree, the current practice among...

  10. High voltage variable diameter insulator

    Science.gov (United States)

    Vanecek, David L.; Pike, Chester D.

    1984-01-01

    A high voltage feedthrough assembly (10) having a tubular insulator (15) extending between the ground plane ring (16) and the high voltage ring (30). The insulator (15) is made of Pyrex and decreases in diameter from the ground plane ring (16) to the high voltage ring (30), producing equipotential lines almost perpendicular to the wall (27) of the insulator (15) to optimize the voltage-holding capability of the feedthrough assembly (10).

  11. Reproducibility of Abdominal Aortic Aneurysm Diameter Measurement and Growth Evaluation on Axial and Multiplanar Computed Tomography Reformations

    Energy Technology Data Exchange (ETDEWEB)

    Dugas, Alexandre; Therasse, Eric; Kauffmann, Claude; Tang, An [University of Montreal, Department of Radiology, Centre Hospitalier de l' Universite de Montreal (CHUM) and CHUM Research Center (CRCHUM) (Canada); Elkouri, Stephane [University of Montreal, Department of Surgery, Centre Hospitalier de l' Universite de Montreal (CHUM) (Canada); Nozza, Anna [Institut de Cardiologie de Montreal, Montreal Heart Institute Coordinating Centre (Canada); Giroux, Marie-France; Oliva, Vincent L.; Soulez, Gilles, E-mail: gilles.soulez.chum@ssss.gouv.qc.ca [University of Montreal, Department of Radiology, Centre Hospitalier de l' Universite de Montreal (CHUM) and CHUM Research Center (CRCHUM) (Canada)

    2012-08-15

    Purpose: To compare different methods measuring abdominal aortic aneurysm (AAA) maximal diameter (Dmax) and its progression on multidetector computed tomography (MDCT) scan. Materials and Methods: Forty AAA patients with two MDCT scans acquired at different times (baseline and follow-up) were included. Three observers measured AAA diameters by seven different methods: on axial images (anteroposterior, transverse, maximal, and short-axis views) and on multiplanar reformation (MPR) images (coronal, sagittal, and orthogonal views). Diameter measurement and progression were compared over time for the seven methods. Reproducibility of measurement methods was assessed by intraclass correlation coefficient (ICC) and Bland-Altman analysis. Results: Dmax, as measured on axial slices at baseline and follow-up (FU) MDCTs, was greater than that measured using the orthogonal method (p = 0.046 for baseline and 0.028 for FU), whereas Dmax measured with the orthogonal method was greater those using all other measurement methods (p-value range: <0.0001-0.03) but anteroposterior diameter (p = 0.18 baseline and 0.10 FU). The greatest interobserver ICCs were obtained for the orthogonal and transverse methods (0.972) at baseline and for the orthogonal and sagittal MPR images at FU (0.973 and 0.977). Interobserver ICC of the orthogonal method to document AAA progression was greater (ICC = 0.833) than measurements taken on axial images (ICC = 0.662-0.780) and single-plane MPR images (0.772-0.817). Conclusion: AAA Dmax measured on MDCT axial slices overestimates aneurysm size. Diameter as measured by the orthogonal method is more reproducible, especially to document AAA progression.

  12. 7 CFR 51.2656 - Diameter.

    Science.gov (United States)

    2010-01-01

    ... Standards for Grades for Sweet Cherries 1 Definitions § 51.2656 Diameter. Diameter means the greatest dimension measured at right angles to a line from the stem to the blossom end of the cherry. ...

  13. Height - Diameter predictive equations for Rubber (Hevea ...

    African Journals Online (AJOL)

    BUKOLA

    ABSTRACT. The importance of calibrating models on height-diameter relationship can never be over emphasized in predicting mean total height for trees when only diameter at breast height is measured traditionally. This study has evaluated a set of height-diameter models from twenty plots of Hevea brasilliensis plantation ...

  14. 7 CFR 51.320 - Diameter.

    Science.gov (United States)

    2010-01-01

    ... Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE REGULATIONS AND STANDARDS UNDER THE AGRICULTURAL MARKETING ACT OF 1946... Standards for Grades of Apples Definitions § 51.320 Diameter. When measuring for minimum size, “diameter...

  15. Height - Diameter predictive equations for Rubber (Hevea ...

    African Journals Online (AJOL)

    BUKOLA

    Keywords: height-diameter equations, allometric models, predictive equations, sigmoidal curve. INTRODUCTION. Among pertinent tree characteristics for quantitative tree measurements and reasonable prediction are diameter at breast (dbh) and height. They proffer logistic data for modeling and futuristic prediction for ...

  16. Diameter preserving linear maps and isometries, II

    Indian Academy of Sciences (India)

    In this paper we study diameter preserving mappings on spaces of affine functions. Precisely, let S be a compact convex set in a locally convex Hausdorff space and let eЕSЖ be the space of all (real or complex) continuous affine functions on S. We are interested in linear bijections on eЕSЖ which preserve the diameter of ...

  17. Femoral head diameter in the Malaysian population.

    Science.gov (United States)

    Lee, Chee Kean; Kwan, Mun Keong; Merican, Azhar Mahmood; Ng, Wuey Min; Saw, Lim Beng; Teh, Kok Kheng; Krishnan, Manoharan; Ramiah, Ramanathan

    2014-08-01

    Hip arthroplasty is commonly performed worldwide. The objective of this study was to determine the diameter of the femoral head in the Malaysian population in relation to gender and race (i.e. among Malay, Chinese and Indian patients). This was a retrospective cross-sectional study performed between January 1995 and December 2006, evaluating the femoral head diameters of all patients aged 50 years and above who underwent hemiarthroplasty at two major hospitals in Malaysia. A total of 945 femoral heads (663 women, 282 men) were evaluated. The mean age of the patients in our cohort was 75.2 ± 9.4 (range 50-101) years. The mean femoral head diameter (with intact articular cartilage) was 44.9 ± 3.2 (range 38-54) mm. In our study, men had a significantly larger mean femoral head diameter than women (47.7 ± 2.8 mm vs. 43.7 ± 2.4 mm; p Chinese ethnicity were also found to have significantly larger femoral head diameters, when compared among the three races studied (p Malaysians have a mean femoral head diameter of 44.9 ± 3.2 mm. Among our patients, Chinese patients had a significantly larger femoral head size than Malay and Indian patients. We also found that, in our cohort, men had significantly larger femoral head diameters than women.

  18. Appendiceal diameter: CT versus sonographic measurements

    Energy Technology Data Exchange (ETDEWEB)

    Orscheln, Emily S. [University of Cincinnati Medical Center, Department of Radiology, Cincinnati, OH (United States); Trout, Andrew T. [Cincinnati Children' s Hospital Medical Center, Department of Radiology, Cincinnati, OH (United States)

    2016-03-15

    Ultrasound and CT are the dominant imaging modalities for assessment of suspected pediatric appendicitis, and the most commonly applied diagnostic criterion for both modalities is appendiceal diameter. The classically described cut-off diameter for the diagnosis of appendicitis is 6 mm when using either imaging modality. To demonstrate the fallacy of using the same cut-off diameter for both CT and US in the diagnosis of appendicitis. We conducted a retrospective review of patients younger than 18 years who underwent both US and CT of the appendix within 24 h. The shortest transverse dimension of the appendix was measured at the level of the proximal, mid and distal appendix on US and CT images. We compared mean absolute difference in appendiceal diameter between US and CT, using the paired t-test. We reviewed exams of 155 children (58.7% female) with a mean age of 11.3 ± 4.2 years; 38 of the children (24.5%) were diagnosed with appendicitis. The average time interval between US and CT was 7.0 ± 5.4 h. Mean appendiceal diameter measured by CT was significantly larger than that measured by US in cases without appendicitis (5.3 ± 1.0 mm vs. 4.7 ± 1.1 mm, P < 0.0001) and in cases with appendicitis (8.3 ± 2.2 mm vs. 7.0 ± 2.0 mm, P < 0.0001). Mean absolute diameter difference at any location along the appendix was 1.3-1.4 mm in normal appendices and 2 mm in cases of appendicitis. Measured appendiceal diameter differs between US and CT by 1-2 mm, calling into question use of the same diameter cut-off (6 mm) for both modalities for the diagnosis of appendicitis. (orig.)

  19. Age and Aortic Diameters in Pilots.

    Science.gov (United States)

    Akın, Ahmet; Ozturk, Cengiz; Aparci, Mustafa; Cakmak, Tolga; Metin, Suleyman; Balta, Sevket; Sen, Ahmet

    2015-12-01

    Pilots are exposed to various physical and hemodynamic stresses during flight. Aortic dilatation may be one of the important consequences of flight-related stress. In this study, we evaluated whether or not variation in aortic diameter was associated with the type of aircraft and the age of pilots. Medical records of 87 jet aircraft pilots (JP) (mean age = 30.0 ± 7.0 years) and 65 non-jet aircraft pilots (NJP) (mean age = 32.63 ± 5.7) were reviewed. Echocardiographic diameters of the aortic sinus (AoS) and ascending aorta (AoAsc) were measured using standard echo probe positions. Aortic diameters were not statistically different between JP and NJP. Regression analysis revealed that the diameters of the AoS (R = 0.484, R(2) = 0.234, p age in the JP group. Whereas, there was not any relationship found between age and the diameters of the AoS and AoAsc in the NJP group. Jet pilots had aortic enlargement as they became older in contrast to the NJP group. Although the aortic diameters were not within the critical ranges in the JP group, these results could suggest that flight-related stresses might result in acute aortic syndromes in the long term. Reprint & Copyright © 2015 Association of Military Surgeons of the U.S.

  20. DiameterJ: A validated open source nanofiber diameter measurement tool.

    Science.gov (United States)

    Hotaling, Nathan A; Bharti, Kapil; Kriel, Haydn; Simon, Carl G

    2015-08-01

    Despite the growing use of nanofiber scaffolds for tissue engineering applications, there is not a validated, readily available, free solution for rapid, automated analysis of nanofiber diameter from scanning electron microscope (SEM) micrographs. Thus, the goal of this study was to create a user friendly ImageJ/FIJI plugin that would analyze SEM micrographs of nanofibers to determine nanofiber diameter on a desktop computer within 60 s. Additional design goals included 1) compatibility with a variety of existing segmentation algorithms, and 2) an open source code to enable further improvement of the plugin. Using existing algorithms for centerline determination, Euclidean distance transforms and a novel pixel transformation technique, a plugin called "DiameterJ" was created for ImageJ/FIJI. The plugin was validated using 1) digital synthetic images of white lines on a black background and 2) SEM images of nominally monodispersed steel wires of known diameters. DiameterJ analyzed SEM micrographs in 20 s, produced diameters not statistically different from known values, was over 10-times closer to known diameter values than other open source software, provided hundreds of times the sampling of manual measurement, and was hundreds of times faster than manual assessment of nanofiber diameter. DiameterJ enables users to rapidly and thoroughly determine the structural features of nanofiber scaffolds and could potentially allow new insights to be formed into fiber diameter distribution and cell response. Published by Elsevier Ltd.

  1. Directed growth of diameter-tunable nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Ozturk, Birol; Talukdar, Ishan; Flanders, Bret N [Department of Physics, Oklahoma State University, 145 Physical Sciences II, Stillwater, OK 74078 (United States)

    2007-09-12

    This study characterizes a method for controlling the nanowire diameter in the directed electrochemical nanowire assembly technique, where alternating voltages applied to electrodes in simple salt solutions induce the crystallization of metallic wires. Dendritic solidification is identified as an important component of this technique. A characteristic of dendritic solidification is that the growth velocity and tip radius are anti-correlated. This relationship is exploited here to realize diameter-tunable nanowire growth. The experimental parameter that provides this control is {omega}, the frequency of the alternating voltage. Increasing {omega} effectively steepens the metal cation concentration gradient at the wire-solution interface, thereby increasing the growth velocity of the wire. For indium wires, increasing {omega} from 0.5 to 3.5 MHz increases their growth velocity from 11 to 78 {mu}m s{sup -1} and reduces their diameter from 770 to 114 nm. Gold wires exhibit diameter-tunability that ranges from 150 nm to 45 nm. Thus, it is possible to tune the wire diameter from the microscale down to the nanoscale. Moreover, this control is a consequence of non-stationary dendritic growth, which distinguishes this process from most previously studied examples of dendritic solidification.

  2. Collagen fibril diameter and leather strength.

    Science.gov (United States)

    Wells, Hannah C; Edmonds, Richard L; Kirby, Nigel; Hawley, Adrian; Mudie, Stephen T; Haverkamp, Richard G

    2013-11-27

    The main structural component of leather and skin is type I collagen in the form of strong fibrils. Strength is an important property of leather, and the way in which collagen contributes to the strength is not fully understood. Synchrotron-based small angle X-ray scattering (SAXS) is used to measure the collagen fibril diameter of leather from a range of animals, including sheep and cattle, that had a range of tear strengths. SAXS data were fit to a cylinder model. The collagen fibril diameter and tear strength were found to be correlated in bovine leather (r(2) = 0.59; P = 0.009), with stronger leather having thicker fibrils. There was no correlation between orientation index, i.e., fibril alignment, and fibril diameter for this data set. Ovine leather showed no correlation between tear strength and fibril diameter, nor was there a correlation across a selection of other animal leathers. The findings presented here suggest that there may be a different structural motif in skin compared with tendon, particularly ovine skin or leather, in which the diameter of the individual fibrils contributes less to strength than fibril alignment does.

  3. Diameter effect on critical heat flux

    Energy Technology Data Exchange (ETDEWEB)

    Tanase, A. [University of Ottawa, Department of Mechanical Engineering, Ottawa, ON (Canada)], E-mail: atana052@uottawa.ca; Cheng, S.C. [University of Ottawa, Department of Mechanical Engineering, Ottawa, ON (Canada); Groeneveld, D.C. [University of Ottawa, Department of Mechanical Engineering, Ottawa, ON (Canada); Chalk River Laboratories, Atomic Energy of Canada Ltd., Chalk River, ON (Canada); Shan, J.Q. [Department of Nuclear Engineering, Xi' an Jiaotong University (China)

    2009-02-15

    The critical heat flux look-up table (CHF LUT) is widely used to predict CHF for various applications, including design and safety analysis of nuclear reactors. Using the CHF LUT for round tubes having inside diameters different from the reference 8 mm involves conversion of CHF to 8 mm. Different authors [Becker, K.M., 1965. An Analytical and Experimental Study of Burnout Conditions in Vertical Round Ducts, Aktiebolaget Atomenergie Report AE 177, Sweden; Boltenko, E.A., et al., 1989. Effect of tube diameter on CHF at various two phase flow regimes, Report IPE-1989; Biasi, L., Clerici, G.C., Garriba, S., Sala, R., Tozzi, A., 1967. Studies on Burnout, Part 3, Energia Nucleare, vol. 14, pp. 530-536; Groeneveld, D.C., Cheng, S.C., Doan, T., 1986. AECL-UO critical heat flux look-up table. Heat Transfer Eng., 7, 46-62; Groeneveld et al., 1996; Hall, D.D., Mudawar, I., 2000. Critical heat flux for water flow in tubes - II subcooled CHF correlations. Int. J. Heat Mass Transfer, 43, 2605-2640; Wong, W.C., 1996. Effect of tube diameter on critical heat flux, MaSC dissertation, Ottawa Carleton Institute for Mechanical and Aeronautical Engineering, University of Ottawa] have proposed several types of correlations or factors to describe the diameter effect on CHF. The present work describes the derivation of new diameter correction factor and compares it with several existing prediction methods.

  4. Total domination in graphs with diameter 2

    DEFF Research Database (Denmark)

    Desormeaux, Wyatt J.; Haynes, Teresa W.; Henning, Michael A.

    2014-01-01

    The total domination number γt(G) of a graph G is the minimum cardinality of a set S of vertices, so that every vertex of G is adjacent to a vertex in S. In this article, we determine an optimal upper bound on the total domination number of a graph with diameter 2. We show that for every graph G ...... on n vertices with diameter 2, γt(G)≤1+nln(n). This bound is optimal in the sense that given any ε>0, there exist graphs G with diameter 2 of all sufficiently large even orders n such that γt(G)>(14+ε)nln(n)....

  5. Diameter preserving linear maps and isometries, II

    Indian Academy of Sciences (India)

    We study linear bijections of simplex spaces A ( S ) which preserve the diameter of the range, that is, the seminorm ϱ ( f ) = sup { | f ( x ) − f ( y ) | : x , y ∈ S } . Author Affiliations. Félix Cabello Sánchez1. Departamento de Matemáticas, Universidad de Extremadura, Avenida de Elvas 06071- Badajoz, Spain. Dates. Manuscript ...

  6. Numerical Analysis of Large Diameter Butterfly Valve

    Science.gov (United States)

    Youngchul, Park; Xueguan, Song

    In this paper, a butterfly valve with the diameter of 1,800 mm was studied. Three-dimensional numerical technique by using commercial code CFX were conducted to observe the flow patterns and to measure flow coefficient, hydrodynamic torque coefficient and so on, when the large butterfly valve operated with various angles and uniform incoming velocity.

  7. Ultrasonic measurement of biparietal diameter and

    African Journals Online (AJOL)

    Summary. Our objective was to verify ultrasonic measurement of biparietal diameter and femur in foetal age determination in the second and third trimester of pregnancy. The prospec- tive cross sectional study was carried out at the ultrasound department of Aberdeen Maternity Hospital Scotland. The study population ...

  8. On finding minimum-diameter clique trees

    Energy Technology Data Exchange (ETDEWEB)

    Blair, J.R.S. (Tennessee Univ., Knoxville, TN (United States). Dept. of Computer Science); Peyton, B.W. (Oak Ridge National Lab., TN (United States))

    1991-08-01

    It is well-known that any chordal graph can be represented as a clique tree (acyclic hypergraph, join tree). Since some chordal graphs have many distinct clique tree representations, it is interesting to consider which one is most desirable under various circumstances. A clique tree of minimum diameter (or height) is sometimes a natural candidate when choosing clique trees to be processed in a parallel computing environment. This paper introduces a linear time algorithm for computing a minimum-diameter clique tree. The new algorithm is an analogue of the natural greedy algorithm for rooting an ordinary tree in order to minimize its height. It has potential application in the development of parallel algorithms for both knowledge-based systems and the solution of sparse linear systems of equations. 31 refs., 7 figs.

  9. 29 mm Diameter Test Target Design Report

    Energy Technology Data Exchange (ETDEWEB)

    Woloshun, Keith Albert [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Dale, Gregory E. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Olivas, Eric Richard [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Naranjo, Angela Carol [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Romero, Frank Patrick [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-08-15

    The Northstar target for Mo99 production is made up of Mo100 disks in a stack separated by coolant gaps for helium flow. A number of targets have been tested at ANL for both production of Mo99 and for thermal-hydraulic performance. These have all been with a 12 mm diameter target, even while the production goals have increased the diameter to now 29 mm. A 29 mm diameter target has been designed that is consistent with the ANL beam capabilities and the capabilities of the helium circulation system currently in use at ANL. This target is designed for 500 μA at 35 MeV electrons. While the plant design calls for 42 MeV, the chosen design point is more favorable and higher power given the limits of the ANL accelerator. The intended beam spot size is 12 mm FWHM, but the thermal analysis presented herein conservatively assumed a 10 mm FWHM beam, which results in a 44% higher beam current density at beam center.

  10. 29 mm Diameter Target Test Report

    Energy Technology Data Exchange (ETDEWEB)

    Woloshun, Keith Albert [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Olivas, Eric Richard [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Dale, Gregory E. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Naranjo, Angela Carol [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Romero, Frank Patrick [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Chemerisov, Sergey [Argonne National Lab. (ANL), Argonne, IL (United States); Gromov, Roman [Argonne National Lab. (ANL), Argonne, IL (United States)

    2017-10-23

    After numerous delays, the test of the 29 mm diameter target was conducted on 8/18/2017. The complete target design report, dated 8/15/2016, is reproduced below for completeness. This describes in detail the 10 disk target with varying thickness disks. The report presents and discusses the test results. In brief summary, there appears to have been multiple instrumentation errors. Measured temperatures, pressures and IR camera window temperature measurement are all suspect. All tests were done at 35 MeV, with 171 μA current, or 6 kW of beam power.

  11. Variable diameter wind turbine rotor blades

    Science.gov (United States)

    Jamieson, Peter McKeich; Hornzee-Jones, Chris; Moroz, Emilian M.; Blakemore, Ralph W.

    2005-12-06

    A system and method for changing wind turbine rotor diameters to meet changing wind speeds and control system loads is disclosed. The rotor blades on the wind turbine are able to adjust length by extensions nested within or containing the base blade. The blades can have more than one extension in a variety of configurations. A cable winching system, a hydraulic system, a pneumatic system, inflatable or elastic extensions, and a spring-loaded jack knife deployment are some of the methods of adjustment. The extension is also protected from lightning by a grounding system.

  12. Factors affecting common bile duct diameter.

    Science.gov (United States)

    Daradkeh, Salam; Tarawneh, Emad; Al-Hadidy, Azmy

    2005-01-01

    The purpose of the study was to see the effect of age, sex, body mass index, previous cholecystectomy, hepatomegaly and fasting status on the common bile duct diameter. A series of 463 patients, 283 females and 180 males, with no hepatobiliary or pancreatic pathology were included in this study, the mean age was 45 +/- 16 years. Their age, sex, weight, height, fasting status and previous cholecystectomy was assessed and recorded by a physician prior to ultrasound examination. All patients were examined by real-time ultrasound to see if there was any pathology in the hepatobiliary and pancreatic area. Those with history of common bile duct exploration, endoscopic sphincterotomy or with previous history of cholecystectomy of less than 6 months and patients with common bile duct pathology were excluded from the study. The midportion of the common bile duct was taken as a fixed measurement for all patients and the size of the liver was also recorded. Analysis of variance as part of SPSS statistical package was used where common bile duct was considered a dependent variable, while sex, fasting status, hepatomegaly and previous cholecystectomy were considered to be independent variables, age and sex were considered as co-variants. The factors found to be significantly affecting the diameter of the common bile duct (P<0.05) were age, previous cholecystectomy and body mass index. If the CBD dilatation can not be explained by age, previous cholecystectomy and BMI, a pathology causing obstruction should be ruled out.

  13. Sagittal Abdominal Diameter: Application in Clinical Practice

    Directory of Open Access Journals (Sweden)

    Thaís Da Silva-Ferreira

    2014-05-01

    Full Text Available Excess visceral fat is associated with cardiovascular risk factors. Sagittal abdominal diameter (SAD has recently been highlighted as an indicator of abdominal obesity, and also may be useful in predicting cardiovascular risk. The purpose of the present study was to review the scientific literature on the use of SAD in adult nutritional assessment. A search was conducted for scientific articles in the following electronic databases: SciELO , MEDLINE (PubMed and Virtual Health Library. SAD is more associated with abdominal fat (especially visceral, and with different cardiovascular risk factors, such as, insulin resistance, blood pressure, and serum lipoproteins than the traditional methods of estimating adiposity, such as body mass index and waist-to-hip ratio. SAD can also be used in association with other anthropometric measures. There are still no cut-off limits established to classify SAD as yet. SAD can be an alternative measure to estimate visceral adiposity. However, the few studies on this diameter, and the lack of consensus on the anatomical site to measure SAD, are obstacles to establish cut-off limits to classify it.

  14. Recent results on the solar diameter

    Science.gov (United States)

    Wittmann, A. D.; Alge, E.; Bianda, M.

    1991-10-01

    Using optically identical telescopes at different sites, the solar diameter is measured with a drift-scan technique. In order to investigate the cause of the observed fluctuations, observations made simultaneously by different observers at the same telescope are compared as are observations made simultaneously at two different sites. It is found that the mean error of a single drift time measurement is +/-0.08 s (or +/- 1.1 arcsec) at Izana and +/-0.11 s (or +/- 1.7 arcsec) at Locarno; this closely corresponds to the angular resolution at those two sites under normal seeing conditions. No correlation is found between observations at different sites; a significant correlation exists, however, between observations made simultaneously by different observers at the same site. This indicates that most of the observed fluctuations are due to atmospheric effects rather than personality effects. The mean solar semidiameter derived from a total of 1122 observations made in 1990 is R = (960.56 +/-0.03) arcsec; this may be compared with R = (960.32 +/-0.02) arcsec which is obtained from a reanalysis of 1773 observations made in 1981. Although a small residual increase of the solar diameter during the last 10 years seems to be indicated, most - if not all - of the observed varitions are due to variable seeing conditions, and there is still no conclusive evidence for a genuine solar variation with amplitudes in excess of about +/-0.3 arcsec.

  15. Completion systems for large diameter casing

    Energy Technology Data Exchange (ETDEWEB)

    Weinch, J.B.; Lorenz, M. (Baker Sand Control (US)); (Leggett, D. (Baker Sand Control Services Pta. Ltd. (SG)))

    1988-01-01

    Completion operations, for oil and gas wells, are usually performed in casing sizes not exceeding 13-3/8 in. (34.0 cm) with the majority of completions being performed in 9-5/8 in. (24.5 cm) and smaller. As such, the availability of completion equipment, for large diameter casings, becomes extremely limited or nonexistent. Occasionally, conditions may exist which require the completion to be designed in a casing size larger than 13-3/8 in. (34.0 cm). In order to complete in these casing sizes, special equipment must be designed. This paper discusses the design criteria, development, and subsequent use of perforating and gravel pack equipment generated for use in 20 in. (50.8 cm) casing.

  16. Fire protection covering for small diameter missiles

    Science.gov (United States)

    Riccitiello, S. R.; Sawko, P. M. (Inventor)

    1979-01-01

    Flexible intumescent protection sheeting of unusually uniform thickness were prepared from epoxy-polysulfide compositions, containing microfibers and the ammonium salt of 1,4-nitroaniline-2-sulfonic acid, as disclosed in U.S. Pat. No. 3,663,464, except that an ammonium salt particle size in the order of 5 to 8 microns and a fiber size of about 1/128th inch in length and 3 to 5 microns in diameter were found critical to obtain the required density of 1.46 to 1.50 g/cc. The insulation sheeting was prepared by a continuous process involving vacuum mixing, calendering, and curing under very strict conditions which depend to some extent upon the thickness of the sheet produced.

  17. Five meter diameter conical furlable antenna

    Science.gov (United States)

    Fortenberry, J. W.; Freeland, R. E.; Moore, D. M.

    1976-01-01

    An investigation was made to demonstrate that a 5-meter-diameter, furlable, conical reflector antenna utilizing a line source feed can be fabricated utilizing composite materials and to prove that the antenna can function mechanically and electrically as prototype flight hardware. The design, analysis, and testing of the antenna are described. An RF efficiency of 55% at 8.5 GHz and a surface error of 0.64 mm rms were chosen as basic design requirements. Actual test measurements yielded an efficiency of 53% (49.77 dB gain) and a surface error of 0.61 mm rms. Atmospherically induced corrosion of the reflector mesh resulted in the RF performance degradation. An assessment of the antenna as compared to the current state of the art technology was made. This assessment included cost, surface accuracy and RF performance, structural and mechanical characteristics, and possible applications.

  18. Development of large diameter carbon monofilament

    Science.gov (United States)

    Jacob, B.; Neltri, R. D.

    1973-01-01

    A process for preparing large diameter carbon-boron monofilament was developed. The process involves chemical vapor depositing a carbon-boron alloy monofilament from a BCl3, CH4, and H2 gas mixture onto a carbon substrate. Amorphous alloys were formed when gaseous mixtures containing greater than 20 percent methane (80 percent BCl3) were used. The longest uninterrupted lengths of carbon-boron monofilament were produced using a CH4/BCl3 gas ratio of 2.34. It was found that the properties of the carbon-boron alloy monofilament improved when the carbon substrate was precleaned in chlorine. The highest strength monofilament was attained when a CH4/BCl3 gas volume ratio of 0.44 was 28 million N/sq cm (40 million psi). While the highest strengths were attained in this run, the 0.44 gas ratio and other CH4/BCl3 ratios less than 2.34 would not yield long runs. Runs using these ratios were usually terminated because of a break in the monofilament within the reactor. It is felt better process control could probably be achieved by varying the amount of hydrogen; the BCl3/H2 ratio was kept constant in these studies.

  19. Shiitake mushroom production on small diameter oak logs in Ohio

    Science.gov (United States)

    S.M. Bratkovich

    1991-01-01

    Yields of different strains of shiitake mushrooms (Lentinus edodes) were evaluated when produced on small diameter oak logs in Ohio. Logs averaging between 3-4 inches in diameter were inoculated with four spawn strains in 1985.

  20. Body diameters in 3 - 6 years old children from Plovdiv

    Directory of Open Access Journals (Sweden)

    Tineshev Slavi

    2013-01-01

    Full Text Available The purpose of the research is to analyze the body diameters in 3-6 year old children. The biacromial diameters were taken as well as the two chest diameters, the bicristal and bitrohanterial diameters in 316 children (157 boys and 159 girls 3, 4, 5 and 6 years of age attending kindergarten in Plovdiv. The analysis shows that all diameters, with the exception of the bitrohanterial have higher values in boys. The absolute year's increment of the diameters is greater in girls. The growth velocity of the researched features is greatest at the age of 3-4 and 4-5, decreasing at different rates for the different features at the age of 5-6. The only exception is the sagittal chest diameter in both sexes and the bitrohanterial diameters in girls.

  1. Predicting fir trees stem diameters using Artificial Neural Network ...

    African Journals Online (AJOL)

    The system proposed in this paper can be applied in forest inventory making an accurate estimate of the volume of a sample tree based on only two diameter measurements (stump diameter, d0.3 and diameter at breast height, d1.3) and an estimate of the total tree height (h). Training of the ANNs was achieved through the ...

  2. Sonographic assessment of the portal vein diameter in apparently ...

    African Journals Online (AJOL)

    Conclusion: This study found the mean values of PV diameter in apparently healthy adults in our environment to be 9.60 ±. 1.41mm and that PV diameter ... Keywords: Portal vein diameter, sonography, Nigerian population, healthy adults. ... architecture that leads to enlargement of extrahepatic and intrahepatic portal ...

  3. Height-diameter equations for thirteen midwestern bottomland hardwood species

    Science.gov (United States)

    Kenneth C. Colbert; David R. Larsen; James R. Lootens

    2002-01-01

    Height-diameter equations are often used to predict the mean total tree height for trees when only diameter at breast height (dbh) is measured. Measuring dbh is much easier and is subject to less measurement error than total tree height. However, predicted heights only reflect the average height for trees of a particular diameter. In this study, we present a set of...

  4. Parametric Probability Distribution Functions for Axon Diameters of Corpus Callosum

    OpenAIRE

    Sepehrband, Farshid; Alexander, Daniel C; Clark, Kristi A.; Kurniawan, Nyoman D; Yang, Zhengyi; Reutens, David C.

    2016-01-01

    Axon diameter is an important neuroanatomical characteristic of the nervous system that alters in the course of neurological disorders such as multiple sclerosis. Axon diameters vary, even within a fiber bundle, and are not normally distributed. An accurate distribution function is therefore beneficial, either to describe axon diameters that are obtained from a direct measurement technique (e.g., microscopy), or to infer them indirectly (e.g., using diffusion-weighted MRI). The gamma distribu...

  5. Atom-bond connectivity index and diameter of graphs

    Directory of Open Access Journals (Sweden)

    Lin WU

    2016-12-01

    Full Text Available For further study of the numerous nice properties of topological indices in physical and chemical fields, it is worth considering the relation between a degree-based index and a distance-based index. With the fact that diameter is an invariant based on distance, the relations between atom-bond connectivity index, diameter in trees and unicyclic graphs are studied. Based on relative lemma, the relation between atom-bond connectivity index and diameter in tree and unicyclic graphs is investigated, then the sharp lower bounds of the difference of index and diameter are given.

  6. Dataset for the validation and use of DiameterJ an open source nanofiber diameter measurement tool

    Directory of Open Access Journals (Sweden)

    Nathan A. Hotaling

    2015-12-01

    Full Text Available DiameterJ is an open source image analysis plugin for ImageJ. DiameterJ produces ten files for every image that it analyzes. These files include the images that were analyzed, the data to create histograms of fiber radius, pore size, fiber orientation, and summary statistics, as well as images to check the output of DiameterJ. DiameterJ was validated with 130 in silico-derived, digital, synthetic images and 24 scanning electron microscope (SEM images of steel wire samples with a known diameter distribution. Once validated, DiameterJ was used to analyze SEM images of electrospun polymeric nanofibers, including a comparison of different segmentation algorithms. In this article, all digital synthetic images, SEM images, and their segmentations are included. Additionally, DiameterJ’s raw output files, and processed data is included for the reader. The data provided herein was used to generate the figures in DiameterJ: A Validated Open Source Nanofiber Diameter Measurement Tool [1], where more discussion can be found.

  7. Growth process and diameter structure of Pinus tabulaeformis forest ...

    African Journals Online (AJOL)

    Using stem analysis method, the biomass, growing process and diameter structure of 21-year shady and sunny slope Pinus tabulaeformis forest were investigated in hilly loess-gully region. Results showed that there were distinct difference in the indexes, tree height, diameter at breast height (DBH) and timber volume ...

  8. Equipment for testing beds in small-diameter deep wells

    Energy Technology Data Exchange (ETDEWEB)

    Varlamov, P.S.; Lopatkin, O.P.; Snezhko, M.P.

    1978-03-01

    A description is given of the technical specifications of specially designed drill stem testor 80 mm in diameter which was developed for testing horizons in deep boreholes of small diameter. Also described is the operational efficiency of this equipment and the economic advantages derived from it.

  9. Relationships between stem diameter at breast height (DBH), tree ...

    African Journals Online (AJOL)

    Trees show considerable variation and flexibility in their size of crowns, height and stem diameter at breast height (dbh). Dbh has been used as predictor variables in diameter and height growth equations. Relationships between dbh, tree height, crown length, crown height and crown ratio of Vitellaria paradoxa were ...

  10. Parsimonious Crown Diameter Prediction Models for Tectona Grandis

    African Journals Online (AJOL)

    Parsimonious Crown Diameter Prediction Models for Tectona Grandis (Linn f Verbenaceae). FS Popo-ola, BA Oyebade,. Abstract. Tree crown is one complement of net primary production and its dimensions reflect general tree health. Crown diameter is often used as an important predictor variable for tree growth equation.

  11. Generalized height-diameter models for Populus tremula L. stands ...

    African Journals Online (AJOL)

    Using permanent sample plot data, selected tree height and diameter functions were evaluated for their predictive abilities for Populus tremula stands in Turkey. Two sets of models were evaluated. The first set included five models for estimating height as a function of individual tree diameter; the second set also included six ...

  12. Diameter Growth, Survival, and Volume Estimates for Missouri Trees

    Science.gov (United States)

    Stephen R. Shifley; W. Brad Smith

    1982-01-01

    Measurements of more than 20,000 Missouri trees were summarized by species and diameter class into tables of mean annual diameter growth, annual probability of survival, net cubic foot volume, and net board foot volume. In the absence of better forecasting techniques, this information can be utilized to project short-term changes for Missouri trees, inventory plots,...

  13. Sex differences in diameter of the coronary sinus ostium: Correlation ...

    African Journals Online (AJOL)

    Diameter of the coronary sinus ostium is important in the designing of cannulation devices used in cardiac resynchronization therapy and percutaneous mitral valve annuloplasty. Population variation of the diameter may account for the failure rate of these procedures. Studies of the coronary sinus ostium from African ...

  14. Sex Dimorphism of the Heart Diameters and Cardiothoracic Ratios ...

    African Journals Online (AJOL)

    Objective: To determine gender associated differences in the cardiothoracic ratio (CTR) and heart diameters in a normal Nigerian population. Subject and Method: The normal heart diameters and cardiothoracic ratios were measured from posteroanterior (PA) chest radiographs of healthy 510 male and 508 female ...

  15. Growth process and diameter structure of Pinus tabulaeformis forest ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-10-19

    Oct 19, 2009 ... Using stem analysis method, the biomass, growing process and diameter structure of 21-year shady and sunny slope Pinus tabulaeformis forest were investigated in hilly loess-gully region. Results showed that there were distinct difference in the indexes, tree height, diameter at breast height (DBH).

  16. Influence of high intensity ultrasound with different probe diameter ...

    African Journals Online (AJOL)

    The main goal of this research is to analyze the influence of ultrasonic probe diameters (7 and 10 mm) of high-intensity ultrasound with constant frequency (30 kHz) on the degree of homogenization (variance) of cow milk. Influence of different probe diameters on the physical properties of cow milk was also tested. Changes ...

  17. Lumbar Vertebral Canal Diameters in Adult Ugandan Skeletons ...

    African Journals Online (AJOL)

    Background: Normal values of lumbar vertebral canal diameters are useful in facilitating diagnosis of lumbar vertebral canal stenosis. Various studies have established variation on values between different populations, gender, age, and ethnic groups. Objectives: To determine the lumbar vertebral canal diameters in adult ...

  18. Dental Implant Length and Diameter: A Proposed Classification Scheme.

    Science.gov (United States)

    Al-Johany, Sulieman S; Al Amri, Mohammad D; Alsaeed, Suliman; Alalola, Bassam

    2017-04-01

    To propose a length-and-diameter-based classification scheme for dental implants to standardize terminology in the dental literature and communication between interested parties. This study was mainly based on searching two major resources: published scientific research papers and 14 of the most popular dental implant manufacturers. Indexed databases were searched from January 2004 up to and including February 2016 using the keywords "dental implant length" and "dental implant diameter." Retrieved titles and abstracts were screened, and related full-text articles were reviewed. Full-text articles that clearly stated the terms and measurements of implants used were included and considered for proposing this classification scheme. The initial search for implant diameter and length yielded 1007 and 936 articles, respectively. A total of 85 studies (41 about diameter, 44 about length) were selected and reviewed. The remaining studies (966 about diameter, 892 about length) that did not abide by the eligibility criteria were excluded. The terms "long," "short," "standard," "wide," and "narrow" were the most commonly used terms in the literature. A classification scheme for implants by diameter and length was proposed. Indexed publications contain a variety of terms used by authors to describe diameter and length of dental implants without conformity and standardization. The classification scheme proposed in this article could serve as a reference for interested parties. © 2016 by the American College of Prosthodontists.

  19. Systematic review on success of narrow-diameter dental implants.

    Science.gov (United States)

    Klein, Marc O; Schiegnitz, Eik; Al-Nawas, Bilal

    2014-01-01

    The aim of this systematic review was to determine the survival and success rates of narrow-diameter implants (NDI) in different clinical indications compared to standard diameter implants. Implant diameters were categorized into categories 1 (implant diameters implant diameters 3 to 3.25 mm (Category 2), and 16 articles reporting on implant diameters 3.3 to 3.5 mm (Category 3). The quality of the studies was mostly low with a high risk of bias. Dental implants implants) were one-piece in the edentulous arch and non-loaded frontal region with survival rates between 90.9% and 100%. For dental implants with a diameter between 3.0 and 3.25 mm, most were two-piece implants inserted into narrow tooth gaps without loading and in the frontal region. Survival rates for these implants ranged between 93.8% and 100%. Implants of 3.3 to 3.5 mm were two-piece and were also used in the load-bearing posterior region. Survival rates were between 88.9% and 100%, and success rates ranged between 91.4% and 97.6%. A meta-analysis was conducted for NDI (3.3 to 3.5 mm), which showed no statistically significant difference in implant survival compared to conventional implants with an odds ratio of 1.16 (0.7 to 1.69). Narrow-diameter implants of 3.3 to 3.5 mm are well documented in all indications including load-bearing posterior regions. Smaller implants of 3.0 to 3.25 mm in diameter are well documented only for single-tooth non-load-bearing regions. Mini-implants 1 year and information on patient specific risk factors (bruxism, restoration type) are also missing.

  20. Laser direct writing using submicron-diameter fibers.

    Science.gov (United States)

    Tian, Feng; Yang, Guoguang; Bai, Jian; Xu, Jianfeng; Hou, Changlun; Liang, Yiyong; Wang, Kaiwei

    2009-10-26

    In this paper, a novel direct writing technique using submicron-diameter fibers is presented. The submicron-diameter fiber probe serves as a tightly confined point source and it adopts micro touch mode in the process of writing. The energy distribution of direct writing model is analyzed by Three-Dimension Finite-Difference Time-Domain method. Experiments demonstrate that submicron-diameter fiber direct writing has some advantages: simple process, 350-nm-resolution (lower than 442-nm-wavelength), large writing area, and controllable width of lines. In addition, by altering writing direction of lines, complex submicron patterns can be fabricated.

  1. Heritability of retinal vessel diameters and blood pressure

    DEFF Research Database (Denmark)

    Taarnhøj, Nina C B B; Larsen, Michael; Sander, Birgit

    2006-01-01

    for CRVE, and 0.67 +/- 0.05 microm for AVR. No significant influence on artery or vein diameters was found for gender, smoking, body mass index (BMI), total cholesterol, fasting blood glucose, or 2-hour oral glucose tolerance test values. CONCLUSIONS: In healthy young adults with normal blood pressure...... and blood glucose, variations in retinal blood vessel diameters and blood pressure were predominantly attributable to genetic effects. A genetic influence may have a role in individual susceptibility to hypertension and other vascular diseases. The results suggest that retinal vessel diameters...

  2. Computing Graph Distances Parameterized by Treewidth and Diameter

    OpenAIRE

    Husfeldt, Thore

    2017-01-01

    We show that the eccentricity of every vertex in an undirected graph on n vertices can be computed in time n exp O(k*log(d)), where k is the treewidth of the graph and d is the diameter. This means that the diameter and the radius of the graph can be computed in the same time. In particular, if the diameter is constant, it can be determined in time n*exp(O(k)). This result matches a recent hardness result by Abboud, Vassilevska Williams, and Wang [SODA 2016] that shows that under the Strong E...

  3. Ball lightning diameter-lifetime statistical analysis of SKB databank

    Science.gov (United States)

    Amirov, Anvar Kh; Bychkov, Vladimir L.

    1995-03-01

    Revelation of the significance of diameter as a factor for the lifetime as a parameter for different ways of Ball Lightning (BL) disappearance has been made. Methods for non-parametric regression analysis have been applied for pairs diameter - radiation losses in correspondence to BL disappearance. BL diameter as a factor turned out to be significant for BL life-time in the case of explosion and decay and insignificant in the case of extinction. Dependence logarithm of radiation losses - logarithm of BL volume obtained with the help of nonparametric regression treatment turned out to be different according to BL ways of disappearance.

  4. Porosity Assessment for Different Diameters of Coir Lignocellulosic Fibers

    Science.gov (United States)

    da Luz, Fernanda Santos; Paciornik, Sidnei; Monteiro, Sergio Neves; da Silva, Luiz Carlos; Tommasini, Flávio James; Candido, Verônica Scarpini

    2017-10-01

    The application of natural lignocellulosic fibers (LCFs) in engineering composites has increased interest in their properties and structural characteristics. In particular, the inherent porosity of an LCF markedly affects its density and the adhesion to polymer matrices. For the first time, both open and closed porosities of a natural LCF, for different diameter ranges, were assessed. Fibers extracted from the mesocarp of the coconut fruit were investigated by nondestructive methods of density measurements and x-ray microtomography (microCT). It was found that, for all diameter ranges, the closed porosity is significantly higher than the open porosity. The total porosity increases with diameter to around 60% for coir fibers with more than 503 μm in diameter. The amount and characteristics of these open and closed porosities were revealed by t test and Weibull statistics as well as by microCT.

  5. NEOWISE DIAMETERS AND ALBEDOS V1.0

    Data.gov (United States)

    National Aeronautics and Space Administration — This PDS data set represents a compilation of published diameters, optical albedos, near-infrared albedos, and beaming parameters for minor planets detected by...

  6. Eddy sensors for small diameter stainless steel tubes.

    Energy Technology Data Exchange (ETDEWEB)

    Skinner, Jack L.; Morales, Alfredo Martin; Grant, J. Brian; Korellis, Henry James; LaFord, Marianne Elizabeth; Van Blarigan, Benjamin; Andersen, Lisa E.

    2011-08-01

    The goal of this project was to develop non-destructive, minimally disruptive eddy sensors to inspect small diameter stainless steel metal tubes. Modifications to Sandia's Emphasis/EIGER code allowed for the modeling of eddy current bobbin sensors near or around 1/8-inch outer diameter stainless steel tubing. Modeling results indicated that an eddy sensor based on a single axial coil could effectively detect changes in the inner diameter of a stainless steel tubing. Based on the modeling results, sensor coils capable of detecting small changes in the inner diameter of a stainless steel tube were designed, built and tested. The observed sensor response agreed with the results of the modeling and with eddy sensor theory. A separate limited distribution SAND report is being issued demonstrating the application of this sensor.

  7. Axon diameter mapping in crossing fibers with diffusion MRI

    DEFF Research Database (Denmark)

    Zhang, Hui; Dyrby, Tim B; Alexander, Daniel C

    2011-01-01

    This paper proposes a technique for a previously unaddressed problem, namely, mapping axon diameter in crossing fiber regions, using diffusion MRI. Direct measurement of tissue microstructure of this kind using diffusion MRI offers a new class of biomarkers that give more specific information about...... model to enable axon diameter mapping in voxels with crossing fibers. We show in simulation that the technique can provide robust axon diameter estimates in a two-fiber crossing with the crossing angle as small as 45 degrees. Using ex vivo imaging data, we further demonstrate the feasibility...... tissue than measures derived from diffusion tensor imaging. Most existing techniques for axon diameter mapping assume a single axon orientation in the tissue model, which limits their application to only the most coherently oriented brain white matter, such as the corpus callosum, where the single...

  8. Study of Linearly Polarized Light Measuring Fiber Diameter

    Energy Technology Data Exchange (ETDEWEB)

    Liang Hong, E-mail: lianghong@cuc.edu.cn [School of science, Communication University of China 100024 (China)

    2011-02-01

    The letter discusses a new way to measure fiber diameters, studies the theory of measuring fiber radius using this way, carries out numerical simulation based on this and provides experiment method as well.

  9. Synthesis of very small diameter silica nanofibers using sound waves.

    Science.gov (United States)

    Datskos, Panos; Chen, Jihua; Sharma, Jaswinder

    2014-07-14

    Silica nanofibers of an average diameter ≈30 nm and length ≈100 μm have been synthesized using an unprecedented strategy: sound waves. A new phenomenon, spinning off the nanofibers at silica rod tips, is also observed.

  10. Observations on placentome diameters in gestating West African ...

    African Journals Online (AJOL)

    ADEYEYE

    2015-09-09

    com. Abstract. This study investigated the effect of experimental Trypanosoma brucei infection on the placentome diameter (PD) of twenty four gestating West African dwarf does. The does were randomized into 4 equal groups ...

  11. Diameter constrained reliability of ladders and Spanish fans

    Directory of Open Access Journals (Sweden)

    Cancela Héctor

    2016-01-01

    Full Text Available We are given a graph G = (V, E, terminal set K  V and diameter d > 0. Links fail stochastically and independently with known probabilities. The diameter-constrained reliability (DCR for short, is the probability that the K-diameter is not greater than d in the subgraph induced by non-failed links. The contributions of this paper are two-fold. First, the computational complexity of DCR-subproblems is discussed in terms of the number of terminals k = jKj and diameter d. Here, we prove that when d > 2 the problem is NP-Hard when K = V. Second, we compute the DCR efficiently for Ladders and Spanish Fans. Open problems and trends for future work are discussed in the conclusions.

  12. Improved Design Basis for Laterally Loaded Large Diameter Pile

    DEFF Research Database (Denmark)

    Leth, Caspar Thrane

    with a capacity of 3.6 MW and placed at water depths beyond 25 m. Different foundation solutions have over the years been applied for offshore turbines, but monopiles are currently the most applied foundation type and are typically with a pile diameter of 4-6 m and applied up to a water depth of 25 m...... on the structure and the productivity of the turbine. Current design practice for monopiles are based on p-y curves developed for slender piles with a diameter of 0.6 m. The focus on the structure stiffness has entailed a significant research on the soil-structure interaction for large diameter monopiles....... Comparison of the different approaches shows some discrepancy and conflicting statements, but the main findings can be summarized as: • The standard p-y curves are inadequate to describe the behaviour of lateral loaded large diameter rigid piles. • Initial stiffness of the p-y curves is depended...

  13. Predicting fir trees stem diameters using Artificial Neural Network ...

    African Journals Online (AJOL)

    The aim of this paper is to examine the applicability of Artificial Neural Network models (ANNs), in the prediction of fir trees stem over bark diameters at 5.3, 9.3, 13.3, 17.3, 21.3, 25.3, 29.3 and 33.3 meters above ground. The values of these diameters are necessary for an efficient estimation of a single tree volume using the ...

  14. Perbandingan Unjuk Kerja Kompor Methanol dengan Variasi Diameter Burner

    Directory of Open Access Journals (Sweden)

    Subroto Subroto

    2016-08-01

    Full Text Available Sampai saat ini sebagian masyarakat masih anyak menggunakan minyak tanah sebagai bahan bakar untuk keperluan rumah tangga maupun industri, walaupun harga minyak tanah naik cukup tinggi karena subsidi dari pemerintah dicabut. Untuk mengurangi ketergantungan minyak tanah perlu penggunaan bahan bakar alternatif yaitu methanol. Methanol mempunyai kelebihan mudah didapatkan di lapangan dan dengan harga yang lebih murah dari minyak tanah. Kompor methanol sudah dikenal masyarakat akan tetapi penggunaannya masih sangat terbatas karena unjuk kerjanya masih kurang baik dibandingkan kompor minyak tanah. Penelitian ini bertujuan untuk mengetahui unjuk kerja kompor methanol melalui pengaruh variasi diameter burner.               Penelitian dimulai dengan rancang bangun burner terbuat dari bahan kuningan dengan tiga macam model dengan variasi diameter burner dan tinggi burner maupun jumlah lubang tetap. Pengujian unjuk kerja berdasarkan karakteristik pembakaran dilakukan melalui water boiling test. Parameter yang diukur meliputi temperatur api pembakaran, temperatur air, konsumsi bahan bakar, dan waktu pendidihan.               Hasil penelitian menunjukkan bahwa variasi diameter burner berpengaruh terhadap karakteristik pembakaran yang dihasilkan. Temperatur pembakaran yang tinggi dicapai oleh burner dengan diameter 12,8mm dan 10mm, konsumsi bahan bakar yang kecil burner diameter 12,8mm dan waktu pendidihan yang pendek dicapai burner 12,8mm. Jadi kompor methanol dengan unjuk kerja terbaik adalah kompor methanol dengan diameter burner 12,8mm.

  15. Catalytic growth of carbon nanotubes with large inner diameters

    Directory of Open Access Journals (Sweden)

    WEI REN ZHONG

    2005-02-01

    Full Text Available Carbon nanotubes (2.4 g/g catalyst, with large inner diameters were successfully synthesized through pyrolysis of methane on a Ni–Cu–Al catalyst by adding sodium carbonate into the carbon nanotubes growth system. The inner diameter of the carbon nanotubes prepared by this method is about 20–60 nm, while their outer diameter is about 40–80 nm. Transmission electron microscopy and X-ray diffraction were employed to investigate the morphology and microstructures of the carbon nanotubes. The analyses showed that these carbon nanotubes have large inner diameters and good graphitization. The addition of sodium carbonate into the reaction system brings about a slight decrease in the methane conversion and the yield of carbon. The experimental results showed that sodium carbonate is a mildly toxic material which influenced the catalytic activity of the Ni–Cu–Al catalyst and resulted in the formation of carbon nanotubes with large inner diameters. The growth mechanism of the carbon nanotubes with large inner diameters is discussed in this paper.

  16. Failure Diameter of PBX 9502: Simulations with the SURFplus model

    Energy Technology Data Exchange (ETDEWEB)

    Menikoff, Ralph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-07-03

    SURFplus is a reactive burn model for high explosives aimed at modelling shock initiation and propagation of detonation waves. It utilizes the SURF model for the fast hot-spot reaction plus a slow reaction for the energy released by carbon clustering. A feature of the SURF model is that there is a partially decoupling between burn rate parameters and detonation wave properties. Previously, parameters for PBX 9502 that control shock ini- tiation had been calibrated to Pop plot data (distance-of-run to detonation as a function of shock pressure initiating the detonation). Here burn rate parameters for the high pres- sure regime are adjusted to t the failure diameter and the limiting detonation speed just above the failure diameter. Simulated results are shown for an uncon ned rate stick when the 9502 diameter is slightly above and slightly below the failure diameter. Just above the failure diameter, in the rest frame of the detonation wave, the front is sonic at the PBX/air interface. As a consequence, the lead shock in the neighborhood of the interface is supported by the detonation pressure in the interior of the explosive rather than the reaction immediately behind the front. In the interior, the sonic point occurs near the end of the fast hot-spot reaction. Consequently, the slow carbon clustering reaction can not a ect the failure diameter. Below the failure diameter, the radial extent of the detonation front decreases starting from the PBX/air interface. That is, the failure starts at the PBX boundary and propagates inward to the axis of the rate stick.

  17. Effects of Diameter on Initial Stiffness of P-Y Curves for Large-Diameter Piles in Sand

    DEFF Research Database (Denmark)

    Sørensen, Søren Peder Hyldal; Ibsen, Lars Bo; Augustesen, Anders Hust

    2010-01-01

    For offshore wind turbines, monopile foundations with diameters of 4–6m are often employed. The Winkler model approach, where the soil resistance is modelled as uncoupled springs with spring stiffness’ given by p-y curves, is traditionally employed for the design of monopiles. However, this method...... is developed for slender piles with diameters up to approximately 2.0 m. Hence, the method is not validated for piles with diameters of 4–6 m. The aim of the paper is to extend the p-y curve method to large-diameter non-slender piles in sand by considering the effects of the pile diameter on the soil......-pile interaction. Hence, a modified expression for the p-y curves for statically loaded piles in sand is proposed in which the initial slope of the p-y curves depends on the depth below the soil surface, the pile diameter and the internal angle of friction. The evaluation is based on three-dimensional numerical...

  18. Eyeball muscles' diameters versus volume estimated by numerical image segmentation.

    Science.gov (United States)

    Majos, A; Grzelak, P; Młynarczyk, W; Stefańczyk, L

    2007-01-01

    To determine the clinical usefulness of the numerical segmentation image technique (NSI) in estimating the volume of extraocular muscles and to compare this value to widely used measurements of single diameters of the muscles. Forty-five patients underwent magnetic resonance examinations in 1.5-T scanner. SE T1 sequences in transversal and coronal planes were provided and data were sent to a personal computer, where the degree of exophthalmos, horizontal diameter of medial rectus muscles, and vertical diameter of inferior rectus muscles were determined on the basis of two-dimensional images. The quantity estimation of all eye muscles volumes using NSI application in three-dimensional space was carried out with use of level set segmentation algorithm. A strong correlation between the total eye muscle volume and degree of exophthalmos was determined. The usefulness of measuring single diameters for estimating the muscles' enlargement was confirmed. The difference between a single muscle's volume and its width also was confirmed. Estimates of muscle volume correlate with the degree of exophthalmos more accurately than measurements of single diameters. The NSI technique is a clinically useful application, providing objective data calculated individually for each orbit. It allows an objective estimation of the pathologic processes leading to exophthalmos and may be especially helpful in monitoring discrete changes in the muscles volume during treatment.

  19. Diameter Effect Curve and Detonation Front Curvature Measurements for ANFO

    Science.gov (United States)

    Catanach, R. A.; Hill, L. G.

    2002-07-01

    Diameter effect and front curvature measurements are reported for rate stick experiments on commercially available prilled ANFO (ammonium-nitrate/fuel-oil) at ambient temperature. The shots were fired in paper tubes so as to provide minimal confinement. Diameters ranged from 77 mm (approximately failure diameter) to 205 mm, with the tube length being ten diameters in all cases. Each detonation wave shape was fit with an analytic form, from which the local normal velocity Dn, and local total curvature kappa, were generated as a function of radius R, then plotted parametrically to generate a Dn(kappa) function. The observed behavior deviates substantially from that of previous explosives, for which curves for different diameters overlay well for small kappa but diverge for large kappa, and for which kappa increases monotonically with R. For ANFO, we find that Dn(kappa) curves for individual sticks 1) show little or no overlap--with smaller sticks lying to the right of larger ones, 2) exhibit a large velocity deficit with little kappa variation, and 3) reach a peak kappa at an intermediate R.

  20. Compositional Variation in Large-Diameter Low-Albedo asteroids

    Science.gov (United States)

    Vilas, F.; Jarvis, K. S.; Thibault, C. A.; Sawyer, S. R.

    2000-12-01

    Age dating of meteorites indicates that the Solar System was subjected to a major heating event 4.5 Gyr ago. Models of the effects of heating by electromagnetic induction or decay of short-lived radionuclides combined with models of the early collisional history of the Solar System after Jupiter's formation indicate that asteroids observed today can be divided into two groups by diameter. Those asteroids having diameters greater than 100 km were mixed by multiple collisions but remain as gravitationally bound rubble piles. Asteroids with diameters less than 100 km should show more compositional diversity. Vilas and Sykes (1996, Icarus, 124) have shown using ECAS photometry that this compositional difference exists. The larger diameter group should be individually homogenous, with spectral differences showing the combined effects of a primordial compositional gradient in the asteroid belt with thermal metamorphism. We address the significance of 36 rotationally-resolved spectra of larger-diameter low-albedo asteroids of the C class (and subclasses B, F, G) and P class in the visible and Near-IR spectral regions. This work was supported by the NASA Planetary Astronomy program.

  1. Hole diameters in pet bottles used for fruit fly capture

    Directory of Open Access Journals (Sweden)

    Maurico Paulo Batistella Pasini

    2015-05-01

    Full Text Available Two experiments were conducted during the period from 31 January to 6 March 2012 in Santa Maria, Rio Grande do Sul State, Brazil to determine the efficiency of different hole diameters in PET trap bottles on pests in guava and persimmon orchards. In a randomised block design in a factorial scheme, we assessed the average number adults of Anastrepha fraterculus, Ceratitis capitata (Diptera: Tephitidae and Zaprionus indianus (Diptera: Drosophilidae infruits thatemerged in two situations (in the plant and on the soil; we also assessed the number of captured adults in trap bottlesunder two conditions, different hole diameters and different days after placement of the attractive solution. Smaller diameter sizescaptured more A. fraterculus, C. capitata and Z. indianusadults. The 1.0 cm diameter was the most efficient hole size in reducing the adult emergence of Tephritidae to Z. indianus, whereas the smallest diameter hole sizes, 0.6 and 0.8 cm, showed the highest efficiencies in controlling adult emergence in persimmon fruit and guava fruit.

