Sizing the height of discontinuities, their characterisation in planar/ volumetric by phased array technique based on diffracted echoes

International Nuclear Information System (INIS)

Nardoni, G.; Certo, M.; Nardoni, P.; Feroldi, M.; Nardoni, D.; Possenti, L.; Filosi, A.; Quetti, S.

2009-01-01

This report demonstrate and discuss the result of experimental works carried out with the scope to study a procedure for improving the characterization (planar volumetric) and sizing the height of discontinuities detected by ultrasonic computerized systems like TOFD, PHASED ARRAY, C-B SCAN. To comply with code case 2235.9 the acceptance criteria illustrated in Tab 1,2,3 shall be applied. For TOFD the procedure for the calculation of the height is well determined and it is the most accurate with respect to any other ultrasonic technique. For PHASED ARRAY the procedures are on developing path. The aim of the present experimental test is to found criteria for the calculation of the height where Phased Array Technique is used. In addition the research has the scope to identify procedure for the characterization of discontinuities in planar and volumetric. The results of the experimental tests has been demonstrated two important achievements:1) The distance between the diffracted echoes is proportional to the height of the discontinuity;2) The ratio between the amplitude of the diffracted echoes could be considered a good criteria for the characterization of discontinuities in planar or volumetric. (author)

Volumetric breast density affects performance of digital screening mammography

OpenAIRE

Wanders, JO; Holland, K; Veldhuis, WB; Mann, RM; Pijnappel, RM; Peeters, PH; Van Gils, CH; Karssemeijer, N

2016-01-01

PURPOSE: To determine to what extent automatically measured volumetric mammographic density influences screening performance when using digital mammography (DM). METHODS: We collected a consecutive series of 111,898 DM examinations (2003-2011) from one screening unit of the Dutch biennial screening program (age 50-75 years). Volumetric mammographic density was automatically assessed using Volpara. We determined screening performance measures for four density categories comparable to the Ameri...

The Influence of Water and Mineral Oil On Volumetric Losses in a Hydraulic Motor

Directory of Open Access Journals (Sweden)

Śliwiński Pawel

2017-04-01

Full Text Available In this paper volumetric losses in hydraulic motor supplied with water and mineral oil (two liquids having significantly different viscosity and lubricating properties are described and compared. The experimental tests were conducted using an innovative hydraulic satellite motor, that is dedicated to work with different liquids, including water. The sources of leaks in this motor are also characterized and described. On this basis, a mathematical model of volumetric losses and model of effective rotational speed have been developed and presented. The results of calculation of volumetric losses according to the model are compared with the results of experiment. It was found that the difference is not more than 20%. Furthermore, it has been demonstrated that this model well describes in both the volumetric losses in the motor supplied with water and oil. Experimental studies have shown that the volumetric losses in the motor supplied with water are even three times greater than the volumetric losses in the motor supplied with oil. It has been shown, that in a small constant stream of water the speed of the motor is reduced even by half in comparison of speed of motor supplied with the same stream of oil.

Design, Implementation and Characterization of a Quantum-Dot-Based Volumetric Display

Science.gov (United States)

Hirayama, Ryuji; Naruse, Makoto; Nakayama, Hirotaka; Tate, Naoya; Shiraki, Atsushi; Kakue, Takashi; Shimobaba, Tomoyoshi; Ohtsu, Motoichi; Ito, Tomoyoshi

2015-02-01

In this study, we propose and experimentally demonstrate a volumetric display system based on quantum dots (QDs) embedded in a polymer substrate. Unlike conventional volumetric displays, our system does not require electrical wiring; thus, the heretofore unavoidable issue of occlusion is resolved because irradiation by external light supplies the energy to the light-emitting voxels formed by the QDs. By exploiting the intrinsic attributes of the QDs, the system offers ultrahigh definition and a wide range of colours for volumetric displays. In this paper, we discuss the design, implementation and characterization of the proposed volumetric display's first prototype. We developed an 8 × 8 × 8 display comprising two types of QDs. This display provides multicolour three-type two-dimensional patterns when viewed from different angles. The QD-based volumetric display provides a new way to represent images and could be applied in leisure and advertising industries, among others.

Experimental determination of hydrogen content of oil extract from jatropha seeds

International Nuclear Information System (INIS)

Okunade, I.O.; Jonah, S.A.; Omede, M.O.

2010-01-01

The thermal neutron technique was used for the determination of hydrogen content of oil extract from Jatropha seeds. The experimental arrangement consists of a source holder, Am-Be neutron source embedded in paraffin wax and 3 He detector was used to measure reflection coefficient as a function of hydrogen content of various hydrocarbon materials used as calibration standards. The hydrogen content which is an important property of fuel oils was determined for jatropha oil and jatropha-synthetic diesel using their measured values of neutron reflection coefficients and calibration data. The result obtained showed that the hydrogen content of Jatropha oil exceeds that of the synthetic diesel, thus indicating its suitability as a fuel oil for powering diesel engines. The results obtained also indicated that hydrogen content of jatropha-synthetic diesel mixture increases as the volumetric concentration of jatropha oil in the mixture increases, indicating that jatropha oil can serve as a suitable additive to synthetic diesel oil.

Reference volumetric samples of gamma-spectroscopic sources

International Nuclear Information System (INIS)

Taskaev, E.; Taskaeva, M.; Grigorov, T.

1993-01-01

The purpose of this investigation is to determine the requirements for matrices of reference volumetric radiation sources necessary for detector calibration. The first stage of this determination consists in analysing some available organic and nonorganic materials. Different sorts of food, grass, plastics, minerals and building materials have been considered, taking into account the various procedures of their processing (grinding, screening, homogenizing) and their properties (hygroscopy, storage life, resistance to oxidation during gamma sterilization). The procedures of source processing, sample preparation, matrix irradiation and homogenization have been determined. A rotation homogenizing device has been elaborated enabling to homogenize the matrix activity irrespective of the vessel geometry. 33 standard volumetric radioactive sources have been prepared: 14 - on organic matrix and 19 - on nonorganic matrix. (author)

Determination of delta ferrite volumetric fraction in austenitic stainless steel

International Nuclear Information System (INIS)

Almeida Macedo, W.A. de.

1983-01-01

Measurements of delta ferrite volumetric fraction in AISI 304 austenitic stainless steels were done by X-ray diffraction, quantitative metallography (point count) and by means of one specific commercial apparatus whose operational principle is magnetic-inductive: The Ferrite Content Meter 1053 / Institut Dr. Foerster. The results obtained were comparated with point count, the reference method. It was also investigated in these measurements the influence of the martensite induced by mechanical deformation. Determinations by X-ray diffraction, by the ratio between integrated intensities of the ferrite (211) and austenite (311) lines, are in excelent agreement with those taken by point count. One correction curve for the lectures of the commercial equipment in focus was obtained, for the range between zero and 20% of delta ferrite in 18/8 stainless steels. It is demonstrated that, depending on the employed measurement method and surface finishing of the material to be analysed, the presence of martensite produced by mechanical deformation of the austenitic matrix is one problem to be considered. (Author) [pt

Determination of delta ferrite volumetric fraction in austenitic stainless steels

International Nuclear Information System (INIS)

Almeida Macedo, W.A. de.

1983-01-01

Measurements of delta ferrite volumetric fraction in AISI 304 austenitic stainless steels were done by X-ray difraction, quantitative metallography (point count) and by means of one specific commercial apparatus whose operational principle is magnetic-inductive: The Ferrite Content Meter 1053 / Institut Dr. Forster. The results obtained were comparated with point count, the reference method. It was also investigated in these measurements the influence of the martensite induced by mechanical deformation. Determinations by X-ray diffraction, by the ratio between integrated intensities of the ferrite (211) and austenite (311) lines, are in excelent agreement with those taken by point count. One correction curve for the lectures of the commercial equipment in focus was obtained, for the range between zero and 20% of delta ferrite in 18/8 stainless steels. It is demonstrated that, depending on the employed measurement method and surface finishing of the material to be analysed, the presence of martensite produced by mechanical deformation of the austenitic matrix is one problem to be considered. (Author) [pt

Experimental investigation of the liquid volumetric mass transfer coefficient for upward gas-liquid two-phase flow in rectangular microchannels

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X. Y. Ji

2010-12-01

Full Text Available The gas-liquid two-phase mass transfer process in microchannels is complicated due to the special dynamical characteristics. In this work, a novel method was explored to measure the liquid side volumetric mass transfer coefficient kLa. Pressure transducers were utilized to measure the pressure variation of upward gas-liquid two-phase flow in three vertical rectangular microchannels and the liquid side volumetric mass transfer coefficient kLa was calculated through the Pressure-Volume-Temperature correlation of the gas phase. Carbon dioxide-water, carbon dioxide-ethanol and carbon dioxide-n-propanol were used as working fluids, respectively. The dimensions of the microchannels were 40 µm×240 µm (depth×width, 100 µm×800 µm and 100 µm×2000 µm, respectively. Results showed that the channel diameter and the capillary number influence kLa remarkably and that the maximum value of kLa occurs in the annular flow regime. A new correlation of kLa was proposed based on the Sherwood number, Schmidt number and the capillary number. The predicted values of kLa agreed well with the experimental data.

Plant fibre composites - porosity and volumetric interaction

DEFF Research Database (Denmark)

Madsen, Bo; Thygesen, Anders; Lilholt, Hans

2007-01-01

the combination of a high fibre volume fraction, a low porosity and a high composite density is optimal. Experimental data from the literature on volumetric composition and density of four types of plant fibre composites are used to validate the model. It is demonstrated that the model provides a concept......Plant fibre composites contain typically a relative large amount of porosity, which considerably influences properties and performance of the composites. The large porosity must be integrated in the conversion of weight fractions into volume fractions of the fibre and matrix parts. A model...... is presented to predict the porosity as a function of the fibre weight fractions, and to calculate the related fibre and matrix volume fractions, as well as the density of the composite. The model predicts two cases of composite volumetric interaction separated by a transition fibre weight fraction, at which...

Determination of density and volumetric water content of soil at multiple photon energies

Energy Technology Data Exchange (ETDEWEB)

Un, A., E-mail: ademun25@yahoo.co [Department of Physics, Faculty of Science and Arts, Agri Ibrahim Cecen University, 04100 Agri (Turkey); Demir, D.; Sahin, Y. [Department of Physics, Faculty of Science, Atatuerk University, 25240 Erzurum (Turkey)

2011-08-15

Gamma ray transmission methods have been used accurately for the study of the properties of soil for agricultural purposes. In this study, density and volumetric water content of soil are determined by using gamma ray transmission method. To this end, the soil sample was collected from Erzurum, Turkey. The attenuation of strongly collimated monoenergetic gamma beam through the soil sample was measured using a 3x3x1 mm{sup 3} cadmium telluride (CdTe) detector. The radioactive sources used in the experiment were {sup 241}Am, {sup 133}Ba and {sup 137}Cs. The mass attenuation coefficients of dry soil sample were calculated from the transmission measurements. It was observed that gamma ray transmission method in measurement of the soil parameters with the portable CdTe detector has advantages such as practical, inexpensive, non-destructive and fast analysis.

Determination of density and volumetric water content of soil at multiple photon energies

International Nuclear Information System (INIS)

Un, A.; Demir, D.; Sahin, Y.

2011-01-01

Gamma ray transmission methods have been used accurately for the study of the properties of soil for agricultural purposes. In this study, density and volumetric water content of soil are determined by using gamma ray transmission method. To this end, the soil sample was collected from Erzurum, Turkey. The attenuation of strongly collimated monoenergetic gamma beam through the soil sample was measured using a 3x3x1 mm 3 cadmium telluride (CdTe) detector. The radioactive sources used in the experiment were 241 Am, 133 Ba and 137 Cs. The mass attenuation coefficients of dry soil sample were calculated from the transmission measurements. It was observed that gamma ray transmission method in measurement of the soil parameters with the portable CdTe detector has advantages such as practical, inexpensive, non-destructive and fast analysis.

Gravimetric and volumetric determination of the purity of electrolytically refined silver and the produced silver nitrate

Directory of Open Access Journals (Sweden)

Ačanski Marijana M.

2007-01-01

Full Text Available Silver is, along with gold and the platinum-group metals, one of the so called precious metals. Because of its comparative scarcity, brilliant white color, malleability and resistance to atmospheric oxidation, silver has been used in the manufacture of coins and jewelry for a long time. Silver has the highest known electrical and thermal conductivity of all metals and is used in fabricating printed electrical circuits, and also as a coating for electronic conductors. It is also alloyed with other elements such as nickel or palladium for use in electrical contacts. The most useful silver salt is silver nitrate, a caustic chemical reagent, significant as an antiseptic and as a reagent in analytical chemistry. Pure silver nitrate is an intermediate in the industrial preparation of other silver salts, including the colloidal silver compounds used in medicine and the silver halides incorporated into photographic emulsions. Silver halides become increasingly insoluble in the series: AgCl, AgBr, AgI. All silver salts are sensitive to light and are used in photographic coatings on film and paper. The ZORKA-PHARMA company (Sabac, Serbia specializes in the production of pharmaceutical remedies and lab chemicals. One of its products is chemical silver nitrate (argentum-nitricum (l. Silver nitrate is generally produced by dissolving pure electrolytically refined silver in hot 48% nitric acid. Since the purity of silver nitrate, produced in 2002, was not in compliance with the p.a. level of purity, there was doubt that the electrolytically refined silver was pure. The aim of this research was the gravimetric and volumetric determination of the purity of electrolytically refined silver and silver nitrate, produced industrially and in a laboratory. The purity determination was carried out gravimetrically, by the sedimentation of silver(I ions in the form of insoluble silver salts: AgCl, AgBr and Agi, and volumetrically, according to Mohr and Volhardt. The

Optical Addressing of Multi-Colour Photochromic Material Mixture for Volumetric Display

Science.gov (United States)

Hirayama, Ryuji; Shiraki, Atsushi; Naruse, Makoto; Nakamura, Shinichiro; Nakayama, Hirotaka; Kakue, Takashi; Shimobaba, Tomoyoshi; Ito, Tomoyoshi

2016-08-01

This is the first study to demonstrate that colour transformations in the volume of a photochromic material (PM) are induced at the intersections of two control light channels, one controlling PM colouration and the other controlling decolouration. Thus, PM colouration is induced by position selectivity, and therefore, a dynamic volumetric display may be realised using these two control lights. Moreover, a mixture of multiple PM types with different absorption properties exhibits different colours depending on the control light spectrum. Particularly, the spectrum management of the control light allows colour-selective colouration besides position selectivity. Therefore, a PM-based, full-colour volumetric display is realised. We experimentally construct a mixture of two PM types and validate the operating principles of such a volumetric display system. Our system is constructed simply by mixing multiple PM types; therefore, the display hardware structure is extremely simple, and the minimum size of a volume element can be as small as the size of a molecule. Volumetric displays can provide natural three-dimensional (3D) perception; therefore, the potential uses of our system include high-definition 3D visualisation for medical applications, architectural design, human-computer interactions, advertising, and entertainment.

Hologlyphics: volumetric image synthesis performance system

Science.gov (United States)

Funk, Walter

2008-02-01

This paper describes a novel volumetric image synthesis system and artistic technique, which generate moving volumetric images in real-time, integrated with music. The system, called the Hologlyphic Funkalizer, is performance based, wherein the images and sound are controlled by a live performer, for the purposes of entertaining a live audience and creating a performance art form unique to volumetric and autostereoscopic images. While currently configured for a specific parallax barrier display, the Hologlyphic Funkalizer's architecture is completely adaptable to various volumetric and autostereoscopic display technologies. Sound is distributed through a multi-channel audio system; currently a quadraphonic speaker setup is implemented. The system controls volumetric image synthesis, production of music and spatial sound via acoustic analysis and human gestural control, using a dedicated control panel, motion sensors, and multiple musical keyboards. Music can be produced by external acoustic instruments, pre-recorded sounds or custom audio synthesis integrated with the volumetric image synthesis. Aspects of the sound can control the evolution of images and visa versa. Sounds can be associated and interact with images, for example voice synthesis can be combined with an animated volumetric mouth, where nuances of generated speech modulate the mouth's expressiveness. Different images can be sent to up to 4 separate displays. The system applies many novel volumetric special effects, and extends several film and video special effects into the volumetric realm. Extensive and various content has been developed and shown to live audiences by a live performer. Real world applications will be explored, with feedback on the human factors.

Volumetric B1 (+) mapping of the brain at 7T using DREAM.

Science.gov (United States)

Nehrke, Kay; Versluis, Maarten J; Webb, Andrew; Börnert, Peter

2014-01-01

To tailor and optimize the Dual Refocusing Echo Acquisition Mode (DREAM) approach for volumetric B1 (+) mapping of the brain at 7T. A new DREAM echo timing scheme based on the virtual stimulated echo was derived to minimize potential effects of transverse relaxation. Furthermore, the DREAM B1 (+) mapping performance was investigated in simulations and experimentally in phantoms and volunteers for volumetric applications, studying and optimizing the accuracy of the sequence with respect to saturation effects, slice profile imperfections, and T1 and T2 relaxation. Volumetric brain protocols were compiled for different isotropic resolutions (5-2.5 mm) and SENSE factors, and were studied in vivo for different RF drive modes (circular/linear polarization) and the application of dielectric pads. Volumetric B1 (+) maps with good SNR at 2.5 mm isotropic resolution were acquired in about 20 s or less. The specific absorption rate was well below the safety limits for all scans. Mild flow artefacts were observed in the large vessels. Moreover, a slight contrast in the ventricle was observed in the B1 (+) maps, which could be attributed to T1 and T2 relaxation effects. DREAM enables safe, very fast, and robust volumetric B1 (+) mapping of the brain at ultrahigh fields. Copyright © 2013 Wiley Periodicals, Inc.

Study on state equation for hydrogen storage measurement by volumetric method

International Nuclear Information System (INIS)

Dai Wei; Xu Jiajing; Wang Chaoyang; Tang Yongjian

2014-01-01

Volumetric measurement technique is one of the most popular methods for determining the amount of hydrogen storage. A new state equation was established which extended the limitations from the ideal gas state equation, the van der Waals equation and the Gou equation. The new state equation was then employed to describe the p-V-T character of hydrogen and investigate the adsorption quantity of hydrogen storage in resorcin-formaldehyde aerogel under different temperatures and pressures. The new equation was used to describe the density of hydrogen under different temperatures and pressures. The results are in good agreement with the experimental data. The differences arising from various underlying physics were carefully analyzed. (authors)

Volumetric runoff coefficients for experimental rural catchments in the Iberian Peninsula

Science.gov (United States)

Taguas, Encarnación V.; Molina, Cecilio; Nadal-Romero, Estela; Ayuso, José L.; Casalí, Javier; Cid, Patricio; Dafonte, Jorge; Duarte, Antonio C.; Farguell, Joaquim; Giménez, Rafael; Giráldez, Juan V.; Gómez, Helena; Gómez, Jose A.; González-Hidalgo, J. Carlos; Keizer, J. Jacob; Lucía, Ana; Mateos, Luciano; Rodríguez-Blanco, M. Luz; Schnabel, Sussane; Serrano-Muela, M. Pilar

2015-04-01

crucial for designing appropriate decision making tools for water management. REFERENCES Chow V.T., Maidment D.R. and Mays, L.W. 1988. Applied Hydrology. MCGraw Hill, Nueva York. Dhakal, N., Fang, X., Cleveland, T., Thompson, D., Asquith, W., and Marzen, L. (2012). "Estimation of Volumetric Runoff Coefficients for Texas Watersheds Using Land-Use and Rainfall-Runoff Data." Journal of Irrigation and Drainage Engineering, 1(2012):43-54. Schaake JC, Geyer JC,Knapp JW. 1967. Experimental examination of the rational method. J. Hydr.Div. 93(6),353-70

Rapid volumetric imaging with Bessel-Beam three-photon microscopy

Science.gov (United States)

Chen, Bingying; Huang, Xiaoshuai; Gou, Dongzhou; Zeng, Jianzhi; Chen, Guoqing; Pang, Meijun; Hu, Yanhui; Zhao, Zhe; Zhang, Yunfeng; Zhou, Zhuan; Wu, Haitao; Cheng, Heping; Zhang, Zhigang; Xu, Chris; Li, Yulong; Chen, Liangyi; Wang, Aimin

2018-01-01

Owing to its tissue-penetration ability, multi-photon fluorescence microscopy allows for the high-resolution, non-invasive imaging of deep tissue in vivo; the recently developed three-photon microscopy (3PM) has extended the depth of high-resolution, non-invasive functional imaging of mouse brains to beyond 1.0 mm. However, the low repetition rate of femtosecond lasers that are normally used in 3PM limits the temporal resolution of point-scanning three-photon microscopy. To increase the volumetric imaging speed of 3PM, we propose a combination of an axially elongated needle-like Bessel-beam with three-photon excitation (3PE) to image biological samples with an extended depth of focus. We demonstrate the higher signal-to-background ratio (SBR) of the Bessel-beam 3PM compared to the two-photon version both theoretically and experimentally. Finally, we perform simultaneous calcium imaging of brain regions at different axial locations in live fruit flies and rapid volumetric imaging of neuronal structures in live mouse brains. These results highlight the unique advantage of conducting rapid volumetric imaging with a high SBR in the deep brain in vivo using scanning Bessel-3PM.

Volumetric polymerization shrinkage of contemporary composite resins

Directory of Open Access Journals (Sweden)

Halim Nagem Filho

2007-10-01

Full Text Available The polymerization shrinkage of composite resins may affect negatively the clinical outcome of the restoration. Extensive research has been carried out to develop new formulations of composite resins in order to provide good handling characteristics and some dimensional stability during polymerization. The purpose of this study was to analyze, in vitro, the magnitude of the volumetric polymerization shrinkage of 7 contemporary composite resins (Definite, Suprafill, SureFil, Filtek Z250, Fill Magic, Alert, and Solitaire to determine whether there are differences among these materials. The tests were conducted with precision of 0.1 mg. The volumetric shrinkage was measured by hydrostatic weighing before and after polymerization and calculated by known mathematical equations. One-way ANOVA (a or = 0.05 was used to determine statistically significant differences in volumetric shrinkage among the tested composite resins. Suprafill (1.87±0.01 and Definite (1.89±0.01 shrank significantly less than the other composite resins. SureFil (2.01±0.06, Filtek Z250 (1.99±0.03, and Fill Magic (2.02±0.02 presented intermediate levels of polymerization shrinkage. Alert and Solitaire presented the highest degree of polymerization shrinkage. Knowing the polymerization shrinkage rates of the commercially available composite resins, the dentist would be able to choose between using composite resins with lower polymerization shrinkage rates or adopting technical or operational procedures to minimize the adverse effects deriving from resin contraction during light-activation.

Visualization and computer graphics on isotropically emissive volumetric displays.

Science.gov (United States)

Mora, Benjamin; Maciejewski, Ross; Chen, Min; Ebert, David S

2009-01-01

The availability of commodity volumetric displays provides ordinary users with a new means of visualizing 3D data. Many of these displays are in the class of isotropically emissive light devices, which are designed to directly illuminate voxels in a 3D frame buffer, producing X-ray-like visualizations. While this technology can offer intuitive insight into a 3D object, the visualizations are perceptually different from what a computer graphics or visualization system would render on a 2D screen. This paper formalizes rendering on isotropically emissive displays and introduces a novel technique that emulates traditional rendering effects on isotropically emissive volumetric displays, delivering results that are much closer to what is traditionally rendered on regular 2D screens. Such a technique can significantly broaden the capability and usage of isotropically emissive volumetric displays. Our method takes a 3D dataset or object as the input, creates an intermediate light field, and outputs a special 3D volume dataset called a lumi-volume. This lumi-volume encodes approximated rendering effects in a form suitable for display with accumulative integrals along unobtrusive rays. When a lumi-volume is fed directly into an isotropically emissive volumetric display, it creates a 3D visualization with surface shading effects that are familiar to the users. The key to this technique is an algorithm for creating a 3D lumi-volume from a 4D light field. In this paper, we discuss a number of technical issues, including transparency effects due to the dimension reduction and sampling rates for light fields and lumi-volumes. We show the effectiveness and usability of this technique with a selection of experimental results captured from an isotropically emissive volumetric display, and we demonstrate its potential capability and scalability with computer-simulated high-resolution results.

AISLE: an automatic volumetric segmentation method for the study of lung allometry.

Science.gov (United States)

Ren, Hongliang; Kazanzides, Peter

2011-01-01

We developed a fully automatic segmentation method for volumetric CT (computer tomography) datasets to support construction of a statistical atlas for the study of allometric laws of the lung. The proposed segmentation method, AISLE (Automated ITK-Snap based on Level-set), is based on the level-set implementation from an existing semi-automatic segmentation program, ITK-Snap. AISLE can segment the lung field without human interaction and provide intermediate graphical results as desired. The preliminary experimental results show that the proposed method can achieve accurate segmentation, in terms of volumetric overlap metric, by comparing with the ground-truth segmentation performed by a radiologist.

Volumetric composition of nanocomposites

DEFF Research Database (Denmark)

Madsen, Bo; Lilholt, Hans; Mannila, Juha

2015-01-01

is presented, using cellulose/epoxy and aluminosilicate/polylactate nanocomposites as case materials. The buoyancy method is used for the accurate measurements of materials density. The accuracy of the method is determined to be high, allowing the measured nanocomposite densities to be reported with 5...... significant figures. The plotting of the measured nanocomposite density as a function of the nanofibre weight content is shown to be a first good approach of assessing the porosity content of the materials. The known gravimetric composition of the nanocomposites is converted into a volumetric composition...

Adaptive controller for volumetric display of neuroimaging studies

Science.gov (United States)

Bleiberg, Ben; Senseney, Justin; Caban, Jesus

2014-03-01

Volumetric display of medical images is an increasingly relevant method for examining an imaging acquisition as the prevalence of thin-slice imaging increases in clinical studies. Current mouse and keyboard implementations for volumetric control provide neither the sensitivity nor specificity required to manipulate a volumetric display for efficient reading in a clinical setting. Solutions to efficient volumetric manipulation provide more sensitivity by removing the binary nature of actions controlled by keyboard clicks, but specificity is lost because a single action may change display in several directions. When specificity is then further addressed by re-implementing hardware binary functions through the introduction of mode control, the result is a cumbersome interface that fails to achieve the revolutionary benefit required for adoption of a new technology. We address the specificity versus sensitivity problem of volumetric interfaces by providing adaptive positional awareness to the volumetric control device by manipulating communication between hardware driver and existing software methods for volumetric display of medical images. This creates a tethered effect for volumetric display, providing a smooth interface that improves on existing hardware approaches to volumetric scene manipulation.

Correlation of volumetric mismatch and mismatch of Alberta Stroke program Early CT scores on CT perfusion maps

International Nuclear Information System (INIS)

Lin, Ke; Rapalino, Otto; Lee, Benjamin; Do, Kinh G.; Sussmann, Amado R.; Pramanik, Bidyut K.; Law, Meng

2009-01-01

We aimed to determine if volumetric mismatch between tissue at risk and tissue destined to infarct on computed tomography perfusion (CTP) can be described by the mismatch of Alberta Stroke Program Early CT Score (ASPECTS). Forty patients with nonlacunar middle cerebral artery infarct 6 s and <2.0 mL per 100 g, respectively. Two other raters assigned ASPECTS to the same MTT and CBV maps while blinded to the volumetric data. Volumetric mismatch was deemed present if ≥20%. ASPECTS mismatch (=CBV ASPECTS - MTT ASPECTS) was deemed present if ≥1. Correlation between the two types of mismatches was assessed by Spearman's coefficient (ρ). ROC curve analyses were performed to determine the optimal ASPECTS mismatch cut point for volumetric mismatch ≥20%, ≥50%, ≥100%, and ≥150%. Median volumetric mismatch was 130% (range 10.9-2,031%) with 31 (77.5%) being ≥20%. Median ASPECTS mismatch was 2 (range 0-6) with 26 (65%) being ≥1. ASPECTS mismatch correlated strongly with volumetric mismatch with ρ = 0.763 [95% CI 0.585-0.870], p < 0.0001. Sensitivity and specificity for volumetric mismatch ≥20% was 83.9% [95% CI 65.5-93.5] and 100% [95% CI 65.9-100], respectively, using ASPECTS mismatch ≥1. Volumetric mismatch ≥50%, ≥100%, and ≥150% were optimally identified using ASPECTS mismatch ≥1, ≥2, and ≥2, respectively. On CTP, ASPECTS mismatch showed strong correlation to volumetric mismatch. ASPECTS mismatch ≥1 was the optimal cut point for volumetric mismatch ≥20%. (orig.)

Force Field Benchmark of the TraPPE_UA for Polar Liquids: Density, Heat of Vaporization, Dielectric Constant, Surface Tension, Volumetric Expansion Coefficient, and Isothermal Compressibility.

Science.gov (United States)

Núñez-Rojas, Edgar; Aguilar-Pineda, Jorge Alberto; Pérez de la Luz, Alexander; de Jesús González, Edith Nadir; Alejandre, José

2018-02-08

The transferable potential for a phase equilibria force field in its united-atom version, TraPPE_UA, is evaluated for 41 polar liquids that include alcohols, thiols, ethers, sulfides, aldehydes, ketones, and esters to determine its ability to reproduce experimental properties that were not included in the parametrization procedure. The intermolecular force field parameters for pure components were fit to reproduce experimental boiling temperature, vapor-liquid coexisting densities, and critical point (temperature, density, and pressure) using Monte Carlo simulations in different ensembles. The properties calculated in this work are liquid density, heat of vaporization, dielectric constant, surface tension, volumetric expansion coefficient, and isothermal compressibility. Molecular dynamics simulations were performed in the gas and liquid phases, and also at the liquid-vapor interface. We found that relative error between calculated and experimental data is 1.2% for density, 6% for heat of vaporization, and 6.2% for surface tension, in good agreement with the experimental data. The dielectric constant is systematically underestimated, and the relative error is 37%. Evaluating the performance of the force field to reproduce the volumetric expansion coefficient and isothermal compressibility requires more experimental data.

Gradients estimation from random points with volumetric tensor in turbulence

Science.gov (United States)

Watanabe, Tomoaki; Nagata, Koji

2017-12-01

We present an estimation method of fully-resolved/coarse-grained gradients from randomly distributed points in turbulence. The method is based on a linear approximation of spatial gradients expressed with the volumetric tensor, which is a 3 × 3 matrix determined by a geometric distribution of the points. The coarse grained gradient can be considered as a low pass filtered gradient, whose cutoff is estimated with the eigenvalues of the volumetric tensor. The present method, the volumetric tensor approximation, is tested for velocity and passive scalar gradients in incompressible planar jet and mixing layer. Comparison with a finite difference approximation on a Cartesian grid shows that the volumetric tensor approximation computes the coarse grained gradients fairly well at a moderate computational cost under various conditions of spatial distributions of points. We also show that imposing the solenoidal condition improves the accuracy of the present method for solenoidal vectors, such as a velocity vector in incompressible flows, especially when the number of the points is not large. The volumetric tensor approximation with 4 points poorly estimates the gradient because of anisotropic distribution of the points. Increasing the number of points from 4 significantly improves the accuracy. Although the coarse grained gradient changes with the cutoff length, the volumetric tensor approximation yields the coarse grained gradient whose magnitude is close to the one obtained by the finite difference. We also show that the velocity gradient estimated with the present method well captures the turbulence characteristics such as local flow topology, amplification of enstrophy and strain, and energy transfer across scales.

A volumetric flow sensor for automotive injection systems

International Nuclear Information System (INIS)

Schmid, U; Krötz, G; Schmitt-Landsiedel, D

2008-01-01

For further optimization of the automotive power train of diesel engines, advanced combustion processes require a highly flexible injection system, provided e.g. by the common rail (CR) injection technique. In the past, the feasibility to implement injection nozzle volumetric flow sensors based on the thermo-resistive measurement principle has been demonstrated up to injection pressures of 135 MPa (1350 bar). To evaluate the transient behaviour of the system-integrated flow sensors as well as an injection amount indicator used as a reference method, hydraulic simulations on the system level are performed for a CR injection system. Experimentally determined injection timings were found to be in good agreement with calculated values, especially for the novel sensing element which is directly implemented into the hydraulic system. For the first time pressure oscillations occurring after termination of the injection pulse, predicted theoretically, could be verified directly in the nozzle. In addition, the injected amount of fuel is monitored with the highest resolution ever reported in the literature

A volumetric flow sensor for automotive injection systems

Science.gov (United States)

Schmid, U.; Krötz, G.; Schmitt-Landsiedel, D.

2008-04-01

For further optimization of the automotive power train of diesel engines, advanced combustion processes require a highly flexible injection system, provided e.g. by the common rail (CR) injection technique. In the past, the feasibility to implement injection nozzle volumetric flow sensors based on the thermo-resistive measurement principle has been demonstrated up to injection pressures of 135 MPa (1350 bar). To evaluate the transient behaviour of the system-integrated flow sensors as well as an injection amount indicator used as a reference method, hydraulic simulations on the system level are performed for a CR injection system. Experimentally determined injection timings were found to be in good agreement with calculated values, especially for the novel sensing element which is directly implemented into the hydraulic system. For the first time pressure oscillations occurring after termination of the injection pulse, predicted theoretically, could be verified directly in the nozzle. In addition, the injected amount of fuel is monitored with the highest resolution ever reported in the literature.

Development of a volumetric Analysis method to determine uranium in the loaded phosphoric acid and the loaded organic phase (DEHPA/TOPO)

International Nuclear Information System (INIS)

Shlewit, H.; Koudsi, Y.

2003-01-01

Rapid and reliable volumetric analysis method has been developed to determine uranium, on line, at uranium extraction unit from wet-process phosphoric acid, in aqueous and organic phases. This process enable up 300 mg of uranium to be determined in the presence of nitric acid, in a sample volume of up to at least 10 ml. The volume of the sample, the amounts of reagents added, the temperature of the reagents and the standing time of various stages were investigated to ensure that the conditions selected for the final procedure were reasonably non-critical

Hierarchical anatomical brain networks for MCI prediction: revisiting volumetric measures.

Directory of Open Access Journals (Sweden)

Luping Zhou

Full Text Available Owning to its clinical accessibility, T1-weighted MRI (Magnetic Resonance Imaging has been extensively studied in the past decades for prediction of Alzheimer's disease (AD and mild cognitive impairment (MCI. The volumes of gray matter (GM, white matter (WM and cerebrospinal fluid (CSF are the most commonly used measurements, resulting in many successful applications. It has been widely observed that disease-induced structural changes may not occur at isolated spots, but in several inter-related regions. Therefore, for better characterization of brain pathology, we propose in this paper a means to extract inter-regional correlation based features from local volumetric measurements. Specifically, our approach involves constructing an anatomical brain network for each subject, with each node representing a Region of Interest (ROI and each edge representing Pearson correlation of tissue volumetric measurements between ROI pairs. As second order volumetric measurements, network features are more descriptive but also more sensitive to noise. To overcome this limitation, a hierarchy of ROIs is used to suppress noise at different scales. Pairwise interactions are considered not only for ROIs with the same scale in the same layer of the hierarchy, but also for ROIs across different scales in different layers. To address the high dimensionality problem resulting from the large number of network features, a supervised dimensionality reduction method is further employed to embed a selected subset of features into a low dimensional feature space, while at the same time preserving discriminative information. We demonstrate with experimental results the efficacy of this embedding strategy in comparison with some other commonly used approaches. In addition, although the proposed method can be easily generalized to incorporate other metrics of regional similarities, the benefits of using Pearson correlation in our application are reinforced by the experimental

In Vivo Real Time Volumetric Synthetic Aperture Ultrasound Imaging

DEFF Research Database (Denmark)

Bouzari, Hamed; Rasmussen, Morten Fischer; Brandt, Andreas Hjelm

2015-01-01

Synthetic aperture (SA) imaging can be used to achieve real-time volumetric ultrasound imaging using 2-D array transducers. The sensitivity of SA imaging is improved by maximizing the acoustic output, but one must consider the limitations of an ultrasound system, both technical and biological....... This paper investigates the in vivo applicability and sensitivity of volumetric SA imaging. Utilizing the transmit events to generate a set of virtual point sources, a frame rate of 25 Hz for a 90° x 90° field-of-view was achieved. Data were obtained using a 3.5 MHz 32 x 32 elements 2-D phased array...... transducer connected to the experimental scanner (SARUS). Proper scaling is applied to the excitation signal such that intensity levels are in compliance with the U.S. Food and Drug Administration regulations for in vivo ultrasound imaging. The measured Mechanical Index and spatial-peak- temporal...

Microfluidic volumetric flow determination using optical coherence tomography speckle: An autocorrelation approach

Energy Technology Data Exchange (ETDEWEB)

De Pretto, Lucas R., E-mail: lucas.de.pretto@usp.br; Nogueira, Gesse E. C.; Freitas, Anderson Z. [Instituto de Pesquisas Energéticas e Nucleares, IPEN–CNEN/SP, Avenida Lineu Prestes, 2242, 05508-000 São Paulo (Brazil)

2016-04-28

Functional modalities of Optical Coherence Tomography (OCT) based on speckle analysis are emerging in the literature. We propose a simple approach to the autocorrelation of OCT signal to enable volumetric flow rate differentiation, based on decorrelation time. Our results show that this technique could distinguish flows separated by 3 μl/min, limited by the acquisition speed of the system. We further perform a B-scan of gradient flow inside a microchannel, enabling the visualization of the drag effect on the walls.

Determination of iodide by volumetric titration in support of the oil eletrolabeling with {sup 123}I

Energy Technology Data Exchange (ETDEWEB)

Kenup-Cantuaria, Hericka O.H.; Brandao, Luis E.B., E-mail: hkenup@ien.gov.br, E-mail: brandao@ien.gov.br [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Silva, Ademir X., E-mail: ademir@nuclear.ufrj.br [Coordenacao dos Programas de Pos-Graduacao em Engenharia (PEN/COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Nuclear

2015-07-01

The accuracy in measuring flow rate in pipelines is essential task to control various technical parameters in an industrial plant in oil industry and its derivatives. For this reason, it becomes increasingly widespread the uses of organic molecules labeled with radioactive isotopes mainly because of the wide possibility in use of different radioisotopes also due to the new labeling techniques. This paper presents a study to develop an electrochemical technique for oil labeling with iodine -123 and to determine the yield of production by measuring the concentration of iodide (I{sup -}) during this process. The volumetric titration technique was applied as a basis for quantitative and qualitative measures to monitor the labeling process. The results indicate the technical proposal as a viable alternative for monitoring electro labeling process of lubricating oils with iodine -123. (author)

Reducing uncertainties in volumetric image based deformable organ registration

International Nuclear Information System (INIS)

Liang, J.; Yan, D.

2003-01-01

Applying volumetric image feedback in radiotherapy requires image based deformable organ registration. The foundation of this registration is the ability of tracking subvolume displacement in organs of interest. Subvolume displacement can be calculated by applying biomechanics model and the finite element method to human organs manifested on the multiple volumetric images. The calculation accuracy, however, is highly dependent on the determination of the corresponding organ boundary points. Lacking sufficient information for such determination, uncertainties are inevitable--thus diminishing the registration accuracy. In this paper, a method of consuming energy minimization was developed to reduce these uncertainties. Starting from an initial selection of organ boundary point correspondence on volumetric image sets, the subvolume displacement and stress distribution of the whole organ are calculated and the consumed energy due to the subvolume displacements is computed accordingly. The corresponding positions of the initially selected boundary points are then iteratively optimized to minimize the consuming energy under geometry and stress constraints. In this study, a rectal wall delineated from patient CT image was artificially deformed using a computer simulation and utilized to test the optimization. Subvolume displacements calculated based on the optimized boundary point correspondence were compared to the true displacements, and the calculation accuracy was thereby evaluated. Results demonstrate that a significant improvement on the accuracy of the deformable organ registration can be achieved by applying the consuming energy minimization in the organ deformation calculation

Volumetric and viscometric properties of binary and ternary mixtures of 1-butyl-3-methylimidazolium tetrafluoroborate, monoethanolamine and water

International Nuclear Information System (INIS)

Yin, Yaran; Zhu, Chunying; Ma, Youguang

2016-01-01

Highlights: • Densities and viscosities of [Bmim][BF 4 ] + MEA + H 2 O solutions were measured. • Volumetric and viscometric properties were deduced from experimental results. • Intermolecular interactions were analysed by volumetric and viscometric properties. - Abstract: Densities and viscosities of binary {[Bmim][BF 4 ] + H 2 O}, {[Bmim][BF 4 ] + MEA}, (MEA + H 2 O) and ternary mixtures {[Bmim][BF 4 ] + MEA + H 2 O} were measured at T = (293.15–333.15) K. The volumetric and viscometric properties, such as excess molar volume V E , viscosity deviation Δη, and excess Gibbs energy of activation of viscous flow ΔG ∗E for all mixtures, and apparent molar volume, excess partial molar volume and Grunberg-Nissan interaction parameter G 12 for binary mixtures, were deduced from experimental results, and the intermolecular interactions in solutions were also analysed. The excess molar volumes were correlated using the Redlich-Kister polynomial equation for binary mixtures, and Singh et al. equation for the ternary mixture with corresponding binary parameters. The viscosities of binary and ternary solutions were respectively fitted by Jouyban-Acree equation and its extended equation at each measurement temperature, the correlated values are in good agreement with the corresponding experimental data.

Volumetric CT-images improve testing of radiological image interpretation skills

Energy Technology Data Exchange (ETDEWEB)

Ravesloot, Cécile J., E-mail: C.J.Ravesloot@umcutrecht.nl [Radiology Department at University Medical Center Utrecht, Heidelberglaan 100, 3508 GA Utrecht, Room E01.132 (Netherlands); Schaaf, Marieke F. van der, E-mail: M.F.vanderSchaaf@uu.nl [Department of Pedagogical and Educational Sciences at Utrecht University, Heidelberglaan 1, 3584 CS Utrecht (Netherlands); Schaik, Jan P.J. van, E-mail: J.P.J.vanSchaik@umcutrecht.nl [Radiology Department at University Medical Center Utrecht, Heidelberglaan 100, 3508 GA Utrecht, Room E01.132 (Netherlands); Cate, Olle Th.J. ten, E-mail: T.J.tenCate@umcutrecht.nl [Center for Research and Development of Education at University Medical Center Utrecht, Heidelberglaan 100, 3508 GA Utrecht (Netherlands); Gijp, Anouk van der, E-mail: A.vanderGijp-2@umcutrecht.nl [Radiology Department at University Medical Center Utrecht, Heidelberglaan 100, 3508 GA Utrecht, Room E01.132 (Netherlands); Mol, Christian P., E-mail: C.Mol@umcutrecht.nl [Image Sciences Institute at University Medical Center Utrecht, Heidelberglaan 100, 3508 GA Utrecht (Netherlands); Vincken, Koen L., E-mail: K.Vincken@umcutrecht.nl [Image Sciences Institute at University Medical Center Utrecht, Heidelberglaan 100, 3508 GA Utrecht (Netherlands)

2015-05-15

Rationale and objectives: Current radiology practice increasingly involves interpretation of volumetric data sets. In contrast, most radiology tests still contain only 2D images. We introduced a new testing tool that allows for stack viewing of volumetric images in our undergraduate radiology program. We hypothesized that tests with volumetric CT-images enhance test quality, in comparison with traditional completely 2D image-based tests, because they might better reflect required skills for clinical practice. Materials and methods: Two groups of medical students (n = 139; n = 143), trained with 2D and volumetric CT-images, took a digital radiology test in two versions (A and B), each containing both 2D and volumetric CT-image questions. In a questionnaire, they were asked to comment on the representativeness for clinical practice, difficulty and user-friendliness of the test questions and testing program. Students’ test scores and reliabilities, measured with Cronbach's alpha, of 2D and volumetric CT-image tests were compared. Results: Estimated reliabilities (Cronbach's alphas) were higher for volumetric CT-image scores (version A: .51 and version B: .54), than for 2D CT-image scores (version A: .24 and version B: .37). Participants found volumetric CT-image tests more representative of clinical practice, and considered them to be less difficult than volumetric CT-image questions. However, in one version (A), volumetric CT-image scores (M 80.9, SD 14.8) were significantly lower than 2D CT-image scores (M 88.4, SD 10.4) (p < .001). The volumetric CT-image testing program was considered user-friendly. Conclusion: This study shows that volumetric image questions can be successfully integrated in students’ radiology testing. Results suggests that the inclusion of volumetric CT-images might improve the quality of radiology tests by positively impacting perceived representativeness for clinical practice and increasing reliability of the test.

VOLUMETRIC LEAK DETECTION IN LARGE UNDERGROUND STORAGE TANKS - VOLUME I

Science.gov (United States)

A set of experiments was conducted to determine whether volumetric leak detection system presently used to test underground storage tanks (USTs) up to 38,000 L (10,000 gal) in capacity could meet EPA's regulatory standards for tank tightness and automatic tank gauging systems whe...

Evaluation of the effect of temperature, concentration and volumetric flow in the hydrolysis of sucrose by an immobilized invertase in a spherical reactor

International Nuclear Information System (INIS)

Zamora Leiton, Maria Monserrath; Molina Cordoba, Manuel; Chacon Valle, Gerardo

2011-01-01

The effect of the volumetric flow, the temperature and the initial concentration of sucrose in the reaction of hydrolysis of sucrose by immobilized invertase were evaluated in the laboratory. Invertase was immobilized in 20 g of support of mesh size between 120 and 140. The maximum quantity of immobilized invertase obtained has been 0,130 mg/g of support at 220 min. The first experimental stage has consisted in the evaluation of the effect of the initial concentration of sucrose (1,0 and 1,5 mol/L), the volumetric flow (3,0 mL/min and 4,0 mL/min) and the temperature (45 degrees C and 50 degrees C). The effect of the above three variable has been statistically significant. The conversion has been favorable for a concentration of sucrose 1,0 mol/L, a volumetric flow of 3 mL/min and a temperature of 50 degrees C. The maximum conversion obtained has been 95,4 %. The second experimental stage has analyzed the effect of the initial concentration of sucrose (0,75 and 1,0 mol/L), the volumetric flow (2,5 mL/min and 3,0 mL/min) and the temperature (50 degrees C and 55 degrees C). The variable of volumetric flow and the interaction concentration of sucrose - temperature are found statistically significant. The conversion has been favorable for a volumetric flow of 2,5 mL/min, and it has been preferable to work at a temperature of 50 degrees C with an initial concentration of sucrose of 1,0 mol/L. The maximum conversion has been 94,8 %. The effect of the concentration was analyzed in the last experimental stage, it was found that the maximum conversion percentage was 95,0 % for a concentration of 1,1 mol/L, for a temperature of 50 degrees C and for a volumetric flow of 2,5 mL/min. (author) [es

Comparative Study of the Volumetric Methods Calculation Using GNSS Measurements

Science.gov (United States)

Şmuleac, Adrian; Nemeş, Iacob; Alina Creţan, Ioana; Sorina Nemeş, Nicoleta; Şmuleac, Laura

2017-10-01

This paper aims to achieve volumetric calculations for different mineral aggregates using different methods of analysis and also comparison of results. To achieve these comparative studies and presentation were chosen two software licensed, namely TopoLT 11.2 and Surfer 13. TopoLT program is a program dedicated to the development of topographic and cadastral plans. 3D terrain model, level courves and calculation of cut and fill volumes, including georeferencing of images. The program Surfer 13 is produced by Golden Software, in 1983 and is active mainly used in various fields such as agriculture, construction, geophysical, geotechnical engineering, GIS, water resources and others. It is also able to achieve GRID terrain model, to achieve the density maps using the method of isolines, volumetric calculations, 3D maps. Also, it can read different file types, including SHP, DXF and XLSX. In these paper it is presented a comparison in terms of achieving volumetric calculations using TopoLT program by two methods: a method where we choose a 3D model both for surface as well as below the top surface and a 3D model in which we choose a 3D terrain model for the bottom surface and another 3D model for the top surface. The comparison of the two variants will be made with data obtained from the realization of volumetric calculations with the program Surfer 13 generating GRID terrain model. The topographical measurements were performed with equipment from Leica GPS 1200 Series. Measurements were made using Romanian position determination system - ROMPOS which ensures accurate positioning of reference and coordinates ETRS through the National Network of GNSS Permanent Stations. GPS data processing was performed with the program Leica Geo Combined Office. For the volumetric calculating the GPS used point are in 1970 stereographic projection system and for the altitude the reference is 1975 the Black Sea projection system.

Experimental investigation of convective heat transfer augmentation for car radiator using ZnO–water nanofluids

International Nuclear Information System (INIS)

Ali, Hafiz Muhammad; Ali, Hassan; Liaquat, Hassan; Bin Maqsood, Hafiz Talha; Nadir, Malik Ahmed

2015-01-01

New experimental data are reported for water based nanofluids to enhance the heat transfer performance of a car radiator. ZnO nanoparticles have been added into base fluid in different volumetric concentrations (0.01%, 0.08%, 0.2% and 0.3%). The effect of these volumetric concentrations on the heat transfer performance for car radiator is determined experimentally. Fluid flow rate has been varied in a range of 7–11 LPM (liter per minute) (corresponding Reynolds number range was 17,500–27,600). Nanofluids showed heat transfer enhancement compared to the base fluid for all concentrations tested. The best heat transfer enhancement up to 46% was found compared to base fluid at 0.2% volumetric concentration. A further increase in volumetric concentration to 0.3% has shown a decrease in heat transfer enhancement compared to 0.2% volumetric concentration. Fluid inlet temperature was kept in a range of 45–55 °C. An increase in fluid inlet temperature from 45 °C to 55 °C showed increase in heat transfer rate up to 4%. - Highlights: • ZnO–water nanofluids were used for car radiator thermal enhancement. • Heat transfer enhancement up to 46% was achieved comparing pure water. • 0.2% vol. concentration of ZnO found to be optimum for heat transfer. • Heat transfer was found weakly dependant on the fluid inlet temperature

Numerical and experimental determination of surface temperature and moisture evolution in a field soil

Science.gov (United States)

Akinyemi, Olukayode D.; Mendes, Nathan

2007-03-01

Knowledge about the dynamics of soil moisture and heat, especially at the surface, provides important insights into the physical processes governing their interactions with the atmosphere, thereby improving the understanding of patterns of climate dynamics. In this context the paper presents the numerical and field experimental results of temperature and moisture evolution, which were measured on the surface of a sandy soil at Abeokuta, south-western Nigeria. An unconditionally stable numerical method was used, which linearizes the vapour concentration driving-potential term giving the moisture exchanged at the boundaries in terms of temperature and moisture content, and simultaneously solves the governing equations for each time step. The model avoids stability problems and limitations to low moisture contents and the usual assumption of constant thermal conductivity. Instantaneous temperature measurements were made at the surface using a thermocouple, while the gravimetric method was employed to determine the volumetric water contents at some specific hours of the experimental period. The observed experimental data compared fairly well with the predicted values, with both having correlation coefficients greater than 0.9 and consequently following a common diurnal trend. The sensitivity of the model was very high to the choice of simulation parameters, especially grid size refinement and time step. While the model underestimated the soil moisture content at 6 a.m. and 10 p.m., the measured temperatures were however overestimated. When compared to moisture content, average errors for temperature were low resulting in a minimal absolute difference in amplitude of 0.81 °C.

Volumetric properties of ammonium nitrate in N,N-dimethylformamide

International Nuclear Information System (INIS)

Vranes, Milan; Dozic, Sanja; Djeric, Vesna; Gadzuric, Slobodan

2012-01-01

Highlights: ► We observed interactions and changes in the solution using volumetric properties. ► The greatest influence on the solvent–solvent interactions has temperature. ► The smallest influence temperature has on the ion–ion interactions. ► Temperature has no influence on concentrated systems and partially solvated melts. - Abstract: The densities of the ammonium nitrate in N,N-dimethylformamide (DMF) mixtures were measured at T = (308.15 to 348.15) K for different ammonium nitrate molalities in the range from (0 to 6.8404) mol·kg −1 . From the obtained density data, volumetric properties (apparent molar volumes and partial molar volumes) have been evaluated and discussed in the term of respective ionic and dipole interactions. From the apparent molar volume, determined at various temperatures, the apparent molar expansibility and the coefficients of thermal expansion were also calculated.

Experimental analysis of volumetric wear behavioural and mechanical properties study of as cast and 1Hr homogenized Al-25Mg2Si2Cu4Ni alloy at constant load

Science.gov (United States)

Harlapur, M. D.; Mallapur, D. G.; Udupa, K. Rajendra

2018-04-01

In the current study, an experimental analysis of volumetric wear behaviour and mechanical properties of aluminium (Al-25Mg2Si2Cu4Ni) alloy in as cast and 1Hr homogenized with T6 heat treatment is carried out at constant load. Pin-on-disc apparatus was used to carry out sliding wear test. Mechanical properties such as tensile, hardness and compression test on as-cast and 1 hr homogenized samples are measured. Universal testing machine was used to conduct the tensile and compressive test at room temperature. Brinell hardness tester was used to conduct the hardness test. The scanning electron microscope was used to analyze the worn-out wear surfaces. Wear results and mechanical properties shows that 1Hr homogenized Al-25Mg2Si2Cu4Ni alloy samples with T6 treated had better volumetric wear resistance, hardness, tensile and compressive strength as compared to as cast samples.

Determination of volumetric gas-liquid mass transfer coefficient of carbon monoxide in a batch cultivation system using kinetic simulations.

Science.gov (United States)

Jang, Nulee; Yasin, Muhammad; Park, Shinyoung; Lovitt, Robert W; Chang, In Seop

2017-09-01

A mathematical model of microbial kinetics was introduced to predict the overall volumetric gas-liquid mass transfer coefficient (k L a) of carbon monoxide (CO) in a batch cultivation system. The cell concentration (X), acetate concentration (C ace ), headspace gas (N co and [Formula: see text] ), dissolved CO concentration in the fermentation medium (C co ), and mass transfer rate (R) were simulated using a variety of k L a values. The simulated results showed excellent agreement with the experimental data for a k L a of 13/hr. The C co values decreased with increase in cultivation times, whereas the maximum mass transfer rate was achieved at the mid-log phase due to vigorous microbial CO consumption rate higher than R. The model suggested in this study may be applied to a variety of microbial systems involving gaseous substrates. Copyright © 2017 Elsevier Ltd. All rights reserved.

The Effect of Elevation on Volumetric Measurements of the Lower Extremity

Directory of Open Access Journals (Sweden)

Cordial M. Gillette

2017-07-01

Full Text Available Background: The empirical evidence for the use of RICE (rest, ice, compression, elevation has been questioned regarding its   clinical effectiveness. The component of RICE that has the least literature regarding its effectiveness is elevation. Objective: The objective of this study was to determine if various positions of elevation result in volumetric changes of the lower extremity. Methodology: A randomized crossover design was used to determine the effects of the four following conditions on volumetric changes of the lower extremity: seated at the end of a table (seated, lying supine (flat, lying supine with the foot elevated 12 inches off the table (elevated, and lying prone with the knees bent to 90 degrees (prone. The conditions were randomized using a Latin Square. Each subject completed all conditions with at least 24 hours between each session. Pre and post volumetric measurements were taken using a volumetric tank. The subject was placed in one of the four described testing positions for 30 minutes. The change in weight of the displaced water was the main outcome measure. The data was analyzed using an ANOVA of the pre and post measurements with a Bonferroni post hoc analysis. The level of significance was set at P<.05 for all analyses. Results: The only statistically significant difference was between the gravity dependent position (seated and all other positions (p <.001. There was no significant difference between lying supine (flat, on a bolster (elevated, or prone with the knees flexed to 90 degrees (prone. Conclusions: From these results, the extent of elevation does not appear to have an effect on changes in low leg volume. Elevation above the heart did not significantly improve reduction in limb volume, but removing the limb from a gravity dependent position might be beneficial.

Control and design of volumetric composition in pultruded hybrid fibre composites

DEFF Research Database (Denmark)

Madsen, Bo; Hashemi, Fariborz; Tahir, Paridah

2016-01-01

composition (i.e. volume fractions of fibres, matrix and porosity) in hybrid fibre composites. The model is based on a constant local fibre volume fraction criterion. Good agreement is found between model predictions and experimental data of pultruded hybrid kenaf/glass fibre composites with variable hybrid...... fibre weight mixing ratios. To demonstrate the suitability of the model, simulations are performed for four different cases of volumetric composition in hybrid kenaf/glass composites....

Spatial and volumetric changes of retroperitoneal sarcomas during pre-operative radiotherapy

International Nuclear Information System (INIS)

Wong, Philip; Dickie, Colleen; Lee, David; Chung, Peter; O’Sullivan, Brian; Letourneau, Daniel; Xu, Wei; Swallow, Carol; Gladdy, Rebecca; Catton, Charles

2014-01-01

Purpose: To determine the positional and volumetric changes of retroperitoneal sarcomas (RPS) during pre-operative external beam radiotherapy (PreRT). Material and methods: After excluding 2 patients who received chemotherapy prior to PreRT and 15 RPS that were larger than the field-of-view of cone-beam CT (CBCT), the positional and volumetric changes of RPS throughout PreRT were characterized in 19 patients treated with IMRT using CBCT image guidance. Analysis was performed on 118 CBCT images representing one image per week of those acquired daily during treatment. Intra-fraction breathing motions of the gross tumor volume (GTV) and kidneys were measured in 22 RPS patients simulated using 4D-CT. Fifteen other patients were excluded whose tumors were incompletely imaged on CBCT or who received pre-RT chemotherapy. Results: A GTV volumetric increase (mean: 6.6%, p = 0.035) during the first 2 weeks (CBCT1 vs. CBCT2) of treatment was followed by GTV volumetric decrease (mean: 4%, p = 0.009) by completion of radiotherapy (CBCT1 vs. CBCT6). Internal margins of 8.6, 15 and 15 mm in the lateral, anterior/posterior and superior/inferior directions would be required to account for inter-fraction displacements. The extent of GTV respiratory motion was significantly (p < 0.0001) correlated with more superiorly positioned tumors. Conclusion: Inter-fraction CBCT provides important volumetric and positional information of RPS which may improve PreRT quality and prompt re-planning. Planning target volume may be reduced using online soft-tissue matching to account for interfractional displacements of GTVs. Important breathing motion occurred in superiorly placed RPS supporting the utility of 4D-CT planning

Soft bilateral filtering volumetric shadows using cube shadow maps.

Directory of Open Access Journals (Sweden)

Hatam H Ali

Full Text Available Volumetric shadows often increase the realism of rendered scenes in computer graphics. Typical volumetric shadows techniques do not provide a smooth transition effect in real-time with conservation on crispness of boundaries. This research presents a new technique for generating high quality volumetric shadows by sampling and interpolation. Contrary to conventional ray marching method, which requires extensive time, this proposed technique adopts downsampling in calculating ray marching. Furthermore, light scattering is computed in High Dynamic Range buffer to generate tone mapping. The bilateral interpolation is used along a view rays to smooth transition of volumetric shadows with respect to preserving-edges. In addition, this technique applied a cube shadow map to create multiple shadows. The contribution of this technique isreducing the number of sample points in evaluating light scattering and then introducing bilateral interpolation to improve volumetric shadows. This contribution is done by removing the inherent deficiencies significantly in shadow maps. This technique allows obtaining soft marvelous volumetric shadows, having a good performance and high quality, which show its potential for interactive applications.

Volumetric expiratory high-resolution CT of the lung

International Nuclear Information System (INIS)

Nishino, Mizuki; Hatabu, Hiroto

2004-01-01

We developed a volumetric expiratory high-resolution CT (HRCT) protocol that provides combined inspiratory and expiratory volumetric imaging of the lung without increasing radiation exposure, and conducted a preliminary feasibility assessment of this protocol to evaluate diffuse lung disease with small airway abnormalities. The volumetric expiratory high-resolution CT increased the detectability of the conducting airway to the areas of air trapping (P<0.0001), and added significant information about extent and distribution of air trapping (P<0.0001)

A comparison of semi-automated volumetric vs linear measurement of small vestibular schwannomas.

Science.gov (United States)

MacKeith, Samuel; Das, Tilak; Graves, Martin; Patterson, Andrew; Donnelly, Neil; Mannion, Richard; Axon, Patrick; Tysome, James

2018-04-01

Accurate and precise measurement of vestibular schwannoma (VS) size is key to clinical management decisions. Linear measurements are used in routine clinical practice but are prone to measurement error. This study aims to compare a semi-automated volume segmentation tool against standard linear method for measuring small VS. This study also examines whether oblique tumour orientation can contribute to linear measurement error. Experimental comparison of observer agreement using two measurement techniques. Tertiary skull base unit. Twenty-four patients with unilateral sporadic small (linear dimension following reformatting to correct for oblique orientation of VS. Intra-observer ICC was higher for semi-automated volumetric when compared with linear measurements, 0.998 (95% CI 0.994-0.999) vs 0.936 (95% CI 0.856-0.972), p linear measurements, 0.989 (95% CI 0.975-0.995) vs 0.946 (95% CI 0.880-0.976), p = 0.0045. The intra-observer %SDD was similar for volumetric and linear measurements, 9.9% vs 11.8%. However, the inter-observer %SDD was greater for volumetric than linear measurements, 20.1% vs 10.6%. Following oblique reformatting to correct tumour angulation, the mean increase in size was 1.14 mm (p = 0.04). Semi-automated volumetric measurements are more repeatable than linear measurements when measuring small VS and should be considered for use in clinical practice. Oblique orientation of VS may contribute to linear measurement error.

Semiautomated volumetric response evaluation as an imaging biomarker in superior sulcus tumors

International Nuclear Information System (INIS)

Vos, C.G.; Paul, M.A.; Dahele, M.; Soernsen de Koste, J.R. van; Senan, S.; Bahce, I.; Smit, E.F.; Thunnissen, E.; Hartemink, K.J.

2014-01-01

Volumetric response to therapy has been suggested as a biomarker for patient-centered outcomes. The primary aim of this pilot study was to investigate whether the volumetric response to induction chemoradiotherapy was associated with pathological complete response (pCR) or survival in patients with superior sulcus tumors managed with trimodality therapy. The secondary aim was to evaluate a semiautomated method for serial volume assessment. In this retrospective study, treatment outcomes were obtained from a departmental database. The tumor was delineated on the computed tomography (CT) scan used for radiotherapy planning, which was typically performed during the first cycle of chemotherapy. These contours were transferred to the post-chemoradiotherapy diagnostic CT scan using deformable image registration (DIR) with/without manual editing. CT scans from 30 eligible patients were analyzed. Median follow-up was 51 months. Neither absolute nor relative reduction in tumor volume following chemoradiotherapy correlated with pCR or 2-year survival. The tumor volumes determined by DIR alone and DIR + manual editing correlated to a high degree (R 2 = 0.99, P < 0.01). Volumetric response to induction chemoradiotherapy was not correlated with pCR or survival in patients with superior sulcus tumors managed with trimodality therapy. DIR-based contour propagation merits further evaluation as a tool for serial volumetric assessment. (orig.)

Effect of Hydroxylamine Sulfate on Volumetric Behavior of Glycine, L-Alanine, and L-Arginine in Aqueous Solution

Directory of Open Access Journals (Sweden)

Jie Chen

2013-01-01

Full Text Available The apparent molar volumes of glycine, L-alanine, and L-arginine in aqueous hydroxylamine sulfate solutions have been determined at T=298.15 K and atmospheric pressure. The standard partial molar volumes, V20, corresponding partial molar volumes of transfer, ΔtrV20, and hydration numbers, NH, have been calculated for these α-amino acids from the experimental data. The ΔtrV20 values are positive for glycine, L-alanine, and L-arginine and are all increased with the increase in the concentration of hydroxylamine ions. These parameters obtained from the volumetric data are interpreted in terms of various mixing effects between amino acids and hydroxylamine sulfate in aqueous solutions.

In-situ volumetric topography of IC chips for defect detection using infrared confocal measurement with active structured light

International Nuclear Information System (INIS)

Chen, Liang-Chia; Le, Manh-Trung; Phuc, Dao Cong; Lin, Shyh-Tsong

2014-01-01

The article presents the development of in-situ integrated circuit (IC) chip defect detection techniques for automated clipping detection by proposing infrared imaging and full-field volumetric topography. IC chip inspection, especially held during or post IC packaging, has become an extremely critical procedure in IC fabrication to assure manufacturing quality and reduce production costs. To address this, in the article, microscopic infrared imaging using an electromagnetic light spectrum that ranges from 0.9 to 1.7 µm is developed to perform volumetric inspection of IC chips, in order to identify important defects such as silicon clipping, cracking or peeling. The main difficulty of infrared (IR) volumetric imaging lies in its poor image contrast, which makes it incapable of achieving reliable inspection, as infrared imaging is sensitive to temperature difference but insensitive to geometric variance of materials, resulting in difficulty detecting and quantifying defects precisely. To overcome this, 3D volumetric topography based on 3D infrared confocal measurement with active structured light, as well as light refractive matching principles, is developed to detect defects the size, shape and position of defects in ICs. The experimental results show that the algorithm is effective and suitable for in-situ defect detection of IC semiconductor packaging. The quality of defect detection, such as measurement repeatability and accuracy, is addressed. Confirmed by the experimental results, the depth measurement resolution can reach up to 0.3 µm, and the depth measurement uncertainty with one standard deviation was verified to be less than 1.0% of the full-scale depth-measuring range. (paper)

Minimization of variation in volumetric shrinkage and deflection on injection molding of Bi-aspheric lens using numerical simulation

Energy Technology Data Exchange (ETDEWEB)

Bensingh, R. Joseph [Central Institute of Plastics Engineering and Technology, Chennai (India); Boopathy, S. Rajendra [College of Engineering, Anna University, Chennai (India); Jebaraj, C. [Vellore Institutes of Technology, Chennai (India)

2016-11-15

The profile of a bi-aspheric lens is such a way that the thickness narrows down from center to periphery (convex). Injection molding of these profiles has high shrinkage in localized areas, which results in internal voids or sink marks when the part gets cool down to room temperature. This paper deals with the influence of injection molding process parameters such as mold surface temperature, melt temperature, injection time, V/P Switch over by percentage volume filled, packing pressure, and packing duration on the volumetric shrinkage and deflection. The optimal molding parameters for minimum variation in volumetric shrinkage and deflection of bi-aspheric lens have been determined with the application of computer numerical simulation integrated with optimization. The real experimental work carried out with optimal molding parameters and found to have a shallow and steep surface profile accuracy of 0.14 and 1.57 mm, 21.38-45.66 and 12.28-26.90 μm, 41.56-157.33 and 41.56-157.33 nm towards Radii of curvatures (RoC), surface roughness (Ra) and waviness of the surface profiles (profile error Pt), respectively.

Verbal Memory Decline following DBS for Parkinson's Disease: Structural Volumetric MRI Relationships.

Science.gov (United States)

Geevarghese, Ruben; Lumsden, Daniel E; Costello, Angela; Hulse, Natasha; Ayis, Salma; Samuel, Michael; Ashkan, Keyoumars

2016-01-01

Parkinson's disease is a chronic degenerative movement disorder. The mainstay of treatment is medical. In certain patients Deep Brain Stimulation (DBS) may be offered. However, DBS has been associated with post-operative neuropsychology changes, especially in verbal memory. Firstly, to determine if pre-surgical thalamic and hippocampal volumes were related to verbal memory changes following DBS. Secondly, to determine if clinical factors such as age, duration of symptoms or motor severity (UPDRS Part III score) were related to verbal memory changes. A consecutive group of 40 patients undergoing bilateral Subthalamic Nucleus (STN)-DBS for PD were selected. Brain MRI data was acquired, pre-processed and structural volumetric data was extracted using FSL. Verbal memory test scores for pre- and post-STN-DBS surgery were recorded. Linear regression was used to investigate the relationship between score change and structural volumetric data. A significant relationship was demonstrated between change in List Learning test score and thalamic (left, p = 0.02) and hippocampal (left, p = 0.02 and right p = 0.03) volumes. Duration of symptoms was also associated with List Learning score change (p = 0.02 to 0.03). Verbal memory score changes appear to have a relationship to pre-surgical MRI structural volumetric data. The findings of this study provide a basis for further research into the use of pre-surgical MRI to counsel PD patients regarding post-surgical verbal memory changes.

Volumetric velocimetry for fluid flows

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Discetti, Stefano; Coletti, Filippo

2018-04-01

In recent years, several techniques have been introduced that are capable of extracting 3D three-component velocity fields in fluid flows. Fast-paced developments in both hardware and processing algorithms have generated a diverse set of methods, with a growing range of applications in flow diagnostics. This has been further enriched by the increasingly marked trend of hybridization, in which the differences between techniques are fading. In this review, we carry out a survey of the prominent methods, including optical techniques and approaches based on medical imaging. An overview of each is given with an example of an application from the literature, while focusing on their respective strengths and challenges. A framework for the evaluation of velocimetry performance in terms of dynamic spatial range is discussed, along with technological trends and emerging strategies to exploit 3D data. While critical challenges still exist, these observations highlight how volumetric techniques are transforming experimental fluid mechanics, and that the possibilities they offer have just begun to be explored.

Effects of volumetric expansion in molecular crystals: A quantum mechanical investigation on aspirin and paracetamol most stable polymorphs

Science.gov (United States)

Adhikari, Kapil; Flurchick, Kenneth M.; Valenzano, Loredana

2015-02-01

This work reports a study performed at hybrid semi-empirical density functional level (B3LYP-D2*) of the physico-chemical properties of aspirin (acetylsalicylic acid) and paracetamol (acetaminophen) in their most stable crystalline forms. It is shown how effects arising from volumetric expansions influence the properties of the materials. Structural, energetic, and vibrational properties are in good agreement with experimental values reported at temperatures far from 0 K. Results show that the proposed approach is reliable enough to reproduce effects of volumetric expansion on lattice energies and other measurable physico-chemical observables related to inter-molecular forces.

Visualization and volumetric structures from MR images of the brain

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Parvin, B.; Johnston, W.; Robertson, D.

1994-03-01

Pinta is a system for segmentation and visualization of anatomical structures obtained from serial sections reconstructed from magnetic resonance imaging. The system approaches the segmentation problem by assigning each volumetric region to an anatomical structure. This is accomplished by satisfying constraints at the pixel level, slice level, and volumetric level. Each slice is represented by an attributed graph, where nodes correspond to regions and links correspond to the relations between regions. These regions are obtained by grouping pixels based on similarity and proximity. The slice level attributed graphs are then coerced to form a volumetric attributed graph, where volumetric consistency can be verified. The main novelty of our approach is in the use of the volumetric graph to ensure consistency from symbolic representations obtained from individual slices. In this fashion, the system allows errors to be made at the slice level, yet removes them when the volumetric consistency cannot be verified. Once the segmentation is complete, the 3D surfaces of the brain can be constructed and visualized.

