Controlled self-assembly of PbS nanoparticles into macrostar-like hierarchical structures

International Nuclear Information System (INIS)

Li, Guowei; Li, Changsheng; Tang, Hua; Cao, Kesheng; Chen, Juan

2011-01-01

Graphical abstract: The aggregation and rotation of nanoparticles to adopt parallel orientations in three dimensions was indirectly illustrated by TEM and HRTEM images. Highlights: → Macrostar-like PbS hierarchical structures was successfully synthesized by a simple hydrothermal method and mesostars were assembled from the PbS nanocube building blocks with edge lengths of about 100 nm. → Ostwald-ripening-assisted oriented attachment is believed to play a key role in the growth behavior of novel 3D structures. → Optical properties indicating few defects on the surface of the PbS structure and exhibit large blue-shifts compared to bulk PbS. -- Abstract: The synthesis of macrostar-like PbS hierarchical structures by a simple hydrothermal method at 180 o C for 24 h is proven successful with the assistance of a new surfactant called tetrabutylammonium bromide (TBAB). The as-obtained product is characterized by means of X-ray powder diffraction, field emission scanning electron microscopy, energy dispersive spectrometry, high resolution transmission electron microscopy, and selected area electron diffraction. The presence of TBAB and NaF plays an important role in the formation of PbS macrostructures. Ostwald-ripening-assisted oriented attachment is believed to play a key role in the growth behavior of novel 3D structures. As such, a possible self-assembly mechanism is proposed to explain the formation of the said structures. The present study aims to introduce new insights into understanding the formation process of such unique hierarchical superstructures.

Road Network Selection Based on Road Hierarchical Structure Control

Directory of Open Access Journals (Sweden)

HE Haiwei

2015-04-01

Full Text Available A new road network selection method based on hierarchical structure is studied. Firstly, road network is built as strokes which are then classified into hierarchical collections according to the criteria of betweenness centrality value (BC value. Secondly, the hierarchical structure of the strokes is enhanced using structural characteristic identification technique. Thirdly, the importance calculation model was established according to the relationships among the hierarchical structure of the strokes. Finally, the importance values of strokes are got supported with the model's hierarchical calculation, and with which the road network is selected. Tests are done to verify the advantage of this method by comparing it with other common stroke-oriented methods using three kinds of typical road network data. Comparision of the results show that this method had few need to semantic data, and could eliminate the negative influence of edge strokes caused by the criteria of BC value well. So, it is better to maintain the global hierarchical structure of road network, and suitable to meet with the selection of various kinds of road network at the same time.

Mental structures and hierarchical brain processing. Comment on “Toward a computational framework for cognitive biology: Unifying approaches from cognitive neuroscience and comparative cognition” by W. Tecumseh Fitch

Science.gov (United States)

Petkov, C. I.

2014-09-01

Fitch proposes an appealing hypothesis that humans are dendrophiles, who constantly build mental trees supported by analogous hierarchical brain processes [1]. Moreover, it is argued that, by comparison, nonhuman animals build flat or more compact behaviorally-relevant structures. Should we thus expect less impressive hierarchical brain processes in other animals? Not necessarily.

Electroactive nanoparticle directed assembly of functionalized graphene nanosheets into hierarchical structures with hybrid compositions for flexible supercapacitors

Science.gov (United States)

Choi, Bong Gill; Huh, Yun Suk; Hong, Won Hi; Erickson, David; Park, Ho Seok

2013-04-01

Hierarchical structures of hybrid materials with the controlled compositions have been shown to offer a breakthrough for energy storage and conversion. Here, we report the integrative assembly of chemically modified graphene (CMG) building blocks into hierarchical complex structures with the hybrid composition for high performance flexible pseudocapacitors. The formation mechanism of hierarchical CMG/Nafion/RuO2 (CMGNR) microspheres, which is triggered by the cooperative interplay during the in situ synthesis of RuO2 nanoparticles (NPs), was extensively investigated. In particular, the hierarchical CMGNR microspheres consisting of the aggregates of CMG/Nafion (CMGN) nanosheets and RuO2 NPs provided large surface area and facile ion accessibility to storage sites, while the interconnected nanosheets offered continuous electron pathways and mechanical integrity. The synergistic effect of CMGNR hybrids on the supercapacitor (SC) performance was derived from the hybrid composition of pseudocapacitive RuO2 NPs with the conductive CMGNs as well as from structural features. Consequently, the CMGNR-SCs showed a specific capacitance as high as 160 F g-1, three-fold higher than that of conventional graphene SCs, and a capacitance retention of >95% of the maximum value even after severe bending and 1000 charge-discharge tests due to the structural and compositional features.Hierarchical structures of hybrid materials with the controlled compositions have been shown to offer a breakthrough for energy storage and conversion. Here, we report the integrative assembly of chemically modified graphene (CMG) building blocks into hierarchical complex structures with the hybrid composition for high performance flexible pseudocapacitors. The formation mechanism of hierarchical CMG/Nafion/RuO2 (CMGNR) microspheres, which is triggered by the cooperative interplay during the in situ synthesis of RuO2 nanoparticles (NPs), was extensively investigated. In particular, the hierarchical CMGNR

Hierarchical spatial structure of stream fish colonization and extinction

Science.gov (United States)

Hitt, N.P.; Roberts, J.H.

2012-01-01

Spatial variation in extinction and colonization is expected to influence community composition over time. In stream fish communities, local species richness (alpha diversity) and species turnover (beta diversity) are thought to be regulated by high extinction rates in headwater streams and high colonization rates in downstream areas. We evaluated the spatiotemporal structure of fish communities in streams originally surveyed by Burton and Odum 1945 (Ecology 26: 182-194) in Virginia, USA and explored the effects of species traits on extinction and colonization dynamics. We documented dramatic changes in fish community structure at both the site and stream scales. Of the 34 fish species observed, 20 (59%) were present in both time periods, but 11 (32%) colonized the study area and three (9%) were extirpated over time. Within streams, alpha diversity increased in two of three streams but beta diversity decreased dramatically in all streams due to fish community homogenization caused by colonization of common species and extirpation of rare species. Among streams, however, fish communities differentiated over time. Regression trees indicated that reproductive life-history traits such as spawning mound construction, associations with mound-building species, and high fecundity were important predictors of species persistence or colonization. Conversely, native fishes not associated with mound-building exhibited the highest rates of extirpation from streams. Our results demonstrate that stream fish colonization and extinction dynamics exhibit hierarchical spatial structure and suggest that mound-building fishes serve as keystone species for colonization of headwater streams.

Microfabrication of hierarchical structures for engineered mechanical materials

Science.gov (United States)

Vera Canudas, Marc

Materials found in nature present, in some cases, unique properties from their constituents that are of great interest in engineered materials for applications ranging from structural materials for the construction of bridges, canals and buildings to the fabrication of new lightweight composites for airplane and automotive bodies, to protective thin film coatings, amongst other fields. Research in the growing field of biomimetic materials indicates that the micro-architectures present in natural materials are critical to their macroscopic mechanical properties. A better understanding of the effect that structure and hierarchy across scales have on the material properties will enable engineered materials with enhanced properties. At the moment, very few theoretical models predict mechanical properties of simple materials based on their microstructures. Moreover these models are based on observations from complex biological systems. One way to overcome this challenge is through the use of microfabrication techniques to design and fabricate simple materials, more appropriate for the study of hierarchical organizations and microstructured materials. Arrays of structures with controlled geometry and dimension can be designed and fabricated at different length scales, ranging from a few hundred nanometers to centimeters, in order to mimic similar systems found in nature. In this thesis, materials have been fabricated in order to gain fundamental insight into the complex hierarchical materials found in nature and to engineer novel materials with enhanced mechanical properties. The materials fabricated here were mechanically characterized and compared to simple mechanics models to describe their behavior with the goal of applying the knowledge acquired to the design and synthesis of future engineered materials with novel properties.

Discovering hierarchical structure in normal relational data

DEFF Research Database (Denmark)

Schmidt, Mikkel Nørgaard; Herlau, Tue; Mørup, Morten

2014-01-01

-parametric generative model for hierarchical clustering of similarity based on multifurcating Gibbs fragmentation trees. This allows us to infer and display the posterior distribution of hierarchical structures that comply with the data. We demonstrate the utility of our method on synthetic data and data of functional...

Bio-inspired fabrication of stimuli-responsive photonic crystals with hierarchical structures and their applications

International Nuclear Information System (INIS)

Lu, Tao; Peng, Wenhong; Zhu, Shenmin; Zhang, Di

2016-01-01

When the constitutive materials of photonic crystals (PCs) are stimuli-responsive, the resultant PCs exhibit optical properties that can be tuned by the stimuli. This can be exploited for promising applications in colour displays, biological and chemical sensors, inks and paints, and many optically active components. However, the preparation of the required photonic structures is the first issue to be solved. In the past two decades, approaches such as microfabrication and self-assembly have been developed to incorporate stimuli-responsive materials into existing periodic structures for the fabrication of PCs, either as the initial building blocks or as the surrounding matrix. Generally, the materials that respond to thermal, pH, chemical, optical, electrical, or magnetic stimuli are either soft or aggregate, which is why the manufacture of three-dimensional hierarchical photonic structures with responsive properties is a great challenge. Recently, inspired by biological PCs in nature which exhibit both flexible and responsive properties, researchers have developed various methods to synthesize metals and metal oxides with hierarchical structures by using a biological PC as the template. This review will focus on the recent developments in this field. In particular, PCs with biological hierarchical structures that can be tuned by external stimuli have recently been successfully fabricated. These findings offer innovative insights into the design of responsive PCs and should be of great importance for future applications of these materials. (topical review)

Hierarchical drivers of reef-fish metacommunity structure.

Science.gov (United States)

MacNeil, M Aaron; Graham, Nicholas A J; Polunin, Nicholas V C; Kulbicki, Michel; Galzin, René; Harmelin-Vivien, Mireille; Rushton, Steven P

2009-01-01

Coral reefs are highly complex ecological systems, where multiple processes interact across scales in space and time to create assemblages of exceptionally high biodiversity. Despite the increasing frequency of hierarchically structured sampling programs used in coral-reef science, little progress has been made in quantifying the relative importance of processes operating across multiple scales. The vast majority of reef studies are conducted, or at least analyzed, at a single spatial scale, ignoring the implicitly hierarchical structure of the overall system in favor of small-scale experiments or large-scale observations. Here we demonstrate how alpha (mean local number of species), beta diversity (degree of species dissimilarity among local sites), and gamma diversity (overall species richness) vary with spatial scale, and using a hierarchical, information-theoretic approach, we evaluate the relative importance of site-, reef-, and atoll-level processes driving the fish metacommunity structure among 10 atolls in French Polynesia. Process-based models, representing well-established hypotheses about drivers of reef-fish community structure, were assembled into a candidate set of 12 hierarchical linear models. Variation in fish abundance, biomass, and species richness were unevenly distributed among transect, reef, and atoll levels, establishing the relative contribution of variation at these spatial scales to the structure of the metacommunity. Reef-fish biomass, species richness, and the abundance of most functional-groups corresponded primarily with transect-level habitat diversity and atoll-lagoon size, whereas detritivore and grazer abundances were largely correlated with potential covariates of larval dispersal. Our findings show that (1) within-transect and among-atoll factors primarily drive the relationship between alpha and gamma diversity in this reef-fish metacommunity; (2) habitat is the primary correlate with reef-fish metacommunity structure at

Hierarchically structured materials for lithium batteries

International Nuclear Information System (INIS)

Xiao, Jie; Zheng, Jianming; Li, Xiaolin; Shao, Yuyan; Zhang, Ji-Guang

2013-01-01

The lithium-ion battery (LIB) is one of the most promising power sources to be deployed in electric vehicles, including solely battery powered vehicles, plug-in hybrid electric vehicles, and hybrid electric vehicles. With the increasing demand for devices of high-energy densities (>500 Wh kg −1 ), new energy storage systems, such as lithium–oxygen (Li–O 2 ) batteries and other emerging systems beyond the conventional LIB, have attracted worldwide interest for both transportation and grid energy storage applications in recent years. It is well known that the electrochemical performance of these energy storage systems depends not only on the composition of the materials, but also on the structure of the electrode materials used in the batteries. Although the desired performance characteristics of batteries often have conflicting requirements with the micro/nano-structure of electrodes, hierarchically designed electrodes can be tailored to satisfy these conflicting requirements. This work will review hierarchically structured materials that have been successfully used in LIB and Li–O 2 batteries. Our goal is to elucidate (1) how to realize the full potential of energy materials through the manipulation of morphologies, and (2) how the hierarchical structure benefits the charge transport, promotes the interfacial properties and prolongs the electrode stability and battery lifetime. (paper)

Hierarchical modeling and its numerical implementation for layered thin elastic structures

Energy Technology Data Exchange (ETDEWEB)

Cho, Jin-Rae [Hongik University, Sejong (Korea, Republic of)

2017-05-15

Thin elastic structures such as beam- and plate-like structures and laminates are characterized by the small thickness, which lead to classical plate and laminate theories in which the displacement fields through the thickness are assumed linear or higher-order polynomials. These classical theories are either insufficient to represent the complex stress variation through the thickness or may encounter the accuracy-computational cost dilemma. In order to overcome the inherent problem of classical theories, the concept of hierarchical modeling has been emerged. In the hierarchical modeling, the hierarchical models with different model levels are selected and combined within a structure domain, in order to make the modeling error be distributed as uniformly as possible throughout the problem domain. The purpose of current study is to explore the potential of hierarchical modeling for the effective numerical analysis of layered structures such as laminated composite. For this goal, the hierarchical models are constructed and the hierarchical modeling is implemented by selectively adjusting the level of hierarchical models. As well, the major characteristics of hierarchical models are investigated through the numerical experiments.

Hierarchical assembly of inorganic nanostructure building blocks to octahedral superstructures-a true template-free self-assembly

International Nuclear Information System (INIS)

Kuchibhatla, Satyanarayana V N T; Karakoti, Ajay S; Seal, Sudipta

2007-01-01

A room temperature, template-free, wet chemical synthesis of ceria nanoparticles and their long term ageing characteristics are reported. High resolution transmission electron microscopy and UV-visible spectroscopy techniques are used to observe the variation in size, structure and oxidation state, respectively as a function of time. The morphology variation and the hierarchical assembly (octahedral superstructure) of nanostructures are imputed to the inherent structural aspects of cerium oxide. It is hypothesized that the 3-5 nm individual building blocks will undergo an intra-agglomerate re-orientation to attain the low energy configuration. This communication also emphasizes the need for long term ageing studies of nanomaterials in various solvents for multiple functionalities

BiOCl nanowire with hierarchical structure and its Raman features

International Nuclear Information System (INIS)

Tian Ye; Guo Chuanfei; Guo Yanjun; Wang Qi; Liu Qian

2012-01-01

BiOCl is a promising V-VI-VII-compound semiconductor with excellent optical and electrical properties, and has great potential applications in photo-catalysis, photoelectric, etc. We successfully synthesize BiOCl nanowire with a hierarchical structure by combining wet etch (top-down) with liquid phase crystal growth (bottom-up) process, opening a novel method to construct ordered bismuth-based nanostructures. The morphology and lattice structures of Bi nanowires, β-Bi 2 O 3 nanowires and BiOCl nanowires with the hierarchical structure are investigated by scanning electron microscope (SEM) and transition electron microscope (TEM). The formation mechanism of such ordered BiOCl hierarchical structure is considered to mainly originate from the highly preferred growth, which is governed by the lattice match between (1 1 0) facet of BiOCl and (2 2 0) or (0 0 2) facet of β-Bi 2 O 3 . A schematic model is also illustrated to depict the formation process of the ordered BiOCl hierarchical structure. In addition, Raman properties of the BiOCl nanowire with the hierarchical structure are investigated deeply.

Hierarchical Fiber Structures Made by Electrospinning Polymers

Science.gov (United States)

Reneker, Darrell H.

2009-03-01

A filter for water purification that is very thin, with small interstices and high surface area per unit mass, can be made with nanofibers. The mechanical strength of a very thin sheet of nanofibers is not great enough to withstand the pressure drop of the fluid flowing through. If the sheet of nanofibers is made thicker, the strength will increase, but the flow will be reduced to an impractical level. An optimized filter can be made with nanometer scale structures supported on micron scale structures, which are in turn supported on millimeter scale structures. This leads to a durable hierarchical structure to optimize the filtration efficiency with a minimum amount of material. Buckling coils,ootnotetextTao Han, Darrell H Reneker, Alexander L. Yarin, Polymer, Volume 48, issue 20 (September 21, 2007), p. 6064-6076. electrical bending coilsootnotetextDarrell H. Reneker and Alexander L. Yarin, Polymer, Volume 49, Issue 10 (2008) Pages 2387-2425, DOI:10.1016/j.polymer.2008.02.002. Feature Article. and pendulum coilsootnotetextT. Han, D.H. Reneker, A.L. Yarin, Polymer, Volume 49, (2008) Pages 2160-2169, doi:10.1016/jpolymer.2008.01.0487878. spanning dimensions from a few microns to a few centimeters can be collected from a single jet by controlling the position and motion of a collector. Attractive routes to the design and construction of hierarchical structures for filtration are based on nanofibers supported on small coils that are in turn supported on larger coils, which are supported on even larger overlapping coils. ``Such top-down'' hierarchical structures are easy to make by electrospinning. In one example, a thin hierarchical structure was made, with a high surface area and small interstices, having an open area of over 50%, with the thinnest fibers supported at least every 15 microns.

Facile fabrication of superhydrophobic surfaces with hierarchical structures.

Science.gov (United States)

Lee, Eunyoung; Lee, Kun-Hong

2018-03-06

Hierarchical structures were fabricated on the surfaces of SUS304 plates using a one-step process of direct microwave irradiation under a carbon dioxide atmosphere. The surface nanostructures were composed of chrome-doped hematite single crystals. Superhydrophobic surfaces with a water contact angle up to 169° were obtained by chemical modification of the hierarchical structures. The samples maintained superhydrophobicity under NaCl solution up to 2 weeks.

CHIMERA: Top-down model for hierarchical, overlapping and directed cluster structures in directed and weighted complex networks

Science.gov (United States)

Franke, R.

2016-11-01

In many networks discovered in biology, medicine, neuroscience and other disciplines special properties like a certain degree distribution and hierarchical cluster structure (also called communities) can be observed as general organizing principles. Detecting the cluster structure of an unknown network promises to identify functional subdivisions, hierarchy and interactions on a mesoscale. It is not trivial choosing an appropriate detection algorithm because there are multiple network, cluster and algorithmic properties to be considered. Edges can be weighted and/or directed, clusters overlap or build a hierarchy in several ways. Algorithms differ not only in runtime, memory requirements but also in allowed network and cluster properties. They are based on a specific definition of what a cluster is, too. On the one hand, a comprehensive network creation model is needed to build a large variety of benchmark networks with different reasonable structures to compare algorithms. On the other hand, if a cluster structure is already known, it is desirable to separate effects of this structure from other network properties. This can be done with null model networks that mimic an observed cluster structure to improve statistics on other network features. A third important application is the general study of properties in networks with different cluster structures, possibly evolving over time. Currently there are good benchmark and creation models available. But what is left is a precise sandbox model to build hierarchical, overlapping and directed clusters for undirected or directed, binary or weighted complex random networks on basis of a sophisticated blueprint. This gap shall be closed by the model CHIMERA (Cluster Hierarchy Interconnection Model for Evaluation, Research and Analysis) which will be introduced and described here for the first time.

Hierarchical structures of correlations networks among Turkey’s exports and imports by currencies

Science.gov (United States)

Kocakaplan, Yusuf; Deviren, Bayram; Keskin, Mustafa

2012-12-01

We have examined the hierarchical structures of correlations networks among Turkey’s exports and imports by currencies for the 1996-2010 periods, using the concept of a minimal spanning tree (MST) and hierarchical tree (HT) which depend on the concept of ultrametricity. These trees are useful tools for understanding and detecting the global structure, taxonomy and hierarchy in financial markets. We derived a hierarchical organization and build the MSTs and HTs during the 1996-2001 and 2002-2010 periods. The reason for studying two different sub-periods, namely 1996-2001 and 2002-2010, is that the Euro (EUR) came into use in 2001, and some countries have made their exports and imports with Turkey via the EUR since 2002, and in order to test various time-windows and observe temporal evolution. We have carried out bootstrap analysis to associate a value of the statistical reliability to the links of the MSTs and HTs. We have also used the average linkage cluster analysis (ALCA) to observe the cluster structure more clearly. Moreover, we have obtained the bidimensional minimal spanning tree (BMST) due to economic trade being a bidimensional problem. From the structural topologies of these trees, we have identified different clusters of currencies according to their proximity and economic ties. Our results show that some currencies are more important within the network, due to a tighter connection with other currencies. We have also found that the obtained currencies play a key role for Turkey’s exports and imports and have important implications for the design of portfolio and investment strategies.

Hierarchically Structured Electrospun Fibers

Science.gov (United States)

2013-01-07

in the natural lotus and silver ragwort leaves. Figure 4. Examples of electrospun bio-mimics of natural hierarchical structures. (A) Lotus leaf...B) pillared poly(methyl methacrylate) (PMMA) electrospun fiber mimic; (C) silver ragwort leaf; (D) electrospun fiber mimic made from nylon 6 and...domains containing the protein in the surrounding EVA fibers [115]. A wide variety of core-shell fibers have been generated, including PCL/ gelatin

Resolution of Singularities Introduced by Hierarchical Structure in Deep Neural Networks.

Science.gov (United States)

Nitta, Tohru

2017-10-01

We present a theoretical analysis of singular points of artificial deep neural networks, resulting in providing deep neural network models having no critical points introduced by a hierarchical structure. It is considered that such deep neural network models have good nature for gradient-based optimization. First, we show that there exist a large number of critical points introduced by a hierarchical structure in deep neural networks as straight lines, depending on the number of hidden layers and the number of hidden neurons. Second, we derive a sufficient condition for deep neural networks having no critical points introduced by a hierarchical structure, which can be applied to general deep neural networks. It is also shown that the existence of critical points introduced by a hierarchical structure is determined by the rank and the regularity of weight matrices for a specific class of deep neural networks. Finally, two kinds of implementation methods of the sufficient conditions to have no critical points are provided. One is a learning algorithm that can avoid critical points introduced by the hierarchical structure during learning (called avoidant learning algorithm). The other is a neural network that does not have some critical points introduced by the hierarchical structure as an inherent property (called avoidant neural network).

Hierarchical structure of moral stages assessed by a sorting task

NARCIS (Netherlands)

Boom, J.; Brugman, D.; Van der Heijden, P.G.M.

2001-01-01

Following criticism of Kohlberg’s theory of moral judgment, an empirical re-examination of hierarchical stage structure was desirable. Utilizing Piaget’s concept of reflective abstraction as a basis, the hierarchical stage structure was investigated using a new method. Study participants (553 Dutch

Filamentous phages as building blocks for reconfigurable and hierarchical self-assembly

Science.gov (United States)

Gibaud, Thomas

2017-12-01

Filamentous bacteriophages such as fd-like viruses are monodisperse rod-like colloids that have well defined properties of diameter, length, rigidity, charge and chirality. Engineering these viruses leads to a library of colloidal rods, which can be used as building blocks for reconfigurable and hierarchical self-assembly. Their condensation in an aqueous solution with additive polymers, which act as depletants to induce attraction between the rods, leads to a myriad of fluid-like micronic structures ranging from isotropic/nematic droplets, colloid membranes, achiral membrane seeds, twisted ribbons, π-wall, pores, colloidal skyrmions, Möbius anchors, scallop membranes to membrane rafts. These structures, and the way that they shape-shift, not only shed light on the role of entropy, chiral frustration and topology in soft matter, but also mimic many structures encountered in different fields of science. On the one hand, filamentous phages being an experimental realization of colloidal hard rods, their condensation mediated by depletion interactions constitutes a blueprint for the self-assembly of rod-like particles and provides a fundamental foundation for bio- or material-oriented applications. On the other hand, the chiral properties of the viruses restrict the generalities of some results but vastly broaden the self-assembly possibilities.

Tensegrity I. Cell structure and hierarchical systems biology

Science.gov (United States)

Ingber, Donald E.

2003-01-01

In 1993, a Commentary in this journal described how a simple mechanical model of cell structure based on tensegrity architecture can help to explain how cell shape, movement and cytoskeletal mechanics are controlled, as well as how cells sense and respond to mechanical forces (J. Cell Sci. 104, 613-627). The cellular tensegrity model can now be revisited and placed in context of new advances in our understanding of cell structure, biological networks and mechanoregulation that have been made over the past decade. Recent work provides strong evidence to support the use of tensegrity by cells, and mathematical formulations of the model predict many aspects of cell behavior. In addition, development of the tensegrity theory and its translation into mathematical terms are beginning to allow us to define the relationship between mechanics and biochemistry at the molecular level and to attack the larger problem of biological complexity. Part I of this two-part article covers the evidence for cellular tensegrity at the molecular level and describes how this building system may provide a structural basis for the hierarchical organization of living systems--from molecule to organism. Part II, which focuses on how these structural networks influence information processing networks, appears in the next issue.

On Hierarchical Extensions of Large-Scale 4-regular Grid Network Structures

DEFF Research Database (Denmark)

Pedersen, Jens Myrup; Patel, A.; Knudsen, Thomas Phillip

2004-01-01

dependencies between the number of nodes and the distances in the structures. The perfect square mesh is introduced for hierarchies, and it is shown that applying ordered hierarchies in this way results in logarithmic dependencies between the number of nodes and the distances, resulting in better scaling...... structures. For example, in a mesh of 391876 nodes the average distance is reduced from 417.33 to 17.32 by adding hierarchical lines. This is gained by increasing the number of lines by 4.20% compared to the non-hierarchical structure. A similar hierarchical extension of the torus structure also results...

Growth Mechanism of Pumpkin-Shaped Vaterite Hierarchical Structures

Science.gov (United States)

Ma, Guobin; Xu, Yifei; Wang, Mu

2015-03-01

CaCO3-based biominerals possess sophisticated hierarchical structures and promising mechanical properties. Recent researches imply that vaterite may play an important role in formation of CaCO3-based biominerals. However, as a less common polymorph of CaCO3, the growth mechanism of vaterite remains not very clear. Here we report the growth of a pumpkin-shaped vaterite hierarchical structure with a six-fold symmetrical axis and lamellar microstructure. We demonstrate that the growth is controlled by supersaturation and the intrinsic crystallographic anisotropy of vaterite. For the scenario of high supersaturation, the nucleation rate is higher than the lateral extension rate, favoring the ``double-leaf'' spherulitic growth. Meanwhile, nucleation occurs preferentially in as determined by the crystalline structure of vaterite, modulating the grown products with a hexagonal symmetry. The results are beneficial for an in-depth understanding of the biomineralization of CaCO3. The growth mechanism may also be applicable to interpret the formation of similar hierarchical structures of other materials. The authors gratefully acknowledge the financial support from National Science Foundation of China (Grant Nos. 51172104 and 50972057) and National Key Basic Research Program of China (Grant No. 2010CB630705).

A Hierarchical Dispatch Structure for Distribution Network Pricing

OpenAIRE

Yuan, Zhao; Hesamzadeh, Mohammad Reza

2015-01-01

This paper presents a hierarchical dispatch structure for efficient distribution network pricing. The dispatch coordination problem in the context of hierarchical network operators are addressed. We formulate decentralized generation dispatch into a bilevel optimization problem in which main network operator and the connected distribution network operator optimize their costs in two levels. By using Karush-Kuhn-Tucker conditions and Fortuny-Amat McCarl linearization, the bilevel optimization ...

Hierarchical structure of stock price fluctuations in financial markets

International Nuclear Information System (INIS)

Gao, Ya-Chun; Cai, Shi-Min; Wang, Bing-Hong

2012-01-01

The financial market and turbulence have been broadly compared on account of the same quantitative methods and several common stylized facts they share. In this paper, the She–Leveque (SL) hierarchy, proposed to explain the anomalous scaling exponents deviating from Kolmogorov monofractal scaling of the velocity fluctuation in fluid turbulence, is applied to study and quantify the hierarchical structure of stock price fluctuations in financial markets. We therefore observed certain interesting results: (i) the hierarchical structure related to multifractal scaling generally presents in all the stock price fluctuations we investigated. (ii) The quantitatively statistical parameters that describe SL hierarchy are different between developed financial markets and emerging ones, distinctively. (iii) For the high-frequency stock price fluctuation, the hierarchical structure varies with different time periods. All these results provide a novel analogy in turbulence and financial market dynamics and an insight to deeply understand multifractality in financial markets. (paper)

Hierarchical structure in the distribution of galaxies

International Nuclear Information System (INIS)

Schulman, L.S.; Seiden, P.E.; Technion - Israel Institute of Technology, Haifa; IBM Thomas J. Watson Research Center, Yorktown Heights, NY)

1986-01-01

The distribution of galaxies has a hierarchical structure with power-law correlations. This is usually thought to arise from gravity alone acting on an originally uniform distributioon. If, however, the original process of galaxy formation occurs through the stimulated birth of one galaxy due to a nearby recently formed galaxy, and if this process occurs near its percolation threshold, then a hierarchical structure with power-law correlations arises at the time of galaxy formation. If subsequent gravitational evolution within an expanding cosmology is such as to retain power-law correlations, the initial r exp -1 dropoff can steepen to the observed r exp -1.8. The distribution of galaxies obtained by this process produces clustering and voids, as observed. 23 references

Wetting and Dewetting Transitions on Submerged Superhydrophobic Surfaces with Hierarchical Structures.