  2. Nanofiber diameter as a critical parameter affecting skin cell response.

    Science.gov (United States)

    Pelipenko, Jan; Kocbek, Petra; Kristl, Julijana

    2015-01-23

    Electrospun polymer nanofibers have opened new opportunities in the rapidly evolving field of tissue engineering, particularly due to their topography and variability of available biomaterials. In order to better understand nanofiber influence on cell growth, the impact of their diameter was systematically examined. In this study homogenous, randomly oriented poly(vinyl alcohol) nanofibers with five different average diameters, ranging from 70nm to 1120nm, were produced, characterized and their impact on morphology, proliferation and mobility of keratinocytes and skin fibroblasts was evaluated. The results have shown that nanofiber diameter affects cell response and that this response is cell line specific. Nanofiber thickness affected size, morphology and actine organization of keratinocytes much more than fibroblasts. Specifically, the keratinocyte grown on nanofibers were more spherical and smaller compared to the control cells, while the fibroblasts were much less affect. They stayed almost unchanged and spread across growth surface. The cell proliferation determined based on their metabolic activity was the highest, when keratinocytes were grown on 305nm thick nanofibers, whereas proliferation of fibroblasts grown similar nanofibers was decreased. Finally, fibroblasts exerted higher mobility than keratinocytes. Both tested cell lines on nanofiber diameters of 300nm resulted in decreased cell mobility. These findings suggest that the control over nanofiber diameter offers promising possibility to better design the tissue scaffolds, since cells distinguish between differently sized nanofibers and respond accordingly. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Parametric Probability Distribution Functions for Axon Diameters of Corpus Callosum.

    Science.gov (United States)

    Sepehrband, Farshid; Alexander, Daniel C; Clark, Kristi A; Kurniawan, Nyoman D; Yang, Zhengyi; Reutens, David C

    2016-01-01

    Axon diameter is an important neuroanatomical characteristic of the nervous system that alters in the course of neurological disorders such as multiple sclerosis. Axon diameters vary, even within a fiber bundle, and are not normally distributed. An accurate distribution function is therefore beneficial, either to describe axon diameters that are obtained from a direct measurement technique (e.g., microscopy), or to infer them indirectly (e.g., using diffusion-weighted MRI). The gamma distribution is a common choice for this purpose (particularly for the inferential approach) because it resembles the distribution profile of measured axon diameters which has been consistently shown to be non-negative and right-skewed. In this study we compared a wide range of parametric probability distribution functions against empirical data obtained from electron microscopy images. We observed that the gamma distribution fails to accurately describe the main characteristics of the axon diameter distribution, such as location and scale of the mode and the profile of distribution tails. We also found that the generalized extreme value distribution consistently fitted the measured distribution better than other distribution functions. This suggests that there may be distinct subpopulations of axons in the corpus callosum, each with their own distribution profiles. In addition, we observed that several other distributions outperformed the gamma distribution, yet had the same number of unknown parameters; these were the inverse Gaussian, log normal, log logistic and Birnbaum-Saunders distributions.

  4. Parametric Probability Distribution Functions for Axon Diameters of Corpus Callosum

    Science.gov (United States)

    Sepehrband, Farshid; Alexander, Daniel C.; Clark, Kristi A.; Kurniawan, Nyoman D.; Yang, Zhengyi; Reutens, David C.

    2016-01-01

    Axon diameter is an important neuroanatomical characteristic of the nervous system that alters in the course of neurological disorders such as multiple sclerosis. Axon diameters vary, even within a fiber bundle, and are not normally distributed. An accurate distribution function is therefore beneficial, either to describe axon diameters that are obtained from a direct measurement technique (e.g., microscopy), or to infer them indirectly (e.g., using diffusion-weighted MRI). The gamma distribution is a common choice for this purpose (particularly for the inferential approach) because it resembles the distribution profile of measured axon diameters which has been consistently shown to be non-negative and right-skewed. In this study we compared a wide range of parametric probability distribution functions against empirical data obtained from electron microscopy images. We observed that the gamma distribution fails to accurately describe the main characteristics of the axon diameter distribution, such as location and scale of the mode and the profile of distribution tails. We also found that the generalized extreme value distribution consistently fitted the measured distribution better than other distribution functions. This suggests that there may be distinct subpopulations of axons in the corpus callosum, each with their own distribution profiles. In addition, we observed that several other distributions outperformed the gamma distribution, yet had the same number of unknown parameters; these were the inverse Gaussian, log normal, log logistic and Birnbaum-Saunders distributions. PMID:27303273

  5. NEOWISE REACTIVATION MISSION YEAR TWO: ASTEROID DIAMETERS AND ALBEDOS

    Energy Technology Data Exchange (ETDEWEB)

    Nugent, C. R.; Cutri, R. M. [Infrared Processing and Analysis Center, California Institute of Technology, Pasadena, CA 91125 (United States); Mainzer, A.; Bauer, J.; Kramer, E. A.; Masiero, J.; Sonnett, S. [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States); Grav, T. [Planetary Science Institute, Tucson, AZ (United States); Wright, E. L., E-mail: cnugent@ipac.caltech.edu [Department of Physics and Astronomy, University of California, Los Angeles, CA 90095 (United States)

    2016-09-01

    The Near-Earth Object Wide-Field Infrared Survey Explorer (NEOWISE) mission continues to detect, track, and characterize minor planets. We present diameters and albedos calculated from observations taken during the second year since the spacecraft was reactivated in late 2013. These include 207 near-Earth asteroids (NEAs) and 8885 other asteroids. Of the NEAs, 84% NEAs did not have previously measured diameters and albedos by the NEOWISE mission. Comparison of sizes and albedos calculated from NEOWISE measurements with those measured by occultations, spacecraft, and radar-derived shapes shows accuracy consistent with previous NEOWISE publications. Diameters and albedos fall within ±∼20% and ±∼40%, 1-sigma, respectively, of those measured by these alternate techniques. NEOWISE continues to preferentially discover near-Earth objects which are large (>100 m), and have low albedos.

  6. Application of direct tracking method for measuring electrospun nanofiber diameter

    Directory of Open Access Journals (Sweden)

    M. Ziabari

    2009-03-01

    Full Text Available In this paper, direct tracking method as an image analysis based technique for measuring electrospun nanofiber diameter has been presented and compared with distance transform method. Samples with known characteristics generated using a simulation scheme known as µ-randomness were employed to evaluate the accuracy of the method. Electrospun webs of polyvinyl alcohol (PVA were also used to verify the applicability of the method on real samples. Since direct tracking as well as distance transform require binary input images, micrographs of the electrospun webs obtained from Scanning Electron Microscopy (SEM were first converted to black and white using local thresholding. Direct tracking resulted in more accurate estimations of fiber diameter for simulated images as well as electrospun webs suggesting the usefulness of the method for electrospun nanofiber diameter measurement.

  7. Characteristics of two-phase flows in large diameter channels

    Energy Technology Data Exchange (ETDEWEB)

    Schlegel, J.P., E-mail: schlegelj@mst.edu [Department of Mining and Nuclear Engineering, Missouri University of Science and Technology, 301 W 14th St., Rolla, MO 65401 (United States); Hibiki, T.; Ishii, M. [School of Nuclear Engineering, Purdue University, 400 Central Dr., West Lafayette, IN 47907 (United States)

    2016-12-15

    Two-phase flows in large diameter channels have a great deal of importance in a wide variety of industrial applications. Nuclear systems, petroleum refineries, and chemical processes make extensive use of larger systems. Flows in such channels have very different properties from flows in smaller channels which are typically used in experimental research. In this paper, the various differences between flows in large and small channels are highlighted using the results of previous experimental and analytical research. This review is followed by a review of recent experiments in and model development for flows in large diameter channels performed by the authors. The topics of these research efforts range from void fraction and interfacial area concentration measurement to flow regime identification and modeling, drift-flux modeling for high void fraction conditions, and evaluation of interfacial area transport models for large diameter channels.

  8. Reduced arterial diameter during static exercise in humans

    DEFF Research Database (Denmark)

    Olesen, H L; Mitchell, J H; Friedman, D B

    1995-01-01

    exertion was approximately 15 units after both types of exercise. The dorsalis pedis arterial diameter was 1.50 +/- 0.20 mm (mean and SE) and the radial AD 2.45 +/- 0.12 mm. During both types of contractions the luminal diameters decreased approximately 3.5% within the first 30 s (P ...In eight subjects luminal diameter of the resting limb radial and dorsalis pedis arteries was determined by high-resolution ultrasound (20 MHz). This measurement was followed during rest and during 2 min of static handgrip or of one-leg knee extension at 30% of maximal voluntary contraction...... of another limb. Static exercise increased heart rate and mean arterial pressure, which were largest during one-leg knee extension. After exercise heart rate and mean arterial pressure returned to the resting level. No changes were recorded in arterial carbon dioxide tension, and the rate of perceived...

  9. NEOWISE REACTIVATION MISSION YEAR ONE: PRELIMINARY ASTEROID DIAMETERS AND ALBEDOS

    Energy Technology Data Exchange (ETDEWEB)

    Nugent, C. R.; Cutri, R. M. [Infrared Processing and Analysis Center, California Institute of Technology, Pasadena, CA 91125 (United States); Mainzer, A.; Masiero, J.; Bauer, J.; Kramer, E.; Sonnett, S.; Stevenson, R. [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States); Grav, T. [Planetary Science Institute, Tucson, AZ (United States); Wright, E. L., E-mail: cnugent@ipac.caltech.edu [Department of Physics and Astronomy, University of California, Los Angeles, CA 90095 (United States)

    2015-12-01

    We present preliminary diameters and albedos for 7956 asteroids detected in the first year of the NEOWISE Reactivation mission. Of those, 201 are near-Earth asteroids and 7755 are Main Belt or Mars-crossing asteroids. 17% of these objects have not been previously characterized using the Near-Earth Object Wide-field Infrared Survey Explorer, or “NEOWISE” thermal measurements. Diameters are determined to an accuracy of ∼20% or better. If good-quality H magnitudes are available, albedos can be determined to within ∼40% or better.

  10. The heliometric Astrolabe, a new instrument for solar diameter observations

    Science.gov (United States)

    Andrei, A. H.; Reis Neto, E.; D'Ávila, V. A.; Penna, J. L.; Assafin, M.; Boscardin, S. C.; De Avila, K. N.

    2006-10-01

    The Observatorio Nacional takes part in the Reseau de Suivi au Sol du Rayon Solaire (the international solar diameter monitoring network) which co-participates in the PICARD micro satellite, to be launched in 2008 to study the Earth climate and Sun variability relationship. A new instrument, a heliometer, was devised in order to minimize the atmospheric turbulence and reach data accuracy compatible with PICARD's. The heliometer principle of double images will be added to the astrolabe metrological quality, and fully digitized acquisition. The objective is to obtain two simultaneous images from the Sun, with fixed angular separation of about 30', which variation will contain the signature of the diameter variation.

  11. Improved Design Basis for Laterally Loaded Large Diameter Pile

    DEFF Research Database (Denmark)

    Leth, Caspar Thrane

    . Comparison of the different approaches shows some discrepancy and conflicting statements, but the main findings can be summarized as: • The standard p-y curves are inadequate to describe the behaviour of lateral loaded large diameter rigid piles. • Initial stiffness of the p-y curves is depended...... of up-to-date facilities has been: Equipment for controlling centrifuge tests, data acquisition, preparation of test samples and equipment for and making of lateral load tests. The present research has been narrowed to investigate the static and cyclic behaviour of stiff piles with a diameter of 1-3 m...

  12. NEOWISE Reactivation Mission Year Three: Asteroid Diameters and Albedos

    Energy Technology Data Exchange (ETDEWEB)

    Masiero, Joseph R.; Mainzer, A. K.; Kramer, E. [Jet Propulsion Laboratory/California Institute of Technology, 4800 Oak Grove Drive, MS 183-301, Pasadena, CA 91109 (United States); Nugent, C.; Cutri, R. M. [California Institute of Technology, Infrared Processing and Analysis Center, 1200 California Boulevard, Pasadena, CA 91125 (United States); Wright, E. L. [University of California, Los Angeles, CA 90095 (United States); Bauer, J. M. [University of Maryland, College Park, MD 20742 (United States); Grav, T.; Sonnett, S., E-mail: Joseph.Masiero@jpl.nasa.gov [Planetary Science Institute, 1700 E Fort Lowell Road #106, Tucson, AZ 85719 (United States)

    2017-10-01

    The Near-Earth Object Wide-field Infrared Survey Explorer (NEOWISE) reactivation mission has completed its third year of surveying the sky in the thermal infrared for near-Earth asteroids and comets. NEOWISE collects simultaneous observations at 3.4 and 4.6  μ m of solar system objects passing through its field of regard. These data allow for the determination of total thermal emission from bodies in the inner solar system, and thus the sizes of these objects. In this paper, we present thermal model fits of asteroid diameters for 170 NEOs and 6110 Main Belt asteroids (MBAs) detected during the third year of the survey, as well as the associated optical geometric albedos. We compare our results with previous thermal model results from NEOWISE for overlapping sample sets, as well as diameters determined through other independent methods, and find that our diameter measurements for NEOs agree to within 26% (1 σ ) of previously measured values. Diameters for the MBAs are within 17% (1 σ ). This brings the total number of unique near-Earth objects characterized by the NEOWISE survey to 541, surpassing the number observed during the fully cryogenic mission in 2010.

  13. NEOWISE Reactivation Mission Year Three: Asteroid Diameters and Albedos

    Science.gov (United States)

    Masiero, Joseph R.; Nugent, Carrie; Mainzer, Amy K.; Wright, Edward L.; Bauer, James M.; Cutri, Roc M.; Grav, Tommy; Kramer, Emily A.; Sonnett, Sarah M.

    2017-10-01

    The Near-Earth Object Wide-field Infrared Survey Explorer (NEOWISE) reactivation mission has completed its third year of surveying the sky in the thermal infrared for near-Earth asteroids and comets. NEOWISE collects simultaneous observations at 3.4 um and 4.6 um of Solar System objects passing through its field of regard. These data allow for the determination of total thermal emission from bodies in the inner Solar System, and thus the sizes of these objects. We present thermal model fits of asteroid diameters for 170 NEOs and 6110 MBAs detected during the third year of the survey, as well as the associated optical geometric albedos. We also compare our results with previous thermal model results from NEOWISE for overlapping sample sets, as well as diameters determined through other independent methods, and find that our diameter measurements for NEOs agree to within 26% (1-sigma) of previously measured values. Diameters for the MBAs are within 17% (1-sigma). This brings the total number of unique near-Earth objects characterized by the NEOWISE survey to 541, surpassing the number observed during the fully cryogenic mission in 2010.

  14. Uncertainty budget for optical coordinate measurements of circle diameter

    DEFF Research Database (Denmark)

    Morace, Renate Erica; Hansen, Hans Nørgaard; De Chiffre, Leonardo

    2004-01-01

    An uncertainty analysis for circle diameter measurements using a coordinate measuring machine (CMM) equipped with an optical probe is presented in this paper. A mathematical model for data evaluation and uncertainty assessment was formulated in accordance with Guide to the Expression of Uncertainty...

  15. Stem diameter and height of chrysanthemum cv Yoko ono as ...

    African Journals Online (AJOL)

    Administrator

    2011-09-26

    Sep 26, 2011 ... was aimed to evaluate the development of height and diameter of the stems of chrysanthemum cultivar. Yoko ono by the applications of ... cultivar Faroe (Vieira, 2008) and Anthurium andreanum. (Wang, 1999), GA3 was not .... Diagnóstico de cadeia produtiva de flores e de plantas ornamentais do Brasil.

  16. A small-diameter NMR logging tool for groundwater investigations

    Science.gov (United States)

    Walsh, David; Turner, Peter; Grunewald, Elliot; Zhang, Hong; Butler, James J.; Reboulet, Ed; Knobbe, Steve; Christy, Tom; Lane, John W.; Johnson, Carole D.; Munday, Tim; Fitzpatrick, Andrew

    2013-01-01

    A small-diameter nuclear magnetic resonance (NMR) logging tool has been developed and field tested at various sites in the United States and Australia. A novel design approach has produced relatively inexpensive, small-diameter probes that can be run in open or PVC-cased boreholes as small as 2 inches in diameter. The complete system, including surface electronics and various downhole probes, has been successfully tested in small-diameter monitoring wells in a range of hydrogeological settings. A variant of the probe that can be deployed by a direct-push machine has also been developed and tested in the field. The new NMR logging tool provides reliable, direct, and high-resolution information that is of importance for groundwater studies. Specifically, the technology provides direct measurement of total water content (total porosity in the saturated zone or moisture content in the unsaturated zone), and estimates of relative pore-size distribution (bound vs. mobile water content) and hydraulic conductivity. The NMR measurements show good agreement with ancillary data from lithologic logs, geophysical logs, and hydrogeologic measurements, and provide valuable information for groundwater investigations.

  17. Growth process and diameter structure of Pinus tabulaeformis forest ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-10-19

    Oct 19, 2009 ... hectare were measured using trunk analysis. Each index value was the mean value of three trees in this study. The fitting equation of the growing processes of tree height, tree diameter at breast height, single timber volume and stumpage accumulation were made using quadratic equations. Then, the rules ...

  18. The holin of bacteriophage lambda forms rings with large diameter

    National Research Council Canada - National Science Library

    Savva, Christos G; Dewey, Jill S; Deaton, John; White, Rebecca L; Struck, Douglas K; Holzenburg, Andreas; Young, Ry

    2008-01-01

    ...‐ionic or mild zwitterionic detergents, purified S105, but not the lysis‐defective variant S105 A52V , forms rings of at least two size classes, the most common having inner and outer diameters of 8.5 and 23...

  19. Small-diameter trees used for chemithermomechanical pulps.

    Science.gov (United States)

    Gary C. Myers; R. James Barbour; Said M. AbuBakr

    2003-01-01

    To restore and maintain forest ecosystem health and function in the western interior of the United States, many small-diameter stems need to be removed from densely stocked stands. In general, these materials are underutilized. Information on the properties of these resources is needed to help forest managers understand when timber sales are a viable option to...

  20. Effect of Collar Diameter and Lifting Period on Shoot Biomass ...

    African Journals Online (AJOL)

    The effects of collar diameter and lifting period on shoot biomass production of Teak (Tectona grandis Linn. F) stumps were investigated during the 2006 dry season on the research farm of Kwame Nkrumah University of Science and Technology, Kumasi, Ghana. The lifting period is time when planting of stumps is delayed.

  1. Bipartite Diametrical Graphs of Diameter 4 and Extreme Orders

    Directory of Open Access Journals (Sweden)

    Salah Al-Addasi

    2008-01-01

    in which this upper bound is attained, this graph can be viewed as a generalization of the Rhombic Dodecahedron. Then we show that for any ≥2, the graph (2,2 is the unique (up to isomorphism bipartite diametrical graph of diameter 4 and partite sets of cardinalities 2 and 2, and hence in particular, for =3, the graph (6,8 which is just the Rhombic Dodecahedron is the unique (up to isomorphism bipartite diametrical graph of such a diameter and cardinalities of partite sets. Thus we complete a characterization of -graphs of diameter 4 and cardinality of the smaller partite set not exceeding 6. We prove that the neighborhoods of vertices of the larger partite set of (2,2 form a matroid whose basis graph is the hypercube . We prove that any -graph of diameter 4 is bipartite self complementary, thus in particular (2,2. Finally, we study some additional properties of (2,2 concerning the order of its automorphism group, girth, domination number, and when being Eulerian.

  2. Aortic Diameter Growth in Children With a Bicuspid Aortic Valve

    NARCIS (Netherlands)

    Merkx, R.; Duijnhouwer, A.L.; Vink, E. de; Roos-Hesselink, J.W.; Schokking, M.

    2017-01-01

    Knowledge of aortic growth in patients with bicuspid aortic valve (BAV) is essential to identify patients at risk for dissection, but data on children remain unclear. We retrospectively evaluated the aortic diameters of all pediatric BAV patients, identified through an echocardiographic database

  3. Aortic Diameter Growth in Children With a Bicuspid Aortic Valve

    NARCIS (Netherlands)

    Merkx, R. (Remy); A.L. Duijnhouwer (Anthonie L.); Vink, E. (Evelien); J.W. Roos-Hesselink (Jolien); M. Schokking (Michiel)

    2017-01-01

    textabstractKnowledge of aortic growth in patients with bicuspid aortic valve (BAV) is essential to identify patients at risk for dissection, but data on children remain unclear. We retrospectively evaluated the aortic diameters of all pediatric BAV patients, identified through an echocardiographic

  4. Historical perspective on diameter-limit cutting in northeastern forests

    Science.gov (United States)

    Matthew J. Kelty; Anthony W. D' Amato; Anthony W. D' Amato

    2006-01-01

    The use of diameter-limit cutting and high-grading is currently a concern for long-term sustainability of forests in the Northeastern United States and surrounding areas. This paper reviews historical information about the kinds of harvesting used in this region from 1620 to 1950, to provide a context for current discussions. Throughout this period, most timber...

  5. Determination of perimysial and fascicular diameters of triceps ...

    African Journals Online (AJOL)

    In this study, it was observed that all the muscles studied presented normal histomorphology of a typical skeletal muscle, it was discovered that the biceps brachii muscle from camel aged 7 years had higher and significant value for the perimysial diameter compared to that of cattle. Similarly, it was shown that there is an ...

  6. FACES WITH LARGE DIAMETER ON THE SYMMETRICAL TRAVELING SALESMAN POLYTOPE

    NARCIS (Netherlands)

    SIERKSMA, G; TIJSSEN, GA

    This paper deals with the symmetric traveling salesman polytope and contains three main theorems. The first one gives a new characterization of (non)adjacency. Based on this characterization a new upper bound for the diameter of the symmetric traveling salesman polytope (conjectured to be 2 by M.

  7. Percentile-based Weibull diameter distribution model for Pinus ...

    African Journals Online (AJOL)

    This study was conducted to develop a diameter distribution model for Pinus kesiya stands in Benguet province, Philippines, using the percentile-based Weibull model. The performance of the different equations was examined using evaluation statistics such as the fit index (FI) and root mean square error (RMSE). Results ...

  8. predictive accuracy of transcerebellar diameter in comparison with ...

    African Journals Online (AJOL)

    2014-04-04

    Apr 4, 2014 ... the characteristic “butterfly” appearance of the cerebellum into view, as proposed by Meyer et al. (15) TCD was then measured as the widest diameter ..... Estimating foetal age: the effect of head shape on. BPD. AJR 1981; 137: 83 – 85. 8. Mahoney MJ, Hobbins JC. Prenatal diagnosis of chondroectodermal ...

  9. A small-diameter NMR logging tool for groundwater investigations.

    Science.gov (United States)

    Walsh, David; Turner, Peter; Grunewald, Elliot; Zhang, Hong; Butler, James J; Reboulet, Ed; Knobbe, Steve; Christy, Tom; Lane, John W; Johnson, Carole D; Munday, Tim; Fitzpatrick, Andrew

    2013-01-01

    A small-diameter nuclear magnetic resonance (NMR) logging tool has been developed and field tested at various sites in the United States and Australia. A novel design approach has produced relatively inexpensive, small-diameter probes that can be run in open or PVC-cased boreholes as small as 2 inches in diameter. The complete system, including surface electronics and various downhole probes, has been successfully tested in small-diameter monitoring wells in a range of hydrogeological settings. A variant of the probe that can be deployed by a direct-push machine has also been developed and tested in the field. The new NMR logging tool provides reliable, direct, and high-resolution information that is of importance for groundwater studies. Specifically, the technology provides direct measurement of total water content (total porosity in the saturated zone or moisture content in the unsaturated zone), and estimates of relative pore-size distribution (bound vs. mobile water content) and hydraulic conductivity. The NMR measurements show good agreement with ancillary data from lithologic logs, geophysical logs, and hydrogeologic measurements, and provide valuable information for groundwater investigations. © 2013, National Ground Water Association.

  10. Compositional Variegation of Large-Diameter Low-Albedo Asteroids

    Science.gov (United States)

    Vilas, F.; Jarvis, K. S.; Anz-Meador, T. D.; Thibault, C. A.; Sawyer, S. R.; Fitzsimmons, A.

    1997-07-01

    Asteroids showing signs of aqueous alteration and thermal metamorphism in visible/near IR spectroscopy and photometry (C, G, F, B, and P classes) ranging from 0.37 - 0.90mu m dominate the asteroid population at heliocentric distances of 2.6 - 3.5 AU. Age dating of meteorites indicates that the Solar System was subjected to a major heating event 4.5 Gyr ago. Recent meteoritic research has produced evidence of a carbonaceous chondrite subjected to two separate aqueous alteration events with a metamorphic heating inbetween (Krot et al., 1997, submitted). Models of the effects of heating by electromagnetic induction or decay of short-lived radionuclides combined with models of the early collisional history of the Solar System after Jupiter's formation indicate that asteroids observed today can be divided into two groups by diameter. Those asteroids having diameters greater than 100 km were mixed by multiple collisions but remain as gravitationally bound rubble piles. Asteroids with diameters less than 100 km should show more compositional diversity. Vilas and Sykes (1996, Icarus, v. 124, 483) have shown using ECAS photometry that this compositional difference exists. Those asteroids having diameters greater than 100 km should be individually homogeneous, with spectral differences showing the combined effects of a primordial compositional gradient in the asteroid belt with thermal metamorphism. We address the significance of spatially-resolved spectra of 42 asteroids to the collective origin of these asteroids.

  11. Changes in intraocular pressure and horizontal pupil diameter ...

    African Journals Online (AJOL)

    The objective of this study was to determine the effects of topical 0.5% tropicamide, 1% atropine sulphate and 10% phenylephrine hydrochloride ophthalmic solutions on intraocular pressure (IOP) and horizontal pupil diameter (HPD) in the dog during the first hour after treatment. Forty clinically and ophthalmologically ...

  12. Relationships between diameter and height of trees in natural ...

    African Journals Online (AJOL)

    The relationship between tree height (h) and tree diameter at breast height (dbh) is an important element describing forest stands. In addition, h often is a required variable in volume and biomass models. Measurements of h are, however, more time consuming compared to those of dbh, and visual obstructions, rounded ...

  13. Novel Genetic Loci Associated with Retinal Microvascular Diameter

    NARCIS (Netherlands)

    R.A. Jensen (Richard); X. Sim (Xueling); G.D. Smith; X. Li (Xiaohui); M. Jakobsdottir (Margret); C-Y. Cheng (Ching-Yu); J. Brody (Jennifer); M.F. Cotch (Mary Frances); B. McKnight (Barbara); R. Klein (Ronald); J.J. Wang (Jie Jin); A. Kifley (Annette); T.B. Harris (Tamara); L.J. Launer (Lenore); K.D. Taylor (Kent D.); B.E.K. Klein (Barbara); L.J. Raffel (Leslie); X. Li (Xiang); M.A. Ikram (Arfan); C.C.W. Klaver (Caroline); S.J. van der Lee (Sven); U. Mutlu (Unal); A. Hofman (Albert); A.G. Uitterlinden (André); C. Liu (Chunyu); A. Kraja (Aldi); P. Mitchell (Paul); V. Gudnason (Vilmundur); J.I. Rotter (Jerome I.); E.A. Boerwinkle (Eric); C.M. van Duijn (Cornelia); B.M. Psaty (Bruce); T.Y. Wong (Tien Yin)

    2016-01-01

    textabstractBackground-There is increasing evidence that retinal microvascular diameters are associated with cardiovascular and cerebrovascular conditions. The shared genetic effects of these associations are currently unknown. The aim of this study was to increase our understanding of the genetic

  14. Generalized height-diameter models for Populus tremula L. stands

    African Journals Online (AJOL)

    USER

    2010-07-12

    Jul 12, 2010 ... recommended for estimating tree heights for P. tremula L. in Turkey. The model coefficients are documented for future use. Key words: Schnute's function, h-d models, Populus tremula L. INTRODUCTION. Individual tree heights and diameters are essential measurement in forest inventories and are used for.

  15. Modelling diameter growth, mortality and recruitment of trees in ...

    African Journals Online (AJOL)

    Individual tree diameter growth and mortality models, and area-based recruitment models were developed. The modelling was based on data from 117 permanent sample plots established between 1997 and 2009 on seven sites in the Iringa and Manyara regions. The data set comprised 2 314 trees at establishment and 4 ...

  16. Definition of Beam Diameter for Electron Beam Welding

    Energy Technology Data Exchange (ETDEWEB)

    Burgardt, Paul [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Pierce, Stanley W. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Dvornak, Matthew John [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-03-11

    It is useful to characterize the dimensions of the electron beam during process development for electron beam welding applications. Analysis of the behavior of electron beam welds is simplest when a single number can be assigned to the beam properties that describes the size of the beam spot; this value we generically call the “beam diameter”. This approach has worked well for most applications and electron beam welding machines with the weld dimensions (width and depth) correlating well with the beam diameter. However, in recent weld development for a refractory alloy, Ta-10W, welded with a low voltage electron beam machine (LVEB), it was found that the weld dimensions (weld penetration and weld width) did not correlate well with the beam diameter and especially with the experimentally determined sharp focus point. These data suggest that the presently used definition of beam diameter may not be optimal for all applications. The possible reasons for this discrepancy and a suggested possible alternative diameter definition is the subject of this paper.

  17. Height-Diameter Predictive Equations for Rubber ( Hevea ...

    African Journals Online (AJOL)

    Many of the resulting models and curves agreed with silvicultural expectation of sigmoidal growth functions; and can provide dependable cum flexible options of predicting heights, given dbh for many plantation species in Nigeria. Keywords: height-diameter equations, allometric models, predictive equations, sigmoidal ...

  18. Height-diameter allometry of tropical forest trees

    NARCIS (Netherlands)

    Feldpausch, T.R.; Banin, L.; Phillips, O.L.; Baker, T.R.; Lewis, S.L.; Quesada, C.A.; Affum-Baffoe, K.; Arets, E.J.M.M.; Berry, N.J.; Bird, M.; Brondizio, E.S.; Camargo, de P.; Chave, J.; Djagbletey, G.; Domingues, T.F.; Drescher, M.; Fearnside, P.M.; Franca, M.B.; Fyllas, N.M.; Lopez-Gonzalez, G.; Hladik, A.; Higuchi, N.; Hunter, M.O.; Iida, Y.; Salim, K.A.; Kassim, A.R.; Keller, M.; Kemp, J.; King, D.A.; Lovett, J.C.; Marimon, B.S.; Marimon-Junior, B.H.; Lenza, E.; Marshall, A.R.; Metcalfe, D.J.; Mitchard, E.T.A.; Moran, E.F.; Nelson, B.W.; Nilus, R.; Nogueira, E.M.; Palace, M.; Patino, S.; Peh, K.S.H.; Raventos, M.T.; Reitsma, J.M.; Saiz, G.; Schrodt, F.; Sonké, B.; Taedoumg, H.E.; Tan, S.; White, L.; Wöll, H.; Lloyd, J.

    2010-01-01

    Tropical tree height-diameter (H:D) relationships may vary by forest type and region making large-scale estimates of above-ground biomass subject to bias if they ignore these differences in stem allometry. We have therefore developed a new global tropical forest database consisting of 39 955

  19. Height-diameter allometry of tropical forest trees

    Science.gov (United States)

    T.R. Feldpausch; L. Banin; O.L. Phillips; T.R. Baker; S.L. Lewis; C.A. Quesada; K. Affum-Baffoe; E.J.M.M. Arets; N.J. Berry; M. Bird; E.S. Brondizio; P de Camargo; J. Chave; G. Djagbletey; T.F. Domingues; M. Drescher; P.M. Fearnside; M.B. Franca; N.M. Fyllas; G. Lopez-Gonzalez; A. Hladik; N. Higuchi; M.O. Hunter; Y. Iida; K.A. Salim; A.R. Kassim; M. Keller; J. Kemp; D.A. King; J.C. Lovett; B.S. Marimon; B.H. Marimon-Junior; E. Lenza; A.R. Marshall; D.J. Metcalfe; E.T.A. Mitchard; E.F. Moran; B.W. Nelson; R. Nilus; E.M. Nogueira; M. Palace; S. Patiño; K.S.-H. Peh; M.T. Raventos; J.M. Reitsma; G. Saiz; F. Schrodt; B. Sonke; H.E. Taedoumg; S. Tan; L. White; H. Woll; J. Lloyd

    2011-01-01

    Tropical tree height-diameter (H:D) relationships may vary by forest type and region making large-scale estimates of above-ground biomass subject to bias if they ignore these differences in stem allometry. We have therefore developed a new global tropical forest database consisting of 39 955 concurrent H and D measurements encompassing 283 sites in 22 tropical...

  20. Individual tree diameter, height, and volume functions for longleaf pine

    Science.gov (United States)

    Carlos A. Gonzalez-Benecke; Salvador A. Gezan; Timothy A. Martin; Wendell P. Cropper; Lisa J. Samuelson; Daniel J. Leduc

    2014-01-01

    Currently, little information is available to estimate individual tree attributes for longleaf pine (Pinus palustris Mill.), an important tree species of the southeastern United States. The majority of available models are local, relying on stem diameter outside bark at breast height (dbh, cm) and not including stand-level parameters. We developed...

  1. Real-time precision measuring device of tree diameter growth

    Science.gov (United States)

    Guo, Mingming; Chen, Aijun; Li, Dongsheng; Liu, Nan; Yao, Jingyuan

    2016-01-01

    DBH(diameter at breast height) is an important factor to reflect of the quality of plant growth, also an important parameter indispensable in forest resources inventory and forest carbon sink, the accurate measurement of DBH or not is directly related to the research of forest resources inventory and forest carbon sink. In this paper, the principle and the mathematical model of DBH measurement device were introduced, the fixture measuring device and the hardware circuit for this tree diameter were designed, the measurement software programs were compiled, and the precision measuring device of tree diameter growth was developed. Some experiments with Australia fir were conducted. Based on experiment data, the correlations among the DBH variation of Australian fir, the environment temperature, air humility and PAR(photosynthetically active radiation) were obtained. The effects of environmental parameters (environment temperature, air humility and PAR) on tree diameter were analyzed. Experimental results show that there is a positive correlation between DBH variation of Australian fir and environment temperature, a negative correlation between DBH variation of Australian fir and air humility , so is PAR.

  2. Sex determination from femoral head diameters in black Malawians ...

    African Journals Online (AJOL)

    Objectives: To determine the sex of black Malawians from femoral head diameters. Design: A retrospective study on patients investigated in three x-ray departments. Setting: Radiographs were collected from the archives of Queen Elizabeth Central, Chikwawa and Balaka hospitals. Subject: X-ray films of 496 pelves of adult ...

  3. Diameter Distributions in Natural Yellow-Poplar Stands

    Science.gov (United States)

    Charles E. McGee; Lino Della-Bianca

    1967-01-01

    Diameter distributions obtained from 141 pure, natural unthinned yellow-poplar stands in the Appalachian Mountains of Virginia, North Carolina, and Georgia are presented in tables. The distributions are described in relation to stand age, site index, and total number of trees per acre, and are useful for stand management planning.

  4. Diameter sensors for tree-length harvesting systems

    Science.gov (United States)

    T.P. McDonald; Robert B. Rummer; T.E. Grift

    2003-01-01

    Most cut-to-length (CTL) harvesters provide sensors for measuring diameter of trees as they are cut and processed. Among other uses, this capability provides a data collection tool for marketing of logs in real time. Logs can be sorted and stacked based on up-to-date market information, then transportation systems optimized to route wood to proper destinations at...

  5. Measurement error in CT assessment of appendix diameter

    Energy Technology Data Exchange (ETDEWEB)

    Trout, Andrew T.; Towbin, Alexander J. [Cincinnati Children' s Hospital Medical Center, Department of Radiology, MLC 5031, Cincinnati, OH (United States); Zhang, Bin [Cincinnati Children' s Hospital Medical Center, Department of Biostatistics and Epidemiology, Cincinnati, OH (United States)

    2016-12-15

    Appendiceal diameter continues to be cited as an important criterion for diagnosis of appendicitis by computed tomography (CT). To assess sources of error and variability in appendiceal diameter measurements by CT. In this institutional review board-approved review of imaging and medical records, we reviewed CTs performed in children <18 years of age between Jan. 1 and Dec. 31, 2010. Appendiceal diameter was measured in the axial and coronal planes by two reviewers (R1, R2). One year later, 10% of cases were remeasured. For patients who had multiple CTs, serial measurements were made to assess within patient variability. Measurement differences between planes, within and between reviewers, within patients and between CT and pathological measurements were assessed using correlation coefficients and paired t-tests. Six hundred thirty-one CTs performed in 519 patients (mean age: 10.9 ± 4.9 years, 50.8% female) were reviewed. Axial and coronal measurements were strongly correlated (r = 0.92-0.94, P < 0.0001) with coronal plane measurements significantly larger (P < 0.0001). Measurements were strongly correlated between reviewers (r = 0.89-0.9, P < 0.0001) but differed significantly in both planes (axial: +0.2 mm, P=0.003; coronal: +0.1 mm, P=0.007). Repeat measurements were significantly different for one reviewer only in the axial plane (0.3 mm difference, P<0.05). Within patients imaged multiple times, measured appendix diameters differed significantly in the axial plane for both reviewers (R1: 0.5 mm, P = 0.031; R2: 0.7 mm, P = 0.022). Multiple potential sources of measurement error raise concern about the use of rigid diameter cutoffs for the diagnosis of acute appendicitis by CT. (orig.)

  6. Vertebral Artery Diameter and Flow: Nature or Nurture.

    Science.gov (United States)

    Tarnoki, Adam Domonkos; Fejer, Bence; Tarnoki, David Laszlo; Littvay, Levente; Lucatelli, Pierleone; Cirelli, Carlo; Fanelli, Fabrizio; Sacconi, Beatrice; Fagnani, Corrado; Medda, Emanuela; Farina, Filippo; Meneghetti, Giorgio; Horvath, Tamas; Pucci, Giacomo; Schillaci, Giuseppe; Stazi, Maria Antonietta; Baracchini, Claudio

    2017-09-01

    In contrast with the carotid arteries, the vertebral arteries (VAs) show considerable variation in length, caliber, and vessel course. This study investigated whether the variation in diameter and flow characteristics of the VAs might be inherited. A total of 172 Italian twins from Padua, Perugia, and Terni (54 monozygotic, 32 dizygotic) recruited from the Italian Twin Registry underwent B-mode and pulsed-wave Doppler ultrasound assessment of their VAs. VA diameters, peak systolic velocity (PSV) and end diastolic velocity (EDV) were assessed at the level of a horizontal V2 segment. Univariate quantitative genetic modeling was performed. Fourteen percent of the sample had VA hypoplasia. Within pair correlation in monozygotic twins was higher than in dizygotics (.552 vs. .229) for VA diameter. Age- and sex-adjusted genetic effect, under the most parsimonious model, accounted for 54.7% (95% CI: 42.2-69.1%) of the variance of VA diameter, and unshared environmental effect for 45.3% (95% CI: 30.9-57.8%). No heritability was found for the PSV of VA, but shared (34.1%; 95% CI: 16.7-53.7%) and unshared (65.9%; 95% CI: 45.9-83.1%) environmental factors determined the variance. EDV of VA is moderately genetically influenced (42.4%; 95% CI: 16.1-64.9%) and also determined by the unshared environment (57.6%; 95% CI: 34.7-83.7%). The diameter of the VAs is moderately genetically determined. Different factors influence the PSV and EDV of VAs, which may highlight the complex hemodynamic background of VA flow and help to understand the vertebral flow anomalies found by ultrasound. Copyright © 2017 by the American Society of Neuroimaging.

  7. Computational identification of genes modulating stem height-diameter allometry.

    Science.gov (United States)

    Jiang, Libo; Ye, Meixia; Zhu, Sheng; Zhai, Yi; Xu, Meng; Huang, Minren; Wu, Rongling

    2016-12-01

    The developmental variation in stem height with respect to stem diameter is related to a broad range of ecological and evolutionary phenomena in trees, but the underlying genetic basis of this variation remains elusive. We implement a dynamic statistical model, functional mapping, to formulate a general procedure for the computational identification of quantitative trait loci (QTLs) that control stem height-diameter allometry during development. Functional mapping integrates the biological principles underlying trait formation and development into the association analysis of DNA genotype and endpoint phenotype, thus providing an incentive for understanding the mechanistic interplay between genes and development. Built on the basic tenet of functional mapping, we explore two core ecological scenarios of how stem height and stem diameter covary in response to environmental stimuli: (i) trees pioneer sunlit space by allocating more growth to stem height than diameter and (ii) trees maintain their competitive advantage through an inverse pattern. The model is equipped to characterize 'pioneering' QTLs (piQTLs) and 'maintaining' QTLs (miQTLs) which modulate these two ecological scenarios, respectively. In a practical application to a mapping population of full-sib hybrids derived from two Populus species, the model has well proven its versatility by identifying several piQTLs that promote height growth at a cost of diameter growth and several miQTLs that benefit radial growth at a cost of height growth. Judicious application of functional mapping may lead to improved strategies for studying the genetic control of the formation mechanisms underlying trade-offs among quantities of assimilates allocated to different growth parts. © 2016 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

  8. [EXPERIMENTAL RESEARCH OF CORE FAT TRANSFER WITH DIFFERENT DIAMETERS].

    Science.gov (United States)

    Qin, Wangchi; Liang, Zhi; Yang, Weiguo; Lin, Haibo

    2016-02-01

    To investigate the survival rate of core fat tissue with different diameters by advanced fat harvesting instrument. Based on core fat transfer by 1 mL syringe, the fat harvesting instrument was modified with different diameters, including 4, 6, 8, and 10 mm respectively. Between May 2014 and April 2015, the fat harvesting instrument with diameters of 4, 6, 8, and 10 mm was respectively used to harvest abdominal fat in 3 of 12 patients undergoing autologous fat transplantation. The glucose transportation quantities and the fat cell viability were measured. Then 64 nude mice at the age of 3-4 weeks were randomly divided into 4 groups (groups A, B, C, and D, n=16). And 0.5 mL fat harvested with diameters of 4, 6, 8, and 10 mm was implanted into the dorsal subcutaneous space. After fat transplantation, the mice survival and the appearance at the recipient site were observed. At 1, 2, 4, and 8 weeks after fat transplantation, the grafted fat was harvested for gross, histological and immunohistochemical observations; the intact adipocytes and capillary were counted. The glucose transportation quantities gradually increased with increased diameter, showing significant difference among groups (Pappearance became flat at the recipient site, but the appearance of groups C and D was better than groups A and B. Normal shape of the fat and capillary were found in groups C and D. At immediate and 1 week after fat transplantation, there was no significant difference in fat weight among 4 groups (P>0.05); the fat weight of group A was significantly less than that of groups B, C, and D (P0.05). Histological and immunohistochemical observations showed better integrity of the cells, less necrosis, and higher vascular density in group D than groups A, B, and C as time extension. The adipocyte integrity of group A was significantly worse than that of other 3 groups at other time points (P0.05). At each time point, the capillary counting had an increasing trend with increased diameter

  9. Reference diameter in calculations of creep strain for steam pipelines

    Directory of Open Access Journals (Sweden)

    Łopata Stanisław

    2017-01-01

    Full Text Available Recommended methods of the operational safety assessment of high-pressure steam pipelines include periodic testing that enables determination of creep strain and the creep rate. The accuracy with which the two quantities are determined depends, among others, on the control of the testing conditions and on the assumed reference diameter. The analysis conducted herein concerns the impact of the reference diameter on the results characterizing the creep phenomenon in the pipeline elements (straight sections and bends. In this respect, the initial ovality of the pipeline cross-section is an important parameter. The calculations are made using own results obtained from many years of the steam pipeline creep testing, including tests performed after the expiry of the computational service life.

  10. Soap bubbles: two years old and sixty centimeters in diameter.

    Science.gov (United States)

    Grosse, A V

    1969-04-18

    Soap bubbles of long life (over 2 years) and large size (over 60 centimeters in diameter, 100 liters volume) have been produced from bubble solutions improved by the addition of water-soluble synthetic organic polymers such as polyvinyl alcohol or polyoxyethylene. The natural life can be defined as the time it takes for the bubble, if left undisturbed, to contract from the original size to a flat film.

  11. Visual function and retinal vessel diameters during hyperthermia in man.

    Science.gov (United States)

    Jensen, Bettina Hagström; Bram, Thue; Kappelgaard, Per; Arvidsson, Henrik; Loskutova, Ekaterina; Munch, Inger Christine; Larsen, Michael

    2017-11-01

    To assess the effect of elevated core body temperature on temporal and spatial contrast sensitivity and retinal vessel diameters. The study included 13 healthy volunteers aged 20-37 years. Core body temperature elevation (target +1.1°C) was induced by wrapping the participants in cling film, tinfoil and warming blankets. Subsequent cooling was achieved by undressing. Flicker sensitivity (critical flicker fusion frequency) was chosen to assess temporal resolution, while the Freiburg Vision Test was used to determine spatial contrast sensitivity at 1.5 cycles per degree. Scanning laser ophthalmoscopy was used to measure retinal trunk vessel diameters. Assessment was made at baseline, during hyperthermia and after cooling. The induction of a mean increase in core body temperature of 1.02°C was associated with a 7.15-mmHg mean reduction in systolic blood pressure (p < 0.01), a 10.6-mmHg mean reduction in diastolic blood pressure (p < 0.01), a mean increase in pulse rate of 36.3 bpm (p < 0.0001), a 2.66% improvement in flicker sensitivity (CI95 1.37-3.94, p < 0.001), a 2.80% increase in retinal artery diameters (CI95 1.09-4.51, p < 0.01) and a 2.95% increase in retinal vein diameters (CI95 0.96-4.94, p < 0.01). There was no detectable effect of temperature on spatial contrast sensitivity. All ocular test parameters returned to baseline levels after cooling. Increased core body temperature was accompanied by improved temporal visual resolution and retinal trunk vessel dilation. The results suggest that hyperthermia is associated with enhanced retinal function and increased retinal metabolism. © 2016 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

  12. A study of the heated length to diameter effects

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Yong Ho; Baek, Won Pil; Chang, Soon Heung [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of)

    1997-12-31

    An analytical and experimental investigation has been performed on the heated length-to-diameter effect on critical heat flux exit conditions. A L/D correction factor is developed by applying artificial neural network and conventional regression techniques to the KAIST CHF data base. In addition, experiment is being performed to validate the developed L/D correction factor with independent data. Assessment shows that the developed correction factor is promising for practical applications. 6 refs., 8 figs. (Author)

  13. APPROXIMATION ALGORITHMS FOR CLUSTERING TO MINIMIZE THE SUM OF DIAMETERS

    Energy Technology Data Exchange (ETDEWEB)

    Kopp, S.; Mortveit, H.S.; Reidys, S.M.

    2000-02-01

    We consider the problem of partitioning the nodes of a complete edge weighted graph into {kappa} clusters so as to minimize the sum of the diameters of the clusters. Since the problem is NP-complete, our focus is on the development of good approximation algorithms. When edge weights satisfy the triangle inequality, we present the first approximation algorithm for the problem. The approximation algorithm yields a solution that has no more than 10k clusters such the total diameter of these clusters is within a factor O(log (n/{kappa})) of the optimal value fork clusters, where n is the number of nodes in the complete graph. For any fixed {kappa}, we present an approximation algorithm that produces {kappa} clusters whose total diameter is at most twice the optimal value. When the distances are not required to satisfy the triangle inequality, we show that, unless P = NP, for any {rho} {ge} 1, there is no polynomial time approximation algorithm that can provide a performance guarantee of {rho} even when the number of clusters is fixed at 3. Other results obtained include a polynomial time algorithm for the problem when the underlying graph is a tree with edge weights.

  14. Optical coating uniformity of 200mm (8") diameter precut wafers

    Science.gov (United States)

    Burt, Travis C.; Fisher, Mark; Brown, Dean; Troiani, David

    2017-02-01

    Automated spectroscopic profiling (mapping) of a 200 mm diameter near infrared high reflector (centered at 1064 nm) are presented. Spatial resolution at 5 mm or less was achieved using a 5 mm × 1.5 mm monochromatic beam. Reflection changes of 1.0% across the wafer diameter were observed under s-polarized and p- polarized conditions. Redundancy was established for each chord by re-measuring the center of the wafer and reproducibility of approximately used to measure the reflectance and transmittance of a sample across a range of angles (θi) at near normal angles of incidence (AOI). A recent development by Agilent Technologies, the Cary 7000 Universal Measurement Spectrophotometer (UMS) combines both reflection and transmission measurements from the same patch of a sample's surface in a single automated platform for angles of incidence in the range 5°use of MPS on the Cary 7000 UMS with rotational (Φ) and vertical (z) sample positioning control. MPS(θi,Φ,z) provides for automated unattended multi-angle R/T analysis of at 200 mm diameter samples with the goal to provide better spectroscopic measurement feedback into large wafer manufacturing to ensure yields are maximized, product quality is better controlled and waste is reduced before further down-stream processing.

  15. J-integral of circumferential crack in large diameter pipes

    Science.gov (United States)

    Ji, Wei; Chao, Yuh J.; Sutton, M. A.; Lam, P. S.; Mertz, G. E.

    Large diameter thin-walled pipes are encountered in a low pressure nuclear power piping system. Fracture parameters such as K and J, associated with postulated cracks, are needed to assess the safety of the structure, for example, prediction of the onset of tile crack growth and the stability of the crack. The Electric Power Research Institute (EPRI) has completed a comprehensive study of cracks in pipes and handbook-type data is available. However, for some large diameter, thin-walled pipes the needed information is not included in the handbook. This paper reports our study of circumferential cracks in large diameter, thin-walled pipes (R/t=30 to 40) under remote bending or tension loads. Elastic-Plastic analyses using the finite element method were performed to determine the elastic and fully plastic J values for various pipe/crack geometries. A non-linear Ramberg-Osgood material model is used with strain hardening exponents (n) that range from 3 to 10. A number of circumferential, through thickness cracks were studied with half crack angles ranging from 0.063(pi) to 0.5(pi). Results are tabulated for use with the EPRI estimation scheme.

  16. Tree height-diameter allometry across the United States.

    Science.gov (United States)

    Hulshof, Catherine M; Swenson, Nathan G; Weiser, Michael D

    2015-03-01

    The relationship between tree height and diameter is fundamental in determining community and ecosystem structure as well as estimates of biomass and carbon storage. Yet our understanding of how tree allometry relates to climate and whole organismal function is limited. We used the Forest Inventory and Analysis National Program database to determine height-diameter allometries of 2,976,937 individuals of 293 tree species across the United States. The shape of the allometric relationship was determined by comparing linear and nonlinear functional forms. Mixed-effects models were used to test for allometric differences due to climate and floristic (between angiosperms and gymnosperms) and functional groups (leaf habit and shade tolerance). Tree allometry significantly differed across the United States largely because of climate. Temperature, and to some extent precipitation, in part explained tree allometric variation. The magnitude of allometric variation due to climate, however, had a phylogenetic signal. Specifically, angiosperm allometry was more sensitive to differences in temperature compared to gymnosperms. Most notably, angiosperm height was more negatively influenced by increasing temperature variability, whereas gymnosperm height was negatively influenced by decreasing precipitation and increasing altitude. There was little evidence to suggest that shade tolerance influenced tree allometry except for very shade-intolerant trees which were taller for any given diameter. Tree allometry is plastic rather than fixed and scaling parameters vary around predicted central tendencies. This allometric variation provides insight into life-history strategies, phylogenetic history, and environmental limitations at biogeographical scales.

  17. Tree height–diameter allometry across the United States

    Science.gov (United States)

    Hulshof, Catherine M; Swenson, Nathan G; Weiser, Michael D

    2015-01-01

    The relationship between tree height and diameter is fundamental in determining community and ecosystem structure as well as estimates of biomass and carbon storage. Yet our understanding of how tree allometry relates to climate and whole organismal function is limited. We used the Forest Inventory and Analysis National Program database to determine height–diameter allometries of 2,976,937 individuals of 293 tree species across the United States. The shape of the allometric relationship was determined by comparing linear and nonlinear functional forms. Mixed-effects models were used to test for allometric differences due to climate and floristic (between angiosperms and gymnosperms) and functional groups (leaf habit and shade tolerance). Tree allometry significantly differed across the United States largely because of climate. Temperature, and to some extent precipitation, in part explained tree allometric variation. The magnitude of allometric variation due to climate, however, had a phylogenetic signal. Specifically, angiosperm allometry was more sensitive to differences in temperature compared to gymnosperms. Most notably, angiosperm height was more negatively influenced by increasing temperature variability, whereas gymnosperm height was negatively influenced by decreasing precipitation and increasing altitude. There was little evidence to suggest that shade tolerance influenced tree allometry except for very shade-intolerant trees which were taller for any given diameter. Tree allometry is plastic rather than fixed and scaling parameters vary around predicted central tendencies. This allometric variation provides insight into life-history strategies, phylogenetic history, and environmental limitations at biogeographical scales. PMID:25859325

  18. Real-time diameter measurement using diffuse light

    Science.gov (United States)

    Luo, Xiaohe; Hui, Mei; Zhu, Qiudong; Wang, Shanshan

    2016-09-01

    A method for on-line rapid determination of the diameter of metallic cylinder is introduced in this paper. Under the radiation of diffuse light, there is a bright area close to the margin of metallic cylinder, and the method of this paper is based on the intensity distribution of the bright area. In this paper, with the radiation by a diffuse plane light with special shape, we present the relation expression of the distance between the peak point and the real edge of the cylinder and the distance between the diffuse light and the pinhole aperture of the camera. With the expression, the diameter of the cylinder to be measured can be calculated. In the experiments, monochromatic LED uniting with ground glass forms the diffuse light source, then the light irradiates the tested cylinder. After the cylinder, we use a lens with a front pinhole stop to choose the light into CMOS, then a computer is used to analyze images and export the measurement results. The measuring system using this method is very easily implemented, so it can realize the on-line rapid measurement. Experimental results are presented for six metallic cylinders with the diameter in 5 18mm range and roughness in Ra- 0.02um, and the precision reaches 3um.

  19. Clinical outcome of narrow diameter implants inserted into allografts

    Directory of Open Access Journals (Sweden)

    Maurizio Franco

    2009-08-01

    Full Text Available OBJECTIVE: Narrow diameter implants (NDI (i.e. diameter <3.75 mm are a potential solution for specific clinical situations, such as reduced interradicular bone, thin alveolar crest and replacement of teeth with small cervical diameter. NDI have been available in clinical practice since the 1990s, but only few studies have analyzed their clinical outcome and no study have investigated NDI inserted in fresh-frozen bone (FFB grafts. Thus, a retrospective study on a series of NDI placed in homologue FFB was designed to evaluate their clinical outcome. MATERIAL AND METHODS: In the period between December 2003 and December 2006, 36 patients (22 females and 14 males, mean age 53 years with FFB grafts were selected and 94 different NDI were inserted. The mean follow-up was 25 months. To evaluate the effect of several host-, surgery-, and implant-related factors, marginal bone loss (MBL was considered an indicator of success rate (SCR. The Kaplan Meier algorithm and Cox regression were used. RESULTS: Only 5 out of 94 implants were lost (i.e. survival rate - SVR 95.7% and no differences were detected among the studied variables. On the contrary, the Cox regression showed that the graft site (i.e. maxilla reduced MBL. CONCLUSIONS: NDI inserted in FFB have a high SVR and SCR similar to those reported in previous studies on regular and NDI inserted in non-grafted jaws. Homologue FFB is a valuable material in the insertion of NDI.

  20. Clinical research of micro-incision phacoemulsification for short axis cataract

    Directory of Open Access Journals (Sweden)

    Xing-Xing Zhao

    2015-07-01

    Full Text Available AIM:To observe the clinical effect of 2.2mm micro-incision phacoemulsification(Phacocombined intraocular lens(IOLimplantation in the eyes with short axial length and compared with traditional 3.0mm incision phacoemulsification operation for clinical work and research objective information. METHODS:In this prospective clinical control study, 60 cases(60 eyeswith cataract performed 2.2mm micro-incision phacoemulsification combined IOL implantation(micro-incision group, implanted Akreos MI60 IOL and 3.0mm incision phacoemulsification operation(small incision group, implanted Akreos Adapt IOL, whose axial length ranged 17.68~21.32mm, average 20.35±0.61mm. Average axiall ength respectively of two groups: 20.57±0.39mm and 20.21±0.52mm. Effect Phaco time(EPTand average ultrasonic energy(AVEwere recorded. The best corrected visual acuity(BCVA, intraocular pressure(IOP, anterior chamber depth(ACD, corneal endothelial cell density and the operative complications were observed postoperatively. All cases were followed up at 1, 7, 30 and 90d after operation. RESULTS:EPT and AVE between two groups had no statistical significance(P>0.05. At the 1, 7 and 30d after surgery, induced astigmatism(SIAof micro-incision group was lower than that of small-incision group. SIA between two groups had statistically significant(PP>0.05. At the 7d, the BCVA between two groups had statistical significance(PP>0.05. At the 7, 30 and 90d, corneal endothelial cell density of micro-incision group was higher than that of small incision group. Corneal endothelial cell density between two groups had no statistical significance. The mean ACD was significant increased postoperatively than preoperatively and had no statistical significance(P>0.05. The anterior chamber stabilized during the operation. There was not incision hot harmed during operation and postoperation. CONCLUSION:Compared with 2.2mm micro-incision and traditional 3.0mm incision phacoemulsification, two groups have the same safety and 2.2mm micro-incision phacoemulsification has small SIA, organization small harm and improved visual acuity in early stage.

  1. Impact of pupil diameter on axial growth in orthokeratology.

    Science.gov (United States)

    Chen, Zhi; Niu, Lingling; Xue, Feng; Qu, Xiaomei; Zhou, Zimei; Zhou, Xingtao; Chu, Renyuan

    2012-11-01

    To compare axial elongation between myopic orthokeratology (OK) contact lens and spectacle wearers, and to investigate the impact of pupil diameter on axial growth in myopic children after OK treatment. Fifty-two Chinese children aged 9 to 14 years were enrolled in this study, 27 for the OK group and 25 for the single vision spectacle lenses (SVL) group. Subjects in each group were further divided into two subcategories according to their baseline scotopic pupil diameters. Axial length (AL) was measured at baseline and at every 6-month visit through to 24 months. Linear mixed-effect model was used to determine myopia progression (AL changes from baseline). In this model, repeated visits were taken as within-subject effect, and treatment group as well as pupil size were taken as between-subject effects. The interaction of treatment group*pupil size was analyzed. Relationships between axial growth at 24 months and baseline pupil area were analyzed in both lens groups. Twenty-five subjects in the OK group and 22 subjects in the SVL group completed the 24-month study. AL increased significantly throughout the observed 24-month period (F = 32.09, p Pupil size significantly affected axial growth (F = 15.95, p pupil size on axial growth (F = 24.66, p pupil sizes than those with below average pupil sizes in the OK group (F = 25.04, p pupil size did not affect axial growth in the SVL group (F = 0.46, p = 0.50). Baseline scotopic pupil area was significantly correlated to axial growth in the OK group (r = 0.405, p pupil diameters facilitate the effect of OK to slow axial growth in myopia. We speculate that this is because of enhancement of the myopic shift in the peripheral retina.

