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Sample records for double precipitation volumetric

  1. Adsorption indicators in double precipitation volumetric. II. Use of radioactive indicators; Indicadores de adsorcion en volumetrias de doble precipitacion II. Empleo de indicadores radiactivos

    Energy Technology Data Exchange (ETDEWEB)

    Carnicero Tejerina, M. I.

    1961-07-01

    {sup 1}31I-fluorescein and {sup 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.

  2. Elucidating the DEP phenomena using a volumetric polarization approach with consideration of the electric double layer.

    Science.gov (United States)

    Zhao, Yu; Brcka, Jozef; Faguet, Jacques; Zhang, Guigen

    2017-03-01

    Dielectrophoretic (DEP) phenomena have been explored to great success for various applications like particle sorting and separation. To elucidate the underlying mechanism and quantify the DEP force experienced by particles, the point-dipole and Maxwell Stress Tensor (MST) methods are commonly used. However, both methods exhibit their own limitations. For example, the point-dipole method is unable to fully capture the essence of particle-particle interactions and the MST method is not suitable for particles of non-homogeneous property. Moreover, both methods fare poorly when it comes to explaining DEP phenomena such as the dependence of crossover frequency on medium conductivity. To address these limitations, the authors have developed a new method, termed volumetric-integration method, with the aid of computational implementation, to reexamine the DEP phenomena, elucidate the governing mechanism, and quantify the DEP force. The effect of an electric double layer (EDL) on particles' crossover behavior is dealt with through consideration of the EDL structure along with surface ionic/molecular adsorption, unlike in other methods, where the EDL is accounted for through simply assigning a surface conductance value to the particles. For validation, by comparing with literature experimental data, the authors show that the new method can quantify the DEP force on not only homogeneous particles but also non-homogeneous ones, and predict particle-particle interactions fairly accurately. Moreover, the authors also show that the predicted dependence of crossover frequency on medium conductivity and particle size agrees very well with experimental measurements.

  3. Comparison of hybrid volumetric modulated arc therapy (VMAT technique and double arc VMAT technique in the treatment of prostate cancer

    Directory of Open Access Journals (Sweden)

    Amaloo Christopher

    2015-09-01

    Full Text Available Background. Volumetric modulated arc therapy (VMAT has quickly become accepted as standard of care for the treatment of prostate cancer based on studies showing it is able to provide faster delivery with adequate target coverage and reduced monitor units while maintaining organ at risk (OAR sparing. This study aims to demonstrate the potential to increase dose conformality with increased planner control and OAR sparing using a hybrid treatment technique compared to VMAT.

  4. Multi-model projection of July-August climate extreme changes over China under CO2 doubling. Part I: Precipitation

    Science.gov (United States)

    Li, Hongmei; Feng, Lei; Zhou, Tianjun

    2011-03-01

    Potential changes in precipitation extremes in July-August over China in response to CO2 doubling are analyzed based on the output of 24 coupled climate models from the Twentieth-Century Climate in Coupled Models (20C3M) experiment and the 1% per year CO2 increase experiment (to doubling) (1pctto2x) of phase 3 of the Coupled Model Inter-comparison Project (CMIP3). Evaluation of the models' performance in simulating the mean state shows that the majority of models fairly reproduce the broad spatial pattern of observed precipitation. However, all the models underestimate extreme precipitation by ˜50%. The spread among the models over the Tibetan Plateau is ˜2-3 times larger than that over the other areas. Models with higher resolution generally perform better than those with lower resolutions in terms of spatial pattern and precipitation amount. Under the 1pctto2x scenario, the ratio between the absolute value of MME extreme precipitation change and model spread is larger than that of total precipitation, indicating a relatively robust change of extremes. The change of extreme precipitation is more homogeneous than the total precipitation. Analysis on the output of Geophysical Fluid Dynamics Laboratory coupled climate model version 2.1 (GFDL-CM2.1) indicates that the spatially consistent increase of surface temperature and water vapor content contribute to the large increase of extreme precipitation over contiguous China, which follows the Clausius-Clapeyron relationship. Whereas, the meridionally tri-polar pattern of mean precipitation change over eastern China is dominated by the change of water vapor convergence, which is determined by the response of monsoon circulation to global warming.

  5. Formation of crystalline Zn-Al layered double hydroxide precipitates on γ-alumina: the role of mineral dissolution.

    Science.gov (United States)

    Li, Wei; Livi, Kenneth J T; Xu, Wenqian; Siebecker, Matthew G; Wang, Yujun; Phillips, Brian L; Sparks, Donald L

    2012-11-06

    To better understand the sequestration of toxic metals such as nickel (Ni), zinc (Zn), and cobalt (Co) as layered double hydroxide (LDH) phases in soils, we systematically examined the presence of Al and the role of mineral dissolution during Zn sorption/precipitation on γ-Al(2)O(3) (γ-alumina) at pH 7.5 using extended X-ray absorption fine structure spectroscopy (EXAFS), high-resolution transmission electron microscopy (HR-TEM), synchrotron-radiation powder X-ray diffraction (SR-XRD), and (27)Al solid-state NMR. The EXAFS analysis indicates the formation of Zn-Al LDH precipitates at Zn concentration ≥0.4 mM, and both HR-TEM and SR-XRD reveal that these precipitates are crystalline. These precipitates yield a small shoulder at δ(Al-27) = +12.5 ppm in the (27)Al solid-state NMR spectra, consistent with the mixed octahedral Al/Zn chemical environment in typical Zn-Al LDHs. The NMR analysis provides direct evidence for the existence of Al in the precipitates and the migration from the dissolution of γ-alumina substrate. To further address this issue, we compared the Zn sorption mechanism on a series of Al (hydr)oxides with similar chemical composition but differing dissolubility using EXAFS and TEM. These results suggest that, under the same experimental conditions, Zn-Al LDH precipitates formed on γ-alumina and corundum but not on less soluble minerals such as bayerite, boehmite, and gibbsite, which point outs that substrate mineral surface dissolution plays an important role in the formation of Zn-Al LDH precipitates.

  6. Study on Volumetric Moisture Content of Soil Shallow Landslide during Precipitation Process%降雨过程中土质浅层滑体体积含水量变化研究

    Institute of Scientific and Technical Information of China (English)

    李凤琴

    2012-01-01

    Precipitation is one of the main inducing factors to landslide geological hazard, especially for the soil landslide. During the last rainfall process, the shallow part of the soil landslide will he saturated immediately and the temporary saturated zone is formed, which would lead the matric suction of the shallow landslide body reduction and slipping. While, the volumetric moisture content is the main index reflecting the variation of temporary saturated zone.Taking the participation-induced soil shallow landslide as an example in this paper, the temporary saturated zone of shallow landslide body was simulated by the Geo-slope software during 6d last rainfall. Meanwhile, the 4 points' volumetric moisture contents are analyzed from the back of the landslide to the front, which are near the slope surface and their depths are less than 5m, and the landslide stabilities are calculated during 6 days last rainfall. At last, the changing model of volumetric moisture content in soil landslide is put forward when the shallow sliding occurred during the continuous precipitation process.%降雨是滑坡地质灾害的主要诱发因素之一,尤其是对于土质滑坡,连续的降雨能够使得土质滑坡浅表层滑体迅速饱和形成暂态饱和区,从而导致浅表层土质滑体的基质吸力降低,引起浅层滑动,而反映土体中暂态饱和区变化的主要指标为士体体积含水量.该文选取某一降雨诱发型土体滑坡为例,采用Geo-slope软件模拟连续降雨6d条件下土质浅层滑体内的暂态饱和区变化情况,并分析由滑坡后缘至前缘4个靠近地表(深度小于5m)点的体积含水量变化趋势以及连续6d降雨过程中浅层滑体的稳定性变化趋势,提出了降雨人渗过程中土质滑坡发生浅层滑动的体积含水量变化模式.

  7. Multi-model Projection of July-August Climate Extreme Changes over China under CO2 Doubling. Part Ⅰ:Precipitation

    Institute of Scientific and Technical Information of China (English)

    LI Hongmei; FENG Lei; ZHOU Tianjun

    2011-01-01

    Potential changes in precipitation extremes in July-August over China in response to CO2 doubling are analyzed based on the output of 24 coupled climate models from the Twentieth-Century Climate in Coupled Models (20C3M) experiment and the 1% per year CO2 increase experiment (to doubling) (lpctto2x) of phase 3 of the Coupled Model Inter-comparison Project (CMIP3). Evaluation of the models' performance in simulating the mean state shows that the majority of models fairly reproduce the broad spatial pattern of observed precipitation. However, all the models underestimate extreme precipitation by ~50%. The spread among the models over the Tibetan Plateau is ~2-3 times larger than that over the other areas.Models with higher resolution generally perform better than those with lower resolutions in terms of spatial pattern and precipitation amount. Under the lpctto2x scenario, the ratio between the absolute value of MME extreme precipitation change and model spread is larger than that of total precipitation, indicating a relatively robust change of extremes. The change of extreme precipitation is more homogeneous than the total precipitation. Analysis on the output of Geophysical Fluid Dynamics Laboratory coupled climate model version 2.1 (GFDL-CM2.1) indicates that the spatially consistent increase of surface temperature and water vapor content contribute to the large increase of extreme precipitation over contiguous China,which follows the Clausius-Clapeyron relationship. Whereas, the meridionally tri-polar pattern of mean precipitation change over eastern China is dominated by the change of water vapor convergence, which is determined by the response of monsoon circulation to global warming.

  8. A model intercomparison of the tropical precipitation response to a CO2 doubling in aquaplanet simulations

    Science.gov (United States)

    Seo, Jeongbin; Kang, Sarah M.; Merlis, Timothy M.

    2017-01-01

    In the present-day climate, the mean Intertropical Convergence Zone (ITCZ) is north of the equator. We investigate changes in the ITCZ latitude under global warming, using multiple atmospheric models coupled to an aquaplanet slab ocean. The reference climate, with a warmer north from prescribed ocean heating, is perturbed by doubling CO2. Most models exhibit a northward ITCZ shift, but the shift cannot be accounted for by the response of energy flux equator where the atmospheric energy transport (FA) vanishes. The energetics of the simulated circulation shifts are subtle: changes in the efficiency with which the Hadley circulation transports energy, the total gross moist stability (Δm), dominate over mass flux changes in determining δFA. Even when δFA ≈ 0, the ITCZ can shift significantly due to changes in Δm, which have often been neglected previously. The dependence of ITCZ responses on δΔm calls for improved understanding of the physics determining the tropical Δm.

  9. Laser Based 3D Volumetric Display System

    Science.gov (United States)

    1993-03-01

    Literature, Costa Mesa, CA July 1983. 3. "A Real Time Autostereoscopic Multiplanar 3D Display System", Rodney Don Williams, Felix Garcia, Jr., Texas...8217 .- NUMBERS LASER BASED 3D VOLUMETRIC DISPLAY SYSTEM PR: CD13 0. AUTHOR(S) PE: N/AWIU: DN303151 P. Soltan, J. Trias, W. Robinson, W. Dahlke 7...laser generated 3D volumetric images on a rotating double helix, (where the 3D displays are computer controlled for group viewing with the naked eye

  10. Volumetric Virtual Environments

    Institute of Scientific and Technical Information of China (English)

    HE Taosong

    2000-01-01

    Driven by fast development of both virtual reality and volume visualization, we discuss some critical techniques towards building a volumetric VR system, specifically the modeling, rendering, and manipulations of a volumetric scene.Techniques such as voxel-based object simplification, accelerated volume rendering,fast stereo volume rendering, and volumetric "collision detection" are introduced and improved, with the idea of demonstrating the possibilities and potential benefits of incorporating volumetric models into VR systems.

  11. Tundra in the rain: differential vegetation responses to three years of experimentally doubled summer precipitation in Siberian shrub and Swedish bog tundra.

    Science.gov (United States)

    Keuper, Frida; Parmentier, Frans-Jan W; Blok, Daan; van Bodegom, Peter M; Dorrepaal, Ellen; van Hal, Jurgen R; van Logtestijn, Richard S P; Aerts, Rien

    2012-01-01

    Precipitation amounts and patterns at high latitude sites have been predicted to change as a result of global climatic changes. We addressed vegetation responses to three years of experimentally increased summer precipitation in two previously unaddressed tundra types: Betula nana-dominated shrub tundra (northeast Siberia) and a dry Sphagnum fuscum-dominated bog (northern Sweden). Positive responses to approximately doubled ambient precipitation (an increase of 200 mm year(-1)) were observed at the Siberian site, for B. nana (30 % larger length increments), Salix pulchra (leaf size and length increments) and Arctagrostis latifolia (leaf size and specific leaf area), but none were observed at the Swedish site. Total biomass production did not increase at either of the study sites. This study corroborates studies in other tundra vegetation types and shows that despite regional differences at the plant level, total tundra plant productivity is, at least at the short or medium term, largely irresponsive to experimentally increased summer precipitation.

  12. Precipitation Sensitivity to the Mean Radius of Drop Spectra: Comparison of Single- and Double-Moment Bulk Microphysical Schemes

    Directory of Open Access Journals (Sweden)

    Nemanja Kovačević

    2015-04-01

    Full Text Available In this study, two bulk microphysical schemes were compared across mean radius values of the entire drop spectra. A cloud-resolving mesoscale model was used to analyze surface precipitation characteristics. The model included the following microphysical categories: water vapour, cloud droplets, raindrops, ice crystals, snow, graupel, frozen raindrops and hail. Two bulk schemes were used: a single-moment scheme in which the mean radius was specified as a parameter and a double-moment scheme in which the mean radius of drops was calculated diagnostically with a fixed value for the cloud droplet number concentration. Experiments were conducted out for three values of the mean radius (in the single-moment scheme and two cloud droplet number concentrations (in the double-moment scheme. There were large differences in the surface precipitation for the two schemes, the simulated precipitation generated by the double-moment scheme had a higher sensitivity. The single-moment scheme generated an unrealistic collection rate of cloud droplets by raindrops and hail as well as unrealistic evaporation of rain and melting of solid hydrometeors; these processes led to inaccurate timing and amounts of surface precipitation.

  13. Synthesis of layered double hydroxides containing Mg2+, Zn2+, Ca2+ and Al3+ layer cations by co-precipitation methods-A review

    Science.gov (United States)

    Theiss, Frederick L.; Ayoko, Godwin A.; Frost, Ray L.

    2016-10-01

    Co-precipitation is a common method for the preparation of layered double hydroxides (LDHs) and related materials. This review article is aimed at providing newcomers to the field with some examples of the types of co-precipitation reactions that have been reported previously and to briefly investigate some of the properties of the products of these reactions. Due to the sheer volume of literature on the subject, the authors have had to limit this article to the synthesis of Mg/Al, Zn/Al and Ca/Al LDHs by co-precipitation and directly related methods. LDHs have been synthesised from various reagents including metal salts, oxides and hydroxides. Co-precipitation is also useful for the direct synthesis of LDHs with a wide range of interlayer anions and various bases have been successfully employed to prepare LDHs. Examples of other synthesis techniques including the urea method, hydrothermal synthesis and various mechanochemical methods that are undoubtedly related to co-precipitation have also been included in this review. The effect of post synthesis hydrothermal has also been summarised.

  14. Volumetric composition of nanocomposites

    DEFF Research Database (Denmark)

    Madsen, Bo; Lilholt, Hans; Mannila, Juha

    2015-01-01

    Detailed characterisation of the properties of composite materials with nanoscale fibres is central for the further progress in optimization of their manufacturing and properties. In the present study, a methodology for the determination and analysis of the volumetric composition of nanocomposites...... 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...

  15. Surfactant enhanced volumetric sweep efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Harwell, J.H.; Scamehorn, J.F.

    1989-10-01

    Surfactant-enhanced waterflooding is a novel EOR method aimed to improve the volumetric sweep efficiencies in reservoirs. The technique depends upon the ability to induce phase changes in surfactant solutions by mixing with surfactants of opposite charge or with salts of appropriate type. One surfactant or salt solution is injected into the reservoir. It is followed later by injection of another surfactant or salt solution. The sequence of injections is arranged so that the two solutions do not mix until they are into the permeable regions well away from the well bore. When they mix at this point, by design they form a precipitate or gel-like coacervate phase, plugging this permeable region, forcing flow through less permeable regions of the reservoir, improving sweep efficiency. The selectivity of the plugging process is demonstrated by achieving permeability reductions in the high permeable regions of Berea sandstone cores. Strategies were set to obtain a better control over the plug placement and the stability of plugs. A numerical simulator has been developed to investigate the potential increases in oil production of model systems. Furthermore, the hardness tolerance of anionic surfactant solutions is shown to be enhanced by addition of monovalent electrolyte or nonionic surfactants. 34 refs., 32 figs., 8 tabs.

  16. Drug delivery system for an anticancer agent, chlorogenate-Zn/Al-layered double hydroxide nanohybrid synthesised using direct co-precipitation and ion exchange methods

    Energy Technology Data Exchange (ETDEWEB)

    Barahuie, Farahnaz [Materials Synthesis and Characterization Laboratory, Institute of Advanced Technology (ITMA), Universiti Putra Malaysia, 43400 UPM Serdang, Selangor (Malaysia); Hussein, Mohd Zobir, E-mail: mzobir@putra.upm.edu.my [Materials Synthesis and Characterization Laboratory, Institute of Advanced Technology (ITMA), Universiti Putra Malaysia, 43400 UPM Serdang, Selangor (Malaysia); Arulselvan, Palanisamy [Laboratory of Vaccines and Immunotherapeutics, Institute of Bioscience, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor (Malaysia); Fakurazi, Sharida [Laboratory of Vaccines and Immunotherapeutics, Institute of Bioscience, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor (Malaysia); Department of Human Anatomy, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor (Malaysia); Zainal, Zulkarnain [Materials Synthesis and Characterization Laboratory, Institute of Advanced Technology (ITMA), Universiti Putra Malaysia, 43400 UPM Serdang, Selangor (Malaysia)

    2014-09-15

    A nano-structured drug-inorganic clay hybrid involving an active anticancer compound, which is chlorogenic acid (CA) intercalated into Zn/Al-layered double hydroxide, has been assembled via ion-exchange and co-precipitation methods to form a nanohybrid CZAE (a chlorogenic acid-Zn/Al nanohybrid synthesised using an ion-exchange method) and CZAC (a chlorogenic acid-Zn/Al nanohybrid synthesised using a direct method), respectively. The X-ray diffraction (XRD) results confirmed that the CA-LDH had a hybrid structure in which the anionic chlorogenate is arranged between the interlayers as a horizontal monolayer at 90 and 20° angles from the x axis for CZAE and CZAC, respectively. Both nanohybrids have the properties of mesoporous materials. The high loading percentage of chlorogenic acid (approximately 43.2% for CZAE and 45.3% for CZAC) with basal spacings of 11.7 and 12.6 Å for CZAE and CZAC, respectively, corroborates the successful intercalation of chlorogenic acid into the interlayer gallery of layered double hydroxides. Free chlorogenic acid and the synthesised nanocomposites (CZAE, CZAC) were assessed for their cytotoxicity against various cancer cells. The Fourier transform infrared data supported the formation of both nanohybrids, and a thermal analysis showed that the nanohybrids are more thermally stable than their counterparts. The chlorogenate shows a sustained release, and the release rate of chlorogenate from CZAE and CZAC nanohybrids at pH 7.4 is remarkably lower than that at pH 4.8 due to their different release mechanisms. The release rate of chlorogenate from both nanohybrids can be described as pseudo-second order. The present investigation revealed the potential of the nanohybrids to enhance the in vitro anti-tumour effect of chlorogenic acid in liver and lung cancer cells in vitro. - Highlights: • We intercalated chlorogenic into Zn/Al-layered double hydroxide by ion-exchange and coprecipitation methods. • The two methods gave nanocomposites

  17. Flexible Volumetric Structure

    Science.gov (United States)

    Cagle, Christopher M. (Inventor); Schlecht, Robin W. (Inventor)

    2014-01-01

    A flexible volumetric structure has a first spring that defines a three-dimensional volume and includes a serpentine structure elongatable and compressible along a length thereof. A second spring is coupled to at least one outboard edge region of the first spring. The second spring is a sheet-like structure capable of elongation along an in-plane dimension thereof. The second spring is oriented such that its in-plane dimension is aligned with the length of the first spring's serpentine structure.

  18. Fe(II)–Al(III) layered double hydroxides prepared by ultrasound-assisted co-precipitation method for the reduction of bromate

    Energy Technology Data Exchange (ETDEWEB)

    Zhong, Yu [College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082 (China); Yang, Qi, E-mail: yangqi@hnu.edu.cn [College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082 (China); Luo, Kun; Wu, Xiuqiong [College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082 (China); Li, Xiaoming, E-mail: xmli@hnu.edu.cn [College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082 (China); Liu, Yang [College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Urban and Rural Garbage Disposal Technology Research Center, Hunan Province, Changsha 410082 (China); Tang, Wangwang; Zeng, Guangming; Peng, Bo [College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082 (China)

    2013-04-15

    Highlights: ► Fe(II)–Al(III) LDHs were synthesized by ultrasound-assisted co-precipitation method. ► The Fe–Al (30 min) exhibited highly reduction reactivity on bromate. ► Pseudo-first-order model described the experimental data well. ► The mechanisms of bromate removal were proposed. -- Abstract: Bromate is recognized as an oxyhalide disinfection byproduct in drinking water. In this paper, Fe(II)–Al(III) layered double hydroxides (Fe–Al LDHs) prepared by the ultrasound-assisted co-precipitation method were used for the reduction of bromate in solution. The Fe–Al LDHs particles were characterized by X-ray diffractometer, scanning electron microscopy and thermogravimetry–differential scanning calorimetry. It was found that ultrasound irradiation assistance promoted the formation of the hydrotalcite-like phase and then improved the removal efficiency of bromate. In addition, the effects of solid-to-solution ratio, contact time, initial bromate concentration, initial pH, coexisting anions on the bromate removal were investigated. The results showed the bromate with an initial concentration of 1.56 μmol/L could be completely removed from solution by Fe–Al LDHs within 120 min. When the initial bromate concentration was 7.81 μmol/L, the Fe–Al LDHs with irradiation time of 30 min exhibited the optimum removal efficiency and the bromate removal capacity (q{sub e}) was 6.80 μmol/g. In addition, the appearance of sulfate and production of bromide were observed simultaneously in this process, which suggested that ion-exchange between sulfate and bromate, and the reduction of bromate to bromide by Fe{sup 2+} were the main mechanisms responsible for the bromate removal by Fe–Al LDHs.

  19. Drug delivery system for an anticancer agent, chlorogenate-Zn/Al-layered double hydroxide nanohybrid synthesised using direct co-precipitation and ion exchange methods

    Science.gov (United States)

    Barahuie, Farahnaz; Hussein, Mohd Zobir; Arulselvan, Palanisamy; Fakurazi, Sharida; Zainal, Zulkarnain

    2014-09-01

    A nano-structured drug-inorganic clay hybrid involving an active anticancer compound, which is chlorogenic acid (CA) intercalated into Zn/Al-layered double hydroxide, has been assembled via ion-exchange and co-precipitation methods to form a nanohybrid CZAE (a chlorogenic acid-Zn/Al nanohybrid synthesised using an ion-exchange method) and CZAC (a chlorogenic acid-Zn/Al nanohybrid synthesised using a direct method), respectively. The X-ray diffraction (XRD) results confirmed that the CA-LDH had a hybrid structure in which the anionic chlorogenate is arranged between the interlayers as a horizontal monolayer at 90 and 20° angles from the x axis for CZAE and CZAC, respectively. Both nanohybrids have the properties of mesoporous materials. The high loading percentage of chlorogenic acid (approximately 43.2% for CZAE and 45.3% for CZAC) with basal spacings of 11.7 and 12.6 Å for CZAE and CZAC, respectively, corroborates the successful intercalation of chlorogenic acid into the interlayer gallery of layered double hydroxides. Free chlorogenic acid and the synthesised nanocomposites (CZAE, CZAC) were assessed for their cytotoxicity against various cancer cells. The Fourier transform infrared data supported the formation of both nanohybrids, and a thermal analysis showed that the nanohybrids are more thermally stable than their counterparts. The chlorogenate shows a sustained release, and the release rate of chlorogenate from CZAE and CZAC nanohybrids at pH 7.4 is remarkably lower than that at pH 4.8 due to their different release mechanisms. The release rate of chlorogenate from both nanohybrids can be described as pseudo-second order. The present investigation revealed the potential of the nanohybrids to enhance the in vitro anti-tumour effect of chlorogenic acid in liver and lung cancer cells in vitro.

  20. Application of dissolvable layered double hydroxides as sorbent in dispersive solid-phase extraction and extraction by co-precipitation for the determination of aromatic acid anions.

    Science.gov (United States)

    Tang, Sheng; Lee, Hian Kee

    2013-08-06

    Three types of magnesium-aluminum layered double hydroxides were synthesized and employed as solid-phase extraction (SPE) sorbents to extract several aromatic acids (protocatechuic acid, mandelic acid, phthalic acid, benzoic acid, and salicylic acid) from aqueous samples. An interesting feature of these sorbents is that they dissolve when the pH of the solution is lower than 4. Thus, the analyte elution step, as needed in conventional sorbent-based extraction, was obviated by dissolving the sorbent in acid after extraction and separation from the sample solution. The extract was then directly injected into a high-performance liquid chromatography-ultraviolet detection system for analysis. In the key adsorption process, both dispersive SPE and co-precipitation extraction with the sorbents were conducted and experimental parameters such as pH, temperature, and extraction time were optimized. The results showed that both extraction methods provided low limits of detection (0.03-1.47 μg/L) and good linearity (r(2) > 0.9903). The optimized extraction conditions were applied to human urine and sports drink samples. This new and interesting extraction approach was demonstrated to be a fast and efficient procedure for the extraction of organic anions from aqueous samples.

  1. Applications versus properties of Mg–Al layered double hydroxides provided by their syntheses methods: Alkoxide and alkoxide-free sol–gel syntheses and hydrothermal precipitation

    KAUST Repository

    Chubar, Natalia

    2013-12-01

    A tremendous number of studies have examined layered double hydroxides (LDH) for their technological applications in the ion exchange removal of toxic ions, recovery of valuable substances, catalysis, CO2 capture, as a layered host for storage/delivery of biologically active molecules, additives to plastics and building materials, and other functions. Numerous publications always conclude that the materials (prepared, as a rule, using the oldest synthesis method) are very promising for each investigated application; however, the main chemical industries producing these materials advertise them mainly (or only) as plastic additives. The authors performed extensive research using many of the appropriate methods to compare the structure, surface and adsorptive properties of three Mg-Al LHDs produced by advanced synthesis methods. One industrial sample (by Sasol, Germany) prepared by the alkoxide sol-gel method and two novel Mg-Al LDHs synthesised in-house by alkoxide-free sol-gel and hydrothermal precipitation approaches were investigated. Reasons for the very different adsorptive selectivity of the three LDHs towards arsenate, selenate, phosphate, arsenite and selenite have been provided, highlighting the role of speciation of the interlayer carbonate, aluminium, magnesium, interlayer hydration and moisture content in the adsorptive selectivity towards each toxic anion. This work is the first report presenting the regularities of the LDHs structure, surface and anion exchange properties as a function of their syntheses method. It establishes the links to potential technological applications of each investigated LDH and explains the necessary properties required to make the technological application cost-effective and efficient. The paper might accelerate industrial applications of these advanced materials. © 2013 Elsevier B.V.

  2. Quantitative Techniques in Volumetric Analysis

    Science.gov (United States)

    Zimmerman, John; Jacobsen, Jerrold J.

    1996-12-01

    Quantitative Techniques in Volumetric Analysis is a visual library of techniques used in making volumetric measurements. This 40-minute VHS videotape is designed as a resource for introducing students to proper volumetric methods and procedures. The entire tape, or relevant segments of the tape, can also be used to review procedures used in subsequent experiments that rely on the traditional art of quantitative analysis laboratory practice. The techniques included are: Quantitative transfer of a solid with a weighing spoon Quantitative transfer of a solid with a finger held weighing bottle Quantitative transfer of a solid with a paper strap held bottle Quantitative transfer of a solid with a spatula Examples of common quantitative weighing errors Quantitative transfer of a solid from dish to beaker to volumetric flask Quantitative transfer of a solid from dish to volumetric flask Volumetric transfer pipet A complete acid-base titration Hand technique variations The conventional view of contemporary quantitative chemical measurement tends to focus on instrumental systems, computers, and robotics. In this view, the analyst is relegated to placing standards and samples on a tray. A robotic arm delivers a sample to the analysis center, while a computer controls the analysis conditions and records the results. In spite of this, it is rare to find an analysis process that does not rely on some aspect of more traditional quantitative analysis techniques, such as careful dilution to the mark of a volumetric flask. Figure 2. Transfer of a solid with a spatula. Clearly, errors in a classical step will affect the quality of the final analysis. Because of this, it is still important for students to master the key elements of the traditional art of quantitative chemical analysis laboratory practice. Some aspects of chemical analysis, like careful rinsing to insure quantitative transfer, are often an automated part of an instrumental process that must be understood by the

  3. Test Facility for Volumetric Absorber

    Energy Technology Data Exchange (ETDEWEB)

    Ebert, M.; Dibowski, G.; Pfander, M.; Sack, J. P.; Schwarzbozl, P.; Ulmer, S.

    2006-07-01

    Long-time testing of volumetric absorber modules is an inevitable measure to gain the experience and reliability required for the commercialization of the open volumetric receiver technology. While solar tower test facilities are necessary for performance measurements of complete volumetric receivers, the long-term stability of individual components can be tested in less expensive test setups. For the qualification of the aging effects of operating cycles on single elements of new absorber materials and designs, a test facility was developed and constructed in the framework of the KOSMOSOL project. In order to provide the concentrated solar radiation level, the absorber test facility is integrated into a parabolic dish system at the Plataforma Solar de Almeria (PSA) in Spain. Several new designs of ceramic absorbers were developed and tested during the last months. (Author)

  4. Analysis of Changing Swarm Rate using Volumetric Strain

    Science.gov (United States)

    Kumazawa, T.; Ogata, Y.; Kimura, K.; Maeda, K.; Kobayashi, A.

    2015-12-01

    Near the eastern coast of Izu peninsula is an active submarine volcanic region in Japan, where magma intrusions have been observed many times. The forecast of earthquake swarm activities and eruptions are serious concern particularly in nearby hot spring resort areas. It is well known that temporal durations of the swarm activities have been correlated with early volumetric strain changes at a certain observation station of about 20 km distance apart. Therefore the Earthquake Research Committee (2010) investigated some empirical statistical relations to predict sizes of the swarm activity. Here we looked at the background seismicity rate changes during these swarm periods using the non-stationary ETAS model (Kumazawa and Ogata, 2013, 2014), and have found the followings. The modified volumetric strain data, by removing the effect of earth tides, precipitation and coseismic jumps, have significantly higher cross-correlations to the estimated background rates of the ETAS model than to the swarm rate-changes. Specifically, the background seismicity rate synchronizes clearer to the strain change by the lags around a half day. These relations suggest an enhanced prediction of earthquakes in this region using volumetric strain measurements. Hence we propose an extended ETAS model where the background rate is modulated by the volumetric strain data. We have also found that the response function to the strain data can be well approximated by an exponential functions with the same decay rate, but that their intersects are inversely proportional to the distances between the volumetric strain-meter and the onset location of the swarm. Our numerical results by the same proposed model show consistent outcomes for the various major swarms in this region.

  5. Applications vs properties of Mg-Al Layered Double Hydroxides provided by their syntheses methods: alkoxide and alkoxide-free sol-gel syntheses and hydrothermal precipitation

    NARCIS (Netherlands)

    Chubar, N.; Gerda, V.; Megantari, O.; Mičušík, M.; Omastova, M.; Heister, K.; Man, P.; Fraissard, J.

    2013-01-01

    A tremendous number of studies have examined layered double hydroxides (LDH) for their technological applications in the ion exchange removal of toxic ions, recovery of valuable substances, catalysis, CO2 capture, as a layered host for storage/delivery of biologically active molecules, additives to

  6. Applications vs properties of Mg-Al Layered Double Hydroxides provided by their syntheses methods: alkoxide and alkoxide-free sol-gel syntheses and hydrothermal precipitation

    NARCIS (Netherlands)

    Chubar, N.; Gerda, V.; Megantari, O.; Mičušík, M.; Omastova, M.; Heister, K.; Man, P.; Fraissard, J.

    2013-01-01

    A tremendous number of studies have examined layered double hydroxides (LDH) for their technological applications in the ion exchange removal of toxic ions, recovery of valuable substances, catalysis, CO2 capture, as a layered host for storage/delivery of biologically active molecules, additives to

  7. Volumetric Three-Dimensional Display Systems

    Science.gov (United States)

    Blundell, Barry G.; Schwarz, Adam J.

    2000-03-01

    A comprehensive study of approaches to three-dimensional visualization by volumetric display systems This groundbreaking volume provides an unbiased and in-depth discussion on a broad range of volumetric three-dimensional display systems. It examines the history, development, design, and future of these displays, and considers their potential for application to key areas in which visualization plays a major role. Drawing substantially on material that was previously unpublished or available only in patent form, the authors establish the first comprehensive technical and mathematical formalization of the field, and examine a number of different volumetric architectures. System level design strategies are presented, from which proposals for the next generation of high-definition predictable volumetric systems are developed. To ensure that researchers will benefit from work already completed, they provide: * Descriptions of several recent volumetric display systems prepared from material supplied by the teams that created them * An abstract volumetric display system design paradigm * An historical summary of 90 years of development in volumetric display system technology * An assessment of the strengths and weaknesses of many of the systems proposed to date * A unified presentation of the underlying principles of volumetric display systems * A comprehensive bibliography Beautifully supplemented with 17 color plates that illustrate volumetric images and prototype displays, Volumetric Three-Dimensional Display Systems is an indispensable resource for professionals in imaging systems development, scientific visualization, medical imaging, computer graphics, aerospace, military planning, and CAD/CAE.

  8. A reduced volumetric expansion factor plot

    Science.gov (United States)

    Hendricks, R. C.

    1979-01-01

    A reduced volumetric expansion factor plot has been constructed for simple fluids which is suitable for engineering computations in heat transfer. Volumetric expansion factors have been found useful in correlating heat transfer data over a wide range of operating conditions including liquids, gases and the near critical region.

  9. 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.

  10. Precipitation of the rare earth double sodium and rare earths from the sulfuric liquor and the conversion into rare earth hydroxides through meta ethic reaction; Precipitacao do sulfato duplo de terras raras e sodio a partir de licor sulfurico e sua conversao em hidroxido de terras raras mediante reacao metatetica

    Energy Technology Data Exchange (ETDEWEB)

    Abreu, Renata D.; Oliveira, Ester F.; Brito, Walter de; Morais, Carlos A. [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)]. E-mails: rda@cdtn.br; esterfo@cdtn.br; britow@cdtn.br; cmorais@cdtn.br

    2007-07-01

    This work presents the purification study of the rare earths through precipitation of rare earth and sodium (Na TR (SO{sub 4}){sub 2}. x H{sub 2}O)) double sulfate and his conversion to rare earths hydroxide TR(OH){sub 3} by meta ethic reaction through the addition of sodium hydroxide solution to the solid double sulfate. The study used the sulfuric liquor as rare earth sample, generated in the chemical processing of the monazite with sulfuric acid by the Industrias Nucleares do Brasil - INB, Brazil, after the thorium and uranium extraction. The work investigated the influence of the main variables involved in the precipitation of Na TR(SO{sub 4}){sub 2}.xH{sub 2}O and in the conversion for the TR(OH){sub 3}, as follows: type and excess of the precipitation agent, temperature and time reaction. The obtained solid composites were characterized by X-ray diffraction, infrared and chemical analysis. The double sulfate diffractogram indicated the Na TR(SO{sub 4}){sub 2} mono-hydrated. The characterization of the metatese products has shown that, for obtaining the complete conversion of NaTR(SO{sub 4}){sub 2}.H{sub 2}O into TR(OH){sub 3}, the reaction must be hot processed ({approx}70 deg C) and with small excess of Na OH ({<=} 5 percent). (author)

  11. Nonequilibrium volumetric response of shocked polymers

    Energy Technology Data Exchange (ETDEWEB)

    Clements, B E [Los Alamos National Laboratory

    2009-01-01

    Polymers are well known for their non-equilibrium deviatoric behavior. However, investigations involving both high rate shock experiments and equilibrium measured thermodynamic quantities remind us that the volumetric behavior also exhibits a non-equilibrium response. Experiments supporting the notion of a non-equilibrium volumetric behavior will be summarized. Following that discussion, a continuum-level theory is proposed that will account for both the equilibrium and non-equilibrium response. Upon finding agreement with experiment, the theory is used to study the relaxation of a shocked polymer back towards its shocked equilibrium state.

  12. Process conditions and volumetric composition in composites

    DEFF Research Database (Denmark)

    Madsen, Bo

    2013-01-01

    The obtainable volumetric composition in composites is linked to the gravimetric composition, and it is influenced by the conditions of the manufacturing process. A model for the volumetric composition is presented, where the volume fractions of fibers, matrix and porosity are calculated as a fun...... is increased. Altogether, the model is demonstrated to be a valuable tool for a quantitative analysis of the effect of process conditions. Based on the presented findings and considerations, examples of future work are mentioned for the further improvement of the model.......The obtainable volumetric composition in composites is linked to the gravimetric composition, and it is influenced by the conditions of the manufacturing process. A model for the volumetric composition is presented, where the volume fractions of fibers, matrix and porosity are calculated...... as a function of the fiber weight fraction, and where parameters are included for the composite microstructure, and the fiber assembly compaction behavior. Based on experimental data of composites manufactured with different process conditions, together with model predictions, different types of process related...

  13. Indexing Volumetric Shapes with Matching and Packing.

    Science.gov (United States)

    Koes, David Ryan; Camacho, Carlos J

    2015-04-01

    We describe a novel algorithm for bulk-loading an index with high-dimensional data and apply it to the problem of volumetric shape matching. Our matching and packing algorithm is a general approach for packing data according to a similarity metric. First an approximate k-nearest neighbor graph is constructed using vantage-point initialization, an improvement to previous work that decreases construction time while improving the quality of approximation. Then graph matching is iteratively performed to pack related items closely together. The end result is a dense index with good performance. We define a new query specification for shape matching that uses minimum and maximum shape constraints to explicitly specify the spatial requirements of the desired shape. This specification provides a natural language for performing volumetric shape matching and is readily supported by the geometry-based similarity search (GSS) tree, an indexing structure that maintains explicit representations of volumetric shape. We describe our implementation of a GSS tree for volumetric shape matching and provide a comprehensive evaluation of parameter sensitivity, performance, and scalability. Compared to previous bulk-loading algorithms, we find that matching and packing can construct a GSS-tree index in the same amount of time that is denser, flatter, and better performing, with an observed average performance improvement of 2X.

  14. Global Precipitation Measurement Cold Season Precipitation Experiment (GCPEx): For Measurement Sake Let it Snow

    Science.gov (United States)

    Skofronick-Jackson, Gail; Hudak, David; Petersen, Walter; Nesbitt, Stephen W.; Chandrasekar, V.; Durden, Stephen; Gleicher, Kirstin J.; Huang, Gwo-Jong; Joe, Paul; Kollias, Pavlos; Reed, Kimberly A.; Schwaller, Mathew R.; Stewart, Ronald; Tanelli, Simone; Tokay, Ali; Wang, James R.; Wolde, Mengistu

    2014-01-01

    As a component of the Earth's hydrologic cycle, and especially at higher latitudes,falling snow creates snow pack accumulation that in turn provides a large proportion of the fresh water resources required by many communities throughout the world. To assess the relationships between remotely sensed snow measurements with in situ measurements, a winter field project, termed the Global Precipitation Measurement (GPM) mission Cold Season Precipitation Experiment (GCPEx), was carried out in the winter of 2011-2012 in Ontario, Canada. Its goal was to provide information on the precipitation microphysics and processes associated with cold season precipitation to support GPM snowfall retrieval algorithms that make use of a dual-frequency precipitation radar and a passive microwave imager on board the GPM core satellite,and radiometers on constellation member satellites. Multi-parameter methods are required to be able to relate changes in the microphysical character of the snow to measureable parameters from which precipitation detection and estimation can be based. The data collection strategy was coordinated, stacked, high-altitude and in-situ cloud aircraft missions with three research aircraft sampling within a broader surface network of five ground sites taking in-situ and volumetric observations. During the field campaign 25 events were identified and classified according to their varied precipitation type, synoptic context, and precipitation amount. Herein, the GCPEx fieldcampaign is described and three illustrative cases detailed.

  15. 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.

  16. 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.)

  17. PRECIPITATION OF PLUTONOUS PEROXIDE

    Science.gov (United States)

    Barrick, J.G.; Manion, J.P.

    1961-08-15

    A precipitation process for recovering plutonium values contained in an aqueous solution is described. In the process for precipitating plutonium as plutonous peroxide, hydroxylamine or hydrazine is added to the plutoniumcontaining solution prior to the addition of peroxide to precipitate plutonium. The addition of hydroxylamine or hydrazine increases the amount of plutonium precipitated as plutonous peroxide. (AEC)

  18. 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.

  19. Twentieth century ENSO-related precipitation mean states in twentieth century reanalysis, reconstructed precipitation and CMIP5 models

    Science.gov (United States)

    Dai, Ni; Arkin, Phillip A.

    2017-05-01

    El Niño-Southern Oscillation (ENSO)-related precipitation during the entire twentieth century is compared among the twentieth century reanalysis (20CR), a statistically reconstructed precipitation dataset (REC) and 30 Coupled Model Intercomparison Project Phase 5 (CMIP5) models. Empirical orthogonal functions, ENSO-related precipitation composites based on sea surface temperature (SST)-constructed ENSO index and singular value decomposition (SVD) are employed to extract ENSO-related precipitation/SST signals in each dataset. With the background trend being removed in all of the data, our results show that the REC and the 20CR resemble both in their precipitation climatology and ENSO-related precipitation results. The biases in the CMIP5 models precipitation climatology such as dry equator over the Pacific Ocean, "double-intertropical convergence zones (ITCZs)" and overly zonal Southern Pacific convergence zone (SPCZ) are major reasons for lowering spatial correlations with the REC and the 20CR precipitation climatology. Two groups of CMIP5 models are built based on severity of these biases in their precipitation background and the spatial correlations of ENSO-related precipitation with the observations. Compared with the group with more severe biases in its precipitation climatology, the group with smaller biases tends to produce more ENSO-like precipitation patterns, simulate more realistic mean magnitude and seasonal variability of ENSO precipitation signals, as well as generating better ENSO-related SST/precipitation correlation patterns produced in its SVD analysis. The ENSO-related precipitation biases in the CMIP5 models over the western Pacific and Indian Ocean, as well as the equatorial Pacific, are strongly related with their precipitation climatology biases over these regions. The ENSO-related precipitation biases over the off-equator eastern Pacific Ocean are associated with both the "double-ITCZs" biases in the precipitation climatology and the ENSO

  20. Twentieth century ENSO-related precipitation mean states in twentieth century reanalysis, reconstructed precipitation and CMIP5 models

    Science.gov (United States)

    Dai, Ni; Arkin, Phillip A.

    2016-07-01

    El Niño-Southern Oscillation (ENSO)-related precipitation during the entire twentieth century is compared among the twentieth century reanalysis (20CR), a statistically reconstructed precipitation dataset (REC) and 30 Coupled Model Intercomparison Project Phase 5 (CMIP5) models. Empirical orthogonal functions, ENSO-related precipitation composites based on sea surface temperature (SST)-constructed ENSO index and singular value decomposition (SVD) are employed to extract ENSO-related precipitation/SST signals in each dataset. With the background trend being removed in all of the data, our results show that the REC and the 20CR resemble both in their precipitation climatology and ENSO-related precipitation results. The biases in the CMIP5 models precipitation climatology such as dry equator over the Pacific Ocean, "double-intertropical convergence zones (ITCZs)" and overly zonal Southern Pacific convergence zone (SPCZ) are major reasons for lowering spatial correlations with the REC and the 20CR precipitation climatology. Two groups of CMIP5 models are built based on severity of these biases in their precipitation background and the spatial correlations of ENSO-related precipitation with the observations. Compared with the group with more severe biases in its precipitation climatology, the group with smaller biases tends to produce more ENSO-like precipitation patterns, simulate more realistic mean magnitude and seasonal variability of ENSO precipitation signals, as well as generating better ENSO-related SST/precipitation correlation patterns produced in its SVD analysis. The ENSO-related precipitation biases in the CMIP5 models over the western Pacific and Indian Ocean, as well as the equatorial Pacific, are strongly related with their precipitation climatology biases over these regions. The ENSO-related precipitation biases over the off-equator eastern Pacific Ocean are associated with both the "double-ITCZs" biases in the precipitation climatology and the ENSO

  1. A SUBDIVISION SCHEME FOR VOLUMETRIC MODELS

    Institute of Scientific and Technical Information of China (English)

    GhulamMustafa; LiuXuefeng

    2005-01-01

    In this paper, a subdivision scheme which generalizes a surface scheme in previous papers to volume meshes is designed. The scheme exhibits significant control over shrink-age/size of volumetric models. It also has the ability to conveniently incorporate boundaries and creases into a smooth limit shape of models. The method presented here is much simpler and easier as compared to MacCracken and Joy's. This method makes no restrictions on the local topology of meshes. Particularly, it can be applied without any change to meshes of nonmanifold topology.

  2. Volumetric composition in composites and historical data

    DEFF Research Database (Denmark)

    Lilholt, Hans; Madsen, Bo

    2013-01-01

    guidance to the optimal combination of fibre content, matrix content and porosity content, in order to achieve the best obtainable properties. Several composite materials systems have been shown to be handleable with this model. An extensive series of experimental data for the system of cellulose fibres...... and polymer (resin) was produced in 1942 – 1944, and these data have been (re-)analysed by the volumetric composition model, and the property values for density, stiffness and strength have been evaluated. Good agreement has been obtained and some further observations have been extracted from the analysis....

  3. IMITATION OF STANDARD VOLUMETRIC ACTIVITY METAL SAMPLES

    Directory of Open Access Journals (Sweden)

    A. I. Zhukouski

    2016-01-01

    Full Text Available Due to the specific character of problems in the field of ionizing radiation spectroscopy, the R&D and making process of standard volumetric activity metal samples (standard samples for calibration and verification of spectrometric equipment is not only expensive, but also requires the use of highly qualified experts and a unique specific equipment. Theoretical and experimental studies performed have shown the possibility to use imitators as a set of alternating point sources of gamma radiation and metal plates and their use along with standard volumetric activity metal samples for calibration of scintillation-based detectors used in radiation control in metallurgy. Response functions or instrumental spectra of such spectrometer to radionuclides like 137Cs, 134Cs, 152Eu, 154Eu, 60Co, 54Mn, 232Th, 226Ra, 65Zn, 125Sb+125mTe, 106Ru+106Rh, 94Nb, 110mAg, 233U, 234U, 235U and 238U are required for calibration in a given measurement geometry. Standard samples in the form of a probe made of melt metal of a certain diameter and height are used in such measurements. However, the production of reference materials is costly and even problematic for such radionuclides as 94Nb, 125Sb+125mTe, 234U, 235U  etc. A recognized solution to solve this problem is to use the Monte-Carlo simulation method. Instrumental experimental and theoretical spectra obtained by using standard samples and their imitators show a high compliance between experimental spectra of real samples and the theoretical ones of their Monte-Carlo models, between spectra of real samples and the ones of their imitators and finally, between experimental spectra of real sample imitators and the theoretical ones of their Monte-Carlo models. They also have shown the adequacy and consistency of the approach in using a combination of metal scattering layers and reference point gamma-ray sources instead of standard volumetric activity metal samples. As for using several reference point gamma-ray sources

  4. Magnetic volumetric hologram memory with magnetic garnet.

    Science.gov (United States)

    Nakamura, Yuichi; Takagi, Hiroyuki; Lim, Pang Boey; Inoue, Mitsuteru

    2014-06-30

    Holographic memory is a promising next-generation optical memory that has a higher recording density and a higher transfer rate than other types of memory. In holographic memory, magnetic garnet films can serve as rewritable holographic memory media by use of magneto-optical effect. We have now demonstrated that a magnetic hologram can be recorded volumetrically in a ferromagnetic garnet film and that the signal image can be reconstructed from it for the first time. In addition, multiplicity of the magnetic hologram was also confirmed; the image could be reconstructed from a spot overlapped by other spots.

  5. Predicting Offshore Swarm Rate Changes by Volumetric Strain Changes in Izu Peninsula, Japan

    Science.gov (United States)

    Kumazawa, T.; Ogata, Y.; Kimura, Y.; Maeda, K.; Kobayashi, A.

    2014-12-01

    The eastern offshore of Izu peninsula is one of the well known volcanic active regions in Japan, where magma intrusions have been observed several times since 1980s monitored by strain-meters located nearby. Major swarm activities have been synchronously associated with coseismic and preseismic significant sizes of a volumetric strain changes (Earthquake Research Committee, 2010). We investigated the background seismicity changes during these earthquake swarms using the nonstationary ETAS model (Kumazawa and Ogata, 2013), and have found the followings. The modified volumetric strain change data by removing the effect of earth tides and precipitation as well as removing coseismic jumps have much higher cross-correlations to the background rates of the ETAS model than to the whole seismicity rate change of the ETAS, and further the strain changes precede the background seismicity by lag of about a day. This relation suggests an enhanced prediction of earthquakes in this region using volumetric strain measurements. Thus we propose an extended ETAS model where the background seismicity rate is predicted by the time series of preceding volumetric strain changes. Our numerical results for Izu region show consistent outcomes throughout the major swarms in this region. References Earthquake Research Committee (2010). Report on "Prediction of seismic activity in the Izu Eastern Region" (in Japanese), http://www.jishin.go.jp/main/yosoku/izu/index.htm Kumazawa, T. and Ogata, Y. (2013). Quantitative description of induced seismic activity before and after the 2011 Tohoku-Oki earthquake by nonstationary ETAS model, J Geophys.Res. 118, 6165-6182.

  6. Modelled Precipitation Over Greenland

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set includes the annual total precipitation from 1985 to 1999 and monthly total precipitation from January 1985 to December 1999. The data is derived from...

  7. Disentangling volumetric and hydrational properties of proteins.

    Science.gov (United States)

    Voloshin, Vladimir P; Medvedev, Nikolai N; Smolin, Nikolai; Geiger, Alfons; Winter, Roland

    2015-02-05

    We used molecular dynamics simulations of a typical monomeric protein, SNase, in combination with Voronoi-Delaunay tessellation to study and analyze the temperature dependence of the apparent volume, Vapp, of the solute. We show that the void volume, VB, created in the boundary region between solute and solvent, determines the temperature dependence of Vapp to a major extent. The less pronounced but still significant temperature dependence of the molecular volume of the solute, VM, is essentially the result of the expansivity of its internal voids, as the van der Waals contribution to VM is practically independent of temperature. Results for polypeptides of different chemical nature feature a similar temperature behavior, suggesting that the boundary/hydration contribution seems to be a universal part of the temperature dependence of Vapp. The results presented here shine new light on the discussion surrounding the physical basis for understanding and decomposing the volumetric properties of proteins and biomolecules in general.

  8. All Photons Imaging Through Volumetric Scattering

    Science.gov (United States)

    Satat, Guy; Heshmat, Barmak; Raviv, Dan; Raskar, Ramesh

    2016-01-01

    Imaging through thick highly scattering media (sample thickness ≫ mean free path) can realize broad applications in biomedical and industrial imaging as well as remote sensing. Here we propose a computational “All Photons Imaging” (API) framework that utilizes time-resolved measurement for imaging through thick volumetric scattering by using both early arrived (non-scattered) and diffused photons. As opposed to other methods which aim to lock on specific photons (coherent, ballistic, acoustically modulated, etc.), this framework aims to use all of the optical signal. Compared to conventional early photon measurements for imaging through a 15 mm tissue phantom, our method shows a two fold improvement in spatial resolution (4db increase in Peak SNR). This all optical, calibration-free framework enables widefield imaging through thick turbid media, and opens new avenues in non-invasive testing, analysis, and diagnosis. PMID:27683065

  9. 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.

  10. A Technique for Volumetric CSG Based on Morphology

    DEFF Research Database (Denmark)

    Bærentzen, Jakob Andreas; Christensen, Niels Jørgen

    2001-01-01

    In this paper, a new technique for volumetric CSG is presented. The technique requires the input volumes to correspond to solids which fulfill a voxelization suitability criterion. Assume the CSG operation is union. The volumetric union of two such volumes is defined in terms of the voxelization...

  11. Precipitation of CuS and ZnS in a bubble column reactor

    NARCIS (Netherlands)

    Al-Tarazi, M.; Heesink, A. Bert M.; Versteeg, G. F.; Azzam, M. O. J.; Azzam, K.

    2005-01-01

    This work presents an experimental study into the precipitation of CuS and ZnS in a semibatch-wise operated bubble column. First the applied bubble column was characterized with respect to mass transfer phenomena. The influences of ionic strength and superficial gas velocity on volumetric mass trans

  12. Markov chain modeling of precipitation time series: Modeling waiting times between tipping bucket rain gauge tips

    DEFF Research Database (Denmark)

    Sørup, Hjalte Jomo Danielsen; Madsen, Henrik; Arnbjerg-Nielsen, Karsten

    2011-01-01

    A very fine temporal and volumetric resolution precipitation time series is modeled using Markov models. Both 1st and 2nd order Markov models as well as seasonal and diurnal models are investigated and evaluated using likelihood based techniques. The 2nd order Markov model is found to be insignif...

  13. Performance Metrics for Climate Model Evaluation: Application to CMIP5 Precipitation Simulations

    Science.gov (United States)

    Mehran, A.; AghaKouchak, A.; Phillips, T. J.

    2013-12-01

    Validation of gridded climate model simulations is fundamental to future improvements in model developments. Among the metrics, the contingency table, which includes a number of categorical indices, is extensively used in evaluation studies. While the categorical indices offer invaluable information, they do not provide any insight into the volume of the variable detected correctly/incorrectly. In this study, the contingency table categorical metrics are extended to volumetric indices for evaluation of gridded data. The suggested indices include (a) Volumetric Hit Index (VHI): volume of correctly detected simulations relative to the volume of the correctly detected simulations and missed observations; (b) Volumetric False Alarm Ratio (VFAR): volume of false simulations relative to the sum of simulations; (c) Volumetric Miss Index (VMI): volume of missed observations relative to the sum of missed observations and correctly detected simulations; and (d) the Volumetric Critical Success Index (VCSI). The latter provides an overall measure of volumetric performance including volumetric hits, false alarms and misses. Numerous studies have emphasized that climate simulations are subject to various biases and uncertainties. The objective of this study is to cross-validate 34 Coupled Model Inter-comparison Project Phase 5 (CMIP5) historical simulations of precipitation against the Global Precipitation Climatology Project (GPCP) data using the proposed performance metrics, quantifying model pattern discrepancies and biases for both entire data distributions and their upper tails. The results of the Volumetric Hit Index (VHI) analysis of the total monthly precipitation amounts show that most CMIP5 simulations are in good agreement with GPCP patterns in many areas, but their replication of observed precipitation over arid regions and certain sub-continental regions (e.g., northern Eurasia, eastern Russia, central Australia) is problematical. Overall, the VHI of the multi

  14. Soil volumetric water content measurements using TDR technique

    Directory of Open Access Journals (Sweden)

    S. Vincenzi

    1996-06-01

    Full Text Available A physical model to measure some hydrological and thermal parameters in soils will to be set up. The vertical profiles of: volumetric water content, matric potential and temperature will be monitored in different soils. The volumetric soil water content is measured by means of the Time Domain Reflectometry (TDR technique. The result of a test to determine experimentally the reproducibility of the volumetric water content measurements is reported together with the methodology and the results of the analysis of the TDR wave forms. The analysis is based on the calculation of the travel time of the TDR signal in the wave guide embedded in the soil.

  15. Iterative reconstruction of volumetric particle distribution

    Science.gov (United States)

    Wieneke, Bernhard

    2013-02-01

    For tracking the motion of illuminated particles in space and time several volumetric flow measurement techniques are available like 3D-particle tracking velocimetry (3D-PTV) recording images from typically three to four viewing directions. For higher seeding densities and the same experimental setup, tomographic PIV (Tomo-PIV) reconstructs voxel intensities using an iterative tomographic reconstruction algorithm (e.g. multiplicative algebraic reconstruction technique, MART) followed by cross-correlation of sub-volumes computing instantaneous 3D flow fields on a regular grid. A novel hybrid algorithm is proposed here that similar to MART iteratively reconstructs 3D-particle locations by comparing the recorded images with the projections calculated from the particle distribution in the volume. But like 3D-PTV, particles are represented by 3D-positions instead of voxel-based intensity blobs as in MART. Detailed knowledge of the optical transfer function and the particle image shape is mandatory, which may differ for different positions in the volume and for each camera. Using synthetic data it is shown that this method is capable of reconstructing densely seeded flows up to about 0.05 ppp with similar accuracy as Tomo-PIV. Finally the method is validated with experimental data.

  16. Precipitates in electrical steels

    Energy Technology Data Exchange (ETDEWEB)

    Jenkins, Keith [Development and Market Research, Cogent Power Limited, Corporation Road, Newport, South Wales NP19 OXT (United Kingdom)], E-mail: keith.jenkins@cogent-power.com; Lindenmo, Magnus [Development and Market Research, Cogent Power Limited, Corporation Road, Newport, South Wales NP19 OXT (United Kingdom)

    2008-10-15

    Precipitates heavily influence the magnetic properties of electrical steels, either as a key controlled requirement as part of the manufacturing process or as an unwanted harmful residual in the final product. In this current work copper-manganese sulphides precipitates are the primary inhibitor species in the conventional grain-oriented (CGO) steels examined and grain boundary pinning is effective at a mean precipitate size of 30-70 nm. The growth of CuMnS has been studied and the results show that a precipitate size above {approx}100 nm allows the onset of secondary recrystallisation in the heating conditions applied. The effect of precipitates on the magnetic properties of both grain-oriented and non-oriented steels in their final product form is then examined. Examples of grain-oriented material still containing large numbers of precipitates clearly show the detrimental effects with increases in total power loss of 40% or more. Loss deterioration by about 20% is also seen in samples of high silicon non-oriented material in which titanium carbo-nitride precipitates have been observed. In this case the precipitates are believed to have formed during cooling after final annealing. Finally a grain-oriented steel with a large number of very small precipitates, which do not seem to have any harmful effect on the magnetic properties, is demonstrated.

  17. 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...

  18. Hyperspectral image classification based on volumetric texture and dimensionality reduction

    Science.gov (United States)

    Su, Hongjun; Sheng, Yehua; Du, Peijun; Chen, Chen; Liu, Kui

    2015-06-01

    A novel approach using volumetric texture and reduced-spectral features is presented for hyperspectral image classification. Using this approach, the volumetric textural features were extracted by volumetric gray-level co-occurrence matrices (VGLCM). The spectral features were extracted by minimum estimated abundance covariance (MEAC) and linear prediction (LP)-based band selection, and a semi-supervised k-means (SKM) clustering method with deleting the worst cluster (SKMd) bandclustering algorithms. Moreover, four feature combination schemes were designed for hyperspectral image classification by using spectral and textural features. It has been proven that the proposed method using VGLCM outperforms the gray-level co-occurrence matrices (GLCM) method, and the experimental results indicate that the combination of spectral information with volumetric textural features leads to an improved classification performance in hyperspectral imagery.