Science.gov (United States)

Wu, Huaping; Yang, Zhe; Cao, Binbin; Zhang, Zheng; Zhu, Kai; Wu, Bingbing; Jiang, Shaofei; Chai, Guozhong

2017-01-10

The wetting transition on submersed superhydrophobic surfaces with hierarchical structures and the influence of trapped air on superhydrophobic stability are predicted based on the thermodynamics and mechanical analyses. The dewetting transition on the hierarchically structured surfaces is investigated, and two necessary thermodynamic conditions and a mechanical balance condition for dewetting transition are proposed. The corresponding thermodynamic phase diagram of reversible transition and the critical reversed pressure well explain the experimental results reported previously. Our theory provides a useful guideline for precise controlling of breaking down and recovering of superhydrophobicity by designing superhydrophobic surfaces with hierarchical structures under water.

Hierarchically nanostructured hydroxyapatite: hydrothermal synthesis, morphology control, growth mechanism, and biological activity

Science.gov (United States)

Ma, Ming-Guo

2012-01-01

Hierarchically nanosized hydroxyapatite (HA) with flower-like structure assembled from nanosheets consisting of nanorod building blocks was successfully synthesized by using CaCl2, NaH2PO4, and potassium sodium tartrate via a hydrothermal method at 200°C for 24 hours. The effects of heating time and heating temperature on the products were investigated. As a chelating ligand and template molecule, the potassium sodium tartrate plays a key role in the formation of hierarchically nanostructured HA. On the basis of experimental results, a possible mechanism based on soft-template and self-assembly was proposed for the formation and growth of the hierarchically nanostructured HA. Cytotoxicity experiments indicated that the hierarchically nanostructured HA had good biocompatibility. It was shown by in-vitro experiments that mesenchymal stem cells could attach to the hierarchically nanostructured HA after being cultured for 48 hours. Objective The purpose of this study was to develop facile and effective methods for the synthesis of novel hydroxyapatite (HA) with hierarchical nanostructures assembled from independent and discrete nanobuilding blocks. Methods A simple hydrothermal approach was applied to synthesize HA by using CaCl2, NaH2PO4, and potassium sodium tartrate at 200°C for 24 hours. The cell cytotoxicity of the hierarchically nanostructured HA was tested by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. Results HA displayed the flower-like structure assembled from nanosheets consisting of nanorod building blocks. The potassium sodium tartrate was used as a chelating ligand, inducing the formation and self-assembly of HA nanorods. The heating time and heating temperature influenced the aggregation and morphology of HA. The cell viability did not decrease with the increasing concentration of hierarchically nanostructured HA added. Conclusion A novel, simple and reliable hydrothermal route had been developed for the synthesis of

Detecting the overlapping and hierarchical community structure in complex networks

International Nuclear Information System (INIS)

Lancichinetti, Andrea; Fortunato, Santo; Kertesz, Janos

2009-01-01

Many networks in nature, society and technology are characterized by a mesoscopic level of organization, with groups of nodes forming tightly connected units, called communities or modules, that are only weakly linked to each other. Uncovering this community structure is one of the most important problems in the field of complex networks. Networks often show a hierarchical organization, with communities embedded within other communities; moreover, nodes can be shared between different communities. Here, we present the first algorithm that finds both overlapping communities and the hierarchical structure. The method is based on the local optimization of a fitness function. Community structure is revealed by peaks in the fitness histogram. The resolution can be tuned by a parameter enabling different hierarchical levels of organization to be investigated. Tests on real and artificial networks give excellent results.

New insight in magnetic saturation behavior of nickel hierarchical structures

Science.gov (United States)

Ma, Ji; Zhang, Jianxing; Liu, Chunting; Chen, Kezheng

2017-09-01

It is unanimously accepted that non-ferromagnetic inclusions in a ferromagnetic system will lower down total saturation magnetization in unit of emu/g. In this study, ;lattice strain; was found to be another key factor to have critical impact on magnetic saturation behavior of the system. The lattice strain determined assembling patterns of primary nanoparticles in hierarchical structures and was intimately related with the formation process of these architectures. Therefore, flower-necklace-like and cauliflower-like nickel hierarchical structures were used as prototype systems to evidence the relationship between assembling patterns of primary nanoparticles and magnetic saturation behaviors of these architectures. It was found that the influence of lattice strain on saturation magnetization outperformed that of non-ferromagnetic inclusions in these hierarchical structures. This will enable new insights into fundamental understanding of related magnetic effects.

Masking effects of speech and music: does the masker's hierarchical structure matter?

Science.gov (United States)

Shi, Lu-Feng; Law, Yvonne

2010-04-01

Speech and music are time-varying signals organized by parallel hierarchical rules. Through a series of four experiments, this study compared the masking effects of single-talker speech and instrumental music on speech perception while manipulating the complexity of hierarchical and temporal structures of the maskers. Listeners' word recognition was found to be similar between hierarchically intact and disrupted speech or classical music maskers (Experiment 1). When sentences served as the signal, significantly greater masking effects were observed with disrupted than intact speech or classical music maskers (Experiment 2), although not with jazz or serial music maskers, which differed from the classical music masker in their hierarchical structures (Experiment 3). Removing the classical music masker's temporal dynamics or partially restoring it affected listeners' sentence recognition; yet, differences in performance between intact and disrupted maskers remained robust (Experiment 4). Hence, the effect of structural expectancy was largely present across maskers when comparing them before and after their hierarchical structure was purposefully disrupted. This effect seemed to lend support to the auditory stream segregation theory.

Fabrication and properties of dual-level hierarchical structures mimicking gecko foot hairs.

Science.gov (United States)

Zhang, Peng; Liu, Shiyuan; Lv, Hao

2013-02-01

In nature, geckos have extraordinary adhesive capabilities. The multi-scale hierarchical structure of the gecko foot hairs, especially the high-aspect-ratio structure of its micro-scale seta and nano-scale spatulae is the critical factor of the gecko's ability to adopt and stick to any different surface with powerful adhesion force. In this paper, we present a simple and effective approach to fabricate dual-level hierarchical structures mimicking gecko foot hairs. Polydimethyl-siloxane (PDMS) hierarchical arrays were fabricated by demolding from a double stack mold that was composed of an SU-8 mold by thick film photolithography and a silicon mold by inductively coupled plasma (ICP) etching. Top pillars of the fabricated structures have 3 micom diameter and 18 microm in height, while base pillars have 25 microm diameter and 40 microm in height. The water droplet contact angle tests indicate that the hierarchical structures increase the hydrophobic property significantly compared with the single-level arrays and the unstructured polymers, exhibiting superhydrophobicity (154.2 degrees) like the Tokay gecko's (160.9 degrees). The shear force tests show that the top pillars make attachment through side contact with a value of about 0.25 N/cm2, and moreover, the hierarchical structures are demonstrated to be more suitable for contacting with rough surfaces.

A Hierarchical Building Segmentation in Digital Surface Models for 3D Reconstruction

Directory of Open Access Journals (Sweden)

Yiming Yan

2017-01-01

Full Text Available In this study, a hierarchical method for segmenting buildings in a digital surface model (DSM, which is used in a novel framework for 3D reconstruction, is proposed. Most 3D reconstructions of buildings are model-based. However, the limitations of these methods are overreliance on completeness of the offline-constructed models of buildings, and the completeness is not easily guaranteed since in modern cities buildings can be of a variety of types. Therefore, a model-free framework using high precision DSM and texture-images buildings was introduced. There are two key problems with this framework. The first one is how to accurately extract the buildings from the DSM. Most segmentation methods are limited by either the terrain factors or the difficult choice of parameter-settings. A level-set method are employed to roughly find the building regions in the DSM, and then a recently proposed ‘occlusions of random textures model’ are used to enhance the local segmentation of the buildings. The second problem is how to generate the facades of buildings. Synergizing with the corresponding texture-images, we propose a roof-contour guided interpolation of building facades. The 3D reconstruction results achieved by airborne-like images and satellites are compared. Experiments show that the segmentation method has good performance, and 3D reconstruction is easily performed by our framework, and better visualization results can be obtained by airborne-like images, which can be further replaced by UAV images.

Preparation of disk-like particles with micro/nano hierarchical structures.

Science.gov (United States)

Meng, Zhen; Yang, Wenbo; Chen, Pengpeng; Wang, Weina; Jia, Xudong; Xi, Kai

2013-10-15

A facile, reproductive method has been successfully developed to produce disk-like microparticles self-assembled from monodispersed hybrid silica nanoparticles under certain circumstance. The disk-like microparticles with micro/nano hierarchical structures could be obtained in large amount under a mild condition and further used to biomimetic design of the superhydrophobic surface of lotus leaf. After traditional surface modification with dodecyltrichlorosiliane, the static contact angle of water on the surface with micro/nano hierarchical structure could reach 168.8°. The method of surface modification could be further simplified by click reaction with the introduction of thiol groups under mild condition. The present strategy for constructing the surface with micro/nano hierarchical structures offers the advantage of simple and large area fabrication, which enables a variety of superhydrophobic applications. Copyright © 2013 Elsevier Inc. All rights reserved.

Hierarchically nanostructured hydroxyapatite: hydrothermal synthesis, morphology control, growth mechanism, and biological activity

Directory of Open Access Journals (Sweden)

Ma MG

2012-04-01

Full Text Available Ming-Guo MaInstitute of Biomass Chemistry and Technology, College of Materials Science and Technology, Beijing Forestry University, Beijing, People's Republic of ChinaAbstract: Hierarchically nanosized hydroxyapatite (HA with flower-like structure assembled from nanosheets consisting of nanorod building blocks was successfully synthesized by using CaCl2, NaH2PO4, and potassium sodium tartrate via a hydrothermal method at 200°C for 24 hours. The effects of heating time and heating temperature on the products were investigated. As a chelating ligand and template molecule, the potassium sodium tartrate plays a key role in the formation of hierarchically nanostructured HA. On the basis of experimental results, a possible mechanism based on soft-template and self-assembly was proposed for the formation and growth of the hierarchically nanostructured HA. Cytotoxicity experiments indicated that the hierarchically nanostructured HA had good biocompatibility. It was shown by in-vitro experiments that mesenchymal stem cells could attach to the hierarchically nanostructured HA after being cultured for 48 hours.Objective: The purpose of this study was to develop facile and effective methods for the synthesis of novel hydroxyapatite (HA with hierarchical nanostructures assembled from independent and discrete nanobuilding blocks.Methods: A simple hydrothermal approach was applied to synthesize HA by using CaCl2, NaH2PO4, and potassium sodium tartrate at 200°C for 24 hours. The cell cytotoxicity of the hierarchically nanostructured HA was tested by MTT (3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide assay.Results: HA displayed the flower-like structure assembled from nanosheets consisting of nanorod building blocks. The potassium sodium tartrate was used as a chelating ligand, inducing the formation and self-assembly of HA nanorods. The heating time and heating temperature influenced the aggregation and morphology of HA. The cell viability did

Fabrication of Superhydrophobic Surface with Controlled Wetting Property by Hierarchical Particles.

Science.gov (United States)

Xu, Jianxiong; Liu, Weiwei; Du, Jingjing; Tang, Zengmin; Xu, Lijian; Li, Na

2015-04-01

Hierarchical particles were prepared by synthetically joining appropriately functionalized polystyrene spheres of poly[styrene-co-(3-(4-vinylphenyl)pentane-2,4-dione)] (PS-co-PVPD) nanoparticles and poly(styrene-co-chloromethylstyrene) (PS-co-PCMS) microparticles. The coupling reaction of nucleophilic substitution of pendent β-diketone groups with benzyl chloride was used to form the hierarchical particles. Since the polymeric nanoparticles and microparticles were synthesized by dispersion polymerization and emulsion polymerization, respectively, both the core microparticles and the surface nanoparticles can be different size and chemical composition. By means of changing the size of the PS-co-PVPD surface nanoparticles, a series of hierarchical particles with different scale ratio of the micro/nano surface structure were successfully prepared. Moreover, by employing the PS-co-PVPD microparticles and PS-co-PCMS nanoparticles as building blocks, hierarchical particles with surface nanoaprticles of different composition were made. These as-prepared hierarchical particles were subsequently assembled on glass substrates to form particulate films. Contact angle measurement shows that superhydrophobic surfaces can be obtained and the contact angle of water on the hierarchically structured surface can be adjusted by the scale ratio of the micro/nano surface structure and surface chemical component of hierarchical particles.

Hierarchical structure observation and nanoindentation size effect characterization for a limnetic shell

Science.gov (United States)

Song, Jingru; Fan, Cuncai; Ma, Hansong; Wei, Yueguang

2015-06-01

In the present research, hierarchical structure observation and mechanical property characterization for a type of biomaterial are carried out. The investigated biomaterial is Hyriopsis cumingii, a typical limnetic shell, which consists of two different structural layers, a prismatic "pillar" structure and a nacreous "brick and mortar" structure. The prismatic layer looks like a "pillar forest" with variation-section pillars sized on the order of several tens of microns. The nacreous material looks like a "brick wall" with bricks sized on the order of several microns. Both pillars and bricks are composed of nanoparticles. The mechanical properties of the hierarchical biomaterial are measured by using the nanoindentation test. Hardness and modulus are measured for both the nacre layer and the prismatic layer, respectively. The nanoindentation size effects for the hierarchical structural materials are investigated experimentally. The results show that the prismatic nanostructured material has a higher stiffness and hardness than the nacre nanostructured material. In addition, the nanoindentation size effects for the hierarchical structural materials are described theoretically, by using the trans-scale mechanics theory considering both strain gradient effect and the surface/interface effect. The modeling results are consistent with experimental ones.

Additive Manufacturing of Hierarchical Porous Structures

Energy Technology Data Exchange (ETDEWEB)

Grote, Christopher John [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Materials Science and Technology Division. Polymers and Coatings

2016-08-30

Additive manufacturing has become a tool of choice for the development of customizable components. Developments in this technology have led to a powerful array of printers that t serve a variety of needs. However, resin development plays a crucial role in leading the technology forward. This paper addresses the development and application of printing hierarchical porous structures. Beginning with the development of a porous scaffold, which can be functionalized with a variety of materials, and concluding with customized resins for metal, ceramic, and carbon structures.

Band structures of two dimensional solid/air hierarchical phononic crystals

Energy Technology Data Exchange (ETDEWEB)

Xu, Y.L.; Tian, X.G. [State Key Laboratory for Mechanical Structure Strength and Vibration, Xi' an Jiaotong University, Xi' an 710049 (China); Chen, C.Q., E-mail: chencq@tsinghua.edu.cn [Department of Engineering Mechanics, AML and CNMM, Tsinghua University, Beijing 100084 (China)

2012-06-15

The hierarchical phononic crystals to be considered show a two-order 'hierarchical' feature, which consists of square array arranged macroscopic periodic unit cells with each unit cell itself including four sub-units. Propagation of acoustic wave in such two dimensional solid/air phononic crystals is investigated by the finite element method (FEM) with the Bloch theory. Their band structure, wave filtering property, and the physical mechanism responsible for the broadened band gap are explored. The corresponding ordinary phononic crystal without hierarchical feature is used for comparison. Obtained results show that the solid/air hierarchical phononic crystals possess tunable outstanding band gap features, which are favorable for applications such as sound insulation and vibration attenuation.

Hierarchical structure graphitic-like/MoS2 film as superlubricity material

Science.gov (United States)

Gong, Zhenbin; Jia, Xiaolong; Ma, Wei; Zhang, Bin; Zhang, Junyan

2017-08-01

Friction and wear result in a great amount of energy loss and the invalidation of mechanical parts, thus it is necessary to minimize friction in practical application. In this study, the graphitic-like/MoS2 films with hierarchical structure were synthesized by the combination of pulse current plasma chemical-vapor deposition and medium frequency unbalanced magnetron sputtering in preheated environment. This hierarchical structure composite with multilayer nano sheets endows the films excellent tribological performance, which easily achieves macro superlubricity (friction coefficient ∼0.004) under humid air. Furthermore, it is expected that hierarchical structure of graphitic-like/MoS2 films could match the requirements of large scale, high bear-capacity and wear-resistance of actual working conditions, which could be widely used in the industrial production as a promising superlubricity material.

Three Ways to Link Merge with Hierarchical Concept-Combination

Directory of Open Access Journals (Sweden)

Chris Thornton

2016-11-01

Full Text Available In the Minimalist Program, language competence is seen to stem from a fundamental ability to construct hierarchical structure, an operation dubbed ‘Merge’. This raises the problem of how to view hierarchical concept-combination. This is a conceptual operation which also builds hierarchical structure. We can conceive of a garden that consists of a lawn and a flower-bed, for example, or a salad consisting of lettuce, fennel and rocket, or a crew consisting of a pilot and engineer. In such cases, concepts are put together in a way that makes one the accommodating element with respect to the others taken in combination. The accommodating element becomes the root of a hierarchical unit. Since this unit is itself a concept, the operation is inherently recursive. Does this mean the mind has two independent systems of hierarchical construction? Or is some form of integration more likely? Following a detailed examination of the operations involved, this paper shows there are three main ways in which Merge might be linked to hierarchical concept-combination. Also examined are the architectural implications that arise in each case.

Action detection by double hierarchical multi-structure space-time statistical matching model

Science.gov (United States)

Han, Jing; Zhu, Junwei; Cui, Yiyin; Bai, Lianfa; Yue, Jiang

2018-03-01

Aimed at the complex information in videos and low detection efficiency, an actions detection model based on neighboring Gaussian structure and 3D LARK features is put forward. We exploit a double hierarchical multi-structure space-time statistical matching model (DMSM) in temporal action localization. First, a neighboring Gaussian structure is presented to describe the multi-scale structural relationship. Then, a space-time statistical matching method is proposed to achieve two similarity matrices on both large and small scales, which combines double hierarchical structural constraints in model by both the neighboring Gaussian structure and the 3D LARK local structure. Finally, the double hierarchical similarity is fused and analyzed to detect actions. Besides, the multi-scale composite template extends the model application into multi-view. Experimental results of DMSM on the complex visual tracker benchmark data sets and THUMOS 2014 data sets show the promising performance. Compared with other state-of-the-art algorithm, DMSM achieves superior performances.

Transfer printing of 3D hierarchical gold structures using a sequentially imprinted polymer stamp

International Nuclear Information System (INIS)

Zhang Fengxiang; Low, Hong Yee

2008-01-01

Complex three-dimensional (3D) hierarchical structures on polymeric materials are fabricated through a process referred to as sequential imprinting. In this work, the sequentially imprinted polystyrene film is used as a soft stamp to replicate hierarchical structures onto gold (Au) films, and the Au structures are then transferred to a substrate by transfer printing at an elevated temperature and pressure. Continuous and isolated 3D structures can be selectively fabricated with the assistance of thermo-mechanical deformation of the polymer stamp. Hierarchical Au structures are achieved without the need for a corresponding three-dimensionally patterned mold

Fabrication of semi-transparent super-hydrophobic surface based on silica hierarchical structures

KAUST Repository

Chen, Ping-Hei

2011-01-01

This study successfully develops a versatile method of producing superhydrophobic surfaces with micro/nano-silica hierarchical structures on glass surfaces. Optically transparent super hydrophobic silica thin films were prepared by spin-coating silica particles suspended in a precursor solution of silane, ethanol, and H2O with molar ratio of 1:4:4. The resulting super hydrophobic films were characterized by scanning electron microscopy (SEM), optical transmission, and contact angle measurements. The glass substrates in this study were modified with different particles: micro-silica particles, nano-silica particles, and hierarchical structures. This study includes SEM micrographs of the modified glass surfaces with hierarchical structures at different magnifications. © 2011 The Korean Society of Mechanical Engineers and Springer-Verlag Berlin Heidelberg.

Fabrication and condensation characteristics of metallic superhydrophobic surface with hierarchical micro-nano structures

Science.gov (United States)

Chu, Fuqiang; Wu, Xiaomin

2016-05-01

Metallic superhydrophobic surfaces have various applications in aerospace, refrigeration and other engineering fields due to their excellent water repellent characteristics. This study considers a simple but widely applicable fabrication method using a two simultaneous chemical reactions method to prepare the acid-salt mixed solutions to process the metal surfaces with surface deposition and surface etching to construct hierarchical micro-nano structures on the surface and then modify the surface with low surface-energy materials. Al-based and Cu-based superhydrophobic surfaces were fabricated using this method. The Al-based superhydrophobic surface had a water contact angle of 164° with hierarchical micro-nano structures similar to the lotus leaves. The Cu-based surface had a water contact angle of 157° with moss-like hierarchical micro-nano structures. Droplet condensation experiments were also performed on these two superhydrophobic surfaces to investigate their condensation characteristics. The results show that the Al-based superhydrophobic surface has lower droplet density, higher droplet jumping probability, slower droplet growth rate and lower surface coverage due to the more structured hierarchical structures.

Dielectric study on hierarchical water structures restricted in cement and wood materials

International Nuclear Information System (INIS)

Abe, Fumiya; Nishi, Akihiro; Saito, Hironobu; Asano, Megumi; Watanabe, Seiei; Kita, Rio; Shinyashiki, Naoki; Yagihara, Shin; Fukuzaki, Minoru; Sudo, Seiichi; Suzuki, Youki

2017-01-01

Dielectric relaxation processes for mortar observed by broadband dielectric spectroscopy were analyzed in the drying and hydration processes for an aging sample in the frequency region from 1 MHz up to 2 MHz. At least two processes for structured water in the kHz frequency region and another mHz relaxation process affected by ionic behaviors were observed. Comparison of the relaxation parameters obtained for the drying and hydration processes suggests an existence of hierarchical water structures in the exchange of water molecules, which are originally exchanged from free water observed at around 20 GHz. The water molecules reflected in the lower frequency process of the two kHz relaxation processes are more restricted and take more homogeneous structures than the higher kHz relaxation process. These structured water usually hidden in large ionic behaviors for wood samples was observed by electrodes covered by a thin Teflon film, and hierarchical water structures were also suggested for wood samples. Dielectric spectroscopy technique is an effective tool to analyze the new concept of hierarchical water structures in complex materials. (paper)

Modern frame structure buildings

Directory of Open Access Journals (Sweden)

В. М. Першаков

2013-07-01

Full Text Available The article deals with the design, construction and implementation of reinforced concrete frame structures with span 18, 21 m for agricultural production buildings, hall-premises of public buildings and buildings of agricultural aviation. Structures are prefabricated frame buildings and have such advantages as large space inside the structure and lower cost compared with other facilities with same purpose

Hierarchical modular structure enhances the robustness of self-organized criticality in neural networks

International Nuclear Information System (INIS)

Wang Shengjun; Zhou Changsong

2012-01-01

One of the most prominent architecture properties of neural networks in the brain is the hierarchical modular structure. How does the structure property constrain or improve brain function? It is thought that operating near criticality can be beneficial for brain function. Here, we find that networks with modular structure can extend the parameter region of coupling strength over which critical states are reached compared to non-modular networks. Moreover, we find that one aspect of network function—dynamical range—is highest for the same parameter region. Thus, hierarchical modularity enhances robustness of criticality as well as function. However, too much modularity constrains function by preventing the neural networks from reaching critical states, because the modular structure limits the spreading of avalanches. Our results suggest that the brain may take advantage of the hierarchical modular structure to attain criticality and enhanced function. (paper)

Three-Dimensional ZnO Hierarchical Nanostructures: Solution Phase Synthesis and Applications

Directory of Open Access Journals (Sweden)

Xiaoliang Wang

2017-11-01

Full Text Available Zinc oxide (ZnO nanostructures have been studied extensively in the past 20 years due to their novel electronic, photonic, mechanical and electrochemical properties. Recently, more attention has been paid to assemble nanoscale building blocks into three-dimensional (3D complex hierarchical structures, which not only inherit the excellent properties of the single building blocks but also provide potential applications in the bottom-up fabrication of functional devices. This review article focuses on 3D ZnO hierarchical nanostructures, and summarizes major advances in the solution phase synthesis, applications in environment, and electrical/electrochemical devices. We present the principles and growth mechanisms of ZnO nanostructures via different solution methods, with an emphasis on rational control of the morphology and assembly. We then discuss the applications of 3D ZnO hierarchical nanostructures in photocatalysis, field emission, electrochemical sensor, and lithium ion batteries. Throughout the discussion, the relationship between the device performance and the microstructures of 3D ZnO hierarchical nanostructures will be highlighted. This review concludes with a personal perspective on the current challenges and future research.

Multiphase static droplet simulations in hierarchically structured super-hydrophobic surfaces

Energy Technology Data Exchange (ETDEWEB)

Lee, Jung Shin; Lee, Joon Sang [School of Mechanical Engineering, Yonsei University, Seoul (Korea, Republic of)

2016-08-15

The surface of first part of study is textured with microscopic pillars of prototypical top geometries as a rectangle. The second one is textured with a hierarchical structure, composed of secondary pillar structures added on the primary texture. The length ratio between two scales of texture is 1:16. We evaluated the non-wetting characteristics of two types of surfaces by measuring CAs as well as the transition from the Wenzel's to Cassie's regimes. We measure the Contact angles (CAs), using the Lattice Boltzmann model (LBM), for two different surface configurations. We evaluated the effect of the hierarchical structure; the robustness of the Cassie regime is enhanced and the apparent contact angle is increased by the secondary structures. This is achieved by increasing the energy barrier against the transition between wetting and non-wetting regimes.

Hierarchical modeling of indoor radon concentration: how much do geology and building factors matter?

Science.gov (United States)

Borgoni, Riccardo; De Francesco, Davide; De Bartolo, Daniela; Tzavidis, Nikos

2014-12-01

Radon is a natural gas known to be the main contributor to natural background radiation exposure and only second to smoking as major leading cause of lung cancer. The main concern is in indoor environments where the gas tends to accumulate and can reach high concentrations. The primary contributor of this gas into the building is from the soil although architectonic characteristics, such as building materials, can largely affect concentration values. Understanding the factors affecting the concentration in dwellings and workplaces is important both in prevention, when the construction of a new building is being planned, and in mitigation when the amount of Radon detected inside a building is too high. In this paper we investigate how several factors, such as geologic typologies of the soil and a range of building characteristics, impact on indoor concentration focusing, in particular, on how concentration changes as a function of the floor level. Adopting a mixed effects model to account for the hierarchical nature of the data, we also quantify the extent to which such measurable factors manage to explain the variability of indoor radon concentration. Copyright © 2014 Elsevier Ltd. All rights reserved.

Band structures of two dimensional solid/air hierarchical phononic crystals

International Nuclear Information System (INIS)

Xu, Y.L.; Tian, X.G.; Chen, C.Q.

2012-01-01

The hierarchical phononic crystals to be considered show a two-order “hierarchical” feature, which consists of square array arranged macroscopic periodic unit cells with each unit cell itself including four sub-units. Propagation of acoustic wave in such two dimensional solid/air phononic crystals is investigated by the finite element method (FEM) with the Bloch theory. Their band structure, wave filtering property, and the physical mechanism responsible for the broadened band gap are explored. The corresponding ordinary phononic crystal without hierarchical feature is used for comparison. Obtained results show that the solid/air hierarchical phononic crystals possess tunable outstanding band gap features, which are favorable for applications such as sound insulation and vibration attenuation.

Hierarchical structure of the otolith of adult wild carp

International Nuclear Information System (INIS)

Li Zhuo; Gao Yonghua; Feng Qingling

2009-01-01

The otolith of adult wild carp contains a pair of asterisci, a pair of lappilli and a pair of sagittae. Current research works are mainly restricted to the field of the daily ring structure. The purpose of this work is to explore the structural characteristics of carp's otolith in terms of hierarchy from nanometer to millimeter scale by transmission election microscope (TEM) and scanning electron microscope (SEM). Based on the observation, carp's lapillus is composed of ordered aragonite crystals. Seven hierarchical levels of the microstructure were proposed and described with the scheme representing a complete organization in detail. SEM studies show not only the clear daily growth increment, but also the morphology within the single daily increment. The domain structure of crystal orientation in otolith was observed for the first time. Furthermore, TEM investigation displays that the lapillus is composed of aragonite crystals with nanometer scale. Four hierarchical levels of the microstructure of the sagitta are also proposed. The asteriscus which is composed of nanometer scale vaterite crystals is considered to have a uniform structure.

Hierarchical structure of the otolith of adult wild carp

Energy Technology Data Exchange (ETDEWEB)

Li Zhuo; Gao Yonghua [State key laboratory of new ceramics and fine processing, Department of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Feng Qingling, E-mail: biomater@mail.tsinghua.edu.cn [State key laboratory of new ceramics and fine processing, Department of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China)

2009-04-30

The otolith of adult wild carp contains a pair of asterisci, a pair of lappilli and a pair of sagittae. Current research works are mainly restricted to the field of the daily ring structure. The purpose of this work is to explore the structural characteristics of carp's otolith in terms of hierarchy from nanometer to millimeter scale by transmission election microscope (TEM) and scanning electron microscope (SEM). Based on the observation, carp's lapillus is composed of ordered aragonite crystals. Seven hierarchical levels of the microstructure were proposed and described with the scheme representing a complete organization in detail. SEM studies show not only the clear daily growth increment, but also the morphology within the single daily increment. The domain structure of crystal orientation in otolith was observed for the first time. Furthermore, TEM investigation displays that the lapillus is composed of aragonite crystals with nanometer scale. Four hierarchical levels of the microstructure of the sagitta are also proposed. The asteriscus which is composed of nanometer scale vaterite crystals is considered to have a uniform structure.