A three-dimensional-weighted cone beam filtered backprojection (CB-FBP) algorithm for image reconstruction in volumetric CT-helical scanning

International Nuclear Information System (INIS)

Tang Xiangyang; Hsieh Jiang; Nilsen, Roy A; Dutta, Sandeep; Samsonov, Dmitry; Hagiwara, Akira

2006-01-01

Based on the structure of the original helical FDK algorithm, a three-dimensional (3D)-weighted cone beam filtered backprojection (CB-FBP) algorithm is proposed for image reconstruction in volumetric CT under helical source trajectory. In addition to its dependence on view and fan angles, the 3D weighting utilizes the cone angle dependency of a ray to improve reconstruction accuracy. The 3D weighting is ray-dependent and the underlying mechanism is to give a favourable weight to the ray with the smaller cone angle out of a pair of conjugate rays but an unfavourable weight to the ray with the larger cone angle out of the conjugate ray pair. The proposed 3D-weighted helical CB-FBP reconstruction algorithm is implemented in the cone-parallel geometry that can improve noise uniformity and image generation speed significantly. Under the cone-parallel geometry, the filtering is naturally carried out along the tangential direction of the helical source trajectory. By exploring the 3D weighting's dependence on cone angle, the proposed helical 3D-weighted CB-FBP reconstruction algorithm can provide significantly improved reconstruction accuracy at moderate cone angle and high helical pitches. The 3D-weighted CB-FBP algorithm is experimentally evaluated by computer-simulated phantoms and phantoms scanned by a diagnostic volumetric CT system with a detector dimension of 64 x 0.625 mm over various helical pitches. The computer simulation study shows that the 3D weighting enables the proposed algorithm to reach reconstruction accuracy comparable to that of exact CB reconstruction algorithms, such as the Katsevich algorithm, under a moderate cone angle (4 deg.) and various helical pitches. Meanwhile, the experimental evaluation using the phantoms scanned by a volumetric CT system shows that the spatial resolution along the z-direction and noise characteristics of the proposed 3D-weighted helical CB-FBP reconstruction algorithm are maintained very well in comparison to the FDK

Extended Kalman filtering for continuous volumetric MR-temperature imaging.

Science.gov (United States)

Denis de Senneville, Baudouin; Roujol, Sébastien; Hey, Silke; Moonen, Chrit; Ries, Mario

2013-04-01

Real time magnetic resonance (MR) thermometry has evolved into the method of choice for the guidance of high-intensity focused ultrasound (HIFU) interventions. For this role, MR-thermometry should preferably have a high temporal and spatial resolution and allow observing the temperature over the entire targeted area and its vicinity with a high accuracy. In addition, the precision of real time MR-thermometry for therapy guidance is generally limited by the available signal-to-noise ratio (SNR) and the influence of physiological noise. MR-guided HIFU would benefit of the large coverage volumetric temperature maps, including characterization of volumetric heating trajectories as well as near- and far-field heating. In this paper, continuous volumetric MR-temperature monitoring was obtained as follows. The targeted area was continuously scanned during the heating process by a multi-slice sequence. Measured data and a priori knowledge of 3-D data derived from a forecast based on a physical model were combined using an extended Kalman filter (EKF). The proposed reconstruction improved the temperature measurement resolution and precision while maintaining guaranteed output accuracy. The method was evaluated experimentally ex vivo on a phantom, and in vivo on a porcine kidney, using HIFU heating. On the in vivo experiment, it allowed the reconstruction from a spatio-temporally under-sampled data set (with an update rate for each voxel of 1.143 s) to a 3-D dataset covering a field of view of 142.5×285×54 mm(3) with a voxel size of 3×3×6 mm(3) and a temporal resolution of 0.127 s. The method also provided noise reduction, while having a minimal impact on accuracy and latency.

Comparison of experimental methods for determination of the volumetric mass transfer coefficient in fermentation processes

Energy Technology Data Exchange (ETDEWEB)

Tobajas, M.; Garcia-Calvo, E. [Dept. de Ingenieria Quimica, Univ. de Alcala, Alcala de Henares (Spain)

2000-05-01

Mass transfer in bioreactors has been examined. In the present work, dynamic methods are used for the determination of K{sub L}a values for water, model media and a fermentation broth (Candida utilis) in an airlift reactor. The conventional dynamic method is applied at the end of the microbial process in order to avoid an alteration in the metabolism of the microorganisms. New dynamic methods are used to determine K{sub L}a in an airlift reactor during the microbial growth of Candida utilis on glucose. One of the methods is based on the continuous measurement of carbon dioxide production while the other method is based on the relationship between the oxygen transfer and biomass growth rates. These methods of determining K{sub L}a does not interfere with the microorganisms action. A theoretical mass transfer model has been used for K{sub L}a estimation for the systems described above. Some differences between calculated and measured values are found for fermentation processes due to the model is developed for two-phase air-water systems. Nevertheless, the average deviation between the predicted values and those obtained from the relationship between oxygen transfer and biomass production rates are lower than 25% in any case. (orig.)

Degree of contribution (DoC) feature selection algorithm for structural brain MRI volumetric features in depression detection.

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Kipli, Kuryati; Kouzani, Abbas Z

2015-07-01

Accurate detection of depression at an individual level using structural magnetic resonance imaging (sMRI) remains a challenge. Brain volumetric changes at a structural level appear to have importance in depression biomarkers studies. An automated algorithm is developed to select brain sMRI volumetric features for the detection of depression. A feature selection (FS) algorithm called degree of contribution (DoC) is developed for selection of sMRI volumetric features. This algorithm uses an ensemble approach to determine the degree of contribution in detection of major depressive disorder. The DoC is the score of feature importance used for feature ranking. The algorithm involves four stages: feature ranking, subset generation, subset evaluation, and DoC analysis. The performance of DoC is evaluated on the Duke University Multi-site Imaging Research in the Analysis of Depression sMRI dataset. The dataset consists of 115 brain sMRI scans of 88 healthy controls and 27 depressed subjects. Forty-four sMRI volumetric features are used in the evaluation. The DoC score of forty-four features was determined as the accuracy threshold (Acc_Thresh) was varied. The DoC performance was compared with that of four existing FS algorithms. At all defined Acc_Threshs, DoC outperformed the four examined FS algorithms for the average classification score and the maximum classification score. DoC has a good ability to generate reduced-size subsets of important features that could yield high classification accuracy. Based on the DoC score, the most discriminant volumetric features are those from the left-brain region.

Volumetric fat-water separated T2-weighted MRI

International Nuclear Information System (INIS)

Vasanawala, Shreyas S.; Sonik, Arvind; Madhuranthakam, Ananth J.; Venkatesan, Ramesh; Lai, Peng; Brau, Anja C.S.

2011-01-01

Pediatric body MRI exams often cover multiple body parts, making the development of broadly applicable protocols and obtaining uniform fat suppression a challenge. Volumetric T2 imaging with Dixon-type fat-water separation might address this challenge, but it is a lengthy process. We develop and evaluate a faster two-echo approach to volumetric T2 imaging with fat-water separation. A volumetric spin-echo sequence was modified to include a second shifted echo so two image sets are acquired. A region-growing reconstruction approach was developed to decompose separate water and fat images. Twenty-six children were recruited with IRB approval and informed consent. Fat-suppression quality was graded by two pediatric radiologists and compared against conventional fat-suppressed fast spin-echo T2-W images. Additionally, the value of in- and opposed-phase images was evaluated. Fat suppression on volumetric images had high quality in 96% of cases (95% confidence interval of 80-100%) and were preferred over or considered equivalent to conventional two-dimensional fat-suppressed FSE T2 imaging in 96% of cases (95% confidence interval of 78-100%). In- and opposed-phase images had definite value in 12% of cases. Volumetric fat-water separated T2-weighted MRI is feasible and is likely to yield improved fat suppression over conventional fat-suppressed T2-weighted imaging. (orig.)

Exploring interaction with 3D volumetric displays

Science.gov (United States)

Grossman, Tovi; Wigdor, Daniel; Balakrishnan, Ravin

2005-03-01

Volumetric displays generate true volumetric 3D images by actually illuminating points in 3D space. As a result, viewing their contents is similar to viewing physical objects in the real world. These displays provide a 360 degree field of view, and do not require the user to wear hardware such as shutter glasses or head-trackers. These properties make them a promising alternative to traditional display systems for viewing imagery in 3D. Because these displays have only recently been made available commercially (e.g., www.actuality-systems.com), their current use tends to be limited to non-interactive output-only display devices. To take full advantage of the unique features of these displays, however, it would be desirable if the 3D data being displayed could be directly interacted with and manipulated. We investigate interaction techniques for volumetric display interfaces, through the development of an interactive 3D geometric model building application. While this application area itself presents many interesting challenges, our focus is on the interaction techniques that are likely generalizable to interactive applications for other domains. We explore a very direct style of interaction where the user interacts with the virtual data using direct finger manipulations on and around the enclosure surrounding the displayed 3D volumetric image.

Cost-effectiveness of volumetric alcohol taxation in Australia.

Science.gov (United States)

Byrnes, Joshua M; Cobiac, Linda J; Doran, Christopher M; Vos, Theo; Shakeshaft, Anthony P

2010-04-19

To estimate the potential health benefits and cost savings of an alcohol tax rate that applies equally to all alcoholic beverages based on their alcohol content (volumetric tax) and to compare the cost savings with the cost of implementation. Mathematical modelling of three scenarios of volumetric alcohol taxation for the population of Australia: (i) no change in deadweight loss, (ii) no change in tax revenue, and (iii) all alcoholic beverages taxed at the same rate as spirits. Estimated change in alcohol consumption, tax revenue and health benefit. The estimated cost of changing to a volumetric tax rate is $18 million. A volumetric tax that is deadweight loss-neutral would increase the cost of beer and wine and reduce the cost of spirits, resulting in an estimated annual increase in taxation revenue of $492 million and a 2.77% reduction in annual consumption of pure alcohol. The estimated net health gain would be 21 000 disability-adjusted life-years (DALYs), with potential cost offsets of $110 million per annum. A tax revenue-neutral scenario would result in an 0.05% decrease in consumption, and a tax on all alcohol at a spirits rate would reduce consumption by 23.85% and increase revenue by $3094 million [corrected]. All volumetric tax scenarios would provide greater health benefits and cost savings to the health sector than the existing taxation system, based on current understandings of alcohol-related health effects. An equalized volumetric tax that would reduce beer and wine consumption while increasing the consumption of spirits would need to be approached with caution. Further research is required to examine whether alcohol-related health effects vary by type of alcoholic beverage independent of the amount of alcohol consumed to provide a strong evidence platform for alcohol taxation policies.

Transfer laws between water and freon 113 for average volumetric steam quality, pressure drop, and critical heat flux

International Nuclear Information System (INIS)

Nabizadeh, H.

1977-01-01

Simulation of the thermohydraulic processes of the steady-state reactor operation with boiling water and typical fuel element geometries leads to considerable increase of the heat rates to be tranferred and thus to an increase of the experimental cost which can hardly be justified. By proper choice of a model fluid with low heat of evaporation the system parameters like pressure, temperature, and heat rate, while retaining the original geometry, may be reduced to a fraction of those of the original fluid water. This permits not only a decrease in experimental cost but also a modification of the existing calculation data under more favorable experimental conditions. Starting from these considerations the cooling medium R113 was used as model fluid in carrying out the experiments. The necessary knowledge of the thermodynamical laws of simularity, however, have to be determined first of all in simple geometries and the scaling factors are then derived from them. In this connection the following experimental studies have been carried out with R113: a) average volumetric steam quality; b) two-phase pressure drop; c) critical heat flux. (orig.) [de

Effect of inflow discharges on the development of matric suction and volumetric water content for dike during overtopping tests

Science.gov (United States)

Hassan, Marwan A.; Ismail, Mohd A. M.

2017-10-01

The point of this review is to depict the impact of various inflow discharge rate releases on the instruments of matric suction and volumetric water content during an experimental test of spatial overtopping failure at school of civil engineering in universiti Sains of Malaysia. A dry sand dike was conducted inside small flume channel with twelve sensors of tensiometer and Time-Domain Reflectometer (TDR). Instruments are installed in the soil at different locations in downstream and upstream slopes of the dike for measuring the response of matric suction and volumetric water content, respectively. Two values of inflow discharge rates of 30 and 40 L/min are utilized as a part of these experiments to simulate the effectiveness of water reservoirs in erosion mechanism. The outcomes demonstrate that the matric suction and volumetric water content are decreased and increased, respectively for both inflow discharges. The higher inflow discharges accelerate the saturation of dike soil and the erosion process faster than that for the lower inflow discharges.

Performance-scalable volumetric data classification for online industrial inspection

Science.gov (United States)

Abraham, Aby J.; Sadki, Mustapha; Lea, R. M.

2002-03-01

Non-intrusive inspection and non-destructive testing of manufactured objects with complex internal structures typically requires the enhancement, analysis and visualization of high-resolution volumetric data. Given the increasing availability of fast 3D scanning technology (e.g. cone-beam CT), enabling on-line detection and accurate discrimination of components or sub-structures, the inherent complexity of classification algorithms inevitably leads to throughput bottlenecks. Indeed, whereas typical inspection throughput requirements range from 1 to 1000 volumes per hour, depending on density and resolution, current computational capability is one to two orders-of-magnitude less. Accordingly, speeding up classification algorithms requires both reduction of algorithm complexity and acceleration of computer performance. A shape-based classification algorithm, offering algorithm complexity reduction, by using ellipses as generic descriptors of solids-of-revolution, and supporting performance-scalability, by exploiting the inherent parallelism of volumetric data, is presented. A two-stage variant of the classical Hough transform is used for ellipse detection and correlation of the detected ellipses facilitates position-, scale- and orientation-invariant component classification. Performance-scalability is achieved cost-effectively by accelerating a PC host with one or more COTS (Commercial-Off-The-Shelf) PCI multiprocessor cards. Experimental results are reported to demonstrate the feasibility and cost-effectiveness of the data-parallel classification algorithm for on-line industrial inspection applications.

CT volumetric measurements of the orbits in Graves' disease

International Nuclear Information System (INIS)

Krahe, T.; Schlolaut, K.H.; Poss, T.; Trier, H.G.; Lackner, K.; Bonn Univ.; Bonn Univ.

1989-01-01

The volumes of the four recti muscles and the orbital fat was measured by CT in 40 normal persons and in 60 patients with clinically confirmed Graves' disease. Compared with normal persons, 42 patients (70%) showed an increase in muscle volume and 28 patients (46.7%) an increase in the amount of fat. In nine patients (15%) muscle volume was normal, but the fat was increased. By using volumetric measurements, the amount of fat in the orbits in patients with Graves' disease could be determined. (orig.) [de

Volumetric Synthetic Aperture Imaging with a Piezoelectric 2-D Row-Column Probe

DEFF Research Database (Denmark)

Bouzari, Hamed; Engholm, Mathias; Christiansen, Thomas Lehrmann

2016-01-01

The synthetic aperture (SA) technique can be used for achieving real-time volumetric ultrasound imaging using 2-D row-column addressed transducers. This paper investigates SA volumetric imaging performance of an in-house prototyped 3 MHz λ/2-pitch 62+62 element piezoelectric 2-D row-column addres......The synthetic aperture (SA) technique can be used for achieving real-time volumetric ultrasound imaging using 2-D row-column addressed transducers. This paper investigates SA volumetric imaging performance of an in-house prototyped 3 MHz λ/2-pitch 62+62 element piezoelectric 2-D row...

Short-term mechanisms influencing volumetric brain dynamics

Directory of Open Access Journals (Sweden)

Nikki Dieleman

2017-01-01

Full Text Available With the use of magnetic resonance imaging (MRI and brain analysis tools, it has become possible to measure brain volume changes up to around 0.5%. Besides long-term brain changes caused by atrophy in aging or neurodegenerative disease, short-term mechanisms that influence brain volume may exist. When we focus on short-term changes of the brain, changes may be either physiological or pathological. As such determining the cause of volumetric dynamics of the brain is essential. Additionally for an accurate interpretation of longitudinal brain volume measures by means of neurodegeneration, knowledge about the short-term changes is needed. Therefore, in this review, we discuss the possible mechanisms influencing brain volumes on a short-term basis and set-out a framework of MRI techniques to be used for volumetric changes as well as the used analysis tools. 3D T1-weighted images are the images of choice when it comes to MRI of brain volume. These images are excellent to determine brain volume and can be used together with an analysis tool to determine the degree of volume change. Mechanisms that decrease global brain volume are: fluid restriction, evening MRI measurements, corticosteroids, antipsychotics and short-term effects of pathological processes like Alzheimer's disease, hypertension and Diabetes mellitus type II. Mechanisms increasing the brain volume include fluid intake, morning MRI measurements, surgical revascularization and probably medications like anti-inflammatory drugs and anti-hypertensive medication. Exercise was found to have no effect on brain volume on a short-term basis, which may imply that dehydration caused by exercise differs from dehydration by fluid restriction. In the upcoming years, attention should be directed towards studies investigating physiological short-term changes within the light of long-term pathological changes. Ultimately this may lead to a better understanding of the physiological short-term effects of

Volumetric 3D Display System with Static Screen

Science.gov (United States)

Geng, Jason

2011-01-01

Current display technology has relied on flat, 2D screens that cannot truly convey the third dimension of visual information: depth. In contrast to conventional visualization that is primarily based on 2D flat screens, the volumetric 3D display possesses a true 3D display volume, and places physically each 3D voxel in displayed 3D images at the true 3D (x,y,z) spatial position. Each voxel, analogous to a pixel in a 2D image, emits light from that position to form a real 3D image in the eyes of the viewers. Such true volumetric 3D display technology provides both physiological (accommodation, convergence, binocular disparity, and motion parallax) and psychological (image size, linear perspective, shading, brightness, etc.) depth cues to human visual systems to help in the perception of 3D objects. In a volumetric 3D display, viewers can watch the displayed 3D images from a completely 360 view without using any special eyewear. The volumetric 3D display techniques may lead to a quantum leap in information display technology and can dramatically change the ways humans interact with computers, which can lead to significant improvements in the efficiency of learning and knowledge management processes. Within a block of glass, a large amount of tiny dots of voxels are created by using a recently available machining technique called laser subsurface engraving (LSE). The LSE is able to produce tiny physical crack points (as small as 0.05 mm in diameter) at any (x,y,z) location within the cube of transparent material. The crack dots, when illuminated by a light source, scatter the light around and form visible voxels within the 3D volume. The locations of these tiny voxels are strategically determined such that each can be illuminated by a light ray from a high-resolution digital mirror device (DMD) light engine. The distribution of these voxels occupies the full display volume within the static 3D glass screen. This design eliminates any moving screen seen in previous

Evaluation of Fatigue Crack Initiation for Volumetric Flaw in Pressure Tube

International Nuclear Information System (INIS)

Choi, Sung Nam; Yoo, Hyun Joo

2005-01-01

CAN/CSA.N285.4-94 requires the periodic inservice inspection and surveillance of pressure tubes in operating CANDU nuclear power reactors. If the inspection results reveal a flaw exceeding the acceptance criteria of the Code, the flaw must be evaluated to determine if the pressure is acceptable for continued service. Currently, the flaw evaluation methodology and acceptance criteria specified in CSA-N285.05-2005, 'Technical requirements for in-service evaluation of zirconium alloy pressure tubes in CANDU reactors'. The Code is applicable to zirconium alloy pressure tubes. The evaluation methodology for a crack-like flaw is similar to that of ASME B and PV Sec. XI, 'Inservice Inspection of Nuclear Power Plant Components'. However, the evaluation methodology for a blunt volumetric flaw is described in CSA-N285.05-2005 code. The object of this paper is to address the fatigue crack initiation evaluation for the blunt volumetric flaw as it applies to the pressure tube at Wolsong NPP

A volumetric data system for environmental robotics

International Nuclear Information System (INIS)

Tourtellott, J.

1994-01-01

A three-dimensional, spatially organized or volumetric data system provides an effective means for integrating and presenting environmental sensor data to robotic systems and operators. Because of the unstructed nature of environmental restoration applications, new robotic control strategies are being developed that include environmental sensors and interactive data interpretation. The volumetric data system provides key features to facilitate these new control strategies including: integrated representation of surface, subsurface and above-surface data; differentiation of mapped and unmapped regions in space; sculpting of regions in space to best exploit data from line-of-sight sensors; integration of diverse sensor data (for example, dimensional, physical/geophysical, chemical, and radiological); incorporation of data provided at different spatial resolutions; efficient access for high-speed visualization and analysis; and geometric modeling tools to update a open-quotes world modelclose quotes of an environment. The applicability to underground storage tank remediation and buried waste site remediation are demonstrated in several examples. By integrating environmental sensor data into robotic control, the volumetric data system will lead to safer, faster, and more cost-effective environmental cleanup

Volumetric full-range magnetomotive optical coherence tomography

Science.gov (United States)

Ahmad, Adeel; Kim, Jongsik; Shemonski, Nathan D.; Marjanovic, Marina; Boppart, Stephen A.

2014-01-01

Abstract. Magnetomotive optical coherence tomography (MM-OCT) can be utilized to spatially localize the presence of magnetic particles within tissues or organs. These magnetic particle-containing regions are detected by using the capability of OCT to measure small-scale displacements induced by the activation of an external electromagnet coil typically driven by a harmonic excitation signal. The constraints imposed by the scanning schemes employed and tissue viscoelastic properties limit the speed at which conventional MM-OCT data can be acquired. Realizing that electromagnet coils can be designed to exert MM force on relatively large tissue volumes (comparable or larger than typical OCT imaging fields of view), we show that an order-of-magnitude improvement in three-dimensional (3-D) MM-OCT imaging speed can be achieved by rapid acquisition of a volumetric scan during the activation of the coil. Furthermore, we show volumetric (3-D) MM-OCT imaging over a large imaging depth range by combining this volumetric scan scheme with full-range OCT. Results with tissue equivalent phantoms and a biological tissue are shown to demonstrate this technique. PMID:25472770

Green chemistry volumetric titration kit for pharmaceutical formulations: Econoburette

Directory of Open Access Journals (Sweden)

Man Singh

2009-08-01

Full Text Available Stopcock SC and Spring Sp models of Econoburette (Calibrated, RTC (NR, Ministry of Small Scale Industries, Government of India, developed for semimicro volumetric titration of pharmaceutical formulations are reported. These are economized and risk free titration where pipette is replaced by an inbuilt pipette and conical flask by inbuilt bulb. A step of pipetting of stock solution by mouth is deleted. It is used to allow solution exposure to user’s body. This risk is removed and even volatile and toxic solutions are titrated with full proof safety. Econoburette minimizes use of materials and time by 90 % and prevent discharge of polluting effluent to environment. Few acid and base samples are titrated and an analysis of experimental expenditure is described in the papers.

Experimental and computational studies of nanofluids

Science.gov (United States)

Vajjha, Ravikanth S.

The goals of this dissertation were (i) to experimentally investigate the fluid dynamic and heat transfer performance of nanofluids in a circular tube, (ii) to study the influence of temperature and particle volumetric concentration of nanofluids on thermophysical properties, heat transfer and pumping power, (iii) to measure the rheological properties of various nanofluids and (iv) to investigate using a computational fluid dynamic (CFD) technique the performance of nanofluids in the flat tube of a radiator. Nanofluids are a new class of fluids prepared by dispersing nanoparticles with average sizes of less than 100 nm in traditional heat transfer fluids such as water, oil, ethylene glycol and propylene glycol. In cold regions of the world, the choice of base fluid for heat transfer applications is an ethylene glycol or propylene glycol mixed with water in different proportions. In the present research, a 60% ethylene glycol (EG) or propylene glycol (PG) and 40% water (W) by mass fluid mixture (60:40 EG/W or 60:40 PG/W) was used as a base fluid, which provides freeze protection to a very low level of temperature. Experiments were conducted to measure the convective heat transfer coefficient and pressure loss of nanofluids flowing in a circular tube in the fully developed turbulent regime. The experimental measurements were carried out for aluminum oxide (Al2O3), copper oxide (CuO) and silicon dioxide (SiO2) nanoparticles dispersed in 60:40 EG/W base fluid. Experiments revealed that the heat transfer coefficient of nanofluids showed an increase with the particle volumetric concentration. Pressure loss was also observed to increase with the nanoparticle volumetric concentration. New correlations for the Nusselt number and the friction factor were developed. The effects of temperature and particle volumetric concentration on different thermophysical properties (e.g. viscosity, thermal conductivity, specific heat and density) and subsequently on the Prandtl number

Volumetric, viscosity, and electrical conductivity properties of aqueous solutions of two n-butylammonium-based protic ionic liquids at several temperatures

International Nuclear Information System (INIS)

Xu, Yingjie

2013-01-01

Highlights: • Densities and viscosities of N4AC + water and N4NO 3 + water mixtures were measured. • Volumetric and viscosity properties were calculated. • Redlich–Kister equation was used to correlate the excess molar volumes and viscosity deviations. • Electrical conductivity was fitted according to the empirical Casteel–Amis equation. • The interactions and structural effects of N4AC or N4NO 3 with water were analyzed. -- Abstract: Densities and viscosities of (n-butylammonium acetate (N4AC) protic ionic liquid + water) and (n-butylammonium nitrate (N4NO 3 ) protic ionic liquid + water) mixtures were measured at T = (293.15, 298.15, 303.15, 308.15, and 313.15) K under atmospheric pressure. Electrical conductivities of the above-mentioned systems were determined at 298.15 K. Excess molar volumes and viscosity deviations were obtained from the experimental results and fitted to the Redlich–Kister equation with satisfactory results. Other volumetric properties, such as apparent molar volumes, partial molar volumes, and excess partial molar volumes were also calculated. The concentration dependence of electrical conductivity was fitted according to the empirical Casteel–Amis equation. Based on the measured and derived properties, the molecular interactions and structural factors in the above-mentioned systems were discussed

Novel monorail infusion catheter for volumetric coronary blood flow measurement in humans: in vitro validation

NARCIS (Netherlands)

van 't Veer, M.; Adjedj, J.; Wijnbergen, I.; Tóth, G.G.; Rutten, M.C.M.; Barbato, E.; van Nunen, L.X.; Pijls, N.H.J.; de Bruyne, B.

2016-01-01

AIMS: The aim of this study is to validate a novel monorail infusion catheter for thermodilution-based quantitative coronary flow measurements. METHODS AND RESULTS: Based on the principles of thermodilution, volumetric coronary flow can be determined from the flow rate of a continuous saline

In vivo volumetric analysis of tumours by CT: What is the value of the calculation of tumour volumes for recurrent rectal cancer?

International Nuclear Information System (INIS)

Aydin, H.; Richter, E.; Feyerabend, T.; Bohndorf, W.

1990-01-01

The volumetric analysis of a tumour by CT is a reliable and clinically important method of examination which is rarely used. As for oncology, the importance of this method is based upon the determination of the stage of remission posttherapeutically, especially in those cases which respond to therapy without a roentgenologic change in comparison to pretherapeutic findings. This applies in particular for the evaluation of CT images. In this study 115 CT examinations of 38 patients with recurrent rectal cancer were evaluated and the tumour remission was measured by an exact determination of the tumour volume before and after radiotherapy. The results were compared with the CT findings without volumetric analysis. A change of the tumour size up to 20% of the pretherapeutic volume which eludes from the visual perception can be revealed by a subtle CT-assisted volumetric analysis. Formulas for calculation of the volume or the data concerning length, width and depth of a mass prove to be insufficient or incorrect. Therefore the correct evaluation of a tumour regression or progression shoud be done more often by CT-assisted volumetric analysis. (orig.) [de

Experimental study on the performance of single screw expanders by gap adjustment

International Nuclear Information System (INIS)

Wang, Wei; Wu, Yu-ting; Ma, Chong-fang; Xia, Guo-dong; Wang, Jing-fu

2013-01-01

Improving thermodynamic efficiency of prime movers is the key issue for efficient utilization of low-temperature heat resources. Single screw expander may be a good candidate because of its many good characteristics. Precisions in manufacture and assembly are very important factors to the performance of single screw expanders. In this paper, the shaft efficiency, volumetric efficiency and gas consumption rate of the single screw expander prototypes were tested and discussed. We have manufactured three prototypes with different gaps to investigate their performance. The first prototype (A) has the largest gap, and the second one (B) has the smallest gap, the third prototype (C) has the medium gap configuration. Experimental result of the prototypes was obtained. From the experimental data of prototype A, the power output was about 5 kW, the gas consumption rate was above 105 kg/kWh and the volumetric efficiency was below 20%, the shaft efficiency was only 34%. From experimental data of prototype B, the mass flow rate was significantly decreased. The power output was only 1.4 kW and the volumetric efficiency was slightly lower than prototype A. The gas consumption rate was much more than that of prototype A. From the experimental data of prototype C, the power output was about 4.5 kW, but the mass flow rate was sharply decreased. The gas consumption rate was about 65 kg/kWh, the maximum volumetric efficiency was about 66%, and the shaft efficiency was about 60%. The experimental results indicated that prototype C of single screw expanders had the best overall performance, which may be further improved by optimizing its configuration. - Highlights: • The experiment for three single screw expander prototypes at different gaps was carried out. • Maximum shaft efficiency is about 60%. • Minimum gas consumption rate is about 65 kg/kWh. • Maximum volumetric efficiency is about 66%. • Leaked gas still has part of working capability

A prospective pilot study measuring muscle volumetric change in amyotrophic lateral sclerosis.

Science.gov (United States)

Jenkins, Thomas M; Burness, Christine; Connolly, Daniel J; Rao, D Ganesh; Hoggard, Nigel; Mawson, Susan; McDermott, Christopher J; Wilkinson, Iain D; Shaw, Pamela J

2013-09-01

Our objective was to investigate the potential of muscle volume, measured with magnetic resonance (MR), as a biomarker to quantify disease progression in patients with amyotrophic lateral sclerosis (ALS). In this longitudinal pilot study, we first sought to determine the stability of volumetric muscle MR measurements in 11 control subjects at two time-points. We assessed feasibility of detecting atrophy in four patients with ALS, followed at three-month intervals for 12 months. Muscle power and MR volume were measured in thenar eminence (TEm), first dorsal interosseous (1DIO), tibialis anterior (TA) and tongue. Changes over time were assessed using linear regression models and t-tests. Results demonstrated that, in controls, no volumetric MR changes were seen (mean volume variation in all muscles 0.1). In patients, between-subject heterogeneity was identified. Trends for volume loss were found in TEm (mean, - 26.84%, p = 0.056) and TA (- 8.29%, p = 0.077), but not in 1DIO (- 18.47%, p = 0.121) or tongue (< 5%, p = 0.367). In conclusion, volumetric muscle MR appears a stable measure in controls, and progressive volume loss was demonstrable in individuals with ALS in whom clinical weakness progressed. In this small study, subclinical atrophy was not demonstrable using muscle MR. Clinico-radiological discordance between muscle weakness and MR atrophy could reflect a contribution of upper motor neuron pathology.

MR volumetric assessment of endolymphatic hydrops

International Nuclear Information System (INIS)

Guerkov, R.; Berman, A.; Jerin, C.; Krause, E.; Dietrich, O.; Flatz, W.; Ertl-Wagner, B.; Keeser, D.

2015-01-01

We aimed to volumetrically quantify endolymph and perilymph spaces of the inner ear in order to establish a methodological basis for further investigations into the pathophysiology and therapeutic monitoring of Meniere's disease. Sixteen patients (eight females, aged 38-71 years) with definite unilateral Meniere's disease were included in this study. Magnetic resonance (MR) cisternography with a T2-SPACE sequence was combined with a Real reconstruction inversion recovery (Real-IR) sequence for delineation of inner ear fluid spaces. Machine learning and automated local thresholding segmentation algorithms were applied for three-dimensional (3D) reconstruction and volumetric quantification of endolymphatic hydrops. Test-retest reliability was assessed by the intra-class coefficient; correlation of cochlear endolymph volume ratio with hearing function was assessed by the Pearson correlation coefficient. Endolymph volume ratios could be reliably measured in all patients, with a mean (range) value of 15 % (2-25) for the cochlea and 28 % (12-40) for the vestibulum. Test-retest reliability was excellent, with an intra-class coefficient of 0.99. Cochlear endolymphatic hydrops was significantly correlated with hearing loss (r = 0.747, p = 0.001). MR imaging after local contrast application and image processing, including machine learning and automated local thresholding, enable the volumetric quantification of endolymphatic hydrops. This allows for a quantitative assessment of the effect of therapeutic interventions on endolymphatic hydrops. (orig.)

MR volumetric assessment of endolymphatic hydrops

Energy Technology Data Exchange (ETDEWEB)

Guerkov, R.; Berman, A.; Jerin, C.; Krause, E. [University of Munich, Department of Otorhinolaryngology Head and Neck Surgery, Grosshadern Medical Centre, Munich (Germany); University of Munich, German Centre for Vertigo and Balance Disorders, Grosshadern Medical Centre, Marchioninistr. 15, 81377, Munich (Germany); Dietrich, O.; Flatz, W.; Ertl-Wagner, B. [University of Munich, Institute of Clinical Radiology, Grosshadern Medical Centre, Munich (Germany); Keeser, D. [University of Munich, Institute of Clinical Radiology, Grosshadern Medical Centre, Munich (Germany); University of Munich, German Centre for Vertigo and Balance Disorders, Grosshadern Medical Centre, Marchioninistr. 15, 81377, Munich (Germany); University of Munich, Department of Psychiatry and Psychotherapy, Innenstadtkliniken Medical Centre, Munich (Germany)

2014-10-16

We aimed to volumetrically quantify endolymph and perilymph spaces of the inner ear in order to establish a methodological basis for further investigations into the pathophysiology and therapeutic monitoring of Meniere's disease. Sixteen patients (eight females, aged 38-71 years) with definite unilateral Meniere's disease were included in this study. Magnetic resonance (MR) cisternography with a T2-SPACE sequence was combined with a Real reconstruction inversion recovery (Real-IR) sequence for delineation of inner ear fluid spaces. Machine learning and automated local thresholding segmentation algorithms were applied for three-dimensional (3D) reconstruction and volumetric quantification of endolymphatic hydrops. Test-retest reliability was assessed by the intra-class coefficient; correlation of cochlear endolymph volume ratio with hearing function was assessed by the Pearson correlation coefficient. Endolymph volume ratios could be reliably measured in all patients, with a mean (range) value of 15 % (2-25) for the cochlea and 28 % (12-40) for the vestibulum. Test-retest reliability was excellent, with an intra-class coefficient of 0.99. Cochlear endolymphatic hydrops was significantly correlated with hearing loss (r = 0.747, p = 0.001). MR imaging after local contrast application and image processing, including machine learning and automated local thresholding, enable the volumetric quantification of endolymphatic hydrops. This allows for a quantitative assessment of the effect of therapeutic interventions on endolymphatic hydrops. (orig.)

Modeling of macrosegregation caused by volumetric deformation in a coherent mushy zone

Science.gov (United States)

Nicolli, Lilia C.; Mo, Asbjørn; M'hamdi, Mohammed

2005-02-01

A two-phase volume-averaged continuum model is presented that quantifies macrosegregation formation during solidification of metallic alloys caused by deformation of the dendritic network and associated melt flow in the coherent part of the mushy zone. Also, the macrosegregation formation associated with the solidification shrinkage (inverse segregation) is taken into account. Based on experimental evidence established elsewhere, volumetric viscoplastic deformation (densification/dilatation) of the coherent dendritic network is included in the model. While the thermomechanical model previously outlined (M. M’Hamdi, A. Mo, and C.L. Martin: Metall. Mater. Trans. A, 2002, vol. 33A, pp. 2081-93) has been used to calculate the temperature and velocity fields associated with the thermally induced deformations and shrinkage driven melt flow, the solute conservation equation including both the liquid and a solid volume-averaged velocity is solved in the present study. In modeling examples, the macrosegregation formation caused by mechanically imposed as well as by thermally induced deformations has been calculated. The modeling results for an Al-4 wt pct Cu alloy indicate that even quite small volumetric strains (≈2 pct), which can be associated with thermally induced deformations, can lead to a macroscopic composition variation in the final casting comparable to that resulting from the solidification shrinkage induced melt flow. These results can be explained by the relatively large volumetric viscoplastic deformation in the coherent mush resulting from the applied constitutive model, as well as the relatively large difference in composition for the studied Al-Cu alloy in the solid and liquid phases at high solid fractions at which the deformation takes place.

Modification of surface layers of copper under the action of the volumetric discharge initiated by an avalanche electron beam in nitrogen and CO2 at atmospheric pressure

Science.gov (United States)

Shulepov, M. A.; Akhmadeev, Yu. Kh.; Tarasenko, V. F.; Kolubaeva, Yu. A.; Krysina, O. V.; Kostyrya, I. D.

2011-05-01

The results of experimental investigations of the action of the volumetric discharge initiated by an avalanche electron beam on the surface of copper specimens are presented. The volumetric (diffuse) discharge in nitrogen and CO2 at atmospheric pressure was initiated by applying high voltage pulses of nanosecond duration to a tubular foil cathode. It has been found that the treatment of a copper surface by this type of discharge increases the hardness of the surface layer due to oxidation.

Uranium, Thorium and Potassium concentrations and volumetric heat production rates at the eastern border of the Parana basin

International Nuclear Information System (INIS)

Andrade, Telma C.Q.; Ribeiro, Fernando B.

1997-01-01

Uranium, thorium and potassium concentrations were measured and volumetric heat production rates were calculated for rocks from the exposed basement at the eastern-southeastern border of the Parana Basin between 23 deg S and 32 deg S. Heat generating element concentration data available in the literature were also used when possible, for volumetric heat production calculations. The uranium concentrations vary from below determination limit (0.51 ppm) and 16 ppm whereas the thorium concentrations vary from below the determination limit (1.26 ppm) and 68 ppm, and K concentrations vary between 0.08% and 5.6%. Volumetric heat production rates vary between 0.07 μW/m 3 to 6.2 μW/m 3 , and the obtained results show a variable heat generation rate with high heat producing bodies scattered along this Parana Basin border. The higher observed values concentrate in the Ribeira fold belt at about 23 deg S and between 30 deg S and 32 deg S in the Down Feliciano fold belt. Isolated high heat production rates can also be observed between 26 deg S and 28 deg S. (author). 11 refs., 3 tabs

Experimental study of the density of the helium-nitrogen gas system at low temperatures.

Science.gov (United States)

Milyutin, V. A.

2017-11-01

At the Department of TOT, an experimental setup was created to measure the density of a binary gas system from 100 to 300 K and pressures up to 16 MPa and with any mixture compositions. Experimental density for the helium-nitrogen system were determined by the piezometer of constant volume method. The amount of substance in the piezometer was measured by volumetric method. In this setup, the mixture of He - N2 was prepared in a special mixer for a series of p-v-T experiments, the concentration was determined by calculation using the equations of state of pure components. In the experiment, mixtures were prepared with molar concentrations, lying close to the range: 0.2, 0.4, 0.6 and 0.8.

Experimental determination of thermodynamic equilibrium in biocatalytic transamination.

Science.gov (United States)

Tufvesson, Pär; Jensen, Jacob S; Kroutil, Wolfgang; Woodley, John M

2012-08-01

The equilibrium constant is a critical parameter for making rational design choices in biocatalytic transamination for the synthesis of chiral amines. However, very few reports are available in the scientific literature determining the equilibrium constant (K) for the transamination of ketones. Various methods for determining (or estimating) equilibrium have previously been suggested, both experimental as well as computational (based on group contribution methods). However, none of these were found suitable for determining the equilibrium constant for the transamination of ketones. Therefore, in this communication we suggest a simple experimental methodology which we hope will stimulate more accurate determination of thermodynamic equilibria when reporting the results of transaminase-catalyzed reactions in order to increase understanding of the relationship between substrate and product molecular structure on reaction thermodynamics. Copyright © 2012 Wiley Periodicals, Inc.

Experimental Determination of Temperatures in a Liquid GAP

International Nuclear Information System (INIS)

Masson, Viviana; Ojeda, Andres; Fabian, Bonetto

2003-01-01

An experimental study of heat transfer in a gap of water at atmospheric pressure is presented under natural convection conditions.The objective of the work was to experimentally determine the expected maximum temperatures in the gap for a given heater power.The experimental set-up was a plane surface heated by resistances and facing a 1mm-liquid gap.Visualisation of phenomena by video and still picture was performed

Volumetric image processing: A new technique for three-dimensional imaging

International Nuclear Information System (INIS)

Fishman, E.K.; Drebin, B.; Magid, D.; St Ville, J.A.; Zerhouni, E.A.; Siegelman, S.S.; Ney, D.R.

1986-01-01

Volumetric three-dimensional (3D) image processing was performed on CT scans of 25 normal hips, and image quality and potential diagnostic applications were assessed. In contrast to surface detection 3D techniques, volumetric processing preserves every pixel of transaxial CT data, replacing the gray scale with transparent ''gels'' and shading. Anatomically, accurate 3D images can be rotated and manipulated in real time, including simulated tissue layer ''peeling'' and mock surgery or disarticulation. This pilot study suggests that volumetric rendering is a major advance in signal processing of medical image data, producing a high quality, uniquely maneuverable image that is useful for fracture interpretation, soft-tissue analysis, surgical planning, and surgical rehearsal

Experimental determination of Ramsey numbers.

Science.gov (United States)

Bian, Zhengbing; Chudak, Fabian; Macready, William G; Clark, Lane; Gaitan, Frank

2013-09-27

Ramsey theory is a highly active research area in mathematics that studies the emergence of order in large disordered structures. Ramsey numbers mark the threshold at which order first appears and are extremely difficult to calculate due to their explosive rate of growth. Recently, an algorithm that can be implemented using adiabatic quantum evolution has been proposed that calculates the two-color Ramsey numbers R(m,n). Here we present results of an experimental implementation of this algorithm and show that it correctly determines the Ramsey numbers R(3,3) and R(m,2) for 4≤m≤8. The R(8,2) computation used 84 qubits of which 28 were computational qubits. This computation is the largest experimental implementation of a scientifically meaningful adiabatic evolution algorithm that has been done to date.

Characteristics of the FTU scrape-off layer (SOL) determined by a simple 1-D model

International Nuclear Information System (INIS)

Ferro, C.

1994-12-01

A simple 1-D model analytical model has been developed to determine the SOL characteristics from the parameters of the main plasma. The solutions are compared with FTU experimental data. The solutions fit quite well the experimental data and their trend. Moreover the model suggests the presence of a critical density related to the non isothermal power flux and the corresponding maximum power which can be safely removed by volumetric sinks. Differences between a limiter-like configuration and a divertor-like configuration are described

Volumetric image interpretation in radiology: scroll behavior and cognitive processes.

Science.gov (United States)

den Boer, Larissa; van der Schaaf, Marieke F; Vincken, Koen L; Mol, Chris P; Stuijfzand, Bobby G; van der Gijp, Anouk

2018-05-16

The interpretation of medical images is a primary task for radiologists. Besides two-dimensional (2D) images, current imaging technologies allow for volumetric display of medical images. Whereas current radiology practice increasingly uses volumetric images, the majority of studies on medical image interpretation is conducted on 2D images. The current study aimed to gain deeper insight into the volumetric image interpretation process by examining this process in twenty radiology trainees who all completed four volumetric image cases. Two types of data were obtained concerning scroll behaviors and think-aloud data. Types of scroll behavior concerned oscillations, half runs, full runs, image manipulations, and interruptions. Think-aloud data were coded by a framework of knowledge and skills in radiology including three cognitive processes: perception, analysis, and synthesis. Relating scroll behavior to cognitive processes showed that oscillations and half runs coincided more often with analysis and synthesis than full runs, whereas full runs coincided more often with perception than oscillations and half runs. Interruptions were characterized by synthesis and image manipulations by perception. In addition, we investigated relations between cognitive processes and found an overall bottom-up way of reasoning with dynamic interactions between cognitive processes, especially between perception and analysis. In sum, our results highlight the dynamic interactions between these processes and the grounding of cognitive processes in scroll behavior. It suggests, that the types of scroll behavior are relevant to describe how radiologists interact with and manipulate volumetric images.

Volumetric segmentation of ADC maps and utility of standard deviation as measure of tumor heterogeneity in soft tissue tumors.

Science.gov (United States)

Singer, Adam D; Pattany, Pradip M; Fayad, Laura M; Tresley, Jonathan; Subhawong, Ty K

2016-01-01

Determine interobserver concordance of semiautomated three-dimensional volumetric and two-dimensional manual measurements of apparent diffusion coefficient (ADC) values in soft tissue masses (STMs) and explore standard deviation (SD) as a measure of tumor ADC heterogeneity. Concordance correlation coefficients for mean ADC increased with more extensive sampling. Agreement on the SD of tumor ADC values was better for large regions of interest and multislice methods. Correlation between mean and SD ADC was low, suggesting that these parameters are relatively independent. Mean ADC of STMs can be determined by volumetric quantification with high interobserver agreement. STM heterogeneity merits further investigation as a potential imaging biomarker that complements other functional magnetic resonance imaging parameters. Copyright © 2016 Elsevier Inc. All rights reserved.

Dual-gated volumetric modulated arc therapy

International Nuclear Information System (INIS)

Fahimian, Benjamin; Wu, Junqing; Wu, Huanmei; Geneser, Sarah; Xing, Lei

2014-01-01

Gated Volumetric Modulated Arc Therapy (VMAT) is an emerging radiation therapy modality for treatment of tumors affected by respiratory motion. However, gating significantly prolongs the treatment time, as delivery is only activated during a single respiratory phase. To enhance the efficiency of gated VMAT delivery, a novel dual-gated VMAT (DG-VMAT) technique, in which delivery is executed at both exhale and inhale phases in a given arc rotation, is developed and experimentally evaluated. Arc delivery at two phases is realized by sequentially interleaving control points consisting of MUs, MLC sequences, and angles of VMAT plans generated at the exhale and inhale phases. Dual-gated delivery is initiated when a respiration gating signal enters the exhale window; when the exhale delivery concludes, the beam turns off and the gantry rolls back to the starting position for the inhale window. The process is then repeated until both inhale and exhale arcs are fully delivered. DG-VMAT plan delivery accuracy was assessed using a pinpoint chamber and diode array phantom undergoing programmed motion. DG-VMAT delivery was experimentally implemented through custom XML scripting in Varian’s TrueBeam™ STx Developer Mode. Relative to single gated delivery at exhale, the treatment time was improved by 95.5% for a sinusoidal breathing pattern. The pinpoint chamber dose measurement agreed with the calculated dose within 0.7%. For the DG-VMAT delivery, 97.5% of the diode array measurements passed the 3%/3 mm gamma criterion. The feasibility of DG-VMAT delivery scheme has been experimentally demonstrated for the first time. By leveraging the stability and natural pauses that occur at end-inspiration and end-exhalation, DG-VMAT provides a practical method for enhancing gated delivery efficiency by up to a factor of two

Three-dimensional volumetric display by inclined-plane scanning

Science.gov (United States)

Miyazaki, Daisuke; Eto, Takuma; Nishimura, Yasuhiro; Matsushita, Kenji

2003-05-01

A volumetric display system based on three-dimensional (3-D) scanning that uses an inclined two-dimensional (2-D) image is described. In the volumetric display system a 2-D display unit is placed obliquely in an imaging system into which a rotating mirror is inserted. When the mirror is rotated, the inclined 2-D image is moved laterally. A locus of the moving image can be observed by persistence of vision as a result of the high-speed rotation of the mirror. Inclined cross-sectional images of an object are displayed on the display unit in accordance with the position of the image plane to observe a 3-D image of the object by persistence of vision. Three-dimensional images formed by this display system satisfy all the criteria for stereoscopic vision. We constructed the volumetric display systems using a galvanometer mirror and a vector-scan display unit. In addition, we constructed a real-time 3-D measurement system based on a light section method. Measured 3-D images can be reconstructed in the 3-D display system in real time.

Tracking Ionic Rearrangements and Interpreting Dynamic Volumetric Changes in Two-Dimensional Metal Carbide Supercapacitors: A Molecular Dynamics Simulation Study.

Science.gov (United States)

Xu, Kui; Lin, Zifeng; Merlet, Céline; Taberna, Pierre-Louis; Miao, Ling; Jiang, Jianjun; Simon, Patrice

2017-12-06

We present a molecular dynamics simulation study achieved on two-dimensional (2D) Ti 3 C 2 T x MXenes in the ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([EMIM] + [TFSI] - ) electrolyte. Our simulations reproduce the different patterns of volumetric change observed experimentally for both the negative and positive electrodes. The analysis of ionic fluxes and structure rearrangements in the 2D material provide an atomic scale insight into the charge and discharge processes in the layer pore and confirm the existence of two different charge-storage mechanisms at the negative and positive electrodes. The ionic number variation and the structure rearrangement contribute to the dynamic volumetric changes of both electrodes: negative electrode expansion and positive electrode contraction. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Operating scheme for the light-emitting diode array of a volumetric display that exhibits multiple full-color dynamic images

Science.gov (United States)

Hirayama, Ryuji; Shiraki, Atsushi; Nakayama, Hirotaka; Kakue, Takashi; Shimobaba, Tomoyoshi; Ito, Tomoyoshi

2017-07-01

We designed and developed a control circuit for a three-dimensional (3-D) light-emitting diode (LED) array to be used in volumetric displays exhibiting full-color dynamic 3-D images. The circuit was implemented on a field-programmable gate array; therefore, pulse-width modulation, which requires high-speed processing, could be operated in real time. We experimentally evaluated the developed system by measuring the luminance of an LED with varying input and confirmed that the system works appropriately. In addition, we demonstrated that the volumetric display exhibits different full-color dynamic two-dimensional images in two orthogonal directions. Each of the exhibited images could be obtained only from the prescribed viewpoint. Such directional characteristics of the system are beneficial for applications, including digital signage, security systems, art, and amusement.

Dose-volumetric parameters for predicting hypothyroidism after radiotherapy for head and neck cancer

International Nuclear Information System (INIS)

Kim, Mi Young; Yu, Tosol; Wu, Hong-Gyun

2014-01-01

To investigate predictors affecting the development of hypothyroidism after radiotherapy for head and neck cancer, focusing on radiation dose-volumetric parameters, and to determine the appropriate radiation dose-volumetric threshold of radiation-induced hypothyroidism. A total of 114 patients with head and neck cancer whose radiotherapy fields included the thyroid gland were analysed. The purpose of the radiotherapy was either definitive (n=81) or post-operative (n=33). Thyroid function was monitored before starting radiotherapy and after completion of radiotherapy at 1 month, 6 months, 1 year and 2 years. A diagnosis of hypothyroidism was based on a thyroid stimulating hormone value greater than the maximum value of laboratory range, regardless of symptoms. In all patients, dose volumetric parameters were analysed. Median follow-up duration was 25 months (range; 6-38). Forty-six percent of the patients were diagnosed as hypothyroidism after a median time of 8 months (range; 1-24). There were no significant differences in the distribution of age, gender, surgery, radiotherapy technique and chemotherapy between the euthyroid group and the hypothyroid group. In univariate analysis, the mean dose and V35-V50 results were significantly associated with hypothyroidism. The V45 is the only variable that independently contributes to the prediction of hypothyroidism in multivariate analysis and V45 of 50% was a threshold value. If V45 was <50%, the cumulative incidence of hypothyroidism at 1 year was 22.8%, whereas the incidence was 56.1% if V45 was ≥50%. (P=0.034). The V45 may predict risk of developing hypothyroidism after radiotherapy for head and neck cancer, and a V45 of 50% can be a useful dose-volumetric threshold of radiation-induced hypothyroidism. (author)

WE-G-BRF-04: Robust Real-Time Volumetric Imaging Based On One Single Projection

International Nuclear Information System (INIS)

Xu, Y; Yan, H; Ouyang, L; Wang, J; Jiang, S; Jia, X; Zhou, L

2014-01-01

Purpose: Real-time volumetric imaging is highly desirable to provide instantaneous image guidance for lung radiation therapy. This study proposes a scheme to achieve this goal using one single projection by utilizing sparse learning and a principal component analysis (PCA) based lung motion model. Methods: A patient-specific PCA-based lung motion model is first constructed by analyzing deformable vector fields (DVFs) between a reference image and 4DCT images at each phase. At the training stage, we “learn” the relationship between the DVFs and the projection using sparse learning. Specifically, we first partition the projections into patches, and then apply sparse learning to automatically identify patches that best correlate with the principal components of the DVFs. Once the relationship is established, at the application stage, we first employ a patchbased intensity correction method to overcome the problem of different intensity scale between the calculated projection in the training stage and the measured projection in the application stage. The corrected projection image is then fed to the trained model to derive a DVF, which is applied to the reference image, yielding a volumetric image corresponding to the projection. We have validated our method through a NCAT phantom simulation case and one experiment case. Results: Sparse learning can automatically select those patches containing motion information, such as those around diaphragm. For the simulation case, over 98% of the lung region pass the generalized gamma test (10HU/1mm), indicating combined accuracy in both intensity and spatial domain. For the experimental case, the average tumor localization errors projected to the imager are 0.68 mm and 0.4 mm on the axial and tangential direction, respectively. Conclusion: The proposed method is capable of accurately generating a volumetric image using one single projection. It will potentially offer real-time volumetric image guidance to facilitate lung

WE-G-BRF-04: Robust Real-Time Volumetric Imaging Based On One Single Projection

Energy Technology Data Exchange (ETDEWEB)

Xu, Y [UT Southwestern Medical Center, Dallas, TX (United States); Southern Medical University, Guangzhou (China); Yan, H; Ouyang, L; Wang, J; Jiang, S; Jia, X [UT Southwestern Medical Center, Dallas, TX (United States); Zhou, L [Southern Medical University, Guangzhou (China)

2014-06-15

Purpose: Real-time volumetric imaging is highly desirable to provide instantaneous image guidance for lung radiation therapy. This study proposes a scheme to achieve this goal using one single projection by utilizing sparse learning and a principal component analysis (PCA) based lung motion model. Methods: A patient-specific PCA-based lung motion model is first constructed by analyzing deformable vector fields (DVFs) between a reference image and 4DCT images at each phase. At the training stage, we “learn” the relationship between the DVFs and the projection using sparse learning. Specifically, we first partition the projections into patches, and then apply sparse learning to automatically identify patches that best correlate with the principal components of the DVFs. Once the relationship is established, at the application stage, we first employ a patchbased intensity correction method to overcome the problem of different intensity scale between the calculated projection in the training stage and the measured projection in the application stage. The corrected projection image is then fed to the trained model to derive a DVF, which is applied to the reference image, yielding a volumetric image corresponding to the projection. We have validated our method through a NCAT phantom simulation case and one experiment case. Results: Sparse learning can automatically select those patches containing motion information, such as those around diaphragm. For the simulation case, over 98% of the lung region pass the generalized gamma test (10HU/1mm), indicating combined accuracy in both intensity and spatial domain. For the experimental case, the average tumor localization errors projected to the imager are 0.68 mm and 0.4 mm on the axial and tangential direction, respectively. Conclusion: The proposed method is capable of accurately generating a volumetric image using one single projection. It will potentially offer real-time volumetric image guidance to facilitate lung

Model of large volumetric capacitance in graphene supercapacitors based on ion clustering

Science.gov (United States)

Skinner, Brian; Fogler, M. M.; Shklovskii, B. I.

2011-12-01

Electric double-layer supercapacitors (SCs) are promising devices for high-power energy storage based on the reversible absorption of ions into porous conducting electrodes. Graphene is a particularly good candidate for the electrode material in SCs due to its high conductivity and large surface area. In this paper, we consider SC electrodes made from a stack of graphene sheets with randomly inserted spacer molecules. We show that the large volumetric capacitances C≳100F/cm3 observed experimentally can be understood as a result of collective intercalation of ions into the graphene stack and the accompanying nonlinear screening by graphene electrons that renormalizes the charge of the ion clusters.

Volumetric, dashboard-mounted augmented display

Science.gov (United States)

Kessler, David; Grabowski, Christopher

2017-11-01

The optical design of a compact volumetric display for drivers is presented. The system displays a true volume image with realistic physical depth cues, such as focal accommodation, parallax and convergence. A large eyebox is achieved with a pupil expander. The windshield is used as the augmented reality combiner. A freeform windshield corrector is placed at the dashboard.

Predicting Soil-Water Characteristics from Volumetric Contents of Pore-Size Analogue Particle Fractions

DEFF Research Database (Denmark)

Naveed, Muhammad; Møldrup, Per; Tuller, Markus

*-model) for the SWC, derived from readily available soil properties such as texture and bulk density. A total of 46 soils from different horizons at 15 locations across Denmark were used for models evaluation. The Xw-model predicts the volumetric water content as a function of volumetric fines content (organic matter...... and clay). It performed reasonably well for the dry-end (above a pF value of 2.0; pF = log(|Ψ|), where Ψ is the matric potential in cm), but did not do as well closer to saturated conditions. The Xw*-model gives the volumetric water content as a function of volumetric content of particle size fractions...... (organic matter, clay, silt, fine and coarse sand), variably included in the model depending on the pF value. The volumetric content of a particular soil particle size fraction was included in the model if it was assumed to contribute to the pore size fraction still occupied with water at the given p...

Semi-automated volumetric analysis of artificial lymph nodes in a phantom study

International Nuclear Information System (INIS)

Fabel, M.; Biederer, J.; Jochens, A.; Bornemann, L.; Soza, G.; Heller, M.; Bolte, H.

2011-01-01

Purpose: Quantification of tumour burden in oncology requires accurate and reproducible image evaluation. The current standard is one-dimensional measurement (e.g. RECIST) with inherent disadvantages. Volumetric analysis is discussed as an alternative for therapy monitoring of lung and liver metastases. The aim of this study was to investigate the accuracy of semi-automated volumetric analysis of artificial lymph node metastases in a phantom study. Materials and methods: Fifty artificial lymph nodes were produced in a size range from 10 to 55 mm; some of them enhanced using iodine contrast media. All nodules were placed in an artificial chest phantom (artiCHEST ® ) within different surrounding tissues. MDCT was performed using different collimations (1–5 mm) at varying reconstruction kernels (B20f, B40f, B60f). Volume and RECIST measurements were performed using Oncology Software (Siemens Healthcare, Forchheim, Germany) and were compared to reference volume and diameter by calculating absolute percentage errors. Results: The software performance allowed a robust volumetric analysis in a phantom setting. Unsatisfying segmentation results were frequently found for native nodules within surrounding muscle. The absolute percentage error (APE) for volumetric analysis varied between 0.01 and 225%. No significant differences were seen between different reconstruction kernels. The most unsatisfactory segmentation results occurred in higher slice thickness (4 and 5 mm). Contrast enhanced lymph nodes showed better segmentation results by trend. Conclusion: The semi-automated 3D-volumetric analysis software tool allows a reliable and convenient segmentation of artificial lymph nodes in a phantom setting. Lymph nodes adjacent to tissue of similar density cause segmentation problems. For volumetric analysis of lymph node metastases in clinical routine a slice thickness of ≤3 mm and a medium soft reconstruction kernel (e.g. B40f for Siemens scan systems) may be a suitable

A volumetric three-dimensional digital light photoactivatable dye display

Science.gov (United States)

Patel, Shreya K.; Cao, Jian; Lippert, Alexander R.

2017-07-01

Volumetric three-dimensional displays offer spatially accurate representations of images with a 360° view, but have been difficult to implement due to complex fabrication requirements. Herein, a chemically enabled volumetric 3D digital light photoactivatable dye display (3D Light PAD) is reported. The operating principle relies on photoactivatable dyes that become reversibly fluorescent upon illumination with ultraviolet light. Proper tuning of kinetics and emission wavelengths enables the generation of a spatial pattern of fluorescent emission at the intersection of two structured light beams. A first-generation 3D Light PAD was fabricated using the photoactivatable dye N-phenyl spirolactam rhodamine B, a commercial picoprojector, an ultraviolet projector and a custom quartz imaging chamber. The system displays a minimum voxel size of 0.68 mm3, 200 μm resolution and good stability over repeated `on-off' cycles. A range of high-resolution 3D images and animations can be projected, setting the foundation for widely accessible volumetric 3D displays.

Full-spectrum volumetric solar thermal conversion via photonic nanofluids.

Science.gov (United States)

Liu, Xianglei; Xuan, Yimin

2017-10-12

Volumetric solar thermal conversion is an emerging technique for a plethora of applications such as solar thermal power generation, desalination, and solar water splitting. However, achieving broadband solar thermal absorption via dilute nanofluids is still a daunting challenge. In this work, full-spectrum volumetric solar thermal conversion is demonstrated over a thin layer of the proposed 'photonic nanofluids'. The underlying mechanism is found to be the photonic superposition of core resonances, shell plasmons, and core-shell resonances at different wavelengths, whose coexistence is enabled by the broken symmetry of specially designed composite nanoparticles, i.e., Janus nanoparticles. The solar thermal conversion efficiency can be improved by 10.8% compared with core-shell nanofluids. The extinction coefficient of Janus dimers with various configurations is also investigated to unveil the effects of particle couplings. This work provides the possibility to achieve full-spectrum volumetric solar thermal conversion, and may have potential applications in efficient solar energy harvesting and utilization.

SU-F-J-47: Inherent Uncertainty in the Positional Shifts Determined by a Volumetric Cone Beam Imaging System

International Nuclear Information System (INIS)

Giri, U; Ganesh, T; Saini, V; Munshi, A; Sarkar, B; Mohanti, B

2016-01-01

Purpose: To quantify inherent uncertainty associated with a volumetric imaging system in its determination of positional shifts. Methods: The study was performed on an Elekta Axesse™ linac’s XVI cone beam computed tomography (CBCT) system. A CT image data set of a Penta- Guide phantom was used as reference image by placing isocenter at the center of the phantom.The phantom was placed arbitrarily on the couch close to isocenter and CBCT images were obtained. The CBCT dataset was matched with the reference image using XVI software and the shifts were determined in 6-dimensions. Without moving the phantom, this process was repeated 20 times consecutively within 30 minutes on a single day. Mean shifts and their standard deviations in all 6-dimensions were determined for all the 20 instances of imaging. For any given day, the first set of shifts obtained was kept as reference and the deviations of the subsequent 19 sets from the reference set were scored. Mean differences and their standard deviations were determined. In this way, data were obtained for 30 consecutive working days. Results: Tabulating the mean deviations and their standard deviations observed on each day for the 30 measurement days, systematic and random errors in the determination of shifts by XVI software were calculated. The systematic errors were found to be 0.03, 0.04 and 0.03 mm while random errors were 0.05, 0.06 and 0.06 mm in lateral, craniocaudal and anterio-posterior directions respectively. For rotational shifts, the systematic errors were 0.02°, 0.03° and 0.03° and random errors were 0.06°, 0.05° and 0.05° in pitch, roll and yaw directions respectively. Conclusion: The inherent uncertainties in every image guidance system should be assessed and baseline values established at the time of its commissioning. These shall be periodically tested as part of the QA protocol.

System analysis of formation and perception processes of three-dimensional images in volumetric displays

Science.gov (United States)

Bolshakov, Alexander; Sgibnev, Arthur

2018-03-01

One of the promising devices is currently a volumetric display. Volumetric displays capable to visualize complex three-dimensional information as nearly as possible to its natural – volume form without the use of special glasses. The invention and implementation of volumetric display technology will expand opportunities of information visualization in various spheres of human activity. The article attempts to structure and describe the interrelation of the essential characteristics of objects in the area of volumetric visualization. Also there is proposed a method of calculation of estimate total number of voxels perceived by observers during the 3D demonstration, generated using a volumetric display with a rotating screen. In the future, it is planned to expand the described technique and implement a system for estimation the quality of generated images, depending on the types of biplanes and their initial characteristics.

Increasing the volumetric efficiency of Diesel engines by intake pipes

Science.gov (United States)

List, Hans

1933-01-01

Development of a method for calculating the volumetric efficiency of piston engines with intake pipes. Application of this method to the scavenging pumps of two-stroke-cycle engines with crankcase scavenging and to four-stroke-cycle engines. The utility of the method is demonstrated by volumetric-efficiency tests of the two-stroke-cycle engines with crankcase scavenging. Its practical application to the calculation of intake pipes is illustrated by example.

Volumetric Arterial Wall Shear Stress Calculation Based on Cine Phase Contrast MRI

NARCIS (Netherlands)

Potters, Wouter V.; van Ooij, Pim; Marquering, Henk; VanBavel, Ed; Nederveen, Aart J.

2015-01-01

PurposeTo assess the accuracy and precision of a volumetric wall shear stress (WSS) calculation method applied to cine phase contrast magnetic resonance imaging (PC-MRI) data. Materials and MethodsVolumetric WSS vectors were calculated in software phantoms. WSS algorithm parameters were optimized

Experimental investigation of the MSFR molten salt reactor concept

Energy Technology Data Exchange (ETDEWEB)

Yamaji, Bogdan; Aszodi, Attila [Budapest University of Technology and Economics (Hungary). Inst. of Nuclear Techniques

2014-11-15

In the paper experimental modelling and investigation of the MSFR concept will be presented. MSFR is a homogeneous, single region liquid fuelled fast reactor concept. In case of molten salt reactors the core neutron flux and fission distribution is determined by the flow field through distribution and transport of fissile material and delayed neutron precursors. Since the MSFR core is a single region homogeneous volume without internal structures, it is a difficult task to ensure stable flow field, which is strongly coupled to the volumetric heat generation. These considerations suggest that experimental modelling would greatly help to understand the flow phenomena in such geometry. A scaled and segmented experimental mock-up of MSFR was designed and built in order to carry out particle image velocimetry measurements. Basic flow behaviour inside the core region can be investigated and the measurement data can also provide resource for the validation of computational fluid dynamics models. Measurement results of steady state conditions will be presented and discussed.

Tandem Gravimetric and Volumetric Apparatus for Methane Sorption Measurements

Science.gov (United States)

Burress, Jacob; Bethea, Donald

Concerns about global climate change have driven the search for alternative fuels. Natural gas (NG, methane) is a cleaner fuel than gasoline and abundantly available due to hydraulic fracturing. One hurdle to the adoption of NG vehicles is the bulky cylindrical storage vessels needed to store the NG at high pressures (3600 psi, 250 bar). The adsorption of methane in microporous materials can store large amounts of methane at low enough pressures for the allowance of conformable, ``flat'' pressure vessels. The measurement of the amount of gas stored in sorbent materials is typically done by measuring pressure differences (volumetric, manometric) or masses (gravimetric). Volumetric instruments of the Sievert type have uncertainties that compound with each additional measurement. Therefore, the highest-pressure measurement has the largest uncertainty. Gravimetric instruments don't have that drawback, but can have issues with buoyancy corrections. An instrument will be presented with which methane adsorption measurements can be performed using both volumetric and gravimetric methods in tandem. The gravimetric method presented has no buoyancy corrections and low uncertainty. Therefore, the gravimetric measurements can be performed throughout an entire isotherm or just at the extrema to verify the results from the volumetric measurements. Results from methane sorption measurements on an activated carbon (MSC-30) and a metal-organic framework (Cu-BTC, HKUST-1, MOF-199) will be shown. New recommendations for calculations of gas uptake and uncertainty measurements will be discussed.

Experimental studies of direct contact heat transfer in a slurry bubble column at high gas temperature of a helium–water–alumina system

International Nuclear Information System (INIS)

Abdulrahman, M.W.

2015-01-01

In this paper, the direct contact heat transfer is investigated experimentally for a helium gas at 90 °C injected through a slurry of water at 22 °C and alumina solid particles in a slurry bubble column reactor. This work examines the effects of superficial gas velocity, static liquid height, solid particles concentration and solid particle size, on the volumetric heat transfer coefficient and slurry temperature of the slurry bubble column reactor. These effects are formulated in forms of empirical equations. From the experimental work, it is found that the volumetric heat transfer coefficient and the slurry temperature increase by increasing the superficial gas velocity with a higher rate of increase at lower superficial gas velocity. In addition, the volumetric heat transfer coefficient and the slurry temperature decrease by increasing the static liquid height and/or the solid concentration at any given superficial gas velocity. Furthermore, it is found that the rate of decrease of the volumetric heat transfer coefficient with the solid concentration is approximately the same for different superficial gas velocities, and the decrease of the slurry temperature with the solid concentration is negligible. - Highlights: • Direct contact heat transfer is investigated experimentally in a slurry bubble column. • Empirical equation of direct contact heat transfer Nusselt number is formulated. • The volumetric heat transfer coefficient increases with superficial gas velocity. • The volumetric heat transfer coefficient decreases with the static liquid height. • The volumetric heat transfer coefficient decreases with the solid concentration.

Automated volumetric breast density estimation: A comparison with visual assessment

International Nuclear Information System (INIS)

Seo, J.M.; Ko, E.S.; Han, B.-K.; Ko, E.Y.; Shin, J.H.; Hahn, S.Y.

2013-01-01

Aim: To compare automated volumetric breast density (VBD) measurement with visual assessment according to Breast Imaging Reporting and Data System (BI-RADS), and to determine the factors influencing the agreement between them. Materials and methods: One hundred and ninety-three consecutive screening mammograms reported as negative were included in the study. Three radiologists assigned qualitative BI-RADS density categories to the mammograms. An automated volumetric breast-density method was used to measure VBD (% breast density) and density grade (VDG). Each case was classified into an agreement or disagreement group according to the comparison between visual assessment and VDG. The correlation between visual assessment and VDG was obtained. Various physical factors were compared between the two groups. Results: Agreement between visual assessment by the radiologists and VDG was good (ICC value = 0.757). VBD showed a highly significant positive correlation with visual assessment (Spearman's ρ = 0.754, p < 0.001). VBD and the x-ray tube target was significantly different between the agreement group and the disagreement groups (p = 0.02 and 0.04, respectively). Conclusion: Automated VBD is a reliable objective method to measure breast density. The agreement between VDG and visual assessment by radiologist might be influenced by physical factors

A new method for calculating volumetric sweeps efficiency using streamline simulation concepts

International Nuclear Information System (INIS)

Hidrobo, E A

2000-01-01

One of the purposes of reservoir engineering is to quantify the volumetric sweep efficiency for optimizing reservoir management decisions. The estimation of this parameter has always been a difficult task. Until now, sweep efficiency correlations and calculations have been limited to mostly homogeneous 2-D cases. Calculating volumetric sweep efficiency in a 3-D heterogeneous reservoir becomes difficult due to inherent complexity of multiple layers and arbitrary well configurations. In this paper, a new method for computing volumetric sweep efficiency for any arbitrary heterogeneity and well configuration is presented. The proposed method is based on Datta-Gupta and King's formulation of streamline time-of-flight (1995). Given the fact that the time-of-flight reflects the fluid front propagation at various times, then the connectivity in the time-of-flight represents a direct measure of the volumetric sweep efficiency. The proposed approach has been applied to synthetic as well as field examples. Synthetic examples are used to validate the volumetric sweep efficiency calculations using the streamline time-of-flight connectivity criterion by comparison with analytic solutions and published correlations. The field example, which illustrates the feasibility of the approach for large-scale field applications, is from the north Robertson unit, a low permeability carbonate reservoir in west Texas

SPECTROPHOTOMETRIC DETERMINATION OF PIZOTEFIN ...

