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Sample records for vessel size measurements

  1. MR evaluation of vessel size imaging of human gliomas: Validation by histopathology.

    Science.gov (United States)

    Kellner, Elias; Breyer, Tobias; Gall, Peter; Müller, Klaus; Trippel, Michael; Staszewski, Ori; Stein, Florian; Saborowski, Olaf; Dyakova, Olga; Urbach, Horst; Kiselev, Valerij G; Mader, Irina

    2015-10-01

    To compare the vessel size and the cerebral blood volume in human gliomas with histopathology. Vessel size imaging (VSI) is a dynamic susceptibility contrast method for the assessment of the vessel size in normal and pathological tissue. Previous publications in rodents showed a satisfactory conformity with the vessel size derived from histopathology. To assess the clinical value, further, the progression-free interval was determined and correlated. Twenty-five gliomas (WHO grade °II [n = 10], °III [n = 3], °IV [n = 12]) were prospectively included and received a stereotaxic biopsy after VSI. The vessel size and the cerebral blood volume (CBV) were calculated in regions of interest at the tumor edge and correlated with the vessel size measured by histopathology. Both VSI and CBV showed a good correlation with the vessel size in histopathology (up to r = 0.84, P histopathology is in good accordance with the animal studies. The overestimation of small capillary sizes is also known from the animal trials. Vessel size and CBV showed similar results, both for the correlation with the histopathological vessel size and the progression-free interval. © 2014 Wiley Periodicals, Inc.

  2. Combretastatin A-4 Phosphate Affects Tumor Vessel Volume and Size Distribution as Assessed Using MRI-Based Vessel Size Imaging

    NARCIS (Netherlands)

    Nielsen, T.; Bentzen, L.; Pedersen, M.; Tramm, T.; Rijken, P.F.J.W.; Bussink, J.; Horsman, M.R.; Ostergaard, L.

    2012-01-01

    PURPOSE: Combretastatin A-4 disodium phosphate (CA4P) is a promising vascular disrupting agent (VDA) in clinical trials. As CA4P acts on dividing endothelial cells, we hypothesize that CA4P affects vessels of certain sizes. The aim of this study was to evaluate the effect of CA4P by the MRI-based

  3. Size segregated aerosol mass concentration measurements over ...

    Indian Academy of Sciences (India)

    Mass concentration and mass size distribution of total (composite) aerosols near the surface are essential inputs needed in developing aerosol models for radiative forcing estimation as well as to infer the environment and air quality. Using extensive measurements onboard the oceanographic research vessel, Sagar Kanya ...

  4. The clinical impact of mean vessel size and solidity in breast carcinoma patients.

    Directory of Open Access Journals (Sweden)

    Lars Tore Gyland Mikalsen

    Full Text Available Angiogenesis quantification, through vessel counting or area estimation in the most vascular part of the tumour, has been found to be of prognostic value across a range of carcinomas, breast cancer included. We have applied computer image analysis to quantify vascular properties pertaining to size, shape and spatial distributions in photographed fields of CD34 stained sections. Aided by a pilot (98 cases, seven parameters were selected and validated on a separate set from 293 breast cancer patients. Two new prognostic markers were identified through continuous cox regression with endpoints breast cancer specific survival and distant disease free survival: The average size of the vessels as measured by their perimeter (p = 0.003 and 0.004, respectively, and the average complexity of the vessel shapes measured by their solidity (p = 0.004 and 0.004. The Hazard ratios for the corresponding median-dichotomized markers were 2.28 (p = 0.005 and 1.89 (p = 0.016 for the mean perimeter and 1.80 (p = 0.041 and 1.55 (p = 0.095 for the shape complexity. The markers were associated with poor histologic type, high grade, necrosis, HR negativity, inflammation, and p53 expression (vessel size only. Both markers were found to strongly influence the prognostic properties of vascular invasion (VI and disseminated tumour cells in the bone marrow. The latter being prognostic only in cases with large vessels (p = 0.004 and 0.043 or low complexity (p = 0.018 and 0.024, but not in the small or complex vessel groups (p>0.47. VI was significant in all groups, but showed greater hazard ratios for small and low complexity vessels (6.54-11.2 versus large and high complexity vessels (2.64-3.06. We find that not only the overall amount of produced vasculature in angiogenic hot-spots is of prognostic significance, but also the morphological appearance of the generated vessels, i.e. the size and shape of vessels in the studied hot spots.

  5. Stress Rupture Life Reliability Measures for Composite Overwrapped Pressure Vessels

    Science.gov (United States)

    Murthy, Pappu L. N.; Thesken, John C.; Phoenix, S. Leigh; Grimes-Ledesma, Lorie

    2007-01-01

    Composite Overwrapped Pressure Vessels (COPVs) are often used for storing pressurant gases onboard spacecraft. Kevlar (DuPont), glass, carbon and other more recent fibers have all been used as overwraps. Due to the fact that overwraps are subjected to sustained loads for an extended period during a mission, stress rupture failure is a major concern. It is therefore important to ascertain the reliability of these vessels by analysis, since the testing of each flight design cannot be completed on a practical time scale. The present paper examines specifically a Weibull statistics based stress rupture model and considers the various uncertainties associated with the model parameters. The paper also examines several reliability estimate measures that would be of use for the purpose of recertification and for qualifying flight worthiness of these vessels. Specifically, deterministic values for a point estimate, mean estimate and 90/95 percent confidence estimates of the reliability are all examined for a typical flight quality vessel under constant stress. The mean and the 90/95 percent confidence estimates are computed using Monte-Carlo simulation techniques by assuming distribution statistics of model parameters based also on simulation and on the available data, especially the sample sizes represented in the data. The data for the stress rupture model are obtained from the Lawrence Livermore National Laboratories (LLNL) stress rupture testing program, carried out for the past 35 years. Deterministic as well as probabilistic sensitivities are examined.

  6. Smooth muscle cell recruitment to lymphatic vessels requires PDGFB and impacts vessel size but not identity.

    Science.gov (United States)

    Wang, Yixin; Jin, Yi; Mäe, Maarja Andaloussi; Zhang, Yang; Ortsäter, Henrik; Betsholtz, Christer; Mäkinen, Taija; Jakobsson, Lars

    2017-10-01

    Tissue fluid drains through blind-ended lymphatic capillaries, via smooth muscle cell (SMC)-covered collecting vessels into venous circulation. Both defective SMC recruitment to collecting vessels and ectopic recruitment to lymphatic capillaries are thought to contribute to vessel failure, leading to lymphedema. However, mechanisms controlling lymphatic SMC recruitment and its role in vessel maturation are unknown. Here, we demonstrate that platelet-derived growth factor B (PDGFB) regulates lymphatic SMC recruitment in multiple vascular beds. PDGFB is selectively expressed by lymphatic endothelial cells (LECs) of collecting vessels. LEC-specific deletion of Pdgfb prevented SMC recruitment causing dilation and failure of pulsatile contraction of collecting vessels. However, vessel remodelling and identity were unaffected. Unexpectedly, Pdgfb overexpression in LECs did not induce SMC recruitment to capillaries. This was explained by the demonstrated requirement of PDGFB extracellular matrix (ECM) retention for lymphatic SMC recruitment, and the low presence of PDGFB-binding ECM components around lymphatic capillaries. These results demonstrate the requirement of LEC-autonomous PDGFB expression and retention for SMC recruitment to lymphatic vessels, and suggest an ECM-controlled checkpoint that prevents SMC investment of capillaries, which is a common feature in lymphedematous skin. © 2017. Published by The Company of Biologists Ltd.

  7. Smooth muscle cell recruitment to lymphatic vessels requires PDGFB and impacts vessel size but not identity

    Science.gov (United States)

    Wang, Yixin; Jin, Yi; Mäe, Maarja Andaloussi; Zhang, Yang; Ortsäter, Henrik; Betsholtz, Christer; Mäkinen, Taija

    2017-01-01

    Tissue fluid drains through blind-ended lymphatic capillaries, via smooth muscle cell (SMC)-covered collecting vessels into venous circulation. Both defective SMC recruitment to collecting vessels and ectopic recruitment to lymphatic capillaries are thought to contribute to vessel failure, leading to lymphedema. However, mechanisms controlling lymphatic SMC recruitment and its role in vessel maturation are unknown. Here, we demonstrate that platelet-derived growth factor B (PDGFB) regulates lymphatic SMC recruitment in multiple vascular beds. PDGFB is selectively expressed by lymphatic endothelial cells (LECs) of collecting vessels. LEC-specific deletion of Pdgfb prevented SMC recruitment causing dilation and failure of pulsatile contraction of collecting vessels. However, vessel remodelling and identity were unaffected. Unexpectedly, Pdgfb overexpression in LECs did not induce SMC recruitment to capillaries. This was explained by the demonstrated requirement of PDGFB extracellular matrix (ECM) retention for lymphatic SMC recruitment, and the low presence of PDGFB-binding ECM components around lymphatic capillaries. These results demonstrate the requirement of LEC-autonomous PDGFB expression and retention for SMC recruitment to lymphatic vessels, and suggest an ECM-controlled checkpoint that prevents SMC investment of capillaries, which is a common feature in lymphedematous skin. PMID:28851707

  8. Boosted learned kernels for data-driven vesselness measure

    Science.gov (United States)

    Grisan, E.

    2017-03-01

    Common vessel centerline extraction methods rely on the computation of a measure providing the likeness of the local appearance of the data to a curvilinear tube-like structure. The most popular techniques rely on empirically designed (hand crafted) measurements as the widely used Hessian vesselness, the recent oriented flux tubeness or filters (e.g. the Gaussian matched filter) that are developed to respond to local features, without exploiting any context information nor the rich structural information embedded in the data. At variance with the previously proposed methods, we propose a completely data-driven approach for learning a vesselness measure from expert-annotated dataset. For each data point (voxel or pixel), we extract the intensity values in a neighborhood region, and estimate the discriminative convolutional kernel yielding a positive response for vessel data and negative response for non-vessel data. The process is iterated within a boosting framework, providing a set of linear filters, whose combined response is the learned vesselness measure. We show the results of the general-use proposed method on the DRIVE retinal images dataset, comparing its performance against the hessian-based vesselness, oriented flux antisymmetry tubeness, and vesselness learned with a probabilistic boosting tree or with a regression tree. We demonstrate the superiority of our approach that yields a vessel detection accuracy of 0.95, with respect to 0.92 (hessian), 0.90 (oriented flux) and 0.85 (boosting tree).

  9. Interpretation of Strain Measurements on Nuclear Pressure Vessels

    DEFF Research Database (Denmark)

    Andersen, Svend Ib Smidt; Engbæk, Preben

    1980-01-01

    Selected results from strain measurements on four nuclear pressure vessels are presented and discussed. The measurements were made in several different regions of the vessels: transition zones in vessel heads, flanges and bottom parts, nozzles, internal vessel structure and flange bolts. The resu......Selected results from strain measurements on four nuclear pressure vessels are presented and discussed. The measurements were made in several different regions of the vessels: transition zones in vessel heads, flanges and bottom parts, nozzles, internal vessel structure and flange bolts....... The results presented are based on data obtained by approximately 700 strain-gauges, and a comprehensive knowledge of the quality obtained by such measurements is established. It is shown that a thorough control procedure before and after the test as well as a detailed knowledge of the behaviour of the signal...... from the individual gauges during the test is necessary. If this is omitted, it can be extremely difficult to distinguish between the real structural behaviour and a malfunctioning of a specific gauge installation. In general, most of the measuring results exhibit a very linear behaviour...

  10. Measuring the Sizes of Stars

    Indian Academy of Sciences (India)

    Stars, other than the Sun, appear to our unaided eyes aspoints of light. Large telescopes show an image whose sizeis dictated by refractive index irregularities in the Earth's atmosphere.The size of this blurring is much greater than thatof the star, and hence it is difficult to measure the stellar size.Fizeau showed how one ...

  11. A Measure of Similarity Between Trajectories of Vessels

    Directory of Open Access Journals (Sweden)

    Le QI

    2016-03-01

    Full Text Available The measurement of similarity between trajectories of vessels is one of the kernel problems that must be addressed to promote the development of maritime intelligent traffic system (ITS. In this study, a new model of trajectory similarity measurement was established to improve the data processing efficiency in dynamic application and to reflect actual sailing behaviors of vessels. In this model, a feature point detection algorithm was proposed to extract feature points, reduce data storage space and save computational resources. A new synthesized distance algorithm was also created to measure the similarity between trajectories by using the extracted feature points. An experiment was conducted to measure the similarity between the real trajectories of vessels. The growth of these trajectories required measurements to be conducted under different voyages. The results show that the similarity measurement between the vessel trajectories is efficient and correct. Comparison of the synthesized distance with the sailing behaviors of vessels proves that results are consistent with actual situations. The experiment results demonstrate the promising application of the proposed model in studying vessel traffic and in supplying reliable data for the development of maritime ITS.

  12. Automated measurement of diatom size

    Science.gov (United States)

    Spaulding, Sarah A.; Jewson, David H.; Bixby, Rebecca J.; Nelson, Harry; McKnight, Diane M.

    2012-01-01

    Size analysis of diatom populations has not been widely considered, but it is a potentially powerful tool for understanding diatom life histories, population dynamics, and phylogenetic relationships. However, measuring cell dimensions on a light microscope is a time-consuming process. An alternative technique has been developed using digital flow cytometry on a FlowCAM® (Fluid Imaging Technologies) to capture hundreds, or even thousands, of images of a chosen taxon from a single sample in a matter of minutes. Up to 30 morphological measures may be quantified through post-processing of the high resolution images. We evaluated FlowCAM size measurements, comparing them against measurements from a light microscope. We found good agreement between measurement of apical cell length in species with elongated, straight valves, including small Achnanthidium minutissimum (11-21 µm) and largeDidymosphenia geminata (87–137 µm) forms. However, a taxon with curved cells, Hannaea baicalensis (37–96 µm), showed differences of ~ 4 µm between the two methods. Discrepancies appear to be influenced by the choice of feret or geodesic measurement for asymmetric cells. We describe the operating conditions necessary for analysis of size distributions and present suggestions for optimal instrument conditions for size analysis of diatom samples using the FlowCAM. The increased speed of data acquisition through use of imaging flow cytometers like the FlowCAM is an essential step for advancing studies of diatom populations.

  13. Use of commercial vessels in survey augmentation: the size-frequency distribution

    Directory of Open Access Journals (Sweden)

    Eric N. Powell

    2006-09-01

    Full Text Available The trend towards use of commercial vessels to enhance survey data requires assessment of the advantages and limitations of various options for their use. One application is to augment information on size-frequency distributions obtained in multispecies trawl surveys where stratum boundaries and sampling density are not optimal for all species. Analysis focused on ten recreationally and commercially important species: bluefish, butterfish, Loligo squid, weakfish, summer flounder, winter flounder, silver hake (whiting, black sea bass, striped bass, and scup (porgy. The commercial vessel took 59 tows in the sampled domain south of Long Island, New York and the survey vessel 18. Black sea bass, Loligo squid, and summer flounder demonstrated an onshore-offshore gradient such that smaller fish were caught disproportionately inshore and larger fish offshore. Butterfish, silver hake, and weakfish were characterized by a southwest-northeast gradient such that larger fish were caught disproportionately northeast of the southwestern-most sector. All sizes of scup, striped bass, and bluefish were caught predominately inshore. Winter flounder were caught predominately offshore. The commercial vessel was characterized by an increased frequency of large catches for most species. Consequently, patchiness was assayed to be higher by the commercial vessel in nearly all cases. The size-frequency distribution obtained by the survey vessel for six of the ten species, bluefish, butterfish, Loligo squid, summer flounder, weakfish, and silver hake, could not be obtained by chance from the size-frequency distribution obtained by the commercial vessel. The difference in sample density did not significantly influence the size-frequency distribution. Of the six species characterized by significant differences in size-frequency distribution between boats, all but one was patchy at the population level and all had one or more size classes so characterized. Although the

  14. Analysis and Measurement of NOx Emissions in Port Auxiliary Vessels

    Directory of Open Access Journals (Sweden)

    German de Melo Rodriguez

    2013-09-01

    Full Text Available This paper is made NOx pollution emitted by port auxiliary vessels, specifically by harbour tugs, due to its unique operating characteristics of operation, require a large propulsion power changes discontinuously, also possess some peculiar technical characteristics, large tonnage and high propulsive power, that differentiate them from other auxiliary vessels of the port. Taking into account all the above features, there are no studies of the NOx emission engines caused by different working regimes of power because engine manufacturers have not measured these emissions across the range of operating power, but usually we only report the pollution produced by its engines to a maximum continuous power.

  15. Neuroradiologic Characteristics of Primary Angiitis of the Central Nervous System According to the Affected Vessel Size.

    Science.gov (United States)

    Thaler, Christian; Kaufmann-Bühler, Ann-Katrin; Gansukh, Tserenchunt; Gansukh, Amarjargal; Schuster, Simon; Bachmann, Henrike; Thomalla, Götz; Magnus, Tim; Matschke, Jakob; Fiehler, Jens; Siemonsen, Susanne

    2017-09-05

    Magnetic resonance imaging (MRI) has an important impact in diagnosing primary angiitis of the central nervous system (PACNS). However, neuroradiologic findings may vary immensely, making an easy and definite diagnosis challenging. In this retrospective, single center study, we analyzed neuroradiologic findings of patients with PACNS diagnosed at our hospital between 2009 and 2014. Furthermore, we classified patients according to the affected vessel size and compared imaging characteristics between the subgroups. Thirty-three patients were included (mean age 43 [±15.3] years, 17 females) in this study. Patients with positive angiographic findings were classified as either medium or large vessel PACNS and presented more ischemic lesions (p < 0.001) and vessel wall enhancement (p = 0.017) compared to patients with small vessel PACNS. No significant differences were detected for the distribution of contrast-enhancing lesions (parenchymal or leptomeningeal), hemorrhages, or lesions with mass effect. Twenty-five patients underwent brain biopsy. Patients with medium or large vessel PACNS were less likely to have positive biopsy results. It is essential to differentiate between small and medium/large vessel PACNS since results in MRI, digital subtraction angiography and brain biopsy may differ immensely. Since image quality of MR scanners improves gradually and brain biopsy may often be nonspecific or negative, our results emphasize the importance of MRI/MRA in the diagnosis process of PACNS.

  16. Compressibility measurements of gases using externally heated pressure vessels.

    Science.gov (United States)

    Presnall, D. C.

    1971-01-01

    Most of the data collected under conditions of high temperature and pressure have been determined using a thick-walled bomb of carefully measured and fixed volume which is externally heated by an electric furnace or a thermostatically controlled bath. There are numerous variations on the basic method depending on the pressure-temperature range of interest, and the particular gas or gas mixture being studied. The construction and calibration of the apparatus is discussed, giving attention to the pressure vessel, the volume of the bomb, the measurement of pressure, the control and measurement of temperature, and the measurement of the amount and composition of gas in the bomb.

  17. 33 CFR 104.280 - Security measures for delivery of vessel stores and bunkers.

    Science.gov (United States)

    2010-07-01

    ... vessel stores and bunkers. 104.280 Section 104.280 Navigation and Navigable Waters COAST GUARD... § 104.280 Security measures for delivery of vessel stores and bunkers. (a) General. The vessel owner or operator must ensure that security measures relating to the delivery of vessel stores and bunkers are...

  18. Effect of a soluble surfactant on a finite sized bubble motion in a blood vessel

    Science.gov (United States)

    Swaminathan, T. N.; Mukundakrishnan, K.; Ayyaswamy, P. S.; Eckmann, D. M.

    2009-01-01

    We present detailed results for the motion of a finite sized gas bubble in a blood vessel. The bubble (dispersed phase) size is taken to be such as to nearly occlude the vessel. The bulk medium is treated as a shear thinning Casson fluid and contains a soluble surfactant that adsorbs and desorbs from the interface. Three different vessel sizes, corresponding to a small artery, a large arteriole, and a small arteriole, in normal humans, are considered. The hematocrit (volume fraction of RBCs) has been taken to be 0.45. For arteriolar flow, where relevant, the Fahraeus-Lindqvist effect is taken into account. Bubble motion cause temporal and spatial gradients of shear stress at the cell surface lining the vessel wall as the bubble approaches the cell, moves over it and passes it by. Rapid reversals occur in the sign of the shear stress imparted to the cell surface during this motion. Shear stress gradients together with sign reversals are associated with a recirculation vortex at the rear of the moving bubble. The presence of the surfactant reduces the level of the shear stress gradients imparted to the cell surface as compared to an equivalent surfactant-free system. Our numerical results for bubble shapes and wall shear stresses may help explain phenomena observed in experimental studies related to gas embolism, a significant problem in cardiac surgery and decompression sickness. PMID:20305744

  19. Grading vascularity from histopathological images based on traveling salesman distance and vessel size

    Science.gov (United States)

    Niazi, M. Khalid Khan; Hemminger, Jessica; Kurt, Habibe; Lozanski, Gerard; Gurcan, Metin

    2014-03-01

    Vascularity represents an important element of tissue/tumor microenvironment and is implicated in tumor growth, metastatic potential and resistence to therapy. Small blood vessels can be visualized using immunohistochemical stains specific to vascular cells. However, currently used manual methods to assess vascular density are poorly reproducible and are at best semi quantitative. Computer based quantitative and objective methods to measure microvessel density are urgently needed to better understand and clinically utilize microvascular density information. We propose a new method to quantify vascularity from images of bone marrow biopsies stained for CD34 vascular lining cells protein as a model. The method starts by automatically segmenting the blood vessels by methods of maxlink thresholding and minimum graph cuts. The segmentation is followed by morphological post-processing to reduce blast and small spurious objects from the bone marrow images. To classify the images into one of the four grades, we extracted 20 features from the segmented blood vessel images. These features include first four moments of the distribution of the area of blood vessels, first four moments of the distribution of 1) the edge weights in the minimum spanning tree of the blood vessels, 2) the shortest distance between blood vessels, 3) the homogeneity of the shortest distance (absolute difference in distance between consecutive blood vessels along the shortest path) between blood vessels and 5) blood vessel orientation. The method was tested on 26 bone marrow biopsy images stained with CD34 IHC stain, which were evaluated by three pathologists. The pathologists took part in this study by quantifying blood vessel density using gestalt assessment in hematopoietic bone marrow portions of bone marrow core biopsies images. To determine the intra-reader variability, each image was graded twice by each pathologist with two-week interval in between their readings. For each image, the ground

  20. Evaluation of detectable defect size for inner defect of pressure vessel using laser speckle

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kyeoung Suk; Seon, Sang Woo; Choi, Tae Ho; Kang, Chan Geun; Na, Man Gyun; Jung, Hyun Chul [Chsoun University, Gwangju (Korea, Republic of)

    2014-04-15

    Pressure vessels are used in various industrial fields. If a defect occurs on the inner or outer surface of a pressure vessel, it may cause a massive accident. A defect on the outer surface can be detected by visual inspection. However, a defect on the inner surface is generally impossible to detect with visual inspection. Nondestructive testing can be used to detect this type of defect. Laser speckle shearing interferometry is one nondestructive testing method that can optically detect a defect; its advantages include noncontact, full field, and real time inspection. This study evaluated the detectable size for an internal defect of a pressure vessel. The material of the pressure vessel was ASTM A53 Gr.B. The internal defect was detected when the pressure vessel was loaded by internal pressure controlled by a pneumatic system. The internal pressure was controlled from 0.2 MPa to 0.6 MPa in increments of 0.2 MPa. The results confirmed that an internal defect with a 25 % defect depth could be detected even at 0.2 MPa pressure variation.

  1. The impact of vessel size on vulnerability curves: data and models for within-species variability in saplings of aspen, Populus tremuloides Michx.

    Science.gov (United States)

    Cai, Jing; Tyree, Melvin T

    2010-07-01

    The objective of this study was to quantify the relationship between vulnerability to cavitation and vessel diameter within a species. We measured vulnerability curves (VCs: percentage loss hydraulic conductivity versus tension) in aspen stems and measured vessel-size distributions. Measurements were done on seed-grown, 4-month-old aspen (Populus tremuloides Michx) grown in a greenhouse. VCs of stem segments were measured using a centrifuge technique and by a staining technique that allowed a VC to be constructed based on vessel diameter size-classes (D). Vessel-based VCs were also fitted to Weibull cumulative distribution functions (CDF), which provided best-fit values of Weibull CDF constants (c and b) and P(50) = the tension causing 50% loss of hydraulic conductivity. We show that P(50) = 6.166D(-0.3134) (R(2) = 0.995) and that b and 1/c are both linear functions of D with R(2) > 0.95. The results are discussed in terms of models of VCs based on vessel D size-classes and in terms of concepts such as the 'pit area hypothesis' and vessel pathway redundancy.

  2. Robust MR assessment of cerebral blood volume and mean vessel size using SPION-enhanced ultrashort echo acquisition.

    Science.gov (United States)

    Han, S H; Cho, J H; Jung, H S; Suh, J Y; Kim, J K; Kim, Y R; Cho, G; Cho, H

    2015-05-15

    Intravascular superparamagnetic iron oxide nanoparticles (SPION)-enhanced MR transverse relaxation rates (∆R2(⁎) and ∆R2) are widely used to investigate in vivo vascular parameters, such as the cerebral blood volume (CBV), microvascular volume (MVV), and mean vessel size index (mVSI, ∆R2(⁎)/∆R2). Although highly efficient, regional comparison of vascular parameters acquired using gradient-echo based ∆R2(⁎) is hampered by its high sensitivity to magnetic field perturbations arising from air-tissue interfaces and large vessels. To minimize such demerits, we took advantage of the dual contrast property of SPION and both theoretically and experimentally verified the direct benefit of replacing gradient-echo based ∆R2(⁎) measurement with ultra-short echo time (UTE)-based ∆R1 contrast to generate the robust CBV and mVSI maps. The UTE acquisition minimized the local measurement errors from susceptibility perturbations and enabled dose-independent CBV measurement using the vessel/tissue ∆R1 ratio, while independent spin-echo acquisition enabled simultaneous ∆R2 measurement and mVSI calculation of the cortex, cerebellum, and olfactory bulb, which are animal brain regions typified by significant susceptibility-associated measurement errors. Copyright © 2015 Elsevier Inc. All rights reserved.

  3. Optical Measurement Technology for Calibratiing Inner Defects of Pressure Vessel

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sang Do; Chang, Seog Weon; Jhang, Kyung Young [Hanyang University, Seoul (Korea, Republic of)

    2005-04-15

    The pressure vessel may have crucial defects in its inner surfaces, which can be more dangerous than those in outer surfaces because the inner defects can hardly be measured or calibrated. Conventional methods for detecting or measuring the inner defects of pressure vessel have been utilizing ultrasonic, X-ray or eddy current. But the conventional NDE(Non-Destructive-Evaluation) methods are applied to limited area or environment because the prove or film must be located close to the objects although the methods are NDE tools. Recently, optical measurement technologies for detecting the inner defects such as cracks, flaws or corrosions are utilized very much. The optical measurement technologies are known as much useful as to have the capabilities of short working time, non-contact and full-field measurement. Among them, shearography is considered to be one of the most available tools, because of its feature of not requiring strict environmental stability, which is essential to other optical tools. In this study, the availability of the optical measurement technology using shearography for detecting and calibrating the inner defects is verified.

  4. Trabeculectomy Improves Vessel Response Measured by Dynamic Vessel Analysis (DVA) in Glaucoma Patients.

    Science.gov (United States)

    J, Michael Selbach; Schallenberg, Maurice; Kramer, Sebastian; Anastassiou, Gerasimos; Steuhl, Klaus-Peter; Vilser, Walthard; Kremmer, Stephan

    2014-01-01

    To determine the effects of surgical IOP reduction (trabeculectomy) on retinal blood flow parameters in glaucoma patients using Dynamic Vessel Analysis (DVA). 26 eyes of 26 patients with progressive primary open-angle glaucoma (POAG) despite maximal topical therapy were examined before and after trabeculectomy. The responses of the retinal vessels to flickering light provocation were measured with DVA the day before surgery and 4 to 6 weeks after trabeculectomy. Between 3 and 4 weeks before surgery all local therapies were stopped and a systemic therapy with acetazolamide and conservative free topic steroidal eye drops was started. In 19 patients (73%), an inadequate response to the flicker stimulation was measured preoperatively. In these patients, the maximum dilation of arteries and veins was reduced significantly as compared to healthy eyes. In this group, the maximum dilation of the arteries following the flicker provocation improved from 1.4% before to 3.8% following trabeculectomy (p<0.01). In retinal veins, this parameter increased from 3.1% to 4.6% (p<0.05). In the 7 patients whose arterial and venous reactions to flickering light provocation preoperatively did not differ from healthy eyes, there was no significant change after surgery. The initial baseline values of arteries and veins (MU) did not deviate significantly in both groups. POAG patients with progressive disease and impaired vascular regulation profit from IOP lowering trabeculectomy concerning vascular reactivity and dilative reserve, indicating a possible improvement of retinal perfusion following effective IOP control. Future studies with long-term follow-up must determine the clinical importance of these findings for the treatment of glaucoma patients.

  5. Retinal vessel centerline extraction using multiscale matched filters, confidence and edge measures.

    Science.gov (United States)

    Sofka, Michal; Stewart, Charles V

    2006-12-01

    Motivated by the goals of improving detection of low-contrast and narrow vessels and eliminating false detections at nonvascular structures, a new technique is presented for extracting vessels in retinal images. The core of the technique is a new likelihood ratio test that combines matched-filter responses, confidence measures and vessel boundary measures. Matched filter responses are derived in scale-space to extract vessels of widely varying widths. A vessel confidence measure is defined as a projection of a vector formed from a normalized pixel neighborhood onto a normalized ideal vessel profile. Vessel boundary measures and associated confidences are computed at potential vessel boundaries. Combined, these responses form a six-dimensional measurement vector at each pixel. A training technique is used to develop a mapping of this vector to a likelihood ratio that measures the "vesselness" at each pixel. Results comparing this vesselness measure to matched filters alone and to measures based on the Hessian of intensities show substantial improvements, both qualitatively and quantitatively. The Hessian can be used in place of the matched filter to obtain similar but less-substantial improvements or to steer the matched filter by preselecting kernel orientations. Finally, the new vesselness likelihood ratio is embedded into a vessel tracing framework, resulting in an efficient and effective vessel centerline extraction algorithm.

  6. Measurement of contrast of phantom and in vivo subsurface blood vessels using two near-infrared imaging systems

    Science.gov (United States)

    Hebden, Jeremy C.; Alkhaja, Aysha; Mahe, Laure; Powell, S.; Everdell, N. L.

    2015-03-01

    A quantitative comparison has been performed between two commercial near-infrared (NIR) vein-viewing systems which are designed to supplement the clinician's traditional skills in locating veins by means of visualization and palpation. The AccuVein AV300 and Novarix IV-eye real-time imaging systems employ very different imaging geometries; the former generates an image from reflected NIR light produced by a beam scanned across the surface, while the latter illuminates the viewed region at four points on the periphery and records the resulting distribution of diffusely transmitted light. The comparison involved measuring the contrast produced by absorbing rods (simulated blood vessels) in a cylindrical phantom with tissue-like optical properties, and the contrast of superficial blood vessels in the arms of healthy volunteers. The locations and sizes of the blood vessels were independently verified using a clinical ultrasound imaging system. The phantom measurements suggested that the AV300 displays the most superficial vessels with greater contrast, but the IV-eye is able to detect vessels when they are at a depth up to 2 mm greater than the limit observed for the AV300. The results for thirty healthy volunteers also indicated that the AV300 typically displays vessels with higher overall contrast, but the effectiveness of the IV-eye at visualizing deeper vessels was even more pronounced, with a maximum depth several millimeters greater than that achieved by the AV300, and more than ten times as many vessels observed at depths below 4 mm.

  7. 33 CFR 105.270 - Security measures for delivery of vessel stores and bunkers.

    Science.gov (United States)

    2010-07-01

    ... vessel stores and bunkers. 105.270 Section 105.270 Navigation and Navigable Waters COAST GUARD... Requirements § 105.270 Security measures for delivery of vessel stores and bunkers. (a) General. The facility owner or operator must ensure that security measures relating to the delivery of vessel stores and...

  8. Retinal vessel detection and measurement for computer-aided medical diagnosis.

    Science.gov (United States)

    Li, Xiaokun; Wee, William G

    2014-02-01

    Since blood vessel detection and characteristic measurement for ocular retinal images is a fundamental problem in computer-aided medical diagnosis, automated algorithms/systems for vessel detection and measurement are always demanded. To support computer-aided diagnosis, an integrated approach/solution for vessel detection and diameter measurement is presented and validated. In the proposed approach, a Dempster-Shafer (D-S)-based edge detector is developed to obtain initial vessel edge information and an accurate vascular map for a retinal image. Then, the appropriate path and the centerline of a vessel of interest are identified automatically through graph search. Once the vessel path has been identified, the diameter of the vessel will be measured accordingly by the algorithm in real time. To achieve more accurate edge detection and diameter measurement, mixed Gaussian-matched filters are designed to refine the initial detection and measures. Other important medical indices of retinal vessels can also be calculated accordingly based on detection and measurement results. The efficiency of the proposed algorithm was validated by the retinal images obtained from different public databases. Experimental results show that the vessel detection rate of the algorithm is 100 % for large vessels and 89.9 % for small vessels, and the error rate on vessel diameter measurement is less than 5 %, which are all well within the acceptable range of deviation among the human graders.

  9. Safety Domain Measurement for Vessels in an Overtaking Situation

    Directory of Open Access Journals (Sweden)

    Hua-Zhi Hsu

    2014-12-01

    Full Text Available Marine traffic engineering has been pushed to the limits due to a rising demand in the shipping business. Merchant ships are growing dramatically, both in numbers and in size. To keep pace with current developments, automation seems to be one viable option when it comes to keeping ships running with fewer seafarers available. The aim of this paper is to monitor a modern day mariners’ performance while working in a tense situation. The objective is to define the size of the safety domain whilst overtaking a vessel. The approach was to assess the ship's domain area within a 3 nm wide traffic separation scheme by using a ship handling simulator. From the simulation results, an overtaking domain was determined as 1.36 nm long and 0.4 nm wide. Safety domains in real-life situations were experienced on a much smaller scale compared to the previous findings. The working load for this particular operation is expected to be stressful and highly skilled orientated.

  10. Business performance measurement: Does size matter?

    Directory of Open Access Journals (Sweden)

    Mills, H.

    2016-08-01

    Full Text Available Risk reduction remains a management challenge. Research shows that business performance measurement is a popular tool to reduce risk, although applied differently across organizations. This study aimed to assess the influence of organizational size on performance measurement of market-driven organizations. A web-based survey was conducted whereby managers indicated their satisfaction with performance measurement practices, the regularity with which performance measurements were collected and the importance attached to performance measures collected. Respondents were fairly satisfied with existing performance measures, irrespective of organization size. No significant difference between organization size and respondents perception about the value placed by top management with regards to performance measurement was found. The study concludes that managers can make decisions that could ultimately reduce risk when they utilize proper performance measures

  11. INTERVERTEBRAL SIZE MEASUREMENT WITH ANTHROPOMETRIC METHOD

    Directory of Open Access Journals (Sweden)

    Zmago Turk

    2004-04-01

    Full Text Available Background. There is a positive correlation between the size of intervertebral disc (IVD and the incidence of Low Back Pain (LBP. Columbini evaluated the size of IVD anthropometricaly but how this measurement correlates with radiologic measurements of IVD square size is steel unknown.Objective. The aim of the study was to search for non-invasive method and cheap and fast evaluation of IVD size with the modification of Columbini’s antropometric formula.Materials and methods. The measurements (anthropometrics, X-ray, CT with range of interest measurement [ROI] were done on 40 bus-drivers. The realibility test was done on 65 bus-drivers.Results. CT measurement of the size of the intervertebral disc was done using ROI (Range of Interest. Using the statistical analysis based on linear regression, correlation, curve fitting and realibility the author made the modification of Columbini’s formula. The incidence of Low Back Pain was statistically significantly higher in people with smaller IVD, particularly in men.Conclusions. With the Columbini’s method of anthropometric measurement of the size of IVD modified by Turk it is possible to make the right measurement prognosis in 89% of cases. Consequently, there is no need to use invasive and costly diagnostic radiologic methods.

  12. Distribution of different sized ocular surface vessels in diabetics and normal individuals

    Directory of Open Access Journals (Sweden)

    Touka Banaee

    2017-01-01

    Conclusion: Presence of diabetes mellitus is associated with contraction of larger vessels in the conjunctiva. Smaller vessels dilate with diabetic retinopathy. These findings may be useful in the photographic screening of diabetes mellitus and retinopathy.

  13. An in situ optical imaging system for measuring lipid uptake, vessel contraction, and lymph flow in small animal lymphatic vessels

    Science.gov (United States)

    Kassis, Timothy; Weiler, Michael J.; Dixon, J. Brandon

    2012-03-01

    All dietary lipids are transported to venous circulation through the lymphatic system, yet the underlying mechanisms that regulate this process remain unclear. Understanding how the lymphatics functionally respond to changes in lipid load is important in the diagnosis and treatment of lipid and lymphatic related diseases such as obesity, hypercholesterolemia, and lymphedema. Therefore, we sought to develop an in situ imaging system to quantify and correlate lymphatic function as it relates to lipid transport. A custom-built optical set-up provides us with the capability of dual-channel imaging of both high-speed bright-field video and fluorescence simultaneously. This is achieved by dividing the light path into two optical bands. Utilizing high-speed and back-illuminated CCD cameras and post-acquisition image processing algorithms, we have the potential quantify correlations between vessel contraction, lymph flow and lipid concentration of mesenteric lymphatic vessels in situ. Local flow velocity is measured through lymphocyte tracking, vessel contraction through measurements of the vessel walls and lipid uptake through fluorescence intensity tracking of a fluorescent long chain fatty acid analogue, Bodipy FL C16. This system will prove to be an invaluable tool for both scientists studying lymphatic function in health and disease, and those investigating strategies for targeting the lymphatic system with orally delivered drugs.

  14. On-Site Oxy-Lance Size Reduction of South Texas Project Reactor Vessel Heads - 12324

    Energy Technology Data Exchange (ETDEWEB)

    Posivak, Edward [WMG, inc. (United States); Keeney, Gilbert; Wheeler, Dean [Shaw Group (United States)

    2012-07-01

    On-Site Oxy-Lance size reduction of mildly radioactive large components has been accomplished at other operating plants. On-Site Oxy-Lance size reduction of more radioactive components like Reactor Vessel Heads had previously been limited to decommissioning projects. Building on past decommissioning and site experience, subcontractors for South Texas Project Nuclear Operating Company (STPNOC) developed an innovative integrated system to control smoke, radioactive contamination, worker dose, and worker safety. STP's innovative, easy to use CEDM containment that provided oxy lance access, smoke control, and spatter/contamination control was the key to successful segmentation for cost-effective and ALARA packaging and transport for disposal. Relative to CEDM milling, STP oxy-lance segmentation saved approximately 40 person- REM accrued during 9,000 hours logged into the radiological controlled area (RCA) during more than 3,800 separate entries. Furthermore there were no personnel contamination events or respiratory uptakes of radioactive material during the course of the entire project. (authors)

  15. Proximal Occlusion of Medium-Sized Vessels with the Penumbra Occlusion Device: A Study of Safety and Efficacy.

    Science.gov (United States)

    Jambon, E; Petitpierre, F; Brizzi, V; Dubuisson, V; Le Bras, Y; Grenier, N; Cornelis, F

    2017-02-01

    To retrospectively investigate the safety and efficacy of hybrid proximal coiling of various medium-sized vessels (4 to 8 mm) using the Penumbra Occlusion Device (POD). From October 2014 to February 2016, 37 proximal embolizations were performed with PODs in 36 patients (mean age: 50.8, range: 10-86; 29 male, 7 female). Vessel occlusions were achieved under fluoroscopic guidance using a 2.7 French microcatheter. Among the 36 vessels targeted, 16 were splenic arteries, 11 renal arteries, 4 mesenteric arteries, 3 arteriovenous fistulae, 1 iliac artery, and 1 gonadal vein. Intermittent follow-up angiography was performed to assess the flow for final occlusion. Outcomes and complications were assessed by clinical and/or imaging follow-up. To produce proximal occlusion of the intended vessels, the POD was used alone in 19 embolizations (51.4 %). In 12 procedures (32.4 %), POD was used as a coil constrainer to secure the coil construct. In 6 procedures (16.2 %), additional embolic devices were used to achieve vessel occlusion after initial POD deployment. After a mean follow-up of 3.2 months, no POD migration was observed but two complications occurred (5.4 %): one post embolic syndrome and one extensive infarction with splenic abscess. The POD system allows safe and effective proximal embolization of medium-sized vessels in a variety of clinical settings.

  16. Proximal Occlusion of Medium-Sized Vessels with the Penumbra Occlusion Device: A Study of Safety and Efficacy

    Energy Technology Data Exchange (ETDEWEB)

    Jambon, E.; Petitpierre, F. [Pellegrin Hospital, Department of Radiology (France); Brizzi, V.; Dubuisson, V. [Pellegrin Hospital, Department of Surgery (France); Bras, Y. Le; Grenier, N.; Cornelis, F., E-mail: cornelisfrancois@gmail.com [Pellegrin Hospital, Department of Radiology (France)

    2017-02-15

    PurposeTo retrospectively investigate the safety and efficacy of hybrid proximal coiling of various medium-sized vessels (4 to 8 mm) using the Penumbra Occlusion Device (POD).Materials and MethodsFrom October 2014 to February 2016, 37 proximal embolizations were performed with PODs in 36 patients (mean age: 50.8, range: 10–86; 29 male, 7 female). Vessel occlusions were achieved under fluoroscopic guidance using a 2.7 French microcatheter. Among the 36 vessels targeted, 16 were splenic arteries, 11 renal arteries, 4 mesenteric arteries, 3 arteriovenous fistulae, 1 iliac artery, and 1 gonadal vein. Intermittent follow-up angiography was performed to assess the flow for final occlusion. Outcomes and complications were assessed by clinical and/or imaging follow-up.ResultsTo produce proximal occlusion of the intended vessels, the POD was used alone in 19 embolizations (51.4 %). In 12 procedures (32.4 %), POD was used as a coil constrainer to secure the coil construct. In 6 procedures (16.2 %), additional embolic devices were used to achieve vessel occlusion after initial POD deployment. After a mean follow-up of 3.2 months, no POD migration was observed but two complications occurred (5.4 %): one post embolic syndrome and one extensive infarction with splenic abscess.ConclusionThe POD system allows safe and effective proximal embolization of medium-sized vessels in a variety of clinical settings.

  17. Automated grain size measurements from airborne remote sensing for long profile measurements of fluvial grain sizes

    Science.gov (United States)

    Carbonneau, Patrice E.; Bergeron, Normand; Lane, Stuart N.

    2005-11-01

    Recent research has demonstrated that image processing can be applied to derive surficial median grain size data automatically from high-resolution airborne digital imagery in fluvial environments. However, at the present time, automated grain size measurement is limited to the dry exposed bed areas of the channel. This paper shows that the application area of automated grain size mapping can be extended in order to include the shallow wetted areas of the channel. The paper then proceeds to illustrate how automated grain size measurement in both dry and shallow wetted areas can be used to measure grain sizes automatically for long river lengths. For the present study, this results in a median grain size profile covering an 80 km long river which is constructed from over three million automated grain size measurements.

  18. Retinal vessel width measurement at branchings using an improved electric field theory-based graph approach.

    Directory of Open Access Journals (Sweden)

    Xiayu Xu

    Full Text Available The retinal vessel width relationship at vessel branch points in fundus images is an important biomarker of retinal and systemic disease. We propose a fully automatic method to measure the vessel widths at branch points in fundus images. The method is a graph-based method, in which a graph construction method based on electric field theory is applied which specifically deals with complex branching patterns. The vessel centerline image is used as the initial segmentation of the graph. Branching points are detected on the vessel centerline image using a set of detection kernels. Crossing points are distinguished from branch points and excluded. The electric field based graph method is applied to construct the graph. This method is inspired by the non-intersecting force lines in an electric field. At last, the method is further improved to give a consistent vessel width measurement for the whole vessel tree. The algorithm was validated on 100 artery branchings and 100 vein branchings selected from 50 fundus images by comparing with vessel width measurements from two human experts.

  19. Retinal vessel width measurement at branchings using an improved electric field theory-based graph approach.

    Science.gov (United States)

    Xu, Xiayu; Reinhardt, Joseph M; Hu, Qiao; Bakall, Benjamin; Tlucek, Paul S; Bertelsen, Geir; Abràmoff, Michael D

    2012-01-01

    The retinal vessel width relationship at vessel branch points in fundus images is an important biomarker of retinal and systemic disease. We propose a fully automatic method to measure the vessel widths at branch points in fundus images. The method is a graph-based method, in which a graph construction method based on electric field theory is applied which specifically deals with complex branching patterns. The vessel centerline image is used as the initial segmentation of the graph. Branching points are detected on the vessel centerline image using a set of detection kernels. Crossing points are distinguished from branch points and excluded. The electric field based graph method is applied to construct the graph. This method is inspired by the non-intersecting force lines in an electric field. At last, the method is further improved to give a consistent vessel width measurement for the whole vessel tree. The algorithm was validated on 100 artery branchings and 100 vein branchings selected from 50 fundus images by comparing with vessel width measurements from two human experts.

  20. 75 FR 1324 - Implementation of Regional Fishery Management Organizations' Measures Pertaining to Vessels that...

    Science.gov (United States)

    2010-01-11

    ... Fishery Management Organizations' Measures Pertaining to Vessels that Engaged in Illegal, Unregulated, and... have been identified by these regional fishery management organizations (RFMOs) as having engaged in... management organizations (RFMOs) and domestic laws. To promote compliance with such conservation and...

  1. Electronic cigarette aerosol particle size distribution measurements.

    Science.gov (United States)

    Ingebrethsen, Bradley J; Cole, Stephen K; Alderman, Steven L

    2012-12-01

    The particle size distribution of aerosols produced by electronic cigarettes was measured in an undiluted state by a spectral transmission procedure and after high dilution with an electrical mobility analyzer. The undiluted e-cigarette aerosols were found to have particle diameters of average mass in the 250-450 nm range and particle number concentrations in the 10(9) particles/cm(3) range. These measurements are comparable to those observed for tobacco burning cigarette smoke in prior studies and also measured in the current study with the spectral transmission method and with the electrical mobility procedure. Total particulate mass for the e-cigarettes calculated from the size distribution parameters measured by spectral transmission were in good agreement with replicate determinations of total particulate mass by gravimetric filter collection. In contrast, average particle diameters determined for e-cigarettes by the electrical mobility method are in the 50 nm range and total particulate masses calculated based on the suggested diameters are orders of magnitude smaller than those determined gravimetrically. This latter discrepancy, and the very small particle diameters observed, are believed to result from almost complete e-cigarette aerosol particle evaporation at the dilution levels and conditions of the electrical mobility analysis. A much smaller degree, ~20% by mass, of apparent particle evaporation was observed for tobacco burning cigarette smoke. The spectral transmission method is validated in the current study against measurements on tobacco burning cigarette smoke, which has been well characterized in prior studies, and is supported as yielding an accurate characterization of the e-cigarette aerosol particle size distribution.

  2. Predicting effects of blood flow rate and size of vessels in a vasculature on hyperthermia treatments using computer simulation

    Directory of Open Access Journals (Sweden)

    Shih Tzu-Ching

    2010-03-01

    Full Text Available Abstract Background Pennes Bio Heat Transfer Equation (PBHTE has been widely used to approximate the overall temperature distribution in tissue using a perfusion parameter term in the equation during hyperthermia treatment. In the similar modeling, effective thermal conductivity (Keff model uses thermal conductivity as a parameter to predict temperatures. However the equations do not describe the thermal contribution of blood vessels. A countercurrent vascular network model which represents a more fundamental approach to modeling temperatures in tissue than do the generally used approximate equations such as the Pennes BHTE or effective thermal conductivity equations was presented in 1996. This type of model is capable of calculating the blood temperature in vessels and describing a vasculature in the tissue regions. Methods In this paper, a countercurrent blood vessel network (CBVN model for calculating tissue temperatures has been developed for studying hyperthermia cancer treatment. We use a systematic approach to reveal the impact of a vasculature of blood vessels against a single vessel which most studies have presented. A vasculature illustrates branching vessels at the periphery of the tumor volume. The general trends present in this vascular model are similar to those shown for physiological systems in Green and Whitmore. The 3-D temperature distributions are obtained by solving the conduction equation in the tissue and the convective energy equation with specified Nusselt number in the vessels. Results This paper investigates effects of size of blood vessels in the CBVN model on total absorbed power in the treated region and blood flow rates (or perfusion rate in the CBVN on temperature distributions during hyperthermia cancer treatment. Also, the same optimized power distribution during hyperthermia treatment is used to illustrate the differences between PBHTE and CBVN models. Keff (effective thermal conductivity model delivers the

  3. 46 CFR 69.11 - Determining the measurement system or systems for a particular vessel.

    Science.gov (United States)

    2010-10-01

    ... Measurement System, for applying the International Convention for the Safety of Life at Sea (SOLAS), the... system or systems for a particular vessel. (a) Convention Measurement System (subpart B). (1) Except as... construction before January 1, 1986, unless the owner requests measurement under the Convention Measurement...

  4. Image-guided optical measurement of blood oxygen saturation within capillary vessels (Conference Presentation)

    Science.gov (United States)

    Akons, Kfir; Zeidan, Adel; Yeheskely-Hayon, Daniella; Minai, Limor; Yelin, Dvir

    2016-03-01

    Values of blood oxygenation levels are useful for assessing heart and lung conditions, and are frequently monitored during routine patient care. Independent measurement of the oxygen saturation in capillary blood, which is significantly different from that of arterial blood, is important for diagnosing tissue hypoxia and for increasing the accuracy of existing techniques that measure arterial oxygen saturation. Here, we developed a simple, non-invasive technique for measuring the reflected spectra from individual capillary vessels within a human lip, allowing local measurement of the blood oxygen saturation. The optical setup includes a spatially incoherent broadband light that was focused onto a specific vessel below the lip surface. Backscattered light was imaged by a camera for identifying a target vessel and pointing the illumination beam to its cross section. Scattered light from the vessel was then collected by a single-mode fiber and analyzed by a fast spectrometer. Spectra acquired from small capillary vessels within a volunteer lip showed the characteristic oxyhemoglobin absorption bands in real time and with a high signal-to-noise ratio. Measuring capillary oxygen saturation using this technique would potentially be more accurate compared to existing pulse oximetry techniques due to its insensitivity to the patient's skin color, pulse rate, motion, and medical condition. It could be used as a standalone endoscopic technique for measuring tissue hypoxia or in conjunction with conventional pulse oximetry for a more accurate measurement of oxygen transport in the body.

  5. 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....

  6. Mini neutron monitor measurements at the Neumayer III station and on the German research vessel Polarstern

    Science.gov (United States)

    Heber, B.; Galsdorf, D.; Herbst, K.; Gieseler, J.; Labrenz, J.; Schwerdt, C.; Walter, M.; Benadé, G.; Fuchs, R.; Krüger, H.; Moraal, H.

    2015-08-01

    Neutron monitors (NMs) are ground-based devices to measure the variation of cosmic ray intensities, and although being reliable they have two disadvantages: their size as well as their weight. As consequence, [1] suggested the development of a portable, and thus much smaller and lighter, calibration neutron monitor that can be carried to any existing station around the world [see 2; 3]. But this mini neutron monitor, moreover, can also be installed as an autonomous station at any location that provides ’’office” conditions such as a) temperatures within the range of around 0 to less than 40 degree C as well as b) internet and c) power supply. However, the best location is when the material above the NM is minimized. In 2011 a mini Neutron Monitor was installed at the Neumayer III station in Antarctica as well as the German research vessel Polarstern, providing scientific data since January 2014 and October 2012, respectively. The Polarstern, which is in the possession of the Federal Republic of Germany represented by the Ministry of Education and Research and operated by the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research and managed by the shipping company Laeisz, was specially designed for working in the polar seas and is currently one of the most sophisticated polar research vessels worldwide. It spends almost 310 days a year at sea usually being located in the waters of Antarctica between November and March while spending the northern summer months in Arctic waters. Therefore, the vessel scans the rigidity range below the atmospheric threshold and above 10 GV twice a year. In contrast to spacecraft measurements NM data are influenced by variations of the geomagnetic field as well as the atmospheric conditions. Thus, in order to interpret the data a detailed knowledge of the instrument sensitivity with geomagnetic latitude (rigidity) and atmospheric pressure is essential. In order to determine the atmospheric response data from the

  7. Deterministic Predictions of Vessel Responses Based on Past Measurements

    DEFF Research Database (Denmark)

    Nielsen, Ulrik Dam; Jensen, Jørgen Juncher

    2017-01-01

    The paper deals with a prediction procedure from which global wave-induced responses can be deterministically predicted a short time, 10-50 s, ahead of current time. The procedure relies on the autocorrelation function and takes into account prior measurements only; i.e. knowledge about wave cond...

  8. Endoscopic digital holography for measuring flows in opaque vessels

    Science.gov (United States)

    Arévalo, Laura; Palero, Virginia; Lobera, Julia; Arroyo, M. Pilar

    2012-10-01

    In this work a new application of digital holography for the study of cardio vascular diseases is proposed. The simultaneous measurement of the blood flow velocity and the vein wall deformation can be obtained by combining digital holography and endoscopy. Endoscopes are used for the illumination and recording of digital holograms inside a vein model. Two different endoscopes have been used in different vein models in order to test the technique performance. Preliminary results of flow velocity and wall deformation are presented.

  9. Air method measurements of apple vessel length distributions with improved apparatus and theory

    Science.gov (United States)

    Shabtal Cohen; John Bennink; Mel Tyree

    2003-01-01

    Studies showing that rootstock dwarfing potential is related to plant hydraulic conductance led to the hypothesis that xylem properties are also related. Vessel length distribution and other properties of apple wood from a series of varieties were measured using the 'air method' in order to test this hypothesis. Apparatus was built to measure and monitor...

  10. Sonographic measurement of fetal thymus size in uncomplicated singleton pregnancies.

    Science.gov (United States)

    Tangshewinsirikul, Chayada; Panburana, Panyu

    2017-03-04

    To establish sonographic reference ranges of the normal fetal thymus size between 17 and 38 weeks of gestational age (GA). The study was conducted between April 1 and December 31, 2013. Low-risk singleton pregnancies without obstetrical and medical complications at the GAs between 17 and 38 weeks were recruited for thymus measurement. The fetal thymus was identified on transabdominal sonography at the three-vessel view. Maximal transverse diameter, perimeter, and thymus/thoracic ratio were measured. The best-fit models in predicting thymic dimensions as a function of GA and biparietal diameter (BPD) were determined using regression analysis, and percentile charts for predicting thymic dimensions were constructed. A total of 296 singleton pregnancies were recruited in this study. Maximal transverse diameter, perimeter, and thymus/thoracic ratio increased throughout pregnancy. The regression equation for maximal transverse diameter of the thymus as a function of GA was as follows: Predicted mean thymus diameter (mm) = -25.904 + 2.476 × GA - 0.019 × GA 2 (r = 0.915; p thymus diameter (mm) = 1.428 + 0.044 × GA (r = 0.017; p < 0.001). Sonographic reference ranges of the normal fetal thymic dimensions between 17 and 38 weeks of GA have been established. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound 45:150-159, 2017. © 2016 Wiley Periodicals, Inc.

  11. The Influence of Dome Size, Parent Vessel Angle, and Coil Packing Density on Coil Embolization Treatment in Cerebral Aneurysms

    Science.gov (United States)

    Frakes, David H.; Indahlastari, Aprinda; Ryan, Justin; Babiker, M. Haithem; Nair, Priya; Parthas, Varsha

    2013-11-01

    Intracranial aneurysms (ICAs) are dilated cerebral blood vessels. Treating ICAs effectively prior rupture is crucial since their association with 45% mortality rate. Embolic coiling is the most effective ICA treatment. Series of embolic coils are deployed into the aneurysm with the intent of reaching a sufficient packing density (PD) to help seal off the ICA from circulation. While coiling is effective, treatment failures have been associated with basilar tip aneurysms (BTAs), perhaps because of their geometry. The aim of this study was to examine the effect of dome size, parent vessel (PV) angle, and PD on intraaneurysmal (IA) velocity, crossneck (CN) flow and low wall shear stress (WSS) area using simulations and experiments in idealized BTA models. IA velocity and CN flow decreased after coiling, while low WSS area increased. With increasing PD, IA velocity and CN flow were further reduced, but low WSS area had a minimal change. Coil PD had the greatest impact on post-treatment flow while dome size had a greater impact than PV angle. Overall, the role of aneurysmal geometries may vary depending on treatment goal and timing e.g., high coil PD may reduce IA velocity more effectively during early aneurysmal growth when the dome size is small. Funded by the American Heart Association.

  12. Method for the quantitative measurement of collecting lymphatic vessel contraction in mice

    Directory of Open Access Journals (Sweden)

    Shan Liao

    2014-07-01

    Full Text Available Collecting lymphatic vessels are critical for the transport of lymph and its cellular contents to lymph nodes for both immune surveillance and the maintenance of tissue-fluid balance. Collecting lymphatic vessels drive lymph flow by autonomous contraction of smooth muscle cells that cover these vessels. Here we describe methods using intravital microscopy to image and quantify collecting lymphatic vessel contraction in mice. Our methods allow for the measurement of the strength of lymphatic contraction of an individual lymphangion in a mouse, which has not yet been demonstrated using other published methods. The ability to study murine collecting lymphatic vessel contraction—using the methods described here or other recently published techniques—allows the field to dissect the molecular mechanisms controlling lymphatic pumping under normal and pathological conditions using the wide variety of molecular tools and genetic models available in the mouse. We have used our methods to study lymphatic contraction in physiological and inflammatory conditions. The methods described here will facilitate the further study of lymphatic function in other pathological conditions that feature lymphatic complications.

  13. Measuring Economies of Size with Expense Ratios

    OpenAIRE

    Langemeier, Michael R.

    2013-01-01

    This paper examines the relationship between three expense ratios: total expense ratio; adjusted total expense ratio; and economic total expense ratio; and discusses economies of size for a sample of Kansas farms. The total expense ratio and the adjusted total expense ratios, though commonly used to examine financial efficiency, are not as good of indicators of economies of size as the economic total expense ratio which includes opportunity costs on unpaid operator and family labor, and farm ...

  14. A Study on Measurement of Internal Defects of Pressure Vessel by Digital Shearography(I)

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Young June; Park, Nak Kyu; Ryu, Won Jae [Chonbuk National University, Jeonju (Korea, Republic of); Kim, Kyung Suk [Chosun University, Gwangju (Korea, Republic of)

    2002-08-15

    Pipelines in power plants, nuclear facilities and chemical industries are often affected by corrosion effects. It is important to inspect the internal defects in pipelines in order to guarantee safe operational condition. We have taken relatively much time, cost and manpower to use conventional NDT methods because these methods are contact measuring methods. In this paper, we used digital shearography, a laser-based optical method which allows full-field measurement of surface displacement derivatives. This method has many advantages in practical use, such as low sensitivity to environmental noise, simple optical configuration and real time measurement. The experiment was performed with pressure vessels which has different internal cracks and detected internal cracks in the pressure vessels at a real time using phase shifting method

  15. Simultaneous assessment of vessel size index, relative blood volume, and vessel permeability in a mouse brain tumor model using a combined spin echo gradient echo echo-planar imaging sequence and viable tumor analysis.

    Science.gov (United States)

    Kording, Fabian; Weidensteiner, Claudia; Zwick, Stefan; Osterberg, Nadja; Weyerbrock, Astrid; Staszewski, Ori; von Elverfeldt, Dominik; Reichardt, Wilfried

    2014-12-01

    Combining multiple imaging biomarkers in one magnetic resonance imaging (MRI) session would be beneficial to gain more data pertaining to tumor vasculature under therapy. Therefore, simultaneous measurement of perfusion, permeability, and vessel size imaging (VSI) using a gradient echo spin echo (GE-SE) sequence with injection of a clinically approved gadolinium (Gd)-based contrast agent was assessed in an orthotopic glioma model. A combined spin echo gradient echo echo-planar imaging sequence was implemented using a single contrast agent Gd diethylenetriaminepentaacetic acid (Gd-DTPA). This sequence was tested in a mouse brain tumor model (U87_MG), also under treatment with an antiangiogenic agent (bevacizumab). T2 maps and the apparent diffusion coefficient (ADC) were used to differentiate regions of cell death and viable tumor tissue. In viable tumor tissue regional blood volume was 5.7 ± 0.6% in controls and 5.2 ± 0.3% in treated mice. Vessel size was 18.1 ± 2.4 μm in controls and 12.8 ± 2.0 μm in treated mice, which correlated with results from immunohistochemistry. Permeability (K(trans) ) was close to zero in treated viable tumor tissue and 0.062 ± 0.024 min(-1) in controls. Our MRI method allows simultaneous assessment of several physiological and morphological parameters and extraction of MRI biomarkers for vasculature. These could be used for treatment monitoring of novel therapeutic agents such as antiangiogenic drugs. © 2014 Wiley Periodicals, Inc.

  16. Measuring Cerebral Blood Flow in Moyamoya Angiopathy by Quantitative Magnetic Resonance Angiography Noninvasive Optimal Vessel Analysis.

    Science.gov (United States)

    Khan, Nadia; Lober, Robert M; Ostergren, Lauren; Petralia, Jacob; Bell-Stephens, Teresa; Navarro, Ramon; Feroze, Abdullah; Steinberg, Gary K

    2017-12-01

    Moyamoya disease causes progressive occlusion of the supraclinoidal internal carotid artery, and middle, anterior, and less frequently the posterior cerebral arteries, carrying the risk of stroke. Blood flow is often partially reconstituted by compensatory moyamoya collaterals and sometimes the posterior circulation. Cerebral revascularization can further augment blood flow. These changes to blood flow within the cerebral vessels, however, are not well characterized. To evaluate blood flow changes resulting from the disease process and revascularization surgery using quantitative magnetic resonance angiography with noninvasive optimal vessel analysis (NOVA). We retrospectively analyzed 190 preoperative and postoperative imaging scans in 66 moyamoya patients after revascularization surgery. Images were analyzed for blood flow using NOVA and compared with preoperative angiographic staging and postoperative blood flow. Blood flow rates within superficial temporal artery grafts were compared based on angiographic evidence of patency. Diseased vessels had lower blood flow, correlating with angiographic staging. Flow in posterior cererbal and basilar arteries increased with disease severity, particularly when both the anterior and middle cerebral arteries were occluded. Basilar artery flow and ipsilateral internal carotid artery flow decreased after surgery. Flow rates were different between angiographically robust and poor direct bypass grafts, as well as between robust and patent grafts. Preoperative changes in cerebral vessel flow as measured by NOVA correlated with angiographic disease progression. NOVA demonstrated that preoperative augmentation of the posterior circulation decreased after surgery. This report is the first to quantify the shift in collateral supply from the posterior circulation to the bypass graft.

  17. Measurement of flow velocity fields in small vessel-mimic phantoms and vessels of small animals using micro ultrasonic particle image velocimetry (micro-EPIV)

    Energy Technology Data Exchange (ETDEWEB)

    Qian Ming; Niu Lili; Jiang Bo; Jin Qiaofeng; Jiang Chunxiang; Zheng Hairong [Paul C. Lauterbur Research Center for Biomedical Imaging, Institute of Biomedical and Health Engineering, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen (China); Wang Yanping, E-mail: hr.zheng@siat.ac.c [Medical School of Jinan University, Guangzhou (China)

    2010-10-21

    Determining a multidimensional velocity field within microscale opaque fluid flows is needed in areas such as microfluidic devices, biofluid mechanics and hemodynamics research in animal studies. The ultrasonic particle image velocimetry (EchoPIV) technique is appropriate for measuring opaque flows by taking advantage of PIV and B-mode ultrasound contrast imaging. However, the use of clinical ultrasound systems for imaging flows in small structures or animals has limitations associated with spatial resolution. This paper reports on the development of a high-resolution EchoPIV technique (termed as micro-EPIV) and its application in measuring flows in small vessel-mimic phantoms and vessels of small animals. Phantom experiments demonstrate the validity of the technique, providing velocity estimates within 4.1% of the analytically derived values with regard to the flows in a small straight vessel-mimic phantom, and velocity estimates within 5.9% of the computationally simulated values with regard to the flows in a small stenotic vessel-mimic phantom. Animal studies concerning arterial and venous flows of living rats and rabbits show that the micro-EPIV-measured peak velocities within several cardiac cycles are about 25% below the values measured by the ultrasonic spectral Doppler technique. The micro-EPIV technique is able to effectively measure the flow fields within microscale opaque fluid flows.

  18. A study on quantitative measurement of internal defects of pressure vessel by digital shearography

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sung Tae; Kang, Young Jun; Jang, Jong Min [Chonbuk National University, Chonju (Korea, Republic of)

    1999-11-15

    Pipelines in power plants, nuclear facilities and chemical industries are often affected by corrosion effects. It is very important in detect such internal flaws of pipelines because they sometimes bring about serious problems. Conventional NDT methods have been taken relatively much time, money, and manpower because of performing as the method of contact with objects to be inspected. Digital shearography is a laser-based optical method which allows full-field observation of surface displacement derivatives. This method has many advantages in practical use, such as low sensitivity to environmental noise, simple optical configuration and real time measurement. In this paper, the experiment was performed with some pressure vessels which has different internal cracks. We measured internal crack length of the pressure vessels at a real time and compared with FEM simulation results.

  19. Assessment of the effect of vessel curvature on Doppler measurements in steady flow.

    Science.gov (United States)

    Balbis, S; Guiot, C; Roatta, S; Arina, R; Todros, T

    2004-05-01

    Blood vessel curvature is responsible for the appearance of nonaxial velocity components and for minor changes in the pattern of the axial flow. All the velocity components are expected to contribute to the Doppler signal produced by the ultrasound (US) backscattered by the insonated blood cells, the axial velocity, contributing to the actual volumetric blood flow, and the transverse velocity, causing the recirculating vortices. A detailed, separate analysis of the velocity components is, therefore, mandatory to quantify how vessel curvature can affect results and clinical diagnosis. Both experimental in vitro measures and numerical simulations were performed on a curved tube and the Doppler power spectra so obtained were compared. The satisfactorily agreement of the above spectra shows that the nonaxial velocity components are easily detectable with clinical equipment and that their amplitude, as expected, is not negligible and can bias Doppler measurements and resulting clinical diagnosis.

  20. Evaluation and accuracy of the local velocity data measurements in an agitated vessel

    Directory of Open Access Journals (Sweden)

    Kysela Bohuš

    2014-03-01

    Full Text Available Velocity measurements of the flow field in an agitated vessel are necessary for the improvement and better understanding of the mixing processes. The obtained results are used for the calculations of the impeller pumping capacity, comparison of the power consumption etc. We performed various measurements of the local velocities in an agitated vessel final results of which should be processed for several purposes so it was necessary to make an analysis of the obtained data suitability and their quality. Analysed velocity data were obtained from the LDA (Laser Doppler Anemometry and PIV (Particle Image Velocimetry measurements performed on a standard equipment where the flat bottomed vessel with four baffles was agitated by the six-blade Rushton turbine. The results from both used methods were compared. The frequency analyses were examined as well as the dependency of the data rates, time series lengths etc. The demands for the data processed in the form of the ensemble-averaged results were also established.

  1. In vivo measurement of hemodynamic information in stenosed rat blood vessels using X-ray PIV

    Science.gov (United States)

    Park, Hanwook; Park, Jun Hong; Lee, Sang Joon

    2016-11-01

    Measurements of the hemodynamic information of blood flows, especially wall shear stress (WSS), in animal models with circulatory vascular diseases (CVDs) are important to understand the pathological mechanism of CVDs. In this study, X-ray particle image velocimetry (PIV) with high spatial resolution was applied to obtain velocity field information in stenosed blood vessels with high WSS. 3D clips fabricated with a 3D printer were applied to the abdominal aorta of a rat cadaver to induce artificial stenosis in the real blood vessel of an animal model. The velocity and WSS information of blood flows in the stenosed vessel were obtained and compared at various stenosis severities. In vivo measurement was also conducted by fastening a stenotic clip on a live rat model through surgical intervention to reduce the flow rate to match the limited temporal resolution of the present X-ray PIV system. Further improvement of the temporal resolution of the system might be able to provide in vivo measurements of hemodynamic information from animal disease models under physiological conditions. The present results would be helpful for understanding the relation between hemodynamic characteristics and the pathological mechanism in animal CVD models.

  2. [Oxygen saturation of retinal vessels. Studies for measuring with polarized light].

    Science.gov (United States)

    Hammer, M; Schweitzer, D; Kolb, A; Thamm, E; Strobel, J

    1999-07-01

    The accuracy of the spectrometric measurement of the oxygen saturation in retinal vessels is limited by its signal-to-noise ratio. The aim of this study was to investigate the possibility of enhancement of the reflection signal by the use of polarized light. The Jena ophthalmospectrometer was equipped with two polarizing filters: one in the illumination and the other in front of the detector. Reflection spectra of erythrocytes streaming through a cuvette in the focus of an artificial eye were recorded. The influence of the polarization on the reflection spectra was investigated by rotating the polarizer in front of the detector. Furthermore, the degree of polarization of the light reflected from retinal vessels in vivo was determined. The degree of polarization of the light reflected from the erythrocytes was 0.6-0.8, whereas the polarization of light reflected by a standard white reflectance target was virtually zero. Polarized light can be used for the reduction of error in retinal vessel oximetry.