  2. Aortic Diameter Growth in Children With a Bicuspid Aortic Valve.

    Science.gov (United States)

    Merkx, Remy; Duijnhouwer, Anthonie L; Vink, Evelien; Roos-Hesselink, Jolien W; Schokking, Michiel

    2017-07-01

    Knowledge of aortic growth in patients with bicuspid aortic valve (BAV) is essential to identify patients at risk for dissection, but data on children remain unclear. We retrospectively evaluated the aortic diameters of all pediatric BAV patients, identified through an echocardiographic database (2005 to 2013). Medical records were reviewed and aortic diameters re-measured on echocardiographic images at diagnosis and if available on variable mid- and endpoints follow-up. Dilatation (z-score >2) was based on 2 different z-score equation methods (Gautier/Campens). In 234 of the total 250 BAV patients, aortic diameters were analyzed; median age was 6.1 years (interquartile range 1.7 to 10), of which 63% were male. Aortic coarctation was present in 81 (36%) patients, 23% had a ventricular septal defect. BAV morphology according to Sievers was as follows: type 0 in 128 patients (55%), type 1 in 96 (41%), and type 2 in 10 (4%). Ascending aortic (AA) dilatation was present in 24% (Gautier) and 36% (Campens) at inclusion. Median follow-up was 4.7 years. The AA was the only location where mean z-scores progressed significantly with age: 0.06 (Gautier) and 0.09 (Campens) units per year between ages 5 and 15 years. Associations for higher AA z-scores at older age were an initial z-score >2 (p aortic valve stenosis (p aortic surgery occurred. In conclusion, only the AA seems at risk for complication, although no aortic complications occurred in this pediatric BAV cohort. BAV morphology seems associated with larger AA z-scores and valvular dysfunction. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

  3. A solar cycle lengthwise series of solar diameter measurements

    Science.gov (United States)

    Penna, J. L.; Andrei, A. H.; Boscardin, S. C.; Neto, E. Reis; d'Ávila, V. A.

    2010-02-01

    The measurements of the solar photospheric diameter rank among the most difficult astronomic observations. Reasons for this are the fuzzy definition of the limb, the SNR excess, and the adverse daytime seeing condition. As a consequence there are very few lengthy and consistent time series of such measurements. Using modern techniques, just the series from the IAG/USP and from Calern/OCA span more than one solar cycle. The Rio de Janeiro Group observations started in 1997, and therefore in 2008 one complete solar cycle time span can be analyzed. The series shares common principles of observation and analysis with the ones afore mentioned, and it is complementary on time to them. The distinctive features are the larger number of individual points and the improved precision. The series contains about 25,000 single observations, evenly distributed on a day-by-day basis. The typical error of a single observation is half an arc-second, enabling us to investigate variations at the expected level of tens of arc-second on a weekly basis. These features prompted to develop a new methodology for the investigation of the heliophysical scenarios leading to the observed variations, both on time and on heliolatitude. The algorithms rely on running averages and time shifts to derive the correlation and statistical incertitude for the comparison of the long term and major episodes variations of the solar diameter against activity markers. The results bring support to the correlation between the diameter variation and the solar activity, but evidentiating two different regimens for the long term trend and the major solar events.

  4. Effect of the diameter on Cu-Al post retention

    OpenAIRE

    Celso Bernardo de Souza Filho; Silvana Maria Paulino; Edson Alfredo; Manoel Damião de Sousa Neto; Luiz Pascoal Vansan

    2004-01-01

    This study compared the resistance to removal by traction of abraded cylindrical metal cast posts of Cu-Al (Goldent-LA). The posts had constant length (9 mm) and three different diameters (0.9, 1.3 and 1.7 mm), and were cemented with zinc phosphate cement. The crowns of 36 sound maxillary canines were sectioned, the roots were immersed in resin blocks and the root canals were endodontically treated. The teeth were divided into three groups to be prepared and standardized with the use of a par...

  5. Vascular diameter determining the magnification for a microvascular anastomosis.

    Science.gov (United States)

    Andrades, Patricio; Benítez, Susana; Danilla, Stefan; Erazo, Cristian; Hasbun, Andrea; Fix, Jobe

    2008-04-01

    The purpose of this study was to determine the association between vascular diameters and amount of magnification and to assess the influence of the magnification media on the microanastomosis quality and permeability. Sixty arterial microanostomoses were distributed into three groups: group I (diameter 1.5 mm), group II (1.5 to 2.5 mm), and group III (> 2.5 mm). The models used were carotid artery of Sprague-Dawley rats and carotid and abdominal artery of wild rabbits. In each group, 10 anastomoses were performed with 2.5 x loupes and 10 with 10 x microscope. The total time of anastomosis, the quality of the anastomosis (Gorman scale), and 24-hour permeability rate were measured. The total anastomotic time and quality had statistical differences for the microscope by analyzing the total sample and group I only. The global permeability was 83% for the microscope and 40% for the loupe. The same result was observed in group I but no differences were observed in the other groups. The histology and the survey showed similar results. Microanastomoses performed under a microscope (10 x) were performed in less time, were of better quality, and had higher permeability rates when compared with those performed under a loupe (2.5 x). In vessels 1.5 mm no differences were observed.

  6. [Small-diameter portosystemic shunts: indications and limitations].

    Science.gov (United States)

    Angel Mercado, M; Granados-García, J; Barradas, F; Chan, C; Contreras, J L; Orozco, H; Angel-Mercado, M

    1998-01-01

    Low diameter porto-systemic shunts for the treatment of portal hypertension bleeding have emerged as a consequence of the technical development of vascular grafts (PTFE) that allow the use of a narrow lumen. The experience with this kind of operation at the Instituto Nacional de la Nutrición Salvador Zubirán, Mexico City during a 6-year period is reported. There were twenty-seven patients with good liver function (Child-Pugh A-B) were operated or electively, average Age 47.5 years (range 17-71), twenty three patients with liver cirrhosis, one with portal fibrosis and three with idiopathic portal hypertension. Operative mortality: 4%. Rebleeding: 14%. Postoperative encephalopathy was observed in 14 of 27, three of them being grade III-IV (11%). In the remaining 11 cases, it was mild and easily controlled. Postoperative angiography showed shunt patency in 81% of the cases; in 33% of the cases, portal vein diameter reduction was shown, as well as two cases with portal vein thrombosis. In 77% of the cases, adequate postoperative quality of life was observed. Survival (Kaplan-Meier): 86% at 12 months and 56% at 60 months. These kinds of shunts are a good alternate choice for patients considered for surgery, in which other portal blood flow preserving procedures (selective shunts, devascularization with transection) are not feasible.

  7. Tunable engineered skin mechanics via coaxial electrospun fiber core diameter.

    Science.gov (United States)

    Blackstone, Britani Nicole; Drexler, Jason William; Powell, Heather Megan

    2014-10-01

    Autologous engineered skin (ES) offers promise as a treatment for massive full thickness burns. Unfortunately, ES is orders of magnitude weaker than normal human skin causing it to be difficult to apply surgically and subject to damage by mechanical shear in the early phases of engraftment. In addition, no manufacturing strategy has been developed to tune ES biomechanics to approximate the native biomechanics at different anatomic locations. To enhance and tune ES biomechanics, a coaxial (CoA) electrospun scaffold platform was developed from polycaprolactone (PCL, core) and gelatin (shell). The ability of the coaxial fiber core diameter to control both scaffold and tissue mechanics was investigated along with the ability of the gelatin shell to facilitate cell adhesion and skin development compared to pure gelatin, pure PCL, and a gelatin-PCL blended fiber scaffold. CoA ES exhibited increased cellular adhesion and metabolism versus PCL alone or gelatin-PCL blend and promoted the development of well stratified skin with a dense dermal layer and a differentiated epidermal layer. Biomechanics of the scaffold and ES scaled linearly with core diameter suggesting that this scaffold platform could be utilized to tailor ES mechanics for their intended grafting site and reduce graft damage in vitro and in vivo.

  8. Effect of nylon suture diameter on induced astigmatism after phacoemulsification.

    Science.gov (United States)

    Mendívil, A

    1997-10-01

    To prospectively compare the clinical results of 10-0 and 9-0 monofilament nylon sutures after phacoemulsification with poly(methyl methacrylate) intraocular lens implantation through a 4.0 mm cruciate incision. Department of Ophthalmology, Ramón y Cajal Hospital, Madrid, Spain. One hundred eyes with cataract were randomly assigned to have surgery using a 10-0 or a 9-0 nylon suture. Except for suture diameter, identical surgical methods were used in every case. Data on uncorrected visual acuity, keratometry and postoperative astigmatism were analyzed up to 12 months after surgery. Both groups had similar uncorrected visual acuity. Mean postoperative corneal astigmatism was against the rule in the 10-0 nylon suture group and with the rule in the 9-0 nylon suture group. Significant differences were found between groups (P suture diameters offered satisfactory clinical results. Patients with preoperative with-the-rule astigmatism might benefit from 10-0 nylon sutures and those with preoperative against-the-rule astigmatism, from 9-0 nylon sutures.

  9. Allowable pillar to diameter ratio for strategic petroleum reserve caverns.

    Energy Technology Data Exchange (ETDEWEB)

    Ehgartner, Brian L.; Park, Byoung Yoon

    2011-05-01

    This report compiles 3-D finite element analyses performed to evaluate the stability of Strategic Petroleum Reserve (SPR) caverns over multiple leach cycles. When oil is withdrawn from a cavern in salt using freshwater, the cavern enlarges. As a result, the pillar separating caverns in the SPR fields is reduced over time due to usage of the reserve. The enlarged cavern diameters and smaller pillars reduce underground stability. Advances in geomechanics modeling enable the allowable pillar to diameter ratio (P/D) to be defined. Prior to such modeling capabilities, the allowable P/D was established as 1.78 based on some very limited experience in other cavern fields. While appropriate for 1980, the ratio conservatively limits the allowable number of oil drawdowns and hence limits the overall utility and life of the SPR cavern field. Analyses from all four cavern fields are evaluated along with operating experience gained over the past 30 years to define a new P/D for the reserve. A new ratio of 1.0 is recommended. This ratio is applicable only to existing SPR caverns.

  10. Small-diameter laparoscopy (SDL) using a microlaparoscope.

    Science.gov (United States)

    Bauer, O; Küpker, W; Felberbaum, R; Gerling, W; Diedrich, K

    1996-04-01

    To determine the ability of new sub-2.0-mm-diameter microlaparoscopes to be used for diagnostic laparoscopy, 28 small-diameter laparoscopies (SDL) were performed during a 4-month-period. These cases were performed under general anesthesia, with immediate follow-up confirmation with conventional laparoscopic equipment. An additional 13 SDL procedures were performed under analgosedation plus local anesthesia and were well tolerated by the patients. For the cases performed with conventional laparoscopic control, the visualization results were comparable in 27 of 28 procedures. In the nongeneral anesthesia SDL group, patients were highly satisfied and reported less post-procedural discomfort and minimal scar formation due to the smaller access ports. In this study, two types of microlaparoscopes were used. While both were adequate, the newer high-resolution microlaparoscope delivered an image much more similar to that which conventional laparoscopy and required little or no change in technique in order to obtain images. With the advent of this new endoscope technology with optics performance comparable to that of conventional laparoscopes, SDL has demonstrated to be a useful procedure for certain clinical indications.

  11. Unobtrusively tracking mammographers' eye gaze direction and pupil diameter

    Science.gov (United States)

    Barrett, James R.; deParedes, Ellen S.; Dwyer, Samuel J., III; Merickel, Michael B.; Hutchinson, Thomas E.

    1994-04-01

    We developed techniques to unobtrusively track direction and pupil diameter of radiologists reading a wide variety of films. This study concentrated on mammography since the use of mammograms is important for successful treatment of breast cancer, and we wished to determine how previous studies of eye gaze with lung films relate to the specialized field of mammography. Our objective was to identify eye gaze patterns in mammographic experts as they observe features, such as masses and microcalcification clusters: identification of these patterns could lead to improving the rate of early detection of breast cancer. Our near IR light system successfully tracked eye gaze direction and pupil diameter of mammographic experts evaluating films. The association of long eye gaze dwells with diagnostic accuracy varied with the type of object being viewed. In films with masses, false positive diagnoses were associated with long dwells: this is similar to published results of observing lung nodule diagnosis. In mammograms with microcalcifications, true positive diagnoses were associated with long dwells. The association of prolonged dwells with true positive diagnoses of microcalcifications is a new observation.

  12. Muscle fiber diameter assessment in cleft lip using image processing.

    Science.gov (United States)

    Khan, M F J; Little, J; Abelli, L; Mossey, P A; Autelitano, L; Nag, T C; Rubini, M

    2017-10-04

    To pilot investigation of muscle fiber diameter (MFD) on medial and lateral sides of the cleft in 18 infants with cleft lip with or without cleft palate (CL/P) using image processing. Formalin-fixed paraffin-embedded (FFPE) tissue samples from the medial and lateral sides of the cleft were analyzed for MFD using an image-processing program (ImageJ). For within-case comparison, a paired Student's t test was performed. For comparisons between classes, an unpaired t test was used. Image processing enabled rapid measurement of MFD with majority of fibers showing diameter between 6 and 11 μm. There was no significant difference in mean MFD between the medial and lateral sides, or between CL and CLP. However, we found a significant difference on the medial side (p = .032) between males and females. The image processing on FFPE tissues resulted in easy quantification of MFD with finding of a smaller MFD on the medial side in males suggesting possible differences in orbicularis oris (OO) muscle between the two sexes in CL that warrants replication using larger number of cases. Moreover, this finding can aid subclinical phenotyping and potentially in the restoration of the anatomy and function of the upper lip. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd. All rights reserved.

  13. Threshold Particle Diameters in Miniemulsion Reversible-Deactivation Radical Polymerization

    Directory of Open Access Journals (Sweden)

    Hidetaka Tobita

    2011-11-01

    Full Text Available Various types of controlled/living radical polymerizations, or using the IUPAC recommended term, reversible-deactivation radical polymerization (RDRP, conducted inside nano-sized reaction loci are considered in a unified manner, based on the polymerization rate expression, Rp = kp[M]K[Interm]/[Trap]. Unique miniemulsion polymerization kinetics of RDRP are elucidated on the basis of the following two factors: (1 A high single molecule concentration in a nano-sized particle; and (2 a significant statistical concentration variation among particles. The characteristic particle diameters below which the polymerization rate start to deviate significantly (1 from the corresponding bulk polymerization, and (2 from the estimate using the average concentrations, can be estimated by using simple equations. For stable-radical-mediated polymerization (SRMP and atom-transfer radical polymerization (ATRP, an acceleration window is predicted for the particle diameter range, . For reversible-addition-fragmentation chain-transfer polymerization (RAFT, degenerative-transfer radical polymerization (DTRP and also for the conventional nonliving radical polymerization, a significant rate increase occurs for . On the other hand, for  the polymerization rate is suppressed because of a large statistical variation of monomer concentration among particles.

  14. MODELING AND DESIGN OF INNOVATIVE SMALL DIAMETER GRAVITY SEWERAGE SYSTEM

    Directory of Open Access Journals (Sweden)

    Tadeusz Nawrot

    2017-05-01

    Full Text Available The article presents modern methods of hydraulic design of an innovative small diameter gravity sewerage system. In this system, domestic wastewater is preliminary treated in septic tanks equipped with outlet filters, thus the effluent features are similar to those of clear water. Innovative non-return valves at the outlets eliminate introduction of air to the system and thus the flows can be treated as one-phase ones. Computer codes EPANET 2 and SWMM 5.0 were applied and compared. Two flow schemes typical for the sewerage system were implemented in EPANET 2, and the third - in a slightly modified SWMM 5.0. Simulation results were validated on empirical data obtained on a laboratory physical model, consisting of four tanks of minimum volumes 600 dm3 each, connecting PE pipelines of diameters 25 mm and 36 mm and relevant sanitary fittings. Water inflows, typical for domestic wastewater outflows from single homesteads, were provided by a pump. Water flows were measured using water meters with pulse outputs, and water levels in tanks by pressure transducers. Hydraulic characteristics of filters and non-return valves were provided. Simulation results showed good agreement with the empirical data. Ranges of values of design parameters, needed for successful application of both codes, were established and discussed.

  15. The Use of Narrow Diameter Implants in the Molar Area

    Directory of Open Access Journals (Sweden)

    M. Saad

    2016-01-01

    Full Text Available Implant rehabilitations in the posterior jaw are influenced by many factors such as the condition of the remaining teeth, the force factors related to the patient, the quality of the bone, the maintenance of the hygiene, the limited bone height, the type and extent of edentulism, and the nature of the opposing arch. The gold standard is to place a regular diameter implant (>3.7 mm or a wide one to replace every missing molar. Unfortunately, due to horizontal bone resorption, this option is not possible without lateral bone augmentation. In this situation, narrow diameter implant (NDI < 3.5 mm could be the alternative to lateral bone augmentation procedures. This paper presents a clinical study where NDIs were used for the replacement of missing molars. They were followed up to 11 years. Special considerations were observed and many parameters were evaluated. NDI could be used to replace missing molar in case of moderate horizontal bone resorption if strict guidelines are respected. Yet, future controlled prospective clinical trials are required to admit their use as scientific evidence.

  16. Diameter of titanium nanotubes influences anti-bacterial efficacy

    Energy Technology Data Exchange (ETDEWEB)

    Ercan, Batur; Taylor, Erik; Webster, Thomas J [School of Engineering, Brown University, Providence, RI 02917 (United States); Alpaslan, Ece, E-mail: thomas_webster@brown.edu [Faculty of Engineering and Natural Sciences, Sabanci University, Istanbul (Turkey)

    2011-07-22

    Bacterial infection of in-dwelling medical devices is a growing problem that cannot be treated by traditional antibiotics due to the increasing prevalence of antimicrobial resistance and biofilm formation. Here, due to changes in surface parameters, it is proposed that bacterial adhesion can be prevented through nanosurface modifications of the medical device alone. Toward this goal, titanium was created to possess nanotubular surface topographies of highly controlled diameters of 20, 40, 60, or 80 nm, sometimes followed by heat treatment to control chemistry and crystallinity, through a novel anodization process. For the first time it was found that through the control of Ti surface parameters including chemistry, crystallinity, nanotube size, and hydrophilicity, significantly changed responses of both Staphylococcus epidermidis and Staphylococcus aureus (pathogens relevant for orthopaedic and other medical device related infections) were measured. Specifically, heat treatment of 80 nm diameter titanium tubes produced the most robust antimicrobial effect of all surface treatment parameters tested. This study provides the first step toward understanding the surface properties of nano-structured titanium that improve tissue growth (as has been previously observed with nanotubular titanium), while simultaneously reducing infection without the use of pharmaceutical drugs.

  17. On a conjecture of Murty and Simon on diameter two critical graphs II

    DEFF Research Database (Denmark)

    Haynes, Teresa W.; Henning, Michael A.; Yeo, Anders

    2012-01-01

    A graph G is diameter 2-critical if its diameter is two and the deletion of any edge increases the diameter. Murty and Simon conjectured that the number of edges in a diameter 2-critical graph of order n is at most n2/4 and that the extremal graphs are complete bipartite graphs with equal size pa...

  18. Effect of Experimental Parameters on Nanofiber Diameter from Electrospinning with Wire Electrodes

    Science.gov (United States)

    Zhu, Guocheng; Zhao, L. Y.; Zhu, L. T.; Deng, X. Y.; Chen, W. L.

    2017-09-01

    Polyvinylidene Fluoride (PVDF) nanofibers were electrospun by Nanospider equipment with wire electrodes. The parameters which would influence the fiber diameter were investigated in terms of solution concentration, cartridge speed (feed rate of solution), voltage, electrode distance, rotating wire speed, winding speed and slit diameter. The morphology and diameter of fibers were observed by scanning electron microscope. The results revealed that the solution concentration had significant influence on both fiber morphology and fiber diameter; the cartridge speed, voltage, electrode distance and slit diameter had slight effect on fiber diameter since the standard deviations were large; the rotating wire speed and the winding speed had insignificant influence on fiber diameter.

  19. Acoustic Guided Wave Testing of Pipes of Small Diameters

    Science.gov (United States)

    Muravev, V. V.; Muraveva, O. V.; Strizhak, V. A.; Myshkin, Y. V.

    2017-10-01

    Acoustic path is analyzed and main parameters of guided wave testing are substanti- ated applied to pipes of small diameters. The method is implemented using longitudinal L(0,1) and torsional T(0,1) waves based on electromagnetic-acoustic (EMA) transducers. The method of multiple reflections (MMR) combines echo-through, amplitude-shadow and time-shadow methods. Due to the effect of coherent amplification of echo-pulses from defects the sensitivity to the defects of small sizes at the signal analysis on the far reflections is increased. An oppor- tunity of detection of both local defects (dents, corrosion damages, rolling features, pitting, cracks) and defects extended along the pipe is shown.

  20. Imperfection surveys on a 10-ft-diameter shell structure

    Science.gov (United States)

    Arbocz, J.; Williams, J. G.

    1977-01-01

    The results of an extensive imperfection survey on a 10-ft-diameter integrally stiffened cylindrical shell are presented. The shape of the measured initial imperfections is clearly influenced by details of the shell construction. The modal components of the measured imperfection surface as a function of the circumferential and of the axial wave numbers are calculated. The discrete axial power spectral density functions and the corresponding root-mean-square values of the imperfections are also determined for given circumferential wave numbers. Using the Fourier coefficients of the measured initial imperfections, buckling loads are calculated by solving the nonlinear Donnell-type imperfect shell equations iteratively. The calculated lowest buckling load compares favorably with the values usually recommended for similar shell structures.

  1. Molecular transport through large-diameter DNA nanopores.

    Science.gov (United States)

    Krishnan, Swati; Ziegler, Daniela; Arnaut, Vera; Martin, Thomas G; Kapsner, Korbinian; Henneberg, Katharina; Bausch, Andreas R; Dietz, Hendrik; Simmel, Friedrich C

    2016-09-23

    DNA-based nanopores are synthetic biomolecular membrane pores, whose geometry and chemical functionality can be tuned using the tools of DNA nanotechnology, making them promising molecular devices for applications in single-molecule biosensing and synthetic biology. Here we introduce a large DNA membrane channel with an ≈4 nm diameter pore, which has stable electrical properties and spontaneously inserts into flat lipid bilayer membranes. Membrane incorporation is facilitated by a large number of hydrophobic functionalizations or, alternatively, streptavidin linkages between biotinylated channels and lipids. The channel displays an Ohmic conductance of ≈3 nS, consistent with its size, and allows electrically driven translocation of single-stranded and double-stranded DNA analytes. Using confocal microscopy and a dye influx assay, we demonstrate the spontaneous formation of membrane pores in giant unilamellar vesicles. Pores can be created both in an outside-in and an inside-out configuration.

  2. Density Profile Control in a Large Diameter, Helicon Plasma

    Science.gov (United States)

    Cluggish, B. P.

    2004-11-01

    Large diameter plasmas are desirable in many applications, including semiconductor processing, surface treatment, and space propulsion. The Archimedes Plasma Mass Filter^1 is a new addition to this list. Whereas the Filter is intended for nuclear waste separation, current experiments on the Archimedes Demonstration Unit use noble gases as the feed material. Plasmas of density 2 x 10^19 m-3 can be created in axial magnetic fields up to 0.16 T by using 1.6 MW of RF power at 5-7 MHz. Creating uniform density profiles in this large (0.75 m diameter, 4 m long) device requires controlling the phase relationships between RF currents in an array of 8 antenna straps, each encircling the plasma column. When the currents in adjacent straps are in phase (i.e. in the same direction), the radial density profile is hollow with a density peak at the plasma edge. Reversing the phase on half of the straps causes the density profile to fill in and become flat. This behavior is consistent with the dispersion relation for helicon modes.^2 Alternating the phase from strap to strap reduces the axial wavelengths of the dominant RF fields, which generates helicon modes with longer radial wavelengths that are absorbed deeper in the plasma. Comparisons of the density profiles to the spectra of antenna currents will be presented, along with observations of the dependence of the plasma parameters on magnetic field, RF power, and gas pressure. Experimental results will be compared to helicon theory and computer models. ^1T. Ohkawa, "Plasma Mass Filter", U.S. Patent 6 096 220, August 1, 2000. ^2F. F. Chen, Phys. Plasmas 3, 1783, (1996)

  3. White matter microstructure from nonparametric axon diameter distribution mapping.

    Science.gov (United States)

    Benjamini, Dan; Komlosh, Michal E; Holtzclaw, Lynne A; Nevo, Uri; Basser, Peter J

    2016-07-15

    We report the development of a double diffusion encoding (DDE) MRI method to estimate and map the axon diameter distribution (ADD) within an imaging volume. A variety of biological processes, ranging from development to disease and trauma, may lead to changes in the ADD in the central and peripheral nervous systems. Unlike previously proposed methods, this ADD experimental design and estimation framework employs a more general, nonparametric approach, without a priori assumptions about the underlying form of the ADD, making it suitable to analyze abnormal tissue. In the current study, this framework was used on an ex vivo ferret spinal cord, while emphasizing the way in which the ADD can be weighted by either the number or the volume of the axons. The different weightings, which result in different spatial contrasts, were considered throughout this work. DDE data were analyzed to derive spatially resolved maps of average axon diameter, ADD variance, and extra-axonal volume fraction, along with a novel sub-micron restricted structures map. The morphological information contained in these maps was then used to segment white matter into distinct domains by using a proposed k-means clustering algorithm with spatial contiguity and left-right symmetry constraints, resulting in identifiable white matter tracks. The method was validated by comparing histological measures to the estimated ADDs using a quantitative similarity metric, resulting in good agreement. With further acquisition acceleration and experimental parameters adjustments, this ADD estimation framework could be first used preclinically, and eventually clinically, enabling a wide range of neuroimaging applications for improved understanding of neurodegenerative pathologies and assessing microstructural changes resulting from trauma. Published by Elsevier Inc.

  4. Modular Small Diameter Vascular Grafts with Bioactive Functionalities.

    Directory of Open Access Journals (Sweden)

    Meik Neufurth

    Full Text Available We report the fabrication of a novel type of artificial small diameter blood vessels, termed biomimetic tissue-engineered blood vessels (bTEBV, with a modular composition. They are composed of a hydrogel scaffold consisting of two negatively charged natural polymers, alginate and a modified chitosan, N,O-carboxymethyl chitosan (N,O-CMC. Into this biologically inert scaffold two biofunctionally active biopolymers are embedded, inorganic polyphosphate (polyP and silica, as well as gelatin which exposes the cell recognition signal, Arg-Gly-Asp (RGD. These materials can be hardened by exposure to Ca(2+ through formation of Ca(2+ bridges between the polyanions, alginate, N,O-CMC, and polyP (alginate-Ca(2+-N,O-CMC-polyP. The bTEBV are formed by pressing the hydrogel through an extruder into a hardening solution, containing Ca(2+. In this universal scaffold of the bTEBV biomaterial, polycations such as poly(L-Lys, poly(D-Lys or a His/Gly-tagged RGD peptide (three RGD units were incorporated, which promote the adhesion of endothelial cells to the vessel surface. The mechanical properties of the biopolymer material (alginate-Ca(2+-N,O-CMC-polyP-silica revealed a hardness (elastic modulus of 475 kPa even after a short incubation period in CaCl2 solution. The material of the artificial vascular grafts (bTEBVs with an outer size 6 mm and 1.8 mm, and an inner diameter 4 mm and 0.8 mm, respectively turned out to be durable in 4-week pulsatile flow experiments at an alternating pressure between 25 and 100 mbar (18.7 and 75.0 mm Hg. The burst pressure of the larger (smaller vessels was 850 mbar (145 mbar. Incorporation of polycationic poly(L-Lys, poly(D-Lys, and especially the His/Gly-tagged RGD peptide, markedly increased the adhesion of human, umbilical vein/vascular endothelial cells, EA.HY926 cells, to the surface of the hydrogel. No significant effect of the polyP samples on the clotting of human plasma is measured. We propose that the metabolically

  5. Ultrasound assessment of optic nerve sheath diameter in healthy volunteers.

    Science.gov (United States)

    Goeres, Patrick; Zeiler, Frederick A; Unger, Bertram; Karakitsos, Dimitrios; Gillman, Lawrence M

    2016-02-01

    Ultrasound assessment of optic nerve sheath diameter (ONSD) has been suggested as a non-invasive measure of intracranial pressure. Numerous small studies suggest its validity; however, discrepancy exists around normal values for ONSD. In this study we sought to define a normal value range for ONSD in a population of healthy adult volunteers. ONSD was measured in healthy adult volunteers and a normal range was defined using descriptive statistics. A regression analysis was used to determine relationship between ONSD measurements and sex, age, height and weight. One hundred twenty adults were recruited (age 18-65 [mean 29.3]) with 55 male and 65 female subjects. Mean ONSD was 3.68 mm (95% confidence interval [CI], 2.85-4.40). Upon regression analysis, mean ONSD did not vary with age, weight, or height but did vary with sex. Mean ONSD measurements for men were 3.78 mm (95% CI, 3.23-4.48) compared with 3.60 mm (95% CI, 2.83-4.11) for women. This study has defined the range of ONSD in a healthy cohort of volunteers. The lack of relationship to age, weight and height is similar to other studies but this is the first study to find a difference depending on sex suggesting the possible need for separate reference ranges for men and women. Copyright © 2015 Elsevier Inc. All rights reserved.

  6. Small diameter nozzle plasma arc as a processing tool

    Science.gov (United States)

    Kimura, T.; Komatsu, A.; Yoshioka, S.; Miyazaki, T.

    1992-06-01

    High-power-density plasma arc equipment with a small diameter nozzle of 0.1-0.3 mm has been developed, which produces power density of about 104 W/mm2 at the exit of the nozzle. The density is comparable to those produced by electron and laser beams. In the present article, development procedure, power density on the target surface, and processing capability in comparison to the conventional electron and laser beams are described. The power density as the processing heat source depends on the kind of processing. The apparent power density in cutting is of the order of 104 W/mm2; on the other hand, that in surface hardening is of the order of 102 W/mm2. The processing capability for causing melting such as cutting and welding does not depend on the working distance, which is defined as the distance between the torch and target material; furthermore, the deviation of the torch from the correct position does not affect the processing capability. The equipment developed is suitable for an automated production system because high precision position control of the torch is not required.

  7. A 24mm diameter fibre positioner for spectroscopic surveys

    Science.gov (United States)

    Hörler, Philipp; Kronig, Luzius; Kneib, Jean-Paul; Bleuler, Hannes; Bouri, Mohamed

    2016-07-01

    One of the big research topics in modern cosmology is the mystery of dark Energy. To unveil the secret, cosmologists want to measure precisely the evolution of large scale structures in the universe. One way of doing so is to measure the 3D location of a high number of galaxies. By measuring the redshift of a galaxy, it is possible to find its distance. In order to measure a high number of galaxies in a practical amount of time, we need to observe multiple objects in parallel. Instead of a spectrograph, thousands of optical fibres are placed in the focal plane of a telescope. They will transmit the light of many objects to a spectrograph. Each fibre has to be positioned to several μm precision in the focal plane of a telescope for each exposure. Each fibre is positioned by a 2-axis fibre positioner. In this paper such a fibre positioner with 24-mm diameter is presented. It is driven by two brushless DC motors in combination with a backlash free gearbox. The positioner has an optimal central fibre path and improved angular alignment. The fibre runs through the centre of the positioner and is only bent at the top to reach its target position. In this way, the flexion and torsion of the fibre are minimal. In addition to the high positioning accuracy, the design is optimized to allow a minimal tilt error of the fibre. This is demonstrated using a novel optical tilt measurement system.

  8. Aggregate Morphology Evolution by Sintering: Number & Diameter of Primary Particles.

    Science.gov (United States)

    Eggersdorfer, Max L; Kadau, Dirk; Herrmann, Hans J; Pratsinis, Sotiris E

    2012-04-01

    The structure of fractal-like agglomerates (physically-bonded) and aggregates (chemically- or sinter-bonded) is important in aerosol synthesis of nanoparticles, and in monitoring combustion emissions and atmospheric particles. It influences also particle mobility, scattering, and eventually performance of nanocomposites, suspensions and devices made with such particles. Here, aggregate sintering by viscous flow of amorphous materials (silica, polymers) and grain boundary diffusion of crystalline ceramics (titania, alumina) or metals (Ni, Fe, Ag etc.) is investigated. A scaling law is found between average aggregate projected area and equivalent number of constituent primary particles during sintering: from fractal-like agglomerates to aggregates and eventually compact particles (e.g. spheres). This is essentially a relation independent of time, material properties and sintering mechanisms. It is used to estimate the equivalent primary particle diameter and number in aggregates. The evolution of aggregate morphology or structure is quantified by the effective fractal dimension (Df ) and mass-mobility exponent (Dfm ) and the corresponding prefactors. The Dfm increases monotonically during sintering converging to 3 for a compact particle. Therefore Dfm and its prefactor could be used to gauge the degree or extent of sintering of agglomerates made by a known collision mechanism. This analysis is exemplified by comparison to experiments of silver nanoparticle aggregates sintered at different temperatures in an electric tube furnace.

  9. Comparison of CT-Determined Pulmonary Artery Diameter, Aortic Diameter, and Their Ratio in Healthy and Diverse Clinical Conditions.

    Directory of Open Access Journals (Sweden)

    Sang Hoon Lee

    Full Text Available The main pulmonary artery diameter (mPA, aortic diameter (Ao, and the mPA/Ao ratio, easily measured using chest computed tomography (CT, provide information that enables the diagnosis and evaluation of cardiopulmonary diseases. Here, we used CT to determine the sex- and age-specific distribution of normal reference values for mPA, Ao, and mPA/Ao ratio in an adult Korean population.Data from non-contrast, ECG-gated, coronary-calcium-scoring CT images of 2,547 individuals who visited the Health Screening Center of the Severance Hospital were analyzed. Healthy individuals (n = 813 included those who do not have hypertension, diabetes, asthma, obstructive lung disease, ischemic heart disease, stroke, smoking, obesity, and abnormal CT findings. Both mPA and Ao were measured at the level of bifurcation of the main pulmonary artery.The mean mPA and Ao were 25.9 mm and 30.0 mm in healthy participants, respectively, while the mean mPA/Ao ratio was 0.87. Medical conditions associated with a larger mPA were male, obesity, smoking history, hypertension, and diabetes. A larger mPA/Ao ratio was associated with female, the obese, non-smoker, normotensive, and normal serum level of lipids, while a smaller mPA/Ao ratio was associated with older age. In healthy individuals, the 90th percentile sex-specific mPA, Ao, and mPA/Ao ratio were, 31.3 mm (95% CI 29.9-32.2, 36.8 mm (95% CI 35.7-37.5, and 1.05 (95% CI 0.99-1.07 in males, and 29.6 mm (95% CI 29.1-30.2, 34.5 mm (95% CI 34.1-34.9, and 1.03 (95% CI 1.02-1.06 in females, respectively.In the Korean population, the mean mPA reference values in male and female were 26.5 mm and 25.8 mm, respectively, while the mean mPA/Ao ratio was 0.87. These values were influenced by a variety of underlying medical conditions.

  10. Quality control on crimping of large diameter welding pipe

    Science.gov (United States)

    Fan, Lifeng; Gao, Ying; Li, Qiang; Xu, Hongshen

    2012-11-01

    Crimping is used in production of large diameter submerged-arc welding pipes. Many researches are focused on crimping in certain manufacturing mode of welding pipe. The application scopes of research achievements become limited due to lack of uniformity in theoretical analysis. In order to propose a crimping prediction method in order to control forming quality, the theory model of crimping based on elastic-plastic mechanics is established. The main technical parameters are determined by theoretical analysis, including length of crimping, base radius of punch, terminal angle of punch, base radius of die, terminal angle of die and horizontal distance between punch and die. In addition, a method used to evaluate the forming quality is presented, which investigates the bending angle after springback, forming force, straight edge length and equivalent radius of curvature. In order to investigate the effects of technical parameters on forming quality, a two-dimensional finite element model is established by finite element software ABAQUS. The finite element model is verified in that its shapes error is less than 5% by comparable experiments, which shows that their geometric precision meets demand. The crimping characteristics is obtained, such as the distribution of stress and strain and the changes of forming force, and the relation curves of technical parameters on forming quality are given by simulation analysis. The sensitivity analysis indicates that the effects of length of crimping, technical parameters of punch on forming quality are significant. In particular, the data from simulation analysis are regressed by response surface method (RSM) to establish prediction model. The feasible technical parameters are obtained from the prediction model. This method presented provides a new thought used to design technical parameters of crimping forming and makes a basis for improving crimping forming quality.

  11. Saqqar: A 34 km diameter impact structure in Saudi Arabia

    Science.gov (United States)

    Kenkmann, Thomas; Afifi, Abdulkader M.; Stewart, Simon A.; Poelchau, Michael H.; Cook, Douglas J.; Neville, Allen S.

    2015-11-01

    Here we present the first proof of an impact origin for the Saqqar circular structure in northwestern Saudi Arabia (Neville et al. ), with an apparent diameter of 34 km, centered at 29°35'N, 38°42'E. The structure is formed in Cambrian-Devonian siliciclastics and is unconformably overlain by undeformed Cretaceous and Paleogene sediments. The age of impact is not well constrained and lies somewhere between 410 and 70 Ma. The subsurface structure is constrained by 2-D reflection seismic profiles and six drilled wells. First-order structural features are a central uplift that rises approximately 2 km above regional datums, surrounded by a ring syncline. The crater rim is defined by circumferential normal faults. The central uplift and ring syncline correspond to a Bouguer gravity high and an annular ring-like low, respectively. The wells were drilled within the central uplift, the deepest among them exceed 2 km depth. Sandstone core samples from these wells show abundant indicators of a shock metamorphic overprint. Planar deformation features (PDFs) were measured with orientations along (0001), {101¯3}, and less frequently along {101¯1} and {101¯4}. Planar fractures (PFs) predominantly occur along (0001) and {101¯1}, and are locally associated with feather features (FFs). In addition, some shocked feldspar grains and strongly deformed mica flakes were found. The recorded shock pressure ranges between 5 and 15 GPa. The preserved level of shock and the absence of an allochthonous crater fill suggest that Saqqar was eroded by 1-2 km between the Devonian and Maastrichtian. The documentation of unequivocal shock features proves the formation of the Saqqar structure by a hypervelocity impact event.

  12. Solar Diameter Measurements from Eclipses as a Solar Variability Proxy

    Science.gov (United States)

    Waring Dunham, David; Sofia, Sabatino; Guhl, Konrad; Herald, David Russell

    2015-08-01

    Since thermal relaxation times for the Sun are thousands of years, small variations of the Solar intensity are proportional to small variations of the Solar diameter on decadal time scales. In a combination between observations and theory, reliable values of the relation constant W are known, that allow transformation of historical variations of radius into variations of the solar luminosity. During the past 45 years, members of the International Occultation Timing Association (IOTA) have observed 20 annular and total solar eclipses from locations near the path edges. Baily’s beads, whose occurrence and duration are considerably prolonged as seen from path edge locations, were first timed visually, mostly using projection techniques, but since about 1980, they have been timed mainly from analysis of video recordings. The edge locations have the advantage that most of the beads are defined by the same features in the lunar polar regions that cause the phenomena at each eclipse. Some of the best-observed modern eclipses can be used to assess the accuracy of the results, which are limited mainly by the intensity drop at the Sun’s edge, and the consequent uncertainty in defining the edge. In addition, direct visual contact timings made near the path edges during earlier eclipses, back to 1715, have been found in the literature, and analyzed. Although the observations seem to show small variations, they are only a little larger than the assessed accuracies. The results can be improved with a consistent re-analysis of the observations using the much more accurate lunar profile data that is now available from the Japanese Kaguya and NASA’s LRO lunar orbiter observations. Also, IOTA has plans to observe future eclipses with a variety of techniques that were used in the past, to better assess the accuracies of the different observational methods that have been used, and determine any systematic differences between them.

  13. IMPS albedo and diameter for Asteroid 243 Ida

    Science.gov (United States)

    Veeder, G. J.; Tedesco, E. F.

    1993-01-01

    243 Ida is the second asteroid target of the Galileo mission. The Infrared Astronomical Satellite (IRAS) detected Ida several times during its 1983 sky survey. The IRAS Minor Planet Survey (IMPS) yields a total of 13 usable observations during 6 sightings of Ida. These data result in a geometric visual albedo of 0.24 and a mean diameter of 28 km for Ida. The IMPS catalog updates and extends the IRAS Asteroid and Comet Survey through asteroid number 4679. File versions of IMPS final products will be available from the National Space Science Data Center (NSSDC). The input for IMPS processing includes updated visual absolute magnitudes and orbital elements for each asteroid. H and G are 9.94 and 0.15 for Ida. IMPS also includes a correction for low flux densities (less than approximately 1 Jansky). In the case of Ida, 3 observations at 12 microns, 6 at 25 microns, and 4 at 60 microns were considered acceptable for analysis. Most of these do have flux densities less than 1 Jansky with a value of approximately 5 for their estimated SNR. The 25 microns observations as plotted in the figure are consistent with the variation expected for the cross section of Ida with rotation. Ida is a main belt asteroid with an S taxonomic classification. The spectra of S asteroids tend to be dominated by pyroxene with visual albedos from 0.1 to 0.3. The IMPS average albedo of 0.24 (plus or minus 0.07) for 243 Ida is in the upper range observed for S asteroids.

  14. Integrated spectral study of small angular diameter galactic open clusters

    Science.gov (United States)

    Clariá, J. J.; Ahumada, A. V.; Bica, E.; Pavani, D. B.; Parisi, M. C.

    2017-10-01

    This paper presents flux-calibrated integrated spectra obtained at Complejo Astronómico El Leoncito (CASLEO, Argentina) for a sample of 9 Galactic open clusters of small angular diameter. The spectra cover the optical range (3800-6800 Å), with a resolution of ∼14 Å. With one exception (Ruprecht 158), the selected clusters are projected into the fourth Galactic quadrant (282o age by comparing the continuum distribution and line strenghts of the cluster spectra with those of template cluster spectra with known parameters. We thus provide spectroscopic information independent from that derived through color-magnitude diagram studies. We found three clusters (Collinder 249, NGC 4463 and Ruprecht 122) younger than ∼40 Myr, four moderately young ones (BH 92, Harvard 5, Hogg 14 and Pismis 23) with ages within 200-400 Myr, and two intermediate-age ones (Ruprecht 158 and ESO 065-SC07) with ages within 1.0-2.2 Gyr. The derived foreground E(B - V) color excesses vary from around 0.0 in Ruprecht 158 to ∼1.1 in Pismis 23. In general terms, the results obtained show good agreement with previous photometric results. In Ruprecht 158 and BH 92, however, some differences are found between the parameters here obtained and previous values in the literature. Individual spectra of some comparatively bright stars located in the fields of 5 out of the 9 clusters here studied, allowed us to evaluate their membership status. The current cluster sample complements that of 46 open clusters previously studied by our group in an effort to gather a spectral library with several clusters per age bin. The cluster spectral library that we have been building is an important tool to tie studies of resolved and unresolved stellar content.

  15. Bark thickness related to tree diameter in sugar maple (Acer saccharum Marsh.)

    Science.gov (United States)

    H. Clay Smith

    1969-01-01

    Bark thickness for sugar maple trees in Vermont was found to be related to tree diameter at breast height (d.b.h.). The relationship was positive-as the diameter increased, the bark thickness increased.

  16. Bloch-Wave Engineered Submicron Diameter Micropillars with Quality Factors Exceeding 10,000

    DEFF Research Database (Denmark)

    Hofling, S.; Lermer, M.; Gregersen, Niels

    2011-01-01

    Adiabatic design submicron diameter quantum-dot micropillars have been designed and implemented for cavity quantum electrodynamics experiments. Ultra-high experimental quality factors (>10,000) are obtained for submicron diameters and strong light-matter interaction is observed.......Adiabatic design submicron diameter quantum-dot micropillars have been designed and implemented for cavity quantum electrodynamics experiments. Ultra-high experimental quality factors (>10,000) are obtained for submicron diameters and strong light-matter interaction is observed....

  17. Modeling individual tree growth by fusing diameter tape and increment core data

    Science.gov (United States)

    Erin M. Schliep; Tracy Qi Dong; Alan E. Gelfand; Fan. Li

    2014-01-01

    Tree growth estimation is a challenging task as difficulties associated with data collection and inference often result in inaccurate estimates. Two main methods for tree growth estimation are diameter tape measurements and increment cores. The former involves repeatedly measuring tree diameters with a cloth or metal tape whose scale has been adjusted to give diameter...

  18. Basic maneuvers for an inspection robot for small diameter gas distribution mains

    NARCIS (Netherlands)

    Dertien, Edwin Christian; Stramigioli, Stefano

    2011-01-01

    This video shows the design of a mechanical structure of a miniature pipe inspection robot (MPR) capable of moving trough very small pipes (up to 41 mm inner diameter) as well as a wide range of diameters (63 to 125 mm outer diameter). The requirement to negotiate bends, T-joints and steep

  19. The Diameter of Retinal Vessels Is Affected by Transient Ischemia of the Arm in Normal Persons

    DEFF Research Database (Denmark)

    El Dabagh, Yasmin; Petersen, Line; Pedersen, Michael

    2017-01-01

    the diameter of normal retinal vessels can be used as a marker of RIC in vivo. Methods: In 20 normal persons aged 20 to 31 years the Dynamic Vessel Analyzer (DVA) was used to measure the resting diameter and diameter changes during isometric exercise and flicker stimulation before, immediately after, and 1...

  20. Mixed-effects height–diameter models for ten conifers in the inland ...

    African Journals Online (AJOL)

    To demonstrate the utility of mixed-effects height–diameter models when conducting forest inventories, mixedeffects height–diameter models are presented for several commercially and ecologically important conifers in the inland Northwest of the USA. After obtaining height–diameter measurements from a plot/stand of ...

  1. 78 FR 60897 - Certain Welded Large Diameter Line Pipe From Japan

    Science.gov (United States)

    2013-10-02

    ... COMMISSION Certain Welded Large Diameter Line Pipe From Japan Determination On the basis of the record \\1... the antidumping duty order on certain welded large diameter line pipe from Japan would likely to lead... Certain Welded Large Diameter Line Pipe from Japan: Investigation No. 731-TA-919 (Second Review). By order...

  2. Selective control of small versus large diameter axons using infrared laser light (Conference Presentation)

    Science.gov (United States)

    Lothet, Emilie H.; Shaw, Kendrick M.; Horn, Charles C.; Lu, Hui; Wang, Yves T.; Jansen, E. Duco; Chiel, Hillel J.; Jenkins, Michael W.

    2016-03-01

    Sensory information is conveyed to the central nervous system via small diameter unmyelinated fibers. In general, smaller diameter axons have slower conduction velocities. Selective control of such fibers could create new clinical treatments for chronic pain, nausea in response to chemo-therapeutic agents, or hypertension. Electrical stimulation can control axonal activity, but induced axonal current is proportional to cross-sectional area, so that large diameter fibers are affected first. Physiologically, however, synaptic inputs generally affect small diameter fibers before large diameter fibers (the size principle). A more physiological modality that first affected small diameter fibers could have fewer side effects (e.g., not recruiting motor axons). A novel mathematical analysis of the cable equation demonstrates that the minimum length along the axon for inducing block scales with the square root of axon diameter. This implies that the minimum length along an axon for inhibition will scale as the square root of axon diameter, so that lower radiant exposures of infrared light will selectively affect small diameter, slower conducting fibers before those of large diameter. This prediction was tested in identified neurons from the marine mollusk Aplysia californica. Radiant exposure to block a neuron with a slower conduction velocity (B43) was consistently lower than that needed to block a faster conduction velocity neuron (B3). Furthermore, in the vagus nerve of the musk shrew, lower radiant exposure blocked slow conducting fibers before blocking faster conducting fibers. Infrared light can selectively control smaller diameter fibers, suggesting many novel clinical treatments.

  3. Height-diameter allometry of tropical forest trees

    Directory of Open Access Journals (Sweden)

    T. R. Feldpausch

    2011-05-01

    Full Text Available Tropical tree height-diameter (H:D relationships may vary by forest type and region making large-scale estimates of above-ground biomass subject to bias if they ignore these differences in stem allometry. We have therefore developed a new global tropical forest database consisting of 39 955 concurrent H and D measurements encompassing 283 sites in 22 tropical countries. Utilising this database, our objectives were:

    1. to determine if H:D relationships differ by geographic region and forest type (wet to dry forests, including zones of tension where forest and savanna overlap.

    2. to ascertain if the H:D relationship is modulated by climate and/or forest structural characteristics (e.g. stand-level basal area, A.

    3. to develop H:D allometric equations and evaluate biases to reduce error in future local-to-global estimates of tropical forest biomass.

    Annual precipitation coefficient of variation (PV, dry season length (SD, and mean annual air temperature (TA emerged as key drivers of variation in H:D relationships at the pantropical and region scales. Vegetation structure also played a role with trees in forests of a high A being, on average, taller at any given D. After the effects of environment and forest structure are taken into account, two main regional groups can be identified. Forests in Asia, Africa and the Guyana Shield all have, on average, similar H:D relationships, but with trees in the forests of much of the Amazon Basin and tropical Australia typically being shorter at any given D than their counterparts elsewhere. The region-environment-structure model with the lowest Akaike's information criterion and lowest deviation estimated stand-level H across all plots to within amedian −2.7 to 0.9% of the true value. Some of the plot-to-plot variability in

  4. High-resolution computed tomography evaluation of the bronchial lumen to vertebral body diameter and pulmonary artery to vertebral body diameter ratios in anesthetized ventilated normal cats.

    Science.gov (United States)

    Lee-Fowler, Tekla M; Cole, Robert C; Dillon, A Ray; Tillson, D Michael; Garbarino, Rachel; Barney, Sharron

    2017-10-01

    Objectives Bronchial lumen to pulmonary artery diameter (BA) ratio has been utilized to investigate pulmonary pathology on high-resolution CT images. Diseases affecting both the bronchi and pulmonary arteries render the BA ratio less useful. The purpose of the study was to establish bronchial lumen diameter to vertebral body diameter (BV) and pulmonary artery diameter to vertebral body diameter (AV) ratios in normal cats. Methods Using high-resolution CT images, 16 sets of measurements (sixth thoracic vertebral body [mid-body], each lobar bronchi and companion pulmonary artery diameter) were acquired from young adult female cats and 41 sets from pubertal female cats. Results Young adult and pubertal cat BV ratios were not statistically different from each other in any lung lobe. Significant differences between individual lung lobe BV ratios were noted on combined age group analysis. Caudal lung lobe AV ratios were significantly different between young adult and pubertal cats. All other lung lobe AV ratios were not significantly different. Caudal lung lobe AV ratios were significantly different from all other lung lobes but not from each other in both the young adult and pubertal cats. Conclusions and relevance BV ratio reference intervals determined for individual lung lobes could be applied to both young adult and pubertal cats. Separate AV ratios for individual lung lobes would be required for young adult and pubertal cats. These ratios should allow more accurate evaluation of cats with concurrent bronchial and pulmonary arterial disease.

  5. A Fractal Model for the Maximum Droplet Diameter in Gas-Liquid Mist Flow

    Directory of Open Access Journals (Sweden)

    Xiao-Hua Tan

    2013-01-01

    Full Text Available Distribution characteristics of liquid droplet size are described using the fractal theory for liquid droplet size distribution in gas-liquid mist flow. Thereby, the fractal expression of the maximum droplet diameter is derived. The fractal model for maximum droplet diameter is obtained based on the internal relationship between maximum droplet diameter and the droplet fractal dimension, which is obtained by analyzing the balance between total droplet surface energy and total gas turbulent kinetic energy. Fractal model predictions of maximum droplet diameter agree with the experimental data. Maximum droplet diameter and droplet fractal dimension are both found to be related to the superficial velocity of gas and liquid. Maximum droplet diameter decreases with an increase in gas superficial velocity but increases with an increase in liquid superficial velocity. Droplet fractal dimension increases with an increase in gas superficial velocity but decreases with an increase in liquid superficial velocity. These are all consistent with the physical facts.

  6. Diameter Tuning of Single-Walled Carbon Nanotubes by Diffusion Plasma CVD

    Directory of Open Access Journals (Sweden)

    Toshiaki Kato

    2011-01-01

    Full Text Available We have realized a diameter tuning of single-walled carbon nanotubes (SWNTs by adjusting process gas pressures with plasma chemical vapor deposition (CVD. Detailed photoluminescence measurements reveal that the diameter distribution of SWNTs clearly shifts to a large-diameter region with an increase in the pressure during plasma CVD, which is also confirmed by Raman scattering spectroscopy. Based on the systematical investigation, it is found that the main diameter of SWNTs is determined by the pressure during the heating in an atmosphere of hydrogen and the diameter distribution is narrowed by adjusting the pressure during the plasma generation. Our results could contribute to an application of SWNTs to high-performance thin-film transistors, which requires the diameter-controlled semiconductor-rich SWNTs.

  7. Automatic calculation of tree diameter from stereoscopic image pairs using digital image processing.

    Science.gov (United States)

    Yi, Faliu; Moon, Inkyu

    2012-06-20

    Automatic operations play an important role in societies by saving time and improving efficiency. In this paper, we apply the digital image processing method to the field of lumbering to automatically calculate tree diameters in order to reduce culler work and enable a third party to verify tree diameters. To calculate the cross-sectional diameter of a tree, the image was first segmented by the marker-controlled watershed transform algorithm based on the hue saturation intensity (HSI) color model. Then, the tree diameter was obtained by measuring the area of every isolated region in the segmented image. Finally, the true diameter was calculated by multiplying the diameter computed in the image and the scale, which was derived from the baseline and disparity of correspondence points from stereoscopic image pairs captured by rectified configuration cameras.

  8. The Relationships Between Diameter Stump Height (d0.30 and Diameter Breast Height (d1.30 for Scotch Pine (Pinus sylvestris (L. in West Black Sea RegionThe Relationships Between Diameter Stump Height (d0.30 and Diameter Breast Height (d1.30 for Scotc

    Directory of Open Access Journals (Sweden)

    Muammer Şenyurt

    2012-04-01

    Full Text Available In this study, it is proposed to determine the relationship between the diameter at stump height (d0.3 and diameter breast height (d1.30 for Scotch Pine (Pinus sylvestris (L. in West Black Sea Region including Kastamonu, Bolu and Ankara forest regional offices. For this purpose, 101 temporary sample plots were obtained and 1111 tree measurements for stump height (d0.3 and diameter breast height (d1.3 were carried out. The different regression models were selected and compared to some success criteria. The most successful results were achieved with the parabolic equation. This regression model explains 96.7 % of the variability in diameter breast height (d1.3. It is concluded that the model predicting the diameter at breast height from diameter at stump height (d0.3 can be used confidentially.

  9. Risk of dislocation using large- vs. small-diameter femoral heads in total hip arthroplasty

    Directory of Open Access Journals (Sweden)

    Plate Johannes F

    2012-10-01

    Full Text Available Abstract Background Dislocation remains a difficult problem in total hip arthroplasty. Large-diameter femoral heads may lower the incidence of dislocation by enhancing the jump distance and decreasing impingement, but their performance against small-diameter heads has not been assessed. This study compared the mid-term radiographic and functional outcomes of two matched cohorts of patients undergoing total hip arthroplasty who had a high pre-operative risk for dislocation and who received either small-diameter (26- or 28-millimeters or large-diameter (≥36-millimeters femoral heads. Methods All patients who received large-diameter heads (≥36-millimeter between 2002 and 2005, and who had pre-operative risk factors for dislocation, were identified in the institution’s joint registry. Forty-one patients (52 hips who received large-diameter heads were identified, and these patients were matched to 48 patients (52 hips in the registry who received small-diameter femoral heads. Results At mean final follow-up of 62 months (range, 49 to 101 months, both groups achieved excellent functional outcomes as measured by Harris Hip scores, with slightly better final scores in the large-diameter group (90 vs. 83 points. No patient showed any radiographic signs of loosening. No patient dislocated in the large-diameter femoral head group; the smaller-diameter group had a greater rate of dislocation (3.8%, 2 out of 52. Conclusions Large-diameter femoral head articulations may reduce dislocation rates in patients who have a high pre-operative risk for dislocation while providing the same functional improvements and safety as small-diameter bearings.

  10. Three-dimensional workstation is useful for measuring the correct size of abdominal aortic aneurysm diameters.

    Science.gov (United States)

    Ihara, Tsutomu; Komori, Kimihiro; Yamamoto, Kiyohito; Kobayashi, Masayoshi; Banno, Hiroshi; Kodama, Akio

    2013-02-01

    Abdominal aortic aneurysm diameter is usually measured by the maximum minor-axis diameter on axial computed tomography (CT). However, this "traditional" diameter may underestimate the real size, as the aorta is not always straight and the aneurysm shape is sometimes in the form of an ellipse along the cross section. Therefore, we measured maximum major-axis diameters using a three-dimensional (3D) workstation and compared them with the traditional maximum minor-axis diameters measured using thin-slice axial CT. CT data of 141 AAA patients (with fusiform aneurysms) were stored in a 3D workstation. These thin-slice CT images were reviewed on the 3D workstation to obtain curved multiplanar reconstruction images (CPR images). Using the CPR images, we measured the maximum major-axis and minor-axis diameters on CPR and the angle of the aneurysms to the body axis. The mean traditional maximum minor-axis diameter was 51.2 ± 8.2 mm, whereas the mean maximum major-axis diameter on CPR was 54.7 ± 10.1 mm. Sixty eight patients had a mean aneurysm size of 55 mm on CPR. The measurement of the traditional maximum minor-axis diameter of aneurysms is useful in the case of most patients. However, the traditional maximum minor-axis diameter may underestimate the real aneurysmal diameter, particularly in patients with an ellipse-shaped aneurysm. The maximum major-axis diameter as measured using CPR images is effective for representing the real aneurysmal size. Copyright © 2013 Elsevier Inc. All rights reserved.

  11. Risk of dislocation using large- vs. small-diameter femoral heads in total hip arthroplasty

    Science.gov (United States)

    2012-01-01

    Background Dislocation remains a difficult problem in total hip arthroplasty. Large-diameter femoral heads may lower the incidence of dislocation by enhancing the jump distance and decreasing impingement, but their performance against small-diameter heads has not been assessed. This study compared the mid-term radiographic and functional outcomes of two matched cohorts of patients undergoing total hip arthroplasty who had a high pre-operative risk for dislocation and who received either small-diameter (26- or 28-millimeters) or large-diameter (≥36-millimeters) femoral heads. Methods All patients who received large-diameter heads (≥36-millimeter) between 2002 and 2005, and who had pre-operative risk factors for dislocation, were identified in the institution’s joint registry. Forty-one patients (52 hips) who received large-diameter heads were identified, and these patients were matched to 48 patients (52 hips) in the registry who received small-diameter femoral heads. Results At mean final follow-up of 62 months (range, 49 to 101 months), both groups achieved excellent functional outcomes as measured by Harris Hip scores, with slightly better final scores in the large-diameter group (90 vs. 83 points). No patient showed any radiographic signs of loosening. No patient dislocated in the large-diameter femoral head group; the smaller-diameter group had a greater rate of dislocation (3.8%, 2 out of 52). Conclusions Large-diameter femoral head articulations may reduce dislocation rates in patients who have a high pre-operative risk for dislocation while providing the same functional improvements and safety as small-diameter bearings. PMID:23039109

  12. Estimation of a tube diameter in a `church window' condenser based on entropy generation minimization

    Science.gov (United States)

    Laskowski, Rafał; Rusowicz, Artur; Grzebielec, Andrzej

    2015-09-01

    The internal diameter of a tube in a `church window' condenser was estimated using an entropy generation minimization approach. The adopted model took into account the entropy generation due to heat transfer and flow resistance from the cooling-water side. Calculations were performed considering two equations for the flow resistance coefficient for four different roughness values of a condenser tube. Following the analysis, the internal diameter of the tube was obtained in the range of 17.5 mm to 20 mm (the current internal diameter of the condenser tube is 22 mm). The calculated diameter depends on and is positively related to the roughness assumed in the model.