African Journals Online (AJOL)

B. S. Chandravanshi

respectively. Different experimental conditions for the two methods were optimized. Beer's law was obeyed in the concentration ranges of .... mixed in various proportions and the volume was diluted in a 10-mL volumetric flask with acetonitrile. The absorbance of the resulting solutions was measured at optimum wavelengths.

Region-of-interest volumetric visual hull refinement

KAUST Repository

Knoblauch, Daniel; Kuester, Falko

2010-01-01

This paper introduces a region-of-interest visual hull refinement technique, based on flexible voxel grids for volumetric visual hull reconstructions. Region-of-interest refinement is based on a multipass process, beginning with a focussed visual

Impact of Turbocharger Non-Adiabatic Operation on Engine Volumetric Efficiency and Turbo Lag

Directory of Open Access Journals (Sweden)

S. Shaaban

2012-01-01

Full Text Available Turbocharger performance significantly affects the thermodynamic properties of the working fluid at engine boundaries and hence engine performance. Heat transfer takes place under all circumstances during turbocharger operation. This heat transfer affects the power produced by the turbine, the power consumed by the compressor, and the engine volumetric efficiency. Therefore, non-adiabatic turbocharger performance can restrict the engine charging process and hence engine performance. The present research work investigates the effect of turbocharger non-adiabatic performance on the engine charging process and turbo lag. Two passenger car turbochargers are experimentally and theoretically investigated. The effect of turbine casing insulation is also explored. The present investigation shows that thermal energy is transferred to the compressor under all circumstances. At high rotational speeds, thermal energy is first transferred to the compressor and latter from the compressor to the ambient. Therefore, the compressor appears to be “adiabatic” at high rotational speeds despite the complex heat transfer processes inside the compressor. A tangible effect of turbocharger non-adiabatic performance on the charging process is identified at turbocharger part load operation. The turbine power is the most affected operating parameter, followed by the engine volumetric efficiency. Insulating the turbine is recommended for reducing the turbine size and the turbo lag.

Experimental and theoretical assessment of flexural properties of hybrid natural fibre composites

DEFF Research Database (Denmark)

Raghavalu Thirumalai, Durai Prabhakaran; Toftegaard, Helmuth Langmaack; Markussen, Christen Malte

2014-01-01

The concept of hybridization of natural fibre composites with synthetic fibres is attracting increasing scientific attention. The present study addresses the flexural properties of hybrid flax/glass/epoxy composites to demonstrate the potential benefits of hybridization. The study covers both...... experimental and theoretical assessments. Composite laminates with different hybrid fibre mixing ratios and different layer configurations were manufactured, and their volumetric composition and flexural properties were measured. The relationship between volume fractions in the composites is shown to be well...... predicted as a function of the hybrid fibre mixing ratio. The flexural modulus of the composites is theoretically assessed by using micromechanical models and laminate theory. The model predictions are compared with the experimentally determined flexural properties. Both approaches show that the flexural...

A model of large volumetric capacitance in graphene supercapacitors based on ion clustering

Science.gov (United States)

Skinner, Brian; Fogler, Michael; Shklovskii, Boris

2012-02-01

Electric double layer supercapacitors are promising devices for high-power energy storage based on the reversible absorption of ions into porous, conducting electrodes. Graphene is a particularly good candidate for the electrode material in supercapacitors due to its high conductivity and large surface area. In this paper we consider supercapacitor electrodes made from a stack of graphene sheets with randomly-inserted ``spacer" molecules. We show that the large volumetric capacitances C > 100 F/cm^3 observed experimentally can be understood as a result of collective intercalation of ions into the graphene stack and the accompanying nonlinear screening by graphene electrons that renormalizes the charge of the ion clusters.

Volumetric 3D display using a DLP projection engine

Science.gov (United States)

Geng, Jason

2012-03-01

In this article, we describe a volumetric 3D display system based on the high speed DLPTM (Digital Light Processing) projection engine. Existing two-dimensional (2D) flat screen displays often lead to ambiguity and confusion in high-dimensional data/graphics presentation due to lack of true depth cues. Even with the help of powerful 3D rendering software, three-dimensional (3D) objects displayed on a 2D flat screen may still fail to provide spatial relationship or depth information correctly and effectively. Essentially, 2D displays have to rely upon capability of human brain to piece together a 3D representation from 2D images. Despite the impressive mental capability of human visual system, its visual perception is not reliable if certain depth cues are missing. In contrast, volumetric 3D display technologies to be discussed in this article are capable of displaying 3D volumetric images in true 3D space. Each "voxel" on a 3D image (analogous to a pixel in 2D image) locates physically at the spatial position where it is supposed to be, and emits light from that position toward omni-directions to form a real 3D image in 3D space. Such a volumetric 3D display provides both physiological depth cues and psychological depth cues to human visual system to truthfully perceive 3D objects. It yields a realistic spatial representation of 3D objects and simplifies our understanding to the complexity of 3D objects and spatial relationship among them.

EXPERIMENTAL DETERMINATION OF JUNG MODULE FOR POLYMER MATERIALS

Directory of Open Access Journals (Sweden)

S. N. Savin

2016-04-01

Full Text Available In the article the method of calculation-experimental determination of the Jung module is offered for standards from materials of different types in form plates long from 40 to 200 mm, width from 5 to 50 mm and in thick 0,5 to 20 mm. For measuring the experimental setting, consisting of hard steel frame was used, set of loads to 4 kg and horizontal microscope. Solution of task of calculation of deformations and tensions in the loaded cantilever plate the finite elements method is offered. For verification of exactness of measurings standards were used from pure metals: aluminium, zinc, copper, and, also, polymethylmethacrylate. For all control standards the certain is experimental value of the Jung module at the small and middle loadings exactly corresponds reference data. For the estimation of influence of contents of powder phisico-mechanical properties of polymeric composites the values of the module were certain Jung module for an epoxypolymers and epoxycomposites with a 50% filling with powder of nickel. It is rotined that conduct 50% metallic contents promotes inflexibility of material more than in 2 times. The offered method does not require the strict sizes of standards, that comfortably for determination of the Jung module of experimental materials, above all things oriented polymeric composites.

Breast Density Estimation with Fully Automated Volumetric Method: Comparison to Radiologists' Assessment by BI-RADS Categories.

Science.gov (United States)

Singh, Tulika; Sharma, Madhurima; Singla, Veenu; Khandelwal, Niranjan

2016-01-01

The objective of our study was to calculate mammographic breast density with a fully automated volumetric breast density measurement method and to compare it to breast imaging reporting and data system (BI-RADS) breast density categories assigned by two radiologists. A total of 476 full-field digital mammography examinations with standard mediolateral oblique and craniocaudal views were evaluated by two blinded radiologists and BI-RADS density categories were assigned. Using a fully automated software, mean fibroglandular tissue volume, mean breast volume, and mean volumetric breast density were calculated. Based on percentage volumetric breast density, a volumetric density grade was assigned from 1 to 4. The weighted overall kappa was 0.895 (almost perfect agreement) for the two radiologists' BI-RADS density estimates. A statistically significant difference was seen in mean volumetric breast density among the BI-RADS density categories. With increased BI-RADS density category, increase in mean volumetric breast density was also seen (P BI-RADS categories and volumetric density grading by fully automated software (ρ = 0.728, P BI-RADS density category by two observers showed fair agreement (κ = 0.398 and 0.388, respectively). In our study, a good correlation was seen between density grading using fully automated volumetric method and density grading using BI-RADS density categories assigned by the two radiologists. Thus, the fully automated volumetric method may be used to quantify breast density on routine mammography. Copyright © 2016 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.

Erosion of water-based cements evaluated by volumetric and gravimetric methods.

Science.gov (United States)

Nomoto, Rie; Uchida, Keiko; Momoi, Yasuko; McCabe, John F

2003-05-01

To compare the erosion of glass ionomer, zinc phosphate and polycarboxylate cements using volumetric and gravimetric methods. For the volumetric method, the eroded depth of cement placed in a cylindrical cavity in PMMA was measured using a dial gauge after immersion in an eroding solution. For the gravimetric method, the weight of the residue of a solution in which a cylindrical specimen had been immersed was measured. 0.02 M lactic acid solution (0.02 M acid) and 0.1 M lactic acid/sodium lactate buffer solution (0.1 M buffer) were used as eroding solutions. The pH of both solutions was 2.74 and the test period was 24 h. Ranking of eroded depth and weight of residue was polycarboxylate>zinc phosphate>glass ionomers. Differences in erosion were more clearly defined by differences in eroded depth than differences in weight of residue. In 0.02 M acid, the erosion of glass ionomer using the volumetric method was effected by the hygroscopic expansion. In 0.1 M buffer, the erosion for polycarboxylate and zinc phosphate using the volumetric method was much greater than that using the gravimetric method. This is explained by cryo-SEM images which show many holes in the surface of specimens after erosion. It appears that zinc oxide is dissolved leaving a spongy matrix which easily collapses under the force applied to the dial gauge during measurement. The volumetric method that employs eroded depth of cement using a 0.1 M buffer solution is able to quantify erosion and to make material comparisons.

DIFFERENTIAL ANALYSIS OF VOLUMETRIC STRAINS IN POROUS MATERIALS IN TERMS OF WATER FREEZING

Directory of Open Access Journals (Sweden)

Rusin Z.

2013-06-01

Full Text Available The paper presents the differential analysis of volumetric strain (DAVS. The method allows measurements of volumetric deformations of capillary-porous materials caused by water-ice phase change. The VSE indicator (volumetric strain effect, which under certain conditions can be interpreted as the minimum degree of phase change of water contained in the material pores, is proposed. The test results (DAVS for three materials with diversified microstructure: clinker brick, calcium-silicate brick and Portland cement mortar were compared with the test results for pore characteristics obtained with the mercury intrusion porosimetry.

Coaxial volumetric velocimetry

Science.gov (United States)

Schneiders, Jan F. G.; Scarano, Fulvio; Jux, Constantin; Sciacchitano, Andrea

2018-06-01

This study describes the working principles of the coaxial volumetric velocimeter (CVV) for wind tunnel measurements. The measurement system is derived from the concept of tomographic PIV in combination with recent developments of Lagrangian particle tracking. The main characteristic of the CVV is its small tomographic aperture and the coaxial arrangement between the illumination and imaging directions. The system consists of a multi-camera arrangement subtending only few degrees solid angle and a long focal depth. Contrary to established PIV practice, laser illumination is provided along the same direction as that of the camera views, reducing the optical access requirements to a single viewing direction. The laser light is expanded to illuminate the full field of view of the cameras. Such illumination and imaging conditions along a deep measurement volume dictate the use of tracer particles with a large scattering area. In the present work, helium-filled soap bubbles are used. The fundamental principles of the CVV in terms of dynamic velocity and spatial range are discussed. Maximum particle image density is shown to limit tracer particle seeding concentration and instantaneous spatial resolution. Time-averaged flow fields can be obtained at high spatial resolution by ensemble averaging. The use of the CVV for time-averaged measurements is demonstrated in two wind tunnel experiments. After comparing the CVV measurements with the potential flow in front of a sphere, the near-surface flow around a complex wind tunnel model of a cyclist is measured. The measurements yield the volumetric time-averaged velocity and vorticity field. The measurements of the streamlines in proximity of the surface give an indication of the skin-friction lines pattern, which is of use in the interpretation of the surface flow topology.

A modified differential scanning calorimetry for determination of cell volumetric change during the freezing process.

Science.gov (United States)

Luo, Dawei; Han, Xu; He, Liqun; Cui, Xiangdong; Cheng, Shuxia; Lu, Caicheng; Liu, Jianghan; Gao, Dayong

2002-01-01

A modified analytical and experimental method using differential scanning calorimeter (DSC) was developed to determine the cell volume change during the freezing process. Two cell types were used in the study: human platelets and erythrocytes (red blood cells). Isotonic cell suspensions with different cytocrits were prepared and used in the DSC experiments. Low cooling rates were used to avoid intracellular ice formation. Cell suspensions were cooled from room temperature to -40 degrees C. Latent heat release from the freezing of cell suspensions was shown to be a linear function of cytocrit. From slope and intercept of the linear function, cell volume change was determined based on a developed theoretical model. From experimental data and theoretical analyses, it was revealed that (a) the final volume of a human platelet at -40 degrees C was 33.7% of its isotonic volume, and 15.2% of the original (at isotonic condition) intracellular water remained unfrozen inside platelets, and (b) the final volume of human erythrocyte at -40 degrees C was 50.0% of its isotonic volume, and 30.3% of the original intracellular water was kept inside cells as residual unfrozen water.

[Automated detection and volumetric segmentation of the spleen in CT scans].

Science.gov (United States)

Hammon, M; Dankerl, P; Kramer, M; Seifert, S; Tsymbal, A; Costa, M J; Janka, R; Uder, M; Cavallaro, A

2012-08-01

To introduce automated detection and volumetric segmentation of the spleen in spiral CT scans with the THESEUS-MEDICO software. The consistency between automated volumetry (aV), estimated volume determination (eV) and manual volume segmentation (mV) was evaluated. Retrospective evaluation of the CAD system based on methods like "marginal space learning" and "boosting algorithms". 3 consecutive spiral CT scans (thoraco-abdominal; portal-venous contrast agent phase; 1 or 5 mm slice thickness) of 15 consecutive lymphoma patients were included. The eV: 30 cm³ + 0.58 (width × length × thickness of the spleen) and the mV as the reference standard were determined by an experienced radiologist. The aV could be performed in all CT scans within 15.2 (± 2.4) seconds. The average splenic volume measured by aV was 268.21 ± 114.67 cm³ compared to 281.58 ± 130.21 cm³ in mV and 268.93 ± 104.60 cm³ in eV. The correlation coefficient was 0.99 (coefficient of determination (R²) = 0.98) for aV and mV, 0.91 (R² = 0.83) for mV and eV and 0.91 (R² = 0.82) for aV and eV. There was an almost perfect correlation of the changes in splenic volume measured with the new aV and mV (0.92; R² = 0.84), mV and eV (0.95; R² = 0.91) and aV and eV (0.83; R² = 0.69) between two time points. The automated detection and volumetric segmentation software rapidly provides an accurate measurement of the splenic volume in CT scans. Knowledge about splenic volume and its change between two examinations provides valuable clinical information without effort for the radiologist. © Georg Thieme Verlag KG Stuttgart · New York.

Automated detection and volumetric segmentation of the spleen in CT scans

International Nuclear Information System (INIS)

Hammon, M.; Dankerl, P.; Janka, R.; Uder, M.; Cavallaro, A.; Kramer, M.; Seifert, S.; Tsymbal, A.; Costa, M.J.

2012-01-01

To introduce automated detection and volumetric segmentation of the spleen in spiral CT scans with the THESEUS-MEDICO software. The consistency between automated volumetry (aV), estimated volume determination (eV) and manual volume segmentation (mV) was evaluated. Retrospective evaluation of the CAD system based on methods like ''marginal space learning'' and ''boosting algorithms''. 3 consecutive spiral CT scans (thoraco-abdominal; portal-venous contrast agent phase; 1 or 5 mm slice thickness) of 15 consecutive lymphoma patients were included. The eV: 30 cm 3 + 0.58 (width x length x thickness of the spleen) and the mV as the reference standard were determined by an experienced radiologist. The aV could be performed in all CT scans within 15.2 (± 2.4) seconds. The average splenic volume measured by aV was 268.21 ± 114.67 cm 3 compared to 281.58 ± 130.21 cm 3 in mV and 268.93 ± 104.60 cm 3 in eV. The correlation coefficient was 0.99 (coefficient of determination (R 2 ) = 0.98) for aV and mV, 0.91 (R 2 = 0.83) for mV and eV and 0.91 (R 2 = 0.82) for aV and eV. There was an almost perfect correlation of the changes in splenic volume measured with the new aV and mV (0.92; R 2 = 0.84), mV and eV (0.95; R 2 = 0.91) and aV and eV (0.83; R 2 = 0.69) between two time points. The automated detection and volumetric segmentation software rapidly provides an accurate measurement of the splenic volume in CT scans. Knowledge about splenic volume and its change between two examinations provides valuable clinical information without effort for the radiologist. (orig.)

Predicting positional error of MLC using volumetric analysis

International Nuclear Information System (INIS)

Hareram, E.S.

2008-01-01

IMRT normally using multiple beamlets (small width of the beam) for a particular field to deliver so that it is imperative to maintain the positional accuracy of the MLC in order to deliver integrated computed dose accurately. Different manufacturers have reported high precession on MLC devices with leaf positional accuracy nearing 0.1 mm but measuring and rectifying the error in this accuracy is very difficult. Various methods are used to check MLC position and among this volumetric analysis is one of the technique. Volumetric approach was adapted in our method using primus machine and 0.6cc chamber at 5 cm depth In perspex. MLC of 1 mm error introduces an error of 20%, more sensitive to other methods

Experimental determination of thermodynamic equilibrium in biocatalytic transamination

DEFF Research Database (Denmark)

Tufvesson, Pär; Jensen, Jacob Skibsted; Kroutil, Wolfgang

2012-01-01

The equilibrium constant is a critical parameter for making rational design choices in biocatalytic transamination for the synthesis of chiral amines. However, very few reports are available in the scientific literature determining the equilibrium constant (K) for the transamination of ketones....... Various methods for determining (or estimating) equilibrium have previously been suggested, both experimental as well as computational (based on group contribution methods). However, none of these were found suitable for determining the equilibrium constant for the transamination of ketones. Therefore...

The relationship between anatomic noise and volumetric breast density for digital mammography

International Nuclear Information System (INIS)

Mainprize, James G.; Tyson, Albert H.; Yaffe, Martin J.

2012-01-01

Purpose: The appearance of parenchymal/stromal patterns in mammography have been characterized as having a Wiener power spectrum with an inverse power-law shape described by the exponential parameter, β. The amount of fibroglandular tissue, which can be quantified in terms of volumetric breast density (VBD), influences the texture and appearance of the patterns formed in a mammogram. Here, a large study is performed to investigate the variations in β in a clinical population and to indicate the relationship between β and breast density. Methods: From a set of 2686 cranio-caudal normal screening mammograms, the parameter β was extracted from log-log fits to the Wiener spectrum over the range 0.15–1 mm −1 . The Wiener spectrum was calculated from regions of interest in the compression paddle contact region of the breast. An in-house computer program, Cumulus V, was used to extract the volumetric breast density and identify the compression paddle contact regions of the breast. The Wiener spectra were calculated with and without modulation transfer function (MTF) correction to determine the impact of VBD on the intrinsic anatomic noise. Results: The mean volumetric breast density was 25.5% (±12.6%) over all images. The mean β following a MTF correction which decreased the β slightly (≈−0.08) was found to be 2.87. Varying the maximum of the spatial frequency range of the fits from 0.7 to 1.0, 1.25 or 1.5 mm −1 showing small decreases in the result, although the effect of the quantum noise power component on reducing β was clearly observed at 1.5 mm −1 . Conclusions: The texture parameter, β, was found to increase with VBD at low volumetric breast densities with an apparent leveling off at higher densities. The relationship between β and VBD measured here can be used to create probabilistic models for computer simulations of detectability. As breast density is a known risk predictor for breast cancer, the correlation between β and VBD suggests that

Stability and Volumetric Properties of Asphalt Mixture Containing Waste Plastic

Directory of Open Access Journals (Sweden)

Abd Kader Siti Aminah

2017-01-01

Full Text Available The objectives of this study are to determine the optimum bitumen content (OBC for every percentage added of waste plastics in asphalt mixtures and to investigate the stability properties of the asphalt mixtures containing waste plastic. Marshall stability and flow values along with density, air voids in total mix, voids in mineral aggregate, and voids filled with bitumen were determined to obtain OBC at different percentages of waste plastic, i.e., 4%, 6%, 8%, and 10% by weight of bitumen as additive. Results showed that the OBC for the plastic-modified asphalt mixtures at 4%, 6%, 8%, and 10% are 4.98, 5.44, 5.48, and 5.14, respectively. On the other hand, the controlled specimen’s shows better volumetric properties compared to plastic mixes. However, 4% additional of waste plastic indicated better stability than controlled specimen.

Comparison of surface contour and volumetric three-dimensional imaging of the musculoskeletal system

International Nuclear Information System (INIS)

Guilford, W.B.; Ullrich, C.G.; Moore, T.

1988-01-01

Both surface contour and volumetric three-dimensional image processing from CT data can provide accurate demonstration of skeletal anatomy. While realistic, surface contour images may obscure fine detail such as nondisplaced fractures, and thin bone may disappear. Volumetric processing can provide high detail, but the transparency effect is unnatural and may yield a confusing image. Comparison of both three-dimensional modes is presented to demonstrate those findings best shown with each and to illustrate helpful techniques to improve volumetric display, such as disarticulation of unnecessary anatomy, short-angle repeating rotation (dithering), and image combination into overlay displays

Simulation of volumetrically heated pebble beds in solid breeding blankets for fusion reactors. Modelling, experimental validation and sensitivity studies

International Nuclear Information System (INIS)

Hernandez Gonzalez, Francisco Alberto

2016-01-01

The Breeder Units contains pebble beds of lithium orthosilicate (Li_4SiO_4) as tritium breeder material and beryllium as neutron multiplier. In this dissertation a closed validation strategy for the thermo-mechanical validation of the Breeder Units has been developed. This strategy is based on the development of dedicated testing and modeling tools, which are needed for the qualification of the thermo-mechanical functionality of these components in an out-of-pile experimental campaign. The neutron flux in the Breeder Units induces a nonhomogeneous volumetric heating in the pebble beds that must be mimicked in an out-of-pile experiment with an external heating system minimizing the intrusion in the pebble beds. Therefore, a heater system that simulates this volumetric heating has been developed. This heater system is based on ohmic heating and linear heater elements, which approximates the point heat sources of the granular material by linear sources. These linear sources represent ''linear pebbles'' in discrete locations close enough to relatively reproduce the thermal gradients occurring in the functional materials. The heater concept has been developed for the Li_4SiO_4 and it is based on a hexagonal matrix arrangement of linear and parallel heater elements of diameter 1 mm separated by 7 mm. A set of uniformly distributed thermocouples in the transversal and longitudinal direction in the pebble bed midplane allows a 2D temperature reconstruction of that measurement plane by means of biharmonic spline interpolation. This heating system has been implemented in a relevant Breeder Unit region and its proof-of-concept has been tested in a PRE-test Mock-Up eXperiment (PREMUX) that has been designed and constructed in the frame of this dissertation. The packing factor of the pebble bed with and without the heating system does not show significant differences, giving an indirect evidence of the low intrusion of the system. Such low intrusion has been confirmed by in

Simulation of volumetrically heated pebble beds in solid breeding blankets for fusion reactors. Modelling, experimental validation and sensitivity studies

Energy Technology Data Exchange (ETDEWEB)

Hernandez Gonzalez, Francisco Alberto

2016-10-14

The Breeder Units contains pebble beds of lithium orthosilicate (Li{sub 4}SiO{sub 4}) as tritium breeder material and beryllium as neutron multiplier. In this dissertation a closed validation strategy for the thermo-mechanical validation of the Breeder Units has been developed. This strategy is based on the development of dedicated testing and modeling tools, which are needed for the qualification of the thermo-mechanical functionality of these components in an out-of-pile experimental campaign. The neutron flux in the Breeder Units induces a nonhomogeneous volumetric heating in the pebble beds that must be mimicked in an out-of-pile experiment with an external heating system minimizing the intrusion in the pebble beds. Therefore, a heater system that simulates this volumetric heating has been developed. This heater system is based on ohmic heating and linear heater elements, which approximates the point heat sources of the granular material by linear sources. These linear sources represent ''linear pebbles'' in discrete locations close enough to relatively reproduce the thermal gradients occurring in the functional materials. The heater concept has been developed for the Li{sub 4}SiO{sub 4} and it is based on a hexagonal matrix arrangement of linear and parallel heater elements of diameter 1 mm separated by 7 mm. A set of uniformly distributed thermocouples in the transversal and longitudinal direction in the pebble bed midplane allows a 2D temperature reconstruction of that measurement plane by means of biharmonic spline interpolation. This heating system has been implemented in a relevant Breeder Unit region and its proof-of-concept has been tested in a PRE-test Mock-Up eXperiment (PREMUX) that has been designed and constructed in the frame of this dissertation. The packing factor of the pebble bed with and without the heating system does not show significant differences, giving an indirect evidence of the low intrusion of the system. Such

40 CFR 80.170 - Volumetric additive reconciliation (VAR), equipment calibration, and recordkeeping requirements.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 16 2010-07-01 2010-07-01 false Volumetric additive reconciliation... ADDITIVES Detergent Gasoline § 80.170 Volumetric additive reconciliation (VAR), equipment calibration, and...) For a facility which uses a gauge to measure the inventory of the detergent storage tank, the total...

Composite Match Index with Application of Interior Deformation Field Measurement from Magnetic Resonance Volumetric Images of Human Tissues

Directory of Open Access Journals (Sweden)

Penglin Zhang

2012-01-01

Full Text Available Whereas a variety of different feature-point matching approaches have been reported in computer vision, few feature-point matching approaches employed in images from nonrigid, nonuniform human tissues have been reported. The present work is concerned with interior deformation field measurement of complex human tissues from three-dimensional magnetic resonance (MR volumetric images. To improve the reliability of matching results, this paper proposes composite match index (CMI as the foundation of multimethod fusion methods to increase the reliability of these various methods. Thereinto, we discuss the definition, components, and weight determination of CMI. To test the validity of the proposed approach, it is applied to actual MR volumetric images obtained from a volunteer’s calf. The main result is consistent with the actual condition.

Laser beams hazards. Experimental determination of a laser ocular lesion threshold

International Nuclear Information System (INIS)

Courant, D.; Court, L.; Gueneau, G.; Bagot, J.D.; Abadie, B.; Brouillet, B.; Laborde, G.; Duchene, A.

1984-10-01

The risks due to the use of laser have called for the definition of exposure limits. The determination of these values requires the knowledge of the physical parameters of exposure and both the anatomical and the physiological properties of the skin and the eye. The parameters of the mechanisms involved in the biological effects of laser beams, the concept of damage criteria and the experimental results found in the literature are first discussed. The main parameter of the beam determining the injury: wavelength, time and the size of the image are then analysed. Some examples of experimental determinations of laser ocular lesion thresholds, carried out on the retinae of the rabbit and the monkey, emphasize, the difficulties met in the determination of the exposure limits. These experiments involve the effect of laser beam in the visible spectrum. Several techniques are compared: a direct ophthalmoscopic observation, a method with fluorescein angiography, a histologic study with light microscopy and an electrophysiological study. The results show that the determination of exposure limits is chiefly a function of the experimental techniques used, the delay of the observation after exposure and the probability of risk selected. The experimental results demonstrate the importance of these parameters and bring into light the uncertainties of the present guidelines [fr

Experimental Determination of Hydraulic Properties of Unsaturated Calcarenites

Science.gov (United States)

Turturro, Antonietta Celeste; Andriani, Gioacchino Francesco; Clementina Caputo, Maria; Maggi, Sabino

2013-04-01

Understanding hydraulic properties is essential in the modeling of flow and solute transport through the vadose zone, to which problems of soil and groundwater pollution are related. The vadose zone, in fact, is of great importance in controlling groundwater recharge and transport of contaminants into and through the subsoil. The aim of this work is to determine experimentally in laboratory the hydraulic properties of unsaturated calcarenites using an approach including petrophysical determinations and methods for measuring water retention. For this purpose, samples of calcarenites belonging to the Calcarenite di Gravina Fm.(Pliocene-early Pleistocene), came from two different quarry districts located in Southern Italy (Canosa di Puglia and Massafra), were utilized. The water retention function, θ(h), which binds the water content, θ, to water potential, h, was determined in the laboratory by means two different experimental methods: the WP4-T psychrometer and the suction table. At last, a simple mathematical equation represented by van Genuchten's model is fitted to the experimental data and the unknown empirical parameters of this model are determined. Textural analysis on thin sections using optical petrographic microscopy and evaluation of total and effective porosity by means of standard geotechnical laboratory tests, mercury intrusion porosimetry and image analysis were also performed. In particular, a comparison between mercury porosimetry data and results of photomicrograph computer analysis through the methods of quantitative stereology was employed for providing pore size distributions. The results of this study identify the relationship between the hydraulic behavior, described by the water retention function, and pore size distribution for the calcarenites that are not easy to hydraulically characterize. This relationship could represent a useful tool to infer the unsaturated hydraulic properties of calcarenites and in general this approach could be

Multi-camera volumetric PIV for the study of jumping fish

Science.gov (United States)

Mendelson, Leah; Techet, Alexandra H.

2018-01-01

Archer fish accurately jump multiple body lengths for aerial prey from directly below the free surface. Multiple fins provide combinations of propulsion and stabilization, enabling prey capture success. Volumetric flow field measurements are crucial to characterizing multi-propulsor interactions during this highly three-dimensional maneuver; however, the fish's behavior also drives unique experimental constraints. Measurements must be obtained in close proximity to the water's surface and in regions of the flow field which are partially-occluded by the fish body. Aerial jump trajectories must also be known to assess performance. This article describes experiment setup and processing modifications to the three-dimensional synthetic aperture particle image velocimetry (SAPIV) technique to address these challenges and facilitate experimental measurements on live jumping fish. The performance of traditional SAPIV algorithms in partially-occluded regions is characterized, and an improved non-iterative reconstruction routine for SAPIV around bodies is introduced. This reconstruction procedure is combined with three-dimensional imaging on both sides of the free surface to reveal the fish's three-dimensional wake, including a series of propulsive vortex rings generated by the tail. In addition, wake measurements from the anal and dorsal fins indicate their stabilizing and thrust-producing contributions as the archer fish jumps.

Volumetric Two-photon Imaging of Neurons Using Stereoscopy (vTwINS)

Science.gov (United States)

Song, Alexander; Charles, Adam S.; Koay, Sue Ann; Gauthier, Jeff L.; Thiberge, Stephan Y.; Pillow, Jonathan W.; Tank, David W.

2017-01-01

Two-photon laser scanning microscopy of calcium dynamics using fluorescent indicators is a widely used imaging method for large scale recording of neural activity in vivo. Here we introduce volumetric Two-photon Imaging of Neurons using Stereoscopy (vTwINS), a volumetric calcium imaging method that employs an elongated, V-shaped point spread function to image a 3D brain volume. Single neurons project to spatially displaced “image pairs” in the resulting 2D image, and the separation distance between images is proportional to depth in the volume. To demix the fluorescence time series of individual neurons, we introduce a novel orthogonal matching pursuit algorithm that also infers source locations within the 3D volume. We illustrate vTwINS by imaging neural population activity in mouse primary visual cortex and hippocampus. Our results demonstrate that vTwINS provides an effective method for volumetric two-photon calcium imaging that increases the number of neurons recorded while maintaining a high frame-rate. PMID:28319111

Non-uniform volumetric structures in Richtmyer-Meshkov flows

NARCIS (Netherlands)

Staniç, M.; McFarland, J.; Stellingwerf, R.F.; Cassibry, J.T.; Ranjan, D.; Bonazza, R.; Greenough, J.A.; Abarzhi, S.I.

2013-01-01

We perform an integrated study of volumetric structures in Richtmyer-Meshkov (RM) flows induced by moderate shocks. Experiments, theoretical analyses, Smoothed Particle Hydrodynamics simulations, and ARES Arbitrary Lagrange Eulerian simulations are employed to analyze RM evolution for fluids with

Volumetric response classification in metastatic solid tumors on MSCT: Initial results in a whole-body setting

International Nuclear Information System (INIS)

Wulff, A.M.; Fabel, M.; Freitag-Wolf, S.; Tepper, M.; Knabe, H.M.; Schäfer, J.P.; Jansen, O.; Bolte, H.

2013-01-01

Purpose: To examine technical parameters of measurement accuracy and differences in tumor response classification using RECIST 1.1 and volumetric assessment in three common metastasis types (lung nodules, liver lesions, lymph node metastasis) simultaneously. Materials and methods: 56 consecutive patients (32 female) aged 41–82 years with a wide range of metastatic solid tumors were examined with MSCT for baseline and follow up. Images were evaluated by three experienced radiologists using manual measurements and semi-automatic lesion segmentation. Institutional ethics review was obtained and all patients gave written informed consent. Data analysis comprised interobserver variability operationalized as coefficient of variation and categorical response classification according to RECIST 1.1 for both manual and volumetric measures. Continuous data were assessed for statistical significance with Wilcoxon signed-rank test and categorical data with Fleiss kappa. Results: Interobserver variability was 6.3% (IQR 4.6%) for manual and 4.1% (IQR 4.4%) for volumetrically obtained sum of relevant diameters (p < 0.05, corrected). 4–8 patients’ response to therapy was classified differently across observers by using volumetry compared to standard manual measurements. Fleiss kappa revealed no significant difference in categorical agreement of response classification between manual (0.7558) and volumetric (0.7623) measurements. Conclusion: Under standard RECIST thresholds there was no advantage of volumetric compared to manual response evaluation. However volumetric assessment yielded significantly lower interobserver variability. This may allow narrower thresholds for volumetric response classification in the future

Volumetric response classification in metastatic solid tumors on MSCT: Initial results in a whole-body setting

Energy Technology Data Exchange (ETDEWEB)

Wulff, A.M., E-mail: a.wulff@rad.uni-kiel.de [Klinik für Diagnostische Radiologie, Arnold-Heller-Straße 3, Haus 23, 24105 Kiel (Germany); Fabel, M. [Klinik für Diagnostische Radiologie, Arnold-Heller-Straße 3, Haus 23, 24105 Kiel (Germany); Freitag-Wolf, S., E-mail: freitag@medinfo.uni-kiel.de [Institut für Medizinische Informatik und Statistik, Brunswiker Str. 10, 24105 Kiel (Germany); Tepper, M., E-mail: m.tepper@rad.uni-kiel.de [Klinik für Diagnostische Radiologie, Arnold-Heller-Straße 3, Haus 23, 24105 Kiel (Germany); Knabe, H.M., E-mail: h.knabe@rad.uni-kiel.de [Klinik für Diagnostische Radiologie, Arnold-Heller-Straße 3, Haus 23, 24105 Kiel (Germany); Schäfer, J.P., E-mail: jp.schaefer@rad.uni-kiel.de [Klinik für Diagnostische Radiologie, Arnold-Heller-Straße 3, Haus 23, 24105 Kiel (Germany); Jansen, O., E-mail: o.jansen@neurorad.uni-kiel.de [Klinik für Diagnostische Radiologie, Arnold-Heller-Straße 3, Haus 23, 24105 Kiel (Germany); Bolte, H., E-mail: hendrik.bolte@ukmuenster.de [Klinik für Nuklearmedizin, Albert-Schweitzer-Campus 1, Gebäude A1, 48149 Münster (Germany)

2013-10-01

Purpose: To examine technical parameters of measurement accuracy and differences in tumor response classification using RECIST 1.1 and volumetric assessment in three common metastasis types (lung nodules, liver lesions, lymph node metastasis) simultaneously. Materials and methods: 56 consecutive patients (32 female) aged 41–82 years with a wide range of metastatic solid tumors were examined with MSCT for baseline and follow up. Images were evaluated by three experienced radiologists using manual measurements and semi-automatic lesion segmentation. Institutional ethics review was obtained and all patients gave written informed consent. Data analysis comprised interobserver variability operationalized as coefficient of variation and categorical response classification according to RECIST 1.1 for both manual and volumetric measures. Continuous data were assessed for statistical significance with Wilcoxon signed-rank test and categorical data with Fleiss kappa. Results: Interobserver variability was 6.3% (IQR 4.6%) for manual and 4.1% (IQR 4.4%) for volumetrically obtained sum of relevant diameters (p < 0.05, corrected). 4–8 patients’ response to therapy was classified differently across observers by using volumetry compared to standard manual measurements. Fleiss kappa revealed no significant difference in categorical agreement of response classification between manual (0.7558) and volumetric (0.7623) measurements. Conclusion: Under standard RECIST thresholds there was no advantage of volumetric compared to manual response evaluation. However volumetric assessment yielded significantly lower interobserver variability. This may allow narrower thresholds for volumetric response classification in the future.

Determination of manganese content in aqueous solutions

International Nuclear Information System (INIS)

Reeder, S.D.; Smith, J.R.

1977-01-01

The three analytical methods used in the hydrogen-to-manganese cross-section ratio measurement were: volumetric determination of manganese, gravimetric analysis of manganous sulfate; and densimetric determination of manganous sulfate

Physiologically based indices of volumetric capnography in patients receiving mechanical ventilation.

Science.gov (United States)

Romero, P V; Lucangelo, U; Lopez Aguilar, J; Fernandez, R; Blanch, L

1997-06-01

Several indices of ventilatory heterogeneity can be identified from the expiratory CO2 partial pressure or CO2 elimination versus volume curves. The aims of this study were: 1) to analyse several computerizable indices of volumetric capnography in order to detect ventilatory disturbances; and 2) to establish the relationship between those indices and respiratory system mechanics in subjects with normal lungs and in patients with acute respiratory distress syndrome (ARDS), both receiving mechanical ventilation. We studied six normal subjects and five patients with early ARDS mechanically ventilated at three levels of tidal volume (VT). Respiratory system mechanics were assessed by end-expiratory and end-inspiratory occlusion methods, respectively. We determined Phase III slopes, Fletcher's efficiency index, Bohr's dead space (VD,Bohr/VT), and the ratio of alveolar ejection volume to tidal volume (VAE/VT) from expiratory capnograms, as a function of expired volume. Differences between normal subjects and ARDS patients were significant both for capnographic and mechanical parameters. Changes in VT significantly altered capnographic indices in normal subjects, but failed to change ventilatory mechanics and VAE/VT in ARDS patients. After adjusting for breathing pattern, VAE/VT exhibited the best correlation with the mechanical parameters. In conclusion, volumetric capnography, and, specifically, the ratio of alveolar ejection volume to tidal volume allows evaluation and monitoring of ventilatory disturbances in patients with adult respiratory distress syndrome.

40 CFR 80.157 - Volumetric additive reconciliation (“VAR”), equipment calibration, and recordkeeping requirements.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 16 2010-07-01 2010-07-01 false Volumetric additive reconciliation (â... ADDITIVES Detergent Gasoline § 80.157 Volumetric additive reconciliation (“VAR”), equipment calibration, and... other comparable VAR supporting documentation. (ii) For a facility which uses a gauge to measure the...

Development of an online radiology case review system featuring interactive navigation of volumetric image datasets using advanced visualization techniques

International Nuclear Information System (INIS)

Yang, Hyun Kyung; Kim, Boh Kyoung; Jung, Ju Hyun; Kang, Heung Sik; Lee, Kyoung Ho; Woo, Hyun Soo; Jo, Jae Min; Lee, Min Hee

2015-01-01

To develop an online radiology case review system that allows interactive navigation of volumetric image datasets using advanced visualization techniques. Our Institutional Review Board approved the use of the patient data and waived the need for informed consent. We determined the following system requirements: volumetric navigation, accessibility, scalability, undemanding case management, trainee encouragement, and simulation of a busy practice. The system comprised a case registry server, client case review program, and commercially available cloud-based image viewing system. In the pilot test, we used 30 cases of low-dose abdomen computed tomography for the diagnosis of acute appendicitis. In each case, a trainee was required to navigate through the images and submit answers to the case questions. The trainee was then given the correct answers and key images, as well as the image dataset with annotations on the appendix. After evaluation of all cases, the system displayed the diagnostic accuracy and average review time, and the trainee was asked to reassess the failed cases. The pilot system was deployed successfully in a hands-on workshop course. We developed an online radiology case review system that allows interactive navigation of volumetric image datasets using advanced visualization techniques

Development of an online radiology case review system featuring interactive navigation of volumetric image datasets using advanced visualization techniques

Energy Technology Data Exchange (ETDEWEB)

Yang, Hyun Kyung; Kim, Boh Kyoung; Jung, Ju Hyun; Kang, Heung Sik; Lee, Kyoung Ho [Dept. of Radiology, Seoul National University Bundang Hospital, Seongnam (Korea, Republic of); Woo, Hyun Soo [Dept. of Radiology, SMG-SNU Boramae Medical Center, Seoul (Korea, Republic of); Jo, Jae Min [Dept. of Computer Science and Engineering, Seoul National University, Seoul (Korea, Republic of); Lee, Min Hee [Dept. of Radiology, Soonchunhyang University Bucheon Hospital, Bucheon (Korea, Republic of)

2015-11-15

To develop an online radiology case review system that allows interactive navigation of volumetric image datasets using advanced visualization techniques. Our Institutional Review Board approved the use of the patient data and waived the need for informed consent. We determined the following system requirements: volumetric navigation, accessibility, scalability, undemanding case management, trainee encouragement, and simulation of a busy practice. The system comprised a case registry server, client case review program, and commercially available cloud-based image viewing system. In the pilot test, we used 30 cases of low-dose abdomen computed tomography for the diagnosis of acute appendicitis. In each case, a trainee was required to navigate through the images and submit answers to the case questions. The trainee was then given the correct answers and key images, as well as the image dataset with annotations on the appendix. After evaluation of all cases, the system displayed the diagnostic accuracy and average review time, and the trainee was asked to reassess the failed cases. The pilot system was deployed successfully in a hands-on workshop course. We developed an online radiology case review system that allows interactive navigation of volumetric image datasets using advanced visualization techniques.

Experimental Study on Effect of Operating Conditions on Thermoelectric Power Generation

DEFF Research Database (Denmark)

Mahmoudi Nezhad, Sajjad; Rezaniakolaei, Alireza; Rosendahl, Lasse Aistrup

2017-01-01

Effect of boundary conditions of thermal reservoirs on power generation of thermoelectric modules (TEMs) is examined experimentally. To realize the characteristics of the power generation by the TEMs, the system performance is studied over various volumetric flow rates and flow temperatures...

Effect of cup inclination on predicted contact stress-induced volumetric wear in total hip replacement.

Science.gov (United States)

Rijavec, B; Košak, R; Daniel, M; Kralj-Iglič, V; Dolinar, D

2015-01-01

In order to increase the lifetime of the total hip endoprosthesis, it is necessary to understand mechanisms leading to its failure. In this work, we address volumetric wear of the artificial cup, in particular the effect of its inclination with respect to the vertical. Volumetric wear was calculated by using mathematical models for resultant hip force, contact stress and penetration of the prosthesis head into the cup. Relevance of the dependence of volumetric wear on inclination of the cup (its abduction angle ϑA) was assessed by the results of 95 hips with implanted endoprosthesis. Geometrical parameters obtained from standard antero-posterior radiographs were taken as input data. Volumetric wear decreases with increasing cup abduction angle ϑA. The correlation within the population of 95 hips was statistically significant (P = 0.006). Large cup abduction angle minimises predicted volumetric wear but may increase the risk for dislocation of the artificial head from the cup in the one-legged stance. Cup abduction angle and direction of the resultant hip force may compensate each other to achieve optimal position of the cup with respect to wear and dislocation in the one-legged stance for a particular patient.

Structural brain alterations of Down's syndrome in early childhood evaluation by DTI and volumetric analyses

International Nuclear Information System (INIS)

Gunbey, Hediye Pinar; Bilgici, Meltem Ceyhan; Aslan, Kerim; Incesu, Lutfi; Has, Arzu Ceylan; Ogur, Methiye Gonul; Alhan, Aslihan

2017-01-01

To provide an initial assessment of white matter (WM) integrity with diffusion tensor imaging (DTI) and the accompanying volumetric changes in WM and grey matter (GM) through volumetric analyses of young children with Down's syndrome (DS). Ten children with DS and eight healthy control subjects were included in the study. Tract-based spatial statistics (TBSS) were used in the DTI study for whole-brain voxelwise analysis of fractional anisotropy (FA) and mean diffusivity (MD) of WM. Volumetric analyses were performed with an automated segmentation method to obtain regional measurements of cortical volumes. Children with DS showed significantly reduced FA in association tracts of the fronto-temporo-occipital regions as well as the corpus callosum (CC) and anterior limb of the internal capsule (p < 0.05). Volumetric reductions included total cortical GM, cerebellar GM and WM volume, basal ganglia, thalamus, brainstem and CC in DS compared with controls (p < 0.05). These preliminary results suggest that DTI and volumetric analyses may reflect the earliest complementary changes of the neurodevelopmental delay in children with DS and can serve as surrogate biomarkers of the specific elements of WM and GM integrity for cognitive development. (orig.)

Experimental determination of third-order elastic constants of diamond.

Science.gov (United States)

Lang, J M; Gupta, Y M

2011-03-25

To determine the nonlinear elastic response of diamond, single crystals were shock compressed along the [100], [110], and [111] orientations to 120 GPa peak elastic stresses. Particle velocity histories and elastic wave velocities were measured by using laser interferometry. The measured elastic wave profiles were used, in combination with published acoustic measurements, to determine the complete set of third-order elastic constants. These constants represent the first experimental determination, and several differ significantly from those calculated by using theoretical models.

Probabilistic atlas-guided eigen-organ method for simultaneous bounding box estimation of multiple organs in volumetric CT images

International Nuclear Information System (INIS)

Yao, Cong; Wada, Takashige; Shimizu, Akinobu; Kobatake, Hidefumi; Nawano, Shigeru

2006-01-01

We propose an approach for the simultaneous bounding box estimation of multiple organs in volumetric CT images. Local eigen-organ spaces are constructed for different types of training organs, and a global eigen-space, which describes the spatial relationships between the organs, is also constructed. Each volume of interest in the abdominal CT image is projected into the local eigen-organ spaces, and several candidate locations are determined. The final selection of the organ locations is made by projecting the set of candidate locations into the global eigen-space. A probabilistic atlas of organs is used to eliminate locations with low probability and to guide the selection of candidate locations. Evaluation by the leave-one-out method using 10 volumetric abdominal CT images showed that the proposed method provided an average accuracy of 80.38% for 11 different organ types. (author)

Combination volumetric and gravimetric sorption instrument for high accuracy measurements of methane adsorption

Science.gov (United States)

Burress, Jacob; Bethea, Donald; Troub, Brandon

2017-05-01

The accurate measurement of adsorbed gas up to high pressures (˜100 bars) is critical for the development of new materials for adsorbed gas storage. The typical Sievert-type volumetric method introduces accumulating errors that can become large at maximum pressures. Alternatively, gravimetric methods employing microbalances require careful buoyancy corrections. In this paper, we present a combination gravimetric and volumetric system for methane sorption measurements on samples between ˜0.5 and 1 g. The gravimetric method described requires no buoyancy corrections. The tandem use of the gravimetric method allows for a check on the highest uncertainty volumetric measurements. The sources and proper calculation of uncertainties are discussed. Results from methane measurements on activated carbon MSC-30 and metal-organic framework HKUST-1 are compared across methods and within the literature.

Computational simulation of turbulent natural convection in a volumetrically heated square cavity

International Nuclear Information System (INIS)

Vieira, Camila Braga; Su, Jian; Niceno, Bojan

2012-01-01

This work aims to analyze the turbulent natural convection in a volumetrically heated fluid with similar characteristics of an oxide layer of a molten core in the lower head of the pressure vessel. The simulations were carried out in a square cavity with isothermal walls, for Rayleigh numbers (Ra) ranging from 10 9 to 10 11 . Different turbulence models based on Reynolds Averaged Navier-Stokes equations were studied, such as the standard k - ε, low-Reynolds-k - ε, and Shear Stress Transport (SST), using the open-source Computational Fluid Dynamics (CFD) code - Open FOAM (Open Field Operation and Manipulation). The results of the three turbulence models were compared versus the results of experimental correlations and other authors’ simulations, and the conclusion was that the most promising model proves to be the SST, due to its accuracy and robustness. (author)

Volumetrics relate to the development of depression after traumatic brain injury.

Science.gov (United States)

Maller, Jerome J; Thomson, Richard H S; Pannek, Kerstin; Bailey, Neil; Lewis, Philip M; Fitzgerald, Paul B

2014-09-01

Previous research suggests that many people who sustain a traumatic brain injury (TBI), even of the mild form, will develop major depression (MD). We previously reported white matter integrity differences between those who did and did not develop MD after mild TBI. In this current paper, we aimed to investigate whether there were also volumetric differences between these groups, as suggested by previous volumetric studies in mild TBI populations. A sample of TBI-with-MD subjects (N=14), TBI-without-MD subjects (N=12), MD-without-TBI (N=26) and control subjects (no TBI or MD, N=23), received structural MRI brain scans. T1-weighted data were analysed using the Freesurfer software package which produces automated volumetric results. The findings of this study indicate that (1) TBI patients who develop MD have reduced volume in temporal, parietal and lingual regions compared to TBI patients who do not develop MD, and (2) MD patients with a history of TBI have decreased volume in the temporal region compared to those who had MD but without a history of TBI. We also found that more severe MD in those with TBI-with-MD significantly correlated with reduced volume in anterior cingulate, temporal lobe and insula. These findings suggest that volumetric reduction to specific regions, including parietal, temporal and occipital lobes, after a mild TBI may underlie the susceptibility of these patients developing major depression, in addition to altered white matter integrity. Copyright © 2014 Elsevier B.V. All rights reserved.

A feasibility study of digital tomosynthesis for volumetric dental imaging

International Nuclear Information System (INIS)

Cho, M K; Kim, H K; Youn, H; Kim, S S

2012-01-01

We present a volumetric dental tomography method that compensates for insufficient projection views obtained from limited-angle scans. The reconstruction algorithm is based on the backprojection filtering method which employs apodizing filters that reduce out-of-plane blur artifacts and suppress high-frequency noise. In order to accompolish this volumetric imaging two volume-reconstructed datasets are synthesized. These individual datasets provide two different limited-angle scans performed at orthogonal angles. The obtained reconstructed images, using less than 15% of the number of projection views needed for a full skull phantom scan, demonstrate the potential use of the proposed method in dental imaging applications. This method enables a much smaller radiation dose for the patient compared to conventional dental tomography.

MR volumetric analysis of the course of nephroblastomatosis under chemotherapy in childhood

International Nuclear Information System (INIS)

Guenther, Patrick; Waag, Karl Ludwig; Troeger, Jochen; Schenk, Jens-Peter; Graf, Norbert

2004-01-01

Nephroblastomatosis is a paediatric renal disease that may undergo malignant transformation. When neoadjuvant chemotherapy is indicated for nephroblastomatosis or bilateral Wilms' tumours, exact volumetric analysis using high-speed data processing and visualization may aid in determining tumour response. Using 3D-volume-rendering software, the 0.5-T MRI data of a 2-year-old girl with bilateral nephroblastomatosis was analysed. Exact volume determination of foci of nephroblastomatosis was performed by automatic and manual segmentation, and the relation to normal renal parenchyma was determined over a 12-month period. At the first visit, 80% (460/547 ml) of the extremely enlarged right kidney was due to nephroblastomatosis. Total tumour volume within the right kidney decreased to 74 ml under chemotherapy. Volume analysis of the two emerging right-sided masses after treatment correctly suggested Wilms' tumour. Three-dimensional rendering of the growing masses aided the surgeon in nephron-sparing surgery during tumour resection. (orig.)

MR volumetric analysis of the course of nephroblastomatosis under chemotherapy in childhood

Energy Technology Data Exchange (ETDEWEB)

Guenther, Patrick; Waag, Karl Ludwig [Department of Paediatric Surgery, University of Heidelberg, Im Neuenheimer Feld 110, 69120 Heidelberg (Germany); Troeger, Jochen; Schenk, Jens-Peter [Department of Paediatric Radiology, University of Heidelberg (Germany); Graf, Norbert [Department of Paediatric Oncology, Children' s Hospital, University of Homburg/Saar (Germany)

2004-08-01

Nephroblastomatosis is a paediatric renal disease that may undergo malignant transformation. When neoadjuvant chemotherapy is indicated for nephroblastomatosis or bilateral Wilms' tumours, exact volumetric analysis using high-speed data processing and visualization may aid in determining tumour response. Using 3D-volume-rendering software, the 0.5-T MRI data of a 2-year-old girl with bilateral nephroblastomatosis was analysed. Exact volume determination of foci of nephroblastomatosis was performed by automatic and manual segmentation, and the relation to normal renal parenchyma was determined over a 12-month period. At the first visit, 80% (460/547 ml) of the extremely enlarged right kidney was due to nephroblastomatosis. Total tumour volume within the right kidney decreased to 74 ml under chemotherapy. Volume analysis of the two emerging right-sided masses after treatment correctly suggested Wilms' tumour. Three-dimensional rendering of the growing masses aided the surgeon in nephron-sparing surgery during tumour resection. (orig.)

MR volumetric analysis of the course of nephroblastomatosis under chemotherapy in childhood.

Science.gov (United States)

Günther, Patrick; Tröger, Jochen; Graf, Norbert; Waag, Karl Ludwig; Schenk, Jens-Peter

2004-08-01

Nephroblastomatosis is a paediatric renal disease that may undergo malignant transformation. When neoadjuvant chemotherapy is indicated for nephroblastomatosis or bilateral Wilms' tumours, exact volumetric analysis using high-speed data processing and visualization may aid in determining tumour response. Using 3D-volume-rendering software, the 0.5-T MRI data of a 2-year-old girl with bilateral nephroblastomatosis was analysed. Exact volume determination of foci of nephroblastomatosis was performed by automatic and manual segmentation, and the relation to normal renal parenchyma was determined over a 12-month period. At the first visit, 80% (460/547 ml) of the extremely enlarged right kidney was due to nephroblastomatosis. Total tumour volume within the right kidney decreased to 74 ml under chemotherapy. Volume analysis of the two emerging right-sided masses after treatment correctly suggested Wilms' tumour. Three-dimensional rendering of the growing masses aided the surgeon in nephron-sparing surgery during tumour resection.

Crumpled Nitrogen-Doped Graphene for Supercapacitors with High Gravimetric and Volumetric Performances.

Science.gov (United States)

Wang, Jie; Ding, Bing; Xu, Yunling; Shen, Laifa; Dou, Hui; Zhang, Xiaogang

2015-10-14

Graphene is considered a promising electrochemical capacitors electrode material due to its high surface area and high electrical conductivity. However, restacking interactions between graphene nanosheets significantly decrease the ion-accessible surface area and impede electronic and ionic transfer. This would, in turn, severely hinder the realization of high energy density. Herein, we report a strategy for preparation of few-layer graphene material with abundant crumples and high-level nitrogen doping. The two-dimensional graphene nanosheets (CNG) feature high ion-available surface area, excellent electronic and ion transfer properties, and high packing density, permitting the CNG electrode to exhibit excellent electrochemical performance. In ionic liquid electrolyte, the CNG electrode exhibits gravimetric and volumetric capacitances of 128 F g(-1) and 98 F cm(-3), respectively, achieving gravimetric and volumetric energy densities of 56 Wh kg(-1) and 43 Wh L(-1). The preparation strategy described here provides a new approach for developing a graphene-based supercapacitor with high gravimetric and volumetric energy densities.

Energy based methods for determining elastic plastic fracture

International Nuclear Information System (INIS)

Witt, F.J.

1979-01-01

Several methods are currently in use or under study for calculating various conditions of fracturing for varying degrees of plasticity. Among these are innovations on the J-integral concept, crack opening displacement or angle, the two parameter concept and the equivalent energy method. Methods involving crack arrest and ductile tearing also fall in this category. Each of these methods have many salient points and some efforts are underway to establish the underlying relationship between them. In this paper, the current research directions of J-integral and equivalent energy methodologies are reviewed with a broader discussion presented for the equivalent energy methodology. The fundamental basis of equivalent energy methodology rests with the volumetric energy ratio. For fractures governed by linear elastic fracture mechanics, the volumetric energy ratio is independent of flaw size and geometry and depends only on the scale factor between model and prototype and temperature. The behavioral aspects of the volumetric energy ratios have been investigated throughout the temperature range from brittle fracture to fully ductile fracture. For five different specimen and structural configurations it has been shown experimentally that the volumetric energy ratio retains its basic properties. That is, the volumetric energy ratio while changing in actual value, maintains its independence of geometry and flaw size while retaining a unique dependence on scale factor and temperature. This property interpreted in terms of fracture mechanics leads to the equivalent energy method. (orig.)

Volumetric Analysis of Cerebral Peduncles and Cerebellar Hemispheres for Predicting Hemiparesis After Hemispherectomy.

Science.gov (United States)

Mullin, Jeffrey P; Soni, Pranay; Lee, Sungho; Jehi, Lara; Naduvil Valappi, Ahsan Moosa; Bingaman, William; Gonzalez-Martinez, Jorge

2016-09-01

In some cases of refractory epilepsy, hemispherectomy is the final invasive treatment option. However, predictors of postoperative hemiparesis in these patients have not been widely studied. To investigate how the volumetric analysis of cerebral peduncles and cerebellar hemispheres in patients who have undergone hemispherectomy may determine prognostic implications for postoperative hemiparesis. Twenty-two patients who underwent hemispherectomy at our institution were retrospectively included. Using iPlan/BrainLAB (BrainLAB, Feldkirchen, Germany) imaging software and a semiautomatic voxel-based segmentation method, we calculated the preoperative cerebral peduncle and cerebellar hemisphere volumes. Cerebral peduncle and cerebellar hemisphere ratios were compared between patients with worsened or unchanged/better hemiparesis postoperatively. The ratios of ipsilateral/contralateral cerebral peduncles (0.570 vs 0.828; P = .02) and contralateral/ipsilateral cerebellar hemispheres (0.885 vs 1.031; P = .009) were significantly lower in patients who had unchanged/improved hemiparesis postoperatively compared with patients who had worsened hemiparesis. Relative risk of worsening hemiparesis was significantly higher in patients with a cerebral peduncle ratio hemiparesis using only standard volumetric magnetic resonance imaging. This information could be used in preoperative discussions with patients and families to help better understand that chance of retaining baseline motor function. CST, corticospinal tractfMRI, functional magnetic resonance imagingTMS, transcranial magnetic stimulation.

COMPARISON OF VOLUMETRIC REGISTRATION ALGORITHMS FOR TENSOR-BASED MORPHOMETRY.

Science.gov (United States)

Villalon, Julio; Joshi, Anand A; Toga, Arthur W; Thompson, Paul M

2011-01-01

Nonlinear registration of brain MRI scans is often used to quantify morphological differences associated with disease or genetic factors. Recently, surface-guided fully 3D volumetric registrations have been developed that combine intensity-guided volume registrations with cortical surface constraints. In this paper, we compare one such algorithm to two popular high-dimensional volumetric registration methods: large-deformation viscous fluid registration, formulated in a Riemannian framework, and the diffeomorphic "Demons" algorithm. We performed an objective morphometric comparison, by using a large MRI dataset from 340 young adult twin subjects to examine 3D patterns of correlations in anatomical volumes. Surface-constrained volume registration gave greater effect sizes for detecting morphometric associations near the cortex, while the other two approaches gave greater effects sizes subcortically. These findings suggest novel ways to combine the advantages of multiple methods in the future.

Two-dimensional random arrays for real time volumetric imaging

DEFF Research Database (Denmark)

Davidsen, Richard E.; Jensen, Jørgen Arendt; Smith, Stephen W.

1994-01-01

real time volumetric imaging system, which employs a wide transmit beam and receive mode parallel processing to increase image frame rate. Depth-of-field comparisons were made from simulated on-axis and off-axis beamplots at ranges from 30 to 160 mm for both coaxial and offset transmit and receive......Two-dimensional arrays are necessary for a variety of ultrasonic imaging techniques, including elevation focusing, 2-D phase aberration correction, and real time volumetric imaging. In order to reduce system cost and complexity, sparse 2-D arrays have been considered with element geometries...... selected ad hoc, by algorithm, or by random process. Two random sparse array geometries and a sparse array with a Mills cross receive pattern were simulated and compared to a fully sampled aperture with the same overall dimensions. The sparse arrays were designed to the constraints of the Duke University...

Experimental determination of differential cross-sections of muonic neutrinos and muonic antineutrinos interactions

International Nuclear Information System (INIS)

Lutz, Anne-Marie.

1975-05-01

The experimental determination of muonic neutrinos and muonic antineutrinos differential cross-sections by the analysis of pictures taken in the CERN Gargamelle heavy liquid bubble chamber is presented. The methods used to solve experimental difficulties (muon identification, hadronic energy determination) and the errors on the experimental distributions are explained in detail. Then, the structure functions in charge changing interactions of neutrinos and antineutrinos are analyzed and interpreted in terms of parton distribution inside the nucleon [fr

Volumetric localization of epileptic activities in tuberous sclerosis using synthetic aperture magnetometry

Energy Technology Data Exchange (ETDEWEB)

Xiao, Zheng [Hospital for Sick Children, Research Institute, Toronto (Canada); Hospital for Sick Children, Department of Diagnostic Imaging, Toronto (Canada); Xiang, Jing [Hospital for Sick Children, Research Institute, Toronto (Canada); Hospital for Sick Children, Department of Diagnostic Imaging, Toronto (Canada); Holowka, Stephanie; Chuang, Sylvester [Hospital for Sick Children, Department of Diagnostic Imaging, Toronto (Canada); Hunjan, Amrita; Sharma, Rohit; Otsubo, Hiroshi [Hospital for Sick Children, Division of Neurology, Toronto (Canada)

2006-01-01

Magnetoencephalography (MEG) is a novel noninvasive technique for localizing epileptic zones. Tuberous sclerosis complex (TSC) is often associated with medically refractory epilepsy with multiple epileptic zones. Surgical treatment of TSC requires accurate localization of epileptogenic tubers. The objective of this study was to introduce a new MEG technique, synthetic aperture magnetometry (SAM), to volumetrically localize irritable zones and clarify the correlations between SAM, dipole modeling and anatomical tubers. Eight pediatric patients with TSC confirmed by clinical and neuroimaging findings were retrospectively studied. MEG data were recorded using a whole-cortex CTF OMEGA system. Sleep deprivation was employed to provoke epileptiform activity. Irritable zones were localized using both dipole modeling and SAM. MRI detected 42 tubers in the eight patients. Dipole modeling localized 28 irritable zones, and 19 out of the 28 zones were near tubers (19/42, 45%). SAM found 51 irritable zones, and 31 out of the 51 zones were near tubers (31/42, 74%). Among the 51 irritable zones determined by SAM, thirty-five zones were in 1-35 Hz, nine zones were in 35-60 Hz, and seven zones were in 60-120 Hz. The new method, SAM, yielded very plausible equivalent sources for patients who showed anatomical tubers on MRI. Compared to conventional dipole modeling, SAM appeared to offer increased detection of irritable zones and beneficial volumetric and frequency descriptions. (orig.)

Volumetric humidity timely variation, at different depths, in soils of a toposequence of the Reconcavo Baiano - Brazil

International Nuclear Information System (INIS)

Ribeiro, Antonio Carlos; Costa, Liovando Marciano da; Paiva, Arlicelio de Queiroz; Souza, Luciano da Silva; Santana, Marlete Bastos

1997-01-01

Aiming the time basis volumetric humidity evaluation, at different depths, the present work has been developed in a Reconcavo Baiano toposequence consisting of three different soils, in accordance with the distances from the toposequence begin. A neutron probe has been used for determination of the soil water contents. The relative counting of the neutron probe has been converted to gravimetric humidity by using regression equation for each type of soil

Densely-packed graphene/conducting polymer nanoparticle papers for high-volumetric-performance flexible all-solid-state supercapacitors

Science.gov (United States)

Yang, Chao; Zhang, Liling; Hu, Nantao; Yang, Zhi; Wei, Hao; Xu, Zhichuan J.; Wang, Yanyan; Zhang, Yafei

2016-08-01

Graphene-based all-solid-state supercapacitors (ASSSCs) are one of the most ideal candidates for high-performance flexible power sources. The achievement of high volumetric energy density is highly desired for practical application of this type of ASSSCs. Here, we present a facile method to boost volumetric performances of graphene-based flexible ASSSCs through incorporation of ultrafine polyaniline-poly(4-styrenesulfonate) (PANI-PSS) nanoparticles in reduced graphene oxide (rGO) papers. A compact structure is obtained via intimate contact and π-π interaction between PANI-PSS nanoparticles and rGO sheets. The hybrid paper electrode with the film thickness of 13.5 μm, shows an extremely high volumetric specific capacitance of 272 F/cm3 (0.37 A/cm3 in a three-electrode cell). The assembled ASSSCs show a large volumetric specific capacitance of 217 F/cm3 (0.37 A/cm3 in a two-electrode cell), high volumetric energy and power density, excellent capacitance stability, small leakage current as well as low self-discharge characteristics, revealing the usefulness of this robust hybrid paper for high-performance flexible energy storage devices.

Experimental Determination of Refractive Index of Gas Hydrates

DEFF Research Database (Denmark)

Bylov, Martin; Rasmussen, Peter

1997-01-01

. For methane hydrate (structure I) the refractive index was found to be 1.346 and for natural gas hydrate (structure II) it was found to be 1.350. The measurements further suggest that the gas hydrate growth rate increases if the water has formed hydrates before. The induction time, on the other hand, seems......The refractive indexes of methane hydrate and natural gas hydrate have been experimentally determined. The refractive indexes were determined in an indirect manner making use of the fact that two non-absorbing materials will have the same refractive index if they cannot be distinguished visually...

NDE Technology Development Program for Non-Visual Volumetric Inspection Technology; Sensor Effectiveness Testing Report

Energy Technology Data Exchange (ETDEWEB)

Moran, Traci L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Larche, Michael R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Denslow, Kayte M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Glass, Samuel W. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2017-08-31

The Pacific Northwest National Laboratory (PNNL) located in Richland, Washington, hosted and administered Sensor Effectiveness Testing that allowed four different participants to demonstrate the NDE volumetric inspection technologies that were previously demonstrated during the Technology Screening session. This document provides a Sensor Effectiveness Testing report for the final part of Phase I of a three-phase NDE Technology Development Program designed to identify and mature a system or set of non-visual volumetric NDE technologies for Hanford DST primary liner bottom inspection. Phase I of the program will baseline the performance of current or emerging non-visual volumetric NDE technologies for their ability to detect and characterize primary liner bottom flaws, and identify candidate technologies for adaptation and maturation for Phase II of the program.

Combined surface and volumetric occlusion shading

KAUST Repository

Schott, Matthias O.; Martin, Tobias; Grosset, A. V Pascal; Brownlee, Carson; Hollt, Thomas; Brown, Benjamin P.; Smith, Sean T.; Hansen, Charles D.

2012-01-01

In this paper, a method for interactive direct volume rendering is proposed that computes ambient occlusion effects for visualizations that combine both volumetric and geometric primitives, specifically tube shaped geometric objects representing streamlines, magnetic field lines or DTI fiber tracts. The proposed algorithm extends the recently proposed Directional Occlusion Shading model to allow the rendering of those geometric shapes in combination with a context providing 3D volume, considering mutual occlusion between structures represented by a volume or geometry. © 2012 IEEE.

Combined surface and volumetric occlusion shading

KAUST Repository

Schott, Matthias O.

2012-02-01

In this paper, a method for interactive direct volume rendering is proposed that computes ambient occlusion effects for visualizations that combine both volumetric and geometric primitives, specifically tube shaped geometric objects representing streamlines, magnetic field lines or DTI fiber tracts. The proposed algorithm extends the recently proposed Directional Occlusion Shading model to allow the rendering of those geometric shapes in combination with a context providing 3D volume, considering mutual occlusion between structures represented by a volume or geometry. © 2012 IEEE.

Analytical solution for stress, strain and plastic instability of pressurized pipes with volumetric flaws

International Nuclear Information System (INIS)

Cunha, Sérgio B.; Netto, Theodoro A.

2012-01-01

The mechanical behavior of internally pressurized pipes with volumetric flaws is analyzed. The two possible modes of circumferentially straining the pipe wall are identified and associated to hypothesized geometries. The radial deformation that takes place by bending the pipe wall is studied by means of axisymmetric flaws and the membrane strain developed by unequal hoop deformation is analyzed with the help of narrow axial flaws. Linear elastic shell solutions for stress and strain are developed, the plastic behavior is studied and the maximum hoop stress at the flaw is related to the undamaged pipe hoop stress by means of stress concentration factors. The stress concentration factors are employed to obtain equations predicting the pressure at which the pipe fails by plastic instability for both types of flaw. These analytical solutions are validated by comparison with burst tests on 3″ diameter pipes and finite element simulations. Forty-one burst tests were carried out and two materials with very dissimilar plastic behavior, carbon steel and austenitic stainless steel, were used in the experiments. Both the analytical and the numerical predictions showed good correlation with the experimentally observed burst pressures. - Highlights: ► An analytical model for the burst of a pipe with a volumetric flaw is developed. ► Deformation, strain and stress are modeled in the elastic and plastic domains. ► The model is comprehensively validated by experiments and numerical simulations. ► The burst pressure model’s accuracy is equivalent to finite element simulations.