  3. Right and left correlation of retinal vessel caliber measurements in anisometropic children: effect of refractive error.

    Science.gov (United States)

    Joachim, Nichole; Rochtchina, Elena; Tan, Ava Grace; Hong, Thomas; Mitchell, Paul; Wang, Jie Jin

    2012-08-07

    Previous studies have reported high right-left eye correlation in retinal vessel caliber. We test the hypothesis that right-left correlation in retinal vessel caliber would be reduced in anisometropic compared with emmetropic children. Retinal arteriolar and venular calibers were measured in 12-year-old children. Three groups were selected: group 1, both eyes emmetropic (n = 214); group 2, right-left spherical equivalent refraction (SER) difference ≥1.00 but right-left SER difference ≥2.00 D (n = 32). Pearson's correlations between the two eyes were compared between group 1 and group 2 or 3. Associations between right-left difference in refractive error and right-left difference in caliber measurements were assessed using linear regression models. Right-left correlation in group 1 was 0.57 for central retinal arteriolar equivalent (CRAE) and 0.70 for central retinal venular equivalent (CRVE) compared with 0.60 and 0.82 for CRAE and CRVE, respectively, in group 2 (P = 0.42 and P = 0.08), and 0.36 and 0.52, respectively, in group 3 (P = 0.08 and P = 0.07, referenced to group 1). Each 1.00-D increase in right-left SER difference was associated with a 0.74-μm increase in mean CRAE difference (P = 0.02) and a 1.23-μm increase in mean CRVE difference between the two eyes (P = 0.002). Each 0.1-mm increase in right-left difference in axial length was associated with a 0.21-μm increase in the mean difference in CRAE (P = 0.01) and a 0.42-μm increase in the mean difference in CRVE (P < 0.0001) between the two eyes. Refractive error ≥2.00 D may contribute to variation in measurements of retinal vessel caliber.

  4. Use of Movable Beam Position Monitors for Beam Size Measurements

    CERN Document Server

    Assmann, R W; Matheson, J

    2000-01-01

    The use of beam position monitors (BPMs) as non-intercepting emittance monitors has been proposed in 1983 by Miller et al. The emittance measurement relies on the beam size dependency of the BPM signals. It is shown that the original proposal can be improved by using movable BPMs. Changing the BPM position with a stepping motor allows accurately calibrating the beam size measurement. The absolute scale on the beam size measurement is given by the scale of the stepping motor and can be determined in the laboratory and measured in situ. Uncontrolled changes of the beam position can be monitored through the use of a BPM triplet.

  5. A Study on Measurement of Internal Defects of Pressure Vessel by Digital Shearography(II)

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Young June; Park, Nak Kyu; Ryu, Won Jae; Kim, Dong Woo [Chonbuk National University, Jeonju (Korea, Republic of)

    2002-08-15

    Recently the necessity of study on optical measuring method using laser to detect the pipeline's defect in nuclear facilities, chemical industries and power plants has been increased. Because laser light can be delivered to a remote area without any difficulties, the application of laser in many industries can solve several difficulties from the limitation of access in danger area and reduce the risks of workers. Therefore, we applied a new experimental technique to the measurement of internal defects in pressure vessels with the combination of shearography and image processing technique and detected the internal cracks of pressure vessels in the former paper. In this paper, we used the same optical system as in the former study and found the optimum shearing magnitude by comparing the real length of specimen with experimental results. A variety of conditions were applied to certify the validity of this method. Actually, several specimens which have different lengths and depths were used in this experiment under the three diverse pressure. Consequently, we have carried out this experiment to determine the limit of measurement ability with analyzing errors

  6. The heritability of vessel size of the pampiniform plexus as a means to assess the genetic component of varicocele

    Science.gov (United States)

    Ultrasonography of each testicle was used to capture a coronal-saggital image of the veins of the pampiniform plexus (PP) and the testicular artery of 239 boars at approximately 6 months of age. Three to 10 vessels of the PP were used to derive the average area of right PP vessels (AAR) and the aver...

  7. Recent activity of international comparison for nanoparticle size measurement

    Science.gov (United States)

    Takahashi, Kayori; Takahata, Keiji; Misumi, Ichiko; Sugawara, Kentaro; Gonda, Satoshi; Ehara, Kensei

    2014-08-01

    Nanoparticle sizing is the most fundamental measurement for producing nanomaterials, evaluation of nanostructure, and the risk assessment of nanomaterials for human health. Dynamic light scattering (DLS) is widely used as a useful and convenient technique for determining nanoparticle size in liquid; however, the precision of this technique has been unclear. Some international comparisons are now in progress to verify the measurement accuracy of nanoparticle sizing, as a typical example of Asia Pacific Metrology Programme Supplementary Comparison. In this study, we evaluated the precision of DLS technique for nanoparticle sizing and estimated the uncertainty of the DLS data for polystyrene latex suspensions. The extrapolations of apparent diffusion coefficients to infinite dilution and to lower angles yielded more precise values than those obtained at one angle and one concentration. The extrapolated particle size measured by DLS was compared to the size determined by differential mobility analyzer (DMA), atomic force microscopy (AFM), and scanning electron microscopy (SEM). Before the comparison, the intensity-averaged size measured by DLS was recalculated to the number-averaged size, and the thickness of water layer attaching on the surface of particles were added into uncertainty of particle sizing by DLS. After the recalculation, the consistent values of mean particle diameter were obtained between those by DLS and by DMA, AFM, and SEM within the estimated uncertainties.

  8. Detection and measurement of retinal vessels in fundus images using amplitude modified second-order Gaussian filter.

    Science.gov (United States)

    Gang, Luo; Chutatape, Opas; Krishnan, Shankar M

    2002-02-01

    In this paper, the fitness of estimating vessel profiles with Gaussian function is evaluated and an amplitude-modified second-order Gaussian filter is proposed for the detection and measurement of vessels. Mathematical analysis is given and supported by a simulation and experiments to demonstrate that the vessel width can be measured in linear relationship with the "spreading factor" of the matched filter when the magnitude coefficient of the filter is suitably assigned. The absolute value of vessel diameter can be determined simply by using a precalibrated line, which is typically required since images are always system dependent. The experiment shows that the inclusion of the width measurement in the detection process can improve the performance of matched filter and result in a significant increase in success rate of detection.

  9. Simultaneous shape and deformation measurements in a blood vessel model by two wavelength interferometry

    Science.gov (United States)

    Andrés, Nieves; Pinto, Cristina; Lobera, Julia; Palero, Virginia; Arroyo, M. Pilar

    2017-06-01

    Holographic techniques have been used to measure the shape and the radial deformation of a blood vessel model and a real sheep aorta. Measurements are obtained from several holograms recorded for different object states. For each object state, two holograms with two different wavelengths are multiplexed in the same digital recording. Thus both holograms are simultaneously recorded but the information from each of them is separately obtained. The shape analysis gives a wrapped phase map whose fringes are related to a synthetic wavelength. After a filtering and unwrapping process, the 3D shape can be obtained. The shape data for each line are fitted to a circumference in order to determine the local vessel radius and center. The deformation analysis also results in a wrapped phase map, but the fringes are related to the laser wavelength used in the corresponding hologram. After the filtering and unwrapping process, a 2D map of the deformation in an out-of-plane direction is reconstructed. The radial deformation is then calculated by using the shape information.

  10. Conservative Sample Size Determination for Repeated Measures Analysis of Covariance

    OpenAIRE

    Timothy M Morgan; Case, L. Douglas

    2013-01-01

    In the design of a randomized clinical trial with one pre and multiple post randomized assessments of the outcome variable, one needs to account for the repeated measures in determining the appropriate sample size. Unfortunately, one seldom has a good estimate of the variance of the outcome measure, let alone the correlations among the measurements over time.

  11. Fluid Vessel Quantity using Non-Invasive PZT Technology Flight Volume Measurements Under Zero G Analysis

    Science.gov (United States)

    Garofalo, Anthony A.

    2013-01-01

    The purpose of the project is to perform analysis of data using the Systems Engineering Educational Discovery (SEED) program data from 2011 and 2012 Fluid Vessel Quantity using Non-Invasive PZT Technology flight volume measurements under Zero G conditions (parabolic Plane flight data). Also experimental planning and lab work for future sub-orbital experiments to use the NASA PZT technology for fluid volume measurement. Along with conducting data analysis of flight data, I also did a variety of other tasks. I provided the lab with detailed technical drawings, experimented with 3d printers, made changes to the liquid nitrogen skid schematics, and learned how to weld. I also programmed microcontrollers to interact with various sensors and helped with other things going on around the lab.

  12. Aerosol size measurement during the 2004/2005 harmattan season ...

    African Journals Online (AJOL)

    The aerosol size measurement at Uturu (lat.05.33°N, 06.03°N and long. 07.10"E, 07.29°E) Nigeria during the 2004/2005 harmattan season was carried out. The aerosol size distributions were measured using zeiss micrometer inserted on the diaphragm inside the eye piece of Olympus binocular microscope. The dust ...

  13. Conservative Sample Size Determination for Repeated Measures Analysis of Covariance.

    Science.gov (United States)

    Morgan, Timothy M; Case, L Douglas

    2013-07-05

    In the design of a randomized clinical trial with one pre and multiple post randomized assessments of the outcome variable, one needs to account for the repeated measures in determining the appropriate sample size. Unfortunately, one seldom has a good estimate of the variance of the outcome measure, let alone the correlations among the measurements over time. We show how sample sizes can be calculated by making conservative assumptions regarding the correlations for a variety of covariance structures. The most conservative choice for the correlation depends on the covariance structure and the number of repeated measures. In the absence of good estimates of the correlations, the sample size is often based on a two-sample t-test, making the 'ultra' conservative and unrealistic assumption that there are zero correlations between the baseline and follow-up measures while at the same time assuming there are perfect correlations between the follow-up measures. Compared to the case of taking a single measurement, substantial savings in sample size can be realized by accounting for the repeated measures, even with very conservative assumptions regarding the parameters of the assumed correlation matrix. Assuming compound symmetry, the sample size from the two-sample t-test calculation can be reduced at least 44%, 56%, and 61% for repeated measures analysis of covariance by taking 2, 3, and 4 follow-up measures, respectively. The results offer a rational basis for determining a fairly conservative, yet efficient, sample size for clinical trials with repeated measures and a baseline value.

  14. Measurement of large-size casting geometry of the CMM

    Directory of Open Access Journals (Sweden)

    B. Gapiński

    2011-04-01

    Full Text Available The aim of this paper is to present the geometric dimensions’ control of large castings and moulds on coordinate measuring machines(CMMs. Precise measurements of large components are connected with many problems that arise from the vast mass and dimensions ofthe element. The bodies with a mass of several or even tens of tons require that the same metrological regime is restricted which isdedicated for small components measurement. That force the use of suitable measuring device, measurement conditions and the adequatepreparation of the element. Quality requirements expressed as tolerances in absolute terms do not cause difficulties in measurement. With regard to the significant size of the workpiece, it is not as easy to measure dimensions as with control of small elements. The paper presents the Coordinate Measuring Machines used to control large-size items.

  15. Image processing applied to measurement of particle size

    Science.gov (United States)

    Vega, Fabio; Lasso, Willian; Torres, Cesar

    2015-01-01

    Five different types of aggregates have been analyzed, and the size of particles on samples immersed in distilled water as silicon dioxide, titanium dioxide, styrenes and crushed silica particles is made; an attempt at applying the digital image processing (DIP) technique to analyze the particle size, we developed a system of measures microparticles using a microscope, a CCD camera and acquisition software and video processing developed in MATLAB. These studies are combined with laser light using measurements by diffractometry and obtain calibration in the system implemented, in this work we achievement measurement particle size on the order of 4 to 6 micrometers. The study demonstrates that DIP is a fast, convenient, versatile, and accurate technique for particle size analysis; the limitations of implemented setup too will be discussed.

  16. Size distribution measurements and chemical analysis of aerosol components

    Energy Technology Data Exchange (ETDEWEB)

    Pakkanen, T.A.

    1995-12-31

    The principal aims of this work were to improve the existing methods for size distribution measurements and to draw conclusions about atmospheric and in-stack aerosol chemistry and physics by utilizing size distributions of various aerosol components measured. A sample dissolution with dilute nitric acid in an ultrasonic bath and subsequent graphite furnace atomic absorption spectrometric analysis was found to result in low blank values and good recoveries for several elements in atmospheric fine particle size fractions below 2 {mu}m of equivalent aerodynamic particle diameter (EAD). Furthermore, it turned out that a substantial amount of analyses associated with insoluble material could be recovered since suspensions were formed. The size distribution measurements of in-stack combustion aerosols indicated two modal size distributions for most components measured. The existence of the fine particle mode suggests that a substantial fraction of such elements with two modal size distributions may vaporize and nucleate during the combustion process. In southern Norway, size distributions of atmospheric aerosol components usually exhibited one or two fine particle modes and one or two coarse particle modes. Atmospheric relative humidity values higher than 80% resulted in significant increase of the mass median diameters of the droplet mode. Important local and/or regional sources of As, Br, I, K, Mn, Pb, Sb, Si and Zn were found to exist in southern Norway. The existence of these sources was reflected in the corresponding size distributions determined, and was utilized in the development of a source identification method based on size distribution data. On the Finnish south coast, atmospheric coarse particle nitrate was found to be formed mostly through an atmospheric reaction of nitric acid with existing coarse particle sea salt but reactions and/or adsorption of nitric acid with soil derived particles also occurred. Chloride was depleted when acidic species reacted

  17. Causality in Statistical Power: Isomorphic Properties of Measurement, Research Design, Effect Size, and Sample Size

    Directory of Open Access Journals (Sweden)

    R. Eric Heidel

    2016-01-01

    Full Text Available Statistical power is the ability to detect a significant effect, given that the effect actually exists in a population. Like most statistical concepts, statistical power tends to induce cognitive dissonance in hepatology researchers. However, planning for statistical power by an a priori sample size calculation is of paramount importance when designing a research study. There are five specific empirical components that make up an a priori sample size calculation: the scale of measurement of the outcome, the research design, the magnitude of the effect size, the variance of the effect size, and the sample size. A framework grounded in the phenomenon of isomorphism, or interdependencies amongst different constructs with similar forms, will be presented to understand the isomorphic effects of decisions made on each of the five aforementioned components of statistical power.

  18. Characterization of silver nanoparticles-alginate complexes by combined size separation and size measurement techniques.

    Science.gov (United States)

    António, Diana C; Cascio, Claudia; Gilliland, Douglas; Nogueira, António J A; Rossi, François; Calzolai, Luigi

    2016-12-16

    The detection and quantification of nanoparticles is a complex issue due to the need to combine "classical" identification and quantification of the constituent material, with the accurate determination of the size of submicrometer objects, usually well below the optical diffraction limit. In this work, the authors show that one of the most used analytical methods for silver nanoparticles, asymmetric flow field-flow fractionation, can be strongly influenced by the presence of dissolved organic matter (such as alginate) and lead to potentially misleading results. The authors explain the anomalies in the separation process and show a very general way forward based on the combination of size separation and size measurement techniques. This combination of techniques results in more robust AF4-based methods for the sizing of silver nanoparticles in environmental conditions and could be generally applied to the sizing of nanoparticles in complex matrices.

  19. CONTACTLESS MEASUREMENT OF KEY PARAMETERS OF LIMB VESSELS ON AN OCCLUSAL PLETHYSMOGRAPHY METHOD

    Directory of Open Access Journals (Sweden)

    V. I. Kuznetsov

    2013-01-01

    Full Text Available The purpose of this publication – to familiarize the readers with the newest achievements in the field of vision   machine   technologies   with   regard to the   occlusal   plethysmography.   The   principle   of plethysmograph work is similar to a principle of mechanical occlusal plethysmograph work, with that only a difference that working measuring environment (gas or liquid is replaced with laser labels, and fixation of change of volume is made by machine vision with the subsequent computer processing. Application of laser technologies of machine vision in future considerably simplified process of diagnostics, will allow to carry out diagnostics repeatedly and under various conditions of, for example, case of external action on the examined finiteness of the of heat, cold, physical exercise, and so, is representative of more and accurate picture of the state of blood vessels in the dynamics.

  20. Electrostatic Method to Measure the Size of the Sprayed Droplets

    Directory of Open Access Journals (Sweden)

    Kuna-Broniowski, M.

    2015-11-01

    Full Text Available In the paper is presented the new method the measurement of the main parameters the atomised stream of liquid. This method base on the measurement of the electric charge carried by water drops charged by high voltage. The electrostatic sensor to measure of the droplets size, is associated with precision mechanic system scanning the sprayed surface. The amplified and conditioned signals from electrostatic sensor are send to the computer system equipped in virtual instrument to analyse the size and spatial distribution of droplets. The virtual instrument control also the scanning system.

  1. Measurements of near-bottom stress and turbidity in the Gulf of Trieste during the passage of vessels

    Science.gov (United States)

    Malacic, Vlado

    2017-04-01

    The Gulf of Trieste (GT) is a semi-enclosed 20 x 20 km gulf in the northernmost part of the Adriatic Sea with depths that reach 24 m at the most. Sediments in the southern (Slovenian) side of GT inside the shallow Bay of Koper, where measurements of near-bottom stress took place, are composed primarily of clayey silt (2-63 um). The observation of currents and turbidity took place inside the Bay of Koper at a location inside the shipping route, where the bottom depth is around 19 m. The goal of measurements was to study the bottom erosion due to changes to flow fields by ship movements (and due to propeller wakes). High-frequency measurements of currents and turbulence near the sea bottom were conducted with two Vector instruments (Nortek AS) with pressure sensors in the interval 123-31 July 2013, mounted at heights 0.2 m and 1.3 m above the sea bottom. Turbidity was measured with the same frequency with Seapoint IR (880 nm) turbidimeters placed at the same heights. In addition, turbidity was measured also with the 'old' Minitracka II instrument of Chelsea Instruments that functioned at 470 nm. 10 s averages of 1 s measurements were recorded. When the voltage output of this instrument surpassed the chosen threshold value (e.g. 2 V out of 5 V range) the triggering signal was sent to start measurements of the size distribution of suspended sediments and their falling speeds with the laser in-situ scattering and transmissometery (LISST-STX). In the interval 7-19 November 2013 currents over the whole water column with vertical resolution of 0.5 m have been also surveyed with the 1 MHz ADCP instrument (Nortek AS) with a sampling frequency of 1/s, where 10 s averages were recorded. It appears that pure ship's dislocation of a mass of fluid, which may easily surpass 105 tons, is important in the erosion of the bottom. We have confirmed this by velocity and stress peaks near the sea-floor in the Bay of Koper that were frequently accompanied by peaks of turbidity during

  2. Accuracy and initial clinical experience with measurement software (advanced vessel analysis) in three-dimensional imaging

    Energy Technology Data Exchange (ETDEWEB)

    Abe, Toshi; Hirohata, Masaru [Kurume Univ., Fukuoka (Japan). School of Medicine; Tanigawa, Hitoshi [Kurume Univ., Fukuoka (Japan). Hospital] [and others

    2002-12-01

    Recently, the clinical benefits of three dimensional (3D) imaging, such as 3D-CTA and 3D-DSA, in cerebro-vascular disease have been widely recognized. Software for quantitative analysis of vascular structure in 3D imaging (advanced vessel analysis: AVA) has been developed. We evaluated AVA with both phantom studies and a few clinical cases. In spiral and curvy aluminum tube phantom studies, the accuracy of diameter measurements was good in 3D images produced from data set generated by multi-detector row CT or rotational angiography. The measurement error was less than 0.03 mm on aluminum tube phantoms that were 3 mm and 5 mm in diameter. In the clinical studies, the differences of carotid artery diameter measurements between 2D-DSA and 3D-DSA was less than 0.3 mm in. The measurement of length, diameter and angle by AVA should provide useful information for planning surgical and endovascular treatments of cerebro-vascular disease. (author)

  3. Accuracy of the photogrametric measuring system for large size elements

    Directory of Open Access Journals (Sweden)

    M. Grzelka

    2011-04-01

    Full Text Available The aim of this paper is to present methods of estimating and guidelines for verifying the accuracy of optical photogrammetric measuringsystems, using for measurement of large size elements. Measuring systems applied to measure workpieces of a large size which oftenreach more than 10000mm require use of appropriate standards. Those standards provided by the manufacturer of photogrammetricsystems are certified and are inspected annually. To make sure that these systems work properly there was developed a special standardVDI / VDE 2634, "Optical 3D measuring systems. Imaging systems with point - by - point probing. " According to recommendationsdescribed in this standard research on accuracy of photogrametric measuring system was conducted using K class gauge blocks dedicatedto calibrate and test accuracy of classic CMMs. The paper presents results of research of estimation the actual error of indication for sizemeasurement MPEE for photogrammetric coordinate measuring system TRITOP.

  4. Measurements of Protein-Protein Interactions by Size Exclusion Chromatography

    OpenAIRE

    Bloustine, J.; Berejnov, V.; Fraden, S.

    2003-01-01

    A method is presented for determining second virial coefficients (B2) of protein solutions from retention time measurements in size exclusion chromatography. We determine B2 by analyzing the concentration dependence of the chromatographic partition coefficient. We show the ability of this method to track the evolution of B2 from positive to negative values in lysozyme and bovine serum albumin solutions. Our size exclusion chromatography results agree quantitatively with data obtained by light...

  5. Measurement of inner defects and out of plane deformation of pressure vessel in piping of circulation system using shearography

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Chan Geun; Kim, Hyun Ho; Jung, Hyun Il; Choi, Tae Ho; Jung, Hyun Chul; Kim, Kyeog Suk [Chosun University, Gwangju (Korea, Republic of)

    2014-10-15

    Wall thinning defects can occur in the pressure vessels used in a variety of industries. Such defects are related to the flow velocity. Considering the fact that such vessels constitute up to 70 or 80% of the plant structures in a power plant, it is important to measure internal defects as part of a safety evaluation. In this study, optical measurement were applied in a non-destructive evaluation using shearography to ensure the safety and improve the reliability of a power plant through the non-contact, non-destructive evaluation of pressure vessels. In order to verify whether the pressure vessels contained faults, experimental and analytical investigation were conducted to measure any internal defects and out-of-plane deformation from inner temperature changes and pressure changes in the piping of the circulation system. The most important factors in this research were the thickness, width, and length of a defect. An increase in these could confirm an increase in the deformation. Thus, internal defects in a pressure vessel were measured using shearography, which made it possible to ensure the reliability and integrity of the pipe.

  6. Limitations of quantitative photoacoustic measurements of blood oxygenation in small vessels

    Energy Technology Data Exchange (ETDEWEB)

    Sivaramakrishnan, Mathangi [Optical Imaging Laboratory, Department of Biomedical Engineering, Texas A and M University 3120 TAMU, College Station, TX 77843-3120 (United States); Maslov, Konstantin [Optical Imaging Laboratory, Department of Biomedical Engineering, Texas A and M University 3120 TAMU, College Station, TX 77843-3120 (United States); Zhang, Hao F [Optical Imaging Laboratory, Department of Biomedical Engineering, Texas A and M University 3120 TAMU, College Station, TX 77843-3120 (United States); Stoica, George [Department of Pathobiology, Texas A and M University, College Station, TX 77843-5547 (United States); Wang, Lihong V [Optical Imaging Laboratory, Department of Biomedical Engineering, Texas A and M University 3120 TAMU, College Station, TX 77843-3120 (United States)

    2007-03-07

    We investigate the feasibility of obtaining accurate quantitative information, such as local blood oxygenation level (sO{sub 2}), with a spatial resolution of about 50 {mu}m from spectral photoacoustic (PA) measurements. The optical wavelength dependence of the peak values of the PA signals is utilized to obtain the local blood oxygenation level. In our in vitro experimental models, the PA signal amplitude is found to be linearly proportional to the blood optical absorption coefficient when using ultrasonic transducers with central frequencies high enough such that the ultrasonic wavelengths are shorter than the light penetration depth into the blood vessels. For an optical wavelength in the 578-596 nm region, with a transducer central frequency that is above 25 MHz, the sensitivity and accuracy of sO{sub 2} inversion is shown to be better than 4%. The effect of the transducer focal position on the accuracy of quantifying blood oxygenation is found to be negligible. In vivo oxygenation measurements of rat skin microvasculature yield results consistent with those from in vitro studies, although factors specific to in vivo measurements, such as the spectral dependence of tissue optical attenuation, dramatically affect the accuracy of sO{sub 2} quantification in vivo.

  7. Laser triangulation method for measuring the size of parking claw

    Science.gov (United States)

    Liu, Bo; Zhang, Ming; Pang, Ying

    2017-10-01

    With the development of science and technology and the maturity of measurement technology, the 3D profile measurement technology has been developed rapidly. Three dimensional measurement technology is widely used in mold manufacturing, industrial inspection, automatic processing and manufacturing, etc. There are many kinds of situations in scientific research and industrial production. It is necessary to transform the original mechanical parts into the 3D data model on the computer quickly and accurately. At present, many methods have been developed to measure the contour size, laser triangulation is one of the most widely used methods.

  8. A polygon laser scanning micrometer for magnet size measurement studies

    Science.gov (United States)

    Khullar, R.; Mishra, G.; Sharma, G.; Prakash, B.; Gehlot, M.; Huse, V.; Mishra, S.

    2014-05-01

    In this paper, we describe the design and development of a polygon laser scanner for undulator magnet size measurement studies. In the laser scan micrometer, a laser light source is focused on to the facets of a rotating polygon mirror that reflects the laser beam. The parallel light emerging from the polygon surface falls on the object through a F-theta lens. The object obstructs the light. A lens at the opposite side of the object collects and focuses the light onto a detector. The shadow caused by the obstruction results in an output voltage for a period of time that is proportional to the size of the object. The method is used for undulator magnet size measurements for free electron laser applications.

  9. Measuring firm size distribution with semi-nonparametric densities

    Science.gov (United States)

    Cortés, Lina M.; Mora-Valencia, Andrés; Perote, Javier

    2017-11-01

    In this article, we propose a new methodology based on a (log) semi-nonparametric (log-SNP) distribution that nests the lognormal and enables better fits in the upper tail of the distribution through the introduction of new parameters. We test the performance of the lognormal and log-SNP distributions capturing firm size, measured through a sample of US firms in 2004-2015. Taking different levels of aggregation by type of economic activity, our study shows that the log-SNP provides a better fit of the firm size distribution. We also formally introduce the multivariate log-SNP distribution, which encompasses the multivariate lognormal, to analyze the estimation of the joint distribution of the value of the firm's assets and sales. The results suggest that sales are a better firm size measure, as indicated by other studies in the literature.

  10. Measurement of Heat Transfer Coefficients in an Agitated Vessel with Tube Baffles

    Directory of Open Access Journals (Sweden)

    M. Dostál

    2010-01-01

    Full Text Available Cooling or heating an agitated liquid is a very common operation in many industrial processes. A classic approach is to transfer the necessary heat through the vessel jacket. Another option, frequently used in the chemical and biochemical industries is to use the heat transfer area of vertical tube baffles. In large equipment, e.g. fermentor, the jacket surface is often not sufficient for large heat transfer requirements and tube baffles can help in such cases. It is then important to know the values of the heat transfer coefficients between the baffles and the agitated liquid. This paper presents the results of heat transfer measurements using the transient method when the agitated liquid is periodically heated and cooled by hot and cold water running through tube baffles. Solving the unsteady enthalpy balance, it is possible to determine the heat transfer coefficient. Our results are summarized by the Nusselt number correlations, which describe the dependency on the Reynolds number, and they are compared with other measurements obtained by a steady-state method.

  11. Measuring Spray Droplet Size from Agricultural Nozzles Using Laser Diffraction.

    Science.gov (United States)

    Fritz, Bradley K; Hoffmann, W Clint

    2016-09-16

    When making an application of any crop protection material such as an herbicide or pesticide, the applicator uses a variety of skills and information to make an application so that the material reaches the target site (i.e., plant). Information critical in this process is the droplet size that a particular spray nozzle, spray pressure, and spray solution combination generates, as droplet size greatly influences product efficacy and how the spray moves through the environment. Researchers and product manufacturers commonly use laser diffraction equipment to measure the spray droplet size in laboratory wind tunnels. The work presented here describes methods used in making spray droplet size measurements with laser diffraction equipment for both ground and aerial application scenarios that can be used to ensure inter- and intra-laboratory precision while minimizing sampling bias associated with laser diffraction systems. Maintaining critical measurement distances and concurrent airflow throughout the testing process is key to this precision. Real time data quality analysis is also critical to preventing excess variation in the data or extraneous inclusion of erroneous data. Some limitations of this method include atypical spray nozzles, spray solutions or application conditions that result in spray streams that do not fully atomize within the measurement distances discussed. Successful adaption of this method can provide a highly efficient method for evaluation of the performance of agrochemical spray application nozzles under a variety of operational settings. Also discussed are potential experimental design considerations that can be included to enhance functionality of the data collected.

  12. An overview of aerosol particle sensors for size distribution measurement

    Directory of Open Access Journals (Sweden)

    Panich Intra

    2007-08-01

    Full Text Available Fine aerosols are generally referred to airborne particles of diameter in submicron or nanometer size range. Measurement capabilities are required to gain understanding of these particle dynamics. One of the most important physical and chemical parameters is the particle size distribution. The aim of this article is to give an overview of recent development of already existing sensors for particle size distribution measurement based on electrical mobility determination. Available instruments for particle size measurement include a scanning mobility particle sizer (SMPS, an electrical aerosol spectrometer (EAS, an engine exhaust particle sizer (EEPS, a bipolar charge aerosol classifier (BCAC, a fast aerosol spectrometer (FAS a differential mobility spectrometer (DMS, and a CMU electrical mobility spectrometer (EMS. The operating principles, as well as detailed physical characteristics of these instruments and their main components consisting of a particle charger, a mobility classifier, and a signal detector, are described. Typical measurements of aerosol from various sources by these instruments compared with an electrical low pressure impactor (ELPI are also presented.

  13. New angiographic measurement tool for analysis of small cerebral vessels: application to a subarachnoid haemorrhage model in the rat

    Energy Technology Data Exchange (ETDEWEB)

    Turowski, B.; Moedder, U. [Heinrich-Heine University, Institute of Diagnostic Radiology, Neuroradiology, Duesselorf (Germany); Haenggi, D.; Steiger, H.J. [Heinrich-Heine University, Department of Neurosurgery, Duesseldorf (Germany); Beck, A.; Aurich, V. [Heinrich-Heine University, Institute of Informatics, Duesseldorf (Germany)

    2007-02-15

    Exact quantification of vasospasm by angiography is known to be difficult especially in small vessels. The purpose of the study was to develop a new method for computerized analysis of small arteries and to demonstrate feasibility on cerebral angiographies of rats acquired on a clinical angiography unit. A new software tool analysing grey values and subtracting background noise was validated on a vessel model. It was tested in practice in animals with subarachnoid haemorrhage (SAH). A total of 28 rats were divided into four groups: SAH untreated, SAH treated with local calcium antagonist, SAH treated with placebo, and sham-operated. The diameters of segments of the internal carotid, caudal cerebral, middle cerebral, rostral cerebral and the stapedial arteries were measured and compared to direct measurements of the diameters on magnified images. There was a direct correlation between the cross-sectional area of vessels measured in a phantom and the measurements acquired using the new image analysis method. The spread of repeated measurements with the new software was small compared to the spread of direct measurements of vessel diameters on magnified images. Application of the measurement tool to experimental SAH in rats showed a statistically significant reduction of vasospasm in the SAH groups treated with nimodipine-releasing pellets in comparison to all the other groups combined. The presented computerized method for analysis of small intracranial vessels is a new method allowing precise relative measurements. Nimodipine-releasing subarachnoidal pellets reduce vasospasm, but further testing with larger numbers is necessary. The tool can be applied to human angiography without modification and offers the promise of substantial progress in the diagnosis of vasospasm after SAH. (orig.)

  14. Turbulence characterization of a high-pressure high-temperature fan-stirred combustion vessel using LDV, PIV and TR-PIV measurements

    Science.gov (United States)

    Galmiche, Bénédicte; Mazellier, Nicolas; Halter, Fabien; Foucher, Fabrice

    2014-01-01

    Standard particle imaging velocimetry (PIV), time-resolved particle imaging velocimetry (TR-PIV) and laser Doppler velocimetry (LDV) are complementary techniques used to measure the turbulence statistics in a fan-stirred combustion vessel. Since a solid knowledge of the aerodynamic characteristics of the turbulent flow will enable better analysis of the flame-turbulence interactions, the objective of this paper is to provide an accurate characterization of the turbulent flow inside the combustion vessel. This paper aims at becoming a reference for further work on turbulent premixed flames using this fan-stirred combustion vessel. Close approximations of homogeneous and isotropic turbulence are achieved using this setup. The integral length scales L, Taylor microscales λ and Kolmogorov length scales η, the rms velocity fluctuations and the energy spectra are investigated using PIV, TR-PIV and LDV techniques. The difficulty to reach an accurate estimation of the integral length scale is particularly examined. The strengths and limitations of these three techniques are highlighted. High temporally resolved and high spatially resolved PIV appears as an interesting alternative to LDV in so far as close attention is paid to the measurements resolution. Indeed, the largest scales of the flow are limited by the field size and the smallest ones may be not caught with high accuracy due to the limited spatial resolution. A low spatial resolution of the PIV measurements can also lead to an underestimation of the rms velocity fluctuations. As the vessel was designed to study turbulent combustion at high initial pressure and high initial temperature, the effects of the gas temperature and pressure on the energy spectra and the turbulent parameters are finally investigated in the last part of the paper.

  15. Method for measuring the size distribution of airborne rhinovirus

    Energy Technology Data Exchange (ETDEWEB)

    Russell, M.L.; Goth-Goldstein, R.; Apte, M.G.; Fisk, W.J.

    2002-01-01

    About 50% of viral-induced respiratory illnesses are caused by the human rhinovirus (HRV). Measurements of the concentrations and sizes of bioaerosols are critical for research on building characteristics, aerosol transport, and mitigation measures. We developed a quantitative reverse transcription-coupled polymerase chain reaction (RT-PCR) assay for HRV and verified that this assay detects HRV in nasal lavage samples. A quantitation standard was used to determine a detection limit of 5 fg of HRV RNA with a linear range over 1000-fold. To measure the size distribution of HRV aerosols, volunteers with a head cold spent two hours in a ventilated research chamber. Airborne particles from the chamber were collected using an Andersen Six-Stage Cascade Impactor. Each stage of the impactor was analyzed by quantitative RT-PCR for HRV. For the first two volunteers with confirmed HRV infection, but with mild symptoms, we were unable to detect HRV on any stage of the impactor.

  16. Agreement assessment in size measurement of hepatic metastases

    Science.gov (United States)

    Zheng, Yangchen; Karademir, Ibrahim; Wise, Leon; Oto, Aytekin; Peng, Yahui

    2017-01-01

    The purpose of the study was to investigate patient-wise agreement among multiparametric magnetic resonance (MR) imaging sequences and radiologists, respectively, in the size assessment of hepatic metastases. A total of 30 liver metastases were identified from 20 patients and three radiologists independently measured the long and short axes for all metastases in T1-weighted, T2-weighted, diffusion-weighted imaging (DWI) with b of 0 and 800 s/mm2, and the apparent diffusion coefficient (ADC) map. We calculated the patient-wise intraclass correlation coefficient (ICCs) to estimate the interobserver and intersequence agreement in measured lesion size. Interobserver ICCs were 0.92-0.98 for different MR sequences and intersequence ICCs were 0.93-0.98. In conclusion, multiparametric MR imaging is a reliable tool for hepatic metastatic lesion measurement.

  17. Measuring liquid meniscus velocity to determine size of nanopipette aperture.

    Science.gov (United States)

    Salançon, Evelyne; Tinland, Bernard

    2013-02-15

    Nanopipette aperture sizes up to 25 nm are determined here using a method based on the Poiseuille law. Pressure is applied to the backside of a liquid plug placed in the widest end of the nanopipette, resulting in an air pressure tank with an aperture at the very tip of the nanopipette. Measuring the velocity of the liquid meniscus gives the air flow and thus the aperture size. Aperture determinations are in good agreement with SEM estimations and the proposed method is simple, relatively fast, and cheap. Copyright © 2012 Elsevier Inc. All rights reserved.

  18. Acoustic measurement of bubble size in an inkjet printhead.

    Science.gov (United States)

    Jeurissen, Roger; van der Bos, Arjan; Reinten, Hans; van den Berg, Marc; Wijshoff, Herman; de Jong, Jos; Versluis, Michel; Lohse, Detlef

    2009-11-01

    The volume of a bubble in a piezoinkjet printhead is measured acoustically. The method is based on a numerical model of the investigated system. The piezo not only drives the system but it is also used as a sensor by measuring the current it generates. The numerical model is used to predict this current for a given bubble volume. The inverse problem is to infer the bubble volume from an experimentally obtained piezocurrent. By solving this inverse problem, the size and position of the bubble can thus be measured acoustically. The method is experimentally validated with an inkjet printhead that is augmented with a glass connection channel, through which the bubble was observed optically, while at the same time the piezocurrent was measured. The results from the acoustical measurement method correspond closely to the results from the optical measurement.

  19. Measurements of Hygroscopicity- and Size-Resolved Sea Spray Aerosol

    Science.gov (United States)

    Phillips, B.; Dawson, K. W.; Royalty, T. M.; Reed, R. E.; Petters, M.; Meskhidze, N.

    2015-12-01

    Atmospheric aerosols play a central role in many environmental processes by influencing the Earth's radiative balance, tropospheric chemistry, clouds, biogeochemical cycles, and visibility as well as adversely impacting human health. Based on their origin, atmospheric aerosols can be defined as anthropogenic or natural. Recent studies have shown that a large fraction of uncertainty in the radiative effects of anthropogenic aerosols is related to uncertainty in natural—background—aerosols. Marine aerosols are of particular interest due to the abundance of oceans covering the Earth's surface. Despite their importance, limited information is currently available for size- and composition-resolved marine aerosol emission fluxes. Our group has designed and built an instrument for measuring the size- and hygroscopicity-resolved sea spray aerosol fluxes. The instrument was first deployed during spring 2015 at the end of the 560 m pier of the US Army Corps of Engineers' Field Research Facility in Duck, NC. Measurements include 200 nm-sized diameter growth factor (hygroscopicity) distributions, sea spray particle flux measurements, and total sub-micron sized aerosol concentration. Ancillary ocean data includes salinity, pH, sea surface temperature, dissolved oxygen content, and relative fluorescence (proxy for [Chl-a]). Hygroscopicity distribution measurements show two broad peaks, one indicative of organics and sulfates and another suggestive of sea salt. The fraction of 200 nm-sized salt particles having hygroscopicity similar to that of sea-spray aerosol contributes up to ~24% of the distribution on days with high-speed onshore winds and up to ~3% on calm days with winds blowing from the continent. However, the total concentration of sea-spray-like particles originating from offshore versus onshore winds was relatively similar. Changes in the relative contribution of sea-salt to number concentration were caused by a concomitant changes in total aerosol concentration

  20. Reproducibility of airway luminal size in asthma measured by HRCT.

    Science.gov (United States)

    Brown, Robert H; Henderson, Robert J; Sugar, Elizabeth A; Holbrook, Janet T; Wise, Robert A

    2017-10-01

    Brown RH, Henderson RJ, Sugar EA, Holbrook JT, Wise RA, on behalf of the American Lung Association Airways Clinical Research Centers. Reproducibility of airway luminal size in asthma measured by HRCT. J Appl Physiol 123: 876-883, 2017. First published July 13, 2017; doi:10.1152/japplphysiol.00307.2017.-High-resolution CT (HRCT) is a well-established imaging technology used to measure lung and airway morphology in vivo. However, there is a surprising lack of studies examining HRCT reproducibility. The CPAP Trial was a multicenter, randomized, three-parallel-arm, sham-controlled 12-wk clinical trial to assess the use of a nocturnal continuous positive airway pressure (CPAP) device on airway reactivity to methacholine. The lack of a treatment effect of CPAP on clinical or HRCT measures provided an opportunity for the current analysis. We assessed the reproducibility of HRCT imaging over 12 wk. Intraclass correlation coefficients (ICCs) were calculated for individual airway segments, individual lung lobes, both lungs, and air trapping. The ICC [95% confidence interval (CI)] for airway luminal size at total lung capacity ranged from 0.95 (0.91, 0.97) to 0.47 (0.27, 0.69). The ICC (95% CI) for airway luminal size at functional residual capacity ranged from 0.91 (0.85, 0.95) to 0.32 (0.11, 0.65). The ICC measurements for airway distensibility index and wall thickness were lower, ranging from poor (0.08) to moderate (0.63) agreement. The ICC for air trapping at functional residual capacity was 0.89 (0.81, 0.94) and varied only modestly by lobe from 0.76 (0.61, 0.87) to 0.95 (0.92, 0.97). In stable well-controlled asthmatic subjects, it is possible to reproducibly image unstimulated airway luminal areas over time, by region, and by size at total lung capacity throughout the lungs. Therefore, any changes in luminal size on repeat CT imaging are more likely due to changes in disease state and less likely due to normal variability.NEW & NOTEWORTHY There is a surprising lack of

  1. Rupture Properties of Blood Vessel Walls Measured by Pressure-Imposed Test

    Science.gov (United States)

    Ohashi, Toshiro; Sugita, Syukei; Matsumoto, Takeo; Kumagai, Kiichiro; Akimoto, Hiroji; Tabayashi, Koichi; Sato, Masaaki

    It is expected to be clinically useful to know the mechanical properties of human aortic aneurysms in assessing the potential for aneurysm rupture. For this purpose, a newly designed experimental setup was fabricated to measure the rupture properties of blood vessel walls. A square specimen of porcine thoracic aortas is inflated by air pressure at a rate of 10mmHg/s (≈1.3MPa/s) until rupture occurs. Mean breaking stress was 1.8±0.4 MPa (mean±SD) for the specimens proximal to the heart and 2.3±0.8MPa for the distal specimens, which are not significantly different to those values obtained longitudinally from conventional tensile tests. Moreover, the local breaking stretch ratio in the longitudinal direction was significantly higher at the ruptured site (2.7±0.5) than at the unruptured site (2.2±0.4). This testing system for studying the rupture properties of aortic walls is expected to be applicable to aortic aneurysms. Experimental verification of the present technique for the homogeneous, isotropic material is also presented.

  2. Studying fluid-to-particle heat transfer coefficients in vessel cooking processes using potatoes as measuring devices

    DEFF Research Database (Denmark)

    Feyissa, Aberham Hailu; Christensen, Martin Gram; Pedersen, Søren Juhl

    2015-01-01

    This paper presents and demonstrates a novel idea of using spherical potatoes as a dispensable, cheap device for determining the fluid-to-particle heat transfer coefficient, hfp in vessel cooking processes. The transmission of heat through the potato can be traced by measuring the distance from t...

  3. Spray ignition measurements in a constant volume combustion vessel under engine-relevant conditions

    Science.gov (United States)

    Ramesh, Varun

    Pressure-based and optical diagnostics for ignition delay (ID) measurement of a diesel spray from a multi-hole nozzle were investigated in a constant volume combustion vessel (CVCV) at conditions similar to those in a conventional diesel engine at the start of injection (SOI). It was first hypothesized that compared to an engine, the shorter ID in a CVCV was caused by NO, a byproduct of premixed combustion. The presence of a significant concentration of NO+NO2 was confirmed experimentally and by using a multi-zone model of premixed combustion. Experiments measuring the effect of NO on ID were performed at conditions relevant to a conventional diesel engine. Depending on the temperature regime and the nature of the fuel, NO addition was found to advance or retard ignition. Constant volume ignition simulations were capable of describing the observed trends; the magnitudes were different due to the physical processes involved in spray ignition, not modeled in the current study. The results of the study showed that ID is sensitive to low NO concentrations (temperature regime. A second source of uncertainty in pressure-based ID measurement is the systematic error associated with the correction used to account for the speed of sound. Simultaneous measurements of volumetric OH chemiluminescence (OHC) and pressure during spray ignition found the OHC to closely resemble the pressure-based heat release rate for the full combustion duration. The start of OHC was always found to be shorter than the pressure-based ID for all fuels and conditions tested by 100 ms. Experiments were also conducted measuring the location and timing of high-temperature ignition and the steady-state lift-off length by high-speed imaging of OHC during spray ignition. The delay period calculated using the measured ignition location and the bulk average speed of sound was in agreement with the delay between OHC and the pressure-based ID. Results of the study show that start of OHC is coupled to

  4. Two measures of effective population size for graphs.

    Science.gov (United States)

    Broom, Mark; Voelkl, Bernhard

    2012-05-01

    Effective population size is a key parameter in population ecology because it allows prediction of the dynamics of genetic variation and the rate of genetic drift and inbreeding. It is important for the definition of "nearly neutral" mutations and, hence, has consequences for the fixation or extinction probabilities of advantageous and deleterious mutations. As graph-based population models become increasingly popular for studying evolution in spatially or socially structured populations, a neutral theory for evolution on graphs is called for. Here, we derive formulae for two alternative measures of effective population size, the variance effective and inbreeding effective size of general unweighted and undirected graphs. We show how these two quantities relate to each other and we derive effective sizes for the complete graph the cycle and bipartite graphs. For one-dimensional lattices and small-world graphs, we estimate the inbreeding effective size using simulations. The presented method is suitable for any structured population of haploid individuals with overlapping generations. © 2012 The Author(s). Evolution© 2012 The Society for the Study of Evolution.

  5. Hemodynamic significance of coronary stenosis by vessel attenuation measurement on CT compared with adenosine perfusion MRI

    Energy Technology Data Exchange (ETDEWEB)

    Dekker, Martijn A.M. den; Pelgrim, Gert Jan; Pundziute, Gabija; Heuvel, Edwin R. van den; Oudkerk, Matthijs; Vliegenthart, Rozemarijn, E-mail: r.vliegenthart@umcg.nl

    2015-01-15

    Highlights: • The majority of anatomical coronary stenoses do not cause myocardial ischemia. • cCTA-derived CCO decrease expresses luminal density gradient across stenosis. • CCO decrease differentiates between anatomical stenoses with and without associated myocardial ischemia. • CCO decrease assessment can exclude the majority of stenoses without hemodynamic significance. - Abstract: Purpose: We assessed the association between corrected contrast opacification (CCO) based on coronary computed tomography angiography (cCTA) and inducible ischemia by adenosine perfusion magnetic resonance imaging (APMR). Methods: Sixty cardiac asymptomatic patients with extra-cardiac arterial disease (mean age 64.4 ± 7.7 years; 78% male) underwent cCTA and APMR. Luminal CT attenuation values (Hounsfield Units) were measured in coronary arteries from proximal to distal, with additional measurements across sites with >50% lumen stenosis. CCO was calculated by dividing coronary CT attenuation by descending aorta CT attenuation. A reversible perfusion defect on APMR was considered as myocardial ischemia. Results: In total, 169 coronary stenoses were found. Seven patients had 8 perfusion defects on APMR, with 11 stenoses in corresponding vessels. CCO decrease across stenoses with hemodynamic significance was 0.144 ± 0.112 compared to 0.047 ± 0.104 across stenoses without hemodynamic significance (P = 0.003). CCO decrease in lesions with and without anatomical stenosis was similar (0.054 ± 0.116 versus 0.052 ± 0.101; P = 0.89). Using 0.20 as preliminary CCO decrease cut-off, hemodynamic significance would be excluded in 82.9% of anatomical stenoses. Conclusions: CCO decrease across coronary stenosis is associated with myocardial ischemia on APMR. CCO based on common cCTA data is a novel method to assess hemodynamic significance of anatomical stenosis.

  6. Normalizing hip muscle strength: establishing body-size-independent measurements.

    Science.gov (United States)

    Bazett-Jones, David M; Cobb, Stephen C; Joshi, Mukta N; Cashin, Susan E; Earl, Jennifer E

    2011-01-01

    To investigate the effectiveness of computing body-size-independent hip strength measures using muscle-specific allometric scaling and ratio standard normalization methods. Cross-sectional study. University laboratory. A convenience sample of healthy participants (N=113; 42 men, 71 women). Not applicable. Anthropometric measurements of the leg and thigh were obtained, and maximal hip strength was tested (medial and lateral rotation, abduction, adduction, flexion, extension). Strength was measured isometrically as force (kg) and then converted to torque (Nm). The allometric scaling analysis resulted in exponents for normalizing body mass (BM) in each muscle group assessed. In addition, a 6-muscle average exponent was also computed (bavg) for force (men, .554; women, .335) and torque (men, .792; women, .482). The nonsignificant results of the linear regression analysis revealed that normalizing hip strength to BM(bavg) (hip strength/BM(bavg)) effectively removed the influence of BM on force and torque. However, sex should be factored into analyses of allometric scaling because men have higher b-values than women for both force and torque. The linear regression analyses also demonstrated that force normalized to BM (P=.162-.895) and torque normalized to BM × Height (P=.146-.889) were body-size-independent measures. Force normalized to BM⁰·⁶⁷ (P=.001-.191) and body mass index (BMI) (P=normalized to BM (P=.004-.415) and BMI (PNormalizing force and torque to BM(bavg) is the most effective method of removing body-size dependence and allowing comparisons of persons with differing body sizes. Copyright © 2011 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  7. Vessel Operating Units (Vessels)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains data for vessels that are greater than five net tons and have a current US Coast Guard documentation number. Beginning in1979, the NMFS...

  8. Non-invasive measurments of intense relativistic electron beam size

    Science.gov (United States)

    Ekdahl, Carl; McCuistian, Trent; Moir, David; Rodriguez, Patrick; Broste, William; Johnson, Jeff

    2000-10-01

    To understand relativistic electron beam transport dynamics the size of the beam is often measured using invasive techniques such as imaging the Cerenkov or OTR light emitted from a screen inserted into the beam. These techniques would completely disrupt the DARHT 2 beam, so we are developing a non-invasive method using diamagnetic loops. We show that through conservation of canonical angular momentum the RMS radius of the beam can be found by measuring the magnetic flux excluded by the diamagnetic beam. Furthermore, this measurement is shown to be independent of the details of the beam radial current profile for DARHT 2 parameters. We present results from our test and calibration experiments, as well as results of beam radius measurements on the 20-MeV DARHT 1 accelerator.

  9. Quantitative measurement of out-of-plan deformation generated at the around defect of pressure vessel using shearography

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kyoung Suk; Beak, Sang Kyu; Lee, Gun Jung; Chang, Ho Seob [Chosun University, Kwangju (Korea, Republic of); Kang, Myoung Goo [Chosun University RRC, Kwangju (Korea, Republic of); Kim, Sung Sik [Mokpo Science College, Mokpo(Korea, Republic of)

    2006-05-15

    Shearography, one of NDT methods without contact, is able to inspect defects of pipelines and pressure vessels that are used in the industrial machine and nuclear power plants and is used to determine safety, maintenance, and mending. Electronic Speckle Pattern Interferometry(ESPI) is a common method for measuring out-of-plane deformation and in-plane deformation and applied for vibration analysis and strain/stress analysis. However, ESPI is sensitive to environmental disturbance, which provide the limitation of industrial application. On the other hand, Shearography based on shearing interferometer which is insensitive to vibration disturbance can directly measure the first derivative of out-of-plane deformation. In this paper a technique that extract out-of-plane deformation from results of shearography by numerical processing is proposed and measurement results of ESPI and Shearoraphy are compared quantitative to inspect defects of pipelines and pressure vessels.

  10. Particle shape effects on subvisible particle sizing measurements.

    Science.gov (United States)

    Cavicchi, Richard E; Carrier, Michael J; Cohen, Joshua B; Boger, Shir; Montgomery, Christopher B; Hu, Zhishang; Ripple, Dean C

    2015-03-01

    Particle analysis tools for the subvisible (shape in comparison studies, we have used the methods of photolithography to create rods and disks. Although the rods are highly monodisperse, the instruments produce broadened peaks and report mean size parameters that are different for different instruments. We have fabricated a microfluidic device that simultaneously performs ESZ and FI measurements on each particle to elucidate the causes of discrepancies and broadening. Alignment of the rods with flow causes an oversizing by FI and undersizing by ESZ. FI also oversizes rods because of the incorrect edge definition that results from diffraction and imperfect focus. We present an improved correction algorithm for this effect that reduces discrepancies for rod-shaped particles. Tumbling of particles is observed in the microfluidic ESZ/FI and results in particle oversizing and breadth of size distribution for the monodisperse rods. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association.

  11. A power analysis for fidelity measurement sample size determination.

    Science.gov (United States)

    Stokes, Lynne; Allor, Jill H

    2016-03-01

    The importance of assessing fidelity has been emphasized recently with increasingly sophisticated definitions, assessment procedures, and integration of fidelity data into analyses of outcomes. Fidelity is often measured through observation and coding of instructional sessions either live or by video. However, little guidance has been provided about how to determine the number of observations needed to precisely measure fidelity. We propose a practical method for determining a reasonable sample size for fidelity data collection when fidelity assessment requires observation. The proposed methodology is based on consideration of the power of tests of the treatment effect of outcome itself, as well as of the relationship between fidelity and outcome. It makes use of the methodology of probability sampling from a finite population, because the fidelity parameters of interest are estimated over a specific, limited time frame using a sample. For example, consider a fidelity measure defined as the number of minutes of exposure to a treatment curriculum during the 36 weeks of the study. In this case, the finite population is the 36 sessions, the parameter (number of minutes over the entire 36 sessions) is a total, and the sample is the observed sessions. Software for the sample size calculation is provided. (c) 2016 APA, all rights reserved).

  12. 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...

  13. 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...

  14. Measuring coral size-frequency distribution using stereo video technology, a comparison with in situ measurements.

    Science.gov (United States)

    Turner, Joseph A; Polunin, Nicholas V C; Field, Stuart N; Wilson, Shaun K

    2015-05-01

    Coral colony size-frequency distribution data offer valuable information about the ecological status of coral reefs. Such data are usually collected by divers in situ, but stereo video is being increasingly used for monitoring benthic marine communities and may be used to collect size information for coral colonies. This study compared the size-frequency distributions of coral colonies obtained by divers measuring colonies 'in situ' with digital video imagery collected using stereo video and later processed using computer software. The size-frequency distributions of the two methods were similar for corymbose colonies, although distributions were different for massive, branching and all colonies combined. The differences are mainly driven by greater abundance of colonies >50 cm and fewer colonies 5 cm and was able to record measurements on 87% of the colonies detected. However, stereo video only detected 57% of marked colonies coral recruits. Estimates of colony size made with the stereo video were smaller than the in situ technique for all growth forms, particularly for massive morphologies. Despite differences in size distributions, community assessments, which incorporated genera, growth forms and size, were similar between the two techniques. Stereo video is suitable for monitoring coral community demographics and provided data similar to in situ measure for corymbose corals, but the ability to accurately measure massive and branching coral morphologies appeared to decline with increasing colony size.

  15. Adjusting wheal size measures to correct atopy misclassification

    Directory of Open Access Journals (Sweden)

    Zhang H

    2011-08-01

    Full Text Available Hongmei Zhang1,*, Wilfried Karmaus1,*, Jianjun Gan2, Weichao Bao1,*, Yan D Zhao3, Dewi Rahardja3, John W Holloway5, Martha Scott4,5, Syed Hasan Arshad4,51Department of Epidemiology and Biostatistics, The University of South Carolina, Columbia, SC, USA; 2GlaxoSmithKline, Research Triangle Park, NC, USA; 3Department of Clinical Science and Simmons Cancer Center, UT Southwestern Medical Center, Dallas, TX, USA; 4The David Hide Asthma and Allergy Research Center, St Mary’s Hospital, Newport, Isle of Wight, UK; 5School of Medicine, University of Southampton, Southampton, UK *These authors contributed equally to this articlePurpose: Skin prick testing (SPT is fundamental to the practice of clinical allergy identifying relevant allergens and predicting the clinical expression of disease. Wheal sizes on SPT are used to identify atopic cases, and the cut-off value for a positive test is commonly set at 3 mm. However, the measured wheal sizes do not solely reflect the magnitude of skin reaction to allergens, but also skin reactivity (reflected in the size of histamine reaction and other random or non-random factors. We sought to estimate wheal sizes exclusively due to skin response to allergens and propose gender-specific cutoff points of atopy.Methods: We developed a Bayesian method to adjust observed wheal sizes by excluding histamine and other factor effects, based on which revised cutoff points are proposed for males and females, respectively. The method is then applied to and intensively evaluated using a study population aged 18, at a location on the Isle of Wight in the United Kingdom. To evaluate the proposed approach, two sample t-tests for population means and proportion tests are applied.Results: Four common aeroallergens, house dust mite (HDM, grass pollen, dog dander, and alternaria are considered in the study. Based on 3 mm cutoff, males tend to be more atopic than females (P-values are between 0.00087 and 0.062. After applying the

  16. Strain measurement during stress rupture of composite over-wrapped pressure vessel with fiber Bragg gratings sensors

    Science.gov (United States)

    Banks, Curtis E.; Grant, Joseph; Russell, Sam; Arnett, Shawn

    2008-03-01

    Fiber optic Bragg gratings were used to measure strain fields during Stress Rupture (SSM) test of Kevlar Composite Over-Wrapped Pressure Vessels (COPVs). The sensors were embedded under the over-wrapped attached to the liner released from the Kevlar and attached to the Kevlar released from the liner. Additional sensors (foil gages and fiber bragg gratings) were surface mounted on the COPV liner.

  17. Powerful New Technique to Measure Asteroids' Sizes and Shapes

    Science.gov (United States)

    2009-02-01

    A team of French and Italian astronomers have devised a new method for measuring the size and shape of asteroids that are too small or too far away for traditional techniques, increasing the number of asteroids that can be measured by a factor of several hundred. This method takes advantage of the unique capabilities of ESO's Very Large Telescope Interferometer (VLTI). ESO PR Photo 04a/09 Asteroid Barbara (artist's impression) "Knowledge of the sizes and shapes of asteroids is crucial to understanding how, in the early days of our Solar System, dust and pebbles collected together to form larger bodies and how collisions and re-accumulation have since modified them," says Marco Delbo from the Observatoire de la Côte d'Azur, France, who led the study. Direct imaging with adaptive optics on the largest ground-based telescopes such as the Very Large Telescope (VLT) in Chile (see ESO 21/05 and 18/07), and space telescopes, or radar measurements (ESO 11/07) are the currently favoured methods of asteroid measurement. However, direct imaging, even with adaptive optics, is generally limited to the one hundred largest asteroids of the main belt, while radar measurements are mostly constrained to observations of near-Earth asteroids that experience close encounters with our planet. Delbo and his colleagues have devised a new method that uses interferometry to resolve asteroids as small as about 15 km in diameter located in the main asteroid belt, 200 million kilometres away. This is equivalent to being able to measure the size of a tennis ball a distance of a thousand kilometres. This technique will not only increase the number of objects that can be measured dramatically, but, more importantly, bring small asteroids that are physically very different from the well studied larger ones into reach. The interferometric technique combines the light from two or more telescopes. Astronomers proved their method using ESO's VLTI, combining the light of two of the VLT's 8.2-metre

  18. The small-sized ultraprecision sensor for measuring linear displacements

    Science.gov (United States)

    Lushnikov, D. S.; Zherdev, A. Y.; Odinokov, S. B.; Markin, V. V.; Gurylev, O. A.; Shishova, M. V.

    2017-06-01

    The article describes a new optical scheme of noncontact sensor for measuring linear displacement - linear encoder. This sensor is an optical device in which the measurement of displacement is performed by analyzing the optical signal, which pass through two diffraction gratings, one of which is moved relative to the other. The optical signal is obtained by the diffraction of light in these diffraction gratings and subsequent interference of diffracted beams. Often this type of sensors are multi-channel devices with symmetrically positioned of detectors. This scheme is proposed to use a multisection phase mask that allows to make a small-sized sensor. Sections of this multi-section phase mask are the optical windows and they made the final interference signals to be shifted relative to each other in phase. The number of sections in the multi-section phase mask can be varied. Estimated sufficient number of sections is four or more.

  19. Effect of specimen size on work-of-fracture measurements.

    Science.gov (United States)

    Rogers, L L; Moyle, D D

    1988-01-01

    It has been suggested that work-of-fracture, which quantifies the ability of a material to resist fracture, is dependent on specimen size. This experiment compared work-of-fracture, calculated as energy per unit area, for different specimen sizes of Plexiglas, bovine tibial bone and aluminum. Three different geometrically similar cross sections were tested for each material for a total of 54 specimens. Work-of-fracture was measured by loading a notched beam (triangular cross section) in three-point bending at a constant deformation rate. The energy necessary to cause fracture was measured from a load-deformation curve. Specimen fracture area was determined using macrophotography. Atomic absorption spectrophotometry was used to determine weight percent calcium of bone specimens and quantitative light microscopy was used to determine fractional void area. Analysis of variance showed no effect of specimen size on work-of-fracture for aluminum or Plexiglas specimens (p greater than 0.05). A significant difference was found, however, between the large (area = 11.7 +/- 1.9 mm2) and small (area = 3.48 +/- 0.68 mm2) bone specimens and between the medium (area = 5.89 +/- 0.69 mm2) and small (area = 3.48 +/- 0.68 mm2) bone specimens. No correlation was found between work-of-fracture and either calcium content (r2 = 0.128) or fractional void area (r2 = 0.0713). The mean work-of-fracture values found are as follows: aluminum, 59.8 +/- 13.7 kJ m-2; Plexiglas, 0.620 +/- 0.074 kJ m-2; bone (area 5.89 +/- 0.69 mm2-11.7 +/- 1.9 mm2), 9.72 +/- 1.93 kJ m-2 and bone (area 3.48 +/- 0.68 mm2), 5.48 +/- 1.79 kJ m-2.

  20. Experimental Study Using Functional Size Measurement in Building Estimation Models for Software Project Size

    NARCIS (Netherlands)

    Condori-Fernandez, Nelly; Daneva, Maia; Buglione, Luigi; Ormandjieva, Olga; Ormandjieva, O.; Constantinides, C.; Abran, A.; Lee, R.

    2010-01-01

    This paper reports on an experiment that investigates the predictability of software project size from software product size. The predictability research problem is analyzed at the stage of early requirements by accounting the size of functional requirements as well as the size of non-functional

  1. Median ellipse parameterization for robust measurement of fuel droplet size

    Science.gov (United States)

    Greminger, Michael; Hoxie, Alison

    2016-02-01

    The combustion properties of blended fuel combinations can be characterized by performing single droplet fuel combustion experiments. These combustion experiments are visualized using high speed image acquisition. Once the high speed images are obtained, the burn rate and other characteristics of combustion, such as the occurrence of microexplosions, can be characterized. Currently these quantities are either measured manually or are measured using automated software. However, the current software packages used for this task are limited in that they can only measure droplets that are elliptical in shape and manual corrections often have to be made to avoid significant errors in the measurement. An automated droplet tracking algorithm is presented that can automatically track droplet size without manual intervention due to its robustness to the presence of missing or extra edges in the images. In addition, the proposed method can track shapes more general than ellipses, which is required in order to track the droplet during microexplosions. The proposed algorithm starts by fitting ellipses to numerous five point subsets from the droplet edge data. The closed contour is parameterized by determining the median perimeter of the set of ellipses. The resulting curve is not an ellipse, allowing arbitrary closed contours to be parameterized. The performance of the proposed algorithm and the performance of existing algorithms are compared to a ground truth segmentation of the fuel droplet images. This comparison demonstrates that the median ellipse parameterization algorithm has improved performance for both area quantification and edge deviation.

  2. Measurement of Heat Transfer Coefficients in an Agitated Vessel with Tube Baffles

    OpenAIRE

    M. Dostál; Petera, K.; Rieger, F.

    2010-01-01

    Cooling or heating an agitated liquid is a very common operation in many industrial processes. A classic approach is to transfer the necessary heat through the vessel jacket. Another option, frequently used in the chemical and biochemical industries is to use the heat transfer area of vertical tube baffles. In large equipment, e.g. fermentor, the jacket surface is often not sufficient for large heat transfer requirements and tube baffles can help in such cases. It is then important to know th...

  3. Large eddy simulation of a pitched blade impeller mixed vessel - Comparison with LDA measurements

    Czech Academy of Sciences Publication Activity Database

    Vlček, P.; Kysela, Bohuš; Jirout, T.; Fořt, I.

    2016-01-01

    Roč. 108, April (2016), s. 42-48 ISSN 0263-8762. [15th European Conference on Mixing. St. Petersburg, 28.06.2016-03.07.2016] Institutional support: RVO:67985874 Keywords : CFD * LES * mixed vessel * pitched six-blade impeller * ensemble averaged mean velocity * flow rate Subject RIV: BK - Fluid Dynamics Impact factor: 2.538, year: 2016 http://www.sciencedirect.com/science/article/pii/S0263876216000836

  4. Development of a multiple wavelength extinction diagnostic for measuring ejecta particle size distributions.

    Science.gov (United States)

    Steele, Paul; Compton, Steve; Jacoby, Barry; Filip, Catalin; Frank, Matthias; Phillips, Danial; Sinibaldi, Jose O.

    2017-06-01

    Mie's solution of Maxwell's equations for the interaction of light with spherical particles shows that particle diameter has a dramatic impact on the amount of light scattered or absorbed by a particle. The ratio of particle size to wavelength is particularly important. By measuring the transmission through a sheet of ejecta at multiple wavelengths and making certain assumptions, it is possible to estimate the ejecta particle size distribution. The Multiple Wavelength Extinction (MWE) diagnostic is being developed at Lawrence Livermore National Laboratory (LLNL) to do just that. Various potential system configurations were initially evaluated using a computer model developed in MATLAB. Inexpensive hardware (MWE Beta) was acquired for a basic proof-of-concept experiment using calibrated test particles. Encouraging results enabled procurement of better hardware. Characterization and testing of this MWE 1.0 system is ongoing. MWE 2.0 is now being designed. Ejecta experiments require a high explosive drive, an array of ejecta diagnostics and containment vessels, all of which are readily available at LLNL's High Explosives Application Facility. LLNL-ABS-723858. Prepared by LLNL under Contract DE-AC52-07NA27344.

  5. Understanding the shape of the Earth and measuring its size

    Science.gov (United States)

    Baltatzis, Evangelos; Galanaki, Angeliki

    2016-04-01

    Most elementary students have problems and misconceptions regarding the shape of the Earth. Teachers often contribute to this confusion telling the students that the Earth is almost spherical, but not explaining to them, how the Earth can be spherical while it appears. It would be helpful for students to understand how humanity came with the idea of the spherical Earth (to be precise the Earth is ellipsoid). Historically, most cultures describe the Earth as flat. That changes with the ancient Greek culture. We don't know exactly how the Greeks first understood the spherical shape of the Earth, but some Greek philosophers give some arguments why the Earth must be a sphere. We can discuss these arguments and observations with the students. First, if someone travels in the south, he can see the southern constellations rise higher above the horizon. We can give students pictures of the night sky in southern regions and compare them with observations of ''their'' night sky. Second, in the lunar eclipse we can see the round shadow of the Earth. Third, whenever a ship is on the horizon, his low part is invisible . This is known as "hull-down". Moreover, the low part of mountains is invisible from the sea, due to the curvature of the Earth. It is always better to make these observations in real life but it can also be done via videos and pictures. The realization of the spherical shape of the Earth was sine qua non for the first good measurement of its size. In the second part of the project, following the ancient mathematician Eratosthenes's steps, students can measure the size of the Earth, , find pleasure in doing experimental work and realize how important mathematics is in everyday life. Two sticks, situated a long distance away from each other, can give us approximately the circumference , the radius and the diameter of the Earth. Eratosthenes used geometry combined to the knowledge of ancient Greek culture that the Earth is spherical (360°). He knew the distance

  6. Influence of tonsil size on sagittal cephalometric measurements.

    Science.gov (United States)

    Diouf, Joseph Samba; Ngom, Papa Ibrahima; Fadiga, Mohamed Siddick; Badiane, Alpha; Diop-Ba, Khady; Sonko, Ousmane; Diagne, Falou

    2015-06-01

    The role of tonsils in the origin of sagittal skeletodental abnormalities has been widely discussed in the literature but remains controversial. Data on the probable relationship between enlarged tonsils and the presence of these abnormalities were subjective. The aim of this study was to quantify the relationship between the space occupied by the palatine tonsils and sagittal cephalometric measurements. A cross-sectional study was performed on a group of children divided into 5 subgroups according to the standardized tonsillar hypertrophy grading scale. Cephalometric measurements were recorded for each child. Data were analyzed using SPSS 20.0 for Windows. The strength of the association between tonsil grades and quantitative variables was assessed using Spearman's rank correlation coefficient (Rho). The level of significance was fixed at P=0.05. Lengths SN, t2-p3, h-Gn and Xi-pm, and angles I/F, I/SN, i/M, SNB, SNPog and SNGn were significantly and negatively correlated with grades. The ANB angle, the sagittal position of the pogonion and the angle of facial convexity were significantly and positively correlated with grades. Early evaluation of tonsil size can prevent certain skeletodental abnormalities in the sagittal plane caused by upper airway obstruction. Thus, more aggressive late treatments, which are not always as effective as when they are performed during childhood, can be avoided. Copyright © 2015 CEO. Published by Elsevier Masson SAS. All rights reserved.

