WorldWideScience

Sample records for space filling molecular

  1. Space-filling Curves

    Indian Academy of Sciences (India)

    mathematics and computer applications for the last 20 years. He has been a National Science. Talent awardee of. NCERT in mathematics. GENERAL I ARTICLE. Space-filling Curves. ReMittal. In this article some Peano curves are exhibited and some of their recent applications are dis- cussed. A C++ program to draw the ...

  2. Space filling curves in steganalysis

    Science.gov (United States)

    Westfeld, Andreas

    2005-03-01

    We introduce a new method to increase the reliability of current steganalytic techniques by optimising the sample order. Space filling curves (e.g., Hilbert curve) take advantage of the correlation of adjacent pixels and thus make the detection of steganographic messages with low change densities more reliable. The findings are applicable, but not limited to LSB steganalysis. An experimental comparison of five different sampling paths reveals that recursive principles achieve by far the best performance. All measures, such as mean distance, median autocorrelation, and the ability to detect even tiny modifications show substantial improvements compared to conventional methods. We elaborate the relationship between those parameters and quantify the effectiveness with a large test database of small images, which are usually hard to detect. Apart from quantitative advances, visualisation of steganalytic measures can also gain from the application of reverse space filling curves.

  3. Space-filling curves for image compression

    Science.gov (United States)

    Moghaddam, Baback; Hintz, Kenneth J.; Stewart, Clayton V.

    1991-08-01

    This paper outlines the use of space-filling curves in transform image compression. Specifically, a space-filling Hilbert curve is used for mapping the two-dimensional image into a suitable one-dimensional representation. Compared to simple raster-scans, this topological mapping is spatially non-disruptive and tends to preserve local pixel correlations in the original two-dimensional image. Standard transform coefficient reduction and coding techniques can then be applied to the one-dimensional representation for the purposes of data compression. The advantages of the one-dimensional coding, in terms of computational cost and subjective image quality, are also discussed.

  4. Diversions: Hilbert and Sierpinski Space-Filling Curves, and beyond

    Science.gov (United States)

    Gough, John

    2012-01-01

    Space-filling curves are related to fractals, in that they have self-similar patterns. Such space-filling curves were originally developed as conceptual mathematical "monsters", counter-examples to Weierstrassian and Reimannian treatments of calculus and continuity. These were curves that were everywhere-connected but…

  5. Sudoku-based space-filling designs

    National Research Council Canada - National Science Library

    XU XU; BEN HAALAND; PETER Z. G. QIAN

    2011-01-01

    .... The game board is a nine-by-nine grid of numbers from one to nine. Several entries within the grid are provided and the remaining entries must be filled in subject to no row, column, or three-by-three subsquare containing duplicate numbers...

  6. Molecular investigations on grain filling rate under terminal heat ...

    African Journals Online (AJOL)

    Molecular investigations on grain filling rate under terminal heat stress in bread wheat (Triticum aestivum L.) Girish Chandra Pandey, Jagadish Rane, Sindhu Sareen, Priyanka Siwach, NK Singh, Ratan Tiwari ...

  7. Space-time-filling branes and strings with sixteen supercharges

    NARCIS (Netherlands)

    Bergshoeff, E; Eyras, E; Halbersma, R; van der Schaar, JP; Hull, CM; Lozano, Y

    2000-01-01

    We discuss branes whose world-volume dimension equals the target space-time dimension, i.e. "space-time-filling branes". In addition to the D9-branes, there are 9-branes in the NS-NS sectors of both the IIA and IIB strings. The world-volume actions of these branes are constructed, via duality, from

  8. Space filling modular optics: expanded Peano and collapsed Hilbert curves

    Science.gov (United States)

    Schamschula, Marius P.; Caulfield, H. John

    1994-10-01

    Recently we introduced space filling curves such as the Peano and Hilbert curves as a method of realizing compact modular optics. In this paper we modify the primitives of these curves to construct novel compact two-dimensional modular optical systems.

  9. Dimensions of the coordinate functions of space-filling curves

    Science.gov (United States)

    Allaart, Pieter C.; Kawamura, Kiko

    2007-11-01

    The graphs of coordinate functions of space-filling curves such as those described by Peano, Hilbert, Pólya and others, are typical examples of self-affine sets, and their Hausdorff dimensions have been the subject of several articles in the mathematical literature. In the first half of this paper, we describe how the study of dimensions of self-affine sets was motivated, at least in part, by these coordinate functions and their natural generalizations, and review the relevant literature. In the second part, we present new results on the coordinate functions of Pólya's one-parameter family of space-filling curves. We give a lower bound for the Hausdorff dimension of their graphs which is fairly close to the box-counting dimension. Our techniques are largely probabilistic. The fact that the exact dimension remains elusive seems to indicate the need for further work in the area of self-affine sets.

  10. Filling the Empty Space: Women and Latin American Theatre

    Directory of Open Access Journals (Sweden)

    Kirsten F. Nigro

    1996-01-01

    Full Text Available In recent years, Latin American women have begun to appropriate and fill a space once empty of their presence. This essay looks at the work of four such women, (Diana Raznovich and Cristina Escofet of Argentina, Raquel Araujo of Mexico and the Peruvian Sara Joffre, to see how they give substance and voice to their particular concerns. In the process, this essay focusses on: 1 the notion of gender as performance; 2 the feminist deconstruction of narrative; 3 the female body in theatrical space; and 4 new, postmodern ways of doing feminist political theatre.

  11. Distributed Overlay Anycast Table using Space filling curves

    OpenAIRE

    Mykoniati, Eleni; Latif, Laurence; Landa, Raul; Yang, Ben; Clegg, Richard G.; Griffin, David; Rio, Miguel

    2013-01-01

    In this paper we present the \\emph{Distributed Overlay Anycast Table}, a structured overlay that implements application-layer anycast, allowing the discovery of the closest host that is a member of a given group. One application is in locality-aware peer-to-peer networks, where peers need to discover low-latency peers participating in the distribution of a particular file or stream. The DOAT makes use of network delay coordinates and a space filling curve to achieve locality-aware routing acr...

  12. Space-Filling Curves for Quantum Control Parameters

    Science.gov (United States)

    Shafee, Fariel

    2006-06-01

    We consider the use of space-filling curves (SFC) in scanning control parameters for quantum chemical systems. First we show that a formally exact SFC must be singular in the control parameters, but a finite discrete generalization can be used with no problem. We then make general observations about the relevance of SFCs in preference to linear scans of the parameters. Finally we present a simple magnetic field example relevant in NMR and show from the calculated autocorrelations that a SFC Peano-Hilbert curve gives a smoother sequence than a linear scan.

  13. Space-Filling Curves as a Novel Crystal Structure Representation for Machine Learning Models

    CERN Document Server

    Jasrasaria, Dipti; Rappoport, Dmitrij; Aspuru-Guzik, Alan

    2016-01-01

    A fundamental problem in applying machine learning techniques for chemical problems is to find suitable representations for molecular and crystal structures. While the structure representations based on atom connectivities are prevalent for molecules, two-dimensional descriptors are not suitable for describing molecular crystals. In this work, we introduce the SFC-M family of feature representations, which are based on Morton space-filling curves, as an alternative means of representing crystal structures. Latent Semantic Indexing (LSI) was employed in a novel setting to reduce sparsity of feature representations. The quality of the SFC-M representations were assessed by using them in combination with artificial neural networks to predict Density Functional Theory (DFT) single point, Ewald summed, lattice, and many-body dispersion energies of 839 organic molecular crystal unit cells from the Cambridge Structural Database that consist of the elements C, H, N, and O. Promising initial results suggest that the S...

  14. Space station molecular sieve development

    Science.gov (United States)

    Chang, C.; Rousseau, J.

    1986-01-01

    An essential function of a space environmental control system is the removal of carbon dioxide (CO2) from the atmosphere to control the partial pressure of this gas at levels lower than 3 mm Hg. The use of regenerable solid adsorbents for this purpose was demonstrated effectively during the Skylab mission. Earlier sorbent systems used zeolite molecular sieves. The carbon molecular sieve is a hydrophobic adsorbent with excellent potential for space station application. Although carbon molecular sieves were synthesized and investigated, these sieves were designed to simulate the sieving properties of 5A zeolite and for O2/N2 separation. This program was designed to develop hydrophobic carbon molecular sieves for CO2 removal from a space station crew environment. It is a first phase effort involved in sorbent material development and in demonstrating the utility of such a material for CO2 removal on space stations. The sieve must incorporate the following requirements: it must be hydrophobic; it must have high dynamic capacity for carbon dioxide at the low partial pressure of the space station atmosphere; and it must be chemiclly stable and will not generate contaminants.

  15. A Novel Construction Method for n-Dimensional Hilbert Space-Filling Curves

    Science.gov (United States)

    Chen, Chih-Sheng; Lin, Shen-Yi; Fan, Min-Hsuan; Huang, Chua-Huang

    We develop a novel construction method forn-dimensional Hilbert space-filling curves. The construction method includes four steps: block allocation, Gray permutation, coordinate transformation and recursive construction. We use the tensor product theory to formulate the method. Ann-dimensional Hilbert space-filling curve of 2r elements on each dimension is specified as a permutation which rearranges 2rn data elements stored in the row major order as in C language or the column major order as in FORTRAN language to the order of traversing ann-dimensional Hilbert space-filling curve. The tensor product formulation ofn-dimensional Hilbert space-filling curves uses stride permutation, reverse permutation, and Gray permutation. We present both recursive and iterative tensor product formulas ofn-dimensional Hilbert space-filling curves. The tensor product formulas are directly translated into computer programs which can be used in various applications. The process of program generation is explained in the paper.

  16. Molecular investigations on grain filling rate under terminal heat ...

    African Journals Online (AJOL)

    Ezedom Theresa

    2013-07-10

    Jul 10, 2013 ... of determination (R2) was recorded 0.10 and 0.06, respectively. This indicates that the two markers were associated with the differences in grain filling (dGFR) rate as indicator for heat tolerance. Xbarc04 (Figure 1) and. Xgwm314 have their locus position on chromosomes 5B and 3D, respectively (Table 2).

  17. Molecular investigations on grain filling rate under terminal heat ...

    African Journals Online (AJOL)

    Ezedom Theresa

    2013-07-10

    Jul 10, 2013 ... Grain yield under post anthesis high temperature stress is largely influenced by grain filling rate (GFR). To investigate ... 75% of the progenies showed no difference while 25% showed significant difference in GFR under high temperature .... timely (normal) and late (terminal heat stress) conditions. Data on.

  18. Nanocapsules with fluorous filling: A "molecular zipper" approach

    KAUST Repository

    Merican, Zulkifli

    2014-11-26

    Considerable effort has been devoted to thesynthesis of liquid filled microcapsules and nanocapsules owing to their general usefulness. The DCM solution was combined with an equal volume of the aqueous solution of sodium dodecylsulfate (SDS), and the biphasic mixture was subjected to high-power ultrasound treatment. Furthermore, it is likely that the interlocking of the polymer chains in the hydrophobic layer of the capsule shells leads to objects that are strong and stable. It is worth noting that the cryo-TEM images were obtained for a sample that was more than 30 days old. The self-assembly of capsule shells and their stability depend on the nature and size of both hydrophobic and hydrophilic polymer blocks.

  19. Space-Time Water-Filling for Composite MIMO Fading Channels

    Directory of Open Access Journals (Sweden)

    2006-01-01

    Full Text Available We analyze the ergodic capacity and channel outage probability for a composite MIMO channel model, which includes both fast fading and shadowing effects. The ergodic capacity and exact channel outage probability with space-time water-filling can be evaluated through numerical integrations, which can be further simplified by using approximated empirical eigenvalue and maximal eigenvalue distribution of MIMO fading channels. We also compare the performance of space-time water-filling with spatial water-filling. For MIMO channels with small shadowing effects, spatial water-filling performs very close to space-time water-filling in terms of ergodic capacity. For MIMO channels with large shadowing effects, however, space-time water-filling achieves significantly higher capacity per antenna than spatial water-filling at low to moderate SNR regimes, but with a much higher channel outage probability. We show that the analytical capacity and outage probability results agree very well with those obtained from Monte Carlo simulations.

  20. Lossless compression of medical images using Hilbert space-filling curves.

    Science.gov (United States)

    Liang, Jan-Yie; Chen, Chih-Sheng; Huang, Chua-Huang; Liu, Li

    2008-04-01

    A Hilbert space-filling curve is a curve traversing the 2(n) x 2(n)two-dimensional space and it visits neighboring points consecutively without crossing itself. The application of Hilbert space-filling curves in image processing is to rearrange image pixels in order to enhance pixel locality. A computer program of the Hilbert space-filling curve ordering generated from a tensor product formula is used to rearrange pixels of medical images. We implement four lossless encoding schemes, run-length encoding, LZ77 coding, LZW coding, and Huffman coding, along with the Hilbert space-filling curve ordering. Combination of these encoding schemes are also implemented to study the effectiveness of various compression methods. In addition, differential encoding is employed to medical images to study different format of image representation to the above encoding schemes. In the paper, we report the testing results of compression ratio and performance evaluation. The experiments show that the pre-processing operation of differential encoding followed by the Hilbert space-filling curve ordering and the compression method of LZW coding followed by Huffman coding will give the best compression result.

  1. A novel family of space-filling curves in their relation to chromosome conformation in eukaryotes

    Science.gov (United States)

    Smrek, Jan; Grosberg, Alexander Y.

    2013-12-01

    Spatial conformation of DNA chains during interphase in eukaryotic cell nucleus is relatively dense, yet unknotted and exhibits self-similar fractal properties. In this respect it resembles the space-filling curves of Hilbert, but differs in the experimentally accessible contact probability of distant loci. Here we construct space-filling curves with fractal domain boundaries of dimension close to that of the embedding space and show how these match the statistical properties and the contact probability of the DNA conformation. The present mathematical model should shed light on the statistical ensemble of unknotted dense polymers and ease the modeling of genome folding and related biological processes.

  2. 3D Hilbert Space Filling Curves in 3D City Modeling for Faster Spatial Queries

    DEFF Research Database (Denmark)

    Ujang, Uznir; Antón Castro, Francesc/François; Azri, Suhaibah

    2014-01-01

    objects. In this research, the authors propose an opponent data constellation technique of space-filling curves (3D Hilbert curves) for 3D city model data representation. Unlike previous methods, that try to project 3D or n-dimensional data down to 2D or 3D using Principal Component Analysis (PCA......) or Hilbert mappings, in this research, they extend the Hilbert space-filling curve to one higher dimension for 3D city model data implementations. The query performance was tested for single object, nearest neighbor and range search queries using a CityGML dataset of 1,000 building blocks and the results...... are presented in this paper. The advantages of implementing space-filling curves in 3D city modeling will improve data retrieval time by means of optimized 3D adjacency, nearest neighbor information and 3D indexing. The Hilbert mapping, which maps a sub-interval of the ([0,1]) interval to the corresponding...

  3. Evolutionary diversification, coevolution between populations and their antagonists, and the filling of niche space.

    Science.gov (United States)

    Ricklefs, Robert E

    2010-01-26

    The population component of a species' niche corresponds to the distribution of individuals across environments within a region. As evolutionary clades of species diversify, they presumably fill niche space, and, consequently, the rate of increase in species numbers slows. Total niche space and species numbers appear to be relatively stable over long periods, and so an increase in the species richness of one clade must be balanced by decrease in others. However, in several analyses, the total population niche space occupied per clade is independent of the number of species, suggesting that species in more diverse clades overlap more in niche space. This overlap appears to be accommodated by variation in the populations of each species, including their absence, within suitable niche space. I suggest that the uneven filling of niche space results from localized outcomes of the dynamic coevolutionary interactions of populations with their pathogens or other antagonists. Furthermore, I speculate that relationships with pathogens might constrain diversification if pathogen diversity increased with host diversity and resulted in more frequent host switching and emergent disease. Many indirect observations are consistent with these scenarios. However, the postulated influence of pathogens on the filling of niche space and diversification of clades primarily highlights our lack of knowledge concerning the space and time dimensions of coevolutionary interactions and their influence on population distribution and species diversification.

  4. Asymmetries arising from the space-filling nature of vascular networks

    Science.gov (United States)

    Hunt, David; Savage, Van M.

    2016-06-01

    Cardiovascular networks span the body by branching across many generations of vessels. The resulting structure delivers blood over long distances to supply all cells with oxygen via the relatively short-range process of diffusion at the capillary level. The structural features of the network that accomplish this density and ubiquity of capillaries are often called space-filling. There are multiple strategies to fill a space, but some strategies do not lead to biologically adaptive structures by requiring too much construction material or space, delivering resources too slowly, or using too much power to move blood through the system. We empirically measure the structure of real networks (18 humans and 1 mouse) and compare these observations with predictions of model networks that are space-filling and constrained by a few guiding biological principles. We devise a numerical method that enables the investigation of space-filling strategies and determination of which biological principles influence network structure. Optimization for only a single principle creates unrealistic networks that represent an extreme limit of the possible structures that could be observed in nature. We first study these extreme limits for two competing principles, minimal total material and minimal path lengths. We combine these two principles and enforce various thresholds for balance in the network hierarchy, which provides a novel approach that highlights the tradeoffs faced by biological networks and yields predictions that better match our empirical data.

  5. Improved gap filling method based on singular spectrum analysis and its application in space environment

    Science.gov (United States)

    Li, Xiangzhen; Liu, Shuai; Li, Zhi; Gong, Jiancun

    2017-11-01

    Data missing is a common phenomenon in the space environment measurements, which impacts or even blocks the following model-building procedures, predictions and posterior analysis. To fill these data gaps, an improved filling method based on iterative singular spectrum analysis is proposed. It first extracts a distribution array of the gaps and then fills the gaps with all known data. The distribution array is utilized to generate the test sets for cross validation. The embedding window length and principal components are determined by the discrete particle swarm optimization algorithm in a noncontinuous fashion. The effectiveness and adaptability of the filling method are proved by some tests done on solar wind data and geomagnetic indices from different solar activity years.

  6. Evolutionary diversification, coevolution between populations and their antagonists, and the filling of niche space

    OpenAIRE

    Ricklefs, Robert E.

    2010-01-01

    The population component of a species’ niche corresponds to the distribution of individuals across environments within a region. As evolutionary clades of species diversify, they presumably fill niche space, and, consequently, the rate of increase in species numbers slows. Total niche space and species numbers appear to be relatively stable over long periods, and so an increase in the species richness of one clade must be balanced by decrease in others. However, in several analyses, the total...

  7. Mechanical and molecular studies of biocomposites filled with oil palm empty fruit bunches microfibers

    Science.gov (United States)

    Nikmatin, S.; Saepulloh, D. R.; Irmansyah; Syafiuddin, A.

    2017-05-01

    The present work aims to investigate mechanical and molecular characteristics of acrylonitrile butadiene styrene (ABS) composites filled with oil palm empty fruit bunches (OPEFB) microfibers. OPEFB microfibers were produced using mechanical milling. Composite granules were fabricated using single screw extruder. These composites were then used for fabricating helmet according to the Indonesian National Standard (SNI). Mechanical testing confirms that the helmet produced using this biocomposites are suitable to the SNI. Molecular interaction between matrix with OPEFB can be described using orbital hybridization theory. In general, this study has successfully investigated mechanical and molecular properties of the biocomposites.

  8. Halftone information hiding technology based on phase feature of space filling curves

    Science.gov (United States)

    Hu, Jianhua; Cao, Peng; Dong, Zhihong; Cao, Xiaohe

    2017-08-01

    To solve the problems of the production of interference fringes (namely moiré in printing) and improve the image quality in printing process of halftone screening for information hiding, a halftone screening security technique based on the phase feature of space filling curves is studied in this paper. This method effectively solves the problem of moire and optimizes the quality of the screening, so that the images presented after screening have achieved good visual effect. The pseudo-random scrambling encryption of the plaintext information and the halftone screening technique based on the phase feature of the space filling curves are carried out when screening,which not only eliminates the common moire in the screening but also improves the image quality and the security of information.

  9. How tree species fill geographic and ecological space in eastern North America

    OpenAIRE

    Ricklefs, Robert E.

    2015-01-01

    Background and Aims Ecologists broadly accept that the number of species present within a region balances regional processes of immigration and speciation against competitive and other interactions between populations that limit distribution and constrain diversity. Although ecological theory has, for a long time, addressed the premise that ecological space can be filled to ‘capacity’ with species, only with the availability of time-calibrated phylogenies has it been possible to test the hypo...

  10. Ultrasound therapy transducers with space-filling non-periodic arrays.

    Science.gov (United States)

    Raju, Balasundar I; Hall, Christopher S; Seip, Ralf

    2011-05-01

    Ultrasound transducers designed for therapeutic purposes such as tissue ablation, histotripsy, or drug delivery require large apertures for adequate spatial localization while providing sufficient power and steerability without the presence of secondary grating lobes. In addition, it is highly preferred to minimize the total number of channels and to maintain simplicity in electrical matching network design. To this end, we propose array designs that are both space-filling and non-periodic in the placement of the elements. Such array designs can be generated using the mathematical concept of non-periodic or aperiodic tiling (tessellation) and can lead to reduced grating lobes while maintaining full surface area coverage to deliver maximum power. For illustration, we designed two 2-D space-filling therapeutic arrays with 128 elements arranged on a spherical shell. One was based on the two-shape Penrose rhombus tiling, and the other was based on a single rectangular shape arranged non-periodically. The steerability performance of these arrays was studied using acoustic field simulations. For comparison, we also studied two other arrays, one with circular elements distributed randomly, and the other a periodic array with square elements. Results showed that the two space-filling non-periodic arrays were able to steer to treat a volume of 16 x 16 x 20 mm while ensuring that the grating lobes were under -10 dB compared with the main lobe. The rectangular non-periodic array was able to generate two and half times higher power than the random circles array. The rectangular array was then fabricated by patterning the array using laser scribing methods and its steerability performance was validated using hydrophone measurements. This work demonstrates that the concept of space-filling aperiodic/non-periodic tiling can be used to generate therapy arrays that are able to provide higher power for the same total transducer area compared with random arrays while maintaining

  11. Transformation of the New Belgrade urban tissue: Filling the space instead of interpolation

    Directory of Open Access Journals (Sweden)

    Marić Igor

    2010-01-01

    Full Text Available This paper points to current transformations of the New Belgrade architectural and urban space identifying the process of filling the empty undeveloped areas within the New Belgrade blocks under the pressure of new commercial facilities. Given that these changes are not regulated by plans in an appropriate way, they are manifested in the space as problem situations leading to the production of space which is appropriate for the narrow interests of capital holders, while interests of direct users, as well as interest of a wider public, are most often neglected. The paper presents a critical analysis of the existing conditions and identifies problems emerging in the development and planning of the New Belgrade urban tissue. The space transformations have been explored at the level of urban and physical structure, urban landscape and user's life. Identified problem situations are indicative for further consideration of strategies for urban-architectural planning and design of New Belgrade.

  12. EXPERIMENTAL RESEARCH ON LATERAL PRESSURE OF GRANULAR MEDIA WITHIN CLOSELY SPACED WALLS CONSIDERING DIFFERENT FILLING CONDITIONS

    Directory of Open Access Journals (Sweden)

    Aleksej Aniskin

    2016-12-01

    Full Text Available This article presents the results of an original experimental research on the lateral pressure acting on closely spaced rigid walls at different angles of granular particle orientation to the horizontal line. Filling was performed at three different predominant angles of grain orientation with respect to the horizontal line: 0°, 45°, and 90°. The aim of the study is to determine the nature of the influence of the particle orientation achieved by filling on the characteristics and distribution of the lateral pressure. In the experiments, a composite medium, i.e. a mixture of quartz sand and flat shell particles in a volume ratio of 2:1, was used. The results of the experiments showed a significant difference in the lateral pressure at different angles of particle orientation. It was found that at an angle of 90°, the average lateral pressure was 44.2% more than that at an angle of 0°.

  13. Using a Space Filling Curve Approach for the Management of Dynamic Point Clouds

    Science.gov (United States)

    Psomadaki, S.; van Oosterom, P. J. M.; Tijssen, T. P. M.; Baart, F.

    2016-10-01

    Point cloud usage has increased over the years. The development of low-cost sensors makes it now possible to acquire frequent point cloud measurements on a short time period (day, hour, second). Based on the requirements coming from the coastal monitoring domain, we have developed, implemented and benchmarked a spatio-temporal point cloud data management solution. For this reason, we make use of the flat model approach (one point per row) in an Index Organised Table within a RDBMS and an improved spatio-temporal organisation using a Space Filling Curve approach. Two variants coming from two extremes of the space-time continuum are also taken into account, along with two treatments of the z dimension: as attribute or as part of the space filling curve. Through executing a benchmark we elaborate on the performance - loading and querying time -, and storage required by those different approaches. Finally, we validate the correctness and suitability of our method, through an out-of-the-box way of managing dynamic point clouds.

  14. A multifractal approach to space-filling recovery for PET quantification

    Energy Technology Data Exchange (ETDEWEB)

    Willaime, Julien M. Y., E-mail: julien.willaime@siemens.com; Aboagye, Eric O. [Comprehensive Cancer Imaging Centre, Imperial College London, Hammersmith Hospital, London W12 0NN (United Kingdom); Tsoumpas, Charalampos [Division of Medical Physics, University of Leeds, LS2 9JT (United Kingdom); Turkheimer, Federico E. [Department of Neuroimaging, Institute of Psychiatry, King’s College London, London SE5 8AF (United Kingdom)

    2014-11-01

    Purpose: A new image-based methodology is developed for estimating the apparent space-filling properties of an object of interest in PET imaging without need for a robust segmentation step and used to recover accurate estimates of total lesion activity (TLA). Methods: A multifractal approach and the fractal dimension are proposed to recover the apparent space-filling index of a lesion (tumor volume, TV) embedded in nonzero background. A practical implementation is proposed, and the index is subsequently used with mean standardized uptake value (SUV {sub mean}) to correct TLA estimates obtained from approximate lesion contours. The methodology is illustrated on fractal and synthetic objects contaminated by partial volume effects (PVEs), validated on realistic {sup 18}F-fluorodeoxyglucose PET simulations and tested for its robustness using a clinical {sup 18}F-fluorothymidine PET test–retest dataset. Results: TLA estimates were stable for a range of resolutions typical in PET oncology (4–6 mm). By contrast, the space-filling index and intensity estimates were resolution dependent. TLA was generally recovered within 15% of ground truth on postfiltered PET images affected by PVEs. Volumes were recovered within 15% variability in the repeatability study. Results indicated that TLA is a more robust index than other traditional metrics such as SUV {sub mean} or TV measurements across imaging protocols. Conclusions: The fractal procedure reported here is proposed as a simple and effective computational alternative to existing methodologies which require the incorporation of image preprocessing steps (i.e., partial volume correction and automatic segmentation) prior to quantification.

  15. A Simple and Effective Clustering Algorithm for Multispectral Images Using Space-Filling Curves

    Science.gov (United States)

    Zhang, Jian; Kamata, Sei-Ichiro

    With the wide usage of multispectral images, a fast efficient multidimensional clustering method becomes not only meaningful but also necessary. In general, to speed up the multidimensional images' analysis, a multidimensional feature vector should be transformed into a lower dimensional space. The Hilbert curve is a continuous one-to-one mapping from N-dimensional space to one-dimensional space, and can preserves neighborhood as much as possible. However, because the Hilbert curve is generated by a recurve division process, ‘Boundary Effects’ will happen, which means data that are close in N-dimensional space may not be close in one-dimensional Hilbert order. In this paper, a new efficient approach based on the space-filling curves is proposed for classifying multispectral satellite images. In order to remove ‘Boundary Effects’ of the Hilbert curve, multiple Hilbert curves, z curves, and the Pseudo-Hilbert curve are used jointly. The proposed method extracts category clusters from one-dimensional data without computing any distance in N-dimensional space. Furthermore, multispectral images can be analyzed hierarchically from coarse data distribution to fine data distribution in accordance with different application. The experimental results performed on LANDSAT data have demonstrated that the proposed method is efficient to manage the multispectral images and can be applied easily.

  16. Improved Fractal Space Filling Curves Hybrid Optimization Algorithm for Vehicle Routing Problem

    Directory of Open Access Journals (Sweden)

    Yi-xiang Yue

    2015-01-01

    Full Text Available Vehicle Routing Problem (VRP is one of the key issues in optimization of modern logistics system. In this paper, a modified VRP model with hard time window is established and a Hybrid Optimization Algorithm (HOA based on Fractal Space Filling Curves (SFC method and Genetic Algorithm (GA is introduced. By incorporating the proposed algorithm, SFC method can find an initial and feasible solution very fast; GA is used to improve the initial solution. Thereafter, experimental software was developed and a large number of experimental computations from Solomon’s benchmark have been studied. The experimental results demonstrate the feasibility and effectiveness of the HOA.

  17. Improved Fractal Space Filling Curves Hybrid Optimization Algorithm for Vehicle Routing Problem.

    Science.gov (United States)

    Yue, Yi-xiang; Zhang, Tong; Yue, Qun-xing

    2015-01-01

    Vehicle Routing Problem (VRP) is one of the key issues in optimization of modern logistics system. In this paper, a modified VRP model with hard time window is established and a Hybrid Optimization Algorithm (HOA) based on Fractal Space Filling Curves (SFC) method and Genetic Algorithm (GA) is introduced. By incorporating the proposed algorithm, SFC method can find an initial and feasible solution very fast; GA is used to improve the initial solution. Thereafter, experimental software was developed and a large number of experimental computations from Solomon's benchmark have been studied. The experimental results demonstrate the feasibility and effectiveness of the HOA.

  18. Residual Endodontic Filling Material after Post Space Preparation: A Confocal Microscopic Study.

    Science.gov (United States)

    Teoh, Yu-Yao; Walsh, Laurence J

    2017-11-21

    This laboratory study assessed removability of endodontic alkaline cements and resin sealers using coronal cross-sectional slices of roots with single canals. Materials were labelled with 0.1% (w/w) sodium fluorescein prior to mixing so that confocal microscopy could be used to quantify material remaining on the walls of post spaces, to assess cleanliness. Roots of extracted teeth were prepared using rotary NiTi instruments then obturated using lateral condensation with gutta percha and epoxy resin sealers (AH-Plus™ or Zirmix™), or were filled by injecting mineral trioxide aggregate (MTA) cement (GC Nex™ MTA or MTAmix™) or a hard-setting calcium hydroxide cement (Supercal™). Brown (#3) ParaPost™ drills were used at 600 rpm with a torque setting of 3 N cm-1 for 2 min to remove 5 mm of the root filling. Roots were embedded and coronal slices examined by confocal microscopy, with the perimeter of the drill channel divided into clean, unclean and non-accessible regions. The choice of material affects cleanliness, with MTA being the most difficult and calcium hydroxide cement the easiest to remove. With epoxy resin-based sealers, almost half of the accessible canal walls remained coated with remnants of sealer after post space preparation.

  19. Exhaustive geographic search with mobile robots along space-filling curves

    Energy Technology Data Exchange (ETDEWEB)

    Spires, S.V.; Goldsmith, S.Y.

    1998-03-01

    Swarms of mobile robots can be tasked with searching a geographic region for targets of interest, such as buried land mines. The authors assume that the individual robots are equipped with sensors tuned to the targets of interest, that these sensors have limited range, and that the robots can communicate with one another to enable cooperation. How can a swarm of cooperating sensate robots efficiently search a given geographic region for targets in the absence of a priori information about the target`s locations? Many of the obvious approaches are inefficient or lack robustness. One efficient approach is to have the robots traverse a space-filling curve. For many geographic search applications, this method is energy-frugal, highly robust, and provides guaranteed coverage in a finite time that decreases as the reciprocal of the number of robots sharing the search task. Furthermore, it minimizes the amount of robot-to-robot communication needed for the robots to organize their movements. This report presents some preliminary results from applying the Hilbert space-filling curve to geographic search by mobile robots.

  20. Bells Galore: Oscillations and circle-map dynamics from space-filling fractal functions

    Energy Technology Data Exchange (ETDEWEB)

    Puente, C.E.; Cortis, A.; Sivakumar, B.

    2008-10-15

    The construction of a host of interesting patterns over one and two dimensions, as transformations of multifractal measures via fractal interpolating functions related to simple affine mappings, is reviewed. It is illustrated that, while space-filling fractal functions most commonly yield limiting Gaussian distribution measures (bells), there are also situations (depending on the affine mappings parameters) in which there is no limit. Specifically, the one-dimensional case may result in oscillations between two bells, whereas the two-dimensional case may give rise to unexpected circle map dynamics of an arbitrary number of two-dimensional circular bells. It is also shown that, despite the multitude of bells over two dimensions, whose means dance making regular polygons or stars inscribed on a circle, the iteration of affine maps yields exotic kaleidoscopes that decompose such an oscillatory pattern in a way that is similar to the many cases that converge to a single bell.

  1. The Application of a Three-Dimensional Printed Product to Fill the Space After Organ Removal.

    Science.gov (United States)

    Weng, Jui-Yu; Wang, Che-Chuna; Chen, Pei-Jar; Lim, Sher-Wei; Kuo, Jinn-Rung

    2017-11-01

    Maintaining body integrity, especially in Asian societies, is an independent predictor of organ donation. Herein, we report the case of an 18-year-old man who suffered a traumatic brain injury with ensuing brain death caused by a car accident. According to the family's wishes, we used a 3-dimensional printer to create simulated heart, kidneys, and liver to fill the spaces after the patient's organs were removed. This is the first case report to introduce this new clinical application of 3-dimensional printed products during transplantation surgery. This new clinical application may have supportive psychological effects on the family and caregivers; however, given the varied responses to our procedure, this ethical issue is worth discussing. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Using Peano-Hilbert space filling curves for fast bidimensional ensemble EMD realization

    Science.gov (United States)

    Costa, Paulo; Barroso, João; Fernandes, Hugo; Hadjileontiadis, Leontios J.

    2012-12-01

    Empirical mode decomposition (EMD) is a fully unsupervised and data-driven approach to the class of nonlinear and non-stationary signals. A new approach is proposed, namely PHEEMD, to image analysis by using Peano-Hilbert space filling curves to transform 2D data (image) into 1D data, followed by ensemble EMD (EEMD) analysis, i.e., a more robust realization of EMD based on white noise excitation. Tests' results have shown that PHEEMD exhibits a substantially reduced computational cost compared to other 2D-EMD approaches, preserving, simultaneously, the information lying at the EMD domain; hence, new perspectives for its use in low computational power devices, like portable applications, are feasible.

  3. How tree species fill geographic and ecological space in eastern North America.

    Science.gov (United States)

    Ricklefs, Robert E

    2015-05-01

    Ecologists broadly accept that the number of species present within a region balances regional processes of immigration and speciation against competitive and other interactions between populations that limit distribution and constrain diversity. Although ecological theory has, for a long time, addressed the premise that ecological space can be filled to 'capacity' with species, only with the availability of time-calibrated phylogenies has it been possible to test the hypothesis that diversification slows as the number of species in a region increases. Focusing on the deciduous trees of eastern North America, this study tested predictions from competition theory concerning the distribution and abundance of species. Local assemblages of trees tabulated in a previous study published in 1950 were analysed. Assemblages were ordinated with respect to species composition by non-metric multidimensional scaling (NMS). Distributions of trees were analysed by taxonomically nested analysis of variance, discriminant analysis based on NMS scores, and canonical correlation analysis of NMS scores and Bioclim climate variables. Most of the variance in species abundance and distribution was concentrated among closely related (i.e. congeneric) species, indicating evolutionary lability. Species distribution and abundance were unrelated to the number of close relatives, suggesting that competitive effects are diffuse. Distances between pairs of congeneric species in NMS space did not differ significantly from distances between more distantly related species, in contrast to the predictions of both competitive habitat partitioning and ecological sorting of species. Eastern deciduous forests of North America do not appear to be saturated with species. The distributions and abundances of individual species provide little evidence of being shaped by competition from related (i.e. ecologically similar) species and, by inference, that diversification is constrained by interspecific

  4. GPU computing of compressible flow problems by a meshless method with space-filling curves

    Science.gov (United States)

    Ma, Z. H.; Wang, H.; Pu, S. H.

    2014-04-01

    A graphic processing unit (GPU) implementation of a meshless method for solving compressible flow problems is presented in this paper. Least-square fit is used to discretize the spatial derivatives of Euler equations and an upwind scheme is applied to estimate the flux terms. The compute unified device architecture (CUDA) C programming model is employed to efficiently and flexibly port the meshless solver from CPU to GPU. Considering the data locality of randomly distributed points, space-filling curves are adopted to re-number the points in order to improve the memory performance. Detailed evaluations are firstly carried out to assess the accuracy and conservation property of the underlying numerical method. Then the GPU accelerated flow solver is used to solve external steady flows over aerodynamic configurations. Representative results are validated through extensive comparisons with the experimental, finite volume or other available reference solutions. Performance analysis reveals that the running time cost of simulations is significantly reduced while impressive (more than an order of magnitude) speedups are achieved.

  5. Fast solution of geophysical inversion using adaptive mesh, space-filling curves and wavelet compression

    Science.gov (United States)

    Davis, Kristofer; Li, Yaoguo

    2011-04-01

    Many geophysical inverse problems involve large and dense coefficient matrices that often exceed the limitations of physical memory in commonly available computers. The repeated multiplications of such matrices to vectors during processing or inversion require an immense amount of computing power. These two factors pose a significant challenge to solving large-scale inverse problems in practice and can render many realistic problems intractable. To overcome these limitations, we develop a new computational approach for this class of problems by combining an adaptive quadtree or octree model discretization and wavelet transforms on reordered parameter sets. The adaptive mesh discretizes the model region according to the required resolutions based on localized anomalies. Hilbert space-filling curves and similar ordering of the reduced parameter set then enable a higher compression of the coefficient matrix by forming its sparse representation in the 1-D wavelet domain. This combination can reduce the storage requirement by 100 to 1000 times and, therefore, also speeds up the computation during the processing stage by the same factor. As a result, problems can now be solved that were computationally prohibitive. We present the algorithm and illustrate its effectiveness with an example from equivalent source construction in potential-field processing.

  6. ON THE SAMPLING OF SERIAL SECTIONING TECHNIQUE FOR THREE DIMENSIONAL SPACE-FILLING GRAIN STRUCTURES

    Directory of Open Access Journals (Sweden)

    Guoquan Liu

    2011-05-01

    Full Text Available Serial sectioning technique provides plenty of quantitative geometric information of the microstructure analyzed, including those unavailable from stereology with one- and two-dimensional probes. This may be why it used to be and is being continuously served as one of the most common and invaluable methods to study the size and the size distribution, the topology and the distribution of topology parameters, and even the shape of three-dimensional space filling grains or cells. On the other hand, requiring tedious lab work, the method is also very time and energy consuming, most often only less than one hundred grains per sample were sampled and measured in almost all reported practice. Thus, a question is often asked: for typical microstructures in engineering materials, are so many grains or cells sampled adequate to obtain reliable results from this technique? To answer this question, experimental data of 1292 contiguous austenite grains in a low-carbon steel specimen obtained from the serial sectioning analysis are presented in this paper, which demonstrates the effect of sampling on the measurement of various parameters of grain size distribution and of the grain topology distribution. The result provides one of rules of thumb for grain stereology of similar microstructures.

  7. Space Charge Effects in Single Molecular Devices

    Science.gov (United States)

    Dunlap, David H.; Malliaras, George G.

    2002-03-01

    Strong negative differential resistance (NDR) has been recently observed in p-conjugated oligo (phenyleneethynylene) single-molecular devices consisting of two parallel metal (Au) electrodes which are separated by a self-assembled monolayer having a thickness on the order of 2nm [1]. The sudden drop in current suggests that nonlinear feedback associated electron transport through intermediate molecular states may be responsible for the observed NDR. We propose that the transfer of charge from the cathode to the anode takes place via nearest-neighbor hopping between two weakly coupled oligomer states. In such a case, the current is highest when the energies of the two states are coincident, and is suppressed when the voltage drop between them is sufficient to take them far out of resonance. The modification of the voltages within the junction due to accumulated space charge causes the states to become pinned. We show that this collective behavior enhances the abruptness of the NDR, and under appropriate circumstances leads to a triangularly shaped hysteresis loop in the current-voltage relation. [1] M. A. Reed, J. Chen, W. Wang, D. W. Price, A. M. Rawlett, and J. M. Tour, Appl. Phys. Lett 78, 3735 (2001)

  8. Improving 3D spatial queries search: newfangled technique of space filling curves in 3D city modeling

    DEFF Research Database (Denmark)

    Uznir, U.; Anton, François; Suhaibah, A.

    2013-01-01

    . In this research, we propose an opponent data constellation technique of space-filling curves (space-filling curve) for 3D city model data representation. Unlike previous methods, that try to project 3D or n-dimensional data down to 2D or 3D using Principal Component Analysis (PCA) or Hilbert mappings......, in this research, we extend the Hilbert space-filling curve to one higher dimension for 3D city model data implementations. The query performance was tested using a CityGML dataset of 1,000 building blocks and the results are presented in this paper. The advantages of implementing space-filling curves in 3D city...... modeling will improve data retrieval time by means of optimized 3D adjacency, nearest neighbor information and 3D indexing. The Hilbert mapping, which maps a subinterval of the [0, 1] interval to the corresponding portion of the d-dimensional Hilbert’s curve, preserves the Lebesgue measure and is Lipschitz...

  9. Groundwater Monitoring Network Design Using a Space-Filling/ Bias-Reduction Heuristic

    Science.gov (United States)

    Yan, T.; Singh, A.; Kelley, V.; Deeds, N.

    2012-12-01

    Groundwater monitoring network design is one of the primary goals of groundwater management. In this study, a heuristic method for selecting wells to monitor groundwater flow is developed. The approach selects wells to a) maximize spread within the monitoring area (space-filling objective), b) reduce bias in estimate of groundwater level (drawdown objective) by selecting pairs of well proximal and distant from pumping areas. By selecting pairs of monitoring wells, this method is able to capture the largest and smallest drawdown in the study area while ensuring the newly added monitoring wells are at the greatest distance from existing monitoring wells. One of the advantages of this method is that it does not require water level information, obtained either from field measurements or groundwater model runs, which might be unavailable at the time of the monitoring network design; instead, this method utilizes pumping rates and locations thus can take future planning into consideration. If water level data is available then that may be included by considering it in the drawdown objective. A FORTRAN code is developed to implement this method. By changing the weighting factors, users have the flexibility on deciding the importance of pumping and spatial information to their network designs. The method has been successfully applied to monitoring network design in Upper Trinity County Groundwater Conservation District in Texas. Monitoring wells were selected from thousands of existing wells and added to the current monitoring network. The results support the decision maker on the number and distribution of a new groundwater network using existing wells. The study can be extended to improve the application of desired future condition (DFC) for Groundwater Conservation Districts in Texas.

  10. Molecular and morphological surface analysis: effect of filling pastes and cleaning agents on root dentin

    Directory of Open Access Journals (Sweden)

    Vanessa Benetello DAINEZI

    Full Text Available Abstract The quality of the dentin root is the most important factor for restoration resin sealing and drives the outcome of endodontic treatment. Objective This study evaluated the effect of different filling pastes and cleaning agents on the root dentin of primary teeth using Fourier-transformed Raman spectroscopy (FT-Raman, micro energy-dispersive X-ray fluorescence (µ-EDXRF and scanning electron microscopic (SEM analysis. Material and Methods Eighty roots of primary teeth were endodontically prepared and distributed into 4 groups and filled according to the following filling pastes: Control-no filling (CP, Calen®+zinc oxide (CZ, Calcipex II® (CII, Vitapex® (V. After seven days, filling paste groups were distributed to 4 subgroups according to cleaning agents (n=5: Control-no cleaning (C, Ethanol (E, Tergenform® (T, 35% Phosphoric acid (PA. Then, the roots were sectioned and the dentin root sections were internally evaluated by FT-Raman, µ-EDXRF and SEM. Data was submitted to two-way ANOVA and Tukey tests (α=0.05. Results Regarding filling pastes, there was no significant difference in organic content. CP provided the lowest calcium values and, calcium/phosphoric ratio (Ca/P, and the highest phosphoric values. For cleaning agents there was no difference in organic content when compared to the C; however, T showed significantly higher calcium and Ca/P than PA. All groups showed similar results for phosphorus. The dentin smear layer was present after use of the cleaning agents, except PA. Conclusion The filling pastes changed the inorganic content, however they did not change the organic content. Cleaning agents did not alter the inorganic and organic content. PA cleaned and opened dentin tubules.

  11. Sealing efficacy of a single-cone root filling after post space preparation

    NARCIS (Netherlands)

    Sungur, D.D.; Moinzadeh, A.T.; Wesselink, P.R.; Tarhan, S.C.; Özok, A.R.

    2016-01-01

    Objectives The aim of the present study was to compare the sealing efficacy of root fillings made by a single-cone technique with three different sealers and a cold lateral compaction technique with an epoxy sealer. Materials and methods Eighty extracted single-rooted human teeth were assigned to

  12. THE USE OF CUSTOMIZED GUTTA PERCHA FILLING MATERIAL IN WIDE ROOT CANAL SPACE

    Directory of Open Access Journals (Sweden)

    Dewa Ayu N. P. A. Dewa Ayu

    2006-04-01

    Full Text Available The necrotic tooth with incomplete formed roots and wide root canal should be treated by apexification. Gutta-percha combined with root canal sealer is widely used as an obturation material. The aim of this case report is to figure out that the use of customized gutta-percha in wide root canal to produce compact and hermetic filling.

  13. Healing process of dog teeth after post space preparation and exposition of the filling material to the oral environment

    Directory of Open Access Journals (Sweden)

    Barbosa Henrian Gonzaga

    2003-01-01

    Full Text Available The purpose of this study was to observe the influence of coronal leakage on the behavior of periapical tissues after root canal filling and post space preparation. Forty root canals of dogs' teeth were instrumented and filled by the lateral condensation technique with gutta percha points and the cements Sealer 26 and Roth. After post space preparation, the remaining filling material was either protected or not protected with a plug of the temporary cement Lumicon. After root canal exposition to the oral environment for 90 days, the animals were killed and specimens were removed and prepared for histomorphological analysis. The Brown and Brenn technique showed 70% of cases with microorganism leakage for Roth cement, and 20% with Sealer 26. When a plug of Lumicon was employed, there was 30% leakage for Roth cement and 0% for Sealer 26. A chronic inflammatory reaction was more frequently observed with Roth cement than with Sealer 26. It was concluded that a plug of Lumicon was efficient in controlling microorganism coronal leakage (p=0.05, and that Sealer 26 was more biocompatible and sealed root canals better than Roth sealer (p=0.01.

  14. Efficient small molecule bulk heterojunction solar cells with high fill factors via pyrene-directed molecular self-assembly

    KAUST Repository

    Lee, Olivia P.

    2011-10-21

    Efficient organic photovoltaic (OPV) materials are constructed by attaching completely planar, symmetric end-groups to donor-acceptor electroactive small molecules. Appending C2-pyrene as the small molecule end-group to a diketopyrrolopyrrole core leads to materials with a tight, aligned crystal packing and favorable morphology dictated by π-π interactions, resulting in high power conversion efficiencies and high fill factors. The use of end-groups to direct molecular self-assembly is an effective strategy for designing high-performance small molecule OPV devices. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Improving 3d Spatial Queries Search: Newfangled Technique of Space Filling Curves in 3d City Modeling

    Science.gov (United States)

    Uznir, U.; Anton, F.; Suhaibah, A.; Rahman, A. A.; Mioc, D.

    2013-09-01

    The advantages of three dimensional (3D) city models can be seen in various applications including photogrammetry, urban and regional planning, computer games, etc.. They expand the visualization and analysis capabilities of Geographic Information Systems on cities, and they can be developed using web standards. However, these 3D city models consume much more storage compared to two dimensional (2D) spatial data. They involve extra geometrical and topological information together with semantic data. Without a proper spatial data clustering method and its corresponding spatial data access method, retrieving portions of and especially searching these 3D city models, will not be done optimally. Even though current developments are based on an open data model allotted by the Open Geospatial Consortium (OGC) called CityGML, its XML-based structure makes it challenging to cluster the 3D urban objects. In this research, we propose an opponent data constellation technique of space-filling curves (3D Hilbert curves) for 3D city model data representation. Unlike previous methods, that try to project 3D or n-dimensional data down to 2D or 3D using Principal Component Analysis (PCA) or Hilbert mappings, in this research, we extend the Hilbert space-filling curve to one higher dimension for 3D city model data implementations. The query performance was tested using a CityGML dataset of 1,000 building blocks and the results are presented in this paper. The advantages of implementing space-filling curves in 3D city modeling will improve data retrieval time by means of optimized 3D adjacency, nearest neighbor information and 3D indexing. The Hilbert mapping, which maps a subinterval of the [0, 1] interval to the corresponding portion of the d-dimensional Hilbert's curve, preserves the Lebesgue measure and is Lipschitz continuous. Depending on the applications, several alternatives are possible in order to cluster spatial data together in the third dimension compared to its

  16. Molecular Gas-Filled Hollow Optical Fiber Lasers in the Near Infrared

    Science.gov (United States)

    2012-01-12

    Wavelength (m) 10000 R(11)P(13) 10100 P(13) 00100 00000 M gO : PPLN Tunable CW laser ns OPA @ ~1.5 m ns N d:YA G PCF Gas Filled Chambers 3 m...output OPGL spectrometer PD or M gO : PPLN ns N d:YA G Fig. 3 a) Setup used for both the C2H2 and HCN (see below) gas lasers at K-State. b) The...Both beams are coupled into a 50 mm length periodically poled lithium niobate ( PPLN ) crystal doped with MgO2, which increases the nonlinearity. The

  17. Isothermal close space sublimation for II-VI semiconductor filling of porous matrices

    Science.gov (United States)

    2012-01-01

    Isothermal close space sublimation, a simple and low-cost physical vapour transport technique, was used to infiltrate ZnTe and CdSe semiconductors in porous silicon. The structure of the embedded materials was determined by X-ray diffraction analysis while Rutherford backscattering spectra allowed determining the composition profiles of the samples. In both cases, a constant composition of the II-VI semiconductors throughout the porous layer down to the substrate was found. Resonance Raman scattering of the ZnTe samples indicates that this semiconductor grows in nanostructured form inside the pores. Results presented in this paper suggest that isothermal close space sublimation is a promising technique for the conformal growth of II-VI semiconductors in porous silicon. PMID:22823959

  18. Basic examination of a technique to visualize space filled with dense smoke using millimeter-wave radar

    Science.gov (United States)

    Omine, Yukio; Sakai, Masaki; Aoki, Yoshimitsu; Takagi, Mikio

    2004-10-01

    In recent years, crisis management in response to terrorist attacks and natural disasters, as well as accelerating rescue operations has become an important issue. Rescue operations greatly influence human lives, and require the ability to accurately and swiftly communicate information as well as assess the status of the site. Currently, considerable amount of research is being conducted for assisting rescue operations, with the application of various engineering techniques such as information technology and radar technology. In the present research, we believe that assessing the status of the site is most crucial in rescue and firefighting operations at a fire disaster site, and aim to visualize the space that is smothered with dense smoke. In a space filled with dense smoke, where visual or infrared sensing techniques are not feasible, three-dimensional measurements can be realized using a compact millimeter wave radar device combined with directional information from a gyro sensor. Using these techniques, we construct a system that can build and visualize a three-dimensional geometric model of the space. The final objective is to implement such a system on a wearable computer, which will improve the firefighters' spatial perception, assisting them in the baseline assessment and the decision-making process. In the present paper, we report the results of the basic experiments on three-dimensional measurement and visualization of a space that is smoke free, using a millimeter wave radar.

  19. Enhanced sensitivity to near-infrared with high fill factor in small molecular organic solar cells

    Science.gov (United States)

    Shim, Hyun-Sub; Kim, Hyo Jung; Kim, Ji Whan; Kim, Sei-Yong; Jeong, Won-Ik; Kim, Tae-Min; Kim, Jang-Joo

    2012-09-01

    High efficiency near-infrared (NIR) absorbing solar cells based on lead phthalocyanine (PbPc) are reported using copper iodide (CuI) as a templating layer to control the crystal structure of PbPc. Devices with CuI inserted between the ITO and PbPc layers exhibit a two times enhancement of the JSC compared to the case in the absence of the CuI layer. This is due to the increase of crystallinity in the molecules grown on the CuI templating layer, which is investigated via an x-ray diffraction study. Moreover, fill factor is also enhanced to 0.63 from 0.57 due to low series resistance although the additional CuI layer is inserted between the ITO and the PbPc layer. As a result, the corrected power conversion efficiency of 2.5% was obtained, which is the highest one reported up to now among the PbPc based solar cells.

  20. Influence of partial k-space filling on the quality of magnetic resonance images

    Directory of Open Access Journals (Sweden)

    Tiago da Silva Jornada

    2016-06-01

    Full Text Available Abstract Objective: To study the influence that the scan percentage tool used in partial k-space acquisition has on the quality of images obtained with magnetic resonance imaging equipment. Materials and Methods: A Philips 1.5 T magnetic resonance imaging scanner was used in order to obtain phantom images for quality control tests and images of the knee of an adult male. Results: There were no significant variations in the uniformity and signal-to-noise ratios with the phantom images. However, analysis of the high-contrast spatial resolution revealed significant degradation when scan percentages of 70% and 85% were used in the acquisition of T1- and T2-weighted images, respectively. There was significant degradation when a scan percentage of 25% was used in T1- and T2-weighted in vivo images (p ≤ 0.01 for both. Conclusion: The use of tools that limit the k-space is not recommended without knowledge of their effect on image quality.

  1. A comparative molecular analysis of water-filled limestone sinkholes in north-eastern Mexico.

    Science.gov (United States)

    Sahl, Jason W; Gary, Marcus O; Harris, J Kirk; Spear, John R

    2011-01-01

    Sistema Zacatón in north-eastern Mexico is host to several deep, water-filled, anoxic, karstic sinkholes (cenotes). These cenotes were explored, mapped, and geochemically and microbiologically sampled by the autonomous underwater vehicle deep phreatic thermal explorer (DEPTHX). The community structure of the filterable fraction of the water column and extensive microbial mats that coat the cenote walls was investigated by comparative analysis of small-subunit (SSU) 16S rRNA gene sequences. Full-length Sanger gene sequence analysis revealed novel microbial diversity that included three putative bacterial candidate phyla and three additional groups that showed high intra-clade distance with poorly characterized bacterial candidate phyla. Limited functional gene sequence analysis in these anoxic environments identified genes associated with methanogenesis, sulfate reduction and anaerobic ammonium oxidation. A directed, barcoded amplicon, multiplex pyrosequencing approach was employed to compare ∼100,000 bacterial SSU gene sequences from water column and wall microbial mat samples from five cenotes in Sistema Zacatón. A new, high-resolution sequence distribution profile (SDP) method identified changes in specific phylogenetic types (phylotypes) in microbial mats at varied depths; Mantel tests showed a correlation of the genetic distances between mat communities in two cenotes and the geographic location of each cenote. Community structure profiles from the water column of three neighbouring cenotes showed distinct variation; statistically significant differences in the concentration of geochemical constituents suggest that the variation observed in microbial communities between neighbouring cenotes are due to geochemical variation. © 2010 Society for Applied Microbiology and Blackwell Publishing Ltd.

  2. Role of surfactant molecular weight on morphology and properties of functionalized graphite oxide filled polypropylene nanocomposites

    Directory of Open Access Journals (Sweden)

    Y. Wang

    2014-12-01

    Full Text Available Various surfactants of different molecular weights, including alkylamine, poly(oxypropylene diamine (POP, and maleic anhydride grafted polypropylene (PPgMA oligomers, were used for simultaneous funtionalization and reduction of graphite oxide (fGO. In this study, the effect of molecular weight and compatibility of the surfactants on the morphology and properties of the nanocomposites are reported. Wide-angle X-ray diffraction (WAXD exhibited a definite interlayer thickness for GOA (alkylamine intercalated GO, however, the diffraction peaks were nearly suppressed for fGOs combining ODA with either POP (GOAP or PPgMA (GOAE. The uniform dispersion of the fGO flakes in the polypropylene matrix resulted in the significant increase in both the degradation temperature and the crystallization temperature. A single characteristic melting peak of monoclinic (α crystalline phase was observed from DSC traces, which was consistent with WAXD results. Dynamic mechanical analysis clearly indicated increase in both the storage modulus and the glass transition temperature of the nanocomposites due to the enhanced affinity between fGO and the polypropylene matrix. However, GOAP composite showed lower E' and Tg than GOAE because POP is less compatible with the matrix than PPgMA oligomer. Dielectric analysis also showed significant increase in both dielectric permittivity and dielectric loss at low frequency regimes with GOAE showing maximum dielectric properties. The finely dispersed GOAE and its compatibility with polymer matrix manifested the interfacial polarization, which gave rise to much greater ε' and ε" than other nanocomposites.

  3. Influence of the length of remaining root canal filling and post space preparation on the coronal leakage of Enterococcus faecalis.

    Science.gov (United States)

    Mozini, Alexandra Conca Alves; Vansan, Luis P; Sousa Neto, Manoel D; Pietro, Rosimeire

    2009-01-01

    This study evaluated the sealing ability of different lengths of remaining root canal filling and post space preparation against coronal leakage of Enterococcus faecalis. Forty-one roots of maxillary incisors were biomechanically prepared, maintaining standardized canal diameter at the middle and coronal thirds. The roots were autoclaved and all subsequent steps were undertaken in a laminar flow chamber. The canals of 33 roots were obturated with AH Plus sealer and gutta-percha. The root canal fillings were reduced to 3 predetermined lengths (n=11): G1=6 mm, G2=4 mm and G3=2 mm. The remaining roots served as positive and negative controls. Bacterial leakage test apparatuses were fabricated with the roots attached to Eppendorf tubes keeping 2 mm of apex submerged in BHI in glass flasks. The specimens received an E. faecalis inoculum of 1 x 107 cfu/mL every 3 days and were observed for bacterial leakage daily during 60 days. Data were submitted to ANOVA, Tukey's test and Fisher's test. At 60 days, G1 (6 mm) and G2 (4 mm) presented statistically similar results (p>0.05) (54.4% of specimens with bacterial leakage) and both groups differed significantly (pendodontic obturation remnant leaked considerably more than the other lengths, although none of the tested conditions avoids coronal leakage of E. faecalis.

  4. Automatic data distribution and load balancing with space-filling curves: implementation in CONQUEST

    Science.gov (United States)

    Brázdová, V.; Bowler, D. R.

    2008-07-01

    We present an automatic, spatially local data distribution and load balancing scheme applicable to many-body problems running on parallel architectures. The particle distribution is based on spatial decomposition of the simulation cell. A one-dimensional Hilbert curve is mapped onto the three-dimensional real space cell, which reduces the dimensionality of the problem and provides a way to assign different spatially local parts of the cell to each processor. The scheme is independent of the number of processors. It can be used for both ordered and disordered structures and does not depend on the dimensionality or shape of the system. Details of implementation in the linear-scaling density functional code CONQUEST, as well as several case studies of systems of various complexity, containing up to 55 755 particles, are given.