Volumetric Medical Image Coding: An Object-based, Lossy-to-lossless and Fully Scalable Approach

Science.gov (United States)

Danyali, Habibiollah; Mertins, Alfred

2011-01-01

In this article, an object-based, highly scalable, lossy-to-lossless 3D wavelet coding approach for volumetric medical image data (e.g., magnetic resonance (MR) and computed tomography (CT)) is proposed. The new method, called 3DOBHS-SPIHT, is based on the well-known set partitioning in the hierarchical trees (SPIHT) algorithm and supports both quality and resolution scalability. The 3D input data is grouped into groups of slices (GOS) and each GOS is encoded and decoded as a separate unit. The symmetric tree definition of the original 3DSPIHT is improved by introducing a new asymmetric tree structure. While preserving the compression efficiency, the new tree structure allows for a small size of each GOS, which not only reduces memory consumption during the encoding and decoding processes, but also facilitates more efficient random access to certain segments of slices. To achieve more compression efficiency, the algorithm only encodes the main object of interest in each 3D data set, which can have any arbitrary shape, and ignores the unnecessary background. The experimental results on some MR data sets show the good performance of the 3DOBHS-SPIHT algorithm for multi-resolution lossy-to-lossless coding. The compression efficiency, full scalability, and object-based features of the proposed approach, beside its lossy-to-lossless coding support, make it a very attractive candidate for volumetric medical image information archiving and transmission applications. PMID:22606653

Mechanical model of human eye compliance for volumetric occlusion break surge measurements.

Science.gov (United States)

Dyk, David W; Miller, Kevin M

2018-02-01

To develop a mechanical model of human eye compliance for volumetric studies. Alcon Research, Ltd., Lake Forest, California, USA. Experimental study. Enucleated human eyes underwent pressurization and depressurization cycles with peak intraocular pressures (IOPs) of 60 to 100 mm Hg; anterior chamber pressure and volume changes were measured. Average net volume change curves were calculated as a function of IOP for each eye. Overall mean volumes were computed from each eye's average results at pressure points extrapolated over the range of 5 to 90 mm Hg. A 2-term exponential function was fit to these results. A fluid chamber with a displaceable piston was created as a mechanical model of this equation. A laser confocal displacement meter was used to measure piston displacement. A test bed incorporated the mechanical model with a mounted phacoemulsification probe and allowed for simulated occlusion breaks. Surge volume was calculated from piston displacement. An exponential function, V = C 1 × exp(C 2 × IOP) + C 3  × exp(C 4  × IOP) - V 0 , where V, the volume, was fit to the final depressurization curve obtained from 15 enucleated human eyes. The C 1 through C 4 values were -0.07141, -0.23055, -0.14972, and -0.02006, respectively. The equation was modeled using a piston system with 3 parallel springs that engaged serially. The mechanical model mimicked depressurization curves observed in human cadaver eyes. The resulting mechanical compliance model measured ocular volumetric changes and thus would be helpful in characterizing the postocclusion break surge response. Copyright © 2018 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

Experimental half-life determination of 176Lu

International Nuclear Information System (INIS)

Kossert, Karsten; Jörg, Gerhard; Gostomski, Christoph Lierse v.

2013-01-01

The half-life of the naturally occurring long-lived rare earth isotope 176 Lu was determined by a combination of highly sophisticated experimental procedures in order to further improve the reliability and the precision of literature data. The amount of lutetium in the samples was determined by inductively coupled plasma optical emission spectrometry (ICP-OES) using a NIST reference standard. The isotopic ratio N( 176 Lu)/N(Lu) in the samples was measured by means of inductively coupled plasma high resolution mass spectrometry (ICP-HRMS). The activity divided by the mass of Lu was determined by applying liquid scintillation (LS) counting. The LS counting efficiency of the beta/gamma emitter 176 Lu was determined with the CIEMAT/NIST efficiency tracing technique with low uncertainty. The influences of colour quenching and background effects are discussed in this paper. The half-life was found to be 3.640(35)×10 10 y. The result is in good agreement with other evaluations and the relative standard uncertainty of 0.95% is among the lowest of previously published data. - Highlights: • The half-life of 176 Lu was determined by ICP-OES, ICP-HRMS and LSC. • The LSC efficiency was determined with the CIEMAT/NIST method. • The half-life was found to be 3.640(35)×10 10 y

Three-Dimensional Dynamic Rupture in Brittle Solids and the Volumetric Strain Criterion

Science.gov (United States)

Uenishi, K.; Yamachi, H.

2017-12-01

As pointed out by Uenishi (2016 AGU Fall Meeting), source dynamics of ordinary earthquakes is often studied in the framework of 3D rupture in brittle solids but our knowledge of mechanics of actual 3D rupture is limited. Typically, criteria derived from 1D frictional observations of sliding materials or post-failure behavior of solids are applied in seismic simulations, and although mode-I cracks are frequently encountered in earthquake-induced ground failures, rupture in tension is in most cases ignored. Even when it is included in analyses, the classical maximum principal tensile stress rupture criterion is repeatedly used. Our recent basic experiments of dynamic rupture of spherical or cylindrical monolithic brittle solids by applying high-voltage electric discharge impulses or impact loads have indicated generation of surprisingly simple and often flat rupture surfaces in 3D specimens even without the initial existence of planes of weakness. However, at the same time, the snapshots taken by a high-speed digital video camera have shown rather complicated histories of rupture development in these 3D solid materials, which seem to be difficult to be explained by, for example, the maximum principal stress criterion. Instead, a (tensile) volumetric strain criterion where the volumetric strain (dilatation or the first invariant of the strain tensor) is a decisive parameter for rupture seems more effective in computationally reproducing the multi-directionally propagating waves and rupture. In this study, we try to show the connection between this volumetric strain criterion and other classical rupture criteria or physical parameters employed in continuum mechanics, and indicate that the criterion has, to some degree, physical meanings. First, we mathematically illustrate that the criterion is equivalent to a criterion based on the mean normal stress, a crucial parameter in plasticity. Then, we mention the relation between the volumetric strain criterion and the

GPU-based Scalable Volumetric Reconstruction for Multi-view Stereo

Energy Technology Data Exchange (ETDEWEB)

Kim, H; Duchaineau, M; Max, N

2011-09-21

We present a new scalable volumetric reconstruction algorithm for multi-view stereo using a graphics processing unit (GPU). It is an effectively parallelized GPU algorithm that simultaneously uses a large number of GPU threads, each of which performs voxel carving, in order to integrate depth maps with images from multiple views. Each depth map, triangulated from pair-wise semi-dense correspondences, represents a view-dependent surface of the scene. This algorithm also provides scalability for large-scale scene reconstruction in a high resolution voxel grid by utilizing streaming and parallel computation. The output is a photo-realistic 3D scene model in a volumetric or point-based representation. We demonstrate the effectiveness and the speed of our algorithm with a synthetic scene and real urban/outdoor scenes. Our method can also be integrated with existing multi-view stereo algorithms such as PMVS2 to fill holes or gaps in textureless regions.

CO2 Capacity Sorbent Analysis Using Volumetric Measurement Approach

Science.gov (United States)

Huang, Roger; Richardson, Tra-My Justine; Belancik, Grace; Jan, Darrell; Knox, Jim

2017-01-01

In support of air revitalization system sorbent selection for future space missions, Ames Research Center (ARC) has performed CO2 capacity tests on various solid sorbents to complement structural strength tests conducted at Marshall Space Flight Center (MSFC). The materials of interest are: Grace Davison Grade 544 13X, Honeywell UOP APG III, LiLSX VSA-10, BASF 13X, and Grace Davison Grade 522 5A. CO2 capacity was for all sorbent materials using a Micromeritics ASAP 2020 Physisorption Volumetric Analysis machine to produce 0C, 10C, 25C, 50C, and 75C isotherms. These data are to be used for modeling data and to provide a basis for continued sorbent research. The volumetric analysis method proved to be effective in generating consistent and repeatable data for the 13X sorbents, but the method needs to be refined to tailor to different sorbents.

Toward a Philosophy and Theory of Volumetric Nonthermal Processing.

Science.gov (United States)

Sastry, Sudhir K

2016-06-01

Nonthermal processes for food preservation have been under intensive investigation for about the past quarter century, with varying degrees of success. We focus this discussion on two volumetrically acting nonthermal processes, high pressure processing (HPP) and pulsed electric fields (PEF), with emphasis on scientific understanding of each, and the research questions that need to be addressed for each to be more successful in the future. We discuss the character or "philosophy" of food preservation, with a question about the nature of the kill step(s), and the sensing challenges that need to be addressed. For HPP, key questions and needs center around whether its nonthermal effectiveness can be increased by increased pressures or pulsing, the theoretical treatment of rates of reaction as influenced by pressure, the assumption of uniform pressure distribution, and the need for (and difficulties involved in) in-situ measurement. For PEF, the questions include the rationale for pulsing, difficulties involved in continuous flow treatment chambers, the difference between electroporation theory and experimental observations, and the difficulties involved in in-situ measurement and monitoring of electric field distribution. © 2016 Institute of Food Technologists®

Volumetric polymerization shrinkage of contemporary composite resins

OpenAIRE

Nagem Filho, Halim; Nagem, Haline Drumond; Francisconi, Paulo Afonso Silveira; Franco, Eduardo Batista; Mondelli, Rafael Francisco Lia; Coutinho, Kennedy Queiroz

2007-01-01

The polymerization shrinkage of composite resins may affect negatively the clinical outcome of the restoration. Extensive research has been carried out to develop new formulations of composite resins in order to provide good handling characteristics and some dimensional stability during polymerization. The purpose of this study was to analyze, in vitro, the magnitude of the volumetric polymerization shrinkage of 7 contemporary composite resins (Definite, Suprafill, SureFil, Filtek Z250, Fill ...

Tree tomato water requirements determined by neutron probe

International Nuclear Information System (INIS)

1994-01-01

The dynamics of water was studied at ''La Tola'', experimental teaching center of the Central University of Ecuador, in a sandy-loan, typic durustoll soil in which trees tomato were growing. All the components of the crop water balance were determined. Real evapotranspiration (ETR) was estimated through the mass balance method, using every 5-10 days a neutron probe to access the volumetric humidity of the soil. The real evapotranspiration was in direct relation with the growth of the crop, reaching its maximum value of 3,8 mm day-1, at vegetative stage. The soil layer supplying most of the water for the consumptive use of the crop was between 0-40 cm being the root activity also greater in that layer

Volumetric velocity measurements in restricted geometries using spiral sampling: a phantom study.

Science.gov (United States)

Nilsson, Anders; Revstedt, Johan; Heiberg, Einar; Ståhlberg, Freddy; Bloch, Karin Markenroth

2015-04-01

The aim of this study was to evaluate the accuracy of maximum velocity measurements using volumetric phase-contrast imaging with spiral readouts in a stenotic flow phantom. In a phantom model, maximum velocity, flow, pressure gradient, and streamline visualizations were evaluated using volumetric phase-contrast magnetic resonance imaging (MRI) with velocity encoding in one (extending on current clinical practice) and three directions (for characterization of the flow field) using spiral readouts. Results of maximum velocity and pressure drop were compared to computational fluid dynamics (CFD) simulations, as well as corresponding low-echo-time (TE) Cartesian data. Flow was compared to 2D through-plane phase contrast (PC) upstream from the restriction. Results obtained with 3D through-plane PC as well as 4D PC at shortest TE using a spiral readout showed excellent agreements with the maximum velocity values obtained with CFD (spiral sequences were respectively 14 and 13 % overestimated compared to CFD. Identification of the maximum velocity location, as well as the accurate velocity quantification can be obtained in stenotic regions using short-TE spiral volumetric PC imaging.

Nanofoaming to Boost the Electrochemical Performance of Ni@Ni(OH)2 Nanowires for Ultrahigh Volumetric Supercapacitors.

Science.gov (United States)

Xu, Shusheng; Li, Xiaolin; Yang, Zhi; Wang, Tao; Jiang, Wenkai; Yang, Chao; Wang, Shuai; Hu, Nantao; Wei, Hao; Zhang, Yafei

2016-10-10

Three-dimensional free-standing film electrodes have aroused great interest for energy storage devices. However, small volumetric capacity and low operating voltage limit their practical application for large energy storage applications. Herein, a facile and novel nanofoaming process was demonstrated to boost the volumetric electrochemical capacitance of the devices via activation of Ni nanowires to form ultrathin nanosheets and porous nanostructures. The as-designed free-standing Ni@Ni(OH) 2 film electrodes display a significantly enhanced volumetric capacity (462 C/cm 3 at 0.5 A/cm 3 ) and excellent cycle stability. Moreover, the as-developed hybrid supercapacitor employed Ni@Ni(OH) 2 film as positive electrode and graphene-carbon nanotube film as negative electrode exhibits a high volumetric capacitance of 95 F/cm 3 (at 0.25 A/cm 3 ) and excellent cycle performance (only 14% capacitance reduction for 4500 cycles). Furthermore, the volumetric energy density can reach 33.9 mWh/cm 3 , which is much higher than that of most thin film lithium batteries (1-10 mWh/cm 3 ). This work gives an insight for designing high-volume three-dimensional electrodes and paves a new way to construct binder-free film electrode for high-performance hybrid supercapacitor applications.

Benchmark calculations for evaluation methods of gas volumetric leakage rate

International Nuclear Information System (INIS)

Asano, R.; Aritomi, M.; Matsuzaki, M.

1998-01-01

A containment function of radioactive materials transport casks is essential for safe transportation to prevent the radioactive materials from being released into environment. Regulations such as IAEA standard determined the limit of radioactivity to be released. Since is not practical for the leakage tests to measure directly the radioactivity release from a package, as gas volumetric leakages rates are proposed in ANSI N14.5 and ISO standards. In our previous works, gas volumetric leakage rates for several kinds of gas from various leaks were measured and two evaluation methods, 'a simple evaluation method' and 'a strict evaluation method', were proposed based on the results. The simple evaluation method considers the friction loss of laminar flow with expansion effect. The strict evaluating method considers an exit loss in addition to the friction loss. In this study, four worked examples were completed for on assumed large spent fuel transport cask (Type B Package) with wet or dry capacity and at three transport conditions; normal transport with intact fuels or failed fuels, and an accident in transport. The standard leakage rates and criteria for two kinds of leak test were calculated for each example by each evaluation method. The following observations are made based upon the calculations and evaluations: the choked flow model of ANSI method greatly overestimates the criteria for tests ; the laminar flow models of both ANSI and ISO methods slightly overestimate the criteria for tests; the above two results are within the design margin for ordinary transport condition and all methods are useful for the evaluation; for severe condition such as failed fuel transportation, it should pay attention to apply a choked flow model of ANSI method. (authors)

Activated crystals of fluorite type as photochromic mediums for recording of volumetric holograms

International Nuclear Information System (INIS)

Arkhangel'skaya, V.A.; Ashcheulov, Yu.V.; Perfilov, V.N.; Rejterov, V.M.; Sukhanov, V.I.; Feofilov, P.P.

1975-01-01

The paper is a study of the mechanism of photochromism and of the photochromic and holographic properties of fluorides of alkaline earth metals with one and two rare-earth activators. It is shown that the angular selectivity of ''thick'' (d approximately 2-5 mm) crystals is 2-3 angular minutes and that the optimum energy exposures, corresponding to the maximum diffraction efficiency values, are 0.1-1.0 J/cm 2 for singly-activated crystals and 1.0-10 J/cm 2 for crystals with two activators. The diffraction efficiencies of holograms of both types of crystals is in the range of approximately 0.1-0.2%. The experimental data are compared with calculations made for photochromic crystals with pigmentation centres. It is suggested that the materials studied can serve as a basis for measuring volumetric holograms. (author)

Designing remote web-based mechanical-volumetric flow meter ...

African Journals Online (AJOL)

Today, in water and wastewater industry a lot of mechanical-volumetric flow meters are used for the navigation of the produced water and the data of these flow meters, due to use in a wide geographical range, is done physically and by in person presence. All this makes reading the data costly and, in some cases, due to ...

Volumetric measurements of pulmonary nodules at multi-row detector CT: in vivo reproducibility

International Nuclear Information System (INIS)

Wormanns, Dag; Marheine, Anke; Beyer, Florian; Heindel, Walter; Diederich, Stefan; Kohl, Gerhard; Klotz, Ernst

2004-01-01

The aim of this study was to assess the in vivo measurement precision of a software tool for volumetric analysis of pulmonary nodules from two consecutive low-dose multi-row detector CT scans. A total of 151 pulmonary nodules (diameter 2.2-20.5 mm, mean diameter 7.4±4.5 mm) in ten subjects with pulmonary metastases were examined with low-dose four-detector-row CT (120 kVp, 20 mAs (effective), collimation 4 x 1 mm, normalized pitch 1.75, slice thickness 1.25 mm, reconstruction increment 0.8 mm; Somatom VolumeZoom, Siemens). Two consecutive low-dose scans covering the whole lung were performed within 10 min. Nodule volume was determined for all pulmonary nodules visually detected in both scans using the volumetry tool included in the Siemens LungCare software. The 95% limits of agreement between nodule volume measurements on different scans were calculated using the Bland and Altman method for assessing measurement agreement. Intra- and interobserver agreement of volume measurement were determined using repetitive measurements of 50 randomly selected nodules at the same scan by the same and different observers. Taking into account all 151 nodules, 95% limits of agreement were -20.4 to 21.9% (standard error 1.5%); they were -19.3 to 20.4% (standard error 1.7%) for 105 nodules <10 mm. Limits of agreement were -3.9 to 5.7% for intraobserver and -5.5 to 6.6% for interobserver agreement. Precision of in vivo volumetric analysis of nodules with an automatic volumetry software tool was sufficiently high to allow for detection of clinically relevant growth in small pulmonary nodules. (orig.)

Clarification of the volumetric properties of the (tetrahydrofuran + water) systems [J. Chem. Thermodyn. 41 (2009) 1382–1386]: Author’s statement

International Nuclear Information System (INIS)

Belandria, Veronica; Pimentel-Rodas, Alfredo; Mohammadi, Amir H.; Galicia-Luna, Luis A.; Richon, Dominique

2013-01-01

Highlights: ► New experimental density data are reported for the (THF + water) systems. ► A vibrating tube densimeter has been used to perform the measurements. ► A discussion is made on the reliability of the generated data and other questions raised in the literature. - Abstract: Although reliable and consistent volumetric data can be derived from density measurements, the greatest experimental difficulty and largest measurement errors often occur in the very dilute regions of concentration. Such data are of great interest in separation processes where a high degree of purity is required. In this communication, the densities of the (tetrahydrofuran + water) systems have been carefully investigated in dilute regions. A vibrating tube densimeter has been used to perform the measurements. A discussion is made on the reliability of the generated experimental data and the questions raised in the literature.

Superficial Collagen Fibril Modulus and Pericellular Fixed Charge Density Modulate Chondrocyte Volumetric Behaviour in Early Osteoarthritis

Directory of Open Access Journals (Sweden)

Petri Tanska

2013-01-01

Full Text Available The aim of this study was to investigate if the experimentally detected altered chondrocyte volumetric behavior in early osteoarthritis can be explained by changes in the extracellular and pericellular matrix properties of cartilage. Based on our own experimental tests and the literature, the structural and mechanical parameters for normal and osteoarthritic cartilage were implemented into a multiscale fibril-reinforced poroelastic swelling model. Model simulations were compared with experimentally observed cell volume changes in mechanically loaded cartilage, obtained from anterior cruciate ligament transected rabbit knees. We found that the cell volume increased by 7% in the osteoarthritic cartilage model following mechanical loading of the tissue. In contrast, the cell volume decreased by 4% in normal cartilage model. These findings were consistent with the experimental results. Increased local transversal tissue strain due to the reduced collagen fibril stiffness accompanied with the reduced fixed charge density of the pericellular matrix could increase the cell volume up to 12%. These findings suggest that the increase in the cell volume in mechanically loaded osteoarthritic cartilage is primarily explained by the reduction in the pericellular fixed charge density, while the superficial collagen fibril stiffness is suggested to contribute secondarily to the cell volume behavior.

Area and volumetric density estimation in processed full-field digital mammograms for risk assessment of breast cancer.

Directory of Open Access Journals (Sweden)

Abbas Cheddad

Full Text Available INTRODUCTION: Mammographic density, the white radiolucent part of a mammogram, is a marker of breast cancer risk and mammographic sensitivity. There are several means of measuring mammographic density, among which are area-based and volumetric-based approaches. Current volumetric methods use only unprocessed, raw mammograms, which is a problematic restriction since such raw mammograms are normally not stored. We describe fully automated methods for measuring both area and volumetric mammographic density from processed images. METHODS: The data set used in this study comprises raw and processed images of the same view from 1462 women. We developed two algorithms for processed images, an automated area-based approach (CASAM-Area and a volumetric-based approach (CASAM-Vol. The latter method was based on training a random forest prediction model with image statistical features as predictors, against a volumetric measure, Volpara, for corresponding raw images. We contrast the three methods, CASAM-Area, CASAM-Vol and Volpara directly and in terms of association with breast cancer risk and a known genetic variant for mammographic density and breast cancer, rs10995190 in the gene ZNF365. Associations with breast cancer risk were evaluated using images from 47 breast cancer cases and 1011 control subjects. The genetic association analysis was based on 1011 control subjects. RESULTS: All three measures of mammographic density were associated with breast cancer risk and rs10995190 (p0.10 for risk, p>0.03 for rs10995190. CONCLUSIONS: Our results show that it is possible to obtain reliable automated measures of volumetric and area mammographic density from processed digital images. Area and volumetric measures of density on processed digital images performed similar in terms of risk and genetic association.

Structural brain alterations of Down's syndrome in early childhood evaluation by DTI and volumetric analyses

Energy Technology Data Exchange (ETDEWEB)

Gunbey, Hediye Pinar; Bilgici, Meltem Ceyhan; Aslan, Kerim; Incesu, Lutfi [Ondokuz Mayis University, Faculty of Medicine, Department of Radiology, Kurupelit, Samsun (Turkey); Has, Arzu Ceylan [Bilkent University, National Magnetic Resonance Research Center, Ankara (Turkey); Ogur, Methiye Gonul [Ondokuz Mayis University, Department of Genetics, Samsun (Turkey); Alhan, Aslihan [Ufuk University, Department of Statistics, Ankara (Turkey)

2017-07-15

To provide an initial assessment of white matter (WM) integrity with diffusion tensor imaging (DTI) and the accompanying volumetric changes in WM and grey matter (GM) through volumetric analyses of young children with Down's syndrome (DS). Ten children with DS and eight healthy control subjects were included in the study. Tract-based spatial statistics (TBSS) were used in the DTI study for whole-brain voxelwise analysis of fractional anisotropy (FA) and mean diffusivity (MD) of WM. Volumetric analyses were performed with an automated segmentation method to obtain regional measurements of cortical volumes. Children with DS showed significantly reduced FA in association tracts of the fronto-temporo-occipital regions as well as the corpus callosum (CC) and anterior limb of the internal capsule (p < 0.05). Volumetric reductions included total cortical GM, cerebellar GM and WM volume, basal ganglia, thalamus, brainstem and CC in DS compared with controls (p < 0.05). These preliminary results suggest that DTI and volumetric analyses may reflect the earliest complementary changes of the neurodevelopmental delay in children with DS and can serve as surrogate biomarkers of the specific elements of WM and GM integrity for cognitive development. (orig.)

Evaluation of Accordance of Magnetic Resonance Volumetric and Flow Measurements in Determining Ventricular Stroke Volume in Cardiac Patients

International Nuclear Information System (INIS)

Jeltsch, M.; Ranft, S.; Klass, O.; Aschoff, A.J.; Hoffmann, M.H.K.

2008-01-01

Background: Cardiovascular magnetic resonance imaging (CMR) has become an established noninvasive method for evaluating ventricular function utilizing three-dimensional volumetry. Postprocessing of volumetric measurements is still tedious and time consuming. Stroke volumes obtained by flow quantification across the aortic root or pulmonary trunk could be utilized to increase both speed of workflow and accuracy. Purpose: To assess accuracy of stroke volume quantification using MR volumetric imaging compared to flow quantification in patients with various cardiac diseases. Strategies for the augmentation of accuracy in clinical routine were deduced. Material and Methods: 78 patients with various cardiac diseases -excluding intra- or extracardiac shunts, regurgitant valvular defects, or heart rhythm disturbance -underwent cardiac function analysis with flow measurements across the aortic root and cine imaging of the left ventricle. Forty-six patients additionally underwent flow measurements in the pulmonary trunk and cine imaging of the right ventricle. Results: Left ventricular stroke volume (LVSV) and stroke volume of the aortic root (SVAo) correlated with r=0.97, and Bland-Altman analysis showed a mean difference of 0.11 ml and a standard error of estimation (SEE) of 4.31 ml. Ninety-two percent of the data were within the 95% limits of agreement. Right ventricular stroke volume (RVSV) and stroke volume of the pulmonary trunk (SVP) correlated with a factor of r=0.86, and mean difference in the Bland-Altman analysis was fixed at -2.62 ml (SEE 8.47 ml). For RVSV and SVP, we calculated r=0.82, and Bland-Altman analysis revealed a mean difference of 1.27 ml (SEE 9.89 ml). LVSV and RVSV correlated closely, with r=0.91 and a mean difference of 2.79 ml (SEE 7.17 ml). SVAo and SVP correlated with r=0.95 and a mean difference of 0.50 ml (SEE 5.56 ml). Conclusion: Flow quantification can be used as a guidance tool, providing accurate and reproducible stroke volumes of both

100KE/KW fuel storage basin surface volumetric factors

International Nuclear Information System (INIS)

Conn, K.R.

1996-01-01

This Supporting Document presents calculations of surface Volumetric factors for the 100KE and 100KW Fuel Storage Basins. These factors relate water level changes to basin loss or additions of water, or the equivalent water displacement volumes of objects added to or removed from the basin

Volumetric and superficial characterization of carbon activated

International Nuclear Information System (INIS)

Carrera G, L.M.; Garcia S, I.; Jimenez B, J.; Solache R, M.; Lopez M, B.; Bulbulian G, S.; Olguin G, M.T.

2000-01-01

The activated carbon is the resultant material of the calcination process of natural carbonated materials as coconut shells or olive little bones. It is an excellent adsorbent of diluted substances, so much in colloidal form, as in particles form. Those substances are attracted and retained by the carbon surface. In this work is make the volumetric and superficial characterization of activated carbon treated thermically (300 Centigrade) in function of the grain size average. (Author)

High volumetric power density, non-enzymatic, glucose fuel cells.

Science.gov (United States)

Oncescu, Vlad; Erickson, David

2013-01-01

The development of new implantable medical devices has been limited in the past by slow advances in lithium battery technology. Non-enzymatic glucose fuel cells are promising replacement candidates for lithium batteries because of good long-term stability and adequate power density. The devices developed to date however use an "oxygen depletion design" whereby the electrodes are stacked on top of each other leading to low volumetric power density and complicated fabrication protocols. Here we have developed a novel single-layer fuel cell with good performance (2 μW cm⁻²) and stability that can be integrated directly as a coating layer on large implantable devices, or stacked to obtain a high volumetric power density (over 16 μW cm⁻³). This represents the first demonstration of a low volume non-enzymatic fuel cell stack with high power density, greatly increasing the range of applications for non-enzymatic glucose fuel cells.

Effects of clustering structure on volumetric properties of amino acids in (DMSO + water) mixtures

International Nuclear Information System (INIS)

Huang Aimin; Liu Chunli; Ma Lin; Tong Zhangfa; Lin Ruisen

2012-01-01

Graphical abstract: Together with static light scattering measurement, volumetric properties of glycine, L-alanine and L-serine were determined and utilized to reveal the microscopic solvent structure of (DMSO + water) mixtures and its influence on the interaction between DMSO and amino acids from a clustering point of view. The results demonstrated that the interaction between amino acids and DMSO was greatly related to the clustering structure of the mixed solvent and that amino acids interacted with already established solvent clusters. Hydrophobic aggregating of DMSO lead to a decrease in the hydrophobic effect of DMSO and the hydrophobic–hydrophilic and hydrophobic–hydrophobic interaction with amino acids, which was reflected by the solvation of proteins. Highlights: ► Determine volumetric properties of three amino acids in aqueous DMSO in details. ► Static light scattering measurement for clustering structure of aqueous DMSO. ► Volumetric behaviour of amino acids depends on clustering structure of aqueous DMSO. ► Clustering structure of aqueous DMSO influences solvation of protein and cellulose. - Abstract: For a better understanding on the functions of DMSO in biological systems at a relatively lower concentration, apparent molar volumes of three typical amino acids, glycine, L-alanine and L-serine in (DMSO + water) mixtures were determined and the transfer volumes from water to the mixtures were evaluated. Together with static light scattering measurement, the results were utilised to reveal the microscopic solvent structure of (DMSO + water) mixtures and its influence on the interaction between DMSO and amino acids from a clustering point of view. The results demonstrate that the interaction between amino acids and DMSO is greatly related to the clustering structure of the mixed solvent and that amino acids interacted with already established solvent clusters. The linear dependence of transfer volume of amino acids on DMSO concentration up to 2

Zeolite-filled silicone rubber membranes. Experimental determination of concentration profiles

NARCIS (Netherlands)

te Hennepe, H.J.C.; Boswerger, W.B.F.; Bargeman, D.; Bargeman, D.; Mulder, M.H.V.; Smolders, C.A.; Smolders, C.A.

1994-01-01

Permeant concentrations in silicalite-filled silicone rubber membranes during pervaporation of propanol/water mixtures were measured using multi-layered membranes. Experimentally determined concentration profiles show that the propanol concentration in the silicalite-filled membrane increases with

Influence of Cobb Angle and ISIS2 Surface Topography Volumetric Asymmetry on Scoliosis Research Society-22 Outcome Scores in Scoliosis.

Science.gov (United States)

Brewer, Paul; Berryman, Fiona; Baker, De; Pynsent, Paul; Gardner, Adrian

2013-11-01

Retrospective sequential patient series. To establish the relationship between the magnitude of the deformity in scoliosis and patients' perception of their condition, as measured with Scoliosis Research Society-22 scores. A total of 93 untreated patients with adolescent idiopathic scoliosis were included retrospectively. The Cobb angle was measured from a plain radiograph, and volumetric asymmetry was measured by ISIS2 surface topography. The association between Scoliosis Research Society scores for function, pain, self-image, and mental health against Cobb angle and volumetric asymmetry was investigated using the Pearson correlation coefficient. Correlation of both Cobb angle and volumetric asymmetry with function and pain was weak (all self-image, was higher, although still moderate (-.37 for Cobb angle and -.44 for volumetric asymmetry). Both were statistically significant (Cobb angle, p = .0002; volumetric asymmetry; p = .00001). Cobb angle contributed 13.8% to the linear relationship with self-image, whereas volumetric asymmetry contributed 19.3%. For mental health, correlation was statistically significant with Cobb angle (p = .011) and volumetric asymmetry (p = .0005), but the correlation was low to moderate (-.26 and -.35, respectively). Cobb angle contributed 6.9% to the linear relationship with mental health, whereas volumetric asymmetry contributed 12.4%. Volumetric asymmetry correlates better with both mental health and self-image compared with Cobb angle, but the correlation was only moderate. This study suggests that a patient's own perception of self-image and mental health is multifactorial and not completely explained through present objective measurements of the size of the deformity. This helps to explain the difficulties in any objective analysis of a problem with multifactorial perception issues. Further study is required to investigate other physical aspects of the deformity that may have a role in how patients view themselves. Copyright �

Volumetric error modeling, identification and compensation based on screw theory for a large multi-axis propeller-measuring machine

Science.gov (United States)

Zhong, Xuemin; Liu, Hongqi; Mao, Xinyong; Li, Bin; He, Songping; Peng, Fangyu

2018-05-01

Large multi-axis propeller-measuring machines have two types of geometric error, position-independent geometric errors (PIGEs) and position-dependent geometric errors (PDGEs), which both have significant effects on the volumetric error of the measuring tool relative to the worktable. This paper focuses on modeling, identifying and compensating for the volumetric error of the measuring machine. A volumetric error model in the base coordinate system is established based on screw theory considering all the geometric errors. In order to fully identify all the geometric error parameters, a new method for systematic measurement and identification is proposed. All the PIGEs of adjacent axes and the six PDGEs of the linear axes are identified with a laser tracker using the proposed model. Finally, a volumetric error compensation strategy is presented and an inverse kinematic solution for compensation is proposed. The final measuring and compensation experiments have further verified the efficiency and effectiveness of the measuring and identification method, indicating that the method can be used in volumetric error compensation for large machine tools.

Characterizing volumetric deformation behavior of naturally occuring bituminous sand materials

CSIR Research Space (South Africa)

Anochie-Boateng, Joseph

2009-05-01

Full Text Available newly proposed hydrostatic compression test procedure. The test procedure applies field loading conditions of off-road construction and mining equipment to closely simulate the volumetric deformation and stiffness behaviour of oil sand materials. Based...

Continuous assessment of carotid intima-media thickness applied to estimate a volumetric compliance using B-mode ultrasound sequences

International Nuclear Information System (INIS)

Pascaner, A F; Craiem, D; Casciaro, M E; Graf, S; Danielo, R; Guevara, E

2015-01-01

Recent reports have shown that the carotid artery wall had significant movements not only in the radial but also in the longitudinal direction during the cardiac cycle. Accordingly, the idea that longitudinal elongations could be systematically neglected for compliance estimations became controversial. Assuming a dynamic change in vessel length, the standard measurement of cross-sectional compliance can be revised. In this work, we propose to estimate a volumetric compliance based on continuous measurements of carotid diameter and intima-media thickness (IMT) from B-mode ultrasound sequences. Assuming the principle of conservation of the mass of wall volume (compressibility equals zero), a temporal longitudinal elongation can be calculated to estimate a volumetric compliance. Moreover, elongations can also be estimated allowing small compressibility factors to model some wall leakage. The cross-sectional and the volumetric compliance were estimated in 45 healthy volunteers and 19 asymptomatic patients. The standard measurement underestimated the volumetric compliance by 25% for young volunteers (p < 0.01) and 17% for patients (p < 0.05). When compressibility factors different from zero were allowed, volunteers and patients reached values of 9% and 4%, respectively. We conclude that a simultaneous assessment of carotid diameter and IMT can be employed to estimate a volumetric compliance incorporating a longitudinal elongation. The cross-sectional compliance, that neglects the change in vessel length, underestimates the volumetric compliance. (paper)

Hippocampus, caudate nucleus and entorhinal cortex volumetric MRI measurements in discrimination between Alzheimer’s disease, mild cognitive impairment, and normal aging

Directory of Open Access Journals (Sweden)

Rasha Elshafey

2014-06-01

Conclusion: Semi-automated MR volumetric measurements can be used to determine atrophy in hippocampus, caudate nucleus and entorhinal cortex which aided in discrimination of healthy elderly control subjects from subjects with AD and MCI and predict clinical decline of MCI leading to increase the efficiency of clinical treatments, delay institutionalization and improve cognition and behavioral symptoms.

Analytical solution for stress, strain and plastic instability of pressurized pipes with volumetric flaws

Energy Technology Data Exchange (ETDEWEB)

Cunha, Sergio B., E-mail: sbcunha@petrobras.com.br [PETROBRAS/TRANSPETRO, Av. Pres. Vargas 328 - 7th floor, Rio de Janeiro, RJ 20091-060 (Brazil); Netto, Theodoro A., E-mail: tanetto@lts.coppe.ufrj.br [COPPE, Federal University ot Rio de Janeiro, Ocean Engineering Department, PO BOX 68508, Rio de Janeiro - RJ (Brazil)

2012-01-15

The mechanical behavior of internally pressurized pipes with volumetric flaws is analyzed. The two possible modes of circumferentially straining the pipe wall are identified and associated to hypothesized geometries. The radial deformation that takes place by bending the pipe wall is studied by means of axisymmetric flaws and the membrane strain developed by unequal hoop deformation is analyzed with the help of narrow axial flaws. Linear elastic shell solutions for stress and strain are developed, the plastic behavior is studied and the maximum hoop stress at the flaw is related to the undamaged pipe hoop stress by means of stress concentration factors. The stress concentration factors are employed to obtain equations predicting the pressure at which the pipe fails by plastic instability for both types of flaw. These analytical solutions are validated by comparison with burst tests on 3 Double-Prime diameter pipes and finite element simulations. Forty-one burst tests were carried out and two materials with very dissimilar plastic behavior, carbon steel and austenitic stainless steel, were used in the experiments. Both the analytical and the numerical predictions showed good correlation with the experimentally observed burst pressures. - Highlights: Black-Right-Pointing-Pointer An analytical model for the burst of a pipe with a volumetric flaw is developed. Black-Right-Pointing-Pointer Deformation, strain and stress are modeled in the elastic and plastic domains. Black-Right-Pointing-Pointer The model is comprehensively validated by experiments and numerical simulations. Black-Right-Pointing-Pointer The burst pressure model's accuracy is equivalent to finite element simulations.

Volumetric visualization of anatomy for treatment planning

International Nuclear Information System (INIS)

Pelizzari, Charles A.; Grzeszczuk, Robert; Chen, George T. Y.; Heimann, Ruth; Haraf, Daniel J.; Vijayakumar, Srinivasan; Ryan, Martin J.

1996-01-01

Purpose: Delineation of volumes of interest for three-dimensional (3D) treatment planning is usually performed by contouring on two-dimensional sections. We explore the usage of segmentation-free volumetric rendering of the three-dimensional image data set for tumor and normal tissue visualization. Methods and Materials: Standard treatment planning computed tomography (CT) studies, with typically 5 to 10 mm slice thickness, and spiral CT studies with 3 mm slice thickness were used. The data were visualized using locally developed volume-rendering software. Similar to the method of Drebin et al., CT voxels are automatically assigned an opacity and other visual properties (e.g., color) based on a probabilistic classification into tissue types. Using volumetric compositing, a projection into the opacity-weighted volume is produced. Depth cueing, perspective, and gradient-based shading are incorporated to achieve realistic images. Unlike surface-rendered displays, no hand segmentation is required to produce detailed renditions of skin, muscle, or bony anatomy. By suitable manipulation of the opacity map, tissue classes can be made transparent, revealing muscle, vessels, or bone, for example. Manually supervised tissue masking allows irrelevant tissues overlying tumors or other structures of interest to be removed. Results: Very high-quality renditions are produced in from 5 s to 1 min on midrange computer workstations. In the pelvis, an anteroposterior (AP) volume rendered view from a typical planning CT scan clearly shows the skin and bony anatomy. A muscle opacity map permits clear visualization of the superficial thigh muscles, femoral veins, and arteries. Lymph nodes are seen in the femoral triangle. When overlying muscle and bone are cut away, the prostate, seminal vessels, bladder, and rectum are seen in 3D perspective. Similar results are obtained for thorax and for head and neck scans. Conclusion: Volumetric visualization of anatomy is useful in treatment

Volumetric property of glycine, L-serine, L-alanine and L-proline in aqueous solutions of 1-phenylpiperazinium tetrafluoroborate

International Nuclear Information System (INIS)

Xie, Hujun; Zhao, Lijiang; Liu, Chengcheng; Cao, Yifan; Lu, Xiaoxing; Lei, Qunfang; Fang, Wenjun

2016-01-01

Highlights: • Volumetric property of four amino acids in aqueous solutions of [Phpi][BF_4] were measured. • The standard partial molar volume, transparent partial molar volume and hydration number were calculated. • [Phpi][BF_4] interacts strongly with four kinds of amino acids. • Hydrophilic–hydrophobic and hydrophobic–hydrophobic interactions play the dominant roles in ternary systems. • The ternary systems are generated via multiple hydrogen bond interactions. - Abstract: The densities of aqueous solutions of glycine, L-serine, L-alanine, L-proline with the ionic liquid (IL), 1-phenylpiperazinium tetrafluoroborate ([Phpi][BF_4]) at the IL concentrations of (0.025, 0.055 and 0.100) mol·kg"−"1 have been measured at the temperatures of (298.15, 303.15 and 308.15) K. On the basis of the experimental results, the apparent molar volume (V_Φ), standard partial molar volume (V_Φ"0), transfer partial molar volume (Δ_t_rV_Φ"0) and hydration number (n_H) have been calculated. The hydrophilic–hydrophilic, hydrophobic–hydrophilic and hydrophobic–hydrophobic interactions are involved in the studied systems of {[Phpi][BF_4] + amino acids + H_2O. These volumetric parameters can help to understand the mixing effects and other complex biological processes between amino acids and ionic liquid aqueous solution.

Effects of Different Reconstruction Parameters on CT Volumetric Measurement 
of Pulmonary Nodules

Directory of Open Access Journals (Sweden)

Rongrong YANG

2012-02-01

Full Text Available Background and objective It has been proven that volumetric measurements could detect subtle changes in small pulmonary nodules in serial CT scans, and thus may play an important role in the follow-up of indeterminate pulmonary nodules and in differentiating malignant nodules from benign nodules. The current study aims to evaluate the effects of different reconstruction parameters on the volumetric measurements of pulmonary nodules in chest CT scans. Methods Thirty subjects who underwent chest CT scan because of indeterminate pulmonary nodules in General Hospital of Tianjin Medical University from December 2009 to August 2011 were retrospectively analyzed. A total of 52 pulmonary nodules were included, and all CT data were reconstructed using three reconstruction algorithms and three slice thicknesses. The volumetric measurements of the nodules were performed using the advanced lung analysis (ALA software. The effects of the reconstruction algorithms, slice thicknesses, and nodule diameters on the volumetric measurements were assessed using the multivariate analysis of variance for repeated measures, the correlation analysis, and the Bland-Altman method. Results The reconstruction algorithms (F=13.6, P<0.001 and slice thicknesses (F=4.4, P=0.02 had significant effects on the measured volume of pulmonary nodules. In addition, the coefficients of variation of nine measurements were inversely related with nodule diameter (r=-0.814, P<0.001. The volume measured at the 2.5 mm slice thickness had poor agreement with the volumes measured at 1.25 mm and 0.625 mm, respectively. Moreover, the best agreement was achieved between the slice thicknesses of 1.25 mm and 0.625 mm using the bone algorithm. Conclusion Reconstruction algorithms and slice thicknesses have significant impacts on the volumetric measurements of lung nodules, especially for the small nodules. Therefore, the reconstruction setting in serial CT scans should be consistent in the follow

Ultrahigh volumetric capacitance and cyclic stability of fluorine and nitrogen co-doped carbon microspheres

Science.gov (United States)

Zhou, Junshuang; Lian, Jie; Hou, Li; Zhang, Junchuan; Gou, Huiyang; Xia, Meirong; Zhao, Yufeng; Strobel, Timothy A.; Tao, Lu; Gao, Faming

2015-09-01

Highly porous nanostructures with large surface areas are typically employed for electrical double-layer capacitors to improve gravimetric energy storage capacity; however, high surface area carbon-based electrodes result in poor volumetric capacitance because of the low packing density of porous materials. Here, we demonstrate ultrahigh volumetric capacitance of 521 F cm-3 in aqueous electrolytes for non-porous carbon microsphere electrodes co-doped with fluorine and nitrogen synthesized by low-temperature solvothermal route, rivaling expensive RuO2 or MnO2 pseudo-capacitors. The new electrodes also exhibit excellent cyclic stability without capacitance loss after 10,000 cycles in both acidic and basic electrolytes at a high charge current of 5 A g-1. This work provides a new approach for designing high-performance electrodes with exceptional volumetric capacitance with high mass loadings and charge rates for long-lived electrochemical energy storage systems.

Kilohertz VLIF (volumetric laser induced fluorescence) measurements in a seeded free gas-phase jet in the transitionally turbulent flow regime

Science.gov (United States)

Wu, Yue; Xu, Wenjiang; Ma, Lin

2018-03-01

This paper reports the demonstration of instantaneous three-dimension (3D) measurements in turbulent flows at repetition rates up to 10 kHz using VLIF (volumetric laser induced fluorescence). The measurements were performed based on the LIF signal of iodine (I2) vapor seeded in the flow. The LIF signals of I2 vapor were generated volumetrically by a thick laser slab and then simultaneously captured by a total of seven cameras from different perspectives, based on which a 3D tomographic reconstruction was performed to obtain the 3D distribution of I2 vapor concentration. Single-shot measurements obtained in a duration of hundreds of nanoseconds (limited by the pulse duration of the excitation laser) were demonstrated in a 50 × 50 × 50 mm3 at a repetition rate up to 10 kHz. These measurements demonstrated the feasibility and potential of VLIF for resolving the 4D spatiotemporal dynamics of turbulent flows. Based on the experimental results obtained, this work also studied the VLIF signal level and its effects on the reconstruction accuracy under different the measurement conditions, illustrating the capabilities and limitations of performing high speed VLIF measurements.

Experimental determination of the degree of polarization of quantum states

DEFF Research Database (Denmark)

Kothe-Termén, Christian; Madsen, Lars Skovgaard; Andersen, Ulrik Lund

2013-01-01

We demonstrate experimental excitation-manifold-resolved polarization characterization of quantum states of light ranging from the few-photon to the many-photon level. In contrast to the traditional characterization of polarization that is based on the Stokes parameters, we experimentally determine...... the Stokes vector of each excitation manifold separately. Only for states with a given photon number do the methods coincide. For states with an indeterminate photon number, for example Gaussian states, the employed method gives a richer and more accurate description. We apply the method both in theory...

Validation by theoretical approach to the experimental estimation of efficiency for gamma spectrometry of gas in 100 ml standard flask

International Nuclear Information System (INIS)

Mohan, V.; Chudalayandi, K.; Sundaram, M.; Krishnamony, S.

1996-01-01

Estimation of gaseous activity forms an important component of air monitoring at Madras Atomic Power Station (MAPS). The gases of importance are argon 41 an air activation product and fission product noble gas xenon 133. For estimating the concentration, the experimental method is used in which a grab sample is collected in a 100 ml volumetric standard flask. The activity of gas is then computed by gamma spectrometry using a predetermined efficiency estimated experimentally. An attempt is made using theoretical approach to validate the experimental method of efficiency estimation. Two analytical models named relative flux model and absolute activity model were developed independently of each other. Attention is focussed on the efficiencies for 41 Ar and 133 Xe. Results show that the present method of sampling and analysis using 100 ml volumetric flask is adequate and acceptable. (author). 5 refs., 2 tabs

Experimental study of the conventional equation to determine a plate's moment of inertia

International Nuclear Information System (INIS)

Pintao, Carlos A F; Filho, Moacir P de Souza; Grandini, Carlos R; Hessel, Roberto

2004-01-01

In this work, we describe an experimental setup in which an electric current is used to determine the angular velocity attained by a plate rotating around a shaft in response to a torque applied for a given period. Based on this information, we show how the moment of inertia of a plate can be determined using a procedure that differs considerably from the ones most commonly used, which generally involve time measurements. Some experimental results are also presented which allow one to determine parameters such as the exponents and constant of the conventional equation of a plate's moment of inertia

Flexible MXene/Graphene Films for Ultrafast Supercapacitors with Outstanding Volumetric Capacitance

Energy Technology Data Exchange (ETDEWEB)

Yan, Jun [Drexel Univ., Philadelphia, PA (United States); Harbin Engineering Univ., Harbin (China); Ren, Chang E. [Drexel Univ., Philadelphia, PA (United States); Maleski, Kathleen [Drexel Univ., Philadelphia, PA (United States); Hatter, Christine B. [Drexel Univ., Philadelphia, PA (United States); Anasori, Babak [Drexel Univ., Philadelphia, PA (United States); Urbankowski, Patrick [Drexel Univ., Philadelphia, PA (United States); Sarycheva, Asya [Drexel Univ., Philadelphia, PA (United States); Gogotsi, Yury G. [Drexel Univ., Philadelphia, PA (United States)

2017-06-30

A strategy to prepare flexible and conductive MXene/graphene (reduced graphene oxide, rGO) supercapacitor electrodes by using electrostatic self-assembly between positively charged rGO modified with poly(diallyldimethylammonium chloride) and negatively charged titanium carbide MXene nanosheets is presented. After electrostatic assembly, rGO nanosheets are inserted in-between MXene layers. As a result, the self-restacking of MXene nanosheets is effectively prevented, leading to a considerably increased interlayer spacing. Accelerated diffusion of electrolyte ions enables more electroactive sites to become accessible. The freestanding MXene/rGO-5 wt% electrode displays a volumetric capacitance of 1040 F cm^–3 at a scan rate of 2 mV s^–1, an impressive rate capability with 61% capacitance retention at 1 V s^–1 and long cycle life. Moreover, the fabricated binder-free symmetric supercapacitor shows an ultrahigh volumetric energy density of 32.6 Wh L^–1, which is among the highest values reported for carbon and MXene based materials in aqueous electrolytes. Furthermore, this work provides fundamental insight into the effect of interlayer spacing on the electrochemical performance of 2D hybrid materials and sheds light on the design of next-generation flexible, portable and highly integrated supercapacitors with high volumetric and rate performances.

Prediction of thresholds and latency on the basis of experimentally determined impulse responses

NARCIS (Netherlands)

Blommaert, F.J.J.; Roufs, J.A.J.

As was shown before (Roufs and Blommaert 1981), temporal impluse responsses and step responses can be obtained psychophysically using a driftcorrecting perturbation technique. In this paper, experimentally determined impulse responses are given for eight subjects using different experimental

Experimental data on heat flux distribution from a volumetrically heated pool with frozen boundaries

International Nuclear Information System (INIS)

Helle, Maria; Kymaelaeinen, Olli; Tuomisto, Harri

1999-01-01

The COPO II experiments are confirmatory experiments and a continuation project to the earlier COPO I experiments. As in COPO 1, a molten corium pool on the lower head of a RPV is simulated by a two - dimensional slice of it in linear scale 1:2. The corium is simulated by water-zinc sulfate solution with volumetric Joule heating. The heat flux distribution on the boundaries and the temperature distribution in the pool are measured. The major new feature in COPO II is the cooling arrangement which is based on circulation of liquid nitrogen on the outside of the pool boundaries. The use of liquid nitrogen leads to formation of ice on the inside of boundaries. Two geometrically different versions of the COPO II facility have been constructed: one with a tori-spherical bottom shape, simulating the RPV of a VVER-440 reactor as COPO I, and another one with semicircular bottom simulating a western PWR such as AP600. The modified Rayleigh number in the COPO II experiments corresponds to the one in a prototypic corium pool (∼ 10 15 ). This paper reports results from the COPO II-Lo and COPO II-AP experiments with homogenous pool. Results indicate that the upward heat fluxes are in agreement with the results of the COPO I experiments. Also, as expected, the time averaged upward heat flux profile was relatively flat. On the other hand, the heat fluxes at the side and bottom boundaries of the pool were slightly higher in COPO II-Lo than in COPO I. In COPO II-AP, the average heat transfer coefficients to the curved boundary were higher than predicted by Jahn's and Mayinger's correlation, but slightly lower than in BALI experiments. (authors)

Volumetric real-time imaging using a CMUT ring array.

Science.gov (United States)

Choe, Jung Woo; Oralkan, Ömer; Nikoozadeh, Amin; Gencel, Mustafa; Stephens, Douglas N; O'Donnell, Matthew; Sahn, David J; Khuri-Yakub, Butrus T

2012-06-01

A ring array provides a very suitable geometry for forward-looking volumetric intracardiac and intravascular ultrasound imaging. We fabricated an annular 64-element capacitive micromachined ultrasonic transducer (CMUT) array featuring a 10-MHz operating frequency and a 1.27-mm outer radius. A custom software suite was developed to run on a PC-based imaging system for real-time imaging using this device. This paper presents simulated and experimental imaging results for the described CMUT ring array. Three different imaging methods--flash, classic phased array (CPA), and synthetic phased array (SPA)--were used in the study. For SPA imaging, two techniques to improve the image quality--Hadamard coding and aperture weighting--were also applied. The results show that SPA with Hadamard coding and aperture weighting is a good option for ring-array imaging. Compared with CPA, it achieves better image resolution and comparable signal-to-noise ratio at a much faster image acquisition rate. Using this method, a fast frame rate of up to 463 volumes per second is achievable if limited only by the ultrasound time of flight; with the described system we reconstructed three cross-sectional images in real-time at 10 frames per second, which was limited by the computation time in synthetic beamforming.

On the experimental determination of the one-way speed of light

International Nuclear Information System (INIS)

Perez, Israel

2011-01-01

In this paper the question of the isotropy of the one-way speed of light is addressed from an experimental perspective. In particular, we analyse two experimental methods commonly used in its determination. The analysis is aimed at clarifying the view that the one-way speed of light cannot be determined by techniques in which physical entities close paths. The procedure employed here will provide epistemological tools so that physicists understand that a direct measurement of the speed not only of light but of any physical entity is by no means trivial. Our results shed light on the physics behind the experiments which may be of interest for both physicists with an elemental knowledge in special relativity and philosophers of science.

On the experimental determination of the one-way speed of light

Energy Technology Data Exchange (ETDEWEB)

Perez, Israel, E-mail: cooguion@yahoo.com, E-mail: iperez@cicese.mx [Department of Applied Physics, Optics Division, CICESE, Carretera Ensena da-Tijuana 3918, Zona Playitas, CP 22860, Ensenada, Baja California (Mexico)

2011-07-15

In this paper the question of the isotropy of the one-way speed of light is addressed from an experimental perspective. In particular, we analyse two experimental methods commonly used in its determination. The analysis is aimed at clarifying the view that the one-way speed of light cannot be determined by techniques in which physical entities close paths. The procedure employed here will provide epistemological tools so that physicists understand that a direct measurement of the speed not only of light but of any physical entity is by no means trivial. Our results shed light on the physics behind the experiments which may be of interest for both physicists with an elemental knowledge in special relativity and philosophers of science.

Rapidly-steered single-element ultrasound for real-time volumetric imaging and guidance

Science.gov (United States)

Stauber, Mark; Western, Craig; Solek, Roman; Salisbury, Kenneth; Hristov, Dmitre; Schlosser, Jeffrey

2016-03-01

Volumetric ultrasound (US) imaging has the potential to provide real-time anatomical imaging with high soft-tissue contrast in a variety of diagnostic and therapeutic guidance applications. However, existing volumetric US machines utilize "wobbling" linear phased array or matrix phased array transducers which are costly to manufacture and necessitate bulky external processing units. To drastically reduce cost, improve portability, and reduce footprint, we propose a rapidly-steered single-element volumetric US imaging system. In this paper we explore the feasibility of this system with a proof-of-concept single-element volumetric US imaging device. The device uses a multi-directional raster-scan technique to generate a series of two-dimensional (2D) slices that were reconstructed into three-dimensional (3D) volumes. At 15 cm depth, 90° lateral field of view (FOV), and 20° elevation FOV, the device produced 20-slice volumes at a rate of 0.8 Hz. Imaging performance was evaluated using an US phantom. Spatial resolution was 2.0 mm, 4.7 mm, and 5.0 mm in the axial, lateral, and elevational directions at 7.5 cm. Relative motion of phantom targets were automatically tracked within US volumes with a mean error of -0.3+/-0.3 mm, -0.3+/-0.3 mm, and -0.1+/-0.5 mm in the axial, lateral, and elevational directions, respectively. The device exhibited a mean spatial distortion error of 0.3+/-0.9 mm, 0.4+/-0.7 mm, and -0.3+/-1.9 in the axial, lateral, and elevational directions. With a production cost near $1000, the performance characteristics of the proposed system make it an ideal candidate for diagnostic and image-guided therapy applications where form factor and low cost are paramount.

Semi-automated volumetric analysis of lymph node metastases in patients with malignant melanoma stage III/IV-A feasibility study

International Nuclear Information System (INIS)

Fabel, M.; Tengg-Kobligk, H. von; Giesel, F.L.; Delorme, S.; Kauczor, H.-U.; Bornemann, L.; Dicken, V.; Kopp-Schneider, A.; Moser, C.

2008-01-01

Therapy monitoring in oncological patient care requires accurate and reliable imaging and post-processing methods. RECIST criteria are the current standard, with inherent disadvantages. The aim of this study was to investigate the feasibility of semi-automated volumetric analysis of lymph node metastases in patients with malignant melanoma compared to manual volumetric analysis and RECIST. Multislice CT was performed in 47 patients, covering the chest, abdomen and pelvis. In total, 227 suspicious, enlarged lymph nodes were evaluated retrospectively by two radiologists regarding diameters (RECIST), manually measured volume by placement of ROIs and semi-automated volumetric analysis. Volume (ml), quality of segmentation (++/-) and time effort (s) were evaluated in the study. The semi-automated volumetric analysis software tool was rated acceptable to excellent in 81% of all cases (reader 1) and 79% (reader 2). Median time for the entire segmentation process and necessary corrections was shorter with the semi-automated software than by manual segmentation. Bland-Altman plots showed a significantly lower interobserver variability for semi-automated volumetric than for RECIST measurements. The study demonstrated feasibility of volumetric analysis of lymph node metastases. The software allows a fast and robust segmentation in up to 80% of all cases. Ease of use and time needed are acceptable for application in the clinical routine. Variability and interuser bias were reduced to about one third of the values found for RECIST measurements. (orig.)

Experimental-calculation technique for Ksub(IC) determination using the samples of decreased dimensions

International Nuclear Information System (INIS)

Vinokurov, V.A.; Dymshits, A.V.; Pirusskij, M.V.; Ovsyannikov, B.M.; Kononov, V.V.

1981-01-01

A possibility to decrease the size of samples, which is necessary for the reliable determination of fractUre toughness Ksub(1c), is established. The dependences of crack-resistance caracteristics on the sample dimensions are determined experimentally. The static bending tests are made using the 1251 model of ''Instron'' installation with a specially designed device. The samples of the 20KhNMF steel have been tested. It is shown that the Ksub(1c) value, determined for the samples with the largest netto cross section (50x100 rm), is considerably lower than Ksub(1c) values, determined for the samples with the decreased sizes. it is shown that the developed experimental-calculated method of Ksub(1c) determination can be practically used for the samples of the decreased sizes with the introduction of the corresponding amendment coefficient [ru

Ideal femoral head size in total hip arthroplasty balances stability and volumetric wear.

Science.gov (United States)

Cross, Michael B; Nam, Denis; Mayman, David J

2012-10-01

Over the last several years, a trend towards increasing femoral head size in total hip arthroplasty to improve stability and impingement free range of motion has been observed. The specific questions we sought to answer in our review were: (1) What are the potential advantages and disadvantages of metal-on-metal, ceramic-on-ceramic, and metal-on-polyethylene bearings? (2) What is effect that femoral head size has on joint kinematics? (3) What is the effect that large femoral heads have on bearing surface wear? A PubMed search and a review of 2012 Orthopaedic Research Society abstracts was performed and articles were chosen that directly answered components of the specific aims and that reported outcomes with contemporary implant designs or materials. A review of the literature suggests that increasing femoral head size decreases the risk of postoperative dislocation and improves impingement free range of motion; however, volumetric wear increases with large femoral heads on polyethylene and increases corrosion of the stem in large metal-on-metal modular total hip arthroplasty (THA); however, the risk of potentially developing osteolysis or adverse reactions to metal debris respectively is still unknown. Further, the effect of large femoral heads with ceramic-on-ceramic THA is unclear, due to limited availability and published data. Surgeons must balance the benefits of larger head size with the increased risk of volumetric wear when determining the appropriate head size for a given patient.

Volumetric brain differences in children with periventricular T2-signal hyperintensities: a grouping by gestational age at birth.

Science.gov (United States)

Panigrahy, A; Barnes, P D; Robertson, R L; Back, S A; Sleeper, L A; Sayre, J W; Kinney, H C; Volpe, J J

2001-09-01

The purpose of this study was to compare both the volumes of the lateral ventricles and the cerebral white matter with gestational age at birth of children with periventricular white matter (PVWM) T2-signal hyperintensities on MR images. The spectrum of neuromotor abnormalities associated with these hyperintensities was also determined. We retrospectively reviewed the MR images of 70 patients who were between the ages of 1 and 5 years and whose images showed PVWM T2-signal hyperintensities. The patients were divided into premature (n = 35 children) and term (n = 35) groups depending on their gestational age at birth. Volumetric analysis was performed on four standardized axial sections using T2-weighted images. Volumes of interest were digitized on the basis of gray-scale densities of signal intensities to define the hemispheric cerebral white matter and lateral ventricles. Age-adjusted comparisons of volumetric measurements between the premature and term groups were performed using analysis of covariance. The volume of the cerebral white matter was smaller in the premature group (54 +/- 2 cm(3)) than in the term group (79 +/- 3 cm(3), p group (30 +/- 2 cm(3)) than among those in the term group (13 +/- 1 cm(3), p groups whose PVWM T2-signal hyperintensities did not correlate with any neuromotor abnormalities but were associated with seizures or developmental delays. The differences in volumetric measurements of cerebral white matter and lateral ventricles in children with PVWM T2-signal hyperintensities are related to their gestational age at birth. Several neurologic motor abnormalities are found in children with such hyperintensities.

Need and trends of volumetric tests in recurring inspection of pressurized components in pressurized water reactors

International Nuclear Information System (INIS)

Bergemann, W.

1982-01-01

On the basis of the types of stress occurring in nuclear power plants and of practical results it has been shown that cracks in primary circuit components arise due to operating stresses in both the materials surfaces and the bulk of the materials. For this reason, volumetric materials testing is necessary in addition to surface testing. An outlook is given on the trends of volumetric testing. (author)

Electromagnetically controlled measuring device for measuring injection quantities in a diesel injection pump volumetrically. Elektromagnetisch gesteuerte Messvorrichtung zur volumetrischen Messung von Einspritzmengen einer Dieseleinspritzpumpe

Energy Technology Data Exchange (ETDEWEB)

Hoffmann, K H; Mueller, M; Decker, R; Huber, G

1990-11-22

The invention concerns a measuring device for volumetric measurements of injection quantities of a diesel injection pump which injects its contents into a volumetric chamber controlled electromagnetically by a discharge valve and enclosed by a non-impact gas pressure loaded volumetric vessel and effects a retreating movement of the latter. The device is provided with an inductive path controller fitted with a differential pair of coils containing an axially movable ferromagnetic core. The path controller forms a part of a lifter rod connected to the volumetric vessel. It gives an opening signal to the discharge valve after each retreat of the volumetric vessel and a closing signal as soon as a defined height of suspension corresponding to the original position of the volumetric vessel after its return is reached.

FMC/TFM experimental comparisons

Science.gov (United States)

Spencer, Roger; Sunderman, Ruth; Todorov, Evgueni

2018-04-01

Ultrasonic full matrix capture/total focusing method (FMC/TFM) technology has progressed significantly over the past few years and has seen increased use in industry. The technology has the potential to provide better detection and measurement capabilities for weld flaws, as well as, many other applications including additive manufacturing. This project looked at the effectiveness of FMC/TFM for detection and sizing of both planar and volumetric flaw types. FMC/TFM experimental data was collected and processed using multiple combinations of probe types and wave propagation modes. The data was then compared to typical ultrasonic phased-array results, as well as FMC/TFM inspection simulations.

Improved correlation between CT emphysema quantification and pulmonary function test by density correction of volumetric CT data based on air and aortic density

International Nuclear Information System (INIS)

Kim, Song Soo; Seo, Joon Beom; Kim, Namkug; Chae, Eun Jin; Lee, Young Kyung; Oh, Yeon Mok; Lee, Sang Do

2014-01-01

Objectives: To determine the improvement of emphysema quantification with density correction and to determine the optimal site to use for air density correction on volumetric computed tomography (CT). Methods: Seventy-eight CT scans of COPD patients (GOLD II–IV, smoking history 39.2 ± 25.3 pack-years) were obtained from several single-vendor 16-MDCT scanners. After density measurement of aorta, tracheal- and external air, volumetric CT density correction was conducted (two reference values: air, −1000 HU/blood, +50 HU). Using in-house software, emphysema index (EI) and mean lung density (MLD) were calculated. Differences in air densities, MLD and EI prior to and after density correction were evaluated (paired t-test). Correlation between those parameters and FEV 1 and FEV 1 /FVC were compared (age- and sex adjusted partial correlation analysis). Results: Measured densities (HU) of tracheal- and external air differed significantly (−990 ± 14, −1016 ± 9, P < 0.001). MLD and EI on original CT data, after density correction using tracheal- and external air also differed significantly (MLD: −874.9 ± 27.6 vs. −882.3 ± 24.9 vs. −860.5 ± 26.6; EI: 16.8 ± 13.4 vs. 21.1 ± 14.5 vs. 9.7 ± 10.5, respectively, P < 0.001). The correlation coefficients between CT quantification indices and FEV 1 , and FEV 1 /FVC increased after density correction. The tracheal air correction showed better results than the external air correction. Conclusion: Density correction of volumetric CT data can improve correlations of emphysema quantification and PFT

40 CFR 63.115 - Process vent provisions-methods and procedures for process vent group determination.

Science.gov (United States)

2010-07-01

... this section. (2) The gas volumetric flow rate shall be determined using Method 2, 2A, 2C, or 2D of 40... accepted chemical engineering principles, measurable process parameters, or physical or chemical laws or...)(3) of this section. (i) The vent stream volumetric flow rate (Qs), in standard cubic meters per...

Volumetric changes and clinical outcome for petroclival meningiomas after primary treatment with Gamma Knife radiosurgery.

Science.gov (United States)

Sadik, Zjiwar H A; Lie, Suan Te; Leenstra, Sieger; Hanssens, Patrick E J

2018-01-26

OBJECTIVE Petroclival meningiomas (PCMs) can cause devastating clinical symptoms due to mass effect on cranial nerves (CNs); thus, patients harboring these tumors need treatment. Many neurosurgeons advocate for microsurgery because removal of the tumor can provide relief or result in symptom disappearance. Gamma Knife radiosurgery (GKRS) is often an alternative for surgery because it can cause tumor shrinkage with improvement of symptoms. This study evaluates qualitative volumetric changes of PCM after primary GKRS and its impact on clinical symptoms. METHODS The authors performed a retrospective study of patients with PCM who underwent primary GKRS between 2003 and 2015 at the Gamma Knife Center of the Elisabeth-Tweesteden Hospital in Tilburg, the Netherlands. This study yields 53 patients. In this study the authors concentrate on qualitative volumetric tumor changes, local tumor control rate, and the effect of the treatment on trigeminal neuralgia (TN). RESULTS Local tumor control was 98% at 5 years and 93% at 7 years (Kaplan-Meier estimates). More than 90% of the tumors showed regression in volume during the first 5 years. The mean volumetric tumor decrease was 21.2%, 27.1%, and 31% at 1, 3, and 6 years of follow-up, respectively. Improvement in TN was achieved in 61%, 67%, and 70% of the cases at 1, 2, and 3 years of follow-up, respectively. This was associated with a mean volumetric tumor decrease of 25% at the 1-year follow-up to 32% at the 3-year follow-up. CONCLUSIONS GKRS for PCMs yields a high tumor control rate with a low incidence of neurological deficits. Many patients with TN due to PCM experienced improvement in TN after radiosurgery. GKRS achieves significant volumetric tumor decrease in the first years of follow-up and thereafter.

WE-D-BRB-03: Current State of Volumetric Image Guidance for Proton Therapy

Energy Technology Data Exchange (ETDEWEB)

Hua, C. [St. Jude Children’s Research Hospital (United States)

2016-06-15

The goal of this session is to review the physics of proton therapy, treatment planning techniques, and the use of volumetric imaging in proton therapy. The course material covers the physics of proton interaction with matter and physical characteristics of clinical proton beams. It will provide information on proton delivery systems and beam delivery techniques for double scattering (DS), uniform scanning (US), and pencil beam scanning (PBS). The session covers the treatment planning strategies used in DS, US, and PBS for various anatomical sites, methods to address uncertainties in proton therapy and uncertainty mitigation to generate robust treatment plans. It introduces the audience to the current status of image guided proton therapy and clinical applications of CBCT for proton therapy. It outlines the importance of volumetric imaging in proton therapy. Learning Objectives: Gain knowledge in proton therapy physics, and treatment planning for proton therapy including intensity modulated proton therapy. The current state of volumetric image guidance equipment in proton therapy. Clinical applications of CBCT and its advantage over orthogonal imaging for proton therapy. B. Teo, B.K Teo had received travel funds from IBA in 2015.

WE-D-BRB-03: Current State of Volumetric Image Guidance for Proton Therapy

International Nuclear Information System (INIS)

Hua, C.

2016-01-01

The goal of this session is to review the physics of proton therapy, treatment planning techniques, and the use of volumetric imaging in proton therapy. The course material covers the physics of proton interaction with matter and physical characteristics of clinical proton beams. It will provide information on proton delivery systems and beam delivery techniques for double scattering (DS), uniform scanning (US), and pencil beam scanning (PBS). The session covers the treatment planning strategies used in DS, US, and PBS for various anatomical sites, methods to address uncertainties in proton therapy and uncertainty mitigation to generate robust treatment plans. It introduces the audience to the current status of image guided proton therapy and clinical applications of CBCT for proton therapy. It outlines the importance of volumetric imaging in proton therapy. Learning Objectives: Gain knowledge in proton therapy physics, and treatment planning for proton therapy including intensity modulated proton therapy. The current state of volumetric image guidance equipment in proton therapy. Clinical applications of CBCT and its advantage over orthogonal imaging for proton therapy. B. Teo, B.K Teo had received travel funds from IBA in 2015.

The importance of accurate anatomic assessment for the volumetric analysis of the amygdala

Directory of Open Access Journals (Sweden)

L. Bonilha

2005-03-01

Full Text Available There is a wide range of values reported in volumetric studies of the amygdala. The use of single plane thick magnetic resonance imaging (MRI may prevent the correct visualization of anatomic landmarks and yield imprecise results. To assess whether there is a difference between volumetric analysis of the amygdala performed with single plane MRI 3-mm slices and with multiplanar analysis of MRI 1-mm slices, we studied healthy subjects and patients with temporal lobe epilepsy. We performed manual delineation of the amygdala on T1-weighted inversion recovery, 3-mm coronal slices and manual delineation of the amygdala on three-dimensional volumetric T1-weighted images with 1-mm slice thickness. The data were compared using a dependent t-test. There was a significant difference between the volumes obtained by the coronal plane-based measurements and the volumes obtained by three-dimensional analysis (P < 0.001. An incorrect estimate of the amygdala volume may preclude a correct analysis of the biological effects of alterations in amygdala volume. Three-dimensional analysis is preferred because it is based on more extensive anatomical assessment and the results are similar to those obtained in post-mortem studies.

Low-cost Volumetric Ultrasound by Augmentation of 2D Systems: Design and Prototype.