  13. Height-diameter relationships of tropical Atlantic moist forest trees in southeastern Brazil

    Directory of Open Access Journals (Sweden)

    Marcos Augusto da Silva Scaranello

    2012-02-01

    Full Text Available Site-specific height-diameter models may be used to improve biomass estimates for forest inventories where only diameter at breast height (DBH measurements are available. In this study, we fit height-diameter models for vegetation types of a tropical Atlantic forest using field measurements of height across plots along an altitudinal gradient. To fit height-diameter models, we sampled trees by DBH class and measured tree height within 13 one-hectare permanent plots established at four altitude classes. To select the best model we tested the performance of 11 height-diameter models using the Akaike Information Criterion (AIC. The Weibull and Chapman-Richards height-diameter models performed better than other models, and regional site-specific models performed better than the general model. In addition, there is a slight variation of height-diameter relationships across the altitudinal gradient and an extensive difference in the stature between the Atlantic and Amazon forests. The results showed the effect of altitude on tree height estimates and emphasize the need for altitude-specific models that produce more accurate results than a general model that encompasses all altitudes. To improve biomass estimation, the development of regional height-diameter models that estimate tree height using a subset of randomly sampled trees presents an approach to supplement surveys where only diameter has been measured.

  14. Effects of pellet diameter during and after lactation on feed intake of piglets pre- and postweaning.

    Science.gov (United States)

    van den Brand, H; Wamsteeker, D; Oostindjer, M; van Enckevort, L C M; van der Poel, A F B; Kemp, B; Bolhuis, J E

    2014-09-01

    Effects of 2 pellet diameters for piglets pre- and postweaning on feed intake, BW, and feed-related behavior were studied in 3 experiments. In Exp. 1, 19 litters were provided with pellets of 2 and 12 mm in diameter in a choice-feeding setup from d 4 of lactation onward. From d 4 to 18, piglets preferred the 12-mm diameter pellet over the 2-mm diameter pellet (519 vs. 168 g/pen; P Piglet BW at weaning did not differ between treatments. Treatment × day of lactation interactions were found for time spent eating, interest in eating, and time spent suckling. Time spent eating and interest in eating increased with time. This increase was lower in the litters provided with the 10-mm diameter pellet. Time spent suckling remained the same in litters provided with 2-mm diameter pellets but decreased in time in litters provided the 10-mm diameter pellets. Experiment 3 was set up as a 2 × 2 factorial design with pellet diameter both pre- and postweaning as factors. During lactation, 18 litters were provided creep feed of either 2 or 12 mm in pellet diameter. At weaning, each litter was split into 2 comparable half litters and each half litter was provided with feed of 2 or 12 mm in diameter. Feed intake was higher in the 12-mm diameter pellet litters than in the 2-mm ones from d 4 to 11 of lactation (P weaning did not affect BW gain or feed intake. Piglets provided the 12-mm diameter pellet before weaning, however, had a higher BW gain (2,060 vs. 2,606 g/pig; P = 0.003) and feed intake (2,772 vs. 3,173 g/pig; P = 0.04) and a lower feed conversion ratio (P = 0.03) between d 0 and 10 after weaning than piglets provided the 2-mm diameter pellet before weaning. Postweaning pellet diameter had no effect on BW gain or feed intake. Behavior was not affected by pellet diameter pre- and postweaning. We conclude that young piglets (weaning were higher in piglets provided with a large pellet diameter during lactation, possibly due to the higher creep feed intake in early lactation.

  15. Portal venous diameter in children: Normal limits according to age, weight and height

    Energy Technology Data Exchange (ETDEWEB)

    Soyupak, Sureyya, E-mail: sureyya@cu.edu.t [Cukurova University Hospital Radiology Department, Adana, 01330 (Turkey); Gunesli, Aylin [Cukurova University Hospital Radiology Department, Adana, 01330 (Turkey); Seydaoglu, Guelsah [Cukurova Universty Medical School, Medical Statitics Department, Adana (Turkey); Binokay, Figen; Celiktas, Medih; Inal, Mehmet [Cukurova University Hospital Radiology Department, Adana, 01330 (Turkey)

    2010-08-15

    Purpose: To establish the normal limits of portal vein diameter according to age, height and weight. Materials and methods: One hundred and sixty-eight healthy children, ages ranging from 1 month to 15 years were examined by ultrasound. Portal vein diameters at hepatic port, weight and height were recorded. Results: A range of normal limits for portal veneous diameter according to age, weight and height are obtained and presented in tables. Conclusion: Knowing the normals for portal venous diameter in every age group in children is mandatory in differentiating disease. The tables according to age, weight and height will definitely be helpful in the work-up process.

  16. Effecat of Porou Diameter on Effective Thermal Conductivity and Permeability of Porous Medium

    Science.gov (United States)

    Miyazawa, Toshiyoshi; Ichimiya, Koichi

    Effective thermal conductivity and permeability of a porous medium were examined as a function of porous diameter at constant porosity. If the porous diameter increases at constant porosity, the number of pore should reduce and as the result the contact area to solid material also decreases. Effect of solid material becomes large and effective thermal conductivity increases. This tendency was experimentally confirmed by using three kinds of ceramic material (porous diameter df=1.3mm, 2.0mm and 4.2 mm, porosity &epsilon = 87%). In addition, permeability was determined experimentally for various porous diameters by using Ergun's equation including viscous term and kinetic term.

  17. Crown-Stump Diameter Model for Parkia biglobosa Benth. Species in Makurdi, Benue State, Nigeria

    Directory of Open Access Journals (Sweden)

    O. Chukwu

    2017-07-01

    Full Text Available The crown of tree is the centre of physiological activity which gives an indication of the potential photosynthetic capacity on a tree. Though, its measurement remains a challenge in forest inventory task. The ability to predict crown diameter from stump diameter provides an effective technique of obtaining its estimate. This helps in detecting the excessive tree felling than actual requirements and wildlife suitability.The main objective of this study was to develop and test crown diameter prediction models for silvicultural management of naturally grown Parkia biglobosa within the University of Agriculture, Makurdi. Nine 100 m x 100 m temporary sample plots were established using simple random sampling method. Crown diameter and stump diameter were measured in all living P. biglobosa trees with stump diameter ≥10.0 cm. Least square method was used to convert the counted stumps into harvested crown dimension. Three linear and three non-linear models using stump diameter as the exploratory variable were developed and evaluated using the adjusted coefficient of determination (Adj.R2, standard error of estimate (SEE, prediction error sum of squares (PRESS and Akaike information criterion (AIC. The crown-stump diameter relationship was best described by the double logarithmic function with .The result showed that Crown diameter estimation was feasible even when the only information available is stump diameter.The resulting equation was tested for validation with independent data obtained from additional plots and was found to be desirable for estimating the crown diameter for Parkia biglobosa in Makurdi, Benue State, Nigeria.

  18. Pengujian Tarik Dan Impak Pada Pengerjaan Pengelasan SMAW Dengan Mesin Genset Menggunakan Diameter Elektroda Yang Berbeda

    Directory of Open Access Journals (Sweden)

    M Zaenal Mawahib

    2017-02-01

    Full Text Available Pengaruh hasil sumber daya listrik yang dihasilkan dari mesin genset yaitu kemungkinan terjadinya lubang cacing dan retak, dan apabila arus yang terlalu rendah akan mengakibatkan kurangnya penembusan dan kemungkinan terak terperangkap tinggi, sehingga dapat mengakibatkan kekuatan dari sambungan lasan yang rendah. Pengujian pada sambungan pengelasan  yang berbeda diameter elektroda dengan menggunakan mesin genset, akan diperoleh kekuatan tarik dan kekuatan impak maksimum dari masing-masing material uji dan dapat diketahui pemilihan diameter elektroda yang paling baik digunakan untuk masing-masing pelat. Pengelasan menggunakan jenis sambungan butt joint (single V-groove dengan sudut 600, dengan diameter elektroda 3,2 mm dan 4 mm dengan tebal masing-masing material uji 8 mm dan 10 mm. Hasil pengujian didapatkan kuat tarik dari diameter elektroda 3,2 mm tebal material 8 mm adalah rata-rata 443,747 N/mm2, diameter elektroda 3,2 mm tebal material 10 mm adalah rata-rata 435,187 N/mm2, diameter elektroda 4 mm tebal material 8 mm adalah rata-rata 447,23 N/mm2, dan diameter elektroda 4 mm tebal material 10 mm adalah rata-rata 447,07 N/mm2. Hasil penelitian, modulus elastisitas dan tegangan luluh sama-sama memiliki kenaikan nilai, serta nilai pada regangan menurun. Sedangkan hasil pengujian impak didapatkan energi impak dari diameter elektroda 3,2 mm tebal material 8 mm adalah rata-rata 90,67 Joule, diameter elektroda 3,2 mm tebal material 10 mm adalah rata-rata 295,9 Joule, diameter elektroda 4 mm tebal material 8 mm adalah rata-rata 44,91 Joule, dan diameter elektroda 4 mm tebal material 10 mm adalah rata-rata 273,83 Joule.

  19. Measurement of solar diameter at zero almucantarat. (Italian Title: Misura del diametro solare ad almucantarat zero)

    Science.gov (United States)

    Sigismondi, C.

    2012-12-01

    Among several methods for accurate measurements of solar diameter, there are transits at fixed almucantarat used in solar astrolabes. The almucantarat is a circle of given height. The horizon circle is the zero almucantarat, and data from four sunsets on the Tyrrenian sea are discussed. The angular diameter of the Sun is recovered with a few arcseconds accuracy using 60 fps video of sunsets.

  20. Precise measurement of inner diameter of mono-capillary optic using X-ray imaging technique.

    Science.gov (United States)

    Kwon, Soonmu; Lim, Jae Hong; Namba, Yoshiharu; Chon, Kwon Su

    2017-11-16

    Mono-capillary optics have been applied to increase the performance of X-ray instruments. However, performance of a mono-capillary optic strongly depends on the shape accuracy, which is determined by the diameters of the inner hollow of the capillary along the axial direction. To precisely determine the inner diameter of the capillary optic used in X-ray imaging technique, which aims to replace the conventional method using a visible microscope. High spatial resolution X-ray images of the mono-capillary optic were obtained by a synchrotron radiation beamline. The inner diameter of the mono-capillary optic was measured and analyzed by the pixel values of the X-ray image. Edge enhancement effect was quite useful in determining the inner diameter, and the accuracy of the diameter determination was less than 1.32 μm. Many images obtained by scanning the mono-capillary optic along the axial direction were combined, and the axial profile, consisting of diameters along the axial direction, was obtained from the combined image. The X-ray imaging method could provide an accurate measurement with slope error of±19 μrad. Applying X-ray imaging technique to determine the inner diameter of a mono-capillary optic can contribute to increasing fabrication accuracy of the mono-capillary optic through a feedback process between the fabrication and measurement of its diameter.

  1. The diameters of long positive streamers in atmospheric air under lightning impulse voltage

    Science.gov (United States)

    Chen, She; Zeng, Rong; Zhuang, Chijie

    2013-09-01

    Results from experiments on long positive streamers in atmospheric air under lightning impulse voltage are presented. The length of the rod-plane gap is 57 cm. The peak voltages applied to the gap are +210-290 kV. The voltage and current are measured through a synchronized measurement system. The streamer diameters are obtained by the analysis of photographs taken by an intensified CCD (ICCD) camera. The four continuous photographs of single streamer discharge allow us to investigate the variation of the streamer diameters with time. For the hemispherical electrode 2 cm in diameter the diameters vary in the range 1.6-6.3 mm when the streamer length is 2-16 cm. The streamers are thicker when the electrode diameter is doubled from 2 to 4 cm. There is a downward trend in the streamer diameter with the propagation of the streamer heads. Their diameters for higher voltage decline at a lower rate. A modified analytical model is also employed to explain the observations. The streamer head potential and the maximum electric field are analysed for long streamers of tens of centimetres. The model can predict the value of the streamer diameter for different streamer head positions during its propagation. The experimental data and the calculated results are in good agreement.

  2. Diameter Distributions of Longleaf Pine Plantations-A Neural Network Approach

    Science.gov (United States)

    Daniel J. Leduc; Thomas G. Matney; V. Clark Baldwin

    1999-01-01

    The distribution of trees into diameter classes in longleaf pine (Pinus palustris Mill.) plantations does not tend to produce the smooth distributions common to other southern pines. While these distributions are sometimes unimodal, they are frequently bi- or even tri-modal and for this reason may not be easily modeled with traditional diameter...

  3. Updating Indiana Annual Forest Inventory and Analysis Plot Data Using Eastern Broadleaf Forest Diameter Growth Models

    Science.gov (United States)

    Veronica C. Lessard

    2001-01-01

    The Forest Inventory and Analysis (FIA) program of the North Central Research Station (NCRS), USDA Forest Service, has developed nonlinear, individual-tree, distance-independent annual diameter growth models. The models are calibrated for species groups and formulated as the product of an average diameter growth component and a modifier component. The regional models...

  4. Sample preparation and scanning protocol for computerised analysis of root length and diameter

    NARCIS (Netherlands)

    Bouma, T.J.; Nielsen, K.F.; Koutstaal, B.P.

    2000-01-01

    Root length and diameter distribution are important characteristics to be considered when describing and comparing root systems. Root length and root-diameter distribution may be obtained in two ways: by microscopical measurements, which are laborious, or by computerised analysis, which is fast but

  5. Phospholipid electrospun nanofibers: effect of solvents and co-axial processing on morphology and fiber diameter

    DEFF Research Database (Denmark)

    Jørgensen, Lars; Qvortrup, Klaus; Chronakis, Ioannis S.

    2015-01-01

    chloroform : dimethylformamide (CHCl3 : DMF, 3 : 2 v/v), isooctane, cyclohexane and limonene, producing phospholipid fibers with average diameters in the range of 2.57 +/- 0.59 mu m, similar to 3-8 mu m, similar to 4-5 mu m and 14.3 +/- 2.7 mu m, respectively. The diameter of asolectin electrospun fibers...

  6. Carotid flow velocity/diameter ratio is a predictor of cardiovascular events in hypertensive patients

    DEFF Research Database (Denmark)

    Bellinazzi, Vera R; Cipolli, José A; Pimenta, Marcio V

    2015-01-01

    OBJECTIVE: The aim of this study was to evaluate the performance of common carotid artery diameter, flow velocity and flow velocity/artery diameter ratio as predictors of major adverse cardiovascular events (MACEs) in a sample of hypertensive patients. METHODS: A cohort of 403 hypertensive patien...

  7. Photoelectrochemical water splitting properties of hydrothermally-grown ZnO nanorods with controlled diameters

    Science.gov (United States)

    Babu, Eadi Sunil; Hong, Soon-Ku; Vo, Thanh Son; Jeong, Jong-Ryul; Cho, Hyung Koun

    2015-01-01

    The effect of diameter change on photoelectrochemical water splitting was investigated in depth for ZnO nanorods. ZnO nanorods were grown on SiO2/Si and indium tin-oxide substrates by the hydrothermal growth method. By controlling the concentration ratio between zinc nitrate hexahydrate (ZNT) and hexamethylenetetramine (HMTA) nanorod diameters were changed from 45 to 275 nm, in which the diameter decreased with decreasing the ratio. Photoelectrochemical properties of ZnO nanorods with diameters from 45 to 255 nm were investigated under ultraviolet (UV) and visible light illumination. The maximum photoconversion efficiency of 45.3% was obtained from ZnO nanorods with 45 nm diameter under 365 nm UV light illumination. The photoconversion efficiency of 0.42% was obtained under Air Mass 1.5 Global simulated solar light illumination. Higher photoconversion efficiency for smaller diameter nanorods is attributed to the increase in the light absorption with decreasing the diameter that is confirmed by our simulation using finite-difference time domain. The length change of nanorods showed relatively negligible effects compared to the diameter change in our system.

  8. The impact of exercise training on the diameter dilator response to forearm ischaemia in healthy men

    NARCIS (Netherlands)

    Thijssen, D.H.J.; Tinken, T.M.; Hopkins, N.; Dawson, E.A.; Cable, N.T.; Green, D.J.

    2011-01-01

    AIM: Recent studies found differences between groups in the rate of diameter increase following the flow-mediated dilation (FMD). Whilst exercise training alters the magnitude of the FMD, little is known about the impact of exercise training on the rate of diameter increase. The aim of this study is

  9. Automated Nanofiber Diameter Measurement in SEM Images Using a Robust Image Analysis Method

    Directory of Open Access Journals (Sweden)

    Ertan Öznergiz

    2014-01-01

    Full Text Available Due to the high surface area, porosity, and rigidity, applications of nanofibers and nanosurfaces have developed in recent years. Nanofibers and nanosurfaces are typically produced by electrospinning method. In the production process, determination of average fiber diameter is crucial for quality assessment. Average fiber diameter is determined by manually measuring the diameters of randomly selected fibers on scanning electron microscopy (SEM images. However, as the number of the images increases, manual fiber diameter determination becomes a tedious and time consuming task as well as being sensitive to human errors. Therefore, an automated fiber diameter measurement system is desired. In the literature, this task is achieved by using image analysis algorithms. Typically, these methods first isolate each fiber in the image and measure the diameter of each isolated fiber. Fiber isolation is an error-prone process. In this study, automated calculation of nanofiber diameter is achieved without fiber isolation using image processing and analysis algorithms. Performance of the proposed method was tested on real data. The effectiveness of the proposed method is shown by comparing automatically and manually measured nanofiber diameter values.

  10. Production and cost of harvesting, processing, and transporting small-diameter (energy

    Science.gov (United States)

    Fei Pan; Han-Sup Han; Leonard R. Johnson; William J. Elliot

    2008-01-01

    Dense, small-diameter stands generally require thinning from below to improve fire-tolerance. The resulting forest biomass can be used for energy production. The cost of harvesting, processing, and transporting small-diameter trees often exceeds revenues due to high costs associated with harvesting and transportation and low market values for forest biomass....

  11. A computational algorithm addressing how vessel length might depend on vessel diameter

    Science.gov (United States)

    Jing Cai; Shuoxin Zhang; Melvin T. Tyree

    2010-01-01

    The objective of this method paper was to examine a computational algorithm that may reveal how vessel length might depend on vessel diameter within any given stem or species. The computational method requires the assumption that vessels remain approximately constant in diameter over their entire length. When this method is applied to three species or hybrids in the...

  12. Subarachnoid space diameter in chromosomally abnormal fetuses at 11-13 weeks' gestation.

    Science.gov (United States)

    Ferreira, Carolina; Rouxinol-Dias, Ana Lidia; Loureiro, Teresa; Nicolaides, Kypros

    2018-01-16

    To examine the subarachnoid space diameters in chromosomally abnormal fetuses at 11-13 weeks' gestation. Stored three-dimensional (3D) ultrasound volumes of the fetal head at 11-13 weeks' gestation from 407 euploid and 88 chromosomally abnormal fetuses (trisomy 21, n = 40; trisomy 18, n = 19; trisomy 13, n = 7; triploidy, n = 14; Turner syndrome, n = 8) were analyzed. The subarachnoid space diameters, measured in the sagittal and transverse planes of the fetal head, in relation to biparietal diameter (BPD) in each group of aneuploidies was compared to that in euploid fetuses. A total of 20 head volumes were randomly selected and all the measurements were recorded by two different observers to examine the interobserver variability in measurements. In euploid fetuses, the anteroposterior, transverse and sagittal diameters of the subarachnoid space increased with BPD. The median of the observed to expected diameters for BPD were significantly increased in triploidy and trisomy 13 but were not significantly altered in trisomies 21 and 18 or Turner syndrome. In triploidy, the subarachnoid space diameters for BPD were above the 95th centile of euploid fetuses in 92.9% (13 of 14) cases. The intraclass reliability or agreement was excellent for all three subarachnoid space diameters. Most fetuses with triploidy at 11-13 weeks' gestation demonstrate increased subarachnoid space diameters.

  13. Is there a Relationship between the Diameter of the Inferior Vena ...

    African Journals Online (AJOL)

    The relationship between the diameters of IVC and CVP was evaluated and significant correlation was found in IAP, EAP according to CVP values (p<0.001). ROC analyses were ... Conclusion: Measurement of IVC diameters, especially EAP may be useful at the monitoring of critically ill patients in ED. Keywords: Central ...

  14. A Numerical Simulation of Base Shear Forces and Moments Exerted by Waves on Large Diameter Pile

    Directory of Open Access Journals (Sweden)

    You-liang Cheng

    2017-01-01

    Full Text Available To solve the problem of the dynamic variation of wave force diameter of pile foundation for offshore wind turbines, wave force and moment of large diameter pile foundation can be calculated. In this paper, simulation technique is used to calculate the wave force and moment of different large diameter pile foundation, and the base shear force and moment of the interval 20-degree phase angle are obtained by the base line of the pile. Under the action of a certain load, the complete stress variation of the pile foundation is obtained. According to the basic principle of diffraction theory, the process curve of large diameter pile, and analysis of wave force, diffraction force changes in a certain period of time interval. The results show that the wave after the large diameter pile formed around the vortex, large diameter pile base shear, and moment dynamic change is nonlinear in a complete cycle, the diameter of the pile increases by 0.5 m, and the wave force increases by about 5%, the results show that it provides certain reference value for the offshore pile foundation pile with large diameter primary site. Some significant results for practical application are discussed.

  15. Board-Foot and Diameter Growth of Yellow-Poplar After Thinning

    Science.gov (United States)

    Donald E. Beck; Lino Della-Bianca

    1975-01-01

    Board-foot growth and yield of thinned yellow-poplar stands (Liriodendron tulipifera L.)is related to age, site index, residual basal area, and residual quadratic mean stand diameter after thinning. Diameter growth of individual trees is increased considerably by thinning. Equations describing growth and yield are based on data from 141 natura1 yellow-poplar stands in...

  16. 77 FR 47596 - Small Diameter Graphite Electrodes From the People's Republic of China: Affirmative Final...

    Science.gov (United States)

    2012-08-09

    ... International Trade Administration Small Diameter Graphite Electrodes From the People's Republic of China... Department'') continues to determine that certain small diameter graphite electrodes (``SDGE'') are being exported from the United Kingdom (``U.K.'') to the United States by UK Carbon and Graphite Co., Ltd...

  17. 78 FR 56864 - Small Diameter Graphite Electrodes From the People's Republic of China: Affirmative Final...

    Science.gov (United States)

    2013-09-16

    ... International Trade Administration Small Diameter Graphite Electrodes From the People's Republic of China... from the People's Republic of China (PRC) of graphite electrodes, produced and/or exported by Sinosteel...\\ \\1\\ See Antidumping Duty Order: Small Diameter Graphite Electrodes From the People's Republic of...

  18. The effect of nanowire length and diameter on the properties of transparent, conducting nanowire films

    Science.gov (United States)

    Bergin, Stephen M.; Chen, Yu-Hui; Rathmell, Aaron R.; Charbonneau, Patrick; Li, Zhi-Yuan; Wiley, Benjamin J.

    2012-03-01

    This article describes how the dimensions of nanowires affect the transmittance and sheet resistance of a random nanowire network. Silver nanowires with independently controlled lengths and diameters were synthesized with a gram-scale polyol synthesis by controlling the reaction temperature and time. Characterization of films composed of nanowires of different lengths but the same diameter enabled the quantification of the effect of length on the conductance and transmittance of silver nanowire films. Finite-difference time-domain calculations were used to determine the effect of nanowire diameter, overlap, and hole size on the transmittance of a nanowire network. For individual nanowires with diameters greater than 50 nm, increasing diameter increases the electrical conductance to optical extinction ratio, but the opposite is true for nanowires with diameters less than this size. Calculations and experimental data show that for a random network of nanowires, decreasing nanowire diameter increases the number density of nanowires at a given transmittance, leading to improved connectivity and conductivity at high transmittance (>90%). This information will facilitate the design of transparent, conducting nanowire films for flexible displays, organic light emitting diodes and thin-film solar cells.This article describes how the dimensions of nanowires affect the transmittance and sheet resistance of a random nanowire network. Silver nanowires with independently controlled lengths and diameters were synthesized with a gram-scale polyol synthesis by controlling the reaction temperature and time. Characterization of films composed of nanowires of different lengths but the same diameter enabled the quantification of the effect of length on the conductance and transmittance of silver nanowire films. Finite-difference time-domain calculations were used to determine the effect of nanowire diameter, overlap, and hole size on the transmittance of a nanowire network. For

  19. Special Aspects of the Roller Screws Pieces Male Thread Pitch Diameters Control

    Directory of Open Access Journals (Sweden)

    D. S. Blinov

    2014-01-01

    Full Text Available It is established that at the present moment the roller screws (RS are the most challenging mechanical transducers of rotational motion into forward motion. For that reason their field of application is being constantly enlarged. In the West one can observe the tendency of the replacement of hydraulic drive by RS-based electromechanical drive. The main RS parts are screw, thread rollers and female screw which on the load transmission interact in the contact lands located on the pitch diameters of the special thread of these parts. To exclude the edge contacts on the male screw and female screw the thread with triangular profile waps are performed, on the rollers – with convex profile. Besides the pitch diameters of the male screw, rollers and female screw thread form the closed-loop dimension chain, and the values of these diameters affect the RS axial play and its performance capabilities significantly. Therefrom in manufacturing thread pieces it is required to carry out the high-precision control of their thread pitch diameters. For the male thread this control is carried out by means of three cylindrical wires with preferred diameter. Such wires are available at the factories of the Russian Federation and are represented in AllUnion State Standard 2475-88 for the standard thread (metric, trapeziform and others, and they are not available for the RS pieces special thread. It was proposed for the RS pieces male thread pitch diameter control to use the standard wires, the diameter of which is the next larger to the necessary preferred diameter of the RS piece controlled thread. The article presents the preferred diameters of the wires for the RS thread pieces control with employed pitch of the special thread. The dependencies for sizing up of the RS pieces male screw and roller pitch diameter dimension control is deduced by utilizing the wires of unspecified diameter, including preferred diameter. In view of the RS potential it is required to

  20. Transabdominal ultrasound measurement of rectal diameter is dependent on time to defecation in constipated children

    DEFF Research Database (Denmark)

    Modin, Line; Dalby, Kasper; Walsted, Anne-Mette

    2015-01-01

    AIM: To study whether diurnal variations and time in relation to defecation has to be taken into account when measurements of rectal diameter are used to determine faecal impaction in constipated children. METHODS: Repeated ultrasound measures of rectal diameter were performed in 28 children (14...... at 2 pm (P = 0.038) and 5 pm (P = 0.006). There were significant differences between rectal diameter in the healthy group and the constipated group at 2 pm (P = 0.016) and 5 pm (P = 0.027). When we omitted the rectal diameter of five constipated children who had their first bowel movement after 5 pm....... There was a relation between defecation and changes in rectal diameter in both healthy children and constipated children during maintenance treatment.Asking for defecation signals before scanning should be considered a routine question, and a positive answer should cause postponement of the scan....

  1. Disagreement of diameter and volume measurements for pulmonary nodule size estimation in CT lung cancer screening.

    Science.gov (United States)

    Heuvelmans, Marjolein A; Walter, Joan E; Vliegenthart, Rozemarijn; van Ooijen, Peter M A; De Bock, Geertruida H; de Koning, Harry J; Oudkerk, Matthijs

    2017-10-22

    We studied 2240 indeterminate solid nodules (volume 50-500mm3) to determine the correlation of diameter and semi-automated volume measurements for pulmonary nodule size estimation. Intra-nodular diameter variation, defined as maximum minus minimum diameter through the nodule's center, varied by 2.8 mm (median, IQR:2.2-3.7 mm), so above the 1.5 mm cutoff for nodule growth used in Lung CT Screening Reporting and Data System (Lung-RADS). Using mean or maximum axial diameter to assess nodule volume led to a substantial mean overestimation of nodule volume of 47.2% and 85.1%, respectively, compared to semi-automated volume. Thus, size of indeterminate nodules is poorly represented by diameter. Pre-results, ISRCTN63545820. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  2. The Effect of Surfactants on the Diameter and Morphology of Electrospun Ultrafine Nanofiber

    Directory of Open Access Journals (Sweden)

    Jian-Yi Zheng

    2014-01-01

    Full Text Available Different surfactants are introduced to study the diameter and morphology transformation characteristics of electrospun nanofiber. Surfactants increase the net charge density and instability motion of charged jet. The instability motion provides a good way to stretch the charged jets into finer ones, by which the beaded structures are also prevented. Ultrafine nanofiber with average diameter less than 65 nm can be fabricated. The nanofiber diameter decreases with the increase of surfactant concentration in polymer solution. The nanofibers with anionic surfactant sodium dodecyl sulfate (SDS have the smallest diameter. The cationic surfactant hexadecyl trimethyl ammonium bromide (HTAB plays the best role to prevent the formation of beaded structures in nanofibers, and helps to increase the uniformity of electrospun nanofiber. The effects of surfactants on the nanofiber diameter and morphology have been studied, which would promote the industrial application of ultrafine polymeric nanofibers.

  3. Observation of Ureteric Diameter in Negative Intravenous Urogram in Hospital Universiti Kebangsaan Malaysia

    Science.gov (United States)

    Wong, Siong Lung; Abdul Hamid, Hamzaini

    2010-01-01

    Background: This study observed the widest ureteric diameter in negative intravenous urogram (IVU) examinations using low osmolar contrast media. Methods: We reviewed a total of one hundred and eighty four ureters from 92 negative IVUs. Results: The results show a mean diameter for the abdominal ureter of 4.19 mm with an SD of 1.27 mm and a mean pelvic ureteric diameter of 4.45 mm with an SD of 1.37 mm. The upper limits for abdominal ureter and pelvic ureter based on a confidence interval of 95% were 4.37 mm and 4.64 mm, respectively. Conclusions: There was no significant difference between the right and left ureteric diameter in both female and male subjects. There was no significant correlation between ureteric diameters and the age of subjects, from the second to the eighth decades. PMID:22135531

  4. Screening for hemoglobin Bart’s disease among fetuses at risk at mid-pregnancy using the fetal cardiac diameter to biparietal diameter ratio

    OpenAIRE

    Thathan, Nopamas; Traisrisilp, Kuntharee; Luewan, Suchaya; Srisupundit, Kasemsri; Tongprasert, Fuanglada; Tongsong, Theera

    2014-01-01

    Background All sonomarkers used to screen for fetal hemoglobin (Hb) Bart’s disease need high expertise, preventing them from being widely used. Fetal cardiac diameter to biparietal diameter (C/B) ratio is a simple marker which has never been evaluated for its effectiveness. Therefore, we conducted this study to evaluate the effectiveness of C/B ratio in predicting fetal Hb Bart’s disease among fetuses at risk. Methods Fetuses at risk of Hb Bart’s disease scheduled for diagnostic cordocentesis...

  5. Impact of vent pipe diameter on characteristics of waste degradation in semi-aerobic bioreactor landfill.

    Science.gov (United States)

    Jiang, Guobin; Liu, Dan; Chen, Weiming; Ye, Zhicheng; Liu, Hong; Li, Qibin

    2017-10-01

    The evolution mechanism of a vent pipe diameter on a waste-stabilization process in semi-aerobic bioreactor landfills was analyzed from the organic-matter concentration, biodegradability, spectral characteristics of dissolved organic matter, correlations and principal-component analysis. Waste samples were collected at different distances from the vent pipe and from different landfill layers in semi-aerobic bioreactor landfills with different vent pipe diameters. An increase in vent pipe diameter favored waste degradation. Waste degradation in landfills can be promoted slightly when the vent pipe diameter increases from 25 to 50 mm. It could be promoted significantly when the vent pipe diameter was increased to 75 mm. The vent pipe diameter is important in waste degradation in the middle layer of landfills. The dissolved organic matter in the waste is composed mainly of long-wave humus (humin), short-wave humus (fulvic acid) and tryptophan. The humification levels of the waste that was located at the center of vent pipes with 25-, 50- and 75-mm diameters were 2.2682, 4.0520 and 7.6419 Raman units, respectively. The appropriate vent pipe diameter for semi-aerobic bioreactor landfills with an 800-mm diameter was 75 mm. The effect of different vent pipe diameters on the degree of waste stabilization is reflected by two main components. Component 1 is related mainly to the content of fulvic acid, biologically degradable material and organic matter. Component 2 is related mainly to the content of tryptophan and humin from the higher vascular plants.

  6. Optic Nerve Sheath Diameter Increase on Ascent to High Altitude: Correlation With Acute Mountain Sickness.

    Science.gov (United States)

    Kanaan, Nicholas C; Lipman, Grant S; Constance, Benjamin B; Holck, Peter S; Preuss, James F; Williams, Sarah R

    2015-09-01

    Elevated optic nerve sheath diameter on sonography is known to correlate with increased intracranial pressure and is observed in acute mountain sickness. This study aimed to determine whether optic nerve sheath diameter changes on ascent to high altitude are associated with acute mountain sickness incidence. Eighty-six healthy adults enrolled at 1240 m (4100 ft), drove to 3545 m (11,700 ft) and then hiked to and slept at 3810 m (12,500 ft). Lake Louise Questionnaire scores and optic nerve sheath diameter measurements were taken before, the evening of, and the morning after ascent. The incidence of acute mountain sickness was 55.8%, with a mean Lake Louise Questionnaire score ± SD of 3.81 ± 2.5. The mean maximum optic nerve sheath diameter increased on ascent from 5.58 ± 0.79 to 6.13 ± 0.73 mm, a difference of 0.91 ± 0.55 mm (P = .09). Optic nerve sheath diameter increased at high altitude regardless of acute mountain sickness diagnosis; however, compared to baseline values, we observed a significant increase in diameter only in those with a diagnosis of acute mountain sickness (0.57 ± 0.77 versus 0.21 ± 0.76 mm; P = .04). This change from baseline, or Δ optic nerve sheath diameter, was associated with twice the odds of developing acute mountain sickness (95% confidence interval, 1.08-3.93). The mean optic nerve sheath diameter increased on ascent to high altitude compared to baseline values, but not to a statistically significant degree. The magnitude of the observed Δ optic nerve sheath diameter was positively associated with acute mountain sickness diagnosis. No such significant association was found between acute mountain sickness and diameter elevation above standard cutoff values, limiting the utility of sonography as a diagnostic tool. © 2015 by the American Institute of Ultrasound in Medicine.

  7. Brachial artery diameter as a marker for cardiovascular risk assessment: FMD-J study.

    Science.gov (United States)

    Maruhashi, Tatsuya; Soga, Junko; Fujimura, Noritaka; Idei, Naomi; Mikami, Shinsuke; Iwamoto, Yumiko; Iwamoto, Akimichi; Kajikawa, Masato; Matsumoto, Takeshi; Oda, Nozomu; Kishimoto, Shinji; Matsui, Shogo; Hashimoto, Haruki; Aibara, Yoshiki; Yusoff, Farina Mohamad; Hidaka, Takayuki; Kihara, Yasuki; Chayama, Kazuaki; Noma, Kensuke; Nakashima, Ayumu; Goto, Chikara; Tomiyama, Hirofumi; Takase, Bonpei; Kohro, Takahide; Suzuki, Toru; Ishizu, Tomoko; Ueda, Shinichiro; Yamazaki, Tsutomu; Furumoto, Tomoo; Kario, Kazuomi; Inoue, Teruo; Koba, Shinji; Watanabe, Kentaro; Takemoto, Yasuhiko; Hano, Takuzo; Sata, Masataka; Ishibashi, Yutaka; Node, Koichi; Maemura, Koji; Ohya, Yusuke; Furukawa, Taiji; Ito, Hiroshi; Ikeda, Hisao; Yamashina, Akira; Higashi, Yukihito

    2018-01-01

    Baseline brachial artery (BBA) diameter has been reported to be a potential confounding factor of flow-mediated vasodilation (FMD). The purpose of this study was to evaluate the relationships between BBA diameter and cardiovascular risk factors and compare the diagnostic accuracy of BBA diameter in subjects without cardiovascular risk factors and patients with cardiovascular disease (CVD) with that of FMD. We measured BBA diameter and FMD in 5695 male subjects. In addition, we retrospectively investigated the incidence of cardiovascular events using another population sample consisting of 440 male subjects, to compare the accuracy of BBA diameter with that of FMD in predicting cardiovascular events. BBA diameter and FMD significantly correlated with age, body mass index, systolic blood pressure, diastolic blood pressure, triglycerides, high-density lipoprotein cholesterol, and glucose as well as Framingham risk score. The prevalence of cardiovascular risk factors and CVD increased with the increase in BBA diameter and FMD. Area under the curve (AUC) value of the receiver operating characteristic (ROC) curve for BBA diameter to diagnose subjects without cardiovascular risk factors (0.59 vs. 0.62, p = 0.001) or patients with CVD (0.58 vs. 0.64, p FMD. In the retrospective study, the AUC value of the ROC curve for BBA diameter to predict first major cardiovascular events was significantly lower than that of FMD (0.50 vs. 0.62, p = 0.03). In men, BBA diameter was inferior to FMD for assessment of cardiovascular risk. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Inventory-based sensitivity analysis of the Large Tree Diameter Growth Submodel of the Southern Variant of the FVS

    Science.gov (United States)

    Giorgio Vacchiano; John D. Shaw; R. Justin DeRose; James N. Long

    2008-01-01

    Diameter increment is an important variable in modeling tree growth. Most facets of predicted tree development are dependent in part on diameter or diameter increment, the most commonly measured stand variable. The behavior of the Forest Vegetation Simulator (FVS) largely relies on the performance of the diameter increment model and the subsequent use of predicted dbh...

  9. The impact of exercise training on the diameter dilator response to forearm ischaemia in healthy men.

    Science.gov (United States)

    Thijssen, D H J; Tinken, T M; Hopkins, N; Dawson, E A; Cable, N T; Green, D J

    2011-04-01

    Recent studies found differences between groups in the rate of diameter increase following the flow-mediated dilation (FMD). Whilst exercise training alters the magnitude of the FMD, little is known about the impact of exercise training on the rate of diameter increase. The aim of this study is to examine post-cuff deflation changes in brachial artery diameter following 5 min forearm ischaemia every 2 weeks across 8-weeks of a handgrip exercise training regimen. Post-deflation changes in brachial artery diameter following 5-min of ischaemia were examined before, after and every 2-weeks across an 8-week handgrip training programme in healthy young men (n = 11) using echo-Doppler. The magnitude of dilation increased at week 2-4-6, but returned towards baseline values at week 8 (anova: P = 8.001). The time-to-peak diameter (42 ± 15s) demonstrated a significant prolongation at week 4 (77 ± 32s), but returned towards baseline values at weeks 6 and 8 (anova: P < 0.001). The rate of diameter increase did not differ across the intervention. Exercise training in healthy subjects is initially characterized by a larger dilation. Since the rate of dilation did not change, a longer time-to-peak dilation was necessary to achieve the increase in magnitude of dilation. As exercise training continues, the timing and magnitude of the peak diameter response returns to near baseline levels.

  10. The effect of nozzle diameter, injection pressure and ambient temperature on spray characteristics in diesel engine

    Science.gov (United States)

    Rhaodah Andsaler, Adiba; Khalid, Amir; Sharifhatul Adila Abdullah, Nor; Sapit, Azwan; Jaat, Norrizam

    2017-04-01

    Mixture formation of the ignition process is a key element in the diesel combustion as it influences the combustion process and exhaust emission. Aim of this study is to elucidate the effects of nozzle diameter, injection pressure and ambient temperature to the formation of spray. This study investigated diesel formation spray using Computational Fluid Dynamics. Multiphase volume of fluid (VOF) behaviour in the chamber are determined by means of transient simulation, Eulerian of two phases is used for implementation of mixing fuel and air. The detail behaviour of spray droplet diameter, spray penetration and spray breakup length was visualised using the ANSYS 16.1. This simulation was done in different nozzle diameter 0.12 mm and 0.2 mm performed at the ambient temperature 500 K and 700 K with different injection pressure 40 MPa, 70 MPa and 140 MPa. Results show that high pressure influence droplet diameter become smaller and the penetration length longer with the high injection pressure apply. Smaller nozzle diameter gives a shorter length of the breakup. It is necessary for nozzle diameter and ambient temperature condition to improve the formation of spray. High injection pressure is most effective in improvement of formation spray under higher ambient temperature and smaller nozzle diameter.

  11. Chest diameter ratios for detecting static hyperinflation in children using photogrammetry.

    Science.gov (United States)

    Ricieri, Denise da V; Rosário, Nelson A; Costa, Jecilene R

    2008-01-01

    To develop a photogrammetric method capable of identifying increases in anteroposterior chest diameters suggestive of pulmonary hyperinflation, and to test it with both asthmatic and asthma-free children. Two distinct study designs were used to achieve these two objectives. The first was a descriptive analysis of diameters measured at the height of the axilla and of the xiphoid on digital images of 56 children aged 8 to 12 years photographed in the orthostatic position. The second was a case-control study of (a) 19 asthmatic children in treatment for at least 12 months; and (b) 37 children free from asthma with no prior history of complaints of respiratory/allergic disease. Diameters were measured on images of the front and left side views using CorelDRAW, and the ratio between the front and side diameters was calculated for the axillary and xiphoid measurements, providing the diameter ratios. Diameter ratios close to or greater than 1 represent geometry tending towards a cylindrical shape, typical of hyperinflation on radiographs. Analysis with the t test for independent samples revealed a mean diameter ratio at the sternum that was significantly greater in the group of asthmatic children (p photogrammetry is a promising tool for the identification of a kinesiopathological manifestation that is known to determine air entrapment in asthma patients. Research that combines clinical data with longitudinal intrapatient follow-up will be necessary to establish the strength of the evidence found in this study.

  12. Chest anteroposterior diameter affects difficulty of laryngoscopy for non-morbidly obese patients.

    Science.gov (United States)

    Choi, Ji-Won; Kim, Jie-Ae; Kim, Hae-Kyoung; Oh, Min-Seok; Kim, Duk-Kyung

    2013-08-01

    This prospective, observational study was performed to examine the hypothesis that if conventional 7-cm head elevation is applied, laryngoscopy is more difficult for patients with anteroposterior chest diameter (chest AP diameter) outside the average range (≥17.7 or ≤14.7 cm). Chest AP diameter at the sternal notch were measured preoperatively. All patients were placed on a surgical bed with an incompressible 7-cm pillow. During laryngoscopy, the laryngeal view was graded by use of the Cormack-Lehane classification. Difficult visualization of the larynx (DVL) was defined as a grade 3 or 4 view. DVL was observed for 49 patients (18.2 %). Differences between measured chest AP diameter for each patient and the calculated median value were used for statistical analysis. In univariate analysis, the difference between chest AP diameter and the median value was significantly related to DVL. Logistic regression analysis confirmed that the difference between chest AP diameter and the median value was an independent predictor of DVL (odds ratio, 3.900; 95 % confidence interval, 2.371-6.415; p pillow size of 7 cm, chest AP diameter above or below the average range (≥17.7 or ≤14.7 cm) was a strong predictor of DVL for apparently normal-sized patients. In such cases, modification of pillow height should be considered.

  13. Endovascular radiofrequency ablation. Effect on the vein diameter using the ClosureFast(®) catheter.

    Science.gov (United States)

    Bauzá Moreno, Hernán; Dotta, Mariana; Katsini, Roxana; Marquez Fosser, Carolina; Rochet, Sofía; Pared, Carlos; Martinez, Hugo

    2016-01-01

    Endovascular radiofrequency with first generation catheters was not successful due to its technical difficulty and restrictions in veins with diameters larger than 12mm. However, using the new catheter there is not enough scientific evidence to affirm that the diameter represents a technical limitation. The aim of this study was to evaluate and compare pre and post-operative venous trunks diameter, aiming at the reduction of size after 6 months with last generation catheters. Retrospective observational and descriptive study on a cohort of patients with insufficiency of the great saphenous vein, small saphenous vein and anterior accessory vein operated on with last generation radiofrequency catheters. The diameters were evaluated in the pre and post-operative period with ultrasound. Between 2007 and 2014 a total of 365 ablations were performed in veins with an average diameter of 9±3.1mm showing a reduction of it after 6 months with a mean value of 5.2±0.8mm (P<.0001). Total occlusion was also observed in 100% of cases and complications such as deep vein thrombosis in 0.5% and heat-induced thrombosis in 1.1%. A significant reduction in venous diameter after endovascular treatment with the new ClosureFast(®) catheters was checked, even in veins with diameters greater than 12mm. Copyright © 2016 AEC. Publicado por Elsevier España, S.L.U. All rights reserved.

  14. Evaluation of normal abdominal aortic diameters in the Indian population using computed tomography.

    Science.gov (United States)

    Jasper, A; Harshe, G; Keshava, S N; Kulkarni, G; Stephen, E; Agarwal, S

    2014-01-01

    The aim of this study was to establish normal diameters for the suprarenal and infrarenal abdominal aorta measured at T12 and L3 vertebral levels in the Indian population and to study the variation in aortic diameters with age, sex, height, weight, body mass index (BMI), and body surface area (BSA). One hundred and forty-two patients who underwent helical contrast-enhanced computed tomography (CT) scans of the abdomen for non-cardiovascular reasons were recruited.. The mean internal diameters of the suprarenal and infrarenal abdominal aorta (maximum anteroposterior and transverse diameter) were measured at T12 and L3 vertebral levels and tabulated according to various age groups for both men and women. Pearson correlation coefficient was used to evaluate the correlation between aortic diameters, height, weight, BSA, and BMI. The mean diameters of the suprarenal and infrarenal abdominal aorta measured at T12 and L3 vertebral levels, in men were 19.0 ± 2.3 and 13.8 ± 1.9 mm and in women 17.1 ± 2.3 and 12.0 ± 1.6 mm, respectively. The aortic diameter progressively increased in caliber with increasing age of the patients and was smaller in women than men. A significant positive correlation was found in men between the suprarenal and infrarenal aortic diameters and weight, BSA, and BMI. In women, this correlation was significant in the infrarenal aorta but not in the suprarenal aorta. We obtained a set of normal values for the abdominal aorta in the Indian population. The aortic diameters correlated with age, gender, and body size of the patients as seen with previously published data in the Western population. A brief comparison of data between Indian and Western population showed that the values obtained were less than published elsewhere and hence, this should be considered while formulating intervention protocols.

  15. Evaluation of normal abdominal aortic diameters in the Indian population using computed tomography

    Directory of Open Access Journals (Sweden)

    A Jasper

    2014-01-01

    Full Text Available Objectives: The aim of this study was to establish normal diameters for the suprarenal and infrarenal abdominal aorta measured at T12 and L3 vertebral levels in the Indian population and to study the variation in aortic diameters with age, sex, height, weight, body mass index (BMI, and body surface area (BSA. Materials and Methods: One hundred and forty-two patients who underwent helical contrast-enhanced computed tomography (CT scans of the abdomen for non-cardiovascular reasons were recruited.. The mean internal diameters of the suprarenal and infrarenal abdominal aorta (maximum anteroposterior and transverse diameter were measured at T12 and L3 vertebral levels and tabulated according to various age groups for both men and women. Pearson correlation coefficient was used to evaluate the correlation between aortic diameters, height, weight, BSA, and BMI. Results: The mean diameters of the suprarenal and infrarenal abdominal aorta measured at T12 and L3 vertebral levels, in men were 19.0 ± 2.3 and 13.8 ± 1.9 mm and in women 17.1 ± 2.3 and 12.0 ± 1.6 mm, respectively. The aortic diameter progressively increased in caliber with increasing age of the patients and was smaller in women than men. A significant positive correlation was found in men between the suprarenal and infrarenal aortic diameters and weight, BSA, and BMI. In women, this correlation was significant in the infrarenal aorta but not in the suprarenal aorta. Conclusion: We obtained a set of normal values for the abdominal aorta in the Indian population. The aortic diameters correlated with age, gender, and body size of the patients as seen with previously published data in the Western population. A brief comparison of data between Indian and Western population showed that the values obtained were less than published elsewhere and hence, this should be considered while formulating intervention protocols.

  16. Climate-diameter growth relationships of black spruce and jack pine trees in boreal Ontario, Canada.

    Science.gov (United States)

    Subedi, Nirmal; Sharma, Mahadev

    2013-02-01

    To predict the long-term effects of climate change - global warming and changes in precipitation - on the diameter (radial) growth of jack pine (Pinus banksiana Lamb.) and black spruce (Picea mariana [Mill.] B.S.P.) trees in boreal Ontario, we modified an existing diameter growth model to include climate variables. Diameter chronologies of 927 jack pine and 1173 black spruce trees, growing in the area from 47°N to 50°N and 80°W to 92°W, were used to develop diameter growth models in a nonlinear mixed-effects approach. Our results showed that the variables long-term average of mean growing season temperature, precipitation during wettest quarter, and total precipitation during growing season were significant (alpha = 0.05) in explaining variation in diameter growth of the sample trees. Model results indicated that higher temperatures during the growing season would increase the diameter growth of jack pine trees, but decrease that of black spruce trees. More precipitation during the wettest quarter would favor the diameter growth of both species. On the other hand, a wetter growing season, which may decrease radiation inputs, increase nutrient leaching, and reduce the decomposition rate, would reduce the diameter growth of both species. Moreover, our results indicated that future (2041-2070) diameter growth rate may differ from current (1971-2000) growth rates for both species, with conditions being more favorable for jack pine than black spruce trees. Expected future changes in the growth rate of boreal trees need to be considered in forest management decisions. We recommend that knowledge of climate-growth relationships, as represented by models, be combined with learning from adaptive management to reduce the risks and uncertainties associated with forest management decisions. © 2012 Blackwell Publishing Ltd.

  17. The impact of baseline diameter on flow-mediated dilation differs in young and older humans.

    Science.gov (United States)

    Thijssen, Dick H J; van Bemmel, Marieke M; Bullens, Lauren M; Dawson, Ellen A; Hopkins, Nicola D; Tinken, Toni M; Black, Mark A; Hopman, Maria T E; Cable, N Timothy; Green, Daniel J

    2008-10-01

    Flow-mediated dilation (FMD) has become a commonly applied approach for the assessment of vascular function and health, but methods used to calculate FMD differ between studies. For example, the baseline diameter used as a benchmark is sometimes assessed before cuff inflation, whereas others use the diameter during cuff inflation. Therefore, we compared the brachial artery diameter before and during cuff inflation and calculated the resulting FMD in healthy children (n=45; 10+/-1 yr), adults (n=31; 28+/-6 yr), and older subjects (n=22; 58+/-5 yr). Brachial artery FMD was examined after 5 min of distal ischemia. Diameter was determined from either 30 s before cuff inflation or from the last 30 s during cuff inflation. Edge detection and wall tracking of high resolution B-mode arterial ultrasound images was used to calculate conduit artery diameter. Brachial artery diameter during cuff inflation was significantly larger than before inflation in children (P=0.02) and adults (P<0.001) but not in older subjects (P=0.59). Accordingly, FMD values significantly differed in children (11.2+/-5.1% vs. 9.4+/-5.2%; P=0.02) and adults (7.3+/-3.2% vs. 4.6+/-3.3%; P<0.001) but not in older subjects (6.3+/-3.4% vs. 6.0+/-4.2%; P=0.77). When the diameter before cuff inflation was used, an age-dependent decline was evident in FMD, whereas FMD calculated using the diameter during inflation was associated with higher FMD values in older than younger adults. In summary, the inflation of the cuff significantly increases brachial artery diameter, which results in a lower FMD response. This effect was found to be age dependent, which emphasizes the importance of using appropriate methodology to calculate the FMD.

  18. Long periods in Solar diameter variations observed with the solar astrolabe

    Energy Technology Data Exchange (ETDEWEB)

    Laclare, F.

    1987-07-30

    A solar astrometry program, covers now 95 % of the activity cycle No. 21. The diameter measurements derived from these observations are of the same quality as the results obtained on the orbit elements or the equinox position. An analysis of the complete observational data reveals or confirms oscillations, some of which seem correlated with solar activity. Several long periods, from 50 to 1,000 days, have been detected, and a negative correlation between diameter measurements and the sunspot cycle seems to exist. The ongoing improvements in instrumental performances and the extension of measurements to a longer time span will contribute to a better definition of the long periods in solar diameter variations.

  19. 76 FR 12325 - Small Diameter Graphite Electrodes From the People's Republic of China: Preliminary Results of...

    Science.gov (United States)

    2011-03-07

    ... systems for small diameter graphite electrodes are most commonly used in primary melting, ladle metallurgy... Products Co., Ltd. 90 Xinyuan Carbon Co., Ltd. 91 Xuanhua Hongli Refractory and Mineral Company. 92 Xuchang...

  20. Evaluation of the Load-Displacement Relationships for Large-Diameter Piles in Sand

    DEFF Research Database (Denmark)

    Sørensen, Søren Peder Hyldal; Brodbaek, K. T.; Moller, M.

    2009-01-01

    For laterally loaded piles in sand with diameters up to 6 m, e.g. monopiles used as foundations for offshore wind turbines, there is no approved design procedure. The p-y curve method, given in offshore design regulations, is usually employed for the design of monopiles. However, this method...... was developed for slender piles with diameters much less than 6 m and it is based on a limited number of tests. The aim of the present work is to extend the p-y curve method to large-diameter non-slender piles by considering the effects of the pile diameter on the soil response. The main focus is the initial...

  1. Fatigue acceptance test limit criteria for larger diameter rolled thread fasteners

    Energy Technology Data Exchange (ETDEWEB)

    Kephart, A.R.

    1999-05-19

    This document describes a fatigue lifetime acceptance test criterion by which studs having rolled threads, larger than 1.0 inches (25 mm) in diameter, can be assured to meet minimum quality attributes associated with a controlled rolling process.

  2. SUB-KILOMETER ASTEROID DIAMETER SURVEY (SKADS) V1.0

    Data.gov (United States)

    National Aeronautics and Space Administration — The Sub-Kilometer Asteroid Diameter Survey (SKADS) (Gladman et al. 2009) acquired good-quality orbital and absolute magnitude (H) determinations for a sample of...

  3. Abdominal Aortic Diameter Is Increased in Males with a Family History of Abdominal Aortic Aneurysms

    DEFF Research Database (Denmark)

    Mejnert Jørgensen, Trine; Houlind, K; Green, A

    2014-01-01

    measurement of maximum antero-posterior aortic diameter. Family history obtained by questionnaire. Multivariate regression analysis was used to test for confounders: age, sex, smoking, comorbidity and medication. RESULTS: From the screened cohort, 569 participants had at least one first degree relative......OBJECTIVE: To investigate, at a population level, whether a family history of abdominal aortic aneurysm (AAA) is independently related to increased aortic diameter and prevalence of AAA in men, and to elucidate whether the mean aortic diameter and the prevalence of AAA are different between...... participants with male and female relatives with AAA. DESIGN: Observational population-based cross-sectional study. MATERIALS: 18,614 male participants screened for AAA in the VIVA-trial 2008-2011 with information on both family history of AAA and maximal aortic diameter. METHODS: Standardized ultrasound scan...

  4. Automatic diameter control system applied to the laser heated pedestal growth technique

    Directory of Open Access Journals (Sweden)

    Andreeta M.R.B.

    2003-01-01

    Full Text Available We described an automatic diameter control system (ADC, for the laser heated pedestal growth technique, that reduces the diameter fluctuations in oxide fibers grown from unreacted and non-sinterized pedestals, to less than 2% of the average fiber diameter, and diminishes the average diameter fluctuation, over the entire length of the fiber, to less than 1%. The ADC apparatus is based on an artificial vision system that controls the pulling speed and the height of the molten zone within a precision of 30 mum. We also show that this system can be used for periodic in situ axial doping the fiber. Pure and Cr3+ doped LaAlO3 and pure LiNbO3 were usedas model materials.

  5. LBA-ECO CD-08 Tree Diameter Measurements, Jacaranda Plots, Manaus, Brazil: 1999-2001

    Data.gov (United States)

    National Aeronautics and Space Administration — ABSTRACT: This data set provides diameter at breast height (DBH) measurements made of trees in a dense terra-firme tropical moist forest at the ZF-2 Experimental...

  6. LBA-ECO ND-02 Secondary Forest Tree Heights and Diameters, Para, Brazil: 1999-2005

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set provides tree diameters and heights measured from 1999 to 2005 in plots of a secondary-growth forest fertilization experiment located 6.5-km northwest...

  7. LBA-ECO CD-08 Tree Diameter Measurements, Jacaranda Plots, Manaus, Brazil: 1999-2001

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set provides diameter at breast height (DBH) measurements made of trees in a dense terra-firme tropical moist forest at the ZF-2 Experimental Station, 90...

  8. Plasmonic Fano resonances in novel nanostructure consisting of two rings with different diameter

    Science.gov (United States)

    Liu, Tongtong; Shi, Yusen; Xia, Feng; Yun, Maojin

    2017-08-01

    In this paper, a novel metallic nanostructure consisting of two rings with different diameter is proposed to generate intense plasmonic Fano Resonances (FRs). In this nanostructure, the FRs is explained by the interference between spectrally overlapping narrow subradiant (dark) and broad superradiant (bright) plasmonic modes and is simulated by COMSOL Multiphysics based on Finite Element Method. The simulation shows that dipolar resonance only occurs in the small-diameter ring as a bright plasmon mode, other than the large-diameter ring. It can be found that the Fano resonance can be generated in a metallic nanostructure consisting of two rings with different diameter. Such structure will have many potential applications in the field of chemical and biological sensors in the future.

  9. A 3.4-mm beam diameter system for retinal imaging with OCT and adaptive optics

    Science.gov (United States)

    Reddikumar, Maddipatla; Cense, Barry

    2017-04-01

    We present an adaptive-optics optical coherence tomography (AO-OCT) system with 3.4-mm beam diameter. A deformable mirror is used for the correction of two radial Zernike orders (defocus, vertical and oblique astigmatism). The aberrations are corrected sequentially with a Shack-Hartmann wave-front sensor and the deformable mirror. This system fills a gap between a standard clinical 1.2-mm beam diameter OCT system and a 6-mm beam diameter AO-OCT system. We also present 8° by 8° en face OCT images from a patient with macular degeneration. This system has a 25 cm by 50 cm footprint, which makes it considerably smaller to conventional 6-mm beam diameter AO-OCT system. Because of its larger field of view and smaller size, it is likely to be useful in the ophthalmic clinics for high-resolution imaging of the human eye retina.

