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Sample records for block structures based

  1. Program structure-based blocking

    Science.gov (United States)

    Bertolli, Carlo; Eichenberger, Alexandre E.; O'Brien, John K.; Sura, Zehra N.

    2017-09-26

    Embodiments relate to program structure-based blocking. An aspect includes receiving source code corresponding to a computer program by a compiler of a computer system. Another aspect includes determining a prefetching section in the source code by a marking module of the compiler. Yet another aspect includes performing, by a blocking module of the compiler, blocking of instructions located in the prefetching section into instruction blocks, such that the instruction blocks of the prefetching section only contain instructions that are located in the prefetching section.

  2. Metal-oxide based nanoobjects: reactivity, building blocks for polymeric structures and structural variety

    International Nuclear Information System (INIS)

    Mueller, A.; Roy, S.

    2002-01-01

    The latest achievements in the new field of nanochemistry, i.e. investigation of reactions proceeding at selected sites of well-characterized metal-oxide based nanoobjects are reviewed. It is demonstrated that from the unique library of molybdenum-oxide based building blocks/fragments under reducing conditions in aqueous solution a huge variety of nanoobjects can be generated. Examples include the well-known molecular big-wheel of the type { Mo 176 } and big-ball of the type { Mo 132 } including their derivatives which are considered here. In addition, the by far largest structurally well-characterized cluster having 368 molybdenum atoms with the shape of a lemon is outlines and discussed [ru

  3. Structure-based ligand design for flexible proteins: Application of new F-DycoBlock

    Science.gov (United States)

    Zhu, Jiang; Fan, Hao; Liu, Haiyan; Shi, Yunyu

    2001-11-01

    A method of structure-based ligand design - DycoBlock - has been proposed and tested by Liu et al.[1]. It was further improved by Zhu et al. and applied to design new selective inhibitors of cyclooxygenase 2 [2]. In the current work, we present a new methodology - F-DycoBlock that allows for the incorporation of receptor flexibility. During the designing procedure, both the receptor and molecular building blocks are subjected to the multiple-copy stochastic molecular dynamics (MCSMD) simulation [1], while the protein moves in the mean field of all copies. It is tested for two enzymes studied previously - cyclooxygenase 2 (COX-2) and human immunodeficiency type 1 (HIV-1) protease. To identify the applicability of F-DycoBlock, the binding protein structure was used as starting point to explore the conformational space around the bound state. This method can be easily extended to accommodate the flexibility in different degree. Four types of treatment of the receptor flexibility - all-atom restrained, backbone restrained, intramolecular hydrogen-bond restrained and active-site flexible - were tested with or without the grid approximation. Two inhibitors, SC-558 for COX-2 and L700417 for HIV-1 protease, are used in this testing study for comparison with previous results. The accuracy of recovery, binding energy, solvent accessible surface area (SASA) and positional root-mean-square (RMS) deviation are used as criteria. The results indicate that F-DycoBlock is a robust methodology for flexible drug design. It is particularly notable that the protein flexibility has been perfectly associated with each stage of drug design - search for the binding sites, dynamic assembly and optimization of candidate compounds. When all protein atoms were restrained, F-DycoBlock yielded higher accuracy of recovery than DycoBlock (100%). If backbone atoms were restrained, the same ratio of accuracy was achieved. Moreover, with the intramolecular hydrogen bonds restrained, reasonable

  4. Comparative evaluation of structural integrity for ITER blanket shield block based on SDC-IC and ASME code

    Energy Technology Data Exchange (ETDEWEB)

    Shim, Hee-Jin [ITER Korea, National Fusion Research Institute, 169-148 Gwahak-Ro, Yuseong-Gu, Daejeon (Korea, Republic of); Ha, Min-Su, E-mail: msha12@nfri.re.kr [ITER Korea, National Fusion Research Institute, 169-148 Gwahak-Ro, Yuseong-Gu, Daejeon (Korea, Republic of); Kim, Sa-Woong; Jung, Hun-Chea [ITER Korea, National Fusion Research Institute, 169-148 Gwahak-Ro, Yuseong-Gu, Daejeon (Korea, Republic of); Kim, Duck-Hoi [ITER Organization, Route de Vinon sur Verdon - CS 90046, 13067 Sant Paul Lez Durance (France)

    2016-11-01

    Highlights: • The procedure of structural integrity and fatigue assessment was described. • Case studies were performed according to both SDC-IC and ASME Sec. • III codes The conservatism of the ASME code was demonstrated. • The study only covers the specifically comparable case about fatigue usage factor. - Abstract: The ITER blanket Shield Block is a bulk structure to absorb radiation and to provide thermal shielding to vacuum vessel and external vessel components, therefore the most significant load for Shield Block is the thermal load. In the previous study, the thermo-mechanical analysis has been performed under the inductive operation as representative loading condition. And the fatigue evaluations were conducted to assure structural integrity for Shield Block according to Structural Design Criteria for In-vessel Components (SDC-IC) which provided by ITER Organization (IO) based on the code of RCC-MR. Generally, ASME code (especially, B&PV Sec. III) is widely applied for design of nuclear components, and is usually well known as more conservative than other specific codes. For the view point of the fatigue assessment, ASME code is very conservative compared with SDC-IC in terms of the reflected K{sub e} factor, design fatigue curve and other factors. Therefore, an accurate fatigue assessment comparison is needed to measure of conservatism. The purpose of this study is to provide the fatigue usage comparison resulting from the specified operating conditions shall be evaluated for Shield Block based on both SDC-IC and ASME code, and to discuss the conservatism of the results.

  5. Block Tridiagonal Matrices in Electronic Structure Calculations

    DEFF Research Database (Denmark)

    Petersen, Dan Erik

    in the Landauer–Büttiker ballistic transport regime. These calculations concentrate on determining the so– called Green’s function matrix, or portions thereof, which is the inverse of a block tridiagonal general complex matrix. To this end, a sequential algorithm based on Gaussian elimination named Sweeps......This thesis focuses on some of the numerical aspects of the treatment of the electronic structure problem, in particular that of determining the ground state electronic density for the non–equilibrium Green’s function formulation of two–probe systems and the calculation of transmission...... is developed and compared to standard Gaussian elimination, where it is shown to be qualitatively quicker for the task of determining the block tridiagonal portion of the Green’s function matrix. The Sweep algorithm is then parallelized via a straightforward approach in order to enable moderate speedup...

  6. Block copolymer structures in nano-pores

    Science.gov (United States)

    Pinna, Marco; Guo, Xiaohu; Zvelindovsky, Andrei

    2010-03-01

    We present results of coarse-grained computer modelling of block copolymer systems in cylindrical and spherical nanopores on Cell Dynamics Simulation. We study both cylindrical and spherical pores and systematically investigate structures formed by lamellar, cylinders and spherical block copolymer systems for various pore radii and affinity of block copolymer blocks to the pore walls. The obtained structures include: standing lamellae and cylinders, ``onions,'' cylinder ``knitting balls,'' ``golf-ball,'' layered spherical, ``virus''-like and mixed morphologies with T-junctions and U-type defects [1]. Kinetics of the structure formation and the differences with planar films are discussed. Our simulations suggest that novel porous nano-containers can be formed by confining block copolymers in pores of different geometries [1,2]. [4pt] [1] M. Pinna, X. Guo, A.V. Zvelindovsky, Polymer 49, 2797 (2008).[0pt] [2] M. Pinna, X. Guo, A.V. Zvelindovsky, J. Chem. Phys. 131, 214902 (2009).

  7. High-resolution haplotype block structure in the cattle genome

    Directory of Open Access Journals (Sweden)

    Choi Jungwoo

    2009-04-01

    Full Text Available Abstract Background The Bovine HapMap Consortium has generated assay panels to genotype ~30,000 single nucleotide polymorphisms (SNPs from 501 animals sampled from 19 worldwide taurine and indicine breeds, plus two outgroup species (Anoa and Water Buffalo. Within the larger set of SNPs we targeted 101 high density regions spanning up to 7.6 Mb with an average density of approximately one SNP per 4 kb, and characterized the linkage disequilibrium (LD and haplotype block structure within individual breeds and groups of breeds in relation to their geographic origin and use. Results From the 101 targeted high-density regions on bovine chromosomes 6, 14, and 25, between 57 and 95% of the SNPs were informative in the individual breeds. The regions of high LD extend up to ~100 kb and the size of haplotype blocks ranges between 30 bases and 75 kb (10.3 kb average. On the scale from 1–100 kb the extent of LD and haplotype block structure in cattle has high similarity to humans. The estimation of effective population sizes over the previous 10,000 generations conforms to two main events in cattle history: the initiation of cattle domestication (~12,000 years ago, and the intensification of population isolation and current population bottleneck that breeds have experienced worldwide within the last ~700 years. Haplotype block density correlation, block boundary discordances, and haplotype sharing analyses were consistent in revealing unexpected similarities between some beef and dairy breeds, making them non-differentiable. Clustering techniques permitted grouping of breeds into different clades given their similarities and dissimilarities in genetic structure. Conclusion This work presents the first high-resolution analysis of haplotype block structure in worldwide cattle samples. Several novel results were obtained. First, cattle and human share a high similarity in LD and haplotype block structure on the scale of 1–100 kb. Second, unexpected

  8. Block-structured grids for Eulerian gyrokinetic simulations

    Science.gov (United States)

    Jarema, D.; Bungartz, H. J.; Görler, T.; Jenko, F.; Neckel, T.; Told, D.

    2016-01-01

    In order to predict the turbulent transport in magnetic fusion experiments, global (i.e., full-torus) gyrokinetic simulations are often carried out. In this context, one frequently encounters situations in which the plasma temperature varies by large factors across the radial simulation domain. In grid-based Eulerian codes, this enforces the use of a very large number of grid points in the two-dimensional velocity space, and, thus, an enormous computational effort. To minimize the computational requirements, one may employ block-structured grids, adapted to the radial changes of the temperature. As the block-structured grids rely on a general approach, they can be applied to different Eulerian gyrokinetic implementations. In this paper, we explain the construction and implementation of such grids in the gyrokinetic code GENE, F. Jenko et al. (2000), and present corresponding simulation results.

  9. Building blocks of Collagen based biomaterial devices

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. Building blocks of Collagen based biomaterial devices. Collagen as a protein. Collagen in tissues and organs. Stabilizing and cross linking agents. Immunogenicity. Hosts (drugs). Controlled release mechanisms of hosts. Biodegradability, workability into devices ...

  10. Block Tridiagonal Matrices in Electronic Structure Calculations

    DEFF Research Database (Denmark)

    Petersen, Dan Erik

    is developed and compared to standard Gaussian elimination, where it is shown to be qualitatively quicker for the task of determining the block tridiagonal portion of the Green’s function matrix. The Sweep algorithm is then parallelized via a straightforward approach in order to enable moderate speedup...... and memory distribution. The well known block cyclic reduction algorithm first developed by Gene Golub is then presented and analyzed for further expanding our parallel options, and finally a new hybrid method that combines block cyclic reduction and a form of Schur complement calculation is introduced....... The parallel algorithms are then benchmarked and the new hybrid method is shown to possess promising speedup characteristics for common cases of problems that need to be modeled....

  11. Chiral Block Copolymer Structures for Metamaterial Applications

    Science.gov (United States)

    2015-01-27

    elt @rice.edu Institution : Rice University Mailing Address : Department of...information from the molecular level to the micro and macrodomain levels. This joint work3 was published in the Journal of the American Chemical...Chirality from Molecule to Phase in Self‐Assembled Chiral Block Copolymers,” Journal of the American Chemical Society, 134 (26), 10974 – 10986, (2012).

  12. Efficient Eulerian gyrokinetic simulations with block-structured grids

    Energy Technology Data Exchange (ETDEWEB)

    Jarema, Denis

    2017-01-20

    Gaining a deep understanding of plasma microturbulence is of paramount importance for the development of future nuclear fusion reactors, because it causes a strong outward transport of heat and particles. Gyrokinetics has proven itself as a valid mathematical model to simulate such plasma microturbulence effects. In spite of the advantages of this model, nonlinear radially extended (or global) gyrokinetic simulations are still extremely computationally expensive, involving a very large number of computational grid points. Hence, methods that reduce the number of grid points without a significant loss of accuracy are a prerequisite to be able to run high-fidelity simulations. At the level of the mathematical model, the gyrokinetic approach achieves a reduction from six to five coordinates in comparison to the fully kinetic models. This reduction leads to an important decrease in the total number of computational grid points. However, the velocity space mixed with the radial direction still requires a very fine resolution in grid based codes, due to the disparities in the thermal speed, which are caused by a strong temperature variation along the radial direction. An attempt to address this problem by modifying the underlying gyrokinetic set of equations leads to additional nonlinear terms, which are the most expensive parts to simulate. Furthermore, because of these modifications, well-established and computationally efficient implementations developed for the original set of equations can no longer be used. To tackle such issues, in this thesis we introduce an alternative approach of blockstructured grids. This approach reduces the number of grid points significantly, but without changing the underlying mathematical model. Furthermore, our technique is minimally invasive and allows the reuse of a large amount of already existing code using rectilinear grids, modifications being necessary only on the block boundaries. Moreover, the block-structured grid can be

  13. Electrically Tunable Soft-Solid Block Copolymer Structural Color.

    Science.gov (United States)

    Park, Tae Joon; Hwang, Sun Kak; Park, Sungmin; Cho, Sung Hwan; Park, Tae Hyun; Jeong, Beomjin; Kang, Han Sol; Ryu, Du Yeol; Huh, June; Thomas, Edwin L; Park, Cheolmin

    2015-12-22

    One-dimensional photonic crystals based on the periodic stacking of two different dielectric layers have been widely studied, but the fabrication of mechanically flexible polymer structural color (SC) films, with electro-active color switching, remains challenging. Here, we demonstrate free-standing electric field tunable ionic liquid (IL) swollen block copolymer (BCP) films. Placement of a polymer/ionic liquid film-reservoir adjacent to a self-assembled poly(styrene-block-quaternized 2-vinylpyridine) (PS-b-QP2VP) copolymer SC film allowed the development of red (R), green (G), and blue (B) full-color SC block copolymer films by swelling of the QP2VP domains by the ionic liquid associated with water molecules. The IL-polymer/BCP SC film is mechanically flexible with excellent color stability over several days at ambient conditions. The selective swelling of the QP2VP domains could be controlled by both the ratio of the IL to a polymer in the gel-like IL reservoir layer and by an applied voltage in the range of -3 to +6 V using a metal/IL reservoir/SC film/IL reservoir/metal capacitor type device.

  14. Probabilistic Decision Based Block Partitioning for Future Video Coding

    KAUST Repository

    Wang, Zhao

    2017-11-29

    In the latest Joint Video Exploration Team development, the quadtree plus binary tree (QTBT) block partitioning structure has been proposed for future video coding. Compared to the traditional quadtree structure of High Efficiency Video Coding (HEVC) standard, QTBT provides more flexible patterns for splitting the blocks, which results in dramatically increased combinations of block partitions and high computational complexity. In view of this, a confidence interval based early termination (CIET) scheme is proposed for QTBT to identify the unnecessary partition modes in the sense of rate-distortion (RD) optimization. In particular, a RD model is established to predict the RD cost of each partition pattern without the full encoding process. Subsequently, the mode decision problem is casted into a probabilistic framework to select the final partition based on the confidence interval decision strategy. Experimental results show that the proposed CIET algorithm can speed up QTBT block partitioning structure by reducing 54.7% encoding time with only 1.12% increase in terms of bit rate. Moreover, the proposed scheme performs consistently well for the high resolution sequences, of which the video coding efficiency is crucial in real applications.

  15. Block-Matching Based Multifocus Image Fusion

    Directory of Open Access Journals (Sweden)

    Feng Zhu

    2015-01-01

    Full Text Available A new multifocus image fusion method is proposed. Two image blocks are selected by sliding the window from the two source images at the same position, discrete cosine transform (DCT is implemented, respectively, on these two blocks, and the alternating component (AC energy of these blocks is then calculated to decide which is the well-focused one. In addition, block matching is used to determine a group of image blocks that are all similar to the well-focused reference block. Finally, all the blocks are returned to their original positions through weighted average. The weight is decided with the AC energy of the well-focused block. Experimental results demonstrate that, unlike other spatial methods, the proposed method effectively avoids block artifacts. The proposed method also significantly improves the objective evaluation results, which are obtained by some transform domain methods.

  16. Poly(phenylene ether Based Amphiphilic Block Copolymers

    Directory of Open Access Journals (Sweden)

    Edward N. Peters

    2017-09-01

    Full Text Available Polyphenylene ether (PPE telechelic macromonomers are unique hydrophobic polyols which have been used to prepare amphiphilic block copolymers. Various polymer compositions have been synthesized with hydrophilic blocks. Their macromolecular nature affords a range of structures including random, alternating, and di- and triblock copolymers. New macromolecular architectures can offer tailored property profiles for optimum performance. Besides reducing moisture uptake and making the polymer surface more hydrophobic, the PPE hydrophobic segment has good compatibility with polystyrene (polystyrene-philic. In general, the PPE contributes to the toughness, strength, and thermal performance. Hydrophilic segments go beyond their affinity for water. Improvements in the interfacial adhesion between polymers and polar substrates via hydrogen bonding and good compatibility with polyesters (polyester-philic have been exhibited. The heterogeneity of domains in these PPE based block copolymer offers important contributions to diverse applications.

  17. Patchy micelles based on coassembly of block copolymer chains and block copolymer brushes on silica particles.

    Science.gov (United States)

    Zhu, Shuzhe; Li, Zhan-Wei; Zhao, Hanying

    2015-04-14

    Patchy particles are a type of colloidal particles with one or more well-defined patches on the surfaces. The patchy particles with multiple compositions and functionalities have found wide applications from the fundamental studies to practical uses. In this research patchy micelles with thiol groups in the patches were prepared based on coassembly of free block copolymer chains and block copolymer brushes on silica particles. Thiol-terminated and cyanoisopropyl-capped polystyrene-block-poly(N-isopropylacrylamide) block copolymers (PS-b-PNIPAM-SH and PS-b-PNIPAM-CIP) were synthesized by reversible addition-fragmentation chain transfer polymerization and chemical modifications. Pyridyl disulfide-functionalized silica particles (SiO2-SS-Py) were prepared by four-step surface chemical reactions. PS-b-PNIPAM brushes on silica particles were prepared by thiol-disulfide exchange reaction between PS-b-PNIPAM-SH and SiO2-SS-Py. Surface micelles on silica particles were prepared by coassembly of PS-b-PNIPAM-CIP and block copolymer brushes. Upon cleavage of the surface micelles from silica particles, patchy micelles with thiol groups in the patches were obtained. Dynamic light scattering, transmission electron microscopy, and zeta-potential measurements demonstrate the preparation of patchy micelles. Gold nanoparticles can be anchored onto the patchy micelles through S-Au bonds, and asymmetric hybrid structures are formed. The thiol groups can be oxidized to disulfides, which results in directional assembly of the patchy micelles. The self-assembly behavior of the patchy micelles was studied experimentally and by computer simulation.

  18. Structuring oil by protein building blocks

    NARCIS (Netherlands)

    Vries, de Auke

    2017-01-01

    Over the recent years, structuring of oil into ‘organogels’ or ‘oleogels’ has gained much attention amongst colloid-, material,- and food scientists. Potentially, these oleogels could be used as an alternative for saturated- and trans fats in food products. To develop

  19. Formation and structural properties of multi-block copolymer vesicles

    Science.gov (United States)

    Wang, Rong; Ma, Shiying

    2014-03-01

    Due to the unique structure, vesicles have attracted considerable attention for their potential applications, such as gene and drug delivery, microcapsules, nanoreactors, cell membrane mimetic, synthetic organelles, etc. By using dissipative particle dynamics, we studied the self-assembly of amphiphilic multi-block copolymer. The phase diagram was constructed by varying the interaction parameters and the composition of the block copolymers. The results show that the vesicles are stable in a large region which is different from the diblock copolymer or triblock copolymer. The structural properties of vesicles can be controlled by varying the interaction parameters and the length of the hydrophobic block. The relationship between the hydrophilic and hydrophobic block length vs the aqueous cavity size and vesicle size are revealed. The copolymers with shorter hydrophobic blocks length or the higher hydrophilicity are more likely to form vesicles with larger aqueous cavity size and vesicle size as well as thinner wall thickness. However, the increase in hydrophobic-block length results to form vesicles with smaller aqueous cavity size and larger vesicle size. Acknowledgments. This work has been supported by NNSFC (No. 21074053) and NBRPC (No. 2010CB923303).

  20. Ground reaction curve based upon block theory

    International Nuclear Information System (INIS)

    Yow, J.L. Jr.; Goodman, R.E.

    1985-09-01

    Discontinuities in a rock mass can intersect an excavation surface to form discrete blocks (keyblocks) which can be unstable. Once a potentially unstable block is identified, the forces affecting it can be calculated to assess its stability. The normal and shear stresses on each block face before displacement are calculated using elastic theory and are modified in a nonlinear way by discontinuity deformations as the keyblock displaces. The stresses are summed into resultant forces to evaluate block stability. Since the resultant forces change with displacement, successive increments of block movement are examined to see whether the block ultimately becomes stable or fails. Two-dimensional (2D) and three-dimensional (3D) analytic models for the stability of simple pyramidal keyblocks were evaluated. Calculated stability is greater for 3D analyses than for 2D analyses. Calculated keyblock stability increases with larger in situ stress magnitudes, larger lateral stress ratios, and larger shear strengths. Discontinuity stiffness controls blocks displacement more strongly than it does stability itself. Large keyblocks are less stable than small ones, and stability increases as blocks become more slender

  1. Hardware realization of chaos based block cipher for image encryption

    KAUST Repository

    Barakat, Mohamed L.

    2011-12-01

    Unlike stream ciphers, block ciphers are very essential for parallel processing applications. In this paper, the first hardware realization of chaotic-based block cipher is proposed for image encryption applications. The proposed system is tested for known cryptanalysis attacks and for different block sizes. When implemented on Virtex-IV, system performance showed high throughput and utilized small area. Passing successfully in all tests, our system proved to be secure with all block sizes. © 2011 IEEE.

  2. Blocking Detection Based on Synoptic Filters

    Directory of Open Access Journals (Sweden)

    Bernd Schalge

    2011-01-01

    minimum zonal width, and (iii a persistence filter to extract events with a minimum duration. Practical filter application is analysed in two case studies and the blocking climatologies for the Northern and the Southern Hemisphere.

  3. Nanostructured Polysulfone-Based Block Copolymer Membranes

    KAUST Repository

    Xie, Yihui

    2016-05-01

    The aim of this work is to fabricate nanostructured membranes from polysulfone-based block copolymers through self-assembly and non-solvent induced phase separation. Block copolymers containing polysulfone are novel materials for this purpose providing better mechanical and thermal stability to membranes than polystyrene-based copolymers, which have been exclusively used now. Firstly, we synthesized a triblock copolymer, poly(tert-butyl acrylate)-b-polsulfone-b-poly(tert-butyl acrylate) through polycondensation and reversible addition-fragmentation chain-transfer polymerization. The obtained membrane has a highly porous interconnected skin layer composed of elongated micelles with a flower-like arrangement, on top of the graded finger-like macrovoids. Membrane surface hydrolysis was carried out in a combination with metal complexation to obtain metal-chelated membranes. The copper-containing membrane showed improved antibacterial capability. Secondly, a poly(acrylic acid)-b-polysulfone-b-poly(acrylic acid) triblock copolymer obtained by hydrolyzing poly(tert-butyl acrylate)-b-polsulfone-b-poly(tert-butyl acrylate) formed a thin film with cylindrical poly(acrylic acid) microdomains in polysulfone matrix through thermal annealing. A phase inversion membrane was prepared from the same polymer via self-assembly and chelation-assisted non-solvent induced phase separation. The spherical micelles pre-formed in a selective solvent mixture packed into an ordered lattice in aid of metal-poly(acrylic acid) complexation. The space between micelles was filled with poly(acrylic acid)-metal complexes acting as potential water channels. The silver0 nanoparticle-decorated membrane was obtained by surface reduction, having three distinct layers with different particle sizes. Other amphiphilic copolymers containing polysulfone and water-soluble segments such as poly(ethylene glycol) and poly(N-isopropylacrylamide) were also synthesized through coupling reaction and copper0-mediated

  4. Multigrid technique and Optimized Schwarz method on block-structured grids with discontinuous interfaces

    DEFF Research Database (Denmark)

    Kolmogorov, Dmitry; Sørensen, Niels N.; Shen, Wen Zhong

    2013-01-01

    An Optimized Schwarz method using Robin boundary conditions for relaxation scheme is presented in the frame of Multigrid method on discontinuous grids. At each iteration the relaxation scheme is performed in two steps: one step with Dirichlet and another step with Robin boundary conditions at inner...... block boundaries. A Robin parameter that depends on grid geometry and grid discontinuity at block interfaces is introduced. The general solution algorithm is based on SIMPLE method and a conservative _nite-volume scheme on block-structured grids with discontinuous interfaces. The multigrid method...

  5. Printable and Rewritable Full Block Copolymer Structural Color.

    Science.gov (United States)

    Kang, Han Sol; Lee, Jinseong; Cho, Suk Man; Park, Tae Hyun; Kim, Min Ju; Park, Chanho; Lee, Seung Won; Kim, Kang Lib; Ryu, Du Yeol; Huh, June; Thomas, Edwin L; Park, Cheolmin

    2017-08-01

    Structural colors (SCs) of photonic crystals (PCs) arise from selective constructive interference of incident light. Here, an ink-jet printable and rewritable block copolymer (BCP) SC display is demonstrated, which can be quickly written and erased over 50 times with resolution nearly equivalent to that obtained with a commercial office ink-jet printer. Moreover, the writing process employs an easily modified printer for position- and concentration-controlled deposition of a single, colorless, water-based ink containing a reversible crosslinking agent, ammonium persulfate. Deposition of the ink onto a self-assembled BCP PC film comprising a 1D stack of alternating layers enables differential swelling of the written BCP film and produces a full-colored SC display of characters and images. Furthermore, the information can be readily erased and the system can be reset by application of hydrogen bromide. Subsequently, new information can be rewritten, resulting in a chemically rewritable BCP SC display. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Robust and Adaptive Block Tracking Method Based on Particle Filter

    Directory of Open Access Journals (Sweden)

    Bin Sun

    2015-10-01

    Full Text Available In the field of video analysis and processing, object tracking is attracting more and more attention especially in traffic management, digital surveillance and so on. However problems such as objects’ abrupt motion, occlusion and complex target structures would bring difficulties to academic study and engineering application. In this paper, a fragmentsbased tracking method using the block relationship coefficient is proposed. In this method, we use particle filter algorithm and object region is divided into blocks initially. The contribution of this method is that object features are not extracted just from a single block, the relationship between current block and its neighbor blocks are extracted to describe the variation of the block. Each block is weighted according to the block relationship coefficient when the block is voted on the most matched region in next frame. This method can make full use of the relationship between blocks. The experimental results demonstrate that our method can provide good performance in condition of occlusion and abrupt posture variation.

  7. Fabrication of calcite blocks from gypsum blocks by compositional transformation based on dissolution-precipitation reactions in sodium carbonate solution.

    Science.gov (United States)

    Ishikawa, Kunio; Kawachi, Giichiro; Tsuru, Kanji; Yoshimoto, Ayami

    2017-03-01

    Calcium carbonate (CaCO 3 ) has been used as a bone substitute, and is a precursor for carbonate apatite, which is also a promising bone substitute. However, limited studies have been reported on the fabrication of artificial calcite blocks. In the present study, cylindrical calcite blocks (ϕ6×3mm) were fabricated by compositional transformation based on dissolution-precipitation reactions using different calcium sulfate blocks as a precursor. In the dissolution-precipitation reactions, both CaSO 4 ·2H 2 O and CaSO 4 transformed into calcite, a polymorph of CaCO 3 , while maintaining their macroscopic structure when immersed in 1mol/L Na 2 CO 3 solution at 80°C for 1week. The diametral tensile strengths of the calcite blocks formed using CaSO 4 ·2H 2 O and CaSO 4 were 1.0±0.3 and 2.3±0.7MPa, respectively. The fabrication of calcite blocks using CaSO 4 ·2H 2 O and CaSO 4 proposed in this investigation may be a useful method to produce calcite blocks because of the self-setting ability and high temperature stability of gypsum precursors. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. A Block Compressive Sensing Based Scalable Encryption Framework for Protecting Significant Image Regions

    Science.gov (United States)

    Zhang, Yushu; Zhou, Jiantao; Chen, Fei; Zhang, Leo Yu; Xiao, Di; Chen, Bin; Liao, Xiaofeng

    The existing Block Compressive Sensing (BCS) based image ciphers adopted the same sampling rate for all the blocks, which may lead to the desirable result that after subsampling, significant blocks lose some more-useful information while insignificant blocks still retain some less-useful information. Motivated by this observation, we propose a scalable encryption framework (SEF) based on BCS together with a Sobel Edge Detector and Cascade Chaotic Maps. Our work is firstly dedicated to the design of two new fusion techniques, chaos-based structurally random matrices and chaos-based random convolution and subsampling. The basic idea is to divide an image into some blocks with an equal size and then diagnose their respective significance with the help of the Sobel Edge Detector. For significant block encryption, chaos-based structurally random matrix is applied to significant blocks whereas chaos-based random convolution and subsampling are responsible for the remaining insignificant ones. In comparison with the BCS based image ciphers, the SEF takes lightweight subsampling and severe sensitivity encryption for the significant blocks and severe subsampling and lightweight robustness encryption for the insignificant ones in parallel, thus better protecting significant image regions.

  9. Structural analysis of ceramic blocks sealing or structural incorporated with the industrial laundry sludge

    International Nuclear Information System (INIS)

    Almeida, P.H.S.; Grippe, V.Y.Q.; Goulart, J.V.

    2016-01-01

    Industrial and commercial development of recent decades has led to an increase in waste generation. Thus, it is necessary to develop alternative and effective methods of treatment, replacing the simple disposal of these wastes in landfills. The objective of this work is to study the incorporation of textile industrial laundries sludge in ceramic blocks sealing or structural. Samples of ceramic blocks were produced using formulation with 20% sludge, the mass of ceramic clay. Structural analysis of the block was observed the tendency of most empty emergence (pores) during the firing of the blocks, as textile sludge was added in the ceramic paste composition. The mechanical testing of blocks compressive strength was above the minimum 3.0 MPa specified by the standard limit. The physical test water absorption of the blocks was within the range 8 to 22% specified by the standard. (author)

  10. Biomimetic synthesis of ordered silica structures mediated by block copolypeptides.

    Science.gov (United States)

    Cha, J N; Stucky, G D; Morse, D E; Deming, T J

    2000-01-20

    In biological systems such as diatoms and sponges, the formation of solid silica structures with precisely controlled morphologies is directed by proteins and polysaccharides and occurs in water at neutral pH and ambient temperature. Laboratory methods, in contrast, have to rely on extreme pH conditions and/or surfactants to induce the condensation of silica precursors into specific morphologies or patterned structures. This contrast in processing conditions and the growing demand for benign synthesis methods that minimize adverse environmental effects have spurred much interest in biomimetic approaches in materials science. The recent demonstration that silicatein-a protein found in the silica spicules of the sponge Tethya aurantia--can hydrolyse and condense the precursor molecule tetraethoxysilane to form silica structures with controlled shapes at ambient conditions seems particularly promising in this context. Here we describe synthetic cysteine-lysine block copolypeptides that mimic the properties of silicatein: the copolypeptides self-assemble into structured aggregates that hydrolyse tetraethoxysilane while simultaneously directing the formation of ordered silica morphologies. We find that oxidation of the cysteine sulphydryl groups, which is known to affect the assembly of the block copolypeptide, allows us to produce different structures: hard silica spheres and well-defined columns of amorphous silica are produced using the fully reduced and the oxidized forms of the copolymer, respectively.

  11. Modification of nanofibrillated cellulose using amphiphilic block-structured galactoglucomannans.

    Science.gov (United States)

    Lozhechnikova, Alina; Dax, Daniel; Vartiainen, Jari; Willför, Stefan; Xu, Chunlin; Österberg, Monika

    2014-09-22

    Nanofibrillated cellulose (NFC) and hemicelluloses have shown to be highly promising renewable components both as barrier materials and in novel biocomposites. However, the hydrophilic nature of these materials restricts their use in some applications. In this work, the usability of modified O-acetyl galactoglucomannan (GGM) for modification of NFC surface properties was studied. Four GGM-block-structured, amphiphilic derivatives were synthesized using either fatty acids or polydimethylsiloxane as hydrophobic tails. The adsorption of these GGM derivatives was consecutively examined in aqueous solution using a quartz crystal microbalance with dissipation monitoring (QCM-D). It was found that the hydrophobic tails did not hinder adsorption of the GGM derivatives to cellulose, which was concluded to be due to the presence of the native GGM-block with high affinity to cellulose. The layer properties of the adsorbed block-co-polymers were discussed and evaluated. Self-standing NFC films were further prepared and coated with the GGM derivatives and the effect of the surface modification on wetting properties and oxygen permeability (OP) of the modified films was assessed. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Swarm intelligence algorithm for interconnect model order reduction with sub-block structure preserving

    Science.gov (United States)

    Wang, Xinsheng; Wang, Chenxu; Yu, Mingyan

    2016-07-01

    In this paper, we propose a generalised sub-block structure preservation interconnect model order reduction (MOR) technique based on the swarm intelligence method, that is, particle swarm optimisation (PSO). The swarm intelligence-based structure preservation MOR can be used for a standard model as a criterion for different structure preservation interconnect MOR methods. In the proposed technique, the PSO method is used for predicting the unknown elements of structure-preserving reduced-order modelling of interconnect circuits. The prediction is based on minimising the difference of transform function between the original full-order and desired reduced-order systems maintaining the full-order structure in the reduced-order model. The proposed swarm-intelligence-based structure-preserving MOR method is compared with published work on structure preservation MOR SPRIM techniques. Simulation and synthesis results verify the accuracy and validity of the new structure-preserving MOR technique.

  13. Nonoverlapping Blocks Based Copy-Move Forgery Detection

    Directory of Open Access Journals (Sweden)

    Yu Sun

    2018-01-01

    Full Text Available In order to solve the problem of high computational complexity in block-based methods for copy-move forgery detection, we divide image into texture part and smooth part to deal with them separately. Keypoints are extracted and matched in texture regions. Instead of using all the overlapping blocks, we use nonoverlapping blocks as candidates in smooth regions. Clustering blocks with similar color into a group can be regarded as a preprocessing operation. To avoid mismatching due to misalignment, we update candidate blocks by registration before projecting them into hash space. In this way, we can reduce computational complexity and improve the accuracy of matching at the same time. Experimental results show that the proposed method achieves better performance via comparing with the state-of-the-art copy-move forgery detection algorithms and exhibits robustness against JPEG compression, rotation, and scaling.

  14. Two innovative solutions based on fibre concrete blocks designed for building substructure

    Science.gov (United States)

    Pazderka, J.; Hájek, P.

    2017-09-01

    Using of fibers in a high-strength concrete allows reduction of the dimensions of small precast concrete elements, which opens up new ways of solution for traditional construction details in buildings. The paper presents two innovative technical solutions for building substructure: The special shaped plinth block from fibre concrete and the fibre concrete elements for new technical solution of ventilated floor. The main advantages of plinth block from fibre concrete blocks (compared with standard plinth solutions) is: easier and faster assembly, higher durability and thanks to the air cavity between the vertical part of the block, the building substructure reduced moisture level of structures under the waterproofing layer and a comprehensive solution to the final surface of building plinth as well as the surface of adjacent terrain. The ventilated floor based on fibre concrete precast blocks is an attractive structural alternative for tackling the problem of increased moisture in masonry in older buildings, lacking a functional waterproof layer in the substructure.

  15. Assessment of Structural Strength of Commercial Sandcrete Blocks ...

    African Journals Online (AJOL)

    makorede

    blocks which describes solid, hollow and cellular blocks: See. Table 1. Type. Void percent of total volume. Solid ... also deals with solid bricks, hollow bricks and cellular bricks. It states that the minimum requirement for blocks ..... bricks and blocks of fired brick earth, clay or shale. Ejeh, S. P. (1982). Comparative strength of ...

  16. Multi Modal Face Recognition Using Block Based Curvelet Features

    OpenAIRE

    K, Jyothi; J, Prabhakar C.

    2014-01-01

    In this paper, we present multimodal 2D +3D face recognition method using block based curvelet features. The 3D surface of face (Depth Map) is computed from the stereo face images using stereo vision technique. The statistical measures such as mean, standard deviation, variance and entropy are extracted from each block of curvelet subband for both depth and intensity images independently.In order to compute the decision score, the KNN classifier is employed independently for both intensity an...

  17. A novel block cryptosystem based on iterating a chaotic map

    International Nuclear Information System (INIS)

    Xiang Tao; Liao Xiaofeng; Tang Guoping; Chen Yong; Wong, Kwok-wo

    2006-01-01

    A block cryptographic scheme based on iterating a chaotic map is proposed. With random binary sequences generated from the real-valued chaotic map, the plaintext block is permuted by a key-dependent shift approach and then encrypted by the classical chaotic masking technique. Simulation results show that performance and security of the proposed cryptographic scheme are better than those of existing algorithms. Advantages and security of our scheme are also discussed in detail

  18. Ship Block Transportation Scheduling Problem Based on Greedy Algorithm

    Directory of Open Access Journals (Sweden)

    Chong Wang

    2016-05-01

    Full Text Available Ship block transportation problems are crucial issues to address in reducing the construction cost and improving the productivity of shipyards. Shipyards aim to maximize the workload balance of transporters with time constraint such that all blocks should be transported during the planning horizon. This process leads to three types of penalty time: empty transporter travel time, delay time, and tardy time. This study aims to minimize the sum of the penalty time. First, this study presents the problem of ship block transportation with the generalization of the block transportation restriction on the multi-type transporter. Second, the problem is transformed into the classical traveling salesman problem and assignment problem through a reasonable model simplification and by adding a virtual node to the proposed directed graph. Then, a heuristic algorithm based on greedy algorithm is proposed to assign blocks to available transporters and sequencing blocks for each transporter simultaneously. Finally, the numerical experiment method is used to validate the model, and its result shows that the proposed algorithm is effective in realizing the efficient use of the transporters in shipyards. Numerical simulation results demonstrate the promising application of the proposed method to efficiently improve the utilization of transporters and to reduce the cost of ship block logistics for shipyards.

  19. Structural, compositional, thermal resistant and hydro-oleophobic properties of fluorine based block-co-polymer films on quartz substrates by wet chemical process

    Science.gov (United States)

    Phani, A. R.; Passacantando, M.; Santucci, S.

    2006-08-01

    Crack free and smooth surfaces of poly [4,5-difluoro 2,2-bis (trifluoromethyl)-(1,3 dioxole)-co-tetrafluoroethylene] (TFE-co-TFD) thin films have been deposited by wet chemical dip coating technique on polished quartz and glass slide substrates. The deposited films have been subjected to annealing at different temperatures ranging from 100 to 500 °C for 1 h in argon atmosphere. The elemental composition of the as-deposited (xerogel) thin film as well as film annealed at 400 °C was measured by X-ray photoelectron spectroscopy and observed that there was no change in the composition of the film. X-ray diffraction pattern revealed the amorphous behaviour of both as-deposited and film annealed at 400 °C. Surface morphology and elemental composition of the films have been examined by employing scanning electron microscopy attached with energy dispersive X-ray analyser, respectively. It was found that as the annealing temperature increased from 100 to 400 °C, nano-hemisphere-like structures have been grown, which in turn has shown increase in the water contact angle from 122o to 148o and oil (peanut) contact angle from 85° to 96°. No change in the water contact angle (122°) has been observed when the films deposited at room temperature were heated in air from 30 to 80 °C as well as exposed to steam for 8 days for 8 h/day indicating thermal stability of the film.

  20. Study of the block/grout interface in concrete and clay block masonry structures

    Directory of Open Access Journals (Sweden)

    O. S. Izquierdo

    Full Text Available ABSTRACT This work aims to study the behavior of the block/grout interface for concrete and clay block masonry. This was achieved by push-out and pull-out experimental tests including reinforcement bar in the latter one. The experimental result showed that there is a good bond between the concrete blocks internal faces and the grout, enough to prevent infill-slippage, and that the whole tensile strength of the usual reinforcement bars is achieved provided they are properly anchored. Nevertheless, for clay blocks there is a low bond between the clay blocks internal faces and the grout, allowing the infill-slippage before the reinforcement bars reach their yield stress.

  1. An ICP algorithm based on block path closest point search

    Science.gov (United States)

    Wang, Kuisheng; Li, Xing; Lei, Hongwei; Zhang, Xiaorui

    2017-08-01

    At present, the traditional ICP algorithm has the problems of low efficiency and low precision. To solve these two problems, an ICP algorithm based on block path closest point search is proposed in this paper. The idea of the algorithm is as follows: firstly, the point cloud data is divided into blocks, and the nearest point block corresponding to the target point cloud is searched by the path method. Secondly, according to the global method, the nearest point can be determined only by finding the nearest point block, and complete all the closest match. The experimental results show that the improved ICP algorithm has faster speed and higher precision than the traditional ICP algorithm, for a large number of point cloud data advantage is more obvious.

  2. Crustal Structure, Seismic Anisotropy and Deformations of the Ediacaran/Cambrian of the Małopolska Block in SE Poland Based on Data from Two Seismic Wide-Angle Experiments

    Science.gov (United States)

    Środa, Piotr

    2017-04-01

    The area of SE Poland represents a complex contact of tectonic units of different consolidation age—from the Precambrian East European Craton, through Palaeozoic West European Platform (including Małopolska Block) to Cenozoic Carpathians and Carpathian Foredeep. In order to investigate the anisotropic properties of the upper crust of the Małopolska Block and their relation to tectonic evolution of the area, two seismic datasets were used: seismic wide-angle off-line recordings from POLCRUST-01 deep seismic reflection profile and recordings from active deep seismic experiment CELEBRATION 2000. During acquisition of deep reflection seismic profile POLCRUST-01 in 2010, a 35-km-long line of 14 recorders (PA-14), oriented perpendicularly to the profile, was deployed to record the refractions from the upper crust (Pg) at wide range of azimuths. These data were used for an analysis of the azimuthal anisotropy of the MB with the modified delay-time inversion method. The results of modelling of the off-line refractions from the MB suggest 6% HTI anisotropy of the Cambrian/Ediacaran basement, with 130º azimuth of the fast velocity axis and mean Vp of 4.9 km/s. To compare this result with previous, independent information about anisotropy at larger depth, a subset of previously modelled data from CELEBRATION 2000 experiment, recorded in the MB area, was also analysed by inversion. The recordings of Pg phase at up to 120 km offsets were analysed using anisotropic delay-time inversion, providing information down to 12 km depth. The CELEBRATION 2000 model shows 9% HTI anisotropy with 126º orientation of the fast axis. Thus, local-scale anisotropy of this part of MB confirms the large-scale anisotropy suggested by previous studies based on data from a broader area and larger depth interval. The azimuthal anisotropy (i.e. HTI symmetry of the medium) is interpreted as a result of strong compressional deformation during the accretion of terranes to the EEC margin, leading to

  3. Flexible Triangle Search Algorithm for Block-Based Motion Estimation

    Directory of Open Access Journals (Sweden)

    Andreas Antoniou

    2007-01-01

    Full Text Available A new fast algorithm for block-based motion estimation, the flexible triangle search (FTS algorithm, is presented. The algorithm is based on the simplex method of optimization adapted to an integer grid. The proposed algorithm is highly flexible due to its ability to quickly change its search direction and to move towards the target of the search criterion. It is also capable of increasing or decreasing its search step size to allow coarser or finer search. Unlike other fast search algorithms, the FTS can escape from inferior local minima and thus converge to better solutions. The FTS was implemented as part of the H.264 encoder and was compared with several other block matching algorithms. The results obtained show that the FTS can reduce the number of block matching comparisons by around 30–60% with negligible effect on the image quality and compression ratio.

  4. Block-structured grids in full velocity space for Eulerian gyrokinetic simulations

    Science.gov (United States)

    Jarema, D.; Bungartz, H. J.; Görler, T.; Jenko, F.; Neckel, T.; Told, D.

    2017-06-01

    Global, i.e., full-torus, gyrokinetic simulations play an important role in exploring plasma microturbulence in magnetic fusion devices with strong radial variations. In the presence of steep temperature profiles, grid-based Eulerian approaches can become quite challenging as the correspondingly varying velocity space structures need to be accommodated and sufficiently resolved. A rigid velocity space grid then requires a very high number of discretization nodes resulting in enormous computational costs. To tackle this issue and reduce the computational demands, we introduce block-structured grids in the all velocity space dimensions. The construction of these grids is based on a general approach, making them suitable for various Eulerian implementations. In the current study, we explain the rationale behind the presented approach, detail the implementation, and provide simulation results obtained with the block-structured grids. The achieved reduction in the number of computational nodes depends on the temperature profile and simulation scenario provided. In the test cases at hand, about ten times fewer grid points are required for nonlinear simulations performed with block-structured grids in the plasma turbulence code GENE (http://genecode.org). With the speed-up found to scale almost exactly reciprocal to the number of grid points, the new implementation greatly reduces the computational costs and therefore opens new possibilities for applications of this software package.

  5. Optimizing block-based maintenance under random machine usage

    NARCIS (Netherlands)

    de Jonge, Bram; Jakobsons, Edgars

    Existing studies on maintenance optimization generally assume that machines are either used continuously, or that times until failure do not depend on the actual usage. In practice, however, these assumptions are often not realistic. In this paper, we consider block-based maintenance optimization

  6. Compound La[B5O8(OH)2] with a new type of pentaborate layer based on the 5[3T + 2Δ] block: Topology-symmetry analysis and the position in the structural system

    International Nuclear Information System (INIS)

    Ivanova, A. G.; Belokoneva, E. L.; Dimitrova, O. V.; Mochenova, N. N.

    2006-01-01

    Crystals of a new rare-earth borate, LaB 5 O 8 (OH) 2 (space group P2 1 /n), are synthesized under hydrothermal conditions. The crystal structure is determined by the heavy-atom method without prior knowledge of the chemical formula. The radical anion is a layer composed of pentaborate blocks 5[3T + 2Δ]. The topological and symmetric patterns of their condensation differ from those observed in all known layered pentaborates containing the same block. The building blocks are shared by vertices of tetrahedra to form chains. These chains are joined into a corrugated layer in such a way that one of the BO 3 triangles of the building block is terminal and the layer itself is denser than those previously revealed in all other borates. In contrast to the majority of layer borates, the new La borate does not contain water molecules, because it crystallizes from more concentrated solutions. The La atoms are located inside the walls of the hollows of corrugated layers, thus centering the holes of the layers

  7. Center of Mass-Based Adaptive Fast Block Motion Estimation

    Directory of Open Access Journals (Sweden)

    Yeh Kuo-Liang

    2007-01-01

    Full Text Available This work presents an efficient adaptive algorithm based on center of mass (CEM for fast block motion estimation. Binary transform, subsampling, and horizontal/vertical projection techniques are also proposed. As the conventional CEM calculation is computationally intensive, binary transform and subsampling approaches are proposed to simplify CEM calculation; the binary transform center of mass (BITCEM is then derived. The BITCEM motion types are classified by percentage of (0,0 BITCEM motion vectors. Adaptive search patterns are allocated according to the BITCEM moving direction and the BITCEM motion type. Moreover, the BITCEM motion vector is utilized as the initial search point for near-still or slow BITCEM motion types. To support the variable block sizes, the horizontal/vertical projections of a binary transformed macroblock are utilized to determine whether the block requires segmentation. Experimental results indicate that the proposed algorithm is better than the five conventional algorithms, that is, three-step search (TSS, new three-step search (N3SS, four three-step search (4SS, block-based gradient decent search (BBGDS, and diamond search (DS, in terms of speed or picture quality for eight benchmark sequences.

  8. Novel blue emitters based on {pi}-conjugated block copolymers

    Energy Technology Data Exchange (ETDEWEB)

    Peres, L.O. [Universidade Federal de Sao Paulo - Campus Diadema, Rua Prof. Artur Riedel, 275, Cep 09972-270 - Jd Eldorado - Diadema - SP (Brazil)], E-mail: laura_peres@hotmail.com; Wang, S.H. [Departamento de Engenharia Metalurgica e de Materiais, Escola Politecnica, Universidade de Sao Paulo, Av. Prof. Mello Moraes 2463, 05508-900 Sao Paulo, SP (Brazil)], E-mail: wangshui@usp.br; Wery, J.; Froyer, G. [Institut des Materiaux Jean Rouxel, 2 Rue de la Houssiniere, BP 32229, 44322 Nantes Cedex 03 (France); Faulques, E. [Institut des Materiaux Jean Rouxel, 2 Rue de la Houssiniere, BP 32229, 44322 Nantes Cedex 03 (France)], E-mail: eric.faulques@cnrs-imn.fr

    2009-03-01

    A series of new phenyl-based conjugated copolymers has been synthesized and investigated by vibrational and photoluminescence spectroscopy (PL). The materials are: poly(1,4-phenylene-alt-3,6-pyridazine) (COP-PIR), poly(9,9-dioctylfluorene)-co-quaterphenylene (COP-PPP) and poly[(1,4-phenylene-alt-3,6-pyridazine)-co-(1,4-phenylene-alt-9, 9-dioctylfluorene)] (COP-PIR-FLUOR), with 3.5% of fluorene. COP-PPP and COP-PIR-FLUOR have high fluorescence quantum yields in solution. Infrared and Raman spectra were used to check the chemical structure of the compounds. The copolymers exhibit blue emission ranging from 2.8 to 3.6 eV when excited at E{sub exc} = 4.13 eV. Stokes-shift values were estimated on pristine samples in their condensed state from steady-state PL-emission and PL-excitation spectra. They suggest a difference in the torsional angle between the molecular configuration of the polymer blocks at the absorption and PL transitions and also in the photoexcitation diffusion. Additionally, the time-resolved PL of these materials has been investigated by using 100 fs laser pulses at E{sub exc} = 4.64 eV and a streak camera. Results show very fast biexponential kinetics for the two fluorene-based polymers with decay times below 300 ps indicating both intramolecular, fast radiative recombination and migration of photogenerated electron-hole pairs. By contrast, the PL of COP-PIR is less intense and longer lived, indicating that excitons are confined to the chains in this polymer.

  9. Evolutionary Fuzzy Block-Matching-Based Camera Raw Image Denoising.

    Science.gov (United States)

    Yang, Chin-Chang; Guo, Shu-Mei; Tsai, Jason Sheng-Hong

    2017-09-01

    An evolutionary fuzzy block-matching-based image denoising algorithm is proposed to remove noise from a camera raw image. Recently, a variance stabilization transform is widely used to stabilize the noise variance, so that a Gaussian denoising algorithm can be used to remove the signal-dependent noise in camera sensors. However, in the stabilized domain, the existed denoising algorithm may blur too much detail. To provide a better estimate of the noise-free signal, a new block-matching approach is proposed to find similar blocks by the use of a type-2 fuzzy logic system (FLS). Then, these similar blocks are averaged with the weightings which are determined by the FLS. Finally, an efficient differential evolution is used to further improve the performance of the proposed denoising algorithm. The experimental results show that the proposed denoising algorithm effectively improves the performance of image denoising. Furthermore, the average performance of the proposed method is better than those of two state-of-the-art image denoising algorithms in subjective and objective measures.

  10. Saturation Detection-Based Blocking Scheme for Transformer Differential Protection

    Directory of Open Access Journals (Sweden)

    Byung Eun Lee

    2014-07-01

    Full Text Available This paper describes a current differential relay for transformer protection that operates in conjunction with a core saturation detection-based blocking algorithm. The differential current for the magnetic inrush or over-excitation has a point of inflection at the start and end of each saturation period of the transformer core. At these instants, discontinuities arise in the first-difference function of the differential current. The second- and third-difference functions convert the points of inflection into pulses, the magnitudes of which are large enough to detect core saturation. The blocking signal is activated if the third-difference of the differential current is larger than the threshold and is maintained for one cycle. In addition, a method to discriminate between transformer saturation and current transformer (CT saturation is included. The performance of the proposed blocking scheme was compared with that of a conventional harmonic blocking method. The test results indicate that the proposed scheme successfully discriminates internal faults even with CT saturation from the magnetic inrush, over-excitation, and external faults with CT saturation, and can significantly reduce the operating time delay of the relay.

  11. Sequential and parallel block-structured shortest-path ray-tracing algorithms

    Science.gov (United States)

    Johnson, Olin G.; Yang, Tien-wan

    1993-12-01

    Shortest path network algorithms have been applied to geophysical raytracing by Nakanishi and Yamaguchi and Moser. In the present work two new algorithms are introduced which further exploit the special structure of network models as applied to geological structures. The algorithm differs in the scanning order of network blocks in a processing queue. An early version of this concept, with computed examples was given. Mathematical correctness of both algorithms, `block-greedy' and `block-breadth', is established. It is then shown that block- greedy limits the updating cycles per block but is inherently sequential whereas block-breadth may incur back-tracking but allows parallel execution. Shared memory architectures allow block level parallelization with guided self-scheduling on a global queue. Message-passing architectures allow direct parallel counterparts to sequential breadth-first execution.

  12. Transformation of frequency-magnitude relation prior to large events in the model of block structure dynamics

    Directory of Open Access Journals (Sweden)

    A. Soloviev

    2008-02-01

    Full Text Available The b-value change in the frequency-magnitude (FM distribution for a synthetic earthquake catalogue obtained by means of the model of block structure dynamics has been studied. The catalogue is divided into time periods preceding strong earthquakes and time periods that do not precede strong earthquakes. The separate analysis of these periods shows that the b-value is smaller before strong earthquakes. The similar phenomenon has been found also for the observed seismicity of the Southern California. The model of block structure dynamics represents a seismic region as a system of perfectly rigid blocks divided by infinitely thin plane faults. The blocks interact between themselves and with the underlying medium. The system of blocks moves as a consequence of prescribed motion of the boundary blocks and of the underlying medium. As the blocks are perfectly rigid, all deformation takes place in the fault zones and at the block base in contact with the underlying medium. Relative block displacements take place along the fault zones. Block motion is defined so that the system is in a quasistatic equilibrium state. The interaction of blocks along the fault zones is viscous-elastic ("normal state" while the ratio of the stress to the pressure remains below a certain strength level. When the critical level is exceeded in some part of a fault zone, a stress-drop ("failure" occurs (in accordance with the dry friction model, possibly causing failure in other parts of the fault zones. These failures produce earthquakes. Immediately after the earthquake and for some time after, the affected parts of the fault zones are in a state of creep. This state differs from the normal state because of a faster growth of inelastic displacements, lasting until the stress falls below some other level. This numerical simulation gives rise a synthetic earthquake catalogue.

  13. Efficient block-based frequency domain wavelet transform implementations.

    Science.gov (United States)

    Lin, Jianyu; Smith, Mark J T

    2009-08-01

    Subband decompositions for image coding have been explored extensively over the last few decades. The condensed wavelet packet (CWP) transform is one such decomposition that was recently shown to have coding performance advantages over conventional decompositions. A special feature of the CWP is that its design and implementation are performed in the cyclic frequency domain. While performance gains have been reported, efficient implementations of the CWP (or more generally, efficient implementations of cyclic filter banks) have not yet been fully explored. In this paper, we present efficient block-based implementations of cyclic filter banks along with an analysis of the arithmetic complexity. Block-based cyclic filter bank implementations of the CWP coder are compared with conventional subband/wavelet image coders whose filter banks are implemented in the time domain. It is shown that block-based cyclic filter bank implementations can result in CWP coding systems that outperform the popular image coding systems both in terms of arithmetic complexity and coding performance.

  14. Tensor Block-Sparsity Based Representation for Spectral-Spatial Hyperspectral Image Classification

    Directory of Open Access Journals (Sweden)

    Zhi He

    2016-08-01

    Full Text Available Recently, sparse representation has yielded successful results in hyperspectral image (HSI classification. In the sparse representation-based classifiers (SRCs, a more discriminative representation that preserves the spectral-spatial information can be exploited by treating the HSI as a whole entity. Based on this observation, a tensor block-sparsity based representation method is proposed for spectral-spatial classification of HSI in this paper. Unlike traditional vector/matrix-based SRCs, the proposed method consists of tensor block-sparsity based dictionary learning and class-dependent block sparse representation. By naturally regarding the HSI cube as a third-order tensor, small local patches centered at the training samples are extracted from the HSI to maintain the structural information. All the patches are then partitioned into a number of groups, on which a dictionary learning model is constructed with a tensor block-sparsity constraint. A test sample is also expressed as a small local patch and the block sparse representation is then performed in a class-wise manner to take advantage of the class label information. Finally, the category of the test sample is determined by using the minimal residual. Experimental results of two real-world HSIs show that our proposed method greatly improves the classification performance of SRC.

  15. A polyoxometalate-based inorganic-organic hybrid polymer constructed from silver-Schiff base building block and Keggin-type cluster: Synthesis, crystal structure and photocatalytic performance for the degradation of rhodamine B.

    Science.gov (United States)

    Li, Lei; Cheng, Meng; Bai, Yan; An, Bing; Dang, Dongbin

    2015-11-05

    One polyoxometalate-based inorganic-organic hybrid polymer [Ag3L4(PMo12O40)(CH3OH)]·CH3OH (1), where L is N,N'-bis(furan-2-ylmethylene)hydrazine, has been synthesized at room temperature and structurally characterized by infrared spectroscopy, ultraviolet-visible spectroscopy, elemental analysis, X-ray powder diffraction and X-ray single-crystal crystallography. The structure of 1 exhibits a crystalline one-dimensional polymer constructed by the connections of Keggin-type [PMo12O40](3-) anions and [Ag3L4](3+) units, in which each Ag(I) center adopted a distorted square pyramidal environment. The spectroscopic experiments show that polymer 1 not only is potential semiconductor materials but also displays the obvious photocatalytic performance for the degradation of rhodamine B. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Distinguish Dynamic Basic Blocks by Structural Statistical Testing

    DEFF Research Database (Denmark)

    Petit, Matthieu; Gotlieb, Arnaud

    selection of test data over the subdomain associated with these paths. Baudry et al. present a testing for-diagnosis method where the essential notion of Dynamic Basic Block was identified to be strongly correlated to the effectiveness of fault-localization technique. We show that generating a sequence...

  17. Intramolecular structures in a single copolymer chain consisting of flexible and semiflexible blocks: Monte Carlo simulation of a lattice model

    International Nuclear Information System (INIS)

    Martemyanova, Julia A; Ivanov, Victor A; Paul, Wolfgang

    2014-01-01

    We study conformational properties of a single multiblock copolymer chain consisting of flexible and semiflexible blocks. Monomer units of different blocks are equivalent in the sense of the volume interaction potential, but the intramolecular bending potential between successive bonds along the chain is different. We consider a single flexible-semiflexible regular multiblock copolymer chain with equal content of flexible and semiflexible units and vary the length of the blocks and the stiffness parameter. We perform flat histogram type Monte Carlo simulations based on the Wang-Landau approach and employ the bond fluctuation lattice model. We present here our data on different non-trivial globular morphologies which we have obtained in our model for different values of the block length and the stiffness parameter. We demonstrate that the collapse can occur in one or in two stages depending on the values of both these parameters and discuss the role of the inhomogeneity of intraglobular distributions of monomer units of both flexible and semiflexible blocks. For short block length and/or large stiffness the collapse occurs in two stages, because it goes through intermediate (meta-)stable structures, like a dumbbell shaped conformation. In such conformations the semiflexible blocks form a cylinder-like core, and the flexible blocks form two domains at both ends of such a cylinder. For long block length and/or small stiffness the collapse occurs in one stage, and in typical conformations the flexible blocks form a spherical core of a globule while the semiflexible blocks are located on the surface and wrap around this core.

  18. Quantifying motion in video recordings of neonatal seizures by feature trackers based on predictive block matching.

    Science.gov (United States)

    Karayiannis, N B; Sami, A; Frost, J D; Wise, M S; Mizrahi, E M

    2004-01-01

    This work introduces predictive block matching, a method developed to track motion in video by exploiting the advantages of block motion estimation and adaptive block matching. The proposed method relies on a pure translation motion model to estimate the displacement of a block between two successive video frames before initiating the search for the best match of the block tracked throughout the frame sequence. The search for the best match relies on adaptive block matching, which employs an update strategy based on Kalman filtering to account for the changing appearance of the block. Predictive block matching was used to extract motor activity signals from video recordings of neonatal seizures.

  19. Morphology-properties relationship on nanocomposite films based on poly(styrene-block-diene-block-styrene copolymers and silver nanoparticles

    Directory of Open Access Journals (Sweden)

    2011-02-01

    Full Text Available A comparative study on the self-assembled nanostructured morphology and the rheological and mechanical properties of four different triblock copolymers, based on poly(styrene-block-diene-block-styrene and poly(styrene-block-diene-block-styrene matrices, and of their respective nanocomposites with 1 wt% silver nanoparticles, is reported in this work. In order to obtain well-dispersed nanoparticles in the block copolymer matrix, dodecanethiol was used as surfactant, showing good affinity with both nanoparticles and the polystyrene phase of the matrices as predicted by the solubility parameters calculated based on Hoftyzer and Van Krevelen theory. The block copolymer with the highest PS content shows the highest tensile modulus and tensile strength, but also the smallest elongation at break. When silver nanoparticles treated with surfactant were added to the block copolymer matrices, each system studied shows higher mechanical properties due to the good dispersion and the good interface of Ag nanoparticles in the matrices. Furthermore, it has been shown that semiempirical models such as Guth and Gold equation and Halpin-Tsai model can be used to predict the tensile modulus of the analyzed nanocomposites.

  20. Haplotype block structure and its applications to association studies: power and study designs.

    Science.gov (United States)

    Zhang, Kui; Calabrese, Peter; Nordborg, Magnus; Sun, Fengzhu

    2002-12-01

    Recent studies have shown that the human genome has a haplotype block structure, such that it can be divided into discrete blocks of limited haplotype diversity. In each block, a small fraction of single-nucleotide polymorphisms (SNPs), referred to as "tag SNPs," can be used to distinguish a large fraction of the haplotypes. These tag SNPs can potentially be extremely useful for association studies, in that it may not be necessary to genotype all SNPs; however, this depends on how much power is lost. Here we develop a simulation study to quantitatively assess the power loss for a variety of study designs, including case-control designs and case-parental control designs. First, a number of data sets containing case-parental or case-control samples are generated on the basis of a disease model. Second, a small fraction of case and control individuals in each data set are genotyped at all the loci, and a dynamic programming algorithm is used to determine the haplotype blocks and the tag SNPs based on the genotypes of the sampled individuals. Third, the statistical power of tests was evaluated on the basis of three kinds of data: (1) all of the SNPs and the corresponding haplotypes, (2) the tag SNPs and the corresponding haplotypes, and (3) the same number of randomly chosen SNPs as the number of tag SNPs and the corresponding haplotypes. We study the power of different association tests with a variety of disease models and block-partitioning criteria. Our study indicates that the genotyping efforts can be significantly reduced by the tag SNPs, without much loss of power. Depending on the specific haplotype block-partitioning algorithm and the disease model, when the identified tag SNPs are only 25% of all the SNPs, the power is reduced by only 4%, on average, compared with a power loss of approximately 12% when the same number of randomly chosen SNPs is used in a two-locus haplotype analysis. When the identified tag SNPs are approximately 14% of all the SNPs, the

  1. An electrostatic Particle-In-Cell code on multi-block structured meshes

    Science.gov (United States)

    Meierbachtol, Collin S.; Svyatskiy, Daniil; Delzanno, Gian Luca; Vernon, Louis J.; Moulton, J. David

    2017-12-01

    We present an electrostatic Particle-In-Cell (PIC) code on multi-block, locally structured, curvilinear meshes called Curvilinear PIC (CPIC). Multi-block meshes are essential to capture complex geometries accurately and with good mesh quality, something that would not be possible with single-block structured meshes that are often used in PIC and for which CPIC was initially developed. Despite the structured nature of the individual blocks, multi-block meshes resemble unstructured meshes in a global sense and introduce several new challenges, such as the presence of discontinuities in the mesh properties and coordinate orientation changes across adjacent blocks, and polyjunction points where an arbitrary number of blocks meet. In CPIC, these challenges have been met by an approach that features: (1) a curvilinear formulation of the PIC method: each mesh block is mapped from the physical space, where the mesh is curvilinear and arbitrarily distorted, to the logical space, where the mesh is uniform and Cartesian on the unit cube; (2) a mimetic discretization of Poisson's equation suitable for multi-block meshes; and (3) a hybrid (logical-space position/physical-space velocity), asynchronous particle mover that mitigates the performance degradation created by the necessity to track particles as they move across blocks. The numerical accuracy of CPIC was verified using two standard plasma-material interaction tests, which demonstrate good agreement with the corresponding analytic solutions. Compared to PIC codes on unstructured meshes, which have also been used for their flexibility in handling complex geometries but whose performance suffers from issues associated with data locality and indirect data access patterns, PIC codes on multi-block structured meshes may offer the best compromise for capturing complex geometries while also maintaining solution accuracy and computational efficiency.

  2. Electrically and chemically tunable soft-solid block copolymer structural color (Conference Presentation)

    Science.gov (United States)

    Park, Cheolmin

    2016-09-01

    1D photonic crystals based on the periodic stacking of two different dielectric layers have been widely studied due to their potential use in low-power reflective mode displays, e-books and sensors, but the fabrication of mechanically flexible polymer structural color (SC) films, with electro-active color switching, remains challenging. Here, we demonstrate free-standing electric field tunable ionic liquid swollen block copolymer films. Placement of a polymer/ionic liquid (IL) film-reservoir adjacent to a self-assembled poly(styrene-block-quaternized 2vinyl pyridine) (PS-b-QP2VP) copolymer SC film allowed the development of R, G and B full-color SC block copolymer films by swelling of the QP2VP domains by the ionic liquid associated with water molecules. The IL-polymer/BCP SC film is mechanically flexible with excellent color stability over several days at ambient conditions. The selective swelling of the QP2VP domains could be controlled by both the ratio of the IL to a polymer in the gel-like IL reservoir layer and by an applied voltage in the range of -3V to +6V using a metal/IL reservoir/SC film/IL reservoir/metal capacitor type device.