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

    African Journals Online (AJOL)

    ... remote web-based mechanical-volumetric flow meter reading systems based on ... damage and also provides the ability to control and manage consumption. ... existing infrastructure of the telecommunications is used in data transmission.

  20. Microbial Activity and Precipitation at Solution-Solution Mixing Zones in Porous Media -- Subsurface Biogeochemical Research

    Energy Technology Data Exchange (ETDEWEB)

    Colwell, Frederick [Oregon State Univ., Corvallis, OR (United States); Wildenschild, Dorthe [Oregon State Univ., Corvallis, OR (United States); Wood, Brian [Oregon State Univ., Corvallis, OR (United States); Gerlach, Robin [Montana State Univ., Bozeman, MT (United States); Mitchell, Andrew [Montana State Univ., Bozeman, MT (United States); Redden, George [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2014-08-29

    The goal for this research was to understand how best to add compounds to receptive microbial communities in porous media in order to achieve optimal calcite precipitation in a volumetrically significant space and to understand the physiological health of the cells that are responsible for the calcite precipitation. The specific objectives were to: (1) develop better tools for visually examining biofilms in porous media and calcium carbonate precipitation being mediated by microbes in porous media, and (2) demonstrate the effectiveness of using that tool within a flow cell model system.

  1. 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.

  2. Serial volumetric registration of pulmonary CT studies

    Science.gov (United States)

    Silva, José Silvestre; Silva, Augusto; Sousa Santos, Beatriz

    2008-03-01

    Detailed morphological analysis of pulmonary structures and tissue, provided by modern CT scanners, is of utmost importance as in the case of oncological applications both for diagnosis, treatment, and follow-up. In this case, a patient may go through several tomographic studies throughout a period of time originating volumetric sets of image data that must be appropriately registered in order to track suspicious radiological findings. The structures or regions of interest may change their position or shape in CT exams acquired at different moments, due to postural, physiologic or pathologic changes, so, the exams should be registered before any follow-up information can be extracted. Postural mismatching throughout time is practically impossible to avoid being particularly evident when imaging is performed at the limiting spatial resolution. In this paper, we propose a method for intra-patient registration of pulmonary CT studies, to assist in the management of the oncological pathology. Our method takes advantage of prior segmentation work. In the first step, the pulmonary segmentation is performed where trachea and main bronchi are identified. Then, the registration method proceeds with a longitudinal alignment based on morphological features of the lungs, such as the position of the carina, the pulmonary areas, the centers of mass and the pulmonary trans-axial principal axis. The final step corresponds to the trans-axial registration of the corresponding pulmonary masked regions. This is accomplished by a pairwise sectional registration process driven by an iterative search of the affine transformation parameters leading to optimal similarity metrics. Results with several cases of intra-patient, intra-modality registration, up to 7 time points, show that this method provides accurate registration which is needed for quantitative tracking of lesions and the development of image fusion strategies that may effectively assist the follow-up process.

  3. Volumetric optoacoustic monitoring of endovenous laser treatments

    Science.gov (United States)

    Fehm, Thomas F.; Deán-Ben, Xosé L.; Schaur, Peter; Sroka, Ronald; Razansky, Daniel

    2016-03-01

    Chronic venous insufficiency (CVI) is one of the most common medical conditions with reported prevalence estimates as high as 30% in the adult population. Although conservative management with compression therapy may improve the symptoms associated with CVI, healing often demands invasive procedures. Besides established surgical methods like vein stripping or bypassing, endovenous laser therapy (ELT) emerged as a promising novel treatment option during the last 15 years offering multiple advantages such as less pain and faster recovery. Much of the treatment success hereby depends on monitoring of the treatment progression using clinical imaging modalities such as Doppler ultrasound. The latter however do not provide sufficient contrast, spatial resolution and three-dimensional imaging capacity which is necessary for accurate online lesion assessment during treatment. As a consequence, incidence of recanalization, lack of vessel occlusion and collateral damage remains highly variable among patients. In this study, we examined the capacity of volumetric optoacoustic tomography (VOT) for real-time monitoring of ELT using an ex-vivo ox foot model. ELT was performed on subcutaneous veins while optoacoustic signals were acquired and reconstructed in real-time and at a spatial resolution in the order of 200μm. VOT images showed spatio-temporal maps of the lesion progression, characteristics of the vessel wall, and position of the ablation fiber's tip during the pull back. It was also possible to correlate the images with the temperature elevation measured in the area adjacent to the ablation spot. We conclude that VOT is a promising tool for providing online feedback during endovenous laser therapy.

  4. Treatment planning for volumetric modulated arc therapy

    Energy Technology Data Exchange (ETDEWEB)

    Bedford, James L. [Joint Department of Physics, Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, Downs Road, Sutton, Surrey SM2 5PT (United Kingdom)

    2009-11-15

    Purpose: Volumetric modulated arc therapy (VMAT) is a specific type of intensity-modulated radiation therapy (IMRT) in which the gantry speed, multileaf collimator (MLC) leaf position, and dose rate vary continuously during delivery. A treatment planning system for VMAT is presented. Methods: Arc control points are created uniformly throughout one or more arcs. An iterative least-squares algorithm is used to generate a fluence profile at every control point. The control points are then grouped and all of the control points in a given group are used to approximate the fluence profiles. A direct-aperture optimization is then used to improve the solution, taking into account the allowed range of leaf motion of the MLC. Dose is calculated using a fast convolution algorithm and the motion between control points is approximated by 100 interpolated dose calculation points. The method has been applied to five cases, consisting of lung, rectum, prostate and seminal vesicles, prostate and pelvic lymph nodes, and head and neck. The resulting plans have been compared with segmental (step-and-shoot) IMRT and delivered and verified on an Elekta Synergy to ensure practicality. Results: For the lung, prostate and seminal vesicles, and rectum cases, VMAT provides a plan of similar quality to segmental IMRT but with faster delivery by up to a factor of 4. For the prostate and pelvic nodes and head-and-neck cases, the critical structure doses are reduced with VMAT, both of these cases having a longer delivery time than IMRT. The plans in general verify successfully, although the agreement between planned and measured doses is not very close for the more complex cases, particularly the head-and-neck case. Conclusions: Depending upon the emphasis in the treatment planning, VMAT provides treatment plans which are higher in quality and/or faster to deliver than IMRT. The scheme described has been successfully introduced into clinical use.

  5. Global Precipitation Measurement Poster

    Science.gov (United States)

    Azarbarzin, Art

    2010-01-01

    This poster presents an overview of the Global Precipitation Measurement (GPM) constellation of satellites which are designed to measure the Earth's precipitation. It includes the schedule of launches for the various satellites in the constellation, and the coverage of the constellation, It also reviews the mission capabilities, and the mission science objectives.

  6. Visualization and volumetric structures from MR images of the brain

    Energy Technology Data Exchange (ETDEWEB)

    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.

  7. Soft bilateral filtering volumetric shadows using cube shadow maps

    Science.gov (United States)

    Ali, Hatam H.; Sunar, Mohd Shahrizal; Kolivand, Hoshang

    2017-01-01

    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. PMID:28632740

  8. DEVELOPMENT OF POLYMER GEL SYSTEMS TO IMPROVE VOLUMETRIC SWEEP AND REDUCE PRODUCING WATER/OIL RATIOS

    Energy Technology Data Exchange (ETDEWEB)

    G. Paul Willhite; Don W. Green; Stan McCool; Min Cheng; Feiyan Chen

    2004-02-01

    The objectives of the research are to improve the effectiveness of polymer gels to increase volumetric sweep efficiency of fluid displacement processes and to reduce water production in production wells. The research is based on experimental data and conceptual and mathematical models developed from interpretation of experimental data. This report describes two types of mathematical models that were developed. One model type simulates the chemical reactions where polymer molecules are crosslinked to form a 3-dimensional network or gel. The model is based on statistical probabilities of reactions and yields molecular weights averages and distributions as functions of conversion. The second model type simulates the transport of chromium acetate, a common polymer crosslinker, through porous dolomite rock and includes the mechanisms of dolomite dissolution and chromium precipitation. The chromium transport model reasonably agreed with experimental data.

  9. Double Trouble

    NARCIS (Netherlands)

    Elsaesser, Thomas; Kievit, Robert; Simons, Jan

    1994-01-01

    Double Trouble highlights the career of Dutch scriptwriter and television producer Chiem van Houweninge, well-known for his long-running TV comedy series and as author of episodes for TV detective series. Double Trouble gives Van Houweninge's own views on writing and filming in television prime impo

  10. Double Trouble

    NARCIS (Netherlands)

    Elsaesser, Thomas; Kievit, Robert; Simons, Jan

    1994-01-01

    Double Trouble highlights the career of Dutch scriptwriter and television producer Chiem van Houweninge, well-known for his long-running TV comedy series and as author of episodes for TV detective series. Double Trouble gives Van Houweninge's own views on writing and filming in television prime

  11. Winter precipitation types and icing at the surface

    Energy Technology Data Exchange (ETDEWEB)

    Theriault, J.; Stewart, R. [McGill Univ., Montreal, PQ (Canada). Dept. of Atmospheric and Oceanic Sciences

    2005-07-01

    An understanding of the physics of winter precipitation formation mechanisms is important for the forecasting of winter storms and associated icing. Empirical techniques are generally used to account for many types of precipitation. This paper proposed a microphysics scheme able to predict liquid particles, solid particles and those with a mixture of solid and liquid particles within varying environmental conditions. A revised 1-D cloud model utilizing a double-moment microphysics scheme was presented. The basic physics of liquid and semi-liquid particles formation and their interaction with the environment were outlined. A detailed evolution of precipitation types and environmental conditions was examined using typical temperature profiles and a study of other atmospheric conditions. The double microphysics scheme predicted the total concentration and mixing of various hydrometeor categories which were divided into 2 different branches: frozen and liquid. Characteristics for the categories were presented. A comparison of temperature, moisture and precipitation profiles was presented, as well as a comparison of surface precipitation types. The relationship between sounding parameters and precipitation types was examined, and ranges of temperature and depth were outlined. The study showed that the occurrence of a particular precipitation type or combinations of types can be associated with a range of atmospheric profiles. Melting and refreezing parameters exhibited variations for the same precipitation types and their combinations were not produced within a single profile. It was concluded that profiles must be very precise to simulate certain combinations. 10 refs., 1 tab., 8 figs.

  12. Storage Gage Precipitation Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A storage gage is a precipitation gage that requires reading and maintenance only monthly or seasonal intervals. This library includes reports from such gages,...

  13. WPA Precipitation Tabulations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Hourly precipitation data tabulated under the Work Projects Administration (WPA), a New Deal program created to reduce unemployment during the Great Depression....

  14. Chemisorption And Precipitation Reactions

    Science.gov (United States)

    The transport and bioavailability of chemical components within soils is, in part, controlled by partitioning between solids and solution. General terms used to describe these partitioning reactions include chemisorption and precipitation. Chemisorption is inclusive of the suit...

  15. Improved volumetric imaging in tomosynthesis using combined multiaxial sweeps.

    Science.gov (United States)

    Gersh, Jacob A; Wiant, David B; Best, Ryan C M; Bennett, Marcus C; Munley, Michael T; King, June D; McKee, Mahta M; Baydush, Alan H

    2010-09-03

    This study explores the volumetric reconstruction fidelity attainable using tomosynthesis with a kV imaging system which has a unique ability to rotate isocentrically and with multiple degrees of mechanical freedom. More specifically, we seek to investigate volumetric reconstructions by combining multiple limited-angle rotational image acquisition sweeps. By comparing these reconstructed images with those of a CBCT reconstruction, we can gauge the volumetric fidelity of the reconstructions. In surgical situations, the described tomosynthesis-based system could provide high-quality volumetric imaging without requiring patient motion, even with rotational limitations present. Projections were acquired using the Digital Integrated Brachytherapy Unit, or IBU-D. A phantom was used which contained several spherical objects of varying contrast. Using image projections acquired during isocentric sweeps around the phantom, reconstructions were performed by filtered backprojection. For each image acquisition sweep configuration, a contrasting sphere is analyzed using two metrics and compared to a gold standard CBCT reconstruction. Since the intersection of a reconstructed sphere and an imaging plane is ideally a circle with an eccentricity of zero, the first metric presented compares the effective eccentricity of intersections of reconstructed volumes and imaging planes. As another metric of volumetric reconstruction fidelity, the volume of one of the contrasting spheres was determined using manual contouring. By comparing these manually delineated volumes with a CBCT reconstruction, we can gauge the volumetric fidelity of reconstructions. The configuration which yielded the highest overall volumetric reconstruction fidelity, as determined by effective eccentricities and volumetric contouring, consisted of two orthogonally-offset 60° L-arm sweeps and a single C-arm sweep which shared a pivot point with one the L-arm sweeps. When compared to a similar configuration that

  16. Aspects of volumetric efficiency measurement for reciprocating engines

    Directory of Open Access Journals (Sweden)

    Pešić Radivoje B.

    2013-01-01

    Full Text Available The volumetric efficiency significantly influences engine output. Both design and dimensions of an intake and exhaust system have large impact on volumetric efficiency. Experimental equipment for measuring of airflow through the engine, which is placed in the intake system, may affect the results of measurements and distort the real picture of the impact of individual structural factors. This paper deals with the problems of experimental determination of intake airflow using orifice plates and the influence of orifice plate diameter on the results of the measurements. The problems of airflow measurements through a multi-process Otto/Diesel engine were analyzed. An original method for determining volumetric efficiency was developed based on in-cylinder pressure measurement during motored operation, and appropriate calibration of the experimental procedure was performed. Good correlation between the results of application of the original method for determination of volumetric efficiency and the results of theoretical model used in research of influence of the intake pipe length on volumetric efficiency was determined. [Acknowledgments. The paper is the result of the research within the project TR 35041 financed by the Ministry of Science and Technological Development of the Republic of Serbia

  17. Sensitivity of quantitative groundwater recharge estimates to volumetric and distribution uncertainty in rainfall forcing products

    Science.gov (United States)

    Werner, Micha; Westerhoff, Rogier; Moore, Catherine

    2017-04-01

    constructed using the same base data and forced with the VCSN precipitation dataset. Results of the comparison of the rainfall products show that there are significant differences in precipitation volume between the forcing products; in the order of 20% at most points. Even more significant differences can be seen, however, in the distribution of precipitation. For the VCSN data wet days (defined as >0.1mm precipitation) occur on some 20-30% of days (depending on location). This is reasonably reflected in the TRMM and CHIRPS data, while for the re-analysis based products some 60%to 80% of days are wet, albeit at lower intensities. These differences are amplified in the recharge estimates. At most points, volumetric differences are in the order of 40-60%, though difference may range into several orders of magnitude. The frequency distributions of recharge also differ significantly, with recharge over 0.1 mm occurring on 4-6% of days for the VCNS, CHIRPS, and TRMM datasets, but up to the order of 12% of days for the re-analysis data. Comparison against the lysimeter data show estimates to be reasonable, in particular for the reference datasets. Surprisingly some estimates of the lower resolution re-analysis datasets are reasonable, though this does seem to be due to lower recharge being compensated by recharge occurring more frequently. These results underline the importance of correct representation of rainfall volumes, as well as of distribution, particularly when evaluating possible changes to for example changes in precipitation intensity and volume. This holds for precipitation data derived from satellite based and re-analysis products, but also for interpolated data from gauges, where the distribution of intensities is strongly influenced by the interpolation process.

  18. A high volume, high throughput volumetric sorption analyzer

    Science.gov (United States)

    Soo, Y. C.; Beckner, M.; Romanos, J.; Wexler, C.; Pfeifer, P.; Buckley, P.; Clement, J.

    2011-03-01

    In this talk we will present an overview of our new Hydrogen Test Fixture (HTF) constructed by the Midwest Research Institute for The Alliance for Collaborative Research in Alternative Fuel Technology to test activated carbon monoliths for hydrogen gas storage. The HTF is an automated, computer-controlled volumetric instrument for rapid screening and manipulation of monoliths under an inert atmosphere (to exclude degradation of carbon from exposure to oxygen). The HTF allows us to measure large quantity (up to 500 g) of sample in a 0.5 l test tank, making our results less sensitive to sample inhomogeneity. The HTF can measure isotherms at pressures ranging from 1 to 300 bar at room temperature. For comparison, other volumetric instruments such as Hiden Isochema's HTP-1 Volumetric Analyser can only measure carbon samples up to 150 mg at pressures up to 200 bar. Work supported by the US DOD Contract # N00164-08-C-GS37.

  19. Volumetric (3D) compressive sensing spectral domain optical coherence tomography.

    Science.gov (United States)

    Xu, Daguang; Huang, Yong; Kang, Jin U

    2014-11-01

    In this work, we proposed a novel three-dimensional compressive sensing (CS) approach for spectral domain optical coherence tomography (SD OCT) volumetric image acquisition and reconstruction. Instead of taking a spectral volume whose size is the same as that of the volumetric image, our method uses a sub set of the original spectral volume that is under-sampled in all three dimensions, which reduces the amount of spectral measurements to less than 20% of that required by the Shan-non/Nyquist theory. The 3D image is recovered from the under-sampled spectral data dimension-by-dimension using the proposed three-step CS reconstruction strategy. Experimental results show that our method can significantly reduce the sampling rate required for a volumetric SD OCT image while preserving the image quality.

  20. Characterization of hydrological responses to rainfall and volumetric coefficients on the event scale in rural catchments of the Iberian Peninsula

    Science.gov (United States)

    Taguas, Encarnación; Nadal-Romero, Estela; Ayuso, José L.; Casalí, Javier; Cid, Patricio; Dafonte, Jorge; Duarte, Antonio C.; Giménez, Rafael; Giráldez, Juan V.; Gómez-Macpherson, Helena; Gómez, José A.; González-Hidalgo, J. Carlos; Lucía, Ana; Mateos, Luciano; Rodríguez-Blanco, M. Luz; Schnabel, Susanne; Serrano-Muela, M. Pilar; Lana-Renault, Noemí; Mercedes Taboada-Castro, M.; Taboada-Castro, M. Teresa

    2016-04-01

    Analysis of storm rainfall-runoff data is essential to improve our understanding of catchment hydrology and to validate models supporting hydrological planning. In a context of climate change, statistical and process-based models are helpful to explore different scenarios which might be represented by simple parameters such as volumetric runoff coefficient. In this work, rainfall-runoff event datasets collected at 17 rural catchments in the Iberian Peninsula were studied. The objectives were: i) to describe hydrological patterns/variability of the relation rainfall-runoff; ii) to explore different methodologies to quantify representative volumetric runoff coefficients. Firstly, the criteria used to define an event were examined in order to standardize the analysis. Linear regression adjustments and statistics of the rainfall-runoff relations were examined to identify possible common patterns. In addition, a principal component analysis was applied to evaluate the variability among catchments based on their physical attributes. Secondly, runoff coefficients at event temporal scale were calculated following different methods. Median, mean, Hawkinś graphic method (Hawkins, 1993), reference values for engineering project of Prevert (TRAGSA, 1994) and the ratio of cumulated runoff and cumulated precipitation of the event that generated runoff (Rcum) were compared. Finally, the relations between the most representative volumetric runoff coefficients with the physical features of the catchments were explored using multiple linear regressions. The mean volumetric runoff coefficient in the studied catchments was 0.18, whereas the median was 0.15, both with variation coefficients greater than 100%. In 6 catchments, rainfall-runoff linear adjustments presented coefficient of determination greater than 0.60 (p hydrological response differences in the catchments. REFERENCES: Hawkins, R. H. (1993). Asymptotic determination of runoff curve numbers from data. J. Irrig. Drain. Eng

  1. Multiple sparse volumetric priors for distributed EEG source reconstruction.

    Science.gov (United States)

    Strobbe, Gregor; van Mierlo, Pieter; De Vos, Maarten; Mijović, Bogdan; Hallez, Hans; Van Huffel, Sabine; López, José David; Vandenberghe, Stefaan

    2014-10-15

    We revisit the multiple sparse priors (MSP) algorithm implemented in the statistical parametric mapping software (SPM) for distributed EEG source reconstruction (Friston et al., 2008). In the present implementation, multiple cortical patches are introduced as source priors based on a dipole source space restricted to a cortical surface mesh. In this note, we present a technique to construct volumetric cortical regions to introduce as source priors by restricting the dipole source space to a segmented gray matter layer and using a region growing approach. This extension allows to reconstruct brain structures besides the cortical surface and facilitates the use of more realistic volumetric head models including more layers, such as cerebrospinal fluid (CSF), compared to the standard 3-layered scalp-skull-brain head models. We illustrated the technique with ERP data and anatomical MR images in 12 subjects. Based on the segmented gray matter for each of the subjects, cortical regions were created and introduced as source priors for MSP-inversion assuming two types of head models. The standard 3-layered scalp-skull-brain head models and extended 4-layered head models including CSF. We compared these models with the current implementation by assessing the free energy corresponding with each of the reconstructions using Bayesian model selection for group studies. Strong evidence was found in favor of the volumetric MSP approach compared to the MSP approach based on cortical patches for both types of head models. Overall, the strongest evidence was found in favor of the volumetric MSP reconstructions based on the extended head models including CSF. These results were verified by comparing the reconstructed activity. The use of volumetric cortical regions as source priors is a useful complement to the present implementation as it allows to introduce more complex head models and volumetric source priors in future studies.

  2. Volumetric measurements of a spatially growing dust acoustic wave

    Science.gov (United States)

    Williams, Jeremiah D.

    2012-11-01

    In this study, tomographic particle image velocimetry (tomo-PIV) techniques are used to make volumetric measurements of the dust acoustic wave (DAW) in a weakly coupled dusty plasma system in an argon, dc glow discharge plasma. These tomo-PIV measurements provide the first instantaneous volumetric measurement of a naturally occurring propagating DAW. These measurements reveal over the measured volume that the measured wave mode propagates in all three spatial dimensional and exhibits the same spatial growth rate and wavelength in each spatial direction.

  3. Volumetric measurements of a spatially growing dust acoustic wave

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Jeremiah D. [Physics Department, Wittenberg University, Springfield, Ohio 45504 (United States)

    2012-11-15

    In this study, tomographic particle image velocimetry (tomo-PIV) techniques are used to make volumetric measurements of the dust acoustic wave (DAW) in a weakly coupled dusty plasma system in an argon, dc glow discharge plasma. These tomo-PIV measurements provide the first instantaneous volumetric measurement of a naturally occurring propagating DAW. These measurements reveal over the measured volume that the measured wave mode propagates in all three spatial dimensional and exhibits the same spatial growth rate and wavelength in each spatial direction.

  4. Volumetric Pricing of Agricultural Water Supplies: A Case Study

    Science.gov (United States)

    Griffin, Ronald C.; Perry, Gregory M.

    1985-07-01

    Models of water consumption by rice producers are conceptualized and then estimated using cross-sectional time series data obtained from 16 Texas canal operators for the years 1977-1982. Two alternative econometric models demonstrate that both volumetric and flat rate water charges are strongly and inversely related to agricultural water consumption. Nonprice conservation incentives accompanying flat rates are hypothesized to explain the negative correlation of flat rate charges and water consumption. Application of these results suggests that water supply organizations in the sample population converting to volumetric pricing will generally reduce water consumption.

  5. as the Strengthening Precipitates

    Science.gov (United States)

    Lu, Qi; Xu, Wei; van der Zwaag, Sybrand

    2014-12-01

    Generally, Laves phase and M23C6 are regarded as undesirable phases in creep-resistant steels due to their very high-coarsening rates and the resulting depletion of beneficial alloying elements from the matrix. In this study, a computational alloy design approach is presented to develop martensitic steels strengthened by Laves phase and/or M23C6, for which the coarsening rates are tailored such that they are at least one order of magnitude lower than those in existing alloys. Their volume fractions are optimized by tuning the chemical composition in parallel. The composition domain covering 10 alloying elements at realistic levels is searched by a genetic algorithm to explore the full potential of simultaneous maximization of the volume fraction and minimization of the precipitates coarsening rate. The calculations show that Co and W can drastically reduce the coarsening rate of Laves and M23C6 and yield high-volume fractions of precipitates. Mo on the other hand was shown to have a minimal effect on coarsening. The strengthening effects of Laves phase and M23C6 in the newly designed alloys are compared to existing counterparts, showing substantially higher precipitation-strengthening contributions especially after a long service time. New alloys were designed in which both Laves phase and M23C6 precipitates act as strengthening precipitates. Successfully combining MX and M23C6 was found to be impossible.

  6. Borehole Volumetric Strainmeters Detect Very Long-period Ocean Level Changes in Tokai Area

    Science.gov (United States)

    Takanami, T.; Linde, A. T.; Sacks, S. I.; Kitagawa, G.; Hirata, N.; Rydelek, P. A.

    2015-12-01

    We detected a clear very long-period strain signal with a predominant period of about 2 months in the data from Sacks-Evertson borehole volumetric strainmeters. These have been operated by the Japan Meteorological Agency (JMA) since 1976 in Tokai area, Japan, the area of an expected Tokai eartquake. Earth's surface is always influenced by natural force such as earth tide, air pressure, and precipitation as well as by human induced sources. In order to decompose into their components in the maximum likelihood estimation, state-space modeling (Takanami et al., 2013) is applied to the observed time series data for 15 months before and after the earthquake M6.5 that occurred on 11th August 2009 in Suruga Bay. In the analysis, the strain data are decomposed into trend, air pressure, earth tide, precipitation effects and observation noise. Clear long-period strain signals are seen in the normalized trend component time series. Time series data from JMA tide gages around Suruga Bay are similarly decomposed. Then spectral analyses are applied to the trend components for the same time interval. Comparison of amplitude peaks in spectra for both data sets show all have a peak at period of about 1464 hours. Thus strain changes may be influenced by very long-period ocean level changes; it is necessary to consider this possibility before attributing tectonic significance to such variations.

  7. Precipitating factors of asthma.

    Science.gov (United States)

    Lee, T H

    1992-01-01

    Asthma is characterised by bronchial hyperresponsiveness. This feature of the asthmatic diathesis predisposes patients to wheezing in response to a number of different factors. These precipitating factors include specific allergen acting via sensitised mediator cells through an IgE-dependent mechanism. There are irritants which may work through a non-specific manner, or stimuli such as exercise and hyperventilation, which probably also act through mediator release via a non-IgE-dependent manner. The mechanism whereby physical stimuli such as exercise induce bronchoconstriction is of interest, because it increases the context in which the mast cell may participate in acute asthmatic bronchoconstriction. Respiratory infections also commonly provoke asthma, especially in infants and may, indeed, precipitate the asthmatic state itself. Finally, drugs can often trigger asthma attacks and the mechanisms of asthma precipitated by non-steroidal anti-inflammatory drugs such as aspirin have been the subject of recent research.

  8. Degradable starch nanoparticle assisted ethanol precipitation of DNA.

    Science.gov (United States)

    Ip, Alexander C-F; Tsai, Tsung Hao; Khimji, Imran; Huang, Po-Jung Jimmy; Liu, Juewen

    2014-09-22

    Precipitation of DNA from a large volume of aqueous solution is an important step in many molecular biology and analytical chemistry experiments. Currently, this is mainly achieved by ethanol precipitation, where a long-term incubation (usually overnight) at low temperature of -20 to -80°C with high salt concentration is required. This method also requires a large quantity of DNA to form a visible pellet and was tested mainly for double-stranded DNA. To improve DNA precipitation, co-precipitating polymers such as linear polyacrylamide has been used. In this work, we report that starch nanoparticles (SNPs) can achieve convenient DNA precipitation at room temperature with a low salt concentration and short incubation time. This method requires as low as 0.01-0.1% SNPs and can precipitate both single- and double-stranded DNA of various lengths. The effect of salt concentration, pH and the crosslinking density of SNPs has been systematically studied. Compared to other types of precipitating agents, SNPs are highly biocompatible and can be degraded by a common enzyme (amylase). This work suggests a novel application of a bio-based material that is prepared in mass production.

  9. Inconsistency in precipitation measurements across Alaska and Yukon border

    Directory of Open Access Journals (Sweden)

    L. Scaff

    2015-07-01

    Full Text Available This study quantifies the inconsistency in gauge precipitation observations across the border of Alaska and Yukon. It analyses the precipitation measurements by the national standard gauges (NWS 8-in gauge and Nipher gauge, and the bias-corrected data to account for wind effect on the gauge catch, wetting loss and trace events. The bias corrections show a significant amount of errors in the gauge records due to the windy and cold environment in the northern areas of Alaska and Yukon. Monthly corrections increase solid precipitation by 135 % in January, 20 % for July at the Barter Island in Alaska, and about 31 % for January and 4 % for July at the Yukon stations. Regression analyses of the monthly precipitation data show a stronger correlation for the warm months (mainly rainfall than for cold month (mainly snowfall between the station pairs, and small changes in the precipitation relationship due to the bias corrections. Double mass curves also indicate changes in the cumulative precipitation over the study periods. This change leads to a smaller and inverted precipitation gradient across the border, representing a significant modification in the precipitation pattern over the northern region. Overall, this study discovers significant inconsistency in the precipitation measurements across the US and Canada border. This discontinuity is greater for snowfall than for rainfall, as gauge snowfall observations have large errors in the windy and cold conditions. This result will certainly impact regional, particularly cross borders, climate and hydrology investigations.

  10. Precipitation-Regulated Feedback

    Science.gov (United States)

    Voit, Mark

    2016-07-01

    Star formation in the central galaxies of galaxy clusters appears to be fueled by precipitation of cold clouds out of hot circumgalactic gas via thermal instability. I will present both observational and theoretical support for the precipitation mode in large galaxies and discuss how it can be implemented in cosmological simulations of galaxy evolution. Galaxy cluster cores are unique laboratories for studying the astrophysics of thermal instability and may be teaching us valuable lessons about how feedback works in galaxies spanning the entire mass spectrum.

  11. Space-Time Transfinite Interpolation of Volumetric Material Properties.

    Science.gov (United States)

    Sanchez, Mathieu; Fryazinov, Oleg; Adzhiev, Valery; Comninos, Peter; Pasko, Alexander

    2015-02-01

    The paper presents a novel technique based on extension of a general mathematical method of transfinite interpolation to solve an actual problem in the context of a heterogeneous volume modelling area. It deals with time-dependent changes to the volumetric material properties (material density, colour, and others) as a transformation of the volumetric material distributions in space-time accompanying geometric shape transformations such as metamorphosis. The main idea is to represent the geometry of both objects by scalar fields with distance properties, to establish in a higher-dimensional space a time gap during which the geometric transformation takes place, and to use these scalar fields to apply the new space-time transfinite interpolation to volumetric material attributes within this time gap. The proposed solution is analytical in its nature, does not require heavy numerical computations and can be used in real-time applications. Applications of this technique also include texturing and displacement mapping of time-variant surfaces, and parametric design of volumetric microstructures.

  12. 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...

  13. Automatic segmentation of pulmonary segments from volumetric chest CT scans.

    NARCIS (Netherlands)

    Rikxoort, E.M. van; Hoop, B. de; Vorst, S. van de; Prokop, M.; Ginneken, B. van

    2009-01-01

    Automated extraction of pulmonary anatomy provides a foundation for computerized analysis of computed tomography (CT) scans of the chest. A completely automatic method is presented to segment the lungs, lobes and pulmonary segments from volumetric CT chest scans. The method starts with lung segmenta

  14. Volumetric T-spline Construction Using Boolean Operations

    Science.gov (United States)

    2013-07-01

    15213, USA 2 Institute for Computational Engineering and Sciences, The University of Texas at Austin, Austin, TX 78712, USA 3 Department of Civil and...and S. Yau. Volumetric harmonic map. Communications in Information and Systems, 3(3):191–202, 2003. 12. C.A.R. Guerra . Simultaneous untangling and

  15. Volumetric motion quantification by 3D tissue phase mapped CMR

    Directory of Open Access Journals (Sweden)

    Lutz Anja

    2012-10-01

    Full Text Available Abstract Background The objective of this study was the quantification of myocardial motion from 3D tissue phase mapped (TPM CMR. Recent work on myocardial motion quantification by TPM has been focussed on multi-slice 2D acquisitions thus excluding motion information from large regions of the left ventricle. Volumetric motion assessment appears an important next step towards the understanding of the volumetric myocardial motion and hence may further improve diagnosis and treatments in patients with myocardial motion abnormalities. Methods Volumetric motion quantification of the complete left ventricle was performed in 12 healthy volunteers and two patients applying a black-blood 3D TPM sequence. The resulting motion field was analysed regarding motion pattern differences between apical and basal locations as well as for asynchronous motion pattern between different myocardial segments in one or more slices. Motion quantification included velocity, torsion, rotation angle and strain derived parameters. Results All investigated motion quantification parameters could be calculated from the 3D-TPM data. Parameters quantifying hypokinetic or asynchronous motion demonstrated differences between motion impaired and healthy myocardium. Conclusions 3D-TPM enables the gapless volumetric quantification of motion abnormalities of the left ventricle, which can be applied in future application as additional information to provide a more detailed analysis of the left ventricular function.

  16. Video-rate volumetric optical coherence tomography-based microangiography

    Science.gov (United States)

    Baran, Utku; Wei, Wei; Xu, Jingjiang; Qi, Xiaoli; Davis, Wyatt O.; Wang, Ruikang K.

    2016-04-01

    Video-rate volumetric optical coherence tomography (vOCT) is relatively young in the field of OCT imaging but has great potential in biomedical applications. Due to the recent development of the MHz range swept laser sources, vOCT has started to gain attention in the community. Here, we report the first in vivo video-rate volumetric OCT-based microangiography (vOMAG) system by integrating an 18-kHz resonant microelectromechanical system (MEMS) mirror with a 1.6-MHz FDML swept source operating at ˜1.3 μm wavelength. Because the MEMS scanner can offer an effective B-frame rate of 36 kHz, we are able to engineer vOMAG with a video rate up to 25 Hz. This system was utilized for real-time volumetric in vivo visualization of cerebral microvasculature in mice. Moreover, we monitored the blood perfusion dynamics during stimulation within mouse ear in vivo. We also discussed this system's limitations. Prospective MEMS-enabled OCT probes with a real-time volumetric functional imaging capability can have a significant impact on endoscopic imaging and image-guided surgery applications.

  17. Precipitation Reconstruction (PREC)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The PREC data set is an analysis of monthly precipitation constructed on a 2.5(o)lat/lon grid over the global for the period from 1948 to the present. The land...

  18. Reaction systems with precipitation

    Directory of Open Access Journals (Sweden)

    Marek Rogalski

    2015-04-01

    Full Text Available This article proposes expanding Reaction Systems of Ehrenfeucht and Rozenberg by incorporating precipitation reactions into it. This improves the computing power of Reaction Systems by allowing us to implement a stack. This addition enables us to implement a Deterministic Pushdown Automaton.

  19. Precipitation of Zn2Al LDH by urease enzyme.

    Science.gov (United States)

    Vial, Stephanie; Ghanbaja, Jaafar; Forano, Claude

    2006-01-21

    A biomineralization process based on the promotion of precipitating agent by the urea-urease enzymatic system is developed to prepare ZnAl layered double hydroxide materials and the effects of the enzymatic reaction parameters on the structural and textural properties of the materials are investigated on the basis of XRD and EM analysis.

  20. Oxygen- and Nitrogen-Enriched 3D Porous Carbon for Supercapacitors of High Volumetric Capacity.

    Science.gov (United States)

    Li, Jia; Liu, Kang; Gao, Xiang; Yao, Bin; Huo, Kaifu; Cheng, Yongliang; Cheng, Xiaofeng; Chen, Dongchang; Wang, Bo; Sun, Wanmei; Ding, Dong; Liu, Meilin; Huang, Liang

    2015-11-11

    Efficient utilization and broader commercialization of alternative energies (e.g., solar, wind, and geothermal) hinges on the performance and cost of energy storage and conversion systems. For now and in the foreseeable future, the combination of rechargeable batteries and electrochemical capacitors remains the most promising option for many energy storage applications. Porous carbonaceous materials have been widely used as an electrode for batteries and supercapacitors. To date, however, the highest specific capacitance of an electrochemical double layer capacitor is only ∼200 F/g, although a wide variety of synthetic approaches have been explored in creating optimized porous structures. Here, we report our findings in the synthesis of porous carbon through a simple, one-step process: direct carbonization of kelp in an NH3 atmosphere at 700 °C. The resulting oxygen- and nitrogen-enriched carbon has a three-dimensional structure with specific surface area greater than 1000 m(2)/g. When evaluated as an electrode for electrochemical double layer capacitors, the porous carbon structure demonstrated excellent volumetric capacitance (>360 F/cm(3)) with excellent cycling stability. This simple approach to low-cost carbonaceous materials with unique architecture and functionality could be a promising alternative to fabrication of porous carbon structures for many practical applications, including batteries and fuel cells.

  1. NEW DEVELOPMENT IN DOUBLE GLOW SURFACE ALLOYING TECHNOLOGY

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Several kinds of special alloys are produced on the surfaces of iron and steels by using double glow surface alloying technology. Surface Ni-Cr-Mo-Nb alloy,surface precipitation hardening high speed steel and surface precipitation hardening stainless steel are introduced.

  2. Directly Grown Nanostructured Electrodes for High Volumetric Energy Density Binder-Free Hybrid Supercapacitors: A Case Study of CNTs//Li4Ti5O12

    Science.gov (United States)

    Zuo, Wenhua; Wang, Chong; Li, Yuanyuan; Liu, Jinping

    2015-01-01

    Hybrid supercapacitor (HSC), which typically consists of a Li-ion battery electrode and an electric double-layer supercapacitor electrode, has been extensively investigated for large-scale applications such as hybrid electric vehicles, etc. Its application potential for thin-film downsized energy storage systems that always prefer high volumetric energy/power densities, however, has not yet been explored. Herein, as a case study, we develop an entirely binder-free HSC by using multiwalled carbon nanotube (MWCNT) network film as the cathode and Li4Ti5O12 (LTO) nanowire array as the anode and study the volumetric energy storage capability. Both the electrode materials are grown directly on carbon cloth current collector, ensuring robust mechanical/electrical contacts and flexibility. Our 3 V HSC device exhibits maximum volumetric energy density of ~4.38 mWh cm-3, much superior to those of previous supercapacitors based on thin-film electrodes fabricated directly on carbon cloth and even comparable to the commercial thin-film lithium battery. It also has volumetric power densities comparable to that of the commercial 5.5 V/100 mF supercapacitor (can be operated within 3 s) and has excellent cycling stability (~92% retention after 3000 cycles). The concept of utilizing binder-free electrodes to construct HSC for thin-film energy storage may be readily extended to other HSC electrode systems.

  3. On the complex conductivity signatures of calcite precipitation

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Yuxin; Hubbard, Susan; Williams, Kenneth Hurst; Ajo-Franklin, Jonathan

    2009-11-01

    Calcite is a mineral phase that frequently precipitates during subsurface remediation or geotechnical engineering processes. This precipitation can lead to changes in the overall behavior of the system, such as flow alternation and soil strengthening. Because induced calcite precipitation is typically quite variable in space and time, monitoring its distribution in the subsurface is a challenge. In this research, we conducted a laboratory column experiment to investigate the potential of complex conductivity as a mean to remotely monitor calcite precipitation. Calcite precipitation was induced in a glass bead (3 mm) packed column through abiotic mixing of CaCl{sub 2} and Na{sub 2}CO{sub 3} solutions. The experiment continued for 12 days with a constant precipitation rate of {approx}0.6 milimole/d. Visual observations and scanning electron microscopy imaging revealed two distinct phases of precipitation: an earlier phase dominated by well distributed, discrete precipitates and a later phase characterized by localized precipitate aggregation and associated pore clogging. Complex conductivity measurements exhibited polarization signals that were characteristic of both phases of calcite precipitation, with the precipitation volume and crystal size controlling the overall polarization magnitude and relaxation time constant. We attribute the observed responses to polarization at the electrical double layer surrounding calcite crystals. Our experiment illustrates the potential of electrical methods for characterizing the distribution and aggregation state of nonconductive minerals like calcite. Advancing our ability to quantify geochemical transformations using such noninvasive methods is expected to facilitate our understanding of complex processes associated with natural subsurface systems as well as processes induced through engineered treatments (such as environmental remediation and carbon sequestration).

  4. Uncertainties in Arctic Precipitation

    Science.gov (United States)

    Majhi, I.; Alexeev, V. A.; Cherry, J. E.; Cohen, J. L.; Groisman, P. Y.

    2012-12-01

    Arctic precipitation is riddled with measurement biases; to address the problem is imperative. Our study focuses on comparison of various datasets and analyzing their biases for the region of Siberia and caution that is needed when using them. Five sources of data were used ranging from NOAA's product (RAW, Bogdanova's correction), Yang's correction technique and two reanalysis products (ERA-Interim and NCEP). The reanalysis dataset performed better for some months in comparison to Yang's product, which tends to overestimate precipitation, and the raw dataset, which tends to underestimate. The sources of bias vary from topography, to wind, to missing data .The final three products chosen show higher biases during the winter and spring season. Emphasis on equations which incorporate blizzards, blowing snow and higher wind speed is necessary for regions which are influenced by any or all of these factors; Bogdanova's correction technique is the most robust of all the datasets analyzed and gives the most reasonable results. One of our future goals is to analyze the impact of precipitation uncertainties on water budget analysis for the Siberian Rivers.

  5. Hourly Precipitation Data (HPD) Publication

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Hourly Precipitation Data (HPD) Publication is archived and available from the National Climatic Data Center (NCDC). This publication contains hourly precipitation...

  6. Double supergeometry

    CERN Document Server

    Cederwall, Martin

    2016-01-01

    A geometry of superspace corresponding to double field theory is developed, with type II supergravity in D=10 as the main example. The formalism is based on an orthosymplectic extension OSp(d,d|2s) of the continuous T-duality group. Covariance under generalised super-diffeomorphisms is manifest. Ordinary superspace is obtained as a solution of the orthosymplectic section condition. A systematic study of curved superspace Bianchi identities is performed, and a relation to a double pure spinor superfield cohomology is established. A Ramond-Ramond superfield is constructed as an infinite-dimensional orthosymplectic spinor. Such objects in minimal orbits under the OSp supergroup ("pure spinors") define super-sections.

  7. Double screening

    Energy Technology Data Exchange (ETDEWEB)

    Gratia, Pierre [Department of Physics, University of Chicago,South Ellis Avenue, Chicago, IL 60637 (United States); Hu, Wayne [Department of Astronomy and Astrophysics, University of Chicago,South Ellis Avenue, Chicago, IL 60637 (United States); Enrico Fermi Institute and Kavli Institute for Cosmological Physics, University of Chicago,South Ellis Avenue, Chicago, IL 60637 (United States); Joyce, Austin [Enrico Fermi Institute and Kavli Institute for Cosmological Physics, University of Chicago,South Ellis Avenue, Chicago, IL 60637 (United States); Ribeiro, Raquel H. [School of Physics and Astronomy, Queen Mary University of London,Mile End Road, London, E1 4NS (United Kingdom)

    2016-06-15

    Attempts to modify gravity in the infrared typically require a screening mechanism to ensure consistency with local tests of gravity. These screening mechanisms fit into three broad classes; we investigate theories which are capable of exhibiting more than one type of screening. Specifically, we focus on a simple model which exhibits both Vainshtein and kinetic screening. We point out that due to the two characteristic length scales in the problem, the type of screening that dominates depends on the mass of the sourcing object, allowing for different phenomenology at different scales. We consider embedding this double screening phenomenology in a broader cosmological scenario and show that the simplest examples that exhibit double screening are radiatively stable.

  8. Pulse sequence for dynamic volumetric imaging of hyperpolarized metabolic products

    Science.gov (United States)

    Cunningham, Charles H.; Chen, Albert P.; Lustig, Michael; Hargreaves, Brian A.; Lupo, Janine; Xu, Duan; Kurhanewicz, John; Hurd, Ralph E.; Pauly, John M.; Nelson, Sarah J.; Vigneron, Daniel B.

    2008-07-01

    Dynamic nuclear polarization and dissolution of a 13C-labeled substrate enables the dynamic imaging of cellular metabolism. Spectroscopic information is typically acquired, making the acquisition of dynamic volumetric data a challenge. To enable rapid volumetric imaging, a spectral-spatial excitation pulse was designed to excite a single line of the carbon spectrum. With only a single resonance present in the signal, an echo-planar readout trajectory could be used to resolve spatial information, giving full volume coverage of 32 × 32 × 16 voxels every 3.5 s. This high frame rate was used to measure the different lactate dynamics in different tissues in a normal rat model and a mouse model of prostate cancer.

  9. Nonrigid registration of volumetric images using ranked order statistics

    DEFF Research Database (Denmark)

    Tennakoon, Ruwan; Bab-Hadiashar, Alireza; Cao, Zhenwei

    2014-01-01

    Non-rigid image registration techniques using intensity based similarity measures are widely used in medical imaging applications. Due to high computational complexities of these techniques, particularly for volumetric images, finding appropriate registration methods to both reduce the computation...... burden and increase the registration accuracy has become an intensive area of research. In this paper we propose a fast and accurate non-rigid registration method for intra-modality volumetric images. Our approach exploits the information provided by an order statistics based segmentation method, to find...... the important regions for registration and use an appropriate sampling scheme to target those areas and reduce the registration computation time. A unique advantage of the proposed method is its ability to identify the point of diminishing returns and stop the registration process. Our experiments...

  10. Volumetric characterization of delamination fields via angle longitudinal wave ultrasound

    Science.gov (United States)

    Wertz, John; Wallentine, Sarah; Welter, John; Dierken, Josiah; Aldrin, John

    2017-02-01

    The volumetric characterization of delaminations necessarily precedes rigorous composite damage progression modeling. Yet, inspection of composite structures for subsurface damage remains largely focused on detection, resulting in a capability gap. In response to this need, angle longitudinal wave ultrasound was employed to characterize a composite surrogate containing a simulated three-dimensional delamination field with distinct regions of occluded features (shadow regions). Simple analytical models of the specimen were developed to guide subsequent experimentation through identification of optimal scanning parameters. The ensuing experiments provided visual evidence of the complete delamination field, including indications of features within the shadow regions. The results of this study demonstrate proof-of-principle for the use of angle longitudinal wave ultrasonic inspection for volumetric characterization of three-dimensional delamination fields. Furthermore, the techniques developed herein form the foundation of succeeding efforts to characterize impact delaminations within inhomogeneous laminar materials such as polymer matrix composites.

  11. Magnetic Resonance Image Segmentation and its Volumetric Measurement

    Directory of Open Access Journals (Sweden)

    Rahul R. Ambalkar

    2013-02-01

    Full Text Available Image processing techniques make it possible to extract meaningful information from medical images. Magnetic resonance (MR imaging has been widely applied in biological research and diagnostics because of its excellent soft tissue contrast, non-invasive character, high spatial resolution and easy slice selection at any orientation. The MRI-based brain volumetric is concerned with the analysis of volumes and shapes of the structural components of the human brain. It also provides a criterion, by which we recognize the presence of degenerative diseases and characterize their rates of progression to make the diagnosis and treatments as a easy task. In this paper we have proposed an automated method for volumetric measurement of Magnetic Resonance Imaging and used Self Organized Map (SOM clustering method for their segmentations. We have used the MRI data set of 61 slices of 256×256 pixels in DICOM standard format

  12. 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

    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...... 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...... 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...

  13. In Vivo Real Time Volumetric Synthetic Aperture Ultrasound Imaging

    DEFF Research Database (Denmark)

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

    2015-01-01

    . 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......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...... 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...

  14. COMPARISON OF VOLUMETRIC REGISTRATION ALGORITHMS FOR TENSOR-BASED MORPHOMETRY

    Science.gov (United States)

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

    2015-01-01

    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. PMID:26925198

  15. Modeling solid-state precipitation

    CERN Document Server

    Nebylov, AlexanderKozeschnik, Ernst

    2012-01-01

    Over recent decades, modeling and simulation of solid-state precipitation has attracted increased attention in academia and industry due to their important contributions in designing properties of advanced structural materials and in increasing productivity and decreasing costs for expensive alloying. In particular, precipitation of second phases is an important means for controlling the mechanical-technological properties of structural materials. However, profound physical modeling of precipitation is not a trivial task. This book introduces you to the classical methods of precipitation model

  16. 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.

  17. Using surface heave to estimate reservoir volumetric strain

    Energy Technology Data Exchange (ETDEWEB)

    Nanayakkara, A.S.; Wong, R.C.K. [Calgary Univ., AB (Canada)

    2008-07-01

    This paper presented a newly developed numerical tool for estimating reservoir volumetric strain distribution using surface vertical displacements and solving an inverse problem. Waterflooding, steam injection, carbon dioxide sequestration and aquifer storage recovery are among the subsurface injection operations that are responsible for reservoir dilations which propagate to the surrounding formations and extend to the surface resulting in surface heaves. Global positioning systems and surface tiltmeters are often used to measure the characteristics of these surface heaves and to derive valuable information regarding reservoir deformation and flow characteristics. In this study, Tikhonov regularization techniques were adopted to solve the ill-posed inversion problem commonly found in standard inversion techniques such as Gaussian elimination and least squares methods. Reservoir permeability was then estimated by inverting the volumetric strain distribution. Results of the newly developed numerical tool were compared with results from fully-coupled finite element simulation of fluid injection problems. The reservoir volumetric strain distribution was successfully estimated along with an approximate value for reservoir permeability.

  18. Volumetric Light-field Encryption at the Microscopic Scale

    Science.gov (United States)

    Li, Haoyu; Guo, Changliang; Muniraj, Inbarasan; Schroeder, Bryce C.; Sheridan, John T.; Jia, Shu

    2017-01-01

    We report a light-field based method that allows the optical encryption of three-dimensional (3D) volumetric information at the microscopic scale in a single 2D light-field image. The system consists of a microlens array and an array of random phase/amplitude masks. The method utilizes a wave optics model to account for the dominant diffraction effect at this new scale, and the system point-spread function (PSF) serves as the key for encryption and decryption. We successfully developed and demonstrated a deconvolution algorithm to retrieve both spatially multiplexed discrete data and continuous volumetric data from 2D light-field images. Showing that the method is practical for data transmission and storage, we obtained a faithful reconstruction of the 3D volumetric information from a digital copy of the encrypted light-field image. The method represents a new level of optical encryption, paving the way for broad industrial and biomedical applications in processing and securing 3D data at the microscopic scale.

  19. Volumetric Light-field Encryption at the Microscopic Scale

    Science.gov (United States)

    Li, Haoyu; Guo, Changliang; Muniraj, Inbarasan; Schroeder, Bryce C.; Sheridan, John T.; Jia, Shu

    2017-01-01

    We report a light-field based method that allows the optical encryption of three-dimensional (3D) volumetric information at the microscopic scale in a single 2D light-field image. The system consists of a microlens array and an array of random phase/amplitude masks. The method utilizes a wave optics model to account for the dominant diffraction effect at this new scale, and the system point-spread function (PSF) serves as the key for encryption and decryption. We successfully developed and demonstrated a deconvolution algorithm to retrieve both spatially multiplexed discrete data and continuous volumetric data from 2D light-field images. Showing that the method is practical for data transmission and storage, we obtained a faithful reconstruction of the 3D volumetric information from a digital copy of the encrypted light-field image. The method represents a new level of optical encryption, paving the way for broad industrial and biomedical applications in processing and securing 3D data at the microscopic scale. PMID:28059149

  20. Volumetric Light-field Encryption at the Microscopic Scale

    CERN Document Server

    Li, Haoyu; Muniraj, Inbarasan; Schroeder, Bryce C; Sheridan, John T; Jia, Shu

    2016-01-01

    We report a light-field based method that allows the optical encryption of three-dimensional (3D) volumetric information at the microscopic scale in a single 2D light-field image. The system consists of a microlens array and an array of random phase/amplitude masks. The method utilizes a wave optics model to account for the dominant diffraction effect at this new scale, and the system point-spread function (PSF) serves as the key for encryption and decryption. We successfully developed and demonstrated a deconvolution algorithm to retrieve spatially multiplexed discrete and continuous volumetric data from 2D light-field images. Showing that the method is practical for data transmission and storage, we obtained a faithful reconstruction of the 3D volumetric information from a digital copy of the encrypted light-field image. The method represents a new level of optical encryption, paving the way for broad industrial and biomedical applications in processing and securing 3D data at the microscopic scale.

  1. Volumetric Light-field Encryption at the Microscopic Scale.

    Science.gov (United States)

    Li, Haoyu; Guo, Changliang; Muniraj, Inbarasan; Schroeder, Bryce C; Sheridan, John T; Jia, Shu

    2017-01-06

    We report a light-field based method that allows the optical encryption of three-dimensional (3D) volumetric information at the microscopic scale in a single 2D light-field image. The system consists of a microlens array and an array of random phase/amplitude masks. The method utilizes a wave optics model to account for the dominant diffraction effect at this new scale, and the system point-spread function (PSF) serves as the key for encryption and decryption. We successfully developed and demonstrated a deconvolution algorithm to retrieve both spatially multiplexed discrete data and continuous volumetric data from 2D light-field images. Showing that the method is practical for data transmission and storage, we obtained a faithful reconstruction of the 3D volumetric information from a digital copy of the encrypted light-field image. The method represents a new level of optical encryption, paving the way for broad industrial and biomedical applications in processing and securing 3D data at the microscopic scale.

  2. Relative effects of precipitation variability and warming on grassland ecosystem function

    Directory of Open Access Journals (Sweden)

    P. A. Fay

    2011-07-01

    Full Text Available Precipitation and temperature drive many aspects of terrestrial ecosystem function. Climate change scenarios predict increasing precipitation variability and temperature, and long term experiments are required to evaluate the ecosystem consequences of interannual climate variation, increased growing season (intra-annual rainfall variability, and warming. We present results from an experiment applying increased growing season rainfall variability and year round warming in native perennial grassland. During ten years of study, total growing season rainfall varied 2-fold, and we found ~50–200 % interannual variability in plant growth and aboveground net primary productivity, leaf carbon assimilation (ACO2, and soil CO2 efflux (JCO2 despite only ∼40 % variation in mean volumetric soil water content (0–15 cm, Θ15. Interannual variation in soil moisture was thus amplified in most measures of ecosystem response. Differences between years in Θ15 explained the greatest portion (14–52 % of the variation in these processes. Experimentally increased intra-annual rainfall variability doubled the amplitude of intra-annual soil moisture variation and reduced Θ15 by 15 %, causing most ecosystem processes to decrease 8–40 % in some or all years with increased rainfall variability compared to ambient rainfall timing, suggesting reduced ecosystem rainfall use efficiency. Warming treatments increased 5 cm soil temperature, particularly during spring, fall, and winter. Warming advanced canopy green up in spring, increased winter JCO2, and reduced summer JCO2 and forb ANPP, suggesting that the effects of warming differed in cooler versus warmer parts of the year. We conclude that (1 major ecosystem processes in this grassland may be substantially altered by predicted changes in interannual climate variability, intra

  3. Relative effects of precipitation variability and warming on tallgrass prairie ecosystem function

    Directory of Open Access Journals (Sweden)

    P. A. Fay

    2011-10-01

    Full Text Available Precipitation and temperature drive many aspects of terrestrial ecosystem function. Climate change scenarios predict increasing precipitation variability and temperature, and long term experiments are required to evaluate the ecosystem consequences of interannual climate variation, increased growing season (intra-annual rainfall variability, and warming. We present results from an experiment applying increased growing season rainfall variability and year round warming in native tallgrass prairie. During ten years of study, total growing season rainfall varied 2-fold, and we found ~50–200% interannual variability in plant growth and aboveground net primary productivity (ANPP, leaf carbon assimilation (ACO2, and soil CO2 efflux (JCO2 despite only ~40% variation in mean volumetric soil water content (0–15 cm, Θ15. Interannual variation in soil moisture was thus amplified in most measures of ecosystem response. Differences between years in Θ15 explained the greatest portion (14–52% of the variation in these processes. Experimentally increased intra-annual season rainfall variability doubled the amplitude of intra-annual soil moisture variation and reduced Θ15 by 15%, causing most ecosystem processes to decrease 8–40% in some or all years with increased rainfall variability compared to ambient rainfall timing, suggesting reduced ecosystem rainfall use efficiency. Warming treatments increased soil temperature at 5 cm depth, particularly during spring, fall, and winter. Warming advanced canopy green up in spring, increased winter JCO2, and reduced summer JCO2 and forb ANPP, suggesting that the effects of warming differed in cooler versus warmer parts of the year. We conclude that (1 major ecosystem processes in this grassland may be substantially altered by predicted changes in

  4. Spatial downscaling of precipitation using adaptable random forests

    Science.gov (United States)

    He, Xiaogang; Chaney, Nathaniel W.; Schleiss, Marc; Sheffield, Justin

    2016-10-01

    This paper introduces Prec-DWARF (Precipitation Downscaling With Adaptable Random Forests), a novel machine-learning based method for statistical downscaling of precipitation. Prec-DWARF sets up a nonlinear relationship between precipitation at fine resolution and covariates at coarse/fine resolution, based on the advanced binary tree method known as Random Forests (RF). In addition to a single RF, we also consider a more advanced implementation based on two independent RFs which yield better results for extreme precipitation. Hourly gauge-radar precipitation data at 0.125° from NLDAS-2 are used to conduct synthetic experiments with different spatial resolutions (0.25°, 0.5°, and 1°). Quantitative evaluation of these experiments demonstrates that Prec-DWARF consistently outperforms the baseline (i.e., bilinear interpolation in this case) and can reasonably reproduce the spatial and temporal patterns, occurrence and distribution of observed precipitation fields. However, Prec-DWARF with a single RF significantly underestimates precipitation extremes and often cannot correctly recover the fine-scale spatial structure, especially for the 1° experiments. Prec-DWARF with a double RF exhibits improvement in the simulation of extreme precipitation as well as its spatial and temporal structures, but variogram analyses show that the spatial and temporal variability of the downscaled fields are still strongly underestimated. Covariate importance analysis shows that the most important predictors for the downscaling are the coarse-scale precipitation values over adjacent grid cells as well as the distance to the closest dry grid cell (i.e., the dry drift). The encouraging results demonstrate the potential of Prec-DWARF and machine-learning based techniques in general for the statistical downscaling of precipitation.

  5. Double Imbalance

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The government has been introducing a string of policies to stabilize the economy and cushion the impact of the global eco-nomic slowdown since October.These policies are generally deemed"timely"and"necessary,"but not a long-term cure for problems in China’s economy.Renowned economist Wu Jinglian says the country must address its"double imbalance"and further reform its economic growth mode.He made his comments at the First Annual Global Management Forum on December 6 in Shanghai.Excerptsf ollow:

  6. The Global Precipitation Climatology Project (GPCP) Combined Precipitation Dataset

    Science.gov (United States)

    Huffman, George J.; Adler, Robert F.; Arkin, Philip; Chang, Alfred; Ferraro, Ralph; Gruber, Arnold; Janowiak, John; McNab, Alan; Rudolf, Bruno; Schneider, Udo

    1997-01-01

    The Global Precipitation Climatology Project (GPCP) has released the GPCP Version 1 Combined Precipitation Data Set, a global, monthly precipitation dataset covering the period July 1987 through December 1995. The primary product in the dataset is a merged analysis incorporating precipitation estimates from low-orbit-satellite microwave data, geosynchronous-orbit -satellite infrared data, and rain gauge observations. The dataset also contains the individual input fields, a combination of the microwave and infrared satellite estimates, and error estimates for each field. The data are provided on 2.5 deg x 2.5 deg latitude-longitude global grids. Preliminary analyses show general agreement with prior studies of global precipitation and extends prior studies of El Nino-Southern Oscillation precipitation patterns. At the regional scale there are systematic differences with standard climatologies.