  10. Strong diameter-dependence of nanowire emission coupled to waveguide modes

    Energy Technology Data Exchange (ETDEWEB)

    Dam, Dick van, E-mail: a.d.v.dam@tue.nl; Haverkort, Jos E. M. [Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven (Netherlands); Abujetas, Diego R.; Sánchez-Gil, José A. [Instituto de Estructura de la Materia (IEM-CSIC), Consejo Superior de Investigaciones Científicas Serrano, 121, 28006 Madrid (Spain); Bakkers, Erik P. A. M. [Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven (Netherlands); Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft (Netherlands); Gómez Rivas, Jaime, E-mail: j.gomezrivas@differ.nl [Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven (Netherlands); Dutch Institute for Fundamental Energy Research DIFFER, P.O. Box 6336, 5600 HH Eindhoven (Netherlands)

    2016-03-21

    The emission from nanowires can couple to waveguide modes supported by the nanowire geometry, thus governing the far-field angular pattern. To investigate the geometry-induced coupling of the emission to waveguide modes, we acquire Fourier microscopy images of the photoluminescence of nanowires with diameters ranging from 143 to 208 nm. From the investigated diameter range, we conclude that a few nanometers difference in diameter can abruptly change the coupling of the emission to a specific mode. Moreover, we observe a diameter-dependent width of the Gaussian-shaped angular pattern in the far-field emission. This dependence is understood in terms of interference of the guided modes, which emit at the end facets of the nanowire. Our results are important for the design of quantum emitters, solid state lighting, and photovoltaic devices based on nanowires.

  11. LBA-ECO ND-02 Secondary Forest Tree Heights and Diameters, Para, Brazil: 1999-2005

    Data.gov (United States)

    National Aeronautics and Space Administration — ABSTRACT: This data set provides tree diameters and heights measured from 1999 to 2005 in plots of a secondary-growth forest fertilization experiment located 6.5-km...

  12. Estimates of Radiation Dose Rates Near Large Diameter Sludge Containers in T Plant

    CERN Document Server

    Himes, D A

    2002-01-01

    Dose rates in T Plant canyon during the handling and storage of large diameter storage containers of K Basin sludge were estimated. A number of different geometries were considered from which most operational situations of interest can be constructed.

  13. Measuring the diameter of rising gas bubbles by means of the ultrasound transit time technique

    Energy Technology Data Exchange (ETDEWEB)

    Richter, T., E-mail: Thomas.Richter6@tu-dresden.de; Eckert, K., E-mail: Kerstin.Eckert@tu-dresden.de; Yang, X.; Odenbach, S.

    2015-09-15

    Highlights: • Ultrasound transit time technique (UTTT) is applied to the zig-zag raise of gas bubble. • Comparison of bubble diameter and tilt, measured by UTTT, with high-speed imaging. • Uncertainty in the determination of the bubble diameter by UTTT is less than 7%. • UTTT is able to measure dynamic changes in bubble size in opaque liquids and vessels. • UTTT can be applied to liquid metal loops. - Abstract: This study presents ultrasound transit time technique (UTTT) measurements of the diameter variations of single argon bubbles rising in a zig-zag trajectory in water. Simultaneous size measurements with a high-speed camera show that UTTT resolves both the apparent diameter and the tilt of the bubble axis with an accuracy of better than 7%. This qualifies UTTT for the measurement of bubble sizes in opaque liquids, such as liquid metals, or vessels.

  14. Centrifuge modelling of large diameter pile in sand subject to lateral loading

    DEFF Research Database (Denmark)

    Leth, Caspar Thrane

    regulations are developed for long flexible piles with diameters up to approximately 2.0 m and are based on a very limited number of tests. Hence, the method has not been validated for rigid piles with diameters of 4 to 6 m. The primary issues concerning the validity of the standard p-y curves for large...... diameter rigid piles are:  The initial stiffness of the curves and description of the static behaviour, including ultimate bearing capacity.  The behaviour with respect to cyclic loading both stiffness degradation and ultimate bearing capacity. The aim of the present research is to investigate the static...... and cyclic behaviour of large diameter rigid piles in dry sand by use of physical modelling. The physical modelling has been carried out at Department of Civil Engineering at the Danish Technical University (DTU.BYG), in the period from 2005 to 2009. The main centrifuge facilities, and especially...

  15. Development of a 1.0 mm inside diameter temperature-assisted focusing precolumn for use with 2.1 mm inside diameter columns.

    Science.gov (United States)

    Groskreutz, Stephen R; Horner, Anthony R; Weber, Stephen G

    2017-11-10

    On-column solute focusing is a simple and powerful method to decrease the influence of precolumn band spreading and increase the allowable volume injected increasing sensitivity. It relies on creating conditions so that the retention factor, k', is transiently increased during the injection process. Both solvent composition and temperature control can be used to effect solute focusing. In the case of temperature, the release of the transiently delayed solute band requires increasing the temperature rapidly and with a minimum of radial thermal gradients. Thus, the focus of attention in temperature-based efforts to carry out on-column focusing has been on capillary columns. As a result, the benefits of this simple and reliable approach, temperature-assisted solute focusing or TASF, are not available to those using larger diameter columns, in particular the highly successful 2.1mm inside diameter columns. Based on considerations of thermal entrance length at the volume flow rates used with 2.1mm inside diameter columns, TASF would not be effective with such columns. However, we determined that the thermal entrance length for a 1.0mm inside diameter precolumn is sufficiently short, about 2mm, that it could work as a precolumn before a 2.1mm inside diameter analytical column. Finite element calculations demonstrate that a 1.0×20mm precolumn packed with 5μm reversed phase particles is effective at a flow rate of 250μL/min, suitable for the 2.1mm inside diameter column. Eight 1-cm(2) Peltier devices are used to heat (and cool) the precolumn. The computed axial temperature profile shows that the center of the column heats more rapidly than the ends. Based on the changes in back pressure, the full temperature transient from 5°C (focus) to 80°C (release) takes about 10s. Experimental van Deemter curves indicate that the reduced velocity in the precolumn at 250μL/min flow rate is about 50. Nonetheless, about 1000 theoretical plates are generated. When operating as a

  16. Ecological Importance of Large-Diameter Trees in a Temperate Mixed-Conifer Forest

    Science.gov (United States)

    Lutz, James A.; Larson, Andrew J.; Swanson, Mark E.; Freund, James A.

    2012-01-01

    Large-diameter trees dominate the structure, dynamics and function of many temperate and tropical forests. Although both scaling theory and competition theory make predictions about the relative composition and spatial patterns of large-diameter trees compared to smaller diameter trees, these predictions are rarely tested. We established a 25.6 ha permanent plot within which we tagged and mapped all trees ≥1 cm dbh, all snags ≥10 cm dbh, and all shrub patches ≥2 m2. We sampled downed woody debris, litter, and duff with line intercept transects. Aboveground live biomass of the 23 woody species was 507.9 Mg/ha, of which 503.8 Mg/ha was trees (SD = 114.3 Mg/ha) and 4.1 Mg/ha was shrubs. Aboveground live and dead biomass was 652.0 Mg/ha. Large-diameter trees comprised 1.4% of individuals but 49.4% of biomass, with biomass dominated by Abies concolor and Pinus lambertiana (93.0% of tree biomass). The large-diameter component dominated the biomass of snags (59.5%) and contributed significantly to that of woody debris (36.6%). Traditional scaling theory was not a good model for either the relationship between tree radii and tree abundance or tree biomass. Spatial patterning of large-diameter trees of the three most abundant species differed from that of small-diameter conspecifics. For A. concolor and P. lambertiana, as well as all trees pooled, large-diameter and small-diameter trees were spatially segregated through inter-tree distances trees and spatial relationships between large-diameter and small-diameter trees. Long-term observations may reveal regulation of forest biomass and spatial structure by fire, wind, pathogens, and insects in Sierra Nevada mixed-conifer forests. Sustaining ecosystem functions such as carbon storage or provision of specialist species habitat will likely require different management strategies when the functions are performed primarily by a few large trees as opposed to many smaller trees. PMID:22567132

  17. Correlation between the milk vein internal diameter surface andmilk yield in Simmental cows

    OpenAIRE

    GRACNER, DAMJAN; GILLIGAN, GERARD; GARVEY, NICKHOLAS; Moreira,Luis; Harvey, Patricia; TIERNEY, AMANDA; ZOBEL, Robert

    2015-01-01

    It is known that milk production is directly correlated with the blood flow through the mammary gland, and milk veins drain approximately 90% of the total blood passing through this organ. The aim of the present study was to determine the relationship between milk vein internal diameter surface and milk production in Simmental cows. The milk vein internal diameter was measured by ultrasonography in heifers during the 2nd month of the first gravidity, and again on day 50 following the second c...

  18. Economic feasibility of products from inland west small-diameter timber. Forest Service general technical report

    Energy Technology Data Exchange (ETDEWEB)

    Spelter, H.; Wang, R.; Ince, P.

    1996-05-01

    A large part of the forests located in the Rocky Mountain region of the U.S. West (inland West) is characterized by densely packed, small-diameter stands. The purpose of this study was to examine the economic feasibility of using small-diameter material from this resource to manufacture various wood products: oriented strandboard (OSB), stud lumber, random-length dimension lumber, machine-stress-rated random-length lumber, laminated veneer lumber (LVL), and market pulp.

  19. STUDY OF VARIATION OF THE DIAMETER OF THE SPINAL CANAL AND THE FORAMINA IN SPONDYLOLISTHESIS

    Directory of Open Access Journals (Sweden)

    Enguer Beraldo Garcia

    2016-03-01

    Full Text Available ABSTRACT Objective: To define and quantify the degree of change of the spinal canal diameter in patients with degenerative and spondylolytic spondylolisthesis. Methods: We studied CT scans of 54 patients. Of this total, 37 (29 women and 8 men had degenerative type and 17 (7 women and 10 men had spondylolytic type. Results: In the degenerative spondylolisthesis group, the average diameter of the spinal canal at the injured vertebra level was 17.35 mm and 17.64 mm for the upper vertebra level. The average diameter of the foramen at the level of the affected vertebra was 14.61 mm to left side and 15.00 mm to the right side. The average diameter of the foramen at the upper vertebra level was 16.82 mm to the left side and 16.51 mm to the right side. In the spondylolytic group, the average diameter of the spinal canal at the level of the affected vertebra was 23.25 mm and at the upper vertebra level was 18.66 mm. The average diameter of the foramen at the level of the affected vertebra was 11.98 mm to the left side and 12.34 mm to the right side. The average diameter of the foramen at the level of the upper vertebra was 16.97 mm to the left side and 15.58 mm to the right side. Conclusion: The diameter of the spinal canal in the sagittal plane showed no statistically significant increase in the spondylolytic spondylolisthesis group, in contrast to what is found in the degenerative spondylolisthesis group. It was also observed a reduction in vertebral foramina of the injured level in both groups.

  20. Individual-tree diameter growth model for managed, even-aged, upland oak stands

    Science.gov (United States)

    Donald E. Hilt

    1983-01-01

    A distance-independent, individual-tree diameter growth model was developed for managed, even-aged, upland oak stands. The 5-year basal-area growth of individual trees is first modeled as a function of dbh squared for given stands. Parameters from these models are then modeled as a function of mean stand diameter, percent stocking of the stand, and site index. A...

  1. Measurement of the aortic diameter in the asymptomatic Korean population: Assessment with multidetector CT

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sang Hwan; Lee, Whal; Choi, Hyuck Jae; Kim, Dae Jin; Park, Eun Ah; Chung, Jin Wook; Park, Jae Hyung [Dept. of Radiology, Seoul National University College of Medicine, Seoul (Korea, Republic of)

    2013-08-15

    To determine normal reference values for aortic diameters in asymptomatic Korean adults. Three hundred adults without signs or symptoms of cardiovascular diseases were enrolled in this study. Aortic diameters were measured at nine predetermined levels on CT images. Aortic diameter measurements were adjusted for body surface area. Analysis of data was performed with regard to age, sex, weight, height and hypertension. Aortic diameters were 2.99 ± 0.57 cm at the ascending aorta, 2.54 ± 0.35 cm at the transverse aortic arch, 2.36 ± 0.35 cm at the proximal descending thoracic aorta (DTA), 2.23 ± 0.37 cm at the mid DTA, 2.17 ± 0.38 cm at the distal DTA, 2.16 ± 0.37 cm at the thoracoabdominal junction, 2.10, 00B1, 0.35 cm at the level of the celiac axis, 1.94, 00B1, 0.36 cm at the suprarenal aorta, 1.58 ± 0.24 cm at the aortic bifurcation. Men had slightly larger diameters than women (p < 0.05). All diameters increased with age and hypertension, with statistical significance (p < 0.01). And all aortic diameters increased with height (p < 0.05) except at the level of the aortic arch (p = 0.056), and increased with weight (p < 0.05) except at the level of the suprarenal aorta (p = 0.067). Male sex, higher weight and height, age and hypertension are associated with larger aortic diameters in asymptomatic Korean adults.

  2. Height-Diameter Equations for 12 Upland Species in the Missouri Ozark Highlands

    Science.gov (United States)

    J.R. Lootens; David R. Larsen; Stephen R. Shifley

    2007-01-01

    We calibrated a model predicting total tree height as a function of tree diameter for nine tree species common to the Missouri Ozarks. Model coefficients were derived from nearly 10,000 observed trees. The calibrated model did a good job predicting the mean height-diameter trend for each species (pseudo-R2 values ranged from 0.56 to 0.88), but...

  3. The first observations of oocyte diameters for the pipefish from the southern Black Sea

    OpenAIRE

    Gürkan, Şule; Taylan, Burcu

    2015-01-01

    Abstract Syngnathid specimens sample between July 2001˗May 2002 was examined about measurements of oocyte diameter in the coastal waters of Sinop peninsula, southern Back Sea. The specimens of Syngnathid fishes (Syngnathus acus, Syngnathus typhle, Syngnathus variegatus, Syngnathus tenuirostris, Nerophis ophidion) catched with using hand dredge from the vegetated coastal area. According to results, the mean of hydrated oocyte diameter was calculated as, respectively: Syngnathus acus: 1.96 mm, ...

  4. Spontaneous high frequency diameter oscillations of larger retinal arterioles are reduced in type 2 diabetes mellitus

    DEFF Research Database (Denmark)

    Bek, Toke; Jeppesen, Peter; Kanters, Jørgen K.

    2013-01-01

    Diabetic retinopathy is characterized by morphological changes in the retina secondary to disturbances in retinal blood flow. Vasomotion is a mechanism for regulating blood flow by spontaneous oscillations in the diameter of retinal resistance arterioles, and has been shown to be disturbed outside...... the eye in diabetic patients. Therefore, the purpose of the present study was to characterize spontaneous oscillations in the diameter of retinal arterioles in normal persons and in persons with different severity of diabetic retinopathy....

  5. Effect of brimonidine tartrate 0.10% ophthalmic solution on pupil diameter.

    Science.gov (United States)

    Shemesh, Gabi; Moisseiev, Elad; Lazar, Moshe; Kesler, Anat

    2011-03-01

    To evaluate the effect of brimonidine tartrate 0.10% ophthalmic solution on pupil diameter under light and dark luminance conditions. Ophthalmology Department, Tel Aviv Medical Center, Tel Aviv, Israel. Case series. The pupil diameter was measured with a Colvard pupillometer in eyes of healthy volunteers under light (5.0 candelas [cd]/m(2)) and dark (0.0 cd/m(2)) luminance conditions before brimonidine 0.10% instillation and after 30 minutes, 3 hours, and 6 hours. The mean age of the 26 volunteers (52 eyes) was 34.73 years (range 19 to 60 years). Under light conditions, the mean pupil diameter was 4.98 mm ± 0.83 (SD) before instillation of brimonidine 0.10% and 4.64 ± 0.82 mm after instillation. The difference was not statistically significant, with 13.4% of eyes having a clinically significant reduction (>1.0 mm) in pupil diameter after 6 hours. Under dark conditions, the mean pupil diameter was 6.76 ± 1.08 mm before instillation of brimonidine 0.10% and 5.30 ± 0.85 mm after instillation; the difference was statistically significant (PBrimonidine 0.10% ophthalmic solution had an antimydriatic effect under dark luminance conditions and had a negligible effect on pupil diameter under light luminance conditions. The effect was similar to that reported in studies using higher concentrations of brimonidine. Copyright © 2011 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  6. The Conditional Fault-Diameter of the K-ary n-Cube

    Directory of Open Access Journals (Sweden)

    Khaled Day

    2005-06-01

    Full Text Available We obtain the conditional fault diameter of the k-ary n-cube interconnection network. It has been previously shown that under the condition of forbidden faulty sets (i.e. assuming each non-faulty node has at least one non-faulty neighbor, the k-ary n-cube, whose connectivity is 2n, can tolerate up to 4n-3 faulty nodes without becoming disconnected. We extend this result by showing that the conditional fault-diameter of the k-ary n-cube is equal to the fault-free diameter plus two. This means that if there are at most 4n-3 faulty nodes in the k-ary n-cube and if every non-faulty node has at least one non-faulty neighbor, then there exists a fault-free path of length at most the diameter plus two between any two non faulty nodes. We also show how to construct these fault-free paths. With this result the k-ary n-cube joins a group of interconnection networks (including the hypercube and the star-graph whose conditional fault diameter has been shown to be only two units over the fault-free diameter.

  7. Rubbing test responses of the skin to man-made mineral fibres of different diameters.

    Science.gov (United States)

    Stam-Westerveld, E B; Coenraads, P J; van der Valk, P G; de Jong, M C; Fidler, V

    1994-07-01

    The irritant potency of 5 types of insulation wools (2 types of rockwool and 3 types of glasswool) were studied on the basis of their differences in diameter by a standardized rubbing test. Assessment was done by laser Doppler flowmetry (LDF) and erythema scores. Insulation wools show a wide distribution of the diameter around the mean. Of the rockwool material, 30% consisted of small grains, called "shot". The control test site did not change over time; thus, the rubbing procedure itself does not seem to contribute to the skin reactions. All fibre types proved to be irritant to the skin. The irritant reactions did not correspond with the mean diameter, although the fibre type with the smallest diameter was the least irritant and the fibre type with the largest diameter the strongest. The presence of "shot" had a significant effect on the LDF responses. "Shot" and the distribution around the mean diameter may play a role in eliciting the skin irritation by insulation wools.

  8. Small infrarenal aortic diameter associated with lower-extremity peripheral artery disease in Chinese hypertensive adults.

    Science.gov (United States)

    Liu, Jie; Jia, Xin; Jia, Senhao; Qin, Xianhui; Zhang, Tao; Liu, Lishun; Li, Haibo; Rong, Dan; Zhou, Ziyi; Song, Yuxiang; Zuo, Shangwei; Duan, Chen; Wu, Zhongyin; Wei, Ren; Ge, Yangyang; Wang, Xian; Kong, Wei; Xu, Xiping; Khalil, Raouf A; Huo, Yong; Guo, Wei

    2017-11-06

    Several studies suggest that infrarenal aortic diameter is associated with lower-extremity peripheral artery disease (LE-PAD). However, data regarding the associations between infrarenal aortic diameter and LE-PAD are limited, especially in large sample populations and Asian or Chinese populations. Our analysis included 17279 Chinese hypertensive adults comprising 6590 men and 10689 women with a mean age of 64.74 ± 7.41 years. Participants were selected from 22693 candidates from two large population-based cohort-studies. The primary noninvasive test for diagnosis of LE-PAD is the ankle-brachial index (ABI) at rest and typically an ABI ≤ 0.90 is used to define LE-PAD. The prevalence of LE-PAD was found to significantly decrease as the aortic diameter increased according to the tertile of the aortic diameter. LE-PAD was significantly more prevalent in the lowest tertile (OR = 1.58, 95% CI = 1.29-1.94, p  0.05). In conclusion, Small aortic diameter (as opposed to large aortic diameter) is significantly associated with LE-PAD in Chinese hypertensive adults.

  9. Common Carotid Artery Diameter and Cardiovascular Risk Factors in Overweight or Obese Postmenopausal Women

    Directory of Open Access Journals (Sweden)

    Kelly D. Lloyd

    2012-01-01

    Full Text Available Arterial diameter is an underutilized indicator of vascular health. We hypothesized that interadventitial and lumen diameter of the common carotid artery would be better indicators of vascular health than carotid plaque or intima media thickness (IMT. Participants were 491 overweight or obese, postmenopausal women who were former or current hormone therapy (HT users, 52–62 years, with waist circumference >80 cm. We evaluated cross-sectional associations of cardiovascular risk factors with carotid measures, by HT status. Former HT users had a worse cardiovascular profile than current HT users: larger adventitial (6.94 mm versus 6.79 mm and lumen diameter (5.44 mm versus 5.31 mm, both P<0.01 independent of cardiovascular risk factors; IMT and plaque were similar. Larger diameters were best explained by former HT use, higher pulse pressure, and greater weight. Independent of potential confounders, overweight and obese postmenopausal former HT users had larger carotid diameters than current HT users. Carotid diameter should be considered in studies of HT.

  10. Narrow-diameter implants: are they a predictable treatment option? A literature review.

    Science.gov (United States)

    Sierra-Sánchez, José-Luis; Martínez-González, Amparo; García-Sala Bonmatí, Fernando; Mañes-Ferrer, José-Félix; Brotons-Oliver, Alejandro

    2014-01-01

    To evaluate the predictability of narrow-diameter implants as a treatment option in routine clinical practice. A literature review was performed of studies reporting clinical results obtained with these implants. Survival rates, peri-implant bone loss and related complications were evaluated. The working hypothesis was that narrow-diameter implants offer clinical results similar to those obtained with implants of greater diameter. A Medline-PubMed search covering the period between 2002 and 2012 was carried out. Studies published in English and with a follow-up period of at least 12 months were considered for inclusion. A manual search was also conducted in different journals with an important impact factor. results: Twenty-one studies meeting the screening criteria were included in the literature review. A total of 2980 narrow-diameter implants placed in 1607 patients were analyzed. The results obtained from the literature indicate that narrow-diameter implants are a predictable treatment option, since they afford clinical results comparable to those obtained with implants of greater diameter.

  11. Gender differences in coronary artery diameter are not related to body habitus or left ventricular mass.

    Science.gov (United States)

    Hiteshi, Amit K; Li, Dong; Gao, Yanlin; Chen, Andy; Flores, Ferdinand; Mao, Song Shou; Budoff, Matthew J

    2014-10-01

    Smaller coronary artery diameter portends worse outcomes after coronary artery bypass grafting (CABG) and percutaneous coronary intervention (PCI). The suggestion that women have smaller coronary artery diameters than men has not been validated by a large-scale study. We sought to confirm a gender difference with respect to coronary artery diameter, even after accounting for body habitus and left ventricular mass (LVM). From 4200 subjects evaluated for cardiovascular disease by computed tomography angiography, we selected 710 subjects (383 males, 327 females) with coronary artery calcium (CAC) scores habitus and LVM. After adjusting for age, race, weight, height, body mass index, body surface index, LVM, and CAC, women have smaller diameters in the LM (males 4.35 mm, females 3.91 mm), LAD (males 3.54 mm, females 3.24 mm), CX (males 3.18, females 2.75 mm), and RCA (males 3.70 mm, females 3.26 mm) (P habitus or LVM. Gender significantly influences artery diameter of the LM, LAD, CX, and RCA. This may warrant gender specific approaches during PCI and CABG. As neither body habitus nor LVM relate to the difference in coronary artery diameter, our study encourages a search for inherent differences between genders that can account for this difference. © 2014 Wiley Periodicals, Inc.

  12. MreB helical pitch angle determines cell diameter in Escherichia coli

    CERN Document Server

    Ouzounov, Nikolay; Bratton, Benjamin; Jacobowitz, David; Gitai, Zemer; Shaevitz, Joshua W

    2015-01-01

    Bacteria have remarkably robust cell shape control mechanisms. For example, cell diameter only varies by a few percent across a population. MreB is necessary for establishment and maintenance of rod shape although the mechanism of shape control remains unknown. We perturbed MreB in two complimentary ways to produce steady-state cell diameters over a wide range, from 790+/-30 nm to 1700+/-20 nm. To determine which properties of MreB are important for diameter control, we correlated structural characteristics of fluorescently-tagged MreB polymers with cell diameter by simultaneously analyzing 3-dimensional images of MreB and cell shape. Our results indicate that the pitch angle of MreB inversely correlates with cell diameter. Other correlations are not found to be significant. These results demonstrate that the physical properties of MreB filaments are important for shape control and support a model in which MreB dictates cell diameter and organizes cell wall growth to produce a chiral cell wall.

  13. Evaluation of the splats properties and relation with droplets diameters in atomization process using a De Laval Nozzle

    Energy Technology Data Exchange (ETDEWEB)

    Planche, Marie-Pierre, E-mail: marie-pierre.planche@utbm.fr [LERMPS-UTBM Site de Sevenans, 90010 Belfort, Cedex (France); Khatim, Othmane; Dembinski, Lucas [LERMPS-UTBM Site de Sevenans, 90010 Belfort, Cedex (France); Bailly, Yannick [Institute FEMTO-ST/ENISYS, University of Franche-Comte, UMR CNRS 6174, 90000 Belfort (France); Coddet, Christian [LERMPS-UTBM Site de Sevenans, 90010 Belfort, Cedex (France)

    2013-01-15

    Properties of the powders developed during atomization process are essentially determined by process parameters. Experiments based on splat collection have been performed at different stages of the process evolution. Formation of splat formed as a result of impingement of the melted metallic droplets onto a substrate was studied. Splat characteristics have been determined from image analysis in function of process parameters and time progress. Droplet diameters were measured using laser Coulter analyzer. Direct relationships between splat diameter and droplet diameter were established. The atomization experiments point out the strong influence of two processing parameters (atomizing gas and melt nozzle diameter) on splat characteristics and particle size. It has been observed that increasing atomizing pressure leads to a decrease of mean splat diameter and width of the size distribution. Similar evolution was found for droplet diameter. Moreover, it is clearly shown that increasing melt nozzle diameter induces an increase of both splat diameters and droplet diameters. The results provide a better understanding of the influence of atomization parameters on the size distribution. Highlights: Black-Right-Pointing-Pointer In this study, changes of splat characteristics were examined versus operating parameters. Black-Right-Pointing-Pointer Splat diameter decreases with the increase of atomizing pressure. Black-Right-Pointing-Pointer Splat diameter decreases with the decrease of the melt nozzle diameter. Black-Right-Pointing-Pointer Changes of droplet diameter are in good agreement with those of splat diameter.

  14. Sprouting ability and biomass production of downy and silver birch stumps of different diameters

    Energy Technology Data Exchange (ETDEWEB)

    Johansson, Tord [Department of Bioenergy, Swedish University of Agricultural Sciences, SE-750 07 Uppsala (Sweden)

    2008-10-15

    The aim of this study was to compare the sprouting ability of stumps of different diameters of downy (Betula pubescens Ehrh.) and silver (Betula pendula Roth) birch. The number of living stumps, and the number and height of sprouts were recorded annually and the biomass of the sprouts was calculated. Two hundred naturally regenerated downy and silver birches were examined. These were part of a commercial cleaning in late August 1983, which left 20-cm-high stumps. The experimental site was located on forest land in central Sweden (latitude 60 15'N, longitude 16 01'E). The stumps were categorised into four diameter classes: 10-19, 20-29, 30-39 and 40-50 mm. The site was examined in September of the year after cutting and on a number of occasions up to 9 years after cutting. The number of living stumps of each species was recorded. When the sprouts were 9 years old, their diameter at breast height was recorded. Then, the sprouts were cut and stems and branches were dried and weighted. After 1 and 9 years, the percentage of surviving downy birch stumps was 90% and 61%, respectively. The equivalent figures for silver birch were 82% and 55%. The number of sprouts per stump differed significantly between the species and the stump diameter classes. The greatest mean number of downy birch sprouts per stump (2.8{+-}0.3) was for the diameter class 40-50 mm, and for silver birch sprouts (2.3{+-}0.2), for the 30-39 mm stumps. The diameter at breast height, height and weight of individual sprouts 9 years after cutting were significantly different between downy and silver birches and the diameter classes. The mean downy birch sprout weight (1.00{+-}0.01 kg d.w. stump{sup -1}) varied between diameter classes and the heaviest sprout weight (1.18{+-}0.02 kg d.w. stump{sup -1}) was produced by 30-39 mm stumps. The heaviest silver birch sprout, 1.94{+-}0.04 kg d.w., was also produced by 40-50 mm stumps. The mean weight was 1.55{+-}0.05 kg d.w. The sprout biomass per living

  15. Measurements of stem diameter: implications for individual- and stand-level errors.

    Science.gov (United States)

    Paul, Keryn I; Larmour, John S; Roxburgh, Stephen H; England, Jacqueline R; Davies, Micah J; Luck, Hamish D

    2017-08-01

    Stem diameter is one of the most common measurements made to assess the growth of woody vegetation, and the commercial and environmental benefits that it provides (e.g. wood or biomass products, carbon sequestration, landscape remediation). Yet inconsistency in its measurement is a continuing source of error in estimates of stand-scale measures such as basal area, biomass, and volume. Here we assessed errors in stem diameter measurement through repeated measurements of individual trees and shrubs of varying size and form (i.e. single- and multi-stemmed) across a range of contrasting stands, from complex mixed-species plantings to commercial single-species plantations. We compared a standard diameter tape with a Stepped Diameter Gauge (SDG) for time efficiency and measurement error. Measurement errors in diameter were slightly (but significantly) influenced by size and form of the tree or shrub, and stem height at which the measurement was made. Compared to standard tape measurement, the mean systematic error with SDG measurement was only -0.17 cm, but varied between -0.10 and -0.52 cm. Similarly, random error was relatively large, with standard deviations (and percentage coefficients of variation) averaging only 0.36 cm (and 3.8%), but varying between 0.14 and 0.61 cm (and 1.9 and 7.1%). However, at the stand scale, sampling errors (i.e. how well individual trees or shrubs selected for measurement of diameter represented the true stand population in terms of the average and distribution of diameter) generally had at least a tenfold greater influence on random errors in basal area estimates than errors in diameter measurements. This supports the use of diameter measurement tools that have high efficiency, such as the SDG. Use of the SDG almost halved the time required for measurements compared to the diameter tape. Based on these findings, recommendations include the following: (i) use of a tape to maximise accuracy when developing allometric models, or when

  16. Bubble detachment and lift-off diameters at a vertical heated wall for subcooled boiling flow

    Energy Technology Data Exchange (ETDEWEB)

    Montout, Michael; Haynes, Pierre-Antoine; Peturaud, Pierre [EDF, R and D Division, Fluid Dynamics, Power Generation and Environnement Department, 6 quai Watier, 78401 Chatou Cedex (France); Colin, Catherine [Institut de Mecanique des Fluides de Toulouse, Allee du Professeur Camille Soula, 31400 Toulouse (France)

    2008-07-01

    Full text of publication follows: In the framework of the NEPTUNE project jointly carried on by EDF, CEA, AREVA NP and IRSN (Guelfi et al. (2007)), the development of the NEPTUNE-CFD code aims at (among others) improving the prediction of the Departure from Nucleate Boiling (DNB) in Pressurized Water Reactors (PWRs). In this prospect, the modeling of boiling flows up to the DNB is of prime importance, and this presentation is devoted to one major related phenomenon, the wall-to-flow heat transfer in subcooled boiling flow. Computational Fluid Dynamics (CFD) modeling of subcooled nucleate boiling has to provide the net vapor generation rate at the heated wall, as well as its related geometrical characteristic - either bubble diameter or interfacial area concentration (its velocity might also be useful). For this purpose, mechanistic models are used. Previous models (such as the widely used Kurul and Podowski model (1990)) are based on the bubble lift-off diameter, diameter from which the bubble leaves the wall to be swept along the bulk liquid flow. However, for a few years, new models (Basu et al. (2005) or Yeoh et al. (2008)) account for a finer phenomenology (bubble sliding along the heated wall) and require the knowledge of the bubble detachment diameter, diameter from which the bubble leaves its nucleation site to slide along the heated wall. Modeling these diameters is still an issue. On the one hand, several (semi-) empirical correlations are available in the open literature making it possible to provide the liftoff diameter (Uenal (1976), for instance), but they are still questionable; on the other hand, there is a great lack of information with respect to the evaluation of the detachment diameter. Therefore to progress on these concerns, an analytical work has been carried out. In a first step, a methodology providing detachment and lift-off diameters is proposed and applied. This approach is based on the resolution of a force balance model acting on a

  17. Fully automatic left ventricular myocardial strain estimation in 2D short-axis tagged magnetic resonance imaging

    Science.gov (United States)

    Morais, Pedro; Queirós, Sandro; Heyde, Brecht; Engvall, Jan; 'hooge, Jan D.; Vilaça, João L.

    2017-09-01

    Cardiovascular diseases are among the leading causes of death and frequently result in local myocardial dysfunction. Among the numerous imaging modalities available to detect these dysfunctional regions, cardiac deformation imaging through tagged magnetic resonance imaging (t-MRI) has been an attractive approach. Nevertheless, fully automatic analysis of these data sets is still challenging. In this work, we present a fully automatic framework to estimate left ventricular myocardial deformation from t-MRI. This strategy performs automatic myocardial segmentation based on B-spline explicit active surfaces, which are initialized using an annular model. A non-rigid image-registration technique is then used to assess myocardial deformation. Three experiments were set up to validate the proposed framework using a clinical database of 75 patients. First, automatic segmentation accuracy was evaluated by comparing against manual delineations at one specific cardiac phase. The proposed solution showed an average perpendicular distance error of 2.35  ±  1.21 mm and 2.27  ±  1.02 mm for the endo- and epicardium, respectively. Second, starting from either manual or automatic segmentation, myocardial tracking was performed and the resulting strain curves were compared. It is shown that the automatic segmentation adds negligible differences during the strain-estimation stage, corroborating its accuracy. Finally, segmental strain was compared with scar tissue extent determined by delay-enhanced MRI. The results proved that both strain components were able to distinguish between normal and infarct regions. Overall, the proposed framework was shown to be accurate, robust, and attractive for clinical practice, as it overcomes several limitations of a manual analysis.

  18. Fully automatic left ventricular myocardial strain estimation in 2D short-axis tagged magnetic resonance imaging.

    Science.gov (United States)

    Morais, Pedro; Queirós, Sandro; Heyde, Brecht; Engvall, Jan; 'hooge, Jan D; Vilaça, João L

    2017-08-07

    Cardiovascular diseases are among the leading causes of death and frequently result in local myocardial dysfunction. Among the numerous imaging modalities available to detect these dysfunctional regions, cardiac deformation imaging through tagged magnetic resonance imaging (t-MRI) has been an attractive approach. Nevertheless, fully automatic analysis of these data sets is still challenging. In this work, we present a fully automatic framework to estimate left ventricular myocardial deformation from t-MRI. This strategy performs automatic myocardial segmentation based on B-spline explicit active surfaces, which are initialized using an annular model. A non-rigid image-registration technique is then used to assess myocardial deformation. Three experiments were set up to validate the proposed framework using a clinical database of 75 patients. First, automatic segmentation accuracy was evaluated by comparing against manual delineations at one specific cardiac phase. The proposed solution showed an average perpendicular distance error of 2.35  ±  1.21 mm and 2.27  ±  1.02 mm for the endo- and epicardium, respectively. Second, starting from either manual or automatic segmentation, myocardial tracking was performed and the resulting strain curves were compared. It is shown that the automatic segmentation adds negligible differences during the strain-estimation stage, corroborating its accuracy. Finally, segmental strain was compared with scar tissue extent determined by delay-enhanced MRI. The results proved that both strain components were able to distinguish between normal and infarct regions. Overall, the proposed framework was shown to be accurate, robust, and attractive for clinical practice, as it overcomes several limitations of a manual analysis.

  19. Dynamic Ultrasound-Guided Short-Axis Needle Tip Navigation Technique for Facilitating Cannulation of Peripheral Veins in Obese Patients.

    Science.gov (United States)

    Ueda, Kenichi; Hussey, Patrick

    2017-03-01

    This preliminary observational study evaluated a specific ultrasound technique for venous access. Ultrasound was utilized for navigating a needle and catheter within the vessel lumen after venopuncture. One hundred adult obese surgical patients without visible vessels on their upper extremities were enrolled. Forty-five different operators ranging from medical students to attending anesthesia faculty performed venous cannulation with the specific ultrasound technique. Veins in 95 patients were cannulated successfully on the first attempt. This ultrasound-guided protocol facilitates navigation of both the catheter and needle within a vessel, increasing the first-attempt success rate of peripheral venous cannulation in adult obese patients.

  20. Automatic left ventricle segmentation using iterative thresholding and an active contour model with adaptation on short-axis cardiac MRI.

    Science.gov (United States)

    Lee, Hae-Yeoun; Codella, Noel C F; Cham, Matthew D; Weinsaft, Jonathan W; Wang, Yi

    2010-04-01

    An automatic left ventricle (LV) segmentation algorithm is presented for quantification of cardiac output and myocardial mass in clinical practice. The LV endocardium is first segmented using region growth with iterative thresholding by detecting the effusion into the surrounding myocardium and tissues. Then the epicardium is extracted using the active contour model guided by the endocardial border and the myocardial signal information estimated by iterative thresholding. This iterative thresholding and active contour model with adaptation (ITHACA) algorithm was compared to manual tracing used in clinical practice and the commercial MASS Analysis software (General Electric) in 38 patients, with Institutional Review Board (IRB) approval. The ITHACA algorithm provided substantial improvement over the MASS software in defining myocardial borders. The ITHACA algorithm agreed well with manual tracing with a mean difference of blood volume and myocardial mass being 2.9 +/- 6.2 mL (mean +/- standard deviation) and -0.9 +/- 16.5 g, respectively. The difference was smaller than the difference between manual tracing and the MASS software (approximately -20.0 +/- 6.9 mL and -1.0 +/- 20.2 g, respectively). These experimental results support that the proposed ITHACA segmentation is accurate and useful for clinical practice.

  1. The Importance of Large-Diameter Trees to Forest Structural Heterogeneity

    Science.gov (United States)

    Lutz, James A.; Larson, Andrew J.; Freund, James A.; Swanson, Mark E.; Bible, Kenneth J.

    2013-01-01

    Large-diameter trees dominate the structure, dynamics and function of many temperate and tropical forests. However, their attendant contributions to forest heterogeneity are rarely addressed. We established the Wind River Forest Dynamics Plot, a 25.6 ha permanent plot within which we tagged and mapped all 30,973 woody stems ≥1 cm dbh, all 1,966 snags ≥10 cm dbh, and all shrub patches ≥2 m2. Basal area of the 26 woody species was 62.18 m2/ha, of which 61.60 m2/ha was trees and 0.58 m2/ha was tall shrubs. Large-diameter trees (≥100 cm dbh) comprised 1.5% of stems, 31.8% of basal area, and 17.6% of the heterogeneity of basal area, with basal area dominated by Tsuga heterophylla and Pseudotsuga menziesii. Small-diameter subpopulations of Pseudotsuga menziesii, Tsuga heterophylla and Thuja plicata, as well as all tree species combined, exhibited significant aggregation relative to the null model of complete spatial randomness (CSR) up to 9 m (P≤0.001). Patterns of large-diameter trees were either not different from CSR (Tsuga heterophylla), or exhibited slight aggregation (Pseudotsuga menziesii and Thuja plicata). Significant spatial repulsion between large-diameter and small-diameter Tsuga heterophylla suggests that large-diameter Tsuga heterophylla function as organizers of tree demography over decadal timescales through competitive interactions. Comparison among two forest dynamics plots suggests that forest structural diversity responds to intermediate-scale environmental heterogeneity and disturbances, similar to hypotheses about patterns of species richness, and richness- ecosystem function. Large mapped plots with detailed within-plot environmental spatial covariates will be required to test these hypotheses. PMID:24376579

  2. Different tracheotomy tube diameters influence diaphragmatic effort and indices of weanability in difficult to wean patients.

    Science.gov (United States)

    Valentini, Ilaria; Tonveronachi, Eva; Gregoretti, Cesare; Mega, Chiara; Fasano, Luca; Pisani, Lara; Nava, Stefano

    2012-12-01

    To determine the effects of different tracheotomy tube sizes on diaphragm effort and weanability indices. Ten tracheotomized and difficult to wean subjects were randomized to 2 T-piece trials, with different tracheotomy tube diameters: inner diameters 8 mm and 6.5 mm. Diaphragm pressure-time product per min. (PTP(di/min)), lung compliance and resistance (C(L) and R(L)), breathing pattern, tension-time index of the diaphragm (TT(di)), and the ratio of breathing frequency to tidal volume (f/V(T)) were recorded. In an in vitro model, the flow-pressure relationship was measured using the 2 tracheotomy tubes and 2 endotracheal tubes of the same diameter. The use of a smaller diameter resulted in an increase of PTP(di) (337.63 ± 194.35 cm H(2)O · s/min vs 263.28 ± 156.23 cm H(2)O · s/min for 6.5 mm and 8 mm, respectively, P = .004) and R(L) (16.74 ± 8.10 cm H(2)O · s/min vs 11.72 ± 7.88 cm H(2)O · s/min, respectively, P = .008). Both weanability indices were also significantly higher using the smaller tube: f/V(T) 93.32 ± 20.91 vs 77.06 ± 19.26 for 6.5 mm and 8 mm, respectively, P tracheotomy tubes and the endotracheal tubes of the same diameters. In tracheotomized difficult to wean subjects the decrease of the tracheotomy tube size was associated with an increased PTP(di), f/V(T), and TT(di), that were otherwise normal, using a higher diameter. The in vitro study showed that the resistances increased similarly for tracheotomy tube and endotracheal tube, decreasing the diameter and increasing the flows.

  3. Collagen fibrillogenesis in vitro: interaction of types I and V collagen regulates fibril diameter.

    Science.gov (United States)

    Birk, D E; Fitch, J M; Babiarz, J P; Doane, K J; Linsenmayer, T F

    1990-04-01

    The small-diameter fibrils of the chick corneal stroma are heterotypic, composed of both collagen types I and V. This tissue has a high concentration of type V collagen relative to other type I-containing tissues with larger-diameter fibrils, suggesting that heterotypic interactions may have a regulatory role in the control of fibril diameter. The interactions of collagen types I and V were studied using an in vitro self-assembly system. Collagens were purified from lathyritic chick embryos in the presence of protease inhibitors. The type V collagen preparations contained higher molecular weight forms of the alpha 1(V) and alpha 2(V) chains constituting 60-70% of the total. Rotary-shadow electron micrographs showed a persistence of a small, pepsin-sensitive terminal region in an amount consistent with that seen by electrophoresis. In vitro, this purified type V collagen formed thin fibrils with no apparent periodicity, while type I collagen fibrils had a broad distribution of large diameters. However, when type I collagen was mixed with increasing amounts of type V collagen a progressive and significant decrease in both the mean fibril diameter and the variance was observed for D periodic fibrils. The amino-terminal domain of the type V collagen molecule was required for this regulatory effect and in its absence little diameter reducing activity was observed. Electron microscopy using collagen type-specific monoclonal antibodies demonstrated that the fibrils formed were heterotypic, containing both collagen types I and V. These data indicate that the interaction of type V with type I collagen is one mechanism modulating fibril diameter and is at least partially responsible for the regulation of collagen fibril formation.

  4. Human intraretinal myelination: Axon diameters and axon/myelin thickness ratios

    Directory of Open Access Journals (Sweden)

    Thomas FitzGibbon

    2013-01-01

    Full Text Available Purpose: Human intraretinal myelination of ganglion cell axons occurs in about 1% of the population. We examined myelin thickness and axon diameter in human retinal specimens containing myelinated retinal ganglion cell axons. Materials and Methods: Two eyes containing myelinated patches were prepared for electron microscopy. Two areas were examined in one retina and five in the second retina. Measurements were compared to normal retinal and optic nerve samples and the rabbit retina, which normally contains myelinated axons. Measurements were made using a graphics tablet. Results: Mean axon diameter of myelinated axons at all locations were significantly larger than unmyelinated axons (P ≤ 0.01. Myelinated axons within the patches were significantly larger than axons within the optic nerve (P < 0.01. The relationship between axon diameter/fiber diameter (the G-ratio seen in the retinal sites differed from that in the nerve. G-ratios were higher and myelin thickness was positively correlated to axon diameter (P < 0.01 in the retina but negatively correlated to axon diameter in the nerve (P < 0.001. Conclusion: Intraretinally myelinated axons are larger than non-myelinated axons from the same population and suggests that glial cells can induce diameter changes in retinal axons that are not normally myelinated. This effect is more dramatic on intraretinal axons compared with the normal transition zone as axons enter the optic nerve and these changes are abnormal. Whether intraretinal myelin alters axonal conduction velocity or blocks axonal conduction remains to be clarified and these issues may have different clinical outcomes.

  5. Effect of Orifice Diameter on Bubble Generation Process in Melt Gas Injection to Prepare Aluminum Foams

    Science.gov (United States)

    Yuan, Jianyu; Li, Yanxiang; Wang, Ningzhen; Cheng, Ying; Chen, Xiang

    2016-06-01

    The bubble generation process in conditioned A356 alloy melt through submerged spiry orifices with a wide diameter range (from 0.07 to 1.0 mm) is investigated in order to prepare aluminum foams with fine pores. The gas flow rate and chamber pressure relationship for each orifice is first determined when blowing gas in atmospheric environment. The effects of chamber pressure ( P c) and orifice diameter ( D o) on bubble size are then analyzed separately when blowing gas in melt. A three-dimensional fitting curve is obtained illustrating both the influences of orifice diameter and chamber pressure on bubble size based on the experimental data. It is found that the bubble size has a V-shaped relationship with orifice diameter and chamber pressure neighboring the optimized parameter ( D o = 0.25 mm, P c = 0.4 MPa). The bubble generation mechanism is proposed based on the Rayleigh-Plesset equation. It is found that the bubbles will not be generated until a threshold pressure difference is reached. The threshold pressure difference is dependent on the orifice diameter, which determines the time span of pre-formation stage and bubble growth stage.

  6. Diameter limitation in growth of III-Sb-containing nanowire heterostructures.

    Science.gov (United States)

    Ek, Martin; Borg, B Mattias; Johansson, Jonas; Dick, Kimberly A

    2013-04-23

    The nanowire geometry offers significant advantages for exploiting the potential of III-Sb materials. Strain due to lattice mismatch is efficiently accommodated, and carrier confinement effects can be utilized in tunneling and quantum devices for which the III-Sb materials are of particular interest. It has however proven difficult to grow thin (below a few tens of nanometers), epitaxial III-Sb nanowires, as commonly no growth is observed below some critical diameter. Here we explore the processes limiting the diameter of III-Sb nanowires in a model system, in order to develop procedures to control this effect. The InAs-GaSb heterostructure system was chosen due to its great potential for tunneling devices in future low-power electronics. We find that with increasing growth temperature or precursor partial pressures, the critical diameter for GaSb growth on InAs decreases. To explain this trend we propose a model where the Gibbs-Thomson effect limits the Sb supersaturation in the catalyst particle. This understanding enabled us to further reduce the nanowire diameter down to 32 nm for GaSb grown on 21 nm InAs stems. Finally, we show that growth conditions must be carefully optimized for these small diameters, since radial growth increases for increased precursor partial pressures beyond the critical values required for nucleation.

  7. Effect of Catalytic Layer Thickness on Diameter of Vertically Aligned Individual Carbon Nanotubes

    Directory of Open Access Journals (Sweden)

    Hyun Kyung Jung

    2014-01-01

    Full Text Available The effect of catalytic thin film thickness on the diameter control of individual carbon nanotubes grown by plasma enhanced chemical vapor deposition was investigated. Individual carbon nanotubes were grown on catalytic nanodot arrays, which were fabricated by e-beam lithography and e-beam evaporation. During e-beam evaporation of the nanodot pattern, more catalytic metal was deposited at the edge of the nanodots than the desired catalyst thickness. Because of this phenomenon, carbon atoms diffused faster near the center of the dots than at the edge of the dots. The carbon atoms, which were gathered at the interface between the catalytic nanodot and the diffusion barrier, accumulated near the center of the dot and lifted the catalyst off. From the experiments, an individual carbon nanotube with the same diameter as that of the catalytic nanodot was obtained from a 5 nm thick catalytic nanodot; however, an individual carbon nanotube with a smaller diameter (~40% reduction was obtained from a 50 nm thick nanodot. We found that the thicker the catalytic layer, the greater the reduction in diameter of the carbon nanotubes. The diameter-controlled carbon nanotubes could have applications in bio- and nanomaterial scanning and as a contrast medium for magnetic resonance imaging.

  8. Atomic layer deposition as pore diameter adjustment tool for nanoporous aluminum oxide injection molding masks.

    Science.gov (United States)

    Miikkulainen, Ville; Rasilainen, Tiina; Puukilainen, Esa; Suvanto, Mika; Pakkanen, Tapani A

    2008-05-06

    The wetting properties of polypropylene (PP) surfaces were modified by adjusting the dimensions of the surface nanostructure. The nanostructures were generated by injection molding with nanoporous anodized aluminum oxide (AAO) as the mold insert. Atomic layer deposition (ALD) of molybdenum nitride film was used to control the pore diameters of the AAO inserts. The original 50-nm pore diameter of AAO was adjusted by depositing films of thickness 5, 10, and 15 nm on AAO. Bis(tert-butylimido)-bis(dimethylamido)molybdenum and ammonia were used as precursors in deposition. The resulting pore diameters in the nitride-coated AAO inserts were 40, 30, and 20 nm, respectively. Injection molding of PP was conducted with the coated inserts, as well as with the non-coated insert. Besides the pore diameter, the injection mold temperature was varied with temperatures of 50, 70, and 90 degrees C tested. Water contact angles of PP casts were measured and compared with theoretical contact angles calculated from Wenzel and Cassie-Baxter theories. The highest contact angle, 140 degrees , was observed for PP molded with the AAO mold insert with 30-nm pore diameter. The Cassie-Baxter theory showed better fit than the Wenzel theory to the experimental values. With the optimal AAO mask, the nanofeatures in the molded PP pieces were 100 nm high. In explanation of this finding, it is suggested that some sticking and stretching of the nanofeatures occurs during the molding. Increase in the mold temperature increased the contact angle.

  9. Effects of Coil Diameter in Thickness Measurement Using Pulsed Eddy Current Non-destructive Testing

    Science.gov (United States)

    Nisa Azaman, Khairun; Sophian, Ali; Nafiah, Faris

    2017-11-01

    Non-destructive testing (NDT) techniques are used in industry to evaluate the properties of a material, component or structure without causing any permanent damage. Among the techniques, pulsed eddy current (PEC) NDT is regarded as a new technique where a broadband pulse excitation is used, as opposed to single frequencies employed in conventional eddy current NDT. In this study, a 2D axisymmetric electromagnetic model of a PEC probe has been developed and it has been used to study the effects of the excitation coil diameter on the performance of PEC probes in sample thickness measurement. A PEC system has also been built to validate the model. Aluminium plates are used as the sample and they can be stacked up to replicate thickness from 1 mm to 10 mm. The results show that there is a very good correlation between the simulation and experimental results, with an average error of less than 10%. The results also suggest that the larger the diameter of the excitation coil, the deeper the penetration and therefore the larger the thickness measurement range. It has also been shown that although the larger diameters have deeper penetration, the smallest diameter has the highest sensitivity if normalization is not used. These conclusions indicate that coil diameter is an important parameter in a PEC probe design for thickness measurement applications.

  10. Treatment of refractory vernal ulcers with large-diameter bandage contact lenses.

    Science.gov (United States)

    Quah, Say Aun; Hemmerdinger, Chris; Nicholson, Steven; Kaye, Stephen B

    2006-09-01

    To report two cases of refractory vernal ulcers in which the fitting of a large-diameter (22 mm) hydrogel (Contaflex T75) bandage contact lens (BCL) ameliorated the signs and symptoms of the condition. Two patients with refractory vernal ulcers are described. Mechanisms of the effect of a large-diameter lens across the ocular surface are discussed in this condition. The first patient is a 10-year-old boy who had been treated unsuccessfully for a left vernal corneal ulcer with topical prednisolone 0.5% and olopatadine. The vernal ulcer resolved 2 weeks after the fitting of a large-diameter BCL. The second patient is a 4-year-old boy who had been intolerant of all his previous topical medications partly because of his ocular discomfort in association with the right vernal ulcer. A large-diameter BCL was fitted in his right eye. The BCL was removed 2 weeks later with complete healing of the corneal vernal ulcer. Owing to his improved comfort, the patient was able to tolerate topical prednisolone 0.5% drops. Large-diameter BCLs may be a useful treatment option in the management of refractory vernal ulcers.

  11. Anticipating Cutoff Diameters in Deterministic Lateral Displacement (DLD) Microfluidic Devices for an Optimized Particle Separation.

    Science.gov (United States)

    Pariset, Eloise; Pudda, Catherine; Boizot, François; Verplanck, Nicolas; Berthier, Jean; Thuaire, Aurélie; Agache, Vincent

    2017-10-01

    Deterministic lateral displacement (DLD) devices enable to separate nanometer to micrometer-sized particles around a cutoff diameter, during their transport through a microfluidic channel with slanted rows of pillars. In order to design appropriate DLD geometries for specific separation sizes, robust models are required to anticipate the value of the cutoff diameter. So far, the proposed models result in a single cutoff diameter for a given DLD geometry. This paper shows that the cutoff diameter actually varies along the DLD channel, especially in narrow pillar arrays. Experimental and numerical results reveal that the variation of the cutoff diameter is induced by boundary effects at the channel side walls, called the wall effect. The wall effect generates unexpected particle trajectories that may compromise the separation efficiency. In order to anticipate the wall effect when designing DLD devices, a predictive model is proposed in this work and has been validated experimentally. In addition to the usual geometrical parameters, a new parameter, the number of pillars in the channel cross dimension, is considered in this model to investigate its influence on the particle trajectories. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Germination, seed diameter and pregerminative treatments in species with different purposes of use

    Directory of Open Access Journals (Sweden)

    Ricardo Vinicio Abril-Saltos

    2017-09-01

    Full Text Available The evaluation of vegetal species germination consents to know its characteristics and permits to understand the factors that influence this process. The aim of this research was to know the germination’s characteristics of some species, such as Eugenia stipitata McVaugh, Inga edulis Mart, Inga spectabilis (Vahl Wild, Piptocoma discolor (Kunth Pruski, Stachytarpheta cayennensis (Rich. Vahl, and Verbena officinalis L., and also their reaction to pregerminative treatments depending on the seed’s diameter. This study was carried out in Pastaza, Province of Pastaza, Ecuador, between February and June, 2014. Different diameters of seeds and pregerminative treatments were used in species, which did not present germination percentages higher than 40%. In the first practice I. edulis and I. spectabilis exceeded this value without treatment. Other species had lower values. Seeds were classified considering two diameters and two doses of gibberellin acid, this was applied to, and evaluated in the E. stipitata. In addition, scarification with sulfuric acid was done. After 45 days of its application, 100 ppm of gibberellic acid with larger seed diameter reported higher percentages of germination in S. cayenennsis, and in E. stipitata, which also interacted with the scarification. V. officinalis and P. discolor, did not present any response to the applications made. I. edulis and I. spectabilis presented high germination percentages without pregerminative treatments, E. stipitata and S. cayenennsis showed response to seed diameter and the applied treatments, while P discolor and V. officinalis did not show any response.

  13. Tannins gravimetric yield condensed in Anadenanthera peregrina bark in different diameter classes

    Directory of Open Access Journals (Sweden)

    Caroline Junqueira Sartori

    2014-06-01

    Full Text Available This work aimed to determine the gravimetric yield of condensed tannins in the Anadenanthera peregrina bark in different diameter classes. Fifty-nine trees samples were collected of Anadenanthera peregrina, at 1.30m of the ground (diameter at breast height - DBH, distributed in seven diameter classes. The barks were dried and crushed in mill of hammer. Composite sample was made to prepare the extract. The extraction was done using water in the ratio 15:1 (v/w, added 3% sodium sulfite (w/w in water-bath at 70°C for 4 hours. The material was filtered using fine cloth strainer and concentrated on a heating plate at approximately 150 g. It was determined the extract mass and removed 10 g for obtaining solids content and 20g for the Stiasny's index. The average values of total solids content, Stiasny's index, condensed tannin content and the compound content non-tannin were 11.34%; 75.79%; 12.76% and 4.07%, respectively. The content of solids, Stiasny's index, compound content non-tannin show significant differences between diameter classes. For the condensed tannins production, the diameter class parameter there was no influence.

  14. Axial variation of basic density of Araucaria angustifolia wood in different diameter classes

    Directory of Open Access Journals (Sweden)

    Rômulo Trevisan

    Full Text Available ABSTRACT: The study of the wood characteristics is of fundamental importance for the correct use of this raw material and, among its properties, the basic density is a major, being reference in the quality of this material. This study aimed to evaluate the axial variation of basic density of the wood of Araucaria angustifolia (Bertoloni O. Kuntze in different diameter classes. For this, three trees were selected in six diameter classes, called class 1 (20-30cm, class 2 (30.1-40cm, class 3 (40.1-50cm, class 4 (50.1-60cm, class 5 (60.1-70cm and class 6 (70.1-80cm. From each individual sampled was withdrawn a disc at 0.1m (base, 25, 50, 75 and 100% of the height of the first live branch and in the diameter at 1.30m from the ground (DBH, which were used for determining basic density. The weighted average basic density was equal to 0.422g cm-3 and, regardless of the diameter class analyzed, this property decreased in the axial direction. Diameter induced variation of basic density, but has not been verified a positive or negative systematic tendency in relation to the sampled interval.

  15. Study of helical flow inducers with different thread pitches and diameters in vena cava

    Science.gov (United States)

    Deng, Xiaoyan; Shan, Xinying; Xing, Yubin

    2018-01-01

    Pulmonary embolism is a severe, potentially life-threatening condition. Inferior vena cava filters have been used to prevent recurrent pulmonary embolisms. However, the build-up of thrombosis in vena cava filters after deployment presents a severe problem to patients. Previous studies proposed that filters with helical flow are beneficial and capable of alleviating this problem. In this study, the hemodynamic performances of four typical helical flow inducers in the vena cava are determined using computational fluid dynamics simulations (steady-state and pulsatile flow) and compared. Pilot in vitro experiments were also conducted. The simulation results demonstrate that large-diameter inducers produce helical flow. Among inducers with identical diameter, those with a smaller thread pitch are more likely to induce increased helical flow. We also observed that the small thread pitch inducers can yield higher shear rates. Furthermore, a large diameter, small thread pitch helical flow inducer increases the time-averaged wall shear stress and reduces the oscillating shear index and relative residence time on the vessel wall in the vicinity of the helical flow inducer. In vitro experiments also verify that large diameter inducers generate a helical flow. A notable observation of this study is that the diameter is the key parameter that affects the induction of a helical flow. This study will likely provide important guidance for the design of interventional treatments and the deployment of filters associated with helical flow in the vena cava. PMID:29298357

  16. An Experimental and Numerical Study on Embedded Rebar Diameter in Concrete Using Ground Penetrating Radar

    Directory of Open Access Journals (Sweden)

    Md Istiaque Hasan

    2016-01-01

    Full Text Available High frequency ground penetrating radar (GPR has been widely used to detect and locate rebars in concrete. In this paper, a method of estimating the diameter of steel rebars in concrete with GPR is investigated. The relationship between the maximum normalized positive GPR amplitude from embedded rebars and the rebar diameter was established. Concrete samples with rebars of different diameters were cast and the maximum normalized amplitudes were recorded using a 2.6 GHz GPR antenna. Numerical models using GPRMAX software were developed and verified with the experimental data. The numerical models were then used to investigate the effect of dielectric constant of concrete and concrete cover on the maximum normalized amplitude. The results showed that there is an approximate linear relationship between the rebar diameter and the maximum GPR normalized amplitude. The developed models can be conveniently used to estimate the embedded rebar diameters in existing concrete with GPR scanning; if the concrete is homogeneous, the cover depth is known and the concrete dielectric constant is also known. The models will be highly beneficial in forensic investigations of existing concrete structures with unknown rebar sizes and locations.