  3. Quantification of urban structure on building block level utilizing multisensoral remote sensing data

    Science.gov (United States)

    Wurm, Michael; Taubenböck, Hannes; Dech, Stefan

    2010-10-01

    Dynamics of urban environments are a challenge to a sustainable development. Urban areas promise wealth, realization of individual dreams and power. Hence, many cities are characterized by a population growth as well as physical development. Traditional, visual mapping and updating of urban structure information of cities is a very laborious and cost-intensive task, especially for large urban areas. For this purpose, we developed a workflow for the extraction of the relevant information by means of object-based image classification. In this manner, multisensoral remote sensing data has been analyzed in terms of very high resolution optical satellite imagery together with height information by a digital surface model to retrieve a detailed 3D city model with the relevant land-use / land-cover information. This information has been aggregated on the level of the building block to describe the urban structure by physical indicators. A comparison between the indicators derived by the classification and a reference classification has been accomplished to show the correlation between the individual indicators and a reference classification of urban structure types. The indicators have been used to apply a cluster analysis to group the individual blocks into similar clusters.

  4. Sprayable elastic conductors based on block copolymer silver nanoparticle composites.

    Science.gov (United States)

    Vural, Mert; Behrens, Adam M; Ayyub, Omar B; Ayoub, Joseph J; Kofinas, Peter

    2015-01-27

    Block copolymer silver nanoparticle composite elastic conductors were fabricated through solution blow spinning and subsequent nanoparticle nucleation. The reported technique allows for conformal deposition onto nonplanar substrates. We additionally demonstrated the ability to tune the strain dependence of the electrical properties by adjusting nanoparticle precursor concentration or localized nanoparticle nucleation. The stretchable fiber mats were able to display electrical conductivity values as high as 2000 ± 200 S/cm with only a 12% increase in resistance after 400 cycles of 150% strain. Stretchable elastic conductors with similar and higher bulk conductivity have not achieved comparable stability of electrical properties. These unique electromechanical characteristics are primarily the result of structural changes during mechanical deformation. The versatility of this approach was demonstrated by constructing a stretchable light emitting diode circuit and a strain sensor on planar and nonplanar substrates.

  5. Well-solvable cases of the QAP with block-structured matrices

    OpenAIRE

    Çela, E; Deineko, VG; Woeginger, GJ Gerhard

    2014-01-01

    We investigate special cases of the quadratic assignment problem (QAP) where one of the two underlying matrices carries a simple block structure. For the special case where the second underlying matrix is a monotone anti-Monge matrix, we derive a polynomial time result for a certain class of cut problems. For the special case where the second underlying matrix is a product matrix, we identify two sets of conditions on the block structure that make this QAP polynomially solvable respectively N...

  6. Controlling Random Waves with Digital Building Blocks Based on Supersymmetry

    Science.gov (United States)

    Yu, Sunkyu; Piao, Xianji; Park, Namkyoo

    2017-11-01

    Harnessing multimode waves allows high information capacity through modal expansions. Although passive multimode devices for broadband responses have been demonstrated in momentum or frequency domains, the difficulty in achieving collective manipulation of all eigenmodes has hindered the implementation of digital multimode devices such as switching. Here we propose building blocks for digital switching of spatially random waves based on parity-converted supersymmetric pairs of multimode potentials. We reveal that unbroken supersymmetric transformations of any parity-symmetric potential derive the parity reversal of all eigenmodes, which allows the complete isolation of random waves in the "off" state. With two representative solvable potentials, building blocks for binary and many-valued logics are then demonstrated for random waves: a harmonic pair for binary switching of arbitrary wave fronts and a Pöschl-Teller pair for multilevel switching which implements fuzzy membership functions. Our results realizing the transfer of arbitrary wave fronts between wave elements will lay the foundation of high-bandwidth data processing.

  7. Reliability study of Piezoelectric Structures Dedicated to Energy Harvesting by the Way of Blocking Force Investigation

    International Nuclear Information System (INIS)

    Maaroufi, S; Parrain, F; Lefeuvre, E; Boutaud, B; Molin, R Dal

    2015-01-01

    In this paper we propose an approach to study the reliability of piezoelectric structures and more precisely energy harvesting micro-devices dedicated to autonomous active medical implants (new generation pacemakers). The structure under test is designed as a bimorph piezoelectric cantilever with a seismic mass at its tip. Good understanding of material aging and mechanical failure is critical for this kind of system. To study the reliability and durability of the piezoelectric part we propose to establish a new accelerated methodology and an associated test bench where the environment and stimuli can be precisely controlled over a wide period of time. This will allow the identification of potential failure modes and the study of their impacts by the way of direct mechanical investigation based on stiffness and blocking force measurements performed periodically. (paper)

  8. Solar Energy Block-Based Residential Construction for Rural Areas in the West of China

    Directory of Open Access Journals (Sweden)

    Jizhong Shao

    2016-04-01

    Full Text Available Based on the Great Western Development Strategy and the requirement for sustainable development in the west of China, rural affordable housing, energy conservation, and environmental protection are becoming development standards in the construction field. This paper mainly explores an innovative, sustainable, residential construction method for rural areas in western China, particularly the integration of solar energy technology with modern prefabricated building techniques, formally named solar energy block-based construction. The conscious approach of using volumetric blocks provides superior adaptability and expansibility in integration with a steel structure, thereby reducing the construction time and cost. Allowing a wide variety of configurations and styles in the building layout, this approach can be customized to the end-user’s precise location and climate, making rural residential buildings much more flexible and modern. To take advantage of adequate solar energy resource in western China, the blocks are associated with active and passive solar energy technologies, thereby reducing pollution, mitigating global warming, and enhancing sustainability. Therefore, we concluded that solar energy block-based construction could bring significant benefits to the environment, economy, and society. It could also promote sustainable development in the rural regions of western China.

  9. Metallopolymer-Based Block Copolymers for the Preparation of Porous and Redox-Responsive Materials.

    Science.gov (United States)

    Rüttiger, Christian; Hübner, Hanna; Schöttner, Sebastian; Winter, Tamara; Cherkashinin, Gennady; Kuttich, Björn; Stühn, Bernd; Gallei, Markus

    2018-01-31

    Metallopolymers are a unique class of functional materials because of their redox-mediated optoelectronic and catalytic switching capabilities and, as recently shown, their outstanding structure formation and separation capabilities. Within the present study, (tri)block copolymers of poly(isoprene) (PI) and poly(ferrocenylmethyl methacrylate) having different block compositions and overall molar masses up to 328 kg mol -1 are synthesized by anionic polymerization. The composition and thermal properties of the metallopolymers are investigated by state-of-the-art polymer analytical methods comprising size exclusion chromatography, 1 H NMR spectroscopy, differential scanning calorimetry, and thermogravimetric analysis. As a focus of this work, excellent microphase separation of the synthesized (tri)block copolymers is proven by transmission electron microscopy, scanning electron microcopy, energy-dispersive X-ray spectroscopy, small-angle X-ray scattering measurements showing spherical, cylindrical, and lamellae morphologies. As a highlight, the PI domains are subjected to ozonolysis for selective domain removal while maintaining the block copolymer morphology. In addition, the novel metalloblock copolymers can undergo microphase separation on cellulose-based substrates, again preserving the domain order after ozonolysis. The resulting nanoporous structures reveal an intriguing switching capability after oxidation, which is of interest for controlling the size and polarity of the nanoporous architecture.

  10. ASIC chipset design to generate block-based complex holographic video.

    Science.gov (United States)

    Seo, Young-Ho; Lee, Yoon-Hyuk; Kim, Dong-Wook

    2017-03-20

    In this paper, we propose a new hardware architecture implemented as a very large scaled integrated circuit by using an application-specific integrated circuit technology, where block-based calculations are used to generate holograms. The proposed hardware is structured to produce a part of a hologram in the block units in parallel. A block of a hologram is calculated using an object point, and then the calculation is repeated for all object points to obtain intermediate results that are accumulated to produce the final block of a hologram. This structure can be used to produce holograms of various sizes in real time with optimized memory access. The proposed hardware was implemented using the Hynix 0.18 μm CMOS technology of Magna Chip, Inc., and it has about 448 K gate counts and a silicon size of 3.592  mm×3.592  mm. It can generate complex holograms and operate in a stable manner at a clock frequency of 200 MHz.

  11. An object-oriented approach for parallel self adaptive mesh refinement on block structured grids

    Science.gov (United States)

    Lemke, Max; Witsch, Kristian; Quinlan, Daniel

    1993-01-01

    Self-adaptive mesh refinement dynamically matches the computational demands of a solver for partial differential equations to the activity in the application's domain. In this paper we present two C++ class libraries, P++ and AMR++, which significantly simplify the development of sophisticated adaptive mesh refinement codes on (massively) parallel distributed memory architectures. The development is based on our previous research in this area. The C++ class libraries provide abstractions to separate the issues of developing parallel adaptive mesh refinement applications into those of parallelism, abstracted by P++, and adaptive mesh refinement, abstracted by AMR++. P++ is a parallel array class library to permit efficient development of architecture independent codes for structured grid applications, and AMR++ provides support for self-adaptive mesh refinement on block-structured grids of rectangular non-overlapping blocks. Using these libraries, the application programmers' work is greatly simplified to primarily specifying the serial single grid application and obtaining the parallel and self-adaptive mesh refinement code with minimal effort. Initial results for simple singular perturbation problems solved by self-adaptive multilevel techniques (FAC, AFAC), being implemented on the basis of prototypes of the P++/AMR++ environment, are presented. Singular perturbation problems frequently arise in large applications, e.g. in the area of computational fluid dynamics. They usually have solutions with layers which require adaptive mesh refinement and fast basic solvers in order to be resolved efficiently.

  12. Entropy-Based Block Processing for Satellite Image Registration

    Directory of Open Access Journals (Sweden)

    Ikhyun Lee

    2012-11-01

    Full Text Available Image registration is an important task in many computer vision applications such as fusion systems, 3D shape recovery and earth observation. Particularly, registering satellite images is challenging and time-consuming due to limited resources and large image size. In such scenario, state-of-the-art image registration methods such as scale-invariant feature transform (SIFT may not be suitable due to high processing time. In this paper, we propose an algorithm based on block processing via entropy to register satellite images. The performance of the proposed method is evaluated using different real images. The comparative analysis shows that it not only reduces the processing time but also enhances the accuracy.

  13. Structure-property relations of segmented block copolymers with liquid liquid demixed morphologies

    NARCIS (Netherlands)

    van der Schuur, J.M.; van der Heide, Evert; Feijen, Jan; Gaymans, R.J.

    2005-01-01

    Poly(propylene oxide) based polyether(ester-amide)s (PEEA) with non-crystallisable amide segments were synthesized and their structure–property relations studied. These model segmented block copolymers were used to gain insight in the structure–property relations of block copolymers with

  14. Trellises and Trellis-Based Decoding Algorithms for Linear Block Codes

    Science.gov (United States)

    Lin, Shu

    1998-01-01

    A code trellis is a graphical representation of a code, block or convolutional, in which every path represents a codeword (or a code sequence for a convolutional code). This representation makes it possible to implement Maximum Likelihood Decoding (MLD) of a code with reduced decoding complexity. The most well known trellis-based MLD algorithm is the Viterbi algorithm. The trellis representation was first introduced and used for convolutional codes [23]. This representation, together with the Viterbi decoding algorithm, has resulted in a wide range of applications of convolutional codes for error control in digital communications over the last two decades. There are two major reasons for this inactive period of research in this area. First, most coding theorists at that time believed that block codes did not have simple trellis structure like convolutional codes and maximum likelihood decoding of linear block codes using the Viterbi algorithm was practically impossible, except for very short block codes. Second, since almost all of the linear block codes are constructed algebraically or based on finite geometries, it was the belief of many coding theorists that algebraic decoding was the only way to decode these codes. These two reasons seriously hindered the development of efficient soft-decision decoding methods for linear block codes and their applications to error control in digital communications. This led to a general belief that block codes are inferior to convolutional codes and hence, that they were not useful. Chapter 2 gives a brief review of linear block codes. The goal is to provide the essential background material for the development of trellis structure and trellis-based decoding algorithms for linear block codes in the later chapters. Chapters 3 through 6 present the fundamental concepts, finite-state machine model, state space formulation, basic structural properties, state labeling, construction procedures, complexity, minimality, and

  15. Rheological characterization of nanostructured material based on Polystyrene-b-poly(ethylene-butylene)-b-polystyrene (SEBS) block copolymer: Effect of block copolymer composition and nanoparticle geometry

    OpenAIRE

    Hasanabadi, Noushin; Nazockdast, Hossein; Balog, Sandor; Lattuada, Marco

    2017-01-01

    Block copolymer (BCP) nanocomposite systems are of broad interest; however, reports on the role of nanoparticles on microphase separation behavior are rare. The goal of present study is to investigate the preparation of composite nanostructured materials containing Multi-Walled Carbon Nanotubes (MWCNTs) or graphene nanoplates. BCP nanocomposites based on the linear triblock copolymer, Polystyrene-b-poly(ethylene-butylene)-b-polystyrene (SEBS), with different morphological structure were...

  16. An Arithmetic Coding Scheme for Blocked-based Compressive Sensing of Images

    OpenAIRE

    Gao, Min

    2016-01-01

    Differential pulse-code modulation (DPCM) is recently coupled with uniform scalar quantization (SQ) to improve the rate-distortion (RD) performance for the block-based quantized compressive sensing (CS) of images. In this framework, for each block's CS measurements, a prediction is generated based on the reconstructed CS measurements of the previous blocks and subtracted from measurements of the current block in the measurement domain. The resulting residual is then quantized by uniform SQ to...

  17. Block-structured Adaptive Mesh Refinement - Theory, Implementation and Application

    Directory of Open Access Journals (Sweden)

    Deiterding Ralf

    2011-12-01

    Full Text Available Structured adaptive mesh refinement (SAMR techniques can enable cutting-edge simulations of problems governed by conservation laws. Focusing on the strictly hyperbolic case, these notes explain all algorithmic and mathematical details of a technically relevant implementation tailored for distributed memory computers. An overview of the background of commonly used finite volume discretizations for gas dynamics is included and typical benchmarks to quantify accuracy and performance of the dynamically adaptive code are discussed. Large-scale simulations of shock-induced realistic combustion in non-Cartesian geometry and shock-driven fluid-structure interaction with fully coupled dynamic boundary motion demonstrate the applicability of the discussed techniques for complex scenarios.

  18. Studies on microphase-separated structures of block copolymers by neutron reflectivity measurement

    International Nuclear Information System (INIS)

    Torikai, Naoya; Noda, Ichiro; Matsushita, Yushu; Karim, A.; Satija, S.K.; Han, C.C.; Ebisawa, Toru.

    1996-01-01

    Segmental distributions of block copolymer chains in lamellar microphase-separated structure and those of homopolymers in block copolymer/homopolymer blends also with lamellar structures were studied by neutron reflectivity measurements. It was revealed that polystyrene and poly(2-vinylpyridine) lamellae were alternately stacked within the thin films of pure block copolymers spin-coated on silicon wafers, and they were preferentially oriented along the direction parallel to film surface. Polystyrene lamella appeared at air surfaces of the films, while poly(2-vinylpyridine) lamella did on silicon surfaces. Segment distribution at lamellar interface was well described by an error function, and the width of the lamellar interface, defined by a full-width half-maximum value of interfacial profile, was estimated to be about 4.5 nm. Segments of block chains adjacent to the chemical junction points connecting different block chains were strongly localized near the lamellar interfaces, while those on the free ends of block chains were distributed all over the lamellar microdomains with their distribution maxima at the centers of lamellae. On the other hand, it was clarified that homopolymers dissolved in the corresponding lamellar microdomains of block copolymers were also distributed throughout the microdomains with their concentration maxima at the centers of the lamellae. (author)

  19. The Organization of Nanoporous Structure Using Controlled Micelle Size from MPEG-b-PDLLA Block Copolymers

    International Nuclear Information System (INIS)

    Chang, Jeong Ho; Kim, Kyung Ja; Shin, Young Kook

    2004-01-01

    Selected MPEG-b-PDLLA block copolymers have been synthesized by ring-opening polymerization with systematic variation of the chain lengths of the resident hydrophilic and hydrophobic blocks. The size and shape of the micelles that spontaneously form in solution are then controlled by the characteristics of the block copolymer template. All the materials prepared in this study showed the tunable pore size of 20-80 A with the increase of hydrophobic chain lengths and up to 660 m 2 /g of specific surface area. The formation mechanism of these nanoporous structures obtained by controlling the micelle size has been confirmed using both liquid and solid state 13 C and 29 Si NMR techniques. This work verifies the formation mechanism of nanoporous structures in which the pore size and wall thickness are closely dependent on the size of hydrophobic cores and hydrophilic shells of the block copolymer templates

  20. Plastic deformation modelling of tempered martensite steel block structure by a nonlocal crystal plasticity model

    Directory of Open Access Journals (Sweden)

    Martin Boeff

    2014-01-01

    Full Text Available The plastic deformations of tempered martensite steel representative volume elements with different martensite block structures have been investigated by using a nonlocal crystal plasticity model which considers isotropic and kinematic hardening produced by plastic strain gradients. It was found that pronounced strain gradients occur in the grain boundary region even under homogeneous loading. The isotropic hardening of strain gradients strongly influences the global stress–strain diagram while the kinematic hardening of strain gradients influences the local deformation behaviour. It is found that the additional strain gradient hardening is not only dependent on the block width but also on the misorientations or the deformation incompatibilities in adjacent blocks.

  1. The Structure of the Onega Downthrown Block and Adjacent Geological Objects According to the Microseismic Sounding Method

    Science.gov (United States)

    Danilov, Konstantin B.

    2017-07-01

    The geological structure of the major part of the Arkhangelsk region in the North-West Russia has been poorly studied. In the present work, the microseismic sounding method was, for the first time, used to carry out a detailed geological-geophysical survey in the region. The particles motion study confirmed the results of mathematical modeling of the smallest imaged heterogeneity and resolution of the method. The microseism stability study allowed to determine the amount of error of the microseismic sounding method which is 1-2 dB. Two geophysical cross sections of the north-eastern and south-western boundaries of the Onega downthrown block were studied. The method was shown to allow obtaining seismic images with a high precision in the horizontal direction at relatively low costs in terms of time and finances. The obtained data provided additional information about the structure of the crust, which was consistent with the known geological and geophysical information for the surveyed area. Based on the data, it was concluded that the main reasons of the dissonance of geological information were most likely the division of the downthrown block into the northern and southern blocks and horizontal displacement of the layer to the North at a depth ranging from 3 to 5 km. It was suggested that the most active tectonic processes, including eruptions of ancient volcanoes, occurred in the northern block. Two benches at the studied downthrown block were allocated at the depths of 5 and 10 km.

  2. Contributions to Estimation and Testing Block Covariance Structures in Multivariate Normal Models

    OpenAIRE

    Liang, Yuli

    2015-01-01

    This thesis concerns inference problems in balanced random effects models with a so-called block circular Toeplitz covariance structure. This class of covariance structures describes the dependency of some specific multivariate two-level data when both compound symmetry and circular symmetry appear simultaneously. We derive two covariance structures under two different invariance restrictions. The obtained covariance structures reflect both circularity and exchangeability present in the data....

  3. Association and Structure of Thermo Sensitive Comblike Block Copolymers in Aqueous Solutions

    International Nuclear Information System (INIS)

    Cheng, Gang

    2008-01-01

    The structures and association properties of thermo sensitive poly(methoxyoligo(ethylene glycol) norbornenyl esters) block copolymers in D2O were investigated by Small Angle Neutron Scattering (SANS). Each block is a comb-like polymer with a polynorbornene (PNB) backbone and oligo ethylene glycol (OEG) side chains (one side chain per NB monomer). The chemical formula of the block copolymer is (OEG3NB)79-(OEG6.6NB)67, where subscripts represent the degree of polymerization (DP) of OEG and NB in each block The polymer concentration was fixed at 2.0 wt % and the structural changes were investigated over a temperature range between 25 C and 68 C. It was found that at room temperature polymers associate to form micelles with a spherical core formed by the block (OEG3NB)79 and corona formed by the block (OEG6.6NB)67 and that the shape of the polymer in the corona could be described by the form factor of rigid cylinders. At elevated temperatures, the aggregation number increases and the micelles become more compact. At temperatures round the cloud point temperature (CPT) T = 60 C a correlation peak started to appear and became pronounced at 68 C due to the formation of a partially ordered structure with a correlation length ∼ 349

  4. Asymmetric block copolymer membranes with ultrahigh porosity and hierarchical pore structure by plain solvent evaporation

    KAUST Repository

    Yu, H.

    2016-09-14

    Membranes with a hierarchical porous structure could be manufactured from a block copolymer blend by pure solvent evaporation. Uniform pores in a 30 nm thin skin layer supported by a macroporous structure were formed. This new process is attractive for membrane production because of its simplicity and the lack of liquid waste.

  5. Quasi-Block Copolymers Based on a General Polymeric Chain Stopper.

    Science.gov (United States)

    Sanguramath, Rajashekharayya A; Nealey, Paul F; Shenhar, Roy

    2016-07-11

    Quasi-block copolymers (q-BCPs) are block copolymers consisting of conventional and supramolecular blocks, in which the conventional block is end-terminated by a functionality that interacts with the supramolecular monomer (a "chain stopper" functionality). A new design of q-BCPs based on a general polymeric chain stopper, which consists of polystyrene end-terminated with a sulfonate group (PS-SO3 Li), is described. Through viscosity measurements and a detailed diffusion-ordered NMR spectroscopy study, it is shown that PS-SO3 Li can effectively cap two types of model supramolecular monomers to form q-BCPs in solution. Furthermore, differential scanning calorimetry data and structural characterization of thin films by scanning force microscopy suggests the existence of the q-BCP architecture in the melt. The new design considerably simplifies the synthesis of polymeric chain stoppers; thus promoting the utilization of q-BCPs as smart, nanostructured materials. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Parametric Optimization Design of Brake Block Based on Reverse Engineering

    Directory of Open Access Journals (Sweden)

    Jin Hua-wei

    2017-01-01

    Full Text Available As one of the key part of automotive brake,the performance of brake block has a direct impact on the safety and comfort of cars. Modeling the brake block of disc brake in reverse parameterization by reverse engineering software, analyzing and optimizing the reconstructed model by CAE software. Processing the scanned point cloud by Geomagic Studio and reconstructing the CAD model of the brake block with the parametric surface function of the software, then analyzing and optimizing it by Wrokbench. The example shows that it is quick to reconstruct the CAD model of parts by using reverse parameterization method and reduce part re-design development cycle significantly.

  7. A block structure Laplacian for hyperspectral image data clustering

    CSIR Research Space (South Africa)

    Lunga, D

    2013-12-01

    Full Text Available -kernel based Laplacian matrix Fig. 3. Botswana data Laplacian matrices. Pure blue color indicates small affinity values while red-yellow colors indicates neighborhoods with high weights in the graph. Fig. 1. Colored ground reference of AVIRIS hyperspectral... image over Kennedy Space Center (KSC), Florida. 500 1000 1500 2000 2500 3000 3500 4000 4500 5000 500 1000 1500 2000 2500 3000 3500 4000 4500 5000 Fig. 2. A spatially weighted Laplacian matrix for KSC data. Pure blue color indicates small affinity...

  8. Structure and ionic conductivity of block copolymer electrolytes over a wide salt concentration range

    Science.gov (United States)

    Chintapalli, Mahati; Le, Thao; Venkatesan, Naveen; Thelen, Jacob; Rojas, Adriana; Balsara, Nitash

    Block copolymer electrolytes are promising materials for safe, long-lasting lithium batteries because of their favorable mechanical and ion transport properties. The morphology, phase behavior, and ionic conductivity of a block copolymer electrolyte, SEO mixed with LiTFSI was studied over a wide, previously unexplored salt concentration range using small angle X-ray scattering, differential scanning calorimetry and ac impedance spectroscopy, respectively. SEO exhibits a maximum in ionic conductivity at twice the salt concentration that PEO, the homopolymer analog of the ion-containing block, does. This finding is contrary to prior studies that examined a more limited range of salt concentrations. In SEO, the phase behavior of the PEO block and LiTFSI closely resembles the phase behavior of homopolymer PEO and LiTFSI. The grain size of the block copolymer morphology was found to decrease with increasing salt concentration, and the ionic conductivity of SEO correlates with decreasing grain size. Structural effects impact the ionic conductivity-salt concentration relationship in block copolymer electrolytes. SEO: polystyrene-block-poly(ethylene oxide); also PS-PEO LiTFSI: lithium bis(trifluoromethanesulfonyl imide

  9. Transform extension for block-based hybrid video codec with decoupling transform sizes from prediction sizes and coding sizes

    Science.gov (United States)

    Chen, Jing; Li, Ge; Fan, Kui; Guo, Xiaoqiang

    2017-09-01

    In the block-based hybrid video coding framework, transform is applied to the residual signal resulting from intra/inter prediction. Thus in the most of video codecs, transform block (TB) size is equal to the prediction block (PB) size. To further improve coding efficiency, recent video coding techniques have supported decoupling transform and prediction sizes. By splitting one prediction block into small transform blocks, the Residual Quad-tree (RQT) structure attempts to search the best transform size. However, in the current RQT, the transform size cannot be larger than the size of prediction block. In this paper, we introduce a transform extension method by decoupling transform sizes from prediction sizes and coding sizes. In addition to getting the transform block within the current PB partition, we combine multiple adjacent PBs to form a larger TB and select best block size accordingly. According to our experiment on top of the newest reference software (ITM17.0) of MPEG Internet Video Coding (IVC) standard, consistent coding performance gains are obtained.

  10. [Construction of haplotype and haplotype block based on tag single nucleotide polymorphisms and their applications in association studies].

    Science.gov (United States)

    Gu, Ming-liang; Chu, Jia-you

    2007-12-01

    Human genome has structures of haplotype and haplotype block which provide valuable information on human evolutionary history and may lead to the development of more efficient strategies to identify genetic variants that increase susceptibility to complex diseases. Haplotype block can be divided into discrete blocks of limited haplotype diversity. In each block, a small fraction of ptag SNPsq can be used to distinguish a large fraction of the haplotypes. These tag SNPs can be potentially useful for construction of haplotype and haplotype block, and association studies in complex diseases. There are two general classes of methods to construct haplotype and haplotype blocks based on genotypes on large pedigrees and statistical algorithms respectively. The author evaluate several construction methods to assess the power of different association tests with a variety of disease models and block-partitioning criteria. The advantages, limitations and applications of each method and the application in the association studies are discussed equitably. With the completion of the HapMap and development of statistical algorithms for addressing haplotype reconstruction, ideas of construction of haplotype based on combination of mathematics, physics, and computer science etc will have profound impacts on population genetics, location and cloning for susceptible genes in complex diseases, and related domain with life science etc.

  11. Using block pulse functions for seismic vibration semi-active control of structures with MR dampers

    Science.gov (United States)

    Rahimi Gendeshmin, Saeed; Davarnia, Daniel

    2018-03-01

    This article applied the idea of block pulse functions in the semi-active control of structures. The BP functions give effective tools to approximate complex problems. The applied control algorithm has a major effect on the performance of the controlled system and the requirements of the control devices. In control problems, it is important to devise an accurate analytical technique with less computational cost. It is proved that the BP functions are fundamental tools in approximation problems which have been applied in disparate areas in last decades. This study focuses on the employment of BP functions in control algorithm concerning reduction the computational cost. Magneto-rheological (MR) dampers are one of the well-known semi-active tools that can be used to control the response of civil Structures during earthquake. For validation purposes, numerical simulations of a 5-story shear building frame with MR dampers are presented. The results of suggested method were compared with results obtained by controlling the frame by the optimal control method based on linear quadratic regulator theory. It can be seen from simulation results that the suggested method can be helpful in reducing seismic structural responses. Besides, this method has acceptable accuracy and is in agreement with optimal control method with less computational costs.

  12. Molecular architectures based on π-conjugated block copolymers for global quantum computation

    International Nuclear Information System (INIS)

    Mujica Martinez, C A; Arce, J C; Reina, J H; Thorwart, M

    2009-01-01

    We propose a molecular setup for the physical implementation of a barrier global quantum computation scheme based on the electron-doped π-conjugated copolymer architecture of nine blocks PPP-PDA-PPP-PA-(CCH-acene)-PA-PPP-PDA-PPP (where each block is an oligomer). The physical carriers of information are electrons coupled through the Coulomb interaction, and the building block of the computing architecture is composed by three adjacent qubit systems in a quasi-linear arrangement, each of them allowing qubit storage, but with the central qubit exhibiting a third accessible state of electronic energy far away from that of the qubits' transition energy. The third state is reached from one of the computational states by means of an on-resonance coherent laser field, and acts as a barrier mechanism for the direct control of qubit entanglement. Initial estimations of the spontaneous emission decay rates associated to the energy level structure allow us to compute a damping rate of order 10 -7 s, which suggest a not so strong coupling to the environment. Our results offer an all-optical, scalable, proposal for global quantum computing based on semiconducting π-conjugated polymers.

  13. Thermally induced structural evolution and performance of mesoporous block copolymer-directed alumina perovskite solar cells.

    KAUST Repository

    Tan, Kwan Wee

    2014-04-11

    Structure control in solution-processed hybrid perovskites is crucial to design and fabricate highly efficient solar cells. Here, we utilize in situ grazing incidence wide-angle X-ray scattering and scanning electron microscopy to investigate the structural evolution and film morphologies of methylammonium lead tri-iodide/chloride (CH3NH3PbI(3-x)Cl(x)) in mesoporous block copolymer derived alumina superstructures during thermal annealing. We show the CH3NH3PbI(3-x)Cl(x) material evolution to be characterized by three distinct structures: a crystalline precursor structure not described previously, a 3D perovskite structure, and a mixture of compounds resulting from degradation. Finally, we demonstrate how understanding the processing parameters provides the foundation needed for optimal perovskite film morphology and coverage, leading to enhanced block copolymer-directed perovskite solar cell performance.

  14. Thermally Induced Structural Evolution and Performance of Mesoporous Block Copolymer-Directed Alumina Perovskite Solar Cells

    Science.gov (United States)

    2015-01-01

    Structure control in solution-processed hybrid perovskites is crucial to design and fabricate highly efficient solar cells. Here, we utilize in situ grazing incidence wide-angle X-ray scattering and scanning electron microscopy to investigate the structural evolution and film morphologies of methylammonium lead tri-iodide/chloride (CH3NH3PbI3–xClx) in mesoporous block copolymer derived alumina superstructures during thermal annealing. We show the CH3NH3PbI3–xClx material evolution to be characterized by three distinct structures: a crystalline precursor structure not described previously, a 3D perovskite structure, and a mixture of compounds resulting from degradation. Finally, we demonstrate how understanding the processing parameters provides the foundation needed for optimal perovskite film morphology and coverage, leading to enhanced block copolymer-directed perovskite solar cell performance. PMID:24684494

  15. Fabrication of Hyperbranched Block-Statistical Copolymer-Based Prodrug with Dual Sensitivities for Controlled Release.

    Science.gov (United States)

    Zheng, Luping; Wang, Yunfei; Zhang, Xianshuo; Ma, Liwei; Wang, Baoyan; Ji, Xiangling; Wei, Hua

    2018-01-17

    Dendrimer with hyperbranched structure and multivalent surface is regarded as one of the most promising candidates close to the ideal drug delivery systems, but the clinical translation and scale-up production of dendrimer has been hampered significantly by the synthetic difficulties. Therefore, there is considerable scope for the development of novel hyperbranched polymer that can not only address the drawbacks of dendrimer but maintain its advantages. The reversible addition-fragmentation chain transfer self-condensing vinyl polymerization (RAFT-SCVP) technique has enabled facile preparation of segmented hyperbranched polymer (SHP) by using chain transfer monomer (CTM)-based double-head agent during the past decade. Meanwhile, the design and development of block-statistical copolymers has been proven in our recent studies to be a simple yet effective way to address the extracellular stability vs intracellular high delivery efficacy dilemma. To integrate the advantages of both hyperbranched and block-statistical structures, we herein reported the fabrication of hyperbranched block-statistical copolymer-based prodrug with pH and reduction dual sensitivities using RAFT-SCVP and post-polymerization click coupling. The external homo oligo(ethylene glycol methyl ether methacrylate) (OEGMA) block provides sufficient extracellularly colloidal stability for the nanocarriers by steric hindrance, and the interior OEGMA units incorporated by the statistical copolymerization promote intracellular drug release by facilitating the permeation of GSH and H + for the cleavage of the reduction-responsive disulfide bond and pH-liable carbonate link as well as weakening the hydrophobic encapsulation of drug molecules. The delivery efficacy of the target hyperbranched block-statistical copolymer-based prodrug was evaluated in terms of in vitro drug release and cytotoxicity studies, which confirms both acidic pH and reduction-triggered drug release for inhibiting proliferation of He

  16. Structural Color for Additive Manufacturing: 3D-Printed Photonic Crystals from Block Copolymers.

    Science.gov (United States)

    Boyle, Bret M; French, Tracy A; Pearson, Ryan M; McCarthy, Blaine G; Miyake, Garret M

    2017-03-28

    The incorporation of structural color into 3D printed parts is reported, presenting an alternative to the need for pigments or dyes for colored parts produced through additive manufacturing. Thermoplastic build materials composed of dendritic block copolymers were designed, synthesized, and used to additively manufacture plastic parts exhibiting structural color. The reflection properties of the photonic crystals arise from the periodic nanostructure formed through block copolymer self-assembly during polymer processing. The wavelength of reflected light could be tuned across the visible spectrum by synthetically controlling the block copolymer molecular weight and manufacture parts that reflected violet, green, or orange light with the capacity to serve as selective optical filters and light guides.

  17. Structure and Dynamics Ionic Block co-Polymer Melts: Computational Study

    Science.gov (United States)

    Aryal, Dipak; Perahia, Dvora; Grest, Gary S.

    Tethering ionomer blocks into co-polymers enables engineering of polymeric systems designed to encompass transport while controlling structure. Here the structure and dynamics of symmetric pentablock copolymers melts are probed by fully atomistic molecular dynamics simulations. The center block consists of randomly sulfonated polystyrene with sulfonation fractions f = 0 to 0.55 tethered to a hydrogenated polyisoprene (PI), end caped with poly(t-butyl styrene). We find that melts with f = 0.15 and 0.30 consist of isolated ionic clusters whereas melts with f = 0.55 exhibit a long-range percolating ionic network. Similar to polystyrene sulfonate, a small number of ionic clusters slow the mobility of the center of mass of the co-polymer, however, formation of the ionic clusters is slower and they are often intertwined with PI segments. Surprisingly, the segmental dynamics of the other blocks are also affected. NSF DMR-1611136; NERSC; Palmetto Cluster Clemson University; Kraton Polymers US, LLC.

  18. Anatomy-preserving nonlinear registration of deep brain ROIs using confidence-based block-matching.

    Science.gov (United States)

    Bhattacharjee, Manik; Pitiot, Alain; Roche, Alexis; Dormont, Didier; Bardinet, Eric

    2008-01-01

    Brain atlases are commonly used in a number of applications such as MRI segmentation and surgery targetting. Our goal is to register a basal ganglia atlas to a subject using MR image registration. Existing registration methods are for the most part either too constrained (linear registration) or can deform deep brain ROIs into implausible anatomical shapes. We developed a block-matching registration method suitable for atlas registration, using a new confidence-based regularization of the vector field. The method was used to register a set of 17 manually segmented MRI onto one subject. Results show that basal ganglia structures were better registered than when using an affine registration method.

  19. Automatic content extraction of filled-form images based on clustering component block projection vectors

    Science.gov (United States)

    Peng, Hanchuan; He, Xiaofeng; Long, Fuhui

    2003-12-01

    Automatic understanding of document images is a hard problem. Here we consider a sub-problem, automatically extracting content from filled form images. Without pre-selected templates or sophisticated structural/semantic analysis, we propose a novel approach based on clustering the component-block-projection-vectors. By combining spectral clustering and minimal spanning tree clustering, we generate highly accurate clusters, from which the adaptive templates are constructed to extract the filled-in content. Our experiments show this approach is effective for a set of 1040 US IRS tax form images belonging to 208 types.

  20. Synthesis of polyether-based block copolymers based on poly(propylene oxide) and terephthalates

    NARCIS (Netherlands)

    van der Schuur, J.M.; Feijen, Jan; Gaymans, R.J.

    2005-01-01

    Poly(propylene oxide) (PPO) is a low reactive telechelic polyether and the synthesis of high molecular weight poly(propylene oxide)-based block copolymers was studied. The poly(propylene oxide) used was end capped with 20 wt % ethylene oxide and had a molecular weight of 2300 g/mol (ultra-low monol

  1. A tribo-mechanical analysis of PVA-based building-blocks for implementation in a 2-layered skin model

    NARCIS (Netherlands)

    Morales Hurtado, Marina; de Vries, Erik G.; Zeng, Xiangqiong; van der Heide, Emile

    2016-01-01

    Poly(vinyl) alcohol hydrogel (PVA) is a well-known polymer widely used in the medical field due to its biocompatibility properties and easy manufacturing. In this work, the tribo-mechanical properties of PVA-based blocks are studied to evaluate their suitability as a part of a structure simulating

  2. Sprayable Elastic Conductors Based on Block Copolymer Silver Nanoparticle Composites

    OpenAIRE

    Vural, Mert; Behrens, Adam M.; Ayyub, Omar B.; Ayoub, Joseph J.; Kofinas, Peter

    2014-01-01

    Block copolymer silver nanoparticle composite elastic conductors were fabricated through solution blow spinning and subsequent nanoparticle nucleation. The reported technique allows for conformal deposition onto nonplanar substrates. We additionally demonstrated the ability to tune the strain dependence of the electrical properties by adjusting nanoparticle precursor concentration or localized nanoparticle nucleation. The stretchable fiber mats were able to display electrical conductivity val...

  3. Hydrophilic segmented block copolymers based on poly(ethylene oxide)

    NARCIS (Netherlands)

    Husken, D.

    2006-01-01

    Segmented block copolymers consist of alternating flexible segments and crystallisable rigid segments. The flexible segments have a low glass transition temperature and are used to obtain flexible materials. The rigid segments can crystallise and act as thermal-reversible physical crosslinks, giving

  4. Shear devices for in situ structural studies of block copolymer melts and solutions

    DEFF Research Database (Denmark)

    Mortensen, K.; Almdal, K.; Bates, F.S.

    1995-01-01

    Structural studies of soft material while exposed in situ to stretch or shear provide a new experimental technique which gives important insight into polymer dynamics. Such devices can be used for making single-domain block-copolymer and colloidal mesophases, and to study various growth mechanism....... In addition, combined structure and shear instruments can give detailed insight into the influence of fluctuations. Two types of shear device, the Couette cell and a parallel plate device, are presented, and some applications are shown....

  5. Structure-property relationships in novel polymers and block copolymers from ring-opening metathesis polymerization

    Science.gov (United States)

    Bishop, John Paul

    2011-12-01

    The desire to tune macroscopic properties by controlling the underlying microscopic structure is a driving force in many different areas of scientific research, including polymer science. In living ring-opening metathesis polymerization (ROMP), the subject of this dissertation, there are a variety of different ways to alter the microscopic structure through synthesis. This is in part due to the presence of double bonds in the polymeric backbone, which can influence properties both through their isomeric structures (cis vs. trans) and through their removal by catalytic hydrogenation. Here, we demonstrate the ability to tune a variety of microstructural parameters of our ROMP polymers through synthesis, and investigate the resulting effects on macroscopic properties. ROMP and subsequent hydrogenation provide access to crystalline, glassy, and rubbery polymers, representing essentially the entire spectrum of polymer properties. These include hydrogenated polynorbornene (hPN), a highly crystalline polymer with Tm° = 156°C; hydrogenated poly(5-hexylnorbornene) (hPHN), a rubbery amorphous polymer with Tg = -22°C; and hydrogenated polymethyltetracyclododecene (hPMTD), a glassy polymer with Tg = 163°C. The microstructure of block copolymers of hPN, hPHN, and hPMTD can be controlled by varying block sequence, block lengths, and number of blocks. We used this control to design and synthesize thermoplastic elastomers (TPEs) containing both crystalline and glassy hard segments, with the aim of capturing the mechanical properties of conventional all-amorphous triblock TPEs, while forming the solid-state structure by crystallization from a single-phase melt. To accomplish this, we synthesized symmetric pentablock copolymers with the architecture crystalline-glassy-rubbery-glassy-crystalline. With this pentablock architecture and appropriate selection of block lengths, crystallization from a single-phase melt causes a layer rich in the glassy block to form around the

  6. Thinned crustal structure and tectonic boundary of the Nansha Block, southern South China Sea

    Science.gov (United States)

    Dong, Miao; Wu, Shi-Guo; Zhang, Jian

    2016-12-01

    The southern South China Sea margin consists of the thinned crustal Nansha Block and a compressional collision zone. The Nansha Block's deep structure and tectonic evolution contains critical information about the South China Sea's rifting. Multiple geophysical data sets, including regional magnetic, gravity and reflection seismic data, reveal the deep structure and rifting processes. Curie point depth (CPD), estimated from magnetic anomalies using a windowed wavenumber-domain algorithm, enables us to image thermal structures. To derive a 3D Moho topography and crustal thickness model, we apply Oldenburg algorithm to the gravity anomaly, which was extracted from the observed free air gravity anomaly data after removing the gravity effect of density variations of sediments, and temperature and pressure variations of the lithospheric mantle. We found that the Moho depth (20 km) is shallower than the CPD (24 km) in the Northwest Borneo Trough, possibly caused by thinned crust, low heat flow and a low vertical geothermal gradient. The Nansha Block's northern boundary is a narrow continent-ocean transition zone constrained by magnetic anomalies, reflection seismic data, gravity anomalies and an interpretation of Moho depth (about 13 km). The block extends southward beneath a gravity-driven deformed sediment wedge caused by uplift on land after a collision, with a contribution from deep crustal flow. Its southwestern boundary is close to the Lupar Line defined by a significant negative reduction to the pole (RTP) of magnetic anomaly and short-length-scale variation in crustal thickness, increasing from 18 to 26 km.

  7. Characterization of nanoparticles based on block copolymer micelles

    Czech Academy of Sciences Publication Activity Database

    Pleštil, Josef; Pospíšil, Herman; Kříž, Jaroslav; Kadlec, Petr; Tuzar, Zdeněk; Cubitt, R.

    2001-01-01

    Roč. 17, č. 21 (2001), s. 6699-6704 ISSN 0743-7463 R&D Projects: GA AV ČR KSK4050111; GA ČR GA203/00/1317; GA ČR GA203/01/0536 Institutional research plan: CEZ:AV0Z4050913 Keywords : block copolymer micelles * nanoparticles * small - angle neutron scattering Subject RIV: CD - Macromolecular Chemistry Impact factor: 2.963, year: 2001

  8. "Non-equilibrium" block copolymer micelles with glassy cores: a predictive approach based on theory of equilibrium micelles.

    Science.gov (United States)

    Nagarajan, Ramanathan

    2015-07-01

    Micelles generated in water from most amphiphilic block copolymers are widely recognized to be non-equilibrium structures. Typically, the micelles are prepared by a kinetic process, first allowing molecular scale dissolution of the block copolymer in a common solvent that likes both the blocks and then gradually replacing the common solvent by water to promote the hydrophobic blocks to aggregate and create the micelles. The non-equilibrium nature of the micelle originates from the fact that dynamic exchange between the block copolymer molecules in the micelle and the singly dispersed block copolymer molecules in water is suppressed, because of the glassy nature of the core forming polymer block and/or its very large hydrophobicity. Although most amphiphilic block copolymers generate such non-equilibrium micelles, no theoretical approach to a priori predict the micelle characteristics currently exists. In this work, we propose a predictive approach for non-equilibrium micelles with glassy cores by applying the equilibrium theory of micelles in two steps. In the first, we calculate the properties of micelles formed in the mixed solvent while true equilibrium prevails, until the micelle core becomes glassy. In the second step, we freeze the micelle aggregation number at this glassy state and calculate the corona dimension from the equilibrium theory of micelles. The condition when the micelle core becomes glassy is independently determined from a statistical thermodynamic treatment of diluent effect on polymer glass transition temperature. The predictions based on this "non-equilibrium" model compare reasonably well with experimental data for polystyrene-polyethylene oxide diblock copolymer, which is the most extensively studied system in the literature. In contrast, the application of the equilibrium model to describe such a system significantly overpredicts the micelle core and corona dimensions and the aggregation number. The non-equilibrium model suggests ways to

  9. Performance Evaluation of Frequency Transform Based Block Classification of Compound Image Segmentation Techniques

    Science.gov (United States)

    Selwyn, Ebenezer Juliet; Florinabel, D. Jemi

    2018-04-01

    Compound image segmentation plays a vital role in the compression of computer screen images. Computer screen images are images which are mixed with textual, graphical, or pictorial contents. In this paper, we present a comparison of two transform based block classification of compound images based on metrics like speed of classification, precision and recall rate. Block based classification approaches normally divide the compound images into fixed size blocks of non-overlapping in nature. Then frequency transform like Discrete Cosine Transform (DCT) and Discrete Wavelet Transform (DWT) are applied over each block. Mean and standard deviation are computed for each 8 × 8 block and are used as features set to classify the compound images into text/graphics and picture/background block. The classification accuracy of block classification based segmentation techniques are measured by evaluation metrics like precision and recall rate. Compound images of smooth background and complex background images containing text of varying size, colour and orientation are considered for testing. Experimental evidence shows that the DWT based segmentation provides significant improvement in recall rate and precision rate approximately 2.3% than DCT based segmentation with an increase in block classification time for both smooth and complex background images.

  10. Representation of Block-Based Image Features in a Multi-Scale Framework for Built-Up Area Detection

    Directory of Open Access Journals (Sweden)

    Zhongwen Hu

    2016-02-01

    Full Text Available The accurate extraction and mapping of built-up areas play an important role in many social, economic, and environmental studies. In this paper, we propose a novel approach for built-up area detection from high spatial resolution remote sensing images, using a block-based multi-scale feature representation framework. First, an image is divided into small blocks, in which the spectral, textural, and structural features are extracted and represented using a multi-scale framework; a set of refined Harris corner points is then used to select blocks as training samples; finally, a built-up index image is obtained by minimizing the normalized spectral, textural, and structural distances to the training samples, and a built-up area map is obtained by thresholding the index image. Experiments confirm that the proposed approach is effective for high-resolution optical and synthetic aperture radar images, with different scenes and different spatial resolutions.

  11. Heuristic algorithms for feature selection under Bayesian models with block-diagonal covariance structure.

    Science.gov (United States)

    Foroughi Pour, Ali; Dalton, Lori A

    2018-03-21

    Many bioinformatics studies aim to identify markers, or features, that can be used to discriminate between distinct groups. In problems where strong individual markers are not available, or where interactions between gene products are of primary interest, it may be necessary to consider combinations of features as a marker family. To this end, recent work proposes a hierarchical Bayesian framework for feature selection that places a prior on the set of features we wish to select and on the label-conditioned feature distribution. While an analytical posterior under Gaussian models with block covariance structures is available, the optimal feature selection algorithm for this model remains intractable since it requires evaluating the posterior over the space of all possible covariance block structures and feature-block assignments. To address this computational barrier, in prior work we proposed a simple suboptimal algorithm, 2MNC-Robust, with robust performance across the space of block structures. Here, we present three new heuristic feature selection algorithms. The proposed algorithms outperform 2MNC-Robust and many other popular feature selection algorithms on synthetic data. In addition, enrichment analysis on real breast cancer, colon cancer, and Leukemia data indicates they also output many of the genes and pathways linked to the cancers under study. Bayesian feature selection is a promising framework for small-sample high-dimensional data, in particular biomarker discovery applications. When applied to cancer data these algorithms outputted many genes already shown to be involved in cancer as well as potentially new biomarkers. Furthermore, one of the proposed algorithms, SPM, outputs blocks of heavily correlated genes, particularly useful for studying gene interactions and gene networks.

  12. A new block cipher based on chaotic map and group theory

    International Nuclear Information System (INIS)

    Yang Huaqian; Liao Xiaofeng; Wong Kwokwo; Zhang Wei; Wei Pengcheng

    2009-01-01

    Based on the study of some existing chaotic encryption algorithms, a new block cipher is proposed. In the proposed cipher, two sequences of decimal numbers individually generated by two chaotic piecewise linear maps are used to determine the noise vectors by comparing the element of the two sequences. Then a sequence of decimal numbers is used to define a bijection map. The modular multiplication operation in the group Z 2 8 +1 * and permutations are alternately applied on plaintext with block length of multiples of 64 bits to produce ciphertext blocks of the same length. Analysis show that the proposed block cipher does not suffer from the flaws of pure chaotic cryptosystems.

  13. Minimum-block-generated flexible-grouping-based spectrum assignment for flex-grid optical networks

    Science.gov (United States)

    Qiu, Yang; Xu, Jing

    2017-11-01

    We investigate the spectrum fragmentation issue in flex-grid optical networks and propose a minimum-block-generated flexible-grouping-based spectrum assignment algorithm. By dividing the spectrum resources into several flexible groups according to the bandwidth requirements of service requests for their accommodation and minimizing the generated isolated spectrum blocks inside each spectrum group, the proposed algorithm can not only reduce spectrum fragments but also enhance networking performance (e.g. blocking probability) due to the improved spectrum contiguity inside each spectrum group with no traffic disruption or any extra components. The simulation results verify that the proposed algorithm can remarkably reduce spectrum fragments with a low blocking probability.

  14. Warped Discrete Cosine Transform-Based Low Bit-Rate Block Coding Using Image Downsampling

    Directory of Open Access Journals (Sweden)

    Ertürk Sarp

    2007-01-01

    Full Text Available This paper presents warped discrete cosine transform (WDCT-based low bit-rate block coding using image downsampling. While WDCT aims to improve the performance of conventional DCT by frequency warping, the WDCT has only been applicable to high bit-rate coding applications because of the overhead required to define the parameters of the warping filter. Recently, low bit-rate block coding based on image downsampling prior to block coding followed by upsampling after the decoding process is proposed to improve the compression performance for low bit-rate block coders. This paper demonstrates that a superior performance can be achieved if WDCT is used in conjunction with image downsampling-based block coding for low bit-rate applications.

  15. Block-structured adaptive meshes and reduced grids for atmospheric general circulation models.

    Science.gov (United States)

    Jablonowski, Christiane; Oehmke, Robert C; Stout, Quentin F

    2009-11-28

    Adaptive mesh refinement techniques offer a flexible framework for future variable-resolution climate and weather models since they can focus their computational mesh on certain geographical areas or atmospheric events. Adaptive meshes can also be used to coarsen a latitude-longitude grid in polar regions. This allows for the so-called reduced grid setups. A spherical, block-structured adaptive grid technique is applied to the Lin-Rood finite-volume dynamical core for weather and climate research. This hydrostatic dynamics package is based on a conservative and monotonic finite-volume discretization in flux form with vertically floating Lagrangian layers. The adaptive dynamical core is built upon a flexible latitude-longitude computational grid and tested in two- and three-dimensional model configurations. The discussion is focused on static mesh adaptations and reduced grids. The two-dimensional shallow water setup serves as an ideal testbed and allows the use of shallow water test cases like the advection of a cosine bell, moving vortices, a steady-state flow, the Rossby-Haurwitz wave or cross-polar flows. It is shown that reduced grid configurations are viable candidates for pure advection applications but should be used moderately in nonlinear simulations. In addition, static grid adaptations can be successfully used to resolve three-dimensional baroclinic waves in the storm-track region.

  16. Compressed-Sensing Reconstruction Based on Block Sparse Bayesian Learning in Bearing-Condition Monitoring.

    Science.gov (United States)

    Sun, Jiedi; Yu, Yang; Wen, Jiangtao

    2017-06-21

    Remote monitoring of bearing conditions, using wireless sensor network (WSN), is a developing trend in the industrial field. In complicated industrial environments, WSN face three main constraints: low energy, less memory, and low operational capability. Conventional data-compression methods, which concentrate on data compression only, cannot overcome these limitations. Aiming at these problems, this paper proposed a compressed data acquisition and reconstruction scheme based on Compressed Sensing (CS) which is a novel signal-processing technique and applied it for bearing conditions monitoring via WSN. The compressed data acquisition is realized by projection transformation and can greatly reduce the data volume, which needs the nodes to process and transmit. The reconstruction of original signals is achieved in the host computer by complicated algorithms. The bearing vibration signals not only exhibit the sparsity property, but also have specific structures. This paper introduced the block sparse Bayesian learning (BSBL) algorithm which works by utilizing the block property and inherent structures of signals to reconstruct CS sparsity coefficients of transform domains and further recover the original signals. By using the BSBL, CS reconstruction can be improved remarkably. Experiments and analyses showed that BSBL method has good performance and is suitable for practical bearing-condition monitoring.

  17. Synthesis of Fluorinated Amphiphilic Block Copolymers Based on PEGMA, HEMA, and MMA via ATRP and CuAAC Click Chemistry

    Directory of Open Access Journals (Sweden)

    Fatime Eren Erol

    2014-01-01

    Full Text Available Synthesis of fluorinated amphiphilic block copolymers via atom transfer radical polymerization (ATRP and Cu(I catalyzed Huisgen 1,3-dipolar cycloaddition (CuAAC was demonstrated. First, a PEGMA and MMA based block copolymer carrying multiple side-chain acetylene moieties on the hydrophobic segment for postfunctionalization was carried out. This involves the synthesis of a series of P(HEMA-co-MMA random copolymers to be employed as macroinitiators in the controlled synthesis of P(HEMA-co-MMA-block-PPEGMA block copolymers by using ATRP, followed by a modification step on the hydroxyl side groups of HEMA via Steglich esterification to afford propargyl side-functional polymer, alkyne-P(HEMA-co-MMA-block-PPEGMA. Finally, click coupling between side-chain acetylene functionalities and 2,3,4,5,6-pentafluorobenzyl azide yielded fluorinated amphiphilic block copolymers. The obtained polymers were structurally characterized by 1H-NMR, 19F-NMR, FT-IR, and GPC. Their thermal characterizations were performed using DSC and TGA.

  18. Remote stabilization of copper paddlewheel based molecular building blocks in metal-organic frameworks

    KAUST Repository

    Gao, Wenyang

    2015-03-24

    Copper paddlewheel based molecular building blocks (MBBs) are ubiquitous and have been widely employed for the construction of highly porous metal-organic frameworks (MOFs). However, most copper paddlewheel based MOFs fail to retain their structural integrity in the presence of water. This instability is directly correlated to the plausible displacement of coordinating carboxylates in the copper paddlewheel MBB, [Cu2(O2C-)4], by the strongly coordinating water molecules. In this comprehensive study, we illustrate the chemical stability control in the rht-MOF platform via strengthening the coordinating bonds within the triangular inorganic MBB, [Cu3O(N4-x(CH)xC-)3] (x = 0, 1, or 2). Remotely, the chemical stabilization propagated into the paddlewheel MBB to afford isoreticular rht-MOFs with remarkably enhanced water/chemical stabilities compared to the prototypal rht-MOF-1. © 2015 American Chemical Society.

  19. Utilization of the Building-Block Approach in Structural Mechanics Research

    Science.gov (United States)

    Rouse, Marshall; Jegley, Dawn C.; McGowan, David M.; Bush, Harold G.; Waters, W. Allen

    2005-01-01

    In the last 20 years NASA has worked in collaboration with industry to develop enabling technologies needed to make aircraft safer and more affordable, extend their lifetime, improve their reliability, better understand their behavior, and reduce their weight. To support these efforts, research programs starting with ideas and culminating in full-scale structural testing were conducted at the NASA Langley Research Center. Each program contained development efforts that (a) started with selecting the material system and manufacturing approach; (b) moved on to experimentation and analysis of small samples to characterize the system and quantify behavior in the presence of defects like damage and imperfections; (c) progressed on to examining larger structures to examine buckling behavior, combined loadings, and built-up structures; and (d) finally moved to complicated subcomponents and full-scale components. Each step along the way was supported by detailed analysis, including tool development, to prove that the behavior of these structures was well-understood and predictable. This approach for developing technology became known as the "building-block" approach. In the Advanced Composites Technology Program and the High Speed Research Program the building-block approach was used to develop a true understanding of the response of the structures involved through experimentation and analysis. The philosophy that if the structural response couldn't be accurately predicted, it wasn't really understood, was critical to the progression of these programs. To this end, analytical techniques including closed-form and finite elements were employed and experimentation used to verify assumptions at each step along the way. This paper presents a discussion of the utilization of the building-block approach described previously in structural mechanics research and development programs at NASA Langley Research Center. Specific examples that illustrate the use of this approach are

  20. Block copolymer self-assembly fundamentals and applications in formulation of nano-structured fluids

    Science.gov (United States)

    Sarkar, Biswajit

    Dispersions of nanoparticles in polymer matrices form hybrid materials that can exhibit superior structural and functional properties and find applications in e.g. thermo-plastics, electronics, polymer electrolytes, catalysis, paint formulations, and drug delivery. Control over the particle location and orientation in the polymeric matrices are essential in order to realize the enhanced mechanical, electrical, and optical properties of the nanohybrids. Block copolymers, composed of two or more different monomers, are promising for controlling particle location and orientation because of their ability to organize into ordered nanostructures. Fundamental questions pertaining to nanoparticle-polymer interfacial interactions remain open and formulate the objectives of our investigation. Particle-polymer enthalpic and entropic interactions control the nanoparticle dispersion in polymer matrices. Synthetic chemical methods for modifying the particle surface in order to control polymer-particle interactions are involved and large scale production is not possible. In the current approach, a physical method is employed to control polymer-particle interactions. The use of commercially available solvents is found to be effective in modifying particle-polymer interfacial interactions. The approach is applicable to a wide range of particle-polymer systems and can thereby enable large scale processing of polymer nanohybrids. The systems of silica nanoparticles dispersed in long-range or short-range self-assembled structures of aqueous poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO) block copolymers (Pluronics) is considered here. The effect of various parameters such as the presence of organic solvents, pH, and particle size on the block copolymer organization and the ensuing particle-polymer interactions are investigated. Favorable surface interactions between the deprotonated silica nanoparticle and PEO-rich domain facilitate particle

  1. Equivalence of the EMD- and NEMD-based decomposition of thermal conductivity into microscopic building blocks.

    Science.gov (United States)

    Matsubara, Hiroki; Kikugawa, Gota; Ishikiriyama, Mamoru; Yamashita, Seiji; Ohara, Taku

    2017-09-21

    Thermal conductivity of a material can be comprehended as being composed of microscopic building blocks relevant to the energy transfer due to a specific microscopic process or structure. The building block is called the partial thermal conductivity (PTC). The concept of PTC is essential to evaluate the contributions of various molecular mechanisms to heat conduction and has been providing detailed knowledge of the contribution. The PTC can be evaluated by equilibrium molecular dynamics (EMD) and non-equilibrium molecular dynamics (NEMD) in different manners: the EMD evaluation utilizes the autocorrelation of spontaneous heat fluxes in an equilibrium state whereas the NEMD one is based on stationary heat fluxes in a non-equilibrium state. However, it has not been fully discussed whether the two methods give the same PTC or not. In the present study, we formulate a Green-Kubo relation, which is necessary for EMD to calculate the PTCs equivalent to those by NEMD. Unlike the existing theories, our formulation is based on the local equilibrium hypothesis to describe a clear connection between EMD and NEMD simulations. The equivalence of the two derivations of PTCs is confirmed by the numerical results for liquid methane and butane. The present establishment of the EMD-NEMD correspondence makes the MD analysis of PTCs a robust way to clarify the microscopic origins of thermal conductivity.

  2. Equivalence of the EMD- and NEMD-based decomposition of thermal conductivity into microscopic building blocks

    Science.gov (United States)

    Matsubara, Hiroki; Kikugawa, Gota; Ishikiriyama, Mamoru; Yamashita, Seiji; Ohara, Taku

    2017-09-01

    Thermal conductivity of a material can be comprehended as being composed of microscopic building blocks relevant to the energy transfer due to a specific microscopic process or structure. The building block is called the partial thermal conductivity (PTC). The concept of PTC is essential to evaluate the contributions of various molecular mechanisms to heat conduction and has been providing detailed knowledge of the contribution. The PTC can be evaluated by equilibrium molecular dynamics (EMD) and non-equilibrium molecular dynamics (NEMD) in different manners: the EMD evaluation utilizes the autocorrelation of spontaneous heat fluxes in an equilibrium state whereas the NEMD one is based on stationary heat fluxes in a non-equilibrium state. However, it has not been fully discussed whether the two methods give the same PTC or not. In the present study, we formulate a Green-Kubo relation, which is necessary for EMD to calculate the PTCs equivalent to those by NEMD. Unlike the existing theories, our formulation is based on the local equilibrium hypothesis to describe a clear connection between EMD and NEMD simulations. The equivalence of the two derivations of PTCs is confirmed by the numerical results for liquid methane and butane. The present establishment of the EMD-NEMD correspondence makes the MD analysis of PTCs a robust way to clarify the microscopic origins of thermal conductivity.

  3. Block-based approach to modelling of granulated fertilizers' quality

    DEFF Research Database (Denmark)

    Kohonen, J.; Reinikainen, S. P.; Høskuldsson, Agnar

    2009-01-01

    be defined through testing the flow rate with, e.g., seed drill. Besides the chemical composition, flowability can be considered as one of the most important characteristics. There are numerous factors affecting the flowability of a granulated fertilizer, several of them related to the particle size...... distribution. Particle size distribution of the granulated product has to be within the customer specification, but is also a highly significant factor to the quality, especially in the presence of moisture. This can affect numerous phenomena, inter alia, agglomeration and aggregation of granules and Ostwald...... size distribution. The goals are to find a reliable model for flowability using this data and to find the most important variables and to identify the effect of blocks to the quality....

  4. Silver based SERS substrates fabricated from block copolymer thin film

    Science.gov (United States)

    Zhang, Xin; Lee, Wonjoo; Lee, Seung Yong; Gao, Zhenghan; Rabin, Oded; Briber, R. M.

    2013-03-01

    Poly (styrene-block-4-vinyl pyridine) (PS-b-P4VP, Mw = 47-b-10 kDa, PDI =1.10) thin films were used to form large-scale long range ordered self-assembled hexagonal patterns of vertically P4VP oriented cylinders in a PS matrix on Si substrates. The P4VP cylindrical domains were crosslinked and quaternized using 1,4-dibromobutane. Negatively charged 15nm gold nanoparticles were attached to the quaternized P4VP domains through Coulombic interactions. Silver was then grown on the gold seeds to create nanometer scale gaps between the nanoparticles. The gap between the nanoparticles was fine tuned by controlling the silver growth time. The substrates showed large enhancement factors in the Raman scattering signal for a broad range of incident wavelengths. Present address: LG Chem Ltd, Information Technology & Electronic Materials R&D, Yuseong-gu Daejeon, South Korea

  5. Design bases - Concrete structures

    International Nuclear Information System (INIS)

    Diaz-Llanos Ros, M.

    1993-01-01

    The most suitable title for Section 2 is 'Design Bases', which covers not only calculation but also the following areas: - Structural design concepts. - Project criteria. - Material specifications. These concepts are developed in more detail in the following sections. The numbering in this document is neither complete nor hierarchical since, for easier cross referencing, it corresponds to the paragraphs of Eurocode 2 Part 1 (hereinafter 'EUR-2') which are commented on. (author)

  6. Self-assembly of block copolymer-based ionic supramolecules based upon multi-tail amphiphiles

    DEFF Research Database (Denmark)

    Asad Ayoubi, M.; Almdal, Kristoffer; Zhu, K.

    2015-01-01

    Utilising simple acid-base titration chemistry, a new family of Linear-b-Amphiphilic Comb (L-b-AC) ionic supramolecules [Soft Matter 2013, 9, 1540-1555] featuring multi-tail side-chains have been synthesized and examined by synchrotron SAXS. To three different parent diblock copolymers of poly......(styrene)-b-poly(methacrylic acid) PS-b-PMAA multi-tail ammonium side-chains of (C8)2-, (C8)4- or (C12)2-type were attached at various side-chain grafting densities (X), making it possible to separate effects of the details of the AC-block architecture from effects of the overall volume fraction of the AC block. The micro...

  7. Characterizing the Three-Dimensional Structure of Block Copolymers via Sequential Infiltration Synthesis and Scanning Transmission Electron Tomography.

    Science.gov (United States)

    Segal-Peretz, Tamar; Winterstein, Jonathan; Doxastakis, Manolis; Ramírez-Hernández, Abelardo; Biswas, Mahua; Ren, Jiaxing; Suh, Hyo Seon; Darling, Seth B; Liddle, J Alexander; Elam, Jeffrey W; de Pablo, Juan J; Zaluzec, Nestor J; Nealey, Paul F

    2015-05-26

    Understanding and controlling the three-dimensional structure of block copolymer (BCP) thin films is critical for utilizing these materials for sub-20 nm nanopatterning in semiconductor devices, as well as in membranes and solar cell applications. Combining an atomic layer deposition (ALD)-based technique for enhancing the contrast of BCPs in transmission electron microscopy (TEM) together with scanning TEM (STEM) tomography reveals and characterizes the three-dimensional structures of poly(styrene-block-methyl methacrylate) (PS-b-PMMA) thin films with great clarity. Sequential infiltration synthesis (SIS), a block-selective technique for growing inorganic materials in BCPs films in an ALD tool and an emerging technique for enhancing the etch contrast of BCPs, was harnessed to significantly enhance the high-angle scattering from the polar domains of BCP films in the TEM. The power of combining SIS and STEM tomography for three-dimensional (3D) characterization of BCP films was demonstrated with the following cases: self-assembled cylindrical, lamellar, and spherical PS-b-PMMA thin films. In all cases, STEM tomography has revealed 3D structures that were hidden underneath the surface, including (1) the 3D structure of defects in cylindrical and lamellar phases, (2) the nonperpendicular 3D surface of grain boundaries in the cylindrical phase, and (3) the 3D arrangement of spheres in body-centered-cubic (BCC) and hexagonal-closed-pack (HCP) morphologies in the spherical phase. The 3D data of the spherical morphologies was compared to coarse-grained simulations and assisted in validating the simulations' parameters. STEM tomography of SIS-treated BCP films enables the characterization of the exact structure used for pattern transfer and can lead to a better understating of the physics that is utilized in BCP lithography.