Science.gov (United States)

Herickhoff, Carl D; Morgan, Matthew R; Broder, Joshua S; Dahl, Jeremy J

2018-01-01

Conventional two-dimensional (2D) ultrasound imaging is a powerful diagnostic tool in the hands of an experienced user, yet 2D ultrasound remains clinically underutilized and inherently incomplete, with output being very operator dependent. Volumetric ultrasound systems can more fully capture a three-dimensional (3D) region of interest, but current 3D systems require specialized transducers, are prohibitively expensive for many clinical departments, and do not register image orientation with respect to the patient; these systems are designed to provide improved workflow rather than operator independence. This work investigates whether it is possible to add volumetric 3D imaging capability to existing 2D ultrasound systems at minimal cost, providing a practical means of reducing operator dependence in ultrasound. In this paper, we present a low-cost method to make 2D ultrasound systems capable of quality volumetric image acquisition: we present the general system design and image acquisition method, including the use of a probe-mounted orientation sensor, a simple probe fixture prototype, and an offline volume reconstruction technique. We demonstrate initial results of the method, implemented using a Verasonics Vantage research scanner.

Assessing vertebral fracture risk on volumetric quantitative computed tomography by geometric characterization of trabecular bone structure

Science.gov (United States)

Checefsky, Walter A.; Abidin, Anas Z.; Nagarajan, Mahesh B.; Bauer, Jan S.; Baum, Thomas; Wismüller, Axel

2016-03-01

The current clinical standard for measuring Bone Mineral Density (BMD) is dual X-ray absorptiometry, however more recently BMD derived from volumetric quantitative computed tomography has been shown to demonstrate a high association with spinal fracture susceptibility. In this study, we propose a method of fracture risk assessment using structural properties of trabecular bone in spinal vertebrae. Experimental data was acquired via axial multi-detector CT (MDCT) from 12 spinal vertebrae specimens using a whole-body 256-row CT scanner with a dedicated calibration phantom. Common image processing methods were used to annotate the trabecular compartment in the vertebral slices creating a circular region of interest (ROI) that excluded cortical bone for each slice. The pixels inside the ROI were converted to values indicative of BMD. High dimensional geometrical features were derived using the scaling index method (SIM) at different radii and scaling factors (SF). The mean BMD values within the ROI were then extracted and used in conjunction with a support vector machine to predict the failure load of the specimens. Prediction performance was measured using the root-mean-square error (RMSE) metric and determined that SIM combined with mean BMD features (RMSE = 0.82 +/- 0.37) outperformed MDCT-measured mean BMD (RMSE = 1.11 +/- 0.33) (p biomechanical strength prediction in vertebrae can be significantly improved through the use of SIM-derived texture features from trabecular bone.

Nitrogen-Doped Holey Graphene as an Anode for Lithium-Ion Batteries with High Volumetric Energy Density and Long Cycle Life.

Science.gov (United States)

Xu, Jiantie; Lin, Yi; Connell, John W; Dai, Liming

2015-12-01

Nitrogen-doped holey graphene (N-hG) as an anode material for lithium-ion batteries has delivered a maximum volumetric capacity of 384 mAh cm(-3) with an excellent long-term cycling life up to 6000 cycles, and as an electrochemical capacitor has delivered a maximum volumetric energy density of 171.2 Wh L(-1) and a volumetric capacitance of 201.6 F cm(-3) . © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Somatic mutations associated with MRI-derived volumetric features in glioblastoma

Energy Technology Data Exchange (ETDEWEB)

Gutman, David A.; Dunn, William D. [Emory University School of Medicine, Departments of Neurology, Atlanta, GA (United States); Emory University School of Medicine, Biomedical Informatics, Atlanta, GA (United States); Grossmann, Patrick; Alexander, Brian M. [Harvard Medical School, Department of Radiation Oncology, Dana-Farber Cancer Institute, Brigham and Women' s Hospital, Boston, MA (United States); Cooper, Lee A.D. [Emory University School of Medicine, Biomedical Informatics, Atlanta, GA (United States); Georgia Institute of Technology, Department of Biomedical Engineering, Atlanta, GA (United States); Holder, Chad A. [Emory University School of Medicine, Radiology and Imaging Sciences, Atlanta, GA (United States); Ligon, Keith L. [Brigham and Women' s Hospital, Harvard Medical School, Pathology, Dana-Farber Cancer Institute, Boston, MA (United States); Aerts, Hugo J.W.L. [Harvard Medical School, Department of Radiation Oncology, Dana-Farber Cancer Institute, Brigham and Women' s Hospital, Boston, MA (United States); Brigham and Women' s Hospital, Harvard Medical School, Radiology, Dana-Farber Cancer Institute, Boston, MA (United States)

2015-12-15

MR imaging can noninvasively visualize tumor phenotype characteristics at the macroscopic level. Here, we investigated whether somatic mutations are associated with and can be predicted by MRI-derived tumor imaging features of glioblastoma (GBM). Seventy-six GBM patients were identified from The Cancer Imaging Archive for whom preoperative T1-contrast (T1C) and T2-FLAIR MR images were available. For each tumor, a set of volumetric imaging features and their ratios were measured, including necrosis, contrast enhancing, and edema volumes. Imaging genomics analysis assessed the association of these features with mutation status of nine genes frequently altered in adult GBM. Finally, area under the curve (AUC) analysis was conducted to evaluate the predictive performance of imaging features for mutational status. Our results demonstrate that MR imaging features are strongly associated with mutation status. For example, TP53-mutated tumors had significantly smaller contrast enhancing and necrosis volumes (p = 0.012 and 0.017, respectively) and RB1-mutated tumors had significantly smaller edema volumes (p = 0.015) compared to wild-type tumors. MRI volumetric features were also found to significantly predict mutational status. For example, AUC analysis results indicated that TP53, RB1, NF1, EGFR, and PDGFRA mutations could each be significantly predicted by at least one imaging feature. MRI-derived volumetric features are significantly associated with and predictive of several cancer-relevant, drug-targetable DNA mutations in glioblastoma. These results may shed insight into unique growth characteristics of individual tumors at the macroscopic level resulting from molecular events as well as increase the use of noninvasive imaging in personalized medicine. (orig.)

Agreement of mammographic measures of volumetric breast density to MRI.

Directory of Open Access Journals (Sweden)

Jeff Wang

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

Agreement of mammographic measures of volumetric breast density to MRI.

Science.gov (United States)

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

2013-01-01

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

Somatic mutations associated with MRI-derived volumetric features in glioblastoma

International Nuclear Information System (INIS)

Gutman, David A.; Dunn, William D.; Grossmann, Patrick; Alexander, Brian M.; Cooper, Lee A.D.; Holder, Chad A.; Ligon, Keith L.; Aerts, Hugo J.W.L.

2015-01-01

MR imaging can noninvasively visualize tumor phenotype characteristics at the macroscopic level. Here, we investigated whether somatic mutations are associated with and can be predicted by MRI-derived tumor imaging features of glioblastoma (GBM). Seventy-six GBM patients were identified from The Cancer Imaging Archive for whom preoperative T1-contrast (T1C) and T2-FLAIR MR images were available. For each tumor, a set of volumetric imaging features and their ratios were measured, including necrosis, contrast enhancing, and edema volumes. Imaging genomics analysis assessed the association of these features with mutation status of nine genes frequently altered in adult GBM. Finally, area under the curve (AUC) analysis was conducted to evaluate the predictive performance of imaging features for mutational status. Our results demonstrate that MR imaging features are strongly associated with mutation status. For example, TP53-mutated tumors had significantly smaller contrast enhancing and necrosis volumes (p = 0.012 and 0.017, respectively) and RB1-mutated tumors had significantly smaller edema volumes (p = 0.015) compared to wild-type tumors. MRI volumetric features were also found to significantly predict mutational status. For example, AUC analysis results indicated that TP53, RB1, NF1, EGFR, and PDGFRA mutations could each be significantly predicted by at least one imaging feature. MRI-derived volumetric features are significantly associated with and predictive of several cancer-relevant, drug-targetable DNA mutations in glioblastoma. These results may shed insight into unique growth characteristics of individual tumors at the macroscopic level resulting from molecular events as well as increase the use of noninvasive imaging in personalized medicine. (orig.)

Volumetric Real-Time Imaging Using a CMUT Ring Array

OpenAIRE

Choe, Jung Woo; Oralkan, Ömer; Nikoozadeh, Amin; Gencel, Mustafa; Stephens, Douglas N.; O’Donnell, Matthew; Sahn, David J.; Khuri-Yakub, Butrus T.

2012-01-01

A ring array provides a very suitable geometry for forward-looking volumetric intracardiac and intravascular ultrasound imaging. We fabricated an annular 64-element capacitive micromachined ultrasonic transducer (CMUT) array featuring a 10-MHz operating frequency and a 1.27-mm outer radius. A custom software suite was developed to run on a PC-based imaging system for real-time imaging using this device.

In-Situ Spatial Variability Of Thermal Conductivity And Volumetric ...

African Journals Online (AJOL)

Studies of spatial variability of thermal conductivity and volumetric water content of silty topsoil were conduct-ed on a 0.6 ha site at Abeokuta, South-Western Nigeria. The thermal conductivity (k) was measured at depths of up to 0.06 m along four parallel profiles of 200 m long and at an average temperature of 25 C, using ...

ScanSort{sup SM} at Whiteshell Laboratories for sorting of experimental cesium pond soil

Energy Technology Data Exchange (ETDEWEB)

Downey, H., E-mail: heath.downey@amecfw.com [Amec Foster Wheeler, Portland, ME (United States)

2015-07-01

The ScanSort{sup SM} soil sorting system is a unique and efficient radiological instrument used for measuring and sorting bulk soils and volumetric materials. The system performs automatic radioassay and segregation of preconditioned material using a gamma spectroscopy system mounted above a conveyor belt. It was deployed to the Whiteshell Laboratories site to process the excavated soils generated during the decommissioning of the former Experimental Cesium Pond. The ScanSort{sup SM} system was utilized to segregate material with Cs-137 concentrations above the established site unrestricted release and restricted site reuse levels as well as demonstrated the ability to accurately determine the radioactivity concentrations of the radiologically-impacted material and to confidently segregate volumes of that material for appropriate final disposition. (author)

VOLUMETRIC METHOD FOR EVALUATION OF BEACHES VARIABILITY BASED ON GIS-TOOLS

Directory of Open Access Journals (Sweden)

V. V. Dolotov

2015-01-01

Full Text Available In frame of cadastral beach evaluation the volumetric method of natural variability index is proposed. It base on spatial calculations with Cut-Fill method and volume accounting ofboththe common beach contour and specific areas for the each time.

The analysis of colour uniformity for a volumetric display based on a rotating LED array

International Nuclear Information System (INIS)

Wu, Jiang; Liu, Xu; Yan, Caijie; Xia, XinXing; Li, Haifeng

2011-01-01

There is a colour nonuniformity zone existing in three-dimensional (3D) volumetric displays which is based on the rotating colour light-emitting diode (LED) array. We analyse the reason for the colour nonuniformity zone by measuring the light intensity distribution and chromaticity coordinates of the LED in the volumetric display. Two boundaries of the colour nonuniformity zone are calculated. We measure the colour uniformities for a single cuboid of 3*3*4 voxels to display red, green, blue and white colour in different horizontal viewing angles, and for 64 cuboids distributed in the whole cylindrical image space with a fixed viewpoint. To evaluate the colour uniformity of a 3D image, we propose three evaluation indices of colour uniformity: the average of colour difference, the maximum colour difference and the variance of colour difference. The measurement results show that the character of colour uniformity is different for the 3D volumetric display and the two-dimensional display

Analytic Intermodel Consistent Modeling of Volumetric Human Lung Dynamics.

Science.gov (United States)

Ilegbusi, Olusegun; Seyfi, Behnaz; Neylon, John; Santhanam, Anand P

2015-10-01

Human lung undergoes breathing-induced deformation in the form of inhalation and exhalation. Modeling the dynamics is numerically complicated by the lack of information on lung elastic behavior and fluid-structure interactions between air and the tissue. A mathematical method is developed to integrate deformation results from a deformable image registration (DIR) and physics-based modeling approaches in order to represent consistent volumetric lung dynamics. The computational fluid dynamics (CFD) simulation assumes the lung is a poro-elastic medium with spatially distributed elastic property. Simulation is performed on a 3D lung geometry reconstructed from four-dimensional computed tomography (4DCT) dataset of a human subject. The heterogeneous Young's modulus (YM) is estimated from a linear elastic deformation model with the same lung geometry and 4D lung DIR. The deformation obtained from the CFD is then coupled with the displacement obtained from the 4D lung DIR by means of the Tikhonov regularization (TR) algorithm. The numerical results include 4DCT registration, CFD, and optimal displacement data which collectively provide consistent estimate of the volumetric lung dynamics. The fusion method is validated by comparing the optimal displacement with the results obtained from the 4DCT registration.

A spiral-based volumetric acquisition for MR temperature imaging.

Science.gov (United States)

Fielden, Samuel W; Feng, Xue; Zhao, Li; Miller, G Wilson; Geeslin, Matthew; Dallapiazza, Robert F; Elias, W Jeffrey; Wintermark, Max; Butts Pauly, Kim; Meyer, Craig H

2018-06-01

To develop a rapid pulse sequence for volumetric MR thermometry. Simulations were carried out to assess temperature deviation, focal spot distortion/blurring, and focal spot shift across a range of readout durations and maximum temperatures for Cartesian, spiral-out, and retraced spiral-in/out (RIO) trajectories. The RIO trajectory was applied for stack-of-spirals 3D imaging on a real-time imaging platform and preliminary evaluation was carried out compared to a standard 2D sequence in vivo using a swine brain model, comparing maximum and mean temperatures measured between the two methods, as well as the temporal standard deviation measured by the two methods. In simulations, low-bandwidth Cartesian trajectories showed substantial shift of the focal spot, whereas both spiral trajectories showed no shift while maintaining focal spot geometry. In vivo, the 3D sequence achieved real-time 4D monitoring of thermometry, with an update time of 2.9-3.3 s. Spiral imaging, and RIO imaging in particular, is an effective way to speed up volumetric MR thermometry. Magn Reson Med 79:3122-3127, 2018. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

Determination of Thermal Conductivity of Silicate Matrix for Applications in Effective Media Theory

Science.gov (United States)

Fiala, Lukáš; Jerman, Miloš; Reiterman, Pavel; Černý, Robert

2018-02-01

Silicate materials have an irreplaceable role in the construction industry. They are mainly represented by cement-based- or lime-based materials, such as concrete, cement mortar, or lime plaster, and consist of three phases: the solid matrix and air and water present in the pores. Therefore, their effective thermal conductivity depends on thermal conductivities of the involved phases. Due to the time-consuming experimental determination of the effective thermal conductivity, its calculation by means of homogenization techniques presents a reasonable alternative. In the homogenization theory, both volumetric content and particular property of each phase need to be identified. For porous materials the most problematic part is to accurately identify thermal conductivity of the solid matrix. Due to the complex composition of silicate materials, the thermal conductivity of the matrix can be determined only approximately, based on the knowledge of thermal conductivities of its major compounds. In this paper, the thermal conductivity of silicate matrix is determined using the measurement of a sufficiently large set of experimental data. Cement pastes with different open porosities are prepared, dried, and their effective thermal conductivity is determined using a transient heat-pulse method. The thermal conductivity of the matrix is calculated by means of extrapolation of the effective thermal conductivity versus porosity functions to zero porosity. Its practical applicability is demonstrated by calculating the effective thermal conductivity of a three-phase silicate material and comparing it with experimental data.

A Hierarchical Volumetric Shadow Algorithm for Single Scattering

OpenAIRE

Baran, Ilya; Chen, Jiawen; Ragan-Kelley, Jonathan Millar; Durand, Fredo; Lehtinen, Jaakko

2010-01-01

Volumetric effects such as beams of light through participating media are an important component in the appearance of the natural world. Many such effects can be faithfully modeled by a single scattering medium. In the presence of shadows, rendering these effects can be prohibitively expensive: current algorithms are based on ray marching, i.e., integrating the illumination scattered towards the camera along each view ray, modulated by visibility to the light source at each sample. Visibility...

Exploring Parallel Algorithms for Volumetric Mass-Spring-Damper Models in CUDA

DEFF Research Database (Denmark)

Rasmusson, Allan; Mosegaard, Jesper; Sørensen, Thomas Sangild

2008-01-01

) from Nvidia. This paper investigates multiple implementations of volumetric Mass-Spring-Damper systems in CUDA. The obtained performance is compared to previous implementations utilizing the GPU through the OpenGL graphics API. We find that both performance and optimization strategies differ widely...

Thermodynamic and volumetric databases and software for magnesium alloys

Science.gov (United States)

Kang, Youn-Bae; Aliravci, Celil; Spencer, Philip J.; Eriksson, Gunnar; Fuerst, Carlton D.; Chartrand, Patrice; Pelton, Arthur D.

2009-05-01

Extensive databases for the thermodynamic and volumetric properties of magnesium alloys have been prepared by critical evaluation, modeling, and optimization of available data. Software has been developed to access the databases to calculate equilibrium phase diagrams, heat effects, etc., and to follow the course of equilibrium or Scheil-Gulliver cooling, calculating not only the amounts of the individual phases, but also of the microstructural constituents.

PEMODELAN OBYEK TIGA DIMENSI DARI GAMBAR SINTETIS DUA DIMENSI DENGAN PENDEKATAN VOLUMETRIC

Directory of Open Access Journals (Sweden)

Rudy Adipranata

2005-01-01

Full Text Available In this paper, we implemented 3D object modeling from 2D input images. Modeling is performed by using volumetric reconstruction approaches by using volumetric reconstruction approaches, the 3D space is tesselated into discrete volumes called voxels. We use voxel coloring method to reconstruct 3D object from synthetic input images by using voxel coloring, we can get photorealistic result and also has advantage to solve occlusion problem that occur in many case of 3D reconstruction. Photorealistic 3D object reconstruction is a challenging problem in computer graphics and still an active area nowadays. Many applications that make use the result of reconstruction, include virtual reality, augmented reality, 3D games, and another 3D applications. Voxel coloring considered the reconstruction problem as a color reconstruction problem, instead of shape reconstruction problem. This method works by discretizing scene space into voxels, then traversed and colored those voxels in special order. The result is photorealitstic 3D object. Abstract in Bahasa Indonesia : Dalam penelitian ini dilakukan implementasi untuk pemodelan obyek tiga dimensi yang berasal dari gambar dua dimensi. Pemodelan ini dilakukan dengan menggunakan pendekatan volumetric. Dengan menggunakan pendekatan volumetric, ruang tiga dimensi dibagi menjadi bentuk diskrit yang disebut voxel. Kemudian pada voxel-voxel tersebut dilakukan metode pewarnaan voxel untuk mendapatkan hasil berupa obyek tiga dimensi yang bersifat photorealistic. Bagaimana memodelkan obyek tiga dimensi untuk menghasilkan hasil photorealistic merupakan masalah yang masih aktif di bidang komputer grafik. Banyak aplikasi lain yang dapat memanfaatkan hasil dari pemodelan tersebut seperti virtual reality, augmented reality dan lain-lain. Pewarnaan voxel merupakan pemodelan obyek tiga dimensi dengan melakukan rekonstruksi warna, bukan rekonstruksi bentuk. Metode ini bekerja dengan cara mendiskritkan obyek menjadi voxel dan

Digital Breast Tomosynthesis guided Near Infrared Spectroscopy: Volumetric estimates of fibroglandular fraction and breast density from tomosynthesis reconstructions.

Science.gov (United States)

Vedantham, Srinivasan; Shi, Linxi; Michaelsen, Kelly E; Krishnaswamy, Venkataramanan; Pogue, Brian W; Poplack, Steven P; Karellas, Andrew; Paulsen, Keith D

A multimodality system combining a clinical prototype digital breast tomosynthesis with its imaging geometry modified to facilitate near-infrared spectroscopic imaging has been developed. The accuracy of parameters recovered from near-infrared spectroscopy is dependent on fibroglandular tissue content. Hence, in this study, volumetric estimates of fibroglandular tissue from tomosynthesis reconstructions were determined. A kernel-based fuzzy c-means algorithm was implemented to segment tomosynthesis reconstructed slices in order to estimate fibroglandular content and to provide anatomic priors for near-infrared spectroscopy. This algorithm was used to determine volumetric breast density (VBD), defined as the ratio of fibroglandular tissue volume to the total breast volume, expressed as percentage, from 62 tomosynthesis reconstructions of 34 study participants. For a subset of study participants who subsequently underwent mammography, VBD from mammography matched for subject, breast laterality and mammographic view was quantified using commercial software and statistically analyzed to determine if it differed from tomosynthesis. Summary statistics of the VBD from all study participants were compared with prior independent studies. The fibroglandular volume from tomosynthesis and mammography were not statistically different ( p =0.211, paired t-test). After accounting for the compressed breast thickness, which were different between tomosynthesis and mammography, the VBD from tomosynthesis was correlated with ( r =0.809, p 0.99, paired t-test), and was linearly related to, the VBD from mammography. Summary statistics of the VBD from tomosynthesis were not statistically different from prior studies using high-resolution dedicated breast computed tomography. The observation of correlation and linear association in VBD between mammography and tomosynthesis suggests that breast density associated risk measures determined for mammography are translatable to tomosynthesis

In situ coating nickel organic complexes on free-standing nickel wire films for volumetric-energy-dense supercapacitors.

Science.gov (United States)

Hong, Min; Xu, Shusheng; Yao, Lu; Zhou, Chao; Hu, Nantao; Yang, Zhi; Hu, Jing; Zhang, Liying; Zhou, Zhihua; Wei, Hao; Zhang, Yafei

2018-07-06

A self-free-standing core-sheath structured hybrid membrane electrodes based on nickel and nickel based metal-organic complexes (Ni@Ni-OC) was designed and constructed for high volumetric supercapacitors. The self-standing Ni@Ni-OC film electrode had a high volumetric specific capacity of 1225.5 C cm -3 at 0.3 A cm -3 and an excellent rate capability. Moreover, when countered with graphene-carbon nanotube (G-CNT) film electrode, the as-assembled Ni@Ni-OC//G-CNT hybrid supercapacitor device delivered an extraordinary volumetric capacitance of 85 F cm -3 at 0.5 A cm -3 and an outstanding energy density of 33.8 at 483 mW cm -3 . Furthermore, the hybrid supercapacitor showed no capacitance loss after 10 000 cycles at 2 A cm -3 , indicating its excellent cycle stability. These fascinating performances can be ascribed to its unique core-sheath structure that high capacity nano-porous nickel based metal-organic complexes (Ni-OC) in situ coated on highly conductive Ni wires. The impressive results presented here may pave the way to construct s self-standing membrane electrode for applications in high volumetric-performance energy storage.

A prototype table-top inverse-geometry volumetric CT system

International Nuclear Information System (INIS)

Schmidt, Taly Gilat; Star-Lack, Josh; Bennett, N. Robert; Mazin, Samuel R.; Solomon, Edward G.; Fahrig, Rebecca; Pelc, Norbert J.

2006-01-01

A table-top volumetric CT system has been implemented that is able to image a 5-cm-thick volume in one circular scan with no cone-beam artifacts. The prototype inverse-geometry CT (IGCT) scanner consists of a large-area, scanned x-ray source and a detector array that is smaller in the transverse direction. The IGCT geometry provides sufficient volumetric sampling because the source and detector have the same axial, or slice direction, extent. This paper describes the implementation of the table-top IGCT scanner, which is based on the NexRay Scanning-Beam Digital X-ray system (NexRay, Inc., Los Gatos, CA) and an investigation of the system performance. The alignment and flat-field calibration procedures are described, along with a summary of the reconstruction algorithm. The resolution and noise performance of the prototype IGCT system are studied through experiments and further supported by analytical predictions and simulations. To study the presence of cone-beam artifacts, a ''Defrise'' phantom was scanned on both the prototype IGCT scanner and a micro CT system with a ±5 deg.cone angle for a 4.5-cm volume thickness. Images of inner ear specimens are presented and compared to those from clinical CT systems. Results showed that the prototype IGCT system has a 0.25-mm isotropic resolution and that noise comparable to that from a clinical scanner with equivalent spatial resolution is achievable. The measured MTF and noise values agreed reasonably well with theoretical predictions and computer simulations. The IGCT system was able to faithfully reconstruct the laminated pattern of the Defrise phantom while the micro CT system suffered severe cone-beam artifacts for the same object. The inner ear acquisition verified that the IGCT system can image a complex anatomical object, and the resulting images exhibited more high-resolution details than the clinical CT acquisition. Overall, the successful implementation of the prototype system supports the IGCT concept for

Cosmological models constructed by van der Waals fluid approximation and volumetric expansion

Science.gov (United States)

Samanta, G. C.; Myrzakulov, R.

The universe modeled with van der Waals fluid approximation, where the van der Waals fluid equation of state contains a single parameter ωv. Analytical solutions to the Einstein’s field equations are obtained by assuming the mean scale factor of the metric follows volumetric exponential and power-law expansions. The model describes a rapid expansion where the acceleration grows in an exponential way and the van der Waals fluid behaves like an inflation for an initial epoch of the universe. Also, the model describes that when time goes away the acceleration is positive, but it decreases to zero and the van der Waals fluid approximation behaves like a present accelerated phase of the universe. Finally, it is observed that the model contains a type-III future singularity for volumetric power-law expansion.

Volumetric three-dimensional display system with rasterization hardware

Science.gov (United States)

Favalora, Gregg E.; Dorval, Rick K.; Hall, Deirdre M.; Giovinco, Michael; Napoli, Joshua

2001-06-01

An 8-color multiplanar volumetric display is being developed by Actuality Systems, Inc. It will be capable of utilizing an image volume greater than 90 million voxels, which we believe is the greatest utilizable voxel set of any volumetric display constructed to date. The display is designed to be used for molecular visualization, mechanical CAD, e-commerce, entertainment, and medical imaging. As such, it contains a new graphics processing architecture, novel high-performance line- drawing algorithms, and an API similar to a current standard. Three-dimensional imagery is created by projecting a series of 2-D bitmaps ('image slices') onto a diffuse screen that rotates at 600 rpm. Persistence of vision fuses the slices into a volume-filling 3-D image. A modified three-panel Texas Instruments projector provides slices at approximately 4 kHz, resulting in 8-color 3-D imagery comprised of roughly 200 radially-disposed slices which are updated at 20 Hz. Each slice has a resolution of 768 by 768 pixels, subtending 10 inches. An unusual off-axis projection scheme incorporating tilted rotating optics is used to maintain good focus across the projection screen. The display electronics includes a custom rasterization architecture which converts the user's 3- D geometry data into image slices, as well as 6 Gbits of DDR SDRAM graphics memory.

Three-dimensional volumetric assessment of response to treatment

International Nuclear Information System (INIS)

Willett, C.G.; Stracher, M.A.; Linggood, R.M.; Leong, J.C.; Skates, S.J.; Miketic, L.M.; Kushner, D.C.; Jacobson, J.O.

1988-01-01

From 1981 to 1986, 12 patients with Stage I and II diffuse large cell lymphoma of the mediastinum were treated with 4 or more cycles of multiagent chemotherapy and for nine patients this was followed by mediastinal irradiation. The response to treatment was assessed by three-dimensional volumetric analysis utilizing thoracic CT scans. The initial mean tumor volume of the five patients relapsing was 540 ml in contrast to an initial mean tumor volume of 360 ml for the seven patients remaining in remission. Of the eight patients in whom mediastinal lymphoma volumes could be assessed 1-2 months after chemotherapy prior to mediastinal irradiation, the three patients who have relapsed had volumes of 292, 92 and 50 ml (mean volume 145 ml) in contrast to five patients who have remained in remission with residual volume abnormalities of 4-87 ml (mean volume 32 ml). Four patients in prolonged remission with CT scans taken one year after treatment have been noted to have mediastinal tumor volumes of 0-28 ml with a mean value of 10 ml. This volumetric technique to assess the extent of mediastinal large cell lymphoma from thoracic CT scans appears to be a useful method to quantitate the amount of disease at presentation as well as objectively monitor response to treatment. 13 refs.; 2 figs.; 1 table

A technical alpha-active aerosol express measurement system for volumetric activity monitoring.; Metodika ehkspressnogo opredeleniya ob`emnoj aktivnosti tekhnogennykh al`fa-aktivnykh aehrozolej.

Energy Technology Data Exchange (ETDEWEB)

Badovskij, V P; Dubar, L V; Tokarevskij, V V; Shevchenko, S V; Shcherbina, V G [Myizhgaluzevij Naukovo-Tekhnyichnij Tsentr ` ` Ukrittya ` ` , Natsyional` na Akademyiya Nauk Ukrayini, Chornobil` (Ukraine)

1994-12-31

A possibility of a volumetric aerosol activity determination at the level of MPCa for {sup 239} Pu with a measurement time less than 60 minutes is discussed. For achieving maximum reduction of the natural background the virtual impactor and alpha-spectroscopy are proposed to be employed. Results of investigation of the virtual impactor parameters at the << Shelter >> and at the laboratory are described.

Synoptic volumetric variations and flushing of the Tampa Bay estuary

Science.gov (United States)

Wilson, M.; Meyers, S. D.; Luther, M. E.

2014-03-01

Two types of analyses are used to investigate the synoptic wind-driven flushing of Tampa Bay in response to the El Niño-Southern Oscillation (ENSO) cycle from 1950 to 2007. Hourly sea level elevations from the St. Petersburg tide gauge, and wind speed and direction from three different sites around Tampa Bay are used for the study. The zonal (u) and meridional (v) wind components are rotated clockwise by 40° to obtain axial and co-axial components according to the layout of the bay. First, we use the subtidal observed water level as a proxy for mean tidal height to estimate the rate of volumetric bay outflow. Second, we use wavelet analysis to bandpass sea level and wind data in the time-frequency domain to isolate the synoptic sea level and surface wind variance. For both analyses the long-term monthly climatology is removed and we focus on the volumetric and wavelet variance anomalies. The overall correlation between the Oceanic Niño Index and volumetric analysis is small due to the seasonal dependence of the ENSO response. The mean monthly climatology between the synoptic wavelet variance of elevation and axial winds are in close agreement. During the winter, El Niño (La Niña) increases (decreases) the synoptic variability, but decreases (increases) it during the summer. The difference in winter El Niño/La Niña wavelet variances is about 20 % of the climatological value, meaning that ENSO can swing the synoptic flushing of the bay by 0.22 bay volumes per month. These changes in circulation associated with synoptic variability have the potential to impact mixing and transport within the bay.

Daily Megavoltage Computed Tomography in Lung Cancer Radiotherapy: Correlation Between Volumetric Changes and Local Outcome

International Nuclear Information System (INIS)

Bral, Samuel; De Ridder, Mark; Duchateau, Michael; Gevaert, Thierry; Engels, Benedikt; Schallier, Denis; Storme, Guy

2011-01-01

Purpose: To assess the predictive or comparative value of volumetric changes, measured on daily megavoltage computed tomography during radiotherapy for lung cancer. Patients and Methods: We included 80 patients with locally advanced non-small-cell lung cancer treated with image-guided intensity-modulated radiotherapy. The radiotherapy was combined with concurrent chemotherapy, combined with induction chemotherapy, or given as primary treatment. Patients entered two parallel studies with moderately hypofractionated radiotherapy. Tumor volume contouring was done on the daily acquired images. A regression coefficient was derived from the volumetric changes on megavoltage computed tomography, and its predictive value was validated. Logarithmic or polynomial fits were applied to the intratreatment changes to compare the different treatment schedules radiobiologically. Results: Regardless of the treatment type, a high regression coefficient during radiotherapy predicted for a significantly prolonged cause-specific local progression free-survival (p = 0.05). Significant differences were found in the response during radiotherapy. The significant difference in volumetric treatment response between radiotherapy with concurrent chemotherapy and radiotherapy plus induction chemotherapy translated to a superior long-term local progression-free survival for concurrent chemotherapy (p = 0.03). An enhancement ratio of 1.3 was measured for the used platinum/taxane doublet in comparison with radiotherapy alone. Conclusion: Contouring on daily megavoltage computed tomography images during radiotherapy enabled us to predict the efficacy of a given treatment. The significant differences in volumetric response between treatment strategies makes it a possible tool for future schedule comparison.

Trapping volumetric measurement by multidetector CT in chronic obstructive pulmonary disease: Effect of CT threshold

Energy Technology Data Exchange (ETDEWEB)

Wang, Xiaohua; Yuan, Huishu [Department of Radiology, Peking University Third Hospital, Beijing 100191 (China); Duan, Jianghui [Medical School, Peking University, Beijing 100191 (China); Du, Yipeng; Shen, Ning; He, Bei [Department of Respiration Internal Medicine, Peking University Third Hospital, Beijing 100191 (China)

2013-08-15

Purpose: The purpose of this study was to evaluate the effect of various computed tomography (CT) thresholds on trapping volumetric measurements by multidetector CT in chronic obstructive pulmonary disease (COPD).Methods: Twenty-three COPD patients were scanned with a 64-slice CT scanner in both the inspiratory and expiratory phase. CT thresholds of −950 Hu in inspiration and −950 to −890 Hu in expiration were used, after which trapping volumetric measurements were made using computer software. Trapping volume percentage (Vtrap%) under the different CT thresholds in the expiratory phase and below −950 Hu in the inspiratory phase was compared and correlated with lung function.Results: Mean Vtrap% was similar under −930 Hu in the expiratory phase and below −950 Hu in the inspiratory phase, being 13.18 ± 9.66 and 13.95 ± 6.72 (both lungs), respectively; this difference was not significant (P= 0.240). Vtrap% under −950 Hu in the inspiratory phase and below the −950 to −890 Hu threshold in the expiratory phase was moderately negatively correlated with the ratio of forced expiratory volume in one second to forced vital capacity and the measured value of forced expiratory volume in one second as a percentage of the predicted value.Conclusions: Trapping volumetric measurement with multidetector CT is a promising method for the quantification of COPD. It is important to know the effect of various CT thresholds on trapping volumetric measurements.

Support for external validity of radiological anatomy tests using volumetric images

NARCIS (Netherlands)

Ravesloot, Cécile J.; van der Gijp, Anouk; van der Schaaf, Marieke F.; Huige, Josephine C B M; Vincken, Koen L.; Mol, Christian P.; Bleys, Ronald L A W; ten Cate, Olle T.; van Schaik, Jan P J

2015-01-01

Rationale and Objectives: Radiology practice has become increasingly based on volumetric images (VIs), but tests in medical education still mainly involve two-dimensional (2D) images. We created a novel, digital, VI test and hypothesized that scores on this test would better reflect radiological

Support for external validity of radiological anatomy tests using volumetric images

NARCIS (Netherlands)

Ravesloot, Cecile J.; van der Gijp, Anouk; van der Schaaf, Marieke F; Huige, Josephine C B M; Vincken, Koen L; Mol, Christian P; Bleys, Ronald L A W; ten Cate, Olle T; van Schaik, JPJ

2015-01-01

RATIONALE AND OBJECTIVES: Radiology practice has become increasingly based on volumetric images (VIs), but tests in medical education still mainly involve two-dimensional (2D) images. We created a novel, digital, VI test and hypothesized that scores on this test would better reflect radiological

A Solar Volumetric Receiver: Influence of Absorbing Cells Configuration on Device Thermal Performance

Science.gov (United States)

Yilbas, B. S.; Shuja, S. Z.

2017-01-01

Thermal performance of a solar volumetric receiver incorporating the different cell geometric configurations is investigated. Triangular, hexagonal, and rectangular absorbing cells are incorporated in the analysis. The fluid volume fraction, which is the ratio of the volume of the working fluid over the total volume of solar volumetric receiver, is introduced to assess the effect of cell size on the heat transfer rates in the receiver. In this case, reducing the fluid volume fraction corresponds to increasing cell size in the receiver. SiC is considered as the cell material, and air is used as the working fluid in the receiver. The Lambert's Beer law is incorporated to account for the solar absorption in the receiver. A finite element method is used to solve the governing equation of flow and heat transfer. It is found that the fluid volume fraction has significant effect on the flow field in the solar volumetric receiver, which also modifies thermal field in the working fluid. The triangular absorbing cell gives rise to improved effectiveness of the receiver and then follows the hexagonal and rectangular cells. The second law efficiency of the receiver remains high when hexagonal cells are used. This occurs for the fluid volume fraction ratio of 0.5.

A new method to determine the number of experimental data using statistical modeling methods

Energy Technology Data Exchange (ETDEWEB)

Jung, Jung-Ho; Kang, Young-Jin; Lim, O-Kaung; Noh, Yoojeong [Pusan National University, Busan (Korea, Republic of)

2017-06-15

For analyzing the statistical performance of physical systems, statistical characteristics of physical parameters such as material properties need to be estimated by collecting experimental data. For accurate statistical modeling, many such experiments may be required, but data are usually quite limited owing to the cost and time constraints of experiments. In this study, a new method for determining a rea- sonable number of experimental data is proposed using an area metric, after obtaining statistical models using the information on the underlying distribution, the Sequential statistical modeling (SSM) approach, and the Kernel density estimation (KDE) approach. The area metric is used as a convergence criterion to determine the necessary and sufficient number of experimental data to be acquired. The pro- posed method is validated in simulations, using different statistical modeling methods, different true models, and different convergence criteria. An example data set with 29 data describing the fatigue strength coefficient of SAE 950X is used for demonstrating the performance of the obtained statistical models that use a pre-determined number of experimental data in predicting the probability of failure for a target fatigue life.

Improved correlation between CT emphysema quantification and pulmonary function test by density correction of volumetric CT data based on air and aortic density

Energy Technology Data Exchange (ETDEWEB)

Kim, Song Soo [Department of Radiology, Chungnam National University Hospital, Chungnam National University School of Medicine (Korea, Republic of); Seo, Joon Beom, E-mail: seojb@amc.seoul.kr [Department of Radiology, University of Ulsan College of Medicine, Asan Medical Center (Korea, Republic of); Kim, Namkug; Chae, Eun Jin [Department of Radiology, University of Ulsan College of Medicine, Asan Medical Center (Korea, Republic of); Lee, Young Kyung [Department of Radiology, Kyung Hee University Hospital at Gangdong (Korea, Republic of); Oh, Yeon Mok; Lee, Sang Do [Division of Pulmonology, Department of Internal Medicine, University of Ulsan College of Medicine, Asan Medical Center (Korea, Republic of)

2014-01-15

Objectives: To determine the improvement of emphysema quantification with density correction and to determine the optimal site to use for air density correction on volumetric computed tomography (CT). Methods: Seventy-eight CT scans of COPD patients (GOLD II–IV, smoking history 39.2 ± 25.3 pack-years) were obtained from several single-vendor 16-MDCT scanners. After density measurement of aorta, tracheal- and external air, volumetric CT density correction was conducted (two reference values: air, −1000 HU/blood, +50 HU). Using in-house software, emphysema index (EI) and mean lung density (MLD) were calculated. Differences in air densities, MLD and EI prior to and after density correction were evaluated (paired t-test). Correlation between those parameters and FEV{sub 1} and FEV{sub 1}/FVC were compared (age- and sex adjusted partial correlation analysis). Results: Measured densities (HU) of tracheal- and external air differed significantly (−990 ± 14, −1016 ± 9, P < 0.001). MLD and EI on original CT data, after density correction using tracheal- and external air also differed significantly (MLD: −874.9 ± 27.6 vs. −882.3 ± 24.9 vs. −860.5 ± 26.6; EI: 16.8 ± 13.4 vs. 21.1 ± 14.5 vs. 9.7 ± 10.5, respectively, P < 0.001). The correlation coefficients between CT quantification indices and FEV{sub 1}, and FEV{sub 1}/FVC increased after density correction. The tracheal air correction showed better results than the external air correction. Conclusion: Density correction of volumetric CT data can improve correlations of emphysema quantification and PFT.

Improved experimental determination of critical-point data for tungsten

International Nuclear Information System (INIS)

Fucke, W.; Seydel, U.

1980-01-01

It is shown that under certain conditions in resistive pulse-heating experiments, refractory liquid metals can be heated up to the limit of thermodynamic stability (spinodal) of the superheated liquid. Here, an explosion-like decomposition takes place which is directly monitored by measurements of expansion, surface radiation, and electric resistivity, thus allowing the determination of the temperature-pressure dependence of the spinodal transition. A comparison of the spinodal equation obtained this way with theoretical models yields the critical temperature Tsub(c), pressure psub(c), and volume vsub(c). A completely experimentally-determined set of the critical parameters for tungsten is presented: Tsub(c) = (13400 +- 1400) K, psub(c) = (3370 +- 850) bar, vsub(c) = (43 +- 4) cm 3 mol -1 . (author)

Determination of Volumetric Losses in Hydrodynamic Pump Using Numerical Modelling

Directory of Open Access Journals (Sweden)

Lukáš ZAVADIL

2012-06-01

Full Text Available This paper deals with the numerical modelling of the flow in the single-stage centrifugal pump. The main objective is to determine leakage losses through annular seals at the suction side of the pump. Leakage through a shaft seal is not included in the simulation. The amount of liquid that circulates from the impeller discharge back to suction of the pump is determined in dependence on the flow rate. Losses in the pump are further discussed as well as the possibility of their prediction.

Systematic Parameterization, Storage, and Representation of Volumetric DICOM Data

OpenAIRE

Fischer, Felix; Selver, M. Alper; Gezer, Sinem; Dicle, O?uz; Hillen, Walter

2015-01-01

Tomographic medical imaging systems produce hundreds to thousands of slices, enabling three-dimensional (3D) analysis. Radiologists process these images through various tools and techniques in order to generate 3D renderings for various applications, such as surgical planning, medical education, and volumetric measurements. To save and store these visualizations, current systems use snapshots or video exporting, which prevents further optimizations and requires the storage of significant addi...

The basics of experimental determination of the Fano factor in intrinsic semiconductors

International Nuclear Information System (INIS)

Samedov, Victor-V.

2013-06-01

Intrinsic semiconductors such as High Purity Germanium Detectors are exceptional X-ray and gamma-ray detectors because of their large sizes and small band gap. They are used for fundamental scientific researches, nuclear material safeguards and security, environmental protection, and human health and safety. The fundamental limit of the energy resolution of a semiconductor detector is determined by variance in the number of electron-hole pairs produced by X-rays in detector volume. The principal characteristic of material for using as semiconductor detector is the Fano factor that determines the fluctuation in the number of electron-hole pairs. Now, all existing methods of experimental determination of the Fano factor in semiconductors are based on the subtraction of electronic noise from the signal variance. In this work, I propose the method of experimental determination of the Fano factor in a planar semiconductor detector based on dependences of the mean amplitude and the energy resolution on the electric field. It was shown that inverse electric field expansion of these dependences allow determining the Fano factor, electron mobility lifetime product, and relative variance of electron lifetime due to inhomogeneous charge transport in semiconductor material. The important advantage of the proposed method is independence on detector electronic noise. (authors)

Microfabricated pseudocapacitors using Ni(OH)2 electrodes exhibit remarkable volumetric capacitance and energy density

KAUST Repository

Kurra, Narendra

2014-09-10

Metal hydroxide based microfabricated pseudocapacitors with impressive volumetric stack capacitance and energy density are demonstrated. A combination of top-down photolithographic process and bottom-up chemical synthesis is employed to fabricate the micro-pseudocapacitors (μ-pseudocapacitors). The resulting Ni(OH)2-based devices show several excellent characteristics including high-rate redox activity up to 500 V s-1 and an areal cell capacitance of 16 mF cm-2 corresponding to a volumetric stack capacitance of 325 F cm-3. This volumetric capacitance is two-fold higher than carbon and metal oxide based μ-supercapacitors with interdigitated electrode architecture. Furthermore, these μ-pseudocapacitors show a maximum energy density of 21 mWh cm-3, which is superior to the Li-based thin film batteries. The heterogeneous growth of Ni(OH)2 over the Ni surface during the chemical bath deposition is found to be the key parameter in the formation of uniform monolithic Ni(OH)2 mesoporous nanosheets with vertical orientation, responsible for the remarkable properties of the fabricated devices. Additionally, functional tandem configurations of the μ-pseudocapacitors are shown to be capable of powering a light-emitting diode.

Empirical Constraints on the Origin of Fast Radio Bursts: Volumetric Rates and Host Galaxy Demographics as a Test of Millisecond Magnetar Connection

Science.gov (United States)

Nicholl, M.; Williams, P. K. G.; Berger, E.; Villar, V. A.; Alexander, K. D.; Eftekhari, T.; Metzger, B. D.

2017-07-01

The localization of the repeating fast radio burst (FRB) 121102 to a low-metallicity dwarf galaxy at z = 0.193, and its association with a luminous quiescent radio source, suggests the possibility that FRBs originate from magnetars, formed by the unusual supernovae that occur in such galaxies. We investigate this possibility via a comparison of magnetar birth rates, the FRB volumetric rate, and host galaxy demographics. We calculate average volumetric rates of possible millisecond magnetar production channels, such as superluminous supernovae (SLSNe), long and short gamma-ray bursts (GRBs), and general magnetar production via core-collapse supernovae (CCSNe). For each channel, we also explore the expected host galaxy demographics using their known properties. We determine for the first time the number density of FRB emitters (the product of their volumetric birth rate and lifetime), {R}{FRB}τ ≈ {10}4 Gpc-3, assuming that FRBs are predominantly emitted from repetitive sources similar to FRB 121102 and adopting a beaming factor of 0.1. By comparing rates, we find that production via rare channels (SLSNe, GRBs) implies a typical FRB lifetime of ˜30-300 years, in good agreement with other lines of argument. The total energy emitted over this time is consistent with the available energy stored in the magnetic field. On the other hand, any relation to magnetars produced via normal CCSNe leads to a very short lifetime of ˜0.5 years, in conflict with both theory and observation. We demonstrate that due to the diverse host galaxy distributions of the different progenitor channels, many possible sources of FRB birth can be ruled out with ≲ 10 host galaxy identifications. Conversely, targeted searches of galaxies that have previously hosted decades-old SLSNe and GRBs may be a fruitful strategy for discovering new FRBs and related quiescent radio sources, and determining the nature of their progenitors.

Robust and conductive two-dimensional metal-organic frameworks with exceptionally high volumetric and areal capacitance

Science.gov (United States)

Feng, Dawei; Lei, Ting; Lukatskaya, Maria R.; Park, Jihye; Huang, Zhehao; Lee, Minah; Shaw, Leo; Chen, Shucheng; Yakovenko, Andrey A.; Kulkarni, Ambarish; Xiao, Jianping; Fredrickson, Kurt; Tok, Jeffrey B.; Zou, Xiaodong; Cui, Yi; Bao, Zhenan

2018-01-01

For miniaturized capacitive energy storage, volumetric and areal capacitances are more important metrics than gravimetric ones because of the constraints imposed by device volume and chip area. Typically used in commercial supercapacitors, porous carbons, although they provide a stable and reliable performance, lack volumetric performance because of their inherently low density and moderate capacitances. Here we report a high-performing electrode based on conductive hexaaminobenzene (HAB)-derived two-dimensional metal-organic frameworks (MOFs). In addition to possessing a high packing density and hierarchical porous structure, these MOFs also exhibit excellent chemical stability in both acidic and basic aqueous solutions, which is in sharp contrast to conventional MOFs. Submillimetre-thick pellets of HAB MOFs showed high volumetric capacitances up to 760 F cm-3 and high areal capacitances over 20 F cm-2. Furthermore, the HAB MOF electrodes exhibited highly reversible redox behaviours and good cycling stability with a capacitance retention of 90% after 12,000 cycles. These promising results demonstrate the potential of using redox-active conductive MOFs in energy-storage applications.

EPA flow reference method testing and analysis: Findings report

International Nuclear Information System (INIS)

1999-06-01

This report describes an experimental program sponsored by the US Environmental Protection Agency (EPA) to evaluate potential improvements to the Agency's current reference method for measuring volumetric flow (Method 2, 40 CFR Part 60, Appendix B). Method 2 (Determination of Stack Gas Velocity and Volumetric Flow Rate (Type S Pitot Tube)) specifies measurements to determine volumetric flow, but does not prescribe specific procedures to account for yaw or pitch angles of flow when the flow in the stack is not axial. Method 2 also allows the use of only two probe types, the Type S and the Prandtl

Volumetric and calorimetric properties of aqueous ionene solutions.

Science.gov (United States)

Lukšič, Miha; Hribar-Lee, Barbara

2017-02-01

The volumetric (partial and apparent molar volumes) and calorimetric properties (apparent heat capacities) of aqueous cationic polyelectrolyte solutions - ionenes - were studied using the oscillating tube densitometer and differential scanning calorimeter. The polyion's charge density and the counterion properties were considered as variables. The special attention was put to evaluate the contribution of electrostatic and hydrophobic effects to the properties studied. The contribution of the CH 2 group of the polyion's backbone to molar volumes and heat capacities was estimated. Synergistic effect between polyion and counterions was found.

Spatio-volumetric hazard estimation in the Auckland volcanic field

Science.gov (United States)

Bebbington, Mark S.

2015-05-01

The idea of a volcanic field `boundary' is prevalent in the literature, but ill-defined at best. We use the elliptically constrained vents in the Auckland Volcanic Field to examine how spatial intensity models can be tested to assess whether they are consistent with such features. A means of modifying the anisotropic Gaussian kernel density estimate to reflect the existence of a `hard' boundary is then suggested, and the result shown to reproduce the observed elliptical distribution. A new idea, that of a spatio-volumetric model, is introduced as being more relevant to hazard in a monogenetic volcanic field than the spatiotemporal hazard model due to the low temporal rates in volcanic fields. Significant dependencies between the locations and erupted volumes of the observed centres are deduced, and expressed in the form of a spatially-varying probability density. In the future, larger volumes are to be expected in the `gaps' between existing centres, with the location of the greatest forecast volume lying in the shipping channel between Rangitoto and Castor Bay. The results argue for tectonic control over location and magmatic control over erupted volume. The spatio-volumetric model is consistent with the hypothesis of a flat elliptical area in the mantle where tensional stresses, related to the local tectonics and geology, allow decompressional melting.

Terrestrial laser scanning and a degenerated cylinder model to determine gross morphological change of cadavers under conditions of natural decomposition.

Science.gov (United States)

Zhang, Xiao; Glennie, Craig L; Bucheli, Sibyl R; Lindgren, Natalie K; Lynne, Aaron M

2014-08-01

Decomposition can be a highly variable process with stages that are difficult to quantify. Using high accuracy terrestrial laser scanning a repeated three-dimensional (3D) documentation of volumetric changes of a human body during early decomposition is recorded. To determine temporal volumetric variations as well as 3D distribution of the changed locations in the body over time, this paper introduces the use of multiple degenerated cylinder models to provide a reasonable approximation of body parts against which 3D change can be measured and visualized. An iterative closest point algorithm is used for 3D registration, and a method for determining volumetric change is presented. Comparison of the laser scanning estimates of volumetric change shows good agreement with repeated in-situ measurements of abdomen and limb circumference that were taken diurnally. The 3D visualizations of volumetric changes demonstrate that bloat is a process with a beginning, middle, and end rather than a state of presence or absence. Additionally, the 3D visualizations show conclusively that cadaver bloat is not isolated to the abdominal cavity, but also occurs in the limbs. Detailed quantification of the bloat stage of decay has the potential to alter how the beginning and end of bloat are determined by researchers and can provide further insight into the effects of the ecosystem on decomposition. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Assessment of Volumetric versus Manual Measurement in Disseminated Testicular Cancer; No Difference in Assessment between Non-Radiologists and Genitourinary Radiologist.

Directory of Open Access Journals (Sweden)

Çiğdem Öztürk

Full Text Available The aim of this study was to assess the feasibility and reproducibility of semi-automatic volumetric measurement of retroperitoneal lymph node metastases in testicular cancer (TC patients treated with chemotherapy versus the standardized manual measurements based on RECIST criteria.21 TC patients with retroperitoneal lymph node metastases of testicular cancer were studied with a CT scan of chest and abdomen before and after cisplatin based chemotherapy. Three readers, a surgical resident, a radiological technician and a radiologist, assessed tumor response independently using computerized volumetric analysis with Vitrea software® and manual measurement according to RECIST criteria (version 1.1. Intra- and inter-rater variability were evaluated with intra class correlations and Bland-Altman analysis.Assessment of intra observer and inter observer variance proved non-significant in both measurement modalities. In particularly all intraclass correlation (ICC values for the volumetric analysis were > .99 per observer and between observers. There was minimal bias in agreement for manual as well as volumetric analysis.In this study volumetric measurement using Vitrea software® appears to be a reliable, reproducible method to measure initial tumor volume of retroperitoneal lymph node metastases of testicular cancer after chemotherapy. Both measurement methods can be performed by experienced non-radiologists as well.

Automatic gallbladder segmentation using combined 2D and 3D shape features to perform volumetric analysis in native and secretin-enhanced MRCP sequences.

Science.gov (United States)

Gloger, Oliver; Bülow, Robin; Tönnies, Klaus; Völzke, Henry

2017-11-24

We aimed to develop the first fully automated 3D gallbladder segmentation approach to perform volumetric analysis in volume data of magnetic resonance (MR) cholangiopancreatography (MRCP) sequences. Volumetric gallbladder analysis is performed for non-contrast-enhanced and secretin-enhanced MRCP sequences. Native and secretin-enhanced MRCP volume data were produced with a 1.5-T MR system. Images of coronal maximum intensity projections (MIP) are used to automatically compute 2D characteristic shape features of the gallbladder in the MIP images. A gallbladder shape space is generated to derive 3D gallbladder shape features, which are then combined with 2D gallbladder shape features in a support vector machine approach to detect gallbladder regions in MRCP volume data. A region-based level set approach is used for fine segmentation. Volumetric analysis is performed for both sequences to calculate gallbladder volume differences between both sequences. The approach presented achieves segmentation results with mean Dice coefficients of 0.917 in non-contrast-enhanced sequences and 0.904 in secretin-enhanced sequences. This is the first approach developed to detect and segment gallbladders in MR-based volume data automatically in both sequences. It can be used to perform gallbladder volume determination in epidemiological studies and to detect abnormal gallbladder volumes or shapes. The positive volume differences between both sequences may indicate the quantity of the pancreatobiliary reflux.

Experimental and analytical determination of stability parameters for a balloon tethered in a wind

Science.gov (United States)

Redd, L. T.; Bennett, R. M.; Bland, S. R.

1973-01-01

Experimental and analytical techniques for determining stability parameters for a balloon tethered in a steady wind are described. These techniques are applied to a particular 7.64-meter-long balloon, and the results are presented. The stability parameters of interest appear as coefficients in linearized stability equations and are derived from the various forces and moments acting on the balloon. In several cases the results from the experimental and analytical techniques are compared and suggestions are given as to which techniques are the most practical means of determining values for the stability parameters.

Study of performance of high speed turning using the volumetric dimension coefficient of resultant cutting force; Estudio del rendimiento del torneado de alta velocidad utilizando el coeficiente de dimension volumetrica de la fuerza de corte resultante

Energy Technology Data Exchange (ETDEWEB)

Hernandez-Gonzalez, L. W.; Perez-Rodriguez, R.; Zambrano-Robledo, P. C.; Siller-Carrillo, H. R.; Toscano-Reyes, H.

2013-07-01

This work deals with the experimental study of the resultant cutting force evolution of two coating carbide and a cermet inserts, during the dry turning of AISI 1045 steel with 400, 500 and 600 m/min cutting speeds. A new criterion for machinability study, the coefficient of volumetric dimension of cutting force, it is introduced. The investigation showed a better performance of cermet for moderate and intermediate cutting speeds, while at high cutting speed and final machining time, the three layers coated carbide achieved the best result. The factorial analysis of variance demonstrated a significant effect of machining time on the coefficient of volumetric dimension of resultant cutting force, while the material insert factor and their interaction, for intermediate cutting speed was just significant. (Author)

Volumetric formulation of lattice Boltzmann models with energy conservation

OpenAIRE

Sbragaglia, M.; Sugiyama, K.

2010-01-01

We analyze a volumetric formulation of lattice Boltzmann for compressible thermal fluid flows. The velocity set is chosen with the desired accuracy, based on the Gauss-Hermite quadrature procedure, and tested against controlled problems in bounded and unbounded fluids. The method allows the simulation of thermohydrodyamical problems without the need to preserve the exact space-filling nature of the velocity set, but still ensuring the exact conservation laws for density, momentum and energy. ...

Experimental determination of conduction and valence bands of semiconductor nanoparticles using Kelvin probe force microscopy

International Nuclear Information System (INIS)

Zhang Wen; Chen Yongsheng

2013-01-01

The ability to determine a semiconductor’s band edge positions is important for the design of new photocatalyst materials. In this paper, we introduced an experimental method based on Kelvin probe force microscopy to determine the conduction and valence band edge energies of semiconductor nanomaterials, which has rarely been demonstrated. We tested the method on six semiconductor nanoparticles (α-Fe 2 O 3 , CeO 2 , Al 2 O 3 , CuO, TiO 2 , and ZnO) with known electronic structures. The experimentally determined band edge positions for α-Fe 2 O 3 , Al 2 O 3 , and CuO well matched the literature values with no statistical difference. Except CeO 2 , all other metal oxides had a consistent upward bias in the experimental measurements of band edge positions because of the shielding effect of the adsorbed surface water layer. This experimental approach may outstand as a unique alternative way of probing the band edge energy positions of semiconductor materials to complement the current computational methods, which often find limitations in new synthetic or complex materials. Ultimately, this work provides scientific foundation for developing experimental tools to probe nanoscale electronic properties of photocatalytic materials, which will drive breakthroughs in the design of novel photocatalytic systems and advance the fundamental understanding of material properties.

A comparative study of volumetric breast density estimation in digital mammography and magnetic resonance imaging: results from a high-risk population

Science.gov (United States)

Kontos, Despina; Xing, Ye; Bakic, Predrag R.; Conant, Emily F.; Maidment, Andrew D. A.

2010-03-01

We performed a study to compare methods for volumetric breast density estimation in digital mammography (DM) and magnetic resonance imaging (MRI) for a high-risk population of women. DM and MRI images of the unaffected breast from 32 women with recently detected abnormalities and/or previously diagnosed breast cancer (age range 31-78 yrs, mean 50.3 yrs) were retrospectively analyzed. DM images were analyzed using QuantraTM (Hologic Inc). The MRI images were analyzed using a fuzzy-C-means segmentation algorithm on the T1 map. Both methods were compared to Cumulus (Univ. Toronto). Volumetric breast density estimates from DM and MRI are highly correlated (r=0.90, pwomen with very low-density breasts (peffects in MRI and differences in the computational aspects of the image analysis methods in MRI and DM. The good correlation between the volumetric and the area-based measures, shown to correlate with breast cancer risk, suggests that both DM and MRI volumetric breast density measures can aid in breast cancer risk assessment. Further work is underway to fully-investigate the association between volumetric breast density measures and breast cancer risk.

Experimental determination of optimal clamping torque for AB-PEM Fuel cell

Directory of Open Access Journals (Sweden)

Noor Ul Hassan

2016-04-01

Full Text Available Polymer electrolyte Membrane (PEM fuel cell is an electrochemical device producing electricity by the reaction of hydrogen and oxygen without combustion. PEM fuel cell stack is provided with an appropriate clamping torque to prevent leakage of reactant gases and to minimize the contact resistance between gas diffusion media (GDL and bipolar plates. GDL porous structure and gas permeability is directly affected by the compaction pressure which, consequently, drastically change the fuel cell performance. Various efforts were made to determine the optimal compaction pressure and pressure distributions through simulations and experimentation. Lower compaction pressure results in increase of contact resistance and also chances of leakage. On the other hand, higher compaction pressure decreases the contact resistance but also narrows down the diffusion path for mass transfer from gas channels to the catalyst layers, consequently, lowering cell performance. The optimal cell performance is related to the gasket thickness and compression pressure on GDL. Every stack has a unique assembly pressure due to differences in fuel cell components material and stack design. Therefore, there is still need to determine the optimal torque value for getting the optimal cell performance. This study has been carried out in continuation of deve­lopment of Air breathing PEM fuel cell for small Unmanned Aerial Vehicle (UAV application. Compaction pressure at minimum contact resistance was determined and clamping torque value was calcu­la­ted accordingly. Single cell performance tests were performed at five different clamping torque values i.e 0.5, 1.0, 1.5, 2.0 and 2.5 N m, for achieving optimal cell per­formance. Clamping pressure distribution tests were also performed at these torque values to verify uniform pressure distribution at optimal torque value. Experimental and theoretical results were compared for making inferences about optimal cell perfor­man­ce. A

QUANTITATIVE ESTIMATION OF VOLUMETRIC ICE CONTENT IN FROZEN GROUND BY DIPOLE ELECTROMAGNETIC PROFILING METHOD

Directory of Open Access Journals (Sweden)

L. G. Neradovskiy

2018-01-01

Full Text Available Volumetric estimation of the ice content in frozen soils is known as one of the main problems in the engineering geocryology and the permafrost geophysics. A new way to use the known method of dipole electromagnetic profiling for the quantitative estimation of the volumetric ice content in frozen soils is discussed. Investigations of foundation of the railroad in Yakutia (i.e. in the permafrost zone were used as an example for this new approach. Unlike the conventional way, in which the permafrost is investigated by its resistivity and constructing of geo-electrical cross-sections, the new approach is aimed at the study of the dynamics of the process of attenuation in the layer of annual heat cycle in the field of high-frequency vertical magnetic dipole. This task is simplified if not all the characteristics of the polarization ellipse are measured but the only one which is the vertical component of the dipole field and can be the most easily measured. Collected data of the measurements were used to analyze the computational errors of the average values of the volumetric ice content from the amplitude attenuation of the vertical component of the dipole field. Note that the volumetric ice content is very important for construction. It is shown that usually the relative error of computation of this characteristic of a frozen soil does not exceed 20% if the works are performed by the above procedure using the key-site methodology. This level of accuracy meets requirements of the design-and-survey works for quick, inexpensive, and environmentally friendly zoning of built-up remote and sparsely populated territories of the Russian permafrost zone according to a category of a degree of the ice content in frozen foundations of engineering constructions.

Imaging-genomics reveals driving pathways of MRI derived volumetric tumor phenotype features in Glioblastoma

International Nuclear Information System (INIS)

Grossmann, Patrick; Gutman, David A.; Dunn, William D. Jr; Holder, Chad A.; Aerts, Hugo J. W. L.

2016-01-01

Glioblastoma (GBM) tumors exhibit strong phenotypic differences that can be quantified using magnetic resonance imaging (MRI), but the underlying biological drivers of these imaging phenotypes remain largely unknown. An Imaging-Genomics analysis was performed to reveal the mechanistic associations between MRI derived quantitative volumetric tumor phenotype features and molecular pathways. One hundred fourty one patients with presurgery MRI and survival data were included in our analysis. Volumetric features were defined, including the necrotic core (NE), contrast-enhancement (CE), abnormal tumor volume assessed by post-contrast T1w (tumor bulk or TB), tumor-associated edema based on T2-FLAIR (ED), and total tumor volume (TV), as well as ratios of these tumor components. Based on gene expression where available (n = 91), pathway associations were assessed using a preranked gene set enrichment analysis. These results were put into context of molecular subtypes in GBM and prognostication. Volumetric features were significantly associated with diverse sets of biological processes (FDR < 0.05). While NE and TB were enriched for immune response pathways and apoptosis, CE was associated with signal transduction and protein folding processes. ED was mainly enriched for homeostasis and cell cycling pathways. ED was also the strongest predictor of molecular GBM subtypes (AUC = 0.61). CE was the strongest predictor of overall survival (C-index = 0.6; Noether test, p = 4x10 −4 ). GBM volumetric features extracted from MRI are significantly enriched for information about the biological state of a tumor that impacts patient outcomes. Clinical decision-support systems could exploit this information to develop personalized treatment strategies on the basis of noninvasive imaging. The online version of this article (doi:10.1186/s12885-016-2659-5) contains supplementary material, which is available to authorized users

Quantifying spatial and temporal trends in beach-dune volumetric changes using spatial statistics

Science.gov (United States)

Eamer, Jordan B. R.; Walker, Ian J.

2013-06-01

Spatial statistics are generally underutilized in coastal geomorphology, despite offering great potential for identifying and quantifying spatial-temporal trends in landscape morphodynamics. In particular, local Moran's Ii provides a statistical framework for detecting clusters of significant change in an attribute (e.g., surface erosion or deposition) and quantifying how this changes over space and time. This study analyzes and interprets spatial-temporal patterns in sediment volume changes in a beach-foredune-transgressive dune complex following removal of invasive marram grass (Ammophila spp.). Results are derived by detecting significant changes in post-removal repeat DEMs derived from topographic surveys and airborne LiDAR. The study site was separated into discrete, linked geomorphic units (beach, foredune, transgressive dune complex) to facilitate sub-landscape scale analysis of volumetric change and sediment budget responses. Difference surfaces derived from a pixel-subtraction algorithm between interval DEMs and the LiDAR baseline DEM were filtered using the local Moran's Ii method and two different spatial weights (1.5 and 5 m) to detect statistically significant change. Moran's Ii results were compared with those derived from a more spatially uniform statistical method that uses a simpler student's t distribution threshold for change detection. Morphodynamic patterns and volumetric estimates were similar between the uniform geostatistical method and Moran's Ii at a spatial weight of 5 m while the smaller spatial weight (1.5 m) consistently indicated volumetric changes of less magnitude. The larger 5 m spatial weight was most representative of broader site morphodynamics and spatial patterns while the smaller spatial weight provided volumetric changes consistent with field observations. All methods showed foredune deflation immediately following removal with increased sediment volumes into the spring via deposition at the crest and on lobes in the lee

Qualitative values of radioactivity, area and volumetric: Application on phantoms (target and background)

Energy Technology Data Exchange (ETDEWEB)

Abdel-Rahman Al-Shakhrah, Issa [Department of Physics, University of Jordan, Queen Rania Street, Amman (Jordan)], E-mail: issashak@yahoo.com

2009-04-15

The visualization of a lesion depends on the contrast between the lesion and surrounding background (T/B; (target/background) ratio). For imaging in vivo not only is the radioactivity in the target organ important, but so too is the ratio of radioactivity in the target versus that in the background. Nearly all studies reported in the literature have dealt with the surface index, as a standard factor to study the relationship between the target (tissue or organ) and the background. It is necessary to know the ratio between the volumetric activity of lesions (targets) and normal tissues (background) instead of knowing the ratio between the area activity, the volume index being a more realistic factor than the area index as the targets (tissues or organs) are real volumes that have surfaces. The intention is that this work should aid in approaching a quantitative relationship and differentiation between different tissues (target/background or abnormal/normal tissues). For the background, square regions of interest (Rios) (11x11 pixels in size) were manually drawn by the observer at locations far from the border of the plastic cylinder (simulated organ), while an isocontour region with 50% threshold was drawn automatically over the cylinder. The total number of counts and pixels in each of these regions was calculated. The relationship between different phantom parameters, cylinder (target) depth, area activity ratio (background/target, A(B/T)) and real volumetric activity ratio (background/target, V(B/T)), was demonstrated. Variations in the area and volumetric activity ratio values with respect to the depth were deduced. To find a realistic value of the ratio, calibration charts have been constructed that relate the area and real volumetric ratios as a function of depth of the tissues and organs. Our experiments show that the cross-sectional area of the cylinder (applying a threshold 50% isocontour) has a weak dependence on the activity concentrations of the

Qualitative values of radioactivity, area and volumetric: Application on phantoms (target and background)

International Nuclear Information System (INIS)

Abdel-Rahman Al-Shakhrah, Issa

2009-01-01

The visualization of a lesion depends on the contrast between the lesion and surrounding background (T/B; (target/background) ratio). For imaging in vivo not only is the radioactivity in the target organ important, but so too is the ratio of radioactivity in the target versus that in the background. Nearly all studies reported in the literature have dealt with the surface index, as a standard factor to study the relationship between the target (tissue or organ) and the background. It is necessary to know the ratio between the volumetric activity of lesions (targets) and normal tissues (background) instead of knowing the ratio between the area activity, the volume index being a more realistic factor than the area index as the targets (tissues or organs) are real volumes that have surfaces. The intention is that this work should aid in approaching a quantitative relationship and differentiation between different tissues (target/background or abnormal/normal tissues). For the background, square regions of interest (Rios) (11x11 pixels in size) were manually drawn by the observer at locations far from the border of the plastic cylinder (simulated organ), while an isocontour region with 50% threshold was drawn automatically over the cylinder. The total number of counts and pixels in each of these regions was calculated. The relationship between different phantom parameters, cylinder (target) depth, area activity ratio (background/target, A(B/T)) and real volumetric activity ratio (background/target, V(B/T)), was demonstrated. Variations in the area and volumetric activity ratio values with respect to the depth were deduced. To find a realistic value of the ratio, calibration charts have been constructed that relate the area and real volumetric ratios as a function of depth of the tissues and organs. Our experiments show that the cross-sectional area of the cylinder (applying a threshold 50% isocontour) has a weak dependence on the activity concentrations of the

Volumetric image-guidance: Does routine usage prompt adaptive re-planning? An institutional review

International Nuclear Information System (INIS)

Tanyi, James A.; Fuss, Martin H.

2008-01-01

Purpose. To investigate how the use of volumetric image-guidance using an on-board cone-beam computed tomography (CBCT) system impacts on the frequency of adaptive re-planning. Material and methods. Treatment courses of 146 patients who have undergone a course of external beam radiation therapy (EBRT) using volumetric CBCT image-guidance were analyzed. Target locations included the brain, head and neck, chest, abdomen, as well as prostate and non-prostate pelvis. The majority of patients (57.5%) were treated with hypo-fractionated treatment regimens (three to 15 fraction courses). The frequency of image-guidance ranged from daily (87.7%) to weekly or twice weekly. The underlying medical necessity for adaptive re-planning as well as frequency and consequences of plan adaptation to dose-volume parameters was assessed. Results. Radiation plans of 34 patients (23.3%) were adapted at least once (up to six time) during their course of EBRT as a result of image-guidance CBCT review. Most common causes for adaptive planning were: tumor change (mostly shrinkage: 10 patients; four patients more than one re-plan), change in abdominal girth (systematic change in hollow organ filling; n=7, two patients more than one re-plan), weight loss (n=5), and systematic target setup deviation from simulation (n=5). Adaptive re-plan was required mostly for conventionally fractionated courses; only 5 patient plans undergoing hypo-fractionated treatment were adjusted. In over 91% of adapted plans, the dose-volume parameters did deviate from the prescribed plan parameters by more than 5% for at least 10% of the target volume, or organs-at-risk in close proximity to the target volume. Discussion. Routine use of volumetric image-guidance has in our practice increased the demand for adaptive re-planning. Volumetric CBCT image-guidance provides sufficient imaging information to reliably predict the need for dose adjustment. In the vast majority of cases evaluated, the initial and adapted dose

Engineering three-dimensionally electrodeposited Si-on-Ni inverse opal structure for high volumetric capacity Li-ion microbattery anode.