Hierarchical structure of biological systems: a bioengineering approach.

Science.gov (United States)

Alcocer-Cuarón, Carlos; Rivera, Ana L; Castaño, Victor M

2014-01-01

A general theory of biological systems, based on few fundamental propositions, allows a generalization of both Wierner and Berthalanffy approaches to theoretical biology. Here, a biological system is defined as a set of self-organized, differentiated elements that interact pair-wise through various networks and media, isolated from other sets by boundaries. Their relation to other systems can be described as a closed loop in a steady-state, which leads to a hierarchical structure and functioning of the biological system. Our thermodynamical approach of hierarchical character can be applied to biological systems of varying sizes through some general principles, based on the exchange of energy information and/or mass from and within the systems.

A thick hierarchical rutile TiO2 nanomaterial with multilayered structure

International Nuclear Information System (INIS)

Zhu, Shengli; Xie, Guoqiang; Yang, Xianjin; Cui, Zhenduo

2013-01-01

Highlights: ► We synthesized a new rutile TiO 2 nanomaterial with a hierarchical nanostructure. ► The nano architecture structure consist of nanorods and nanoflower arrays. ► The rutile TiO 2 nanomaterial is thick in size (several 10 μm). ► The TiO 2 nanomaterials present a multilayer structure. - Abstract: In the present paper, we synthesized a new type of rutile TiO 2 nanomaterial with a hierarchical nanostructure using a novel method, which combined dealloying process with chemical synthesis. The structure characters were examined using X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The rutile TiO 2 nanomaterial is thick in size (several 10 μm). The hierarchical structure of the rutile TiO 2 nanomaterial consists of large quantities nanorods and nanoflower arrays. The nanoflowers consist of serveral nanopetals with diameter of 100–200 nm. The cross section of TiO 2 nanomaterials presents a multilayer structure with the layer thickness of about 3–5 μm. The rutile TiO 2 nanomaterial has high specific surface area. The formation mechanism of the rutile TiO 2 nanomaterial was discussed according to the experimental results. The rutile TiO 2 nanomaterial has potential applications in catalysis, photocatalysis and solar cells

Micro-nanofibers with hierarchical structure by bubbfil-spinning

Directory of Open Access Journals (Sweden)

Liu Peng

2015-01-01

Full Text Available Bubbfil spinning is used to fabricate micro/nanofibers with hierarchical structure. The wall of a polymer film is attenuated unevenly by a blowing air. The burst of the bubble results in film fragments with different thickness, as a result, different sizes of fibers are obtained.

The well-designed hierarchical structure of Musa basjoo for supercapacitors

Science.gov (United States)

Zheng, Kaiwen; Fan, Xiaorong; Mao, Yingzhu; Lin, Jingkai; Dai, Wenxuan; Zhang, Junying; Cheng, Jue

2016-01-01

Application of biological structure is one of the hottest topics in the field of science and technology. The unimaginable and excellent architectures of living beings supporting their vital activities have attracted the interests of worldwide researchers. An intriguing example is Musa basjoo which belongs to the herb, while appears like a tree. The profound mystery of structure and potential application of Musa basjoo have not been probed. Here we show the finding of the hierarchical structure of Musa basjoo and the outstanding electrochemical performance of the super-capacitors fabricated through the simple carbonization of Musa basjoo followed by KOH activation. Musa basjoo has three layers of structure: nanometer-level, micrometer-level and millimeter-level. The nanometer-level structure constructs the micrometer-level structure, while the micrometer-level structure constructs the millimeter-level structure. Based on this hierarchical structure, Musa basjoo reduces the unnecessary weight and therefore supports its huge body. The super-capacitors derived from Musa basjoo display a high specific capacitance and a good cycling stability. This enlightening work opens a window for the applications of the natural structure and we hope that more and more people could pay attention to the bio-inspired materials. PMID:26842714

The well-designed hierarchical structure of Musa basjoo for supercapacitors

Science.gov (United States)

Zheng, Kaiwen; Fan, Xiaorong; Mao, Yingzhu; Lin, Jingkai; Dai, Wenxuan; Zhang, Junying; Cheng, Jue

2016-02-01

Application of biological structure is one of the hottest topics in the field of science and technology. The unimaginable and excellent architectures of living beings supporting their vital activities have attracted the interests of worldwide researchers. An intriguing example is Musa basjoo which belongs to the herb, while appears like a tree. The profound mystery of structure and potential application of Musa basjoo have not been probed. Here we show the finding of the hierarchical structure of Musa basjoo and the outstanding electrochemical performance of the super-capacitors fabricated through the simple carbonization of Musa basjoo followed by KOH activation. Musa basjoo has three layers of structure: nanometer-level, micrometer-level and millimeter-level. The nanometer-level structure constructs the micrometer-level structure, while the micrometer-level structure constructs the millimeter-level structure. Based on this hierarchical structure, Musa basjoo reduces the unnecessary weight and therefore supports its huge body. The super-capacitors derived from Musa basjoo display a high specific capacitance and a good cycling stability. This enlightening work opens a window for the applications of the natural structure and we hope that more and more people could pay attention to the bio-inspired materials.

Hierarchical structure for audio-video based semantic classification of sports video sequences

Science.gov (United States)

Kolekar, M. H.; Sengupta, S.

2005-07-01

A hierarchical structure for sports event classification based on audio and video content analysis is proposed in this paper. Compared to the event classifications in other games, those of cricket are very challenging and yet unexplored. We have successfully solved cricket video classification problem using a six level hierarchical structure. The first level performs event detection based on audio energy and Zero Crossing Rate (ZCR) of short-time audio signal. In the subsequent levels, we classify the events based on video features using a Hidden Markov Model implemented through Dynamic Programming (HMM-DP) using color or motion as a likelihood function. For some of the game-specific decisions, a rule-based classification is also performed. Our proposed hierarchical structure can easily be applied to any other sports. Our results are very promising and we have moved a step forward towards addressing semantic classification problems in general.

Delineating the structure of normal and abnormal personality: an integrative hierarchical approach.

Science.gov (United States)

Markon, Kristian E; Krueger, Robert F; Watson, David

2005-01-01

Increasing evidence indicates that normal and abnormal personality can be treated within a single structural framework. However, identification of a single integrated structure of normal and abnormal personality has remained elusive. Here, a constructive replication approach was used to delineate an integrative hierarchical account of the structure of normal and abnormal personality. This hierarchical structure, which integrates many Big Trait models proposed in the literature, replicated across a meta-analysis as well as an empirical study, and across samples of participants as well as measures. The proposed structure resembles previously suggested accounts of personality hierarchy and provides insight into the nature of personality hierarchy more generally. Potential directions for future research on personality and psychopathology are discussed.

Delineating the Structure of Normal and Abnormal Personality: An Integrative Hierarchical Approach

Science.gov (United States)

Markon, Kristian E.; Krueger, Robert F.; Watson, David

2008-01-01

Increasing evidence indicates that normal and abnormal personality can be treated within a single structural framework. However, identification of a single integrated structure of normal and abnormal personality has remained elusive. Here, a constructive replication approach was used to delineate an integrative hierarchical account of the structure of normal and abnormal personality. This hierarchical structure, which integrates many Big Trait models proposed in the literature, replicated across a meta-analysis as well as an empirical study, and across samples of participants as well as measures. The proposed structure resembles previously suggested accounts of personality hierarchy and provides insight into the nature of personality hierarchy more generally. Potential directions for future research on personality and psychopathology are discussed. PMID:15631580

CTAB-Assisted Hydrothermal Synthesis of WO3 Hierarchical Porous Structures and Investigation of Their Sensing Properties

Directory of Open Access Journals (Sweden)

Dan Meng

2015-01-01

Full Text Available WO3 hierarchical porous structures were successfully synthesized via cetyltrimethylammonium bromide- (CTAB- assisted hydrothermal method. The structure and morphology were investigated using scanning electron microscope, X-ray diffractometer, transmission electron microscopy, X-ray photoelectron spectra, Brunauer-Emmett-Teller nitrogen adsorption-desorption, and thermogravimetry and differential thermal analysis. The result demonstrated that WO3 hierarchical porous structures with an orthorhombic structure were constructed by a number of nanoparticles about 50–100 nm in diameters. The H2 gas sensing measurements showed that well-defined WO3 hierarchical porous structures with a large specific surface area exhibited the higher sensitivity compared with products without CTAB at all operating temperatures. Moreover, the reversible and fast response to H2 gas and good selectivity were obtained. The results indicated that the WO3 hierarchical porous structures are promising materials for gas sensors.

Hierarchical structures of ZnO spherical particles synthesized solvothermally

Science.gov (United States)

Saito, Noriko; Haneda, Hajime

2011-12-01

We review the solvothermal synthesis, using a mixture of ethylene glycol (EG) and water as the solvent, of zinc oxide (ZnO) particles having spherical and flower-like shapes and hierarchical nanostructures. The preparation conditions of the ZnO particles and the microscopic characterization of the morphology are summarized. We found the following three effects of the ratio of EG to water on the formation of hierarchical structures: (i) EG restricts the growth of ZnO microcrystals, (ii) EG promotes the self-assembly of small crystallites into spheroidal particles and (iii) the high water content of EG results in hollow spheres.

Hierarchical ZnO with twinned structure: Morphology evolution, formation mechanism and properties

International Nuclear Information System (INIS)

Shi, Ruixia; Song, Xueling; Li, Jia; Yang, Ping

2015-01-01

Various hierarchical ZnO architectures constructed by twinned structures have been synthesized via a trisodium citrate assisted hydrothermal method on a large scale. The probable formation mechanisms of hierarchical ZnO structures with twinned structure were proposed and discussed. The hierarchical ZnO with twinned structures are composed of two hemispheres with a center concave junction to join them together at their waists. The ZnO microspheres with rough surfaces were obtained when the concentration of trisodium citrate is 0.1 M. However, the football-like microspheres consisted of hexagonal nanosheets were formed when adding glycerol into the water, which should be attributed to the slower nucleation and growth rate of nanocrystals. The hamburger-like ZnO with different aspect ratio and nonuniform ZnO microspheres were generated due to the different quantity of initial nuclei and growth units when simply modulating the concentration of trisodium citrate. The surface area of football-like ZnO is about 3.51 times of microspheres composed of irregular particles. However their photocatalytic performances are similar under UV light irradiation, which indicates that pore sizes of the sample have more important influences on the photocatalytic activity. - Highlights: • Hierarchical ZnO constructed by twinned structures have been synthesized. • The formation mechanisms of ZnO with twinned structure were discussed. • Football-like microspheres were obtained due to the slower nucleation and growth. • Hamburger-like ZnO was formed due to the amount of initial nuclei and growth units. • Pore sizes have important effects on the photocatalytic activity of sample

Hierarchical ZnO with twinned structure: Morphology evolution, formation mechanism and properties

Energy Technology Data Exchange (ETDEWEB)

Shi, Ruixia; Song, Xueling; Li, Jia; Yang, Ping, E-mail: mse_yangp@ujn.edu.cn

2015-04-15

Various hierarchical ZnO architectures constructed by twinned structures have been synthesized via a trisodium citrate assisted hydrothermal method on a large scale. The probable formation mechanisms of hierarchical ZnO structures with twinned structure were proposed and discussed. The hierarchical ZnO with twinned structures are composed of two hemispheres with a center concave junction to join them together at their waists. The ZnO microspheres with rough surfaces were obtained when the concentration of trisodium citrate is 0.1 M. However, the football-like microspheres consisted of hexagonal nanosheets were formed when adding glycerol into the water, which should be attributed to the slower nucleation and growth rate of nanocrystals. The hamburger-like ZnO with different aspect ratio and nonuniform ZnO microspheres were generated due to the different quantity of initial nuclei and growth units when simply modulating the concentration of trisodium citrate. The surface area of football-like ZnO is about 3.51 times of microspheres composed of irregular particles. However their photocatalytic performances are similar under UV light irradiation, which indicates that pore sizes of the sample have more important influences on the photocatalytic activity. - Highlights: • Hierarchical ZnO constructed by twinned structures have been synthesized. • The formation mechanisms of ZnO with twinned structure were discussed. • Football-like microspheres were obtained due to the slower nucleation and growth. • Hamburger-like ZnO was formed due to the amount of initial nuclei and growth units. • Pore sizes have important effects on the photocatalytic activity of sample.

D Nearest Neighbour Search Using a Clustered Hierarchical Tree Structure

Science.gov (United States)

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

2016-06-01

Locating and analysing the location of new stores or outlets is one of the common issues facing retailers and franchisers. This is due to assure that new opening stores are at their strategic location to attract the highest possible number of customers. Spatial information is used to manage, maintain and analyse these store locations. However, since the business of franchising and chain stores in urban areas runs within high rise multi-level buildings, a three-dimensional (3D) method is prominently required in order to locate and identify the surrounding information such as at which level of the franchise unit will be located or is the franchise unit located is at the best level for visibility purposes. One of the common used analyses used for retrieving the surrounding information is Nearest Neighbour (NN) analysis. It uses a point location and identifies the surrounding neighbours. However, with the immense number of urban datasets, the retrieval and analysis of nearest neighbour information and their efficiency will become more complex and crucial. In this paper, we present a technique to retrieve nearest neighbour information in 3D space using a clustered hierarchical tree structure. Based on our findings, the proposed approach substantially showed an improvement of response time analysis compared to existing approaches of spatial access methods in databases. The query performance was tested using a dataset consisting of 500,000 point locations building and franchising unit. The results are presented in this paper. Another advantage of this structure is that it also offers a minimal overlap and coverage among nodes which can reduce repetitive data entry.

A new hierarchical method to find community structure in networks

Science.gov (United States)

Saoud, Bilal; Moussaoui, Abdelouahab

2018-04-01

Community structure is very important to understand a network which represents a context. Many community detection methods have been proposed like hierarchical methods. In our study, we propose a new hierarchical method for community detection in networks based on genetic algorithm. In this method we use genetic algorithm to split a network into two networks which maximize the modularity. Each new network represents a cluster (community). Then we repeat the splitting process until we get one node at each cluster. We use the modularity function to measure the strength of the community structure found by our method, which gives us an objective metric for choosing the number of communities into which a network should be divided. We demonstrate that our method are highly effective at discovering community structure in both computer-generated and real-world network data.

Self-assembly and optically triggered disassembly of hierarchical dendron-virus complexes

NARCIS (Netherlands)

Kostiainen, Mauri A.; Kasyutich, Oksana; Cornelissen, Jeroen Johannes Lambertus Maria; Nolte, Roeland J.M.

2010-01-01

Nature offers a vast array of biological building blocks that can be combined with synthetic materials to generate a variety of hierarchical architectures. Viruses are particularly interesting in this respect because of their structure and the possibility of them functioning as scaffolds for the

Hierarchical fiber-optic-based sensing system: impact damage monitoring of large-scale CFRP structures

International Nuclear Information System (INIS)

Minakuchi, Shu; Banshoya, Hidehiko; Takeda, Nobuo; Tsukamoto, Haruka

2011-01-01

This study proposes a novel fiber-optic-based hierarchical sensing concept for monitoring randomly induced damage in large-scale composite structures. In a hierarchical system, several kinds of specialized devices are hierarchically combined to form a sensing network. Specifically, numerous three-dimensionally structured sensor devices are distributed throughout the whole structural area and connected with an optical fiber network through transducing mechanisms. The distributed devices detect damage, and the fiber-optic network gathers the damage signals and transmits the information to a measuring instrument. This study began by discussing the basic concept of a hierarchical sensing system through comparison with existing fiber-optic-based systems, and an impact damage detection system was then proposed to validate the new concept. The sensor devices were developed based on comparative vacuum monitoring (CVM), and Brillouin-based distributed strain measurement was utilized to identify damaged areas. Verification tests were conducted step-by-step, beginning with a basic test using a single sensor unit, and, finally, the proposed monitoring system was successfully verified using a carbon fiber reinforced plastic (CFRP) fuselage demonstrator. It was clearly confirmed that the hierarchical system has better repairability, higher robustness, and a wider monitorable area compared to existing systems

Substrate dependent hierarchical structures of RF sputtered ZnS films

Science.gov (United States)

Chalana, S. R.; Mahadevan Pillai, V. P.

2018-05-01

RF magnetron sputtering technique was employed to fabricate ZnS nanostructures with special emphasis given to study the effect of substrates (quartz, glass and quartz substrate pre-coated with Au, Ag, Cu and Pt) on the structure, surface evolution and optical properties. Type of substrate has a significant influence on the crystalline phase, film morphology, thickness and surface roughness. The present study elucidates the suitability of quartz substrate for the deposition of stable and highly crystalline ZnS films. We found that the role of metal layer on quartz substrate is substantial in the preparation of hierarchical ZnS structures and these structures are of great importance due to its high specific area and potential applications in various fields. A mechanism for morphological evolution of ZnS structures is also presented based on the roughness of substrates and primary nonlocal effects in sputtering. Furthermore, the findings suggest that a controlled growth of hierarchical ZnS structures may be achieved with an ordinary RF sputtering technique by changing the substrate type.

Hierarchical modeling of indoor radon concentration: how much do geology and building factors matter?

International Nuclear Information System (INIS)

Borgoni, Riccardo; De Francesco, Davide; De Bartolo, Daniela; Tzavidis, Nikos

2014-01-01

Radon is a natural gas known to be the main contributor to natural background radiation exposure and only second to smoking as major leading cause of lung cancer. The main concern is in indoor environments where the gas tends to accumulate and can reach high concentrations. The primary contributor of this gas into the building is from the soil although architectonic characteristics, such as building materials, can largely affect concentration values. Understanding the factors affecting the concentration in dwellings and workplaces is important both in prevention, when the construction of a new building is being planned, and in mitigation when the amount of Radon detected inside a building is too high. In this paper we investigate how several factors, such as geologic typologies of the soil and a range of building characteristics, impact on indoor concentration focusing, in particular, on how concentration changes as a function of the floor level. Adopting a mixed effects model to account for the hierarchical nature of the data, we also quantify the extent to which such measurable factors manage to explain the variability of indoor radon concentration. - Highlights: • It is assessed how the variability of indoor radon concentration depends on buildings and lithologies. • The lithological component has been found less relevant than the building one. • Radon-prone lithologies have been identified. • The effect of the floor where the room is located has been estimated. • Indoor radon concentration have been predicted for different dwelling typologies

Nanomechanical strength mechanisms of hierarchical biological materials and tissues.

Science.gov (United States)

Buehler, Markus J; Ackbarow, Theodor

2008-12-01

Biological protein materials (BPMs), intriguing hierarchical structures formed by assembly of chemical building blocks, are crucial for critical functions of life. The structural details of BPMs are fascinating: They represent a combination of universally found motifs such as alpha-helices or beta-sheets with highly adapted protein structures such as cytoskeletal networks or spider silk nanocomposites. BPMs combine properties like strength and robustness, self-healing ability, adaptability, changeability, evolvability and others into multi-functional materials at a level unmatched in synthetic materials. The ability to achieve these properties depends critically on the particular traits of these materials, first and foremost their hierarchical architecture and seamless integration of material and structure, from nano to macro. Here, we provide a brief review of this field and outline new research directions, along with a review of recent research results in the development of structure-property relationships of biological protein materials exemplified in a study of vimentin intermediate filaments.

Thermodynamic analysis on an anisotropically superhydrophobic surface with a hierarchical structure

Energy Technology Data Exchange (ETDEWEB)

Zhao, Jieliang [Division of Intelligent and Biomechanical Systems, State Key Laboratory of Tribology, Tsinghua University, Room 3407, Building 9003, 100084 Beijing (China); Su, Zhengliang [Division of Intelligent and Biomechanical Systems, State Key Laboratory of Tribology, Tsinghua University, Room 3407, Building 9003, 100084 Beijing (China); Department of Automotive Engineering, Tsinghua University, Beijing 100084 (China); Yan, Shaoze, E-mail: yansz@mail.tsinghua.edu.cn [Division of Intelligent and Biomechanical Systems, State Key Laboratory of Tribology, Tsinghua University, Room 3407, Building 9003, 100084 Beijing (China)

2015-12-01

Graphical abstract: - Highlights: • We model the superhydrophobic surface with anisotropic and hierarchical structure. • Anisotropic wetting only shows in noncomposite state (not in composite state). • Transition from noncomposite to composite state on dual-scale structure is hard. • Droplets tend to roll in the particular direction. • Droplets tend to stably remain in one preferred thermodynamic state. - Abstract: Superhydrophobic surfaces, which refer to the surfaces with contact angle higher than 150° and hysteresis less than 10°, have been reported in various studies. However, studies on the superhydrophobicity of anisotropic, hierarchical surfaces are limited and the corresponding thermodynamic mechanisms could not be explained thoroughly. Here we propose a simplified surface model of anisotropic patterned surface with dual scale roughness. Based on the thermodynamic method, we calculate the equilibrium contact angle (ECA) and the contact angle hysteresis (CAH) on the given surface. We show here that the hierarchical structure has much better anisotropic wetting properties than the single-scale one, and the results shed light on the potential application in controllable micro-/nano-fluidic systems. Our studies can be potentially applied for the fabrication of anisotropically superhydrophobic surfaces.

Thermodynamic analysis on an anisotropically superhydrophobic surface with a hierarchical structure

International Nuclear Information System (INIS)

Zhao, Jieliang; Su, Zhengliang; Yan, Shaoze

2015-01-01

Graphical abstract: - Highlights: • We model the superhydrophobic surface with anisotropic and hierarchical structure. • Anisotropic wetting only shows in noncomposite state (not in composite state). • Transition from noncomposite to composite state on dual-scale structure is hard. • Droplets tend to roll in the particular direction. • Droplets tend to stably remain in one preferred thermodynamic state. - Abstract: Superhydrophobic surfaces, which refer to the surfaces with contact angle higher than 150° and hysteresis less than 10°, have been reported in various studies. However, studies on the superhydrophobicity of anisotropic, hierarchical surfaces are limited and the corresponding thermodynamic mechanisms could not be explained thoroughly. Here we propose a simplified surface model of anisotropic patterned surface with dual scale roughness. Based on the thermodynamic method, we calculate the equilibrium contact angle (ECA) and the contact angle hysteresis (CAH) on the given surface. We show here that the hierarchical structure has much better anisotropic wetting properties than the single-scale one, and the results shed light on the potential application in controllable micro-/nano-fluidic systems. Our studies can be potentially applied for the fabrication of anisotropically superhydrophobic surfaces.

Synthesis and Visible-Light Photocatalytic Property of Bi2WO6Hierarchical Octahedron-Like Structures

Directory of Open Access Journals (Sweden)

Li Yuanyuan

2008-01-01

Full Text Available Abstract A novel octahedron-like hierarchical structure of Bi2WO6has been fabricated by a facile hydrothermal method in high quantity. XRD, SEM, TEM, and HRTEM were used to characterize the product. The results indicated that this kind of Bi2WO6crystals had an average size of ~4 μm, constructed by quasi-square single-crystal nanosheets assembled in a special fashion. The formation of octahedron-like hierarchical structure of Bi2WO6depended crucially on the pH value of the precursor suspensions. The photocatalytic activity of the hierarchical Bi2WO6structures toward RhB degradation under visible light was investigated, and it was found to be significantly better than that of the sample fabricated by SSR. The better photocatalytic property should be strongly associated with the high specific surface area and the abundant pore structure of the hierarchical octahedron-like Bi2WO6.

Hierarchical structure of correlation functions for single jets

International Nuclear Information System (INIS)

Lupia, S.; Giovannini, A.; Ugoccioni, R.

1993-01-01

Theoretical basis of void scaling function properties of hierarchical structure in rapidity and p T intervals are explored. Their phenomenological consequences are analyzed at single jet level by using Monte Carlo methods in e + e - annihilation. It is found that void scaling function study provides an interesting alternative approach for characterizing single jets of different origin. (orig.)

Enhanced water desalination performance through hierarchically-structured ceramic membranes

NARCIS (Netherlands)

Liu, Tong; Lei, Libin; Gu, Jianqiang; Wang, Yao; Winnubst, Louis; Chen, Chusheng; Ye, Chunsong; Chen, Fanglin

2017-01-01

Developments of membrane water desalination are impeded by low water vapor flux across the membrane. We present an innovative membrane design to significantly enhance the water vapor flux. A bilayer zirconia-based membrane with a thick hierarchically-structured support and a thin functional layer is

Applications of hierarchically structured porous materials from energy storage and conversion, catalysis, photocatalysis, adsorption, separation, and sensing to biomedicine.

Science.gov (United States)

Sun, Ming-Hui; Huang, Shao-Zhuan; Chen, Li-Hua; Li, Yu; Yang, Xiao-Yu; Yuan, Zhong-Yong; Su, Bao-Lian

2016-06-13

Over the last decade, significant effort has been devoted to the applications of hierarchically structured porous materials owing to their outstanding properties such as high surface area, excellent accessibility to active sites, and enhanced mass transport and diffusion. The hierarchy of porosity, structural, morphological and component levels in these materials is key for their high performance in all kinds of applications. The introduction of hierarchical porosity into materials has led to a significant improvement in the performance of materials. Herein, recent progress in the applications of hierarchically structured porous materials from energy conversion and storage, catalysis, photocatalysis, adsorption, separation, and sensing to biomedicine is reviewed. Their potential future applications are also highlighted. We particularly dwell on the relationship between hierarchically porous structures and properties, with examples of each type of hierarchically structured porous material according to its chemical composition and physical characteristics. The present review aims to open up a new avenue to guide the readers to quickly obtain in-depth knowledge of applications of hierarchically porous materials and to have a good idea about selecting and designing suitable hierarchically porous materials for a specific application. In addition to focusing on the applications of hierarchically porous materials, this comprehensive review could stimulate researchers to synthesize new advanced hierarchically porous solids.

Micro-nano hierarchically structured nylon 6,6 surfaces with unique wettability.

Science.gov (United States)

Zhang, Liang; Zhang, Xiaoyan; Dai, Zhen; Wu, Junjie; Zhao, Ning; Xu, Jian

2010-05-01

A micro-nano hierarchically structured nylon 6,6 surface was easily fabricated by phase separation. Nylon 6,6 plate was swelled by formic acid and then immersed in a coagulate bath to precipitate. Micro particles with nano protrusions were generated and linked together covering over the surface. After dried up, the as-formed surface showed superhydrophilic ability. Inspired by lotus only employing 2-tier structure and ordinary plant wax to maintain superhydrophobicity, paraffin wax, a low surface energy material, was used to modify the hierarchically structured nylon 6,6 surface. The resultant surface had water contact angle (CA) of 155.2+/-1.3 degrees and a low sliding angle. The whole process was carried on under ambient condition and only need a few minutes. Copyright 2010 Elsevier Inc. All rights reserved.

Web Application for Hierarchical Organizational Structure Optimization – Human Resource Management Case Study

Directory of Open Access Journals (Sweden)

Kofjač Davorin

2015-08-01

Full Text Available Background and Purpose: In a complex strictly hierarchical organizational structure, undesired oscillations may occur, which have not yet been adequately addressed. Therefore, parameter values, which define fluctuations and transitions from one state to another, need to be optimized to prevent oscillations and to keep parameter values between lower and upper bounds. The objective was to develop a simulation model of hierarchical organizational structure as a web application to help in solving the aforementioned problem.