  5. Molecular and structural properties of polymer composites filled with activated charcoal particles

    Energy Technology Data Exchange (ETDEWEB)

    Tahir, Dahlang, E-mail: dtahir@fmipa.unhas.ac.id; Bakri, Fahrul [Department of Physics, Hasanuddin University, Makassar 90245 Indonesia (Indonesia); Liong, Syarifuddin [Department of Chemistry, Hasanuddin University, Makassar 90245 Indonesia (Indonesia)

    2016-03-11

    We have studied the molecular properties, structural properties, and chemical composition of composites by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) spectroscopy, and X-ray fluorescence (XRF) spectroscopy, respectively. FTIR spectra shows absorption band of hydroxyl group (-OH), methyl group (-CH{sub 3}) and aromatic group (C-C). The absorption band for aromatic group (C-C) shows the formation of carbonaceous in composites. XRF shows chemical composition of composites, which the main chemicals are SO{sub 3}, Cl, and ZnO. The loss on ignition value (LOI) of activated charcoal indicates high carbonaceous matter. The crystallite size for diffraction pattern from hydrogel polymer is about 17 nm and for activated charcoal are about 19 nm. The crystallite size of the polymer is lower than that of activated charcoal, which make possible of the particle from filler in contact with each other to form continuous conducting polymer through polymer matrix.

  6. Filling the gap in the European administrative space: the role of administrative networks in EU implementation and enforcement

    DEFF Research Database (Denmark)

    Martinsen, Dorte Sindbjerg; Mastenbroek, Ellen

    2017-01-01

    European administrative networks (EANs) are a key building block of the European Administrative Space (EAS). Crucially, they are to fill the gap between the EU’s policy ambitions and its limited administrative capacities. Whereas ample research has been done on policy preparation networks, the role......, it reports divergent findings on EAN establishment, functioning and impact, as well as variant normative evaluations. These variant findings partly relate to a lack of comparative research, selective policy coverage and predominant focus on North-western states. We conclude by suggesting a number of lines...... for future research on these four important themes, arguing that the crucial question will be which impact these EANs have on the national implementation and enforcement of EU law....

  7. Controllable deformation of salt water-filled carbon nanotubes using an electric field with application to molecular sieving

    Science.gov (United States)

    Ye, Hongfei; Zheng, Yonggang; Zhang, Zhongqiang; Zhang, Hongwu; Chen, Zhen

    2016-08-01

    Precisely controlling the deformation of carbon nanotubes (CNTs) has practical application in the development of nanoscale functional devices, although it is a challenging task. Here, we propose a novel method to guide the deformation of CNTs through filling them with salt water and applying an electric field. With the electric field along the axial direction, the height of CNTs is enlarged by the axial electric force due to the internal ions and polar water molecules. Under an electric field with two mutually orthogonal components, the transverse electric force could further induce the bending deformation of CNTs. Based on the classical rod and beam theories, two mechanical models are constructed to verify and quantitatively describe the relationships between the tension and bending deformations of CNTs and the electric field intensity. Moreover, by means of the electric field-driven tension behavior of CNTs, we design a stretchable molecular sieve to control the flow rate of mixed gas and collect a single high-purity gas. The present work opens up new avenues in the design and fabrication of nanoscale controlling units.

  8. Soil atmosphere exchange of carbonyl sulfide (COS regulated by diffusivity depending on water-filled pore space

    Directory of Open Access Journals (Sweden)

    H. Van Diest

    2008-04-01

    Full Text Available The exchange of carbonyl sulfide (COS between soil and the atmosphere was investigated for three arable soils from Germany, China and Finland and one forest soil from Siberia for parameterization in the relation to ambient carbonyl sulfide (COS concentration, soil water content (WC and air temperature. All investigated soils acted as sinks for COS. A clear and distinct uptake optimum was found for the German, Chinese, Finnish and Siberian soils at 11.5%, 9%, 11.5%, and 9% soil WC, respectively, indicating that the soil WC acts as an important biological and physical parameter for characterizing the exchange of COS between soils and the atmosphere. Different optima of deposition velocities (Vd as observed for the Chinese, Finnish and Siberian boreal soil types in relation to their soil WC, aligned at 19% in relation to the water-filled pore space (WFPS, indicating the dominating role of gas diffusion. This interpretation was supported by the linear correlation between Vd and bulk density. We suggest that the uptake of COS depends on the diffusivity dominated by WFPS, a parameter depending on soil WC, soil structure and porosity of the soil.

  9. New molecular technologies against infectious diseases during space flight

    Science.gov (United States)

    Cohen, Luchino Y.; Vernon, Marcia; Bergeron, Michel G.

    Latent virus reactivation, reduction in the number of immune cells, decreased cell activation and increased sensitivity of astronauts to infections following their return on Earth demonstrate that the immune system is less efficient during space flight. This dysfunction during long-term missions could result in the appearance of opportunistic infections or a decrease in the immuno-surveillance mechanisms that eradicate cancer cells. On the other hand, monitoring of the microbial environment is essential to prevent infectious diseases in space. Therefore, both aspects will have to be monitored continuously during long-term missions in space, using miniature and semi-automated diagnostic systems. In the short term, such equipment will allow the study of the causes of space-related immunodeficiency, developing countermeasures to maintain an optimal immune function and improving our capacity to prevent infectious diseases during space missions. In order to achieve these objectives, a new diagnostic system has been designed to perform a set of biological and immunological assays on board spacecrafts. Through flow cytometric assays and molecular biology analyses, this diagnostic system will improve medical surveillance of astronauts and will be used to test countermeasures aimed at preventing immune deficiency during space missions.

  10. Micro-computed tomography analysis of post space preparation in root canals filled with carrier-based thermoplasticized gutta-percha.

    Science.gov (United States)

    Schroeder, A A; Ford, N L; Coil, J M

    2017-03-01

    To determine whether post space preparation deviated from the root canal preparation in canals filled with Thermafil, GuttaCore or warm vertically compacted gutta-percha. Forty-two extracted human permanent maxillary lateral incisors were decoronated, and their root canals instrumented using a standardized protocol. Samples were divided into three groups and filled with Thermafil (Dentsply Tulsa Dental Specialties, Johnson City, TN, USA), GuttaCore (Dentsply Tulsa Dental Specialties) or warm vertically compacted gutta-percha, before post space preparation was performed with a GT Post drill (Dentsply Tulsa Dental Specialties). Teeth were scanned using micro-computed tomography after root filling and again after post space preparation. Scans were examined for number of samples with post space deviation, linear deviation of post space preparation and minimum root thickness before and after post space preparation. Parametric data were analysed with one-way analysis of variance (anova) or one-tailed paired Student's t-tests, whilst nonparametric data were analysed with Fisher's exact test. Deviation occurred in eight of forty-two teeth (19%), seven of fourteen from the Thermafil group (50%), one of fourteen from the GuttaCore group (7%), and none from the gutta-percha group. Deviation occurred significantly more often in the Thermafil group than in each of the other two groups (P space preparation was greater in the Thermafil group than in both of the other groups and was significantly greater than that of the gutta-percha group (P space preparation was significantly greater than it was after post space preparation for all groups (P space deviation and in linear deviation of post space preparation were associated with the presence or absence of a carrier as well as the different carrier materials. © 2016 International Endodontic Journal. Published by John Wiley & Sons Ltd.

  11. Crack sealer fill characteristics.

    Science.gov (United States)

    2010-06-01

    Laboratory testing was conducted to determine the extent of crack fill for crack sealers composed of methyl methacrylate, : epoxy, urethane, and high molecular weight methacrylate. The test specimens consisted of eight-inch long concrete : cylinders ...

  12. Molecular analysis of rice plant mutated after space flight

    Science.gov (United States)

    Cheng, Z.; Li, C.; Wei, L.; Xu, D.; Gu, D.; Guan, S.; Zhao, H.; Xin, P.; Sun, Y.

    We have obtained several rice mutants planted from seeds flown on recoverable satellites. Some new traits, such as good yields, diseases resistances and higher nutrient values, have been identified, putatively as consequences of the space environment. Radiation inside the Chinese recoverable satellite was composed of low flux of high energy particles (>40 Mev/u). To study the mechanisms of plant mutations induced by the space environment, we used dry rice seeds as a model to identify the phenotype of mutations, and used the wealth of the rice genome to identify the mutated genes in the mutants. The research included collecting rice plant mutants in the seeds flown on the satellites, identifying the nature of genomic and proteomic alterations, modifications and identifying the functional changes of the specific genes. The study showed that the rice seeds are a good model for exploring biological effect of space environment since 1) it is easy fly the seeds without specific hardware and crew work, 2) it is easy to obtain pure mutant breed lines for cloning DNA sequence in order to compare with the sequence in the wild type, and 3) it is easy to quantitatively analyze genetics using advanced molecular techniques.

  13. PSExplorer: whole parameter space exploration for molecular signaling pathway dynamics.

    Science.gov (United States)

    Tung, Thai Quang; Lee, Doheon

    2010-10-01

    Mathematical models of biological systems often have a large number of parameters whose combinational variations can yield distinct qualitative behaviors. Since it is intractable to examine all possible combinations of parameters for non-trivial biological pathways, it is required to have a systematic strategy to explore the parameter space in a computational way so that dynamic behaviors of a given pathway are estimated. We present PSExplorer, a computational tool for exploring qualitative behaviors and key parameters of molecular signaling pathways. Utilizing the Latin hypercube sampling and a clustering technique in a recursive paradigm, the software enables users to explore the whole parameter space of the models to search for robust qualitative behaviors. The parameter space is partitioned into sub-regions according to behavioral differences. Sub-regions showing robust behaviors can be identified for further analyses. The partitioning result presents a tree structure from which individual and combinational effects of parameters on model behaviors can be assessed and key factors of the models are readily identified. The software, tutorial manual and test models are available for download at the following address: http://gto.kaist.ac.kr/∼psexplorer.

  14. Design Of And Image Editing With A Space-Filling Three-Dimensional Display Based On A Standard Raster Graphics System

    Science.gov (United States)

    Fuchs, Henry; Pizer, Stephen M.; Heinz, E. Ralph; Bloomberg, Sandra H.; Tsai, Li-Ching; Strickland, Dorothy C.

    1983-04-01

    We are developing graphics systems, image preprocessing methods, and interactive manipulation techniques for a space-filling 3D display using a varifocal mirror principle. Our driving problem is a medical imaging need for presentation of three-dimensional intensity information. The major goal of both the image preprocessing and the interactive manipulation has been to overcome obscuration, which we feel is coming to be recognized as the central problem in any space-filling display. In our system, the preprocessing step highlights important image features such as surfaces. At display time, the object can be dynamically edited and rotated for convenient viewing from various directions. Our particular hardware design allows the 3D display to be constructed as an inexpensive add-on to a standard video graphics system. The interactive rotation and other manipulations are achieved by the standard built-in graphics processor.

  15. Data-partitioning using the Hilbert space filling curves: effect on the speed of convergence of Fuzzy ARTMAP for large database problems.

    Science.gov (United States)

    Castro, José; Georgiopoulos, Michael; Demara, Ronald; Gonzalez, Avelino

    2005-09-01

    The Fuzzy ARTMAP algorithm has been proven to be one of the premier neural network architectures for classification problems. One of the properties of Fuzzy ARTMAP, which can be both an asset and a liability, is its capacity to produce new nodes (templates) on demand to represent classification categories. This property allows Fuzzy ARTMAP to automatically adapt to the database without having to a priori specify its network size. On the other hand, it has the undesirable side effect that large databases might produce a large network size (node proliferation) that can dramatically slow down the training speed of the algorithm. To address the slow convergence speed of Fuzzy ARTMAP for large database problems, we propose the use of space-filling curves, specifically the Hilbert space-filling curves (HSFC). Hilbert space-filling curves allow us to divide the problem into smaller sub-problems, each focusing on a smaller than the original dataset. For learning each partition of data, a different Fuzzy ARTMAP network is used. Through this divide-and-conquer approach we are avoiding the node proliferation problem, and consequently we speedup Fuzzy ARTMAP's training. Results have been produced for a two-class, 16-dimensional Gaussian data, and on the Forest database, available at the UCI repository. Our results indicate that the Hilbert space-filling curve approach reduces the time that it takes to train Fuzzy ARTMAP without affecting the generalization performance attained by Fuzzy ARTMAP trained on the original large dataset. Given that the resulting smaller datasets that the HSFC approach produces can independently be learned by different Fuzzy ARTMAP networks, we have also implemented and tested a parallel implementation of this approach on a Beowulf cluster of workstations that further speeds up Fuzzy ARTMAP's convergence to a solution for large database problems.

  16. Trans-cis molecular photoswitching in interstellar Space.

    Science.gov (United States)

    Cuadrado, S; Goicoechea, J R; Roncero, O; Aguado, A; Tercero, B; Cernicharo, J

    2016-12-01

    As many organic molecules, formic acid (HCOOH) has two conformers (trans and cis). The energy barrier to internal conversion from trans to cis is much higher than the thermal energy available in molecular clouds. Thus, only the most stable conformer (trans) is expected to exist in detectable amounts. We report the first interstellar detection of cis-HCOOH. Its presence in ultraviolet (UV) irradiated gas exclusively (the Orion Bar photodissociation region), with a low trans-to-cis abundance ratio of 2.8 ± 1.0, supports a photoswitching mechanism: a given conformer absorbs a stellar photon that radiatively excites the molecule to electronic states above the interconversion barrier. Subsequent fluorescent decay leaves the molecule in a different conformer form. This mechanism, which we specifically study with ab initio quantum calculations, was not considered in Space before but likely induces structural changes of a variety of interstellar molecules submitted to UV radiation.

  17. Trans-cis molecular photoswitching in interstellar Space*

    Science.gov (United States)

    Cuadrado, S.; Goicoechea, J. R.; Roncero, O.; Aguado, A.; Tercero, B.; Cernicharo, J.

    2016-01-01

    As many organic molecules, formic acid (HCOOH) has two conformers (trans and cis). The energy barrier to internal conversion from trans to cis is much higher than the thermal energy available in molecular clouds. Thus, only the most stable conformer (trans) is expected to exist in detectable amounts. We report the first interstellar detection of cis-HCOOH. Its presence in ultraviolet (UV) irradiated gas exclusively (the Orion Bar photodissociation region), with a low trans-to-cis abundance ratio of 2.8 ± 1.0, supports a photoswitching mechanism: a given conformer absorbs a stellar photon that radiatively excites the molecule to electronic states above the interconversion barrier. Subsequent fluorescent decay leaves the molecule in a different conformer form. This mechanism, which we specifically study with ab initio quantum calculations, was not considered in Space before but likely induces structural changes of a variety of interstellar molecules submitted to UV radiation. PMID:28003686

  18. A Molecular Genetic Basis Explaining Altered Bacterial Behavior in Space.

    Directory of Open Access Journals (Sweden)

    Luis Zea

    Full Text Available Bacteria behave differently in space, as indicated by reports of reduced lag phase, higher final cell counts, enhanced biofilm formation, increased virulence, and reduced susceptibility to antibiotics. These phenomena are theorized, at least in part, to result from reduced mass transport in the local extracellular environment, where movement of molecules consumed and excreted by the cell is limited to diffusion in the absence of gravity-dependent convection. However, to date neither empirical nor computational approaches have been able to provide sufficient evidence to confirm this explanation. Molecular genetic analysis findings, conducted as part of a recent spaceflight investigation, support the proposed model. This investigation indicated an overexpression of genes associated with starvation, the search for alternative energy sources, increased metabolism, enhanced acetate production, and other systematic responses to acidity-all of which can be associated with reduced extracellular mass transport.

  19. [Partial k-space sampling with zero filling used with phase-contrast flow measurements: in vivo and in vitro validation].

    Science.gov (United States)

    Pertschy, S; Meyer, G P; Waalkes, S; Doeker, R; Koshedub, R; Noeske, R; Galanski, M; Lotz, J

    2006-07-01

    To validate the technique of partial k-space sampling and zero filling with phase-contrast flow measurements as compared to measurements with full k-space sampling. In vitro: A laminar flow phantom was utilized to evaluate the effect of partial k-space sampling on the accuracy, precision and signal-to-noise ratio of phase-contrast flow measurements. In vivo: The effect of partial k-space sampling on the quantification of cardiac output (n = 40 patients) and the duration of the scan were evaluated in the ascending aorta (n = 37) and pulmonary trunk (n = 34) in a prospective study. Partial k-space sampling resulted in an increase in the SNR by 2 % in vitro. The precision was altered by less than 1 %. Flow volumes were systematically overestimated by 3.5 %. No significant differences were found in the in vivo measurements of cardiac output. The scan duration was reduced by 34 % by utilizing partial k-space sampling. Partial k-space sampling can be used to reduce scan time without a significant decrease in the accuracy or precision of phase-contrast flow measurements in large arteries.

  20. Filling-in of Near-infrared Solar Lines by Terrestrial Fluorescence and Other Geophysical Effects: Simulations and Space-based Observations from SCIAMACHY and GOSAT

    Science.gov (United States)

    Joiner, Joanna (Editor); Yoshida, Yasuko; Vasilkov, A. P.; Middleton, E. M. (Editor); Campbell, P. K. E.; Yoshida, Y.; Huze, A.; Corp, L. A.

    2012-01-01

    Global mapping of terrestrial vegetation fluorescence from space has recently been accomplished with high spectral resolution (nu/nu greater than 35 000) measurements from the Japanese Greenhouse gases Observing SAellite (GOSAT). These data are of interest because they can potentially provide global information on the functional status of vegetation including light-use efficiency and global primary productivity that can be used for global carbon cycle modeling. Quantifying the impact of fluorescence on the O2-A band is important as this band is used for photon pathlength characterization in cloud- and aerosol-contaminated pixels for trace-gas retrievals including CO2. Here, we examine whether fluorescence information can be derived from space using potentially lower-cost hyperspectral instrumentation, i.e., more than an order of magnitude less spectral resolution (nu/nu approximately 1600) than GOSAT, with a relatively simple algorithm. We discuss laboratory measurements of fluorescence near one of the few wide and deep solar Fraunhofer lines in the long-wave tail of the fluorescence emission region, the calcium (Ca) II line at 866 nm that is observable with a spectral resolution of approximately 0.5 nm. The filling-in of the Ca II line due to additive signals from various atmospheric and terrestrial effects, including fluorescence, is simulated. We then examine filling-in of this line using the SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY (SCIAMACHY) satellite instrument. In order to interpret the satellite measurements, we developed a general approach to correct for various instrumental artifacts that produce false filling-in of solar lines in satellite measurements. The approach is applied to SCIAMACHY at the 866 nm Ca II line and to GOSAT at 758 and 770 nm on the shoulders of the O2-A feature where there are several strong solar Fraunhofer lines that are filled in primarily by vegetation fluorescence. Finally, we compare temporal and

  1. Filling a Conical Cavity

    Science.gov (United States)

    Nye, Kyle; Eslam-Panah, Azar

    2016-11-01

    Root canal treatment involves the removal of infected tissue inside the tooth's canal system and filling the space with a dense sealing agent to prevent further infection. A good root canal treatment happens when the canals are filled homogeneously and tightly down to the root apex. Such a tooth is able to provide valuable service for an entire lifetime. However, there are some examples of poorly performed root canals where the anterior and posterior routes are not filled completely. Small packets of air can be trapped in narrow access cavities when restoring with resin composites. Such teeth can cause trouble even after many years and lead the conditions like acute bone infection or abscesses. In this study, the filling of dead-end conical cavities with various liquids is reported. The first case studies included conical cavity models with different angles and lengths to visualize the filling process. In this investigation, the rate and completeness at which a variety of liquids fill the cavity were observed to find ideal conditions for the process. Then, a 3D printed model of the scaled representation of a molar with prepared post spaces was used to simulate the root canal treatment. The results of this study can be used to gain a better understanding of the restoration for endodontically treated teeth.

  2. Space-time-wave number-frequency Z(x, t, k, f) analysis of SAW generation on fluid filled cylindrical shells.

    Science.gov (United States)

    Martinez, Loïc; Morvan, Bruno; Izbicki, Jean Louis

    2004-04-01

    A new 4D space-time-wave number-frequency representation Z(x,t,k,f) is introduced. The Z(x,t,k,f) representation is used for processing 2D space-time signal collection issued from wave propagation along a 1D medium. This representation is an extension along the time dimension of the space-wave number-frequency representation. The Z(x,t,k,f) representation is obtained by short time-space 2D Fourier transforming the space-time collection. The Z(x,t,k,f) representation allows the characterization transient aspects of wave generation and propagation in both space and time dimensions. The Z(x,t,k,f) representation is used to experimentally investigate Lamb wave generation and propagation around a cylindrical shell (relative thickness is equal to 0.03) surrounded by water and excited by a pulse (0.1 micros duration with 1-5 MHz transducers). Three kinds of fluids have been used inside the shell: air, water, propanol. In all the cases, the Z(x,t,k,f) analysis clearly identify the reflected field on the insonified side of the shell and it allows the measurement of the local reflection coefficients R(x,t,k,f). The generation and the propagation of Lamb waves are also quantified. For the liquid filled shells, the multiple internal reflections are revealed by Z(x,t,k,f) analysis: the local transmission coefficients T(x,t,k,f) are also measured. When local matching conditions allows Lamb wave generation, the multiple regeneration of Lamb wave is observed. Based on these results, a link is establish toward the theoretical results obtained by steady state approach and Sommerfeld-Watson transform.

  3. MICROBIAL LEAKAGE AND APICAL INFLAMMATORY RESPONSE IN DOG’S TEETH AFTER ROOT CANAL FILLING WITH DIFFERENT SEALERS, POST SPACE PREPARATION AND EXPOSURE TO THE ORAL ENVIRONMENT

    Science.gov (United States)

    Gomes, Maximiliano Schünke; Barletta, Fernando Branco; Bona, Alvaro Della; Vanni, José Roberto; Pereira, Charles da Cunha; de Figueiredo, José Antônio Poli

    2007-01-01

    Coronal leakage is an important factor affecting the outcome of endodontic therapy. This study evaluated the microbial leakage (ML) and the apical inflammatory response (AIR) in dog’s teeth after root canal filling with three endodontic sealers, post preparation and exposure to the oral environment, testing the hypothesis that there is a positive correlation between these two histological parameters (ML and AIR). Sixty-four root canals of 8 mongrel dogs were cleaned, shaped and randomly distributed into groups according to the sealer to be used: Sealer 26 (n=18); AH Plus (n=18); RoekoSeal (n=19); no sealer – control group (n=9). Root canals were filled by the lateral condensation technique. Post space preparation left 4 mm of filling material in the apical root third, and specimens were exposed to the oral environment for 90 days. The dogs were killed and jaw blocks were histologically processed using Brown & Brenn and HE staining techniques. ML and AIR were scored from 1 to 4. Results were analyzed statistically using ANOVA, Duncan’s post-hoc test and Spearman’s correlation. ML and AIR score means were: Sealer 26 - 2.44±0.98 and 2.50±0.70; AH Plus - 2.50±0.78 and 2.22±0.54; RoekoSeal - 1.84±0.95 and 2.63±0.83; Control - 2.56±1.23 and 3.11±0.60. Statistically significant differences in AIR scores were found between the AH Plus and control groups (p<0.05). Although RoekoSeal had the lowest ML means, and AH Plus, the lowest AIR means after 90-day exposure to the oral environment, no statistically significant differences were found between the three sealers under study, and no correlation was found between ML and AIR. PMID:19089174

  4. Espacios aéreos pulmonares anormales por TCAR Abnormal air-filled spaces in the lung with HRCT

    Directory of Open Access Journals (Sweden)

    Juan Carlos Spina (h

    2008-06-01

    Full Text Available Objetivo: El propósito de este trabajo es revisar y dar claves para el diagnóstico de las distintas entidades que se presentan como espacios aéreos pulmonares anormales. Material y métodos: Se analizaron en forma retrospectiva los archivos de TCAR de nuestra institución con diagnóstico de espacios aéreos pulmonares anormales. En todos los casos se evaluó la localización, número (único o múltiples, grosor parietal y alteraciones parenquimatosas y mediastínicas asociadas y se los agrupo de acuerdo con su asociación con distintas enfermedades. Resultados: En base a las características topográficas, los espacios aéreos anormales fueron agrupados en: etiología infecciosa (tuberculosis, neumonía por Pneumocistis jiroveci, aspergilosis, hidatidosis, neumonía cavitada, absceso y neumatocele, enfermedades que producen bronquiectasias (fibrosis quística, síndrome de Kartagener, aspergilosis broncopulmonar alérgica, vasculitis ( granulomatosis de wegener y artritis reumatoidea, enfisema, neoplasias no primitivas (metástasis cavitadas, tumores primarios (carcinoma epidermoide y bronquioloalveolar y otras (linfangioleiomiomatosis, histiocitosis de células de Langerhans, secuestro pulmonar y malformación adenoidea quística. Conclusión: Los espacios aéreos pulmonares anormales son un hallazgo frecuente en los estudios por TCAR. Teniendo en cuenta cierta característica de los mismos, es posible arribar a un diagnóstico probable en la mayoría de los casos.Objetive: The purpose of this paper is to review and give some clues for the diagnosis of the many entities that present as abnormal air spaces at HRCT. Materials and methods: We retrospectively reviewed the archives of HRCT of our institution with diagnosis of different entities that presented with abnormal air spaces. In all cases we evaluated the location, number (unique o multiple, parietal thickness and concomitant compromise of parenchyma or mediastinum and we clustered

  5. Efficiency of Molecular Machines with Continuous Phase Space

    DEFF Research Database (Denmark)

    Golubeva, Natalia

    We consider a molecular machine described as a Brownian particle diffusing in a tilted periodic potential. We evaluate the absorbed and released power of the machine as a function of the applied molecular and chemical forces, by using the fact that the times for completing a cycle in the forward...... for a broad class of 2-D models of a Brownian machine and find that loosely coupled machines operate with a smaller efficiency at maximum power than their strongly coupled counterparts....

  6. Efficiency of Molecular Machines with Continuous Phase Space

    DEFF Research Database (Denmark)

    Golubeva, Natalia; Imparato, Alberto; Peliti, Luca

    2012-01-01

    We consider a molecular machine described as a Brownian particle diffusing in a tilted periodic potential. We evaluate the absorbed and released power of the machine as a function of the applied molecular and chemical forces, by using the fact that the times for completing a cycle in the forward...... for a broad class of 2-D models of a Brownian machine and find that loosely coupled machines operate with a smaller efficiency at maximum power than their strongly coupled counterparts....

  7. Universal Sample Preparation Module for Molecular Analysis in Space Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Lynntech proposes to develop and demonstrate the ability of a compact, light-weight, and automated universal sample preparation module (USPM) to process samples from...

  8. Molecular dynamics simulations on desulfurization of n-octane/thiophene mixture using silica filled polydimethylsiloxane nanocomposite membranes

    Science.gov (United States)

    Shariatinia, Zahra; Mazloom Jalali, Azin; Afshar Taromi, Faramarz

    2016-03-01

    Molecular dynamics (MD) simulations were performed at 298.15 K and 1 atm in order to study microstructure and transport behaviors of polydimethylsiloxane (PDMS) membranes containing 0%-8% SiO2 nanoparticles used for the separation of thiophene from n-octane. It was found that the fractional free volume (FFV) of 0% SiO2 was the highest (47.24%) among five nanocomposite membranes and addition of 2%-8% silica nanoparticles led to dramatic decrease in the FFV of the cells. The x-ray diffraction (XRD) patterns of all membranes showed that they had a semi-crystalline structure containing a broad peak around 15°-18°. The radial distribution function (RDF) analysis proved that the smallest C(CH2-octane)-O(SiO2), C(PDMS)-O(SiO2) and H(thiophene)-O(SiO2) distances were present in 4% SiO2 membrane reflecting the silica-octane, silica-polymer and silica-thiophene interactions were the strongest in this membrane. The mean squared displacement (MSD) and diffusion coefficients of n-octane were both small in the 6% silica membrane but they were high for thiophene suggesting this membrane was the most suitable for the desulfurization process and separation of thiophene from n-octane.

  9. Effect of timing and method of post space preparation on sealing ability of remaining root filling material: in vitro microbiological study.

    Science.gov (United States)

    Grecca, Fabiana Soares; Rosa, Angela Rezende Gomes; Gomes, Maximiliano Schünke; Parolo, Clarissa Fatturi; Bemfica, Jules Renan Dutra; Frasca, Luis Carlos da Fontoura; Maltz, Marisa

    2009-10-01

    To evaluate the effect of timing (immediate versus delayed) and technique of post space preparation on the ability of the residual root canal obturation to prevent coronal bacterial leakage. Sixty-six single-rooted teeth were decoronated at the cementoenamel junction. The canals were prepared according to a step-back technique and were filled with thermoplasticized gutta-percha and AH Plus endodontic sealer (Dentsply De Trey). The root segments were randomly assigned to 8 groups. The positive controls (n = 3) were instrumented but not obturated. The negative controls (n = 3) were instrumented, obturated and sealed with Cavit (3M ESPE). In the other 6 groups (n = 10 each), the post space was prepared either immediately after obturation or 7 days later using LA Axxess burs (SybronEndo) (groups 1 and 2), heated pluggers (groups 3 and 4) or solvent delivered with a hand file (groups 5 and 6). The external surface of all roots was rendered waterproof with nail varnish. Custom-made dual-chamber devices were used to evaluate leakage. The coronal third of the prepared root canal was kept in contact with artificial saliva contaminated with Enterococcus faecalis, and the root apex was submerged in tryptic soy agar medium. The root assemblies were stored at 37 degrees C and were monitored daily over a 90-day period. The occurrence of turbidity in the medium was deemed to indicate bacterial leakage, from which failure of the seal was inferred. Throughout the experimental period, there was no significant difference (p = 0.094) among the preparation techniques, either immediate or delayed, in terms of bacterial leakage. Immediate and delayed post space preparation yielded similar outcomes in terms of the canal seal. Regardless of the timing and the technique of post space preparation, coronal bacterial leakage occurred over time.

  10. Unit cell structure of water-filled monoolein into inverted hexagonal (H(II)) mesophase modeled by molecular dynamics.

    Science.gov (United States)

    Kolev, Vesselin L; Ivanova, Anela N; Madjarova, Galia K; Aserin, Abraham; Garti, Nissim

    2014-05-22

    The study investigates the unit cell structure of inverted hexagonal (H(II)) mesophase composed of monoolein (1-monoolein, GMO) and water using atomistic molecular dynamics methods without imposing any restraints on lipid and water molecules. Statistically meaningful and very contrast images of the radial mass density distribution, scrutinizing also the separate components water, monoolein, the polar headgroups of the lipids, the double bond, and the termini of the hydrocarbon chain (the tail), are obtained. The lipid/water interface structure is analyzed based on the obtained water density distribution, on the estimated number of hydrogen bonds per monoolein headgroup, and on the headgroup-water radial distribution functions. The headgroup mass density distribution demonstrates hexagonal shape of the monoolein/water interface that is well-defined at higher water/monoolein ratios. Water interacts with the headgroups by forming a three-layer diffusive mass density distribution, and each layer's shape is close to hexagonal, which is an indication of long-range structural interactions. It is found that the monoolein headgroups form a constant number of hydrogen bonds leaving an excessive amount of water molecules outside the first lipid coordination sphere. Furthermore, the quantity of water at the monoolein/water interface increases steadily upon extension of the unit cell, so the interface should have a very dynamic structure. Investigation of the hydrocarbon residues reveals high compression and well-expressed structuring of the tails. The tails form a very compressed and constrained structure of defined layers across the unit cell with properties corresponding to a more densely packed nonpolar liquid (oil). Due to the hexagonal shape the 2D packing frustration is constant and does not depend on the water content. All reported structural features are based on averaging of the atomic coordinates over the time-length of the simulation trajectories. That kind of

  11. Mechanics of filled carbon nanotubes

    KAUST Repository

    Monteiro, A.O.

    2014-04-01

    The benefits of filling carbon nanotubes (CNTs) with assorted molecular and crystalline substances have been investigated for the past two decades. Amongst the study of new structural phases, defects, chemical reactions and varied types of host-guest interactions, there is one fundamental characterisation aspect of these systems that continues to be overlooked: the mechanical behaviour of filled CNTs. In contrast to their empty counterparts, the mechanics of filled CNTs is a subject where reports appear far and apart, this despite being key to the application of these materials in technological devices. In the following paragraphs, we review the work that has been carried out up to the present on the mechanics of filled CNTs. The studies discussed range from experimental resonant frequency essays performed within electron microscopes to modelling, via molecular dynamics, of three-point bending of nanotubes filled with gases. (C) 2014 Elsevier B.V. All rights reserved.

  12. Extension of variational space in the antisymmetrized molecular dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Hirata, Yuichi; Ohnishi, Akira [Hokkaido Univ., Sapporo (Japan). Faculty of Science; Nara, Yasushi; Harada, Toru

    1997-05-01

    With starting from a framework of AMD (antisymmetrized molecular dynamics), {Xi}{sup -} reaction at rest was simulated by extended AMD which the width of Gauss wave packet of a particle wave function was applied to the time-dependence vibrational parameter. The results by AMD showed to produce many amount of complex nucleus with bounded two {Lambda}-particles, but that by extended AMD approached the experimental result which {Lambda}-particle was easily released from the complex nuclei. However, AMD and the extended AMD were able to describe only emission of {Lambda}-particle and not fragmentation of reaction ({Xi}{sup -}+{sup 12}C{yields}{sub {Lambda}}{sup 4}H+{sub {Lambda}}{sup 9}Be). (S.Y.)

  13. Machine learning of molecular electronic properties in chemical compound space

    Science.gov (United States)

    Montavon, Grégoire; Rupp, Matthias; Gobre, Vivekanand; Vazquez-Mayagoitia, Alvaro; Hansen, Katja; Tkatchenko, Alexandre; Müller, Klaus-Robert; Anatole von Lilienfeld, O.

    2013-09-01

    The combination of modern scientific computing with electronic structure theory can lead to an unprecedented amount of data amenable to intelligent data analysis for the identification of meaningful, novel and predictive structure-property relationships. Such relationships enable high-throughput screening for relevant properties in an exponentially growing pool of virtual compounds that are synthetically accessible. Here, we present a machine learning model, trained on a database of ab initio calculation results for thousands of organic molecules, that simultaneously predicts multiple electronic ground- and excited-state properties. The properties include atomization energy, polarizability, frontier orbital eigenvalues, ionization potential, electron affinity and excitation energies. The machine learning model is based on a deep multi-task artificial neural network, exploiting the underlying correlations between various molecular properties. The input is identical to ab initio methods, i.e. nuclear charges and Cartesian coordinates of all atoms. For small organic molecules, the accuracy of such a ‘quantum machine’ is similar, and sometimes superior, to modern quantum-chemical methods—at negligible computational cost.

  14. Origins Space Telescope: Tracing Dark Molecular Gas in the Milky Way

    Science.gov (United States)

    Narayanan, Desika; Li, Qi; Krumholz, Mark; Dave, Romeel; Origins Space Telescope Science and Technology Definition Team

    2018-01-01

    We present theoretical models for quantifying the fraction of CO-dark molecular gas in galaxies. To do this, we combine novel thermal, chemical, and radiative equilibrium calculations with high-resolution cosmological zoom galaxy formation models. We discuss how this dark molecular gas will be uncovered by the Origins Space Telescope, one of the four science and technology definition studies of NASA Headquarters for the 2020 Astronomy and Astrophysics Decadal survey.

  15. Understanding the hydrologic control of N cycle: Effect of water filled pore space on heterotrophic nitrification, denitrification and dissimilatory nitrate reduction to ammonium mechanisms in unsaturated soils.

    Science.gov (United States)

    Mekala, C; Nambi, Indumathi M

    2017-07-01

    Irrigation practice will be effective if it supplies optimal water and nutrients to crops and act as a filter for contaminants leaching to ground water. There is always a scope for improving the fertilizer use efficiency and scheduling of wastewater irrigation if the fate and transport of nutrients particularly nitrogenous compounds in the soil are well understood. In the present study, nitrogen transport experiments for two different agricultural soils are performed under varying saturation 33, 57, 78% water filled pore space for sandy soil 1 and 52, 81 and 96% for loam soil 2. A HYDRUS 2D model with constructed wetland (CW2D) module could simulate aerobic nitrification and anoxic denitrification well for both soils and estimated the reaction kinetics. A hot spot of Dissimilatory Nitrate Reduction to Ammonium (DNRA) pathway has been observed at 81% moisture content for a loamy sand soil. The presence of high organic content and reductive soil environment (5.53 C/NO 3 - ratio; ORP=-125mV) results in ammonium accumulation of 16.85mg in the soil. The overall observation from this study is nitrification occurs in a wide range of saturations 33-78% with highest at 57% whereas denitrification is significant at higher water saturations 57-78% for sandy soil texture. For a loamy sand soil, denitrification is dominant at 96% saturation with least nitrification at all saturation studies. The greatest nitrogen losses (>90%) was observed for soil 2 while 30-70% for soil1. The slow dispersive subsurface transport with varying oxygen dynamics enhanced nitrogen losses from soil2 due to lesser soil permeability. This in turn, prevents NO 3 - leaching and groundwater contamination. This type of modeling study should be used before planning field experiments for designing optimal irrigation and fertigation schedules. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Understanding the hydrologic control of N cycle: Effect of water filled pore space on heterotrophic nitrification, denitrification and dissimilatory nitrate reduction to ammonium mechanisms in unsaturated soils

    Science.gov (United States)

    Mekala, C.; Nambi, Indumathi M.

    2017-07-01

    Irrigation practice will be effective if it supplies optimal water and nutrients to crops and act as a filter for contaminants leaching to ground water. There is always a scope for improving the fertilizer use efficiency and scheduling of wastewater irrigation if the fate and transport of nutrients particularly nitrogenous compounds in the soil are well understood. In the present study, nitrogen transport experiments for two different agricultural soils are performed under varying saturation 33, 57, 78% water filled pore space for sandy soil 1 and 52, 81 and 96% for loam soil 2. A HYDRUS 2D model with constructed wetland (CW2D) module could simulate aerobic nitrification and anoxic denitrification well for both soils and estimated the reaction kinetics. A hot spot of Dissimilatory Nitrate Reduction to Ammonium (DNRA) pathway has been observed at 81% moisture content for a loamy sand soil. The presence of high organic content and reductive soil environment (5.53 C/NO3- ratio; ORP = - 125 mV) results in ammonium accumulation of 16.85 mg in the soil. The overall observation from this study is nitrification occurs in a wide range of saturations 33-78% with highest at 57% whereas denitrification is significant at higher water saturations 57-78% for sandy soil texture. For a loamy sand soil, denitrification is dominant at 96% saturation with least nitrification at all saturation studies. The greatest nitrogen losses (> 90%) was observed for soil 2 while 30-70% for soil1. The slow dispersive subsurface transport with varying oxygen dynamics enhanced nitrogen losses from soil2 due to lesser soil permeability. This in turn, prevents NO3- leaching and groundwater contamination. This type of modeling study should be used before planning field experiments for designing optimal irrigation and fertigation schedules.

  17. Molecular decompostition of anisotropic homogeneous mixed-norm spaces with applications to the boundedness of operators

    DEFF Research Database (Denmark)

    Cleanthous, Galatia; Georgiadis, Athanasios; Nielsen, Morten

    2018-01-01

    Anisotropic homogeneous mixed-norm Besov and Triebel–Lizorkin spaces are introduced and their properties are explored. A discrete adapted ϕ-transform decomposition is obtained. An associated class of almost diagonal operators is introduced and a boundedness result for such operators is obtained....... Molecular decompositions for all the considered spaces are derived with the help of the algebra of almost diagonal operators. As an application, we obtain boundedness results on the considered spaces for Fourier multipliers and for pseudodifferential operators with suitable adapted homogeneous symbols using...

  18. Application of Molecular Adsorber Coatings in Chamber A for the James Webb Space Telescope

    Science.gov (United States)

    Abraham, Nithin S.

    2017-01-01

    As a coating made of highly porous zeolite materials, the Molecular Adsorber Coating (MAC) was developed to capture outgassed molecular contaminants, such as hydrocarbons and silicones. For spaceflight applications, the adsorptive capabilities of the coating can alleviate on-orbit outgassing concerns on or near sensitive surfaces and instruments within the spacecraft. Similarly, this sprayable paint technology has proven to be significantly beneficial for ground-based space applications, in particular, for vacuum chamber environments. This presentation describes the application of the MAC technology for the James Webb Space Telescope (JWST) at NASA Johnson Space Center (JSC). The coating was used as a mitigation tool to entrap outgassed contaminants, specifically silicone-based diffusion pump oil, from within JSCs cryogenic optical vacuum chamber test facility called Chamber A. This presentation summarizes the background, fabrication, installation, chemical analysis test results, and future plans for the MAC technology, which was effectively used to protect the JWST test equipment from vacuum chamber contamination. As a coating made of highly porous zeolite materials, the Molecular Adsorber Coating (MAC) was developed to capture outgassed molecular contaminants, such as hydrocarbons and silicones. For spaceflight applications, the adsorptive capabilities of the coating can alleviate on-orbit outgassing concerns on or near sensitive surfaces and instruments within the spacecraft. Similarly, this sprayable paint technology has proven to be significantly beneficial for ground-based space applications, in particular, for vacuum chamber environments. This presentation describes the application of the MAC technology for the James Webb Space Telescope (JWST) at NASA Johnson Space Center (JSC). The coating was used as a mitigation tool to entrap outgassed contaminants, specifically silicone-based diffusion pump oil, from within JSCs cryogenic optical vacuum chamber test

  19. Molecular chaperones-related studies using latent stages of invertebrates exposed to space environment

    Science.gov (United States)

    Gusev, O. A.; Alexeev, V. R.; Sychev, V. N.; Okuda, T.; Saigusa, M.

    The latent stages of certain groups of invertebrates such as Artemia and Daphnia cyst Crustacea tuns of water bears Tardigrada are very perspective material for the investigation of the boundaries of the survival of the living organisms in the space environment While the number of authors showed that exposition the space flight causes the alteration in the survivability of the Artemia cysts there is no data about the changes in the stress response on the molecular level after short and long-termed space flight In this report we present preliminary results of the analysis of the expression of hsp90 chaperon in response to the heat shock in the larvae of the Artemia obtained from the cyst exposed to the real space flight onboard ISS for 1 and 6 month in the frame of the Aquarium program 2005-2006 and control ground group The perspectives of the usage of the molecular chaperons hsp in the studies for elucidation of the influence of the open space environment BIORISK and EXPOSE research programs on the immune response end general physiology of the invertebrates in their latent stages are discussed

  20. Dispersion relation for space-charge waves in a warm plasma-filled elliptical waveguide in an infinite axial magnetic field

    Science.gov (United States)

    Abdoli-Arani, A.; Safari, S.

    2015-04-01

    A perfectly conducting elliptical cylinder filled with a warm plasma and immersed in an infinite axial magnetic field is considered. Using Maxwell's equations and dielectric tensor, a Mathieu differential equation for axial component of electric field is obtained. Considering the boundary conditions, dispersion relation for waves in a plasma of warm electrons and immobile ions, which fills an elliptical waveguide and it is under the action of infinite axial magnetic field are calculated. Furthermore, dispersion relation and scalar potential in the quasi-static approximation in a cold magnetized plasma elliptical waveguide is calculated. The obtained results are graphically presented.

  1. Haldane phase in the Hubbard model at 2/3-filling for the organic molecular compound Mo3S7(dmit)3.

    Science.gov (United States)

    Janani, C; Merino, J; McCulloch, I P; Powell, B J

    2014-12-31

    We report the discovery of a correlated insulator with a bulk gap at 2/3 filling in a geometrically frustrated Hubbard model that describes the low-energy physics of Mo3S7(dmit)3. This is very different from the Mott insulator expected at half-filling. We show that the insulating phase, which persists even for very weak electron-electron interactions (U), is adiabatically connected to the Haldane phase and is consistent with experiments on Mo3S7(dmit)3.

  2. Using the Triple Labelling Technique to apportion N2O Emissions to Nitrification and Denitrification from different Nitrogen Sources at different Water-Filled-Pore-Spaces

    Science.gov (United States)

    Loick, Nadine; Dixon, Elizabeth R.; Repullo Ruibérriz de Torres, Miguel A.; Ciganda, Veronica; Lopez-Aizpun, Maria A.; Matthews, G. Peter; Müller, Christoph; Cardenas, Laura M.

    2017-04-01

    labelling technique - i.e. applying NH4NO3 with either the N at the NH4+ or at the NO3-, or in both places being labelled - this study investigates the effects of a low, medium and high water filled pore space (55, 70, 85%) in a clay soil on gaseous N emissions and investigates the source and processes leading to N2O emissions. To assess the utilisation of applied NO3- vs nitrified NO3- from applied NH4+, the model developed by Müller et al. (2007) is used to calculate the immobilisation of added NO3- and NH4+, nitrification of added NH4+, mineralisation of organic N and subsequent nitrification by the analysis of the 15N in the soil. Gross transformation rates, indicating the relative importance of added NO3- and NO3- derived from nitrified added NH4+ are calculated. Bergstermann et al. (2011) Soil Biol. & Biochem. 43, 240-250. Meijide et al. (2010) Eur. J. Soil Sci. 61, 364-374. Cárdenas et al. (2003) Soil Biol. & Biochem. 35, 867-870. Müller et al. (2007) Soil Biol. & Biochem. 39, 715-726.

  3. Machine Learning Predictions of Molecular Properties: Accurate Many-Body Potentials and Nonlocality in Chemical Space.

    Science.gov (United States)

    Hansen, Katja; Biegler, Franziska; Ramakrishnan, Raghunathan; Pronobis, Wiktor; von Lilienfeld, O Anatole; Müller, Klaus-Robert; Tkatchenko, Alexandre

    2015-06-18

    Simultaneously accurate and efficient prediction of molecular properties throughout chemical compound space is a critical ingredient toward rational compound design in chemical and pharmaceutical industries. Aiming toward this goal, we develop and apply a systematic hierarchy of efficient empirical methods to estimate atomization and total energies of molecules. These methods range from a simple sum over atoms, to addition of bond energies, to pairwise interatomic force fields, reaching to the more sophisticated machine learning approaches that are capable of describing collective interactions between many atoms or bonds. In the case of equilibrium molecular geometries, even simple pairwise force fields demonstrate prediction accuracy comparable to benchmark energies calculated using density functional theory with hybrid exchange-correlation functionals; however, accounting for the collective many-body interactions proves to be essential for approaching the “holy grail” of chemical accuracy of 1 kcal/mol for both equilibrium and out-of-equilibrium geometries. This remarkable accuracy is achieved by a vectorized representation of molecules (so-called Bag of Bonds model) that exhibits strong nonlocality in chemical space. In addition, the same representation allows us to predict accurate electronic properties of molecules, such as their polarizability and molecular frontier orbital energies.

  4. Molecular Models: Construction of Models with Magnets

    Directory of Open Access Journals (Sweden)

    Kalinovčić P.

    2015-07-01

    Full Text Available Molecular models are indispensable tools in teaching chemistry. Beside their high price, commercially available models are generally too small for classroom demonstration. This paper suggests how to make space-filling (callote models from Styrofoam with magnetic balls as connectors and disc magnets for showing molecular polarity

  5. Single-molecule femtochemistry: molecular imaging at the space-time limit.

    Science.gov (United States)

    Petek, Hrvoje

    2014-01-28

    Through a combination of light and electron probes, it may be possible to record single-molecule dynamics with simultaneous sub-Ångstrom spatial and femtosecond temporal resolution. Single-molecule femtochemistry is becoming a realistic prospect through a melding of laser spectroscopy and electron microscopy techniques. The paper by Lee et al. in this issue of ACS Nano takes a significant step toward chemical imaging at the space-time limit of chemical processes. By imaging electroluminescence spectra of single porphyrin molecules with submolecular resolution, the authors extract the implicit femtosecond dynamics of the coupled electron orbital-molecular skeletal motion triggered by a reduction-oxidation scattering process.

  6. Momentum-Space Imaging of the Dirac Band Structure in Molecular Graphene via Quasiparticle Interference

    Science.gov (United States)

    Stephenson, Anna; Gomes, Kenjiro K.; Ko, Wonhee; Mar, Warren; Manoharan, Hari C.

    2014-03-01

    Molecular graphene is a nanoscale artificial lattice composed of carbon monoxide molecules arranged one by one, realizing a dream of exploring exotic quantum materials by design. This assembly is done by atomic manipulation with a scanning tunneling microscope (STM) on a Cu(111) surface. To directly probe the transformation of normal surface state electrons into massless Dirac fermions, we map the momentum space dispersion through the Fourier analysis of quasiparticle scattering maps acquired at different energies with the STM. The Fourier analysis not only bridges the real-space and momentum-space data but also reveals the chiral nature of those quasiparticles, through a set of selection rules of allowed scattering involving the pseudospin and valley degrees of freedom. The graphene-like band structure can be reshaped with simple alterations to the lattice, such as the addition of a strain. We analyze the effect on the momentum space band structure of multiple types of strain on our system. Supported by DOE, Office of Basic Energy Sciences, Division of Materials Sciences and Engineering under contract DE-AC02-76SF00515.

  7. Defining desirable natural product derived anticancer drug space: optimization of molecular physicochemical properties and ADMET attributes

    Directory of Open Access Journals (Sweden)

    Deepika Singh

    2016-06-01

    Full Text Available As part of our endeavor to enhance survival of natural product derived drug candidates and to guide the medicinal chemist to design higher probability space for success in the anti cancer drug development area, we embarked on a detailed study of the property space for a collection of natural product derived anti cancer molecules. We carried out a comprehensive analysis of properties for 24 natural products derived anti cancer drugs including clinical development candidates and a set of 27 natural products derived anti cancer lead compounds. In particular, we focused on understanding the interplay among eight physicochemical properties including like partition coefficient (log P, distribution coefficient at pH=7.4 (log D, topological polar surface area (TPSA, molecular weight (MW, aqueous solubility (log S, number of hydrogen bond acceptors (HBA, number of hydrogen bond donors (HBD and number of rotatable bonds (nRot crucial for drug design and  relationships between physicochemical properties, ADME (absorption, distribution, metabolism, and elimination attributes, and in silico toxicity profile for these two sets of compounds. This analysis provides guidance for the chemist to modify the existing natural product scaffold or designing of new anti cancer molecules in a property space with increased probability of success and may lead to the identification of druglike candidates with favorable safety profiles that can successfully test hypotheses in the clinic.

  8. Communication: Hilbert-space partitioning of the molecular one-electron density matrix with orthogonal projectors.

    Science.gov (United States)

    Vanfleteren, Diederik; Van Neck, Dimitri; Bultinck, Patrick; Ayers, Paul W; Waroquier, Michel

    2010-12-21

    A double-atom partitioning of the molecular one-electron density matrix is used to describe atoms and bonds. All calculations are performed in Hilbert space. The concept of atomic weight functions (familiar from Hirshfeld analysis of the electron density) is extended to atomic weight matrices. These are constructed to be orthogonal projection operators on atomic subspaces, which has significant advantages in the interpretation of the bond contributions. In close analogy to the iterative Hirshfeld procedure, self-consistency is built in at the level of atomic charges and occupancies. The method is applied to a test set of about 67 molecules, representing various types of chemical binding. A close correlation is observed between the atomic charges and the Hirshfeld-I atomic charges.

  9. The protons of space and brain tumors II. Cellular and molecular considerations

    Science.gov (United States)

    Nagle, W. A.; Moss, A. J.; Dalrymple, G. V.; Cox, A. B.; Wigle, J. F.; Mitchell, J. C.

    1989-05-01

    An increased incidence of highly malignant gliomas, termed glioblastoma multiforme has been observed in Rhesus monkeys irradiated with 55 MeV protons, and in humans treated with therapeutic irradiation to the head. The results suggest a radiation etiology for these tumors. In this paper, we review briefly some characteristics of glioma tumors, and summarize the genetic changes associated with malignant gliomas in experimental animals and in humans. The genetic abnormalities include cytogenetic alterations, and changes in the structure and expression of specific oncogenes. We discuss the potential for these genetic changes to contribute to several putative mechanism leading to aberrant growth stimulation and, ultimately, to tumorigenesis. In addition, we review briefly some recent data concerning the molecular nature of radiation-induced somatic cell mutation and oncogene activation, and discuss the significance of these results for the radiation etiology of malignant gliomas. Finally, some implications of these results are discussed in relation to human radiation exposure in space.

  10. Molecular Energy Decompositions in the Hilbert-Space of Atomic Orbitals at Correlated Level

    Science.gov (United States)

    Alcoba, Diego R.; Bochicchio, Roberto C.; Lain, Luis; Torre, Alicia

    This work describes a new model to partition the molecular energy into one- and two-center contributions in the Hilbert-space of atomic orbitals at correlated level. Our proposal makes explicit use of the pairing nature of chemical bonding phenomena to accommodate appropriately the correlation effects within these contributions. The model is based on the treatment of the kinetic energy as contributing to both one- and two-atom terms, according to the pairing or unpairing character of the electron cloud, and on the appropriate assignment of the density cumulant dependent contributions. Numerical results for selected systems are reported and compared with those arising from other models, showing the reliability of our predictions.

  11. Transition voltages of vacuum-spaced and molecular junctions with Ag and Pt electrodes

    KAUST Repository

    Wu, Kunlin

    2014-07-07

    The transition voltage of vacuum-spaced and molecular junctions constructed with Ag and Pt electrodes is investigated by non-equilibrium Green\\'s function formalism combined with density functional theory. Our calculations show that, similarly to the case of Au-vacuum-Au previously studied, the transition voltages of Ag and Pt metal-vacuum-metal junctions with atomic protrusions on the electrode surface are determined by the local density of states of the p-type atomic orbitals of the protrusion. Since the energy position of the Pt 6p atomic orbitals is higher than that of the 5p/6p of Ag and Au, the transition voltage of Pt-vacuum-Pt junctions is larger than that of both Ag-vacuum-Ag and Au-vacuum-Au junctions. When one moves to analyzing asymmetric molecular junctions constructed with biphenyl thiol as central molecule, then the transition voltage is found to depend on the specific bonding site for the sulfur atom in the thiol group. In particular agreement with experiments, where the largest transition voltage is found for Ag and the smallest for Pt, is obtained when one assumes S binding at the hollow-bridge site on the Ag/Au(111) surface and at the adatom site on the Pt(111) one. This demonstrates the critical role played by the linker-electrode binding geometry in determining the transition voltage of devices made of conjugated thiol molecules. © 2014 AIP Publishing LLC.

  12. A New Take on John Maynard Smith's Concept of Protein Space for Understanding Molecular Evolution

    Science.gov (United States)

    Hartl, Daniel L.

    2016-01-01

    Much of the public lacks a proper understanding of Darwinian evolution, a problem that can be addressed with new learning and teaching approaches to be implemented both inside the classroom and in less formal settings. Few analogies have been as successful in communicating the basics of molecular evolution as John Maynard Smith’s protein space analogy (1970), in which he compared protein evolution to the transition between the terms WORD and GENE, changing one letter at a time to yield a different, meaningful word (in his example, the preferred path was WORD → WORE → GORE → GONE → GENE). Using freely available computer science tools (Google Books Ngram Viewer), we offer an update to Maynard Smith’s analogy and explain how it might be developed into an exploratory and pedagogical device for understanding the basics of molecular evolution and, more specifically, the adaptive landscape concept. We explain how the device works through several examples and provide resources that might facilitate its use in multiple settings, ranging from public engagement activities to formal instruction in evolution, population genetics, and computational biology. PMID:27736867

  13. A New Take on John Maynard Smith's Concept of Protein Space for Understanding Molecular Evolution.

    Science.gov (United States)

    Ogbunugafor, C Brandon; Hartl, Daniel L

    2016-10-01

    Much of the public lacks a proper understanding of Darwinian evolution, a problem that can be addressed with new learning and teaching approaches to be implemented both inside the classroom and in less formal settings. Few analogies have been as successful in communicating the basics of molecular evolution as John Maynard Smith's protein space analogy (1970), in which he compared protein evolution to the transition between the terms WORD and GENE, changing one letter at a time to yield a different, meaningful word (in his example, the preferred path was WORD → WORE → GORE → GONE → GENE). Using freely available computer science tools (Google Books Ngram Viewer), we offer an update to Maynard Smith's analogy and explain how it might be developed into an exploratory and pedagogical device for understanding the basics of molecular evolution and, more specifically, the adaptive landscape concept. We explain how the device works through several examples and provide resources that might facilitate its use in multiple settings, ranging from public engagement activities to formal instruction in evolution, population genetics, and computational biology.

  14. A New Take on John Maynard Smith's Concept of Protein Space for Understanding Molecular Evolution.

    Directory of Open Access Journals (Sweden)

    C Brandon Ogbunugafor

    2016-10-01

    Full Text Available Much of the public lacks a proper understanding of Darwinian evolution, a problem that can be addressed with new learning and teaching approaches to be implemented both inside the classroom and in less formal settings. Few analogies have been as successful in communicating the basics of molecular evolution as John Maynard Smith's protein space analogy (1970, in which he compared protein evolution to the transition between the terms WORD and GENE, changing one letter at a time to yield a different, meaningful word (in his example, the preferred path was WORD → WORE → GORE → GONE → GENE. Using freely available computer science tools (Google Books Ngram Viewer, we offer an update to Maynard Smith's analogy and explain how it might be developed into an exploratory and pedagogical device for understanding the basics of molecular evolution and, more specifically, the adaptive landscape concept. We explain how the device works through several examples and provide resources that might facilitate its use in multiple settings, ranging from public engagement activities to formal instruction in evolution, population genetics, and computational biology.

  15. Molecular and Cellular Characterization of Space Flight Effects on Microvascular Endothelial Cell Function - PreparatoryWork for the SFEF Project

    Science.gov (United States)

    Balsamo, Michele; Barravecchia, Ivana; Mariotti, Sara; Merenda, Alessandra; De Cesari, Chiara; Vukich, Marco; Angeloni, Debora

    2014-12-01

    Exposure to microgravity during space flight (SF) of variable length induces suffering of the endothelium (the cells lining all blood vessels), mostly responsible for health problems found in astronauts and animals returning from space. Of interest to pre-nosological medicine, the effects of microgravity on astronauts are strikingly similar to the consequences of sedentary life, senescence and degenerative diseases on Earth, although SF effects are accelerated and reversible. Thus, microgravity is a significant novel model for better understanding of common pathologies. A comprehensive cell and molecular biology study is needed in order to explain pathophysiological findings after SFs. This project will study the effects of microgravity and cosmic radiation on endothelial cells (ECs) cultured on the International Space Station through analysis of 1) cell transcriptome, 2) DNA methylome, 3) DNA damage and cell senescence, 4) variations in cell cycle and cell morphology. This project has been selected by the European Space Agency and the Italian Space Agency and is presently in preparation. The ground study presented here was performed to determine the biological and engineering requirements that will allow us to retrieve suitable samples after culturing, fixing and storing ECs in space. We expect to identify molecular pathways activated by space microgravity in microvascular ECs, which may shed light on pathogenic molecular mechanisms responsible for endothelial suffering shared by astronauts and individuals affected with aging, degenerative and sedentary life-associated pathologies on Earth.