  7. 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.

  8. Personalized heterogeneous deformable model for fast volumetric registration.

    Science.gov (United States)

    Si, Weixin; Liao, Xiangyun; Wang, Qiong; Heng, Pheng Ann

    2017-02-20

    Biomechanical deformable volumetric registration can help improve safety of surgical interventions by ensuring the operations are extremely precise. However, this technique has been limited by the accuracy and the computational efficiency of patient-specific modeling. This study presents a tissue-tissue coupling strategy based on penalty method to model the heterogeneous behavior of deformable body, and estimate the personalized tissue-tissue coupling parameters in a data-driven way. Moreover, considering that the computational efficiency of biomechanical model is highly dependent on the mechanical resolution, a practical coarse-to-fine scheme is proposed to increase runtime efficiency. Particularly, a detail enrichment database is established in an offline fashion to represent the mapping relationship between the deformation results of high-resolution hexahedral mesh extracted from the raw medical data and a newly constructed low-resolution hexahedral mesh. At runtime, the mechanical behavior of human organ under interactions is simulated with this low-resolution hexahedral mesh, then the microstructures are synthesized in virtue of the detail enrichment database. The proposed method is validated by volumetric registration in an abdominal phantom compression experiments. Our personalized heterogeneous deformable model can well describe the coupling effects between different tissues of the phantom. Compared with high-resolution heterogeneous deformable model, the low-resolution deformable model with our detail enrichment database can achieve 9.4× faster, and the average target registration error is 3.42 mm, which demonstrates that the proposed method shows better volumetric registration performance than state-of-the-art. Our framework can well balance the precision and efficiency, and has great potential to be adopted in the practical augmented reality image-guided robotic systems.

  9. Volumetric measurements of pulmonary nodules: variability in automated analysis tools

    Science.gov (United States)

    Juluru, Krishna; Kim, Woojin; Boonn, William; King, Tara; Siddiqui, Khan; Siegel, Eliot

    2007-03-01

    Over the past decade, several computerized tools have been developed for detection of lung nodules and for providing volumetric analysis. Incidentally detected lung nodules have traditionally been followed over time by measurements of their axial dimensions on CT scans to ensure stability or document progression. A recently published article by the Fleischner Society offers guidelines on the management of incidentally detected nodules based on size criteria. For this reason, differences in measurements obtained by automated tools from various vendors may have significant implications on management, yet the degree of variability in these measurements is not well understood. The goal of this study is to quantify the differences in nodule maximum diameter and volume among different automated analysis software. Using a dataset of lung scans obtained with both "ultra-low" and conventional doses, we identified a subset of nodules in each of five size-based categories. Using automated analysis tools provided by three different vendors, we obtained size and volumetric measurements on these nodules, and compared these data using descriptive as well as ANOVA and t-test analysis. Results showed significant differences in nodule maximum diameter measurements among the various automated lung nodule analysis tools but no significant differences in nodule volume measurements. These data suggest that when using automated commercial software, volume measurements may be a more reliable marker of tumor progression than maximum diameter. The data also suggest that volumetric nodule measurements may be relatively reproducible among various commercial workstations, in contrast to the variability documented when performing human mark-ups, as is seen in the LIDC (lung imaging database consortium) study.

  10. Precipitation extremes under climate change

    CERN Document Server

    O'Gorman, Paul A

    2015-01-01

    The response of precipitation extremes to climate change is considered using results from theory, modeling, and observations, with a focus on the physical factors that control the response. Observations and simulations with climate models show that precipitation extremes intensify in response to a warming climate. However, the sensitivity of precipitation extremes to warming remains uncertain when convection is important, and it may be higher in the tropics than the extratropics. Several physical contributions govern the response of precipitation extremes. The thermodynamic contribution is robust and well understood, but theoretical understanding of the microphysical and dynamical contributions is still being developed. Orographic precipitation extremes and snowfall extremes respond differently from other precipitation extremes and require particular attention. Outstanding research challenges include the influence of mesoscale convective organization, the dependence on the duration considered, and the need to...

  11. Volumetric hemispheric ratio as a useful tool in personality psychology.

    Science.gov (United States)

    Montag, Christian; Schoene-Bake, Jan-Christoph; Wagner, Jan; Reuter, Martin; Markett, Sebastian; Weber, Bernd; Quesada, Carlos M

    2013-02-01

    The present study investigates the link between volumetric hemispheric ratios (VHRs) and personality measures in N=267 healthy participants using Eysenck's Personality Inventory-Revised (EPQ-R) and the BIS/BAS scales. A robust association between extraversion and VHRs was observed for gray matter in males but not females. Higher gray matter volume in the left than in the right hemisphere was associated with higher extraversion in males. The results are discussed in the context of positive emotionality and laterality of the human brain.

  12. AN ATTRIBUTION OF CAVITATION RESONANCE: VOLUMETRIC OSCILLATIONS OF CLOUD

    Institute of Scientific and Technical Information of China (English)

    ZUO Zhi-gang; LI Sheng-cai; LIU Shu-hong; LI Shuang; CHEN Hui

    2009-01-01

    In order to further verify the proposed theory of cavitation resonance, as well as to proceed the investigations into microscopic level, a series of studies are being carried out on the Warwick venturi. The analysis of the oscillation characteristics of the cavitation resonance has conclusively verified the macro-mechanism proposed through previous studies on other cavitating flows by the authors. The initial observations using high-speed photographic approach have revealed a new attribution of cavitation resonance. That is, the volumetric oscillation of cavitation cloud is associated with the cavitation resonance, which is a collective behaviour of the bubbles in the cloud.

  13. 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.

  14. 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

  15. Estimation of volumetric breast density for breast cancer risk prediction

    Science.gov (United States)

    Pawluczyk, Olga; Yaffe, Martin J.; Boyd, Norman F.; Jong, Roberta A.

    2000-04-01

    Mammographic density (MD) has been shown to be a strong risk predictor for breast cancer. Compared to subjective assessment by a radiologist, computer-aided analysis of digitized mammograms provides a quantitative and more reproducible method for assessing breast density. However, the current methods of estimating breast density based on the area of bright signal in a mammogram do not reflect the true, volumetric quantity of dense tissue in the breast. A computerized method to estimate the amount of radiographically dense tissue in the overall volume of the breast has been developed to provide an automatic, user-independent tool for breast cancer risk assessment. The procedure for volumetric density estimation consists of first correcting the image for inhomogeneity, then performing a volume density calculation. First, optical sensitometry is used to convert all images to the logarithm of relative exposure (LRE), in order to simplify the image correction operations. The field non-uniformity correction, which takes into account heel effect, inverse square law, path obliquity and intrinsic field and grid non- uniformity is obtained by imaging a spherical section PMMA phantom. The processed LRE image of the phantom is then used as a correction offset for actual mammograms. From information about the thickness and placement of the breast, as well as the parameters of a breast-like calibration step wedge placed in the mammogram, MD of the breast is calculated. Post processing and a simple calibration phantom enable user- independent, reliable and repeatable volumetric estimation of density in breast-equivalent phantoms. Initial results obtained on known density phantoms show the estimation to vary less than 5% in MD from the actual value. This can be compared to estimated mammographic density differences of 30% between the true and non-corrected values. Since a more simplistic breast density measurement based on the projected area has been shown to be a strong indicator

  16. 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

  17. Lectins in extracts of certain Polygonaceae seed precipitate animal and human serums.

    Science.gov (United States)

    Hanan, E B; Spindler, J W

    1968-06-28

    Seeds of four species of Polygonaceae were tested for lectins that precipitate human and animal serums. Rumex crispus, Polygonum convolvulus, and Polygonum pennsylvanicum developed specific precipitate bands on double diffusion on agar gel plates. These bands were enhanced and increased in number when extracts were tested against serums from patients with certain diseases. When tested against lyophilized serum, no precipitate bands developed. The active substance cannot be dialyzed through cellulose membrane against running tap water for 16 hours, and it is heat stable. Extracts from Fagopyrum esculentum developed no precipitate bands.

  18. Effective Assimilation of Global Precipitation

    Science.gov (United States)

    Lien, G.; Kalnay, E.; Miyoshi, T.; Huffman, G. J.

    2012-12-01

    Assimilating precipitation observations by modifying the moisture and sometimes temperature profiles has been shown successful in forcing the model precipitation to be close to the observed precipitation, but only while the assimilation is taking place. After the forecast start, the model tends to "forget" the assimilation changes and lose their extra skill after few forecast hours. This suggests that this approach is not an efficient way to modify the potential vorticity field, since this is the variable that the model would remember. In this study, the ensemble Kalman filter (EnKF) method is used to effectively change the potential vorticity field by allowing ensemble members with better precipitation to receive higher weights. In addition to using an EnKF, two other changes in the precipitation assimilation process are proposed to solve the problems related to the highly non-Gaussian nature of the precipitation variable: a) transform precipitation into a Gaussian distribution based on its climatological distribution, and b) only assimilate precipitation at the location where some ensemble members have positive precipitation. The idea is first tested by the observing system simulation experiments (OSSEs) using SPEEDY, a simplified but realistic general circulation model. When the global precipitation is assimilated in addition to conventional rawinsonde observations, both the analyses and the medium range forecasts are significantly improved as compared to only having rawinsonde observations. The improvement is much reduced when only modifying the moisture field with the same approach, which shows the importance of the error covariance between precipitation and all other model variables. The effect of precipitation assimilation is larger in the Southern Hemisphere than that in the Northern Hemisphere because the Northern Hemisphere analyses are already accurate as a result of denser rawinsonde stations. Assimilation of precipitation using a more comprehensive

  19. Electrical operation of electrostatic precipitators

    CERN Document Server

    Parker, Ken

    2003-01-01

    The electrostatic precipitator remains on of the most cost effective means of controlling the emission of particulates from most industrial processes. This book will be of interest to both users and suppliers of electrostatic precipitators as well as advanced students on environmental based courses. The author identifies the physical and engineering basis for the development of electrical equipment for electrostatic precipitators and thoroughly explores the technological factors which optimize the efficiency of the precipitator and hence minimize emissions, as well as future developments in th

  20. Floating volumetric image formation using a dihedral corner reflector array device.

    Science.gov (United States)

    Miyazaki, Daisuke; Hirano, Noboru; Maeda, Yuki; Yamamoto, Siori; Mukai, Takaaki; Maekawa, Satoshi

    2013-01-01

    A volumetric display system using an optical imaging device consisting of numerous dihedral corner reflectors placed perpendicular to the surface of a metal plate is proposed. Image formation by the dihedral corner reflector array (DCRA) is free from distortion and focal length. In the proposed volumetric display system, a two-dimensional real image is moved by a mirror scanner to scan a three-dimensional (3D) space. Cross-sectional images of a 3D object are displayed in accordance with the position of the image plane. A volumetric image is observed as a stack of the cross-sectional images. The use of the DCRA brings compact system configuration and volumetric real image generation with very low distortion. An experimental volumetric display system including a DCRA, a galvanometer mirror, and a digital micro-mirror device was constructed to verify the proposed method. A volumetric image consisting of 1024×768×400 voxels was formed by the experimental system.

  1. Collimator angle influence on dose distribution optimization for vertebral metastases using volumetric modulated arc therapy

    Energy Technology Data Exchange (ETDEWEB)

    Mancosu, Pietro; Cozzi, Luca; Fogliata, Antonella; Lattuada, Paola; Reggiori, Giacomo; Cantone, Marie Claire; Navarria, Pierina; Scorsetti, Marta [Department of Radiation Oncology, IRCCS Istituto Clinico Humanitas, Milano (Rozzano) 20089 (Italy); Medical Physics Unit, Oncology Institute of Southern Switzerland, Bellinzona 6504 (Switzerland); Department of Radiation Oncology, IRCCS Istituto Clinico Humanitas, Milano (Rozzano) 20089 (Italy); Department of Physics, Universita Degli Studi di Milano, Milano 20133 (Italy); Department of Radiation Oncology, IRCCS Istituto Clinico Humanitas, Milano (Rozzano) 20089 (Italy)

    2010-08-15

    Purpose: The cylindrical symmetry of vertebrae favors the use of volumetric modulated arc therapy in generating a dose ''hole'' on the center of the vertebrae limiting the dose to the spinal cord. The authors have evaluated if collimator angle is a significant parameter for dose distribution optimization in vertebral metastases. Methods: Three patients with one-three vertebrae involved were considered. Twenty-one differently optimized plans (nine single-arc and 12 double-arc plans) were performed, testing various collimator angle positions. Clinical target volume was defined as the whole vertebrae, excluding the spinal cord canal. The planning target volume (PTV) was defined as CTV+5 mm. Dose prescription was 5x4 Gy{sup 2} with normalization to PTV mean dose. The dose at 1 cm{sup 3} of spinal cord was limited to 11.5Gy. Results: The best plans in terms of target coverage and spinal cord sparing were achieved by two arcs and Arc1-80 deg. and Arc2-280 deg. collimator angles for all the cases considered (i.e., leaf travel parallel to the spinal cord primary orientation). If one arc is used, only 80 deg. reached the objectives. Conclusions: This study demonstrated the role of collimation rotation for the vertebrae metastasis irradiation, with the leaf travel parallel to the spinal cord primary orientation to be better than other solutions. Thus, optimal choice of collimator angle increases the optimization freedom to shape a desired dose distribution.

  2. Rising Precipitation Extremes across Nepal

    Directory of Open Access Journals (Sweden)

    Ramchandra Karki

    2017-01-01

    Full Text Available As a mountainous country, Nepal is most susceptible to precipitation extremes and related hazards, including severe floods, landslides and droughts that cause huge losses of life and property, impact the Himalayan environment, and hinder the socioeconomic development of the country. Given that the countrywide assessment of such extremes is still lacking, we present a comprehensive picture of prevailing precipitation extremes observed across Nepal. First, we present the spatial distribution of daily extreme precipitation indices as defined by the Expert Team on Climate Change Detection, Monitoring and Indices (ETCCDMI from 210 stations over the period of 1981–2010. Then, we analyze the temporal changes in the computed extremes from 76 stations, featuring long-term continuous records for the period of 1970–2012, by applying a non-parametric Mann−Kendall test to identify the existence of a trend and Sen’s slope method to calculate the true magnitude of this trend. Further, the local trends in precipitation extremes have been tested for their field significance over the distinct physio-geographical regions of Nepal, such as the lowlands, middle mountains and hills and high mountains in the west (WL, WM and WH, respectively, and likewise, in central (CL, CM and CH and eastern (EL, EM and EH Nepal. Our results suggest that the spatial patterns of high-intensity precipitation extremes are quite different to that of annual or monsoonal precipitation. Lowlands (Terai and Siwaliks that feature relatively low precipitation and less wet days (rainy days are exposed to high-intensity precipitation extremes. Our trend analysis suggests that the pre-monsoonal precipitation is significantly increasing over the lowlands and CH, while monsoonal precipitation is increasing in WM and CH and decreasing in CM, CL and EL. On the other hand, post-monsoonal precipitation is significantly decreasing across all of Nepal while winter precipitation is decreasing

  3. Volumetric display containing multiple two-dimensional color motion pictures

    Science.gov (United States)

    Hirayama, R.; Shiraki, A.; Nakayama, H.; Kakue, T.; Shimobaba, T.; Ito, T.

    2014-06-01

    We have developed an algorithm which can record multiple two-dimensional (2-D) gradated projection patterns in a single three-dimensional (3-D) object. Each recorded pattern has the individual projected direction and can only be seen from the direction. The proposed algorithm has two important features: the number of recorded patterns is theoretically infinite and no meaningful pattern can be seen outside of the projected directions. In this paper, we expanded the algorithm to record multiple 2-D projection patterns in color. There are two popular ways of color mixing: additive one and subtractive one. Additive color mixing used to mix light is based on RGB colors and subtractive color mixing used to mix inks is based on CMY colors. We made two coloring methods based on the additive mixing and subtractive mixing. We performed numerical simulations of the coloring methods, and confirmed their effectiveness. We also fabricated two types of volumetric display and applied the proposed algorithm to them. One is a cubic displays constructed by light-emitting diodes (LEDs) in 8×8×8 array. Lighting patterns of LEDs are controlled by a microcomputer board. The other one is made of 7×7 array of threads. Each thread is illuminated by a projector connected with PC. As a result of the implementation, we succeeded in recording multiple 2-D color motion pictures in the volumetric displays. Our algorithm can be applied to digital signage, media art and so forth.

  4. 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.

  5. Myocardial kinematics based on tagged MRI from volumetric NURBS models

    Science.gov (United States)

    Tustison, Nicholas J.; Amini, Amir A.

    2004-04-01

    We present current research in which left ventricular deformation is estimated from tagged cardiac magnetic resonance imaging using volumetric deformable models constructed from nonuniform rational B-splines (NURBS). From a set of short and long axis images at end-diastole, the initial NURBS model is constructed by fitting two surfaces with the same parameterization to the set of epicardial and endocardial contours from which a volumetric model is created. Using normal displacements of the three sets of orthogonal tag planes as well as displacements of both tag line and contour/tag line intersection points, one can solve for the optimal homogeneous coordinates, in a least squares sense, of the control points of the NURBS model at a later time point using quadratic programming. After fitting to all time points of data, lofting the NURBS model at each time point creates a comprehensive 4-D NURBS model. From this model, we can extract 3-D myocardial displacement fields and corresponding strain maps, which are local measures of non-rigid deformation.

  6. Volumetric breast density affects performance of digital screening mammography.

    Science.gov (United States)

    Wanders, Johanna O P; Holland, Katharina; Veldhuis, Wouter B; Mann, Ritse M; Pijnappel, Ruud M; Peeters, Petra H M; van Gils, Carla H; Karssemeijer, Nico

    2017-02-01

    To determine to what extent automatically measured volumetric mammographic density influences screening performance when using digital mammography (DM). 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 American College of Radiology (ACR) breast density categories. Of all the examinations, 21.6% were categorized as density category 1 ('almost entirely fatty') and 41.5, 28.9, and 8.0% as category 2-4 ('extremely dense'), respectively. We identified 667 screen-detected and 234 interval cancers. Interval cancer rates were 0.7, 1.9, 2.9, and 4.4‰ and false positive rates were 11.2, 15.1, 18.2, and 23.8‰ for categories 1-4, respectively (both p-trend density categories: 85.7, 77.6, 69.5, and 61.0% for categories 1-4, respectively (p-trend density, automatically measured on digital mammograms, impacts screening performance measures along the same patterns as established with ACR breast density categories. Since measuring breast density fully automatically has much higher reproducibility than visual assessment, this automatic method could help with implementing density-based supplemental screening.

  7. Volumetric properties of human islet amyloid polypeptide in liquid water.

    Science.gov (United States)

    Brovchenko, I; Andrews, M N; Oleinikova, A

    2010-04-28

    The volumetric properties of human islet amyloid polypeptide (hIAPP) in water were studied in a wide temperature range by computer simulations. The intrinsic density rho(p) and the intrinsic thermal expansion coefficient alpha(p) of hIAPP were evaluated by taking into account the difference between the volumetric properties of hydration and bulk water. The density of hydration water rho(h) was found to decrease almost linearly with temperature upon heating and its thermal expansion coefficient was found to be notably higher than that of bulk water. The peptide surface exposed to water is more hydrophobic and its rho(h) is smaller in conformation with a larger number of intrapeptide hydrogen bonds. The two hIAPP peptides studied (with and without disulfide bridge) show negative alpha(p), which is close to zero at 250 K and decreases to approximately -1.5 x 10(-3) K(-1) upon heating to 450 K. The analysis of various structural properties of peptides shows a correlation between the intrinsic peptide volumes and the number of intrapeptide hydrogen bonds. The obtained negative values of alpha(p) can be attributed to the shrinkage of the inner voids of the peptides upon heating.

  8. Volumetric verification of multiaxis machine tool using laser tracker.

    Science.gov (United States)

    Aguado, Sergio; Samper, David; Santolaria, Jorge; Aguilar, Juan José

    2014-01-01

    This paper aims to present a method of volumetric verification in machine tools with linear and rotary axes using a laser tracker. Beyond a method for a particular machine, it presents a methodology that can be used in any machine type. Along this paper, the schema and kinematic model of a machine with three axes of movement, two linear and one rotational axes, including the measurement system and the nominal rotation matrix of the rotational axis are presented. Using this, the machine tool volumetric error is obtained and nonlinear optimization techniques are employed to improve the accuracy of the machine tool. The verification provides a mathematical, not physical, compensation, in less time than other methods of verification by means of the indirect measurement of geometric errors of the machine from the linear and rotary axes. This paper presents an extensive study about the appropriateness and drawbacks of the regression function employed depending on the types of movement of the axes of any machine. In the same way, strengths and weaknesses of measurement methods and optimization techniques depending on the space available to place the measurement system are presented. These studies provide the most appropriate strategies to verify each machine tool taking into consideration its configuration and its available work space.

  9. The Volumetric Rate of Superluminous Supernovae at z~1

    CERN Document Server

    Prajs, S; Smith, M; Levan, A; Karpenka, N V; Edwards, T D P; Walker, C R; Wolf, W M; Balland, C; Carlberg, R; Howell, A; Lidman, C; Pain, R; Pritchet, C; Ruhlmann-Kleider, V

    2016-01-01

    We present a measurement of the volumetric rate of superluminous supernovae (SLSNe) at z~1, measured using archival data from the first four years of the Canada-France-Hawaii Telescope Supernova Legacy Survey (SNLS). We develop a method for the photometric classification of SLSNe to construct our sample. Our sample includes two previously spectroscopically-identified objects, and a further new candidate selected using our classification technique. We use the point-source recovery efficiencies from Perrett et.al. (2010) and a Monte Carlo approach to calculate the rate based on our SLSN sample. We find that the three identified SLSNe from SNLS give a rate of 91 (+76/-36) SNe/Yr/Gpc^3 at a volume-weighted redshift of z=1.13. This is equivalent to 2.2 (+1.8/-0.9) x10^-4 of the volumetric core collapse supernova rate at the same redshift. When combined with other rate measurements from the literature, we show that the rate of SLSNe increases with redshift in a manner consistent with that of the cosmic star formati...

  10. Volumetric modulated arc therapy for carotid sparing in the management of early glottic cancer

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Young Suk; Lee, Sol Min; Kim, Gwi Eon [Dept. of Radiation Oncology, Jeju National University Hospital, Jeju National University School of Medicine, Jeju (Korea, Republic of); Lee, Jae Gi; Park, Jong In; Sung, Won Mo [Program in Biomedical Radiation Sciences, Dept. of Transdisciplinary Studies, Graduate School of Convergence Science and Technology, Seoul National University, Seoul (Korea, Republic of)

    2016-03-15

    Radiotherapy of the neck is known to cause carotid artery stenosis. We compared the carotid artery dose received between volumetric modulated arc therapy (VMAT) and conventional fixed-field intensity-modulated radiotherapy (IMRT) plans in patients with early glottic cancer. Twenty-one early glottic cancer patients who previously underwent definitive radiotherapy were selected for this study. For each patient, double arc VMAT, 8-field IMRT, 3-dimensional conformal radiotherapy (3DCRT), and lateral parallel-opposed photon field radiotherapy (LPRT) plans were created. The 3DCRT plan was generated using lateral parallel-opposed photon fields plus an anterior photon field. VMAT and IMRT treatment plan optimization was performed under standardized conditions to obtain adequate target volume coverage and spare the carotid artery. Dose-volume specifications for the VMAT, IMRT, 3DCRT, and LPRT plans were calculated with radiotherapy planning system. Monitor units (MUs) and delivery time were measured to evaluate treatment efficiency. Target volume coverage and homogeneity results were comparable between VMAT and IMRT; however, VMAT was superior to IMRT for carotid artery dose sparing. The mean dose to the carotid arteries in double arc VMAT was reduced by 6.8% compared to fixed-field IMRT (p < 0.001). The MUs for VMAT and IMRT were not significantly different (p = 0.089). VMAT allowed an approximately two-fold reduction in treatment delivery time in comparison to IMRT (3 to 5 minutes vs. 5 to 10 minutes). VMAT resulted in a lower carotid artery dose compared to conventional fixed-field IMRT, and maintained good target coverage in patients with early glottic cancer.

  11. Volumetric Modulated Arc Therapy vs. IMRT for the Treatment of Distal Esophageal Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Van Benthuysen, Liam, E-mail: liam.vanbenthuysen@roswellpark.org; Hales, Lee; Podgorsak, Matthew B.

    2011-01-01

    Several studies have demonstrated that volumetric modulated arc therapy (VMAT) has the ability to reduce monitor units and treatment time when compared with intensity-modulated radiation therapy (IMRT). This study aims to demonstrate that VMAT is able to provide adequate organs at risk (OAR) sparing and planning target volume (PTV) coverage for adenocarcinoma of the distal esophagus while reducing monitor units and treatment time. Fourteen patients having been treated previously for esophageal cancer were planned using both VMAT and IMRT techniques. Dosimetric quality was evaluated based on doses to several OARs, as well as coverage of the PTV. Treatment times were assessed by recording the number of monitor units required for dose delivery. Body V{sub 5} was also recorded to evaluate the increased volume of healthy tissue irradiated to low doses. Dosimetric differences in OAR sparing between VMAT and IMRT were comparable. PTV coverage was similar for the 2 techniques but it was found that IMRT was capable of delivering a slightly more homogenous dose distribution. Of the 14 patients, 12 were treated with a single arc and 2 were treated with a double arc. Single-arc plans reduced monitor units by 42% when compared with the IMRT plans. Double-arc plans reduced monitor units by 67% when compared with IMRT. The V{sub 5} for the body was found to be 18% greater for VMAT than for IMRT. VMAT has the capability to decrease treatment times over IMRT while still providing similar OAR sparing and PTV coverage. Although there will be a smaller risk of patient movement during VMAT treatments, this advantage comes at the cost of delivering small doses to a greater volume of the patient.

  12. Volumetric modulated arc therapy vs. IMRT for the treatment of distal esophageal cancer.

    Science.gov (United States)

    Van Benthuysen, Liam; Hales, Lee; Podgorsak, Matthew B

    2011-01-01

    Several studies have demonstrated that volumetric modulated arc therapy (VMAT) has the ability to reduce monitor units and treatment time when compared with intensity-modulated radiation therapy (IMRT). This study aims to demonstrate that VMAT is able to provide adequate organs at risk (OAR) sparing and planning target volume (PTV) coverage for adenocarcinoma of the distal esophagus while reducing monitor units and treatment time. Fourteen patients having been treated previously for esophageal cancer were planned using both VMAT and IMRT techniques. Dosimetric quality was evaluated based on doses to several OARs, as well as coverage of the PTV. Treatment times were assessed by recording the number of monitor units required for dose delivery. Body V(5) was also recorded to evaluate the increased volume of healthy tissue irradiated to low doses. Dosimetric differences in OAR sparing between VMAT and IMRT were comparable. PTV coverage was similar for the 2 techniques but it was found that IMRT was capable of delivering a slightly more homogenous dose distribution. Of the 14 patients, 12 were treated with a single arc and 2 were treated with a double arc. Single-arc plans reduced monitor units by 42% when compared with the IMRT plans. Double-arc plans reduced monitor units by 67% when compared with IMRT. The V(5) for the body was found to be 18% greater for VMAT than for IMRT. VMAT has the capability to decrease treatment times over IMRT while still providing similar OAR sparing and PTV coverage. Although there will be a smaller risk of patient movement during VMAT treatments, this advantage comes at the cost of delivering small doses to a greater volume of the patient.

  13. Precipitation in the Solar System

    Science.gov (United States)

    McIntosh, Gordon

    2007-01-01

    As an astronomy instructor, I am always looking for commonly observed Earthly experiences to help my students and me understand and appreciate similar occurrences elsewhere in the solar system. Recently I wrote a short TPT article on frost. This paper is on the related phenomena of precipitation. Precipitation, so common on most of the Earth's…

  14. Precipitation in the Solar System

    Science.gov (United States)

    McIntosh, Gordon

    2007-01-01

    As an astronomy instructor, I am always looking for commonly observed Earthly experiences to help my students and me understand and appreciate similar occurrences elsewhere in the solar system. Recently I wrote a short TPT article on frost. This paper is on the related phenomena of precipitation. Precipitation, so common on most of the Earth's…

  15. Modeling solid-state precipitation

    CERN Document Server

    Nebylov, AlexanderKozeschnik, Ernst

    2012-01-01

    Over recent decades, modeling and simulation of solid-state precipitation has attracted increased attention in academia and industry due to their important contributions in designing properties of advanced structural materials and in increasing productivity and decreasing costs for expensive alloying. In particular, precipitation of second phases is an important means for controlling the mechanical-technological properties of structural materials. However, profound physical modeling of precipitation is not a trivial task. This book introduces you to the classical methods of precipitation modeling and to recently-developed advanced, computationally-efficient techniques. If you're a research professional, academic, or student, you'll learn: nucleation theory, precipitate growth, calculation of interfacial energies. advanced techniques for technologically relevant multicomponent systems and complex thermo-mechanical treatments. numerical approaches using evolution equations and discrete particle size distribu...

  16. Encoding information into precipitation structures

    Science.gov (United States)

    Martens, Kirsten; Bena, Ioana; Droz, Michel; Rácz, Zoltan

    2008-12-01

    Material design at submicron scales would be profoundly affected if the formation of precipitation patterns could be easily controlled. It would allow the direct building of bulk structures, in contrast to traditional techniques which consist of removing material in order to create patterns. Here, we discuss an extension of our recent proposal of using electrical currents to control precipitation bands which emerge in the wake of reaction fronts in A+ + B- → C reaction-diffusion processes. Our main result, based on simulating the reaction-diffusion-precipitation equations, is that the dynamics of the charged agents can be guided by an appropriately designed time-dependent electric current so that, in addition to the control of the band spacing, the width of the precipitation bands can also be tuned. This makes straightforward the encoding of information into precipitation patterns and, as an amusing example, we demonstrate the feasibility by showing how to encode a musical rhythm.

  17. Evaluation of Model Microphysics Within Precipitation Bands of Extratropical Cyclones

    Science.gov (United States)

    Colle, Brian A.; Yu, Ruyi; Molthan, Andrew L.; Nesbitt, Steven

    2014-01-01

    It is hypothesized microphysical predictions have greater uncertainties/errors when there are complex interactions that result from mixed phased processes like riming. Use Global Precipitation Measurement (GPM) Mission ground validation studies in Ontario, Canada to verify and improve parameterizations. The WRF realistically simulated the warm frontal snowband at relatively short lead times (1014 h). The snowband structire is sensitive to the microphysical parameterization used in WRF. The Goddard and SBUYLin most realistically predicted the band structure, but overpredicted snow content. The double moment Morrison scheme best produced the slope of the snow distribution, but it underpredicted the intercept. All schemes and the radar derived (which used dry snow ZR) underpredicted the surface precipitation amount, likely because there was more cloud water than expected. The Morrison had the most cloud water and the best precipitation prediction of all schemes.

  18. Influence of Reaction Time of Urea Hydrolysis-Based Co-precipitation on the Structure of ZnA! Layered Double Hydroxides and the Phosphate Adsorption%尿素分解共沉淀法中反应时间对ZnAl类水滑石结构和磷吸附性能的影响

    Institute of Scientific and Technical Information of China (English)

    陆英; 程翔; 邢波; 孙中恩; 孙德智

    2012-01-01

    A series of ZnAl layered double hydroxides(LDHs) were prepared by urea hydrolysis-based homogeneous co-precipitation for studying their structure and phosphate adsorption capacities.The results show that all the samples exhibited a typical layered structure as the reaction time extended from 12 h to 96 h,whereas Zn/Al molar ratio in the ZnAls decreased from 2.06 to 0.70 and the specific surface area markedly increased to be 7.6-fold higher than that of ZnAl-12.Phosphate adsorption capacity of the ZnAl was in general increased gradually with the reaction time extension,which can be attributed to the surface area rising as well as the increased positive charge of LDHs layer caused by a higher proportion of Al.This reveals that physicochemical adsorption on LDHs surface would have played an important role during the phosphate adsorption.With a reaction time of 24 h,a high amount of exchangeable interlayer anions was observed,giving rise to a highest phosphate uptake of 34.1 mg·g-1 by the ZnAl-24.It indicates the ion exchange was another major pathway for the phosphate removal.For all the ZnAls with different reaction times,the phosphate adsorption isotherms fit well with Langmuir-type equations;the adsorption kinetics followed pseudo-second-order models.%采用尿素分解均匀共沉淀法合成了一系列反应时间不同的ZnAl类水滑石,考察了其结构特征及其对水中磷酸根的吸附性能.结果表明,随着反应时间由12 h增加至96 h,制得的ZnAl均具有典型的类水滑石层状结构,但其中的n(Zn)/n(Al)由2.06降至0.70,比表面积升至ZnAl-12的7.6倍.样品中Al比例升高引起的层板正电性增加以及样品比表面积的升高引起了ZnAl对水中磷酸根的吸附性能总体上随着其制备反应时间的增加逐渐增强,同时表明表面的物理化学吸附在磷酸根的去除过程中具有重要作用.当反应时间为24 h时,制备得到的ZnAl类水滑石由于其很高的可交换阴离子

  19. Double Conditional Expectation

    Institute of Scientific and Technical Information of China (English)

    HU Di-he

    2004-01-01

    The concept of double conditional expectation is introduced. A series of properties for the double conditional expectation are obtained several convergence theorems and Jensen inequality are proved. Finally we discuss the special cases and application for double conditional expectation.

  20. Rapid mapping of volumetric machine errors using distance measurements

    Energy Technology Data Exchange (ETDEWEB)

    Krulewich, D.A.

    1998-04-01

    This paper describes a relatively inexpensive, fast, and easy to execute approach to maping the volumetric errors of a machine tool, coordinate measuring machine, or robot. An error map is used to characterize a machine or to improve its accuracy by compensating for the systematic errors. The method consists of three steps: (1) models the relationship between volumetric error and the current state of the machine, (2) acquiring error data based on distance measurements throughout the work volume; and (3)fitting the error model using the nonlinear equation for the distance. The error model is formulated from the kinematic relationship among the six degrees of freedom of error an each moving axis. Expressing each parametric error as function of position each is combined to predict the error between the functional point and workpiece, also as a function of position. A series of distances between several fixed base locations and various functional points in the work volume is measured using a Laser Ball Bar (LBB). Each measured distance is a non-linear function dependent on the commanded location of the machine, the machine error, and the location of the base locations. Using the error model, the non-linear equation is solved producing a fit for the error model Also note that, given approximate distances between each pair of base locations, the exact base locations in the machine coordinate system determined during the non-linear filling procedure. Furthermore, with the use of 2048 more than three base locations, bias error in the measuring instrument can be removed The volumetric errors of three-axis commercial machining center have been mapped using this procedure. In this study, only errors associated with the nominal position of the machine were considered Other errors such as thermally induced and load induced errors were not considered although the mathematical model has the ability to account for these errors. Due to the proprietary nature of the projects we are

  1. Volumetric Modulated Arc Radiotherapy for Early Stage Non-Small-Cell Lung Carcinoma: Is It Better Than the Conventional Static Beam Intensity Modulated Radiotherapy?

    Directory of Open Access Journals (Sweden)

    Vincent Wing Cheung Wu

    2014-01-01

    Full Text Available This study compared the performance of volumetric modulated arc therapy (VMAT techniques: single arc volumetric modulated arc therapy (SA-VMAT and double arc volumetric modulated arc therapy (DA-VMAT with the static beam conventional intensity modulated radiotherapy (C-IMRT for non-small-cell lung carcinoma (NSCLC. Twelve stage I and II NSCLC patients were recruited and their planning CT with contoured planning target volume (PTV and organs at risk (OARs was used for planning. Using the same dose constraints and planning objectives, the C-IMRT, SA-VMAT, and DA-VMAT plans were optimized. C-IMRT consisted of 7 static beams, while SA-VMAT and DA-VMAT plans consisted of one and two full gantry rotations, respectively. No significant difference was found among the three techniques in target homogeneity and conformity. Mean lung dose in C-IMRT plan was significantly lower than that in DA-VMAT plan P=0.04. The ability of OAR sparing was similar among the three techniques, with no significant difference in V20, V10, or V5 of normal lungs, spinal cord, and heart. Less MUs were required in SA-VMAT and DA-VMAT. Besides, SA-VMAT required the shortest beam on time among the three techniques. In treatment of early stage NSCLC, no significant dosimetric superiority was shown by the VMAT techniques over C-IMRT and DA-VMAT over SA-VMAT.

  2. An investigation of the dose distribution effect related with collimator angle in volumetric arc therapy of prostate cancer

    Directory of Open Access Journals (Sweden)

    Bora Tas

    2016-01-01

    Full Text Available To investigate the dose-volume variations of planning target volume (PTV and organ at risks (OARs in eleven prostate cancer patients planned with single and double arc volumetric modulated arc therapy (VMAT when varying collimator angle. Single and double arc VMAT treatment plans were created using Monaco5.0® with collimator angle set to 0°. All plans were normalized 7600 cGy dose to the 95% of clinical target volume (CTV volume. The single arc VMAT plans were reoptimized with different collimator angles (0°, 15°, 30°, 45°, 60°, 75°, and 90°, and for double arc VMAT plans (0–0°, 15°–345, 30–330°, 45–315°, 60–300°, 75–285°, 90–270° using the same optimization parameters. For the comparison the parameters of heterogeneity index (HI, dose-volume histogram and minimum dose to the 95% of PTV volume (D95 PTV calculated and analyzed. The best plans were verified using 2 dimensional ion chamber array IBA Matrixx® and three-dimensional IBA Compass® program. The comparison between calculation and measurement were made by the γ-index (3%/3 mm analysis. A higher D95 (PTV were found for single arc VMAT with 15° collimator angle. For double arc, VMAT with 60–300° and 75–285° collimator angles. However, lower rectum doses obtained for 75–285° collimator angles. There was no significant dose difference, based on other OARs which are bladder and femur head. When we compared single and double arc VMAT's D95 (PTV, we determined 2.44% high coverage and lower HI with double arc VMAT. All plans passed the γ-index (3%/3 mm analysis with more than 97% of the points and we had an average γ-index for CTV 0.36, for PTV 0.32 with double arc VMAT. These results were significant by Wilcoxon signed rank test statistically. The results show that dose coverage of target and OAR's doses also depend significantly on the collimator angles due to the geometry of target and OARs. Based on the results we have decided to plan prostate

  3. 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.

  4. 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.

  5. Volumetric properties of water/AOT/isooctane microemulsions.

    Science.gov (United States)

    Du, Changfei; He, Wei; Yin, Tianxiang; Shen, Weiguo

    2014-12-23

    The densities of AOT/isooctane micelles and water/AOT/isooctane microemulsions with the molar ratios R of water to AOT being 2, 8, 10, 12, 16, 18, 20, 25, 30, and 40 were measured at 303.15 K. The apparent specific volumes of AOT and the quasi-component water/AOT at various concentrations were calculated and used to estimate the volumetric properties of AOT and water in the droplets and in the continuous oil phase, to discuss the interaction between the droplets, and to determine the critical micelle concentration and the critical microemulsion concentrations. A thermodynamic model was proposed to analysis the stability boundary of the microemulsion droplets, which confirms the maximum value of R being about 65 for the stable AOT/water/isooctane microemulsion droplets.

  6. 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.

  7. In-line hologram segmentation for volumetric samples.

    Science.gov (United States)

    Orzó, László; Göröcs, Zoltán; Fehér, András; Tőkés, Szabolcs

    2013-01-01

    We propose a fast, noniterative method to segment an in-line hologram of a volumetric sample into in-line subholograms according to its constituent objects. In contrast to the phase retrieval or twin image elimination algorithms, we do not aim or require to reconstruct the complex wave field of all the objects, which would be a more complex task, but only provide a good estimate about the contribution of the particular objects to the original hologram quickly. The introduced hologram segmentation algorithm exploits the special inner structure of the in-line holograms and applies only the estimated supports and reconstruction distances of the corresponding objects as parameters. The performance of the proposed method is demonstrated and analyzed experimentally both on synthetic and measured holograms. We discussed how the proposed algorithm can be efficiently applied for object reconstruction and phase retrieval tasks.

  8. Three-Dimensional Volumetric Restoration by Structural Fat Grafting

    Science.gov (United States)

    Clauser, Luigi C.; Consorti, Giuseppe; Elia, Giovanni; Galié, Manlio; Tieghi, Riccardo

    2013-01-01

    The use of adipose tissue transfer for correction of maxillofacial defects was reported for the first time at the end of the 19th century. Structural fat grafting (SFG) was introduced as a way to improve facial esthetics and in recent years has evolved into applications in craniomaxillofacial reconstructive surgery. Several techniques have been proposed for harvesting and grafting the fat. However, owing to the damage of many adipocytes during these maneuvers, the results have not been satisfactory and have required several fat injection procedures for small corrections. The author's (L.C.) overview the application of SFG in the management of volumetric deficit in the craniomaxillofacial in patients treated with a long-term follow-up. PMID:24624259

  9. Semi-automatic volumetrics system to parcellate ROI on neocortex

    Science.gov (United States)

    Tan, Ou; Ichimiya, Tetsuya; Yasuno, Fumihiko; Suhara, Tetsuya

    2002-05-01

    A template-based and semi-automatic volumetrics system--BrainVol is build to divide the any given patient brain to neo-cortical and sub-cortical regions. The standard region is given as standard ROI drawn on a standard brain volume. After normalization between the standard MR image and the patient MR image, the sub-cortical ROIs' boundary are refined based on gray matter. The neo-cortical ROIs are refined by sulcus information that is semi-automatically marked on the patient brain. Then the segmentation is applied to 4D PET image of same patient for calculation of TAC (Time Activity Curve) by co-registration between MR and PET.

  10. Out-of-core clustering of volumetric datasets

    Institute of Scientific and Technical Information of China (English)

    GRANBERG Carl J.; LI Ling

    2006-01-01

    In this paper we present a novel method for dividing and clustering large volumetric scalar out-of-core datasets. This work is based on the Ordered Cluster Binary Tree (OCBT) structure created using a top-down or divisive clustering method. The OCBT structure allows fast and efficient sub volume queries to be made in combination with level of detail (LOD) queries of the tree. The initial partitioning of the large out-of-core dataset is done by using non-axis aligned planes calculated using Principal Component Analysis (PCA). A hybrid OCBT structure is also proposed where an in-core cluster binary tree is combined with a large out-of-core file.

  11. Volumetric Survey Speed: A Figure of Merit for Transient Surveys

    CERN Document Server

    Bellm, Eric C

    2016-01-01

    Time-domain surveys can exchange sky coverage for revisit frequency, complicating the comparison of their relative capabilities. By using different revisit intervals, a specific camera may execute surveys optimized for discovery of different classes of transient objects. We propose a new figure of merit, the instantaneous volumetric survey speed, for evaluating transient surveys. This metric defines the trade between cadence interval and snapshot survey volume and so provides a natural means of comparing survey capability. The related metric of areal survey speed imposes a constraint on the range of possible revisit times: we show that many modern time-domain surveys are limited by the amount of fresh sky available each night. We introduce the concept of "spectroscopic accessibility" and discuss its importance for transient science goals requiring followup observing. We present an extension of the control time algorithm for cases where multiple consecutive detections are required. Finally, we explore how surv...

  12. Volumetric optical coherence microscopy enabled by aberrated optics (Conference Presentation)

    Science.gov (United States)

    Mulligan, Jeffrey A.; Liu, Siyang; Adie, Steven G.

    2017-02-01

    Optical coherence microscopy (OCM) is an interferometric imaging technique that enables high resolution, non-invasive imaging of 3D cell cultures and biological tissues. Volumetric imaging with OCM suffers a trade-off between high transverse resolution and poor depth-of-field resulting from defocus, optical aberrations, and reduced signal collection away from the focal plane. While defocus and aberrations can be compensated with computational methods such as interferometric synthetic aperture microscopy (ISAM) or computational adaptive optics (CAO), reduced signal collection must be physically addressed through optical hardware. Axial scanning of the focus is one approach, but comes at the cost of longer acquisition times, larger datasets, and greater image reconstruction times. Given the capabilities of CAO to compensate for general phase aberrations, we present an alternative method to address the signal collection problem without axial scanning by using intentionally aberrated optical hardware. We demonstrate the use of an astigmatic spectral domain (SD-)OCM imaging system to enable single-acquisition volumetric OCM in 3D cell culture over an extended depth range, compared to a non-aberrated SD-OCM system. The transverse resolution of the non-aberrated and astigmatic imaging systems after application of CAO were 2 um and 2.2 um, respectively. The depth-range of effective signal collection about the nominal focal plane was increased from 100 um in the non-aberrated system to over 300 um in the astigmatic system, extending the range over which useful data may be acquired in a single OCM dataset. We anticipate that this method will enable high-throughput cellular-resolution imaging of dynamic biological systems over extended volumes.

  13. Marginal Space Deep Learning: Efficient Architecture for Volumetric Image Parsing.

    Science.gov (United States)

    Ghesu, Florin C; Krubasik, Edward; Georgescu, Bogdan; Singh, Vivek; Yefeng Zheng; Hornegger, Joachim; Comaniciu, Dorin

    2016-05-01

    Robust and fast solutions for anatomical object detection and segmentation support the entire clinical workflow from diagnosis, patient stratification, therapy planning, intervention and follow-up. Current state-of-the-art techniques for parsing volumetric medical image data are typically based on machine learning methods that exploit large annotated image databases. Two main challenges need to be addressed, these are the efficiency in scanning high-dimensional parametric spaces and the need for representative image features which require significant efforts of manual engineering. We propose a pipeline for object detection and segmentation in the context of volumetric image parsing, solving a two-step learning problem: anatomical pose estimation and boundary delineation. For this task we introduce Marginal Space Deep Learning (MSDL), a novel framework exploiting both the strengths of efficient object parametrization in hierarchical marginal spaces and the automated feature design of Deep Learning (DL) network architectures. In the 3D context, the application of deep learning systems is limited by the very high complexity of the parametrization. More specifically 9 parameters are necessary to describe a restricted affine transformation in 3D, resulting in a prohibitive amount of billions of scanning hypotheses. The mechanism of marginal space learning provides excellent run-time performance by learning classifiers in clustered, high-probability regions in spaces of gradually increasing dimensionality. To further increase computational efficiency and robustness, in our system we learn sparse adaptive data sampling patterns that automatically capture the structure of the input. Given the object localization, we propose a DL-based active shape model to estimate the non-rigid object boundary. Experimental results are presented on the aortic valve in ultrasound using an extensive dataset of 2891 volumes from 869 patients, showing significant improvements of up to 45

  14. The volumetric rate of superluminous supernovae at z ˜ 1

    Science.gov (United States)

    Prajs, S.; Sullivan, M.; Smith, M.; Levan, A.; Karpenka, N. V.; Edwards, T. D. P.; Walker, C. R.; Wolf, W. M.; Balland, C.; Carlberg, R.; Howell, D. A.; Lidman, C.; Pain, R.; Pritchet, C.; Ruhlmann-Kleider, V.

    2017-01-01

    We present a measurement of the volumetric rate of superluminous supernovae (SLSNe) at z ˜ 1.0, measured using archival data from the first four years of the Canada-France-Hawaii Telescope Supernova Legacy Survey (SNLS). We develop a method for the photometric classification of SLSNe to construct our sample. Our sample includes two previously spectroscopically identified objects, and a further new candidate selected using our classification technique. We use the point-source recovery efficiencies from Perrett et al. and a Monte Carlo approach to calculate the rate based on our SLSN sample. We find that the three identified SLSNe from SNLS give a rate of 91^{+76}_{-36} SNe yr-1 Gpc-3 at a volume-weighted redshift of z = 1.13. This is equivalent to 2.2^{+1.8}_{-0.9}× 10^{-4} of the volumetric core-collapse supernova rate at the same redshift. When combined with other rate measurements from the literature, we show that the rate of SLSNe increases with redshift in a manner consistent with that of the cosmic star formation history. We also estimate the rate of ultra-long gamma-ray bursts based on the events discovered by the Swift satellite, and show that it is comparable to the rate of SLSNe, providing further evidence of a possible connection between these two classes of events. We also examine the host galaxies of the SLSNe discovered in SNLS, and find them to be consistent with the stellar-mass distribution of other published samples of SLSNe.

  15. Volumetric analysis of corticocancellous bones using CT data

    Energy Technology Data Exchange (ETDEWEB)

    Krappinger, Dietmar; Linde, Astrid von; Rosenberger, Ralf; Blauth, Michael [Medical University Innsbruck, Department of Trauma Surgery and Sports Medicine, Innsbruck (Austria); Glodny, Bernhard; Niederwanger, Christian [Medical University Innsbruck, Department of Radiology I, Innsbruck (Austria)

    2012-05-15

    To present a method for an automated volumetric analysis of corticocancellous bones such as the superior pubic ramus using CT data and to assess the reliability of this method. Computed tomography scans of a consecutive series of 250 patients were analyzed. A Hounsfield unit (HU) thresholding-based reconstruction technique (''Vessel Tracking,'' GE Healthcare) was used. A contiguous space of cancellous bone with similar HU values between the starting and end points was automatically identified as the region of interest. The identification was based upon the density gradient to the adjacent cortical bone. The starting point was defined as the middle of the parasymphyseal corticocancellous transition zone on the axial slice showing the parasymphyseal superior pubic ramus in its maximum anteroposterior width. The end point was defined as the middle of the periarticular corticocancellous transition zone on the axial slice showing the quadrilateral plate as a thin cortical plate. The following parameters were automatically obtained on both sides: length of the center line, volume of the superior pubic ramus between the starting point and end point, minimum, maximum and mean diameter perpendicular to the center line, and mean cross-sectional area perpendicular to the center line. An automated analysis without manual adjustments was successful in 207 patients (82.8%). The center line showed a significantly greater length in female patients (67.6 mm vs 65.0 mm). The volume was greater in male patients (21.8 cm{sup 3} vs 19.4 cm{sup 3}). The intersite reliability was high with a mean difference between the left and right sides of between 0.1% (cross-sectional area) and 2.3% (volume). The method presented allows for an automated volumetric analysis of a corticocancellous bone using CT data. The method is intended to provide preoperative information for the use of intramedullary devices in fracture fixation and percutaneous cement augmentation techniques

  16. An Analysis Methodology for Stochastic Characteristic of Volumetric Error in Multiaxis CNC Machine Tool

    Directory of Open Access Journals (Sweden)

    Qiang Cheng

    2013-01-01

    Full Text Available Traditional approaches about error modeling and analysis of machine tool few consider the probability characteristics of the geometric error and volumetric error systematically. However, the individual geometric error measured at different points is variational and stochastic, and therefore the resultant volumetric error is aslo stochastic and uncertain. In order to address the stochastic characteristic of the volumetric error for multiaxis machine tool, a new probability analysis mathematical model of volumetric error is proposed in this paper. According to multibody system theory, a mean value analysis model for volumetric error is established with consideration of geometric errors. The probability characteristics of geometric errors are obtained by statistical analysis to the measured sample data. Based on probability statistics and stochastic process theory, the variance analysis model of volumetric error is established in matrix, which can avoid the complex mathematics operations during the direct differential. A four-axis horizontal machining center is selected as an illustration example. The analysis results can reveal the stochastic characteristic of volumetric error and are also helpful to make full use of the best workspace to reduce the random uncertainty of the volumetric error and improve the machining accuracy.

  17. Volumetric and two-dimensional image interpretation show different cognitive processes in learners

    NARCIS (Netherlands)

    van der Gijp, Anouk; Ravesloot, C.J.; van der Schaaf, Marieke F; van der Schaaf, Irene C; Huige, Josephine C B M; Vincken, Koen L; Ten Cate, Olle Th J; van Schaik, JPJ

    2015-01-01

    RATIONALE AND OBJECTIVES: In current practice, radiologists interpret digital images, including a substantial amount of volumetric images. We hypothesized that interpretation of a stack of a volumetric data set demands different skills than interpretation of two-dimensional (2D) cross-sectional imag

  18. High Volumetric Energy Density Hybrid Supercapacitors Based on Reduced Graphene Oxide Scrolls.

    Science.gov (United States)

    Rani, Janardhanan R; Thangavel, Ranjith; Oh, Se-I; Woo, Jeong Min; Chandra Das, Nayan; Kim, So-Yeon; Lee, Yun-Sung; Jang, Jae-Hyung

    2017-07-12

    The low volumetric energy density of reduced graphene oxide (rGO)-based electrodes limits its application in commercial electrochemical energy storage devices that require high-performance energy storage capacities in small volumes. The volumetric energy density of rGO-based electrode materials is very low due to their low packing density. A supercapacitor with enhanced packing density and high volumetric energy density is fabricated using doped rGO scrolls (GFNSs) as the electrode material. The restacking of rGO sheets is successfully controlled through synthesizing the doped scroll structures while increasing the packing density. The fabricated cell exhibits an ultrahigh volumetric energy density of 49.66 Wh/L with excellent cycling stability (>10 000 cycles). This unique design strategy for the electrode material has significant potential for the future supercapacitors with high volumetric energy densities.

  19. Global segmentation and curvature analysis of volumetric data sets using trivariate B-spline functions.

    Science.gov (United States)

    Soldea, Octavian; Elber, Gershon; Rivlin, Ehud

    2006-02-01

    This paper presents a method to globally segment volumetric images into regions that contain convex or concave (elliptic) iso-surfaces, planar or cylindrical (parabolic) iso-surfaces, and volumetric regions with saddle-like (hyperbolic) iso-surfaces, regardless of the value of the iso-surface level. The proposed scheme relies on a novel approach to globally compute, bound, and analyze the Gaussian and mean curvatures of an entire volumetric data set, using a trivariate B-spline volumetric representation. This scheme derives a new differential scalar field for a given volumetric scalar field, which could easily be adapted to other differential properties. Moreover, this scheme can set the basis for more precise and accurate segmentation of data sets targeting the identification of primitive parts. Since the proposed scheme employs piecewise continuous functions, it is precise and insensitive to aliasing.

  20. The duct selective volumetric receiver: potential for different selectivity strategies and stability issues

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Casals, X. [Universidad Pontificia Comillas-ICAI, Madrid (Spain). Dept. de Fluidos y Calor; Ajona, J.I. [Departamento de Energia Solar, Viessemann, Poligono Industrial San Marcos, Getafe (Spain)

    1999-07-01

    Recently much theoretical and experimental work has been conducted on volumetric receivers. However, not much attention has been paid to the possibilities of using different selectivity mechanisms to minimize radiation thermal losses, which are the main ones at high operating temperature. In this paper we present a duct volumetric receiver model and its results, which allow the evaluation of different selectivity strategies such as: conventional {epsilon}/{alpha}, geometry, frontal absorption and diffuse/specular reflection. We propose a new concept of selective volumetric receivers based on a solar-specular/infrared-diffuse radiative behaviour and evaluate its potential for efficiency improvement. In recent work on volumetric receivers based on simplified models, it has been concluded that the duct volumetric receiver is inherently unstable when working with high solar flux. We didn't find any unstable receiver behaviour even at very high solar fluxes, and conclude that a substantial potential for efficiency improvement exists if selectivity mechanisms are properly combined. (author)

  1. Enhanced volumetric visualization for real time 4D intraoperative ophthalmic swept-source OCT.

    Science.gov (United States)

    Viehland, Christian; Keller, Brenton; Carrasco-Zevallos, Oscar M; Nankivil, Derek; Shen, Liangbo; Mangalesh, Shwetha; Viet, Du Tran; Kuo, Anthony N; Toth, Cynthia A; Izatt, Joseph A

    2016-05-01

    Current-generation software for rendering volumetric OCT data sets based on ray casting results in volume visualizations with indistinct tissue features and sub-optimal depth perception. Recent developments in hand-held and microscope-integrated intrasurgical OCT designed for real-time volumetric imaging motivate development of rendering algorithms which are both visually appealing and fast enough to support real time rendering, potentially from multiple viewpoints for stereoscopic visualization. We report on an enhanced, real time, integrated volumetric rendering pipeline which incorporates high performance volumetric median and Gaussian filtering, boundary and feature enhancement, depth encoding, and lighting into a ray casting volume rendering model. We demonstrate this improved model implemented on graphics processing unit (GPU) hardware for real-time volumetric rendering of OCT data during tissue phantom and live human surgical imaging. We show that this rendering produces enhanced 3D visualizations of pathology and intraoperative maneuvers compared to standard ray casting.

  2. Development of an ELP-Z based mAb affinity precipitation process using scaled-down filtration techniques.

    Science.gov (United States)

    Sheth, Rahul D; Bhut, Bharat V; Jin, Mi; Li, Zhengjian; Chen, Wilfred; Cramer, Steven M

    2014-12-20

    In this work, a proof of concept elastin-like polypeptide-Z domain fusion (ELP-Z) based monoclonal antibody (mAb) affinity precipitation process is developed using scaled-down filtration techniques. Tangential flow filtration (TFF) is examined for the recovery of ELP-Z-mAb precipitates formed during the mAb binding step and the ELP-Z precipitates formed during the mAb elution step. TFF results in complete precipitate recovery during both stages of the process and high host cell protein and DNA impurity clearance after diafiltration. Total recycle TFF experiments are then employed to determine permeate flux as a function of the precipitate concentration for both stages of the process. While the ELP-Z-mAb precipitate recovery step resulted in high permeate flux (550-600L/m(2)/h/bar), the ELP-Z precipitates are shown to severely foul the TFF membrane, causing rapid flux decay. Confocal microscopy of the ELP-Z-mAb and ELP-Z precipitates suggests significant differences in the morphology and the kinetics of formation of these precipitates, which is likely responsible for their different behavior during TFF. Finally, an alternative normal flow filtration strategy is developed for the ELP-Z precipitate recovery step during mAb elution, using a combination of 5μm and a 0.45/0.2μm filters. Using this approach, the ELP-Z precipitates are separated from the final mAb elution pool at high volumetric throughputs and high ELP-Z recovery (96%) is obtained after resolubilization from the filter. This study demonstrates that the ELP-Z affinity precipitation process can be readily scaled up using conventional membrane processing.

  3. Atrial Ectopics Precipitating Atrial Fibrillation

    OpenAIRE

    Johnson Francis

    2015-01-01

    Holter monitor tracing showing blocked atrial ectopics and atrial ectopic precipitating atrial fibrillation is being demonstrated. Initially it was coarse atrial fibrillation, which rapidly degenerated into fine atrial fibrillation.

  4. CPC Merged Analysis of Precipitation

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The monthly data set consists of two files containing global monthly averaged precipitation rate values at a 2.5x2.5 resolution starting in 1979. Values are obtained...

  5. Hourly and Daily Precipitation Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Precipitation reports submitted on many form types, including tabular and autographic charts. Reports are almost exclusively from the US Cooperative Observer Network.