  8. Combining a popularity-productivity stochastic block model with a discriminative-content model for general structure detection

    Science.gov (United States)

    Chai, Bian-fang; Yu, Jian; Jia, Cai-yan; Yang, Tian-bao; Jiang, Ya-wen

    2013-07-01

    Latent community discovery that combines links and contents of a text-associated network has drawn more attention with the advance of social media. Most of the previous studies aim at detecting densely connected communities and are not able to identify general structures, e.g., bipartite structure. Several variants based on the stochastic block model are more flexible for exploring general structures by introducing link probabilities between communities. However, these variants cannot identify the degree distributions of real networks due to a lack of modeling of the differences among nodes, and they are not suitable for discovering communities in text-associated networks because they ignore the contents of nodes. In this paper, we propose a popularity-productivity stochastic block (PPSB) model by introducing two random variables, popularity and productivity, to model the differences among nodes in receiving links and producing links, respectively. This model has the flexibility of existing stochastic block models in discovering general community structures and inherits the richness of previous models that also exploit popularity and productivity in modeling the real scale-free networks with power law degree distributions. To incorporate the contents in text-associated networks, we propose a combined model which combines the PPSB model with a discriminative model that models the community memberships of nodes by their contents. We then develop expectation-maximization (EM) algorithms to infer the parameters in the two models. Experiments on synthetic and real networks have demonstrated that the proposed models can yield better performances than previous models, especially on networks with general structures.

  9. Formation of 2D nanoparticles with block structure in simultaneous electric explosion of conductors

    Energy Technology Data Exchange (ETDEWEB)

    Kryzhevich, Dmitrij S., E-mail: kryzhev@ispms.ru, E-mail: kost@ispms.ru; Zolnikov, Konstantin P., E-mail: kryzhev@ispms.ru, E-mail: kost@ispms.ru [Institute of Strength Physics and Materials Science SB RAS, Tomsk, 6340455, Russia and National Research Tomsk State University, Tomsk, 634050 (Russian Federation); Abdrashitov, Andrei V. [Institute of Strength Physics and Materials Science SB RAS, Tomsk, 6340455 (Russian Federation); Lerner, Marat I. [Institute of Strength Physics and Materials Science SB RAS, Tomsk, 6340455, Russia and National Research Tomsk Polytechnic University, Tomsk, 634050 (Russian Federation); Psakhie, Sergey G. [Institute of Strength Physics and Materials Science SB RAS, Tomsk, 6340455 (Russian Federation); National Research Tomsk Polytechnic University, Tomsk, 634050 (Russian Federation); Skolkovo Institute of Science and Technology, Skolkovo, 143025 (Russian Federation)

    2014-11-14

    A molecular dynamics simulation of nanoparticle formation in simultaneous electric explosion of conductors is performed. Interatomic interaction is described using potentials calculated in the framework of the embedded atom method. High-rate heating results in failure of the conductors with the formation of nanoparticles. The influence of the heating rate, temperature distribution over the specimen cross-section and the distance between simultaneously exploded conductors on the structure of formed nanoparticles is studied. The calculation results show that the electric explosion of conductors allows the formation of nanoparticles with block structure.

  10. Structure of human telomeric RNA (TERRA): stacking of two G-quadruplex blocks in K(+) solution.

    Science.gov (United States)

    Martadinata, Herry; Phan, Anh Tuân

    2013-04-02

    Telomeric repeat-containing RNAs (TERRA) are transcription products of the telomeres. Human TERRA sequences containing UUAGGG repeats can form parallel-stranded G-quadruplexes. The stacking interaction of such structures was shown to be important for ligand targeting and higher-order arrangement of G-quadruplexes in long TERRA sequences. Here we report on the first high-resolution structure of a stacked G-quadruplex formed by the 10-nucleotide human TERRA sequence r(GGGUUAGGGU) in potassium solution. This structure comprises two dimeric three-layer parallel-stranded G-quadruplex blocks, which stack on each other at their 5'-ends. The adenine in each UUA loop is nearly coplanar with the 5'-end G-tetrad forming an A·(G·G·G·G)·A hexad, thereby increasing the stacking contacts between the two blocks. Interestingly, this stacking and loop conformation is different from all structures previously reported for the free human TERRA but resembles the structure previously determined for a complex between a human TERRA sequence and an acridine ligand. This stacking conformation is a potential target for drugs that recognize or induce the stacking interface.

  11. LeuT-Desipramine Structure Reveals How Antidepressants Block Neurotransmitter Reuptake

    Energy Technology Data Exchange (ETDEWEB)

    Zhou,Z.; Zhen, J.; Karpowich, N.; Goetz, R.; Law, C.; Reith, M.; Wang, D.

    2007-01-01

    Tricyclic antidepressants exert their pharmacological effect -- inhibiting the reuptake of serotonin, norepinephrine, and dopamine -- by directly blocking neurotransmitter transporters (SERT, NET, and DAT, respectively) in the presynaptic membrane. The drug-binding site and the mechanism of this inhibition are poorly understood. We determined the crystal structure at 2.9 angstroms of the bacterial leucine transporter (LeuT), a homolog of SERT, NET, and DAT, in complex with leucine and the antidepressant desipramine. Desipramine binds at the inner end of the extracellular cavity of the transporter and is held in place by a hairpin loop and by a salt bridge. This binding site is separated from the leucine-binding site by the extracellular gate of the transporter. By directly locking the gate, desipramine prevents conformational changes and blocks substrate transport. Mutagenesis experiments on human SERT and DAT indicate that both the desipramine-binding site and its inhibition mechanism are probably conserved in the human neurotransmitter transporters.

  12. Cement stabilized red earth as building block and structural pavement layer

    Directory of Open Access Journals (Sweden)

    G.V. RAMA SUBBARAO

    2014-12-01

    Full Text Available Red Earth is most commonly used as material in the building and road construction. Many a times, the red earth found in various quarries is found not suitable for construction. Cement of 4 and 8% of dry mass of red earth was added to improve its suitability as building block and structural pavement material. To know the influence of waste plastic fiber on cement stabilized red earth, 1% fiber was also added to the mixture. It is shown that the compressive strength of cement stabilized red earth blocks was improved with seven days of curing. The addition of cement to red earth enhanced soaked CBR value. The soaked CBR value of fiber reinforced cement stabilized red earth was about 1.3 to 1.5 times that of unreinforced cement stabilized red earth.

  13. Block-diagonal representations for covariance-based anomalous change detectors

    Energy Technology Data Exchange (ETDEWEB)

    Matsekh, Anna M [Los Alamos National Laboratory; Theiler, James P [Los Alamos National Laboratory

    2010-01-01

    We use singular vectors of the whitened cross-covariance matrix of two hyper-spectral images and the Golub-Kahan permutations in order to obtain equivalent tridiagonal representations of the coefficient matrices for a family of covariance-based quadratic Anomalous Change Detection (ACD) algorithms. Due to the nature of the problem these tridiagonal matrices have block-diagonal structure, which we exploit to derive analytical expressions for the eigenvalues of the coefficient matrices in terms of the singular values of the whitened cross-covariance matrix. The block-diagonal structure of the matrices of the RX, Chronochrome, symmetrized Chronochrome, Whitened Total Least Squares, Hyperbolic and Subpixel Hyperbolic Anomalous Change Detectors are revealed by the white singular value decomposition and Golub-Kahan transformations. Similarities and differences in the properties of these change detectors are illuminated by their eigenvalue spectra. We presented a methodology that provides the eigenvalue spectrum for a wide range of quadratic anomalous change detectors. Table I summarizes these results, and Fig. I illustrates them. Although their eigenvalues differ, we find that RX, HACD, Subpixel HACD, symmetrized Chronochrome, and WTLSQ share the same eigenvectors. The eigen vectors for the two variants of Chronochrome defined in (18) are different, and are different from each other, even though they share many (but not all, unless d{sub x} = d{sub y}) eigenvalues. We demonstrated that it is sufficient to compute SVD of the whitened cross covariance matrix of the data in order to almost immediately obtain highly structured sparse matrices (and their eigenvalue spectra) of the coefficient matrices of these ACD algorithms in the white SVD-transformed coordinates. Converting to the original non-white coordinates, these eigenvalues will be modified in magnitude but not in sign. That is, the number of positive, zero-valued, and negative eigenvalues will be conserved.

  14. Quantum Image Steganography and Steganalysis Based On LSQu-Blocks Image Information Concealing Algorithm

    Science.gov (United States)

    A. AL-Salhi, Yahya E.; Lu, Songfeng

    2016-08-01

    Quantum steganography can solve some problems that are considered inefficient in image information concealing. It researches on Quantum image information concealing to have been widely exploited in recent years. Quantum image information concealing can be categorized into quantum image digital blocking, quantum image stereography, anonymity and other branches. Least significant bit (LSB) information concealing plays vital roles in the classical world because many image information concealing algorithms are designed based on it. Firstly, based on the novel enhanced quantum representation (NEQR), image uniform blocks clustering around the concrete the least significant Qu-block (LSQB) information concealing algorithm for quantum image steganography is presented. Secondly, a clustering algorithm is proposed to optimize the concealment of important data. Finally, we used Con-Steg algorithm to conceal the clustered image blocks. Information concealing located on the Fourier domain of an image can achieve the security of image information, thus we further discuss the Fourier domain LSQu-block information concealing algorithm for quantum image based on Quantum Fourier Transforms. In our algorithms, the corresponding unitary Transformations are designed to realize the aim of concealing the secret information to the least significant Qu-block representing color of the quantum cover image. Finally, the procedures of extracting the secret information are illustrated. Quantum image LSQu-block image information concealing algorithm can be applied in many fields according to different needs.

  15. Mesoporous Silica Formation by Block Copolymers and Cetyltrimethylammonium Bromide as Structure Control Agent

    Directory of Open Access Journals (Sweden)

    Mohamad Ali Semsarzadeh

    2013-01-01

    Full Text Available Block copolymers and cetyltrimethylammonium bromide were used as templates in nano silica structure formation like MCM-41Mobil Composition of Matter, SBA16 Santa Barbara Amorphous and a new compound namely SPB  silicone mesoporous particles, prepared by sol-gel method using PPG-PEG-PPG block copolymer to compare the porosity and regularity of the products together. In this work tetraethylorthosilicate  TEOS, as silica source and alcohol as surface modifying agent were used because of having the main advantage, compared to an ionic template such as etyltrimethylammonium bromide, in producing larger pores  and thicker walls for holding larger catalytic molecules in their pores or increasing  their resistance towards fragmentation. In order to study the copolymer as a template,  SPB structure was prepared and compared with SBA16 which was found to have  broader  pore-size  distribution  and  smaller  specifc  surface  area.  Using  alcohol  in particle production resulted in higher formation rate of micelles with improved  morphology. Nitrogen adsorption-desorption, X-ray diffraction and electron scanning  microscopy confrmed the mesoporous structure and regularity of these synthesized  materials. Finally a mechanism is proposed for the formation of these structures.

  16. Mesoscopic multiphase structures and the interfaces of block and graft copolymers in bulk

    International Nuclear Information System (INIS)

    Matsushita, Yushu

    1996-01-01

    Microphase-separated structures of copolymers with various architectures and their polymer/polymer interfaces were studied. They are SP diblock, PSP triblock, and SPP graft copolymers, where S and P denote polystyrene and poly(2-vinylpyridine), respectively. Morphological observations were carried out by means of transmission electron microscopy and small-angle X-ray scattering. Chain dimensions of component polymers were measured by small-angle neutron scattering and microphase-separated interfaces were observed by neutron reflectivity measurements using deuterium-labeled samples. It was clarified that morphological phase transitions among thermodynamically equilibrium structures for SP diblock and PSP triblock copolymers occur at almost the same compositions; however, those of SPP graft copolymers tend to occur at higher volume fraction of polystyrene, φ s , than those for block copolymers. As for alternating lamellar structures it turned out to be clear that lamellar domain spacings, D's, were scaled as the 2/3 power of the molecular weight of polymers irrespective of their architectures. S block chains of SP diblock and PSP triblock copolymers in lamellar structures were both confirmed to be deformed toward the direction perpendicular to the lamellar interfaces, but it revealed that their volumes were preserved. Further, S/P interfacial thicknesses of SP and PSP were essentially the same to each other and the values defined as the FWHM of the error functions which express the segment density distributions of the interfaces were determined to be about 4 nm. (author)

  17. Self-assembled structures of amphiphilic ionic block copolymers: Theory, self-consistent field modeling and experiment

    NARCIS (Netherlands)

    Borisov, O.V.; Zhulina, E.B.; Leermakers, F.A.M.; Muller, A.H.E.

    2011-01-01

    We present an overview of statistical thermodynamic theories that describe the self-assembly of amphiphilic ionic/hydrophobic diblock copolymers in dilute solution. Block copolymers with both strongly and weakly dissociating (pH-sensitive) ionic blocks are considered. We focus mostly on structural

  18. Carbon-based building blocks for alcohol dehydration

    DEFF Research Database (Denmark)

    Boffa, Vittorio; Mallon, Peter E.; Magnacca, Giuliana

    A biopolymer (HAL), extracted from organic compost with yield ~20%, was used to fabricate composite HAL-graphene oxide (GO) membranes. Upon thermal stabilization, HAL brings high disorder in the membrane structure, thus increasing water permeability. This feature together with the good water/etha....../ethanol perm-selectivity make GO-HAL membranes promising devices for alcohol dehydration....

  19. The design and characterization of protein based block polymers

    Science.gov (United States)

    Haghpanah, Jennifer Shorah

    Over the past decades, protein engineering has provided noteworthy advances in basic science as well as in medicine and industry. Protein engineers are currently focusing their efforts on developing elementary rules to design proteins with a specific structure and function. Proteins derived from natural sources have been used generate a plethora of materials with remarkable structural and functional properties. In the first chapter, we show how we can fabricate protein polymers comprised of two different self-assembling domains (SADs). From our studies, we discover that SADs in different orientations have a large impact on their overall microscopic and macroscopic features. In the second chapter, we explore the impact of cellulose (Tc) on the diblocks EC and CE. We discover that Tc is able to selectively impact the mechanical propertied of CE because CE has smaller particle sizes and more E domain exposed on its surface at RT. In the third chapter, we appended an extra C domain to CE to generate CEC with improved mechanical properties, structure and small molecule recognition.

  20. Error Concealment using Neural Networks for Block-Based Image Coding

    Directory of Open Access Journals (Sweden)

    M. Mokos

    2006-06-01

    Full Text Available In this paper, a novel adaptive error concealment (EC algorithm, which lowers the requirements for channel coding, is proposed. It conceals errors in block-based image coding systems by using neural network. In this proposed algorithm, only the intra-frame information is used for reconstruction of the image with separated damaged blocks. The information of pixels surrounding a damaged block is used to recover the errors using the neural network models. Computer simulation results show that the visual quality and the MSE evaluation of a reconstructed image are significantly improved using the proposed EC algorithm. We propose also a simple non-neural approach for comparison.

  1. Extended structure design with simple molybdenum oxide building blocks and urea as a directing agent.

    Science.gov (United States)

    Veen, Sandra J; Roy, Soumyajit; Filinchuk, Yaroslav; Chernyshov, Dmitry; Petukhov, Andrei V; Versluijs-Helder, Marjan; Broersma, Alfred; Soulimani, Fouad; Visser, Tom; Kegel, Willem K

    2008-08-04

    We report here a simple one-pot directed synthesis of an oxomolybdate urea composite in which elementary molybdenum oxide building blocks are linked together with the aid of urea. This type of directed material design resulted in large rod-like crystals of an inorganic-organic hybrid extended structure of {MoO 3(NH 2-CO-NH 2)} infinity consisting of right- and left-handed helical units. In the crystal structure urea acts both as a glue that links the inorganic molybdenum units into a helix and as a supramolecular linker for the stabilization of the crystal structure as a whole. This type of molecular topology resulted in an unexpectedly high thermal stability.

  2. Structure, Stability, and Reorganization of 0.5 L0 Topography in Block Copolymer Thin Films.

    Science.gov (United States)

    Maher, Michael J; Self, Jeffrey L; Stasiak, Pawel; Blachut, Gregory; Ellison, Christopher J; Matsen, Mark W; Bates, Christopher M; Willson, C Grant

    2016-11-22

    The structure, stability, and reorganization of lamella-forming block copolymer thin film surface topography ("islands" and "holes") were studied under boundary conditions driving the formation of 0.5 L 0 thick structures at short thermal annealing times. Self-consistent field theory predicts that the presence of one perfectly neutral surface renders 0.5 L 0 topography thermodynamically stable relative to 1 L 0 thick features, in agreement with previous experimental observations. The calculated through-film structures match cross-sectional scanning electron micrographs, collectively demonstrating the pinning of edge dislocations at the neutral surface. Remarkably, near-neutral surface compositions exhibit 0.5 L 0 topography metastability upon extended thermal treatment, slowly transitioning to 1 L 0 islands or holes as evidenced by optical and atomic force microscopy. Surface restructuring is rationalized by invoking commensurability effects imposed by slightly preferential surfaces. The results described herein clarify the impact of interfacial interactions on block copolymer self-assembly and solidify an understanding of 0.5 L 0 topography, which is frequently used to determine neutral surface compositions of considerable importance to contemporary technological applications.

  3. Small angle neutron scattering study of the micelle structure of amphiphilic block copolymers

    International Nuclear Information System (INIS)

    Yamaoka, H.; Matsuoka, H.; Sumaru, K.; Hanada, S.

    1994-01-01

    The amphiphilic block copolymers of vinyl ether were prepared by living cationic polymerization. The partially deuterated copolymers for SANS experiments were especially synthesized by introducing deuterated phenyl units in the hydrophobic chain. SANS measurements were performed for aqueous solutions of these copolymers by changing H 2 O/D 2 O ratios. The SANS profiles indicate that the micelles in the present system exhibit a core-shell structure and that the size and shape of micelles are largely dependent on the length of hydrophobic chain. The micelle of shorter hydrophobic chain was found to be nearly spherical, whereas the micelle of longer hydrophobic chain was confirmed to have an ellipsoidal shape

  4. Universal block diagram based modeling and simulation schemes for fractional-order control systems.

    Science.gov (United States)

    Bai, Lu; Xue, Dingyü

    2017-05-08

    Universal block diagram based schemes are proposed for modeling and simulating the fractional-order control systems in this paper. A fractional operator block in Simulink is designed to evaluate the fractional-order derivative and integral. Based on the block, the fractional-order control systems with zero initial conditions can be modeled conveniently. For modeling the system with nonzero initial conditions, the auxiliary signal is constructed in the compensation scheme. Since the compensation scheme is very complicated, therefore the integrator chain scheme is further proposed to simplify the modeling procedures. The accuracy and effectiveness of the schemes are assessed in the examples, the computation results testify the block diagram scheme is efficient for all Caputo fractional-order ordinary differential equations (FODEs) of any complexity, including the implicit Caputo FODEs. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  5. New poly(dimethylsiloxane)/poly(perfluorooctylethyl acrylate) block copolymers: structure and order across multiple length scales in thin films

    KAUST Repository

    Martinelli, Elisa

    2011-01-01

    Three sets of a new class of low surface tension block copolymers were synthesized consisting of a poly(dimethylsiloxane) (PDMS) block and a poly(perfluorooctylethyl acrylate) (AF8) block. The polymers were prepared using a bromo-terminated PDMS macroinitiator, to which was attached an AF8 block grown using atom transfer radical polymerization (ATRP) in such a designed way that the molecular weight and composition of the two polymer blocks were regularly varied. The interplay of both the phase separated microstructure and the mesomorphic character of the fluorinated domains with their effect on surface structure was evaluated using a suite of analytical tools. Surfaces of spin-coated and thermally annealed films were assessed using a combination of X-ray photoelectron spectroscopy (XPS) and near-edge X-ray absorption fine structure (NEXAFS) studies. Both atomic force microscopy (AFM) measurements and grazing incidence small angle X-ray scattering (GISAXS) studies were carried out to evaluate the microstructure of the thin films. Even in block copolymers in which the PDMS block was the majority component, a significant presence of the lower surface energy AF8 block was detected at the film surface. Moreover, the perfluorooctyl helices of the AF8 repeat units were highly oriented at the surface in an ordered, tilted smectic structure, which was compared with those of the bulk powder samples using wide-angle X-ray powder diffraction (WAXD) studies. © 2011 The Royal Society of Chemistry.

  6. Energy decomposition analysis based on a block-localized wavefunction and multistate density functional theory

    OpenAIRE

    Mo, Yirong; Bao, Peng; Gao, Jiali

    2011-01-01

    An interaction energy decomposition analysis method based on the block-localized wavefunction (BLW-ED) approach is described. The first main feature of the BLW-ED method is that it combines concepts of valence bond and molecular orbital theories such that the intermediate and physically intuitive electron-localized states are variationally optimized by self-consistent field calculations. Furthermore, the block-localization scheme can be used both in wave function theory and in density functio...

  7. Copper based superconductors by the combination of blocking and mediating layers

    International Nuclear Information System (INIS)

    Shimizu, K.; Nobumasa, H.; Kawai, T.

    1992-01-01

    Copper based high temperature superconductors are composed of Cu-O 2 sheets in combination with thin atomic mediating layers and thick blocking layers which mediate and intercept interactions between Cu-O 2 sheets, respectively. New possible superconductors can be designed by the stacking of the Cu-O 2 sheets along with the periodic insertion of the mediating layers and different kinds of blocking layers. (orig.)

  8. Effect of autonomic blocking agents and structurally related substances on the “salt arousal of drinking”

    NARCIS (Netherlands)

    Wied, D. de

    The effect of autonomic blocking agents and structurally related substances was studied in rats in which thirst was produced by the administration of a hypertonic sodium chloride solution. Scopolamine, methamphetamine, amphetamine, chlorpromazine, atropine, mecamylamine, hexamethonium, nethalide,

  9. Penta-fibrillar assembly: A Building block collagen based materials

    Indian Academy of Sciences (India)

    There is a smartness in the way the penta-fibrils behave in collagen based biomaterials. It is one of the intriguing nano material with a size of about 4 nano meter diagonal size. There are several intermolecular forces that participate in the penta fibrillar assembly, which derive importance in smart behavior of collagen.

  10. Scanned document compression using block-based hybrid video codec.

    Science.gov (United States)

    Zaghetto, Alexandre; de Queiroz, Ricardo L

    2013-06-01

    This paper proposes a hybrid pattern matching/transform-based compression method for scanned documents. The idea is to use regular video interframe prediction as a pattern matching algorithm that can be applied to document coding. We show that this interpretation may generate residual data that can be efficiently compressed by a transform-based encoder. The efficiency of this approach is demonstrated using H.264/advanced video coding (AVC) as a high-quality single and multipage document compressor. The proposed method, called advanced document coding (ADC), uses segments of the originally independent scanned pages of a document to create a video sequence, which is then encoded through regular H.264/AVC. The encoding performance is unrivaled. Results show that ADC outperforms AVC-I (H.264/AVC operating in pure intramode) and JPEG2000 by up to 2.7 and 6.2 dB, respectively. Superior subjective quality is also achieved.

  11. Block-induced Complex Structures Building the Flare-productive Solar Active Region 12673

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Shuhong; Zhang, Jun [CAS Key Laboratory of Solar Activity, National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China); Zhu, Xiaoshuai [Max-Planck Institute for Solar System Research, D-37077 Göttingen (Germany); Song, Qiao, E-mail: shuhongyang@nao.cas.cn [Key Laboratory of Space Weather, National Center for Space Weather, China Meteorological Administration, Beijing 100081 (China)

    2017-11-10

    Solar active region (AR) 12673 produced 4 X-class, 27 M-class, and numerous lower-class flares during its passage across the visible solar disk in 2017 September. Our study is to answer the questions why this AR was so flare-productive and how the X9.3 flare, the largest one of the past decade, took place. We find that there was a sunspot in the initial several days, and then two bipolar regions emerged nearby it successively. Due to the standing of the pre-existing sunspot, the movement of the bipoles was blocked, while the pre-existing sunspot maintained its quasi-circular shaped umbra only with the disappearance of a part of penumbra. Thus, the bipolar patches were significantly distorted, and the opposite polarities formed two semi-circular shaped structures. After that, two sequences of new bipolar regions emerged within the narrow semi-circular zone, and the bipolar patches separated along the curved channel. The new bipoles sheared and interacted with the previous ones, forming a complex topological system, during which numerous flares occurred. At the highly sheared region, a great deal of free energy was accumulated. On September 6, one negative patch near the polarity inversion line began to rapidly rotate and shear with the surrounding positive fields, and consequently the X9.3 flare erupted. Our results reveal that the block-induced complex structures built the flare-productive AR and the X9.3 flare was triggered by an erupting filament due to the kink instability. To better illustrate this process, a block-induced eruption model is proposed for the first time.

  12. HomBlocks: A multiple-alignment construction pipeline for organelle phylogenomics based on locally collinear block searching.

    Science.gov (United States)

    Bi, Guiqi; Mao, Yunxiang; Xing, Qikun; Cao, Min

    2018-01-01

    Organelle phylogenomic analysis requires precisely constructed multi-gene alignment matrices concatenated by pre-aligned single gene datasets. For non-bioinformaticians, it can take days to weeks to manually create high-quality multi-gene alignments comprising tens or hundreds of homologous genes. Here, we describe a new and highly efficient pipeline, HomBlocks, which uses a homologous block searching method to construct multiple sequence alignment. This approach can automatically recognize locally collinear blocks among organelle genomes and excavate phylogenetically informative regions to construct multiple sequence alignment in a few hours. In addition, HomBlocks supports organelle genomes without annotation and makes adjustment to different taxon datasets, thereby enabling the inclusion of as many common genes as possible. Topology comparison of trees built by conventional multi-gene and HomBlocks alignments implemented in different taxon categories shows that the same efficiency can be achieved by HomBlocks as when using the traditional method. The availability of Homblocks makes organelle phylogenetic analyses more accessible to non-bioinformaticians, thereby promising to lead to a better understanding of phylogenic relationships at an organelle genome level. HomBlocks is implemented in Perl and is supported by Unix-like operative systems, including Linux and macOS. The Perl source code is freely available for download from https://github.com/fenghen360/HomBlocks.git, and documentation and tutorials are available at https://github.com/fenghen360/HomBlocks. yxmao@ouc.edu.cn or fenghen360@126.com. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Transparent nanostructured cellulose acetate films based on the self assembly of PEO-b-PPO-b-PEO block copolymer.

    Science.gov (United States)

    Gutierrez, Junkal; Carrasco-Hernandez, Sheyla; Barud, Hernane S; Oliveira, Rafael L; Carvalho, Renata A; Amaral, André C; Tercjak, Agnieszka

    2017-06-01

    In this study fabrication and characterization of transparent nanostructured composite films based on cellulose triacetate (CTA) and poly(ethylene oxide)-b-poly(propylene oxide)-b-poly(ethylene oxide) (EPE) triblock copolymer were presented. The effect of the addition of EPE triblock copolymer on the thermal stability, morphology, and mechanical properties of cellulose triacetate films was investigated. The triblock EPE was chosen since PEO blocks interact favorably with CTA, whereas, PPO blocks remain immiscible which provokes a microphase separation. This allows to obtain EPE/CTA composite films with ordered microphase-separated structures where PPO spherical microdomains are well-dispersed in PEO/CTA matrix by simple solvent-evaporation process. During this process, PEO block chains selectively interact with CTA by strong interpolymer hydrogen-bonding while PPO block microseparated. The addition even 40wt% of EPE leads to nanostructured EPE/CTA composite. The cytotoxicity assay of CTA and EPE/CTA composite films confirm non-toxic character of designed transparent nanostructured composites based on sustainable matrices. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Structural analysis of cellular blocks for a prestressed cast iron reactor pressure vessel

    International Nuclear Information System (INIS)

    Thomas, R.G.; Head, J.L.

    1979-01-01

    The cast segments from which the prestressed cast iron nuclear reactor pressure vessel may be constructed are not readily amenable to detailed three-dimensional finite element analysis because their complex internal web structure requires a very large number of elements if reasonable aspect ratios are to be retained. A technique has been developed of modelling these blocks using plate bending elements from the ASKA code. By this means it has been possible to study in detail several designs of casting and to identify favourable features. The results of these studies, and others in which assessments are made of the sensitivity of the structure to prestressing load changes and machining errors, are reported. (orig.)

  15. Protein structure-based design of anti-protozoal drugs

    Directory of Open Access Journals (Sweden)

    Verlinde Christophe L. M. J.

    2002-01-01

    Full Text Available The repertory of drugs to fight protozoal diseases such as malaria, Chagas' disease, leishmaniasis, and African trypanosomiasis is woefully inadequate. Now, genome sequencing and structural genomics projects are quickly elucidating new drug targets, providing incredible opportunities for medicinal chemists. Here, we illustrate the power of structure-based drug design in this process by our efforts to selectively block trypanosomal glycolysis.

  16. Crustal Structure across Rivera Plate and Jalisco Block (MEXICO): TsuJal Project

    Science.gov (United States)

    Nuñez-Cornu, F. J.; Nunez, D.; Barba, D. C., Sr.; Trejo, E.; Escalona, F.; Danobeitia, J.; Gutierrez Pena, Q. J.

    2015-12-01

    Located on the western margin of Mexico, the collision zone between Rivera, Cocos and North American plates is a complex tectonic collage with high seismic hazards and potential tsunamigenic sources. During the spring of 2014, within the framework of TSUJAL project, Spanish and Mexican scientists investigated this region with the main objective of defining the crustal architecture of this active margin and recognizing potential structural sources that can trigger earthquakes and tsunamis at the convergence between Rivera plate-Jalisco block with the North American Plate. To achieve these goals, a wide-ranging of geophysical data was acquired in this region both offshore and onshore. In this paper, we present the preliminary results obtained from this project about bathymetric, structural geology and wide-angle seismic data of the southern coast of Bahía de Banderas. A crustal P-wave velocity model for the southern coast of Bahía de Banderas was obtained using WAS data recorded by OBS and land seismic stations for more than 150 km across Rivera Plate and Jalisco Block. The thickness of the slab in this area is about 10 km and presents a dip angle about 8º. Continental crustal thickness below Puerto Vallarta is about 20 km, no evidence of continental Moho was found in this study. This model support that due to the convergence of Rivera Plate against Jalisco Block, the region of Bahía de Banderas is under strong crustal stresses that generate structural lineaments and have the same trends offshore and inland. Most of the seismicity reported can be associated to the main structural lineaments. The Banderas Canyon apparently is in an opening process from west to east, which seems to continue through the Rio Pitillal river valley. There is no seismic or morphological evidence to consider that the Banderas Canyon is a continuation of Vallarta Graben.South of María Cleofas Island, the SC marks the limit between RP and JB, possibly being the result of the RP against JB

  17. Block Access Token Renewal Scheme Based on Secret Sharing in Apache Hadoop

    Directory of Open Access Journals (Sweden)

    Su-Hyun Kim

    2014-07-01

    Full Text Available In a cloud computing environment, user data is encrypted and stored using a large number of distributed servers. Global Internet service companies such as Google and Yahoo have recognized the importance of Internet service platforms and conducted their own research and development to utilize large cluster-based cloud computing platform technologies based on low-cost commercial off-the-shelf nodes. Accordingly, as various data services are now allowed over a distributed computing environment, distributed management of big data has become a major issue. On the other hand, security vulnerability and privacy infringement due to malicious attackers or internal users can occur by means of various usage types of big data. In particular, various security vulnerabilities can occur in the block access token, which is used for the permission control of data blocks in Hadoop. To solve this problem, we have proposed a weight-applied XOR-based efficient distribution storage and recovery scheme in this paper. In particular, various security vulnerabilities can occur in the block access token, which is used for the permission control of data blocks in Hadoop. In this paper, a secret sharing-based block access token management scheme is proposed to overcome such security vulnerabilities.

  18. Semiexperimental equilibrium structures for building blocks of organic and biological molecules: the B2PLYP route.

    Science.gov (United States)

    Penocchio, Emanuele; Piccardo, Matteo; Barone, Vincenzo

    2015-10-13

    The B2PLYP double hybrid functional, coupled with the correlation-consistent triple-ζ cc-pVTZ (VTZ) basis set, has been validated in the framework of the semiexperimental (SE) approach for deriving accurate equilibrium structures of molecules containing up to 15 atoms. A systematic comparison between new B2PLYP/VTZ results and several equilibrium SE structures previously determined at other levels, in particular B3LYP/SNSD and CCSD(T) with various basis sets, has put in evidence the accuracy and the remarkable stability of such model chemistry for both equilibrium structures and vibrational corrections. New SE equilibrium structures for phenylacetylene, pyruvic acid, peroxyformic acid, and phenyl radical are discussed and compared with literature data. Particular attention has been devoted to the discussion of systems for which lack of sufficient experimental data prevents a complete SE determination. In order to obtain an accurate equilibrium SE structure for these situations, the so-called templating molecule approach is discussed and generalized with respect to our previous work. Important applications are those involving biological building blocks, like uracil and thiouracil. In addition, for more general situations the linear regression approach has been proposed and validated.

  19. Gravity evidence for shaping of the crustal structure of the Ameca graben (Jalisco block northern limit). Western Mexico

    Science.gov (United States)

    Alatorre-Zamora, Miguel Angel; Campos-Enríquez, José Oscar; Fregoso-Becerra, Emilia; Quintanar-Robles, Luis; Toscano-Fletes, Roberto; Rosas-Elguera, José

    2018-03-01

    The Ameca tectonic depression (ATD) is located at the NE of the Jalisco Block along the southwestern fringe of the NW-SE trending Tepic-Zacoalco Rift, in the west-central part of the Trans-Mexican Volcanic Belt, western Mexico. To characterize its shallow crustal structure, we conducted a gravity survey based on nine N-S gravity profiles across the western half of the Ameca Valley. The Bouguer residual anomalies are featured by a central low between two zones of positive gravity values with marked gravity gradients. These anomalies have a general NW-SE trend similar to the Tepic-Zacoalco Rift general trend. Basement topography along these profiles was obtained by means of: 1) a Tsuboi's type inverse modeling, and 2) forward modeling. Approximately northward dipping 10° slopes are modeled in the southern half, with south tilted down faulted blocks of the Cretaceous granitic basement and its volcano-sedimentary cover along sub-vertical and intermediate normal faults, whereas southward dipping slopes of almost 15° are observed at the northern half. According to features of the obtained models, this depression corresponds to a slight asymmetric graben. The Ameca Fault is part of the master fault system along its northern limit. The quantitative interpretation shows an approximately 500 to 1100 m thick volcano-sedimentary infill capped by alluvial products. This study has several implications concerning the limit between the Jalisco Block and the Tepic-Zacoalco Rift. The established shallow crustal structure points to the existence of a major listric fault with its detachment surface beneath the Tepic-Zacoalco Rift. The Ameca Fault is interpreted as a secondary listric fault. The models indicate the presence of granitic bodies of the Jalisco Block beneath the TMVB volcanic products of the Tepic-Zacoalco rift. This implies that the limit between these two regional structures is not simple but involves a complex transition zone. A generic model suggests that the

  20. Segmented block copolymers based on poltbutylene terephthalate and telechelic polyesters and polyamides of dimirized fatty acids

    NARCIS (Netherlands)

    Manuel, H.J.; Manuel, H.J.; Gaymans, R.J.

    1993-01-01

    Segmented block copolymers (SBCs) based on poly(butylene terephthalate) (PBT) and telechelics based on dimerized fatty acids have been synthesized in the melt. The dimerized fatty acids were coupled with diols or diamines to synthesize polyesters and polyamides of low molar mass. With these

  1. An enhanced chaotic key-based RC5 block cipher adapted to image encryption

    Science.gov (United States)

    Faragallah, Osama S.

    2012-07-01

    RC5 is a block cipher that has several salient features such as adaptability to process different word lengths with a variable block size, a variable number of rounds and a variable-length secret key. However, RC5 can be broken with various attacks such as correlation attack, timing attack, known plaintext correlation attack and differential attacks, revealing weak security. We aimed to enhance the RC5 block cipher to be more secure and efficient for real-time applications while preserving its advantages. For this purpose, this article introduces a new approach based on strengthening both the confusion and diffusion operations by combining chaos and cryptographic primitive operations to produce round keys with better pseudo-random sequences. Comparative security analysis and performance evaluation of the enhanced RC5 block cipher (ERC5) with RC5, RC6 and chaotic block cipher algorithm (CBCA) are addressed. Several test images are used for inspecting the validity of the encryption and decryption algorithms. The experimental results show the superiority of the suggested enhanced RC5 (ERC5) block cipher to image encryption algorithms such as RC5, RC6 and CBCA from the security analysis and performance evaluation points of view.

  2. FFT-based preconditioners for Toeplitz-Block least square problems

    Energy Technology Data Exchange (ETDEWEB)

    Chan, R.H. (Univ. of Hong Kong (Hong Kong). Dept. of Mathematics); Nagy, J.G.; Plemons, R.J. (Univ. of Minnesota, Minneapolis, MN (United States). Inst. for Mathematics and its Applications)

    1993-12-01

    Discretized two-dimensional deconvolution problems arising, e.g., in image restoration and seismic tomography, can be formulated as least squares computations, min [parallel] b [minus] Tx [parallel][sub 2], where T is often a large-scale rectangular Toeplitz-block matrix. The authors consider solving such block least squares problems by the preconditioned conjugate gradient algorithm using square nonsingular circulant-block and related preconditioners, constructed from the blocks of the rectangular matrix T. Preconditioning with such matrices allows efficient implementation using the one-dimensional or two-dimensional fast Fourier transform (FFT). Two-block preconditioners, related to those proposed by T. Chan and J. Olkin for square nonsingular Toeplitz-block systems, are derived and analyzed. It is shown that, for important classes of T, the singular values of the preconditioned matrix are clustered around one. This extends the authors' earlier work on preconditioners for Toeplitz least squares iterations for one-dimensional problems. It is well known that the resolution of ill-posed deconvolution problems can be substantially improved by regularization to compensate for their ill-posed nature. It is shown that regularization can easily be incorporated into the preconditioners, and a report is given on numerical experiments on a Cray Y-MP. The experiments illustrate good convergence properties of these FFT-based preconditioned iterations.

  3. Structured nanoporous surfaces from hybrid block copolymer micelle films with metal ions.

    Science.gov (United States)

    Kim, Minsoo P; Kim, Hyeong Jun; Kim, Bumjoon J; Yi, Gi-Ra

    2015-03-06

    We present a novel method for producing structured nanoporous thin films using block copolymer (BCP) micelles loaded with metallic ions. The BCP micellar thin films containing gold (Au) ions were prepared by spin-coating poly(styrene-block-4-vinylpyridine) (PS-b-P4VP) micelle solutions in which Au precursors (AuCl4(-)) were selectively loaded onto the P4VP core. When the micellar films were exposed to cetyltrimethylammonium bromide (CTAB) solutions, the Au precursors were selectively extracted from the P4VP domains due to their strong electrostatic interaction with CTAB, leading to the formation of pores in the micelles. Consequently, regularly patterned nanoporous surfaces were formed. By controlling the molecular weight (Mn) of PS-b-P4VP and the amount of Au precursors (λ) that were loaded in the P4VP domains, the pore size and depth could be tuned precisely. In particular, when a sufficient amount of Au precursors was loaded (λ  ≥ 0.3), the porous surface nanostructure was well developed. In addition, the pore size and depth of the nanostructure increased as the λ value increased. For instance, when the λ value increased from 0.3 to 1.0, the pore size increased from 22.8 nm to 28.8 nm, and the pore depth increased from 2.1 nm to 3.2 nm. Interestingly, the transition from the nonporous structures to the porous structures in the micellar film could be reversibly controlled by adding and removing the Au precursors in the film. Moreover, our method for the preparation of nanoporous films can be extended to micellar film by incorporating other metal ions such as silver (Ag) and iron (Fe).

  4. The effect of film thickness and molecular structure on order and disorder in thin films of compositionally asymmetric block copolymers

    Science.gov (United States)

    Mishra, Vindhya

    Directed self-assembly of thin film block copolymers offer a high throughput-low cost route to produce next generation lithographic devices, if one can bring the defect densities in the self assembled patterns below tolerance limits. However, the ability to control the nanoscale structure or morphology in thin film block copolymers presents challenges due to confinement effects on equilibrium behavior. Using structure characterization techniques such as grazing incidence small angle X-ray scattering (GISAXS), transmission electron and atomic force microscopy as well as self-consistent field theory, we have investigated how film thickness, annealing temperature and block copolymer structure affects the equilibrium behavior of asymmetric block copolymer films. Our studies have revealed the complicated dependence of order-disorder transitions, order-order transitions and symmetry transitions on film thickness. We found that the thickness dependent transition in the packing symmetry of spherical morphology diblock copolymers can be suppressed by blending with a small amount of majority block homopolymer, which allowed us to resolve the driving force behind this transition. Defect densities in, and the order-disorder transition temperature of, thin films of graphoepitaxially aligned diblock copolymer cylinders showed surprising sensitivity to the microdomain spacing. Methods to mitigate defect formation in thin films have been identified. The challenge of quantification of structural order in these systems was overcome using GISAXS, which allowed us to study the phenomena of disordering in two and three dimensions. Through studies on block copolymers which exhibit an order-order transition in bulk, we found that that subtle differences in the packing frustration of the spherical and cylindrical phases as well as the higher configurational entropy of free chain ends at the surface can drive the equilibrium configuration in thin films away from the stable bulk structure

  5. Lambda-Dropping: Transforming Recursive Equations into Programs with Block Structure

    DEFF Research Database (Denmark)

    Danvy, Olivier; Schultz, Ulrik Pagh

    1999-01-01

    Lambda-lifting a functional program transforms it into a set of recursive equations. We present the symmetric transformation: lambda-dropping. Lambda-dropping a set of recursive equations restores block structure and lexical scope.For lack of scope, recursive equations must carry around all...... the parameters that any of their callees might possibly need. Both lambda-lifting and lambda-dropping thus require one to compute a transitive closure over the call graph:• for lambda-lifting: to establish the Def/Use path of each free variable (these free variables are then added as parameters to each...... of the functions in the call path);• for lambda-dropping: to establish the Def/Use path of each parameter (parameters whose use occurs in the same scope as their definition do not need to be passed along in the call path).Without free variables, a program is scope-insensitive. Its blocks are then free...

  6. Lambda-Dropping: Transforming Recursive Equations into Programs with Block Structure

    DEFF Research Database (Denmark)

    Danvy, Olivier; Schultz, Ulrik Pagh

    1998-01-01

    Lambda-lifting a functional program transforms it into a set of recursive equations. We present the symmetric transformation: lambda-dropping. Lambda-dropping a set of recursive equations restores block structure and lexical scope.For lack of scope, recursive equations must carry around all...... the parameters that any of their callees might possibly need. Both lambda-lifting and lambda-dropping thus require one to compute a transitive closure over the call graph:• for lambda-lifting: to establish the Def/Use path of each free variable (these free variables are then added as parameters to each...... of the functions in the call path);• for lambda-dropping: to establish the Def/Use path of each parameter (parameters whose use occurs in the same scope as their definition do not need to be passed along in the call path).Without free variables, a program is scope-insensitive. Its blocks are then free...

  7. Lambda-Dropping: Transforming Recursive Equations into Programs with Block Structure

    DEFF Research Database (Denmark)

    Danvy, Olivier; Schultz, Ulrik Pagh

    1997-01-01

    Lambda-lifting a functional program transforms it into a set of recursive equations. We present the symmetric transformation: lambda-dropping. Lambda-dropping a set of recursive equations restores block structure and lexical scope.For lack of scope, recursive equations must carry around all...... the parameters that any of their callees might possibly need. Both lambda-lifting and lambda-dropping thus require one to compute a transitive closure over the call graph:• for lambda-lifting: to establish the Def/Use path of each free variable (these free variables are then added as parameters to each...... of the functions in the call path);• for lambda-dropping: to establish the Def/Use path of each parameter (parameters whose use occurs in the same scope as their definition do not need to be passed along in the call path).Without free variables, a program is scope-insensitive. Its blocks are then free...

  8. Three-dimensional Reconstruction of Block Shape Irregularity and its Effects on Block Impacts Using an Energy-Based Approach

    Science.gov (United States)

    Zhang, Yulong; Liu, Zaobao; Shi, Chong; Shao, Jianfu

    2018-04-01

    This study is devoted to three-dimensional modeling of small falling rocks in block impact analysis in energy view using the particle flow method. The restitution coefficient of rockfall collision is introduced from the energy consumption mechanism to describe rockfall-impacting properties. Three-dimensional reconstruction of falling block is conducted with the help of spherical harmonic functions that have satisfactory mathematical properties such as orthogonality and rotation invariance. Numerical modeling of the block impact to the bedrock is analyzed with both the sphere-simplified model and the 3D reconstructed model. Comparisons of the obtained results suggest that the 3D reconstructed model is advantageous in considering the combination effects of rockfall velocity and rotations during colliding process. Verification of the modeling is carried out with the results obtained from other experiments. In addition, the effects of rockfall morphology, surface characteristics, velocity, and volume, colliding damping and relative angle are investigated. A three-dimensional reconstruction modulus of falling blocks is to be developed and incorporated into the rockfall simulation tools in order to extend the modeling results at block scale to slope scale.

  9. Staining Pattern Classification of Antinuclear Autoantibodies Based on Block Segmentation in Indirect Immunofluorescence Images

    Science.gov (United States)

    Li, Jiaqian; Tseng, Kuo-Kun; Hsieh, Zu Yi; Yang, Ching Wen; Huang, Huang-Nan

    2014-01-01

    Indirect immunofluorescence based on HEp-2 cell substrate is the most commonly used staining method for antinuclear autoantibodies associated with different types of autoimmune pathologies. The aim of this paper is to design an automatic system to identify the staining patterns based on block segmentation compared to the cell segmentation most used in previous research. Various feature descriptors and classifiers are tested and compared in the classification of the staining pattern of blocks and it is found that the technique of the combination of the local binary pattern and the k-nearest neighbor algorithm achieve the best performance. Relying on the results of block pattern classification, experiments on the whole images show that classifier fusion rules are able to identify the staining patterns of the whole well (specimen image) with a total accuracy of about 94.62%. PMID:25474260

  10. The structure of the bacterial heterotrophic block in tundra soils of Yamal Peninsula

    Science.gov (United States)

    Kukharenko, O. S.; Dobrovol'Skaya, T. G.; Golovchenko, A. V.; Stepanov, A. L.; Matyshak, G. V.

    2009-04-01

    The tundra cryogenic soils of Yamal Peninsula have a high pool of prokaryote microorganisms characteristic of ecosystems where the environmental conditions are unfavorable for microbiological processes. The lowering of the cultivation temperature from 20 to 5°C did not affect the number of bacteria and their taxonomic structure. Psychrotolerant gram-negative bacteria represented by oligotrophs and copiotrophs predominated in the bacterial communities. Among the bacteria of the hydrolytic block, only bacilli were isolated upon cultivation on the media. The species spectrum of the Bacillus genus was determined by the capability of its representatives for growth at low temperatures. The bacteria isolated from the cryogenic soils had a high nitrogenase activity, which increased under the lower cultivation temperature. This fact shows that the majority of the bacteria in tundra soils has adapted to functioning at low temperatures.

  11. Passive Copy-Move Forgery Detection Using Halftoning-based Block Truncation Coding Feature

    Science.gov (United States)

    Harjito, Bambang; Prasetyo, Heri

    2017-06-01

    This paper presents a new method on passive copy-move forgery detection by exploiting the effectiveness and usability of Halftoning-based Block Truncation Coding (HBTC) image feature. Copy-move forgery detection precisely locates the large size or flat tampered regions of an image. On our method, the tampered input image is firstly divided into several overlapping image blocks to construct the image feature descriptors. Each image block is further divided into several non-overlapping image blocks for processing HBTC. Two image feature descriptors, namely Color Feature (CF) and Bit Pattern Feature (BF) are computed from the HBTC compressed data-stream of each image block. Lexicography sorting rearranges the image feature descriptors in ascending manner for whole image. The similarity between some tampered image regions is measured based on their CF and BF under specific shift frequency threshold. As documented in the experimental results, the proposed method yields a promising result for detecting the tampered or copy-move forgery regions. It has proved that the HBTC is not only suitable for image compression, but it can also be used in the copy-move forgery detection.

  12. An integrated runtime and compile-time approach for parallelizing structured and block structured applications

    Science.gov (United States)

    Agrawal, Gagan; Sussman, Alan; Saltz, Joel

    1993-01-01

    Scientific and engineering applications often involve structured meshes. These meshes may be nested (for multigrid codes) and/or irregularly coupled (called multiblock or irregularly coupled regular mesh problems). A combined runtime and compile-time approach for parallelizing these applications on distributed memory parallel machines in an efficient and machine-independent fashion was described. A runtime library which can be used to port these applications on distributed memory machines was designed and implemented. The library is currently implemented on several different systems. To further ease the task of application programmers, methods were developed for integrating this runtime library with compilers for HPK-like parallel programming languages. How this runtime library was integrated with the Fortran 90D compiler being developed at Syracuse University is discussed. Experimental results to demonstrate the efficacy of our approach are presented. A multiblock Navier-Stokes solver template and a multigrid code were experimented with. Our experimental results show that our primitives have low runtime communication overheads. Further, the compiler parallelized codes perform within 20 percent of the code parallelized by manually inserting calls to the runtime library.

  13. Robustness of Pluronic Block Copolymer Nanostructure to Structural Changes in Dispersed Nanoparticles

    Science.gov (United States)

    Lafollette, Theresa A.; Walker, Lynn M.

    2009-03-01

    Thermoreversible block copolymers [(PEO)n-(PPO)m-(PEO)n; trade name Pluronic] self assemble into ordered micelle gels. Nanoparticles (3-10nm) are templated in the interstitial spaces of Pluronic micelle gels to form nanocomposite systems. Globular hydrophilic proteins have served as model monodisperse nanoparticles in this work. We have shown that these proteins are templated in the interstitial sites of the cubic packed micelle gels at room temperature. By raising the temperature, the proteins are denatured to study the robustness of the micelle gel to structural changes due to the unfolded protein. Nanoscale structure is determined from small angle neutron scattering (SANS). It was expected that any change in the nanoparticle size would cause a change in the packing of the Pluronic micelle gel. However in SANS experiments, the FCC and BCC Pluronic templates show no nanoscale structural differences between a room temperature sample and a sample that has been heated to denature the protein and then cooled back to room temperature. There is a change in the template at longer length scales as evidenced by a low q upturn in the scattered intensity. The robustness of the micelle gel at different length scales will be discussed.

  14. Middle Jurassic Radiolaria from a siliceous argillite block in a structural melange zone near Viqueque, Timor Leste: Paleogeographic implications

    Science.gov (United States)

    Haig, David W.; Bandini, Alexandre Nicolas

    2013-10-01

    Thin-bedded siliceous argillite forming a large block within a structural melange zone at Viqueque, Timor Leste, has yielded a Middle Jurassic (late Bathonian-early Callovian) radiolarian assemblage belonging to Unitary Association Zone 7. Fifty-five species are recognized and illustrated, forming the most diverse radiolarian fauna yet documented from the Jurassic of Timor. The fauna shows little similarity in species content to the few other assemblages previously listed from the Middle or Late Jurassic of Timor, and also has few species in common with faunas known elsewhere in the region from Rotti, Sumatra, South Kalimantan, and Sula. Based on lithofacies similarities and age, the siliceous argillite succession in the melange block at Viqueque is included in the Noni Group originally described as the lower part of the Palelo Series in West Timor. In terms of lithofacies, the Noni Group is distinct from other stratigraphic units known in Timor. It may be associated with volcanic rocks but age relationships are uncertain, although some of the radiolarian cherts in the Noni Group in West Timor have been reported to include tuffaceous sediment. The deep-water character of the siliceous hemipelagite-pelagite facies, the probable volcanic association, and an age close to that of continental breakup in the region suggest deposition in a newly rifted Indian Ocean. In Timor's tectonostratigraphic classification scheme, the Noni Group is here placed in the "Indian Ocean Megasequence".

  15. Two-state model based on the block-localized wave function method

    Science.gov (United States)

    Mo, Yirong

    2007-06-01

    The block-localized wave function (BLW) method is a variant of ab initio valence bond method but retains the efficiency of molecular orbital methods. It can derive the wave function for a diabatic (resonance) state self-consistently and is available at the Hartree-Fock (HF) and density functional theory (DFT) levels. In this work we present a two-state model based on the BLW method. Although numerous empirical and semiempirical two-state models, such as the Marcus-Hush two-state model, have been proposed to describe a chemical reaction process, the advantage of this BLW-based two-state model is that no empirical parameter is required. Important quantities such as the electronic coupling energy, structural weights of two diabatic states, and excitation energy can be uniquely derived from the energies of two diabatic states and the adiabatic state at the same HF or DFT level. Two simple examples of formamide and thioformamide in the gas phase and aqueous solution were presented and discussed. The solvation of formamide and thioformamide was studied with the combined ab initio quantum mechanical and molecular mechanical Monte Carlo simulations, together with the BLW-DFT calculations and analyses. Due to the favorable solute-solvent electrostatic interaction, the contribution of the ionic resonance structure to the ground state of formamide and thioformamide significantly increases, and for thioformamide the ionic form is even more stable than the covalent form. Thus, thioformamide in aqueous solution is essentially ionic rather than covalent. Although our two-state model in general underestimates the electronic excitation energies, it can predict relative solvatochromic shifts well. For instance, the intense π →π* transition for formamide upon solvation undergoes a redshift of 0.3eV, compared with the experimental data (0.40-0.5eV).

  16. Mesomorphic structure of poly(styrene)-block-poly(4-vinylpyridine) with oligo(ethylene oxide)sulfonic acid side chains as a model for molecularly reinforced polymer electrolyte

    NARCIS (Netherlands)

    Kosonen, H; Valkama, S; Hartikainen, J; Eerikainen, H; Torkkeli, M; Jokela, K; Serimaa, R; Sundholm, F; ten Brinke, G; Ikkala, O; Eerikäinen, Hannele

    2002-01-01

    We report self-organized polymer electrolytes based on poly(styrene)-block-poly(4-vinylpyridine) (PS-block-P4VP). Liquidlike ethylene oxide (EO) oligomers with sulfonic acid end groups are bonded to the P4VP block, leading to comb-shaped supramolecules with the PS-block-P4VP backbone. Lithium

  17. Conservation analysis of dengue virust-cell epitope-based vaccine candidates using peptide block entropy

    DEFF Research Database (Denmark)

    Olsen, Lars Rønn; Zhang, Guang Lan; Keskin, Derin B.

    2011-01-01

    Broad coverage of the pathogen population is particularly important when designing CD8+ T-cell epitope vaccines against viral pathogens. Traditional approaches are based on combinations of highly conserved T-cell epitopes. Peptide block entropy analysis is a novel approach for assembling sets of ...

  18. Prototypic implementations of the building block for component based open Hypermedia systems (BB/CB-OHSs)

    DEFF Research Database (Denmark)

    Mohamed, Omer I. Eldai

    2005-01-01

    In this paper we describe the prototypic implementations of the BuildingBlock (BB/CB-OHSs) that proposed to address some of the Component-based Open Hypermedia Systems (CB-OHSs) issues, including distribution and interoperability [4, 11, 12]. Four service implementations were described below. The...

  19. CO2 permeation properties of poly(ethylene oxide)-based segmented block copolymers

    NARCIS (Netherlands)

    Husken, D.; Visser, Tymen; Wessling, Matthias; Gaymans, R.J.

    2010-01-01

    This paper discusses the gas permeation properties of poly(ethylene oxide) (PEO)-based segmented block copolymers containing monodisperse amide segments. These monodisperse segments give rise to a well phase-separated morphology, comprising a continuous PEO phase with dispersed crystallised amide

  20. Programming Education with a Blocks-Based Visual Language for Mobile Application Development

    Science.gov (United States)

    Mihci, Can; Ozdener, Nesrin

    2014-01-01

    The aim of this study is to assess the impact upon academic success of the use of a reference block-based visual programming tool, namely the MIT App Inventor for Android, as an educational instrument for teaching object-oriented GUI-application development (CS2) concepts to students; who have previously completed a fundamental programming course…

  1. A discrete event simulation design for block-based maintenance planning under random machine usage

    NARCIS (Netherlands)

    de Jonge, Bram

    2015-01-01

    Existing research on block-based preventive maintenance planning generally assumes that machines are either used continuously, or that times until failure do not depend on the actual usage of machines. In practice, however, it is often more realistic to assume that machines are not used continuously

  2. Method for Generating Pseudorandom Sequences with the Assured Period Based on R-blocks

    Directory of Open Access Journals (Sweden)

    M. A. Ivanov

    2011-03-01

    Full Text Available The article describes the characteristics of a new class of fast-acting pseudorandom number generators, based on the use of stochastic adders or R-blocks. A new method for generating pseudorandom sequences with the assured length of period is offered.

  3. Cryptanalysis and improvement on a block cryptosystem based on iteration a chaotic map

    International Nuclear Information System (INIS)

    Wang Yong; Liao Xiaofeng; Xiang Tao; Wong, Kwok-Wo; Yang Degang

    2007-01-01

    Recently, a novel block encryption system has been proposed as an improved version of the chaotic cryptographic method based on iterating a chaotic map. In this Letter, a flaw of this cryptosystem is pointed out and a chosen plaintext attack is presented. Furthermore, a remedial improvement is suggested, which avoids the flaw while keeping all the merits of the original cryptosystem

  4. Anionic polymerization and polyhomologation: An ideal combination to synthesize polyethylene-based block copolymers

    KAUST Repository

    Zhang, H.

    2013-08-07

    A novel one-pot methodology combining anionic polymerization and polyhomologation, through a "bridge" molecule (BF3OEt 2), was developed for the synthesis of polyethylene (PE)-based block copolymers. The anionically synthesized macroanion reacts with the "bridge" molecule to afford a 3-arm star (trimacromolecular borane) which serves as an initiator for the polyhomologation. 2013 The Royal Society of Chemistry.

  5. In-Situ Reflectometry Observation on Structural Changes of Thin Self-Assembled Block Copolymer Films

    International Nuclear Information System (INIS)

    Torikai, N; Yamada, N L; Kawaguchi, D; Takano, A; Matsushita, Y; Watkins, E; Majewski, J P; Okuda, H

    2007-01-01

    The structural changes induced by solvent contact or heating were observed for thin spin-coated polystyrene-block-poly(2-vinylpyridine) diblock copolymer (PS-P2VP) films using in-situ neutron reflectivity and grazing-incidence small-angle X-ray scattering (GISAXS) techniques. The lamellarly-ordered PS-P2VP film showed some structural changes in contact with water though it is a poor solvent for both the component polymers, while the original structure was recovered after drying the film. When toluene was used as a selectively good solvent for PS, the thin film was dissolved into the solvent. On the other hand, the thin as-prepared PS-P2VP film with spherical microdomains exhibited laterally a pair of scattering spots symmetrical relative to the specular reflection ridge in the GISAXS pattern, indicating the existence of some lateral structural correlation in the film. On a temperature jump up to 200 0 C, these two scattering spots started to disappear around the glass transition temperature, and then almost completely vanished at 200 0 C unexpectedly though the PS-P2VP used here should be kept in the strong-segregation state. The spherical structure could be completely disordered or kept ordered but with lateral distortion in its orientation. Being cooled down to a room temperature again, the two scattering spots were recovered, and became more intense with their position shifting slightly to lower Q Y -region than before heating due to the improvement in ordering

  6. Block Copolymer-Based Supramolecular Elastomers with High Extensibility and Large Stress Generation Capability

    Science.gov (United States)

    Noro, Atsushi; Hayashi, Mikihiro

    We prepared block copolymer-based supramolecular elastomers with high extensibility and large stress generation capability. Reversible addition fragmentation chain transfer polymerizations were conducted under normal pressure and high pressure to synthesize several large molecular weight polystyrene-b-[poly(butyl acrylate)-co-polyacrylamide]-b-polystyrene (S-Ba-S) block copolymers. Tensile tests revealed that the largest S-Ba-S with middle block molecular weight of 3140k achieved a breaking elongation of over 2000% with a maximum tensile stress of 3.6 MPa and a toughness of 28 MJ/m3 while the reference sample without any middle block hydrogen bonds, polystyrene-b-poly(butyl acrylate)-b-polystyrene with almost the same molecular weight, was merely viscous and not self-standing. Hence, incorporation of hydrogen bonds into a long soft middle block was found to be beneficial to attain high extensibility and large stress generation capability probably due to concerted combination of entropic changes and internal potential energy changes originaing from the dissociation of multiple hydrogen bonds by elongation. This work was supported by JSPS KAKENHI Grant Numbers 13J02357, 24685035, 15K13785, and 23655213 for M.H. and A.N. A.N. also expresses his gratitude for Tanaka Rubber Science & Technology Award by Enokagaku-Shinko Foundation, Japan.

  7. Experimental and Numerical Studies on Tire Tread Block Friction Characteristics Based on a New Test Device

    Directory of Open Access Journals (Sweden)

    J. Wu

    2014-01-01

    Full Text Available A new device was developed for tire tread block slip friction tests. Then the friction characteristics were investigated under different loads and contact roads. Based on this, a friction model for contact between tire tread block and different road surfaces was developed. A finite element slip friction model of rubber block was developed for studying the tread contact stress, stiffness under different pattern slope angles, and ditch radius. Results indicate that friction coefficient between tread and ice road increases when the temperature decreases; different tread patterns have a certain influence on the friction coefficient; its average difference was less than 10%. Different roads impact the coefficient of friction more significantly; the greater the pattern slope, the greater the radial stiffness.

  8. A block-based JPEG-LS compression technique with lossless region of interest

    Science.gov (United States)

    Deng, Lihua; Huang, Zhenghua; Yao, Shoukui

    2018-03-01

    JPEG-LS lossless compression algorithm is used in many specialized applications that emphasize on the attainment of high fidelity for its lower complexity and better compression ratios than the lossless JPEG standard. But it cannot prevent error diffusion because of the context dependence of the algorithm, and have low compression rate when compared to lossy compression. In this paper, we firstly divide the image into two parts: ROI regions and non-ROI regions. Then we adopt a block-based image compression technique to decrease the range of error diffusion. We provide JPEG-LS lossless compression for the image blocks which include the whole or part region of interest (ROI) and JPEG-LS near lossless compression for the image blocks which are included in the non-ROI (unimportant) regions. Finally, a set of experiments are designed to assess the effectiveness of the proposed compression method.

  9. Growth of monolithic full-color GaN-based LED with intermediate carrier blocking layers

    International Nuclear Information System (INIS)

    El-Ghoroury, Hussein S.; Yeh, Milton; Chen, J. C.; Li, X.; Chuang, Chih-Li

    2016-01-01

    Specially designed intermediate carrier blocking layers (ICBLs) in multi-active regions of III-nitride LEDs were shown to be effective in controlling the carrier injection distribution across the active regions. In principle, the majority of carriers, both holes and electrons, can be guided into targeted quantum wells and recombine to generate light of specific wavelengths at controlled current-densities. Accordingly we proposed and demonstrated a novel monolithic InGaN-based LED to achieve three primary colors of light from one device at selected current densities. This LED structure, which has three different sets of quantum wells separated with ICBLs for three primary red-green-blue (RGB) colors, was grown by metal-organic chemical vapor deposition (MOCVD). Results show that this LED can emit light ranging from 460 to 650 nm to cover the entire visible spectrum. The emission wavelength starts at 650 nm and then decreases to 460 nm or lower as the injection current increases. In addition to three primary colors, many other colors can be obtained by color mixing techniques. To the best of our knowledge, this is the first demonstration of monolithic full-color LED grown by a simple growth technique without using re-growth process.

  10. Analyses of Large Coal-Based SOFCs for High Power Stack Block Development

    Energy Technology Data Exchange (ETDEWEB)

    Recknagle, Kurtis P; Koeppel, Brian J

    2010-10-01

    This report summarizes the numerical modeling and analytical efforts for SOFC stack development performed for the coal-based SOFC program. The stack modeling activities began in 2004, but this report focuses on the most relevant results obtained since August 2008. This includes the latter half of Phase-I and all of Phase-II activities under technical guidance of VPS and FCE. The models developed to predict the thermal-flow-electrochemical behaviors and thermal-mechanical responses of generic planar stacks and towers are described. The effects of cell geometry, fuel gas composition, on-cell reforming, operating conditions, cell performance, seal leak, voltage degradation, boundary conditions, and stack height are studied. The modeling activities to evaluate and achieve technical targets for large stack blocks are described, and results from the latest thermal-fluid-electrochemical and structural models are summarized. Modeling results for stack modifications such as scale-up and component thickness reduction to realize cost reduction are presented. Supporting modeling activities in the areas of cell fabrication and loss of contact are also described.

  11. Chain conformations of the component polymers and the microphase separation structures of homopolymer/block coplymer blends

    International Nuclear Information System (INIS)

    Torikai, Naoya; Mogi, Yasuhiro; Matsushita, Yushu; Noda, Ichiro; Han, C.C.