  16. Real-space investigation of energy transfer in heterogeneous molecular dimers

    Science.gov (United States)

    Imada, Hiroshi; Miwa, Kuniyuki; Imai-Imada, Miyabi; Kawahara, Shota; Kimura, Kensuke; Kim, Yousoo

    2016-10-01

    Given its central role in photosynthesis and artificial energy-harvesting devices, energy transfer has been widely studied using optical spectroscopy to monitor excitation dynamics and probe the molecular-level control of energy transfer between coupled molecules. However, the spatial resolution of conventional optical spectroscopy is limited to a few hundred nanometres and thus cannot reveal the nanoscale spatial features associated with such processes. In contrast, scanning tunnelling luminescence spectroscopy has revealed the energy dynamics associated with phenomena ranging from single-molecule electroluminescence, absorption of localized plasmons and quantum interference effects to energy delocalization and intervalley electron scattering with submolecular spatial resolution in real space. Here we apply this technique to individual molecular dimers that comprise a magnesium phthalocyanine and a free-base phthalocyanine (MgPc and H2Pc) and find that locally exciting MgPc with the tunnelling current of the scanning tunnelling microscope generates a luminescence signal from a nearby H2Pc molecule as a result of resonance energy transfer from the former to the latter. A reciprocating resonance energy transfer is observed when exciting the second singlet state (S2) of H2Pc, which results in energy transfer to the first singlet state (S1) of MgPc and final funnelling to the S1 state of H2Pc. We also show that tautomerization of H2Pc changes the energy transfer characteristics within the dimer system, which essentially makes H2Pc a single-molecule energy transfer valve device that manifests itself by blinking resonance energy transfer behaviour.

  17. Cold Sugar in Space Provides Clue to the Molecular Origin of Life

    Science.gov (United States)

    2004-09-01

    Astronomers using the National Science Foundation's giant Robert C. Byrd Green Bank Telescope (GBT) have discovered a frigid reservoir of simple sugar molecules in a cloud of gas and dust some 26,000 light-years away, near the center of our Milky Way Galaxy. The discovery suggests how the molecular building blocks necessary for the creation of life could first form in interstellar space. Interstellar Chemistry Section of graphic illustrating processes that may produce complex molecules in cold interstellar space. CREDIT: Bill Saxton, NRAO/AUI/NSF (Click on Image for More Graphics) The astronomers detected the 8-atom sugar molecule glycolaldehyde in a gas-and-dust cloud called Sagittarius B2. Such clouds, often many light-years across, are the raw material from which new stars and planets are formed. The astronomers detected the same molecule in a warmer part of that cloud in 2000, but the new detection shows that the sugar exists at an extremely low temperature -- only 8 degrees above absolute zero, the temperature at which all molecular motion stops. The cold glycolaldehyde detections were surprisingly strong when compared to the original detections and indicate that a considerable quantity of this simple interstellar sugar exists at extremely low temperatures. Glycoaldehyde is composed of 2 carbon atoms, 2 oxygen atoms and 4 hydrogen atoms and is called a 2-carbon sugar. Glycolaldehyde can react with a 3-carbon sugar to produce a 5-carbon sugar called ribose. Ribose molecules form the backbone structure of the molecules DNA and RNA, which carry the genetic code of living organisms. On Earth, most chemical reactions occur in liquid water. Conditions are quite different in interstellar space, and most of the complex molecules appear to form on or under the surfaces of tiny dust grains. In this scenario, smaller molecules such as water, formaldehyde, methane, ammonia, carbon dioxide, or methanol, coat the surfaces and interiors of dust grains in the clouds. When a

  18. Low-Molecular-Weight Heparin-Coated and Montelukast-Filled Inhalable Particles: A Dual-Drug Delivery System for Combination Therapy in Asthma.

    Science.gov (United States)

    Patel, Brijeshkumar; Rashid, Jahidur; Gupta, Nilesh; Ahsan, Fakhrul

    2017-04-01

    Montelukast, a cysteinyl leukotriene type 1 receptor antagonist, exhibits secondary anti-inflammatory properties when used at higher concentrations. Low-molecular-weight heparin (LMWH) evokes pronounced anti-inflammatory effects by interrupting leukocyte adhesion and migration. We hypothesized that inhalable particles containing montelukast plus LMWH release both drugs in a sustained fashion and protect the lungs against allergen-induced inflammation. Large porous particles of montelukast and LMWH were prepared using a double-emulsion-solvent-evaporation method. Montelukast was first encapsulated in copolymer-based particles using polyethylenimine as a porosigen; the resulting particles were then coated with LMWH. The particles were evaluated for physicochemical properties, respirability, and release profiles. The anti-inflammatory effect of the optimized formulation was studied in ovalbumin-sensitized asthmatic Sprague Dawley rats. The optimized large porous particles had a diameter of 10.3 ± 0.7 μm, exhibited numerous surface indentations and pores, showed acceptable drug entrapment efficiency (66.8% ± 0.4% for montelukast; 91.7% ± 0.8% adsorption efficiency for LMWH), demonstrated biphasic release patterns, and escaped the uptake by the rat alveolar macrophages. The number of infiltrating inflammatory cells in asthmatic rat lungs, treated with dual-drug particles, was >74% fewer than in untreated asthmatic rat lungs. Similarly, the airway walls of asthmatic animals treated with dual-drug particles were 3-fold thinner than those of untreated asthmatic animals (p montelukast and LMWH, into an inhalable particulate system and establishes that this novel combination therapy produces sustained drug release and elicits a robust anti-inflammatory response in the lungs. Copyright © 2017 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

  19. Molecular Simulation Uncovers the Conformational Space of the λ Cro Dimer in Solution

    Science.gov (United States)

    Ahlstrom, Logan S.; Miyashita, Osamu

    2011-01-01

    The significant variation among solved structures of the λ Cro dimer suggests its flexibility. However, contacts in the crystal lattice could have stabilized a conformation which is unrepresentative of its dominant solution form. Here we report on the conformational space of the Cro dimer in solution using replica exchange molecular dynamics in explicit solvent. The simulated ensemble shows remarkable correlation with available x-ray structures. Network analysis and a free energy surface reveal the predominance of closed and semi-open dimers, with a modest barrier separating these two states. The fully open conformation lies higher in free energy, indicating that it requires stabilization by DNA or crystal contacts. Most NMR models are found to be unstable conformations in solution. Intersubunit salt bridging between Arg4 and Glu53 during simulation stabilizes closed conformations. Because a semi-open state is among the low-energy conformations sampled in simulation, we propose that Cro-DNA binding may not entail a large conformational change relative to the dominant dimer forms in solution. PMID:22098751

  20. Molecular Ions and Other Exotic Molecules in Space: A Coordinated Astronomical, Laboratory, and Theoretical Study

    Science.gov (United States)

    McCarthy, Michael

    This proposal request funds to continue a laboratory program in close coordination with radio astronomical observations dedicated to the study of highly reactive molecular ions, radicals, and metastable isomers that are thought to be key intermediates in rich interstellar and circumstellar sources. Determining the carriers of strong unidentified lines, such as U617.6 which has recently been observed with the Herschel space satellite, is the type of problem in laboratory astrophysics that our group is particularly adept at, and will be also emphasized in the upcoming grant period. Most new molecular species will be detected using microwave cavity rotational spectroscopy, followed either by microwave/millimeter-wave double resonance or millimeter/THz absorption to better characterize the rotational spectra in bands where Herschel and SOFIA operate. Using this combined approach, the rotational spectra of a number of ions of astronomical interest such as the cis- and trans isomers of HOSO+, H2NCO+, HNCOH+, H2CCHCNH+, C3N-, and NCO- have recently been detected in our laboratory, as have metastable isomers or derivatives of isocyanic acid, HNCO. As a result of this work, HOCN, HSCN, TiO2, and several molecular anions have been identified for the first time in space in the span of only a few years. Emphasis in the upcoming grant period will be placed on the detection of diatomic and small polyatomic ions such as SiH+, SiN-, CN+, NCS-, etc., other prototypical ions, including protonated benzene C6H7+, and silicon- and phosphorus-bearing species of astronomical interest. On the assumption that U617.6 is the fundamental b-type transition of a small polyatomic molecule, systematic searches for species of the form XOH, where X is likely either an atom or diatomic, will be given high priority because slightly bent species with this functional group (e.g., NNOH+, SiOH, etc.) possess an A rotational constants of about the right magnitude. Instrumental refinement will also be

  1. Tension-filled Governance?

    DEFF Research Database (Denmark)

    Celik, Tim Holst

    on the statesituated tension-filled functional relationship between legitimation and accumulation, the study both historically and theoretically reworks this approach and reapplies it for the post-1970s/1990s governance period. It asks whether and to what extent governance has served as a distinctive post- 1970s/1990s...... state-facilitated way of bridging/altering the tension-filled relationship between legitimation and fiscal accumulation in Western European liberal-capitalist democratic polities....

  2. Intermontane valley fills

    OpenAIRE

    Mey, Jürgen (Diplom-Geologe)

    2017-01-01

    Sedimentary valley fills are a widespread characteristic of mountain belts around the world. They transiently store material over time spans ranging from thousands to millions of years and therefore play an important role in modulating the sediment flux from the orogen to the foreland and to oceanic depocenters. In most cases, their formation can be attributed to specific fluvial conditions, which are closely related to climatic and tectonic processes. Hence, valley-fill deposits constitute v...

  3. Real-space observation of spin-split molecular orbitals of adsorbed single-molecule magnets

    National Research Council Canada - National Science Library

    Schwöbel, Jörg; Fu, Yingshuang; Brede, Jens; Dilullo, Andrew; Hoffmann, Germar; Klyatskaya, Svetlana; Ruben, Mario; Wiesendanger, Roland

    2012-01-01

    A key challenge in the field of molecular spintronics, and for the design of single-molecule magnet-based devices in particular, is the understanding and control of the molecular coupling at the electrode interfaces...

  4. Useful(filling) Durkheim

    DEFF Research Database (Denmark)

    Liebst, Lasse Suonperä

    2011-01-01

    Already in the paradigmatic formulation in The Social Logic of Space Bill Hillier and Julienne Hanson stated the theoretical affinity between Space Syntax and sociology. Taking Émile Durkheim’s classic concept of social mor-phology as their analytical starting point, they established an operational...... clarify the way space syntax is embedding urban social life in morpho-logical space. Thus, it is this dual problem caused by the silence of sociology that the current paper is a contribution to transcend. First, the paper revisits Durkheim's social morphology and discusses the Space Syntax’s distinct...

  5. Microstructure Filled Hohlraums

    Energy Technology Data Exchange (ETDEWEB)

    Moore, A. S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Thomas, C. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Reese, T. M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-02-24

    We propose replacing the gas fill in a hohlraum with a low average density, variable uniformity 3D printed structure. This creates a bimodal hohlraum which acts like a vacuum hohlraum initially during the picket, but could protect the capsule from glint or direct illumination, and then once expanded, homogenizes to behave like a variable z gas-fill during peak portion of the drive. This is motivated by a two main aims: 1) reduction of the Au bubble velocity to improve inner beam propagation, and 2) the introduction of a low density, high-Z, x-ray converter to improve x-ray production in the hohlraum and uniformity of the radiation field seen by the capsule.

  6. Integration and mining of malaria molecular, functional and pharmacological data: how far are we from a chemogenomic knowledge space?

    CERN Document Server

    Birkholtz, L -M; Wells, G; Grando, D; Joubert, F; Kasam, V; Zimmermann, M; Ortet, P; Jacq, N; Roy, S; Hoffmann-Apitius, M; Breton, V; Louw, A I; Maréchal, E

    2006-01-01

    The organization and mining of malaria genomic and post-genomic data is highly motivated by the necessity to predict and characterize new biological targets and new drugs. Biological targets are sought in a biological space designed from the genomic data from Plasmodium falciparum, but using also the millions of genomic data from other species. Drug candidates are sought in a chemical space containing the millions of small molecules stored in public and private chemolibraries. Data management should therefore be as reliable and versatile as possible. In this context, we examined five aspects of the organization and mining of malaria genomic and post-genomic data: 1) the comparison of protein sequences including compositionally atypical malaria sequences, 2) the high throughput reconstruction of molecular phylogenies, 3) the representation of biological processes particularly metabolic pathways, 4) the versatile methods to integrate genomic data, biological representations and functional profiling obtained fro...

  7. Fluid Dynamics of Bottle Filling

    Science.gov (United States)

    McGough, Patrick; Gao, Haijing; Appathurai, Santosh; Basaran, Osman

    2011-11-01

    Filling of bottles is a widely practiced operation in a large number of industries. Well known examples include filling of ``large'' bottles with shampoos and cleaners in the household products and beauty care industries and filling of ``small'' bottles in the pharmaceutical industry. Some bottle filling operations have recently drawn much attention from the fluid mechanics community because of the occurrence of a multitude of complex flow regimes, transitions, and instabilities such as mounding and coiling that occur as a bottle is filled with a fluid. In this talk, we present a primarily computational study of the fluid dynamical challenges that can arise during the rapid filling of bottles. Given the diversity of fluids used in filling applications, we consider four representative classes of fluids that exhibit Newtonian, shear-thinning, viscoelastic, and yield-stress rheologies. The equations governing the dynamics of bottle filling are solved either in their full 3D but axisymmetric form or using the slender-jet approximation.

  8. Hydrogen Filling Station

    Energy Technology Data Exchange (ETDEWEB)

    Boehm, Robert F; Sabacky, Bruce; Anderson II, Everett B; Haberman, David; Al-Hassin, Mowafak; He, Xiaoming; Morriseau, Brian

    2010-02-24

    future. Project partners also conducted a workshop on hydrogen safety and permitting. This provided an opportunity for the various permitting agencies and end users to gather to share experiences and knowledge. As a result of this workshop, the permitting process for the hydrogen filling station on the Las Vegas Valley Water District’s land was done more efficiently and those who would be responsible for the operation were better educated on the safety and reliability of hydrogen production and storage. The lessons learned in permitting the filling station and conducting this workshop provided a basis for future hydrogen projects in the region. Continuing efforts to increase the working pressure of electrolysis and efficiency have been pursued. Research was also performed on improving the cost, efficiency and durability of Proton Exchange Membrane (PEM) hydrogen technology. Research elements focused upon PEM membranes, electrodes/catalysts, membrane-electrode assemblies, seals, bipolar plates, utilization of renewable power, reliability issues, scale, and advanced conversion topics. Additionally, direct solar-to-hydrogen conversion research to demonstrate stable and efficient photoelectrochemistry (PEC) hydrogen production systems based on a number of optional concepts was performed. Candidate PEC concepts included technical obstacles such as inefficient photocatalysis, inadequate photocurrent due to non-optimal material band gap energies, rapid electron-hole recombination, reduced hole mobility and diminished operational lifetimes of surface materials exposed to electrolytes. Project Objective 1: Design, build, operate hydrogen filling station Project Objective 2: Perform research and development for utilizing solar technologies on the hydrogen filling station and convert two utility vehicles for use by the station operators Project Objective 3: Increase capacity of hydrogen filling station; add additional vehicle; conduct safety workshop; develop a roadmap for

  9. Protecting Neural Structures and Cognitive Function During Prolonged Space Flight by Targeting the Brain Derived Neurotrophic Factor Molecular Network

    Science.gov (United States)

    Schmidt, M. A.; Goodwin, T. J.

    2014-01-01

    Brain derived neurotrophic factor (BDNF) is the main activity-dependent neurotrophin in the human nervous system. BDNF is implicated in production of new neurons from dentate gyrus stem cells (hippocampal neurogenesis), synapse formation, sprouting of new axons, growth of new axons, sprouting of new dendrites, and neuron survival. Alterations in the amount or activity of BDNF can produce significant detrimental changes to cortical function and synaptic transmission in the human brain. This can result in glial and neuronal dysfunction, which may contribute to a range of clinical conditions, spanning a number of learning, behavioral, and neurological disorders. There is an extensive body of work surrounding the BDNF molecular network, including BDNF gene polymorphisms, methylated BDNF gene promoters, multiple gene transcripts, varied BDNF functional proteins, and different BDNF receptors (whose activation differentially drive the neuron to neurogenesis or apoptosis). BDNF is also closely linked to mitochondrial biogenesis through PGC-1alpha, which can influence brain and muscle metabolic efficiency. BDNF AS A HUMAN SPACE FLIGHT COUNTERMEASURE TARGET Earth-based studies reveal that BDNF is negatively impacted by many of the conditions encountered in the space environment, including oxidative stress, radiation, psychological stressors, sleep deprivation, and many others. A growing body of work suggests that the BDNF network is responsive to a range of diet, nutrition, exercise, drug, and other types of influences. This section explores the BDNF network in the context of 1) protecting the brain and nervous system in the space environment, 2) optimizing neurobehavioral performance in space, and 3) reducing the residual effects of space flight on the nervous system on return to Earth

  10. The impact of physicochemical and molecular properties in drug design: navigation in the "drug-like" chemical space.

    Science.gov (United States)

    Vallianatou, Theodosia; Giaginis, Costas; Tsantili-Kakoulidou, Anna

    2015-01-01

    Physicochemical and molecular properties influence both pharmacokinetic and pharmacodynamic process, as well as drug safety, often in a conflicting way. In this aspect the current trend in drug discovery is to consider ADME (T) properties in parallel with target affinity. The concept of "drug-likeness" defines acceptable boundaries of fundamental properties formulated as simple rules of thumb, in order to aid the medicinal chemist to prioritize drug candidates. Special attention is given to lipophilicity and molecular weight, since there is a tendency for those parameters to increase in regard to complex compounds generated by new technologies, with potential consequences in bioavailability, while high lipophilicity is also associated with undesired effects. Such rules have the advantage to be very simple and are easy to interpret; however their drawback is that they do not take into consideration uncertainties in measurements and calculations as well as the receptor requirements. The case of PPARs, a nuclear receptor family, is discussed in detail in regard to the chemical space covered by the ligands, focusing on the high demands of the ligand binding domain in both lipophilicity and molecular size. Such paradigms indicate that it would be more appropriate to adapt drug-like properties according to specific drug discovery projects.

  11. Spaces

    Directory of Open Access Journals (Sweden)

    Maziar Nekovee

    2010-01-01

    Full Text Available Cognitive radio is being intensively researched as the enabling technology for license-exempt access to the so-called TV White Spaces (TVWS, large portions of spectrum in the UHF/VHF bands which become available on a geographical basis after digital switchover. Both in the US, and more recently, in the UK the regulators have given conditional endorsement to this new mode of access. This paper reviews the state-of-the-art in technology, regulation, and standardisation of cognitive access to TVWS. It examines the spectrum opportunity and commercial use cases associated with this form of secondary access.

  12. Preparing for faster filling

    CERN Multimedia

    CERN Bulletin

    2010-01-01

    Following the programmed technical stop last week, operators focussed on preparing the machine for faster filling, which includes multibunch injection and a faster pre-cycle phase.   The LHC1 screen shot during the first multibunch injection operation. The LHC operational schedule incorporates a technical stop for preventive maintenance roughly every six weeks of stable operation, during which several interventions on the various machines are carried out. Last week these included the replacement of a faulty magnet in the SPS pre-accelerator, which required the subsequent re-setting of the system of particle extraction and transfer to the LHC. At the end of last week, all the machines were handed back for operation and work could start on accommodating all the changes made into the complex systems in order for normal operation to be resumed. These ‘recovery’ operations continued through the weekend and into this week. At the beginning of this week, operators succeeded in pro...

  13. A Molecular Dynamics Approach to Grain Boundary Structure and Migration

    DEFF Research Database (Denmark)

    Cotterill, R. M. J.; Leffers, Torben; Lilholt, Hans

    1974-01-01

    It has been demonstrated that grain boundary formation from the melt can be simulated by the molecular dynamics method. The space between two mutually-misoriented crystal slabs was filled with atoms in a random manner and this liquid was then cooled until crystallization occurred. The general...

  14. Bulk-Fill Resin Composites

    DEFF Research Database (Denmark)

    Benetti, Ana Raquel; Havndrup-Pedersen, Cæcilie; Honoré, Daniel

    2015-01-01

    the restorative procedure. The aim of this study, therefore, was to compare the depth of cure, polymerization contraction, and gap formation in bulk-fill resin composites with those of a conventional resin composite. To achieve this, the depth of cure was assessed in accordance with the International Organization...... for Standardization 4049 standard, and the polymerization contraction was determined using the bonded-disc method. The gap formation was measured at the dentin margin of Class II cavities. Five bulk-fill resin composites were investigated: two high-viscosity (Tetric EvoCeram Bulk Fill, SonicFill) and three low......-viscosity (x-tra base, Venus Bulk Fill, SDR) materials. Compared with the conventional resin composite, the high-viscosity bulk-fill materials exhibited only a small increase (but significant for Tetric EvoCeram Bulk Fill) in depth of cure and polymerization contraction, whereas the low-viscosity bulk...

  15. Probing the bioactivity-relevant chemical space of robust reactions and common molecular building blocks.

    Science.gov (United States)

    Hartenfeller, Markus; Eberle, Martin; Meier, Peter; Nieto-Oberhuber, Cristina; Altmann, Karl-Heinz; Schneider, Gisbert; Jacoby, Edgar; Renner, Steffen

    2012-05-25

    In the search for new bioactive compounds, there is a trend toward increasingly complex compound libraries aiming to target the demanding targets of the future. In contrast, medicinal chemistry and traditional library design rely mainly on a small set of highly established and robust reactions. Here, we probe a set of 58 such reactions for their ability to sample the chemical space of known bioactive molecules, and the potential to create new scaffolds. Combined with ~26,000 common available building blocks, the reactions retrieve around 9% of a scaffold-diverse set of compounds active on human target proteins covering all major pharmaceutical target classes. Almost 80% of generated scaffolds from virtual one-step synthesis products are not present in a large set of known bioactive molecules for human targets, indicating potential for new discoveries. The results suggest that established synthesis resources are well suited to cover the known bioactivity-relevant chemical space and that there are plenty of unexplored regions accessible by these reactions, possibly providing valuable "low-hanging fruit" for hit discovery.

  16. Exploring the molecular mechanisms of electron shuttling across the microbe/metal space

    Directory of Open Access Journals (Sweden)

    Catarina M Paquete

    2014-06-01

    Full Text Available Dissimilatory metal reducing organisms play key roles in the biogeochemical cycle of metals as well as in the durability of submerged and buried metallic structures. The molecular mechanisms that support electron transfer across the microbe-metal interface in these organisms remain poorly explored. It is known that outer membrane proteins, in particular multiheme cytochromes, are essential for this type of metabolism, being responsible for direct and indirect, via electron shuttles, interaction with the insoluble electron acceptors. Soluble electron shuttles such as flavins, phenazines and humic acids are known to enhance extracellular electron transfer. In this work, this phenomenon was explored. All known outer membrane decaheme cytochromes from Shewanella oneidensis MR-1 with known metal terminal reductase activity and a undecaheme cytochrome from Shewanella sp. HRCR-6 were expressed and purified. Their interactions with soluble electron shuttles were studied using stopped-flow kinetics, NMR spectroscopy and molecular simulations. The results show that despite the structural similarities, expected from the available structural data and sequence homology, the detailed characteristics of their interactions with soluble electron shuttles are different. MtrC and OmcA appear to interact with a variety of different electron shuttles in the close vicinity of some of their hemes, and with affinities that are biologically relevant for the concentrations typical found in the medium for this type of compounds. All data support a view of a distant interaction between the hemes of MtrF and the electron shuttles. For UndA a clear structural characterization was achieved for the interaction with AQDS a humic acid analogue. These results provide guidance for future work of the manipulation of these proteins toward modulation of their role in metal attachment and reduction.

  17. Exploring the molecular mechanisms of electron shuttling across the microbe/metal space.

    Science.gov (United States)

    Paquete, Catarina M; Fonseca, Bruno M; Cruz, Davide R; Pereira, Tiago M; Pacheco, Isabel; Soares, Cláudio M; Louro, Ricardo O

    2014-01-01

    Dissimilatory metal reducing organisms play key roles in the biogeochemical cycle of metals as well as in the durability of submerged and buried metallic structures. The molecular mechanisms that support electron transfer across the microbe-metal interface in these organisms remain poorly explored. It is known that outer membrane proteins, in particular multiheme cytochromes, are essential for this type of metabolism, being responsible for direct and indirect, via electron shuttles, interaction with the insoluble electron acceptors. Soluble electron shuttles such as flavins, phenazines, and humic acids are known to enhance extracellular electron transfer. In this work, this phenomenon was explored. All known outer membrane decaheme cytochromes from Shewanella oneidensis MR-1 with known metal terminal reductase activity and a undecaheme cytochrome from Shewanella sp. HRCR-6 were expressed and purified. Their interactions with soluble electron shuttles were studied using stopped-flow kinetics, NMR spectroscopy, and molecular simulations. The results show that despite the structural similarities, expected from the available structural data and sequence homology, the detailed characteristics of their interactions with soluble electron shuttles are different. MtrC and OmcA appear to interact with a variety of different electron shuttles in the close vicinity of some of their hemes, and with affinities that are biologically relevant for the concentrations typical found in the medium for this type of compounds. All data support a view of a distant interaction between the hemes of MtrF and the electron shuttles. For UndA a clear structural characterization was achieved for the interaction with AQDS a humic acid analog. These results provide guidance for future work of the manipulation of these proteins toward modulation of their role in metal attachment and reduction.

  18. Measuring the number and spacing of molecular motors propelling a gliding microtubule

    Science.gov (United States)

    Fallesen, Todd L.; Macosko, Jed C.; Holzwarth, G.

    2011-01-01

    The molecular motor gliding assay, in which a microtubule or other filament moves across a surface coated with motors, has provided much insight into how molecular motors work. The kinesin-microtubule system is also a strong candidate for the job of nanoparticle transporter in nanotechnology devices. In most cases, several motors transport each filament. Each motor serves both to bind the microtubule to a stationary surface and to propel the microtubule along the surface. By applying a uniform transverse force of 4-19 pN to a superparamagnetic bead attached to the trailing end of the microtubule, we have measured the distance d between binding points (motors). The average value of d was determined as a function of motor surface density σ. The measurements agree well with the scaling model of Duke, Holy, and Liebler, which predicts that ~σ-2/5 if 0.05⩽σ⩽20μm-2 [Phys. Rev. Lett.PRLTAO0031-900710.1103/PhysRevLett.74.330 74, 330 (1995)]. The distribution of d fits an extension of the model. The radius of curvature of a microtubule bent at a binding point by the force of the magnetic bead was ≈1 μm, 5000-fold smaller than the radius of curvature of microtubules subjected only to thermal forces. This is evidence that at these points of high bending stress, generated by the force on the magnetic bead, the microtubule is in the more flexible state of a two-state model of microtubule bending proposed by Heussinger, Schüller, and Frey [Phys. Rev. EPLEEE81063-651X10.1103/PhysRevE.81.021904 81, 021904 (2010)].

  19. Applications of space-electrophoresis in medicine. [for cellular separations in molecular biology

    Science.gov (United States)

    Bier, M.

    1976-01-01

    The nature of electrophoresis is reviewed and potential advances realizable in the field of biology and medicine from a space electrophoresis facility are examined. The ground-based applications of electrophoresis: (1) characterization of an ionized species; (2) determination of the quantitative composition of a complex mixture; and (3) isolation of the components of a mixture, separation achieved on the basis of the difference in transport rates is reviewed. The electrophoresis of living cells is considered, touching upon the following areas: the separation of T and B lymphocytes; the genetic influence on mouse lymphocyte mobilities; the abnormal production of specific and monoclonal immunoproteins; and the study of cancer. Schematic diagrams are presented of three types of electrophoresis apparatus: the column assembly for the static electrophoresis experiment on the Apollo-Soyuz mission, the continuous flow apparatus used in the same mission and a miniaturized electrophoresis apparatus.

  20. Stockholder projector analysis: a Hilbert-space partitioning of the molecular one-electron density matrix with orthogonal projectors.

    Science.gov (United States)

    Vanfleteren, Diederik; Van Neck, Dimitri; Bultinck, Patrick; Ayers, Paul W; Waroquier, Michel

    2012-01-07

    A previously introduced partitioning of the molecular one-electron density matrix over atoms and bonds [D. Vanfleteren et al., J. Chem. Phys. 133, 231103 (2010)] is investigated in detail. Orthogonal projection operators are used to define atomic subspaces, as in Natural Population Analysis. The orthogonal projection operators are constructed with a recursive scheme. These operators are chemically relevant and obey a stockholder principle, familiar from the Hirshfeld-I partitioning of the electron density. The stockholder principle is extended to density matrices, where the orthogonal projectors are considered to be atomic fractions of the summed contributions. All calculations are performed as matrix manipulations in one-electron Hilbert space. Mathematical proofs and numerical evidence concerning this recursive scheme are provided in the present paper. The advantages associated with the use of these stockholder projection operators are examined with respect to covalent bond orders, bond polarization, and transferability.

  1. Protein formulation and fill-finish operations.

    Science.gov (United States)

    Patro, Sugunakar Y; Freund, Erwin; Chang, Byeong S

    2002-01-01

    One of the challenges for the successful commercialization of therapeutic proteins is to maintain the safety and efficacy of the protein during the manufacturing process, storage, and administration. To achieve this, the purified form of the protein drug is usually "formulated" with carefully selected excipients. The operations that occur subsequent to protein purification, such as freezing of the purified protein bulk, thawing of the bulk, formulation (excipient addition), sterile filtration, filling, freeze-drying, and inspection are commonly referred as "formulation and fill-finish operations". This review is focused on the protein formulation and fill-finish operations, critical process parameters at each operation, and the process considerations required for maintaining safety and efficacy of the drug during manufacturing and storage. Since proteins have complex molecular structures that can influence the protein stability, the reader is first introduced to salient concepts related to protein structure. This is followed by a review of the possible protein-degradation mechanisms and how a variety of external factors can contribute to protein degradation during the in vitro processing of the protein drug. The reader is then introduced to each of the formulation and fill-finish operations mentioned above, the possible degradations during each unit-operation, and process considerations necessary to avoid those degradations.

  2. Detectability of molecular gas signatures on Jupiter’s moon Europa from ground and space-based facilities

    Science.gov (United States)

    Paganini, Lucas; Villanueva, Geronimo Luis; Hurford, Terry; Mandell, Avi; Roth, Lorenz; Mumma, Michael J.

    2017-10-01

    Plumes and their effluent material could provide insights into Europa’s subsurface chemistry and relevant information about the prospect that life could exist, or now exists, within the ocean. In 2016, we initiated a strong observational campaign to characterize the chemical composition of Europa’s surface and exosphere using high-resolution infrared spectroscopy. While several studies have focused on the detection of water, or its dissociation products, there could be a myriad of complex molecules released by erupting plumes. Our IR survey has provided a serendipitous search for several key molecular species, allowing a chemical characterization that can aid the investigation of physical processes underlying its surface. Since our tentative water detection, presented at the 2016 DPS meeting, we have continued the observations of Europa during 2017 covering a significant extent of the moon’s terrain and orbital position (true anomaly), accounting for over 50 hr on source. Current analyses of these data are showing spectral features that grant further investigation. In addition to analysis algorithms tailored to the examination of Europan data, we have developed simulation tools to predict the possible detection of molecular species using ground-based facilities like the Keck Observatory, NASA’s Infrared Telescope and the Atacama Large Millimeter/submillimeter Array (ALMA). In this presentation we will discuss the detectability of key molecular species with these remote sensing facilities, as well as expected challenges and future strategies with upcoming spacecrafts such as the James Webb Space Telescope (JWST), the Large UV/Optical/Infrared Surveyor (LUVOIR), and a possible gas spectrometer onboard an orbiter.This work is supported by NASA’s Keck PI Data Award (PI L.P.) and Solar System Observation Program (PI L.P.), and by the NASA Astrobiology Institute through funding awarded to the Goddard Center for Astrobiology (PI M.J.M.).

  3. Restricted active space calculations of L-edge X-ray absorption spectra: from molecular orbitals to multiplet states.

    Science.gov (United States)

    Pinjari, Rahul V; Delcey, Mickaël G; Guo, Meiyuan; Odelius, Michael; Lundberg, Marcus

    2014-09-28

    The metal L-edge (2p → 3d) X-ray absorption spectra are affected by a number of different interactions: electron-electron repulsion, spin-orbit coupling, and charge transfer between metal and ligands, which makes the simulation of spectra challenging. The core restricted active space (RAS) method is an accurate and flexible approach that can be used to calculate X-ray spectra of a wide range of medium-sized systems without any symmetry constraints. Here, the applicability of the method is tested in detail by simulating three ferric (3d(5)) model systems with well-known electronic structure, viz., atomic Fe(3+), high-spin [FeCl6](3-) with ligand donor bonding, and low-spin [Fe(CN)6](3-) that also has metal backbonding. For these systems, the performance of the core RAS method, which does not require any system-dependent parameters, is comparable to that of the commonly used semi-empirical charge-transfer multiplet model. It handles orbitally degenerate ground states, accurately describes metal-ligand interactions, and includes both single and multiple excitations. The results are sensitive to the choice of orbitals in the active space and this sensitivity can be used to assign spectral features. A method has also been developed to analyze the calculated X-ray spectra using a chemically intuitive molecular orbital picture.

  4. A simple molecular mechanics integrator in mixed rigid body and dihedral angle space

    Energy Technology Data Exchange (ETDEWEB)

    Vitalis, Andreas, E-mail: a.vitalis@bioc.uzh.ch [Department of Biochemistry, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich (Switzerland); Pappu, Rohit V. [Department of Biomedical Engineering and Center for Biological Systems Engineering, Washington University in St. Louis, One Brookings Drive, Campus Box 1097, St. Louis, Missouri 63130 (United States)

    2014-07-21

    We propose a numerical scheme to integrate equations of motion in a mixed space of rigid-body and dihedral angle coordinates. The focus of the presentation is biomolecular systems and the framework is applicable to polymers with tree-like topology. By approximating the effective mass matrix as diagonal and lumping all bias torques into the time dependencies of the diagonal elements, we take advantage of the formal decoupling of individual equations of motion. We impose energy conservation independently for every degree of freedom and this is used to derive a numerical integration scheme. The cost of all auxiliary operations is linear in the number of atoms. By coupling the scheme to one of two popular thermostats, we extend the method to sample constant temperature ensembles. We demonstrate that the integrator of choice yields satisfactory stability and is free of mass-metric tensor artifacts, which is expected by construction of the algorithm. Two fundamentally different systems, viz., liquid water and an α-helical peptide in a continuum solvent are used to establish the applicability of our method to a wide range of problems. The resultant constant temperature ensembles are shown to be thermodynamically accurate. The latter relies on detailed, quantitative comparisons to data from reference sampling schemes operating on exactly the same sets of degrees of freedom.

  5. A simple molecular mechanics integrator in mixed rigid body and dihedral angle space.

    Science.gov (United States)

    Vitalis, Andreas; Pappu, Rohit V

    2014-07-21

    We propose a numerical scheme to integrate equations of motion in a mixed space of rigid-body and dihedral angle coordinates. The focus of the presentation is biomolecular systems and the framework is applicable to polymers with tree-like topology. By approximating the effective mass matrix as diagonal and lumping all bias torques into the time dependencies of the diagonal elements, we take advantage of the formal decoupling of individual equations of motion. We impose energy conservation independently for every degree of freedom and this is used to derive a numerical integration scheme. The cost of all auxiliary operations is linear in the number of atoms. By coupling the scheme to one of two popular thermostats, we extend the method to sample constant temperature ensembles. We demonstrate that the integrator of choice yields satisfactory stability and is free of mass-metric tensor artifacts, which is expected by construction of the algorithm. Two fundamentally different systems, viz., liquid water and an α-helical peptide in a continuum solvent are used to establish the applicability of our method to a wide range of problems. The resultant constant temperature ensembles are shown to be thermodynamically accurate. The latter relies on detailed, quantitative comparisons to data from reference sampling schemes operating on exactly the same sets of degrees of freedom.

  6. Intermittent Surface Water Connectivity: Fill and Spill vs. Fill ...

    Science.gov (United States)

    Intermittent surface connectivity can influence aquatic systems, since chemical and biotic movements are often associated with water flow. Although often referred to as fill and spill, wetlands also fill and merge. We examined the effects of these connection types on water levels, ion concentrations, and biotic communities of eight prairie pothole wetlands between 1979 and 2015. Fill and spill caused pulsed surface water connections that were limited to periods following spring snow melt. In contrast, two wetlands connected through fill and merge experienced a nearly continuous, 20-year surface water connection and had completely coincident water levels. Fill and spill led to minimal convergence in dissolved ions and macroinvertebrate composition, while these constituents converged under fill and merge. The primary factor determining difference in responses was duration of the surface water connection between wetland pairs. Our findings suggest that investigations into the effects of intermittent surface water connections should not consider these connections generically, but need to address the specific types of connections. In particular, fill and spill promotes external water exports while fill and merge favors internal storage. The behaviors of such intermittent connections will likely be accentuated under a future with more frequent and severe climate extremes. Under the Safe and Sustainable Water Resources National Program, work is being done to qu

  7. Monodisperse liquid-filled biodegradable microcapsules.

    Science.gov (United States)

    Berkland, Cory; Pollauf, Emily; Varde, Neel; Pack, Daniel W; Kim, Kyekyoon Kevin

    2007-05-01

    Encapsulation of liquids into biodegradable polymer microcapsules has been a challenging task due to production limitations stemming from solution viscosity, phase stabilization, molecular localization, and scalable production. We report an extension of Precision Particle Fabrication (PPF) technology for the production of monodisperse liquid-filled microcapsules containing an oil or aqueous core and contrast these results to double-walled microspheres. PPF technology utilizes a coaxial nozzle to produce a liquid core jet surrounded by a polymer annular jet, which is further encompassed by a non-solvent carrier stream, typically 0.5% wt/vol polyvinyl alcohol in water. Jet diameters are controlled by the volumetric flow rate of each phase. The compound jet is then disrupted into uniform core/shell droplets via a controllable acoustic wave and shell material is hardened by solvent extraction. Monodisperse polymeric microcapsules demonstrated a narrow size distribution and the formation of a continuous shell leading to efficient encapsulation of various liquid cores. The intermingling of core and shell phases and the localization of different molecular probes (fluorescent dyes and fluorescently labeled proteins) to the core or shell phase provided additional evidence of phase separation and molecular partitioning, respectively. We also demonstrate the pulsatile release of bovine serum albumin encapsulated in an aqueous core. PPF technology provided exceptional control of the overall size and shell thickness of microcapsules filled with various types of oil or water. This technique may enable advanced delivery profiles of pharmaceuticals or nutraceuticals.

  8. Removal of root filling materials.

    LENUS (Irish Health Repository)

    Duncan, H.F. Chong, B.S.

    2011-05-01

    Safe, successful and effective removal of root filling materials is an integral component of non-surgical root canal re-treatment. Access to the root canal system must be achieved in order to negotiate to the canal terminus so that deficiencies in the original treatment can be rectified. Since a range of materials have been advocated for filling root canals, different techniques are required for their removal. The management of commonly encountered root filling materials during non-surgical re-treatment, including the clinical procedures necessary for removal and the associated risks, are reviewed. As gutta-percha is the most widely used and accepted root filling material, there is a greater emphasis on its removal in this review.

  9. Budgeting Academic Space

    Science.gov (United States)

    Harris, Watson

    2011-01-01

    There are many articles about space management, including those that discuss space calculations, metrics, and categories. Fewer articles discuss the space budgeting processes used by administrators to allocate space. The author attempts to fill this void by discussing her administrative experiences with Middle Tennessee State University's (MTSU)…

  10. Paleovalley fills: Trunk vs. tributary

    Science.gov (United States)

    Kvale, E.P.; Archer, A.W.

    2007-01-01

    A late Mississippian-early Pennsylvanian eustatic sea level drop resulted in a complex lowstand drainage network being eroded across the Illinois Basin in the eastern United States. This drainage system was filled during the early part of the Pennsylvanian. Distinct differences can be recognized between the trunk and tributary paleovalley fills. Fills preserved within the trunk systems tend to be fluvially dominated and consist of bed-load deposits of coarse- to medium-grained sandstone and conglomerate. Conversely, the incised valleys of tributary systems tend to be filled with dark mudstone, thinly interbedded sandstones, and mudstones and siltstones. These finer grained facies exhibit marine influences manifested by tidal rhythmites, certain traces fossils, and macro- and microfauna. Examples of tributary and trunk systems, separated by no more than 7 km (4.3 mi) along strike, exhibit these styles of highly contrasting fills. Useful analogs for understanding this Pennsylvanian system include the Quaternary glacial sluiceways present in the lower Ohio, White, and Wabash river valleys of Indiana (United States) and the modern Amazon River (Brazil). Both the Amazon River and the Quaternary rivers of Indiana have (or had) trunk rivers that are (were) dominated by large quantities of bed load relative to their tributaries. The trunk valley systems of these analogs aggraded much more rapidly than their tributary valleys, which evolved into lakes because depositional rates along the trunk are (were) so high that the mouths of the tributaries have been dammed by bed-load deposits. These Holocene systems illustrate that sediment yields can significantly influence the nature of fill successions within incised valleys independent of rates of sea level changes or proximity to highstand coastlines. Copyright ?? 2007. The American Association of Petroleum Geologists. All rights reserved.

  11. Filled and empty states of carbon nanotubes in water: Dependence ...

    Indian Academy of Sciences (India)

    We have carried out a series of molecular dynamics simulations of water containing a narrow carbon nanotube as a solute to investigate the filling and emptying of the nanotube and also the modifications of the density and hydrogen bond distributions of water inside and also in the vicinity of the outer surfaces of the ...

  12. Gas-Filled Capillary Model

    Science.gov (United States)

    Steinhauer, L. C.; Kimura, W. D.

    2006-11-01

    We have developed a 1-D, quasi-steady-state numerical model for a gas-filled capillary discharge that is designed to aid in selecting the optimum capillary radius in order to guide a laser beam with the required intensity through the capillary. The model also includes the option for an external solenoid B-field around the capillary, which increases the depth of the parabolic density channel in the capillary, thereby allowing for propagation of smaller laser beam waists. The model has been used to select the parameters for gas-filled capillaries to be utilized during the Staged Electron Laser Acceleration — Laser Wakefield (STELLA-LW) experiment.

  13. QENS investigation of filled rubbers

    CERN Document Server

    Triolo, A; Desmedt, A; Pieper, J K; Lo Celso, F; Triolo, R; Negroni, F; Arrighi, V; Qian, H; Frick, B

    2002-01-01

    The polymer segmental dynamics is investigated in a series of silica-filled rubbers. The presence of inert fillers in polymers greatly affects the mechanical and physical performance of the final materials. For example, silica has been proposed as a reinforcing agent of elastomers in tire production. Results from quasielastic neutron scattering and Dynamic Mechanical Thermal Analysis (DMTA) measurements are presented on styrene-ran-butadiene rubber filled with silica. A clear indication is obtained of the existence of a bimodal dynamics, which can be rationalized in terms of the relaxation of bulk rubber and the much slower relaxation of the rubber adsorbed on the filler surface. (orig.)

  14. Contemporary root canal filling strategies

    NARCIS (Netherlands)

    Moinzadeh, A.T.

    2016-01-01

    Currently, clinicians can choose from a wide range of root canal filling materials and techniques, some of which have been evaluated in this thesis. Methacrylate resin-based sealers suffer from polymerization shrinkage stresses. This limitation may partly be overcome by a two-step cementation

  15. Can-Filled Crash Barrier

    Science.gov (United States)

    Wilson, A. H.

    1983-01-01

    Crash barrier composed largely of used aluminum beverage cans protects occupants of cars in collisions with poles or trees. Lightweight, can-filled barrier very effective in softening impact of an automobile in head-on and off-angle collisions. Preliminary results indicate barrier is effective in collisions up to 40 mi/h (64 km/h).

  16. Brain Responses to Filled Gaps

    Science.gov (United States)

    Hestvik, Arild; Maxfield, Nathan; Schwartz, Richard G.; Shafer, Valerie

    2007-01-01

    An unresolved issue in the study of sentence comprehension is whether the process of gap-filling is mediated by the construction of empty categories (traces), or whether the parser relates fillers directly to the associated verb's argument structure. We conducted an event-related potentials (ERP) study that used the violation paradigm to examine…

  17. Directional molecular flow analysis and leak detection with a rotatable gas analyzer in a large space simulation chamber

    Science.gov (United States)

    Ehlers, H. K. F.

    1972-01-01

    A system was developed and applied at the NASA Manned Spacecraft Center for measuring and analyzing directional molecular flows in a large thermal vacuum chamber in order to verify molecular environment and identify characteristic and abnormal test article and chamber conditions. The system is described, and some results obtained in over 1200 hours of operation are given.

  18. Space space space

    CERN Document Server

    Trembach, Vera

    2014-01-01

    Space is an introduction to the mysteries of the Universe. Included are Task Cards for independent learning, Journal Word Cards for creative writing, and Hands-On Activities for reinforcing skills in Math and Language Arts. Space is a perfect introduction to further research of the Solar System.

  19. Particle-filled microporous materials

    Science.gov (United States)

    McAllister, Jerome W.; Kinzer, Kevin E.; Mrozinski, James S.; Johnson, Eric J.; Dyrud, James F.

    1990-01-01

    A microporous particulate-filled thermoplastic polymeric article is provided. The article can be in the form of a film, a fiber, or a tube. The article has a thermoplastic polymeric structure having a plurality of interconnected passageways to provide a network of communicating pores. The microporous structure contains discrete submicron or low micron-sized particulate filler, the particulate filler being substantially non-agglomerated.

  20. Molecular similarity analysis and virtual screening by mapping of consensus positions in binary-transformed chemical descriptor spaces with variable dimensionality.

    Science.gov (United States)

    Godden, Jeffrey W; Furr, John R; Xue, Ling; Stahura, Florence L; Bajorath, Jürgen

    2004-01-01

    A novel compound classification algorithm is described that operates in binary molecular descriptor spaces and groups active compounds together in a computationally highly efficient manner. The method involves the transformation of continuous descriptor value ranges into a binary format, subsequent definition of simplified descriptor spaces, identification of consensus positions of specific compound sets in these spaces, and iterative adjustments of the dimensionality of the descriptor spaces in order to discriminate compounds sharing similar activity from others. We term this approach Dynamic Mapping of Consensus positions (DMC) because the definition of reference spaces is tuned toward specific compound classes and their dimensionality is increased as the analysis proceeds. When applied to virtual screening, sets of bait compounds are added to a large screening database to identify hidden active molecules. In these calculations, molecules that map to consensus positions after elimination of most of the database compounds are considered hit candidates. In a benchmark study on five biological activity classes, hits for randomly assembled sets of bait molecules were correctly identified in 95% of virtual screening calculations in a source database containing more than 1.3 million molecules, thus providing a measure of the sensitivity of the DMC technique.

  1. The Use of the Molecular Adsorber Coating Technology to Mitigate Vacuum Chamber Contamination During Pathfinder Testing for the James Webb Space Telescope

    Science.gov (United States)

    Abraham, Nithin S.; Hasegawa, Mark M.; Wooldridge, Eve M.; Henderson-Nelson, Kelly A.

    2016-01-01

    As a coating made of highly porous zeolite materials, the Molecular Adsorber Coating (MAC) was developed to capture outgassed molecular contaminants, such as hydrocarbons and silicones. For spaceflight applications, the adsorptive capabilities of the coating can alleviate on-orbit outgassing concerns on or near sensitive surfaces and instruments within the spacecraft. Similarly, this sprayable paint technology has proven to be significantly beneficial for ground based space applications, in particular, for vacuum chamber environments. This paper describes the recent use of the MAC technology during Pathfinder testing of the Optical Ground Support Equipment (OGSE) for the James Webb Space Telescope (JWST) at NASA Johnson Space Center (JSC). The coating was used as a mitigation tool to entrap persistent outgassed contaminants, specifically silicone based diffusion pump oil, from within JSC's cryogenic optical vacuum chamber test facility called Chamber A. This paper summarizes the sample fabrication, installation, laboratory testing, post-test chemical analysis results, and future plans for the MAC technology, which was effectively used to protect the JWST test equipment from vacuum chamber contamination.

  2. The use of the Molecular Adsorber Coating technology to mitigate vacuum chamber contamination during Pathfinder testing for the James Webb Space Telescope

    Science.gov (United States)

    Abraham, Nithin S.; Hasegawa, Mark M.; Wooldridge, Eve M.; Henderson-Nelson, Kelly A.

    2016-09-01

    As a coating made of highly porous zeolite materials, the Molecular Adsorber Coating (MAC) was developed to capture outgassed molecular contaminants, such as hydrocarbons and silicones. For spaceflight applications, the adsorptive capabilities of the coating can alleviate on-orbit outgassing concerns on or near sensitive surfaces and instruments within the spacecraft. Similarly, this sprayable paint technology has proven to be significantly beneficial for ground based space applications, in particular, for vacuum chamber environments. This paper describes the recent use of the MAC technology during Pathfinder testing of the Optical Ground Support Equipment (OGSE) for the James Webb Space Telescope (JWST) at NASA Johnson Space Center (JSC). The coating was used as a mitigation tool to entrap persistent outgassed contaminants, specifically silicone based diffusion pump oil, from within JSC's cryogenic optical vacuum chamber test facility called Chamber A. This paper summarizes the sample fabrication, installation, laboratory testing, post-test chemical analysis results, and future plans for the MAC technology, which was effectively used to protect the JWST test equipment from vacuum chamber contamination.

  3. Some design and applying aspects of Molecular Beam Epitaxy (MBE) machine Main Units in Ultra-Vacuum of Space

    Science.gov (United States)

    Pridachin, D. N.; Pchelyakov, O. P.; Nikiforov, A. I.; Sokolov, L. V.; Preobrazhenskii, V. V.; Blinov, V. V.

    2017-09-01

    In the given report the System of growing and processing materials (film coverings) in a Space in the ultrahigh vacuum conditions, a way of its operation and its terrestrial stand-simulator for testing the device are presented.

  4. Biocytin Filling of Adult Gonadotropin-Releasing Hormone Neurons in Situ Reveals Extensive, Spiny, Dendritic Processes

    National Research Council Canada - National Science Library

    Campbell, Rebecca E; Han, Seong-Kyu; Herbison, Allan E

    2005-01-01

    .... Using acute brain slices prepared from transgenic GnRH-green fluorescent protein mice, individual fluorescing GnRH neurons were identified, patched, and filled with the small-molecular-weight dye biocytin...

  5. Filling patterns in contrast ventriculography

    Science.gov (United States)

    Ferguson, Lawrence

    1974-01-01

    The filling patterns of a negative contrast material (air), a positive contrast water soluble material (Conray), and a positive contrast water insoluble material (Myodil) were examined in 60 normal ventriculograms. Using a scoring system developed for this study, Conray was found effective for outlining the ipsilateral (injected) lateral ventricle, the third ventricle, the aqueduct of Sylvius, and the fourth ventricle. Air was the most effective for the noninjected lateral ventricle, while Myodil was best for A-P demonstration of the aqueduct. The clinical implications of these findings are discussed. PMID:4545798

  6. Vacuum space charge effects in sub-picosecond soft X-ray photoemission on a molecular adsorbate layer

    Directory of Open Access Journals (Sweden)

    M. Dell'Angela

    2015-03-01

    Full Text Available Vacuum space charge induced kinetic energy shifts of O 1s and Ru 3d core levels in femtosecond soft X-ray photoemission spectra (PES have been studied at a free electron laser (FEL for an oxygen layer on Ru(0001. We fully reproduced the measurements by simulating the in-vacuum expansion of the photoelectrons and demonstrate the space charge contribution of the high-order harmonics in the FEL beam. Employing the same analysis for 400 nm pump-X-ray probe PES, we can disentangle the delay dependent Ru 3d energy shifts into effects induced by space charge and by lattice heating from the femtosecond pump pulse.

  7. Vacuum space charge effects in sub-picosecond soft X-ray photoemission on a molecular adsorbate layer.

    Science.gov (United States)

    Dell'Angela, M; Anniyev, T; Beye, M; Coffee, R; Föhlisch, A; Gladh, J; Kaya, S; Katayama, T; Krupin, O; Nilsson, A; Nordlund, D; Schlotter, W F; Sellberg, J A; Sorgenfrei, F; Turner, J J; Öström, H; Ogasawara, H; Wolf, M; Wurth, W

    2015-03-01

    Vacuum space charge induced kinetic energy shifts of O 1s and Ru 3d core levels in femtosecond soft X-ray photoemission spectra (PES) have been studied at a free electron laser (FEL) for an oxygen layer on Ru(0001). We fully reproduced the measurements by simulating the in-vacuum expansion of the photoelectrons and demonstrate the space charge contribution of the high-order harmonics in the FEL beam. Employing the same analysis for 400 nm pump-X-ray probe PES, we can disentangle the delay dependent Ru 3d energy shifts into effects induced by space charge and by lattice heating from the femtosecond pump pulse.

  8. Bio-inspired dental fillings

    Science.gov (United States)

    Deyhle, Hans; Bunk, Oliver; Buser, Stefan; Krastl, Gabriel; Zitzmann, Nicola U.; Ilgenstein, Bernd; Beckmann, Felix; Pfeiffer, Franz; Weiger, Roland; Müller, Bert

    2009-08-01

    Human teeth are anisotropic composites. Dentin as the core material of the tooth consists of nanometer-sized calcium phosphate crystallites embedded in collagen fiber networks. It shows its anisotropy on the micrometer scale by its well-oriented microtubules. The detailed three-dimensional nanostructure of the hard tissues namely dentin and enamel, however, is not understood, although numerous studies on the anisotropic mechanical properties have been performed and evaluated to explain the tooth function including the enamel-dentin junction acting as effective crack barrier. Small angle X-ray scattering (SAXS) with a spatial resolution in the 10 μm range allows determining the size and orientation of the constituents on the nanometer scale with reasonable precision. So far, only some dental materials, i.e. the fiber reinforced posts exhibit anisotropic properties related to the micrometer-size glass fibers. Dental fillings, composed of nanostructures oriented similar to the natural hard tissues of teeth, however, do not exist at all. The current X-ray-based investigations of extracted human teeth provide evidence for oriented micro- and nanostructures in dentin and enamel. These fundamental quantitative findings result in profound knowledge to develop biologically inspired dental fillings with superior resistance to thermal and mechanical shocks.

  9. Rice Husk Filled Polymer Composites

    Directory of Open Access Journals (Sweden)

    Reza Arjmandi

    2015-01-01

    Full Text Available Natural fibers from agricultural wastes are finding their importance in the polymer industry due to the many advantages such as their light weight, low cost and being environmentally friendly. Rice husk (RH is a natural sheath that forms around rice grains during their growth. As a type of natural fiber obtained from agroindustrial waste, RH can be used as filler in composites materials in various polymer matrices. This review paper is aimed at highlighting previous works of RH filled polymer composites to provide information for applications and further research in this area. Based on the information gathered, application of RH filled composites as alternative materials in building and construction is highly plausible with both light weight and low cost being their main driving forces. However, further investigations on physical and chemical treatment to further improve the interfacial adhesion with polymeric matrix are needed as fiber-polymer interaction is crucial in determining the final composite properties. Better understanding on how the used polymer blends as the matrix and secondary fillers may affect the properties would provide interesting areas to be explored.

  10. Silicone Gel-Filled Breast Implants

    Science.gov (United States)

    ... Medical Procedures Implants and Prosthetics Breast Implants Silicone Gel-Filled Breast Implants Share Tweet Linkedin Pin it ... options Linkedin Pin it Email Print Description: Silicone gel-filled breast implants have a silicone outer shell ...

  11. Domain walls and spacetime-filling branes

    NARCIS (Netherlands)

    Bergshoeff, E; Wess, J; Ivanov, EA

    1999-01-01

    We discuss branes with one transversal direction (domain walls) and no transversal direction (spacetime-filling branes). In particular, we briefly discuss a relationship between spacetime-filling branes and superstring theories with sixteen supercharges.

  12. Filling of carbon nanotubes and nanofibres

    Directory of Open Access Journals (Sweden)

    Reece D. Gately

    2015-02-01

    Full Text Available The reliable production of carbon nanotubes and nanofibres is a relatively new development, and due to their unique structure, there has been much interest in filling their hollow interiors. In this review, we provide an overview of the most common approaches for filling these carbon nanostructures. We highlight that filled carbon nanostructures are an emerging material for biomedical applications.

  13. Molecular modeling of polymer composite interactions with analytes in electronic nose sensors for environmental monitoring in International Space Station

    Science.gov (United States)

    Shevade, A. V.; Ryan, M. A.; Homer, M. L.; Manfreda, A. M.; Zhou, H.; Manatt, K.

    2002-01-01

    We report a molecular modeling study to investigate the polymer-carbon black (CB) composite-analyte interactions in resistive sensors. These sensors comprise the JPL Electronic Nose (ENose) sensing array developed for monitoring breathing air in human habitats. The polymer in the composite is modeled based on its stereisomerism and sequence isomerism, while the CB is modeled as uncharged naphthalene rings (with no hydrogens). The Dreiding 2.21 force field is used for the polymer and solvent molecules and graphite parameters are assigned to the carbon black atoms. A combination of molecular mechanics (MM) and molecular dynamics (NPT-MD and NVT-MD) techniques are used to obtain the equilibrium composite structure by inserting naphthalene rings in the polymer matrix. Polymers considered for this work include poly(4- vinylphenol), polyethylene oxide, and ethyl cellulose. Analytes studied are representative of both inorganic (ammonia) and organic (methanol, toluene, hydrazine) compounds. The results are analyzed for the composite microstructure by calculating the radial distribution profiles as well as for the sensor response by predicting the interaction energies of the analytes with the composites.

  14. Recent developments in inorganically filled carbon nanotubes: successes and challenges.

    Science.gov (United States)

    Gautam, Ujjal K; Costa, Pedro M F J; Bando, Yoshio; Fang, Xiaosheng; Li, Liang; Imura, Masataka; Golberg, Dmitri

    2010-10-01

    Carbon nanotubes (CNTs) are a unique class of nanomaterials that can be imagined as rolled graphene sheets. The inner hollow of a CNT provides an extremely small, one-dimensional space for storage of materials. In the last decade, enormous effort has been spent to produce filled CNTs that combine the properties of both the host CNT and the guest filling material. CNTs filled with various inorganic materials such as metals, alloys, semiconductors and insulators have been obtained using different synthesis approaches including capillary filling and chemical vapor deposition. Recently, several potential applications have emerged for these materials, such as the measurement of temperature at the nanoscale, nano-spot welding, and the storage and delivery of extremely small quantities of materials. A clear distinction between this class of materials and other nanostructures is the existence of an enormous interfacial area between the CNT and the filling matter. Theoretical investigations have shown that the lattice mismatch and strong exchange interaction of CNTs with the guest material across the interface should result in reordering of the guest crystal structure and passivation of the surface dangling bonds and thus yielding new and interesting physical properties. Despite preliminary successes, there remain many challenges in realizing applications of CNTs filled with inorganic materials, such as a comprehensive understanding of their growth and physical properties and control of their structural parameters. In this article, we overview research on filled CNT nanomaterials with special emphasis on recent progress and key achievements. We also discuss the future scope and the key challenges emerging out of a decade of intensive research on these fascinating materials.