  7. Turbulence and Beam Size Effects on Reflectometry Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Estrada, T.; Sanchez, J.; Zhuravlev, V.; Luna, E. de la; Branas, B. [Ciemat.Madrid (Spain)

    2000-07-01

    A two dimensional code based on the WKB approximation is used to simulate reflectometry measurements in plasmas with turbulence. The work aims to understand, first the role of turbulence in the determination of density profiles with reflectometry and, second, the ability of reflectometry techniques to give reliable information on the characteristics of the turbulence itself. The effects on the profile determination of a rotating turbulence structure with non-perpendicular reflection are analysed. The influence of the turbulence level, fluctuation wavelengths and antenna beam size on the density profile determination has been studied in a static plasma with perpendicular launching. The code has been used to simulate correlation measurements. The results show the correlation of the reflectometry signals for different turbulence parameters. Errors in the correlation length increase when 2-dimensional effects become important, though the homodyne signal works better than the phase. The correlation simulations also show the way for new methods to determine the group delay and therefore the density profile. (Author) 15 refs.

  8. Size histograms of gold nanoparticles measured by gravitational sedimentation.

    Science.gov (United States)

    Alexander, Colleen M; Goodisman, Jerry

    2014-03-15

    Sedimentation curves of gold nanoparticles in water were obtained by measuring the optical density of a suspension over time. The results are not subject to sampling errors, and refer to the particles in situ. Curves obtained simultaneously at several wave lengths were analyzed together to derive the size histogram of the sedimenting particles. The bins in the histogram were 5 nm wide and centered at diameters 60, 65, …, 110 nm. To get the histogram, we weighted previously calculated solutions to the Mason-Weaver sedimentation-diffusion equation for various particle diameters with absorption/scattering coefficients and size (diameter) abundances {c(j)}, and found the {c(j)} which gave the best fit to all the theoretical sedimentation curves. The effects of changing the number of bins and the wave lengths used were studied. Going to smaller bins would mean determining more parameters and require more wave lengths. The histograms derived from sedimentation agreed quite well in general with the histogram derived from TEM. Differences found for the smallest particle diameters are partly due to statistical fluctuations (TEM found only 1-2 particles out of 103 with these diameters). More important is that the TEM histogram indicates 12% of the particles have diameters of 75±2.5 nm, and the sedimentation histogram shows none. We show that this reflects the difference between the particles in situ, which possess a low-density shell about 1 nm thick, and the bare particles on the TEM stage. Correcting for this makes agreement between the two histograms excellent. Comparing sedimentation-derived with TEM-derived histograms thus shows differences between the particles in situ and on the TEM stage. Copyright © 2013 Elsevier Inc. All rights reserved.

  9. Finding the right RoPax vessel size and freight price. A coste and mode choice model

    Energy Technology Data Exchange (ETDEWEB)

    Morales Fusco, P.; Grau Sala, M.; Sauri Marchan, S.

    2016-07-01

    Motorways of the sea operated as RoPax services are natural competitors with only-road freight haulage transportation. Cost, time and quality perceived are the determinants that make transporters and shippers use one route or another. This research considers the role that shipping companies and their ship deployment and pricing strategy have in the equation, as incentives for modal shift from road to sea. A model of the ships and transporter costs is developed considering different business models for the transporter (accompanied versus unaccompanied cargo) followed with a discrete choice model that, once calibrated, allows to test the influence that variables such as frequency, ship size and commercial speed might play into the competitiveness of a shipping line. As a result, different pricing strategies for the shipping line are developed and the characteristics of the optimal shipping line for each of them are found, to either maximize the profit of the shipping company or the modal shift. (Author)

  10. Correlation of Anthropometric Measurements with Renal Sizes in ...

    African Journals Online (AJOL)

    Background: Renal dimensions are important for diagnosis and prognosis of nephropathies. These dimensions may be dependent on age and growth parameters. Is there any relationship between renal size and the derivatives of anthropometry? To determine the renal sizes in children sonographically and to correlate ...

  11. Vertebral scale system to measure heart size in thoracic radiographs ...

    African Journals Online (AJOL)

    In veterinary diagnostic radiology, determination of heart size is necessary in the assessment of patients with clinical signs of cardiac anomaly. In this study, heart sizes were compared with lengths of mid-thoracic vertebrae in 12 clinically normal West African Dwarf Goats (WADGs) (8 females, 4 males). The aim of the ...

  12. Computer-aided diagnosis of plus disease via measurement of vessel thickness in retinal fundus images of preterm infants.

    Science.gov (United States)

    Oloumi, Faraz; Rangayyan, Rangaraj M; Casti, Paola; Ells, Anna L

    2015-11-01

    Changes in the characteristics of retinal vessels such as width and tortuosity can be signs of the presence of several diseases such retinopathy of prematurity (ROP) and diabetic retinopathy. Plus disease is an indicator of ROP which requires treatment and is signified by an increase in posterior venular width. In this work, we present image processing techniques for the detection, segmentation, tracking, and measurement of the width of the major temporal arcade (MTA), which is the thickest venular branch in the retina. Several image processing techniques have been employed, including the use of Gabor filters to detect the MTA, morphological image processing to obtain its skeleton, Canny's method to detect and select MTA vessel-edge candidates, least-squares fitting to interpolate the MTA edges, and geometrical procedures to measure the width of the MTA. The results, obtained using 110 retinal fundus images of preterm infants, indicate a statistically highly significant difference in MTA width of normal cases as compared to cases with plus disease (pcomputer-aided diagnosis (CAD) of plus disease with an area under the receiver operating characteristic curve of 0.76. The proposed methods may be used in CAD of plus disease and timely treatment of ROP in a clinical or teleophthalmological setting. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Song repertoire size correlates with measures of body size in Eurasian blackbirds

    DEFF Research Database (Denmark)

    Hesler, Nana; Mundry, Roger; Sacher, Thomas

    2012-01-01

    In most oscine bird species males possess a repertoire of different song patterns. The size of these repertoires is assumed to serve as an honest signal of male quality. The Eurasian blackbird’s (Turdus merula) song contains a large repertoire of different element types with a flexible song organ...

  14. An analysis of the use of electrical power measurements for process control in large-scale stirred vessels

    Energy Technology Data Exchange (ETDEWEB)

    Hjorth, S.; Karlsson, L. [ABS Pump Peroduction AB SCABA Agitators, Taby (Sweden); Friberg, P. [Telemark Technological Research and Development Centre, Porsgrunn (Norway); Boon, L. [Birmingham Univ., (United Kingdom)

    2000-12-01

    Given that the direct measurement of the power transmitted via an agitator shaft is expensive as well as difficult to carry out, substitute measures such as inferring the transmitted power from a measurement of the electric power needed to operate the agitator motor, are frequently used. Although the accuracy of the measurement is highly inaccurate (less than five per cent accuracy), because of its relative simplicity and low cost, the technique is considered suitable for continuous monitoring of the power used by agitators in large-scale stirred vessels used in industrial processes. This paper describes a measurement method involving the use of a Wattmeter with a magnetic AC current probe fitted to the agitator. The major drawback is that for maximum accuracy the method needs to be calibrated which can be both tricky and cumbersome in all, except new installations. As an alternative, these authors suggest that if the speed control unit is close to being sinusoidal, accuracy levels of up to about 10 per cent can be achieved over a large range of torque and rpm values by accepting the manufacturer's estimate of efficiency. Examples of measurement results using various measurement techniques are discussed. 8 refs., 2 tabs., 6 figs.

  15. Space Shuttle exhausted aluminum oxide - A measured particle size distribution

    Science.gov (United States)

    Cofer, W. R., III; Purgold, G. C.; Edahl, R. A.; Winstead, E. L.

    1991-01-01

    Aluminum oxide (A2O3) particles were collected from the Space Shuttle exhaust plume immediately following the launch of STS-34 on October 18, 1989. A2O3 samples were obtained at 2.4, 3.0, 3.2, and 7.4 km in altitude. The samples were analyzed using SEM to develope particle size distributions. There were no indications that the particle size distribution changed as a function of altitude. The particle number concentrations per cubic meter of air sampled for the four collections was found to fit an exponential expression.

  16. Pixel size and pitch measurements of liquid crystal spatial light ...

    Indian Academy of Sciences (India)

    We present a simple technique for the determination of pixel size and pitch of liquid crystal (LC) based spatial light modulator (SLM). The proposed method is based on optical diffraction from pixelated LC panel that has been modeled as a two-dimensional array of rectangular apertures. A novel yet simple, two-plane ...

  17. Hybrid Segmentation of Vessels and Automated Flow Measures in In-Vivo Ultrasound Imaging

    DEFF Research Database (Denmark)

    Moshavegh, Ramin; Martins, Bo; Hansen, Kristoffer Lindskov

    2016-01-01

    method implements automated VFI flow measures such as peak systolic velocity (PSV) and volume flow. An evaluation of the performance of the segmentation algorithm relative to expert manual segmentation of 60 frames randomly chosen from 6 ultrasound sequences (10 frame randomly chosen from each sequence...... expert segmentations. The flowrig results also demonstrated that the PSVs measured from VFI had a mean relative error of 14.5% in comparison with the actual PSVs. The error for the PSVs measured from spectral Doppler was 29.5%, indicating that VFI is 15% more precise than spectral Doppler in PSV...

  18. Dosimetric and spectrometric neutron measurements around an annular vessel containing a plutonium nitrate fissile solution

    CERN Document Server

    Tournier, B; Medioni, R; Rich, C; Mussoni, F; Camus, L; Pichenot, G; Crovisier, P; Cutarella, D; Asselineau, B; Groetz, J E

    2002-01-01

    The new ICPR60 recommendations and the consideration of the ALARA principle have led the operators of nuclear facilities to evaluate with a higher care, the doses received by workers. The aim of this paper is to present a recent study concerning mixed field characterisation at a workplace located in a reprocessing laboratory. As a first step, neutron spectrum determination was achieved by two ways: simulation using MCNP code and experimental measurements with Bonner spheres and recoil proton counters. Neutron spectrum allowed the evaluation of dosimetric quantities. Measurements were then performed with different devices routinely used in radioprotection. The describe the measurement techniques, present the results obtained, and finally compare and discuss them.

  19. Development of the size calibration SOP for SEM measurement

    Science.gov (United States)

    Kwon, Hyuksang; Noh, Si Yeon; Song, Nam Woong

    2013-09-01

    The size and size distribution of nanomaterials are important factors for understanding their characteristics. A scanning electron microscopy (SEM) provides an easily accessible method to characterize nanostructures. We have developed a standard operating protocol (SOP) for the calibration of SEM by using CRMs (certified reference materials) of 1 dimensional (1D) gratings with 80 and 180 nm spacing, respectively, which have been certified by using a metrological AFM. To get consistent analysis results using a fast Fourier transform (FFT) method, the numbers of lateral and longitudinal pixels in the SEM images were determined for line profiling. We could also observed that the pitch values of 1D grating CRM could be obtained as the reference ones within the uncertainty under the following imaging conditions; the exposure time of the sample to the electron beam for an image scanning should be shorter than 120 s and the working distance from 5 to 8.9 mm can be used.

  20. Measuring EFL Students` Vocabulary Size: Why and How

    OpenAIRE

    Kurniawan, Iwan

    2016-01-01

    Students` vocabulary size plays very important role toward their success in learning new language. To succeed in language learning 2,000 word families is often mentioned. Having this number, a reader can understand nine from ten words in many written text. Right now, researchers propose number at least 3000 word families and mastering minimum 3000 word families will support students` success in academic reading at university level. To pass tests such as Cambridge First Certificate, TOEFL or ...

  1. A new tool to assess retinal vessel caliber. Reliability and validity of measures and their relationship with cardiovascular risk.

    Science.gov (United States)

    García-Ortiz, Luis; Recio-Rodríguez, José I; Parra-Sanchez, Javier; González Elena, Luis J; Patino-Alonso, María C; Agudo-Conde, Cristina; Rodríguez-Sánchez, Emiliano; Gómez-Marcos, Manuel A

    2012-04-01

    To analyze the reliability and validity of a semiautomated tool for assessing retinal vessel caliber and to describe the relationship of measures taken to cardiovascular risk and target organ damage. A total of 210 patients aged 34-75 years were selected with retinography. Retinal photographs were digitized, and superior and inferior temporal vessels were measured in an area 0.5-1 disk diameter from the optic disc with semiautomated software [arteriole/venule index (AVIx) calculator]. AVIx was also estimated. Vascular damage was assessed using carotid intima-media thickness and pulse wave velocity, cardiac damage using Cornell voltage-duration product, renal damage using the glomerular filtration rate and microalbuminuria, and cardiovascular risk with the Framingham score. Interobserver intraclass correlation coefficient (ICC) ranged from 0.96 [95% confidence interval (CI) 0.94-0.97] to 0.99 (95% CI 0.98-0.99), and intraobserver ICC ranged from 0.97 (95% CI 0.94-0.98) to 0.99 (95% CI 0.99-0.99). In the Bland-Altman plot, the limit of interobserver agreement was -0.009 (0.066 to -0.086) in right AVIx and -0.001 (0.083 to -0.085) in left AVIx, whereas the limit of intraobserver agreement for overall AVIx was -0.005 (-0.057 to -0.047). Cardiovascular risk and albumin-creatinine ratio were higher in the first tertile of AVIx as compared with the other two (P validity analysis agree with those from large studies in estimation of cardiovascular risk and evaluation of target organ damage.

  2. Secondary Electron Yield Measurements of Fermilab?s Main Injector Vacuum Vessel

    Energy Technology Data Exchange (ETDEWEB)

    Scott, D.J.; Capista, D.; Duel, K.L.; Zwaska, R.M.; /Fermilab; Greenwald, S.; Hartung, W.; Li, Y.; Moore, T.P.; Palmer, M.A.; /Cornell U.; Kirby, R.; Pivi, M.; /SLAC

    2012-05-01

    We discuss the progress made on a new installation in Fermilab's Main Injector that will help investigate the electron cloud phenomenon by making direct measurements of the secondary electron yield (SEY) of samples irradiated in the accelerator. In the Project X upgrade the Main Injector will have its beam intensity increased by a factor of three compared to current operations. This may result in the beam being subject to instabilities from the electron cloud. Measured SEY values can be used to further constrain simulations and aid our extrapolation to Project X intensities. The SEY test-stand, developed in conjunction with Cornell and SLAC, is capable of measuring the SEY from samples using an incident electron beam when the samples are biased at different voltages. We present the design and manufacture of the test-stand and the results of initial laboratory tests on samples prior to installation.

  3. Dosimetric and spectrometric neutron measurements around an annular vessel containing a plutonium nitrate fissile solution

    Science.gov (United States)

    Tournier, B.; Itié, C.; Médioni, R.; Rich, C.; Mussoni, F.; Camus, L.; Pichenot, G.; Crovisier, Ph.; Cutarella, D.; Asselineau, B.; Groetz, J. E.

    2002-01-01

    The new ICPR60 recommendations and the consideration of the ALARA principle have led the operators of nuclear facilities to evaluate with a higher care, the doses received by workers. The aim of this paper is to present a recent study concerning mixed field characterisation at a workplace located in a reprocessing laboratory. As a first step, neutron spectrum determination was achieved by two ways: simulation using MCNP code and experimental measurements with Bonner spheres and recoil proton counters. Neutron spectrum allowed the evaluation of dosimetric quantities. Measurements were then performed with different devices routinely used in radioprotection. The authors describe the measurement techniques, present the results obtained, and finally compare and discuss them.

  4. Acoustic measurement of bubble size in an inkjet printhead

    NARCIS (Netherlands)

    Jeurissen, R.J.M.; van der Bos, J.A.; van der Bos, Arjan; Reinten, Hans; van den Berg, Marc; Wijshoff, Herman; Wijshoff, H.; de Jong, J.; de Jong, Jos; Versluis, Michel; Lohse, Detlef

    2009-01-01

    The volume of a bubble in a piezoinkjet printhead is measured acoustically. The method is based on a numerical model of the investigated system. The piezo not only drives the system but it is also used as a sensor by measuring the current it generates. The numerical model is used to predict this

  5. Single-Size Thermometric Measurements on a Size Distribution of Neutral Fullerenes

    NARCIS (Netherlands)

    Cauchy, C.; Bakker, J. M.; Huismans, Y.; Rouzee, A.; Redlich, B.; van der Meer, A. F. G.; Bordas, C.; Vrakking, M. J. J.; Lepine, F.

    2013-01-01

    We present measurements of the velocity distribution of electrons emitted from mass-selected neutral fullerenes, performed at the intracavity free electron laser FELICE. We make use of mass-specific vibrational resonances in the infrared domain to selectively heat up one out of a distribution of

  6. Measuring optical properties of a blood vessel model using optical coherence tomography

    Science.gov (United States)

    Levitz, David; Hinds, Monica T.; Tran, Noi; Vartanian, Keri; Hanson, Stephen R.; Jacques, Steven L.

    2006-02-01

    In this paper we develop the concept of a tissue-engineered optical phantom that uses engineered tissue as a phantom for calibration and optimization of biomedical optics instrumentation. With this method, the effects of biological processes on measured signals can be studied in a well controlled manner. To demonstrate this concept, we attempted to investigate how the cellular remodeling of a collagen matrix affected the optical properties extracted from optical coherence tomography (OCT) images of the samples. Tissue-engineered optical phantoms of the vascular system were created by seeding smooth muscle cells in a collagen matrix. Four different optical properties were evaluated by fitting the OCT signal to 2 different models: the sample reflectivity ρ and attenuation parameter μ were extracted from the single scattering model, and the scattering coefficient μ s and root-mean-square scattering angle θ rms were extracted from the extended Huygens-Fresnel model. We found that while contraction of the smooth muscle cells was clearly evident macroscopically, on the microscopic scale very few cells were actually embedded in the collagen. Consequently, no significant difference between the cellular and acellular samples in either set of measured optical properties was observed. We believe that further optimization of our tissue-engineering methods is needed in order to make the histology and biochemistry of the cellular samples sufficiently different from the acellular samples on the microscopic level. Once these methods are optimized, we can better verify whether the optical properties of the cellular and acellular collagen samples differ.

  7. Validation of 3D Code KATRIN For Fast Neutron Fluence Calculation of VVER-1000 Reactor Pressure Vessel by Ex-Vessel Measurements and Surveillance Specimens Results

    Directory of Open Access Journals (Sweden)

    Dzhalandinov A.

    2016-01-01

    Full Text Available Usually the synthesis of two-dimensional and one-dimensional discrete ordinate calculations is used to evaluate neutron fluence on VVER-1000 reactor pressure vessel (RPV for prognosis of radiation embrittlement. But there are some cases when this approach is not applicable. For example the latest projects of VVER-1000 have upgraded surveillance program. Containers with surveillance specimens are located on the inner surface of RPV with fast neutron flux maximum. Therefore, the synthesis approach is not suitable enough for calculation of local disturbance of neutron field in RPV inner surface behind the surveillance specimens because of their complicated and heterogeneous structure. In some cases the VVER-1000 core loading consists of fuel assemblies with different fuel height and the applicability of synthesis approach is also ambiguous for these fuel cycles. Also, the synthesis approach is not enough correct for the neutron fluence estimation at the RPV area above core top. Because of these reasons only the 3D neutron transport codes seem to be satisfactory for calculation of neutron fluence on the VVER-1000 RPV. The direct 3D calculations are also recommended by modern regulations.

  8. Comparison of vessel contrast measured with a scanning-beam digital x-ray system and an image intensifier/television system.

    Science.gov (United States)

    Speidel, M A; Wilfley, B P; Heanue, J A; Betts, T D; Van Lysel, M S

    2001-02-01

    Vessel contrast was measured in the fluoroscopic images produced by a scanning-beam digital x-ray (SBDX) system and an image intensifier/television (II/TV) based system. The SBDX system electronically scans a series of pencil x-ray beams across the patient, each of which is directed at a distant small-area detector array. The reduction in detected scatter achieved with this geometry was expected to provide an increase in image contrast. Vessel contrast was evaluated from images of a phantom containing iodinated tubes. The vessels were inserted into an acrylic stack to provide a patient-mimicking scattering medium. Vessel diameter ranged from 0.3 to 3.1 mm. Images were acquired at 100 kVp with the SBDX and II/TV systems and averaged to reduce x-ray noise. The II/TV system was operated in the 6-in. image intensifier mode with an anti-scatter grid. The increase in contrast in the SBDX images, expressed as a ratio of the measured SBDX and II/TV contrasts, ranged from 1.63 to 1.79 for individual vessels. This agreed well with a prediction of the contrast improvement ratio for this experiment, based on measurements of the scatter fraction, object-plane line spread functions, and consideration of the source spectrum and detector absorption properties. The predicted contrast improvement ratio for SBDX relative to II/TV images was 1.62 to 1.77.

  9. Measuring Economic Freedom: Better Without Size of Government

    NARCIS (Netherlands)

    J.C. Ott (Jan Cornelis)

    2016-01-01

    textabstractThe Heritage Foundation and the Fraser Institute measure economic freedom in nations using indices with ten and five indicators respectively. Eight of the Heritage-indicators and four of the Fraser-indicators are about specific types of institutional quality, like rule of law, the

  10. An innovative method for exosome quantification and size measurement.

    Science.gov (United States)

    Mehdiani, Arash; Maier, Anatol; Pinto, Antonio; Barth, Mareike; Akhyari, Payam; Lichtenberg, Artur

    2015-01-17

    Although the biological importance of exosomes has recently gained an increasing amount of scientific and clinical attention, much is still unknown about their complex pathways, their bioavailability and their diverse functions in health and disease. Current work focuses on the presence and the behavior of exosomes (in vitro as well as in vivo) in the context of different human disorders, especially in the fields of oncology, gynecology and cardiology. Unfortunately, neither a consensus regarding a gold standard for exosome isolation exists, nor is there an agreement on such a method for their quantitative analysis. As there are many methods for the purification of exosomes and also many possibilities for their quantitative and qualitative analysis, it is difficult to determine a combination of methods for the ideal approach. Here, we demonstrate nanoparticle tracking analysis (NTA), a semi-automated method for the characterization of exosomes after isolation from human plasma by ultracentrifugation. The presented results show that this approach for isolation, as well as the determination of the average number and size of exosomes, delivers reproducible and valid data, as confirmed by other methods, such as scanning electron microscopy (SEM).

  11. Velocity Mapping Toolbox (VMT): a processing and visualization suite for moving-vessel ADCP measurements

    Science.gov (United States)

    Jackson, R.; Parsons, D. R.; Czuba, J. A.; Mueller, D. S.; Rhoads, B. L.; Engel, F.; Oberg, K. A.; Best, J. L.; Johnson, K. K.; Riley, J. D.

    2011-12-01

    In addition to their common application to measurement of discharge in rivers, acoustic Doppler current profilers (ADCP) provide valuable hydrodynamic data required for understanding geomorphic and fluvial processes. The increasing use of ADCPs to explore the characteristics of complex natural flows has led to a need for standardized post-processing methods for managing, analyzing, and displaying three-dimensional velocity data. Thus far, no standard analytical technique exists for averaging velocity data from multiple ADCP transects to produce a composite depiction of three-dimensional velocity fields. A new software tool, the Velocity Mapping Toolbox (VMT), is presented herein to address this important need. VMT is a Matlab-based toolbox for processing, analyzing, and displaying velocity data collected along multiple ADCP transects. The software can be used to explore patterns of three-dimensional fluid motion through several methods for calculation of secondary flows and includes capabilities for analyzing the acoustic backscatter and bathymetric data from the ADCP. A user-friendly graphical user interface (GUI) enhances program functionality and provides ready access to two- and three- dimensional plotting functions, allowing rapid display and interrogation of velocity, backscatter, and bathymetry data. This presentation describes the basic processing methods employed by VMT and highlights the capabilities of the toolbox through some example applications.

  12. Velocity Mapping Toolbox (VMT): a processing and visualization suite for moving-vessel ADCP measurements

    Science.gov (United States)

    Parsons, D.R.; Jackson, P.R.; Czuba, J.A.; Engel, F.L.; Rhoads, B.L.; Oberg, K.A.; Best, J.L.; Mueller, D.S.; Johnson, K.K.; Riley, J.D.

    2013-01-01

    The use of acoustic Doppler current profilers (ADCP) for discharge measurements and three-dimensional flow mapping has increased rapidly in recent years and has been primarily driven by advances in acoustic technology and signal processing. Recent research has developed a variety of methods for processing data obtained from a range of ADCP deployments and this paper builds on this progress by describing new software for processing and visualizing ADCP data collected along transects in rivers or other bodies of water. The new utility, the Velocity Mapping Toolbox (VMT), allows rapid processing (vector rotation, projection, averaging and smoothing), visualization (planform and cross-section vector and contouring), and analysis of a range of ADCP-derived datasets. The paper documents the data processing routines in the toolbox and presents a set of diverse examples that demonstrate its capabilities. The toolbox is applicable to the analysis of ADCP data collected in a wide range of aquatic environments and is made available as open-source code along with this publication.

  13. The Measurement Method of Defects of Pressure Vessel by Using Shearography

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Cheol Jung [Chonbuk National University, Chonju (Korea, Republic of)

    1997-07-01

    A new experimental technique has been devised to measure residual stress in ductile materials with a combination of laser speckle pattern interferometry and spot heating. The technique to determine the residual stress is based on the well-known idea that when stressed material is heated, the stress may be relieved to a certain degree depending on the time and temperature of the heat treatment and the stress-strain characteristics of the material. In this study, the ANSYS finite-element computer program was employed to obtain the time and temperature of the heat treatment by the spot heating. We used the optical arrangement composed of the in-plane ESPI to obtain the interference fringe for visualization of displacement parallel to the direction of the observation. This interference fringe pattern is transformed into the phase map, which is the phase information of specimen by using the phase shifting method. Finally, we showed the three dimension plot of the object surface deformations with residual stress. 26 refs., 40 figs. (author)

  14. Neurovascular Network Explorer 1.0: a database of 2-photon single-vessel diameter measurements with MATLAB(®) graphical user interface.

    Science.gov (United States)

    Sridhar, Vishnu B; Tian, Peifang; Dale, Anders M; Devor, Anna; Saisan, Payam A

    2014-01-01

    We present a database client software-Neurovascular Network Explorer 1.0 (NNE 1.0)-that uses MATLAB(®) based Graphical User Interface (GUI) for interaction with a database of 2-photon single-vessel diameter measurements from our previous publication (Tian et al., 2010). These data are of particular interest for modeling the hemodynamic response. NNE 1.0 is downloaded by the user and then runs either as a MATLAB script or as a standalone program on a Windows platform. The GUI allows browsing the database according to parameters specified by the user, simple manipulation and visualization of the retrieved records (such as averaging and peak-normalization), and export of the results. Further, we provide NNE 1.0 source code. With this source code, the user can database their own experimental results, given the appropriate data structure and naming conventions, and thus share their data in a user-friendly format with other investigators. NNE 1.0 provides an example of seamless and low-cost solution for sharing of experimental data by a regular size neuroscience laboratory and may serve as a general template, facilitating dissemination of biological results and accelerating data-driven modeling approaches.

  15. Neurovascular Network Explorer 1.0: a database of 2-photon single-vessel diameter measurements with MATLAB® graphical user interface

    Science.gov (United States)

    Sridhar, Vishnu B.; Tian, Peifang; Dale, Anders M.; Devor, Anna; Saisan, Payam A.

    2014-01-01

    We present a database client software—Neurovascular Network Explorer 1.0 (NNE 1.0)—that uses MATLAB® based Graphical User Interface (GUI) for interaction with a database of 2-photon single-vessel diameter measurements from our previous publication (Tian et al., 2010). These data are of particular interest for modeling the hemodynamic response. NNE 1.0 is downloaded by the user and then runs either as a MATLAB script or as a standalone program on a Windows platform. The GUI allows browsing the database according to parameters specified by the user, simple manipulation and visualization of the retrieved records (such as averaging and peak-normalization), and export of the results. Further, we provide NNE 1.0 source code. With this source code, the user can database their own experimental results, given the appropriate data structure and naming conventions, and thus share their data in a user-friendly format with other investigators. NNE 1.0 provides an example of seamless and low-cost solution for sharing of experimental data by a regular size neuroscience laboratory and may serve as a general template, facilitating dissemination of biological results and accelerating data-driven modeling approaches. PMID:24904401

  16. Small-Angle Neutron Scattering Measurements of Magnetic Cluster Sizes in Magnetic Recording Disks

    Energy Technology Data Exchange (ETDEWEB)

    Toney, Michael F

    2003-06-17

    We describe Small Angle Neutron Scattering measurements of the magnetic cluster size distributions for several longitudinal magnetic recording media. We find that the average magnetic cluster size is slightly larger than the average physical grain size, that there is a broad distribution of cluster sizes, and that the cluster size is inversely correlated to the media signal-to-noise ratio. These results show that intergranular magnetic coupling in these media is small and they provide empirical data for the cluster-size distribution that can be incorporated into models of magnetic recording.

  17. Detailed beam and plasma measurements on the vessel for extraction and source plasma analyses (VESPA) Penning H- ion source

    Science.gov (United States)

    Lawrie, S. R.; Faircloth, D. C.; Letchford, A. P.; Whitehead, M. O.; Wood, T.

    2016-02-01

    A vessel for extraction and source plasma analyses (VESPA) is operational at the Rutherford Appleton Laboratory (RAL). This project supports and guides the overall ion source R&D effort for the ISIS spallation neutron and muon facility at RAL. The VESPA produces 100 mA of pulsed H- beam, but perveance scans indicate that the source is production-limited at extraction voltages above 12 kV unless the arc current is increased. A high resolution optical monochromator is used to measure plasma properties using argon as a diagnostic gas. The atomic hydrogen temperature increases linearly with arc current, up to 2.8 eV for 50 A; whereas the electron temperature has a slight linear decrease toward 2.2 eV. The gas density is 1021 m-3, whilst the electron density is two orders of magnitude lower. Densities follow square root relationships with arc current, with gas density decreasing whilst electron (and hence ion) density increases. Stopping and range of ions in matter calculations prove that operating a high current arc with an argon admixture is extremely difficult because cathode-coated cesium is heavily sputtered by argon.

  18. Research vessels

    Digital Repository Service at National Institute of Oceanography (India)

    Rao, P.S.

    by the research vessels RV Gaveshani and ORV Sagar Kanya are reported. The work carried out by the three charted ships is also recorded. A short note on cruise plans for the study of ferromanganese nodules is added...

  19. Methods for obtaining true particle size distributions from cross section measurements

    Energy Technology Data Exchange (ETDEWEB)

    Lord, Kristina Alyse [Iowa State Univ., Ames, IA (United States)

    2013-01-01

    Sectioning methods are frequently used to measure grain sizes in materials. These methods do not provide accurate grain sizes for two reasons. First, the sizes of features observed on random sections are always smaller than the true sizes of solid spherical shaped objects, as noted by Wicksell [1]. This is the case because the section very rarely passes through the center of solid spherical shaped objects randomly dispersed throughout a material. The sizes of features observed on random sections are inversely related to the distance of the center of the solid object from the section [1]. Second, on a plane section through the solid material, larger sized features are more frequently observed than smaller ones due to the larger probability for a section to come into contact with the larger sized portion of the spheres than the smaller sized portion. As a result, it is necessary to find a method that takes into account these reasons for inaccurate particle size measurements, while providing a correction factor for accurately determining true particle size measurements. I present a method for deducing true grain size distributions from those determined from specimen cross sections, either by measurement of equivalent grain diameters or linear intercepts.

  20. Measuring bubble, drop and particle sizes in multiphase systems with ultrasound

    NARCIS (Netherlands)

    Cents, A.H.G.; Brilman, Derk Willem Frederik; Versteeg, Geert; Wijnstra, P.J.; Wijnstra, P.J.; Regtien, Paulus P.L.

    2004-01-01

    A technique is developed for measurement of bubble, droplet and particle-size distributions in multiphase systems, based on the propagation speed and attenuation of ultrasound. The measurement of the size distribution of the dispersed phase in multiphase systems was desired to analyze the

  1. Measuring Bubble, Drop and Particle Sizes in Multiphase Systems with Ultrasound

    NARCIS (Netherlands)

    Cents, A.H.G.; Brilman, D.W.F.; Versteeg, G.F.; Wijnstra, P.J.; Regtien, P.P.L.

    2004-01-01

    A technique is developed for measurement of bubble, droplet and particle-size distributions in multiphase systems, based on the propagation speed and attenuation of ultrasound. The measurement of the size distribution of the dispersed phase in multiphase systems was desired to analyze the

  2. Simultaneous measurement of size and velocity of small particles in laminar flows

    Science.gov (United States)

    Es-Satte, M.; Pellat-Finet, P.; Schmied, L.; Lesage, A.; Richou, J.

    1996-10-01

    A new laser anemometer gauge is presented here. The velocity and the size of spherical particles are simultaneously measured without uniform illumination and preliminary calibration. The used method is based on Mie's scattering light theory. The device is able to measure the velocity and size of hydrogen bubbles electrolytically produced by a platinum wire immersed in the water flow.

  3. Measurement of air aerosol size during the 2001/2002 harmattan ...

    African Journals Online (AJOL)

    The measurement of air aerosol size during the 2001/2002 harmattan season at Uturu, Nigeria is of interest. Aerosol size distributions were measured making use of a zeiss micrometer which is inserted on the diaphragm inside the eyepiece of Olympus binocular microscope. Dust samples collected by direct deposition ...

  4. A liposome-based size calibration method for measuring microvesicles by flow cytometry.

    Science.gov (United States)

    Simonsen, J B

    2016-01-01

    ESSENTIALS: A gold standard to determine the sizes of microvesicles by flow cytometry is needed. We used fluorescently labeled liposomes to estimate the size of microvesicles with flow cytometry. We suggest that liposomes are more accurate size calibrators than the commonly used polystyrene beads. The liposome-based size calibrators improve the size assessment of microvesicle made with flow cytometry. During the past years, the need for a gold standard to determine the sizes of extracellular vesicles including microvesicles by flow cytometry has been emphasized. This work suggests that artificial vesicles can be used as calibrators to estimate the size of microvesicles from the side scattering (SSC) measured with flow cytometry. We prepared fluorescently labeled liposomes with different maximum sizes defined by the pore size (200, 400, 800, and 1000 nm) of the membrane used for the extrusion. The fluorescence strengths from the largest liposomes pertaining to each pore size enabled us to verify the correlation between the SSC from a liposome and the corresponding size. This study indicates that artificial vesicles are more accurate size calibrators compared to the commonly used polystyrene calibrator beads illustrated by the SSC from 110 nm polystyrene beads corresponds to the scattering from ~400 nm vesicle-like particles. We also show that this method of size assessment based on SSC has a low resolution that is roughly estimated to be between 60 and 200 nm, dependent on the vesicle size. © 2015 International Society on Thrombosis and Haemostasis.

  5. A practical and theoretical definition of very small field size for radiotherapy output factor measurements

    Energy Technology Data Exchange (ETDEWEB)

    Charles, P. H., E-mail: p.charles@qut.edu.au; Crowe, S. B.; Langton, C. M.; Trapp, J. V. [School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology, GPO Box 2434, Brisbane, QLD 4001 (Australia); Cranmer-Sargison, G. [Department of Medical Physics, Saskatchewan Cancer Agency, 20 Campus Dr., Saskatoon, Saskatchewan S7L 3P6, Canada and Academic Unit of Medical Physics, Faculty of Medicine and Health, University of Leeds, 8.001 Worsley Building, Leeds LS2 9JT (United Kingdom); Thwaites, D. I. [Institute of Medical Physics, School of Physics, University of Sydney, NSW 2006 (Australia); Kairn, T. [School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology, GPO Box 2434, Brisbane, QLD 4001, Australia and Premion, The Wesley Medical Centre, Suite 1, 40 Chasely St, Auchenflower, Brisbane, QLD 4066 (Australia); Knight, R. T. [Premion, The Wesley Medical Centre, Suite 1, 40 Chasely St, Auchenflower, Brisbane, QLD 4066 (Australia); Kenny, J. [The Australian Clinical Dosimetry Service, Australian Radiation Protection and Nuclear Safety Agency, 619 Lower Plenty Road, Yallambie, VIC 3085, Australia and Radiation Oncology Queensland, St Andrew' s Toowoomba Hospital, Toowoomba, QLD 4350 (Australia)

    2014-04-15

    Purpose: This work introduces the concept of very small field size. Output factor (OPF) measurements at these field sizes require extremely careful experimental methodology including the measurement of dosimetric field size at the same time as each OPF measurement. Two quantifiable scientific definitions of the threshold of very small field size are presented. Methods: A practical definition was established by quantifying the effect that a 1 mm error in field size or detector position had on OPFs and setting acceptable uncertainties on OPF at 1%. Alternatively, for a theoretical definition of very small field size, the OPFs were separated into additional factors to investigate the specific effects of lateral electronic disequilibrium, photon scatter in the phantom, and source occlusion. The dominant effect was established and formed the basis of a theoretical definition of very small fields. Each factor was obtained using Monte Carlo simulations of a Varian iX linear accelerator for various square field sizes of side length from 4 to 100 mm, using a nominal photon energy of 6 MV. Results: According to the practical definition established in this project, field sizes ≤15 mm were considered to be very small for 6 MV beams for maximal field size uncertainties of 1 mm. If the acceptable uncertainty in the OPF was increased from 1.0% to 2.0%, or field size uncertainties are 0.5 mm, field sizes ≤12 mm were considered to be very small. Lateral electronic disequilibrium in the phantom was the dominant cause of change in OPF at very small field sizes. Thus the theoretical definition of very small field size coincided to the field size at which lateral electronic disequilibrium clearly caused a greater change in OPF than any other effects. This was found to occur at field sizes ≤12 mm. Source occlusion also caused a large change in OPF for field sizes ≤8 mm. Based on the results of this study, field sizes ≤12 mm were considered to be theoretically very small for 6

  6. The usage of Sm-153 as a single particle radiotracer to measure tangential circulation time of granular material in a stirred horizontal vessel

    Energy Technology Data Exchange (ETDEWEB)

    Van Kranenburg, G. [DSM Research, BC-PT, Geleen (Netherlands); Mutsers, S. [DSM Research, PO-PT, Geleen (Netherlands); Konings, J. [DSM Services, MPS-RAS, Geleen (Netherlands)

    2001-07-01

    Within the framework of a research project, carried out at DSM Research, to characterize a horizontal stirred vessel with an axial stirrer, the mean tangential circulation time (TCT) of the granular material was investigated with the aid of a single radioactive particle. Horizontal stirred vessels are frequently used for mixing different types of granular solids, for example fertilizers. The mean tangential circulation time is one of the important parameters that characterize the tangential mixing quality. Unlike most radiotracer experiments, where a huge amount of single particles (molecules) is applied to a process, a single radioactive particle was added to the test-rig. By detecting the passage of the radioactive particle through a narrow detection window a sample of the TCT distribution was gathered. By acquiring data of many passages of the particle the TCT distribution is formed. By means of simple mathematics the mean TCT and its standard deviation ({sigma}) is calculated from the collected samples of the TCT distribution. Moreover the single radioactive particle represents a perfect Dirac-impulse and there is almost no need to correct the gathered data. As radioactive tracer, Sm-153 was used. Radioactive particles were produced by mixing Sm{sub 2}O{sub 3} with plastic and moulding it into thin plates with varying thickness. From these plates grains were punched out with varying diameter (ranging from about 0.25 to 1 mm). The grains were irradiated with neutrons in the research reactor (IRI) of Delft University, The Netherlands to produce an activity ranging from 1 to 10 MBq. During several weeks nearly 100 experiments and TCT determinations were carried out. During the experiments the radioactive particle size, the stirrer geometry, the filling height of the granular material and the stirrer revolution time were varied. The presented radiotracer method to determine the mean tangential circulation time (TCT) and its standard deviation has proven to be

  7. A correction algorithm for particle size distribution measurements made with the forward-scattering spectrometer probe

    Science.gov (United States)

    Lock, James A.; Hovenac, Edward A.

    1989-01-01

    A correction algorithm for evaluating the particle size distribution measurements of atmospheric aerosols obtained with a forward-scattering spectrometer probe (FSSP) is examined. A model based on Poisson statistics is employed to calculate the average diameter and rms width of the particle size distribution. The dead time and coincidence errors in the measured number density are estimated. The model generated data are compared with a Monte Carlo simulation of the FSSP operation. It is observed that the correlation between the actual and measured size distribution is nonlinear. It is noted that the algorithm permits more accurate calculation of the average diameter and rms width of the distribution compared to uncorrected measured quantities.

  8. Big Ship Data: Using vessel measurements to improve estimates of temperature and wind speed on the Great Lakes

    Science.gov (United States)

    Fries, Kevin; Kerkez, Branko

    2017-05-01

    The sheer size of many water systems challenges the ability of in situ sensor networks to resolve spatiotemporal variability of hydrologic processes. New sources of vastly distributed and mobile measurements are, however, emerging to potentially fill these observational gaps. This paper poses the question: How can nontraditional measurements, such as those made by volunteer ship captains, be used to improve hydrometeorological estimates across large surface water systems? We answer this question through the analysis of one of the largest such data sets: an unprecedented collection of one million unique measurements made by ships on the North American Great Lakes from 2006 to 2014. We introduce a flexible probabilistic framework, which can be used to integrate ship measurements, or other sets of irregular point measurements, into contiguous data sets. The performance of this framework is validated through the development of a new ship-based spatial data product of water temperature, air temperature, and wind speed across the Great Lakes. An analysis of the final data product suggests that the availability of measurements across the Great Lakes will continue to play a large role in the confidence with which these large surface water systems can be studied and modeled. We discuss how this general and flexible approach can be applied to similar data sets, and how it will be of use to those seeking to merge large collections of measurements with other sources of data, such as physical models or remotely sensed products.

  9. [Study of the reliability in one dimensional size measurement with digital slit lamp microscope].

    Science.gov (United States)

    Wang, Tao; Qi, Chaoxiu; Li, Qigen; Dong, Lijie; Yang, Jiezheng

    2010-11-01

    To study the reliability of digital slit lamp microscope as a tool for quantitative analysis in one dimensional size measurement. Three single-blinded observers acquired and repeatedly measured the images with a size of 4.00 mm and 10.00 mm on the vernier caliper, which simulatated the human eye pupil and cornea diameter under China-made digital slit lamp microscope in the objective magnification of 4 times, 10 times, 16 times, 25 times, 40 times and 4 times, 10 times, 16 times, respectively. The correctness and precision of measurement were compared. The images with 4 mm size were measured by three investigators and the average values were located between 3.98 to 4.06. For the images with 10.00 mm size, the average values fell within 10.00 ~ 10.04. Measurement results of 4.00 mm images showed, except A4, B25, C16 and C25, significant difference was noted between the measured value and the true value. Regarding measurement results of 10.00 mm iamges indicated, except A10, statistical significance was found between the measured value and the true value. In terms of comparing the results of the same size measured at different magnifications by the same investigator, except for investigators A's measurements of 10.00 mm dimension, the measurement results by all the remaining investigators presented statistical significance at different magnifications. Compared measurements of the same size with different magnifications, measurements of 4.00 mm in 4-fold magnification had no significant difference among the investigators', the remaining results were statistically significant. The coefficient of variation of all measurement results were less than 5%; as magnification increased, the coefficient of variation decreased. The measurement of digital slit lamp microscope in one-dimensional size has good reliability,and should be performed for reliability analysis before used for quantitative analysis to reduce systematic errors.

  10. Three-dimensional computed tomography measurement accuracy of varying Hill-Sachs lesion size.

    Science.gov (United States)

    Ho, Anthony; Kurdziel, Michael D; Koueiter, Denise M; Wiater, J Michael

    2018-02-01

    The glenoid track concept has been proposed to correlate shoulder stability with bone loss. Accurate assessment of Hill-Sachs lesion size preoperatively may affect surgical planning and postoperative outcomes; however, no measurement method has been universally accepted. This study aimed to assess the accuracy and reliability of measuring Hill-Sachs lesion sizes using 3-dimensional (3D) computed tomography (CT). Nine polyurethane humerus bone substitutes were used to create Hill-Sachs lesions of varying sizes with a combination of lesion depth (shallow, intermediate, and deep) and width (small, medium, and large). Specimens were scanned with a clinical CT scanner for size measurements and a micro-CT scanner for measurement of true lesion size. Six evaluators repeated measurements twice in a 2-week interval. Scans were measured by use of 3D CT reconstructions for length, width, and Hill-Sachs interval and with use of 2D CT for depth. The interclass correlation coefficient evaluated interobserver and intraobserver variability and percentage error, and Student t-tests assessed measurement accuracy. Interclass correlation coefficient reliability demonstrated strong agreement for all variables measured (0.856-0.975). Percentage error between measured length and measured depth and the true measurement significantly varied with respect to both lesion depth (P = .003 and P = .005, respectively) and lesion size (P = .049 and P = .004, respectively). The 3D CT imaging is effective and reproducible in determining lesion size. Determination of Hill-Sachs interval width is also reliable when it is applied to the glenoid track concept. Measured values on 3D and 2-dimensional imaging using a conventional CT scanner may slightly underestimate true measurements. Copyright © 2017 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

  11. Repeatability and Reproducibility of Superficial Macular Retinal Vessel Density Measurements Using Optical Coherence Tomography Angiography En Face Images.

    Science.gov (United States)

    Lei, Jianqin; Durbin, Mary K; Shi, Yue; Uji, Akihito; Balasubramanian, Siva; Baghdasaryan, Elmira; Al-Sheikh, Mayss; Sadda, Srinivas R

    2017-10-01

    The repeatability and reproducibility of quantitative metrics from optical coherence tomographic angiography (OCTA) must be assessed before these data can be confidently interpreted in clinical research and practice. To evaluate the repeatability and reproducibility of OCTA-derived retinal vascular quantitative metrics. In this cross-sectional study, 21 healthy volunteers (42 eyes) and 22 patients with retinal disease (22 eyes), including 14 with age-related macular degeneration, 3 with epiretinal membrane, 2 with diabetic retinopathy, 2 with myopic macular degeneration, and 1 with retinal vein occlusion, were enrolled. Participants were recruited from September 1 through November 31, 2016. Each eye underwent 3 repeated scans with 3 instruments for a total of 9 acquisitions. Eyes were randomly assigned to scanning with a 3 × 3-mm or 6 × 6-mm pattern. Eyes were excluded from subsequent analysis if any acquisition had a signal strength of less than 7. Repeatability (defined as the agreement in measurements within a device) and reproducibility (defined as the agreement between devices of the same type) were assessed by intraclass correlation coefficient (ICC) and coefficient of variation. All eyes underwent scanning using 3 separate devices. Vessel length density (VLD) and perfusion density (PD) of the superficial retinal vasculature. A total of 21 healthy volunteers (8 men and 13 women; mean [SD] age, 36 [6] years) and 22 patients with retinal disease (15 men and 7 women; mean [SD] age, 79 [9] years) underwent evaluation. Of these, 40 of 42 normal eyes and 15 of 22 eyes with retinal disease met signal strength criteria and were included in this analysis. The ICC among the 3 consecutive scans ranged from 0.82 to 0.98 for VLD and from 0.83 to 0.95 for PD. The coefficient of variation (CV) ranged from 2.2% to 5.9% for VLD and from 2.4% to 5.9% for PD. For reproducibility, the ICC ranged from 0.62 to 0.95 and the CV was less than 6% in all groups. The agreement

  12. Determining sexual dimorphism in frog measurement data: integration of statistical significance, measurement error, effect size and biological significance

    Directory of Open Access Journals (Sweden)

    Hayek Lee-Ann C.

    2005-01-01

    Full Text Available Several analytic techniques have been used to determine sexual dimorphism in vertebrate morphological measurement data with no emergent consensus on which technique is superior. A further confounding problem for frog data is the existence of considerable measurement error. To determine dimorphism, we examine a single hypothesis (Ho = equal means for two groups (females and males. We demonstrate that frog measurement data meet assumptions for clearly defined statistical hypothesis testing with statistical linear models rather than those of exploratory multivariate techniques such as principal components, correlation or correspondence analysis. In order to distinguish biological from statistical significance of hypotheses, we propose a new protocol that incorporates measurement error and effect size. Measurement error is evaluated with a novel measurement error index. Effect size, widely used in the behavioral sciences and in meta-analysis studies in biology, proves to be the most useful single metric to evaluate whether statistically significant results are biologically meaningful. Definitions for a range of small, medium, and large effect sizes specifically for frog measurement data are provided. Examples with measurement data for species of the frog genus Leptodactylus are presented. The new protocol is recommended not only to evaluate sexual dimorphism for frog data but for any animal measurement data for which the measurement error index and observed or a priori effect sizes can be calculated.

  13. Automatic detection and segmentation of vascular structures in dermoscopy images using a novel vesselness measure based on pixel redness and tubularness

    Science.gov (United States)

    Kharazmi, Pegah; Lui, Harvey; Stoecker, William V.; Lee, Tim

    2015-03-01

    Vascular structures are one of the most important features in the diagnosis and assessment of skin disorders. The presence and clinical appearance of vascular structures in skin lesions is a discriminating factor among different skin diseases. In this paper, we address the problem of segmentation of vascular patterns in dermoscopy images. Our proposed method is composed of three parts. First, based on biological properties of human skin, we decompose the skin to melanin and hemoglobin component using independent component analysis of skin color images. The relative quantities and pure color densities of each component were then estimated. Subsequently, we obtain three reference vectors of the mean RGB values for normal skin, pigmented skin and blood vessels from the hemoglobin component by averaging over 100000 pixels of each group outlined by an expert. Based on the Euclidean distance thresholding, we generate a mask image that extracts the red regions of the skin. Finally, Frangi measure was applied to the extracted red areas to segment the tubular structures. Finally, Otsu's thresholding was applied to segment the vascular structures and get a binary vessel mask image. The algorithm was implemented on a set of 50 dermoscopy images. In order to evaluate the performance of our method, we have artificially extended some of the existing vessels in our dermoscopy data set and evaluated the performance of the algorithm to segment the newly added vessel pixels. A sensitivity of 95% and specificity of 87% were achieved.

  14. Image analysis for measuring the size stratification in sand-gravel laboratory experiments

    NARCIS (Netherlands)

    Orru, C.; Chavarrias Borras, V.; Uijttewaal, W.S.J.; Blom, A.

    2014-01-01

    Measurements of spatial and temporal changes in the grain-size distribution of the bed surface and substrate are crucial to improving the modelling of sediment transport and associated grain-size selective processes. We present three complementary techniques to determine such variations in the

  15. Surfactant phosphatidylcholine half-life and pool size measurements in premature baboons developing bronchopulmonary dysplasia

    NARCIS (Netherlands)

    D.J. Janssen; V.P. Carnielli (Virgilio); P.E. Cogo (Paola); S.R. Seidner; I.H.I. Luijendijk; J.L.D. Wattimena (Josias); A.H. Jobe (Alan); L.J.I. Zimmermann (Luc)

    2002-01-01

    textabstractBecause minimal information is available about surfactant metabolism in bronchopulmonary dysplasia, we measured half-lives and pool sizes of surfactant phosphatidylcholine in very preterm baboons recovering from respiratory distress syndrome and developing

  16. Counter-Propagating Optical Trapping System for Size and Refractive Index Measurement of Microparticles

    National Research Council Canada - National Science Library

    Flynn, Richard A; Shao, Bing; Chachisvilis, Mirianas; Ozkan, Mihrimah; Esener, Sadik C

    2005-01-01

    We propose and demonstrate a novel approach to measure the size and refractive index of microparticles based on two beam optical trapping, where forward scattered light is detected to give information about the particle...

  17. Predicting memory performance in normal ageing using different measures of hippocampal size

    Energy Technology Data Exchange (ETDEWEB)

    Lye, T.C.; Creasey, H.; Kril, J.J. [University of Sydney and Concord Hospital, Centre for Education and Research on Ageing, Sydney, New South Wales (Australia); Grayson, D.A. [University of Sydney, School of Psychology, Sydney (Australia); Piguet, O. [University of Sydney and Concord Hospital, Centre for Education and Research on Ageing, Sydney, New South Wales (Australia); Prince of Wales Medical Research Institute and the University of New South Wales, Sydney (Australia); Bennett, H.P. [Prince of Wales Medical Research Institute and the University of New South Wales, Sydney (Australia); Ridley, L.J. [Concord Hospital, Department of Radiology, Sydney (Australia); Broe, G.A. [Prince of Wales Medical Research Institute and the University of New South Wales, Sydney (Australia); Prince of Wales Hospital, Sydney (Australia)

    2006-02-15

    A number of different methods have been employed to correct hippocampal volumes for individual variation in head size. Researchers have previously used qualitative visual inspection to gauge hippocampal atrophy. The purpose of this study was to determine the best measure(s) of hippocampal size for predicting memory functioning in 102 community-dwelling individuals over 80 years of age. Hippocampal size was estimated using magnetic resonance imaging (MRI) volumetry and qualitative visual assessment. Right and left hippocampal volumes were adjusted by three different estimates of head size: total intracranial volume (TICV), whole-brain volume including ventricles (WB+V) and a more refined measure of whole-brain volume with ventricles extracted (WB). We compared the relative efficacy of these three volumetric adjustment methods and visual ratings of hippocampal size in predicting memory performance using linear regression. All four measures of hippocampal size were significant predictors of memory performance. TICV-adjusted volumes performed most poorly in accounting for variance in memory scores. Hippocampal volumes adjusted by either measure of whole-brain volume performed equally well, although qualitative visual ratings of the hippocampus were at least as effective as the volumetric measures in predicting memory performance in community-dwelling individuals in the ninth or tenth decade of life. (orig.)

  18. LANL Robotic Vessel Scanning

    Energy Technology Data Exchange (ETDEWEB)

    Webber, Nels W. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-11-25

    Los Alamos National Laboratory in J-1 DARHT Operations Group uses 6ft spherical vessels to contain hazardous materials produced in a hydrodynamic experiment. These contaminated vessels must be analyzed by means of a worker entering the vessel to locate, measure, and document every penetration mark on the vessel. If the worker can be replaced by a highly automated robotic system with a high precision scanner, it will eliminate the risks to the worker and provide management with an accurate 3D model of the vessel presenting the existing damage with the flexibility to manipulate the model for better and more in-depth assessment.The project was successful in meeting the primary goal of installing an automated system which scanned a 6ft vessel with an elapsed time of 45 minutes. This robotic system reduces the total time for the original scope of work by 75 minutes and results in excellent data accumulation and transmission to the 3D model imaging program.

  19. Triple therapy with octreotide, galanin, and serotonin reduces the size and blood vessel density and increases apoptosis of a rat colon carcinoma.

    Science.gov (United States)

    El-Salhy, Magdy; Sitohy, Basel; Norrgård, Orjan

    2003-03-28

    A rat colonic adenocarcinoma was implanted subcutaneously in female nude (C57BL/6JBom-nu) mice. After 7 days, the animals were divided into different groups. One group received triple therapy with octreotide, galanin, and serotonin, 10 microg/kg body weight of each, twice daily. The second group served as controls and received only saline solution. Three groups received 10 microg/kg body weight twice daily of octreotide, galanin, or serotonin. The last group consisted of controls that received only saline solution. The treatment lasted for 5 days. The tumour volume, wet weight, and relative volume density of blood vessels were significantly decreased after the triple treatment, as compared to controls. Apoptotic index was significantly increased, but the proliferation index was not affected in the group of mice that received triple therapy. There was no significant difference between controls and mice treated with octreotide, galanin, or serotonin regarding tumour volume or weight. The relative volume density of blood vessels was decreased in tumours treated with galanin, but not with octreotide or serotonin. There was no statistical difference in the proliferation index between controls and animals treated with octreotide, galanin, or serotonin, as compared with controls. Tumour necrosis and increased apoptosis may be responsible for the reduction in the volume and weight of the tumour after triple therapy. Tumour necrosis may be caused by the induction of tumour ischemia due to a reduction in tumour blood flow, which is caused by decreased incidence of tumour-feeding blood vessels, and by constriction of tumour-feeding arterioles. These results are promising and may offer treatment for colon cancer. Copyright 2002 Elsevier Science B.V.

  20. Cuff size influences blood pressure measurement in obese children and adolescents

    DEFF Research Database (Denmark)

    Muhamed, P. K.; Olsen, M. H.; Holm, Jens-Christian

    2016-01-01

    Introduction: Recently, we established that a group ofobese children and adolescents had a higher blood pressure(BP) than a healthy control group. In the present study, weinvestigate whether the higher BP in the obese group wasinfluenced by BP cuff sizes.Methods: A total of 104 obese patients aged...... sizes had a significant impact on BP measurements.Despite the influence of cuff size, multiple regressionanalyses revealed that systolic BP was 68 mmHg higherand diastolic BP 32 mmHg higher in the obese groupthan in the control group. A step function, i.e. a sudden fallin BP, was seen at the point...... of switching from small to mediumcuff size in the control group, which suggests that systolicBP was overestimated when using small cuff size andunderestimated when using medium cuff size in subjectswith an AC near 23 cm.Conclusions: BP was higher in the obese group than inthe control group although BP...

  1. Camera on Vessel: A Camera-Based System to Measure Change in Water Volume in a Drinking Glass

    Directory of Open Access Journals (Sweden)

    Idowu Ayoola

    2015-09-01

    Full Text Available A major problem related to chronic health is patients’ “compliance” with new lifestyle changes, medical prescriptions, recommendations, or restrictions. Heart-failure and hemodialysis patients are usually placed on fluid restrictions due to their hemodynamic status. A holistic approach to managing fluid imbalance will incorporate the monitoring of salt-water intake, body-fluid retention, and fluid excretion in order to provide effective intervention at an early stage. Such an approach creates a need to develop a smart device that can monitor the drinking activities of the patient. This paper employs an empirical approach to infer the real water level in a conically shapped glass and the volume difference due to changes in water level. The method uses a low-resolution miniaturized camera to obtain images using an Arduino microcontroller. The images are processed in MATLAB. Conventional segmentation techniques (such as a Sobel filter to obtain a binary image are applied to extract the level gradient, and an ellipsoidal fitting helps to estimate the size of the cup. The fitting (using least-squares criterion between derived measurements in pixel and the real measurements shows a low covariance between the estimated measurement and the mean. The correlation between the estimated results to ground truth produced a variation of 3% from the mean.

  2. Small-size, high-resolution angular displacement measurement technology based on an imaging detector.

    Science.gov (United States)

    Yu, Hai; Wan, Qiuhua; Lu, Xinran; Du, Yingcai; Yang, Shouwang

    2017-01-20

    It is challenging to design a photoelectric encoder that is small in size while ensuring it has sufficiently high resolution and accuracy. Traditional displacement measurement via the moiré fringe signal does not facilitate high resolution at small grate sizes; photoelectric and digital photo processing can significantly improve the angle measurement resolution over traditional techniques. The primary focus of this paper includes grating displacement coding and decoding, as well as the corresponding high-resolution subdivision and measurement error factors. A small-size absolute photographic encoder was designed (50 mm diameter) that exhibits resolution of 1.24'' (20 bit) with a standard deviation of error of 14.3''. The results presented here may provide a theoretical and technological foundation for further research on small-size, high-resolution photographic rotary encoders.

  3. The use of muscle biopsy in the diagnosis of systemic vasculitis affecting small to medium-sized vessels: a prospective evaluation in Japan.

    Science.gov (United States)

    Nunokawa, T; Yokogawa, N; Shimada, K; Enatsu, K; Sugii, S

    2016-01-01

    The aim of this study was to assess the use of muscle biopsy for histopathological confirmation of small vessel vasculitis (SVV) or medium vessel vasculitis (MVV). Muscle biopsies were performed for all consecutive cases of suspected SVV or MVV seen at Tokyo Metropolitan Tama Medical Centre between February 2012 and May 2014 except those for which a skin or renal biopsy was indicated. Forty-nine patients underwent muscle biopsies. All patients were followed for a minimum of 6 months. Diagnosis of SVV or MVV was made in 35 patients. An unrelated condition was diagnosed in 11 patients and no diagnoses were made in three patients. Of the 35 patients in whom SVV or MVV was diagnosed, positive muscle biopsies were obtained in 20 patients [15 microscopic polyangiitis (MPA), three polyarteritis nodosa (PAN), and two eosinophilic granulomatosis with polyangiitis (EGPA)], while other findings led to the same diagnosis in 15 (seven MPA, four GPA, three PAN, and one rheumatoid vasculitis). The sensitivity of the muscle biopsy was 57% [20/35; 95% confidence interval (CI) 50-57]. Of 13 patients presenting with peripheral neuropathy, the muscle biopsy demonstrated vasculitis in nine patients, with 75% sensitivity (9/12; 95% CI 69-75). There were no complications in the procedure apart from delayed wound healing in one patient. Muscle biopsy is a safe method that offers a high diagnostic yield for SVV or MVV, especially in patients with vasculitic neuropathy.

  4. How to Measure Size of Tubal Ectopic Pregnancy on Ultrasound Scan?

    Science.gov (United States)

    Rajah, K; Goodhart, V; Zamora, K P; Amin, T; Jauniaux, E; Jurkovic, D

    2017-11-16

    To identify the preoperative ultrasound measurements for assessing the size of tubal ectopic pregnancy which correlate best with the findings at surgery. We conducted a prospective study of all women with a conclusive transvaginal ultrasound diagnosis of tubal ectopic pregnancy over a 10-month period. In each case, we measured the total size of the ectopic pregnancy by placing the calipers on the outer edges of the visible trophoblastic tissue. In ectopic pregnancies, presenting with a well-defined gestational sac we also measured the size of coelomic (chorionic) cavity using the inner borders of the trophoblastic ring as the reference points. In women with signs of intraabdominal bleeding, we measured the size of the haematosalpinx and haemoperitoneum. The surgeons were blinded to the ultrasound measurements and they were asked to estimate the size of the ectopic pregnancy and the amount of haemoperitoneum intraoperatively. A total of 105 women were diagnosed with a tubal ectopic pregnancy on ultrasound examination out of which 71/105 (67.6%) were managed surgically. We found a significant (p<0.01) positive correlation between all ultrasound measurements and the size of tubal ectopic pregnancy as reported during surgery. In the absence of a haematosalpinx, the mean total outer diameter of ectopic pregnancy had the highest positive correlation with the size of tubal ectopic at surgery (r=0.65, P<0.001). In cases complicated by haematosalpinx, the mean diameter of the tube was the only variable which correlated significantly (p<0.001) with the estimated size of ectopic pregnancy at surgery. There was a significant (p<0.001) positive association between the amount of haemoperitoneum on ultrasound and the estimated volume of intraperitoneal blood at surgery. The mean size of haematosalpinx and the total outer mean dimeter of ectopic pregnancy on ultrasound correlate better with the surgical findings than the size of coelomic cavity. Our findings show that the standard

  5. The oral mucosal surface and blood vessels.

    Science.gov (United States)

    Naumova, Ella A; Dierkes, Tobias; Sprang, Jürgen; Arnold, Wolfgang H

    2013-03-12

    Detailed information about the size of the oral mucosa is scarce in the literature, and those studies that do exist do not take into account the size of the tongue or the enlargement of the surface by the papillae. Because of the various functions of the oral mucosa in the maintenance of oral health, knowledge of its true size may provide a better understanding of the physiology of the oral cavity and some oral diseases and direct future therapeutic strategies. The aim of this study was to determine the total size of the oral mucosa. Five human adult cadaver heads were cut in the median sagittal plane, and the total area of the oral surface was determined using silicon casts. The surface of the tongue was measured with quantitative profilometry. Photographs of oral blood vessels were taken in different areas of the oral mucosa of adult test subjects using intravital microscopy, and the pictures were compared with vessel casts of the oral mucosal capillaries of a maccaca fasciculrais monkey, which was studied using a scanning electron microscope. The results showed that the dorsal side of the tongue comprises a large proportion of the total oral mucosal surface. The surface area of the epithelium increases moving from anterior to posterior on the tongue, and the number of underlying blood vessels increases proportionally. It can be concluded that the back of the tongue plays an important role in the oral resorption of drugs. The results may be of relevance for the delivery and development of oral drug application.

  6. Reporting unit size and measurement uncertainty: current Australian practice in clinical chemistry and haematology.

    Science.gov (United States)

    Hawkins, Robert C; Badrick, Tony

    2015-08-01

    In this study we aimed to compare the reporting unit size used by Australian laboratories for routine chemistry and haematology tests to the unit size used by learned authorities and in standard laboratory textbooks and to the justified unit size based on measurement uncertainty (MU) estimates from quality assurance program data. MU was determined from Royal College of Pathologists of Australasia (RCPA) - Australasian Association of Clinical Biochemists (AACB) and RCPA Haematology Quality Assurance Program survey reports. The reporting unit size implicitly suggested in authoritative textbooks, the RCPA Manual, and the General Serum Chemistry program itself was noted. We also used published data on Australian laboratory practices.The best performing laboratories could justify their chemistry unit size for 55% of analytes while comparable figures for the 50% and 90% laboratories were 14% and 8%, respectively. Reporting unit size was justifiable for all laboratories for red cell count, >50% for haemoglobin but only the top 10% for haematocrit. Few, if any, could justify their mean cell volume (MCV) and mean cell haemoglobin concentration (MCHC) reporting unit sizes.The reporting unit size used by many laboratories is not justified by present analytical performance. Using MU estimates to determine the reporting interval for quantitative laboratory results ensures reporting practices match local analytical performance and recognises the inherent error of the measurement process.

  7. Grain size of loess and paleosol samples: what are we measuring?

    Science.gov (United States)

    Varga, György; Kovács, János; Szalai, Zoltán; Újvári, Gábor

    2017-04-01

    Particle size falling into a particularly narrow range is among the most important properties of windblown mineral dust deposits. Therefore, various aspects of aeolian sedimentation and post-depositional alterations can be reconstructed only from precise grain size data. Present study is aimed at (1) reviewing grain size data obtained from different measurements, (2) discussing the major reasons for disagreements between data obtained by frequently applied particle sizing techniques, and (3) assesses the importance of particle shape in particle sizing. Grain size data of terrestrial aeolian dust deposits (loess and paleosoil) were determined by laser scattering instruments (Fritsch Analysette 22 Microtec Plus, Horiba Partica La-950 v2 and Malvern Mastersizer 3000 with a Hydro Lv unit), while particles size and shape distributions were acquired by Malvern Morphologi G3-ID. Laser scattering results reveal that the optical parameter settings of the measurements have significant effects on the grain size distributions, especially for the fine-grained fractions (camera. However, this is only one outcome of infinite possible projections of a three-dimensional object and it cannot be regarded as a representative one. The third (height) dimension of the particles remains unknown, so the volume-based weightings are fairly dubious in the case of platy particles. Support of the National Research, Development and Innovation Office (Hungary) under contract NKFI 120620 is gratefully acknowledged. It was additionally supported (for G. Varga) by the Bolyai János Research Scholarship of the Hungarian Academy of Sciences.

  8. Cobble cam: Grain-size measurements of sand to boulder from digital photographs and autocorrelation analyses

    Science.gov (United States)

    Warrick, J.A.; Rubin, D.M.; Ruggiero, P.; Harney, J.N.; Draut, A.E.; Buscombe, D.

    2009-01-01

    A new application of the autocorrelation grain size analysis technique for mixed to coarse sediment settings has been investigated. Photographs of sand- to boulder-sized sediment along the Elwha River delta beach were taken from approximately 1??2 m above the ground surface, and detailed grain size measurements were made from 32 of these sites for calibration and validation. Digital photographs were found to provide accurate estimates of the long and intermediate axes of the surface sediment (r2 > 0??98), but poor estimates of the short axes (r2 = 0??68), suggesting that these short axes were naturally oriented in the vertical dimension. The autocorrelation method was successfully applied resulting in total irreducible error of 14% over a range of mean grain sizes of 1 to 200 mm. Compared with reported edge and object-detection results, it is noted that the autocorrelation method presented here has lower error and can be applied to a much broader range of mean grain sizes without altering the physical set-up of the camera (~200-fold versus ~6-fold). The approach is considerably less sensitive to lighting conditions than object-detection methods, although autocorrelation estimates do improve when measures are taken to shade sediments from direct sunlight. The effects of wet and dry conditions are also evaluated and discussed. The technique provides an estimate of grain size sorting from the easily calculated autocorrelation standard error, which is correlated with the graphical standard deviation at an r2 of 0??69. The technique is transferable to other sites when calibrated with linear corrections based on photo-based measurements, as shown by excellent grain-size analysis results (r2 = 0??97, irreducible error = 16%) from samples from the mixed grain size beaches of Kachemak Bay, Alaska. Thus, a method has been developed to measure mean grain size and sorting properties of coarse sediments. ?? 2009 John Wiley & Sons, Ltd.

  9. In situ exhaust cloud measurements. [particle size distribution and cloud physics of rocket exhaust clouds

    Science.gov (United States)

    Wornom, D.

    1980-01-01

    Airborne in situ exhaust cloud measurements were conducted to obtain definitions of cloud particle size range, Cl2 content, and HCl partitioning. Particle size distribution data and Cl2 measurements were made during the May, August, and September 1977 Titan launches. The measurements of three basic effluents - HCl, NO sub X, and particles - against minutes after launch are plotted. The maximum observed HCl concentration to the maximum Cl2 concentration are compared and the ratios of the Cl2 to the HCl is calculated.

  10. A uniform measurement expression for cross method comparison of nanoparticle aggregate size distributions

    DEFF Research Database (Denmark)

    Dudkiewicz, Agnieszka; Wagner, Stephan; Lehner, Angela

    2015-01-01

    plasma mass spectrometry detection (AF4-ICP-MS). Transformed size distributions are then compared between the methods and conclusions drawn on methods’ measurement accuracy, limits of detection and quantification related to the synthetic amorphous silca’s size. Two out of the six tested methods (GEMMA...... and AF4-ICP-MS) cross validate the MED distributions between each other, providing a true measurement. The measurement accuracy of other four techniques is shown to be compromised either by the high limit of detection and quantification (CLS, NTA, Wet-SEM) or the sample preparation that is biased...