Science.gov (United States)

Liu, Hao; Cho, Hyung-Man; Meng, Ying Shirley; Li, Quan

2014-06-25

Aiming at improving the volumetric capacity of nanostructured Li-ion battery anode, an electrodeposited Si-on-Ni inverse opal structure has been proposed in the present work. This type of electrode provides three-dimensional bi-continuous pathways for ion/electron transport and high surface area-to-volume ratios, and thus exhibits lower interfacial resistance, but higher effective Li ions diffusion coefficients, when compared to the Si-on-Ni nanocable array electrode of the same active material mass. As a result, improved volumetric capacities and rate capabilities have been demonstrated in the Si-on-Ni inverse opal anode. We also show that optimization of the volumetric capacities and the rate performance of the inverse opal electrode can be realized by manipulating the pore size of the Ni scaffold and the thickness of the Si deposit.

Thermophysical properties of yacon (Smallanthus sonchifolius: experimental determination and effect of moisture content

Directory of Open Access Journals (Sweden)

Camila Augusto Perussello

2015-01-01

Full Text Available The knowledge about thermophysical properties of foods is especially important in thermal processing, influencing the design, optimization and cost reduction of the process, as well as the quality and safety of the final product. This article deals with the determination of some thermophysical properties of yacon, namely, specific mass, specific heat, thermal conductivity and thermal diffusivity during the osmo-convective drying. Yacon is a root with approximately 90% w.b. of moisture content, whose high concentration of fructooligosacharydes and antioxidants has gained attention in the food research field. Yacon slices were osmotically dehydrated for 2 hours in a sucralose solution and then dried in a convective tray dryer for 2 hours, varying the osmotic solution’s temperature and stirring rate and temperature of the drying air. All thermophysical properties were determined during the drying process at 30-minute intervals. The thermophysical properties were determined not only experimentally but also calculated by models available in literature based on the product’s centesimal composition. A satisfactory agreement between experimental and predicted results was obtained. Further, empirical models obtained by nonlinear regression were successfully fitted to the experimental data, as a function of moisture content, within a 94% - 3% w.b. range.

Superconductivity in volumetric and film ceramics Bi-Sr-Ca-Cu-O

International Nuclear Information System (INIS)

Sukhanov, A.A.; Ozmanyan, Kh.R.; Sandomirskij, B.B.

1988-01-01

A superconducting transition with T c0 =82-95 K and T c (R=0)=82-72 K was observed in volumetric and film Bi(Sr 1-x Ca x ) 2 Cu 3 O y samples obtained by solid-phase reaction. Temperature dependences of resistance critical current and magnetic susceptibility are measured

Experimentally determined profiles of fast wave current drive on DIII-D

International Nuclear Information System (INIS)

Forest, C.B.; Petty, C.C.; Baity, F.W.; Chiu, S.C.; deGrassie, J.S.; Groebner, R.J.; Ikezi, H.; Jaeger, E.F.; Kupfer, K.; Murakami, M.; Pinsker, R.I.; Prater, R.; Rice, B.W.; Wade, M.R.; Whyte, D.G.

1996-01-01

Profiles of non-inductive current driven by fast waves have been determined for reversed-shear DIII-D discharges. Both the current profile and toroidal electric field profile are determined from time sequences of equilibrium reconstructions [C. B. Forest et al., Phys. Rev. Lett. 73, 2224 (1994)]. Using this information, the measured current profile has been separated into inductive and non-inductive portions. By comparing similar discharges with co and counter antenna phasings and similar fast wave power, the portion of the total non-inductive current driven by fast waves was determined. The experimentally determined profiles of FWCD are in general agreement with theoretical predictions. Specifically, 135 kA was driven by 1.4 MW of rf power with a profile peaked inside ρ=2. copyright 1996 American Institute of Physics

Development of a volumetric projection technique for the digital evaluation of field of view.

Science.gov (United States)

Marshall, Russell; Summerskill, Stephen; Cook, Sharon

2013-01-01

Current regulations for field of view requirements in road vehicles are defined by 2D areas projected on the ground plane. This paper discusses the development of a new software-based volumetric field of view projection tool and its implementation within an existing digital human modelling system. In addition, the exploitation of this new tool is highlighted through its use in a UK Department for Transport funded research project exploring the current concerns with driver vision. Focusing specifically on rearwards visibility in small and medium passenger vehicles, the volumetric approach is shown to provide a number of distinct advantages. The ability to explore multiple projections of both direct vision (through windows) and indirect vision (through mirrors) provides a greater understanding of the field of view environment afforded to the driver whilst still maintaining compatibility with the 2D projections of the regulatory standards. Field of view requirements for drivers of road vehicles are defined by simplified 2D areas projected onto the ground plane. However, driver vision is a complex 3D problem. This paper presents the development of a new software-based 3D volumetric projection technique and its implementation in the evaluation of driver vision in small- and medium-sized passenger vehicles.

Experimental determination of size distributions: analyzing proper sample sizes

International Nuclear Information System (INIS)

Buffo, A; Alopaeus, V

2016-01-01

The measurement of various particle size distributions is a crucial aspect for many applications in the process industry. Size distribution is often related to the final product quality, as in crystallization or polymerization. In other cases it is related to the correct evaluation of heat and mass transfer, as well as reaction rates, depending on the interfacial area between the different phases or to the assessment of yield stresses of polycrystalline metals/alloys samples. The experimental determination of such distributions often involves laborious sampling procedures and the statistical significance of the outcome is rarely investigated. In this work, we propose a novel rigorous tool, based on inferential statistics, to determine the number of samples needed to obtain reliable measurements of size distribution, according to specific requirements defined a priori. Such methodology can be adopted regardless of the measurement technique used. (paper)

Fast, Computer Supported Experimental Determination of Absolute Zero Temperature at School

Science.gov (United States)

Bogacz, Bogdan F.; Pedziwiatr, Antoni T.

2014-01-01

A simple and fast experimental method of determining absolute zero temperature is presented. Air gas thermometer coupled with pressure sensor and data acquisition system COACH is applied in a wide range of temperature. By constructing a pressure vs temperature plot for air under constant volume it is possible to obtain--by extrapolation to zero…

Problems of experimental determination of mononuclear hydroxocomplexes stability constants

International Nuclear Information System (INIS)

Davydov, Yu. P.; Davydov, D. Yu.

2003-01-01

In order to determine the stability constants of hydroxocomplexes a methodical approach has been developed that involves the following steps: (1) Determination of pH and concentration intervals in which a metal is present only in a form of mononuclear hydroxocomplex in solution; (2) determination of initial form of hydrated cation and conditions under which it occurs in solution; (3) Determination of the forms of mononuclear hydroxocomplexes and their stability constants by at least two independent methods. This paper illustrates application of the above approach for Fe(III) hydroxocomplex stability constant determination. The hydrolysis with formation of mononuclear species was studied at lower iron concentration since a pH interval is wider in that case (pH 3+ (H 2 O) 6 in the interval of pH 1.0 - 1.5. Further increase of pH (higher than 1.5) leads to hydrolysis of Fe with formation of mononuclear hydroxocomplexes. The results of ion exchange and spectrophotometry experiments showed that in a pH interval 1.5- 3.0 Fe(III) form only one complex Fe(OH)2+. The stability constant of iron first hydroxocomplex has been calculated. Applying the above approach for studying a series of cation we came to a conclusion that nearly in every case only the first hydroxocomplex stability stability constant can be experimentally determined. Only in the case of Pu(IV) it was possible to determine also the second constant. This paper demonstrates also application of the above approach for calculation of the Pu(IV) hydroxocomplexes stability constants. (authors)

Experimental determination of airplane mass and inertial characteristics

Science.gov (United States)

Wolowicz, C. H.; Yancey, R. B.

1974-01-01

Current practices are evaluated for experimentally determining airplane center of gravity, moments of inertia, and products of inertia. The techniques discussed are applicable to bodies other than airplanes. In pitching- and rolling-moment-of-inertia investigations with the airplane mounted on and pivoted about knife edges, the nonlinear spring moments that occur at large amplitudes of oscillation can be eliminated by using the proper spring configuration. The single-point suspension double-pendulum technique for obtaining yawing moments of inertia, products of inertia, and the inclination of the principal axis provides accurate results from yaw-mode oscillation data, provided that the sway-mode effects are minimized by proper suspension rig design. Rocking-mode effects in the data can be isolated.

Comparison of a radiomic biomarker with volumetric analysis for decoding tumour phenotypes of lung adenocarcinoma with different disease-specific survival

International Nuclear Information System (INIS)

Yuan, Mei; Zhang, Yu-Dong; Pu, Xue-Hui; Zhong, Yan; Yu, Tong-Fu; Li, Hai; Wu, Jiang-Fen

2017-01-01

To compare a multi-feature-based radiomic biomarker with volumetric analysis in discriminating lung adenocarcinomas with different disease-specific survival on computed tomography (CT) scans. This retrospective study obtained institutional review board approval and was Health Insurance Portability and Accountability Act (HIPAA) compliant. Pathologically confirmed lung adenocarcinoma (n = 431) manifested as subsolid nodules on CT were identified. Volume and percentage solid volume were measured by using a computer-assisted segmentation method. Radiomic features quantifying intensity, texture and wavelet were extracted from the segmented volume of interest (VOI). Twenty best features were chosen by using the Relief method and subsequently fed to a support vector machine (SVM) for discriminating adenocarcinoma in situ (AIS)/minimally invasive adenocarcinoma (MIA) from invasive adenocarcinoma (IAC). Performance of the radiomic signatures was compared with volumetric analysis via receiver-operating curve (ROC) analysis and logistic regression analysis. The accuracy of proposed radiomic signatures for predicting AIS/MIA from IAC achieved 80.5% with ROC analysis (Az value, 0.829; sensitivity, 72.1%; specificity, 80.9%), which showed significantly higher accuracy than volumetric analysis (69.5%, P = 0.049). Regression analysis showed that radiomic signatures had superior prognostic performance to volumetric analysis, with AIC values of 81.2% versus 70.8%, respectively. The radiomic tumour-phenotypes biomarker exhibited better diagnostic accuracy than traditional volumetric analysis in discriminating lung adenocarcinoma with different disease-specific survival. (orig.)

Comparison of a radiomic biomarker with volumetric analysis for decoding tumour phenotypes of lung adenocarcinoma with different disease-specific survival

Energy Technology Data Exchange (ETDEWEB)

Yuan, Mei; Zhang, Yu-Dong; Pu, Xue-Hui; Zhong, Yan; Yu, Tong-Fu [First Affiliated Hospital of Nanjing Medical University, Department of Radiology, Nanjing, Jiangsu Province (China); Li, Hai [First Affiliated Hospital of Nanjing Medical University, Department of Pathology, Nanjing (China); Wu, Jiang-Fen [GE Healthcare, Shanghai (China)

2017-11-15

To compare a multi-feature-based radiomic biomarker with volumetric analysis in discriminating lung adenocarcinomas with different disease-specific survival on computed tomography (CT) scans. This retrospective study obtained institutional review board approval and was Health Insurance Portability and Accountability Act (HIPAA) compliant. Pathologically confirmed lung adenocarcinoma (n = 431) manifested as subsolid nodules on CT were identified. Volume and percentage solid volume were measured by using a computer-assisted segmentation method. Radiomic features quantifying intensity, texture and wavelet were extracted from the segmented volume of interest (VOI). Twenty best features were chosen by using the Relief method and subsequently fed to a support vector machine (SVM) for discriminating adenocarcinoma in situ (AIS)/minimally invasive adenocarcinoma (MIA) from invasive adenocarcinoma (IAC). Performance of the radiomic signatures was compared with volumetric analysis via receiver-operating curve (ROC) analysis and logistic regression analysis. The accuracy of proposed radiomic signatures for predicting AIS/MIA from IAC achieved 80.5% with ROC analysis (Az value, 0.829; sensitivity, 72.1%; specificity, 80.9%), which showed significantly higher accuracy than volumetric analysis (69.5%, P = 0.049). Regression analysis showed that radiomic signatures had superior prognostic performance to volumetric analysis, with AIC values of 81.2% versus 70.8%, respectively. The radiomic tumour-phenotypes biomarker exhibited better diagnostic accuracy than traditional volumetric analysis in discriminating lung adenocarcinoma with different disease-specific survival. (orig.)

Prognostic value of (18)F-FDG PET/CT volumetric parameters in recurrent epithelial ovarian cancer.

Science.gov (United States)

Mayoral, M; Fernandez-Martinez, A; Vidal, L; Fuster, D; Aya, F; Pavia, J; Pons, F; Lomeña, F; Paredes, P

2016-01-01

Metabolic tumour volume (MTV) and total lesion glycolysis (TLG) from (18)F-FDG PET/CT are emerging prognostic biomarkers in various solid neoplasms. These volumetric parameters and the SUVmax have shown to be useful criteria for disease prognostication in preoperative and post-treatment epithelial ovarian cancer (EOC) patients. The purpose of this study was to evaluate the utility of (18)F-FDG PET/CT measurements to predict survival in patients with recurrent EOC. Twenty-six patients with EOC who underwent a total of 31 (18)F-FDG PET/CT studies for suspected recurrence were retrospectively included. SUVmax and volumetric parameters whole-body MTV (wbMTV) and whole-body TLG (wbTLG) with a threshold of 40% and 50% of the SUVmax were obtained. Correlation between PET parameters and progression-free survival (PFS) and the survival analysis of prognostic factors were calculated. Serous cancer was the most common histological subtype (76.9%). The median PFS was 12.5 months (range 10.7-20.6 months). Volumetric parameters showed moderate inverse correlation with PFS but there was no significant correlation in the case of SUVmax. The correlation was stronger for first recurrences. By Kaplan-Meier analysis and log-rank test, wbMTV 40%, wbMTV 50% and wbTLG 50% correlated with PFS. However, SUVmax and wbTLG 40% were not statistically significant predictors for PFS. Volumetric parameters wbMTV and wbTLG 50% measured by (18)F-FDG PET/CT appear to be useful prognostic predictors of outcome and may provide valuable information to individualize treatment strategies in patients with recurrent EOC. Copyright © 2015 Elsevier España, S.L.U. and SEMNIM. All rights reserved.

Solvent evaporation induced graphene powder with high volumetric capacitance and outstanding rate capability for supercapacitors

Science.gov (United States)

Zhang, Xiaozhe; Raj, Devaraj Vasanth; Zhou, Xufeng; Liu, Zhaoping

2018-04-01

Graphene-based electrode materials for supercapacitors usually suffer from poor volumetric performance due to the low density. The enhancement of volumetric capacitance by densification of graphene materials, however, is usually accompanied by deterioration of rate capability, as the huge contraction of pore size hinders rapid diffusion of electrolytes. Thus, it is important to develop suitable pore size in graphene materials, which can sustain fast ion diffusion and avoid excessive voids to acquire high density simultaneously for supercapacitor applications. Accordingly, we propose a simple solvent evaporation method to control the pore size of graphene powders by adjusting the surface tension of solvents. Ethanol is used instead of water to reduce the shrinkage degree of graphene powder during solvent evaporation process, due to its lower surface tension comparing with water. Followed by the assistance of mechanical compression, graphene powder having high compaction density of 1.30 g cm-3 and a large proportion of mesopores in the pore size range of 2-30 nm is obtained, which delivers high volumetric capacitance of 162 F cm-3 and exhibits outstanding rate performance of 76% capacity retention at a high current density of 100 A g-1 simultaneously.

as-PSOCT: Volumetric microscopic imaging of human brain architecture and connectivity.

Science.gov (United States)

Wang, Hui; Magnain, Caroline; Wang, Ruopeng; Dubb, Jay; Varjabedian, Ani; Tirrell, Lee S; Stevens, Allison; Augustinack, Jean C; Konukoglu, Ender; Aganj, Iman; Frosch, Matthew P; Schmahmann, Jeremy D; Fischl, Bruce; Boas, David A

2018-01-15

Polarization sensitive optical coherence tomography (PSOCT) with serial sectioning has enabled the investigation of 3D structures in mouse and human brain tissue samples. By using intrinsic optical properties of back-scattering and birefringence, PSOCT reliably images cytoarchitecture, myeloarchitecture and fiber orientations. In this study, we developed a fully automatic serial sectioning polarization sensitive optical coherence tomography (as-PSOCT) system to enable volumetric reconstruction of human brain samples with unprecedented sample size and resolution. The 3.5 μm in-plane resolution and 50 μm through-plane voxel size allow inspection of cortical layers that are a single-cell in width, as well as small crossing fibers. We show the abilities of as-PSOCT in quantifying layer thicknesses of the cerebellar cortex and creating microscopic tractography of intricate fiber networks in the subcortical nuclei and internal capsule regions, all based on volumetric reconstructions. as-PSOCT provides a viable tool for studying quantitative cytoarchitecture and myeloarchitecture and mapping connectivity with microscopic resolution in the human brain. Copyright © 2017 Elsevier Inc. All rights reserved.

Experimental Determination of Third Derivative of the Gibbs Free Energy, G II

DEFF Research Database (Denmark)

Koga, Yoshikata; Westh, Peter; Inaba, Akira

2010-01-01

We have been evaluating third derivative quantities of the Gibbs free energy, G, by graphically differentiating the second derivatives that are accessible experimentally, and demonstrated their power in elucidating the mixing schemes in aqueous solutions. Here we determine directly one of the third...

Experimental and Theoretical Determination of Heavy Oil Viscosity Under Reservoir Conditions; ANNUAL

International Nuclear Information System (INIS)

Gabitto, Jorge; Barrufet, Maria

2002-01-01

The main objective of this research was to propose a simple procedure to predict heavy oil viscosity at reservoir conditions as a function of easily determined physical properties. This procedure will avoid costly experimental testing and reduce uncertainty in designing thermal recovery processes

Relating Linear and Volumetric Variables Through Body Scanning to Improve Human Interfaces in Space

Science.gov (United States)

Margerum, Sarah E.; Ferrer, Mike A.; Young, Karen S.; Rajulu, Sudhakar

2010-01-01

Designing space suits and vehicles for the diverse human population present unique challenges for the methods of traditional anthropometry. Space suits are bulky and allow the operator to shift position within the suit and inhibit the ability to identify body landmarks. Limited suit sizing options also cause variability in fit and performance between similarly sized individuals. Space vehicles are restrictive in volume in both the fit and the ability to collect data. NASA's Anthropometric and Biomechanics Facility (ABF) has utilized 3D scanning to shift from traditional linear anthropometry to explore and examine volumetric capabilities to provide anthropometric solutions for design. Overall, the key goals are to improve the human-system performance and develop new processes to aid in the design and evaluation of space systems. Four case studies are presented that illustrate the shift from purely linear analyses to an augmented volumetric toolset to predict and analyze the human within the space suit and vehicle. The first case study involves the calculation of maximal head volume to estimate total free volume in the helmet for proper air exchange. Traditional linear measurements resulted in an inaccurate representation of the head shape, yet limited data exists for the determination of a large head volume. Steps were first taken to identify and classify a maximum head volume and the resulting comparisons to the estimate are presented in this paper. This study illustrates the gap between linear components of anthropometry and the need for overall volume metrics in order to provide solutions. A second case study examines the overlay of the space suit scans and components onto scanned individuals to quantify fit and clearance to aid in sizing the suit to the individual. Restrictions in space suit size availability present unique challenges to optimally fit the individual within a limited sizing range while maintaining performance. Quantification of the clearance and

Real-time volumetric image reconstruction and 3D tumor localization based on a single x-ray projection image for lung cancer radiotherapy.

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Li, Ruijiang; Jia, Xun; Lewis, John H; Gu, Xuejun; Folkerts, Michael; Men, Chunhua; Jiang, Steve B

2010-06-01

To develop an algorithm for real-time volumetric image reconstruction and 3D tumor localization based on a single x-ray projection image for lung cancer radiotherapy. Given a set of volumetric images of a patient at N breathing phases as the training data, deformable image registration was performed between a reference phase and the other N-1 phases, resulting in N-1 deformation vector fields (DVFs). These DVFs can be represented efficiently by a few eigenvectors and coefficients obtained from principal component analysis (PCA). By varying the PCA coefficients, new DVFs can be generated, which, when applied on the reference image, lead to new volumetric images. A volumetric image can then be reconstructed from a single projection image by optimizing the PCA coefficients such that its computed projection matches the measured one. The 3D location of the tumor can be derived by applying the inverted DVF on its position in the reference image. The algorithm was implemented on graphics processing units (GPUs) to achieve real-time efficiency. The training data were generated using a realistic and dynamic mathematical phantom with ten breathing phases. The testing data were 360 cone beam projections corresponding to one gantry rotation, simulated using the same phantom with a 50% increase in breathing amplitude. The average relative image intensity error of the reconstructed volumetric images is 6.9% +/- 2.4%. The average 3D tumor localization error is 0.8 +/- 0.5 mm. On an NVIDIA Tesla C1060 GPU card, the average computation time for reconstructing a volumetric image from each projection is 0.24 s (range: 0.17 and 0.35 s). The authors have shown the feasibility of reconstructing volumetric images and localizing tumor positions in 3D in near real-time from a single x-ray image.

Spirometry and volumetric capnography in lung function assessment of obese and normal-weight individuals without asthma.

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Ferreira, Mariana S; Mendes, Roberto T; Marson, Fernando A L; Zambon, Mariana P; Antonio, Maria A R G M; Paschoal, Ilma A; Toro, Adyléia A D C; Severino, Silvana D; Ribeiro, Maria A G O; Ribeiro, José D

To analyze and compare lung function of obese and healthy, normal-weight children and adolescents, without asthma, through spirometry and volumetric capnography. Cross-sectional study including 77 subjects (38 obese) aged 5-17 years. All subjects underwent spirometry and volumetric capnography. The evaluations were repeated in obese subjects after the use of a bronchodilator. At the spirometry assessment, obese individuals, when compared with the control group, showed lower values of forced expiratory volume in the first second by forced vital capacity (FEV 1 /FVC) and expiratory flows at 75% and between 25 and 75% of the FVC (p11 years (p<0.05). Even without the diagnosis of asthma by clinical criteria and without response to bronchodilator use, obese individuals showed lower FEV 1 /FVC values and forced expiratory flow, indicating the presence of an obstructive process. Volumetric capnography showed that obese individuals had higher alveolar tidal volume, with no alterations in ventilation homogeneity, suggesting flow alterations, without affecting lung volumes. Copyright © 2017 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.

Experimental determination of monoethanolamine protonation constant and its temperature dependency

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Ma’mun Sholeh

2017-01-01

Full Text Available Carbon dioxide as one of the major contributors to the global warming problem is produced in large quantities by many important industries and its emission seems to rise from year to year. Aminebased absorption is one of the methods to capture CO2 from its sources. As a reactive system, mass transfer and chemical reaction take place simultaneously. In a vapor-liquid equilibrium model for the CO2-amine-water system, some parameters such as mass transfer coefficients and chemical equilibrium constants need to be known. However, some parameters could be determined experimentally and the rests could be regressed from the model. The protonation constant (pKa, as one of the model parameters, could then be measured experimentally. The purpose of this study is to measure the pKa of monoethanolamine (MEA at a range of temperatures from 303 to 330K by a potentiometric titration method. The experimental data obtained were in a good agreement with the literature data. The pKa data from this work together with those from the literature were then correlated in an empirical correlation to be used for future research.

Determination, by using GPR, of the volumetric water content in structures, sub-structures, foundations and soil - ongoing activities in Working Project 2.5 of COST Action TU1208

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Tosti, Fabio; Slob, Evert

2015-04-01

This work will endeavour to review the current status of research activities carried out in Working Project 2.5 'Determination, by using GPR, of the volumetric water content in structures, sub-structures, foundations and soil' within the framework of Working Group 2 'GPR surveying of pavements, bridges, tunnels and buildings; underground utility and void sensing' of the COST (European COoperation in Science and Technology) Action TU1208 'Civil Engineering Applications of Ground Penetrating Radar' (www.GPRadar.eu). Overall, the Project includes 55 Participants from over 21 countries representing 33 Institutions. By considering the type of Institution, a percentage of 64% (35 units) comes from the academic world, while Research Centres and Companies include, respectively, the 27% (15 units) and 9% (5 units) of Institutions. Geographically speaking, Europe is the continent most represented with 18 out of 21 countries, followed by Africa (2 countries) and Asia (1 country). In more details and according to the Europe sub-regions classification provided by the United Nations, Southern Europe includes 39% of countries, Western Europe 27%, while Northern and Eastern Europe are equally present with 17% of countries each. Relying on the main purpose of Working Project 2.5, namely, the ground-penetrating radar-based evaluation of volumetric water content in structures, substructures , foundations, and soils, four main issues have been overall addressed over the first two years of activities. The first one, has been related to provide a comprehensive state of the art on the topic, due to the wide-ranging applications covered in the main disciplines of civil engineering, differently demanding. In this regard, two main publications reviewing the state of the art have been produced [1,2]. Secondly, discussions among Working Group Chairs and other Working Project Leaders have been undertaken and encouraged to avoid the risk of overlapping amongst similar topics from other Working

Simulation test of PIUS-type reactor with large scale experimental apparatus

International Nuclear Information System (INIS)

Tamaki, M.; Tsuji, Y.; Ito, T.; Tasaka, K.; Kukita, Yutaka

1995-01-01

A large scale experimental apparatus for simulating the PIUS-type reactor has been constructed keeping the volumetric scaling ratio to the realistic reactor model. Fundamental experiments such as a steady state operation and a pump trip simulation were performed. Experimental results were compared with those obtained by the small scale apparatus in JAERI. We have already reported the effectiveness of the feedback control for the primary loop pump speed (PI control) for the stable operation. In this paper this feedback system is modified and the PID control is introduced. This new system worked well for the operation of the PIUS-type reactor even in a rapid transient condition. (author)

Semiautomatic segmentation of liver metastases on volumetric CT images

International Nuclear Information System (INIS)

Yan, Jiayong; Schwartz, Lawrence H.; Zhao, Binsheng

2015-01-01

Purpose: Accurate segmentation and quantification of liver metastases on CT images are critical to surgery/radiation treatment planning and therapy response assessment. To date, there are no reliable methods to perform such segmentation automatically. In this work, the authors present a method for semiautomatic delineation of liver metastases on contrast-enhanced volumetric CT images. Methods: The first step is to manually place a seed region-of-interest (ROI) in the lesion on an image. This ROI will (1) serve as an internal marker and (2) assist in automatically identifying an external marker. With these two markers, lesion contour on the image can be accurately delineated using traditional watershed transformation. Density information will then be extracted from the segmented 2D lesion and help determine the 3D connected object that is a candidate of the lesion volume. The authors have developed a robust strategy to automatically determine internal and external markers for marker-controlled watershed segmentation. By manually placing a seed region-of-interest in the lesion to be delineated on a reference image, the method can automatically determine dual threshold values to approximately separate the lesion from its surrounding structures and refine the thresholds from the segmented lesion for the accurate segmentation of the lesion volume. This method was applied to 69 liver metastases (1.1–10.3 cm in diameter) from a total of 15 patients. An independent radiologist manually delineated all lesions and the resultant lesion volumes served as the “gold standard” for validation of the method’s accuracy. Results: The algorithm received a median overlap, overestimation ratio, and underestimation ratio of 82.3%, 6.0%, and 11.5%, respectively, and a median average boundary distance of 1.2 mm. Conclusions: Preliminary results have shown that volumes of liver metastases on contrast-enhanced CT images can be accurately estimated by a semiautomatic segmentation

Adsorption indicators in double precipitation volumetric. II. Use of radioactive indicators

International Nuclear Information System (INIS)

Carnicero Tejerina, M. I.

1961-01-01

1 31I-fluorescein and 1 10Ag-silver sulphate have been used in order to check the role of adsorption indicators in the volumetric analysis of double precipitation reactions. It has been shown by using isotopes that adsorption of fluorescein on silver halides depends on the foreign cations present in the solution. (Author) 8 refs

Superconductivity in volumetric and film ceramics Bi-Sr-Ca-Cu-O

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Sukhanov, A A; Ozmanyan, Kh R; Sandomirskij, B B

1988-07-10

A superconducting transition with T/sub c0/=82-95 K and T/sub c/(R=0)=82-72 K was observed in volumetric and film Bi(Sr/sub 1-x/Ca/sub x/)/sub 2/Cu/sub 3/O/sub y/ samples obtained by solid-phase reaction. Temperature dependences of resistance critical current and magnetic susceptibility are measured.

Very high frame rate volumetric integration of depth images on mobile devices.

Science.gov (United States)

Kähler, Olaf; Adrian Prisacariu, Victor; Yuheng Ren, Carl; Sun, Xin; Torr, Philip; Murray, David

2015-11-01

Volumetric methods provide efficient, flexible and simple ways of integrating multiple depth images into a full 3D model. They provide dense and photorealistic 3D reconstructions, and parallelised implementations on GPUs achieve real-time performance on modern graphics hardware. To run such methods on mobile devices, providing users with freedom of movement and instantaneous reconstruction feedback, remains challenging however. In this paper we present a range of modifications to existing volumetric integration methods based on voxel block hashing, considerably improving their performance and making them applicable to tablet computer applications. We present (i) optimisations for the basic data structure, and its allocation and integration; (ii) a highly optimised raycasting pipeline; and (iii) extensions to the camera tracker to incorporate IMU data. In total, our system thus achieves frame rates up 47 Hz on a Nvidia Shield Tablet and 910 Hz on a Nvidia GTX Titan XGPU, or even beyond 1.1 kHz without visualisation.

Efficient Algorithms for Real-Time GPU Volumetric Cloud Rendering with Enhanced Geometry

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Carlos Jiménez de Parga

2018-04-01

Full Text Available This paper presents several new techniques for volumetric cloud rendering using efficient algorithms and data structures based on ray-tracing methods for cumulus generation, achieving an optimum balance between realism and performance. These techniques target applications such as flight simulations, computer games, and educational software, even with conventional graphics hardware. The contours of clouds are defined by implicit mathematical expressions or triangulated structures inside which volumetric rendering is performed. Novel techniques are used to reproduce the asymmetrical nature of clouds and the effects of light-scattering, with low computing costs. The work includes a new method to create randomized fractal clouds using a recursive grammar. The graphical results are comparable to those produced by state-of-the-art, hyper-realistic algorithms. These methods provide real-time performance, and are superior to particle-based systems. These outcomes suggest that our methods offer a good balance between realism and performance, and are suitable for use in the standard graphics industry.

Experimental determination of neutron capture cross sections of fast reactor structure materials integrated in intermediate energy spectra. Vol. 2: description of experimental structure

International Nuclear Information System (INIS)

Tassan, S.

1978-01-01

A selection of technical documents is given concerning the experimental determination of the neutron capture cross-sections of fast reactor structural materials (Fe, Cr, Ni...) integrated over the intermediate energy spectra. The experimental structure project and modifications of the reactor RB2 for this experiment, together with criticality and safety calculations, are presented

MDCT linear and volumetric analysis of adrenal glands: Normative data and multiparametric assessment

International Nuclear Information System (INIS)

Carsin-Vu, Aline; Mule, Sebastien; Janvier, Annaelle; Hoeffel, Christine; Oubaya, Nadia; Delemer, Brigitte; Soyer, Philippe

2016-01-01

To study linear and volumetric adrenal measurements, their reproducibility, and correlations between total adrenal volume (TAV) and adrenal micronodularity, age, gender, body mass index (BMI), visceral (VAAT) and subcutaneous adipose tissue volume (SAAT), presence of diabetes, chronic alcoholic abuse and chronic inflammatory disease (CID). We included 154 patients (M/F, 65/89; mean age, 57 years) undergoing abdominal multidetector row computed tomography (MDCT). Two radiologists prospectively independently performed adrenal linear and volumetric measurements with semi-automatic software. Inter-observer reliability was studied using inter-observer correlation coefficient (ICC). Relationships between TAV and associated factors were studied using bivariate and multivariable analysis. Mean TAV was 8.4 ± 2.7 cm 3 (3.3-18.7 cm 3 ). ICC was excellent for TAV (0.97; 95 % CI: 0.96-0.98) and moderate to good for linear measurements. TAV was significantly greater in men (p < 0.0001), alcoholics (p = 0.04), diabetics (p = 0.0003) and those with micronodular glands (p = 0.001). TAV was lower in CID patients (p = 0.0001). TAV correlated positively with VAAT (r = 0.53, p < 0.0001), BMI (r = 0.42, p < 0.0001), SAAT (r = 0.29, p = 0.0003) and age (r = 0.23, p = 0.005). Multivariable analysis revealed gender, micronodularity, diabetes, age and BMI as independent factors influencing TAV. Adrenal gland MDCT-based volumetric measurements are more reproducible than linear measurements. Gender, micronodularity, age, BMI and diabetes independently influence TAV. (orig.)

Experimental preliminary exploration on determining grease thickness simulated by paraffin in petroleum pipelines

International Nuclear Information System (INIS)

Zhao Nongxiao; Arkin, Abulim; Yang Kunjie; Wang Shiheng; Shi Feiyue

2009-01-01

1.25 MeV γ-ray of 60 Co Compton scattering coefficient in the simple of paraffin,are measured by γ-ray energy spectrum analysis in two determining means. At the same experimental condition, we have used this scattering coefficient to determining grease thickness simulated by paraffin. The result show the average relative difference is about 1.29% for the best group. (authors)

Antioxidant Capacity: Experimental Determination by EPR Spectroscopy and Mathematical Modeling.

Science.gov (United States)

Polak, Justyna; Bartoszek, Mariola; Chorążewski, Mirosław

2015-07-22

A new method of determining antioxidant capacity based on a mathematical model is presented in this paper. The model was fitted to 1000 data points of electron paramagnetic resonance (EPR) spectroscopy measurements of various food product samples such as tea, wine, juice, and herbs with Trolox equivalent antioxidant capacity (TEAC) values from 20 to 2000 μmol TE/100 mL. The proposed mathematical equation allows for a determination of TEAC of food products based on a single EPR spectroscopy measurement. The model was tested on the basis of 80 EPR spectroscopy measurements of herbs, tea, coffee, and juice samples. The proposed model works for both strong and weak antioxidants (TEAC values from 21 to 2347 μmol TE/100 mL). The determination coefficient between TEAC values obtained experimentally and TEAC values calculated with proposed mathematical equation was found to be R(2) = 0.98. Therefore, the proposed new method of TEAC determination based on a mathematical model is a good alternative to the standard EPR method due to its being fast, accurate, inexpensive, and simple to perform.

Parallel imaging: is GRAPPA a useful acquisition tool for MR imaging intended for volumetric brain analysis?

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Frank Anders

2009-08-01

Full Text Available Abstract Background The work presented here investigates parallel imaging applied to T1-weighted high resolution imaging for use in longitudinal volumetric clinical studies involving Alzheimer's disease (AD and Mild Cognitive Impairment (MCI patients. This was in an effort to shorten acquisition times to minimise the risk of motion artefacts caused by patient discomfort and disorientation. The principle question is, "Can parallel imaging be used to acquire images at 1.5 T of sufficient quality to allow volumetric analysis of patient brains?" Methods Optimisation studies were performed on a young healthy volunteer and the selected protocol (including the use of two different parallel imaging acceleration factors was then tested on a cohort of 15 elderly volunteers including MCI and AD patients. In addition to automatic brain segmentation, hippocampus volumes were manually outlined and measured in all patients. The 15 patients were scanned on a second occasion approximately one week later using the same protocol and evaluated in the same manner to test repeatability of measurement using images acquired with the GRAPPA parallel imaging technique applied to the MPRAGE sequence. Results Intraclass correlation tests show that almost perfect agreement between repeated measurements of both segmented brain parenchyma fraction and regional measurement of hippocampi. The protocol is suitable for both global and regional volumetric measurement dementia patients. Conclusion In summary, these results indicate that parallel imaging can be used without detrimental effect to brain tissue segmentation and volumetric measurement and should be considered for both clinical and research studies where longitudinal measurements of brain tissue volumes are of interest.

Theoretical and experimental determination of mechanical properties of superconducting composite wire

International Nuclear Information System (INIS)

Gray, W.H.; Sun, C.T.

1976-07-01

The mechanical properties of a composite superconducting (NbTi/Cu) wire are characterized in terms of the mechanical properties of each constituent material. For a particular composite superconducting wire, five elastic material constants were experimentally determined and theoretically calculated. Since the Poisson's ratios for the fiber and the matrix material were very close, there was essentially no (less than 1 percent) difference among all the theoretical predictions for any individual mechanical constant. Because of the expense and difficulty of producing elastic constant data of 0.1 percent accuracy, and therefore conclusively determining which theory is best, no further experiments were performed

Dosimetric effects of sectional adjustments of collimator angles on volumetric modulated arc therapy for irregularly-shaped targets.

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Beom Seok Ahn

Full Text Available To calculate an optimal collimator angle at each of sectional arcs in a full-arc volumetric modulated arc therapy (VMAT plan and evaluate dosimetric quality of these VMAT plans comparing full-arc VMAT plans with a fixed collimator angle.Seventeen patients who had irregularly-shaped target in abdominal, head and neck, and chest cases were selected retrospectively. To calculate an optimal collimator angle at each of sectional arcs in VMAT, integrated MLC apertures which could cover all shapes of target determined by beam's-eye view (BEV within angular sections were obtained for each VMAT plan. The angular sections were 40°, 60°, 90° and 120°. When the collimator settings were rotated at intervals of 2°, we obtained the optimal collimator angle to minimize area size difference between the integrated MLC aperture and collimator settings with 5 mm-margins to the integrated MLC aperture. The VMAT plans with the optimal collimator angles (Colli-VMAT were generated in the EclipseTM. For comparison purposes, one full-arc VMAT plans with a fixed collimator angles (Std-VMAT were generated. The dose-volumetric parameters and total MUs were evaluated.The mean dose-volumetric parameters for target volume of Colli-VMAT were comparable to Std-VMAT. Colli-VMAT improved sparing of most normal organs but for brain stem, compared to Std-VMAT for all cases. There were decreasing tendencies in mean total MUs with decreasing angular section. The mean total MUs for Colli-VMAT with the angular section of 40° (434 ± 95 MU, 317 ± 81 MU, and 371 ± 43 MU for abdominal, head and neck, and chest cases, respectively were lower than those for Std-VMAT (654 ± 182 MU, 517 ± 116 MU, and 533 ± 25 MU, respectively.For an irregularly-shaped target, Colli-VMAT with the angular section of 40° reduced total MUs and improved sparing of normal organs, compared to Std-VMAT.

Dosimetric analysis of testicular doses in prostate intensity-modulated and volumetric-modulated arc radiation therapy at different energy levels

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Onal, Cem, E-mail: hcemonal@hotmail.com; Arslan, Gungor; Dolek, Yemliha; Efe, Esma

2016-01-01

The aim of this study is to evaluate the incidental testicular doses during prostate radiation therapy with intensity-modulated radiotherapy (IMRT) and volumetric-modulated arc radiotherapy (VMAT) at different energies. Dosimetric data of 15 patients with intermediate-risk prostate cancer who were treated with radiotherapy were analyzed. The prescribed dose was 78 Gy in 39 fractions. Dosimetric analysis compared testicular doses generated by 7-field intensity-modulated radiotherapy and volumetric-modulated arc radiotherapy with a single arc at 6, 10, and 15 MV energy levels. Testicular doses calculated from the treatment planning system and doses measured from the detectors were analyzed. Mean testicular doses from the intensity-modulated radiotherapy and volumetric-modulated arc radiotherapy per fraction calculated in the treatment planning system were 16.3 ± 10.3 cGy vs 21.5 ± 11.2 cGy (p = 0.03) at 6 MV, 13.4 ± 10.4 cGy vs 17.8 ± 10.7 cGy (p = 0.04) at 10 MV, and 10.6 ± 8.5 cGy vs 14.5 ± 8.6 cGy (p = 0.03) at 15 MV, respectively. Mean scattered testicular doses in the phantom measurements were 99.5 ± 17.2 cGy, 118.7 ± 16.4 cGy, and 193.9 ± 14.5 cGy at 6, 10, and 15 MV, respectively, in the intensity-modulated radiotherapy plans. In the volumetric-modulated arc radiotherapy plans, corresponding testicular doses per course were 90.4 ± 16.3 cGy, 103.6 ± 16.4 cGy, and 139.3 ± 14.6 cGy at 6, 10, and 15 MV, respectively. In conclusions, this study was the first to measure the incidental testicular doses by intensity-modulated radiotherapy and volumetric-modulated arc radiotherapy plans at different energy levels during prostate-only irradiation. Higher photon energy and volumetric-modulated arc radiotherapy plans resulted in higher incidental testicular doses compared with lower photon energy and intensity-modulated radiotherapy plans.

Confidence in Assessment of Lumbar Spondylolysis Using Three-Dimensional Volumetric T2-Weighted MRI Compared With Limited Field of View, Decreased-Dose CT.

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Delavan, Joshua Adam; Stence, Nicholas V; Mirsky, David M; Gralla, Jane; Fadell, Michael F

2016-07-01

Limited z-axis-coverage computed tomography (CT) to evaluate for pediatric lumbar spondylolysis, altering the technique such that the dose to the patient is comparable or lower than radiographs, is currently used at our institution. The objective of the study was to determine whether volumetric 3-dimensional fast spin echo magnetic resonance imaging (3D MRI) can provide equal or greater diagnostic accuracy compared with limited CT in the diagnosis of pediatric lumbar spondylolysis without ionizing radiation. Volumetric 3D MRI can provide equal or greater diagnostic accuracy compared with low-dose CT for pediatric lumbar spondylolysis without ionizing radiation. Clinical review. Level 2. Three pediatric neuroradiologists evaluated 2-dimensional (2D) MRI, 2D + 3D MRI, and limited CT examinations in 42 pediatric patients who obtained imaging for low back pain and suspected spondylolysis. As there is no gold standard for the diagnosis of spondylolysis besides surgery, interobserver agreement and degree of confidence were compared to determine which modality is preferable. Decreased-dose CT provided a greater level of agreement than 2D MRI and 2D + 3D MRI. The kappa for rater agreement with 2D MRI, 2D + 3D MRI, and CT was 0.19, 0.32, and 1.0, respectively. All raters agreed in 31%, 40%, and 100% of cases with 2D MRI, 2D + 3D MRI, and CT. Lack of confidence was significantly lower with CT (0%) than with 2D MRI (30%) and 2D + 3D MRI (25%). For diagnosing spondylolysis, radiologist agreement and confidence trended toward improvement with the addition of a volumetric 3D MRI sequence to standard 2D MRI sequences compared with 2D MRI alone; however, agreement and confidence remain significantly greater using decreased-dose CT when compared with either MRI acquisition. Decreased-dose CT of the lumbar spine remains the optimal examination to confirm a high suspicion of spondylolysis, with dose essentially equivalent to radiographs. If clinical symptoms are not classic for

Full-field mapping of internal strain distribution in red sandstone specimen under compression using digital volumetric speckle photography and X-ray computed tomography

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Lingtao Mao

2015-04-01

Full Text Available It is always desirable to know the interior deformation pattern when a rock is subjected to mechanical load. Few experimental techniques exist that can represent full-field three-dimensional (3D strain distribution inside a rock specimen. And yet it is crucial that this information is available for fully understanding the failure mechanism of rocks or other geomaterials. In this study, by using the newly developed digital volumetric speckle photography (DVSP technique in conjunction with X-ray computed tomography (CT and taking advantage of natural 3D speckles formed inside the rock due to material impurities and voids, we can probe the interior of a rock to map its deformation pattern under load and shed light on its failure mechanism. We apply this technique to the analysis of a red sandstone specimen under increasing uniaxial compressive load applied incrementally. The full-field 3D displacement fields are obtained in the specimen as a function of the load, from which both the volumetric and the deviatoric strain fields are calculated. Strain localization zones which lead to the eventual failure of the rock are identified. The results indicate that both shear and tension are contributing factors to the failure mechanism.

VOLUMETRIC LEAK DETECTION IN LARGE UNDERGROUND STORAGE TANKS - VOLUME II: APPENDICES A-E

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The program of experiments conducted at Griffiss Air Force Base was devised to expand the understanding of large underground storage tank behavior as it impacts the performance of volumetric leak detection testing. The report addresses three important questions about testing the ...

Theoretical and experimental determination of K - and L -shell x-ray relaxation parameters in Ni

Science.gov (United States)

Guerra, M.; Sampaio, J. M.; Parente, F.; Indelicato, P.; Hönicke, P.; Müller, M.; Beckhoff, B.; Marques, J. P.; Santos, J. P.

2018-04-01

Fluorescence yields (FY) for the Ni K and L shells were determined by a theoretical and an experimental group within the framework of the International Initiative on X-ray Fundamental Parameters (FPs) collaboration. Coster-Kronig (CK) parameters were also measured for the L shell of Ni. Theoretical calculations of the same parameters were performed using the Dirac-Fock method, including relativistic and QED corrections. The experimental values for the FY and CK were determined at the PTB laboratory in the synchrotron radiation facility BESSY II, Berlin, Germany, and are compared to the corresponding calculated values.

Lung, liver and lymph node metastases in follow-up MSCT. Comprehensive volumetric assessment of lesion size changes

International Nuclear Information System (INIS)

Wulff, A.M.; Fischer, S.; Biederer, J.; Heller, M.; Fabel, M.; Bolte, H.; Freitag-Wolf, S.; Soza, G.; Tietjen, C.

2012-01-01

Purpose: To investigate measurement accuracy in terms of precision and inter-rater variability in the simultaneous volumetric assessment of lung, liver and lymph node metastasis size change over time in comparison to RECIST 1.1. Materials and Methods: Three independent readers evaluated multislice CT data from clinical follow-up studies (chest/abdomen) in 50 patients with metastases. A total of 117 lung, 77 liver and 97 lymph node metastases were assessed manually (RECIST 1.1) and by volumetry with semi-automated software. The quality of segmentation and need for manual adjustments were recorded. Volumes were converted to effective diameters to allow comparison to RECIST. For statistical assessment of precision and interobserver agreement, the Wilcoxon-signed rank test and Bland-Altman plots were utilized. Results: The quality of segmentation after manual correction was acceptable to excellent in 95 % of lesions and manual corrections were applied in 21 - 36 % of all lesions, most predominantly in lymph nodes. Mean precision was 2.6 - 6.3 % (manual) with 0.2 - 1.5 % (effective) relative measurement deviation (p <.001). Inter-reader median variation coefficients ranged from 9.4 - 12.8 % (manual) and 2.9 - 8.2 % (volumetric) for different lesion types (p <.001). The limits of agreement were ± 9.8 to ± 11.2 % for volumetric assessment. Conclusion: Superior precision and inter-rater variability of volumetric over manual measurement of lesion change over time was demonstrated in a whole body setting. (orig.)

Lung, liver and lymph node metastases in follow-up MSCT. Comprehensive volumetric assessment of lesion size changes

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Wulff, A.M.; Fischer, S.; Biederer, J.; Heller, M.; Fabel, M. [Universitaetsklinikum Schleswig-Holstein, Kiel (Germany). Klinik fuer Diagnostische Radiologie; Bolte, H. [Universitaetsklinikum Muenster (Germany). Klinik und Poliklinik fuer Nuklearmedizin; Freitag-Wolf, S. [Universitaetsklinikum Schleswig-Holstein, Kiel (Germany). Inst. fuer Medizinische Informatik und Statistik; Soza, G.; Tietjen, C. [Siemens AG (Germany). Imaging and IT Div. Computed Tomography

2012-09-15

Purpose: To investigate measurement accuracy in terms of precision and inter-rater variability in the simultaneous volumetric assessment of lung, liver and lymph node metastasis size change over time in comparison to RECIST 1.1. Materials and Methods: Three independent readers evaluated multislice CT data from clinical follow-up studies (chest/abdomen) in 50 patients with metastases. A total of 117 lung, 77 liver and 97 lymph node metastases were assessed manually (RECIST 1.1) and by volumetry with semi-automated software. The quality of segmentation and need for manual adjustments were recorded. Volumes were converted to effective diameters to allow comparison to RECIST. For statistical assessment of precision and interobserver agreement, the Wilcoxon-signed rank test and Bland-Altman plots were utilized. Results: The quality of segmentation after manual correction was acceptable to excellent in 95 % of lesions and manual corrections were applied in 21 - 36 % of all lesions, most predominantly in lymph nodes. Mean precision was 2.6 - 6.3 % (manual) with 0.2 - 1.5 % (effective) relative measurement deviation (p <.001). Inter-reader median variation coefficients ranged from 9.4 - 12.8 % (manual) and 2.9 - 8.2 % (volumetric) for different lesion types (p <.001). The limits of agreement were {+-} 9.8 to {+-} 11.2 % for volumetric assessment. Conclusion: Superior precision and inter-rater variability of volumetric over manual measurement of lesion change over time was demonstrated in a whole body setting. (orig.)

Amphiphilic ligand exchange reaction-induced supercapacitor electrodes with high volumetric and scalable areal capacitances

Science.gov (United States)

Nam, Donghyeon; Heo, Yeongbeom; Cheong, Sanghyuk; Ko, Yongmin; Cho, Jinhan

2018-05-01

We introduce high-performance supercapacitor electrodes with ternary components prepared from consecutive amphiphilic ligand-exchange-based layer-by-layer (LbL) assembly among amine-functionalized multi-walled carbon nanotubes (NH2-MWCNTs) in alcohol, oleic acid-stabilized Fe3O4 nanoparticles (OA-Fe3O4 NPs) in toluene, and semiconducting polymers (PEDOT:PSS) in water. The periodic insertion of semiconducting polymers within the (OA-Fe3O4 NP/NH2-MWCNT)n multilayer-coated indium tin oxide (ITO) electrode enhanced the volumetric and areal capacitances up to 408 ± 4 F cm-3 and 8.79 ± 0.06 mF cm-2 at 5 mV s-1, respectively, allowing excellent cycling stability (98.8% of the initial capacitance after 5000 cycles) and good rate capability. These values were higher than those of the OA-Fe3O4 NP/NH2-MWCNT multilayered electrode without semiconducting polymer linkers (volumetric capacitance ∼241 ± 4 F cm-3 and areal capacitance ∼1.95 ± 0.03 mF cm-2) at the same scan rate. Furthermore, when the asymmetric supercapacitor cells (ASCs) were prepared using OA-Fe3O4 NP- and OA-MnO NP-based ternary component electrodes, they displayed high volumetric energy (0.36 mW h cm-3) and power densities (820 mW cm-3).

Fetal brain volumetry through MRI volumetric reconstruction and segmentation

Science.gov (United States)

Estroff, Judy A.; Barnewolt, Carol E.; Connolly, Susan A.; Warfield, Simon K.

2013-01-01

Purpose Fetal MRI volumetry is a useful technique but it is limited by a dependency upon motion-free scans, tedious manual segmentation, and spatial inaccuracy due to thick-slice scans. An image processing pipeline that addresses these limitations was developed and tested. Materials and methods The principal sequences acquired in fetal MRI clinical practice are multiple orthogonal single-shot fast spin echo scans. State-of-the-art image processing techniques were used for inter-slice motion correction and super-resolution reconstruction of high-resolution volumetric images from these scans. The reconstructed volume images were processed with intensity non-uniformity correction and the fetal brain extracted by using supervised automated segmentation. Results Reconstruction, segmentation and volumetry of the fetal brains for a cohort of twenty-five clinically acquired fetal MRI scans was done. Performance metrics for volume reconstruction, segmentation and volumetry were determined by comparing to manual tracings in five randomly chosen cases. Finally, analysis of the fetal brain and parenchymal volumes was performed based on the gestational age of the fetuses. Conclusion The image processing pipeline developed in this study enables volume rendering and accurate fetal brain volumetry by addressing the limitations of current volumetry techniques, which include dependency on motion-free scans, manual segmentation, and inaccurate thick-slice interpolation. PMID:20625848

Uncertainty associated with assessing semen volume: are volumetric and gravimetric methods that different?

Science.gov (United States)

Woodward, Bryan; Gossen, Nicole; Meadows, Jessica; Tomlinson, Mathew

2016-12-01

The World Health Organization laboratory manual for the examination of human semen suggests that an indirect measurement of semen volume by weighing (gravimetric method) is more accurate than a direct measure using a serological pipette. A series of experiments were performed to determine the level of discrepancy between the two methods using pipettes and a balance which had been calibrated to a traceable standard. The median weights of 1.0ml and 5.0ml of semen were 1.03 g (range 1.02-1.05 g) and 5.11 g (range 4.95-5.16 g), respectively, suggesting a density for semen between 1.03g and 1.04 g/ml. When the containers were re-weighed after the removal of 5.0 ml semen using a serological pipette, the mean residual loss was 0.12 ml (120 μl) or 0.12 g (median 100 μl, range 70-300 μl). Direct comparison of the volumetric and gravimetric methods in a total of 40 samples showed a mean difference of 0.25ml (median 0.32 ± 0.67ml) representing an error of 8.5%. Residual semen left in the container by weight was on average 0.11 g (median 0.10 g, range 0.05-0.19 g). Assuming a density of 1 g/ml then the average error between volumetric and gravimetric methods was approximately 8% (p gravimetric measurement of semen volume. Laboratories may therefore prefer to provide in-house quality assurance data in order to be satisfied that 'estimating' semen volume is 'fit for purpose' as opposed to assuming a lower uncertainty associated with the WHO recommended method.

[Benefits of volumetric to facial rejuvenation. Part 1: Fat grafting].

Science.gov (United States)

Bui, P; Lepage, C

2017-10-01

For a number of years, a volumetric approach using autologous fat injection has been implemented to improve cosmetic outcome in face-lift procedures and to achieve lasting rejuvenation. Autologous fat as filling tissue has been used in plastic surgery since the late 19th century, but has only recently been associated to face lift procedures. The interest of the association lies on the one hand in the pathophysiology of facial aging, involving skin sag and loss of volume, and on the other hand in the tissue induction properties of grafted fat, "rejuvenating" the injected area. The strict methodology consisting in harvesting, treating then injecting an autologous fat graft is known as LipoStructure ® or lipofilling. We here describe the technique overall, then region by region. It is now well known and seems simple, effective and reproducible, but is nevertheless delicate. For each individual, it is necessary to restore a harmonious face with well-distributed volumes. By associating volumetric to the face lift procedure, the plastic surgeon plays a new role: instead of being a tailor, cutting away excess skin, he or she becomes a sculptor, remodeling the face to restore the harmony of youth. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Computational assessment of visual search strategies in volumetric medical images.

Science.gov (United States)

Wen, Gezheng; Aizenman, Avigael; Drew, Trafton; Wolfe, Jeremy M; Haygood, Tamara Miner; Markey, Mia K

2016-01-01

When searching through volumetric images [e.g., computed tomography (CT)], radiologists appear to use two different search strategies: "drilling" (restrict eye movements to a small region of the image while quickly scrolling through slices), or "scanning" (search over large areas at a given depth before moving on to the next slice). To computationally identify the type of image information that is used in these two strategies, 23 naïve observers were instructed with either "drilling" or "scanning" when searching for target T's in 20 volumes of faux lung CTs. We computed saliency maps using both classical two-dimensional (2-D) saliency, and a three-dimensional (3-D) dynamic saliency that captures the characteristics of scrolling through slices. Comparing observers' gaze distributions with the saliency maps showed that search strategy alters the type of saliency that attracts fixations. Drillers' fixations aligned better with dynamic saliency and scanners with 2-D saliency. The computed saliency was greater for detected targets than for missed targets. Similar results were observed in data from 19 radiologists who searched five stacks of clinical chest CTs for lung nodules. Dynamic saliency may be superior to the 2-D saliency for detecting targets embedded in volumetric images, and thus "drilling" may be more efficient than "scanning."

Normative biometrics for fetal ocular growth using volumetric MRI reconstruction.

Science.gov (United States)

Velasco-Annis, Clemente; Gholipour, Ali; Afacan, Onur; Prabhu, Sanjay P; Estroff, Judy A; Warfield, Simon K

2015-04-01

To determine normative ranges for fetal ocular biometrics between 19 and 38 weeks gestational age (GA) using volumetric MRI reconstruction. The 3D images of 114 healthy fetuses between 19 and 38 weeks GA were created using super-resolution volume reconstructions from MRI slice acquisitions. These 3D images were semi-automatically segmented to measure fetal orbit volume, binocular distance (BOD), interocular distance (IOD), and ocular diameter (OD). All biometry correlated with GA (Volume, Pearson's correlation coefficient (CC) = 0.9680; BOD, CC = 0.9552; OD, CC = 0.9445; and IOD, CC = 0.8429), and growth curves were plotted against linear and quadratic growth models. Regression analysis showed quadratic models to best fit BOD, IOD, and OD and a linear model to best fit volume. Orbital volume had the greatest correlation with GA, although BOD and OD also showed strong correlation. The normative data found in this study may be helpful for the detection of congenital fetal anomalies with more consistent measurements than are currently available. © 2015 John Wiley & Sons, Ltd. © 2015 John Wiley & Sons, Ltd.

Modelling of volumetric composition and mechanical properties of unidirectional hemp/epoxy composites - Effect of enzymatic fibre treatment

DEFF Research Database (Denmark)

Liu, Ming; Thygesen, Anders; Meyer, Anne S.

2016-01-01

The objective of the present study is to assess the effect of enzymatic fibre treatments on the fibre performance in unidirectional hemp/epoxy composites by modelling the volumetric composition and mechanical properties of the composites. It is shown that the applied models can well predict...... the changes in volumetric composition and mechanical properties of the composites when differently treated hemp fibres are used. The decrease in the fibre correlated porosity factor with the enzymatic fibre treatments shows that the removal of pectin by pectinolytic enzymes results in a better fibre...

3D Volumetric Modeling and Microvascular Reconstruction of Irradiated Lumbosacral Defects After Oncologic Resection

Directory of Open Access Journals (Sweden)

Emilio Garcia-Tutor

2016-12-01

Full Text Available Background: Locoregional flaps are sufficient in most sacral reconstructions. However, large sacral defects due to malignancy necessitate a different reconstructive approach, with local flaps compromised by radiation and regional flaps inadequate for broad surface areas or substantial volume obliteration. In this report, we present our experience using free muscle transfer for volumetric reconstruction in such cases, and demonstrate 3D haptic models of the sacral defect to aid preoperative planning.Methods: Five consecutive patients with irradiated sacral defects secondary to oncologic resections were included, surface area ranging from 143-600cm2. Latissimus dorsi-based free flap sacral reconstruction was performed in each case, between 2005 and 2011. Where the superior gluteal artery was compromised, the subcostal artery was used as a recipient vessel. Microvascular technique, complications and outcomes are reported. The use of volumetric analysis and 3D printing is also demonstrated, with imaging data converted to 3D images suitable for 3D printing with Osirix software (Pixmeo, Geneva, Switzerland. An office-based, desktop 3D printer was used to print 3D models of sacral defects, used to demonstrate surface area and contour and produce a volumetric print of the dead space needed for flap obliteration. Results: The clinical series of latissimus dorsi free flap reconstructions is presented, with successful transfer in all cases, and adequate soft-tissue cover and volume obliteration achieved. The original use of the subcostal artery as a recipient vessel was successfully achieved. All wounds healed uneventfully. 3D printing is also demonstrated as a useful tool for 3D evaluation of volume and dead-space.Conclusion: Free flaps offer unique benefits in sacral reconstruction where local tissue is compromised by irradiation and tumor recurrence, and dead-space requires accurate volumetric reconstruction. We describe for the first time the use of

A projection method for under determined optimal experimental designs

KAUST Repository

Long, Quan

2014-01-09

A new implementation, based on the Laplace approximation, was developed in (Long, Scavino, Tempone, & Wang 2013) to accelerate the estimation of the post–experimental expected information gains in the model parameters and predictive quantities of interest. A closed–form approximation of the inner integral and the order of the corresponding dominant error term were obtained in the cases where the parameters are determined by the experiment. In this work, we extend that method to the general cases where the model parameters could not be determined completely by the data from the proposed experiments. We carry out the Laplace approximations in the directions orthogonal to the null space of the corresponding Jacobian matrix, so that the information gain (Kullback–Leibler divergence) can be reduced to an integration against the marginal density of the transformed parameters which are not determined by the experiments. Furthermore, the expected information gain can be approximated by an integration over the prior, where the integrand is a function of the projected posterior covariance matrix. To deal with the issue of dimensionality in a complex problem, we use Monte Carlo sampling or sparse quadratures for the integration over the prior probability density function, depending on the regularity of the integrand function. We demonstrate the accuracy, efficiency and robustness of the proposed method via several nonlinear under determined numerical examples.

A projection method for under determined optimal experimental designs

KAUST Repository

Long, Quan; Scavino, Marco; Tempone, Raul; Wang, Suojin

2014-01-01

A new implementation, based on the Laplace approximation, was developed in (Long, Scavino, Tempone, & Wang 2013) to accelerate the estimation of the post–experimental expected information gains in the model parameters and predictive quantities of interest. A closed–form approximation of the inner integral and the order of the corresponding dominant error term were obtained in the cases where the parameters are determined by the experiment. In this work, we extend that method to the general cases where the model parameters could not be determined completely by the data from the proposed experiments. We carry out the Laplace approximations in the directions orthogonal to the null space of the corresponding Jacobian matrix, so that the information gain (Kullback–Leibler divergence) can be reduced to an integration against the marginal density of the transformed parameters which are not determined by the experiments. Furthermore, the expected information gain can be approximated by an integration over the prior, where the integrand is a function of the projected posterior covariance matrix. To deal with the issue of dimensionality in a complex problem, we use Monte Carlo sampling or sparse quadratures for the integration over the prior probability density function, depending on the regularity of the integrand function. We demonstrate the accuracy, efficiency and robustness of the proposed method via several nonlinear under determined numerical examples.

Experimental determination of the neutron source for the Argonauta reactor subcritical assembly

Energy Technology Data Exchange (ETDEWEB)

Renke, Carlos A.C.; Furieri, Rosanne C.A.A.; Pereira, Joao C.S.; Voi, Dante L.; Barbosa, Andre L.N., E-mail: renke@ien.gov.b [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

2011-07-01

The utilization of a subcritical assembly for the determination of nuclear parameters in a multiplier medium requires a well defined neutron source to carry out the experiments necessary for the acquisition of the desired data. The Argonauta research reactor installed at the Instituto de Engenharia Nuclear has a subcritical assembly, under development, to be coupled at the upper part of the reactor core that will provide the needed neutrons emerging from its internal thermal column made of graphite. In order to perform neutronic calculations to compare with the experimental results, it is necessary a precise knowledge of the emergent neutron flux that will be used as neutron source in the subcritical assembly. In this work, we present the thermal neutron flux profile determined experimentally via the technique of neutron activation analysis, using dysprosium wires uniformly distributed at the top of the internal thermal neutron column of the Argonauta reactor and later submitted to a detection system using Geiger-Mueller detector. These experimental data were then compared with those obtained through neutronic calculation using HAMMER and CITATION codes in order to validate this calculation system and to define a correct neutron source distribution to be used in the subcritical assembly. This procedure avoids a coupled neutronic calculation of the subcritical assembly and the reactor core. It has also been determined the dimension of the graphite pedestal to be used in the bottom of the subcritical assembly tank in order to smooth the emergent neutron flux at the reactor top. Finally, it is estimated the thermal neutron flux inside the assembly tank when filled with water. (author)

Study of the equation of state and determination of molecular parameters of some fluorinated gases

International Nuclear Information System (INIS)

Morizot, Pierre

1972-01-01

Volumetric and dielectric techniques are used to determine non-ideality and molar polarization of UF 6 , MoF 6 , WF 6 and ClF 3 . Comparisons are made between these dielectric non-ideality parameters and those obtained by MAGNUSON and volumetry method. It is demonstrated that dielectric non-ideality parameters are unsettled by an adsorption phenomena on the electrodes. The volumetric second virial coefficients are interpreted with known transport coefficients to determine molecular parameters of the three hexafluorides. Using viscosity data, the existence of a dimerization in the vapor of ClF 3 was demonstrated. Its effect on the observed second virial coefficient was evaluated. (author) [fr

VOLUMETRIC ERROR COMPENSATION IN FIVE-AXIS CNC MACHINING CENTER THROUGH KINEMATICS MODELING OF GEOMETRIC ERROR

Directory of Open Access Journals (Sweden)

Pooyan Vahidi Pashsaki

2016-06-01

Full Text Available Accuracy of a five-axis CNC machine tool is affected by a vast number of error sources. This paper investigates volumetric error modeling and its compensation to the basis for creation of new tool path for improvement of work pieces accuracy. The volumetric error model of a five-axis machine tool with the configuration RTTTR (tilting head B-axis and rotary table in work piece side A΄ was set up taking into consideration rigid body kinematics and homogeneous transformation matrix, in which 43 error components are included. Volumetric error comprises 43 error components that can separately reduce geometrical and dimensional accuracy of work pieces. The machining accuracy of work piece is guaranteed due to the position of the cutting tool center point (TCP relative to the work piece. The cutting tool is deviated from its ideal position relative to the work piece and machining error is experienced. For compensation process detection of the present tool path and analysis of the RTTTR five-axis CNC machine tools geometrical error, translating current position of component to compensated positions using the Kinematics error model, converting newly created component to new tool paths using the compensation algorithms and finally editing old G-codes using G-code generator algorithm have been employed.

Prediction of breast cancer recurrence using lymph node metabolic and volumetric parameters from {sup 18}F-FDG PET/CT in operable triple-negative breast cancer

Energy Technology Data Exchange (ETDEWEB)

Kim, Yong-il [CHA University, Department of Nuclear Medicine, CHA Bundang Medical Center, Seongnam (Korea, Republic of); Seoul National University Hospital, Department of Nuclear Medicine, Seoul (Korea, Republic of); Kim, Yong Joong [Veterans Health Service Medical Center, Seoul (Korea, Republic of); Paeng, Jin Chul; Cheon, Gi Jeong; Lee, Dong Soo [Seoul National University Hospital, Department of Nuclear Medicine, Seoul (Korea, Republic of); Chung, June-Key [Seoul National University Hospital, Department of Nuclear Medicine, Seoul (Korea, Republic of); Seoul National University, Cancer Research Institute, Seoul (Korea, Republic of); Kang, Keon Wook [Seoul National University Hospital, Department of Nuclear Medicine, Seoul (Korea, Republic of); Seoul National University, Cancer Research Institute, Seoul (Korea, Republic of); Seoul National University College of Medicine, Department of Biomedical Sciences, Seoul (Korea, Republic of); Seoul National University College of Medicine, Department of Nuclear Medicine, Seoul (Korea, Republic of)

2017-10-15

Triple-negative breast cancer has a poor prognosis. We evaluated several metabolic and volumetric parameters from preoperative {sup 18}F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) in the prognosis of triple-negative breast cancer and compared them with current clinicopathologic parameters. A total of 228 patients with triple-negative breast cancer (mean age 47.0 ± 10.8 years, all women) who had undergone preoperative PET/CT were included. The PET/CT metabolic parameters evaluated included maximum, peak, and mean standardized uptake values (SUVmax, SUVpeak, and SUVmean, respectively). The volumetric parameters evaluated included metabolic tumor volume (MTV) and total lesion glycolysis (TLG). Metabolic and volumetric parameters were evaluated separately for tumor (T) and lymph nodes (N). The prognostic value of these parameters was compared with that of clinicopathologic parameters. All lymph node metabolic and volumetric parameters showed significant differences between patients with and without recurrence. However, tumor metabolic and volumetric parameters showed no significant differences. In a univariate survival analysis, all lymph node metabolic and volumetric parameters (SUVmax-N, SUVpeak-N, SUVmean-N, MTV-N, and TLG-N; all P < 0.001), T stage (P = 0.010), N stage (P < 0.001), and TNM stage (P < 0.001) were significant parameters. In a multivariate survival analysis, SUVmax-N (P = 0.005), MTV (P = 0.008), and TLG (P = 0.006) with TNM stage (all P < 0.001) were significant parameters. Lymph node metabolic and volumetric parameters were significant predictors of recurrence in patients with triple-negative breast cancer after surgery. Lymph node metabolic and volumetric parameters were useful parameters for evaluating prognosis in patients with triple-negative breast cancer by {sup 18}F-FDG PET/CT, rather than tumor parameters. (orig.)

Kinetic, volumetric and structural effects induced by liquid Ga penetration into ultrafine grained Al

International Nuclear Information System (INIS)

Naderi, Mehrnoosh; Peterlechner, Martin; Schafler, Erhard; Divinski, Sergiy V.; Wilde, Gerhard

2015-01-01

Kinetic, volumetric and structural effects induced by penetration of liquid Ga in ultrafine grained (UFG) Al produced by severe plastic deformation using high-pressure torsion were studied by isothermal dilatometric measurements, electron microscopy, atomic force microscopy and X-ray diffraction. Severe plastic deformation changed the distribution of impurities and their segregation was revealed by transmission electron microscopy. Two-stage length changes of UFG Al were observed which are explained by counteracting effects of expansion due to grain boundary segregation of Ga and contraction due to precipitation and recrystallization. After applying Ga, the kinetics of the liquid Ga penetration in UFG Al is studied in-situ in the electron microscope by the “first appearance” method and the time scales are in agreement with those inducing the volumetric changes

Determination of the stoichiometric ratio uranium dioxide samples

International Nuclear Information System (INIS)

Moura, Sergio Carvalho

1999-01-01

The determination of the O/U stoichiometric ratio in uranium dioxide is an important parameter in order to qualify nuclear fuels. The excess oxygen in the crystallographic structure can cause changes in the physico-chemical properties of this compound such as variation of the thermal conductivity alterations, fuel plasticity and others, affecting the efficiency of this material when it is utilized as nuclear fuel in the reactor core. The purpose of this work is to evaluate methods for the determination of uranium oxide samples from two different production processes, using gravimetric, voltammetric and X-ray diffraction techniques. After the evaluation of these techniques, the main aspect of this work is to define a reliable methodology in order to characterize the behavior of uranium oxide. The methodology used in this work consisted of two different steps: utilization of gravimetric and volumetric methods in order to determine the ratio in uranium dioxide samples; utilization of X-ray diffraction technique in order to determine the lattice parameters using patterns and application of the Rietveld method during refining of the structural data. As a result of the experimental part of this work it was found that the X-ray diffraction analysis performs better and detects the presence of more phases than gravimetric and voltammetric techniques, not sensitive enough in this detection. (author)

Towards ultrahigh volumetric capacitance: graphene derived highly dense but porous carbons for supercapacitors

Science.gov (United States)

Tao, Ying; Xie, Xiaoying; Lv, Wei; Tang, Dai-Ming; Kong, Debin; Huang, Zhenghong; Nishihara, Hirotomo; Ishii, Takafumi; Li, Baohua; Golberg, Dmitri; Kang, Feiyu; Kyotani, Takashi; Yang, Quan-Hong

2013-10-01

A small volumetric capacitance resulting from a low packing density is one of the major limitations for novel nanocarbons finding real applications in commercial electrochemical energy storage devices. Here we report a carbon with a density of 1.58 g cm-3, 70% of the density of graphite, constructed of compactly interlinked graphene nanosheets, which is produced by an evaporation-induced drying of a graphene hydrogel. Such a carbon balances two seemingly incompatible characteristics: a porous microstructure and a high density, and therefore has a volumetric capacitance for electrochemical capacitors (ECs) up to 376 F cm-3, which is the highest value so far reported for carbon materials in an aqueous electrolyte. More promising, the carbon is conductive and moldable, and thus could be used directly as a well-shaped electrode sheet for the assembly of a supercapacitor device free of any additives, resulting in device-level high energy density ECs.