    1993-01-01

    Microdomain spacings of lamellar structures formed by styrene homopolymer/styrene-2-vinylpyridine diblock copolymer/2-vinylpyridine homopolymer blends were measured by small-angle X-ray scattering (SAXS) and single chain conformations of block copolymers in the same blend system were measured by small-angle neutron scattering (SANS). The molecular weight of diblock copolymers is 78K-72K, and three kinds of styrene homopolymer (S H ) and 2-vinylpyridine homopolymer (P H ) pairs were blended, their molecular weight ratios to that of host block chains were 0.17, 0.38, and 0.78, respectively. Two blend ratios of homopolymer (H)/block copolymer (B), i.e. 1/2 and 1/1 were examined. It was found that the domain spacings of all blends are larger than that of pure block copolymer and that they are increasing with increasing the molecular weight of homopolymers and/or with increasing the volume fraction of homopolymers. Further, block chains in the blends were confirmed to have almost the same chain dimension as that of block chain in pure block copolymer system in the direction parallel to the domain interface irrespective of molecular weight and volume fraction of homopolymers. (author)

  12. Reliability based structural design

    NARCIS (Netherlands)

    Vrouwenvelder, A.C.W.M.

    2013-01-01

    According to ISO 2394, structures shall be designed, constructed and maintained in such a way that they are suited for their use during the design working life in an economic way. To fulfil this requirement one needs insight into the risk and reliability under expected and non-expected actions. A

  13. Structure-directing star-shaped block copolymers: supramolecular vesicles for the delivery of anticancer drugs.

    Science.gov (United States)

    Yang, Chuan; Liu, Shao Qiong; Venkataraman, Shrinivas; Gao, Shu Jun; Ke, Xiyu; Chia, Xin Tian; Hedrick, James L; Yang, Yi Yan

    2015-06-28

    Amphiphilic polycarbonate/PEG copolymer with a star-like architecture was designed to facilitate a unique supramolecular transformation of micelles to vesicles in aqueous solution for the efficient delivery of anticancer drugs. The star-shaped amphipilic block copolymer was synthesized by initiating the ring-opening polymerization of trimethylene carbonate (TMC) from methyl cholate through a combination of metal-free organo-catalytic living ring-opening polymerization and post-polymerization chain-end derivatization strategies. Subsequently, the self-assembly of the star-like polymer in aqueous solution into nanosized vesicles for anti-cancer drug delivery was studied. DOX was physically encapsulated into vesicles by dialysis and drug loading level was significant (22.5% in weight) for DOX. Importantly, DOX-loaded nanoparticles self-assembled from the star-like copolymer exhibited greater kinetic stability and higher DOX loading capacity than micelles prepared from cholesterol-initiated diblock analogue. The advantageous disparity is believed to be due to the transformation of micelles (diblock copolymer) to vesicles (star-like block copolymer) that possess greater core space for drug loading as well as the ability of such supramolecular structures to encapsulate DOX. DOX-loaded vesicles effectively inhibited the proliferation of 4T1, MDA-MB-231 and BT-474 cells, with IC50 values of 10, 1.5 and 1.0mg/L, respectively. DOX-loaded vesicles injected into 4T1 tumor-bearing mice exhibited enhanced accumulation in tumor tissue due to the enhanced permeation and retention (EPR) effect. Importantly, DOX-loaded vesicles demonstrated greater tumor growth inhibition than free DOX without causing significant body weight loss or cardiotoxicity. The unique ability of the star-like copolymer emanating from the methyl cholate core provided the requisite modification in the block copolymer interfacial curvature to generate vesicles of high loading capacity for DOX with significant

  14. Recursive Block-by-Block Integral Equation Solution for Transient Dynamic Analysis With Memory-Type Elements

    National Research Council Canada - National Science Library

    Jarque, Al

    2001-01-01

    .... Using a recursive block-by-block convolution (RBBIEF) solution to the governing nonlinear Volterra integral equation, structural base motion acting through an arbitrary number of nonlinear base isolators can be computed quickly and accurately...

  15. AFM study of excimer laser patterning of block-copolymer: Creation of ordered hierarchical, hybrid, or recessed structures

    International Nuclear Information System (INIS)

    Švanda, Jan; Siegel, Jakub; Švorčík, Vaclav; Lyutakov, Oleksiy

    2016-01-01

    Highlights: • Combination of bottom-up (BCP separation) and top-down (laser patterning) technologies allows obtaining hierarchical structures. • Surface morphologies were determined by the order of patterning steps (laser modification, annealing, surface reconstruction). • Tuning the order of steps enables the reorientation of BCP domain at large scale, fabrication of hierarchical, hybrid or recessed structures. • The obtained structures can find potential applications in nanotechnology, plasmonics, information storage, sensors and smart surfaces. - Abstract: We report fabrication of the varied range of hierarchical structures by combining bottom-up self-assembly of block copolymer poly(styrene-block-vinylpyridine) (PS-b-P4VP) with top-down excimer laser patterning method. Different procedures were tested, where laser treatment was applied before phase separation and after phase separation or phase separation and surface reconstruction. Laser treatment was performed using either polarized laser light with the aim to create periodical pattern on polymer surface or non-polarized light for preferential removing of polystyrene (PS) part from PS-b-P4VP. Additionally, dye was introduced into one part of block copolymer (P4VP) with the aim to modify its response to laser light. Resulting structures were analyzed by XPS, UV–vis and AFM techniques. Application of polarized laser light leads to creation of structures with hierarchical, recessed or hybrid geometries. Non-polarized laser beam allows pronouncing the block copolymer phase separated structure. Tuning the order of steps or individual step conditions enables the efficient reorientation of block-copolymer domain at large scale, fabrication of hierarchical, hybrid or recessed structures. The obtained structures can find potential applications in nanotechnology, photonics, plasmonics, information storage, optical devices, sensors and smart surfaces.

  16. Structural Evolution of Low-Molecular-Weight Poly(ethylene oxide-block-polystyrene Diblock Copolymer Thin Film

    Directory of Open Access Journals (Sweden)

    Hui Wu

    2013-01-01

    Full Text Available The structural evolution of low-molecular-weight poly(ethylene oxide-block-polystyrene (PEO-b-PS diblock copolymer thin film with various initial film thicknesses on silicon substrate under thermal annealing was investigated by atomic force microscopy, optical microscopy, and contact angle measurement. At film thickness below half of the interlamellar spacing of the diblock copolymer (6.2 nm, the entire silicon is covered by a polymer brush with PEO blocks anchored on the Si substrate due to the substrate-induced effect. When the film is thicker than 6.2 nm, a dense polymer brush which is equal to half of an interlamellar layer was formed on the silicon, while the excess material dewet this layer to form droplets. The droplet surface was rich with PS block and the PEO block crystallized inside the bigger droplet to form spherulite.

  17. Electrical-power-system data base for consumables analysis. Volume 1: Electrical equipment list, activity blocks, and time lines

    Science.gov (United States)

    Pipher, M. D.; Green, P. A.; Wolfgram, D. F.

    1975-01-01

    A standardized data base is described which consists of a space shuttle electrical equipment list, activity blocks defining electrical equipment utilization, and activity-block time lines for specific mission analyses. Information is presented to facilitate utilization of the data base, to provide the basis for the electrical equipment utilization to enable interpretation of analyses based on the data contained herein.

  18. Mechanical behavior analysis of small-scale modeling of ceramic block masonry structures: geometries effect

    Directory of Open Access Journals (Sweden)

    E. Rizzatti

    Full Text Available This paper presents the experimental results of a research program with ceramic block masonry under compression. Four different block geometries were investigated. Two of them had circular hollows with different net area. The third one had two rectangular hollow and the last block was with rectangular hollows and a double central webs. The prisms and walls were built with two mortar type 1:1:6 (I and 1:0,5:4 (II (proportions by volume of cement: lime: sand. One:three small scale blocks were used to test block, prisms and walls on compression. It was possible to conclude that the block with double central webs gave better results of compressive strength showing to be more efficient. The mortar didn't influenced the compressive strength of prisms and walls.

  19. Structural analysis of superposed fault systems of the Bornholm horst block, Tornquist Zone, Denmark

    DEFF Research Database (Denmark)

    Graversen, Ole

    2009-01-01

    towards the SE and ESE respectively. The Mesozoic faulting was associated with the development of a horst-graben framework in the Bornholm-Skåne segment of the Sorgenfrei-Tornquist Zone. Mesozoic fault subsidence started in the Rønne Graben in the Triassic. In the Jurassic the Arnager-Sose block became...... and the Lobbæk block (new) along with subsidence of the Holsterhus block and renewed subsidence of the Arnager-Sose block. The Mesozoic series are dipping towards the southwest.The Palaeozoic fault systems were associated with two-dimensional plane strain during ENE-WSW and NNE-SSW extension. By contrast...

  20. Multi-quasiparticle and rotational structures in 179W: Fermi alignment, the K-selection rule and blocking

    International Nuclear Information System (INIS)

    Walker, P.M.; Dracoulis, G.D.; Byrne, A.P.; Fabricius, B.; Kibedi, T.; Stuchbery, A.E.; Rowley, N.

    1994-01-01

    High-spin states in 179 W have been studied following the 170 Er( 13 C,4n) reaction. Rotational bands up to I∼53/2h have been identified, based on 1-, 3-, 5- and 7-quasiparticle structures. Different alignment mechanisms compete in the generation of angular momentum at the yrast line. A Fermi-aligned (i 13/2 ) 2 structure, coupled to high-K and to the 7/2 - [514] orbital, forms the negative-parity yrast sequence above I π =31/2 - . This may be called a ''t-band'' since its description within the cranking model requires a ''tilting'' of the cranking axis. The anomalous decay of the K π =35/2 - 5-quasiparticle isomer is explained as arising from destructive interference of transition amplitudes coupling to the Fermi-aligned structure. Detailed analysis of the excitation energies of the multi-quasiparticle states indicates the quenching of both neutron and proton pair correlations, by comparison with blocking calculations. (orig.)

  1. Numerical modeling of block structure dynamics: Application to the Vrancea region and study of earthquakes sequences in the synthetic catalogs

    International Nuclear Information System (INIS)

    Soloviev, A.A.; Vorobieva, I.A.

    1995-08-01

    A seismically active region is represented as a system of absolutely rigid blocks divided by infinitely thin plane faults. The interaction of the blocks along the fault planes and with the underlying medium is viscous-elastic. The system of blocks moves as a consequence of prescribed motion of boundary blocks and the underlying medium. When for some part of a fault plane the stress surpasses a certain strength level a stress-drop (''a failure'') occurs. It can cause a failure for other parts of fault planes. The failures are considered as earthquakes. As a result of the numerical simulation a synthetic earthquake catalogue is produced. This procedure is applied for numerical modeling of dynamics of the block structure approximating the tectonic structure of the Vrancea region. By numerical experiments the values of the model parameters were obtained which supplied the synthetic earthquake catalog with the space distribution of epicenters close to the real distribution of the earthquake epicenters in the Vrancea region. The frequency-magnitude relations (Gutenberg-Richter curves) obtained for the synthetic and real catalogs have some common features. The sequences of earthquakes arising in the model are studied for some artificial structures. It is found that ''foreshocks'', ''main shocks'', and ''aftershocks'' could be detected among earthquakes forming the sequences. The features of aftershocks, foreshocks, and catalogs of main shocks are analysed. (author). 5 refs, 12 figs, 16 tabs

  2. Nonuniformity correction for an infrared focal plane array based on diamond search block matching.

    Science.gov (United States)

    Sheng-Hui, Rong; Hui-Xin, Zhou; Han-Lin, Qin; Rui, Lai; Kun, Qian

    2016-05-01

    In scene-based nonuniformity correction algorithms, artificial ghosting and image blurring degrade the correction quality severely. In this paper, an improved algorithm based on the diamond search block matching algorithm and the adaptive learning rate is proposed. First, accurate transform pairs between two adjacent frames are estimated by the diamond search block matching algorithm. Then, based on the error between the corresponding transform pairs, the gradient descent algorithm is applied to update correction parameters. During the process of gradient descent, the local standard deviation and a threshold are utilized to control the learning rate to avoid the accumulation of matching error. Finally, the nonuniformity correction would be realized by a linear model with updated correction parameters. The performance of the proposed algorithm is thoroughly studied with four real infrared image sequences. Experimental results indicate that the proposed algorithm can reduce the nonuniformity with less ghosting artifacts in moving areas and can also overcome the problem of image blurring in static areas.

  3. Synthesis, characterizations and biocompatibility of novel biodegradable star block copolymers based on poly[(R)-3-hydroxybutyrate] and poly(epsilon-caprolactone)

    DEFF Research Database (Denmark)

    Wu, Linping; Wang, Liang; Wang, Xiaojuan

    2010-01-01

    Star block copolymers based on poly[(R)-3-hydroxybutyrate] (PHB) and poly(epsilon-caprolactone) (PCL), termed SPHBCL, were successfully synthesized with structural variation on arm numbers and lengths via coupling reactions and ring opening polymerizations. Arm numbers 3, 4 and 6 of SPHBCL were s...

  4. Fabrication of honeycomb-structured poly(ethylene glycol)-block-poly(lactic acid) porous films and biomedical applications for cell growth

    International Nuclear Information System (INIS)

    Yao, Bingjian; Zhu, Qingzeng; Yao, Linli; Hao, Jingcheng

    2015-01-01

    Graphical abstract: - Highlights: • Honeycomb-structured PEG-PLA porous films were fabricated. • The organization of pores depends on molecular weight ratio of PEG-to-PLA block. • The pores in the film were internally decorated with a layer of PEG. • The honeycomb-structured PEG-PLA film was suitable as a substrate for cell growth. - Abstract: A series of poly(ethylene glycol)-block-poly(lactic acid) (PEG-PLA) copolymers with a hydrophobic PLA block of different molecular weights and a fixed length hydrophilic PEG were synthesized successfully and characterized. These amphiphilic block copolymers were used to fabricate honeycomb-structured porous films using the breath figure (BF) templating technique. The surface topology and composition of the highly ordered pattern film were further characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and fluorescence microscopy. The results indicated that the PEG-to-PLA block molecular weight ratio influenced the BF film surface topology. The film with the best ordered pores was obtained with a PEG-to-PLA ratio of 2.0 × 10 3 :3.0 × 10 4 . The self-organization of the hydrophilic PEG chains within the pores was confirmed by XPS and fluorescence labeled PEG. A model is proposed to elucidate the stabilization process of the amphiphilic PEG-PLA aggregated architecture on the water droplet-based templates. In addition, GFP-U87 cell viability has been investigated by MTS test and the cell morphology on the honeycomb-structured PEG-PLA porous film has been evaluated using phase-contrast microscope. This porous film is shown to be suitable as a matrix for cell growth

  5. Fabrication of honeycomb-structured poly(ethylene glycol)-block-poly(lactic acid) porous films and biomedical applications for cell growth

    Energy Technology Data Exchange (ETDEWEB)

    Yao, Bingjian [Key Laboratory of Special Functional Aggregated Materials, Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University, Jinan 250199 (China); College of chemistry, Chemical Engineering and Materials Science, Collaborative Innovation Center of Functionalized Probes for Chemical Imaging, Key Laboratory of Molecular and Nano Probes, Ministry of Education, Shandong Normal University, Jinan 250014 (China); Zhu, Qingzeng, E-mail: qzzhu@sdu.edu.cn [Key Laboratory of Special Functional Aggregated Materials, Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University, Jinan 250199 (China); Yao, Linli [Key Laboratory of the Ministry of Education for Experimental Teratology, Department of Histology and Embryology, Shandong University School of Medicine, 250012 Jinan (China); Hao, Jingcheng [Key Laboratory of Special Functional Aggregated Materials, Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University, Jinan 250199 (China)

    2015-03-30

    Graphical abstract: - Highlights: • Honeycomb-structured PEG-PLA porous films were fabricated. • The organization of pores depends on molecular weight ratio of PEG-to-PLA block. • The pores in the film were internally decorated with a layer of PEG. • The honeycomb-structured PEG-PLA film was suitable as a substrate for cell growth. - Abstract: A series of poly(ethylene glycol)-block-poly(lactic acid) (PEG-PLA) copolymers with a hydrophobic PLA block of different molecular weights and a fixed length hydrophilic PEG were synthesized successfully and characterized. These amphiphilic block copolymers were used to fabricate honeycomb-structured porous films using the breath figure (BF) templating technique. The surface topology and composition of the highly ordered pattern film were further characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and fluorescence microscopy. The results indicated that the PEG-to-PLA block molecular weight ratio influenced the BF film surface topology. The film with the best ordered pores was obtained with a PEG-to-PLA ratio of 2.0 × 10{sup 3}:3.0 × 10{sup 4}. The self-organization of the hydrophilic PEG chains within the pores was confirmed by XPS and fluorescence labeled PEG. A model is proposed to elucidate the stabilization process of the amphiphilic PEG-PLA aggregated architecture on the water droplet-based templates. In addition, GFP-U87 cell viability has been investigated by MTS test and the cell morphology on the honeycomb-structured PEG-PLA porous film has been evaluated using phase-contrast microscope. This porous film is shown to be suitable as a matrix for cell growth.

  6. A block matching-based registration algorithm for localization of locally advanced lung tumors.

    Science.gov (United States)

    Robertson, Scott P; Weiss, Elisabeth; Hugo, Geoffrey D

    2014-04-01

    To implement and evaluate a block matching-based registration (BMR) algorithm for locally advanced lung tumor localization during image-guided radiotherapy. Small (1 cm(3)), nonoverlapping image subvolumes ("blocks") were automatically identified on the planning image to cover the tumor surface using a measure of the local intensity gradient. Blocks were independently and automatically registered to the on-treatment image using a rigid transform. To improve speed and robustness, registrations were performed iteratively from coarse to fine image resolution. At each resolution, all block displacements having a near-maximum similarity score were stored. From this list, a single displacement vector for each block was iteratively selected which maximized the consistency of displacement vectors across immediately neighboring blocks. These selected displacements were regularized using a median filter before proceeding to registrations at finer image resolutions. After evaluating all image resolutions, the global rigid transform of the on-treatment image was computed using a Procrustes analysis, providing the couch shift for patient setup correction. This algorithm was evaluated for 18 locally advanced lung cancer patients, each with 4-7 weekly on-treatment computed tomography scans having physician-delineated gross tumor volumes. Volume overlap (VO) and border displacement errors (BDE) were calculated relative to the nominal physician-identified targets to establish residual error after registration. Implementation of multiresolution registration improved block matching accuracy by 39% compared to registration using only the full resolution images. By also considering multiple potential displacements per block, initial errors were reduced by 65%. Using the final implementation of the BMR algorithm, VO was significantly improved from 77% ± 21% (range: 0%-100%) in the initial bony alignment to 91% ± 8% (range: 56%-100%;p < 0.001). Left-right, anterior-posterior, and

  7. Implementation of evidence-based medicine in a health promotion teaching block for Thai medical students.

    Science.gov (United States)

    Liabsuetrakul, Tippawan; Suntharasaj, Thitima; Sangsupawanich, Pasuree; Kongkamol, Chanon; Pornsawat, Panumad

    2017-12-01

    Evidence-based medicine (EBM) is well known in medical practice. Although health promotion (HP) is promoted worldwide, there is still some debate as to whether EBM is needed or useful in the teaching of health promotion. To assess the perceived usefulness of EBM in the teaching of HP among medical students and faculty members. A comparative study was conducted between two groups of fourth-year medical students in the academic year 2012 during the five-week Health Promotion Teaching Block at Prince of Songkla University, southern Thailand. A one-week EBM course was conducted with half the students in the first week of the block and the other half of the students in the last week of the block. All activities in the HP block were similar except for the different periods of the one-week of EBM teaching. The effect on knowledge, ability and perceived application of EBM in future practice was assessed by student self-evaluations before versus after taking the EBM course, and by faculty member evaluation of the students' end-of-block presentations. All evaluation items were rated from 1 (lowest) to 5 (highest). Data were analyzed using a t-test or Wilcoxon test, as appropriate. The students' self-evaluations of knowledge and ability on EBM between the two groups were similar. The perception that teaching EBM is beneficial in health promotion and future practice increased significantly ( phigher scores for the first group than the second group, although the rating differences were not at the level of significance. Ninety percent of the students believed that EBM was a useful addition to the teaching of HP. Medical students and faculty members perceived that EBM is useful in the HP context. Future studies to evaluate the effect of using evidence-based teaching for health promotion are needed.

  8. The analytic structure of conformal blocks and the generalized Wilson-Fisher fixed points

    Energy Technology Data Exchange (ETDEWEB)

    Gliozzi, Ferdinando [Dipartimento di Fisica, Università di Torino andIstituto Nazionale di Fisica Nucleare - sezione di Torino,Via P. Giuria 1, I-10125 Torino (Italy); Guerrieri, Andrea L. [Department of Physics, Faculty of Science, Chulalongkorn University,Thanon Phayathai, Pathumwan, Bangkok 10330 (Thailand); I.N.F.N. Sezione di Roma Tor Vergata,Via della Ricerca Scientifica, I-00133 Roma (Italy); Petkou, Anastasios C. [Institute of Theoretical Physics, Aristotle University of Thessaloniki,54124 Thessaloniki (Greece); Wen, Congkao [Walter Burke Institute for Theoretical Physics, California Institute of Technology,Pasadena, CA 91125 (United States); Mani L. Bhaumik Institute for Theoretical Physics,Department of Physics and Astronomy, UCLA,Los Angeles, CA 90095 (United States)

    2017-04-11

    We describe in detail the method used in our previous work https://arxiv.org/abs/1611.10344 to study the Wilson-Fisher critical points nearby generalized free CFTs, exploiting the analytic structure of conformal blocks as functions of the conformal dimension of the exchanged operator. Our method is equivalent to the mechanism of conformal multiplet recombination set up by null states. We compute, to the first non-trivial order in the ϵ-expansion, the anomalous dimensions and the OPE coefficients of infinite classes of scalar local operators using just CFT data. We study single-scalar and O(N)-invariant theories, as well as theories with multiple deformations. When available we agree with older results, but we also produce a wealth of new ones. Unitarity and crossing symmetry are not used in our approach and we are able to apply our method to non-unitary theories as well. Some implications of our results for the study of the non-unitary theories containing partially conserved higher-spin currents are briefly mentioned.

  9. Finite Macro-Element Mesh Deformation in a Structured Multi-Block Navier-Stokes Code

    Science.gov (United States)

    Bartels, Robert E.

    2005-01-01

    A mesh deformation scheme is developed for a structured multi-block Navier-Stokes code consisting of two steps. The first step is a finite element solution of either user defined or automatically generated macro-elements. Macro-elements are hexagonal finite elements created from a subset of points from the full mesh. When assembled, the finite element system spans the complete flow domain. Macro-element moduli vary according to the distance to the nearest surface, resulting in extremely stiff elements near a moving surface and very pliable elements away from boundaries. Solution of the finite element system for the imposed boundary deflections generally produces smoothly varying nodal deflections. The manner in which distance to the nearest surface has been found to critically influence the quality of the element deformation. The second step is a transfinite interpolation which distributes the macro-element nodal deflections to the remaining fluid mesh points. The scheme is demonstrated for several two-dimensional applications.

  10. From blood dialysis to desalination: A one-size fits all block copolymer based membrane system

    Science.gov (United States)

    Sanna Kotrappanavar, Nataraj; Zavala-Rivera, Paul; Chonnon, Kevin; Almuhtaseb, Shaheen S. A.; Sivaniah, Easan; University of Cambridge Team; Qatar University Collaboration

    2011-03-01

    Asymmetric membrane with ultrahigh selective self-assembled nanoporous block copolymer layer were developed successfully on polyimide (PI) support, which demonstrated excellent thermal, chemical and mechanical stability. Membranes with specific nano- structural architectures and optimized cascades of block assemblies on the top selective skin have been used largely for separation of colour from aqueous streams, wastewater treatment, desalination, blood filtration and gas separation with dense layer transformation. A consistent and reliable method of membrane preparation and measuring separation performance has been adopted. A homologous series of ethylene oxide oligomers covering a large range was used to characterise MWCO of Membrane and were able to provide many points to give a comprehensive description of the membrane performance in the nanofiltration range.

  11. Tackling student neurophobia in neurosciences block with team-based learning

    Directory of Open Access Journals (Sweden)

    Khurshid Anwar

    2015-07-01

    Full Text Available Introduction: Traditionally, neurosciences is perceived as a difficult course in undergraduate medical education with literature suggesting use of the term “Neurophobia” (fear of neurology among medical students. Instructional strategies employed for the teaching of neurosciences in undergraduate curricula traditionally include a combination of lectures, demonstrations, practical classes, problem-based learning and clinico-pathological conferences. Recently, team-based learning (TBL, a student-centered instructional strategy, has increasingly been regarded by many undergraduate medical courses as an effective method to assist student learning. Methods: In this study, 156 students of year-three neuroscience block were divided into seven male and seven female groups, comprising 11–12 students in each group. TBL was introduced during the 6 weeks of this block, and a total of eight TBL sessions were conducted during this duration. We evaluated the effect of TBL on student learning and correlated it with the student's performance in summative assessment. Moreover, the students’ perceptions regarding the process of TBL was assessed by online survey. Results: We found that students who attended TBL sessions performed better in the summative examinations as compared to those who did not. Furthermore, students performed better in team activities compared to individual testing, with male students performing better with a more favorable impact on their grades in the summative examination. There was an increase in the number of students achieving higher grades (grade B and above in this block when compared to the previous block (51.7% vs. 25%. Moreover, the number of students at risk for lower grades (Grade B- and below decreased in this block when compared to the previous block (30.6% vs. 55%. Students generally elicited a favorable response regarding the TBL process, as well as expressed satisfaction with the content covered and felt that such

  12. Tackling student neurophobia in neurosciences block with team-based learning.

    Science.gov (United States)

    Anwar, Khurshid; Shaikh, Abdul A; Sajid, Muhammad R; Cahusac, Peter; Alarifi, Norah A; Al Shedoukhy, Ahlam

    2015-01-01

    Traditionally, neurosciences is perceived as a difficult course in undergraduate medical education with literature suggesting use of the term "Neurophobia" (fear of neurology among medical students). Instructional strategies employed for the teaching of neurosciences in undergraduate curricula traditionally include a combination of lectures, demonstrations, practical classes, problem-based learning and clinico-pathological conferences. Recently, team-based learning (TBL), a student-centered instructional strategy, has increasingly been regarded by many undergraduate medical courses as an effective method to assist student learning. In this study, 156 students of year-three neuroscience block were divided into seven male and seven female groups, comprising 11-12 students in each group. TBL was introduced during the 6 weeks of this block, and a total of eight TBL sessions were conducted during this duration. We evaluated the effect of TBL on student learning and correlated it with the student's performance in summative assessment. Moreover, the students' perceptions regarding the process of TBL was assessed by online survey. We found that students who attended TBL sessions performed better in the summative examinations as compared to those who did not. Furthermore, students performed better in team activities compared to individual testing, with male students performing better with a more favorable impact on their grades in the summative examination. There was an increase in the number of students achieving higher grades (grade B and above) in this block when compared to the previous block (51.7% vs. 25%). Moreover, the number of students at risk for lower grades (Grade B- and below) decreased in this block when compared to the previous block (30.6% vs. 55%). Students generally elicited a favorable response regarding the TBL process, as well as expressed satisfaction with the content covered and felt that such activities led to improvement in communication and

  13. Image contrast enhancement using adjacent-blocks-based modification for local histogram equalization

    Science.gov (United States)

    Wang, Yang; Pan, Zhibin

    2017-11-01

    Infrared images usually have some non-ideal characteristics such as weak target-to-background contrast and strong noise. Because of these characteristics, it is necessary to apply the contrast enhancement algorithm to improve the visual quality of infrared images. Histogram equalization (HE) algorithm is a widely used contrast enhancement algorithm due to its effectiveness and simple implementation. But a drawback of HE algorithm is that the local contrast of an image cannot be equally enhanced. Local histogram equalization algorithms are proved to be the effective techniques for local image contrast enhancement. However, over-enhancement of noise and artifacts can be easily found in the local histogram equalization enhanced images. In this paper, a new contrast enhancement technique based on local histogram equalization algorithm is proposed to overcome the drawbacks mentioned above. The input images are segmented into three kinds of overlapped sub-blocks using the gradients of them. To overcome the over-enhancement effect, the histograms of these sub-blocks are then modified by adjacent sub-blocks. We pay more attention to improve the contrast of detail information while the brightness of the flat region in these sub-blocks is well preserved. It will be shown that the proposed algorithm outperforms other related algorithms by enhancing the local contrast without introducing over-enhancement effects and additional noise.

  14. An RGB colour image steganography scheme using overlapping block-based pixel-value differencing.

    Science.gov (United States)

    Prasad, Shiv; Pal, Arup Kumar

    2017-04-01

    This paper presents a steganographic scheme based on the RGB colour cover image. The secret message bits are embedded into each colour pixel sequentially by the pixel-value differencing (PVD) technique. PVD basically works on two consecutive non-overlapping components; as a result, the straightforward conventional PVD technique is not applicable to embed the secret message bits into a colour pixel, since a colour pixel consists of three colour components, i.e. red, green and blue. Hence, in the proposed scheme, initially the three colour components are represented into two overlapping blocks like the combination of red and green colour components, while another one is the combination of green and blue colour components, respectively. Later, the PVD technique is employed on each block independently to embed the secret data. The two overlapping blocks are readjusted to attain the modified three colour components. The notion of overlapping blocks has improved the embedding capacity of the cover image. The scheme has been tested on a set of colour images and satisfactory results have been achieved in terms of embedding capacity and upholding the acceptable visual quality of the stego-image.

  15. Block-based floor field model for pedestrian's walking through corner

    Science.gov (United States)

    Li, Shengnan; Li, Xingang; Qu, Yunchao; Jia, Bin

    2015-08-01

    Floor field model, characterized by discretization in both time and space, is very popular in pedestrian modeling. In this paper, the pedestrian's moving behavior of walking through corner is described by a block-based floor field model. In this method, a complicated scenario with corners is divided into different types of blocks, the static floor field of each block is separately calculated, and a boundary rule is incorporated into the model to deal with the connected adjacent blocks. Two typical scenarios, L-type scenario and T-type scenario, are used to investigate the performance of the proposed model. The simulation results showed that the proposed model could well reproduce the empirical pedestrian's moving behavior through corner, i.e., pedestrian may transfer to the far corner instead of queuing up at the near corner when congestion happens. Pedestrians are more uniformly distributed in the whole evacuation process and the total evacuation time could be reduced due to the full utilization of scenarios for both channel and corner.

  16. Compressive Video Recovery Using Block Match Multi-Frame Motion Estimation Based on Single Pixel Cameras

    Directory of Open Access Journals (Sweden)

    Sheng Bi

    2016-03-01

    Full Text Available Compressive sensing (CS theory has opened up new paths for the development of signal processing applications. Based on this theory, a novel single pixel camera architecture has been introduced to overcome the current limitations and challenges of traditional focal plane arrays. However, video quality based on this method is limited by existing acquisition and recovery methods, and the method also suffers from being time-consuming. In this paper, a multi-frame motion estimation algorithm is proposed in CS video to enhance the video quality. The proposed algorithm uses multiple frames to implement motion estimation. Experimental results show that using multi-frame motion estimation can improve the quality of recovered videos. To further reduce the motion estimation time, a block match algorithm is used to process motion estimation. Experiments demonstrate that using the block match algorithm can reduce motion estimation time by 30%.

  17. Prototypic implementations of the building block for component based open Hypermedia systems (BB/CB-OHSs)

    DEFF Research Database (Denmark)

    Mohamed, Omer I. Eldai

    2005-01-01

    In this paper we describe the prototypic implementations of the BuildingBlock (BB/CB-OHSs) that proposed to address some of the Component-based Open Hypermedia Systems (CB-OHSs) issues, including distribution and interoperability [4, 11, 12]. Four service implementations were described below....... These are the math service, navigational service, naming and location service and the storage service in addition to two communication protocols (TCP/IP and JAVA RMI)....

  18. Municipal household solid waste fee based on an increasing block pricing model in Beijing, China.

    Science.gov (United States)

    Chu, Zhujie; Wu, Yunga; Zhuang, Jun

    2017-03-01

    This article aims to design an increasing block pricing model to estimate the waste fee with the consideration of the goals and principles of municipal household solid waste pricing. The increasing block pricing model is based on the main consideration of the per capita disposable income of urban residents, household consumption expenditure, production rate of waste disposal industry, and inflation rate. The empirical analysis is based on survey data of 5000 households in Beijing, China. The results indicate that the current uniform price of waste disposal is set too high for low-income people, and waste fees to the household disposable income or total household spending ratio are too low for the medium- and high-income families. An increasing block pricing model can prevent this kind of situation, and not only solve the problem of lack of funds, but also enhance the residents' awareness of environmental protection. A comparative study based on the grey system model is made by having a preliminary forecast for the waste emissions reduction effect of the pay-as-you-throw programme in the next 5 years of Beijing, China. The results show that the effect of the pay-as-you-throw programme is not only to promote the energy conservation and emissions reduction, but also giving a further improvement of the environmental quality.

  19. A block matching-based registration algorithm for localization of locally advanced lung tumors

    Energy Technology Data Exchange (ETDEWEB)

    Robertson, Scott P.; Weiss, Elisabeth; Hugo, Geoffrey D., E-mail: gdhugo@vcu.edu [Department of Radiation Oncology, Virginia Commonwealth University, Richmond, Virginia, 23298 (United States)

    2014-04-15

    Purpose: To implement and evaluate a block matching-based registration (BMR) algorithm for locally advanced lung tumor localization during image-guided radiotherapy. Methods: Small (1 cm{sup 3}), nonoverlapping image subvolumes (“blocks”) were automatically identified on the planning image to cover the tumor surface using a measure of the local intensity gradient. Blocks were independently and automatically registered to the on-treatment image using a rigid transform. To improve speed and robustness, registrations were performed iteratively from coarse to fine image resolution. At each resolution, all block displacements having a near-maximum similarity score were stored. From this list, a single displacement vector for each block was iteratively selected which maximized the consistency of displacement vectors across immediately neighboring blocks. These selected displacements were regularized using a median filter before proceeding to registrations at finer image resolutions. After evaluating all image resolutions, the global rigid transform of the on-treatment image was computed using a Procrustes analysis, providing the couch shift for patient setup correction. This algorithm was evaluated for 18 locally advanced lung cancer patients, each with 4–7 weekly on-treatment computed tomography scans having physician-delineated gross tumor volumes. Volume overlap (VO) and border displacement errors (BDE) were calculated relative to the nominal physician-identified targets to establish residual error after registration. Results: Implementation of multiresolution registration improved block matching accuracy by 39% compared to registration using only the full resolution images. By also considering multiple potential displacements per block, initial errors were reduced by 65%. Using the final implementation of the BMR algorithm, VO was significantly improved from 77% ± 21% (range: 0%–100%) in the initial bony alignment to 91% ± 8% (range: 56%–100%;p < 0

  20. A block matching-based registration algorithm for localization of locally advanced lung tumors

    International Nuclear Information System (INIS)

    Robertson, Scott P.; Weiss, Elisabeth; Hugo, Geoffrey D.

    2014-01-01

    Purpose: To implement and evaluate a block matching-based registration (BMR) algorithm for locally advanced lung tumor localization during image-guided radiotherapy. Methods: Small (1 cm 3 ), nonoverlapping image subvolumes (“blocks”) were automatically identified on the planning image to cover the tumor surface using a measure of the local intensity gradient. Blocks were independently and automatically registered to the on-treatment image using a rigid transform. To improve speed and robustness, registrations were performed iteratively from coarse to fine image resolution. At each resolution, all block displacements having a near-maximum similarity score were stored. From this list, a single displacement vector for each block was iteratively selected which maximized the consistency of displacement vectors across immediately neighboring blocks. These selected displacements were regularized using a median filter before proceeding to registrations at finer image resolutions. After evaluating all image resolutions, the global rigid transform of the on-treatment image was computed using a Procrustes analysis, providing the couch shift for patient setup correction. This algorithm was evaluated for 18 locally advanced lung cancer patients, each with 4–7 weekly on-treatment computed tomography scans having physician-delineated gross tumor volumes. Volume overlap (VO) and border displacement errors (BDE) were calculated relative to the nominal physician-identified targets to establish residual error after registration. Results: Implementation of multiresolution registration improved block matching accuracy by 39% compared to registration using only the full resolution images. By also considering multiple potential displacements per block, initial errors were reduced by 65%. Using the final implementation of the BMR algorithm, VO was significantly improved from 77% ± 21% (range: 0%–100%) in the initial bony alignment to 91% ± 8% (range: 56%–100%;p < 0.001). Left

  1. A tribo-mechanical analysis of PVA-based building-blocks for implementation in a 2-layered skin model.

    Science.gov (United States)

    Morales Hurtado, M; de Vries, E G; Zeng, X; van der Heide, E

    2016-09-01

    Poly(vinyl) alcohol hydrogel (PVA) is a well-known polymer widely used in the medical field due to its biocompatibility properties and easy manufacturing. In this work, the tribo-mechanical properties of PVA-based blocks are studied to evaluate their suitability as a part of a structure simulating the length scale dependence of human skin. Thus, blocks of pure PVA and PVA mixed with Cellulose (PVA-Cel) were synthesised via freezing/thawing cycles and their mechanical properties were determined by Dynamic Mechanical Analysis (DMA) and creep tests. The dynamic tests addressed to elastic moduli between 38 and 50kPa for the PVA and PVA-Cel, respectively. The fitting of the creep compliance tests in the SLS model confirmed the viscoelastic behaviour of the samples with retardation times of 23 and 16 seconds for the PVA and PVA-Cel, respectively. Micro indentation tests were also achieved and the results indicated elastic moduli in the same range of the dynamic tests. Specifically, values between 45-55 and 56-81kPa were obtained for the PVA and PVA-Cel samples, respectively. The tribological results indicated values of 0.55 at low forces for the PVA decreasing to 0.13 at higher forces. The PVA-Cel blocks showed lower friction even at low forces with values between 0.2 and 0.07. The implementation of these building blocks in the design of a 2-layered skin model (2LSM) is also presented in this work. The 2LSM was stamped with four different textures and their surface properties were evaluated. The hydration of the 2LSM was also evaluated with a corneometer and the results indicated a gradient of hydration comparable to the human skin. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Physical tuning of cellulose-polymer interactions utilizing cationic block copolymers based on PCL and quaternized PDMAEMA.

    Science.gov (United States)

    Utsel, Simon; Bruce, Carl; Pettersson, Torbjörn; Fogelström, Linda; Carlmark, Anna; Malmström, Eva; Wågberg, Lars

    2012-12-01

    In this work, the objective was to synthesize and evaluate the properties of a compatibilizer based on poly(ε-caprolactone) aimed at tuning the surface properties of cellulose fibers used in fiber-reinforced biocomposites. The compatibilizer is an amphiphilic block copolymer consisting of two different blocks which have different functions. One block is cationic, quaternized poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA) and can therefore electrostatically attach to anionic reinforcing materials such as cellulose-based fibers/fibrils under mild conditions in water. The other block consists of poly(ε-caprolactone) (PCL) which can decrease the surface energy of a cellulose surface and also has the ability to form physical entanglements with a PCL surface thereby improving the interfacial adhesion. Atom Transfer Radical Polymerization (ATRP) and Ring-Opening Polymerization (ROP) were used to synthesize three block copolymers with the same length of the cationic PDMAEMA block but with different lengths of the PCL blocks. The block copolymers form cationic micelles in water which can adsorb to anionic surfaces such as silicon oxide and cellulose-model surfaces. After heat treatment, the contact angles of water on the treated surfaces increased significantly, and contact angles close to those of pure PCL were obtained for the block copolymers with longer PCL blocks. AFM force measurements showed a clear entangling behavior between the block copolymers and a PCL surface at about 60 °C, which is important for the formation of an adhesive interface in the final biocomposites. This demonstrates that this type of amphiphilic block copolymer can be used to improve interactions in biocomposites between anionic reinforcing materials such as cellulose-based fibers/fibrils and less polar matrices such as PCL.

  3. Lipid nanoparticles based on butyl-methoxydibenzoylmethane: in vitro UVA blocking effect

    International Nuclear Information System (INIS)

    Niculae, G; Lacatusu, I; Badea, N; Meghea, A

    2012-01-01

    The aim of the present study was to obtain efficient lipid nanoparticles loaded with butyl-methoxydibenzoylmethane (BMDBM) in order to develop cosmetic formulations with enhanced UVA blocking effect. For this purpose, two adequate liquid lipids (medium chain triglycerides and squalene) have been used in combination with two solid lipids (cetyl palmitate and glyceryl stearate) in order to create appropriate nanostructured carriers with a disordered lipid network able to accommodate up to 1.5% BMDBM. The lipid nanoparticles (LNs) were characterized in terms of particle size, zeta potential, entrapment efficiency, loading capacity and in vitro UVA blocking effect. The efficiency of lipid nanoparticles in developing some cosmetic formulations has been evaluated by determining the in vitro erythemal UVA protection factor. In order to quantify the photoprotective effect, some selected cream formulations based on BMDBM-LNs and a conventional emulsion were exposed to photochemical UV irradiation at a low energy to simulate the solar energy during the midday. The results obtained demonstrated the high ability of cream formulations based on BMDBM-LNs to absorb more than 96% of UVA radiation. Moreover, the developed cosmetic formulations manifest an enhanced UVA blocking effect, the erythemal UVA protection factor being four times higher than those specific to conventional emulsions. (paper)

  4. Role of Constant, Random and Blocked Practice in an Electromyography-Based Oral Motor Learning Task.

    Science.gov (United States)

    Kaipa, Ramesh; Mariam Kaipa, Roha

    2017-10-19

    The role of principles of motor learning (PMLs) in speech has received much attention in the past decade. Oral motor learning, however, has not received similar consideration. This study evaluated the role of three practice conditions in an oral motor tracking task. Forty-five healthy adult participants were randomly and equally assigned to one of three practice conditions (constant, blocked, and random) and participated in an electromyography-based task. The study consisted of four sessions, at one session a day for four consecutive days. The first three days sessions included a practice phase, with immediate visual feedback, and an immediate retention phase, without visual feedback. The fourth session did not include practice, but only delayed retention testing, lasting 10-15 minutes, without visual feedback. Random group participants performed better than participants in constant and blocked practice conditions on all the four days. Constant group participants demonstrated superior learning over blocked group participants only on day 4. Findings indicate that random practice facilitates oral motor learning, which is in line with limb/speech motor learning literature. Future research should systematically investigate the outcomes of random practice as a function of different oral and speech-based tasks.

  5. Rapid shear alignment of sub-10 nm cylinder-forming block copolymer films based on thermal expansion mismatch

    Science.gov (United States)

    Nicaise, Samuel M.; Gadelrab, Karim R.; G, Amir Tavakkoli K.; Ross, Caroline A.; Alexander-Katz, Alfredo; Berggren, Karl K.

    2018-01-01

    Directed self-assembly of block copolymers (BCPs) provided by shear-stress can produce aligned sub-10 nm structures over large areas for applications in integrated circuits, next-generation data storage, and plasmonic structures. In this work, we present a fast, versatile BCP shear-alignment process based on coefficient of thermal expansion mismatch of the BCP film, a rigid top coat and a substrate. Monolayer and bilayer cylindrical microdomains of poly(styrene-b-dimethylsiloxane) aligned preferentially in-plane and orthogonal to naturally-forming or engineered cracks in the top coat film, allowing for orientation control over 1 cm2 substrates. Annealing temperatures, up to 275 °C, provided low-defect alignment up to 2 mm away from cracks for rapid (thermal annealing was critical for the observed microdomain alignment.

  6. Synthesis of β-cyclodextrin-Based Star Block Copolymers with Thermo-Responsive Behavior

    Directory of Open Access Journals (Sweden)

    Agnes Wycisk

    2015-05-01

    Full Text Available Star polymers are one example of three-dimensional macromolecules containing several arms with similar molecular weight connected to a central core. Due to their compact structure and their enhanced segment density in comparison to linear polymers of the same molecular weight, they have attracted significant attention during recent years. The preparation of block-arm star copolymers with a permanently hydrophilic block and an “environmentally” sensitive block, which can change its nature from hydrophilic to hydrophobic, leads to nanometer-sized responsive materials with unique properties. These polymers are able to undergo a conformational change or phase transition as a reply to an external stimulus resulting in the formation of core–shell nanoparticles, which further tend to aggregate. Star-shaped copolymers with different cores were synthesized via atom transfer radical polymerization (ATRP. The core-first method chosen as synthetic strategy allows good control over the polymer architecture. First of all the multifunctional initiators were prepared by esterification reaction of the hydroxyl groups with 2-chloropropionyl chloride. Using β-cyclodextrin as core molecules, which possess a well-defined number of functional groups up to 21, allows defining the number of arms per star polymer. In order to prepare stimuli-responsive multi-arm copolymers, containing a stimuli-responsive (poly(N-isopropylacrylamide (PNIPAAm and a non-responsive block (poly(N,N-dimethylacrylamide (PDMAAm, consecutive ATRP was carried out. The polymers were characterized intensively using NMR spectroscopy and size exclusion chromatography (SEC, whereas the temperature-depending aggregation behavior in aqueous solution was determined via turbidimetry and differential scanning calorimetry (DSC.

  7. Dynamic combinatorial chemistry with hydrazones: cholate-based building blocks and libraries.

    Science.gov (United States)

    Simpson, Mark G; Pittelkow, Michael; Watson, Stephen P; Sanders, Jeremy K M

    2010-03-07

    We describe an efficient and general strategy for the synthesis of dimethyl acetal functionalised steroidal hydrazides based on the cholic acid skeleton with the aim of using these compounds as building blocks for dynamic combinatorial chemistry. Deprotection of the acetal protected building blocks with TFA leads to formation of libraries containing macrocyclic N-acyl hydrazone oligomers. The isolation of several of these, and their characterisation using NMR is described. The effects on the equilibrium library distribution by varying the substituents at C-7 and C-12, extending the side-chain with glycine, and inverting the configuration at C-3 are discussed. Finally, we report the exchange properties of these macrocycles and demonstrate new examples of proof-reading and self-sorting in dynamic combinatorial libraries.

  8. Block-based wavelet transform coding of mammograms with region-adaptive quantization

    Science.gov (United States)

    Moon, Nam Su; Song, Jun S.; Kwon, Musik; Kim, JongHyo; Lee, ChoongWoong

    1998-06-01

    To achieve both high compression ratio and information preserving, it is an efficient way to combine segmentation and lossy compression scheme. Microcalcification in mammogram is one of the most significant sign of early stage of breast cancer. Therefore in coding, detection and segmentation of microcalcification enable us to preserve it well by allocating more bits to it than to other regions. Segmentation of microcalcification is performed both in spatial domain and in wavelet transform domain. Peak error controllable quantization step, which is off-line designed, is suitable for medical image compression. For region-adaptive quantization, block- based wavelet transform coding is adopted and different peak- error-constrained quantizers are applied to blocks according to the segmentation result. In view of preservation of microcalcification, the proposed coding scheme shows better performance than JPEG.

  9. Assay for intrinsic factor based on blocking of the R binder of gastric juice by cobinamide

    International Nuclear Information System (INIS)

    Begley, J.A.; Trachtenberg, A.

    1979-01-01

    An in vitro assay for measurement of gastric juice intrinsic factor (IF) was developed based on the ability of the cobinamide (Cbi) [(CN, OH) Cbi] to bind to the gastric juice R-type binders of cobalamin (Cbl) and not to the IF binder. Subsequently added radioactive Cbl, CN-[ 57 Co] Cbl, binds only to the IF binders and allows for direct measurement of this Cbl binding protein. This Cbi blocking assay was found to function as well as the more conventional methods of IF measurement, G-100 column chromatography, and IF blocking antibody assay. The present assay has the advantage of eliminating the need for elaborate forms of protein separation and does not rely on a source of antibody

  10. Towards clinical development of a Pfs48/45-based transmission blocking malaria vaccine

    DEFF Research Database (Denmark)

    Theisen, Michael; Jore, Matthijs M; Sauerwein, Robert

    2017-01-01

    Introduction: Malaria is a devastating vector-borne disease caused by the Plasmodium parasite, resulting in almost 0.5 million casualties per year. The parasite has a complex life-cycle that includes asexual replication in human red blood cells, causing symptomatic malaria, and sexual stages which...... are essential for the transmission to the mosquito vector. A vaccine targeting the sexual stages of the parasite and thus blocking transmission will be instrumental for the eradication of malaria. One of the leading transmission blocking vaccine candidates is the sexual stage antigen Pfs48/45. Areas covered......: PubMed was searched to review the progress and future prospects for clinical development of a Pfs48/45-based subunit vaccine. We will focus on biological function, naturally acquired immunity, functional activity of specific antibodies, sequence diversity, production of recombinant protein...

  11. Adaptability of the Logistics System in National Economic Mobilization Based on Blocking Flow Theory

    Directory of Open Access Journals (Sweden)

    Xiangyuan Jing

    2014-01-01

    Full Text Available In the process of national economic mobilization, the logistics system usually suffers from negative impact and/or threats of such emergency events as wars and accidents, which implies that adaptability of the logistics system directly determines realization of economic mobilization. And where the real-time rescue operation is concerned, heavy traffic congestion is likely to cause a great loss of or damage to human beings and their properties. To deal with this situation, this article constructs a blocking-resistance optimum model and an optimum restructuring model based on blocking flow theories, of which both are illustrated by numerical cases and compared in characteristics and application. The design of these two models is expected to eliminate or alleviate the congestion situation occurring in the logistics system, thus effectively enhancing its adaptability in the national economic mobilization process.

  12. A novel image block cryptosystem based on a spatiotemporal chaotic system and a chaotic neural network

    International Nuclear Information System (INIS)

    Wang Xing-Yuan; Bao Xue-Mei

    2013-01-01

    In this paper, we propose a novel block cryptographic scheme based on a spatiotemporal chaotic system and a chaotic neural network (CNN). The employed CNN comprises a 4-neuron layer called a chaotic neuron layer (CNL), where the spatiotemporal chaotic system participates in generating its weight matrix and other parameters. The spatiotemporal chaotic system used in our scheme is the typical coupled map lattice (CML), which can be easily implemented in parallel by hardware. A 160-bit-long binary sequence is used to generate the initial conditions of the CML. The decryption process is symmetric relative to the encryption process. Theoretical analysis and experimental results prove that the block cryptosystem is secure and practical, and suitable for image encryption. (general)

  13. Use of shock block transmitters in the structural rehabilitation of historical buildings in Calabria and Sicily

    International Nuclear Information System (INIS)

    Bianco, Alessia; Candela, Michele; Fonti, Roberta

    2008-01-01

    Many old and historical masonry buildings, located in the Calabrian and Sicilian areas near the strait of Messina, are affected by typical pattern of cracks, which are not produced by previous earthquakes. These cracks in the masonry walls are characterized by a quasi-vertical trend with constant width. The careful examination of the crack distribution allows to clearly identify the diagnosis: the damage is caused by the sinking due to a horizontal movement of translation of the ground, which is an evident effect of creep phenomena in the soil, so-called 'solifluxion'. This paper, after showing this geological pathology, proposes an innovative strategy of intervention, which consists of the use of 'oleo-dynamic' devices, so-called shock block transmitters, providing different degrees of restraint, according to the loading conditions. In addition, in case of earthquake, an important part of the in-put seismic energy can be dissipated. The strategy of application of this system to the building consists of the subdivision of each masonry wall in two different parts, which are physically separated by the cracks. Each wall portion must be consolidated separately and the different parts of walls behave as statically independent each other, so that they can move independently during the serviceability conditions. The connection among the walls composing the whole structural organism is given by metal tie-rods equipped with 'oleo dynamic' devices, which allows, in a given range, the horizontal sliding in case of slow movement due to the phenomenon of 'solifluxion'. Contrary, in case of dynamic and fast movements, such as the ones produced by an earthquake, each 'oleo dynamic' device provides a fully restraint effect and, as a consequence, the tie-rods behave in the classical way

  14. Structural influence of graft and block polycations on the adsorption of BSA.

    Science.gov (United States)

    Zhang, Li; Jin, Fengmin; Zhang, Tingbin; Zhang, Ling; Xing, Jinfeng

    2016-04-01

    Protein adsorption is considered as an important factor for the low transfection efficiency of polycations in vivo. In this study, two typical polycations of equal molecular weight with different structures were chosen to investigate their adsorption on bovine serum albumin (BSA), including the block copolymer named poly (N-vinylpyrrolidone)-b-poly (2-dimethylaminoethyl methacrylate) (PVP-b-PDMAEMA, i.e. PbP) and graft copolymer named PVP-g-PDMAEMA (PgP), respectively. Fluorescence spectroscopy was used to confirm the binding constants and binding sites between polycations and BSA in static state. The binding constants were 4.1×10(4)M(-1) vs 8.3×10(4)M(-1) and binding sites were 0.3 vs 1.1 for PbP and PgP, respectively, indicating PgP had stronger binding affinity with BSA. Surface plasmon resonance (SPR) was used to study the dynamical non-specific interaction between BSA and polycations as well as the polyplexes. The numbers of both PbP and PgP adsorbed on BSA increased with concentration of polycations increasing, and the number of PgP adsorbed on BSA is higher compared with PbP when their concentration is low. When their concentration is high, the number of PbP adsorbed on BSA is more than that of PgP. However, PgP/DNA polyplexes showed higher adsorption amount compared with PbP/DNA polyplexes at different N/P ratios. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. Improving Performance via Blocking Layers in Dye-Sensitized Solar Cells Based on Nanowire Photoanodes.

    Science.gov (United States)

    Li, Luping; Xu, Cheng; Zhao, Yang; Chen, Shikai; Ziegler, Kirk J

    2015-06-17

    Electron recombination in dye-sensitized solar cells (DSSCs) results in significant electron loss and performance degradation. However, the reduction of electron recombination via blocking layers in nanowire-based DSSCs has rarely been investigated. In this study, HfO2 or TiO2 blocking layers are deposited on nanowire surfaces via atomic layer deposition (ALD) to reduce electron recombination in nanowire-based DSSCs. The control cell consisting of ITO nanowires coated with a porous shell of TiO2 by TiCl4 treatment yields an efficiency of 2.82%. The efficiency increases dramatically to 5.38% upon the insertion of a 1.3 nm TiO2 compact layer between the nanowire surface and porous TiO2 shell. This efficiency enhancement implies that porous sol-gel coatings on nanowires (e.g., via TiCl4 treatment) result in significant electron recombination in nanowire-based DSSCs, while compact coatings formed by ALD are more advantageous because of their ability to act as a blocking layer. By comparing nanowire-based DSSCs with their nanoparticle-based counterparts, we find that the nanowire-based DSSCs suffer more severe electron recombination from ITO due to the much higher surface area exposed to the electrolyte. While the insertion of a high band gap compact layer of HfO2 between the interface of the conductive nanowire and TiO2 shell improves performance, a comparison of the cell performance between TiO2 and HfO2 compact layers indicates that charge collection is suppressed by the difference in energy states. Consequently, the use of high band gap materials at the interface of conductive nanowires and TiO2 is not recommended.

  16. A Concise Synthesis of Glycolipids Based on Aspartic Acid Building Blocks

    Directory of Open Access Journals (Sweden)

    Lorna Abbey

    2012-09-01

    Full Text Available L-Aspartic acid building blocks bearing galactosyl moieties were used to synthesise glycolipid mimetics of variable hydrocarbon chain length. The glycolipids were readily prepared through amide bond formation using the TBTU/HOBt coupling methodology. It was observed that, under these conditions, activation of the α-carboxylic acid of the intermediates led to near complete racemisation of the chiral centre if the reaction was carried out in the presence of a base such as triethylamine. The enantiomerically pure glycolipids were obtained after careful consideration of the synthetic sequence and by performing the coupling reactions in the absence of base.

  17. Plasma-based accelerator structures

    International Nuclear Information System (INIS)

    Schroeder, Carl B.

    1999-01-01

    Plasma-based accelerators have the ability to sustain extremely large accelerating gradients, with possible high-energy physics applications. This dissertation further develops the theory of plasma-based accelerators by addressing three topics: the performance of a hollow plasma channel as an accelerating structure, the generation of ultrashort electron bunches, and the propagation of laser pulses is underdense plasmas

  18. The effect of block copolymer structure on the internalization of polymeric micelles by human breast cancer cells.

    Science.gov (United States)

    Mahmud, Abdullah; Lavasanifar, Afsaneh

    2005-10-10

    The objective of this study was to assess the effect of hydrophilic/hydrophobic block chain lengths on the internalization of poly(ethylene oxide)-block-poly(epsilon-caprolactone) (PEO-b-PCL) micelles by cancer cells. PEO-b-PCL block copolymers with varied PEO and PCL chain lengths were synthesized, assembled to polymeric micelles and loaded with a hydrophobic fluorescent probe (DiI) through a co-solvent evaporation method of physical encapsulation. The slow release of the fluorescent probe from the micellar structure was evidenced following DiI transfer to lipid vesicles. The extent of micellar uptake by cancer cells was investigated through their incubation with MCF-7 cells followed by measurement of the fluorescent emission intensity of DiI (lambda=550 nm) in separated lysed cells. Cellular internalization of polymeric micelles was confirmed by laser scanning microscopy. The mechanism of micellar uptake was investigated by pretreatment of MCF-7 cells with chlorpromazine and cytochalasin B. Encapsulation of DiI in PEO-b-PCL micelles lowered the extent and rate of hydrophobic probe internalization by cancer cells. For polymeric micelles with 5000 gmol(-1) of PCL and varied PEO molecular weights of 2000, 5000 and 13,000 gmol(-1), maximum uptake was observed at a PEO molecular weight of 5000 gmol(-1). For polymeric micelles with 5000 gmol(-1) of PEO and varied PCL molecular weights of 5000, 13,000 and 24,000 gmol(-1), maximum uptake was observed at 13,000 gmol(-1) of PCL. Chlorpromazine reduced the cellular uptake of PEO-b-PCL micelles independent from the block copolymer structure, pointing to the involvement of clathrin mediated endocytosis mechanisms in the uptake of polymeric micelles by cancer cells. Inhibition of cellular uptake of PEO-b-PCL micelles by cytochalasin B, on the other hand, was found to be dependent on the chemical structure of the core/shell forming blocks.

  19. Study on the Damping of the Discontinuous Deformation Analysis Based on Two-Block Model

    Directory of Open Access Journals (Sweden)

    Xixia Feng

    2017-01-01

    Full Text Available The deformation and failure of rock mass is a process of energy dissipation; the damping of DDA is a very important and basic problem. The correctness and effectiveness of DDA rely on the appropriate values of the numeric controlling parameters like time interval, spring stiffness, and assumed maximum displacement ratio g2, and the contact using the penalty method is the core content of DDA. A mechanical model of two contact blocks loaded with the normal force acting along one side of block boundary is established to study the DDA damping problem, which involves the contact and eliminates the influence of some numeric control parameters (e.g., g2. Based on the Newmark method and the theory of DDA, the motion equations of two-block system can be established, and then the relationship of some numeric control parameters and the influence of damping can be obtained. The algorithmic damping increases with the increasing of time interval. Given a very small time interval, the spring stiffness may have no obvious effect on the algorithmic damping. The numerical results reveal that the essence of time interval influencing the open-close iteration is the fact that the algorithmic damping is mainly controlled by time interval.

  20. Energy decomposition analysis based on a block-localized wavefunction and multistate density functional theory.

    Science.gov (United States)

    Mo, Yirong; Bao, Peng; Gao, Jiali

    2011-04-21

    An interaction energy decomposition analysis method based on the block-localized wavefunction (BLW-ED) approach is described. The first main feature of the BLW-ED method is that it combines concepts of valence bond and molecular orbital theories such that the intermediate and physically intuitive electron-localized states are variationally optimized by self-consistent field calculations. Furthermore, the block-localization scheme can be used both in wave function theory and in density functional theory, providing a useful tool to gain insights on intermolecular interactions that would otherwise be difficult to obtain using the delocalized Kohn-Sham DFT. These features allow broad applications of the BLW method to energy decomposition (BLW-ED) analysis for intermolecular interactions. In this perspective, we outline theoretical aspects of the BLW-ED method, and illustrate its applications in hydrogen-bonding and π-cation intermolecular interactions as well as metal-carbonyl complexes. Future prospects on the development of a multistate density functional theory (MSDFT) are presented, making use of block-localized electronic states as the basis configurations.

  1. Towards clinical development of a Pfs48/45-based transmission blocking malaria vaccine.

    Science.gov (United States)

    Theisen, Michael; Jore, Matthijs M; Sauerwein, Robert

    2017-04-01

    Malaria is a devastating vector-borne disease caused by the Plasmodium parasite, resulting in almost 0.5 million casualties per year. The parasite has a complex life-cycle that includes asexual replication in human red blood cells, causing symptomatic malaria, and sexual stages which are essential for the transmission to the mosquito vector. A vaccine targeting the sexual stages of the parasite and thus blocking transmission will be instrumental for the eradication of malaria. One of the leading transmission blocking vaccine candidates is the sexual stage antigen Pfs48/45. Areas covered: PubMed was searched to review the progress and future prospects for clinical development of a Pfs48/45-based subunit vaccine. We will focus on biological function, naturally acquired immunity, functional activity of specific antibodies, sequence diversity, production of recombinant protein and preclinical studies. Expert commentary: Pfs48/45 is one of the lead-candidates for a transmission blocking vaccine and should be further explored in clinical trials.

  2. Block adjustment of airborne InSAR based on interferogram phase and POS data

    Science.gov (United States)

    Yue, Xijuan; Zhao, Yinghui; Han, Chunming; Dou, Changyong

    2015-12-01

    High-precision surface elevation information in large scale can be obtained efficiently by airborne Interferomatric Synthetic Aperture Radar (InSAR) system, which is recently becoming an important tool to acquire remote sensing data and perform mapping applications in the area where surveying and mapping is difficult to be accomplished by spaceborne satellite or field working. . Based on the study of the three-dimensional (3D) positioning model using interferogram phase and Position and Orientation System (POS) data and block adjustment error model, a block adjustment method to produce seamless wide-area mosaic product generated from airborne InSAR data is proposed in this paper. The effect of 6 parameters, including trajectory and attitude of the aircraft, baseline length and incline angle, slant range, and interferometric phase, on the 3D positioning accuracy is quantitatively analyzed. Using the data acquired in the field campaign conducted in Mianyang county Sichuan province, China in June 2011, a mosaic seamless Digital Elevation Model (DEM) product was generated from 76 images in 4 flight strips by the proposed block adjustment model. The residuals of ground control points (GCPs), the absolute positioning accuracy of check points (CPs) and the relative positioning accuracy of tie points (TPs) both in same and adjacent strips were assessed. The experimental results suggest that the DEM and Digital Orthophoto Map (DOM) product generated by the airborne InSAR data with sparse GCPs can meet mapping accuracy requirement at scale of 1:10 000.

  3. Energy decomposition analysis based on a block-localized wavefunction and multistate density functional theory

    Science.gov (United States)

    Bao, Peng

    2013-01-01

    An interaction energy decomposition analysis method based on the block-localized wavefunction (BLW-ED) approach is described. The first main feature of the BLW-ED method is that it combines concepts of valence bond and molecular orbital theories such that the intermediate and physically intuitive electron-localized states are variationally optimized by self-consistent field calculations. Furthermore, the block-localization scheme can be used both in wave function theory and in density functional theory, providing a useful tool to gain insights on intermolecular interactions that would otherwise be difficult to obtain using the delocalized Kohn–Sham DFT. These features allow broad applications of the BLW method to energy decomposition (BLW-ED) analysis for intermolecular interactions. In this perspective, we outline theoretical aspects of the BLW-ED method, and illustrate its applications in hydrogen-bonding and π–cation intermolecular interactions as well as metal–carbonyl complexes. Future prospects on the development of a multistate density functional theory (MSDFT) are presented, making use of block-localized electronic states as the basis configurations. PMID:21369567

  4. Lamellar Microdomains of Block-Copolymer-Based Ionic Supramolecules Exhibiting a Hierarchical Self-Assembly

    DEFF Research Database (Denmark)

    Ayoubi, Mehran Asad; Almdal, Kristoffer; Zhu, Kaizheng

    2014-01-01

    (Cn; n = 8, 12, and 16) trimethylammonium counterions (i.e., side chains) at various ion (pair) fractions X [i.e., counterion/side-chain grafting density; X = number of alkyl counterions (i.e., side chains) per acidic group of the parent PMAA block] these L-b-AC ionic supramolecules exhibit...... a spherical-in-lamellar hierarchical self-assembly. For these systems, (1) the effective Flory-Huggins interaction parameter between L- and AC-blocks chi'(Cn/x) was extracted, and (2) analysis of the lamellar microdomains showed that when there is an increase in X, alkyl counterion (i.e., side chain) length l......Based on a parent diblock copolymer of poly(styrene)-b-poly(methacrylic acid), PS-b-PMAA, linear-b-amphiphilic comb (L-b-AC) ionic supramolecules [Soft Matter 2013, 9, 1540-1555] are synthesized in which the poly(methacrylate) backbone of the ionic supramolecular AC-block is neutralized by alkyl...