  17. Inferior vena cava diameter change after intravenous furosemide in patients diagnosed with acute decompensated heart failure.

    Science.gov (United States)

    Tchernodrinski, Stefan; Lucas, Brian P; Athavale, Ambarish; Candotti, Carolina; Margeta, Bosko; Katz, Ariel; Kumapley, Rudolf

    2015-03-01

    Measurement of the inferior vena cava (IVC) diameters may improve decision-making for patients hospitalized with acute decompensated heart failure. Nevertheless, little is known about how the IVC is affected by loop diuretics. We sought to determine if bolus infusions of intravenous furosemide affect IVC diameters measured by hand-carried ultrasonography. We conducted a prospective cohort study at a public teaching hospital from September 2009 through June 2010. Physician investigators performed IVC ultrasonography on a convenience sample of 70 hospitalized adults who were prescribed intravenous furosemide for the diagnosis of acute decompensated heart failure. Participants' median baseline IVC diameter was 2.38 cm (interquartile range, 1.91-2.55 cm). At 1-2 hours after furosemide, IVC diameters decreased an average of 0.21 cm (95% CI, 0.13-0.29 cm) and remained significantly below baseline at 2-3 hours after furosemide by an average of 0.15 cm (95% CI, 0.07-0.22 cm). IVC diameters of adults diagnosed with acute decompensated heart failure become measurably smaller after single doses of intravenous furosemide. Whether this represents a true change in volume status has not been studied. © 2014 Wiley Periodicals, Inc.

  18. Diameter deviation calculation for UO{sub 2} kernel by sol-gel process

    Energy Technology Data Exchange (ETDEWEB)

    Guo Wenli; Xing Juan [Beijing Key Lab of Fine Ceramics, Institution of Nuclear and New Energy Technology, Tsinghua University, Beijing 10084 (China); Liang, T.X., E-mail: txliang@tsinghua.edu.cn [Beijing Key Lab of Fine Ceramics, Institution of Nuclear and New Energy Technology, Tsinghua University, Beijing 10084 (China); Jin Xin [CNNC China Nuclear Power Engineering Co. Ltd., Beijing 100840 (China)

    2011-08-15

    Highlights: > UO{sub 2} kernels are produced by a sol-gel method. > The formula about jet velocity, solution level and gas pressure on solution was established. > The decline of solution level leads to the decreasing of jet velocity and the solution mass flow rate, as a result, the diameter deviation increased. > After compensating the pressure on the liquid gradually during the casting process, the standard deviation of kernel diameter was less than 12 {mu}m. - Abstract: UO{sub 2} kernels for HTR (High Temperature Gas-cooled Reactor) fuel element are produced using a sol-gel method. The size of UO{sub 2} kernels was controlled strictly by minimizing the dispersion of the UO{sub 2} kernel diameter during the casting process. A relationship between the filling gas tank pressure and solution level in the tank was developed to keep a constant solution mass flow rate in the nozzles. Based on equation of flow energy conservation, a formula about jet velocity, solution level and gas tank pressure on solution was established. Using the formula, the minimum pressure and maximum pressure were calculated. During the casting process, the decline of solution level will lead to the decreasing of jet velocity and the solution mass flow rate that can cause the increasing of diameter deviation. By compensating the pressure on the liquid gradually during the casting process, the flow fluency was kept in an acceptable range stably, the standard deviation of kernel diameter was less than 12 {mu}m.

  19. The space instrument SODISM, a telescope to measure the solar diameter

    Science.gov (United States)

    Meftah, M.; Irbah, A.

    2011-09-01

    PICARD is a satellite dedicated to the simultaneous measurement of the solar diameter, the solar shape, the solar irradiance and the solar interior. These measurements obtained throughout the mission will allow study of their variations as a function of solar activity. The objectives of the PICARD mission are to improve our knowledge of the functioning of our star through new observations and the influence of the solar activity on the climate of the Earth. PICARD was launched on June 15, 2010 on a Dnepr-1 launcher. SODISM (SOlar Diameter Imager and Surface Mapper), an instrument of the PICARD payload, is a high resolution imaging telescope. It was built on an innovative technological concept. SODISM allows us to measure the solar diameter and shape with an accuracy of a few milliarcseconds, and to perform helioseismologic observations to probe the solar interior. SODISM provides continuous observations of the Sun since mid-July 2010. A brief comparison of measurements of solar diameter since the seventeenth century and solar diameter variability are described. In this article, we present the instrumental concept and design and we give an overview of the thermal stability of the telescope. First results from the SODISM experiment are briefly reported (housekeeping and image).

  20. Wind tunnel test of a variable-diameter tiltrotor (VDTR) model

    Science.gov (United States)

    Matuska, David; Dale, Allen; Lorber, Peter

    1994-01-01

    This report documents the results from a wind tunnel test of a 1/6th scale Variable Diameter Tiltrotor (VDTR). This test was a joint effort of NASA Ames and Sikorsky Aircraft. The objective was to evaluate the aeroelastic and performance characteristics of the VDTR in conversion, hover, and cruise. The rotor diameter and nacelle angle of the model were remotely changed to represent tiltrotor operating conditions. Data is presented showing the propulsive force required in conversion, blade loads, angle of attack stability and simulated gust response, and hover and cruise performance. This test represents the first wind tunnel test of a variable diameter rotor applied to a tiltrotor concept. The results confirm some of the potential advantages of the VDTR and establish the variable diameter rotor a viable candidate for an advanced tiltrotor. This wind tunnel test successfully demonstrated the feasibility of the Variable Diameter rotor for tilt rotor aircraft. A wide range of test points were taken in hover, conversion, and cruise modes. The concept was shown to have a number of advantages over conventional tiltrotors such as reduced hover downwash with lower disk loading and significantly reduced longitudinal gust response in cruise. In the conversion regime, a high propulsive force was demonstrated for sustained flight with acceptable blade loads. The VDTR demonstrated excellent gust response capabilities. The horizontal gust response correlated well with predictions revealing only half the response to turbulence of the conventional civil tiltrotor.

  1. PHOS Experiment: Thermal Response of a Large Diameter Pulsating Heat Pipe on Board REXUS-18 Rocket

    Science.gov (United States)

    Creatini, F.; Guidi, G. M.; Belfi, F.; Cicero, G.; Fioriti, D.; Di Prizio, D.; Piacquadio, S.; Becatti, G.; Orlandini, G.; Frigerio, A.; Fontanesi, S.; Nannipieri, P.; Rognini, M.; Morganti, N.; Filippeschi, S.; Di Marco, P.; Fanucci, L.; Baronti, F.; Mameli, M.; Marengo, M.; Manzoni, M.

    2015-09-01

    In the present work, the results of two Closed Loop Pulsating Heat Pipes (CLPHPs) tested on board REXUS-1 8 sounding rocket in order to get experimental data over a relatively broad reduced gravity period (about 90 s) are thoroughly discussed. The CLPHPs are partially filled with refrigerant FC-72 and have, respectively, an inner tube diameter larger (3 .0 mm) and slightly smaller (1 .6 mm) than a critical diameter defined on Earth gravity conditions. On ground, the small diameter CLPHP works as a real Pulsating Heat Pipe (PHP): the typical capillary slug flow pattern forms inside the device and the heat exchange is triggered by self-sustained thermally driven oscillations of the working fluid. Conversely, the large diameter CLPHP behaves like a two-phase thermosyphon in vertical position while does not operate in horizontal position as the working fluid stratifies within the tube and surface tension is not able to balance buoyancy. Then, the idea to test the CLPHPs under reduced gravity conditions: as soon as gravity reduces, buoyancy becomes less intense and the typical capillary slug flow pattern can also forms within a tube with a larger diameter. Moreover, this allows to increase the heat transfer rate and, consequently, to decrease the overall thermal resistance. Even though it was not possible to experience the expected reduced gravity conditions due to a failure of the yo-yo de-spin system, the thermal response to the peculiar acceleration field (hyper-gravity) experienced on board are thoroughly described.

  2. Relationship of vocal cord paralysis to the coil diameter of vagus nerve stimulator leads.

    Science.gov (United States)

    Robinson, Leslie C; Winston, Ken R

    2015-03-01

    This investigation was done to examine, following implantation of vagus nerve stimulators, the relationship of vocal cord paralysis to the inner diameter of the coils used to attach the stimulator lead to the nerve. All data in this investigation were collected, as mandated by the FDA, by the manufacturer of vagus nerve stimulators and were made available without restrictions for analysis by the authors. The data reflect all initial device implantations in the United States for the period from 1997 through 2012. Vocal cord paralysis was reported in 193 of 51,882 implantations. In patients aged 18 years and older, the incidence of paralysis was 0.26% when the stimulator leads had coil diameters of 3 mm and 0.51% when the leads had 2-mm-diameter coils (p vagus nerve stimulator leads having 2-mm-diameter coils than with leads having 3-mm-diameter coils. The incidence of vocal cord paralysis increases with patient age at implantation.

  3. Effects of the handle diameter and tip angle of chopsticks on the food-serving performance of male subjects.

    Science.gov (United States)

    Wu, S P

    1995-12-01

    The effects of chopsticks handle diameter and tip angle on the food-serving performance of pinching food, pulling food, shearing food and thrusting food, were investigated in this study. A total of 24 male subjects was tested using 12 pairs of experimental chopsticks, consisting of three types of different handle diameters and four types of different tip angles. These results indicated that chopstick handle diameter and tip angle have a significant influence on eating efficiency, and that these two variables have a significant interaction. In addition, chopstick tip diameter also had significant effects on performance at the four tasks and subjective ratings. Generally, according to the results, when the chopsticks design is presented in terms of handle diameter, tip angle and tip diameter, a pair of chopsticks with 6 mm handle diameter x 2 degrees tip angle x 4 mm tip diameter would be optimum.

  4. Puffing and inhalation behaviour in cigarette smoking: Implications for particle diameter and dose

    Science.gov (United States)

    Dickens, Colin; McGrath, Conor; Warren, Nigel; Biggs, Philip; McAughey, John

    2009-02-01

    Inhalation of tobacco smoke aerosol is a two-step process involving puffing followed by inhalation. Measured smoke deposition efficiencies in the lung (20-70%) are greater than expected for smoke particles of diameter 150 -- 250 nm CMD. Various mechanisms have been put forward to explain this enhanced deposition pattern, including coagulation, hygroscopic growth, condensation and evaporation, changes in composition, or changes in inhalation behaviour. This paper represents one of a series of studies seeking to better quantify smoke chemistry, inhalation behaviour and cumulative particle growth. The studies have been conducted to better understand smoke dosimetry and links to disease as part of a wider programme defining risk and potential harm reduction. In this study, it was noted that particle deposition increased with increasing inhalation depth, and that smoke inhalation volumes were generally greater than normal tidal breathing volumes. A weak association was observed between particle diameter and puff flow, but no strong association between particle diameter and retention efficiency.

  5. Numerical Modelling of Large-Diameter Steel Piles at Horns Rev

    DEFF Research Database (Denmark)

    Augustesen, Anders Hust; Brødbæk, K. T.; Møller, M.

    2009-01-01

    Today large-diameter monopiles are the most common foundation type used for large offshore wind farms. This paper aims to investigate the behaviour of monopiles under monotonic loading taking the interaction between the pile and the subsoil into account. Focus is paid to a monopile used as founda......Today large-diameter monopiles are the most common foundation type used for large offshore wind farms. This paper aims to investigate the behaviour of monopiles under monotonic loading taking the interaction between the pile and the subsoil into account. Focus is paid to a monopile used...... as foundation for a wind turbine at Horns Rev located in the Danish sector of the North Sea. The outer diameter of the pile is 4 m and the subsoil at the location consists primarily of sand. The behaviour of the pile is investigated under realistic loading conditions by means of a traditional Winkler...

  6. Patch test responses to rockwool of different diameters evaluated by cutaneous blood flow measurement.

    Science.gov (United States)

    Eun, H C; Lee, H G; Paik, N W

    1991-04-01

    Rockwool is a man-made mineral fiber used mainly for insulation, which can cause mechanical skin irritation. This study was performed to evaluate the irritant potential of rockwools of different diameters and to compare the change of blood flow, measured by laser Doppler flowmetry, at different patch test occlusion times with rockwools. Rockwool A (mean diameter 4.20 +/- 1.96 mu) was more irritating than rockwool B (mean diameter 3.20 +/- 1.5 mu). The difference was more clearly observed in a 48-h patch test than in an 8-h or 24-h test. We concluded that laser Doppler blood flow measurement was a useful experimental tool for the evaluation of irritant patch test responses to mechanical irritants like rockwool, and that 48 h or more of occlusion time was necessary to produce irritant patch test responses to certain types of rockwool.

  7. Electrospray ionization from nanopipette emitters with tip diameters of less than 100 nm.

    Science.gov (United States)

    Yuill, Elizabeth M; Sa, Niya; Ray, Steven J; Hieftje, Gary M; Baker, Lane A

    2013-09-17

    Work presented here demonstrates application of nanopipettes pulled to orifice diameters of less than 100 nm as electrospray ionization emitters for mass spectrometry. Mass spectrometric analysis of a series of peptides and proteins electrosprayed from pulled-quartz capillary nanopipette emitters with internal diameters ranging from 37 to 70 nm is detailed. Overall, the use of nanopipette emitters causes a shift toward the production of ions of higher charge states and leads to a reduction in width of charge-state distribution as compared to typical nanospray conditions. Further, nanopipettes show improved S/N and the same signal precision as typical nanospray, despite the much smaller dimensions. As characterized by SEM images acquired before and after spray, nanopipettes are shown to be robust under conditions employed. Analytical calculations and numerical simulations are used to calculate the electric field at the emitter tip, which can be significant for the small diameter tips used.

  8. Effect of age and diameter class on the properties of wood from clonal Eucalyptus

    Directory of Open Access Journals (Sweden)

    Wilma Michele Santos Santana

    2012-03-01

    Full Text Available The objective of this work was to evaluate the influence of age and diameter class on the physical, thermal and chemical characteristics of a clone of Eucalyptus grandis and Eucalyptus urophylla. The material originated from a reforestation site owned by GERDAU S.A. and included trees at age 34, 48, 61, 74 and 86 months. Two trees were selected per age in each diameter class, observing the proportion of each established plot. Analyses of physical characteristics included wood basic density, dry matter weight and carbon stock, and of chemical characteristics included holocellulose, total extractives content, total lignin and ash content, in addition to elemental and thermal analysis of the wood. Results led to the conclusion that most wood properties were influenced by age and diameter class. The species was found to have great potential for production of biomass and generation of heat energy, potentially convertible into mechanical energy and electricity.

  9. BIOMASS ESTIMATION OF INDIVIDUAL TREES USING STEM AND CROWN DIAMETER TLS MEASUREMENTS

    Directory of Open Access Journals (Sweden)

    M. Holopainen

    2012-09-01

    Full Text Available The objective of this study was to make preliminary investigations between accurately measured field biomasses and terrestrial laser scanning (TLS measurements including tree crown and stem diameters. Stem and crown biomass were determined based on detailed field measurements of the individual tree stem, bark, branch and needles. At the tree level, field measurements were intensive and thus material consisted of only 20 trees located at 11 stands. Stem and crown diameters were extracted manually from TLS point clouds and used as predictors for total biomass. Correlations from 0.96 to 0.99 between predicted and field measured biomass estimates were obtained. Examination of stem form predictions showed that various diameters measured by TLS could enhance the tree level stem curve predictions. Results are rather promising, but more field data is needed for developing practical modelling means. Our further studies will concentrate on automation of TLS data processing and use the of TLS features in the biomass estimation.

  10. Application of the Critical Heat Flux Look-Up Table to Large Diameter Tubes

    Directory of Open Access Journals (Sweden)

    M. El Nakla

    2013-01-01

    Full Text Available The critical heat flux look-up table was applied to a large diameter tube, namely 67 mm inside diameter tube, to predict the occurrence of the phenomenon for both vertical and horizontal uniformly heated tubes. Water was considered as coolant. For the vertical tube, a diameter correction factor was directly applied to the 1995 critical heat flux look-up table. To predict the occurrence of critical heat flux in horizontal tube, an extra correction factor to account for flow stratification was applied. Both derived tables were used to predict the effect of high heat flux and tube blockage on critical heat flux occurrence in boiler tubes. Moreover, the horizontal tube look-up table was used to predict the safety limits of the operation of boiler for 50% allowable heat flux.

  11. Age variance of left ventricular diameters in dogs with cardiac disease.

    Science.gov (United States)

    Kerkhof, P L; Roos, A; ter Haar, G; Kocsis, S; Pijnenburg, H L; Stokhof, A A

    1998-01-01

    Ventricular size increases during growth, but often due to cardiac disease. This study aims to describe left ventricular dimension interrelations using a representation that is applicable to patients with cardiac disease, and subsequently to statistically study possible age and gender influences in a large population. In retrospect we analyzed echocardiographically obtained diameters of the left ventricle in 442 dogs of various breeds with congenital or acquired heart disease. Also, we compared our findings with published data on humans and other animals. Multivariate regression analysis was applied to assess possible influences of age and gender. A high correlation was found for end-systolic diameter (ESD) versus end-diastolic diameter (EDD): ESD (cm) = -1.01 cm + 0.93 x EDD (cm) with r = 0.94, p framework for studies on cardiac volume regulation and performance in the cardiopathological spectrum, while permitting incorporation of modulating effects related to age.

  12. Effect of Rotor Diameter on the Thermal Stresses of a Turbine Rotor Model

    Science.gov (United States)

    Dávalos, J. O.; García, J. C.; Urquiza, G.; Castro-Gómez, L. L.; Rodríguez, J. A.; De Santiago, O.

    2016-04-01

    Thermal stresses in a simplified steam turbine rotor model during a cold startup are analyzed using finite element analysis (FEA). In order to validate the numerical model, an experimental array is developed in which a hollow cylinder is heated with hot air in the external surface. At the thick wall of the cylinder, temperature distribution is measured in real time, while at the same time an algorithm computes thermal stresses. Additional computational fluid dynamics (CFD) calculations are made to obtain magnitudes of velocity and pressure in order to compute convective heat transfer coefficient. The experimental results show good agreement with the FEA computations. To evaluate the effect of rotor diameter size, FEA computations with variation in external and internal diameters are performed. Results show that thermal stresses are proportional to rotor diameter size. Also, zones of higher stress concentration are found in the external and internal surfaces of the rotor.

  13. The blood pressure-induced diameter response of retinal arterioles decreases with increasing diabetic maculopathy

    DEFF Research Database (Denmark)

    Frederiksen, Christian Alcaraz; Jeppesen, Peter; Knudsen, Søren Tang

    2006-01-01

    BACKGROUND: The aim of the study was to compare the diameter response of retinal arterioles and retinal thickness in patients with different stages of diabetic maculopathy during an increase in the arterial blood pressure. METHODS: Four groups each consisting of 19 individuals were studied. Group...... A consisted of normal individuals and groups B-D consisted of type 2 diabetic patients matched for diabetes duration, age, and gender, and characterized by: Group B no retinopathy, Group C mild retinopathy, Group D maculopathy not requiring laser treatment. The diameter changes of a large retinal arteriole...... isometric exercise in normal persons (diameter response: -0.70+/-0.48%) and in patients with no retinopathy (-1.15+/-0.44%), but dilated in patients with mild retinopathy (0.41+/-0.49%) and diabetic maculopathy (0.54+/-0.44%), p=0.01. Retinal thickness was normal in Group A (260+/-5.0 microm), Group B (257...

  14. Effects of hunger level and tube diameter on thefeeding behavior of teat-fed dairy calves

    DEFF Research Database (Denmark)

    Herskin, Mette S; Skjøth, Flemming; Jensen, Margit Bak

    2010-01-01

    a 40-min period after morning milk feeding on d 7, 9, and 11 of testing is reported. No significant interactions between tube diameter and hunger level on behavior were found. Reduced tube diameter led to increased latency to empty the teat bucket, increased duration of nutritive sucking, and decreased......Behavioral changes caused by variation in hunger have a great potential in health monitoring in dairy cattle. The present experiment used 48 Danish Holstein bull calves with a median age of 33 d. We examined the effect of different levels of hunger (reduced, in which calves were fed 1.5 L of milk...... via esophageal tube before feeding; increased, in which calves were fed half milk ration at the previous feeding, or control, in which calves were fed normal ration at the previous feeding) on feeding behavior of calves fed via different tube diameters (6.0, 3.0, or 1.5 mm). Behavior observed during...

  15. Effect of fiber blending ratios of cotton/polyester yarns on retained splice diameter

    Science.gov (United States)

    Çelik, H. İ.; Kaynak, H. K.

    2017-10-01

    The most important performance parameters of splicing are obtaining adequate strength and appearance at the splice point for all processing requirements. The diameter of spliced portion effects not only appearance of the splice joints but also physical characteristics such as packing density, strength, specific volume of the yarn. In this study, the effect of cotton/polyester fiber blend ratios on spliced portion diameter at different slicing air pressures was investigated. For this aim, three yarn samples 100% cotton, 80-20% CO-PES and 50- 50% CO-PES were produced with 40/1 Ne. Each yarn samples was spliced at three different pressures; 4 bar, 5 bar and 6 bar. The diameters of spliced portion and retained yarns were measured by using ImageJ program and the results were analyzed statistically.

  16. High-performance radio frequency transistors based on diameter-separated semiconducting carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Cao, Yu; Che, Yuchi; Zhou, Chongwu, E-mail: chongwuz@usc.edu [Department of Electrical Engineering, University of Southern California, Los Angeles, California 90089 (United States); Seo, Jung-Woo T.; Hersam, Mark C. [Department of Materials Science and Engineering and Department of Chemistry, Northwestern University, Evanston, Illinois 60208 (United States); Gui, Hui [Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, California 90089 (United States)

    2016-06-06

    In this paper, we report the high-performance radio-frequency transistors based on the single-walled semiconducting carbon nanotubes with a refined average diameter of ∼1.6 nm. These diameter-separated carbon nanotube transistors show excellent transconductance of 55 μS/μm and desirable drain current saturation with an output resistance of ∼100 KΩ μm. An exceptional radio-frequency performance is also achieved with current gain and power gain cut-off frequencies of 23 GHz and 20 GHz (extrinsic) and 65 GHz and 35 GHz (intrinsic), respectively. These radio-frequency metrics are among the highest reported for the carbon nanotube thin-film transistors. This study provides demonstration of radio frequency transistors based on carbon nanotubes with tailored diameter distributions, which will guide the future application of carbon nanotubes in radio-frequency electronics.

  17. Electroless reductions on carbon nanotubes: How critical is the diameter of a nanotube

    KAUST Repository

    Guo, Yong

    2013-01-01

    Detailed experimental and theoretical studies have been performed to investigate the influence of the diameter of multi-walled carboxy-functionalized carbon nanotubes (CFCNTs) on their ability to reduce PdCl4 2- salt to Pd nanoparticles on their surface at room temperature. The obtained results (inductively-coupled plasmaspectrometry and cyclic voltammetry) show that the reduction ability of CFCNTs with 5 nm diameter (CFCNT5) is stronger than that of CFCNTs with 15 nm diameter (CFCNT15). Density Functional Theory (DFT) calculations suggest that a more negative charge distribution exists on CFCNT5, which makes it a better electron donor to PdCl42-. This journal is © The Royal Society of Chemistry.

  18. Puffing and inhalation behaviour in cigarette smoking: Implications for particle diameter and dose

    Energy Technology Data Exchange (ETDEWEB)

    Dickens, Colin; McGrath, Conor; Warren, Nigel; Biggs, Philip; McAughey, John, E-mail: colin_dickens@bat.co [British American Tobacco, Group R and D Centre, Southampton, SO15 8TL (United Kingdom)

    2009-02-01

    Inhalation of tobacco smoke aerosol is a two-step process involving puffing followed by inhalation. Measured smoke deposition efficiencies in the lung (20-70%) are greater than expected for smoke particles of diameter 150 - 250 nm CMD. Various mechanisms have been put forward to explain this enhanced deposition pattern, including coagulation, hygroscopic growth, condensation and evaporation, changes in composition, or changes in inhalation behaviour. This paper represents one of a series of studies seeking to better quantify smoke chemistry, inhalation behaviour and cumulative particle growth. The studies have been conducted to better understand smoke dosimetry and links to disease as part of a wider programme defining risk and potential harm reduction. In this study, it was noted that particle deposition increased with increasing inhalation depth, and that smoke inhalation volumes were generally greater than normal tidal breathing volumes. A weak association was observed between particle diameter and puff flow, but no strong association between particle diameter and retention efficiency.

  19. Orientationally invariant indices of axon diameter and density from diffusion MRI

    DEFF Research Database (Denmark)

    Alexander, Daniel C; Hubbard, Penny L; Hall, Matt G

    2010-01-01

    greater diffusivity and lower gradient strength limit sensitivity to only the largest axons. Maps of axon diameter and density indices from the monkey and human data in the corpus callosum and corticospinal tract reflect known trends from histology. The results show orientationally invariant sensitivity......This paper proposes and tests a technique for imaging orientationally invariant indices of axon diameter and density in white matter using diffusion magnetic resonance imaging. Such indices potentially provide more specific markers of white matter microstructure than standard indices from diffusion...... to natural axon diameter distributions for the first time with both specialist and clinical hardware. This demonstration motivates further refinement, validation, and evaluation of the precise nature of the indices and the influence of potential confounds....

  20. Replacement of a molar with two narrow-diameter dental implants

    Directory of Open Access Journals (Sweden)

    Rajeshwari Penmetsa

    2016-01-01

    Full Text Available Dental implants have demonstrated a high degree of success in the restorations of teeth in partially or completely edentulous patients. However, when the buccolingual width of the edentulous crest is insufficient for the placement of standard sized implants, the use of two or more smaller diameter implants should be considered to avoid the need for invasive reconstruction techniques such as grafting procedures. The present case report describes the replacement of a single mandibular first molar with two narrow-diameter implants, in a 41-year- old male patient. No postoperative complications were reported in the 3-year follow-up period. The placement of two narrow-diameter implants replacing a missing mandibular molar could eliminate the mesiodistal bending, double the support capacity in the buccolingual direction, and minimize stress on the implants.

  1. Influence of apical constriction diameter on Root ZX apex locator precision.

    Science.gov (United States)

    Herrera, Manuela; Abalos, Camilo; Planas, Amparo Jimenez; Llamas, Rafael

    2007-08-01

    Small-diameter hand files are systematically used to determine the initial working length and to establish patency of the root canal. In wide canals, electronic apex locator accuracy might be influenced by file size. This article reports on a study to assess the influence of apical constriction diameter on the precision of the Root ZX apex locator by using files of varying diameter on teeth with 3 different degrees of apical widening: 0.37, 0.62, and 1.02 mm. Ten extracted single-root teeth, stored in saline solution at 37 degrees C, were sectioned at the enamel-cement junction and embedded in an alginate mold. Initial working length (L0) was determined with a #10 Kerr file, and canals were irrigated with either 50% citric acid or 5.25% sodium hypochlorite. To assess the ability of the locator to identify the narrowest area of the root canal as constriction diameter increased, the canal was progressively widened by insertion of files of increasing diameter (10-100) at a point L0+1 mm. After each enlargement, the working length (L) was redetermined, with files from #10 (L10) up to the file used for widening. Comparison of statistical results was based on the difference between final working length and initial length (L10) for each apical width. Statistical analysis was carried out with analysis of variance test for comparison of means. Results showed that at apical constriction widths of 0.37 and 0.62 mm, there was no significant difference between initial working lengths as determined by a Kerr #10 file and final working lengths after widening with files of up to #60. In those teeth whose apical width had been increased to 1.02 mm, there was no statistically significant difference between initial and final working lengths as measured by files from #10-#25; however, significant differences were apparent between #10 and #30, #35, or #40 (Papical constriction diameter.

  2. Central cholinergic pathway involvement in the regulation of pupil diameter, blink rate and cognitive function.

    Science.gov (United States)

    Naicker, Preshanta; Anoopkumar-Dukie, Shailendra; Grant, Gary D; Neumann, David L; Kavanagh, Justin J

    2016-10-15

    Anticholinergic medications can exert their effects by acting on muscarinic receptors, which mediates the function of acetylcholine in the central nervous system. Acetylcholine plays a number of roles, particularly in regard to the control of muscle activity and normal cognitive functioning. Eighteen subjects were recruited into the human, double-blind, placebo-controlled, four-way crossover study. Pupil diameter and blink rate were assessed at rest while eye tracking technology recorded eye characteristics. Thereafter a cognitive task was performed, where pupil size and blink rate were once again measured. Assessments were performed pre-ingestion, 0.5h and 2h following the ingestion of a strong centrally acting anticholinergic (promethazine hydrochloride), a moderate centrally acting anticholinergic (hyoscine hydrobromide), an anticholinergic devoid of central effects (hyoscine butylbromide) and placebo. At rest, hyoscine hydrobromide was the only medication to increase pupil diameter and no drug intervention influenced blink rate. During performance of the cognitive task, hyoscine hydrobromide increased pupil diameter and promethazine increased blink rate. Promethazine was the only medication to influence the modified attention network test (ANT) by increasing the conflict effect and grand mean reaction time (RT). Pupil diameter and blink rate were both influenced by the central anticholinergics during performance of the cognitive test, thus highlighting the importance of central cholinergic pathways in the control of pupil diameter and blink rate. The collective effects of central anticholinergics on the modified ANT and on pupil diameter and blink rate during its performance, conveys the importance of central cholinergic pathways in cognitive function. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

  3. Hyaluronic acid enhancement of expanded polytetrafluoroethylene for small diameter vascular grafts

    Science.gov (United States)

    Lewis, Nicole R.

    Cardiovascular disease is the leading cause of mortality and morbidity in the United States and other developed countries. In the United States alone, 8 million people are diagnosed with peripheral arterial disease per year and over 250,000 patients have coronary bypass surgery each year. Autologous blood vessels are the standard graft used in small diameter (<6mm) arterial bypass procedures. Synthetic small diameter grafts have had limited success. While polyethylene (Dacron) and expanded polytetrafluoroethylene (ePTFE) are the most commonly used small diameter synthetic vascular graft materials, there are significant limitations that make these materials unfavorable for use in the low blood flow conditions of the small diameter arteries. Specifically, Dacron and ePTFE grafts display failure due to early thrombosis or late intimal hyperplasia. With the shortage of tissue donors and the limited supply of autologous blood vessels available, there is a need for a small diameter synthetic vascular graft alternative. The aim of this research is to create and characterize ePTFE grafts prepared with hyaluronic acid (HA), evaluate thrombogenic potential of ePTFE-HA grafts, and evaluate graft mechanical properties and coating durability. The results in this work indicate the successful production of ePTFE-HA materials using a solvent infiltration technique. Surface interactions with blood show increased platelet adhesion on HA-modified surfaces, though evidence may suggest less platelet activation and erythrocyte lysis. Significant changes in mechanical properties of HA-modified ePTFE materials were observed. Further investigation into solvent selection, uniformity of HA, endothelialization, and dynamic flow testing would be beneficial in the evaluation of these materials for use in small diameter vascular graft bypass procedures.

  4. Pharyngeal diameter in various head and neck positions during exercise in sport horses

    Science.gov (United States)

    2014-01-01

    Background In equine athletes, dynamic stenotic disorders of the upper airways are often the cause for abnormal respiratory noises and/or poor performance. There are hypotheses, that head and neck flexion may influence the morphology and function of the upper airway and thus could even induce or deteriorate disorders of the upper respiratory tract. Especially the pharynx, without osseous or cartilaginous support is prone to changes in pressure and airflow during exercise. The objective of this study was to develop a method for measuring the pharyngeal diameter in horses during exercise, in order to analyse whether a change of head-neck position may have an impact on the pharyngeal diameter. Results Under the assumption that the width of the epiglottis remains constant in healthy horses, the newly developed method for calculating the pharyngeal diameter in horses during exercise is unsusceptible against changes of the viewing-angle and distance between the endoscope and the structures, which are to be assessed. The quotient of the width of the epiglottis and the perpendicular from a fixed point on the dorsal pharynx to the epiglottis could be used to determine the pharyngeal diameter. The percentage change of this quotient (pharynx-epiglottis-ratio; PE-ratio) in the unrestrained head-neck position against the reference position was significantly larger than that of any other combination of the head-neck positions investigated. A relation between the percentage change in PE-ratio and the degree of head and neck flexion could not be confirmed. Conclusions It could be shown, that the pharyngeal diameter is reduced through the contact position implemented by the rider in comparison to the unrestrained head and neck position. An alteration of the pharyngeal diameter depending on the degree of head and neck flexion (represented by ground and withers angle) could not be confirmed. PMID:24886465

  5. Genome-wide linkage analysis of carotid artery lumen diameter: the strong heart family study.

    Science.gov (United States)

    Bella, Jonathan N; Cole, Shelley A; Laston, Sandy; Almasy, Laura; Comuzzie, Anthony; Lee, Elisa T; Best, Lyle G; Fabsitz, Richard R; Howard, Barbara V; Maccluer, Jean W; Roman, Mary J; Devereux, Richard B; Göring, Harald H H

    2013-10-09

    A significant proportion of the variability in carotid artery lumen diameter is attributable to genetic factors. Carotid ultrasonography and genotyping were performed in the 3300 American Indian participants in the Strong Heart Family Study (SHFS) to identify chromosomal regions harboring novel genes associated with inter-individual variation in carotid artery lumen diameter. Genome-wide linkage analysis was conducted using standard variance component linkage methods, implemented in SOLAR, based on multipoint identity-by-descent matrices. Genome-wide linkage analysis revealed a significant evidence for linkage for a locus for left carotid artery diastolic and systolic lumen diameters in Arizona SHFS participants on chromosome 7 at 120 cM (lod = 4.85 and 3.77, respectively, after sex and age adjustment, and lod = 3.12 and 2.72, respectively, after adjustment for sex, age, height, weight, systolic and diastolic blood pressure, diabetes mellitus and current smoking). Other regions with suggestive evidence of linkage for left carotid artery diastolic and systolic lumen diameter were found on chromosome 12 at 153 cM (lod = 2.20 and 2.60, respectively, after sex and age adjustment, and lod = 2.44 and 2.16, respectively, after full covariate adjustment) in Oklahoma SHFS participants; suggestive linkage for right carotid artery diastolic and systolic lumen diameter was found on chromosome 9 at 154 cM (lod = 2.72 and 3.19, respectively after sex and age adjustment, and lod = 2.36 and 2.21, respectively, after full covariate adjustment) in Oklahoma SHFS participants. We found significant evidence for loci influencing carotid artery lumen diameter on chromosome 7q and suggestive linkage on chromosomes 12q and 9q. © 2013. Published by Elsevier Ireland Ltd. All rights reserved.

  6. Influence of diameter and intraradicular post in the stress distribution. Finite element analysis

    Directory of Open Access Journals (Sweden)

    Cleidiel Aparecido Araujo LEMOS

    Full Text Available Abstract Introduction The biomechanical behavior of endodontically treated teeth depending on the selected restorative material and tooth situation to be restored. Objective To analyze by the two-dimensional finite element method the biomechanical behavior of different diameters in intraradicular posts and teeth with coronal remaining of 2mm. Material and method Six models were made with three types of posts, as follows: Glass fiber post, carbon fiber post, and cast metal post, both with diameter # 1 (1.1 mm in diameter and # 2 (1.3 mm of diameter. The modeling was performed using the Rhinoceros 4.0 program. The FEMAP 10.2 and NEiNastran 9.2 programs were used to develop finite element models. The loading used was 100N for axial and oblique forces. The results were visualized using the von Mises stress map. The statistical analysis was made using analysis of variance (ANOVA and Tukey post-test, with a significance level of 5%. Result The oblique loading stress values were higher than the axial loading (p<0.001 for both situations. The glass fiber post showed the lowest concentrations of stress on both loads (p<0.001. The carbon fiber post presented significant difference compared to the cast metal post, only in the oblique load (p=0.007. The diameter did not increase the stress of the evaluated posts (p=0.302. Conclusion The fiber posts were more favorable for restoration of endodontically treated teeth; the increase of diameter did not influence the increase of tension; the oblique load was more harmful for both posts and tooth structure.

  7. Monitoring the penetration process of single microneedles with varying tip diameters.

    Science.gov (United States)

    Römgens, A M; Bader, D L; Bouwstra, J A; Baaijens, F P T; Oomens, C W J

    2014-12-01

    Microneedles represent promising tools for delivery of drugs to the skin. However, before these microneedles can be used in clinical practice, it is essential to understand the process of skin penetration by these microneedles. The present study was designed to monitor both penetration depth and force of single solid microneedles with various tip diameters ranging from 5 to 37µm to provide insight into the penetration process into the skin of these sharp microneedles. To determine the microneedle penetration depth, single microneedles were inserted in human ex vivo skin while monitoring the surface of the skin. Simultaneously, the force on the microneedles was measured. The average penetration depth at 1.5mm displacement was similar for all tip diameters. However, the process of penetration depth was significantly different for the various microneedles. Microneedles with a tip diameter of 5µm were smoothly inserted into the skin, while the penetration depth of microneedles with a larger tip diameter suddenly increased after initial superficial penetration. In addition, the force at insertion (defined as the force at a sudden decrease in measured force) linearly increased with tip diameter ranging from 20 to 167mN. The force drop at insertion was associated with a measured penetration depth of approximately 160μm for all tip diameters, suggesting that the drop in force was due to the penetration of a deeper skin layer. This study showed that sharp microneedles are essential to insert microneedles in a well-controlled way to a desired depth. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

  8. Low-density lipoprotein particle diameter and mortality: the Ludwigshafen Risk and Cardiovascular Health Study

    OpenAIRE

    Grammer, Tanja B.; Kleber, Marcus E; März, Winfried; Silbernagel, Günther; Siekmeier, Rüdiger; Wieland, Heinrich; Pilz, Stefan; Tomaschitz, Andreas; Koenig, Wolfgang; Scharnagl, Hubert

    2017-01-01

    Aims The aim of the study was to examine whether differences in average diameter of low-density lipoprotein (LDL) particles were associated with total and cardiovascular mortality. Methods and results We studied 1643 subjects referred to coronary angiography, who did not receive lipid-lowering drugs. During a median follow-up of 9.9 years, 398 patients died, of these 246 from cardiovascular causes. We calculated average particle diameters of LDL from the composition of LDL obtained by β-quant...

  9. Indirect and direct methods for measuring a dynamic throat diameter in a solid rocket motor

    Science.gov (United States)

    Colbaugh, Lauren

    In a solid rocket motor, nozzle throat erosion is dictated by propellant composition, throat material properties, and operating conditions. Throat erosion has a significant effect on motor performance, so it must be accurately characterized to produce a good motor design. In order to correlate throat erosion rate to other parameters, it is first necessary to know what the throat diameter is throughout a motor burn. Thus, an indirect method and a direct method for determining throat diameter in a solid rocket motor are investigated in this thesis. The indirect method looks at the use of pressure and thrust data to solve for throat diameter as a function of time. The indirect method's proof of concept was shown by the good agreement between the ballistics model and the test data from a static motor firing. The ballistics model was within 10% of all measured and calculated performance parameters (e.g. average pressure, specific impulse, maximum thrust, etc.) for tests with throat erosion and within 6% of all measured and calculated performance parameters for tests without throat erosion. The direct method involves the use of x-rays to directly observe a simulated nozzle throat erode in a dynamic environment; this is achieved with a dynamic calibration standard. An image processing algorithm is developed for extracting the diameter dimensions from the x-ray intensity digital images. Static and dynamic tests were conducted. The measured diameter was compared to the known diameter in the calibration standard. All dynamic test results were within +6% / -7% of the actual diameter. Part of the edge detection method consists of dividing the entire x-ray image by an average pixel value, calculated from a set of pixels in the x-ray image. It was found that the accuracy of the edge detection method depends upon the selection of the average pixel value area and subsequently the average pixel value. An average pixel value sensitivity analysis is presented. Both the indirect

  10. Growth of laser damage in fused silica: diameter to depth ratio

    Energy Technology Data Exchange (ETDEWEB)

    Norton, M A; Adams, J J; Carr, C W; Donohue, E E; Feit, M D; Hackel, R P; Hollingsworth, W G; Jarboe, J A; Matthews, M; Rubenchik, A M; Spaeth, M L

    2007-10-29

    Growth of laser initiated damage plays a major role in determining optics lifetime in high power laser systems. Previous measurements have established that the lateral diameter grows exponentially. Knowledge of the growth of the site in the propagation direction is also important, especially so when considering techniques designed to mitigate damage growth, where it is required to reach all the subsurface damage. In this work, we present data on both the diameter and the depth of a growing exit surface damage sites in fused silica. Measured growth rates with both 351 nm illumination and with combined 351 nm and 1054 nm illumination are discussed.

  11. Optimization of the Critical Diameter and Average Path Length of Social Networks

    Directory of Open Access Journals (Sweden)

    Haifeng Du

    2017-01-01

    Full Text Available Optimizing average path length (APL by adding shortcut edges has been widely discussed in connection with social networks, but the relationship between network diameter and APL is generally ignored in the dynamic optimization of APL. In this paper, we analyze this relationship and transform the problem of optimizing APL into the problem of decreasing diameter to 2. We propose a mathematic model based on a memetic algorithm. Experimental results show that our algorithm can efficiently solve this problem as well as optimize APL.

  12. A novel high birefringence equal diameter circular-hole photonic crystal fiber

    Science.gov (United States)

    Guo, Jun-qi; Zhong, Yi; Liu, Yu; Yang, Xiao-hui; Xiao, Ming-lang; Zhou, Min

    2017-09-01

    A novel equal diameter circular-hole photonic crystal fiber (PCF) with high birefringence is proposed and numerically analyzed by employing the finite-element method. The proposed PCF's birefringence is 10-3, which can reach 2 orders higher than that of traditional high birefringence fiber, and this equal diameter circular-hole structure reduces the difficulty of the actual drawing process. The effect of different parameters on the birefringence of this PCF is investigated, and the application of the Sagnac interferometer based on fiber filling technology in temperature sensing is studied. The result shows that the high birefringence PCF can be used in both optical communication and optical sensing fields.

  13. A Robotic System for Inspection and Repair of Small Diameter Pipelines

    Directory of Open Access Journals (Sweden)

    S. A. Vorotnikov

    2015-01-01

    Full Text Available This paper deals with the construction and control system of miniature robotic system that is designed to move and make inspection inside small diameter pipelines. It gives an overview of ways to move a microsize robotic system inside the small diameter pipe. The proposed design consists of information module and three traction modules, including modules for fixing, linear moving and angular positioning. This paper describes the design and operation of a robotic system and its different modules. Also are shown the structure of the robot control system, the basic calculations of construct and some simulation results of the individual modules of the robot.

  14. Bloch-wave engineered submicron-diameter quantum-dot micropillars for cavity QED experiments

    DEFF Research Database (Denmark)

    Gregersen, Niels; Lermer, Matthias; Reitzenstein, Stephan

    2013-01-01

    The semiconductor micropillar is attractive for cavity QED experiments. For strong coupling, the figure of merit is proportional to Q/√V, and a design combining a high Q and a low mode volume V is thus desired. However, for the standard submicron diameter design, poor mode matching between the ca...... the cavity and the DBR Bloch mode limits the Q. We present a novel adiabatic design where Bloch-wave engineering is employed to improve the mode matching, allowing the demonstration of a record-high vacuum Rabi splitting of 85 μeV and a Q of 13600 for a 850 nm diameter micropillar....

  15. Ultrasonographic measurement of normal common bile duct diameter and its correlation with age, sex and anthropometry.

    Science.gov (United States)

    Lal, Nidhi; Mehra, Simmi; Lal, Vivek

    2014-12-01

    Ultrasonography is the diagnostic method of choice for visualization and rational work-up of abdominal organs. The dilatation of the common bile duct helps distinguish obstructive from non-obstructive causes of jaundice. Availability of normal measurements of the common bile duct is therefore important. There exists significant variations in the anthropometric features of various populations, regions and races. Study was conducted to obtain data on sonographically measured diameters of common bile duct in a series of normal Rajasthani population and to measure its correlation with age, sex and anthropometry. Cross-sectional hospital-based study conducted at Mahatma Gandhi Medical College and Hospital, Jaipur, India. Study included 200 participants with equal proportion belonging to either sex. Common bile duct was measured at three locations- at the porta hepatis, in the most distal aspect of head of pancreas and mid-way between these points. Anthropometric measurements including height, weight, chest circumference, circumference at transpyloric plane, circumference at umbilicus and circumference at hip were obtained using standard procedures. Univariable analysis with measures of frequency and standard deviation and bivariable analysis using correlation. Mean age of study subjects was 34.5 years (Range 18-85 years). Mean diameters of the common bile duct in the three locations were: proximal, 4.0 mm (SD 1.02 mm); middle, 4.1 mm (SD 1.01 mm); and distal, 4.2 mm (SD 1.01 mm) and overall mean for all measures 4.1 mm (SD 1.01 mm). Average diameter ranged from 2.0 mm to 7.9 mm, with 95 percent of the subjects having a diameter of less than 6 mm. We observed a statistically significant relation of common bile duct with age, along with a linear trend. There was no statistically significant difference in common bile duct diameter between male and female subjects. The diameter did not show any statistically significant correlation with any of the anthropometric

  16. 77 FR 15042 - Small Diameter Graphite Electrodes From the People's Republic of China: Amended Final Results of...

    Science.gov (United States)

    2012-03-14

    ... International Trade Administration Small Diameter Graphite Electrodes From the People's Republic of China... the antidumping duty administrative review of small diameter graphite electrodes (``SDGE'') from the... (``the Act''), and 19 CFR 351.224(e). \\1\\ See Small Diameter Graphite Electrodes from the People's...

  17. 76 FR 56397 - Small Diameter Graphite Electrodes from the People's Republic of China: Final Results of the...

    Science.gov (United States)

    2011-09-13

    ... International Trade Administration Small Diameter Graphite Electrodes from the People's Republic of China: Final... results of the first administrative review of the antidumping duty order on small diameter graphite..., through January 31, 2010. See Small Diameter Graphite Electrodes from the People's Republic of China...

  18. 76 FR 36092 - Small Diameter Graphite Electrodes From the People's Republic of China: Extension of Time Limit...

    Science.gov (United States)

    2011-06-21

    ... International Trade Administration Small Diameter Graphite Electrodes From the People's Republic of China... Department'') initiated the administrative review of the antidumping duty order on small diameter graphite... March 7, 2011. See Small Diameter Graphite Electrodes From the People's Republic of China: Preliminary...

  19. 77 FR 6060 - Small Diameter Graphite Electrodes from the People's Republic of China: Extension of Time Limit...

    Science.gov (United States)

    2012-02-07

    ... International Trade Administration Small Diameter Graphite Electrodes from the People's Republic of China... antidumping duty order on small diameter graphite electrodes from the People's Republic of China (PRC) for the... February 3, 2012. See Small Diameter Graphite Electrodes from the People's Republic of China: Extension of...

  20. 77 FR 40854 - Small Diameter Graphite Electrodes From the People's Republic of China: Final Results of the...

    Science.gov (United States)

    2012-07-11

    ... International Trade Administration Small Diameter Graphite Electrodes From the People's Republic of China: Final... diameter graphite electrodes (SDGEs) from the People's Republic of China (PRC). The review covers 25...: Background On March 6, 2012, the Department published Small Diameter Graphite Electrodes from the People's...

  1. Analysis of the radius and diameter protocols in terms of pricing telecommunication services

    Directory of Open Access Journals (Sweden)

    Vesna M. Radonjić

    2013-06-01

    Full Text Available Accounting of telecommunication services is closely related to the functions of authentication and authorization. These functions are usually considered together and implemented within the same server using a common protocol. The most renowned protocols for authentication, authorization and accounting are the RADIUS and Diameter protocols.   AAA functions and related protocols   In this chapter, the accounting management architecture developed by IETF is presented. It includes the interaction between network elements, accounting servers and billing and charging servers. Accounting data can be used for management, planning and charging users as well as other (specific purposes. Authentication is the process of confirming a user's digital identity, usually through some type of identifiers and related data. Authorization determines whether a particular entity is authorized to perform an activity.   Basic Functions of the RADIUS Protocol   The RADIUS architecture is based on a client-server model. It uses UDP on the transport layer. Transactions between the client and the server are authenticated, which is achieved by using a common secret key that is never sent through the network. Given the limited resources available to network devices, RADIUS facilitates and centralizes charging end users, provides some protection against active attacks by unauthorized users and it has great support from different network equipment vendors. Although RADIUS is a widely accepted protocol for the mechanisms of authentication, authorization and accounting, it has certain shortcomings that may be caused by the protocol itself or by its poor implementation.   Architecture and Operation of the Diameter Protocol   Diameter is a scalable protocol designed by the IETF working group in order to eliminate shortcomings and functional limitations of the RADIUS protocol and eventually to replace it in the near future. Most of the basic Diameter mechanisms and its

  2. Controlling the optical path length in turbid media using differential path-length spectroscopy: fiber diameter dependence.

    Science.gov (United States)

    Kaspers, O P; Sterenborg, H J C M; Amelink, A

    2008-01-20

    We have characterized the path length for the differential path-length spectroscopy (DPS) fiber optic geometry for a wide range of optical properties and for fiber diameters ranging from 200 microm to 1000 microm. Phantom measurements show that the path length is nearly constant for scattering coefficients in the range 5 mm(-1)path length is proportional to the fiber diameter. The path length decreases with increasing absorption for all fiber diameters, and this effect is more pronounced for larger fiber diameters. An empirical model is formulated that relates the DPS path length to total absorption for all fiber diameters simultaneously.

  3. Large volume sample introduction using temperature programmable injectors: imlications of liner diameter.

    NARCIS (Netherlands)

    Mol, H.G.J.; Janssen, H.G.; Cramers, C.A.; Brinkman, U.A.T.

    1995-01-01

    Temperature programmable injectors with liner diameters ranging from 1 to 3.5 mm are evaluated and compared for solvent split injection of large volumes in capillary gas chromatography. The liner dimensions determine whether a large sample volume can be introduced rapidly or has to be introduced in

  4. Analysis of Individual Tree Competition Effect on Diameter Growth of Silver Birch in Estonia

    Directory of Open Access Journals (Sweden)

    Kobra Maleki

    2015-08-01

    Full Text Available Aim of study: The present study evaluates a set of competition indices including spatially explicit indices combined with different competitor selection approaches and non-spatially explicit competition indices. The aim was to quantify and describe the neighbouring effects on the tree diameter growth of silver birch trees. Area of study: Region throughout Estonia. Material and methods: Data from the Estonian Network of Forest Research Plots was used. After quantifying the selected indices, the best non-spatial indices and spatial indices (combined with neighbour selection methods were separately devised into a growth model as a predictor variable to assess the ability of the diameter growth model before and after adding competition measures. To test the species-specific effect on the competition level, the superior indices were recalculated using Ellenberg’s light indicators and incorporated into the diameter growth model. Main results: Statistical analyses showed that the diameter growth is a function of neighbourhood interactions and spatial indices were better growth predictors than non-spatial indices. In addition, the best selections of competitive neighbours were acquired based on the influence zone and the competition elimination angle concepts, and using Ellenberg’s light values had no significant improvement in quantifying the competition effects. Research highlights: Although the best ranking spatial competition measures were superior to the best non-spatial indices, the differences were negligible.

  5. Exploring the bark thickness-stem diameter relationship: clues from lianas, successive cambia, monocots and gymnosperms.

    Science.gov (United States)

    Rosell, Julieta A; Olson, Mark E; Anfodillo, Tommaso; Martínez-Méndez, Norberto

    2017-07-01

    Bark thickness is ecologically crucial, affecting functions from fire protection to photosynthesis. Bark thickness scales predictably with stem diameter, but there is little consensus on whether this scaling is a passive consequence of growth or an important adaptive phenomenon requiring explanation. With a comparative study across 913 species, we test the expectation that, if bark thickness-stem diameter scaling is adaptive, it should be possible to find ecological situations in which scaling is predictably altered, in this case between species with different types and deployments of phloem. 'Dicots' with successive cambia and monocots, which have phloem-free bark, had predictably thinner inner (mostly living) bark than plants with single cambia. Lianas, which supply large leaf areas with limited stem area, had much thicker inner bark than self-supporting plants. Gymnosperms had thicker outer bark than angiosperms. Inner bark probably scales with plant metabolic demands, for example with leaf area. Outer bark scales with stem diameter less predictably, probably reflecting diverse adaptive factors; for example, it tends to be thicker in fire-prone species and very thin when bark photosynthesis is favored. Predictable bark thickness-stem diameter scaling across plants with different photosynthate translocation demands and modes strongly supports the idea that this relationship is functionally important and adaptively significant. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

  6. Fabrication and Characterization of Single Phase α-Alumina Membranes with Tunable Pore Diameters

    Directory of Open Access Journals (Sweden)

    Tatsuya Masuda

    2015-03-01

    Full Text Available Nanoporous and single phase α-alumina membranes with pore diameters tunable over a wide range of approximately 60–350 nm were successfully fabricated by optimizing the conditions for anodizing, subsequent detachment, and heat treatment. The pore diameter increased and the cell diameter shrunk upon crystallization to α-alumina by approximately 20% and 3%, respectively, in accordance with the 23% volume shrinkage resulting from the change in density associated with the transformation from the amorphous state to α-alumina. Nevertheless, flat α-alumina membranes, each with a diameter of 25 mm and a thickness of 50 μm, were obtained without thermal deformation. The α-alumina membranes exhibited high chemical resistance in various concentrated acidic and alkaline solutions as well as when exposed to high temperature steam under pressure. The Young’s modulus and hardness of the single phase α-alumina membranes formed by heat treatment at 1250 °C were notably decreased compared to the corresponding amorphous membranes, presumably because of the nodular crystallite structure of the cell walls and the substantial increase in porosity. Furthermore, when used for filtration, the α-alumina membrane exhibited a level of flux higher than that of the commercial ceramic membrane.

  7. Development of an inspection robot for small diameter gas distribution mains

    NARCIS (Netherlands)

    Dertien, Edwin Christian; Stramigioli, Stefano; Pulles, Kees

    2011-01-01

    This paper discusses the design of a mechanical structure of a miniature pipe inspection robot capable of moving through very small pipes (down to 41 mm inner diameter). The requirement to negotiate bends, T-joints and steep inclinations pose another set of strict design constraints. The proposed

  8. Nonuniform Internal Structure of Fibrin Fibers: Protein Density and Bond Density Strongly Decrease with Increasing Diameter.

    Science.gov (United States)

    Li, Wei; Sigley, Justin; Baker, Stephen R; Helms, Christine C; Kinney, Mary T; Pieters, Marlien; Brubaker, Peter H; Cubcciotti, Roger; Guthold, Martin

    2017-01-01

    The major structural component of a blood clot is a meshwork of fibrin fibers. It has long been thought that the internal structure of fibrin fibers is homogeneous; that is, the protein density and the bond density between protofibrils are uniform and do not depend on fiber diameter. We performed experiments to investigate the internal structure of fibrin fibers. We formed fibrin fibers with fluorescently labeled fibrinogen and determined the light intensity of a fiber, I, as a function of fiber diameter, D. The intensity and, thus, the total number of fibrin molecules in a cross-section scaled as D(1.4). This means that the protein density (fibrin per cross-sectional area), ρp , is not homogeneous but instead strongly decreases with fiber diameter as D(-0.6). Thinner fibers are denser than thicker fibers. We also determined Young's modulus, Y, as a function of fiber diameter. Y decreased strongly with increasing D; Y scaled as D(-1.5). This implies that the bond density, ρb , also scales as D(-1.5). Thinner fibers are stiffer than thicker fibers. Our data suggest that fibrin fibers have a dense, well-connected core and a sparse, loosely connected periphery. In contrast, electrospun fibrinogen fibers, used as a control, have a homogeneous cross-section.

  9. Behavior and sensitivity of an optimal tree diameter growth model under data uncertainty

    Science.gov (United States)

    Don C. Bragg

    2005-01-01

    Using loblolly pine, shortleaf pine, white oak, and northern red oak as examples, this paper considers the behavior of potential relative increment (PRI) models of optimal tree diameter growth under data uncertainity. Recommendations on intial sample size and the PRI iteractive curve fitting process are provided. Combining different state inventories prior to PRI model...

  10. Contrast and stability of the axon diameter index from microstructure imaging with diffusion MRI

    DEFF Research Database (Denmark)

    Dyrby, Tim B; Søgaard, Lise V; Hall, Matt G

    2013-01-01

    (max) ) on a scanner influence the sensitivity to a range of axon diameters. Multishell high-angular-diffusion-imaging (HARDI) protocols for G(max) of 60, 140, 200, and 300 mT/m were optimized for the pulsed-gradient-spin-echo (PGSE) sequence. Data were acquired on a fixed monkey brain and Monte-Carlo simulations...

  11. Sap volume flow as influenced by tubing diameter and slope percent

    Science.gov (United States)

    H. Clay Smith

    1971-01-01

    The amount of sugar maple sap that can move through plastic tubing is controlled by several factors. The most important are tubing diameter and slope percent. Estimates are given of the number of tapholes that can be used with combinations of these variables.

  12. Economic feasibility of producing inside-out beams from small-diameter logs

    Science.gov (United States)

    David W. Patterson; Richard A. Kluender; James E. Granskog

    2002-01-01

    Previous work has shown that it is technically feasible to produce inside-out (ISO) beams by taking small-diameter (5 to 7 in.) logs, slabbing four sides, quartering the cant, and turning the quarters inside out and gluing them together. After drying, the beams were found to be straight, with no cracks, and of equal or better mechanical properties than solid sawn...

  13. Diameter-density relationships provide tentative spacing guidelines for Eucalyptus saligna in Hawaii

    Science.gov (United States)

    Dean S. DeBell; Craig D. Whitesell

    1988-01-01

    Trials have been established in Hawaii to develop spacing guidelines for Eucalyptus saligna plantations. Substantial competition-related mortality occurred in densely planted plots of three spacing trials. Data on stand diameter and surviving number of trees on these plots were plotted in logarithmic form to estimate a "self-thinning" or...

  14. Crown radius and diameter at breast height relationships for six bottomland hardwood species

    Science.gov (United States)

    Brian Roy Lockhart; Robert C. Weih; Keith M. Smith

    2005-01-01

    The relationship between a tree's crown radius and diameter at breast height (DBH) has a variety of uses including forest competition studies, tree crown densities, spacing and stocking relationships, wildlife habitat suitability models, and tree volume estimations. Estimating DBH from mean crown radius (MCR) is of interest to natural resource managers because MCR...

  15. Research challenges for structural use of small-diameter round timbers

    Science.gov (United States)

    Ron Wolfe

    2000-01-01

    Forest managers have identified forest stands overstocked with small-diameter trees as a critical forest health issue. Overstocked stands are subject to attack by insects and disease and, as a result of the heavy fuel load, risk total destruction by fire. Prescribed burning is an economic tool for suppressing the growth of brush and tree seedlings, but its use is often...