Hierarchical assembly strategy and multiscale structural origin of exceptional mechanical performance in nacre

Science.gov (United States)

Huang, Zaiwang

Nacre (mother of pearl) is a self-assembled hierarchical nanocomposite in possession of exquisite multiscale architecture and exceptional mechanical properties. Previous work has shown that the highly-ordered brick-mortar-like structure in nacre is assembled via epitaxial growth and the aragonite platelets are pure single-crystals. Our results challenge this conclusion and propose that nacre's individual aragonite platelets are constructed with highly-aligned aragonite nanoparticles mediated by screw dislocation and amorphous aggregation. The underlying physics mechanism why the aragonite nanoparticles choose highly-oriented attachment as its crystallization pathway is rationalized in terms of thermodynamics. The aragonite nanoparticle order-disorder transformation can be triggered by high temperature and mechanical deformation, which in turn confirms that the aragonite nanoparticles are basic building blocks for aragonite platelets. Particularly fascinating is the fracture toughness enhancement of nacre through exquisitely collecting mechanically inferior calcium carbonate (CaCO3) and biomolecules. The sandwich-like microarchitecture with a geometrically staggered arrangement can induce crack deflection along its biopolymer interface, thus significantly enhancing nacre's fracture toughness. Our new findings ambiguously demonstrate that, aside from crack deflection, the advancing crack can invade aragonite platelet, leaving a zigzag crack propagation pathway. These unexpected experimental observations disclose, for the first time, the inevitable structural role of aragonite platelets in enhancing nacre's fracture toughness. Simultaneously, the findings that the crack propagates in a zigzag manner within individual aragonite platelets overturn the previously well-established wisdom that considers aragonite platelets as brittle single-crystals. Moreover, we investigated the dynamical mechanical response of nacre under unixial compression. Our results show that the

Hierarchical sets: analyzing pangenome structure through scalable set visualizations

Science.gov (United States)

2017-01-01

Abstract Motivation: The increase in available microbial genome sequences has resulted in an increase in the size of the pangenomes being analyzed. Current pangenome visualizations are not intended for the pangenome sizes possible today and new approaches are necessary in order to convert the increase in available information to increase in knowledge. As the pangenome data structure is essentially a collection of sets we explore the potential for scalable set visualization as a tool for pangenome analysis. Results: We present a new hierarchical clustering algorithm based on set arithmetics that optimizes the intersection sizes along the branches. The intersection and union sizes along the hierarchy are visualized using a composite dendrogram and icicle plot, which, in pangenome context, shows the evolution of pangenome and core size along the evolutionary hierarchy. Outlying elements, i.e. elements whose presence pattern do not correspond with the hierarchy, can be visualized using hierarchical edge bundles. When applied to pangenome data this plot shows putative horizontal gene transfers between the genomes and can highlight relationships between genomes that is not represented by the hierarchy. We illustrate the utility of hierarchical sets by applying it to a pangenome based on 113 Escherichia and Shigella genomes and find it provides a powerful addition to pangenome analysis. Availability and Implementation: The described clustering algorithm and visualizations are implemented in the hierarchicalSets R package available from CRAN (https://cran.r-project.org/web/packages/hierarchicalSets) Contact: thomasp85@gmail.com Supplementary information: Supplementary data are available at Bioinformatics online. PMID:28130242

From hierarchies to levels : new solutions for games with hierarchical structure

NARCIS (Netherlands)

Álvarez-Mozos, M.; van den Brink, R.; van der Laan, G.; Tejada, O.

2017-01-01

Recently, applications of cooperative game theory to economic allocation problems have gained popularity. In many of these problems, players are organized according to either a hierarchical structure or a levels structure that restrict the players’ possibilities to cooperate. In this paper, we

Biomedical application of hierarchically built structures based on metal oxides

Science.gov (United States)

Korovin, M. S.; Fomenko, A. N.

2017-12-01

Nowadays, the use of hierarchically built structures in biology and medicine arouses much interest. The aim of this work is to review and summarize the available literature data about hierarchically organized structures in biomedical application. Nanoparticles can serve as an example of such structures. Medicine holds a special place among various application methods of similar systems. Special attention is paid to inorganic nanoparticles based on different metal oxides and hydroxides, such as iron, zinc, copper, and aluminum. Our investigations show that low-dimensional nanostructures based on aluminum oxides and hydroxides have an inhibitory effect on tumor cells and possess an antimicrobial activity. At the same time, it is obvious that the large-scale use of nanoparticles by humans needs to thoroughly study their properties. Special attention should be paid to the study of nanoparticle interaction with living biological objects. The numerous data show that there is no clear understanding of interaction mechanisms between nanoparticles and various cell types.

Hierarchical structure of correlation functions for single jets

Energy Technology Data Exchange (ETDEWEB)

Lupia, S. (Dipt. di Fisica Teorica, Univ. di Torino, and INFN, Sezione di Torino (Italy)); Giovannini, A. (Dipt. di Fisica Teorica, Univ. di Torino, and INFN, Sezione di Torino (Italy)); Ugoccioni, R. (Dipt. di Fisica Teorica, Univ. di Torino, and INFN, Sezione di Torino (Italy))

1993-08-01

Theoretical basis of void scaling function properties of hierarchical structure in rapidity and p[sub T] intervals are explored. Their phenomenological consequences are analyzed at single jet level by using Monte Carlo methods in e[sup +]e[sup -] annihilation. It is found that void scaling function study provides an interesting alternative approach for characterizing single jets of different origin. (orig.)

The construction of hierarchical structure on Ti substrate with superior osteogenic activity and intrinsic antibacterial capability

Science.gov (United States)

Huang, Ying; Zha, Guangyu; Luo, Qiaojie; Zhang, Jianxiang; Zhang, Feng; Li, Xiaohui; Zhao, Shifang; Zhu, Weipu; Li, Xiaodong

2014-01-01

The deficient osseointegration and implant-associated infections are pivotal issues for the long-term clinical success of endosteal Ti implants, while development of functional surfaces that can simultaneously overcome these problems remains highly challenging. This study aimed to fabricate sophisticated Ti implant surface with both osteogenic inducing activity and inherent antibacterial ability simply via tailoring surface topographical features. Micro/submciro/nano-scale structure was constructed on Ti by three cumulative subtractive methods, including sequentially conducted sandblasting as well as primary and secondary acid etching treatment. Topographical features of this hierarchical structure can be well tuned by the time of the secondary acid treatment. Ti substrate with mere micro/submicro-scale structure (MS0-Ti) served as a control to examine the influence of hierarchical structures on surface properties and biological activities. Surface analysis indicated that all hierarchically structured surfaces possessed exactly the same surface chemistry as that of MS0-Ti, and all of them showed super-amphiphilicity, high surface free energy, and high protein adsorption capability. Biological evaluations revealed surprisingly antibacterial ability and excellent osteogenic activity for samples with optimized hierarchical structure (MS30-Ti) when compared with MS0-Ti. Consequently, for the first time, a hierarchically structured Ti surface with topography-induced inherent antibacterial capability and excellent osteogenic activity was constructed. PMID:25146099

Intensity-based hierarchical clustering in CT-scans: application to interactive segmentation in cardiology

Science.gov (United States)

Hadida, Jonathan; Desrosiers, Christian; Duong, Luc

2011-03-01

The segmentation of anatomical structures in Computed Tomography Angiography (CTA) is a pre-operative task useful in image guided surgery. Even though very robust and precise methods have been developed to help achieving a reliable segmentation (level sets, active contours, etc), it remains very time consuming both in terms of manual interactions and in terms of computation time. The goal of this study is to present a fast method to find coarse anatomical structures in CTA with few parameters, based on hierarchical clustering. The algorithm is organized as follows: first, a fast non-parametric histogram clustering method is proposed to compute a piecewise constant mask. A second step then indexes all the space-connected regions in the piecewise constant mask. Finally, a hierarchical clustering is achieved to build a graph representing the connections between the various regions in the piecewise constant mask. This step builds up a structural knowledge about the image. Several interactive features for segmentation are presented, for instance association or disassociation of anatomical structures. A comparison with the Mean-Shift algorithm is presented.

On Hierarchical Extensions of Large-Scale 4-regular Grid Network Structures

DEFF Research Database (Denmark)

Pedersen, Jens Myrup; Patel, A.; Knudsen, Thomas Phillip

It is studied how the introduction of ordered hierarchies in 4-regular grid network structures decreses distances remarkably, while at the same time allowing for simple topological routing schemes. Both meshes and tori are considered; in both cases non-hierarchical structures have power law depen...

3D NEAREST NEIGHBOUR SEARCH USING A CLUSTERED HIERARCHICAL TREE STRUCTURE

Directory of Open Access Journals (Sweden)

A. Suhaibah

2016-06-01

Full Text Available Locating and analysing the location of new stores or outlets is one of the common issues facing retailers and franchisers. This is due to assure that new opening stores are at their strategic location to attract the highest possible number of customers. Spatial information is used to manage, maintain and analyse these store locations. However, since the business of franchising and chain stores in urban areas runs within high rise multi-level buildings, a three-dimensional (3D method is prominently required in order to locate and identify the surrounding information such as at which level of the franchise unit will be located or is the franchise unit located is at the best level for visibility purposes. One of the common used analyses used for retrieving the surrounding information is Nearest Neighbour (NN analysis. It uses a point location and identifies the surrounding neighbours. However, with the immense number of urban datasets, the retrieval and analysis of nearest neighbour information and their efficiency will become more complex and crucial. In this paper, we present a technique to retrieve nearest neighbour information in 3D space using a clustered hierarchical tree structure. Based on our findings, the proposed approach substantially showed an improvement of response time analysis compared to existing approaches of spatial access methods in databases. The query performance was tested using a dataset consisting of 500,000 point locations building and franchising unit. The results are presented in this paper. Another advantage of this structure is that it also offers a minimal overlap and coverage among nodes which can reduce repetitive data entry.

The Structure of Affine Buildings

CERN Document Server

Weiss, Richard M

2009-01-01

In The Structure of Affine Buildings, Richard Weiss gives a detailed presentation of the complete proof of the classification of Bruhat-Tits buildings first completed by Jacques Tits in 1986. The book includes numerous results about automorphisms, completions, and residues of these buildings. It also includes tables correlating the results in the locally finite case with the results of Tits's classification of absolutely simple algebraic groups defined over a local field. A companion to Weiss's The Structure of Spherical Buildings, The Structure of Affine Buildings is organized around the clas

Colloidal quantum dot solar cells exploiting hierarchical structuring

KAUST Repository

Labelle, André J.

2015-02-11

Extremely thin-absorber solar cells offer low materials utilization and simplified manufacture but require improved means to enhance photon absorption in the active layer. Here, we report enhanced-absorption colloidal quantum dot (CQD) solar cells that feature transfer-stamped solution-processed pyramid-shaped electrodes employed in a hierarchically structured device. The pyramids increase, by up to a factor of 2, the external quantum efficiency of the device at absorption-limited wavelengths near the absorber band edge. We show that absorption enhancement can be optimized with increased pyramid angle with an appreciable net improvement in power conversion efficiency, that is, with the gain in current associated with improved absorption and extraction overcoming the smaller fractional decrease in open-circuit voltage associated with increased junction area. We show that the hierarchical combination of micron-scale structured electrodes with nanoscale films provides for an optimized enhancement at absorption-limited wavelengths. We fabricate 54.7° pyramid-patterned electrodes, conformally apply the quantum dot films, and report pyramid CQD solar cells that exhibit a 24% improvement in overall short-circuit current density with champion devices providing a power conversion efficiency of 9.2%.

Hierarchical structures in cold-drawn pearlitic steel wire

DEFF Research Database (Denmark)

Zhang, Xiaodan; Godfrey, Andrew; Hansen, Niels

2013-01-01

The microstructure and crystallography of drawn pearlitic steel wires have been quantified by a number of electron microscopy techniques including scanning electron microscopy, transmission electron microscopy, electron backscatter diffraction and nanobeam diffraction, with focus on the change...... in the structure and crystallography when a randomly oriented cementite structure in a patented wire during wire drawing is transformed into a lamellar structure parallel to the drawing axis. Changes in the interlamellar spacing and in the misorientation angle along and across the ferrite lamellae show significant...... through-diameter variations in wires drawn to large strains P 1.5. The structural evolution is hierarchical as the structural variations have their cause in a different macroscopic orientation of the cementite in the initial (patented) structure with respect to the wire axis. The through...

Hierarchical structures in cold-drawn pearlitic steel wire

DEFF Research Database (Denmark)

Zhang, Xiaodan; Godfrey, Andrew; Hansen, Niels

2013-01-01

The microstructure and crystallography of drawn pearlitic steel wires have been quantified by a number of electron microscopy techniques including scanning electron microscopy, transmission electron microscopy, electron backscatter diffraction and nanobeam diffraction, with focus on the change...... in the structure and crystallography when a randomly oriented cementite structure in a patented wire during wire drawing is transformed into a lamellar structure parallel to the drawing axis. Changes in the interlamellar spacing and in the misorientation angle along and across the ferrite lamellae show significant...... through-diameter variations in wires drawn to large strains ⩾ 1.5. The structural evolution is hierarchical as the structural variations have their cause in a different macroscopic orientation of the cementite in the initial (patented) structure with respect to the wire axis. The through...

Topology of the correlation networks among major currencies using hierarchical structure methods

Science.gov (United States)

Keskin, Mustafa; Deviren, Bayram; Kocakaplan, Yusuf

2011-02-01

We studied the topology of correlation networks among 34 major currencies using the concept of a minimal spanning tree and hierarchical tree for the full years of 2007-2008 when major economic turbulence occurred. We used the USD (US Dollar) and the TL (Turkish Lira) as numeraires in which the USD was the major currency and the TL was the minor currency. We derived a hierarchical organization and constructed minimal spanning trees (MSTs) and hierarchical trees (HTs) for the full years of 2007, 2008 and for the 2007-2008 period. We performed a technique to associate a value of reliability to the links of MSTs and HTs by using bootstrap replicas of data. We also used the average linkage cluster analysis for obtaining the hierarchical trees in the case of the TL as the numeraire. These trees are useful tools for understanding and detecting the global structure, taxonomy and hierarchy in financial data. We illustrated how the minimal spanning trees and their related hierarchical trees developed over a period of time. From these trees we identified different clusters of currencies according to their proximity and economic ties. The clustered structure of the currencies and the key currency in each cluster were obtained and we found that the clusters matched nicely with the geographical regions of corresponding countries in the world such as Asia or Europe. As expected the key currencies were generally those showing major economic activity.

Hierarchical periodic micro/nano-structures on nitinol and their influence on oriented endothelialization and anti-thrombosis

International Nuclear Information System (INIS)

Nozaki, Kosuke; Shinonaga, Togo; Ebe, Noriko; Horiuchi, Naohiro; Nakamura, Miho; Tsutsumi, Yusuke; Hanawa, Takao; Tsukamoto, Masahiro; Yamashita, Kimihiro; Nagai, Akiko

2015-01-01

The applications of hierarchical micro/nano-structures, which possess properties of two-scale roughness, have been studied in various fields. In this study, hierarchical periodic micro/nano-structures were fabricated on nitinol, an equiatomic Ni–Ti alloy, using a femtosecond laser for the surface modification of intravascular stents. By controlling the laser fluence, two types of surfaces were developed: periodic nano- and micro/nano-structures. Evaluation of water contact angles indicated that the nano-surface was hydrophilic and the micro/nano-surface was hydrophobic. Endothelial cells aligned along the nano-structures on both surfaces, whereas platelets failed to adhere to the micro/nano-surface. Decorrelation between the responses of the two cell types and the results of water contact angle analysis were a result of the pinning effect. This is the first study to show the applicability of hierarchical periodic micro/nano-structures for surface modification of nitinol. - Highlights: • Hierarchical micro/nano-structures were created on nitinol using a femtosecond laser. • The nano-surface was hydrophilic and the micro/nano-surface was hydrophobic. • Endothelial cells aligned along the nano-structures • Platelets failed to adhere to the micro/nano-surface

Hierarchical periodic micro/nano-structures on nitinol and their influence on oriented endothelialization and anti-thrombosis

Energy Technology Data Exchange (ETDEWEB)

Nozaki, Kosuke [Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, 2-3-10 Kanda-Surugadai, Chiyoda, Tokyo 101-0062 (Japan); Shinonaga, Togo [Joining and Welding Research Institute, Osaka University, 11-1 Mihogaoka, Ibaraki, Osaka 567-0047 (Japan); Ebe, Noriko; Horiuchi, Naohiro; Nakamura, Miho; Tsutsumi, Yusuke; Hanawa, Takao [Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, 2-3-10 Kanda-Surugadai, Chiyoda, Tokyo 101-0062 (Japan); Tsukamoto, Masahiro [Joining and Welding Research Institute, Osaka University, 11-1 Mihogaoka, Ibaraki, Osaka 567-0047 (Japan); Yamashita, Kimihiro [Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, 2-3-10 Kanda-Surugadai, Chiyoda, Tokyo 101-0062 (Japan); Nagai, Akiko, E-mail: nag-bcr@tmd.ac.jp [Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, 2-3-10 Kanda-Surugadai, Chiyoda, Tokyo 101-0062 (Japan)

2015-12-01

The applications of hierarchical micro/nano-structures, which possess properties of two-scale roughness, have been studied in various fields. In this study, hierarchical periodic micro/nano-structures were fabricated on nitinol, an equiatomic Ni–Ti alloy, using a femtosecond laser for the surface modification of intravascular stents. By controlling the laser fluence, two types of surfaces were developed: periodic nano- and micro/nano-structures. Evaluation of water contact angles indicated that the nano-surface was hydrophilic and the micro/nano-surface was hydrophobic. Endothelial cells aligned along the nano-structures on both surfaces, whereas platelets failed to adhere to the micro/nano-surface. Decorrelation between the responses of the two cell types and the results of water contact angle analysis were a result of the pinning effect. This is the first study to show the applicability of hierarchical periodic micro/nano-structures for surface modification of nitinol. - Highlights: • Hierarchical micro/nano-structures were created on nitinol using a femtosecond laser. • The nano-surface was hydrophilic and the micro/nano-surface was hydrophobic. • Endothelial cells aligned along the nano-structures • Platelets failed to adhere to the micro/nano-surface.

Hierarchical ordering with partial pairwise hierarchical relationships on the macaque brain data sets.

Directory of Open Access Journals (Sweden)

Woosang Lim

Full Text Available Hierarchical organizations of information processing in the brain networks have been known to exist and widely studied. To find proper hierarchical structures in the macaque brain, the traditional methods need the entire pairwise hierarchical relationships between cortical areas. In this paper, we present a new method that discovers hierarchical structures of macaque brain networks by using partial information of pairwise hierarchical relationships. Our method uses a graph-based manifold learning to exploit inherent relationship, and computes pseudo distances of hierarchical levels for every pair of cortical areas. Then, we compute hierarchy levels of all cortical areas by minimizing the sum of squared hierarchical distance errors with the hierarchical information of few cortical areas. We evaluate our method on the macaque brain data sets whose true hierarchical levels are known as the FV91 model. The experimental results show that hierarchy levels computed by our method are similar to the FV91 model, and its errors are much smaller than the errors of hierarchical clustering approaches.

Development of ultralight, super-elastic, hierarchical metallic meta-structures with i3DP technology

Science.gov (United States)

Zhang, Dongxing; Xiao, Junfeng; Moorlag, Carolyn; Guo, Qiuquan; Yang, Jun

2017-11-01

Lightweight and mechanically robust materials show promising applications in thermal insulation, energy absorption, and battery catalyst supports. This study demonstrates an effective method for creation of ultralight metallic structures based on initiator-integrated 3D printing technology (i3DP), which provides a possible platform to design the materials with the best geometric parameters and desired mechanical performance. In this study, ultralight Ni foams with 3D interconnected hollow tubes were fabricated, consisting of hierarchical features spanning three scale orders ranging from submicron to centimeter. The resultant materials can achieve an ultralight density of as low as 5.1 mg cm-3 and nearly recover after significant compression up to 50%. Due to a high compression ratio, the hierarchical structure exhibits superior properties in terms of energy absorption and mechanical efficiency. The relationship of structural parameters and mechanical response was established. The ability of achieving ultralight density printing approach provides metallic structures with substantial benefits from the hierarchical design and fabrication flexibility to ultralight applications.

A hierarchical structure through imprinting of a polyimide precursor without residual layers

International Nuclear Information System (INIS)

Pai, I-Ting; Hon, Min-Hsiung; Leu, Ing-Chi

2008-01-01

A patterned polyimide without a residual layer is obtained by imprinting with the assistance of a residual solvent. The effects of the wetting behaviors of the poly-amic acid (PAA) solution coated on various surfaces are examined and the formation of hierarchical patterns without residual layers is demonstrated. polydimethylsiloxane (PDMS) and PEI/PDMS are used as imprinting molds with Si and 300 nm SiO 2 /Si as substrates. The results indicate that the various ambits of patterns without a residual layer are formed due to the dewetting phenomena caused by surface tension (Suh 2006 Small 2 832). During imprinting, PDMS with a low surface energy makes the PAA solution flow away from its surface exposing the contact area due to dewetting. Self-organized hierarchical structures are also obtained from this process due to effective dewetting. The present study provides a new approach for fabricating patterns without residual layers and the consequent preparation of hierarchical structures, which is considered to be impossible using the lithographic technique

Content Consumption and Hierarchical Structures of Web-Supported Courses

Science.gov (United States)

Hershkovitz, Arnon; Hardof-Jaffe, Sharon; Nachmias, Rafi

2014-01-01

This study presents an empirical investigation of the relationship between the hierarchical structure of content delivered to students within a Learning Management System (LMS) and its actual consumption. To this end, campus-wide data relating to 1,203 courses were collected from the LMS' servers and were subsequently analyzed using data mining…

Inferring hierarchical clustering structures by deterministic annealing

International Nuclear Information System (INIS)

Hofmann, T.; Buhmann, J.M.

1996-01-01

The unsupervised detection of hierarchical structures is a major topic in unsupervised learning and one of the key questions in data analysis and representation. We propose a novel algorithm for the problem of learning decision trees for data clustering and related problems. In contrast to many other methods based on successive tree growing and pruning, we propose an objective function for tree evaluation and we derive a non-greedy technique for tree growing. Applying the principles of maximum entropy and minimum cross entropy, a deterministic annealing algorithm is derived in a meanfield approximation. This technique allows us to canonically superimpose tree structures and to fit parameters to averaged or open-quote fuzzified close-quote trees

Dynamic control of quadruped robot with hierarchical control structure

International Nuclear Information System (INIS)

Wang, Yu-Zhang; Furusho, Junji; Okajima, Yosuke.

1988-01-01

For moving on irregular terrain, such as the inside of a nuclear power plant and outer space, it is generally recognized that the multilegged walking robot is suitable. This paper proposes a hierarchical control structure for the dynamic control of quadruped walking robots. For this purpose, we present a reduced order model which can approximate the original higher order model very well. Since this reduced order model does not require much computational time, it can be used in the real-time control of a quadruped walking robot. A hierarchical control experiment is shown in which the optimal control algorithm using a reduced order model is calculated by one microprocessor, and the other control algorithm is calculated by another microprocessor. (author)

Photoelectrochemical properties of the TiO2-ZnO nanorod hierarchical structure prepared by hydrothermal process

Directory of Open Access Journals (Sweden)

Bao SUN

2018-02-01

Full Text Available In order to increase the transport channels of the photogenerated electrons and enhance the photosensitizer loading ability of the electrode, a new TiO2-ZnO nanorod hierarchical structure is prepared through two-step hydrothermal process. First, TiO2 nanorod array is grown on the FTO conductive glass substrate by hydrothermal proess. Then, ZnO sol is coated onto the TiO2 nanorods through dip-coating method and inverted to ZnO seed layer by sintering. Finally, the secondary ZnO nanorods are grown onto the TiO2 nanorods by the sencond hydrothermal method to form the designed TiO2-ZnO nanorod hierarchical structure. A spin-coating assisted successive ionic layer reaction method (SC-SILR is used to deposit the CdS nanocrystals into the TiO2 nanorod array and the TiO2-ZnO nanorod hierarchical structure is used to form the CdS/TiO2 and CdS/TiO2-ZnO nanocomposite films. Different methods, such as SEM, TEM, XRD, UV-Vis and transient photocurrent, are employed to characterize and measure the morphologies, structures, light absorption and photoelectric conversion performance of all the samples, respectively. The results indicate that, compared with the pure TiO2 nanorod array, the TiO2-ZnO nanorod hierarchical structure can load more CdS photosensitizer. The light absorption properties and transient photocurrent performance of the CdS/TiO2-ZnO nanorod hierarchical structure composite film are evidently superior to that of the CdS/TiO2 nanocomposite films. The excellent photoelctrochemical performance of theTiO2-ZnO hierarchical structure reveales its application prospect in photoanode material of the solar cells.

How hierarchical is language use?

Science.gov (United States)

Frank, Stefan L.; Bod, Rens; Christiansen, Morten H.

2012-01-01

It is generally assumed that hierarchical phrase structure plays a central role in human language. However, considerations of simplicity and evolutionary continuity suggest that hierarchical structure should not be invoked too hastily. Indeed, recent neurophysiological, behavioural and computational studies show that sequential sentence structure has considerable explanatory power and that hierarchical processing is often not involved. In this paper, we review evidence from the recent literature supporting the hypothesis that sequential structure may be fundamental to the comprehension, production and acquisition of human language. Moreover, we provide a preliminary sketch outlining a non-hierarchical model of language use and discuss its implications and testable predictions. If linguistic phenomena can be explained by sequential rather than hierarchical structure, this will have considerable impact in a wide range of fields, such as linguistics, ethology, cognitive neuroscience, psychology and computer science. PMID:22977157

Near-Infrared Trigged Stimulus-Responsive Photonic Crystals with Hierarchical Structures.

Science.gov (United States)

Lu, Tao; Pan, Hui; Ma, Jun; Li, Yao; Zhu, Shenmin; Zhang, Di

2017-10-04

Stimuli-responsive photonic crystals (PCs) trigged by light would provide a novel intuitive and quantitative method for noninvasive detection. Inspired by the flame-detecting aptitude of fire beetles and the hierarchical photonic structures of butterfly wings, we herein developed near-infrared stimuli-responsive PCs through coupling photothermal Fe 3 O 4 nanoparticles with thermoresponsive poly(N-isopropylacrylamide) (PNIPAM), with hierarchical photonic structured butterfly wing scales as the template. The nanoparticles within 10 s transferred near-infrared radiation into heat that triggered the phase transition of PNIPAM; this almost immediately posed an anticipated effect on the PNIPAM refractive index and resulted in a composite spectrum change of ∼26 nm, leading to the direct visual readout. It is noteworthy that the whole process is durable and stable mainly owing to the chemical bonding formed between PNIPAM and the biotemplate. We envision that this biologically inspired approach could be utilized in a broad range of applications and would have a great impact on various monitoring processes and medical sensing.

Self-assembly of nano/micro-structured Fe3O4 microspheres among 3D rGO/CNTs hierarchical networks with superior lithium storage performances

International Nuclear Information System (INIS)

Liu, Jinlong; Feng, Haibo; Wang, Xipeng; Qian, Dong; Jiang, Jianbo; Li, Junhua; Peng, Sanjun; Deng, Miao; Liu, Youcai

2014-01-01

Nano/micro-structured Fe 3 O 4 microspheres among three-dimensional (3D) reduced graphene oxide (rGO)/carbon nanotubes (CNTs) hierarchical networks (the ternary composite is denoted as rGCFs) have been synthesized using a facile, self-assembled and one-pot hydrothermal approach. The rGCFs composite exhibits superior lithium storage performances: initial discharge and charge capacities of 1452 and 1036 mAh g −1 , respectively, remarkable rate capability at current densities from 100 mA g −1 to 10 A g −1 and outstanding cycling performance up to 200 cycles. The highly enhanced electrochemical performances of rGCFs depend heavily on the robust 3D rGO/CNTs hierarchical networks, the stable nano/microstructures of active Fe 3 O 4 microspheres and the positive synergistic effects of building components. The systematic structure characterizations and electrochemical investigations provide insightful understanding towards the relationship between structure/morphology and lithium storage performances, which may pave the way for the rational design of composite materials with desirable goals. (papers)

Synthesis and properties of ZnFe2O4 replica with biological hierarchical structure

International Nuclear Information System (INIS)

Liu, Hongyan; Guo, Yiping; Zhang, Yangyang; Wu, Fen; Liu, Yun; Zhang, Di

2013-01-01

Highlights: • ZFO replica with hierarchical structure was synthesized from butterfly wings. • Biotemplate has a significant impact on the properties of ZFO material. • Our method opens up new avenues for the synthesis of spinel ferrites. -- Abstract: ZnFe 2 O 4 replica with biological hierarchical structure was synthesized from Papilio paris by a sol–gel method followed by calcination. The crystallographic structure and morphology of the obtained samples were characterized by X-ray diffraction, field-emission scanning electron microscope, and transmittance electron microscope. The results showed that the hierarchical structures were retained in the ZFO replica of spinel structure. The magnetic behavior of such novel products was measured by a vibrating sample magnetometer. A superparamagnetism-like behavior was observed due to nanostructuration size effects. In addition, the ZFO replica with “quasi-honeycomb-like structure” showed a much higher specific capacitance of 279.4 F g −1 at 10 mV s −1 in comparison with ZFO powder of 137.3 F g −1 , attributing to the significantly increased surface area. These results demonstrated that ZFO replica is a promising candidate for novel magnetic devices and supercapacitors

A Dynamic Construction Algorithm for the Compact Patricia Trie Using the Hierarchical Structure.

Science.gov (United States)

Jung, Minsoo; Shishibori, Masami; Tanaka, Yasuhiro; Aoe, Jun-ichi

2002-01-01

Discussion of information retrieval focuses on the use of binary trees and how to compact it to use less memory and take less time. Explains retrieval algorithms and describes data structure and hierarchical structure. (LRW)

Three-dimensional hierarchical structures for fog harvesting.

Science.gov (United States)

Andrews, H G; Eccles, E A; Schofield, W C E; Badyal, J P S

2011-04-05

Conventional fog-harvesting mechanisms are effectively pseudo-2D surface phenomena in terms of water droplet-plant interactions. In the case of the Cotula fallax plant, a unique hierarchical 3D arrangement formed by its leaves and the fine hairs covering them has been found to underpin the collection and retention of water droplets on the foliage for extended periods of time. The mechanisms of water capture and release as a function of the surface 3D structure and chemistry have been identified. Of particular note is that water is retained throughout the entirety of the plant and held within the foliage itself (rather than in localized regions). Individual plant hairs form matlike structures capable of supporting water droplets; these hairs wrap around water droplets in a 3D fashion to secure them via a fine nanoscale groove structure that prevents them from easily falling to the ground.