  5. Is the idea of a fast block to polyspermy based on artifact?

    Science.gov (United States)

    Dale, Brian

    2014-08-01

    This purpose of this review is to look at the experimental evidence, both kinetic and electrophysiological, that led to the hypothesis of a fast electrical block to polyspermy in sea urchin eggs. The idea of a fast partial block, forwarded in the 1950's, that would reduce the receptivity of the egg surface by 1/20th following its interaction with the fertilizing spermatozoon, was based on experiments that treated fertilization as a first order chemical reaction. Here, I outline the criticisms of the Rothschild theory and demonstrate that the hypothesis of a fast partial block to polyspermy is unfounded. Notwithstanding, it was suggested in the 1970's that the membrane depolarization, induced by the fertilizing spermatozoon, prevented the interaction of supernumerary spermatozoa, the fast electrical block to polyspermy. While trans-membrane voltage recording has permitted a better understanding of the sequence of events occurring at fertilization, there is no evidence that depolarization prevents the interaction of supernumerary spermatozoa. Sperm entry is prevented at positive and negative potentials, in the voltage clamp configuration, however this is an artifact caused by the currents injected into the egg employed to hold the voltage constant in a non-physiological range. At permissive voltages, around -20 mV, where the current required to hold the voltage is minimal, only one spermatozoon normally enters the egg. Thus, irrespective of the egg voltage, the fertilizing spermatozoon is, in any case, attached to a privileged interaction site that permits entry and distinguishes it from supernumerary spermatozoa. Competence for monospermy is acquired during oocyte maturation and data on cortical organization in echinoderm eggs points to the actin filament system for regulating sperm entry. Copyright © 2014 Elsevier Inc. All rights reserved.

  6. Structural Analysis of Plate Based Tensegrity Structures

    DEFF Research Database (Denmark)

    Hald, Frederik; Kirkegaard, Poul Henning; Damkilde, Lars

    2013-01-01

    Plate tensegrity structures combine tension cables with a cross laminated timber plate and can then form e.g. a roof structure. The topology of plate tensegrity structures is investigated through a parametric investigation. Plate tensegrity structures are investigated, and a method...

  7. Efficient screening of fungal cellobiohydrolase class I enzymes for thermostabilizing sequence blocks by SCHEMA structure-guided recombination.

    Science.gov (United States)

    Heinzelman, Pete; Komor, Russell; Kanaan, Arvind; Romero, Philip; Yu, Xinlin; Mohler, Shannon; Snow, Christopher; Arnold, Frances

    2010-11-01

    We describe an efficient SCHEMA recombination-based approach for screening homologous enzymes to identify stabilizing amino acid sequence blocks. This approach has been used to generate active, thermostable cellobiohydrolase class I (CBH I) enzymes from the 390 625 possible chimeras that can be made by swapping eight blocks from five fungal homologs. Constructing and characterizing the parent enzymes and just 32 'monomeras' containing a single block from a homologous enzyme allowed stability contributions to be assigned to 36 of the 40 blocks from which the CBH I chimeras can be assembled. Sixteen of 16 predicted thermostable chimeras, with an average of 37 mutations relative to the closest parent, are more thermostable than the most stable parent CBH I, from the thermophilic fungus Talaromyces emersonii. Whereas none of the parent CBH Is were active >65°C, stable CBH I chimeras hydrolyzed solid cellulose at 70°C. In addition to providing a collection of diverse, thermostable CBH Is that can complement previously described stable CBH II chimeras (Heinzelman et al., Proc. Natl Acad. Sci. USA 2009;106:5610-5615) in formulating application-specific cellulase mixtures, the results show the utility of SCHEMA recombination for screening large swaths of natural enzyme sequence space for desirable amino acid blocks.

  8. The effect of heat treatment on the internal structure of nanostructured block copolymer films

    DEFF Research Database (Denmark)

    Sepe, Alessandro; Hoppe, E T; Jaksch, S

    2011-01-01

    We report on the temperature dependence of the nanostructure of thin block copolymer films, as studied using in situ grazing-incidence small-angle x-ray scattering (GISAXS). We focus on spin-coated poly(styrene-b-butadiene) diblock copolymer thin films featuring lamellae perpendicular to the subs......We report on the temperature dependence of the nanostructure of thin block copolymer films, as studied using in situ grazing-incidence small-angle x-ray scattering (GISAXS). We focus on spin-coated poly(styrene-b-butadiene) diblock copolymer thin films featuring lamellae perpendicular...

  9. Clinical postconference pedagogy: exploring evidence-based practice with millennial-inspired "Building Blocks".

    Science.gov (United States)

    Schams, Kristin A; Kuennen, Jackie K

    2012-01-01

    This article reports an innovative teaching strategy consisting of learning units whereby students come to postconference sessions prepared to share evidence-based practice (EBP) information associated with upcoming laboratory concepts, discover relationships among laboratory concepts and current nursing practice, and associate personal clinical experiences with the practice environment. This strategy, named "Building Blocks," represents one method to transform nursing education into a more active process, and also has the potential to prepare graduates who can function in a dynamic health care environment incorporating EBP.

  10. Micro- and nanophase separations in hierarchical self-assembly of strongly amphiphilic block copolymer-based ionic supramolecules

    DEFF Research Database (Denmark)

    Ayoubi, Mehran Asad; Zhu, Kaizheng; Nyström, Bo

    2013-01-01

    By a selective complexation between different alkyltrimethylammonium amphiphiles (C8, C12 and C16) and three different diblock copolymer systems of poly(styrene)-b-poly(methacrylic acid) at various grafting densities X (X = number of alkyl chains per acidic group of the poly(methacrylic acid) PMAA...... block), a class of ionic supramolecules are successfully synthesized whose molecular architecture consists of a poly(styrene) PS block (Linear block) covalently connected to a strongly amphiphilic comb-like block (AmphComb block), i.e. Linear-b-AmphComb. In the melt state, these ionic supramolecules can...... show simultaneous microphase (between Linear and AmphComb blocks) and nanophase (within the AmphComb blocks) separations. This leads to the formation of various structure-in-structure two-scale hierarchical self-assemblies, including S-in-SLL, S-in-SBCC, S-in-C, S-in-L and C-in-L, where S, SLL, SBCC, C...

  11. A Review on Block Matching Motion Estimation and Automata Theory based Approaches for Fractal Coding

    Directory of Open Access Journals (Sweden)

    Shailesh Kamble

    2016-12-01

    Full Text Available Fractal compression is the lossy compression technique in the field of gray/color image and video compression. It gives high compression ratio, better image quality with fast decoding time but improvement in encoding time is a challenge. This review paper/article presents the analysis of most significant existing approaches in the field of fractal based gray/color images and video compression, different block matching motion estimation approaches for finding out the motion vectors in a frame based on inter-frame coding and intra-frame coding i.e. individual frame coding and automata theory based coding approaches to represent an image/sequence of images. Though different review papers exist related to fractal coding, this paper is different in many sense. One can develop the new shape pattern for motion estimation and modify the existing block matching motion estimation with automata coding to explore the fractal compression technique with specific focus on reducing the encoding time and achieving better image/video reconstruction quality. This paper is useful for the beginners in the domain of video compression.

  12. Enhanced thermoelectric properties in bulk nanowire heterostructure-based nanocomposites through minority carrier blocking.

    Science.gov (United States)

    Yang, Haoran; Bahk, Je-Hyeong; Day, Tristan; Mohammed, Amr M S; Snyder, G Jeffrey; Shakouri, Ali; Wu, Yue

    2015-02-11

    To design superior thermoelectric materials the minority carrier blocking effect in which the unwanted bipolar transport is prevented by the interfacial energy barriers in the heterogeneous nanostructures has been theoretically proposed recently. The theory predicts an enhanced power factor and a reduced bipolar thermal conductivity for materials with a relatively low doping level, which could lead to an improvement in the thermoelectric figure of merit (ZT). Here we show the first experimental demonstration of the minority carrier blocking in lead telluride-silver telluride (PbTe-Ag2Te) nanowire heterostructure-based nanocomposites. The nanocomposites are made by sintering PbTe-Ag2Te nanowire heterostructures produced in a highly scalable solution-phase synthesis. Compared with Ag2Te nanowire-based nanocomposite produced in similar method, the PbTe-Ag2Te nanocomposite containing ∼5 atomic % PbTe exhibits enhanced Seebeck coefficient, reduced thermal conductivity, and ∼40% improved ZT, which can be well explained by the theoretical modeling based on the Boltzmann transport equations when energy barriers for both electrons and holes at the heterostructure interfaces are considered in the calculations. For this p-type PbTe-Ag2Te nanocomposite, the barriers for electrons, that is, minority carriers, are primarily responsible for the ZT enhancement. By extending this approach to other nanostructured systems, it represents a key step toward low-cost solution-processable nanomaterials without heavy doping level for high-performance thermoelectric energy harvesting.

  13. Design for an IO block array in a tile-based FPGA

    International Nuclear Information System (INIS)

    Ding Guangxin; Chen Lingdou; Liu Zhongli

    2009-01-01

    A design for an IO block array in a tile-based FPGA is presented. Corresponding with the characteristics of the FPGA, each IO cell is composed of a signal path, local routing pool and configurable input/output buffers. Shared programmable registers in the signal path can be configured for the function of JTAG, without specific boundary scan registers/latches, saving layout area. The local routing pool increases the flexibility of routing and the routability of the whole FPGA. An auxiliary power supply is adopted to increase the performance of the IO buffers at different configured IO standards. The organization of the IO block array is described in an architecture description file, from which the array layout can be accomplished through use of an automated layout assembly tool. This design strategy facilitates the design of FPGAs with different capacities or architectures in an FPGA family series. The bond-out schemes of the same FPGA chip in different packages are also considered. The layout is based on SMIC 0.13 μm logic 1P8M salicide 1.2/2.5 V CMOS technology. Our performance is comparable with commercial SRAM-based FPGAs which use a similar process. (semiconductor integrated circuits)

  14. The structure of P85 pluronic block copolymer micelles determined by small-angle neutron scattering

    DEFF Research Database (Denmark)

    Pedersen, J.S.; Gerstenberg, M.C.

    2003-01-01

    a spherical core of poly(propylene oxide) (PPO) with some water surrounded by a corona of the poly(ethylene oxide) (PEO) block. The latter are non-interacting and obey Gaussian statistics, but are expelled from the core region. The analysis shows that the micelles are fairly concentration and temperature...

  15. Phase structure of symmetric tri-block-copolymers and their blends

    Czech Academy of Sciences Publication Activity Database

    Baldrian, Josef; Steinhart, Miloš; Sikora, Antonín; Amenitsch, H.; Bernstorff, S.

    2005-01-01

    Roč. 13, č. 5 (2005), s. 35-40 ISSN 1230-3666 R&D Projects: GA ČR GA203/03/0611 Institutional research plan: CEZ:AV0Z40500505 Keywords : crystallization * block copolymers * blends Subject RIV: CD - Macromolecular Chemistry Impact factor: 0.397, year: 2005

  16. Self-assembly of POSS-containing block copolymers: fixing the hierarchical structure in networks

    Czech Academy of Sciences Publication Activity Database

    Matějka, Libor; Janata, Miroslav; Pleštil, Josef; Zhigunov, Alexander; Šlouf, Miroslav

    2014-01-01

    Roč. 55, č. 1 (2014), s. 126-136 ISSN 0032-3861 R&D Projects: GA ČR GAP108/12/1459 Grant - others:AV ČR(CZ) M200500903 Institutional support: RVO:61389013 Keywords : block copolymers * self-assembly * POSS Subject RIV: CD - Macromolecular Chemistry Impact factor: 3.562, year: 2014

  17. On the Grammar of Silence: The Structure of My Undocumented Immigrant Writer's Block

    Science.gov (United States)

    Ledesma, Alberto

    2015-01-01

    In this reflective essay, Alberto Ledesma explores how being undocumented can produce a particular form of writer's block. He argues that there is a pattern of predictable silences and obfuscations inherent in all undocumented immigrant autobiographies that cannot be easily negotiated when undocumented students are asked to write about "their…

  18. Phase-based block matching applied to motion estimation with unconventional beamforming strategies.

    Science.gov (United States)

    Basarab, Adrian; Gueth, Pierre; Liebgott, Hervé; Delachartre, Philippe

    2009-05-01

    A phase-based block matching method adapted to motion estimation with unconventional beamforming strategies is presented. The unconventional beamforming technique used allows us to obtain 2-D RF images with axial and lateral modulations. Based on these images, we propose a method that uses phase images instead of amplitude images. This way of proceeding allows us to provide an analytical solution to the local displacement estimation so that no minimization of a classical cost function is used for the local estimation. For this reason, the local estimator is directly applied to signals, without the need to process a complex cross-correlation function, as is done with most of the phase shift estimators. In this paper, the method is applied to elastography. Results with simulated data show that a downsampling of axial and lateral modulated signals leads to very little change in the accuracy and in the spatial resolution of the proposed method. For example, for decimation factors of 2 in the axial direction and of 4 in the lateral direction, the mean axial absolute error is 3 mum. The same estimation with original images provides a mean axial error of 0.7 microm. The accuracy of the lateral motion is unchanged in this case. The accuracy of our method with downsampled signals is an important issue in the purpose of a real-time implementation. With experimental data, for the same level of estimation error, classical block matching using the maximum of cross correlation as a local estimator requires images that are 36 times larger (in number of pixels) and consequently a computational time roughly 10 times longer. Our phase block matching is also shown to provide 10 percent less error than a motion estimation method based on seeking the zero of the complex correlation function phase. Finally, it is shown that given the separability of the local estimator that we propose, our method can be applied on both n-D signals and classical RF ultrasound images. The phase block

  19. Stratigraphy of amethyst geode-bearing lavas and fault-block structures of the Entre Rios mining district, Paraná volcanic province, southern Brazil

    Directory of Open Access Journals (Sweden)

    LÉO A. HARTMANN

    2014-03-01

    Full Text Available The Entre Rios mining district produces a large volume of amethyst geodes in underground mines and is part of the world class deposits in the Paraná volcanic province of South America. Two producing basalt flows are numbered 4 and 5 in the lava stratigraphy. A total of seven basalt flows and one rhyodacite flow are present in the district. At the base of the stratigraphy, beginning at the Chapecó river bed, two basalt flows are Esmeralda, low-Ti type. The third flow in the sequence is a rhyodacite, Chapecó type, Guarapuava subtype. Above the rhyodacite flow, four basalt flows are Pitanga, high-Ti type including the two mineralized flows; only the topmost basalt in the stratigraphy is a Paranapanema, intermediate-Ti type. Each individual flow is uniquely identified from its geochemical and gamma-spectrometric properties. The study of several sections in the district allowed for the identification of a fault-block structure. Blocks are elongated NW and the block on the west side of the fault was downthrown. This important structural characterization of the mining district will have significant consequences in the search for new amethyst geode deposits and in the understanding of the evolution of the Paraná volcanic province.

  20. Studies and mechanical properties of a new type of 'hybrid' ceramic block for buildings in structural masonry

    International Nuclear Information System (INIS)

    Camara, Cassio Freire; Gomes, Uilame Umbelino

    2012-01-01

    This paper presents the development of a hybrid ceramic block to the use of resides in the buildings executed with structural masonry. This work seeking new materials and / or products with the purpose of increasing the compressive strength of the ceramic blocks, without neglecting other properties (water absorption and linear shrinkage). After the obtained material (clay powder and crushed), the packaging (in percentages ranging from 0%, 5%, 10% and 15% substitution of crushed clay powder), the identification and measuring (weights and lengths) of the bodies of the test piece, was performed on the approach characterized by fluorescence, mineralogy and SEM of these materials as well as the characterization (SEM) of ceramic blocks after the sintering (temperature of the 900 deg C, 1000 deg C, and 1100 deg C rate with heating tax of 5 o C/minute and soak for 1 hour). Then the samples were subjected to the tests (compressive strength and water absorption) and the respective calculated linear shrinkage. After conducting the analysis of the results of these tests (according to the criteria and parameters required by the ABNT NBR 15270) was found that the 'hybrid' block with the addition of 10% crushed powder obtained the best results, increasing the compressive strength at 16 % without compromising the other parameters required by the Standard. (author)

  1. X-Ray Structures of the Hexameric Building Block of the HIV Capsid

    Energy Technology Data Exchange (ETDEWEB)

    Pornillos, Owen; Ganser-Pornillos, Barbie K.; Kelly, Brian N.; Hua, Yuanzi; Whitby, Frank G.; Stout, C. David; Sundquist, Wesley I.; Hill, Christopher P.; Yeager, Mark; (Scripps); (Utah)

    2009-09-11

    The mature capsids of HIV and other retroviruses organize and package the viral genome and its associated enzymes for delivery into host cells. The HIV capsid is a fullerene cone: a variably curved, closed shell composed of approximately 250 hexamers and exactly 12 pentamers of the viral CA protein. We devised methods for isolating soluble, assembly-competent CA hexamers and derived four crystallographically independent models that define the structure of this capsid assembly unit at atomic resolution. A ring of six CA N-terminal domains form an apparently rigid core, surrounded by an outer ring of C-terminal domains. Mobility of the outer ring appears to be an underlying mechanism for generating the variably curved lattice in authentic capsids. Hexamer-stabilizing interfaces are highly hydrated, and this property may be key to the formation of quasi-equivalent interactions within hexamers and pentamers. The structures also clarify the molecular basis for capsid assembly inhibition and should facilitate structure-based drug design strategies.

  2. Self-assembling peptide-based building blocks in medical applications

    Energy Technology Data Exchange (ETDEWEB)

    Acar, Handan; Srivastava, Samanvaya; Chung, Eun Ji; Schnorenberg, Mathew R.; Barrett, John C.; LaBelle, James L.; Tirrell, Matthew

    2017-02-01

    Peptides and peptide-conjugates, comprising natural and synthetic building blocks, are an increasingly popular class of biomaterials. Self-assembled nanostructures based on peptides and peptide-conjugates offer advantages such as precise selectivity and multifunctionality that can address challenges and limitations in the clinic. In this review article, we discuss recent developments in the design and self-assembly of various nanomaterials based on peptides and peptide-conjugates for medical applications, and categorize them into two themes based on the driving forces of molecular self-assembly. First, we present the self-assembled nanostructures driven by the supramolecular interactions between the peptides, with or without the presence of conjugates. The studies where nanoassembly is driven by the interactions between the conjugates of peptide-conjugates are then presented. Particular emphasis is given to in vivo studies focusing on therapeutics, diagnostics, immune modulation and regenerative medicine. Finally, challenges and future perspectives are presented.

  3. Photochemical selectivity in guanine–cytosine base-pair structures

    Science.gov (United States)

    Abo-Riziq, Ali; Grace, Louis; Nir, Eyal; Kabelac, Martin; Hobza, Pavel; de Vries, Mattanjah S.

    2005-01-01

    Prebiotic chemistry presumably took place before formation of an oxygen-rich atmosphere and thus under conditions of intense short wavelength UV irradiation. Therefore, the UV photochemical stability of the molecular building blocks of life may have been an important selective factor in determining the eventual chemical makeup of critical biomolecules. To investigate the role of UV irradiation in base-pairing we have studied guanine (G) and cytosine (C) base pairs in the absence of the RNA backbone. We distinguished base-pair structures by IR–UV hole-burning spectroscopy as well as by high-level correlated ab initio calculations. The Watson–Crick structure exhibits broad UV absorption, in stark contrast to other GC structures and other base-pair structures. This broad absorption may be explained by a rapid internal conversion that makes this specific base pair arrangement uniquely photochemically stable. PMID:15618394

  4. First-Principles Prediction of New Electrides with Nontrivial Band Topology Based on One-Dimensional Building Blocks

    Science.gov (United States)

    Park, Changwon; Kim, Sung Wng; Yoon, Mina

    2018-01-01

    We introduce a new class of electrides with nontrivial band topology by coupling materials database searches and first-principles-calculations-based analysis. Cs3O and Ba3N are for the first time identified as a new class of electrides, consisting of one-dimensional (1D) nanorod building blocks. Their crystal structures mimic β -TiCl3 with the position of anions and cations exchanged. Unlike the weakly coupled nanorods of β -TiCl3 , Cs3O and Ba3N retain 1D anionic electrons along the hollow interrod sites; additionally, a strong interrod interaction in C3O and Ba3N induces band inversion in a 2D superatomic triangular lattice, resulting in Dirac-node lines. The new class of electrides can serve as a prototype for new electrides with a large cavity space that can be utilized for various applications such as gas storage, ion transport, and metal intercalation.

  5. A novel block encryption scheme based on chaos and an S-box for wireless sensor networks

    International Nuclear Information System (INIS)

    Tong Xiao-Jun; Zuo Ke; Wang Zhu

    2012-01-01

    The wireless sensor network (WSN) has been widely used in various fields, but it still remains in the preliminary discovery and research phase with a lack of various related mature technologies. Traditional encryption schemes are not suitable for wireless sensor networks due to intrinsic features of the nodes such as low energy, limited computation capability, and lack of storage resources. In this paper, we present a novel block encryption scheme based on the integer discretization of a chaotic map, the Feistel network structure, and an S-box. The novel scheme is fast, secure, has low resource consumption and is suitable for wireless sensor network node encryption schemes. The experimental tests are carried out with detailed analysis, showing that the novel block algorithm has a large key space, very good diffusion and disruptive performances, a strict avalanche effect, excellent statistical balance, and fast encryption speed. These features enable the encryption scheme to pass the SP800-22 test. Meanwhile, the analysis and the testing of speed, time, and storage space on the simulator platform show that this new encryption scheme is well able to hide data information in wireless sensor networks. (general)

  6. Tendon-motion tracking in an ultrasound image sequence using optical-flow-based block matching.

    Science.gov (United States)

    Chuang, Bo-I; Hsu, Jian-Han; Kuo, Li-Chieh; Jou, I-Ming; Su, Fong-Chin; Sun, Yung-Nien

    2017-04-20

    Tendon motion, which is commonly observed using ultrasound imaging, is one of the most important features used in tendinopathy diagnosis. However, speckle noise and out-of-plane issues make the tracking process difficult. Manual tracking is usually time consuming and often yields inconsistent results between users. To automatically track tendon motion in ultrasound images, we developed a new method that combines the advantages of optical flow and multi-kernel block matching. For every pair of adjacent image frames, the optical flow is computed and used to estimate the accumulated displacement. The proposed method selects the frame interval adaptively based on this displacement. Multi-kernel block matching is then computed on the two selected frames, and, to reduce tracking errors, the detailed displacements of the frames in between are interpolated based on the optical flow results. In the experiments, cadaver data were used to evaluate the tracking results. The mean absolute error was less than 0.05 mm. The proposed method also tracked the motion of tendons in vivo, which provides useful information for clinical diagnosis. The proposed method provides a new index for adaptively determining the frame interval. Compared with other methods, the proposed method yields tracking results that are significantly more accurate.

  7. A spectral CT denoising algorithm based on weighted block matching 3D filtering

    Science.gov (United States)

    Salehjahromi, Morteza; Zhang, Yanbo; Yu, Hengyong

    2017-09-01

    In spectral CT, an energy-resolving detector is capable of counting the number of received photons in different energy channels with appropriate post-processing steps. Because the received photon number in each energy channel is low in practice, the generated projections suffer from low signal-to-noise ratio. This poses a challenge to perform image reconstruction of spectral CT. Because the reconstructed multi-channel images are for the same object but in different energies, there is a high correlation among these images and one can make full use of this redundant information. In this work, we propose a weighted block-matching and three-dimensional (3-D) filtering (BM3D) based method for spectral CT denoising. It is based on denoising of small 3-D data arrays formed by grouping similar 2-D blocks from the whole 3-D data image. This method consists of the following two steps. First, a 2-D image is obtained using the filtered back-projection (FBP) in each energy channel. Second, the proposed weighted BM3D filtering is performed. It not only uses the spatial correlation within each channel image but also exploits the spectral correlation among the channel images. The proposed method is evaluated on both numerical simulation and realistic preclinical datasets, and its merits are demonstrated by the promising results.

  8. Medical image compression based on vector quantization with variable block sizes in wavelet domain.

    Science.gov (United States)

    Jiang, Huiyan; Ma, Zhiyuan; Hu, Yang; Yang, Benqiang; Zhang, Libo

    2012-01-01

    An optimized medical image compression algorithm based on wavelet transform and improved vector quantization is introduced. The goal of the proposed method is to maintain the diagnostic-related information of the medical image at a high compression ratio. Wavelet transformation was first applied to the image. For the lowest-frequency subband of wavelet coefficients, a lossless compression method was exploited; for each of the high-frequency subbands, an optimized vector quantization with variable block size was implemented. In the novel vector quantization method, local fractal dimension (LFD) was used to analyze the local complexity of each wavelet coefficients, subband. Then an optimal quadtree method was employed to partition each wavelet coefficients, subband into several sizes of subblocks. After that, a modified K-means approach which is based on energy function was used in the codebook training phase. At last, vector quantization coding was implemented in different types of sub-blocks. In order to verify the effectiveness of the proposed algorithm, JPEG, JPEG2000, and fractal coding approach were chosen as contrast algorithms. Experimental results show that the proposed method can improve the compression performance and can achieve a balance between the compression ratio and the image visual quality.

  9. Medical Image Compression Based on Vector Quantization with Variable Block Sizes in Wavelet Domain

    Directory of Open Access Journals (Sweden)

    Huiyan Jiang

    2012-01-01

    Full Text Available An optimized medical image compression algorithm based on wavelet transform and improved vector quantization is introduced. The goal of the proposed method is to maintain the diagnostic-related information of the medical image at a high compression ratio. Wavelet transformation was first applied to the image. For the lowest-frequency subband of wavelet coefficients, a lossless compression method was exploited; for each of the high-frequency subbands, an optimized vector quantization with variable block size was implemented. In the novel vector quantization method, local fractal dimension (LFD was used to analyze the local complexity of each wavelet coefficients, subband. Then an optimal quadtree method was employed to partition each wavelet coefficients, subband into several sizes of subblocks. After that, a modified K-means approach which is based on energy function was used in the codebook training phase. At last, vector quantization coding was implemented in different types of sub-blocks. In order to verify the effectiveness of the proposed algorithm, JPEG, JPEG2000, and fractal coding approach were chosen as contrast algorithms. Experimental results show that the proposed method can improve the compression performance and can achieve a balance between the compression ratio and the image visual quality.

  10. Secure Chaotic Map Based Block Cryptosystem with Application to Camera Sensor Networks

    Directory of Open Access Journals (Sweden)

    Muhammad Khurram Khan

    2011-01-01

    Full Text Available Recently, Wang et al. presented an efficient logistic map based block encryption system. The encryption system employs feedback ciphertext to achieve plaintext dependence of sub-keys. Unfortunately, we discovered that their scheme is unable to withstand key stream attack. To improve its security, this paper proposes a novel chaotic map based block cryptosystem. At the same time, a secure architecture for camera sensor network is constructed. The network comprises a set of inexpensive camera sensors to capture the images, a sink node equipped with sufficient computation and storage capabilities and a data processing server. The transmission security between the sink node and the server is gained by utilizing the improved cipher. Both theoretical analysis and simulation results indicate that the improved algorithm can overcome the flaws and maintain all the merits of the original cryptosystem. In addition, computational costs and efficiency of the proposed scheme are encouraging for the practical implementation in the real environment as well as camera sensor network.

  11. Conservation analysis of dengue virus T-cell epitope-based vaccine candidates using peptide block entropy

    Directory of Open Access Journals (Sweden)

    Lars Ronn Olsen

    2011-12-01

    Full Text Available Broad coverage of the pathogen population is particularly important when designing CD8+ T-cell epitope vaccines against viral pathogens. Traditional approaches to assembling broadly covering sets of peptides are commonly based on assembling highly conserved epitopes. Peptide block entropy analysis is a novel approach to assembling sets of broadly covering antigens. Since T-cell epitopes are recognized as peptides rather than individual residues, this method is based on calculating the information content of blocks of peptides from a multiple sequence alignment of homologous proteins rather than individual residues. The block entropy analysis provides broad coverage by variant inclusion, since high frequency may not be the sole determinant of the immunogenic potential of a predicted MHC class I binder. We applied block entropy analysis method to the proteomes of the four serotypes of dengue virus and found 1,551 blocks of 9-mer peptides, which covered all available sequences with five or fewer unique peptides. In contrast, the benchmark study by Khan et al. (2008, resulted in 165 9-mers being determined as conserved. Many of the blocks are located consecutively in the proteins, so connecting these blocks resulted in 78 conserved regions which can be covered with 457 subunit peptides. Of the 1551 blocks of 9-mer peptides, 110 blocks consisted of peptides all predicted to bind to MHC with similar affinity and the same HLA restriction. In total, we identified a pool of 333 peptides as T-cell epitope candidates. This set could form the basis for a broadly neutralizing dengue virus vaccine. The peptide block entropy analysis approach significantly increases the number of conserved peptide regions in comparison to traditional conservation analysis of individual residues. We determined 457 subunit peptides with the capacity to encompass the diversity of all sequenced DENV strains.

  12. Highly Efficient One-Pot Synthesis of COS-Based Block Copolymers by Using Organic Lewis Pairs.

    Science.gov (United States)

    Yang, Jia-Liang; Cao, Xiao-Han; Zhang, Cheng-Jian; Wu, Hai-Lin; Zhang, Xing-Hong

    2018-01-31

    A one-pot synthesis of block copolymer with regioregular poly(monothiocarbonate) block is described via metal-free catalysis. Lewis bases such as guanidine, quaternary onium salts, and Lewis acid triethyl borane (TEB) were equivalently combined and used as the catalysts. By using polyethylene glycol (PEG) as the macromolecular chain transfer agent (CTA), narrow polydispersity block copolymers were obtained from the copolymerization of carbonyl sulfide (COS) and propylene oxide (PO). The block copolymers had a poly(monothiocarbonate) block with perfect alternating degree and regioregularity. Unexpectedly, the addition of CTA to COS/PO copolymerization system could dramatically improve the turnover frequency (TOF) of PO (up to 240 h -1 ), higher than that of the copolymerization without CTA. In addition, the conversion of CTA could be up to 100% in most cases, as revealed by ¹H NMR spectra. Of consequence, the number-average molecular weights ( M n s) of the resultant block copolymers could be regulated by varying the feed ratio of CTA to PO. Oxygen-sulfur exchange reaction (O/S ER), which can generate randomly distributed thiocarbonate and carbonate units, was effectively suppressed in all of the cases in the presence of CTA, even at 80 °C. This work presents a versatile method for synthesizing sulfur-containing block copolymers through a metal-free route, providing an array of new block copolymers.

  13. Structural and Mechanical Hysteresis at the Order-Order Transition of Block Copolymer Micellar Crystals

    Directory of Open Access Journals (Sweden)

    Theresa A. LaFollette

    2011-01-01

    Full Text Available Concentrated solutions of a water-soluble block copolymer (PEO20-(PPO70-(PEO20 show a thermoreversible transition from a liquid to a gel. Over a range of concentration there also exists an order-order transition (OOT between cubically-packed spherical micelles and hexagonally-packed cylindrical micelles. This OOT displays a hysteresis between the heating and cooling transitions that is observed at both the macroscale through rheology and nanoscale through small angle neutron scattering (SANS. The hysteresis is caused by the persistence of the cubically-packed spherical micelle phase into the hexagonally-packed cylindrical micelle phase likely due to the hindered realignment of the spherical micelles into cylindrical micelles and then packing of the cylindrical micelles into a hexagonally-packed cylindrical micelle phase. This type of hysteresis must be fully characterized, and possibly avoided, for these block copolymer systems to be used as templates in nanocomposites.

  14. Fast block matching algorithm based on the winner-update strategy.

    Science.gov (United States)

    Chen, Y S; Hung, Y P; Fuh, C S

    2001-01-01

    Block matching is a widely used method for stereo vision, visual tracking, and video compression. Many fast algorithms for block matching have been proposed in the past, but most of them do not guarantee that the match found is the globally optimal match in a search range. This paper presents a new fast algorithm based on the winner-update strategy which utilizes an ascending lower bound list of the matching error to determine the temporary winner. Two lower bound lists derived by using partial distance and by using Minkowski's inequality are described. The basic idea of the winner-update strategy is to avoid, at each search position, the costly computation of the matching error when there exists a lower bound larger than the global minimum matching error. The proposed algorithm can significantly speed up the computation of the block matching because: 1) computational cost of the lower bound we use is less than that of the matching error itself; 2) an element in the ascending lower bound list will be calculated only when its preceding element has already been smaller than the minimum matching error computed so far; 3) for many search positions, only the first several lower bounds in the list need to be calculated. Our experiments have shown that, when applying to motion vector estimation for several widely-used test videos, 92% to 98% of operations can be saved while still guaranteeing the global optimality. Moreover, the proposed algorithm can be easily modified either to meet the limited time requirement or to provide an ordered list of best candidate matches. Our source codes of the proposed algorithm are available at http://smart.iis.sinica.edu.tw/html/winup.html.

  15. Language identification of information blocks based on lexico-grammatic markers

    Directory of Open Access Journals (Sweden)

    Sergey N. Kalegin

    2017-12-01

    Full Text Available This article is a continuation of the author's series of publications on the subjects of language identification of texts. In the article is being considered the creation of a technological basis for language identification systems of unstructured information blocks based on lexico-grammatical markers, in which are used the forms of verbs, verbal formations or functionally analogous constructions, are described method and algorithm for its software implementation. These developments will significantly reduce the resource intensity and improve the quality of such systems, which will give a significant economic effect and the possibility of creating fundamentally new technologies for determining the linguistic affiliation of information in a multilingual environment. Consequently, the study is of interest for computer linguists and developers of automatic word processing systems, such as: global monitoring systems, multilingual knowledge bases, automatic translation systems, information retrieval systems, document summarizing systems, literature catalogers, etc.

  16. A Complete Image Compression Scheme Based on Overlapped Block Transform with Post-Processing

    Directory of Open Access Journals (Sweden)

    Li B

    2006-01-01

    Full Text Available A complete system was built for high-performance image compression based on overlapped block transform. Extensive simulations and comparative studies were carried out for still image compression including benchmark images (Lena and Barbara, synthetic aperture radar (SAR images, and color images. We have achieved consistently better results than three commercial products in the market (a Summus wavelet codec, a baseline JPEG codec, and a JPEG-2000 codec for most images that we used in this study. Included in the system are two post-processing techniques based on morphological and median filters for enhancing the perceptual quality of the reconstructed images. The proposed system also supports the enhancement of a small region of interest within an image, which is of interest in various applications such as target recognition and medical diagnosis

  17. Low-Complexity Multiple Description Coding of Video Based on 3D Block Transforms

    Directory of Open Access Journals (Sweden)

    Andrey Norkin

    2007-02-01

    Full Text Available The paper presents a multiple description (MD video coder based on three-dimensional (3D transforms. Two balanced descriptions are created from a video sequence. In the encoder, video sequence is represented in a form of coarse sequence approximation (shaper included in both descriptions and residual sequence (details which is split between two descriptions. The shaper is obtained by block-wise pruned 3D-DCT. The residual sequence is coded by 3D-DCT or hybrid, LOT+DCT, 3D-transform. The coding scheme is targeted to mobile devices. It has low computational complexity and improved robustness of transmission over unreliable networks. The coder is able to work at very low redundancies. The coding scheme is simple, yet it outperforms some MD coders based on motion-compensated prediction, especially in the low-redundancy region. The margin is up to 3 dB for reconstruction from one description.

  18. Evaluating the influence of increasing block tariffs in residential gas sector using agent-based computational economics

    International Nuclear Information System (INIS)

    Gong, Chengzhu; Yu, Shiwei; Zhu, Kejun; Hailu, Atakelty

    2016-01-01

    Designing a desirable increasing block tariff for the residential gas retail market has been a challenging task for regulated utilities, especially in China. To deal with such problems, in this paper, we establish an agent-based, computational economics system to provide a formal evaluation of the direct and indirect influences of several issued increasing block tariffs in the residential gas market. Moreover, a comprehensive demand response behaviour model has been improved in term of price elasticity, while still coping with income levels and complex social environment. We also compute and compare the outcomes of several increasing block tariffs with the initial flat tariff by running the system on a test-case using real-world data from a middle-scale gas retail market in Wuhan. The results indicate that there is an appropriate increasing block gas tariff scheme that has greater ability to improve social equity while still ensuring operator revenue and promoting gas conservation. In order to offset the limitations of the proposed increasing block tariffs, the regulator should adopt some complementary measures, such as applying appropriate policies targeting the intended consumers, and allowing large families to obtain extra allowance of volume. - Highlights: •Analyse the influence of increasing block tariffs in residential gas sector. •An agent-based computational economics system is utilised for policy analysis. •Increasing block tariff can generate revenue while still promote gas conservation. •The increasing subsidy for low income household can improve the social equity.

  19. Reliability Based Ship Structural Design

    DEFF Research Database (Denmark)

    Dogliani, M.; Østergaard, C.; Parmentier, G.

    1996-01-01

    This paper deals with the development of different methods that allow the reliability-based design of ship structures to be transferred from the area of research to the systematic application in current design. It summarises the achievements of a three-year collaborative research project dealing...... with developments of models of load effects and of structural collapse adopted in reliability formulations which aim at calibrating partial safety factors for ship structural design. New probabilistic models of still-water load effects are developed both for tankers and for containerships. New results are presented...... of non-linear wave induced load effects and the corresponding long-term formulations. Methods to combine linear and non-linear components of wave induced load effects have been developed and checked by alternative methods.These improved models were used for the reliability assessment of the primary hull...

  20. Plasmonic Glasses and Films Based on Alternative Inexpensive Materials for Blocking Infrared Radiation.

    Science.gov (United States)

    V Besteiro, Lucas; Kong, Xiang-Tian; Wang, Zhiming; Rosei, Federico; Govorov, Alexander O

    2018-04-16

    The need for energy-saving materials is pressing. This Letter reports on the design of energy-saving glasses and films based on plasmonic nanocrystals that efficiently block infrared radiation. Designing such plasmonic composite glasses is nontrivial and requires taking full advantage of both material and geometrical properties of the nanoparticles. We compute the performance of solar plasmonic glasses incorporating a transparent matrix and specially shaped nanocrystals. This performance depends on the shape and material of such nanocrystals. Glasses designed with plasmonic nanoshells are shown to exhibit overall better performances as compared to nanorods and nanocups. Simultaneously, scalable synthesis of plasmonic nanoshells and nanocups is technologically feasible using gas-phase fabrication methods. The computational simulations were performed for noble metals (gold and silver) as well as for alternative plasmonic materials (aluminum, copper, and titanium nitride). Inexpensive plasmonic materials (silver, copper, aluminum, and titanium nitride) show an overall good performance in terms of the commonly used figures of merit of industrial glass windows. Together with numerical data for specific materials, this study includes a set of general rules for designing efficient plasmonic IR-blocking media. The plasmonic glasses proposed herein are good candidates for the creation of cheap optical media, to be used in energy-saving windows in warm climates' housing or temperature-sensitive infrastructure.

  1. Application of Block Programming and Game-Based Learning to Enhance Interest in Computer Science

    Directory of Open Access Journals (Sweden)

    Todorka Glushkova

    2016-12-01

    Full Text Available More rapid development of the information society poses increasingly acute issue to increase the effectiveness of training in the field of computer science. The fact is that students prefer more applied fields of information and communication technologies in comparison with the informatics and programming. To solve this problem, leading universities and software companies develop multiple environments for block programming, which is inherently more interesting, motivating, fun and practical. It is known that game-based learning significantly increased interest and activity of the students and significantly increases the effectiveness of the training. The article will present a model for application of block programming in the development of educational games for standard and mobile devices and their application in both computer science students and secondary school students. Will be presented the experience of the team in the use of e-learning environments and implementation of these applications in developed courses. The application of the model currently shows increasing interest of all groups of students to programming. All this gives grounds for continuing the work and research in this direction.

  2. Expert evaluation of technical documentation 'Analysis of structures of blocks 1-6 of the Kozloduy NPP for the seismic effect of local earthquakes'

    International Nuclear Information System (INIS)

    Jurukovski, D.

    1999-01-01

    The subject of this expert evaluation is the technical documentation 'Analysis of structures of blocks 1-6 of the Kozloduy NPP for the seismic effect of local earthquakes'. It includes reviews of expert evaluations of the parameters of local seismic effects and the analysis of floor response spectra for blocks 3, 4, 5 and 6 at Kozloduy NPP

  3. Self-assembled structures of PMAA-PMMA block copolymers: Synthesis, characterization, and self-consistent field computations

    NARCIS (Netherlands)

    Li, F.; Schellekens, J.; Bont, de J.A.M.; Peters, R.; Overbeek, A.; Leermakers, F.A.M.; Tuinier, R.

    2015-01-01

    Block copolymers composed of methacrylic acid (MAA) and methyl methacrylate (MMA) blocks are interesting candidates for replacing surfactants in emulsion polymerization methods. Here the synthesis and experimental characterization of well-defined PMAA–PMMA block copolymers made via RAFT

  4. Self-Assembled Structures of PMAA-PMMA Block Copolymers : Synthesis, Characterization, and Self-Consistent Field Computations

    NARCIS (Netherlands)

    Li, Feng; Schellekens, Mike; de Bont, Jens; Peters, Ron; Overbeek, Ad; Leermakers, Frans A. M.; Tuinier, Remco

    2015-01-01

    Block copolymers composed of methacrylic acid (MAA) and methyl methacrylate (MMA) blocks are interesting candidates for replacing surfactants in emulsion polymerization methods. Here the synthesis and experimental characterization of well-defined PMAA-PMMA block copolymers made via RAFT

  5. Block sparsity-based joint compressed sensing recovery of multi-channel ECG signals.

    Science.gov (United States)

    Singh, Anurag; Dandapat, Samarendra

    2017-04-01

    In recent years, compressed sensing (CS) has emerged as an effective alternative to conventional wavelet based data compression techniques. This is due to its simple and energy-efficient data reduction procedure, which makes it suitable for resource-constrained wireless body area network (WBAN)-enabled electrocardiogram (ECG) telemonitoring applications. Both spatial and temporal correlations exist simultaneously in multi-channel ECG (MECG) signals. Exploitation of both types of correlations is very important in CS-based ECG telemonitoring systems for better performance. However, most of the existing CS-based works exploit either of the correlations, which results in a suboptimal performance. In this work, within a CS framework, the authors propose to exploit both types of correlations simultaneously using a sparse Bayesian learning-based approach. A spatiotemporal sparse model is employed for joint compression/reconstruction of MECG signals. Discrete wavelets transform domain block sparsity of MECG signals is exploited for simultaneous reconstruction of all the channels. Performance evaluations using Physikalisch-Technische Bundesanstalt MECG diagnostic database show a significant gain in the diagnostic reconstruction quality of the MECG signals compared with the state-of-the art techniques at reduced number of measurements. Low measurement requirement may lead to significant savings in the energy-cost of the existing CS-based WBAN systems.

  6. Vision-Based Bicycle Detection Using Multiscale Block Local Binary Pattern

    Directory of Open Access Journals (Sweden)

    Hongyu Hu

    2014-01-01

    Full Text Available Bicycle traffic has heavy proportion among all travel modes in some developing countries, which is crucial for urban traffic control and management as well as facility design. This paper proposes a real-time multiple bicycle detection algorithm based on video. At first, an effective feature called multiscale block local binary pattern (MBLBP is extracted for representing the moving object, which is a well-classified feature to distinguish between bicycles and nonbicycles; then, a cascaded bicycle classifier trained by AdaBoost algorithm is proposed, which has a good computation efficiency. Finally, the method is tested with video sequence captured from the real-world traffic scenario. The bicycles in the test scenario are successfully detected.

  7. Block-Localized Wavefunction (BLW) Based Two-State Approach for Charge Transfers between Phenyl Rings.

    Science.gov (United States)

    Mo, Yirong; Song, Lingchun; Lin, Yuchun; Liu, Minghong; Cao, Zexing; Wu, Wei

    2012-03-13

    The block-localized wave function (BLW) method is the simplest and most efficient variant of ab initio valence bond (VB) theory which defines electron-localized resonance states following the conventional VB concepts. Here, a BLW-based two-state approach is proposed to probe the charge/hole transfer reactions within the Marcus-Hush model. With this approach, both the electronic coupling and reorganization energies can be derived at the ab initio level. Pilot applications to the electron/hole transfers between two phenyl rings are presented. Good exponential correlation between the electronic coupling energy and the donor-acceptor distance is shown, whereas the inner-sphere reorganization shows little geometric dependency. Computations also support the assumption in Marcus theory that the thermal electron transfer barrier (ΔG*), which is a sum of the reaction barrier (ΔEa) for electron/hole transfer and the coupling energy (VAB), is a quarter of the reorganization energy (λ).

  8. Block-Based Compressed Sensing for Neutron Radiation Image Using WDFB

    Directory of Open Access Journals (Sweden)

    Wei Jin

    2015-01-01

    Full Text Available An ideal compression method for neutron radiation image should have high compression ratio while keeping more details of the original image. Compressed sensing (CS, which can break through the restrictions of sampling theorem, is likely to offer an efficient compression scheme for the neutron radiation image. Combining wavelet transform with directional filter banks, a novel nonredundant multiscale geometry analysis transform named Wavelet Directional Filter Banks (WDFB is constructed and applied to represent neutron radiation image sparsely. Then, the block-based CS technique is introduced and a high performance CS scheme for neutron radiation image is proposed. By performing two-step iterative shrinkage algorithm the problem of L1 norm minimization is solved to reconstruct neutron radiation image from random measurements. The experiment results demonstrate that the scheme not only improves the quality of reconstructed image obviously but also retains more details of original image.

  9. A Block-matching based technique for the analysis of 2D gel images.

    Science.gov (United States)

    Freire, Ana; Seoane, José A; Rodríguez, Alvaro; Ruiz-Romero, Cristina; López-Campos, Guillermo; Dorado, Julián

    2010-01-01

    Research at protein level is a useful practice in personalized medicine. More specifically, 2D gel images obtained after electrophoresis process can lead to an accurate diagnosis. Several computational approaches try to help the clinicians to establish the correspondence between pairs of proteins of multiple 2D gel images. Most of them perform the alignment of a patient image referred to a reference image. In this work, an approach based on block-matching techniques is developed. Its main characteristic is that it does not need to perform the whole alignment between two images considering each protein separately. A comparison with other published methods is presented. It can be concluded that this method works over broad range of proteomic images, although they have a high level of difficulty.

  10. Second-Order Polynomial Equation-Based Block Adjustment for Orthorectification of DISP Imagery

    Directory of Open Access Journals (Sweden)

    Guoqing Zhou

    2016-08-01

    Full Text Available Due to the lack of ground control points (GCPs and parameters of satellite orbits, as well as the interior and exterior orientation parameters of cameras in historical declassified intelligence satellite photography (DISP imagery, a second order polynomial equation-based block adjustment model is proposed for orthorectification of DISP imagery. With the proposed model, 355 DISP images from four missions and five orbits are orthorectified, with an approximate accuracy of 2.0–3.0 m. The 355 orthorectified images are assembled into a seamless, full-coverage mosaic image map of the karst area of Guangxi, China. The accuracy of the mosaicked image map is within 2.0–4.0 m when compared to 78 checkpoints measured by Real–Time Kinematic (RTK GPS surveys. The assembled image map will be delivered to the Guangxi Geological Library and released to the public domain and the research community.

  11. Surface tectonics of nanoporous networks of melamine-capped molecular building blocks formed through interface Schiff-base reactions.

    Science.gov (United States)

    Liu, Xuan-He; Wang, Dong; Wan, Li-Jun

    2013-10-01

    Control over the assembly of molecules on a surface is of great importance for the fabrication of molecule-based miniature devices. Melamine (MA) and molecules with terminal MA units are promising candidates for supramolecular interfacial packing patterning, owing to their multiple hydrogen-bonding sites. Herein, we report the formation of self-assembled structures of MA-capped molecules through a simple on-surface synthetic route. MA terminal groups were successfully fabricated onto rigid molecular cores with 2-fold and 3-fold symmetry through interfacial Schiff-base reactions between MA and aldehyde groups. Sub-molecular scanning tunneling microscopy (STM) imaging of the resultant adlayer revealed the formation of nanoporous networks. Detailed structural analysis indicated that strong hydrogen-bonding interactions between the MA groups persistently drove the formation of nanoporous networks. Herein, we demonstrate that functional groups with strong hydrogen-bond-formation ability are promising building blocks for the guided assembly of nanoporous networks and other hierarchical 2D assemblies. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. THE FAULT-BLOCK STRUCTURE OF THE BAIKAL-YENISEI FAULT IN THE REGION OF OPERATING NUCLEAR ENERGY FACILITIES

    Directory of Open Access Journals (Sweden)

    R. M. Lobatskaya

    2014-01-01

    Full Text Available The article reviews specific features of its fault-block structure of the Baikal-Yenisei fault in view of safe operations of nuclear energy facilities in the Krasnoyarsk region, Russia. The fault is located at the junction of the Siberian platform and the West Siberian plate. Velocities of neotectonic movements in the fault zone and adjacent territories are estimated from data on the current positions of fluvial terraces of the Yenisei river valley, peneplanation planes varying in ages and erosional incision depths. It is revealed that maximum gradients of recent movement velocities vary not higher than 10–8 to 10–9. Average velocities of relative displacements amount to 0.1–0.2 mm per year for intra-fault blocks bounded by regional faults and do not exceed 0.02–0.03 mm per year for intra-fault blocks bordered by local faults. There are grounds to conclude that recent geodynamic activity in the zone of the Baikal-Yenisei fault zone is weak and thus does not affect the safety of nuclear energy facilities operating in the region, including FGUP GKhK (Mining and Chemical Combine.

  13. Surprising transformation of a block copolymer into a high performance polystyrene ultrafiltration membrane with a hierarchically organized pore structure

    KAUST Repository

    Shevate, Rahul

    2018-02-08

    We describe the preparation of hierarchical polystyrene nanoporous membranes with a very narrow pore size distribution and an extremely high porosity. The nanoporous structure is formed as a result of unusual degradation of the poly(4-vinyl pyridine) block from self-assembled poly(styrene)-b-poly(4-vinyl pyridine) (PS-b-P4VP) membranes through the formation of an unstable pyridinium intermediate in an alkaline medium. During this process, the confined swelling and controlled degradation produced a tunable pore size. We unequivocally confirmed the successful elimination of the P4VP block from a PS-b-P4VPVP membrane using 1D/2D NMR spectroscopy and other characterization techniques. Surprisingly, the long range ordered surface porosity was preserved even after degradation of the P4VP block from the main chain of the diblock copolymer, as revealed by SEM. Aside from a drastically improved water flux (∼67% increase) compared to the PS-b-P4VP membrane, the hydraulic permeability measurements validated pH independent behaviour of the isoporous PS membrane over a wide pH range from 3 to 10. The effect of the pore size on protein transport rate and selectivity (a) was investigated for lysozyme (Lys), bovine serum albumin (BSA) and globulin-γ (IgG). A high selectivity of 42 (Lys/IgG) and 30 (BSA/IgG) was attained, making the membranes attractive for size selective separation of biomolecules from their synthetic model mixture solutions.

  14. Markov model-based polymer assembly from force field-parameterized building blocks.

    Science.gov (United States)

    Durmaz, Vedat

    2015-03-01

    A conventional by hand construction and parameterization of a polymer model for the purpose of molecular simulations can quickly become very work-intensive and time-consuming. Using the example of polyglycerol, I present a polymer decomposition strategy yielding a set of five monomeric residues that are convenient for an instantaneous assembly and subsequent force field simulation of a polyglycerol polymer model. Force field parameters have been developed in accordance with the classical Amber force field. Partial charges of each unit were fitted to the electrostatic potential using quantum-chemical methods and slightly modified in order to guarantee a neutral total polymer charge. In contrast to similarly constructed models of amino acid and nucleotide sequences, the glycerol building blocks may yield an arbitrary degree of bifurcations depending on the underlying probabilistic model. The iterative development of the overall structure as well as the relation of linear to branching units is controlled by a simple Markov model which is presented with few algorithmic details. The resulting polymer is highly suitable for classical explicit water molecular dynamics simulations on the atomistic level after a structural relaxation step. Moreover, the decomposition strategy presented here can easily be adopted to many other (co)polymers.

  15. A pruning algorithm for Meta-blocking based on cumulative weight

    Science.gov (United States)

    Zhang, Fulin; Gao, Zhipeng; Niu, Kun

    2017-08-01

    Entity Resolution is an important process in data cleaning and data integration. It usually employs a blocking method to avoid the quadratic complexity work when scales to large data sets. Meta-blocking can perform better in the context of highly heterogeneous information spaces. Yet, its precision and efficiency still have room to improve. In this paper, we present a new pruning algorithm for Meta-Blocking. It can achieve a higher precision than the existing WEP algorithm at a small cost of recall. In addition, can reduce the runtime of the blocking process. We evaluate our proposed method over five real-world data sets.

  16. Enhancement of Endurance in HfO2-Based CBRAM Device by Introduction of a TaN Diffusion Blocking Layer

    KAUST Repository

    Chand, Umesh

    2017-08-05

    We propose a new method to improve resistive switching properties in HfO2 based CBRAM crossbar structure device by introducing a TaN thin diffusion blocking layer between the Cu top electrode and HfO2 switching layer. The Cu/TaN/HfO2/TiN device structure exhibits high resistance ratio of OFF/ON states without any degradation in switching during endurance test. The improvement in the endurance properties of the Cu/TaN/HfO2/TiN CBRAM device is thus attributed to the relatively low amount of Cu migration into HfO2 switching layer.

  17. Reversible Dual-Image-Based Hiding Scheme Using Block Folding Technique

    Directory of Open Access Journals (Sweden)

    Tzu-Chuen Lu

    2017-10-01

    Full Text Available The concept of a dual-image based scheme in information sharing consists of concealing secret messages in two cover images; only someone who has both stego-images can extract the secret messages. In 2015, Lu et al. proposed a center-folding strategy where each secret symbol is folded into the reduced digit to reduce the distortion of the stego-image. Then, in 2016, Lu et al. used a frequency-based encoding strategy to reduce the distortion of the frequency of occurrence of the maximum absolute value. Because the folding strategy can obviously reduce the value, the proposed scheme includes the folding operation twice to further decrease the reduced digit. We use a frequency-based encoding strategy to encode a secret message and then use the block folding technique by performing the center-folding operation twice to embed secret messages. An indicator is needed to identify the sequence number of the folding operation. The proposed scheme collects several indicators to produce a combined code and hides the code in a pixel to reduce the size of the indicators. The experimental results show that the proposed method can achieve higher image quality under the same embedding rate or higher payload, which is better than other methods.

  18. Rapid block matching based nonlinear registration on GPU for image guided radiation therapy

    Science.gov (United States)

    Wang, An; Disher, Brandon; Carnes, Greg; Peters, Terry M.

    2010-02-01

    To compensate for non-uniform deformation due to patient motion within and between fractions in image guided radiation therapy, a block matching technique was adapted and implemented on a standard graphics processing unit (GPU) to determine the displacement vector field that maps the nonlinear transformation between successive CT images. Normalized cross correlation (NCC) was chosen as the similarity metric for the matching step, with regularization of the displacement vector field being performed by Gaussian smoothing. A multi-resolution framework was adopted to further improve the performance of the algorithm. The nonlinear registration algorithm was first applied to estimate the intrafractional motion from 4D lung CT images. It was also used to calculate the inter-fractional organ deformation between planning CT (PCT) and Daily Cone Beam CT (CBCT) images of thorax. For both experiments, manual landmark-based evaluation was performed to quantify the registration performance. In 4D CT registration, the mean TRE of 5 cases was 1.75 mm. In PCT-CBCT registration, the TRE of one case was 2.26mm. Compared to the CPU-based AtamaiWarp program, our GPU-based implementation achieves comparable registration accuracy and is ~25 times faster. The results highlight the potential utility of our algorithm for online adaptive radiation treatment.

  19. A blocked takeover in the Polish power sector: A model-based analysis

    International Nuclear Information System (INIS)

    Kamiński, Jacek

    2014-01-01

    As the President of the Office of Competition and Consumer Protection refused to approve a government initiated takeover in the Polish power sector and the Court of Competition and Consumer Protection did not make a ruling on that case, the takeover was finally prohibited. In this context, the main aim of this paper is to carry out a quantitative analysis of the impact of the takeover in question on electricity prices and quantities, consumer and producer surpluses, dead weight loss and emissions. The scope of the study covers the Polish power generation sector and the analysis was carried out for 2009. A game theory-based electricity market equilibrium model developed for Poland was applied. The model includes several country-specific conditions, such as a coal-based power generation fuel-mix, a large share of biomass co-combustion, etc. For the sake of clarity, only four scenarios are assumed. The paper concludes that the declared synergy savings did not compensate for the increase in dead weight loss and the transfer of surplus from consumers to producers caused by increased market power. - Highlights: • A takeover blocked by the President of the Office of Competition and Consumer Protection was analysed. • A game theory-based model of the Polish wholesale electricity market was applied. • The impact of the takeover on electricity prices and generation levels, surplus transfers and dead weight loss was estimated. • The results were compared with the declared synergy savings

  20. Reliability-based optimization of engineering structures

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard

    2008-01-01

    The theoretical basis for reliability-based structural optimization within the framework of Bayesian statistical decision theory is briefly described. Reliability-based cost benefit problems are formulated and exemplitied with structural optimization. The basic reliability-based optimization prob...

  1. Vibration-based structural health monitoring of harbor caisson structure

    Science.gov (United States)

    Lee, So-Young; Lee, So-Ra; Kim, Jeong-Tae

    2011-04-01

    This study presents vibration-based structural health monitoring method in foundation-structure interface of harbor caisson structure. In order to achieve the objective, the following approaches are implemented. Firstly, vibration-based response analysis method is selected and structural health monitoring (SHM) technique is designed for harbor caisson structure. Secondly, the performance of designed SHM technique for harbor structure is examined by FE analysis. Finally, the applicability of designed SHM technique for harbor structure is evaluated by dynamic tests on a lab-scaled caisson structure.

  2. A Slicing Tree Representation and QCP-Model-Based Heuristic Algorithm for the Unequal-Area Block Facility Layout Problem

    Directory of Open Access Journals (Sweden)

    Mei-Shiang Chang

    2013-01-01

    Full Text Available The facility layout problem is a typical combinational optimization problem. In this research, a slicing tree representation and a quadratically constrained program model are combined with harmony search to develop a heuristic method for solving the unequal-area block layout problem. Because of characteristics of slicing tree structure, we propose a regional structure of harmony memory to memorize facility layout solutions and two kinds of harmony improvisation to enhance global search ability of the proposed heuristic method. The proposed harmony search based heuristic is tested on 10 well-known unequal-area facility layout problems from the literature. The results are compared with the previously best-known solutions obtained by genetic algorithm, tabu search, and ant system as well as exact methods. For problems O7, O9, vC10Ra, M11*, and Nug12, new best solutions are found. For other problems, the proposed approach can find solutions that are very similar to previous best-known solutions.

  3. Automation of block assignment planning using a diagram-based scenario modeling method

    Science.gov (United States)

    Hwang, In Hyuck; Kim, Youngmin; Lee, Dong Kun; Shin, Jong Gye

    2014-03-01

    Most shipbuilding scheduling research so far has focused on the load level on the dock plan. This is be¬cause the dock is the least extendable resource in shipyards, and its overloading is difficult to resolve. However, once dock scheduling is completed, making a plan that makes the best use of the rest of the resources in the shipyard to minimize any additional cost is also important. Block assignment planning is one of the midterm planning tasks; it assigns a block to the facility (factory/shop or surface plate) that will actually manufacture the block according to the block characteristics and current situation of the facility. It is one of the most heavily loaded midterm planning tasks and is carried out manu¬ally by experienced workers. In this study, a method of representing the block assignment rules using a diagram was su¬ggested through analysis of the existing manual process. A block allocation program was developed which automated the block assignment process according to the rules represented by the diagram. The planning scenario was validated through a case study that compared the manual assignment and two automated block assignment results.

  4. Well-Defined Polyethylene-Based Random, Block, and Bilayered Molecular Cobrushes

    KAUST Repository

    Zhang, Hefeng

    2015-06-09

    Novel well-defined polyethylene-based random, block, and bilayered molecular cobrushes were synthesized through the macromonomer strategy. Two steps were involved in this approach: (i) synthesis of norbornyl-terminated macromonomers of polyethylene (PE), polycaprolactone (PCL), poly(ethylene oxide) (PEO), and polystyrene (PS), as well as polyethylene-b-polycaprolactone (PE-b-PCL), by esterification of the hydroxyl-terminated precursors (PE, PCL, PEO, PS, and PE-b-PCL) with 5-norbornene-2-carboxylic acid and (ii) ring-opening metathesis (co)polymerization of the resulting macromonomers to afford the PE-based molecular cobrushes. The PE-macromonomers were synthesized by polyhomologation of dimethylsulfoxonium methylide, while the others by anionic polymerization. Proton nuclear magnetic resonance spectroscopy (1H NMR) and high-temperature gel permeation chromatography (HT-GPC) were used to imprint the molecular characteristics of all macromonomers and molecular brushes and differential scanning calorimetry (DSC) for the thermal properties. The bilayered molecular cobrushes of P(PE-b-PCL) adopt a wormlike morphology on silica wafer as visualized by atomic force microscopy (AFM). © 2015 American Chemical Society.

  5. Small scale test for seismic response control structure using block & tackle

    Science.gov (United States)

    Zaman, Faisal bin; Suzuki, Yoshiaki; Hayashi, Kazuhiro; Saito, Taiki

    2017-10-01

    An innovative and economic seismic response control system using block and tackle system (hereinafter referred as movable pulley damper system) is under development. In order to clarify the influence of friction between the pulley and the wire, a wire was applied to multiple pulleys and a static force test in which a weight was hung on one side was performed. The frictional force was measured in different test cases by changing the number of loops of the wire and the weight value. If we divide the frictional force by the weight and the number of grooves of pulley, the results show a relatively constant friction coefficient. Then, a dynamic shaking table test using a two story specimen was conducted. Similar to the static test, the frictional force was measured in test cases by changing the number of loops of the wire, the initial tension force of the wire and the amplitude of input sine wave. The obtained friction coefficient was almost the same value of the static test that means the friction coefficient does not change so much between static and dynamic loading conditions.

  6. Self-assembled nanoparticles from a block polyelectrolyte in aqueous media: structural characterization by SANS.

    Science.gov (United States)

    Papagiannopoulos, Aristeidis; Karayianni, Maria; Mountrichas, Grigoris; Pispas, Stergios; Radulescu, Aurel

    2010-06-10

    We present a small angle neutron scattering (SANS) study of polystyrene-b-sodium (sulfamate/carboxylate) isoprene (PS-PSCI) nanoparticles in aqueous media. The SANS experiments are complemented by static and dynamic light scattering measurements. A detailed analysis of the scattering form factor obtained by SANS for the self-assembled block polyelectrolyte spherical nanoparticles implies a two-region power-law model for the radial volume fraction profiles. The theoretically predicted scaling of the osmotic brush regime phi(r) approximately r(-2) for the inner region and the osmotic annealing brush regime phi(r) approximately r(-8/3) for the outer region are in agreement with our experimental findings. A concentrated shell of PSCI polyelectrolyte chains collapsed on the polystyrene core is needed in the form factor analysis so that the aggregation number of the nanoparticles is self-consistent. The self-assembled nanoparticles are found to be kinetically frozen i.e. their aggregation number is not sensitive to the solution conditions and is defined by the preparation protocol. The size of the spherical nanoparticles tends to decrease upon the addition of salt and the drop of pH.

  7. The role of focal block (trough/plane) in panoramic radiography: Why do some structures appear blurred out on these images?

    International Nuclear Information System (INIS)

    Ramakrishna Pawar, Ravikiran; Makdissi, J.

    2014-01-01

    Panoramic radiographs are commonly used in dental practice. The challenge with panoramic radiography is overlapping structures, ghost and air shadows. The area of interest can appear blurred especially in the anterior region. The focal block is a virtual space in which the dentition should be perfectly placed when acquiring the radiograph. Anatomical structures that are within this focal block appear focused and in perfect geometric accuracy on the final image. Structures outside this focal block appear blurred, and distorted. Accurate positioning of the patient will help in placing the region of interest within in the focal block and as a result minimising artefacts, ghost and air shadows. We utilise cone beam computed tomography (CBCT) software to explain this principle

  8. Lithosphere Structure of the Rivera Plate - Jalisco Block Contact Zone: Septentrional Region of the Islas Marías (Mexico)

    Science.gov (United States)

    Madrigal-Ávalos, L. A.; Nunez, D.; Escalona-Alcazar, F. D. J.; Nuñez-Cornu, F. J.; Barba, D. C., Sr.; Danobeitia, J.

    2017-12-01

    The western margin of Mexico is a tectonic complex region where large earthquakes occurred with very destructive consequences, including the generation of big tsunamis. This fact is mainly the result of the Rivera plate subduction beneath the North American plate and the Jalisco Block implying a high potential seismic risk. In the north, between the Tamayo Fracture Zone and the Mesoamerican Trench, the Islas Marías region is a complex tectonic limit within the interaction of the Rivera plate oceanic crust and the Jalisco Block continental crust. In order to know the shallow and deep structure of the Rivera plate - Jalisco Block contact zone and to be able to determine these potential seismic sources, the TSUJAL geophysical experiment was carried out from 2012 to 2016. As part of this project, we present the results of the processed and analyzed MCS and WAS data along the TS09 and RTSIM01 seismic transects, respectively, across the septentrional region of Islas Marías. These marine seismic lines are coincident with 110 km length for MCS and 240 km for WAS, and perpendicular to the coastline with SW-NE orientation. The seismic sources used in this work aboard RRS James Cook consisted of 12 guns with a total capacity for WAS data of 5800 in3 every 120 s and 3540 in3 every 50 m for MCS data. The MCS data were acquired with a 5.85 km length streamer with a 468 active channels, while the WAS data were recorded by a network of 4 OBS and 27 land seismic stations. After data processing and joint interpretation, it was possible to determine that shallow structure is mainly constituted by normal faults associated to graben structures forming sedimentary basins with non-deformed sediments in the basement. While the deep structure is characterized by depths from 9 to 12 km in the oceanic crust and 18 to 21 km in the continental crust. The deepest layers of the upper mantle were determined up to 35 km depth. In this study, it was possible to calculate a dip angle between 6

  9. A Type-2 Block-Component-Decomposition Based 2D AOA Estimation Algorithm for an Electromagnetic Vector Sensor Array

    Directory of Open Access Journals (Sweden)

    Yu-Fei Gao

    2017-04-01

    Full Text Available This paper investigates a two-dimensional angle of arrival (2D AOA estimation algorithm for the electromagnetic vector sensor (EMVS array based on Type-2 block component decomposition (BCD tensor modeling. Such a tensor decomposition method can take full advantage of the multidimensional structural information of electromagnetic signals to accomplish blind estimation for array parameters with higher resolution. However, existing tensor decomposition methods encounter many restrictions in applications of the EMVS array, such as the strict requirement for uniqueness conditions of decomposition, the inability to handle partially-polarized signals, etc. To solve these problems, this paper investigates tensor modeling for partially-polarized signals of an L-shaped EMVS array. The 2D AOA estimation algorithm based on rank- ( L 1 , L 2 , · BCD is developed, and the uniqueness condition of decomposition is analyzed. By means of the estimated steering matrix, the proposed algorithm can automatically achieve angle pair-matching. Numerical experiments demonstrate that the present algorithm has the advantages of both accuracy and robustness of parameter estimation. Even under the conditions of lower SNR, small angular separation and limited snapshots, the proposed algorithm still possesses better performance than subspace methods and the canonical polyadic decomposition (CPD method.