  15. Recent developments in inorganically filled carbon nanotubes: successes and challenges

    Directory of Open Access Journals (Sweden)

    Ujjal K Gautam, Pedro M F J Costa, Yoshio Bando, Xiaosheng Fang, Liang Li, Masataka Imura and Dmitri Golberg

    2010-01-01

    Full Text Available Carbon nanotubes (CNTs are a unique class of nanomaterials that can be imagined as rolled graphene sheets. The inner hollow of a CNT provides an extremely small, one-dimensional space for storage of materials. In the last decade, enormous effort has been spent to produce filled CNTs that combine the properties of both the host CNT and the guest filling material. CNTs filled with various inorganic materials such as metals, alloys, semiconductors and insulators have been obtained using different synthesis approaches including capillary filling and chemical vapor deposition. Recently, several potential applications have emerged for these materials, such as the measurement of temperature at the nanoscale, nano-spot welding, and the storage and delivery of extremely small quantities of materials. A clear distinction between this class of materials and other nanostructures is the existence of an enormous interfacial area between the CNT and the filling matter. Theoretical investigations have shown that the lattice mismatch and strong exchange interaction of CNTs with the guest material across the interface should result in reordering of the guest crystal structure and passivation of the surface dangling bonds and thus yielding new and interesting physical properties. Despite preliminary successes, there remain many challenges in realizing applications of CNTs filled with inorganic materials, such as a comprehensive understanding of their growth and physical properties and control of their structural parameters. In this article, we overview research on filled CNT nanomaterials with special emphasis on recent progress and key achievements. We also discuss the future scope and the key challenges emerging out of a decade of intensive research on these fascinating materials.

  16. FLUXNET Marconi Conference Gap-Filled Flux and Meteorology Data, 1992-2000

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set, FLUXNET Marconi Conference Gap-Filled Flux and Meteorology Data, 1992-2000, was conceptualized at the FLUXNET 2000 Synthesis Workshop held at the...

  17. Lightweight Hybrid Ablator Incorporating Aerogel-Filled Open-Cell Foam Structural Insulator, Phase II Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In previous work for NASA and DoD, Ultramet developed lightweight open-cell foam insulators composed of a carbon or ceramic structural foam skeleton filled with a...

  18. Lightweight Hybrid Ablator Incorporating Aerogel-Filled Open-Cell Foam Structural Insulator Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In previous work for NASA and DoD, Ultramet developed lightweight open-cell foam insulators composed of a carbon or ceramic structural foam skeleton filled with a...

  19. Visualizing Proportions and Dissimilarities by Space-filling Maps

    DEFF Research Database (Denmark)

    Carrizosa, Emilio; Guerrero, Vanesa; Morales, Dolores Romero

    2017-01-01

    In this paper we address the problem of visualizing a set of individuals, which have attached a statistical value given as a proportion, and a dissimilarity measure. Each individual is represented as a region within the unit square, in such a way that the area of the regions represent the proport...

  20. Flexible Space-Filling Designs for Complex System Simulations

    Science.gov (United States)

    2013-06-01

    known as “model bias.” We desire designs less susceptible to model bias and with the ability to detect it when it occurs. Thus, we prefer designs that...changepoint. To increase the odds of detecting localized effects, we favor designs that sample throughout the experimental region. Such designs are called...variables (Hernandez, 2008). Although this criterion is somewhat arbitrary, designs meeting it suffer minimal adverse multicollinearity effects

  1. Filling the void - enriching the feature space of successful stopping

    NARCIS (Netherlands)

    Huster, René J.; Schneider, Signe; Lavallee, Christina F.; Enriquez-Geppert, Stefanie; Herrmann, Christoph S.

    2017-01-01

    The ability to inhibit behavior is crucial for adaptation in a fast changing environment and is commonly studied with the stop signal task. Current EEG research mainly focuses on the N200 and P300 ERPs and corresponding activity in the theta and delta frequency range, thereby leaving us with a

  2. Surface Patterning Using Diazonium Ink Filled Nanopipette.

    Science.gov (United States)

    Zhou, Min; Yu, Yun; Blanchard, Pierre-Yves; Mirkin, Michael V

    2015-11-03

    Molecular grafting of diazonium is a widely employed surface modification technique. Local electrografting of this species is a promising approach to surface doping and related properties tailoring. The instability of diazonium cation complicates this process, so that this species was generated in situ in many reported studies. In this Article, we report the egress transfer of aryl diazonium cation across the liquid/liquid interface supported at the nanopipette tip that can be used for controlled delivery this species to the external aqueous phase for local substrate patterning. An aryl diazonium salt was prepared with weakly coordinating and lipophilic tetrakis(pentafluorophenyl)borate anion stable as a solid and soluble in low polarity media. The chemically stable solution of this salt in 1,2-dichloroethane can be used as "diazonium ink". The ink-filled nanopipette was employed as a tip in the scanning electrochemical microscope (SECM) for surface patterning with the spatial resolution controlled by the pipette orifice radius and a few nanometers film thickness. The submicrometer-size grafted spots produced on the HOPG surface were located and imaged with the atomic force microscope (AFM).

  3. High Growth Rate Metal-Organic Molecular Beam Epitaxy for the Fabrication of GaAs Space Solar Cells

    Science.gov (United States)

    Freundlich, A.; Newman, F.; Monier, C.; Street, S.; Dargan, P.; Levy, M.

    2005-01-01

    In this work it is shown that high quality GaAs photovoltaic devices can be produced by Molecular Beam Epitaxy (MBE) with growth rates comparable to metal-organic chemical vapor deposition (MOCVD) through the subsitution of group III solid sources by metal-organic compounds. The influence the III/V flux-ratio and growth temperatures in maintaining a two dimensional layer by layer growth mode and achieving high growth rates with low residual background impurities is investigated. Finally subsequent to the study of the optimization of n- and p doping of such high growth rate epilayers, results from a preliminary attempt in the fabrication of GaAs photovoltaic devices such as tunnel diodes and solar cells using the proposed high growth rate approach are reported.

  4. A hybrid molecular dynamics/fluctuating hydrodynamics method for modelling liquids at multiple scales in space and time

    Energy Technology Data Exchange (ETDEWEB)

    Korotkin, Ivan, E-mail: i.korotkin@qmul.ac.uk; Karabasov, Sergey; Markesteijn, Anton [The School of Engineering and Material Science, Queen Mary University of London, Mile End Road, E1 4NS London (United Kingdom); Nerukh, Dmitry; Scukins, Arturs [Institute of Systems Analytics, Aston University, Birmingham B4 7ET (United Kingdom); Farafonov, Vladimir [Department of Physical Chemistry, V. N. Karazin Kharkiv National University, Svobody Square 4, 61022 Kharkiv (Ukraine); Pavlov, Evgen [Institute of Systems Analytics, Aston University, Birmingham B4 7ET (United Kingdom); Faculty of Physics, Kiev National Taras Shevchenko University, Prospect Acad. Glushkova 4, Kiev 03127 (Ukraine)

    2015-07-07

    A new 3D implementation of a hybrid model based on the analogy with two-phase hydrodynamics has been developed for the simulation of liquids at microscale. The idea of the method is to smoothly combine the atomistic description in the molecular dynamics zone with the Landau-Lifshitz fluctuating hydrodynamics representation in the rest of the system in the framework of macroscopic conservation laws through the use of a single “zoom-in” user-defined function s that has the meaning of a partial concentration in the two-phase analogy model. In comparison with our previous works, the implementation has been extended to full 3D simulations for a range of atomistic models in GROMACS from argon to water in equilibrium conditions with a constant or a spatially variable function s. Preliminary results of simulating the diffusion of a small peptide in water are also reported.

  5. Real-space imaging of molecular structure and chemical bonding by single-molecule inelastic tunneling probe.

    Science.gov (United States)

    Chiang, Chi-lun; Xu, Chen; Han, Zhumin; Ho, W

    2014-05-23

    The arrangement of atoms and bonds in a molecule influences its physical and chemical properties. The scanning tunneling microscope can provide electronic and vibrational signatures of single molecules. However, these signatures do not relate simply to the molecular structure and bonding. We constructed an inelastic tunneling probe based on the scanning tunneling microscope to sense the local potential energy landscape of an adsorbed molecule with a carbon monoxide (CO)-terminated tip. The skeletal structure and bonding of the molecule are revealed from imaging the spatial variations of a CO vibration as the CO-terminated tip probes the core of the interactions between adjacent atoms. An application of the inelastic tunneling probe reveals the sharing of hydrogen atoms among multiple centers in intramolecular and extramolecular bonding. Copyright © 2014, American Association for the Advancement of Science.

  6. Dedicated composite fillings − inlays

    Directory of Open Access Journals (Sweden)

    Šaulić Slobodan

    2003-01-01

    Full Text Available Background. The aim of the study was to evaluate the quality and persistance of esthetics of dedicated inlay by clinical methods. Methods. The paper reviews the clinical significance and technique of preparing particular composite inlays before and after the construction of the metallic framework partial denture. On the basis of indications the total of 30 inlays were placed into cavities under relatively dry working conditions. Six, twelve eighteen and twenty-four months after the placement of filling, control check-up was carried out by Ryge criteria. Results. After two years marginal discoloration as well as the change of the colour occured in 3.3% of inlays. There was neither detectable secondary caries, nor the symtoms of pulpal damage. The requirements to be fulfilled concerning the composite materials in order that they can be implemented for this purpose, were also discussed. Conclusion. From the clinical point of view, purpouse inlays from Herculite XRV lab C8B in combination with Opti Bond System and composite cement Porcelite Dual Cure showed high functional and esthetic values in the observational period of two years.

  7. Explicit Hilbert-space representations of atomic and molecular photoabsorption spectra - Computational studies of Stieltjes-Tchebycheff functions

    Science.gov (United States)

    Hermann, M. R.; Langhoff, P. W.

    1983-01-01

    Computational methods are reported for construction of discrete and continuum Schroedinger states in atoms and molecules employing explicit Hilbert space procedures familiar from bound state studies. As theoretical development, the Schroedinger problem of interest is described, the Cauchy-Lanczos bases and orthonormal polynomials used in constructing L-squared Stieltjes-Tchebycheff (ST) approximations to the discrete and continuum states are defined, and certain properties of these functions are indicated. Advantages and limitations of the ST approach to spectral studies relative to more conventional calculations are discussed, and aspects of the approach in single-channel approximations to larger molecules are described. Procedures are indicated for construction of photoejection anisotropies and for performing coupled-channel calculations employing the ST formalism. Finally, explicit descriptive intercomparisons are made of the nature and diagnostic value of ST functions with more conventional scattering functions.

  8. SIMULATION FROM ENDPOINT-CONDITIONED, CONTINUOUS-TIME MARKOV CHAINS ON A FINITE STATE SPACE, WITH APPLICATIONS TO MOLECULAR EVOLUTION.

    Science.gov (United States)

    Hobolth, Asger; Stone, Eric A

    2009-09-01

    Analyses of serially-sampled data often begin with the assumption that the observations represent discrete samples from a latent continuous-time stochastic process. The continuous-time Markov chain (CTMC) is one such generative model whose popularity extends to a variety of disciplines ranging from computational finance to human genetics and genomics. A common theme among these diverse applications is the need to simulate sample paths of a CTMC conditional on realized data that is discretely observed. Here we present a general solution to this sampling problem when the CTMC is defined on a discrete and finite state space. Specifically, we consider the generation of sample paths, including intermediate states and times of transition, from a CTMC whose beginning and ending states are known across a time interval of length T. We first unify the literature through a discussion of the three predominant approaches: (1) modified rejection sampling, (2) direct sampling, and (3) uniformization. We then give analytical results for the complexity and efficiency of each method in terms of the instantaneous transition rate matrix Q of the CTMC, its beginning and ending states, and the length of sampling time T. In doing so, we show that no method dominates the others across all model specifications, and we give explicit proof of which method prevails for any given Q, T, and endpoints. Finally, we introduce and compare three applications of CTMCs to demonstrate the pitfalls of choosing an inefficient sampler.

  9. Molecular Switching in Confined Spaces: Effects of Encapsulating the DHA/VHF Photo-Switch in Cucurbiturils.

    Science.gov (United States)

    Petersen, Michael Å; Rasmussen, Brian; Andersen, Nicolaj N; Sauer, Stephan P A; Nielsen, Mogens Brøndsted; Beeren, Sophie R; Pittelkow, Michael

    2017-09-18

    Confinement of reactive chemical species uniquely affects chemical reactivity by restricting the physical space available and by restricting access to interactions with the solvent. In Nature, for example, confined protein binding pockets govern processes following photoisomerization reactions and the isomerizations themselves. Here we describe the first example of a dihydroazulene/vinylheptafulvene (DHA/VHF) photo-switch functioning in water, and we show how its switching behavior is strongly influenced by supramolecular interactions with a series of cucurbit[n]uril (CB) host molecules. In CB7 inclusion complexes, the kinetics of the thermal VHF-to-DHA back-reaction is accelerated, while in CB8 inclusion complexes, the kinetics is slowed down as compared to the free photo-switch. The effect of the CB encapsulation of the photo-switch can be effectively canceled by introducing a guest that binds the CB more strongly. According to DFT calculations, a stabilization of the reactive s-cis VHF conformer relative to the s-trans VHF appears to be a contributing factor responsible for the accelerated back-reaction when encapsulated in CB7. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Concomitant polymorphism of a pyridine-2,6-dicarboxamide derivative in a single space group: Experimental and molecular modeling study

    Science.gov (United States)

    Özdemir, Namık; Dayan, Osman; Çetinkaya, Bekir; Akgül, Cahit

    2012-02-01

    The title compound, N2, N6-bis{2-[( Z)-2-hydroxybenzylideneamino]phenyl}pyridine-2,6-dicarboxamide ( 3), has been synthesized by the reaction of 2-{(2-aminophenylimino)methyl}phenol ( 1) with pyridine-2,6-dicarbonyl dichloride ( 2), and characterized by elemental analysis, FT-IR and NMR spectroscopies and thermal analysis. Compounds 1 and 3 were evaluated for their antibacterial activities against Gram-positive and Gram-negative bacteria. The catalytic activity of 3 was also studied, and as a result, the in situ prepared three component system Ru(II)/ 3/KOH is shown to be an efficient catalyst for the transfer hydrogenation reaction of various ketones under mild conditions. Compound 3 has been crystallized in two polymorphic forms under the same conditions, and their crystal structures have been determined using single crystal X-ray diffraction technique. The molecular geometry, vibrational frequencies and gauge-independent atomic orbital (GIAO) 1H and 13C NMR chemical shift values of 3 in the ground state have been calculated using the density functional theory (DFT/B3LYP) method with the 6-31G(d) basis set, and compared with the experimental data. The results are in good agreement with experimental data. The effect of different solvents on the geometry, vibrational frequencies, total energies and dipole moments was also studied using the same method by applying the Onsager Model. There are subtle differences in the conformations and packing of the two polymorphs as a consequence of intermolecular hydrogen bonding interactions. Therefore, DFT calculations for the hydrogen bond interactions in the polymorphs were carried out using same basis set. The changes of thermodynamic properties from the monomers to 3 with the temperature ranging from 200 K to 400 K have been obtained using the statistical thermodynamic method.

  11. ECO fill: automated fill modification to support late-stage design changes

    Science.gov (United States)

    Davis, Greg; Wilson, Jeff; Yu, J. J.; Chiu, Anderson; Chuang, Yao-Jen; Yang, Ricky

    2014-03-01

    One of the most critical factors in achieving a positive return for a design is ensuring the design not only meets performance specifications, but also produces sufficient yield to meet the market demand. The goal of design for manufacturability (DFM) technology is to enable designers to address manufacturing requirements during the design process. While new cell-based, DP-aware, and net-aware fill technologies have emerged to provide the designer with automated fill engines that support these new fill requirements, design changes that arrive late in the tapeout process (as engineering change orders, or ECOs) can have a disproportionate effect on tapeout schedules, due to the complexity of replacing fill. If not handled effectively, the impacts on file size, run time, and timing closure can significantly extend the tapeout process. In this paper, the authors examine changes to design flow methodology, supported by new fill technology, that enable efficient, fast, and accurate adjustments to metal fill late in the design process. We present an ECO fill methodology coupled with the support of advanced fill tools that can quickly locate the portion of the design affected by the change, remove and replace only the fill in that area, while maintaining the fill hierarchy. This new fill approach effectively reduces run time, contains fill file size, minimizes timing impact, and minimizes mask costs due to ECO-driven fill changes, all of which are critical factors to ensuring time-to-market schedules are maintained.

  12. Selective filling of Photonic Crystal Fibres

    DEFF Research Database (Denmark)

    Nielsen, Kristian; Noordegraaf, Danny; Sørensen, Thorkild

    2005-01-01

    A model for calculating the time necessary for filling one or more specific holes in a photonic crystal fibre is made. This model is verified for water, and its enabling potential is illustrated by a polymer application. Selective filling of the core in an air-guide photonic crystal fibre is demo...

  13. Scaffold Filling under the Breakpoint Distance

    Science.gov (United States)

    Jiang, Haitao; Zheng, Chunfang; Sankoff, David; Zhu, Binhai

    Motivated by the trend of genome sequencing without completing the sequence of the whole genomes, Muñoz et al. recently studied the problem of filling an incomplete multichromosomal genome (or scaffold) I with respect to a complete target genome G such that the resulting genomic distance between I' and G is minimized, where I' is the corresponding filled scaffold. We call this problem the one-sided scaffold filling problem. In this paper, we follow Muñoz et al. to investigate the scaffold filling problem under the breakpoint distance for the simplest unichromosomal genomes. When the input genome contains no gene repetition (i.e., is a fragment of a permutation), we show that the two-sided scaffold filling problem is polynomially solvable. However, when the input genome contains some genes which appear twice, even the one-sided scaffold filling problem becomes NP-complete. Finally, using the ideas for solving the two-sided scaffold filling problem under the breakpoint distance we show that the two-sided scaffold filling problem under the genomic/rearrangement distance is also polynomially solvable.

  14. Influence of template fill in graphoepitaxy DSA

    Science.gov (United States)

    Doise, Jan; Bekaert, Joost; Chan, Boon Teik; Hong, SungEun; Lin, Guanyang; Gronheid, Roel

    2016-03-01

    Directed self-assembly (DSA) of block copolymers (BCP) is considered a promising patterning approach for the 7 nm node and beyond. Specifically, a grapho-epitaxy process using a cylindrical phase BCP may offer an efficient solution for patterning randomly distributed contact holes with sub-resolution pitches, such as found in via and cut mask levels. In any grapho-epitaxy process, the pattern density impacts the template fill (local BCP thickness inside the template) and may cause defects due to respectively over- or underfilling of the template. In order to tackle this issue thoroughly, the parameters that determine template fill and the influence of template fill on the resulting pattern should be investigated. In this work, using three process flow variations (with different template surface energy), template fill is experimentally characterized as a function of pattern density and film thickness. The impact of these parameters on template fill is highly dependent on the process flow, and thus pre-pattern surface energy. Template fill has a considerable effect on the pattern transfer of the DSA contact holes into the underlying layer. Higher fill levels give rise to smaller contact holes and worse critical dimension uniformity. These results are important towards DSA-aware design and show that fill is a crucial parameter in grapho-epitaxy DSA.

  15. Looking for prebiotic species in space: a theoretical study of molecular structures of interest for the origin of life

    Science.gov (United States)

    Ellinger, Y.; Berthier, G.; Lattelais, M.; Chiaramello, Jm.

    The simplest possible species containing the peptide bond, NH2-CH=O, was identified in space more than thirty years ago (Rubin et al. (1971)). About the same time, a precursor of the peptide bond, HNCO, was also identified (Snyder et al. (1972)) and later confirmed (Brown (1981)) in the interstellar medium (ISM). The same molecule has been recently observed in the comets Hyakutake (Lis et al. (1997)) and Hale-Bopp (Lis et al. (1998)). More elaborate material, including the 20 aminoacids present in living organisms (Cooper et al. (1992)), has only been found associated with solids, namely in the meteorites collected on Earth, not in the ISM. Before designing complex chemical models for astrobiology, we considered the two following questions: i) what is the relative stability of the peptide bond compared to other types of bonds? ii) what is the relative stability of aminoacids compared to other possible isomers? In order to be able to perform calculations at the same level of theory for all compounds, whatever the size, we employed a unique approach based on the B3LYP formulation of density functional theory (DFT). Vibrational frequencies have been calculated for asserting the nature of the stationary points and evaluation of zero-point energy corrections. A systematic investigation of the structure and relative stability of all the isomers that may possibly form in the six atom system [C,3H,N,O] has been carried out. The most stable compound is formamide, NH2-CH=O, i.e. the one with the peptide bond. The same study was done for the systems where one of the heavy atoms C, N or O is replaced by its second row analogue. From this comprehensive study it can be concluded that the species containing the peptide type of linkage are the most stable, namely: NH2-SiH=O and NH2-CH=S. The exception is CH3-P=O that is more stable than PH2-CH=O. The same type of study has been performed on glycine, that is the simplest α amino acid that has been identified in chondrites of the

  16. 30 CFR 817.72 - Disposal of excess spoil: Valley fill/head-of-hollow fills.

    Science.gov (United States)

    2010-07-01

    ... functioning of the rock core shall be designed and constructed using current, prudent engineering practices...-hollow fills. 817.72 Section 817.72 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND... STANDARDS-UNDERGROUND MINING ACTIVITIES § 817.72 Disposal of excess spoil: Valley fill/head-of-hollow fills...

  17. New genome sequence data and molecular tools promote the use of photosynthetic and edible cyanobacteria in bioregenerative systems to support human space exploration.

    Science.gov (United States)

    Leys, Natalie; Morin, Nicolas; Janssen, Paul; Mergeay, Max

    Cyanobacteria are daily used as nutritional supplements (e.g. Spirulina) and are considered for promising applications beyond Earth, in space, where they can play a crucial role in closed miniaturised biological waste recycling systems that are currently developed to support future long-term space missions. Cyanobacteria can be cultured with artificial light in controllable photobioreactors, and used for the efficient removal of CO2 from and production of O2 in the at-mosphere of the confined spacecraft, for removal of nitrate from waste water that is recycled to potable water, and as complementary food source. In this context, the filamentous cyanobac-terium Arthrospira sp. PCC 8005 was selected as part of the bio-regenerative life-support system MELiSSA from the European Space Agency. For bioprocess control and optimisation, the access to its genetic information and the development of molecular tools is crucial. Here we report on our efforts to determine the full genome of the cyanobacterium Arthrospira sp. PCC 8005. The obtained sequence data were analysed in detail to gain a better insight in the photosynthetic, nutritive, or potential toxic potential of this strain. In addition, the sensitivity of PCC 8005 to ionizing radiation was investigated because prolonged exposure of PCC 8005 to cosmic radiation in space might have a deleterious effect on its metabolism and oxygenic properties. To our knowledge, of the 6 different research groups across the globe trying to sequence Arthrospira strains, none of them, including us, were yet able to obtain a complete genome sequence. For Arthrospira sp. strain PCC 8005, we obtained 119 contigs (assembled in 16 scaffolds), representing 6,3 Mb, with 5,856 predicted protein-coding sequences (CDSs) and 176 genes encoding RNA. The PCC 8005 genome displays an unusual high number of large repeated sequences, covering around 8% of the genome, which likely hampered the sequenc-ing. The PCC 8005 genome is also ridden by mobile

  18. MICROHARDNESS OF BULK-FILL COMPOSITE MATERIALS.

    Science.gov (United States)

    Kelić, Katarina; Matić, Sanja; Marović, Danijela; Klarić, Eva; Tarle, Zrinka

    2016-12-01

    The aim of the study was to determine microhardness of high- and low-viscosity bulk-fill composite resins and compare it with conventional composite materials. Four materials of high-viscosity were tested, including three bulk-fills: QuiXfi l (QF), x-tra fi l (XTF) and Tetric EvoCeram Bulk Fill (TEBCF), while nanohybrid composite GrandioSO (GSO) served as control. The other four were low-viscosity composites, three bulk-fill materials: Smart Dentin Replacement (SDR), Venus Bulk Fill (VBF) and x-tra base (XB), and conventional control material X-Flow (XF). Composite samples (n=5) were polymerized for 20 s with Bluephase G2 curing unit. Vickers hardness was used to determine microhardness of each material at the surface, and at 2-mm and 4-mm depth. GSO on average recorded significantly higher microhardness values than bulk-fill materials (pcomposite XF revealed similar microhardness values as SDR, but significantly lower than XB (pmaterials was lower than microhardness of the conventional composite material (GSO). Surface microhardness of low-viscosity materials was generally even lower. The microhardness of all tested materials at 4 mm was not different from their surface values. However, additional capping layer was a necessity for low-viscosity bulk-fill materials due to their low microhardness.

  19. Retrograde root filling with amalgam and Cavit.

    Science.gov (United States)

    Finne, K; Nord, P G; Persson, G; Lennartsson, B

    1977-04-01

    In a 3-year review of 218 teeth with retrograde root filling with amalgam orCavit, the results obtained with the former proved significantly better than those obtained with the latter. The difference seemed to be due to a better obliteration of the canal by amalgam. The obliterating effect of amalgam probably eliminates the need for revision of incomplete othograde root filling, for example, in cases with a post in the root canal. Irrespective of type of filling materials, the results were less good in cases with marginal bone loss.

  20. Spherical molecularly imprinted polymer particles : A promising tool for molecular recognition in capillary electrokinetic separations

    NARCIS (Netherlands)

    de Boer, T; Mol, R; de Zeeuw, RA; de Jong, GJ; Sherrington, DC; Cormack, PAG; Ensing, K

    Spherical molecularly imprinted polymer particles obtained via precipitation polymerization, were introduced as a pseudostationary phase in capillary electrophoresis (CE) to study molecular recognition. Analyses were performed via a partial filling technique using (+)-ephedrine-imprinted

  1. Influence of the length of remaining root canal filling and post space preparation on the coronal leakage of Enterococcus faecalis Influência do comprimento do material obturador remanescente no canal radicular e preparo do espaço protético na infiltração coronária do Enterococcus Faecalis

    Directory of Open Access Journals (Sweden)

    Alexandra Conca Alves Mozini

    2009-03-01

    Full Text Available This study evaluated the sealing ability of different lengths of remaining root canal filling and post space preparation against coronal leakage of Enterococcus faecalis. Forty-one roots of maxillary incisors were biomechanically prepared, maintaining standardized canal diameter at the middle and coronal thirds. The roots were autoclaved and all subsequent steps were undertaken in a laminar flow chamber. The canals of 33 roots were obturated with AH Plus sealer and gutta-percha. The root canal fillings were reduced to 3 predetermined lengths (n=11: G1=6 mm, G2=4 mm and G3=2 mm. The remaining roots served as positive and negative controls. Bacterial leakage test apparatuses were fabricated with the roots attached to Eppendorf tubes keeping 2 mm of apex submerged in BHI in glass flasks. The specimens received an E. faecalis inoculum of 1 x 107 cfu/mL every 3 days and were observed for bacterial leakage daily during 60 days. Data were submitted to ANOVA, Tukey's test and Fisher's test. At 60 days, G1 (6 mm and G2 (4 mm presented statistically similar results (p>0.05 (54.4% of specimens with bacterial leakage and both groups differed significantly (pEste estudo avaliou a capacidade de diferentes de remanescentes de material obturador do canal radicular e preparo do espaço protético na infiltração do Enterococcus faecalis. Quarenta e uma raízes de incisivos superiores foram preparadas biomecanicamente, mantendo-se diâmetro padronizado nos terços médio e cervical. As raízes foram autoclavadas e todos os passos subseqüentes foram realizados em capela de fluxo laminar. Os canais de 33 raízes foram obturadors com AH Plus e guta-percha. As obturações foram reduzidas a 3 comprimentos (n=11: G1=6 mm, G2=4 mm e G3=2 mm. As raízes remanescentes serviram de controles positivo e negativo. O dispositivo para testar a microinfiltração bacteriana foi confeccionado com as raízes fixas a Eppendorfs, mantendo-se 2 mm do ápice submergido em vidro

  2. Micro-CT analysis of filling ability and porosity of root-end filling materials

    Directory of Open Access Journals (Sweden)

    Mário TANOMARU-FILHO

    2017-12-01

    Full Text Available Abstract Introduction Filling ability of retrograde cavity and porosity are important properties for root-end filling materials and may be evaluated by using microcomputed tomography (micro-CT. Objective To evaluate filling ability and porosity of root-end filling materials using microcomputed tomography (micro-CT. Material and method Cavities with 1 mm internal diameter and 3 mm depth were prepared in bovine dentin sections by using ultrasonic tips (CVD No. 6.1107-6, and filled by Mineral Trioxide Aggregate (MTA; Sealer 26 (S26 and zinc oxide and eugenol cement (ZOE. Before and after filling, cavities were scanned by using micro-CT (SkyScan 1176. Filling and porosity were analyzed by using CTAn software. Filling ability was calculated based on volumetric percentage of the filled cavity. The number and percentage of closed pores were measured throughout entire extension of the filled cavity (total and in each third (cervical, middle and apical, by using bi and tridimensional analyses. The filling data were submitted to ANOVA and Tukey statistical tests, and porosity data to Kruskall-Wallis and Dunn tests, at a 5% significance level. Result S26 and ZOE presented higher filling ability than MTA (p<0.05. S26 showed the highest total porosity (number and percentage (p<0.05. In all thirds after 2D and 3D analyses, porosity was higher for S26 in comparison to MTA and ZOE (p<0.05. Conclusion Although Sealer 26 presented more porosity, the material was associated with a great filling ability. Micro-CT analysis showed no correlation between filling ability and porosity.

  3. Novel gap filling BARC with high chemical resistance

    Science.gov (United States)

    Ogata, Hiroto; Hashimoto, Yuto; Usui, Yuki; Tamura, Mamoru; Ohashi, Tomoya; Sakaida, Yasushi; Kishioka, Takahiro

    2017-03-01

    In the recent of the semiconductor manufacturing process, variety of properties (narrow gap-filling and planarity etc.) are required to organic BARC in addition to the conventional requirements. Moreover, SC-1 resistance is also needed because BARC is often used as a wet etching mask when TiN processing. But conventional BARC which include crosslinker doesn't have enough SC-1 resistance, and we found that it is also difficult to obtain good gap-filling and good planarity because of outgassing and film shrinkage derived from the crosslinker. In this study, we have developed the new self-crosslinking BARC. The new crosslinking system shows low outgassing and film shrinkage because of not including crosslinker. So, novel BARC has better gap filling property and planarity and over 3 times higher SC-1 resistance than that of conventional BARC. Moreover, by adding the low molecular weight additive which has high adhesive unit to TiN surface, the novel BARC has over 10 times higher SC-1 resistance than that of conventional BARC. And this novel BARC can be applied both ArF and KrF lithography process because of broad absorbance, high etching rate, chemical resistance (SC-1, SC-2, DHF, and others) and good film thickness uniformity. In this paper, we will discuss the detail of new self-crosslinking BARC in excellent total performance and our approach to achieve high chemical resistance.

  4. d-Amino acids in molecular evolution in space - Absolute asymmetric photolysis and synthesis of amino acids by circularly polarized light.

    Science.gov (United States)

    Sugahara, Haruna; Meinert, Cornelia; Nahon, Laurent; Jones, Nykola C; Hoffmann, Søren V; Hamase, Kenji; Takano, Yoshinori; Meierhenrich, Uwe J

    2018-01-31

    Living organisms on the Earth almost exclusively use l-amino acids for the molecular architecture of proteins. The biological occurrence of d-amino acids is rare, although their functions in various organisms are being gradually understood. A possible explanation for the origin of biomolecular homochirality is the delivery of enantioenriched molecules via extraterrestrial bodies, such as asteroids and comets on early Earth. For the asymmetric formation of amino acids and their precursor molecules in interstellar environments, the interaction with circularly polarized photons is considered to have played a potential role in causing chiral asymmetry. In this review, we summarize recent progress in the investigation of chirality transfer from chiral photons to amino acids involving the two major processes of asymmetric photolysis and asymmetric synthesis. We will discuss analytical data on cometary and meteoritic amino acids and their potential impact delivery to the early Earth. The ongoing and future ambitious space missions, Hayabusa2, OSIRIS-REx, ExoMars 2020, and MMX, are scheduled to provide new insights into the chirality of extraterrestrial organic molecules and their potential relation to the terrestrial homochirality. This article is part of a Special Issue entitled: d-Amino acids: biology in the mirror, edited by Dr. Loredano Pollegioni, Dr. Jean-Pierre Mothet and Dr. Molla Gianluca. Copyright © 2018 Elsevier B.V. All rights reserved.

  5. Gas-filled separators - An overview

    CERN Document Server

    Leino, M

    2003-01-01

    Gas-filled recoil separators have been used in nuclear physics studies since the early fifties. Most notably, they have found use in the separation of evaporation residues of heavy and very heavy elements from unwanted background. Gas-filled separators, alone or coupled to a detector array, offer an efficient, fast, compact and relatively inexpensive solution for nuclear structure studies. A new application is the use of a gas-filled device as a pre-separator in the study of chemical properties of the heaviest elements. Other uses include systematic study of fusion evaporation cross sections and accelerator mass spectrometry. In this contribution, an overview on gas-filled recoil separators, their characteristics, fields of application and possible future developments is given.

  6. A study of filling process for UV nanoimprint lithography using a fluid simulation

    Science.gov (United States)

    Yoneda, Ikuo; Nakagawa, Yasutada; Mikami, Shinji; Tokue, Hiroshi; Ota, Takumi; Koshiba, Takeshi; Ito, Masamitsu; Hashimoto, Koji; Nakasugi, Tetsuro; Higashiki, Tatsuhiko

    2009-03-01

    Nanoimprint lithography has advantages such as good resolution, CD uniformity and LER. However, nanoimprint lithography involves risks. In particular, defectivity is the most critical issue for nanoimprint lithography. Above all, the "non-fill defects" dominate such defects for UV nanoimprint. At the filling process of imprint resist, the capillary force that occurs between an imprint-resist and surface of template plays an important role. Our experience, suggests there is a relationship between the filling characteristics and pattern size of template. We also think the resist properties and the environmental conditions such as atmosphere pressure play important roles in the filling process. This paper explains the filling process dependency on the properties mentioned above. We analyzed the filling process using fluid simulation. At first, we assumed several pattern sizes with the same pattern height. Then, the filling times were estimated for each pattern size with various resist properties and the environmental conditions. An important attribute of our simulation model is the consideration accorded to the dissolution of gas between the template and imprint resist. As a result, the filling time of smaller pattern was found to be shorter than that of larger pattern. The assumed patterns are space and via on template ranging in size from 22nm width to 1000nm-width. The pattern height is 60nm. In this paper, we studied characteristics of filling mechanism by using fluid simulation. The relations between CD and filling time were obtained. We found that the gas dissolution rate is the dominant parameter for filling time.

  7. Dynamic characteristics of a partially fluid-filled cylindrical shell

    Energy Technology Data Exchange (ETDEWEB)

    Jhung, Myung Jo; Yu, Seon Oh [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of); Lim, Yeong Taek [Tae Sung S and E Inc., Seoul (Korea, Republic of)

    2011-03-15

    A pressurizer in a small integral type pressurized water reactor is located inside the upper region of the reactor vessel, and uses a space between the upper head of the reactor vessel and the upper region of the upper guide structure which is partially filled with fluid depending on the operating power. This new design requires a comprehensive investigation of vibration characteristics. This study investigates the modal characteristics of a pressurizer which uses a simplified cylindrical shell model, focusing on how having fluid in the shell affects vibration and response characteristics. In addition, an analysis of sloshing is performed and the response characteristics are addressed

  8. Finite element modelling of the mechanics of discrete carbon nanotubes filled with ZnS and comparison with experimental observations

    KAUST Repository

    Monteiro, André O.

    2013-09-25

    The mechanical response to a uniaxial compressive force of a single carbon nanotube (CNT) filled (or partially-filled) with ZnS has been modelled. A semi-empirical approach based on the finite element method was used whereby modelling outcomes were closely matched to experimental observations. This is the first example of the use of the continuum approach to model the mechanical behaviour of discrete filled CNTs. In contrast to more computationally demanding methods such as density functional theory or molecular dynamics, our approach provides a viable and expedite alternative to model the mechanics of filled multi-walled CNTs. © 2013 Springer Science+Business Media New York.

  9. Iron-Oxide-Filled Carbon Nanotubes

    Science.gov (United States)

    Cava, Carlos Eduardo

    Carbon nanotubes (CNT) are recognized as one of the most important materials in the recent history of nanotechnology. In the last 25 years, intensive studies about this material have led to new ideas for the use of nanomaterials in many technological products. The unique properties presented by this material allow its use in a wide range of applications. Known as a crystalline material, CNTs can, however, interact with many materials in different manners, making it easy to use as a composite. One interesting aspect is the possibility of filling the CNT hollow core with a foreign material, forming a filled CNT. This composite can be achieved in situ using chemical vapor deposition and arc-discharge or after the synthesis, by chemical methods. The technique choice to achieve the filled CNT depends on the material inside the CNT. The resulting material can provide new electrical, optical, and mechanical features due to the synergistic effect between the CNTs themselves and the filling, which can originate new multifunctional materials. Concerning the electrical conductivity and the gas sensing, the possible interaction between the CNT and the filling can modify the electronic structure of the material and, consequently, affect the kind of interaction between the CNT and different gases. Commonly, the filled CNTs are obtained with magnetic materials inside the tube, which are also precursors in their syntheses; this feature brings new possibilities to magnetic devices, such as memories. Among them, iron-oxide-filled carbon nanotubes have been suggested as a technological material for use in magnetic, electrical, and medical applications. Therefore, this kind of nanocomposite material can be useful in the preparation of versatile and durable solid-state sensors, memory devices, with simple manufacturing and in a proper size. In this chapter, an introduction about the production and application of iron-oxide-filled CNTs in its many different forms will be presented.

  10. Molecular Astrophysics from Space: the Physical and Chemical Effects of Star Formation and the Destruction of Planetary Systems around Evolved Stars

    Science.gov (United States)

    Neufeld, David

    2005-01-01

    The research conducted during the reporting period is grouped into three sections: 1) Warm molecular gas in the interstellar medium (ISM); 2) Absorption line studies of "cold" molecular clouds; 3) Vaporization of comets around the AGB star IRC+10216.

  11. Vented Chill / No-Vent Fill of Cryogenic Propellant Tanks

    Science.gov (United States)

    Rhys, Noah O.; Foster, Lee W.; Martin, Adam K.; Stephens, Jonathan R.

    2016-01-01

    Architectures for extended duration missions often include an on-orbit replenishment of the space vehicle's cryogenic liquid propellants. Such a replenishment could be accomplished via a tank-to-tank transfer from a dedicated tanker or a more permanent propellant depot storage tank. Minimizing the propellant loss associated with transfer line and receiver propellant tank thermal conditioning is essential for mass savings. A new methodology for conducting tank-to-tank transfer while minimizing such losses has been demonstrated. Charge-Hold-Vent is the traditional methodology for conducting a tank-to-tank propellant transfer. A small amount of cryogenic liquid is introduced to chill the transfer line and propellant tank. As the propellant absorbs heat and undergoes a phase change, the tank internal pressure increases. The tank is then vented to relieve pressure prior to another charge of cryogenic liquid being introduced. This cycle is repeated until the transfer lines and tank are sufficiently chilled and the replenishment of the propellant tank is complete. This method suffers inefficiencies due to multiple chill and vent cycles within the transfer lines and associated feed system components. Additionally, this system requires precise measuring of cryogenic fluid delivery for each transfer, multiple valve cycling events, and other complexities associated with cycled operations. To minimize propellant loss and greatly simplify on-orbit operations, an alternate methodology has been designed and demonstrated. The Vented Chill / No Vent Fill method is a simpler, constant flow approach in which the propellant tank and transfer lines are only chilled once. The receiver tank is continuously vented as cryogenic liquid chills the transfer lines, tank mass and ullage space. Once chilled sufficiently, the receiver tank valve is closed and the tank is completely filled. Interestingly, the vent valve can be closed prior to receiver tank components reaching liquid saturation

  12. Microsaccades counteract perceptual filling-in.

    Science.gov (United States)

    Troncoso, Xoana G; Macknik, Stephen L; Martinez-Conde, Susana

    2008-11-04

    Artificial scotomas positioned within peripheral dynamic noise fade perceptually during visual fixation (that is, the surrounding dynamic noise appears to fill-in the scotoma). Because the scotomas' edges are continuously refreshed by the dynamic noise background, this filling-in effect cannot be explained by low-level adaptation mechanisms (such as those that may underlie classical Troxler fading). We recently showed that microsaccades counteract Troxler fading and drive first-order visibility during fixation (S. Martinez-Conde, S. L. Macknik, X. G. Troncoso, & T. A. Dyar, 2006). Here we set out to determine whether microsaccades may counteract the perceptual filling-in of artificial scotomas and thus drive second-order visibility. If so, microsaccades may not only counteract low-level adaptation but also play a role in higher perceptual processes. We asked subjects to indicate, via button press/release, whether an artificial scotoma presented on a dynamic noise background was visible or invisible at any given time. The subjects' eye movements were simultaneously measured with a high precision video system. We found that increases in microsaccade production counteracted the perception of filling-in, driving the visibility of the artificial scotoma. Conversely, decreased microsaccades allowed perceptual filling-in to take place. Our results show that microsaccades do not solely overcome low-level adaptation mechanisms but they also contribute to maintaining second-order visibility during fixation.

  13. Filling boron nitride nanotubes with metals

    Science.gov (United States)

    Golberg, D.; Xu, F.-F.; Bando, Y.

    The authors' endeavors over the last few years with respect to boron nitride (BN) nanotube metal filling are reviewed. Mo clusters of 1-2 nm in size and FeNi Invar alloy (Fe 60 at.% Ni 40 at.%) or Co nanorods of 20-70 nm in diameter were embedded into BN nanotube channels via a newly developed two-stage process, in which multi-walled C nanotubes served as templates for the BN multi-walled nanotube synthesis. During cluster filling, low-surface-tension and melting-point Mo oxide first filled a C nanotube through the open tube ends, followed by fragmentation of this filling into discrete clusters via O2 outflow and C-->BN conversion within tubular shells at high temperature. During nanorod filling, C nanotubes containing FeNi or Co nanoparticles at the tube tips were first synthesized by plasma-assisted chemical vapor deposition on FeNi Invar alloy or Co substrates, respectively, and, then, the nanomaterial was heated to the melting points of the corresponding metals in a flow of B2O3 and N2 gases. During this second stage, simultaneous filling of nanotubes with a FeNi or Co melt through capillarity and chemical modification of C tubular shells to form BN nanotubes occurred. The synthesized nanocomposites were analyzed by scanning and high-resolution transmission electron microscopy, electron diffraction, electron-energy-loss spectroscopy and energy-dispersive X-ray spectroscopy. The nanostructures are presumed to function as `nanocables' having conducting metallic cores (FeNi, Co, Mo) and insulating nanotubular shields (BN) with the additional benefit of excellent environmental stability.

  14. Mechanical responses of filled thermoplastic elastomers

    Science.gov (United States)

    Wang, M.; Shan, D. C.; Liao, Y.

    2017-12-01

    In this paper, several mechanical responses of thermoplastic polyurethane (TPU) filled with nano-scale attapulgite (AT) particles, including cyclic loading-unloading behavior, dynamic mechanical behavior and stress relaxation have been investigated. With the addition of AT, it is noticed that the strength, modulus and stress relaxation time of TPU increased significantly compared to that of unfilled materials. It is also observed that, whether filled or unfilled TPU, pronounced inelastic mechanical features such as Mullins effect, residual strain and hysteresis, occurred mainly during the first load loop, but became more notable with AT increase.

  15. Investigation of Hardened Filling Grout Samples

    DEFF Research Database (Denmark)

    Sørensen, Eigil V.

     Suzlon Wind Energy A/S requested on August 28, 2007 an investigation of 2 samples of a hardened filling grout to be carried out, comprising drilling and strength determination of 4 test cylinders, and description of the surface characteristics of the samples....... Suzlon Wind Energy A/S requested on August 28, 2007 an investigation of 2 samples of a hardened filling grout to be carried out, comprising drilling and strength determination of 4 test cylinders, and description of the surface characteristics of the samples....

  16. Creep of granulated loose-fill insulation

    DEFF Research Database (Denmark)

    Rasmussen, Torben Valdbjørn

    This report presents a proposal for a standardised method for creep tests and the necessary theoretical framework that can be used to describe creep of a granulated loose-fill material. Furthermore results from a round robin test are shown. The round robin test was carried out in collaboration...... with SP-Building Physics in Sweden and VTT Building Technology in Finland. For the round robin test a cellulosic fibre insulation material was used. The proposed standardised method for creep tests and theories are limited to cases when the granulated loose-fill material is exposed to a constant...

  17. Alkaline earth filled nickel skutterudite antimonide thermoelectrics

    Science.gov (United States)

    Singh, David Joseph

    2013-07-16

    A thermoelectric material including a body centered cubic filled skutterudite having the formula A.sub.xFe.sub.yNi.sub.zSb.sub.12, where A is an alkaline earth element, x is no more than approximately 1.0, and the sum of y and z is approximately equal to 4.0. The alkaline earth element includes guest atoms selected from the group consisting of Be, Mb, Ca, Sr, Ba, Ra and combinations thereof. The filled skutterudite is shown to have properties suitable for a wide variety of thermoelectric applications.

  18. Filling defect artefacts in magnetic resonance urography

    Energy Technology Data Exchange (ETDEWEB)

    Girish, G.; Chooi, W.K.; Morcos, S.K. [Department of Diagnostic Imaging, Northern General Hospital, Sheffield Teaching Hospitals NHS Trust, S5 7AU, Sheffield (United Kingdom)

    2004-01-01

    The aim of this study was to determine the prevalence of filling defect artefacts (FDA) in magnetic resonance urography (MRU). Retrospectively, we assessed MRU examinations of 45 patients with neurogenic bladder dysfunction (21 men, 24 women; mean age 35 years, age range 18-71 years). The MRU was performed 30 min after intramuscular injection of 20 mg frusemide using heavily T2-weighted fast-spin-echo techniques [axial, thick coronal slab, coronal maximum intensity projection (MIP) images] with fat saturation. The images were reviewed by two observers to determine the presence of filling defects and dilatation of pelvicalyceal system and ureters. The filling defects were classified into central, eccentric and complete. Clinical course and plain films were reviewed to determine significance of the detected filling defects. True filling defects were observed in 5 patients (11%) and all due to stones seen on the plain radiograph of the abdomen. Filling defects artefacts (FDAs) were seen in 23 patients (51%; 17 pelvicalyceal system, 17 upper third of ureters, 7 mid ureters and 1 distal ureter). No stones were seen on the plain radiograph of these patients and they had a favourable clinical course for over 24 months. The true filling defects were large in size, eccentric in position and seen in more than one sequence of the MRU examination (axial, n=5; slab, n=5; and MIP, n=4). Four (80%) of the patients with true defects and 21 (91%) of those with FDAs had dilatation of the pelvicalyceal system and ureters. The FDAs were small in size, centrally placed (74%) and always seen in axial images, rarely in slab images (2 cases) and not seen in MIP images. Artefactual filling defects can be seen in MRU examinations. The cause of the FDAs is not fully explained and could be secondary to turbulent and fast flow of the urine. Some of the FDAs seen in the calyces could be due to the tips of the papillae. Awareness of such defects obviates misinterpretation and prevents

  19. Intermittent surface water connectivity: Fill and spill vs. fill and merge dynamics

    Science.gov (United States)

    Leibowitz, Scott G.; Mushet, David M.; Newton, Wesley E.

    2016-01-01

    Intermittent surface connectivity can influence aquatic systems, since chemical and biotic movements are often associated with water flow. Although often referred to as fill and spill, wetlands also fill and merge. We examined the effects of these connection types on water levels, ion concentrations, and biotic communities of eight prairie pothole wetlands between 1979 and 2015. Fill and spill caused pulsed surface water connections that were limited to periods following spring snow melt. In contrast, two wetlands connected through fill and merge experienced a nearly continuous, 20-year surface water connection and had completely coincident water levels. Fill and spill led to minimal convergence in dissolved ions and macroinvertebrate composition, while these constituents converged under fill and merge. The primary factor determining differences in response was duration of the surface water connection between wetland pairs. Our findings suggest that investigations into the effects of intermittent surface water connections should not consider these connections generically, but need to address the specific types of connections. In particular, fill and spill promotes external water exports while fill and merge favors internal storage. The behaviors of such intermittent connections will likely be accentuated under a future with more frequent and severe climate extremes.

  20. Intermittent Surface Water Connectivity: Fill and Spill Vs. Fill and Merge Dynamics.

    Science.gov (United States)

    Intermittent surface connectivity can influence aquatic systems, since chemical and biotic movements are often associated with water flow. Although often referred to as fill and spill, wetlands also fill and merge. We examined the effects of these connection types on water level...

  1. The structure of filled skutterudites and the local vibration behavior of the filling atom

    Science.gov (United States)

    Zhou, Xiaojuan; Zong, Peng-an; Chen, Xihong; Tao, Juzhou; Lin, He

    2017-02-01

    Both of atomic pair distribution function (PDF) and extended x-ray absorption fine structure (EXAFS) experiments have been carried out on unfilled and Yb-filled skutterudites YbxCo4Sb12 (x=0, 0.15, 0.2 and 0.25) samples. The structure refinements on PDF data confirm the large amplitude vibration of Yb atom and the dependence of Yb vibration amplitude on the filling content. Temperature dependent EXAFS experiment on filled skutterudites have been carried out at Yb LⅢ-edge in order to explore the local vibration behavior of filled atom. EXAFS experiments show that the Einstein temperature of the filled atom is very low (70.9 K) which agrees with the rattling behavior.

  2. The structure of filled skutterudites and the local vibration behavior of the filling atom

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Xiaojuan [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Dongguan Institute of Neutron Science, Dongguan 523808 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Zong, Peng-an [State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050 (China); Chen, Xihong [Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050 (China); Tao, Juzhou, E-mail: taoj@ihep.ac.cn [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Dongguan Institute of Neutron Science, Dongguan 523808 (China); Lin, He, E-mail: linhe@sinap.ac.cn [Shanghai Institute of Applied Physics, Chinese Academy of Science, Shanghai 201204 (China)

    2017-02-15

    Both of atomic pair distribution function (PDF) and extended x-ray absorption fine structure (EXAFS) experiments have been carried out on unfilled and Yb-filled skutterudites Yb{sub x}Co{sub 4}Sb{sub 12} (x=0, 0.15, 0.2 and 0.25) samples. The structure refinements on PDF data confirm the large amplitude vibration of Yb atom and the dependence of Yb vibration amplitude on the filling content. Temperature dependent EXAFS experiment on filled skutterudites have been carried out at Yb L{sub Ⅲ}-edge in order to explore the local vibration behavior of filled atom. EXAFS experiments show that the Einstein temperature of the filled atom is very low (70.9 K) which agrees with the rattling behavior.

  3. The Chemistry of Modern Dental Filling Materials.

    Science.gov (United States)

    Nicholson, John W.; Anstice, H. Mary

    1999-01-01

    Discusses materials used by dentists to restore teeth after decay has been removed. Shows how dental-material science is an interdisciplinary field in which chemistry plays a major part. Reviews the many developments polymer chemistry has contributed to the field of dental fillings. (CCM)

  4. Stability of fruit bases and chocolate fillings

    Directory of Open Access Journals (Sweden)

    Joice Natali Miquelim

    2011-03-01

    Full Text Available Syrups with high sugar content and dehydrated fruits in its composition can be added to chocolate fillings to reduce the need of artificial flavor and dyes attributing a natural appeal to the product. Fruit bases were produced with lyophilized strawberry, passion fruit, and sliced orange peel. Rheological dynamic oscillatory tests were applied to determine the products stability and tendency of shelf life. Values of G´ G´´ were found for orange flavor during the 90 days of storage. It was observed that shear stress values did not vary significantly suggesting product stability during the studied period. For all fillings, it was found a behavior similar to the fruit base indicating that it has great influence on the filling behavior and its stability. The use of a sugar matrix in fillings provided good shelf life for the fruit base, which could be kept under room temperature conditions for a period as long as one year. The good stability and storage conditions allow the use of fruit base for handmade products as well as for industrialized products.

  5. Form Filling with Self-Compacting Concrete

    DEFF Research Database (Denmark)

    Thrane, Lars Nyholm

    2002-01-01

    This paper describes a newly started Ph.D. project with the aim of simulating the form filling ability of Self-Compacting Concrete (SCC) taking into account the form geometry, reinforcement configuration, casting technique, and the rheological properties of the concrete. Comparative studies...

  6. Safety distances for hydrogen filling stations

    NARCIS (Netherlands)

    Matthijsen, A J C M; Kooi, E S

    2006-01-01

    In the context of spatial planning the Dutch Ministry of Housing, Spatial Planning and the Environment asked the Centre for External Safety of the National Institute for Public Health and the Environment (RIVM) to advice on safe distances pertaining to hydrogen filling stations. The RIVM made use of

  7. Root canal filling using Resilon: a review.

    LENUS (Irish Health Repository)

    Shanahan, D J

    2011-07-01

    Root canal treatment is achieved by chemo-mechanical debridement of the root canal system followed by filling. The filling material \\'entombs\\' residual bacteria and acts as a barrier which prevents the entrance of oral microorganisms and reinfection of the root canal system through microleakage. However, filling with contemporary root filling materials such as gutta-percha offers limited long-term resistance to microorganisms; as a result other materials such as Resilon have been investigated as alternatives. The aim of this review was to analyse the literature to consider whether Resilon is a suitable root canal filling material. A MEDLINE and Cochrane library search including various keyword searches identified several papers which investigated or discussed Resilon or RealSeal\\/Epiphany. Analysis of the literature demonstrated that the bulk of the literature is in vitro in nature, based largely on leakage-type studies, and demonstrates a wide variety of methodologies with conflicting findings; as a result meaningful conclusions are difficult. Within the limit of these in vitro studies Resilon appears to perform adequately in comparison to gutta-percha, however, as a result of the questionable merit of such studies, it cannot presently be considered an evidence-based alternative to the current gold standard gutta-percha. It is imperative that before Resilon is considered as a replacement material, a better understanding of the physical properties of the resin sealer and the reality of the adhesive \\'monoblock\\' are elucidated. The literature also demonstrates a paucity of quality long-term clinical outcome studies which will need to be addressed before firm conclusions can be reached.

  8. Efficiently gap-filling reaction networks.

    Science.gov (United States)

    Latendresse, Mario

    2014-06-28

    Flux Balance Analysis (FBA) is a genome-scale computational technique for modeling the steady-state fluxes of an organism's reaction network. When the organism's reaction network needs to be completed to obtain growth using FBA, without relying on the genome, the completion process is called reaction gap-filling. Currently, computational techniques used to gap-fill a reaction network compute the minimum set of reactions using Mixed-Integer Linear Programming (MILP). Depending on the number of candidate reactions used to complete the model, MILP can be computationally demanding. We present a computational technique, called FastGapFilling, that efficiently completes a reaction network by using only Linear Programming, not MILP. FastGapFilling creates a linear program with all candidate reactions, an objective function based on their weighted fluxes, and a variable weight on the biomass reaction: no integer variable is used. A binary search is performed by modifying the weight applied to the flux of the biomass reaction, and solving each corresponding linear program, to try reducing the number of candidate reactions to add to the network to generate a working model. We show that this method has proved effective on a series of incomplete E. coli and yeast models with, in some cases, a three orders of magnitude execution speedup compared with MILP. We have implemented FastGapFilling in MetaFlux as part of Pathway Tools (version 17.5), which is freely available to academic users, and for a fee to commercial users. Download from: biocyc.org/download.shtml. The computational technique presented is very efficient allowing interactive completion of reaction networks of FBA models. Computational techniques based on MILP cannot offer such fast and interactive completion.

  9. Structure of solvent-free grafted nanoparticles: Molecular dynamics and density-functional theory

    KAUST Repository

    Chremos, Alexandros

    2011-01-01

    The structure of solvent-free oligomer-grafted nanoparticles has been investigated using molecular dynamics simulations and density-functional theory. At low temperatures and moderate to high oligomer lengths, the qualitative features of the core particle pair probability, structure factor, and the oligomer brush configuration obtained from the simulations can be explained by a density-functional theory that incorporates the configurational entropy of the space-filling oligomers. In particular, the structure factor at small wave numbers attains a value much smaller than the corresponding hard-sphere suspension, the first peak of the pair distribution function is enhanced due to entropic attractions among the particles, and the oligomer brush expands with decreasing particle volume fraction to fill the interstitial space. At higher temperatures, the simulations reveal effects that differ from the theory and are likely caused by steric repulsions of the expanded corona chains. © 2011 American Institute of Physics.

  10. Electronic phase diagram in the half-filled ionic Hubbard model with site-dependent interactions

    Science.gov (United States)

    Hoang, Anh-Tuan; Nguyen, Thi-Hai-Yen; Le, Duc-Anh

    2018-02-01

    The ionic Hubbard model with spatially alternating interactions, which may be realized by cold atoms in optical lattices, is studied by mean of the coherent potential approximation. The paramagnetic phase diagram for the half-filled model at zero temperature is obtained. The possibility of enlarging an intermediate metallic region in the parameter space is addressed.

  11. A new discrete filled function algorithm for discrete global optimization

    Science.gov (United States)

    Yongjian, Yang; Yumei, Liang

    2007-05-01

    A definition of the discrete filled function is given in this paper. Based on the definition, a discrete filled function is proposed. Theoretical properties of the proposed discrete filled function are investigated, and an algorithm for discrete global optimization is developed from the new discrete filled function. The implementation of the algorithms on several test problems is reported with satisfactory numerical results.

  12. The order and volume fill rates in inventory control systems

    DEFF Research Database (Denmark)

    Thorstenson, Anders; Larsen, Christian

    2011-01-01

    This paper differentiates between an order (line) fill rate and a volume fill rate and specifies their performance for different inventory control systems. When the focus is on filling complete customer orders rather than total quantities the order fill rate would be the preferred service level...

  13. 27 CFR 4.72 - Metric standards of fill.

    Science.gov (United States)

    2010-04-01

    ... milliliters. 500 milliliters. (b) Sizes larger than 3 liters. Wine may be bottled or packed in containers of 4..., DEPARTMENT OF THE TREASURY LIQUORS LABELING AND ADVERTISING OF WINE Standards of Fill for Wine § 4.72 Metric standards of fill. (a) Authorized standards of fill. The standards of fill for wine are the following: 3...

  14. Radiation-induced mechanical property changes in filled rubber.

    Science.gov (United States)

    Maiti, A; Weisgraber, T H; Gee, R H; Small, W; Alviso, C T; Chinn, S C; Maxwell, R S

    2011-06-01

    In a recent paper we exposed a filled elastomer to controlled radiation dosages and explored changes in its cross-link density and molecular weight distribution between network junctions [A. Maiti et al., Phys. Rev. E 83, 031802 (2011)]. Here we report mechanical response measurements when the material is exposed to radiation while being under finite nonzero strain. We observe interesting hysteretic behavior and material softening representative of the Mullins effect, and materials hardening due to radiation. The net magnitude of the elastic modulus depends upon the radiation dosage, strain level, and strain-cycling history of the material. Using the framework of Tobolsky's two-stage independent network theory we develop a model that can quantitatively interpret the observed elastic modulus and its radiation and strain dependence.