  11. The determinants of fishing vessel accident severity.

    Science.gov (United States)

    Jin, Di

    2014-05-01

    The study examines the determinants of fishing vessel accident severity in the Northeastern United States using vessel accident data from the U.S. Coast Guard for 2001-2008. Vessel damage and crew injury severity equations were estimated separately utilizing the ordered probit model. The results suggest that fishing vessel accident severity is significantly affected by several types of accidents. Vessel damage severity is positively associated with loss of stability, sinking, daytime wind speed, vessel age, and distance to shore. Vessel damage severity is negatively associated with vessel size and daytime sea level pressure. Crew injury severity is also positively related to the loss of vessel stability and sinking. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. A rapid method of fruit cell isolation for cell size and shape measurements

    Directory of Open Access Journals (Sweden)

    Johnston Jason W

    2009-04-01

    Full Text Available Abstract Background Cell size is a structural component of fleshy fruit, contributing to important traits such as fruit size and texture. There are currently a number of methods for measuring cell size; most rely either on tissue sectioning or digestion of the tissue with cell wall degrading enzymes or chemicals to release single cells. Neither of these approaches is ideal for assaying large fruit numbers as both require a considerable time to prepare the tissue, with current methods of cell wall digestions taking 24 to 48 hours. Additionally, sectioning can lead to a measurement of a plane that does not represent the widest point of the cell. Results To develop a more rapid way of measuring fruit cell size we have developed a protocol that solubilises pectin in the middle lamella of the plant cell wall releasing single cells into a buffered solution. Gently boiling small fruit samples in a 0.05 M Na2CO3 solution, osmotically balanced with 0.3 M mannitol, produced good cell separation with little cellular damage in less than 30 minutes. The advantage of combining a chemical treatment with boiling is that the cells are rapidly killed. This stopped cell shape changes that could potentially occur during separation. With this method both the rounded and angular cells of the apple cultivars SciRos 'Pacific Rose' and SciFresh 'Jazz'™ were observed in the separated cells. Using this technique, an in-depth analysis was performed measuring cell size from 5 different apple cultivars. Cell size was measured using the public domain ImageJ software. For each cultivar a minimum of 1000 cells were measured and it was found that each cultivar displayed a different distribution of cell size. Cell size within cultivars was similar and there was no correlation between flesh firmness and cell size. This protocol was tested on tissue from other fleshy fruit including tomato, rock melon and kiwifruit. It was found that good cell separation was achieved with flesh

  13. Accurate measurement of nanoparticle charge, number and size with the ELPI+{sup TM} instrument

    Energy Technology Data Exchange (ETDEWEB)

    Lamminen, Erkki, E-mail: erkki.lamminen@dekati.fi [Osuusmyllynkatu 13, 33700 Tampere (Finland)

    2011-07-06

    Nanoparticle characterization is mainly carried out by microscopy techniques and measurements of size and concentration. However to be able to comprehensively understand the behavior of the aerosol, information on particle charge level is critical. Particle charge has a major effect on the coagulation, deposition and transport as well as on the health effects of the particles. While aged aerosols generally are mainly neutral in terms of charge, freshly generated or resuspended particles can have high charge levels that vary depending on the size, material and generation method of the particles. Charging processes for particles are problematic as they are usually both time dependent and material dependent with sudden changes in magnitude. This makes the charge of a particle nearly impossible to predict without detailed studies and direct measurements. ELPI+{sup TM} instrument is a completely new aerosol measurement instrument based on the widely used Electrical Low Pressure Impactor (ELPI) technique. ELPI+{sup TM} measures particle concentration and size in a wide size range from 6nm to 10{mu}m in real-time. The operation is based on first charging the particles in a corona charger and then size segregating them in a cascade impactor where all impactor stages are electrically insulated. With the ELPI+{sup TM} instrument it is possible to measure not only the particle size and concentration in real-time, but also the charge distribution of the particles. As the particle size classification is made with an impactor, the measured particles can be subsequently analyzed if needed with a suitable technique.

  14. Accurate measurement of nanoparticle charge, number and size with the ELPI+™ instrument

    Science.gov (United States)

    Lamminen, Erkki

    2011-07-01

    Nanoparticle characterization is mainly carried out by microscopy techniques and measurements of size and concentration. However to be able to comprehensively understand the behavior of the aerosol, information on particle charge level is critical. Particle charge has a major effect on the coagulation, deposition and transport as well as on the health effects of the particles. While aged aerosols generally are mainly neutral in terms of charge, freshly generated or resuspended particles can have high charge levels that vary depending on the size, material and generation method of the particles. Charging processes for particles are problematic as they are usually both time dependent and material dependent with sudden changes in magnitude. This makes the charge of a particle nearly impossible to predict without detailed studies and direct measurements. ELPI+™ instrument is a completely new aerosol measurement instrument based on the widely used Electrical Low Pressure Impactor (ELPI) technique. ELPI+™ measures particle concentration and size in a wide size range from 6nm to 10μm in real-time. The operation is based on first charging the particles in a corona charger and then size segregating them in a cascade impactor where all impactor stages are electrically insulated. With the ELPI+™ instrument it is possible to measure not only the particle size and concentration in real-time, but also the charge distribution of the particles. As the particle size classification is made with an impactor, the measured particles can be subsequently analyzed if needed with a suitable technique.

  15. Development of a simplified optical technique for the simultaneous measurement of particle size distribution and velocity

    Science.gov (United States)

    Smith, J. L.

    1983-01-01

    Existing techniques were surveyed, an experimental procedure was developed, a laboratory test model was fabricated, limited data were recovered for proof of principle, and the relationship between particle size distribution and amplitude measurements was illustrated in an effort to develop a low cost, simplified optical technique for measuring particle size distributions and velocities in fluidized bed combustors and gasifiers. A He-Ne laser illuminated Rochi Rulings (range 10 to 500 lines per inch). Various samples of known particle size distributions were passed through the fringe pattern produced by the rulings. A photomultiplier tube converted light from the fringe volume to an electrical signal which was recorded using an oscilloscope and camera. The signal amplitudes were correlated against the known particle size distributions. The correlation holds true for various samples.

  16. Electrochemical Size Measurement and Characterization of Electrodeposited Platinum Nanoparticles at Nanometer Resolution with Scanning Electrochemical Microscopy.

    Science.gov (United States)

    Ma, Wei; Hu, Keke; Chen, QianJin; Zhou, Min; Mirkin, Michael V; Bard, Allen J

    2017-07-12

    The properties of nanoparticles (NPs) are determined by their size and geometric structures. A reliable determination of NP dimension is critical for understanding their physical and chemical properties, but sizing ultrasmall particles on the order of nanometer (nm) scale in the solution is still challenging. Here, we report the size measurement of PtNP at nanometer resolution by in situ scanning electrochemical microscopy (SECM), performed with the electrochemical generation and removal of H2 bubble at a reasonably small distance between tip and substrate electrodes in 200 or 500 mM HClO4 solution. A series of different PtNPs or nanoclusters were electrodeposited and in situ measured in the solution, proving the concept of sizing ultrasmall particles using tip generation/substrate collection mode of SECM. This technique could be also used for investigations of other supported ultrasmall metal nanocluster systems.

  17. Small-sized reverberation chamber for the measurement of sound absorption

    Directory of Open Access Journals (Sweden)

    R. del Rey

    2017-09-01

    Full Text Available This paper presents the design, construction, calibration and automation of a reverberation chamber for small samples. A balance has been sought between reducing sample size, to reduce the manufacturing costs of materials, and finding the appropriate volume of the chamber, to obtain reliable values at high and mid frequencies. The small-sized reverberation chamber, that was built, has a volume of 1.12 m3 and allows for the testing of samples of 0.3 m2. By using diffusers, to improve the diffusion degree, and automating measurements, we were able to improve the reliability of the results, thus reducing test errors. Several comparison studies of the measurements of the small-sized reverberation chamber and the standardised reverberation chamber are shown, and a good degree of adjustment can be seen between them, within the range of valid frequencies. This paper presents a small laboratory for comparing samples and making decisions before the manufacturing of larger sizes.

  18. Measurement of Bubble Size Distribution Based on Acoustic Propagation in Bubbly Medium

    Science.gov (United States)

    Wu, Xiongjun; Hsiao, Chao-Tsung; Choi, Jin-Keun; Chahine, Georges

    2013-03-01

    Acoustic properties are strongly affected by bubble size distribution in a bubbly medium. Measurement of the acoustic transmission becomes increasingly difficulty as the void fraction of the bubbly medium increases due to strong attenuation, while acoustic reflection can be measured more easily with increasing void fraction. The ABS ACOUSTIC BUBBLE SPECTROMETER®\\copyright, an instrument for bubble size measurement that is under development tries to take full advantage of the properties of acoustic propagation in bubbly media to extract bubble size distribution. Properties of both acoustic transmission and reflection in the bubbly medium from a range of short single-frequency bursts of acoustic waves at different frequencies are measured in an effort to deduce the bubble size distribution. With the combination of both acoustic transmission and reflection, assisted with validations from photography, the ABS ACOUSTIC BUBBLE SPECTROMETER®\\copyright has the potential to measure bubble size distributions in a wider void fraction range. This work was sponsored by Department of Energy SBIR program

  19. A novel methodology to measure methane bubble sizes in the water column

    Science.gov (United States)

    Hemond, H.; Delwiche, K.; Senft-Grupp, S.; Manganello, T.

    2014-12-01

    The fate of methane ebullition from lake sediments is dependent on initial bubble size. Rising bubbles are subject to dissolution, reducing the fraction of methane that ultimately enters the atmosphere while increasing concentrations of aqueous methane. Smaller bubbles not only rise more slowly, but dissolve more rapidly larger bubbles. Thus, understanding methane bubble size distributions in the water column is critical to predicting atmospheric methane emissions from ebullition. However, current methods of measuring methane bubble sizes in-situ are resource-intensive, typically requiring divers, video equipment, sonar, or hydroacoustic instruments. The complexity and cost of these techniques points to the strong need for a simple, autonomous device that can measure bubble size distributions and be deployed unattended over long periods of time. We describe a bubble sizing device that can be moored in the subsurface and can intercept and measure the size of bubbles as they rise. The instrument uses a novel optical measurement technique with infrared LEDs and IR-sensitive photodetectors combined with a custom-designed printed circuit board. An on-board microcomputer handles raw optical signals and stores the relevant information needed to calculate bubble volume. The electronics are housed within a pressure case fabricated from standard PVC fittings and are powered by size C alkaline batteries. The bill of materials cost is less than $200, allowing us to deploy multiple sensors at various locations within Upper Mystic Lake, MA. This novel device will provide information on how methane bubble sizes may vary both spatially and temporally. We present data from tests under controlled laboratory conditions and from deployments in Upper Mystic Lake.

  20. Geometric measures of multipartite entanglement in finite-size spin chains

    Energy Technology Data Exchange (ETDEWEB)

    Blasone, M; Dell' Anno, F; De Siena, S; Giampaolo, S M; Illuminati, F, E-mail: illuminati@sa.infn.i [Dipartimento di Matematica e Informatica, Universita degli Studi di Salerno, Via Ponte don Melillo, I-84084 Fisciano (Italy)

    2010-09-01

    We investigate the behaviour of multipartite entanglement in finite-size quantum spin systems, resorting to a hierarchy of geometric measures of multipartite entanglement recently introduced in the literature. In particular, we investigate the ground-state entanglement in the XY model defined on finite chains of N sites with periodic boundary conditions. We analyse the behaviour of the geometric measures of (N- 1)-partite and (N/2)-partite entanglement and compare them with the Wei-Goldbart geometric measure of global entanglement.

  1. Retrieval of snow albedo and grain size using reflectance measurements in Himalayan basin

    OpenAIRE

    H. S. Negi; A. Kokhanovsky

    2010-01-01

    In the present paper spectral reflectance measurements of Himalayan seasonal snow were carried out and analysed to retrieve the snow albedo and effective grain size. The asymptotic radiative transfer (ART) theory was applied to retrieve the plane and spherical albedo. The retrieved plane albedo was compared with the measured spectral albedo and a good agreement was observed with ±10% measured error accuracy. Retrieved integrated albedo was found within ±6% difference with ground observed broa...

  2. Particle Size Distributions Measured in the Stratospheric Plumes of Three Rockets During the ACCENT Missions

    Science.gov (United States)

    Wiedinmyer, C.; Brock, C. A.; Reeves, J. M.; Ross, M. N.; Schmid, O.; Toohey, D.; Wilson, J. C.

    2001-12-01

    The global impact of particles emitted by rocket engines on stratospheric ozone is not well understood, mainly due to the lack of comprehensive in situ measurements of the size distributions of these emitted particles. During the Atmospheric Chemistry of Combustion Emissions Near the Tropopause (ACCENT) missions in 1999, the NASA WB-57F aircraft carried the University of Denver N-MASS and FCAS instruments into the stratospheric plumes from three rockets. Size distributions of particles with diameters from 4 to approximately 2000 nm were calculated from the instrument measurements using numerical inversion techniques. The data have been averaged over 30-second intervals. The particle size distributions observed in all of the rocket plumes included a dominant mode near 60 nm diameter, probably composed of alumina particles. A smaller mode at approximately 25 nm, possibly composed of soot particles, was seen in only the plumes of rockets that used liquid oxygen and kerosene as a propellant. Aircraft exhaust emitted by the WB-57F was also sampled; the size distributions within these plumes are consistent with prior measurements in aircraft plumes. The size distributions for all rocket intercepts have been fitted to bimodal, lognormal distributions to provide input for global models of the stratosphere. Our data suggest that previous estimates of the solid rocket motor alumina size distributions may underestimate the alumina surface area emission index, and so underestimate the particle surface area available for heterogeneous chlorine activation reactions in the global stratosphere.

  3. Americium behaviour in plastic vessels

    Energy Technology Data Exchange (ETDEWEB)

    Legarda, F.; Herranz, M. [Departamento de Ingenieria Nuclear y Mecanica de Fluidos, Escuela Tecnica Superior de Ingenieria de Bilbao, Universidad del Pais Vasco (UPV/EHU), Alameda de Urquijo s/n, 48013 Bilbao (Spain); Idoeta, R., E-mail: raquel.idoeta@ehu.e [Departamento de Ingenieria Nuclear y Mecanica de Fluidos, Escuela Tecnica Superior de Ingenieria de Bilbao, Universidad del Pais Vasco (UPV/EHU), Alameda de Urquijo s/n, 48013 Bilbao (Spain); Abelairas, A. [Departamento de Ingenieria Nuclear y Mecanica de Fluidos, Escuela Tecnica Superior de Ingenieria de Bilbao, Universidad del Pais Vasco (UPV/EHU), Alameda de Urquijo s/n, 48013 Bilbao (Spain)

    2010-07-15

    The adsorption of {sup 241}Am dissolved in water in different plastic storage vessels was determined. Three different plastics were investigated with natural and distilled waters and the retention of {sup 241}Am by these plastics was studied. The same was done by varying vessel agitation time, vessel agitation speed, surface/volume ratio of water in the vessels and water pH. Adsorptions were measured to be between 0% and 70%. The adsorption of {sup 241}Am is minimized with no water agitation, with PET or PVC plastics, and by water acidification.

  4. Emittance reconstruction from measured beam sizes in ATF2 and perspectives for ILC

    Energy Technology Data Exchange (ETDEWEB)

    Faus-Golfe, A. [Instituto de Física Corpuscular (CSIC-UV) (Spain); Laboratoire de L' Accélérateur Linéaire (LAL) (France); Navarro, J.; Fuster Martinez, N. [Instituto de Física Corpuscular (CSIC-UV) (Spain); Resta Lopez, J. [Cockcroft Institute and University of Liverpool (United Kingdom); Giner Navarro, J. [Instituto de Física Corpuscular (CSIC-UV) (Spain); European Organization for Nuclear Research CERN (Switzerland)

    2016-05-21

    The projected emittance (2D) and the intrinsic emittance (4D) reconstruction method by using the beam size measurements at different locations is analyzed in order to study analytically the conditions of solvability of the systems of equations involved in this process. Some conditions are deduced and discussed, and general guidelines about the locations of the measurement stations have been obtained to avoid unphysical results. The special case of the multi-Optical Transition Radiation system (m-OTR), made of four measurement stations, in the Extraction Line (EXT) of Accelerator Test Facility 2 (ATF2) has been simulated in much detail and compared with measurements. Finally a feasibility study of a multi-station system for fast transverse beam size measurement, emittance reconstruction and coupling correction in the Ring to Main Linac (RTML) of International Linear Collider (ILC) Diagnostic sections of the RTML has been discussed in detail.

  5. A simple algorithm for measuring particle size distributions on an uneven background from TEM images

    DEFF Research Database (Denmark)

    Gontard, Lionel Cervera; Ozkaya, Dogan; Dunin-Borkowski, Rafal E.

    2011-01-01

    Nanoparticles have a wide range of applications in science and technology. Their sizes are often measured using transmission electron microscopy (TEM) or X-ray diffraction. Here, we describe a simple computer algorithm for measuring particle size distributions from TEM images in the presence...... of an uneven background. The approach is based on adaptive thresholding, making use of local threshold values that change with spatial coordinate. The algorithm allows particles to be detected and characterized with greater accuracy than using more conventional methods, in which a global threshold is used. Its...

  6. Electrode size and boundary condition independent measurement of the effective piezoelectric coefficient of thin films

    Directory of Open Access Journals (Sweden)

    M. Stewart

    2015-02-01

    Full Text Available The determination of the piezoelectric coefficient of thin films using interferometry is hindered by bending contributions. Using finite element analysis (FEA simulations, we show that the Lefki and Dormans approximations using either single or double-beam measurements cannot be used with finite top electrode sizes. We introduce a novel method for characterising piezoelectric thin films which uses a differential measurement over the discontinuity at the electrode edge as an internal reference, thereby eliminating bending contributions. This step height is shown to be electrode size and boundary condition independent. An analytical expression is derived which gives good agreement with FEA predictions of the step height.

  7. A novel in situ measurement method of bubble sizes in bioreactors using a high speed camera

    DEFF Research Database (Denmark)

    Bach, Christian; Albæk, Mads Orla; Krühne, Ulrich

    to bioreactors at different conditions in terms of power input, gas flow rate and viscosity. This in situ measurement illustrates the effect of process conditions on the size of the bubbles. The information on bubble sizes at different conditions is a valuable input to mechanistic models regarding gas...... conditions affect the mass transfer rate, and hence a tool for identifying them individually is required. Available correlations for these variables are predominantly system dependent and therefore not necessarily valid in the process of interest. Currently available measurement techniques to identify bubble...

  8. A combined Settling Tube-Photometer for rapid measurement of effective sediment particle size

    Science.gov (United States)

    Kuhn, Nikolaus J.; Kuhn, Brigitte; Rüegg, Hans-Rudolf; Zimmermann, Lukas

    2017-04-01

    Sediment and its movement in water is commonly described based on the size distribution of the mineral particles forming the sediment. While this approach works for coarse sand, pebbles and gravel, smaller particles often form aggregates, creating material of larger diameters than the mineral grain size distribution indicates, but lower densities than often assumed 2.65 g cm-3 of quartz. The measurement of the actual size and density of such aggregated sediment is difficult. For the assessment of sediment movement an effective particle size for the use in mathematical can be derived based on the settling velocity of sediment. Settling velocity of commonly measured in settling tubes which fractionate the sample in settling velocity classes by sampling material at the base in selected time intervals. This process takes up to several hours, requires a laboratory setting and carries the risk of either destruction of aggregates during transport or coagulation while sitting in rather still water. Measuring the velocity of settling particles in situ, or at least a rapidly after collection, could avoids these problems. In this study, a settling tube equipped with four photometers used to measure the darkening of a settling particle cloud is presented and the potential to improve the measurement of settling velocities are discussed.

  9. The international food unit: a new measurement aid that can improve portion size estimation.

    Science.gov (United States)

    Bucher, T; Weltert, M; Rollo, M E; Smith, S P; Jia, W; Collins, C E; Sun, M

    2017-09-12

    Portion size education tools, aids and interventions can be effective in helping prevent weight gain. However consumers have difficulties in estimating food portion sizes and are confused by inconsistencies in measurement units and terminologies currently used. Visual cues are an important mediator of portion size estimation, but standardized measurement units are required. In the current study, we present a new food volume estimation tool and test the ability of young adults to accurately quantify food volumes. The International Food Unit™ (IFU™) is a 4x4x4 cm cube (64cm(3)), subdivided into eight 2 cm sub-cubes for estimating smaller food volumes. Compared with currently used measures such as cups and spoons, the IFU™ standardizes estimation of food volumes with metric measures. The IFU™ design is based on binary dimensional increments and the cubic shape facilitates portion size education and training, memory and recall, and computer processing which is binary in nature. The performance of the IFU™ was tested in a randomized between-subject experiment (n = 128 adults, 66 men) that estimated volumes of 17 foods using four methods; the IFU™ cube, a deformable modelling clay cube, a household measuring cup or no aid (weight estimation). Estimation errors were compared between groups using Kruskall-Wallis tests and post-hoc comparisons. Estimation errors differed significantly between groups (H(3) = 28.48, p food portions and similar for 5 food portions. Weight estimation was associated with a median error of 23.5% (IQR = 79.8). The IFU™ improves volume estimation accuracy compared to other methods. The cubic shape was perceived as favourable, with subdivision and multiplication facilitating volume estimation. Further studies should investigate whether the IFU™ can facilitate portion size training and whether portion size education using the IFU™ is effective and sustainable without the aid. A 3-dimensional IFU™ could serve as a reference

  10. Synthetic measure of association to determinate the business size of SMEs

    Directory of Open Access Journals (Sweden)

    Gerardo Reyes Ruiz

    2016-10-01

    Full Text Available SMEs play a major role in today’s economy all contributing both to the generation of wealth and the creation of jobs, so it makes sense this study to show the level of association between financial ratios to construct a synthetic measure that explains the size business for a sample of Catalan SMEs. To do three techniques of data analysis were used; Technical Cluster was first used in two phases (CDF to define a correspondence with firm size, after obtaining the optimal number of clusters was estimated through a fuzzy analysis clustering, business size most likely for each company. The results yield evidence that the initial groups should not be three but two for 12,658 SMEs in Catalonia where a large proportion of small businesses called present financial information that might well classify as medium enterprises. The study provides a different way to consider business size.

  11. Sample Size for Assessing Agreement between Two Methods of Measurement by Bland-Altman Method.

    Science.gov (United States)

    Lu, Meng-Jie; Zhong, Wei-Hua; Liu, Yu-Xiu; Miao, Hua-Zhang; Li, Yong-Chang; Ji, Mu-Huo

    2016-11-01

    The Bland-Altman method has been widely used for assessing agreement between two methods of measurement. However, it remains unsolved about sample size estimation. We propose a new method of sample size estimation for Bland-Altman agreement assessment. According to the Bland-Altman method, the conclusion on agreement is made based on the width of the confidence interval for LOAs (limits of agreement) in comparison to predefined clinical agreement limit. Under the theory of statistical inference, the formulae of sample size estimation are derived, which depended on the pre-determined level of α, β, the mean and the standard deviation of differences between two measurements, and the predefined limits. With this new method, the sample sizes are calculated under different parameter settings which occur frequently in method comparison studies, and Monte-Carlo simulation is used to obtain the corresponding powers. The results of Monte-Carlo simulation showed that the achieved powers could coincide with the pre-determined level of powers, thus validating the correctness of the method. The method of sample size estimation can be applied in the Bland-Altman method to assess agreement between two methods of measurement.

  12. Tooth size in patients with supernumerary teeth and a control group measured by image analysis system.

    Science.gov (United States)

    Khalaf, K; Robinson, D L; Elcock, C; Smith, R N; Brook, A H

    2005-02-01

    The aim of this study was to compare tooth size measurements between patients with supernumerary teeth and a control group. The supernumerary group consisted of 56 subjects (21 females and 35 males) and the control group of 40 subjects (20 females and 20 males). All available permanent teeth on the dental casts were imaged and measured from both buccal and occlusal views using an image analysis system. Mesio-distal, bucco-lingual or occluso-gingival dimensions, area and perimeter were measured from each view. Supernumerary tooth patients tended to have larger tooth size measurements for almost all variables than controls. Significant differences (psupernumerary teeth being a complex dental anomaly with a multifactorial aetiology in which both genetic and environmental factors are important. There is some evidence of a local effect with greater differences in tooth dimension adjacent to the site of the supernumeraries.

  13. Flow microfluorometric and light-scatter measurement of nuclear and cytoplasmic size in mammalian cells

    Energy Technology Data Exchange (ETDEWEB)

    Steinkamp, J.A.; Hansen, K.M.; Crissman, H.A.

    1976-01-01

    A technique for rapid measurement of nuclear and cytoplasmic size relationships in mammalian cell populations has been developed. Based on fluorescence staining of either the nucleus alone or in combination with the cytoplasm using two-color fluorescence methods, this technique permits the simultaneous determination of nuclear and cytoplasmic diameters from fluorescence and light-scatter measurements. Cells stained in liquid suspension pass through a flow chamber at a constant velocity, intersecting a laser beam which excites cell fluorescence and causes light scatter. Depending upon which analysis procedure is used, optical sensors measure nuclear fluorescence and light scatter (whole cell size) or two-color nuclear and cytoplasmic fluorescence from individual cells crossing the laser beam. The time durations of signals generated by the nucleus and cytoplasm are converted electronically into signals proportional to the respective diameters and are displayed as frequency distribution histograms. Illustrative examples of measurements on uniform microspheres, cultured mammalian cells and human exfoliated gynecologic cells are presented.

  14. The measurement of aerosol size distributions (AMAD) in buildings on BNFL`s Sellafield site

    Energy Technology Data Exchange (ETDEWEB)

    Kelso, S.M.; Wraight, J.C. [British Nuclear Fuels plc, Sellafield (United Kingdom)

    1996-07-01

    Cascade centripeters were used to make measurements of aerosol activity size distributions in several buildings involved in the reprocessing of Magnox Nuclear Reactor Fuel on BNFL`s Sellafield site. Whilst the 50 measurements made demonstrate significant variations in size distribution between buildings (2.8 {mu}m-4.2 {mu}m) and even between sampling locations within particular buildings (1.9 {mu}m-9.0 {mu}m), they demonstrate consistently larger particle sizes than the 1 {mu}m AMAD default value recommended in ICRP Publication 30 and provide further empirical support for the adoption of a 5 {mu}m AMAD default value as most recently proposed in ICRP Publication 66 for workplaces. (Author).

  15. Direct measurement of the matched spot size in a slow capillary discharge optical waveguide.

    Science.gov (United States)

    Antsiferov, Pavel S; Akdim, Mohamed R; van Dam, Herman T

    2007-12-01

    This communication presents direct method for experimental determining the matched spot size in a plasma optical waveguide, created in a slow capillary discharge. It can be used for Laser Wakefield Acceleration experiments in addition to interferometry for fast control of optical properties of discharge plasma. The measurements are done by means of the comparison of the laser beam size at the entrance and at the exit of the plasma channel. They are direct in the sense that the interpretation is made in terms of the refractive index without usage of the information about electron density distribution. The method can be used for matched spot size measurement in conditions of the nonlinear effects (transmission of high power laser pulses).

  16. Measuring Snow Grain Size with the Near-Infrared Emitting Reflectance Dome (NERD)

    Science.gov (United States)

    Schneider, A. M.; Flanner, M.

    2014-12-01

    Because of its high visible albedo, snow plays a large role in Earth's surface energy balance. This role is a subject of intense study, but due to the wide range of snow albedo, variations in the characteristics of snow grains can introduce radiative feedbacks in a snow pack. Snow grain size, for example, is one property which directly affects a snow pack's absorption spectrum. Previous studies model and observe this spectrum, but potential feedbacks induced by these variations are largely unknown. Here, we implement a simple and inexpensive technique to measure snow grain size in an instrument we call the Near-infrared Emitting Reflectance Dome (NERD). A small black styrene dome (~17cm diameter), fitted with two narrowband light-emitting diodes (LEDs) centered around 1300nm and 1550nm and three near-infrared reverse-biased photodiodes, is placed over the snow surface enabling a multi-spectral measurement of the hemispheric directional reflectance factor (HDRF). We illuminate the snow at each wavelength, measure directional reflectance, and infer grain size from the difference in HDRFs measured on the same snow crystals at fixed viewing angles. We validate measurements from the NERD using two different reflectance standards, materials designed to be near perfect Lambertian reflectors, having known, constant reflectances (~99% and ~55%) across a wide range of wavelengths. Using a 3D Monte Carlo model simulating photon pathways through a pack of spherical snow grains, we calculate the difference in HDRFs at 1300nm and 1550nm to predict the calibration curve for a wide range of grain sizes. This theoretically derived curve gives a relationship between effective radius and the difference in HDRFs and allows us to approximate grain sizes using the NERD in just a few seconds. Further calibration requires knowledge of truth values attainable using a previously validated instrument or measurements from an inter-comparison workshop.

  17. New Measurements of the Particle Size Distribution of Apollo 11 Lunar Soil 10084

    Science.gov (United States)

    McKay, D.S.; Cooper, B.L.; Riofrio, L.M.

    2009-01-01

    We have initiated a major new program to determine the grain size distribution of nearly all lunar soils collected in the Apollo program. Following the return of Apollo soil and core samples, a number of investigators including our own group performed grain size distribution studies and published the results [1-11]. Nearly all of these studies were done by sieving the samples, usually with a working fluid such as Freon(TradeMark) or water. We have measured the particle size distribution of lunar soil 10084,2005 in water, using a Microtrac(TradeMark) laser diffraction instrument. Details of our own sieving technique and protocol (also used in [11]). are given in [4]. While sieving usually produces accurate and reproducible results, it has disadvantages. It is very labor intensive and requires hours to days to perform properly. Even using automated sieve shaking devices, four or five days may be needed to sieve each sample, although multiple sieve stacks increases productivity. Second, sieving is subject to loss of grains through handling and weighing operations, and these losses are concentrated in the finest grain sizes. Loss from handling becomes a more acute problem when smaller amounts of material are used. While we were able to quantitatively sieve into 6 or 8 size fractions using starting soil masses as low as 50mg, attrition and handling problems limit the practicality of sieving smaller amounts. Third, sieving below 10 or 20microns is not practical because of the problems of grain loss, and smaller grains sticking to coarser grains. Sieving is completely impractical below about 5- 10microns. Consequently, sieving gives no information on the size distribution below approx.10 microns which includes the important submicrometer and nanoparticle size ranges. Finally, sieving creates a limited number of size bins and may therefore miss fine structure of the distribution which would be revealed by other methods that produce many smaller size bins.

  18. Measuring proteins with greater speed and resolution while reducing sample size

    OpenAIRE

    Hsieh, Vincent H.; Wyatt, Philip J.

    2017-01-01

    A multi-angle light scattering (MALS) system, combined with chromatographic separation, directly measures the absolute molar mass, size and concentration of the eluate species. The measurement of these crucial properties in solution is essential in basic macromolecular characterization and all research and production stages of bio-therapeutic products. We developed a new MALS methodology that has overcome the long-standing, stubborn barrier to microliter-scale peak volumes and achieved the hi...

  19. Undergraduate experiment to find nuclear sizes by measuring total cross sections for fast neutrons

    CERN Document Server

    Minor, T C; Montgomery, H E; Okun, L M; Fowler, J L

    1969-01-01

    Pu- alpha -Be neutron sources, now available in many college laboratories, used with stilbene crystal detectors and proper circuits for neutron-gamma discrimination, permit students to measure fast-neutron total cross sections for a number of easily obtained samples. From these measurements they may calculate the size of nuclei and, using elements covering a wide range of the periodic table, demonstrate the constant density of nuclear matter.

  20. Detailed measurements and modelling of thermo active components using a room size test facility

    DEFF Research Database (Denmark)

    Weitzmann, Peter; Svendsen, Svend

    2005-01-01

    measurements in an office sized test facility with thermo active ceiling and floor as well as modelling of similar conditions in a computer program designed for analysis of building integrated heating and cooling systems. A method for characterizing the cooling capacity of thermo active components is described...

  1. Influence of myocardial infarction size on radionuclide and Doppler echocardiographic measurements of diastolic function

    Energy Technology Data Exchange (ETDEWEB)

    Johannessen, K.A.; Cerqueira, M.D.; Stratton, J.R. (Seattle Veterans Administration Medical Center, WA (USA))

    1990-03-15

    To assess the relation between myocardial infarction size and diastolic function as measured by radionuclide ventriculography and Doppler echocardiography, 83 patients (aged 58 +/- 9 years) without significant valvular disease were studied 8 to 12 weeks after an acute myocardial infarction. Myocardial infarction size was measured by resting thallium-201 tomography. Peak early filling rate (in end-diastolic volumes/s) was measured by gated blood pool scintigraphy. Doppler measures of mitral inflow were peak early (E) and atrial (A) filling velocities, slopes of E and A, percent E and A filling, E/A ratio and diastolic filling period. In univariate analyses, there was a significant inverse correlation between infarction size and the peak early filling rate (r = -0.59, p less than 0.001), and this remained significant (r = -0.63, p less than 0.0001) in an analysis that included 2 other determinants of the filling rate, age and diastolic filling period. Infarction size was directly correlated to the peak E velocity (r = 0.37, p less than 0.01), deceleration of E (r = 0.41, p less than 0.01) and percent E filling (r = 0.31, p less than 0.01), and was inversely correlated to peak A (r = -0.27, p less than 0.05) and percent A filling (r = -0.26, p less than 0.05).

  2. Measuring affective (liking) and non-affective (expected satiety) determinants of portion size and food reward.

    Science.gov (United States)

    Brunstrom, Jeffrey M; Shakeshaft, Nicholas G

    2009-02-01

    Previously, we have used a 'method of constant stimuli' to quantify the satiety that different foods are expected to deliver. Our data indicate that foods differ considerably (some are expected to deliver 5-6 times more satiety than others [per kcal]). In the present study we explored the relative importance of 'expected satiety' in decisions about portion size. For eight different snack foods, we measured 'ideal' portion size and compared these values with corresponding measures of liking, expected satiety, and intention to restrict intake. Across participants (N=60), ideal portion size was predicted by both liking and expected satiety. Individuals differed in the relative importance of expected satiety and liking. In particular, expected satiety was a more important predictor in restrained eaters and in individuals with a higher BMI. In this study we also included a measure of food reward. For each food, reward was inferred from a measure based on cash spend per kcal. Again, food liking and expected satiety were both significant predictors. Together, our findings confirm the importance of expected satiety and they demonstrate the quantification of separate affective and non-affective determinants of food reward and portion size.

  3. Improved Pedagogy for Linear Differential Equations by Reconsidering How We Measure the Size of Solutions

    Science.gov (United States)

    Tisdell, Christopher C.

    2017-01-01

    For over 50 years, the learning of teaching of "a priori" bounds on solutions to linear differential equations has involved a Euclidean approach to measuring the size of a solution. While the Euclidean approach to "a priori" bounds on solutions is somewhat manageable in the learning and teaching of the proofs involving…

  4. Application of porous foams for size-selective measurements of airborne wheat allergen

    NARCIS (Netherlands)

    Bogdanovic, J.; Pater, A.J. de; Doekes, G.; Wouters, I.M.; Heederik, D.J.J.

    2006-01-01

    Background: Exposure to airborne wheat allergen is a well-known cause of bakers' allergy and asthma. Airborne wheat allergen can be measured by enzyme immunoassays (EIAs) in extracts of inhalable dust samples, but only limited knowledge is available on the size distribution of wheat

  5. Measurements of bubble size spectra within leads in the Arctic summer pack ice

    NARCIS (Netherlands)

    Norris, S.J.; Brooks, I.M.; Leeuw, G. de; Sirevaag, A.; Leck, C.; Brooks, B.J.; Birch, C.E.; Tjernstrom, M.

    2010-01-01

    The first measurements of bubble size spectra within the near-surface waters of open leads in the central Arctic pack ice were obtained during the Artic Summer Cloud-Ocean Study (ASCOS) in August 2008 at 87-87.6° N, 1-11° W. A significant number of small bubbles (30-100 μm diameter) were present,

  6. Decoupling of size and shape fluctuations in heteropolymeric sequences reconciles discrepancies in SAXS vs. FRET measurements

    NARCIS (Netherlands)

    Fuertes, Gustavo; Banterle, Niccolò; Ruff, Kiersten M; Chowdhury, Aritra; Mercadante, Davide; Koehler, Christine; Kachala, Michael; Estrada Girona, Gemma; Milles, Sigrid; Mishra, Ankur; Onck, Patrick R; Gräter, Frauke; Esteban-Martín, Santiago; Pappu, Rohit V; Svergun, Dmitri I; Lemke, Edward A

    2017-01-01

    Unfolded states of proteins and native states of intrinsically disordered proteins (IDPs) populate heterogeneous conformational ensembles in solution. The average sizes of these heterogeneous systems, quantified by the radius of gyration (RG ), can be measured by small-angle X-ray scattering (SAXS).

  7. Inductance and resistance measurement method for vessel detection and coil powering in all-surface inductive heating systems composed of outer squircle coils

    Directory of Open Access Journals (Sweden)

    Veli Tayfun Kilic

    2017-05-01

    Full Text Available In this work, we investigate a method proposed for vessel detection and coil powering in an all-surface inductive heating system composed of outer squircle coils. Besides conventional circular coils, coils with different shapes such as outer squircle coils are used for and enable efficient all-surface inductive heating. Validity of the method, which relies on measuring inductance and resistance values of a loaded coil at different frequencies, is experimentally demonstrated for a coil with shape different from conventional circular coil. Simple setup was constructed with a small coil to model an all-surface inductive heating system. Inductance and resistance maps were generated by measuring coil’s inductance and resistance values at different frequencies loaded by a plate made of different materials and located at various positions. Results show that in an induction hob for various coil geometries it is possible to detect a vessel’s presence, to identify its material type and to specify its position on the hob surface by considering inductance and resistance of the coil measured on at least two different frequencies. The studied method is important in terms of enabling safe, efficient and user flexible heating in an all-surface inductive heating system by automatically detecting the vessel’s presence and powering on only the coils that are loaded by the vessel with predetermined current levels.

  8. Measuring nanoparticles size distribution in food and consumer products: a review.

    Science.gov (United States)

    Calzolai, L; Gilliland, D; Rossi, F

    2012-08-01

    Nanoparticles are already used in several consumer products including food, food packaging and cosmetics, and their detection and measurement in food represent a particularly difficult challenge. In order to fill the void in the official definition of what constitutes a nanomaterial, the European Commission published in October 2011 its recommendation on the definition of 'nanomaterial'. This will have an impact in many different areas of legislation, such as the European Cosmetic Products Regulation, where the current definitions of nanomaterial will come under discussion regarding how they should be adapted in light of this new definition. This new definition calls for the measurement of the number-based particle size distribution in the 1-100 nm size range of all the primary particles present in the sample independently of whether they are in a free, unbound state or as part of an aggregate/agglomerate. This definition does present great technical challenges for those who must develop valid and compatible measuring methods. This review will give an overview of the current state of the art, focusing particularly on the suitability of the most used techniques for the size measurement of nanoparticles when addressing this new definition of nanomaterials. The problems to be overcome in measuring nanoparticles in food and consumer products will be illustrated with some practical examples. Finally, a possible way forward (based on the combination of different measuring techniques) for solving this challenging analytical problem is illustrated.

  9. Winter precipitation particle size distribution measurement by Multi-Angle Snowflake Camera

    Science.gov (United States)

    Huang, Gwo-Jong; Kleinkort, Cameron; Bringi, V. N.; Notaroš, Branislav M.

    2017-12-01

    From the radar meteorology viewpoint, the most important properties for quantitative precipitation estimation of winter events are 3D shape, size, and mass of precipitation particles, as well as the particle size distribution (PSD). In order to measure these properties precisely, optical instruments may be the best choice. The Multi-Angle Snowflake Camera (MASC) is a relatively new instrument equipped with three high-resolution cameras to capture the winter precipitation particle images from three non-parallel angles, in addition to measuring the particle fall speed using two pairs of infrared motion sensors. However, the results from the MASC so far are usually presented as monthly or seasonally, and particle sizes are given as histograms, no previous studies have used the MASC for a single storm study, and no researchers use MASC to measure the PSD. We propose the methodology for obtaining the winter precipitation PSD measured by the MASC, and present and discuss the development, implementation, and application of the new technique for PSD computation based on MASC images. Overall, this is the first study of the MASC-based PSD. We present PSD MASC experiments and results for segments of two snow events to demonstrate the performance of our PSD algorithm. The results show that the self-consistency of the MASC measured single-camera PSDs is good. To cross-validate PSD measurements, we compare MASC mean PSD (averaged over three cameras) with the collocated 2D Video Disdrometer, and observe good agreements of the two sets of results.

  10. Simplified product value measurement framework for small and medium sized enterprises

    Directory of Open Access Journals (Sweden)

    S Parkash

    2013-09-01

    Full Text Available Background: The emergences of global markets have increased competition worldwide. For Small Medium Sized Enterprises with limited resources to sustain in what is already a very competitive market there is a need for strong and continuously increasing Product Value to reduce business risks and revenue losses and to increase market share and customer satisfaction. To fulfill this need, Product Value Measurement is necessary to characterize the current status and further improvement. It is not easy to obtain the measures about the Product Value because its many features have qualitative characteristics. We need simplified but result oriented systematic framework to measure it while considering the measurement purpose and how to measure and why do it. Methods: How to design this is the main aim of this research paper. In this paper, GQM (Goal-Question-Metric method as a measurement framework is introduced to measure the Product Value for Small Medium Sized Enterprises along with case study to represent that this framework was effective. Results and conclusions: The proposed Model was effective for focusing on the essence of measurement and for avoiding extra excessive data not necessary for doing the effective measurement.

  11. Longitudinal measurements of syrinx size in a rat model of posttraumatic syringomyelia.

    Science.gov (United States)

    Najafi, Elmira; Bilston, Lynne E; Song, Xin; Bongers, Andre; Stoodley, Marcus A; Cheng, Shaokoon; Hemley, Sarah J

    2016-06-01

    OBJECTIVE Syringomyelia pathophysiology is commonly studied using rodent models. However, in vivo studies of posttraumatic syringomyelia have been limited by the size of animals and lack of reliable noninvasive evaluation techniques. Imaging the rat spinal cord is particularly challenging because the spinal cord diameter is approximately 1-3 mm, and pathological lesions within the spinal cord parenchyma are even smaller. The standard technique has been histological evaluation, but this has its limitations. The aim of the present study was to determine whether syrinx size could be reliably measured using a preclinical high-field MRI animal system in a rat model of posttraumatic syringomyelia. METHODS The authors used an existing rat model of posttraumatic syringomyelia, which was created using a controlled pneumatic compression device to produce the initial spinal cord injury, followed by a subarachnoid injection of kaolin to produce arachnoiditis. T2-weighted MRI was performed on each animal using a 9.4-T scanner at 7, 10, and 13 weeks after injury. Animals were killed and syrinx sizes were calculated from in vivo MRI and histological studies. RESULTS MRI measurements of syrinx volume and length were closely correlated to histological measurements across all time points (Pearson product moment correlation coefficient r = ± 0.93 and 0.79, respectively). CONCLUSIONS This study demonstrates that high-field T2-weighted MRI can be used to measure syrinx size, and data correlate well with syrinx size measured using histological methods. Preclinical MRI may be a valuable noninvasive technique for tracking syrinx formation and enlargement in animal models of syringomyelia.

  12. Pressure vessel design manual

    Energy Technology Data Exchange (ETDEWEB)

    Moss, D.R.

    1987-01-01

    The first section of the book covers types of loadings, failures, and stress theories, and how they apply to pressure vessels. The book delineates the procedures for designing typical components as well as those for designing large openings in cylindrical shells, ring girders, davits, platforms, bins and elevated tanks. The techniques for designing conical transitions, cone-cylinder intersections, intermediate heads, flat heads, and spherically dished covers are also described. The book covers the design of vessel supports subject to wind and seismic loads and one section is devoted to the five major ways of analyzing loads on shells and heads. Each procedure is detailed enough to size all welds, bolts, and plate thicknesses and to determine actual stresses.

  13. Measurement of canine pancreatic perfusion using dynamic computed tomography: Influence of input-output vessels on deconvolution and maximum slope methods

    Energy Technology Data Exchange (ETDEWEB)

    Kishimoto, Miori, E-mail: miori@mx6.et.tiki.ne.jp [Department of Clinical Veterinary Science, Obihiro University of Agriculture and Veterinary Medicine, Nishi 2-11 Inada-cho, Obihiro 080-8555 (Japan); Tsuji, Yoshihisa, E-mail: y.tsuji@extra.ocn.ne.jp [Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Shogoinkawara-cho 54, Sakyo-ku 606-8507 (Japan); Katabami, Nana; Shimizu, Junichiro; Lee, Ki-Ja [Department of Clinical Veterinary Science, Obihiro University of Agriculture and Veterinary Medicine, Nishi 2-11 Inada-cho, Obihiro 080-8555 (Japan); Iwasaki, Toshiroh [Department of Veterinary Internal Medicine, Tokyo University of Agriculture and Technology, Saiwai-cho, 3-5-8, Fuchu 183-8509 (Japan); Miyake, Yoh-Ichi [Department of Clinical Veterinary Science, Obihiro University of Agriculture and Veterinary Medicine, Nishi 2-11 Inada-cho, Obihiro 080-8555 (Japan); Yazumi, Shujiro [Digestive Disease Center, Kitano Hospital, 2-4-20 Ougi-machi, Kita-ku, Osaka 530-8480 (Japan); Chiba, Tsutomu [Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Shogoinkawara-cho 54, Sakyo-ku 606-8507 (Japan); Yamada, Kazutaka, E-mail: kyamada@obihiro.ac.jp [Department of Clinical Veterinary Science, Obihiro University of Agriculture and Veterinary Medicine, Nishi 2-11 Inada-cho, Obihiro 080-8555 (Japan)

    2011-01-15

    Objective: We investigated whether the prerequisite of the maximum slope and deconvolution methods are satisfied in pancreatic perfusion CT and whether the measured parameters between these algorithms are correlated. Methods: We examined nine beagles injected with iohexol (200 mgI kg{sup -1}) at 5.0 ml s{sup -1}. The abdominal aorta and splenic and celiac arteries were selected as the input arteries and the splenic vein, the output veins. For the maximum slope method, we determined the arterial contrast volume of each artery by measuring the area under the curve (AUC) and compared the peak enhancement time in the pancreas with the contrast appearance time in the splenic vein. For the deconvolution method, the artery-to-vein collection rate of contrast medium was calculated. We calculated the pancreatic tissue blood flow (TBF), tissue blood volume (TBV), and mean transit time (MTT) using both algorithms and investigated their correlation based on vessel selection. Results: The artery AUC significantly decreased as it neared the pancreas (P < 0.01). In all cases, the peak time of the pancreas (11.5 {+-} 1.6) was shorter than the appearance time (14.1 {+-} 1.6) in the splenic vein. The splenic artery-vein combination exhibited the highest collection rate (91.1%) and was the only combination that was significantly correlated between TBF, TBV, and MTT in both algorithms. Conclusion: Selection of a vessel nearest to the pancreas is considered as a more appropriate prerequisite. Therefore, vessel selection is important in comparison of the semi-quantitative parameters obtained by different algorithms.

  14. Measuring the effectiveness of marketing activities use in relation to company size

    Directory of Open Access Journals (Sweden)

    Lucie Sychrová

    2013-01-01

    Full Text Available The aim of this paper is to research the relationship between measurements of effectiveness of marketing activities and company size. An analysis of the economic sources, professional publications, analysis and reports of previous research shows that the concept of measuring of effectiveness is one of the key themes, which economists always pay much attention. It is a criterion that helps to rationally decide on the use limited resources to meet the needs that are not limited. This topic deals with numerous domestic and foreign literatures. The authors are not only different concepts of effectiveness, but also the using terminology. There are multiple definitions of terms “effectiveness” For the same purpose and meaning. The same concept is often defined semantically different. Therefore, every company has a strong interest to be in all their activities more effectively than the competition. Logical response to changes and requirements of nowadays is using a combination of lot of methods to measure marketing effectiveness. Methods used for this article includes two phases. The first it was gained date by primary research, using a structure questionnaire and processed by statistical software SPSS. Research sample consists 115 companies operating in the Czech environment, which was chosen at random. There is investigated the correlation between measuring the effectiveness of marketing activities and company size. The second part investigated the dependence between the choice of metrics used to measure the effectiveness and company size. The results of the research showed that there is no correlation between measuring the effectiveness of marketing activities and company size. The value of Pearson Chi-Square test is greater than 0.05, it is 0.187. We can presume that dependency does not exist or it is small for these. Value of Symmetric measures is 0.432, which means that the intensity tends to be small rather than high.

  15. Soot particle size measurements in ethylene diffusion flames at elevated pressures

    KAUST Repository

    Steinmetz, Scott

    2016-05-07

    Soot particle size is investigated in laminar nitrogen-diluted ethylene coflow diffusion flames at 4, 8, 12 and 16 atm. Line of sight attenuation and scattering are used to measure two-dimensional soot volume fraction and particle size fields for the first time at elevated pressures. Soot volume fraction dependence on pressure is consistent with the observations of similar studies, scaling approximately with the square of pressure. Scattering intensity is analyzed through Rayleigh and Rayleigh-Debye-Gans polydisperse fractal aggregate theories to provide two estimates of particle size. An increase in overall particle sizes with pressure is found, consistent with similar one-dimensional studies. Particle diameters in the annulus of the flame increase faster with pressure than those on centerline. Contrary to previous studies, the dependence of particle size on pressure was found to taper off between 8 and 12 atm, with little observed growth beyond 12 atm. The measurements provide additional data for one of the International Sooting Flame (ISF) workshop\\'s target pressurized flames.

  16. Comparison of Drop Size Distribution Measurements by Impact and Optical Disdrometers.

    Science.gov (United States)

    Tokay, Ali; Kruger, Anton; Krajewski, Witold F.

    2001-11-01

    Simultaneous observations made with optical- and impact-type disdrometers were analyzed to broaden knowledge of these instruments. These observations were designed to test how accurately they measure drop size distributions (DSDs). The instruments' use in determining radar rainfall relations such as that between reflectivity and rainfall rate also was analyzed. A unique set of instruments, including two video and one Joss-Waldvogel disdrometer along with eight tipping-bucket rain gauges, was operated within a small area of about 100 × 50 m2 during a 2-month-long field campaign in central Florida. The disdrometers were evaluated by comparing their rain totals with the rain gauges. Both disdrometers underestimated the rain totals, but the video disdrometers had higher readings, resulting in a better agreement with the gauges. The disdrometers underreported small- to medium-size drops, which most likely caused the underestimation of rain totals. However, more medium-size drops were measured by the video disdrometer, thus producing higher rain rates for that instrument. The comparison of DSDs, averaged at different timescales, showed good agreement between the two types of disdrometers. A continuous increase in the number of drops toward smaller sizes was only evident in the video disdrometers at rain rates above 20 mm h1. Otherwise, the concentration of small drops remained the same or decreased to the smallest measurable size. The Joss-Waldvogel disdrometer severely underestimated only at very small drop size (diameter 0.5 mm). Beyond the Joss-Waldvogel disdrometer measurement limit were very large drops that fell during heavy and extreme rain intensities. The derived parameters of exponential and gamma distributions reflect the good agreement between the disdrometers' DSD measurements. The parameters of fitted distributions were close to each other, especially when all the coincident measurements were averaged. The low concentrations of very large drops observed by

  17. Passive acoustic measurement of bedload grain size distribution using self-generated noise

    Science.gov (United States)

    Petrut, Teodor; Geay, Thomas; Gervaise, Cédric; Belleudy, Philippe; Zanker, Sebastien

    2018-01-01

    Monitoring sediment transport processes in rivers is of particular interest to engineers and scientists to assess the stability of rivers and hydraulic structures. Various methods for sediment transport process description were proposed using conventional or surrogate measurement techniques. This paper addresses the topic of the passive acoustic monitoring of bedload transport in rivers and especially the estimation of the bedload grain size distribution from self-generated noise. It discusses the feasibility of linking the acoustic signal spectrum shape to bedload grain sizes involved in elastic impacts with the river bed treated as a massive slab. Bedload grain size distribution is estimated by a regularized algebraic inversion scheme fed with the power spectrum density of river noise estimated from one hydrophone. The inversion methodology relies upon a physical model that predicts the acoustic field generated by the collision between rigid bodies. Here we proposed an analytic model of the acoustic energy spectrum generated by the impacts between a sphere and a slab. The proposed model computes the power spectral density of bedload noise using a linear system of analytic energy spectra weighted by the grain size distribution. The algebraic system of equations is then solved by least square optimization and solution regularization methods. The result of inversion leads directly to the estimation of the bedload grain size distribution. The inversion method was applied to real acoustic data from passive acoustics experiments realized on the Isère River, in France. The inversion of in situ measured spectra reveals good estimations of grain size distribution, fairly close to what was estimated by physical sampling instruments. These results illustrate the potential of the hydrophone technique to be used as a standalone method that could ensure high spatial and temporal resolution measurements for sediment transport in rivers.

  18. Optical Measurement Technologies for High Temperature, Radiation Exposure, and Corrosive Environments—Significant Activities and Findings: In-vessel Optical Measurements for Advanced SMRs

    Energy Technology Data Exchange (ETDEWEB)

    Anheier, Norman C.; Cannon, Bret D.; Qiao, Hong (Amy); Suter, Jonathan D.

    2012-09-01

    Development of advanced Small Modular Reactors (aSMRs) is key to providing the United States with a sustainable, economically viable, and carbon-neutral energy source. The aSMR designs have attractive economic factors that should compensate for the economies of scale that have driven development of large commercial nuclear power plants to date. For example, aSMRs can be manufactured at reduced capital costs in a factory and potentially shorter lead times and then be shipped to a site to provide power away from large grid systems. The integral, self-contained nature of aSMR designs is fundamentally different than conventional reactor designs. Future aSMR deployment will require new instrumentation and control (I&C) architectures to accommodate the integral design and withstand the extreme in-vessel environmental conditions. Operators will depend on sophisticated sensing and machine vision technologies that provide efficient human-machine interface for in-vessel telepresence, telerobotic control, and remote process operations. The future viability of aSMRs is dependent on understanding and overcoming the significant technical challenges involving in-vessel reactor sensing and monitoring under extreme temperatures, pressures, corrosive environments, and radiation fluxes

  19. An inverse modeling procedure to determine particle growth and nucleation rates from measured aerosol size distributions

    Directory of Open Access Journals (Sweden)

    B. Verheggen

    2006-01-01

    Full Text Available Classical nucleation theory is unable to explain the ubiquity of nucleation events observed in the atmosphere. This shows a need for an empirical determination of the nucleation rate. Here we present a novel inverse modeling procedure to determine particle nucleation and growth rates based on consecutive measurements of the aerosol size distribution. The particle growth rate is determined by regression analysis of the measured change in the aerosol size distribution over time, taking into account the effects of processes such as coagulation, deposition and/or dilution. This allows the growth rate to be determined with a higher time-resolution than can be deduced from inspecting contour plots ('banana-plots''. Knowing the growth rate as a function of time enables the evaluation of the time of nucleation of measured particles of a certain size. The nucleation rate is then obtained by integrating the particle losses from time of measurement to time of nucleation. The regression analysis can also be used to determine or verify the optimum value of other parameters of interest, such as the wall loss or coagulation rate constants. As an example, the method is applied to smog chamber measurements. This program offers a powerful interpretive tool to study empirical aerosol population dynamics in general, and nucleation and growth in particular.

  20. Design of a Fast Measuring System for the Section Size of Automobile Rubber Hose Withhold Parts

    Science.gov (United States)

    Meng, Fanwu; Zhang, Teng; Ren, Jingrui

    2017-12-01

    The quality of withhold parts determines the service life of high-pressure rubber hose to a great extent. Leakage at withholding is the main form of high pressure hose failure in the several forms. The quickest and most effective method to detect the withholding quality is measuring the section size of the withhold parts. As long as the section size is in line with the provisions, that is, the quality of hose withholding is qualified. In this paper, the mesurement system which is designed improves low efficiency of manual mesurement.

  1. Understanding of cluster size deviation by measuring the dimensions of cluster jet from conical nozzles

    Directory of Open Access Journals (Sweden)

    Guanglong Chen

    2013-03-01

    Full Text Available This work aims to understand the cluster size deviation from the prediction by an existing scaling law for conical nozzles. The dimensions of cluster jet at different heights above a nozzle along the direction of gas flow are measured. This study indicates that the dimension of cluster jet is underestimated in the existing scaling law and this under-estimation leads to the over-estimation of the equivalent diameter of conical nozzle. Thus the underestimation of the dimension of cluster jet may be one of possible factors responsible for the cluster size deviation (the degree of the deviation depends on details of cluster jet.

  2. 46 CFR 69.7 - Vessels transiting the Panama and Suez Canals.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Vessels transiting the Panama and Suez Canals. 69.7... MEASUREMENT OF VESSELS MEASUREMENT OF VESSELS General § 69.7 Vessels transiting the Panama and Suez Canals. (a) All vessels intending to transit the Panama Canal, other than vessels of war, must be measured and...

  3. Finite-size analysis of measurement-device-independent quantum cryptography with continuous variables

    Science.gov (United States)

    Papanastasiou, Panagiotis; Ottaviani, Carlo; Pirandola, Stefano

    2017-10-01

    We study the impact of finite-size effects on the key rate of continuous-variable (CV) measurement-device-independent (MDI) quantum key distribution (QKD), considering two-mode Gaussian attacks. Inspired by the parameter estimation technique developed in by Ruppert et al. [Phys. Rev. A 90, 062310 (2014), 10.1103/PhysRevA.90.062310], we adapt it to study CV-MDI-QKD and, assuming realistic experimental conditions, we analyze the impact of finite-size effects on the key rate. We find that the performance of the protocol approaches the ideal one, increasing the block size, and, most importantly, that blocks between 106 and 109 data points may provide key rates ˜10-2 bit/use over metropolitan distances.

  4. Particle size distributions in polar mesospheric clouds derived from solar mesosphere explorer measurements

    Science.gov (United States)

    Rusch, D. W.; Thomas, G. E.; Jensen, E. J.

    1991-01-01

    Data from the visible and UV spectrometers on the Solar Mesosphere Explorer are used to derive the color ratios of the reflectance at 265, 296, and 393 nm of light scattered from polar mesospheric cloud particles. This analysis extends the spectral coverage into the visible region of the spectrum. The data reduction technique compared the cloud brightness to the brightness scattered from the background atmosphere at the same wavelength. The ratios determined in this way are independent of systematic errors in instrument radiometric calibration. The data are analyzed using theoretical determinations of the color ratios from the Mie theory of small particle scattering, assuming a lognormal distribution for the particle size dispersion. Here 'size' means the average radius of the sphere having the same ice volume. The present results confirm earlier findings that the effective sizes of polar mesospheric cloud particles are less than 70 nm. Still, there exists a small number of measurements which result in particle sizes of the order of 80 nm. Even for these large particle sizes the required vertical column content of water vapor does not exceed limits imposed by the available atmospheric water vapor concentrations.

  5. Retrieval of snow albedo and grain size using reflectance measurements in Himalayan basin

    Directory of Open Access Journals (Sweden)

    H. S. Negi

    2011-03-01

    Full Text Available In the present paper, spectral reflectance measurements of Himalayan seasonal snow were carried out and analysed to retrieve the snow albedo and effective grain size. The asymptotic radiative transfer (ART theory was applied to retrieve the plane and spherical albedo. The retrieved plane albedo was compared with the measured spectral albedo and a good agreement was observed with ±10% differences. Retrieved integrated albedo was found within ±6% difference with ground observed broadband albedo. The retrieved snow grain sizes using different models based on the ART theory were compared for various snow types and it was observed that the grain size model using two channel method (one in visible and another in NIR region can work well for the Himalayan seasonal snow and it was found consistent with temporal changes in grain size. This method can work very well for clean, dry snow as in the upper Himalaya, but sometimes, due to the low reflectances (<20% using wavelength 1.24 μm, the ART theory cannot be applied, which is common in lower and middle Himalayan old snow. This study is important for monitoring the Himalayan cryosphere using air-borne or space-borne sensors.

  6. Specimen size effect in the volumetric shrinkage of cancellous bone measured at two levels of dehydration.

    Science.gov (United States)

    Lievers, W Brent; Lee, Victoria; Arsenault, Simon M; Waldman, Stephen D; Pilkey, A Keith

    2007-01-01

    Water is commonly removed from bone to study its effect on mechanical behaviour; however, dehydration also alters the bone structure. To make matters worse, measuring structural changes in cancellous bone is complicated by a number of factors. Therefore, the goals of this study were to address these issues by (1) comparing Archimedes' method and a helium pycnometer as methods for measuring cancellous bone volume; (2) measuring the apparent dimensional and volumetric tissue shrinkage of cancellous bone at two levels of dehydration; and, (3) identifying whether a size effect exists in cancellous bone shrinkage. Cylindrical specimens (3, 5 and 8.3 mm diameters) of cancellous bone were taken from the distal bovine femur. The apparent dimensions of each cylindrical specimen were measured in a fully hydrated state (HYD), after drying at room temperature (AIR), and after oven drying at 105 degrees C (OVEN). Tissue volume measurements for those three hydration states were obtained using both a helium pycnometer and Archimedes' method. Aluminium foams, which mimic the cancellous structure, were used as controls. The results suggest that the helium pycnometer and Archimedes' method yield identical results in the HYD and AIR states, but that Archimedes' method under-predicts the nominal OVEN volume by incorporating the collagen-apatite porosity. A distinct size effect on volumetric shrinkage is observed (pshrinkage (2% and 7%) at the two dehydration levels is much smaller than the measured volumetric tissue shrinkage (16% and 29%), which results in a reduced dehydrated bone volume fraction.

  7. Fluids and their Effect on Measurements on Lunar Soil Particle size Distribution

    Science.gov (United States)

    Cooper, B. L.; McKay, D. S.; Wallace, W. T.; Gonzalex, C. P.

    2011-01-01

    From the late 1960s until now, lunar soil particle size distributions have typically been determined by sieving sometimes dry, and at other times with fluids such as water or Freon. Laser diffraction instruments allow rapid assessment of particle size distribution, and eventually may replace sieve measurements. However, when measuring lunar soils with laser diffraction instruments, care must be taken in choosing a carrier fluid that is compatible with lunar material. Distilled water is the fluid of choice for laser diffraction measurements of substances when there is no concern about adverse effects of water on the material being measured. When we began our analyses of lunar soils using laser diffraction, our first measurements were made with distilled water. Although the medians that we measured were comparable to earlier sieve data, the means tended to be significantly larger than expected. The effect of water vapor on lunar soil has been studied extensively. The particles interact strongly with water vapor, and subsequent adsorptions of nitrogen showed that the specific surface area increased as much as threefold after exposure to moisture. It was observed that significant porosity had been generated by this exposure to water vapor. The possibility of other physical changes in the surfaces of the grains was not studied.

  8. Angiographic Findings of the Multicenter Randomized Study With the Sirolimus-Eluting Bx Velocity Balloon-Expandable Stent (RAVEL) : Sirolimus-Eluting Stents Inhibit Restenosis Irrespective of the Vessel Size

    NARCIS (Netherlands)

    E.S. Regar (Eveline); M. Degertekin (Muzaffer); M-C. Morice (Marie-Claude); K. Tanabe (Kengo); E. Wülfert (Egon); C. Disco (Clemens); C. Holubarsch; J-L. Guermonprez (Jean-Leon); W. Wijns (William); A. Bartorelli (Antonio); P.W.J.C. Serruys (Patrick); C.H. Bode (Christoph); C. Constantini (Constantino)

    2002-01-01

    markdownabstractBACKGROUND: Restenosis remains the major limitation of coronary catheter-based intervention. In small vessels, the amount of neointimal tissue is disproportionately greater than the vessel caliber, resulting in higher restenosis rates. In the Randomized Study With the

  9. High-Resolution UV Holography Lens for Particle Size Distribution Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Malone, Morris Kaufman; Capelle, Gene; Grover, Mike; Sorenson, Dan; Pazuchanics, Pete

    2010-01-01

    A high-resolution UV holography relay lens, shown in Figure 1, has been developed for measuring particle size distributions down to 0.5 μm in a 12-mm-diameter by 5-mm-thick volume. This work has been selected by an independent judging panel and editors of R&D Magazine as a recipient of a 2009 R&D 100 Award. This award recognizes the 100 most technologically significant products introduced during the past year.

  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. Simultaneous measurement of lateral and vertical size of nanoparticles using transmission scanning electron microscopy (TSEM)

    Science.gov (United States)

    Buhr, E.; Bug, M. U.; Bergmann, D.; Cizmar, P.; Frase, C. G.

    2017-03-01

    A scanning electron microscope operated in transmission mode (TSEM) enables both the measurement of the lateral and vertical size (thickness) of nanoparticles. The lateral size is measured with a previously described technique where the particle boundary is determined in the TSEM image. Particle thickness is deduced from the TSEM signal level measured at the centre of the particle, which requires prior knowledge of the expected TSEM signal level. We applied different and well-known Monte-Carlo based simulation tools (Geant4 and MCSEM) to describe the electron diffusion in solid states and to calculate the expected TSEM signals taking into account particle and instrument properties. The simulation results of the different simulation models differ slightly revealing current limits of small-angle and low-energy electron scattering modelling in solid states. Nonetheless, the method allows one to correlate lateral and vertical particle thickness and thus to obtain additional information about the 3D morphology of nanoparticles. We demonstrate the method for silica particles with sizes in the range of about 10 nm-100 nm.

  12. Floc size distributions of suspended kaolinite in an advection transport dominated tank: measurements and modeling

    Science.gov (United States)

    Shen, Xiaoteng; Maa, Jerome P.-Y.

    2017-11-01

    In estuaries and coastal waters, floc size and its statistical distributions of cohesive sediments are of primary importance, due to their effects on the settling velocity and thus deposition rates of cohesive aggregates. The development of a robust flocculation model that includes the predictions of floc size distributions (FSDs), however, is still in a research stage. In this study, a one-dimensional longitudinal (1-DL) flocculation model along a streamtube is developed. This model is based on solving the population balance equation to find the FSDs by using the quadrature method of moments. To validate this model, a laboratory experiment is carried out to produce an advection transport-dominant environment in a cylindrical tank. The flow field is generated by a marine pump mounted at the bottom center, with its outlet facing upward. This setup generates an axially symmetric flow which is measured by an acoustic Doppler velocimeter (ADV). The measurement results provide the hydrodynamic input data required for this 1-DL model. The other measurement results, the FSDs, are acquired by using an automatic underwater camera system and the resulting images are analyzed to validate the predicted FSDs. This study shows that the FSDs as well as their representative sizes can be efficiently and reasonably simulated by this 1-DL model.

  13. IN SITU MEASUREMENTS OF THE SIZE AND DENSITY OF TITAN AEROSOL ANALOGS

    Energy Technology Data Exchange (ETDEWEB)

    Hoerst, S. M.; Tolbert, M. A, E-mail: sarah.horst@colorado.edu [Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO (United States)

    2013-06-10

    The organic haze produced from complex CH{sub 4}/N{sub 2} chemistry in the atmosphere of Titan plays an important role in processes that occur in the atmosphere and on its surface. The haze particles act as condensation nuclei and are therefore involved in Titan's methane hydrological cycle. They also may behave like sediment on Titan's surface and participate in both fluvial and aeolian processes. Models that seek to understand these processes require information about the physical properties of the particles including their size and density. Although measurements obtained by Cassini-Huygens have placed constraints on the size of the haze particles, their densities remain unknown. We have conducted a series of Titan atmosphere simulation experiments and measured the size, number density, and particle density of Titan aerosol analogs, or tholins, for CH{sub 4} concentrations from 0.01% to 10% using two different energy sources, spark discharge and UV. We find that the densities currently in use by many Titan models are higher than the measured densities of our tholins.

  14. The effects of focused transducer geometry and sample size on the measurement of ultrasonic transmission properties

    Science.gov (United States)

    Atkins, T. J.; Humphrey, V. F.; Duck, F. A.; Tooley, M. A.

    2011-02-01

    The response of two coaxially aligned weakly focused ultrasonic transducers, typical of those employed for measuring the attenuation of small samples using the immersion method, has been investigated. The effects of the sample size on transmission measurements have been analyzed by integrating the sound pressure distribution functions of the radiator and receiver over different limits to determine the size of the region that contributes to the system response. The results enable the errors introduced into measurements of attenuation to be estimated as a function of sample size. A theoretical expression has been used to examine how the transducer separation affects the receiver output. The calculations are compared with an experimental study of the axial response of three unpaired transducers in water. The separation of each transducer pair giving the maximum response was determined, and compared with the field characteristics of the individual transducers. The optimum transducer separation, for accurate estimation of sample properties, was found to fall between the sum of the focal distances and the sum of the geometric focal lengths as this reduced diffraction errors.

  15. Light Source for Scanning Method of Size-of-Source Effect Measurement

    Science.gov (United States)

    Achmadi, Aditya; Juliastuti, Endang; Handojo, Andrianto; Zaid, Ghufron; Wiriadinata, Hidayat; Park, Seung-Nam

    2015-12-01

    A high-power light-emitting diode (HPLED) is proposed as a new light source for the measurement of the size-of-source effect (SSE) in radiation thermometers. The HPLED is a more compact, simple, and inexpensive light source and is suitable for SSE measurement by the scanning method. An experiment has been done using a 3 W HPLED with a hemispherical front lens and a peak emission wavelength of 660 nm. A linear pyrometer (Model LP4 manufactured by KE) was used for the measurements. The scanning process was carried out by using a computerized linear translation stage spanning 500 mm. To confirm the measurement result, the SSE of the LP4 was also measured by the conventional indirect method using an integrating sphere with a 65 mm diameter exit port. The same trends of the SSE value of the scanning and indirect method were found in all ranges of the indirect method measurement. The results show that the light source has enough brightness and a sufficiently wide angular distribution to provide a dynamic measurement range of up to 108 and allow the measurement of the SSE up to a radius of 500 mm. These results support the application of HPLED as an alternative light source for SSE measurements by the scanning method.