  10. Production in Pichia pastoris of protein-based polymers with small heterodimer-forming blocks

    NARCIS (Netherlands)

    Domeradzka, N.E.; Werten, M.W.T.; Vries, de R.J.; Wolf, de F.A.

    2016-01-01

    Some combinations of leucine zipper peptides are capable of forming a-helical heterodimeric coiled coils with very high affinity. These can be used as physical cross-linkers in the design of protein-based polymers that form supramolecular structures, for example hydrogels, upon mixing solutions

  11. Quality-aware features-based noise level estimator for block matching and three-dimensional filtering algorithm

    Science.gov (United States)

    Xu, Shaoping; Hu, Lingyan; Yang, Xiaohui

    2016-01-01

    The performance of conventional denoising algorithms is usually controlled by one or several parameters whose optimal settings depend on the contents of the processed images and the characteristics of the noises. Among these parameters, noise level is a fundamental parameter that is always assumed to be known by most of the existing denoising algorithms (so-called nonblind denoising algorithms), which largely limits the applicability of these nonblind denoising algorithms in many applications. Moreover, these nonblind algorithms do not always achieve the best denoised images in visual quality even when fed with the actual noise level parameter. To address these shortcomings, in this paper we propose a new quality-aware features-based noise level estimator (NLE), which consists of quality-aware features extraction and optimal noise level parameter prediction. First, considering that image local contrast features convey important structural information that is closely related to image perceptual quality, we utilize the marginal statistics of two local contrast operators, i.e., the gradient magnitude and the Laplacian of Gaussian (LOG), to extract quality-aware features. The proposed quality-aware features have very low computational complexity, making them well suited for time-constrained applications. Then we propose a learning-based framework where the noise level parameter is estimated based on the quality-aware features. Based on the proposed NLE, we develop a blind block matching and three-dimensional filtering (BBM3D) denoising algorithm which is capable of effectively removing additive white Gaussian noise, even coupled with impulse noise. The noise level parameter of the BBM3D algorithm is automatically tuned according to the quality-aware features, guaranteeing the best performance. As such, the classical block matching and three-dimensional algorithm can be transformed into a blind one in an unsupervised manner. Experimental results demonstrate that the

  12. Effects of withdrawal rate and starter block size on crystal orientation of a single crystal Ni-based superalloy

    Science.gov (United States)

    Rezaei, M.; Kermanpur, A.; Sadeghi, F.

    2018-03-01

    Fabrication of single crystal (SC) Ni-based gas turbine blades with a minimum crystal misorientation has always been a challenge in gas turbine industry, due to its significant influence on high temperature mechanical properties. This paper reports an experimental investigation and numerical simulation of the SC solidification process of a Ni-based superalloy to study effects of withdrawal rate and starter block size on crystal orientation. The results show that the crystal misorientation of the sample with 40 mm starter block height is decreased with increasing withdrawal rate up to about 9 mm/min, beyond which the amount of misorientation is increased. It was found that the withdrawal rate, height of the starter block and temperature gradient are completely inter-dependent and indeed achieving a SC specimen with a minimum misorientation needs careful optimization of these process parameters. The height of starter block was found to have higher impact on crystal orientation compared to the withdrawal rate. A suitable withdrawal rate regime along with a sufficient starter block height was proposed to produce SC parts with the lowest misorientation.

  13. Microstructure and structural phase transitions in iron-based superconductors

    International Nuclear Information System (INIS)

    Wang Zhen; Cai Yao; Yang Huai-Xin; Tian Huan-Fang; Wang Zhi-Wei; Ma Chao; Chen Zhen; Li Jian-Qi

    2013-01-01

    Crystal structures and microstructural features, such as structural phase transitions, defect structures, and chemical and structural inhomogeneities, are known to have profound effects on the physical properties of superconducting materials. Recently, many studies on the structural properties of Fe-based high-T c superconductors have been published. This review article will mainly focus on the typical microstructural features in samples that have been well characterized by physical measurements. (i) Certain common structural features are discussed, in particular, the crystal structural features for different superconducting families, the local structural distortions in the Fe 2 Pn 2 (Pn = P As, Sb) or Fe 2 Ch 2 (Ch = S, Se, Te) blocks, and the structural transformations in the 122 system. (ii) In FeTe(Se) (11 family), the superconductivity, chemical and structural inhomogeneities are investigated and discussed in correlation with superconductivity. (iii) In the K 0.8 Fe 1.6+x Se 2 system, we focus on the typical compounds with emphasis on the Fe-vacancy order and phase separations. The microstructural features in other superconducting materials are also briefly discussed. (topical review - iron-based high temperature superconductors)

  14. Structural analysis of ceramic blocks sealing or structural incorporated with the industrial laundry sludge; Anllise estrutural de blocos ceramicos de vedacao ou estruturais incorporados com lodo de lavanderia industrial

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, P.H.S.; Grippe, V.Y.Q.; Goulart, J.V., E-mail: phsoal@yahoo.com.br [Universidade Federal de Mato Grosso (UFMT), MT (Brazil)

    2016-07-01

    Industrial and commercial development of recent decades has led to an increase in waste generation. Thus, it is necessary to develop alternative and effective methods of treatment, replacing the simple disposal of these wastes in landfills. The objective of this work is to study the incorporation of textile industrial laundries sludge in ceramic blocks sealing or structural. Samples of ceramic blocks were produced using formulation with 20% sludge, the mass of ceramic clay. Structural analysis of the block was observed the tendency of most empty emergence (pores) during the firing of the blocks, as textile sludge was added in the ceramic paste composition. The mechanical testing of blocks compressive strength was above the minimum 3.0 MPa specified by the standard limit. The physical test water absorption of the blocks was within the range 8 to 22% specified by the standard. (author)

  15. Block matching sparsity regularization-based image reconstruction for incomplete projection data in computed tomography

    Science.gov (United States)

    Cai, Ailong; Li, Lei; Zheng, Zhizhong; Zhang, Hanming; Wang, Linyuan; Hu, Guoen; Yan, Bin

    2018-02-01

    In medical imaging many conventional regularization methods, such as total variation or total generalized variation, impose strong prior assumptions which can only account for very limited classes of images. A more reasonable sparse representation frame for images is still badly needed. Visually understandable images contain meaningful patterns, and combinations or collections of these patterns can be utilized to form some sparse and redundant representations which promise to facilitate image reconstructions. In this work, we propose and study block matching sparsity regularization (BMSR) and devise an optimization program using BMSR for computed tomography (CT) image reconstruction for an incomplete projection set. The program is built as a constrained optimization, minimizing the L1-norm of the coefficients of the image in the transformed domain subject to data observation and positivity of the image itself. To solve the program efficiently, a practical method based on the proximal point algorithm is developed and analyzed. In order to accelerate the convergence rate, a practical strategy for tuning the BMSR parameter is proposed and applied. The experimental results for various settings, including real CT scanning, have verified the proposed reconstruction method showing promising capabilities over conventional regularization.

  16. Bundle Block Adjustment of Airborne Three-Line Array Imagery Based on Rotation Angles

    Directory of Open Access Journals (Sweden)

    Yongjun Zhang

    2014-05-01

    Full Text Available In the midst of the rapid developments in electronic instruments and remote sensing technologies, airborne three-line array sensors and their applications are being widely promoted and plentiful research related to data processing and high precision geo-referencing technologies is under way. The exterior orientation parameters (EOPs, which are measured by the integrated positioning and orientation system (POS of airborne three-line sensors, however, have inevitable systematic errors, so the level of precision of direct geo-referencing is not sufficiently accurate for surveying and mapping applications. Consequently, a few ground control points are necessary to refine the exterior orientation parameters, and this paper will discuss bundle block adjustment models based on the systematic error compensation and the orientation image, considering the principle of an image sensor and the characteristics of the integrated POS. Unlike the models available in the literature, which mainly use a quaternion to represent the rotation matrix of exterior orientation, three rotation angles are directly used in order to effectively model and eliminate the systematic errors of the POS observations. Very good experimental results have been achieved with several real datasets that verify the correctness and effectiveness of the proposed adjustment models.

  17. [Winter wheat yield gap between field blocks based on comparative performance analysis].

    Science.gov (United States)

    Chen, Jian; Wang, Zhong-Yi; Li, Liang-Tao; Zhang, Ke-Feng; Yu, Zhen-Rong

    2008-09-01

    Based on a two-year household survey data, the yield gap of winter wheat in Quzhou County of Hebei Province, China in 2003-2004 was studied through comparative performance analysis (CPA). The results showed that there was a greater yield gap (from 4.2 to 7.9 t x hm(-2)) between field blocks, with a variation coefficient of 0.14. Through stepwise forward linear multiple regression, it was found that the yield model with 8 selected variables could explain 63% variability of winter wheat yield. Among the variables selected, soil salinity, soil fertility, and irrigation water quality were the most important limiting factors, accounting for 52% of the total yield gap. Crop variety was another important limiting factor, accounting for 14%; while planting date, fertilizer type, disease and pest, and water press accounted for 7%, 14%, 10%, and 3%, respectively. Therefore, besides soil and climate conditions, management practices occupied the majority of yield variability in Quzhou County, suggesting that the yield gap could be reduced significantly through optimum field management.

  18. GPU-Based Block-Wise Nonlocal Means Denoising for 3D Ultrasound Images

    Directory of Open Access Journals (Sweden)

    Liu Li

    2013-01-01

    Full Text Available Speckle suppression plays an important role in improving ultrasound (US image quality. While lots of algorithms have been proposed for 2D US image denoising with remarkable filtering quality, there is relatively less work done on 3D ultrasound speckle suppression, where the whole volume data rather than just one frame needs to be considered. Then, the most crucial problem with 3D US denoising is that the computational complexity increases tremendously. The nonlocal means (NLM provides an effective method for speckle suppression in US images. In this paper, a programmable graphic-processor-unit- (GPU- based fast NLM filter is proposed for 3D ultrasound speckle reduction. A Gamma distribution noise model, which is able to reliably capture image statistics for Log-compressed ultrasound images, was used for the 3D block-wise NLM filter on basis of Bayesian framework. The most significant aspect of our method was the adopting of powerful data-parallel computing capability of GPU to improve the overall efficiency. Experimental results demonstrate that the proposed method can enormously accelerate the algorithm.

  19. Social Vulnerability Index (SoVI) for New Hampshire based on 2000 Census Block Groups

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data depicts the social vulnerability of New Hampshire census block groups to environmental hazards. Data were culled primarily from the 2000 Decennial Census.

  20. Social Vulnerability Index (SoVI) for Alaska based on 2000 Census Block Groups

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data depicts the social vulnerability of Alaska census block groups to environmental hazards. Data were culled primarily from the 2000 Decennial Census.

  1. Social Vulnerability Index (SoVI) for Massachusetts based on 2000 Census Block Groups

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data depicts the social vulnerability of Massachusetts census block groups to environmental hazards. Data were culled primarily from the 2000 Decennial Census.

  2. Social Vulnerability Index (SoVI) for Maryland based on 2000 Census Block Groups

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data depicts the social vulnerability of Maryland census block groups to environmental hazards. Data were culled primarily from the 2000 Decennial Census.

  3. Social Vulnerability Index (SoVI) for Washington based on 2000 Census Block Groups

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data depicts the social vulnerability of Washington census block groups to environmental hazards. Data were culled primarily from the 2000 Decennial Census.

  4. Social Vulnerability Index (SoVI) for Maine based on 2000 Census Block Groups

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data depicts the social vulnerability of Maine census block groups to environmental hazards. Data were culled primarily from the 2000 Decennial Census.

  5. Social Vulnerability Index (SoVI) for Delaware based on 2000 Census Block Groups

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data depicts the social vulnerability of Delaware census block groups to environmental hazards. Data were culled primarily from the 2000 Decennial Census.

  6. Social Vulnerability Index (SoVI) for Texas based on 2000 Census Block Groups

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data depicts the social vulnerability of Texas census block groups to environmental hazards. Data were culled primarily from the 2000 Decennial Census.

  7. Social Vulnerability Index (SoVI) for Michigan based on 2000 Census Block Groups

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data depicts the social vulnerability of Michigan census block groups to environmental hazards. Data were culled primarily from the 2000 Decennial Census.

  8. Social Vulnerability Index (SoVI) for Connecticut based on 2000 Census Block Groups

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data depicts the social vulnerability of Connecticut census block groups to environmental hazards. Data were culled primarily from the 2000 Decennial Census.

  9. Social Vulnerability Index (SoVI) for Louisiana based on 2000 Census Block Groups

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data depicts the social vulnerability of Louisiana census block groups to environmental hazards. Data were culled primarily from the 2000 Decennial Census.

  10. Social Vulnerability Index (SoVI) for New York based on 2000 Census Block Groups

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data depicts the social vulnerability of New York census block groups to environmental hazards. Data were culled primarily from the 2000 Decennial Census.

  11. Social Vulnerability Index (SoVI) for Rhode Island based on 2000 Census Block Groups

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data depicts the social vulnerability of Rhode Island census block groups to environmental hazards. Data were culled primarily from the 2000 Decennial Census.

  12. Social Vulnerability Index (SoVI) for Ohio based on 2000 Census Block Groups

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data depicts the social vulnerability of Ohio census block groups to environmental hazards. Data were culled primarily from the 2000 Decennial Census.

  13. Social Vulnerability Index (SoVI) for Illinois based on 2000 Census Block Groups

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data depicts the social vulnerability of Illinois census block groups to environmental hazards. Data were culled primarily from the 2000 Decennial Census.

  14. Social Vulnerability Index (SoVI) for Virginia based on 2000 Census Block Groups

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data depicts the social vulnerability of Virginia census block groups to environmental hazards. Data were culled primarily from the 2000 Decennial Census.

  15. Social Vulnerability Index (SoVI) for Pennsylvania based on 2000 Census Block Groups

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data depicts the social vulnerability of Pennsylvania census block groups to environmental hazards. Data were culled primarily from the 2000 Decennial Census.

  16. Social Vulnerability Index (SoVI) for Alabama based on 2000 Census Block Groups

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data depicts the social vulnerability of Alabama census block groups to environmental hazards. Data were culled primarily from the 2000 Decennial Census.

  17. Social Vulnerability Index (SoVI) for Wisconsin based on 2000 Census Block Groups

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data depicts the social vulnerability of Wisconsin census block groups to environmental hazards. Data were culled primarily from the 2000 Decennial Census.

  18. Social Vulnerability Index (SoVI) for Indiana based on 2000 Census Block Groups

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data depicts the social vulnerability of Indiana census block groups to environmental hazards. Data were culled primarily from the 2000 Decennial Census.

  19. Social Vulnerability Index (SoVI) for Mississippi based on 2000 Census Block Groups

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data depicts the social vulnerability of Mississippi census block groups to environmental hazards. Data were culled primarily from the 2000 Decennial Census.

  20. Social Vulnerability Index (SoVI) for New Jersey based on 2000 Census Block Groups

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data depicts the social vulnerability of New Jersey census block groups to environmental hazards. Data were culled primarily from the 2000 Decennial Census.

  1. Social Vulnerability Index (SoVI) for Georgia based on 2000 Census Block Groups

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data depicts the social vulnerability of Georgia census block groups to environmental hazards. Data were culled primarily from the 2000 Decennial Census.

  2. Social Vulnerability Index (SoVI) for South Carolina based on 2000 Census Block Groups

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data depicts the social vulnerability of South Carolina census block groups to environmental hazards. Data were culled primarily from the 2000 Decennial Census.

  3. Social Vulnerability Index (SoVI) for Hawaii based on 2000 Census Block Groups

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data depicts the social vulnerability of Hawaii census block groups to environmental hazards. Data were culled primarily from the 2000 Decennial Census.

  4. Social Vulnerability Index (SoVI) for Oregon based on 2000 Census Block Groups

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data depicts the social vulnerability of Oregon census block groups to environmental hazards. Data were culled primarily from the 2000 Decennial Census.

  5. A Signal Coordination Control Based on Traversing Empty between Mid-Block Street Crossing and Intersection

    Directory of Open Access Journals (Sweden)

    Changjiang Zheng

    2012-01-01

    Full Text Available To solve the problem in pedestrian Mid-Block street crossing, the method of signal coordination control between mid-block street crossing and intersection is researched in this paper. The paper proposes to use “distance-flow rate-time” graph as the tool for building coordination control system model which is for different situations of traffic control. Through alternating the linear optimization model, the system outputs the distribution of signal timing and system operational factors (delays in vehicles and mid-block street crossing. Finally, taking one section on the Taiping North Road in Nanjing as an example, the signal coordination control is carried out. And the results which are delays in the vehicles and mid-block street crossing are compared to those in the current distribution of signal timing.

  6. Social Vulnerability Index (SoVI) for Coastal States based on 2000 Census Block Groups

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data depicts the social vulnerability of coastal states census block groups to environmental hazards. Data were culled primarily from the 2000 Decennial Census.

  7. Nanoscale battery materials based on the self-assembly of block copolymers

    Science.gov (United States)

    Bullock, Steven E.; Kofinas, Peter

    An ionically conducting block copolymer was used as a template for the synthesis and confinement of lithium manganese oxide nanoparticles. The block copolymer functions as a polyelectrolyte and as a composite anode in a lithium battery system. Impedance spectroscopy and galvanostatic testing, X-ray diffraction and transmission electron microscopy were used to characterize the anode and polyelectrolyte. Galvanostatic testing indicates 300 or more cycles were possible without appreciable capacity fade.

  8. Isoelectric Bovine Serum Albumin: Robust Blocking Agent for Enhanced Performance in Optical-Fiber Based DNA Sensing.

    Science.gov (United States)

    Wang, Ruoyu; Zhou, Xiaohong; Zhu, Xiyu; Yang, Chao; Liu, Lanhua; Shi, Hanchang

    2017-02-24

    Surface blocking is a well-known process for reducing unwanted nonspecific adsorption in sensor fabrication, especially important in the emerging field where DNA/RNA applied. Bovine serum albumin (BSA) is one of the most popular blocking agents with an isoelectric point at pH 4.6. Although it is widely recognized that the adsorption of a blocking agent is strongly affected by its net charge and the maximum adsorption is often observed under its isoelectric form, BSA has long been perfunctorily used for blocking merely in neutral solution, showing poor blocking performances in the optical-fiber evanescent wave (OFEW) based sensing toward DNA target. To meet this challenge, we first put forward the view that isoelectric BSA (iep-BSA) has the best blocking performance and use an OFEW sensor platform to demonstrate this concept. An optical-fiber was covalently modified with amino-DNA, and further coupled with the optical system to detect fluorophore labeled complementary DNA within the evanescent field. A dramatic improvement in the reusability of this DNA modified sensing surface was achieved with 120 stable detection cycles, which ensured accurate quantitative bioassay. As expected, the iep-BSA blocked OFEW system showed enhanced sensing performance toward target DNA with a detection limit of 125 pM. To the best of our knowledge, this is the highest number of regeneration cycles ever reported for a DNA immobilized optical-fiber surface. This study can also serve as a good reference and provide important implications for developing similar DNA-directed surface biosensors.

  9. Comparison between two estradiol-progesterone based protocols for timed artificial insemination in blocks in lactating Nelore cows.

    Science.gov (United States)

    Pfeifer, L F M; Castro, N A; Neves, P M A; Cestaro, J P; Schneider, A

    2017-06-01

    The aim of this study was to compare the use of artificial insemination in time blocks (Artificial Insemination Blocks, AIB) using an 8 and 9 d estradiol-progesterone based protocol. In this experiment, lactating Nelore cows (n=253) were subjected to two estradiol-progesterone based TAI protocols. On the morning of Day 10 (8d group, n=124) or Day 11 (9d group, n=129), cows were examined by ultrasonography to evaluate the diameter of the preovulatory follicle and were inseminated once at one of the following time points, according to the diameter of the pre-ovulatory follicle (POF): Block 0 (POF≥15mm, TAI 0h after conventional TAI), Block 1 (POF 13.0-14.9mm, TAI 6h later), Block 2 (POF 10.1-12.9mm, TAI 24h later), and Block 3 (POF≤10.0mm, TAI 30h later). The pregnancy per AI (P/AI) did not differ between 8d and 9d groups (P>0.05). Considering only multiparous cows, however, P/AI tended to be greater in the 8d (64.1%) than in the 9d group (49.3%; P=0.08). Cows from the 9d group tended to have a larger POF than cows from the 8d group (P=0.07). In conclusion, these results provide evidence that there is no difference between 8d or 9d protocols when using the AIB technique. Use of the 8d estradiol-progesterone based protocol, however, tended to increase pregnancy in multiparous cows. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Chain end distribution of block copolymer in two-dimensional microphase-separated structure studied by scanning near-field optical microscopy.

    Science.gov (United States)

    Sekine, Ryojun; Aoki, Hiroyuki; Ito, Shinzaburo

    2009-10-01

    The chain end distribution of a block copolymer in a two-dimensional microphase-separated structure was studied by scanning near-field optical microscopy (SNOM). In the monolayer of poly(octadecyl methacrylate)-block-poly(isobutyl methacrylate) (PODMA-b-PiBMA), the free end of the PiBMA subchain was directly observed by SNOM, and the spatial distributions of the whole block and the chain end are examined and compared with the convolution of the point spread function of the microscope and distribution function of the model structures. It was found that the chain end distribution of the block copolymer confined in two dimensions has a peak near the domain center, being concentrated in the narrower region, as compared with three-dimensional systems.

  11. A controlled release system for proteins based on poly(ether ester) block-copolymers: polymer network characterization

    NARCIS (Netherlands)

    Bezemer, J.M.; Grijpma, Dirk W.; Dijkstra, Pieter J.; van Blitterswijk, Clemens; Feijen, Jan

    1999-01-01

    The properties of a series of multiblock copolymers, based on hydrophilic poly(ethylene glycol) (PEG) and hydrophobic poly(butylene terephthalate) (PBT) blocks were investigated with respect to their application as a matrix for controlled release of proteins. The degree of swelling, Q, of the

  12. I Scratch and Sense but Can I Program? An Investigation of Learning with a Block Based Programming Language

    Science.gov (United States)

    Simpkins, N. K.

    2014-01-01

    This article reports an investigation into undergraduate student experiences and views of a visual or "blocks" based programming language and its environment. An additional and central aspect of this enquiry is to substantiate the perceived degree of transferability of programming skills learnt within the visual environment to a typical…

  13. Improving IVUS palpography by incorporation of motion compensation based on block matching and optical flow.

    Science.gov (United States)

    Danilouchkine, Mikhail G; Mastik, Frits; van der Steen, Antonius F W

    2008-11-01

    Intravascular ultrasound (IVUS) strain imaging of the luminal layer in coronary arteries, coined as IVUS palpography, utilizes conventional radio frequency (RF) signals acquired at 2 different levels of a compressional load. The signals are cross-correlated to obtain the microscopic tissue displacements, which can be directly translated into local strain of the vessel wall. However, (apparent) tissue motion and nonuniform deformation of the vessel wall, due to catheter wiggling, reduce signal correlation and result in invalid strain estimates. Implications of probe motion were studied on the tissue-mimicking phantom. The measured circumferential tissue displacement and level of the speckle decorrelation amounted to 12 degrees and 0.58, respectively, for the catheter displacement of 456 microm. To compensate for the motion artifacts in IVUS palpography, a novel method based on the feature-based scale-space optical flow (OF), and classical block matching (BM) algorithm, were employed. The computed OF vector and BM displacement fields quantify the amount of local tissue misalignment in consecutive frames. Subsequently, the extracted circumferential displacements are used to realign the signals before strain computation. Motion compensation reduces the RF signal decorrelation and increases the number of valid strain estimates. The advantage of applying the motion correction in IVUS palpography was demonstrated in a midscale validation study on 14 in vivo pullbacks. Both methods substantially increase the number of valid strain estimates in the partial and compounded palpograms. Mean relative improvement in the number of valid strain estimates with motion compensation in comparison to one without motion compensation amounts to 28% and 14%, respectively. Implementation of motion compensation methods boosts the diagnostic value of IVUS palpography.

  14. THE OPTIMIZATION OF TECHNOLOGICAL MINING PARAMETERS IN QUARRY FOR DIMENSION STONE BLOCKS QUALITY IMPROVEMENT BASED ON PHOTOGRAMMETRIC TECHNIQUES OF MEASUREMENT

    Directory of Open Access Journals (Sweden)

    Ruslan Sobolevskyi

    2018-01-01

    Full Text Available This research focuses on patterns of change in the dimension stone commodity blocks quality production on previously identifi ed and measured geometrical parameters of natural cracks, modelling and planning out the fi nal dimension of stone products and fi nished products based on the proposed digital photogrammetric techniques. The optimal parameters of surveying are investigated and the infl uence of surveying distance to length and crack area is estimated. Rational technological parameters of dimension stone blocks production are taken into account.

  15. Speechlessness in Gilles de la Tourette Syndrome: Cannabis-Based Medicines Improve Severe Vocal Blocking Tics in Two Patients.

    Science.gov (United States)

    Jakubovski, Ewgeni; Müller-Vahl, Kirsten

    2017-08-10

    We report the cases of two young German male patients with treatment-resistant Tourette syndrome (TS), who suffer from incapacitating stuttering-like speech disfluencies caused by vocal blocking tics and palilalia. Case 1: a 19-year old patient received medical cannabis at a dose of 1 × 0.1 g cannabis daily. Case 2: a 16-year old patient initially received dronabinol at a maximum dose of 22.4-33.6 mg daily. Both treatments provided significant symptom improvement of vocal blocking tics as well as of comorbid conditions and were well tolerated. Thus, cannabis-based medicine appears to be effective in treatment-resistant TS patients with vocal blocking tics.

  16. Building Block Approach' for Structural Analysis of Thermoplastic Composite Components for Automotive Applications

    Science.gov (United States)

    Carello, M.; Amirth, N.; Airale, A. G.; Monti, M.; Romeo, A.

    2017-12-01

    Advanced thermoplastic prepreg composite materials stand out with regard to their ability to allow complex designs with high specific strength and stiffness. This makes them an excellent choice for lightweight automotive components to reduce mass and increase fuel efficiency, while maintaining the functionality of traditional thermosetting prepreg (and mechanical characteristics) and with a production cycle time and recyclability suited to mass production manufacturing. Currently, the aerospace and automotive sectors struggle to carry out accurate Finite Elements (FE) component analyses and in some cases are unable to validate the obtained results. In this study, structural Finite Elements Analysis (FEA) has been done on a thermoplastic fiber reinforced component designed and manufactured through an integrated injection molding process, which consists in thermoforming the prepreg laminate and overmolding the other parts. This process is usually referred to as hybrid molding, and has the provision to reinforce the zones subjected to additional stresses with thermoformed themoplastic prepreg as required and overmolded with a shortfiber thermoplastic resin in single process. This paper aims to establish an accurate predictive model on a rational basis and an innovative methodology for the structural analysis of thermoplastic composite components by comparison with the experimental tests results.

  17. The structure and function of glutamate receptors: Mg2+ block to X-ray diffraction.

    Science.gov (United States)

    Mayer, Mark L

    2017-01-01

    Experiments on the action of glutamate on mammalian and amphibian nervous systems started back in the 1950s but decades passed before it became widely accepted that glutamate was the major excitatory neurotransmitter in the CNS. The pace of research greatly accelerated in the 1980s when selective ligands that identified glutamate receptor subtypes became widely available, and voltage clamp techniques, coupled with rapid perfusion, began to resolve the unique functional properties of what cloning subsequently revealed to be a large family of receptors with numerous subtypes. More recently the power of X-ray crystallography and cryo-EM has been applied to the study of glutamate receptors, revealing their atomic structures, and the conformational changes that underlie their gating. In this review I summarize the history of this field, viewed through the lens of a career in which I spent 3 decades working on the structure and function of glutamate receptor ion channels. This article is part of the Special Issue entitled 'Ionotropic glutamate receptors'. Published by Elsevier Ltd.

  18. The influence of middle B-block polydispersity on the molecular configurations and lamellar structure characteristics of lamella-forming ABA triblock copolymers

    Science.gov (United States)

    Li, Y.; Qian, H. J.; Lu, Z. Y.

    2013-09-01

    A recent experimental study (Widin J. M., Schmitt A. K., Schmitt A. L., Im K. and Mahanthappa M. K., J. Am. Chem. Soc., 134 (2012) 3834) showed that polydispersity of the middle B-block has large effects on the phase behavior of ABA triblock copolymers. It is well known that the intriguing properties of ordered structures are associated with the molecular configurations and their distribution at microscale. By using a comprehensive dissipative particle dynamics (DPD) simulation method, we study the effect of middle B-block polydispersity of lamella-forming ABA triblock copolymers on the molecular configurations and the characteristics of lamellar structures. The results show that molecules with short B-blocks in a polydisperse system mainly adopt a looped configuration and preferably locate at the A/B interfaces. On the contrary, the long blocks can adopt either looped or bridged configurations with an equal probability. The bridging fraction of triblock copolymers will decrease with the increase of middle B-block polydispersity, which is due to the fact that there will be more short triblock copolymers adopting looped configurations. Such triblock copolymers with short B-blocks accumulating at the interface region can act as compatibilizers and reduce the interfacial free energy. On the other hand, the domain spacing is mainly determined by the long blocks filling in the domain center. With an increase in middle B-block polydispersity, the domain spacing will expand due to the molecular stretching of the long blocks in the domain center as well as to the reduction in interfacial free energy.

  19. Incomplete split-plot designs based on alpha-designs: a compromise between traditional split-plot designs and randomised complete block design

    DEFF Research Database (Denmark)

    Kristensen, Kristian

    2012-01-01

    The paper shows how the α-design (also known as generalised lattice) may be used for constructing incomplete split-plot designs and describes four different methods (A, B, C and D) of construction. Intra-block efficiency factors and theoretical considerations are used to compare the methods. Based...... of data. The three types were simulated data with known covariance structure, data from uniformity trials and data from actual trials using incomplete split-plot designs for comparing cereal varieties under different growing conditions. It is concluded that the incomplete split-plot designs may be a good...

  20. Structure and stereochemistry in f-block complexes of high co-ordination number

    International Nuclear Information System (INIS)

    Kepert, D.L.; Patrick, J.M.; White, A.H.

    1983-01-01

    The crystal structure of [Usup(IV)(PhCOCHCOPh)4- has been determined at 295 K from X-ray diffraction data refined by least squares to a residual of 0.042 for 2 257 'observed' reflections. Crystals are orthorhombic, space group Pccn, with unit-cell dimensions a = 10.323(8), b = 20.172(15), c = 23.65(2) A, and Z = 4; they are isostructural with the previously studied cerium analogue, the eight-co-ordinate uranium atom lying on a crystallographic two-fold axis, with U - O ranging from 2.323(7) to 2.370(6) A. For the cerium analogue, a = 10.29(1), b = 20.07(3), and c = 23.42(4) A; R = 0.043 for 1 817 'observed' reflections. The corresponding Ce - O distances lie between 2.291(7) and 2.348(6) A. The stereochemistries of these complexes are close to square antiprismatic with the bidentate ligands spanning opposite square faces, as predicted by electron-pair repulsion theory. (author)

  1. Differentiation of foot-and-mouth disease virus infected animals from vaccinated animals using a blocking ELISA based on baculovirus expressed FMDV 3ABC antigen and a 3ABC monoclonal antibody

    DEFF Research Database (Denmark)

    Sørensen, K.J.; de Stricker, K.; Dyrting, K.C.

    2005-01-01

    A blocking ELISA that differentiated foot-and-mouth disease virus (FMDV) infected animals from vaccinated animals was developed which uses baculovirus expressed FMDV 3ABC non-structural protein as antigen and monoclonal antibody against FMDV 3ABC non-structural protein as capture and detector...... and sheep collected after experimental or natural infection. The blocking ELISA based on recombinant FMDV 3ABC antigen and a monoclonal antibody to 3ABC is a promising tool for FMD control and eradication campaigns, where vaccination has been carried out....

  2. Brain disorders? Not really… Why network structures block reductionism in psychopathology research.

    Science.gov (United States)

    Borsboom, Denny; Cramer, Angélique; Kalis, Annemarie

    2018-01-24

    In the past decades, reductionism has dominated both research directions and funding policies in clinical psychology and psychiatry. However, the intense search for the biological basis of mental disorders has not resulted in conclusive reductionist explanations of psychopathology. Recently, network models have been proposed as an alternative framework for the analysis of mental disorders, in which mental disorders arise from the causal interplay between symptoms. In this paper, we show that this conceptualization can help understand why reductionist approaches in psychiatry and clinical psychology are on the wrong track. First, symptom networks preclude the identification of a common cause of symptomatology with a neurobiological condition, because in symptom networks there is no such common cause. Second, symptom network relations depend on the content of mental states and as such feature intentionality. Third, the strength of network relations is highly likely to partially depend on cultural and historical contexts as well as external mechanisms in the environment. Taken together, these properties suggest that, if mental disorders are indeed networks of causally related symptoms, reductionist accounts cannot achieve the level of success associated with reductionist disease models in modern medicine. As an alternative strategy, we propose to interpret network structures in terms of D. C. Dennett's (1987) notion of real patterns, and suggest that, instead of being reducible to a biological basis, mental disorders feature biological and psychological factors that are deeply intertwined in feedback loops. This suggests that neither psychological nor biological levels can claim causal or explanatory priority, and that a holistic research strategy is necessary for progress in the study of mental disorders.

  3. Analyzing block placement errors in SADP patterning

    Science.gov (United States)

    Kobayashi, Shinji; Okada, Soichiro; Shimura, Satoru; Nafus, Kathleen; Fonseca, Carlos; Demand, Marc; Biesemans, Serge; Versluijs, Janko; Ercken, Monique; Foubert, Philippe; Miyazaki, Shinobu

    2016-03-01

    We discuss edge placement errors (EPE) for multi-patterning of Mx critical layers using ArF lithography. Specific focus is placed on the block formation part of the process. While plenty of literature characterization data exist on spacer formation, only limited published data is available on block processes. We analyze the accuracy of placing blocks relative to narrow spacers. Many publications calculate EPE assuming Gaussian distributions for key process variations contributing to EPE. For practical reasons, each contributor is measured on dedicated test structures. In this work, we complement such analysis and directly measure the EPE in product. We perform high density sampling of blocks using CDSEM images and analyze all feature edges of interest. We find that block placement errors can be very different depending on their local design context. Specifically we report on 2 block populations (further called block A and B) which have a 4x different standard deviation. We attribute this to differences in local topography (spacer shape) and interaction with the plasma-etch process design. Block A (on top of the `core space' S1) has excellent EPE uniformity of ~1 nm while block B (on top of `gap space' S2) has degraded EPE control of ~4 nm. Finally, we suggest that the SOC etch process is at the origin on positioning blocks accurately on slim spacers, helping the manufacturability of spacer-based patterning techniques, and helping its extension toward the 5nm node.

  4. Increased luminance of MEH-PPV and PFO based PLEDs by using salmon DNA as an electron blocking layer

    Energy Technology Data Exchange (ETDEWEB)

    Madhwal, Devinder, E-mail: devindermadhwal@gmail.co [Material Science Laboratory, Department of Electronic Science, University of Delhi South campus, Benito Juarez Road, New Delhi-110021 (India); Rait, S.S.; Verma, A.; Kumar, Amit; Bhatnagar, P.K.; Mathur, P.C. [Material Science Laboratory, Department of Electronic Science, University of Delhi South campus, Benito Juarez Road, New Delhi-110021 (India); Onoda, M. [Department of Electrical Engineering and Computer Science, University of Hyogo, Himeji (Japan)

    2010-02-15

    The effect of salmon DNA-CTMA as an electron blocking layer (EBL) has been examined on the performance of MEH-PPV and PFO-based light emitting diodes. Though the turn-on voltage increases with incorporation of EBL, a significant increase in luminance and luminous efficiency for both the devices is observed. The EBL improves the device performance by blocking electrons at the EBL-polymer interface, thereby increasing the recombination probability of electrons and holes. The luminance of the MEH-PPV based Bio-LED increases to 100 cd/m{sup 2} from 30 cd/m{sup 2} while a corresponding increase for the PFO based LED is to 160 cd/m{sup 2} from 80 cd/m{sup 2} with and without EBL, respectively.

  5. Structural Bases of Postresuscitative Heart Failure

    Directory of Open Access Journals (Sweden)

    V. T. Dolgikh

    2005-01-01

    Full Text Available An experiment on 106 non-inbred male albino rats undergone 4-minute clinical death from acute blood loss has revealed that the first three days after resuscitation are marked by a concomitance of vascular disorders and cardiomyocytic dystrophic changes, the leading role being played by sludge, stasis, thrombosis, increased vascular permeability, perivascular edema, and hemorrhages. Cardiomyocytic destruction (various contractures, block-like myofibrillolysis, myocytoly-sis is a structural basis of postresuscitative heart failure. Three days later the heart displayed concomitant processes of recovery and damage. Three types of cardiac morphological changes have been identified in relation to the ratio of these processes.

  6. Using LEGO Blocks for Technology-Mediated Task-Based English Language Learning

    Science.gov (United States)

    Gadomska, Agnieszka

    2015-01-01

    LEGO blocks have been played with by generations of children worldwide since the 1950s. It is undeniable that they boost creativity, eye-hand coordination, focus, planning, problem solving and many other skills. LEGO bricks have been also used by educators across the curricula as they are extremely motivating and engaging and, in effect, make…

  7. Synthesis of highly sulfonated polystyrene-based block copolymers soluble in tetrahydrofuran

    Czech Academy of Sciences Publication Activity Database

    Janata, Miroslav; Kůdela, Vlastimil; Gromadzki, D.; Štěpánek, Petr; Nallet, F.; Diat, O.; Vlček, Petr; Toman, Luděk

    55, - (2006), 1-12 ISSN 1618-7229 R&D Projects: GA ČR GESON/03/E001 Institutional research plan: CEZ:AV0Z40500505 Keywords : polystyrene-block-hydrogenated polyisoprene * sulfonation * acetyl sulfate Subject RIV: CD - Macromolecular Chemistry Impact factor: 0.934, year: 2006 www.e-polymers.org

  8. Implementation of the equation of radiative transfer on block-structured grids for modeling light propagation in tissue

    Science.gov (United States)

    Montejo, Ludguier D.; Klose, Alexander D.; Hielscher, Andreas H.

    2010-01-01

    We present the first algorithm for solving the equation of radiative transfer (ERT) in the frequency domain (FD) on three-dimensional block-structured Cartesian grids (BSG). This algorithm allows for accurate modeling of light propagation in media of arbitrary shape with air-tissue refractive index mismatch at the boundary at increased speed compared to currently available structured grid algorithms. To accurately model arbitrarily shaped geometries the algorithm generates BSGs that are finely discretized only near physical boundaries and therefore less dense than fine grids. We discretize the FD-ERT using a combination of the upwind-step method and the discrete ordinates (SN) approximation. The source iteration technique is used to obtain the solution. We implement a first order interpolation scheme when traversing between coarse and fine grid regions. Effects of geometry and optical parameters on algorithm performance are evaluated using numerical phantoms (circular, cylindrical, and arbitrary shape) and varying the absorption and scattering coefficients, modulation frequency, and refractive index. The solution on a 3-level BSG is obtained up to 4.2 times faster than the solution on a single fine grid, with minimal increase in numerical error (less than 5%). PMID:21258514

  9. Population Blocks.

    Science.gov (United States)

    Smith, Martin H.

    1992-01-01

    Describes an educational game called "Population Blocks" that is designed to illustrate the concept of exponential growth of the human population and some potential effects of overpopulation. The game material consists of wooden blocks; 18 blocks are painted green (representing land), 7 are painted blue (representing water); and the remaining…

  10. Identification of Plate Blocks Based on a Cluster Analysis of GNSS Data in the Angular Velocity Space

    Science.gov (United States)

    Takahashi, A.; Okazaki, T.; Takeuchi, K.; Iwata, T.; Fukahata, Y.

    2016-12-01

    The motion of a rigid plate on a sphere is expressed as rotation around an axis. Recently, statistical approaches were proposed to identify boundaries of crustal blocks from observed GNSS data. Simpson et al. (2012) showed the advantage of clustering algorithm to distinguish block boundaries. Savage and Simpson (2013) extended the study by adding an iterative algorithm to take account of the effects of a sphere. These studies successfully showed a way to identify block structures in the West Coast of the U.S.However, it is still difficult to apply the methods to global GNSS data so as to identify plate blocks. So, we developed a method to tackle this problem. First, we formulated the relationship among the geographical location of the GNSS station, observed velocity at the GNSS station, and candidates of the Euler pole. The relationship shows that the candidates of the Euler pole are expressed as a straight line in the angular velocity space, because the cross product of an Euler pole vector and a position vector of a GNSS station should be an observed velocity vector. We can expect that lines that correspond to GNSS data crosses at a point in the angular velocity space as long as these data belong to the same crustal block. We used an octree algorithm and graph clustering algorithm to spot crossing points. Each cross point represents a cluster, namely a crustal block.In order to assess the validity of our method, we applied it to GNSS data in the West Coast of U.S. where, four segments were identified in Simpson et al. (2012), and we obtained the same result as them. We confirmed that our new formulation reduces to the existing formulation in the velocity space when the scale of a clustering region is much smaller than the entire Earth.For application to global scale, we performed a numerical experiment. We deployed 360 observation stations on the earth mostly uniformly and calculated velocities at stations from six imaginary Euler poles. We translated calculated

  11. Modified Three-Step Search Block Matching Motion Estimation and Weighted Finite Automata based Fractal Video Compression

    Directory of Open Access Journals (Sweden)

    Shailesh Kamble

    2017-08-01

    Full Text Available The major challenge with fractal image/video coding technique is that, it requires more encoding time. Therefore, how to reduce the encoding time is the research component remains in the fractal coding. Block matching motion estimation algorithms are used, to reduce the computations performed in the process of encoding. The objective of the proposed work is to develop an approach for video coding using modified three step search (MTSS block matching algorithm and weighted finite automata (WFA coding with a specific focus on reducing the encoding time. The MTSS block matching algorithm are used for computing motion vectors between the two frames i.e. displacement of pixels and WFA is used for the coding as it behaves like the Fractal Coding (FC. WFA represents an image (frame or motion compensated prediction error based on the idea of fractal that the image has self-similarity in itself. The self-similarity is sought from the symmetry of an image, so the encoding algorithm divides an image into multi-levels of quad-tree segmentations and creates an automaton from the sub-images. The proposed MTSS block matching algorithm is based on the combination of rectangular and hexagonal search pattern and compared with the existing New Three-Step Search (NTSS, Three-Step Search (TSS, and Efficient Three-Step Search (ETSS block matching estimation algorithm. The performance of the proposed MTSS block matching algorithm is evaluated on the basis of performance evaluation parameters i.e. mean absolute difference (MAD and average search points required per frame. Mean of absolute difference (MAD distortion function is used as the block distortion measure (BDM. Finally, developed approaches namely, MTSS and WFA, MTSS and FC, and Plane FC (applied on every frame are compared with each other. The experimentations are carried out on the standard uncompressed video databases, namely, akiyo, bus, mobile, suzie, traffic, football, soccer, ice etc. Developed

  12. Verification of a pencil beam based treatment planning system: output factors for open photon beams shaped with MLC or blocks

    International Nuclear Information System (INIS)

    Hansson, H.

    1999-01-01

    The accuracy of monitor unit calculations from a pencil beam based, three-dimensional treatment planning system (3D TPS) has been evaluated for open irregularly shaped photon fields. The dose per monitor unit was measured in water and in air for x-ray beam qualities from 6 to 15 MV. The fields were shaped either with a multileaf collimator (MLC) or with customized alloy blocks. Calculations from the 3D TPS were compared with measurements. The agreement between calculated and measured dose per monitor unit depended on field size and the amount of blocking and was within 3% for the MLC-shaped fields. The deviation could be traced to limitations in head scatter modelling for the MLC. For fields shaped with alloy blocks, the dose per monitor unit was calculated to be within 1.6% of measured values for all fields studied. The measured and calculated relative phantom scatter for fields with the same equivalent field size were identical for MLC and alloy shaped fields. These results indicate that the accuracy in the TPS calculations for open irregular fields, shaped with MLC or blocks, is satisfactory for clinical situations. (author)

  13. Nanoporous materials from stable and metastable structures of 1,2-PB-b-PDMS block copolymers

    DEFF Research Database (Denmark)

    Schulte, Lars; Grydgaard, Anne; Jakobsen, Mathilde R.

    2011-01-01

    Experimental procedures used at the preparation and characterization stages of nanoporous materials (NPM) from 1,2-polybutadiene-b-polydimethylsiloxane (1,2-PB-b-PDMS) block copolymers are presented. The NPM were obtained from self-assembled block copolymers after firstly cross-linking 1,2-PB (the...... matrix component) and secondly degrading PDMS (the expendable component). Depending on the temperature of the cross-linking reaction different morphologies can be ‘frozen’ from the same block copolymer. Starting with a block copolymer precursor of lamellar morphology at room temperature, the gyroid...

  14. A phantom study of the accuracy of CT, MR and PET image registrations with a block matching-based algorithm.

    Science.gov (United States)

    Isambert, A; Bonniaud, G; Lavielle, F; Malandain, G; Lefkopoulos, D

    2008-12-01

    The aim of the present study was to quantitatively assess the performance of a block matching-based automatic registration algorithm integrated within the commercial treatment planning system designated ISOgray from Dosisoft. The accuracy of the process was evaluated by a phantom study on computed tomography (CT), magnetic resonance (MR) and positron emission tomography (PET) images. Two phantoms were used to carry out this study: the cylindrical Jaszczak phantom and the anthropomorphic Liqui-Phil Head Phantom (the Phantom Laboratory), containing fillable spheres. External fiducial markers were used to quantify the accuracy of 41 CT/CT, MR/CT and PET/CT automatic registrations with images of the rotated and tilted phantoms. The study first showed that a cylindrical phantom was not adapted for the evaluation of the performance of a block matching-based registration software. Secondly, the Liqui-Phil Head Phantom study showed that the algorithm was able to perform automatic registrations of CT/CT and MR/CT images with differences of up to 40 degrees in phantom rotation and of up to 20-30 degrees for PET/CT with accuracy below the image voxel size. The study showed that the block matching-based automatic registration software under investigation was robust, reliable and yielded very satisfactory results. This phantom-based test can be integrated into a periodical quality assurance process and used for any commissioning of image registration software for radiation therapy.

  15. Comparison of sequence-based and structure-based phylogenetic ...

    Indian Academy of Sciences (India)

    Prakash

    Sequence-based and structure-based phylogeny. 85. J. Biosci. 32(1), January 2007 dispersion is independent of phylogenetic tree construction algorithms. 3. ... two groups only. 3.1 Families with high correlation between sequence- based and structure-based phylogenetic trees. There are 27 families with considerably high ...

  16. Substantiation of the Fault-Block Structure for Effective Additional Exploration and Development of the West-Kommunarsky Field

    Directory of Open Access Journals (Sweden)

    M.A. Lobusev

    2017-08-01

    Full Text Available While the seismic exploration and methodological geological interpretation of geological data for drilling various wells and other types of research are improved for a significant part of the fields being developed in the Samara Region, the reliability of the structure of geological and recoverable oil and gas reserves increases. The complication of the structure and multiple recalculations of reserves at a number of fields are due to the introduction into the development of undiscovered to the required conditions of complex geological fields and licensed areas. The example of the West-Kommunarsky field shows how its geological structure becomes more complex as its study becomes more extensive. Thus, the oil reservoir in the Lower Paschian sediments, according to the created integrated model, has horizontal positions, but with different levels of water-oil contact in adjacent blocks separated by downthrows. The justification of disjunctive dislocations, which have been planned but not tracked due to their uncertainty in seismic data and determination of their main characteristics, was performed by stratigraphic correlation of well sections using the rules of projective geometry and confirmed by other traditional methodical methods. With each new tectonic movement along the strike-slip, a near-faul fracture of rocks is formed parallel to it, as a reflection of geodynamic stresses and energy-intensive processes in the downthrows and strike-slips of rocks along the fault plane. Near-fault regular changes in the fracturing of rocks and the dependence of well productivity on their location relative to the disjunctive make it possible to predict the latitudinal reservoirs zonation in near-fault area: fractured, porous-fractured, fractured-porous and porous types. Such a dialectical process of movement towards a real model of the field ensures the reliability of revised reserves and updated technological documents for the development of fields.

  17. A comparative study of the Louisiana Graduation Exit Exam science scores and student achievement based on block, modified block, and traditional bell schedules

    Science.gov (United States)

    Buczala, Deanna Marie

    The purpose of this study was to investigate the relationships among bell schedules, GEE 21 science scores, and cumulative GPAs. Factors under consideration included teacher perspective, gender, ethnicity and students' at-risk status. The researcher collected data from the Louisiana Department of Education (LDE) targeting seven schools for three types of bell schedules---traditional, modified block, and block. From each school, the cumulative GPAs and GEF 21 science scores of up to 50 randomly selected students were analyzed. The effectiveness of different bells schedules on student achievement has resulted in conflicting data. Some educators feel that block scheduling will provide teachers with more time to engage students in higher-order thinking problems and to better engage them in the content material, thus improving student achievement overall (Gullatt, 2006). Some studies found that block scheduling provides students the opportunity to spend more time examining a subject with greater detail for a longer period of continuous time. Other studies have found that students on traditional schedules outperform block scheduled students on high stakes testing (Veal & Schreiber, 1999). Using a causal-comparative research design, the researcher examined the effect of three different bell schedules on student cumulative GPAS and GEE 21 science scores. The cumulative GPAs for the students were used to determine if there was a difference in the achievement level for students taught using different bell schedules. The GEE 21 science scores were also assessed for possible differences in learning science across various bell schedules.

  18. THE OPTIMIZATION OF TECHNOLOGICAL MINING PARAMETERS IN QUARRY FOR DIMENSION STONE BLOCKS QUALITY IMPROVEMENT BASED ON PHOTOGRAMMETRIC TECHNIQUES OF MEASUREMENT

    OpenAIRE

    Ruslan Sobolevskyi; Valentyn Korobiichuk; Volodymyr Levytskyi

    2018-01-01

    This research focuses on patterns of change in the dimension stone commodity blocks quality production on previously identifi ed and measured geometrical parameters of natural cracks, modelling and planning out the fi nal dimension of stone products and fi nished products based on the proposed digital photogrammetric techniques. The optimal parameters of surveying are investigated and the infl uence of surveying distance to length and crack area is estimated. Rational technological parameters of ...

  19. Fully Pipelined Parallel Architecture for Candidate Block and Pixel-Subsampling-Based Motion Estimation

    Directory of Open Access Journals (Sweden)

    Reeba Korah

    2008-01-01

    Full Text Available This paper presents a low power and high speed architecture for motion estimation with Candidate Block and Pixel Subsampling (CBPS Algorithm. Coarse-to-fine search approach is employed to find the motion vector so that the local minima problem is totally eliminated. Pixel subsampling is performed in the selected candidate blocks which significantly reduces computational cost with low quality degradation. The architecture developed is a fully pipelined parallel design with 9 processing elements. Two different methods are deployed to reduce the power consumption, parallel and pipelined implementation and parallel accessing to memory. For processing 30 CIF frames per second our architecture requires a clock frequency of 4.5 MHz.

  20. Synthesis of bio-based building blocks from vegetable oils: a platform chemicals approach

    Directory of Open Access Journals (Sweden)

    Desroches Myriam

    2013-01-01

    Full Text Available This review reports the synthesis of various building blocks from vegetable oils in one or two-steps syntheses. Thiol-ene coupling allows to synthesize new biobased reactants with various function and functionality with reaction conditions in agreement with green chemistry principles: it does not use neither solvent nor initiator or need simple purification step, feasible at industrial scale. Esterification and amidification were also used to insert ester or amide groups in fatty chains in order to modifiy properties of thereof synthesized polymers. Building blocks synthesized have various functions and functionality: polyols, polyacids, polyamines and dicyclocarbonates from vegetable oils and from glycerine derivatives. They were used for the synthesis of biobased polyurethanes, polyhydroxyurethanes and epoxy resins.

  1. Building Blocks: Utilizing Component-Based Software Engineering in Developing Cross-Platform Mobile Applications

    OpenAIRE

    Oskar, Andersson

    2014-01-01

    Contemporary approaches to cross-platform mobile application development, such as hybrid apps from PhoneGap and generated native apps from Xamarin, show promise in reducing development time towards Android, iOS and other platforms. At the same time, studies show that there are various problems associated with these approaches, including suffering user experiences and codebases that are difficult to maintain and test properly. In this thesis, a novel prototype framework called Building Blocks ...

  2. Temperature-induced phase transition in aqueous solutions of poly(N-isopropylacrylamide)-based block copolymer

    Czech Academy of Sciences Publication Activity Database

    Spěváček, Jiří; Konefal, Rafal; Dybal, Jiří

    2016-01-01

    Roč. 369, č. 1 (2016), s. 92-96 ISSN 1022-1360. [International IUPAC Conference on Polymer-Solvent Complexes and Intercalates /11./ - POLYSOLVAT-11. Kolkata, 27.01.2016-30.01.2016] R&D Projects: GA ČR(CZ) GA15-13853S Institutional support: RVO:61389013 Keywords : aqueous solutions * block copolymers * micelles Subject RIV: CD - Macromolecular Chemistry

  3. Double-Layer Compressive Sensing Based Efficient DOA Estimation in WSAN with Block Data Loss.

    Science.gov (United States)

    Sun, Peng; Wu, Liantao; Yu, Kai; Shao, Huajie; Wang, Zhi

    2017-07-22

    Accurate information acquisition is of vital importance for wireless sensor array network (WSAN) direction of arrival (DOA) estimation. However, due to the lossy nature of low-power wireless links, data loss, especially block data loss induced by adopting a large packet size, has a catastrophic effect on DOA estimation performance in WSAN. In this paper, we propose a double-layer compressive sensing (CS) framework to eliminate the hazards of block data loss, to achieve high accuracy and efficient DOA estimation. In addition to modeling the random packet loss during transmission as a passive CS process, an active CS procedure is introduced at each array sensor to further enhance the robustness of transmission. Furthermore, to avoid the error propagation from signal recovery to DOA estimation in conventional methods, we propose a direct DOA estimation technique under the double-layer CS framework. Leveraging a joint frequency and spatial domain sparse representation of the sensor array data, the fusion center (FC) can directly obtain the DOA estimation results according to the received data packets, skipping the phase of signal recovery. Extensive simulations demonstrate that the double-layer CS framework can eliminate the adverse effects induced by block data loss and yield a superior DOA estimation performance in WSAN.

  4. Periodic organic-organometallic microdomain structures in poly(styrene-block-ferrocenyldimethylsilane) copolymers and blends with corresponding homopolymers

    NARCIS (Netherlands)

    Lammertink, Rob G.H.; Hempenius, Mark A.; Thomas, Edwin L.; Vancso, Gyula J.

    1999-01-01

    A series of poly(styrene-block-ferrocenyldimethylsilane) copolymers (SF) with different relative molar masses of the blocks were prepared by sequential anionic polymerization. The bulk morphology of these polymers, studied by TEM and SAXS, showed well-ordered lamellar and cylindrical domains as well

  5. Distribution of lithostratigraphic units within the central block of Yucca Mountain, Nevada: A three-dimensional computer-based model, Version YMP.R2.0

    International Nuclear Information System (INIS)

    Buesch, D.C.; Nelson, J.E.; Dickerson, R.P.; Drake, R.M. II; San Juan, C.A.; Spengler, R.W.; Geslin, J.K.; Moyer, T.C.

    1996-01-01

    Yucca Mountain, Nevada is underlain by 14.0 to 11.6 Ma volcanic rocks tilted eastward 3 degree to 20 degree and cut by faults that were primarily active between 12.7 and 11.6 Ma. A three-dimensional computer-based model of the central block of the mountain consists of seven structural subblocks composed of six formations and the interstratified-bedded tuffaceous deposits. Rocks from the 12.7 Ma Tiva Canyon Tuff, which forms most of the exposed rocks on the mountain, to the 13.1 Ma Prow Pass Tuff are modeled with 13 surfaces. Modeled units represent single formations such as the Pah Canyon Tuff, grouped units such as the combination of the Yucca Mountain Tuff with the superjacent bedded tuff, and divisions of the Topopah Spring Tuff such as the crystal-poor vitrophyre interval. The model is based on data from 75 boreholes from which a structure contour map at the base of the Tiva Canyon Tuff and isochore maps for each unit are constructed to serve as primary input. Modeling consists of an iterative cycle that begins with the primary structure-contour map from which isochore values of the subjacent model unit are subtracted to produce the structure contour map on the base of the unit. This new structure contour map forms the input for another cycle of isochore subtraction to produce the next structure contour map. In this method of solids modeling, the model units are presented by surfaces (structure contour maps), and all surfaces are stored in the model. Surfaces can be converted to form volumes of model units with additional effort. This lithostratigraphic and structural model can be used for (1) storing data from, and planning future, site characterization activities, (2) preliminary geometry of units for design of Exploratory Studies Facility and potential repository, and (3) performance assessment evaluations

  6. Fragment-based approach to identify IDO1 inhibitor building blocks.

    Science.gov (United States)

    Coletti, Alice; Camponeschi, Francesca; Albini, Elisa; Greco, Francesco Antonio; Maione, Vincenzo; Custodi, Chiara; Ianni, Federica; Grohmann, Ursula; Orabona, Ciriana; Cantini, Francesca; Macchiarulo, Antonio

    2017-12-01

    Indoleamine 2,3-dioxygenase 1 (IDO1) is attracting a great deal of interest as drug target in immune-oncology being highly expressed in cancer cells and participating to the tumor immune-editing process. Although several classes of IDO1 inhibitors have been reported in literature and patent applications, only few compounds have proved optimal pharmacological profile in preclinical studies to be advanced in clinical trials. Accordingly, the quest for novel structural classes of IDO1 inhibitors is still open. In this paper, we report a fragment-based screening campaign that combines Water-LOGSY NMR experiments and microscale thermophoresis approach to identify fragments that may be helpful for the development of novel IDO1 inhibitors as therapeutic agents in immune-oncology disorders. Copyright © 2017 The Authors. Published by Elsevier Masson SAS.. All rights reserved.

  7. Linear-g-hyperbranched and cyclodextrin-based amphiphilic block copolymer as a multifunctional nanocarrier

    Directory of Open Access Journals (Sweden)

    Yamei Zhao

    2014-11-01

    Full Text Available In this paper, a novel, multifunctional polymer nanocarrier was designed to provide adequate volume for high drug loading, to afford a multiregion encapsulation ability, and to achieve controlled drug release. An amphiphilic, triblock polymer (ABC with hyperbranched polycarbonsilane (HBPCSi and β-cyclodextrin (β-CD moieties were first synthesized by the combination of a two-step reversible addition-fragmentation transfer polymerization into a pseudo-one-step hydrosilylation and quaternization reaction. The ABC then self-assembled into stable micelles with a core–shell structure in aqueous solution. These resulting micelles are multifunctional nanocarriers which possess higher drug loading capability due to the introduction of HBPCSi segments and β-CD moieties, and exhibit controlled drug release based on the diffusion release mechanism. The novel multifunctional nanocarrier may be applicable to produce highly efficient and specialized delivery systems for drugs, genes, and diagnostic agents.

  8. Model Amphiphilic Block Copolymers with Tailored Molecular Weight and Composition in PDMS-Based Films to Limit Soft Biofouling

    Energy Technology Data Exchange (ETDEWEB)

    Wenning, Brandon M. [Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Pisa 56124, Italy; Martinelli, Elisa [Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Pisa 56124, Italy; Mieszkin, Sophie [School of Biosciences, The University of Birmingham, Edgbaston, Birmingham B15 5TT, U.K.; Finlay, John A. [School of Biosciences, The University of Birmingham, Edgbaston, Birmingham B15 5TT, U.K.; Fischer, Daniel [National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States; Callow, James A. [School of Biosciences, The University of Birmingham, Edgbaston, Birmingham B15 5TT, U.K.; Callow, Maureen E. [School of Biosciences, The University of Birmingham, Edgbaston, Birmingham B15 5TT, U.K.; Leonardi, Amanda K.; Ober, Christopher K.; Galli, Giancarlo [Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Pisa 56124, Italy

    2017-05-02

    A set of controlled surface composition films was produced utilizing amphiphilic block copolymers dispersed in a cross-linked poly(dimethylsiloxane) network. These block copolymers contained oligo(ethylene glycol) (PEGMA) and fluoroalkyl (AF6) side chains in selected ratios and molecular weights to control surface chemistry including antifouling and fouling-release performance. Such properties were assessed by carrying out assays using two algae, the green macroalga Ulva linza (favors attachment to polar surfaces) and the unicellular diatom Navicula incerta (favors attachment to nonpolar surfaces). All films performed well against U. linza and exhibited high removal of attached sporelings (young plants) under an applied shear stress, with the lower molecular weight block copolymers being the best performing in the set. The composition ratios from 50:50 to 60:40 of the AF6/PEGMA side groups were shown to be more effective, with several films exhibiting spontaneous removal of the sporelings. The cells of N. incerta were also removed from several coating compositions. All films were characterized by surface techniques including captive bubble contact angle, atomic force microscopy, and near edge X-ray absorption fine structure spectroscopy to correlate surface chemistry and morphology with biological performance.

  9. Influence of Nb-doped TiO2 blocking layers as a cascading band structure for enhanced photovoltaic properties

    Science.gov (United States)

    Koo, Bon-Ryul; Oh, Dong-Hyeun; Ahn, Hyo-Jin

    2018-03-01

    Nb-doped TiO2 (Nb-TiO2) blocking layers (BLs) were developed using horizontal ultrasonic spray pyrolysis deposition (HUSPD). In order to improve the photovoltaic properties of the dye-sensitized solar cells (DSSCs), we optimized the Nb doping level of the Nb-TiO2 BLs by controlling the Nb/Ti molar ratio (0, 5, 6, and 7) of the precursor solution for HUSPD. Compared to bare TiO2 BLs, the Nb-TiO2 BLs formed a cascading band structure using the positive shift of the conduction band minimum of the Nb-TiO2 positioned between fluorine-doped tin oxide (FTO) and TiO2. This results in the increase of the potential current and the suppression of the electron recombination. Hence, it led to the improvement of the electrical conductivity, due to the increased electron concentration by the Nb doping into TiO2. Therefore, the DSSC fabricated with the Nb-TiO2 BLs at a Nb/Ti molar ratio of 6 showed superior photoconversion efficiency (∼7.50 ± 0.20%) as a result of the improved short-circuit current density. This is higher than those with the other Nb-TiO2 BLs and without BL. This improvement of the photovoltaic properties for the DSSCs can be attributed to the synergistic effects of uniform and compact BL relative to the prevention of the backward electron transport at the FTO/electrolyte interface, efficient electron transport at interfaces relative to a cascading band structure of FTO/Nb-TiO2/TiO2 multilayers and the facilitated electron transport at the BLs relative to the increased electrical conductivity of the optimized Nb-TiO2 BLs.

  10. Experimental demonstration of an OFDM based visible light communication system using inter-block precoding and superimposed pilots

    Science.gov (United States)

    Zhang, Junwei; Hong, Xuezhi; Liu, Jie; Guo, Changjian

    2018-04-01

    In this work, we investigate and experimentally demonstrate an orthogonal frequency division multiplexing (OFDM) based high speed wavelength-division multiplexed (WDM) visible light communication (VLC) system using an inter-block data precoding and superimposed pilots (DP-SP) based channel estimation (CE) scheme. The residual signal-to-pilot interference (SPI) can be eliminated by using inter-block data precoding, resulting in a significant improvement in estimated accuracy and the overall system performance compared with uncoded SP based CE scheme. We also study the power allocation/overhead problem of the training for DP-SP, uncoded SP and conventional preamble based CE schemes, from which we obtain the optimum signal-to-pilot power ratio (SPR)/overhead percentage for all above cases. Intra-symbol frequency-domain averaging (ISFA) is also adopted to further enhance the accuracy of CE. By using the DP-SP based CE scheme, aggregate data rates of 1.87-Gbit/s and 1.57-Gbit/s are experimentally demonstrated over 0.8-m and 2-m indoor free space transmission, respectively, using a commercially available red, green and blue (RGB) light emitting diode (LED) with WDM. Experimental results show that the DP-SP based CE scheme is comparable to the conventional preamble based CE scheme in term of received Q factor and data rate while entailing a much smaller overhead-size.

  11. Reliability-Based Optimization in Structural Engineering

    DEFF Research Database (Denmark)

    Enevoldsen, I.; Sørensen, John Dalsgaard

    1994-01-01

    In this paper reliability-based optimization problems in structural engineering are formulated on the basis of the classical decision theory. Several formulations are presented: Reliability-based optimal design of structural systems with component or systems reliability constraints, reliability-b...