  15. Root Canal Filling after Revascularization/Revitalization.

    Science.gov (United States)

    Plascencia, Hugo; Cruz, Álvaro; Díaz, Mariana; Jiménez, Ana Laura; Solís, Rodrigo; Bernal, Cesar

    Revascularization/revitalization therapy is considered an alternative procedure for management of teeth with an immature apex and necrotic pulp, mainly when root development is interrupted in the early phases of formation. However, this clinical treatment protocol should be considered a permanent procedure? A maxillary central incisor with a previous and successful RR treatment was intentionally filled with a biocompatible material with the periapical tissues due to the patient's lack of adherence to the follow-up protocol. The 20-month follow-up showed absence of clinical, radiological and tomographic signs and symptoms of an endodontic re-infection. This case demonstrates that once the increased thickening of the canal walls, incrementing the root length, apical closure and the total resolution of the apical lesion are observed, the main canal of a previously treated tooth with an RR procedure can be filled.

  16. Flammability of Gas-Filled Polymers

    Directory of Open Access Journals (Sweden)

    Ushkov Valentin Anatol'evich

    2017-09-01

    Full Text Available The regularities of flame propagation on the horizontal surface of gas-filled polymers are considered depending on the concentration of oxygen in the oxidizer flow. The values of the coefficients in the expression describing relationship between the rate of flame propagation on the surface of foams and oxygen concentration are obtained. It was shown that with the mass content of reactive organophosphorus compounds reaching 4.0...5.9%, non-smoldering resole foam plastics with high performance characteristics are obtained. It was found that in order to obtain moderately combustible polyurethane foams based on oxyethylated phosphorus-containing polyols, the phosphorus concentration should not exceed 3 % of mass. To obtain flame-retardant urea-formaldehyde foam cellular plastics, the concentration of phosphorus should not exceed 0.3 % of mass. Physical-mechanical properties and flammability indices of developed gas-filled polymers based on reactive oligomers are presented.

  17. Hydrodynamic pressure in liquid filled container

    Science.gov (United States)

    Maiti, Pabitra Ranjan

    2011-12-01

    Liquid storage tanks are used to store oil, drinking water and different liquids which are necessary in industry and energy production. Partially liquid filled container shows free surface movement under external excitation this phenomenon is known as sloshing of liquid. When external excitation frequency matches the natural frequency of sloshing, a violent oscillation may occur that causes excess dynamic pressure on the tank structure. The dynamic behavior of liquid storage tanks under seismic excitation has been the subject of numerous theoretical and experimental investigations. This paper presents a pressure based finite element analysis of the liquid-structure systems considering the coupled effect of elastic structure and liquid. The equation of motion of the liquid is considered as incompressible and inviscid. The hydrodynamic pressure variation along a wall of prismatic container is studied and presented for different fill depth of liquid under sinusoidal base excitation.

  18. The Berkeley gas-filled separator

    CERN Document Server

    Ninov, V; McGrath, C A

    1998-01-01

    The BGS is being constructed at the 88-Inch Cyclotron at LBNL in Berkeley. The magnetic configuration of the BGS will allow a large angular acceptance and good suppression of primary beam particles. BGS operates as a mass spectrometer with a A/ Delta A approximately =200 and as a gas filled separator at pressures between 0.1-50 hPa. The reaction products recoiling off a thin target will be collected with efficiencies from 10-80at the focal plane. A Monte Carlo simulation program of the ion transport through the gas-filled magnets in combination of 3-dimensional TOSCA field maps has been developed and reproduces closely the experimental behavior of BGS. (9 refs).

  19. Full-waveform inversion: Filling the gaps

    KAUST Repository

    Beydoun, Wafik B.

    2015-09-01

    After receiving an outstanding response to its inaugural workshop in 2013, SEG once again achieved great success with its 2015 SEG Middle East Workshop, “Full-waveform inversion: Filling the gaps,” which took place 30 March–1 April 2015 in Abu Dhabi, UAE. The workshop was organized by SEG, and its partner sponsors were Saudi Aramco (gold sponsor), ExxonMobil, and CGG. Read More: http://library.seg.org/doi/10.1190/tle34091106.1

  20. Air filled porosity in composting processes

    Energy Technology Data Exchange (ETDEWEB)

    Ruggieri, L.; Gea, T.; Artola, A.; Sanchez, A.

    2009-07-01

    As it is widely known, the composting process consists in the aerobic decomposition of the biodegradable organic matter present in different types of solid wastes. Water and oxygen are necessary for the biological activity of microorganisms involved in the composting process and their availability is directly related to the total and the air filled porosity (AFP). Maintaining adequate AFP level satisfies the oxygen content requirement to achieve the desired composting conditions and thus, tho enhance biological activity. (Author)

  1. Le déficit de filles

    International Development Research Centre (IDRC) Digital Library (Canada)

    situation qui aura de lourdes conséquences sociales. La tendance à maltraiter les filles existe dans toutes les régions, classes économiques et castes de l'Inde et découle d'un ensemble complexe de facteurs économiques, sociaux et culturels. Une approche novatrice de la recherche omme les études menées à ce jour sur ...

  2. Slotted Polyimide-Aerogel-Filled-Waveguide Arrays

    Science.gov (United States)

    Rodriguez-Solis, Rafael A.; Pacheco, Hector L.; Miranda, Felix A.; Meador, Mary Ann B.

    2013-01-01

    This presentation discussed the potential advantages of developing Slotted Waveguide Arrays using polyimide aerogels. Polyimide (PI) aerogels offer great promise as an enabling technology for lightweight aerospace antenna systems. PI aerogels are highly porous solids possessing low density and low dielectric permittivity combined with good mechanical properties. For slotted waveguide array applications, there are significant advantages in mass that more than compensate for the slightly higher loss of the aerogel filled waveguide when compared to state of practice commercial waveguide.

  3. Text-Filled Stacked Area Graphs

    DEFF Research Database (Denmark)

    Kraus, Martin

    2011-01-01

    Text can add a significant amount of detail and value to an information visualization. In particular, it can integrate more of the data that a visualization is based on, and it can also integrate information that is personally relevant to readers of a visualization. This may influence readers to ...... solutions for the design of text-filled stacked area graphs with the help of an exemplary visualization of the genres, publication years, and titles of a database of several thousand PC games....

  4. Mobile myelographic filling defects: Spinal cysticercosis

    Energy Technology Data Exchange (ETDEWEB)

    Savoiardo, M.; Cimino, C.; Passerini, A.; La Mantia, L.

    1986-03-01

    Cysticercosis usually affects the brain and is easily demonstrated by CT. Spinal cysticercosis is much rarer and is usually diagnosed only at surgery. Myelographic demonstration of multiple rounded filling defects, some of which were mobile, allowed diagnosis of spinal extramedullary cysticercosis in an unsuspected case. The literature on spinal cysticercosis is briefly reviewed. Diagnosis is important in view of the recent development of medical treatment.

  5. The Complexity of Flood Filling Games

    Science.gov (United States)

    Arthur, David; Clifford, Raphaël; Jalsenius, Markus; Montanaro, Ashley; Sach, Benjamin

    We study the complexity of the popular one player combinatorial game known as Flood-It. In this game the player is given an n ×n board of tiles, each of which is allocated one of c colours. The goal is to fill the whole board with the same colour via the shortest possible sequence of flood filling operations from the top left. We show that Flood-It is NP-hard for c ≥ 3, as is a variant where the player can flood fill from any position on the board. We present deterministic (c - 1) and randomised 2c/3 approximation algorithms and show that no polynomial time constant factor approximation algorithm exists unless P=NP. We then demonstrate that the number of moves required for the 'most difficult' boards grows like Θ(sqrt{c} n). Finally, we prove that for random boards with c ≥ 3, the number of moves required to flood the whole board is Ω(n) with high probability.

  6. Boron filled siloxane polymers for radiation shielding

    Science.gov (United States)

    Labouriau, Andrea; Robison, Tom; Shonrock, Clinton; Simmonds, Steve; Cox, Brad; Pacheco, Adam; Cady, Carl

    2018-03-01

    The purpose of the present work was to evaluate changes to structure-property relationships of 10B filled siloxane-based polymers when exposed to nuclear reactor radiation. Highly filled polysiloxanes were synthesized with the intent of fabricating materials that could shield high neutron fluences. The newly formulated materials consisted of cross-linked poly-diphenyl-methylsiloxane filled with natural boron and carbon nanofibers. This polymer was chosen because of its good thermal and chemical stabilities, as well as resistance to ionizing radiation thanks to the presence of aromatic groups in the siloxane backbone. Highly isotopically enriched 10B filler was used to provide an efficient neutron radiation shield, and carbon nanofibers were added to improve mechanical strength. This novel polymeric material was exposed in the Annular Core Research Reactor (ACRR) at Sandia National Labs to five different neutron/gamma fluxes consisting of very high neutron fluences within very short time periods. Thermocouples placed on the specimens recorded in-situ temperature changes during radiation exposure, which agreed well with those obtained from our MCNP simulations. Changes in the microstructural, thermal, chemical, and mechanical properties were evaluated by SEM, DSC, TGA, FT-IR NMR, solvent swelling, and uniaxial compressive load measurements. Our results demonstrate that these newly formulated materials are well-suitable to be used in applications that require exposure to different types of ionizing conditions that take place simultaneously.

  7. Optimal Electrostatic Space Tower (Mast, New Space Elevator)

    OpenAIRE

    Bolonkin, Alexander

    2007-01-01

    Author offers and researched the new and revolutionary inflatable electrostatic AB space towers (mast, new space elevator) up to one hundred twenty thousands kilometers (or more) in height. The main innovation is filling the tower by electron gas, which can create pressure up one atmosphere, has negligible small weight and surprising properties. The suggested mast has following advantages in comparison with conventional space elevator: 1. Electrostatic AB tower may be built from Earth surface...

  8. A Preliminary Evaluation of Using Fill Materials to Stabilize Used Nuclear Fuel During Storage and Transportation

    Energy Technology Data Exchange (ETDEWEB)

    Maheras, Steven J.; Best, Ralph; Ross, Steven B.; Lahti, Erik A.; Richmond, David J.

    2012-08-01

    This report contains a preliminary evaluation of potential fill materials that could be used to fill void spaces in and around used nuclear fuel contained in dry storage canisters in order to stabilize the geometry and mechanical structure of the used nuclear fuel during extended storage and transportation after extended storage. Previous work is summarized, conceptual descriptions of how canisters might be filled were developed, and requirements for potential fill materials were developed. Elements of the requirements included criticality avoidance, heat transfer or thermodynamic properties, homogeneity and rheological properties, retrievability, material availability and cost, weight and radiation shielding, and operational considerations. Potential fill materials were grouped into 5 categories and their properties, advantages, disadvantages, and requirements for future testing were discussed. The categories were molten materials, which included molten metals and paraffin; particulates and beads; resins; foams; and grout. Based on this analysis, further development of fill materials to stabilize used nuclear fuel during storage and transportation is not recommended unless options such as showing that the fuel remains intact or canning of used nuclear fuel do not prove to be feasible.

  9. Statistical evaluation of metal fill widths for emulated metal fill in parasitic extraction methodology

    Science.gov (United States)

    J-Me, Teh; Noh, Norlaili Mohd.; Aziz, Zalina Abdul

    2015-05-01

    In the chip industry today, the key goal of a chip development organization is to develop and market chips within a short time frame to gain foothold on market share. This paper proposes a design flow around the area of parasitic extraction to improve the design cycle time. The proposed design flow utilizes the usage of metal fill emulation as opposed to the current flow which performs metal fill insertion directly. By replacing metal fill structures with an emulation methodology in earlier iterations of the design flow, this is targeted to help reduce runtime in fill insertion stage. Statistical design of experiments methodology utilizing the randomized complete block design was used to select an appropriate emulated metal fill width to improve emulation accuracy. The experiment was conducted on test cases of different sizes, ranging from 1000 gates to 21000 gates. The metal width was varied from 1 x minimum metal width to 6 x minimum metal width. Two-way analysis of variance and Fisher's least significant difference test were used to analyze the interconnect net capacitance values of the different test cases. This paper presents the results of the statistical analysis for the 45 nm process technology. The recommended emulated metal fill width was found to be 4 x the minimum metal width.

  10. Simulating Smoke Filling in Big Halls by Computational Fluid Dynamics

    Directory of Open Access Journals (Sweden)

    W. K. Chow

    2011-01-01

    Full Text Available Many tall halls of big space volume were built and, to be built in many construction projects in the Far East, particularly Mainland China, Hong Kong, and Taiwan. Smoke is identified to be the key hazard to handle. Consequently, smoke exhaust systems are specified in the fire code in those areas. An update on applying Computational Fluid Dynamics (CFD in smoke exhaust design will be presented in this paper. Key points to note in CFD simulations on smoke filling due to a fire in a big hall will be discussed. Mathematical aspects concerning of discretization of partial differential equations and algorithms for solving the velocity-pressure linked equations are briefly outlined. Results predicted by CFD with different free boundary conditions are compared with those on room fire tests. Standards on grid size, relaxation factors, convergence criteria, and false diffusion should be set up for numerical experiments with CFD.

  11. The synthesis and filling of single-walled carbon nanotubes

    CERN Document Server

    Friedrichs, S

    2002-01-01

    This thesis is concerned with the synthesis, properties and application of single-walled carbon nanotubes (SWNTs). The two main objectives of the work were the development of a continuous-flow synthesis of SWNTs, using chemical vapour deposition (CVD) techniques, and the application of the hollow SWNTs as moulds for the study of the crystallisation behaviour of inorganic materials in the confined space of their inner cavity. The latter study was mainly performed by interpreting high-resolution transmission electron microscopy (HRTEM) images of the filled SWNTs. A so-called focal series restoration approach, which enhances the resolution of the images and thereby increases the information content, was employed where possible. Chapter I reviews the previous work in the field of SWNTs and introduces their basic structure, symmetry, physical and mechanical properties and the common methods of SWNT synthesis. The chapter ends with an overview of the techniques used in the present work for the characterisation of c...

  12. Buckling of ZnS-filled single-walled carbon nanotubes – The influence of aspect ratio

    KAUST Repository

    Monteiro, André O.

    2014-08-16

    The mechanical response of single-walled carbon nanotubes (SWCNT) filled with crystalline zinc sulphide (ZnS) nanowires under uniaxial compression is studied using classical molecular dynamics. These simulations were used to analyse the behaviour of SWCNT, with and without ZnS filling, in terms of critical force and critical strain. Force versus strain curves have been computed for hollow and filled systems, the latter clearly showing an improvement of the mechanical behaviour caused by the ZnS nanowire. The same simulations were repeated for a large range of dimensions in order to evaluate the influence of the aspect ratio on the mechanical response of the tubes.

  13. Electroviscous effects in capillary filling of nanochannels

    DEFF Research Database (Denmark)

    Mortensen, Asger; Kristensen, Anders

    2008-01-01

    a maximum in the mesoscopic regime where the channel height (or more generally the hydraulic radius) is comparable to the screening length. However, for realistic estimates of central parameters, we find that the electroviscous contribution to the apparent viscosity is at most a 1% effect.......We theoretically examine the widespread hypothesis of an electroviscous origin of the increase in apparent viscosity observed in recent experiments on capillary filling of nanochannels. Including Debye-layer corrections to the hydraulic resistance, we find that the apparent viscosity reaches...

  14. Hydraulic fracturing of rock-fill dam

    Directory of Open Access Journals (Sweden)

    Jun-Jie WANG

    2016-02-01

    Full Text Available The condition in which hydraulic fracturing in core of earth-rock fill dam maybe induced, the mechanism by which the reason of hydraulic fracturing canbe explained, and the failure criterion by which the occurrence of hydraulicfracturing can be determined, were investigated. The condition dependson material properties such as, cracks in the core and low permeability ofcore soil, and “water wedging” action in cracks. An unsaturated core soiland fast impounding are the prerequisites for the formation of “waterwedging” action. The mechanism of hydraulic fracturing can be explainedby fracture mechanics. The crack propagation induced by water pressuremay follow any of mode I, mode II and mixed mode I-II. Based on testingresults of a core soil, a new criterion for hydraulic fracturing was suggested,from which mechanisms of hydraulic fracturing in the core of rock-fill damwere discussed. The results indicated that factors such as angle betweencrack surface and direction of principal stress, local stress state at thecrack, and fracture toughness KIC of core soil may largely affect theinduction of hydraulic fracturing and the mode of the propagation of thecrack.The condition in which hydraulic fracturing in core of earth-rock fill dam maybe induced, the mechanism by which the reason of hydraulic fracturing canbe explained, and the failure criterion by which the occurrence of hydraulicfracturing can be determined, were investigated. The condition dependson material properties such as, cracks in the core and low permeability ofcore soil, and “water wedging” action in cracks. An unsaturated core soiland fast impounding are the prerequisites for the formation of “waterwedging” action. The mechanism of hydraulic fracturing can be explainedby fracture mechanics. The crack propagation induced by water pressuremay follow any of mode I, mode II and mixed mode I-II. Based on testingresults of a core soil, a new criterion for hydraulic fracturing

  15. Carbon Nanotubes Filled with Ferromagnetic Materials

    Science.gov (United States)

    Weissker, Uhland; Hampel, Silke; Leonhardt, Albrecht; Büchner, Bernd

    2010-01-01

    Carbon nanotubes (CNT) filled with ferromagnetic metals like iron, cobalt or nickel are new and very interesting nanostructured materials with a number of unique properties. In this paper we give an overview about different chemical vapor deposition (CVD) methods for their synthesis and discuss the influence of selected growth parameters. In addition we evaluate possible growth mechanisms involved in their formation. Moreover we show their identified structural and magnetic properties. On the basis of these properties we present different application possibilities. Some selected examples reveal the high potential of these materials in the field of medicine and nanotechnology. PMID:28883334

  16. Viscoelastic modeling of filled, crosslinked rubbers

    Science.gov (United States)

    Joshi, Prashant G.

    1999-10-01

    Filled polymer systems have been a subject of interest for rheologists since the past many decades. Their applications range from paints and pigments to high performance composite materials. Tires come under a special class of applications wherein the type of filler used, its reinforcing abilities, traction improvement capabilities and cost effectiveness enormously control the final end use. Presently, there is lack of a complete understanding of the behavior of these materials under different load conditions. Moreover there is a lack of a comprehensive theory which can describe the rheology of filled rubbers, their chemorheology, and their behavior in the final fully cured state simultaneously. The present work is aimed at capturing a wide range of rheological/viscoelastic properties of filled rubbers with one set of constitutive/kinetic equations and a flexible relaxation spectrum. Various mechanical properties of filled, crosslinked rubbers were investigated in order to understand their analogy in the melt state. For this purpose, quasi-static hysteresis and step-strain relaxation experiments were carried out. Dynamic mechanical properties were understood in great details by using Fourier harmonic analysis to understand the time and strain non-linearities in the material. The time non-linearities arise due to thixotropic and non-isothermal effects, while the waveform distortions (strain related) occur due to non-linear viscoelastic effects. It is also very important to ensure no interference from any extraneous noise in the system during a dynamic test. Using the experimental evidences in melt rheology (creeping flow, shear start-up, and relaxation), and the kinetic mechanisms that affect chemorheology [152], an appropriate thixotropic-viscoelastic spectrum was chosen in order to describe experiments in all states of SBR rubber satisfactorily. This approach convinces that various manifestations of the filler in the melt state are preserved during crosslinking

  17. Carbon Nanotubes Filled with Ferromagnetic Materials

    Directory of Open Access Journals (Sweden)

    Albrecht Leonhardt

    2010-08-01

    Full Text Available Carbon nanotubes (CNT filled with ferromagnetic metals like iron, cobalt or nickel are new and very interesting nanostructured materials with a number of unique properties. In this paper we give an overview about different chemical vapor deposition (CVD methods for their synthesis and discuss the influence of selected growth parameters. In addition we evaluate possible growth mechanisms involved in their formation. Moreover we show their identified structural and magnetic properties. On the basis of these properties we present different application possibilities. Some selected examples reveal the high potential of these materials in the field of medicine and nanotechnology.

  18. Filling behaviour of wood plastic composites

    Science.gov (United States)

    Duretek, I.; Lucyshyn, T.; Holzer, C.

    2017-01-01

    Wood plastic composites (WPC) are a young generation of composites with rapidly growing usage within the plastics industry. The advantages are the availability and low price of the wood particles, the possibility of partially substituting the polymer in the mixture and sustainable use of the earth’s resources. The current WPC products on the market are to a large extent limited to extruded products. Nowadays there is a great interest in the market for consumer products in more use of WPC as an alternative to pure thermoplastics in injection moulding processes. This work presents the results of numerical simulation and experimental visualisation of the mould filling process in injection moulding of WPC. The 3D injection moulding simulations were done with the commercial software package Autodesk® Moldflow® Insight 2016 (AMI). The mould filling experiments were conducted with a box-shaped test part. In contrast to unfilled polymers the WPC has reduced melt elasticity so that the fountain flow often does not develop. This results in irregular flow front shapes in the moulded part, especially at high filler content.

  19. GRAVITY PIPELINE TRANSPORT FOR HARDENING FILLING MIXTURES

    Directory of Open Access Journals (Sweden)

    Leonid KROUPNIK

    2015-12-01

    Full Text Available In underground mining of solid minerals becoming increasingly common development system with stowing hardening mixtures. In this case the natural ore array after it is replaced by an artificial excavation of solidified filling mixture consisting of binder, aggregates and water. Such a mixture is prepared on the surface on special stowing complexes and transported underground at special stowing pipelines. However, it is transported to the horizons of a few kilometers, which requires a sustainable mode of motion of such a mixture in the pipeline. Hardening stowing mixture changes its rheological characteristics over time, which complicates the calculation of the parameters of pipeline transportation. The article suggests a method of determining the initial parameters of such mixtures: the status coefficient, indicator of transportability, coefficient of hydrodynamic resistance to motion of the mixture. These indicators characterize the mixture in terms of the possibility to transport it through pipes. On the basis of these indicators is proposed methodology for calculating the parameters of pipeline transport hardening filling mixtures in drift mode when traffic on the horizontal part of the mixture under pressure column of the mixture in the vertical part of the backfill of the pipeline. This technique allows stable operation is guaranteed to provide pipeline transportation.

  20. Pairing in half-filled Landau level

    Science.gov (United States)

    Wang, Zhiqiang; Mandal, Ipsita; Chung, Suk Bum; Chakravarty, Sudip

    2015-03-01

    Pairing of composite fermions in half-filled Landau level state is reexamined by solving the BCS gap equation with full frequency dependent current-current interactions. Our results show that there can be a continuous transition from the Halperin-Lee-Read state to a chiral odd angular momentum Cooper pair state for short-range contact interaction. This is at odds with the previously established conclusion of first order pairing transition, in which the low frequency effective interaction was assumed for the entire frequency range. We find that even if the low frequency effective interaction is repulsive, it is compensated by the high frequency regime, which is attractive. We construct the phase diagrams and show that l = 1 angular momentum channel is quite different from higher angular momentum channel l >= 3 . Remarkably, the full frequency dependent analysis applied to the bilayer Hall system with a total filling fraction ν =1/2 +1/2 is quantitatively changed from the previously established results but not qualitatively. This work was supported by US NSF under the Grant DMR-1004520, the funds from the David S. Saxon Presidential Chair at UCLA(37952), and by the Institute for Basic Science in Korea through the Young Scientist grant (5199-2014003).

  1. Monitoring culvert load with shallow filling under Geofoam areas.

    Science.gov (United States)

    2008-08-01

    Geofoam and the "Imperfect Ditch" method can be used effectively on embankment projects to reduce pressures on underground structures when sufficient fill height is available to create an arching effect. When the fill height is too shallow the archin...

  2. WASP and SCAR are evolutionarily conserved in actin-filled pseudopod-based motility

    OpenAIRE

    Fritz-Laylin, Lillian K.; Lord, Samuel J.; Mullins, R Dyche

    2017-01-01

    Diverse eukaryotic cells crawl through complex environments using distinct modes of migration. To understand the underlying mechanisms and their evolutionary relationships, we must define each mode and identify its phenotypic and molecular markers. In this study, we focus on a widely dispersed migration mode characterized by dynamic actin-filled pseudopods that we call ??-motility.? Mining genomic data reveals a clear trend: only organisms with both WASP and SCAR/WAVE?activators of branched a...

  3. Radiopacity of bulk fill flowable resin composite materials | Yildirim ...

    African Journals Online (AJOL)

    Objectives: The purpose of this study was to evaluate the radiopacity of currently marketed bulk fill flowable dental composite materials (Beautifil Bulk Flowable, SDR Flow, Filtek Bulk Fill Flow, and x‑tra Base Bulk Fill). Materials and Methods: Six specimens of each material with a thickness of 1 mm were prepared, and ...

  4. 21 CFR 872.3820 - Root canal filling resin.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Root canal filling resin. 872.3820 Section 872...) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3820 Root canal filling resin. (a) Identification. A root canal filling resin is a device composed of material, such as methylmethacrylate, intended...

  5. 21 CFR 872.3310 - Coating material for resin fillings.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Coating material for resin fillings. 872.3310... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3310 Coating material for resin fillings. (a) Identification. A coating material for resin fillings is a device intended to be applied to the...

  6. Environmental Impact Assessment of Petrol and Gas Filling Stations ...

    African Journals Online (AJOL)

    Environmental Impact Assessment of Petrol and Gas Filling Stations on Air Quality in Umuahia, Nigeria. ... Hence a conclusion was drawn from the findings that the primary pollutant to consider when building filling station are the VOCs and methane and that the minimum safe distance to site a filling station is a distance of ...

  7. 46 CFR 98.25-65 - Filling density.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Filling density. 98.25-65 Section 98.25-65 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CARGO AND MISCELLANEOUS VESSELS SPECIAL... § 98.25-65 Filling density. (a) The filling density, or the percent ratio of the liquefied gas that may...

  8. Numerical simulation of mould filling process for pressure plate and valve handle in LFC

    Directory of Open Access Journals (Sweden)

    Jiang Junxia

    2010-11-01

    Full Text Available In lost foam casting (LFC, the distribution of polymer beads during the bead filling process is not uniform, and the collision between polymer beads determines the distribution of two-phase flow of gas and solid. The interaction between the gas and solid phases reveals as coupling effect of the force that gas exerts on particles or vice versa, or that among particles. The gas-solid flow in filling process is nonlinearity, which makes the coupling effect an essential point to carry out a simulation properly. Therefore, information of each particle’s motion is important for acquiring the law of filling process. In bead filling process, compressed air is pressed into mold cavity, and discharged from gas vent, creating a pressure difference between outer and inner space near the gas vent. This pressure difference directly changes the spatial distribution and motion trace of gas and solid phases. In this paper, Discrete Element Method (DEM and Computational Fluid Dynamics (CFD are employed to simulate the fluid dynamic character based on Newton’s Third Law of Motion. The simulation results of some casting products such as pressure plate and valve handle are compared with the result obtained from practical experiment in order to test the feasibility of DEM. The comparison shows that this DEM method can be a very promising tool in the mould filling simulation of beads’ movement.

  9. Implantation of Perylene Molecules into Glass Plates through a Water Layer Using a Laser Induced Molecular Micro-Jet

    Science.gov (United States)

    Goto, Masahiro; Pihosh, Yuriy; Kasahara, Akira; Tosa, Masahiro

    2006-09-01

    Perylene molecules have been successfully implanted onto borosilicate glass plates, forming fluorescent features of 420 nm in diameter, using a method involving laser induced molecular micro-jet ejection through a water layer. The technique utilises a polymer source film in which perylene molecules are dispersed, a borosilicate glass substrate as a target and a pulsed laser. The space gap between the source film and the target is filled with liquid water. Perylene molecules dispersed in the polymer source films are photo-excited using 4-ns laser pulses resulting in the ejection of the molecules from the source matrix after which they become implanted into the target after passing through the water layer. This new advanced implantation method, using a laser induced molecular micro-jet through water, gives fine spatial control for fixing functional organic molecules in a designated region on hard dielectric materials and will have application in the fabrication of molecular devices, molecular sensors, and opto-electronics.

  10. Photoemission spectroscopy of Ce-filled skutterudites

    Energy Technology Data Exchange (ETDEWEB)

    Matsunami, M. [RIKEN/SPring-8, Hyogo 679 5148 (Japan)]. E-mail: matunami@spring8.or.jp; Horiba, K. [RIKEN/SPring-8, Hyogo 679 5148 (Japan); Taguchi, M. [RIKEN/SPring-8, Hyogo 679 5148 (Japan); Yamamoto, K. [RIKEN/SPring-8, Hyogo 679 5148 (Japan); Chainani, A. [RIKEN/SPring-8, Hyogo 679 5148 (Japan); Takata, Y. [RIKEN/SPring-8, Hyogo 679 5148 (Japan); Senba, Y. [JASRI/SPring-8, Hyogo 679 5148 (Japan); Ohashi, H. [JASRI/SPring-8, Hyogo 679 5148 (Japan); Sugawara, H. [Faculty of Integrated Arts and Sciences, University of Tokushima, Tokushima 770 8502 (Japan); Sato, H. [Department of Physics, Tokyo Metropolitan University, Tokyo 192 0397 (Japan); Harima, H. [Department of Physics, Kobe University, Kobe 657 8501 (Japan); Shin, S. [RIKEN/SPring-8, Hyogo 679 5148 (Japan); Institute of Solid State Physics, University of Tokyo, Kashiwa, Chiba 277 85817 (Japan)

    2006-05-01

    We have investigated the electronic structure of filled skutterudites CeFe{sub 4}P{sub 12} and CeOs{sub 4}Sb{sub 12} by means of Ce 3d-4f resonant photoemission spectroscopy. The difference in the spectral property of on-resonant photoemission spectra can be explained by the degree of hybridization between conduction band states and Ce 4f states. In addition, the spectral intensity at the Fermi level for CeFe{sub 4}P{sub 12} is significantly lower than that for CeOs{sub 4}Sb{sub 12}. The results indicate that a Kondo resonance exists in CeOs{sub 4}Sb{sub 12} while Kondo resonance is suppressed in CeFe{sub 4}P{sub 12}.

  11. Internal Accident Report: fill it out!

    CERN Document Server

    2012-01-01

    It is important to report all accidents, near-misses and dangerous situations so that they can be avoided in the future.   Reporting these events allows the relevant services to take appropriate action and implement corrective and preventive measures. It should be noted that the routing of the internal accident report was recently changed to make sure that the people who need to know are informed. Without information, corrective action is not possible. Without corrective action, there is a risk that the events will recur. As soon as you experience or see something amiss, fill out an internal accident report! If you have any questions the HSE Unit will be happy to answer them. Contact us at safety-general@cern.ch. The HSE Unit

  12. Aging Studies of Filled and Unfilled VCE

    Energy Technology Data Exchange (ETDEWEB)

    Letant, S; Herberg, J; Alviso, C; Small, W; Mulcahy, H; Pearson, M; Wilson, T; Chinn, S; Maxwell, R

    2009-11-10

    This report presents data on the effects of temperature and gamma radiation on the chemical and structural properties of both filled and unfilled VCE material produced by the Kansas City Plant using WR-qualified processes. Thermal effects up to 300 C and gamma irradiation doses of 1 MRad and 25 MRad were investigated under atmospheric conditions. Characterization techniques used in the study comprise Thermogravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC), X-ray Diffraction (XRD), Tensile Testing, Solid Phase MicroExtraction - Gas Chromatography/Mass Spectrometry (SPME-GC/MS), phenol extraction followed by HPLC, and various Nuclear Magnetic Resonance (NMR) techniques including: {sup 13}C, {sup 13}C {l_brace}{sup 1}H{r_brace} cross polarization (CP), {sup 1}H magic angle spinning (MAS), 13C{l_brace}{sup 1}H{r_brace} Wide-line-Separation (2D-WISE) and development of Center band-Only Detection of Exchange (CODEX).

  13. Alleviate Cellular Congestion Through Opportunistic Trough Filling

    Directory of Open Access Journals (Sweden)

    Yichuan Wang

    2014-04-01

    Full Text Available The demand for cellular data service has been skyrocketing since the debut of data-intensive smart phones and touchpads. However, not all data are created equal. Many popular applications on mobile devices, such as email synchronization and social network updates, are delay tolerant. In addition, cellular load varies significantly in both large and small time scales. To alleviate network congestion and improve network performance, we present a set of opportunistic trough filling schemes that leverage the time-variation of network congestion and delay-tolerance of certain traffic in this paper. We consider average delay, deadline, and clearance time as the performance metrics. Simulation results show promising performance improvement over the standard schemes. The work shed lights on addressing the pressing issue of cellular overload.

  14. Form Filling with Self-Compacting Concrete

    DEFF Research Database (Denmark)

    Thrane, Lars Nyholm

    2007-01-01

    endvidere, at Teknologisk Institut vil kommercialisere projektets resultater. Abstract The overall subject of this project was Self-Compacting Concrete. More specifically it has been to establish a modelling approach for prediction of the form filling behaviour of SCC in a vertical formwork. Self...... to the prospects of improving the structural quality, working environment, productivity, and architectural appearance. However, especially in vertical applications there is a great unused potential. Controlling the casting process is important in many different industries such as the metal, plastic, and food...... industry. The casting process may have a significant influence on the finished product and the challenges vary depending on the material characteristics and the type of flow. Concrete may be regarded as a suspension defined as particles dispersed in a matrix phase. When the particles remain homogeneously...

  15. Two variants of minimum discarded fill ordering

    Energy Technology Data Exchange (ETDEWEB)

    D' Azevedo, E.F. (Oak Ridge National Lab., TN (USA)); Forsyth, P.A.; Tang, Wei-Pai (Waterloo Univ., ON (Canada). Dept. of Computer Science)

    1991-01-01

    It is well known that the ordering of the unknowns can have a significant effect on the convergence of Preconditioned Conjugate Gradient (PCG) methods. There has been considerable experimental work on the effects of ordering for regular finite difference problems. In many cases, good results have been obtained with preconditioners based on diagonal, spiral or natural row orderings. However, for finite element problems having unstructured grids or grids generated by a local refinement approach, it is difficult to define many of the orderings for more regular problems. A recently proposed Minimum Discarded Fill (MDF) ordering technique is effective in finding high quality Incomplete LU (ILU) preconditioners, especially for problems arising from unstructured finite element grids. Testing indicates this algorithm can identify a rather complicated physical structure in an anisotropic problem and orders the unknowns in the preferred'' direction. The MDF technique may be viewed as the numerical analogue of the minimum deficiency algorithm in sparse matrix technology. At any stage of the partial elimination, the MDF technique chooses the next pivot node so as to minimize the amount of discarded fill. In this work, two efficient variants of the MDF technique are explored to produce cost-effective high-order ILU preconditioners. The Threshold MDF orderings combine MDF ideas with drop tolerance techniques to identify the sparsity pattern in the ILU preconditioners. These techniques identify an ordering that encourages fast decay of the entries in the ILU factorization. The Minimum Update Matrix (MUM) ordering technique is a simplification of the MDF ordering and is closely related to the minimum degree algorithm. The MUM ordering is especially for large problems arising from Navier-Stokes problems. Some interesting pictures of the orderings are presented using a visualization tool. 22 refs., 4 figs., 7 tabs.

  16. Bacillus anthracis-like bacteria and other B. cereus group members in a microbial community within the International Space Station: a challenge for rapid and easy molecular detection of virulent B. anthracis.

    Directory of Open Access Journals (Sweden)

    Sandra P van Tongeren

    Full Text Available For some microbial species, such as Bacillus anthracis, the etiologic agent of the disease anthrax, correct detection and identification by molecular methods can be problematic. The detection of virulent B. anthracis is challenging due to multiple virulence markers that need to be present in order for B. anthracis to be virulent and its close relationship to Bacillus cereus and other members of the B. cereus group. This is especially the case in environments where build-up of Bacillus spores can occur and several representatives of the B. cereus group may be present, which increases the chance for false-positives. In this study we show the presence of B. anthracis-like bacteria and other members of the B. cereus group in a microbial community within the human environment of the International Space Station and their preliminary identification by using conventional culturing as well as molecular techniques including 16S rDNA sequencing, PCR and real-time PCR. Our study shows that when monitoring the microbial hygiene in a given human environment, health risk assessment is troublesome in the case of virulent B. anthracis, especially if this should be done with rapid, easy to apply and on-site molecular methods.

  17. Bacillus anthracis-like bacteria and other B. cereus group members in a microbial community within the International Space Station: a challenge for rapid and easy molecular detection of virulent B. anthracis.

    Science.gov (United States)

    van Tongeren, Sandra P; Roest, Hendrik I J; Degener, John E; Harmsen, Hermie J M

    2014-01-01

    For some microbial species, such as Bacillus anthracis, the etiologic agent of the disease anthrax, correct detection and identification by molecular methods can be problematic. The detection of virulent B. anthracis is challenging due to multiple virulence markers that need to be present in order for B. anthracis to be virulent and its close relationship to Bacillus cereus and other members of the B. cereus group. This is especially the case in environments where build-up of Bacillus spores can occur and several representatives of the B. cereus group may be present, which increases the chance for false-positives. In this study we show the presence of B. anthracis-like bacteria and other members of the B. cereus group in a microbial community within the human environment of the International Space Station and their preliminary identification by using conventional culturing as well as molecular techniques including 16S rDNA sequencing, PCR and real-time PCR. Our study shows that when monitoring the microbial hygiene in a given human environment, health risk assessment is troublesome in the case of virulent B. anthracis, especially if this should be done with rapid, easy to apply and on-site molecular methods.

  18. Holocene alluvial fills in the South Loup Valley, Nebraska

    Science.gov (United States)

    May, David W.

    1989-07-01

    Four Holocene alluvial fills are present in Nebraska's South Loup River valley. Fill IV, the oldest and thickest, was deposited between 10,200 and 4800 14C yr B.P.; Fill III has an age of about 3000 14C yr B.P.; Fill II is younger than 2100 and older than 900 14C yr B.P.; and Fill I is younger than 900 14C yr B.P. Regional contemporaneity of valley alluviation in the eastcentral Great Plains suggests that climate has controlled long-term sediment storage in the South Loup River valley.

  19. Analysis in Banach spaces

    CERN Document Server

    Hytönen, Tuomas; Veraar, Mark; Weis, Lutz

    2016-01-01

    The present volume develops the theory of integration in Banach spaces, martingales and UMD spaces, and culminates in a treatment of the Hilbert transform, Littlewood-Paley theory and the vector-valued Mihlin multiplier theorem. Over the past fifteen years, motivated by regularity problems in evolution equations, there has been tremendous progress in the analysis of Banach space-valued functions and processes. The contents of this extensive and powerful toolbox have been mostly scattered around in research papers and lecture notes. Collecting this diverse body of material into a unified and accessible presentation fills a gap in the existing literature. The principal audience that we have in mind consists of researchers who need and use Analysis in Banach Spaces as a tool for studying problems in partial differential equations, harmonic analysis, and stochastic analysis. Self-contained and offering complete proofs, this work is accessible to graduate students and researchers with a background in functional an...

  20. Quality of root fillings performed with two root filling techniques. An in vitro study using micro-CT

    DEFF Research Database (Denmark)

    Moeller, L.; Wenzel, A.; Wegge-Larsen, A. M.

    2013-01-01

    technique. All roots were filled with AH plus and gutta-percha. Group 1 was filled using LCT (n = 34) and group 2 was filled using HT (n = 33). The obturation time was measured in 30 cases evenly distributed between the two techniques. Voids in relation to the root canal fillings were assessed using cross......-section images from Micro-computed Tomography scans. Results. All root canal fillings had voids. Permutation test showed no statistically significant difference between the two root filling techniques in relation to presence of voids (p = 0.092). A statistically significant difference in obturation time between...... the two techniques was found (p statistically significant difference in percentage of voids between two root filling techniques. A 40% reduction in obturation time was found for the HT compared to the LCT....

  1. Molecular markers for X-ray-insensitive differentiated cells in the Inner and outer regions of the mesenchymal space in planarian Dugesia japonica.

    Science.gov (United States)

    Teramoto, Machiko; Kudome-Takamatsu, Tomomi; Nishimura, Osamu; An, Yang; Kashima, Makoto; Shibata, Norito; Agata, Kiyokazu

    2016-09-01

    Planarian's strong regenerative ability is dependent on stem cells (called neoblasts) that are X-ray-sensitive and proliferative stem cells. In addition to neoblasts, another type of X-ray-sensitive cells was newly identified by recent research. Thus, planarian's X-ray-sensitive cells can be divided into at least two populations, Type 1 and Type 2, the latter corresponding to planarian's classically defined "neoblasts". Here, we show that Type 1 cells were distributed in the outer region (OR) immediately underneath the muscle layer at all axial levels from head to tail, while the Type 2 cells were distributed in a more internal region (IR) of the mesenchymal space at the axial levels from neck to tail. To elucidate the biological significance of these two regions, we searched for genes expressed in differentiated cells that were locate close to these X-ray-sensitive cell populations in the mesenchymal space, and identified six genes mainly expressed in the OR or IR, named OR1, OR2, OR3, IR1, IR2 and IR3. The predicted amino acid sequences of these genes suggested that differentiated cells expressing OR1, OR3, IR1, or IR2 provide Type 1 and Type 2 cells with specific extracellular matrix (ECM) environments. © 2016 Japanese Society of Developmental Biologists.

  2. THE SPITZER SPACE TELESCOPE SURVEY OF THE ORION A AND B MOLECULAR CLOUDS. II. THE SPATIAL DISTRIBUTION AND DEMOGRAPHICS OF DUSTY YOUNG STELLAR OBJECTS

    Energy Technology Data Exchange (ETDEWEB)

    Megeath, S. T.; Kryukova, E. [Ritter Astrophsical Research Center, Department of Physics and Astronomy, University of Toledo, Toledo, OH 43606 (United States); Gutermuth, R. [Department of Astronomy, University of Massachusetts, Amherst, MA 01003 (United States); Muzerolle, J. [Space Telescope Science Institute, Baltimore, MD 21218 (United States); Hora, J. L.; Myers, P. C.; Fazio, G. G. [Harvard Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States); Allen, L. E. [National Optical Astronomical Observatory, Tucson, AZ 85719 (United States); Flaherty, K. [Steward Observatory, University of Arizona, Tucson, AZ 85721 (United States); Hartmann, L. [Department of Astronomy, University of Michigan, Ann Arbor, MI 48109 (United States); Pipher, J. L. [Department of Physics and Astronomy, University of Rochester, Rochester NY 14627 (United States); Stauffer, J. [Spitzer Science Center, California Institute of Technology, Pasadena, CA 91125 (United States); Young, E. T., E-mail: megeath@physics.utoledo.edu [SOFIA-Universities Space Research Association, NASA Ames Research Center, Moffett Field, CA 94035 (United States)

    2016-01-15

    We analyze the spatial distribution of dusty young stellar objects (YSOs) identified in the Spitzer Survey of the Orion Molecular clouds, augmenting these data with Chandra X-ray observations to correct for incompleteness in dense clustered regions. We also devise a scheme to correct for spatially varying incompleteness when X-ray data are not available. The local surface densities of the YSOs range from 1 pc{sup −2} to over 10,000 pc{sup −2}, with protostars tending to be in higher density regions. This range of densities is similar to other surveyed molecular clouds with clusters, but broader than clouds without clusters. By identifying clusters and groups as continuous regions with surface densities ≥10 pc{sup −2}, we find that 59% of the YSOs are in the largest cluster, the Orion Nebula Cluster (ONC), while 13% of the YSOs are found in a distributed population. A lower fraction of protostars in the distributed population is evidence that it is somewhat older than the groups and clusters. An examination of the structural properties of the clusters and groups shows that the peak surface densities of the clusters increase approximately linearly with the number of members. Furthermore, all clusters with more than 70 members exhibit asymmetric and/or highly elongated structures. The ONC becomes azimuthally symmetric in the inner 0.1 pc, suggesting that the cluster is only ∼2 Myr in age. We find that the star formation efficiency (SFE) of the Orion B cloud is unusually low, and that the SFEs of individual groups and clusters are an order of magnitude higher than those of the clouds. Finally, we discuss the relationship between the young low mass stars in the Orion clouds and the Orion OB 1 association, and we determine upper limits to the fraction of disks that may be affected by UV radiation from OB stars or dynamical interactions in dense, clustered regions.

  3. Volume Changes in Filled Rubber Under Uniaxial Cyclic Loading

    Directory of Open Access Journals (Sweden)

    Elina KAZINA

    2011-09-01

    Full Text Available Styrene-butadiene rubber, neat and filled with different silica content was investigated under uniaxial cyclic loading under a constant crosshead speed, with increasing deformation amplitude in subsequent loading cycles. Rubber was investigated in order to evaluate the reversibility of structure rearrangements, occurring in rubber when subjected to cyclic loading. Volume uniformly increases with growing strain and shows hysteresis at unloading. After complete unloading, no residual strain changes are observed. These data are in good conformity with the data of density measurements, which were made on specimens before and after the tests. By correlating data, obtained from volume changes and kinetics of hysteresis losses there were made assumptions on deformation mechanisms at different elongations. Deformational mechanisms, responsible for volume changes in rubber are reversible. Volume changes in specimen occur due to voids formation caused by filler microstructure breakage, rubber chains disentanglement, spaces between rubber macromolecular chains shrinkage, and chain slippage under higher elongations. Voids formation and deformation of rubber macromolecular chain reaches equilibrium state after certain elongation.http://dx.doi.org/10.5755/j01.ms.17.3.592

  4. Slow Waves in Fractures Filled with Viscous Fluid

    Energy Technology Data Exchange (ETDEWEB)

    Korneev, Valeri

    2008-01-08

    Stoneley guided waves in a fluid-filled fracture generally have larger amplitudes than other waves, and therefore, their properties need to be incorporated in more realistic models. In this study, a fracture is modeled as an infinite layer of viscous fluid bounded by two elastic half-spaces with identical parameters. For small fracture thickness, I obtain a simple dispersion equation for wave-propagation velocity. This velocity is much smaller than the velocity of a fluid wave in a Biot-type solution, in which fracture walls are assumed to be rigid. At seismic prospecting frequencies and realistic fracture thicknesses, the Stoneley guided wave has wavelengths on the order of several meters and an attenuation Q factor exceeding 10, which indicates the possibility of resonance excitation in fluid-bearing rocks. The velocity and attenuation of Stoneley guided waves are distinctly different at low frequencies for water and oil. The predominant role of fractures in fluid flow at field scales is supported by permeability data showing an increase of several orders of magnitude when compared to values obtained at laboratory scales. These data suggest that Stoneley guided waves should be taken into account in theories describing seismic wave propagation in fluid-saturated rocks.

  5. Air-filled vs water-filled intragastric balloon: a prospective randomized study.

    Science.gov (United States)

    Giardiello, Cristiano; Borrelli, Alessandro; Silvestri, Eufemia; Antognozzi, Valentina; Iodice, Giuseppe; Lorenzo, Michele

    2012-12-01

    The positioning of an intragastric saline-filled balloon has been developed as temporary and reversible therapeutic option for treatment of morbid obesity. Recently, an air-filled balloon was also developed. The aim of this study is to prospectively compare these two devices in terms of weight loss parameters, safety, and tolerance. Sixty patients were randomized into two groups: group A (Bioenterics Intragastric Balloon-BIB; n = 30; 20 F/10 M, mean age 36.7 ± 10.9; mean BMI 46.5 ± 5.9) and group B (Endobag-Heliosphere; n = 30; 20 F/10 M, mean age 37.8 ± 10.6; mean BMI 46.1 ± 5.6). All patients of both groups were sedated with midazolam (5 mg) + Propofol (2 mg/kg i.v.). The Heliosphere Bag was air-filled with 950 ml while BIB® was inflated with 500 ml of saline and 10 ml of methylene blue. Percentage of excess weight loss (%EWL) and body mass index (BMI) were evaluated. Student t test, Fisher exact test, and χ(2) test were used for statistical analysis. Similar weight loss parameters were observed in patients treated with liquid or air-filled balloon at time of removal: mean BMI was 40.8 ± 6.2 and 41.9 ± 6.5(p = ns), and mean %EWL was 20 ± 12 and 18 ± 14 (p = ns) in groups A and B, respectively. Significant longer extraction time, with high patient discomfort, was observed in group B due to difficult passage through the cardia and the lower pharynx. Air-filled balloon can be another valid therapeutic option in the temporary treatment of obesity, but at this time, the quality of the device must be improved to ameliorate the patient compliance at removal and avoid the spontaneous deflations.

  6. Epoxy and Silicone Optical Nanocomposites Filled with Grafted Nanoparticles

    Science.gov (United States)

    Tao, Peng

    Polymer nanocomposites, as a technologically important class of materials, exhibit diverse functional properties, and are used for applications ranging from structural and biomedical to electronic and optical. The properties of polymer nanocomposites are determined, in part, by the chemical composition of the polymer matrix and the nanofillers. Their properties are also sensitive to the geometry and size of the nanofillers, and to spatial distribution of the fillers. Control of the nanoparticle size and dispersion within a given polymer provides opportunities to tailor and optimize the properties of nanocomposites for specific application. For optical applications such as encapsulation of light emitting diodes (LEDs), polymer nanocomposites filled with homogeneously dispersed nanoparticles would endow the polymer encapsulant with new functionality without sacrificing optical transparency. To this end, this thesis focuses on developing a simple and versatile approach towards the fabrication of epoxy and silicone transparent nanocomposites using matrix compatible chain-grafted nanoparticles as fillers, and studying the optical properties of the nanocomposites. The surface chemistry and grafted polymer chain design have been shown to play an important role in determining the dispersion state of the grafted nanoparticles and hence the final optical properties of the nanocomposites. To prepare transparent epoxy nanocomposites, poly (glycidyl methacrylate) (PGMA) chains were grafted onto the optical nanoparticle surfaces via a combined phosphate ligand exchange process and azide-alkyne "click" chemistry. The dispersion behavior of PGMA-grafted nanoparticles within the epoxy matrix was investigated by systematically varying the grafting density and grafted chain length. It was found that within the small molecular weight epoxy resins, the dispersion states are more sensitive to the grafting density than the molecular weight of grafted chains. With high grafting densities

  7. Mineral trioxide aggregate root canal filling of traumatized immature tooth

    Directory of Open Access Journals (Sweden)

    Maha A Kanfar

    2013-01-01

    Full Text Available An 8-year-old female patient reported to the dental clinic seeking a help to save her traumatized maxillary left central incisor. The tooth had been treated with a temporary filling by a general dentist. The coronal tooth structure was intact, discolored, and a temporary filling was placed on the access opening. She gave a history of trauma about 3 years back. An intraoral periapical radiograph revealed an open apex and dentin bridge in the middle of the root canal. The root canal and the access opening were filled with very poor filling. The tooth was managed successfully by conservative means using intracanal calcium hydroxide as an intracanal medicament, followed by mineral trioxide aggregate (MTA filling. The access opening was filled with glass ionomer and composite resin restoration. One year and 6-month follow-up demonstrated a clinically asymptomatic and adequately functional tooth, with radiological signs of apical regeneration.

  8. The order and volume fill rates in inventory control systems

    DEFF Research Database (Denmark)

    Thorstenson, Anders; Larsen, Christian

    2014-01-01

    This paper differentiates between an order (line) fill rate and a volume fill rate and specifies their performance for different inventory control systems. When the focus is on filling complete customer orders rather than total demanded quantity the order fill rate would be the preferred service...... level measure. The main result shows how the order and volume fill rates are related in magnitude. Earlier results derived for a single-item, single-stage, continuous review inventory system with backordering and constant lead times controlled by a base-stock policy are extended in different directions...... extensions consider more general inventory control review policies with backordering, as well as some relations between service measures. A particularly important result in the paper concerns an alternative service measure, the customer order fill rate, and shows how this measure always exceeds the other two...

  9. Glass composition and process for sealing void spaces in electrochemical devices

    Science.gov (United States)

    Meinhardt, Kerry D [Richland, WA; Kirby, Brent W [Kennewick, WA

    2012-05-01

    A glass foaming material and method are disclosed for filling void spaces in electrochemical devices. The glass material includes a reagent that foams at a temperature above the softening point of the glass. Expansion of the glass fills void spaces including by-pass and tolerance channels of electrochemical devices. In addition, cassette to cassette seals can also be formed while channels and other void spaces are filled, reducing the number of processing steps needed.

  10. Using the Light Microscopy Module (LMM) on the International Space Station (ISS), The Advanced Colloids Experiment (ACE) and MacroMolecular Biophysics (MMB)

    Science.gov (United States)

    Meyer, William; Foster, William M.; Motil, Brian J.; Sicker, Ronald; Abbott-Hearn, Amber; Chao, David; Chiaramonte, Fran; Atherton, Arthur; Beltram, Alexander; Bodzioney, Christopher M.; hide

    2016-01-01

    The Light Microscopy Module (LMM) was launched to the International Space Station (ISS) in 2009 and began science operations in 2010. It continues to support Physical and Biological scientific research on ISS. During 2016, if all goes as planned, three experiments will be completed: [1] Advanced Colloids Experiments with Heated base-2 (ACE-H2) and [2] Advanced Colloids Experiments with Temperature control (ACE-T1). Preliminary results, along with an overview of present and future LMM capabilities will be presented; this includes details on the planned data imaging processing and storage system, along with the confocal upgrade to the core microscope. [1] a consortium of universities from the State of Kentucky working through the Experimental Program to Stimulate Competitive Research (EPSCoR): Stuart Williams, Gerold Willing, Hemali Rathnayake, et al. and [2] from Chungnam National University, Daejeon, S. Korea: Chang-Soo Lee, et al.

  11. Differentiated muscles are mandatory for gas-filling of the Drosophila airway system

    Directory of Open Access Journals (Sweden)

    Yiwen Wang

    2015-12-01

    Full Text Available At the end of development, organs acquire functionality, thereby ensuring autonomy of an organism when it separates from its mother or a protective egg. In insects, respiratory competence starts when the tracheal system fills with gas just before hatching of the juvenile animal. Cellular and molecular mechanisms of this process are not fully understood. Analyses of the phenotype of Drosophila embryos with malformed muscles revealed that they fail to gas-fill their tracheal system. Indeed, we show that major regulators of muscle formation like Lame duck and Blown fuse are important, while factors involved in the development of subsets of muscles including cardiac and visceral muscles are dispensable for this process, suggesting that somatic muscles (or parts of them are essential to enable tracheal terminal differentiation. Based on our phenotypic data, we assume that somatic muscle defect severity correlates with the penetrance of the gas-filling phenotype. This argues that a limiting molecular or mechanical muscle-borne signal tunes tracheal differentiation. We think that in analogy to the function of smooth muscles in vertebrate lungs, a balance of physical forces between muscles and the elasticity of tracheal walls may be decisive for tracheal terminal differentiation in Drosophila.

  12. Differentiated muscles are mandatory for gas-filling of the Drosophila airway system

    Science.gov (United States)

    Wang, Yiwen; Cruz, Tina; Irion, Uwe; Moussian, Bernard

    2015-01-01

    ABSTRACT At the end of development, organs acquire functionality, thereby ensuring autonomy of an organism when it separates from its mother or a protective egg. In insects, respiratory competence starts when the tracheal system fills with gas just before hatching of the juvenile animal. Cellular and molecular mechanisms of this process are not fully understood. Analyses of the phenotype of Drosophila embryos with malformed muscles revealed that they fail to gas-fill their tracheal system. Indeed, we show that major regulators of muscle formation like Lame duck and Blown fuse are important, while factors involved in the development of subsets of muscles including cardiac and visceral muscles are dispensable for this process, suggesting that somatic muscles (or parts of them) are essential to enable tracheal terminal differentiation. Based on our phenotypic data, we assume that somatic muscle defect severity correlates with the penetrance of the gas-filling phenotype. This argues that a limiting molecular or mechanical muscle-borne signal tunes tracheal differentiation. We think that in analogy to the function of smooth muscles in vertebrate lungs, a balance of physical forces between muscles and the elasticity of tracheal walls may be decisive for tracheal terminal differentiation in Drosophila. PMID:26621831

  13. The order and volume fill rates in inventory control systems

    DEFF Research Database (Denmark)

    Thorstenson, Anders; Larsen, Christian

    2011-01-01

    . The extensions consider general continuous review policies with backordering and some related service measures. Demand is assumed to be generated by a compound renewal process. An important generalization concerns the class of customer order size distributions with increasing failure rate for which the volume......This paper differentiates between an order (line) fill rate and a volume fill rate and specifies their performance for different inventory control systems. When the focus is on filling complete customer orders rather than total quantities the order fill rate would be the preferred service level...

  14. Fundamental relation between molecular geometry and real-space topology. Combined AIM, ELI-D, and ASF analysis of hapticities and intramolecular hydrogen-hydrogen bonds in zincocene-related compounds.

    Science.gov (United States)

    Mebs, Stefan; Chilleck, Maren Annika; Meindl, Kathrin; Hübschle, Christian Bertram

    2014-06-19

    Despite numerous advanced and widely distributed bonding theories such as MO, VB, NBO, AIM, and ELF/ELI-D, complex modes of bonding such as M-Cp*((R)) interactions (hapticities) in asymmetrical metallocenes or weak intramolecular interactions (e.g., hydrogen-hydrogen (H···H) bonds) still remain a challenge for these theories in terms of defining whether or not an atom-atom interaction line (a "chemical bond") should be drawn. In this work the intramolecular Zn-C(Cp*(R)) (R = Me, -(CH2)2NMe2, and -(CH2)3NMe2) and H···H connectivity of a systematic set of 12 zincocene-related compounds is analyzed in terms of AIM and ELI-D topology combined with the recently introduced aspherical stockholder fragment (ASF) surfaces. This computational analysis unravels a distinct dependency of the AIM and ELI-D topology against the molecular geometry for both types of interactions, which confirms and extends earlier findings on smaller sets of compounds. According to these results the complete real-space topology including strong, medium, and weak interactions of very large compounds such as proteins may be reliably predicted by sole inspection of accurately determined molecular geometries, which would on the one hand afford new applications (e.g., accurate estimation of numbers, types, and strengths of intra- and intermolecular interactions) and on the other hand have deep implications on the significance of the method.