  16. Power and sample size determination for measures of environmental impact in aquatic systems

    Energy Technology Data Exchange (ETDEWEB)

    Ammann, L.P. [Univ. of Texas, Richardson, TX (United States); Dickson, K.L.; Waller, W.T.; Kennedy, J.H. [Univ. of North Texas, Denton, TX (United States); Mayer, F.L.; Lewis, M. [Environmental Protection Agency, Gulf Breeze, FL (United States)

    1994-12-31

    To effectively monitor the status of various freshwater and estuarine ecological systems, it is necessary to understand the statistical power associated with the measures of ecological health that are appropriate for each system. These power functions can then be used to determine sample sizes that are required to attain targeted change detection likelihoods. A number of different measures have been proposed and are used for such monitoring. these include diversity and evenness indices, richness, and organisms counts. Power functions can be estimated when preliminary or historical data are available for the region and system of interest. Unfortunately, there are a number of problems associated with the computation of power functions and sample sizes for these measures. These problems include the presence of outliers, co-linearity among the variables, and non-normality of count data. The problems, and appropriate methods to compute the power functions, for each of the commonly employed measures of ecological health will be discussed. In addition, the relationship between power and the level of taxonomic classification used to compute the measures of diversity, evenness, richness, and organism counts will be discussed. Methods for computation of the power functions will be illustrated using data sets from previous EPA studies.

  17. Vessel Operator System

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Operator cards are required for any operator of a charter/party boat and or a commercial vessel (including carrier and processor vessels) issued a vessel permit from...

  18. Retrievals of Cloud Droplet Size from the Research Scanning Polarimeter Data: Validation Using in Situ Measurements

    Science.gov (United States)

    Alexandrov, M. D.; Cairns, B.; Sinclair, K.; Wasilewski, A. P.; Ziemba, L. D.; Crosbie, E.; Hair, J. W.; Hu, Y.; Hostetler, C. A.; Stamnes, S.

    2016-12-01

    We present comparisons of cloud droplet size distributions retrieved from the Research Scanning Polarimeter (RSP) data with correlative in situ measurements made during the North Atlantic Aerosols and Marine Ecosystems Study (NAAMES). This field experiment was based at St. John's airport, Newfoundland, Canada with the latest deployment in May - June 2016. RSP was onboard the NASA C-130 aircraft together with an array of in situ and other remote sensing instrumentation. The RSP is an along-track scanner measuring polarized and total reflectances in 9 spectral channels. Its unique high angular resolution allows for characterization of liquid water droplet size using the rainbow structure observed in the polarized reflectances in the scattering angle range between 135 and 165 degrees. A parametric fitting algorithm applied to the polarized reflectances provides retrievals of the droplet effective radius and variance assuming a prescribed size distribution shape (gamma distribution). In addition to this, we use a non-parametric method, Rainbow Fourier Transform (RFT), which allows us to retrieve the droplet size distribution (DSD) itself. The latter is important in the case of clouds with complex structure, which results in multi-modal DSDs. During NAAMES the aircraft performed a number of flight patterns specifically designed for comparison of remote sensing retrievals and in situ measurements. These patterns consisted of two flight segments above the same straight ground track. One of these segments was flown above clouds allowing for remote sensing measurements, while the other was at the cloud top where cloud droplets were sampled. We compare the DSDs retrieved from the RSP data with in situ measurements made by the Cloud Droplet Probe (CDP). The comparisons show generally good agreement with deviations explainable by the position of the aircraft within cloud and by presence of additional cloud layers in RSP view that do not contribute to the in situ DSDs. In the

  19. Retrievals of Cloud Droplet Size from the RSP Data: Validation Using in Situ Measurements

    Science.gov (United States)

    Alexandrov, Mikhail D.; Cairns, Brian; Sinclair, Kenneth; Wasilewski, Andrzej P.; Ziemba, Luke; Crosbie, Ewan; Hair, John; Hu, Yongxiang; Hostetler, Chris; Stamnes, Snorre

    2016-01-01

    We present comparisons of cloud droplet size distributions retrieved from the Research Scanning Polarimeter (RSP) data with correlative in situ measurements made during the North Atlantic Aerosols and Marine Ecosystems Study (NAAMES). This field experiment was based at St. Johns airport, Newfoundland, Canada with the latest deployment in May - June 2016. RSP was onboard the NASA C-130 aircraft together with an array of in situ and other remote sensing instrumentation. The RSP is an along-track scanner measuring polarized and total reflectances in9 spectral channels. Its unique high angular resolution allows for characterization of liquid water droplet size using the rainbow structure observed in the polarized reflectances in the scattering angle range between 135 and 165 degrees. A parametric fitting algorithm applied to the polarized reflectances provides retrievals of the droplet effective radius and variance assuming a prescribed size distribution shape (gamma distribution). In addition to this, we use a non-parametric method, Rainbow Fourier Transform (RFT), which allows us to retrieve the droplet size distribution (DSD) itself. The latter is important in the case of clouds with complex structure, which results in multi-modal DSDs. During NAAMES the aircraft performed a number of flight patterns specifically designed for comparison of remote sensing retrievals and in situ measurements. These patterns consisted of two flight segments above the same straight ground track. One of these segments was flown above clouds allowing for remote sensing measurements, while the other was at the cloud top where cloud droplets were sampled. We compare the DSDs retrieved from the RSP data with in situ measurements made by the Cloud Droplet Probe (CDP). The comparisons show generally good agreement with deviations explainable by the position of the aircraft within cloud and by presence of additional cloud layers in RSP view that do not contribute to the in situ DSDs. In the

  20. Measuring the stratospheric aerosol size distribution profile following the next big volcanic eruption. What is required?

    Science.gov (United States)

    Deshler, T.

    2015-12-01

    Two of the key missing features of fresh and evolving volcanic plumes are the particle size distribution and its partitioning into non-volatile ash and volatile sulfate particles. Such information would allow more refined estimates of the evolution and dispersal of the aerosol, of the impacts of the aerosol on radiation and on stratospheric chemistry, and of the overall amount of sulfur injected into the stratosphere. To provide this information aerosol measurements must be sensitive to particles in the 0.1 - 10 μm radius range, with concentration detection thresholds > 0.001 cm-3, and to the total aerosol population. An added bonus would be a size resolved measurement of the non-volatile fraction of the aerosol. The measurements must span the lower and mid stratosphere up to about 30 km. There are no remote measurements which can provide this information. In situ measurements using aerosol and condensation nuclei counters are required. Aircraft platforms are available for measurements up to 20 km, but beyond that requires balloon platforms. Measurements above 20 km would be required for a large volcanic eruption. There are balloon-borne instruments capable of fulfilling all of the measurement requirements; however such instruments are reasonably large and not expendable. The difficulty is deploying the instruments, obtaining the flight permissions from air traffic control, and recovering the instruments after flight. Such difficulties are compounded in the tropics. This talk will detail some previous experience in this area and suggest ways forward to be ready for the next big eruption.

  1. Study of the functional state of peripheral vessels in fingers of rheumatological patients by means of laser Doppler flowmetry and cutaneous thermometry measurements

    Science.gov (United States)

    Zherebtsova, Angelina I.; Zherebtsov, Evgeny A.; Dunaev, Andrey V.; Podmasteryev, Konstantin V.; Pilipenko, Olga V.; Krupatkin, Alexander I.; Khakhicheva, Lyudmila S.; Muradyan, Vadim F.

    2016-04-01

    Vasospastic disorders are a common class of rheumatic disease. These include syndromes such as vegetative dystonia, Raynaud's syndrome, vibration disease and rheumatoid arthritis among others. The aim of this work is to develop an original method of diagnosing the functional state of peripheral vessels of the fingers, based on the simultaneous recording of LDF- and thermograms during the occlusion test, for determining vascular disorders of rheumatological patients. A diagnostic method was developed for assessing the functional state of the peripheral vessels of fingers, based on carrying out occlusion test in a thermally stabilized environment, with simultaneous recording of signals of laser Doppler flowmetry and skin thermometry. To verify the diagnostic value of the proposed method, a series of experiments were carried out on 41 rheumatological patients: 5 male and 36 females (average age 56.0+/-12.2 years). The most common diagnoses in the patient group were rheumatoid arthritis, arthrosis, gout and systemic lupus erythematosus. The laser analyser of blood microcirculation "LAKK-02" (SPE "LAZMA" Ltd, Russia) and a custom developed multi-channel thermometry device for low inertia thermometry were used for experimental measurements. The measurements of cutaneous temperature and the index of microcirculation were performed on the distal phalanx of the third finger of the right hand. Occlusion tests were performed with water baths at 25 and 42 °C and a tonometer cuff with a pressure of 200-220 mmHg for 3 min on the upper arm. The results of experimental studies are presented and interpreted. These data indicate a violation of the blood supply regulation in the form of a pronounced tendency towards microvascular vasoconstriction in the fingers. Thus, the response displaying a tendency toward angiospasm among patients in the rheumatological diseases profile group was observed mainly in the most severe cases (49 % of this group). The prospects of the developed

  2. Concentration Measurements of Suspended Load using ADV with Influence of the Particle Size

    Science.gov (United States)

    Schwarzwälder, Kordula

    2017-04-01

    ADV backscatter data can be used under certain conditions to gain information about the concentrations of suspended loads. This was shown in many studies before (Fugate and Friedrichs 2002; Chanson et al 2008; Ha et al. 2009). This paper reports on a pre-study to investigate the influence of particle size on concentration measurements for suspended sediment load with ADV. The study was conducted in a flume in the Oskar-von-Miller-Institute using fresh water from a river including the natural suspended load. The ADV used in the experiments was a Vectrino Profiler (Nortek). In addition water samples were taken for TSS and TOC. For the measurements a surge was generated in the flume to ensure that also particles of larger size will be present in the water phase. The measurements and samples were taken during the whole surge event. Therefore we were able to find a good correlation between the backscatter data of the ADV and the TSS as well as TOC results. For the decreasing part of the flow event the concentration of TOC in the suspended load of the water phase is decreasing much slower than the TSS and results in a damped decrease of the backscatter values. This means that the results for concentration measurements might be slightly influenced by the size of the particles. Further evaluations of measurements conducted with a LISST SL (Sequoia) will be investigated to show the trend of the particle sizes during this process and fortify this result. David C. Fugate, Carl T. Friedrichs, Determining concentration and fall velocity of estuarine particle populations using ADV, OBS and LISST, Continental Shelf Research, Volume 22, Issues 11-13, 2002 H.K. Ha, W.-Y. Hsu, J.P.-Y. Maa, Y.Y. Shao, C.W. Holland, Using ADV backscatter strength for measuring suspended cohesive sediment concentration, Continental Shelf Research, Volume 29, Issue 10, 2009 Hubert Chanson, Maiko Takeuchi, Mark Trevethan, Using turbidity and acoustic backscatter intensity as surrogate measures of

  3. Comparison of two methods for short circuit current measurement of large size solar cell

    Science.gov (United States)

    Huang, Xuebo; Quan, Chenggen; Kng, Jerald

    2015-07-01

    The differential spectral responsivity (DSR) measurement and the solar simulator based current to voltage characterisation methods are two accurate methods for measuring the short circuit current, a critical parameter, of a solar cell under standard testing conditions. For the calibration of World Photovoltaic Scale (WPVS) reference solar cell with small size (20 mm x 20 mm), the measurement results using these two methods are agreed well within 1%. But for the calibration of large size (e.g. 156 mm x 156 mm) of solar cell, the measurement results using two methods are not agreed well and their deviation could be more than 10 %. In DSR method, the short circuit current of a solar cell is determined through measuring its relative irradiance spectral responsivity in spectral range from 280 nm to 1200 nm and its absolute irradiance responsivity at wavelength of 650 nm by reference standard photodiodes. As the detective area of large size solar cell (detective area: 156 mm x 156 mm) is much bigger than that of standard photodiodes (detective area: 12.56 mm2), the spatial uniformity of irradiance of modulated monochromatic probe beam on the test solar cell and the standard photodiode is critical for calculation of absolute irradiance responsivity of the test solar cell. The correction for the calculation must be done according to the measured spatial uniformity of probe beam and the detective areas of the test solar cell and standard photodiodes. The experiment showed the correction factor and its uncertainty are smaller if the detective areas difference between the test solar cell and the standard is smaller. Based on this observation, a standard solar cell (detective area: 20 mm x 20 mm) instead of standard photodiodes was used to calibrate absolute irradiance responsivity of the test solar cell (detective area: 156 mm x 156 mm) at wavelength of 650 nm. After such improvement, measurement results using two different methods agree well about 3 % for the large size

  4. Which factors influence MRI-pathology concordance of tumour size measurements in breast cancer?

    Energy Technology Data Exchange (ETDEWEB)

    Rominger, M.; Frauenfelder, T. [University Hospital Zurich, Institute of Diagnostic and Interventional Radiology, Zurich (Switzerland); Berg, D. [Urbankrankenhaus Berlin, Anesthesiology, Berlin (Germany); Ramaswamy, A. [University Hospital Marburg, Pathology, Marburg (Germany); Timmesfeld, N. [Philipps University Marburg, Institute for Medical Biometry and Epidemiology, Marburg (Germany)

    2016-05-15

    To assess MRI-pathology concordance and factors influencing tumour size measurement in breast cancer. MRI tumour size (greatest diameter in anatomical planes (MRI-In-Plane) and greatest diameter along main tumour axis (MRI-MPR)) of 115 consecutive breast lesions (59 invasive lobular carcinoma, 46 invasive ductal carcinoma, and 10 ductal carcinoma in situ) was retrospectively compared to size measured at histopathology (pT size (Path-TNM) and greatest tumour diameter as relevant for excision (Path-Diameter; reference standard)). Histopathological tumour types, preoperative palpability, surgical management, additional high-risk lesions, and BI-RADS lesion type (mass versus non-mass enhancements) were assessed as possible influencing factors. Systematic errors were most pronounced between MRI-MPR and Path-TNM (7.1 mm, limits of agreement (LoA) [-21.7; 35.9]), and were lowest between MRI-In-Plane and Path-Diameter (0.2 mm, LoA [-19.7; 20.1]). Concordance rate of MRI-In-Plane with Path-Diameter was 86 % (97/113), overestimation 9 % (10/113) and underestimation 5 % (6/113); BI-RADS mass lesions were overestimated in 7 % (6/81) versus 41 % (13/32) for non-mass enhancements. On multivariate analysis only BI-RADS lesion type significantly influenced MRI-pathology concordance (p < 0.001). 2/59 (3 %) ILC did not enhance. Concordance rate varies according to the execution of MRI and histopathological measurements. Beyond this only non-mass enhancement significantly predicted discordance. (orig.)

  5. Size of lumbar disc hernias measured using computed tomography and related to sciatic symptoms

    Energy Technology Data Exchange (ETDEWEB)

    Fagerlund, M.K.J.; Thelander, U.; Friberg, S. (Umeaa Univ. Hospital (Sweden). Dept. of Diagnostic Radiology Umeaa Univ. Hospital (Sweden). Dept. of Orthopedics)

    1990-11-01

    The change in the relative size of lumbar disc hernias and its relation to sciatic symptoms was investigated in 30 consecutive patients after conservative treatment of CT verified lumbar disc herniations. CT and clinical examination were performed before the start of therapy (CT1), as well as 3 months (CT2) and 24 months (CT3) after institution of treatment. In each patient the size of the lumbar disc herniation in relation to the size of the spinal canal was measured on identical CT slices and expressed as an index. The disc herniation index decreased markedly from CT1 to CT2 (p<0.001). Between CT2 and CT3 the reduction of the hernias was less pronounced and not significant for hernias located centrally but still significant for intermediate (p=0.03) and lateral (p=0.04) hernias. The degree of sciatic symptoms also decreased markedly between CT1 and CT2 (p=0.001) while no further improvement occurred from CT2 to CT3. There was a significant positive correlation between the improvement from sciatic pain and the reduction in the size of the individual hernia (CT1-CT2 p=0.02, CT2-CT3 p<0.001). Thus, the disc herniation index provided a method to study the anatomic effect of conservative treatment as well as a method to evaluate sciatic symptoms in relation to anatomic changes. (orig.).

  6. The effect of particle size distribution on the design of urban stormwater control measures

    Science.gov (United States)

    Selbig, William R.; Fienen, Michael N.; Horwatich, Judy A.; Bannerman, Roger T.

    2016-01-01

    An urban pollutant loading model was used to demonstrate how incorrect assumptions on the particle size distribution (PSD) in urban runoff can alter the design characteristics of stormwater control measures (SCMs) used to remove solids in stormwater. Field-measured PSD, although highly variable, is generally coarser than the widely-accepted PSD characterized by the Nationwide Urban Runoff Program (NURP). PSDs can be predicted based on environmental surrogate data. There were no appreciable differences in predicted PSD when grouped by season. Model simulations of a wet detention pond and catch basin showed a much smaller surface area is needed to achieve the same level of solids removal using the median value of field-measured PSD as compared to NURP PSD. Therefore, SCMs that used the NURP PSD in the design process could be unnecessarily oversized. The median of measured PSDs, although more site-specific than NURP PSDs, could still misrepresent the efficiency of an SCM because it may not adequately capture the variability of individual runoff events. Future pollutant loading models may account for this variability through regression with environmental surrogates, but until then, without proper site characterization, the adoption of a single PSD to represent all runoff conditions may result in SCMs that are under- or over-sized, rendering them ineffective or unnecessarily costly.

  7. Assessment of air space size characteristics by intercept (chord) measurement: an accurate and efficient stereological approach.

    Science.gov (United States)

    Knudsen, Lars; Weibel, Ewald R; Gundersen, Hans Jørgen G; Weinstein, Felix V; Ochs, Matthias

    2010-02-01

    The mean linear intercept (chord) length (L(m)) is a useful parameter of peripheral lung structure as it describes the mean free distance in the air spaces. It is often misinterpreted as a measure of "alveolar size," and its estimation is fraught with a number of pitfalls. We present two methods for the accurate estimation of L(m): 1) the indirect method, which derives L(m) from the volume-to-surface ratio of air spaces estimated by point counting methods, and 2) the direct method, which uses a set of random intercepts and calculates L(m) from their frequency distribution, for which we introduce a new and accurate method. Both methods are efficient and, with proper precautions, unbiased. The meaning of L(m) is assessed in two different examples. In a physiological study, the effect of different inflation levels is studied, showing that L(m) critically depends on lung inflation. In an experimental study on emphysema-like changes in a genetic mouse model, the effect of heterogeneity of air space size is assessed; these results are obtained partly because of differences in lung volume due to altered recoil in the emphysematous lungs. In conclusion, although L(m) is not a robust parameter of internal lung structure because it crucially depends on lung volume, it is still a valid measure for which accurate and efficient methods are available that yield additional parameters such as size distribution or alveolar surface area.

  8. Measurement of an electronic cigarette aerosol size distribution during a puff

    Directory of Open Access Journals (Sweden)

    Belka Miloslav

    2017-01-01

    Full Text Available Electronic cigarettes (e-cigarettes have become very popular recently because they are marketed as a healthier alternative to tobacco smoking and as a useful tool to smoking cessation. E-cigarettes use a heating element to create an aerosol from a solution usually consisting of propylene glycol, glycerol, and nicotine. Despite the wide spread of e-cigarettes, information about aerosol size distributions is rather sparse. This can be caused by the relative newness of e-cigarettes and by the difficulty of the measurements, in which one has to deal with high concentration aerosol containing volatile compounds. Therefore, we assembled an experimental setup for size measurements of e-cigarette aerosol in conjunction with a piston based machine in order to simulate a typical puff. A TSI scanning mobility particle sizer 3936 was employed to provide information about particle concentrations and sizes. An e-cigarette commercially available on the Czech Republic market was tested and the results were compared with a conventional tobacco cigarette. The particles emitted from the e-cigarette were smaller than those of the conventional cigarette having a CMD of 150 and 200 nm. However, the total concentration of particles from e-cigarette was higher.

  9. Measurement of an electronic cigarette aerosol size distribution during a puff

    Science.gov (United States)

    Belka, Miloslav; Lizal, Frantisek; Jedelsky, Jan; Jicha, Miroslav; Pospisil, Jiri

    Electronic cigarettes (e-cigarettes) have become very popular recently because they are marketed as a healthier alternative to tobacco smoking and as a useful tool to smoking cessation. E-cigarettes use a heating element to create an aerosol from a solution usually consisting of propylene glycol, glycerol, and nicotine. Despite the wide spread of e-cigarettes, information about aerosol size distributions is rather sparse. This can be caused by the relative newness of e-cigarettes and by the difficulty of the measurements, in which one has to deal with high concentration aerosol containing volatile compounds. Therefore, we assembled an experimental setup for size measurements of e-cigarette aerosol in conjunction with a piston based machine in order to simulate a typical puff. A TSI scanning mobility particle sizer 3936 was employed to provide information about particle concentrations and sizes. An e-cigarette commercially available on the Czech Republic market was tested and the results were compared with a conventional tobacco cigarette. The particles emitted from the e-cigarette were smaller than those of the conventional cigarette having a CMD of 150 and 200 nm. However, the total concentration of particles from e-cigarette was higher.

  10. A method for crack sizing using Laser Doppler Vibrometer measurements of Surface Acoustic Waves.

    Science.gov (United States)

    Longo, Roberto; Vanlanduit, Steve; Vanherzeele, Joris; Guillaume, Patrick

    2010-01-01

    The goal of non-destructive testing (NDT) is to determine the position and size of structural defects, in order to measure the quality and evaluate the safety of building materials. Most NDT techniques are rather complex, however, requiring specialized knowledge. In this article, we introduce an experimental method for crack detection that uses Surface Acoustic Waves (SAWs) and optical measurements. The method is tested on a steel beam engraved with slots of known depth. A simple model to determine the cracks size is also proposed. At the end of the article, we describe a possible application: fatigue crack sizing on a damaged slat track. This technique represents a first step toward a better understanding of the crack growth, especially in its early stages (preferably when the cracks can still be repaired) and when it is possible to assume a linear propagation of the crack front. The ultimate goal of this research program is to develop a useful method of monitoring aircraft components during fatigue testing.

  11. Chrominance to dimension: a real-time method for measuring the size of single gold nanoparticles.

    Science.gov (United States)

    Jing, Chao; Gu, Zhen; Ying, Yi-Lun; Li, Da-Wei; Zhang, Lei; Long, Yi-Tao

    2012-05-15

    Noble metal nanoparticles have excellent optical and chemical properties and are widely used in optics, sensors, and biomedicines. The inherent characteristics of metal nanoparticles, particularly their size, play important roles in their applications. The ability to readily measure the size of single nanomaterials on-site is crucial to the rapid development of single-particle sensors. In this study, we developed a facile and real-time method for estimating the diameter of single gold nanoparticles (GNPs) that range from 35 to 110 nm in diameter; this technique uses the chrominance of the GNP's plasmon resonance scattering light that is captured by a dark-field microscope (DFM). The RGB (three primary colors, red, green, and blue) chrominance information from the dark-field image can be directly converted into the diameters of the GNPs using the relationship between the particle size and the scattering light peak wavelength; this conversion was carried out using Matlab program based on an RGB-To-Wavelength (RTW) process. This approach is more convenient, less time-consuming, and enables observation under arbitrary conditions compared to the scanning electron microscopy (SEM) technique. The differences between the diameters of the GNPs that were calculated using this method and those that were measured using SEM were less than 5 nm. The RTW method has also been applied in the monitoring of the refractive index of the media surrounding the GNPs, and their dynamic acting within cells in real-time.

  12. Word knowledge in the crowd: Measuring vocabulary size and word prevalence in a massive online experiment.

    Science.gov (United States)

    Keuleers, Emmanuel; Stevens, Michaël; Mandera, Paweł; Brysbaert, Marc

    2015-01-01

    We use the results of a large online experiment on word knowledge in Dutch to investigate variables influencing vocabulary size in a large population and to examine the effect of word prevalence-the percentage of a population knowing a word-as a measure of word occurrence. Nearly 300,000 participants were presented with about 70 word stimuli (selected from a list of 53,000 words) in an adapted lexical decision task. We identify age, education, and multilingualism as the most important factors influencing vocabulary size. The results suggest that the accumulation of vocabulary throughout life and in multiple languages mirrors the logarithmic growth of number of types with number of tokens observed in text corpora (Herdan's law). Moreover, the vocabulary that multilinguals acquire in related languages seems to increase their first language (L1) vocabulary size and outweighs the loss caused by decreased exposure to L1. In addition, we show that corpus word frequency and prevalence are complementary measures of word occurrence covering a broad range of language experiences. Prevalence is shown to be the strongest independent predictor of word processing times in the Dutch Lexicon Project, making it an important variable for psycholinguistic research.

  13. A precise few-nucleon size difference by isotope shift measurements of helium

    Science.gov (United States)

    Rezaeian, Nima Hassan

    We perform high precision measurements of an isotope shift between the two stable isotopes of helium. We use laser excitation of the 23 S1 -- 23P0 transition at 1083 .... in a metastable beam of 3He and 4He atoms. A newly developed tunable laser frequency selector along with our previous electro-optic frequency modulation technique provides extremely reliable, adaptable, and precise frequency and intensity control. The intensity control contributes negligibly to overall experimental uncertainty by selecting (t selection internal and external consistency checks, we are able to obtain results consistent with the best previous measurements, but with substantially improved precision. Our measurement of the 23S 1 -- 23P0 isotope shift between 3He and 4He is 31 097 535.2 (5)kHz. The most recent theoretic calculation combined with this measuremen. yields a new determination for nuclear size differences between 3He and 4He: Deltarc = 0.292 6 (1)exp (8)th(52)expfm, with a precision of less than a part in 104 coming from the experimental uncertainty (first parenthesis), and a part in 10 3 coming from theory. This value is consistent with electron scattering measurement, but a factor of 10 more precise. It is inconsistent (4 sigma) with a recent isotope shift measurement on another helium transition (2 1S0 -- 23 S1). Comparisons with ongoing muonic helium measurements may provide clues to the origin of what is currently called the proton puzzle: electronic and muonic measurements of the proton size do not agree. In the future, the experimental improvements described here can be used for higher precision tests of atomic theory and quantum electrodynamics, as well as an important atomic physics source of the fine structure constant.

  14. In vivo lateral blood flow velocity measurement using speckle size estimation.

    Science.gov (United States)

    Xu, Tiantian; Hozan, Mohsen; Bashford, Gregory R

    2014-05-01

    In previous studies, we proposed blood measurement using speckle size estimation, which estimates the lateral component of blood flow within a single image frame based on the observation that the speckle pattern corresponding to blood reflectors (typically red blood cells) stretches (i.e., is "smeared") if blood flow is in the same direction as the electronically controlled transducer line selection in a 2-D image. In this observational study, the clinical viability of ultrasound blood flow velocity measurement using speckle size estimation was investigated and compared with that of conventional spectral Doppler of carotid artery blood flow data collected from human patients in vivo. Ten patients (six male, four female) were recruited. Right carotid artery blood flow data were collected in an interleaved fashion (alternating Doppler and B-mode A-lines) with an Antares Ultrasound Imaging System and transferred to a PC via the Axius Ultrasound Research Interface. The scanning velocity was 77 cm/s, and a 4-s interval of flow data were collected from each subject to cover three to five complete cardiac cycles. Conventional spectral Doppler data were collected simultaneously to compare with estimates made by speckle size estimation. The results indicate that the peak systolic velocities measured with the two methods are comparable (within ±10%) if the scan velocity is greater than or equal to the flow velocity. When scan velocity is slower than peak systolic velocity, the speckle stretch method asymptotes to the scan velocity. Thus, the speckle stretch method is able to accurately measure pure lateral flow, which conventional Doppler cannot do. In addition, an initial comparison of the speckle size estimation and color Doppler methods with respect to computational complexity and data acquisition time indicated potential time savings in blood flow velocity estimation using speckle size estimation. Further studies are needed for calculation of the speckle stretch method

  15. Single-shot beam size measurements using visible-light interferometry at CESR

    Energy Technology Data Exchange (ETDEWEB)

    Wang, S.T., E-mail: sw565@cornell.edu [Cornell Laboratory for Accelerator-based Science and Education, Cornell University, Ithaca, NY 14853 (United States); Holtzapple, R. [Physics Department, California Polytechnic State University, San Luis Obispo, CA 93407 (United States); Rubin, D.L. [Cornell Laboratory for Accelerator-based Science and Education, Cornell University, Ithaca, NY 14853 (United States)

    2017-03-01

    A new primary mirror for a visible-light beam size monitor (vBSM) was designed and installed in the Cornell Electron-Positron Storage Ring (CESR). The vertical angular acceptance of the mirror was doubled to allow double-slit interferometry with large slit separation (>12 mm). In addition, the diffraction associated with the first generation mirror has been eliminated. The resolution of the vertical beam size measurements has been dramatically improved but is ultimately limited by the beam motion. Two fast-response detectors, a Photomultiplier Tube (PMT) array and a gated camera, were employed to study the beam motion. The advantages and limitations of both devices are discussed in this paper. The gated camera was also used to measure single-shot beam width and motion of each bunch in a multi-bunch train. We measured significantly more horizontal motion of electron as compared to positron bunch trains in otherwise identical machine condition. This difference may be a signature for the difference between electron cloud build-up for positron bunch trains versus ions effects characteristic of electron bunch trains. - Highlights: • A new extraction mirror for synchrotron radiation was designed and installed in CESR. • The sensitivity of interferometer was increased and the diffraction effect was eliminated. • Two fast-response detectors were employed to study the effect of beam motion. • First time single-shot bunch-by-bunch horizontal beam size measurements using interferometry was observed from gated camera. • The difference in single bunch horizontal dynamics was observed between a positron and an electron train.

  16. 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.

  17. Determination of dust aerosol particle size at Gale Crater using REMS UVS and Mastcam measurements

    Science.gov (United States)

    Vicente-Retortillo, Álvaro; Martínez, Germán. M.; Renno, Nilton O.; Lemmon, Mark T.; de la Torre-Juárez, Manuel

    2017-04-01

    We calculate the seasonal and interannual variation in dust aerosol particle size above Gale Crater during the first 1413 Martian solar days (sols = 24.6 h) of the Mars Science Laboratory mission. Measurements of UV radiation made by the Rover Environmental Monitoring Station in combination with atmospheric opacities retrieved from the Mastcam instrument are used for the calculations. Our results indicate that the dust effective radius varies significantly with season, ranging from 0.6 μm during the low opacity season (Ls = 60°-140°) to 2 μm during the high opacity season (Ls = 180°-360°). Our results suggest that Gale Crater is affected by dust events of high aerosol content originated at various distances from it. Our results improve the accuracy of estimations of ultraviolet radiation fluxes at the Martian surface. Moreover, our results have important implications because the lifetime of suspended dust and its ability to nucleate clouds are affected by particle size.

  18. Measurement of the environmental broadband electromagnetic waves in a mid-size European city.

    Science.gov (United States)

    Fernández-García, R; Gil, I

    2017-10-01

    In this paper, the level of exposure to broadband radiofrequency electromagnetic field in a mid-size European city was evaluated in accordance with the International Commission on Non-ionizing Radiation Protection guidelines from 1998. With the aim to analyse all the potential electromagnetic waves present in the city up to 18GHz, a total of 271 locations distributed along Terrassa (Spain) have been measured. To show the results in an easy-to-interpret way by the citizen, the results have been represented in a set of raster maps. The measurement results obtained showed that the electromagnetic wave measured in all broadband frequency range along the city is much lower than the safety level according to the international regulations for both public and occupational sectors. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Effects of Finite Probe Size on Self-Affine Roughness Measurements

    Science.gov (United States)

    Lechenault, F.; Pallares, G.; George, M.; Rountree, C.; Bouchaud, E.; Ciccotti, M.

    2010-01-01

    The roughness of fracture surfaces exhibits self-affinity for a wide variety of materials and loading conditions. The universality and the range of scales over which this regime extends are still debated. The topography of these surfaces is however often investigated with a finite contact probe. In this case, we show that the correlation function of the roughness can only be measured down to a length scale Δxc which depends on the probe size R, the Hurst exponent ζ of the surface and its topothesy l, and exhibits spurious behavior at smaller scales. First, we derive the dependence of Δxc on these parameters from a simple scaling argument. Then, we verify this dependence numerically. Finally, we establish the relevance of this analysis from AFM measurements on an experimental glass fracture surface and provide a metrological procedure for roughness measurements.

  20. Quantitative measurement of the nanoparticle size and number concentration from liquid suspensions by atomic force microscopy.

    Science.gov (United States)

    Baalousha, M; Prasad, A; Lead, J R

    2014-05-01

    Microscopy techniques are indispensable to the nanoanalytical toolbox and can provide accurate information on the number size distribution and number concentration of nanoparticles (NPs) at low concentrations (ca. ppt to ppb range) and small sizes (ca. microscopy techniques are limited by the traditional sample preparation based on drying a small volume of suspension of NPs on a microscopy substrate. This method is limited by low recovery of NPs (ca. atomic force microscopy (AFM) that overcomes the above-mentioned shortcomings and allows full recovery and representativeness of the NPs under consideration by forcing the NPs into the substrate via ultracentrifugation and strongly attaches the NPs to the substrate by surface functionalization of the substrate or by adding cations to the NP suspension. The high efficiency of the analysis is demonstrated by the uniformity of the NP distribution on the substrate (that is low variability between the number of NPs counted on different images on different areas of the substrate), the high recovery of the NPs up to 71%) and the good correlation (R > 0.95) between the mass and number concentrations. Therefore, for the first time, we developed a validated quantitative sampling technique that enables the use of the full capabilities of microscopy tools to quantitatively and accurately determine the number size distribution and number concentration of NPs at environmentally relevant low concentrations (i.e. 0.34-100 ppb). This approach is of high environmental relevance and can be applied widely in environmental nanoscience and nanotoxicology for (i) measuring the number concentration dose in nanotoxicological studies and (ii) accurately measuring the number size distribution of NPs; both are key requirements for the implementation of the European Commission recommendation for definition of nanomaterials.

  1. Beam Size Measurement by Optical Diffraction Radiation and Laser System for Compton Polarimeter

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Chuyu [Peking Univ., Beijing (China)

    2012-12-31

    Beam diagnostics is an essential constituent of any accelerator, so that it is named as "organs of sense" or "eyes of the accelerator." Beam diagnostics is a rich field. A great variety of physical effects or physical principles are made use of in this field. Some devices are based on electro-magnetic influence by moving charges, such as faraday cups, beam transformers, pick-ups; Some are related to Coulomb interaction of charged particles with matter, such as scintillators, viewing screens, ionization chambers; Nuclear or elementary particle physics interactions happen in some other devices, like beam loss monitors, polarimeters, luminosity monitors; Some measure photons emitted by moving charges, such as transition radiation, synchrotron radiation monitors and diffraction radiation-which is the topic of the first part of this thesis; Also, some make use of interaction of particles with photons, such as laser wire and Compton polarimeters-which is the second part of my thesis. Diagnostics let us perceive what properties a beam has and how it behaves in a machine, give us guideline for commissioning, controlling the machine and indispensable parameters vital to physics experiments. In the next two decades, the research highlight will be colliders (TESLA, CLIC, JLC) and fourth-generation light sources (TESLA FEL, LCLS, Spring 8 FEL) based on linear accelerator. These machines require a new generation of accelerator with smaller beam, better stability and greater efficiency. Compared with those existing linear accelerators, the performance of next generation linear accelerator will be doubled in all aspects, such as 10 times smaller horizontal beam size, more than 10 times smaller vertical beam size and a few or more times higher peak power. Furthermore, some special positions in the accelerator have even more stringent requirements, such as the interaction point of colliders and wigglor of free electron lasers. Higher performance of these accelerators increases the

  2. Single-shot beam size measurements using visible-light interferometry at CESR

    Science.gov (United States)

    Wang, S. T.; Holtzapple, R.; Rubin, D. L.

    2017-03-01

    A new primary mirror for a visible-light beam size monitor (vBSM) was designed and installed in the Cornell Electron-Positron Storage Ring (CESR). The vertical angular acceptance of the mirror was doubled to allow double-slit interferometry with large slit separation (>12 mm). In addition, the diffraction associated with the first generation mirror has been eliminated. The resolution of the vertical beam size measurements has been dramatically improved but is ultimately limited by the beam motion. Two fast-response detectors, a Photomultiplier Tube (PMT) array and a gated camera, were employed to study the beam motion. The advantages and limitations of both devices are discussed in this paper. The gated camera was also used to measure single-shot beam width and motion of each bunch in a multi-bunch train. We measured significantly more horizontal motion of electron as compared to positron bunch trains in otherwise identical machine condition. This difference may be a signature for the difference between electron cloud build-up for positron bunch trains versus ions effects characteristic of electron bunch trains.

  3. A study on measurements of local ice pressure for ice breaking research vessel “ARAON” at the Amundsen Sea

    Directory of Open Access Journals (Sweden)

    Yong-Hyeon Kwon

    2015-05-01

    Full Text Available In this study, a local ice pressure prediction has been conducted by using measured data from two ice breaking tests that was conducted for a relatively big ice floe at Amundsen Sea in the Antarctica from January 31 to March 30 2012. The symmetry of load was considered by attaching strain gauges on the same sites inside the shell plating of ship at the port and the starboard sides in the bow thrust room. Using measured strain data, after the ice pressure was converted by the influence coefficient method and the direct method, the two values were found to be similar.

  4. Prosopomorphic vessels from Moesia Superior

    Directory of Open Access Journals (Sweden)

    Nikolić Snežana

    2008-01-01

    Full Text Available The prosopomorphic vessels from Moesia Superior had the form of beakers varying in outline but similar in size. They were wheel-thrown, mould-made or manufactured by using a combination of wheel-throwing and mould-made appliqués. Given that face vessels are considerably scarcer than other kinds of pottery, more than fifty finds from Moesia Superior make an enviable collection. In this and other provinces face vessels have been recovered from military camps, civilian settlements and necropolises, which suggests that they served more than one purpose. It is generally accepted that the faces-masks gave a protective role to the vessels, be it to protect the deceased or the family, their house and possessions. More than forty of all known finds from Moesia Superior come from Viminacium, a half of that number from necropolises. Although tangible evidence is lacking, there must have been several local workshops producing face vessels. The number and technological characteristics of the discovered vessels suggest that one of the workshops is likely to have been at Viminacium, an important pottery-making centre in the second and third centuries.

  5. Particle Morphology and Size Results from the Smoke Aerosol Measurement Experiment-2

    Science.gov (United States)

    Urban, David L.; Ruff, Gary A.; Greenberg, Paul S.; Fischer, David; Meyer, Marit; Mulholland, George; Yuan, Zeng-Guang; Bryg, Victoria; Cleary, Thomas; Yang, Jiann

    2012-01-01

    Results are presented from the Reflight of the Smoke Aerosol Measurement Experiment (SAME-2) which was conducted during Expedition 24 (July-September 2010). The reflight experiment built upon the results of the original flight during Expedition 15 by adding diagnostic measurements and expanding the test matrix. Five different materials representative of those found in spacecraft (Teflon, Kapton, cotton, silicone rubber and Pyrell) were heated to temperatures below the ignition point with conditions controlled to provide repeatable sample surface temperatures and air flow. The air flow past the sample during the heating period ranged from quiescent to 8 cm/s. The smoke was initially collected in an aging chamber to simulate the transport time from the smoke source to the detector. This effective transport time was varied by holding the smoke in the aging chamber for times ranging from 11 to 1800 s. Smoke particle samples were collected on Transmission Electron Microscope (TEM) grids for post-flight analysis. The TEM grids were analyzed to observe the particle morphology and size parameters. The diagnostics included a prototype two-moment smoke detector and three different measures of moments of the particle size distribution. These moment diagnostics were used to determine the particle number concentration (zeroth moment), the diameter concentration (first moment), and the mass concentration (third moment). These statistics were combined to determine the diameter of average mass and the count mean diameter and, by assuming a log-normal distribution, the geometric mean diameter and the geometric standard deviations can also be calculated. Overall the majority of the average smoke particle sizes were found to be in the 200 nm to 400 nm range with the quiescent cases producing some cases with substantially larger particles.

  6. An automated method for accurate vessel segmentation

    Science.gov (United States)

    Yang, Xin; Liu, Chaoyue; Le Minh, Hung; Wang, Zhiwei; Chien, Aichi; (Tim Cheng, Kwang-Ting

    2017-05-01

    Vessel segmentation is a critical task for various medical applications, such as diagnosis assistance of diabetic retinopathy, quantification of cerebral aneurysm’s growth, and guiding surgery in neurosurgical procedures. Despite technology advances in image segmentation, existing methods still suffer from low accuracy for vessel segmentation in the two challenging while common scenarios in clinical usage: (1) regions with a low signal-to-noise-ratio (SNR), and (2) at vessel boundaries disturbed by adjacent non-vessel pixels. In this paper, we present an automated system which can achieve highly accurate vessel segmentation for both 2D and 3D images even under these challenging scenarios. Three key contributions achieved by our system are: (1) a progressive contrast enhancement method to adaptively enhance contrast of challenging pixels that were otherwise indistinguishable, (2) a boundary refinement method to effectively improve segmentation accuracy at vessel borders based on Canny edge detection, and (3) a content-aware region-of-interests (ROI) adjustment method to automatically determine the locations and sizes of ROIs which contain ambiguous pixels and demand further verification. Extensive evaluation of our method is conducted on both 2D and 3D datasets. On a public 2D retinal dataset (named DRIVE (Staal 2004 IEEE Trans. Med. Imaging 23 501-9)) and our 2D clinical cerebral dataset, our approach achieves superior performance to the state-of-the-art methods including a vesselness based method (Frangi 1998 Int. Conf. on Medical Image Computing and Computer-Assisted Intervention) and an optimally oriented flux (OOF) based method (Law and Chung 2008 European Conf. on Computer Vision). An evaluation on 11 clinical 3D CTA cerebral datasets shows that our method can achieve 94% average accuracy with respect to the manual segmentation reference, which is 23% to 33% better than the five baseline methods (Yushkevich 2006 Neuroimage 31 1116-28; Law and Chung 2008

  7. Nano to micro particle size distribution measurement in the fluid by interactive force apparatus for fine particle processing.

    Science.gov (United States)

    Fujita, Toyohisa; Dodbiba, Gjergj; Okaya, Katsunori; Matsuo, Seiji; Wang, Li Pang; Onda, Kana; Otsuki, Akira

    2013-12-01

    The direct measurement of fine particles size distribution of dispersions or coagulations in liquid is important for water purification, fine particles separation for recycling and mineral processing, as well as the new material production. The nano to micro particle size is usually measured by light scattering method; however, it is difficult to measure at high concentration of suspension. Here, a novel dynamical method by using the interactive force measurement between particles in liquid under electric field is used for measuring distribution of fine particle. Three types of nano to submicron particles, that is well-dispersed nano particles, coagulated nano particles and settled submicron particles, have been measured by interactive force measurement method. The particle size distributions are compered with the size distributions of dried particles measured by TEM or SEM. The well-dispersed nano particle size distribution by interactive force measurement is influenced by the nano size surfactant micelles. The size distribution of coagulated nano particles in water is larger than the result by TEM. On the other hand, the submicron nickel particle size distribution is similar with the one analyzed by SEM.

  8. Concentration and size distribution data of silicon nitride nanoparticles measured using nanoparticle tracking analysis.

    Science.gov (United States)

    Lal, Saurabh; Hall, Richard M; Tipper, Joanne L

    2017-12-01

    This article refers to the paper "A novel method for isolation and recovery of ceramic nanoparticles and metal wear debris from serum lubricants at ultra-low wear rates" (Lal et al., 2016) [1] and describes the concentration and size distribution data of silicon nitride nanoparticles measured using nanoparticle tracking analysis (NTA). A NanoSight LM10 instrument was used to capture the video data of silicon nitride nanoparticles moving under Brownian motion in the water. The video data was then analyzed using the NanoSight NTA software. This article also describes a methodology for calculating the percentage recovery of a nanoparticle isolation process.

  9. Measurement of bubble size distribution in protein foam fractionation column using capillary probe with photoelectric sensors.

    Science.gov (United States)

    Du, L; Ding, Y; Prokop, A; Tanner, R D

    2001-01-01

    Bubble size is a key variable for predicting the ability to separate and concentrate proteins in a foam fractionation process. It is used to characterize not only the bubble-specific interfacial area but also coalescence of bubbles in the foam phase. This article describes the development of a photoelectric method for measuring the bubble size distribution in both bubble and foam columns for concentrating proteins. The method uses a vacuum to withdraw a stream of gas-liquid dispersion from the bubble or foam column through a capillary tube with a funnel-shaped inlet. The resulting sample bubble cylinders are detected, and their lengths are calculated by using two pairs of infrared photoelectric sensors that are connected with a high-speed data acquisition system controlled by a microcomputer. The bubble size distributions in the bubble column 12 and 1 cm below the interface and in the foam phase 1 cm above the interface are obtained in a continuous foam fractionation process for concentrating ovalbumin. The effects of certain operating conditions such as the feed protein concentration, superficial gas velocity, liquid flow rate, and solution pH are investigated. The results may prove to be helpful in understanding the mechanisms controlling the foam fractionation of proteins.

  10. Validation and Generalization of a Method for Precise Size Measurements of Metal Nanoclusters on Supports

    Energy Technology Data Exchange (ETDEWEB)

    Reed, B W; Morgan, D G; Okamoto, N L; Kulkarni, A; Gates, B C; Browning, N D

    2008-09-16

    We recently described a data analysis method for precise ({approx}0.1 {angstrom} random error in the mean for a 200 kV instrument with a 3 {angstrom} FWHM probe size) size measurements of small clusters of heavy metal atoms on supports as imaged in a scanning transmission electron microscope, including an experimental demonstration using clusters that were primarily triosmium or decaosmium. The method is intended for low signal-to-noise ratio images of radiation-sensitive samples. We now present a detailed analysis, including a generalization to address issues of particle anisotropy and biased orientation distributions. In the future, this analysis should enable extraction of shape as well as size information, up to the noise-defined limit of information present in the image. We also present results from an extensive series of simulations designed to determine the method's range of applicability and expected performance in realistic situations. The simulations reproduce the experiments quite accurately, enabling a correction of systematic errors so that only the {approx}0.1 {angstrom} random error remains. The results are very stable over a wide range of parameters. We introduce a variation on the method with improved precision and stability relative to the original version, while also showing how simple diagnostics can test whether the results are reliable in any particular instance.

  11. Development of a global rainbow refractometry technique to measure the temperature of spray droplets in a large containment vessel

    Science.gov (United States)

    Lemaitre, P.; Porcheron, E.; Grehan, G.; Bouilloux, L.

    2006-06-01

    In order to study the heat and mass transfers between a spray of droplets and the atmosphere in thermal-hydraulics conditions representative of a severe accident in a Pressurized Water Nuclear Reactor, the French Institute for Radioprotection and Nuclear Safety (IRSN) developed the TOSQAN facility. The present paper presents the development and the quantification of an optical diagnostic, global rainbow refractometry, in order to measure falling droplet temperature.

  12. Diamagnetic measurements in the STOR-M tokamak by a flux loop system exterior to the vacuum vessel

    Science.gov (United States)

    Trembach, Dallas; Xiao, Chijin; Dreval, Mykola; Hirose, Akira

    2009-05-01

    Diamagnetic measurements of poloidal beta have been performed in the STOR-M tokamak by a flux loop placed exterior to the vacuum chamber with compensation for the vacuum toroidal field using a nonenclosing coplanar coil, and vibrational compensation from auxiliary coils. It was found that in STOR-M conditions (20% toroidal magnetic field decay over discharge) there is significant influence on the diamagnetic flux measurements from strong residual signals, presumably from image currents being induced by the toroidal field coils, requiring further compensation. A blank (nonplasma) shot is used specifically to eliminate the residual component which is not proportional to the toroidal magnetic field. Data from normal Ohmic discharge operation is presented and calculations of poloidal beta from coil data (βθ˜0.5) is found to be in reasonable agreement with the values of poloidal beta obtained from measurements of electron density and Spitzer temperature with neoclassical corrections for trapped electrons. Contributions present in the blank shot (residual) signal and the limitations of this method are discussed.

  13. Optofluidics based lab-on-chip device for in situ measurement of mean droplet size and droplet size distribution of an emulsion

    Science.gov (United States)

    Shivhare, P. K.; Prabhakar, A.; Sen, A. K.

    2017-03-01

    There is an urgent need for a cost-effective, precise, and portable device for rapid and in situ measurement of the critical properties of an emulsion. Here, we report the development of such an optofluidic device for the measurement of mean droplet size ({{d}\\text{Mean}} ) and droplet size distribution (DSD) of a water-in-oil emulsion. We formulated and detected water-in-oil droplets of much smaller dimensions (15 μ \\text{m} ) compared to the detection of larger droplets or plugs (100 μ \\text{m} to 300 μ \\text{m} ) reported in the literature, employing a cost effective and portable in-house built optical detection system. Use of the device for the measurement of the frequency of droplets from an on-chip droplet generator is demonstrated and validated using microscopy with excellent accuracy (2%). In addition, we provide some insight into the relatively high uncertainty in the collected signal in case of smaller droplets. The droplet size {{d}\\text{D}} is characterized in terms of forward scatter signal {{v}\\text{FSC}} and residence time τ . We further argue that normalized residence time τ of droplets in the detection zone which correlates linearly with droplet size {{d}\\text{D}} is a better parameter to measure droplet size {{d}\\text{D}} , compared to the forward scatter signal {{v}\\text{FSC}} which correlates nonlinearly with {{d}\\text{D}} . Finally, the device is used to count the number of droplets of different size to predict {{d}\\text{Mean}} and DSD of emulsions. The results were compared with that obtained from traditional microscopy and a very good match (10-13%) was found, in contrast to previously reported non-portable off-chip methods that are 20-44% accurate. Thus, the reported device possesses high potential for accurate measurement of {{d}\\text{Mean}} and DSD of emulsions in practical applications.

  14. Plastic Bonded Explosive (PBX) Particle Size Distribution (PSD) Measurements Using an Image Analysis System

    Energy Technology Data Exchange (ETDEWEB)

    Sullivan, Gregg K. [Univ. of Wyoming, Laramie, WY (United States)

    2003-06-01

    The slurry process for producing plastic bonded explosives (PBX) has been used for many years. However, until recently the mechanisms involved have not been studied quantitatively to determine the effects of the various control variables. Recently, the effects of operating variables on the final product have been studied; however, no attempt was made to measure particle growth during the slurry process. This study applies an image analysis tool to measure particle size distributions (PSDs) during the slurry process to produce PBX 9501, a specific formulation used in nuclear weapons. The observed PBX 9501 slurry behavior leads away from the typical population balance description of agglomeration, that is, a discrete particle-particle coalescence mechanism. The behavior observed in these experiments indicates that the initial state of the system contains a number of smaller particles clustered together. The cluster then coalesces into a large particle as solvent is removed and the slurry continuously mixed. Other small fragments are picked up and a relatively small amount of growth is observed. A mass transfer model adequately describes solvent removal, and an empirical model is developed to describe the growth behavior in terms of measured process variables. The image system is applied to dried molding powders. The PSD measurement results of the PBX 9501 library lots, historic samples set aside as PBX 9501 lots were accepted from the manufacturer, are also discussed and analyzed. A correlation analysis was conducted to find relationships between the measured PSD and other properties such as bulk density and pressed densities. While no significant correlation was found between the measured PSD and averaged bulk densities for the library lots, significant correlations are found between the measured PSD and pressed density. The final part of the study was to scale-up the PSD measurement capability. Since the large-scale processes are not yet operational, this work

  15. Scoping Experiments for Pressure Drop Measurement for the Ex-Vessel Debris Bed Coolability in Severe Accidents

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jin Ho; Kim, Eun Ho; Park, Hyun Sun [POSTECH, Pohang (Korea, Republic of); Kim, Moo Hwan [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of); Ma, Weimin; Bechta, Sevostian [Nuclear Power Safety Division, Stockholm (Sweden)

    2014-05-15

    To ensure the long-term cooling of corium in the reactor cavity, it is important to ensure the coolant ingression into the internally heat generated corium debris bed governed by pressure drop in the porous media. According to the previous investigations on molten fuel-coolant interactions (FCIs) experiments, the debris beds are expected to form channels in the bed due to intensive boiling and flow. And also, it was found that quenched particulate debris bed was composed of multi-sized (0∼10 mm), irregular shape particles and it has a micro/macro inhomogeneity such as axially and radially stratified debris bed, where a layer of smaller particles covers the main bed part. In this particulate debris bed with the internal heat generation by decay heat, not only co- but also counter-current two-phase flow may be occurred by the water inflow through sides of bed combined with steam outflow to top of bed. To investigate the effect of each characteristics of heterogeneous debris bed expected in real severe accident scenarios on pressure drop with various conditions, an experimental facility called as PICASSO (Pressure drop Investigation and Coolability ASSessment through Observation) facility was constructed. With the experimental facility, the scoping test was conducted as injecting upward air flow into the bottom of particle bed composed of 2 mm, 5 mm spherical SUJ-2 balls respectively, and the experimental data compared with Ergun equation. As a result of the single phase flow experiment using air, Ergun equation predicts the experimental data for the spherical particles with the diameter of 2 mm and 5 mm with a mean deviation of 14.62 %.

  16. Size-fractionated measurement of coarse black carbon particles in deposition samples

    Science.gov (United States)

    Schultz, E.

    In a 1-year field study, particle deposition flux was measured by transparent collection plates. Particle concentration was simultaneously measured with a cascade impactor. Microscopic evaluation of deposition samples provided the discrimination of translucent (mineral or biological) and black carbon particles, i.e. soot agglomerates, fly-ash cenospheres and rubber fragments in the size range from 3 to 50 μm. The deposition samples were collected in two different sampling devices. A wind- and rain-shielded measurement was achieved in the Sigma-2 device. Dry deposition data from this device were used to calculate mass concentrations of the translucent and the black particle fraction separately, approximating particle deposition velocity by Stokes' settling velocity. In mass calculations an error up to 20% has to be considered due to assumed spherical shape and unit density for all particles. Within the limitations of these assumptions, deposition velocities of the distinguished coarse particles were calculated. The results for total particulate matter in this range are in good agreement with those from impactor measurement. The coarse black carbon fraction shows a reduced deposition velocity in comparison with translucent particles. The deviation depends on precipitation amount. Further measurements and structural investigations of black carbon particles are in preparation to verify these results.

  17. A Beam Gas Vertex detector for beam size measurement in the LHC

    CERN Document Server

    Hopchev, P; Barschel, C; Bravin, E; Bregliozzi, G; Chritin, N; Dehning, B; Ferro-Luzzi, M; Gaspar, C; Giovannozzi, M; van Herwijnen, E; Jacobsson, R; Jensen, L; Rhodri Jones, O; Jurado, N; Kain, V; Kuhn, M; Luthi, B; Magagnin, P; Matev, R; Neufeld, N; Panman, J; Rihl, M; Salustino Guimaraes, V; Salvant, B; Veness, R; Bay, A; Blanc, F; Gianì, S; Haefeli, G; Nakada, T; Rakotomiaramanana, B; Schneider, O; Tobin, M; Veyrat, Q; Xu, Z; Greim, R; Karpinski, W; Kirn, T; Schael, S; Schultz von Dratzig, A; Schwering, G; Wlochal, M

    2014-01-01

    The Beam Gas Vertex (BGV) detector is foreseen as a possible non-invasive beam size measurement instrument for the LHC and its luminosity upgrade. This technique is based on the reconstruction of beam-gas interaction vertices, where the charged particles produced in inelastic beam-gas interactions are measured with high-precision tracking detectors. The design studies and expected performance of the currently developed BGV prototype will be presented with an overview given of the associated vacuum, detector and readout systems. A brief description will be given of the BGV Monte Carlo simulation application, which is based on the LHCb computing framework (Gaudi) and allows simulation studies to be performed and online event reconstruction algorithms to be developed.

  18. Key aspects in the implementation of algorithms for digital processors in velocity and size measurements

    Science.gov (United States)

    Troolin, Dan; Evenstad, Jim; Lai, Wing; Fluid Mechanics research instruments Team

    2017-11-01

    Digital signal processing techniques are used to extract accurate flow and size information in complex and difficult measuring situations. Some of the key aspects that are vital to the performance of signal processors are discussed. Limitations of theoretical approach in evaluating the processing techniques are outlined. Simulations have been carried out to examine the influence of some of the parameters not covered by the analytical approach. The robustness of the auto-correlation technique with quadrature mixing is demonstrated through simulations. The advantage of adapting advantage of adapting a processing technique to be well suited to the nature of the signal, as well as the importance of pre-processing or conditioning the input to be properly positioned for the algorithm are pointed out. Finally the benefits of the auto-correlation technique are proven through experimental measurements.

  19. Simulation test of aerosol generation from vessels in the pre-treatment system of fuel reprocessing

    Energy Technology Data Exchange (ETDEWEB)

    Fujine, Sachio; Kitamura, Koichiro; Kihara, Takehiro [Japan Atomic Energy Research Institute (JAERI), Ibaraki-ken (Japan)

    1997-08-01

    Aerosol concentration and droplet size are measured in off-gas of vessel under various conditions by changing off-gas flow rate, stirring air flow rate, salts concentration and temperature of nitrate solution. Aerosols are also measured under evaporation and air-lift operation. 4 refs., 6 figs.

  20. Relationships between aggregates size classes and SOC content using aggregate settling velocity measurements in interrill areas

    Science.gov (United States)

    Quijano, Laura; Kuhn, Nikolaus J.; Navas, Ana

    2017-04-01

    Soil aggregate stability is one of the main factors of soil physics and structure. Formation and stabilization of soil aggregates facilitates soil carbon sequestration and reduces the susceptibility of soil to erosion. The gain or loss of C in agricultural systems is largely influenced by aggregate-associated soil organic carbon that affects the settling velocity and C content of soils. Settling velocity measurements are useful to provide direct information on soil aggregate size distribution that can be used as indicators of the potential soil erodibility. This study aims to analyze the effect of settling velocity on soil aggregate dynamics and the relationships between the particle size distributions and the associated carbon in a cultivated field of typical Mediterranean agroecosystems in mountain landscapes. Calcisol topsoil samples (n=10) were collected in an interrill area within the field at two contrasting slope positions (i.e. upslope and downslope). Furthermore, a total of ten Calcisol soil samples were collected in an adjacent area under forest vegetation cover and stable conditions. According to Stokes's Law, the fine soil fraction 0.045, 0.045-0.015, 0.015-0.003, 0.003-0.001 and soil aggregation by the lower proportion of macroaggregates compared to forest soils. Moreover, it was found a preferential transport of fine particles from upslope to downslope during interrill erosion processes. In this study, settling velocity measurements provide a useful tool for assessing changes in soil aggregation under different land uses and for identifying the relationship between aggregates size classes and SOC content in Mediterranean agroecosystems.

  1. Particle Size Distributions Measured in the B757 Engine Plume During EXCAVATE

    Science.gov (United States)

    Sanders, Terry; Penko, Paul; Rivera, Monica; Culler, Steve

    2005-01-01

    The Experiment to Characterize Aircraft Volatile Aerosols and Trace Species Emissions (EXCAVATE) took place at NASA Langley Research Center during January 2002. This ground based study was conducted to examine the role of fuel sulfur content on particulate emissions. Size distributions as a function of engine operating conditions were measured in the exhaust plume of a B-757 at four downstream axial locations (1 m, 10 m, 25 m and 35 m). The engine was run on JP-5 with three different sulfur concentrations, 810 ppm, 1050 ppm, 1820 ppm; and was operated over a range of power settings from idle to near-full power. Zalabsky differential-mobility analyzers DMAS), Met One condensation-nuclei counters (CNCs), and a TSI 3022 condensation-particle counter (CPC) were used to measure the size distributions. The total number-count (particle concentration), number-based Emissions Index (EInumber) and mass-based Emissions Index (E1-J increased with fuel sulfur-content and engine pressure ratio (EPR). Count Mean Diameter (Ch4D) also increased with EPR yet remained fairly constant with fuel sulfur-content for a fixed location in the exhaust plume. Also the mode and CMD both increased with distance in the plume.

  2. Application of polygon based laser micrometer for magnet size measurement studies

    Science.gov (United States)

    Khullar, Roma; Sharma, Geetanjali; Prakash, Bramh; Mishra, G.

    2014-09-01

    In this paper, we describe development of a polygon mirror based laser micrometer for magnet size measurement for undulator fabrication. In the laser micrometer, a laser light source is focused on to the facets of a rotating polygon mirror at an angle of 350 that reflects the laser beam. The parallel light emerging from the polygon mirror surface falls on the object through an F-theta lens. The F-theta lens is used for collimating the output of a scanning mirror system and to provide a flat field at the image plane of the scan. The object obstructs the light. A collimating lens at the other side of the object focuses the light onto a detector. The shadow caused by the obstruction results in an output voltage for a period of time that is proportional to the size of the object. We have used the laser micrometer for 12.5mm and 6.25mm magnets measurement. This is an efficient noncontact method of magnet sorting for use in undulator fabrication, synchrotron radiation and FEL application.

  3. Angular Size Measurements of 18 Mira Variable Stars at 2.2 microns

    Science.gov (United States)

    van Belle, G. T.; Dyck, H. M.; Benson, J. A.; Lacasse, M. G.

    1996-11-01

    We present angular size measurements of 18 oxygen-rich Mira variable stars. These data are part of a long term observational program using the Infrared Optical Telescope Array (IOTA) to characterize the observable behavior of these stars. Complementing the infrared angular size measurements, values for variable star phase, spectral type, bolometric flux, and distance were established for stars in the sample; flux and distance led to values for effective temperature (TEFF), and linear radius, respectively. We are able to define an effective temperature versus spectral type scale for Mira variables that we compare to the temperature scales for K and M giants and supergiants. TEFF'S and linear radii for these stars are shown to lie between approximately 2100 and 3200 K, and 200 and 600 Rsun, respectively. Relationships among the Mira variable parameters are explored for significant trends. Notably, the phase dependence of TEFF is shown to follow simple expectations, and examination of the radius-T relationship yields a plausible description of the V and K band light curves of these stars. A simple examination of the oscillation mode of the stars in the sample does not strongly suggest either fundamental or first-overtone oscillation as the primary mode of oscillation. This conclusion differs from that recently presented by Haniff et al. (1995), who argue that Mira variables are all first-overtone pulsators. We discuss some possible reasons for the different conclusions between the two studies.

  4. Method development and validation for measuring the particle size distribution of pentaerythritol tetranitrate (PETN) powders.

    Energy Technology Data Exchange (ETDEWEB)

    Young, Sharissa Gay

    2005-09-01

    Currently, the critical particle properties of pentaerythritol tetranitrate (PETN) that influence deflagration-to-detonation time in exploding bridge wire detonators (EBW) are not known in sufficient detail to allow development of a predictive failure model. The specific surface area (SSA) of many PETN powders has been measured using both permeametry and gas absorption methods and has been found to have a critical effect on EBW detonator performance. The permeametry measure of SSA is a function of particle shape, packed bed pore geometry, and particle size distribution (PSD). Yet there is a general lack of agreement in PSD measurements between laboratories, raising concerns regarding collaboration and complicating efforts to understand changes in EBW performance related to powder properties. Benchmarking of data between laboratories that routinely perform detailed PSD characterization of powder samples and the determination of the most appropriate method to measure each PETN powder are necessary to discern correlations between performance and powder properties and to collaborate with partnering laboratories. To this end, a comparison was made of the PSD measured by three laboratories using their own standard procedures for light scattering instruments. Three PETN powder samples with different surface areas and particle morphologies were characterized. Differences in bulk PSD data generated by each laboratory were found to result from variations in sonication of the samples during preparation. The effect of this sonication was found to depend on particle morphology of the PETN samples, being deleterious to some PETN samples and advantageous for others in moderation. Discrepancies in the submicron-sized particle characterization data were related to an instrument-specific artifact particular to one laboratory. The type of carrier fluid used by each laboratory to suspend the PETN particles for the light scattering measurement had no consistent effect on the resulting

  5. Measurements of Nucleation-Mode Particle Size Distributions in Aircraft Plumes during SULFUR 6

    Science.gov (United States)

    Brock, Charles A.; Bradford, Deborah G.

    1999-01-01

    This report summarizes the participation of the University of Denver in an airborne measurement program, SULFUR 6, which was undertaken in late September and early October of 1998 by the Deutsches Zentrum fur Luft und Raumfahrt (DLR). Scientific findings from two papers that have been published or accepted and from one manuscript that is in preparation are presented. The SULFUR 6 experiment was designed to investigate the emissions from subsonic aircraft to constrain calculations of possible atmospheric chemical and climatic effects. The University of Denver effort contributed toward the following SULFUR 6 goals: (1) To investigate the relationship between fuel sulfur content (FSC--mass of sulfur per mass of fuel) and particle number and mass emission index (El--quantity emitted per kg of fuel burned); (2) To provide upper and lower limits for the mass conversion efficiency (nu) of fuel sulfur to gaseous and particulate sulfuric acid; (3) To constrain models of volatile particle nucleation and growth by measuring the particle size distribution between 3 and 100 nm at aircraft plume ages ranging from 10(exp -1) to 10(exp 3) s; (4) To determine microphysical and optical properties and bulk chemical composition of soot particles in aircraft exhaust; and (5) To investigate the differences in particle properties between aircraft plumes in contrail and non-contrail situations. The experiment focused on emissions from the ATTAS research aircraft (a well characterized, but older technology turbojet) and from an in-service Boeing 737-300 aircraft provided by Lufthansa, with modem, high-bypass turbofan engines. Measurements were made from the DLR Dassault Falcon 900 aircraft, a modified business jet. The Atmospheric Effects of Aviation Program (AEAP) provided funding to operate an instrument, the nucleation-mode aerosol size spectrometer (N-MASS), during the SULFUR 6 campaign and to analyze the data. The N-MASS was developed at the University of Denver with the support of

  6. Particles emitted from indoor combustion sources: size distribution measurement and chemical analysis.

    Science.gov (United States)

    Roy, A A; Baxla, S P; Gupta, Tarun; Bandyopadhyaya, R; Tripathi, S N

    2009-08-01

    This study is primarily focused toward measuring the particle size distribution and chemical analysis of particulate matter that originates from combustion sources typically found in Indian urban homes. Four such sources were selected: cigarette, incense stick, mosquito coil, and dhoop, the latter being actually a thick form of incense stick. Altogether, seven of the most popular brands available in the Indian market were tested. Particle size distribution in the smoke was measured using a scanning mobility particle sizer, using both long and nano forms of differential mobility analyzer (DMA), with readings averaged from four to six runs. The measurable particle size range of the nano DMA was 4.6 nm to 157.8 nm, whereas that of the long DMA was 15.7 nm to 637.8 nm. Therefore, readings obtained from the long and the nano DMA were compared for different brands as well as for different sources. An overlap was seen in the readings in the common range of measurement. The lowest value of peak concentration was seen for one brand of incense stick (0.9 x 10(6) cm(-3)), whereas the highest (7.1 x 10(6) cm(-3)) was seen for the dhoop. Generally, these sources showed a peak between 140 and 170 nm; however, 2 incense stick brands showed peaks at 79 nm and 89 nm. The dhoop showed results much different from the rest of the sources, with a mode at around 240 nm. Chemical analysis in terms of three heavy metals (cadmium, zinc, and lead) was performed using graphite tube atomizer and flame-atomic absorption spectrophotometer. Calculations were made to assess the expected cancer and noncancer risks, using published toxicity potentials for these three heavy metals. Our calculations revealed that all the sources showed lead concentrations much below the American Conference of Governmental Industrial Hygienists (ACGIH) threshold limit value (TLV) level. One of the two mosquito coil brands (M(2)) showed cadmium concentrations two times higher than the California Environmental

  7. The effect of rebreathing and hyperventilation on retinal and choroidal vessels measured by spectral domain optical coherence tomography.

    Science.gov (United States)

    Ozcimen, Muammer; Sakarya, Yasar; Goktas, Sertan; Sakarya, Rabia; Alpfidan, Ismail; Yener, Halil I; Demir, Lutfi S

    2015-01-01

    The purpose of this study was to examine the vasoreactivity in retina and choroid of the healthy eyes in response to experimentally altered partial arterial pressure of carbon dioxide (PaCO(2)) using a non-invasive technique, spectral domain optical coherence tomography (SD-OCT). The study included non-smoking participants between 18 and 35 years of age, having visual acuity of 20/20 and with no systemic and ocular diseases. At baseline, the participants breathed room air (normocapnia). Hypocapnia was created with the help of hyperventilation; for this, the participants were instructed to draw deep and quick breaths, resulting one breathing cycle per 2 s. To create hypercapnia subjects rebreathed from a 5 l bag at least 3 min. Choroidal thickness and retinal artery diameter were measured at baseline, and hyperventilation and rebreathing conditions by SD-OCT. Twenty eyes of 20 healthy subjects were included in this study. Their mean age was 24.90 ± 5.32 years. Hyperventilation caused a significant reduction in choroidal thickness, compared with baseline, at all points; whereas rebreathing caused no significant change at all points. The mean diameters of the arteries were 151.80 ± 7.88 μm, with a significant decline to 148.90 ± 7.25 μm at hyperventilation condition and a significant increase to 153.50 ± 7.88 μm at rebreathing condition (p = 0.018, p = 0.043, respectively). This study demonstrated that, SD-OCT was a useful tool in measuring the ocular vascular response under hypercapnia and hypocapnia conditions. These findings may be helpful for further understanding the physiological nature of ocular blood flow and this preliminary study provides a basis for future studies.