Au functionalized ZnO rose-like hierarchical structures and their enhanced NO2 sensing performance

Science.gov (United States)

Shingange, K.; Swart, H. C.; Mhlongo, G. H.

2018-04-01

Herein, we present ZnO rose-like hierarchical nanostructures employed as support to Au nanoparticles to produce Au functionalized three dimensional (3D) ZnO hierarchical nanostructures (Au/ZnO) for NO2 detection using a microwave-assisted method. Comparative analysis of NO2 sensing performance between the pristine ZnO and Au/ZnO rose-like structures at 300 °C revealed improved NO2 response and rapid response-recovery times with Au incorporation owing to a combination of high surface accessibility induced by hierarchical nanostructure design and catalytic activity of the small Au nanoparticles. Structural and optical analyses acquired from X-ray diffraction, scanning electron microscopy, transmission electron microscope and photoluminescence spectroscopy were also performed.

Liquid phase epitaxial growth of heterostructured hierarchical MOF thin films

KAUST Repository

Chernikova, Valeriya

2017-05-10

Precise control of epitaxial growth of MOF-on-MOF thin films, for ordered hierarchical tbo-type structures is demonstrated. The heterostructured MOF thin film was fabricated by successful sequential deposition of layers from two different MOFs. The 2-periodic layers, edge-transitive 4,4-square lattices regarded as supermolecular building layers, were commendably cross-linked using a combination of inorganic/organic and organic pillars.

Liquid phase epitaxial growth of heterostructured hierarchical MOF thin films

KAUST Repository

Chernikova, Valeriya; Shekhah, Osama; Spanopoulos, Ioannis; Trikalitis, Pantelis N.; Eddaoudi, Mohamed

2017-01-01

Precise control of epitaxial growth of MOF-on-MOF thin films, for ordered hierarchical tbo-type structures is demonstrated. The heterostructured MOF thin film was fabricated by successful sequential deposition of layers from two different MOFs. The 2-periodic layers, edge-transitive 4,4-square lattices regarded as supermolecular building layers, were commendably cross-linked using a combination of inorganic/organic and organic pillars.

Enhanced photocatalytic properties of hierarchical three-dimensional TiO{sub 2} grown on femtosecond laser structured titanium substrate

Energy Technology Data Exchange (ETDEWEB)

Huang, Ting, E-mail: huangting@bjut.edu.cn; Lu, Jinlong; Xiao, Rongshi; Wu, Qiang; Yang, Wuxiong

2017-05-01

Highlights: • The hierarchical 3D-TiO{sub 2} is fabricated on femtosecond laser structured Ti substrate. • The formation mechanism of hierarchical 3D-TiO{sub 2} is proposed. • The structure-induced improvement of photocatalytic activity is reported. - Abstract: Three-dimensional micro-/nanostructured TiO{sub 2} (3D-TiO{sub 2}) fabricated on titanium substrate effectively improves its performance in photocatalysis, dye-sensitized solar cell and lithium-ion battery applications. In this study, the hierarchical 3D-TiO{sub 2} with anatase phase directly grown on femtosecond laser structured titanium substrate is reported. First, the primary columnar arrays were fabricated on the surface of titanium substrate by femtosecond laser structuring. Next, the secondary nano-sheet substructures were grown on the primary columnar arrays by NaOH hydrothermal treatment. Followed by ion-exchange process in HCl and annealing in the air, the hierarchical anatase 3D-TiO{sub 2} was achieved. The hierarchical anatase 3D-TiO{sub 2} exhibited enhanced performances in light harvesting and absorption ability compared to that of nano-sheet TiO{sub 2} grown on flat titanium surface without femtosecond laser structuring. The photocatalytic degradation of methyl orange reveals that photocatalytic efficiency of the hierarchical anatase 3D-TiO{sub 2} was improved by a maximum of 57% compared to that of nano-sheet TiO{sub 2} (55% vs 35%). Meanwhile, the hierarchical anatase 3D-TiO{sub 2} remained mechanically stable and constant in consecutive degradation cycles, which promises significance in practical application.

A Facile Method to Fabricate Anisotropic Hydrogels with Perfectly Aligned Hierarchical Fibrous Structures.

Science.gov (United States)

Mredha, Md Tariful Islam; Guo, Yun Zhou; Nonoyama, Takayuki; Nakajima, Tasuku; Kurokawa, Takayuki; Gong, Jian Ping

2018-03-01

Natural structural materials (such as tendons and ligaments) are comprised of multiscale hierarchical architectures, with dimensions ranging from nano- to macroscale, which are difficult to mimic synthetically. Here a bioinspired, facile method to fabricate anisotropic hydrogels with perfectly aligned multiscale hierarchical fibrous structures similar to those of tendons and ligaments is reported. The method includes drying a diluted physical hydrogel in air by confining its length direction. During this process, sufficiently high tensile stress is built along the length direction to align the polymer chains and multiscale fibrous structures (from nano- to submicro- to microscale) are spontaneously formed in the bulk material, which are well-retained in the reswollen gel. The method is useful for relatively rigid polymers (such as alginate and cellulose), which are susceptible to mechanical signal. By controlling the drying with or without prestretching, the degree of alignment, size of superstructures, and the strength of supramolecular interactions can be tuned, which sensitively influence the strength and toughness of the hydrogels. The mechanical properties are comparable with those of natural ligaments. This study provides a general strategy for designing hydrogels with highly ordered hierarchical structures, which opens routes for the development of many functional biomimetic materials for biomedical applications. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Hierarchically structured photonic crystals for integrated chemical separation and colorimetric detection.

Science.gov (United States)

Fu, Qianqian; Zhu, Biting; Ge, Jianping

2017-02-16

A SiO 2 colloidal photonic crystal film with a hierarchical porous structure is fabricated to demonstrate an integrated separation and colorimetric detection of chemical species for the first time. This new photonic crystal based thin layer chromatography process requires no dyeing, developing and UV irradiation compared to the traditional TLC. The assembling of mesoporous SiO 2 particles via a supersaturation-induced-precipitation process forms uniform and hierarchical photonic crystals with micron-scale cracks and mesopores, which accelerate the diffusion of developers and intensify the adsorption/desorption between the analytes and silica for efficient separation. Meanwhile, the chemical substances infiltrated to the voids of photonic crystals cause an increase of the refractive index and a large contrast of structural colors towards the unloaded part, so that the sample spots can be directly recognized with the naked eye before and after separation.

Hierarchical structure for risk criteria applicable to nuclear power plants

International Nuclear Information System (INIS)

Hall, R.E.; Mitra, S.P.

1985-01-01

This paper discusses the development of a hierarchical structure for risk criteria applicable to nuclear power plants. The structure provides a unified framework to systematically analyze the implications of different types of criteria, each focusing on a particular aspect of nuclear power plant risks. The framework allows investigation of the specific coverage of a particular criterion and comparison of different criteria with regard to areas to which they apply. 5 refs., 2 figs

Superhydrophobic surface based on a coral-like hierarchical structure of ZnO.

Directory of Open Access Journals (Sweden)

Jun Wu

2010-12-01

Full Text Available Fabrication of superhydrophobic surfaces has attracted much interest in the past decade. The fabrication methods that have been studied are chemical vapour deposition, the sol-gel method, etching technique, electrochemical deposition, the layer-by-layer deposition, and so on. Simple and inexpensive methods for manufacturing environmentally stable superhydrophobic surfaces have also been proposed lately. However, work referring to the influence of special structures on the wettability, such as hierarchical ZnO nanostructures, is rare.This study presents a simple and reproducible method to fabricate a superhydrophobic surface with micro-scale roughness based on zinc oxide (ZnO hierarchical structure, which is grown by the hydrothermal method with an alkaline aqueous solution. Coral-like structures of ZnO were fabricated on a glass substrate with a micro-scale roughness, while the antennas of the coral formed the nano-scale roughness. The fresh ZnO films exhibited excellent superhydrophilicity (the apparent contact angle for water droplet was about 0°, while the ability to be wet could be changed to superhydrophobicity after spin-coating Teflon (the apparent contact angle greater than 168°. The procedure reported here can be applied to substrates consisting of other materials and having various shapes.The new process is convenient and environmentally friendly compared to conventional methods. Furthermore, the hierarchical structure generates the extraordinary solid/gas/liquid three-phase contact interface, which is the essential characteristic for a superhydrophobic surface.

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.

UV-assisted capillary force lithography for engineering biomimetic multiscale hierarchical structures: From lotus leaf to gecko foot hairs

KAUST Repository

Jeong, Hoon Eui; Kwak, Rhokyun; Khademhosseini, Ali; Suh, Kahp Y.

2009-01-01

This feature article provides an overview of the recently developed two-step UV-assisted capillary force lithography and its application to fabricating well-defined micro/nanoscale hierarchical structures. This method utilizes an oxygen inhibition effect in the course of UV irradiation curing and a two-step moulding process, to form multiscale hierarchical or suspended nanobridge structures in a rapid and reproducible manner. After a brief description of the fabrication principles, several examples of the two-step UV-assisted moulding technique are presented. In addition, emerging applications of the multiscale hierarchical structures are briefly described. © The Royal Society of Chemistry 2009.

Hierarchical architecture of active knits

International Nuclear Information System (INIS)

Abel, Julianna; Luntz, Jonathan; Brei, Diann

2013-01-01

Nature eloquently utilizes hierarchical structures to form the world around us. Applying the hierarchical architecture paradigm to smart materials can provide a basis for a new genre of actuators which produce complex actuation motions. One promising example of cellular architecture—active knits—provides complex three-dimensional distributed actuation motions with expanded operational performance through a hierarchically organized structure. The hierarchical structure arranges a single fiber of active material, such as shape memory alloys (SMAs), into a cellular network of interlacing adjacent loops according to a knitting grid. This paper defines a four-level hierarchical classification of knit structures: the basic knit loop, knit patterns, grid patterns, and restructured grids. Each level of the hierarchy provides increased architectural complexity, resulting in expanded kinematic actuation motions of active knits. The range of kinematic actuation motions are displayed through experimental examples of different SMA active knits. The results from this paper illustrate and classify the ways in which each level of the hierarchical knit architecture leverages the performance of the base smart material to generate unique actuation motions, providing necessary insight to best exploit this new actuation paradigm. (paper)

Programming Hierarchical Self-Assembly of Patchy Particles into Colloidal Crystals via Colloidal Molecules.

Science.gov (United States)

Morphew, Daniel; Shaw, James; Avins, Christopher; Chakrabarti, Dwaipayan

2018-03-27

Colloidal self-assembly is a promising bottom-up route to a wide variety of three-dimensional structures, from clusters to crystals. Programming hierarchical self-assembly of colloidal building blocks, which can give rise to structures ordered at multiple levels to rival biological complexity, poses a multiscale design problem. Here we explore a generic design principle that exploits a hierarchy of interaction strengths and employ this design principle in computer simulations to demonstrate the hierarchical self-assembly of triblock patchy colloidal particles into two distinct colloidal crystals. We obtain cubic diamond and body-centered cubic crystals via distinct clusters of uniform size and shape, namely, tetrahedra and octahedra, respectively. Such a conceptual design framework has the potential to reliably encode hierarchical self-assembly of colloidal particles into a high level of sophistication. Moreover, the design framework underpins a bottom-up route to cubic diamond colloidal crystals, which have remained elusive despite being much sought after for their attractive photonic applications.

On Structure, Family and Parameter Estimation of Hierarchical Archimedean Copulas

Czech Academy of Sciences Publication Activity Database

Górecki, J.; Hofert, M.; Holeňa, Martin

2017-01-01

Roč. 87, č. 17 (2017), s. 3261-3324 ISSN 0094-9655 R&D Projects: GA ČR GA17-01251S Institutional support: RVO:67985807 Keywords : copula estimation * goodness-of-fit * Hierarchical Archimedean copula * structure determination Subject RIV: IN - Informatics, Computer Science OBOR OECD: Statistics and probability Impact factor: 0.757, year: 2016

Facile synthesis of Zn doped CuO hierarchical nanostructures: Structural, optical and antibacterial properties

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Javed Iqbal

2015-12-01

Full Text Available ZnxCu1−xO (where x= 0, 0.01, 0.03, 0.05, 0.07 and 0.1 mol% hierarchical nanostructures have been prepared via soft chemical route. X-ray diffraction (XRD results of the synthesized samples reveal the monoclinic structure of CuO without any impurity related phases. The micro-structural parameters such as crystallite size and microstrain have been strongly influenced by Zn doping. Scanning electron microscope (SEM analyses depict the formation of hierarchical nanostructures having average particle size in the range of 26-43 nm. The surface area of CuO nanostructures has been reduced systematically with the increase in Zn content which is linked with the variations in particle size. An obvious decrease in the optical band gap energy of the synthesized CuO hierarchical nanostructures has been observed with Zn doping which is assigned to the formation of shallow levels in the band gap of CuO and combined transition from oxygen 2p states to d sates of Cu and Zn ions. The bactericidal potency of the CuO hierarchical nanostructures have been found to be enhanced remarkably with Zn doping.

Facile synthesis of Zn doped CuO hierarchical nanostructures: Structural, optical and antibacterial properties

Energy Technology Data Exchange (ETDEWEB)

Iqbal, Javed, E-mail: tariqjan84@gmail.com, E-mail: javed.suggau@iiu.edu.pk; Jan, Tariq, E-mail: tariqjan84@gmail.com, E-mail: javed.suggau@iiu.edu.pk; Ul-Hassan, Sibt; Umair Ali, M.; Abbas, Fazal [Laboratory of Nanoscience and Technology, Department of Physics, International Islamic University, H-10, Islamabad (Pakistan); Ahmed, Ishaq [Experimental Physics Labs, National Center for Physics, Islamabad (Pakistan); Mansoor, Qaisar; Ismail, Muhammad [Institute of Biomedical and Genetic Engineering (IBGE), Islamabad (Pakistan)

2015-12-15

Zn{sub x}Cu{sub 1−x}O (where x= 0, 0.01, 0.03, 0.05, 0.07 and 0.1 mol%) hierarchical nanostructures have been prepared via soft chemical route. X-ray diffraction (XRD) results of the synthesized samples reveal the monoclinic structure of CuO without any impurity related phases. The micro-structural parameters such as crystallite size and microstrain have been strongly influenced by Zn doping. Scanning electron microscope (SEM) analyses depict the formation of hierarchical nanostructures having average particle size in the range of 26-43 nm. The surface area of CuO nanostructures has been reduced systematically with the increase in Zn content which is linked with the variations in particle size. An obvious decrease in the optical band gap energy of the synthesized CuO hierarchical nanostructures has been observed with Zn doping which is assigned to the formation of shallow levels in the band gap of CuO and combined transition from oxygen 2p states to d sates of Cu and Zn ions. The bactericidal potency of the CuO hierarchical nanostructures have been found to be enhanced remarkably with Zn doping.

Self-cleaning poly(dimethylsiloxane) film with functional micro/nano hierarchical structures.

Science.gov (United States)

Zhang, Xiao-Sheng; Zhu, Fu-Yun; Han, Meng-Di; Sun, Xu-Ming; Peng, Xu-Hua; Zhang, Hai-Xia

2013-08-27

This paper reports a novel single-step wafer-level fabrication of superhydrophobic micro/nano dual-scale (MNDS) poly(dimethylsiloxane) (PDMS) films. The MNDS PDMS films were replicated directly from an ultralow-surface-energy silicon substrate at high temperature without any surfactant coating, achieving high precision. An improved deep reactive ion etching (DRIE) process with enhanced passivation steps was proposed to easily realize the ultralow-surface-energy MNDS silicon substrate and also utilized as a post-treatment process to strengthen the hydrophobicity of the MNDS PDMS film. The chemical modification of this enhanced passivation step to the surface energy has been studied by density functional theory, which is also the first investigation of C4F8 plasma treatment at molecular level by using first-principle calculations. From the results of a systematic study on the effect of key process parameters (i.e., baking temperature and time) on PDMS replication, insight into the interaction of hierarchical multiscale structures of polymeric materials during the micro/nano integrated fabrication process is experimentally obtained for the first time. Finite element simulation has been employed to illustrate this new phenomenon. Additionally, hierarchical PDMS pyramid arrays and V-shaped grooves have been developed and are intended for applications as functional structures for a light-absorption coating layer and directional transport of liquid droplets, respectively. This stable, self-cleaning PDMS film with functional micro/nano hierarchical structures, which is fabricated through a wafer-level single-step fabrication process using a reusable silicon mold, shows attractive potential for future applications in micro/nanodevices, especially in micro/nanofluidics.

Synthesis and Characterization of Hierarchical Structured TiO2 Nanotubes and Their Photocatalytic Performance on Methyl Orange

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Kai Liu

2015-01-01

Full Text Available Hierarchical structured TiO2 nanotubes were prepared by mechanical ball milling of highly ordered TiO2 nanotube arrays grown by electrochemical anodization of titanium foil. Scanning electron microscopy, transmission electron microscopy, X-ray diffraction, specific surface area analysis, UV-visible absorption spectroscopy, photocurrent measurement, photoluminescence spectra, electrochemical impedance spectra, and photocatalytic degradation test were applied to characterize the nanocomposites. Surface area increased as the milling time extended. After 5 h ball milling, TiO2 hierarchical nanotubes exhibited a corn-like shape and exhibited enhanced photoelectrochemical activity in comparison to commercial P25. The superior photocatalytic activity is suggested to be due to the combined advantages of high surface area of nanoparticles and rapid electron transfer as well as collection of the nanotubes in the hierarchical structure. The hierarchical structured TiO2 nanotubes could be applied into flexible applications on solar cells, sensors, and other photoelectrochemical devices.

Genomic analysis of the hierarchical structure of regulatory networks

Science.gov (United States)

Yu, Haiyuan; Gerstein, Mark

2006-01-01

A fundamental question in biology is how the cell uses transcription factors (TFs) to coordinate the expression of thousands of genes in response to various stimuli. The relationships between TFs and their target genes can be modeled in terms of directed regulatory networks. These relationships, in turn, can be readily compared with commonplace “chain-of-command” structures in social networks, which have characteristic hierarchical layouts. Here, we develop algorithms for identifying generalized hierarchies (allowing for various loop structures) and use these approaches to illuminate extensive pyramid-shaped hierarchical structures existing in the regulatory networks of representative prokaryotes (Escherichia coli) and eukaryotes (Saccharomyces cerevisiae), with most TFs at the bottom levels and only a few master TFs on top. These masters are situated near the center of the protein–protein interaction network, a different type of network from the regulatory one, and they receive most of the input for the whole regulatory hierarchy through protein interactions. Moreover, they have maximal influence over other genes, in terms of affecting expression-level changes. Surprisingly, however, TFs at the bottom of the regulatory hierarchy are more essential to the viability of the cell. Finally, one might think master TFs achieve their wide influence through directly regulating many targets, but TFs with most direct targets are in the middle of the hierarchy. We find, in fact, that these midlevel TFs are “control bottlenecks” in the hierarchy, and this great degree of control for “middle managers” has parallels in efficient social structures in various corporate and governmental settings. PMID:17003135

Localizing age-related individual differences in a hierarchical structure

OpenAIRE

Salthouse, Timothy A.

2004-01-01

Data from 33 separate studies were combined to create an aggregate data set consisting of 16 cognitive variables and 6832 different individuals who ranged between 18 and 95 years of age. Analyses were conducted to determine where in a hierarchical structure of cognitive abilities individual differences associated with age, gender, education, and self-reported health could be localized. The results indicated that each type of individual difference characteristic exhibited a d...

Structural and photovoltaic characteristics of hierarchical ZnO nanostructures electrodes

Energy Technology Data Exchange (ETDEWEB)

Saleem, Muhammad, E-mail: saleem.malikape@gmail.com [Department of Physics, COMSATS Institute of Information Technology, Lahore 54000 (Pakistan); Key Laboratory of Optoelectronic Technology and Systems of the Education Ministry of China, Chongqing University, Chongqing 400044 (China); Fang, L. [Key Laboratory of Optoelectronic Technology and Systems of the Education Ministry of China, Chongqing University, Chongqing 400044 (China); Shaukat, Saleem F.; Ahmad, M. Ashfaq [Department of Physics, COMSATS Institute of Information Technology, Lahore 54000 (Pakistan); Raza, Rizwan, E-mail: razahussaini786@gmail.com [Department of Physics, COMSATS Institute of Information Technology, Lahore 54000 (Pakistan); Akhtar, Majid Niaz; Jamil, Ayesha; Aslam, Samia [Department of Physics, COMSATS Institute of Information Technology, Lahore 54000 (Pakistan); Abbas, Ghazanfar [Department of Physics, COMSATS Institute of Information Technology, Islamabad 44000 (Pakistan)

2015-04-15

Highlights: • Hierarchically ZnO nanostructures electrodes were grown using hot plate magnetic stirring at different growth reaction temperature. • We have investigated the effect of working temperature of 160°, 170°, 180°, and 190° on the growth mechanism of nanospheres and on the power conversion efficiency of DSSCs. • ZnO nanospheres with perfect aggregation show superior power conversion efficiency of 1.24% which is about 83% higher than nanoparticles DSSC. • An obvious vogue is that the overall power conversion efficiency decreases as the degree of the spherical aggregation is gradually destroyed. - Abstract: Structural and photovoltaic characteristics of hierarchical ZnO nanostructures solar cell have been studied in relation to growth reaction temperature. It is found that the hierarchical ZnO nanostructures network to act not only as large surface area substrates but also as a transport medium for electrons injected from the dye molecules. The incident photon-to-current conversion efficiency is decreased by increasing the growth reaction temperature of ZnO electrodes. The best conversion efficiency of a 0.25 cm{sup 2} cell is measured to be 1.24% under 100 mW cm{sup −2} irradiation.

Structural and photovoltaic characteristics of hierarchical ZnO nanostructures electrodes

International Nuclear Information System (INIS)

Saleem, Muhammad; Fang, L.; Shaukat, Saleem F.; Ahmad, M. Ashfaq; Raza, Rizwan; Akhtar, Majid Niaz; Jamil, Ayesha; Aslam, Samia; Abbas, Ghazanfar

2015-01-01

Highlights: • Hierarchically ZnO nanostructures electrodes were grown using hot plate magnetic stirring at different growth reaction temperature. • We have investigated the effect of working temperature of 160°, 170°, 180°, and 190° on the growth mechanism of nanospheres and on the power conversion efficiency of DSSCs. • ZnO nanospheres with perfect aggregation show superior power conversion efficiency of 1.24% which is about 83% higher than nanoparticles DSSC. • An obvious vogue is that the overall power conversion efficiency decreases as the degree of the spherical aggregation is gradually destroyed. - Abstract: Structural and photovoltaic characteristics of hierarchical ZnO nanostructures solar cell have been studied in relation to growth reaction temperature. It is found that the hierarchical ZnO nanostructures network to act not only as large surface area substrates but also as a transport medium for electrons injected from the dye molecules. The incident photon-to-current conversion efficiency is decreased by increasing the growth reaction temperature of ZnO electrodes. The best conversion efficiency of a 0.25 cm 2 cell is measured to be 1.24% under 100 mW cm −2 irradiation

Hierarchically organized layout for visualization of biochemical pathways.

Science.gov (United States)

Tsay, Jyh-Jong; Wu, Bo-Liang; Jeng, Yu-Sen

2010-01-01

Many complex pathways are described as hierarchical structures in which a pathway is recursively partitioned into several sub-pathways, and organized hierarchically as a tree. The hierarchical structure provides a natural way to visualize the global structure of a complex pathway. However, none of the previous research on pathway visualization explores the hierarchical structures provided by many complex pathways. In this paper, we aim to develop algorithms that can take advantages of hierarchical structures, and give layouts that explore the global structures as well as local structures of pathways. We present a new hierarchically organized layout algorithm to produce layouts for hierarchically organized pathways. Our algorithm first decomposes a complex pathway into sub-pathway groups along the hierarchical organization, and then partition each sub-pathway group into basic components. It then applies conventional layout algorithms, such as hierarchical layout and force-directed layout, to compute the layout of each basic component. Finally, component layouts are joined to form a final layout of the pathway. Our main contribution is the development of algorithms for decomposing pathways and joining layouts. Experiment shows that our algorithm is able to give comprehensible visualization for pathways with hierarchies, cycles as well as complex structures. It clearly renders the global component structures as well as the local structure in each component. In addition, it runs very fast, and gives better visualization for many examples from previous related research. 2009 Elsevier B.V. All rights reserved.

A hierarchical structure for risk criteria applicable to nuclear power plants

International Nuclear Information System (INIS)

Hall, R.E.; Mitra, S.P.

1982-01-01

This paper discusses the development of a hierarchical structure for risk criteria applicable to nuclear power plants. The structure provides a unified framework to systematically analyze the implications of different types of criteria, each focusing on a particular aspect of nuclear power plant risks. The framework allows investigation of the specific coverage of a particular criterion and comparison of different criteria with regard to areas to which they apply

ORGANIZATIONAL STRUCTURE FOR BUILDINGS RECONSTRUCTION OF HISTORICAL BUILDING OF ODESSA

Directory of Open Access Journals (Sweden)

POSTERNAK I. М.

2016-12-01

Full Text Available Formulation of the problem. As one of perspective forms of integration various complexes act in town-planning structure. In the course of formation of plans of social and economic development of large cities even more often there is a situation when for increase of efficiency of used resources concentration of efforts is necessary not simply, but also new progressive forms of the organization of building manufacture. Purpose. To offer the organizational structure using in practice the saved up scientific and technical potential for reconstruction of buildings of historical building of Odessa 1820 … 1920 years under standards power efficiency and to execute researches engineering architectonics residential buildings of historical building of a city of Odessa. Conclusion. It is offered to create in the city of Odessa "the Corporate scientific and technical complex town-planning power reconstruction "CSTC T-PPR", as innovative organizational structure which uses in practice the saved up scientific and technical potential for reconstruction of buildings of historical building of Odessa under standards power efficiency. It is considered engineering architectonics residential buildings of historical building of a city of Odessa, in particular, not looking on diverse buildings of inhabited appointment of Odessa, for them there are defining factors on which probably to make their grouping and at the same time to allocate the general lines inherent to a housing estate as a whole. It is resulted a general characteristic and classification of residential buildings of historical building of a city of Odessa ХІХ … beginnings ХХ centuries It is allocated and expanded classification of such buildings of inhabited appointment by duration of residing at them.

ORGANIZATIONAL STRUCTURE FOR RECONSTRUCTION OF BUILDINGS HISTORICAL BUILDING OF ODESSA

Directory of Open Access Journals (Sweden)

POSTERNAK I. М.

2017-05-01

Full Text Available Summary. Raising of problem. As one of perspective forms of integration various complexes act in town- planning structure. In the course of formation of plans of social and economic development of large cities even more often there is a situation when for increase of efficiency of used resources concentration of efforts is necessary not simply, but also new progressive forms of the organization of building manufacture. Purpose. To offer the organizational structure using in practice the saved up scientific and technical potential for reconstruction of buildings of historical building of Odessa 1820 … 1920 years under standards power efficiency and to execute researches engineering architectonics residential buildings of historical building of a city of Odessa. Conclusion. It is offered to create in the city of Odessa "the Corporate scientific and technical complex town-planning power reconstruction "CSTC T-PPR", as innovative organizational structure which uses in practice the saved up scientific and technical potential for reconstruction of buildings of historical building of Odessa under standards power efficiency. It is considered engineering architectonics residential buildings of historical building of a city of Odessa, in particular, not looking on diverse buildings of inhabited appointment of Odessa, for them there are defining factors on which probably to make their grouping and at the same time to allocate the general lines inherent to a housing estate as a whole. It is resulted a general characteristic and classification of residential buildings of historical building of a city of Odessa ХІХ beginnings ХХ centuries It is allocated and expanded classification of such buildings of inhabited appointment by duration of residing at them.

Durable Lotus-effect surfaces with hierarchical structure using micro- and nanosized hydrophobic silica particles.

Science.gov (United States)

Ebert, Daniel; Bhushan, Bharat

2012-02-15

Surfaces with a very high apparent water contact angle (CA) and low water contact angle hysteresis (CAH) exhibit many useful characteristics, among them extreme water repellency, low drag for fluid flow, and a self-cleaning effect. The leaf of the Lotus plant (Nelumbo nucifera) achieves these properties using a hierarchical structure with roughness on both the micro- and nanoscale. It is of great interest to create durable surfaces with the so-called "Lotus effect" for many important applications. In this study, hierarchically structured surfaces with Lotus-effect properties were fabricated using micro- and nanosized hydrophobic silica particles and a simple spray method. In addition, hierarchically structured surfaces were prepared by spraying a nanoparticulate coating over a micropatterned surface. To examine the similarities between surfaces using microparticles versus a uniform micropattern as the microstructure, CA and CAH were compared across a range of pitch values for the two types of microstructures. Wear experiments were performed using an atomic force microscope (AFM), a ball-on-flat tribometer, and a water jet apparatus to verify multiscale wear resistance. These surfaces have potential uses in engineering applications requiring Lotus-effect properties and high durability. Copyright © 2011 Elsevier Inc. All rights reserved.