  6. Volumetric and two-dimensional image interpretation show different cognitive processes in learners.

    Science.gov (United States)

    van der Gijp, Anouk; Ravesloot, Cécile J; van der Schaaf, Marieke F; van der Schaaf, Irene C; Huige, Josephine C B M; Vincken, Koen L; Ten Cate, Olle Th J; van Schaik, Jan P J

    2015-05-01

    In current practice, radiologists interpret digital images, including a substantial amount of volumetric images. We hypothesized that interpretation of a stack of a volumetric data set demands different skills than interpretation of two-dimensional (2D) cross-sectional images. This study aimed to investigate and compare knowledge and skills used for interpretation of volumetric versus 2D images. Twenty radiology clerks were asked to think out loud while reading four or five volumetric computed tomography (CT) images in stack mode and four or five 2D CT images. Cases were presented in a digital testing program allowing stack viewing of volumetric data sets and changing views and window settings. Thoughts verbalized by the participants were registered and coded by a framework of knowledge and skills concerning three components: perception, analysis, and synthesis. The components were subdivided into 16 discrete knowledge and skill elements. A within-subject analysis was performed to compare cognitive processes during volumetric image readings versus 2D cross-sectional image readings. Most utterances contained knowledge and skills concerning perception (46%). A smaller part involved synthesis (31%) and analysis (23%). More utterances regarded perception in volumetric image interpretation than in 2D image interpretation (Median 48% vs 35%; z = -3.9; P Cognitive processes in volumetric and 2D cross-sectional image interpretation differ substantially. Volumetric image interpretation draws predominantly on perceptual processes, whereas 2D image interpretation is mainly characterized by synthesis. The results encourage the use of volumetric images for teaching and testing perceptual skills. Copyright © 2015 AUR. Published by Elsevier Inc. All rights reserved.

  7. Non-isothermal precipitation behaviors of Al-Mg-Si-Cu alloys with different Zn contents

    Energy Technology Data Exchange (ETDEWEB)

    Guo, M.X., E-mail: mingxingguo@skl.ustb.edu.cn; Zhang, Y.; Zhang, X.K.; Zhang, J.S.; Zhuang, L.Z.

    2016-07-04

    The non-isothermal precipitation behaviors of Al–Mg–Si–Cu alloys with different Zn contents were investigated by differential scanning calorimetry (DSC) analysis, hardness measurement and high resolution transmission electron microscope characterization. The results show that Zn addition has a significant effect on the GP zone dissolution and precipitation of Al-Mg-Si-Cu alloys. And their activation energies change with the changes of Zn content and aging conditions. Precipitation kinetics can be improved by adding 0.5 wt% or 3.0 wt%Zn, while be suppressed after adding 1.5 wt%Zn. The Mg-Si precipitates (GP zones and β″) are still the main precipitates in the Al-Mg-Si-Cu alloys after heated up to 250 °C, and no Mg-Zn precipitates are observed in the Zn-added alloy due to the occurrence of Mg-Zn precipitates reversion. The measured age-hardening responses of the alloys are corresponding to the predicted results by the established precipitation kinetic equations. Additionally, a double-hump phenomenon of hardness appears in the artificial aging of pre-aged alloy with 3.0 wt% Zn addition, which resulted from the formation of pre-β″ and β″ precipitates. Finally, the precipitation mechanism of Al-Mg-Si-Cu alloys with different Zn contents was proposed based on the microstructure evolution and interaction forces between Mg, Si and Zn atoms.

  8. Analysis of the operating parameters of a vortex electrostatic precipitator

    Science.gov (United States)

    Congxiang, Lu; Chengwu, Yi; Rongjie, Yi; Shiwen, Liu

    2017-02-01

    A vortex electrostatic precipitator (VEP) forms a vortex flow field within a precipitator by means of the vertical staggered layout of the double-vortex collecting plate facing the direction of the gas flow. The ion concentrations within the precipitator can be significantly increased. Correspondingly, the charging and coagulation rates of fine particles and particle migration velocity are significantly improved within the VEP. Since it can effectively collect fine particles and reduce precipitator size, VEPs represent a new type of electrostatic precipitator with great application potential. In this work the change curve of the external voltage, gas velocity, row spacing and effective collecting area influencing the precipitation efficiency were acquired through a single-factor experiment. Using an orthogonal regression design, attempts were made to analyze the major operating parameters influencing the collecting efficiency of fine particles, establish a multiple linear regression model and analyze the weights of factors and then acquire quantitative rules relating experimental indicators and factors. The regression model was optimized by MATLAB programming, and we then obtained the optimal factor combination which can enhance the efficiency of fine particle collection. The final optimized result is that: when gas velocity is 3.4 m s-1, the external voltage is 18 kV, row spacing is 100 mm and the effective collecting area is 1.13 m2, the rate of fine particle collection is 89.8867%. After determining and analyzing the state of the internal flow field within the VEP by particle image velocimetry (PIV), the results show that, for a particular gas velocity, a vortex zone and laminar zone are distinctly formed within the VEP, which increases the ion transport ratio as well as the charging, coagulation and collection rates of fine particles within the precipitator, thus making further improvements in the efficiency of fine particle collection.

  9. Analysis of the operating parameters of a vortex electrostatic precipitator

    Science.gov (United States)

    Lu, Congxiang; Yi, Chengwu; Yi, Rongjie; Liu, Shiwen

    2017-02-01

    A vortex electrostatic precipitator (VEP) forms a vortex flow field within a precipitator by means of the vertical staggered layout of the double-vortex collecting plate facing the direction of the gas flow. The ion concentrations within the precipitator can be significantly increased. Correspondingly, the charging and coagulation rates of fine particles and particle migration velocity are significantly improved within the VEP. Since it can effectively collect fine particles and reduce precipitator size, VEPs represent a new type of electrostatic precipitator with great application potential. In this work the change curve of the external voltage, gas velocity, row spacing and effective collecting area influencing the precipitation efficiency were acquired through a single-factor experiment. Using an orthogonal regression design, attempts were made to analyze the major operating parameters influencing the collecting efficiency of fine particles, establish a multiple linear regression model and analyze the weights of factors and then acquire quantitative rules relating experimental indicators and factors. The regression model was optimized by MATLAB programming, and we then obtained the optimal factor combination which can enhance the efficiency of fine particle collection. The final optimized result is that: when gas velocity is 3.4 m s-1, the external voltage is 18 kV, row spacing is 100 mm and the effective collecting area is 1.13 m2, the rate of fine particle collection is 89.8867%. After determining and analyzing the state of the internal flow field within the VEP by particle image velocimetry (PIV), the results show that, for a particular gas velocity, a vortex zone and laminar zone are distinctly formed within the VEP, which increases the ion transport ratio as well as the charging, coagulation and collection rates of fine particles within the precipitator, thus making further improvements in the efficiency of fine particle collection.

  10. Precipitation hardening in Fe--Ni base austenitic alloys

    Energy Technology Data Exchange (ETDEWEB)

    Chang, K.M.

    1979-05-01

    The precipitation of metastable Ni/sub 3/X phases in the austenitic Fe--Ni-base alloys has been investigated by using various combinations of hardening elements, including Ti, Ta, Al, and Nb. The theoretical background on the formation of transition precipitates has been summarized based on: atomic size, compressibility, and electron/atom ratio. A model is proposed from an analysis of static concentration waves ordering the fcc lattice. Ordered structure of metastable precipitates will change from the triangularly ordered ..gamma..', to the rectangularly ordered ..gamma..'', as the atomic ratio (Ti + Al)/(Ta + Nb) decreases. The concurrent precipitation of ..gamma..' and ..gamma..'' occurs at 750/sup 0/C when the ratio is between 1.5 and 1.9. Aging behavior was studied over the temperature range of 500/sup 0/C to 900/sup 0/C. Typical hardness curves show a substantial hardening effect due to precipitation. A combination of strength and fracture toughness can be developed by employing double aging techniques. The growth of these coherent intermediate precipitates follows the power law with the aging time t : t/sup 1/3/ for the spherical ..gamma..' particles; and t/sup 1/2/ for the disc-shaped ..gamma..''. The equilibrium ..beta.. phase is observed to be able to nucleate on the surface of imbedded carbides. The addition of 5 wt % Cr to the age-hardened alloys provides a non-magnetic austenite which is stable against the formation of mechanically induced martensite.Cr addition retards aging kinetics of the precipitation reactions, and suppresses intergranular embrittlement caused by the high temperature solution anneal. The aging kinetics are also found to be influenced by solution annealing treatments.

  11. On the trail of double peak hydrographs

    Science.gov (United States)

    Martínez-Carreras, Núria; Hissler, Christophe; Gourdol, Laurent; Klaus, Julian; Juilleret, Jérôme; François Iffly, Jean; McDonnell, Jeffrey J.; Pfister, Laurent

    2016-04-01

    A double peak hydrograph features two peaks as a response to a unique rainfall pulse. The first peak occurs at the same time or shortly after the precipitation has started and it corresponds to a fast catchment response to precipitation. The delayed peak normally starts during the recession of the first peak, when the precipitation has already ceased. Double peak hydrographs may occur for various reasons. They can occur (i) in large catchments when lag times in tributary responses are large, (ii) in urban catchments where the first peak is often caused by direct surface runoff on impervious land cover, and the delayed peak to slower subsurface flow, and (iii) in non-urban catchments, where the first and the delayed discharge peaks are explained by different runoff mechanisms (e.g. overland flow, subsurface flow and/or deep groundwater flow) that have different response times. Here we focus on the third case, as a formal description of the different hydrological mechanisms explaining these complex hydrological dynamics across catchments with diverse physiographic characteristics is still needed. Based on a review of studies documenting double peak events we have established a formal classification of catchments presenting double peak events based on their regolith structure (geological substratum and/or its weathered products). We describe the different hydrological mechanisms that trigger these complex hydrological dynamics across each catchment type. We then use hydrometric time series of precipitation, runoff, soil moisture and groundwater levels collected in the Weierbach (0.46 km2) headwater catchment (Luxembourg) to better understand double peak hydrograph generation. Specifically, we aim to find out (1) if the generation of a double peak hydrograph is a threshold process, (2) if the hysteretic relationships between storage and discharge are consistent during single and double peak hydrographs, and (3) if different functional landscape units (the hillslopes

  12. Evaluation of CMIP5 continental precipitation simulations relative to satellite-based gauge-adjusted observations

    Energy Technology Data Exchange (ETDEWEB)

    Mehran, Ali [Univ. of California, Irvine, CA (United States). Dept. of Civil and Environmental Engineering; AghaKouchak, Amir [Univ. of California, Irvine, CA (United States). Dept. of Civil and Environmental Engineering; Phillips, Thomas J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2014-02-25

    Numerous studies have emphasized that climate simulations are subject to various biases and uncertainties. The objective of this study is to cross-validate 34 Coupled Model Intercomparison Project Phase 5 (CMIP5) historical simulations of precipitation against the Global Precipitation Climatology Project (GPCP) data, quantifying model pattern discrepancies and biases for both entire data distributions and their upper tails. The results of the Volumetric Hit Index (VHI) analysis of the total monthly precipitation amounts show that most CMIP5 simulations are in good agreement with GPCP patterns in many areas, but that their replication of observed precipitation over arid regions and certain sub-continental regions (e.g., northern Eurasia, eastern Russia, central Australia) is problematical. Overall, the VHI of the multi-model ensemble mean and median also are superior to that of the individual CMIP5 models. However, at high quantiles of reference data (e.g., the 75th and 90th percentiles), all climate models display low skill in simulating precipitation, except over North America, the Amazon, and central Africa. Analyses of total bias (B) in CMIP5 simulations reveal that most models overestimate precipitation over regions of complex topography (e.g. western North and South America and southern Africa and Asia), while underestimating it over arid regions. Also, while most climate model simulations show low biases over Europe, inter-model variations in bias over Australia and Amazonia are considerable. The Quantile Bias (QB) analyses indicate that CMIP5 simulations are even more biased at high quantiles of precipitation. Lastly, we found that a simple mean-field bias removal improves the overall B and VHI values, but does not make a significant improvement in these model performance metrics at high quantiles of precipitation.

  13. Evaluation of CMIP5 continental precipitation simulations relative to satellite-based gauge-adjusted observations

    Science.gov (United States)

    Mehran, A.; AghaKouchak, A.; Phillips, T. J.

    2014-02-01

    The objective of this study is to cross-validate 34 Coupled Model Intercomparison Project Phase 5 (CMIP5) historical simulations of precipitation against the Global Precipitation Climatology Project (GPCP) data, quantifying model pattern discrepancies, and biases for both entire distributions and their upper tails. The results of the volumetric hit index (VHI) analysis of the total monthly precipitation amounts show that most CMIP5 simulations are in good agreement with GPCP patterns in many areas but that their replication of observed precipitation over arid regions and certain subcontinental regions (e.g., northern Eurasia, eastern Russia, and central Australia) is problematical. Overall, the VHI of the multimodel ensemble mean and median also are superior to that of the individual CMIP5 models. However, at high quantiles of reference data (75th and 90th percentiles), all climate models display low skill in simulating precipitation, except over North America, the Amazon, and Central Africa. Analyses of total bias (B) in CMIP5 simulations reveal that most models overestimate precipitation over regions of complex topography (e.g., western North and South America and southern Africa and Asia), while underestimating it over arid regions. Also, while most climate model simulations show low biases over Europe, intermodel variations in bias over Australia and Amazonia are considerable. The quantile bias analyses indicate that CMIP5 simulations are even more biased at high quantiles of precipitation. It is found that a simple mean field bias removal improves the overall B and VHI values but does not make a significant improvement at high quantiles of precipitation.

  14. Chemical Data for Precipitate Samples

    Science.gov (United States)

    Foster, Andrea L.; Koski, Randolph A.

    2008-01-01

    During studies of sulfide oxidation in coastal areas of Prince William Sound in 2005, precipitate samples were collected from onshore and intertidal locations near the Ellamar, Threeman, and Beatson mine sites (chapter A, fig. 1; table 7). The precipitates include jarosite and amorphous Fe oxyhydroxide from Ellamar, amorphous Fe oxyhydroxide from Threeman, and amorphous Fe oxyhydroxide, ferrihydrite, and schwertmannite from Beatson. Precipitates occurring in the form of loose, flocculant coatings were harvested using a syringe and concentrated in the field by repetitive decanting. Thicker accumulations were either scraped gently from rocks using a stainless steel spatula or were scooped directly into receptacles (polyethylene jars or plastic heavy-duty zippered bags). Most precipitate samples contain small amounts of sedimentary detritus. With three jarosite-bearing samples from Ellamar, an attempt was made to separate the precipitate from the heavy-mineral fraction of the sediment. In this procedure, the sample was stirred in a graduated cylinder containing deionized water. The jarosite-rich suspension was decanted onto analytical filter paper and air dried before analysis. Eleven precipitate samples from the three mine sites were analyzed in laboratories of the U.S. Geological Survey (USGS) in Denver, Colorado (table 8). Major and trace elements were determined by inductively coupled plasma-mass spectrometry following multiacid (HCl-HNO3-HClO4-HF) digestion (Briggs and Meier, 2002), except for mercury, which was analyzed by cold-vapor atomic absorption spectroscopy (Brown and others, 2002a). X-ray diffraction (XRD) analyses were performed on powdered samples (<200 mesh) by S. Sutley of the USGS. Additional details regarding sample preparation and detection limits are found in Taggert (2002). Discussions of the precipitate chemistry and associated microbial communities are presented in Koski and others (2008) and Foster and others (2008), respectively.

  15. Volumetric Spectroscopic Imaging of Glioblastoma Multiforme Radiation Treatment Volumes

    Energy Technology Data Exchange (ETDEWEB)

    Parra, N. Andres [Department of Radiation Oncology, University of Miami Miller School of Medicine, Miami, Florida (United States); Maudsley, Andrew A. [Department of Radiology, University of Miami Miller School of Medicine, Miami, Florida (United States); Gupta, Rakesh K. [Department of Radiology and Imaging, Fortis Memorial Research Institute, Gurgaon, Haryana (India); Ishkanian, Fazilat; Huang, Kris [Department of Radiation Oncology, University of Miami Miller School of Medicine, Miami, Florida (United States); Walker, Gail R. [Biostatistics and Bioinformatics Core Resource, Sylvester Cancer Center, University of Miami Miller School of Medicine, Miami, Florida (United States); Padgett, Kyle [Department of Radiation Oncology, University of Miami Miller School of Medicine, Miami, Florida (United States); Department of Radiology, University of Miami Miller School of Medicine, Miami, Florida (United States); Roy, Bhaswati [Department of Radiology and Imaging, Fortis Memorial Research Institute, Gurgaon, Haryana (India); Panoff, Joseph; Markoe, Arnold [Department of Radiation Oncology, University of Miami Miller School of Medicine, Miami, Florida (United States); Stoyanova, Radka, E-mail: RStoyanova@med.miami.edu [Department of Radiation Oncology, University of Miami Miller School of Medicine, Miami, Florida (United States)

    2014-10-01

    Purpose: Magnetic resonance (MR) imaging and computed tomography (CT) are used almost exclusively in radiation therapy planning of glioblastoma multiforme (GBM), despite their well-recognized limitations. MR spectroscopic imaging (MRSI) can identify biochemical patterns associated with normal brain and tumor, predominantly by observation of choline (Cho) and N-acetylaspartate (NAA) distributions. In this study, volumetric 3-dimensional MRSI was used to map these compounds over a wide region of the brain and to evaluate metabolite-defined treatment targets (metabolic tumor volumes [MTV]). Methods and Materials: Volumetric MRSI with effective voxel size of ∼1.0 mL and standard clinical MR images were obtained from 19 GBM patients. Gross tumor volumes and edema were manually outlined, and clinical target volumes (CTVs) receiving 46 and 60 Gy were defined (CTV{sub 46} and CTV{sub 60}, respectively). MTV{sub Cho} and MTV{sub NAA} were constructed based on volumes with high Cho and low NAA relative to values estimated from normal-appearing tissue. Results: The MRSI coverage of the brain was between 70% and 76%. The MTV{sub NAA} were almost entirely contained within the edema, and the correlation between the 2 volumes was significant (r=0.68, P=.001). In contrast, a considerable fraction of MTV{sub Cho} was outside of the edema (median, 33%) and for some patients it was also outside of the CTV{sub 46} and CTV{sub 60}. These untreated volumes were greater than 10% for 7 patients (37%) in the study, and on average more than one-third (34.3%) of the MTV{sub Cho} for these patients were outside of CTV{sub 60}. Conclusions: This study demonstrates the potential usefulness of whole-brain MRSI for radiation therapy planning of GBM and revealed that areas of metabolically active tumor are not covered by standard RT volumes. The described integration of MTV into the RT system will pave the way to future clinical trials investigating outcomes in patients treated based on

  16. Volumetric capnography for the evaluation of chronic airways diseases

    Directory of Open Access Journals (Sweden)

    Veronez L

    2014-09-01

    Full Text Available Liliani de Fátima Veronez,1 Monica Corso Pereira,2 Silvia Maria Doria da Silva,2 Luisa Affi Barcaui,2 Eduardo Mello De Capitani,2 Marcos Mello Moreira,2 Ilma Aparecida Paschoalz2 1Department of Physical Therapy, University of Votuporanga (Educational Foundation of Votuporanga, Votuporanga, 2Department of Internal Medicine, School of Medical Sciences, State University of Campinas (UNICAMP, Campinas, Sao Paulo, BrazilBackground: Obstructive lung diseases of different etiologies present with progressive peripheral airway involvement. The peripheral airways, known as the silent lung zone, are not adequately evaluated with conventional function tests. The principle of gas washout has been used to detect pulmonary ventilation inhomogeneity and to estimate the location of the underlying disease process. Volumetric capnography (VC analyzes the pattern of CO2 elimination as a function of expired volume.Objective: To measure normalized phase 3 slopes with VC in patients with non-cystic fibrosis bronchiectasis (NCB and in bronchitic patients with chronic obstructive pulmonary disease (COPD in order to compare the slopes obtained for the groups.Methods: NCB and severe COPD were enrolled sequentially from an outpatient clinic (Hospital of the State University of Campinas. A control group was established for the NCB group, paired by sex and age. All subjects performed spirometry, VC, and the 6-Minute Walk Test (6MWT. Two comparisons were made: NCB group versus its control group, and NCB group versus COPD group. The project was approved by the ethical committee of the institution. Statistical tests used were Wilcoxon or Student’s t-test; P<0.05 was considered to be a statistically significant difference.Results: Concerning the NCB group (N=20 versus the control group (N=20, significant differences were found in body mass index and in several functional variables (spirometric, VC, 6MWT with worse results observed in the NCB group. In the comparison between

  17. Widespread Volumetric Brain Changes following Tooth Loss in Female Mice

    Science.gov (United States)

    Avivi-Arber, Limor; Seltzer, Ze'ev; Friedel, Miriam; Lerch, Jason P.; Moayedi, Massieh; Davis, Karen D.; Sessle, Barry J.

    2017-01-01

    Tooth loss is associated with altered sensory, motor, cognitive and emotional functions. These changes vary highly in the population and are accompanied by structural and functional changes in brain regions mediating these functions. It is unclear to what extent this variability in behavior and function is caused by genetic and/or environmental determinants and which brain regions undergo structural plasticity that mediates these changes. Thus, the overall goal of our research program is to identify genetic variants that control structural and functional plasticity following tooth loss. As a step toward this goal, here our aim was to determine whether structural magnetic resonance imaging (sMRI) is sensitive to detect quantifiable volumetric differences in the brains of mice of different genetic background receiving tooth extraction or sham operation. We used 67 adult female mice of 7 strains, comprising the A/J (A) and C57BL/6J (B) strains and a randomly selected sample of 5 of the 23 AXB-BXA strains (AXB1, AXB4, AXB24, BXA14, BXA24) that were produced from the A and B parental mice by recombinations and inbreeding. This panel of 25 inbred strains of genetically diverse inbred strains of mice is used for mapping chromosomal intervals throughout the genome that harbor candidate genes controlling the phenotypic variance of any trait under study. Under general anesthesia, 39 mice received extraction of 3 right maxillary molar teeth and 28 mice received sham operation. On post-extraction day 21, post-mortem whole-brain high-resolution sMRI was used to quantify the volume of 160 brain regions. Compared to sham operation, tooth extraction was associated with a significantly reduced regional and voxel-wise volumes of cortical brain regions involved in processing somatosensory, motor, cognitive and emotional functions, and increased volumes in subcortical sensorimotor and temporal limbic forebrain regions including the amygdala. Additionally, comparison of the 10 BXA14

  18. Hepatosplenic volumetric assessment at MDCT for staging liver fibrosis.

    Science.gov (United States)

    Pickhardt, Perry J; Malecki, Kyle; Hunt, Oliver F; Beaumont, Claire; Kloke, John; Ziemlewicz, Timothy J; Lubner, Meghan G

    2017-07-01

    To investigate hepatosplenic volumetry at MDCT for non-invasive prediction of hepatic fibrosis. Hepatosplenic volume analysis in 624 patients (mean age, 48.8 years; 311 M/313 F) at MDCT was performed using dedicated software and compared against pathological fibrosis stage (F0 = 374; F1 = 48; F2 = 40; F3 = 65; F4 = 97). The liver segmental volume ratio (LSVR) was defined by Couinaud segments I-III over segments IV-VIII. All pre-cirrhotic fibrosis stages (METAVIR F1-F3) were based on liver biopsy within 1 year of MDCT. LSVR and total splenic volumes increased with stage of fibrosis, with mean(±SD) values of: F0: 0.26 ± 0.06 and 215.1 ± 88.5 mm(3); F1: 0.25 ± 0.08 and 294.8 ± 153.4 mm(3); F2: 0.331 ± 0.12 and 291.6 ± 197.1 mm(3); F3: 0.39 ± 0.15 and 509.6 ± 402.6 mm(3); F4: 0.56 ± 0.30 and 790.7 ± 450.3 mm(3), respectively. Total hepatic volumes showed poor discrimination (F0: 1674 ± 320 mm(3); F4: 1631 ± 691 mm(3)). For discriminating advanced fibrosis (≥F3), the ROC AUC values for LSVR, total liver volume, splenic volume and LSVR/spleen combined were 0.863, 0.506, 0.890 and 0.947, respectively. Relative changes in segmental liver volumes and total splenic volume allow for non-invasive staging of hepatic fibrosis, whereas total liver volume is a poor predictor. Unlike liver biopsy or elastography, these CT volumetric biomarkers can be obtained retrospectively on routine scans obtained for other indications. • Regional changes in hepatic volume (LSVR) correlate well with degree of fibrosis. • Total liver volume is a very poor predictor of underlying fibrosis. • Total splenic volume is associated with the degree of hepatic fibrosis. • Hepatosplenic volume assessment is comparable to elastography for staging fibrosis. • Unlike elastography, volumetric analysis can be performed retrospectively.

  19. Volumetric and MGMT parameters in glioblastoma patients: Survival analysis

    Directory of Open Access Journals (Sweden)

    Iliadis Georgios

    2012-01-01

    Full Text Available Abstract Background In this study several tumor-related volumes were assessed by means of a computer-based application and a survival analysis was conducted to evaluate the prognostic significance of pre- and postoperative volumetric data in patients harboring glioblastomas. In addition, MGMT (O6-methylguanine methyltransferase related parameters were compared with those of volumetry in order to observe possible relevance of this molecule in tumor development. Methods We prospectively analyzed 65 patients suffering from glioblastoma (GBM who underwent radiotherapy with concomitant adjuvant temozolomide. For the purpose of volumetry T1 and T2-weighted magnetic resonance (MR sequences were used, acquired both pre- and postoperatively (pre-radiochemotherapy. The volumes measured on preoperative MR images were necrosis, enhancing tumor and edema (including the tumor and on postoperative ones, net-enhancing tumor. Age, sex, performance status (PS and type of operation were also included in the multivariate analysis. MGMT was assessed for promoter methylation with Multiplex Ligation-dependent Probe Amplification (MLPA, for RNA expression with real time PCR, and for protein expression with immunohistochemistry in a total of 44 cases with available histologic material. Results In the multivariate analysis a negative impact was shown for pre-radiochemotherapy net-enhancing tumor on the overall survival (OS (p = 0.023 and for preoperative necrosis on progression-free survival (PFS (p = 0.030. Furthermore, the multivariate analysis confirmed the importance of PS in PFS and OS of patients. MGMT promoter methylation was observed in 13/23 (43.5% evaluable tumors; complete methylation was observed in 3/13 methylated tumors only. High rate of MGMT protein positivity (> 20% positive neoplastic nuclei was inversely associated with pre-operative tumor necrosis (p = 0.021. Conclusions Our findings implicate that volumetric parameters may have a significant role in

  20. Metal particle's precipitation behavior in direct reading ferrography precipitator tube

    Institute of Scientific and Technical Information of China (English)

    尹凤福; 李谋渭

    2004-01-01

    A new metal particle monitoring instrument was developed by improving the traditional direct reading ferrography. The precipitation behaviors of sub-magnetic particles, magnetic particles, and the mixture of these particles were examined with the instrument. The results show that the precipitation behavior of sub-magnetic metal particles of copper and aluminum is not random as it was believed previously. The sub-magnetic particles show a distribution in the precipitator tube, almost the same as the deposition curves as the magnetic particles have. The deposition amount of particles is increased in the oil which consists of several different kinds of particles. On the base of these experiments, a new index used for the total quantity of wear was redefined.

  1. Intensity modulated radiotherapy versus volumetric modulated arc therapy in breast cancer: A comparative dosimetric analysis

    Directory of Open Access Journals (Sweden)

    KR Muralidhar

    2015-01-01

    Full Text Available Purpose: Intensity modulated radiotherapy (IMRT and volumetric modulated arc therapy (VMAT has the capacity to optimize the dose distribution. We analyzed the dosimetric differences of plans in treatment planning system (TPS between VMAT and IMRT in treating breast cancer. Methods: Fourteen patients were simulated, planned, and treated with VMAT using single, double or partial arcs. IMRT treatments were generated using 4 to 5 tangential IMRT fields for the same patients. All treatment plans were planned for 50 Gy in 25 fractions. The VMAT and IMRT plans were compared using the planning target volume (PTV dose and doses to the other organs at risk (OARs. Results: For the PTV, comparable minimum, mean, maximum, median, and modal dose as well equivalent sphere diameter of the structure (Equis were observed between VMAT and IMRT plans and found that these values were significantly equal in both techniques. The right lung mean and modal doses were considerably higher in VMAT plans while maximum value was considerably lower when compared with IMRT plans. The left lung mean and modal doses were higher with VMAT while maximum doses were higher in IMRT plans. The mean dose to the heart and maximum dose to the spinal cord was lower with IMRT. The mean dose to the body was higher in VMAT plans while the maximum dose was higher in IMRT plans. Conclusion: Four field tangential IMRT delivered comparable PTV dose with generally less dose to normal tissues in our breast cancer treatment study. The IMRT plans typically had more favourable dose characteristics to the lung, heart, and spinal cord and body dose when compared with VMAT. The only minor advantage of VMAT for breast cases was slightly better PTV coverage.

  2. The Global Precipitation Measurement Mission

    Science.gov (United States)

    Jackson, Gail

    2014-05-01

    The Global Precipitation Measurement (GPM) mission's Core satellite, scheduled for launch at the end of February 2014, is well designed estimate precipitation from 0.2 to 110 mm/hr and to detect falling snow. Knowing where and how much rain and snow falls globally is vital to understanding how weather and climate impact both our environment and Earth's water and energy cycles, including effects on agriculture, fresh water availability, and responses to natural disasters. The design of the GPM Core Observatory is an advancement of the Tropical Rainfall Measuring Mission (TRMM)'s highly successful rain-sensing package [3]. The cornerstone of the GPM mission is the deployment of a Core Observatory in a unique 65o non-Sun-synchronous orbit to serve as a physics observatory and a calibration reference to improve precipitation measurements by a constellation of 8 or more dedicated and operational, U.S. and international passive microwave sensors. The Core Observatory will carry a Ku/Ka-band Dual-frequency Precipitation Radar (DPR) and a multi-channel (10-183 GHz) GPM Microwave Radiometer (GMI). The DPR will provide measurements of 3-D precipitation structures and microphysical properties, which are key to achieving a better understanding of precipitation processes and improving retrieval algorithms for passive microwave radiometers. The combined use of DPR and GMI measurements will place greater constraints on possible solutions to radiometer retrievals to improve the accuracy and consistency of precipitation retrievals from all constellation radiometers. Furthermore, since light rain and falling snow account for a significant fraction of precipitation occurrence in middle and high latitudes, the GPM instruments extend the capabilities of the TRMM sensors to detect falling snow, measure light rain, and provide, for the first time, quantitative estimates of microphysical properties of precipitation particles. The GPM Core Observatory was developed and tested at NASA

  3. Are hourly precipitation extremes increasing faster than daily precipitation extremes?

    Science.gov (United States)

    Barbero, Renaud; Fowler, Hayley; Blenkinsop, Stephen; Lenderink, Geert

    2016-04-01

    Extreme precipitation events appear to be increasing with climate change in many regions of the world, including the United States. These extreme events have large societal impacts, as seen during the recent Texas-Oklahoma flooding in May 2015 which caused several billion in damages and left 47 deaths in its path. Better understanding of past changes in the characteristics of extreme rainfall events is thus critical for reliable projections of future changes. Although it has been documented in several studies that daily precipitation extremes are increasing across parts of the contiguous United States, very few studies have looked at hourly extremes. However, this is of primary importance as recent studies on the temperature scaling of extreme precipitation have shown that increases above the Clausius-Clapeyron (~ 7% °C-1) are possible for hourly precipitation. In this study, we used hourly precipitation data (HPD) from the National Climatic Data Center and extracted more than 1,000 stations across the US with more than 40 years of data spanning the period 1950-2010. As hourly measurements are often associated with a range of issues, the data underwent multiple quality control processes to exclude erroneous data. While no significant changes were found in annual maximum precipitation using both hourly and daily resolution datasets, significant increasing trends in terms of frequency of episodes exceeding present-day 95th percentiles of wet hourly/daily precipitation were observed across a significant portion of the US. The fraction of stations with significant increasing trends falls outside the confidence interval range during all seasons but the summer. While less than 12% of stations exhibit significant trends at the daily scale in the wintertime, more than 45% of stations, mostly clustered in central and Northern United States, show significant increasing trends at the hourly scale. This suggests that short-duration storms have increased faster than daily

  4. Towards Quantitative Ocean Precipitation Validation

    Science.gov (United States)

    Klepp, C.; Bakan, S.; Andersson, A.

    2009-04-01

    A thorough knowledge of global ocean precipitation is an indispensable prerequisite for the understanding and successful modelling of the global climate system as it is an important component of the water cycle. However, reliable detection of quantitative precipitation over the global oceans, especially at high latitudes during the cold season remains a challenging task for remote sensing and model based estimates. Quantitative ship validation data using reliable instruments for measuring rain and snowfall hardly exist but are highly demanded for ground validation of such products. The satellite based HOAPS (Hamburg Ocean Atmosphere Parameters and Fluxes from Satellite Data) climatology contains fields of precipitation, evaporation and the resulting freshwater flux along with 12 additional atmospheric parameters over the global ice-free ocean between 1987 and 2005. Except for the NOAA Pathfinder SST, all basic state variables are calculated from SSM/I passive microwave radiometer measurements. HOAPS contains three main data subsets that originate from one common pixel-level data source. Gridded 0.5 degree monthly, pentad and twice daily data products are freely available from www.hoaps.org. Especially for North Atlantic mid-latitude mix-phase precipitation, the HOAPS precipitation retrieval has been investigated in some depth. This analysis revealed that the HOAPS retrieval qualitatively well represents cyclonic and intense mesoscale precipitation in agreement with ship observations and Cloudsat data, while GPCP, ECMWF forecast, ERA-40 and regional model data miss mesoscale precipitation substantially. As the differences between the investigated data sets are already large under mix-phase precipitation conditions, further work is carried out on snowfall validation during the cold season at high-latitudes. A Norwegian Sea field campaign in winter 2005 was carried out using an optical disdrometer capable of measuring quantitative amounts of snowfall over the ocean

  5. 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.

  6. Is there a role for the use of volumetric cone beam computed tomography in periodontics?

    Science.gov (United States)

    du Bois, A H; Kardachi, B; Bartold, P M

    2012-03-01

    Volumetric computed cone beam tomography offers a number of significant advantages over conventional intraoral and extraoral panoramic radiography, as well as computed tomography. To date, periodontal diagnosis has relied heavily on the assessment of both intraoral radiographs and extraoral panoramic radiographs. With emerging technology in radiology there has been considerable interest in the role that volumetric cone beam computed tomography might play in periodontal diagnostics. This narrative reviews the current evidence and considers whether there is a role for volumetric cone beam computed tomography in periodontics.

  7. Parkinson's disease: diagnostic utility of volumetric imaging

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Wei-Che; Chen, Meng-Hsiang [Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Department of Diagnostic Radiology, Kaohsiung (China); Chou, Kun-Hsien [National Yang-Ming University, Brain Research Center, Taipei (China); Lee, Pei-Lin [National Yang-Ming University, Department of Biomedical Imaging and Radiological Sciences, Taipei (China); Tsai, Nai-Wen; Lu, Cheng-Hsien [Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Department of Neurology, Kaohsiung (China); Chen, Hsiu-Ling [Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Department of Diagnostic Radiology, Kaohsiung (China); National Yang-Ming University, Department of Biomedical Imaging and Radiological Sciences, Taipei (China); Hsu, Ai-Ling [National Taiwan University, Institute of Biomedical Electronics and Bioinformatics, Taipei (China); Huang, Yung-Cheng [Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Department of Nuclear Medicine, Kaohsiung (China); Lin, Ching-Po [National Yang-Ming University, Brain Research Center, Taipei (China); National Yang-Ming University, Department of Biomedical Imaging and Radiological Sciences, Taipei (China)

    2017-04-15

    This paper aims to examine the effectiveness of structural imaging as an aid in the diagnosis of Parkinson's disease (PD). High-resolution T{sub 1}-weighted magnetic resonance imaging was performed in 72 patients with idiopathic PD (mean age, 61.08 years) and 73 healthy subjects (mean age, 58.96 years). The whole brain was parcellated into 95 regions of interest using composite anatomical atlases, and region volumes were calculated. Three diagnostic classifiers were constructed using binary multiple logistic regression modeling: the (i) basal ganglion prior classifier, (ii) data-driven classifier, and (iii) basal ganglion prior/data-driven hybrid classifier. Leave-one-out cross validation was used to unbiasedly evaluate the predictive accuracy of imaging features. Pearson's correlation analysis was further performed to correlate outcome measurement using the best PD classifier with disease severity. Smaller volume in susceptible regions is diagnostic for Parkinson's disease. Compared with the other two classifiers, the basal ganglion prior/data-driven hybrid classifier had the highest diagnostic reliability with a sensitivity of 74%, specificity of 75%, and accuracy of 74%. Furthermore, outcome measurement using this classifier was associated with disease severity. Brain structural volumetric analysis with multiple logistic regression modeling can be a complementary tool for diagnosing PD. (orig.)

  8. Volumetric Analysis of Regional Cerebral Development in Preterm Children

    Science.gov (United States)

    Kesler, Shelli R.; Ment, Laura R.; Vohr, Betty; Pajot, Sarah K.; Schneider, Karen C.; Katz, Karol H.; Ebbitt, Timothy B.; Duncan, Charles C.; Makuch, Robert W.; Reiss, Allan L.

    2011-01-01

    Preterm birth is frequently associated with both neuropathologic and cognitive sequelae. This study examined cortical lobe, subcortical, and lateral ventricle development in association with perinatal variables and cognitive outcome. High-resolution volumetric magnetic resonance imaging scans were acquired and quantified using advanced image processing techniques. Seventy-three preterm and 33 term control children ages 7.3-11.4 years were included in the study. Results indicated disproportionately enlarged parietal and frontal gray matter, occipital horn, and ventricular body, as well as reduced temporal and subcortical gray volumes in preterm children compared with control subjects. Birth weight was negatively correlated with parietal and frontal gray, as well as occipital horn volumes. Intraventricular hemorrhage was associated with reduced subcortical gray matter. Ventricular cerebrospinal fluid was negatively correlated with subcortical gray matter volumes but not with white matter volumes. Maternal education was the strongest predictor of cognitive function in the preterm group. Preterm birth appears to be associated with disorganized cortical development, possibly involving disrupted synaptic pruning and neural migration. Lower birth weight and the presence of intraventricular hemorrhage may increase the risk for neuroanatomic abnormality. PMID:15519112

  9. Volumetric microscale particle tracking velocimetry (PTV) in porous media

    Science.gov (United States)

    Guo, Tianqi; Aramideh, Soroush; Ardekani, Arezoo M.; Vlachos, Pavlos P.

    2016-11-01

    The steady-state flow through refractive-index-matched glass bead microchannels is measured using microscopic particle tracking velocimetry (μPTV). A novel technique is developed to volumetrically reconstruct particles from oversampled two-dimensional microscopic images of fluorescent particles. Fast oversampling of the quasi-steady-state flow field in the lateral direction is realized by a nano-positioning piezo stage synchronized with a fast CMOS camera. Experiments at different Reynolds numbers are carried out for flows through a series of both monodispersed and bidispersed glass bead microchannels with various porosities. The obtained velocity fields at pore-scale (on the order of 10 μm) are compared with direct numerical simulations (DNS) conducted in the exact same geometries reconstructed from micro-CT scans of the glass bead microchannels. The developed experimental method would serve as a new approach for exploring the flow physics at pore-scale in porous media, and also provide benchmark measurements for validation of numerical simulations.

  10. Buoyancy Driven Mixing with Continuous Volumetric Energy Deposition

    Science.gov (United States)

    Wachtor, Adam J.; Jebrail, Farzaneh F.; Dennisen, Nicholas A.; Andrews, Malcolm J.; Gore, Robert A.

    2014-11-01

    An experiment involving a miscible fluid pair is presented which transitioned from a Rayleigh-Taylor (RT) stable to RT unstable configuration through continuous volumetric energy deposition (VED) by microwave radiation. Initially a light, low microwave absorbing fluid rested above a heavier, more absorbing fluid. The alignment of the density gradient with gravity made the system stable, and the Atwood number (At) for the initial setup was approximately -0.12. Exposing the fluid pair to microwave radiation preferentially heated the bottom fluid, and caused its density to drop due to thermal expansion. As heating of the bottom fluid continued, the At varied from negative to positive, and after the system passed through the neutral stability point, At = 0, buoyancy driven mixing ensued. Continuous VED caused the At to continue increasing and further drive the mixing process. Successful VED mixing required careful design of the fluid pair used in the experiment. Therefore, fluid selection is discussed, along with challenges and limitations of data collection using the experimental microwave facility. Experimental and model predictions of the neutral stability point, and onset of buoyancy driven mixing, are compared, and differences with classical, constant At RT driven turbulence are discussed.

  11. FELIX 3D display: an interactive tool for volumetric imaging

    Science.gov (United States)

    Langhans, Knut; Bahr, Detlef; Bezecny, Daniel; Homann, Dennis; Oltmann, Klaas; Oltmann, Krischan; Guill, Christian; Rieper, Elisabeth; Ardey, Goetz

    2002-05-01

    The FELIX 3D display belongs to the class of volumetric displays using the swept volume technique. It is designed to display images created by standard CAD applications, which can be easily imported and interactively transformed in real-time by the FELIX control software. The images are drawn on a spinning screen by acousto-optic, galvanometric or polygon mirror deflection units with integrated lasers and a color mixer. The modular design of the display enables the user to operate with several equal or different projection units in parallel and to use appropriate screens for the specific purpose. The FELIX 3D display is a compact, light, extensible and easy to transport system. It mainly consists of inexpensive standard, off-the-shelf components for an easy implementation. This setup makes it a powerful and flexible tool to keep track with the rapid technological progress of today. Potential applications include imaging in the fields of entertainment, air traffic control, medical imaging, computer aided design as well as scientific data visualization.

  12. 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.

  13. Optical artefact characterization and correction in volumetric scintillation dosimetry

    Science.gov (United States)

    Robertson, Daniel; Hui, Cheukkai; Archambault, Louis; Mohan, Radhe; Beddar, Sam

    2014-01-01

    The goals of this study were (1) to characterize the optical artefacts affecting measurement accuracy in a volumetric liquid scintillator detector, and (2) to develop methods to correct for these artefacts. The optical artefacts addressed were photon scattering, refraction, camera perspective, vignetting, lens distortion, the lens point spread function, stray radiation, and noise in the camera. These artefacts were evaluated by theoretical and experimental means, and specific correction strategies were developed for each artefact. The effectiveness of the correction methods was evaluated by comparing raw and corrected images of the scintillation light from proton pencil beams against validated Monte Carlo calculations. Blurring due to the lens and refraction at the scintillator tank-air interface were found to have the largest effect on the measured light distribution, and lens aberrations and vignetting were important primarily at the image edges. Photon scatter in the scintillator was not found to be a significant source of artefacts. The correction methods effectively mitigated the artefacts, increasing the average gamma analysis pass rate from 66% to 98% for gamma criteria of 2% dose difference and 2 mm distance to agreement. We conclude that optical artefacts cause clinically meaningful errors in the measured light distribution, and we have demonstrated effective strategies for correcting these optical artefacts.

  14. An MRI-based semiautomated volumetric quantification of hip osteonecrosis

    Energy Technology Data Exchange (ETDEWEB)

    Malizos, K.N.; Siafakas, M.S.; Karachalios, T.S. [Dept. of Orthopaedics, Univ. of Thessalia, Larissa (Greece); Fotiadis, D.I. [Dept. of Computer Science, Univ. of Ioannina (Greece); Soucacos, P.N. [Dept. of Orthopaedic Surgery, Univ. of Ioannina (Greece)

    2001-12-01

    Objective: To objectively and precisely define the spatial distribution of osteonecrosis and to investigate the influence of various factors including etiology. Design: A volumetric method is presented to describe the size and spatial distribution of necrotic lesions of the femoral head, using MRI scans. The technique is based on the definition of an equivalent sphere model for the femoral head. Patients: The gender, age, number of hips involved, disease duration, pain intensity, limping disability and etiology were correlated with the distribution of the pathologic bone. Seventy-nine patients with 122 hips affected by osteonecrosis were evaluated. Results: The lesion size ranged from 7% to 73% of the sphere equivalent. The lateral octants presented considerable variability, ranging from wide lateral lesions extending beyond the lip of the acetabulum, to narrow medial lesions, leaving a lateral supporting pillar of intact bone. Patients with sickle cell disease and steroid administration presented the largest lesions. The extent of the posterior superior medial octant involvement correlated with the symptom intensity, a younger age and male gender. Conclusion: The methodology presented here has proven a reliable and straightforward imaging tool for precise assessment of necrotic lesions. It also enables us to target accurately the drilling and grafting procedures. (orig.)

  15. Illustration-inspired depth enhanced volumetric medical visualization.

    Science.gov (United States)

    Svakhine, Nikolai A; Ebert, David S; Andrews, William M

    2009-01-01

    Volume illustration can be used to provide insight into source data from CT/MRI scanners in much the same way as medical illustration depicts the important details of anatomical structures. As such, proven techniques used in medical illustration should be transferable to volume illustration, providing scientists with new tools to visualize their data. In recent years, a number of techniques have been developed to enhance the rendering pipeline and create illustrative effects similar to the ones found in medical textbooks and surgery manuals. Such effects usually highlight important features of the subject while subjugating its context and providing depth cues for correct perception. Inspired by traditional visual and line-drawing techniques found in medical illustration, we have developed a collection of fast algorithms for more effective emphasis/de-emphasis of data as well as conveyance of spatial relationships. Our techniques utilize effective outlining techniques and selective depth enhancement to provide perceptual cues of object importance as well as spatial relationships in volumetric datasets. Moreover, we have used illustration principles to effectively combine and adapt basic techniques so that they work together to provide consistent visual information and a uniform style.

  16. Connectivity network measures predict volumetric atrophy in mild cognitive impairment.

    Science.gov (United States)

    Nir, Talia M; Jahanshad, Neda; Toga, Arthur W; Bernstein, Matt A; Jack, Clifford R; Weiner, Michael W; Thompson, Paul M

    2015-01-01

    Alzheimer's disease (AD) is characterized by cortical atrophy and disrupted anatomic connectivity, and leads to abnormal interactions between neural systems. Diffusion-weighted imaging (DWI) and graph theory can be used to evaluate major brain networks and detect signs of a breakdown in network connectivity. In a longitudinal study using both DWI and standard magnetic resonance imaging (MRI), we assessed baseline white-matter connectivity patterns in 30 subjects with mild cognitive impairment (MCI, mean age 71.8 ± 7.5 years, 18 males and 12 females) from the Alzheimer's Disease Neuroimaging Initiative. Using both standard MRI-based cortical parcellations and whole-brain tractography, we computed baseline connectivity maps from which we calculated global "small-world" architecture measures, including mean clustering coefficient and characteristic path length. We evaluated whether these baseline network measures predicted future volumetric brain atrophy in MCI subjects, who are at risk for developing AD, as determined by 3-dimensional Jacobian "expansion factor maps" between baseline and 6-month follow-up anatomic scans. This study suggests that DWI-based network measures may be a novel predictor of AD progression.

  17. Femoral head osteonecrosis: Volumetric MRI assessment and outcome

    Energy Technology Data Exchange (ETDEWEB)

    Bassounas, Athanasios E. [Department of Medical Physics, School of Medicine, University of Ioannina, GR 451 10 Ioannina (Greece); Karantanas, Apostolos H. [Department of Radiology, School of Medicine, University of Crete, Heraklion, GR 711 10 (Greece); Fotiadis, Dimitrios I. [Unit of Medical Technology and Intelligent Information Systems, Department of Computer Science, University of Ioannina and Biomedical Research Institute-FORTH, GR 451 10 Ioannina (Greece); Malizos, Konstantinos N. [Orthopaedic Department, Medical School, University of Thessalia, GR 412 22 Larissa (Greece)]. E-mail: kmalizos@otenet.gr

    2007-07-15

    Effective treatment of femoral head osteonecrosis (FHON) requires early diagnosis and accurate assessment of the disease severity. The ability to predict in the early stages the risk of collapse is important for selecting a joint salvage procedure. The aim of the present study was to evaluate the outcome in patients treated with vascularized fibular grafts in relation to preoperative MR imaging volumetry. We studied 58 patients (87 hips) with FHON. A semi-automated octant-based lesion measurement method, previously described, was performed on the T1-w MR images. The mean time of postoperative follow-up was 7.8 years. Sixty-three hips were successful and 24 failed and converted to total hip arthroplasty within a period of 2-4 years after the initial operation. The rate of failures for hips of male patients was higher than in female patients. The mean lesion size was 28% of the sphere equivalent of the femoral head, 24 {+-} 12% for the successful hips and 37 {+-} 9% for the failed (p < 0.001). The most affected octants were antero-supero-medial (58 {+-} 26%) and postero-supero-medial (54 {+-} 31%). All but postero-infero-medial and postero-infero-lateral octants, showed statistically significant differences in the lesion size between patients with successful and failed hips. In conclusion, the volumetric analysis of preoperative MRI provides useful information with regard to a successful outcome in patients treated with vascularized fibular grafts.

  18. Three-dimensional volumetric quantification of fat loss following cryolipolysis.

    Science.gov (United States)

    Garibyan, Lilit; Sipprell, William H; Jalian, H Ray; Sakamoto, Fernanda H; Avram, Mathew; Anderson, R Rox

    2014-02-01

    Cryolipolysis is a noninvasive and well-tolerated treatment for reduction of localized subcutaneous fat. Although several studies demonstrate the safety and efficacy of this procedure, volumetric fat reduction from this treatment has not been quantified. This prospective study investigated the change in volume of fat after cryolipolysis treatment using three-dimensional (3D) photography. A prospective study of subjects treated with cryolipolysis on the flank (love handle) was performed at Massachusetts General Hospital. Volume measurements were performed with a Canfield Scientific Vectra three-dimensional camera and software to evaluate the amount of post procedure volume change. Clinical outcomes were assessed with caliper measurements, subject surveys, and blinded physician assessment of photographs. Eleven subjects were enrolled in this study. Each subject underwent a single cycle of cryolipolysis to one flank. The untreated flank served as an internal control. The follow-up time after treatment was 2 months. The mean amount of calculated absolute fat volume loss using 3D photography from baseline to 2 months follow-up visit was 56.2 ± 25.6 from the treatment site and 16.6 ± 17.6 cc from the control (P fat removal methodology that on average leads to 39.6 cc of fat loss of the treated flank at 2 months after a single treatment cycle. © 2013 Wiley Periodicals, Inc.

  19. Cortical thickness and brain volumetric analysis in body dysmorphic disorder.

    Science.gov (United States)

    Madsen, Sarah K; Zai, Alex; Pirnia, Tara; Arienzo, Donatello; Zhan, Liang; Moody, Teena D; Thompson, Paul M; Feusner, Jamie D

    2015-04-30

    Individuals with body dysmorphic disorder (BDD) suffer from preoccupations with perceived defects in physical appearance, causing severe distress and disability. Although BDD affects 1-2% of the population, the neurobiology is not understood. Discrepant results in previous volumetric studies may be due to small sample sizes, and no study has investigated cortical thickness in BDD. The current study is the largest neuroimaging analysis of BDD. Participants included 49 medication-free, right-handed individuals with DSM-IV BDD and 44 healthy controls matched by age, sex, and education. Using high-resolution T1-weighted magnetic resonance imaging, we computed vertex-wise gray matter (GM) thickness on the cortical surface and GM volume using voxel-based morphometry. We also computed volumes in cortical and subcortical regions of interest. In addition to group comparisons, we investigated associations with symptom severity, insight, and anxiety within the BDD group. In BDD, greater anxiety was significantly associated with thinner GM in the left superior temporal cortex and greater GM volume in the right caudate nucleus. There were no significant differences in cortical thickness, GM volume, or volumes in regions of interest between BDD and control subjects. Subtle associations with clinical symptoms may characterize brain morphometric patterns in BDD, rather than large group differences in brain structure. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  20. Region-of-interest volumetric visual hull refinement

    KAUST Repository

    Knoblauch, Daniel

    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 hull reconstruction, resulting in a first 3D approximation of the target, followed by a region-of-interest estimation, tasked with identifying features of interest, which in turn are used to locally refine the voxel grid and extract a higher-resolution surface representation for those regions. This approach is illustrated for the reconstruction of avatars for use in tele-immersion environments, where head and hand regions are of higher interest. To allow reproducability and direct comparison a publicly available data set for human visual hull reconstruction is used. This paper shows that region-of-interest reconstruction of the target is faster and visually comparable to higher resolution focused visual hull reconstructions. This approach reduces the amount of data generated through the reconstruction, allowing faster post processing, as rendering or networking of the surface voxels. Reconstruction speeds support smooth interactions between the avatar and the virtual environment, while the improved resolution of its facial region and hands creates a higher-degree of immersion and potentially impacts the perception of body language, facial expressions and eye-to-eye contact. Copyright © 2010 by the Association for Computing Machinery, Inc.

  1. 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.

  2. Measurement of precipitation using lysimeters

    Science.gov (United States)

    Fank, Johann; Klammler, Gernot

    2013-04-01

    Austria's alpine foothill aquifers contain important drinking water resources, but are also used intensively for agricultural production. These groundwater bodies are generally recharged by infiltrating precipitation. A sustainable water resources management of these aquifers requires quantifying real evapotranspiration (ET), groundwater recharge (GR), precipitation (P) and soil water storage change (ΔS). While GR and ΔS can be directly measured by weighable lysimeters and P by separate precipitation gauges, ET is determined by solving the climatic water balance ET = P GR ± ΔS. According to WMO (2008) measurement of rainfall is strongly influenced by precipitation gauge errors. Most significant errors result from wind loss, wetting loss, evaporation loss, and due to in- and out-splashing of water. Measuring errors can be reduced by a larger area of the measuring gaugés surface and positioning the collecting vessel at ground level. Modern weighable lysimeters commonly have a surface of 1 m², are integrated into their typical surroundings of vegetation cover (to avoid oasis effects) and allow scaling the mass change of monolithic soil columns in high measuring accuracy (0.01 mm water equivalent) and high temporal resolution. Thus, also precipitation can be quantified by measuring the positive mass changes of the lysimeter. According to Meissner et al. (2007) also dew, fog and rime can be determined by means of highly precise weighable lysimeters. Furthermore, measuring precipitation using lysimeters avoid common measuring errors (WMO 2008) at point scale. Though, this method implicates external effects (background noise, influence of vegetation and wind) which affect the mass time series. While the background noise of the weighing is rather well known and can be filtered out of the mass time series, the influence of wind, which blows through the vegetation and affects measured lysimeter mass, cannot be corrected easily since there is no clear relation between

  3. Kinetics of asphaltene precipitation from crude oils

    Energy Technology Data Exchange (ETDEWEB)

    Maqbool, T.; Hussein, I.A.; Fogler, H.S. [Michigan Univ., Ann Arbor (United States). Dept. of Chemical Engineering

    2008-07-01

    The kinetics of asphaltene precipitation from crude oils was investigated using n-alkane precipitants. Recent studies have shown that there is a kinetic phenomenon associated with asphaltene precipitation. This study showed that the time needed to precipitate the asphaltenes can vary from a few minutes to several months, depending on the amount of n-alkane precipitant added. As such, the onset of asphaltene precipitation is a function of the concentration of precipitant and time. A technique to quantify the amount of asphaltenes precipitated as a function of time and precipitant concentration was presented. This study also investigated the kinetic effects caused by various precipitants. Optical microscopy was used to monitor the growth of asphaltene aggregates with time. Refractive index measurements provided further insight into the kinetics of asphaltene precipitation. Polarity based fractionation and dielectric constant measurements were used to compare the nature of asphaltenes precipitated early in the precipitation process with the asphaltenes precipitated at later times. It was concluded that asphaltenes precipitating at different times from the same crude oil-precipitant mixture are different from one another. 3 refs.

  4. The double identity of linguistic doubling.

    Science.gov (United States)

    Berent, Iris; Bat-El, Outi; Brentari, Diane; Dupuis, Amanda; Vaknin-Nusbaum, Vered

    2016-11-29

    Does knowledge of language consist of abstract principles, or is it fully embodied in the sensorimotor system? To address this question, we investigate the double identity of doubling (e.g., slaflaf, or generally, XX; where X stands for a phonological constituent). Across languages, doubling is known to elicit conflicting preferences at different levels of linguistic analysis (phonology vs. morphology). Here, we show that these preferences are active in the brains of individual speakers, and they are demonstrably distinct from sensorimotor pressures. We first demonstrate that doubling in novel English words elicits divergent percepts: Viewed as meaningless (phonological) forms, doubling is disliked (e.g., slaflaf linguistic preferences doubly dissociate from sensorimotor demands: A single stimulus can elicit diverse percepts, yet these percepts are invariant across stimulus modality--for speech and signs. These conclusions are in line with the possibility that some linguistic principles are abstract, and they apply broadly across language modality.

  5. Radar-Derived Quantitative Precipitation Estimation Based on Precipitation Classification

    Directory of Open Access Journals (Sweden)

    Lili Yang

    2016-01-01

    Full Text Available A method for improving radar-derived quantitative precipitation estimation is proposed. Tropical vertical profiles of reflectivity (VPRs are first determined from multiple VPRs. Upon identifying a tropical VPR, the event can be further classified as either tropical-stratiform or tropical-convective rainfall by a fuzzy logic (FL algorithm. Based on the precipitation-type fields, the reflectivity values are converted into rainfall rate using a Z-R relationship. In order to evaluate the performance of this rainfall classification scheme, three experiments were conducted using three months of data and two study cases. In Experiment I, the Weather Surveillance Radar-1988 Doppler (WSR-88D default Z-R relationship was applied. In Experiment II, the precipitation regime was separated into convective and stratiform rainfall using the FL algorithm, and corresponding Z-R relationships were used. In Experiment III, the precipitation regime was separated into convective, stratiform, and tropical rainfall, and the corresponding Z-R relationships were applied. The results show that the rainfall rates obtained from all three experiments match closely with the gauge observations, although Experiment II could solve the underestimation, when compared to Experiment I. Experiment III significantly reduced this underestimation and generated the most accurate radar estimates of rain rate among the three experiments.

  6. The Cambridge Double Star Atlas

    Science.gov (United States)

    MacEvoy, Bruce; Tirion, Wil

    2015-12-01

    Preface; What are double stars?; The binary orbit; Double star dynamics; Stellar mass and the binary life cycle; The double star population; Detecting double stars; Double star catalogs; Telescope optics; Preparing to observe; Helpful accessories; Viewing challenges; Next steps; Appendices: target list; Useful formulas; Double star orbits; Double star catalogs; The Greek alphabet.

  7. Double outlet right ventricle

    Science.gov (United States)

    ... medlineplus.gov/ency/article/007328.htm Double outlet right ventricle To use the sharing features on this page, please enable JavaScript. Double outlet right ventricle (DORV) is a heart disease that is ...

  8. On the Uncertain Future of the Volumetric 3D Display Paradigm

    Science.gov (United States)

    Blundell, Barry G.

    2017-06-01

    Volumetric displays permit electronically processed images to be depicted within a transparent physical volume and enable a range of cues to depth to be inherently associated with image content. Further, images can be viewed directly by multiple simultaneous observers who are able to change vantage positions in a natural way. On the basis of research to date, we assume that the technologies needed to implement useful volumetric displays able to support translucent image formation are available. Consequently, in this paper we review aspects of the volumetric paradigm and identify important issues which have, to date, precluded their successful commercialization. Potentially advantageous characteristics are outlined and demonstrate that significant research is still needed in order to overcome barriers which continue to hamper the effective exploitation of this display modality. Given the recent resurgence of interest in developing commercially viable general purpose volumetric systems, this discussion is of particular relevance.

  9. Volumetric study of the olfactory bulb in patients with chronic rhinonasal sinusitis using MRI

    Directory of Open Access Journals (Sweden)

    Reda A. Alarabawy

    2016-06-01

    Conclusions: MRI with volumetric analysis is a useful tool in assessment of the olfactory bulb volume in patients with olfactory loss and appears to be of help in assessment of the degree of recovery in patients after sinus surgery.