  12. Distribution-Based Cluster Structure Selection.

    Science.gov (United States)

    Yu, Zhiwen; Zhu, Xianjun; Wong, Hau-San; You, Jane; Zhang, Jun; Han, Guoqiang

    2017-11-01

    The objective of cluster structure ensemble is to find a unified cluster structure from multiple cluster structures obtained from different datasets. Unfortunately, not all the cluster structures contribute to the unified cluster structure. This paper investigates the problem of how to select the suitable cluster structures in the ensemble which will be summarized to a more representative cluster structure. Specifically, the cluster structure is first represented by a mixture of Gaussian distributions, the parameters of which are estimated using the expectation-maximization algorithm. Then, several distribution-based distance functions are designed to evaluate the similarity between two cluster structures. Based on the similarity comparison results, we propose a new approach, which is referred to as the distribution-based cluster structure ensemble (DCSE) framework, to find the most representative unified cluster structure. We then design a new technique, the distribution-based cluster structure selection strategy (DCSSS), to select a subset of cluster structures. Finally, we propose using a distribution-based normalized hypergraph cut algorithm to generate the final result. In our experiments, a nonparametric test is adopted to evaluate the difference between DCSE and its competitors. We adopt 20 real-world datasets obtained from the University of California, Irvine and knowledge extraction based on evolutionary learning repositories, and a number of cancer gene expression profiles to evaluate the performance of the proposed methods. The experimental results show that: 1) DCSE works well on the real-world datasets and 2) DCSE based on DCSSS can further improve the performance of the algorithm.

  13. Optoelectronics using block copolymers.

    Energy Technology Data Exchange (ETDEWEB)

    Botiz, I.; Darling, S. B.; Center for Nanoscale Materials

    2010-05-01

    Block copolymers, either as semiconductors themselves or as structure directors, are emerging as a promising class of materials for understanding and controlling processes associated with both photovoltaic energy conversion and light emitting devices.

  14. Tunable Mesoporous Bragg Reflectors Based on Block-Copolymer Self-Assembly

    KAUST Repository

    Guldin, Stefan

    2011-07-06

    Mesoporous Bragg reflectors are a promising materials platform for photovoltaics, light emission, and sensing. A fast and versatile fabrication route that relies on the self-assembly of the block copolymer poly(isoprene-b-ethylene oxide) in combination with simple sol-gel chemistry is reported. The method allows extended control over porosity and pore size in the resulting inorganic material and results in high-quality optical elements. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Block cipher based on modular arithmetic and methods of information compression

    Science.gov (United States)

    Krendelev, S.; Zbitnev, N.; Shishlyannikov, D.; Gridin, D.

    2017-10-01

    The article focuses on the description of a new block cipher. Due to the heightened interest in BigData the described cipher is used to encrypt big volumes of data in cloud storage services. The main advantages of the given cipher are the ease of implementation and the possibility of probabilistic encryption. This means that the text encryption will be different when the key is the same and the data is the same. So, the strength of the encryption is improved. Additionally, the ciphered message size can be hardly predicted.

  16. Entropy-based quantification of a product’s BOM blocking effect

    Directory of Open Access Journals (Sweden)

    César Martínez-Olvera

    2016-01-01

    Full Text Available Manufacturing complexity increases as a result of product configuration, and even though different manufacturing complexity measures have been developed, none of them seem to put attention to the blocking effect a product’s bill-of-material imposes to the process flow. The following paper extends the research presented by the authors in a previous paper, where a set of entropic formulations were developed to act as an increase/decrease indicator of a manufacturing system’s performance parameters. Our findings show that the improvements to the entropic formulations provide results that are closer to the system’s performance parameters final values.

  17. Imputation of missing genotypes within LD-blocks relying on the basic coalescent and beyond: consideration of population growth and structure.

    Science.gov (United States)

    Kabisch, Maria; Hamann, Ute; Lorenzo Bermejo, Justo

    2017-10-17

    Genotypes not directly measured in genetic studies are often imputed to improve statistical power and to increase mapping resolution. The accuracy of standard imputation techniques strongly depends on the similarity of linkage disequilibrium (LD) patterns in the study and reference populations. Here we develop a novel approach for genotype imputation in low-recombination regions that relies on the coalescent and permits to explicitly account for population demographic factors. To test the new method, study and reference haplotypes were simulated and gene trees were inferred under the basic coalescent and also considering population growth and structure. The reference haplotypes that first coalesced with study haplotypes were used as templates for genotype imputation. Computer simulations were complemented with the analysis of real data. Genotype concordance rates were used to compare the accuracies of coalescent-based and standard (IMPUTE2) imputation. Simulations revealed that, in LD-blocks, imputation accuracy relying on the basic coalescent was higher and less variable than with IMPUTE2. Explicit consideration of population growth and structure, even if present, did not practically improve accuracy. The advantage of coalescent-based over standard imputation increased with the minor allele frequency and it decreased with population stratification. Results based on real data indicated that, even in low-recombination regions, further research is needed to incorporate recombination in coalescence inference, in particular for studies with genetically diverse and admixed individuals. To exploit the full potential of coalescent-based methods for the imputation of missing genotypes in genetic studies, further methodological research is needed to reduce computer time, to take into account recombination, and to implement these methods in user-friendly computer programs. Here we provide reproducible code which takes advantage of publicly available software to facilitate

  18. Structure of long human telomeric RNA (TERRA): G-quadruplexes formed by four and eight UUAGGG repeats are stable building blocks.

    Science.gov (United States)

    Martadinata, Herry; Heddi, Brahim; Lim, Kah Wai; Phan, Anh Tuân

    2011-07-26

    The discovery of long RNA transcripts of telomeric repeats (TERRA) and their potential to form G-quadruplexes stimulated studies on the possible arrangements of G-quadruplexes along TERRA. Here we performed ribonuclease protection assay to investigate the structures formed by long human TERRA. We found that G-quadruplexes comprising four and eight UUAGGG repeats were most resistant to RNase T1 digestion, presumably with the former adopting an all-parallel-stranded propeller-type conformation and the latter forming a structure with two tandemly stacked G-quadruplex subunits each containing three G-tetrad layers. Molecular dynamics simulations of eight-repeat human TERRA sequences consisting of different stacking interfaces between the two G-quadruplex subunits, i.e., 5'-5', 3'-3', 3'-5', and 5'-3', demonstrated stacking feasibility for all but the 5'-3' arrangement. A continuous stacking of the loop bases from one G-quadruplex subunit to the next was observed for the 5'-5' stacking conformation. We also put forward other possible stacking arrangements that involve more than one linker connecting the two G-quadruplex subunits. On the basis of these results, we propose a "beads-on-a-string"-like arrangement along human TERRA, whereby each bead is made up of either four or eight UUAGGG repeats in a one- or two-block G-quadruplex arrangement, respectively. © 2011 American Chemical Society

  19. Element-Free Galerkin Method Based on Block-Pulse Wavelets Integration for Solving Fourth-Order Obstacle Problem

    Directory of Open Access Journals (Sweden)

    Muhammad Azam

    2013-01-01

    Full Text Available We introduce improved element-free Galerkin method based on block pulse wavelet integration for numerical approximations to the solution of a system of fourth-order boundary-value problems associated with obstacle, unilateral, and contact problems. Moving least squares (MLS approach is used to construct shape functions with optimized weight functions and basis. Numerical results for test problems are presented in this article to elaborate the pertinent features for the proposed technique. Comparison with existing techniques shows that our proposed method based on integration technique provides better approximation at reduced computational cost.

  20. Spatial Block Codes Based on Unitary Transformations Derived from Orthonormal Polynomial Sets

    Directory of Open Access Journals (Sweden)

    Mandyam Giridhar D

    2002-01-01

    Full Text Available Recent work in the development of diversity transformations for wireless systems has produced a theoretical framework for space-time block codes. Such codes are beneficial in that they may be easily concatenated with interleaved trellis codes and yet still may be decoded separately. In this paper, a theoretical framework is provided for the generation of spatial block codes of arbitrary dimensionality through the use of orthonormal polynomial sets. While these codes cannot maximize theoretical diversity performance for given dimensionality, they still provide performance improvements over the single-antenna case. In particular, their application to closed-loop transmit diversity systems is proposed, as the bandwidth necessary for feedback using these types of codes is fixed regardless of the number of antennas used. Simulation data is provided demonstrating these types of codes′ performance under this implementation as compared not only to the single-antenna case but also to the two-antenna code derived from the Radon-Hurwitz construction.

  1. A TEACHING PROPOSAL OF PRODUCTION OF DISSERTATIVE-ARGUMENTATIVE TEXTS BASED ON THE THEORY OF SEMANTIC BLOCKS

    Directory of Open Access Journals (Sweden)

    Cláudio Primo Delanoy

    2015-12-01

    Full Text Available This paper aims to explain a teaching proposal of production of dissertative-argumentative texts, based on concepts and principles of the Theory of Argumentation within Language (ADL of Ducrot (1990, 2009, and above all in tools made available by the Theory of Semantic Blocks (TBS, Carel (1995, 2005, and Carel and Ducrot (2005. In order to do so, first, the text production proposal of Enem 2012 is analyzed, so as to find the basic semantic units of its motivational texts, which, by being associated to argumentative aspects of semantic blocks that originate those semantic units, may guide effective argumentative routes to be realized in dissertative argumentative text from semantic relations within the same block. It is verified, also, to what extent argumentative transgressive chaining are presented in argumentative essays as more convincing than the normative argumentative ones. As a result, this work may provide theoretical and methodological support for teachers that have been working directly with the teaching of reading and writing, in basic or superior education levels.

  2. A LIF scheme for HIPER application based on the combination of ultrahigh laser nonlinear force driven plasma blocks and the relativistic acceleration of ions blocks

    Science.gov (United States)

    Moustaizis, Stavros; Lalousis, Paraskevas; Hora, Heinrich

    2013-05-01

    Laser ignition of fusion (LIF) of light nuclei for fusion reactions for producing energy (LIFE) by using very powerful laser pulses with duration in the range of picoseconds is the aim of fast ignition where HiPER is one of the options. Special attention is given to the ultrahigh acceleration of plasma blocks about which option results are reported including an alternative scheme for avoiding lateral energy losses. Examples of relativistic accelerations are evaluated for HiPER and LIFE applications.

  3. Binaural noise reduction via cue-preserving MMSE filter and adaptive-blocking-based noise PSD estimation

    Science.gov (United States)

    Azarpour, Masoumeh; Enzner, Gerald

    2017-12-01

    Binaural noise reduction, with applications for instance in hearing aids, has been a very significant challenge. This task relates to the optimal utilization of the available microphone signals for the estimation of the ambient noise characteristics and for the optimal filtering algorithm to separate the desired speech from the noise. The additional requirements of low computational complexity and low latency further complicate the design. A particular challenge results from the desired reconstruction of binaural speech input with spatial cue preservation. The latter essentially diminishes the utility of multiple-input/single-output filter-and-sum techniques such as beamforming. In this paper, we propose a comprehensive and effective signal processing configuration with which most of the aforementioned criteria can be met suitably. This relates especially to the requirement of efficient online adaptive processing for noise estimation and optimal filtering while preserving the binaural cues. Regarding noise estimation, we consider three different architectures: interaural (ITF), cross-relation (CR), and principal-component (PCA) target blocking. An objective comparison with two other noise PSD estimation algorithms demonstrates the superiority of the blocking-based noise estimators, especially the CR-based and ITF-based blocking architectures. Moreover, we present a new noise reduction filter based on minimum mean-square error (MMSE), which belongs to the class of common gain filters, hence being rigorous in terms of spatial cue preservation but also efficient and competitive for the acoustic noise reduction task. A formal real-time subjective listening test procedure is also developed in this paper. The proposed listening test enables a real-time assessment of the proposed computationally efficient noise reduction algorithms in a realistic acoustic environment, e.g., considering time-varying room impulse responses and the Lombard effect. The listening test outcome

  4. Polybenzimidazole block copolymers for fuel cell: synthesis and studies of block length effects on nanophase separation, mechanical properties, and proton conductivity of PEM.

    Science.gov (United States)

    Maity, Sudhangshu; Jana, Tushar

    2014-05-14

    A series of meta-polybenzimidazole-block-para-polybenzimidazole (m-PBI-b-p-PBI), segmented block copolymers of PBI, were synthesized with various structural motifs and block lengths by condensing the diamine terminated meta-PBI (m-PBI-Am) and acid terminated para-PBI (p-PBI-Ac) oligomers. NMR studies and existence of two distinct glass transition temperatures (Tg), obtained from dynamical mechanical analysis (DMA) results, unequivocally confirmed the formation of block copolymer structure through the current polymerization methodology. Appropriate and careful selection of oligomers chain length enabled us to tailor the block length of block copolymers and also to make varieties of structural motifs. Increasingly distinct Tg peaks with higher block length of segmented block structure attributed the decrease in phase mixing between the meta-PBI and para-PBI blocks, which in turn resulted into nanophase segregated domains. The proton conductivities of proton exchange membrane (PEM) developed from phosphoric acid (PA) doped block copolymer membranes were found to be increasing substantially with increasing block length of copolymers even though PA loading of these membranes did not alter appreciably with varying block length. For example when molecular weight (Mn) of blocks were increased from 1000 to 5500 then the proton conductivities at 160 °C of resulting copolymers increased from 0.05 to 0.11 S/cm. Higher block length induced nanophase separation between the blocks by creating less morphological barrier within the block which facilitated the movement of the proton in the block and hence resulting higher proton conductivity of the PEM. The structural varieties also influenced the phase separation and proton conductivity. In comparison to meta-para random copolymers reported earlier, the current meta-para segmented block copolymers were found to be more suitable for PBI-based PEM.

  5. SU-G-BRA-02: Development of a Learning Based Block Matching Algorithm for Ultrasound Tracking in Radiotherapy

    International Nuclear Information System (INIS)

    Shepard, A; Bednarz, B

    2016-01-01

    Purpose: To develop an ultrasound learning-based tracking algorithm with the potential to provide real-time motion traces of anatomy-based fiducials that may aid in the effective delivery of external beam radiation. Methods: The algorithm was developed in Matlab R2015a and consists of two main stages: reference frame selection, and localized block matching. Immediately following frame acquisition, a normalized cross-correlation (NCC) similarity metric is used to determine a reference frame most similar to the current frame from a series of training set images that were acquired during a pretreatment scan. Segmented features in the reference frame provide the basis for the localized block matching to determine the feature locations in the current frame. The boundary points of the reference frame segmentation are used as the initial locations for the block matching and NCC is used to find the most similar block in the current frame. The best matched block locations in the current frame comprise the updated feature boundary. The algorithm was tested using five features from two sets of ultrasound patient data obtained from MICCAI 2014 CLUST. Due to the lack of a training set associated with the image sequences, the first 200 frames of the image sets were considered a valid training set for preliminary testing, and tracking was performed over the remaining frames. Results: Tracking of the five vessel features resulted in an average tracking error of 1.21 mm relative to predefined annotations. The average analysis rate was 15.7 FPS with analysis for one of the two patients reaching real-time speeds. Computations were performed on an i5-3230M at 2.60 GHz. Conclusion: Preliminary tests show tracking errors comparable with similar algorithms at close to real-time speeds. Extension of the work onto a GPU platform has the potential to achieve real-time performance, making tracking for therapy applications a feasible option. This work is partially funded by NIH grant R01CA

  6. Neurocardiology: Structure-Based Function.

    Science.gov (United States)

    Ardell, Jeffrey L; Armour, John Andrew

    2016-09-15

    Cardiac control is mediated via a series of reflex control networks involving somata in the (i) intrinsic cardiac ganglia (heart), (ii) intrathoracic extracardiac ganglia (stellate, middle cervical), (iii) superior cervical ganglia, (iv) spinal cord, (v) brainstem, and (vi) higher centers. Each of these processing centers contains afferent, efferent, and local circuit neurons, which interact locally and in an interdependent fashion with the other levels to coordinate regional cardiac electrical and mechanical indices on a beat-to-beat basis. This control system is optimized to respond to normal physiological stressors (standing, exercise, and temperature); however, it can be catastrophically disrupted by pathological events such as myocardial ischemia. In fact, it is now recognized that autonomic dysregulation is central to the evolution of heart failure and arrhythmias. Autonomic regulation therapy is an emerging modality in the management of acute and chronic cardiac pathologies. Neuromodulation-based approaches that target select nexus points of this hierarchy for cardiac control offer unique opportunities to positively affect therapeutic outcomes via improved efficacy of cardiovascular reflex control. As such, understanding the anatomical and physiological basis for such control is necessary to implement effectively novel neuromodulation therapies. © 2016 American Physiological Society. Compr Physiol 6:1635-1653, 2016. Copyright © 2016 John Wiley & Sons, Inc.

  7. Analgesic efficacy of ultrasound guided versus landmark-based bilateral superficial cervical plexus block for thyroid surgery

    Directory of Open Access Journals (Sweden)

    Rasha M. Hassan

    2017-10-01

    Full Text Available Background: The use of bilateral superficial cervical plexus block (BSCPB to provide analgesia for thyroid operations remains debatable. This study was done to assess the analgesic efficacy and safety of ultrasound (US guided or landmark-based BSCPB, performed under general anesthesia, compared to systemic narcotics in thyroid surgery. Patients and methods: A total of 69 patients ASA I and II scheduled for thyroid surgery were randomly assigned into three groups (23 patients each: Group (US received US guided BSCPB. Group (LM received landmark-based BSCPB. In both groups, the block was performed under general anesthesia and before surgery using 0.5% bupivacaine 12 ml on each side. Group (C who didn’t receive any block. We measured intra-operative hemodynamics and fentanyl requirements. We also measured postoperative analgesia within 24 h of surgery as regard: pethidine consumption, visual analogue scale (VAS pain scores and time to first rescue analgesic demand. Postoperative nausea and vomiting (PONV and other adverse events were noted as well. Results: There was a significant reduction in systolic blood pressure (SBP and heart rate (HR in groups US and LM compared with group C. Intra-operative fentanyl requirements were significantly increased in group C compared to groups US and LM. Time to first analgesic request was significantly longer in groups US and LM than in group C. Postoperative pethidine consumption and VAS scores, measured during the first postoperative day, were significantly higher in group C than groups US and LM. No significant difference was noted between the three groups regarding PONV. No other adverse events were recorded. No significant differences were noted between groups US and LM. Conclusion: BSCPB (US guided or landmark-based, performed under general anesthesia, effectively decreased peri-operative analgesic requirements in thyroid operations. However, there was no significant difference in analgesic efficacy or

  8. Morphing the feature-based multi-blocks of normative/healthy vertebral geometries to scoliosis vertebral geometries: development of personalized finite element models.

    Science.gov (United States)

    Hadagali, Prasannaah; Peters, James R; Balasubramanian, Sriram

    2018-03-12

    Personalized Finite Element (FE) models and hexahedral elements are preferred for biomechanical investigations. Feature-based multi-block methods are used to develop anatomically accurate personalized FE models with hexahedral mesh. It is tedious to manually construct multi-blocks for large number of geometries on an individual basis to develop personalized FE models. Mesh-morphing method mitigates the aforementioned tediousness in meshing personalized geometries every time, but leads to element warping and loss of geometrical data. Such issues increase in magnitude when normative spine FE model is morphed to scoliosis-affected spinal geometry. The only way to bypass the issue of hex-mesh distortion or loss of geometry as a result of morphing is to rely on manually constructing the multi-blocks for scoliosis-affected spine geometry of each individual, which is time intensive. A method to semi-automate the construction of multi-blocks on the geometry of scoliosis vertebrae from the existing multi-blocks of normative vertebrae is demonstrated in this paper. High-quality hexahedral elements were generated on the scoliosis vertebrae from the morphed multi-blocks of normative vertebrae. Time taken was 3 months to construct the multi-blocks for normative spine and less than a day for scoliosis. Efforts taken to construct multi-blocks on personalized scoliosis spinal geometries are significantly reduced by morphing existing multi-blocks.

  9. Constructing metal-based structures on nanopatterned etched silicon.

    Science.gov (United States)

    Zhang, Xiaojiang; Qiao, Yinghong; Xu, Lina; Buriak, Jillian M

    2011-06-28

    Silicon surfaces with nanoscale etched patterns were obtained using polystyrene-block-poly(4-vinylpyridine) (PS-b-P4VP) block copolymer films as templates, followed by brief immersion in HF(aq). The resulting interfaces were comprised of pseudohexagonal arrays of pits on the silicon, whose shapes depended upon the chosen silicon orientation. The top unetched face of silicon remains capped by the native oxide, and the pit interiors are terminated by Si-H(x). Selective chemical functionalization via these two chemical handles was demonstrated to be a viable approach toward building nanostructured metal oxide and metal features within these silicon pits and on the top face. Using a series of interfacial chemical reactions, including oxidation (of Si-H(x)-terminated regions), hydrosilylation, and alkoxysilane-based chemistry on silicon oxide, the growth of metal-based structures can be spatially controlled. In the first approach, titania nanobowls were grown within the etch pits, and in the second, galvanic displacement was used to produce gold nanoparticles either within the etch pits, on the top silicon face, or both.

  10. Renewable poly(δ-decalactone) based block copolymer micelles as drug delivery vehicle:in vitroandin vivoevaluation.

    Science.gov (United States)

    Bansal, Kuldeep K; Gupta, Jitendra; Rosling, Ari; Rosenholm, Jessica M

    2018-03-01

    Polymers from natural resources are attracting much attention in various fields including drug delivery as green alternatives to fossil fuel based polymers. In this quest, novel block copolymers based on renewable poly(δ-decalactone) (PDL) were evaluated for their drug delivery capabilities and compared with a fossil fuel based polymer i.e. methoxy-poly(ethylene glycol)-b-poly(ε-caprolactone) (mPEG-b-PCL). Using curcumin as a hydrophobic drug model, micelles of PDL block copolymers with different orientation i.e. AB (mPEG-b-PDL), ABA (PDL-b-PEG-b-PDL), ABC (mPEG-b-PDL-b-poly(pentadecalactone) and (mPEG-b-PCL) were prepared by nanoprecipitation method. The size, drug loading and curcumin stability studies results indicated that mPEG-b-PDL micelles was comparable to its counterpart mPEG-b-PCL micelles towards improved delivery of curcumin. Therefore, mixed micelles using these two copolymers were also evaluated to see any change in size, loading and drug release. Drug release studies proposed that sustained release can be obtained using poly(pentadecalactone) as crystalline core whereas rapid release can be achieved using amorphous PDL core. Further, mPEG-b-PDL micelles were found to be non-haemolytic, up to the concentration of 40 mg/mL. In vivo toxicity studies on rats advised low-toxic behaviour of these micelles up to 400 mg/kg dose, as evident by histopathological and biochemical analysis. In summary, it is anticipated that mPEG-b-PDL block copolymer micelles could serve as a renewable alternative for mPEG-b-PCL copolymers in drug delivery applications.

  11. Chitosan microspheres with an extracellular matrix-mimicking nanofibrous structure as cell-carrier building blocks for bottom-up cartilage tissue engineering

    Science.gov (United States)

    Zhou, Yong; Gao, Huai-Ling; Shen, Li-Li; Pan, Zhao; Mao, Li-Bo; Wu, Tao; He, Jia-Cai; Zou, Duo-Hong; Zhang, Zhi-Yuan; Yu, Shu-Hong

    2015-12-01

    Scaffolds for tissue engineering (TE) which closely mimic the physicochemical properties of the natural extracellular matrix (ECM) have been proven to advantageously favor cell attachment, proliferation, migration and new tissue formation. Recently, as a valuable alternative, a bottom-up TE approach utilizing cell-loaded micrometer-scale modular components as building blocks to reconstruct a new tissue in vitro or in vivo has been proved to demonstrate a number of desirable advantages compared with the traditional bulk scaffold based top-down TE approach. Nevertheless, micro-components with an ECM-mimicking nanofibrous structure are still very scarce and highly desirable. Chitosan (CS), an accessible natural polymer, has demonstrated appealing intrinsic properties and promising application potential for TE, especially the cartilage tissue regeneration. According to this background, we report here the fabrication of chitosan microspheres with an ECM-mimicking nanofibrous structure for the first time based on a physical gelation process. By combining this physical fabrication procedure with microfluidic technology, uniform CS microspheres (CMS) with controlled nanofibrous microstructure and tunable sizes can be facilely obtained. Especially, no potentially toxic or denaturizing chemical crosslinking agent was introduced into the products. Notably, in vitro chondrocyte culture tests revealed that enhanced cell attachment and proliferation were realized, and a macroscopic 3D geometrically shaped cartilage-like composite can be easily constructed with the nanofibrous CMS (NCMS) and chondrocytes, which demonstrate significant application potential of NCMS as the bottom-up cell-carrier components for cartilage tissue engineering.Scaffolds for tissue engineering (TE) which closely mimic the physicochemical properties of the natural extracellular matrix (ECM) have been proven to advantageously favor cell attachment, proliferation, migration and new tissue formation

  12. Reliability based Design of Coastal Structures

    DEFF Research Database (Denmark)

    Burcharth, H. F.

    2003-01-01

    Conventional design practice for coastal structures is deterministic in nature and is based on the concept of a design load which should not exceed the resistance (carrying capacity) of the structure. The design load is usually defined on a probabilistic basis as a characteristic value of the loa...

  13. Reducing Trap-Assisted Recombination in Small Organic Molecule-Based Photovoltaics by the Addition of a Conjugated Block Copolymer.

    Science.gov (United States)

    Cho, Kyuwan; Kim, Jinseck; Yoon, So Yeon; Ryu, Ka Yeon; Jang, Song-Rim; Lim, Bogyu; Kim, Kyungkon

    2018-03-01

    The performance of organic photovoltaics (OPVs) based on the small-molecule organic semiconductor p-DTS(FBTTh 2 ) 2 is greatly improved by the addition of a conjugated block copolymer composed of difluoroquinoxaline and thienopyrrolodione blocks (D130). The power conversion efficiency (PCE) of the p-DTS(FBTTh 2 ) 2 -based OPV is improved from 5.08% to 6.75% by the addition of 5 wt% D130 to the photoactive layer, which is composed of p-DTS(FBTTh 2 ) 2 and a fullerene derivative. Current-voltage and grazing incidence wide-angle X-ray scattering analyses revealed that the addition of D130 significantly reduces the trap density of the device and changes the packing orientation of p-DTS(FBTTh 2 ) 2 from mostly edge-on to partially face-on. These changes greatly improve the charge carrier mobility of the OPV, indicating that D130 is highly compatible with p-DTS(FBTTh 2 ) 2 . Furthermore, the addition of D130 improve the photostability of the OPV by reducing the burn-in loss under a light soaking intensity of 1 sun. The D130-based OPV maintained 34% of its initial PCE after a light soaking test for 858 h. In contrast, the PCE of the OPV without D130 reduced to 14% of its initial efficiency in the same time period. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. An Optimal Mean Based Block Robust Feature Extraction Method to Identify Colorectal Cancer Genes with Integrated Data.

    Science.gov (United States)

    Liu, Jian; Cheng, Yuhu; Wang, Xuesong; Zhang, Lin; Liu, Hui

    2017-08-17

    It is urgent to diagnose colorectal cancer in the early stage. Some feature genes which are important to colorectal cancer development have been identified. However, for the early stage of colorectal cancer, less is known about the identity of specific cancer genes that are associated with advanced clinical stage. In this paper, we conducted a feature extraction method named Optimal Mean based Block Robust Feature Extraction method (OMBRFE) to identify feature genes associated with advanced colorectal cancer in clinical stage by using the integrated colorectal cancer data. Firstly, based on the optimal mean and L 2,1 -norm, a novel feature extraction method called Optimal Mean based Robust Feature Extraction method (OMRFE) is proposed to identify feature genes. Then the OMBRFE method which introduces the block ideology into OMRFE method is put forward to process the colorectal cancer integrated data which includes multiple genomic data: copy number alterations, somatic mutations, methylation expression alteration, as well as gene expression changes. Experimental results demonstrate that the OMBRFE is more effective than previous methods in identifying the feature genes. Moreover, genes identified by OMBRFE are verified to be closely associated with advanced colorectal cancer in clinical stage.

  15. An Investigation of Atomic Structures Derived from X-ray Crystallography and Cryo-Electron Microscopy Using Distal Blocks of Side-Chains.

    Science.gov (United States)

    Chen, Lin; He, Jing; Sazzed, Salim; Walker, Rayshawn

    2018-03-08

    Cryo-electron microscopy (cryo-EM) is a structure determination method for large molecular complexes. As more and more atomic structures are determined using this technique, it is becoming possible to perform statistical characterization of side-chain conformations. Two data sets were involved to characterize block lengths for each of the 18 types of amino acids. One set contains 9131 structures resolved using X-ray crystallography from density maps with better than or equal to 1.5 Å resolutions, and the other contains 237 protein structures derived from cryo-EM density maps with 2-4 Å resolutions. The results show that the normalized probability density function of block lengths is similar between the X-ray data set and the cryo-EM data set for most of the residue types, but differences were observed for ARG, GLU, ILE, LYS, PHE, TRP, and TYR for which conformations with certain shorter block lengths are more likely to be observed in the cryo-EM set with 2-4 Å resolutions.

  16. "Science SQL" as a Building Block for Flexible, Standards-based Data Infrastructures

    Science.gov (United States)

    Baumann, Peter

    2016-04-01

    We have learnt to live with the pain of separating data and metadata into non-interoperable silos. For metadata, we enjoy the flexibility of databases, be they relational, graph, or some other NoSQL. Contrasting this, users still "drown in files" as an unstructured, low-level archiving paradigm. It is time to bridge this chasm which once was technologically induced, but today can be overcome. One building block towards a common re-integrated information space is to support massive multi-dimensional spatio-temporal arrays. These "datacubes" appear as sensor, image, simulation, and statistics data in all science and engineering domains, and beyond. For example, 2-D satellilte imagery, 2-D x/y/t image timeseries and x/y/z geophysical voxel data, and 4-D x/y/z/t climate data contribute to today's data deluge in the Earth sciences. Virtual observatories in the Space sciences routinely generate Petabytes of such data. Life sciences deal with microarray data, confocal microscopy, human brain data, which all fall into the same category. The ISO SQL/MDA (Multi-Dimensional Arrays) candidate standard is extending SQL with modelling and query support for n-D arrays ("datacubes") in a flexible, domain-neutral way. This heralds a new generation of services with new quality parameters, such as flexibility, ease of access, embedding into well-known user tools, and scalability mechanisms that remain completely transparent to users. Technology like the EU rasdaman ("raster data manager") Array Database system can support all of the above examples simultaneously, with one technology. This is practically proven: As of today, rasdaman is in operational use on hundreds of Terabytes of satellite image timeseries datacubes, with transparent query distribution across more than 1,000 nodes. Therefore, Array Databases offering SQL/MDA constitute a natural common building block for next-generation data infrastructures. Being initiator and editor of the standard we present principles

  17. Call Arrival Rate Prediction and Blocking Probability Estimation for Infrastructure based Mobile Cognitive Radio Personal Area Network

    Directory of Open Access Journals (Sweden)

    Neeta Nathani

    2017-08-01

    Full Text Available The Cognitive Radio usage has been estimated as non-emergency service with low volume traffic. Present work proposes an infrastructure based Cognitive Radio network and probability of success of CR traffic in licensed band. The Cognitive Radio nodes will form cluster. The cluster nodes will communicate on Industrial, Scientific and Medical band using IPv6 over Low-Power Wireless Personal Area Network based protocol from sensor to Gateway Cluster Head. For Cognitive Radio-Media Access Control protocol for Gateway to Cognitive Radio-Base Station communication, it will use vacant channels of licensed band. Standalone secondary users of Cognitive Radio Network shall be considered as a Gateway with one user. The Gateway will handle multi-channel multi radio for communication with Base Station. Cognitive Radio Network operators shall define various traffic data accumulation counters at Base Station for storing signal strength, Carrier-to-Interference and Noise Ratio, etc. parameters and record channel occupied/vacant status. The researches has been done so far using hour as interval is too long for parameters like holding time expressed in minutes and hence channel vacant/occupied status time is only probabilistically calculated. In the present work, an infrastructure based architecture has been proposed which polls channel status each minute in contrary to hourly polling of data. The Gateways of the Cognitive Radio Network shall monitor status of each Primary User periodically inside its working range and shall inform to Cognitive Radio- Base Station for preparation of minutewise database. For simulation, the occupancy data for all primary user channels were pulled in one minute interval from a live mobile network. Hourly traffic data and minutewise holding times has been analyzed to optimize the parameters of Seasonal Auto Regressive Integrated Moving Average prediction model. The blocking probability of an incoming Cognitive Radio call has been

  18. Block RAM-based architecture for real-time reconfiguration using Xilinx® FPGAs

    Directory of Open Access Journals (Sweden)

    Rikus le Roux

    2015-07-01

    Full Text Available Despite the advantages dynamic reconfiguration adds to a system, it only improves system performance if the execution time exceeds the configuration time. As a result, dynamic reconfiguration is only capable of improving the performance of quasi-static applications. In order to improve the performance of dynamic applications, researchers focus on improving the reconfiguration throughput. These approaches are mostly limited by the bus commonly used to connect the configuration controller to the memory, which contributes to the configuration time. A method proposed to ameliorate this overhead is an architecture utilizing localised block RAM (BRAM connected to the configuration controller to store the configuration bitstream. The aim of this paper is to illustrate the advantages of the proposed architecture, especially for reconfiguring real-time applications. This is done by validating the throughput of the architecture and comparing this to the maximum theoretical throughput of the internal configuration access port (ICAP. It was found that the proposed architecture is capable of reconfiguring an application within a time-frame suitable for real-time reconfiguration. The drawback of this method is that the BRAM is extremely limited and only a discrete set of configurations can be stored. This paper also proposes a method on how this can be mitigated without affecting the throughput.

  19. Neighboring block based disparity vector derivation for multiview compatible 3D-AVC

    Science.gov (United States)

    Kang, Jewon; Chen, Ying; Zhang, Li; Zhao, Xin; Karczewicz, Marta

    2013-09-01

    3D-AVC being developed under Joint Collaborative Team on 3D Video Coding (JCT-3V) significantly outperforms the Multiview Video Coding plus Depth (MVC+D) which simultaneously encodes texture views and depth views with the multiview extension of H.264/AVC (MVC). However, when the 3D-AVC is configured to support multiview compatibility in which texture views are decoded without depth information, the coding performance becomes significantly degraded. The reason is that advanced coding tools incorporated into the 3D-AVC do not perform well due to the lack of a disparity vector converted from the depth information. In this paper, we propose a disparity vector derivation method utilizing only the information of texture views. Motion information of neighboring blocks is used to determine a disparity vector for a macroblock, so that the derived disparity vector is efficiently used for the coding tools in 3D-AVC. The proposed method significantly improves a coding gain of the 3D-AVC in the multiview compatible mode about 20% BD-rate saving in the coded views and 26% BD-rate saving in the synthesized views on average.

  20. Fabrication of Completely Polymer-Based Solar Cells with p- and n-Type Semiconducting Block Copolymers with Electrically Inert Polystyrene.

    Science.gov (United States)

    Tomita, Eri; Kanehashi, Shinji; Ogino, Kenji

    2018-02-27

    It is widely recognized that fullerene derivatives show several advantages as n-type materials in photovoltaic applications. However, conventional [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) exhibits weak absorption in the visible region, and poor morphological stability, due to the facile aggregation. For further improvement of the device performance and durability, utilization of n-type polymeric materials instead of PCBM is considered to be a good way to solve the problems. In this study, we fabricated completely polymer-based solar cells utilizing p- and n-type block copolymers consisting of poly(3-hexylthiophene) (P3HT) and poly{[ N , N' -bis(2-octyldodecyl)naphthalene-1,4,5,8- bis (dicarboximide)-2,6-diyl]- alt -5,5'-(2,2'-bithiophene)} [P(NDI2OD-T2)], respectively, containing common polystyrene (PSt) inert blocks, which decreased the size of phase separated structures. Electron mobility in synthesized P(NDI2OD-T2)- b -PSt film enhanced by a factor of 8 compared with homopolymer. The root mean square roughness of the blend film of two block copolymers (12.2 nm) was decreased, compared with that of the simple homopolymers blend (18.8 nm). From the current density-voltage characteristics, it was confirmed that the introduction of PSt into both P3HT and P(NDI2OD-T2) improves short-circuit current density (1.16 to 1.73 mA cm -2 ) and power-conversion efficiency (0.24% to 0.32%). Better performance is probably due to the uniformity of the phase separation, and the enhancement of charge mobility.

  1. Fabrication of Completely Polymer-Based Solar Cells with p- and n-Type Semiconducting Block Copolymers with Electrically Inert Polystyrene

    Directory of Open Access Journals (Sweden)

    Eri Tomita

    2018-02-01

    Full Text Available It is widely recognized that fullerene derivatives show several advantages as n-type materials in photovoltaic applications. However, conventional [6,6]-phenyl-C61-butyric acid methyl ester (PCBM exhibits weak absorption in the visible region, and poor morphological stability, due to the facile aggregation. For further improvement of the device performance and durability, utilization of n-type polymeric materials instead of PCBM is considered to be a good way to solve the problems. In this study, we fabricated completely polymer-based solar cells utilizing p- and n-type block copolymers consisting of poly(3-hexylthiophene (P3HT and poly{[N,N′-bis(2-octyldodecylnaphthalene-1,4,5,8-bis(dicarboximide-2,6-diyl]-alt-5,5′-(2,2′-bithiophene} [P(NDI2OD-T2], respectively, containing common polystyrene (PSt inert blocks, which decreased the size of phase separated structures. Electron mobility in synthesized P(NDI2OD-T2-b-PSt film enhanced by a factor of 8 compared with homopolymer. The root mean square roughness of the blend film of two block copolymers (12.2 nm was decreased, compared with that of the simple homopolymers blend (18.8 nm. From the current density-voltage characteristics, it was confirmed that the introduction of PSt into both P3HT and P(NDI2OD-T2 improves short-circuit current density (1.16 to 1.73 mA cm−2 and power-conversion efficiency (0.24% to 0.32%. Better performance is probably due to the uniformity of the phase separation, and the enhancement of charge mobility.

  2. Fabrication of Completely Polymer-Based Solar Cells with p- and n-Type Semiconducting Block Copolymers with Electrically Inert Polystyrene

    Science.gov (United States)

    Tomita, Eri; Kanehashi, Shinji; Ogino, Kenji

    2018-01-01

    It is widely recognized that fullerene derivatives show several advantages as n-type materials in photovoltaic applications. However, conventional [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) exhibits weak absorption in the visible region, and poor morphological stability, due to the facile aggregation. For further improvement of the device performance and durability, utilization of n-type polymeric materials instead of PCBM is considered to be a good way to solve the problems. In this study, we fabricated completely polymer-based solar cells utilizing p- and n-type block copolymers consisting of poly(3-hexylthiophene) (P3HT) and poly{[N,N′-bis(2-octyldodecyl)naphthalene-1,4,5,8-bis(dicarboximide)-2,6-diyl]-alt-5,5′-(2,2′-bithiophene)} [P(NDI2OD-T2)], respectively, containing common polystyrene (PSt) inert blocks, which decreased the size of phase separated structures. Electron mobility in synthesized P(NDI2OD-T2)-b-PSt film enhanced by a factor of 8 compared with homopolymer. The root mean square roughness of the blend film of two block copolymers (12.2 nm) was decreased, compared with that of the simple homopolymers blend (18.8 nm). From the current density-voltage characteristics, it was confirmed that the introduction of PSt into both P3HT and P(NDI2OD-T2) improves short-circuit current density (1.16 to 1.73 mA cm−2) and power-conversion efficiency (0.24% to 0.32%). Better performance is probably due to the uniformity of the phase separation, and the enhancement of charge mobility. PMID:29495464

  3. 15 CFR 50.40 - Fee structure for statistics for city blocks in the 1980 Census of Population and Housing.

    Science.gov (United States)

    2010-01-01

    ... blocks in the 1980 Census of Population and Housing. 50.40 Section 50.40 Commerce and Foreign Trade... the 1980 Census of Population and Housing. (a) As part of the regular program of the 1980 census, the Census Bureau will publish printed reports containing certain summary population and housing statistics...

  4. Production of Polyclonal Antiobies to a Recombinant Potato Mop-top Virus Non-structural Triple Gene Block Protein l

    Czech Academy of Sciences Publication Activity Database

    Čeřovská, Noemi; Filigarová, Marie; Pečenková, Tamara

    2006-01-01

    Roč. 154, - (2006), s. 422-427 ISSN 0931-1785 R&D Projects: GA ČR GA522/04/1329 Institutional research plan: CEZ:AV0Z50380511 Keywords : Potato mop-top virus * recombinant protein * triple gene block * polyclonal antibodies Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 0.817, year: 2006

  5. STRUCTURAL SOLUTIONS AND SPECIAL FEATURES OF THE THERMAL PROTECTION ANALYSIS OF EXTERIOR WALLS OF BUILDINGS MADE OF AUTOCLAVED GAS-CONCRETE BLOCKS

    Directory of Open Access Journals (Sweden)

    Bedov Anatolij Ivanovich

    2012-10-01

    Full Text Available Relevant structural solutions, physical and mechanical characteristics, coefficients of thermal conductivity for exterior masonry walls made of autoclaved gas-concrete blocks are provided in the article. If a single-layer wall is under consideration, an autoclaved gas-concrete block is capable of performing the two principal functions of a shell structure, including the function of thermal protection and the bearing function. The functions are performed simultaneously. Therefore, the application of the above masonry material means the design development and erection of exterior walls of residential buildings noteworthy for their thermal efficiency. In the event of frameless structures, the height of the residential building in question may be up to 5 stories, while the use of a monolithic or a ready-made frame makes it possible to build high-rise buildings, and the number of stories is not limited in this case. If the average block density is equal to 400…500 kilograms per cubic meter, the designed wall thickness is to be equal to 400 mm. Its thermal resistance may be lower than the one set in the event of the per-element design of the thermal protection (Rreq = 3.41 м2 C/Watt, in Ufa, although it will meet the requirements of the applicable regulations if per-unit power consumption rate is considered.

  6. Small angle neutron scattering studies on the internal structure of poly(lactide-co-glycolide)-block-poly(ethylene glycol) nanoparticles as drug delivery vehicles.

    Science.gov (United States)

    Yang, Bin; Lowe, John P; Schweins, Ralf; Edler, Karen J

    2015-02-09

    Poly(lactide-co-glycolide)-block-poly(ethylene glycol) (PLGA-PEG) nanoparticles are commonly used as drug carriers in controlled drug release and targeting. To achieve predictable and clinically relevant volumes of drug distribution, nanoparticle size, surface charge, and especially composition and structure must be controlled. Understanding the internal structures within the particles is fundamentally important to explain differences in drug loading and variations in drug release rate. We prepared nanoparticles from ester-terminated PLGA-PEG polymers via nanoprecipitation, and studied the effects of altering the solvent-water miscibility (THF, acetone, and acetonitrile). Morphology, size, polydispersity, and ζ-potential of PLGA-PEG nanoparticles were characterized. Small angle neutron scattering measurements and fitted models revealed the internal nanoparticle structure: PLGA blocks of 7-9 nm are encapsulated inside a fairly dense PEG/water network in a fractal geometry. Particles with a larger PLGA block volume and higher PEG volume fraction in the particle interior result in greater retention of the hydrophilic anticancer drug carboplatin.

  7. Phase Structure and Properties of a Biodegradable Block Copolymer Coalesced from It's Crystalline Inclusion Compound Formed with alpha-Cyclodextrin

    Science.gov (United States)

    Shuai, Xintao; Wei, Min; Probeni, Francis; Bullions, Todd A.; Shin, I. Daniel; Tonelli, Alan E.

    2002-03-01

    A well-defined biodegradable block copolymer of poly(epsilon caprolactone) (PCL) and poly(L-lactic acid) (PLLA) was synthesized and characterized and then included as a guest in an inclusion compound (IC) formed with the host alpha-cyclodextrin (CD). The PCL-b-PLLA block copolymer was subsequently coalesced from it's CD-IC crystals by either treatment with hot water (50 C) or an aqueous amylase solution at 25 C. The coalesced PCL-b-PLLA was examined by FTIR, DSC, TGA, and WAXD and was found to be much more homogeneosly organized, with much less segregation and crystallinity of the PCL and PLLA microphases. The morpholgy, crystallization kinetics, thermal behavior, and biodegradability of the coalesced PCL-b-PLLA block copolymer was studied by comparison to similar observations made on as-synthesized PCL-b-PLLA, PCL and PLLA homopolymers, and their solution-cast blend. The PCL and PLLA blocks are found to be more intimately mixed, with less phase segregation, in the coalesced diblock copolymer, and this leads to homogeneous bulk crystallization, which is not observed for the as-synthesized diblock copolymer. The coalesced PCL-b-PLLA was also found to be more quickly biodegraded (lipase from Rhizopus arrhizus)than the as-synthesized PCL-b-PLLA or the physical blend of PCL and PLLA homopolymers. Overall, the coalescence of the inherently phase segregated diblock copolymer PCL-b-PLLA results in a small amount of compact, chain-extended PCL and PLLA crystals embedded in an amorphous phase, largely consisting of well-mixed PCL and PLLA blocks. Thus, we have demonstrated that it is possible to control the morpholgy of a biodegradable diblock copolymer, thereby significantly modifying it's properties, by coalescence from it's CD-IC crystals.

  8. Development of Universal Controller Architecture for SiC Based Power Electronic Building Blocks

    Science.gov (United States)

    2017-10-30

    To) Final Technical Report 05/01 /2015-08/1 5/2017 4. TITLE AND SUBTITLE Sa. CONTRACT NUMBER Development of Universal Controller Architecture for...NOTES 14. ABSTRACT The objective of this project was to develop a Universal Controller Architecture suitable for SiC based Power Electronic...based devices resulting in an order of magnitude reduction of the control time scales as compared to converter systems utilizing conventional IGBT based

  9. Carbon-based building blocks for alcohol dehydration membranes with disorder-enhanced water permeability

    DEFF Research Database (Denmark)

    Boffa, Vittorio; Etmimi, H.; Mallon, P.E.

    2017-01-01

    separation membranes. In this work, a humic acid-like biopolymer (HAL), extracted from organic compost with a yield of ~ 20%, was used to fabricate composite GO-HAL membranes. The HAL brings a high degree of disorder to the membrane structure, with the benefit of an increased water permeation rate. Upon......-HAL membranes promising devices for alcohol dehydration technologies....

  10. Bark polyflavonoids from Pinus radiata as functional building-blocks for polylactic acid (PLA-based green composites

    Directory of Open Access Journals (Sweden)

    D. E. Garcia

    2016-10-01

    Full Text Available Polylactic acid (PLA was melt-blended with Pinus radiata unmodified and modified (hydroxypropyled bark polyflavonoids in order to use such polyphenolic building-blocks as functional additives for envisaged applications. Rheological, morphological, molecular, thermal, and flexural properties were studied. Polyflavonoids improved blend processability in terms of short-time mixing. Furthermore, hydroxypropylated polyflavonoids improve miscibility in binary and ternary blends. Blend-composition affects crystallization-, melting-, and glass transition-temperature of PLA, as well as thermal resistance, and flexural properties of the blends. Polyflavonoids induced PLA-crystallization, and polymer-chain decomposition. Modified and unmodified bark polyflavonoids from radiata pine can be used successfully in PLA-based green composites beyond the food-packaging applications. The high compatibility between PLA and hydroxypropyled polyflavonoids highlights the potential of such phenolic derivatives for PLA-based material design.

  11. Acceleration of block-matching algorithms using a custom instruction-based paradigm on a Nios II microprocessor

    Science.gov (United States)

    González, Diego; Botella, Guillermo; García, Carlos; Prieto, Manuel; Tirado, Francisco

    2013-12-01

    This contribution focuses on the optimization of matching-based motion estimation algorithms widely used for video coding standards using an Altera custom instruction-based paradigm and a combination of synchronous dynamic random access memory (SDRAM) with on-chip memory in Nios II processors. A complete profile of the algorithms is achieved before the optimization, which locates code leaks, and afterward, creates a custom instruction set, which is then added to the specific design, enhancing the original system. As well, every possible memory combination between on-chip memory and SDRAM has been tested to achieve the best performance. The final throughput of the complete designs are shown. This manuscript outlines a low-cost system, mapped using very large scale integration technology, which accelerates software algorithms by converting them into custom hardware logic blocks and showing the best combination between on-chip memory and SDRAM for the Nios II processor.

  12. Structural analysis on a block copolymer thin film by in-situ neutron and x-ray grazing-incidence scattering techniques

    International Nuclear Information System (INIS)

    Torikai, Naoya; Yamada, Norifumi L.; Kawaguchi, Daisuke

    2011-01-01

    Structural change of a phase-separated block copolymer thin film with polystyrene (PS) and poly(2-vinylpyridine)(P2VP) in contact with different solvents was observed by in-situ neutron reflectometry using a conventional cell for a solid/liquid interface, and time evolution of phase-separated structure after a temperature jump to 200degC was observed for diblock and triblock copolymer thin films of PS and P2VP by grazing-incidence small-angle X-ray scattering (GISAXS). When PS-P2VP diblock copolymer thin film was contacted with methanol and water, the structural change was induced by penetration of small amount of the solvent into the film, and the original structure was almost recovered after drying it. Also, the diblock copolymer thin film was easily dissolved into toluene, and the original structure was never recovered after the solvent contact. After the temperature jump the lateral correlation spots were evolved with a time in the GISAXS pattern similarly for either block copolymer thin film with spherical structure, though their as-spun states were different. (author)

  13. Protein structure--based drug design.

    Science.gov (United States)

    Whittle, P J; Blundell, T L

    1994-01-01

    Design cycles will undoubtedly play an increasingly important role in drug discovery in the coming years, as the amount of structural information on protein targets continues to rise. However, the traditional method of drug discovery, based upon random screening and systematic modification of leads by medicinal chemistry techniques, will probably not be abandoned completely because it has a potentially important advantage over more structure-based methods--namely, leads identified in this way are unlikely to show a close resemblance to the natural ligand or substrate. They may, therefore, have advantages in terms of patent novelty, selectivity, or pharmacokinetic profile. However, such leads could then serve as the basis for structure-based, rational modification programs, in which their interactions with target receptors are defined (as we have described) and improved molecules are designed. A final important point to be made about structure-based design in drug discovery is that, while it can be of great use in the initial process of identifying ligands with improved affinity and selectivity in vitro, it can usually say very little about other essential aspects of the drug discovery process, e.g. the need to achieve an adequate pharmacokinetic profile and low toxicity in vivo. This observation reminds us that drug design is a multidisciplinary process, involving molecular biologists, biochemists, pharmacologists, organic chemists, crystallographers, and others. In order to be effective, therefore, structure-based design must be properly integrated into the overall discovery effort.

  14. Outcome in 212 anti-Ro/SSA-positive pregnancies and population-based incidence of congenital heart block.

    Science.gov (United States)

    Skog, Amanda; Lagnefeldt, Linda; Conner, Peter; Wahren-Herlenius, Marie; Sonesson, Sven-Erik

    2016-01-01

    We investigated the effects of maternal autoimmune disease and fetal congenital heart block (CHB) on pregnancy outcomes in anti-Ro/SSA-positive women and assessed the population-based incidence of isolated CHB. One hundred and ninety nine anti-Ro/SSA-positive pregnancies were prospectively followed at our center (2000-2013). Seven fetuses developed atrioventricular block (AVB) II-III. In this period, another 13 anti-Ro/SSA-positive pregnancies were referred for fetal bradycardia, subsequently diagnosed with AVB II-III. Cesarean section rates, gestational age, body measurements at birth, and the incidence of CHB in these 212 pregnancies were analyzed in relation to fetal atrioventricular conduction and maternal diagnosis and compared with data from the Medical Birth Registry on 352,104 pregnancies in the Stockholm County. The prevalence of maternal systemic lupus erythematosus (SLE) and primary Sjögren's syndrome and the outcomes at birth were similar in normal conduction and AVB I cases. Only 1/20 AVB II-III cases (0/7 in the surveillance group) had a mother diagnosed with SLE, compared with 73/192 in cases with normal conduction or AVB I. Excluding cases with AVB II-III, SLE mothers more frequently delivered by cesarean section (31% vs. 20%, p Ro/SSA-positive women, which has clinical relevance when counseling rheumatic patients considering pregnancy. © 2015 Nordic Federation of Societies of Obstetrics and Gynecology.

  15. Restricted lithium ion dynamics in PEO-based block copolymer electrolytes measured by high-field nuclear magnetic resonance relaxation

    Science.gov (United States)

    Huynh, Tan Vu; Messinger, Robert J.; Sarou-Kanian, Vincent; Fayon, Franck; Bouchet, Renaud; Deschamps, Michaël

    2017-10-01

    The intrinsic ionic conductivity of polyethylene oxide (PEO)-based block copolymer electrolytes is often assumed to be identical to the conductivity of the PEO homopolymer. Here, we use high-field 7Li nuclear magnetic resonance (NMR) relaxation and pulsed-field-gradient (PFG) NMR diffusion measurements to probe lithium ion dynamics over nanosecond and millisecond time scales in PEO and polystyrene (PS)-b-PEO-b-PS electrolytes containing the lithium salt LiTFSI. Variable-temperature longitudinal (T1) and transverse (T2) 7Li NMR relaxation rates were acquired at three magnetic field strengths and quantitatively analyzed for the first time at such fields, enabling us to distinguish two characteristic time scales that describe fluctuations of the 7Li nuclear electric quadrupolar interaction. Fast lithium motions [up to O (ns)] are essentially identical between the two polymer electrolytes, including sub-nanosecond vibrations and local fluctuations of the coordination polyhedra between lithium and nearby oxygen atoms. However, lithium dynamics over longer time scales [O (10 ns) and greater] are slower in the block copolymer compared to the homopolymer, as manifested experimentally by their different transverse 7Li NMR relaxation rates. Restricted dynamics and altered thermodynamic behavior of PEO chains anchored near PS domains likely explain these results.

  16. Data base on structural materials aging properties

    International Nuclear Information System (INIS)

    Oland, C.B.

    1992-01-01

    The US Nuclear Regulatory Commission has initiated a Structural Aging Program at the Oak Ridge National Laboratory to identify potential structural safety issues related to continued service of nuclear power plants and to establish criteria for evaluating and resolving these issues. One of the tasks in this program focuses on the establishment of a Structural Materials Information Center where long-term and environment-dependent properties of concretes and other structural materials are being collected and assembled into a data base. These properties will be used to evaluate the current condition of critical structural components in nuclear power plants and to estimate the future performance of these materials during the continued service period

  17. IPE data base structure and insights

    International Nuclear Information System (INIS)

    Lehner, J.; Youngblood, R.

    1994-01-01

    A data base (the open-quotes IPE Insights Data Baseclose quotes), has been developed that stores data obtained from the Individual Plant Examinations (IPEs) which licensees of nuclear power plants are conducting in response to the Nuclear Regulatory Commission's (NRC) Generic Letter GL88-20. The data base, which is a collection of linked dBase files, stores information about individual plant designs, core damage frequency, and containment performance in a uniform, structured way. This data base can be queried and used as a computational tool to derive insights regarding the plants for which data is stored. This paper sets out the objectives of the IPE Insights Data Base, describes its structure and contents, illustrates sample queries, and discusses possible future uses

  18. A block matching based approach with multiple simultaneous templates for the real-time 2D ultrasound tracking of liver vessels.

    Science.gov (United States)

    Shepard, Andrew J; Wang, Bo; Foo, Thomas K F; Bednarz, Bryan P

    2017-11-01

    The implementation of motion management techniques in radiation therapy can aid in mitigating uncertainties and reducing margins. For motion management to be effective, it is necessary to track key structures both accurately and at a real-time speed. Therefore, the focus of this work was to develop a 2D algorithm for the real-time tracking of ultrasound features to aid in radiation therapy motion management. The developed algorithm utilized a similarity measure-based block matching algorithm incorporating training methods and multiple simultaneous templates. The algorithm is broken down into three primary components, all of which use normalized cross-correlation (NCC) as a similarity metric. First, a global feature shift to account for gross displacements from the previous frame is determined using large block sizes which encompass the entirety of the feature. Second, the most similar reference frame is chosen from a series of training images that are accumulated during the first K frames of tracking to aid in contour consistency and provide a starting point for the localized template initialization. Finally, localized block matching is performed through the simultaneous use of both a training frame and the previous frame. The localized block matching utilizes a series of templates positioned at the boundary points of the training and previous contours. The weighted final boundary points from both the previous and the training frame are ultimately combined and used to determine an affine transformation from the previous frame to the current frame. A mean tracking error of 0.72 ± 1.25 mm was observed for 85 point-landmarks across 39 ultrasound sequences relative to manual ground truth annotations. The image processing speed per landmark with the GPU implementation was between 41 and 165 frames per second (fps) during the training set accumulation, and between 73 and 234 fps after training set accumulation. Relative to a comparable multithreaded CPU approach using

  19. Are ultrasound-guided ophthalmic blocks injurious to the eye? A comparative rabbit model study of two ultrasound devices evaluating intraorbital thermal and structural changes.

    Science.gov (United States)

    Palte, Howard D; Gayer, Steven; Arrieta, Esdras; Scot Shaw, Eric; Nose, Izuru; Lee, Elizabete; Arheart, Kristopher L; Dubovy, Sander; Birnbach, David J; Parel, Jean-Marie

    2012-07-01

    Since Atkinson's original description of retrobulbar block in 1936, needle-based anesthetic techniques have become integral to ophthalmic anesthesia. These techniques are unfortunately associated with rare, grave complications such as globe perforation. Ultrasound has gained widespread acceptance for peripheral nerve blockade, but its translation to ocular anesthesia has been hampered because sonic energy, in the guise of thermal or biomechanical insult, is potentially injurious to vulnerable eye tissue. The US Food and Drug Administration (FDA) has defined guidelines for safe use of ultrasound for ophthalmic examination, but most ultrasound devices used by anesthesiologists are not FDA-approved for ocular application because they generate excessive energy. Regulating agencies state that ultrasound examinations can be safely undertaken as long as tissue temperatures do not increase >1.5°C above physiological levels. Using a rabbit model, we investigated the thermal and mechanical ocular effects after prolonged ultrasonic exposure to single orbital- and nonorbital-rated devices. In a dual-phase study, aimed at detecting ocular injury, the eyes of 8 rabbits were exposed to continuous 10-minute ultrasound examinations from 2 devices: (1) the Sonosite Micromaxx (nonorbital rated) and (2) the Sonomed VuMax (orbital rated) machines. In phase I, temperatures were continuously monitored via thermocouples implanted within specific eye structures (n = 4). In phase II the eyes were subjected to ultrasonic exposure without surgical intervention (n = 4). All eyes underwent light microscopy examinations, followed at different intervals by histology evaluations conducted by an ophthalmic pathologist. Temperature changes were monitored in the eyes of 4 rabbits. The nonorbital-rated transducer produced increases in ocular tissue temperature that surpassed the safe limit (increases >1.5°C) in the lens of 3 rabbits (at 5.0, 5.5, and 1.5 minutes) and cornea of 2 rabbits (both at 1

  20. Conformation of single block copolymer chain in two-dimensional microphase-separated structure studied by scanning near-field optical microscopy.

    Science.gov (United States)

    Sekine, Ryojun; Aoki, Hiroyuki; Ito, Shinzaburo

    2009-05-21

    The localization and orientation of the symmetric diblock copolymer chain in a quasi-two-dimensional microphase-separated structure were studied by scanning near-field optical microscopy (SNOM). In the monolayer of poly(isobutyl methacrylate)-block-poly(octadecyl methacrylate) (PiBMA-b-PODMA), the individual PiBMA subchains were directly observed by SNOM, and the center of mass (CM) and orientational angle relative to the phase interface were examined at the single chain level. It was found that the position of the CM and the orientation of the PiBMA subchain in the lamellar structure were dependent on the curvature of the PiBMA/PODMA interface. As the interface was bent toward the objective chain, the block chain preferred the CM position closer to the domain center, and the conformation was strongly oriented perpendicularly to the domain interface. With increase of the curvature, the steric hindrance among the block chain increases, resulting in the stretched conformation.

  1. All-Polymer Solar Cells Based on Fully Conjugated Donor-Acceptor Block Copolymers with Poly(naphthalene bisimide Acceptor Blocks: Device Performance and Thin Film Morphology

    Directory of Open Access Journals (Sweden)

    Kazuhiro Nakabayashi

    2015-01-01

    Full Text Available All-polymer solar cells are fabricated by using poly(3-hexylthiophene (P3HT and fully conjugated donor-acceptor (D-A block copolymer (P3HT-PNBI-P3HT as donor and acceptor materials, respectively. Atomic force microscopy (AFM and grazing incidence wide angle X-ray scattering (GIWAXS analyses reveal that device performance strongly depends on the P3HT:P3HT-PNBI-P3HT thin film morphology. Indeed, the π-π stacking nanomorphology rich in the edge-on orientation is formed in the P3HT:P3HT-PNBI-P3HT thin film by optimizing the fabrication conditions, for example, thermal annealing temperature and cast solvent. Consequently, the power conversion efficiency (PCE of 1.60% is achieved with an open-circuit voltage (Voc of 0.59 V, short-current (Jsc of 4.43 mA/cm2, and fill factor (FF of 0.61. These results suggest that P3HT-PNBI-P3HT has the huge potential for the usage as a nonfullerene acceptor material.

  2. Visual-Simulation-Based Personalized Garment Block Design Method for Physically Disabled People with Scoliosis (PDPS

    Directory of Open Access Journals (Sweden)

    Hong Yan

    2018-03-01

    Full Text Available This research presented a novel method using 3D simulation methods to design customized garments for physically disabled people with scoliosis (PDPS. The proposed method is based on the virtual human model created from 3D scanning, permitting to simulate the consumer’s morphological shape with atypical physical deformations. Next, customized 2D and 3D virtual garment prototyping tools will be used to create products through interactions. The proposed 3D garment design method is based on the concept of knowledge-based design, using the design knowledge and process already applied to normal body shapes successfully. The characters of the PDPS and the relationship between human body and garment are considered in the prototyping process. As a visualized collaborative design process, the communication between designer and consumer is ensured, permitting to adapt the finished product to disabled people afflicted with severe scoliosis.

  3. Improving the performance of AlGaN-based deep-ultraviolet light-emitting diodes using electron blocking layer with a heart-shaped graded Al composition

    Science.gov (United States)

    Kwon, M. R.; Park, T. H.; Lee, T. H.; Lee, B. R.; Kim, T. G.

    2018-04-01

    We propose a design for highly efficient AlGaN-based deep-ultraviolet light-emitting diodes (DUV LEDs) using a heart-shaped graded Al composition electron-blocking layer (EBL). This novel structure reduced downward band bending at the interface between the last quantum barrier and the EBL and flattened the electrostatic field in the interlayer between the barriers of the multi-quantum barrier EBL. Consequently, electron leakage was significantly suppressed and hole injection efficiency was found to have improved. The parameter values of simulation were extracted from the experimental data of the reference DUV LEDs. Using the SimuLED, we compared the electrical and optical properties of three structures with different Al compositions in the active region and the EBL. The internal quantum efficiency of the proposed structure was shown to exceed those of the reference DUV LEDs by a factor of 1.9. Additionally, the output power at 20 mA was found to increase by a factor of 2.1.

  4. Comparison of sequence-based and structure-based phylogenetic ...

    Indian Academy of Sciences (India)

    Prakash

    pairs of proteins which are inputs into the construction of phylogenetic trees. We find that correlation between the structure-based dissimilarity measures and the sequence-based dissimilarity measures is usually good if the sequence similarity among the homologues is about 30% or more. For protein families with low ...

  5. New Kids on the Block: RNA-Based Influenza Virus Vaccines.

    Science.gov (United States)

    Scorza, Francesco Berlanda; Pardi, Norbert

    2018-04-01

    RNA-based immunization strategies have emerged as promising alternatives to conventional vaccine approaches. A substantial body of published work demonstrates that RNA vaccines can elicit potent, protective immune responses against various pathogens. Consonant with its huge impact on public health, influenza virus is one of the best studied targets of RNA vaccine research. Currently licensed influenza vaccines show variable levels of protection against seasonal influenza virus strains but are inadequate against drifted and pandemic viruses. In recent years, several types of RNA vaccines demonstrated efficacy against influenza virus infections in preclinical models. Additionally, comparative studies demonstrated the superiority of some RNA vaccines over the currently used inactivated influenza virus vaccines in animal models. Based on these promising preclinical results, clinical trials have been initiated and should provide valuable information about the translatability of the impressive preclinical data to humans. This review briefly describes RNA-based vaccination strategies, summarizes published preclinical and clinical data, highlights the roadblocks that need to be overcome for clinical applications, discusses the landscape of industrial development, and shares the authors' personal perspectives about the future of RNA-based influenza virus vaccines.

  6. Optical phantoms of varying geometry based on thin building blocks with controlled optical properties

    NARCIS (Netherlands)

    de Bruin, Daniel M.; Bremmer, Rolf H.; Kodach, Vitali M.; de Kinkelder, Roy; van Marle, Jan; van Leeuwen, Ton; Faber, Dirk J.