  8. Aerodynamic particle size measurement by laser--Doppler velocimetry. Publication number 343

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, J.C.

    1977-12-01

    A method of measuring the aerodynamic diameter of aerosol particles was investigated. The method consists of accelerating particles in a coverging nozzle and measuring their velocities near the exit of th nozzle with a laser--Doppler velocimeter. The experimental studies utilized a test nozzle with a converging angle of approximately 15/sup 0/ and an exit diameter of about .1 cm. The pressure drop across the nozzle was varied from 2.54 to 276 cm of H/sub 2/O, and particle velocity was observed to vary from approximately 0.5 to 1.0 times the gas velocity at the exit of the nozzle. A theoretical analysis utilized boundary layer theory to predict the velocity of the gas in the nozzle, and then the equations of particle motion were integrated to give the theoretical particle velocities. These values agreed with the experimental values to within a few percent. The effects of nozzle geometry, flow rate, particle density, and particle size were studied using the results of calculations made with dimensionless equations. The velocity of a particle in a given nozzle and flow depends upon the aerodynamic diameter of the particle and the particle density. The geometry and flow can be chosen to minimize the effect of particle density. Assuming that the density of particles in the atmosphere ranges from 1 g/cm/sup 3/ to 3 g/cm/sup 3/, the aerodynamic diameter of particles can be measured with an uncertainty of +- 10% in the size range from .5 ..mu..m to 10 ..mu..m.

  9. Particle Imaging Velocimetry Technique Development for Laboratory Measurement of Fracture Flow Inside a Pressure Vessel Using Neutron Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Polsky, Yarom [ORNL; Bingham, Philip R [ORNL; Bilheux, Hassina Z [ORNL; Carmichael, Justin R [ORNL

    2015-01-01

    This paper will describe recent progress made in developing neutron imaging based particle imaging velocimetry techniques for visualizing and quantifying flow structure through a high pressure flow cell with high temperature capability (up to 350 degrees C). This experimental capability has great potential for improving the understanding of flow through fractured systems in applications such as enhanced geothermal systems (EGS). For example, flow structure measurement can be used to develop and validate single phase flow models used for simulation, experimentally identify critical transition regions and their dependence on fracture features such as surface roughness, and study multiphase fluid behavior within fractured systems. The developed method involves the controlled injection of a high contrast fluid into a water flow stream to produce droplets that can be tracked using neutron radiography. A description of the experimental setup will be provided along with an overview of the algorithms used to automatically track droplets and relate them to the velocity gradient in the flow stream. Experimental results will be reported along with volume of fluids based simulation techniques used to model observed flow.

  10. The LoG characteristic scale: a consistent measurement of lung nodule size in CT imaging.

    Science.gov (United States)

    Diciotti, Stefano; Lombardo, Simone; Coppini, Giuseppe; Grassi, Luca; Falchini, Massimo; Mascalchi, Mario

    2010-02-01

    Nodule growth as observed in computed tomography (CT) scans acquired at different times is the primary feature to malignancy of indeterminate small lung nodules. In this paper, we propose the estimation of nodule size through a scale-space representation which needs no segmentation and has high intra- and inter-operator reproducibility. Lung nodules usually appear in CT images as blob-like patterns and can be analyzed in the scale-space by Laplacian of Gaussian ( LoG ) kernels. For each nodular pattern the LoG scale-space signature was computed and the related characteristic scale adopted as measurement of nodule size. Both in vitro and in vivo validation of LoG characteristic scale were carried out. In vitro validation was done by 40 nondeformable phantoms and 10 deformable phantoms. A close relationship between the characteristic scale and the equivalent diameter, i.e., the diameter of the sphere having the same volume of nodules, (Pearson correlation coefficient was 0.99) and, for nodules undergoing little deformations (obtained at constant volume), small variability of the characteristic scale was observed. The in vivo validation was performed on low and standard-dose CT scans collected from the ITALUNG screening trial (86 nodules) and from the LIDC public data set (89 solid nodules and 40 part-solid nodules or ground-glass opacities). The Pearson correlation coefficient between characteristic scale and equivalent diameter was 0.83-0.93 for ITALUNG and 0.68-0.83 for LIDC data set. Intra- and inter-operator reproducibility of characteristic scale was excellent: on a set of 40 lung nodules of ITALUNG data, two radiologists produced identical results in repeated measurements. The scan-rescan variability of the characteristic scale was also investigated on 86 two-year-stable solid lung nodules (each one observed, on average, in four CT scans) identified in the ITALUNG screening trial: a coefficient of repeatability of about 0.9 mm was observed. Experimental

  11. BIOASSAY VESSEL FAILURE ANALYSIS

    Energy Technology Data Exchange (ETDEWEB)

    Vormelker, P

    2008-09-22

    Two high-pressure bioassay vessels failed at the Savannah River Site during a microwave heating process for biosample testing. Improper installation of the thermal shield in the first failure caused the vessel to burst during microwave heating. The second vessel failure is attributed to overpressurization during a test run. Vessel failure appeared to initiate in the mold parting line, the thinnest cross-section of the octagonal vessel. No material flaws were found in the vessel that would impair its structural performance. Content weight should be minimized to reduce operating temperature and pressure. Outer vessel life is dependent on actual temperature exposure. Since thermal aging of the vessels can be detrimental to their performance, it was recommended that the vessels be used for a limited number of cycles to be determined by additional testing.

  12. Application of optical disdrometer to characterize simulated rainfall and measure drop size distribution

    Science.gov (United States)

    Meshesha, Derege; Tsunekawa, Atsushi; Ayehu, Nigussie

    2017-04-01

    Soil erosion by water is becoming a major threat in tropical and semiarid regions, which is causing a serious of land degradation and socio-economic problems. Knowledge of rainfall characteristics, drop size distributions and relationship between rainfall elements is essential for development of erosion-mitigation strategies. Thus, this research was carried out to further investigate the nature of raindrop size distribution, median volume drop diameter (D50) and radar reflectivity (dBz) of the different intensities using simulated rainfall and optical distrometer. Besides, operational principle and capabilities of the optical distrometer (Laser Precipitation Monitor (LPM)) to characterize rainfall of different intensities and conduct measurement was evaluated. The rain was simulated from 12 meter height and the sensor constantly and automatically recorded the diameter and terminal velocity of each raindrop and gave the output in every 1 minute interval. The median volume drop diameter (D50) of the simulated rain was found to be higher than the natural rain for almost all rainfall intensities, which might be attributed to variation in rainfall types and prevalence of turbulence in natural rain that makes larger drop sizes unstable. The result of radar reflectivity (Z) and intensity (R) relationship revealed that, similar to natural rainfall, power law function is the most suitable equation for all rainfall rates (Z=aRb). For the whole rainfall intensity datasets (1.5 to 202 mm h-1) a varies from 0.94 to 2.46 while b ranges from 162 to 706. The optical device used in the study was found to be efficient and suitable to the purpose of rainfall characterization at 1 min resolution.

  13. Measuring the Accretion Disk Size in Mrk 509 using Continuum Reverberation Mapping

    Science.gov (United States)

    Barth, Aaron

    2017-08-01

    Continuum reverberation mapping from X-rays through optical wavelengths provides a unique probe of accretion disk structure in active galactic nuclei (AGN) on spatial scales of light-days. Recent Swift monitoring campaigns for NGC 5548 and NGC 4151 have provided dramatic evidence that accretion disk sizes are too large to be compatible with standard thin-disk models, requiring a major revision of our understanding of AGN accretion disks. We are currently carrying out an intensive 9-month Swift and ground-based monitoring campaign targeting Mrk 509, an AGN with luminosity an order of magnitude greater than other recent Swift monitoring targets, to map its accretion disk size. The UV and optical filter bands used for photometric monitoring include significant contamination by reprocessed emission from the broad-line region (BLR), including broad emission lines, Balmer continuum, and Fe II emission. In order to quantify the effect of this BLR emission on the accretion disk time delays, we propose to obtain a STIS UV/optical spectrum of the nucleus of Mrk 509 while our Swift campaign is in progress. We will use the STIS spectrum to determine the contribution of broad-line, Balmer continuum, and Fe II emission to each of the UV and optical filters. By correcting for this BLR contamination we will derive wavelength-dependent time delays for the AGN continuum that will provide an accurate measure of the accretion disk size and structure. Our new STIS data will additionally provide new diagnostics of broad-line region and narrow-line region physical conditions and a direct comparison of black hole mass estimates from broad emission lines including H-beta, C IV, and Mg II.

  14. Measurements of bubble size spectra within leads in the Arctic summer pack ice

    Directory of Open Access Journals (Sweden)

    S. J. Norris

    2011-02-01

    Full Text Available The first measurements of bubble size spectra within the near-surface waters of open leads in the central Arctic pack ice were obtained during the Arctic Summer Cloud-Ocean Study (ASCOS in August 2008 at 87–87.6° N, 1–11° W. A significant number of small bubbles (30–100 μm diameter were present, with concentration decreasing rapidly with size from 100–560 μm; no bubbles larger than 560 μm were observed. The bubbles were present both during periods of low wind speed (U<6 m s−1 and when ice covered the surface of the lead. The low wind and short open-water fetch precludes production of bubbles by wave breaking suggesting that the bubbles are generated by processes below the surface. When the surface water was open to the atmosphere bubble concentrations increased with increasing heat loss to the atmosphere. The presence of substantial numbers of bubbles is significant because the bursting of bubbles at the surface provides a mechanism for the generation of aerosol and the ejection of biological material from the ocean into the atmosphere. Such a transfer has previously been proposed as a potential climate feedback linking marine biology and Arctic cloud properties.

  15. Measurements of bubble size spectra within leads in the Arctic summer pack ice

    Science.gov (United States)

    Norris, S. J.; Brooks, I. M.; de Leeuw, G.; Sirevaag, A.; Leck, C.; Brooks, B. J.; Birch, C. E.; Tjernstrom, M.

    2010-10-01

    The first measurements of bubble size spectra within the near-surface waters of open leads in the central Arctic pack ice were obtained during the Artic Summer Cloud-Ocean Study (ASCOS) in August 2008 at 87-87.6° N, 1-11° W. A significant number of small bubbles (30-100 μm diameter) were present, with concentration decreasing rapidly with size from 100-560 μm; no bubbles larger than 560 μm were observed. The bubbles were present both during periods of low wind speed (U ice covered the surface of the lead. The low wind and short open-water fetch precludes production of bubbles by wave breaking suggesting that the bubbles are generated by processes below the surface. When the surface water was open to the atmosphere bubble concentrations increased with increasing heat loss to the atmosphere. The presence of substantial numbers of bubbles is significant because the bursting of bubbles at the surface provides a mechanism for the generation of aerosol and the ejection of biological material from the ocean into the atmosphere. Such a transfer has previously been proposed as a potential climate feedback linking marine biology and Arctic cloud properties.

  16. A simultaneous charge and size measurement method for individual airborne particles using digital holographic particle imaging

    Science.gov (United States)

    Hammond, Adam; Dou, Zhongwang; Liang, Zach; Meng, Hui

    2016-11-01

    Recently, significant inquiry to understand the effects of particle charge on particle laden flow have been made, particularly in the study of Lagrangian particle-pair statistics. Quantification of individual particle charge allows relation of inter-particle electric forces and turbulence-induced forces. Here we offer a simultaneous, individual particle charge and size measurement technique utilizing in-line digital holographic Particle Tracking Velocimetry (hPTV). The method measures particle electric mobility through its velocity response within a uniform electric field using a sequence of holograms, next the particle diameter is measured with the same holograms using a matched-filter developed by Lu et al. (2012) as an input for calculation of charge. Consequently, a benefit of this method is that particle charge is calculated on the individual level, versus a mean charge calculated from a group of particles, offering improved estimations of charge distributions for studies of particle laden flow. This work was supported by NSF CBET-0967407 and CBET-0967349.

  17. Reproducibility of Ultrasound and Magnetic Resonance Imaging Measurements of Tendon Size

    Energy Technology Data Exchange (ETDEWEB)

    Brushoej, C.; Henriksen, B.M.; Albrecht-Beste, E.; Hoelmich, P.; Larsen, K.; Bachmann Nielsen, M. [Rigshospitalet, Copenhagen (Denmark). Dept. of Radiology

    2006-11-15

    Purpose: To investigate the intra- and inter-tester reproducibility of measurements of the Achilles tendon, tibialis anterior tendon, and the tibialis posterior tendon in football players using ultrasound (US) and magnetic resonance imaging (MRI). Material and Methods: Eleven asymptomatic football players were examined. Using a standardized US scanning protocol, the tendons were examined by two observers with US for thickness, width, and cross-sectional area. One observer conducted the procedure twice. The subjects also underwent an MRI examination, and the assessment of tendon size was conducted twice by two observers. Results: The best reproducibility judged by coefficient of variation (CV) and 95% confidence interval was determined for the Achilles tendon on both US and MRI. The variability of US on measurements on the tibialis anterior and tibialis posterior tendons was less than that when using MRI. In 12 out of 18 measurements, there were systematic differences between observers as judged by one-sided F-test. Conclusion: The reproducibility of the three tendons was limited. Precaution should be taken when looking for minor quantitative changes, i.e., training-induced hypertrophy, and when doing so, the Achilles tendon should be used.

  18. Decoupling of size and shape fluctuations in heteropolymeric sequences reconciles discrepancies in SAXS vs. FRET measurements.

    Science.gov (United States)

    Fuertes, Gustavo; Banterle, Niccolò; Ruff, Kiersten M; Chowdhury, Aritra; Mercadante, Davide; Koehler, Christine; Kachala, Michael; Estrada Girona, Gemma; Milles, Sigrid; Mishra, Ankur; Onck, Patrick R; Gräter, Frauke; Esteban-Martín, Santiago; Pappu, Rohit V; Svergun, Dmitri I; Lemke, Edward A

    2017-08-01

    Unfolded states of proteins and native states of intrinsically disordered proteins (IDPs) populate heterogeneous conformational ensembles in solution. The average sizes of these heterogeneous systems, quantified by the radius of gyration (RG ), can be measured by small-angle X-ray scattering (SAXS). Another parameter, the mean dye-to-dye distance (RE ) for proteins with fluorescently labeled termini, can be estimated using single-molecule Förster resonance energy transfer (smFRET). A number of studies have reported inconsistencies in inferences drawn from the two sets of measurements for the dimensions of unfolded proteins and IDPs in the absence of chemical denaturants. These differences are typically attributed to the influence of fluorescent labels used in smFRET and to the impact of high concentrations and averaging features of SAXS. By measuring the dimensions of a collection of labeled and unlabeled polypeptides using smFRET and SAXS, we directly assessed the contributions of dyes to the experimental values RG and RE For chemically denatured proteins we obtain mutual consistency in our inferences based on RG and RE , whereas for IDPs under native conditions, we find substantial deviations. Using computations, we show that discrepant inferences are neither due to methodological shortcomings of specific measurements nor due to artifacts of dyes. Instead, our analysis suggests that chemical heterogeneity in heteropolymeric systems leads to a decoupling between RE and RG that is amplified in the absence of denaturants. Therefore, joint assessments of RG and RE combined with measurements of polymer shapes should provide a consistent and complete picture of the underlying ensembles.

  19. UV/X-Ray Diffraction Radiation for non-intercepting Micron-Scale Beam Size Measurement

    CERN Document Server

    -; Lefevre, T; Karataev, P; Billing, M

    2012-01-01

    Diffraction radiation (DR) is produced when a relativistic charged particle moves in the vicinity of a medium. The electric field of the charged particle polarizes the target atoms which then oscillate, emitting radiation with a very broad spectrum. The spatial-spectral properties of DR are sensitive to a range of electron beam parameters. Furthermore, the energy loss due to DR is so small that the electron beam parameters are unchanged. Therefore DR can be used to develop non-invasive diagnostic tools. The aim of this project is to measure the transverse (vertical) beam size using incoherent DR. To achieve the micron-scale resolution required by CLIC, DR in UV and X-ray spectral-range must be investigated. During the next few years, experimental validation of such a scheme will be conducted on the CesrTA at Cornell University, USA. Here we present the current status of the experiment preparation.

  20. Numerical simulations and measurements of a droplet size distribution in a turbulent vortex street

    Directory of Open Access Journals (Sweden)

    Ellen Schmeyer

    2014-09-01

    Full Text Available A turbulent vortex street in an air flow interacting with a disperse droplet population is investigated in a wind tunnel. Non-intrusive measurement techniques are used to obtain data for the air velocity and the droplet velocity. The process is modeled with a population balance system consisting of the incompressible Navier-Stokes equations and a population balance equation for the droplet size distribution. Numerical simulations are performed that rely on a variational multiscale method for turbulent flows, a direct discretization of the differential operator of the population balance equation, and a modern technique for the evaluation of the coalescence integrals. After having calibrated two unknown model parameters, a very good agreement of the experimental and numerical results can be observed.

  1. Planosol soil sample size for computerized tomography measurement of physical parameters

    Directory of Open Access Journals (Sweden)

    Pedrotti Alceu

    2003-01-01

    Full Text Available Computerized tomography (CT is an important tool in Soil Science for noninvasive measurement of density and water content of soil samples. This work aims to describe the aspects of sample size adequacy for Planosol (Albaqualf and to evaluate procedures for statistical analysis, using a CT scanner with a 241Am source. Density errors attributed to the equipment are 0.051 and 0.046 Mg m-3 for horizons A and B, respectively. The theoretical value for sample thickness for the Planosol, using this equipment, is 4.0 cm for the horizons A and B. The ideal thickness of samples is approximately 6.0 cm, being smaller for samples of the horizon B in relation to A. Alternatives for the improvement of the efficiency analysis and the reliability of the results obtained by CT are also discussed, and indicate good precision and adaptability of the application of this technology in Planosol (Albaqualf studies.

  2. Optomechanical measurement of a millimeter-sized mechanical oscillator approaching the quantum ground state

    Science.gov (United States)

    Santos, J. T.; Li, J.; Ilves, J.; Ockeloen-Korppi, C. F.; Sillanpää, M.

    2017-10-01

    Cavity optomechanics is a tool to study the interaction between light and micromechanical motion. Here we observe optomechanical physics in a truly macroscopic oscillator close to the quantum ground state. As the mechanical system, we use a mm-sized piezoelectric quartz disk oscillator. Its motion is coupled to a charge qubit which translates the piezo-induced charge into an effective radiation-pressure interaction between the disk and a microwave cavity. We measure the thermal motion of the lowest mechanical shear mode at 7 MHz down to 30 mK, corresponding to roughly 102 quanta in a 20 mg oscillator. We estimate that with realistic parameters, it is possible to utilize the back-action cooling by the qubit in order to control macroscopic motion by a single Cooper pair. The work opens up opportunities for macroscopic quantum experiments.

  3. A simple non-invasive method for measuring gross brain size in small live fish with semi-transparent heads

    Directory of Open Access Journals (Sweden)

    Joacim Näslund

    2014-09-01

    Full Text Available This paper describes a non-invasive method for estimating gross brain size in small fish with semi-transparent heads, using system camera equipment. Macro-photographs were taken from above on backlit free-swimming fish undergoing light anaesthesia. From the photographs, the width of the optic tectum was measured. This measure (TeO-measure correlates well with the width of the optic tectum as measured from out-dissected brains in both brown trout fry and zebrafish (Pearson r > 0.90. The TeO-measure also correlates well with overall brain wet weight in brown trout fry (r = 0.90, but less well for zebrafish (r = 0.79. A non-invasive measure makes it possible to quickly assess brain size from a large number of individuals, as well as repeatedly measuring brain size of live individuals allowing calculation of brain growth.

  4. An angiogenesis platform using a cubic artificial eggshell with patterned blood vessels on chicken chorioallantoic membrane.

    Directory of Open Access Journals (Sweden)

    Wenjing Huang

    Full Text Available The chorioallantoic membrane (CAM containing tiny blood vessels is an alternative to large animals for studies involving angiogenesis and tissue engineering. However, there is no technique to design the direction of growing blood vessels on the CAM at the microscale level for tissue engineering experiments. Here, a methodology is provided to direct blood vessel formation on the surface of a three-dimensional egg yolk using a cubic artificial eggshell with six functionalized membranes. A structure on the lateral side of the eggshell containing a straight channel and an interlinked chamber was designed, and the direction and formation area of blood vessels with blood flow was artfully defined by channels with widths of 70-2000 μm, without sharply reducing embryo viability. The relationship between the size of interlinked chamber and the induction of blood vessels was investigated to establish a theory of design. Role of negative and positive pressure in the induction of CAM with blood vessels was investigated, and air pressure change in the culture chamber was measured to demonstrate the mechanism for blood vessel induction. Histological evaluation showed that components of CAM including chorionic membrane and blood vessels were induced into the channels. Based on our design theory, blood vessels were induced into arrayed channels, and channel-specific injection and screening were realized, which demonstrated proposed applications. The platform with position- and space-controlled blood vessels is therefore a powerful tool for biomedical research, which may afford exciting applications in studies involved in local stimulation of blood vessel networks and those necessary to establish a living system with blood flow from a beating heart.

  5. Comprehensive Analysis of Chicken Vessels as Microvascular Anastomosis Training Model

    Directory of Open Access Journals (Sweden)

    Bo Young Kang

    2017-01-01

    Full Text Available BackgroundNonliving chickens are commonly used as a microvascular anastomosis training model. However, previous studies have investigated only a few types of vessel, and no study has compared the characteristics of the various vessels. The present study evaluated the anatomic characteristics of various chicken vessels as a training model.MethodsEight vessels—the brachial artery, basilic vein, radial artery, ulnar artery, ischiatic artery and vein, cranial tibial artery, and common dorsal metatarsal artery—were evaluated in 26 fresh chickens and 30 chicken feet for external diameter (ED and thicknesses of the tunica adventitia and media. The dissection time from skin incision to application of vessel clamps was also measured.ResultsThe EDs of the vessels varied. The ischiatic vein had the largest ED of 2.69±0.33 mm, followed by the basilic vein (1.88±0.36 mm, ischiatic artery (1.68±0.24 mm, common dorsal metatarsal artery (1.23±0.23 mm, cranial tibial artery (1.18±0.19 mm, brachial artery (1.08±0.15 mm, ulnar artery (0.82±0.13 mm, and radial artery (0.56±0.12 mm, and the order of size was consistent across all subjects. Thicknesses of the tunica adventitia and media were also diverse, ranging from 74.09±19.91 µm to 158.66±40.25 µm (adventitia and from 31.2±7.13 µm to 154.15±46.48 µm (media, respectively. Mean dissection time was <3 minutes for all vessels.ConclusionsOur results suggest that nonliving chickens can provide various vessels with different anatomic characteristics, which can allow trainees the choice of an appropriate microvascular anastomosis training model depending on their purpose and skillfulness.

  6. Vessel involvement in giant cell arteritis : an imaging approach

    NARCIS (Netherlands)

    Holm, Pieter W.; Sandovici, Maria; Slart, Riemer H. J. A.; Glaudemans, Andor W. J. M.; Rutgers, Abraham; Brouwer, Elisabeth

    Vasculitis is classified based on the size of the involved vessels. The two major forms are small vessel vasculitis and large vessel vasculitis (LVV). Main forms of LVV are Takayasu arteritis, giant cell arteritis (GCA), isolated aortitis and chronic periaortitis. This manuscript will focus on GCA,

  7. Characteristics of dust particles abraded from pesticide treated seeds: 1. Size distribution using different measuring techniques.

    Science.gov (United States)

    Foqué, Dieter; Zwertvaegher, Ingrid Ka; Devarrewaere, Wouter; Verboven, Pieter; Nuyttens, David

    2017-07-01

    Particle size is one of the most important properties affecting the driftability and behaviour of dust particles abraded from pesticide dressed seeds during sowing. Three particle sizing techniques were used determine the particle size distribution of dust abraded from seeds from six different species. Important differences in dust particle size distribution between species were observed with the finest dust for rapeseed and the coarsest dust for barley. Wet laser diffraction and sonic sieving particle size results correlated well while micro-CT is able to deliver three-dimensional information and additional physical particle properties (shape, porosity). All particle sizing techniques have their (dis)advantages and none of them is able to perfectly describe the real size distribution of non-spherical particles. The particle size information gathered can be used in dust drift prediction models, risk assessment tools and will help to better understand the dust drift phenomenon. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  8. Measurement of the thickness of the sprayed nickel coatings on large-sized cast iron products

    Directory of Open Access Journals (Sweden)

    В. А. Сясько

    2016-11-01

    Full Text Available Modern industries increasingly use automatic spraying of heat-resistant Nickel  coating with a thickness  of      T = 1-3 mm for large-size parts made of cast iron with nodular graphite. The process of coating application is characterized by time-dependent behavior of its relative magnetic permeability, μс , that is a function of relaxation time, which can be as long as 24 hours, and by μс deviation from point to point on the surface. Aspects of eddy-current phase method for measuring the T value are considered. The structure of four- winding eddy current transformer transducers is described and results of calculation and optimization of their parameters are presented. The influence of controlled and interfering parameters is considered. Based  on the above results, a two-channel combined transducer is developed  providing measurement  error  of ΔТ ≤ ±(0.03T + 0.02 mm  in the shop environment in the process of coating application and in the final product check. Results of tests on reference specimens and of application in production processes are presented.

  9. Guam Abandoned Vessel Inventory

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA Abandoned Vessel Project Data for Guam. Abandoned vessels pose a significant threat to the NOAA Trust resources through physical destruction of coral habitats...

  10. Florida Abandoned Vessel Inventory

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA Abandoned Vessel Project Data for Florida. Abandoned vessels pose a significant threat to the NOAA Trust resources through physical destruction of coral...

  11. Vessel Arrival Info - Legacy

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Vessel Arrival Info is a spreadsheet that gets filled out during the initial stage of the debriefing process by the debriefer. It contains vessel name, trip...

  12. Assessment of the quality of drop size measurements using a non-dedicated present weather sensor

    NARCIS (Netherlands)

    Leijnse, H.; Uijlenhoet, R.

    2009-01-01

    Drop size data from a present weather sensor have been compared to drop size data collected using a nearly co-located dedicated disdrometer. In a rainfall event that lasted more than 9 hours, with rainfall intensities up to 25 mm h-1 drop size distributions (DSDs) estimated by the two different

  13. Particle Size Distributions Measured in B757 Engine Plume During EXCAVATE

    Science.gov (United States)

    Sanders, Terry; Penko, Paul; Culler, Steve; Rivera, Monica

    2005-01-01

    A ground-based test, the Experiment to Characterize Aircraft Volatile Aerosols and Trace Species Emissions (EXCAVATE), was conducted at NASA Langley Research Center, January 26 - 27, 2002, with a Boeing 757 aircraft. The aircraft was anchored on a tarmac and two probes were positioned downstream of the right-side engine, a Rolls Royce RB211-585. One probe was designed and fabricated by Arnold Engineering Development Center (AEDC) and had a 45.6 mm (1.794 in.) ID. A second probe, constructed of 6.4 mm (0.25 in.) stainless-steel tubing at NASA Langley Research Center, had a 6 mm (0.22 in.) ID. The engine was run on JP-5 with three different sulfur concentrations, 810 ppm, 1050 ppm, 1820 ppm; and was operated over a range of power settings from idle to near-full power. Particulate size-distributions and concentrations were measured at four downstream axial locations: 1 m and 10 m with the AEDC particulate probe, and 25 m and 35 m with the Langley probe. Fuel with various sulfur contents was tested to address the long-standing question of the role of sulfur in the formation of volatile species. Several experimental and modeling studies have shown a correlation between fuel sulfur-content and particulate-emissions. The object of EXCAVATE was to further study the effect of sulfur content on particulate number concentration and size-distribution as a function of location in the engine plume and engine operating conditions.

  14. State size as measured in terms of public spending and world health, 1990-2000.

    Science.gov (United States)

    Franco, Alvaro; Gil, Diana; Alvarez-Dardet, Carlos

    2005-01-01

    To determine the relationship between state size (measured in terms of public spending) and public health indicators in a sample of countries representing all regions of the world and from 1990-2000. An ecological study was performed using data on Central Government Spending (CGS) and per capita Gross National Product (GNP) obtained from the International Monetary Fund, and on life expectancy, maternal, and infant mortality, provided by the World Health Organization. A multiple linear regression model was fitted to estimate the effect of CGS on health, which also took into consideration per capita GNP and geographical region. CGS varied little over the study period, with convergence around an average of 28%, but within a relatively wide range (7.80-53.0%); the countries with the strongest economies (according to per capita GNP) had the highest levels of CGS. The influence of this factor was particularly relevant for the infant mortality rate (r = 0.40; beta = -1.327; EE = 0.237; t = -5.590; p < 0.001). Per capita GNP and geographic location were also associated with variations in health; health indicators tended to be worse for poorer countries in Africa and Asia. In the adjusted model, CGS was statistically significant with regard to infant and maternal mortality rates. The study suggests that state size (in terms of public spending) has an important influence upon health and particularly upon mortality. Although it is important to bear in mind the limitations of this study and the reduced time window used, these results should be taken into consideration in the current political and epidemiological debate.

  15. Respirable size-selective sampler for end-of-shift quartz measurement: Development and performance.

    Science.gov (United States)

    Lee, Taekhee; Lee, Larry; Cauda, Emanuele; Hummer, Jon; Harper, Martin

    2017-05-01

    Aims of this study were to develop a respirable size-selective sampler for direct-on-filter (DoF) quartz measurement at the end-of-shift (EoS) using a portable Fourier transform infrared (FTIR) spectrometer and to determine its size-selective sampling performance. A new miniaturized sampler has been designed to have an effective particle deposition diameter close to the portable FTIR beam diameter (6 mm). The new sampler (named the EoS cyclone) was constructed using a 3D printer. The sampling efficiency of the EoS cyclone was determined using polydisperse glass sphere particles and a time-of-flight direct reading instrument. Respirable dust mass concentration and quartz absorbance levels of samples collected with the EoS cyclone were compared to those collected with the 10-mm nylon cyclone. The EoS cyclone operated at a flow rate of 1.2 l min -1 showed minimum bias compared to the international standard respirable convention. The use of the EoS cyclone induced respirable dust mass concentration results similar but significantly larger (5%) than those obtained from samples collected with 10-mm nylon cyclones. The sensitivity of the DoF-FTIR analysis in estimating quartz was found increased more than 10 times when the samples were collected with the EoS cyclone. The average particle deposition diameter was 8.8 mm in 60 samples. The newly developed user friendly EoS cyclone may provide a better sampling strategy in quartz exposure assessment with faster feedback.

  16. Size Resolved Measurements of Springtime Aerosol Particles over the Northern South China Sea

    Science.gov (United States)

    Atwood, Samuel A.; Reid, Jeffrey S.; Kreidenweis, Sonia M.; Cliff, Stephen S.; Zhao, Yongjing; Lin, Neng-Huei; Tsay, Si-Chee; Chu, Yu-Chi; Westphal, Douglas L.

    2012-01-01

    Large sources of aerosol particles and their precursors are ubiquitous in East Asia. Such sources are known to impact the South China Sea (henceforth SCS), a sometimes heavily polluted region that has been suggested as particularly vulnerable to climate change. To help elucidate springtime aerosol transport into the SCS, an intensive study was performed on the remote Dongsha (aka Pratas) Islands Atoll in spring 2010. As part of this deployment, a Davis Rotating-drum Uniform size-cut Monitor (DRUM) cascade impactor was deployed to collect size-resolved aerosol samples at the surface that were analyzed by X-ray fluorescence for concentrations of selected elements. HYSPLIT backtrajectories indicated that the transport of aerosol observed at the surface at Dongsha was occurring primarily from regions generally to the north and east. This observation was consistent with the apparent persistence of pollution and dust aerosol, along with sea salt, in the ground-based dataset. In contrast to the sea-level observations, modeled aerosol transport suggested that the westerly flow aloft (w700 hPa) transported smoke-laden air toward the site from regions from the south and west. Measured aerosol optical depth at the site was highest during time periods of modeled heavy smoke loadings aloft. These periods did not coincide with elevated aerosol concentrations at the surface, although the model suggested sporadic mixing of this free-tropospheric aerosol to the surface over the SCS. A biomass burning signature was not clearly identified in the surface aerosol composition data, consistent with this aerosol type remaining primarily aloft and not mixing strongly to the surface during the study. Significant vertical wind shear in the region also supports the idea that different source regions lead to varying aerosol impacts in different vertical layers, and suggests the potential for considerable vertical inhomogeneity in the SCS aerosol environment.

  17. ALICE HMPID Radiator Vessel

    CERN Multimedia

    2003-01-01

    View of the radiator vessels of the ALICE/HMPID mounted on the support frame. Each HMPID module is equipped with 3 indipendent radiator vessels made out of neoceram and fused silica (quartz) windows glued together. The spacers inside the vessel are needed to stand the hydrostatic pressure. http://alice-hmpid.web.cern.ch/alice-hmpid

  18. Confounding compression: the effects of posture, sizing and garment type on measured interface pressure in sports compression clothing.

    Science.gov (United States)

    Brophy-Williams, Ned; Driller, Matthew William; Shing, Cecilia Mary; Fell, James William; Halson, Shona Leigh; Halson, Shona Louise

    2015-01-01

    The purpose of this investigation was to measure the interface pressure exerted by lower body sports compression garments, in order to assess the effect of garment type, size and posture in athletes. Twelve national-level boxers were fitted with sports compression garments (tights and leggings), each in three different sizes (undersized, recommended size and oversized). Interface pressure was assessed across six landmarks on the lower limb (ranging from medial malleolus to upper thigh) as athletes assumed sitting, standing and supine postures. Sports compression leggings exerted a significantly higher mean pressure than sports compression tights (P sports compression garments is significantly affected by garment type, size and posture assumed by the wearer.

  19. A liposome-based size calibration method for measuring microvesicles by flow cytometry

    DEFF Research Database (Denmark)

    Simonsen, Jens Bæk

    2016-01-01

    BACKGROUND: Over the last years the need for a gold standard to determine the sizes of extracellular vesicles including microvesicles by flow cytometry has been emphasized. METHODS: This work suggests to use artificial vesicles as calibrators to ascertain the size of microvesicles from the side...... to verify the correlation between the SSC from a liposome and the corresponding size. CONCLUSIONS: We show that artificial vesicles are more accurate size calibrators compared to the commonly used polystyrene calibrator beads illustrated by the SSC from 110 nm polystyrene beads corresponds to the scattering...... from ~400 nm sized vesicle-like particles. We also show that this method of size assessment based on SSC has a low resolution that is roughly estimated to be between 60 to 200 nm dependent on the vesicle size. This article is protected by copyright. All rights reserved....

  20. Analysis of point source size on measurement accuracy of lateral point-spread function of confocal Raman microscopy

    Science.gov (United States)

    Fu, Shihang; Zhang, Li; Hu, Yao; Ding, Xiang

    2018-01-01

    Confocal Raman Microscopy (CRM) has matured to become one of the most powerful instruments in analytical science because of its molecular sensitivity and high spatial resolution. Compared with conventional Raman Microscopy, CRM can perform three dimensions mapping of tiny samples and has the advantage of high spatial resolution thanking to the unique pinhole. With the wide application of the instrument, there is a growing requirement for the evaluation of the imaging performance of the system. Point-spread function (PSF) is an important approach to the evaluation of imaging capability of an optical instrument. Among a variety of measurement methods of PSF, the point source method has been widely used because it is easy to operate and the measurement results are approximate to the true PSF. In the point source method, the point source size has a significant impact on the final measurement accuracy. In this paper, the influence of the point source sizes on the measurement accuracy of PSF is analyzed and verified experimentally. A theoretical model of the lateral PSF for CRM is established and the effect of point source size on full-width at half maximum of lateral PSF is simulated. For long-term preservation and measurement convenience, PSF measurement phantom using polydimethylsiloxane resin, doped with different sizes of polystyrene microspheres is designed. The PSF of CRM with different sizes of microspheres are measured and the results are compared with the simulation results. The results provide a guide for measuring the PSF of the CRM.

  1. Advanced characterisation of aerosol size properties from measurements of spectral optical depth using the GRASP algorithm

    Science.gov (United States)

    Torres, Benjamin; Dubovik, Oleg; Fuertes, David; Schuster, Gregory; Cachorro, Victoria Eugenia; Lapyonok, Tatsiana; Goloub, Philippe; Blarel, Luc; Barreto, Africa; Mallet, Marc; Toledano, Carlos; Tanré, Didier

    2017-10-01

    This study evaluates the potential of using aerosol optical depth (τa) measurements to characterise the microphysical and optical properties of atmospheric aerosols. With this aim, we used the recently developed GRASP (Generalized Retrieval of Aerosol and Surface Properties) code for numerical testing of six different aerosol models with different aerosol loads. The direct numerical simulations (self-consistency tests) indicate that the GRASP-AOD retrieval provides modal aerosol optical depths (fine and coarse) to within 0.01 of the input values. The retrieval of the fine-mode radius, width and volume concentration are stable and precise if the real part of the refractive index is known. The coarse-mode properties are less accurate, but they are significantly improved when additional a priori information is available. The tests with random simulated errors show that the uncertainty in the bimodal log-normal size distribution parameters increases as the aerosol load decreases. Similarly, the reduction in the spectral range diminishes the stability of the retrieved parameters. In addition to these numerical studies, we used optical depth observations at eight AERONET locations to validate our results with the standard AERONET inversion products. We found that bimodal log-normal size distributions serve as useful input assumptions, especially when the measurements have inadequate spectral coverage and/or limited accuracy, such as moon photometry. Comparisons of the mode median radii between GRASP-AOD and AERONET indicate average differences of 0.013 µm for the fine mode and typical values of 0.2-0.3 µm for the coarse mode. The dominant mode (i.e. fine or coarse) indicates a 10 % difference in mode radii between the GRASP-AOD and AERONET inversions, and the average of the difference in volume concentration is around 17 % for both modes. The retrieved values of the fine-mode τa(500) using GRASP-AOD are generally between those values obtained by the standard AERONET

  2. Advanced characterisation of aerosol size properties from measurements of spectral optical depth using the GRASP algorithm

    Directory of Open Access Journals (Sweden)

    B. Torres

    2017-10-01

    Full Text Available This study evaluates the potential of using aerosol optical depth (τa measurements to characterise the microphysical and optical properties of atmospheric aerosols. With this aim, we used the recently developed GRASP (Generalized Retrieval of Aerosol and Surface Properties code for numerical testing of six different aerosol models with different aerosol loads. The direct numerical simulations (self-consistency tests indicate that the GRASP-AOD retrieval provides modal aerosol optical depths (fine and coarse to within 0.01 of the input values. The retrieval of the fine-mode radius, width and volume concentration are stable and precise if the real part of the refractive index is known. The coarse-mode properties are less accurate, but they are significantly improved when additional a priori information is available. The tests with random simulated errors show that the uncertainty in the bimodal log-normal size distribution parameters increases as the aerosol load decreases. Similarly, the reduction in the spectral range diminishes the stability of the retrieved parameters. In addition to these numerical studies, we used optical depth observations at eight AERONET locations to validate our results with the standard AERONET inversion products. We found that bimodal log-normal size distributions serve as useful input assumptions, especially when the measurements have inadequate spectral coverage and/or limited accuracy, such as moon photometry. Comparisons of the mode median radii between GRASP-AOD and AERONET indicate average differences of 0.013 µm for the fine mode and typical values of 0.2–0.3 µm for the coarse mode. The dominant mode (i.e. fine or coarse indicates a 10 % difference in mode radii between the GRASP-AOD and AERONET inversions, and the average of the difference in volume concentration is around 17 % for both modes. The retrieved values of the fine-mode τa(500 using GRASP-AOD are generally between those values obtained

  3. Beak measurements of octopus ( Octopus variabilis) in Jiaozhou Bay and their use in size and biomass estimation

    Science.gov (United States)

    Xue, Ying; Ren, Yiping; Meng, Wenrong; Li, Long; Mao, Xia; Han, Dongyan; Ma, Qiuyun

    2013-09-01

    Cephalopods play key roles in global marine ecosystems as both predators and preys. Regressive estimation of original size and weight of cephalopod from beak measurements is a powerful tool of interrogating the feeding ecology of predators at higher trophic levels. In this study, regressive relationships among beak measurements and body length and weight were determined for an octopus species ( Octopus variabilis), an important endemic cephalopod species in the northwest Pacific Ocean. A total of 193 individuals (63 males and 130 females) were collected at a monthly interval from Jiaozhou Bay, China. Regressive relationships among 6 beak measurements (upper hood length, UHL; upper crest length, UCL; lower hood length, LHL; lower crest length, LCL; and upper and lower beak weights) and mantle length (ML), total length (TL) and body weight (W) were determined. Results showed that the relationships between beak size and TL and beak size and ML were linearly regressive, while those between beak size and W fitted a power function model. LHL and UCL were the most useful measurements for estimating the size and biomass of O. variabilis. The relationships among beak measurements and body length (either ML or TL) were not significantly different between two sexes; while those among several beak measurements (UHL, LHL and LBW) and body weight (W) were sexually different. Since male individuals of this species have a slightly greater body weight distribution than female individuals, the body weight was not an appropriate measurement for estimating size and biomass, especially when the sex of individuals in the stomachs of predators was unknown. These relationships provided essential information for future use in size and biomass estimation of O. variabilis, as well as the estimation of predator/prey size ratios in the diet of top predators.

  4. Discrimination of Terrestrial Source Materials to the Northern North Atlantic Using Particle Size Specific Magnetic Measurements and Electron Microscopy.

    Science.gov (United States)

    Hatfield, R. G.; Stoner, J. S.; Tepley, F. J., III

    2015-12-01

    We investigate the magnetic properties of different terrestrial sediment fractions (sand, silt, and clay) from Iceland and Greenland as major sediment sources to the northern North Atlantic (NNA). Magnetic susceptibility (MS) and hysteresis data have previously shown to be strongly particle size dependent with silt (3-63μm) important for hosting the ferrimagnetic fraction and discriminating source. Here we expand upon these data with more fundamental observations including low temperature remanence, low and high temperature MS, and electron microscopy. All Iceland fractions lack a Verwey transition (Tv) and MS decreases gradually on heating between 100-500°C, consistent with (TM60) titanomagnetite. Frequency dependent MS (fd%; 1-998 Hz) of ~8% across all Iceland fractions implies significant SP grain populations within the average Day plot determined PSD grain size. Homogeneity in magnetic grain size across all Icelandic fractions implies a disconnect with physical grain size that is visualized in electron backscatter images as fine Fe-rich fragments are included within larger host grains. In contrast Greenlandic silt and sand possess a strong Tv and MS values that fall steeply between 560-580°C on heating, consistent with magnetite. Greenlandic ferrimagnetic fragments within the silt and sand size fractions exist as discrete particles and average magnetic grain size scales with physical grain size; the sand fraction is dominated by MD grains and silts are coarse PSD in size. While finer PSD clays are indistinguishable from all Iceland fractions on a Day plot SP contributions are lower and the Tv is more pronounced in Greenland clay. These new magnetic mineralogy, magnetic grain size, and electron microscopy measurements expand the differentiation of source and grain size of NNA source materials, and further highlight the necessity for grain-size specific magnetic measurements to isolate source from physical grain size variation in bulk marine sediment cores.

  5. Performance of high-resolution SEM/EDX systems equipped with transmission mode (TSEM) for imaging and measurement of size and size distribution of spherical nanoparticles.

    Science.gov (United States)

    Hodoroaba, Vasile-Dan; Motzkus, Charles; Macé, Tatiana; Vaslin-Reimann, Sophie

    2014-04-01

    The analytical performance of high-resolution scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDX) for accurate determination of the size, size distribution, qualitative elemental analysis of nanoparticles (NPs) was systematically investigated. It is demonstrated how powerful high-resolution SEM is by using both mono- and bi-modal distributions of SiO2 airborne NPs collected on appropriate substrates after their generation from colloidal suspension. The transmission mode of the SEM (TSEM) is systematically employed for NPs prepared on thin film substrates such as transmission electron microscopy grids. Measurements in the transmission mode were performed by using a "single-unit" TSEM transmission setup as manufactured and patented by Zeiss. This alternative to the "conventional" STEM detector consists of a special sample holder that is used in conjunction with the in-place Everhart-Thornley detector. In addition, the EDX capabilities for imaging NPs, highlighting the promising potential with respect to exploitation of the sensitivity of the new large area silicon drift detector energy dispersive X-ray spectrometers were also investigated. The work was carried out in the frame of a large prenormative VAMAS (Versailles Project on Advanced Materials and Standards) project, dedicated to finding appropriate methods and procedures for traceable characterization of NP size and size distribution.

  6. Qdot Labeled Actin Super Resolution Motility Assay Measures Low Duty Cycle Muscle Myosin Step-Size

    Science.gov (United States)

    Wang, Yihua; Ajtai, Katalin; Burghardt, Thomas P.

    2013-01-01

    Myosin powers contraction in heart and skeletal muscle and is a leading target for mutations implicated in inheritable muscle diseases. During contraction, myosin transduces ATP free energy into the work of muscle shortening against resisting force. Muscle shortening involves relative sliding of myosin and actin filaments. Skeletal actin filaments were fluorescence labeled with a streptavidin conjugate quantum dot (Qdot) binding biotin-phalloidin on actin. Single Qdot’s were imaged in time with total internal reflection fluorescence microscopy then spatially localized to 1-3 nanometers using a super-resolution algorithm as they translated with actin over a surface coated with skeletal heavy meromyosin (sHMM) or full length β-cardiac myosin (MYH7). Average Qdot-actin velocity matches measurements with rhodamine-phalloidin labeled actin. The sHMM Qdot-actin velocity histogram contains low velocity events corresponding to actin translation in quantized steps of ~5 nm. The MYH7 velocity histogram has quantized steps at 3 and 8 nm in addition to 5 nm, and, larger compliance than sHMM depending on MYH7 surface concentration. Low duty cycle skeletal and cardiac myosin present challenges for a single molecule assay because actomyosin dissociates quickly and the freely moving element diffuses away. The in vitro motility assay has modestly more actomyosin interactions and methylcellulose inhibited diffusion to sustain the complex while preserving a subset of encounters that do not overlap in time on a single actin filament. A single myosin step is isolated in time and space then characterized using super-resolution. The approach provides quick, quantitative, and inexpensive step-size measurement for low duty cycle muscle myosin. PMID:23383646

  7. Silica Measurement with High Flow Rate Respirable Size Selective Samplers: A Field Study.

    Science.gov (United States)

    Lee, Taekhee; Harper, Martin; Kashon, Michael; Lee, Larry A; Healy, Catherine B; Coggins, Marie A; Susi, Pam; O'Brien, Andrew

    2016-04-01

    High and low flow rate respirable size selective samplers including the CIP10-R (10 l min(-1)), FSP10 (11.2 l min(-1)), GK2.69 (4.4 l min(-1)), 10-mm nylon (1.7 l min(-1)), and Higgins-Dewell type (2.2 l min(-1)) were compared via side-by-side sampling in workplaces for respirable crystalline silica measurement. Sampling was conducted at eight different occupational sites in the USA and five different stonemasonry sites in Ireland. A total of 536 (268 pairs) personal samples and 55 area samples were collected. Gravimetric analysis was used to determine respirable dust mass and X-ray diffraction analysis was used to determine quartz mass. Ratios of respirable dust mass concentration, quartz mass concentration, respirable dust mass, and quartz mass from high and low flow rate samplers were compared. In general, samplers did not show significant differences greater than 30% in respirable dust mass concentration and quartz mass concentration when outliers (ratio 3.0) were removed from the analysis. The frequency of samples above the limit of detection and limit of quantification of quartz was significantly higher for the CIP10-R and FSP10 samplers compared to low flow rate samplers, while the GK2.69 cyclone did not show significant difference from low flow rate samplers. High flow rate samplers collected significantly more respirable dust and quartz than low flow rate samplers as expected indicating that utilizing high flow rate samplers might improve precision in quartz measurement. Although the samplers did not show significant differences in respirable dust and quartz concentrations, other practical attributes might make them more or less suitable for personal sampling. Published by Oxford University Press on behalf of the British Occupational Hygiene Society 2015.

  8. Melt-Pool Temperature and Size Measurement During Direct Laser Sintering

    Energy Technology Data Exchange (ETDEWEB)

    List, III, Frederick Alyious [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Dinwiddie, Ralph Barton [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Carver, Keith [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Gockel, Joy E. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-08-01

    Additive manufacturing has demonstrated the ability to fabricate complex geometries and components not possible with conventional casting and machining. In many cases, industry has demonstrated the ability to fabricate complex geometries with improved efficiency and performance. However, qualification and certification of processes is challenging, leaving companies to focus on certification of material though design allowable based approaches. This significantly reduces the business case for additive manufacturing. Therefore, real time monitoring of the melt pool can be used to detect the development of flaws, such as porosity or un-sintered powder and aid in the certification process. Characteristics of the melt pool in the Direct Laser Sintering (DLS) process is also of great interest to modelers who are developing simulation models needed to improve and perfect the DLS process. Such models could provide a means to rapidly develop the optimum processing parameters for new alloy powders and optimize processing parameters for specific part geometries. Stratonics’ ThermaViz system will be integrated with the Renishaw DLS system in order to demonstrate its ability to measure melt pool size, shape and temperature. These results will be compared with data from an existing IR camera to determine the best approach for the determination of these critical parameters.

  9. Near-equilibrium measurement of quantum size effects using Kelvin probe force microscopy.

    Science.gov (United States)

    Späth, Thomas; Popp, Matthias; Pérez León, Carmen; Marz, Michael; Hoffmann-Vogel, Regina

    2017-06-14

    In nano-structures such as thin films electron confinement results in the quantization of energy levels in the direction perpendicular to the film. The discretization of the energy levels leads to the oscillatory dependence of many properties on the film thickness due to quantum size effects. Pb on Si(111) is a specially interesting system because a particular relationship between the Pb atomic layer thickness and its Fermi wavelength leads to a periodicity of the oscillation of two atomic layers. Here, we demonstrate how the combination of scanning force microscopy (SFM) and Kelvin probe force microscopy (KPFM) provides a reliable method to monitor the quantum oscillations in the work function of Pb ultra-thin film nano-structures on Si(111). Unlike other techniques, with SFM/KPFM we directly address single Pb islands, determine their height while suppressing the influence of electrostatic forces, and, in addition, simultaneously evaluate their local work function by measurements close to equilibrium, without current-dependent and non-equilibrium effects. Our results evidence even-odd oscillations in the work function as a function of the film thickness that decay linearly with the film thickness, proving that this method provides direct and precise information on the quantum states.

  10. Precision in the measurement of dairy feed fractions based on particle size.

    Directory of Open Access Journals (Sweden)

    Mauro Spanghero

    2010-01-01

    Full Text Available The aim of this research note is to evaluate the variability of the physical measurements obtained by a separator of feeds  for dairy cows based on particle size. Fresh samples of total mixed ration (TMR and corn silage were collected from four  dairy units and were immediately fractionated using a particle separator (NASCO®, Pennsylvania State University com-  posed of two sieves (diameters of 19 and 8 mm and a collector on the bottom. Repeatability expressed as standard devi-  ation was similar between fractions (>19, 8-19 and   +1.7 and +1.5% for corn silages, but when expressed as coefficient of variation there were, for both samples, large dif-  ferences between the values for fraction exceeding 19 mm (44.7 and 35.1 %, respectively for TMR and corn silages and  the middle (3.9 and 2.5 %, respectively for TMR and corn silages and bottom fractions (3.7 and 5.6 %, respectively for  TMR and corn silages. The between operator reproducibility was very close to repeatability and this indicates that the  operator’s contribution to the overall variability is marginal in comparison with residual variability. In conclusion, differ-  ent operators properly trained in the use of the NASCO® separator can produce satisfactory repeatable and reproducible  values for the middle and the bottom fractions. 

  11. Size specific indoor aerosol deposition measurements and derived I/O concentrations ratios

    Science.gov (United States)

    Fogh, Christian L.; Byrne, Miriam A.; Roed, Jørn; Goddard, Antony J. H.

    The process of aerosol deposition on indoor surfaces has implications for human exposure to particulate contaminants of both indoor and outdoor origin. In the radiological context, current accident models assume a uniform Dose Reduction Factor (DRF) of 0.5 for indoor residence during the outdoor passage of a radioactive aerosol cloud. To examine the general validity of this figure, indoor aerosol deposition have been determined in four houses. Monodisperse aerosol particles, with mass median aerodynamic diameters (MMAD) in the range of 0.5-5.5 μm, were labelled with neutron-activatable tracers and dispersed in unfurnished and furnished rooms; the decay rate of the particles was then inferred from analysis of sequential air samples. Allowing for the differences in furnishing and level of occupancy between the tests, consistent aerosol deposition velocities were determined and, for furnished rooms, the following empirical expression, relating the particles' MMAD ( dp in μm) to the indoor deposition velocity ( vd, in 10 -4 m s -1) was derived: vd = 0.48 + 0.60 dp ( r = 0.93). Using this formula, particle size-specific DRFs were determined and found to be in good agreement with previous measurements of I/O ratios for fine and coarse particles. It was concluded that, for realistic dose estimates, a radioisotope-specific factor may be merited.

  12. The effect of noise and sampling size on vorticity measurements in rotating fluids

    Science.gov (United States)

    Wong, Kelvin K. L.; Kelso, Richard M.; Mazumdar, Jagannath; Abbott, Derek

    2008-11-01

    This paper describes a new technique for presenting information based on given flow images. Using a multistep first order differentiation technique, we are able to map in two dimensions, vorticity of fluid within a region of investigation. We can then present the distribution of this property in space by means of a color intensity map. In particular, the state of fluid rotation can be displayed using maps of vorticity flow values. The framework that is implemented can also be used to quantify the vortices using statistical properties which can be derived from such vorticity flow maps. To test our methodology, we have devised artificial vortical flow fields using an analytical formulation of a single vortex. Reliability of vorticity measurement from our results shows that the size of flow vector sampling and noise in flow field affect the generation of vorticity maps. Based on histograms of these maps, we are able to establish an optimised configuration that computes vorticity fields to approximate the ideal vortex statistically. The novel concept outlined in this study can be used to reduce fluctuations of noise in a vorticity calculation based on imperfect flow information without excessive loss of its features, and thereby improves the effectiveness of flow

  13. Measuring the size dependence of thermal conductivity of suspended graphene disks using null-point scanning thermal microscopy.

    Science.gov (United States)

    Hwang, Gwangseok; Kwon, Ohmyoung

    2016-03-07

    Using null-point scanning thermal microscopy (NP SThM), we have measured and analyzed the size dependence of the thermal conductivity of graphene. To do so, we rigorously re-derived the principal equation of NP SThM in terms of thermal property measurements so as to explain how this technique can be effectively used to quantitatively measure the local thermal resistance with nanoscale spatial resolution. This technique has already been proven to resolve the major problems of conventional SThM, and to quantitatively measure the temperature profile. Using NP SThM, we measured the variation in the thermal resistance of suspended chemical vapor deposition (CVD)-grown graphene disks with radii of 50-3680 nm from the center to the edge with respect to the size. By thoroughly analyzing the size dependence of the thermal resistance, we show that, with increasing graphene size, the ballistic resistance becomes more dominant in the thermal resistance experienced by a heat source of finite size and that the thermal conductivity experienced by such a heat source can even decrease. The results of this study reveal that the thermal conductivity of graphene detected by a heat source depends on the size of the heat source relative to that of the suspended graphene and on how the heat source and graphene are connected. As demonstrated in this study, NP SThM will be very useful for quantitative thermal characterization of not only CVD-grown graphene but also various other nanomaterials and nanodevices.

  14. An Ultra-Sensitive, Size Resolved Particle Mass Measurement Device Project

    Data.gov (United States)

    National Aeronautics and Space Administration — By providing size resolved compositional information, the Aerosol Mass Spectrometer (AMS) has greatly advanced understanding of aircraft particulate matter (PM)...

  15. An Ultra-Sensitive, Size Resolved Particle Mass Measurement Device Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The characterization of aircraft particulate matter (PM) emissions has benefited greatly by the Aerosol Mass Spectrometer (AMS) by providing size resolved...

  16. Vertical Variability of Rain Drop Size Distribution from Micro Rain Radar Measurements during IFloodS

    Science.gov (United States)

    Adirosi, Elisa; Tokay, Ali; Roberto, Nicoletta; Gorgucci, Eugenio; Montopoli, Mario; Baldini, Luca

    2017-04-01

    Ground based weather radars are highly used to generate rainfall products for meteorological and hydrological applications. However, weather radar quantitative rainfall estimation is obtained at a certain altitude that depends mainly on the radar elevation angle and on the distance from the radar. Therefore, depending on the vertical variability of rainfall, a time-height ambiguity between radar measurement and rainfall at the ground can affect the rainfall products. The vertically pointing radars (such as the Micro Rain Radar, MRR) are great tool to investigate the vertical variability of rainfall and its characteristics and ultimately, to fill the gap between the ground level and the first available radar elevation. Furthermore, the knowledge of rain Drop Size Distribution (DSD) variability is linked to the well-known problem of the non-uniform beam filling that is one of the main uncertainties of Global Precipitation Measurement (GPM) mission Dual frequency Precipitation Radar (DPR). During GPM Ground Validation Iowa Flood Studies (IFloodS) field experiment, data collected with 2D video disdrometers (2DVD), Autonomous OTT Parsivel2 Units (APU), and MRR profilers at different sites were available. In three different sites co-located APU, 2DVD and MRR are available and covered by the S-band Dual Polarimetric Doppler radar (NPOL). The first elevation height of the radar beam varies, among the three sites, between 70 m and 1100 m. The IFloodS set-up has been used to compare disdrometers, MRR and NPOL data and to evaluate the uncertainties of those measurements. First, the performance of disdrometers and MRR in determining different rainfall parameters at ground has been evaluated and then the MRR based parameters have been compared with the ones obtained from NPOL data at the lowest elevations. Furthermore, the vertical variability of DSD and integral rainfall parameters within the MRR bins (from ground to 1085 m each 35 m) has been investigated in order to provide

  17. Low-cost telemedicine device performing cell and particle size measurement based on lens-free shadow imaging technology.

    Science.gov (United States)

    Roy, Mohendra; Seo, Dongmin; Oh, Chang-Hyun; Nam, Myung-Hyun; Kim, Young Jun; Seo, Sungkyu

    2015-05-15

    Recent advances in lens-free shadow imaging technology have enabled a new class of cell imaging platform, which is a suitable candidate for point-of-care facilities. In this paper, we firstly demonstrate a compact and low-cost telemedicine device providing automated cell and particle size measurement based on lens-free shadow imaging technology. Using the generated shadow (or diffraction) patterns, the proposed approach can detect and measure the sizes of more than several hundreds of micro-objects simultaneously within a single digital image frame. In practical experiments, we defined four types of shadow parameters extracted from each micro-object shadow pattern, and found that a specific shadow parameter (peak-to-peak distance, PPD) demonstrated a linear relationship with the actual micro-object sizes. By using this information, a new algorithm suitable for operation on both a personal computer (PC) and a cell phone was also developed, providing automated size detection of poly-styrenemicro-beads and biological cells such as red blood cells, MCF-7, HepG2, and HeLa. Results from the proposed device were compared with those of a conventional optical microscope, demonstrating good agreement between two approaches. In contrast to other existing cell and particle size measurement approaches, such as Coulter counter, flow-cytometer, particle-size analyzer, and optical microscope, this device can provide accurate cell and particle size information with a 2 µm maximum resolution, at almost no cost (less than 100 USD), within a compact instrumentation size (9.3×9.0×9.0 cm(3)), and in a rapid manner (within 1 min). The proposed lens-free automated particle and cell size measurement device, based on shadow imaging technology, can be utilized as a powerful tool for many cell and particle handling procedures, including environmental, pharmaceutical, biological, and clinical applications. Copyright © 2014 Elsevier B.V. All rights reserved.

  18. Beyond Cohen's "d": Alternative Effect Size Measures for Between-Subject Designs

    Science.gov (United States)

    Peng, Chao-Ying Joanne; Chen, Li-Ting

    2014-01-01

    Given the long history of discussion of issues surrounding statistical testing and effect size indices and various attempts by the American Psychological Association and by the American Educational Research Association to encourage the reporting of effect size, most journals in education and psychology have witnessed an increase in effect size…

  19. Ultrasonic measurement of the liver size in normal adult Nigerians at ...

    African Journals Online (AJOL)

    Background: Clinically, liver size is estimated by palpation and percussion. However this method is not without limitation, which is overcome by use of ultrasound scan. The purpose of this study is to establish a normal range of liver size for adults in Nigeria through ultrasound imaging to assist in clinical evaluation of the liver ...

  20. Measurement of Dynamic Viscoelasticity of Full-Size Wood Composite Panels Using a Vibration Testing Method

    Science.gov (United States)

    Cheng Guan; Houjiang Zhang; John F. Hunt; Lujing Zhou; Dan Feng

    2016-01-01

    The dynamic viscoelasticity of full-size wood composite panels (WCPs) under the free-free vibrational state were determined by a vibration testing method. Vibration detection tests were performed on 194 pieces of three types of full-size WCPs (particleboard, medium density fiberboard, and plywood (PW)). The dynamic viscoelasticity from smaller specimens cut from the...

  1. Within-subject variation in BOLD-fMRI signal changes across repeated measurements: Quantification and implications for sample size

    NARCIS (Netherlands)

    Zandbelt, B.B.; Gladwin, T.E.; Raemaekers, M.; Buuren, M. van; Neggers, S.F.W.; Kahn, R.S.; Ramsey, N.F.; Vink, M.

    2008-01-01

    Functional magnetic resonance imaging (fMRI) can be used to detect experimental effects on brain activity across measurements. The success of such studies depends on the size of the experimental effect, the reliability of the measurements, and the number of subjects. Here, we report on the stability

  2. A novel system for rapid measurement of high-frequency magnetic properties of toroidal cores of different sizes

    CERN Document Server

    Derebasi, N; Moses, A J; Fox, D

    2000-01-01

    A novel system for power loss and B-H measurements on toroidal magnetic cores was built to operate up to 200 kHz. Measurement data taken using sophisticated software at 10 MHz sampling rate and 16-bit resolution shows the system is versatile and can be used to test a wide range of core sizes and materials with an error <+-3%.

  3. The SailBuoy remotely-controlled unmanned vessel: Measurements of near surface temperature, salinity and oxygen concentration in the Northern Gulf of Mexico

    OpenAIRE

    Ghani, Mahmud Hasan; Hole, Lars R.; Fer, Ilker; Kourafalou, Vassiliki H.; Wienders, Nicolas; Kang, HeeSook; Drushka, Kyla; Peddie, David

    2014-01-01

    An experimental deployment of a new type of unmanned vessel is presented. The Christian Michelsen Research SailBuoy, a remotely-controlled surface vehicle, sampled near-surface properties during a two-month mission in the northern Gulf of Mexico in March–May, 2013. Averaged over the entire deployment, the vessel speed over ground was View the MathML source42±30cm s⎻¹ (± one standard deviation) with a maximum of View the MathML source180cm s⎻¹. During the 62 days of the mission, the SailBuoy c...

  4. Ocular accommodation and cognitive demand: An additional indicator besides pupil size and cardiovascular measures?

    Directory of Open Access Journals (Sweden)

    Jaschinski Wolfgang

    2008-08-01

    Full Text Available Abstract Background The aim of the present study was to assess accommodation as a possible indicator of changes in the autonomic balance caused by altered cognitive demand. Accounting for accommodative responses from a human factors perspective may be motivated by the interest of designing virtual image displays or by establishing an autonomic indicator that allows for remote measurement at the human eye. Heart period, pulse transit time, and the pupillary response were considered as reference for possible closed-loop accommodative effects. Cognitive demand was varied by presenting monocularly numbers at a viewing distance of 5 D (20 cm which had to be read, added or multiplied; further, letters were presented in a "n-back" task. Results Cardiovascular parameters and pupil size indicated a change in autonomic balance, while error rates and reaction time confirmed the increased cognitive demand during task processing. An observed decrease in accommodation could not be attributed to the cognitive demand itself for two reasons: (1 the cognitive demand induced a shift in gaze direction which, for methodological reasons, accounted for a substantial part of the observed accommodative changes. (2 Remaining effects disappeared when the correctness of task processing was taken into account. Conclusion Although the expectation of accommodation as possible autonomic indicator of cognitive demand was not confirmed, the present results are informative for the field of applied psychophysiology noting that it seems not to be worthwhile to include closed-loop accommodation in future studies. From a human factors perspective, expected changes of accommodation due to cognitive demand are of minor importance for design specifications – of, for example, complex visual displays.

  5. Limitations of Significance Testing in Clinical Research: A Review of Multiple Comparison Corrections and Effect Size Calculations with Correlated Measures.

    Science.gov (United States)

    Vasilopoulos, Terrie; Morey, Timothy E; Dhatariya, Ketan; Rice, Mark J

    2016-03-01

    Modern clinical research commonly uses complex designs with multiple related outcomes, including repeated-measures designs. While multiple comparison corrections and effect size calculations are needed to more accurately assess an intervention's significance and impact, understanding the limitations of these methods in the case of dependency and correlation is important. In this review, we outline methods for multiple comparison corrections and effect size calculations and considerations in cases of correlation and summarize relevant simulation studies to illustrate these concepts.

  6. Size and Reversal Learning in the Beagle Dog as a Measure of Executive Function and Inhibitory Control in Aging

    OpenAIRE

    Tapp, P. Dwight; Siwak, Christina T.; Estrada, Jimena; Head, Elizabeth; Muggenburg, Bruce A.; Cotman, Carl W.; Milgram, Norton W.

    2003-01-01

    Several studies converge on the idea that executive processes age earlier than other cognitive processes. As part of a larger effort to investigate age-related changes in executive processes in the dog, inhibitory control was measured in young, middle-aged, old, and senior dogs using size discrimination learning and reversal procedures. Compared to young and middle-aged dogs, old and senior dogs were impaired on both the initial learning of the size task and the reversal of original reward co...

  7. Pressure vessel design manual

    CERN Document Server

    Moss, Dennis R

    2013-01-01

    Pressure vessels are closed containers designed to hold gases or liquids at a pressure substantially different from the ambient pressure. They have a variety of applications in industry, including in oil refineries, nuclear reactors, vehicle airbrake reservoirs, and more. The pressure differential with such vessels is dangerous, and due to the risk of accident and fatality around their use, the design, manufacture, operation and inspection of pressure vessels is regulated by engineering authorities and guided by legal codes and standards. Pressure Vessel Design Manual is a solutions-focused guide to the many problems and technical challenges involved in the design of pressure vessels to match stringent standards and codes. It brings together otherwise scattered information and explanations into one easy-to-use resource to minimize research and take readers from problem to solution in the most direct manner possible. * Covers almost all problems that a working pressure vessel designer can expect to face, with ...

  8. HIGH-ENERGY X-RAY PINHOLE CAMERA FOR HIGH-RESOLUTION ELECTRON BEAM SIZE MEASUREMENTS

    Energy Technology Data Exchange (ETDEWEB)

    Yang, B.; Morgan, J.; Lee, S.H.; Shang, H.

    2017-03-25

    The Advanced Photon Source (APS) is developing a multi-bend achromat (MBA) lattice based storage ring as the next major upgrade, featuring a 20-fold reduction in emittance. Combining the reduction of beta functions, the electron beam sizes at bend magnet sources may be reduced to reach 5 – 10 µm for 10% vertical coupling. The x-ray pinhole camera currently used for beam size monitoring will not be adequate for the new task. By increasing the operating photon energy to 120 – 200 keV, the pinhole camera’s resolution is expected to reach below 4 µm. The peak height of the pinhole image will be used to monitor relative changes of the beam sizes and enable the feedback control of the emittance. We present the simulation and the design of a beam size monitor for the APS storage ring.

  9. Measurement of the defect size by shearography or other interferometric techniques

    Science.gov (United States)

    Michel, Fabrice; Renotte, Yvon L.; Habraken, Serge

    2012-03-01

    Shearography is an interferometric technique suitable for detecting defects because they yield singular fringes and high phase values in wrapped and unwrapped phasemaps, respectively. We propose a methodology that leads to the defect size from unwrapped phasemap by extracting the size of the high phase values area. The area size is evaluated, thanks to a wavelet transform algorithm that enables the location of its borders. The performances of the methodology and of the algorithm have been tested by applying them on a defect where the size is known. An error less than 1.5% root mean square was reached. Our approach is independent of the shearing amount and of the phase profile, and it can be extended for other interferometric techniques.

  10. Laminae and grain-size measures in beach sediments, east coast beaches, India

    Digital Repository Service at National Institute of Oceanography (India)

    Chauhan, O.S.

    in these parameters. Individual layers have wider ranges of mean sizes, variable sorting, skewness and kurtosis values. These variations are pronounced and are observed in fine grained dark laminae as well as interlaminae space. These results suggest variations...

  11. Aerosol size and chemical composition measurements at the Polar Environment Atmospheric Research Lab (PEARL) in Eureka, Nunavut

    Science.gov (United States)

    Hayes, P. L.; Tremblay, S.; Chang, R. Y. W.; Leaitch, R.; Kolonjari, F.; O'Neill, N. T.; Chaubey, J. P.; AboEl Fetouh, Y.; Fogal, P.; Drummond, J. R.