  10. Inkjet printing-based volumetric display projecting multiple full-colour 2D patterns

    Science.gov (United States)

    Hirayama, Ryuji; Suzuki, Tomotaka; Shimobaba, Tomoyoshi; Shiraki, Atsushi; Naruse, Makoto; Nakayama, Hirotaka; Kakue, Takashi; Ito, Tomoyoshi

    2017-04-01

    In this study, a method to construct a full-colour volumetric display is presented using a commercially available inkjet printer. Photoreactive luminescence materials are minutely and automatically printed as the volume elements, and volumetric displays are constructed with high resolution using easy-to-fabricate means that exploit inkjet printing technologies. The results experimentally demonstrate the first prototype of an inkjet printing-based volumetric display composed of multiple layers of transparent films that yield a full-colour three-dimensional (3D) image. Moreover, we propose a design algorithm with 3D structures that provide multiple different 2D full-colour patterns when viewed from different directions and experimentally demonstrate prototypes. It is considered that these types of 3D volumetric structures and their fabrication methods based on widely deployed existing printing technologies can be utilised as novel information display devices and systems, including digital signage, media art, entertainment and security.

  11. Effect of consolidation pressure on volumetric composition and stiffness of unidirectional flax fibre composites

    DEFF Research Database (Denmark)

    Aslan, Mustafa; Mehmood, S.; Madsen, Bo

    2013-01-01

    Unidirectional flax/polyethylene terephthalate composites are manufactured by filament winding, followed by compression moulding with low and high consolidation pressure, and with variable flax fibre content. The experimental data of volumetric composition and tensile stiffness are analysed with ...

  12. Mechanical properties, volumetric shrinkage and depth of cure of short fiber-reinforced resin composite.

    Science.gov (United States)

    Tsujimoto, Akimasa; Barkmeier, Wayne W; Takamizawa, Toshiki; Latta, Mark A; Miyazaki, Masashi

    2016-01-01

    The mechanical properties, volumetric shrinkage and depth of cure of a short fiber-reinforced resin composite (SFRC) were investigated in this study and compared to both a bulk fill resin composite (BFRC) and conventional glass/ceramic-filled resin composite (CGRC). Fracture toughness, flexural properties, volumetric shrinkage and depth of cure of the SFRC, BFRC and CGRC were measured. SFRC had significantly higher fracture toughness than BFRCs and CGRCs. The flexural properties of SFRC were comparable with BFRCs and CGRCs. SFRC showed significantly lower volumetric shrinkage than the other tested resin composites. The depth of cure of the SFRC was similar to BFRCs and higher than CGRCs. The data from this laboratory investigation suggests that SFRC exhibits improvements in fracture toughness, volumetric shrinkage and depth of cure when compared with CGRC, but depth of cure of SFRC was similar to BFRC.

  13. Review of prospects and challenges of eye tracking in volumetric imaging.

    Science.gov (United States)

    Venjakob, Antje C; Mello-Thoms, Claudia R

    2016-01-01

    While eye tracking research in conventional radiography has flourished over the past decades, the number of eye tracking studies that looked at multislice images lags behind. A possible reason for the lack of studies in this area might be that the eye tracking methodology used in the context of conventional radiography cannot be applied one-on-one to volumetric imaging material. Challenges associated with eye tracking in volumetric imaging are particularly associated with the selection of stimulus material, the detection of events in the eye tracking data, the calculation of meaningful eye tracking parameters, and the reporting of abnormalities. However, all of these challenges can be addressed in the design of the experiment. If this is done, eye tracking studies using volumetric imaging material offer almost unlimited opportunity for perception research and are highly relevant as the number of volumetric images that are acquired and interpreted is rising.

  14. Chromosome doubling method

    Science.gov (United States)

    Kato, Akio

    2006-11-14

    The invention provides methods for chromosome doubling in plants. The technique overcomes the low yields of doubled progeny associated with the use of prior techniques for doubling chromosomes in plants such as grasses. The technique can be used in large scale applications and has been demonstrated to be highly effective in maize. Following treatment in accordance with the invention, plants remain amenable to self fertilization, thereby allowing the efficient isolation of doubled progeny plants.

  15. Generating precipitation with the help of other meteorological variables

    Science.gov (United States)

    Schlabing, Dirk; Bárdossy, András

    2014-05-01

    Weather generators traditionally model dry and wet conditions separately. This necessitates not only the existence of a rain occurrence model, but also the double parametrisation of the process generating non-precipitation variables for dry and wet conditions. We propose a method to generate rain together with other meteorological variables within a single stochastic model, thus greatly reducing the number of needed parameters. Drier conditions can, to a certain extend, be seen by the values of non-precipitation variables becoming more distant to their mean values during wet conditions. Hence, this information can be used to estimate a probability of dryness. This probability is derived from values of air temperature, long and short wave radiation, relative humidity and wind speed components at every time step. Then, a continuous time series of precipitation is constructed in the standard-normal domain, comprised of the probability of dryness and transformed precipitation amounts. This time series can then be modelled with a single stochastic model such as a simple vector-autoregressive process. The generated time series is compared with measured data concerning their marginals, auto- and cross correlations as well as low-frequency variability.

  16. Particle precipitation in connection with KOH etching of silicon

    DEFF Research Database (Denmark)

    Nielsen, Christian Bergenstof; Christensen, Carsten; Pedersen, Casper

    2004-01-01

    This paper considers the precipitation of iron oxide particles in connection with the KOH etching of cavities in silicon wafers. The findings presented in this paper suggest that the source to the particles is the KOH pellets used for making the etching solution. Experiments show that the precipi...... of the change in free energy of adsorption, the Pourbaix diagram, the electrochemical double- layer thickness and silicon dopant type, and concentration. (C) 2004 The Electrochemical Society.......This paper considers the precipitation of iron oxide particles in connection with the KOH etching of cavities in silicon wafers. The findings presented in this paper suggest that the source to the particles is the KOH pellets used for making the etching solution. Experiments show...... that the precipitation is independent of KOH etching time, but that the amount of deposited material varies with dopant type and dopant concentration. The experiments also suggest that the precipitation occurs when the silicon wafers are removed from the KOH etching solution and not during the etching procedure. When...

  17. Planning strategies in volumetric modulated are therapy for breast.

    Science.gov (United States)

    Giorgia, Nicolini; Antonella, Fogliata; Alessandro, Clivio; Eugenio, Vanetti; Luca, Cozzi

    2011-07-01

    In breast radiotherapy with intensity modulation, it is a well established practice to extend the dose fluence outside the limit of the body contour to account for small changes in size and position of the target and the rest of the tissues due to respiration or to possible oedema. A simple approach is not applicable with RapidArc volumetric modulated are therapy not being based on a fixed field fluence delivery. In this study, a viable technical strategy to account for this need is presented. RapidArc (RA) plans for six breast cancer patients (three right and three left cases), were optimized (PRO version III) on the original CT data set (0) and on an alternative CT (E) generated with an artificial expansion (and assignment of soft-tissue equivalent HU) of 10 mm of the body in the breast region and of the PTV contours toward the external direction. Final dose calculations for the two set of plans were performed on the same original CT data set O, normalizing the dose prescription (50 Gy) to the target mean. In this way, two treatment plans on the same CT set O for each patient were obtained: the no action plan (OO) and the alternative plan based on an expanded optimization (EO). Fixing MU, these two plans were then recomputed on the expanded CT data set and on an intermediate one (with expansion = 5 mm), to mimic, possible changes in size due to edema during treatment or residual displacements due to breathing not properly controlled. Aim of the study was to quantify the robustness of this planning strategy on dose distributions when either the OO or the EO strategies were adopted. For all the combinations, a DVH analysis of all involved structures is reported. I. The two optimization approaches gave comparable dose distributions on the original CT data set. II. When plans were evaluated on the expanded CTs (mimicking the presence of edema), the EO approach showed improved target coverage if compared to OO: on CT_10 mm, Dv = 98% [%]= 92.5 +/- 0.9 and 68.5 +/- 3

  18. Planning strategies in volumetric modulated arc therapy for breast.

    Science.gov (United States)

    Nicolini, Giorgia; Fogliata, Antonella; Clivio, Alessandro; Vanetti, Eugenio; Cozzi, Luca

    2011-07-01

    In breast radiotherapy with intensity modulation, it is a well established practice to extend the dose fluence outside the limit of the body contour to account for small changes in size and position of the target and the rest of the tissues due to respiration or to possible oedema. A simple approach is not applicable with RapidArc volumetric modulated arc therapy not being based on a fixed field fluence delivery. In this study, a viable technical strategy to account for this need is presented. RapidArc (RA) plans for six breast cancer patients (three right and three left cases), were optimized (PRO version III) on the original CT data set (O) and on an alternative CT (E) generated with an artificial expansion (and assignment of soft-tissue equivalent HU) of 10 mm of the body in the breast region and of the PTV contours toward the external direction. Final dose calculations for the two set of plans were performed on the same original CT data set O, normalizing the dose prescription (50 Gy) to the target mean. In this way, two treatment plans on the same CT set O for each patient were obtained: the no action plan (OO) and the alternative plan based on an expanded optimization (EO). Fixing MU, these two plans were then recomputed on the expanded CT data set and on an intermediate one (with expansion = 5 mm), to mimic, possible changes in size due to edema during treatment or residual displacements due to breathing not properly controlled. Aim of the study was to quantify the robustness of this planning strategy on dose distributions when either the OO or the EO strategies were adopted. For all the combinations, a DVH analysis of all involved structures is reported. I. The two optimization approaches gave comparable dose distributions on the original CT data set. II. When plans were evaluated on the expanded CTs (mimicking the presence of edema), the EO approach showed improved target coverage if compared to OO: on CT_10 mm, DV = 98% [%] = 92.5 ± 0

  19. Volumetric Properties of the Mixture Tetrachloromethane CCl4 + CHCl3 Trichloromethane (VMSD1212, LB4576_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume C 'Binary Liquid Systems of Nonelectrolytes III' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Tetrachloromethane CCl4 + CHCl3 Trichloromethane (VMSD1212, LB4576_V)' providing data by calculation of molar excess volume from low-pressure density measurements at variable mole fraction and constant temperature.

  20. Determination of ferrous iron in rock and mineral samples by three volumetric methods

    OpenAIRE

    Saikkonen, R.J.; Rautiainen, I.A.

    1993-01-01

    Ferrous iron was determined by three volumetric methods in 13 in-house reference rock samples and in 31 international geological reference samples. The methods used were Amonette & Scott' s oxidimetric method, Wilson's oxidimetric method and Pratt's method. The results for FeO by these volumetric methods in 13 in-house rock samples were compared to the results obtained in other analytical laboratories in Finland. The results for FeO in the international samples were compared with published da...

  1. FEMUR SHAPE RECOVERY FROM VOLUMETRIC IMAGES USING 3-D DEFORMABLE MODELS

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A new scheme for femur shape recovery from volumetric images using deformable models was proposed. First, prior 3-D deformable femur models are created as templates using point distribution models technology. Second, active contour models are employed to segment the magnetic resonance imaging (MRI) volumetric images of the tibial and femoral joints and the deformable models are initialized based on the segmentation results. Finally, the objective function is minimized to give the optimal results constraining the surface of shapes.

  2. Understanding Volumetric and Gravimetric Hydrogen Adsorption Trade-off in Metal-Organic Frameworks.

    Science.gov (United States)

    Gómez-Gualdrón, Diego A; Wang, Timothy C; García-Holley, Paula; Sawelewa, Ruth M; Argueta, Edwin; Snurr, Randall Q; Hupp, Joseph T; Yildirim, Taner; Farha, Omar K

    2017-04-07

    Metal-organic frameworks (MOFs) are porous crystalline materials that are promising for adsorption-based, on-board storage of hydrogen in fuel-cell vehicles. Volumetric and gravimetric hydrogen capacities are the key factors that determine the size and weight of the MOF-filled tank required to store a certain amount of hydrogen for reasonable driving range. Therefore, they must be optimized so the tank is neither too large nor too heavy. Because the goals of maximizing MOF volumetric and gravimetric hydrogen adsorption loadings individually are incompatible, an in-depth understanding of the trade-off between MOF volumetric and gravimetric loadings is necessary to achieve the best compromise between these properties. Here we study, both experimentally and computationally, the trade-off between volumetric and gravimetric cryo-adsorbed hydrogen deliverable capacity by taking an isoreticular series of highly stable zirconium MOFs, NU-1101, NU-1102, and NU-1103 as a case study. These MOFs were studied under recently proposed operating conditions: 77 K/100 bar →160 K/5 bar. We found the difference between highest and lowest measured deliverable capacity in the MOF series to be ca. 40% gravimetrically, but only ca. 10% volumetrically. From our molecular simulation results, we found hydrogen "monolayer" adsorption to be proportional to the surface area, whereas hydrogen "pore filling" adsorption is proportional to the pore volume. Thus, we found that the higher variability in gravimetric deliverable capacity in contrast to the volumetric capacity, occurs due to the proportional relation between gravimetric surface area and pore volume in the NU-110x series in contrast to the inverse relation between volumetric surface area and void fraction. Additionally, we find better correlations with geometric surface areas than with BET areas. NU-1101 presents the highest measured volumetric performance with 46.6 g/L (9.1 wt %), whereas NU-1103 presents the highest gravimetric one

  3. How often precipitation records break?

    Science.gov (United States)

    Papalexiou, Simon Michael; Oikonomou, Maria; Floutsakou, Athina; Bessas, Nikolaos; Mamassis, Nikos

    2016-04-01

    How often precipitation records break? Are there any factors that determine the average time needed for the next maximum to occur? In order to investigate these simple questions we use several hundreds of daily precipitation records (more than 100 years long each) and we study the time intervals between each successive maximum precipitation value. We investigate if the record breaking time interval is related (a) to the autocorrelation structure, (b) to probability dry, and (c) to the tail of the marginal distribution. For the last, we first, evaluate which type of tail is better fitted by choosing among three general types of tails corresponding to the distributions Pareto, Lognormal and Weibull; and second, we assess the heaviness of the tail based on the estimated shape parameter. The performance of each tail is evaluated in terms of return period values, i.e., we compare the empirical return periods of precipitation values above a threshold with the predicted ones by each of the three types of fitted tails.

  4. Experimental study of brushite precipitation

    Science.gov (United States)

    Arifuzzaman, S. M.; Rohani, S.

    2004-07-01

    A systematic approach was developed for the synthesis of orthophosphates in the laboratory. A set of experiments was designed to investigate the influence of initial calcium and phosphorus concentration on the precipitated phase, nucleation pH and product size distribution at 25°C. Another goal was to characterize the precipitated phase. The investigation was conducted in a batch reactor. The initial molar concentration of calcium chloride and hydrated sodium phosphate solutions was varied from 0.005 to 0.08-mole dm -3 and the solution pH was kept under 7.1. Analysis by powder XRD, FTIR and elemental P/Ca revealed that the crystals precipitated were pure brushite (dicalcium phosphate dihydrate), as expected, except in one experiment in which amorphous calcium phosphate precipitated. The brushite crystals produced had plate-like morphology as investigated by scanning electron microscopy (SEM). The nucleation pH showed a decreasing trend as the concentration of the calcium and phosphorus increased in the reactor, but the volume mean diameter of the crystals and the span of the crystal size distribution did not show any sensitivity to the changes in the initial calcium and phosphorus concentration.

  5. Electrostatic Precipitator (ESP) TRAINING MANUAL

    Science.gov (United States)

    The manual assists engineers in using a computer program, the ESPVI 4.0W, that models all elements of an electrostatic precipitator (ESP). The program is a product of the Electric Power Research Institute and runs in the Windows environment. Once an ESP is accurately modeled, the...

  6. Grassland responses to precipitation extremes

    Science.gov (United States)

    Grassland ecosystems are naturally subjected to periods of prolonged drought and sequences of wet years. Climate change is expected to enhance the magnitude and frequency of extreme events at the intraannual and multiyear scales. Are grassland responses to extreme precipitation simply a response to ...

  7. Optimization of volumetric breast density estimation in digital mammograms.

    Science.gov (United States)

    Holland, Katharina; Gubern-Mérida, Albert; Mann, Ritse M; Karssemeijer, Nico

    2017-05-07

    Fibroglandular tissue volume and percent density can be estimated in unprocessed mammograms using a physics-based method, which relies on an internal reference value representing the projection of fat only. However, pixels representing fat only may not be present in dense breasts, causing an underestimation of density measurements. In this work, we investigate alternative approaches for obtaining a tissue reference value to improve density estimations, particularly in dense breasts. Two of three investigated reference values (F1, F2) are percentiles of the pixel value distribution in the breast interior (the contact area of breast and compression paddle). F1 is determined in a small breast interior, which minimizes the risk that peripheral pixels are included in the measurement at the cost of increasing the chance that no proper reference can be found. F2 is obtained using a larger breast interior. The new approach which is developed for very dense breasts does not require the presence of a fatty tissue region. As reference region we select the densest region in the mammogram and assume that this represents a projection of entirely dense tissue embedded between the subcutaneous fatty tissue layers. By measuring the thickness of the fat layers a reference (F3) can be computed. To obtain accurate breast density estimates irrespective of breast composition we investigated a combination of the results of the three reference values. We collected 202 pairs of MRI's and digital mammograms from 119 women. We compared the percent dense volume estimates based on both modalities and calculated Pearson's correlation coefficients. With the references F1-F3 we found respectively a correlation of [Formula: see text], [Formula: see text] and [Formula: see text]. Best results were obtained with the combination of the density estimations ([Formula: see text]). Results show that better volumetric density estimates can be obtained with the hybrid method, in particular for dense

  8. Semiautomatic segmentation of liver metastases on volumetric CT images

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Jiayong [Department of Biomedical Engineering, Shanghai University of Medicine & Health Sciences, 101 Yingkou Road, Yang Pu District, Shanghai 200093 (China); Schwartz, Lawrence H.; Zhao, Binsheng, E-mail: bz2166@cumc.columbia.edu [Department of Radiology, Columbia University Medical Center, 630 West 168th Street, New York, New York 10032 (United States)

    2015-11-15

    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

  9. Blockwise conjugate gradient methods for image reconstruction in volumetric CT.

    Science.gov (United States)

    Qiu, W; Titley-Peloquin, D; Soleimani, M

    2012-11-01

    Cone beam computed tomography (CBCT) enables volumetric image reconstruction from 2D projection data and plays an important role in image guided radiation therapy (IGRT). Filtered back projection is still the most frequently used algorithm in applications. The algorithm discretizes the scanning process (forward projection) into a system of linear equations, which must then be solved to recover images from measured projection data. The conjugate gradients (CG) algorithm and its variants can be used to solve (possibly regularized) linear systems of equations Ax=b and linear least squares problems minx∥b-Ax∥2, especially when the matrix A is very large and sparse. Their applications can be found in a general CT context, but in tomography problems (e.g. CBCT reconstruction) they have not widely been used. Hence, CBCT reconstruction using the CG-type algorithm LSQR was implemented and studied in this paper. In CBCT reconstruction, the main computational challenge is that the matrix A usually is very large, and storing it in full requires an amount of memory well beyond the reach of commodity computers. Because of these memory capacity constraints, only a small fraction of the weighting matrix A is typically used, leading to a poor reconstruction. In this paper, to overcome this difficulty, the matrix A is partitioned and stored blockwise, and blockwise matrix-vector multiplications are implemented within LSQR. This implementation allows us to use the full weighting matrix A for CBCT reconstruction without further enhancing computer standards. Tikhonov regularization can also be implemented in this fashion, and can produce significant improvement in the reconstructed images.

  10. Application of AAPM TG 119 to volumetric arc therapy (VMAT).

    Science.gov (United States)

    Mynampati, Dinesh Kumar; Yaparpalvi, Ravindra; Hong, Linda; Kuo, Hsiang-Chi; Mah, Dennis

    2012-09-06

    The purpose of this study was to create AAPM TG 119 benchmark plans for volumetric arc therapy (VMAT) and to compare VMAT plans with IMRT plan data. AAPM TG 119 proposes a set of test clinical cases for testing the accuracy of IMRT planning and delivery system. For these test cases, we generated two treatment plans, the first plan using 7-9 static dMLC IMRT fields and a second plan utilizing one- or two-arc VMAT technique. Dose optimization and calculations performed using 6 MV photons and Eclipse treatment planning system. Dose prescription and planning objectives were set according to the TG 119 goals. Plans were scored based on TG 119 planning objectives. Treatment plans were compared using conformity index (CI) for reference dose and homogeneity index (HI) (for D(5)-D(95)). For test cases prostate, head-and-neck, C-shape and multitarget prescription dose are 75.6 Gy, 50.4 Gy, 50 Gy and 50 Gy, respectively. VMAT dose distributions were comparable to dMLC IMRT plans. Our planning results matched TG 119 planning results. For treatment plans studied, conformity indices ranged from 1.05-1.23 (IMRT) and 1.04-1.23 (VMAT). Homogeneity indices ranged from 4.6%-11.0% (IMRT) and 4.6%-10.5% (VMAT). The ratio of total monitor units necessary for dMLC IMRT to that of VMAT was in the range of 1.1-2.0. AAPM TG 119 test cases are useful to generate VMAT benchmark plans. At preclinical implementation stage, plan comparison of VMAT and IMRT plans of AAPM TG 119 test case allowed us to understand basic capabilities of VMAT technique.

  11. Mammographic density estimation with automated volumetric breast density measurement.

    Science.gov (United States)

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

    2014-01-01

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

  12. Trends in Precipitation Extremes over Southeast Asia

    Science.gov (United States)

    Endo, N.; Matsumoto, J.

    2010-12-01

    Trends in precipitation extremes were examined using daily precipitation data from Southeast Asian countries during 1950's to 2000's. Number of wet day, defined by a day with daily precipitation exceeding 1 mm, tends to decrease over these countries, while average precipitation intensity of wet day shows an increasing trend. Heavy precipitation indices, which are defined by precipitation amount and percentile, demonstrate that the number of stations with significant upward trend is larger than that with significant downward trend. Heavy precipitation increases in southern Vietnam, northern part of Myanmar, and the Visayas and Luzon Islands in the Philippines, while heavy precipitation decreases in northern Vietnam. Annual maximum number of consecutive dry days decreases in the region where winter monsoon precipitation dominates. Prolongation of the dry season is suggested in Myanmar.

  13. Effects of precipitation changes on aboveground net primary production and soil respiration in a switchgrass field

    Science.gov (United States)

    This study attempted to test whether switchgrass aboveground net primary production (ANPP) responds to precipitation (PPT) changes in a double asymmetry pattern as framed by Knapp et al. (2016), and whether it is held true for other ecosystem processes such as soil respiration (SR). Data were colle...

  14. Correlation between total precipitable water and precipitation over East Asia

    Science.gov (United States)

    Keum, Wangho; Lim, Gyu-Ho

    2017-04-01

    The precipitation rate(PR) and the total precipitable water(TPW) interact with various physical mechanisms. The correlation of two variables changes with difference of domain resolution and characteristics of the region. This poster analyzes the correlation between PR and TPW over East Asia using Cyclostationary Empirical Orthogonal Function(CSEOF) which is one of the PCA analysis. The CSEOF is useful to search a periodic pattern of the data. The anomalies which is subtracted climatological mean from the original data are used to represent annual cycles. Two variances of ERA-Interim Monthly Total Column Water vapor and GPCP monthly precipitation amounts with 372 time since January, 1984 to December, 2014 are decomposed into several modes separately. The first mode which explain largest variance are used in analysis. PC of both PR and TPW increase recently on mean value and amplitude, and they show considerable correlation on phase. The correlation coefficient of PR and TPW is 0.61 and maintains the same values by month. The result of harmonic analysis shows 2 to 6 year oscillations. As result of decomposed modes of two variables, there is the relationship between TPW PC series and horizontal moisture gradient. The Horizontal moist gradient can change affect moisture flux convergence which is one of important variable of rainfall events.

  15. Niobium carbide precipitation in microalloyed steel

    Energy Technology Data Exchange (ETDEWEB)

    Klinkenberg, C.; Hulka, K. [Niobium Products Co. GmbH, Duesseldorf (Germany); Bleck, W. [Inst. for Ferrous Metallurgy, RWTH Aachen Univ., Aachen (Germany)

    2004-11-01

    The precipitation of niobium carbo-nitrides in the austenite phase, interphase and ferrite phase of microalloyed steel was assessed by a critical literature review and a round table discussion. This work analyses the contribution of niobium carbide precipitates formed in ferrite in the precipitation hardening of commercially hot rolled strip. Thermodynamics and kinetics of niobium carbo-nitride precipitation as well as the effect of deformation and temperature on the precipitation kinetics are discussed in various examples to determine the amount of niobium in solid solution that will be available for precipitation hardening after thermomechanical rolling in the austenite phase and successive phase transformation. (orig.)

  16. Enhanced oil recovery by surfactant-enhanced volumetric sweep efficiency: First annual report for the period September 30, 1985-September 30, 1986. [Sandpacks

    Energy Technology Data Exchange (ETDEWEB)

    Harwell, J H; Scamehorn, J F

    1987-05-01

    Surfactant-enhanced volumetric sweep efficiency is a novel EOR method which utilizes precipitation/coacervation of surfactants to plug the most permeable regions of the reservoir, improving the efficiency of a waterflooding operation. This technique does not rely on reduction of interfacial tension between aqueous and oleic phases to enhance oil recovery. Therefore, even though surfactants are involved, this new technique is not a substitute or improvement on classical surfactant flooding; however, it has the potantial to compete with polymer flooding as an alternative sweep efficiency improvement method. In surfactant-enhanced volumetric sweep efficiency, a slug containing one kind of surfactant is injected into the reservoir, followed by a brine spacer. This is followed by injection of a second kind of surfactant which has lower adsorption than the first surfactant used. Anionic and cationic surfactants are one possible combination for this application. These may form either a precipitate or a coacervate upon mixing. Phase boundaries for some specific systems of this type have been determined over a wide range of conditions and a model developed to describe this behavior. Another possibility is the use of nonionic surfactants, which may form coacervate under proper conditions. The adsorption behavior of mixtures of anionic and nonionic surfactants was measured to aid in modeling the chromatographic effects with these surfactants in the reservoir. Studies with sandpacks of different permeabilities in parallel configuration using mixtures of anionic and cationic surfactants have demonstrated the capability of this method to reduce flow rates through a more permeable sandpack more than that through a less permeable sandpack. 4 refs., 23 figs., 8 tabs.

  17. A Technique for Generating Volumetric Cine MRI (VC-MRI)

    Science.gov (United States)

    Harris, Wendy; Ren, Lei; Cai, Jing; Zhang, You; Chang, Zheng; Yin, Fang-Fang

    2016-01-01

    Purpose To develop a technique to generate on-board volumetric-cine MRI (VC-MRI) using patient prior images, motion modeling and on-board 2D-cine MRI. Methods One phase of a 4D-MRI acquired during patient simulation is used as patient prior images. 3 major respiratory deformation patterns of the patient are extracted from 4D-MRI based on principal-component-analysis. The on-board VC-MRI at any instant is considered as a deformation of the prior MRI. The deformation field is represented as a linear combination of the 3 major deformation patterns. The coefficients of the deformation patterns are solved by the data fidelity constraint using the acquired on-board single 2D-cine MRI. The method was evaluated using both XCAT simulation of lung cancer patients and MRI data from four real liver cancer patients. The accuracy of the estimated VC-MRI was quantitatively evaluated using Volume-Percent-Difference(VPD), Center-of-Mass-Shift(COMS), and target tracking errors. Effects of acquisition orientation, region-of-interest(ROI) selection, patient breathing pattern change and noise on the estimation accuracy were also evaluated. Results Image subtraction of ground-truth with estimated on-board VC-MRI shows fewer differences than image subtraction of ground-truth with prior image. Agreement between profiles in the estimated and ground-truth VC-MRI was achieved with less than 6% error for both XCAT and patient data. Among all XCAT scenarios, the VPD between ground-truth and estimated lesion volumes was on average 8.43±1.52% and the COMS was on average 0.93±0.58mm across all time-steps for estimation based on the ROI region in the sagittal cine images. Matching to ROI in the sagittal view achieved better accuracy when there was substantial breathing pattern change. The technique was robust against noise levels up to SNR=20. For patient data, average tracking errors were less than 2 mm in all directions for all patients. Conclusions Preliminary studies demonstrated the

  18. A Technique for Generating Volumetric Cine-Magnetic Resonance Imaging.

    Science.gov (United States)

    Harris, Wendy; Ren, Lei; Cai, Jing; Zhang, You; Chang, Zheng; Yin, Fang-Fang

    2016-06-01

    The purpose of this study was to develop a techique to generate on-board volumetric cine-magnetic resonance imaging (VC-MRI) using patient prior images, motion modeling, and on-board 2-dimensional cine MRI. One phase of a 4-dimensional MRI acquired during patient simulation is used as patient prior images. Three major respiratory deformation patterns of the patient are extracted from 4-dimensional MRI based on principal-component analysis. The on-board VC-MRI at any instant is considered as a deformation of the prior MRI. The deformation field is represented as a linear combination of the 3 major deformation patterns. The coefficients of the deformation patterns are solved by the data fidelity constraint using the acquired on-board single 2-dimensional cine MRI. The method was evaluated using both digital extended-cardiac torso (XCAT) simulation of lung cancer patients and MRI data from 4 real liver cancer patients. The accuracy of the estimated VC-MRI was quantitatively evaluated using volume-percent-difference (VPD), center-of-mass-shift (COMS), and target tracking errors. Effects of acquisition orientation, region-of-interest (ROI) selection, patient breathing pattern change, and noise on the estimation accuracy were also evaluated. Image subtraction of ground-truth with estimated on-board VC-MRI shows fewer differences than image subtraction of ground-truth with prior image. Agreement between normalized profiles in the estimated and ground-truth VC-MRI was achieved with less than 6% error for both XCAT and patient data. Among all XCAT scenarios, the VPD between ground-truth and estimated lesion volumes was, on average, 8.43 ± 1.52% and the COMS was, on average, 0.93 ± 0.58 mm across all time steps for estimation based on the ROI region in the sagittal cine images. Matching to ROI in the sagittal view achieved better accuracy when there was substantial breathing pattern change. The technique was robust against noise levels up to SNR = 20. For

  19. Volumetric particle image velocimetry with a single plenoptic camera

    Science.gov (United States)

    Fahringer, Timothy W.; Lynch, Kyle P.; Thurow, Brian S.

    2015-11-01

    A novel three-dimensional (3D), three-component (3C) particle image velocimetry (PIV) technique based on volume illumination and light field imaging with a single plenoptic camera is described. A plenoptic camera uses a densely packed microlens array mounted near a high resolution image sensor to sample the spatial and angular distribution of light collected by the camera. The multiplicative algebraic reconstruction technique (MART) computed tomography algorithm is used to reconstruct a volumetric intensity field from individual snapshots and a cross-correlation algorithm is used to estimate the velocity field from a pair of reconstructed particle volumes. This work provides an introduction to the basic concepts of light field imaging with a plenoptic camera and describes the unique implementation of MART in the context of plenoptic image data for 3D/3C PIV measurements. Simulations of a plenoptic camera using geometric optics are used to generate synthetic plenoptic particle images, which are subsequently used to estimate the quality of particle volume reconstructions at various particle number densities. 3D reconstructions using this method produce reconstructed particles that are elongated by a factor of approximately 4 along the optical axis of the camera. A simulated 3D Gaussian vortex is used to test the capability of single camera plenoptic PIV to produce a 3D/3C vector field, where it was found that lateral displacements could be measured to approximately 0.2 voxel accuracy in the lateral direction and 1 voxel in the depth direction over a 300× 200× 200 voxel volume. The feasibility of the technique is demonstrated experimentally using a home-built plenoptic camera based on a 16-megapixel interline CCD camera and a 289× 193 array of microlenses and a pulsed Nd:YAG laser. 3D/3C measurements were performed in the wake of a low Reynolds number circular cylinder and compared with measurements made using a conventional 2D/2C PIV system. Overall, single camera

  20. Transient refractory material dissolution by a volumetrically-heated melt

    Energy Technology Data Exchange (ETDEWEB)

    Seiler, Jean Marie, E-mail: jean-marie.seiler@cea.fr [CEA, DEN, DTN, 17 Rue des Martyrs, 38054 Grenoble Cedex 9 (France); Ratel, Gilles [CEA, DEN, DTN, 17 Rue des Martyrs, 38054 Grenoble Cedex 9 (France); Combeau, Hervé [Institut Jean Lamour, UMR 7198, Lorraine University, Ecole des Mines de Nancy, Parc de Saurupt, 54042 Nancy Cedex (France); Gaus-Liu, Xiaoyang; Kretzschmar, Frank; Miassoedov, Alexei [Karlsruhe Institut of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany)

    2014-12-15

    Highlights: • We describe a test investigating ceramic dissolution by a molten non-eutectic melt. • The evolution of the interface temperature between melt and refractory is measured. • A theoretical model describing dissolution kinetics is proposed. • When dissolution stops, interface temperature is the liquidus temperature of the melt. - Abstract: The present work addresses the question of corium–ceramic interaction in a core catcher during a core-melt accident in a nuclear power plant. It provides an original insight into transient aspects concerning dissolution of refractory material by a volumetrically heated pool. An experiment with simulant material (LIVECERAM) is presented. Test results clearly show that dissolution of solid refractory material can occur in a non-eutectic melt at a temperature which is lower than the melting temperature of the refractory material. During the dissolution transient, the interface temperature rises above the liquidus temperature, corresponding to the instantaneous average composition of the melt pool. With constant power dissipation in the melt and external cooling of the core-catcher, a final steady-state situation is reached. Dissolution stops when the heat flux (delivered by the melt to the refractory) can be removed by conduction through the residual thickness of the ceramic, with T{sub interface} = T{sub liquidus} (calculated for the average composition of the final liquid pool). The final steady state corresponds to a uniform pool composition and uniform interface temperature distribution. Convection in the pool is governed by natural thermal convection and the heat flux distribution is therefore similar to what would be obtained for a single component pool. An interpretation of the experiment with two model-based approaches (0D and 1D) is presented. The mass transfer kinetics between the interface and the bulk is controlled by a diffusion sublayer within the boundary layer. During the dissolution transient

  1. Volumetric Forest Change Detection Through Vhr Satellite Imagery

    Science.gov (United States)

    Akca, Devrim; Stylianidis, Efstratios; Smagas, Konstantinos; Hofer, Martin; Poli, Daniela; Gruen, Armin; Sanchez Martin, Victor; Altan, Orhan; Walli, Andreas; Jimeno, Elisa; Garcia, Alejandro

    2016-06-01

    Quick and economical ways of detecting of planimetric and volumetric changes of forest areas are in high demand. A research platform, called FORSAT (A satellite processing platform for high resolution forest assessment), was developed for the extraction of 3D geometric information from VHR (very-high resolution) imagery from satellite optical sensors and automatic change detection. This 3D forest information solution was developed during a Eurostars project. FORSAT includes two main units. The first one is dedicated to the geometric and radiometric processing of satellite optical imagery and 2D/3D information extraction. This includes: image radiometric pre-processing, image and ground point measurement, improvement of geometric sensor orientation, quasiepipolar image generation for stereo measurements, digital surface model (DSM) extraction by using a precise and robust image matching approach specially designed for VHR satellite imagery, generation of orthoimages, and 3D measurements in single images using mono-plotting and in stereo images as well as triplets. FORSAT supports most of the VHR optically imagery commonly used for civil applications: IKONOS, OrbView - 3, SPOT - 5 HRS, SPOT - 5 HRG, QuickBird, GeoEye-1, WorldView-1/2, Pléiades 1A/1B, SPOT 6/7, and sensors of similar type to be expected in the future. The second unit of FORSAT is dedicated to 3D surface comparison for change detection. It allows users to import digital elevation models (DEMs), align them using an advanced 3D surface matching approach and calculate the 3D differences and volume changes between epochs. To this end our 3D surface matching method LS3D is being used. FORSAT is a single source and flexible forest information solution with a very competitive price/quality ratio, allowing expert and non-expert remote sensing users to monitor forests in three and four dimensions from VHR optical imagery for many forest information needs. The capacity and benefits of FORSAT have been tested in

  2. Improving plan quality for prostate volumetric-modulated arc therapy.

    Science.gov (United States)

    Wright, Katrina; Ferrari-Anderson, Janet; Barry, Tamara; Bernard, Anne; Brown, Elizabeth; Lehman, Margot; Pryor, David

    2017-08-04

    We critically evaluated the quality and consistency of volumetric-modulated arc therapy (VMAT) prostate planning at a single institution to quantify objective measures for plan quality and establish clear guidelines for plan evaluation and quality assurance. A retrospective analysis was conducted on 34 plans generated on the Pinnacle(3) version 9.4 and 9.8 treatment planning system to deliver 78 Gy in 39 fractions to the prostate only using VMAT. Data were collected on contoured structure volumes, overlaps and expansions, planning target volume (PTV) and organs at risk volumes and relationship, dose volume histogram, plan conformity, plan homogeneity, low-dose wash, and beam parameters. Standard descriptive statistics were used to describe the data. Despite a standardized planning protocol, we found variability was present in all steps of the planning process. Deviations from protocol contours by radiation oncologists and radiation therapists occurred in 12% and 50% of cases, respectively, and the number of optimization parameters ranged from 12 to 27 (median 17). This contributed to conflicts within the optimization process reflected by the mean composite objective value of 0.07 (range 0.01 to 0.44). Methods used to control low-intermediate dose wash were inconsistent. At the PTV rectum interface, the dose-gradient distance from the 74.1 Gy to 40 Gy isodose ranged from 0.6 cm to 2.0 cm (median 1.0 cm). Increasing collimator angle was associated with a decrease in monitor units and a single full 6 MV arc was sufficient for the majority of plans. A significant relationship was found between clinical target volume-rectum distance and rectal tolerances achieved. A linear relationship was determined between the PTV volume and volume of 40 Gy isodose. Objective values and composite objective values were useful in determining plan quality. Anatomic geometry and overlap of structures has a measurable impact on the plan quality achieved for prostate patients

  3. Acid precipitation; an annotated bibliography

    Science.gov (United States)

    Wiltshire, Denise A.; Evans, Margaret L.

    1984-01-01

    This collection of 1660 bibliographies references on the causes and environmental effects of acidic atmospheric deposition was compiled from computerized literature searches of earth-science and chemistry data bases. Categories of information are (1) atmospheric chemistry (gases and aerosols), (2) precipitation chemistry, (3) transport and deposition (wet and dry), (4) aquatic environments (biological and hydrological), (5) terrestrial environments, (6) effects on materials and structures, (7) air and precipitation monitoring and data collection, and (8) modeling studies. References date from the late 1800 's through December 1981. The bibliography includes short summaries of most documents. Omitted are unpublished manuscripts, publications in press, master 's theses and doctoral dissertations, newspaper articles, and book reviews. Coauthors and subject indexes are included. (USGS)

  4. Effect of the precipitation interpolation method on the performance of a snowmelt runoff model

    Science.gov (United States)

    Jacquin, Alexandra

    2014-05-01

    , HBV parameters are calibrated with respect to Nash-Sutcliffe efficiency. The performance of HBV in the study catchment is not satisfactory. Although volumetric errors are modest, efficiency values are lower than 70%. Discharge estimates resulting from the application of TP, MFF and IDW obtain similar model efficiencies and volumetric errors. These error statistics moderately improve if KED or OIM are used instead. Even though the quality of precipitation estimates of distinct interpolation methods is dissimilar, the results of this study show that these differences do not necessarily produce noticeable changes in HBV's model performance statistics. This situation arises because the calibration of the model parameters allows some degree of compensation of deficient areal precipitation estimates, mainly through the adjustment of model simulated evaporation and glacier melt, as revealed by the analysis of water balances. In general, even if there is a good agreement between model estimated and observed discharge, this information is not sufficient to assert that the internal hydrological processes of the catchment are properly simulated by a watershed model. Other calibration criteria should be incorporated if a more reliable representation of these processes is desired. Acknowledgements: This research was funded by FONDECYT, Research Project 1110279. The HBV Light software used in this study was kindly provided by J. Seibert, Department of Geography, University of Zürich.

  5. Precipitation patterns during channel flow

    Science.gov (United States)

    Jamtveit, B.; Hawkins, C.; Benning, L. G.; Meier, D.; Hammer, O.; Angheluta, L.

    2013-12-01

    Mineral precipitation during channelized fluid flow is widespread in a wide variety of geological systems. It is also a common and costly phenomenon in many industrial processes that involve fluid flow in pipelines. It is often referred to as scale formation and encountered in a large number of industries, including paper production, chemical manufacturing, cement operations, food processing, as well as non-renewable (i.e. oil and gas) and renewable (i.e. geothermal) energy production. We have studied the incipient stages of growth of amorphous silica on steel plates emplaced into the central areas of the ca. 1 meter in diameter sized pipelines used at the hydrothermal power plant at Hellisheidi, Iceland (with a capacity of ca 300 MW electricity and 100 MW hot water). Silica precipitation takes place over a period of ca. 2 months at approximately 120°C and a flow rate around 1 m/s. The growth produces asymmetric ca. 1mm high dendritic structures ';leaning' towards the incoming fluid flow. A novel phase-field model combined with the lattice Boltzmann method is introduced to study how the growth morphologies vary under different hydrodynamic conditions, including non-laminar systems with turbulent mixing. The model accurately predicts the observed morphologies and is directly relevant for understanding the more general problem of precipitation influenced by turbulent mixing during flow in channels with rough walls and even for porous flow. Reference: Hawkins, C., Angheluta, L., Hammer, Ø., and Jamtveit, B., Precipitation dendrites in channel flow. Europhysics Letters, 102, 54001

  6. Global Precipitation Mission Visualization Tool

    Science.gov (United States)

    Schwaller, Mathew

    2011-01-01

    The Global Precipitation Mission (GPM) software provides graphic visualization tools that enable easy comparison of ground- and space-based radar observations. It was initially designed to compare ground radar reflectivity from operational, ground-based, S- and C-band meteorological radars with comparable measurements from the Tropical Rainfall Measuring Mission (TRMM) satellite's precipitation radar instrument. This design is also applicable to other groundbased and space-based radars, and allows both ground- and space-based radar data to be compared for validation purposes. The tool creates an operational system that routinely performs several steps. It ingests satellite radar data (precipitation radar data from TRMM) and groundbased meteorological radar data from a number of sources. Principally, the ground radar data comes from national networks of weather radars (see figure). The data ingested by the visualization tool must conform to the data formats used in GPM Validation Network Geometry-matched data product generation. The software also performs match-ups of the radar volume data for the ground- and space-based data, as well as statistical and graphical analysis (including two-dimensional graphical displays) on the match-up data. The visualization tool software is written in IDL, and can be operated either in the IDL development environment or as a stand-alone executable function.

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

    Science.gov (United States)

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

    2011-12-01

    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. Fifty artificial lymph nodes were produced in a size range from 10 to 55mm; 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. 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. 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 ≤3mm and a medium soft reconstruction kernel (e.g. B40f for Siemens scan systems) may be a suitable compromise for semi-automated volumetric analysis. Copyright

  8. Recovery of small DNA fragments from serum using compaction precipitation.

    Directory of Open Access Journals (Sweden)

    Binh V Vu

    Full Text Available BACKGROUND: While most nucleic acids are intracellular, trace amounts of deoxyribonucleic acid (DNA and ribonucleic acid (RNA, including micro RNAs, can also be found in peripheral blood. Many studies have suggested the potential utility of these circulating nucleic acids in prenatal diagnosis, early cancer detection, and the diagnosis of infectious diseases. However, DNA circulating in blood is usually present at very low concentrations (ng/ml, and is in the form of relatively small fragments (<1,000 bp, making its isolation challenging. METHODS: Here we report an improved method for the isolation of small DNA fragments from serum using selective precipitation by quaternary ammonium compaction agents. A 151 bp fragment of double-stranded DNA from the Escherichia coli bacteriophage lambda served as the model DNA in our experiments. DNA was serially diluted in serum until undetectable by conventional polymerase chain reaction (PCR, before being enriched by compaction precipitation. RESULTS: Starting with concentrations two to three orders of magnitude lower than the PCR-detectable level (0.01 ng/ml, we were able to enrich the DNA to a detectable level using a novel compaction precipitation protocol. The isolated DNA product after compaction precipitation was largely free of serum contaminants and was suitable for downstream applications. CONCLUSIONS: Using compaction precipitation, we were able to isolate and concentrate small DNA from serum, and increase the sensitivity of detection by more than four orders of magnitude. We were able to recover and detect very low levels (0.01 ng/ml of a small DNA fragment in serum. In addition to being very sensitive, the method is fast, simple, inexpensive, and avoids the use of toxic chemicals.

  9. Performance Assessment of Multi-Source Weighted-Ensemble Precipitation (MSWEP Product over India

    Directory of Open Access Journals (Sweden)

    Akhilesh S. Nair

    2017-01-01

    Full Text Available Error characterization is vital for the advancement of precipitation algorithms, the evaluation of numerical model outputs, and their integration in various hydro-meteorological applications. The Tropical Rainfall Measuring Mission (TRMM Multi-satellite Precipitation Analysis (TMPA has been a benchmark for successive Global Precipitation Measurement (GPM based products. This has given way to the evolution of many multi-satellite precipitation products. This study evaluates the performance of the newly released multi-satellite Multi-Source Weighted-Ensemble Precipitation (MSWEP product, whose temporal variability was determined based on several data products including TMPA 3B42 RT. The evaluation was conducted over India with respect to the IMD-gauge-based rainfall for pre-monsoon, monsoon, and post monsoon seasons at daily scale for a 35-year (1979–2013 period. The rainfall climatology is examined over India and over four geographical extents within India known to be subject to uniform rainfall. The performance evaluation of rainfall time series was carried out. In addition to this, the performance of the product over different rainfall classes was evaluated along with the contribution of each class to the total rainfall. Further, seasonal evaluation of the MSWEP products was based on the categorical and volumetric indices from the contingency table. Upon evaluation it was observed that the MSWEP products show large errors in detecting the higher quantiles of rainfall (>75th and > 95th quantiles. The MSWEP precipitation product available at a 0.25° × 0.25° spatial resolution and daily temporal resolution matched well with the daily IMD rainfall over India. Overall results suggest that a suitable region and season-dependent bias correction is essential before its integration in hydrological applications. While the MSWEP was observed to perform well for daily rainfall, it suffered from poor detection capabilities for higher quantiles, making

  10. European climate change experiments on precipitation change

    DEFF Research Database (Denmark)

    Beier, Claus

    Presentation of European activities and networks related to experiments and databases within precipitation change......Presentation of European activities and networks related to experiments and databases within precipitation change...

  11. Seasonal precipitation forecast skill over Iran

    CSIR Research Space (South Africa)

    Shirvani, A

    2015-07-01

    Full Text Available of the Global Precipitation Climatology Centre (GPCC) Version 6 gridded precipitation data, using model output statistics (MOS) developed through the canonical correlation analysis (CCA) option of the Climate Predictability Tool (CPT). Retroactive validations...

  12. River Forecasting Center Quantitative Precipitation Estimate Archive

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Radar indicated-rain gage verified and corrected hourly precipitation estimate on a corrected ~4km HRAP grid. This archive contains hourly estimates of precipitation...

  13. U.S. 15 Minute Precipitation Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — U.S. 15 Minute Precipitation Data is digital data set DSI-3260, archived at the National Climatic Data Center (NCDC). This is precipitation data. The primary source...

  14. Nickel hydroxide precipitation from aqueous sulfate media

    Science.gov (United States)

    Sist, Cinziana; Demopoulos, George P.

    2003-08-01

    Hydrometallurgical processing of laterite ores constitutes a major industrial and R&D activity in extractive metallurgy. In some of the process flowsheets, nickel hydroxide precipitation is incorporated. For these operations, the optimization of nickel hydroxide precipitation is important to assure efficiency and product quality. The main objective of this investigation was to study and improve the precipitation characteristics of Ni(OH)2 in a sulfate system using supersaturation controlled precipitation.

  15. Unintegrated double parton distributions

    CERN Document Server

    Golec-Biernat, K

    2016-01-01

    We present the construction of unintegrated double parton distribution functions which include dependence on transverse momenta of partons. We extend the formulation which was used to obtain the single unintegrated parton distributions from the standard, integrated parton distribution functions. Starting from the homogeneous part of the evolution equations for the integrated double parton distributions, we construct the unintegrated double parton distributions as the convolutions of the integrated double distributions and the splitting functions, multiplied by the Sudakov form factors. We show that there exist three domains of external hard scales which require three distinct forms of the unintegrated double distributions. The additional transverse momentum dependence which arises through the Sudakov form factors leads to non-trivial correlations in the parton momenta. We also discuss the non-homogeneous contribution to the unintegrated double parton distributions, which arises due to the splitting of a singl...

  16. Global Precipitation Measurement (GPM) Mission: NASA Precipitation Processing System (PPS)

    Science.gov (United States)

    Stocker, Erich Franz

    2008-01-01

    NASA is contributing the precipitation measurement data system PPS to support the GPM mission. PPS will distribute all GPM data products including NASA s GMI data products freely and quickly. PPS is implementing no system mechanisms for restricting access to GPM data. PPS is implementing no system mechanisms for charging for GPM data products. PPS will provide a number of geographical and parameter subsetting features available to its users. The first implementation of PPS (called PPS--) will assume processing of TRMM data effective 1 June 2008. TRMM realtime data will be available via PPS- to all users requesting access

  17. On Double Vector Bundles

    Institute of Scientific and Technical Information of China (English)

    Zhuo CHEN; Zhang Ju LIU; Yun He SHENG

    2014-01-01

    In this paper, we construct a category of short exact sequences of vector bundles and prove that it is equivalent to the category of double vector bundles. Moreover, operations on double vector bundles can be transferred to operations on the corresponding short exact sequences. In particular, we study the duality theory of double vector bundles in term of the corresponding short exact sequences. Examples including the jet bundle and the Atiyah algebroid are discussed.

  18. On Double Vector Bundles

    OpenAIRE

    Chen, Zhuo; Liu, Zhangju; Sheng, Yunhe

    2011-01-01

    In this paper, we construct a category of short exact sequences of vector bundles and prove that it is equivalent to the category of double vector bundles. Moreover, operations on double vector bundles can be transferred to operations on the corresponding short exact sequences. In particular, we study the duality theory of double vector bundles in term of the corresponding short exact sequences. Examples including the jet bundle and the Atiyah algebroid are discussed.

  19. UNILATERAL INCOMPLETE DOUBLE URETER

    Directory of Open Access Journals (Sweden)

    Kaini

    2013-04-01

    Full Text Available ABSTRACT: Double ureter is a result of premature division of t he ureteric bud. The ureters may join in the lower third of their course and open thr ough a common orifice into the bladder. If they open independently into the bladder, the ureter draining the upper pelvis opens into the bladder below the opening of the other ureter. Patie nts with double ureter or double pelvis are more likely to develop urinary infection and calculi .

  20. The effects of dimensional mould sizes on volumetric shrinkage strain of lateritic soil

    Directory of Open Access Journals (Sweden)

    John Engbonye SANI

    2016-07-01

    Full Text Available Dimensional influences of specimen size on the volumetric shrinkage strain values of a lateritic soil for waste containment system have not been researched upon. Therefore, this paper presents the result of a laboratory study on the volumetric shrinkage strain (VSS of lateritic soil at three different dimensional sizes of mould (split former mould, proctor mould and California bearing ratio mould at three energy levels; British standard light (BSL, West African standard (WAS and British standard heavy (BSH respectively. Compactions were done at different molding water content of -2% to +6% optimum moisture content (OMC. At -2% to +2% molding water content for the split former mould the volumetric shrinkage strain met the requirement of not more than 4% while at +4% and +6% only the WAS and BSH met the requirement. The proctor mould and the CBR mould on the other hand gave a lower value of volumetric shrinkage strain in all compactive effort and the values are lower than the 4% safe VSS suggested by Tay et al., (2001. Based on the VSS values obtained if the CBR mould can be used to model site condition it is recommended for use to simulate site condition for Volumetric shrinkage strain for all molding water content and compactive effort.

  1. Semi-automated volumetric analysis of lymph node metastases during follow-up--initial results.

    Science.gov (United States)

    Fabel, Michael; Bolte, H; von Tengg-Kobligk, H; Bornemann, L; Dicken, V; Delorme, S; Kauczor, H-U; Heller, M; Biederer, J

    2011-04-01

    Quantification of tumour burden in oncology requires accurate and reproducible evaluation. The current standard is RECIST measurement with its inherent disadvantages. Volumetric analysis is an alternative for therapy monitoring. The aim of this study was to evaluate the feasibility of volumetric analysis of lymph node metastases using a software prototype in a follow-up setting. MSCT was performed in 50 patients covering the chest, abdomen and pelvis. A total of 174 suspicious lymph nodes were evaluated by two radiologists regarding short axis diameters and volumetric analysis using semi-automated software. Quality of segmentation, time, maximum diameter and volume were documented. Variability of the derived change rates was computed as the standard deviation of the difference of the obtained respective change rates. The software performance provides robust volumetric analysis. Quality of segmentation was rated acceptable to excellent in 76-79% by each reader. Mean time spent per lesion was 38 s. The variability of change in effective diameters was 10.6%; for change rates of RECIST maximum diameter variability was 27.5%. Semi-automated volumetric analysis allows fast and convenient segmentation of most lymph node metastases. Compared with RECIST the inter-observer-variability in baseline and follow-up is reduced. This should principally allow subtle changes to be subclassified within the RECIST stable range as minor response [-15% to +10%].

  2. Observing Double Stars

    Science.gov (United States)

    Genet, Russell M.; Fulton, B. J.; Bianco, Federica B.; Martinez, John; Baxter, John; Brewer, Mark; Carro, Joseph; Collins, Sarah; Estrada, Chris; Johnson, Jolyon; Salam, Akash; Wallen, Vera; Warren, Naomi; Smith, Thomas C.; Armstrong, James D.; McGaughey, Steve; Pye, John; Mohanan, Kakkala; Church, Rebecca

    2012-05-01

    Double stars have been systematically observed since William Herschel initiated his program in 1779. In 1803 he reported that, to his surprise, many of the systems he had been observing for a quarter century were gravitationally bound binary stars. In 1830 the first binary orbital solution was obtained, leading eventually to the determination of stellar masses. Double star observations have been a prolific field, with observations and discoveries - often made by students and amateurs - routinely published in a number of specialized journals such as the Journal of Double Star Observations. All published double star observations from Herschel's to the present have been incorporated in the Washington Double Star Catalog. In addition to reviewing the history of visual double stars, we discuss four observational technologies and illustrate these with our own observational results from both California and Hawaii on telescopes ranging from small SCTs to the 2-meter Faulkes Telescope North on Haleakala. Two of these technologies are visual observations aimed primarily at published "hands-on" student science education, and CCD observations of both bright and very faint doubles. The other two are recent technologies that have launched a double star renaissance. These are lucky imaging and speckle interferometry, both of which can use electron-multiplying CCD cameras to allow short (30 ms or less) exposures that are read out at high speed with very low noise. Analysis of thousands of high speed exposures allows normal seeing limitations to be overcome so very close doubles can be accurately measured.

  3. Electron microscopy studies of the age-hardening behaviors in 6005A alloy and microstructural characterizations of precipitates

    Energy Technology Data Exchange (ETDEWEB)

    Yang Wenchao, E-mail: wenchaoyang@csu.edu.cn [EPSRC Centre for Innovative Manufacturing in Liquid Metal Engineering, Brunel Centre for Advanced Solidification Technology (BCAST), Brunel University, Uxbridge, Middlesex UB8 3PH (United Kingdom); School of Materials Science and Engineering, Central South University, Changsha 410083 (China); Huang Lanping [State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083 (China); Zhang Ruirong [School of Chemistry and Chemical Engineering, Central South University, Changsha 410083 (China); Wang Mingpu; Li Zhou; Jia Yanlin; Lei Ruoshan; Sheng Xiaofei [School of Materials Science and Engineering, Central South University, Changsha 410083 (China)

    2012-02-15

    Highlights: Black-Right-Pointing-Pointer TEM and HREM are used to elucidate an anti overaged softening behavior in Al-0.65Mg-0.73Si-0.13Cu alloy. Black-Right-Pointing-Pointer The {beta} Double-Prime precipitate not only has a 2-dimensions coherency strain-field, but also has the smaller size and a high density. Black-Right-Pointing-Pointer The strengthening of three main precipitates on alloy can be summarized as: {beta} Double-Prime > Q Prime > {beta} Prime . Black-Right-Pointing-Pointer The {beta} Double-Prime , {beta} Prime and Q Prime precipitates have 12 orientation variants with Al matrix, respectively. Black-Right-Pointing-Pointer Moire fringes are used to verify the lattice parameters and orientation variants of precipitates. - Abstract: High-resolution electron microscopy was used to research the age-hardening behaviors in 6005A alloy and the microstructural characterizations of precipitates. It was found that {beta} Double-Prime , {beta} Prime and Q Prime precipitates had 12 orientation variants, respectively, the smaller size and a high-density {beta} Prime Prime precipitates existed in alloy for a long time, which played a very important role in controlling an anti-overaged softening behavior in 6005A alloy. Further, by the crystallographic interface and morphology analysis, a main reason was that a 2-dimensions coherency strain-field not only had the high-density {beta} Prime Prime precipitates become the biggest obstacle of dislocations movement, but also made them transform into {beta} Prime and Q Prime precipitates with more difficulty. Moreover, it was also found that {beta} Prime and Q Prime precipitates had weaker relatively strain-fields, the larger size and a lower density, which were largely associated with the reduction in hardness that occurred upon overaging. Further, the strengthening of precipitates on alloys could be summarized as: {beta} Double-Prime > Q Prime > {beta} Prime . Based on the structural information, the quantitative Moire

  4. Springtime precipitation effects on the abundance of fluorescent biological aerosol particles and HULIS in Beijing

    Science.gov (United States)

    Yue, Siyao; Ren, Hong; Fan, Songyun; Sun, Yele; Wang, Zifa; Fu, Pingqing

    2016-07-01

    Bioaerosols and humic-like substances (HULIS) are important components of atmospheric aerosols, which can affect regional climate by acting as cloud condensation nuclei and some of which can damage human health. Up to date, release of bioaerosols and HULIS initiated by precipitation is still poorly understood. Here we present different release processes for bioaerosols, non-bioaerosols and HULIS during a precipitation event in Beijing, China. Large fungal-spore-like aerosols were emitted at the onset and later weak stage of precipitation, the number concentration of which increased by more than two folds, while the number concentration of bacteria-like particles doubled when the precipitation strengthened. Besides, a good correlation between protein-like substances that were measured simultaneously by on-line and off-line fluorescence techniques consolidated their applications to measure bioaerosols. Furthermore, our EEM results suggest that the relative contribution of water-soluble HULIS to microbial materials was enhanced gradually by the rain event.