  16. Small-diameter log evaluation for value-added structural applications

    Science.gov (United States)

    Ronald. Wolfe; Cassandra. Moseley

    2000-01-01

    Three species of small-diameter logs from the Klamath/Siskiyou Mountains and the Cascade Range in southwest Oregon were tested for their potential for value-added structural applications. The logs were tested in bending and compression parallel to the grain. Strength and stiffness values were correlated to possible nondestructive evaluation grading parameters and...

  17. RUBBING TEST RESPONSES OF THE SKIN TO MAN-MADE MINERAL FIBERS OF DIFFERENT DIAMETERS

    NARCIS (Netherlands)

    STAMWESTERVELD, EB; COENRAADS, PJ; VANDERVALK, PGM; DEJONG, MCJM; FIDLER, [No Value

    The irritant potency of 5 types of insulation wools (2 types of rockwool and 3 types of glasswool) were studied on the basis of their differences in diameter by a standardized rubbing test. Assessment was done by laser Doppler flowmetry (LDF) and erythema scores. Insulation wools show a wide

  18. Effect of tube-electrode inner diameter on electrochemical discharge machining of nickel-based superalloy

    Directory of Open Access Journals (Sweden)

    Zhang Yan

    2016-08-01

    Full Text Available Nickel-based superalloys are widely employed in modern aircraft engines because of their excellent material characteristics, particularly in the fabrication of film cooling holes. However, the high machining requirement of a large number of film cooling holes can be extremely challenging. The hybrid machining technique of tube electrode high-speed electrochemical discharge drilling (TEHECDD has been considered as a promising method for the production of film cooling holes. Compared with any single machining process, this hybrid technique requires the removal of more complex machining by-products, including debris produced in the electrical discharge machining process and hydroxide and bubbles generated in the electrochemical machining process. These by-products significantly affect the machining efficiency and surface quality of the machined products. In this study, tube electrodes in different inner diameters are designed and fabricated, and the effects of inner diameter on the machining efficiency and surface quality of TEHECDD are investigated. The results show that larger inner diameters could effectively improve the flushing condition and facilitate the removal of machining by-products. Therefore, higher material removal efficiency, surface quality, and electrode wear rate could be achieved by increasing the inner diameter of the tube electrode.

  19. AP diameter shows the strongest correlation with CTDI and DLP in abdominal and chest CT.

    LENUS (Irish Health Repository)

    Zarb, Francis

    2010-01-01

    The purpose of this study is to investigate the relationships among cross-sectional diameters, weight and computed tomography (CT) dose descriptors (CTDI and DLP) to identify which is best used as a measure for the establishment of DRLs in CT. Data (gender, weight, cross-sectional diameters, dose descriptors) from 56 adult patients attending for either a CT examination of the abdomen or chest was obtained from two spiral CT units using automatic milliampere modulation. The AP diameter was demonstrated as the main contributing factor influencing the dose in CT (CTDI: r(2) = 0.269, p-value < or =0.001; DLP: r(2) = 0.260, p-value < or =0.001) since it has a greater correlation with radiation dose than body weight and can thus be its substitute in dose-reduction strategies and establishment of DRLs. The advantages of using the AP diameter are that it can easily be measured prior to scanning or retrospectively from previous CT images. However, further studies on the practicality of this approach are recommended.

  20. Effect of grain port length-diameter ratio on combustion performance in hybrid rocket motors

    Science.gov (United States)

    Cai, Guobiao; Zhang, Yuanjun; Tian, Hui; Wang, Pengfei; Yu, Nanjia

    2016-11-01

    The objectives of this study are to develop a more accurate regression rate considering the oxidizer mass flow and the fuel grain geometry configuration with numerical and experimental investigations in polyethylene (PE)/90% hydrogen peroxide (HP) hybrid rocket. Firstly, a 2-D axisymmetric CFD model with turbulence, chemistry reaction, solid-gas coupling is built to investigate the combustion chamber internal flow structure. Then a more accurate regression formula is proposed and the combustion efficiency changing with the length-diameter ratio is studied. A series experiments are conducted in various oxidizer mass flow to analyze combustion performance including the regression rate and combustion efficiency. The regression rates are measured by the fuel mass reducing and diameter changing. A new regression rate formula considering the fuel grain configuration is proposed in this paper. The combustion efficiency increases with the length-diameter ratio changing. To improve the performance of a hybrid rocket motor, the port length-diameter ratio is suggested 10-12 in the paper.

  1. Brachial artery diameter is related to cardiovascular risk factors and intima-media thickness.

    NARCIS (Netherlands)

    Holewijn, S.; Heijer, M. den; Swinkels, D.W.; Stalenhoef, A.F.H.; Graaf, J. de

    2009-01-01

    BACKGROUND: Previous reports showed inconsistent results about the potential role of flow-mediated dilatation (FMD) in cardiovascular(CV) risk prediction. Few data are available about the role of nitroglycerin-mediated dilatation (NMD), but recently, brachial artery diameter(BAD) appeared to have

  2. Impact of stand diameter and product markets on revenue gains from multiproduct harvesting

    Science.gov (United States)

    John E. Baumgras; Chris B. LeDoux

    1988-01-01

    Data from 113 sample thinning plots and a microcomputer program called APTHIN were used to demonstrate the impact of mean stand diameter and product markets on revenue gains from multiproduct versus single-product pulpwood harvests in poletimber and small sawtimber stands of Appalachian hardwoods. The analysis of revenue gains included product mix as a function of the...

  3. Diameter effect and detonation front curvature of ideal and non-ideal explosives

    Science.gov (United States)

    Sandstrom, F. W.; Abernathy, R. L.; Leone, M. G.; Banks, M. L.

    2000-04-01

    Diameter effect and detonation front curvature data are presented for several representative ideal and non-ideal explosives, including cast TNT, Tritonal, urea nitrate (UN), ANFO, and two variants of ammonium nitrate (AN)/solid fuel explosives. The ideal vs. non-ideal detonation characteristics of these various explosives are compared and contrasted with respect to particle size and chemical composition.

  4. Taguchi analysis of parameters for small-diameter single wall carbon nanotube growth

    Directory of Open Access Journals (Sweden)

    DaeJin Kang

    2017-09-01

    Full Text Available Small diameter single wall carbon nanotubes are desirable for various physical and electrical properties of carbon nanotubes. Here, we report the sensitivities of parameters and the optimal conditions for small diameter carbon nanotube growth by chemical vapor deposition (CVD. These results were obtained using the Taguchi method, which is commonly used to find the optimal parameters of various processes. The possible parameter ranges given by the experimental equipment and laboratory conditions, we attempted several times to determine the proper ranges, using photoluminescence (PL imaging to determine the exact positions of suspended carbon nanotubes on the quartz substrates after synthesis. The diameters of the carbon nanotubes were then determined from the radial breathing modes (RBM using Raman spectroscopy with a 785nm wavelength laser. Among the 4 major parameters listed above, we concluded that the temperature was the most significant parameter in determining carbon nanotube diameter, hydrogen flow rate was the second most significant, the ethanol and argon gas flow rate was the third, and finally time was the least significant factor.

  5. Taguchi analysis of parameters for small-diameter single wall carbon nanotube growth

    Science.gov (United States)

    Kang, DaeJin; Yang, Sisi; Wang, Bo; Chen, Jihan; Dhall, Rohan; Hou, Bingya; Kang, Jimin; Cronin, Stephen B.

    2017-09-01

    Small diameter single wall carbon nanotubes are desirable for various physical and electrical properties of carbon nanotubes. Here, we report the sensitivities of parameters and the optimal conditions for small diameter carbon nanotube growth by chemical vapor deposition (CVD). These results were obtained using the Taguchi method, which is commonly used to find the optimal parameters of various processes. The possible parameter ranges given by the experimental equipment and laboratory conditions, we attempted several times to determine the proper ranges, using photoluminescence (PL) imaging to determine the exact positions of suspended carbon nanotubes on the quartz substrates after synthesis. The diameters of the carbon nanotubes were then determined from the radial breathing modes (RBM) using Raman spectroscopy with a 785nm wavelength laser. Among the 4 major parameters listed above, we concluded that the temperature was the most significant parameter in determining carbon nanotube diameter, hydrogen flow rate was the second most significant, the ethanol and argon gas flow rate was the third, and finally time was the least significant factor.

  6. Determination of Nerve Fiber Diameter Distribution From Compound Action Potential: A Continuous Approach.

    Science.gov (United States)

    Un, M Kerem; Kaghazchi, Hamed

    2018-01-01

    When a signal is initiated in the nerve, it is transmitted along each nerve fiber via an action potential (called single fiber action potential (SFAP)) which travels with a velocity that is related with the diameter of the fiber. The additive superposition of SFAPs constitutes the compound action potential (CAP) of the nerve. The fiber diameter distribution (FDD) in the nerve can be computed from the CAP data by solving an inverse problem. This is usually achieved by dividing the fibers into a finite number of diameter groups and solve a corresponding linear system to optimize FDD. However, number of fibers in a nerve can be measured sometimes in thousands and it is possible to assume a continuous distribution for the fiber diameters which leads to a gradient optimization problem. In this paper, we have evaluated this continuous approach to the solution of the inverse problem. We have utilized an analytical function for SFAP and an assumed a polynomial form for FDD. The inverse problem involves the optimization of polynomial coefficients to obtain the best estimate for the FDD. We have observed that an eighth order polynomial for FDD can capture both unimodal and bimodal fiber distributions present in vivo, even in case of noisy CAP data. The assumed FDD distribution regularizes the ill-conditioned inverse problem and produces good results.

  7. Reduced right ventricular diameter during cardiac arrest caused by tension pneumothorax - a porcine ultrasound study.

    Science.gov (United States)

    Caap, P; Aagaard, R; Sloth, E; Løfgren, B; Granfeldt, A

    2017-08-01

    Advanced life support (ALS) guidelines recommend ultrasound to identify reversible causes of cardiac arrest. Right ventricular (RV) dilatation during cardiac arrest is commonly interpreted as a sign of pulmonary embolism. The RV is thus a focus of clinical ultrasound examination. Importantly, in animal studies ventricular fibrillation and hypoxia results in RV dilatation. Tension pneumothorax (tPTX) is another reversible cause of cardiac arrest, however, the impact on RV diameter remains unknown. To investigate RV diameter evaluated by ultrasound in cardiac arrest caused by tPTX or hypoxia. Pigs were randomized to cardiac arrest by either tPTX (n = 9) or hypoxia (n = 9) and subsequently resuscitated. Tension pneumothorax was induced by injection of air into the pleural cavity. Hypoxia was induced by reducing tidal volume. Ultrasound images of the RV were obtained throughout the study. Tension pneumothorax was decompressed after the seventh rhythm analysis. The primary endpoint was RV diameter after the third rhythm analysis. At cardiac arrest the RV diameter was 17 mm (95% CI: 13; 21) in the tPTX group and 36 mm (95% CI: 33; 40) in the hypoxia group (P cardiac arrest caused by tPTX when compared with hypoxia. The difference disappears after tPTX decompression. © 2017 The Acta Anaesthesiologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

  8. The influence of the inside diameter of the coring probe on the ...

    African Journals Online (AJOL)

    The obtaining of a representative sample is crucial for the application of an accurate and uniform lucerne hay grading system in South Africa. There is currently limited data available on the effect of the inside diameter of the coring probe on the chemical composition of the lucerne hay samples. A study was therefore ...

  9. Affective Assessment of a Computer User through the Processing of the Pupil Diameter Signal

    Science.gov (United States)

    Gao, Ying; Barreto, Armando; Adjouadi, Malek

    This study proposes to achieve the affective assessment of a computer user through the processing of the pupil diameter (PD) signal. An adaptive interference canceller (AIC) system using the H∞ time-varying (HITV) adaptive algorithm was developed to minimize the impact of the PLR (pupil size changes caused by light intensity variations) on the measured pupil diameter signal. The modified pupil diameter (MPD) signal, obtained from the AIC, was expected to reflect primarily the pupillary affective responses (PAR) of the subject. Additional manipulations of the AIC output resulted in a Processed MPD (PMPD) signal, from which a classification feature, “PMPDmean”, was extracted. This feature was used to train and test a support vector machine (SVM), for the identification of “stress” states in the subject, achieving an accuracy rate of 77.78%. The advantages of affective recognition through the PD signal were verified by comparatively investigating the classification of “stress” and “relaxation” states through features derived from the simultaneously recorded galvanic skin response (GSR) and blood volume pulse (BVP) signals, with and without the PD feature. Encouraging results in affective assessment based on pupil diameter monitoring were obtained in spite of intermittent illumination increases purposely introduced during the experiments. Therefore, these results confirmed the possibility of using PD monitoring to evaluate the evolving affective states of a computer user.

  10. Improved utilization of small-diameter ponderosa pine in glulam timber

    Science.gov (United States)

    Roland Hernandez; David W. Green; David E. Kretschmann; Steven P. Verrill

    2005-01-01

    This study involved the evaluation of ponderosa pine glulam made from lumber that was sawn from a small-diameter timber resource. Two different glulam beam depths were evaluated: 8 and 13 laminations. A comprehensive glulam test program was conducted to evaluate edgewise and flat-wise bending, shear, and tensile strength. Beam deflection was measured and a variety of...

  11. Structural lumber from dense stands of small-diameter Douglas-fir trees.

    Science.gov (United States)

    David W. Green; Eini C. Lowell; Roland. Hernandez

    2005-01-01

    Small-diameter trees growing in overstocked dense stands are often targeted for thinning to reduce fire hazard and improve forest health and ecosystem diversity. In the Pacific Northwest and Intermountain regions, Douglas-fir can be a predominant species in such stands. In this study, mechanical properties and grade yield of structural products were estimated for 2 by...

  12. Effects of diameter and helical angle of flute on the flow evenness of ...

    African Journals Online (AJOL)

    In this study, the optimum dimensions of flute diameter and helical angle of fluted roller used in seed drills were determined for lentil seeds at 100 kg ha-1 of seed rate. The values of coefficient variation were used to determine the optimum dimensions of fluted rollers. The best rates of flow evenness and the minimum ...

  13. Retinal vessel diameters in relation to hematocrit variation during acclimatization of highlanders to sea level altitude

    DEFF Research Database (Denmark)

    Kofoed, Peter Kristian; Sander, Birgit; Zubieta-Calleja, Gustavo

    2009-01-01

    PURPOSE: To examine variations in retinal vessel diameters during acclimatization of native highlanders to normobaric normoxia at sea level. METHODS: Fifteen healthy residents of the greater La Paz region in Bolivia (3600 m above sea level) were examined thrice over a 72-day period, after having ...

  14. Proceedings of the conference on diameter-limit cutting in northeastern forests

    Science.gov (United States)

    Laura S. Kenefic; Ralph D., eds. Nyland; Ralph D. Nyland

    2006-01-01

    Contains nine papers presented at the conference on diameter-limit cutting in northeastern forests on May 23-24, 2005, at the University of Massachusetts at Amherst. NOTE, this is the full-text document. Individual papers are available via Treesearch.

  15. Retinal hemodynamic oxygen reactivity assessed by perfusion velocity, blood oximetry and vessel diameter measurements

    DEFF Research Database (Denmark)

    Klefter, Oliver Niels; Lauritsen, Anne Øberg; Larsen, Michael

    2015-01-01

    PURPOSE: To test the oxygen reactivity of a fundus photographic method of measuring macular perfusion velocity and to integrate macular perfusion velocities with measurements of retinal vessel diameters and blood oxygen saturation. METHODS: Sixteen eyes in 16 healthy volunteers were studied at two...... measurements may provide comprehensive information about retinal metabolism....

  16. Is there a relationship between the diameter of the inferior vena cava ...

    African Journals Online (AJOL)

    2015-04-12

    Apr 12, 2015 ... Aim: This study investigated whether a correlation exists between haemodynamic parameters of critically ill patients and the ... were performed and significant relationship was found between the EAP diameter with haemoglobin (Hmg), haemotocrit ..... Doctors (ATLS), Student Course Manuel. 7th ed.

  17. The Effect of Sunlight in Parenchyma Pith Cells Diameter of Manihot esculenta

    Science.gov (United States)

    Susanti, D.; Aziz, D. N.; Astuti, W.; Nuraeni, E.

    2017-03-01

    Sunlight is one of the factors that effect on the grow of a plant. Manihot esculenta is one of the plants that easily found in Indonesia because its role as staple food. The aim of this research is to know the correlation between sunlight the grow of parenchyma pith cells diameter of Manihot esculenta. Independent variable in this research is sunlight, and dependent variable is the parenchyma pith cells diameter of Manihot esculenta. Data was collected is in qualitative and quantitative form. Qualitative data gotten gained by morphology observation. The parenchyma pith cells of Manihot esculenta that is affected by sunlight in 1310 x 10 Lux, morphologically has hexagon, cell walls thick, solid state, and regular composition. Meanwhile, the parenchyma pith cells that has less sunlight (363 x 10 Lux) has a hexagon shape, thin cell walls thin, soft state, and irregular composition. Qualitative data suported by quantitative data. The size of parenchyma pith cells diameter that is affected by sunlight in 1310 x 10 Lux 96,4 µm. While, the stem parenchyma pith cells diameter empulur that has less sunlight (363 x 10 Lux) is 129,8 µm.

  18. Fabrication of an Optical Fiber Micro-Sphere with a Diameter of Several Tens of Micrometers

    Directory of Open Access Journals (Sweden)

    Huijuan Yu

    2014-06-01

    Full Text Available A new method to fabricate an integrated optical fiber micro-sphere with a diameter within 100 µm, based on the optical fiber tapering technique and the Taguchi method is proposed. Using a 125 µm diameter single-mode (SM optical fiber, an optical fiber taper with a cone angle is formed with the tapering technique, and the fabrication optimization of a micro-sphere with a diameter of less than 100 µm is achieved using the Taguchi method. The optimum combination of process factors levels is obtained, and the signal-to-noise ratio (SNR of three quality evaluation parameters and the significance of each process factors influencing them are selected as the two standards. Using the minimum zone method (MZM to evaluate the quality of the fabricated optical fiber micro-sphere, a three-dimensional (3D numerical fitting image of its surface profile and the true sphericity are subsequently realized. From the results, an optical fiber micro-sphere with a two-dimensional (2D diameter less than 80 µm, 2D roundness error less than 0.70 µm, 2D offset distance between the micro-sphere center and the fiber stylus central line less than 0.65 µm, and true sphericity of about 0.5 µm, is fabricated.

  19. The impact of baseline diameter on flow-mediated dilation differs in young and older humans.

    NARCIS (Netherlands)

    Thijssen, D.H.J.; Bemmel, M.M. van; Bullens, L.M.; Dawson, E.A.; Hopkins, N.D.; Tinken, T.M.; Black, M.A.; Hopman, M.T.E.; Cable, N.T.; Green, D.J.

    2008-01-01

    Flow-mediated dilation (FMD) has become a commonly applied approach for the assessment of vascular function and health, but methods used to calculate FMD differ between studies. For example, the baseline diameter used as a benchmark is sometimes assessed before cuff inflation, whereas others use the

  20. Abdominal diameters as indicators of visceral fat : comparison between magnetic resonance imaging and anthropometry

    NARCIS (Netherlands)

    van der Kooy, K; Leenen, R; Seidell, J C; Deurenberg, P.; Visser, M

    The aim of the present study was to investigate the usefulness of abdominal diameters to indicate visceral fat, their relationship with serum lipids and their capability of detecting changes in visceral fat. Before and after weight loss, visceral and subcutaneous fat, and the sagittal and transverse

  1. Carbon nanotube diameter selection by pretreatment of metal catalysts on surfaces

    Science.gov (United States)

    Hauge, Robert H [Houston, TX; Xu, Ya-Qiong [Houston, TX; Shan, Hongwei [Houston, TX; Nicholas, Nolan Walker [South Charleston, WV; Kim, Myung Jong [Houston, TX; Schmidt, Howard K [Cypress, TX; Kittrell, W Carter [Houston, TX

    2012-02-28

    A new and useful nanotube growth substrate conditioning processes is herein disclosed that allows the growth of vertical arrays of carbon nanotubes where the average diameter of the nanotubes can be selected and/or controlled as compared to the prior art.

  2. Quantitative measurement of changes in retinal vessel diameter in ocular fundus images

    DEFF Research Database (Denmark)

    Pedersen, Lars; Grunkin, Michael; Ersbøll, Bjarne Kjær

    2000-01-01

    The change in diameter of retinal vessels as a function of increasing distance to the optic disc is believed to be indicative of the risk level of various vascular diseases such as generalised arteriosclerosis and Diabetes Mellitus. In particular, focal arteriolar narrowing (FAN) is considered re...

  3. Simplified Equations to Estimate Flushline Diameter for Subsurface Drip Irrigation Systems

    Science.gov (United States)

    A formulation of the Hazen-Williams equation is typically used to determine the diameter of the common flushline that is often used at the distal end of subsurface drip irrigation systems to aid in joint flushing of a group of driplines. Although this method is accurate, its usage is not intuitive a...

  4. The Palm-Heart Diameter: A Prospective Simple Screening Tool for Identifying Heart Enlargement

    Directory of Open Access Journals (Sweden)

    Adegbenro Omotuyi John Fakoya

    2017-11-01

    CONCLUSION: This study establishes the correlation between the palm and heart diameters. Since the heart tissue and the upper limb share a similar embryonic origin, being the mesoderm, this study prospects the fact that heart enlargement could be preliminarily identified by measuring the size of the hand.

  5. Optimum diameter of a circulating fluidised bed combustor with negative wall heat flux

    CSIR Research Space (South Africa)

    Baloyi, J

    2015-07-01

    Full Text Available process was modelled by a non-premixed combustion model, with a P1 radiation model. Simulations were run using a steady Reynolds averaged Navier Stokes model. The analytical expression predicted the optimum diameter that results in minimum...

  6. Stability of diameter distributions in a managed uneven-aged oak forest in the Ozark Highlands

    Science.gov (United States)

    Zhiming Wang; Paul S. Johnson; H. E. Garrett; Stephen R. Shifley

    1997-01-01

    We studied a privately owned 156,000-acre oak-dominated forest in the Ozark Highlands of southern Missouri. The forest has been managed by the single-tree selection method since 1952. Using 40 years of continuous forest inventory records, we analyzed the stability of the shape of tree diameter distributions at the forest-wide scale. Results show that for trees ...

  7. A Simple Method for Measuring the Verticality of Small-Diameter Driven Wells

    DEFF Research Database (Denmark)

    Kjeldsen, Peter; Skov, Bent

    1994-01-01

    The presence of stones, solid waste, and other obstructions can deflect small-diameter driven wells during installation, leading to deviations of the well from its intended position. This could lead to erroneous results, especially for measurements of ground water levels by water level meters...... ground water flow directions....

  8. Analysis of the horizontal corneal diameter, central corneal thickness, and axial length in premature infants

    Directory of Open Access Journals (Sweden)

    Ozdemir Ozdemir

    2014-08-01

    Full Text Available Purpose: To determine the horizontal corneal diameter, central corneal thickness, and axial length in premature infants. Methods: Infants with a birth weight of less than 2,500 g or with a gestation period of less than 36 weeks were included in the study. Infants with retinopathy of prematurity (ROP were allocated to Group 1 (n=138, while those without ROP were allocated to Group 2 (n=236. All infants underwent a complete ophthalmologic examination, including corneal diameter measurements, pachymetry, biometry, and fundoscopy. Between-group comparisons of horizontal corneal diameter, central corneal thickness, and axial lengths were performed. Independent sample t-tests were used for statistical analysis. Results: Data was obtained from 374 eyes of 187 infants (102 female, 85 male. The mean gestational age at birth was 30.7 ± 2.7 weeks (range 25-36 weeks, the mean birth weight was 1,514 ± 533.3 g (range 750-1,970 g, and the mean postmenstrual age at examination was 40.0 ± 4.8 weeks. The mean gestational age and the mean birth weight of Group 1 were statistically lower than Group 2 (p0.05. Conclusions: The presence of ROP in premature infants does not alter the horizontal corneal diameter, central corneal thickness, or axial length.

  9. Magnetomotive forming for precision sizing and joining of large-diameter tubes

    Science.gov (United States)

    Bennight, J. D.; Schwinghamer, R. J.

    1969-01-01

    Portable electromagnetic coil enables high precision expansion or constriction and joining of large diameter metal tubes. A nonconducting mandrel or forming die is used on the side of the tubes wall opposite the coil. The coil is insulated from the tube by a thin plastic sleeve.

  10. Effect of twine diameter on fishing power of experimental gill nets used in Greenland waters

    DEFF Research Database (Denmark)

    Hovgård, Holger

    1996-01-01

    The relative fishing powers of experimental gill nets were estimated for shorthorn sculpin (Myoxocephalus scorpius), Greenland cod (Gadus ogac), and Atlantic cod (Gadus morhua). The results suggested that fishing power was negatively correlated to the ratio between twine diameter and mesh size...

  11. Retinal Vessel Diameters and Risk of Impaired Fasting Glucose or Diabetes

    NARCIS (Netherlands)

    Ikram, M.K.; Janssen, J.A.M.J.L.; Roos, A.M.E.; Rietveld, I.; Witteman, J.C.M.; Breteler, M.M.B.; Hofman, A.; Duijn, C.M. van; de Jong, P.T.V.M.

    2006-01-01

    The association between a smaller retinal arteriolar-to-venular ratio (AVR) and incident diabetes may be due to arteriolar narrowing, venular dilatation, or both. We investigated associations between baseline vessel diameters and incident impaired fasting glucose or diabetes in a population-based

  12. Maximum tumor diameter is not an independent prognostic factor in high-risk localized prostate cancer

    NARCIS (Netherlands)

    Oort, van I.M.; Witjes, J.A.; Kok, D.E.G.; Kiemeney, L.A.; Hulsbergen-van de Kaa, C.A.

    2008-01-01

    Previous studies suggest that maximum tumor diameter (MTD) is a predictor of recurrence in prostate cancer (PC). This study investigates the prognostic value of MTD for biochemical recurrence (BCR) in patients with PC, after radical prostatectomy (RP), with emphasis on high-risk localized prostate

  13. Maximum tumor diameter is not an independent prognostic factor in high-risk localized prostate cancer.

    NARCIS (Netherlands)

    Oort, I.M. van; Witjes, J.A.M.; Kok, D.E.; Kiemeney, L.A.L.M.; Hulsbergen- van de Kaa, C.A.

    2008-01-01

    OBJECTIVES: Previous studies suggest that maximum tumor diameter (MTD) is a predictor of recurrence in prostate cancer (PC). This study investigates the prognostic value of MTD for biochemical recurrence (BCR) in patients with PC, after radical prostatectomy (RP), with emphasis on high-risk

  14. Production of vertical arrays of small diameter single-walled carbon nanotubes

    Science.gov (United States)

    Hauge, Robert H; Xu, Ya-Qiong

    2013-08-13

    A hot filament chemical vapor deposition method has been developed to grow at least one vertical single-walled carbon nanotube (SWNT). In general, various embodiments of the present invention disclose novel processes for growing and/or producing enhanced nanotube carpets with decreased diameters as compared to the prior art.

  15. Effect of post diameter and cement thickness on bond strength of fiber posts

    NARCIS (Netherlands)

    Mirmohammadi, H.; Gerges, E.; Salameh, Z.; Wesselink, P.R.

    2013-01-01

    Objective: This study evaluated the effects of different post diameter and oversized post spaces on the push-out bond strength of a fiber post to dentin. Method and Materials: Fifty extracted human maxillary central incisors and canines were divided into five groups and submitted to the push-out

  16. Effect of diameter of metal nanowires on pool boiling heat transfer with FC-72

    Science.gov (United States)

    Kumar G., Udaya; S., Suresh; M. R., Thansekhar; Babu P., Dinesh

    2017-11-01

    Effect of varying diameter of metal nanowires on pool boiling heat transfer performance is presented in this study. Copper nanowires (CuNWs) of four different diameters (∼35 nm, ∼70 nm, ∼130 nm and ∼200 nm) were grown directly on copper specimen using template-based electrodeposition technique. Both critical heat flux (CHF) and boiling heat transfer coefficient (h) were found to be improved in surfaces with nanowires as compared to the bare copper surface. Moreover, both the parameters were found to increase with increasing diameter of the nanowires. The percentage increases observed in CHF for the samples with nanowires were 38.37%, 40.16%, 48.48% and 45.57% whereas the percentage increase in the heat transfer coefficient were 86.36%, 95.45%, 184.1% and 131.82% respectively as compared to the bare copper surface. Important reasons believed for this enhancement were improvement in micron scale cavity density and cavity size which arises as a result of the coagulation and grouping of nanowires during the drying process. In addition to this, superhydrophilic nature, capillary effect, and enhanced bubble dynamics parameters (bubble frequency, bubble departure diameter, and nucleation site density) were found to be the concurring mechanisms responsible for this enhancement in heat transfer performance. Qualitative bubble dynamics analysis was done for the surfaces involved and the visual observations are provided to support the results presented and discussed.

  17. 77 FR 37873 - Small Diameter Graphite Electrodes From the People's Republic of China: Initiation of...

    Science.gov (United States)

    2012-06-25

    ... Company (collectively, Jilin Carbon), as companies engaging in this practice. See SQR at 2. The... process as subject SDGEs and the slight increase of the diameter does not significantly change the SDGE's bulk density, specific electrical resistance, coefficient of thermal expansion, or flexural strength...

  18. Quantitative Measurement of Changes in Retinal Vessel Diameter in Ocular Fundus Images

    DEFF Research Database (Denmark)

    Pedersen, Lars; Grunkin, Michael; Ersbøll, Bjarne Kjær

    1999-01-01

    The Change in diameter of retinal vessels as a funcion of increasing distance to the optic disc is believed to be indicative of the risk level of various vascular diseases such as generalised arteriosclerosis and Diabetes Mellitus. In particular, Focal Arteriolar Narrowing (FAN) is considered...

  19. Characterization of wood strands from young, small-diameter Douglas-fir and western hemlock trees

    Science.gov (United States)

    Vikram Yadama; Eini C. Lowell; Christopher E. Langum

    2012-01-01

    Tensile properties of strands processed from small-diameter Douglas-fir and western hemlock trees grown on the Washington coast were analyzed and effects of location within the tree on properties was examined. Reduction factors for strand properties relative to small, clear solid wood specimen properties were determined by correlating strand properties to previously...

  20. Femoral head diameter in subcapital fracture of the femur in Ibadan, Nigeria.

    Science.gov (United States)

    Ogunlade, S O; Omololu, A B; Alonge, T O; Obajimi, M O

    2004-09-01

    Subcapital fracture of the femur is common in the elderly patients though the incidence is less in our environment than in the western world. Primary prosthetic replacement is the method of treatment in the majority of the patients. To facilitate this, a foreknowledge of the femoral head diameter is necessary. To determine the diameter of the femoral head and its magnification on radiograph among patients with hip fractures seen in South-West Nigeria, all patients with subcapital fracture of the neck of femur seen between March 1997 and February 2002 were included in the study. The femoral heads were measured on the radiographic film using a transparent ruler and after extraction of the femoral head during surgery using callipers. There were 25 patients in all, the mean age of patients was 73.2 years. Fall at home accounted for 70% of the cases. The femoral head diameter was between 42 mm and 50 mm in 92% of patients while magnification of femoral head diameter on radiograph was 10-14% in 92% of cases. The usaof 10-14% magnification of femoral head on radiograph would help the surgeon determine the size of prosthetic head before commencement of surgery.

  1. Nonuniform Internal Structure of Fibrin Fibers: Protein Density and Bond Density Strongly Decrease with Increasing Diameter

    Directory of Open Access Journals (Sweden)

    Wei Li

    2017-01-01

    Full Text Available The major structural component of a blood clot is a meshwork of fibrin fibers. It has long been thought that the internal structure of fibrin fibers is homogeneous; that is, the protein density and the bond density between protofibrils are uniform and do not depend on fiber diameter. We performed experiments to investigate the internal structure of fibrin fibers. We formed fibrin fibers with fluorescently labeled fibrinogen and determined the light intensity of a fiber, I, as a function of fiber diameter, D. The intensity and, thus, the total number of fibrin molecules in a cross-section scaled as D1.4. This means that the protein density (fibrin per cross-sectional area, ρp, is not homogeneous but instead strongly decreases with fiber diameter as D-0.6. Thinner fibers are denser than thicker fibers. We also determined Young’s modulus, Y, as a function of fiber diameter. Y decreased strongly with increasing D; Y scaled as D-1.5. This implies that the bond density, ρb, also scales as D-1.5. Thinner fibers are stiffer than thicker fibers. Our data suggest that fibrin fibers have a dense, well-connected core and a sparse, loosely connected periphery. In contrast, electrospun fibrinogen fibers, used as a control, have a homogeneous cross-section.

  2. Use of a coherent fiber bundle for multi-diameter single fiber reflectance spectroscopy

    NARCIS (Netherlands)

    C.L. Hoy (C.); U.A. Gamm; H.J.C.M. Sterenborg (Dick); D.J. Robinson (Dominic); A. Amelink (Arjen)

    2012-01-01

    textabstractMulti-diameter single fiber reflectance (MDSFR) spectroscopy enables quantitative measurement of tissue optical properties, including the reduced scattering coefficient and the phase function parameter γHowever, the accuracy and speed of the procedure are currently limited by the need

  3. Biomechanical effects of implant number and diameter on stress distributions in maxillary implant-supported overdentures.

    Science.gov (United States)

    Dimililer, Gizem; Kücükkurt, Sercan; Cetiner, Sedat

    2017-05-26

    Implant-supported overdentures (ISOs) are considered a good alternative to conventional removable dentures. However, varying rates of failure have been reported in some clinical studies. Excessive stress on surrounding tissues is one of the possible causes of implant failure. As stress is transmitted to the bone through the implant, careful planning, correct number of implants, and implant positioning are keys to ensuring appropriate stress distribution. However, research of the optimal number of implants necessary to support a maxillary ISO is insufficient. The purpose of this in vitro finite element study was to determine the optimal implant location, number, and diameter to support a maxillary ISO. Three-dimensional models of an atrophic maxilla, dental implants, and ball attachments were modeled, and different loading conditions were applied to simulate realistic conditions. Six models with different numbers and diameters of implants, including mini-dental implants and differently located implants, were formed, and stress values were compared by implementing a finite element analysis. The study showed that, as the implant number increased, decreased stress values were observed in periimplant bone and implants in the maxillary ISO prosthesis. However, changes in implant diameter had no significant effect on stresses. Increasing the implant diameter was not advantageous; the use of mini-dental implants may be a viable alternative method. However, using 4 implants for maxillary ISOs is indicated. Copyright © 2017 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  4. Diameter grouping in bulk samples of single-walled carbon nanotubes from optical absorption spectroscopy

    NARCIS (Netherlands)

    Golden, M.S.; Fink, J.; Dunsch, L.; Bauer, H.-D.; Reibold, M.; Knupfer, M.; Friedlein, R.; Pichler, T.; Jost, O.

    1999-01-01

    The influence of the synthesis parameters on the mean characteristics of single-wall carbon nanotubes in soot produced by the laser vaporization of graphite has been analyzed using optical absorption spectroscopy. The abundance and mean diameter of the nanotubes were found to be most influenced by

  5. Dominant height-based height-diameter equations for trees in southern Indiana

    Science.gov (United States)

    John A., Jr. Kershaw; Robert C. Morrissey; Douglass F. Jacobs; John R. Seifert; James B. McCarter

    2008-01-01

    Height-diameter equations are developed based on dominant tree data collected in 1986 in 8- to 17-year-old clearcuts and the phase 2 Forest Inventory and Analysis plots on the Hoosier National Forest in south central Indiana. Two equation forms are explored: the basic, three-parameter Chapman-Richards function, and a modification of the three-parameter equation...

  6. Corneal diameters in infants born in two hospitals in Ibadan, Nigeria ...

    African Journals Online (AJOL)

    Objectives: To measure the horizontal corneal diameters in infants at birth and compare with values reported in other studies. Design: A cross-sectional hospital based study. Subjects: All the healthy infants born within the period of one month in these hospitals were eligible for enrolment into the study. Horizontal corneal ...

  7. A semi-empirical model for predicting crown diameter of cedrela ...

    African Journals Online (AJOL)

    A semi-empirical model relating age and breast height has been developed to predict individual tree crown diameter for Cedrela odorata (L) plantation in the moist evergreen forest zones of Ghana. The model was based on field records of 269 trees, and could determine the crown cover dynamics, forecast time of canopy ...

  8. Damage detection of satellite structures by optical fiber with small diameter

    Science.gov (United States)

    Kabashima, Shigenori; Ozaki, Tsuyoshi; Takeda, Nobuo

    2000-06-01

    Although there have been many researches concerning health monitoring system in the aerospace field, most of such researches relate to aircraft; there are only few that relate to satellite structures. This research first points out merit of the health monitoring system. The health monitoring system usually utilizes optical fiber sensor of which the diameter is 125 micrometer. However, such fiber sensors tend to be perceived as obstacles within the structure, which affects the soundness of the structure. This is especially the case in satellite structure, which utilizes especially thin composite laminates. In view of this problem, this study utilizes small diameter optical fiber, which is less likely to affect the soundness of the structure. The optical fiber is 40 micrometer in cladding diameter, and is embedded in the composite laminate structure. The structure and the optical fiber have been visually observed. Also, tensile test has been conducted on the structure. The result of the study indicates that the small diameter optical fiber can be embedded in the structure without affecting the soundness of the structure. The study further found that compressive destruction of a face sheet of a honeycomb sandwich panel having thin face sheets can be detected by utilizing this optical fiber.

  9. Aerodynamic performance of a 5-metre-diameter Darrieus turbine with extruded aluminum NACA-0015 blades

    Science.gov (United States)

    Sheldahl, R. E.; Klimas, P. C.; Feltz, L. V.

    1980-03-01

    A 5 metric-diameter vertical-axis wind turbine with extruded aluminum blades of NACA-0015 airfoil cross section was tested. Several turbine rotational speeds are presented and compared with earlier test results. Performance comparison is made with a vortex/lifting line computational code.

  10. Prediction of wood Quality in Small-Diameter Douglas-Fir using site and Stand Characteristics

    Science.gov (United States)

    C.D. Morrow; T.M. Gorman; J.W. Evans; D.E. Kretschmann; C.A. Hatfield

    2013-01-01

    Standing stress wave measurements were taken on 274 small-diameter Douglas-fir trees in western Montana. Stand, site, and soil measurements collected in the field and remotely through geographical information system (GIS) data layers were used to model dynamic modulus of elasticity (DMOE) in those trees. The best fit linear model developed resulted in an adjusted

  11. Lumbar spinal canal MRI diameter is smaller in herniated disc cauda equina syndrome patients.

    Science.gov (United States)

    Korse, Nina S; Kruit, Mark C; Peul, Wilco C; Vleggeert-Lankamp, Carmen L A

    2017-01-01

    Correlation between magnetic resonance imaging (MRI) and clinical features in cauda equina syndrome (CES) is unknown; nor is known whether there are differences in MRI spinal canal size between lumbar herniated disc patients with CES versus lumbar herniated discs patients without CES, operated for sciatica. The aims of this study are 1) evaluating the association of MRI features with clinical presentation and outcome of CES and 2) comparing lumbar spinal canal diameters of lumbar herniated disc patients with CES versus lumbar herniated disc patients without CES, operated because of sciatica. MRIs of CES patients were assessed for the following features: level of disc lesion, type (uni- or bilateral) and severity of caudal compression. Pre- and postoperative clinical features (micturition dysfunction, defecation dysfunction, altered sensation of the saddle area) were retrieved from the medical files. In addition, anteroposterior (AP) lumbar spinal canal diameters of CES patients were measured at MRI. AP diameters of lumbar herniated disc patients without CES, operated for sciatica, were measured for comparison. 48 CES patients were included. At MRI, bilateral compression was seen in 82%; complete caudal compression in 29%. MRI features were not associated with clinical presentation nor outcome. AP diameter was measured for 26 CES patients and for 31 lumbar herniated disc patients without CES, operated for sciatica. Comparison displayed a significant smaller AP diameter of the lumbar spinal canal in CES patients (largest p = 0.002). Compared to average diameters in literature, diameters of CES patients were significantly more often below average than that of the sciatica patients (largest p = 0.021). This is the first study demonstrating differences in lumbar spinal canal size between lumbar herniated disc patients with CES and lumbar herniated disc patients without CES, operated for sciatica. This finding might imply that lumbar herniated disc patients with a

  12. Lumbar spinal canal MRI diameter is smaller in herniated disc cauda equina syndrome patients.

    Directory of Open Access Journals (Sweden)

    Nina S Korse

    Full Text Available Correlation between magnetic resonance imaging (MRI and clinical features in cauda equina syndrome (CES is unknown; nor is known whether there are differences in MRI spinal canal size between lumbar herniated disc patients with CES versus lumbar herniated discs patients without CES, operated for sciatica. The aims of this study are 1 evaluating the association of MRI features with clinical presentation and outcome of CES and 2 comparing lumbar spinal canal diameters of lumbar herniated disc patients with CES versus lumbar herniated disc patients without CES, operated because of sciatica.MRIs of CES patients were assessed for the following features: level of disc lesion, type (uni- or bilateral and severity of caudal compression. Pre- and postoperative clinical features (micturition dysfunction, defecation dysfunction, altered sensation of the saddle area were retrieved from the medical files. In addition, anteroposterior (AP lumbar spinal canal diameters of CES patients were measured at MRI. AP diameters of lumbar herniated disc patients without CES, operated for sciatica, were measured for comparison.48 CES patients were included. At MRI, bilateral compression was seen in 82%; complete caudal compression in 29%. MRI features were not associated with clinical presentation nor outcome. AP diameter was measured for 26 CES patients and for 31 lumbar herniated disc patients without CES, operated for sciatica. Comparison displayed a significant smaller AP diameter of the lumbar spinal canal in CES patients (largest p = 0.002. Compared to average diameters in literature, diameters of CES patients were significantly more often below average than that of the sciatica patients (largest p = 0.021.This is the first study demonstrating differences in lumbar spinal canal size between lumbar herniated disc patients with CES and lumbar herniated disc patients without CES, operated for sciatica. This finding might imply that lumbar herniated disc patients with

  13. [Relationships between coefficient of variation of diameter and height and competition index of main coniferous trees in Changbai Mountains].

    Science.gov (United States)

    Zhao, Jun-Hui; Kang, Xin-Gang; Zhang, Hui-Dong; Liu, Yan

    2009-08-01

    A total of 1139 trees from 8 clear-cut stands dominated by fir, spruce, and pine in the Changbai Mountains were selected to study the relationships between the coefficient of variation of diameter and height and the competition index of the three main coniferous tree species in the Mountains. For the test tree species, the variation of height vs. diameter class was relatively small, while the variations of diameter and height vs. age class were larger, with the largest coefficient of variation of diameter vs. age class. The traditional height-diameter models could better reflect the real growth of trees, whereas the diameter-age or height-age models were not good enough. Competition was the main factor inducing the variations of tree diameter and height, suggesting that incorporating the competition index to the traditional models of tree growth and height could improve the model accuracy significantly.

  14. Correlation between the cryosurvival, cell number and diameter in bovine in vitro produced embryos.

    Science.gov (United States)

    Kocyigit, Alper; Cevik, Mesut

    2016-10-01

    The selection of quality embryos is a prerequisite of cryopreservation process. Present study was conducted to examine the correlation between the diameter and cryotolerance, on the cell number of the cryopreserved embryos. The blastocyst stage embryos were collected at culture days 7-9, evaluated morphologically under a microscope and divided according to the diameter into three groups: Group 1; (larger than 150 μm), Group 2; (diameter of 100-150 μm), Group 3; (smaller than 100 μm). Blastocysts were vitrified-thawed using the classical vitrification method and then cultured in SOF medium drops at 24 h. Blastocysts were considered viable if they re-expanded or hatched from the zona pellucidae. Finally re-expanded blastocysts from the Group 1 and Group 2 to determine the differential count of cells in the ICM and TE. The re-expansion ability of blastocysts 100-150 μm in diameter (69.56%) was significantly higher than other groups (52.17 and 47.36%). The value of the correlation coefficient between the re-expansion rate and cell number of blastocysts in the group 2 (r = 0.784) tended to be higher than that in the group 1 (r = 0.512) and group 3 (r = 0.491) (p < 0.05). For ICM/total cell ratio yield group 2 embryos showed higher rate (0.28), compared to the other groups (0.19 and 0.16). In conclusion, the present study demonstrates that the correlation between diameter of embryos and their cryosurvival based on re-expansion ability and cell allocation. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. Engineering of an E. coli outer membrane protein FhuA with increased channel diameter

    Directory of Open Access Journals (Sweden)

    Dworeck Tamara

    2011-08-01

    Full Text Available Abstract Background Channel proteins like FhuA can be an alternative to artificial chemically synthesized nanopores. To reach such goals, channel proteins must be flexible enough to be modified in their geometry, i.e. length and diameter. As continuation of a previous study in which we addressed the lengthening of the channel, here we report the increasing of the channel diameter by genetic engineering. Results The FhuA Δ1-159 diameter increase has been obtained by doubling the amino acid sequence of the first two N-terminal β-strands, resulting in variant FhuA Δ1-159 Exp. The total number of β-strands increased from 22 to 24 and the channel surface area is expected to increase by ~16%. The secondary structure analysis by circular dichroism (CD spectroscopy shows a high β-sheet content, suggesting the correct folding of FhuA Δ1-159 Exp. To further prove the FhuA Δ1-159 Exp channel functionality, kinetic measurement using the HRP-TMB assay (HRP = Horse Radish Peroxidase, TMB = 3,3',5,5'-tetramethylbenzidine were conducted. The results indicated a 17% faster diffusion kinetic for FhuA Δ1-159 Exp as compared to FhuA Δ1-159, well correlated to the expected channel surface area increase of ~16%. Conclusion In this study using a simple "semi rational" approach the FhuA Δ1-159 diameter was enlarged. By combining the actual results with the previous ones on the FhuA Δ1-159 lengthening a new set of synthetic nanochannels with desired lengths and diameters can be produced, broadening the FhuA Δ1-159 applications. As large scale protein production is possible our approach can give a contribution to nanochannel industrial applications.

  16. Intermediate Term Outcomes of Early Posttrabeculectomy Bleb Leaks Managed by Large Diameter Soft Bandage Contact Lens.

    Science.gov (United States)

    Gollakota, SriRamani; Garudadri, Chandra S; Mohamed, Ashik; Senthil, Sirisha

    2017-09-01

    To study the outcomes of large diameter soft bandage contact lens (BCL) in managing early trabeculectomy bleb leak. Of 972 eyes that underwent fornix-based trabeculectomy between 2011 and 2015, 19 eyes with bleb leak with at least 1 year follow-up were eligible. Bleb leak was conservatively managed using large diameter BCL (≥15.5 mm in diameter). Success was defined as complete, if bleb leak resolved and the intraocular pressure (IOP) was ≥5 and ≤18 mm Hg with no additional antiglaucoma medication and failure if surgical intervention was needed. Mean age (±SD) of subjects was 43.5±11.9 years. Mitomycin C was used in 15/19 eyes. Median time (interquartile range) from trabeculectomy to bleb leak was 9 days (interquartile range: 8 to 19 d). Bleb leak was treated with 15.5 mm BCL in 16 eyes and 17 mm lens in 3 eyes. Bleb leak resolved with BCL in 17 [89.5%; 95% confidence interval (95% CI), 68.6-97] and 2 eyes (10.5%; 95% CI, 2-31) required bleb resuturing. Mean duration of BCL wear for bleb leak resolution was 23.7±8.9 days. Mean IOP increased from 5.8±2.7 to 12.5±3.1 mm Hg after resolution of bleb leak (P<0.05). At 16 months, complete success probability of trabeculectomy was 89.4% (95% CI, 75.6%-100%). Large diameter BCL was effective in the management of early bleb leak with good intermediate term success for IOP control. We suggest a trial of soft contact lens of appropriate diameter to manage early bleb leaks, before planning any invasive intervention.

  17. Building America Case Study: High-Velocity Small-Diameter Duct System, Pittsburgh, Pennsylvania

    Energy Technology Data Exchange (ETDEWEB)

    A. Poerschke

    2017-04-01

    This study tests the performance of a variable airflow small-diameter duct heating, ventilation, and air conditioning (HVAC) system in a new construction unoccupied low-load test house in Pittsburgh, Pennsylvania. The duct system was installed entirely in conditioned space and was operated from the winter through summer seasons. Measurements were collected on the in-room temperatures and energy consumed by the air handler and heat pump unit. Operation modes with three different volumes of airflow were compared to determine the ideal airflow scenario that maximizes room-to-room thermal uniformity while minimizing fan energy consumption. Black felt infrared imagery was used as a measure of diffuser throw and in-room air mixing. Measured results indicate the small-diameter, high velocity airflow system can provide comfort under some conditions. Solar heat gains resulted in southern rooms drifting beyond acceptable temperature limits. Insufficient airflow to some bedrooms also resulted in periods of potential discomfort. Homebuilders or HVAC contractors can use these results to assess whether this space conditioning strategy is an attractive alternative to a traditional duct system. The team performed a cost analysis of two duct system configurations: (1) a conventional diameter and velocity duct system, and (2) the small-diameter duct system. This work applies to both new and retrofit homes that have achieved a low heating and cooling density either by energy conservation or by operation in a mild climate with few heating or cooling degree days. Guidance is provided on cost trade-offs between the conventional duct system and the small-diameter duct system.

  18. Critical diameter for the transmission of a detonation wave into a porous medium

    Energy Technology Data Exchange (ETDEWEB)

    Makris, A.; Oh, T.J.; Lee, J.H.S.; Knystautas, R. [McGill Univ., Montreal, Quebec (Canada)

    1994-12-31

    An experimental investigation has been undertaken to elucidate the existence of a critical diameter for the transmission of gaseous detonation into a porous medium. A Chapman-Jouguet (CJ) detonation is first established in a tube and allowed to transmit through an orifice plate into a porous medium comprised of inert spheres of equal diameter. It is found that detonation can successfully transmit past the orifice for diameters much smaller than the normal critical diameter (d{sub c}) of the mixture. An immediate transition from detonation to quasi-detonation normally takes place upon wave entry in the porous medium. Failure of detonation is observed to take place downstream of the orifice in the near-limit regime and is followed by deflagration to detonation transition (DDT) within the porous medium. Wave velocities in the porous medium are found to be identical to the corresponding values measured for direct transmission (without an orifice). For subcritical conditions, there is complete quenching of combustion in the pores. The critical composition (lean and rich) for mixtures with high activation energy is found to be practically the same as the propagation limits in the porous medium without an orifice. This indicates that the phenomenon is governed by the smallest physical dimension of the pore size, and thus a local failure mechanism exists. In mixtures highly diluted with argon, i.e., (C{sub 2}H{sub 2}-O{sub 2}) + 75% Ar, which have, a lower activation energy and for which the ``d{sub c} = 13{lambda}`` correlation (where {lambda} is the cell size) is known to break down, the critical composition appears to depend on the orifice diameter. The orifice now introduces a larger controlling length scale at the limits compared to the pore size, indicating that a global failure mechanism may prevail for such mixtures. Present findings are consistent with a local and global failure mechanism for normal detonation failure recently proposed by Lee.

  19. Measured Performance of a Varied Airflow Small-Diameter Duct System

    Energy Technology Data Exchange (ETDEWEB)

    Poerschke, Andrew [IBACOS, Inc., Pittsburgh, PA (United States)

    2017-03-01

    This study tests the performance of a variable airflow small-diameter duct heating, ventilation, and air conditioning (HVAC) system in a new construction unoccupied low-load test house in Pittsburgh, Pennsylvania. The duct system was installed entirely in conditioned space and was operated from the winter through summer seasons. Measurements were collected on the in-room temperatures and energy consumed by the air handler and heat pump unit. Operation modes with three different volumes of airflow were compared to determine the ideal airflow scenario that maximizes room-to-room thermal uniformity while minimizing fan energy consumption. Black felt infrared imagery was used as a measure of diffuser throw and in-room air mixing. Measured results indicate the small-diameter, high velocity airflow system can provide comfort under some conditions. Solar heat gains resulted in southern rooms drifting beyond acceptable temperature limits. Insufficient airflow to some bedrooms also resulted in periods of potential discomfort. Homebuilders or HVAC contractors can use these results to assess whether this space conditioning strategy is an attractive alternative to a traditional duct system. The team performed a cost analysis of two duct system configurations: (1) a conventional diameter and velocity duct system, and (2) the small-diameter duct system. This work applies to both new and retrofit homes that have achieved a low heating and cooling density either by energy conservation or by operation in a mild climate with few heating or cooling degree days. Guidance is provided on cost trade-offs between the conventional duct system and the small-diameter duct system.

  20. The blood pressure-induced diameter response of retinal arterioles decreases with increasing diabetic maculopathy.

    Science.gov (United States)

    Frederiksen, Christian Alcaraz; Jeppesen, Peter; Knudsen, Søren Tang; Poulsen, Per Løgstrup; Mogensen, Carl Erik; Bek, Toke

    2006-10-01

    The aim of the study was to compare the diameter response of retinal arterioles and retinal thickness in patients with different stages of diabetic maculopathy during an increase in the arterial blood pressure. Four groups each consisting of 19 individuals were studied. Group A consisted of normal individuals and groups B-D consisted of type 2 diabetic patients matched for diabetes duration, age, and gender, and characterized by: Group B no retinopathy, Group C mild retinopathy, Group D maculopathy not requiring laser treatment. The diameter changes of a large retinal arteriole were measured using the Retinal Vessel Analyzer (RVA, Imedos, Germany) before, during, and after an increase in the blood pressure induced by isometric exercise. Additionally, the retinal thickness was measured using optical coherence tomography scanning. The arterioles contracted during isometric exercise in normal persons (diameter response: -0.70+/-0.48%) and in patients with no retinopathy (-1.15+/-0.44%), but dilated in patients with mild retinopathy (0.41+/-0.49%) and diabetic maculopathy (0.54+/-0.44%), p=0.01. Retinal thickness was normal in Group A (260+/-5.0 microm), Group B (257+/-4.5 microm), and Group C (253+/-4.4 microm), but was significantly (p=0.006) increased in Group D (279+/-5.3 microm). The diameter response was reduced in type 2 diabetic patients with retinopathy, whereas retinal thickness was increased in patients with diabetic maculopathy. This suggests that impairment of diameter response in retinal arterioles precedes the development of diabetic macular edema.

  1. A comparison of basilar artery diameters measured by T2WI and TOF MR angiography.

    Science.gov (United States)

    Çelebioğlu, Emre Can; Aldur, Muhammed Mustafa; Tunali, Selcuk; Hayran, Murvet; Taşçıoğlu, Ayşe Beliz; Sargon, F Mustafa

    2017-11-01

    The purpose of our study is to compare basilar artery diameters (BAD) measured by T2WI to diameters measured by TOF MR angiography (MRA). By doing this, we hope to understand how compatible these two methodologies are with each other. We used data from 100 patients (59 females, 41 males) who underwent a session of both T2W MRI and TOF MRA at the same time (ages between 18 and 83). We measured BAD by both T2WI and TOF MRA in three different levels. We then compared these diameters measured by two different methodologies to each other. In an area between the vertebrobasilar junction and posterior cerebral artery, all data measured by T2WI and TOF MRA in three different levels were analyzed. Average diameters measured by T2WI and TOF MRA turned out to be 79.5% correlated with each other. As a result of our mathematical model that we came up with through regression analysis, we calculated that measurements taken by T2WI on mid-pontine levels could predict TOF MRA measures with 78.3% accuracy. In T2WI and TOF MRA, average diameters measured were 2.982 ± 0.4717 and 3.205 ± 0.4281 mm, respectively. Statistical analyses showed that images measured by T2W series were significantly smaller than those measured by TOF MRA (p < 0.05). Our study showed that BAD measured by T2WI were smaller than those measured by TOF MRA. We think that it will be beneficial to refer our results to avoid T2WI and TOF MRA mismatch when evaluating BAD.

  2. Does conduit artery diameter vary according to the anthropometric characteristics of children or men?

    Science.gov (United States)

    Hopkins, N D; Green, D J; Tinken, T M; Sutton, L; McWhannell, N; Thijssen, D H J; Cable, N T; Stratton, G; George, K

    2009-12-01

    Arterial measurements are commonly undertaken to assess acute and chronic adaptations to exercise. Despite the widespread adoption of scaling practices in cardiac research, the relevance of scaling for body size and/or composition has not been addressed for arterial measures. We therefore investigated the relationships between brachial artery diameter and body composition in 129 children aged 9 to 10 yr (75 girls and 54 boys), and 50 men aged 16-49 yr. Body composition variables (total, lean, and fat mass in the whole body, arm, and forearm) were assessed by dual-energy X-ray absorptiometry, and brachial artery diameter was measured using high-resolution ultrasound. Bivariate correlations were performed, and arterial diameter was then scaled using simple ratios (y/x) and allometric approaches after log-log least squares linear regression and production of allometric exponents (b) and construction of power function ratios (y/xb). Size independence was checked via bivariate correlations (x:y/x; x:y/xb). As a result, significant correlations existed between brachial artery diameter and measures of body mass and lean mass in both cohorts (r=0.21-0.48, P0.05). In conclusion, when between- or within-group comparisons are performed under circumstances where it is important to control for differences in body size or composition, allometric scaling of artery diameter should be adopted rather than ratio scaling. Our data also suggest that scaling for lean or total mass may be more appropriate than scaling for indexes of fat mass.

  3. Management of Benign Tracheal Stenosis by Small-diameter Tube-assisted Bronchoscopic Balloon Dilatation

    Directory of Open Access Journals (Sweden)

    Yi-Lin Liang

    2015-01-01

    Full Text Available Background: A limitation of bronchoscopic balloon dilatation (BBD is that airflow must be completely blocked for as long as possible during the operation. However, the patient often cannot hold his or her breath for a long period affecting the efficacy of the procedure. In this study, we used an extra-small-diameter tube to provide assisted ventilation to patients undergoing BBD and assessed the efficacy and safety of this technique. Methods: Bronchoscopic balloon dilatation was performed in 26 patients with benign tracheal stenosis using an extra-small-diameter tube. The tracheal diameter, dyspnea index, blood gas analysis results, and complications were evaluated before and after BBD. Statistical analyses were performed by SPSS version 16.0 for Windows (SPSS, Inc., Chicago, IL, USA. Results: Sixty-three BBD procedures were performed in 26 patients. Dyspnea immediately improved in all patients after BBD. The tracheal diameter significantly increased from 5.5 ± 1.5 mm to 13.0 ± 1.3 mm (P < 0.001, and the dyspnea index significantly decreased from 3.4 ± 0.8 to 0.5 ± 0.6 (P < 0.001. There was no significant change in the partial pressure of oxygen during the operation (before, 102.5 ± 27.5 mmHg; during, 96.9 ± 30.4 mmHg; and after, 97.2 ± 21.5 mmHg; P = 0.364, but there was slight temporary retention of carbon dioxide during the operation (before, 43.5 ± 4.2 mmHg; during, 49.4 ± 6.8 mmHg; and after, 40.1 ± 3.9 mmHg; P < 0.001. Conclusion: Small-diameter tube-assisted BBD is an effective and safe method for the management of benign tracheal stenosis.