    2016-12-01

    This study presents observations of aerosol chemical composition and particle number size distribution at the Polar Environment Atmospheric Research Laboratory (PEARL) in the Canadian High Arctic (80N, 86W). The current aerosol measurement program at PEARL has been ongoing for more than a year providing long-term observations of Arctic aerosol size distributions for both coarse and fine modes. Particle nucleation events were frequently observed during the summers of 2015 and 2016. The size distribution data are also compared against similar measurements taken at the Alert Global Atmospheric Watch Observatory (82N, 62W) for July and August 2015. The nucleation events are correlated at the two sites, despite a distance of approximately 500 km, suggesting regional conditions favorable for particle nucleation and growth during this period. Size resolved chemical composition measurements were also carried out using an aerosol mass spectrometer. The smallest measured particles between 40 and 60 nm are almost entirely organic aerosol (OA) indicating that the condensation of organic vapors is responsible for particle growth events and possibly particle nucleation. This conclusion is further supported by the relatively high oxygen content of the OA, which is consistent with secondary formation of OA via atmospheric oxidation.Lastly, surface measurements of the aerosol scattering coefficient are compared against the coefficient values calculated using Mie theory and the measured aerosol size distribution. Both the actual and the calculated scattering coefficients are then compared to sun photometer measurements to understand the relationship between surface and columnar aerosol optical properties. The measurements at PEARL provide a unique combination of surface and columnar data sets on aerosols in the High Arctic, a region where such measurements are scarce despite the important impact of aerosols on Arctic climate.PEARL research is supported by the Natural Sciences and

  12. Flash X-Ray (FXR) Accelerator Optimization Electronic Time-Resolved Measurement of X-Ray Source Size

    Energy Technology Data Exchange (ETDEWEB)

    Jacob, J; Ong, M; Wargo, P

    2005-07-21

    Lawrence Livermore National Laboratory (LLNL) is currently investigating various approaches to minimize the x-ray source size on the Flash X-Ray (FXR) linear induction accelerator in order to improve x-ray flux and increase resolution for hydrodynamic radiography experiments. In order to effectively gauge improvements to final x-ray source size, a fast, robust, and accurate system for measuring the spot size is required. Timely feedback on x-ray source size allows new and improved accelerator tunes to be deployed and optimized within the limited run-time constraints of a production facility with a busy experimental schedule; in addition, time-resolved measurement capability allows the investigation of not only the time-averaged source size, but also the evolution of the source size, centroid position, and x-ray dose throughout the 70 ns beam pulse. Combined with time-resolved measurements of electron beam parameters such as emittance, energy, and current, key limiting factors can be identified, modeled, and optimized for the best possible spot size. Roll-bar techniques are a widely used method for x-ray source size measurement, and have been the method of choice at FXR for many years. A thick bar of tungsten or other dense metal with a sharp edge is inserted into the path of the x-ray beam so as to heavily attenuate the lower half of the beam, resulting in a half-light, half-dark image as seen downstream of the roll-bar; by measuring the width of the transition from light to dark across the edge of the roll-bar, the source size can be deduced. For many years, film has been the imaging medium of choice for roll-bar measurements thanks to its high resolution, linear response, and excellent contrast ratio. Film measurements, however, are fairly cumbersome and require considerable setup and analysis time; moreover, with the continuing trend towards all-electronic measurement systems, film is becoming increasingly difficult and expensive to procure. Here, we shall

  13. Size measurement of the thyroid gland on a magnified pinhole thyroid scan using an ultrasonic device measuring distance from the pinhole to the thyroid gland.

    Science.gov (United States)

    Ahn, Byeong-Cheol; Ahn, Gilhwan; Kim, Do-Hoon; Kim, Kyoung Dong; Jeong, Shin Young; Lee, Sang-Woo; Lee, Jaetae

    2015-02-01

    Pinhole has been used for magnification of gamma camera images and is valuable for imaging of small organs, such as thyroid; however, size of the organ cannot be measured on the image due to variable degree of magnification by distance between the pinhole and the organ. The aim of this study was to develop a true size measuring system (TSM system) on magnified pinhole thyroid scan using an ultrasonic sensor. An ultrasonic device capable of measuring the distance from the pinhole to the skin overlying the thyroid gland was manufactured using a ~40 kHz piezoelectric-transducer-based sensor, and its accuracy was tested. An interface program was developed and fused with the ultrasonic device for development of the TSM system. Accuracy of the TSM system for measuring size was tested with phantom images and 35 thyroid scans. The ultrasonic device accurately measured the distance from the pinhole to the skin over the thyroid gland and the measured values were highly reproducible (6 cm; 6.02 ± 0.04 cm, 8 cm; 8.00 ± 0.05 cm, 10 cm; 10.00 ± 0.05 cm). Distance on the phantom image corrected by the TSM system was almost the same as the true distance. Size of the thyroid on the pinhole image was larger (+67.3 to 103.1 %) than the true thyroid size on the parallel-hole image and the magnification decreased by increase of the distance between the pinhole and the skin over the thyroid gland. However, size of the thyroid obtained using the TSM system was almost equal (-2.1 to +3.6 %) to the true thyroid size on the parallel-hole image. We developed the TSM system for magnified pinhole images using a distance measuring ultrasonic sensor. Size of the thyroid on the magnified pinhole image obtained using the system was almost the same as the true thyroid size. The TSM system can be applied to obtain accurate size of the thyroid gland or lesions in the thyroid gland on pinhole thyroid scan.

  14. Intraobserver and interobserver variability in CT angiography and MR angiography measurements of the size of cerebral aneurysms

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hye Jeong [Hallym University College of Medicine, Department of Radiology, Kangnam Sacred Heart Hospital, Seoul (Korea, Republic of); Yoon, Dae Young; Lee, Hyung Jin [Hallym University College of Medicine, Department of Radiology, Kangdong Seong-Sim Hospital, Seoul (Korea, Republic of); Kim, Eun Soo [Hallym University College of Medicine, Department of Radiology, Hallym University Sacred Heart Hospital, Anyang, Gyeonggi-do (Korea, Republic of); Jeon, Hong Jun; Lee, Jong Young; Cho, Byung-Moon [Hallym University College of Medicine, Department of Neurosurgery, Kangdong Seong-Sim Hospital, Seoul (Korea, Republic of)

    2017-05-15

    Accurate and reliable measurement of aneurysm size is important for treatment planning. The purpose of this study was to determine intraobserver and interobserver variability of CTA and MRA for measurement of the size of cerebral aneurysms. Thirty patients with 33 unruptured cerebral aneurysms (saccular, >3 mm in their maximal dimension, with no daughter sacs or lobulations) who underwent 256-row multislice CTA, 3-D TOF MRA at 3.0T, and 3D rotational angiography (3DRA) were retrospectively analyzed. Three independent observers measured the neck, height, and width of the aneurysms using the CTA and MRA images. Intraobserver and interobserver variability of CTA and MRA measurements was evaluated using the standardized difference and intraclass correlation coefficient, with 3DRA measurements as the reference standard. In addition, the mean values of the measurements using CTA and MRA were compared with those using 3DRA. The overall intraobserver and interobserver standardized differences in CTA/MRA were 12.83-15.92%/13.48-17.45% and 14.08-17.00%/12.08-17.67%, respectively. The overall intraobserver and interobserver intraclass correlation coefficients of CTA/MRA were 0.88-0.98/0.84-0.96 and 0.86-0.98/0.85-0.95, respectively. Compared to the height and width measurements, measurements of the neck dimensions showed higher intraobserver and interobserver variability. The sizes of the cerebral aneurysms measured by CTA and MRA were 1.13-9.26 and 5.20-9.67% larger than those measured by 3DRA, respectively; however, these differences were not statistically significant. There were no noticeable differences between intraobserver and interobserver variability for both CTA- and MRA-based measurements of the size of cerebral aneurysms. (orig.)

  15. Maury Journals - German Vessels

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — German vessels observations, after the 1853 Brussels Conference that set International Maritime Standards, modeled after Maury Marine Standard Observations.

  16. Measurement of bubble size distribution in a gas-liquid foam using pulsed-field gradient nuclear magnetic resonance.

    Science.gov (United States)

    Stevenson, Paul; Sederman, Andrew J; Mantle, Mick D; Li, Xueliang; Gladden, Lynn F

    2010-12-01

    Pulsed-field gradient nuclear magnetic resonance, previously used for measuring droplet size distributions in emulsions, has been used to measure bubble size distributions in a non-overflowing pneumatic gas-liquid foam that has been created by sparging propane into an aqueous solution of 1.5g/l (5.20mM) SDS. The bubble size distributions measured were reproducible and approximated a Weibull distribution. However, the bubble size distributions did not materially change with position at which they were measured within the froth. An analysis of foam coarsening due to Ostwald ripening in a non-overflowing foam indicates that, for the experimental conditions employed, one would not expect this to be a significant effect. It is therefore apparent that the eventual collapse of the foam is due to bubble bursting (or surface coalescence) rather than Ostwald ripening. This surface coalescence occurs because of evaporation from the free surface of the foam. An analytical solution for the liquid fraction profile for a certain class of non-overflowing pneumatic foam is given, and a mean bubble size that is appropriate for drainage calculations is suggested. Copyright © 2010 Elsevier Inc. All rights reserved.

  17. Measurement of bubble size distributions in vesiculated rocks with implications for quantitative estimation of eruption processes

    Science.gov (United States)

    Toramaru, Atsushi

    1990-10-01

    This paper outlines methods for determining a bubble size distribution (BSD) and the moments of the BSD function in vesiculated clasts produced by volcanic eruptions. It reports the results of applications of the methods to 11 natural samples and discusses the implications for quantitative estimates of eruption processes. The analysis is based on a quantitative morphological (stereological) method for 2-dimensional imaging of cross-sections of samples. One method determines, with some assumptions, the complete shape of the BSD function from the chord lengths cut by bubbles. The other determines the 1st, 2nd and 3rd moments of distribution functions by measurement of the number of bubbles per unit area, the surface area per unit volume, and the volume fraction of bubbles. Comparison of procedures and results of these two distinct methods shows that the latter yields rather more reliable results than the former, though the results coincide in absolute and relative magnitudes. Results of the analysis for vesiculated rocks from eleven subPlinian to Plinian eruptions show some interesting systematic correlations both between moments of the BSD and between a moment and the eruption column height or the SiO 2 content of magma. These correlations are successfully interpreted in terms of the nucleation and growth processes of bubbles in ascending magmas. This suggests that bubble coalescence does not predominate in sub-Plinian to Plinian explosive eruptions. The moment-moment correlations put constraints on the style of the nucleation and growth process of bubbles. The scaling argument suggests that a single nucleation event and subsequent growth with any kind of bubble interaction under continuous depressurization, which leads to an intermediate growth law between the diffusional growth ( R m ∝ t {2}/{3}) at a constant depressurization rate and the Ostwald ripening ( R m ∝ t {1}/{3}) under a constant pressure, where Rm and t are the mean radius of bubble and the

  18. Size measurement uncertainties of near-monodisperse, near-spherical nanoparticles using transmission electron microscopy and particle-tracking analysis

    Science.gov (United States)

    De Temmerman, Pieter-Jan; Verleysen, Eveline; Lammertyn, Jeroen; Mast, Jan

    2014-10-01

    Particle-tracking analysis (PTA) in combination with systematic imaging, automatic image analysis, and automatic data processing is validated for size measurements. Transmission electron microscopy (TEM) in combination with a systematic selection procedure for unbiased random image collection, semiautomatic image analysis, and data processing is validated for size, shape, and surface topology measurements. PTA is investigated as an alternative for TEM for the determination of the particle size in the framework of the EC definition of nanomaterial. The intra-laboratory validation study assessing the precision and accuracy of the TEM and PTA methods consists of series of measurements on three gold reference materials with mean area-equivalent circular diameters of 8.9 nm (RM-8011), 27.6 nm (RM-8012), and 56.0 nm (RM-8013), and two polystyrene materials with modal hydrodynamic diameters of 102 nm (P1) and 202 nm (H1). By obtaining a high level of automation, PTA proves to give precise and non-biased results for the modal hydrodynamic diameter in size range between 30 and 200 nm, and TEM proves to give precise and non-biased results for the mean area-equivalent circular diameter in the size range between 8 and 200 nm of the investigated near-monomodal near-spherical materials. The expanded uncertainties of PTA are about 9 % and are determined mainly by the repeatability uncertainty. This uncertainty is two times higher than the expanded uncertainty of 4 % obtained by TEM for analyses on identical materials. For the investigated near-monomodal and near-spherical materials, PTA can be used as an alternative to TEM for measuring the particle size, with exception of 8.9 nm gold, because this material has a size below the detection limit of PTA.

  19. Direct measurement of the critical pore size in a model membrane

    CERN Document Server

    Ilton, Mark; Dalnoki-Veress, Kari

    2016-01-01

    We study pore nucleation in a model membrane system, a freestanding polymer film. Nucleated pores smaller than a critical size close, while pores larger than the critical size grow. Holes of varying size were purposefully prepared in liquid polymer films, and their evolution in time was monitored using optical and atomic force microscopy to extract a critical radius. The critical radius scales linearly with film thickness for a homopolymer film. The results agree with a simple model which takes into account the energy cost due to surface area at the edge of the pore. The energy cost at the edge of the pore is experimentally varied by using a lamellar-forming diblock copolymer membrane. The underlying molecular architecture causes increased frustration at the pore edge resulting in an enhanced cost of pore formation.

  20. Estimate of size distribution of charged MSPs measured in situ in winter during the WADIS-2 sounding rocket campaign

    Directory of Open Access Journals (Sweden)

    H. Asmus

    2017-08-01

    Full Text Available We present results of in situ measurements of mesosphere–lower thermosphere dusty-plasma densities including electrons, positive ions and charged aerosols conducted during the WADIS-2 sounding rocket campaign. The neutral air density was also measured, allowing for robust derivation of turbulence energy dissipation rates. A unique feature of these measurements is that they were done in a true common volume and with high spatial resolution. This allows for a reliable derivation of mean sizes and a size distribution function for the charged meteor smoke particles (MSPs. The mean particle radius derived from Schmidt numbers obtained from electron density fluctuations was ∼ 0.56 nm. We assumed a lognormal size distribution of the charged meteor smoke particles and derived the distribution width of 1.66 based on in situ-measured densities of different plasma constituents. We found that layers of enhanced meteor smoke particles' density measured by the particle detector coincide with enhanced Schmidt numbers obtained from the electron and neutral density fluctuations. Thus, we found that large particles with sizes  > 1 nm were stratified in layers of  ∼ 1 km thickness and lying some kilometers apart from each other.

  1. Estimate of size distribution of charged MSPs measured in situ in winter during the WADIS-2 sounding rocket campaign

    Science.gov (United States)

    Asmus, Heiner; Staszak, Tristan; Strelnikov, Boris; Lübken, Franz-Josef; Friedrich, Martin; Rapp, Markus

    2017-08-01

    We present results of in situ measurements of mesosphere-lower thermosphere dusty-plasma densities including electrons, positive ions and charged aerosols conducted during the WADIS-2 sounding rocket campaign. The neutral air density was also measured, allowing for robust derivation of turbulence energy dissipation rates. A unique feature of these measurements is that they were done in a true common volume and with high spatial resolution. This allows for a reliable derivation of mean sizes and a size distribution function for the charged meteor smoke particles (MSPs). The mean particle radius derived from Schmidt numbers obtained from electron density fluctuations was ˜ 0.56 nm. We assumed a lognormal size distribution of the charged meteor smoke particles and derived the distribution width of 1.66 based on in situ-measured densities of different plasma constituents. We found that layers of enhanced meteor smoke particles' density measured by the particle detector coincide with enhanced Schmidt numbers obtained from the electron and neutral density fluctuations. Thus, we found that large particles with sizes > 1 nm were stratified in layers of ˜ 1 km thickness and lying some kilometers apart from each other.

  2. Analysis of EBSD Grain Size Measurements Using Microstructure Simulations and a Customizable Pattern Matching Library for Grain Perimeter Estimation

    Science.gov (United States)

    Coutinho, Y. A.; Rooney, S. C. K.; Payton, E. J.

    2017-05-01

    Grain size data from electron backscatter diffraction (EBSD) maps are often reported as the mean of the circle equivalent diameters of the measured grain areas. Circle equivalent diameters are not directly comparable to the lineal intercept measurements more historically common for grain size characterization in analog optical microscopy. While the value of mean lineal intercept is the same in 2D and 3D for a given probe direction, the mean 2D circle equivalent section diameter is not directly related to any 3D property. Estimation of mean lineal intercept from circle equivalent diameter is usually carried out by again assuming feature circularity, despite the obvious corners that are inherent to grains from the requirements of space filling. A direct conversion between section areas and lineal intercepts can be performed if the grain perimeters are known. In the present work, a novel pattern matching library approach is investigated for measurement of grain perimeters using simulated 2D EBSD maps. The results are compared to alternative approaches for perimeter measurement and assessed with respect to spatial resolution, grain size distribution parameters, and relevant ASTM and ISO measurement standards. The benefits and drawbacks of each approach are discussed. Empirical estimators for conversion between lineal intercept, circle equivalent diameter, and ASTM grain size number are presented.

  3. Using portable particle sizing instrumentation to rapidly measure the penetration of fine and ultrafine particles in unoccupied residences.

    Science.gov (United States)

    Zhao, H; Stephens, B

    2017-01-01

    Much of human exposure to particulate matter of outdoor origin occurs inside buildings, particularly in residences. The particle penetration factor through leaks in a building's exterior enclosure assembly is a key parameter that governs the infiltration of outdoor particles. However, experimental data for size-resolved particle penetration factors in real buildings, as well as penetration factors for fine particles less than 2.5 μm (PM2.5 ) and ultrafine particles less than 100 nm (UFPs), remain limited, in part because of previous limitations in instrumentation and experimental methods. Here, we report on the development and application of a modified test method that utilizes portable particle sizing instrumentation to measure size-resolved infiltration factors and envelope penetration factors for 0.01-2.5 μm particles, which are then used to estimate penetration factors for integral measures of UFPs and PM2.5 . Eleven replicate measurements were made in an unoccupied apartment unit in Chicago, IL to evaluate the accuracy and repeatability of the test procedure and solution methods. Mean estimates of size-resolved penetration factors ranged from 0.41 ± 0.14 to 0.73 ± 0.05 across the range of measured particle sizes, while mean estimates of penetration factors for integral measures of UFPs and PM2.5 were 0.67 ± 0.05 and 0.73 ± 0.05, respectively. Average relative uncertainties for all particle sizes/classes were less than 20%. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  4. Validation of two-dimensional and three-dimensional measurements of subpleural alveolar size parameters by optical coherence tomography.

    Science.gov (United States)

    Unglert, Carolin I; Warger, William C; Hostens, Jeroen; Namati, Eman; Birngruber, Reginald; Bouma, Brett E; Tearney, Guillermo J

    2012-12-01

    Optical coherence tomography (OCT) has been increasingly used for imaging pulmonary alveoli. Only a few studies, however, have quantified individual alveolar areas, and the validity of alveolar volumes represented within OCT images has not been shown. To validate quantitative measurements of alveoli from OCT images, we compared the cross-sectional area, perimeter, volume, and surface area of matched subpleural alveoli from microcomputed tomography (micro-CT) and OCT images of fixed air-filled swine samples. The relative change in size between different alveoli was extremely well correlated (r>0.9, P<0.0001), but OCT images underestimated absolute sizes compared to micro-CT by 27% (area), 7% (perimeter), 46% (volume), and 25% (surface area) on average. We hypothesized that the differences resulted from refraction at the tissue-air interfaces and developed a ray-tracing model that approximates the reconstructed alveolar size within OCT images. Using this model and OCT measurements of the refractive index for lung tissue (1.41 for fresh, 1.53 for fixed), we derived equations to obtain absolute size measurements of superellipse and circular alveoli with the use of predictive correction factors. These methods and results should enable the quantification of alveolar sizes from OCT images in vivo.

  5. Model Of Navigational Safety Of Fishing Vessels In Polish EEZ

    Directory of Open Access Journals (Sweden)

    Przywarty Marcin

    2014-06-01

    Full Text Available The paper presents the assumptions of a simulation model for assessing the navigational safety of fishing vessels. The model consist of submodels of merchant and fishing vessels traffic, submodel of external condition and submodel of accident consequences. Paper present also a results of simulation experiment which was carried out for Polish EEZ. Model takes into account all Polish fishing vessels operating in the Polish EEZ with length more than 15 meters and the merchant vessels traffic in South Baltic Sea area. As a results positions of simulated collisions of fishing and merchant vessels, positions and sizes of simulated bunker spills and the positions of losses of fishing equipment were achieved.

  6. Vessel Sampling and Blood Flow Velocity Distribution With Vessel Diameter for Characterizing the Human Bulbar Conjunctival Microvasculature.

    Science.gov (United States)

    Wang, Liang; Yuan, Jin; Jiang, Hong; Yan, Wentao; Cintrón-Colón, Hector R; Perez, Victor L; DeBuc, Delia C; Feuer, William J; Wang, Jianhua

    2016-03-01

    This study determined (1) how many vessels (i.e., the vessel sampling) are needed to reliably characterize the bulbar conjunctival microvasculature and (2) if characteristic information can be obtained from the distribution histogram of the blood flow velocity and vessel diameter. Functional slitlamp biomicroscope was used to image hundreds of venules per subject. The bulbar conjunctiva in five healthy human subjects was imaged on six different locations in the temporal bulbar conjunctiva. The histograms of the diameter and velocity were plotted to examine whether the distribution was normal. Standard errors were calculated from the standard deviation and vessel sample size. The ratio of the standard error of the mean over the population mean was used to determine the sample size cutoff. The velocity was plotted as a function of the vessel diameter to display the distribution of the diameter and velocity. The results showed that the sampling size was approximately 15 vessels, which generated a standard error equivalent to 15% of the population mean from the total vessel population. The distributions of the diameter and velocity were not only unimodal, but also somewhat positively skewed and not normal. The blood flow velocity was related to the vessel diameter (r=0.23, P<0.05). This was the first study to determine the sampling size of the vessels and the distribution histogram of the blood flow velocity and vessel diameter, which may lead to a better understanding of the human microvascular system of the bulbar conjunctiva.

  7. PRESSURE-RESISTANT VESSEL

    NARCIS (Netherlands)

    Beukers, A.; De Jong, T.

    1997-01-01

    Abstract of WO 9717570 (A1) The invention is directed to a wheel-shaped pressure-resistant vessel for gaseous, liquid or liquefied material having a substantially rigid shape, said vessel comprising a substantially continuous shell of a fiber-reinforced resin having a central opening, an inner

  8. SMGE: strategic challenges and performance measurement in a small-sized company (case)

    NARCIS (Netherlands)

    MBA R. Vieveen; PhD B. Pesalj

    2015-01-01

    Case portrays the Superior Manufacturing Group Europe (SMGE), Barendrecht (Netherlands), a small-sized company doing business in the matting industry; facing challenges of how to sustain and improve its performance, by balancing between entrepreneurial initiative, and a need for strategic planning

  9. M(H) dependence and size distribution of SPIONs measured by atomic magnetometry

    CERN Document Server

    Colombo, Simone; Grujic, Zoran D; Dolgovskiy, Vladimir; Weis, Antoine

    2016-01-01

    We demonstrate that the quasistatic recording of the magnetic excitation function M(H) of superparamagnetic iron oxide magnetic nanoparticle (SPION) suspensions by an atomic magnetometer allows a precise determination of the sample's iron mass content mFe and the particle size distribution.

  10. Indication of the radiofrequency induced lesion size by pre-ablation measurements

    DEFF Research Database (Denmark)

    Stagegaard, Niels; Petersen, Helen Høgh; Chen, Xu

    2005-01-01

    BACKGROUND: During radiofrequency ablation of arrhythmias tissue heating and hence lesion size depend on electrode-tissue contact and cooling of the electrode tip caused by cavitary blood flow. These factors are unique and unknown for each catheter placement in the beating heart. A tool for asses......BACKGROUND: During radiofrequency ablation of arrhythmias tissue heating and hence lesion size depend on electrode-tissue contact and cooling of the electrode tip caused by cavitary blood flow. These factors are unique and unknown for each catheter placement in the beating heart. A tool...... for assessing these factors prior to ablation may indicate the lesion size which will be obtained for any given catheter position. METHODS AND RESULTS: Radiofrequency ablation was performed in vitro on strips of left ventricular porcine myocardium during two different levels of convective cooling (0 or 0.1 m......, during unchanged conditions, radiofrequency ablation was performed as either temperature-controlled, power-controlled or irrigated tip ablation and lesion size was determined. DeltaIMP increased significantly (P

  11. Sample size and repeated measures required in studies of foods in the homes of African-American families.

    Science.gov (United States)

    Stevens, June; Bryant, Maria; Wang, Chin-Hua; Cai, Jianwen; Bentley, Margaret E

    2012-06-01

    Measurement of the home food environment is of interest to researchers because it affects food intake and is a feasible target for nutrition interventions. The objective of this study was to provide estimates to aid the calculation of sample size and number of repeated measures needed in studies of nutrients and foods in the home. We inventoried all foods in the homes of 80 African-American first-time mothers and determined 6 nutrient-related attributes. Sixty-three households were measured 3 times, 11 were measured twice, and 6 were measured once, producing 217 inventories collected at ~2-mo intervals. Following log transformations, number of foods, total energy, dietary fiber, and fat required only one measurement per household to achieve a correlation of 0.8 between the observed and true values. For percent energy from fat and energy density, 3 and 2 repeated measurements, respectively, were needed to achieve a correlation of 0.8. A sample size of 252 was needed to detect a difference of 25% of an SD in total energy with one measurement compared with 213 with 3 repeated measurements. Macronutrient characteristics of household foods appeared relatively stable over a 6-mo period and only 1 or 2 repeated measures of households may be sufficient for an efficient study design.

  12. The variance of dispersion measure of high-redshift transient objects as a probe of ionized bubble size during reionization

    Science.gov (United States)

    Yoshiura, Shintaro; Takahashi, Keitaro

    2018-01-01

    The dispersion measure (DM) of high-redshift (z ≳ 6) transient objects such as fast radio bursts can be a powerful tool to probe the intergalactic medium during the Epoch of Reionization. In this paper, we study the variance of the DMs of objects with the same redshift as a potential probe of the size distribution of ionized bubbles. We calculate the DM variance with a simple model with randomly distributed spherical bubbles. It is found that the DM variance reflects the characteristics of the probability distribution of the bubble size. We find that the variance can be measured precisely enough to obtain the information on the typical size with a few hundred sources at a single redshift.

  13. Effects of voxel size and resolution on the accuracy of endodontic length measurement using cone beam computed tomography.

    Science.gov (United States)

    Aktan, Ali Murat; Yildirim, Cihan; Karataşlıoğlu, Emrah; Çiftçi, Mehmet Ertuğrul; Aksoy, Fatih

    2016-11-01

    An accurate determination of the working length is indispensable for successful endodontic treatment. The aim of this study was to determine the influence of the voxel size and resolution of CBCT on measuring root canal working length. Thirty extracted single-rooted permanent teeth were used for this study. The working lengths of the teeth were determined by a researcher inserted a K-file into each canal until the tip became visible through the major foramen. The file was withdrawn until its tip was seen at the level of the coronal-most border of the major foramen under. The rubber stop was adjusted to the occlusal reference and the distance from the stop to the false tip was measured with digital calipers and recorded as the actual working length. The CBCT images were obtained with a Planmeca ProMax 3D Mid (Planmeca, Helsinki, Finland) using four sets of settings: from voxel size 0.5mm to voxel size 1.0mm. These measurements were compared with actual lengths (as a control group) using Analysis of Variance and the Dunnett Post Hoc Test. The Pearson correlation coefficient (r) and 95% confidence intervals were calculated to compare all measurement methods. The significance level was set at Plength. A highest correlation was found between the actual length and smallest voxel size and highest CBCT measurements (r=0.94). CBCT imaging can be used endodontic working length measurement and the smallest voxel size and highest resolution yielded more accurate results. Copyright © 2016 Elsevier GmbH. All rights reserved.

  14. Development of an ejecta particle size measurement diagnostic based on Mie scattering

    Energy Technology Data Exchange (ETDEWEB)

    Schauer, Martin Michael [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Buttler, William Tillman [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Frayer, Daniel K. [National Security Tech, Inc., Los Alamos, NM (United States); Grover, Michael [National Security Technologies, Santa Barbara, CA (United States). Special Technologies Lab.; Monfared, Shabnam Kalighi [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Stevens, Gerald D. [National Security Technologies, Santa Barbara, CA (United States). Special Technologies Lab.; Stone, Benjamin J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Turley, William Dale [National Security Technologies, Santa Barbara, CA (United States). Special Technologies Lab.

    2017-09-27

    The goal of this work is to determine the feasibility of extracting the size of particles ejected from shocked metal surfaces (ejecta) from the angular distribution of light scattered by a cloud of such particles. The basis of the technique is the Mie theory of scattering, and implicit in this approach are the assumptions that the scattering particles are spherical and that single scattering conditions prevail. The meaning of this latter assumption, as far as experimental conditions are concerned, will become clear later. The solution to Maxwell’s equations for spherical particles illuminated by a plane electromagnetic wave was derived by Gustav Mie more than 100 years ago, but several modern treatises discuss this solution in great detail. The solution is a complicated series expansion of the scattered electric field, as well as the field within the particle, from which the total scattering and absorption cross sections as well as the angular distribution of scattered intensity can be calculated numerically. The detailed nature of the scattering is determined by the complex index of refraction of the particle material as well as the particle size parameter, x, which is the product of the wavenumber of the incident light and the particle radius, i.e. x = 2rπ= λ. Figure 1 shows the angular distribution of scattered light for different particle size parameters and two orthogonal incident light polarizations as calculated using the Mie solution. It is obvious that the scattering pattern is strongly dependent on the particle size parameter, becoming more forward-directed and less polarizationdependent as the particle size parameter increases. This trend forms the basis for the diagnostic design.

  15. Containment vessel drain system

    Energy Technology Data Exchange (ETDEWEB)

    Harris, Scott G.

    2018-01-30

    A system for draining a containment vessel may include a drain inlet located in a lower portion of the containment vessel. The containment vessel may be at least partially filled with a liquid, and the drain inlet may be located below a surface of the liquid. The system may further comprise an inlet located in an upper portion of the containment vessel. The inlet may be configured to insert pressurized gas into the containment vessel to form a pressurized region above the surface of the liquid, and the pressurized region may operate to apply a surface pressure that forces the liquid into the drain inlet. Additionally, a fluid separation device may be operatively connected to the drain inlet. The fluid separation device may be configured to separate the liquid from the pressurized gas that enters the drain inlet after the surface of the liquid falls below the drain inlet.

  16. Comparison of NMR and Dynamic Light Scattering for Measuring Diffusion Coefficients of Formulated Insulin: Implications for Particle Size Distribution Measurements in Drug Products.

    Science.gov (United States)

    Patil, Sharadrao M; Keire, David A; Chen, Kang

    2017-11-01

    Particle size distribution, a measurable physicochemical quantity, is a critical quality attribute of drug products that needs to be controlled in drug manufacturing. The non-invasive methods of dynamic light scattering (DLS) and Diffusion Ordered SpectroscopY (DOSY) NMR can be used to measure diffusion coefficient and derive the corresponding hydrodynamic radius. However, little is known about their use and sensitivity as analytical tools for particle size measurement of formulated protein therapeutics. Here, DLS and DOSY-NMR methods are shown to be orthogonal and yield identical diffusion coefficient results for a homogenous monomeric protein standard, ribonuclease A. However, different diffusion coefficients were observed for five insulin drug products measured using the two methods. DOSY-NMR yielded an averaged diffusion coefficient among fast exchanging insulin oligomers, ranging between dimer and hexamer in size. By contrast, DLS showed several distinct species, including dimer, hexamer, dodecamer and other aggregates. The heterogeneity or polydisperse nature of insulin oligomers in formulation caused DOSY-NMR and DLS results to differ from each other. DLS measurements provided more quality attributes and higher sensitivity to larger aggregates than DOSY-NMR. Nevertheless, each method was sensitive to a different range of particle sizes and complemented each other. The application of both methods increases the assurance of complex drug quality in this similarity comparison.

  17. AC loss measurements of model and full size 50mm SSC collider dipole magnets at Fermilab

    Energy Technology Data Exchange (ETDEWEB)

    Ozelis, J.P.; Delchamps, S.W.; Gourlay, S.; Jaffery, T.; Kinney, W.; Koska, W.; Kuchnir, M.; Lamm, M.J.; Mazur, P.O.; Orris, D.; Strait, J.; Wake, M. [Fermi National Accelerator Lab., Batavia, IL (United States); Dimarco, J.; Kuzminski, J.; Zheng, H. [Superconducting Super Collider Lab., Dallas, TX (United States)

    1992-09-01

    Tests have recently been performed at Fermilab in order to measure the energy losses due to eddy currents and iron and superconductor magnetization. These measurements were performed on six 1.5m long model magnets and eight 15m long full scale collider dipole magnets. AC losses were measured as a function of ramp rate using sawtooth ramps from 500, to 5000 Amps for both types of magnets, while bipolar studies were additionally performed on some of the short magnets. The measured magnet voltage and current for a complete cycle are digitally integrated to yield the energy loss per cycle. Measurement reproducibility is typically 5%, with good agreement between long magnet measurements and extrapolations from short magnet measurement results. Magnetization loss measurements among similar magnet types agree to within experimental error, while eddy current losses correlate strongly with the observed dependence of quench current on ramp rate.

  18. Analytical solutions to sampling effects in drop size distribution measurements during stationary rainfall: Estimation of bulk rainfall variables

    NARCIS (Netherlands)

    Uijlenhoet, R.; Porrà, J.M.; Sempere Torres, D.; Creutin, J.D.

    2006-01-01

    A stochastic model of the microstructure of rainfall is used to derive explicit expressions for the magnitude of the sampling fluctuations in rainfall properties estimated from raindrop size measurements in stationary rainfall. The model is a marked point process, in which the points represent the

  19. Comparison of Selvester QRS score with magnetic resonance imaging measured infarct size in patients with ST elevation myocardial infarction

    DEFF Research Database (Denmark)

    Carlsen, Esben A; Bang, Lia E; Ahtarovski, Kiril A

    2012-01-01

    Recent studies have shown that the Selvester QRS score is significantly correlated with delayed enhancement-magnetic resonance imaging (DE-MRI) measured myocardial infarct (MI) size in reperfused ST elevation MI (STEMI). This study further tests the hypothesis that Selvester QRS score correlates ...

  20. Computer-Assisted Measurement of Wound Size Associated with Self-Injurious Behavior

    Science.gov (United States)

    Wilson, David M.; Iwata, Brian A.; Bloom, Sarah E.

    2012-01-01

    We evaluated an inexpensive, efficient, and noninvasive technique for measuring tissue damage produced by self-injurious behavior (SIB). The technique involved computerized measurement of wound surface area (WSA) based on digital photographs. In Study 1, we compared photographic measurement to a more commonly used procedure, transparency…

  1. INFLUENCE OF WINDOW SIZE IN SMALL-WINDOW COLOR MEASUREMENT, PARTICULARLY OF TEETH

    NARCIS (Netherlands)

    BOLT, RA; TENBOSCH, JJ; COOPS, JC

    Tooth colour is often measured with a small window for illumination and measurement. This causes edge loss of the light, resulting in systematic errors in colour coordinates. This paper gives a quantification of the edge losses, and explains their cause. We measured reflectance spectra for 27

  2. In situ measurements of the oblique incidence sound absorption coefficient for finite sized absorbers

    DEFF Research Database (Denmark)

    Ottink, Marco; Brunskog, Jonas; Jeong, Cheol-Ho

    2016-01-01

    absorbers at oblique incidence in situ. Due to the edge diffraction effect, oblique incidence methods considering an infinite sample fail to measure the absorption coefficient at large incidence angles of finite samples. This paper aims for the development of a measurement method that accounts......Absorption coefficients are mostly measured in reverberation rooms or with impedance tubes. Since these methods are only suitable for measuring the random incidence and the normal incidence absorption coefficient, there exists an increasing need for absorption coefficient measurement of finite...... combines microphone array measurements over a finite sample with the sound field model in an inverse manner, is proposed. Besides, a temporal subtraction method, a microphone array method, impedance tube measurements, and an equivalent fluid model are used for validation. The finite surface method gives...

  3. Recent Advancements in Retinal Vessel Segmentation.

    Science.gov (United States)

    L Srinidhi, Chetan; Aparna, P; Rajan, Jeny

    2017-04-01

    Retinal vessel segmentation is a key step towards the accurate visualization, diagnosis, early treatment and surgery planning of ocular diseases. For the last two decades, a tremendous amount of research has been dedicated in developing automated methods for segmentation of blood vessels from retinal fundus images. Despite the fact, segmentation of retinal vessels still remains a challenging task due to the presence of abnormalities, varying size and shape of the vessels, non-uniform illumination and anatomical variability between subjects. In this paper, we carry out a systematic review of the most recent advancements in retinal vessel segmentation methods published in last five years. The objectives of this study are as follows: first, we discuss the most crucial preprocessing steps that are involved in accurate segmentation of vessels. Second, we review most recent state-of-the-art retinal vessel segmentation techniques which are classified into different categories based on their main principle. Third, we quantitatively analyse these methods in terms of its sensitivity, specificity, accuracy, area under the curve and discuss newly introduced performance metrics in current literature. Fourth, we discuss the advantages and limitations of the existing segmentation techniques. Finally, we provide an insight into active problems and possible future directions towards building successful computer-aided diagnostic system.

  4. Measurement of spleen size using gamma camera scintigraphy in essential thrombocythaemia

    Energy Technology Data Exchange (ETDEWEB)

    Revesz, P. (Department of Medicine, Oestra Hospital, University of Goeteborg, Goeteborg (Sweden)); Carneskog, J.; Wadenvik, H.; Kutti, J. (Haematology Section, Department of Medicine, Sahlgrenska Hospital, University of Goeteborg, Goeteborg (Sweden)); Jarneborn, L. (Department of Clinical Physiology, Oestra Hospital, University of Goeteborg, Goeteborg (Sweden))

    1993-09-01

    By using gamma camera imaging the spleen size was determined in 33 consecutive patients with essential thrombocythaemia (ET) and in 33 consecutive patients with reactive thrombocytosis (RT). All ET patients were newly diagnosed and had not received myelosuppressive treatment prior to study; they all fulfilled the criteria for ET as established by the Polycythemia Vera Study Group. In both posterior and lateral projections, the spleen area in the group of ET patients was significantly larger than in the RT patients. The present study has shown that 39% of ET patients at diagnosis have splenic enlargement. Evaluation of Spleen size is therefore a useful diagnostic test in patients presenting with unexplained thrombocytosis. (au) (15 refs.).

  5. Direct measurements of the axial displacement and evolving size of optically trapped aerosol droplets

    Science.gov (United States)

    Knox, K. J.; Reid, J. P.; Hanford, K. L.; Hudson, A. J.; Mitchem, L.

    2007-08-01

    The axial displacement of optically tweezed liquid aerosol droplets has been studied directly through the application of side imaging at 90° to the trapping laser beam. In conjunction with imaging in the plane of the optical trap and cavity-enhanced Raman spectroscopy (CERS), the optical forces experienced by a trapped aerosol have been interrogated. By varying the power of the trapping laser and observing changes in the axial position of a trapped particle it has been possible to examine the fine balance between the gradient and scattering forces, a key parameter in optical manipulation. Clear differences observed in sizing trapped particles from bright field microscopy and CERS have been reconciled. As a consequence, a novel technique for probing the evolving size of a single aerosol particle is proposed.

  6. Size measurement of gold and silver nanostructures based on their extinction spectrum: limitations and extensions

    Directory of Open Access Journals (Sweden)

    A A Ashkarran

    2013-09-01

    Full Text Available  This paper reports on physical principles and the relations between extinction cross section and geometrical properties of silver and gold nanostructures. We introduce some simple relations for determining geometrical properties of silver and gold nanospheres based on the situation of their plasmonic peak. We also applied, investigated and compared the accuracy of these relations using other published works in order to make clear the effects of shape, size distribution and refractive index of particles’ embedding medium. Finally, we extended the equations to non-spherical particles and investigated their accuracy. We found that modified forms of the equations may lead to more exact results for non-spherical metal particles, but for better results, modified equations should depend on shape and size distribution of particles. It seems that these equations are not applicable to particles with corners sharper than cubes' corners i.e. nanostructures with spatial angles less than π/2 sr.

  7. Cell Size Discrimination Based on the Measurement of the Equilibrium Velocity in Rectangular Microchannels

    Directory of Open Access Journals (Sweden)

    Lisa Schott

    2015-05-01

    Full Text Available Flow cytometry is a well-established diagnostic tool for cell counting and characterization. It utilizes fluorescence and scattered excitation light simultaneously emitted from cells passing an excitation laser focus to discriminate various cell types and estimate cell size. Here, we apply the principle of spatially modulated emission (SME to fluorescently stained SUP-B15 cells as a model system for cancer cells and Marinococcus luteus as model for bacteria. We demonstrate that the experimental apparatus is able to detect these model cells and that the results are comparable to those obtained by a commercially available CASY® TT Counter. Furthermore, by examining the velocity distribution of the cells, we observe clear relationships between cell condition/size and cell velocity. Thus, the cell velocity provides information comparable to the scatter signal in conventional flow cytometry. These results indicate that the SME technique is a promising method for simultaneous cell counting and viability characterization.

  8. Stem Hydraulic Conductivity depends on the Pressure at Which It Is Measured and How This Dependence Can Be Used to Assess the Tempo of Bubble Pressurization in Recently Cavitated Vessels1[OPEN

    Science.gov (United States)

    Liu, Jinyu; Tyree, Melvin T.

    2015-01-01

    Cavitation of water in xylem vessels followed by embolism formation has been authenticated for more than 40 years. Embolism formation involves the gradual buildup of bubble pressure (air) to atmospheric pressure as demanded by Henry’s law of equilibrium between gaseous and liquid phases. However, the tempo of pressure increase has not been quantified. In this report, we show that the rate of pressurization of embolized vessels is controlled by both fast and slow kinetics, where both tempos are controlled by diffusion but over different spatial scales. The fast tempo involves a localized diffusion from endogenous sources: over a distance of about 0.05 mm from water-filled wood to the nearest embolized vessels; this process, in theory, should take measurements both confirm that the average time constant is >17 h, with complete equilibrium requiring 1 to 2 d. The implications of these timescales for the standard methods of measuring percentage loss of hydraulic conductivity are discussed in theory and deserve more research in future. PMID:26468516

  9. Stem Hydraulic Conductivity depends on the Pressure at Which It Is Measured and How This Dependence Can Be Used to Assess the Tempo of Bubble Pressurization in Recently Cavitated Vessels.

    Science.gov (United States)

    Wang, Yujie; Liu, Jinyu; Tyree, Melvin T

    2015-12-01

    Cavitation of water in xylem vessels followed by embolism formation has been authenticated for more than 40 years. Embolism formation involves the gradual buildup of bubble pressure (air) to atmospheric pressure as demanded by Henry's law of equilibrium between gaseous and liquid phases. However, the tempo of pressure increase has not been quantified. In this report, we show that the rate of pressurization of embolized vessels is controlled by both fast and slow kinetics, where both tempos are controlled by diffusion but over different spatial scales. The fast tempo involves a localized diffusion from endogenous sources: over a distance of about 0.05 mm from water-filled wood to the nearest embolized vessels; this process, in theory, should take measurements both confirm that the average time constant is >17 h, with complete equilibrium requiring 1 to 2 d. The implications of these timescales for the standard methods of measuring percentage loss of hydraulic conductivity are discussed in theory and deserve more research in future. © 2015 American Society of Plant Biologists. All Rights Reserved.

  10. Single-shot betatron source size measurement from a laser-wakefield accelerator

    CERN Document Server

    Köhler, A.; Zarini, O.; Jochmann, A.; Irman, A.; Schramm, U.; 10.1016/j.nima.2016.02.031

    2016-01-01

    Betatron radiation emitted by accelerated electrons in laser-wakefield accelerators can be used as a diagnostic tool to investigate electron dynamics during the acceleration process. We analyze the spectral characteristics of the emitted Betatron pattern utilizing a 2D x-ray imaging spectroscopy technique. Together with simultaneously recorded electron spectra and x-ray images, the betatron source size, thus the electron beam radius, can be deduced at every shot.

  11. Measurement of an electronic cigarette aerosol size distribution during a puff

    OpenAIRE

    Belka Miloslav; Lizal Frantisek; Jedelsky Jan; Jicha Miroslav; Pospisil Jiri

    2017-01-01

    Electronic cigarettes (e-cigarettes) have become very popular recently because they are marketed as a healthier alternative to tobacco smoking and as a useful tool to smoking cessation. E-cigarettes use a heating element to create an aerosol from a solution usually consisting of propylene glycol, glycerol, and nicotine. Despite the wide spread of e-cigarettes, information about aerosol size distributions is rather sparse. This can be caused by the relative newness of e-cigarettes and by the d...

  12. Single-shot betatron source size measurement from a laser-wakefield accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Koehler, Alexander; Couperus, Jurjen; Zarini, Omid; Schramm, Ulrich [Helmholtz-Zentrum Dresden-Rossendorf, Dresden (Germany); Technische Universitaet Dresden (Germany); Jochmann, Axel; Irman, Arie [Helmholtz-Zentrum Dresden-Rossendorf, Dresden (Germany)

    2016-07-01

    Betatron radiation emitted by accelerated electrons in laser-wakefield accelerators can be used as a diagnostic tool to investigate electron dynamics during the acceleration process. We analyse the spectral characteristics of the emitted betatron pattern utilizing a 2D X-ray imaging spectroscopy technique. Together with simultaneously recorded electron spectra and X-ray images, the betatron source size, thus the electron beam radius, can be deduced at every shot.

  13. Size-dependent Measurements of the Scattering Properties of Planetary Regolith Analogs: A Challenge to Theory

    Science.gov (United States)

    Piatek, J. L.; Hapke, B. W.; Nelson, R. M.; Hale, A. S.; Smythe, W. D.

    2003-01-01

    The nature of the scattering of light is thought to be well understood when the medium is made up of independent scatterers that are much larger than the wavelength of that light. This is not the case when the size of the scattering objects is similar to or smaller than the wavelength or the scatterers are not independent. In an attempt to examine the applicability of independent particle scattering models, to planetary regoliths, a dataset of experimental results were compared with theoretical predictions.

  14. Quantitative measurement of biological substances in daily-life environment with the little-finger-size one-shot spectroscopic tomography

    Science.gov (United States)

    Ishida, Akane; Sato, Shun; Nakada, Sho; Suzuki, Satoru; Abeygunawardhana, P. K. W.; Wada, Kenji; Nishiyama, Akira; Ishimaru, Ichiro

    2014-02-01

    In daily-life environment, the quantitative measurement of biological substances, such as the blood glucose level in the human skin, is strongly required to realize the non-invasive healthcare apparatus. Fourier-spectroscopic-tomography of the little-finger-size with high time-resolution and with the strong robustness for mechanical vibrations is proposed. The proposed method is a kind of near-common-path interferometer with spatial phase-shift method. We install the transmission-type relative-inclined phase-shifter on the optical Fourier transform plane of the infinity corrected optical system. The phase shifter is constructed with the cuboid and wedge prisms to give the relative phase-shift spatially between each half-flux of the objective beams. The interferograms from each single-bright-point on an objective surface in a line are formed as fringe patterns on 2-dimensional imaging array devices. And because the proposed method is based on the imaging optics, only emitted rays from a focal plane can contribute forming of interferograms. Thus, the measurement plane can be limited onto the focal plane only. From the spectroscopic tomography, only at a localized vessel area in human skins, we can get the pinpointed near-infrared spectroscopic data. And we can expect the improvement of the determination precision, because a Fourier spectroscopic-character is acquired from multiple intensity data in accordance with amount of phase-shift. From the statistical point of view, the gradation of detector is improved with the square root of sample number, based on t-distribution. We constructed the statistical model to assure the determination accuracy, and demonstrated the feasibility of the glucose sensor using liquid cells.

  15. Measuring the Impact of Femoral Head Size on Dislocation Rates Following Total Hip Arthroplasty

    Science.gov (United States)

    Kim, Min-Wook; Lee, Ji-Won; Kim, Chel-Hwan

    2017-01-01

    Purpose The purpose of this study was to evaluate if the femoral head's size has an impact on dislocation rates following total hip arthroplasty (THA). Materials and Methods Five hundreds forty-three THA performed using a posterolateral approach in our hospital and followed up more than 6 months were included in this study. We evaluated dislocation rates based on the size of femoral head (28 mm vs. over 32 mm) and further investigated the dislocation rates classified into primary and revision surgery. Patient-related and surgical factors were reviewed to evaluate risk factors impacting dislocation rates. Results Dislocation occurred in 9.6% of cases (n=52; 32 males and 20 females). Of this dislocation group, 36 were treated with femoral heads 28 mm in diameter (9.8% of all patients treated with 28 mm femoral heads) and 16 were treated with femoral heads 32 mm and over (9.1% of all patients treated with femoral heads of at least 32 mm). The percentages of patients experiencing dislocation were not significantly different among the two groups (i.e., 28 mm vs. ≥32 mm). However, after revision surgery, the dislocation rate in the 28-mm group was significantly higher than the ≥32-mm group (Pdislocation and non-dislocation groups, the risk of dislocation was 6 times higher in patients with habitual alcohol intake, and 9.2 times higher in patients with a neuropsychiatric disorder (Pdislocation rates following THA than the size of femoral head. PMID:28611959

  16. Scaling in Free-Swimming Fish and Implications for Measuring Size-at-Time in the Wild

    Science.gov (United States)

    Broell, Franziska; Taggart, Christopher T.

    2015-01-01

    This study was motivated by the need to measure size-at-age, and thus growth rate, in fish in the wild. We postulated that this could be achieved using accelerometer tags based first on early isometric scaling models that hypothesize that similar animals should move at the same speed with a stroke frequency that scales with length-1, and second on observations that the speed of primarily air-breathing free-swimming animals, presumably swimming ‘efficiently’, is independent of size, confirming that stroke frequency scales as length-1. However, such scaling relations between size and swimming parameters for fish remain mostly theoretical. Based on free-swimming saithe and sturgeon tagged with accelerometers, we introduce a species-specific scaling relationship between dominant tail beat frequency (TBF) and fork length. Dominant TBF was proportional to length-1 (r2 = 0.73, n = 40), and estimated swimming speed within species was independent of length. Similar scaling relations accrued in relation to body mass-0.29. We demonstrate that the dominant TBF can be used to estimate size-at-time and that accelerometer tags with onboard processing may be able to provide size-at-time estimates among free-swimming fish and thus the estimation of growth rate (change in size-at-time) in the wild. PMID:26673777

  17. Linking snow depth to avalanche release area size: measurements from the Vallée de la Sionne field site

    Science.gov (United States)

    Veitinger, Jochen; Sovilla, Betty

    2016-08-01

    One of the major challenges in avalanche hazard assessment is the correct estimation of avalanche release area size, which is of crucial importance to evaluate the potential danger that avalanches pose to roads, railways or infrastructure. Terrain analysis plays an important role in assessing the potential size of avalanche releases areas and is commonly based on digital terrain models (DTMs) of a snow-free summer terrain. However, a snow-covered winter terrain can significantly differ from its underlying, snow-free terrain. This may lead to different, and/or potentially larger release areas. To investigate this hypothesis, the relation between avalanche release area size, snow depth and surface roughness was investigated using avalanche observations of artificially triggered slab avalanches over a period of 15 years in a high-alpine field site. High-resolution, continuous snow depth measurements at times of avalanche release showed a decrease of mean surface roughness with increasing release area size, both for the bed surface and the snow surface before avalanche release. Further, surface roughness patterns in snow-covered winter terrain appeared to be well suited to demarcate release areas, suggesting an increase of potential release area size with greater snow depth. In this context, snow depth around terrain features that serve as potential delineation borders, such as ridges or trenches, appeared to be particularly relevant for release area size. Furthermore, snow depth measured at a nearby weather station was, to a considerable extent, related to potential release area size, as it was often representative of snow depth around those critical features where snow can accumulate over a long period before becoming susceptible to avalanche release. Snow depth - due to its link to surface roughness - could therefore serve as a highly useful variable with regard to potential release area definition for varying snow cover scenarios, as, for example, the avalanche

  18. Real-Time Measurement of Electronic Cigarette Aerosol Size Distribution and Metals Content Analysis.

    Science.gov (United States)

    Mikheev, Vladimir B; Brinkman, Marielle C; Granville, Courtney A; Gordon, Sydney M; Clark, Pamela I

    2016-09-01

    Electronic cigarette (e-cigarette) use is increasing worldwide and is highest among both daily and nondaily smokers. E-cigarettes are perceived as a healthier alternative to combustible tobacco products, but their health risk factors have not yet been established, and one of them is lack of data on aerosol size generated by e-cigarettes. We applied a real-time, high-resolution aerosol differential mobility spectrometer to monitor the evolution of aerosol size and concentration during puff development. Particles generated by e-cigarettes were immediately delivered for analysis with minimal dilution and therefore with minimal sample distortion, which is critically important given the highly dynamic aerosol/vapor mixture inherent to e-cigarette emissions. E-cigarette aerosols normally exhibit a bimodal particle size distribution: nanoparticles (11-25nm count median diameter) and submicron particles (96-175nm count median diameter). Each mode has comparable number concentrations (10(7)-10(8) particles/cm(3)). "Dry puff" tests conducted with no e-cigarette liquid (e-liquid) present in the e-cigarette tank demonstrated that under these conditions only nanoparticles were generated. Analysis of the bulk aerosol collected on the filter showed that e-cigarette emissions contained a variety of metals. E-cigarette aerosol size distribution is different from that of combustible tobacco smoke. E-cigarettes generate high concentrations of nanoparticles and their chemical content requires further investigation. Despite the small mass of nanoparticles, their toxicological impact could be significant. Toxic chemicals that are attached to the small nanoparticles may have greater adverse health effects than when attached to larger submicron particles. The e-cigarette aerosol size distribution is different from that of combustible tobacco smoke and typically exhibits a bimodal behavior with comparable number concentrations of nanoparticles and submicron particles. While vaping the e

  19. A measurement model for real estate bubble size based on the panel data analysis: An empirical case study

    OpenAIRE

    Liu, Fengyun; Liu, Deqiang; Malekian, Reza; Li, Zhixiong; Wang, Deqing

    2017-01-01

    Employing the fundamental value of real estate determined by the economic fundamentals, a measurement model for real estate bubble size is established based on the panel data analysis. Using this model, real estate bubble sizes in various regions in Japan in the late 1980s and in recent China are examined. Two panel models for Japan provide results, which are consistent with the reality in the 1980s where a commercial land price bubble appeared in most area and was much larger than that of re...

  20. Measurements of Pulmonary Artery Size for Assessment of Pulmonary Hypertension by Cardiovascular Magnetic Resonance and Clinical Application

    Directory of Open Access Journals (Sweden)

    Fan YANG

    2017-02-01

    Full Text Available Background and objective Pulmonary hypertension (PH often leads to dilatation of main pulmonary artery (MPA. MPA measurements can be used to predict PH. This aim of this study is to investigate power of MPA vessel indices, which are acquired from cardiovascular magnetic resonance, to evaluate PH. Methods Cardiovascular-magnetic-resonance-determined parameters of MPA were acquired and calculated in 83 PH patients, whose diagnosis were confirmed with right heart catheterization and 49 healthy volunteers; these parameters included MPA diameter (DPA, ratio of DPA and ascending aorta diameter (DPA/DAo, max mean diameter (MDmax, min mean diameter (MDmin, fraction transverse diameter (fTD, fraction longitudinal diameter (fLD, and distensibility. Results Compared with control group, DPA, DPA/DAo, MDmax, and MDmin were significantly higher in patients with PH (P28.4 mm, and MDmax>32.4 mm (area under the curve, AUC=0.979, 0.981 showed best performance in predicting PH, yielding highest specificity at 100%. Conclusion Noninvasive cardiovascular-magnetic-resonance-derived MPA measurements provide excellent and practical reference in clinical settings for detecting PH.

  1. Particle Size Measurements from the first Fundamentals of Ice Crystal Icing Physics Test in the NASA Propulsion Systems Laboratory

    Science.gov (United States)

    King, Michael C.; Bachalo, William; Kurek, Andrzej

    2017-01-01

    This presentation shows particle measurements by the Artium Technologies, Inc. Phase Doppler Interferometer and High Speed Imaging instruments from the first Fundamental Ice Crystal Icing Physics test conducted in the NASA Propulsion Systems Laboratory. The work focuses on humidity sweeps at a larger and a smaller median volumetric diameter. The particle size distribution, number density, and water content measured by the Phase Doppler Interferometer and High Speed Imaging instruments from the sweeps are presented and compared. The current capability for these two instruments to measure and discriminate ICI conditions is examined.

  2. Why SMEs invest in Environmental Measures: Sustainability Evidence from Small and Medium-sized Printing Firms

    NARCIS (Netherlands)

    Masurel, E.

    2007-01-01

    Why do SMEs invest in environmental measures? From the literature we know that most SMEs are rather slow in adopting these sustainable measures, but then the following question arises: why are other SMEs fast in this respect? From our research, it becomes clear that improving the working conditions

  3. Size distribution of retrovirally marked lineages matches prediction from population measurements of cell cycle behavior

    Science.gov (United States)

    Cai, Li; Hayes, Nancy L.; Takahashi, Takao; Caviness, Verne S Jr; Nowakowski, Richard S.

    2002-01-01

    Mechanisms that regulate neuron production in the developing mouse neocortex were examined by using a retroviral lineage marking method to determine the sizes of the lineages remaining in the proliferating population of the ventricular zone during the period of neuron production. The distribution of clade sizes obtained experimentally in four different injection-survival paradigms (E11-E13, E11-E14, E11-E15, and E12-E15) from a total of over 500 labeled lineages was compared with that obtained from three models in which the average behavior of the proliferating population [i.e., the proportion of cells remaining in the proliferative population (P) vs. that exiting the proliferative population (Q)] was quantitatively related to lineage size distribution. In model 1, different proportions of asymmetric, symmetric terminal, and symmetric nonterminal cell divisions coexisted during the entire developmental period. In model 2, the developmental period was divided into two epochs: During the first, asymmetric and symmetric nonterminal cell divisions occurred, but, during the second, asymmetric and symmetric terminal cell divisions occurred. In model 3, the shifts in P and Q are accounted for by changes in the proportions of the two types of symmetric cell divisions without the inclusion of any asymmetric cell divisions. The results obtained from the retroviral experiments were well accounted for by model 1 but not by model 2 or 3. These findings demonstrate that: 1) asymmetric and both types of symmetric cell divisions coexist during the entire period of neurogenesis in the mouse, 2) neuron production is regulated in the proliferative population by the independent decisions of the two daughter cells to reenter S phase, and 3) neurons are produced by both asymmetric and symmetric terminal cell divisions. In addition, the findings mean that cell death and/or tangential movements of cells in the proliferative population occur at only a low rate and that there are no

  4. Comparing radio-tracking and visual detection methods to quantify group size measures

    Directory of Open Access Journals (Sweden)

    Reiczigel Jenő

    2015-12-01

    Full Text Available 1. Average values of animal group sizes are prone to be overestimated in traditional field studies because small groups and singletons are easier to overlook than large ones. This kind of bias also applies for the method of locating groups by tracking previously radio-collared individuals in the wild. If the researcher randomly chooses a collared animal to locate a group to visit, a large group has higher probability to be selected than a small one, simply because it has more members.

  5. Size specific indoor aerosol deposition measurements and derived I/O concentrations ratios

    DEFF Research Database (Denmark)

    Fogh, C.L.; Byrne, M.A.; Roed, Jørn

    1997-01-01

    passage of a radioactive aerosol cloud. To examine the general validity of this figure, indoor aerosol deposition have been determined in four houses. Monodisperse aerosol particles, with mass median aerodynamic diameters (MMAD) in the range 0.5-5.5 mu m, were labelled with neutron-activatable tracers......, the following empirical expression, relating the particles' MMAD (d(p), in mu m) to the indoor deposition velocity (upsilon(d), in 10(-4) m s(-1)) was derived: upsilon(d) = 0.48 + 0.60 d(p) (r = 0.93). Using this formula, particle size-specific DRFs were determined and found to be in good agreement...

  6. The effects of particle size on measurement of airway hyperresponsiveness to methacholine.

    Science.gov (United States)

    Naji, Nizar; Keung, Elaine; Beaudin, Suzanne; Kane, James; Killian, Kieran J; Gauvreau, Gail M

    2013-05-01

    The effect of particle size on methacholine provocation concentration causing a decrease in forced expiratory volume of 1 second (FEV1) of 20% (PC20) is debatable. To evaluate the functional effects of 3 different particle size nebulizers on methacholine PC20. Participants were randomly assigned to have 3 methacholine challenges on 3 separate days. Nebulizer mass median aerodynamic diameter (MMAD) was provided by manufacturers. The Wright nebulizer (MMAD, 1.0 μm), Aeroneb (MMAD, 3 μm), and Aeroneb (MMAD, 5 μm) were calibrated, and the nebulizer outputs were calculated to administer 0.26 mL of methacholine over 120, 112, and 83 seconds, respectively. After each inhalation, spirometry was performed and the test was terminated when the PC20 was achieved. Eight nonsmoking patients with mild asthma (4 male and 4 female) completed the study. The mean (SD) age was 25 (13.9) years, and the mean (SD) baseline FEV1 was 88% (11.3%). Patients using the Aeroneb (MMAD, 5 μm) nebulizer had the lowest PC20 (bronchoconstricted at lowest methacholine concentration), with a PC20 geometric mean of 0.62 mg/mL compared with patients using the Aeroneb (MMAD, 3.0 μm), who had a PC20 of 1.76 mg/mL, and patients using the Wright nebulizer (MMAD, 1.0 μm), who had a PC20 of 6.32 mg/mL. There was a significant difference in PC20 across all particle sizes (P < .001). The pairwise differences revealed a P < .001 between 3 μm and 1 μm and between 5 μm and 1 μm and a P = .008 between 5 μm and 3 μm. Our results reveal a variability in methacholine PC20 using 3 different nebulizers, despite adjusting the nebulizers' outputs. Our results are consistent with the previous reports, which recommended using larger particle size nebulizers in the assessment of airway hyperresponsiveness in asthma. clinicaltrials.gov Identifier: NCT00529477. Copyright © 2013 American College of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

  7. Effect of feed processing on size of (washed) faeces particles from pigs measured by image analysis

    DEFF Research Database (Denmark)

    Nørgaard, Peder; Kornfelt, Louise Foged; Hansen, Christian Fink

    2005-01-01

    of particles from the sieving fractions were scanned and the length and width of individual particles were identified using image analysis software. The overall mean, mode and median were estimated from a composite function. The dietary physical characteristics significantly affected the proportion of faecal......Our aim was to study the effect of dietary physical characteristics on size of washed faecal particles from finishing pigs (98±6 kg). The pigs were fed either a finely ground pelleted diet (FP) or a coarsely ground meal diet (CM) comparable in all ingredients. The diets were based on barley, wheat...

  8. Rapid infrared laser sealing and cutting of porcine renal vessels, ex vivo

    Science.gov (United States)

    Giglio, Nicholas C.; Hutchens, Thomas C.; Perkins, William C.; Latimer, Cassandra; Ward, Arlen; Nau, William H.; Fried, Nathaniel M.

    2014-03-01

    Suture ligation with subsequent cutting of blood vessels to maintain hemostasis during surgery is time consuming and skill intensive. Energy-based, electrosurgical and ultrasonic devices are often used to replace sutures and mechanical clips to provide rapid hemostasis, and decrease surgical time. Some of these devices may create undesirably large collateral zones of thermal damage and tissue necrosis, or require separate mechanical blades for cutting. Infrared lasers are currently being explored as alternative energy sources for vessel sealing applications. In a previous study, a 1470-nm laser was used to seal vessels of 1-6 mm in diameter in 5 s, yielding burst pressures of ~ 500 mmHg. The purpose of this study was to provide faster sealing, incorporate transection of the sealed vessels, and increase the burst pressure. A 110-Watt, 1470-nm laser beam was transmitted through a fiber and beam shaping optics, producing a linear beam 3.0 mm by 9.5 mm for sealing, and 1.1 mm by 9.6 mm for cutting (FWHM). A twostep process sealed then transected ex vivo porcine renal vessels (1-8.5 mm diameter) in a bench top setup. Seal and cut times were 1.0 s each. A standard burst pressure system measured resulting seal strength, and gross and histologic thermal damage measurements were also recorded. All blood vessels tested (n = 30) were sealed and cut, with total irradiation times of 2.0 s, mean burst pressures > 1000 mmHg (compared to normal systolic blood pressure of 120 mmHg), and combined seal/collateral thermal coagulation zones of 2-3 mm. The results of this study demonstrated that an optical-based system is capable of precisely sealing and cutting a wide range of porcine renal vessel sizes, and with further development, may provide an alternative to radiofrequency and ultrasound-based vessel sealing devices.

  9. Methods to measure NLR oligomerization: size exclusion chromatography, co-immunoprecipitation and cross-linking

    Science.gov (United States)

    Khare, Sonal; Radian, Alexander D.; Dorfleutner, Andrea; Stehlik, Christian

    2016-01-01

    Summary Oligomerization of NLRs can be detected by several biochemical techniques dependent on the stringency of protein-protein interactions. Some of these biochemical methods can be combined with functional assays, such as caspase-1 activity assay. Size exclusion chromatography (SEC) allows separation of native protein lysates into different sized complexes by FPLC for follow-up analysis. Using co-immunoprecipitation (co-IP), combined with SEC or on its own, enables subsequent antibody-based purification of NLR complexes and associated proteins, which can then be analyzed by immunoblot and/or subjected to functional caspase-1 activity assay. Chemical crosslinking covalently joins two or more molecules, thus capturing the oligomeric state with high sensitivity and stability. ASC oligomerization has been successfully used as readout for NLR/ALR inflammasome activation in response to various PAMPs and DAMPs in human and mouse macrophages and THP-1 cells. Here we provide a detailed description of the methods used for NLRP7 oligomerization in response to infection with Stapylococcus aureus (S.aureus) in primary human macrophages, co-immunoprecipitation and immunoblot analysis of NLRP7 and NLRP3 inflammasome complexes as well as caspase-1 activity assays. Also, ASC oligomerization is shown in response to dsDNA, LPS/ATP and LPS/nigericin in mouse bone marrow derived macrophages (BMDMs) and/or THP-1 cells or human primary macrophages. PMID:27221486

  10. Effect size measures in a two-independent-samples case with nonnormal and nonhomogeneous data.

    Science.gov (United States)

    Li, Johnson Ching-Hong

    2016-12-01

    In psychological science, the "new statistics" refer to the new statistical practices that focus on effect size (ES) evaluation instead of conventional null-hypothesis significance testing (Cumming, Psychological Science, 25, 7-29, 2014). In a two-independent-samples scenario, Cohen's (1988) standardized mean difference (d) is the most popular ES, but its accuracy relies on two assumptions: normality and homogeneity of variances. Five other ESs-the unscaled robust d (d r* ; Hogarty & Kromrey, 2001), scaled robust d (d r ; Algina, Keselman, & Penfield, Psychological Methods, 10, 317-328, 2005), point-biserial correlation (r pb ; McGrath & Meyer, Psychological Methods, 11, 386-401, 2006), common-language ES (CL; Cliff, Psychological Bulletin, 114, 494-509, 1993), and nonparametric estimator for CL (A w ; Ruscio, Psychological Methods, 13, 19-30, 2008)-may be robust to violations of these assumptions, but no study has systematically evaluated their performance. Thus, in this simulation study the performance of these six ESs was examined across five factors: data distribution, sample, base rate, variance ratio, and sample size. The results showed that A w and d r were generally robust to these violations, and A w slightly outperformed d r . Implications for the use of A w and d r in real-world research are discussed.

  11. Time-resolved Tomographic PIV Measurements of Water Flea Hopping: Body Size Comparison

    Science.gov (United States)

    Skipper, A. N.; Murphy, D. W.; Webster, D. R.; Yen, J.

    2014-11-01

    The flow field of the freshwater crustacean Daphnia magna is quantified with time-resolved tomographic PIV. In the current work, we compare body kinematics and flow disturbance between organisms of small (body length = 1.8 mm) versus medium (2.3 mm) versus large (2.65 mm) size. These plankters are equipped with a pair of antennae that are biramous such that the protopodite splits or branches into an exopodite and an endopodite. They beat the antennae pair synchronously to impulsively propel themselves, or `hop,' through the water. The stroke cycle of Daphnia magna is roughly 80 ms in duration and this period is evenly split between the power and recovery strokes. A typical hop carries the daphniid one body length forward and is followed by a period of sinking. Unlike copepod escape motion, no body vortex is observed in front of the animal. Rather, the flow induced by each antennae consists of a viscous vortex ring that demonstrates a slow decay. The time-record of velocity (peak of 40 mm/s for the medium specimen) and hop acceleration (1.8 m/s2 for the medium specimen) are compared, as well as the strength, size, and decay of the induced viscous vortex rings. The viscous vortex ring analysis will be presented in the context of a double Stokeslet model consisting of two impulsively applied point forces separated by the animal width.