Role of local assembly in the hierarchical crystallization of associating colloidal hard hemispheres

Science.gov (United States)

Lei, Qun-li; Hadinoto, Kunn; Ni, Ran

2017-10-01

Hierarchical self-assembly consisting of local associations of simple building blocks for the formation of complex structures widely exists in nature, while the essential role of local assembly remains unknown. In this work, by using computer simulations, we study a simple model system consisting of associating colloidal hemispheres crystallizing into face-centered-cubic crystals comprised of spherical dimers of hemispheres, focusing on the effect of dimer formation on the hierarchical crystallization. We found that besides assisting the crystal nucleation because of increasing the symmetry of building blocks, the association between hemispheres can also induce both reentrant melting and reentrant crystallization depending on the range of interaction. Especially when the interaction is highly sticky, we observe a novel reentrant crystallization of identical crystals, which melt only in a certain temperature range. This offers another axis in fabricating responsive crystalline materials by tuning the fluctuation of local association.

Hierarchically structured catalysts for cascade and selective steam reforming/hydrodeoxygenation reactions.

Science.gov (United States)

Sun, Junming; Karim, Ayman M; Li, Xiaohong Shari; Rainbolt, James; Kovarik, Libor; Shin, Yongsoon; Wang, Yong

2015-12-04

We report a hierarchically structured catalyst with steam reforming and hydrodeoxygenation functionalities being deposited in the micropores and macropores, respectively. The catalyst is highly efficient to upgrade the pyrolysis vapors of pine forest product residual, resulting in a dramatically decreased acid content and increased hydrocarbon yield without external H2 supply.

Hierarchical model generation for architecture reconstruction using laser-scanned point clouds

Science.gov (United States)

Ning, Xiaojuan; Wang, Yinghui; Zhang, Xiaopeng

2014-06-01

Architecture reconstruction using terrestrial laser scanner is a prevalent and challenging research topic. We introduce an automatic, hierarchical architecture generation framework to produce full geometry of architecture based on a novel combination of facade structures detection, detailed windows propagation, and hierarchical model consolidation. Our method highlights the generation of geometric models automatically fitting the design information of the architecture from sparse, incomplete, and noisy point clouds. First, the planar regions detected in raw point clouds are interpreted as three-dimensional clusters. Then, the boundary of each region extracted by projecting the points into its corresponding two-dimensional plane is classified to obtain detailed shape structure elements (e.g., windows and doors). Finally, a polyhedron model is generated by calculating the proposed local structure model, consolidated structure model, and detailed window model. Experiments on modeling the scanned real-life buildings demonstrate the advantages of our method, in which the reconstructed models not only correspond to the information of architectural design accurately, but also satisfy the requirements for visualization and analysis.

Construction of 3D Arrays of Cylindrically Hierarchical Structures with ZnO Nanorods Hydrothermally Synthesized on Optical Fiber Cores

Directory of Open Access Journals (Sweden)

Weixuan Jing

2014-01-01

Full Text Available With ZnO nanorods hydrothermally synthesized on manually assembled arrays of optical fiber cores, 3D arrays of ZnO nanorod-based cylindrically hierarchical structures with nominal pitch 250 μm or 375 μm were constructed. Based on micrographs of scanning electron microscopy and image processing operators of MATLAB software, the 3D arrays of cylindrically hierarchical structures were quantitatively characterized. The values of the actual diameters, the actual pitches, and the parallelism errors suggest that the process capability of the manual assembling is sufficient and the quality of the 3D arrays of cylindrically hierarchical structures is acceptable. The values of the characteristic parameters such as roughness, skewness, kurtosis, correlation length, and power spectrum density show that the surface morphologies of the cylindrically hierarchical structures not only were affected significantly by Zn2+ concentration of the growth solution but also were anisotropic due to different curvature radii of the optical fiber core at side and front view.

INFOGRAPHIC MODELING OF THE HIERARCHICAL STRUCTURE OF THE MANAGEMENT SYSTEM EXPOSED TO AN INNOVATIVE CONFLICT

Directory of Open Access Journals (Sweden)

Chulkov Vitaliy Olegovich

2012-12-01

Full Text Available This article deals with the infographic modeling of hierarchical management systems exposed to innovative conflicts. The authors analyze the facts that serve as conflict drivers in the construction management environment. The reasons for innovative conflicts include changes in hierarchical structures of management systems, adjustment of workers to new management conditions, changes in the ideology, etc. Conflicts under consideration may involve contradictions between requests placed by customers and the legislation, any risks that may originate from the above contradiction, conflicts arising from any failure to comply with any accepted standards of conduct, etc. One of the main objectives of the theory of hierarchical structures is to develop a model capable of projecting potential innovative conflicts. Models described in the paper reflect dynamic changes in patterns of external impacts within the conflict area. The simplest model element is a monad, or an indivisible set of characteristics of participants at the pre-set level. Interaction between two monads forms a diad. Modeling of situations that involve a different number of monads, diads, resources and impacts can improve methods used to control and manage hierarchical structures in the construction industry. However, in the absence of any mathematical models employed to simulate conflict-related events, processes and situations, any research into, projection and management of interpersonal and group-to-group conflicts are to be performed in the legal environment

Flower-like hierarchical structures consisting of porous single-crystalline ZnO nanosheets and their gas sensing properties to volatile organic compounds (VOCs)

Energy Technology Data Exchange (ETDEWEB)

Meng, Fanli, E-mail: flmeng@iim.ac.cn [Research Center for Biomimetic Functional Materials and Sensing Devices, Institute of Intelligent Machines, Chinese Academy of Sciences, Hefei 230031 (China); Department of Materials Science and Engineering, University of California, Los Angeles, CA 90095 (United States); Hou, Nannan [Research Center for Biomimetic Functional Materials and Sensing Devices, Institute of Intelligent Machines, Chinese Academy of Sciences, Hefei 230031 (China); Department of Chemistry, University of Science and Technology of China, Hefei 230026 (China); Ge, Sheng [Department of Mechanical and Automotive Engineering, Anhui Polytechnic University, Wuhu 241000 (China); Sun, Bai [Research Center for Biomimetic Functional Materials and Sensing Devices, Institute of Intelligent Machines, Chinese Academy of Sciences, Hefei 230031 (China); Jin, Zhen, E-mail: zjin@iim.ac.cn [Research Center for Biomimetic Functional Materials and Sensing Devices, Institute of Intelligent Machines, Chinese Academy of Sciences, Hefei 230031 (China); Shen, Wei; Kong, Lingtao; Guo, Zheng [Research Center for Biomimetic Functional Materials and Sensing Devices, Institute of Intelligent Machines, Chinese Academy of Sciences, Hefei 230031 (China); Sun, Yufeng, E-mail: sunyufeng118@126.com [Department of Mechanical and Automotive Engineering, Anhui Polytechnic University, Wuhu 241000 (China); Wu, Hao; Wang, Chen [Department of Materials Science and Engineering, University of California, Los Angeles, CA 90095 (United States); Li, Minqiang [Research Center for Biomimetic Functional Materials and Sensing Devices, Institute of Intelligent Machines, Chinese Academy of Sciences, Hefei 230031 (China)

2015-03-25

Highlights: • Flower-like hierarchical structures consisting of porous single-crystalline ZnO nanosheets were synthesized. • The flower-like hierarchical structured ZnO exhibited higher response and shorter response and recovery times. • The sensing mechanism of the flower-like hierarchical has been systematically analyzed. - Abstract: Flower-like hierarchical structures consisting of porous single-crystalline ZnO nanosheets (FHPSCZNs) were synthesized by a one-pot wet-chemical method followed by an annealing treatment, which combined the advantages between flower-like hierarchical structure and porous single-crystalline structure. XRD, SEM and HRTEM were used to characterize the synthesized FHPSCZN samples. The sensing properties of the FHPSCZN sensor were also investigated by comparing with ZnO powder sensor, which exhibited higher response and shorter response and recovery times. The sensing mechanism of the FHPSCZN sensor has been further analyzed from the aspects of electronic transport and gas diffusion.

Flower-like hierarchical structures consisting of porous single-crystalline ZnO nanosheets and their gas sensing properties to volatile organic compounds (VOCs)

International Nuclear Information System (INIS)

Meng, Fanli; Hou, Nannan; Ge, Sheng; Sun, Bai; Jin, Zhen; Shen, Wei; Kong, Lingtao; Guo, Zheng; Sun, Yufeng; Wu, Hao; Wang, Chen; Li, Minqiang

2015-01-01

Highlights: • Flower-like hierarchical structures consisting of porous single-crystalline ZnO nanosheets were synthesized. • The flower-like hierarchical structured ZnO exhibited higher response and shorter response and recovery times. • The sensing mechanism of the flower-like hierarchical has been systematically analyzed. - Abstract: Flower-like hierarchical structures consisting of porous single-crystalline ZnO nanosheets (FHPSCZNs) were synthesized by a one-pot wet-chemical method followed by an annealing treatment, which combined the advantages between flower-like hierarchical structure and porous single-crystalline structure. XRD, SEM and HRTEM were used to characterize the synthesized FHPSCZN samples. The sensing properties of the FHPSCZN sensor were also investigated by comparing with ZnO powder sensor, which exhibited higher response and shorter response and recovery times. The sensing mechanism of the FHPSCZN sensor has been further analyzed from the aspects of electronic transport and gas diffusion

Synergistic effects from graphene and carbon nanotubes endow ordered hierarchical structure foams with a combination of compressibility, super-elasticity and stability and potential application as pressure sensors.

Science.gov (United States)

Kuang, Jun; Dai, Zhaohe; Liu, Luqi; Yang, Zhou; Jin, Ming; Zhang, Zhong

2015-01-01

Nanostructured carbon material based three-dimensional porous architectures have been increasingly developed for various applications, e.g. sensors, elastomer conductors, and energy storage devices. Maintaining architectures with good mechanical performance, including elasticity, load-bearing capacity, fatigue resistance and mechanical stability, is prerequisite for realizing these functions. Though graphene and CNT offer opportunities as nanoscale building blocks, it still remains a great challenge to achieve good mechanical performance in their microarchitectures because of the need to precisely control the structure at different scales. Herein, we fabricate a hierarchical honeycomb-like structured hybrid foam based on both graphene and CNT. The resulting materials possess excellent properties of combined high specific strength, elasticity and mechanical stability, which cannot be achieved in neat CNT and graphene foams. The improved mechanical properties are attributed to the synergistic-effect-induced highly organized, multi-scaled hierarchical architectures. Moreover, with their excellent electrical conductivity, we demonstrated that the hybrid foams could be used as pressure sensors in the fields related to artificial skin.

Fabrication of three-dimensional poly(ε-caprolactone) scaffolds with hierarchical pore structures for tissue engineering

Energy Technology Data Exchange (ETDEWEB)

Zhang, Qingchun [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); Luo, Houyong [State Key Laboratory of Bioreactor Engineering, School of Bioengineering, East China University of Science and Technology, Shanghai 200237 (China); Zhang, Yan [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); Zhou, Yan [State Key Laboratory of Bioreactor Engineering, School of Bioengineering, East China University of Science and Technology, Shanghai 200237 (China); Ye, Zhaoyang, E-mail: zhaoyangye@ecust.edu.cn [State Key Laboratory of Bioreactor Engineering, School of Bioengineering, East China University of Science and Technology, Shanghai 200237 (China); Tan, Wensong [State Key Laboratory of Bioreactor Engineering, School of Bioengineering, East China University of Science and Technology, Shanghai 200237 (China); Lang, Meidong, E-mail: mdlang@ecust.edu.cn [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)

2013-05-01

The physical properties of tissue engineering scaffolds such as microstructures play important roles in controlling cellular behaviors and neotissue formation. Among them, the pore size stands out as a key determinant factor. In the present study, we aimed to fabricate porous scaffolds with pre-defined hierarchical pore sizes, followed by examining cell growth in these scaffolds. This hierarchical porous microstructure was implemented via integrating different pore-generating methodologies, including salt leaching and thermal induced phase separation (TIPS). Specifically, large (L, 200–300 μm), medium (M, 40–50 μm) and small (S, < 10 μm) pores were able to be generated. As such, three kinds of porous scaffolds with a similar porosity of ∼ 90% creating pores of either two (LS or MS) or three (LMS) different sizes were successfully prepared. The number fractions of different pores in these scaffolds were determined to confirm the hierarchical organization of pores. It was found that the interconnectivity varied due to the different pore structures. Besides, these scaffolds demonstrated similar compressive moduli under dry and hydrated states. The adhesion, proliferation, and spatial distribution of human fibroblasts within the scaffolds during a 14-day culture were evaluated with MTT assay and fluorescence microscopy. While all three scaffolds well supported the cell attachment and proliferation, the best cell spatial distribution inside scaffolds was achieved with LMS, implicating that such a controlled hierarchical microstructure would be advantageous in tissue engineering applications. Highlights: ► The scaffolds with dual-pore and triple-pore structures were fabricated. ► Triple-pore structure had better interconnectivity than dual-pore structures. ► Better cell migration and distribution were found on the triple-pore structures. ► The medium pore size (45–50 μm) was appropriate for cell migration. ► Scaffolds with triple-pore structure

7 CFR 51.56 - Buildings and structures.

Science.gov (United States)

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false Buildings and structures. 51.56 Section 51.56... § 51.56 Buildings and structures. The packing plant buildings shall be properly constructed and... be sufficient light consistent with the use to which the particular portion of the building is...

Hierarchical organization in the temporal structure of infant-direct speech and song.

Science.gov (United States)

Falk, Simone; Kello, Christopher T

2017-06-01

Caregivers alter the temporal structure of their utterances when talking and singing to infants compared with adult communication. The present study tested whether temporal variability in infant-directed registers serves to emphasize the hierarchical temporal structure of speech. Fifteen German-speaking mothers sang a play song and told a story to their 6-months-old infants, or to an adult. Recordings were analyzed using a recently developed method that determines the degree of nested clustering of temporal events in speech. Events were defined as peaks in the amplitude envelope, and clusters of various sizes related to periods of acoustic speech energy at varying timescales. Infant-directed speech and song clearly showed greater event clustering compared with adult-directed registers, at multiple timescales of hundreds of milliseconds to tens of seconds. We discuss the relation of this newly discovered acoustic property to temporal variability in linguistic units and its potential implications for parent-infant communication and infants learning the hierarchical structures of speech and language. Copyright © 2017 Elsevier B.V. All rights reserved.

Rapid fabrication of hierarchically structured supramolecular nanocomposite thin films in one minute

Energy Technology Data Exchange (ETDEWEB)

Xu, Ting; Kao, Joseph

2016-11-08

Functional nanocomposites containing nanoparticles of different chemical compositions may exhibit new properties to meet demands for advanced technology. It is imperative to simultaneously achieve hierarchical structural control and to develop rapid, scalable fabrication to minimize degradation of nanoparticle properties and for compatibility with nanomanufacturing. The assembly kinetics of supramolecular nanocomposite in thin films is governed by the energetic cost arising from defects, the chain mobility, and the activation energy for inter-domain diffusion. By optimizing only one parameter, the solvent fraction in the film, the assembly kinetics can be precisely tailored to produce hierarchically structured thin films of supramolecular nanocomposites in approximately one minute. Moreover, the strong wavelength dependent optical anisotropy in the nanocomposite highlights their potential applications for light manipulation and information transmission. The present invention opens a new avenue in designing manufacture-friendly continuous processing for the fabrication of functional nanocomposite thin films.

Synthesis and properties of ZnFe{sub 2}O{sub 4} replica with biological hierarchical structure

Energy Technology Data Exchange (ETDEWEB)

Liu, Hongyan; Guo, Yiping, E-mail: ypguo@sjtu.edu.cn; Zhang, Yangyang; Wu, Fen; Liu, Yun; Zhang, Di, E-mail: zhangdi@sjtu.edu.cn

2013-09-20

Highlights: • ZFO replica with hierarchical structure was synthesized from butterfly wings. • Biotemplate has a significant impact on the properties of ZFO material. • Our method opens up new avenues for the synthesis of spinel ferrites. -- Abstract: ZnFe{sub 2}O{sub 4} replica with biological hierarchical structure was synthesized from Papilio paris by a sol–gel method followed by calcination. The crystallographic structure and morphology of the obtained samples were characterized by X-ray diffraction, field-emission scanning electron microscope, and transmittance electron microscope. The results showed that the hierarchical structures were retained in the ZFO replica of spinel structure. The magnetic behavior of such novel products was measured by a vibrating sample magnetometer. A superparamagnetism-like behavior was observed due to nanostructuration size effects. In addition, the ZFO replica with “quasi-honeycomb-like structure” showed a much higher specific capacitance of 279.4 F g{sup −1} at 10 mV s{sup −1} in comparison with ZFO powder of 137.3 F g{sup −1}, attributing to the significantly increased surface area. These results demonstrated that ZFO replica is a promising candidate for novel magnetic devices and supercapacitors.

Star Cluster Structure from Hierarchical Star Formation

Science.gov (United States)

Grudic, Michael; Hopkins, Philip; Murray, Norman; Lamberts, Astrid; Guszejnov, David; Schmitz, Denise; Boylan-Kolchin, Michael

2018-01-01

Young massive star clusters (YMCs) spanning 104-108 M⊙ in mass generally have similar radial surface density profiles, with an outer power-law index typically between -2 and -3. This similarity suggests that they are shaped by scale-free physics at formation. Recent multi-physics MHD simulations of YMC formation have also produced populations of YMCs with this type of surface density profile, allowing us to narrow down the physics necessary to form a YMC with properties as observed. We show that the shallow density profiles of YMCs are a natural result of phase-space mixing that occurs as they assemble from the clumpy, hierarchically-clustered configuration imprinted by the star formation process. We develop physical intuition for this process via analytic arguments and collisionless N-body experiments, elucidating the connection between star formation physics and star cluster structure. This has implications for the early-time structure and evolution of proto-globular clusters, and prospects for simulating their formation in the FIRE cosmological zoom-in simulations.

Reliability and Hierarchical Structure of DSM-5 Pathological Traits in a Danish Mixed Sample

DEFF Research Database (Denmark)

Bo, Sune; Bach, Bo; Mortensen, Erik Lykke

2016-01-01

In this study we assessed the DSM-5 trait model in a large Danish sample (n = 1,119) with respect to reliability of the applied Danish version of the Personality Inventory for DSM-5 (PID-5) self-report form by means of internal consistency and item discrimination. In addition, we tested whether...... the five-factor structure of the DSM-5 trait model can be replicated in a Danish independent sample using the PID-5 self-report form. Finally, we examined the hierarchical structure of DSM-5 traits. In terms of internal consistency and item discrimination, the applied PID-5 scales were generally found...... reliable and functional; our data resembled the five-factor structure of previous findings, and we identified a hierarchical structure from one to five factors that was conceptually reasonable and corresponded with existing findings. These results support the new DSM-5 trait model and suggest that it can...

How Are Researching and Reading Interwieved during Retrieval from Hierarchically Structured Documents?

DEFF Research Database (Denmark)

Hertzum, Morten; Lalmas, M.; Frøkjær, Erik

2001-01-01

Effective use of information retrieval systems requires that users know when to – temporarily – cease searching to do some reading and where to start reading. In hierarchically structured documents, users can to some extent interchange searching and reading by entering the text at different levels...... information retrieval systems could exploit document structure to return the best points to support reading, rather than merely hits...

Eigenspaces of networks reveal the overlapping and hierarchical community structure more precisely

International Nuclear Information System (INIS)

Ma, Xiaoke; Gao, Lin; Yong, Xuerong

2010-01-01

Identifying community structure is fundamental for revealing the structure–functionality relationship in complex networks, and spectral algorithms have been shown to be powerful for this purpose. In a traditional spectral algorithm, each vertex of a network is embedded into a spectral space by making use of the eigenvectors of the adjacency matrix or Laplacian matrix of the graph. In this paper, a novel spectral approach for revealing the overlapping and hierarchical community structure of complex networks is proposed by not only using the eigenvalues and eigenvectors but also the properties of eigenspaces of the networks involved. This gives us a better characterization of community. We first show that the communicability between a pair of vertices can be rewritten in term of eigenspaces of a network. An agglomerative clustering algorithm is then presented to discover the hierarchical communities using the communicability matrix. Finally, these overlapping vertices are discovered with the corresponding eigenspaces, based on the fact that the vertices more densely connected amongst one another are more likely to be linked through short cycles. Compared with the traditional spectral algorithms, our algorithm can identify both the overlapping and hierarchical community without increasing the time complexity O(n 3 ), where n is the size of the network. Furthermore, our algorithm can also distinguish the overlapping vertices from bridges. The method is tested by applying it to some computer-generated and real-world networks. The experimental results indicate that our algorithm can reveal community structure more precisely than the traditional spectral approaches

Hierarchically porous Ni monolith@branch-structured NiCo2O4 for high energy density supercapacitors

Directory of Open Access Journals (Sweden)

Mengjie Xu

2016-06-01

Full Text Available A variety of NiCo2O4 nanostrucutures ranging from nanowire to nanoplate and branched structures were successfully prepared via a simple hydrothermal process. The experimental results show that NiCo2O4 with branched structures possesses the best overall electrochemical performance. The improvement of energy density was explored in terms of hierarchically three-dimensional (3D metal substrates and a high specific area capacitance, and area energy density is obtained with hierarchically porous Ni monolith synthesized through a controlled combustion procedure.

Axiomatizations of Banzhaf Permisson Values for Games with a Hierarchical Permission Structure.

NARCIS (Netherlands)

van den Brink, J.R.

2010-01-01

In games with a permission structure it is assumed that players in a cooperative transferable utility game are hierarchically ordered in the sense that there are players that need permission from other players before they are allowed to cooperate. We provide axiomatic characterizations of Banzhaf

Hierarchically structured lithium titanate for ultrafast charging in long-life high capacity batteries

Science.gov (United States)

Odziomek, Mateusz; Chaput, Frédéric; Rutkowska, Anna; Świerczek, Konrad; Olszewska, Danuta; Sitarz, Maciej; Lerouge, Frédéric; Parola, Stephane

2017-05-01

High-performance Li-ion batteries require materials with well-designed and controlled structures on nanometre and micrometre scales. Electrochemical properties can be enhanced by reducing crystallite size and by manipulating structure and morphology. Here we show a method for preparing hierarchically structured Li4Ti5O12 yielding nano- and microstructure well-suited for use in lithium-ion batteries. Scalable glycothermal synthesis yields well-crystallized primary 4-8 nm nanoparticles, assembled into porous secondary particles. X-ray photoelectron spectroscopy reveals presence of Ti+4 only; combined with chemical analysis showing lithium deficiency, this suggests oxygen non-stoichiometry. Electron microscopy confirms hierarchical morphology of the obtained material. Extended cycling tests in half cells demonstrates capacity of 170 mAh g-1 and no sign of capacity fading after 1,000 cycles at 50C rate (charging completed in 72 s). The particular combination of nanostructure, microstructure and non-stoichiometry for the prepared lithium titanate is believed to underlie the observed electrochemical performance of material.

Self-assembled biomimetic superhydrophobic hierarchical arrays.

Science.gov (United States)

Yang, Hongta; Dou, Xuan; Fang, Yin; Jiang, Peng

2013-09-01

Here, we report a simple and inexpensive bottom-up technology for fabricating superhydrophobic coatings with hierarchical micro-/nano-structures, which are inspired by the binary periodic structure found on the superhydrophobic compound eyes of some insects (e.g., mosquitoes and moths). Binary colloidal arrays consisting of exemplary large (4 and 30 μm) and small (300 nm) silica spheres are first assembled by a scalable Langmuir-Blodgett (LB) technology in a layer-by-layer manner. After surface modification with fluorosilanes, the self-assembled hierarchical particle arrays become superhydrophobic with an apparent water contact angle (CA) larger than 150°. The throughput of the resulting superhydrophobic coatings with hierarchical structures can be significantly improved by templating the binary periodic structures of the LB-assembled colloidal arrays into UV-curable fluoropolymers by a soft lithography approach. Superhydrophobic perfluoroether acrylate hierarchical arrays with large CAs and small CA hysteresis can be faithfully replicated onto various substrates. Both experiments and theoretical calculations based on the Cassie's dewetting model demonstrate the importance of the hierarchical structure in achieving the final superhydrophobic surface states. Copyright © 2013 Elsevier Inc. All rights reserved.

Hierarchically structured identification and classification method for vibrational monitoring of reactor components

International Nuclear Information System (INIS)

Saedtler, E.

1981-01-01

The dissertation discusses: 1. Approximative filter algorithms for identification of systems and hierarchical structures. 2. Adaptive statistical pattern recognition and classification. 3. Parameter selection, extraction, and modelling for an automatic control system. 4. Design of a decision tree and an adaptive diagnostic system. (orig./RW) [de

Facile and tunable synthesis of hierarchical mesoporous silica materials ranging from flower structure with wrinkled edges to hollow structure with coarse surface

Energy Technology Data Exchange (ETDEWEB)

Hao, Nanjing, E-mail: nanjing.hao@dartmouth.edu [Dartmouth College, Thayer School of Engineering (United States); Li, Laifeng; Tang, Fangqiong, E-mail: tangfq@mail.ipc.ac.cn [Chinese Academy of Sciences, Technical Institute of Physics and Chemistry (China)

2016-11-15

Mesoporous silica materials have attracted great attention in many fields. However, facile and tunable synthesis of hierarchical mesoporous silica structures is still a big challenge, and thus the development of them still lags behind. Herein, well-defined mesoporous silica flower structure with wrinkled edges and mesoporous silica hollow structure with coarse surface were synthesized simply by using poly(vinylpyrrolidone) and hexadecylamine as cotemplates in different water/ethanol solvent systems. The shape evolution from flower to hollow can be easily realized by tuning the volume ratio of water to ethanol, and the yields of both materials can reach gram scale. The formation mechanisms of mesoporous silica flower and hollow structures were also experimentally investigated and discussed. These novel hierarchical structures having unique physicochemical properties may bring many interesting insights into scientific research and technological application.

Organosilane with gemini-type structure as the mesoporogen for synthesis of hierarchical porous ZSM-5 zeolite

KAUST Repository

Zhu, Haibo

2016-02-08

A new kind of organosilane (1,6-bis (diethyl(3-trimethoxysilylpropyl)ammonium) hexane bromide) with a gemini-type structure was prepared and used as a mesoporogen for the synthesis of hierarchical porous ZSM-5 zeolite. There are two quaternary ammonium centers along with double hydrolysable -RSi(OMe)3 fragments in the organosilane, which results in a strong interaction between this mesoporogen and silica-alumina gel. The organosilane can be easily incorporated into ZSM-5 zeolite structure during the crystallization process, and it was finally removed by calcination leading to secondary pores in ZSM-5. The synthesized ZSM-5 has been systematically studied by XRD, nitrogen adsorption, SEM, TEM, TG and solid-state one-dimensional (1D) and two-dimensional (2D) NMR, which reveals information on its detailed structure. It has a hierarchical porosity system, which combines the intrinsic micropores coming from the crystalline structure and irregular mesopores created by the organosilane template. Moreover, the mesoposity including pore size and volume within ZSM-5 can be systematically tuned by changing the organosilane/TEOS ratios, which confirms this organosilane has high flexibility of using as template for the synthesis of hierarchical porous zeolite.

Organosilane with gemini-type structure as the mesoporogen for synthesis of hierarchical porous ZSM-5 zeolite

KAUST Repository

Zhu, Haibo; Abou-Hamad, Edy; Chen, Yin; Saih, Youssef; Liu, Weibing; Basset, Jean-Marie; Samal, Akshaya Kumar

2016-01-01

A new kind of organosilane (1,6-bis (diethyl(3-trimethoxysilylpropyl)ammonium) hexane bromide) with a gemini-type structure was prepared and used as a mesoporogen for the synthesis of hierarchical porous ZSM-5 zeolite. There are two quaternary ammonium centers along with double hydrolysable -RSi(OMe)3 fragments in the organosilane, which results in a strong interaction between this mesoporogen and silica-alumina gel. The organosilane can be easily incorporated into ZSM-5 zeolite structure during the crystallization process, and it was finally removed by calcination leading to secondary pores in ZSM-5. The synthesized ZSM-5 has been systematically studied by XRD, nitrogen adsorption, SEM, TEM, TG and solid-state one-dimensional (1D) and two-dimensional (2D) NMR, which reveals information on its detailed structure. It has a hierarchical porosity system, which combines the intrinsic micropores coming from the crystalline structure and irregular mesopores created by the organosilane template. Moreover, the mesoposity including pore size and volume within ZSM-5 can be systematically tuned by changing the organosilane/TEOS ratios, which confirms this organosilane has high flexibility of using as template for the synthesis of hierarchical porous zeolite.

An interference cancellation strategy for broadcast in hierarchical cell structure

KAUST Repository

Yang, Yuli; Aï ssa, Sonia; Eltawil, Ahmed M.; Salama, Khaled N.

2014-01-01

In this paper, a hierarchical cell structure is considered, where public safety broadcasting is fulfilled in a femtocell located within a macrocell. In the femtocell, also known as local cell, an access point broadcasts to each local node (LN) over an orthogonal frequency sub-band independently. Since the local cell shares the spectrum licensed to the macrocell, a given LN is interfered by transmissions of the macrocell user (MU) in the same sub-band. To improve the broadcast performance in the local cell, a novel scheme is proposed to mitigate the interference from the MU to the LN while achieving diversity gain. For the sake of performance evaluation, ergodic capacity of the proposed scheme is quantified and a corresponding closed-form expression is obtained. By comparing with the traditional scheme that suffers from the MU's interference, numerical results substantiate the advantage of the proposed scheme and provide a useful tool for the broadcast design in hierarchical cell systems.