  4. Measured Performance of a Varied Airflow Small-Diameter Duct System

    Energy Technology Data Exchange (ETDEWEB)

    Poerschke, Andrew [IBACOS, Inc., Pittsburgh, PA (United States)

    2017-03-16

    This study tests the performance of a variable airflow small-diameter duct heating, ventilation, and air conditioning (HVAC) system in a new construction unoccupied low-load test house in Pittsburgh, Pennsylvania. The duct system was installed entirely in conditioned space and was operated from the winter through summer seasons. Measurements were collected on the in-room temperatures and energy consumed by the air handler and heat pump unit. Operation modes with three different volumes of airflow were compared to determine the ideal airflow scenario that maximizes room-to-room thermal uniformity while minimizing fan energy consumption. Black felt infrared imagery was used as a measure of diffuser throw and in-room air mixing. Measured results indicate the small-diameter, high velocity airflow system can provide comfort under some conditions. Solar heat gains resulted in southern rooms drifting beyond acceptable temperature limits. Insufficient airflow to some bedrooms also resulted in periods of potential discomfort. Homebuilders or HVAC contractors can use these results to assess whether this space conditioning strategy is an attractive alternative to a traditional duct system. The team performed a cost analysis of two duct system configurations: (1) a conventional diameter and velocity duct system, and (2) the small-diameter duct system. This work applies to both new and retrofit homes that have achieved a low heating and cooling density either by energy conservation or by operation in a mild climate with few heating or cooling degree days. Guidance is provided on cost trade-offs between the conventional duct system and the small-diameter duct system.

  5. VizieR Online Data Catalog: JMMC Stellar Diameters Catalogue - JSDC. Version 2 (Bourges+, 2017)

    Science.gov (United States)

    Bourges, L.; Mella, G.; Lafrasse, S.; Duvert, G.; Chelli, A.; Le Bouquin, J.-B.; Delfosse, X.; Chesneau, O.

    2017-01-01

    The JMMC (Jean-Marie Mariotti Center) Calibrator Workgroup has long developed methods to estimate the angular diameter of stars, and provides this expertise in the SearchCal tool (http://www.jmmc.fr/searchcal). SearchCal creates a dynamical catalogue of stars suitable to calibrate Optical Long-Baseline Interferometry (OLBI) observations from on-line queries of CDS catalogues, according to observational parameters. In essence, SearchCal is limited only by the completeness of the stellar catalogues it uses, and in particular is not limited in magnitude. SearchCal being an application centered on the somewhat restricted OLBI observational purposes, it appeared useful to make our angular diameter estimates available for other purposes through a CDS-based catalog, the JMMC Stellar Diameters Catalogue (JSDC, II/300). This second version of the catalog represents a tenfold improvement both in terms of the number of objects and on the precision of the estimates. This is due to a new algorithm using reddening-free quantities -- the pseudomagnitudes, allied to a new database of all the measured stellar angular diameters -- the JMDC (II/345/jmdc), and a rigorous error propagation at all steps of the processing. All this is described in the associated publication by Chelli et al. (2016A&A...589A.112C). The catalog reports the Limb-Darkened Diameter (LDD) and error for 465877 stars, as well as their BVRIJHKLMN magnitudes, Uniform Disk Diameters (UDD) in these same photometric bands, Spectral Type, and two supplementary quality indicators: - the mean-diameter chi-square (see Appendix A.2 of Chelli et al., 2016A&A...589A.112C). - a flag indicating some degree of caution in choosing this star as an OLBI calibrator: known spectroscopic binaries, Algol type stars, etc, see Note (1). The conversion from LDD to UDD in each spectral band is made using mainly the coefficients from J/A+A/556/A86/table16 and J/A+A/554/A98/table16 when possible (compatible spectral types) and following the

  6. Height-Diameter Models for Mixed-Species Forests Consisting of Spruce, Fir, and Beech

    Directory of Open Access Journals (Sweden)

    Petráš Rudolf

    2014-06-01

    Full Text Available Height-diameter models define the general relationship between the tree height and diameter at each growth stage of the forest stand. This paper presents generalized height-diameter models for mixed-species forest stands consisting of Norway spruce (Picea abies Karst., Silver fir (Abies alba L., and European beech (Fagus sylvatica L. from Slovakia. The models were derived using two growth functions from the exponential family: the two-parameter Michailoff and three-parameter Korf functions. Generalized height-diameter functions must normally be constrained to pass through the mean stand diameter and height, and then the final growth model has only one or two parameters to be estimated. These “free” parameters are then expressed over the quadratic mean diameter, height and stand age and the final mathematical form of the model is obtained. The study material included 50 long-term experimental plots located in the Western Carpathians. The plots were established 40-50 years ago and have been repeatedly measured at 5 to 10-year intervals. The dataset includes 7,950 height measurements of spruce, 21,661 of fir and 5,794 of beech. As many as 9 regression models were derived for each species. Although the “goodness of fit” of all models showed that they were generally well suited for the data, the best results were obtained for silver fir. The coefficient of determination ranged from 0.946 to 0.948, RMSE (m was in the interval 1.94-1.97 and the bias (m was -0.031 to 0.063. Although slightly imprecise parameter estimation was established for spruce, the estimations of the regression parameters obtained for beech were quite less precise. The coefficient of determination for beech was 0.854-0.860, RMSE (m 2.67-2.72, and the bias (m ranged from -0.144 to -0.056. The majority of models using Korf’s formula produced slightly better estimations than Michailoff’s, and it proved immaterial which estimated parameter was fixed and which parameters

  7. Clinical analysis on the pupil diameter changes of cataract patients during phacoemulsification

    Directory of Open Access Journals (Sweden)

    Hua Guo

    2015-02-01

    Full Text Available AIM: To study the changes of pupil diameter and its effects during phacoemulsification.METHODS:Block design, prospective study. 60 cataract patients(60 eyeswere selected, which divided into two groups according to the age, young age group(group A, 20 eyes of 20 patientsand older age group(group B, 40 eyes of 40 patients. Two groups were all given compound tropicamide eye drops for fully mydriasis before operation, computer software to process images during operation, and according to the cornea amplification ratio measure pupil diameter during the operation phase: before the corneal tunnel incision(t1, after injection of sodium hyalurantae(t2, before artificial lens implantation(t3, at the end of the surgery(t4. Statistical analysis of data using SPSS18.0 software.RESULTS: The pupil diameter measurements of t1-t4 were followed respectively: group A were 8.36±0.65, 8.97±0.50, 8.67±0.63, 8.72±0.96mm; group B were 7.73±0.58, 8.23±0.59, 7.89±0.16, 7.70±0.63mm. Overall comparisons between the two groups, the pupil diameter measurements had differences during the operation phase(F=26.696,PPF=2.617,P>0.05. Comparisons in a group at different time points: the pupil diameter of t2 was larger than that in t1, with statistically differences(P>0.05, the pupil diameter of t3 and t4 were decreased in group B, with statistically differences(PCONCLUSION: Compound tropicamide eye drops are given for mydriasis before operation, young patients with cataract and senile patients with cataract can achieve the effect of surgery for mydriasis, the pupil stability of phacoemulsification in senile patients with cataract are lower than that in young patients with cataract.

  8. Role of KATP channels in the regulation of rat dura and pia artery diameter

    DEFF Research Database (Denmark)

    Gozalov, A.; Petersen, K.A.; Mortensen, C.

    2005-01-01

    The aim of the present study was to examine the effect of K(ATP) channel openers pinacidil and levcromakalim on rat dural and pial arteries as well as their inhibition by glibenclamide. We used an in-vivo genuine closed cranial window model and an in-vitro organ bath. Glibenclamide alone reduced...... the dural but not the pial artery diameter compared with controls. Intravenous pinacidil and levcromakalim induced dural and middle cerebral artery relaxation that was significantly attenuated by glibenclamide. In conclusion, K(ATP) channel openers induce increasing diameter/relaxation of dural and pial...... arteries after intravenous infusion in vivo and on isolated arteries in vitro. Furthermore, dural arteries were more sensitive to K(ATP) channel openers than pial arteries....

  9. The Effect Of Normocephalic Foetal Skull On Foetal Dating Using Biparietal Diameter

    Directory of Open Access Journals (Sweden)

    Ugwu AC

    2008-07-01

    Full Text Available The study was conducted to determine the desirability or otherwise of mathematically correcting every normal foetal head shape to an ideal shape prior to dating using the biparietal diameter (BPD. Transabdominal Sonography was performed in 118 pregnant women in their second- and third- trimesters. The BPDs and fronto-occipital diameters (FODs were measured. A study of 100 foetuses with normal head shapes was used to derive in this environment, a regression equation for an area corrected BPD (BPDa: BPDa = - 2. 853 + 0.483 (BPD + FOD. The BPDa of 18 foetuses with normal head shapes, were computed with this equation. Z test was performed to compare the mean BPD and Mean BPDa. Z statistic showed no significant difference (p>0.5 between BPDa and BPD in this group of foetuses with normal head shapes. There is no need to mathematically correct normocephalic foetal head shapes to ideal shapes before dating using the BPDs

  10. A Comparison among Solar Diameter Measurements Carried Out from the Ground and outside Earth's Atmosphere

    Science.gov (United States)

    Djafer, D.; Thuillier, G.; Sofia, S.

    2008-03-01

    The solar diameter has been measured since the 17th century, using different methods and instruments, and without a clear strategy of measurement, which could explain the lack of coherence between the results obtained. The present study confirms that the discrepancies between solar diameter measurements are mostly due to differences in instrumental characteristics, the spectral domain of observation of each investigation, and atmospheric turbulence for ground measurements. We show that correcting the measurements for the effects introduced by the properties of each instrument reduces the differences between the radius measurements to the level of uncertainty of each instrument. This study makes use of simulated and real data. For the simulated data, we use an empirical model of the solar limb shape, and for observations, we use measurements carried out with the Solar Disk Sextant experiment, the CCD solar astrolabe of Calern Observatory, and the Michelson Doppler Imager on board SOHO.

  11. Influence of electrospinning parameters on the structural morphology and diameter of electrospun nanofibers

    CSIR Research Space (South Africa)

    Jacobs, V

    2009-11-01

    Full Text Available & Sons, Inc. Journal of Applied Polymer Science For Peer Revie w TABLE I Diameter (nm) Mean % Change in diameter w.r.t 3% PEO Mean Sample Code Concentration of PEO (%) Min Max Min Max NF-P3 3 34.37 89.98 - - NF-P4 4 48.03 102.79 40 14... NF-P5 5 59.21 155.82 72 73 NF-P6 6 69.44 280.82 102 212 NF-P7 7 83.96 445.95 144 396 Page 15 of 24 John Wiley & Sons, Inc. Journal of Applied Polymer Science For Peer Revie w TABLE II Conductivity (mS/cm) Polyelectrolyte...

  12. Thermocapillary Flow and Coalescences of Heterogeneous Bubble Size Diameter in a Rotating Cylinder: 3D Study

    Science.gov (United States)

    Alhendal, Yousuf; Turan, Ali

    2016-12-01

    Two dimensional axisymmetric and three-dimensional VOF simulations of gas/liquid transient flow were performed using a multiphase flow algorithm based on the finite-volume method. The results for motion of a multiple bubbles of a heterogeneous sizes aligned horizontally and perpendicular to a hot surface incorporating thermocapillary forces in a rotating liquid in a zero-gravity environment have been presented for the first time. No bubbles broke in any of the cases observed. The results also show that collision and agglomeration of bubbles of unequal sizes diameter are different from those of similar size diameters presented from earlier research work of Alhendal et al. Acta Astronaut. 117, 484-496 (2015). Different flow patterns such as thermocapillary bubble migration, collision, and stream function were observed and presented for the 2-D and 3-D models.

  13. A Case Study of UAS Borne Laser Scanning for Measurement of Tree Stem Diameter

    Directory of Open Access Journals (Sweden)

    Martin Wieser

    2017-11-01

    Full Text Available Diameter at breast height (DBH is one of the most important parameter in forestry. With increasing use of terrestrial and airborne laser scanning in forestry, new exceeding possibilities to directly derive DBH emerge. In particular, high resolution point clouds from laser scanners on board unmanned aerial systems (UAS are becoming available over forest areas. In this case study, DBH estimation from a UAS point cloud based on modeling the relevant part of the tree stem with a cylinder, is analyzed with respect to accuracy and completeness. As reference, manually measured DBHs and DBHs from terrestrial laser scanning point clouds are used for comparison. We demonstrate that accuracy and completeness of the cylinder fit are depending on the stem diameter. Stems with DBH > 20 cm feature almost 100% successful reconstruction with relative differences to the reference DBH of 9% (DBH 20–30 cm down to 1.8% for DBH > 40 cm.

  14. Composition and diameter modulation of magnetic nanowire arrays fabricated by a novel approach

    Science.gov (United States)

    Shaker Salem, Mohamed; Tejo, Felipe; Zierold, Robert; Sergelius, Philip; Montero Moreno, Josep M.; Goerlitz, Detlef; Nielsch, Kornelius; Escrig, Juan

    2018-02-01

    Straight magnetic nanowires composed of nickel and permalloy segments having different diameters are synthesized using a promising approach. This approach involves the controlled electrodeposition of each magnetic material into specially designed diameter-modulated porous alumina templates. Standard alumina templates are exposed to pore widening followed by a protective coating of the pore wall with ultrathin silica and further anodization. Micromagnetic simulations are employed to investigate the process of magnetization reversal in the fabricated nanowires when the magnetic materials exchange their places in the thick and thin segments. It is found that the magnetization reversal occurs by the propagation of transverse domain wall (DW) when the thick segment is composed of permalloy. However, the reversal process proceeds by the propagation of vortex DW when permalloy is located at the thin segment.

  15. Dynamic Measurement for the Diameter of A Train Wheel Based on Structured-Light Vision

    Directory of Open Access Journals (Sweden)

    Zheng Gong

    2016-04-01

    Full Text Available Wheels are very important for the safety of a train. The diameter of the wheel is a significant parameter that needs regular inspection. Traditional methods only use the contact points of the wheel tread to fit the rolling round. However, the wheel tread is easily influenced by peeling or scraping. Meanwhile, the circle fitting algorithm is sensitive to noise when only three points are used. This paper proposes a dynamic measurement method based on structured-light vision. The axle of the wheelset and the tread are both employed. The center of the rolling round is determined by the axle rather than the tread only. Then, the diameter is calculated using the center and the contact points together. Simulations are performed to help design the layout of the sensors, and the influences of different noise sources are also analyzed. Static and field experiments are both performed, and the results show it to be quite stable and accurate.

  16. A flexible film type EMAT for inspection of small diameter pipe

    Energy Technology Data Exchange (ETDEWEB)

    Pei, Cuixiang; Xiao, Pan; Zhao, Siqi; Chen, Zhenmao [Xi' an Jiaotong University, Xi' an (China); Takagi, Toshiyuki [Institute of Fluid Science, Tohoku University, Sendai (Japan)

    2017-08-15

    Pipe structures are widely applied in industries, and different kinds of defects may occur in the structures during their long-time service. For non-destructive testing of defects in pipes of small diameter, it has to be conducted from the inner side of the pipe when there is no space for detection from the outside or the geometry of the outside tube surface is too complicated. In this work, a flexible film type Electromagnetic acoustic transducer (EMAT) probe with a dual coil configuration is developed. The new probe is flexible and can be inserted into the pipe for inspection. First, the feasibility of the new probe was studied through numerical simulation. Then the feasibility of the proposed flexible EMAT for detection of wall thinning in small diameter pipe was verified experimentally. It was found that the new EMAT method is suitable for the detection of wall thinning defects for small pipes.

  17. Study on the Matching of the Wind Turbine Capacity and the Rotor Diameter in Inner Mongolia

    Science.gov (United States)

    Cao, Liang; Wu, Yong Zhong

    2017-05-01

    There are abundant wind resources in Inner Mongolia Autonomous Region and in order to develop the wind resources economically and reasonably, it is necessary to produce and promote wind turbine generators that fit the exploitation of the wind resources. The energy generated by the wind turbines is closely linked to the rotor swept area. If the rotor diameter doubles, the wind power will increase by four times. This paper, based on the actual wind resources, divided Inner Mongolia into different regions, and, in accordance with the present wind farm development in Inner Mongolia and the on-grid energy requirements, offered a scheme for the matching of the unit capacity and the rotor diameter in wind farms of some typical regions, which provides some scientific and theoretical references for the proper selection of the wind turbine generator parameters.

  18. Measured cathode fall characteristics depending on the diameter of a hydrogen hollow cathode discharge

    Science.gov (United States)

    Gonzalez-Fernandez, V.; Grützmacher, K.; Steiger, A.; Pérez, C.; de la Rosa, M. I.

    2017-10-01

    In this work, Doppler-free two photon optogalvanic spectroscopy is used to measure the electric field strength in the cathode fall region of a hollow cathode discharge, operated in pure hydrogen, via the Stark splitting of the 2S level of atomic hydrogen. The cathode fall characteristics are analysed for various pressures and in a wide range of discharge currents. Tungsten is used as the cathode material, because it allows for reliable measurements in a fairly wide range of discharge conditions and because of its minimal sputtering. Two cathode diameters (10 mm and 15 mm) are used to study the dependence of the cathode fall on discharge geometry. The measurements reveal that the cathode fall characteristics are quite independent on the cathode diameter for equal cathode current density; hence the measurements can be used to test one dimensional modelling of the cathode fall region for low pressure hydrogen discharges using e.g. plane parallel electrodes.

  19. Unveiling the Evolutions of Nanotube Diameter Distribution during the Growth of Single-Walled Carbon Nanotubes.

    Science.gov (United States)

    Navas, Hugo; Picher, Matthieu; Andrieux-Ledier, Amandine; Fossard, Frédéric; Michel, Thierry; Kozawa, Akinari; Maruyama, Takahiro; Anglaret, Eric; Loiseau, Annick; Jourdain, Vincent

    2017-03-28

    In situ and ex situ Raman measurements were used to study the dynamics of the populations of single-walled carbon nanotubes (SWCNTs) during their catalytic growth by chemical vapor deposition. Our study reveals that the nanotube diameter distribution strongly evolves during SWCNT growth but in dissimilar ways depending on the growth conditions. We notably show that high selectivity can be obtained using short or moderate growth times. High-resolution transmission electron microscopy observations support that Ostwald ripening is the key process driving these seemingly contradictory results by regulating the size distribution and lifetime of the active catalyst particles. Ostwald ripening appears as the main termination mechanism for the smallest diameter tubes, whereas carbon poisoning dominates for the largest ones. By unveiling the key concept of dynamic competition between nanotube growth and catalyst ripening, we show that time can be used as an active parameter to control the growth selectivity of carbon nanotubes and other 1D systems.

  20. Near- and supercritical water as a diameter manipulation and surface roughening agent in fused silica capillaries.

    Science.gov (United States)

    Karásek, Pavel; Planeta, Josef; Roth, Michal

    2013-01-02

    The prospects of near- and supercritical water for treatment of the inner surfaces of fused silica capillaries have been tested employing an in-lab-assembled apparatus. Unlike all other agents used for the purpose, water cannot introduce any undesirable heteroatoms to the treated surface. Theoretical background for this work comes from the well-known fact that water near its critical point can solubilize silica. The results show that depending on the temperature, water flow rate, flow mode, and exposure time, high-temperature water has wide-ranging effects on both the surface roughness and the internal diameter profile along the length of the treated capillary. By judicious selection of the operating conditions, tapered capillaries of various profiles for applications in electromigration techniques can be prepared with relatively high reproducibility. The water-treated fused silica capillaries with uniform internal diameter appear to be useful for preparation of monolithic silica capillary columns.

  1. A step toward production of smaller diameter single wall carbon nanotubes

    Directory of Open Access Journals (Sweden)

    V. Lemos

    2003-01-01

    Full Text Available Single-wall carbon nanotubes were produced with, either, a bimetallic or a mixture of three catalysts. Raman scattering and high resolution transmission electron microscopy were used as characterization tools. The mixture LiNi0.5Co0.5O2 leaded to a sample relatively free from impurities with long bundles, each containing a few tubes. A narrow distribution of diameters for the sample produced with this mixture was evidenced by Raman scattering experiences. The mean tube diameter was found to be smaller than those measured for the nanotubes obtained with the bimetallic catalysts, Fe/Ni and Ni/Co. Possible chiralities were calculated for the semiconductor nanotubes formed. Assignments of the Raman radial breathing mode frequencies to the calculated structures are presented.

  2. Optical coherence tomography and vessel diameter changes after intravitreal bevacizumab in diabetic macular oedema

    DEFF Research Database (Denmark)

    Soliman, W.; Vinten, M.; Sander, B.

    2008-01-01

    acuity (BCVA) in Early Treatment Diabetic Retinopathy Study letters, macular volume, foveal subfield thickness and vessel diameter measurement. Results: Intravitreal administration of bevacizumab was followed by a mean increase in BCVA of 7.3 +/- 17 (mean +/- standard deviation) letters between baseline......Purpose: To assess the effect of intravitreal bevacizumab on diabetic macular oedema (DMO) and retinal vessel calibres. Methods: We performed a consecutive case series study in which 10 consecutive eyes with diffuse DMO, two of which had not previously been treated, received an intravitreal...... diabetic retinopathy lost all signs of proliferation without any evidence of fibrosis. Although there was a trend towards vasoconstriction, the changes in vessel diameters (arteries and veins) after 4 months of intravitreal Avastin injection were not statistically significant (p = 0.9 and p = 0...

  3. What's in a Pipe?: NATO's Confrontation on the 1962 Large-Diameter Pipe Embargo.

    Science.gov (United States)

    Cantoni, Roberto

    By the late 1950s, the Soviet Union had acquired a strong position as a world oil exporter, thanks to major discoveries in the Ural-Volga area. In order to transport their oil to strategic areas within the Union and to Europe, the Soviets devised a project to build a colossal pipeline system. This plan caused anxiety at NATO since Russian oil could be wielded as a weapon to weaken the West both militarily and economically. In order to complete the system, however, the Soviets needed large-diameter steel pipes and equipment, which they had to import from the West. Thus in 1961 the U.S. delegation at NATO proposed a comprehensive embargo of large-diameter pipes in order to delay the system's construction. I argue that the definition of what oil pipes were as technological artifacts, as well as their final content, was ultimately shaped by the NATO debate on this U.S. proposition.

  4. Application Study of Self-balanced Testing Method on Big Diameter Rock-socketed Piles

    Directory of Open Access Journals (Sweden)

    Qing-biao WANG

    2013-07-01

    Full Text Available Through the technological test of self-balanced testing method on big diameter rock-socketed piles of broadcasting centre building of Tai’an, this paper studies and analyzes the links of the balance position selection, the load cell production and installation, displacement sensor selection and installation, loading steps, stability conditions and determination of the bearing capacity in the process of self-balanced testing. And this paper summarizes key technology and engineering experience of self-balanced testing method of big diameter rock-socketed piles and, meanwhile, it also analyzes the difficult technical problems needed to be resolved urgently at present. Conclusion of the study has important significance to the popularization and application of self-balanced testing method and the similar projects.

  5. Cardiac Events and the Maximum Diameter of Coronary Artery Aneurysms in Kawasaki Disease.

    Science.gov (United States)

    Tsuda, Etsuko; Tsujii, Nobuyuki; Hayama, Yosuke

    2017-09-01

    To clarify the occurrence of cardiac events based on the maximal diameter of the maximal coronary artery aneurysm (CAA) in Kawasaki disease (KD). Two hundred fourteen patients (160 male and 54 female) who had had at least 1 CAA in the selective coronary angiogram less than 100 days after the onset of KD were studied. We measured the maximal CAA diameters in the major branches of the initial coronary angiograms. Death, myocardial infarction and coronary artery revascularization were included as cardiac events in this study. We divided the patients into three groups based on the maximal CAA diameter (large ≥8.0 mm; medium ≥6.0 mm and events based on laterality of maximal CAA (bilateral, unilateral) and body surface area (BSA). Cardiac events occurred in 44 patients (21%). For BSA event-free survival in the large and medium groups was 66% (n = 38, 95% CI, 49-80) and 62% (n = 27, 95% CI, 38-81), respectively. For BSA ≥ 0.50 m2, that in large group was 54% (n = 58, 95% CI, 40-67). There were no cardiac events in the medium group for BSA ≥0.50 m2 (n = 36) and the small group (n = 56). In the large analyzed group, the 30-year cardiac event-free survival in the bilateral and unilateral groups was 40% (n = 48, 95% CI, 27-55) and 78% (n = 48, 95% CI, 63-89), respectively (P events was the patient group with the maximal CAA diameter ≥6.0 mm with BSA event-free survival was about 60%. Given the high rate of cardiac events in this patient population, life-long cardiovascular surveillance is advised. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Firing of antagonist small-diameter muscle afferents reduces voluntary activation and torque of elbow flexors.

    Science.gov (United States)

    Kennedy, David S; McNeil, Chris J; Gandevia, Simon C; Taylor, Janet L

    2013-07-15

    During muscle fatigue, firing of small-diameter muscle afferents can decrease voluntary activation of the fatigued muscle. However, these afferents may have a more widespread effect on other muscles in the exercising limb. We examined if the firing of fatigue-sensitive afferents from elbow extensor muscles in the same arm reduces torque production and voluntary activation of elbow flexors. In nine subjects we examined voluntary activation of elbow flexors by measuring changes in superimposed twitches evoked by transcranial magnetic stimulation of the motor cortex during brief (2-3 s) maximal voluntary contractions (MVC). Inflation of a blood pressure cuff following a 2-min sustained MVC blocked blood flow to the fatigued muscle and maintained firing of small-diameter afferents. After a fatiguing elbow flexion contraction, maximal flexion torque was lower (26.0 ± 4.4% versus 67.9 ± 5.2% of initial maximal torque; means ± s.d.; P torque was also reduced (82.2 ± 4.9% versus 91.4 ± 2.3% of initial maximal torque; P = 0.007), superimposed twitches were larger (2.7 ± 0.7% versus 1.3 ± 0.2% ongoing MVC; P = 0.02) and voluntary activation lower (81.6 ± 8.2% versus 95.5 ± 6.9%; P = 0.04) with than without ischaemia. After a fatiguing contraction, voluntary drive to the fatigued muscles is reduced with continued input from small-diameter muscle afferents. Furthermore, fatigue of the elbow extensor muscles decreases voluntary drive to unfatigued elbow flexors of the same arm. Therefore, firing of small-diameter muscle afferents from one muscle can affect voluntary activation and hence torque generation of another muscle in the same limb.

  7. Comparative study of tubular diameter and quantity for human and bovine dentin at different depths

    OpenAIRE

    Lopes,Murilo Baena; Sinhoreti,Mário A. C.; Gonini Júnior,Alcides; Consani,Simonides; Mccabe,John F.

    2009-01-01

    This study compared the tubular dimensions and distribution of human and bovine dentin. Ten human molars and 10 bovine incisors were ground with a high-speed handpiece to obtain 3 sections at different dentin depths (superficial, middle and deep). The specimens were sputter-coated with gold to be examined under scanning electron microscopy (SEM). Three SEM micrographs were recorded randomly for each dentin depth. The number of tubules was counted and the diameter of 5 tubules selected at rand...

  8. Fitting diameter distribution models to data from forest inventories with concentric plot design

    Energy Technology Data Exchange (ETDEWEB)

    Nanos, N.; Sjöstedt de Luna, S.

    2017-11-01

    Aim: Several national forest inventories use a complex plot design based on multiple concentric subplots where smaller diameter trees are inventoried when lying in the smaller-radius subplots and ignored otherwise. Data from these plots are truncated with threshold (truncation) diameters varying according to the distance from the plot centre. In this paper we designed a maximum likelihood method to fit the Weibull diameter distribution to data from concentric plots. Material and methods: Our method (M1) was based on multiple truncated probability density functions to build the likelihood. In addition, we used an alternative method (M2) presented recently. We used methods M1 and M2 as well as two other reference methods to estimate the Weibull parameters in 40000 simulated plots. The spatial tree pattern of the simulated plots was generated using four models of spatial point patterns. Two error indices were used to assess the relative performance of M1 and M2 in estimating relevant stand-level variables. In addition, we estimated the Quadratic Mean plot Diameter (QMD) using Expansion Factors (EFs). Main results: Methods M1 and M2 produced comparable estimation errors in random and cluster tree spatial patterns. Method M2 produced biased parameter estimates in plots with inhomogeneous Poisson patterns. Estimation of QMD using EFs produced biased results in plots within inhomogeneous intensity Poisson patterns. Research highlights:We designed a new method to fit the Weibull distribution to forest inventory data from concentric plots that achieves high accuracy and precision in parameter estimates regardless of the within-plot spatial tree pattern.

  9. Influence of Thread Root Radius on Maximum Local Stresses at Large Diameter Bolts under Axial Loading

    Directory of Open Access Journals (Sweden)

    Cojocaru Vasile

    2014-06-01

    Full Text Available In the thread root area of the threaded bolts submitted to axial loading occur local stresses, higher that nominal stresses calculated for the bolts. These local stresses can generate failure and can reduce the fatigue life of the parts. The paper is focused on the study of the influence of the thread root radius on the maximum local stresses. A large diameter trapezoidal bolt was subjected to a static analysis (axial loading using finite element simulation.

  10. Lumbar spinal canal MRI diameter is smaller in herniated disc cauda equina syndrome patients

    OpenAIRE

    Korse, Nina S.; Kruit, Mark C.; Peul, Wilco C.; Vleggeert-Lankamp, Carmen L. A.

    2017-01-01

    Introduction Correlation between magnetic resonance imaging (MRI) and clinical features in cauda equina syndrome (CES) is unknown; nor is known whether there are differences in MRI spinal canal size between lumbar herniated disc patients with CES versus lumbar herniated discs patients without CES, operated for sciatica. The aims of this study are 1) evaluating the association of MRI features with clinical presentation and outcome of CES and 2) comparing lumbar spinal canal diameters of lumbar...

  11. Re-introduction of transmembrane serine residues reduce the minimum pore diameter of channelrhodopsin-2.

    Directory of Open Access Journals (Sweden)

    Ryan Richards

    Full Text Available Channelrhodopsin-2 (ChR2 is a microbial-type rhodopsin found in the green algae Chlamydomonas reinhardtii. Under physiological conditions, ChR2 is an inwardly rectifying cation channel that permeates a wide range of mono- and divalent cations. Although this protein shares a high sequence homology with other microbial-type rhodopsins, which are ion pumps, ChR2 is an ion channel. A sequence alignment of ChR2 with bacteriorhodopsin, a proton pump, reveals that ChR2 lacks specific motifs and residues, such as serine and threonine, known to contribute to non-covalent interactions within transmembrane domains. We hypothesized that reintroduction of the eight transmembrane serine residues present in bacteriorhodopsin, but not in ChR2, will restrict the conformational flexibility and reduce the pore diameter of ChR2. In this work, eight single serine mutations were created at homologous positions in ChR2. Additionally, an endogenous transmembrane serine was replaced with alanine. We measured kinetics, changes in reversal potential, and permeability ratios in different alkali metal solutions using two-electrode voltage clamp. Applying excluded volume theory, we calculated the minimum pore diameter of ChR2 constructs. An analysis of the results from our experiments show that reintroducing serine residues into the transmembrane domain of ChR2 can restrict the minimum pore diameter through inter- and intrahelical hydrogen bonds while the removal of a transmembrane serine results in a larger pore diameter. Therefore, multiple positions along the intracellular side of the transmembrane domains contribute to the cation permeability of ChR2.

  12. Colour of the nucleus as a marker of nuclear hardness, diameter and central thickness

    Directory of Open Access Journals (Sweden)

    Gullapalli Vamsi

    1995-01-01

    Full Text Available Hundred and thirty patients, aged above 40 years, with senile cataract were examined. Age and colour were selected as the probable preoperative indicators of nuclear hardness. The lens material collected after manual extracapsular extraction was washed and the nucleus isolated. The diameter and central thickness of the nucleus were measured; the mean diameter and mean central thickness were 7.13 mm ± 0.76 and 3.05 mm ± 0.48, respectively. The hardness of the nucleus was measured with a lens guillotine designed by us. Regression analysis was applied to the parameters measured and these were compared with the colour and age. The parameters measured had the following relationship: Colour vs hardness (r value = 0.7569 (p < 0.001 Colour vs diameter (r value = 0.3962 (p < 0.001 Colour vs central thickness (r value = 0.4785 (p < 0.001 Age vs hardness (r value = -0.0499 (p > 0.05 Age vs diameter (r value = 0.0987 (p > 0.05 Age vs central thickness (r value = 0.1700 (p > 0.05 The values showed that colour had a statistically significant relationship with all the 3 parameters (p < 0.001, while age had no significant relationship with the same parameters. The results indicated that colour can be used more reliably to predict physical characteristics of the cataractous lens nucleus, the preoperative knowledge of which would help the surgeon in planning small-incision surgery including phacoemulsification.

  13. Low Noise Signal Processing Technique for Monopulse Pointing of DSN 34-meter Diameter Antennas

    Science.gov (United States)

    Gudim, M.; Gawronski, W.

    2000-01-01

    This paper describes a 31.8 - 32.3 GHz (Ka-band) monopulse antenna pointing system designed to meet a pointing precision requirement of a mean-radial-error (MRE) less than 1.5 milli-degrees for a 34-meter diameter antenna with a 17 milli-degree 3-dB beam-width, under windy conditions up to 15mph.

  14. Effect of logging wounds on diameter growth of sawlog-size Appalachian hardwood crop trees

    Science.gov (United States)

    Neil I. Lamson; H. Clay Smith; H. Clay Smith

    1988-01-01

    In previously thinned, even-aged Appalachian hardwood stands, 5-year diameter growth of 102 wounded and 102 unwounded codominant crop trees were compared. A wounded crop tre was defined as one with at least one exposed sapwood logging wound at least 100 inch2 in size. An unwounded crop tree of the same species and size was selected near each of the 102 wounded trees....

  15. A study of water pressure influence on failure of large diameter water pipelines

    OpenAIRE

    Rathnayaka, Suranji Uditha Priyankara

    2017-01-01

    This research is part of a large research project investigating how, when, and where critical pipes (diameter≥300mm) fail in water supply networks. The failure of large- diameter pipe is critical, as it may have devastating consequences for both the public and the water utility. Factors contributing to pipe failure, such as internal pressure, external load, and corrosion, are examined in this research. The objective of the study is to understand the contribution of internal water pressur...

  16. Type III collagen can be present on banded collagen fibrils regardless of fibril diameter

    OpenAIRE

    1987-01-01

    Monoclonal antibodies that recognize an epitope within the triple helix of type III collagen have been used to examine the distribution of that collagen type in human skin, cornea, amnion, aorta, and tendon. Ultrastructural examination of those tissues indicates antibody binding to collagen fibrils in skin, amnion, aorta, and tendon regardless of the diameter of the fibril. The antibody distribution is unchanged with donor age, site of biopsy, or region of tissue examined. In contrast, antibo...

  17. Grid-translation beam deflection systems for 5-cm and 30-cm diameter Kaufman thrusters

    Science.gov (United States)

    Lathem, W. C.

    1972-01-01

    A 5-cm grid translation mechanism has been developed capable of 10 deg beam deflection. A 2026-hour endurance test was run at a preset 10 deg deflection angle and an extrapolated lifetime of better than 10,000 hours obtained. Response time data for grid translation are presented. Preliminary results for a 30-cm diameter system are given and results of a theoretical analysis of a dished grid system are discussed.

  18. Diameter-growth model across shortleaf pine range using regression tree analysis

    Science.gov (United States)

    Daniel Yaussy; Louis Iverson; Anantha Prasad

    1999-01-01

    Diameter growth of a tree in most gap-phase models is limited by light, nutrients, moisture, and temperature. Growing-season temperature is represented by growing degree days (gdd), which is the sum of the average daily temperatures above a baseline temperature. Gap-phase models determine the north-south range of a species by the gdd limits at the north and south...

  19. The use of large-diameter boreholes for the rescue of trapped miners

    Energy Technology Data Exchange (ETDEWEB)

    Mangenot, G.

    1980-03-01

    This paper presents an account of research work undertaken by the French coal industry to examine ways of rescuing miners who are trapped underground. The three areas of research are: determining the exact location of the trapped men; drilling a hole for initial contact; sinking a large- diameter borehole through which the men can make their escape. The validity of the proposed solutions is determined by simulated tests. (In French)

  20. Performance evaluation of nebulizers based on aerodynamic droplet diameter characterization using the Direct Laminar Incidence (DLI

    Directory of Open Access Journals (Sweden)

    Luciana Martins Pereira de Araújo

    2017-06-01

    Full Text Available Abstract Introduction Optical microscope images can be useful to evaluate nebulizers considering the size of droplets produced by these devices. From this perspective, the proposed method was compared to the classic concept of Mass Median Aerodynamic Diameter (MMAD for the ideal droplet size between 0.5-5.5 µm. Methods We tested a sample of five home nebulizers sold on the Brazilian market. A high-speed camera coupled to a microscope obtained images of the droplets during the nebulization process, which allowed us to characterize the diameter of the aero-dispersed droplets. The Count Median Aerodynamic Diameter (CMAD was used as measurement parameter. Results The images obtained during the nebulization process with the five different nebulizers provided data to determine the frequency distribution of the aero-dispersed droplet population. Successive images were obtained in the range of 2.0s to evaluate the dynamic behavior of the droplets. The generated data also allowed the elaboration of histograms emphasizing the ideal diameter range of droplets between 0.5 and 5.5 μm. Conclusion The Direct Laminar Incidence (DLI model using digital image processing technique allowed the characterization of respirable particles. This model proposes the creation of a range of optimum absorption of the droplets by the respiratory tract. Although there is a technical limitation in the direct acquisition of images due to the depth of focus, presenting an error of 9.3%, the described method provides consistent results when compared to other droplets characterization techniques. Thus, the authors believe that Direct Laminar Incidence (DLI is a viable method to assess the performance of nebulizers despite the requirement of adjustments and possible improvements required to minimize measurement errors.

  1. Catheter dwell time and diameter affect the recurrence rates after internal urethrotomy.

    Science.gov (United States)

    Yürük, Emrah; Yentur, Serhat; Çakır, Ömer Onur; Ertaş, Kasım; Şerefoğlu, Ege Can; Semerciöz, Atilla

    2016-09-01

    Cold-knife direct vision internal urethrotomy (DVIU) is frequently used as the first-line treatment for urethral stricture disease. Although the steps of the procedure are defined in detail, the duration of catheterization and the diameter of the catheter to be used after the operation are not clearly defined. The aim of this study is to evaluate the effects of catheter dwell time and diameter on recurrence rates of urethral stricture disease after DVIU. Data of 193 consecutive treatment naïve bulbar urethral stricture patients who underwent DVIU between January 2009 and June 2013 were retrospectively analyzed. Patient demographics and stricture characteristics were noted. Catheter dwell times were grouped as dwell times, and diameter were evaluated with Tukey's test and Pearson's correlation test, respectively. Overall 193 patients with a mean age of 64.51±12.99 (range: 17 to 85) years were enrolled in the study. Urethral stricture disease recurred in 45 (23.31%) patients within the first year after DVIU. Mean duration of catheterization was 7.47±4.03 and 4.79±1.94 days in patients with and without recurrences, respectively (p=0.0001). Catheter dwell times for ≥5 days were also associated with increased recurrence (p=0.0001). Of the patients with recurrent strictures, 16, 18 and 22Fr catheters were placed in 22.22%, 20% and 57.78% of the patients, respectively. Increased catheter diameter was also associated with higher recurrence rates (p=0.004). Shortening the postoperative duration of catheterization and decreasing the catheter size may result in improved recurrence rates after DVIU. Further prospective randomized trials are necessary to confirm these findings.

  2. [Bone-tendon integration of autologous grafts using different diameter tunnels. An experimental study on sheep].

    Science.gov (United States)

    Sánchez Hidalgo, R; Forriol, F

    2012-01-01

    To analyse the bone-ligament integration «ligamentization» of the tendon graft in the reconstruction of anterior cruciate ligament (ACL) performing tunnels of different diameter. We performed the same reconstruction procedure using an autologous tendon graft taken from the superficial tendon of the hoof in 41 adult sheep. In Group A the tibial and femoral tunnels were 5 mm in diameter and in Group B they were 7 mm in diameter. The sheep were sacrificed at 3, 6 and 12 months after the surgery. Histological studies were performed on the graft and the tunnels, as well as a biomechanical analysis of the tibial-femoral complex. In group A we did not observe direct integration of the bone and the tendon graft or any fibres joining both structures, although there was vascularized fibrous tissue. In group B we did not observe any direct binding of the bone and the tendon graft either, although there was abundant fibrous tissue. The tendon graft showed a fascicular structure that increased over time in order to create septa for vascular penetration. Macroscopically the ACL graft had a dense appearance, which was very similar to the original tendon graft. The tendon grafts from group B and with a longer follow up period required a higher strength to produce maximum breakage than the tendon grafts from group A. After one year follow up, the histological study shows that the tendon graft is not transformed into a ligament, and there is no integration of the tendon graft in tunnels regardless of their diameter. Therefore, fixation techniques are essential to maintain the orientation and tension of the tendon graft. Copyright © 2011 SECOT. Published by Elsevier Espana. All rights reserved.

  3. Fique Fiber Tensile Elastic Modulus Dependence with Diameter Using the Weibull Statistical Analysis

    OpenAIRE

    Teles,Maria Carolina Andrade; Altoé,Giulio Rodrigues; Amoy Netto,Pedro; Colorado,Henry; Margem,Frederico Muylaert; Monteiro,Sergio Neves

    2015-01-01

    Fique is a plant native of Colombia with fibers extracted from its leaves presenting relevant physical characteristics and mechanical properties for possible engineering applications, such as reinforcement of polymer composites. The main physico-mechanical properties of the fique fiber have already been investigated for both untreated and mechanically treated fibers. The statistical distribution of the fique fiber diameter was analyzed and the effect of microfibrillar angle on the tensile str...

  4. The Palm-Heart Diameter: A Prospective Simple Screening Tool for Identifying Heart Enlargement

    OpenAIRE

    Adegbenro Omotuyi John Fakoya; David Adeiza Otohinoyi; Terrence Marcelle; Joshua Yusuf

    2017-01-01

    BACKGROUND: Several speculations have linked the size of the fist to be equal to the size of the heart. However, the substantial scientific report still lacks to support this theory. AIM: This study aims to provide the validity of the fist-heart assumption by correlating the palm and heart diameters while benchmarking it as a reference tool for determining the normal heart size. MATERIALS AND METHOD: Volunteers from the public were recruited during a health fair organised by the schoo...

  5. The influence of the equivalent hydraulic diameter on the pressure drop prediction of annular test section

    Science.gov (United States)

    Al-Kayiem, A. H. H.; Ibrahim, M. A.

    2015-12-01

    The flow behaviour and the pressure drop throughout an annular flow test section was investigated in order to evaluate and justify the reliability of experimental flow loop for wax deposition studies. The specific objective of the present paper is to assess and highlight the influence of the equivalent diameter method on the analysis of the hydrodynamic behaviour of the flow and the pressure drop throughout the annular test section. The test section has annular shape of 3 m length with three flow passages, namely; outer thermal control jacket, oil annular flow and inner pipe flow of a coolant. The oil annular flow has internal and external diameters of 0.0422 m and 0.0801 m, respectively. Oil was re-circulated in the annular passage while a cold water-glycol mixture was re-circulated in the inner pipe counter currently to the oil flow. The experiments were carried out at oil Reynolds number range of 2000 to 17000, covering laminar, transition and turbulent flow regimes. Four different methods of equivalent diameter of the annulus have been considered in this hydraulic analysis. The correction factor model for frictional pressure drop was also considered in the investigations. All methods addressed the high deviation of the prediction from the experimental data, which justified the need of a suitable pressure prediction correlation for the annular test section. The conventional hydraulic diameter method is a convenient substitute for characterizing physical dimension of a non-circular duct, and it leads to fairly good correlation between turbulent fluid flow and heat transfer characteristic of annular ducts.

  6. Assymetry of temporal artery diameters during spontaneous attacks of cluster headache

    DEFF Research Database (Denmark)

    Nielsen, Thue H; Tfelt-Hansen, Peer; Iversen, Helle K

    2009-01-01

    BACKGROUND: Cluster headache is characterized by strictly unilateral head pain associated with symptoms of cranial autonomic features. Transcranial Doppler studies showed in most studies a bilateral decreased blood flow velocity in the middle cerebral artery. OBJECTIVE: To investigate whether the...... = .67). CONCLUSIONS: What was observed is most likely a general pain-induced arterial vasoconstriction (confer the decrease in diameter on the pain-free side) with an unchanged superficial temporal artery on the pain side because of some vasodilator influence....

  7. Pupil Diameter Does Not Correlate with Fixation Duration - or Does It?

    DEFF Research Database (Denmark)

    Lykke Jakobsen, Arnt; Carl, Michael; Elming, Jakob

    2013-01-01

    A number of pupillometric studies have suggested that dynamic differences in pupil diameter correlate with dierent levels of cognitive intensity or excitement. Other studies have suggested a similar correlation between fixation duration and cognitive effort. Since both methodologies for hypothesi...... of what linguistic material they are fixations of. We tested the assumption on six recordings of translation sessions in three different experiments, all of which are available in the CBS database of translation and postediting process recordings....

  8. Modeling Caribbean tree stem diameters from tree height and crown width measurements

    Science.gov (United States)

    Thomas Brandeis; KaDonna Randolph; Mike Strub

    2009-01-01

    Regression models to predict diameter at breast height (DBH) as a function of tree height and maximum crown radius were developed for Caribbean forests based on data collected by the U.S. Forest Service in the Commonwealth of Puerto Rico and Territory of the U.S. Virgin Islands. The model predicting DBH from tree height fit reasonably well (R2 = 0.7110), with...

  9. Regime Analysis of Critical Raindrop Diameters for Rainfall Attenuation in Southern Africa

    OpenAIRE

    Adetan, O; Obiyemi, OO

    2016-01-01

    The influence of critical raindrop diameters on the specific rainfall attenuation in Durban (29o52'S, 30o58'E), South Africa using various rainfall regimes is analyzed in this paper. Different rain rate values representing drizzle, widespread, shower and thunderstorm are selected for the purpose of analysis over the measured raindrop size distribution. The three-parameter lognormal and gamma DSD models with shape parameter of 2 are used to estimate the parameters required to investigate the d...

  10. Ultrasonic micro-motor using miniature piezoelectric tube with diameter of 1.0 mm.

    Science.gov (United States)

    Zhang, Hui; Dong, Shu-xiang; Zhang, Shu-yi; Wang, Tian-hua; Zhang, Zhong-ning; Fan, Li

    2006-12-22

    At the present moment, the smallest piezoelectric ultrasonic micro-motors utilizing miniature PZT piezoelectric ceramic tubes were developed. The motor consists of a PZT-metal composite tube stator, two steel rotors and a thin shaft that keeps the two rotors pressing on both ends of the stator elastically. The dimensions of the PZT tube are 1.0 mm in outer diameter, 0.6 mm in inner diameter and 5.0 mm in length. The diameter and total length of the assembled micro-motor is 1.0 mm and 8 mm (including an adjusting spring), respectively. The tube-type micro-motor is driven by two pairs of alternative voltages with phase shift 90 degrees between the adjacent electrodes and operated in the first circular-bending vibration mode of the stator with the resonance frequency about 58 kHz. The experimental results show that the tube-type micro-motors have perfect performances: (i) high rotation frequency over 3000 rpm and (ii) large starting torque over 7.8 microN m under the conditions of the input voltage of 110 V(p-p) and the resonance frequency. The micro-motor is well suitable for operating in micro-spaces, such as in intravascular, micro-robots and micro-craft applications.

  11. A suspended core nanofiber with unprecedented large diameter ratio of holey region to core.

    Science.gov (United States)

    Liao, Meisong; Chaudhari, Chitrarekha; Yan, Xin; Qin, Guanshi; Kito, Chihiro; Suzuki, Takenobu; Ohishi, Yasutake

    2010-04-26

    For a suspended core nanofiber, the holey region is expected to be as large as possible to propagate the light at wavelengths as long as possible. Additionally, a large holey region is significant for its applications in sensors. However, the fabrication of nanofiber with large holey region is still a challenge so far. In this paper a method, which involves pumping positive pressure of nitrogen gas in both the cane fabrication and fiber-drawing processes, was proposed. A suspended core nanofiber, with a core diameter of around 480 nm and an unprecedented diameter ratio of holey region to core (DRHC) of at least 62, was fabricated in the length of several hundred meters. Owing to the large holey region, the confinement loss of the suspended core nanofiber is insignificant when the wavelength of light propagated in it is 1700 nm. For this fabrication technique, the nanowire length, fabrication efficiency, and the uniformity in the diameter are much superior to those of the nanowires fabricated in other ways. Finally, single mode third harmonic generation was observed by this nanofiber under the pump of a 1557 nm femtosecond fiber laser. This work shows the prospect of fabrication of nanostructured waveguide in glass materials by an inflation technique.

  12. Measures of Solar Diameter with Eclipses: Data Analysis, Problems and Perspectives

    Science.gov (United States)

    Sigismondi, Costantino

    2008-10-01

    The theme of solar diameter variability is presented with the data of solar astrolabes, the four data points of the Solar Disk Sextant and the central eclipses observed near the shadow's limbs. All data are from the last 3 decades. The results obtained with solar astrolabes are different from Northern (Calern) and Southern hemisphere (Rio de Janeiro, Santiago), this is possibly due to atmospheric effect. Eclipses measurements are not affected by atmospheric turbulence because the event's geometry is determined outside the atmosphere, they give systematically larger diameter values than astrolabes. Videos of eclipses are discussed in term of projection on a screen versus direct imaging at the focal plane with filtered telescope. Relations between filters densities, telescope diameters, frame rate of video cameras, and portion of the outer solar limb lost during eclipse imaging are presented. Loss of 0.02'' are typical for 10 cm ND5 filtered telescope. A commercial 60 fps camcorder for Baily beads timing is discussed in terms of signal-to-noise ratio.

  13. Non-destructive estimation of root pressure using sap flow, stem diameter measurements and mechanistic modelling.

    Science.gov (United States)

    De Swaef, Tom; Hanssens, Jochen; Cornelis, Annelies; Steppe, Kathy

    2013-02-01

    Upward water movement in plants via the xylem is generally attributed to the cohesion-tension theory, as a response to transpiration. Under certain environmental conditions, root pressure can also contribute to upward xylem water flow. Although the occurrence of root pressure is widely recognized, ambiguity exists about the exact mechanism behind root pressure, the main influencing factors and the consequences of root pressure. In horticultural crops, such as tomato (Solanum lycopersicum), root pressure is thought to cause cells to burst, and to have an important impact on the marketable yield. Despite the challenges of root pressure research, progress in this area is limited, probably because of difficulties with direct measurement of root pressure, prompting the need for indirect and non-destructive measurement techniques. A new approach to allow non-destructive and non-invasive estimation of root pressure is presented, using continuous measurements of sap flow and stem diameter variation in tomato combined with a mechanistic flow and storage model, based on cohesion-tension principles. Transpiration-driven sap flow rates are typically inversely related to stem diameter changes; however, this inverse relationship was no longer valid under conditions of low transpiration. This decoupling between sap flow rates and stem diameter variations was mathematically related to root pressure. Root pressure can be estimated in a non-destructive, repeatable manner, using only external plant sensors and a mechanistic model.

  14. The effect of the impactor diameter and temperature on low velocity impact behavior of CFRP laminates

    Science.gov (United States)

    Evci, C.; Uyandıran, I.

    2017-02-01

    Impact damage is one of the major concerns that should be taken into account with the new aircraft and spacecraft structures which employ ever-growing use of composite materials. Considering the thermal loads encountered at different altitudes, both low and high temperatures can affect the properties and impact behavior of composite materials. This study aims to investigate the effect of temperature and impactor diameter on the impact behavior and damage development in balanced and symmetrical CFRP laminates which were manufactured by employing vacuum bagging process with autoclave cure. Instrumented drop-weight impact testing system is used to perform the low velocity impact tests in a range of temperatures ranged from 60 down to -50 °C. Impact tests for each temperature level were conducted using three different hemispherical impactor diameters varying from 10 to 20 mm. Energy profile method is employed to determine the impact threshold energies for damage evolution. The level of impact damage is determined from the dent depth on the impacted face and delamination damage detected using ultrasonic C-Scan technique. Test results reveal that the threshold of penetration energy, main failure force and delamination area increase with impactor diameter at all temperature levels. No clear influence of temperature on the critical force thresholds could be derived. However, penetration threshold energy decreased as the temperature was lowered. Drop in the penetration threshold was more obvious with quite low temperatures. Delamination damage area increased while the temperature decreased from +60 °C to -50 °C.

  15. CFD simulation of length to diameter ratio effects on the energy separation in a vortex tube

    Directory of Open Access Journals (Sweden)

    Bramo Reza Abdol

    2011-01-01

    Full Text Available The objective of the present computational fluid dynamics analysis is an attempt to investigate the effect of length to diameter ratio on the fluid flow characteristics and energy separation phenomenon inside the Ranque-Hilsch vortex tube. In this numerical study, performance of Ranque-Hilsch vortex tubes (RHVT, with length to diameter ratios (L/D of 8, 9.3, 10.5, 20.2, 30.7 and 35 with six straight nozzles was investigated. It includes generating better understanding of the effects of the stagnation point location on the performance of RHVT. It was found that the best performance was obtained when the ratio of vortex tube length to the diameter was 9.3 and also fort this case the stagnation point was found to be the farthest from the inlet. The results show that the closer distance to the hot end is produced the larger magnitude of the temperature difference. Computed results show good agreement with published experimental results.

  16. Relationship between the Apical Preparation Diameter and the Apical Seal: An In Vitro Study

    Directory of Open Access Journals (Sweden)

    Kaoutar Laslami

    2018-01-01

    Full Text Available Objectives. The aim of the study is to define the relationship between the apical preparation diameter and the apical sealing ability to highlight the importance of the preservation of the diameter and the original position of the apical foramen. Materials and Methods. 50 extracted maxillary incisors were randomly allocated into three groups of 15 teeth each (n = 15 according to the apical preparation size: Group 1: finishing file F1 corresponding to size 20 reached the working length (ProTaper Universal system Dentsply®; Group 2: prepared up to size 30 corresponding to finishing file F30; Group 3: prepared up to size 50 corresponding to finishing file F5. Five teeth were assigned to positive and negative control groups. After the filling of the root canals, the teeth were isolated and immersed in a dye solution, then cut longitudinally, photographed, and the dye penetration were calculated using a computer software. Results. Comparison of the three different apical preparation sizes showed no statistically significant differences regarding the apical microleakage. Conclusion. The most important value of the dye penetration was observed in the group with the largest apical diameter.

  17. The Actin-Binding Protein α-Adducin Is Required for Maintaining Axon Diameter

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    Sérgio Carvalho Leite

    2016-04-01

    Full Text Available The actin-binding protein adducin was recently identified as a component of the neuronal subcortical cytoskeleton. Here, we analyzed mice lacking adducin to uncover the function of this protein in actin rings. α-adducin knockout mice presented progressive axon enlargement in the spinal cord and optic and sciatic nerves, followed by axon degeneration and loss. Using stimulated emission depletion super-resolution microscopy, we show that a periodic subcortical actin cytoskeleton is assembled in every neuron type inspected including retinal ganglion cells and dorsal root ganglia neurons. In neurons devoid of adducin, the actin ring diameter increased, although the inter-ring periodicity was maintained. In vitro, the actin ring diameter adjusted as axons grew, suggesting the lattice is dynamic. Our data support a model in which adducin activity is not essential for actin ring assembly and periodicity but is necessary to control the diameter of both actin rings and axons and actin filament growth within rings.

  18. Experimental Investigation of Minimum Quantity Lubrication in Meso-scale Milling with Varying Tool Diameter

    Science.gov (United States)

    Yusof, M. Q. M.; Harun, H. N. S. B.; Bahar, R.

    2018-01-01

    Minimum quantity lubrication (MQL) is a method that uses a very small amount of liquid to reduce friction between cutting tool and work piece during machining. The implementation of MQL machining has become a viable alternative to flood cooling machining and dry machining. The overall performance has been evaluated during meso-scale milling of mild steel using different diameter milling cutters. Experiments have been conducted under two different lubrication condition: dry and MQL with variable cutting parameters. The tool wear and its surface roughness, machined surfaces microstructure and surface roughness were observed for both conditions. It was found from the results that MQL produced better results compared to dry machining. The 0.5 mm tool has been selected as the most optimum tool diameter to be used with the lowest surface roughness as well as the least flank wear generation. For the workpiece, it was observed that the cutting temperature possesses crucial effect on the microstructure and the surface roughness of the machined surface and bigger diameter tool actually resulted in higher surface roughness. The poor conductivity of the cutting tool may be one of reasons behind.

  19. Infant Pupil Diameter Changes in Response to Others' Positive and Negative Emotions

    Science.gov (United States)

    Geangu, Elena; Hauf, Petra; Bhardwaj, Rishi; Bentz, Wolfram

    2011-01-01

    It has been suggested that infants resonate emotionally to others' positive and negative affect displays, and that these responses become stronger towards emotions with negative valence around the age of 12-months. In this study we measured 6- and 12-month-old infants' changes in pupil diameter when presented with the image and sound of peers experiencing happiness, distress and an emotionally neutral state. For all participants the perception of another's distress triggered larger pupil diameters. Perceiving other's happiness also induced larger pupil diameters but for shorter time intervals. Importantly, we also found evidence for an asymmetry in autonomous arousal towards positive versus negative emotional displays. Larger pupil sizes for another's distress compared to another's happiness were recorded shortly after stimulus onset for the older infants, and in a later time window for the 6-month-olds. These findings suggest that arousal responses for negative as well as for positive emotions are present in the second half of the first postnatal year. Importantly, an asymmetry with stronger responses for negative emotions seems to be already present at this age. PMID:22110605

  20. Ageing effects on the diameter, nanomechanical properties and tactile perception of human hair.

    Science.gov (United States)

    Tang, W; Zhang, S G; Zhang, J K; Chen, S; Zhu, H; Ge, S R

    2016-04-01

    The typical changes to hair associated with ageing are greying, thinning, dryness and brittleness. Research on the influence of ageing on hair properties will enable a detailed understanding of the natural ageing process. The studies were carried out using an SEM (scanning electron microscope), a TriboIndenter and an artificial finger. Three characteristic features of tactile perception that could reflect the perceptual dimensions of the fineness, roughness and slipperiness of hair were extracted. The influences of ageing on the diameter, surface topography, nanomechanical properties and tactile perception of hair were determined. In the three age group hair samples, the children's group hair samples have the smallest diameter. The hair cuticles in the children and young adult groups were relatively complete and less damaged than in the elderly group. The hardness and elastic modulus of the young adult group's hair samples were higher than those in the elderly and children's groups. For all groups, loss modulus E" was smaller than storage modulus E'. Vertical deviations (R) and coefficient of friction (μ) increased, and spectral centroid (SC) decreased, with the increase in age. Ageing decreased the tactile perception of hair. Ageing influences the diameter, surface topography, hardness, loss modulus, storage modulus and tactile perception of human hair. © 2015 Society of Cosmetic Scientists and the Société Française de Cosmétologie.