  15. Filling Knowledge Gaps with Five Fuel Cycle Studies

    Energy Technology Data Exchange (ETDEWEB)

    Steven J. Piet; Jess Gehin; William Halsey; Temitope Taiwo

    2010-11-01

    During FY 2010, five studies were conducted of technology families’ applicability to various fuel cycle strategies to fill in knowledge gaps in option space and to better understand trends and patterns. Here, a “technology family” is considered to be defined by a type of reactor and by selection of which actinides provide fuel. This report summarizes the higher-level findings; the detailed analyses and results are documented in five individual reports, as follows: • Advanced once through with uranium fuel in fast reactors (SFR), • Advanced once through (uranium fuel) or single recycle (TRU fuel) in high temperature gas cooled reactors (HTGR), • Sustained recycle with Th/U-233 in light water reactors (LWRs), • Sustained recycle with Th/U-233 in molten salt reactors (MSR), and • Several fuel cycle missions with Fusion-Fission Hybrid (FFH). Each study examined how the designated technology family could serve one or more designated fuel cycle missions, filling in gaps in overall option space. Each study contains one or more illustrative cases that show how the technology family could be used to meet a fuel cycle mission, as well as broader information on the technology family such as other potential fuel cycle missions for which insufficient information was available to include with an illustrative case. None of the illustrative cases can be considered as a reference, baseline, or nominal set of parameters for judging performance; the assessments were designed to assess areas of option space and were not meant to be optimized. There is no implication that any of the cases or technology families are necessarily the best way to meet a given fuel cycle mission. The studies provide five examples of 1-year fuel cycle assessments of technology families. There is reasonable coverage in the five studies of the performance areas of waste management and uranium utilization. The coverage of economics, safety, and proliferation resistance and physical protection in

  16. Laboratory Characterization of Cemented Rock Fill for Underhand Cut and Fill Method of Mining

    Science.gov (United States)

    Kumar, Dinesh; Singh, Upendra Kumar; Singh, Gauri Shankar Prasad

    2016-10-01

    Backfilling with controlled specifications is employed for improved ground support and pillar recovery in underground metalliferous mine workings. This paper reports the results of a laboratory study to characterise various mechanical properties of cemented rock fill (CRF) formulations for different compaction levels and cement content percentage for use in underhand cut and fill method of mining. Laboratory test set ups and procedures have been described for conducting compressive and bending tests of CRF block samples. A three dimensional numerical modelling study has also been carried out to overcome the limitations arising due to non-standard dimension of test blocks used in flexural loading test and the test setup devised for this purpose. Based on these studies, specific relations have been established between the compressive and the flexural properties of the CRF. The flexural strength of the wire mesh reinforced CRF is also correlated with its residual strength and the Young's modulus of elasticity under flexural loading condition. The test results of flexural strength, residual flexural strength and modulus show almost linear relations with cement content in CRF. The compressive strength of the CRF block samples is estimated as seven times the flexural strength whereas the compressive modulus is four times the flexural modulus. It has been found that the strengths of CRF of low compaction and no compaction are 75 and 60 % respectively to that of the medium compaction CRF. The relation between the strength and the unit weight of CRF as obtained in this study is significantly important for design and quality control of CRF during its large scale application in underhand cut and fill stopes.

  17. COMSOL Multiphysics Model for HLW Canister Filling

    Energy Technology Data Exchange (ETDEWEB)

    Kesterson, M. R. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-04-11

    The U.S. Department of Energy (DOE) is building a Tank Waste Treatment and Immobilization Plant (WTP) at the Hanford Site in Washington to remediate 55 million gallons of radioactive waste that is being temporarily stored in 177 underground tanks. Efforts are being made to increase the loading of Hanford tank wastes in glass while meeting melter lifetime expectancies and process, regulatory, and product quality requirements. Wastes containing high concentrations of Al2O3 and Na2O can contribute to nepheline (generally NaAlSiO4) crystallization, which can sharply reduce the chemical durability of high level waste (HLW) glass. Nepheline crystallization can occur during slow cooling of the glass within the stainless steel canister. The purpose of this work was to develop a model that can be used to predict temperatures of the glass in a WTP HLW canister during filling and cooling. The intent of the model is to support scoping work in the laboratory. It is not intended to provide precise predictions of temperature profiles, but rather to provide a simplified representation of glass cooling profiles within a full scale, WTP HLW canister under various glass pouring rates. These data will be used to support laboratory studies for an improved understanding of the mechanisms of nepheline crystallization. The model was created using COMSOL Multiphysics, a commercially available software. The model results were compared to available experimental data, TRR-PLT-080, and were found to yield sufficient results for the scoping nature of the study. The simulated temperatures were within 60 ºC for the centerline, 0.0762m (3 inch) from centerline, and 0.2286m (9 inch) from centerline thermocouples once the thermocouples were covered with glass. The temperature difference between the experimental and simulated values reduced to 40 ºC, 4 hours after the thermocouple was covered, and down to 20 ºC, 6 hours after the thermocouple was covered

  18. Space matters: meristem expansion triggers corona formation in Passiflora.

    Science.gov (United States)

    Claßen-Bockhoff, Regine; Meyer, Charlotte

    2016-02-01

    Flower meristems differ from vegetative meristems in various aspects. One characteristic is the capacity for ongoing meristem expansion providing space for new structures. Here, corona formation in four species of Passiflora is investigated to understand the spatio-temporal conditions of its formation and to clarify homology of the corona elements. One bird-pollinated species with a single-rowed tubular corona (Passiflora tulae) and three insect-pollinated species with three (P. standleyi Killip), four (P. foetida L. 'Sanctae Martae') and six (P. foetida L. var. hispida) ray-shaped corona rows are chosen as representative examples for the study. Flower development is documented by scanning electron microscopy. Meristem expansion is reconstructed by morphometric data and correlated with the sequential corona element formation. In all species, corona formation starts late in ontogeny after all floral organs have been initiated. It is closely correlated with meristem expansion. The rows appear with increasing space in centripetal or convergent sequence. Based on the concept of fractionation, space induces primordia formation which is a self-regulating process filling the space completely. Correspondingly, the corona is interpreted as a structure of its own, originating from the receptacle. Considering the principle capacity of flower meristems to generate novel structures widens the view and allows new interpretations in combination with molecular, phylogenetic and morphogenetic data. © The Author 2015. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  19. Cassava For Space Diet

    Science.gov (United States)

    Katayama, Naomi; Yamashita, Masamichi; Njemanze, Philip; Nweke, Felix; Mitsuhashi, Jun; Hachiya, Natumi; Miyashita, Sachiko; Hotta, Atuko

    Space agriculture is an advanced life support enginnering concept based on biological and ecological system ot drive the materials recycle loop and create pleasant life environment on distant planetary bodies. Choice of space diet is one of primary decision required ot be made at designing space agriculture. We propose cassava, Manihot esculenta and, for one major composition of space food materials, and evaluate its value and feasibility of farming and processing it for space diet. Criteria to select space crop species could be stated as follows. 1) Fill th enutritional requirements. There is no perfect food material to meet this requirements without making a combination with others. A set of food materials which are adopted inthe space recipe shall fit to the nutritional requirement. 2) Space food is not just for maintaining physiological activities of human, but an element of human culture. We shall consider joy of dining in space life. In this context, space foos or recipe should be accepted by future astronauts. Food culture is diverse in the world, and has close relatioship to each cultural background. Cassava root tuber is a material to supply mainly energy in the form of carbohydrate, same as cereals and other tuber crops. Cassava leaf is rich in protein high as 5.1 percents about ten times higher content than its tuber. In the food culture in Africa, cassava is a major component. Cassava root tuber in most of its strain contains cyanide, it should be removed during preparation for cooking. However certain strain are less in this cyanogenic compound, and genetically modified cassava can also aboid this problem safely.

  20. Simulation of mould filling process for composite skeleton castings

    Directory of Open Access Journals (Sweden)

    M. Dziuba

    2008-04-01

    Full Text Available In this work authors showed selected results of simulation and experimental studies on temperature distribution during solidification of skeleton casting and mould filling process. The aim of conducted simulations was the choice of thermal and geometrical parameters for the needs of designed calculations of the skeleton castings and the estimation of the guidelines for the technology of manufacturing. The subject of numerical simulation was the analysis of ability of filling the channels of core by liquid metal at estability technological parameters.. Below the assumptions and results of the initial simulated calculations are presented. The total number of the nodes in the casting was 1920 and of the connectors was 5280 what gave filling of 100% for the nodes and 99,56% for the connectors in the results of the simulation. Together it resulted as 99,78 % of filling the volume of the casting. The nodes and connectors were filled up to the 30 level of the casting in the simulation. The all connectors were filled up to the 25 level of the casting in the simulation. Starting from the 25 level individual connectors at the side surface of the casting weren’t filled up. The connectors weren’t supplied by multi-level getting system. The differences of filling the levels are little (maximally 5 per cent.

  1. Prediction of maximum dry density of local granular fills | Worku ...

    African Journals Online (AJOL)

    The paper presents a relation. developed to predict maximum dry density (MDD) in terms of the solid density and the gradation coefficients that characterize the grain size distribution of locally employed granular fill materials. For this purpose, two geologically different soils commonly used as selected fill materials are ...

  2. The automatic liquid nitrogen filling system for GDA detectors

    Indian Academy of Sciences (India)

    The filling is aborted if the software detects any hardware malfunction and an alarm is sounded. A simplified flow chart of the control program for the filling of the first six detectors is shown in figure 3. A LINUX based program has now been developed with graphical user interface. It uses client-server protocol to communicate ...

  3. Understanding die fill variation during mini-tablet production.

    Science.gov (United States)

    Goh, Hui Ping; Heng, Paul Wan Sia; Liew, Celine Valeria

    2017-12-20

    Reproducibility of die fill during tablet production is critical to ensure consistent tablet drug content and mechanical attributes. In the production of mini-tablets, tablets smaller than 6mm, achievement of uniform die fill is much more challenging. Powder flow is often associated with die fill accuracy but this relationship has not been well characterised especially for mini-tablets. In this study, flow properties of different types of granules were characterised. Mini-tablets of 1.8 and 3mm diameters were prepared from the granules using a rotary press with multiple-tip compression tooling. A methodology was established to evaluate mini-tablet die fill variation within and across compaction cycles using data from compression roller displacement and mini-tablet weight. Both sizes of mini-tablets showed similar extents of inter-cycle weight variation that could be associated with granules' inter-particulate friction. However, smaller mini-tablets had higher intra-cycle weight variation due to their narrower die orifices. Multivariate and univariate analyses suggested that gravity fill influenced intra-cycle weight variation of 3mm mini-tablets while suction fill was associated with that of 1.8mm mini-tablets. Possible differences in die fill mechanisms between the mini-tablet sizes were identified and this provided a better insight into die fill variations during the production of mini-tablets. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Grain-filling, chlorophyll content in relation with grain yield ...

    African Journals Online (AJOL)

    The beginning of active phase of grain filling corresponded to the beginning of the degradation of chlorophyll content. The velocity of grain filling was negatively correlated to the number of days to heading (DH). Changes in photosynthesis most closely paralleled changes in chlorophyll content. All these changes occurred ...

  5. Identification of root filling interfaces by microscopy and tomography methods

    NARCIS (Netherlands)

    Zaslansky, P.; Fratzl, P.; Rack, A.; Wu, M.K.; Wesselink, P.R.; Shemesh, H.

    2011-01-01

    Aim  To assess differences in observed cross-sectional areas of root canals and filling materials, as imaged by three microscopy and two tomography methods. Methodology  Six roots filled with laterally compacted Gutta-percha and AH26 were scanned with phase-contrast enhanced microtomography in a

  6. Splicing and local reinforcement of concrete filled FRP tubes.

    Science.gov (United States)

    2014-01-01

    This report includes fulfillment of Task 1 of a multi-task contract to further enhance concrete filled FRP tubes, or : the Bridge in a Backpack. Task 1 investigates and develops a feasible solution for splicing the concrete filled FRP : tubes. This w...

  7. Radiopacity of bulk fill flowable resin composite materials.

    Science.gov (United States)

    Yildirim, T; Ayar, M K; Akdag, M S; Yesilyurt, C

    2017-02-01

    The purpose of this study was to evaluate the radiopacity of currently marketed bulk fill flowable dental composite materials (Beautifil Bulk Flowable, SDR Flow, Filtek Bulk Fill Flow, and x-tra Base Bulk Fill). Six specimens of each material with a thickness of 1 mm were prepared, and digital radiographs were taken, using a CCD sensor along with an aluminum stepwedge and 1 mm-thick tooth slice. The mean gray level of each aluminum stepwedge and selected materials was measured, using the equal-density area tool of Kodak Dental Imaging software. The equivalent thickness of aluminum for each material was then calculated by using the stepwedge values in the CurveExpert version 1.4 program. The radiopacity of bulk fill flowable composites sorted in descending order as follows: Beautifil Bulk Flowable (2.96 mm Al) = x-tra base bulk fill (2.92 mm Al) = SureFil SDR Flow (2.89 mm Al) > Filtek Bulk Fill Flow (2.51 mm Al) (P materials had a radiopacity greater than dentin and enamel; their adequate radiopacity will help the clinicians during radiographic examination of restorations. Bulk fill composite materials have greater radiopacity, enabling clinicians to distinguish the bulk fill composites from dentin and enamel.

  8. The Effects of Iron Filling On Some Mechanical and Physical ...

    African Journals Online (AJOL)

    This research work was aimed at producing particleboard from sawdust (matrix) and iron filling (particulate) under the same conditions as ordinary particleboard produced from sawdust alone and their properties compared. Sawdust –iron fillings particleboards were produced using a sawdust of particle size 1.18mm and ...

  9. 21 CFR 1306.06 - Persons entitled to fill prescriptions.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 9 2010-04-01 2010-04-01 false Persons entitled to fill prescriptions. 1306.06 Section 1306.06 Food and Drugs DRUG ENFORCEMENT ADMINISTRATION, DEPARTMENT OF JUSTICE PRESCRIPTIONS General Information § 1306.06 Persons entitled to fill prescriptions. A prescription for a controlled...

  10. 46 CFR 151.03-21 - Filling density.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Filling density. 151.03-21 Section 151.03-21 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES BARGES CARRYING BULK LIQUID HAZARDOUS MATERIAL CARGOES Definitions § 151.03-21 Filling density. The ratio, expressed as...

  11. Assessment of heavy metals concentration in soils around oil filling ...

    African Journals Online (AJOL)

    GREG

    around oil filling and service stations in the Tamale ... Key words: Oil filling, service station soils, enrichment factor, heavy metals, cadmium, Tamale Metropolis. ...... oil from tanks. Conflict of Interests. The authors declare that there is no conflict of interests regarding the publication of this paper. ACKNOWLEDGEMENTS.

  12. 27 CFR 4.46 - Certificate of nonstandard fill.

    Science.gov (United States)

    2010-04-01

    ..., DEPARTMENT OF THE TREASURY LIQUORS LABELING AND ADVERTISING OF WINE Requirements for Withdrawal of Wine From Customs Custody § 4.46 Certificate of nonstandard fill. A person may import wine in containers not conforming to the metric standards of fill prescribed at § 4.73 if the wine is: (a) Accompanied by a...

  13. Microbiological studies on bacterial isolates from penicillins filling ...

    African Journals Online (AJOL)

    Aseptic processing is a critical method for the preparation of thermolabile sterile parenteral drug products. Sterile β-lactam antibiotics are extremely deactivated by heat, so the method of choice for their processing is through aseptic filling. The consequences of contamination on aseptically-filled products are harmful to the ...

  14. Using Habit Reversal to Decrease Filled Pauses in Public Speaking

    Science.gov (United States)

    Mancuso, Carolyn; Miltenberger, Raymond G.

    2016-01-01

    This study evaluated the effectiveness of simplified habit reversal in reducing filled pauses that occur during public speaking. Filled pauses consist of "uh," "um," or "er"; clicking sounds; and misuse of the word "like." After baseline, participants received habit reversal training that consisted of…

  15. Magnetically Active and Coated Gadolinium-Filled Carbon Nanotubes

    KAUST Repository

    Fidiani, Elok

    2013-08-15

    Gd-filled carbon nanotubes (which include the so-called gadonanotubes(1)) have been attracting much interest due to their potential use in medical diagnostic applications. In the present work, a vacuum filling method was performed to confine gadolinium(III) iodide in carbon nanotubes (CNTs). Filling yields in excess of 50% were obtained. Cleaning and dosing of the external walls was undertaken, as well as the study of the filled CNT magnetic properties. Overall, we found that the encapsulating procedure can lead to reduction of the lanthanide metal and induce disorder in the initial GdI3-type structure. Notwithstanding, the magnetic response of the material is not compromised, retaining a strong paramagnetic response and an effective magnetic moment of similar to 6 mu B. Our results may entice further investigation into whether an analogous Gd3+ to Gd2+ reduction takes place in other Gd-filled CNT systems.

  16. Root canal filling evaluation using optical coherence tomography

    Science.gov (United States)

    Negrutiu, Meda L.; Sinescu, Cosmin; Hughes, Michael; Bradu, Adrian; Todea, Carmen; Balabuc, Cosmin I.; Filip, Laura M.; Podoleanu, Adrian Gh.

    2008-04-01

    The root canal fillings are destined to seal the root canal especially in the apical areea. Invasive techniques are known which are used to assess the quality of the seal. These lead to the destruction of the probes and often no conclusion could be drawn in respect to the existence of any microleakage in the investigated areas of interest. Optical coherence tomography (OCT) is a relatively novel non-invasive imaging technique which presents potential in assessing the microleakage of the apical area in the root canal fillings with micron depth resolution. 3D reconstruction allows a complete view with obvious display of gaps in the apical root canal filling. For this study, 30 monoradicular teeth were prepared by conventional and rotative methods. Afterwards, root canal fillings were produced in each tooth. The images obtained show some microleakage in all the investigated root canal fillings. The advantages of the OCT method consist in non-invasiveness and high resolution.

  17. Crystalline arrays of pairs of molecular rotors: correlated motion, rotational barriers, and space-inversion symmetry breaking due to conformational mutations.

    Science.gov (United States)

    Lemouchi, Cyprien; Iliopoulos, Konstantinos; Zorina, Leokadiya; Simonov, Sergey; Wzietek, Pawel; Cauchy, Thomas; Rodríguez-Fortea, Antonio; Canadell, Enric; Kaleta, Jiří; Michl, Josef; Gindre, Denis; Chrysos, Michael; Batail, Patrick

    2013-06-26

    The rod-like molecule bis((4-(4-pyridyl)ethynyl)bicyclo[2.2.2]oct-1-yl)buta-1,3-diyne, 1, contains two 1,4-bis(ethynyl)bicyclo[2.2.2]octane (BCO) chiral rotators linked by a diyne fragment and self-assembles in a one-dimensional, monoclinic C2/c centrosymmetric structure where two equilibrium positions with large occupancy imbalance (88% versus 12%) are identified on a single rotor site. Combining variable-temperature (70-300 K) proton spin-lattice relaxation, (1)H T1(-1), at two different (1)H Larmor frequencies (55 and 210 MHz) and DFT calculations of rotational barriers, we were able to assign two types of Brownian rotators with different activation energies, 1.85 and 6.1 kcal mol(-1), to the two (1)H spin-lattice relaxation processes on the single rotor site. On the basis of DFT calculations, the low-energy process has been assigned to adjacent rotors in a well-correlated synchronous motion, whereas the high-energy process is the manifestation of an abrupt change in their kinematics once two blades of adjacent rotors are seen to rub together. Although crystals of 1 should be second harmonic inactive, a large second-order optical response is recorded when the electric field oscillates in a direction parallel to the unique rotor axle director. We conclude that conformational mutations by torsional interconversion of the three blades of the BCO units break space-inversion symmetry in sequences of mutamers in dynamic equilibrium in the crystal in domains at a mesoscopic scale comparable with the wavelength of light used. A control experiment was performed with a crystalline film of a similar tetrayne molecule, 1,4-bis(3-((trimethylsilyl)ethynyl)bicyclo[1.1.1]pent-1-yl)buta-1,3-diyne, whose bicyclopentane units can rotate but are achiral and produce no second-order optical response.

  18. Handbook of molecular plasmonics

    CERN Document Server

    Sala, Fabio Della

    2013-01-01

    While several reviews and books on surface nanophotonics and fluorescence spectroscopy are available, an updated focus on molecular plasmonics, including both theoretical methods and experimental aspects, is still lacking. This handbook is a comprehensive overview on the physics of the plasmon-emitter interaction, ranging from electromagnetism to quantum mechanics, from metal-enhanced fluorescence to surface-enhanced Raman scattering, from optical microscopy to synthesis of metal nanoparticles, filling the gap in the literature of this merging field. It allows experimentalists to have a solid

  19. ADVANTAGES AND DISADVANTAGES OF THE SONICFILL™ METHOD FOR LATERAL FILLINGS

    Directory of Open Access Journals (Sweden)

    Nicolae BARANOV

    2017-06-01

    Full Text Available The aim of the study was to evaluate the advantages and disadvantages of bulk-fill type fillings realized with SONICFill™ over an 18 month interval, on a batch of patients with different ages and occupations. Materials and methods: the study was performed on a batch of 73 patients who addressed the Clinical of OdontologyEndodontics within the Platform of Practical Training (PIP of the Faculty of Dental Medicine of the ”Apollonia” University of Iaşi, between Octomber 1, 2014 - May 1, 2016, subjected to 91 bulk-fill fillings with SonicFill™ on the posterior teeth. Results and discussion: out of the total number of 73 patients, 56 came from the urban environment, and 17 - from the rural medium, the highest ratio being represented by the 21-30 year age group (45%, closely followed by the 31-40 year one (40%. As for gender distribution within the batch, nearly two-thirds are women, the rest being men. The education level influenced patients’ decision – that of accepting a new method of filling application. As to the types of teeth to which restorations were applied, the highest ratio is represented by lower molars (41%, followed by upper molars (23% and mandibular premolars (20%, the lowest number of restorations being applied to maxillary premolars. Out of the total number of 91 bulk-fill restorations, 28 were applied over a base filling while, in 63 restorations, the basic filling was absent. Conclusions: The SonicFill ™ system for bulk-fill posterior restorations has a number of advantages, such as: high photopolymerization depth, significant reduction of setting contraction, better composite adaptation to the cavity walls, long-term predictable clinical results.

  20. A molecular mechanics study of the effect of substitution in position 1 on the conformational space of the oxytocin/vasopressin ring

    Science.gov (United States)

    Tarnowska, Monika; Liwo, Adam; Shenderovich, Mark D.; Liepiņa, Inta; Golbraikh, Alexander A.; Grzonka, Zbigniew; Tempczyk, Anna

    1993-12-01

    The effect of the substitution in position 1 on the low-energy conformations of the oxytocin/vasopressin 20-membered ring was investigated by means of molecular mechanics. Three representative substitutions were considered: β'-mercapto-β,β-dimethyl)propionic acid (Dmp), (β'-mercapto-β,β-cyclopentamethylene)propionic acid (Cpp), both forming strong antagonists, and (α,α-dimethyl-β-mercapto)propionic acid (α-Dmp), forming analogs of strongly reduced biological activity, with the β-mercaptopropionic (Mpa) residue taken as reference. Both ECEPP/2 (rigid valence geometry) and AMBER (flexible valence geometry) force fields were employed in the calculations. Three basic types of backbone conformations were taken into account which are distinguished by the type of β-turn at residues 3 and 4: β1/βIII, βII, and βI'/βIII', all types containing one or two intra-annular hydrogen bonds. The allowed (ring-closed) disulfide-bridge conformations were searched by an algorithm formulated in terms of scanning the disulfide-bridge torsional angle Cβ-S-S-Cβ. The ECEPP/2 and AMBER energies of the obtained conformations were found to be in reasonable agreement. Two of the low-energy conformers of the [Mpa1]-compound agreed very well with the cyclic part of the two conformers found in the crystal structure of [Mpa1]-oxytocin. An analysis of the effect of β-substitution on relative energies showed that the conformations with the N-C'-CH2-CH2 (ψ'1) and C'-CH2-CH2-S (ϰ'1) angles of the first residue around (-100°, 60°) and (100°, -60°) are not affected; this in most cases implies a left-handed disulfide bridge. In the case of α-substitution the allowed values of ψ'1 are close to ± 60°. This requirement, being in contradiction to the one concerning β-substitution, could explain the very low biological activity of the α-substituted analogs. The conformational preferences of substituted compounds can largely be explained by the analysis of local interactions

  1. Cryogenic Thermal Performance Testing of Bulk-Fill and Aerogel Insulation Materials

    Science.gov (United States)

    Scholtens, B. E.; Fesmire, J. E.; Sass, J. P.; Augustynowicz, S. D.; Heckle, K. W.

    2007-01-01

    The research testing and demonstration of new bulk-fill materials for cryogenic thermal insulation systems was performed by the Cryogenics Test Laboratory at NASA Kennedy Space Center. Thermal conductivity testing under actual-use cryogenic conditions is a key to understanding the total system performance encompassing engineering, economics, and materials factors. A number of bulk fill insulation materials, including aerogel beads, glass bubbles, and perlite powder, were tested using a new cylindrical cryostat. Boundary temperatures for the liquid nitrogen boil-off method were 293 K and 78 K. Tests were performed as a function of cold vacuum pressure from high vacuum to no vacuum conditions. Results are compared with other complementary test methods in the range of 300 K to 20 K. Various testing techniques are shown to be required to obtain a complete understanding of the operating performance of a material and to provide data for answers to design engineering questions.

  2. Black Sprayable Molecular Adsorber Coating Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This novel molecular adsorber coating would alleviate the size, weight, and complexity issues of traditional molecular adsorber puck.  A flexible tape version...

  3. SPS batch spacing optimisation

    CERN Document Server

    Velotti, F M; Carlier, E; Goddard, B; Kain, V; Kotzian, G

    2017-01-01

    Until 2015, the LHC filling schemes used the batch spac-ing as specified in the LHC design report. The maximumnumber of bunches injectable in the LHC directly dependson the batch spacing at injection in the SPS and hence onthe MKP rise time.As part of the LHC Injectors Upgrade project for LHCheavy ions, a reduction of the batch spacing is needed. In thisdirection, studies to approach the MKP design rise time of150ns(2-98%) have been carried out. These measurementsgave clear indications that such optimisation, and beyond,could be done also for higher injection momentum beams,where the additional slower MKP (MKP-L) is needed.After the successful results from 2015 SPS batch spacingoptimisation for the Pb-Pb run [1], the same concept wasthought to be used also for proton beams. In fact, thanksto the SPS transverse feed back, it was already observedthat lower batch spacing than the design one (225ns) couldbe achieved. For the 2016 p-Pb run, a batch spacing of200nsfor the proton beam with100nsbunch spacing wasreque...

  4. New Discoveries Fill the Quasar Gap

    Science.gov (United States)

    Kohler, Susanna

    2017-04-01

    Quasars active and luminous galactic centers can be difficult to find at some high redshifts due to their camouflaging color. A team of scientists has now come up with a way to detect these distant monsters in spite of their disguise.Quasar CamouflageThe color track of quasars between 5 z 6 in the commonly used i z and r i bands. Each dot on the red line marks a 0.1 difference in redshift. The contours show the colors of M dwarfs, from early type to late type. Quasars at a redshift of 5.3 z 5.7 are clearly contaminated by M dwarfs, making them difficult to identify. [Adapted from Yang et al. 2017]One of the key ways we can study the early universe is by building a large sample of high-redshift quasars. In particular, we believe that reionization of the universe is just completing around z 6. Quasars near this redshift are crucial tools for probing the post-reionization epoch and exploring the evolution of the intergalactic medium, quasar evolution, and early supermassive black hole growth.But quasars at this redshift are difficult to detect! The problem is contamination: quasars at this distance are the same color in commonly used optical bands as cool M-dwarf stars. As a result, surveys searching for quasars have often just cut out that entire section of the color space in order to avoid this contamination.This means that theres a huge gap in our sample of quasars around z 5.5: of the more than 300,000 quasars known, only 30 have been found in the redshift range of 5.3 z 5.7.The addition of new colorcolor selection criteria using infrared bands (bottom two plots) allows the authors to differentiate quasars (blue) from M dwarfs (grey), which isnt possible when only the traditional optical colorcolor selection criteria are used (top plot). [Adapted from Yang et al. 2017]A New ApproachIn a recent publication led by Jinyi Yang (Peking University, China and Steward Observatory, University of Arizona), a team of scientists has demonstrated a new technique for finding

  5. Direct composite resin fillings versus amalgam fillings for permanent or adult posterior teeth.

    Science.gov (United States)

    Rasines Alcaraz, M Graciela; Veitz-Keenan, Analia; Sahrmann, Philipp; Schmidlin, Patrick Roger; Davis, Dell; Iheozor-Ejiofor, Zipporah

    2014-03-31

    Amalgam has been the traditional material for filling cavities in posterior teeth for the last 150 years and, due to its effectiveness and cost, amalgam is still the restorative material of choice in certain parts of the world. In recent times, however, there have been concerns over the use of amalgam restorations (fillings), relating to the mercury release in the body and the environmental impact following its disposal. Resin composites have become an esthetic alternative to amalgam restorations and there has been a remarkable improvement of its mechanical properties to restore posterior teeth.There is need to review new evidence comparing the effectiveness of both restorations. To examine the effects of direct composite resin fillings versus amalgam fillings for permanent posterior teeth, primarily on restoration failure. We searched the Cochrane Oral Health Group's Trials Register (to 22 October 2013), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2013, Issue 9), MEDLINE via OVID (1946 to 22 October 2013), EMBASE via OVID (1980 to 22 October 2013), and LILACs via BIREME Virtual Health Library (1980 to 22 October 2013). We applied no restrictions on language or date of publication when searching the electronic databases. We contacted manufacturers of dental materials to obtain any unpublished studies. Randomized controlled trials comparing dental resin composites with dental amalgams in permanent posterior teeth. We excluded studies having a follow-up period of less than three years. We used standard methodological procedures expected by The Cochrane Collaboration. Of the 2205 retrieved references, we included seven trials (10 articles) in the systematic review. Two trials were parallel group studies involving 1645 composite restorations and 1365 amalgam restorations (921 children) in the analysis. The other five trials were split-mouth studies involving 1620 composite restorations and 570 amalgam restorations in an unclear

  6. Modeling and Fault Simulation of Propellant Filling System

    Science.gov (United States)

    Jiang, Yunchun; Liu, Weidong; Hou, Xiaobo

    2012-05-01

    Propellant filling system is one of the key ground plants in launching site of rocket that use liquid propellant. There is an urgent demand for ensuring and improving its reliability and safety, and there is no doubt that Failure Mode Effect Analysis (FMEA) is a good approach to meet it. Driven by the request to get more fault information for FMEA, and because of the high expense of propellant filling, in this paper, the working process of the propellant filling system in fault condition was studied by simulating based on AMESim. Firstly, based on analyzing its structure and function, the filling system was modular decomposed, and the mathematic models of every module were given, based on which the whole filling system was modeled in AMESim. Secondly, a general method of fault injecting into dynamic system was proposed, and as an example, two typical faults - leakage and blockage - were injected into the model of filling system, based on which one can get two fault models in AMESim. After that, fault simulation was processed and the dynamic characteristics of several key parameters were analyzed under fault conditions. The results show that the model can simulate effectively the two faults, and can be used to provide guidance for the filling system maintain and amelioration.

  7. Experimental evaluation of gas filled plenum (GFP) insulation for ducts

    Energy Technology Data Exchange (ETDEWEB)

    Walker, Iain S.; Guillot, Cyril

    2003-01-26

    Forced-air heating and cooling system ducts are often located outside conditioned space in US houses. For these systems to perform efficiently it is important that these ducts be well insulated. Common practice is to use a glass fiber wrap around the ducts--either field applied or more commonly, integrated into a flexible duct. Most duct insulation has an R-value of 4.2, with R6 and R8 ducts also occasionally used. With glass fiber insulation being about R4 per inch (RSI 0.28/cm), this adds 2 to 4 inches (50 to 100 mm) to the duct diameter. Some building codes are now requiring these higher insulation levels, for example, the EPA requires the use of R6 ducts, and International Energy Conservation Code (BOCA 2003) requires R8 ducts. The difficulty with adding insulation to ducts is the increase in diameter of the ducts that makes them expensive to transport because they take up a large volume and are difficult to install in the confined spaces available for ducts in houses. The objective of this study was to evaluate Gas Filled Plenum (GFP) technology as an alternative duct insulation. GFP ducts have the potential to provide greater insulation levels than existing ducts (for a given thickness of insulation or size of duct) and provide cost savings in transportation. These transportation cost savings are based on the idea of shipping the GFP ducts empty and inflating them on-site. To evaluate this technology for ducts we constructed a prototype duct and determined both its flow and heat transfer resistance in LBNL's duct testing laboratories. The GFP technology works by encapsulating a gas (usually air--but other noble gases such as Argon or Krypton can provide significant increases in thermal resistance with increased cost) in a metalized film jacket. A honeycomb structure is used to keep individual gas pockets small to minimize convection heat transfer. A metallic finish (usually aluminum) minimizes radiation heat transfer between the surfaces.

  8. Experimental evaluation of gas filled plenum (GFP) insulation for ducts

    Energy Technology Data Exchange (ETDEWEB)

    Walker, Iain S.; Guillot, Cyril

    2003-01-26

    Forced-air heating and cooling system ducts are often located outside conditioned space in US houses. For these systems to perform efficiently it is important that these ducts be well insulated. Common practice is to use a glass fiber wrap around the ducts--either field applied or more commonly, integrated into a flexible duct. Most duct insulation has an R-value of 4.2, with R6 and R8 ducts also occasionally used. With glass fiber insulation being about R4 per inch (RSI 0.28/cm), this adds 2 to 4 inches (50 to 100 mm) to the duct diameter. Some building codes are now requiring these higher insulation levels, for example, the EPA requires the use of R6 ducts (for Energy Star ducts), and International Energy Conservation Code (BOCA 2003) requires R8 ducts. The difficulty with adding insulation to ducts is the increase in diameter of the ducts that makes them expensive to transport because they take up a large volume and are difficult to install in the confined spaces available for ducts in houses. The objective of this study was to evaluate Gas Filled Plenum (GFP) technology as an alternative duct insulation. GFP ducts have the potential to provide greater insulation levels than existing ducts (for a given thickness of insulation or size of duct) and provide cost savings in transportation. These transportation cost savings are based on the idea of shipping the GFP ducts empty and inflating them on-site. To evaluate this technology for ducts we constructed a prototype duct and determined both its flow and heat transfer resistance in LBNL's duct testing laboratories. The GFP technology works by encapsulating a gas (usually air--but other noble gases such as Argon or Krypton can provide significant increases in thermal resistance with increased cost) in a metalized film jacket. A honeycomb structure is used to keep individual gas pockets small to minimize convection heat transfer. A metallic finish (usually aluminum) minimizes radiation heat transfer between the

  9. Valley fill in the Roswell-Artesia area, New Mexico

    Science.gov (United States)

    Lyford, Forest P.

    1973-01-01

    Drill samples from 225 water and oil wells in an area 70 miles long and 20 miles wide in the Roswell-Artesia area, southeastern New Mexico were examined. A thickness map and a saturated thickness map of the valley-fill sediments were constructed. Maximum depth of valley fill is about 300 feet in large closed depressions near Roswell, Hagerman, and Artesia. The depressions were formed by the solution of carbonates and evaporites that underlie the fill. Maximum saturated thickness is about 250 feet in depressions near Hagerman and Artesia and about 300 feet in a depression near Roswell.

  10. The dynamic response of carbon fiber-filled polymer composites

    OpenAIRE

    Patterson B.; Orler E.B.; Furmanski J.; Rigg P.A.; Scharff R.J.; Stahl D.B.; Sheffield S.A.; Gustavsen R.L.; Dattelbaum D.M.; Coe J.D.

    2012-01-01

    The dynamic (shock) responses of two carbon fiber-filled polymer composites have been quantified using gas gun-driven plate impact experimentation. The first composite is a filament-wound, highly unidirectional carbon fiber-filled epoxy with a high degree of porosity. The second composite is a chopped carbon fiber- and graphite-filled phenolic resin with little-to-no porosity. Hugoniot data are presented for the carbon fiber-epoxy (CE) composite to 18.6 GPa in the through-thickness direction,...

  11. Radio resource management using geometric water-filling

    CERN Document Server

    He, Peter; Zhou, Sheng; Niu, Zhisheng

    2014-01-01

    This brief introduces the fundamental theory and development of managing radio resources using a water-filling algorithm that can optimize system performance in wireless communication. Geometric Water-Filling (GWF) is a crucial underlying tool in emerging communication systems such as multiple input multiple output systems, cognitive radio systems, and green communication systems. Early chapters introduce emerging wireless technologies and provide a detailed analysis of water-filling. The brief investigates single user and multi-user issues of radio resource management, allocation of resources

  12. Thermoelectric materials with filled skutterudite structure for thermoelectric devices

    Science.gov (United States)

    Fleurial, Jean-Pierre (Inventor); Borshchevsky, Alex (Inventor); Caillat, Thierry (Inventor); Morelli, Donald T. (Inventor); Meisner, Gregory P. (Inventor)

    2002-01-01

    A class of thermoelectric compounds based on the skutterudite structure with heavy filling atoms in the empty octants and substituting transition metals and main-group atoms. High Seebeck coefficients and low thermal conductivities are achieved in combination with large electrical conductivities in these filled skutterudites for large ZT values. Substituting and filling methods are disclosed to synthesize skutterudite compositions with desired thermoelectric properties. A melting and/or sintering process in combination with powder metallurgy techniques is used to fabricate these new materials.

  13. The structure of PX{sub 3} (X = Cl, Br, I) molecular liquids from X-ray diffraction, molecular dynamics simulations, and reverse Monte Carlo modeling

    Energy Technology Data Exchange (ETDEWEB)

    Pothoczki, Szilvia, E-mail: pothoczki.szilvia@wigner.mta.hu; Temleitner, László; Pusztai, László [Institute for Solid State Physics and Optics, Wigner Research Centre for Physics, Hungarian Academy of Sciences, Konkoly-Thege M. út 29-33, 1121 Budapest (Hungary)

    2014-02-07

    Synchrotron X-ray diffraction measurements have been conducted on liquid phosphorus trichloride, tribromide, and triiodide. Molecular Dynamics simulations for these molecular liquids were performed with a dual purpose: (1) to establish whether existing intermolecular potential functions can provide a picture that is consistent with diffraction data and (2) to generate reliable starting configurations for subsequent Reverse Monte Carlo modelling. Structural models (i.e., sets of coordinates of thousands of atoms) that were fully consistent with experimental diffraction information, within errors, have been prepared by means of the Reverse Monte Carlo method. Comparison with reference systems, generated by hard sphere-like Monte Carlo simulations, was also carried out to demonstrate the extent to which simple space filling effects determine the structure of the liquids (and thus, also estimating the information content of measured data). Total scattering structure factors, partial radial distribution functions and orientational correlations as a function of distances between the molecular centres have been calculated from the models. In general, more or less antiparallel arrangements of the primary molecular axes that are found to be the most favourable orientation of two neighbouring molecules. In liquid PBr{sub 3} electrostatic interactions seem to play a more important role in determining intermolecular correlations than in the other two liquids; molecular arrangements in both PCl{sub 3} and PI{sub 3} are largely driven by steric effects.

  14. The occurrence of spoilage yeasts in cream-filled bakery products.

    Science.gov (United States)

    Osimani, Andrea; Milanović, Vesna; Taccari, Manuela; Cardinali, Federica; Pasquini, Marina; Aquilanti, Lucia; Clementi, Francesca

    2017-04-01

    Filling creams can provide an adequate substrate for spoilage yeasts because some yeasts can tolerate the high osmotic stress in these products. To discover the source of spoilage of a cream-filled baked product, end products, raw materials, indoor air and work surfaces were subjected to microbiological and molecular analyses. The efficacy of disinfectants against spoilage yeasts was also assessed. The analyses on end products revealed the presence of the closest relatives to Zygosaccharomyces bailii with counts ranging from 1.40 to 4.72 log cfu g(-1) . No spoilage yeasts were found in the indoor air and work surfaces. Polymerase chain reaction-denaturing gradient gel electrophoresis analysis, carried out directly on filling creams collected from unopened cans, showed the presence of bands ascribed to the closest relatives to Z. bailii sensu lato, although with counts < 1 log cfu g(-1) . Susceptibility testing of yeast isolates to disinfectants showed a significantly lower effect of 10% alkyl dimethyl benzyl ammonium chloride. Different responses of isolates to the tested disinfectants were seen. To guarantee the quality of end products, reliable and sensitive methods must be used. Moreover, hygiene and the application of good manufacturing practices represent the most efficient way for the prevention and minimization of cross-contamination. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  15. WASP and SCAR are evolutionarily conserved in actin-filled pseudopod-based motility.

    Science.gov (United States)

    Fritz-Laylin, Lillian K; Lord, Samuel J; Mullins, R Dyche

    2017-06-05

    Diverse eukaryotic cells crawl through complex environments using distinct modes of migration. To understand the underlying mechanisms and their evolutionary relationships, we must define each mode and identify its phenotypic and molecular markers. In this study, we focus on a widely dispersed migration mode characterized by dynamic actin-filled pseudopods that we call "α-motility." Mining genomic data reveals a clear trend: only organisms with both WASP and SCAR/WAVE-activators of branched actin assembly-make actin-filled pseudopods. Although SCAR has been shown to drive pseudopod formation, WASP's role in this process is controversial. We hypothesize that these genes collectively represent a genetic signature of α-motility because both are used for pseudopod formation. WASP depletion from human neutrophils confirms that both proteins are involved in explosive actin polymerization, pseudopod formation, and cell migration. WASP and WAVE also colocalize to dynamic signaling structures. Moreover, retention of WASP together with SCAR correctly predicts α-motility in disease-causing chytrid fungi, which we show crawl at >30 µm/min with actin-filled pseudopods. By focusing on one migration mode in many eukaryotes, we identify a genetic marker of pseudopod formation, the morphological feature of α-motility, providing evidence for a widely distributed mode of cell crawling with a single evolutionary origin. © 2017 Fritz-Laylin et al.

  16. Enhanced Reliability MEMS Deformable Mirrors for Space Imaging Applications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The goal of this project is to develop and demonstrate a reliable, fault-tolerant wavefront control system that will fill a critical technology gap in NASA's vision...

  17. 3D integrated HYDRA simulations of hohlraums including fill tubes

    Science.gov (United States)

    Marinak, M. M.; Milovich, J.; Hammel, B. A.; Macphee, A. G.; Smalyuk, V. A.; Kerbel, G. D.; Sepke, S.; Patel, M. V.

    2017-10-01

    Measurements of fill tube perturbations from hydro growth radiography (HGR) experiments on the National Ignition Facility show spoke perturbations in the ablator radiating from the base of the tube. These correspond to the shadow of the 10 μm diameter glass fill tube cast by hot spots at early time. We present 3D integrated HYDRA simulations of these experiments which include the fill tube. Meshing techniques are described which were employed to resolve the fill tube structure and associated perturbations in the simulations. We examine the extent to which the specific illumination geometry necessary to accommodate a backlighter in the HGR experiment contributes to the spoke pattern. Simulations presented include high resolution calculations run on the Trinity machine operated by the Alliance for Computing at Extreme Scale (ACES) partnership. This work was performed under the auspices of the Lawrence Livermore National Security, LLC, (LLNS) under Contract No. DE-AC52-07NA27344.

  18. Is a three-dimensional-printed tooth filling possible?

    Directory of Open Access Journals (Sweden)

    Muhammet Kerim Ayar

    2016-01-01

    Full Text Available Introduction: Three-dimensional (3-D printing is seen as an innovative production process in many fields of dentistry and medicine. But implantation of this novel production process into the treatment of decayed teeth in dentistry remains lacking. Destruction of dental tissues as a result of dental caries is generally treated with dental resin composite fillings. However, a 3-D-printed tooth filling approach, which could be an alternative to traditional approaches, has a potential to reduce treatment costs and technique-sensitivity of the placement of restorative material. The Hypothesis: Here, the hypothesis that a 3-D-printed tooth filling approach could be an alternative to traditional approaches to treatment of decayed teeth is proposed. Evaluation of the Hypothesis: The actual implementation of the 3-D-printed tooth filling technique in the practice of restorative dentistry was discussed in this manuscript.

  19. Influence of filling pattern structure on synchrotron radiation and beam spectrum at ANKA

    Energy Technology Data Exchange (ETDEWEB)

    Steinmann, Johannes; Brosi, Miriam; Bruendermann, Erik; Caselle, Michele; Blomley, Edmund; Hiller, Nicole; Kehrer, Benjamin; Mueller, Anke-Susanne; Schoenfeldt, Patrik; Schuh, Marcel; Schwarz, Markus; Siegel, Michael [Karlsruher Institut fuer Technologie, Karlsruhe (Germany)

    2016-07-01

    We present the effects of the filling pattern structure in multi-bunch mode on the beam spectrum. This effects can be seen by all detectors whose resolution is better than the RF frequency, ranging from stripline and Schottky measurements to high resolution synchrotron radiation measurements. Our heterodyne measurements of the emitted coherent synchrotron radiation at 270 GHz reveal the discrete frequency harmonics around the 100'000 revolution harmonic of ANKA, the synchrotron radiation facility in Karlsruhe, Germany. Significant effects of bunch spacing, gaps between bunch trains and variations in individual bunch currents on the emitted CSR spectrum are described by theory and supported by observations.

  20. Holstein-Hubbard model at half filling: A static auxiliary field study

    Science.gov (United States)

    Pradhan, Saurabh; Pai, G. Venketeswara

    2015-10-01

    We study the Holstein-Hubbard model at half filling to explore the ordered phases such as the charge density wave and antiferromagnet. The Coulomb interaction is rewritten in terms of auxiliary fields. By treating the auxiliary fields and phonons as classical, we obtain real-space features of the system and transition between the phases from weak to strong coupling. When both interactions are weak, mutual competition between them leads to a metallic phase in an otherwise insulator-dominated phase diagram. Spatial correlations induced by thermal fluctuations lead to pseudogap features at intermediate range of coupling.

  1. Novel use of an air-filled breast prosthesis to allow radiotherapy to recurrent colonic cancer.

    LENUS (Irish Health Repository)

    O'Duffy, F

    2011-03-01

    AiM: The authors present the novel and successful use of an air-filled breast prosthesis for extra pelvic exclusion of small bowel to facilitate adjuvant radiotherapy following resection of recurrent adenocarcinoma of the ascending bowel. The therapeutic use of radiotherapy in colon cancer can cause acute or chronic radiation enteropathy. Mobile small bowel can be sequestered in \\'dead space\\' or by adhesions exposing it to adjuvant radiotherapy. A variety of pelvic partitioning methods have been described to exclude bowel from radiation fields using both native and prosthetic materials.

  2. The Performance Evaluation of Concrete Filled Steel Tubular Arch Bridge

    OpenAIRE

    Ma Wei-long

    2015-01-01

    In this paper, the system assessment theory of he concrete filled steel tubular arch bridge which is based on the theory of the reliability of system reliability is researched through the finite element analysis software ANSYS. Because the concrete filled steel tube arch bridge has the characteristics, such as the components numerous, complex forces, unable to list the of the explicit limit state equation, so use the probability design module of ANSYS (PDS) technology for the perf...

  3. CFD simulations of filling and emptying of hydrogen tanks

    OpenAIRE

    D. Melideo; Baraldi, D.; Acosta-Iborra, B.; Ortiz Cebolla, R.; Moretto, P.

    2016-01-01

    During the filling of hydrogen tanks high temperatures can be generated inside the vessel because of the gas compression while during the emptying low temperatures can be reached because of the gas expansion. The design temperature range goes from 40 C to 85 C. Temperatures outside that range could affect the mechanical properties of the tank materials. CFD analyses of the filling and emptying processes have been performed in the HyTransfer project. To assess the accuracy of the CFD model the...

  4. Simulation of the Fast Filling of Hydrogen Tanks

    OpenAIRE

    HEITSCH Matthias; Baraldi, Daniele; Moretto, Pietro

    2009-01-01

    High pressure storage of hydrogen in tanks is a promising option to provide the necessary fuel for transportation purposes. The fill process of a high-pressure tank should be reasonably short but must be designed to avoid too high temperatures in the tank. The paper describes the fast filling process of hydrogen tanks by simulations based on the Computational Fluid Dynamics (CFD) code CFX. The major result of the simulations is the local temperature distribution in the tank depending on th...

  5. Impact of Viscosity on Filling the Injection Mould Cavity

    Directory of Open Access Journals (Sweden)

    Satin Lukáš

    2016-09-01

    Full Text Available The aim of this paper is to look closer at the rheological properties of plastics and their impact on technology in the plastics processing industry. The paper focuses on the influence of viscosity of the material on filling the mould cavity. Four materials were tested with the settings of process parameters with different viscosity. Using simulation software of Moldex3D, we can see the effect of change in viscosity in the material to be filled.

  6. Gas-Filled Intradural Cyst within the Cauda Equine

    OpenAIRE

    Cho, Hyung-Lea; Lee, Sang-Ho; Kim, Jin-Sung

    2011-01-01

    A case of radicular pain that resulted from a gas-filled intradural cyst in an 80-year-old male is described. Temporary improvement of radicular pain was observed after CT-guided aspiration. However, recurrent radicular pain led to surgical treatment. In this report, the authors document the radiologic and intraoperative features of a gas-filled intradural cyst that migrated into the nerve root, and propose an optimal treatment plan based on a review of the literature.

  7. Method for filling a reactor with a catalyst

    DEFF Research Database (Denmark)

    2013-01-01

    The invention relates to a method for filling a reactor with a catalyst for the carbonylation of carbonylated compounds in the gas phase. According to said method, a SILP catalyst is covered with a filling agent which is liquid under normal conditions and is volatile under carbonylation reaction...... conditions, and a thus-treated catalyst is introduced into the reactor and the reactor is sealed....

  8. Vacuum filling of complex microchannels with liquid metal.

    Science.gov (United States)

    Lin, Yiliang; Gordon, Olivia; Khan, M Rashed; Vasquez, Neyanel; Genzer, Jan; Dickey, Michael D

    2017-09-12

    This paper describes the utilization of vacuum to fill complex microchannels with liquid metal. Microchannels filled with liquid metal are useful as conductors for soft and stretchable electronics, as well as for microfluidic components such as electrodes, antennas, pumps, or heaters. Liquid metals are often injected manually into the inlet of a microchannel using a syringe. Injection can only occur if displaced air in the channels has a pathway to escape, which is usually accomplished using outlets. The positive pressure (relative to atmosphere) needed to inject fluids can also cause leaks or delamination of the channels during injection. Here we show a simple and hands-free method to fill microchannels with liquid metal that addresses these issues. The process begins by covering a single inlet with liquid metal. Placing the entire structure in a vacuum chamber removes the air from the channels and the surrounding elastomer. Restoring atmospheric pressure in the chamber creates a positive pressure differential that pushes the metal into the channels. Experiments and a simple model of the filling process both suggest that the elastomeric channel walls absorb residual air displaced by the metal as it fills the channels. Thus, the metal can fill dead-ends with features as small as several microns and branched structures within seconds without the need for any outlets. The method can also fill completely serpentine microchannels up to a few meters in length. The ability to fill dense and complex geometries with liquid metal in this manner may enable broader application of liquid metals in electronic and microfluidic applications.

  9. Effects of powder flow properties on capsule filling weight uniformity.

    Science.gov (United States)

    Osorio, Juan G; Muzzio, Fernando J

    2013-09-01

    Filling capsules with the right amount of powder ingredients is an important quality parameter. The purpose of this study was to develop effective laboratory methods for characterizing flow properties of pharmaceutical powder blends and correlating such properties to weight variability in filled capsules. The methods used for powder flow characterization were bulk and tapped density, gravitational displacement rheometer (GDR) flow index, Freeman Technology V.4 (FT4) powder rheometer compressibility, FT4 basic flow energy (BFE), and cohesion parameters [cohesion, (C) and flow factor (ffc)] measured in a shear cell also using the FT4. Capsules were filled using an MG2-G140 continuous nozzle dosator capsule-filling machine. Powder flow properties were the most predominant factors affecting the weight and weight variability in the filled capsules. Results showed that the weight variability decreased with increasing bulk and tapped density, ffc and BFE, while the weight variability increased with increasing compressibility, cohesion and GDR flow index. Powder flow properties of the final blends were significantly correlated to the final capsule weight and weight variability of the filled capsules.

  10. Diastolic filling in a physical model of obstructive hypertrophic cardiomyopathy

    Science.gov (United States)

    Schovanec, Joseph; Samaee, Milad; Lai, Hong Kuan; Santhanakrishnan, Arvind

    2015-11-01

    Hypertrophic Cardiomyopathy (HCM) is an inherited heart disease that affects as much as one in 500 individuals, and is the most common cause of sudden death in young athletes. The myocardium becomes abnormally thick in HCM and deforms the internal geometry of the left ventricle (LV). Previous studies have shown that a vortex is formed during diastolic filling, and further that the dilated LV morphology seen in systolic heart failure results in altering the filling vortex from elliptical to spherical shape. We have also previously shown that increasing LV wall stiffness decreases the filling vortex circulation. However, alterations to intraventricular filling fluid dynamics due to an obstructive LV morphology and locally elevated wall stiffness (in the hypertrophied region) have not been previously examined from a mechanistic standpoint. We conducted an experimental study using an idealized HCM physical model and compared the intraventricular flow fields obtained from 2D PIV to a baseline LV physical model with lower wall stiffness and anatomical geometry. The obstruction in the HCM model leads to earlier breakdown of the filling vortex as compared to the anatomical LV. Intraventricular filling in both models under increased heart rates will be discussed.

  11. Fluid dynamics following flow shut-off in bottle filling

    Science.gov (United States)

    Thete, Sumeet; Appathurai, Santosh; Gao, Haijing; Basaran, Osman

    2012-11-01

    Bottle filling is ubiquitous in industry. Examples include filling of bottles with shampoos and cleaners, engine oil and pharmaceuticals. In these examples, fluid flows out of a nozzle to fill bottles in an assembly line. Once the required volume of fluid has flowed out of the nozzle, the flow is shut off. However, an evolving fluid thread or string may remain suspended from the nozzle following flow shut-off and persist. This stringing phenomenon can be detrimental to a bottle filling operation because it can adversely affect line speed and filling accuracy by causing uncertainty in fill volume, product loss and undesirable marring of the bottles' exterior surfaces. The dynamics of stringing are studied numerically primarily by using the 1D, slender-jet approximation of the flow equations. A novel feature entails development and use of a new boundary condition downstream of the nozzle exit to expedite the computations. While the emphasis is on stringing of Newtonian fluids and use of 1D approximations, results will also be presented for situations where (a) the fluids are non-Newtonian and (b) the full set of equations are solved without invoking the 1D approximation. Phase diagrams will be presented that identify conditions for which stringing can be problematic.

  12. Weaving and bonding method to prevent warp and fill distortion

    Science.gov (United States)

    Farley, Gary L. (Inventor)

    1997-01-01

    A method to prevent fiber distortion in textile materials employed in a modified weaving process. In a first embodiment, a tacifier in powder form is applied to the yarn and melted while on the fabric. Cool air is then supplied after the tacifier has melted to expedite the solidification of the tacifier. In a second embodiment, a solution form of a tacifier is used by dissolving the tacifier into a solvent that has a high evaporation rate. The solution is then sprayed onto the fabric or fill yarn as each fill yarn is inserted into a shed of the fabric. A third embodiment applies the tacifier in a liquid form that has not been dissolved in a solvent. That is, the tacifier is melted and is sprayed as a liquid onto the fabric or fill yarn as it is being extracted from a fill yarn spool prior to the fill yarn being inserted into the shed of the fabric. A fourth embodiment employs adhesive yarns contained as an integral part of the warp or fill yarn. Additional tacifier material is not required because a matrix is used as the tacifier. The matrix is then locally melted using heating elements on clamping bars or take-up rollers, is cooled, if necessary, and solidified.

  13. Molecular ferroelectrics: where electronics meet biology.

    Science.gov (United States)

    Li, Jiangyu; Liu, Yuanming; Zhang, Yanhang; Cai, Hong-Ling; Xiong, Ren-Gen

    2013-12-28

    In the last several years, we have witnessed significant advances in molecular ferroelectrics, with the ferroelectric properties of molecular crystals approaching those of barium titanate. In addition, ferroelectricity has been observed in biological systems, filling an important missing link in bioelectric phenomena. In this perspective, we will present short historical notes on ferroelectrics, followed by an overview of the fundamentals of ferroelectricity. The latest developments in molecular ferroelectrics and biological ferroelectricity will then be highlighted, and their implications and potential applications will be discussed. We close by noting molecular ferroelectric as an exciting frontier between electronics and biology, and a number of challenges ahead are also described.

  14. Magnetismo Molecular (Molecular Magentism)

    Energy Technology Data Exchange (ETDEWEB)

    Reis, Mario S [Universidade Federal Fluminense, Brasil; Moreira Dos Santos, Antonio F [ORNL

    2010-07-01

    The new synthesis processes in chemistry open a new world of research, new and surprising materials never before found in nature can now be synthesized and, as a wonderful result, observed a series of physical phenomena never before imagined. Among these are many new materials the molecular magnets, the subject of this book and magnetic properties that are often reflections of the quantum behavior of these materials. Aside from the wonderful experience of exploring something new, the theoretical models that describe the behavior these magnetic materials are, in most cases, soluble analytically, which allows us to know in detail the physical mechanisms governing these materials. Still, the academic interest in parallel this subject, these materials have a number of properties that are promising to be used in technological devices, such as in computers quantum magnetic recording, magnetocaloric effect, spintronics and many other devices. This volume will journey through the world of molecular magnets, from the structural description of these materials to state of the art research.

  15. Morphological study of polymethyl methacrylate microcapsules filled with self-healing agents

    Science.gov (United States)

    Ahangaran, Fatemeh; Hayaty, Mehran; Navarchian, Amir H.

    2017-03-01

    Polymethyl methacrylate (PMMA) microcapsules filled with epoxy prepolymer, 3-aminomethyl-3,5,5-trimethylcyclohexylamine, and pentaerythritol tetrakis (3-mercaptopropionate) as healing agents have been prepared separately through internal phase separation method for self-healing purposes. PMMA with two different molecular weights (M bar1 = 36,000 g/mol and M bar2 = 550,000 g/mol) were used with two types of different emulsifiers (ionic and polymeric) to prepare microcapsules. The morphology of healing agent microcapsules was investigated using field emission scanning electron microscopy (FESEM). It was found that PMMA microcapsules separately filled with epoxy and amine had core-shell morphologies with smooth surfaces. The mercaptan/PMMA particles exhibited core-shell and acorn-shape morphologies. The surface morphology of mercaptan microcapsules changed from holed to plain in different emulsion systems. The spreading coefficient (S) of phases in the prepared emulsion systems were calculated from interfacial tension (σ) and contact angle (θ) measurements. The theoretical equilibrium morphology of PMMA microcapsules was predicted according to spreading coefficient values of phases in emulsion systems. It was also found that the surface morphology of PMMA microcapsules depended strongly on the nature of the core, molecular weight of PMMA, type and concentration of emulsifier.