An interference cancellation strategy for broadcast in hierarchical cell structure

KAUST Repository

Yang, Yuli

2014-12-01

In this paper, a hierarchical cell structure is considered, where public safety broadcasting is fulfilled in a femtocell located within a macrocell. In the femtocell, also known as local cell, an access point broadcasts to each local node (LN) over an orthogonal frequency sub-band independently. Since the local cell shares the spectrum licensed to the macrocell, a given LN is interfered by transmissions of the macrocell user (MU) in the same sub-band. To improve the broadcast performance in the local cell, a novel scheme is proposed to mitigate the interference from the MU to the LN while achieving diversity gain. For the sake of performance evaluation, ergodic capacity of the proposed scheme is quantified and a corresponding closed-form expression is obtained. By comparing with the traditional scheme that suffers from the MU\\'s interference, numerical results substantiate the advantage of the proposed scheme and provide a useful tool for the broadcast design in hierarchical cell systems.

A top-down approach for fabricating free-standing bio-carbon supercapacitor electrodes with a hierarchical structure.

Science.gov (United States)

Li, Yingzhi; Zhang, Qinghua; Zhang, Junxian; Jin, Lei; Zhao, Xin; Xu, Ting

2015-09-23

Biomass has delicate hierarchical structures, which inspired us to develop a cost-effective route to prepare electrode materials with rational nanostructures for use in high-performance storage devices. Here, we demonstrate a novel top-down approach for fabricating bio-carbon materials with stable structures and excellent diffusion pathways; this approach is based on carbonization with controlled chemical activation. The developed free-standing bio-carbon electrode exhibits a high specific capacitance of 204 F g(-1) at 1 A g(-1); good rate capability, as indicated by the residual initial capacitance of 85.5% at 10 A g(-1); and a long cycle life. These performance characteristics are attributed to the outstanding hierarchical structures of the electrode material. Appropriate carbonization conditions enable the bio-carbon materials to inherit the inherent hierarchical texture of the original biomass, thereby facilitating effective channels for fast ion transfer. The macropores and mesopores that result from chemical activation significantly increase the specific surface area and also play the role of temporary ion-buffering reservoirs, further shortening the ionic diffusion distance.

Biomimetic "Cactus Spine" with Hierarchical Groove Structure for Efficient Fog Collection.

Science.gov (United States)

Bai, Fan; Wu, Juntao; Gong, Guangming; Guo, Lin

2015-07-01

A biomimetic "cactus spine" with hierarchical groove structure is designed and fabricated using simple electrospinning. This novel artificial cactus spine possesses excellent fog collection and water transportation ability. A model cactus equipped with artificial spines also shows a great water storage capacity. The results can be helpful in the development of water collectors and may make a contribution to the world water crisis.

Hierarchical Structure in Semicrystalline Polymers Tethered to Nanospheres

KAUST Repository

Kim, Sung A

2014-01-28

We report on structural and dynamic transitions of polymers tethered to nanoparticles. In particular, we use X-ray diffraction, vibrational spectroscopy, and thermal measurements to investigate multiscale structure and dynamic transitions of poly(ethylene glycol) (PEG) chains densely grafted to SiO2 nanoparticles. The approach used for synthesizing these hybrid particles leads to homogeneous SiO2-PEG composites with polymer grafting densities as high as 1.5 chains/nm2, which allows the hybrid materials to exist as self-suspended suspensions with distinct hierarchical structure and thermal properties. On angstrom and nanometer length scales, the tethered PEG chains exhibit more dominant TTG conformations and helix unit cell structure, in comparison to the untethered polymer. The nanoparticle tethered PEG chains are also reported to form extended crystallites on tens of nanometers length scales and to exhibit more stable crystalline structure on small dimensions. On length scales comparable to the size of each hybrid SiO 2-PEG unit, the materials are amorphous presumably as a result of the difficulty fitting the nanoparticle anchors into the PEG crystal lattice. This structural change produces large effects on the thermal transitions of PEG molecules tethered to nanoparticles. © 2014 American Chemical Society.

Electrochemical design of ZnO hierarchical structures for dye-sensitized solar cells

Czech Academy of Sciences Publication Activity Database

Guerin, V. M.; Rathouský, Jiří; Pauporté, T.

2012-01-01

Roč. 102, JUL 2012 (2012), s. 8-14 ISSN 0927-0248 R&D Projects: GA AV ČR KAN100400702 Institutional research plan: CEZ:AV0Z40400503 Keywords : ZnO hierarchical structures * epitaxy * dye-sensitized solar cell Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 4.630, year: 2012

Super-structure and building performance

CSIR Research Space (South Africa)

Van Wyk, Llewellyn V

2010-11-01

Full Text Available The super-structure consists predominantly of the load- and no-load-bearing walls-including all doors and windows and suspended floor slabs. The building envelope plays a significant role in the performance of a building, especially with regard...

Functional annotation of hierarchical modularity.

Directory of Open Access Journals (Sweden)

Kanchana Padmanabhan

Full Text Available In biological networks of molecular interactions in a cell, network motifs that are biologically relevant are also functionally coherent, or form functional modules. These functionally coherent modules combine in a hierarchical manner into larger, less cohesive subsystems, thus revealing one of the essential design principles of system-level cellular organization and function-hierarchical modularity. Arguably, hierarchical modularity has not been explicitly taken into consideration by most, if not all, functional annotation systems. As a result, the existing methods would often fail to assign a statistically significant functional coherence score to biologically relevant molecular machines. We developed a methodology for hierarchical functional annotation. Given the hierarchical taxonomy of functional concepts (e.g., Gene Ontology and the association of individual genes or proteins with these concepts (e.g., GO terms, our method will assign a Hierarchical Modularity Score (HMS to each node in the hierarchy of functional modules; the HMS score and its p-value measure functional coherence of each module in the hierarchy. While existing methods annotate each module with a set of "enriched" functional terms in a bag of genes, our complementary method provides the hierarchical functional annotation of the modules and their hierarchically organized components. A hierarchical organization of functional modules often comes as a bi-product of cluster analysis of gene expression data or protein interaction data. Otherwise, our method will automatically build such a hierarchy by directly incorporating the functional taxonomy information into the hierarchy search process and by allowing multi-functional genes to be part of more than one component in the hierarchy. In addition, its underlying HMS scoring metric ensures that functional specificity of the terms across different levels of the hierarchical taxonomy is properly treated. We have evaluated our

Hierarchical system for autonomous sensing-healing of delamination in large-scale composite structures

International Nuclear Information System (INIS)

Minakuchi, Shu; Sun, Denghao; Takeda, Nobuo

2014-01-01

This study combines our hierarchical fiber-optic-based delamination detection system with a microvascular self-healing material to develop the first autonomous sensing-healing system applicable to large-scale composite structures. In this combined system, embedded vascular modules are connected through check valves to a surface-mounted supply tube of a pressurized healing agent while fiber-optic-based sensors monitor the internal pressure of these vascular modules. When delamination occurs, the healing agent flows into the vascular modules breached by the delamination and infiltrates the damage for healing. At the same time, the pressure sensors identify the damaged modules by detecting internal pressure changes. This paper begins by describing the basic concept of the combined system and by discussing the advantages that arise from its hierarchical nature. The feasibility of the system is then confirmed through delamination infiltration tests. Finally, the hierarchical system is validated in a plate specimen by focusing on the detection and infiltration of the damage. Its self-diagnostic function is also demonstrated. (paper)

Hierarchical core-shell structure of ZnO nanorod@NiO/MoO₂ composite nanosheet arrays for high-performance supercapacitors.

Science.gov (United States)

Hou, Sucheng; Zhang, Guanhua; Zeng, Wei; Zhu, Jian; Gong, Feilong; Li, Feng; Duan, Huigao

2014-08-27

A hierarchical core-shell structure of ZnO nanorod@NiO/MoO2 composite nanosheet arrays on nickel foam substrate for high-performance supercapacitors was constructed by a two-step solution-based method involving two hydrothermal processes followed by a calcination treatment. Compared to one composed of pure NiO/MoO2 composite nanosheets, the hierarchical core-shell structure electrode displays better pseudocapacitive behaviors in 2 M KOH, including high areal specific capacitance values of 1.18 F cm(-2) at 5 mA cm(-2) and 0.6 F cm(-2) at 30 mA cm(-2) as well as relatively good rate capability at high current densities. Furthermore, it also shows remarkable cycle stability, remaining at 91.7% of the initial value even after 4000 cycles at a current density of 10 mA cm(-2). The enhanced pseudocapacitive behaviors are mainly due to the unique hierarchical core-shell structure and the synergistic effect of combining ZnO nanorod arrays and NiO/MoO2 composite nanosheets. This novel hierarchical core-shell structure shows promise for use in next-generation supercapacitors.

Hierarchical structure of the European countries based on debts as a percentage of GDP during the 2000-2011 period

Science.gov (United States)

Kantar, Ersin; Deviren, Bayram; Keskin, Mustafa

2014-11-01

We investigate hierarchical structures of the European countries by using debt as a percentage of Gross Domestic Product (GDP) of the countries as they change over a certain period of time. We obtain the topological properties among the countries based on debt as a percentage of GDP of European countries over the period 2000-2011 by using the concept of hierarchical structure methods (minimal spanning tree, (MST) and hierarchical tree, (HT)). This period is also divided into two sub-periods related to 2004 enlargement of the European Union, namely 2000-2004 and 2005-2011, in order to test various time-window and observe the temporal evolution. The bootstrap techniques is applied to see a value of statistical reliability of the links of the MSTs and HTs. The clustering linkage procedure is also used to observe the cluster structure more clearly. From the structural topologies of these trees, we identify different clusters of countries according to their level of debts. Our results show that by the debt crisis, the less and most affected Eurozone’s economies are formed as a cluster with each other in the MSTs and hierarchical trees.

Hydrothermal synthesis of copper sulfide with novel hierarchical structures and its application in lithium-ion batteries

International Nuclear Information System (INIS)

Chen, Guang-Yi; Wei, Zhi-Yong; Jin, Bo; Zhong, Xiao-Bin; Wang, Heng; Zhang, Wan-Xi; Liang, Ji-Cai; Jiang, Qing

2013-01-01

Novel stick-like CuS hierarchical structures have been fabricated by a hydrothermal approach use β-cyclodextrin as ligand and structure-directing agent. SEM and TEM characterizations show that the CuS stick-like structures are composed of tens to hundreds of well-arranged and self-assembled nanoplates with a thickness of about 25 nm. The mechanism for the formation of the final stick-like hierarchical structures is proposed and discussed. β-cyclodextrin is found to be the key factor in controlling the morphologies. Meanwhile, the possibility of using CuS as the electrode material for lithium ion batteries (LIBs) is studied. Electrochemical measurements reveal that the as-prepared CuS exhibits outstanding cycle stability, indicating that it might find possible application as a cathode material for LIBs in the long term.

Mapping the Hierarchical Layout of the Structural Network of the Macaque Prefrontal Cortex

NARCIS (Netherlands)

Goulas, A.; Uylings, H.B.M.; Stiers, P.

2014-01-01

A consensus on the prefrontal cortex (PFC) holds that it is pivotal for flexible behavior and the integration of the cognitive, affective, and motivational domains. Certain models have been put forth and a dominant model postulates a hierarchical anterior-posterior gradient. The structural

Self-Reconstructed Formation of a One-Dimensional Hierarchical Porous Nanostructure Assembled by Ultrathin TiO2 Nanobelts for Fast and Stable Lithium Storage.

Science.gov (United States)

Liu, Yuan; Yan, Xiaodong; Xu, Bingqing; Lan, Jinle; Yu, Yunhua; Yang, Xiaoping; Lin, Yuanhua; Nan, Cewen

2018-06-06

Owing to their unique structural advantages, TiO 2 hierarchical nanostructures assembled by low-dimensional (LD) building blocks have been extensively used in the energy-storage/-conversion field. However, it is still a big challenge to produce such advanced structures by current synthetic techniques because of the harsh conditions needed to generate primary LD subunits. Herein, a novel one-dimensional (1D) TiO 2 hierarchical porous fibrous nanostructure constructed by TiO 2 nanobelts is synthesized by combining a room-temperature aqueous solution growth mechanism with the electrospinning technology. The nanobelt-constructed 1D hierarchical nanoarchitecture is evolves directly from the amorphous TiO 2 /SiO 2 composite fibers in alkaline solutions at ambient conditions without any catalyst and other reactant. Benefiting from the unique structural features such as 1D nanoscale building blocks, large surface area, and numerous interconnected pores, as well as mixed phase anatase-TiO 2 (B), the optimum 1D TiO 2 hierarchical porous nanostructure shows a remarkable high-rate performance when tested as an anode material for lithium-ion batteries (107 mA h g -1 at ∼10 A g -1 ) and can be used in a hybrid lithium-ion supercapacitor with very stable lithium-storage performance (a capacity retention of ∼80% after 3000 cycles at 2 A g -1 ). The current work presents a scalable and cost-effective method for the synthesis of advanced TiO 2 hierarchical materials for high-power and stable energy-storage/-conversion devices.

Effect of pre-tension on the peeling behavior of a bio-inspired nano-film and a hierarchical adhesive structure

Science.gov (United States)

Peng, Zhilong; Chen, Shaohua

2012-10-01

Inspired by the reversible adhesion behaviors of geckos, the effects of pre-tension in a bio-inspired nano-film and a hierarchical structure on adhesion are studied theoretically. In the case with a uniformly distributing pre-tension in a spatula-like nano-film under peeling, a closed-form solution to a critical peeling angle is derived, below or above which the peel-off force is enhanced or reduced, respectively, compared with the case without pre-tension. The effects of a non-uniformly distributing pre-tension on adhesion are further investigated for both a spatula-like nano-film and a hierarchical structure-like gecko's seta. Compared with the case without pre-tension, the pre-tension, no matter uniform or non-uniform, can increase the adhesion force not only for the spatula-like nano-film but also for the hierarchical structure at a small peeling angle, while decrease it at a relatively large peeling angle. Furthermore, if the pre-tension is large enough, the effective adhesion energy of a hierarchical structure tends to vanish at a critical peeling angle, which results in spontaneous detachment of the hierarchical structure from the substrate. The present theoretical predictions can not only give some explanations on the existing experimental observation that gecko's seta always detaches at a specific angle and no apparent adhesion force can be detected above the critical angle but also provide a deep understanding for the reversible adhesion mechanism of geckos and be helpful to the design of biomimetic reversible adhesives.

Self-assembled 3D-hierarchical structure Cu2ZnSnS4 photocathodes by tuning anion ratios in precursor solution

International Nuclear Information System (INIS)

Wen, Xin; Shao, Hansen; Fu, Gao; Zhou, Yong; Zou, Zhigang; Luo, Wenjun; Guan, Zhongjie

2016-01-01

Cu 2 ZnSnS 4 (CZTS) is one of the most promising light capture materials for solar cells or solar fuels. Construction of 3D hierarchical structure is very important for efficient optoelectronic devices. It is challenging to directly fabricate 3D hierarchical structure CZTS film by a facile solution method. Herein, we present a one-step sol–gel method for fabrication of CZTS thin films with 3D hierarchical structures. For the first time, it is found that the morphologies of thin films can be adjusted between dense, porous and 3D hierarchical structures by tuning anion ratios of Cl − /Ac − in precursor solution. Further analysis suggests the formation of intermediate phases of SnO 2 nanoparticles and SnS 2 nanosheets by tuning ratios of Cl − /Ac − in precursor solution, which has important effects on the formation of different nanostructures of CZTS. This study can deepen understanding of anion’ effect on morphologies of samples using a solution method and forms a reference to prepare novel nanostructures of other materials. (paper)

Structural building screening and evaluation

Science.gov (United States)

Kurniawandy, Alex; Nakazawa, Shoji; Hendry, Andy; Ridwan, Firdaus, Rahmatul

2017-10-01

An earthquake is a disaster that can be harmful to the community, such as financial loss and also dead injuries. Pekanbaru is a city that located in the middle of Sumatera Island. Even though the city of Pekanbaru is a city that rarely occurs earthquake, but Pekanbaru has ever felt the impact of the big earthquake that occurred in West Sumatera on September 2009. As we know, Indonesia located between Eurasia plate, Pacific plate, and Indo-Australian plate. Particularly the Sumatera Island, It has the Semangko fault or the great Sumatra fault along the island from north to south due to the shift of Eurasia and Indo-Australian Plates. An earthquake is not killing people but the building around the people that could be killing them. The failure of the building can be early prevented by doing an evaluation. In this research, the methods of evaluation have used a guideline for the Federal Emergency Management Agency (FEMA) P-154 and Applied Technology Council (ATC) 40. FEMA P-154 is a rapid visual screening of buildings for potential seismic hazards and ATC-40 is seismic evaluation and retrofit of Concrete Buildings. ATC-40 is a more complex evaluation rather than FEMA P-154. The samples to be evaluated are taken in the surroundings of Universitas Riau facility in Pekanbaru. There are four buildings as case study such as the rent student building, the building of mathematics and natural science faculty, the building teacher training and education faculty and the buildings in the faculty of Social political sciences. Vulnerability for every building facing an earthquake is different, this is depending on structural and non-structural components of the building. Among all of the samples, only the building of mathematics and the natural science faculty is in critical condition according to the FEMA P-154 evaluation. Furthermore, the results of evaluation using ATC-40 for the teacher training building are in damage control conditions, despite the other three buildings are

Assembly of CdS Quantum Dots onto Hierarchical TiO2 Structure for Quantum Dots Sensitized Solar Cell Applications

Directory of Open Access Journals (Sweden)

Syed Mansoor Ali

2015-05-01

Full Text Available Quantum dot (QD sensitized solar cells based on Hierarchical TiO2 structure (HTS consisting of spherical nano-urchins on transparent conductive fluorine doped tin oxide glass substrate is fabricated. The hierarchical TiO2 structure consisting of spherical nano-urchins on transparent conductive fluorine doped tin oxide glass substrate synthesized by hydrothermal route. The CdS quantum dots were grown by the successive ionic layer adsorption and reaction deposition method. The quantum dot sensitized solar cell based on the hierarchical TiO2 structure shows a current density JSC = 1.44 mA, VOC = 0.46 V, FF = 0.42 and η = 0.27%. The QD provide a high surface area and nano-urchins offer a highway for fast charge collection and multiple scattering centers within the photoelectrode.

Improved Adhesion and Compliancy of Hierarchical Fibrillar Adhesives.

Science.gov (United States)

Li, Yasong; Gates, Byron D; Menon, Carlo

2015-08-05

The gecko relies on van der Waals forces to cling onto surfaces with a variety of topography and composition. The hierarchical fibrillar structures on their climbing feet, ranging from mesoscale to nanoscale, are hypothesized to be key elements for the animal to conquer both smooth and rough surfaces. An epoxy-based artificial hierarchical fibrillar adhesive was prepared to study the influence of the hierarchical structures on the properties of a dry adhesive. The presented experiments highlight the advantages of a hierarchical structure despite a reduction of overall density and aspect ratio of nanofibrils. In contrast to an adhesive containing only nanometer-size fibrils, the hierarchical fibrillar adhesives exhibited a higher adhesion force and better compliancy when tested on an identical substrate.

Iterative model-building, structure refinement, and density modification with the PHENIX AutoBuild Wizard

Energy Technology Data Exchange (ETDEWEB)

Los Alamos National Laboratory, Mailstop M888, Los Alamos, NM 87545, USA; Lawrence Berkeley National Laboratory, One Cyclotron Road, Building 64R0121, Berkeley, CA 94720, USA; Department of Haematology, University of Cambridge, Cambridge CB2 0XY, England; Terwilliger, Thomas; Terwilliger, T.C.; Grosse-Kunstleve, Ralf Wilhelm; Afonine, P.V.; Moriarty, N.W.; Zwart, P.H.; Hung, L.-W.; Read, R.J.; Adams, P.D.

2007-04-29

The PHENIX AutoBuild Wizard is a highly automated tool for iterative model-building, structure refinement and density modification using RESOLVE or TEXTAL model-building, RESOLVE statistical density modification, and phenix.refine structure refinement. Recent advances in the AutoBuild Wizard and phenix.refine include automated detection and application of NCS from models as they are built, extensive model completion algorithms, and automated solvent molecule picking. Model completion algorithms in the AutoBuild Wizard include loop-building, crossovers between chains in different models of a structure, and side-chain optimization. The AutoBuild Wizard has been applied to a set of 48 structures at resolutions ranging from 1.1 {angstrom} to 3.2 {angstrom}, resulting in a mean R-factor of 0.24 and a mean free R factor of 0.29. The R-factor of the final model is dependent on the quality of the starting electron density, and relatively independent of resolution.

Iterative model building, structure refinement and density modification with the PHENIX AutoBuild wizard

International Nuclear Information System (INIS)

Terwilliger, Thomas C.; Grosse-Kunstleve, Ralf W.; Afonine, Pavel V.; Moriarty, Nigel W.; Zwart, Peter H.; Hung, Li-Wei; Read, Randy J.; Adams, Paul D.

2008-01-01

The highly automated PHENIX AutoBuild wizard is described. The procedure can be applied equally well to phases derived from isomorphous/anomalous and molecular-replacement methods. The PHENIX AutoBuild wizard is a highly automated tool for iterative model building, structure refinement and density modification using RESOLVE model building, RESOLVE statistical density modification and phenix.refine structure refinement. Recent advances in the AutoBuild wizard and phenix.refine include automated detection and application of NCS from models as they are built, extensive model-completion algorithms and automated solvent-molecule picking. Model-completion algorithms in the AutoBuild wizard include loop building, crossovers between chains in different models of a structure and side-chain optimization. The AutoBuild wizard has been applied to a set of 48 structures at resolutions ranging from 1.1 to 3.2 Å, resulting in a mean R factor of 0.24 and a mean free R factor of 0.29. The R factor of the final model is dependent on the quality of the starting electron density and is relatively independent of resolution

STRUCTURAL VULNERABILITY ASSESSMENT OF MASONRY BUILDINGS IN TURKEY

OpenAIRE

KORKMAZ, Kasım Armagan; CARHOGLU, Asuman Isıl

2011-01-01

Turkey is located in an active seismic zone. Mid to high rise R/C building and low rise masonry buildings are very common construction type in Turkey. In recent earthquakes, lots of existing buildings got damage including masonry buildings. Masonry building history in Turkey goes long years back. For sure, it is an important structure type for Turkey. Therefore, earthquake behavior and structural vulnerability of masonry buildings are crucial issues for Turkey as a earthquake prone country. I...

Earthquake risk assessment of building structures

International Nuclear Information System (INIS)

Ellingwood, Bruce R.

2001-01-01

During the past two decades, probabilistic risk analysis tools have been applied to assess the performance of new and existing building structural systems. Structural design and evaluation of buildings and other facilities with regard to their ability to withstand the effects of earthquakes requires special considerations that are not normally a part of such evaluations for other occupancy, service and environmental loads. This paper reviews some of these special considerations, specifically as they pertain to probability-based codified design and reliability-based condition assessment of existing buildings. Difficulties experienced in implementing probability-based limit states design criteria for earthquake are summarized. Comparisons of predicted and observed building damage highlight the limitations of using current deterministic approaches for post-earthquake building condition assessment. The importance of inherent randomness and modeling uncertainty in forecasting building performance is examined through a building fragility assessment of a steel frame with welded connections that was damaged during the Northridge Earthquake of 1994. The prospects for future improvements in earthquake-resistant design procedures based on a more rational probability-based treatment of uncertainty are examined

Hierarchical organization versus self-organization

OpenAIRE

Busseniers, Evo

2014-01-01

In this paper we try to define the difference between hierarchical organization and self-organization. Organization is defined as a structure with a function. So we can define the difference between hierarchical organization and self-organization both on the structure as on the function. In the next two chapters these two definitions are given. For the structure we will use some existing definitions in graph theory, for the function we will use existing theory on (self-)organization. In the t...

HD-RNAS: An automated hierarchical database of RNA structures

Directory of Open Access Journals (Sweden)

Shubhra Sankar eRay

2012-04-01

Full Text Available One of the important goals of most biological investigations is to classify and organize the experimental findings so that they are readily useful for deriving generalized rules. Although there is a huge amount of information on RNA structures in PDB, there are redundant files, ambiguous synthetic sequences etc. Moreover, a systematic hierarchical organization, reflecting RNA classification, is missing in PDB. In this investigation, we have classified all the available RNA crystal structures from PDB through a programmatic approach. Hence, it would be now a simple assignment to regularly update the classification as and when new structures are released. The classification can further determine (i a non-redundant set of RNA structures and (ii if available, a set of structures of identical sequence and function, which can highlight structural polymorphism, ligand-induced conformational alterations etc. Presently, we have classified the available structures (2095 PDB entries having RNA chain longer than 9 nucleotides solved by X-ray crystallography or NMR spectroscopy into nine functional classes. The structures of same function and same source are mostly seen to be similar with subtle differences depending on their functional complexation. The web-server is available online at http://www.saha.ac.in/biop/www/HD-RNAS.html and is updated regularly.

Hydrothermal deposition and photochromic performances of three kinds of hierarchical structure arrays of WO3 thin films

International Nuclear Information System (INIS)

Ding, Defang; Shen, Yi; Ouyang, Yali; Li, Zhen

2012-01-01

Three kinds of tungsten oxide (WO 3 ) thin films have been fabricated by a simple hydrothermal deposition method. Scanning electron microscopy images of the products revealed that the capping agents did impact the microstructure of WO 3 films. Films prepared without capping agents were ordered nanorod arrays, while the ones obtained with ethanol and oxalic acid revealed peeled-orange-like and cauliflower-like hierarchical structure arrays, respectively. Both of the two hierarchical structures were composed of much thinner nanorods compared with the one obtained without capping agents. All the WO 3 films exhibited good photochromic properties and the two with inducers performed even better, which could be due to the changes in the microstructure that increased the amount of photogenerated electron–hole pairs and the proton diffusion rates. - Highlights: ► Ordered WO 3 nanorod arrays were prepared by hydrothermal deposition process. ► Two hierarchical WO 3 structure arrays were obtained with ethanol and oxalic acid. ► Mechanism for the improved photochromic performances of WO 3 films is proposed.

Hierarchical Sets: Analyzing Pangenome Structure through Scalable Set Visualizations

DEFF Research Database (Denmark)

Pedersen, Thomas Lin

2017-01-01

of hierarchical sets by applying it to a pangenome based on 113 Escherichia and Shigella genomes and find it provides a powerful addition to pangenome analysis. The described clustering algorithm and visualizations are implemented in the hierarchicalSets R package available from CRAN (https...

Intelligent seismic risk mitigation system on structure building

Science.gov (United States)

Suryanita, R.; Maizir, H.; Yuniorto, E.; Jingga, H.

2018-01-01

Indonesia located on the Pacific Ring of Fire, is one of the highest-risk seismic zone in the world. The strong ground motion might cause catastrophic collapse of the building which leads to casualties and property damages. Therefore, it is imperative to properly design the structural response of building against seismic hazard. Seismic-resistant building design process requires structural analysis to be performed to obtain the necessary building responses. However, the structural analysis could be very difficult and time consuming. This study aims to predict the structural response includes displacement, velocity, and acceleration of multi-storey building with the fixed floor plan using Artificial Neural Network (ANN) method based on the 2010 Indonesian seismic hazard map. By varying the building height, soil condition, and seismic location in 47 cities in Indonesia, 6345 data sets were obtained and fed into the ANN model for the learning process. The trained ANN can predict the displacement, velocity, and acceleration responses with up to 96% of predicted rate. The trained ANN architecture and weight factors were later used to build a simple tool in Visual Basic program which possesses the features for prediction of structural response as mentioned previously.

Self-assembly of NiO/graphene with three-dimension hierarchical structure as high performance electrode material for supercapacitors

Energy Technology Data Exchange (ETDEWEB)

Zhao, Bing; Zhuang, Hua; Fang, Tao; Jiao, Zheng; Liu, Ruizhe; Ling, Xuetao [School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444 (China); Lu, Bo [Instrumental Analysis and Research Center, Shanghai University, Shanghai 200444 (China); Jiang, Yong, E-mail: jiangyong@shu.edu.cn [School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444 (China)

2014-06-01

Highlights: • 3D hierarchical NiO/graphene is prepared by a refluxing method with aqua-based solvent. • Time-dependent experiments are carried out to investigate formation mechanism. • Hierarchical sphere is formed through self-assembly of NiO grown on disc-shaped CTAB micelles. • It delivers a capacitance of 555 F g{sup −1} at 1 A g{sup −1} with 90.8% retention after 2000 cycles. - Abstract: This article reports a facile preparation of NiO/graphene composite by the combination of a controlled refluxing method with water based solvent in the presence of cetyltrimethylammonium bromide and subsequent annealing. X-ray diffraction and scanning electron microscopy reveal that the graphene nanosheets are uniformly wrapped by hierarchical porous NiO spheres with three-dimension hierarchical structure in the product. The composite shows highly improved electrochemical performance as electrode material for supercapacitor. The three-dimension hierarchical structure NiO/graphene composite delivers a first discharge capacitance of 555 F g{sup −1} and remains a reversible capacitance up to 504 F g{sup −1} after 2000 cycles at a current of 1 A g{sup −1} in three-electrode system. Contrarily, the pure NiO shows only a first discharge capacitance of 166 F g{sup −1} and remains only a reversible capacitance of 107 F g{sup −1} after 2000 cycles. The NiO/graphene composite also exhibits ameliorative rate capacitance of 402.9 F g{sup −1} at the current density of 5 A g{sup −1}. The enhanced electrochemical performances are ascribed to the higher surface area, the stable three-dimension hierarchical structure and the synergistic effects between the conductive graphene and porous NiO spheres.