Nanocellulose coupled flexible polypyrrole@graphene oxide composite paper electrodes with high volumetric capacitance

Science.gov (United States)

Wang, Zhaohui; Tammela, Petter; Strømme, Maria; Nyholm, Leif

2015-02-01

A robust and compact freestanding conducting polymer-based electrode material based on nanocellulose coupled polypyrrole@graphene oxide paper is straightforwardly prepared via in situ polymerization for use in high-performance paper-based charge storage devices, exhibiting stable cycling over 16 000 cycles at 5 A g-1 as well as the largest specific volumetric capacitance (198 F cm-3) so far reported for flexible polymer-based electrodes.A robust and compact freestanding conducting polymer-based electrode material based on nanocellulose coupled polypyrrole@graphene oxide paper is straightforwardly prepared via in situ polymerization for use in high-performance paper-based charge storage devices, exhibiting stable cycling over 16 000 cycles at 5 A g-1 as well as the largest specific volumetric capacitance (198 F cm-3) so far reported for flexible polymer-based electrodes. Electronic supplementary information (ESI) available. See DOI: 10.1039/c4nr07251k

Numerical evaluation of an innovative cup layout for open volumetric solar air receivers

Science.gov (United States)

Cagnoli, Mattia; Savoldi, Laura; Zanino, Roberto; Zaversky, Fritz

2016-05-01

This paper proposes an innovative volumetric solar absorber design to be used in high-temperature air receivers of solar power tower plants. The innovative absorber, a so-called CPC-stacked-plate configuration, applies the well-known principle of a compound parabolic concentrator (CPC) for the first time in a volumetric solar receiver, heating air to high temperatures. The proposed absorber configuration is analyzed numerically, applying first the open-source ray-tracing software Tonatiuh in order to obtain the solar flux distribution on the absorber's surfaces. Next, a Computational Fluid Dynamic (CFD) analysis of a representative single channel of the innovative receiver is performed, using the commercial CFD software ANSYS Fluent. The solution of the conjugate heat transfer problem shows that the behavior of the new absorber concept is promising, however further optimization of the geometry will be necessary in order to exceed the performance of the classical absorber designs.

Accuracy and Reliability of Cone-Beam Computed Tomography for Linear and Volumetric Mandibular Condyle Measurements. A Human Cadaver Study.

Science.gov (United States)

García-Sanz, Verónica; Bellot-Arcís, Carlos; Hernández, Virginia; Serrano-Sánchez, Pedro; Guarinos, Juan; Paredes-Gallardo, Vanessa

2017-09-20

The accuracy of Cone-Beam Computed Tomography (CBCT) on linear and volumetric measurements on condyles has only been assessed on dry skulls. The aim of this study was to evaluate the reliability and accuracy of linear and volumetric measurements of mandibular condyles in the presence of soft tissues using CBCT. Six embalmed cadaver heads were used. CBCT scans were taken, followed by the extraction of the condyles. The water displacement technique was used to calculate the volumes of the condyles and three linear measurements were made using a digital caliper, these measurements serving as the gold standard. Surface models of the condyles were obtained using a 3D scanner, and superimposed onto the CBCT images. Condyles were isolated on the CBCT render volume using the surface models as reference and volumes were measured. Linear measurements were made on CBCT slices. The CBCT method was found to be reliable for both volumetric and linear measurements (CV  0.90). Highly accurate values were obtained for the three linear measurements and volume. CBCT is a reliable and accurate method for taking volumetric and linear measurements on mandibular condyles in the presence of soft tissue, and so a valid tool for clinical diagnosis.

Osmotic coefficients of alcoholic mixtures containing BMpyrDCA: Experimental determination and correlation

International Nuclear Information System (INIS)

Calvar, N.; Domínguez, Á.; Macedo, E.A.

2014-01-01

Graphical abstract: - Highlights: • Osmotic coefficients of alcohols with BMpyrDCA ionic liquid are determined. • Experimental data were correlated with Extended Pitzer model of Archer and MNRTL. • Mean molal activity coefficients and excess Gibbs free energies were calculated. • The results have been interpreted in terms of interactions. - Abstract: The vapour pressure osmometry technique (VPO) has been used to obtain the osmotic coefficients of the binary mixtures of the primary and secondary alcohols 1-propanol, 2-propanol, 1-butanol, 2-butanol and 1-pentanol with the ionic liquid 1-butyl-1-methylpyrrolidinium dicyanamide, BMpyrDCA. From these coefficients, the corresponding activity coefficients and vapour pressures of the mixtures have been also determined. The results have been discussed in terms of solute–solvent and ion–ion interactions and have been compared with those taken from literature in order to analyse the influence of the anion or cation constituting the ionic liquid. For the treatment of the experimental data, the Extended Pitzer model of Archer and the MNRTL model have been applied, obtaining standard deviations from the experimental osmotic coefficients lower than 0.015 and 0.065, respectively. From the parameters obtained with the Extended Pitzer model or Archer, the mean molal activity coefficients and the excess Gibbs free energy for the studied mixtures have been calculated

Multicenter assessment of the reproducibility of volumetric radiofrequency-based intravascular ultrasound measurements in coronary lesions that were consecutively stented

DEFF Research Database (Denmark)

Huisman, Jennifer; Egede, Rasmus; Rdzanek, Adam

2012-01-01

To assess in a multicenter design the between-center reproducibility of volumetric virtual histology intravascular ultrasound (VH-IVUS) measurements with a semi-automated, computer-assisted contour detection system in coronary lesions that were consecutively stented. To evaluate the reproducibility...... of volumetric VH-IVUS measurements, experienced analysts of 4 European IVUS centers performed independent analyses (in total 8,052 cross-sectional analyses) to obtain volumetric data of 40 coronary segments (length 20.0 ± 0.3 mm) from target lesions prior to percutaneous intervention that were performed...... in the setting of stable (65%) or unstable angina pectoris (35%). Geometric and compositional VH-IVUS measurements were highly correlated for the different comparisons. Overall intraclass correlation for vessel, lumen, plaque volume and plaque burden was 0.99, 0.92, 0.96, and 0.83, respectively; for fibrous...

Volumetric Visualization of Human Skin

Science.gov (United States)

Kawai, Toshiyuki; Kurioka, Yoshihiro

We propose a modeling and rendering technique of human skin, which can provide realistic color, gloss and translucency for various applications in computer graphics. Our method is based on volumetric representation of the structure inside of the skin. Our model consists of the stratum corneum and three layers of pigments. The stratum corneum has also layered structure in which the incident light is reflected, refracted and diffused. Each layer of pigment has carotene, melanin or hemoglobin. The density distributions of pigments which define the color of each layer can be supplied as one of the voxel values. Surface normals of upper-side voxels are fluctuated to produce bumps and lines on the skin. We apply ray tracing approach to this model to obtain the rendered image. Multiple scattering in the stratum corneum, reflective and absorptive spectrum of pigments are considered. We also consider Fresnel term to calculate the specular component for glossy surface of skin. Some examples of rendered images are shown, which can successfully visualize a human skin.

Volumetric 3-component velocimetry measurements of the flow field on the rear window of a generic car model

Directory of Open Access Journals (Sweden)

Tounsi Nabil

2012-01-01

Full Text Available Volumetric 3-component Velocimetry measurements are carried out in the flow field around the rear window of a generic car model, the so-called Ahmed body. This particular flow field is known to be highly unsteady, three dimensional and characterized by strong vortices. The volumetric velocity measurements from the present experiments provide the most comprehensive data for this flow field to date. The present study focuses on the wake flow modifications which result from using a simple flow control device, such as the one recently employed by Fourrié et al. [1]. The mean data clearly show the structure of this complex flow and confirm the drag reduction mechanism suggested by Fourrié et al. The results show that strengthening the separated flow leads to weakening the longitudinal vortices and vice versa. The present paper shows that the Volumetric 3-component Velocimetry technique is a powerful tool used for a better understanding of a threedimensional unsteady complex flow such that developing around a bluffbody.

Spatial distribution of bacterial communities on volumetric and planar anodes in single-chamber air-cathode microbial fuel cells

KAUST Repository

Vargas, Ignacio T.

2013-05-29

Pyrosequencing was used to characterize bacterial communities in air-cathode microbial fuel cells across a volumetric (graphite fiber brush) and a planar (carbon cloth) anode, where different physical and chemical gradients would be expected associated with the distance between anode location and the air cathode. As expected, the stable operational voltage and the coulombic efficiency (CE) were higher for the volumetric anode than the planar anode (0.57V and CE=22% vs. 0.51V and CE=12%). The genus Geobacter was the only known exoelectrogen among the observed dominant groups, comprising 57±4% of recovered sequences for the brush and 27±5% for the carbon-cloth anode. While the bacterial communities differed between the two anode materials, results showed that Geobacter spp. and other dominant bacterial groups were homogenously distributed across both planar and volumetric anodes. This lends support to previous community analysis interpretations based on a single biofilm sampling location in these systems. © 2013 Wiley Periodicals, Inc.

Experimental determination of soot refractive index in the infrared

International Nuclear Information System (INIS)

Ouf, F.X.; Vendel, J.; Ouf, F.X.; Coppalle, A.; Weil, M.E.; Yon, J.

2007-01-01

The study of physical properties of soot particles produced during combustion is a complex subject but of a great interest within the framework of the study of the safety of an installation, with respect to the fire hazard. These characteristics are, in this case, particularly useful in order to predict the behaviour of containment barriers in situation of fire, but also in order to estimate the contribution of these particles to radiative transfers. The aim of this study is to determine the radiative properties of soot particles produced during combustion. A specific device, which establishes extinction and vertical-vertical scattering coefficients, has been developed and has allowed to determine the refractive index of soot particles in the infrared. This determination also needed the establishment of size distribution and morphological properties of soot aggregates. We present in this document the experimental device developed, and the validation of this device on latex spheres which optical properties are well known. First results of extinction coefficients will be presented and will underline the similar optical behaviour of different soot aggregates. Values of refractive index will be detailed and discussed, and a direct application of these values will be carried out in order to determine the soot volume fraction. A comparison with reference method will underline the efficiency of our method. We will conclude on the validity of the information brought by this device and on the prospects of this study. A discussion is included, on the utility of mean values of refractive index and on the determination of total emissivity of soot particles. (authors)

Real-time volumetric deformable models for surgery simulation using finite elements and condensation

DEFF Research Database (Denmark)

Bro-Nielsen, Morten; Cotin, S.

1996-01-01

This paper discusses the application of SD solid volumetric Finite Element models to surgery simulation. In particular it introduces three new ideas for solving the problem of achieving real-time performance for these models. The simulation system we have developed is described and we demonstrate...

Biventricular MR volumetric analysis and MR flow quantification in the ascending aorta and pulmonary trunk for quantification of valvular regurgitation

International Nuclear Information System (INIS)

Rominger, M.B.

2004-01-01

Purpose: To test the value of biventricular volumetric analysis and the combination of biventricular volumetric analysis with flow quantification in the ascending aorta (Ao) and pulmonary trunk (Pu) for quantification of regurgitation volume and cardiac function in valvular regurgitation (VR) according to location and presence of single or multivalvular disease. Materials and Methods: In 106 patients, the stroke volumes were assessed by measuring the biventricular volumes and the forward-stroke volumes in the great and small circulation by measuring the flow in the Ao and Pu. Valve regurgitation volumes and quotients were calculated for single and multivalvular disease and correlated with semiquantitative 2D-echocardiography (grade I-IV). For the assessment of the cardiac function in VR, the volumetric parameters of ejection fraction and end-diastolic (EDV) and end-systolic (ESV) volumes were determined. Results: The detection rate was 49% for left ventricular (LV) VR and 42% for right ventricular (RV) VR. Low LV VR and RV VR usually could not be detected quantitatively, with the detection rate improving with echocardiographically higher insufficiency grades. Quantitative MRI could detect a higher grade solitary aortic valve insufficiency (≥2) in 11 of 12 patients and higher grade mitral valve insufficiency in 4 of 10 patients. A significant increase in RV and LV ventricular EDV and ESV was seen more often with increased MR regurgitation volumes. Aortic stenosis did not interfere with flow measurements in the Ao. Conclusions: Biventricular volumetry combined with flow measurements in Ao and Pu is a robust, applicable and simple method to assess higher grade regurgitation volumes and the cardiac function in single and multivalvular regurgitation at different locations. It is an important application for the diagnosis of VR by MRI [de

Experimental determination of the electron-avalanche and the electron-ion recombination coefficient

NARCIS (Netherlands)

Ernst, G.J.; Boer, A.G.

1980-01-01

The electron-ion recombination coefficient γ and the avalanche coefficient δ = (α − a) · vd, where α and a are the ionizat ion and attachment coefficients respectively and vd the drift velocity of the electrons, have been experimentally determined in a self-sustained CO2-laser system (1:1:3 mixture)

Coarse Grid Modeling of Turbine Film Cooling Flows Using Volumetric Source Terms

Science.gov (United States)

Heidmann, James D.; Hunter, Scott D.

2001-01-01

The recent trend in numerical modeling of turbine film cooling flows has been toward higher fidelity grids and more complex geometries. This trend has been enabled by the rapid increase in computing power available to researchers. However, the turbine design community requires fast turnaround time in its design computations, rendering these comprehensive simulations ineffective in the design cycle. The present study describes a methodology for implementing a volumetric source term distribution in a coarse grid calculation that can model the small-scale and three-dimensional effects present in turbine film cooling flows. This model could be implemented in turbine design codes or in multistage turbomachinery codes such as APNASA, where the computational grid size may be larger than the film hole size. Detailed computations of a single row of 35 deg round holes on a flat plate have been obtained for blowing ratios of 0.5, 0.8, and 1.0, and density ratios of 1.0 and 2.0 using a multiblock grid system to resolve the flows on both sides of the plate as well as inside the hole itself. These detailed flow fields were spatially averaged to generate a field of volumetric source terms for each conservative flow variable. Solutions were also obtained using three coarse grids having streamwise and spanwise grid spacings of 3d, 1d, and d/3. These coarse grid solutions used the integrated hole exit mass, momentum, energy, and turbulence quantities from the detailed solutions as volumetric source terms. It is shown that a uniform source term addition over a distance from the wall on the order of the hole diameter is able to predict adiabatic film effectiveness better than a near-wall source term model, while strictly enforcing correct values of integrated boundary layer quantities.

Programmable segmented volumetric modulated arc therapy for respiratory coordination in pancreatic cancer

International Nuclear Information System (INIS)

Wu, Jian-Kuen; Wu, Chien-Jang; Cheng, Jason Chia-Hsien

2012-01-01

We programmably divided long-arc volumetric modulated arc therapy (VMAT) into split short arcs, each taking less than 30 s for respiratory coordination. The VMAT plans of five pancreatic cancer patients were modified; the short-arc plans had negligible dose differences and satisfied the 3%/3-mm gamma index on a MapCHECK-2 device.

Eye-tracking of nodule detection in lung CT volumetric data

Energy Technology Data Exchange (ETDEWEB)

Diaz, Ivan; Verdun, Francis R.; Bochud, François O., E-mail: francois.bochud@chuv.ch [Institute of Radiation Physics, Lausanne University Hospital, Lausanne 1004 (Switzerland); Schmidt, Sabine [Department of Radiology, Lausanne University Hospital, Lausanne 1004 (Switzerland)

2015-06-15

Purpose: Signal detection on 3D medical images depends on many factors, such as foveal and peripheral vision, the type of signal, and background complexity, and the speed at which the frames are displayed. In this paper, the authors focus on the speed with which radiologists and naïve observers search through medical images. Prior to the study, the authors asked the radiologists to estimate the speed at which they scrolled through CT sets. They gave a subjective estimate of 5 frames per second (fps). The aim of this paper is to measure and analyze the speed with which humans scroll through image stacks, showing a method to visually display the behavior of observers as the search is made as well as measuring the accuracy of the decisions. This information will be useful in the development of model observers, mathematical algorithms that can be used to evaluate diagnostic imaging systems. Methods: The authors performed a series of 3D 4-alternative forced-choice lung nodule detection tasks on volumetric stacks of chest CT images iteratively reconstructed in lung algorithm. The strategy used by three radiologists and three naïve observers was assessed using an eye-tracker in order to establish where their gaze was fixed during the experiment and to verify that when a decision was made, a correct answer was not due only to chance. In a first set of experiments, the observers were restricted to read the images at three fixed speeds of image scrolling and were allowed to see each alternative once. In the second set of experiments, the subjects were allowed to scroll through the image stacks at will with no time or gaze limits. In both static-speed and free-scrolling conditions, the four image stacks were displayed simultaneously. All trials were shown at two different image contrasts. Results: The authors were able to determine a histogram of scrolling speeds in frames per second. The scrolling speed of the naïve observers and the radiologists at the moment the signal

Improving the efficiency of gas turbine systems with volumetric solar receivers

International Nuclear Information System (INIS)

Petrakopoulou, Fontina; Sánchez-Delgado, Sergio; Marugán-Cruz, Carolina; Santana, Domingo

2017-01-01

Highlights: • Study of small and large-scale solar-combined cycle plants with volumetric receivers. • Increase of inlet temperature of combustion air using solar energy. • The combustion exergy efficiency starts to decrease over a certain temperature. • Indications obtained from the energy and exergy analyses differ. - Abstract: The combustion process of gas turbine systems is typically associated with the highest thermodynamic inefficiencies among the system components. A method to increase the efficiency of a combustor and, consequently that of the gas turbine, is to increase the temperature of the entering combustion air. This measure reduces the consumption of fuel and improves the environmental performance of the turbine. This paper studies the incorporation of a volumetric solar receiver into existing gas turbines in order to increase the temperature of the inlet combustion air to 800 °C and 1000 °C. For the first time, detailed thermodynamic analyses involving both energy and exergy principles of both small-scale and large-scale hybrid (solar-combined cycle) power plants including volumetric receivers are realized. The plants are based on real gas turbine systems, the base operational characteristics of which are derived and reported in detail. It is found that the indications obtained from the energy and exergy analyses differ. The addition of the solar plant achieves an increase in the exergetic efficiency when the conversion of solar radiation into thermal energy (i.e., solar plant efficiency) is not accounted for in the definition of the overall plant efficiency. On the other hand, it is seen that it does not have a significant effect on the energy efficiency. Nevertheless, when the solar efficiency is included in the definition of the overall efficiency of the plants, the addition of the solar receiver always leads to an efficiency reduction. It is found that the exergy efficiency of the combustion chamber depends on the varying air

Remote determination of the velocity index and mean streamwise velocity profiles

Science.gov (United States)

Johnson, E. D.; Cowen, E. A.

2017-09-01

When determining volumetric discharge from surface measurements of currents in a river or open channel, the velocity index is typically used to convert surface velocities to depth-averaged velocities. The velocity index is given by, k=Ub/Usurf, where Ub is the depth-averaged velocity and Usurf is the local surface velocity. The USGS (United States Geological Survey) standard value for this coefficient, k = 0.85, was determined from a series of laboratory experiments and has been widely used in the field and in laboratory measurements of volumetric discharge despite evidence that the velocity index is site-specific. Numerous studies have documented that the velocity index varies with Reynolds number, flow depth, and relative bed roughness and with the presence of secondary flows. A remote method of determining depth-averaged velocity and hence the velocity index is developed here. The technique leverages the findings of Johnson and Cowen (2017) and permits remote determination of the velocity power-law exponent thereby, enabling remote prediction of the vertical structure of the mean streamwise velocity, the depth-averaged velocity, and the velocity index.

Optimized T1- and T2-weighted volumetric brain imaging as a diagnostic tool in very preterm neonates

International Nuclear Information System (INIS)

Nossin-Manor, Revital; Chung, Andrew D.; Morris, Drew; Thomas, Bejoy; Shroff, Manohar M.; Soares-Fernandes, Joao P.; Cheng, Hai-Ling M.; Whyte, Hilary E.A.; Taylor, Margot J.; Sled, John G.

2011-01-01

T1- and T2-W MR sequences used for obtaining diagnostic information and morphometric measurements in the neonatal brain are frequently acquired using different imaging protocols. Optimizing one protocol for obtaining both kinds of information is valuable. To determine whether high-resolution T1- and T2-W volumetric sequences optimized for preterm brain imaging could provide both diagnostic and morphometric value. Thirty preterm neonates born between 24 and 32 weeks' gestational age were scanned during the first 2 weeks after birth. T1- and T2-W high-resolution sequences were optimized in terms of signal-to-noise ratio, contrast-to-noise ratio and scan time and compared to conventional spin-echo-based sequences. No differences were found between conventional and high-resolution T1-W sequences for diagnostic confidence, image quality and motion artifacts. A preference for conventional over high-resolution T2-W sequences for image quality was observed. High-resolution T1 images provided better delineation of thalamic myelination and the superior temporal sulcus. No differences were found for detection of myelination and sulcation using conventional and high-resolution T2-W images. High-resolution T1- and T2-W volumetric sequences can be used in clinical MRI in the very preterm brain to provide both diagnostic and morphometric information. (orig.)

Vessel suppressed chest Computed Tomography for semi-automated volumetric measurements of solid pulmonary nodules.

Science.gov (United States)

Milanese, Gianluca; Eberhard, Matthias; Martini, Katharina; Vittoria De Martini, Ilaria; Frauenfelder, Thomas

2018-04-01

To evaluate whether vessel-suppressed computed tomography (VSCT) can be reliably used for semi-automated volumetric measurements of solid pulmonary nodules, as compared to standard CT (SCT) MATERIAL AND METHODS: Ninety-three SCT were elaborated by dedicated software (ClearRead CT, Riverain Technologies, Miamisburg, OH, USA), that allows subtracting vessels from lung parenchyma. Semi-automated volumetric measurements of 65 solid nodules were compared between SCT and VSCT. The measurements were repeated by two readers. For each solid nodule, volume measured on SCT by Reader 1 and Reader 2 was averaged and the average volume between readers acted as standard of reference value. Concordance between measurements was assessed using Lin's Concordance Correlation Coefficient (CCC). Limits of agreement (LoA) between readers and CT datasets were evaluated. Standard of reference nodule volume ranged from 13 to 366 mm 3 . The mean overestimation between readers was 3 mm 3 and 2.9 mm 3 on SCT and VSCT, respectively. Semi-automated volumetric measurements on VSCT showed substantial agreement with the standard of reference (Lin's CCC = 0.990 for Reader 1; 0.985 for Reader 2). The upper and lower LoA between readers' measurements were (16.3, -22.4 mm 3 ) and (15.5, -21.4 mm 3 ) for SCT and VSCT, respectively. VSCT datasets are feasible for the measurements of solid nodules, showing an almost perfect concordance between readers and with measurements on SCT. Copyright © 2018 Elsevier B.V. All rights reserved.

Sensitivity analysis of an experimental methodology to determine radionuclide diffusion coefficients in granite

International Nuclear Information System (INIS)

Alonso, U.; Missana, T.; Garcia-Gutierrez, M.; Patelli, A.; Rigato, V.

2005-01-01

Full text of publication follows: The long-term quantitative analysis of the migration behaviour of the relevant radionuclides (RN) within the geological barrier of a radioactive waste repository requires, amongst other data, the introduction of reliable transport parameters, as diffusion coefficients. Since the determination of diffusion coefficients within crystalline rocks is complex and requires long experimental times even for non-sorbing radionuclides, the data available in the literature are very scarce. The nuclear ion beam technique RBS (Rutherford Backscattering Spectrometry) that is successfully used to determine diffusion profiles in thin film science is here examined as possible suitable technique to determine the diffusion coefficients of different RN within granite. As first step, the technique sensitivity and limitations to analyse diffusion coefficients in granite samples is evaluated, considering that the technique is especially sensitive to heavy elements. The required experimental conditions in terms of experimental times, concentration and methodology of analysis are discussed. The diffusants were selected accounting the RBS sensitivity but also trying to cover different behaviours of critical RN and a wide range of possible oxidation states. In particular, Cs(I) was chosen as representative fission product, while as relevant actinides or homologues, the diffusion of Th(IV), U(IV) and Eu (III) was studied. The diffusion of these above-mentioned cations is compared to the diffusion of Re, and I as representative of anionic species. The methodology allowed evaluating diffusion coefficients in the granite samples and, for most of the elements, the values obtained are in agreement with the values found in the literature. The diffusion coefficients calculated ranged from 10 -13 to 10 -16 m 2 /s. It is remarkable that the RBS technique is especially promising to determine diffusion coefficients of high-sorbing RN and it is applicable to a wide range

MIDAS. An algorithm for the extraction of modal information from experimentally determined transfer functions

International Nuclear Information System (INIS)

Durrans, R.F.

1978-12-01

In order to design reactor structures to withstand the large flow and acoustic forces present it is necessary to know something of their dynamic properties. In many cases these properties cannot be predicted theoretically and it is necessary to determine them experimentally. The algorithm MIDAS (Modal Identification for the Dynamic Analysis of Structures) which has been developed at B.N.L. for extracting these structural properties from experimental data is described. (author)

Cerebrospinal fluid volumetric MRI mapping as a simple measurement for evaluating brain atrophy

DEFF Research Database (Denmark)

De Vis, J B; Zwanenburg, J J; van der Kleij, L A

2016-01-01

OBJECTIVES: To assess whether volumetric cerebrospinal fluid (CSF) MRI can be used as a surrogate for brain atrophy assessment and to evaluate how the T2 of the CSF relates to brain atrophy. METHODS: Twenty-eight subjects [mean age 64 (sd 2) years] were included; T1-weighted and CSF MRI were......) and medial temporal lobe atrophy (MTA)] was evaluated. RESULTS: Relative total, peripheral subarachnoidal, and ventricular VCSF increased significantly with increased scores on the GCA and MTA (R = 0.83, 0.78 and 0.78 and R = 0.72, 0.62 and 0.86). Total, peripheral subarachnoidal, and ventricular T2...... be a marker of neurodegenerative disease. KEY POINTS: • A 1:11 min CSF MRI volumetric sequence can evaluate brain atrophy. • CSF MRI provides accurate atrophy assessment without partial volume effects. • CSF MRI data can be processed quickly without user interaction. • The measured T 2 of the CSF is related...

Volumetric characteristics and compactability of asphalt rubber mixtures with organic warm mix asphalt additives

Directory of Open Access Journals (Sweden)

A. M. Rodríguez-Alloza

2017-04-01

Full Text Available Warm Mix Asphalt (WMA refers to technologies that reduce manufacturing and compaction temperatures of asphalt mixtures allowing lower energy consumption and reducing greenhouse gas emissions from asphalt plants. These benefits, combined with the effective reuse of a solid waste product, make asphalt rubber (AR mixtures with WMA additives an excellent environmentally-friendly material for road construction. The effect of WMA additives on rubberized mixtures has not yet been established in detail and the lower mixing/compaction temperatures of these mixtures may result in insufficient compaction. In this sense, the present study uses a series of laboratory tests to evaluate the volumetric characteristics and compactability of AR mixtures with organic additives when production/compaction temperatures are decreased. The results of this study indicate that the additives selected can decrease the mixing/compaction temperatures without compromising the volumetric characteristics and compactability.

Volumetric characteristics and compactability of asphalt rubber mixtures with organic warm mix asphalt additives

International Nuclear Information System (INIS)

Rodríguez-Alloza, A.M.; Gallego, J.

2017-01-01

Warm Mix Asphalt (WMA) refers to technologies that reduce manufacturing and compaction temperatures of asphalt mixtures allowing lower energy consumption and reducing greenhouse gas emissions from asphalt plants. These benefits, combined with the effective reuse of a solid waste product, make asphalt rubber (AR) mixtures with WMA additives an excellent environmentally-friendly material for road construction. The effect of WMA additives on rubberized mixtures has not yet been established in detail and the lower mixing/compaction temperatures of these mixtures may result in insufficient compaction. In this sense, the present study uses a series of laboratory tests to evaluate the volumetric characteristics and compactability of AR mixtures with organic additives when production/compaction temperatures are decreased. The results of this study indicate that the additives selected can decrease the mixing/compaction temperatures without compromising the volumetric characteristics and compactability. [es

Determination of the angle of attack on the mexico rotor using experimental data

DEFF Research Database (Denmark)

Yang, Hua; Shen, Wen Zhong; Sørensen, Jens Nørkær

2010-01-01

characteristics from experimental data on the MEXICO (Model Experiments in controlled Conditions) rotor. Detailed surface pressure and Particle Image Velocimetry (PIV) flow field at different rotor azimuth positions were examined for determining the sectional airfoil data. It is worthwhile noting that the present...

Study and modeling of changes in volumetric efficiency of helix conveyors at different rotational speeds and inclination angels by ANFIS and statistical methods

Directory of Open Access Journals (Sweden)

A Zareei

2017-05-01

Full Text Available Introduction Spiral conveyors effectively carry solid masses as free or partly free flow of materials. They create good throughput and they are the perfect solution to solve the problems of transport, due to their simple structure, high efficiency and low maintenance costs. This study aims to investigate the performance characteristics of conveyors as function of auger diameter, rotational speed and handling inclination angle. The performance characteristic was investigated according to volumetric efficiency. In another words, the purpose of this study was obtaining a suitable model for volumetric efficiency changes of steep auger to transfer agricultural products. Three different diameters of auger, five levels of rotational speed and three slope angles were used to investigate the effects of changes in these parameters on volumetric efficiency of auger. The used method is novel in this area and the results show that performance by ANFIS models is much better than common statistical models. Materials and Methods The experiments were conducted in Department of Mechanical Engineering of Agricultural Machinery in Urmia University. In this study, SAYOS cultivar of wheat was used. This cultivar of wheat had hard seeds and the humidity was 12% (based on wet. Before testing, all foreign material was separated from the wheat such as stone, dust, plant residues and green seeds. Bulk density of wheat was 790 kg m-3. The auger shaft of the spiral conveyor was received its rotational force through belt and electric motor and its rotation leading to transfer the product to the output. In this study, three conveyors at diameters of 13, 17.5, and 22.5 cm, five levels of rotational speed at 100, 200, 300, 400, and 500 rpm and three handling angles of 10, 20, and 30º were tested. Adaptive Nero-fuzzy inference system (ANFIS is the combination of fuzzy systems and artificial neural network, so it has both benefits. This system is useful to solve the complex non

Experimental Study of Single Phase Flow in a Closed-Loop Cooling System with Integrated Mini-Channel Heat Sink

Directory of Open Access Journals (Sweden)

Lei Ma

2016-06-01

Full Text Available The flow and heat transfer characteristics of a closed-loop cooling system with a mini-channel heat sink for thermal management of electronics is studied experimentally. The heat sink is designed with corrugated fins to improve its heat dissipation capability. The experiments are performed using variable coolant volumetric flow rates and input heating powers. The experimental results show a high and reliable thermal performance using the heat sink with corrugated fins. The heat transfer capability is improved up to 30 W/cm2 when the base temperature is kept at a stable and acceptable level. Besides the heat transfer capability enhancement, the capability of the system to transfer heat for a long distance is also studied and a fast thermal response time to reach steady state is observed once the input heating power or the volume flow rate are varied. Under different input heat source powers and volumetric flow rates, our results suggest potential applications of the designed mini-channel heat sink in cooling microelectronics.

Prospective motion correction with volumetric navigators (vNavs) reduces the bias and variance in brain morphometry induced by subject motion.

Science.gov (United States)

Tisdall, M Dylan; Reuter, Martin; Qureshi, Abid; Buckner, Randy L; Fischl, Bruce; van der Kouwe, André J W

2016-02-15

Recent work has demonstrated that subject motion produces systematic biases in the metrics computed by widely used morphometry software packages, even when the motion is too small to produce noticeable image artifacts. In the common situation where the control population exhibits different behaviors in the scanner when compared to the experimental population, these systematic measurement biases may produce significant confounds for between-group analyses, leading to erroneous conclusions about group differences. While previous work has shown that prospective motion correction can improve perceived image quality, here we demonstrate that, in healthy subjects performing a variety of directed motions, the use of the volumetric navigator (vNav) prospective motion correction system significantly reduces the motion-induced bias and variance in morphometry. Copyright © 2015 Elsevier Inc. All rights reserved.

Role of 17 beta-estradiol on type IV collagen fibers volumetric density in the basement membrane of bladder wall.

Science.gov (United States)

de Fraga, Rogerio; Dambros, Miriam; Miyaoka, Ricardo; Riccetto, Cássio Luís Zanettini; Palma, Paulo César Rodrigues

2007-10-01

The authors quantified the type IV collagen fibers volumetric density in the basement membrane of bladder wall of ovariectomized rats with and without estradiol replacement. This study was conducted on 40 Wistar rats (3 months old) randomly divided in 4 groups: group 1, remained intact (control); group 2, submitted to bilateral oophorectomy and daily replacement 4 weeks later of 17 beta-estradiol for 12 weeks; group 3, sham operated and daily replacement 4 weeks later of sesame oil for 12 weeks; and group 4, submitted to bilateral oophorectomy and killed after 12 weeks. It was used in immunohistochemistry evaluation using type IV collagen polyclonal antibody to stain the fibers on paraffin rat bladder sections. The M-42 stereological grid system was used to analyze the fibers. Ovariectomy had an increase effect on the volumetric density of the type IV collagen fibers in the basement membrane of rat bladder wall. Estradiol replacement in castrated animals demonstrated a significative difference in the stereological parameters when compared to the castrated group without hormonal replacement. Surgical castration performed on rats induced an increasing volumetric density of type IV collagen fibers in the basement membrane of rats bladder wall and the estradiol treatment had a significant effect in keeping a low volumetric density of type IV collagen fibers in the basement membrane of rats bladder wall.

3-dimensional charge collection efficiency measurements using volumetric tomographic reconstruction

Energy Technology Data Exchange (ETDEWEB)

Dobos, Daniel [CERN, Geneva (Switzerland)

2016-07-01

For a better understanding of the electrical field distribution of 3D semiconductor detectors and to allow efficiency based design improvements, a method to measure the 3D spatial charge collection efficiency of planar, 3D silicon and diamond sensors using 3D volumetric reconstruction techniques is possible. Simulation results and first measurements demonstrated the feasibility of this method and show that with soon available 10 times faster beam telescopes even small structures and efficiency differences will become measurable in few hours.

Determining the parity of a permutation using an experimental NMR qutrit

International Nuclear Information System (INIS)

Dogra, Shruti; Arvind,; Dorai, Kavita

2014-01-01

We present the NMR implementation of a recently proposed quantum algorithm to find the parity of a permutation. In the usual qubit model of quantum computation, it is widely believed that computational speedup requires the presence of entanglement and thus cannot be achieved by a single qubit. On the other hand, a qutrit is qualitatively more quantum than a qubit because of the existence of quantum contextuality and a single qutrit can be used for computing. We use the deuterium nucleus oriented in a liquid crystal as the experimental qutrit. This is the first experimental exploitation of a single qutrit to carry out a computational task. - Highlights: • NMR implementation of a quantum algorithm to determine the parity of a permutation. • Algorithm implemented on a single qutrit. • Computational speedup achieved without quantum entanglement. • Single qutrit shows quantum contextuality

The puzzle of the 1996 Bárdarbunga, Iceland, earthquake: no volumetric component in the source mechanism

Science.gov (United States)

Tkalcic, Hrvoje; Dreger, Douglas S.; Foulger, Gillian R.; Julian, Bruce R.

2009-01-01

A volcanic earthquake with Mw 5.6 occurred beneath the Bárdarbunga caldera in Iceland on 29 September 1996. This earthquake is one of a decade-long sequence of  events at Bárdarbunga with non-double-couple mechanisms in the Global Centroid Moment Tensor catalog. Fortunately, it was recorded well by the regional-scale Iceland Hotspot Project seismic experiment. We investigated the event with a complete moment tensor inversion method using regional long-period seismic waveforms and a composite structural model. The moment tensor inversion using data from stations of the Iceland Hotspot Project yields a non-double-couple solution with a 67% vertically oriented compensated linear vector dipole component, a 32% double-couple component, and a statistically insignificant (2%) volumetric (isotropic) contraction. This indicates the absence of a net volumetric component, which is puzzling in the case of a large volcanic earthquake that apparently is not explained by shear slip on a planar fault. A possible volcanic mechanism that can produce an earthquake without a volumetric component involves two offset sources with similar but opposite volume changes. We show that although such a model cannot be ruled out, the circumstances under which it could happen are rare.

Experimental Verification of a Simple Method for Accurate Center of Gravity Determination of Small Satellite Platforms

Directory of Open Access Journals (Sweden)

Dario Modenini

2018-01-01

Full Text Available We propose a simple and relatively inexpensive method for determining the center of gravity (CoG of a small spacecraft. This method, which can be ascribed to the class of suspension techniques, is based on dual-axis inclinometer readings. By performing two consecutive suspensions from two different points, the CoG is determined, ideally, as the intersection between two lines which are uniquely defined by the respective rotations. We performed an experimental campaign to verify the method and assess its accuracy. Thanks to a quantitative error budget, we obtained an error distribution with simulations, which we verified through experimental tests. The retrieved experimental error distribution agrees well with the results predicted through simulations, which in turn lead to a CoG error norm smaller than 2 mm with 95% confidence level.

Experimental study of starting plumes simulating cumulus cloud flows in the atmosphere

Science.gov (United States)

Subrahmanyam, Duvvuri; Sreenivas, K. R.; Bhat, G. S.; Diwan, S. S.; Narasimha, Roddam

2009-11-01

Turbulent jets and plumes subjected to off-source volumetric heating have been studied experimentally and numerically by Narasimha and co-workers and others over the past two decades. The off-source heating attempts to simulate the latent heat release that occurs in cumulus clouds on condensation of water vapour. This heat release plays a crucial role in determining the overall cloud shape among other things. Previous studies investigated steady state jets and plumes that had attained similarity upstream of heat injection. A better understanding and appreciation of the fluid dynamics of cumulus clouds should be possible by study of starting plumes. Experiments have been set up at JNCASR (Bangalore) using experimental techniques developed previously but incorporating various improvements. Till date, experiments have been performed on plumes at Re of 1000 and 2250, with three different heating levels in each case. Axial sections of the flow have been studied using standard PLIF techniques. The flow visualization provides us with data on the temporal evolution of the starting plume. It is observed that the broad nature of the effect of off-source heating on the starting plumes is generally consistent with the results obtained previously on steady state flows. More complete results and a critical discussion will be presented at the upcoming meeting.

Spectrophotometric Determination of Nitrate and Phosphate Levels ...

African Journals Online (AJOL)

MBI

2013-04-09

Apr 9, 2013 ... may help in the growth of algae (Beavington,. 1977). Determination of phosphate ion in drinking water. 50cm3 of water sample was pipetted into a 500cm3 volumetric flask, 5cm3 of Ammonium molybdate solution and 3.0cm3 of ascorbic acid were added with swirling, the mixture was diluted to the mark with ...

Image processing. Volumetric analysis with a digital image processing system. [GAMMA]. Bildverarbeitung. Volumetrie mittels eines digitalen Bildverarbeitungssystems

Energy Technology Data Exchange (ETDEWEB)

Kindler, M; Radtke, F; Demel, G

1986-01-01

The book is arranged in seven sections, describing various applications of volumetric analysis using image processing systems, and various methods of diagnostic evaluation of images obtained by gamma scintigraphy, cardic catheterisation, and echocardiography. A dynamic ventricular phantom is explained that has been developed for checking and calibration for safe examination of patient, the phantom allowing extensive simulation of volumetric and hemodynamic conditions of the human heart: One section discusses the program development for image processing, referring to a number of different computer systems. The equipment described includes a small non-expensive PC system, as well as a standardized nuclear medical diagnostic system, and a computer system especially suited to image processing.

Gravimetric and volumetric approaches adapted for hydrogen sorption measurements with in situ conditioning on small sorbent samples

International Nuclear Information System (INIS)

Poirier, E.; Chahine, R.; Tessier, A.; Bose, T.K.

2005-01-01

We present high sensitivity (0 to 1 bar, 295 K) gravimetric and volumetric hydrogen sorption measurement systems adapted for in situ sample conditioning at high temperature and high vacuum. These systems are designed especially for experiments on sorbents available in small masses (mg) and requiring thorough degassing prior to sorption measurements. Uncertainty analysis from instrumental specifications and hydrogen absorption measurements on palladium are presented. The gravimetric and volumetric systems yield cross-checkable results within about 0.05 wt % on samples weighing from (3 to 25) mg. Hydrogen storage capacities of single-walled carbon nanotubes measured at 1 bar and 295 K with both systems are presented

Mathematical estimation of the level of microbial contamination on spacecraft surfaces by volumetric air sampling

Science.gov (United States)

Oxborrow, G. S.; Roark, A. L.; Fields, N. D.; Puleo, J. R.

1974-01-01

Microbiological sampling methods presently used for enumeration of microorganisms on spacecraft surfaces require contact with easily damaged components. Estimation of viable particles on surfaces using air sampling methods in conjunction with a mathematical model would be desirable. Parameters necessary for the mathematical model are the effect of angled surfaces on viable particle collection and the number of viable cells per viable particle. Deposition of viable particles on angled surfaces closely followed a cosine function, and the number of viable cells per viable particle was consistent with a Poisson distribution. Other parameters considered by the mathematical model included deposition rate and fractional removal per unit time. A close nonlinear correlation between volumetric air sampling and airborne fallout on surfaces was established with all fallout data points falling within the 95% confidence limits as determined by the mathematical model.

Studies on the rheology and oxygen mass transfer in the clavulanic acid production by Streptomyces clavuligerus

Directory of Open Access Journals (Sweden)

E. R. Gouveia

2000-12-01

Full Text Available In the present work rheological characteristics and volumetric oxygen transfer coefficient (kLa were investigated during batch cultivations of Streptomyces clavuligerus NRRL 3585 for production of clavulanic acid. The experimental rheological data could be adequately described in terms of the power law model and logistic equation. Significant changes in the rheological parameters consistency index (K and flow behavior index (n were observed with the fermentation evolution. Interesting correlations between the consistency index (K/biomass concentration (C X and the flow behavior index (n/biomass concentration were proposed. Volumetric oxygen mass transfer coefficient (kLa was determined by the gas balance method. Classical correlation relating the volumetric oxygen mass transfer coefficient to the operating conditions, physical and to transport properties, including apparent viscosity (muap, could be applied to the experimental results.

Synchronous prostate and rectal adenocarcinomas irradiation utilising volumetric modulated arc therapy

OpenAIRE

Ng, Sweet Ping; Tran, Thu; Moloney, Philip; Sale, Charlotte; Mathlum, Maitham; Ong, Grace; Lynch, Rod

2015-01-01

Abstract Cases of synchronous prostate and colorectal adenocarcinomas have been sporadically reported. There are case reports on patients with synchronous prostate and rectal cancers treated with external beam radiotherapy alone or combined with high?dose rate brachytherapy boost to the prostate. Here, we illustrate a patient with synchronous prostate and rectal cancers treated using the volumetric arc therapy (VMAT) technique. The patient was treated with radical radiotherapy to 50.4 Gy in 2...

Linac-based total body irradiation (TBI) with volumetric modulated arc therapy (VMAT)

Science.gov (United States)

Tas, B.; Durmus, I. F.; Okumus, A.; Uzel, O. E.

2017-02-01

To evaluate dose distribution of Volumetric modulated arc therapy (VMAT) planning tecnique using Versa HD® lineer accelerator to deliver Total Body Irradiation (TBI) on the coach. Eight TBI patient's Treatment Planning System (TPS) were performed with dual arc VMAT for each patient. The VMAT-TBI consisted of three isocentres and three dual overlapping arcs. The prescribed dose was 12 Gy. Mean dose to lung and kidney were restricted less than 10 Gy and max. dose to lens were restricted less than 6 Gy. The plans were verified using 2D array and ion chamber. The comparison between calculation and measurement were made by γ-index analysis and absolute dose. An average total delivery time was determined 923±34 seconds and an average MU was determined 2614±228 MUs for dual arc VMAT. Mean dose to lungs was 9.7±0.2 Gy, mean dose to kidneys was 8.8±0.3 Gy, max. dose to lens was 5.5±0.3 Gy and max. dose was 14.6±0.3 Gy, HI of PTV was 1.13±0.2, mean dose to PTV was 12.6±1.5 Gy and mean γ-index pass rate was %97.1±1.9. The results show that the tecnique for TBI using VMAT on the treatment coach is feasible.

4D-SPECT/CT in orthopaedics: a new method of combined quantitative volumetric 3D analysis of SPECT/CT tracer uptake and component position measurements in patients after total knee arthroplasty

Energy Technology Data Exchange (ETDEWEB)

Rasch, Helmut; Falkowski, Anna L.; Forrer, Flavio [Kantonsspital Baselland, Institute for Radiology and Nuclear Medicine, Bruderholz (Switzerland); Henckel, Johann [Imperial College London, London (United Kingdom); Hirschmann, Michael T. [Kantonsspital Baselland, Department of Orthopaedic Surgery and Traumatology, Bruderholz (Switzerland)

2013-09-15

The purpose was to evaluate the intra- and inter-observer reliability of combined quantitative 3D-volumetric single-photon emission computed tomography (SPECT)/CT analysis including size, intensity and localisation of tracer uptake regions and total knee arthroplasty (TKA) position. Tc-99m-HDP-SPECT/CT of 100 knees after TKA were prospectively analysed. The anatomical areas represented by a previously validated localisation scheme were 3D-volumetrically analysed. The maximum intensity was recorded for each anatomical area. Ratios between the respective value and the mid-shaft of the femur as the reference were calculated. Femoral and tibial TKA position (varus-valgus, flexion-extension, internal rotation- external rotation) were determined on 3D-CT. Two consultant radiologists/nuclear medicine physicians interpreted the SPECT/CTs twice with a 2-week interval. The inter- and intra-observer reliability was determined (ICCs). Kappa values were calculated for the area with the highest tracer uptake between the observers. The measurements of tracer uptake intensity showed excellent inter- and intra-observer reliabilities for all regions (tibia, femur and patella). Only the tibial shaft area showed ICCs <0.89. The kappa values were almost perfect (0.856, p < 0.001; 95 % CI 0.778, 0.922). For measurements of the TKA position, there was strong agreement within and between the readings of the two observers; the ICCs for the orientation of TKA components for inter- and intra-observer reliability were nearly perfect (ICCs >0.84). This combined 3D-volumetric standardised method of analysing the location, size and the intensity of SPECT/CT tracer uptake regions (''hotspots'') and the determination of the TKA position was highly reliable and represents a novel promising approach to biomechanics. (orig.)

Experimental determination of the boundary condition for diffuse photons in a homogeneous turbid medium

International Nuclear Information System (INIS)

Everitt, David L.; Zhu, Tuo; Zhu, H.-M.; Zhu, X. D.

2000-01-01

We present a simple experimental method that permits an empirical determination of the effective boundary condition and the extrapolated end point for the diffuse photon density in a homogeneous turbid medium. (c) 2000 Optical Society of America

Experimental determination of the Ta–Ge phase diagram

Energy Technology Data Exchange (ETDEWEB)

Araújo Pinto da Silva, Antonio Augusto, E-mail: aaaps@ppgem.eel.usp.br [EEL/USP – Escola de Engenharia de Lorena (EEL), Universidade de São Paulo (USP), Pólo Urbo-Industrial Gleba AI-6, 12602-810 Lorena, SP (Brazil); Coelho, Gilberto Carvalho [EEL/USP – Escola de Engenharia de Lorena (EEL), Universidade de São Paulo (USP), Pólo Urbo-Industrial Gleba AI-6, 12602-810 Lorena, SP (Brazil); UniFoa – Centro Universitário de Volta Redonda, Núcleo de Pesquisa, Campus Três Poços, Avenida Paulo Erlei Alves Abrantes, 1325, Bairro Três Poços, 27240-560 Volta Redonda, RJ (Brazil); Nunes, Carlos Angelo; Suzuki, Paulo Atsushi [EEL/USP – Escola de Engenharia de Lorena (EEL), Universidade de São Paulo (USP), Pólo Urbo-Industrial Gleba AI-6, 12602-810 Lorena, SP (Brazil); Fiorani, Jean Marc; David, Nicolas; Vilasi, Michel [Université de Lorraine, Institut Jean Lamour, Faculté des Sciences et Technologies, BP 70239, F-54506 Vandoeuvre-lès-Nancy (France)

2013-11-05

Highlights: •Ta–Ge phase diagram propose for the first time. •The phase αTa{sub 5}Ge{sub 3} was not observed in samples investigated in this work. •Three eutectics reactions where determined with the liquid compositions at 20.5; 28.0; 97.0 at.% Ge. -- Abstract: In the present work, the Ta–Ge phase diagram has been experimentally studied, considering the inexistence of a Ta–Ge phase diagram in the literature. The samples were prepared via arc melting and characterized by Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS) and X-ray Diffraction (XRD). The intermetallics phases βTa{sub 3}Ge, αTa{sub 3}Ge, βTa{sub 5}Ge{sub 3} and TaGe{sub 2} where confirmed in this system. Three eutectics reactions where determined with the liquid compositions at 20.5; 28.0; 97.0 at.% Ge. The phases βTa{sub 3}Ge and βTa{sub 5}Ge{sub 3} solidifies congruently while TaGe{sub 2} is formed through a peritectic transformation. The temperature of the Ta-rich eutectic (L ↔ Ta{sub ss} + βTa{sub 3}Ge) was measured by the Pirani-Alterthum method at 2440 °C and the Ge-rich eutectic (L ↔ TaGe{sub 2} + Ge{sub ss}) by DTA at 937 °C.

Impact of errors in recorded compressed breast thickness measurements on volumetric density classification using volpara v1.5.0 software

OpenAIRE

Waade, G; Highnam, R; Hauge, I; McEntee, M; Hofvind, S; Denton, E; Kelly, J; Sarwar, J; Hogg, P

2016-01-01

Purpose: Mammographic density has been demonstrated to predict breast cancer risk. It has been proposed that it could be used for stratifying screening pathways and recommending additional imaging. Volumetric density tools use the recorded compressed breast thickness (CBT) of the breast measured at the x-ray unit in their calculation, however the accuracy of the recorded thickness can vary. The aim of this study was to investigate whether inaccuracies in recorded CBT impact upon volumetric de...

Experimental and molecular dynamics simulation study of the sublimation energetics of cyclopentadienyltricarbonylmanganese (Cymantrene).

Science.gov (United States)

Picciochi, Ricardo; Canongia Lopes, José N; Diogo, Hermínio P; Minas da Piedade, Manuel E

2008-10-16

The standard molar enthalpy of sublimation of monoclinic cyclopentadienyltricarbonylmanganese, Mn(eta (5)-C 5H 5)(CO) 3, at 298.15 K, was determined as Delta sub H m (o)[Mn(eta (5)-C 5H 5)(CO) 3] = 75.97 +/- 0.37 kJ x mol (-1) from Knudsen effusion and Calvet-drop microcalorimetry measurements, thus considerably improving the very large inaccuracy (>10 kJ x mol (-1)) of the published data. The obtained value was used to assess the extension of the OPLS-based all-atom force field we previously developed for iron metallocenes to manganese organometallic compounds. The modified force field was able to reproduce the volumetric properties (density and unit-cell volume) of crystalline Mn(eta (5)-C 5H 5)(CO) 3 with a deviation of 0.6% and the experimentally determined enthalpy of sublimation with an accuracy of 1 kJ x mol (-1). The interaction (epsilon) and atomic-diameter (sigma) parameters of the Lennard-Jones (12-6) potential function used to calculate dispersion contributions within the framework of the force field were found to be transferable from iron to manganese.

SU-E-J-217: Accuracy Comparison Between Surface and Volumetric Registrations for Patient Setup of Head and Neck Radiation Therapy

International Nuclear Information System (INIS)

Kim, Y; Li, R; Na, Y; Jenkins, C; Xing, L; Lee, R

2014-01-01

Purpose: Optical surface imaging has been applied to radiation therapy patient setup. This study aims to investigate the accuracy of the surface registration of the optical surface imaging compared with that of the conventional method of volumetric registration for patient setup in head and neck radiation therapy. Methods: Clinical datasets of planning CT and treatment Cone Beam CT (CBCT) were used to compare the surface and volumetric registrations in radiation therapy patient setup. The Iterative Closest Points based on point-plane closest method was implemented for surface registration. We employed 3D Slicer for rigid volumetric registration of planning CT and treatment CBCT. 6 parameters of registration results (3 rotations and 3 translations) were obtained by the two registration methods, and the results were compared. Digital simulation tests in ideal cases were also performed to validate each registration method. Results: Digital simulation tests showed that both of the registration methods were accurate and robust enough to compare the registration results. In experiments with the actual clinical data, the results showed considerable deviation between the surface and volumetric registrations. The average root mean squared translational error was 2.7 mm and the maximum translational error was 5.2 mm. Conclusion: The deviation between the surface and volumetric registrations was considerable. Special caution should be taken in using an optical surface imaging. To ensure the accuracy of optical surface imaging in radiation therapy patient setup, additional measures are required. This research was supported in part by the KIST institutional program (2E24551), the Industrial Strategic technology development program (10035495) funded by the Ministry of Trade, Industry and Energy (MOTIE, KOREA), and the Radiation Safety Research Programs (1305033) through the Nuclear Safety and Security Commission, and the NIH (R01EB016777)

SU-E-J-217: Accuracy Comparison Between Surface and Volumetric Registrations for Patient Setup of Head and Neck Radiation Therapy

Energy Technology Data Exchange (ETDEWEB)

Kim, Y [Stanford University School of Medicine, Stanford, CA (United States); Korea Institute of Science and Technology, Seoul (Korea, Republic of); Li, R; Na, Y; Jenkins, C; Xing, L [Stanford University School of Medicine, Stanford, CA (United States); Lee, R [Ewha Womans University, Seoul (Korea, Republic of)

2014-06-01

Purpose: Optical surface imaging has been applied to radiation therapy patient setup. This study aims to investigate the accuracy of the surface registration of the optical surface imaging compared with that of the conventional method of volumetric registration for patient setup in head and neck radiation therapy. Methods: Clinical datasets of planning CT and treatment Cone Beam CT (CBCT) were used to compare the surface and volumetric registrations in radiation therapy patient setup. The Iterative Closest Points based on point-plane closest method was implemented for surface registration. We employed 3D Slicer for rigid volumetric registration of planning CT and treatment CBCT. 6 parameters of registration results (3 rotations and 3 translations) were obtained by the two registration methods, and the results were compared. Digital simulation tests in ideal cases were also performed to validate each registration method. Results: Digital simulation tests showed that both of the registration methods were accurate and robust enough to compare the registration results. In experiments with the actual clinical data, the results showed considerable deviation between the surface and volumetric registrations. The average root mean squared translational error was 2.7 mm and the maximum translational error was 5.2 mm. Conclusion: The deviation between the surface and volumetric registrations was considerable. Special caution should be taken in using an optical surface imaging. To ensure the accuracy of optical surface imaging in radiation therapy patient setup, additional measures are required. This research was supported in part by the KIST institutional program (2E24551), the Industrial Strategic technology development program (10035495) funded by the Ministry of Trade, Industry and Energy (MOTIE, KOREA), and the Radiation Safety Research Programs (1305033) through the Nuclear Safety and Security Commission, and the NIH (R01EB016777)

Experimental determination of magnetization curves of switched reluctance motors

Energy Technology Data Exchange (ETDEWEB)

Andrada, P.; Martinez, E.; Perat, J.I.; Sanchez, J.A.; Torrent, M. [Universitat Politecnica de Catalunya, UPC, Dept. of Enginyeria Electrica, Vilanova i la Geltru (Spain)

2000-08-01

Knowledge of magnetic characteristics or magnetization curves of switched reluctance motors is very important for their design and performance evaluation. A test equipment for determination of magnetisation curves of switched reluctance motors is presented. This test equipment is based on a method of measurement of inductance by means of DC current proposed by C.V. Jones, in which a bridge arrangement is used in order to eliminate resistance effects. The main advantage of this setup is that it is an automatic system controlled by P.C., providing easy and user friendly presentation of test results and reducing measurement time and manual errors. Several switched reluctance motors with different structures have been tested using the proposed equipment, giving a good agreement with other experimental and numerical methods. (orig.)

Experimental determination of lattice parameters for 2% enriched uranium heavy water reactor cores

Energy Technology Data Exchange (ETDEWEB)

Raisic, N; Takac, S; Markovic, H; Bosevski, T [Boris Kidric Institute of Nuclear Sciences Vinca, Belgrade (Yugoslavia)

1963-04-15

Systematic measurements of the buckling, infinite multiplication factor and the thermal utilization factor were made on a series of lattices for 2% enriched uranium tubular fuel elements in heavy water. This work represents the first phase of experimental verification of standard theoretical methods used for the determination of reactor parameters.

Experimental determination of isotope enrichment factors – bias from mass removal by repetitive sampling

DEFF Research Database (Denmark)

Buchner, Daniel; Jin, Biao; Ebert, Karin

2017-01-01

to account for mass removal and for volatilization into the headspace. In this study we use both synthetic and experimental data to demonstrate that the determination of ε-values according to current correction methods is prone to considerable systematic errors even in well-designed experimental setups....... Application of inappropriate methods may lead to incorrect and inconsistent ε-values entailing misinterpretations regarding the processes underlying isotope fractionation. In fact, our results suggest that artifacts arising from inappropriate data evaluation might contribute to the variability of published ε...

Experimental study of flame stability in biogas premix system

International Nuclear Information System (INIS)

Diaz G, Carlos A; Amell A Andres; Cardona Luis F

2008-01-01

Utilization of new renewable energy sources have had a special interest in last years looking for decrease the dependence of fossil fuels and the environmental impact generated for them. This work studies experimentally the flame stability of a simulated biogas with a volumetric composition of 60% methane and 40% carbon dioxide. The objective of this study is to obtain information about design and interchangeability of gases in premixed combustion systems that operate with different fuel gases. The critical velocity gradient was the stability criteria used. Utilization of this criteria and the experimental method followed, using a partial premixed burner, stability flame diagram of biogas studied had been obtained. Presence of carbon dioxide has a negative effect in flame stability, decreasing significantly the laminar flame speed and consequently, the stability range of biogas burners because of apparition of blow off.

Conjugate transient natural convection in a cylindrical enclosure with internal volumetric heat generation

International Nuclear Information System (INIS)

Sharma, Anil Kumar; Velusamy, K.; Balaji, C.

2008-01-01

This paper reports the results of a numerical investigation of transient turbulent natural convection heat transfer from a volumetric energy generating source placed inside a cylindrical enclosure filled with low Prandtl number fluid (liquid sodium, Pr = 0.005). Two-dimensional conservation equations of mass, momentum and energy, coupled with the Boussinesq approximation, are solved using a finite volume based discretisation method employing the SIMPLE algorithm for the pressure velocity coupling. Turbulence is modeled using the k-ε model with physical boundary conditions. The study presents the transient features of confined turbulent natural convection, due to time varying generation of heat in the volumetric source. The intensity of heat source exponentially decays with time and the source is placed over circular plates with a central opening. Results obtained from the numerical model compare favorably with those reported in the literature for steady state natural convection. Numerical simulations are carried out to display the sequential evolution of flow and thermal fields and the maximum temperature reached in the source. The advantages of distributing the heat source on multi trays have been quantified

Efficient Algorithms for Real-Time GPU Volumetric Cloud Rendering with Enhanced Geometry

OpenAIRE

Carlos Jiménez de Parga; Sebastián Rubén Gómez Palomo

2018-01-01

This paper presents several new techniques for volumetric cloud rendering using efficient algorithms and data structures based on ray-tracing methods for cumulus generation, achieving an optimum balance between realism and performance. These techniques target applications such as flight simulations, computer games, and educational software, even with conventional graphics hardware. The contours of clouds are defined by implicit mathematical expressions or triangulated structures inside which ...

Combined use of biochemical and volumetric biomarkers to assess the risk of conversion of mild cognitive impairment to Alzheimer’s disease

Directory of Open Access Journals (Sweden)

Marta Nesteruk

2016-12-01

Full Text Available Introduction : The aim of our study was to evaluate the usefulness of several biomarkers in predicting the conversion of mild cognitive impairment (MCI to Alzheimer’s disease (AD: β-amyloid and tau proteins in cerebrospinal fluid and the volumetric evaluation of brain structures including the hippocampus in magnetic resonance imaging (MRI. Material and methods : MRI of the brain with the volumetric assessment of hippocampus, entorhinal cortex, posterior cingulate gyrus, parahippocampal gyrus, superior, medial and inferior temporal gyri was performed in 40 patients diagnosed with mild cognitive impairment. Each patient had a lumbar puncture to evaluate β-amyloid and tau protein (total and phosphorylated levels in the cerebrospinal fluid. The observation period was 2 years. Results : Amongst 40 patients with MCI, 9 (22.5% converted to AD within 2 years of observation. Discriminant analysis was conducted and sensitivity for MCI conversion to AD on the basis of volumetric measurements was 88.9% and specificity 90.3%; on the basis of β-amyloid and total tau, sensitivity was 77.8% and specificity 83.9%. The combined use of the results of volumetric measurements with the results of proteins in the cerebrospinal fluid did not increase the sensitivity (88.9% but increased specificity to 96.8% and the percentage of correct classification to 95%.

A genetic meta-algorithm-assisted inversion approach: hydrogeological study for the determination of volumetric rock properties and matrix and fluid parameters in unsaturated formations

Science.gov (United States)

Szabó, Norbert Péter

2018-03-01

An evolutionary inversion approach is suggested for the interpretation of nuclear and resistivity logs measured by direct-push tools in shallow unsaturated sediments. The efficiency of formation evaluation is improved by estimating simultaneously (1) the petrophysical properties that vary rapidly along a drill hole with depth and (2) the zone parameters that can be treated as constant, in one inversion procedure. In the workflow, the fractional volumes of water, air, matrix and clay are estimated in adjacent depths by linearized inversion, whereas the clay and matrix properties are updated using a float-encoded genetic meta-algorithm. The proposed inversion method provides an objective estimate of the zone parameters that appear in the tool response equations applied to solve the forward problem, which can significantly increase the reliability of the petrophysical model as opposed to setting these parameters arbitrarily. The global optimization meta-algorithm not only assures the best fit between the measured and calculated data but also gives a reliable solution, practically independent of the initial model, as laboratory data are unnecessary in the inversion procedure. The feasibility test uses engineering geophysical sounding logs observed in an unsaturated loessy-sandy formation in Hungary. The multi-borehole extension of the inversion technique is developed to determine the petrophysical properties and their estimation errors along a profile of drill holes. The genetic meta-algorithmic inversion method is recommended for hydrogeophysical logging applications of various kinds to automatically extract the volumetric ratios of rock and fluid constituents as well as the most important zone parameters in a reliable inversion procedure.

Experimental conditions for determination of the neutrino mass hierarchy with reactor antineutrinos

Directory of Open Access Journals (Sweden)

Myoung Youl Pac

2016-01-01

Full Text Available This article reports the optimized experimental requirements to determine neutrino mass hierarchy using electron antineutrinos (ν¯e generated in a nuclear reactor. The features of the neutrino mass hierarchy can be extracted from the |Δm312| and |Δm322| oscillations by applying the Fourier sine and cosine transforms to the L/E spectrum. To determine the neutrino mass hierarchy above 90% probability, the requirements on the energy resolution as a function of the baseline are studied at sin2⁡2θ13=0.1. If the energy resolution of the neutrino detector is less than 0.04/Eν and the determination probability obtained from Bayes' theorem is above 90%, the detector needs to be located around 48–53 km from the reactor(s to measure the energy spectrum of ν¯e. These results will be helpful for setting up an experiment to determine the neutrino mass hierarchy, which is an important problem in neutrino physics.

Improved Second-Generation 3-D Volumetric Display System. Revision 2

Science.gov (United States)

1998-10-01

computer control, uses infrared lasers to address points within a rare-earth-infused solid glass cube. Already, simple animated computer-generated images...Volumetric Display System permits images to be displayed in a three- dimensional format that can be observed without the use of special glasses . Its...MM 120 nm 60 mm nI POLARIZING I $-"• -’’""BEAMSPLI’i-ER ) 4P40-MHz 50-MHz BW PLRZN i TeO2 MODULATORS TeO2 DEFLECTORS Figure 1-4. NEOS four-channel

Un nouveau moyen de mesure absolue du taux gazeux des mélanges gaz-liquides : le SMAC A New Absolute Measurement of the Volumetric Gas Ratio of Gas-Liquid Mixture: the Smac

Directory of Open Access Journals (Sweden)

Porot P.

2006-11-01

and P index 0 the sample initial pressure. Numerical simulations indicate that the pressurization must be regular and fast enough to avoid the problems coming from dissolution. They also indicate that small leakage could be profitable by decreasing the maximum pressure needed to meet the inflexion without modifying the measurement. The experimental verification consists in measuring the (P,V graphs during the pressurization of different known mixture samples. The positions of the inflexion points of the log log graphs were compared with the known volumetric gas ratio. The correlation is very good and the deviations were inside the error range of the preparation of the mixture samples. Based on this principle, a system of oil aeration measurement has been developped : the SMAC (french name for Compressibility based oil Aeration Measurement System. The system is able to take samples from a given circuit by electrovalves. The sample is then regularly pressurized by a piston; pressure, piston displacement and temperature are stored along the time in a PC. The inflexion point is then determined, the gas ratio calculated and printed by a soft on the PC. The whole operation takes around three minutes. This apparatus has been used for two studies. The first one was dealing with hydraulic valve lash adhusters (HLA. The SMAC was measuring the gas ratio of oil in the circuit. The aim was to evaluate the influence of aeration on the HLA. The second study consists in defining a new oil aeration test method to measure the influence of silicone additives on aeration. Generally speaking, the SMAC principle can be used on almost any gas liquid mixture to measure the volumetric gas ration.

The pineal organ of bats: a comparative morphological and volumetric investigation.

OpenAIRE

Bhatnagar, K P; Frahm, H D; Stephan, H

1986-01-01

Bats are seasonal breeders and roost under a wide range of lighting conditions, from broad daylight to the total darkness of subterranean passageways and caves. Some are true hibernators. These characteristics and the paucity of information on their pineal organ prompted this investigation, which is based upon the pineals of 191 specimens of 88 species and 12 families of bats. Comparative morphological and volumetric observations have been made on serially sectioned brains of each species. Da...

An initial study on the estimation of time-varying volumetric treatment images and 3D tumor localization from single MV cine EPID images

Energy Technology Data Exchange (ETDEWEB)

Mishra, Pankaj, E-mail: pankaj.mishra@varian.com; Mak, Raymond H.; Rottmann, Joerg; Bryant, Jonathan H.; Williams, Christopher L.; Berbeco, Ross I.; Lewis, John H. [Brigham and Women' s Hospital, Dana-Farber Cancer Institute and Harvard Medical School, Boston, Massachusetts 02115 (United States); Li, Ruijiang [Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California 94305 (United States)

2014-08-15

Purpose: In this work the authors develop and investigate the feasibility of a method to estimate time-varying volumetric images from individual MV cine electronic portal image device (EPID) images. Methods: The authors adopt a two-step approach to time-varying volumetric image estimation from a single cine EPID image. In the first step, a patient-specific motion model is constructed from 4DCT. In the second step, parameters in the motion model are tuned according to the information in the EPID image. The patient-specific motion model is based on a compact representation of lung motion represented in displacement vector fields (DVFs). DVFs are calculated through deformable image registration (DIR) of a reference 4DCT phase image (typically peak-exhale) to a set of 4DCT images corresponding to different phases of a breathing cycle. The salient characteristics in the DVFs are captured in a compact representation through principal component analysis (PCA). PCA decouples the spatial and temporal components of the DVFs. Spatial information is represented in eigenvectors and the temporal information is represented by eigen-coefficients. To generate a new volumetric image, the eigen-coefficients are updated via cost function optimization based on digitally reconstructed radiographs and projection images. The updated eigen-coefficients are then multiplied with the eigenvectors to obtain updated DVFs that, in turn, give the volumetric image corresponding to the cine EPID image. Results: The algorithm was tested on (1) Eight digital eXtended CArdiac-Torso phantom datasets based on different irregular patient breathing patterns and (2) patient cine EPID images acquired during SBRT treatments. The root-mean-squared tumor localization error is (0.73 ± 0.63 mm) for the XCAT data and (0.90 ± 0.65 mm) for the patient data. Conclusions: The authors introduced a novel method of estimating volumetric time-varying images from single cine EPID images and a PCA-based lung motion model

Volumetric dispenser for small particles from plural sources

International Nuclear Information System (INIS)

Bradley, R.A.; Miller, W.H.; Sease, J.D.