  12. On-chip light sheet illumination enables diagnostic size and concentration measurements of membrane vesicles in biofluids

    Science.gov (United States)

    Deschout, Hendrik; Raemdonck, Koen; Stremersch, Stephan; Maoddi, Pietro; Mernier, Guillaume; Renaud, Philippe; Jiguet, Sébastien; Hendrix, An; Bracke, Marc; van den Broecke, Rudy; Röding, Magnus; Rudemo, Mats; Demeester, Jo; de Smedt, Stefaan C.; Strubbe, Filip; Neyts, Kristiaan; Braeckmans, Kevin

    2014-01-01

    Cell-derived membrane vesicles that are released in biofluids, like blood or saliva, are emerging as potential non-invasive biomarkers for diseases, such as cancer. Techniques capable of measuring the size and concentration of membrane vesicles directly in biofluids are urgently needed. Fluorescence single particle tracking microscopy has the potential of doing exactly that by labelling the membrane vesicles with a fluorescent label and analysing their Brownian motion in the biofluid. However, an unbound dye in the biofluid can cause high background intensity that strongly biases the fluorescence single particle tracking size and concentration measurements. While such background intensity can be avoided with light sheet illumination, current set-ups require specialty sample holders that are not compatible with high-throughput diagnostics. Here, a microfluidic chip with integrated light sheet illumination is reported, and accurate fluorescence single particle tracking size and concentration measurements of membrane vesicles in cell culture medium and in interstitial fluid collected from primary human breast tumours are demonstrated.Cell-derived membrane vesicles that are released in biofluids, like blood or saliva, are emerging as potential non-invasive biomarkers for diseases, such as cancer. Techniques capable of measuring the size and concentration of membrane vesicles directly in biofluids are urgently needed. Fluorescence single particle tracking microscopy has the potential of doing exactly that by labelling the membrane vesicles with a fluorescent label and analysing their Brownian motion in the biofluid. However, an unbound dye in the biofluid can cause high background intensity that strongly biases the fluorescence single particle tracking size and concentration measurements. While such background intensity can be avoided with light sheet illumination, current set-ups require specialty sample holders that are not compatible with high-throughput diagnostics

  13. Effect of Single Administration of Coffee on Pupil Size and Ocular Wavefront Aberration Measurements in Healthy Subjects

    Directory of Open Access Journals (Sweden)

    Handan Bardak

    2016-01-01

    Full Text Available No study has so far evaluated the impact of coffee drinking on ocular wavefront aberration (OWA measurements. This study presents novel findings regarding the OWA of the eye following coffee intake. We aimed to evaluate the acute changes in pupil size and OWA of the eye after single administration of coffee. A total of 30 otherwise healthy participants were included in this prospective study. All subjects drank a cup of coffee containing 57 mg caffeine. Measurements of pupil size, total coma (TC, total trefoil (TF, total spherical aberration (TSA, and total higher order aberration (HOA were performed before and at 5 minutes, at 30 minutes, and at 4 hours after coffee drinking using a wavefront aberrometer device (Irx3, Imagine Eyes, Orsay, France. The mean age of the study population was 20.30 ± 2.74 years. Pupil size did not show a significant change during the measurements (p>0.05. A significant increase was observed in TF and HOA measurements following coffee intake (p=0.029 and p=0.009, resp.. Single administration of coffee results in significant increase in TF and total HOAs in healthy subjects without any effect on pupil diameter. Ultrastructural changes in the cornea following coffee intake might be of relevance to the alterations in ocular aberrations in healthy subjects.

  14. Computer-based assessments of expected satiety predict behavioural measures of portion-size selection and food intake.

    Science.gov (United States)

    Wilkinson, Laura L; Hinton, Elanor C; Fay, Stephanie H; Ferriday, Danielle; Rogers, Peter J; Brunstrom, Jeffrey M

    2012-12-01

    Previously, expected satiety (ES) has been measured using software and two-dimensional pictures presented on a computer screen. In this context, ES is an excellent predictor of self-selected portions, when quantified using similar images and similar software. In the present study we sought to establish the veracity of ES as a predictor of behaviours associated with real foods. Participants (N=30) used computer software to assess their ES and ideal portion of three familiar foods. A real bowl of one food (pasta and sauce) was then presented and participants self-selected an ideal portion size. They then consumed the portion ad libitum. Additional measures of appetite, expected and actual liking, novelty, and reward, were also taken. Importantly, our screen-based measures of expected satiety and ideal portion size were both significantly related to intake (p.05). In addition, consistent with previous studies, the majority (90%) of participants engaged in plate cleaning. Of these, 29.6% consumed more when prompted by the experimenter. Together, these findings further validate the use of screen-based measures to explore determinants of portion-size selection and energy intake in humans. Copyright © 2012 Elsevier Ltd. All rights reserved.

  15. Size Resolved measurements of aerosol hygroscopicity and mixing state during Green Ocean Amazon (GoAmazon) 2014

    Science.gov (United States)

    Thalman, R. M.; Artaxo, P.; Campuzano Jost, P.; Barbosa, H. M.; Day, D. A.; de Sá, S. S.; Hu, W.; Jimenez, J. L.; Kuang, C.; Palm, B. B.; Krüger, M. L.; Manzi, A. O.; Martin, S. T.; Poeschl, U.; Sedlacek, A. J., III; Senum, G.; Souza, R. A. F. D.; Springston, S. R.; Alexander, M. L.; Watson, T. B.; Wang, J.

    2014-12-01

    Measurements of size-resolved cloud condensation nucleai (CCN) spectra were performed at the T3 site of the Green Ocean Amazon (GoAmazon) field project located near Manacapuru, Brazil during 2014. The T3 site is a receptor site for both polluted urban down-wind (Manaus, BR a city of several million 70 km up wind) and background (Amazon rainforest) air-masses and can provide a contrast between clean and polluted conditions. Particle hygroscopicity (kappa) and mixing state were calculated from the particle activation spectrum measured by size selecting aerosols and exposing them to a wide range of supersaturation in the CCN counter (Droplet Measurement Technologies Continuous-Flow Streamwise Thermal Gradient CCN Chamber). The supersaturation was varied between 0.07 and 1.1% by changing a combination of both total flow rate and temperature gradient in the CCN counter. Measured spectra were examined for air masses with different level of influence from Manaus plume. Particle hygroscopicity generally peaked near noon local time which was broadly consistent with the trend in aerosol sulfate. The average kappa values during the first intensive operation period were 0.14±0.05, 0.14±0.04 and 0.16±0.06 for 75, 112 and 171 nm particles respectively. Evaluation of particle hygroscopicity and dispersion (mixing state) will be presented with respect to size and level of pollution.

  16. Intra- and inter-tester reliability and validity of normal finger size measurement using the Japanese ring gauge system.

    Science.gov (United States)

    Suzuki, T; Sato, Y; Sotome, S; Arai, H; Arai, A; Yoshida, H

    2017-06-01

    This study was designed to investigate the reliability and validity of measurements of finger diameters with a ring gauge. A reliability study enrolled two independent samples (50 participants and seven examiners in Study I; 26 participants and 26 examiners in Study II). The sizes of each participant's little fingers were measured twice with a ring gauge by each examiner. To investigate the validity of the measurements, five hand therapists compared the finger size and hand volume of 30 participants with the ring gauge and with a figure-of-eight technique (Study III). The intra-class correlation coefficient for intra-observer reliability ranged from 0.97 to 0.99 in Study I, and 0.90 to 0.97 in Study II. The intra-class correlation coefficient for inter-observer reliability was 0.95 in Study I and 0.94 in Study II. The validity study showed a Pearson product moment correlation coefficient of 0.75. The ring gauge showed high reliability and validity for measurement of finger size. III, diagnostic.

  17. Calibration-free device sizing using an inverse geometry x-ray system

    Energy Technology Data Exchange (ETDEWEB)

    Tomkowiak, Michael T.; Speidel, Michael A.; Raval, Amish N.; Van Lysel, Michael S. [Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53705 (United States); Department of Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin 53705 (United States); Department of Medicine, University of Wisconsin-Madison, Madison, Wisconsin 53792 (United States); Department of Medicine and Department Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin 53792 (United States)

    2011-01-15

    Purpose: Quantitative coronary angiography (QCA) can be used to support device size selection for cardiovascular interventions. The accuracy of QCA measurements using conventional x-ray fluoroscopy depends on proper calibration using a reference object and avoiding vessel foreshortening. The authors have developed a novel interventional device sizing method using the inverse geometry scanning-beam digital x-ray (SBDX) fluoroscopy system. The proposed method can measure the diameter and length of vessel segments without imaging a reference object and when vessels appear foreshortened. Methods: SBDX creates multiple tomosynthetic x-ray images corresponding to planes through the patient volume. The structures that lie in the plane are in focus and the features above and below the plane are blurred. Three-dimensional localization of the vessel edges was performed by examining the degree of blurring at each image plane. A 3D vessel centerline was created and used to determine vessel magnification and angulation relative to the image planes. Diameter measurements were performed using a model-based method and length measurements were calculated from the 3D centerline. Phantom validation was performed by measuring the diameter and length of vessel segments with nominal diameters ranging from 0.5 to 2.8 mm and nominal lengths of 42 mm. The phantoms were imaged at a range of positions between the source and the detector ({+-}16 cm relative to isocenter) and with a range of foreshortening angles (0 deg. - 75 deg.). Results: Changes in vessel phantom position created magnifications ranging from 87% to 118% relative to isocenter magnification. Average diameter errors were less than 0.15 mm. Average length measurements were within 1% (0.3 mm) of the true length. No trends were observed between measurement accuracy and magnification. Changes in vessel phantom orientation resulted in decreased apparent length down to 28% of the original nonforeshortened length. Average diameter

  18. Arecibo Radar Observation of Near-Earth Asteroids: Expanded Sample Size, Determination of Radar Albedos, and Measurements of Polarization Ratios

    Science.gov (United States)

    Lejoly, Cassandra; Howell, Ellen S.; Taylor, Patrick A.; Springmann, Alessondra; Virkki, Anne; Nolan, Michael C.; Rivera-Valentin, Edgard G.; Benner, Lance A. M.; Brozovic, Marina; Giorgini, Jon D.

    2017-10-01

    The Near-Earth Asteroid (NEA) population ranges in size from a few meters to more than 10 kilometers. NEAs have a wide variety of taxonomic classes, surface features, and shapes, including spheroids, binary objects, contact binaries, elongated, as well as irregular bodies. Using the Arecibo Observatory planetary radar system, we have measured apparent rotation rate, radar reflectivity, apparent diameter, and radar albedos for over 350 NEAs. The radar albedo is defined as the radar cross-section divided by the geometric cross-section. If a shape model is available, the actual cross-section is known at the time of the observation. Otherwise we derive a geometric cross-section from a measured diameter. When radar imaging is available, the diameter was measured from the apparent range depth. However, when radar imaging was not available, we used the continuous wave (CW) bandwidth radar measurements in conjunction with the period of the object. The CW bandwidth provides apparent rotation rate, which, given an independent rotation measurement, such as from lightcurves, constrains the size of the object. We assumed an equatorial view unless we knew the pole orientation, which gives a lower limit on the diameter. The CW also provides the polarization ratio, which is the ratio of the SC and OC cross-sections.We confirm the trend found by Benner et al. (2008) that taxonomic types E and V have very high polarization ratios. We have obtained a larger sample and can analyze additional trends with spin, size, rotation rate, taxonomic class, polarization ratio, and radar albedo to interpret the origin of the NEAs and their dynamical processes. The distribution of radar albedo and polarization ratio at the smallest diameters (≤50 m) differs from the distribution of larger objects (>50 m), although the sample size is limited. Additionally, we find more moderate radar albedos for the smallest NEAs when compared to those with diameters 50-150 m. We will present additional trends we

  19. Distribution of the In-Vessel Diagnostics in ITER Tokamak

    Energy Technology Data Exchange (ETDEWEB)

    González, Jorge, E-mail: Jorge.Gonzalez@iter.org [Rüecker Lypsa, Carretera del Prat, 65, Cornellá de Llobregat (Spain); Clough, Matthew; Martin, Alex; Woods, Nick; Suarez, Alejandro [ITER Organization, Route de Vinon sur Verdon-CS 90 046 13067 Saint Paul Lez Durance (France); Martinez, Gonzalo [Technical University Of Catalonia (UPC), Barcelona-Tech, Barcelona (Spain); Stefan, Gicquel; Yunxing, Ma [ITER Organization, Route de Vinon sur Verdon-CS 90 046 13067 Saint Paul Lez Durance (France)

    2017-01-15

    The ITER In-Vessel Diagnostics have been distributed around the In-Vessel shell to understand burning plasma physics and assist in machine operation. Each diagnostics component has its own requirements, constraints, and even exclusion among them for the highly complex In-Vessel environment. The size of the plasma, the requirement to be able to align the blanket system to the magnetic centre of the machine, the cooling requirements of the blanket system and the size of the pressure vessel itself all add to the difficulties of integrating these systems into the remaining space available. The available space for the cables inside the special trays (in-Vessel looms) is another constraint to allocate In-Vessel electrical sensors. Besides this, there are issues with the Assembly sequences and surface & volumetric neutron heating considerations that have imposed several additional restrictions.

  20. A high sensitivity optically stimulated luminescence scanning system for measurement of single sand-sized grains

    DEFF Research Database (Denmark)

    Duller, G.A.T.; Bøtter-Jensen, L.; Kohsiek, P.

    1999-01-01

    An instrument has been designed for the routine analysis of the optically stimulated luminescence signal from single grains of sand. The system is capable of analysing over 3000 individual grains in a single measurement sequence, and the OSL signal from each grain can be read in less than 3 s....... The design principles are described, along with preliminary measurements that illustrate the operation of the system and its capabilities....

  1. Influence of pupil size on measurements made with the Lens Opacity Meter 701.

    OpenAIRE

    Clarke, M P; Pearson, J C; Vernon, S A; Matthews, J C

    1990-01-01

    The Lens Opacity Meter 701 (Interzeag, Switzerland) is a recently developed instrument for assessing cataract. It measures the degree of scatter of a red light beam by the lens. Fifty patients prior to cataract surgery had measurements made before and after dilatation of the pupil. Inconsistent results were found at pupil diameters of less than 4 mm. It is postulated that this was due to absorption of scattered light by the iris.

  2. Influence of pupil size on measurements made with the Lens Opacity Meter 701.

    Science.gov (United States)

    Clarke, M P; Pearson, J C; Vernon, S A; Matthews, J C

    1990-09-01

    The Lens Opacity Meter 701 (Interzeag, Switzerland) is a recently developed instrument for assessing cataract. It measures the degree of scatter of a red light beam by the lens. Fifty patients prior to cataract surgery had measurements made before and after dilatation of the pupil. Inconsistent results were found at pupil diameters of less than 4 mm. It is postulated that this was due to absorption of scattered light by the iris.

  3. Deconvolution of detector size effect for output factor measurement for narrow Gamma Knife radiosurgery beams

    Science.gov (United States)

    Bednarz, G.; Saiful Huq, M.; Rosenow, U. F.

    2002-10-01

    This paper presents the results of measurements of output factors (OFs) for a model U Gamma Knife collimator, with special emphasis on the accurate determination of the OF for the 4 mm collimator (OF4). In the past, the OF4 was set to 0.800 relative to the 18 mm collimator. Recently, the manufacturer has recommended a new value of 0.870 for OF4. However, most centres still use the old value of the OF4. In the present study, the Gamma Knife OFs were measured using a commercially available miniature diamond detector and a miniature 0.006 cc ion chamber, which was especially designed for the task. The measured OF4 were corrected for spatial averaging effects by measuring dose profiles for the 4 mm collimator with the same detectors and deconvolving their response from the measured profiles. A Gaussian kernel was used to describe the detector response. The relative OFs measured with the diamond detector/ion chamber were 0.986/0.982, 0.953/0.935 and 0.812/0.765 for the 14, 8 and 4 mm collimators, respectively, as compared with the manufacturer's values of 0.984, 0.956 and 0.87. The corrected OF4 was 0.881 +/- 0.012 for the diamond detector and 0.851 +/- 0.012 for the ion chamber, supporting the manufacturer's revised value for this collimator.

  4. Measurement of myocardial perfusion and infarction size using computer-aided diagnosis system for myocardial contrast echocardiography.

    Science.gov (United States)

    Du, Guo-Qing; Xue, Jing-Yi; Guo, Yanhui; Chen, Shuang; Du, Pei; Wu, Yan; Wang, Yu-Hang; Zong, Li-Qiu; Tian, Jia-Wei

    2015-09-01

    Proper evaluation of myocardial microvascular perfusion and assessment of infarct size is critical for clinicians. We have developed a novel computer-aided diagnosis (CAD) approach for myocardial contrast echocardiography (MCE) to measure myocardial perfusion and infarct size. Rabbits underwent 15 min of coronary occlusion followed by reperfusion (group I, n = 15) or 60 min of coronary occlusion followed by reperfusion (group II, n = 15). Myocardial contrast echocardiography was performed before and 7 d after ischemia/reperfusion, and images were analyzed with the CAD system on the basis of eliminating particle swarm optimization clustering analysis. The myocardium was quickly and accurately detected using contrast-enhanced images, myocardial perfusion was quantitatively calibrated and a color-coded map calibrated by contrast intensity and automatically produced by the CAD system was used to outline the infarction region. Calibrated contrast intensity was significantly lower in infarct regions than in non-infarct regions, allowing differentiation of abnormal and normal myocardial perfusion. Receiver operating characteristic curve analysis documented that -54-pixel contrast intensity was an optimal cutoff point for the identification of infarcted myocardium with a sensitivity of 95.45% and specificity of 87.50%. Infarct sizes obtained using myocardial perfusion defect analysis of original contrast images and the contrast intensity-based color-coded map in computerized images were compared with infarct sizes measured using triphenyltetrazolium chloride staining. Use of the proposed CAD approach provided observers with more information. The infarct sizes obtained with myocardial perfusion defect analysis, the contrast intensity-based color-coded map and triphenyltetrazolium chloride staining were 23.72 ± 8.41%, 21.77 ± 7.8% and 18.21 ± 4.40% (% left ventricle) respectively (p > 0.05), indicating that computerized myocardial contrast echocardiography can

  5. 2013 Vessel Density

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Automatic Identification Systems (AIS) are a navigation safety device that transmits and monitors the location and characteristics of many vessels in U.S. and...

  6. 2011 Passenger Vessel Density

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Automatic Identification Systems (AIS) are a navigation safety device that transmits and monitors the location and characteristics of many vessels in U.S. and...

  7. 2011 Vessel Density

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Automatic Identification Systems (AIS) are a navigation safety device that transmits and monitors the location and characteristics of many vessels in U.S. and...

  8. 2013 Passenger Vessel Density

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Automatic Identification Systems (AIS) are a navigation safety device that transmits and monitors the location and characteristics of many vessels in U.S. and...

  9. 2013 Tanker Vessel Density

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Automatic Identification Systems (AIS) are a navigation safety device that transmits and monitors the location and characteristics of many vessels in U.S. and...

  10. 2013 Cargo Vessel Density

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Automatic Identification Systems (AIS) are a navigation safety device that transmits and monitors the location and characteristics of many vessels in U.S. and...

  11. High Performance Marine Vessels

    CERN Document Server

    Yun, Liang

    2012-01-01

    High Performance Marine Vessels (HPMVs) range from the Fast Ferries to the latest high speed Navy Craft, including competition power boats and hydroplanes, hydrofoils, hovercraft, catamarans and other multi-hull craft. High Performance Marine Vessels covers the main concepts of HPMVs and discusses historical background, design features, services that have been successful and not so successful, and some sample data of the range of HPMVs to date. Included is a comparison of all HPMVs craft and the differences between them and descriptions of performance (hydrodynamics and aerodynamics). Readers will find a comprehensive overview of the design, development and building of HPMVs. In summary, this book: Focuses on technology at the aero-marine interface Covers the full range of high performance marine vessel concepts Explains the historical development of various HPMVs Discusses ferries, racing and pleasure craft, as well as utility and military missions High Performance Marine Vessels is an ideal book for student...

  12. Cheboygan Vessel Base

    Data.gov (United States)

    Federal Laboratory Consortium — Cheboygan Vessel Base (CVB), located in Cheboygan, Michigan, is a field station of the USGS Great Lakes Science Center (GLSC). CVB was established by congressional...

  13. Maury Journals - US Vessels

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — U.S. vessels observations, after the 1853 Brussels Conference that set International Maritime Standards, modeled after Maury Marine Standard Observations.

  14. 2011 Cargo Vessel Density

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Automatic Identification Systems (AIS) are a navigation safety device that transmits and monitors the location and characteristics of many vessels in U.S. and...

  15. 2011 Tanker Vessel Density

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Automatic Identification Systems (AIS) are a navigation safety device that transmits and monitors the location and characteristics of many vessels in U.S. and...

  16. 2013 Fishing Vessel Density

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Automatic Identification Systems (AIS) are a navigation safety device that transmits and monitors the location and characteristics of many vessels in U.S. and...

  17. Coastal Logbook Survey (Vessels)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains catch (landed catch) and effort for fishing trips made by vessels that have been issued a Federal permit for the Gulf of Mexico reef fish,...

  18. Interlaboratory comparison for the measurement of particle size and zeta potential of silica nanoparticles in an aqueous suspension

    Science.gov (United States)

    Lamberty, Andrée; Franks, Katrin; Braun, Adelina; Kestens, Vikram; Roebben, Gert; Linsinger, Thomas P. J.

    2011-12-01

    The Institute for Reference Materials and Measurements has organised an interlaboratory comparison (ILC) to allow the participating laboratories to demonstrate their proficiency in particle size and zeta potential measurements on monomodal aqueous suspensions of silica nanoparticles in the 10-100 nm size range. The main goal of this ILC was to identify competent collaborators for the production of certified nanoparticle reference materials. 38 laboratories from four different continents participated in the ILC with different methods for particle sizing and determination of zeta potential. Most of the laboratories submitted particle size results obtained with centrifugal liquid sedimentation (CLS), dynamic light scattering (DLS) or electron microscopy (EM), or zeta potential values obtained via electrophoretic light scattering (ELS). The results of the laboratories were evaluated using method-specific z scores, calculated on the basis of consensus values from the ILC. For CLS (13 results) and EM (13 results), all reported values were within the ±2 | z| interval. For DLS, 25 of the 27 results reported were within the ±2 | z| interval, the two other results were within the ±3 | z| interval. The standard deviations of the corresponding laboratory mean values varied between 3.7 and 6.5%, which demonstrates satisfactory interlaboratory comparability of CLS, DLS and EM particle size values. From the received test reports, a large discrepancy was observed in terms of the laboratory's quality assurance systems, which are equally important for the selection of collaborators in reference material certification projects. Only a minority of the participating laboratories is aware of all the items that are mandatory in test reports compliant to ISO/IEC 17025 (ISO General requirements for the competence of testing and calibration laboratories. International Organisation for Standardization, Geneva, 2005b). The absence of measurement uncertainty values in the reports, for

  19. Particle Size-Specific Magnetic Measurements as a Tool for Enhancing Our Understanding of the Bulk Magnetic Properties of Sediments

    Directory of Open Access Journals (Sweden)

    Robert G. Hatfield

    2014-10-01

    Full Text Available Bulk magnetic properties of soils and sediments are often sensitive proxies for environmental change but commonly require interpretation in terms of the different sources of magnetic minerals (or components that combine to generate them. Discrimination of different components in the bulk magnetic record is often attempted through endmember unmixing and/or high resolution measurements that can require intensive measurement plans, assume linear additivity, and sometimes have difficulty in discriminating a large number of sources. As an alternative, magnetic measurements can be made on isolated sediment fractions that constitute the bulk sample. When these types of measurements are taken, heterogeneity is frequently observed between the magnetic properties of different fractions, suggesting different magnetic components often associate with different physical grain sizes. Using a particle size-specific methodology, individual components can be isolated and studied and bulk magnetic properties can be linked to, and isolated from, sedimentological variations. Deconvolving sedimentary and magnetic variability in this way has strong potential for increased understanding of how magnetic fragments are carried in natural systems, how they vary with different source(s, and allows for a better assessment of the effect environmental variability has in driving bulk magnetic properties. However, despite these benefits, very few studies exploit the information they can provide. Here, I present an overview of the different sources of magnetic minerals, why they might associate with different sediment fractions, how bulk magnetic measurements have been used to understand the contribution of different components to the bulk magnetic record, and outline how particle size-specific magnetic measurements can assist in their better understanding. Advantages and disadvantages of this methodology, their role alongside bulk magnetic measurements, and potential future

  20. Concentration and size distribution measurements of nanoparticles in ambient air; Anzahlkonzentrations- und Groessenverteilungsmessung von Nanopartikeln in der Aussenluft

    Energy Technology Data Exchange (ETDEWEB)

    Horn, H.G. [TSI GmbH, Aachen (Germany)

    2005-07-01

    The outdoor air in continental Europe can contain high concentrations of ultrafine particles. These nanoparticles influence air quality, climate, general well-being and human health. Recently, nanoparticles were related to both pulmonary and cardio-vascular diseases. The measurement of the number concentration of ultrafine particles in outdoor air requires special techniques. Condensation particle counters (CPC) measure the particle number concentration by means of condensing a working fluid vapour on the particles. This makes nanoparticles visible and detectable. If combined with the so-called differential mobility analysis, particle size distributions can be measured. The requirements for instruments used in outdoor air measurements differ from the requirements for instruments designed for the laboratory. This is especially true for instruments used in monitoring networks. This paper discusses the measurement techniques and the special requirements. (orig.)

  1. Measurement of the size of the isoplanatic patch using a phase-correcting telescope

    Energy Technology Data Exchange (ETDEWEB)

    Pollaine, S.; Buffington, A.; Crawford, F.S.

    1979-01-01

    In the presence of several-arc-second seeing at Mt. Wilson observatory, a flexible-mirror image-sharpening telescope produced diffraction-limited (0.5 arc s) images of the primary stars in the double star systems of Castor (..cap alpha.. Gem), Algieba (..gamma.. Leo) and Almach (..gamma.. And). The images of both the primary and the companion star were simultaneously sharpened for Castor (separation 2 arc s ) and Algieba (4 arc s) but not for Almach (10 arc s). Thus the size of the isoplanatic patch lay between 4 and 10 arc s. Using a simple model, we conclude that the bulk of the turbulent air responsible for the seeing lay between 1.1 and 1.7 km above ground.

  2. Vibroacoustic Analysis of Cyclic Structures by Using Dof’s Size Reduction and Holographic Measurements

    Directory of Open Access Journals (Sweden)

    Abdelkhalak El Hami

    2006-01-01

    Full Text Available We propose a method for the vibroacoustic analysis of structures having symmetry properties. This method is based on the reduction of the number of the degrees of freedom involved (size reduction and the use of experimental data (confrontation numerical/experimental. We propose the extension of the method of the linear representations of finite symmetry groups to problems of coupling fluid-structure. This approach, while keeping the quality of the approximations, leads to a significant reduction of the number of degrees of freedom, with a maximal reduction for the so called repetitive structures. Finally, we present a practical case of modal analysis – in air and water – of a ship propeller formed by 3 stainless steel blades. The experimental results are obtained by using the whole-field, non-contact technique of electronic holography.

  3. Urban Skylines: building heights and shapes as measures of city size

    CERN Document Server

    Schläpfer, Markus; Bettencourt, Luís M A

    2015-01-01

    The shape of buildings plays a critical role in the energy efficiency, lifestyles, land use and infrastructure systems of cities. Thus, as most of the world's cities continue to grow and develop, understanding the interplay between the characteristics of urban environments and the built form of cities is essential to achieve local and global sustainability goals. Here, we compile and analyze the most extensive data set of building shapes to date, covering more than 4.8 million individual buildings across several major cities in North America. We show that average building height increases systematically with city size and follows theoretical predictions derived from urban scaling theory. We also study the allometric relationship between surface area and volume of buildings in terms of characteristic shape parameters. This allows us to demonstrate that the reported trend towards higher (and more voluminous) buildings effectively decreases the average surface-to-volume ratio, suggesting potentially significant ...

  4. Measuring NLR Oligomerization I: Size Exclusion Chromatography, Co-immunoprecipitation, and Cross-Linking.

    Science.gov (United States)

    Khare, Sonal; Radian, Alexander D; Dorfleutner, Andrea; Stehlik, Christian

    2016-01-01

    Oligomerization of nod-like receptors (NLRs) can be detected by several biochemical techniques dependent on the stringency of protein-protein interactions. Some of these biochemical methods can be combined with functional assays, such as caspase-1 activity assay. Size exclusion chromatography (SEC) allows separation of native protein lysates into different sized complexes by fast protein liquid chromatography (FPLC) for follow-up analysis. Using co-immunoprecipitation (co-IP), combined with SEC or on its own, enables subsequent antibody-based purification of NLR complexes and associated proteins, which can then be analyzed by immunoblot and/or subjected to functional caspase-1 activity assay. Chemical cross-linking covalently joins two or more molecules, thus capturing the oligomeric state with high sensitivity and stability. Apoptosis-associated speck-like protein containing a caspase activation domain (ASC) oligomerization has been successfully used as readout for NLR or AIM2-like receptor (ALR) inflammasome activation in response to various pathogen- or damage-associated molecular patterns (PAMPs or DAMPs) in human and mouse macrophages and THP-1 cells. Here, we provide a detailed description of the methods used for NLRP7 oligomerization in response to infection with Staphylococcus aureus (S. aureus) in primary human macrophages, co-immunoprecipitation and immunoblot analysis of NLRP7 and NLRP3 inflammasome complexes, as well as caspase-1 activity assays. Also, ASC oligomerization is shown in response to dsDNA, LPS/ATP, and LPS/nigericin in mouse bone marrow-derived macrophages (BMDMs) and/or THP-1 cells or human primary macrophages.

  5. Hard X-Ray Flare Source Sizes Measured with the Ramaty High Energy Solar Spectroscopic Imager

    Science.gov (United States)

    Dennis, Brian R.; Pernak, Rick L.

    2009-01-01

    Ramaty High Energy Solar Spectroscopic Imager (RHESSI) observations of 18 double hard X-ray sources seen at energies above 25 keV are analyzed to determine the spatial extent of the most compact structures evident in each case. The following four image reconstruction algorithms were used: Clean, Pixon, and two routines using visibilities maximum entropy and forward fit (VFF). All have been adapted for this study to optimize their ability to provide reliable estimates of the sizes of the more compact sources. The source fluxes, sizes, and morphologies obtained with each method are cross-correlated and the similarities and disagreements are discussed. The full width at half-maximum (FWHM) of the major axes of the sources with assumed elliptical Gaussian shapes are generally well correlated between the four image reconstruction routines and vary between the RHESSI resolution limit of approximately 2" up to approximately 20" with most below 10". The FWHM of the minor axes are generally at or just above the RHESSI limit and hence should be considered as unresolved in most cases. The orientation angles of the elliptical sources are also well correlated. These results suggest that the elongated sources are generally aligned along a flare ribbon with the minor axis perpendicular to the ribbon. This is verified for the one flare in our list with coincident Transition Region and Coronal Explorer (TRACE) images. There is evidence for significant extra flux in many of the flares in addition to the two identified compact sources, thus rendering the VFF assumption of just two Gaussians inadequate. A more realistic approximation in many cases would be of two line sources with unresolved widths. Recommendations are given for optimizing the RHESSI imaging reconstruction process to ensure that the finest possible details of the source morphology become evident and that reliable estimates can be made of the source dimensions.

  6. 6 MV x-ray spectra obtained by small field size attenuation measurements in water and their use in small field size dosimetry

    Science.gov (United States)

    Lu, Cenney W.

    Direct measurement of x-ray spectra produced by medical linear accelerators is not possible because of high intensity and energy of the radiation involved. Knowledge of energy spectra are very useful in determination of parameters that convert from ionization chamber measurements to absorbed dose. Many indirect methods for determination of x-ray spectra in therapy beams have been developed. In the present work photon beams generated by a 6-MV Varian 6000 linear accelerator were used to obtain small field (0.5 x 0.5 to 4.0 x 4.0 cm 2 at 0.5 cm increments per side) attenuation values in water for the depths from 5 to 30 cm, at 5 cm increments. Attenuation values lying between those depths were interpolated using the Newton-Coates method and attenuation data of zero-field was obtained by extrapolation. Based on the measured attenuation curves, the relative air kerma and photon energy x-ray spectra were derived for all investigating fields using a user input parameter program and an iterative procedure. The attenuation curves of the radiation fields were calculated using the reconstructed spectrum. They were compared with the measured attenuation data at each iteration step until a satisfactory fit between the measured and calculated attenuation curves was obtained. In order for derived spectra to be of practical use in radiotherapy treatment planning, they must accurate reproduce measured dose distribution data. From the knowledge of the incident beam attenuation and the incident x-ray energy spectrum for the zero-field, the percentage depth dose of the zero-field was calculated at different points along the Central Axis. The percentage depth doses of larger fields were calculated by applying of the Relative Scatter Factor to the percentage depth dose of the zero-field. The agreement was within 1.11% for all fields, ranging from 0.5 x 0.5 to 4.0 x 4.0 cm2 at 0.5 cm increments per side. Further, the reconstructed spectrum for 4 x 4 cm2 field size was used in Monte

  7. Vessel detection in ultrasound images using deep convolutional neural networks

    OpenAIRE

    Smistad, Erik; Løvstakken, Lasse

    2016-01-01

    Deep convolutional neural networks have achieved great results on image classification problems. In this paper, a new method using a deep convolutional neural network for detecting blood vessels in B-mode ultrasound images is presented. Automatic blood vessel detection may be useful in medical applications such as deep venous thrombosis detection, anesthesia guidance and catheter placement. The proposed method is able to determine the position and size of the vessels in images in real-time. 1...

  8. 9th DITANET Topical Workshop on Non-Invasive Beam Size Measurement for High Brightness Proton and Heavy Ion Accelerators

    CERN Document Server

    2013-01-01

    The main aim of this workshop is to prepare non-invasive transverse beam size monitors in the LHC and its injector chain to fulfil the future emittance measurement requirements for LHC beams. This will be focussed on improvements to existing systems for implementation during the long shutdown in 2013-2014 and on concepts that could be foreseen for installation during the second long shutdown in 2018.

  9. Some insights into the condensing vapors driving new particle growth to CCN sizes on the basis of hygroscopicity measurements

    Science.gov (United States)

    Wu, Z. J.; Poulain, L.; Birmili, W.; Größ, J.; Niedermeier, N.; Wang, Z. B.; Herrmann, H.; Wiedensohler, A.

    2015-11-01

    New particle formation (NPF) and growth is an important source of cloud condensation nuclei (CCN). In this study, we investigated the chemical species driving new particle growth to the CCN sizes on the basis of particle hygroscopicity measurements carried out at the research station Melpitz, Germany. Three consecutive NPF events occurred during summertime were chosen as examples to perform the study. Hygroscopicity measurements showed that the (NH4)2SO4-equivalent water-soluble fraction accounts for 20 and 16 % of 50 and 75 nm particles, respectively, during the NPF events. Numerical analysis showed that the ratios of H2SO4 condensational growth to the observed particle growth were 20 and 13 % for 50 and 75 nm newly formed particles, respectively. Aerosol mass spectrometer measurements showed that an enhanced mass fraction of sulfate and ammonium in the newly formed particles was observed when new particles grew to the sizes larger than 30 nm shortly after the particle formation period. At a later time, the secondary organic species played a key role in the particle growth. Both hygroscopicity and aerosol mass spectrometer (AMS) measurements and numerical analysis confirmed that organic compounds were major contributors driving particle growth to CCN sizes. The critical diameters at different supersaturations estimated using AMS data and κ-Köhler theory increased significantly during the later course of NPF events. This indicated that the enhanced organic mass fraction caused a reduction in CCN efficiency of newly formed particles. Our results implied that the CCN production associated with atmospheric nucleation may be overestimated if assuming that newly formed particles can serve as CCN once they grow to a fixed particle size, an assumption made in some previous studies, especially for organic-rich environments. In our study, the enhancement in CCN number concentration associated with individual NPF events were 63, 66, and 69 % for 0.1, 0.4, and 0

  10. Accelerating inference for diffusions observed with measurement error and large sample sizes using approximate Bayesian computation

    DEFF Research Database (Denmark)

    Picchini, Umberto; Forman, Julie Lyng

    2016-01-01

    a nonlinear stochastic differential equation model observed with correlated measurement errors and an application to protein folding modelling. An approximate Bayesian computation (ABC)-MCMC algorithm is suggested to allow inference for model parameters within reasonable time constraints. The ABC algorithm...

  11. Determination of suspended particulate matter concentration from turbidity measurements: particle size effects and calibration procedures

    Science.gov (United States)

    Pfannkuche, J.; Schmidt, A.

    2003-07-01

    Measurements of suspended particulate matter concentration and turbidity point towards the possibility of a site-specific algorithm (SPM), relating SPM to nephelometric turbidity units (NTU). In this paper regression models are presented that account for changes in the relationship of SPM and NTU as a result of changes in particle properties. The models have been developed by the use of daily measurements of SPM concentration and a continuous record of turbidity for the period from June 1996 to February 2001 in the River Elbe, a major river in the eastern part of Germany.The effect of changes in the particle properties with increasing water discharge was taken into account by varying the slope of a linear regression equation according to a logistic function. Water discharge, Q, was defined to be the only variable of this function - as an adequate substitute of the parameter bottom shear stress, which cannot be measured directly. Measurements of flow velocity in the River Elbe show that bottom shear stress is related almost linearly to water discharge up to bankful discharges.Regression models with slopes varying continuously with hydraulic parameters may account for the effects resulting from changes of particle characteristics and thus may have some advantages compared with models with a constant slope or models calibrated for different seasons.

  12. Thermal Conductivity of Straw Bales: Full Size Measurements Considering the Direction of the Heat Flow

    Directory of Open Access Journals (Sweden)

    Jean-Philippe Costes

    2017-02-01

    Full Text Available The thermal conductivity of straw bales is an intensively discussed topic in the international straw bale community. Straw bales are, by nature, highly heterogeneous and porous. They can have a relatively large range of density and the baling process can influence the way the fibres are organised within the bale. In addition, straw bales have a larger thickness than most of the insulating materials that can be found in the building industry. Measurement apparatus is usually not designed for such thicknesses, and most of the thermal conductivity values that can be found in the literature are defined based on samples in which the straw bales are resized. During this operation, the orientation of the fibres and the density may not be preserved. This paper starts with a literature review of straw bale thermal conductivity measurements and presents a measuring campaign performed with a specific Guarded Hot Plate, designed to measure samples up to 50 cm thick. The influence of the density is discussed thoroughly. Representative values are proposed for a large range of straw bales to support straw-bale development in the building industry.

  13. Body size and measurement of species diversity in large grazing mammals

    NARCIS (Netherlands)

    Oindo, B.O.

    2002-01-01

    Species are by definition different from each other. This fact favours ranking rather than additive indices. However, ecologists have measured species diversity in terms of species richness, or by combining species richness with the relative abundance of species within an area. Both methods raise

  14. Morphological characterization of carbon nanofiber aerosol using tandem mobility and aerodynamic size measurements

    Energy Technology Data Exchange (ETDEWEB)

    Deye, Gregory J.; Kulkarni, Pramod, E-mail: pskulkarni@cdc.gov; Ku, Bon Ki [National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention (United States)

    2012-09-15

    Characterizing microstructural and transport properties of non-spherical particles, such as carbon nanofibers (CNF), is important for understanding their transport and deposition in human respiratory system and engineered devices such as particle filters. We describe an approach to obtain morphological information of non-spherical particles using a tandem system of differential mobility analyzer (DMA) and an electrical low-pressure impactor (ELPI). Effective density, dynamic shape factors (DSF), particle mass, and fractal dimension-like mass-scaling exponent of nanofibers were derived using the measured mobility and aerodynamic diameters, along with the known material density of CNF. Multiple charging of particles during DMA classification, which tends to bias the measured shape factors and particle mass toward higher values, was accounted for using a correction procedure. Particle mass derived from DMA-ELPI measurements agreed well with the direct mass measurements using an aerosol particle mass analyzer. Effective densities, based on mobility diameters, ranged from 0.32 to 0.67 g cm{sup -3}. The DSF of the CNF ranged from 1.8 to 2.3, indicating highly non-spherical particle morphologies.

  15. Morphological characterization of carbon nanofiber aerosol using tandem mobility and aerodynamic size measurements

    Science.gov (United States)

    Deye, Gregory J.; Kulkarni, Pramod; Ku, Bon Ki

    2012-09-01

    Characterizing microstructural and transport properties of non-spherical particles, such as carbon nanofibers (CNF), is important for understanding their transport and deposition in human respiratory system and engineered devices such as particle filters. We describe an approach to obtain morphological information of non-spherical particles using a tandem system of differential mobility analyzer (DMA) and an electrical low-pressure impactor (ELPI). Effective density, dynamic shape factors (DSF), particle mass, and fractal dimension-like mass-scaling exponent of nanofibers were derived using the measured mobility and aerodynamic diameters, along with the known material density of CNF. Multiple charging of particles during DMA classification, which tends to bias the measured shape factors and particle mass toward higher values, was accounted for using a correction procedure. Particle mass derived from DMA-ELPI measurements agreed well with the direct mass measurements using an aerosol particle mass analyzer. Effective densities, based on mobility diameters, ranged from 0.32 to 0.67 g cm-3. The DSF of the CNF ranged from 1.8 to 2.3, indicating highly non-spherical particle morphologies.

  16. Evaluating the effect of annotation size on measures of semantic similarity

    KAUST Repository

    Kulmanov, Maxat

    2017-02-13

    Background: Ontologies are widely used as metadata in biological and biomedical datasets. Measures of semantic similarity utilize ontologies to determine how similar two entities annotated with classes from ontologies are, and semantic similarity is increasingly applied in applications ranging from diagnosis of disease to investigation in gene networks and functions of gene products.

  17. Measuring rat kidney glomerular number and size in vivo with MRI.

    Science.gov (United States)

    Baldelomar, Edwin J; Charlton, Jennifer R; Beeman, Scott C; Bennett, Kevin M

    2017-11-01

    Nephron number is highly variable in humans and is thought to play an important role in renal health. Chronic kidney disease (CKD) is the result of too few nephrons to maintain homeostasis. Currently, nephron number estimates can only be determined invasively or as a terminal assessment. Due to a lack of tools to measure and track nephron number in the living, the early stages of CKD often go unrecognized, preventing early intervention that might halt the progression of CKD. In this work, we present a technique to directly measure glomerular number (Nglom) and volume in vivo in the rat kidney (n=8) using MRI enhanced with the novel contrast agent cationized ferritin (CFE-MRI). Adult male rats were administered intravenous cationized ferritin (CF) and imaged in vivo with MRI. Glomerular number was measured and each glomerulus was spatially mapped in 3D in the image. Mean apparent glomerular volume (aVglom) and intra-renal distribution of the individual glomerular volume (IGV) were also measured. These metrics were compared between images of the same kidneys scanned in vivo and ex vivo with CFE-MRI. In vivo Nglom and aVglom correlated to ex vivo metrics within the same kidneys and were within 10% of Nglom and aVglom previously validated by stereologic methods. This is the first description of direct in vivo measurements of Nglom and aVglom, introducing an opportunity to investigate mechanisms of renal disease progression and therapeutic response over time. Copyright © 2017, American Journal of Physiology-Renal Physiology.

  18. Size-resolved measurement of the mixing state of soot in the megacity Beijing, China: Diurnal cycle, aging and parameterization

    Science.gov (United States)

    Cheng, Y. F.; Su, H.; Rose, D.; Gunthe, S. S.; Berghof, M.; Wehner, B.; Achtert, P.; Nowak, A.; Takegawa, N.; Kondo, Y.; Shiraiwa, M.; Gong, Y. G.; Shao, M.; Hu, M.; Zhu, T.; Zhang, Y. H.; Wiedensohler, A.; Andreae, M. O.; Pöschl, U.

    2013-05-01

    In the summer of 2006, measurements of the mixing state of non-volatile particles were carried out at a suburban site of Beijing in the North China Plain by using a VTDMA. In this study, we perform an in-depth analysis of VTDMA results, focusing on the following topics: (1) comparison of the mixing state of soot measured by a VTDMA and the aerosol hygroscopicity mixing state determined by a CCN (cloud condensation nuclei) counter; (2) diurnal variation and evolution of soot mixing state at different size ranges; (3) calculation of kex→in and the influence of emissions on it; and (4) potential parameterization methods.

  19. Assessing the precision of a time-sampling-based study among GPs: balancing sample size and measurement frequency.

    Science.gov (United States)

    van Hassel, Daniël; van der Velden, Lud; de Bakker, Dinny; van der Hoek, Lucas; Batenburg, Ronald

    2017-12-04

    Our research is based on a technique for time sampling, an innovative method for measuring the working hours of Dutch general practitioners (GPs), which was deployed in an earlier study. In this study, 1051 GPs were questioned about their activities in real time by sending them one SMS text message every 3 h during 1 week. The required sample size for this study is important for health workforce planners to know if they want to apply this method to target groups who are hard to reach or if fewer resources are available. In this time-sampling method, however, standard power analyses is not sufficient for calculating the required sample size as this accounts only for sample fluctuation and not for the fluctuation of measurements taken from every participant. We investigated the impact of the number of participants and frequency of measurements per participant upon the confidence intervals (CIs) for the hours worked per week. Statistical analyses of the time-use data we obtained from GPs were performed. Ninety-five percent CIs were calculated, using equations and simulation techniques, for various different numbers of GPs included in the dataset and for various frequencies of measurements per participant. Our results showed that the one-tailed CI, including sample and measurement fluctuation, decreased from 21 until 3 h between one and 50 GPs. As a result of the formulas to calculate CIs, the increase of the precision continued and was lower with the same additional number of GPs. Likewise, the analyses showed how the number of participants required decreased if more measurements per participant were taken. For example, one measurement per 3-h time slot during the week requires 300 GPs to achieve a CI of 1 h, while one measurement per hour requires 100 GPs to obtain the same result. The sample size needed for time-use research based on a time-sampling technique depends on the design and aim of the study. In this paper, we showed how the precision of the

  20. 76 FR 49975 - Inspection of Towing Vessels

    Science.gov (United States)

    2011-08-11

    ... related materials. All comments received will be posted, without change, to http://www.regulations.gov and... comments and material received during the comment period and may change this proposed rule based on your... consideration its size, organizational structure, and vessel types and services. Towing Safety Management System...

  1. Ultrasound measurement of the size of the anterior tibial muscle group: the effect of exercise and leg dominance

    LENUS (Irish Health Repository)

    McCreesh, Karen

    2011-09-13

    Abstract Background Knowledge of normal muscle characteristics is crucial in planning rehabilitation programmes for injured athletes. There is a high incidence of ankle and anterior tibial symptoms in football players, however little is known about the effect of limb dominance on the anterior tibial muscle group (ATMG). The purpose of this study was to assess the effect of limb dominance and sports-specific activity on ATMG thickness in Gaelic footballers and non-football playing controls using ultrasound measurements, and to compare results from transverse and longitudinal scans. Methods Bilateral ultrasound scans were taken to assess the ATMG size in 10 Gaelic footballers and 10 sedentary controls (age range 18-25 yrs), using a previously published protocol. Both transverse and longitudinal images were taken. Muscle thickness measurements were carried out blind to group and side of dominance, using the Image-J programme. Results Muscle thickness on the dominant leg was significantly greater than the non-dominant leg in the footballers with a mean difference of 7.3%, while there was no significant dominance effect in the controls (p < 0.05). There was no significant difference between the measurements from transverse or longitudinal scans. Conclusions A significant dominance effect exists in ATMG size in this group of Gaelic footballers, likely attributable to the kicking action involved in the sport. This should be taken into account when rehabilitating footballers with anterior tibial pathology. Ultrasound is a reliable tool to measure ATMG thickness, and measurement may be taken in transverse or longitudinal section.

  2. Ultrafast high-resolution in vivo volume-CTA of mice cerebral vessels.

    Science.gov (United States)

    Schambach, Sebastian J; Bag, Simona; Steil, Volker; Isaza, Cristina; Schilling, Lothar; Groden, Christoph; Brockmann, Marc A

    2009-04-01

    Animal models developed in rats and mice have become indispensable in preclinical cerebrovascular research. Points of interest include the investigation of the vascular bed and the morphology and function of the arterial, capillary, and venous vessels. Because of their extremely small caliber, in vivo examination of these vessels is extremely difficult. In the present study we have developed a method to provide fast 3D in vivo analysis of cerebral murine vessels using volume computed tomography-angiography (vCTA). Using an industrial X-ray inspection system equipped with a multifocus cone beam X-ray source and a 12-bit direct digital flatbed detector, high-speed vCTA (180 degrees rotation in 40 s. at 30 fps) was performed in anesthetized mice. During the scan an iodinated contrast agent was infused via a tail vein. Images were reconstructed using a filtered backprojection algorithm. Image analysis was performed by maximum intensity projection (MIP) and 3D volume reconstruction. All mice tolerated i.v. injection of the iodinated contrast agent well. Smallest achievable voxel size of raw data while scanning the whole neurocranium was 16 mum. Anatomy of cerebral vessels was assessable in all animals, and anatomic differences between mouse strains could easily be detected. Mean vessel diameter was measured in C57BL/6 and BALBc mice. Changes of vessel caliber were assessable by repeated vCTA. Ultra fast in vivo vCTA of murine cerebral vasculature is feasible at resolutions down to 16 mum. The technique allows the assessment of vessel caliber changes in living mice, thus providing an interesting tool to monitor different features such as vasospasm or vessel patency.

  3. Particle size distribution of brown and white rice during gastric digestion measured by image analysis.

    Science.gov (United States)

    Bornhorst, Gail M; Kostlan, Kevin; Singh, R Paul

    2013-09-01

    The particle size distribution of foods during gastric digestion indicates the amount of physical breakdown that occurred due to the peristaltic movement of the stomach walls in addition to the breakdown that initially occurred during oral processing. The objective of this study was to present an image analysis technique that was rapid, simple, and could distinguish between food components (that is, rice kernel and bran layer in brown rice). The technique was used to quantify particle breakdown of brown and white rice during gastric digestion in growing pigs (used as a model for an adult human) over 480 min of digestion. The particle area distributions were fit to a Rosin-Rammler distribution function. Brown and white rice exhibited considerable breakdown as the number of particles per image decreased over time. The median particle area (x(50)) increased during digestion, suggesting a gastric sieving phenomenon, where small particles were emptied and larger particles were retained for additional breakdown. Brown rice breakdown was further quantified by an examination of the bran layer fragments and rice grain pieces. The percentage of total particle area composed of bran layer fragments was greater in the distal stomach than the proximal stomach in the first 120 min of digestion. The results of this study showed that image analysis may be used to quantify particle breakdown of a soft food product during gastric digestion, discriminate between different food components, and help to clarify the role of food structure and processing in food breakdown during gastric digestion. © 2013 Institute of Food Technologists®

  4. Landscape selection by piping plovers has implications for measuring habitat and population size

    Science.gov (United States)

    Anteau, Michael J.; Shaffer, Terry L.; Wiltermuth, Mark T.; Sherfy, Mark H.

    2014-01-01

    How breeding birds distribute in relation to landscape-scale habitat features has important implications for conservation because those features may constrain habitat suitability. Furthermore, knowledge of these associations can help build models to improve area-wide demographic estimates or to develop a sampling stratification for research and monitoring. This is particularly important for rare species that have uneven distributions across vast areas, such as the federally listed piping plover (Charadrius melodus; hereafter plover). We examined how remotely-sensed landscape features influenced the distribution of breeding plover pairs among 2-km shoreline segments during 2006–2009 at Lake Sakakawea in North Dakota, USA. We found strong associations between remotely-sensed landscape features and plover abundance and distribution (R2 = 0.65). Plovers were nearly absent from segments with bluffs (>25 m elevation increase within 250 m of shoreline). Relative plover density (pairs/ha) was markedly greater on islands (4.84 ± 1.22 SE) than on mainlands (0.85 ± 0.17 SE). Pair numbers increased with abundance of nesting habitat (unvegetated-flat areas β^=0.28±0.08SE ). On islands, pair numbers also increased with the relative proportion of the total area that was habitat ( β^=3.27±0.46SE ). Our model could be adapted to estimate the breeding population of plovers or to make predictions that provide a basis for stratification and design of future surveys. Knowledge of landscape features, such as bluffs, that exclude use by birds refines habitat suitability and facilitates more accurate estimates of habitat and population abundance, by decreasing the size of the sampling universe. Furthermore, techniques demonstrated here are applicable to other vast areas where birds breed in sparse or uneven densities.

  5. Effects of publications in proceedings on the measure of the core size of coauthors

    Science.gov (United States)

    Miśkiewicz, Janusz

    2013-10-01

    Coauthors (CA) of a “lead investigator” (LI) can receive a rank (r) according to their “importance” in having published joint publications with the LI. It is commonly accepted, without any proof, that publications in peer review journals and for example conference proceedings do not have the same “value” in a CV, and the same applies to papers contributing to encyclopedia and book chapters. It is examined here whether the relationship between the number (J) of publications of some scientist with her/his coauthors, ranked according to their decreasing importance, i.e. J∝1/rα, as found by Ausloos (2013) [1], still holds if the overall publication list is broken into such specific types of publications. Several authors, with different careers, but mainly having worked in the field of statistical mechanics, are studied here to sort out answers to the questions. The exponent α turns out to be weakly scientist dependent, only if the maximum value of J and r is large and is ˜+1 then. The mA core value, i.e. the core number of CAs, for proceedings only is about half of the total one, i.e. when all publications are counted. Contributions to the numerical values from both encyclopedia and book chapters are marginal. The role of a time span on mA is also examined in two cases in relation to career activity considerations. It can be considered that the findings serve as a contrasting point of view on how to quantify an individual (publication) career as recently done by Petersen et al. (2010, 2012, 2011) [2-4], here emphasizing the collaboration size and evolution, rather than a citation count, moreover specifying the type of publication. Through the various mA’s one can distinguish different behavior patterns of a scientific publication with CAs.

  6. Shape and size measurements of asteroids by the HST Fine Guidance Sensors

    Science.gov (United States)

    Tanga, Paolo; Hestroffer, D.; Cellino, A.; Lattanzi, M.; di Martino, M.; Zappalá, V.

    2002-11-01

    For the first time an observing program based upon the use of the Fine Guidance Sensor (FGS) of the Hubble Space Telescope (HST) has successfully provided precise measurements of asteroid diameters and shapes. Six objects, suspected to be binary bodies, have been observed. We will give a short overview of the FGS interferometer and of the results obtained. Some bodies are generally close in shape to three axis ellipsoid; others, such as (216) Kleopatra, clearly show the hints of complex structures. The suspected duplicity of Hektor cannot be ruled out or confirmed due to the low S/N ratio.

  7. Optical sensor technology for simultaneous measurement of particle speed and concentration of micro sized particles

    DEFF Research Database (Denmark)

    Clausen, Casper; Han, Anpan; Kristensen, Martin

    2013-01-01

    Experimental characterization of a sensor technology that can measure particle speed and concentration simultaneously in liquids and gases is presented here. The basic sensor principle is based on an optical element that shapes a light beam into well-defined fringes. The technology can be described...... as a hybrid between Laser Doppler Velocimetry and Laser Particle Counters. The experimental characterization of a lab-scale setup has been performed with polystyrene particles in the range from 750 nm to 20 μm, with various particle speeds. It is shown that particle concentrations can be determined...... independently from particle speeds and is a key advantage compared to normal Laser Particle Counters....

  8. The design of high-temperature thermal conductivity measurements apparatus for thin sample size

    Directory of Open Access Journals (Sweden)

    Hadi Syamsul

    2017-01-01

    Full Text Available This study presents the designing, constructing and validating processes of thermal conductivity apparatus using steady-state heat-transfer techniques with the capability of testing a material at high temperatures. This design is an improvement from ASTM D5470 standard where meter-bars with the equal cross-sectional area were used to extrapolate surface temperature and measure heat transfer across a sample. There were two meter-bars in apparatus where each was placed three thermocouples. This Apparatus using a heater with a power of 1,000 watts, and cooling water to stable condition. The pressure applied was 3.4 MPa at the cross-sectional area of 113.09 mm2 meter-bar and thermal grease to minimized interfacial thermal contact resistance. To determine the performance, the validating process proceeded by comparing the results with thermal conductivity obtained by THB 500 made by LINSEIS. The tests showed the thermal conductivity of the stainless steel and bronze are 15.28 Wm-1K-1 and 38.01 Wm-1K-1 with a difference of test apparatus THB 500 are −2.55% and 2.49%. Furthermore, this apparatus has the capability to measure the thermal conductivity of the material to a temperature of 400°C where the results for the thermal conductivity of stainless steel is 19.21 Wm-1K-1 and the difference was 7.93%.

  9. Use of In Situ Cloud Condensation Nuclei, Extinction, and Aerosol Size Distribution Measurements to Test a Method for Retrieving Cloud Condensation Nuclei Profiles From Surface Measurements

    Science.gov (United States)

    Ghan, Stephen J.; Rissman, Tracey A.; Ellman, Robert; Ferrare, Richard A.; Turner, David; Flynn, Connor; Wang, Jian; Ogren, John; Hudson, James; Jonsson, Haflidi H.; hide

    2006-01-01

    If the aerosol composition and size distribution below cloud are uniform, the vertical profile of cloud condensation nuclei (CCN) concentration can be retrieved entirely from surface measurements of CCN concentration and particle humidification function and surface-based retrievals of relative humidity and aerosol extinction or backscatter. This provides the potential for long-term measurements of CCN concentrations near cloud base. We have used a combination of aircraft, surface in situ, and surface remote sensing measurements to test various aspects of the retrieval scheme. Our analysis leads us to the following conclusions. The retrieval works better for supersaturations of 0.1% than for 1% because CCN concentrations at 0.1% are controlled by the same particles that control extinction and backscatter. If in situ measurements of extinction are used, the retrieval explains a majority of the CCN variance at high supersaturation for at least two and perhaps five of the eight flights examined. The retrieval of the vertical profile of the humidification factor is not the major limitation of the CCN retrieval scheme. Vertical structure in the aerosol size distribution and composition is the dominant source of error in the CCN retrieval, but this vertical structure is difficult to measure from remote sensing at visible wavelengths.

  10. Temporal expression of extracellular matrix metalloproteinases and tissue plasminogen activator in the development of collateral vessels in the canine model of coronary occlusion.

    Science.gov (United States)

    Tyagi, S C; Kumar, S; Cassatt, S; Parker, J L

    1996-08-01

    Although heart attack is caused by occlusion of a major coronary artery, some patients have occlusion without heart attack because these patients have sufficient collateral circulation to provide an alternate pathway for blood supply to the myocardium at ischemic risk. The growth of new capillary vessels (angiogenesis) and enlargement of preexisting vessels play an important role in the collateral development. We evaluated the hypothesis that extracellular matrix metalloproteinase (MMP) expression is altered in coronary collateral arteries (0.5-1 mm o.d.) isolated from canine hearts 2-4 months after surgical placement of an ameroid occluder around the proximal left circumflex artery (n = 4), during the development of collateral vessels and restructuring new vessels. Histologic studies (hematoxylin and eosin, trichrome, and van Gieson stains) indicated cellular proliferation and increased collagen and elastin content in collateral vessels compared with comparable-sized unoccluded arterial segments of the left anterior descending (LAD) artery. In situ MMP activity of collateral vessels, measured using denatured collagen in the gel matrix, indicated an increase in total MMP activity in the intima of collateral vessels compared with normal LAD vessels. To further identify the type of MMP, tissue homogenates were prepared from collateral and LAD vessels and analyzed by SDS-PAGE zymography. The results suggest induction of gelatinase A and gelatinase B expression in collateral vessels compared with normal LAD tissue, when identical amounts of total protein were loaded onto each lane in the gel. Based on plasminogen-casein zymography, we observed the tissue plasminogen activator level to be increased in collateral vessels. On the basis of immunoblot and mRNA (Northern blot) analyses, we determined that the MMP-1 level was induced in collateral vessels 2 and 4 months after ameroid occlusion. In contrast with MMP-1, the level of TIMP-1 (tissue inhibitor of

  11. Effects of titanium prosthesis, offset and size of field of view on bone mineral density measurements using quantitative computed tomography.

    Science.gov (United States)

    Feng, Z; Ziv, I; Rho, J; Han, S; Fishkin, Z

    2000-05-01

    To estimate the accuracy of quantitative computed tomography (QCT) as a method to measure bone mineral density (BMD) in the vicinity of a titanium prosthesis, we investigated the effects of (1) titanium prosthesis, (2) offset of the longitudinal axis of the bone to be examined from that of the gantry of the CT scanner, (3) size of the field of view (FOV) and (4) the combination of these effects on CT based measurements of mineral density of cortical and cancellous bone specimens. 14 bovine cortical bone parallelepipeds and 14 bovine cancellous bone parallelepipeds were used in this investigation. The bone specimens were scanned with and without a titanium prosthesis, when centered in the gantry of the CT scanner and offset from the axis of the gantry of the CT scanner at a distance of 14 cm. Image data were then reconstructed separately with a FOV of 10 cm and 30 cm. All BMD values taken from CT images obtained under different scanning condition were compared with the BMD values of the corresponding bone parallelepiped obtained under standard condition (centered in the gantry of the CT scanner, 10 cm FOV, without titanium prosthesis). When centered in the gantry of the CT scanner, the mean relative difference of BMD measurements caused by the presence of the titanium prosthesis was less than 1% for both cortical bone and cancellous bone. Size of the FOV had a negligible effect on BMD measurements. Offset at 14 cm, however, caused a significant difference in BMD measurements (p < 0.001). It was concluded that titanium prosthesis did not interfere with BMD measurements of cortical and cancellous bone when both the specimen and prosthesis were centered in the gantry of the CT scanner. However, the effect on BMD measurements of offset at 14 cm combined with the presence of a titanium prosthesis in bone was significant.

  12. Estimation of Body Weight from Body Size Measurements and Body Condition Scores in Dairy Cows

    DEFF Research Database (Denmark)

    Enevoldsen, Carsten; Kristensen, T.

    1997-01-01

    The objective of this study was to evaluate the use of hip height and width, body condition score, and relevant demographic information to predict body weight (BW) of dairy cows. Seven regression models were developed from data from 972 observations of 554 cows. Parity, hip height, hip width......, and body condition score were consistently associated with BW. The coefficients of multiple determination varied from 80 to 89%. The number of significant terms and the parameter estimates of the models differed markedly among groups of cows. Apparently, these differences were due to breed and feeding...... regimen. Results from this study indicate that a reliable model for estimating BW of very different dairy cows maintained in a wide range of environments can be developed using body condition score, demographic information, and measurements of hip height and hip width. However, for management purposes...

  13. Measuring lifting forces in rock climbing: effect of hold size and fingertip structure.

    Science.gov (United States)

    Bourne, Roger; Halaki, Mark; Vanwanseele, Benedicte; Clarke, Jillian

    2011-02-01

    This study investigates the hypothesis that shallow edge lifting force in high-level rock climbers is more strongly related to fingertip soft tissue anatomy than to absolute strength or strength to body mass ratio. Fifteen experienced climbers performed repeated maximal single hand lifting exercises on rectangular sandstone edges of depth 2.8, 4.3, 5.8, 7.3, and 12.5 mm while standing on a force measurement platform. Fingertip soft tissue dimensions were assessed by ultrasound imaging. Shallow edge (2.8 and 4.3 mm) lifting force, in newtons or body mass normalized, was uncorrelated with deep edge (12.5 mm) lifting force (r rock contact area on very shallow edges, and thus increase the limit of force production. The study also confirmed previous assumptions of left/right force symmetry in climbers.

  14. Van Allen Probe Measurements of the Scale Sizes and Detailed Properties of EMIC Waves

    Science.gov (United States)

    Blum, L. W.; Bonnell, J. W.; Agapitov, O. V.; Mozer, F.

    2016-12-01

    Electromagnetic ion cyclotron (EMIC) waves are able to resonate with MeV electrons and cause precipitation loss of radiation belt electrons. EMIC waves can provide a strong source of electron pitch angle diffusion, but the waves are often quite localized - thus the spatial extents of these waves can have a large effect on their overall scattering efficiency. Using measurements from the dual Van Allen Probes, we characterize the spatial and temporal extents of EMIC wave active regions and how these depend on local time, radial distance, and wave properties (e.g. amplitude, frequency). Analysis of the detailed wave properties is also performed; we estimate the active region and coherence scales of EMIC waves and examine nonlinear features and parallel electric fields present in some events. These investigations help determine the nature of EMIC wave-particle interactions and support more accurate quantification of their effects on the outer radiation belt.

  15. BY FRUSTUM CONFINING VESSEL

    Directory of Open Access Journals (Sweden)

    Javad Khazaei

    2016-09-01

    Full Text Available Helical piles are environmentally friendly and economical deep foundations that, due to environmental considerations, are excellent additions to a variety of deep foundation alternatives available to the practitioner. Helical piles performance depends on soil properties, the pile geometry and soil-pile interaction. Helical piles can be a proper alternative in sensitive environmental sites if their bearing capacity is sufficient to support applied loads. The failure capacity of helical piles in this study was measured via an experimental research program that was carried out by Frustum Confining Vessel (FCV. FCV is a frustum chamber by approximately linear increase in vertical and lateral stresses along depth from top to bottom. Due to special geometry and applied bottom pressure, this apparatus is a proper choice to test small model piles which can simulate field stress conditions. Small scale helical piles are made with either single helix or more helixes and installed in fine grained sand with three various densities. Axial loading tests including compression and tension tests were performed to achieve pile ultimate capacity. The results indicate the helical piles behavior depends essentially on pile geometric characteristics, i.e. helix configuration and soil properties. According to the achievements, axial uplift capacity of helical model piles is about equal to usual steel model piles that have the helixes diameter. Helical pile compression bearing capacity is too sufficient to act as a medium pile, thus it can be substituted other piles in special geoenvironmental conditions. The bearing capacity also depends on spacing ratio, S/D, and helixes diameter.

  16. A measurement model for real estate bubble size based on the panel data analysis: An empirical case study

    Science.gov (United States)

    Liu, Fengyun; Liu, Deqiang; Malekian, Reza; Li, Zhixiong; Wang, Deqing

    2017-01-01

    Employing the fundamental value of real estate determined by the economic fundamentals, a measurement model for real estate bubble size is established based on the panel data analysis. Using this model, real estate bubble sizes in various regions in Japan in the late 1980s and in recent China are examined. Two panel models for Japan provide results, which are consistent with the reality in the 1980s where a commercial land price bubble appeared in most area and was much larger than that of residential land. This provides evidence of the reliability of our model, overcoming the limit of existing literature with this method. The same models for housing prices in China at both the provincial and city levels show that contrary to the concern of serious housing price bubble in China, over-valuing in recent China is much smaller than that in 1980s Japan. PMID:28273141

  17. A measurement model for real estate bubble size based on the panel data analysis: An empirical case study.

    Directory of Open Access Journals (Sweden)

    Fengyun Liu

    Full Text Available Employing the fundamental value of real estate determined by the economic fundamentals, a measurement model for real estate bubble size is established based on the panel data analysis. Using this model, real estate bubble sizes in various regions in Japan in the late 1980s and in recent China are examined. Two panel models for Japan provide results, which are consistent with the reality in the 1980s where a commercial land price bubble appeared in most area and was much larger than that of residential land. This provides evidence of the reliability of our model, overcoming the limit of existing literature with this method. The same models for housing prices in China at both the provincial and city levels show that contrary to the concern of serious housing price bubble in China, over-valuing in recent China is much smaller than that in 1980s Japan.

  18. A measurement model for real estate bubble size based on the panel data analysis: An empirical case study.

    Science.gov (United States)

    Liu, Fengyun; Liu, Deqiang; Malekian, Reza; Li, Zhixiong; Wang, Deqing

    2017-01-01

    Employing the fundamental value of real estate determined by the economic fundamentals, a measurement model for real estate bubble size is established based on the panel data analysis. Using this model, real estate bubble sizes in various regions in Japan in the late 1980s and in recent China are examined. Two panel models for Japan provide results, which are consistent with the reality in the 1980s where a commercial land price bubble appeared in most area and was much larger than that of residential land. This provides evidence of the reliability of our model, overcoming the limit of existing literature with this method. The same models for housing prices in China at both the provincial and city levels show that contrary to the concern of serious housing price bubble in China, over-valuing in recent China is much smaller than that in 1980s Japan.

  19. Latitudinal and altitudinal variation of size distribution of stratospheric aerosols inferred from SAGE aerosol extinction coefficient measurements at two wavelengths

    Science.gov (United States)

    Yue, G. K.; Deepak, A.

    1984-01-01

    A method of retrieving aerosol size distribution from the measured extinction of solar radiation at wavelengths of 0.45 microns and 1.0 microns has recently been proposed. This method is utilized to obtain latitudinal and altitudinal variations of size distributions of stratospheric aerosols from the Stratospheric Aerosol and Gas Experiment data for March 1979. Small particles are found in the lower stratosphere of the tropical region, and large particles are found at higher altitudes and latitudes in both hemispheres. Results of this study are consistent with the suggestion that the upper troposphere in tropical regions is a source of condensation nuclei in the stratosphere, and they become mature as they move to higher altitudes and latitude.

  20. Enhancing supply vessel safety

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-07-01

    A supply-vessel bridge installation consists of a navigating bridge and a control position aft, from which operators control the ship when close to rigs or platforms, and operate winches and other loading equipment. The international Convention for Safety of I Ale at Sea (SOLAS) does not regulate the layout, so design varies to a large degree, often causing an imperfect working environment. As for other types of ships, more than half the offshore service vessel accidents at sea are caused by bridge system failures. A majority can be traced back to technical design, and operational errors. The research and development project NAUT-OSV is a response to the offshore industry's safety concerns. Analysis of 24 incidents involving contact or collision between supply vessels and offshore installations owned or operated by Norwegian companies indicated that failures in the bridge system were often the cause.