  5. A volumetric meter chip for point-of-care quantitative detection of bovine catalase for food safety control.

    Science.gov (United States)

    Cui, Xingye; Hu, Jie; Choi, Jane Ru; Huang, Yalin; Wang, Xuemin; Lu, Tian Jian; Xu, Feng

    2016-09-07

    A volumetric meter chip was developed for quantitative point-of-care (POC) analysis of bovine catalase, a bioindicator of bovine mastitis, in milk samples. The meter chip displays multiplexed quantitative results by presenting the distance of ink bar advancement that is detectable by the naked eye. The meter chip comprises a poly(methyl methacrylate) (PMMA) layer, a double-sided adhesive (DSA) layer and a glass slide layer fabricated by the laser-etching method, which is typically simple, rapid (∼3 min per chip), and cost effective (∼$0.2 per chip). Specially designed "U shape" reaction cells are covered by an adhesive tape that serves as an on-off switch, enabling the simple operation of the assay. As a proof of concept, we employed the developed meter chip for the quantification of bovine catalase in raw milk samples to detect catalase concentrations as low as 20 μg/mL. The meter chip has great potential to detect various target analytes for a wide range of POC applications.

  6. Volumetric-modulated arc therapy for oropharyngeal carcinoma: a dosimetric and delivery efficiency comparison with static-field IMRT.

    Science.gov (United States)

    Dai, Xiaofang; Zhao, Yingchao; Liang, Zhiwen; Dassarath, Meera; Wang, Lu; Jin, Lihui; Chen, Lili; Dong, James; Price, Robert A; Ma, C-M

    2015-02-01

    The purpose of this study is to evaluate the treatment plan adequacy and delivery efficiency among volumetric-modulated arc therapy (VMAT) with one or two arcs and the conventional static-field dynamic multileaf collimator (dMLC) intensity-modulated radiation therapy (IMRT) in patients undergoing oropharyngeal carcinoma. Fifteen patient cases were included in this investigation. Each of the cases was planned using step-and-shoot IMRT, VMAT with a single arc (Arc1) and VMAT with double arcs (Arc2). A two-dose level prescription for planning target volumes (PTVs) was delivered with 70 Gy/56 Gy in 30 fractions. Comparisons were performed of the dose-volume histograms (DVH) for PTVs, the DVH for organs at risk (OARs), the monitor units per fraction (MU/fx), and delivery time. IMRT and Arc2 achieved similar target coverage, but superior to Arc1. Apart from the oral cavity, Arc1 showed no advantage in sparing of OARs compared with IMRT, while Arc2 obtained equivalent or better sparing of OARs among the three techniques. VMAT reduced MU/fx and shortened delivery time remarkably compared with IMRT. Our results demonstrated that for oropharyngeal cases, Arc2 can achieve superior target coverage and normal tissue sparing, as well as a significant reduction in treatment time. Copyright © 2014 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  7. Corrosion Resistance of the Superhydrophobic Mg(OH)2/Mg-Al Layered Double Hydroxide Coatings on Magnesium Alloys

    National Research Council Canada - National Science Library

    Zhang, Fen; Zhang, Changlei; Zeng, Rongchang; Song, Liang; Guo, Lian; Huang, Xiaowen

    2016-01-01

      Coatings of the Mg(OH)2/Mg-Al layered double hydroxide (LDH) composite were formed by a combined co-precipitation method and hydrothermal process on the AZ31 alloy substrate in alkaline condition...

  8. Skill assessment of precipitation nowcasting in Mediterranean Heavy Precipitation Events

    Science.gov (United States)

    Bech, Joan; Berenguer, Marc

    2013-04-01

    Very short-term precipitation forecasting (i.e nowcasting) systems may provide valuable support in the weather surveillance process as they allow to issue automated early warnings for heavy precipitation events (HPE) as reviewed recently by Pierce et al. (2012). The need for warnings is essential in densely populated regions of small catchments, such as those typically found in Mediterranean coastal areas, prone to flash-floods. Several HPEs that occurred in NE Spain are analyzed using a nowcasting system based on the extrapolation of rainfall fields observed with weather radar following a Lagrangian approach developed and tested successfully in previous studies (Berenguer et al. 2005, 2011). Radar-based nowcasts, with lead times up to 3 h, are verified here against quality-controlled weather radar quantitative precipitation estimates and also against a dense network of raingauges. The basic questions studied are the dependence of forecast quality with lead time and rainfall amounts in several high-impact HPEs such as the 7 September 2005 Llobregat Delta river tornado outbreak (Bech et al. 2007) or the 2 November 2008 supercell tornadic thunderstorms (Bech et al. 2011) - both cases had intense rainfall rates (30' amounts exceeding 38.2 and 12.3 mm respectively) and daily values above 100 mm. Verification scores indicated that forecasts of 30' precipitation amounts provided useful guidance for lead times up to 60' for moderate intensities (up to 1 mm in 30') and up to 2.5h for lower rates (above 0.1 mm). On the other hand correlations of radar estimates and forecasts exceeded Eulerian persistence of precipitation estimates for lead times of 1.5 h for moderate intensities (up to 0.8 mm/h). We complete the analysis with a discussion on the reliability of threshold to lead time dependence based on the event-to-event variability found. This work has been done in the framework of the ProFEWS project (CGL2010-15892). References Bech J, N Pineda, T Rigo, M Aran, J Amaro, M

  9. Limnological aspects of acid precipitation

    Energy Technology Data Exchange (ETDEWEB)

    Hendrey, G.R. (ed.)

    1978-01-01

    Lakes and streams in parts of Norway, Sweden, Canada, and the United States are being severely impacted by acidic precipitation. Scientists meeting at Sagamore, New York, agreed that this is the most serious limnological problem today. The factor responsible for determining the sensitivity of surface waters to acidification is alkalinity derived by weathering of soils and bedrock in the watershed. Acidification, defined as a reduction in alkalinity, can be quantified if preacidification alkalinity data exist, but often they do not. Data on pH and Ca from surface waters in areas not affected by acid precipitation were compared to similar data from areas which receive precipitation with a weighted average hydrogen ion concentration of pH < 4.6. A semiquantitative estimation of surface water acidification can be made for lakes and streams, where earlier chemistry data are lacking, based on this analysis of pH and Ca data. Biological responses to acidification range from a reduction in numbers of species of algae and zooplankton to complete elimination of all fish life. Major biological processes such as primary production and decomposition may be altered leading to an accumulation of plant material and organic debris within lakes and streams. Increased concentrations of aluminum from the ..mu..g/l to mg/l range have been found at levels shown to be toxic to fish. These elevated levels apparently result from the exchange of H/sup +/ and Al in the watershed. There also appears to be a relationship between lake acidification and the accumulation of mercury in fish. Problems of aluminum analysis received detailed attention, and watershed mass balances, comparative watershed studies, whole lake manipulations, synoptic surveys, and the liming of acidified waters were discussed. A priority-rated list of recommendations for research was presented.

  10. Struvite Precipitation and Biological Dissolutions.

    OpenAIRE

    Ezquerro, Ander

    2010-01-01

    Struvite is a salt that is formed out of  Mg2+,NH4+ and PO43- and it crystallizes in form of MgNH4PO4.6H2O. Struvite‟s (magnesium ammonium phosphate or MAP) precipitation has recently been regarded as an interesting technique to remove phosphate and ammonium from waste water. The high elimination rates and the possibility of recycling the struvite as a direct slow release fertilizer make this process feasible and appealing. However, the costs due to the raw chemicals needed are drawbacks that...

  11. Three-dimensional full-range complex Fourier domain optical coherence tomography for in-vivo volumetric imaging of human skin

    Science.gov (United States)

    Nan, Nan; Bu, Peng; Guo, Xin; Wang, Xiangzhao

    2012-03-01

    A three dimensional full-range complex Fourier domain optical coherence tomography (complex FDOCT) system based on sinusoidal phase-modulating method is proposed. With the system, the range of imaging depth is doubled and the sensitivity degradation with the lateral scan distance is avoided. Fourier analysis of B-scan data along lateral scan distance is used for reconstructing the complex spectral interferograms. The B-scan based Fourier method improves the system tolerance of sample movement and makes data processing less time consuming. In vivo volumetric imaging of human skin with the proposed full-range FDOCT system is demonstrated. The mirror image rejection ratio is about 30 dB. The stratum corneum, the epidermis and the upper dermis of skin can be clearly identified in the reconstructed three dimensional FDOCT images.

  12. VOLUMETRIC MASS TRANSFER COEFFICIENT BETWEEN SLAG AND METAL IN COMBINED BLOWING CONVERTER

    Institute of Scientific and Technical Information of China (English)

    Z.H. Wu; Z.S. Zou; W. Wu

    2005-01-01

    The effects of operation parameters of combined blowing converter on the volumetric mass transfer coefficient between slag and steel are studied with a cold model with water simulating steel, oil simulating slag and benzoic acid as the transferred substance between water and oil. The results show that, with lance level of 2.Im and the top blowing rate of 25000Nm3/h, the volumetric mass transfer coefficient changes most significantly when the bottom blowing rate ranges from 384 to 540Nm3/h. The volumetric mass transfer coefficient reaches its maximum when the lance level is 2. lm, the top blowing rates is 30000Nm3/h, and the bottom blowing rate is 384Nrr3/h with tuyeres located symmetrically at 0.66D of the converter bottom.

  13. Control and design of volumetric composition in pultruded hybrid fibre composites

    DEFF Research Database (Denmark)

    Madsen, Bo; Hashemi, Fariborz; Tahir, Paridah

    2016-01-01

    Hybrid composites consist of two of more fibre phases in a common matrix phase. This is a challenge for the control and design of the volumetric composition and microstructural uniformity of such composites. In the present study, a model is presented for the prediction of the complete volumetric...... 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....

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

    Energy Technology Data Exchange (ETDEWEB)

    Moran, Traci L.; Larche, Michael R.; Denslow, Kayte M.; Glass, Samuel W.

    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.

  15. 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.

  16. Single step full volumetric reconstruction optical coherence tomography utilizing compressive sensing

    Science.gov (United States)

    Chen, Luoyang; Liu, Jiansheng; cheng, Jiangtao; Liu, Haitao; Zhou, Hongwen

    2017-03-01

    3D optical coherence tomography imaging (OCT) combined with compressive sensing (CS) has been proved to be an attractive and effective tool in a variety of fields, such as medicine and biology. To achieve high quality imaging while using as less CS sampling rate as possible is the goal of this approach. Here we present an innovative single step fully 3D CS-OCT volumetric image recovery method, in which 3D OCT volumetric image of the object is compressively sampled via our proposed CS coding strategies in all three dimensions while its sparsity is simultaneously taken into consideration in every direction. The object can be directly recovered as the whole volume reconstruction via our advanced full 3D CS reconstruction algorithm. The numerical simulations of a human retina OCT volumetric image reconstruction by our method demonstrate a PSNR of as high as 38dB at a sampling rate of less than 10%.

  17. Seeding optimization for instantaneous volumetric velocimetry. Application to a jet in crossflow

    CERN Document Server

    Cambonie, Tristan

    2014-01-01

    Every volumetric velocimetry measurements based on tracer (particles, bubbles, etc.) detection can be strongly influenced by the optical screening phenomenon. It has to be taken into account when the the statistical properties associated to the performances of the particle detection and tracking algorithms are significantly affected. It leads to a maximum concentration of particles in the images thus limiting the final spatial resolution of the instantaneous three-dimensional three-components (3D3C) velocity fields. A volumetric velocimetry system based on Defocused Digital Particle Image Velocimetry is used to show that above a critical visual concentration of particles in the images, the concentration and accuracy of the final instantaneous raw velocity vector field drop. The critical concentration depends on physical parameters as well as on the processing algorithms. Three distinct regimes are identified. In the first regime, the concentration is well adapted to volumetric velocimetry, the largest concent...

  18. The nonstationary impact of local temperature changes and ENSO on extreme precipitation at the global scale

    Science.gov (United States)

    Sun, Qiaohong; Miao, Chiyuan; Qiao, Yuanyuan; Duan, Qingyun

    2017-02-01

    The El Niño-Southern Oscillation (ENSO) and local temperature are important drivers of extreme precipitation. Understanding the impact of ENSO and temperature on the risk of extreme precipitation over global land will provide a foundation for risk assessment and climate-adaptive design of infrastructure in a changing climate. In this study, nonstationary generalized extreme value distributions were used to model extreme precipitation over global land for the period 1979-2015, with ENSO indicator and temperature as covariates. Risk factors were estimated to quantify the contrast between the influence of different ENSO phases and temperature. The results show that extreme precipitation is dominated by ENSO over 22% of global land and by temperature over 26% of global land. With a warming climate, the risk of high-intensity daily extreme precipitation increases at high latitudes but decreases in tropical regions. For ENSO, large parts of North America, southern South America, and southeastern and northeastern China are shown to suffer greater risk in El Niño years, with more than double the chance of intense extreme precipitation in El Niño years compared with La Niña years. Moreover, regions with more intense precipitation are more sensitive to ENSO. Global climate models were used to investigate the changing relationship between extreme precipitation and the covariates. The risk of extreme, high-intensity precipitation increases across high latitudes of the Northern Hemisphere but decreases in middle and lower latitudes under a warming climate scenario, and will likely trigger increases in severe flooding and droughts across the globe. However, there is some uncertainties associated with the influence of ENSO on predictions of future extreme precipitation, with the spatial extent and risk varying among the different models.

  19. The Contribution of Extreme Precipitation to the Total Precipitation in China

    Institute of Scientific and Technical Information of China (English)

    SUN Jian-Qi

    2012-01-01

    Using daily precipitation data from weather stations in China, the variations in the contribution of extreme precipitation to the total precipitation are analyzed. It is found that extreme precipitation accounts for approximately one third of the total precipitation based on the overall mean for China. Over the past half century, extreme precipitation has played a dominant role in the year-to-year variability of the total precipitation. On the decadal time scale, the extreme precipitation makes different contributions to the wetting and drying regions of China. The wetting trends of particular regions are mainly attributed to increases in extreme precipitation; in contrast, the drying trends of other regions are mainly due to decreases in non-extreme precipitation.

  20. Heavy precipitation episodes and cosmic rays variation

    Directory of Open Access Journals (Sweden)

    A. Mavrakis

    2006-01-01

    Full Text Available In this paper an attempt is made to investigate the possible temporal correlation between heavy precipitation episodes and cosmic rays' activity, on various time scales. Cosmic rays measurements are sparse and cover less extended periods than those of precipitation. Precipitation is largely influenced by local climatic and even physiographic conditions, while cosmic rays' distribution is far more uniform over an area. Thus, in an effort to cover a larger range of climatic characteristics, each cosmic rays station was correlated with several nearby precipitation stations. Selected statistical methods were employed for the data processing. The analysis was preformed on annual, seasonal, monthly and daily basis whenever possible. Wet and dry regions and/or seasons seem to present a different response of precipitation to cosmic rays variations. Also Forbush decreases in most cases will not lead to heavy precipitation, yet this might be sensitive to precipitable water availability.

  1. Estimating Tropical Cyclone Precipitation from Station Observations

    Institute of Scientific and Technical Information of China (English)

    REN Fumin; WANG Yongmei; WANG Xiaoling; LI Weijing

    2007-01-01

    In this paper, an objective technique for estimating the tropical cyclone (TC) precipitation from station observations is proposed. Based on a comparison between the Original Objective Method (OOM) and the Expert Subjective Method (ESM), the Objective Synoptic Analysis Technique (OSAT) for partitioning TC precipitation was developed by analyzing the western North Pacific (WNP) TC historical track and the daily precipitation datasets. Being an objective way of the ESM, OSAT overcomes the main problems in OOM,by changing two fixed parameters in OOM, the thresholds for the distance of the absolute TC precipitation (D0) and the TC size (D1), into variable parameters.Case verification for OSAT was also carried out by applying CMORPH (Climate Prediction Center MORPHing technique) daily precipitation measurements, which is NOAA's combined satellite precipitation measurement system. This indicates that OSAT is capable of distinguishing simultaneous TC precipitation rain-belts from those associated with different TCs or with middle-latitude weather systems.

  2. Advanced patterning solutions based on double exposure: double patterning and beyond

    Science.gov (United States)

    Bae, Young C.; Liu, Yi; Cardolaccia, Thomas; Spizuoco, Ken; Bell, Rosemary; Joesten, Lori; Pikon, Amandine; Reilly, Michael; Ablaza, Sheri; Trefonas, Peter; Barclay, George G.

    2009-12-01

    The CD control of the first lithography (L1) patterns is a important issue in the single-etch double patterning (SEDP) process. In this process, L1 patterns are cured either chemically or thermally and then subjected to the second lithography (L2). A chemical curing process using a surface curing agent (SCA) often results in the CD growth due to the "positive" interaction between the first and second resists. A thermal curing process using a thermal cure resist (TCR) often results in the CD loss due to the volumetric shrinkage of the L1 patterns during the L2 process. By combining SCA and TCR concepts, we developed a simple "hybrid" curing system which offers precise control of the L1 CD after double patterning. This hybrid curing system involves thermal curing followed by a liquid rinse process using a double patterning primer (DPP). DPP is an aqueous solution formulated with SCA components and enhances "positive" interaction between L1 and L2 patterns. While CD loss of 5~6nm is observed without DPP treatment, ~11nm CD growth was observed with TCR after DPP treatment. The L1 CD after double patterning was precisely controllable by post-priming bake process with the rate of -0.3nm/°C in the temperature ranging from 120 ~ 150°C. Taking advantage of the CD growth with DPP treatment, we further developed three different advanced patterning schemes: 1. "Shrink Process Assisted by Double Exposure" (SPADE I), 2. "Space Patterning Assisted by Double Exposure" (SPADE II), and 3. "Sidewall Patterning Assisted by Double Exposure" (SPADE III). Using SPADE I, contact hole CD was reduced by 10~30nm and excellent through pitch performance was observed. SPADE I can also improve LER/LWR when used in the formation of smaller trenches. SPADE II was developed for self-aligned pitch splitting of contact holes and SPADE III was developed for self-aligned pitch splitting of lines. In this paper, the use of DPP in various SPADE technologies is described and its potential in the

  3. Long-term trend and variability of precipitation in Chhattisgarh State, India

    Science.gov (United States)

    Meshram, Sarita Gajbhiye; Singh, Vijay P.; Meshram, Chandrashekhar

    2017-08-01

    Spatial and temporal precipitation variability in Chhattisgarh State in India was examined by using monthly precipitation data for 102 years (1901-2002) from 16 stations. The homogeneity of precipitation data was evaluated by the double-mass curve approach and the presence of serial correlation by lag-1 autocorrelation coefficient. Linear regression analysis, the conventional Mann-Kendall (MK) test, and Spearman's rho were employed to identify trends and Sen's slope to estimate the slope of trend line. The coefficient of variation (CV) was used to analyze precipitation variability. Spatial interpolation was done by a Kriging process using ArcGIS 9.3. Results of both parametric and non-parametric tests and trend tests showed that at 5 % significance level, annual precipitation exhibited a decreasing trend at all stations except Bilaspur and Dantewada. For both annual and monsoon precipitation, Sen's test showed a decreasing trend for all stations, except Bilaspur and Dantewada. The highest percentage of variability was observed in winter precipitation (88.75 %) and minimum percentage variability in annual series (14.01 %) over the 102-year periods.

  4. Long-term trend and variability of precipitation in Chhattisgarh State, India

    Science.gov (United States)

    Meshram, Sarita Gajbhiye; Singh, Vijay P.; Meshram, Chandrashekhar

    2016-04-01

    Spatial and temporal precipitation variability in Chhattisgarh State in India was examined by using monthly precipitation data for 102 years (1901-2002) from 16 stations. The homogeneity of precipitation data was evaluated by the double-mass curve approach and the presence of serial correlation by lag-1 autocorrelation coefficient. Linear regression analysis, the conventional Mann-Kendall (MK) test, and Spearman's rho were employed to identify trends and Sen's slope to estimate the slope of trend line. The coefficient of variation (CV) was used to analyze precipitation variability. Spatial interpolation was done by a Kriging process using ArcGIS 9.3. Results of both parametric and non-parametric tests and trend tests showed that at 5 % significance level, annual precipitation exhibited a decreasing trend at all stations except Bilaspur and Dantewada. For both annual and monsoon precipitation, Sen's test showed a decreasing trend for all stations, except Bilaspur and Dantewada. The highest percentage of variability was observed in winter precipitation (88.75 %) and minimum percentage variability in annual series (14.01 %) over the 102-year periods.

  5. Double beta decay experiments

    CERN Document Server

    Barabash, A S

    2011-01-01

    The present status of double beta decay experiments is reviewed. The results of the most sensitive experiments are discussed. Proposals for future double beta decay experiments with a sensitivity to the $$ at the level of (0.01--0.1) eV are considered.

  6. Dual doubled geometry

    NARCIS (Netherlands)

    Bergshoeff, Eric A.; Riccioni, Fabio; Alvarez-Gaumé, L.

    2011-01-01

    We probe doubled geometry with dual fundamental branes. i.e. solitons. Restricting ourselves first to solitonic branes with more than two transverse directions we find that the doubled geometry requires an effective wrapping rule for the solitonic branes which is dual to the wrapping rule for fundam

  7. Volumetric Concentration Maximum of Cohesive Sediment in Waters: A Numerical Study

    Directory of Open Access Journals (Sweden)

    Jisun Byun

    2014-12-01

    Full Text Available Cohesive sediment has different characteristics compared to non-cohesive sediment. The density and size of a cohesive sediment aggregate (a so-called, floc continuously changes through the flocculation process. The variation of floc size and density can cause a change of volumetric concentration under the condition of constant mass concentration. This study investigates how the volumetric concentration is affected by different conditions such as flow velocity, water depth, and sediment suspension. A previously verified, one-dimensional vertical numerical model is utilized here. The flocculation process is also considered by floc in the growth type flocculation model. Idealized conditions are assumed in this study for the numerical experiments. The simulation results show that the volumetric concentration profile of cohesive sediment is different from the Rouse profile. The volumetric concentration decreases near the bed showing the elevated maximum in the cases of both current and oscillatory flow. The density and size of floc show the minimum and the maximum values near the elevation of volumetric concentration maximum, respectively. This study also shows that the flow velocity and the critical shear stress have significant effects on the elevated maximum of volumetric concentration. As mechanisms of the elevated maximum, the strong turbulence intensity and increased mass concentration are considered because they cause the enhanced flocculation process. This study uses numerical experiments. To the best of our knowledge, no laboratory or field experiments on the elevated maximum have been carried out until now. It is of great necessity to conduct well-controlled laboratory experiments in the near future.

  8. Precipitation chemistry in central Amazonia

    Science.gov (United States)

    Andreae, M. O.; Talbot, R. W.; Berresheim, H.; Beecher, K. M.

    1990-01-01

    Rain samples from three sites in central Amazonia were collected over a period of 6 weeks during the 1987 wet season and analyzed for ionic species and dissolved organic carbon. A continuous record of precipitation chemistry and amount was obtained at two of these sites, which were free from local or regional pollution, for a time period of over 1 month. The volume-weighted mean concentrations of most species were found to be about a factor of 5 lower during the wet season compared with previous results from the dry season. Only sodium, potassium, and chloride showed similar concentrations in both seasons. When the seasonal difference in rainfall amount is taken into consideration, the deposition fluxes are only slightly lower for most species during the wet season than during the dry season, again with the exception of chloride, potassium, and sodium. Sodium and chloride are present in the same ratio as in sea salt; rapid advection of air masses of marine origin to the central Amazon Basin during the wet season may be responsible for the observed higher deposition flux of these species. Statistical analysis suggests that sulfate is, to a large extent, of marine (sea salt and biogenic) origin, but that long-range transport of combustion-derived aerosols also makes a significant contribution to sulfate and nitrate levels in Amazonian rain. Organic acid concentrations in rain were responsible for a large fraction of the observed precipitation acidity; their concentration was strongly influenced by gas/liquid interactions.

  9. Using scaling fluctuation analysis to quantify anthropogenic changes in regional and global precipitation, including extremes

    Science.gov (United States)

    de Lima, Isabel; Lovejoy, Shaun

    2016-04-01

    Anthropic precipitation changes affect the mean and the magnitude and frequency of extreme events, and therefore potentially have severe consequences in all aspects of human life. Unfortunately, - unlike the anthropic temperature changes - precipitation changes of anthropic origin have been proven difficult to establish with high statistical significance. For example, when changes have been established for individual precipitation products, the serious divergences found between products reflect our limited ability to estimate areal precipitation even at global scales. In addition to data issues, the usual approaches to assessing changes in precipitation also have methodological issues that hamper their identification. Here we discuss how the situation can be clarified by the systematic application of scaling fluctuation analysis - for example, to determine the scales at which the anthropogenic signal exceeds the natural variability noise (we find that it is roughly 20 years). Following a recent approach for estimating anthropogenic temperature changes we directly determine the effective sensitivity of the precipitation rate to a doubling of CO2. The novelty in this approach is that it takes CO2 as a surrogate for all anthropogenic forcings and estimates the trend based on the forcing rather than time - the usual approach. This leads both to an improved signal to noise ratio and, when compared to the usual estimates of trends, it augments their statistical significance; we further improve the signal to noise ratio by considering precipitation over the ocean where anthropogenic increases are strongest, finding that there are statistically significant trends at the 3 to 4 standard deviation level. This approach also permits the first direct estimate of the increases in global precipitation with temperature: we find 1.71±0.62 %/K which is close to that found by GCM's (2 - 3%/K) and is well below the value of ≈ 6 - 7%/K predicted on the basis of increases in humidity

  10. Using pressure and volumetric approaches to estimate CO2 storage capacity in deep saline aquifers

    OpenAIRE

    Thibeau, S.; Bachu, S.; Birkholzer, J.; Holloway, S; Neele, F.P.; Zou, Q

    2014-01-01

    Various approaches are used to evaluate the capacity of saline aquifers to store CO2, resulting in a wide range of capacity estimates for a given aquifer. The two approaches most used are the volumetric “open aquifer” and “closed aquifer” approaches. We present four full-scale aquifer cases, where CO2 storage capacity is evaluated both volumetrically (with “open” and/or “closed” approaches) and through flow modeling. These examples show that the “open aquifer” CO2 storage capacity estimation ...

  11. Effects of volumetric allocation on heave response of semisubmersible in deep sea

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The configuration of semisubmersibles consisting of pontoons and columns and their corresponding heave motion response in incident progressive waves are examined. The purpose of the present study is to provide a theoretical approach to estimating the effects of volumetric allocation on natural period and response amplitude operator (RAO) in heave motion. We conclude that the amplitude of heave motion response can be considerably suppressed by appropriately adjusting volumetric allocation so that the natural heave period keeps away from the range of wave energy. The theoretical formulae are found in good agreement with the corresponding computational results by WAMIT.

  12. Volumetric Diffuse Optical Tomography for Small Animals Using a CCD-Camera-Based Imaging System

    Directory of Open Access Journals (Sweden)

    Zi-Jing Lin

    2012-01-01

    Full Text Available We report the feasibility of three-dimensional (3D volumetric diffuse optical tomography for small animal imaging by using a CCD-camera-based imaging system with a newly developed depth compensation algorithm (DCA. Our computer simulations and laboratory phantom studies have demonstrated that the combination of a CCD camera and DCA can significantly improve the accuracy in depth localization and lead to reconstruction of 3D volumetric images. This approach may present great interests for noninvasive 3D localization of an anomaly hidden in tissue, such as a tumor or a stroke lesion, for preclinical small animal models.

  13. DIRECT VOXEL-PROJECTION FOR VOLUMETRIC DATA RENDERING IN MEDICAL IMAGERY

    Institute of Scientific and Technical Information of China (English)

    吕忆松; 陈亚珠; 郭玉红

    2002-01-01

    The volumetric rendering of 3-D medical image data is very effective method for communication about radiological studies to clinicians. Algorithms that produce images with artifacts and inaccuracies are not clinically useful. This paper proposed a direct voxel-projection algorithm to implement volumetric data rendering. Using this algorithm, arbitrary volume rotation, transparent and cutaway views are generated satisfactorily. Compared with the existing raytracing methods, it improves the projection image quality greatly. Some experimental results about real medical CT image data demonstrate the advantages and fidelity of the proposed algorithm.

  14. Topological Quantum Double

    Science.gov (United States)

    Bonneau, Philippe

    Following a preceding paper showing how the introduction of a t.v.s. topology on quantum groups led to a remarkable unification and rigidification of the different definitions, we adapt here, in the same way, the definition of quantum double. This topological double is dualizable and reflexive (even for infinite dimensional algebras). In a simple case we show, considering the double as the "zero class" of an extension theory, the uniqueness of the double structure as a quasi-Hopf algebra. A la suite d'un précédent article montrant comment l'introduction d'une topologie d'e.v.t. sur les groupes quantiques permet une unification et une rigidification remarquables des différentes définitions, on adapte ici de la même manière la définition du double quantique. Ce double topologique est alors dualisable et reflexif (même pour des algèbres de dimension infinie). Dans un cas simple on montre, en considérant le double comme la "classe zéro" d'une théorie d'extensions, l'unicité de cette structure comme algèbre quasi-Hopf.

  15. Preliminary Study of Zinc Removal from Cyanide-free Alkaline Electroplating Effluent by Precipitation Using Oxalis Plants

    Directory of Open Access Journals (Sweden)

    Benouali D.

    2014-06-01

    Full Text Available The aim of this study is the reduction of Zinc from the cyanide-free alkaline zinc-platingeffluent. Various methods utilizedfor removing or recovering the heavy metals are adsorption, chemical precipitation, sedimentationfiltration, reverse osmosis etc. We are interested in using oxalisplant as a potential chelating/settling agent for the treatment of electroplatingeffluent collected from a local industrial unit.Oxalis pes-capaehas an exceptionally high content of oxalic acid which isknown as moderate and week chelating agent.Theefficiency of the performance oxalis powder (KITININwas estimatedand the optimum dosewasdeterminedusing conductivity, volumetric, atomic absorption spectroscopy and pH measurements. The results show the performance of oxalis in treating Zn plating effluent effectively.In effect, a white crystalline precipitate of zinc oxalate is easily extracted(98,52 % elimination of Zn and ahighsettling rateis observed.The maximum zinc uptake by Oxalis in batch systems is estimated to6,44 mg/g.

  16. Correlation Between Liver Volumetric Computed Tomography Results and Measured Liver Weight: A Tool for Preoperative Planning of Liver Transplant

    NARCIS (Netherlands)

    Sonnemans, L.J.; Hol, J.C.; Monshouwer, R.; Prokop, M.; Klein, W.M.

    2016-01-01

    OBJECTIVES: Before liver transplant, it is necessary to know the size of the organ in advance of the procedure. We studied the correlation between liver volumetric computed tomography results and liver weight. MATERIALS AND METHODS: Postmortem volumetric computed tomography was conducted on cadavers

  17. Study on "double dawn

    Institute of Scientific and Technical Information of China (English)

    刘次沅; 李建科; 周晓陆

    1999-01-01

    The ancient record, "During the first year of King Yi, the day dawned twice at Zheng", has provided important clues to early Chinese chronicles. The astronomical conditions and visible area distributions related to such a "double dawn" event are discussed, and the precision and current problems in the calculations of ancient astronomical phenomena are shown. On such a basis, all the solar eclipses from 1000 BC to 840 BC are calculated and their associated "double dawn" features investigated. The conclusion that the "double dawn" was a solar eclipse occurring on April 21st, 899 BC is corfirmed to be the most reasonable.

  18. Bias Adjusted Precipitation Threat Scores

    Directory of Open Access Journals (Sweden)

    F. Mesinger

    2008-04-01

    Full Text Available Among the wide variety of performance measures available for the assessment of skill of deterministic precipitation forecasts, the equitable threat score (ETS might well be the one used most frequently. It is typically used in conjunction with the bias score. However, apart from its mathematical definition the meaning of the ETS is not clear. It has been pointed out (Mason, 1989; Hamill, 1999 that forecasts with a larger bias tend to have a higher ETS. Even so, the present author has not seen this having been accounted for in any of numerous papers that in recent years have used the ETS along with bias "as a measure of forecast accuracy".

    A method to adjust the threat score (TS or the ETS so as to arrive at their values that correspond to unit bias in order to show the model's or forecaster's accuracy in extit{placing} precipitation has been proposed earlier by the present author (Mesinger and Brill, the so-called dH/dF method. A serious deficiency however has since been noted with the dH/dF method in that the hypothetical function that it arrives at to interpolate or extrapolate the observed value of hits to unit bias can have values of hits greater than forecast when the forecast area tends to zero. Another method is proposed here based on the assumption that the increase in hits per unit increase in false alarms is proportional to the yet unhit area. This new method removes the deficiency of the dH/dF method. Examples of its performance for 12 months of forecasts by three NCEP operational models are given.

  19. Two-dimensional and volumetric airway changes after bimaxillary surgery for class III malocclusion.

    Science.gov (United States)

    Vaezi, Toraj; Zarch, Seyed Hossein Hosseini; Eshghpour, Majid; Kermani, Hamed

    2017-04-01

    Any change in maxilla and mandible position can alter the upper airway, and any decrease in the upper airway can cause sleep disorders. Thus, it is necessary to assess airway changes after repositioning of the maxilla and mandible during orthognathic surgery. The purpose of this study was to evaluate linear and volumetric changes in the upper airway after bimaxillary surgery to correct class III malocclusion via cone-beam computed tomography (CBCT) and to identify correlations between linear and volumetric changes. This was a prospective cohort study. CBCTs from 10 class III patients were evaluated before surgery and three months after. The Wilcoxon one-sample test was used to evaluate the differences in measurements before and after surgery. Spearman's rank correlation coefficient was used to test the correlation between linear and volumetric changes. The results show that the nasopharyngeal space increased significantly, and that this increase correlated with degree of maxillary advancement. No significant changes were found in volumes before and after surgery. A correlation was found between linear and volumetric oropharyngeal changes. Bimaxillary surgical correction of class III malocclusion did not cause statistically significant changes in the posterior airway space.

  20. MATHEMATICAL MODEL FOR DETERMINATION OF VOLUMETRIC OUTPUT OF LUMBER FROM LOGS, CONTAINING SEVERAL QUALITY AREAS

    Directory of Open Access Journals (Sweden)

    Mikryukova E. V.

    2014-12-01

    Full Text Available In the article we present a method of cutting logs, containing several quality areas. For this method, a mathematical model was developed to determine the volumetric output of lumber, which allows to determine the geometric dimensions of the lumber cut from the different quality areas separated concentric circles, depending on size and quality characteristics of logs

  1. 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.

  2. Transplantation and Perfusion of Microvascular Fragments in a Rodent Model of Volumetric Muscle Loss Injury

    Science.gov (United States)

    2014-07-01

    options are available for the treatment of volumetric muscle loss (VML). An important consideration that needs to be addressed for the development ...fibroblasts that underwent vascular and myogenic development in vitro resulted in substantial tissue perfusion when implanted in an abdominal defect...Greene AS (2000) Development of an implantable muscle stimulator: measurement of stimulated angiogenesis and poststimulus vessel regression

  3. 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.

  4. 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.

  5. Using pressure and volumetric approaches to estimate CO2 storage capacity in deep saline aquifers

    NARCIS (Netherlands)

    Thibeau, S.; Bachu, S.; Birkholzer, J.; Holloway, S.; Neele, F.P.; Zou, Q.

    2014-01-01

    Various approaches are used to evaluate the capacity of saline aquifers to store CO2, resulting in a wide range of capacity estimates for a given aquifer. The two approaches most used are the volumetric “open aquifer” and “closed aquifer” approaches. We present four full-scale aquifer cases, where C

  6. Exploration of volumetric cerebral changes, with de micro-MRi, due to psychomotor exercise in mice

    OpenAIRE

    Moës, Florian; Plenevaux, Alain; Becker, Guillaume; Tirelli, Ezio; Lespine, Louis-Ferdinand

    2015-01-01

    It's well know that exercise is good for health .In addition exercise has postive effects on cognition ,neurodegenerative disease and on mood. Some studies show that exercise has effect on brain so the aim of this study is to see if there are volumetric changes due to exercise or not.

  7. Effect of compression paddle tilt correction on volumetric breast density estimation.

    Science.gov (United States)

    Kallenberg, Michiel G J; van Gils, Carla H; Lokate, Mariëtte; den Heeten, Gerard J; Karssemeijer, Nico

    2012-08-21

    For the acquisition of a mammogram, a breast is compressed between a compression paddle and a support table. When compression is applied with a flexible compression paddle, the upper plate may be tilted, which results in variation in breast thickness from the chest wall to the breast margin. Paddle tilt has been recognized as a major problem in volumetric breast density estimation methods. In previous work, we developed a fully automatic method to correct the image for the effect of compression paddle tilt. In this study, we investigated in three experiments the effect of paddle tilt and its correction on volumetric breast density estimation. Results showed that paddle tilt considerably affected accuracy of volumetric breast density estimation, but that effect could be reduced by tilt correction. By applying tilt correction, a significant increase in correspondence between mammographic density estimates and measurements on MRI was established. We argue that in volumetric breast density estimation, tilt correction is both feasible and essential when mammographic images are acquired with a flexible compression paddle.

  8. Follow-up after gamma knife radiosurgery for vestibular schwannomas: volumetric and axial control rates

    NARCIS (Netherlands)

    Timmer, F.C.A.; Hanssens, P.E.; Haren, A.E. van; Overbeeke, J.J. van; Mulder, J.J.S.; Cremers, C.W.R.J.; Graamans, K.

    2011-01-01

    OBJECTIVES/HYPOTHESIS: A prospective long-term follow-up study was conducted to evaluate the results of gamma knife radiosurgery (GKRS) for vestibular schwannoma (VS) patients. Both axial and volumetric measurements are used to determine tumor size during follow-up. STUDY DESIGN: Individual prospect

  9. Empirical correlation of volumetric mass transfer coefficient for a rectangular internal-loop airlift bioreactor

    Science.gov (United States)

    An empirical correlation of volumetric mass transfer coefficient was developed for a pilot scale internal-loop rectangular airlift bioreactor that was designed for biotechnology. The empirical correlation combines classic turbulence theory, Kolmogorov’s isotropic turbulence theory with Higbie’s pen...

  10. Accelerated partial breast irradiation (APBI): are breath-hold and volumetric radiation therapy techniques useful?

    NARCIS (Netherlands)

    Essers, M.; Osman, S.O.; Hol, S.; Donkers, T.; Poortmans, P.M.P.

    2014-01-01

    BACKGROUND: In a selective group of patients accelerated partial breast irradiation (APBI) might be applied after conservative breast surgery to reduce the amount of irradiated healthy tissue. The role of volumetric modulated arc therapy (VMAT) and voluntary moderately deep inspiration breath-hold (

  11. The NCS code of practice for the quality assurance and control for volumetric modulated arc therapy

    NARCIS (Netherlands)

    Mans, Anton; Schuring, Danny; Arends, Mark P.; Vugts, Cornelia A. J. M.; Wolthaus, Jochem W. H.; Lotz, Heidi T.; Admiraal, Marjan; Louwe, Rob J. W.; Ollers, Michel C.; van de Kamer, Jeroen B.

    2016-01-01

    In 2010, the NCS (Netherlands Commission on Radiation Dosimetry) installed a subcommittee to develop guidelines for quality assurance and control for volumetric modulated arc therapy (VMAT) treatments. The report (published in 2015) has been written by Dutch medical physicists and has therefore, ine

  12. Development, Construction, and Operation of a Multisample Volumetric Apparatus for the Study of Gas Adsorption Equilibrium

    Science.gov (United States)

    Ribeiro, Rui P. P. L.; Silva, Ricardo J. S.; Esteves, Isabel A. A. C.; Mota, Jose´ P. B.

    2015-01-01

    The construction of a simple volumetric adsorption apparatus is highlighted. The setup is inexpensive and provides a clear demonstration of gas phase adsorption concepts. The topic is suitable for undergraduate chemistry and chemical engineering students. Moreover, this unit can also provide quantitative data that can be used by young researchers…

  13. 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...

  14. Automated volumetric grid generation for finite element modeling of human hand joints

    Energy Technology Data Exchange (ETDEWEB)

    Hollerbach, K.; Underhill, K. [Lawrence Livermore National Lab., CA (United States); Rainsberger, R. [XYZ Scientific Applications, Inc., Livermore, CA (United States)

    1995-02-01

    We are developing techniques for finite element analysis of human joints. These techniques need to provide high quality results rapidly in order to be useful to a physician. The research presented here increases model quality and decreases user input time by automating the volumetric mesh generation step.

  15. Using pressure and volumetric approaches to estimate CO2 storage capacity in deep saline aquifers

    NARCIS (Netherlands)

    Thibeau, S.; Bachu, S.; Birkholzer, J.; Holloway, S.; Neele, F.P.; Zou, Q.

    2014-01-01

    Various approaches are used to evaluate the capacity of saline aquifers to store CO2, resulting in a wide range of capacity estimates for a given aquifer. The two approaches most used are the volumetric “open aquifer” and “closed aquifer” approaches. We present four full-scale aquifer cases, where

  16. Follow-up after gamma knife radiosurgery for vestibular schwannomas: volumetric and axial control rates

    NARCIS (Netherlands)

    Timmer, F.C.A.; Hanssens, P.E.; Haren, A.E. van; Overbeeke, J.J. van; Mulder, J.J.S.; Cremers, C.W.R.J.; Graamans, K.

    2011-01-01

    OBJECTIVES/HYPOTHESIS: A prospective long-term follow-up study was conducted to evaluate the results of gamma knife radiosurgery (GKRS) for vestibular schwannoma (VS) patients. Both axial and volumetric measurements are used to determine tumor size during follow-up. STUDY DESIGN: Individual

  17. Species-specific contribution of volumetric growth and tissue convergence to posterior body elongation in vertebrates.

    Science.gov (United States)

    Steventon, Ben; Duarte, Fernando; Lagadec, Ronan; Mazan, Sylvie; Nicolas, Jean-François; Hirsinger, Estelle

    2016-05-15

    Posterior body elongation is a widespread mechanism propelling the generation of the metazoan body plan. The posterior growth model predicts that a posterior growth zone generates sufficient tissue volume to elongate the posterior body. However, there are energy supply-related differences between vertebrates in the degree to which growth occurs concomitantly with embryogenesis. By applying a multi-scalar morphometric analysis in zebrafish embryos, we show that posterior body elongation is generated by an influx of cells from lateral regions, by convergence-extension of cells as they exit the tailbud, and finally by a late volumetric growth in the spinal cord and notochord. Importantly, the unsegmented region does not generate additional tissue volume. Fibroblast growth factor inhibition blocks tissue convergence rather than volumetric growth, showing that a conserved molecular mechanism can control convergent morphogenesis through different cell behaviours. Finally, via a comparative morphometric analysis in lamprey, dogfish, zebrafish and mouse, we propose that elongation via posterior volumetric growth is linked to increased energy supply and is associated with an overall increase in volumetric growth and elongation. © 2016. Published by The Company of Biologists Ltd.

  18. Cerebrospinal fluid volumetric MRI mapping as a simple measurement for evaluating brain atrophy

    NARCIS (Netherlands)

    De Vis, J B; Zwanenburg, J J|info:eu-repo/dai/nl/290473683; van der Kleij, L A; Spijkerman, J M; Biessels, G J|info:eu-repo/dai/nl/165576367; Hendrikse, J|info:eu-repo/dai/nl/266590268; Petersen, E T

    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 perform

  19. Ni foam cathode enables high volumetric H2 production in a microbial electrolysis cell

    NARCIS (Netherlands)

    Jeremiasse, A.W.; Hamelers, H.V.M.; Saakes, M.; Buisman, C.J.N.

    2010-01-01

    Valuable, “green” H2 can be produced with a microbial electrolysis cell (MEC). To achieve a high volumetric production rate of high purity H2, a continuous flow MEC with an anion exchange membrane, a flow through bioanode and a flow through Ni foam cathode was constructed. At an electrical energy in

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

    Energy Technology Data Exchange (ETDEWEB)

    Vos, C.G.; Paul, M.A. [VU University Medical Center, Departments of Surgery, Amsterdam (Netherlands); Dahele, M.; Soernsen de Koste, J.R. van; Senan, S. [VU University Medical Center, Departments of Radiation Oncology, Amsterdam (Netherlands); Bahce, I.; Smit, E.F. [VU University Medical Center, Departments of Pulmonary Diseases, Amsterdam (Netherlands); Thunnissen, E. [VU University Medical Center, Departments of Pathology, Amsterdam (Netherlands); Hartemink, K.J. [VU University Medical Center, Departments of Surgery, Amsterdam (Netherlands); Netherlands Cancer Institute - Antoni van Leeuwenhoek Hospital (NKI-AVL), Department of Surgery, Amsterdam (Netherlands)

    2014-02-15

    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{sup 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.)

  1. Toddlers with autism; metabolic, radiologic, and volumetric aspects of brain development

    NARCIS (Netherlands)

    Zeegers, M.

    2006-01-01

    The overall aim of this thesis is to study MR spectroscopic, radiologic, and volumetric brain correlates in very young children with severe developmental disorders; ASD, mental retardation, and language disorder. We wished to examine brain – behaviour relationships in children with ASD at a very you

  2. 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 wit...

  3. 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...

  4. Mathematical Model Defining Volumetric Losses of Hydraulic Oil Compression in a Variable Capacity Displacement Pump

    Directory of Open Access Journals (Sweden)

    Paszota Zygmunt

    2015-01-01

    Full Text Available The objective of the work is to develop the capability of evaluating the volumetric losses of hydraulic oil compression in the working chambers of high pressure variable capacity displacement pump. Volumetric losses of oil compression must be determined as functions of the same parameters, which the volumetric losses due to leakage, resulting from the quality of design solution of the pump, are evaluated as dependent on and also as function of the oil aeration coefficient Ɛ. A mathematical model has been developed describing the hydraulic oil compressibility coefficient klc|Δppi;Ɛ;v as a relation to the ratio ΔpPi/pn of indicated increase ΔpPi of pressure in the working chambers and the nominal pressure pn, to the pump capacity coefficient bP, to the oil aeration coefficient  and to the ratio v/vnof oil viscosity v and reference viscosity vn. A mathematical model is presented of volumetric losses qpvc|ΔpPi;bp;;vof hydraulic oil compression in the pump working chambers in the form allowing to use it in the model of power of losses and energy efficiency

  5. Progress in two-dimensional arrays for real-time volumetric imaging.

    Science.gov (United States)

    Light, E D; Davidsen, R E; Fiering, J O; Hruschka, T A; Smith, S W

    1998-01-01

    The design, fabrication, and evaluation of two dimensional array transducers for real-time volumetric imaging are described. The transducers we have previously described operated at frequencies below 3 MHz and were unwieldy to the operator because of the interconnect schemes used in connecting to the transducer handle. Several new transducers have been developed using new connection technology. A 40 x 40 = 1,600 element, 3.5 MHz array was fabricated with 256 transmit and 256 receive elements. A 60 x 60 = 3,600 element 5.0 MHz array was constructed with 248 transmit and 256 receive elements. An 80 x 80 = 6,400 element, 2.5 MHz array was fabricated with 256 transmit and 208receive elements. 2-D transducer arrays were also developed for volumetric scanning in an intra cardiac catheter, a 10 x 10 = 100 element 5.0 MHz forward-looking array and an 11 x 13 = 143 element 5.0 MHz side-scanning array. The-6dB fractional bandwidths for the different arrays varied from 50% to 63%, and the 50 omega insertion loss for all the transducers was about-64 dB. The transducers were used to generate real-time volumetric images in phantoms and in vivo using the Duke University real time volumetric imaging system, which is capable of generating multiple planes at any desired angle and depth within the pyramidal volume.

  6. Characteristics of wind-induced loss of solid precipitation derived from a Norwegian field study

    Science.gov (United States)

    Petersen-Øverleir, Asgeir; Wolff, Mareile; Isaksen, Ketil; Ødemark, Karianne; Reitan, Trond; Brækkan, Ragnar

    2016-04-01

    Solid precipitation measurements are known to be plagued by under-catch in windy conditions. Adjustment techniques, either based on a dynamic relationship between under-catch and measured determinants or static corrections, are then typically invoked. Such adjustment procedures, especially if the adjustment algorithm is unfit, introduce notable uncertainties that impact hydrological modelling in snow-dominated regions. In 2010, a test-site was established at a mountain plateau in Haukeli, Telemark, Southern Norway. Precipitation data of automatic gauges were compared with a precipitation gauge located in a Double Fence Inter-comparison Reference (DFIR) wind shield construction that served as the reference. A large number of sensors were additionally monitoring supportive meteorological parameters. The study presented in this poster considers data from three winters that were used to study and determine the wind-induced loss of solid precipitation. A general model framework was proposed, and Bayesian methods were used to objectively choose the most plausible sub-model to describe the loss ratio - wind speed - temperature relationship from the Haukeli data. The derived adjustment function is continuous and accounts for measurements of all types of winter precipitation (from rain to dry snow). The analysis shows a non-linear relationship between the loss ratio and wind speed during significant precipitation events, and there is a clear temperature dependency, believed to be mostly related to the precipitation type. The data also displayed a distinctive scatter that is believed to be an artefact mainly caused by neglecting the varying aerodynamic characteristics of the precipitation particles (for a given temperature) as a determinant. The adjustment formula allowed for the first time to derive an adjustment function with a data-tested validity beyond 8-9 m/s and proved a stabilisation of the wind-induced precipitation loss for higher wind speeds. Preliminary tests of

  7. Improved Electronic Control for Electrostatic Precipitators

    Science.gov (United States)

    Johnston, D. F.

    1986-01-01

    Electrostatic precipitators remove particulate matter from smoke created by burning refuse. Smoke exposed to electrostatic field, and particles become electrically charged and migrate to electrically charged collecting surfaces. New microprocessor-based electronic control maintains precipitator power at maximum particulate-collection level. Control automatically senses changes in smoke composition due to variations in fuel or combustion and adjusts precipitator voltage and current accordingly. Also, sensitive yet stable fault detection provided.

  8. Descriptive and predictive evaluation of high resolution Markov chain precipitation models

    DEFF Research Database (Denmark)

    Sørup, Hjalte Jomo Danielsen; Madsen, Henrik; Arnbjerg-Nielsen, Karsten

    2012-01-01

    . Continuous modelling of the Markov process proved attractive because of a marked decrease in the number of parameters. Inclusion of seasonality into the continuous Markov chain model proved difficult. Monte Carlo simulations with the models show that it is very difficult for all the model formulations...... to reproduce the time series on event level. Extreme events with short (10 min), medium (60 min) and long (12 h) durations were investigated because of their importance in urban hydrology. Both the descriptive likelihood based statistics and the predictive Monte Carlo simulation based statistics are valuable......A time series of tipping bucket recordings of very high temporal and volumetric resolution precipitation is modelled using Markov chain models. Both first and second‐order Markov models as well as seasonal and diurnal models are investigated and evaluated using likelihood based techniques...

  9. Neutrinoless double beta decay

    Indian Academy of Sciences (India)

    Kai Zuber

    2012-10-01

    The physics potential of neutrinoless double beta decay is discussed. Furthermore, experimental considerations as well as the current status of experiments are presented. Finally, an outlook towards the future, work on nuclear matrix elements and alternative processes is given.

  10. Double conjoining vas deferens.

    Science.gov (United States)

    Gravesen, R G

    1980-03-01

    The importance of careful palpation of the scrotal contents and follow-up semen analysis when performing vasectomies is proved by this case report of a double vas deferens conjoining into a single vas.

  11. 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

  12. Shifting covariability of North American summer monsoon precipitation with antecedent winter precipitation

    Science.gov (United States)

    McCabe, G.J.; Clark, M.P.

    2006-01-01

    Previous research has suggested that a general inverse relation exists between winter precipitation in the southwestern United states (US) and summer monsoon precipitation. In addition, it has been suggested that this inverse relation between winter precipitation and the magnitude of the southwestern US monsoon breaks down under certain climatic conditions that override the regional winter/monsoon precipitation relations. Results from this new study indicate that the winter/monsoon precipitation relations do not break down, but rather shift location through time. The strength of winter/monsoon precipitation relations, as indexed by 20-year moving correlations between winter precipitation and monsoon precipitation, decreased in Arizona after about 1970, but increased in New Mexico. The changes in these correlations appear to be related to an eastward shift in the location of monsoon precipitation in the southwestern US. This eastward shift in monsoon precipitation and the changes in correlations with winter precipitation also appear to be related to an eastward shift in July/August atmospheric circulation over the southwestern US that resulted in increased monsoon precipitation in New Mexico. Results also indicate that decreases in sea-surface temperatures (SSTs) in the central North Pacific Ocean also may be associated with th changes in correlations between winter and monsoon precipitation. Copyright ?? 2006 Royal Meteorological Society.

  13. 容量法测定方铅矿中高含量银%Volumetric Determination of Silver in Galena Ore

    Institute of Scientific and Technical Information of China (English)

    刘茂荣

    2001-01-01

    A method for KI volumetric determination of high content silver in galena was reported in this paper. Samples with high contents of silicon and lead were decomposed with HNO3-H2SO4-HF.Acidity for the KI volumetric determination of silver was also tested. The results show that in 1.6 mol/L HNO3 medium silver reacts with potassium iodide and forms silver iodide precipitate. The recovery of standard addition for silver by this method is 97.8%~100.4% with precision of 0.92% RSD (n=11). The method is suitable for the dissolution of silver in silicon-bearing silver ores and kerargyrite ores and has been applied to the determination of high content of silver in ores.%报道了采用HNO3-H2SO4-HF溶样,KI容量法测定硅、铅含量较高样品中高含量银的方法。试验了滴定反应的酸度条件。在1.6 mol/L"HNO3介质中,银与碘化钾反应,生成碘化银沉淀。银的标准加入回收率为97.8%~100.4%。精密度试验,相对标准偏差为0.92%(n=11)。该法可溶解含硅银矿及角银矿中的银。方法已被应用于测定矿石中高含量银。

  14. Regression model for generating time series of daily precipitation amounts for climate change impact studies

    Science.gov (United States)

    Buishand, T. A.; Klein Tank, A. M. G.

    1996-05-01

    The precipitation amounts on wet days at De Bilt (the Netherlands) are linked to temperature and surface air pressure through advanced regression techniques. Temperature is chosen as a covariate to use the model for generating synthetic time series of daily precipitation in a CO2 induced warmer climate. The precipitation-temperature dependence can partly be ascribed to the phenomenon that warmer air can contain more moisture. Spline functions are introduced to reproduce the non-monotonous change of the mean daily precipitation amount with temperature. Because the model is non-linear and the variance of the errors depends on the expected response, an iteratively reweighted least-squares technique is needed to estimate the regression coefficients. A representative rainfall sequence for the situation of a systematic temperature rise is obtained by multiplying the precipitation amounts in the observed record with a temperature dependent factor based on a fitted regression model. For a temperature change of 3°C (reasonable guess for a doubled CO2 climate according to the present-day general circulation models) this results in an increase in the annual average amount of 9% (20% in winter and 4% in summer). An extended model with both temperature and surface air pressure is presented which makes it possible to study the additional effects of a potential systematic change in surface air pressure on precipitation.

  15. Circulation factors affecting precipitation over Bulgaria

    Science.gov (United States)

    Nojarov, Peter

    2017-01-01

    The objective of this paper is to determine the influence of circulation factors on precipitation in Bulgaria. The study succeeds investigation on the influence of circulation factors on air temperatures in Bulgaria, as the focus here is directed toward precipitation amounts. Circulation factors are represented through two circulation indices, showing west-east or south-north transport of air masses over Bulgaria and four teleconnection indices (patterns)—North Atlantic Oscillation, East Atlantic, East Atlantic/Western Russia, and Scandinavian. Omega values at 700-hPa level show vertical motions in the atmosphere. Annual precipitation trends are mixed and not statistically significant. A significant decrease of precipitation in Bulgaria is observed in November due to the strengthening of the eastward transport of air masses (strengthening of EA teleconnection pattern) and anticyclonal weather (increase of descending motions in the atmosphere). There is also a precipitation decrease in May and June due to the growing influence of the Azores High. An increase of precipitation happens in September. All this leads to a redistribution of annual precipitation course, but annual precipitation amounts remain the same. However, this redistribution has a negative impact on agriculture and winter ski tourism. Zonal circulation has a larger influence on precipitation in Bulgaria compared to meridional. Eastward transport throughout the year leads to lower than the normal precipitation, and vice versa. With regard to the four teleconnection patterns, winter precipitation in Bulgaria is determined mainly by EA/WR teleconnection pattern, spring and autumn by EA teleconnection pattern, and summer by SCAND teleconnection pattern.

  16. Precipitation Ground Validation over the Oceans

    Science.gov (United States)

    Klepp, C.; Bakan, S.

    2012-04-01

    State-of-the-art satellite derived and reanalysis based precipitation climatologies show remarkably large differences in detection, amount, variability and temporal behavior of precipitation over the oceans. The uncertainties are largest for light precipitation within the ITCZ and for cold season high-latitude precipitation including snowfall. Our HOAPS (Hamburg Ocean Atmosphere Parameters and Fluxes from Satellite data, www.hoaps.org) precipitation retrieval exhibits fairly high accuracy in such regions compared to our ground validation data. However, the statistical basis for a conclusive validation has to be significantly improved with comprehensive ground validation efforts. However, existing in-situ instruments are not designed for precipitation measurements under high wind speeds on moving ships. To largely improve the ground validation data basis of precipitation over the oceans, especially for snow, the systematic data collection effort of the Initiative Pro Klima funded project at the KlimaCampus Hamburg uses automated shipboard optical disdrometers, called ODM470 that are capable of measuring liquid and solid precipitation on moving ships with high accuracy. The main goal of this project is to constrain the precipitation retrievals for HOAPS and the new Global Precipitation Measurement (GPM) satellite constellation. Currently, three instruments are long-term mounted on the German research icebreaker R/V Polarstern (Alfred Wegner Institut) since June 2010, on R/V Akademik Ioffe (P.P.Shirshov Institute of Oceanology, RAS, Moscow, Russia) since September 2010 and on R/V Maria S. Merian (Brise Research, University of Hamburg) since December 2011. Three more instruments will follow shortly on further ships. The core regions for these long-term precipitation measurements comprise the Arctic Ocean, the Nordic Seas, the Labrador Sea, the subtropical Atlantic trade wind regions, the Caribbean, the ITCZ, and the Southern Oceans as far south to Antarctica. This

  17. Mean Annual Precipitation in West-Central Nevada using the Precipitation-Zone Method

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set contains 1971-2000 mean annual precipitation estimates for west-central Nevada. This is a raster data set developed using the precipitation-zone...

  18. Impacts of extreme precipitation and seasonal changes in precipitation on plants

    Directory of Open Access Journals (Sweden)

    M. J. B. Zeppel

    2013-10-01

    Full Text Available The hydrological cycle is predicted to become more intense in future climates, with both larger precipitation events and longer times between events. Redistribution of precipitation may occur both within and across seasons, and the resulting wide fluctuations in soil water content may dramatically affect plants. Though these responses remain poorly understood, recent research in this emerging field suggests the effects of redistributed precipitation may differ from predictions based on previous drought studies. We review available studies on both extreme precipitation (redistribution within seasons and seasonal changes in precipitation (redistribution across seasons on grasslands and forests. Extreme precipitation differentially affected Aboveground Net Primary Productivity (ANPP, depending on whether extreme precipitation led to increased or decreased soil water content (SWC, which differed based on the current precipitation at the site. Specifically, studies to date reported that extreme precipitation decreased ANPP in mesic sites, but, conversely, increased ANPP in xeric sites, suggesting that plant available water is a key factor driving responses to extreme precipitation. Similarly, the effects of seasonal changes in precipitation on ANPP, phenology, and leaf and fruit development varied with the effect on SWC. Reductions in spring or summer generally had negative effects on plants, associated with reduced SWC, while subsequent reductions in autumn or winter had little effect on SWC or plants. Similarly, increased summer precipitation had a more dramatic impact on plants than winter increases in precipitation. The patterns of response suggest xeric biomes may respond positively to extreme precipitation, while comparatively mesic biomes may be more likely to be negatively affected. And, seasonal changes in precipitation during warm or dry seasons may have larger effects than changes during cool or wet seasons. Accordingly, responses to

  19. Application of quantitative precipitation forecasting and precipitation ensemble prediction for hydrological forecasting

    OpenAIRE

    Tao, P.; Tie-Yuan, S.; Zhi-Yuan, Y.; Jun-Chao, W.