1975-01-01

Apparatus is described for rapidly and accurately dispensing measured volumes of small particles from a supply hopper. The apparatus includes an adjustable, vertically oriented measuring tube and orifice member defining the volume to be dispensed, a ball plug valve for selectively closing the bottom end of the orifice member, and a compression valve for selectively closing the top end of the measuring tube. A supply hopper is disposed above and in gravity flow communication with the measuring tube. Properly sequenced opening and closing of the two valves provides accurate volumetric discharge through the ball plug valve. A dispensing system is described wherein several appropriately sized measuring tubes, orifice members, and associated valves are arranged to operate contemporaneously to facilitate blending of different particles

Application of three-dimensional volumetric ultrasonography in patients with bladder cancer and its mimickers: A pictorial essay

Energy Technology Data Exchange (ETDEWEB)

Ko, Sujin; Hong, Seong Sook; Hwang, Ji Young; Kim, Hyun Joo [Dept. of Radiology, Soonchunhyang University Seoul Hospital, Seoul (Korea, Republic of)

2017-05-15

Various diseases of the urinary bladder can be demonstrated as being polypoid, a nodular bladder mass or as focal bladder wall thickening. This includes malignant or benign neoplasms, urinary stones, or other inflammatory bladder conditions. In daily practice many of these bladder diseases are easily confused with bladder cancer. On the other hand, ultrasonography (US) is safe and can be easily applied as a screening modality or an initial evaluating tool for urinary bladder disease. Furthermore, additional three-dimensional (3D) volumetric techniques can support more delicate delineation of these lesions. This study presents a 3D volumetric US for bladder lesions, and demonstrates various pathological conditions of the urinary bladder ranging from bladder cancer to other benign lesions.

Determination of left ventricular function parameters and myocardial mass: comparison of MRI and EBT

International Nuclear Information System (INIS)

Kivelitz, D.E.; Enzweiler, C.N.H.; Wiese, T.H.; Lembcke, A.; Taupitz, M.; Hamm, B.; Borges, A.; Zytowski, M.

2000-01-01

Purpose: Comparative volumetric assessment of the left ventricle by magnetic resonance imaging (MRI) and electron beam tomography (EBT) in patients with ischemic and dilated cardiac disease. Methods: Thirty-two patients underwent cine MRI and EBT in the multislice mode. All studies were triggered to the ECG. Left ventricular ejection fraction (EF), enddiastolic (EDV) and endsystolic volume (ESV), and myocardial mass (MM) were determined by 3D-volumetry by MRI and EBT and results were compared. Results: The correlation between MRI and EBT for EF, EDV, ESV, and MM were r=0.86, r=0.95, r=0.95, and r=0.93, respectively. Conclusions: There is an excellent correlation between MRI and EBT in determining left-ventricular parameters. Both methods are suitable for volumetric assessment of the left ventricie. (orig.) [de

Calculation and experimental technique of determination of rolling procedure for cold-rolling tube mills

International Nuclear Information System (INIS)

Igoshin, V.F.; Aleshin, V.A.; Khoroshikh, Yu.G.; Bogatov, A.A.; Mizhiritskij, O.I.

1983-01-01

Calculation and experimental technique of determination of tube cold rolling procedure has been developed. Rolling procedure based on the usage of regression equation epsilon=1.24 psi, where psi is the relative reduction of area, delta-permissible reduction during rolling, has been tested on 08Kh18N10T steel. The effect of tube geometry, tool calibration parameters, lubrication conditions etc. on metal deformability in taking into account experimentally. The use of the technique proposed has allowed to shorten the time of mastering of the production of tubes from different steels

Technical Note: Using experimentally determined proton spot scanning timing parameters to accurately model beam delivery time.

Science.gov (United States)

Shen, Jiajian; Tryggestad, Erik; Younkin, James E; Keole, Sameer R; Furutani, Keith M; Kang, Yixiu; Herman, Michael G; Bues, Martin

2017-10-01

To accurately model the beam delivery time (BDT) for a synchrotron-based proton spot scanning system using experimentally determined beam parameters. A model to simulate the proton spot delivery sequences was constructed, and BDT was calculated by summing times for layer switch, spot switch, and spot delivery. Test plans were designed to isolate and quantify the relevant beam parameters in the operation cycle of the proton beam therapy delivery system. These parameters included the layer switch time, magnet preparation and verification time, average beam scanning speeds in x- and y-directions, proton spill rate, and maximum charge and maximum extraction time for each spill. The experimentally determined parameters, as well as the nominal values initially provided by the vendor, served as inputs to the model to predict BDTs for 602 clinical proton beam deliveries. The calculated BDTs (T BDT ) were compared with the BDTs recorded in the treatment delivery log files (T Log ): ∆t = T Log -T BDT . The experimentally determined average layer switch time for all 97 energies was 1.91 s (ranging from 1.9 to 2.0 s for beam energies from 71.3 to 228.8 MeV), average magnet preparation and verification time was 1.93 ms, the average scanning speeds were 5.9 m/s in x-direction and 19.3 m/s in y-direction, the proton spill rate was 8.7 MU/s, and the maximum proton charge available for one acceleration is 2.0 ± 0.4 nC. Some of the measured parameters differed from the nominal values provided by the vendor. The calculated BDTs using experimentally determined parameters matched the recorded BDTs of 602 beam deliveries (∆t = -0.49 ± 1.44 s), which were significantly more accurate than BDTs calculated using nominal timing parameters (∆t = -7.48 ± 6.97 s). An accurate model for BDT prediction was achieved by using the experimentally determined proton beam therapy delivery parameters, which may be useful in modeling the interplay effect and patient throughput. The model may

Thermal expansion and volumetric changes during indium phosphide melting

International Nuclear Information System (INIS)

Glazov, V.M.; Davletov, K.; Nashel'skij, A.Ya.; Mamedov, M.M.

1977-01-01

The results of the measurements of a thermal expansion were summed up at various temperatures as a diagram in coordinates (Δ 1/1) approximately F(t). It was shown that an appreciable deviation of the relationship (Δ1/1) approximately f(t) from the linear law corresponded to a temperature of 500-550 deg C. It was noted that the said deviation was related to an appreciable thermal decomposition of indium phosphide as temperature increased. The strength of the inter-atomic bond of indium phosphide was calculated. Investigated were the volumetric changes of indium phosphide on melting. The resultant data were analyzed with the aid of the Clausius-Clapeyron equation

Experimental and theoretical determination of the absorption coefficients of X-rays through barium plaster from 100 to 400 keV

International Nuclear Information System (INIS)

Joksimovicj, V.

1976-01-01

The absorption coefficients of X-rays from 100 to 400 keV through barium plaster of equivalent atomic number of 26 have been determined experimentally and theoretically. Calculated values are compared with experimental data. Matrix components of barium plaster were determined chemically and by X-ray fluorescence

SU-F-J-54: Towards Real-Time Volumetric Imaging Using the Treatment Beam and KV Beam

Energy Technology Data Exchange (ETDEWEB)

Chen, M; Rozario, T; Liu, A; Jiang, S; Lu, W [UT Southwestern Medical Center, Dallas, TX (United States)

2016-06-15

Purpose: Existing real-time imaging uses dual (orthogonal) kV beam fluoroscopies and may result in significant amount of extra radiation to patients, especially for prolonged treatment cases. In addition, kV projections only provide 2D information, which is insufficient for in vivo dose reconstruction. We propose real-time volumetric imaging using prior knowledge of pre-treatment 4D images and real-time 2D transit data of treatment beam and kV beam. Methods: The pre-treatment multi-snapshot volumetric images are used to simulate 2D projections of both the treatment beam and kV beam, respectively, for each treatment field defined by the control point. During radiation delivery, the transit signals acquired by the electronic portal image device (EPID) are processed for every projection and compared with pre-calculation by cross-correlation for phase matching and thus 3D snapshot identification or real-time volumetric imaging. The data processing involves taking logarithmic ratios of EPID signals with respect to the air scan to reduce modeling uncertainties in head scatter fluence and EPID response. Simulated 2D projections are also used to pre-calculate confidence levels in phase matching. Treatment beam projections that have a low confidence level either in pre-calculation or real-time acquisition will trigger kV beams so that complementary information can be exploited. In case both the treatment beam and kV beam return low confidence in phase matching, a predicted phase based on linear regression will be generated. Results: Simulation studies indicated treatment beams provide sufficient confidence in phase matching for most cases. At times of low confidence from treatment beams, kV imaging provides sufficient confidence in phase matching due to its complementary configuration. Conclusion: The proposed real-time volumetric imaging utilizes the treatment beam and triggers kV beams for complementary information when the treatment beam along does not provide sufficient

The establishment of the method of three dimension volumetric fusion of emission and transmission images for PET imaging

International Nuclear Information System (INIS)

Zhang Xiangsong; He Zuoxiang

2004-01-01

Objective: To establish the method of three dimension volumetric fusion of emission and transmission images for PET imaging. Methods: The volume data of emission and transmission images acquired with Siemens ECAT HR + PET scanner were transferred to PC computer by local area network. The PET volume data were converted into 8 bit byte type, and scaled to the range of 0-255. The data coordinates of emission and transmission images were normalized by three-dimensional coordinate conversion in the same way. The images were fused with the mode of alpha-blending. The accuracy of image fusion was confirmed by its clinical application in 13 cases. Results: The three dimension volumetric fusion of emission and transmission images clearly displayed the silhouette and anatomic configuration in chest, including chest wall, lung, heart, mediastinum, et al. Forty-eight lesions in chest in 13 cases were accurately located by the image fusion. Conclusions: The volume data of emission and transmission images acquired with Siemens ECAT HR + PET scanner have the same data coordinate. The three dimension fusion software can conveniently used for the three dimension volumetric fusion of emission and transmission images, and also can correctly locate the lesions in chest

Experimental determination of relative light conversion factors of TLD-100 for protons with energies from 2.0 to 9.0 MeV

International Nuclear Information System (INIS)

Schmidt, P.; Fellinger, J.; Huebner, K.; Henniger, J.

1985-01-01

Relative light conversion factors (RLCF) for heavy charged particles (protons, deuterons, recoils) are needed for the calculation of the neutron sensitivity of thermoluminescent (TL) detectors. Such light conversion factors can be determined experimentally. A method is represented for the experimental determination of RLCF. The described experimental facility gives the possibility of irradiation of different luminophor samples with heavy charged particles and flux determination and particle spectrometry at the same time. For the determination of RLCF the doses are needed which are applicated at the irradiation with heavy charged particles and gamma radiation, respectively, and the according detector readings at the TL evaluation. The problems arising at the dose determination are discussed. With this experimental facility the RLCF for TLD-100 for protons were determined. The relative light conversion factors determined according to the light sum method as well as the peak height method are summarizinhly represented and discussed. Furthermore a comparison of the glow curves is made after gamma and proton irradiation

Colloid Titration--A Rapid Method for the Determination of Charged Colloid.

Science.gov (United States)

Ueno, Keihei; Kina, Ken'yu

1985-01-01

"Colloid titration" is a volumetric method for determining charged polyelectrolytes in aqueous solutions. The principle of colloid titration, reagents used in the procedure, methods of endpoint detection, preparation of reagent solutions, general procedure used, results obtained, and pH profile of colloid titration are considered. (JN)

What are the potential advantages and disadvantages of volumetric CT scanning?

Science.gov (United States)

Voros, Szilard

2009-01-01

After the introduction and dissemination of 64-slice multislice computed tomography systems, cardiovascular CT has arrived at a crossroad, and different philosophies lead down different paths of technologic development. Increased number of detector rows in the z-axis led to the introduction of dynamic, volumetric scanning of the heart and allows for whole-organ imaging. Dynamic, volumetric "whole-organ" scanning significantly reduces image acquisition time; "single-beat whole-heart imaging" results in improved image quality and reduced radiation exposure and reduced contrast dose. It eliminates helical and pitch artifacts and allows for simultaneous imaging of the base and apex of the heart. Beyond coronary arterial luminal imaging, such innovations open up the opportunity for myocardial perfusion and viability imaging and coronary arterial plaque imaging. Dual-source technology with 2 x-ray tubes placed at 90-degree angles provides heart rate-independent temporal resolution and has the potential for tissue characterization on the basis of different attenuation values at different energy levels. Refined detector technology allows for improved low-contrast resolution and may be beneficial for more detailed evaluation of coronary arterial plaque composition. The clinical benefit of each of these technologies will have to be evaluated in carefully designed clinical trials and in everyday clinical practice. Such combined experience will probably show the relative benefit of each of these philosophies in different patient populations and in different clinical scenarios.

High-throughput volumetric reconstruction for 3D wheat plant architecture studies

Directory of Open Access Journals (Sweden)

Wei Fang

2016-09-01

Full Text Available For many tiller crops, the plant architecture (PA, including the plant fresh weight, plant height, number of tillers, tiller angle and stem diameter, significantly affects the grain yield. In this study, we propose a method based on volumetric reconstruction for high-throughput three-dimensional (3D wheat PA studies. The proposed methodology involves plant volumetric reconstruction from multiple images, plant model processing and phenotypic parameter estimation and analysis. This study was performed on 80 Triticum aestivum plants, and the results were analyzed. Comparing the automated measurements with manual measurements, the mean absolute percentage error (MAPE in the plant height and the plant fresh weight was 2.71% (1.08cm with an average plant height of 40.07cm and 10.06% (1.41g with an average plant fresh weight of 14.06g, respectively. The root mean square error (RMSE was 1.37cm and 1.79g for the plant height and plant fresh weight, respectively. The correlation coefficients were 0.95 and 0.96 for the plant height and plant fresh weight, respectively. Additionally, the proposed methodology, including plant reconstruction, model processing and trait extraction, required only approximately 20s on average per plant using parallel computing on a graphics processing unit (GPU, demonstrating that the methodology would be valuable for a high-throughput phenotyping platform.

Direct experimental determination of the atomic structure at internal interfaces

Energy Technology Data Exchange (ETDEWEB)

Browning, N.D. [Oak Ridge National Lab., TN (United States)]|[Illinois Univ., Chicago, IL (United States); Pennycook, S.J. [Oak Ridge National Lab., TN (United States)

1995-07-01

A crucial first step in understanding the effect that internal interfaces have on the properties of materials is the ability to determine the atomic structure at the interface. As interfaces can contain atomic disorder, dislocations, segregated impurities and interphases, sensitivity to all of these features is essential for complete experimental characterization. By combining Z-contrast imaging and electron energy loss spectroscopy (EELS) in a dedicated scanning transmission electron microscope (STEM), the ability to probe the structure, bonding and composition at interfaces with the necessary atomic resolution has been obtained. Experimental conditions can be controlled to provide, simultaneously, both incoherent imaging and spectroscopy. This enables interface structures observed in the image to be interpreted intuitively and the bonding in a specified atomic column to be probed directly by EELS. The bonding and structure information can then be correlated using bond-valence sum analysis to produce structural models. This technique is demonstrated for 25{degrees}, 36{degrees} and 67{degrees} symmetric and 45{degrees} and 25{degrees} asymmetric [001] tilt grain boundaries in SrTiO{sub 3} The structures of both types of boundary were found to contain partially occupied columns in the boundary plane. From these experimental results, a series of structural units were identified which could be combined, using continuity of gain boundary structure principles, to construct all [001] tilt boundaries in SrTiO{sub 3}. Using these models, the ability of this technique to address the issues of vacancies and dopant segregation at grain boundaries in electroceramics is discussed.

Methods to produce calibration mixtures for anesthetic gas monitors and how to perform volumetric calculations on anesthetic gases.

Science.gov (United States)

Christensen, P L; Nielsen, J; Kann, T

1992-10-01

A simple procedure for making calibration mixtures of oxygen and the anesthetic gases isoflurane, enflurane, and halothane is described. One to ten grams of the anesthetic substance is evaporated in a closed, 11,361-cc glass bottle filled with oxygen gas at atmospheric pressure. The carefully mixed gas is used to calibrate anesthetic gas monitors. By comparison of calculated and measured volumetric results it is shown that at atmospheric conditions the volumetric behavior of anesthetic gas mixtures can be described with reasonable accuracy using the ideal gas law. A procedure is described for calculating the deviation from ideal gas behavior in cases in which this is needed.

EXPERIMENTAL DETERMINATION OF LONGITUDINAL COMPONENT OF MAGNETIC FLUX IN FERROMAGNETIC WIRE OF SINGLE-CORE POWER CABLE ARMOUR

Directory of Open Access Journals (Sweden)

I.A. Kostiukov

2014-12-01

Full Text Available A problem of determination of effective longitudinal magnetic permeability of single core power cable armour is defined. A technique for experimental determination of longitudinal component of magnetic flux in armour spiral ferromagnetic wire is proposed.

The National Shipbuilding Research Program. Development of Electromagnetic Acoustic Transducers (EMATS) for Surface/Volumetric Inspection of Welds

National Research Council Canada - National Science Library

Maclauchlan, D. T; Clark, S. P; Perry, M. B; Hancock, J. W

2000-01-01

...) through General Dynamics - Electric Boat (EB) extended the EMAT technology by evaluating shear wave sensors for volumetric weld examination and included system evaluation in the shipyard, comparing the results...

3D Space Shift from CityGML LoD3-Based Multiple Building Elements to a 3D Volumetric Object

Directory of Open Access Journals (Sweden)

Shen Ying

2017-01-01

Full Text Available In contrast with photorealistic visualizations, urban landscape applications, and building information system (BIM, 3D volumetric presentations highlight specific calculations and applications of 3D building elements for 3D city planning and 3D cadastres. Knowing the precise volumetric quantities and the 3D boundary locations of 3D building spaces is a vital index which must remain constant during data processing because the values are related to space occupation, tenure, taxes, and valuation. To meet these requirements, this paper presents a five-step algorithm for performing a 3D building space shift. This algorithm is used to convert multiple building elements into a single 3D volumetric building object while maintaining the precise volume of the 3D space and without changing the 3D locations or displacing the building boundaries. As examples, this study used input data and building elements based on City Geography Markup Language (CityGML LoD3 models. This paper presents a method for 3D urban space and 3D property management with the goal of constructing a 3D volumetric object for an integral building using CityGML objects, by fusing the geometries of various building elements. The resulting objects possess true 3D geometry that can be represented by solid geometry and saved to a CityGML file for effective use in 3D urban planning and 3D cadastres.

SU-F-J-166: Volumetric Spatial Distortions Comparison for 1.5 Tesla Versus 3 Tesla MRI for Gamma Knife Radiosurgery Scans Using Frame Marker Fusion and Co-Registration Modes

International Nuclear Information System (INIS)

Neyman, G

2016-01-01

Purpose: To compare typical volumetric spatial distortions for 1.5 Tesla versus 3 Tesla MRI Gamma Knife radiosurgery scans in the frame marker fusion and co-registration frame-less modes. Methods: Quasar phantom by Modus Medical Devices Inc. with GRID image distortion software was used for measurements of volumetric distortions. 3D volumetric T1 weighted scans of the phantom were produced on 1.5 T Avanto and 3 T Skyra MRI Siemens scanners. The analysis was done two ways: for scans with localizer markers from the Leksell frame and relatively to the phantom only (simulated co-registration technique). The phantom grid contained a total of 2002 vertices or control points that were used in the assessment of volumetric geometric distortion for all scans. Results: Volumetric mean absolute spatial deviations relatively to the frame localizer markers for 1.5 and 3 Tesla machine were: 1.39 ± 0.15 and 1.63 ± 0.28 mm with max errors of 1.86 and 2.65 mm correspondingly. Mean 2D errors from the Gamma Plan were 0.3 and 1.0 mm. For simulated co-registration technique the volumetric mean absolute spatial deviations relatively to the phantom for 1.5 and 3 Tesla machine were: 0.36 ± 0.08 and 0.62 ± 0.13 mm with max errors of 0.57 and 1.22 mm correspondingly. Conclusion: Volumetric spatial distortions are lower for 1.5 Tesla versus 3 Tesla MRI machines localized with markers on frames and significantly lower for co-registration techniques with no frame localization. The results show the advantage of using co-registration technique for minimizing MRI volumetric spatial distortions which can be especially important for steep dose gradient fields typically used in Gamma Knife radiosurgery. Consultant for Elekta AB

SU-F-J-166: Volumetric Spatial Distortions Comparison for 1.5 Tesla Versus 3 Tesla MRI for Gamma Knife Radiosurgery Scans Using Frame Marker Fusion and Co-Registration Modes

Energy Technology Data Exchange (ETDEWEB)

Neyman, G [The Cleveland Clinic Foundation, Cleveland, OH (United States)

2016-06-15

Purpose: To compare typical volumetric spatial distortions for 1.5 Tesla versus 3 Tesla MRI Gamma Knife radiosurgery scans in the frame marker fusion and co-registration frame-less modes. Methods: Quasar phantom by Modus Medical Devices Inc. with GRID image distortion software was used for measurements of volumetric distortions. 3D volumetric T1 weighted scans of the phantom were produced on 1.5 T Avanto and 3 T Skyra MRI Siemens scanners. The analysis was done two ways: for scans with localizer markers from the Leksell frame and relatively to the phantom only (simulated co-registration technique). The phantom grid contained a total of 2002 vertices or control points that were used in the assessment of volumetric geometric distortion for all scans. Results: Volumetric mean absolute spatial deviations relatively to the frame localizer markers for 1.5 and 3 Tesla machine were: 1.39 ± 0.15 and 1.63 ± 0.28 mm with max errors of 1.86 and 2.65 mm correspondingly. Mean 2D errors from the Gamma Plan were 0.3 and 1.0 mm. For simulated co-registration technique the volumetric mean absolute spatial deviations relatively to the phantom for 1.5 and 3 Tesla machine were: 0.36 ± 0.08 and 0.62 ± 0.13 mm with max errors of 0.57 and 1.22 mm correspondingly. Conclusion: Volumetric spatial distortions are lower for 1.5 Tesla versus 3 Tesla MRI machines localized with markers on frames and significantly lower for co-registration techniques with no frame localization. The results show the advantage of using co-registration technique for minimizing MRI volumetric spatial distortions which can be especially important for steep dose gradient fields typically used in Gamma Knife radiosurgery. Consultant for Elekta AB.

Predicting clinical outcomes in chordoma patients receiving immunotherapy: a comparison between volumetric segmentation and RECIST

International Nuclear Information System (INIS)

Fenerty, Kathleen E.; Folio, Les R.; Patronas, Nicholas J.; Marté, Jennifer L.; Gulley, James L.; Heery, Christopher R.

2016-01-01

The Response Evaluation Criteria in Solid Tumors (RECIST) are the current standard for evaluating disease progression or therapy response in patients with solid tumors. RECIST 1.1 calls for axial, longest-diameter (or perpendicular short axis of lymph nodes) measurements of a maximum of five tumors, which limits clinicians’ ability to adequately measure disease burden, especially in patients with irregularly shaped tumors. This is especially problematic in chordoma, a disease for which RECIST does not always adequately capture disease burden because chordoma tumors are typically irregularly shaped and slow-growing. Furthermore, primary chordoma tumors tend to be adjacent to vital structures in the skull or sacrum that, when compressed, lead to significant clinical consequences. Volumetric segmentation is a newer technology that allows tumor burden to be measured in three dimensions on either MR or CT. Here, we compared the ability of RECIST measurements and tumor volumes to predict clinical outcomes in a cohort of 21 chordoma patients receiving immunotherapy. There was a significant difference in radiologic time to progression Kaplan-Meier curves between clinical outcome groups using volumetric segmentation (P = 0.012) but not RECIST (P = 0.38). In several cases, changes in volume were earlier and more sensitive reflections of clinical status. RECIST is a useful evaluation method when obvious changes are occurring in patients with chordoma. However, in many cases, RECIST does not detect small changes, and volumetric assessment was capable of detecting changes and predicting clinical outcome earlier than RECIST. Although this study was small and retrospective, we believe our results warrant further research in this area

Volumetric properties for glycine and L-serine in aqueous solutions of 1-Ethyl-3-methylimidazolium hydrogen sulfate ([Emim][HSO4]) at T = (293.15–313.15) K and ambient pressure

International Nuclear Information System (INIS)

Rafiee, Hamid Reza; Frouzesh, Farshid

2016-01-01

Highlights: • Ternary systems (amino acid + ionic liquid + H 2 O) are considered. • Volumetric properties including density, V φ , ΔV φ 0 and E φ 0 are determined. • Glycine and L-serine were amino acids and [Emim][HSO 4 ] was IL studied. • V φ values for amino acids increased with both concentration of amino acids and temperature. • Both studied amino acids act as structure maker in ternary systems. - Abstract: By using the volumetric properties, the solute–solvent interactions are studied in the ternary (glycine + 1-Ethyl-3-methylimidazolium hydrogen sulfate [Emim][HSO 4 ] + water) and (L-serine + 1-Ethyl-3-methylimidazolium hydrogen sulfate [Emim][HSO 4 ] + water) systems. For this purpose, the apparent molar volumes, V φ , are calculated from the experimental density data. To obtain limiting apparent molar volumes V φ 0 , the apparent molar volume values are fitted to the Redlich-Mayer type equation. Then the limiting apparent molar volumes of transfer, ΔV φ 0 , for studied amino acids from water to aqueous solutions of ionic liquid (IL) are calculated. The results showed that the ΔV φ 0 values are negative for both ternary systems at all temperatures. The limiting apparent molar expansibility E φ 0 values have been obtained from the first derivative of limiting apparent molar volumes with respect to temperature. The values of second derivative of limiting apparent molar volumes respect to temperature show the structure making or breaking ability of glycine and L-serine in studied IL aqueous solutions. The results indicated that glycine and L-serine act as structure maker in studied solutions. McMillan–Mayer theory is used for evaluating the interaction parameters. Also the hydration number, n H , for both amino acids in ternary solutions has been reported.

Scanners and drillers: Characterizing expert visual search through volumetric images

Science.gov (United States)

Drew, Trafton; Vo, Melissa Le-Hoa; Olwal, Alex; Jacobson, Francine; Seltzer, Steven E.; Wolfe, Jeremy M.

2013-01-01

Modern imaging methods like computed tomography (CT) generate 3-D volumes of image data. How do radiologists search through such images? Are certain strategies more efficient? Although there is a large literature devoted to understanding search in 2-D, relatively little is known about search in volumetric space. In recent years, with the ever-increasing popularity of volumetric medical imaging, this question has taken on increased importance as we try to understand, and ultimately reduce, errors in diagnostic radiology. In the current study, we asked 24 radiologists to search chest CTs for lung nodules that could indicate lung cancer. To search, radiologists scrolled up and down through a “stack” of 2-D chest CT “slices.” At each moment, we tracked eye movements in the 2-D image plane and coregistered eye position with the current slice. We used these data to create a 3-D representation of the eye movements through the image volume. Radiologists tended to follow one of two dominant search strategies: “drilling” and “scanning.” Drillers restrict eye movements to a small region of the lung while quickly scrolling through depth. Scanners move more slowly through depth and search an entire level of the lung before moving on to the next level in depth. Driller performance was superior to the scanners on a variety of metrics, including lung nodule detection rate, percentage of the lung covered, and the percentage of search errors where a nodule was never fixated. PMID:23922445

EXPERIMENTAL DETERMINATION OF DOUBLE VIBE FUNCTION PARAMETERS IN DIESEL ENGINES WITH BIODIESEL

Directory of Open Access Journals (Sweden)

Radivoje B Pešić

2010-01-01

Full Text Available A zero-dimensional, one zone model of engine cycle for steady-state regimes of engines and a simplified procedure for indicator diagrams analysis have been developed at the Laboratory for internal combustion engines, fuels and lubricants of the Faculty of Mechanical Engineering in Kragujevac. In addition to experimental research, thermodynamic modeling of working process of diesel engine with direct injection has been presented in this paper. The simplified procedure for indicator diagrams analysis has been applied, also. The basic problem, a selection of shape parameters of double Vibe function used for modeling the engine operation process, has been solved. The influence of biodiesel fuel and engine working regimes on the start of combustion, combustion duration and shape parameter of double Vibe was determined by a least square fit of experimental heat release curve.

Volumetric capnography: In the diagnostic work-up of chronic thromboembolic disease

Directory of Open Access Journals (Sweden)

Marcos Mello Moreira

2010-05-01

Full Text Available Marcos Mello Moreira1, Renato Giuseppe Giovanni Terzi1, Laura Cortellazzi2, Antonio Luis Eiras Falcão1, Heitor Moreno Junior2, Luiz Cláudio Martins2, Otavio Rizzi Coelho21Department of Surgery, 2Department of Internal Medicine, State University of Campinas, School of Medical Sciences, Campinas, Sao Paulo, BrazilAbstract: The morbidity and mortality of pulmonary embolism (PE have been found to be related to early diagnosis and appropriate treatment. The examinations used to diagnose PE are expensive and not always easily accessible. These options include noninvasive examinations, such as clinical pretests, ELISA D-dimer (DD tests, and volumetric capnography (VCap. We report the case of a patient whose diagnosis of PE was made via pulmonary arteriography. The clinical pretest revealed a moderate probability of the patient having PE, and the DD result was negative; however, the VCap associated with arterial blood gases result was positive. The patient underwent all noninvasive exams following admission to hospital and again eight months after discharge. Results gained from invasive tests were similar to those produced by image exams, highlighting the importance of VCap as an important noninvasive tool.Keywords: pulmonary embolism, pulmonary hypertension, volumetric capnography, d-dimers, pretest probability

An Improved Random Walker with Bayes Model for Volumetric Medical Image Segmentation

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Chunhua Dong

2017-01-01

Full Text Available Random walk (RW method has been widely used to segment the organ in the volumetric medical image. However, it leads to a very large-scale graph due to a number of nodes equal to a voxel number and inaccurate segmentation because of the unavailability of appropriate initial seed point setting. In addition, the classical RW algorithm was designed for a user to mark a few pixels with an arbitrary number of labels, regardless of the intensity and shape information of the organ. Hence, we propose a prior knowledge-based Bayes random walk framework to segment the volumetric medical image in a slice-by-slice manner. Our strategy is to employ the previous segmented slice to obtain the shape and intensity knowledge of the target organ for the adjacent slice. According to the prior knowledge, the object/background seed points can be dynamically updated for the adjacent slice by combining the narrow band threshold (NBT method and the organ model with a Gaussian process. Finally, a high-quality image segmentation result can be automatically achieved using Bayes RW algorithm. Comparing our method with conventional RW and state-of-the-art interactive segmentation methods, our results show an improvement in the accuracy for liver segmentation (p<0.001.

Bounding uncertainty in volumetric geometric models for terrestrial lidar observations of ecosystems.

Science.gov (United States)

Paynter, Ian; Genest, Daniel; Peri, Francesco; Schaaf, Crystal

2018-04-06

Volumetric models with known biases are shown to provide bounds for the uncertainty in estimations of volume for ecologically interesting objects, observed with a terrestrial laser scanner (TLS) instrument. Bounding cuboids, three-dimensional convex hull polygons, voxels, the Outer Hull Model and Square Based Columns (SBCs) are considered for their ability to estimate the volume of temperate and tropical trees, as well as geomorphological features such as bluffs and saltmarsh creeks. For temperate trees, supplementary geometric models are evaluated for their ability to bound the uncertainty in cylinder-based reconstructions, finding that coarser volumetric methods do not currently constrain volume meaningfully, but may be helpful with further refinement, or in hybridized models. Three-dimensional convex hull polygons consistently overestimate object volume, and SBCs consistently underestimate volume. Voxel estimations vary in their bias, due to the point density of the TLS data, and occlusion, particularly in trees. The response of the models to parametrization is analysed, observing unexpected trends in the SBC estimates for the drumlin dataset. Establishing that this result is due to the resolution of the TLS observations being insufficient to support the resolution of the geometric model, it is suggested that geometric models with predictable outcomes can also highlight data quality issues when they produce illogical results.

Complete volumetric decomposition of individual trabecular plates and rods and its morphological correlations with anisotropic elastic moduli in human trabecular bone.

Science.gov (United States)

Liu, X Sherry; Sajda, Paul; Saha, Punam K; Wehrli, Felix W; Bevill, Grant; Keaveny, Tony M; Guo, X Edward

2008-02-01

Trabecular plates and rods are important microarchitectural features in determining mechanical properties of trabecular bone. A complete volumetric decomposition of individual trabecular plates and rods was used to assess the orientation and morphology of 71 human trabecular bone samples. The ITS-based morphological analyses better characterize microarchitecture and help predict anisotropic mechanical properties of trabecular bone. Standard morphological analyses of trabecular architecture lack explicit segmentations of individual trabecular plates and rods. In this study, a complete volumetric decomposition technique was developed to segment trabecular bone microstructure into individual plates and rods. Contributions of trabecular type-associated morphological parameters to the anisotropic elastic moduli of trabecular bone were studied. Seventy-one human trabecular bone samples from the femoral neck (FN), tibia, and vertebral body (VB) were imaged using muCT or serial milling. Complete volumetric decomposition was applied to segment trabecular bone microstructure into individual plates and rods. The orientation of each individual trabecula was determined, and the axial bone volume fractions (aBV/TV), axially aligned bone volume fraction along each orthotropic axis, were correlated with the elastic moduli. The microstructural type-associated morphological parameters were derived and compared with standard morphological parameters. Their contributions to the anisotropic elastic moduli, calculated by finite element analysis (FEA), were evaluated and compared. The distribution of trabecular orientation suggested that longitudinal plates and transverse rods dominate at all three anatomic sites. aBV/TV along each axis, in general, showed a better correlation with the axial elastic modulus (r(2) = 0.95 approximately 0.99) compared with BV/TV (r(2) = 0.93 approximately 0.94). The plate-associated morphological parameters generally showed higher correlations with the

Experimental determination of the heat transfer coefficient in shell-and-tube condensers using the Wilson plot method

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Havlik Jan

2017-01-01

Full Text Available This article deals with the experimental determination of heat transfer coefficients. The calculation of heat transfer coefficients constitutes a crucial issue in design and sizing of heat exchangers. The Wilson plot method and its modifications based on measured experimental data utilization provide an appropriate tool for the analysis of convection heat transfer processes and the determination of convection coefficients in complex cases. A modification of the Wilson plot method for shell-and-tube condensers is proposed. The original Wilson plot method considers a constant value of thermal resistance on the condensation side. The heat transfer coefficient on the cooling side is determined based on the change in thermal resistance for different conditions (fluid velocity and temperature. The modification is based on the validation of the Nusselt theory for calculating the heat transfer coefficient on the condensation side. A change of thermal resistance on the condensation side is expected and the value is part of the calculation. It is possible to improve the determination accuracy of the criterion equation for calculation of the heat transfer coefficient using the proposed modification. The criterion equation proposed by this modification for the tested shell-and-tube condenser achieves good agreement with the experimental results and also with commonly used theoretical methods.

Volumetric multimodality neural network for brain tumor segmentation

Science.gov (United States)

Silvana Castillo, Laura; Alexandra Daza, Laura; Carlos Rivera, Luis; Arbeláez, Pablo

2017-11-01

Brain lesion segmentation is one of the hardest tasks to be solved in computer vision with an emphasis on the medical field. We present a convolutional neural network that produces a semantic segmentation of brain tumors, capable of processing volumetric data along with information from multiple MRI modalities at the same time. This results in the ability to learn from small training datasets and highly imbalanced data. Our method is based on DeepMedic, the state of the art in brain lesion segmentation. We develop a new architecture with more convolutional layers, organized in three parallel pathways with different input resolution, and additional fully connected layers. We tested our method over the 2015 BraTS Challenge dataset, reaching an average dice coefficient of 84%, while the standard DeepMedic implementation reached 74%.

Synthesis of Volumetric Ring Antenna Array for Terrestrial Coverage Pattern

Directory of Open Access Journals (Sweden)

Alberto Reyna

2014-01-01

Full Text Available This paper presents a synthesis of a volumetric ring antenna array for a terrestrial coverage pattern. This synthesis regards the spacing among the rings on the planes X-Y, the positions of the rings on the plane X-Z, and uniform and concentric excitations. The optimization is carried out by implementing the particle swarm optimization. The synthesis is compared with previous designs by resulting with proper performance of this geometry to provide an accurate coverage to be applied in satellite applications with a maximum reduction of the antenna hardware as well as the side lobe level reduction.

Synthesis of Volumetric Ring Antenna Array for Terrestrial Coverage Pattern

Science.gov (United States)

Reyna, Alberto; Panduro, Marco A.; Del Rio Bocio, Carlos

2014-01-01

This paper presents a synthesis of a volumetric ring antenna array for a terrestrial coverage pattern. This synthesis regards the spacing among the rings on the planes X-Y, the positions of the rings on the plane X-Z, and uniform and concentric excitations. The optimization is carried out by implementing the particle swarm optimization. The synthesis is compared with previous designs by resulting with proper performance of this geometry to provide an accurate coverage to be applied in satellite applications with a maximum reduction of the antenna hardware as well as the side lobe level reduction. PMID:24701150

Minimum pricing of alcohol versus volumetric taxation: which policy will reduce heavy consumption without adversely affecting light and moderate consumers?

Science.gov (United States)

Sharma, Anurag; Vandenberg, Brian; Hollingsworth, Bruce

2014-01-01

We estimate the effect on light, moderate and heavy consumers of alcohol from implementing a minimum unit price for alcohol (MUP) compared with a uniform volumetric tax. We analyse scanner data from a panel survey of demographically representative households (n = 885) collected over a one-year period (24 Jan 2010-22 Jan 2011) in the state of Victoria, Australia, which includes detailed records of each household's off-trade alcohol purchasing. The heaviest consumers (3% of the sample) currently purchase 20% of the total litres of alcohol (LALs), are more likely to purchase cask wine and full strength beer, and pay significantly less on average per standard drink compared to the lightest consumers (A$1.31 [95% CI 1.20-1.41] compared to $2.21 [95% CI 2.10-2.31]). Applying a MUP of A$1 per standard drink has a greater effect on reducing the mean annual volume of alcohol purchased by the heaviest consumers of wine (15.78 LALs [95% CI 14.86-16.69]) and beer (1.85 LALs [95% CI 1.64-2.05]) compared to a uniform volumetric tax (9.56 LALs [95% CI 9.10-10.01] and 0.49 LALs [95% CI 0.46-0.41], respectively). A MUP results in smaller increases in the annual cost for the heaviest consumers of wine ($393.60 [95% CI 374.19-413.00]) and beer ($108.26 [95% CI 94.76-121.75]), compared to a uniform volumetric tax ($552.46 [95% CI 530.55-574.36] and $163.92 [95% CI 152.79-175.03], respectively). Both a MUP and uniform volumetric tax have little effect on changing the annual cost of wine and beer for light and moderate consumers, and likewise little effect upon their purchasing. While both a MUP and a uniform volumetric tax have potential to reduce heavy consumption of wine and beer without adversely affecting light and moderate consumers, a MUP offers the potential to achieve greater reductions in heavy consumption at a lower overall annual cost to consumers.

A review of experimental methods for determining residual creep life

International Nuclear Information System (INIS)

Bolton, C.J.

1977-11-01

Experimental methods available for determining how much creep life remains at a particular time in the high temperature service of a component are reviewed. After a brief consideration of the limitations of stress rupture extrapolation techniques, the application of post-exposure creep testing is considered. Ways of assessing the effect of microstructural degradation on residual life are then reviewed. It is pointed out that while this type of work will be useful for certain materials, there are other materials in which 'mechanical damage' such as cavitation will be more important. Cavitation measurement techniques are therefore reviewed. The report ends with a brief consideration of the use of crack growth measurements in assessing the residual life of cracked components. (author)

Soft-tissue volumetric changes following monobloc distraction procedure: analysis using digital three-dimensional photogrammetry system (3dMD).

Science.gov (United States)

Chan, Fuan Chiang; Kawamoto, Henry K; Federico, Christina; Bradley, James P

2013-03-01

We have previously reported that monobloc advancement by distraction osteogenesis resulted in decreased morbidity and greater advancement with less relapse compared with acute monobloc advancement with bone grafting. In this study, we examine the three-dimensional (3D) volumetric soft-tissue changes in monobloc distraction.Patients with syndromic craniosynostosis who underwent monobloc distraction from 2002 to 2010 at University of California-Los Angeles Craniofacial Center were studied (n = 12). We recorded diagnosis, indications for the surgery, and volumetric changes for skeletal and soft-tissue midface structures (preoperative/postoperative [6 weeks]/follow-up [>1 year]). Computed tomography scans and a digital 3D photogrammetry system were used for image analysis.Patients ranged from 6 to 14 years of age (mean, 10.1 years) at the time of the operation (follow-up 2-11 years); mean distraction advancement was 19.4 mm (range, 14-25 mm). There was a mean increase in the 3D volumetric soft-tissue changes: 99.5 ± 4.0 cm(3) (P < 0.05) at 6 weeks and 94.9 ± 3.6 cm(3) (P < 0.05) at 1-year follow-up. When comparing soft-tissue changes at 6 weeks postoperative to 1-year follow-up, there were minimal relapse changes. The overall mean 3D skeletal change was 108.9 ± 4.2 cm. For every 1 cm of skeletal gain, there was 0.78 cm(3) of soft-tissue gain.Monobloc advancement by distraction osteogenesis using internal devices resulted in increased volumetric soft-tissue changes, which remained stable at 1 year. The positive linear correlation between soft-tissue increments and bony advancement can be incorporated during the planning of osteotomies to achieve optimum surgical outcomes with monobloc distraction.

Experimental study of the density and derived volumetric (excess, apparent, and partial molar volumes) properties of aqueous 1-propanol mixtures at temperatures from 298 K to 582 K and pressures up to 40 MPa

International Nuclear Information System (INIS)

Abdulagatov, I.M.; Azizov, N.D.

2014-01-01

Highlights: • Density of (water + 1-propanol) mixtures. • Excess molar volumes of (water + 1-propanol) mixtures. • Apparent molar volumes of (water + 1-propanol) mixtures. -- Abstract: Densities of (water + 1-propanol) mixtures have been measured over the temperature range from 298 K to 582 K and at pressures up to 40 MPa using the constant-volume piezometer immersed in a precision liquid thermostat. The measurements were made for six compositions of (0.869, 2.465, 2.531, 7.407, 14.377, and 56.348) mol · kg −1 of 1-propanol. The expanded uncertainty of the density, pressure, temperature, and concentration measurements at the 95% confidence level with a coverage factor of k = 2 is estimated to be 0.06%, 0.05%, 15 mK, and 0.015%, respectively. The derived volumetric properties such as excess (V m E ), apparent (V Φ ), and partial (V ¯ 2 ∞ ) molar volumes were calculated using the measured values of density for the mixture and for pure components (water and 1-propanol). The concentration dependences of the apparent molar volumes were extrapolated to zero concentration to yield the partial molar volumes of 1-propanol at infinite dilution (V ¯ 2 ∞ ). The temperature, pressure, and concentration dependence of density and derived properties of the mixture were studied. All experimental and derived properties (excess, apparent, and partial molar volumes) were compared with the reported data by other authors. The small and negative values of excess molar volume for the mixtures were found at all experimental temperatures, pressures, and over the entire concentration range. The excess molar volume minimum is found at concentration about 0.4 mole fraction of 1-propanol. The concentration minimum of the derived apparent molar volumes V Φ near the 2.5 mol · kg −1 (dilute mixture) was observed

Quantitative volumetric Raman imaging of three dimensional cell cultures

KAUST Repository

Kallepitis, Charalambos

2017-03-22

The ability to simultaneously image multiple biomolecules in biologically relevant three-dimensional (3D) cell culture environments would contribute greatly to the understanding of complex cellular mechanisms and cell–material interactions. Here, we present a computational framework for label-free quantitative volumetric Raman imaging (qVRI). We apply qVRI to a selection of biological systems: human pluripotent stem cells with their cardiac derivatives, monocytes and monocyte-derived macrophages in conventional cell culture systems and mesenchymal stem cells inside biomimetic hydrogels that supplied a 3D cell culture environment. We demonstrate visualization and quantification of fine details in cell shape, cytoplasm, nucleus, lipid bodies and cytoskeletal structures in 3D with unprecedented biomolecular specificity for vibrational microspectroscopy.

Quantitative volumetric Raman imaging of three dimensional cell cultures

Science.gov (United States)

Kallepitis, Charalambos; Bergholt, Mads S.; Mazo, Manuel M.; Leonardo, Vincent; Skaalure, Stacey C.; Maynard, Stephanie A.; Stevens, Molly M.

2017-03-01

The ability to simultaneously image multiple biomolecules in biologically relevant three-dimensional (3D) cell culture environments would contribute greatly to the understanding of complex cellular mechanisms and cell-material interactions. Here, we present a computational framework for label-free quantitative volumetric Raman imaging (qVRI). We apply qVRI to a selection of biological systems: human pluripotent stem cells with their cardiac derivatives, monocytes and monocyte-derived macrophages in conventional cell culture systems and mesenchymal stem cells inside biomimetic hydrogels that supplied a 3D cell culture environment. We demonstrate visualization and quantification of fine details in cell shape, cytoplasm, nucleus, lipid bodies and cytoskeletal structures in 3D with unprecedented biomolecular specificity for vibrational microspectroscopy.

Finite element analysis of volumetrically heated fluids in an axisymmetric enclosure

International Nuclear Information System (INIS)

Gartling, D.K.

1979-01-01

A general purpose finite element computer code has been used to analyze the steady state and transient response of a confined fluid that is heated volumetrically. The numerical procedure is demonstrated to be capable of resolving flow fields of considerable complexity without undue computational expense. Results are discussed for a Grashof number range (4.0 x 10 4 to 4.0 x 10 6 ) in which the flow varies from a steady, single cell configuration to a multiple cell configuration that includes a periodic interaction

Automated procedure for volumetric measurement of metastases. Estimation of tumor burden

International Nuclear Information System (INIS)

Fabel, M.; Bolte, H.

2008-01-01

Cancer is a common and increasing disease worldwide. Therapy monitoring in oncologic patient care requires accurate and reliable measurement methods for evaluation of the tumor burden. RECIST (response evaluation criteria in solid tumors) and WHO criteria are still the current standards for therapy response evaluation with inherent disadvantages due to considerable interobserver variation of the manual diameter estimations. Volumetric analysis of e.g. lung, liver and lymph node metastases, promises to be a more accurate, precise and objective method for tumor burden estimation. (orig.) [de

Volumetric properties of the (tetrahydrofuran + water) and (tetra-n-butyl ammonium bromide + water) systems: Experimental measurements and correlations

International Nuclear Information System (INIS)

Belandria, Veronica; Mohammadi, Amir H.; Richon, Dominique

2009-01-01

In this communication, we report experimental density data for the binary mixtures of (water + tetrahydrofuran) and (water + tetra-n-butyl ammonium bromide) at atmospheric pressure and various temperatures. The densities were measured using an Anton Paar TM digital vibrating-tube densimeter. For the (tetrahydrofuran + water) system, excess molar volumes have been calculated using the experimental densities and correlated using the Redlich-Kister equation. The Redlich-Kister equation parameters have been adjusted on experimental results. The partial molar volumes and partial excess molar volumes at infinite dilution have also been calculated for each component. A simple density equation was finally applied to correlate the measured density of the (tetra-n-butyl ammonium bromide + water) system.

Gamma-index method sensitivity for gauging plan delivery accuracy of volumetric modulated arc therapy.

Science.gov (United States)

Park, Jong In; Park, Jong Min; Kim, Jung-In; Park, So-Yeon; Ye, Sung-Joon

2015-12-01

The aim of this study was to investigate the sensitivity of the gamma-index method according to various gamma criteria for volumetric modulated arc therapy (VMAT). Twenty head and neck (HN) and twenty prostate VMAT plans were retrospectively selected for this study. Both global and local 2D gamma evaluations were performed with criteria of 3%/3 mm, 2%/2 mm, 1%/2 mm and 2%/1 mm. In this study, the global and local gamma-index calculated the differences in doses relative to the maximum dose and the dose at the current measurement point, respectively. Using log files acquired during delivery, the differences in parameters at every control point between the VMAT plans and the log files were acquired. The differences in dose-volumetric parameters between reconstructed VMAT plans using the log files and the original VMAT plans were calculated. The Spearman's rank correlation coefficients (rs) were calculated between the passing rates and those differences. Considerable correlations with statistical significances were observed between global 1%/2 mm, local 1%/2 mm and local 2%/1 mm and the MLC position differences (rs = -0.712, -0.628 and -0.581). The numbers of rs values with statistical significance between the passing rates and the changes in dose-volumetric parameters were largest in global 2%/2 mm (n = 16), global 2%/1 mm (n = 15) and local 2%/1 mm (n = 13) criteria. Local gamma-index method with 2%/1 mm generally showed higher sensitivity to detect deviations between a VMAT plan and the delivery of the VMAT plan. Copyright © 2015 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

Experimental Determination and Numerical Modelling of Process Induced Strains and Residual Stresses in Thick Glass/Epoxy Laminate

DEFF Research Database (Denmark)

Nielsen, Michael Wenani; Hattel, Jesper Henri; Løgstrup Andersen, Tom

2012-01-01

dependency on temperature and cure degree. Model predictions are compared to experimentally determined in-situ strains, determined using FBG sensors. It was found that both models offer good approximations of internal strain build-up. A general shortcoming is the lack of capturing rate-dependent effects...

Integral transform solution of natural convection in a square cavity with volumetric heat generation

Directory of Open Access Journals (Sweden)

C. An

2013-12-01

Full Text Available The generalized integral transform technique (GITT is employed to obtain a hybrid numerical-analytical solution of natural convection in a cavity with volumetric heat generation. The hybrid nature of this approach allows for the establishment of benchmark results in the solution of non-linear partial differential equation systems, including the coupled set of heat and fluid flow equations that govern the steady natural convection problem under consideration. Through performing the GITT, the resulting transformed ODE system is then numerically solved by making use of the subroutine DBVPFD from the IMSL Library. Therefore, numerical results under user prescribed accuracy are obtained for different values of Rayleigh numbers, and the convergence behavior of the proposed eigenfunction expansions is illustrated. Critical comparisons against solutions produced by ANSYS CFX 12.0 are then conducted, which demonstrate excellent agreement. Several sets of reference results for natural convection with volumetric heat generation in a bi-dimensional square cavity are also provided for future verification of numerical results obtained by other researchers.

Graphene and maghemite composites based supercapacitors delivering high volumetric capacitance and extraordinary cycling stability

International Nuclear Information System (INIS)

Zhang, Haitao; Zhang, Xiong; Lin, He; Wang, Kai; Sun, Xianzhong; Xu, Nansheng; Li, Chen; Ma, Yanwei

2015-01-01

Metal oxides (like MnO 2 , Fe 2 O 3 , and Co 3 O 4 , etc) based supercapacitors have disadvantages, such as low volumetric capacitance for thick-film electrodes, or short cycling life because a Faradaic process involves chemical changes of state of the reactant species. In the present work, we report that supercapacitors based on reduced graphene oxide and maghemite (γ-Fe 2 O 3 ) composites (GγM) exhibit superior performance. GγM electrodes with average electrode thickness up to ∼60 μm have a high volumetric capacitance of 230 F cm −3 , together with an outstanding electrode package density of 1.44 g cm −3 . Particularly, the GγM electrodes have excellent cycling performance of ∼90% capacitance retention over 100,000 galvanostatic charge–discharge cycles or voltage floating at 0.9 V for 300 h. No detectable change in phase and an effective inhibition of γ-Fe 2 O 3 refinement after cycle-life test are confirmed by X-ray diffraction and transmission electron microscopy

Deep learning for automatic localization, identification, and segmentation of vertebral bodies in volumetric MR images

Science.gov (United States)

Suzani, Amin; Rasoulian, Abtin; Seitel, Alexander; Fels, Sidney; Rohling, Robert N.; Abolmaesumi, Purang

2015-03-01

This paper proposes an automatic method for vertebra localization, labeling, and segmentation in multi-slice Magnetic Resonance (MR) images. Prior work in this area on MR images mostly requires user interaction while our method is fully automatic. Cubic intensity-based features are extracted from image voxels. A deep learning approach is used for simultaneous localization and identification of vertebrae. The localized points are refined by local thresholding in the region of the detected vertebral column. Thereafter, a statistical multi-vertebrae model is initialized on the localized vertebrae. An iterative Expectation Maximization technique is used to register the vertebral body of the model to the image edges and obtain a segmentation of the lumbar vertebral bodies. The method is evaluated by applying to nine volumetric MR images of the spine. The results demonstrate 100% vertebra identification and a mean surface error of below 2.8 mm for 3D segmentation. Computation time is less than three minutes per high-resolution volumetric image.

Experimental determination of the unattached radon daughter fraction and dust size distribution in some Canadian uranium mines

International Nuclear Information System (INIS)

Bigu, J.; Kirk, J.

1982-01-01

The unattached radon daughter fraction has been experimentally determined in some Canadian uranium mines. Two experimental methods have been used, the wire screen method and a diffusion sampler based on Mercer's theory of diffusional deposition on parallel circular plates. Experiments were conducted in 'non-diesel' and 'diesel' areas of the mines, i.e. locations where mining was done with diesel machinery. Unattached fractions ranged from about 2-8 per cent for non-diesel area. For diesel areas the unattached fraction was substantially lower, less than about one per cent. The aerosol concentration in the range 0.0015 - 0.13 μm was measured with a condensation nuclei counter. Dust concentration was determined with conventional samplers. Particle size distribution in the respirable range was determined with a fine particle spectrometer in conjunction with eriometric techniques

Conformal Pad-Printing Electrically Conductive Composites onto Thermoplastic Hemispheres: Toward Sustainable Fabrication of 3-Cents Volumetric Electrically Small Antennas.

Science.gov (United States)

Wu, Haoyi; Chiang, Sum Wai; Yang, Cheng; Lin, Ziyin; Liu, Jingping; Moon, Kyoung-Sik; Kang, Feiyu; Li, Bo; Wong, Ching Ping

2015-01-01

Electrically small antennas (ESAs) are becoming one of the key components in the compact wireless devices for telecommunications, defence, and aerospace systems, especially for the spherical one whose geometric layout is more closely approaching Chu's limit, thus yielding significant bandwidth improvements relative to the linear and planar counterparts. Yet broad applications of the volumetric ESAs are still hindered since the low cost fabrication has remained a tremendous challenge. Here we report a state-of-the-art technology to transfer electrically conductive composites (ECCs) from a planar mould to a volumetric thermoplastic substrate by using pad-printing technology without pattern distortion, benefit from the excellent properties of the ECCs as well as the printing-calibration method that we developed. The antenna samples prepared in this way meet the stringent requirement of an ESA (ka is as low as 0.32 and the antenna efficiency is as high as 57%), suggesting that volumetric electronic components i.e. the antennas can be produced in such a simple, green, and cost-effective way. This work can be of interest for the development of studies on green and high performance wireless communication devices.

Hybrid system for in vivo real-time planar fluorescence and volumetric optoacoustic imaging

Science.gov (United States)

Chen, Zhenyue; Deán-Ben, Xosé Luís.; Gottschalk, Sven; Razansky, Daniel

2018-02-01

Fluorescence imaging is widely employed in all fields of cell and molecular biology due to its high sensitivity, high contrast and ease of implementation. However, the low spatial resolution and lack of depth information, especially in strongly-scattering samples, restrict its applicability for deep-tissue imaging applications. On the other hand, optoacoustic imaging is known to deliver a unique set of capabilities such as high spatial and temporal resolution in three dimensions, deep penetration and spectrally-enriched imaging contrast. Since fluorescent substances can generate contrast in both modalities, simultaneous fluorescence and optoacoustic readings can provide new capabilities for functional and molecular imaging of living organisms. Optoacoustic images can further serve as valuable anatomical references based on endogenous hemoglobin contrast. Herein, we propose a hybrid system for in vivo real-time planar fluorescence and volumetric optoacoustic tomography, both operating in reflection mode, which synergistically combines the advantages of stand-alone systems. Validation of the spatial resolution and sensitivity of the system were first carried out in tissue mimicking phantoms while in vivo imaging was further demonstrated by tracking perfusion of an optical contrast agent in a mouse brain in the hybrid imaging mode. Experimental results show that the proposed system effectively exploits the contrast mechanisms of both imaging modalities, making it especially useful for accurate monitoring of fluorescence-based signal dynamics in highly scattering samples.

Medical students' cognitive load in volumetric image interpretation : Insights from human-computer interaction and eye movements

NARCIS (Netherlands)

Stuijfzand, Bobby G.; Van Der Schaaf, Marieke F.; Kirschner, Femke C.; Ravesloot, Cécile J.; Van Der Gijp, Anouk; Vincken, Koen L.

2016-01-01

Medical image interpretation is moving from using 2D- to volumetric images, thereby changing the cognitive and perceptual processes involved. This is expected to affect medical students' experienced cognitive load, while learning image interpretation skills. With two studies this explorative

Is the thermal-spike model consistent with experimentally determined electron temperature?

International Nuclear Information System (INIS)

Ajryan, Eh.A.; Fedorov, A.V.; Kostenko, B.F.

2000-01-01

Carbon K-Auger electron spectra from amorphous carbon foils induced by fast heavy ions are theoretically investigated. The high-energy tail of the Auger structure showing a clear projectile charge dependence is analyzed within the thermal-spike model framework as well as in the frame of another model taking into account some kinetic features of the process. A poor comparison results between theoretically and experimentally determined temperatures are suggested to be due to an improper account of double electron excitations or due to shake-up processes which leave the system in a more energetic initial state than a statically screened core hole

Considerations on the analytic control of sulphide tracks in metal uranium

International Nuclear Information System (INIS)

Fernandez Cellini, R.; Gasco Sanchez, C.

1956-01-01

Volumetric and colorimetric determinations of sulphur (sulphide) in uranium have been carried out by acid treatment and evaluation of SH 2 . According to the experimental results a discussion of both methods has been made. (Author)

A hand-held row-column addressed CMUT probe with integrated electronics for volumetric imaging

DEFF Research Database (Denmark)

Engholm, Mathias; Christiansen, Thomas Lehrmann; Beers, Christopher

2015-01-01

A 3 MHz, λ / 2-pitch 62+62 channel row-column addressed 2-D CMUT array designed to be mounted in a probe handle and connected to a commercial BK Medical scanner for real-time volumetric imaging is presented. It is mounted and wire-bonded on a flexible PCB, which is connected to two rigid PCBs...

Experimental 3-D Vector Velocity Estimation with Row-Column Addressed Arrays

DEFF Research Database (Denmark)

Holbek, Simon; Stuart, Matthias Bo; Jensen, Jørgen Arendt

2016-01-01

Experimental 3-D vector flow estimates obtained with a 62+62 2-D row-column (RC) array with integrated apodization are presented. A transverse oscillation (TO) velocity estimator is implemented on a 3.0 MHz RC array, to yield realtime 3-D vector flow in a cross-sectional scan plane at 750 frames...... per second. The method is validated in a straight-vessel phantom (Ø = 8 mm) connected to a flow pump capable of generating timevarying carotid waveforms. The out-of-plane velocity component perpendicular to the cross section of the vessel and the crosssectional area is used to estimate volumetric flow...

The roles of time and displacement in velocity-dependent volumetric strain of fault zones

Science.gov (United States)

Beeler, N.M.; Tullis, T.E.

1997-01-01

The relationship between measured friction??A and volumetric strain during frictional sliding was determined using a rate and state variable dependent friction constitutive equation, a common work balance relating friction and volume change, and two types of experimental faults: initially bare surfaces of Westerly granite and rock surfaces separated by a 1 mm layer of derivative of fault normal displacement with respect shear displacement, d??n ld??s. An implication of this relationship is that the rate dependence of d??n ld??s contributes to the rate dependence of ??A. Experiments show changes in sliding velocity lead to changes in both fault strength and volume. Analysis of data with the rate and state equations combined with the work balance relationship preclude the conventional interpretation of the direct effect in the rate and state variable constitutive equations. Consideration of a model bare surface fault consisting of an undeformable indentor sliding on a deformable surface reveals a serious flaw in the work balance relationship if volume change is time-dependent. For the model, at zero slip rate indentation creep under the normal load leads to time-dependent strengthening of the fault surface but, according to the work balance relationship, no work is done because compaction or dilatancy can only be induced by shearing. Additional tests on initially bare surfaces and gouges show that fault normal strain in experiments is time-dependent, consistent with the model. This time-dependent fault normal strain, which is not accounted for in the work balance relationship, explains the inconsistency between the constitutive equations and the work balance. For initially bare surface faults, all rate dependence of volume change is due to time dependence. Similar results are found for gouge. We conclude that ??A reflects the frictional resistance that results in shear heating, and no correction needs to be made for the volume changes. The result that time

Volumetric formulation for a class of kinetic models with energy conservation.

Science.gov (United States)

Sbragaglia, M; Sugiyama, K

2010-10-01

We analyze a volumetric formulation of lattice Boltzmann for compressible thermal fluid flows. The velocity set is chosen with the desired accuracy, based on the Gauss-Hermite quadrature procedure, and tested against controlled problems in bounded and unbounded fluids. The method allows the simulation of thermohydrodyamical problems without the need to preserve the exact space-filling nature of the velocity set, but still ensuring the exact conservation laws for density, momentum, and energy. Issues related to boundary condition problems and improvements based on grid refinement are also investigated.

A new method for the experimental determination of three-phase relative permeabilities

International Nuclear Information System (INIS)

Perez Carrillo, Edgar Ricardo; Jose Francisco Zapata Arango; Santos Santos, Nicolas

2008-01-01

Petroleum reservoirs under primary, secondary or tertiary recovery processes usually experience simultaneous flow of three fluids phases (oil, water and gas). Reports on some mathematical models for calculating three-phase relative permeability are available in the Literature. Nevertheless, many of these models were designed based on certain experimental conditions and reservoir rocks and fluids. Therefore, special care has to be taken when applying them to specific reservoirs. At the laboratory level, three-phase relative permeability can be calculated using experimental unsteady-state or steady state methodologies. This paper proposes an unsteady-state methodology to evaluate three-phase relative permeability using the equipment available at the petrophysical analysis Laboratory of the Instituto Colombiano del Petroleo (ICP) of Ecopetrol S.A. Improvements to the equipment were effected in order to achieve accuracy in the unsteady-state measurement of three-phase relative permeability. The target of improvements was directed toward to the attainment of two objectives:1) the modification of the equipment to obtain more reliable experimental data and 2) the appropriate interpretation of the data obtained. Special attention was given to the differential pressure and uncertainty measurement in the determination of fluid saturation in the rock samples. Three experiments for three-phase relative permeability were conducted using a sample A and reservoir rock from the Colombian Foothills. Fluid tests included the utilization of synthetic brine, mineral oil, reservoir crude oil and nitrogen. Two runs were conducted at the laboratory conditions while one run was conducted at reservoir conditions. Experimental results of these tests were compared using 16 mathematical models of three-phase relative permeability. For the three-phase relative permeability to oil, the best correlations between experimental data and tests using Blunt, Hustad Hasen, and Baker's models were

Optimization approaches to volumetric modulated arc therapy planning

Energy Technology Data Exchange (ETDEWEB)

Unkelbach, Jan, E-mail: junkelbach@mgh.harvard.edu; Bortfeld, Thomas; Craft, David [Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114 (United States); Alber, Markus [Department of Medical Physics and Department of Radiation Oncology, Aarhus University Hospital, Aarhus C DK-8000 (Denmark); Bangert, Mark [Department of Medical Physics in Radiation Oncology, German Cancer Research Center, Heidelberg D-69120 (Germany); Bokrantz, Rasmus [RaySearch Laboratories, Stockholm SE-111 34 (Sweden); Chen, Danny [Department of Computer Science and Engineering, University of Notre Dame, Notre Dame, Indiana 46556 (United States); Li, Ruijiang; Xing, Lei [Department of Radiation Oncology, Stanford University, Stanford, California 94305 (United States); Men, Chunhua [Department of Research, Elekta, Maryland Heights, Missouri 63043 (United States); Nill, Simeon [Joint Department of Physics at The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, London SM2 5NG (United Kingdom); Papp, Dávid [Department of Mathematics, North Carolina State University, Raleigh, North Carolina 27695 (United States); Romeijn, Edwin [H. Milton Stewart School of Industrial and Systems Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States); Salari, Ehsan [Department of Industrial and Manufacturing Engineering, Wichita State University, Wichita, Kansas 67260 (United States)

2015-03-15

Volumetric modulated arc therapy (VMAT) has found widespread clinical application in recent years. A large number of treatment planning studies have evaluated the potential for VMAT for different disease sites based on the currently available commercial implementations of VMAT planning. In contrast, literature on the underlying mathematical optimization methods used in treatment planning is scarce. VMAT planning represents a challenging large scale optimization problem. In contrast to fluence map optimization in intensity-modulated radiotherapy planning for static beams, VMAT planning represents a nonconvex optimization problem. In this paper, the authors review the state-of-the-art in VMAT planning from an algorithmic perspective. Different approaches to VMAT optimization, including arc sequencing methods, extensions of direct aperture optimization, and direct optimization of leaf trajectories are reviewed. Their advantages and limitations are outlined and recommendations for improvements are discussed.

Bayesian inference of the heat transfer properties of a wall using experimental data

KAUST Repository

Iglesias, Marco

2016-01-06

A hierarchical Bayesian inference method is developed to estimate the thermal resistance and volumetric heat capacity of a wall. We apply our methodology to a real case study where measurements are recorded each minute from two temperature probes and two heat flux sensors placed on both sides of a solid brick wall along a period of almost five days. We model the heat transfer through the wall by means of the one-dimensional heat equation with Dirichlet boundary conditions. The initial/boundary conditions for the temperature are approximated by piecewise linear functions. We assume that temperature and heat flux measurements have independent Gaussian noise and derive the joint likelihood of the wall parameters and the initial/boundary conditions. Under the model assumptions, the boundary conditions are marginalized analytically from the joint likelihood. ApproximatedGaussian posterior distributions for the wall parameters and the initial condition parameter are obtained using the Laplace method, after incorporating the available prior information. The information gain is estimated under different experimental setups, to determine the best allocation of resources.

Volumetric quantification of bone-implant contact using micro-computed tomography analysis based on region-based segmentation.

Science.gov (United States)

Kang, Sung-Won; Lee, Woo-Jin; Choi, Soon-Chul; Lee, Sam-Sun; Heo, Min-Suk; Huh, Kyung-Hoe; Kim, Tae-Il; Yi, Won-Jin

2015-03-01

We have developed a new method of segmenting the areas of absorbable implants and bone using region-based segmentation of micro-computed tomography (micro-CT) images, which allowed us to quantify volumetric bone-implant contact (VBIC) and volumetric absorption (VA). The simple threshold technique generally used in micro-CT analysis cannot be used to segment the areas of absorbable implants and bone. Instead, a region-based segmentation method, a region-labeling method, and subsequent morphological operations were successively applied to micro-CT images. The three-dimensional VBIC and VA of the absorbable implant were then calculated over the entire volume of the implant. Two-dimensional (2D) bone-implant contact (BIC) and bone area (BA) were also measured based on the conventional histomorphometric method. VA and VBIC increased significantly with as the healing period increased (pimplants using micro-CT analysis using a region-based segmentation method.

On the use of volumetric strain meters to infer additional characteristics of short-period seismic radiation

Science.gov (United States)

Borcherdt, R.D.; Johnston, M.J.S.; Glassmoyer, G.

1989-01-01

Volumetric strain meters (Sacks-Evertson design) are installed at 15 sites along the San Andreas fault system, to monitor long-term strain changes for earthquake prediction. Deployment of portable broadband, high-resolution digital recorders (GEOS) at several of the sites extends the detection band for volumetric strain to periods shorter than 5 ?? 10-2 sec and permits the simultaneous observation of seismic radiation fields using conventional short-period pendulum seismometers. Recordings of local and regional earthquakes indicate that dilatometers respond to P energy but not direct shear energy and that straingrams can be used to resolve superimposed reflect P and S waves for inference of wave characteristics not permitted by either sensor alone. Simultaneous measurements of incident P- and S-wave amplitudes are used to introduce a technique for single-station estimates of wave field inhomogeneity, free-surface reflection coefficients and local material P velocity. -from Authors

Considerations on the analytic control of sulphide tracks in metal uranium; Consideraciones osbre el control analitico de trazas de azufre (sulfuro) en uranio metal

Energy Technology Data Exchange (ETDEWEB)

Fernandez Cellini, R; Gasco Sanchez, C

1956-07-01

Volumetric and colorimetric determinations of sulphur (sulphide) in uranium have been carried out by acid treatment and evaluation of SH{sub 2}. According to the experimental results a discussion of both methods has been made. (Author)

EXPERIMENTAL DETERMINATION OF THE HYDROGEN CONCENTRATION IN THE BATTERY BOXES OF THE PASSENGER CARS

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G. S. Ighnatov

2010-06-01

Full Text Available In the work the experimental determination of the hydrogen concentration in accumulator boxes of the coach in a charging mode of nickel-cadmium batteries in operating conditions (stop and operation is presented. The comparison of the obtained characteristics at different environmental and operating conditions as well as the corresponding conclusions are made.

Automated detection and volumetric segmentation of the spleen in CT scans; Automatische Detektion und volumetrische Segmentierung der Milz in CT-Untersuchungen

Energy Technology Data Exchange (ETDEWEB)

Hammon, M.; Dankerl, P.; Janka, R.; Uder, M.; Cavallaro, A. [Universitaetsklinikum Erlangen (Germany). Radiologisches Inst.; Kramer, M.; Seifert, S.; Tsymbal, A.; Costa, M.J. [Siemens AG, Erlangen (Germany). Corporate Technology

2012-08-15

To introduce automated detection and volumetric segmentation of the spleen in spiral CT scans with the THESEUS-MEDICO software. The consistency between automated volumetry (aV), estimated volume determination (eV) and manual volume segmentation (mV) was evaluated. Retrospective evaluation of the CAD system based on methods like ''marginal space learning'' and ''boosting algorithms''. 3 consecutive spiral CT scans (thoraco-abdominal; portal-venous contrast agent phase; 1 or 5 mm slice thickness) of 15 consecutive lymphoma patients were included. The eV: 30 cm{sup 3} + 0.58 (width x length x thickness of the spleen) and the mV as the reference standard were determined by an experienced radiologist. The aV could be performed in all CT scans within 15.2 ({+-} 2.4) seconds. The average splenic volume measured by aV was 268.21 {+-} 114.67 cm{sup 3} compared to 281.58 {+-} 130.21 cm{sup 3} in mV and 268.93 {+-} 104.60 cm{sup 3} in eV. The correlation coefficient was 0.99 (coefficient of determination (R{sup 2}) = 0.98) for aV and mV, 0.91 (R{sup 2} = 0.83) for mV and eV and 0.91 (R{sup 2} = 0.82) for aV and eV. There was an almost perfect correlation of the changes in splenic volume measured with the new aV and mV (0.92; R{sup 2} = 0.84), mV and eV (0.95; R{sup 2} = 0.91) and aV and eV (0.83; R{sup 2} = 0.69) between two time points. The automated detection and volumetric segmentation software rapidly provides an accurate measurement of the splenic volume in CT scans. Knowledge about splenic volume and its change between two examinations provides valuable clinical information without effort for the radiologist. (orig.)