  16. Interior-filled self-assemblies of tyrosyl bolaamphiphiles regulated by hydrogen bonds.

    Science.gov (United States)

    Kwak, Jinyoung; Nam, Seung Soo; Cho, Junghyun; Sim, Eunji; Lee, Sang-Yup

    2017-04-19

    Bolaamphiphilic molecules with tyrosyl end groups formed interior-filled spherical self-assemblies, which are distinct from the vesicular or tubular structures of other similar peptidic bolaamphiphile assemblies reported in the literature. In this study, the self-assembly mechanism of these tyrosyl bolaamphiphiles was investigated taking into consideration the solvent effects on the molecular interaction forces using molecular modeling. The dissipative particle dynamics simulation of an aqueous tyrosyl bolaamphiphile solution suggested that the interior-filled assemblies were produced by a solvent-regulated assembly of small aggregates of bolaamphiphiles. These small aggregates were generated by hydrophobic interactions at an early stage, and then further assembled to form large spherical assemblies through intermolecular forces, including hydrogen bonds between the intermediate aggregates. Additional experiments and density functional theory calculations based on solvent variations proved that smaller assembled structures could be obtained by disrupting the hydrogen bonds between the intermediates. The assembly mechanism of these peptidic bolaamphiphiles afforded a facile way to create condensed supramolecular structures with controlled sizes.

  17. Filled and empty states of alkanethiol monolayer on Au (1 1 1): Fermi level asymmetry and implications for electron transport

    Science.gov (United States)

    Qi, Yabing; Yaffe, Omer; Tirosh, Einat; Vilan, Ayelet; Cahen, David; Kahn, Antoine

    2011-08-01

    The electronic structure of the prototypical self-assembled monolayer (SAM) system, i.e. alkanethiol molecules on Au, is investigated via ultraviolet and inverse photoemission spectroscopy measurements. The determination of the density of filled and empty states of the system reveals that the metal Fermi level is significantly closer to the lowest unoccupied molecular orbital (LUMO) of the molecules than to their highest occupied molecular orbital (HOMO). The results suggest that charge carrier tunneling is controlled by the LUMO, rather than by the HOMO, in contrast to what is commonly assumed.

  18. Cusp deflection, infraction and fracture in endodontically treated teeth filled with three temporary filling materials (in vitro

    Directory of Open Access Journals (Sweden)

    Ali Eskandarizade

    2015-12-01

    Full Text Available Aim: the aim of this study was to compare cusp deflection, infraction and fracture in teeth filled with three temporary filling materials. Materials & method: Forty five extracted human premolar teeth were chosen. After root canal therapy and mesio-occluso-distal cavity preparation, samples were randomly divided into three groups , each contained 15 teeth and filled with three temporary filling materials: Cavisol (Golchai-Iran, Coltosol F (Coltene,Swiss and Coltene (Ariadent,Iran. Teeth were kept in normal saline at room temperature and every day the intercuspal distance was measured under stereomicroscope for 20 days. Infractions as well as fractures were also noted. Data were analyzed in SPSS 17 using Repeated measurement ANOVA test to evaluate the intercuspal distance and expansion of each sample every day. Results: Intercuspal distance increased in all three groups but was significantly more in Coltosol F group. On the days 10 and 16 two teeth filled with Coltosol F had cusp fracture. Conclusion: Temporary filling materials have hygroscopic expansion and cause cusp deflection which may lead to cusp fracture, so it is recommended to use them in short period of time.

  19. Sacred Space.

    Science.gov (United States)

    Adelstein, Pamela

    2018-01-01

    A space can be sacred, providing those who inhabit a particular space with sense of transcendence-being connected to something greater than oneself. The sacredness may be inherent in the space, as for a religious institution or a serene place outdoors. Alternatively, a space may be made sacred by the people within it and events that occur there. As medical providers, we have the opportunity to create sacred space in our examination rooms and with our patient interactions. This sacred space can be healing to our patients and can bring us providers opportunities for increased connection, joy, and gratitude in our daily work.

  20. Entomophagy and space agriculture

    Science.gov (United States)

    Katayama, N.; Ishikawa, Y.; Takaoki, M.; Yamashita, M.; Nakayama, S.; Kiguchi, K.; Kok, R.; Wada, H.; Mitsuhashi, J.; Space Agriculture Task Force, J.

    Supplying food for human occupants remains one of the primary issues in engineering space habitation Evidently for long-term occupation on a distant planet it is necessary to start agriculture on site Historically humans have consumed a variety of animals and it is required to fill our nutritional need when they live in space Among many candidate group and species of animal to breed in space agriculture insects are of great interest since they have a number of advantages over mammals and other vertebrates or invertebrates About 70-75 of animal species is insects and they play an important role in materials recycle loop of terrestrial biosphere at their various niche For space agriculture we propose several insect species such as the silkworm Bombyx mori the drugstore beetle Stegobium paniceum and the termite Macrotermes subhyalinus Among many advantages these insects do not compete with human in terms of food resources but convert inedible biomass or waste into an edible food source for human The silkworm has been domesticated since 5 000 years ago in China Silk moth has lost capability of flying after its domestication history This feature is advantageous in control of their breeding Silkworm larvae eat specifically mulberry leaves and metamorphose in their cocoon Silk fiber obtained from cocoon can be used to manufacture textile Farming system of the drugstore beetle has been well established Both the drugstore beetle and the termite are capable to convert cellulose or other inedible biomass

  1. Molecular hematology

    National Research Council Canada - National Science Library

    Provan, Drew; Gribben, John

    2010-01-01

    ... The molecular basis of hemophilia, 219 Paul LF Giangrande 4 The genetics of acute myeloid leukemias, 42 Carolyn J Owen & Jude Fitzgibbon 19 The molecular basis of von Willebrand disease, 233 Luciano Baronc...

  2. Exact Filling of Figures with the Derivatives of Smooth Mappings Between Banach Spaces

    Czech Academy of Sciences Publication Activity Database

    Azagra, D.; Fabian, Marián; Jiménez-Sevilla, M.

    2005-01-01

    Roč. 48, č. 4 (2005), s. 481-499 ISSN 0008-4395 R&D Projects: GA AV ČR(CZ) IAA1019003; GA ČR(CZ) GA201/01/1198 Institutional research plan: CEZ:AV0Z10190503 Keywords : n-times smooth * Fréchet smooth * Gateaux smooth bump Subject RIV: BA - General Mathematics Impact factor: 0.316, year: 2005

  3. Rocks Filled with Tiny Spaces Can Turn Green Growing Things Into Stuff We Use Every Day

    Energy Technology Data Exchange (ETDEWEB)

    Nikbin, Nima; Josephson, Tyler; Courtney, Timothy

    2013-07-18

    Representing the Catalysis Center for Energy Innovation (CCEI), this document is one of the entries in the Ten Hundred and One Word Challenge. As part of the challenge, the 46 Energy Frontier Research Centers were invited to represent their science in images, cartoons, photos, words and original paintings, but any descriptions or words could only use the 1000 most commonly used words in the English language, with the addition of one word important to each of the EFRCs and the mission of DOE: energy. The mission of CCEI is to design and characterize novel catalysts for the efficient conversion of the complex molecules comprising biomass into chemicals and fuels.

  4. Use of space-filling curves to select sample locations in natural resource monitoring studies

    Science.gov (United States)

    Andrew Lister; Charles T. Scott

    2009-01-01

    The establishment of several large area monitoring networks over the past few decades has led to increased research into ways to spatially balance sample locations across the landscape. Many of these methods are well documented and have been used in the past with great success. In this paper, we present a method using geographic information systems (GIS) and fractals...

  5. Using a space filling curve approach for the management of dynamic point clouds

    NARCIS (Netherlands)

    Psomadaki, S; van Oosterom, P.J.M.; Tijssen, T.P.M.; Baart, F.

    2016-01-01

    Point cloud usage has increased over the years. The development of low-cost sensors makes it now possible to acquire frequent point cloud measurements on a short time period (day, hour, second). Based on the requirements coming from the coastal monitoring domain, we have developed, implemented and

  6. Illuminating Tradespace Decisions Using Efficient Experimental Space-Filling Designs for the Engineered Resilient System Architecture

    Science.gov (United States)

    2015-06-30

    decision analysis ( MODA ) to help inform the design decision. We use an additive value model that incorporates a composite perspective of multiple...stakeholders and competing objectives. We use the philosophy of value-focused thinking and the mathematics of MODA to arrive at a final design decision...identify a narrow set of viable system alternatives. The set of alternatives are then analyzed using multi-objective decision analysis ( MODA ) models

  7. Color of bulk-fill composite resin restorative materials.

    Science.gov (United States)

    Barutcigil, Çağatay; Barutcigil, Kubilay; Özarslan, Mehmet Mustafa; Dündar, Ayşe; Yilmaz, Burak

    2017-09-28

    To evaluate the color stability of novel bulk-fill composite resins. Color measurements of a nanohybrid composite resin (Z550) and 3 bulk-fill composite resins (BLK, AFX, XTF; n = 45) were performed before polymerization. After polymerization, color measurements were repeated and specimens were immersed in distilled water or red wine, or coffee. Color change [CIEDE2000 (ΔE00 )] was calculated after 24 h, 1 and 3 weeks. Data were analyzed with Kruskal-Wallis, Mann-Whitney U and Wilcoxon tests (α = 0.05). Color changes observed after polymerization were significant for all groups. Color changes observed in distilled water for Z550 and AFX were significant. Color changes after stored in red wine and coffee were significant for all groups. Bulk-fill composite resin color change increased over time for all groups in red wine and coffee (P composite resin and bulk-fill composite resins. AFX had the highest color change in distilled water. The color of tested bulk-fill composite resins significantly changed after immersion in beverages and over time. Color change observed with the nanohybrid composite resin after 1 week was stable. Clinicians should keep in mind that tested composite resins may change color when exposed to water and significantly change color immediately after they are polymerized. In addition, the color change continues over time should the patient is a coffee and/or red wine consumer. © 2017 Wiley Periodicals, Inc.

  8. Elution of monomer from different bulk fill dental composite resins.

    Science.gov (United States)

    Cebe, Mehmet Ata; Cebe, Fatma; Cengiz, Mehmet Fatih; Cetin, Ali Rıza; Arpag, Osman Fatih; Ozturk, Bora

    2015-07-01

    The purpose of this study was to evaluate the elution of Bis-GMA, TEGDMA, HEMA, and Bis-EMA monomers from six bulk fill composite resins over four different time periods, using HPLC. Six different composite resin materials were used in the present study: Tetric Evo Ceram Bulk Fill (Ivoclar Vivadent, Amherst, NY), X-tra Fill (VOCO, Cuxhaven, Germany), Sonic Fill (Kerr, Orange, CA, USA), Filtek Bulk Fill (3M ESPE Dental Product, St. Paul, MN), SDR (Dentsply, Konstanz, Germany), EQUIA (GC America INC, Alsip, IL). The samples (4mm thickness, 5mm diameter) were prepared and polymerized for 20s with a light emitted diode unit. After fabrication, each sample was immediately immersed in 75wt% ethanol/water solution used as extraction fluid and stored in the amber colored bottles at room temperature. Ethanol/water samples were taken (0.5mL) at predefined time intervals:10m (T1), 1h (T2), 24h (T3) and 30 days (T4). These samples were analyzed by HPLC. The obtained data were analyzed with one-way ANOVA and Tukey HSD at significance level of presins in all time periods and the amount of eluted monomers was increased with time. Copyright © 2015 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  9. The Space House TM : Space Technologies in Architectural Design

    Science.gov (United States)

    Gampe, F.; Raitt, D.

    2002-01-01

    The word "space" has always been associated with and had a profound impact upon architectural design. Until relatively recently, however, the term has been used in a different sense to that understood by the aerospace community - for them, space was less abstract, more concrete and used in the context of space flight and space exploration, rather than, say, an empty area or space requiring to be filled by furniture. However, the two senses of the word space have now converged to some extent. Interior designers and architects have been involved in designing the interior of Skylab, the structure of the International Space Station, and futuristic space hotels. Today, architects are designing, and builders are building, houses, offices and other structures which incorporate a plethora of new technologies, materials and production processes in an effort not only to introduce innovative and adventurous ideas but also in an attempt to address environmental and social issues. Foremost among these new technologies and materials being considered today are those that have been developed for and by the space industry. This paper examines some of these space technologies, such as energy efficient solar cells, durable plastics, air and water filtration techniques, which have been adapted to both provide power while reducing energy consumption, conserve resources and so on. Several of these technologies have now been employed by the European Space Agency to develop a Space House TM - the first of its kind, which will be deployed not so much on planets like Mars, but rather here on Earth. The Space House TM, which exhibits many innovative features such as high strength light-weight carbon composites, active noise-damped, (glass and plastic) windows, low-cost solar arrays and latent heat storage, air and water purification systems will be described.

  10. Physical and numerical simulations of fluid-filled cavities in a creeping material

    Energy Technology Data Exchange (ETDEWEB)

    Preece, D.S.; Sutherland, H.J.

    1986-05-01

    Centrifuge creep experiments have been performed on six models of fluid-filled cylindrical cavities in a cylindrical block of the modeling material plasticine. Three of the experiments treated a single cavity on the axis of the plasticine cylinder. The other three experiments each treated an array of four cavities with three cavities symmetrically arranged around one central cavity. The three multi-cavity models differed in the spacing between the central and satellite cavities. The experiments were designed to physically model petroleum-filled caverns leached in rock salt. The experiments were performed for several reasons. First, plasticine is a creeping material which has a mathematical formulation similar to rock salt. Finite element computer programs that include material models for creep have been exercised by performing finite element analyses of the experiments using the plasticine creep model and comparing numerical and experimental results. Both two- and three-dimensional finite element analyses were performed. Second, the multi-cavity experiments were designed to gain an understanding of the behavior of arrays of cavities, specifically, how spacing between cavities influences their creep response. Three-dimensional finite element simulations of the multi-cavity experiments acted as a validation excerise for the code and provided information such as stress distribution that could not be measured experimentally. Third, information obtained about the interaction of cavities in plasticine can also be applied to cavities in rock salt.

  11. Modeling and Analysis of Chill and Fill Processes for the EDU Tank

    Science.gov (United States)

    Hedayat, A.; Cartagena, W.; Majumdar, A. K.; Leclair, A. C.

    2015-01-01

    NASA's future missions may require long-term storage and transfer of cryogenic propellants. The Engineering Development Unit (EDU), a NASA in-house effort supported by both Marshall Space Flight Center (MSFC) and Glenn Research Center (GRC), is a Cryogenic Fluid Management (CFM) test article that primarily serves as a manufacturing pathfinder and a risk reduction task for a future CFM payload. The EDU test article, comprises a flight like tank, internal components, insulation, and attachment struts. The EDU is designed to perform integrated passive thermal control performance testing with liquid hydrogen in a space-like vacuum environment. A series of tests, with liquid hydrogen as a testing fluid, was conducted at Test Stand 300 at MSFC during summer of 2014. The objective of this effort was to develop a thermal/fluid model for evaluating the thermodynamic behavior of the EDU tank during the chill and fill processes. Generalized Fluid System Simulation Program (GFSSP), an MSFC in-house general-purpose computer program for flow network analysis, was utilized to model and simulate the chill and fill portion of the testing. The model contained the liquid hydrogen supply source, feed system, EDU tank, and vent system. The modeling description and comparison of model predictions with the test data will be presented in the final paper.

  12. Thermodynamics of fluid conduction through hydrophobic channel of carbon nanotubes: The exciting force for filling of nanotubes with polar and nonpolar fluids

    Science.gov (United States)

    Sahu, Pooja; Ali, Sk. M.; Shenoy, K. T.

    2015-02-01

    Thermodynamic properties of the fluid in the hydrophobic pores of nanotubes are known to be different not only from the bulk phase but also from other conventional confinements. Here, we use a recently developed theoretical scheme of "two phase thermodynamic (2PT)" model to understand the driving forces inclined to spontaneous filling of carbon nanotubes (CNTs) with polar (water) and nonpolar (methane) fluids. The CNT confinement is found to be energetically favorable for both water and methane, leading to their spontaneous filling inside CNT(6,6). For both the systems, the free energy of transfer from bulk to CNT confinement is favored by the increased entropy (TΔS), i.e., increased translational entropy and increased rotational entropy, which were found to be sufficiently high to conquer the unfavorable increase in enthalpy (ΔE) when they are transferred inside CNT. To the best of our knowledge, this is the first time when it has been established that the increase in translational entropy during confinement in CNT(6,6) is not unique to water-like H bonding fluid but is also observed in case of nonpolar fluids such as methane. The thermodynamic results are explained in terms of density, structural rigidity, and transport of fluid molecules inside CNT. The faster diffusion of methane over water in bulk phase is found to be reversed during the confinement in CNT(6,6). Studies reveal that though hydrogen bonding plays an important role in transport of water through CNT, but it is not the solitary driving factor, as the nonpolar fluids, which do not have any hydrogen bond formation capacity can go inside CNT and also can flow through it. The associated driving force for filling and transport of water and methane is enhanced translational and rotational entropies, which are attributed mainly by the strong correlation between confined fluid molecules and availability of more free space for rotation of molecule, i.e., lower density of fluid inside CNT due to their

  13. Space Curves

    CERN Document Server

    Peskine, Christian; Sernesi, Edoardo

    1987-01-01

    The main topics of the conference on "Curves in Projective Space" were good and bad families of projective curves, postulation of projective space curves and classical problems in enumerative geometry.

  14. Molecular Dynamics Simulations of Silica-Filled Copolymers with Variable Sequence for Applications in Tire Treads

    Science.gov (United States)

    Trazkovich, Alex J.; Hall, Lisa M.

    We simulate a simple nanocomposite relevant to tire tread compounds consisting of a single spherical nanoparticle surrounded by coarse-grained polymer chains. The polymers are composed of two different monomer types, which have different interaction strengths with the nanoparticle. The monomer sequence can be varied to model different copolymer configurations. We study the polymer end-to-end vector autocorrelation functions to obtain relaxation times of adsorbed and bulk polymer, showing how the interphase is affected by the polymer type and the monomer-nanoparticle interaction strengths. An understanding of the effect of copolymer sequence on the range of the polymer interphase and the magnitude of the effect on chain dynamics is critical to tire tread material design since the primary polymer component of modern tire tread is styrene-butadiene rubber (SBR) copolymer, which may be synthesized in primarily random or in various blocky copolymer configurations. Macromolecular adsorption to and desorption from filler surfaces has a significant effect on hysteresis, and in tire treads, hysteresis must be controlled to optimize the tradeoff between traction and rolling resistance. Superior tire tread materials must have high hysteresis under the operating conditions of traction while maintaining low hysteresis under the operating conditions of rolling resistance. An opportunity exists to control hysteresis through the use of SBR with specific monomer sequences.

  15. Space Microbiology

    OpenAIRE

    Horneck, Gerda; Klaus, David M.; Mancinelli, Rocco L

    2010-01-01

    Summary: The responses of microorganisms (viruses, bacterial cells, bacterial and fungal spores, and lichens) to selected factors of space (microgravity, galactic cosmic radiation, solar UV radiation, and space vacuum) were determined in space and laboratory simulation experiments. In general, microorganisms tend to thrive in the space flight environment in terms of enhanced growth parameters and a demonstrated ability to proliferate in the presence of normally inhibitory levels of antibiotic...

  16. Gap filling strategies for long term energy flux data sets

    DEFF Research Database (Denmark)

    Falge, E.; Baldocchi, D.; Olson, R.

    2001-01-01

    At present a network of over 100 field sites are measuring carbon dioxide, water vapor and sensible heat fluxes between the biosphere and atmosphere, on a nearly continuous basis. Gaps in the long term measurements of evaporation and sensible heat flux must be filled before these data can be used...... for hydrological and meteorological applications. We adapted methods of gap filling for NEE (net ecosystem exchange of carbon) to energy fluxes and applied them to data sets available from the EUROFLUX and AmeriFlux eddy covariance databases. The average data coverage for the sites selected was 69% and 75......% for latent heat (lambdaE) and sensible heat (H). The methods were based on mean diurnal variations (half-hourly binned means of fluxes based on previous and subsequent days, MDV) and look-up tables for fluxes during assorted meteorological conditions (LookUp), and the impact of different gap filling methods...

  17. Increasing fill volume reduces cardiac performance in peritoneal dialysis

    DEFF Research Database (Denmark)

    Ivarsen, Per; Povlsen, Johan V; Jensen, Jens Dam

    2007-01-01

    the demand on the heart even during normal daily activities. METHODS: Fifteen stable PD patients were included in this randomized, controlled, open-label crossover study. After drainage, we measured blood pressure, pulse rate and cardiac output (CO) after 30 min in the supine position. The measurements were...... arterial blood pressure remained unchanged. In the upright position, SV and CO decreased and total peripheral systemic resistance increased. Pulse rate and mean arterial blood pressure were unchanged independent of fill volume when compared with the drained situation. During postural change, no significant...... repeated 5 min later in an upright position. Subsequently, following fill, the measurements were repeated after 30 min in the supine and 5 min later in the upright position. The two procedures were repeated twice. The fill was either 2 l or 3 l of dialysate. CO was measured with a non-invasive device based...

  18. Koszul spaces

    DEFF Research Database (Denmark)

    Berglund, Alexander

    2014-01-01

    We prove that a nilpotent space is both formal and coformal if and only if it is rationally homotopy equivalent to the derived spatial realization of a graded commutative Koszul algebra. We call such spaces Koszul spaces and show that the rational homotopy groups and the rational homology of iter...

  19. Space administration

    OpenAIRE

    Worthington, Scott; Worthington, Scott

    2015-01-01

    My dissertation consists of two parts. The larger portion is an hour-long piece for double bass, electronics, and projected text called Space Administration. The second portion, this essay, discusses my musical background leading up to Space Administration, details of the composition itself, and what new directions I see in my work that in part stem from creating the piece Space Administration

  20. The biocompatibility of non-amalgam dental filling materials.

    Science.gov (United States)

    Schmalz, G

    1998-04-01

    Non-amalgam filling materials may release substances which have been shown to be toxic in cytotoxicity tests and implantation studies. However, results from systemic toxicity tests do not indicate any unacceptable risk to the patient's general health, but data for non-amalgam dental filling materials are scarce in comparison to amalgam. Although estrogen-like effects of one fissure sealant have been claimed, no conclusions can be drawn at present for the patient from these in vitro data because of the limitation of the test methods and materials used. Some components of composite resins/dentin adhesives and a resin-modified glass ionomer cement were mutagenic mainly in in vitro tests. Due to the limitations of the test systems and the comparatively high concentrations needed to elicit the reactions, no unacceptable risk can yet be derived from those data for the patient. However, a no-touch technique is recommended for the dental personnel. As with amalgam, local reactions of the pulp are not expected with alternative filling materials, if the pulp tissue is not exposed and if bacterial penetration is avoided. The latter requirement is still difficult to fulfill, especially for composite resin systems and related materials in posterior teeth situations. Slight gingival reactions to alternative filling materials and to amalgams are mainly attributed to plaque accumulation. From all these data it can be concluded that, for the time being, it is not possible to rank dental filling materials in respect to their biocompatibility, and it is evident that biocompatibility must be considered to the same extent for both amalgams and commonly used or recommended alternative filling materials.

  1. Effect of Different Filling Materials in Anammox Bacteria Enrichment

    Directory of Open Access Journals (Sweden)

    Dilek ÖZGÜN

    2012-12-01

    Full Text Available Purpose: Anaerobic ammonium oxidation (Anammox is a process that ammonium as electron donor is oxidized to nitrogen gas using nitrite as electron acceptor. Compared to conventional nitrification-denitrification processes, this process is used less oxygen and no organic material (methanol, glucose. However, the slow growth rate of Anammox bacteria (11-30 days is disadvantages. Therefore, batch reactors have been carried out in these bacteria enrichment. In this study continuously operated upflow anaerobic sludge reactor (UASB using different filling materials disposing of sensitive and slow-growing Anammox bacteria out of the system is purposed. Design and Methods: System is operated up-flow column reactor at 2 days hydraulic retention time (HRT in 45 days. In this study, ceramic stones and Linpor filling material are used. Using synthetic wastewater containing ammonium and nitrite, Ar/CO2 anaerobic conditions (95/5% supplied with gas. System is operated at a temperature 253 C in UASB. Temperature, pH, ammonia-nitrogen and nitrite nitrogen are measured. Results: Both filling material reactors are operated in 45 days. Ceramic stones filling reactor is observed quickly reaches 90% were used reactor ammonium removal. The ammonium nitrogen removal was slower in Linpor filling materials reactor. Nitrite removal is reached up to 90% in both the reactor. When compared to the stoichiometric equation in Linpor was composed of large amounts of nitrate. At the end of 25 days the results were similar to ceramic stone filling reactor with Linpor filling material reactors. Conclusions and Original Value: Anammox process as from nitrogen removal processes was discovered in 1995. Anammox bacteria that make up this process due to very low growth rates of microbial bacteria in the system must be kept in the system. Most of the studies in the literature, these bacteria enrichment stage is started instead of a continuous batch reactor system. In this study

  2. Les mobiles de participation des filles au football et autonomisation ...

    African Journals Online (AJOL)

    Cette étude vise à connaître les mobiles qui conditionnent les filles béninoises à pratiquer le football et à les analyser pour développer l'autonomisation des filles en rapport avec les défis du millénaire. Pour ce faire 108 joueuses, dont la moyenne d'âge est de 17 ans, réparties dans 9 équipes parmi les 17 équipes que ...

  3. [Animal experimental tests of a new filling material (Isocap)].

    Science.gov (United States)

    Riethe, P; Rotgans, J; Schmalz, G

    1978-09-01

    An experimental investigation with animals (Rhesus monkeys) concerning pulp tolerance to two premeasured dosages of calcium hydroxide cement (Reocap and Reocap-E) as well as a pre-measured dosage of filling material (Isocap) in an injection capsule was carried out (78 class V cavities). As with the negative controls, a very slight reaction, or none at all, developed in response to the two calcium hydroxide cements and the new filling material, with and without application of capping material. When five other accidentally exposed pulpae were dissected, direct capping under the corresponding preconditions (punctate exposed pulpa, longer storage period for calcium hydroxide cement) showed the characteristic formation of reparative dentin.

  4. Gap-filling strategies for annual VOC flux data sets.

    Science.gov (United States)

    Bamberger, I; Hörtnagl, L; Walser, M; Hansel, A; Wohlfahrt, G

    2013-11-01

    Up to now the limited knowledge about the exchange of volatile organic compounds (VOCs) between the biosphere and the atmosphere is one of the factors which hinders more accurate climate predictions. Complete long-term flux data sets of several VOCs to quantify the annual exchange and validate recent VOC models are basically not available. In combination with long-term VOC flux measurements the application of gap-filling routines is inevitable in order to replace missing data and make an important step towards a better understanding of the VOC ecosystem-atmosphere exchange on longer time scales. We performed VOC flux measurements above a mountain meadow in Austria during two complete growing seasons (from snowmelt in spring to snow reestablishment in late autumn) and used this data set to test the performance of four different gap-filling routines, mean diurnal variation (MDV), mean gliding window (MGW), look up tables (LUT) and linear interpolation (LIP), in terms of their ability to replace missing flux data in order to obtain reliable VOC sums. According to our findings the MDV routine was outstanding with regard to the minimization of the gap-filling error for both years and all quantified VOCs. The other gap-filling routines, which performed gap-filling on 24 h average values, introduced considerably larger uncertainties. The error which was introduced by the application of the different filling routines increased linearly with the number of data gaps. Although average VOC fluxes measured during the winter period (complete snow coverage) were close to zero, these were highly variable and the filling of the winter period resulted in considerably higher uncertainties compared to the application of gap-filling during the measurement period. The annual patterns of the overall cumulative fluxes for the quantified VOCs showed a completely different behavior in 2009, which was an exceptional year due to the occurrence of a severe hailstorm, compared to 2011. Methanol

  5. [Laboratory evaluation of the efficiency of dental root channel filling].

    Science.gov (United States)

    Makeeva, I M; Poiurovskaia, I Ia; Ramazanova, A E; Denisova, L A

    2004-01-01

    Adhesive strength of gutta-percha stems connection to the root channel walls was evaluated. The pressure on dental root channel walls during tooth filling by the lateral condensation method was evaluated. The study was carried out on an Instron device by the pulling out method. The study showed that for stems Nos. 15-30 the retention strength in the root channel was about 2-fold higher than for stems Nos. 35-45. The results indicate that the value of stem pressure on root channel walls during tooth filling by the lateral condensation method can be considered critical with regard to the strength of the dental root proper.

  6. Pengembangan Modul Autentikasi Captcha Berbasis Gambar dengan Algoritma Flood Fill

    Directory of Open Access Journals (Sweden)

    Jessika Wandapranata

    2017-04-01

    Full Text Available Captcha merupakan salah satu cara memberikan akses internet yang aman dari serangan bots. Captcha (Completely Automated Public Turing Test To Tell Computers and Humans Apart merupakan sebuah challenge response test yang digunakan untuk membedakan manusia dan robot (bots. Namun seiring perkembangan waktu, telah berkembang serangan otomatis yang berhasil membobol beberapa jenis Captcha. Oleh karena itu, pada penelitian ini dikembangkan Captcha berbasis gambar dengan metode autentikasi yang berbeda. Autentikasi Captcha dilakukan dengan menerapkan algoritma Flood Fill. Dalam implementasinya, dapat disimpulkan bahwa algoritma Flood Fill berhasil diimplementasikan pada autentikasi modul Capthca berbasis gambar. Telah dilakukan juga pengumpulan sampel data dan didapatkan hasil 77.4% responden merekomendasikan penggunaan Captcha yang telah dibangun.

  7. SPECIFICATION OF ENGINEERING PROPOSALS FOR FOUNDATIONS ON COMPACTED FILLS

    Directory of Open Access Journals (Sweden)

    V.A. Kovalev

    2017-06-01

    Full Text Available In the present article engineering proposals (operation schedules for foundations on compacted fills, aimed to improve their bearing capability, labour intensity (energy requirement decrement, primarily in a rugged geological profile including thixotropic, heaving (swelling, collapsible, filled and other similar types of soils, have been outlined. The main technological processes applied to foundation works in tamped ditches, with the use of drop-in blocks, cast-in-situ and displacement stilts in drilled wells, including short stilts with rigging on a crane-type excavator of improved design have been researched.

  8. Plasma-filled diode based on the coaxial gun

    Science.gov (United States)

    Zherlitsyn, A. A.; Kovalchuk, B. M.; Pedin, N. N.

    2012-10-01

    The paper presents the results of studies of a coaxial gun for a plasma-filled electron diode. Effects of the discharge channel diameter and gun current on characteristics of the plasma and pulse generated in the diode were investigated. The electron beam with maximum energy of ≥1 MeV at the current of ≈100 kA was obtained in the experiments with a plasma-filled diode. The energy of ≈5 kJ with the peak power of ≥100 GW dissipated in the diode.

  9. Survey on Material Used to Fill Wooden Objects During Conservation

    Directory of Open Access Journals (Sweden)

    Kate Fulcher

    2014-07-01

    Full Text Available The data here described are the results of a survey sent to conservators to discover the range of materials being using to fill gaps in wooden objects, and to assess how popular hydroxypropyl cellulose and paper pulp were in regards to this. The survey was created using Survey Monkey, a free online survey tool. The complete dataset is available from UCL Discovery in Excel and CSV format. It is hoped that these survey results can be used by conservators to inform their work on wooden objects and inspire experimental work that will demonstrate the suitability of different materials for the purpose of filling wood.

  10. Patterning of stomata in the moss Funaria: a simple way to space guard cells.

    Science.gov (United States)

    Merced, Amelia; Renzaglia, Karen S

    2016-05-01

    Studies on stomatal development and the molecular mechanisms controlling patterning have provided new insights into cell signalling, cell fate determination and the evolution of these processes in plants. To fill a major gap in knowledge of stomatal patterning, this study describes the pattern of cell divisions that give rise to stomata and the underlying anatomical changes that occur during sporophyte development in the moss Funaria. Developing sporophytes at different stages were examined using light, fluorescence and electron microscopy; immunogold labelling was used to investigate the presence of pectin in the newly formed cavities. Substomatal cavities are liquid-filled when formed and drying of spaces is synchronous with pore opening and capsule expansion. Stomata in mosses do not develop from a self-generating meristemoid as in Arabidopsis, but instead they originate from a protodermal cell that differentiates directly into a guard mother cell. Epidermal cells develop from protodermal or other epidermal cells, i.e. there are no stomatal lineage ground cells. Development of stomata in moss occurs by differentiation of guard mother cells arranged in files and spaced away from each other, and epidermal cells that continue to divide after stomata are formed. This research provides evidence for a less elaborated but effective mechanism for stomata spacing in plants, and we hypothesize that this operates by using some of the same core molecular signalling mechanism as angiosperms. © The Author 2016. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  11. Workstation Designs for a Cis-Lunar Deep Space Habitat

    Science.gov (United States)

    Howe, A. Scott

    2014-01-01

    Using the International Standard Payload Rack (ISPR) system, a suite of workstations required for deep space missions have been proposed to fill out habitation functions in an International Space Station (ISS) derived Cis-lunar Deep Space Habitat. This paper introduces the functional layout of the Cis-lunar habitat design, and describes conceptual designs for modular deployable work surfaces, General Maintenance Workstation (GMWS), In-Space Manufacturing Workstation (ISMW), Intra-Vehicular Activity Telerobotics Work Station (IVA-TRWS), and Galley / Wardroom.

  12. THz Instruments for Space

    OpenAIRE

    Siegel, Peter H.

    2007-01-01

    Terahertz technology has been driven largely by applications in astronomy and space science. For more than three decades cosmochemists, molecular spectroscopists, astrophysicists, and Earth and planetary scientists have used submillimeter-wave or terahertz sensors to identify, catalog and map lightweight gases, atoms and molecules in Earth and planetary atmospheres, in regions of interstellar dust and star formation, and in new and old galaxies, back to the earliest days of the universe, from...

  13. Design spaces

    DEFF Research Database (Denmark)

    2005-01-01

    Digital technologies and media are becoming increasingly embodied and entangled in the spaces and places at work and at home. However, our material environment is more than a geometric abstractions of space: it contains familiar places, social arenas for human action. For designers, the integration...... of digital technology with space poses new challenges that call for new approaches. Creative alternatives to traditional systems methodologies are called for when designers use digital media to create new possibilities for action in space. Design Spaces explores how design and media art can provide creative...... alternatives for integrating digital technology with space. Connecting practical design work with conceptual development and theorizing, art with technology, and usesr-centered methods with social sciences, Design Spaces provides a useful research paradigm for designing ubiquitous computing. This book...

  14. Novel use of an air-filled breast prosthesis to allow radiotherapy to recurrent colonic cancer.

    LENUS (Irish Health Repository)

    O'Duffy, F

    2012-02-01

    AiM: The authors present the novel and successful use of an air-filled breast prosthesis for extra pelvic exclusion of small bowel to facilitate adjuvant radiotherapy following resection of recurrent adenocarcinoma of the ascending bowel. The therapeutic use of radiotherapy in colon cancer can cause acute or chronic radiation enteropathy. Mobile small bowel can be sequestered in \\'dead space\\' or by adhesions exposing it to adjuvant radiotherapy. A variety of pelvic partitioning methods have been described to exclude bowel from radiation fields using both native and prosthetic materials. METHOD: In this case a 68 year old presented with ascending colon adenocarcinoma invading the peritoneum and underwent en bloc peritoneal resection. Thirty-seven months later surveillance CT identified a local recurrence. Subsequent resection resulted in a large iliacus muscle defect which would sequester small bowel loops thus exposing the patient to radiation enteropathy. The lateral position of the defect precluded the use of traditional pelvic partitioning methods which would be unlikely to remain in place long enough to allow radiotherapy. A lightweight air-filled breast prosthesis (Allergan 133 FV 750 cms) secured in place with an omentoplasty was used to fill the defect. RESULTS: Following well tolerated radiotherapy the prosthesis was deflated under ultrasound guidance and removed via a 7-cm transverse incision above the right iliac crest. The patient is disease free 18 months later with no evidence of treatment related morbidity. CONCLUSION: The use of a malleable air-filled prosthesis for pelvic partitioning allows specific tailoring of the prosthesis size and shape for individual patient defects. It is also lightweight enough to be secured in place using an omentoplasty to prevent movement related prosthesis migration. In the absence of adequate omentum a mesh sling may be considered to allow fixation. In this case the anatomy of the prosthesis position allowed for its

  15. Accelerated weathering of natural fiber-filled polyethylene composites

    Science.gov (United States)

    Thomas Lundin; Steven M. Cramer; Robert H. Falk; Colin. Felton

    2004-01-01

    The resistance of natural fiber-filled high-density polyethylene composite specimens to ultraviolet- (UV) and moisture-induced degradation was evaluated by measuring changes to flexural properties. High-density polyethylene (HDPE) served as the polymer matrix for four formulations: two formulations without fiber filler and two formulations one containing wood flour and...

  16. biodegradation and moisture uptake modified starch-filled linear low

    African Journals Online (AJOL)

    CHEMISTRY

    BIODEGRADATION AND MOISTURE UPTAKE MODIFIED. STARCH-FILLED LINEAR LOW-DENSITY POLYETHYLENE. (LLDPE) COMPOSITES. 1Gumel, S. M., 2M. K. Yakubu and 3Mohammed, A.D.. 1Department of Pure and Industrial Chemistry, Bayero University Kano. 2Department of Textile Science and Technology, ...

  17. Methodology for teaching facial filling with hyaluronic acid.

    Science.gov (United States)

    De Oliveira Ruiz, R; Laruccia, M M; Gerenutti, M

    2014-01-01

    This paper shows the importance of the methodization in teaching facial dermal filling on the training of physicians who intend to work or are already working in the area of facial aesthetics. The methodology is based on the procedures performed in Iz Clinic of Plastic Surgery from 2007 to 2010, where the results of the use of dermal filling products were observed. We chose the hyaluronic acid for the methodization of education. Even being a safe procedure, the dermal filling needs to be done by trained professionals because some complications may occur. The theoretical discussion of facial anatomy, physiology and classification of aging, rheological characteristics of products and application techniques underpin the practical part, in which the live demo or supervision of the procedure is performed. The idealization of classes, both theoretical and practical, proposed in this work proved to be of great value in teaching physicians. The success of this method can be seen from the results achieved by students and by observing the drop in reports of adverse effects. After learning the techniques of facial dermal filling with products based on hyaluronic acid, a doctor may perform this therapy with other fillers, with harmonious results.

  18. 7 CFR 2902.20 - Fluid-filled transformers.

    Science.gov (United States)

    2010-01-01

    ... transformers. Electric power transformers that are designed to utilize a synthetic ester-based dielectric (non... transformers. Electric power transformers that are designed to utilize a vegetable oil-based dielectric (non... 7 Agriculture 15 2010-01-01 2010-01-01 false Fluid-filled transformers. 2902.20 Section 2902.20...

  19. Laboratory tests on fungal resistance of wood filled polyethylene composites

    Science.gov (United States)

    Craig M. Clemons; Rebecca E. Ibach

    2002-01-01

    A standard method for determining the durability of structural wood was modified for testing the fungal resistance of composites made from high density polyethylene filled with 50% wood flour. Moisture content, mechanical properties, and weight loss were measured over 12 weeks exposure to brown-and white-rot fungi. Mechanical properties were decreased, but irreversible...

  20. The intraventricular filling vortex under heightened aortic blood pressure

    Science.gov (United States)

    Nelsen, Nicholas; Gaddam, Manikantam; Santhanakrishnan, Arvind

    2017-11-01

    Hypertension, or high aortic blood pressure, can induce structural changes in the left ventricle (LV) such as concentric hypertrophy. Previous studies have identified that the intraventricular filling vortex serves as an effective means of blood transport during diastolic filling. However, a fundamental understanding of how hypertension affects this vortex is unavailable. This knowledge can be useful for improving diagnosis and treatment of related heart disease conditions, including hypertensive heart failure. In this experimental study, we hypothesized that the circulation of the filling vortex would diminish with increased aortic pressure. Using a LV physical model within a left heart simulator, we performed hemodynamic measurements to acquire pressure and volumetric inflow profiles and 2D particle image velocimetry to visualize the intraventricular flow fields. Peak aortic pressures of 120 mm Hg, 140 mm Hg, and 160 mm Hg were each tested at heart rates of 70, 100, and 110 beats per minute, under: 1) reduced ejection fraction (EF), and 2) constant EF. Our results indicate that peak vortex circulation is reduced under elevated aortic pressures. Hemodynamics and characteristics of the intraventricular filling vortex in all examined experimental cases will be presented.

  1. The Effects of Iron Filling On Some Mechanical and Physical ...

    African Journals Online (AJOL)

    acer

    rape straw, reed, sunflower, seek husks, and groundnut shells, such as raw material for particleboards was studied. ... the word are used in the interests of economy, part of the expensive plastic being replaced by a cheaper material. ... Iron and steel filled plastics have many electrical uses, most of which make use of the ...

  2. a preliminary assessment of groundwater samples around a filling ...

    African Journals Online (AJOL)

    Home

    This paper is a preliminary assessment of groundwater samples around a filling station in Diobu area of Port. Harcourt for four years at ... while Ec, TDS, Cl, Fe, TSS, salinity, hardness may be due to saltwater intrusion from the sea. The anthropogenic .... soil, Bm is the background concentration (value) of metal, either taken ...

  3. Improved mold release for filled-silicone compounds

    Science.gov (United States)

    Accountius, O. E.

    1973-01-01

    Ceramic and filled-plastic materials used for fabrication of tiles are relatively brittle and easily break as they are being removed from molds. Dusting mold surfaces with commercially available glass microspheres provides mold release superior to existing spray releases. Glass-microsphere dusting also permits removal of uncured tile which has very little strength.

  4. Equations for the Filled Inelastic Membrane: A More General Derivation

    Science.gov (United States)

    Deakin, Michael A. B.

    2011-01-01

    An earlier paper discussed the case of a flexible but inextensible membrane filled to capacity with incompressible fluid. It was found that the resulting shape satisfies a set of three simultaneous partial differential equations. This article gives a more general derivation of these equations and shows their form in an interesting special case.

  5. Biopharmaceutical formulations for pre-filled delivery devices.

    Science.gov (United States)

    Jezek, Jan; Darton, Nicholas J; Derham, Barry K; Royle, Nikki; Simpson, Iain

    2013-06-01

    Pre-filled syringes are becoming an increasingly popular format for delivering biotherapeutics conveniently and cost effectively. The device design and stable liquid formulations required to enable this pre-filled syringe format are technically challenging. In choosing the materials and process conditions to fabricate the syringe unit, their compatibility with the biotherapeutic needs to be carefully assessed. The biothereaputic stability demanded for the production of syringe-compatible low-viscosity liquid solutions requires critical excipient choices to be made. The purpose of this review is to discuss key issues related to the stability aspects of biotherapeutics in pre-filled devices. This includes effects on both physical and chemical stability due to a number of stress conditions the product is subjected to, as well as interactions with the packaging system. Particular attention is paid to the control of stability by formulation. We anticipate that there will be a significant move towards polymer primary packaging for most drugs in the longer term. The timescales for this will depend on a number of factors and hence will be hard to predict. Formulation will play a critical role in developing successful products in the pre-filled syringe format, particularly with the trend towards concentrated biotherapeutics. Development of novel, smart formulation technologies will, therefore, be increasingly important.

  6. Process and part filling control in micro injection molding

    DEFF Research Database (Denmark)

    Tosello, Guido; Hansen, Hans Nørgaard; Schoth, Andreas

    2008-01-01

    The influence of process parameters on μ-injection molding (μIM) and on μ-injection molded parts has been investigated using Design of Experiments. A mold with a sensor applied at injection location was used to monitor actual injection pressure and to determine the cavity filling time. Flow markers...

  7. geophysical investigation of abandoned back-filled railway line

    African Journals Online (AJOL)

    obtained from the traverse were plotted against the mid-point of electrode separation using least-squares inversion algorithm. Pockets of low resistivity region were obtained from the inverted sections with resistivity values ranging from 77 Ω-m to ˂400 Ω-m. The suspected back-filled earth materials were suspected to be ...

  8. Prevalence of low back pain among filling stations attendants in ...

    African Journals Online (AJOL)

    Low back pain has been found to be common among workers of some certain industries and occupation, however little is known about its prevalence among filling stations attendants who are perceived to belong to the group that are exposed to high occupational risk. This study was designed to determine the prevalence ...

  9. Evaluation of ac conductivity behaviour of graphite filled ...

    Indian Academy of Sciences (India)

    Composites of epoxy resin having different amounts of graphite particles have been prepared by solution casting method. Temperature dependence of dielectric constant, tan and a.c. conductivity was measured in the frequency range, 1–20 kHz, temperature range, 40–180°C for 0.99, 1.96 and 2.91 wt% graphite filled ...

  10. Behavior of rigid and flexible culvert pipes under deep fill.

    Science.gov (United States)

    1977-01-01

    Along a section of Interstate 77 in Carroll County, in the mountainous region of southwestern Virginia, it was necessary to construct a fill approximately 258 ft (78 m) deep. The flow of a mountain stream had to be carried through this massive embank...

  11. Simplified analysis of filled steel tubular stub columns under ...

    African Journals Online (AJOL)

    Instead, a simple summation of the strength of components forming the composite section is found to rationally predict the stub column strength. However, continued research is still required to accurately predict the effects of confinement, on the steel tube and on the fill material, hence expressions for the proportion of load ...

  12. REACTOR FILLED WITH CATALYST MATERIAL, AND CATALYST THEREFOR

    NARCIS (Netherlands)

    Sie, S.T.

    1995-01-01

    Abstract of WO 9521691 (A1) Described is a reactor (1) at least partially filled with catalyst granules (11), which is intended for catalytically reacting at least one gas and at least one liquid with each other. According to the invention the catalyst granules (11) are collected in agglomerates

  13. Evaluation of various filling techniques in distal canals of mandibular ...

    African Journals Online (AJOL)

    Background and Aims: The aim of this study was to evaluate the quality of various filling techniques in distal canals of mandibular molars instrumented with different single-file nickel-titanium (NiTi) systems. Materials and Methods: A total of 150 distal roots of mandibular molar teeth were randomly assigned into three main ...

  14. Form Filling with SCC in a Vertical Form

    DEFF Research Database (Denmark)

    Thrane, Lars Nyholm

    2004-01-01

    been produced. To improve identification of the flow (i.e. dead zones, plug flow, laminar flow, turbulent flow, blocking etc.) the form has one transparent acrylic plate and it has shown valuable to change between normal greyish concrete, and a pigmented (red) concrete during the filling process...

  15. Mean systemic filling pressure : from Guyton to the ICU

    NARCIS (Netherlands)

    Maas, Jacomina Johanna (Jacinta)

    2013-01-01

    Mean systemic filling pressure (Pmsf)is defined as the pressure in the blood vessels during cardiac arrest. Pmsf is an important determinant for venous return to the heart and thus for cardiac output. This thesis describes a method to measure Pmsf at the bedside in intensive care patients and

  16. Natural frequency of a circular cylindrical shell filled with fluid

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Kyeong Hoon; Kim, Tae Wan; Kim, Kang Soo; Park, Keun Bae [Korea Atomic Energy Research Institute, Taejon (Korea)

    1998-08-01

    This report presents an analytical method for evaluating the free vibration of a circular cylindrical shell filled with bounded compressible fluid. The analytical method was developed by means of the finite Fourier series expansion method. The compressible fluid motion was determined by means of the linear velocity potential theory. To clarify the validity of the analytical method, the natural frequencies of a circular cylindrical shell with the clamped-clamped boundary condition, and filled with water, were obtained by the analytical method and the finite element method using a commercial ANSYS 5.2 software. Excellent agreement on the natural frequencies of the fluid-filled shell structure was found. The compressibility and density of fluid effects the normalized coupled natural frequencies were investigated. The density of fluid affects on all coupled natural frequencies of the shell,, whereas the compressibility and bounding of fluid affects mainly on the natural frequencies of lower circumferential modes. The theory developed in this report will be applicable to the dynamic analysis of a core support barrel in SMART integral reactor filled with coolant. (author). 15 refs., 14 figs., 1 tab.

  17. Selection of direct restorative and rooting filling materials by Kenyan ...

    African Journals Online (AJOL)

    Objectives: To establish the categories of direct restorative and root filling materials used by dentists in Kenya as well as the factors considered in their selection. Design: A descriptive cross-sectional study. Setting: Public and private dental practices in major towns in Kenya. Participants: Registered, practicing dentists in ...

  18. 27 CFR 19.386 - Alcohol content and fill.

    Science.gov (United States)

    2010-04-01

    ... rebottle, recondition, or relabel spirits if the bottle contents do not agree with the respective data on... spirits and bottle sizes. For example, a product with a solids content of less than 600 mg per 100 ml... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Alcohol content and fill...

  19. Gap filling strategies for long term energy flux data sets

    NARCIS (Netherlands)

    Falge, E.; Baldocchi, D.; Olson, R.; Anthoni, P.; Aubinet, M.; Bernhofer, C.; Burba, G.; Ceulemans, R.; Clement, R.; Dolman, H.; Granier, A.; Gross, P.; Grünwald, T.; Hollinger, D.; Jensen, N.O.; Katul, G.; Keronen, P.; Kowalski, A.; Lai, C.T.; Law, B.E.; Meyers, T.; Moncrieff, J.; Moors, E.J.; Munger, J.W.; Pilegaard, K.; Rebmann, C.; Suyker, A.; Tenhunen, J.; Tu, K.

    2001-01-01

    At present a network of over 100 field sites are measuring carbon dioxide, water vapor and sensible heat fluxes between the biosphere and atmosphere, on a nearly continuous basis. Gaps in the long term measurements of evaporation and sensible heat flux must be filled before these data can be used

  20. Engineering study of tank fill options for landfill closure

    Energy Technology Data Exchange (ETDEWEB)

    Skelly, W.A.

    1996-09-27

    To prepare single-shell tanks for closure, it will be necessary to piece some type of load- bearing fill material inside the tanks to support the domes. Provision of internal support permits the simplifying assumption that the combined weight of the dome, the existing operational soil cover, and the surface barrier will eventually transfer to and be carried by the fill. This engineering study provides descriptions and evaluations of four alternative concepts for fitting and stabilizing nominally empty SSTs with fill materials. For this study it is assumed that 99 percent (or more) of tank wastes will be retrieved before closure is undertaken. The alternatives are: Gravel: tanks would be fitted with crushed aggregate using a rotating stinger apparatus installed in the central riser; Grout: tanks would be fitted with a pumpable, ex-situ mixed grout formulation; Hybrid: tanks would be fitted first with coarse aggregate, then with grout, producing a pre-placed aggregate concrete material; or Concrete: tank. would be filled with a highly-flowable, ex-situ mixed concrete formulation.

  1. Investigations of the properties of dredged limestone fill

    DEFF Research Database (Denmark)

    Foged, Niels; Gordon, Anne

    1999-01-01

    limestone fill that is pumped ito ponds of the reclamation site. The work utilised a number of geophysical and geotechnical investigation techniques in the field, supplemented with laboratory testing.The study of in-situ electrical resistivities revealed larger variations in the ground conditions than were...

  2. Assessment of periapical health, quality of root canal filling, and ...

    African Journals Online (AJOL)

    All data were entered on an MS Excel 2007 spreadsheet and SPSS software 15.0 which was used for statistical analysis. The Chi‑square test was used to determine if a patient's periapical status was associated with the technical quality of root filling, coronal status, and to evaluate differences between tooth subgroups.

  3. Assessment of periapical health, quality of root canal filling, and ...

    African Journals Online (AJOL)

    2015-12-03

    Dec 3, 2015 ... All data were entered on an MS Excel 2007 spreadsheet and SPSS software 15.0 which was used for statistical analysis. The Chi‑square test was used to determine if a patient's periapical status was associated with the technical quality of root filling, coronal status, and to evaluate differences between tooth ...

  4. Filling the Gap with Technology Innovations: Standards, Curriculum, Collaboration, Success!

    Science.gov (United States)

    Williams, Mia Kim; Foulger, Teresa S.

    2007-01-01

    Filling the Gap with Innovations is a study of a higher education professional development model used to infuse a teacher education program with technology innovations in order to address curriculum gaps. Professional educators at the university level are not traditionally collaborative. Yet, when an assessment of program alignment to state…

  5. Modelling the filling rate of pit latrines | Brouckaert | Water SA

    African Journals Online (AJOL)

    Excreta (faeces and urine) that are deposited into a pit latrine are subject to biodegradation, which substantially reduces the volume that remains. On the other hand, other matter that is not biodegradable usually finds itsway into pit latrines. The net filling rate is thus dependent on both the rate of addition of material and its ...

  6. FILLING RATE OF PIT LATRINES A CASE STUDY

    African Journals Online (AJOL)

    FILLING RATE OF PIT LATRINES. A CASE STUDY. Ginnay Kahssay. OXFAM Urban Project. Addis Ababa. As part of a comprehensive Urban Upgrading. Program, OXFAM (a U.K based charity organiz.ation) has been involved in the provision of basic sanitation facilities like improved pit latrines, domestic sewage disposal ...

  7. 27 CFR 24.260 - Serial numbers or filling date.

    Science.gov (United States)

    2010-04-01

    ... BUREAU, DEPARTMENT OF THE TREASURY LIQUORS WINE Storage, Treatment and Finishing of Wine Bottling, Packing, and Labeling of Wine § 24.260 Serial numbers or filling date. Each container larger than four liters or each case used for removing wine for consumption or sale will be marked with a serial number or...

  8. Urothelium update: how the bladder mucosa measures bladder filling

    NARCIS (Netherlands)

    Janssen, D.A.W.; Schalken, J.A.; Heesakkers, J.P.F.A.

    2017-01-01

    AIM: This review critically evaluates the evidence on mechanoreceptors and pathways in the bladder urothelium that are involved in normal bladder filling signalling. METHODS: Evidence from in vitro and in vivo studies on (i) signalling pathways like the adenosine triphosphate pathway, cholinergic

  9. Relationship between voice coil fill factor and loudspeaker efficiency

    DEFF Research Database (Denmark)

    Iversen, Niels Elkjær; Knott, Arnold; Andersen, Michael A. E.

    2016-01-01

    In modern audio systems, utilizing switch-mode amplifiers, the total efficiency is dominated by the rather poor efficiency of the loudspeaker. For decades voice coils have been designed so that nominal resistances of 3 to 8 Ω are obtained, despite modern audio amplifiers, using switch...... was measured to be 53 % which leaves plenty of room for future fill factor optimization....

  10. Fire Response of Concrete Filled Hollow Steel Sections

    DEFF Research Database (Denmark)

    Nyman, Simon; Virdi, Kuldeep

    2011-01-01

    Advanced and simplified methods of analysis and design for the fire resistance of structural elements and assemblages of structures have been developed in recent years. Some simplified methods for the fire design of concrete filled tubes have appeared in Eurocode 4 part 1.2. Experience to date in...

  11. Earthquake induced liquefaction analysis of Tendaho earth-fill dam ...

    African Journals Online (AJOL)

    fill dam, which is part of Tendaho Dam and Irrigation Project; the largest irrigation project in Ethiopia to date. The dam is located in the most seismic part of Ethiopia and was originally designed to be founded on potentially liquefiable alluvium ...

  12. Filling of recovered mining areas using solidifying backfill

    Directory of Open Access Journals (Sweden)

    Zeman Róbert

    2001-12-01

    Full Text Available The aim of this article is to explore the possibilities for filling recovered mining areas using solidifying backfill .The article describes the preparation of the backfill (backfill formulation with an eventual application using low quality sands, wastes from treatment plants and ash from power plants etc now to transport it as well as its application in practice. Advantageous and disadvantageous of this method are also mentioned.Several factors must be taken info consideration during the preparation process of the backfill mixture. Firstly, the quantities of each individual component must be constantly regulated. Secondly, the properties of each component must be respected. In addition, the needs of the pipeline transport system and the specific conditions of the recovered area to be filled must also be considered.Hydraulic transport and pneumo-hydraulic pipeline transport are used for handling the backfill. Pumps for transporting the solidifying backfill have to carry out demanding tasks.Due to the physical-mechanical properties of the backfill, only highly powerful pumps can be considered. Piston type pumps such as Abel Simplex and Duplex pumps with capacities of up to 100 m3.h-1 and operating pressures of up to 16 MPa would be suitable.This method has been applied abroad for different purposes. For example, solid backfill was used in the Hamr mine during exploitation of uranium using the room-and-pillar system mining method.In the Ostrava–Karvina Coal field, backfill was used in decontamination work, filling areas in a zone of dangerous deformations and for creating a dividing stratum during thick seam mining.Research info the use of solidifying backfill was also done in the Walsum mine in Germany. The aim of this research was:- to investigate the possibilities of filling a collapsing area in a working face using a solidifying mixture of power plant ash and water,- to verify whether towing pipelines proposed by the DMT corporation would be

  13. Worship space acoustics 3 decades of design

    CERN Document Server

    Ryherd, Erica; Ronsse, Lauren

    2016-01-01

    This book takes the reader on a wide-ranging tour through churches, synagogues, mosques, and other worship spaces designed during the past 30 years. The book begins with a series of essays on topics ranging from the soundscape of worship spaces to ecclesiastical design at the turn of the 21st Century. Perspective pieces from an architect, audio designer, music director, and worship space owner are also included. The core of the book presents the acoustical and architectural design of a wide variety of individual worship space venues. Acoustical consulting firms, architects, and worship space designers from across the world contributed their recent innovative works in the area of worship space acoustics. The contributions include detailed renderings and architectural drawings, as well as informative acoustic data graphs and evocative descriptions of the spaces. Filled with beautiful photography and fascinating modern design, this book is a must-read for anyone interested in religious architecture, acoustical d...

  14. Evaluation of Impact Force of Missile Filled with Fluid

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hyuk-Kee [Hyundai, Yongin (Korea, Republic of); Kim, Seung-Eock [Sejong University, Seoul (Korea, Republic of)

    2016-10-15

    In this paper, the effect of the fluid on the impact force was evaluated using the commercial software LS-DYNA. In order to verify the proposed finite element (FE) models, the impact force and impulse of the missiles filled with the fluid (wet missile) were investigated, and the analysis results were compared with the force plate tests conducted by VTT laboratory in Finland. A parametric study was performed to evaluate the impulse as per the position filled with the fluid and the impact velocity. The impulses of the wet missiles obtained from the parametric study were compared with those calculated by the modified Riera function. The effect of the fluid on the impact force was evaluated in this study. Based on this study, the following conclusions have been obtained: (1) The impulse/momentum ratios of the wet missiles filled with fluid in the front part were larger than those filled with fluid in the middle part. The difference was 5.5%, 5.3%, 6.2%, 3.8%, 2.9% and 1.0% for the impact velocities of 100 m/s, 110 m/s, 120 m/s, 130 m/s, 140 m/s, and 150 m/s, respectively. (2) The impulse/momentum ratios of the wet missiles by the FE analysis was larger than those by the modified Riera function up to 23.1% and 20.8%, respectively, when the fluid was filled in the front and middle parts. The modified Riera function underestimated the impulses of the wet missiles.

  15. Molecular pharmacognosy.

    Science.gov (United States)

    Huang, LuQi; Xiao, PeiGen; Guo, LanPing; Gao, WenYuan

    2010-06-01

    This article analyzes the background and significance of molecular pharmacognosy, including the molecular identification of medicinal raw materials, phylogenetic evolution of medicinal plants and animals, evaluation and preservation of germplasm resources for medicinal plants and animals, etiology of endangerment and protection of endangered medicinal plants and animals, biosynthesis and bioregulation of active components in medicinal plants, and characteristics and the molecular bases of top-geoherbs.