    2015-01-01

    The precipitation in the forecast period influences flood forecasting precision, due to the uncertainty of the input to the hydrological model. Taking the ZhangHe basin as the example, the research adopts the precipitation forecast and ensemble precipitation forecast product of the AREM model, uses the Xin Anjiang hydrological model, and tests the flood forecasts. The results show that the flood forecast result can be clearly improved when considering precipitation during the forecast period....

  20. Evaluation of volumetric modulated arc therapy for cranial radiosurgery using multiple noncoplanar arcs

    Energy Technology Data Exchange (ETDEWEB)

    Audet, Chantal; Poffenbarger, Brett A.; Chang, Pauling; Jackson, Paul S.; Lundahl, Robert E.; Ryu, Stephen I.; Ray, Gordon R. [Radiation Oncology Department, Palo Alto Medical Foundation, Palo Alto, California 94301 (United States); Neurosurgery Department, Palo Alto Medical Foundation, Palo Alto, California 94301 (United States); Radiation Oncology Department, Palo Alto Medical Foundation, Palo Alto, California 94301 (United States); Neurosurgery Department, Palo Alto Medical Foundation, Palo Alto, California 94301 (United States); Radiation Oncology Department, Palo Alto Medical Foundation, Palo Alto, California 94301 (United States)

    2011-11-15

    Purpose: To evaluate a commercial volumetric modulated arc therapy (VMAT), using multiple noncoplanar arcs, for linac-based cranial radiosurgery, as well as evaluate the combined accuracy of the VMAT dose calculations and delivery. Methods: Twelve patients with cranial lesions of variable size (0.1-29 cc) and two multiple metastases patients were planned (Eclipse RapidArc AAA algorithm, v8.6.15) using VMAT (1-6 noncoplanar arcs), dynamic conformal arc (DCA, {approx}4 arcs), and IMRT (nine static fields). All plans were evaluated according to a conformity index (CI), healthy brain tissue doses and volumes, and the dose to organs at risk. A 2D dose distribution was measured (Varian Novalis Tx, HD120 MLC, 1000 MU/min, 6 MV beam) for the {approx}4 arc VMAT treatment plans using calibrated film dosimetry. Results: The CI (0-1 best) average for all plans was best for {approx}4 noncoplanar arc VMAT at 0.86 compared with {approx}0.78 for IMRT and a single arc VMAT and 0.68 for DCA. The volumes of healthy brain receiving 50% of the prescribed target coverage dose or more (V{sub 50%}) were lowest for the four arc VMAT [RA(4)] and DCA plans. The average ratio of the V{sub 50%} for the other plans to the RA(4) V{sub 50%} were 1.9 for a single noncoplanar arc VMAT [RA(1nc)], 1.4 for single full coplanar arc VMAT [RA(1f)] and 1.3 for IMRT. The V{sub 50%} improved significantly for single isocenter multiple metastases plan when two noncoplanar VMAT arcs were added to a full single coplanar one. The maximum dose to 5 cc of the outer 1 cm rim of healthy brain which one may want to keep below nonconsequential doses of 300-400 cGy, was 2-3 times greater for IMRT, RA(1nc) and RA(1f) plans compared with the multiple noncoplanar arc DCA and RA(4) techniques. Organs at risk near (0-4 mm) to targets were best spared by (i) single noncoplanar arcs when the targets are lateral to the organ at risk and (ii) by skewed nonvertical planes of IMRT fields when the targets are not lateral to the

  1. Nucleation pathway in coherent precipitation

    Science.gov (United States)

    Philippe, T.; Blavette, D.

    2011-12-01

    The non-classical nucleation pathway of coherent precipitates has been computed through minimisation of the nucleation barrier in the composition (c)-size (R) space to predict the evolution of nucleus composition. The generalized Gibbs model, developed by Schmelzer et al. [J. Chem. Phys. 112 (2000) p.3820; J. Colloid Interface Sci. 272 (2004) p.109], has been extended to include misfit elastic energy. The composition of critical embryos c* was found to be independent of the interfacial constant. The composition of critical nuclei (c*) decreased with supersaturation. The elastic energy increased both c* and the nucleation barrier, as well as R*. The evolution of nucleus composition (c) as a function of size (R) along the minimum energy pathway was computed. Nucleation only starts when a size threshold is exceeded. Then, rapid enrichment to the expected composition (c β) precedes a constant composition regime. However, for small supersaturations, the change in cluster composition can occur sharply for a very small radius and then the composition slowly increased with a significant change in size. Coherency misfit energy was found to slow down the evolution of nuclei composition with R. The model was compared to experimental results.

  2. Gas sorption and the consequent volumetric and permeability change of coal

    Science.gov (United States)

    Lin, Wenjuan

    Experimental and numerical investigations of gas sorption on coal, and the subsequent volumetric and permeability changes of the coal were conducted. The goals of the study were to investigate the magnitude of permeability change caused by gas sorption, and develop an algorithm to simulate numerically gas sorption and sorption-induced permeability change. The amount of gas sorption and the subsequent volumetric and permeability change of coal samples as a function of pore pressure and injection gas composition were measured in the laboratory. A constant effective confining pressure (difference between the confining pressure and pore pressure) was maintained in the process of the experiments; therefore, the role of effective stress on permeability was eliminated. Several gases, including pure CO2, pure N2, and binary mixtures of CO2 and N2 of various compositions were used as the injection gas. The coal sample was first allowed to adsorb an injection gas fully at a particular pressure. The total amount (moles) of adsorption was calculated based on a volumetric method. After adsorption equilibrium was reached, gas samples were taken from the equilibrium gaseous phase and analyzed afterwards. The composition of the gaseous phase prior to and after the adsorption was used to calculate the composition of the adsorbed phase based on material balance. Permeability of the sample was then measured by flowing the injection gas through the core at varying pressure gradient or varying flow rate, and an average permeability was obtained based on Darcy's law for compressible systems. The change of the total volume of the core was monitored and recorded in the whole process of the experiment. Volumetric strain was thereby calculated. Experimental results showed that the greater the pressure the greater the amount of adsorption for all tested gases. At the same pressure, the amount of adsorption was greater for CO2 than N2. For the binary mixtures, the greater the fraction of CO 2

  3. Precipitation of humic acid with divalent ions

    DEFF Research Database (Denmark)

    Andersen, Niels Peder Raj; Mikkelsen, Lene Haugaard; Keiding, Kristian

    2001-01-01

    and Ba2+. The phase diagram model can not account for the observed precipitation in region III and However, in region IV the HA appears to posses colloidal properties, which is supported by precipitation taking place at a constant zeta-potential -21mV with the same amount of added barium ion regardless...

  4. Dissolution of ordered precipitates under ion irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Camus, E.; Bourdeau, F.; Abromeit, C.; Wanderka, N.; Wollenberger, H. [Hahn-Meitner-Institut Berlin GmbH (Germany)

    1995-09-01

    The stability of the ordered {gamma}{prime} precipitates under 300-keV Ni{sup +} irradiation was investigated between room temperature and 623 K. The two competing mechanisms of destabilization by cascade producing irradiation, i.e. disordering and dissolution of the {gamma}{prime} precipitates in Nimonic PE16 alloy, has been studied separately by electron microscopy and field-ion microscopy with atom probe. At high temperatures, the precipitates are stable. At intermediate temperatures, the precipitates dissolve by ballistic mixing into the matrix, but the interface is restored by the radiation-enhanced atomic jumps. The order in the precipitates remains stable. At low temperatures, the precipitates are dissolved by atomic mixing. The dissolution proceeds in a diffusional manner with a diffusion coefficient normalized by the displacement rate D/K = 0.75 nm{sup 2}dpa{sup {minus}1}. The precipitates become disordered by a fluence of 0.1 dpa, whereas precipitate dissolution needs much higher fluences.

  5. MAXIS Balloon Observations of Electron Microburst Precipitation

    Science.gov (United States)

    Millan, R. M.; Hunter, A. E.; McCarthy, M. P.; Lin, R. P.; Smith, D. M.

    2003-12-01

    Quantifying and understanding losses is an integral part of understanding relativistic electron variability in the radiation belts. SAMPEX observations indicate that electron microburst precipitation is a major loss mechanism during active periods; the loss of relativistic electrons during a six hour period due to microburst precipitation was recently estimated to be comparable to the total number of trapped electrons in the outer zone (Lorentzen et al., 2001). Microburst precipitation was first observed from a balloon (Anderson and Milton, 1964), but these early measurements were only sensitive to MAXIS 2000 long duration balloon campaign. MAXIS was launched from McMurdo Station in Antarctica carrying a germanium spectrometer, a BGO scintillator and two X-ray imagers designed to measure the bremsstrahlung produced by precipitating electrons. The balloon circumnavigated the south pole in 18 days covering magnetic latitudes ranging from 58o-90o South. During the week following a moderate geomagnetic storm (with Dst reaching -91 nT), MAXIS detected a total of over 16 hours of microburst precipitation. We present high resolution spectra obtained with the MAXIS germanium spectrometer which allow us to determine the precipitating electron energy distribution. The precipitating distribution will then be compared to the trapped distribution measured by the GPS and LANL satellites. We also examine the spatial distribution of the precipitation.

  6. Study of asphaltene precipitation by Calorimetry

    DEFF Research Database (Denmark)

    Verdier, Sylvain Charles Roland; Plantier, Frédéric; Bessières, David;

    2007-01-01

    of experiments showed that weak forces determine precipitation. Indeed, isothermal titration calorimetry could not detect any clear signal although this technique can detect low-energy transitions such as liquid-liquid equilibrium and rnicellization. The second series of tests proved that precipitation caused...

  7. Asphaltene precipitates in oil production wells

    DEFF Research Database (Denmark)

    Kleinitz, W,; Andersen, Simon Ivar

    1998-01-01

    At the beginning of production in a southern German oil field, flow blockage was observed during file initial stage of production from the oil wells. The hindrance was caused by the precipitation of asphaltenes in the proximity of the borehole and in the tubings. The precipitates were of solid...

  8. Investigation of Asphaltene Precipitation at Elevated Temperature

    DEFF Research Database (Denmark)

    Andersen, Simon Ivar; Lindeloff, Niels; Stenby, Erling Halfdan

    1998-01-01

    In order to obtain quantitative data on the asphaltene precipitation induced by the addition of n-alkane (heptane) at temperatures above the normal boiling point of the precipitant, a high temperature/high pressure filtration apparatus has been constructed. Oil and alkane are mixed at the appropr...

  9. 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.

  10. Ni adsorption and Ni-Al LDH precipitation in a sandy aquifer: An experimental and mechanistic modeling study

    NARCIS (Netherlands)

    Regelink, I.C.; Temminghoff, E.J.M.

    2011-01-01

    Mining activities and industries have created nickel (Ni) contaminations in many parts of the world. The objective of this study is to increase our understanding of Ni adsorption and Nickel-Aluminium Layered Double Hydroxide (Ni-Al LDH) precipitation to reduce Ni mobility in a sandy soil aquifer. At

  11. Precipitation hardening in 350 grade maraging steel

    Energy Technology Data Exchange (ETDEWEB)

    Viswanathan, U.K. (Bhabha Atomic Research Centre, Bombay, (India). Radiometallurgy Div.); Dey, G.K. (Bhabha Atomic Research Centre, Bombay, (India). Metallurgy Division); Asundi, M.K. (Government Colony, Bombay, (India))

    1993-11-01

    Evolution of microstructure in 350 grade commercial maraging steel has been examined. In the earlier stages of aging, the strengthening phases are formed by the heterogeneous precipitation, and these phases have been identified as intermetallic compounds of the Ni[sub 3] (Ti, Mo) and Fe[sub 2]Mo types. The kinetics of precipitation are studied in terms of the activation energy by carrying out isothermal hardness measurements of aged material. The mechanical properties in the peak-aged and overaged conditions were evaluated and the flow behavior examined. The overaging behavior of the steel has been studied and the formation of austenite of different morphologies identified. The crystallography of the austenite has been examined in detail. From the microstructural examination of peak-aged and deformed samples, it could be inferred that the dislocation-precipitate interaction is by precipitate shearing. Increased work hardening of the material in the overaged condition was suggestive of looping of precipitates by dislocations.

  12. Precipitation hardening in 350 grade maraging steel

    Science.gov (United States)

    Viswanathan, U. K.; Dey, G. K.; Asundi, M. K.

    1993-11-01

    Evolution of microstructure in a 350 grade commercial maraging steel has been examined. In the earlier stages of aging, the strengthening phases are formed by the heterogeneous precipitation, and these phases have been identified as intermetallic compounds of the Ni3 (Ti, Mo) and Fe2Mo types. The kinetics of precipitation are studied in terms of the activation energy by carrying out isothermal hardness measurements of aged material. The mechanical properties in the peak-aged and overaged conditions were evaluated and the flow behavior examined. The overaging behavior of the steel has been studied and the formation of austenite of different morphologies identified. The crystallography of the austenite has been examined in detail. From the microstructural examination of peak-aged and deformed samples, it could be inferred that the dislocation-precipitate interaction is by precipitate shearing. Increased work hardening of the material in the overaged condition was suggestive of looping of precipitates by dislocations.

  13. Validation of the relative insensitivity of volumetric-modulated arc therapy (VMAT) plan quality to gantry space resolution.

    Science.gov (United States)

    Murtaza, Ghulam; Cora, Stefania; Khan, Ehsan Ullah

    2016-12-14

    Volumetric-modulated arc therapy (VMAT) is an efficient form of radiotherapy used to deliver intensity-modulated radiotherapy beams. The aim of this study was to investigate the relative insensitivity of VMAT plan quality to gantry angle spacing (GS). Most previous VMAT planning and dosimetric work for GS resolution has been conducted for single arc VMAT. In this work, a quantitative comparison of dose-volume indices (DIs) was made for partial-, single- and double-arc VMAT plans optimized at 2°, 3° and 4° GS, representing a large variation in deliverable multileaf collimator segments. VMAT plans of six prostate cancer and six head-and-neck cancer patients were simulated for an Elekta SynergyS® Linac (Elekta Ltd, Crawley, UK), using the SmartArc™ module of Pinnacle³ TPS, (version 9.2, Philips Healthcare). All optimization techniques generated clinically acceptable VMAT plans, except for the single-arc for the head-and-neck cancer patients. Plan quality was assessed by comparing the DIs for the planning target volume, organs at risk and normal tissue. A GS of 2°, with finest resolution and consequently highest intensity modulation, was considered to be the reference, and this was compared with GS 3° and 4°. The differences between the majority of reference DIs and compared DIs were plan optimization time and pretreatment (phantom) dosimetric calculation time, supported the use of a GS of 4°. The ArcCHECK™ phantom-measured dosimetric agreement verifications resulted in a >95.0% passing rate, using the criteria for γ (3%, 3 mm). In conclusion, a GS of 4° is an optimal choice for minimal usage of planning resources without compromise of plan quality.

  14. 4D ultrafast ultrasound flow imaging: in vivo quantification of arterial volumetric flow rate in a single heartbeat

    Science.gov (United States)

    Correia, Mafalda; Provost, Jean; Tanter, Mickael; Pernot, Mathieu

    2016-12-01

    We present herein 4D ultrafast ultrasound flow imaging, a novel ultrasound-based volumetric imaging technique for the quantitative mapping of blood flow. Complete volumetric blood flow distribution imaging was achieved through 2D tilted plane-wave insonification, 2D multi-angle cross-beam beamforming, and 3D vector Doppler velocity components estimation by least-squares fitting. 4D ultrafast ultrasound flow imaging was performed in large volumetric fields of view at very high volume rate (>4000 volumes s-1) using a 1024-channel 4D ultrafast ultrasound scanner and a 2D matrix-array transducer. The precision of the technique was evaluated in vitro by using 3D velocity vector maps to estimate volumetric flow rates in a vessel phantom. Volumetric Flow rate errors of less than 5% were found when volumetric flow rates and peak velocities were respectively less than 360 ml min-1 and 100 cm s-1. The average volumetric flow rate error increased to 18.3% when volumetric flow rates and peak velocities were up to 490 ml min-1 and 1.3 m s-1, respectively. The in vivo feasibility of the technique was shown in the carotid arteries of two healthy volunteers. The 3D blood flow velocity distribution was assessed during one cardiac cycle in a full volume and it was used to quantify volumetric flow rates (375  ±  57 ml min-1 and 275  ±  43 ml min-1). Finally, the formation of 3D vortices at the carotid artery bifurcation was imaged at high volume rates.

  15. 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

  16. A comparative verification of high resolution precipitation forecasts using model output statistics

    Science.gov (United States)

    van der Plas, Emiel; Schmeits, Maurice; Hooijman, Nicolien; Kok, Kees

    2017-04-01

    Verification of localized events such as precipitation has become even more challenging with the advent of high-resolution meso-scale numerical weather prediction (NWP). The realism of a forecast suggests that it should compare well against precipitation radar imagery with similar resolution, both spatially and temporally. Spatial verification methods solve some of the representativity issues that point verification gives rise to. In this study a verification strategy based on model output statistics is applied that aims to address both double penalty and resolution effects that are inherent to comparisons of NWP models with different resolutions. Using predictors based on spatial precipitation patterns around a set of stations, an extended logistic regression (ELR) equation is deduced, leading to a probability forecast distribution of precipitation for each NWP model, analysis and lead time. The ELR equations are derived for predictands based on areal calibrated radar precipitation and SYNOP observations. The aim is to extract maximum information from a series of precipitation forecasts, like a trained forecaster would. The method is applied to the non-hydrostatic model Harmonie (2.5 km resolution), Hirlam (11 km resolution) and the ECMWF model (16 km resolution), overall yielding similar Brier skill scores for the 3 post-processed models, but larger differences for individual lead times. Besides, the Fractions Skill Score is computed using the 3 deterministic forecasts, showing somewhat better skill for the Harmonie model. In other words, despite the realism of Harmonie precipitation forecasts, they only perform similarly or somewhat better than precipitation forecasts from the 2 lower resolution models, at least in the Netherlands.

  17. Enhanced precipitation promotes decomposition and soil C stabilization in semiarid ecosystems, but seasonal timing of wetting matters

    Science.gov (United States)

    Campos, Xochi; Germino, Matthew; de Graaff, Marie-Anne

    2017-01-01

    AimsChanging precipitation regimes in semiarid ecosystems will affect the balance of soil carbon (C) input and release, but the net effect on soil C storage is unclear. We asked how changes in the amount and timing of precipitation affect litter decomposition, and soil C stabilization in semiarid ecosystems.MethodsThe study took place at a long-term (18 years) ecohydrology experiment located in Idaho. Precipitation treatments consisted of a doubling of annual precipitation (+200 mm) added either in the cold-dormant season or in the growing season. Experimental plots were planted with big sagebrush (Artemisia tridentata), or with crested wheatgrass (Agropyron cristatum). We quantified decomposition of sagebrush leaf litter, and we assessed organic soil C (SOC) in aggregates, and silt and clay fractions.ResultsWe found that: (1) increased precipitation applied in the growing season consistently enhanced decomposition rates relative to the ambient treatment, and (2) precipitation applied in the dormant season enhanced soil C stabilization.ConclusionsThese data indicate that prolonged increases in precipitation can promote soil C storage in semiarid ecosystems, but only if these increases happen at times of the year when conditions allow for precipitation to promote plant C inputs rates to soil.

  18. Project Half Double

    DEFF Research Database (Denmark)

    Ehlers, Michael; Adland, Karoline Thorp; Boston, Nicolai Elborough

    Project Half Double has a clear mission to succeed in finding a project methodology that can increase the success rate of our projects while increasing the speed at which we generate new ideas and develop new products and services. Chaos and complexity should be seen as a basic condition...... and as an opportunity rather than a threat and a risk. We are convinced that by doing so, we can strengthen Denmark’s competitiveness and play an important role in the battle for jobs and future welfare. The overall goal is to deliver “projects in half the time with double the impact”, where projects in half the time...... should be understood as half the time to impact (benefit realisation, effect is achieved) and not as half the time for project execution. The purpose of Project Half Double is to improve Danish industrial competitiveness by radically increasing the pace and impact of the development and innovation...

  19. Application of quantitative precipitation forecasting and precipitation ensemble prediction for hydrological forecasting

    Directory of Open Access Journals (Sweden)

    P. Tao

    2015-05-01

    Full Text Available The precipitation in the forecast period influences flood forecasting precision, due to the uncertainty of the input to the hydrological model. Taking the ZhangHe basin as the example, the research adopts the precipitation forecast and ensemble precipitation forecast product of the AREM model, uses the Xin Anjiang hydrological model, and tests the flood forecasts. The results show that the flood forecast result can be clearly improved when considering precipitation during the forecast period. Hydrological forecast based on Ensemble Precipitation prediction gives better hydrological forecast information, better satisfying the need for risk information for flood prevention and disaster reduction, and has broad development opportunities.

  20. Neural network based daily precipitation generator (NNGEN-P)

    Energy Technology Data Exchange (ETDEWEB)

    Boulanger, Jean-Philippe [LODYC, UMR CNRS/IRD/UPMC, Paris (France); University of Buenos Aires, Departamento de Ciencias de la Atmosfera y los Oceanos, Facultad de Ciencias Exactas y Naturales, Buenos Aires (Argentina); Martinez, Fernando; Segura, Enrique C. [University of Buenos Aires, Departamento de Computacion, Facultad de Ciencias Exactas y Naturales, Buenos Aires (Argentina); Penalba, Olga [University of Buenos Aires, Departamento de Ciencias de la Atmosfera y los Oceanos, Facultad de Ciencias Exactas y Naturales, Buenos Aires (Argentina)

    2007-02-15

    Daily weather generators are used in many applications and risk analyses. The present paper explores the potential of neural network architectures to design daily weather generator models. Focusing this first paper on precipitation, we design a collection of neural networks (multi-layer perceptrons in the present case), which are trained so as to approximate the empirical cumulative distribution (CDF) function for the occurrence of wet and dry spells and for the precipitation amounts. This approach contributes to correct some of the biases of the usual two-step weather generator models. As compared to a rainfall occurrence Markov model, NNGEN-P represents fairly well the mean and standard deviation of the number of wet days per month, and it significantly improves the simulation of the longest dry and wet periods. Then, we compared NNGEN-P to three parametric distribution functions usually applied to fit rainfall cumulative distribution functions (Gamma, Weibull and double-exponential). A data set of 19 Argentine stations was used. Also, data corresponding to stations in the United States, in Europe and in the Tropics were included to confirm the results. One of the advantages of NNGEN-P is that it is non-parametric. Unlike other parametric function, which adapt to certain types of climate regimes, NNGEN-P is fully adaptive to the observed cumulative distribution functions, which, on some occasions, may present complex shapes. On-going works will soon produce an extended version of NNGEN to temperature and radiation. (orig.)

  1. Double arch mirror study

    Science.gov (United States)

    Vukobratovich, D.; Hillman, D.

    1983-01-01

    The development of a method of mounting light weight glass mirrors for astronomical telescopes compatible with the goals of the Shuttle Infrared Telescope Facility (SIRTF) was investigated. A 20 in. diameter double arch lightweight mirror previously fabricated was modified to use a new mount configuration. This mount concept was developed and fabricated. The mounting concept of the double mounting mirror is outlined. The modifications made to the mirror, fabrication of the mirror mount, and room temperature testing of the mirror and mount and the extension of the mirror and mount concept to a full size (40 in. diameter) primary mirror for SIRTF are discussed.

  2. John Deakin: Double Exposures

    Directory of Open Access Journals (Sweden)

    Paul Rousseau

    2015-11-01

    Full Text Available In this series of short films made by Jonathan Law, the art historian James Boaden, and the curator of The John Deakin Archive, Paul Rousseau, discuss the double-exposure images made by the photographer John Deakin (1912-1972 in the 1950s and 1960s. The films ask you, firstly, to look closely at the images being discussed. Each one begins with a sustained and intense shot of a single image before opening up to a wide-ranging discussion about Deakin, double exposures, and photography.

  3. Double Beta Decay

    CERN Document Server

    Elliott, Steven R

    2011-01-01

    At least one neutrino has a mass of about 50 meV or larger. However, the absolute mass scale for the neutrino remains unknown. Furthermore, the critical question: Is the neutrino its own antiparticle? is unanswered. Studies of double beta decay offer hope for determining the absolute mass scale. In particular, zero-neutrino double beta decay (\\BBz) can address the issues of lepton number conservation, the particle-antiparticle nature of the neutrino, and its mass. A summary of the recent results in \\BBz, and the related technologies will be discussed in the context of the future \\BBz\\ program.

  4. Double-helix stellarator

    Energy Technology Data Exchange (ETDEWEB)

    Moroz, P.E.

    1997-09-01

    A new stellarator configuration, the Double-Helix Stellarator (DHS), is introduced. This novel configuration features a double-helix center post as the only helical element of the stellarator coil system. The DHS configuration has many unique characteristics. One of them is the extreme low plasma aspect ratio, A {approx} 1--1.2. Other advantages include a high enclosed volume, appreciable rotational transform, and a possibility of extreme-high-{beta} MHD equilibria. Moreover, the DHS features improved transport characteristics caused by the absence of the magnetic field ripple on the outboard of the torus. Compactness, simplicity and modularity of the coil system add to the DHS advantages for fusion applications.

  5. Project Half Double

    DEFF Research Database (Denmark)

    Svejvig, Per; Gerstrøm, Anna; Frederiksen, Signe Hedeboe

    The Half Double mission: Project Half Double has a clear mission. We want to succeed in finding a project methodology that can increase the success rate of our projects while increasing the development speed of new products and services. We are convinced that by doing so we can strengthen...... projects and to document their development. The purpose of this addendum is thus to document the development in the pilot projects from June 2016 to January 2017 with particular focus on the impact they have created. This Addendum is a supplement and should be read in conjunction with the Phase 1 report...

  6. Reflection Positive Doubles

    CERN Document Server

    Jaffe, Arthur

    2016-01-01

    Here we introduce reflection positive doubles, a general framework for reflection positivity, covering a wide variety of systems in statistical physics and quantum field theory. These systems may be bosonic, fermionic, or parafermionic in nature. Within the framework of reflection positive doubles, we give necessary and sufficient conditions for reflection positivity. We use a reflection-invariant cone to implement our construction. Our characterization allows for a direct interpretation in terms of coupling constants, making it easy to check in concrete situations. We illustrate our methods with numerous examples.

  7. Precipitation behavior and effect of new precipitated β phase in AZ80 magnesium alloy

    Institute of Scientific and Technical Information of China (English)

    TANG Wei; HAN En-hou; XU Yong-bo; LIU Lu

    2006-01-01

    Granular precipitate that was a new kind of β-Mg17Al12 phase found in aged AZ80 wrought Mg alloy at all aging temperature was studied. The structure and precipitation behavior of this granular β-Mg17Al12 precipitate were studied by environmental scanning electron microscopy (ESEM) and transmission electron microscopy (TEM). The effect of the granular precipitate on mechanical properties of AZ80 alloy was also studied. The new precipitate that was granular and nucleated both on grain boundaries (GBs) and twin boundaries, has the same crystal structure and lattice parameter as those of the continuous or discontinuous precipitated β-Mg17Al12. And the nucleation and growth of the granular precipitate are faster than those of the other two precipitates at higher temperatures (above 583 K), but are suppressed at lower temperatures (below 423 K). At lower temperatures, the discontinuous β-Mg17Al12 precipitates firstly and the granular β-Mg17Al12 precipitates after aged more than 40 h. The crack is easily nucleated on the phase boundaries of granular phase and matrix because of the weak binding force. As a result, the strength and ductility of AZ80 Mg alloy are decreased by the granular β-Mg17Al12 precipitate.

  8. 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.

  9. Volumetric analysis of complex lunar craters - Implications for basin ring formation

    Science.gov (United States)

    Hale, W. S.; Grieve, R. A. F.

    1982-01-01

    The crater to basin transition in complex lunar craters is characterized by combining morphological and volumetric analyses of their central peaks with subsurface data from terrestrial complex impact structures which suggest that the amount of uplifted material, as judged from its depth of origin, continues to increase with increasing rim diameter. This latter phenomenon implies that a redistribution of uplifted material away from a centralized peak may occur in the larger craters. The morphological and volumetric changes described occur over a rim diameter range of 51-80 km, which is considerably lower than the previously proposed range for the crater to basin transition of 140-175 km. Evidence is given in support of a crater to basin transition which begins at 51-80 km, and is characterized by a relative reduction in central peak volume and a development of rings of floor roughening which may be precursors of peak ring development.

  10. 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.

  11. Open Volumetric Mesh-An Efficient Data Structure for Tetrahedral and Hexa-hedral Meshes

    Institute of Scientific and Technical Information of China (English)

    XIAN Chu-hua; LI Gui-qing; GAO Shu-ming

    2013-01-01

    This work introduces a scalable and efficient topological structure for tetrahedral and hexahedral meshes. The design of the data structure aims at maximal flexibility and high performance. It provides a high scalability by using hierarchical representa-tions of topological elements. The proposed data structure is array-based, and it is a compact representation of the half-edge data structure for volume elements and half-face data structure for volumetric meshes. This guarantees constant access time to the neighbors of the topological elements. In addition, an open-source implementation named Open Volumetric Mesh (OVM) of the pro-posed data structure is written in C++using generic programming concepts.

  12. Selective-plane illumination microscopy for high-content volumetric biological imaging

    Science.gov (United States)

    McGorty, Ryan; Huang, Bo

    2016-03-01

    Light-sheet microscopy, also named selective-plane illumination microscopy, enables optical sectioning with minimal light delivered to the sample. Therefore, it allows one to gather volumetric datasets of developing embryos and other light-sensitive samples over extended times. We have configured a light-sheet microscope that, unlike most previous designs, can image samples in formats compatible with high-content imaging. Our microscope can be used with multi-well plates or with microfluidic devices. In designing our optical system to accommodate these types of sample holders we encounter large optical aberrations. We counter these aberrations with both static optical components in the imaging path and with adaptive optics. Potential applications of this microscope include studying the development of a large number of embryos in parallel and over long times with subcellular resolution and doing high-throughput screens on organisms or cells where volumetric data is necessary.

  13. Light-Curing Volumetric Shrinkage in Dimethacrylate-Based Dental Composites by Nanoindentation and PAL Study

    Science.gov (United States)

    Shpotyuk, Olha; Adamiak, Stanislaw; Bezvushko, Elvira; Cebulski, Jozef; Iskiv, Maryana; Shpotyuk, Oleh; Balitska, Valentina

    2017-01-01

    Light-curing volumetric shrinkage in dimethacrylate-based dental resin composites Dipol® is examined through comprehensive kinetics research employing nanoindentation measurements and nanoscale atomic-deficient study with lifetime spectroscopy of annihilating positrons. Photopolymerization kinetics determined through nanoindentation testing is shown to be described via single-exponential relaxation function with character time constants reaching respectively 15.0 and 18.7 s for nanohardness and elastic modulus. Atomic-deficient characteristics of composites are extracted from positron lifetime spectra parameterized employing unconstrained x3-term fitting. The tested photopolymerization kinetics can be adequately reflected in time-dependent changes observed in average positron lifetime (with 17.9 s time constant) and fractional free volume of positronium traps (with 18.6 s time constant). This correlation proves that fragmentation of free-volume positronium-trapping sites accompanied by partial positronium-to-positron traps conversion determines the light-curing volumetric shrinkage in the studied composites.

  14. Computational determination of absorbed dose distributions from multiple volumetric gamma ray sources

    Science.gov (United States)

    Zhou, Chuanyu; Inanc, Feyzi

    2002-05-01

    Determination of absorbed dose distributions is very important in brachytherapy procedures. The typical computation involves superposition of absorbed dose distributions from a single seed to compute the combined absorbed dose distribution formed by multiple seeds. This approach does not account for the shadow effect caused by the metallic nature of volumetric radioactive seeds. Since this shadow effect will cause deviations from the targeted dose distribution, it may have important implications on the success of the procedures. We demonstrated accuracy of our deterministic algorithms for isotropic point sources in the past. We will show that we now have the capability of computing absorbed dose distributions from multiple volumetric seeds and demonstrate that our results are quite close to the results published in the literature.

  15. 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.

  16. Volumetric properties of binary mixtures of benzene with cyano-based ionic liquids

    Science.gov (United States)

    Gonfa, Girma; Bustam, Mohamad Azmi; Moniruzzaman, Muhammad; Murugesan, Thanabalan

    2014-10-01

    The objective of this study is to investigate the volumetric properties of the binary mixtures comprised benzene and two ionic liquids, 1-butyl-3-methylimidazolium thiocyanate ([BMIM][SCN]) and 1-butyl-3-methyl- imidazolium dicyanamide ([ BMIM ][ N ( CN )2]( . Densities (ρ) and viscosities (μ) of the binary mixtures were measured over a temperature range of 293.15 to 323.15 K and at atmospheric pressure. Excess molar volumes and viscosity deviations were calculated from the experimental densities and viscosities values. The volumetric properties of the mixtures were changed significantly with the change of compositions and temperatures. It was also found that the value of excess molar volume and viscosity deviations were negative (-ve) over the entire range of compositions. The results have been interpreted in terms of molecular interactions of ILs and benzene.

  17. Holographic time-resolved particle tracking by means of three-dimensional volumetric deconvolution

    CERN Document Server

    Latychevskaia, Tatiana

    2014-01-01

    Holographic particle image velocimetry allows tracking particle trajectories in time and space by means of holography. However, the drawback of the technique is that in the three-dimensional particle distribution reconstructed from a hologram, the individual particles can hardly be resolved due to the superimposed out-of-focus signal from neighboring particles. We demonstrate here a three-dimensional volumetric deconvolution applied to the reconstructed wavefront which results in resolving all particles simultaneously in three-dimensions. Moreover, we apply the three-dimensional volumetric deconvolution to reconstructions of a time-dependent sequence of holograms of an ensemble of polystyrene spheres moving in water. From each hologram we simultaneously resolve all particles in the ensemble in three dimensions and from the sequence of holograms we obtain the time-resolved trajectories of individual polystyrene spheres.

  18. Development of a Diver-Operated Single Camera Volumetric Velocimetry System

    Science.gov (United States)

    Troutman, Valerie; Dabiri, John

    2016-11-01

    The capabilities of a single camera, volumetric velocimetry system for in situ measurement in marine environments are demonstrated by imaging a well-characterized flow in a laboratory environment. This work represents the first stages in the design of a SCUBA-diver operated system to study organisms and biological processes under the natural light in the water column. This system is primarily composed of a volumetric particle tracking diagnostic to investigate fluid-animal interactions. A target domain size of a 20 cm sided cube is sought as a key design feature for the capability of capturing the flow around a variety of benthic and freely swimming organisms. The integration of the particle tracking system with additional diagnostics will be discussed.

  19. Tunable Gravimetric and Volumetric Hydrogen Storage Capacities in Polyhedral Oligomeric Silsesquioxane Frameworks.

    Science.gov (United States)

    Deshmukh, Amol; Chiu, Cheng-Chau; Chen, Yun-Wen; Kuo, Jer-Lai

    2016-09-28

    We study the hydrogen adsorption in porous frameworks composed of silsesquioxane cages linked via boron substituted aromatic structures by first-principles modeling. Such polyhedral oligomeric silsesquioxane (POSS) frameworks can be further modified by decorating them with metal atoms binding to the ring structures of the linkers. We have considered Sc- and Ti-doped frameworks which bind H2 via so-called Kubas interaction between hydrogen molecules and transition metal atoms. It will be demonstrated that the maximum H2 gravimetric capacity can be improved to more than 7.5 wt % by using longer linkers with more ring structures. However, the maximum H2 volumetric capacity can be tuned to more than 70 g/L by varying the size of silsesquioxane cages. We are optimistic that by varying the building blocks, POSS frameworks can be modified to meet the targets for the gravimetric and volumetric capacities set by the U.S. Department of Energy.

  20. Solid Precipitation Measurement Intercomparison in Bismarck, North Dakota, from 1988 through 1997

    Science.gov (United States)

    Ryberg, Karen R.; Emerson, Douglas G.; Macek-Rowland, Kathleen M.

    2009-01-01

    A solid precipitation measurement intercomparison was recommended by the World Meteorological Organization (WMO) and was initiated after approval by the ninth session of the Commission for Instruments and Methods of Observation. The goal of the intercomparison was to assess national methods of measuring solid precipitation against methods whose accuracy and reliability were known. A field study was started in Bismarck, N. Dak., during the 1988-89 winter as part of the intercomparison. The last official field season of the WMO intercomparison was 1992-93; however, the Bismarck site continued to operate through the winter of 1996-97. Precipitation events at Bismarck were categorized as snow, mixed, or rain on the basis of descriptive notes recorded as part of the solid precipitation intercomparison. The rain events were not further analyzed in this study. Catch ratios (CRs) - the ratio of the precipitation catch at each gage to the true precipitation measurement (the corrected double fence intercomparison reference) - were calculated. Then, regression analysis was used to develop equations that model the snow and mixed precipitation CRs at each gage as functions of wind speed and temperature. Wind speed at the gages, functions of temperature, and upper air conditions (wind speed and air temperature at 700 millibars pressure) were used as possible explanatory variables in the multiple regression analysis done for this study. The CRs were modeled by using multiple regression analysis for the Tretyakov gage, national shielded gage, national unshielded gage, AeroChem gage, national gage with double fence, and national gage with Wyoming windshield. As in earlier studies by the WMO, wind speed and air temperature were found to influence the CR of the Tretyakov gage. However, in this study, the temperature variable represented the average upper air temperature over the duration of the event. The WMO did not use upper air conditions in its analysis. The national shielded and

  1. Regional Bias of Satellite Precipitation Estimates

    Science.gov (United States)

    Modrick, T. M.; Georgakakos, K. P.; Spencer, C. R.

    2012-12-01

    Satellite-based estimates of precipitation have improved the spatial availability of precipitation data particularly for regions with limited gauge networks due to limited accessibility or infrastructure. Understanding the quality and reliability of satellite precipitation estimates is important, especially when the estimates are utilitized for real-time hydrologic forecasting and for fast-responding phenomena. In partnership with the World Meteorological Organization (WMO), the U.S. Agency of International Development (USAID) and the National Ocean and Atmospheric Administration (NOAA), the Hydrologic Research Center has begun implementation of real-time flash flood warning systems for diverse regions around the world. As part of this effort, bias characteristics of satellite precipitation have been examined in these various regions, such includes portions of Southeastern Asia, Southeastern Europe, the Middle East, Central America, and the southern half of the African continent. The work has focused on the Global Hydro-Estimator (GHE) precipitation product from NOAA/NESDIS. These real-time systems utilize the GHE given low latency times of this product. This presentation focuses on the characterization of precipitation bias as compared to in-situ gauge records, and the regional variations or similarities. Additional analysis is currently underway considering regional bias for other satellite precipitation products (e.g., CMORPH) for comparison with the GHE results.

  2. The Simulation of High Reynolds Number Cavity Flow Based on Fractional Volumetric Lattice Boltzmann Method

    Institute of Scientific and Technical Information of China (English)

    HAN Shan-ling; ZHU Ping; LIN Zhong-qin

    2005-01-01

    The fractional volumetric lattice Boltzmann method with much better stability was used to simulate two dimensional cavity flows. Because the effective viscosity was reduced by the fraction factor, it is very effective forsimulating high Reynolds number flows. Simulations were carried out on a uniform grids system. The stream lines and the velocity profiles obtained from the simulations agree well with the standard lattice Boltzmann method simulations. Comparisons of detailed flow patterns with other studies via location of vortex centers are also satisfactory.

  3. Theoretical and Experimental Estimations of Volumetric Inductive Phase Shift in Breast Cancer Tissue

    Science.gov (United States)

    González, C. A.; Lozano, L. M.; Uscanga, M. C.; Silva, J. G.; Polo, S. M.

    2013-04-01

    Impedance measurements based on magnetic induction for breast cancer detection has been proposed in some studies. This study evaluates theoretical and experimentally the use of a non-invasive technique based on magnetic induction for detection of patho-physiological conditions in breast cancer tissue associated to its volumetric electrical conductivity changes through inductive phase shift measurements. An induction coils-breast 3D pixel model was designed and tested. The model involves two circular coils coaxially centered and a human breast volume centrally placed with respect to the coils. A time-harmonic numerical simulation study addressed the effects of frequency-dependent electrical properties of tumoral tissue on the volumetric inductive phase shift of the breast model measured with the circular coils as inductor and sensor elements. Experimentally; five female volunteer patients with infiltrating ductal carcinoma previously diagnosed by the radiology and oncology departments of the Specialty Clinic for Women of the Mexican Army were measured by an experimental inductive spectrometer and the use of an ergonomic inductor-sensor coil designed to estimate the volumetric inductive phase shift in human breast tissue. Theoretical and experimental inductive phase shift estimations were developed at four frequencies: 0.01, 0.1, 1 and 10 MHz. The theoretical estimations were qualitatively in agreement with the experimental findings. Important increments in volumetric inductive phase shift measurements were evident at 0.01MHz in theoretical and experimental observations. The results suggest that the tested technique has the potential to detect pathological conditions in breast tissue associated to cancer by non-invasive monitoring. Further complementary studies are warranted to confirm the observations.

  4. Optimization of element length for imaging small volumetric reflectors with linear ultrasonic arrays

    OpenAIRE

    Barber, T. S.; Wilcox, P. D.; Nixon, A. D.

    2016-01-01

    A 3D ultrasonic simulation study is presented, aimed at understanding the effect of element length for imaging small volumetric flaws with linear arrays in ultrasonically noisy materials. The geometry of a linear array can be described by the width, pitch and total number of the elements along with the length perpendicular to imaging plane. This paper is concerned with the latter parameter, which tends to be ignored in array optimization studies and is often chosen arbitrarily for industrial ...

  5. Development of Mathematical Models for Detecting Micron Scale Volumetric Defects in Thin Film Coatings

    Directory of Open Access Journals (Sweden)

    Gaigals G.

    2016-04-01

    Full Text Available The focus of the present research is to investigate possibilities of volumetric defect detection in thin film coatings on glass substrates by means of high definition imaging with no complex optical systems, such as lenses, and to determine development and construction feasibility of a defectoscope employing the investigated methods. Numerical simulations were used to test the proposed methods. Three theoretical models providing various degrees of accuracy and feasibility were studied.

  6. Simultaneously high gravimetric and volumetric methane uptake characteristics of the metal-organic framework NU-111.

    Science.gov (United States)

    Peng, Yang; Srinivas, Gadipelli; Wilmer, Christopher E; Eryazici, Ibrahim; Snurr, Randall Q; Hupp, Joseph T; Yildirim, Taner; Farha, Omar K

    2013-04-14

    We show that the MOF NU-111 exhibits equally high volumetric and gravimetric methane uptake values, both within ≈75% of the DOE targets at 300 K. Upon reducing the temperature to 270 K, the uptake increases to 0.5 g g(-1) and 284 cc(STP) per cc at 65 bar. Adsorption of CO2 and H2 is also reported. Simulated isotherms are in excellent agreement with those obtained from experiments.

  7. 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.

  8. A multistage volumetric bar chart chip for visualized quantification of DNA

    OpenAIRE

    Song, Yujun; Wang, Yuanchen; Qin, Lidong

    2013-01-01

    Nucleic acid detection is critical in disease diagnosis as well as in the environmental assays of harmful bacteria or viruses and forensic applications. Current methods for visualized quantification of DNA require costly and sophisticated instruments. Here, we report a multistage propelled volumetric bar chart chip (MV-Chip) for multiplexing and quantitative detection of DNA. Owing to its ‘rocket-like’ propelling reaction, the pre-deposited platinum films could perform cascade amplification a...

  9. Impact of turbocharger non-adiabatic operation on engine volumetric efficiency and turbo lag

    OpenAIRE

    S. Shaaban; Seume, J.

    2012-01-01

    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 prese...

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

    OpenAIRE

    S. Shaaban; Seume, J.

    2012-01-01

    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 prese...

  11. 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

  12. An Autologous Muscle Tissue Expansion Approach for the Treatment of Volumetric Muscle Loss

    Science.gov (United States)

    2015-07-01

    ORIGINAL RESEARCH ARTICLE Open Access An Autologous Muscle Tissue Expansion Approach for the Treatment of Volumetric Muscle Loss Catherine L. Ward...regeneration. But they require ample donor muscle tissue and therefore may be limited in their application for large clinical VML. Here, we tested the...autologous minced grafts for the regeneration of muscle tissue after VML, but indicate the need to identify optimal carrier materials for expansion

  13. Water content influence on thermal and volumetric properties of wheat starch gelatinization under 10 MPa.

    Science.gov (United States)

    Orlowska, Marta; Randzio, Stanislaw L

    2010-02-01

    A transitiometric in situ analysis of wheat starch aqueous suspensions heated over a temperature range from 285 K to 415 K under isobaric conditions of 10 MPa is presented. Measurements were performed at four selected water concentrations: 56.0%, 64.7%, 73.5%, and 82.4% weight/water. Thermal and volumetric properties and their water content dependencies have been determined for three successive starch phase transformations occurred during wheat starch gelatinization.

  14. Volumetric and superficial characterization of carbon activated; Caracterizacion volumetrica y superficial de carbon activado

    Energy Technology Data Exchange (ETDEWEB)

    Carrera G, L.M.; Garcia S, I.; Jimenez B, J.; Solache R, M.; Lopez M, B.; Bulbulian G, S.; Olguin G, M.T. [Departamento de Quimica, Gerencia de Ciencias Basicas, Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    2000-07-01

    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)

  15. The diagnostic contribution of CT volumetric rendering techniques in routine practice

    OpenAIRE

    Perandini Simone; Faccioli N; Zaccarella A; Re T; Mucelli R

    2010-01-01

    Computed tomography (CT) volumetric rendering techniques such as maximum intensity projection (MIP), minimum intensity projection (MinIP), shaded surface display (SSD), volume rendering (VR), and virtual endoscopy (VE) provide added diagnostic capabilities. The diagnostic value of such reconstruction techniques is well documented in literature. These techniques permit the exploration of fine anatomical detail that would be difficult to evaluate using axial reconstructions alone. Although thes...

  16. A new laboratory-scale experimental facility for detailed aerothermal characterizations of volumetric absorbers

    Science.gov (United States)

    Gomez-Garcia, Fabrisio; Santiago, Sergio; Luque, Salvador; Romero, Manuel; Gonzalez-Aguilar, Jose

    2016-05-01

    This paper describes a new modular laboratory-scale experimental facility that was designed to conduct detailed aerothermal characterizations of volumetric absorbers for use in concentrating solar power plants. Absorbers are generally considered to be the element with the highest potential for efficiency gains in solar thermal energy systems. The configu-ration of volumetric absorbers enables concentrated solar radiation to penetrate deep into their solid structure, where it is progressively absorbed, prior to being transferred by convection to a working fluid flowing through the structure. Current design trends towards higher absorber outlet temperatures have led to the use of complex intricate geometries in novel ceramic and metallic elements to maximize the temperature deep inside the structure (thus reducing thermal emission losses at the front surface and increasing efficiency). Although numerical models simulate the conjugate heat transfer mechanisms along volumetric absorbers, they lack, in many cases, the accuracy that is required for precise aerothermal validations. The present work aims to aid this objective by the design, development, commissioning and operation of a new experimental facility which consists of a 7 kWe (1.2 kWth) high flux solar simulator, a radiation homogenizer, inlet and outlet collector modules and a working section that can accommodate volumetric absorbers up to 80 mm × 80 mm in cross-sectional area. Experimental measurements conducted in the facility include absorber solid temperature distributions along its depth, inlet and outlet air temperatures, air mass flow rate and pressure drop, incident radiative heat flux, and overall thermal efficiency. In addition, two windows allow for the direct visualization of the front and rear absorber surfaces, thus enabling full-coverage surface temperature measurements by thermal imaging cameras. This paper presents the results from the aerothermal characterization of a siliconized silicon

  17. Comparative analysis of volumetric flow meters used for mass flow estimation in multiphase and multidensity environments

    Science.gov (United States)

    Pedone, Richard; Korman, Valentin; Wiley, John T.

    2006-05-01

    Accurate and reliable multiphase flow measurements are needed for liquid propulsion systems. Existing volumetric flow meters are adequate for flow measurements with well-characterized, clean liquids and gases. However, these technologies are inadequate for multiphase environments, such as cryogenic fluids. Although, properly calibrated turbine flow meters can provide highly accurate and repeatable data, problems are still prevalent with multiphase flows. Limitations are thus placed on the applicability of intrusive turbine flow meters.

  18. A substorm in midnight auroral precipitation

    Directory of Open Access Journals (Sweden)

    V. G. Vorobjev

    Full Text Available DMSP F7 spacecraft observations for the whole of 1986 were used to construct the empirical model of the midnight auroral precipitation during a substorm. The model includes the dynamics of different auroral precipitation boundaries and simultaneous changes in average electron precipitation energy and energy flux in different precipitation regions during all substorm phases, as well as the IMF and solar wind plasma signatures during a substorm. The analysis of the model shows a few important features of precipitation. (1 During the magnetic quietness and just before the beginning of the substorm expansive phase the latitudinal width of the auroral precipitation in the nightside sector is about 5 – 6° CGL, while that of the auroral oval is about 2 – 3° CGL during such periods. (2 For about 5 min before the substorm onset a decrease in the average precipitating electron energy in the equatorward part of auroral zone was observed simultaneously, with an increase in both the average electron energy and energy flux of electron precipitation in the poleward part of the auroral zone. (3 The isotropy boundary position in the beginning of the substorm expansive phase coincides well with the inner edge of the central plasma sheet. The analysis of interplanetary medium parameters shows that, on average, during the substorm development, the solar wind dynamic pressure was about 1.5 times that of the magnetic quietness period. Substorms occurred predominantly during the southward IMF orientation, suggesting that substorm onset often was not associated with the northern turn or decrease in the southward interplanetary Bz . The Northern Hemisphere’s substorms occurred generally during the positive interplanetary By in winter, and they were observed when the interplanetary By was negative in summer.

    Key words. Ionosphere (auroral ionosphere; particle precipitation – Magnetospheric physics

  19. Layered double hydroxides as containers of inhibitors in organic coatings for corrosion protection of carbon steel

    OpenAIRE

    Hang, To Thi Xuan; Truc, Trinh Anh; Duong, Nguyen Thuy; Pébère, Nadine; Olivier, Marie-Georges

    2012-01-01

    International audience; The present work focuses on the use of layered double hydroxides (LDH) as containers for corrosion inhibitors in an epoxy coating. 2-Benzothiazolylthio-succinic acid (BTSA), used as corrosion inhibitor, was intercalated by co-precipitation in magnesium-aluminum layered double hydroxides. The obtained LDH-BTSA was characterized by infrared spectroscopy, X-ray diffraction and scanning electron microscopy. BTSA release from LDH-BTSA in NaCl solutions was investigated by U...

  20. Scales of Topographic Dependence of Alpine Precipitation

    Science.gov (United States)

    Hutchinson, M. F.

    2002-12-01

    Scales of topographic dependence of daily precipitation over the Swiss Alps are examined using a new multivariate precipitation interpolation technique. The method of additive regression splines has been designed to incorporate spatially varying dependences on several topographic variables. It avoids the "curse of dimension" by restricting the underlying spline structure to be two-dimensional. This is in keeping with the overall goal of delivering essentially two-dimensional maps. Moreover, it permits a separation between physical process, as represented by various topographic variables, and the empirically determined, continuous two-dimensional effects of these variables on precipitation across the landscape. The analysis determines horizontal and vertical scales of the interaction of precipitation with topography. A common limitation with existing precipitation interpolation methods lies in their difficulty in identifying effective topographic parameters other than elevation. Orographic effects associated with slope and aspect are often discussed but are not always statistically significant. The effects of two topographic parameters, the northern and eastern components of the unit normal to an appropriately vertically exaggerated digital elevation model, are investigated. These parameters have some basis in process modelling studies and, unlike topographic aspect, are continuous functions of horizontal position. They are used to identify significant topographic aspect effects on precipitation without prior knowledge of the prevailing wind field. Short range correlation structure has rarely been explicitly identified in precipitation interpolation studies but its impact is surprisingly strong. Evidence for its existence in these precipitation data was provided in an earlier study but effective methods for calibrating such correlation in spline analyses have only recently been developed. The spatial scale of correlation found here, around 5 km, is large enough to

  1. Template-assisted low temperature synthesis of functionalized graphene for ultrahigh volumetric performance supercapacitors.

    Science.gov (United States)

    Yan, Jun; Wang, Qian; Wei, Tong; Jiang, Lili; Zhang, Milin; Jing, Xiaoyan; Fan, Zhuangjun

    2014-05-27

    We demonstrated the fabrication of functionalized graphene nanosheets via low temperature (300 °C) treatment of graphite oxide with a slow heating rate using Mg(OH)2 nanosheets as template. Because of its dented sheet with high surface area, a certain amount of oxygen-containing groups, and low pore volume, the as-obtained graphene delivers both ultrahigh specific gravimetric and volumetric capacitances of 456 F g(-1) and 470 F cm(-3), almost 3.7 times and 3.3 times higher than hydrazine reduced graphene, respectively. Especially, the obtained volumetric capacitance is the highest value so far reported for carbon materials in aqueous electrolytes. More importantly, the assembled supercapacitor exhibits an ultrahigh volumetric energy density of 27.2 Wh L(-1), which is among the highest values for carbon materials in aqueous electrolytes, as well as excellent cycling stability with 134% of its initial capacitance after 10,000 cycles. Therefore, the present work holds a great promise for future design and large-scale production of high performance graphene electrodes for portable energy storage devices.

  2. The prognostic role of prenatal MRI volumetric assessment in fetuses with isolated ventriculomegaly.

    Science.gov (United States)

    Gezer, Naciye Sinem; Güleryüz, Handan; Gezer, Cenk; Koçyiğit, Ali; Yeşilırmak, Didem; Ekin, Atalay; Bilgin, Muzaffer; Ertaş, İbrahim Egemen

    2015-01-01

    In this prospective study, we aimed to establish the value of volumetric assessment by prenatal brain MRI in determining the prognosis of fetuses with isolated VM. A total of 23 fetuses with isolated VM were included in the study. Supratentorial cerebral parenchyma volume (PV) and ventricular volume (VV) were measured, and supratentorial ventricular/parenchymal volume (VV/PV) ratios were calculated. Pregnancy and postnatal neurodevelopmental outcomes up to two years of age were obtained and correlated with the volumetric measurements. VV was found to be strongly and positively correlated with ventricular dimension. There was a statistically significant difference between the VV/ PV ratios of the good and poor prognosis groups into which the cases had been categorized. The fetuses with a poor prognosis had a significantly higher VV/PV ratio. Volumetric parenchymal and ventricular measurements obtained by fetal brain MRI may contribute to future clinical studies concerning the evaluation of fetuses with VM and provide an important indicator in cases where management dilemmas arise.

  3. The effect of volumetric (3D) tactile symbols within inclusive tactile maps.

    Science.gov (United States)

    Gual, Jaume; Puyuelo, Marina; Lloveras, Joaquim

    2015-05-01

    Point, linear and areal elements, which are two-dimensional and of a graphic nature, are the morphological elements employed when designing tactile maps and symbols for visually impaired users. However, beyond the two-dimensional domain, there is a fourth group of elements - volumetric elements - which mapmakers do not take sufficiently into account when it comes to designing tactile maps and symbols. This study analyses the effect of including volumetric, or 3D, symbols within a tactile map. In order to do so, the researchers compared two tactile maps. One of them uses only two-dimensional elements and is produced using thermoforming, one of the most popular systems in this field, while the other includes volumetric symbols, thus highlighting the possibilities opened up by 3D printing, a new area of production. The results of the study show that including 3D symbols improves the efficiency and autonomous use of these products. Copyright © 2014 Elsevier Ltd and The Ergonomics Society. All rights reserved.

  4. [Change in condylar and mandibular morphology in juvenile idiopathic arthritis: cone beam volumetric imaging].

    Science.gov (United States)

    Garagiola, Umberto; Mercatali, Lorenzo; Bellintani, Claudio; Fodor, Attila; Farronato, Giampietro; Lőrincz, Adám

    2013-03-01

    The aim of this study is to show the importance of Cone Beam Computerized Tomography to volumetrically quantify TMJ damage in patients with JIA, measuring condylar and mandibular real volumes. 34 children with temporomandibular involvement by Juvenile Idiopathic Arthritis were observed by Cone Beam Computerized Tomography. 4 were excluded because of several imaging noises. The mandible was isolated from others craniofacial structures; the whole mandibular volume and its components' volumes (condyle, ramus, hemibody, hemisymphysis on right side and on left side) has been calculated by a 3D volume rendering technique. The results show a highly significant statistical difference between affected side volumetric values versus normal side volumetric values above all on condyle region (P < 0.01), while they don't show any statistical differences between right side versus left side. The Cone Beam Computerized Tomography represents a huge improvement in understanding of the condyle and mandibular morphological changes, even in the early stages of the Juvenile Idiopathic Arthritis. The JIA can lead in children to temporomandibular joint damage with facial development and growth alterations.

  5. 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

    Background 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. Objectives 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. Methods 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. Results 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). Conclusion 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. PMID:27557088

  6. 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.

  7. 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.

  8. Brain stem and cerebellum volumetric analysis of Machado Joseph disease patients

    Directory of Open Access Journals (Sweden)

    S T Camargos

    2011-01-01

    Full Text Available Machado-Joseph disease, or spinocerebellar ataxia type 3(MJD/SCA3, is the most frequent late onset spinocerebellar ataxia and results from a CAG repeat expansion in the ataxin-3 gene. Previous studies have found correlation between atrophy of cerebellum and brainstem with age and CAG repeats, although no such correlation has been found with disease duration and clinical manifestations. In this study we test the hypothesis that atrophy of cerebellum and brainstem in MJD/SCA3 is related to clinical severity, disease duration and CAG repeat length as well as to other variables such as age and ICARS (International Cooperative Ataxia Rating Scale. Whole brain high resolution MRI and volumetric measurement with cranial volume normalization were obtained from 15 MJD/SCA3 patients and 15 normal, age and sex-matchedcontrols. We applied ICARS and compared the score with volumes and CAG number, disease duration and age. We found significant correlation of both brain stem and cerebellar atrophy with CAG repeat length, age, disease duration and degree of disability. The Spearman rank correlation was stronger with volumetric reduction of the cerebellum than with brain stem. Our data allow us to conclude that volumetric analysis might reveal progressive degeneration after disease onset, which in turn is linked to both age and number of CAG repeat expansions in SCA 3.

  9. Volumetric flow rate comparisons for water and product on pasteurization systems.

    Science.gov (United States)

    Schlesser, J E; Stroup, W H; McKinstry, J A

    1994-04-01

    A flow calibration tube system was assembled to determine the volumetric flow rates for water and various dairy products through a holding tube, using three different flow promotion methods. With the homogenizer, the volumetric flow rates of water and reconstituted skim milk were within 1.5% of each other. With the positive displacement pump, the flow rate for reconstituted skim milk increased compared with that for water as the pressure increased or temperature decreased. The largest increase in flow rate was at 310-kPa gauge and 20 degrees C. On a magnetic flow meter system, the volumetric flow rates of water and reconstituted skim milk were within .5% of the flow rate measured from the volume collected in a calibrated tank. The flow rate of whole milk was similar to that of skim milk on the three flow promoters evaluated. Ice milk mix increased the flow rate of the positive displacement pump, but not the homogenizer and magnetic flow meter system.