    2010-01-01

    Current innovations in optical imaging, measurement techniques, and data analysis algorithms express the need for reliable testing and comparison methods. We present the design and characterization of silicone elastomer-based optical phantoms. Absorption is included by adding a green dye and

  7. Hydrogel-embedded nanocrystalline hydroxyapatite granules (elastic blocks based on a cross-linked polyvinylpyrrolidone as bone grafting substitute in a rat tibia model

    Directory of Open Access Journals (Sweden)

    Dau M

    2017-10-01

    Full Text Available Michael Dau,1 Cornelia Ganz,2 Franziska Zaage,2 Bernhard Frerich,1 Thomas Gerber2 1Department of Oral, Maxillofacial and Plastic Surgery, University Medical Center Rostock, Rostock, Germany; 2Institute of Physics, Rostock University, Rostock, Germany Purpose: The aim of this study was to examine the in vivo characteristics and levels of integration and degradation of a ready-to-use bone grafting block with elastic properties (elastic block for the use in surgery. Materials and methods: Thirty-six male Wistar rats underwent surgical creation of a well-defined bone defect in the tibia. All created defects – one per animal – were filled with an unsintered nanocrystalline hydroxyapatite embedded either with a non-cross-linked hydrogel carrier (CONT, n=18 or a cross-linked hydrogel carrier (elastic block [EB], n=18 based on polyvinylpyrrolidone (PVP and silica sol, respectively. The animals were killed after 12 (n=12, 21 (n=12 and 63 days (n=12. The bone formation and defect healing were quantified by histomorphometric measurements made in paraffin sections. Additionally, immunohistochemical (tartrate-resistant acid phosphatase [TRAP] and alkaline phosphatase [aP], antibody-based examinations (CD68 and energy-dispersive x-ray scattering measurements of silica atom concentration were carried out. Results: A larger remaining bone defect area overall was observed in EB after 12 days and 21 days. After 63 days, similar areas of remaining bone defects were found. The amount of the remaining carrier material in EB overall was higher at all times. In CONT no residual carrier material was found at 12 days and later. CD68 analyses showed significantly lower level of CD68-positive marked cells after 21 days in CONT, and nonsignificant differences at 12 and 63 days, respectively. Additionally, a significantly higher level of aP-positive marked cells was observed in CONT after 12 days. Later on, the levels of aP-positive marked cells were slightly higher

  8. Measurement of left ventricular torsion using block-matching-based speckle tracking for two-dimensional echocardiography

    Science.gov (United States)

    Sun, Feng-Rong; Wang, Xiao-Jing; Wu, Qiang; Yao, Gui-Hua; Zhang, Yun

    2013-01-01

    Left ventricular (LV) torsion is a sensitive and global index of LV systolic and diastolic function, but how to noninvasively measure it is challenging. Two-dimensional echocardiography and the block-matching based speckle tracking method were used to measure LV torsion. Main advantages of the proposed method over the previous ones are summarized as follows: (1) The method is automatic, except for manually selecting some endocardium points on the end-diastolic frame in initialization step. (2) The diamond search strategy is applied, with a spatial smoothness constraint introduced into the sum of absolute differences matching criterion; and the reference frame during the search is determined adaptively. (3) The method is capable of removing abnormal measurement data automatically. The proposed method was validated against that using Doppler tissue imaging and some preliminary clinical experimental studies were presented to illustrate clinical values of the proposed method.

  9. Identification of rheumatoid arthritis biomarkers based on single nucleotide polymorphisms and haplotype blocks: A systematic review and meta-analysis

    Directory of Open Access Journals (Sweden)

    Mohamed N. Saad

    2016-01-01

    Full Text Available Genetics of autoimmune diseases represent a growing domain with surpassing biomarker results with rapid progress. The exact cause of Rheumatoid Arthritis (RA is unknown, but it is thought to have both a genetic and an environmental bases. Genetic biomarkers are capable of changing the supervision of RA by allowing not only the detection of susceptible individuals, but also early diagnosis, evaluation of disease severity, selection of therapy, and monitoring of response to therapy. This review is concerned with not only the genetic biomarkers of RA but also the methods of identifying them. Many of the identified genetic biomarkers of RA were identified in populations of European and Asian ancestries. The study of additional human populations may yield novel results. Most of the researchers in the field of identifying RA biomarkers use single nucleotide polymorphism (SNP approaches to express the significance of their results. Although, haplotype block methods are expected to play a complementary role in the future of that field.

  10. Vibrational Based Inspection of Civil Engineering Structures

    DEFF Research Database (Denmark)

    Rytter, Anders

    and Structural Engineering at the University of Aalborg since the beginning of 1992. Both projects have been supported by the Danish Technical Research Council. Further, the first mentioned project was supported by the Danish Energy Agency. Their financial support is gratefully acknowledged.......The thesis has been written in relation to two different research projects. Firstly, an offshore test programme, Integrated Experimental/Numerical Analysis of the Dynamic behavior of offshore structures, which was performed at the department of Building Technology and Structural Engineering...... at the University of Aalborg from 1988 to 1991. Secondly, a research project, In-Field Vibration Based Inspection of Civil Engineering Structures, which has been performed as a pilot project by the Consulting Engineers Rambøll, Hannemann and Højlund in cooperation with the department of Building Technology...

  11. Electronic structure of Fe-based superconductors

    Indian Academy of Sciences (India)

    2015-05-29

    May 29, 2015 ... Fe-based superconductors have drawn much attention during the last decade due to the presence of superconductivity in materials containing the magnetic element, Fe, and the coexistence of superconductivity and magnetism. Extensive study of the electronic structure of these systems suggested the ...

  12. Electronic structure of Fe-based superconductors

    Indian Academy of Sciences (India)

    Abstract. Fe-based superconductors have drawn much attention during the last decade due to the presence of superconductivity in materials containing the magnetic element, Fe, and the coexistence of superconductivity and magnetism. Extensive study of the electronic structure of these systems suggested the dominant ...

  13. An Imide-Based Pentacyclic Building Block for n-Type Organic Semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Fu-Peng [Soochow Univ., Suzhou (China). Inst. of Functional Nano & Soft Materials (FUNSOM); Un, Hio-Ieng [Peking Univ., Beijing (China). Beijing National Lab. for Molecular Sciences, Key Lab. of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, Key Lab. of Polymer Chemistry and Physics of Ministry of Education, Center for Soft Matter Science and Engineering, College of Chemistry and Molecular Engineering; Li, Yongxi [Soochow Univ., Suzhou (China). Inst. of Functional Nano & Soft Materials (FUNSOM); Hu, Hailiang [Soochow Univ., Suzhou (China). Inst. of Functional Nano & Soft Materials (FUNSOM); Yuan, Yi [Soochow Univ., Suzhou (China). Inst. of Functional Nano & Soft Materials (FUNSOM); Yang, Bin [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Center for Nanophase Materials Science (CNMS); Xiao, Kai [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Center for Nanophase Materials Science (CNMS); Chen, Wei [Argonne National Lab. (ANL), Lemont, IL (United States). Science Div.; Wang, Jie-Yu [Peking Univ., Beijing (China). Beijing National Lab. for Molecular Sciences, Key Lab. of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, Key Lab. of Polymer Chemistry and Physics of Ministry of Education, Center for Soft Matter Science and Engineering, College of Chemistry and Molecular Engineering; Jiang, Zuo-Quan [Soochow Univ., Suzhou (China). Inst. of Functional Nano & Soft Materials (FUNSOM); Pei, Jian [Peking Univ., Beijing (China). Beijing National Lab. for Molecular Sciences, Key Lab. of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, Key Lab. of Polymer Chemistry and Physics of Ministry of Education, Center for Soft Matter Science and Engineering, College of Chemistry and Molecular Engineering; Liao, Liang-Sheng [Soochow Univ., Suzhou (China). Inst. of Functional Nano & Soft Materials (FUNSOM)

    2017-10-09

    A new electron-deficient unit with fused 5-heterocyclic ring was developed by replacing a cyclopenta-1,3-diene from electron-rich donor indacenodithiophene (IDT) with cyclohepta- 4,6-diene-1,3-diimde unit. The imide bridging endows BBI with fixed planar configuration and both low the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbit (LUMO) energy levels. Organic field-effect transistors (OFETs) based on BBI polymers exhibit electron mobility up to 0.34 cm2 V-1 s-1, which indicates that the BBI is a promising ntype semiconductor for optoelectronics.

  14. Block-Based Gradient Descent for Local Backlight Dimming and Flicker Reduction

    DEFF Research Database (Denmark)

    Burini, Nino; Mantel, Claire; Nadernejad, Ehsan

    2014-01-01

    Local backlight dimming technology is a two-fold improvement for LED backlit LCD screens that allows to reduce power consumption and increase visual quality. This paper presents a fast version of an iterative backlight dimming algorithm based on gradient descent search. The speed is increased...... by exploiting the local uniformity of backlight to reduce the complexity for determining the optimal backlight of a given image. The algorithm is adapted to video sequences by using the backlight of the previous frame as a starting point to calculate the backlight for the current frame. Fast variations...

  15. A novel chaotic block cryptosystem based on iterating map with output-feedback

    International Nuclear Information System (INIS)

    Yang Degang; Liao Xiaofeng; Wang Yong; Yang Huaqian; Wei Pengcheng

    2009-01-01

    A novel method for encryption based on iterating map with output-feedback is presented in this paper. The output-feedback, instead of simply mixing the chaotic signal of the proposed chaotic cryptosystem with the cipher-text, is relating to previous cipher-text that is obtained through the plaintext and key. Some simulated experiments are performed to substantiate that our method can make cipher-text more confusion and diffusion and that the proposed method is practical whenever efficiency, cipher-text length or security is concerned.

  16. Atomic polar tensors and acid-base properties of metal-oxide building blocks

    International Nuclear Information System (INIS)

    Ferris, K.F.

    1993-02-01

    The sensitivity of the atomic polar tensor to compositional substituents is reported for the alkali silicate series. Rotational invariants, effective atomic charge (GAPT) and charge normalized anisotropy and dipole (α n and γ n ) are used to characterize the charge distribution and chemical environment of the atomic sites. Comparison of α n and γ n with a series of known Bronsted and Lewis acids and bases suggests that these rotational invariants may act as indicators for metal-oxide site acidities. Basis set and electron correlation particularly affect the determined effective charge, but show minimal effect on α and γ quantities

  17. Strength and deformability of hollow concrete blocks: correlation of block and cylindrical sample test results

    Directory of Open Access Journals (Sweden)

    C. S. Barbosa

    Full Text Available This paper deals with correlations among mechanical properties of hollow blocks and those of concrete used to make them. Concrete hollow blocks and test samples were moulded with plastic consistency concrete, to assure the same material in all cases, in three diferente levels of strength (nominally 10 N/mm², 20 N/mm² and 30 N/mm². The mechanical properties and structural behaviour in axial compression and tension tests were determined by standard tests in blocks and cylinders. Stress and strain analyses were made based on concrete’s modulus of elasticity obtained in the sample tests as well as on measured strain in the blocks’ face-shells and webs. A peculiar stress-strain analysis, based on the superposition of effects, provided an estimation of the block load capacity based on its deformations. In addition, a tentative method to preview the block deformability from the concrete mechanical properties is described and tested. This analysis is a part of a broader research that aims to support a detailed structural analysis of blocks, prisms and masonry constructions.

  18. A block chain based architecture for asset management in coalition operations

    Science.gov (United States)

    Verma, Dinesh; Desai, Nirmit; Preece, Alun; Taylor, Ian

    2017-05-01

    To support dynamic communities of interests in coalition operations, new architectures for efficient sharing of ISR assets are needed. The use of blockchain technology in wired business environments, such as digital currency systems, offers an interesting solution by creating a way to maintain a distributed shared ledger without requiring a single trusted authority. In this paper, we discuss how a blockchain-based system can be modified to provide a solution for dynamic asset sharing amongst coalition members, enabling the creation of a logically centralized asset management system by a seamless policy-compliant federation of different coalition systems. We discuss the use of blockchain for three different types of assets in a coalition context, showing how blockchain can offer a suitable solution for sharing assets in those environments. We also discuss the limitations in the current implementations of blockchain which need to be overcome for the technology to become more effective in a decentralized tactical edge environment.

  19. Area–Oriented Technology Mapping for LUT–Based Logic Blocks

    Directory of Open Access Journals (Sweden)

    Kubica Marcin

    2017-03-01

    Full Text Available One of the main aspects of logic synthesis dedicated to FPGA is the problem of technology mapping, which is directly associated with the logic decomposition technique. This paper focuses on using configurable properties of CLBs in the process of logic decomposition and technology mapping. A novel theory and a set of efficient techniques for logic decomposition based on a BDD are proposed. The paper shows that logic optimization can be efficiently carried out by using multiple decomposition. The essence of the proposed synthesis method is multiple cutting of a BDD. A new diagram form called an SMTBDD is proposed. Moreover, techniques that allow finding the best technology mapping oriented to configurability of CLBs are presented. In the experimental section, the presented method (MultiDec is compared with academic and commercial tools. The experimental results show that the proposed technology mapping strategy leads to good results in terms of the number of CLBs.

  20. Novel Benzoxazine-Based Aglycones Block Glucose Uptake In Vivo by Inhibiting Glycosidases

    Science.gov (United States)

    Jagadish, Swamy; Paricharak, Shardul; Hemshekhar, Mahadevappa; Mason, Daniel; Kemparaju, Kempaiah; Girish, Kesturu S.; Basappa; Bender, Andreas; Rangappa, Kanchugarakoppal S.

    2014-01-01

    Glycoside hydrolases catalyze the selective hydrolysis of glycosidic bonds in oligosaccharides, polysaccharides, and their conjugates. β-glucosidases occur in all domains of living organisms and constitute a major group among glycoside hydrolases. On the other hand, the benzoxazinoids occur in living systems and act as stable β-glucosides, such as 2-(2,4-dihydroxy-7-methoxy-2H-1,4-benzoxazin-3(4H)-one)-β-D-gluco-pyranose, which hydrolyse to an aglycone DIMBOA. Here, we synthesized the library of novel 1,3-benzoxazine scaffold based aglycones by using 2-aminobenzyl alcohols and aldehydes from one-pot reaction in a chloroacetic acid catalytic system via aerobic oxidative synthesis. Among the synthesized benzoxazines, 4-(7-chloro-2,4-dihydro-1H-benzo[d][1,3]oxazin-2-yl)phenol (compound 7) exhibit significant inhibition towards glucosidase compared to acarbose, with a IC50 value of 11.5 µM. Based upon results generated by in silico target prediction algorithms (Naïve Bayesian classifier), these aglycones potentially target the additional sodium/glucose cotransporter 1 (where a log likelihood score of 2.70 was observed). Furthermore, the in vitro glucosidase activity was correlated with the in silico docking results, with a high docking score for the aglycones towards the substrate binding site of glycosidase. Evidently, the in vitro and in vivo experiments clearly suggest an anti-hyperglycemic effect via glucose uptake inhibition by 4-(7-chloro-2,4-dihydro-1H-benzo[d][1,3]oxazin-2-yl)phenol in the starved rat model. These synthetic aglycones could constitute a novel pharmacological approach for the treatment, or re-enforcement of existing treatments, of type 2 diabetes and associated secondary complications. PMID:25047583

  1. Novel benzoxazine-based aglycones block glucose uptake in vivo by inhibiting glycosidases.

    Directory of Open Access Journals (Sweden)

    Hanumantharayappa Bharathkumar

    Full Text Available Glycoside hydrolases catalyze the selective hydrolysis of glycosidic bonds in oligosaccharides, polysaccharides, and their conjugates. β-glucosidases occur in all domains of living organisms and constitute a major group among glycoside hydrolases. On the other hand, the benzoxazinoids occur in living systems and act as stable β-glucosides, such as 2-(2,4-dihydroxy-7-methoxy-2H-1,4-benzoxazin-3(4H-one-β-D-gluco-pyranose, which hydrolyse to an aglycone DIMBOA. Here, we synthesized the library of novel 1,3-benzoxazine scaffold based aglycones by using 2-aminobenzyl alcohols and aldehydes from one-pot reaction in a chloroacetic acid catalytic system via aerobic oxidative synthesis. Among the synthesized benzoxazines, 4-(7-chloro-2,4-dihydro-1H-benzo[d][1,3]oxazin-2-ylphenol (compound 7 exhibit significant inhibition towards glucosidase compared to acarbose, with a IC50 value of 11.5 µM. Based upon results generated by in silico target prediction algorithms (Naïve Bayesian classifier, these aglycones potentially target the additional sodium/glucose cotransporter 1 (where a log likelihood score of 2.70 was observed. Furthermore, the in vitro glucosidase activity was correlated with the in silico docking results, with a high docking score for the aglycones towards the substrate binding site of glycosidase. Evidently, the in vitro and in vivo experiments clearly suggest an anti-hyperglycemic effect via glucose uptake inhibition by 4-(7-chloro-2,4-dihydro-1H-benzo[d][1,3]oxazin-2-ylphenol in the starved rat model. These synthetic aglycones could constitute a novel pharmacological approach for the treatment, or re-enforcement of existing treatments, of type 2 diabetes and associated secondary complications.

  2. NMR in structure-based drug design.

    Science.gov (United States)

    Carneiro, Marta G; Ab, Eiso; Theisgen, Stephan; Siegal, Gregg

    2017-11-08

    NMR spectroscopy is a powerful technique that can provide valuable structural information for drug discovery endeavors. Here, we discuss the strengths (and limitations) of NMR applications to structure-based drug discovery, highlighting the different levels of resolution and throughput obtainable. Additionally, the emerging field of paramagnetic NMR in drug discovery and recent developments in approaches to speed up and automate protein-observed NMR data collection and analysis are discussed. © 2017 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.

  3. Adaptive neural control of MIMO nonlinear systems with a block-triangular pure-feedback control structure.

    Science.gov (United States)

    Chen, Zhenfeng; Ge, Shuzhi Sam; Zhang, Yun; Li, Yanan

    2014-11-01

    This paper presents adaptive neural tracking control for a class of uncertain multiinput-multioutput (MIMO) nonlinear systems in block-triangular form. All subsystems within these MIMO nonlinear systems are of completely nonaffine pure-feedback form and allowed to have different orders. To deal with the nonaffine appearance of the control variables, the mean value theorem is employed to transform the systems into a block-triangular strict-feedback form with control coefficients being couplings among various inputs and outputs. A systematic procedure is proposed for the design of a new singularity-free adaptive neural tracking control strategy. Such a design procedure can remove the couplings among subsystems and hence avoids the possible circular control construction problem. As a consequence, all the signals in the closed-loop system are guaranteed to be semiglobally uniformly ultimately bounded. Moreover, the outputs of the systems are ensured to converge to a small neighborhood of the desired trajectories. Simulation studies verify the theoretical findings revealed in this paper.

  4. Mechanical analysis of congestive heart failure caused by bundle branch block based on an electromechanical canine heart model

    Energy Technology Data Exchange (ETDEWEB)

    Dou Jianhong; Xia Ling; Zhang Yu; Shou Guofa [Department of Biomedical Engineering, Zhejiang University, Hangzhou 310027 (China); Wei Qing; Liu Feng; Crozier, Stuart [School of Information Technology and Electrical Engineering, University of Queensland, St Lucia, Brisbane, Queensland 4072 (Australia)], E-mail: xialing@zju.edu.cn

    2009-01-21

    Asynchronous electrical activation, induced by bundle branch block (BBB), can cause reduced ventricular function. However, the effects of BBB on the mechanical function of heart are difficult to assess experimentally. Many heart models have been developed to investigate cardiac properties during BBB but have mainly focused on the electrophysiological properties. To date, the mechanical function of BBB has not been well investigated. Based on a three-dimensional electromechanical canine heart model, the mechanical properties of complete left and right bundle branch block (LBBB and RBBB) were simulated. The anatomical model as well as the fiber orientations of a dog heart was reconstructed from magnetic resonance imaging (MRI) and diffusion tensor MRI (DT-MRI). Using the solutions of reaction-diffusion equations and with a strategy of parallel computation, the asynchronous excitation propagation and intraventricular conduction in BBB was simulated. The mechanics of myocardial tissues were computed with time-, sarcomere length-dependent uniaxial active stress initiated at the time of depolarization. The quantification of mechanical intra- and interventricular asynchrony of BBB was then investigated using the finite-element method with an eight-node isoparametric element. The simulation results show that (1) there exists inter- and intraventricular systolic dyssynchrony during BBB; (2) RBBB may have more mechanical synchrony and better systolic function of the left ventricle (LV) than LBBB; (3) the ventricles always move toward the early-activated ventricle; and (4) the septum experiences higher stress than left and right ventricular free walls in BBB. The simulation results validate clinical and experimental recordings of heart deformation and provide regional quantitative estimates of ventricular wall strain and stress. The present work suggests that an electromechanical heart model, incorporating real geometry and fiber orientations, may be helpful for better

  5. Lithium Polymer Electrolytes Based On PMMA / PEG And Penetrant Diffusion In Kraton Penta-Block Ionomer

    Science.gov (United States)

    Meng, Yan

    The study of diffusion in polymeric material is critical to many research fields and applications, such as polymer morphology, protective coatings (paints and varnishes), separation membranes, transport phenomena, polymer electrolytes, polymer melt, and controlled release of drugs from polymer carriers [1-9]. However, it is still a challenge to understand, predict and control the diffusion of molecules and ions of different sizes in polymers [2]. This work studied the medium to long range diffusion of species (i.e., ions and molecules) in solid polymer electrolytes based on poly(ethylene glycol)/poly(methyl methacrylate) (PEG/PMMA) for Li-based batteries, and polymeric permselective membranes via pulsed-field gradient NMR and a.c. impedance. Over the past decades polymer electrolytes have attracted much attention because of their promising technological application as an ion-conducting medium in solid-state batteries, fuel cells, electrochromic displays, and chemical sensors [10, 11]. However, despite numerous studies related to ionic transport in these electrolytes the understanding of the migration mechanism is still far from being complete, and progress in the field remains largely empirical [10, 12-15]. Among various candidates for solid polymer electrolyte (SPE) material, the miscible polymer pair, poly(ethylene oxide)/poly(methyl methacrylate) (PEO/PMMA), is an attractive one, because there is a huge difference in mobility between PEO and PMMA in their blends, and PEO chains remain exceptionally mobile in the blend even at temperature below the glass transition temperature of the blend [ 16]. Thus the mechanical strength and dimensional stability is maintained by PMMA component, while the chain motions or rearrangements of the PEO component virtually contribute to the ion transport [17]. The current work prepared two types of SPE based on poly(ethylene glycol) (PEG) /PMMA (40/60 by weight) for Li-based batteries: lithium bis(trifluoromethylsulfonylimide) (Li

  6. Processing Effects on Block-Copolymer Based Pressure-Sensitive Adhesives

    Science.gov (United States)

    O'Connor, A. E.; Macosko, C. W.

    2000-03-01

    The goal of this work is to investigate how the variables in the hot-melt coating process affect the microstructure and properties of pressure-sensitive adhesives based on a styrene isoprene styrene triblock copolymer. This polymer is a thermoplastic elastomer, able to be coated at high temperatures and physically crosslinked at lower temperatures. Adhesive tape samples have been made through hot-melt and solvent coating methods. Hot-melt coatings are prepared at speeds up to 110 feet/minute. Materials with the same thermal history have been coated using both methods and then tested for comparison of properties. PSA properties are strongly dependent on the time scale of application and debonding, as revealed by shear rheology data, and three types of performance tests (tack, peel, and shear holding power) are used to capture the various responses. Solvent-coated tape has superior shear strength, while hot-melt-coated tape performs better in peel tests. It is expected that the varying flow and deformation histories of the samples will lead to distinct chain orientations, while the rate of cooling of hot-melt-coated samples may influence the degree of phase separation achieved. These factors will cause the adhesive coatings to have different microstructures and therefore different properties.

  7. A Variable Block Insertion Heuristic for the Blocking Flowshop Scheduling Problem with Total Flowtime Criterion

    Directory of Open Access Journals (Sweden)

    Mehmet Fatih Tasgetiren

    2016-10-01

    Full Text Available In this paper, we present a variable block insertion heuristic (VBIH algorithm to solve the blocking flowshop scheduling problem with the total flowtime criterion. In the VBIH algorithm, we define a minimum and a maximum block size. After constructing the initial sequence, the VBIH algorithm starts with a minimum block size being equal to one. It removes the block from the current sequence and inserts it into the partial sequence sequentially with a predetermined move size. The sequence, which is obtained after several block moves, goes under a variable local search (VLS, which is based on traditional insertion and swap neighborhood structures. If the new sequence obtained after the VLS local search is better than the current sequence, it replaces the current sequence. As long as it improves, it keeps the same block size. However, if it does not improve, the block size is incremented by one and a simulated annealing-type of acceptance criterion is used to accept the current sequence. This process is repeated until the block size reaches at the maximum block size. Furthermore, we present a novel constructive heuristic, which is based on the profile fitting heuristic from the literature. The proposed constructive heuristic is able to further improve the best known solutions for some larger instances in a few seconds. Parameters of the constructive heuristic and the VBIH algorithm are determined through a design of experiment approach. Extensive computational results on the Taillard’s well-known benchmark suite show that the proposed VBIH algorithm outperforms the discrete artificial bee colony algorithm, which is one of the most efficient algorithms recently in the literature. Ultimately, 52 out of the 150 best known solutions are further improved with substantial margins.

  8. Structures of PEP–PEO Block Copolymer Micelles: Effects of Changing Solvent and PEO Length and Comparison to a Thermodynamic Model

    DEFF Research Database (Denmark)

    Jensen, Grethe Vestergaard; Shi, Qing; Deen, G. Roshan

    2012-01-01

    changed, leading to a thorough test of this model. With increasing ethanol fraction, the PEP core–solvent interfacial tension decreases, and the solvent quality for PEO changes. The weight-average block masses were 5.0 kDa for PEP and 2.8–49 kDa for PEO. For the lowest PEO molar mass and samples in pure...... water (except for the highest PEO molar mass), the micelles were cylindrical; for other conditions they were spherical. The structural parameters can be reasonably well described by the thermodynamic model by Zhulina et al. [Macromolecules2005, 38 (12), 5330–5351]; however, they have a stronger...

  9. Deployable structures for a human lunar base

    Science.gov (United States)

    Gruber, Petra; Häuplik, Sandra; Imhof, Barbara; Özdemir, Kürsad; Waclavicek, Rene; Perino, Maria Antoinetta

    2007-06-01

    The study Lunar exploration architecture—deployable structures for a lunar base was performed within the Alcatel Alenia Space “Lunar Exploration Architecture” study for the European Space Agency. The purpose of the study was to investigate bionic concepts applicable to deployable structures and to interpret the findings for possible implementation concepts. The study aimed at finding innovative solutions for deployment possibilities. Translating folding/unfolding principles from nature, candidate geometries were developed and researched using models, drawings and visualisations. The use of materials, joints between structural elements and construction details were investigated for these conceptual approaches. Reference scenarios were used to identify the technical and environmental conditions, which served as design drivers. Mechanical issues and the investigation of deployment processes narrowed the selection down to six chosen concepts. Their applicability was evaluated at a conceptual stage in relation to the timescale of the mission.

  10. Reliability Based Optimization of Structural Systems

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard

    1987-01-01

    The optimization problem to design structural systems such that the reliability is satisfactory during the whole lifetime of the structure is considered in this paper. Some of the quantities modelling the loads and the strength of the structure are modelled as random variables. The reliability...... is estimated using first. order reliability methods ( FORM ). The design problem is formulated as the optimization problem to minimize a given cost function such that the reliability of the single elements satisfies given requirements or such that the systems reliability satisfies a given requirement....... For these optimization problems it is described how a sensitivity analysis can be performed. Next, new optimization procedures to solve the optimization problems are presented. Two of these procedures solve the system reliability based optimization problem sequentially using quasi-analytical derivatives. Finally...

  11. A pH- and temperature-responsive bioresorbable injectable hydrogel based on polypeptide block copolymers for the sustained delivery of proteins in vivo.

    Science.gov (United States)

    Turabee, Md Hasan; Thambi, Thavasyappan; Duong, Huu Thuy Trang; Jeong, Ji Hoon; Lee, Doo Sung

    2018-02-27

    Sustained delivery of protein therapeutics is limited owing to the fragile nature of proteins. Despite its great potential, delivery of proteins without any loss of bioactivity remains a challenge in the use of protein therapeutics in the clinic. To surmount this shortcoming, we report a pH- and temperature-responsive in situ-forming injectable hydrogel based on comb-type polypeptide block copolymers for the controlled delivery of proteins. Polypeptide block copolymers, composed of hydrophilic polyethylene glycol (PEG), temperature-responsive poly(γ-benzyl-l-glutamate) (PBLG), and pH-responsive oligo(sulfamethazine) (OSM), exhibit pH- and temperature-induced sol-to-gel transition behavior in aqueous solutions. Polypeptide block copolymers were synthesized by combining N-carboxyanhydride-based ring-opening polymerization and post-functionalization of the chain-end using N-hydroxy succinimide ester activated OSM. The physical properties of polypeptide-based hydrogels were tuned by varying the composition of temperature- and pH-responsive PBLG and OSM in block copolymers. Polypeptide block copolymers were non-toxic to human embryonic kidney cells at high concentrations (2000 μg mL -1 ). Subcutaneous administration of polypeptide block copolymer sols formed viscoelastic gel instantly at the back of Sprague-Dawley (SD) rats. The in vivo gels exhibited sustained degradation and were found to be bioresorbable in 6 weeks without any noticeable inflammation at the injection site. Anionic characteristics of hydrogels allow efficient loading of a cationic model protein, lysozyme, through electrostatic interaction. Lysozyme-loaded polypeptide block copolymer sols readily formed a viscoelastic gel in vivo and sustained lysozyme release for at least a week. Overall, the results demonstrate an elegant approach to control the release of certain charged proteins and open a myriad of therapeutic possibilities in protein therapeutics.

  12. Base isolation strategies for structures and components

    International Nuclear Information System (INIS)

    Varma, Veto; Reddy, G.R.; Vaze, K.K.; Kushwaha, H.S.

    2003-08-01

    In the present report the effect of laminated rubber bearing (LRB) system on the dynamic response of the structure was studied. A LRB system was designed and tested in the laboratory for its dynamic characteristics. Finite element analysis was also performed and based on this analysis, isolator for PHWR nuclear power plant was designed. Analysis of the building was performed with and without isolator. Comparison of responses was made in terms of frequencies, accelerations and displacements and floor response spectra. (author)

  13. Simulation of plasma based semiconductor processing using block structured locally refined grids

    Energy Technology Data Exchange (ETDEWEB)

    Wake, D.D.

    1998-01-01

    We have described a new numerical method for plasma simulation. Calculations have been presented which show that the method is accurate and suggest the regimes in which the method provides savings in CPU time and memory requirements. A steady state simulation of a four centimeter domain was modeled with sheath scale (150 microns) resolution using only 40 grid points. Simulations of semiconductor processing equipment have been performed which imply the usefulness of the method for engineering applications. It is the author`s opinion that these accomplishments represent a significant contribution to plasma simulation and the efficient numerical solution of certain systems of non-linear partial differential equations. More work needs to be done, however, for the algorithm to be of practical use in an engineering environment. Despite our success at avoiding the dielectric relaxation timestep restrictions the algorithm is still conditionally stable and requires timesteps which are relatively small. This represents a prohibitive runtime for steady state solutions on high resolution grids. Current research suggests that these limitations may be overcome and the use of much larger timesteps will be possible.

  14. Enhanced thermal and mechanical properties of poly(trimethylene terephthalate-block-poly(tetramethylene oxide segmented copolymer based hybrid nanocomposites prepared by in situ polymerization via synergy effect between SWCNTs and graphene nanoplatelets

    Directory of Open Access Journals (Sweden)

    S. Paszkiewicz

    2015-06-01

    Full Text Available Graphene nanoplatelets/single walled carbon nanotubes/poly(trimethylene terephthalate-block-poly(tetramethylene oxide segmented copolymer (GNP/SWCNT/PTT-PTMO hybrid nanocomposites were synthesized via in situ polymerization. A remarkable synergistic effect between GNPs and SWCNTs on improving thermal and mechanical properties of nanocomposites based on segmented block copolymers was observed. Heterogeneous structure of the PTT-PTMO allowed for a better and more uniform distribution of both types of nanoparticles and stabilized the structure in question. This enabled us to observe a so-called ‘synergistic effect’, caused by the use of mixture of carbon nanotubes and graphene nanopletelets, on the enhancement of thermal and mechanical properties of the obtained polymer. In order to ascertain the influence of mentioned carbon nanostructures on the nano-phase-separated structure of the synthesized PTT-PTMO block copolymers, differential scanning calorimetric (DSC and dynamic mechanical thermoanalysis (DMTA measurements were performed. Scanning electron microscopic (SEM and transmission electron microscopic (TEM images of the PTTPTMO nanocomposites displayed that hybrid nanofillers exhibited better distribution and compatibility than SWCNTs and GNPs did individually. The tensile modulus of 0.5SWCNT/0.1GNP/PTT-PTMO composites was 68% higher than that of the PTT-PTMO alone, compared to only a 10 and 28% increase in tensile modulus for 0.3GNP/PTT-PTMO and 0.3SWCNT/PTT-PTMO composites respectively (the highest concentration when single nanofiller was added.

  15. POINT CLOUD MODELLING BASED ON THE TUNNEL AXIS AND BLOCK ESTIMATION FOR MONITORING THE BADALING TUNNEL, CHINA

    Directory of Open Access Journals (Sweden)

    J. Wang

    2017-09-01

    Full Text Available Recent years have witnessed a growing investigation of terrestrial laser scanning (TLS for monitoring the deformation of tunnels. TLS provides the ability to obtain a more accurate and complete description of the tunnel surfaces, allowing the determination of the mechanism and magnitude of tunnel deformation, because the entire surface of the tunnel is more concretely modelled rather than being represented by a number of points. This paper models and analyses the point clouds from TLS to detect the possible deformation of a newly built tunnel. In the application of monitoring the Badaling Tunnel for the Winter Olympics 2020 in Beijing, China, the proposed method includes the following components: the tunnel axis is automatically estimated based on a 3D quadratic form estimation; all of the point clouds are segmented into axis-based blocks; and representative points, solved by a singular value decomposition (SVD method, are estimated to describe the tunnel surface and establish the correspondence of data between days. The deformations are detected in the form of the distance discrepancies of representative points and verified by the measurements using total station.

  16. Spatial Structuring and the Development of Number Sense: A Case Study of Young Children Working with Blocks

    Science.gov (United States)

    van Nes, Fenna; van Eerde, Dolly

    2010-01-01

    This case study discusses an activity that makes up one of five lessons in an ongoing classroom teaching experiment. The goal of the teaching experiment is (a) to gain insight into kindergartners' spatial structuring abilities, and (b) to design an educational setting that can support kindergartners in becoming aware of spatial structures and in…

  17. Protein structure based prediction of catalytic residues

    Science.gov (United States)

    2013-01-01

    Background Worldwide structural genomics projects continue to release new protein structures at an unprecedented pace, so far nearly 6000, but only about 60% of these proteins have any sort of functional annotation. Results We explored a range of features that can be used for the prediction of functional residues given a known three-dimensional structure. These features include various centrality measures of nodes in graphs of interacting residues: closeness, betweenness and page-rank centrality. We also analyzed the distance of functional amino acids to the general center of mass (GCM) of the structure, relative solvent accessibility (RSA), and the use of relative entropy as a measure of sequence conservation. From the selected features, neural networks were trained to identify catalytic residues. We found that using distance to the GCM together with amino acid type provide a good discriminant function, when combined independently with sequence conservation. Using an independent test set of 29 annotated protein structures, the method returned 411 of the initial 9262 residues as the most likely to be involved in function. The output 411 residues contain 70 of the annotated 111 catalytic residues. This represents an approximately 14-fold enrichment of catalytic residues on the entire input set (corresponding to a sensitivity of 63% and a precision of 17%), a performance competitive with that of other state-of-the-art methods. Conclusions We found that several of the graph based measures utilize the same underlying feature of protein structures, which can be simply and more effectively captured with the distance to GCM definition. This also has the added the advantage of simplicity and easy implementation. Meanwhile sequence conservation remains by far the most influential feature in identifying functional residues. We also found that due the rapid changes in size and composition of sequence databases, conservation calculations must be recalibrated for specific

  18. 4P-NPD ultra thin-films as efficient exciton blocking layers in DBP/C70 based organic solar cells

    DEFF Research Database (Denmark)

    Patil, Bhushan Ramesh; Liu, Yiming; Qamar, Talha

    2017-01-01

    Exciton blocking effects from ultra thin layers of N,N'-di-1-naphthalenyl-N,N'-diphenyl [1,1':4',1'':4'',1'''-quaterphenyl]-4,4'''-diamine (4P-NPD) was investigated in small molecule based inverted Organic Solar Cells (OSCs) using Tetraphenyldibenzoperiflanthene (DBP) as the electron donor material...... and fullerene (C70) as the electron acceptor material. The short-circuit current density (Jsc) and PCE of the optimized OSCs with 0.7 nm thick 4P-NPD were approx. 16 % and 24 % higher, respectively, compared to reference devices without exciton blocking layers. Drift diffusion based device modeling...... was conducted to model the full Current density – Voltage (JV) characteristics and EQE spectrum of the OSCs, and photoluminescence measurements was conducted to investigate the exciton blocking effects with increasing thicknesses of the 4P-NPD layer. Importantly, coupled optical and electrical modeling studies...

  19. Development of a blocking ELISA for detection of Mycoplasma hyopneumoniae infection based on a monoclonal antibody against protein P65.

    Science.gov (United States)

    Liu, Maojun; DU, Gaimei; Zhang, Yue; Wu, Yuzi; Wang, Haiyan; Li, Bin; Bai, Yun; Feng, Zhixin; Xiong, Qiyan; Bai, Fangfang; Browning, Glenn F; Shao, Guoqing

    2016-09-01

    Mycoplasma hyopneumoniae causes porcine enzootic pneumonia, an economically important disease of swine. A more sensitive and reliable method for detection of serum antibodies is needed for epidemiological investigations and to evaluate the effect of immunization. We expressed the M. hyopneumoniae protein P65 in Escherichia coli and produced a monoclonal antibody (mAb) that bound specifically to recombinant P65. Using this mAb, a blocking enzyme linked immunosorbent assay (ELISA) was developed. The blocking ELISA had similar specificity to and sensitivity with the commercial ELISA produced by IDEXX. Thus, this blocking ELISA is a useful test for serological confirmation of M. hyopneumoniae infection.

  20. Exploring atmospheric blocking with GPS radio occultation observations

    Directory of Open Access Journals (Sweden)

    L. Brunner

    2016-04-01

    Full Text Available Atmospheric blocking has been closely investigated in recent years due to its impact on weather and climate, such as heat waves, droughts, and flooding. We use, for the first time, satellite-based observations from Global Positioning System (GPS radio occultation (RO and explore their ability to resolve blocking in order to potentially open up new avenues complementing models and reanalyses. RO delivers globally available and vertically highly resolved profiles of atmospheric variables such as temperature and geopotential height (GPH. Applying a standard blocking detection algorithm, we find that RO data robustly capture blocking as demonstrated for two well-known blocking events over Russia in summer 2010 and over Greenland in late winter 2013. During blocking episodes, vertically resolved GPH gradients show a distinct anomalous behavior compared to climatological conditions up to 300 hPa and sometimes even further up into the tropopause. The accompanying increase in GPH of up to 300 m in the upper troposphere yields a pronounced tropopause height increase. Corresponding temperatures rise up to 10 K in the middle and lower troposphere. These results demonstrate the feasibility and potential of RO to detect and resolve blocking and in particular to explore the vertical structure of the atmosphere during blocking episodes. This new observation-based view is available globally at the same quality so that blocking in the Southern Hemisphere can also be studied with the same reliability as in the Northern Hemisphere.

  1. Polymeric micelles based on poly(ethylene oxide) and α-carbon substituted poly(ɛ-caprolactone): An in vitro study on the effect of core forming block on polymeric micellar stability, biocompatibility, and immunogenicity.

    Science.gov (United States)

    Garg, Shyam M; Vakili, Mohammad Reza; Lavasanifar, Afsaneh

    2015-08-01

    A series of block copolymers based on methoxy poly(ethylene oxide)-block-poly(ɛ-caprolactone) (PEO-b-PCL), PEO-b-PCL bearing side groups of benzyl carboxylate (PEO-b-PBCL), or free carboxyl (PEO-b-PCCL) on the PCL backbone with increasing degrees of polymerization of the PCL backbone were synthesized. Prepared block copolymers assembled to polymeric micelles by co-solvent evaporation. The physical stability of prepared micelles was assessed by measuring their tendency toward aggregation over time using dynamic light scattering (DLS). The resistance of micelles against dissociation in the presence of a micelle destabilizing agent, i.e., sodium dodecyl sulfate (SDS), was also investigated using DLS. The rate of micellar core degradation was determined using (1)H NMR for polymer molecular weight measurement upon incubation of micelles in PBS (pH=7.4) at 37°C followed by dialysis of the remaining polymer at different time intervals. The effect of pendent group chemistry in the micellar core on the adsorption of serum proteins to micellar structure was then evaluated using Bradford Protein assay kit. Finally, the effect of micellar core structure on the induction of bone marrow derived dendritic cell (BMDC) maturation and secretion of IL-12 was studied as a measure of micellar immunogenicity. The results showed micelle structures from polymers with higher degree of polymerization in the hydrophobic block and/or those with more hydrophobic substituents on the core-forming block, to be more stable. This was reflected by a decreased tendency for micellar aggregation, reduced dissociation of micelles in the presence of SDS, and diminished core degradation. All micelles were shown to have insignificant adsorption of serum protein suggesting that the hydrophilic PEO shell provided sufficient protection of the core. However, the protein adsorption increased with increase in the hydrophobicity and molecular weight of the core-forming block. Irrespective of the micellar core

  2. Structure-based inhibitors of tau aggregation

    Science.gov (United States)

    Seidler, P. M.; Boyer, D. R.; Rodriguez, J. A.; Sawaya, M. R.; Cascio, D.; Murray, K.; Gonen, T.; Eisenberg, D. S.

    2018-02-01

    Aggregated tau protein is associated with over 20 neurological disorders, which include Alzheimer's disease. Previous work has shown that tau's sequence segments VQIINK and VQIVYK drive its aggregation, but inhibitors based on the structure of the VQIVYK segment only partially inhibit full-length tau aggregation and are ineffective at inhibiting seeding by full-length fibrils. Here we show that the VQIINK segment is the more powerful driver of tau aggregation. Two structures of this segment determined by the cryo-electron microscopy method micro-electron diffraction explain its dominant influence on tau aggregation. Of practical significance, the structures lead to the design of inhibitors that not only inhibit tau aggregation but also inhibit the ability of exogenous full-length tau fibrils to seed intracellular tau in HEK293 biosensor cells into amyloid. We also raise the possibility that the two VQIINK structures represent amyloid polymorphs of tau that may account for a subset of prion-like strains of tau.

  3. Crystal engineered acid–base complexes with 2D and 3D hydrogen bonding systems using p-hydroxybenzoic acid as the building block

    Directory of Open Access Journals (Sweden)

    PU SU ZHAO

    2010-04-01

    Full Text Available p-Hydroxybenzoic acid (p-HOBA was selected as the building block for self-assembly with five bases, i.e., diethylamine, tert-butylamine, cyclohexylamine, imidazole and piperazine, and generation of the corresponding acid–base complexes 1–5. Crystal structure analyses suggest that proton-transfer from the carboxyl hydrogen to the nitrogen atom of the bases can be observed in 1–4, while only in 5 does a solvent water molecule co-exist with p--HOBA and piperazine. With the presence of O–H···O hydrogen bonds in 1–4, the deprotonated p-hydroxybenzoate anions (p-HOBAA– are simply connected each other in a head-to-tail motif to form one-dimensional (1D arrays, which are further extended to distinct two-dimensional (2D (for 1 and 4 and three-dimensional (3D (for 2 and 3 networks via N–H···O interactions. While in 5, neutral acid and base are combined pair-wise by O–H···N and N–H···O bonds to form a 1D tape and then the 1D tapes are sequentially combined by water molecules to create a 3D network. Some interlayer or intralayer C–H···O, C–H···p and p×××p interactions help to stabilize the supramolecular buildings. Melting point determination analyses indicate that the five acid–base complexes are not the ordinary superposition of the reactants and they are more stable than the original reactants.

  4. [Mobile ISCR elements: structure, functions, and role in the emergence, increasing and spreading of blocks of bacterial genes of multiple antibiotic resistance].

    Science.gov (United States)

    Il'ina, T S

    2012-01-01

    The recently discovered method of horizontal distribution of bacterial genes with atypical ISCR sequences is reviewed using an example of drug resistance genes. The adjacent DNA segment mobilization is provided by the transposition of such elements, including rolling circle replication, formation of autonomous nonreplicable circular structures, and homological recombination. The gene distribution capacity with the ISCR elements is more significant than the capacity of transposons and integrons, thereby providing formation of groups of mobile genes, including antibiotic-resistance genes of pathogenic bacteria. The structure and functions of the ISCR elements were discussed together with their similarity and dissimilarity with the group of IS91-similar elements and their role in the emergence of blocks of bacterial genes encoding of multiple antibiotic resistance and their contribution to evolution of bacterial and plasmid genes.

  5. The reliability analysis of GaN-based light-emitting diodes with different current-blocking layers

    International Nuclear Information System (INIS)

    Chiou, Y Z; Chiang, T H; Kuo, D S; Chang, S J; Ko, T K; Hon, S J

    2011-01-01

    This study employed Ar plasma treatment to selectively damage the p-GaN surface under the p-pad electrode as a current-blocking layer (CBL) on nitride-based light-emitting diodes (LEDs). Increasing the resistivity of the p-GaN region under the p-pad electrode can reduce the current flowing vertically downward from the p-pad electrode. At an injection current of 20 mA, the light output power of LEDs with Ar plasma treatment was 13% larger than that of conventional LEDs. At an injection current of 100 mA, the temperature of the p-pad metal on LEDs with Ar plasma treatment is 13 °C lower than that of the LEDs with a SiO 2 CBL. However, the electrostatic discharge endurance of LEDs with Ar plasma treatment is the worst due to the surface damage of p-GaN under the p-pad electrode

  6. Shape Memory Composites Based on Electrospun Poly(vinyl alcohol) Fibers and a Thermoplastic Polyether Block Amide Elastomer.

    Science.gov (United States)

    Shirole, Anuja; Sapkota, Janak; Foster, E Johan; Weder, Christoph

    2016-03-01

    The present study aimed at developing new thermally responsive shape-memory composites, that were fabricated by compacting mats of electrospun poly(vinyl alcohol) (PVA) fibers and sheets of a thermoplastic polyether block amide elastomer (PEBA). This design was based on the expectation that the combination of the rubber elasticity of the PEBA matrix and the mechanical switching exploitable through the reversible glass transition temperature (Tg) of the PVA filler could be combined to create materials that display shape memory characteristics as an emergent effect. Dynamic mechanical analyses (DMA) show that, upon introduction of 10-20% w/w PVA fibers, the room-temperature storage modulus (E') increased by a factor of 4-5 in comparison to the neat PEBA, and they reveal a stepwise reduction of E' around the Tg of PVA (85 °C). This transition could indeed be utilized to fix a temporary shape and recover the permanent shape. At low strain, the fixity was 66 ± 14% and the recovery was 98 ± 2%. Overall, the data validate a simple and practical strategy for the fabrication of shape memory composites that involves a melt compaction process and employs two commercially available polymers.

  7. Transiently responsive block copolymer micelles based on N-(2-hydroxypropyl)methacrylamide engineered with hydrolyzable ethylcarbonate side chains

    NARCIS (Netherlands)

    Kasmi, Sabah; Louage, Benoit; Nuhn, Lutz; Van Driessche, Alexandra; Van Deun, Jan; Karalic, Izet; Risseeuw, Martijn; Van Calenbergh, Serge; Hoogenboom, Richard; De Rycke, Riet; De Wever, Olivier; Hennink, Wim E.; de Geest, B.G.

    2016-01-01

    The lack of selectivity and low solubility of many chemotherapeutics impels the development of different biocompatible nanosized drug carriers. Amphiphilic block copolymers, composed of a hydrophilic and hydrophobic domain, show great potential because of their small size, large solubilizing power

  8. Automated extraction of temporal motor activity signals from video recordings of neonatal seizures based on adaptive block matching.

    Science.gov (United States)

    Karayiannis, Nicolaos B; Sami, Abdul; Frost, James D; Wise, Merrill S; Mizrahi, Eli M

    2005-04-01

    This paper presents an automated procedure developed to extract quantitative information from video recordings of neonatal seizures in the form of motor activity signals. This procedure relies on optical flow computation to select anatomical sites located on the infants' body parts. Motor activity signals are extracted by tracking selected anatomical sites during the seizure using adaptive block matching. A block of pixels is tracked throughout a sequence of frames by searching for the most similar block of pixels in subsequent frames; this search is facilitated by employing various update strategies to account for the changing appearance of the block. The proposed procedure is used to extract temporal motor activity signals from video recordings of neonatal seizures and other events not associated with seizures.

  9. Novel biodegradable aliphatic poly(butylene succinate-co-cyclic carbonate)s with functional carbonate building blocks. 1. Chemical synthesis and their structural and physical characterization.

    Science.gov (United States)

    Yang, Jing; Hao, Qinghui; Liu, Xiaoyun; Ba, Chaoyi; Cao, Amin

    2004-01-01

    This study presents chemical synthesis, structural, and physical characterization of novel biodegradable aliphatic poly(butylene succinate-co-cyclic carbonate)s P(BS-co-CC) bearing functional carbonate building blocks. First, five kinds of six-membered cyclic carbonate monomers, namely, trimethylene carbonate (TMC), 1-methyl-1,3-trimethylene carbonate (MTMC), 2,2-dimethyl-1,3-trimethylene carbonate (DMTMC), 5-benzyloxytrimethylene carbonate (BTMC), and 5-ethyl-5-benzyloxymethyl trimethylene carbonate (EBTMC), were well prepared from ethyl chloroformate and corresponding diols at 0 degrees C in THF solution with our modified synthetic strategies. Then, a series of new P(BS-co-CC)s were synthesized at 210 degrees C through a simple combination of poly-condensation and ring-opening-polymerization (ROP) of hydroxyl capped PBS macromers and the prepared carbonate monomers, and titanium tetra-isopropoxide Ti(i-OPr)4 was used as a more suitable catalyst of 5 candidate catalysts which could concurrently catalyze poly-condensation and ROP. By means of NMR, GPC, FTIR, and thermal analytical instruments, macromolecular structures and physical properties have been characterized for these aliphatic poly(ester carbonate)s. The experimental results indicated that novel biodegradable P(BS-co-CC)s were successfully synthesized with number average molecular weight Mn ranging from 24.3 to 99.6 KDa and various CC molar contents without any detectable decarboxylation and that the more bulky side group was attached to a cyclic carbonate monomer, the lower reactivity for its copolymerization would be observed. The occurrences of 13C NMR signal splitting of succinyl carbonyl attributed to the BS building blocks could be proposed due to the randomized sequences of BS and CC building blocks. FTIR characterization indicated two distinct absorption bands at 1716 and 1733 approximately 1735 cm(-1), respectively, stemming from carbonyl stretching modes for corresponding BS and CC units. With

  10. Amphiphilic star block copolymers as gene carrier Part I: Synthesis via ATRP using calix[4]resorcinarene-based initiators and characterization

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Anna; Xue, Yan; Wei, Dafu [Shanghai Key Laboratory of Advanced Polymeric Materials, Key Laboratory for Ultrafine Materials of Ministry of Education, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237 (China); Guan, Yong, E-mail: yguan@ecust.edu.cn [Shanghai Key Laboratory of Advanced Polymeric Materials, Key Laboratory for Ultrafine Materials of Ministry of Education, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237 (China); Xiao, Huining [Department of Chemical Engineering, University of New Brunswick, Fredericton, New Brunswick, Canada E3B 5A3 (Canada)

    2013-01-01

    In this work, a cationic star polymer [poly(2-dimethylamino)ethyl methacrylate (PDMAEMA)] was prepared via atom transfer radical polymerization (ATRP), using brominated calix[4]resorcinarene as an initiator. Hydrophobic moieties, methyl methacrylate (MMA) and butyl acrylate (BA), were further incorporated via 'one-pot' method. Well-defined eight-armed star block copolymers bearing hydrophilic blocks inside and hydrophobic blocks outside were synthesized. The molecular weight, particle size, electrophoretic mobility and apparent charge density were determined by gel permeation chromatography (GPC), dynamic light scattering (DLS), phase analysis light scattering (PALS) and colloidal titration, respectively. The zeta potentials and apparent charge densities of the products exhibited the characteristics of polyelectrolyte. The incorporation of hydrophobic moieties generated electrostatic screening effect. The as-synthesized amphiphilic star copolymer is promising as a thermo-sensitive gene carrier for gene therapy. Highlights: Black-Right-Pointing-Pointer Amphiphilic cationic star block copolymers with well-controlled structures were prepared via ATRP. Black-Right-Pointing-Pointer The molecular structures and properties of the initiator and copolymers were systematically characterized. Black-Right-Pointing-Pointer The products exhibited the positive charged character, and hydrophobic moieties generated electrostatic screening effect.

  11. Implicit Block Diagonal Low-Rank Representation.

    Science.gov (United States)

    Xie, Xingyu; Guo, Xianglin; Liu, Guangcan; Wang, Jun

    2017-10-17

    While current block diagonal constrained subspace clustering methods are performed explicitly on the original data space, in practice it is often more desirable to embed the block diagonal prior into the reproducing kernel Hilbert feature space by kernelization techniques, as the underlying data structure in reality is usually nonlinear. However, it is still unknown how to carry out the embedding and kernelization in the models with block diagonal constraints. In this work, we shall take a step in this direction. First, we establish a novel model termed Implicit Block Diagonal Low-Rank Representation (IBDLR), by incorporating the implicit feature representation and block diagonal prior into the prevalent Low-Rank Representation (LRR) method. Second, mostly important, we show that the model in IBDLR could be kernelized by making use of a smoothed dual representation and the specifics of a proximal gradient based optimization algorithm. Finally, we provide some theoretical analyses for the convergence of our optimization algorithm. Comprehensive experiments on synthetic and realworld datasets demonstrate the superiorities of our IBDLR over state-of-the-art methods.While current block diagonal constrained subspace clustering methods are performed explicitly on the original data space, in practice it is often more desirable to embed the block diagonal prior into the reproducing kernel Hilbert feature space by kernelization techniques, as the underlying data structure in reality is usually nonlinear. However, it is still unknown how to carry out the embedding and kernelization in the models with block diagonal constraints. In this work, we shall take a step in this direction. First, we establish a novel model termed Implicit Block Diagonal Low-Rank Representation (IBDLR), by incorporating the implicit feature representation and block diagonal prior into the prevalent Low-Rank Representation (LRR) method. Second, mostly important, we show that the model in IBDLR could be

  12. Construction of disturbed and intact soil blocks to develop percolating soil based treatment systems for dirty water from dairy farms.

    Science.gov (United States)

    Brookman, S K E; Chadwick, D R; Headon, D M

    2002-03-01

    Intact soil blocks with a surface area of 1.8 x 1.6 m, 1.0 m deep, were excavated in a coarse sandy loam. The sides of the soil blocks were supported with plywood before using hydraulic rams to force a steel cutting plate beneath them. Disturbed soil blocks of the same depth as the intact blocks were also established. Experiments were conducted to determine purification efficiencies for biological oxygen demand (BOD), molybdate reactive phosphorus (MRP), nitrate and ammonium-N after the application of dirty water. A preliminary experiment is described where a low application of dirty water was applied to the soil blocks, 2 mm day(-1). In addition, a chloride tracer was conducted for the duration of the experiment. Disturbed soil had a purification efficiency for BOD of 99% compared to 96% from intact soil (Pammonium-N were 100 and 99%, respectively, for the intact and disturbed soils. Nitrate-N concentration increased in leachate from both treatments reaching maximum concentrations of 15 and 8 mg l(-1) from disturbed and intact soils, respectively. Chloride traces for each soil block followed similar patterns with 47 and 51% loss from disturbed and intact soils, respectively.

  13. Correction: Self-assembled 4-(1,2-diphenylbut-1-en-1-yl)aniline based nanoparticles: podophyllotoxin and aloin as building blocks.

    Science.gov (United States)

    Fumagalli, Gaia; Christodoulou, Michael S; Riva, Benedetta; Revuelta, Inigo; Marucci, Cristina; Collico, Veronica; Prosperi, Davide; Riva, Sergio; Perdicchia, Dario; Bassanini, Ivan; García-Argáez, Aida; Via, Lisa Dalla; Passarella, Daniele

    2017-02-21

    Correction for 'Self-assembled 4-(1,2-diphenylbut-1-en-1-yl)aniline based nanoparticles: podophyllotoxin and aloin as building blocks' by Gaia Fumagalli, et al., Org. Biomol. Chem., 2017, DOI: 10.1039/c6ob02591a.

  14. Effective Application of the Methanol-Based PreservCyt (TM) Fixative and the Cellient (TM) Automated Cell Block Processor to Diagnostic Cytopathology, Immunocytochemistry, and Molecular Biology

    NARCIS (Netherlands)

    van Hemel, Bettien M.; Suurmeijer, Albert J. H.

    We studied the feasibility of immunocytochemistry (ICC), in situ hybridization (ISH), and polymerase chain reaction (PCR) after Cellient automated cell block processing, and tested whether methanol-based PreservCyt fixation could replace formalin fixation, in an attempt to eliminate toxic

  15. Comparison of echocardiography and device based algorithm for atrio-ventricular delay optimization in heart block patients.

    Science.gov (United States)

    Vijayvergiya, Rajesh; Gupta, Ankur

    2015-11-26

    To compare the atrio-ventricular (AV/PV) delay optimization by echocardiography and intra-cardiac electrocardiogram (IEGM) based QuickOpt algorithm in complete heart block (CHB) patients, implanted with a dual chamber pacemaker. We prospectively enrolled 20 patients (age 59.45 ± 18.1 years; male: 65%) with CHB, who were implanted with a dual chamber pacemaker. The left ventricular outflow tract velocity time-integral was measured after AV/PV delay optimization by both echocardiography and QuickOpt algorithm method. Bland-Altman analysis was used for agreement between the two techniques. The optimal AV and PV delay determined by echocardiography was 155.5 ± 14.68 ms and 122.5 ± 17.73 ms (P < 0.0001), respectively and by QuickOpt method was 167.5 ± 16.73 and 117.5 ms ± 9.10 ms (P < 0.0001), respectively. A good agreement was observed between optimal AV and PV delay as measured by two methods. However, the correlation of the optimal AV (r = 0.0689, P = 0.77) and PV (r = 0.2689, P = 0.25) intervals measured by the two techniques was poor. The time required for AV/PV optimization was 45.26 ± 1.73 min by echocardiography and 0.44 ± 0.08 min by QuickOpt method (P < 0.0001). The programmer based IEGM method is an automated, quick, easier and reliable alternative to echocardiography for the optimization of AV/PV delay in CHB patients, implanted with a dual chamber pacemaker.

  16. The potential of solidified molasses-based blocks for the correction of multinutritional deficiencies in buffaloes and other ruminants fed low-quality agro-industrial byproducts

    International Nuclear Information System (INIS)

    Leng, R.A.

    1984-01-01

    The main principles for formulating diets for ruminant animals in developing countries are outlined and examples provided of the successful application of these principles for feeding buffaloes and cattle in India, Philippines and Australia. It is concluded that the provision of a continuous supply of urea in the form of solidified feed blocks to increase the intake and digestibility of roughage-based diets is a management tool that could be used by small farmers in developing countries to improve weight gains and milk yields. Since such blocks can be easily supplemented with macro- and micro-elements needed by ruminants, they could also be useful for correcting multi-nutritional deficiencies. (author)

  17. Comparative Efficacies of Collagen-Based 3D Printed PCL/PLGA/β-TCP Composite Block Bone Grafts and Biphasic Calcium Phosphate Bone Substitute for Bone Regeneration.

    Science.gov (United States)

    Hwang, Kyoung-Sub; Choi, Jae-Won; Kim, Jae-Hun; Chung, Ho Yun; Jin, Songwan; Shim, Jin-Hyung; Yun, Won-Soo; Jeong, Chang-Mo; Huh, Jung-Bo

    2017-04-17

    The purpose of this study was to compare bone regeneration and space maintaining ability of three-dimensional (3D) printed bone grafts with conventional biphasic calcium phosphate (BCP). After mixing polycaprolactone (PCL), poly (lactic-co-glycolic acid) (PLGA), and β-tricalcium phosphate (β-TCP) in a 4:4:2 ratio, PCL/PLGA/β-TCP particulate bone grafts were fabricated using 3D printing technology. Fabricated particulate bone grafts were mixed with atelocollagen to produce collagen-based PCL/PLGA/β-TCP composite block bone grafts. After formation of calvarial defects 8 mm in diameter, PCL/PLGA/β-TCP composite block bone grafts and BCP were implanted into bone defects of 32 rats. Although PCL/PLGA/β-TCP composite block bone grafts were not superior in bone regeneration ability compared to BCP, the results showed relatively similar performance. Furthermore, PCL/PLGA/β-TCP composite block bone grafts showed better ability to maintain bone defects and to support barrier membranes than BCP. Therefore, within the limitations of this study, PCL/PLGA/β-TCP composite block bone grafts could be considered as an alternative to synthetic bone grafts available for clinical use.

  18. In silico-based identification of human α-enolase inhibitors to block cancer cell growth metabolically

    Directory of Open Access Journals (Sweden)

    Lung J

    2017-11-01

    Full Text Available Jrhau Lung,1 Kuan-Liang Chen,2 Chien-Hui Hung,3 Chih-Cheng Chen,4,5 Ming-Szu Hung,5–7 Yu-Ching Lin,5–7 Ching-Yuan Wu,8 Kuan-Der Lee,9 Neng-Yao Shih,10 Ying Huang Tsai11,12 1Department of Medical Research and Development, Chang Gung Memorial Hospital, Chiayi, 2Department of Endodontics, ChiMei Medical Center, Tainan, 3Graduate Institute of Clinical Medical Sciences, Chang Gung University, Taoyuan, 4Division of Hematology and Oncology, Chang Gung Memorial Hospital, Chiayi, 5Department of Medicine, Chang Gung University, Taoyuan, 6Department of Respiratory Care, Chang Gung University of Science and Technology, Chiayi, 7Division of Thoracic Oncology, Department of Pulmonary and Critical Care Medicine, 8Department of Chinese Medicine; Chang Gung Memorial Hospital, Chiayi, 9Department of Hematology and Oncology, Taipei Medical University Hospital, Taipei, 10National Institute of Cancer Research, National Health Research Institutes, Tainan, 11Department of Respiratory Care, College of Medicine, Chang Gung University, Taoyuan, 12Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Chang Gung Memorial Hospital-Kaohsiung Medical Center, Kaohsiung, Taiwan Abstract: Unlimited growth of cancer cells requires an extensive nutrient supply. To meet this demand, cancer cells drastically upregulate glucose uptake and metabolism compared to normal cells. This difference has made the blocking of glycolysis a fascinating strategy to treat this malignant disease. α-enolase is not only one of the most upregulated glycolytic enzymes in cancer cells, but also associates with many cellular processes or conditions important to cancer cell survival, such as cell migration, invasion, and hypoxia. Targeting α-enolase could simultaneously disturb cancer cells in multiple ways and, therefore, is a good target for anticancer drug development. In the current study, more than 22 million chemical structures meeting the criteria of Lipinski

  19. Tungsten - Yttrium Based Nuclear Structural Materials

    Science.gov (United States)

    Ramana, Chintalapalle; Chessa, Jack; Martinenz, Gustavo

    2013-04-01

    The challenging problem currently facing the nuclear science community in this 21st century is design and development of novel structural materials, which will have an impact on the next-generation nuclear reactors. The materials available at present include reduced activation ferritic/martensitic steels, dispersion strengthened reduced activation ferritic steels, and vanadium- or tungsten-based alloys. These materials exhibit one or more specific problems, which are either intrinsic or caused by reactors. This work is focussed towards tungsten-yttrium (W-Y) based alloys and oxide ceramics, which can be utilized in nuclear applications. The goal is to derive a fundamental scientific understanding of W-Y-based materials. In collaboration with University of Califonia -- Davis, the project is designated to demonstrate the W-Y based alloys, ceramics and composites with enhanced physical, mechanical, thermo-chemical properties and higher radiation resistance. Efforts are focussed on understanding the microstructure, manipulating materials behavior under charged-particle and neutron irradiation, and create a knowledge database of defects, elemental diffusion/segregation, and defect trapping along grain boundaries and interfaces. Preliminary results will be discussed.

  20. Side-chain amino-acid-based pH-responsive self-assembled block copolymers for drug delivery and gene transfer.

    Science.gov (United States)

    Kumar, Sonu; Acharya, Rituparna; Chatterji, Urmi; De, Priyadarsi

    2013-12-10

    Developing safe and effective nanocarriers for multitype of delivery system is advantageous for several kinds of successful biomedicinal therapy with the same carrier. In the present study, we have designed amino acid biomolecules derived hybrid block copolymers which can act as a promising vehicle for both drug delivery and gene transfer. Two representative natural chiral amino acid-containing (l-phenylalanine and l-alanine) vinyl monomers were polymerized via reversible addition-fragmentation chain transfer (RAFT) process in the presence of monomethoxy poly(ethylene glycol) based macro-chain transfer agents (mPEGn-CTA) for the synthesis of well-defined side-chain amino-acid-based amphiphilic block copolymers, monomethoxy poly(ethylene glycol)-b-poly(Boc-amino acid methacryloyloxyethyl ester) (mPEGn-b-P(Boc-AA-EMA)). The self-assembled micellar aggregation of these amphiphilic block copolymers were studied by fluorescence spectroscopy, atomic force microscopy (AFM) and scanning electron microscopy (SEM). Potential applications of these hybrid polymers as drug carrier have been demonstrated in vitro by encapsulation of nile red dye or doxorubicin drug into the core of the micellar nanoaggregates. Deprotection of side-chain Boc- groups in the amphiphilic block copolymers subsequently transformed them into double hydrophilic pH-responsive cationic block copolymers having primary amino groups in the side-chain terminal. The DNA binding ability of these cationic block copolymers were further investigated by using agarose gel retardation assay and AFM. The in vitro cytotoxicity assay demonstrated their biocompatible nature and these polymers can serve as "smart" materials for promising bioapplications.