  16. Molecular Gastronomy

    OpenAIRE

    Burke, Roisin; This, Herve; Kelly, Alan

    2016-01-01

    Molecular gastronomy may be defined as the scientific discipline that explores the phenomena occurring during culinary transformations. In contrast with traditional approaches of food science and technology, which considered mostly the chemistry, physics, or biology of food ingredients and industrial transformations, the focus is on phenomena occurring during the preparation of dishes. Applications building on the principles of molecular gastronomy, such as ‘Molecular Cooking’ and ‘Note-by-No...

  17. The theory and application of space microbiology: China's experiences in space experiments and beyond.

    Science.gov (United States)

    Liu, Changting

    2017-02-01

    Microorganisms exhibit high adaptability to extreme environments of outer space via phenotypic and genetic changes. These changes may affect astronauts in the space environment as well as on Earth because mutant microbes will inevitably return with the spacecraft. However, the role and significance of these phenotypic changes and the underlying mechanisms are important unresolved questions in the field of space biology. By reviewing, especially the Chinese studies, we propose a space microbial molecular effect theory, that is, the space environment affects the nature of genes and the molecular structure of microorganisms to produce phenotypic changes. In this review, we discussed three basic theories for the research of space microbiology, including (1) space microbial pathogenicity and virulence mutations and the human mutualism theory; (2) space microbial drug-resistance mutations and metabolism associated with space pharmaceuticals theory; (3) space corrosion, microbial decontamination, and new materials technology theory. © 2016 Society for Applied Microbiology and John Wiley & Sons Ltd.

  18. Space suit

    Science.gov (United States)

    Shepard, L. F.; Durney, G. P.; Case, M. C.; Kenneway, A. J., III; Wise, R. C.; Rinehart, D.; Bessette, R. J.; Pulling, R. C. (Inventor)

    1973-01-01

    A pressure suit for high altitude flights, particularly space missions is reported. The suit is designed for astronauts in the Apollo space program and may be worn both inside and outside a space vehicle, as well as on the lunar surface. It comprises an integrated assembly of inner comfort liner, intermediate pressure garment, and outer thermal protective garment with removable helmet, and gloves. The pressure garment comprises an inner convoluted sealing bladder and outer fabric restraint to which are attached a plurality of cable restraint assemblies. It provides versitility in combination with improved sealing and increased mobility for internal pressures suitable for life support in the near vacuum of outer space.

  19. Morrey spaces

    CERN Document Server

    Adams, David R

    2015-01-01

    In this set of lecture notes, the author includes some of the latest research on the theory of Morrey Spaces associated with Harmonic Analysis. There are three main claims concerning these spaces that are covered: determining the integrability classes of the trace of Riesz potentials of an arbitrary Morrey function; determining the dimensions of singular sets of weak solutions of PDE (e.g. The Meyers-Elcart System); and determining whether there are any “full” interpolation results for linear operators between Morrey spaces. This book will serve as a useful reference to graduate students and researchers interested in Potential Theory, Harmonic Analysis, PDE, and/or Morrey Space Theory. .

  20. Space colonization

    National Research Council Canada - National Science Library

    Anita Gale; Narayanan Ramachandran

    2009-01-01

      Progress toward future space settlement is measured in small ways, mostly as incremental changes in perception and advances in targeted applied engineering that supports infrastructure development...

  1. Learning Spaces

    CERN Document Server

    Falmagne, Jean-Claude

    2011-01-01

    Learning spaces offer a rigorous mathematical foundation for practical systems of educational technology. Learning spaces generalize partially ordered sets and are special cases of knowledge spaces. The various structures are investigated from the standpoints of combinatorial properties and stochastic processes. Leaning spaces have become the essential structures to be used in assessing students' competence of various topics. A practical example is offered by ALEKS, a Web-based, artificially intelligent assessment and learning system in mathematics and other scholarly fields. At the heart of A

  2. The molecular universe

    Science.gov (United States)

    Tielens, A. G. G. M.

    2013-07-01

    Molecular absorption and emission bands dominate the visible, infrared, and submillimeter spectra of most objects with associated gas. These observations reveal a surprisingly rich array of molecular species and attest to a complex chemistry taking place in the harsh environment of the interstellar medium of galaxies. Molecules are truly everywhere and an important component of interstellar gas. This review surveys molecular observations in the various spectral windows and summarizes the chemical and physical processes involved in the formation and evolution of interstellar molecules. The rich organic inventory of space reflects the multitude of chemical processes involved that, on the one hand, build up molecules an atom at a time and, on the other hand, break down large molecules injected by stars to smaller fragments. Both this bottom-up and the trickle-down chemistry are reviewed. The emphasis is on understanding the characteristics of complex polycyclic aromatic hydrocarbon molecules and fullerenes and their role in chemistry as well as the intricate interaction of gas-phase ion-molecule and neutral-neutral reactions and the chemistry taking place on grain surfaces in dense clouds in setting the organic inventory of regions of star and planet formation and their implications for the chemical history of the Solar System. Many aspects of molecular astrophysics are illustrated with recent observations of the HIFI instrument on the Herschel Space Observatory.

  3. Sorption of phenanthrene and benzene on differently structural kerogen: important role of micropore-filling.

    Science.gov (United States)

    Zhang, Yulong; Ma, Xiaoxuan; Ran, Yong

    2014-02-01

    Shale was thermally treated to obtain a series of kerogen with varied maturation. Their chemical, structural and porous properties were related to the sorption and/or desorption behaviors of phenanthrene and benzene. As the treatment temperature increases, aliphatic and carbonyl carbon of the kerogen samples decrease, while their aromaticity and maturation increase. Meanwhile, the isothermal nonlinearity of phenanthrene and benzene increases whereas the sorption capacity and micropore adsorption volumes (Vo,d) initially increase and then decrease. The Vo,d of benzene is significantly correlated with, but higher than that of phenanthrene, suggesting similar micropore filling mechanism and molecular sieve effect. The benzene desorption exhibits hysteresis, which is related to the pore deformation of the kerogen and the entrapment of solute in the kerogen matrix. The Vo,d of phenanthrene and benzene on the kerogen samples accounts for 23-46% and 36-65% of the maximum sorption volumes, respectively, displaying the importance of the micropore filling. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. Measurements of density profile evolution during the stably-stratified filling of an open enclosure

    Energy Technology Data Exchange (ETDEWEB)

    Tarawneh, Constantine M. [Department of Mechanical Engineering, University of Texas-Pan American, Edinburg, TX 78539-2999 (United States); Homan, K.O. [Department of Mechanical and Aerospace Engineering, Missouri University of Science and Technology, formerly University of Missouri-Rolla, Rolla, MO 65409-0050 (United States)], E-mail: khoman@umr.edu

    2008-08-15

    The stably-stratified filling of an open enclosure produces an interfacial gradient layer which is transported through the enclosure with the bulk flow. The evolution of this interfacial layer is strongly time-dependent and is driven by the nature of the interaction between the internal gravity waves and the inlet-driven interfacial shear. Measurements of density profile evolution have been completed for a rectangular enclosure with a single corner inlet and density variation produced by saline concentration. This system serves as a mass transfer analog to large-scale, thermally-stratified energy storage devices, preserving dynamic similitude in a laboratory-scale system. The experiments covered jet Reynolds numbers of 200-2200 and Froude numbers of 0.06-0.6 in an enclosure with a width 23 times the jet inlet height. The density profiles are seen to be strongly asymmetric and exhibit growth rates significantly different than due to simple one-dimensional molecular diffusion. In addition, shadowgraph and hydrogen bubble visualizations of the density and velocity fields in the gradient layer show the persistence of complex multi-dimensional flow structure even at relatively late stages of the filling process when the gradient layer has been transported well away from the enclosure inlet. The evolution of the vertical density profile has been compared quantitatively to a quasi one-dimensional model based upon empirical diffusivity coefficients.

  5. GaAs quantum dot molecules filled into droplet etched nanoholes

    Science.gov (United States)

    Heyn, Ch.; Küster, A.; Gräfenstein, A.; Ungeheuer, A.; Graf, A.; Hansen, W.

    2017-11-01

    We fabricate self-aligned vertically stacked GaAs quantum dot molecules (QDMs) by filling of self-assembled nanoholes in AlGaAs. The tunable nanoholes are created using local droplet etching (LDE) combining conventional molecular beam epitaxy with self-assembled, lithography-free patterning. The optical emission from single, strain-free QDMs shows clear excitonic features with linewidths below 150 μeV after optimizations of the fabrication process. This allows investigations of the coupling among the individual dots forming a QDM. In electric fields oriented along the axis of the QDM, luminescence emission from direct and indirect transitions can be clearly distinguished. Furthermore, an anti-crossing behaviour demonstrates inter-dot coupling in the QDM.

  6. [Antibacterial effect of the materials for the root canal filling, bases and material for the cavity fillings].

    Science.gov (United States)

    Ferk, Suzana; Simeon, Paris; Mehicić, Goranka Prpić; Kalenić, Smilja; Anić, Ivica; Jukić, Silvana

    2011-02-01

    To assess antimicrobial effects of the materials used in the endodontic treatment of the teeth. The following root-canal fillings were examined: Ketac Endo, AH Plus, Diaket, and gutta-percha, by means of the agar diffusion test. As for the base materials, Zink Oxide/Eugenol cement, glass-ionomere cements Fuji II LC Improved, Ketac Cem, and phosphate cement and Harvard cement were investigated. Finally, of the materials for final cavity filling, amalgam, Ketac Molar and Fuji II LC Improved were tested. In the present research, the following bacteria were applied: Streptococcus mutans, Streptotoccus mitis, Lactobacillus species, Staphylococcus aureus, Enterococcusfaecalis, and polymicrobial suspention. For each individual bacterium tested, material samples were placed on the inoculated plates of blood-agar. Antibacterial effects were confirmed in the following materials: root-canal fillings--Diaket, AH Plus, Ketac Endo; bases--Zink Oxide/Eugenol cement, phosphat cement and Harvard cement. No antibacterial effect was established in: amalgam, gutta-percha, Fuji II LC Improved, Ketac Cem and Ketac Molar. Diaket showed a statistically more significant antibacterial effect in comparison with AH Plus, Ketac Endo, and gutta-percha (P(s.mitis) staphilococcus) < 0.05; p(polymicrobial) < 0.05); of the base materials, however, a somewhat stronger antimicrobial effect was found in phosphate cement, Harvard cement, and Zink Oxide/Eugenol (ZnOE) (p < 0.05) as compared with Fuji II LC Improved and Ketac Cem. According to the results of this study, and considering the fact that all cavity-filling materials failed to show any antimicrobial effect at all, when choosing the materials for root-canal fillings, and for bases, advantage should be given to those with the manifested strongest antibacterial effect, namely Diaket and phosphate cement.

  7. Beyond Space For Spatial Networks

    CERN Document Server

    Expert, Paul; Blondel, Vincent D; Lambiotte, Renaud

    2010-01-01

    Many complex systems are organized in the form of a network embedded in space. Important examples include the physical Internet infrastucture, road networks, flight connections, brain functional networks and social networks. The effect of space on network topology has recently come under the spotlight because of the emergence of pervasive technologies based on geo-localization, which constantly fill databases with people's movements and thus reveal their trajectories and spatial behaviour. Extracting patterns and regularities from the resulting massive amount of human mobility data requires the development of appropriate tools for uncovering information in spatially-embedded networks. In contrast with most works that tend to apply standard network metrics to any type of network, we argue in this paper for a careful treatment of the constraints imposed by space on network topology. In particular, we focus on the problem of community detection and propose a modularity function adapted to spatial networks. We sh...

  8. Molecular dynamics

    NARCIS (Netherlands)

    Bergstra, J.A.; Bethke, I.

    2002-01-01

    Molecular dynamics is a model for the structure and meaning of object based programming systems. In molecular dynamics the memory state of a system is modeled as a fluid consisting of a collection of molecules. Each molecule is a collection of atoms with bindings between them. A computation is

  9. Comparative properties of natural rubber vulcanisates filled with defatted rice bran, clay and calcium carbonate

    Directory of Open Access Journals (Sweden)

    Darinya Moonchai

    2012-07-01

    Full Text Available The effects of defatted rice bran (DRB as a filler for natural rubbervulcanisate on its cure characteristics, mechanical properties and morphology wereinvestigated. The properties of the DRB-filled vulcanisate were also compared with clayfilledand CaCO3-filled vulcanisates. At similar loading level (50 parts per hundred ofrubber, DRB-filled vulcanisate gave the shortest cure time. Clay-filled vulcanisateshowed highest tensile and tear strength followed by DRB-filled vulcanisate. However,CaCO3-filled vulcanisate gave highest rebound resilience while DRB-filled vulcanisateexhibited highest modulus, hardness and abrasion resistance. Scanning electronmicrographs revealed that the morphology of clay-filled vulcanisate was morehomogenous than that of DRB-filled and CaCO3-filled vulcanisates. According to theseobservations, DRB can potentially be used as a cheap and more environment-friendlynatural filler when an improvement in mechanical properties was not so critical.

  10. Molecular motors

    Science.gov (United States)

    Allemand, Jean François Desbiolles, Pierre

    2015-10-01

    How do we move? More precisely, what are the molecular mechanisms that can explain that our muscles, made of very small components can move at a osopic scale? To answer these questions we must introduce molecular motors. Those motors are proteins, or small protein assemblies that, in our cells, transform chemical energy into mechanical work. Then, like we could do for a oscopic motor, used in a car or in a fan, we are going to study the basic behavior of these molecular machines, present what are their energy sources, calculate their power, their yield. If molecular motors are crucial for our oscopic movements, we are going to see that they are also essential to cellular transport and that considering the activity of some enzymes as molecular motors bring some interesting new insights on their activity.

  11. Space psychology

    Science.gov (United States)

    Parin, V. V.; Gorbov, F. D.; Kosmolinskiy, F. P.

    1974-01-01

    Psychological selection of astronauts considers mental responses and adaptation to the following space flight stress factors: (1) confinement in a small space; (2) changes in three dimensional orientation; (3) effects of altered gravity and weightlessness; (4) decrease in afferent nerve pulses; (5) a sensation of novelty and danger; and (6) a sense of separation from earth.

  12. Borel Spaces

    CERN Document Server

    Berberian, S K

    2002-01-01

    A detailed exposition of G.W. Mackey's theory of Borel spaces (standard, substandard, analytic), based on results in Chapter 9 of Bourbaki's General Topology. Appended are five informal lectures on the subject (given at the CIMPA/ICPAM Summer School, Nice, 1986), sketching the connection between Borel spaces and representations of operator algebras.

  13. Space Telescope.

    Science.gov (United States)

    National Aeronautics and Space Administration, Huntsville, AL. George C. Marshall Space Flight Center.

    This pamphlet describes the Space Telescope, an unmanned multi-purpose telescope observatory planned for launch into orbit by the Space Shuttle in the 1980s. The unique capabilities of this telescope are detailed, the major elements of the telescope are described, and its proposed mission operations are outlined. (CS)

  14. Space microbiology.

    Science.gov (United States)

    Horneck, Gerda; Klaus, David M; Mancinelli, Rocco L

    2010-03-01

    The responses of microorganisms (viruses, bacterial cells, bacterial and fungal spores, and lichens) to selected factors of space (microgravity, galactic cosmic radiation, solar UV radiation, and space vacuum) were determined in space and laboratory simulation experiments. In general, microorganisms tend to thrive in the space flight environment in terms of enhanced growth parameters and a demonstrated ability to proliferate in the presence of normally inhibitory levels of antibiotics. The mechanisms responsible for the observed biological responses, however, are not yet fully understood. A hypothesized interaction of microgravity with radiation-induced DNA repair processes was experimentally refuted. The survival of microorganisms in outer space was investigated to tackle questions on the upper boundary of the biosphere and on the likelihood of interplanetary transport of microorganisms. It was found that extraterrestrial solar UV radiation was the most deleterious factor of space. Among all organisms tested, only lichens (Rhizocarpon geographicum and Xanthoria elegans) maintained full viability after 2 weeks in outer space, whereas all other test systems were inactivated by orders of magnitude. Using optical filters and spores of Bacillus subtilis as a biological UV dosimeter, it was found that the current ozone layer reduces the biological effectiveness of solar UV by 3 orders of magnitude. If shielded against solar UV, spores of B. subtilis were capable of surviving in space for up to 6 years, especially if embedded in clay or meteorite powder (artificial meteorites). The data support the likelihood of interplanetary transfer of microorganisms within meteorites, the so-called lithopanspermia hypothesis.

  15. Space Robotics

    Directory of Open Access Journals (Sweden)

    Alex Ellery

    2004-09-01

    Full Text Available In this second of three short papers, I introduce some of the basic concepts of space robotics with an emphasis on some specific challenging areas of research that are peculiar to the application of robotics to space infrastructure development. The style of these short papers is pedagogical and the concepts in this paper are developed from fundamental manipulator robotics. This second paper considers the application of space manipulators to on-orbit servicing (OOS, an application which has considerable commercial application. I provide some background to the notion of robotic on-orbit servicing and explore how manipulator control algorithms may be modified to accommodate space manipulators which operate in the micro-gravity of space.

  16. Interconnect patterns for printed organic thermoelectric devices with large fill factors

    Science.gov (United States)

    Gordiz, Kiarash; Menon, Akanksha K.; Yee, Shannon K.

    2017-09-01

    Organic materials can be printed into thermoelectric (TE) devices for low temperature energy harvesting applications. The output voltage of printed devices is often limited by (i) small temperature differences across the active materials attributed to small leg lengths and (ii) the lower Seebeck coefficient of organic materials compared to their inorganic counterparts. To increase the voltage, a large number of p- and n-type leg pairs is required for organic TEs; this, however, results in an increased interconnect resistance, which then limits the device output power. In this work, we discuss practical concepts to address this problem by positioning TE legs in a hexagonal closed-packed layout. This helps achieve higher fill factors (˜91%) than conventional inorganic devices (˜25%), which ultimately results in higher voltages and power densities due to lower interconnect resistances. In addition, wiring the legs following a Hilbert spacing-filling pattern allows for facile load matching to each application. This is made possible by leveraging the fractal nature of the Hilbert interconnect pattern, which results in identical sub-modules. Using the Hilbert design, sub-modules can better accommodate non-uniform temperature distributions because they naturally self-localize. These device design concepts open new avenues for roll-to-roll printing and custom TE module shapes, thereby enabling organic TE modules for self-powered sensors and wearable electronic applications.

  17. Filling constraints for spin-orbit coupled insulators in symmorphic and nonsymmorphic crystals.

    Science.gov (United States)

    Watanabe, Haruki; Po, Hoi Chun; Vishwanath, Ashvin; Zaletel, Michael

    2015-11-24

    We determine conditions on the filling of electrons in a crystalline lattice to obtain the equivalent of a band insulator--a gapped insulator with neither symmetry breaking nor fractionalized excitations. We allow for strong interactions, which precludes a free particle description. Previous approaches that extend the Lieb-Schultz-Mattis argument invoked spin conservation in an essential way and cannot be applied to the physically interesting case of spin-orbit coupled systems. Here we introduce two approaches: The first one is an entanglement-based scheme, and the second one studies the system on an appropriate flat "Bieberbach" manifold to obtain the filling conditions for all 230 space groups. These approaches assume only time reversal rather than spin rotation invariance. The results depend crucially on whether the crystal symmetry is symmorphic. Our results clarify when one may infer the existence of an exotic ground state based on the absence of order, and we point out applications to experimentally realized materials. Extensions to new situations involving purely spin models are also mentioned.

  18. Electromagnetic radiations from laser interaction with gas-filled Hohlraum

    Science.gov (United States)

    Yang, Ming; Yang, Yongmei; Li, Tingshuai; Yi, Tao; Wang, Chuanke; Liu, Shenye; Jiang, Shaoen; Ding, Yongkun

    2018-01-01

    The emission of intensive electromagnetic pulse (EMP) due to laser-target interactions at the ShenGuang-III laser facility has been evaluated by probes. EMP signals measured using the small discone antennas demonstrated two variation trends including a bilateral oscillation wave and a unilateral oscillation wave. The new trend of unilateral oscillation could be attributed to the hohlraum structure and low-Z gas in the hohlraum. The EMP waveform showed multiple peaks when the gas-filled hohlraum was shot by the high-power laser. Comparing the EMP signals with the verification of stimulated Raman scattering energy and hard x-ray energy spectrum, we found that the intensity of EMP signals decreased with the increase of the hohlraum size. The current results are expected to offer preliminary information to study physical processes on laser injecting gas-filled hohlraums in the National Ignition Facility implementation.

  19. Is a drill-less dental filling possible?

    Science.gov (United States)

    Quock, Ryan L; Patel, Shalizeh A; Falcao, Felipe A; Barros, Juliana A

    2011-09-01

    Dental caries, a bacterial process that results in the acidic destruction of tooth structure, has historically been managed by the mechanical excavation of diseased tooth structure and then restoration with a synthetic material. The mechanical excavation of the infected site is most commonly achieved by a dental handpiece, or "drill"; this handpiece may induce stress and anxiety in many patients. Alternatively, a drill-less filling will involve the utilization of silver diamine fluoride (38%) to arrest and prevent dental caries, followed by restoration with a bonded filling material to achieve adequate seal at the lesion margins. This is a minimally invasive procedure that addresses both microbial and mechanical issues posed by dental caries. Copyright © 2011 Elsevier Ltd. All rights reserved.

  20. Wear properties of nanosilica filled epoxy polymers and FRP composites

    Directory of Open Access Journals (Sweden)

    A. Jumahat

    2015-09-01

    Full Text Available This paper is aimed to determine the wear properties of nanosilica filled epoxy polymers and FRP composites. Woven fiberglass has been deployed as the reinforcement material. The fibers were mixed with three different percentages of nanosilica-modified epoxy resin, i.e: 5wt%; 13wt%; 25wt%, in order to fabricate the desired samples of FRP composites. The effect of nanosilica on wear properties was evaluated using dry sliding wear and slurry tests. The results show that increasing the amount of nanosilica content has reduced the amount of accumulated mass loss. It was found that the FRP laminates with 25wt% of nanosilica have the highest wear resistance. The nanosilica filled fiber reinforced polymer composites have a high potential in tribological application such as ball bearing housing and snow sleds.

  1. Flexural Behavior of GFRP Tubes Filled with Magnetically Driven Concrete.

    Science.gov (United States)

    Xie, Fang; Chen, Ju; Dong, Xinlong; Feng, Bing

    2018-01-08

    Experimental investigation of GFRP (glass fiber reinforced polymer) tubes that were filled with magnetically driven concrete was carried out to study the flexural behavior of specimens under bending. Specimens having different cross section and lengths were tested. The test specimens were fabricated by filling magnetically driven concrete into the GFRP tubes and the concrete was vibrated using magnetic force. Specimens vibrated using vibrating tube were also tested for comparison. In addition, specimens having steel reinforcing bars and GFRP bars were both tested to study the effect of reinforcing bars on the magnetically driven concrete. The load-displacement curves, load-strain curves, failure mode, and ultimate strengths of test specimens were obtained. Design methods for the flexural stiffness of test specimens were also discussed in this study.

  2. Flexural Behavior of GFRP Tubes Filled with Magnetically Driven Concrete

    Directory of Open Access Journals (Sweden)

    Fang Xie

    2018-01-01

    Full Text Available Experimental investigation of GFRP (glass fiber reinforced polymer tubes that were filled with magnetically driven concrete was carried out to study the flexural behavior of specimens under bending. Specimens having different cross section and lengths were tested. The test specimens were fabricated by filling magnetically driven concrete into the GFRP tubes and the concrete was vibrated using magnetic force. Specimens vibrated using vibrating tube were also tested for comparison. In addition, specimens having steel reinforcing bars and GFRP bars were both tested to study the effect of reinforcing bars on the magnetically driven concrete. The load-displacement curves, load-strain curves, failure mode, and ultimate strengths of test specimens were obtained. Design methods for the flexural stiffness of test specimens were also discussed in this study.

  3. Proust-Deleuze : les signes des jeunes filles

    Directory of Open Access Journals (Sweden)

    Olga López

    2015-12-01

    Full Text Available This article analyses the presence of jeunes filles in literature, in particular in the work of Marcel Proust. The signs through which jeune fille characters are constructed will be identified and collected, signs that, according to Deleuze, played a fundamental role in the constitution of the affects for the author of À la recherche du temps perdu. Through considering these signs a model will begin to be built of the “jeune fille”, not in order to uncover a final answer or provide a definition, but so as to conceptualize the existence of these elusive and mutable characters. This will include providing evidence of the repetition of difference inscribed in Proustian aesthetics.

  4. The dynamic response of carbon fiber-filled polymer composites

    Science.gov (United States)

    Dattelbaum, D. M.; Gustavsen, R. L.; Sheffield, S. A.; Stahl, D. B.; Scharff, R. J.; Rigg, P. A.; Furmanski, J.; Orler, E. B.; Patterson, B.; Coe, J. D.

    2012-08-01

    The dynamic (shock) responses of two carbon fiber-filled polymer composites have been quantified using gas gun-driven plate impact experimentation. The first composite is a filament-wound, highly unidirectional carbon fiber-filled epoxy with a high degree of porosity. The second composite is a chopped carbon fiber- and graphite-filled phenolic resin with little-to-no porosity. Hugoniot data are presented for the carbon fiber-epoxy (CE) composite to 18.6 GPa in the through-thickness direction, in which the shock propagates normal to the fibers. The data are best represented by a linear Rankine-Hugoniot fit: Us = 2.87 + 1.17 ×up(ρ0 = 1.536g/cm3). The shock wave structures were found to be highly heterogeneous, both due to the anisotropic nature of the fiber-epoxy microstructure, and the high degree of void volume. Plate impact experiments were also performed on a carbon fiber-filled phenolic (CP) composite to much higher shock input pressures, exceeding the reactants-to-products transition common to polymers. The CP was found to be stiffer than the filament-wound CE in the unreacted Hugoniot regime, and transformed to products near the shock-driven reaction threshold on the principal Hugoniot previously shown for the phenolic binder itself. [19] On-going research is focused on interrogating the direction-dependent dyanamic response and dynamic failure strength (spall) for the CE composite in the TT and 0∘ (fiber) directions.

  5. The dynamic response of carbon fiber-filled polymer composites

    Directory of Open Access Journals (Sweden)

    Patterson B.

    2012-08-01

    Full Text Available The dynamic (shock responses of two carbon fiber-filled polymer composites have been quantified using gas gun-driven plate impact experimentation. The first composite is a filament-wound, highly unidirectional carbon fiber-filled epoxy with a high degree of porosity. The second composite is a chopped carbon fiber- and graphite-filled phenolic resin with little-to-no porosity. Hugoniot data are presented for the carbon fiber-epoxy (CE composite to 18.6 GPa in the through-thickness direction, in which the shock propagates normal to the fibers. The data are best represented by a linear Rankine-Hugoniot fit: Us = 2.87 + 1.17 ×up(ρ0 = 1.536g/cm3. The shock wave structures were found to be highly heterogeneous, both due to the anisotropic nature of the fiber-epoxy microstructure, and the high degree of void volume. Plate impact experiments were also performed on a carbon fiber-filled phenolic (CP composite to much higher shock input pressures, exceeding the reactants-to-products transition common to polymers. The CP was found to be stiffer than the filament-wound CE in the unreacted Hugoniot regime, and transformed to products near the shock-driven reaction threshold on the principal Hugoniot previously shown for the phenolic binder itself. [19] On-going research is focused on interrogating the direction-dependent dyanamic response and dynamic failure strength (spall for the CE composite in the TT and 0∘ (fiber directions.

  6. Quantum Hall Mach-Zehnder interferometer at fractional filling factors

    OpenAIRE

    Deviatov, E. V.; Egorov, S. V.; Biasiol, G.; Sorba, L.

    2012-01-01

    We use a Mach-Zehnder quantum Hall interferometer of a novel design to investigate the interference effects at fractional filling factors. Our device brings together the advantages of usual Mach-Zehnder and Fabry-Perot quantum Hall interferometers. It realizes the simplest-for-analysis Mach-Zehnder interference scheme, free from Coulomb blockade effects. By contrast to the standard Mach-Zehnder realization, our device does not contain an etched region inside the interference loop. For the fir...

  7. Newtonian Atlas for Dust-Filled FRW Universe

    CERN Document Server

    Manton, Nicholas S

    2013-01-01

    The metric of an FRW universe filled with pressureless dust is shown to agree, close to any spacetime point, with a curved Newtonian-type metric where Einstein's equations simplify to those of Newtonian gravity. The agreement is shown to quadratic order in the local coordinates, so the curvatures agree. This result is established by expressing both metrics in Riemann normal form. This approach gives a local Newtonian understanding of cosmology that avoids the paradoxes of global Newtonian cosmology.

  8. Natural vibration frequencies of horizontal tubes partially filled with liquid

    Science.gov (United States)

    Santisteban Hidalgo, Juan Andrés; Gama, Antonio Lopes; Moreira, Roger Matsumoto

    2017-11-01

    This work presents an experimental and numerical study on the flexural vibration of horizontal circular tubes partially filled with liquid. The tube is configured as a free-free beam with attention being directed to the case of small amplitudes of transverse oscillation whereas the axial movements of the tube and liquid are disregarded. At first vertical and horizontal polarizations of the flexural tube are investigated experimentally for different amounts of filling liquid. In contrast with the empty and fully-filled tubes, it is observed that natural frequencies of the vertical and horizontal polarizations are different due to asymmetry induced by the liquid layer, which acts like an added mass. Less mass of liquid is added to the tube when oscillating horizontally; as a consequence, eigenfrequencies for the horizontal polarization are found to be greater than the case of the vertically polarized tube. A simple method to calculate the natural vibration frequencies using coefficients of added mass of liquid is proposed. It is shown that the added mass coefficient increases with the liquid's level and viscosity. At last a numerical investigation of the interaction between the liquid and the tube is carried out by solving in two-dimensions the full Navier-Stokes equations via a finite volume method, with the free-surface flow being modeled with a homogeneous multiphase Eulerian-Eulerian fluid approach. Vertical and horizontal polarizations are imposed to the tube with pressure and shear stresses being determined numerically to assess the liquid's forcing onto the tube's wall. The coefficient of added mass of liquid is then estimated by the ratio between the resulting force and the acceleration imposed to the wall. A good agreement is found between experimental and numerical results, especially for the horizontally oscillating tube. It is also shown that viscosity can noticeably affect the added mass coefficients, particularly at low filling levels.

  9. Continuous microbiological air monitoring for aseptic filling lines.

    Science.gov (United States)

    Scherwing, Claudia; Golin, Franco; Guenec, Olivier; Pflanz, Karl; Dalmaso, Gilberto; Bini, Manuela; Andone, Francesca

    2007-01-01

    Pharmaceutical aseptic filling lines are used to fill sterile biotechnology products without affecting their quality by a terminal sterilization step. Standard grade A filling environments are required to have meter (m3) of air. Aseptic filling is the production cycle with one of the highest contamination risks. A typical method of contamination monitoring is to actively draw air and filter it through special gelatin filters. The study aims to establish whether continuous sampling provides effective monitoring for the entire production process by determining whether trapped organisms can withstand long-term drying stress with unaltered recovery. In two experimental phases, the study examined microbial recovery in long-term air-stressed membranes as well as the viability of microorganisms on gelatin filters during 8-hour runs of filtration with high-efficiency particulate air-filtered air from a laminar flow hood using the MD 8 Airscan system. Stressed and unstressed filters were compared with parallel-run reference filters as controls. The CFUs were counted and the genus of the identified microorganism populations determined to examine any changes in microbiological flora occurring during continuous long-term sampling. Compared to the unstressed reference filters, neither total recovery nor recovered bacterial diversity changed. No statistically significant differences in CFUs were found between test filters and reference filters, nor were any statistically significant differences found in the microbiological flora between test filters and reference filters. CFU populations were comparable in both experiments. Eight hours of continuous air sampling on gelatin filters with the MD 8 Airscan system did not affect total recovery or change the diversity of recovered microorganisms compared to the controls.

  10. Symbolism of Street Art. Interview to La Fille Bertha

    Directory of Open Access Journals (Sweden)

    Melania Garau

    2016-07-01

    Full Text Available Interview to the illustrator La Fille Bertha. She started her artistic career in her childhood, when she first used sketchbooks and pencils. Through her magical symbolism she has now reached European Street Art, and also in the world of Fashion and Design. Her creatures come from a dreamlike-magical dimension, producing a colourful oasis in the noisy urban greyness. She also took part in the XXI Triennale di Milano.

  11. A Study of Filled and Sparse Line Array Beamformers.

    Science.gov (United States)

    1980-09-01

    RESOLUTION TESI CHART NAIII NAt RItRI Al SI 1TANT ART 1161 A - LEVEL($ 0met 0o 1 A STUDY OF FILLED AND SPARSE LINE ARRAY BEAMFORMERS y! C- I L1 0___...seau plecm) et le re’seau dans lequel un certain nombre de capteurs sont 6limin6s (re~seau 6pars). Les m6thodes examnees comprennent le forma- teur

  12. Thermal properties of epoxy composites filled with boric acid

    Science.gov (United States)

    Visakh, P. M.; Nazarenko, O. B.; Amelkovich, Yu A.; Melnikova, T. V.

    2015-04-01

    The thermal properties of epoxy composites filled with boric acid fine powder at different percentage were studied. Epoxy composites were prepared using epoxy resin ED-20, boric acid as flame-retardant filler, hexamethylenediamine as a curing agent. The prepared samples and starting materials were examined using methods of thermal analysis, scanning electron microscopy and infrared spectroscopy. It was found that the incorporation of boric acid fine powder enhances the thermal stability of epoxy composites.

  13. The association between root canal filling and treatment outcome.

    Science.gov (United States)

    Almohareb, Rahaf; Ahlquist, Michael; Englund, Gunilla Sandborgh

    2016-01-01

    The aim of the study was to evaluate the technical quality of endodontic treatment per- formed by postgraduate students in Karolinska Institutet, Stockholm, Sweden during the years (2008-2011) and to evaluate the treatment outcome. In addition, possible influencing factors to treatment outcome were analyzed. All maxillary first molars that received endo- dontic treatment between 2008 and 2011 were included in the study. Pre, post and follow up radiographs were collected.The apical status (PAI-score),the quality of the root canal treat- ment (RCT) and the treatment outcome were assessed. Analysis of the treatment outcome in relation to the quality of root canal treatment and other possible influencing variables was performed by Chi2 or Fisher's Exact test, and the statistical significance was set at Plength. In total, the treatment outcome was successful in 59 (81 %) of the cases. The success rate was 88% in cases with high quality root fillings, compared to 71% in cases with less good quality.There was a non- significant trend (P =0.066) of an association between RCT quality and treatment outcome. In conclusion the association between the quality of the root filling and the treatment outcome was not verified with statistical significance, but the results indicate a trend that satisfactory root fillings are associated with a favorable outcome.This study was limited by its retrospective nature and a relatively small sample size.

  14. On the inertial motions of liquid-filled rigid bodies

    Science.gov (United States)

    Mazzone, Giusy; Galdi, Giovanni; Zunino, Paolo

    2013-11-01

    We consider a rigid body with a cavity completely filled by a viscous liquid and study the inertial motions of the system liquid-filled rigid body S . The equations governing the motion of this coupled system are given by the Navier-Stokes equations and the equations of the balance of the total angular momentum of S in absence of external forces and torques. Given any initial motion to the coupled system, characterized by an initial relative velocity of the fluid and an initial total angular momentum, we give a complete description of the behavior that the system liquid-filled rigid body will show at large times. From both analytical and numerical viewpoints, we are able to prove a longstanding conjecture stated by Zhukovskii, namely that S will eventually reach a steady state which is a rigid body permanent rotation. In other words, the liquid goes to rest with respect to the rigid body and the coupled system will rotate as a whole rigid body, with a constant angular velocity that is directed along one of the principal axes of inertia of the system.

  15. Paired states in half-filled Landau levels

    Science.gov (United States)

    Milovanović, M. V.

    2017-06-01

    We discuss monolayer and bilayer quantum Hall systems in which each layer is a half-filled Landau level (LL) system. In the mean field approximation of the Son's formalism, there is a common pairing structure that underlines the possibilities for paired ground states in both systems. We argue that the particle-hole (PH) Pfaffian state in the (particle-hole symmetric) half-filled LL of a monolayer, and analogous state in the PH symmetric bilayer (in which each layer is half-filled LL) can be considered as critical states, i.e., states that cannot describe a phase under PH symmetry. We point out that the inclusion of a PH symmetry breaking (like LL mixing) may stabilize the PH Pfaffian in a monolayer. In the bilayer case, in numerical experiments on a sphere, by choosing the PH symmetric shift, we can stabilize the interlayer correlated (111) excitonic state or critical state, for any distance between the layers, but in general, with no bias, the evolution of the bilayer includes other phases.

  16. Hydraulic forces contribute to left ventricular diastolic filling

    Science.gov (United States)

    Maksuti, Elira; Carlsson, Marcus; Arheden, Håkan; Kovács, Sándor J.; Broomé, Michael; Ugander, Martin

    2017-01-01

    Myocardial active relaxation and restoring forces are known determinants of left ventricular (LV) diastolic function. We hypothesize the existence of an additional mechanism involved in LV filling, namely, a hydraulic force contributing to the longitudinal motion of the atrioventricular (AV) plane. A prerequisite for the presence of a net hydraulic force during diastole is that the atrial short-axis area (ASA) is smaller than the ventricular short-axis area (VSA). We aimed (a) to illustrate this mechanism in an analogous physical model, (b) to measure the ASA and VSA throughout the cardiac cycle in healthy volunteers using cardiovascular magnetic resonance imaging, and (c) to calculate the magnitude of the hydraulic force. The physical model illustrated that the anatomical difference between ASA and VSA provides the basis for generating a hydraulic force during diastole. In volunteers, VSA was greater than ASA during 75–100% of diastole. The hydraulic force was estimated to be 10–60% of the peak driving force of LV filling (1–3 N vs 5–10 N). Hydraulic forces are a consequence of left heart anatomy and aid LV diastolic filling. These findings suggest that the relationship between ASA and VSA, and the associated hydraulic force, should be considered when characterizing diastolic function and dysfunction. PMID:28256604

  17. Hydraulic forces contribute to left ventricular diastolic filling

    Science.gov (United States)

    Maksuti, Elira; Carlsson, Marcus; Arheden, Håkan; Kovács, Sándor J.; Broomé, Michael; Ugander, Martin

    2017-03-01

    Myocardial active relaxation and restoring forces are known determinants of left ventricular (LV) diastolic function. We hypothesize the existence of an additional mechanism involved in LV filling, namely, a hydraulic force contributing to the longitudinal motion of the atrioventricular (AV) plane. A prerequisite for the presence of a net hydraulic force during diastole is that the atrial short-axis area (ASA) is smaller than the ventricular short-axis area (VSA). We aimed (a) to illustrate this mechanism in an analogous physical model, (b) to measure the ASA and VSA throughout the cardiac cycle in healthy volunteers using cardiovascular magnetic resonance imaging, and (c) to calculate the magnitude of the hydraulic force. The physical model illustrated that the anatomical difference between ASA and VSA provides the basis for generating a hydraulic force during diastole. In volunteers, VSA was greater than ASA during 75-100% of diastole. The hydraulic force was estimated to be 10-60% of the peak driving force of LV filling (1-3 N vs 5-10 N). Hydraulic forces are a consequence of left heart anatomy and aid LV diastolic filling. These findings suggest that the relationship between ASA and VSA, and the associated hydraulic force, should be considered when characterizing diastolic function and dysfunction.

  18. Integration of different data gap filling techniques to facilitate ...

    Science.gov (United States)

    Data gap filling techniques are commonly used to predict hazard in the absence of empirical data. The most established techniques are read-across, trend analysis and quantitative structure-activity relationships (QSARs). Toxic equivalency factors (TEFs) are less frequently used data gap filling techniques which are applied to estimate relative potencies for mixtures of chemicals that contribute to an adverse outcome through a common biological target. For example, The TEF approach has been used for dioxin-like effects comparing individual chemical activity to that of the most toxic dioxin: 2,3,7,8-tetrachlorodibenzo-p-dioxin. The aim of this case study was to determine whether integration of two data gap filling techniques: QSARs and TEFs improved the predictive outcome for the assessment of a set of polychlorinated biphenyl (PCB) congeners and their mixtures. PCBs are associated with many different adverse effects, including their potential for neurotoxicity, which is the endpoint of interest in this study. The dataset comprised 209 PCB congeners, out of which 87 altered in vitro Ca(2+) homeostasis from which neurotoxic equivalency values (NEQs) were derived. The preliminary objective of this case study was to develop a QSAR model to predict NEQ values for the 122 untested PCB congeners. A decision tree model was developed using the number of position specific chlorine substitutions on the biphenyl scaffold as a fingerprint descriptor. Three different positiona

  19. Thermal Performance Evaluation of Walls with Gas Filled Panel Insulation

    Energy Technology Data Exchange (ETDEWEB)

    Shrestha, Som S. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Desjarlais, Andre Omer [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Atchley, Jerald Allen [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2014-11-01

    Gas filled insulation panels (GFP) are very light weight and compact (when uninflated) advanced insulation products. GFPs consist of multiple layers of thin, low emittance (low-e) metalized aluminum. When expanded, the internal, low-e aluminum layers form a honeycomb structure. These baffled polymer chambers are enveloped by a sealed barrier and filled with either air or a low-conductivity gas. The sealed exterior aluminum foil barrier films provide thermal resistance, flammability protection, and properties to contain air or a low conductivity inert gas. This product was initially developed with a grant from the U.S. Department of Energy. The unexpanded product is nearly flat for easy storage and transport. Therefore, transportation volume and weight of the GFP to fill unit volume of wall cavity is much smaller compared to that of other conventional insulation products. This feature makes this product appealing to use at Army Contingency Basing, when transportation cost is significant compared to the cost of materials. The objective of this study is to evaluate thermal performance of walls, similar to those used at typical Barracks Hut (B-Hut) hard shelters, when GFPs are used in the wall cavities. Oak Ridge National Laboratory (ORNL) tested performance of the wall in the rotatable guarded hotbox (RGHB) according to the ASTM C 1363 standard test method.

  20. Interaction between Total Cost and Fill Rate: A Case Study

    Directory of Open Access Journals (Sweden)

    Liljana Ferbar Tratar

    2016-09-01

    Full Text Available Forecasting plays a central role in the efficient operation of a supply chain – i.e., the total costs and fill rate. As forecasts of demand are required on a regular basis for a very large number of products, the methods developed should be fast, flexible, user-friendly, and able to produce results that are reliable and easy to interpret by a manager. In this paper we show that the supply chain costs cannot be optimal if the forecasting method is treated separately from the inventory model. We analyse the performance of the joint optimization of the modified Holt-Winters forecasting method and a stock control policy and investigate the effect of different penalties for unsatisfied demand on the total cost and fill rate of the supply chain. From the results obtained with 1,428 real time series from M3-Competition we show that an essential reduction of supply chain costs and an increase of fill rate can be achieved if we use the joint model with the modified Holt-Winters method.

  1. Effect of Filler Loading on the Molecular Movement of Benzene and ...

    African Journals Online (AJOL)

    The sorption behaviour of the solvents – benzene and toluene in calcite-filled low density polyethylene composite samples at 40oC and 65oC were investigated using gravimetric sorption method. The effect of calcite loading on the molecular movement of benzene and toluene through the calcite-filled LDPE composites ...

  2. Raman-induced temporal condensed matter physics in gas-filled photonic crystal fibers.

    Science.gov (United States)

    Saleh, Mohammed F; Armaroli, Andrea; Tran, Truong X; Marini, Andrea; Belli, Federico; Abdolvand, Amir; Biancalana, Fabio

    2015-05-04

    Raman effect in gases can generate an extremely long-living wave of coherence that can lead to the establishment of an almost perfect temporal periodic variation of the medium refractive index. We show theoretically and numerically that the equations, regulate the pulse propagation in hollow-core photonic crystal fibers filled by Raman-active gas, are exactly identical to a classical problem in quantum condensed matter physics - but with the role of space and time reversed - namely an electron in a periodic potential subject to a constant electric field. We are therefore able to infer the existence of Wannier-Stark ladders, Bloch oscillations, and Zener tunneling, phenomena that are normally associated with condensed matter physics, using purely optical means.

  3. Effect of Operating Frequency and Fill Time on PDE-Ejector Thrust Performance

    Science.gov (United States)

    Landry, K.; Santoro, Robert J.; Pal, Sibtosh; Shehadeh, R.; Bouvet, N.; Lee, S.-Y.

    2005-01-01

    Thrust measurements for a pulse detonation engine (PDE)-ejector system were determined for a range of operating frequencies. Various length tubular ejectors were utilized. The results were compared to the measurements of the thrust output of the PDE alone to determine the enhancement provided by each ejector configuration at the specified frequencies. Ethylene was chosen as the fuel, with an equi-molar mixture of nitrogen and oxygen acting as the oxidizer. The propellant was kept at an equivalence ratio of one during all the experiments. The system was operated for frequencies between 20 and 50 Hz. The parameter space of the study included PDE operation frequency, ejector length, overlap percentage, the radius of curvature for the ejector inlets, and duration of the time allowed between cycles. The results of the experiments showed a maximum thrust augmentation of 120% for a PDE-ejector configuration at a frequency of 40Hz with a fill time of 10 ms.

  4. Mode-based microparticle conveyor belt in air-filled hollow-core photonic crystal fiber.

    Science.gov (United States)

    Schmidt, Oliver A; Euser, Tijmen G; Russell, Philip St J

    2013-12-02

    We show how microparticles can be moved over long distances and precisely positioned in a low-loss air-filled hollow-core photonic crystal fiber using a coherent superposition of two co-propagating spatial modes, balanced by a backward-propagating fundamental mode. This creates a series of trapping positions spaced by half the beat-length between the forward-propagating modes (typically a fraction of a millimeter). The system allows a trapped microparticle to be moved along the fiber by continuously tuning the relative phase between the two forward-propagating modes. This mode-based optical conveyor belt combines long-range transport of microparticles with a positional accuracy of 1 µm. The technique also has potential uses in waveguide-based optofluidic systems.

  5. Molecular geometry

    CERN Document Server

    Rodger, Alison

    1995-01-01

    Molecular Geometry discusses topics relevant to the arrangement of atoms. The book is comprised of seven chapters that tackle several areas of molecular geometry. Chapter 1 reviews the definition and determination of molecular geometry, while Chapter 2 discusses the unified view of stereochemistry and stereochemical changes. Chapter 3 covers the geometry of molecules of second row atoms, and Chapter 4 deals with the main group elements beyond the second row. The book also talks about the complexes of transition metals and f-block elements, and then covers the organometallic compounds and trans

  6. Molecular Haeckel.

    Science.gov (United States)

    Elinson, Richard P; Kezmoh, Lorren

    2010-07-01

    More than a century ago, Ernst Haeckel created embryo drawings to illustrate the morphological similarity of vertebrate early embryos. These drawings have been both widely presented and frequently criticized. At the same time that the idea of morphological similarity was recently attacked, there has been a growing realization of molecular similarities in the development of tissues and organs. We have surveyed genes expressed in vertebrate embryos, and we have used them to construct drawings that we call Molecular Haeckels. The Molecular Haeckels emphasize that, based on gene expression, there is a greater similarity among vertebrate embryos than even Haeckel might have imagined. (c) 2010 Wiley-Liss, Inc.

  7. Stability analysis of liquid filled spacecraft system with flexible attachment by using the energy–Casimir method

    Directory of Open Access Journals (Sweden)

    Yulong Yan

    2016-03-01

    Full Text Available The stability of partly liquid filled spacecraft with flexible attachment was investigated in this paper. Liquid sloshing dynamics was simplified as the spring–mass model, and flexible attachment was modeled as the linear shearing beam. The dynamic equations and Hamiltonian of the coupled spacecraft system were given by analyzing the rigid body, liquid fuel, and flexible appendage. Nonlinear stability conditions of the coupled spacecraft system were derived by computing the variation of Casimir function which was added to the Hamiltonian. The stable region of the parameter space was given and validated by numerical computation. Related results suggest that the change of inertia matrix, the length of flexible attachment, spacecraft spinning rate, and filled ratio of liquid fuel tank have strong influence on the stability of the spacecraft system.

  8. Transient Response of a Fluid-Filled, Thick-Walled Spherical Shell Embedded in an Elastic Medium

    Directory of Open Access Journals (Sweden)

    Bahari Ako

    2016-01-01

    Full Text Available The paper addresses the problem of transient elastodynamics analysis of a thick-walled, fluid-filled spherical shell embedded in an elastic medium with an analytical approach. This configuration is investigated at first step for a full-space case. Different constitutive relations for the elastic medium, shell material and filling fluid can be considered, as well as different excitation sources (including S/P wave or plane/spherical incident wave at different locations. With mapmaking visualisation, the wave propagation phenomena can be described and better understood. The methodology is going to be applied to analysis of the tunnels or other shell like structures under the effect of nearby underground explosion.

  9. Knowledge spaces

    CERN Document Server

    Doignon, Jean-Paul

    1999-01-01

    Knowledge spaces offer a rigorous mathematical foundation for various practical systems of knowledge assessment. An example is offered by the ALEKS system (Assessment and LEarning in Knowledge Spaces), a software for the assessment of mathematical knowledge. From a mathematical standpoint, knowledge spaces generalize partially ordered sets. They are investigated both from a combinatorial and a stochastic viewpoint. The results are applied to real and simulated data. The book gives a systematic presentation of research and extends the results to new situations. It is of interest to mathematically oriented readers in education, computer science and combinatorics at research and graduate levels. The text contains numerous examples and exercises and an extensive bibliography.

  10. Space Bugz!

    DEFF Research Database (Denmark)

    Birke, Alexander; Schoenau-Fog, Henrik; Reng, Lars

    2012-01-01

    This paper presents Space Bugz! - a novel crowd game for large venues or cinemas that utilises the audience's smartphones as controllers for the game. This paper explains what crowd gaming is and describes how the approach used in Space Bugz! enables more advanced gameplay concepts and individual...... player control than current technologies allow. The gameplay of Space Bugz! is then explained along with the technical architecture of the game. After this, the iterative design process used to create the game is described together with future perspectives. The article concludes with links to a video...

  11. Highly Scalable and Memory Efficient Ultra-Coarse-Grained Molecular Dynamics Simulations.

    Science.gov (United States)

    Grime, John M A; Voth, Gregory A

    2014-01-14

    The use of coarse-grained (CG) models can significantly increase the time and length scales accessible to computational molecular dynamics (MD) simulations. To address very large-scale phenomena, however, requires a careful consideration of memory requirements and parallel MD load balancing in order to make efficient use of current supercomputers. In this work, a CG-MD code is introduced which is specifically designed for very large, highly parallel simulations of systems with markedly non-uniform particle distributions, such as those found in highly CG models having an implicit solvent. The CG-MD code uses an unorthodox combination of sparse data representations with a Hilbert space-filling curve (SFC) to provide dynamic topological descriptions, reduced memory overhead, and advanced load-balancing characteristics. The results of representative large-scale simulations indicate that our approach can offer significant advantages over conventional MD techniques, and should enable new classes of CG-MD systems to be investigated.

  12. CFD Modeling of Chamber Filling in a Micro-Biosensor for Protein Detection.

    Science.gov (United States)

    Islamov, Meiirbek; Sypabekova, Marzhan; Kanayeva, Damira; Rojas-Solórzano, Luis

    2017-10-03

    Tuberculosis (TB) remains one of the main causes of human death around the globe. The mortality rate for patients infected with active TB goes beyond 50% when not diagnosed. Rapid and accurate diagnostics coupled with further prompt treatment of the disease is the cornerstone for controlling TB outbreaks. To reduce this burden, the existing gap between detection and treatment must be addressed, and dedicated diagnostic tools such as biosensors should be developed. A biosensor is a sensing micro-device that consists of a biological sensing element and a transducer part to produce signals in proportion to quantitative information about the binding event. The micro-biosensor cell considered in this investigation is designed to operate based on aptamers as recognition elements against Mycobacterium tuberculosis secreted protein MPT64, combined in a microfluidic-chamber with inlet and outlet connections. The microfluidic cell is a miniaturized platform with valuable advantages such as low cost of analysis with low reagent consumption, reduced sample volume, and shortened processing time with enhanced analytical capability. The main purpose of this study is to assess the flooding characteristics of the encapsulated microfluidic cell of an existing micro-biosensor using Computational Fluid Dynamics (CFD) techniques. The main challenge in the design of the microfluidic cell lies in the extraction of entrained air bubbles, which may remain after the filling process is completed, dramatically affecting the performance of the sensing element. In this work, a CFD model was developed on the platform ANSYS-CFX using the finite volume method to discretize the domain and solving the Navier-Stokes equations for both air and water in a Eulerian framework. Second-order space discretization scheme and second-order Euler Backward time discretization were used in the numerical treatment of the equations. For a given inlet-outlet diameter and dimensions of an in-house built cell chamber

  13. The Application of Noninvasive Headspace Analysis to Media Fill Inspection.

    Science.gov (United States)

    Duncan, Derek; Cundell, Tony; Levac, Lauren; Veale, James; Kuiper, Suzanne; Rao, Ravi

    2016-01-01

    The results of a proof-of-principle study demonstrating a new analytical technique for detecting microbial growth directly in pharmaceutical containers are described. This analytical technique, laser-based headspace analysis, uses tunable diode laser absorption spectroscopy to nondestructively determine gas concentrations in the headspace of a media-filled pharmaceutical container. For detecting microbial growth, the levels of headspace oxygen and carbon dioxide are measured. Once aerobic microorganisms begin to divide after the lag phase and enter the exponential growth phase, there will be significant consumption of oxygen and concomitant production of carbon dioxide in the sealed container. Laser-based headspace analysis can accurately measure these changes in the headspace gas composition. The carbon dioxide and oxygen measurement data for the representative microorganisms Staphylococcus aureus, Bacillus subtilis, Candida albicans, and Aspergillus brasiliensis were modeled using the Baranyi-Roberts equation. The mathematical modeling allowed quantitative comparisons to be made between the data from the different microorganisms as well as to the known growth curves based on microbial count. Because laser-based headspace analysis is noninvasive and can be automated to analyze the headspace of pharmaceutical containers at inspection speeds of several hundred containers per minute on-line, some potential new applications are enabled. These include replacing the current manual human visual inspection with an automated analytical inspection machine to determine microbial contamination of media fill and pharmaceutical drug product vials. A novel analytical technique has been demonstrated for detecting microbial growth in media-filled pharmaceutical containers. This analytical technique, laser-based headspace analysis, uses tunable diode laser absorption spectroscopy to determine gas concentrations in the headspace of a pharmaceutical container. For detecting microbial

  14. Evaluating the robustness of the enantioselective stationary phases on the Rosetta mission against space vacuum vaporization

    Science.gov (United States)

    Meierhenrich, Uwe J.; Cason, Julie R. L.; Szopa, Cyril; Sternberg, Robert; Raulin, François; Thiemann, Wolfram H.-P.; Goesmann, Fred

    2013-12-01

    The European Space Agency's Rosetta mission was launched in March 2004 in order to reach comet 67P/Churyumov-Gerasimenko by August 2014. The Cometary Sampling and Composition experiment (COSAC) onboard the Rosetta mission's lander "Philae" has been designed for the cometary in situ detection and quantification of organic molecules using gas chromatography coupled to mass spectrometry (GC-MS). The GC unit of COSAC is equipped with eight capillary columns that will each provide a specific stationary phase for molecular separation. Three of these stationary phases will be used to chromatographically resolve enantiomers, as they are composed of liquid polymers of polydimethylsiloxane (PDMS) to which chiral valine or cyclodextrin units are attached. Throughout the ten years of Rosetta's journey through space to reach comet 67P, these liquid stationary phases have been exposed to space vacuum, as the capillary columns within the COSAC unit were not sealed or filled with carrier gas. Long term exposures to space vacuum can cause damage to such liquid stationary phases as key monomers, volatiles, and chiral selectors can be vaporized and lost in transit. We have therefore exposed identical spare units of COSAC's chiral stationary phases over eight years to vacuum conditions mimicking those experienced in space and we have now investigated their resolution capabilities towards different enantiomers both before and after exposure to space vacuum environments. We have observed that enantiomeric resolution capabilities of these chiral liquid enantioselective stationary phases has not been affected by exposure to space vacuum conditions. Thus we conclude that the three chiral stationary phases of the COSAC experiment onboard the Rosetta mission lander "Philae" can be considered to have maintained their resolution capacities throughout their journey prior to cometary landing in November 2014.

  15. Molecular Origami

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 5; Issue 9. Molecular Origami - Modular Construction of Platonic Solids as Models for Reversible Assemblies. Subramania Ranganathan. General Article Volume 5 Issue 9 September 2000 pp 82-91 ...

  16. Space colonization

    National Research Council Canada - National Science Library

    Ram Ramachandran; Anita Gale

    2010-01-01

    .... government trying to reinvent the human space program priorities and approaches. Russia, ESA, Japan, China, and India all have proposed ambitious missions, including manned missions, to the Moon and planets...

  17. Space exploration

    National Research Council Canada - National Science Library

    Chris Moore

    2012-01-01

      Here, Moore presents a year in review on space exploration programs. This 2012 NASA's strategy of stimulating the development of commercial capabilities to launch crew and cargo to the ISS began to pay off...

  18. SHIMMERING SPACE

    Directory of Open Access Journals (Sweden)

    Grazielle Katyane dos Santos Silva

    2009-04-01

    Full Text Available This article presents an analysis of spatiality in the book Os guarda-chuvas cintilantes (Shimmering Umbrellas, 1984, written by the Portuguese writer Teolinda Gersão. The book makes us question the journal genre. However, the text itself questions the traditional notions of narrative, which are particular to the journal genre. In Os guarda-chuvas cintilantes there is the attempt to destroy linear temporality and create a new temporal measure, based on ludic themes, is also important in the book. The configuration of spatiality crosses time, becoming, therefore, mobile and unstable. There are in the book multiples spaces: a dream space, a material space and a symbolic space.

  19. Making space

    International Development Research Centre (IDRC) Digital Library (Canada)

    Karen Kershaw

    Making space an enquiry into women's participation in local politics in Rajasthan. Alice Albin Morris, Geeta Sharma and Arun Kumar. UNNATI Organisation for Development Education. India. Parallel Sessions II - Session B ...

  20. NASA Applications of Molecular Nanotechnology

    Science.gov (United States)

    Globus, Al; Bailey, David; Han, Jie; Jaffe, Richard; Levit, Creon; Merkle, Ralph; Srivastava, Deepak

    1998-01-01

    Laboratories throughout the world are rapidly gaining atomically precise control over matter. As this control extends to an ever wider variety of materials, processes and devices, opportunities for applications relevant to NASA's missions will be created. This document surveys a number of future molecular nanotechnology capabilities of aerospace interest. Computer applications, launch vehicle improvements, and active materials appear to be of particular interest. We also list a number of applications for each of NASA's enterprises. If advanced molecular nanotechnology can be developed, almost all of NASA's endeavors will be radically improved. In particular, a sufficiently advanced molecular nanotechnology can arguably bring large scale space colonization within our grasp.