  10. 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.

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

    DEFF Research Database (Denmark)

    Naveed, Muhammad; Møldrup, Per; Tuller, Markus

    (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......F value. Hereby, the Xw*-model implicitly assumes that a given particle size fraction creates an analogue pore size fraction and, also, is based on the validity of the well-known capillary law equation relating equivalent drained pore size to the soil-water matric potential. The Xw*-model was found...... 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...

  12. Improving reservoir volumetric estimations in petroleum resource assessment using discovery process models

    Institute of Scientific and Technical Information of China (English)

    Chen Zhuoheng; Osadetz Kirk G.

    2009-01-01

    The reservoir volumetric approach represents a widely accepted, but flawed method of petroleum play resource calculation.In this paper, we propose a combination of techniques that can improve the applicability and quality of the resource estimation.These techniques include: 1) the use of the Multivariate Discovery Process model (MDP) to derive unbiased distribution parameters of reservoir volumetric variables and to reveal correlations among the variables; 2) the use of the Geo-anchored method to estimate simultaneously the number of oil and gas pools in the same play; and 3) the cross-validation of assessment results from different methods.These techniques are illustrated by using an example of crude oil and natural gas resource assessment of the Sverdrup Basin, Canadian Archipelago.The example shows that when direct volumetric measurements of the untested prospects are not available, the MDP model can help derive unbiased estimates of the distribution parameters by using information from the discovered oil and gas accumulations.It also shows that an estimation of the number of oil and gas accumulations and associated size ranges from a discovery process model can provide an alternative and efficient approach when inadequate geological data hinder the estimation.Cross-examination of assessment results derived using different methods allows one to focus on and analyze the causes for the major differences, thus providing a more reliable assessment outcome.

  13. 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.

  14. Volumetric dimensional changes of dental light-cured dimethacrylate resins after sorption of water or ethanol.

    Science.gov (United States)

    Sideridou, Irini D; Karabela, Maria M; Vouvoudi, Evagelia Ch

    2008-08-01

    This study evaluated the influence of water and ethanol sorption on the volumetric dimensional changes of resins prepared by light curing of Bis-GMA, Bis-EMA, UDMA, TEGDMA or D(3)MA. The resin specimens (15mm diameterx1mm height) were immersed in water or ethanol 37+/-1 degrees C for 30 days. Volumetric changes of specimens were obtained via accurate mass measurements using Archimedes principle. The specimens were reconditioned by dry storage in an oven at 37+/-1 degrees C until constant mass was obtained and then immersed in water or ethanol for 30 days. The volumetric changes of specimens were determined and compared to those obtained from the first sorption. Resins showed similar volume increase during the first and second sorptions of water or ethanol. The volume increase due to water absorption is in the following order: poly-TEGDMA>poly-Bis-GMA>poly-UDMA>poly-Bis-EMA>poly-D(3)MA. On the contrary, the order in ethanol is poly-Bis-GMA>poly-UDMA>poly-TEGDMA>poly-Bis-EMA approximately poly-D(3)MA. The volume increase was found to depend linearly on the amount of water or ethanol absorbed. In the choice of monomers for preparation of composite resin matrix the volume increase in the resin after immersion in water or ethanol must be taken into account. Resins of Bis-EMA and D(3)MA showed the lowest values.

  15. Three-dimensional linear and volumetric analysis of maxillary sinus pneumatization

    Directory of Open Access Journals (Sweden)

    Reham M. Hamdy

    2014-05-01

    Full Text Available Considering the anatomical variability related to the maxillary sinus, its intimate relation to the maxillary posterior teeth and because of all the implications that pneumatization may possess, three-dimensional assessment of maxillary sinus pneumatization is of most usefulness. The aim of this study is to analyze the maxillary sinus dimensions both linearly and volumetrically using cone beam computed tomography (CBCT to assess the maxillary sinus pneumatization. Retrospective analysis of 30 maxillary sinuses belonging to 15 patients’ CBCT scans was performed. Linear and volumetric measurements were conducted and statistically analyzed. The maximum craniocaudal extension of the maxillary sinus was located around the 2nd molar in 93% of the sinuses, while the maximum mediolateral and antroposterior extensions of the maxillary sinus were located at the level of root of zygomatic complex in 90% of sinuses. There was a high correlation between the linear measurements of the right and left sides, where the antroposterior extension of the sinus at level of the nasal floor had the largest correlation (0.89. There was also a high correlation between the Simplant and geometric derived maxillary sinus volumes for both right and left sides (0.98 and 0.96, respectively. The relations of the sinus floor can be accurately assessed on the different orthogonal images obtained through 3D CBCT scan. The geometric method offered a much cheaper, easier, and less sophisticated substitute; therefore, with the availability of software, 3D volumetric measurements are more facilitated.

  16. Dental volumetric tomographical evaluation of location and prevalence of maxillary sinus septa

    Directory of Open Access Journals (Sweden)

    Ibrahim Damlar

    2013-06-01

    Full Text Available Purpose: The aim of this study was to determine the prevalence and location of maxillary sinus septa with the help of dental volumetric tomography. Methods: 760 patients’ 1520 maxillary sinus were evaluated by dental volumetric tomography for detecting maxillary sinus septa. Maxillary sinus was divided into 3 zones (anterior, middle and posterior zones while location of the maxillary sinus septa. Results: 47 of maxillary sinus septa existed in the anterior zone (24.7%, 35 of them in the middle zone (18.4% and 108 of them in the posterior region (56.8%. Conclusion: The formation of the maxillary sinus septa was affected by the existence or lack of the teeth. Correct detection of the presence of maxillary sinus septa was important prior to sinus lifting and dental implant surgery. Dental volumetric tomographical evaluation of maxillary sinus septa was more useful for a correct diagnosis and treatment planning. [Cukurova Med J 2013; 38(3.000: 467-474

  17. A new contrast-assisted method in microcirculation volumetric flow assessment

    Science.gov (United States)

    Lu, Sheng-Yi; Chen, Yung-Sheng; Yeh, Chih-Kuang

    2007-03-01

    Microcirculation volumetric flow rate is a significant index in diseases diagnosis and treatment such as diabetes and cancer. In this study, we propose an integrated algorithm to assess microcirculation volumetric flow rate including estimation of blood perfused area and corresponding flow velocity maps based on high frequency destruction/contrast replenishment imaging technique. The perfused area indicates the blood flow regions including capillaries, arterioles and venules. Due to the echo variance changes between ultrasonic contrast agents (UCAs) pre- and post-destruction two images, the perfused area can be estimated by the correlation-based approach. The flow velocity distribution within the perfused area can be estimated by refilling time-intensity curves (TICs) after UCAs destruction. Most studies introduced the rising exponential model proposed by Wei (1998) to fit the TICs. Nevertheless, we found the TICs profile has a great resemblance to sigmoid function in simulations and in vitro experiments results. Good fitting correlation reveals that sigmoid model was more close to actual fact in describing destruction/contrast replenishment phenomenon. We derived that the saddle point of sigmoid model is proportional to blood flow velocity. A strong linear relationship (R = 0.97) between the actual flow velocities (0.4-2.1 mm/s) and the estimated saddle constants was found in M-mode and B-mode flow phantom experiments. Potential applications of this technique include high-resolution volumetric flow rate assessment in small animal tumor and the evaluation of superficial vasculature in clinical studies.

  18. 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.

  19. Fatigue life estimation for different notched specimens based on the volumetric approach

    Directory of Open Access Journals (Sweden)

    Esmaeili F.

    2010-06-01

    Full Text Available In this paper, the effects of notch radius for different notched specimens has been studied on the values of stress concentration factor, notch strength reduction factor, and fatigue life duration of the specimens. The material which has been selected for this investigation is Al 2024T3 . Volumetric approach has been applied to obtain the values of notch strength reduction factor and results have been compared with those obtained from the Neuber and Peterson methods. Load controlled fatigue tests of mentioned specimens have been conducted on the 250kN servo-hydraulic Zwick/Amsler fatigue testing machine with the frequency of 10Hz. The fatigue lives of the specimens have also been predicted based on the available smooth S-N curve of Al2024-T3 and also the amounts of notch strength reduction factor which have been obtained from volumetric, Neuber and Peterson methods. The values of stress and strain around the notch roots are required to predict the fatigue life of notched specimens, so Ansys finite element code has been used and non-linear analyses have been performed to obtain the stress and strain distributions around the notches. The plastic deformations of the material have been simulated using multi-linear kinematic hardening and cyclic stress-strain relation. The work here shows that the volumetric approach does a very good job for predicting the fatigue life of the notched specimens.

  20. A New Method for Near Real Time Precipitation Estimates Using a Derived Statistical Relationship between Precipitable Water Vapor and Precipitation

    Science.gov (United States)

    Roman, J.

    2015-12-01

    The IPCC 5th Assessment found that the predicted warming of 1oC would increase the risk of extreme events such as heat waves, droughts, and floods. Weather extremes, like floods, have shown the vulnerability and susceptibility society has to these extreme weather events, through impacts such as disruption of food production, water supply, health, and damage of infrastructure. This paper examines a new way of near-real time forecasting of precipitation. A 10-year statistical climatological relationship was derived between precipitable water vapor (PWV) and precipitation by using the NASA Atmospheric Infrared Sounder daily gridded PWV product and the NASA Tropical Rainfall Measuring Mission daily gridded precipitation total. Forecasting precipitation estimates in real time is dire for flood monitoring and disaster management. Near real time PWV observations from AIRS on Aqua are available through the Goddard Earth Sciences Data and Information Service Center. In addition, PWV observations are available through direct broadcast from the NASA Suomi-NPP ATMS/CrIS instrument, the operational follow on to AIRS. The derived climatological relationship can be applied to create precipitation estimates in near real time by utilizing the direct broadcasting capabilities currently available in the CONUS region. The application of this relationship will be characterized through case-studies by using near real-time NASA AIRS Science Team v6 PWV products and ground-based SuomiNet GPS to estimate the current precipitation potential; the max amount of precipitation that can occur based on the moisture availability. Furthermore, the potential contribution of using the direct broadcasting of the NUCAPS ATMS/CrIS PWV products will be demonstrated. The analysis will highlight the advantages of applying this relationship in near-real time for flash flood monitoring and risk management. Relevance to the NWS River Forecast Centers will be discussed.

  1. USING COLLOIDAL LAYERED DOUBLE HYDROXIDES AS CATIONICMICROPARTICULATE COMPONENT

    Institute of Scientific and Technical Information of China (English)

    SonglinWang; WenxiaLiu

    2004-01-01

    Layered double hydroxides consisting of layers withcationic charges may be potential candidates ofcationic microparticles forming synergetic retentioneffect with anionic polyacrylamide. In this work, thelayered double hydroxides with various molar ratiosof Mg/AI were synthesized by co-precipitation ofmagnesium chloride and aluminum chloride and pep-tized by intense washing with water. The chemicalformula, particle size, Zeta potential of the layereddouble hydroxide were analyzed. It was found thatpositively charged magnesium aluminum hydroxidewith particle diameter in nanoparticle size could beprepared. The Zeta potential and particle size varywith the feed molar ratio of Mg/A1 and the peptizingprocess, respectively. The Zeta potential is also pHdependent. The retention experiments carried out onDDJ show that when used together with anionic poly-acrylamide, the positively charged colloidal doublehydroxide greatly improves the retention of reedpulps. The chemical formula, particle size and Zetapotential of the colloidal double hydroxide all affectits retention behavior.

  2. A matterless double slit

    CERN Document Server

    King, B; Keitel, C H; 10.1038/nphoton.2009.261

    2013-01-01

    Double-slits provide incoming photons with a choice. Those that survive the passage have chosen from two possible paths which interfere to distribute them in a wave-like manner. Such wave-particle duality continues to be challenged and investigated in a broad range of disciplines with electrons, neutrons, helium atoms, C60 fullerenes, Bose-Einstein condensates and biological molecules. All variants have hitherto involved material constituents. We present a matterless double-slit scenario in which photons generated from virtual electron-positron pair annihilation in head-on collisions of a probe laser field with two ultra-intense laser beams form a double-slit interference pattern. Such electromagnetic fields are predicted to induce material-like behaviour in the vacuum, supporting elastic scattering between photons. Our double-slit scenario presents on the one hand a realisable method to observe photon-photon scattering, and demonstrates on the other, the possibility of both controlling light with light and n...

  3. The Double Nine Festival

    Institute of Scientific and Technical Information of China (English)

    1993-01-01

    THE Double Nine Festival,which falls on theninth day of the ninth lunar month,is anancient tradition among Han Chinese.TheBook of Changes,a famous classic in ancient China,designates the number 9 as yang(the masculine orpositive principle in nature).Thus Double Nine isknown as Chongyang in Chinese,meaning doubleyang.In The Western Capital Miscellancy,Ge Hong(281-341)of the Eastern Jin Dynasty described onetraditional custom of the Western Han Dynasty (206B.C.-A.D.24):″Wearing medicinal comel (Cornusofficinalis),eating double yang cake and drinking chry-santhemum wine on the ninth day of the ninth lunarmonth all help to prolong life.″Therefore the DoubleNine Festival is also celebrated as a festival for the old.People often wear medicinal cornel and climb to ahigh place to drink chrysanthemum wine.The customcomes from a legend:Huan Jing was a student ofnecromancer Fei Changfang in the Eastern Han Dy-nasty (25-220). One day Fei warned Huan that thelatter’s family was in danger of suffering a diaster ont

  4. Chaotic period doubling

    NARCIS (Netherlands)

    Chandramouli, V. V. M. S.; Martens, M.; De Melo, W.; Tresser, C. P.

    2009-01-01

    The period doubling renormalization operator was introduced by Feigenbaum and by Coullet and Tresser in the 1970s to study the asymptotic small-scale geometry of the attractor of one-dimensional systems that are at the transition from simple to chaotic dynamics. This geometry turns out not to depend

  5. Aristotle and Double Effect

    DEFF Research Database (Denmark)

    Di Nucci, Ezio

    2014-01-01

    There are some interesting similarities between Aristotle’s ‘mixed actions’ in Book III of the Nicomachean Ethics and the actions often thought to be justifiable with the Doctrine of Double Effect. Here I analyse these similarities by comparing Aristotle’s examples of mixed actions with standard ...

  6. Recent and future extreme precipitation over Ukraine

    Science.gov (United States)

    Vyshkvarkova, Olena; Voskresenskaya, Elena

    2014-05-01

    The aim of study is to analyze the parameters of precipitation extremes and inequality over Ukraine in recent climate epoch and their possible changes in the future. Data of observations from 28 hydrometeorological stations over Ukraine and output of GFDL-CM3 model (CMIP5) for XXI century were used in the study. The methods of concentration index (J. Martin-Vide, 2004) for the study of precipitation inequality while the extreme precipitation indices recommended by the ETCCDI - for the frequency of events. Results. Precipitation inequality on the annual and seasonal scales was studied using estimated CI series for 1951-2005. It was found that annual CI ranges vary from 0.58 to 0.64. They increase southward from the north-west (forest zone) and the north-east (forest steppe zone) of Ukraine. CI maxima are located in the coastal regions of the Black Sea and the Sea of Azov. Annual CI spatial distribution indicates that the contribution of extreme precipitation into annual totals is most significant at the boundary zone between steppe and marine regions. At the same time precipitation pattern at the foothill of Carpathian Mountains is more homogenous. The CI minima (0.54) are typical for the winter season in foothill of Ukrainian Carpathians. The CI maxima reach 0.71 in spring at the steppe zone closed to the Black Sea coast. It should be noted that the greatest ranges of CI maximum and CI minimum deviation are typical for spring. It is associated with patterns of cyclone trajectories in that season. The most territory is characterized by tendency to decrease the contribution of extreme precipitation into the total amount (CI linear trends are predominantly negative in all seasons). Decadal and interdecadal variability of precipitation inequality associated with global processes in ocean-atmosphere system are also studied. It was shown that precipitation inequality over Ukraine on 10 - 15 % stronger in negative phase of Pacific Decadal Oscillation and in positive phase

  7. Volumetric-modulated arc therapy vs c-IMRT in esophageal cancer: A treatment planning comparison

    Institute of Scientific and Technical Information of China (English)

    Li Yin; Bo Xu; Guang-Ying Zhu; Hao Wu; Jian Gong; Jian-Hao Geng; Fan Jiang; An-Hui Shi; Rong Yu; Yong-Heng Li; Shu-Kui Han

    2012-01-01

    AIM:To compare the volumetric-modulated arc therapy (VMAT) plans with conventional sliding window intensity-modulated radiotherapy (c-IMRT) plans in esophageal cancer (EC).METHODS:Twenty patients with EC were selected,including 5 cases located in the cervical,the upper,the middle and the lower thorax,respectively.Five plans were generated with the eclipse planning system:three using c-IMRT with 5 fields (5F),7 fields (7F) and 9 fields (9F),and two using VMAT with a single arc (1A) and double arcs (2A).The treatment plans were designed to deliver a dose of 60 Gy to the planning target volume (PTV) with the same constrains in a 2.0 Gy daily fraction,5 d a week.Plans were normalized to 95% of the PTV that received 100% of the prescribed dose.We examined the dose-volume histogram parameters of PTV and the organs at risk (OAR) such as lungs,spinal cord and heart.Monitor units (MU) and normal tissue complication probability (NTCP) of OAR were also reported.RESULTS:Both c-IMRT and VMAT plans resulted in abundant dose coverage of PTV for EC of different locations.The dose conformity to PTV was improved as the number of field in c-IMRT or rotating arc in VMAT was increased.The doses to PTV and OAR in VMAT plans were not statistically different in comparison with c-IMRT plans,with the following exceptions:in cervical and upper thoracic EC,the conformity index (CI) was higher in VMAT (1A 0.78 and 2A 0.8) than in c-IMRT (SF 0.62,7F 0.66 and 9F 0.73) and homogeneity was slightly better in c-IMRT (7F 1.09 and 9F 1.07) than in VMAT (1A 1.1 and 2A 1.09).Lung V30 was lower in VMAT (1A 12.52 and 2A 12.29) than in c-IMRT (7F 14.35 and 9F 14.81).The humeral head doses were significantly increased in VMAT as against c-IMRT.In the middle and lower thoracic EC,CI in VMAT (1A 0.76 and 2A 0.74) was higher than in c-IMRT (5F 0.63 Gy and 7F 0.67 Gy),and homogeneity was almost similar between VMAT and c-IMRT.V20 (2A 21.49 Gy vs 7F 24.59 Gy and 9F 24.16 Gy) and V30 (2A 9.73 Gy vs 5F 12

  8. Volumetric changes of the graft after maxillary sinus floor augmentation with Bio-Oss and autogenous bone in different ratios

    DEFF Research Database (Denmark)

    Jensen, Thomas; Schou, Søren; Svendsen, Patricia Anne

    2012-01-01

    composition was selected at random and placed concomitant with implant placement. Computed tomographies of the maxillary sinuses were obtained preoperatively, immediately postoperatively, and at euthanasia after 12 weeks. The volumetric changes of the graft were estimated using the Cavalieri principle...

  9. Optimal planning strategy among various arc arrangements for prostate stereotactic body radiotherapy with volumetric modulated arc therapy technique

    Directory of Open Access Journals (Sweden)

    Kang Sang Won

    2017-03-01

    Full Text Available The aim of this study was to determine the optimal strategy among various arc arrangements in prostate plans of stereotactic body radiotherapy with volumetric modulated arc therapy (SBRT-VMAT.

  10. Precipitation Recycling and the Vertical Distribution of Local and Remote Sources of Water for Precipitation

    Science.gov (United States)

    Bosilovich, Michael G.; Atlas, Robert (Technical Monitor)

    2002-01-01

    Precipitation recycling is defined as the amount of water that evaporates from a region that precipitates within the same region. This is also interpreted as the local source of water for precipitation. In this study, the local and remote sources of water for precipitation have been diagnosed through the use of passive constituent tracers that represent regional evaporative sources along with their transport and precipitation. We will discuss the differences between this method and the simpler bulk diagnostic approach to precipitation recycling. A summer seasonal simulation has been analyzed for the regional sources of the United States Great Plains precipitation. While the tropical Atlantic Ocean (including the Gulf of Mexico) and the local continental sources of precipitation are most dominant, the vertically integrated column of water contains substantial water content originating from the Northern Pacific Ocean, which is not precipitated. The vertical profiles of regional water sources indicate that local Great Plains source of water dominates the lower troposphere, predominantly in the PBL. However, the Pacific Ocean source is dominant over a large portion of the middle to upper troposphere. The influence of the tropical Atlantic Ocean is reasonably uniform throughout the column. While the results are not unexpected given the formulation of the model's convective parameterization, the analysis provides a quantitative assessment of the impact of local evaporation on the occurrence of convective precipitation in the GCM. Further, these results suggest that local source of water is not well mixed throughout the vertical column.

  11. Fundamental features of copper ion precipitation using sulfide as a precipitant in a wastewater system.

    Science.gov (United States)

    Choi, Jung-Yoon; Kim, Dong-Su; Lim, Joong-Yeon

    2006-01-01

    We have investigated the precipitation features of copper ion using sulfide as a precipitant by varying the mole ratio of sulfide to copper ion, pH, temperature and the kind and concentration of complexing agent. In the precipitation of copper ion by sulfide, sludge is produced as cupric sulfide; thus, there is a possibility for its recycled use in photochemical and ceramic processes. When the ratio of the concentration of copper ion to sulfide was increased to more than 1.0, the extent of precipitation was very high. As the ratio was increased, nucleation time was decreased and crystal growth rate was raised. The higher the pH, the greater the amount of precipitated copper ion due to lowered solubility of cupric sulfide. When temperature changed from 25 degrees C to 55 degrees C, the precipitation of copper ion was increased a little. On the basis of estimated thermodynamic parameters such as Gibbs free energy and enthalpy, the precipitation reaction was spontaneous and endothermic. The precipitation of copper ion was lowered in the presence of complexing agent and it was affected by the stability of the copper complex. The feasibility test for the application of precipitation treatment to actual wastewater containing copper ion showed, although there was a little decrease in the removal of copper, the precipitation extent of copper was higher than 90% compared with that for artificial wastewater.

  12. Volumetric Properties of the Mixture Trichloromethane CHCl3 + C4H10O Diethyl ether (VMSD1211, LB3412_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume C 'Binary Liquid Systems of Nonelectrolytes III' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Trichloromethane CHCl3 + C4H10O Diethyl ether (VMSD1211, LB3412_V)' providing data from direct low-pressure dilatometric measurement of molar excess volume at variable mole fraction and constant temperature.

  13. Volumetric Properties of the Mixture Trichloromethane CHCl3 + C8H16 Cyclooctane (VMSD1211, LB3565_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume B 'Binary Liquid Systems of Nonelectrolytes II' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Trichloromethane CHCl3 + C8H16 Cyclooctane (VMSD1211, LB3565_V)' providing data from direct low-pressure dilatometric measurement of molar excess volume at variable mole fraction and constant temperature.

  14. Volumetric Properties of the Mixture Trichloromethane CHCl3 + C5H10O Oxane (VMSD1212, LB3577_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume C 'Binary Liquid Systems of Nonelectrolytes III' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Trichloromethane CHCl3 + C5H10O Oxane (VMSD1212, LB3577_V)' providing data by calculation of molar excess volume from low-pressure density measurements at variable mole fraction and constant temperature.

  15. Volumetric Properties of the Mixture Trichloromethane CHCl3 + C4H8O Oxolane (VMSD1212, LB3576_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume C 'Binary Liquid Systems of Nonelectrolytes III' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Trichloromethane CHCl3 + C4H8O Oxolane (VMSD1212, LB3576_V)' providing data by calculation of molar excess volume from low-pressure density measurements at variable mole fraction and constant temperature.

  16. Volumetric Properties of the Mixture Trichloromethane CHCl3 + C6H14 Hexane (VMSD1211, LB4339_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume B 'Binary Liquid Systems of Nonelectrolytes II' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Trichloromethane CHCl3 + C6H14 Hexane (VMSD1211, LB4339_V)' providing data from direct low-pressure dilatometric measurement of molar excess volume at variable mole fraction and constant temperature.

  17. Volumetric Properties of the Mixture Trichloromethane CHCl3 + C6H12 Cyclohexane (VMSD1211, LB3566_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume A 'Binary Liquid Systems of Nonelectrolytes I' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Trichloromethane CHCl3 + C6H12 Cyclohexane (VMSD1211, LB3566_V)' providing data from direct low-pressure dilatometric measurement of molar excess volume at variable mole fraction and constant temperature.

  18. Volumetric Properties of the Mixture Trichloromethane CHCl3 + C6H7N Aniline (VMSD1211, LB4340_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume C 'Binary Liquid Systems of Nonelectrolytes III' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Trichloromethane CHCl3 + C6H7N Aniline (VMSD1211, LB4340_V)' providing data from direct low-pressure dilatometric measurement of molar excess volume at variable mole fraction and constant temperature.

  19. Volumetric Properties of the Mixture Trichloromethane CHCl3 + C5H10 Cyclopentane (VMSD1211, LB3567_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume A 'Binary Liquid Systems of Nonelectrolytes I' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Trichloromethane CHCl3 + C5H10 Cyclopentane (VMSD1211, LB3567_V)' providing data from direct low-pressure dilatometric measurement of molar excess volume at variable mole fraction and constant temperature.

  20. Volumetric Properties of the Mixture Trichloromethane CHCl3 + C2H6S 2-Thiapropane (VMSD1211, LB3233_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume C 'Binary Liquid Systems of Nonelectrolytes III' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Trichloromethane CHCl3 + C2H6S 2-Thiapropane (VMSD1211, LB3233_V)' providing data from direct low-pressure dilatometric measurement of molar excess volume at variable mole fraction and constant temperature.

  1. Volumetric Properties of the Mixture Trichloromethane CHCl3 + C2H6OS Dimethyl sulfoxide (VMSD1211, LB3256_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume C 'Binary Liquid Systems of Nonelectrolytes III' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Trichloromethane CHCl3 + C2H6OS Dimethyl sulfoxide (VMSD1211, LB3256_V)' providing data from direct low-pressure dilatometric measurement of molar excess volume at variable mole fraction and constant temperature.

  2. Volumetric Properties of the Mixture Trichloromethane CHCl3 + CH2Cl2 Dichloromethane (VMSD1212, LB4574_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume A 'Binary Liquid Systems of Nonelectrolytes I' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Trichloromethane CHCl3 + CH2Cl2 Dichloromethane (VMSD1212, LB4574_V)' providing data by calculation of molar excess volume from low-pressure density measurements at variable mole fraction and constant temperature.

  3. Volumetric Properties of the Mixture Trichloromethane CHCl3 + C6H6 Benzene (VMSD1212, LB3207_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume A 'Binary Liquid Systems of Nonelectrolytes I' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Trichloromethane CHCl3 + C6H6 Benzene (VMSD1212, LB3207_V)' providing data by calculation of molar excess volume from low-pressure density measurements at variable mole fraction and constant temperature.

  4. Volumetric Properties of the Mixture Trichloromethane CHCl3 + C2H3N Ethanenitrile (VMSD1212, LB4352_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume C 'Binary Liquid Systems of Nonelectrolytes III' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Trichloromethane CHCl3 + C2H3N Ethanenitrile (VMSD1212, LB4352_V)' providing data by calculation of molar excess volume from low-pressure density measurements at variable mole fraction and constant temperature.

  5. Volumetric Properties of the Mixture Trichloromethane CHCl3 + C4H10S 3-Thiapentane (VMSD1211, LB3237_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume C 'Binary Liquid Systems of Nonelectrolytes III' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Trichloromethane CHCl3 + C4H10S 3-Thiapentane (VMSD1211, LB3237_V)' providing data from direct low-pressure dilatometric measurement of molar excess volume at variable mole fraction and constant temperature.

  6. NESDIS Blended Total Precipitable Water (TPW) Products

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The blended Total Precipitable Water (TPW) product is derived from multiple sensors/satellites. The Percentage of TPW normal (PCT), or TPW anomaly, shows the...

  7. U.S. Hourly Precipitation Data Publication

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This publication contains hourly precipitation amounts obtained from recording rain gages located at National Weather Service, Federal Aviation Administration, and...

  8. U.S. Hourly Precipitation Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Hourly Precipitation Data (HPD) is digital data set DSI-3240, archived at the National Climatic Data Center (NCDC). The primary source of data for this file is...

  9. Processing NPP Bottoms by Ferrocyanide Precipitation

    Energy Technology Data Exchange (ETDEWEB)

    Savkin, A. E.; Slastennikov Y. T.; Sinyakin O. G.

    2002-02-25

    The purpose of work is a laboratory test of a technological scheme for cleaning bottoms from radionuclides by use of ozonization, ferrocyanide precipitation, filtration and selective sorption. At carrying out the ferrocyanide precipitation after ozonization, the specific activity of bottoms by Cs{sup 137} is reduced in 100-500 times. It has been demonstrated that the efficiency of ferrocyanide precipitation depends on the quality of consequent filtration. Pore sizes of a filter has been determined to be less than 0.2 {micro}m for complete separation of ferrocyanide residue. The comparison of two technological schemes for cleaning bottoms from radionuclides, characterized by presence of the ferrocyanide precipitation stage has been performed. Application of the proposed schemes allows reducing volumes of radioactive waste in many times.

  10. Acid precipitation - Effects on forest and fish

    Energy Technology Data Exchange (ETDEWEB)

    Overrein, L.N.; Seip, H.M.; Tollan, A.

    1980-01-01

    The Norwegian Interdisciplinary Research Programme 'Acid Precipitation - Effects on Forest and Fish' (The SNSF-project) was initiated in 1972. The main objectives of the SNSF-project have been to: (1) establish as precisely as possible the effects of acid precipitation on forest and freshwater fish, (2) investigate the effects of air pollutants on soil, vegetation and water, required to satisfy point 1. The final report summarizes the results of the entire program on the basis of some 300 SNSF reports and data presented in various international journals in the period 1972-80. Attention is given to emissions and transport, atmospheric deposits in Norway, water acidification - status and trends, chemical modifications of precipitation in contact with soil and vegetation, snow and snowmelt, land-use changes and acidification, conceptual models for water acidification, effects of acid precipitation on soil productivity and plant growth, and effects of acid water on aquatic life.

  11. Identifying external influences on global precipitation

    Energy Technology Data Exchange (ETDEWEB)

    Marvel, K.; Bonfils, C.

    2013-11-11

    Changes in global (ocean and land) precipitation are among the most important and least well-understood consequences of climate change. Increasing greenhouse gas concentrations are thought to affect the zonal-mean distribution of precipitation through two basic mechanisms. First, increasing temperatures will lead to an intensification of the hydrological cycle (“thermodynamic” changes). Second, changes in atmospheric circulation patterns will lead to poleward displacement of the storm tracks and subtropical dry zones and to a widening of the tropical belt (“dynamic” changes). We demonstrate that both these changes are occurring simultaneously in global precipitation, that this behavior cannot be explained by internal variability alone, and that external influences are responsible for the observed precipitation changes. Whereas existing model experiments are not of sufficient length to differentiate between natural and anthropogenic forcing terms at the 95% confidence level, we present evidence that the observed trends result from human activities.

  12. Precipitation Reconstruction over Land (PREC/L)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The monthly data set consists files of 3 resolutions of monthly averaged precipitation totals. The global analyses are defined by interpolation of gauge observations...

  13. BOREAS HYD-8 Gross Precipitation Data

    Science.gov (United States)

    Fernandes, Richard; Hall, Forrest G. (Editor); Knapp, David E. (Editor); Smith, David E. (Technical Monitor)

    2000-01-01

    The Boreal Ecosystem-Atmosphere Study (BOREAS) Hydrology (HYD)-08 team made measurements of surface hydrological processes at the Southern Study Area-Old Black Spruce (SSA-OBS) Tower Flux site to support its research into point hydrological processes and the spatial variation of these processes. Data collected may be useful in characterizing canopy interception, drip, throughfall, moss interception, drainage, evaporation, and capacity during the growing season at daily temporal resolution. This particular data set contains the gross precipitation measurements for July to August 1996. Gross precipitation is the precipitation that falls that is not intercepted by tree canopies. These data are stored in ASCII text files. The HYD-08 gross precipitation data are available from the Earth Observing System Data and Information System (EOSDIS) Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC). The data files are available on a CD-ROM (see document number 20010000884).

  14. Application of probabilistic precipitation forecasts from a ...

    African Journals Online (AJOL)

    Application of probabilistic precipitation forecasts from a deterministic model towards increasing the lead-time of flash flood forecasts in South Africa. ... An ensemble set of 30 adjacent basins is then identified as ensemble members for each ...

  15. Average Annual Precipitation (PRISM model) 1961 - 1990

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer shows polygons of average annual precipitation in the contiguous United States, for the climatological period 1961-1990. Parameter-elevation...

  16. VT Mean Annual Precipitation - 1971-2000

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) ClimatePrecip_PRECIPA7100 includes mean annual precipitation data (in inches) for Vermont (1971-2000). It's a raster dataset derived from...

  17. VT Mean Winter Precipitation - 1971-2000

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) ClimatePrecip_PRECIPW7100 includes mean winter precipitation data (October through March) for Vermont (1971-2000). It's a raster dataset derived...

  18. Precipitation Aggregation and the Local Environment

    Science.gov (United States)

    Smalley, Mark

    The details of large-scale spatial structures of precipitation have only recently become apparent with the advent of high-resolution near-global observations from space-borne radars. As such, the relationships between these structures and the local environment and global climate are just beginning to emerge in the scientific community. Precipitation aggregates on a wide variety of scales, from individual boundary layer instabilities to extra-tropical cyclones. Separate aggregation states have been associated with widely varying precipitation rates and atmospheric states, motivating the inclusion of spatial information in hydrologic and climate models. This work adds to the body of knowledge surrounding large-scale precipitation aggregation and its driving factors by describing and demonstrating a new method of defining the spatial characteristics of precipitation events. The analysis relies on the high sensitivity and high resolution of the CloudSat Cloud Profiling Radar for the identification of precipitation with near-global coverage. The method is based on the dependence of the probability of precipitation on search area, or spatial resolution. Variations in this relationship are caused by variations in the principal characteristics of event spatial patterns: the relative spacing between events, the number density of events, and the overall fraction of precipitating scenes at high resolution. Here, this relationship is modeled by a stretched exponential containing two coefficients, that are shown to depict seasonal general circulation patterns as well as local weather. NASA's Modern-Era Retrospective analysis for Research and Applications is then used to place those spatial characteristics in the context of the local and large-scale environment. At regional scale, precipitation event density during the Amazon wet season is shown to be dependent on zonal wind speed. On a global scale, the relative spacing of shallow oceanic precipitation depends on the

  19. Nordic Seas Precipitation Ground Validation Project

    Science.gov (United States)

    Klepp, Christian; Bumke, Karl; Bakan, Stephan; Andersson, Axel

    2010-05-01

    A thorough knowledge of global ocean precipitation is an indispensable prerequisite for the understanding of the water cycle in the global climate system. However, reliable detection of precipitation over the global oceans, especially of solid precipitation, remains a challenging task. This is true for both, passive microwave remote sensing and reanalysis based model estimates. The satellite based HOAPS (Hamburg Ocean Atmosphere Parameters and Fluxes from Satellite Data) climatology contains fields of precipitation, evaporation and the resulting freshwater flux along with 12 additional atmospheric parameters over the global ice-free ocean between 1987 and 2005. Except for the NOAA Pathfinder SST, all basic state variables are calculated from SSM/I passive microwave radiometer measurements. HOAPS contains three main data subsets that originate from one common pixel-level data source. Gridded 0.5 degree monthly, pentad and twice daily data products are freely available from www.hoaps.org. The optical disdrometer ODM 470 is a ground validation instrument capable of measuring rain and snowfall on ships even under high wind speeds. It was used for the first time over the Nordic Seas during the LOFZY 2005 campaign. A dichotomous verification for these snowfall events resulted in a perfect score between the disdrometer, a precipitation detector and a shipboard observer's log. The disdrometer data is further point-to-area collocated against precipitation from three satellite derived climatologies, HOAPS-3, the Global Precipitation Climatology Project (GPCP) one degree daily (1DD) data set, and the Goddard Profiling algorithm, version 2004 (GPROF 2004). Only the HOAPS precipitation turns out to be overall consistent with the disdrometer data resulting in an accuracy of 0.96. The collocated data comprises light precipitation events below 1 mm/h. Therefore two LOFZY case studies with high precipitation rates are presented that still indicate plausible results. Overall, this

  20. TEM Study of High-Temperature Precipitation of Delta Phase in Inconel 718 Alloy

    Directory of Open Access Journals (Sweden)

    Moukrane Dehmas

    2011-01-01

    Full Text Available Inconel 718 is widely used because of its ability to retain strength at up to 650∘C for long periods of time through coherent metastable  Ni3Nb precipitation associated with a smaller volume fraction of  Ni3Al precipitates. At very long ageing times at service temperature,  decomposes to the stable Ni3Nb phase. This latter phase is also present above the  solvus and is used for grain control during forging of alloy 718. While most works available on precipitation have been performed at temperatures below the  solvus, it appeared of interest to also investigate the case where phase precipitates directly from the fcc matrix free of  precipitates. This was studied by X-ray diffraction and transmission electron microscopy (TEM. TEM observations confirmed the presence of rotation-ordered domains in plates, and some unexpected contrast could be explained by double diffraction due to overlapping phases.

  1. Energy distribution of precipitating electrons estimated from optical and cosmic noise absorption measurements

    Directory of Open Access Journals (Sweden)

    H. Mori

    2004-04-01

    Full Text Available This study is a statistical analysis on energy distribution of precipitating electrons, based on CNA (cosmic noise absorption data obtained from the 256-element imaging riometer in Poker Flat, Alaska (65.11° N, 147.42° W, and optical data measured with an MSP (Meridian Scanning Photometer over 79 days during the winter periods from 1996 to 1998. On the assumption that energy distributions of precipitating electrons represent Maxwellian distributions, CNA is estimated based on the observation data of auroral 427.8-nm and 630.0-nm emissions, as well as the average atmospheric model, and compared with the actual observation data. Although the observation data have a broad distribution, they show systematically larger CNA than the model estimate. CNA determination using kappa or double Maxwellian distributions, instead of Maxwellian distributions, better explains the distribution of observed CNA data. Kappa distributions represent a typical energy distribution of electrons in the plasma sheet of the magnetosphere, the source region of precipitating electrons. Pure kappas are more likely during quiet times – and quiet times are more likely than active times. This result suggests that the energy distribution of precipitating electrons reflects the energy distribution of electrons in the plasma sheet.

    Key words. Ionosphere (auroral ionosphere; particle precipitation; polar ionosphere

  2. Effects of combined silicon and molybdenum alloying on the size and evolution of microalloy precipitates in HSLA steels containing niobium and titanium

    Energy Technology Data Exchange (ETDEWEB)

    Pavlina, Erik J., E-mail: e.pavlina@deakin.edu.au [Deakin University, Institute for Frontier Materials, 75 Pigdons Road, Waurn Ponds, Victoria (Australia); Van Tyne, C.J.; Speer, J.G. [Colorado School of Mines, Advanced Steel Processing and Products Research Center, 1500 Illinois Street, Golden, CO (United States)

    2015-04-15

    The effects of combined silicon and molybdenum alloying additions on microalloy precipitate formation in austenite after single- and double-step deformations below the austenite no-recrystallization temperature were examined in high-strength low-alloy (HSLA) steels microalloyed with titanium and niobium. The precipitation sequence in austenite was evaluated following an interrupted thermomechanical processing simulation using transmission electron microscopy. Large (~ 105 nm), cuboidal titanium-rich nitride precipitates showed no evolution in size during reheating and simulated thermomechanical processing. The average size and size distribution of these precipitates were also not affected by the combined silicon and molybdenum additions or by deformation. Relatively fine (< 20 nm), irregular-shaped niobium-rich carbonitride precipitates formed in austenite during isothermal holding at 1173 K. Based upon analysis that incorporated precipitate growth and coarsening models, the combined silicon and molybdenum additions were considered to increase the diffusivity of niobium in austenite by over 30% and result in coarser precipitates at 1173 K compared to the lower alloyed steel. Deformation decreased the size of the niobium-rich carbonitride precipitates that formed in austenite. - Highlights: • We examine combined Si and Mo additions on microalloy precipitation in austenite. • Precipitate size tends to decrease with increasing deformation steps. • Combined Si and Mo alloying additions increase the diffusivity of Nb in austenite.

  3. Climate Prediction Center (CPC) Global Precipitation Time Series

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The global precipitation time series provides time series charts showing observations of daily precipitation as well as accumulated precipitation compared to normal...

  4. Aspects of precipitation in alloy Inconel 718

    OpenAIRE

    Azadian, Saied

    2004-01-01

    A study was made of the microstructure of the Ni-base alloy Inconel 718 with emphasis on the precipitation and stability of intermetallic phases as affected by heat treatments. In addition the effect of the precipitation on selected mechanical properties namely hardness, creep notch sensitivity and hot ductlity were investigated. The materials studied were a spray-formed version and three wrought versions of the alloy. The spray-formed version of the alloy was of interest since it exhibited a...

  5. Precipitation Nowcast using Deep Recurrent Neural Network

    Science.gov (United States)

    Akbari Asanjan, A.; Yang, T.; Gao, X.; Hsu, K. L.; Sorooshian, S.

    2016-12-01

    An accurate precipitation nowcast (0-6 hours) with a fine temporal and spatial resolution has always been an important prerequisite for flood warning, streamflow prediction and risk management. Most of the popular approaches used for forecasting precipitation can be categorized into two groups. One type of precipitation forecast relies on numerical modeling of the physical dynamics of atmosphere and another is based on empirical and statistical regression models derived by local hydrologists or meteorologists. Given the recent advances in artificial intelligence, in this study a powerful Deep Recurrent Neural Network, termed as Long Short-Term Memory (LSTM) model, is creatively used to extract the patterns and forecast the spatial and temporal variability of Cloud Top Brightness Temperature (CTBT) observed from GOES satellite. Then, a 0-6 hours precipitation nowcast is produced using a Precipitation Estimation from Remote Sensing Information using Artificial Neural Network (PERSIANN) algorithm, in which the CTBT nowcast is used as the PERSIANN algorithm's raw inputs. Two case studies over the continental U.S. have been conducted that demonstrate the improvement of proposed approach as compared to a classical Feed Forward Neural Network and a couple simple regression models. The advantages and disadvantages of the proposed method are summarized with regard to its capability of pattern recognition through time, handling of vanishing gradient during model learning, and working with sparse data. The studies show that the LSTM model performs better than other methods, and it is able to learn the temporal evolution of the precipitation events through over 1000 time lags. The uniqueness of PERSIANN's algorithm enables an alternative precipitation nowcast approach as demonstrated in this study, in which the CTBT prediction is produced and used as the inputs for generating precipitation nowcast.

  6. Discontinuous precipitation in copper base alloys

    Indian Academy of Sciences (India)

    K T Kashyap

    2009-08-01

    Discontinuous precipitation (DP) is associated with grain boundary migration in the wake of which alternate plates of the precipitate and the depleted matrix form. Some copper base alloys show DP while others do not. In this paper the misfit strain parameter, , has been calculated and predicted that if 100 > ± 0.1, DP is observed. This criterion points to diffusional coherency strain theory to be the operative mechanism for DP.

  7. 1-D diffusion based solidification model with volumetric expansion and shrinkage effect: A semi-analytical approach

    Science.gov (United States)

    Monde, Aniket D.; Chakraborty, Prodyut R.

    2017-10-01

    Volumetric expansion and shrinkage due to different densities of solid and liquid phases are common phenomena during solidification process. Simple analytical models addressing effect of volumetric expansion/shrinkage during solidification are rarely found. The few existing 1-D solidification models are valid only for semi-infinite domain with limitations of their application for finite domain size. The focus of the present work is to develop a 1-D semi-analytical solidification model addressing effects of volumetric expansion/shrinkage in a finite domain. The proposed semi-analytical scheme involves finding simultaneous solution of transient 1-D heat diffusion equations at solid and liquid domain coupled at the interface by Stefan condition. The change of the total domain length during solidification due to volumetric expansion/shrinkage is addressed by using mass conservation. For validation of the proposed model, solidification of water in a finite domain is studied without considering volumetric expansion/shrinkage effect and results are compared with those obtained from existing enthalpy updating based numerical model. After validation, case studies pertaining to volumetric expansion and shrinkage are performed considering solidification of water and paraffin respectively and physically consistent results are obtained. The study is relevant for understanding unidirectional crystal growth under the effect of controlled boundary condition.

  8. Precipitation in a lead calcium tin anode

    Energy Technology Data Exchange (ETDEWEB)

    Perez-Gonzalez, Francisco A., E-mail: fco.aurelio@inbox.com [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon (Mexico); Centro de Innovacion, Investigacion y Desarrollo en Ingenieria y Tecnologia, Universidad Autonoma de Nuevo Leon (Mexico); Camurri, Carlos G., E-mail: ccamurri@udec.cl [Departamento de Ingenieria de Materiales, Universidad de Concepcion (Chile); Carrasco, Claudia A., E-mail: ccarrascoc@udec.cl [Departamento de Ingenieria de Materiales, Universidad de Concepcion (Chile); Colas, Rafael, E-mail: rafael.colas@uanl.edu.mx [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon (Mexico); Centro de Innovacion, Investigacion y Desarrollo en Ingenieria y Tecnologia, Universidad Autonoma de Nuevo Leon (Mexico)

    2012-02-15

    Samples from a hot rolled sheet of a tin and calcium bearing lead alloy were solution heat treated at 300 Degree-Sign C and cooled down to room temperature at different rates; these samples were left at room temperature to study natural precipitation of CaSn{sub 3} particles. The samples were aged for 45 days before analysing their microstructure, which was carried out in a scanning electron microscope using secondary and backscattered electron detectors. Selected X-ray spectra analyses were conducted to verify the nature of the precipitates. Images were taken at different magnifications in both modes of observation to locate the precipitates and record their position within the images and calculate the distance between them. Differential scanning calorimeter analyses were conducted on selected samples. It was found that the mechanical properties of the material correlate with the minimum average distance between precipitates, which is related to the average cooling rate from solution heat treatment. - Highlights: Black-Right-Pointing-Pointer The distance between precipitates in a lead alloy is recorded. Black-Right-Pointing-Pointer The relationship between the distance and the cooling rate is established. Black-Right-Pointing-Pointer It is found that the strengthening of the alloy depends on the distance between precipitates.

  9. Microbially Induced Precipitation of Strontianite Nanoparticles.

    Science.gov (United States)

    Kang, Serku; Yumi Kim; Lee, Young Jae; Roh, Yul

    2015-07-01

    The objectives of this study were to investigate the microbially mediated precipitation of strontium by microorganisms, and to examine the mineralogical characteristics of the precipitates. Wu Do-1 (Proteus mirabilis) enriched from rhodoliths was used to precipitate strontium at room temperature under aerobic environment. The growth of Wu Do-1 gradually increased over 16 days (OD600 = 2.6) and then decreased until 22 days (OD600 = 2.0) during microbial incubation for strontium precipitation. Also, the pH decreased from 6.5 to 5.3 over 4 days of incubation due to microbial oxidation of organic acids, and then the pH increased up to 8.6 at 25 days of incubation due to NH3+ generation. The Sr2+ concentration in the biotic group sharply decreased from 2,953 mg/L to 5.7 mg/L over 29 days of incubation. XRD, SEM-/TEM-EDS analyses revealed that the precipitates formed by Wu Do-1 (Proteus mirabilis) were identified as 20-70 nm sized strontianite (SrCO3). Therefore, these results suggested that formation of sparingly soluble Sr precipitates mediated by Wu Do-1 (Proteus mirabilis) sequesters strontium and carbon dioxide into a more stable and less toxic form such as strontianite (SrCO3). These results also suggest that bioremediation of metal-contaminated water and biominealization of carbonate minerals may be feasible in the marine environment.

  10. Sensitivity to the representation of precipitating ice in CRM simulations of deep convection

    Science.gov (United States)

    Swann, Hugh

    A Cloud resolving model (CRM) is a useful tool for providing a proxy for observed data, against which parameterizations of convection in global and regional models can be compared. The parameterization of microphysics in CRMs has been shown to be crucial for the simulation of the evolution of heat and moisture profiles during deep convection. The aim of the study described herein is to validate the microphysics scheme in the U.K. Met. Office's Large Eddy Model as a prelude to future work where simulations of deep convection will be compared to a single column version of the Met. Office's Unified model. Three observed cases of convection are simulated each with different precipitation production mechanisms, as deduced by the multiparameter radar at Chilbolton. Four simulations are carried out of each case, using different representations of precipitation. The aim is to determine whether a flexible microphysics scheme is capable of modelling the evolution of the precipitation in each of the cases without recourse to tuning coefficients for case-specific conditions. The simulations are validated against radar observations by comparing spatial distribution of radar reflectivity and the type of precipitation at the melting layer. A number of systematic errors occur in simulations using a `single-moment' microphysics scheme (where graupel and snow mass concentrations are each represented with one variable and the number concentrations are prescribed). Whereas a `double-moment' microphysics scheme (that predicts both the mass and number concentrations of snow and graupel) produced simulations consistent with radar observations for all three cases. The sensitivity of important quantities relating to the parameterization of convection in GCMs to the microphysical parameterization has been examined. The total precipitation at the ground and the amount of cloud ice are compared between simulations that differ only in their representation of precipitation. The total

  11. Single and double metallothionein knockout in the nematode C. elegans reveals cadmium dependent and independent toxic effects on life history traits

    Energy Technology Data Exchange (ETDEWEB)

    Hughes, Sam [School of Biosciences, Cardiff University, Main Building, Park Place, Cardiff CF10 3TL (United Kingdom); School of Biomedical and Health Sciences, Pharmaceutical Sciences Research Division, King' s College London, 150 Stamford Street, London SE1 9NH (United Kingdom); Stuerzenbaum, Stephen R. [School of Biosciences, Cardiff University, Main Building, Park Place, Cardiff CF10 3TL (United Kingdom) and School of Biomedical and Health Sciences, Pharmaceutical Sciences Research Division, King' s College London, 150 Stamford Street, London SE1 9NH (United Kingdom)]. E-mail: stephen.sturzenbaum@kcl.ac.uk

    2007-01-15

    The genome of the nematode Caenorhabditis elegans contains two metallothionein genes, both involved in metal homeostasis and/or detoxification. Single metallothionein knockout mutants have been created and now, for the first time, a double mutant has been isolated. Life history studies in the presence or absence of cadmium showed that all metallothionein mutants are viable. Although cadmium did not influence longevity, a dose dependent reduction in total brood size and volumetric growth was observed in wild type animals, which was magnified in single knockouts and further exacerbated in the double knockout. However, the metallothionein deletion caused two effects that are independent of cadmium exposure, namely all knockout strains displayed a reduced total brood size and the deletion of both metallothionein loci caused a significant reduction in volumetric growth. In summary, metallothionein is undoubtedly an important player in cadmium detoxification, but evidently also an important factor in cadmium independent pathways. - Metallothionein is a modifier of life-history parameters.

  12. Double-Skin Facade

    DEFF Research Database (Denmark)

    Kalyanova, Olena

    difficulties experienced by scientists when attempting to model DSF thermal and energy performance were examined. In addition, the lack of experimental studies and empirical validation of models was realized, many numerical models have not been empirically validated and most of them require an expert knowledge...... IEA Annex 34/43, subtask E "Double-Skin Facade". The results of empirical validation are discussed in this work. Discussion and analysis of experimental results is carried out. It has lead to hypothesis of recirculation flow phenomenon in the DSF cavity. Finally, a suggestion of a new numerical model......Double-Skin Facades (DSF) are gaining popularity that, in fact, appears to be independent from sturdy critics of the concept in the past years. DSF buildings are being built in Europe and worldwide, DSF concept is being taught at schools of architecture and fully glazed office buildings are being...

  13. Algebra of Majorana doubling.

    Science.gov (United States)

    Lee, Jaehoon; Wilczek, Frank

    2013-11-27

    Motivated by the problem of identifying Majorana mode operators at junctions, we analyze a basic algebraic structure leading to a doubled spectrum. For general (nonlinear) interactions the emergent mode creation operator is highly nonlinear in the original effective mode operators, and therefore also in the underlying electron creation and destruction operators. This phenomenon could open up new possibilities for controlled dynamical manipulation of the modes. We briefly compare and contrast related issues in the Pfaffian quantum Hall state.

  14. Double Cortex Syndrome

    OpenAIRE

    1999-01-01

    The incidence of mutations in the X-linked gene doublecortin in patients with “double cortex” syndrome (DC; also called subcortical band heterotopia or laminar heterotopia) and familial DC with lissencephaly was investigated in a cohort of 8 pedigrees and 47 sporadic patients with DC examined at the Division of Neurogenics, Beth Israel Deaconess Medical Center, Boston, and multiple centers in the US and abroad.

  15. Twisted quantum doubles

    Directory of Open Access Journals (Sweden)

    Daijiro Fukuda

    2004-01-01

    Full Text Available Using diagrammatic pictures of tensor contractions, we consider a Hopf algebra (Aop⊗ℛλA** twisted by an element ℛλ∈A*⊗Aop corresponding to a Hopf algebra morphism λ:A→A. We show that this Hopf algebra is quasitriangular with the universal R-matrix coming from ℛλ when λ2=idA, generalizing the quantum double construction which corresponds to the case λ=idA.

  16. Double-Glazing Interferometry

    OpenAIRE

    Toal, Vincent; Mihaylova, Emilia

    2009-01-01

    This note describes how white light interference fringes can be seen by observing the Moon through a double-glazed window. White light interferometric fringes are normally observed only in a well-aligned interferometer whose optical path difference is less than the coherence length of the light source, which is approximately one micrometer for white light. Obtaining such fringes in a Michelson interferometer is not a trivial task.1 The interferometer is typically illuminated with a monochroma...

  17. Global Precipitation Measurement (GPM) Mission: Precipitation Processing System (PPS) GPM Mission Gridded Text Products Provide Surface Precipitation Retrievals

    Science.gov (United States)

    Stocker, Erich Franz; Kelley, O.; Kummerow, C.; Huffman, G.; Olson, W.; Kwiatkowski, J.

    2015-01-01

    In February 2015, the Global Precipitation Measurement (GPM) mission core satellite will complete its first year in space. The core satellite carries a conically scanning microwave imager called the GPM Microwave Imager (GMI), which also has 166 GHz and 183 GHz frequency channels. The GPM core satellite also carries a dual frequency radar (DPR) which operates at Ku frequency, similar to the Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar, and a new Ka frequency. The precipitation processing system (PPS) is producing swath-based instantaneous precipitation retrievals from GMI, both radars including a dual-frequency product, and a combined GMIDPR precipitation retrieval. These level 2 products are written in the HDF5 format and have many additional parameters beyond surface precipitation that are organized into appropriate groups. While these retrieval algorithms were developed prior to launch and are not optimal, these algorithms are producing very creditable retrievals. It is appropriate for a wide group of users to have access to the GPM retrievals. However, for researchers requiring only surface precipitation, these L2 swath products can appear to be very intimidating and they certainly do contain many more variables than the average researcher needs. Some researchers desire only surface retrievals stored in a simple easily accessible format. In response, PPS has begun to produce gridded text based products that contain just the most widely used variables for each instrument (surface rainfall rate, fraction liquid, fraction convective) in a single line for each grid box that contains one or more observations.This paper will describe the gridded data products that are being produced and provide an overview of their content. Currently two types of gridded products are being produced: (1) surface precipitation retrievals from the core satellite instruments GMI, DPR, and combined GMIDPR (2) surface precipitation retrievals for the partner constellation

  18. Characteristics of the precipitation recycling ratio and its relationship with regional precipitation in China

    Science.gov (United States)

    Hua, Lijuan; Zhong, Linhao; Ke, Zongjian

    2017-02-01

    A dynamic recycling model (DRM) with an analytical moisture trajectory tracking method, together with Japan Meteorological Agency 25-year reanalysis data, is used to study the regional precipitation recycling process across China, by calculating the regional recycling ratio ( ρ r ) at the daily time scale during 1979-2010. The distribution of ρ r shows that, in western China, especially the Tibetan Plateau and its surrounding areas, precipitation is strongly dependent on the recycling process associated with regional evaporation. In Southeast China, however, the contribution from the recycling processes is much smaller due to the influence of the summer monsoon. A precipitation threshold value of about 4 mm/day is obtained from detailed analysis of both extreme and all-range ρ r years. According to this threshold, China is classified into three types of sub-regions: low-precipitation sub-regions (mainly in the northwest), high-precipitation sub-regions (mainly in the south), and medium-precipitation sub-regions (mainly in the northeast). It is found that ρ r correlates positively with precipitation, as well as convective precipitation ( P CP) and large-scale precipitation ( P LP) in the low-precipitation sub-regions. However, negative ρ r ˜ P LP correlations are found in the high-precipitation sub-regions and nonsignificant correlations exist in the medium-precipitation sub-regions. As P CP is mainly locally generated due to mid-latitude mesoscale systems and the cumulus parameterization used in producing the reanalysis, the recycling ratio positively correlates to the ratio P CP/ P LP in almost all sub-regions, particularly in the Tibetan Plateau and its surrounding areas. The correlation between radiation flux and ρ r suggests more net radiation supports more evaporation and higher ρ r , especially in the high-precipitation sub-regions. The influence of clouds on shortwave radiation is crucial, since evaporation is suppressed when the amount of cloudiness

  19. [Comment on “A new interdisciplinary focus on precipitation research”] Precipitation research

    Science.gov (United States)

    Rodda, John C.

    I am writing concerning the lead article in the June 5, 1984, Eos, entitled “A new interdisciplinary focus on precipitation research,” particularly the paragraph headed “Measurement of Precipitation.” Measurement of precipitation is a subject of which I know a little. My knowledge comes largely from experimental work in the 1960s and 1970s and committee work subsequently (I even attended one meeting of the 1970 AGU committee). I imagined that, at that time and subsequently, it had become an acknowledged fact in the United States and elsewhere that measurements of precipitation are not easy to make.

  20. Double pendulum contact problem

    Directory of Open Access Journals (Sweden)

    Špička J.

    2014-06-01

    Full Text Available The work concerns contact problems focused on biomechanical systems modelled by a multibody approach. The example is modelling of impact between a body and an infrastructure. The paper firstly presents algorithm for minimum distance calculation. An analytical approach using a tangential plain perpendicular to an initial one is applied. Contact force generated during impact is compared by three different continuous force models, namely the Hertz’s model, the spring-dashpot model and the non-linear damping model. In order to identify contact parameters of these particular models, the method of numerical optimization is used. Purpose of this method is to find the most corresponding results of numerical simulation to the original experiment. Numerical optimization principle is put upon a bouncing ball example for the purpose of evaluation of desirable contact force parameters. The contact modelling is applied to a double pendulum problem. The equation of motion of the double pendulum system is derived using Lagrange equation of the second kind with multipliers, respecting the contact phenomena. Applications in biomechanical research are hinted at arm gravity motion and a double pendulum impact example.