Correlation between hierarchical structure of crystal networks and macroscopic performance of mesoscopic soft materials and engineering principles.

Science.gov (United States)

Lin, Naibo; Liu, Xiang Yang

2015-11-07

This review examines how the concepts and ideas of crystallization can be extended further and applied to the field of mesoscopic soft materials. It concerns the structural characteristics vs. the macroscopic performance, and the formation mechanism of crystal networks. Although this subject can be discussed in a broad sense across the area of mesoscopic soft materials, our main focus is on supramolecular materials, spider and silkworm silks, and biominerals. First, the occurrence of a hierarchical structure, i.e. crystal network and domain network structures, will facilitate the formation kinetics of mesoscopic phases and boost up the macroscopic performance of materials in some cases (i.e. spider silk fibres). Second, the structure and performance of materials can be correlated in some way by the four factors: topology, correlation length, symmetry/ordering, and strength of association of crystal networks. Moreover, four different kinetic paths of crystal network formation are identified, namely, one-step process of assembly, two-step process of assembly, mixed mode of assembly and foreign molecule mediated assembly. Based on the basic mechanisms of crystal nucleation and growth, the formation of crystal networks, such as crystallographic mismatch (or noncrystallographic) branching (tip branching and fibre side branching) and fibre/polymeric side merging, are reviewed. This facilitates the rational design and construction of crystal networks in supramolecular materials. In this context, the (re-)construction of a hierarchical crystal network structure can be implemented by thermal, precipitate, chemical, and sonication stimuli. As another important class of soft materials, the unusual mechanical performance of spider and silkworm silk fibres are reviewed in comparison with the regenerated silk protein derivatives. It follows that the considerably larger breaking stress and unusual breaking strain of spider silk fibres vs. silkworm silk fibres can be interpreted

The role of supramolecular chemistry in stimuli responsive and hierarchically structured functional organic materials

NARCIS (Netherlands)

Schenning, A.P.H.J.; Bastiaansen, C.W.M.; Broer, D.J.; Debije, M.G.

2014-01-01

ABSTRACT: In this review, we show the important role of supramolecular chemistry in the fabrication of stimuli responsive and hierarchically structured liquid crystalline polymer networks. Supramolecular interactions can be used to create three dimensional order or as molecular triggers in materials

Personality in chimpanzees (Pan troglodytes: exploring the hierarchical structure and associations with the vasopressin V1A receptor gene.

Directory of Open Access Journals (Sweden)

Robert D Latzman

Full Text Available One of the major contributions of recent personality psychology is the finding that traits are related to each other in an organized hierarchy. To date, however, researchers have yet to investigate this hierarchy in nonhuman primates. Such investigations are critical in confirming the cross-species nature of trait personality helping to illuminate personality as neurobiologically-based and evolutionarily-derived dimensions of primate disposition. Investigations of potential genetic polymorphisms associated with hierarchical models of personality among nonhuman primates represent a critical first step. The current study examined the hierarchical structure of chimpanzee personality as well as sex-specific associations with a polymorphism in the promoter region of the vasopressin V1a receptor gene (AVPR1A, a gene associated with dispositional traits, among 174 chimpanzees. Results confirmed a hierarchical structure of personality across species and, despite differences in early rearing experiences, suggest a sexually dimorphic role of AVPR1A polymorphisms on hierarchical personality profiles at a higher-order level.

Personality in Chimpanzees (Pan troglodytes): Exploring the Hierarchical Structure and Associations with the Vasopressin V1A Receptor Gene

Science.gov (United States)

Latzman, Robert D.; Hopkins, William D.; Keebaugh, Alaine C.; Young, Larry J.

2014-01-01

One of the major contributions of recent personality psychology is the finding that traits are related to each other in an organized hierarchy. To date, however, researchers have yet to investigate this hierarchy in nonhuman primates. Such investigations are critical in confirming the cross-species nature of trait personality helping to illuminate personality as neurobiologically-based and evolutionarily-derived dimensions of primate disposition. Investigations of potential genetic polymorphisms associated with hierarchical models of personality among nonhuman primates represent a critical first step. The current study examined the hierarchical structure of chimpanzee personality as well as sex-specific associations with a polymorphism in the promoter region of the vasopressin V1a receptor gene (AVPR1A), a gene associated with dispositional traits, among 174 chimpanzees. Results confirmed a hierarchical structure of personality across species and, despite differences in early rearing experiences, suggest a sexually dimorphic role of AVPR1A polymorphisms on hierarchical personality profiles at a higher-order level. PMID:24752497

Kendall’s tau and agglomerative clustering for structure determination of hierarchical Archimedean copulas

Directory of Open Access Journals (Sweden)

Górecki J.

2017-01-01

Full Text Available Several successful approaches to structure determination of hierarchical Archimedean copulas (HACs proposed in the literature rely on agglomerative clustering and Kendall’s correlation coefficient. However, there has not been presented any theoretical proof justifying such approaches. This work fills this gap and introduces a theorem showing that, given the matrix of the pairwise Kendall correlation coefficients corresponding to a HAC, its structure can be recovered by an agglomerative clustering technique.

Classification of Hyperspectral Images by SVM Using a Composite Kernel by Employing Spectral, Spatial and Hierarchical Structure Information

Directory of Open Access Journals (Sweden)

Yi Wang

2018-03-01

Full Text Available In this paper, we introduce a novel classification framework for hyperspectral images (HSIs by jointly employing spectral, spatial, and hierarchical structure information. In this framework, the three types of information are integrated into the SVM classifier in a way of multiple kernels. Specifically, the spectral kernel is constructed through each pixel’s vector value in the original HSI, and the spatial kernel is modeled by using the extended morphological profile method due to its simplicity and effectiveness. To accurately characterize hierarchical structure features, the techniques of Fish-Markov selector (FMS, marker-based hierarchical segmentation (MHSEG and algebraic multigrid (AMG are combined. First, the FMS algorithm is used on the original HSI for feature selection to produce its spectral subset. Then, the multigrid structure of this subset is constructed using the AMG method. Subsequently, the MHSEG algorithm is exploited to obtain a hierarchy consist of a series of segmentation maps. Finally, the hierarchical structure information is represented by using these segmentation maps. The main contributions of this work is to present an effective composite kernel for HSI classification by utilizing spatial structure information in multiple scales. Experiments were conducted on two hyperspectral remote sensing images to validate that the proposed framework can achieve better classification results than several popular kernel-based classification methods in terms of both qualitative and quantitative analysis. Specifically, the proposed classification framework can achieve 13.46–15.61% in average higher than the standard SVM classifier under different training sets in the terms of overall accuracy.

Measurement methods of building structures deflections

Directory of Open Access Journals (Sweden)

Wróblewska Magdalena

2018-01-01

Full Text Available Underground mining exploitation is leading to the occurrence of deformations manifested by, in particular, sloping terrain. The structures situated on the deforming subsoil are subject to uneven subsidence which is leading in consequence to their deflection. Before a building rectification process takes place by, e.g. uneven raising, the structure's deflection direction and value is determined so that the structure is restored to its vertical position as a result of the undertaken remedial measures. Deflection can be determined by applying classical as well as modern measurement techniques. The article presents examples of measurement methods used considering the measured elements of building structures’ constructions and field measurements. Moreover, for a given example of a mining area, the existing deflections of buildings were compared with mining terrain sloping.

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.

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

KAUST Repository

Yu, H.; Qiu, Xiaoyan; Behzad, Ali Reza; Musteata, Valentina-Elena; Smilgies, D.-M.; Nunes, Suzana Pereira; Peinemann, Klaus-Viktor

2016-01-01

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.

A study of hierarchical structure on South China industrial electricity-consumption correlation

Science.gov (United States)

Yao, Can-Zhong; Lin, Ji-Nan; Liu, Xiao-Feng

2016-02-01

Based on industrial electricity-consumption data of five southern provinces of China from 2005 to 2013, we study the industrial correlation mechanism with MST (minimal spanning tree) and HT (hierarchical tree) models. First, we comparatively analyze the industrial electricity-consumption correlation structure in pre-crisis and after-crisis period using MST model and Bootstrap technique of statistical reliability test of links. Results exhibit that all industrial electricity-consumption trees of five southern provinces of China in pre-crisis and after-crisis time are in formation of chain, and the "center-periphery structure" of those chain-like trees is consistent with industrial specialization in classical industrial chain theory. Additionally, the industrial structure of some provinces is reorganized and transferred in pre-crisis and after-crisis time. Further, the comparative analysis with hierarchical tree and Bootstrap technique demonstrates that as for both observations of GD and overall NF, the industrial electricity-consumption correlation is non-significant clustered in pre-crisis period, whereas it turns significant clustered in after-crisis time. Therefore we propose that in perspective of electricity-consumption, their industrial structures are directed to optimized organization and global correlation. Finally, the analysis of distance of HTs verifies that industrial reorganization and development may strengthen market integration, coordination and correlation of industrial production. Except GZ, other four provinces have a shorter distance of industrial electricity-consumption correlation in after-crisis period, revealing a better performance of regional specialization and integration.

Microscale and nanoscale hierarchical structured mesh films with superhydrophobic and superoleophilic properties induced by long-chain fatty acids

International Nuclear Information System (INIS)

Wang Shutao; Song Yanlin; Jiang Lei

2007-01-01

Inspired by the lotus effect, we fabricate new microscale and nanoscale hierarchical structured copper mesh films by a simple electrochemical deposition. After modification of the long-chain fatty acid monolayer, these films show superhydrophobic and superoleophilic properties, which could be used for the effective separation of oil and water. The length of the fatty acid chain strongly influences the surface wettability of as-prepared films. It is confirmed that the cooperative effect of the hierarchical structure of the copper film and the nature of the long-chain fatty acid contribute to this unique surface wettability

Morphologies and wetting properties of copper film with 3D porous micro-nano hierarchical structure prepared by electrochemical deposition

International Nuclear Information System (INIS)

Wang, Hongbin; Wang, Ning; Hang, Tao; Li, Ming

2016-01-01

Highlights: • A 3D porous micro-nano hierarchical structure Cu films were prepared. • The evolution of morphology and wettability with deposition time was reported. • The effects of EDA on the microscopic morphology were revealed. • A high contact angle of 162.1° was measured when deposition time is 5 s. • The mechanism of super-hydrophobicity was illustrated by two classical models. - Abstract: Three-dimensional porous micro-nano hierarchical structure Cu films were prepared by electrochemical deposition with the Hydrogen bubble dynamic template. The morphologies of the deposited films characterized by Scanning Electronic Microscopy (SEM) exhibit a porous micro-nano hierarchical structure, which consists of three levels in different size scales, namely the honeycomb-like microstructure, the dendritic substructure and the nano particles. Besides, the factors which influenced the microscopic morphology were studied, including the deposition time and the additive Ethylene diamine. By measuring the water contact angle, the porous copper films were found to be super-hydrophobic. The maximum of the contact angles could reach as high as 162.1°. An empirical correlation between morphologies and wetting properties was revealed for the first time. The pore diameter increased simultaneously with the deposition time while the contact angle decreased. The mechanism was illustrated by two classical models. Such super-hydrophobic three-dimensional hierarchical micro-nano structure is expected to have practical application in industry.

Exploring hierarchical and overlapping modular structure in the yeast protein interaction network

Directory of Open Access Journals (Sweden)

Zhao Yi

2010-12-01

Full Text Available Abstract Background Developing effective strategies to reveal modular structures in protein interaction networks is crucial for better understanding of molecular mechanisms of underlying biological processes. In this paper, we propose a new density-based algorithm (ADHOC for clustering vertices of a protein interaction network using a novel subgraph density measurement. Results By statistically evaluating several independent criteria, we found that ADHOC could significantly improve the outcome as compared with five previously reported density-dependent methods. We further applied ADHOC to investigate the hierarchical and overlapping modular structure in the yeast PPI network. Our method could effectively detect both protein modules and the overlaps between them, and thus greatly promote the precise prediction of protein functions. Moreover, by further assaying the intermodule layer of the yeast PPI network, we classified hubs into two types, module hubs and inter-module hubs. Each type presents distinct characteristics both in network topology and biological functions, which could conduce to the better understanding of relationship between network architecture and biological implications. Conclusions Our proposed algorithm based on the novel subgraph density measurement makes it possible to more precisely detect hierarchical and overlapping modular structures in protein interaction networks. In addition, our method also shows a strong robustness against the noise in network, which is quite critical for analyzing such a high noise network.

Experimental building with new types of building envelope structures. Part 1: Structures/systems. Building system: Brick walls; Forsoegshus med nye typer klimaskaermskonstruktioner. Del 1: Konstruktioner/systemer - Byggesystem: Fuldmuret

Energy Technology Data Exchange (ETDEWEB)

NONE

2003-07-01

The house described in this report is one of several experimental houses forming part of the project 'Experimental buildings with new types of building envelope structures'. One purpose of the project is to demonstrate that it is possible to build typical single-family houses with an energy consumption that meets expected increased building regulations. Furthermore, it is important that the houses can be made securely as regards construction technology and within reasonable financial limits. Thus, the purpose is also to contribute to strengthen the development of improved building envelope structures. Another purpose is to carry out detailed measurements of energy consumption in order to validate thermal performance of future building envelope structures. The report describes the constructive design and energy systems of the house plus heat loss calculations and expected energy consumption. (BA)

Quantum Ising model on hierarchical structures

International Nuclear Information System (INIS)

Lin Zhifang; Tao Ruibao.

1989-11-01

A quantum Ising chain with both the exchange couplings and the transverse fields arranged in a hierarchical way is considered. Exact analytical results for the critical line and energy gap are obtained. It is shown that when R 1 not= R 2 , where R 1 and R 2 are the hierarchical parameters for the exchange couplings and the transverse fields, respectively, the system undergoes a phase transition in a different universality class from the pure quantum Ising chain with R 1 =R 2 =1. On the other hand, when R 1 =R 2 =R, there exists a critical value R c dependent on the furcating number of the hierarchy. In case of R > R c , the system is shown to exhibit as Ising-like critical point with the critical behaviour the same as in the pure case, while for R c the system belongs to another universality class. (author). 19 refs, 2 figs

Hydrothermal deposition and photochromic performances of three kinds of hierarchical structure arrays of WO{sub 3} thin films

Energy Technology Data Exchange (ETDEWEB)

Ding, Defang; Shen, Yi, E-mail: sysy7373@163.com; Ouyang, Yali; Li, Zhen

2012-10-01

Three kinds of tungsten oxide (WO{sub 3}) thin films have been fabricated by a simple hydrothermal deposition method. Scanning electron microscopy images of the products revealed that the capping agents did impact the microstructure of WO{sub 3} films. Films prepared without capping agents were ordered nanorod arrays, while the ones obtained with ethanol and oxalic acid revealed peeled-orange-like and cauliflower-like hierarchical structure arrays, respectively. Both of the two hierarchical structures were composed of much thinner nanorods compared with the one obtained without capping agents. All the WO{sub 3} films exhibited good photochromic properties and the two with inducers performed even better, which could be due to the changes in the microstructure that increased the amount of photogenerated electron-hole pairs and the proton diffusion rates. - Highlights: Black-Right-Pointing-Pointer Ordered WO{sub 3} nanorod arrays were prepared by hydrothermal deposition process. Black-Right-Pointing-Pointer Two hierarchical WO{sub 3} structure arrays were obtained with ethanol and oxalic acid. Black-Right-Pointing-Pointer Mechanism for the improved photochromic performances of WO{sub 3} films is proposed.

Environmental effect of structural solutions and building materials to a building

International Nuclear Information System (INIS)

Haapio, Appu; Viitaniemi, Pertti

2008-01-01

The field of building environmental assessment tools has become a popular research area over the past decade. However, how the service life of a building affects the results of the environmental assessment of a building has not been emphasised previously. The aim of this study is to analyse how different structural solutions and building materials affect the results of the environmental assessment of a whole building over the building's life cycle. Furthermore, how the length of the building's service life affects the results is analysed. The environmental assessments of 78 single-family houses were calculated for this study. The buildings have different wall insulations, claddings, window frames, and roof materials, and the length of the service life varies from 60 years up to 160 years. The current situation and the future of the environmental assessment of buildings are discussed. In addition, topics for further research are suggested; for example, how workmanship affects the service life and the environmental impact of a building should be studied

Complexity of major UK companies between 2006 and 2010: Hierarchical structure method approach

Science.gov (United States)

Ulusoy, Tolga; Keskin, Mustafa; Shirvani, Ayoub; Deviren, Bayram; Kantar, Ersin; Çaǧrı Dönmez, Cem

2012-11-01

This study reports on topology of the top 40 UK companies that have been analysed for predictive verification of markets for the period 2006-2010, applying the concept of minimal spanning tree and hierarchical tree (HT) analysis. Construction of the minimal spanning tree (MST) and the hierarchical tree (HT) is confined to a brief description of the methodology and a definition of the correlation function between a pair of companies based on the London Stock Exchange (LSE) index in order to quantify synchronization between the companies. A derivation of hierarchical organization and the construction of minimal-spanning and hierarchical trees for the 2006-2008 and 2008-2010 periods have been used and the results validate the predictive verification of applied semantics. The trees are known as useful tools to perceive and detect the global structure, taxonomy and hierarchy in financial data. From these trees, two different clusters of companies in 2006 were detected. They also show three clusters in 2008 and two between 2008 and 2010, according to their proximity. The clusters match each other as regards their common production activities or their strong interrelationship. The key companies are generally given by major economic activities as expected. This work gives a comparative approach between MST and HT methods from statistical physics and information theory with analysis of financial markets that may give new valuable and useful information of the financial market dynamics.

Structural rehabilitation of old buildings

CERN Document Server

Guedes, João; Varum, Humberto

2014-01-01

The present book describes the different construction systems and structural materials and solutions within the main old buildings typologies, and it analyses the particularities of each of them, including mechanical properties, structural behaviour, typical damage patterns and collapse mechanisms. Common or pioneering intervention measures to repair and/or strengthen some of these structural elements are also reviewed.

Hierarchically structured MnO2 nanowires supported on hollow Ni dendrites for high-performance supercapacitors

Science.gov (United States)

Sun, Zhipeng; Firdoz, Shaik; Ying-Xuan Yap, Esther; Li, Lan; Lu, Xianmao

2013-05-01

We report a hierarchical Ni@MnO2 structure consisting of MnO2 nanowires supported on hollow Ni dendrites for high-performance supercapacitors. The Ni@MnO2 structure, which was prepared via a facile electrodeposition method, is highly porous and appears like a forest of pine trees grown vertically on a substrate. At a MnO2 mass loading of 0.35 mg cm-2, the Ni@MnO2 electrode demonstrated a specific capacitance of 1125 F g-1 that is close to the theoretical value. In addition, a remarkable high-rate performance (766 F g-1 at a discharge current density of 100 A g-1) was achieved. Electrochemical tests in a two-electrode configuration for the Ni@MnO2 structure with a high MnO2 loading of 3.6 mg cm-2 showed a low equivalent series resistance (ESR) of 1 Ω and a high specific power of 72 kW kg-1. This superior performance can be attributed to the highly porous and hierarchical structure of Ni@MnO2 that favors rapid diffusion of an electrolyte, highly conductive pathway for electron transport, and efficient material utilization.We report a hierarchical Ni@MnO2 structure consisting of MnO2 nanowires supported on hollow Ni dendrites for high-performance supercapacitors. The Ni@MnO2 structure, which was prepared via a facile electrodeposition method, is highly porous and appears like a forest of pine trees grown vertically on a substrate. At a MnO2 mass loading of 0.35 mg cm-2, the Ni@MnO2 electrode demonstrated a specific capacitance of 1125 F g-1 that is close to the theoretical value. In addition, a remarkable high-rate performance (766 F g-1 at a discharge current density of 100 A g-1) was achieved. Electrochemical tests in a two-electrode configuration for the Ni@MnO2 structure with a high MnO2 loading of 3.6 mg cm-2 showed a low equivalent series resistance (ESR) of 1 Ω and a high specific power of 72 kW kg-1. This superior performance can be attributed to the highly porous and hierarchical structure of Ni@MnO2 that favors rapid diffusion of an electrolyte, highly

Statistical Significance for Hierarchical Clustering

Science.gov (United States)

Kimes, Patrick K.; Liu, Yufeng; Hayes, D. Neil; Marron, J. S.

2017-01-01

Summary Cluster analysis has proved to be an invaluable tool for the exploratory and unsupervised analysis of high dimensional datasets. Among methods for clustering, hierarchical approaches have enjoyed substantial popularity in genomics and other fields for their ability to simultaneously uncover multiple layers of clustering structure. A critical and challenging question in cluster analysis is whether the identified clusters represent important underlying structure or are artifacts of natural sampling variation. Few approaches have been proposed for addressing this problem in the context of hierarchical clustering, for which the problem is further complicated by the natural tree structure of the partition, and the multiplicity of tests required to parse the layers of nested clusters. In this paper, we propose a Monte Carlo based approach for testing statistical significance in hierarchical clustering which addresses these issues. The approach is implemented as a sequential testing procedure guaranteeing control of the family-wise error rate. Theoretical justification is provided for our approach, and its power to detect true clustering structure is illustrated through several simulation studies and applications to two cancer gene expression datasets. PMID:28099990

Hierarchical decision making for flood risk reduction

DEFF Research Database (Denmark)

Custer, Rocco; Nishijima, Kazuyoshi

2013-01-01

. In current practice, structures are often optimized individually without considering benefits of having a hierarchy of protection structures. It is here argued, that the joint consideration of hierarchically integrated protection structures is beneficial. A hierarchical decision model is utilized to analyze...... and compare the benefit of large upstream protection structures and local downstream protection structures in regard to epistemic uncertainty parameters. Results suggest that epistemic uncertainty influences the outcome of the decision model and that, depending on the magnitude of epistemic uncertainty...

Fabrication of hydrophobic surface with hierarchical structure on Mg alloy and its corrosion resistance

International Nuclear Information System (INIS)

Wang Jun; Li Dandan; Liu Qi; Yin Xi; Zhang Ying; Jing Xiaoyan; Zhang Milin

2010-01-01

A hydrotalcite/hydromagnesite conversion coating with hierarchical structure has been fabricated on a Mg alloy substrate by in situ hydrothermal crystallization method. A MgO layer existing between the hydrotalcite/hydromagnesite film and the substrate was formed prior to the hydrotalcite/hydromagnesite film during the crystallization process. After surface treatment with silane coupling agent, the surface of conversion coating changes from hydrophilic to hydrophobic. Scanning electron microscopy (SEM) revealed that the silylated conversion coating with hierarchical structure maintains the original rough surface of which was composed of numerous micro-scale flakes and beautiful flower-like protrusions. Polarization measurements have shown that the hydrophobic conversion coating exhibited a low corrosion current density value of 0.432 μA/cm 2 , which means that the hydrophobic conversion coating can effectively protect Mg alloy from corrosion. Electrochemical impedance spectroscopy (EIS) showed that the impedance of the hydrophobic conversion coating was 9000 Ω. It means that the coating served as a passive layer with high charge transfer resistance.

Hierarchical phase space structure of dark matter haloes: Tidal debris, caustics, and dark matter annihilation

International Nuclear Information System (INIS)

Afshordi, Niayesh; Mohayaee, Roya; Bertschinger, Edmund

2009-01-01

Most of the mass content of dark matter haloes is expected to be in the form of tidal debris. The density of debris is not constant, but rather can grow due to formation of caustics at the apocenters and pericenters of the orbit, or decay as a result of phase mixing. In the phase space, the debris assemble in a hierarchy that is truncated by the primordial temperature of dark matter. Understanding this phase structure can be of significant importance for the interpretation of many astrophysical observations and, in particular, dark matter detection experiments. With this purpose in mind, we develop a general theoretical framework to describe the hierarchical structure of the phase space of cold dark matter haloes. We do not make any assumption of spherical symmetry and/or smooth and continuous accretion. Instead, working with correlation functions in the action-angle space, we can fully account for the hierarchical structure (predicting a two-point correlation function ∝ΔJ -1.6 in the action space), as well as the primordial discreteness of the phase space. As an application, we estimate the boost to the dark matter annihilation signal due to the structure of the phase space within virial radius: the boost due to the hierarchical tidal debris is of order unity, whereas the primordial discreteness of the phase structure can boost the total annihilation signal by up to an order of magnitude. The latter is dominated by the regions beyond 20% of the virial radius, and is largest for the recently formed haloes with the least degree of phase mixing. Nevertheless, as we argue in a companion paper, the boost due to small gravitationally-bound substructure can dominate this effect at low redshifts.

Hierarchical phase space structure of dark matter haloes: Tidal debris, caustics, and dark matter annihilation

Science.gov (United States)

Afshordi, Niayesh; Mohayaee, Roya; Bertschinger, Edmund

2009-04-01

Most of the mass content of dark matter haloes is expected to be in the form of tidal debris. The density of debris is not constant, but rather can grow due to formation of caustics at the apocenters and pericenters of the orbit, or decay as a result of phase mixing. In the phase space, the debris assemble in a hierarchy that is truncated by the primordial temperature of dark matter. Understanding this phase structure can be of significant importance for the interpretation of many astrophysical observations and, in particular, dark matter detection experiments. With this purpose in mind, we develop a general theoretical framework to describe the hierarchical structure of the phase space of cold dark matter haloes. We do not make any assumption of spherical symmetry and/or smooth and continuous accretion. Instead, working with correlation functions in the action-angle space, we can fully account for the hierarchical structure (predicting a two-point correlation function ∝ΔJ-1.6 in the action space), as well as the primordial discreteness of the phase space. As an application, we estimate the boost to the dark matter annihilation signal due to the structure of the phase space within virial radius: the boost due to the hierarchical tidal debris is of order unity, whereas the primordial discreteness of the phase structure can boost the total annihilation signal by up to an order of magnitude. The latter is dominated by the regions beyond 20% of the virial radius, and is largest for the recently formed haloes with the least degree of phase mixing. Nevertheless, as we argue in a companion paper, the boost due to small gravitationally-bound substructure can dominate this effect at low redshifts.

Interference mitigation for broadcast in hierarchical cell structure networks: Transmission strategy and area spectral efficiency

KAUST Repository

Yang, Yuli; Salama, Khaled N.; Aï ssa, Sonia

2014-01-01

In this paper, a hierarchical cell structure (HCS) is considered, where an access point (AP) broadcasts to local nodes (LNs) over orthogonal frequency subbands within a local cell located in a macrocell. Since the local cell shares the spectrum

Hierarchical silica particles by dynamic multicomponent assembly

DEFF Research Database (Denmark)

Wu, Z. W.; Hu, Q. Y.; Pang, J. B.

2005-01-01

Abstract: Aerosol-assisted assembly of mesoporous silica particles with hierarchically controllable pore structure has been prepared using cetyltrimethylammonium bromide (CTAB) and poly(propylene oxide) (PPO, H[OCH(CH3)CH2],OH) as co-templates. Addition of the hydrophobic PPO significantly...... influences the delicate hydrophilic-hydrophobic balance in the well-studied CTAB-silicate co-assembling system, resulting in various mesostructures (such as hexagonal, lamellar, and hierarchical structure). The co-assembly of CTAB, silicate clusters, and a low-molecular-weight PPO (average M-n 425) results...... in a uniform lamellar structure, while the use of a high-molecular-weight PPO (average M-n 2000), which is more hydrophobic, leads to the formation of hierarchical pore structure that contains meso-meso or meso-macro pore structure. The role of PPO additives on the mesostructure evolution in the CTAB...

About Hierarchical XML Structures, Replacement of Relational Data Structures in Construction and Implementation of ERP Systems

Directory of Open Access Journals (Sweden)

2007-01-01

Full Text Available The projects essential objective is to develop a new ERP system, of homogeneous nature, based on XML structures, as a possible replacement for classic ERP systems. The criteria that guide the objective definition are modularity, portability and Web connectivity. This objective is connected to a series of secondary objectives, considering that the technological approach will be filtered through the economic, social and legislative environment for a validation-by-context study. Statistics and cybernetics are to be used for simulation purposes. The homogeneous approach is meant to provide strong modularity and portability, in relation with the n-tier principles, but the main advantage of the model is its opening to the semantic Web, based on a Small enterprise ontology defined with XML-driven languages. Shockwave solutions will be used for implementing client-oriented hypermedia elements and an XML Gate will be de-fined between black box modules, for a clear separation with obvious advantages. Security and the XMLTP project will be an important issue for XML transfers due to the conflict between the open architecture of the Web, the readability of XML data and the privacy elements which have to be preserved within a business environment. The projects finality is oriented on small business but the semantic Web perspective and the surprising new conflict between hierarchical/network data structures and relational ones will certainly widen its scope. The proposed model is meant to fulfill the IT compatibility requirements of the European environment, defined as a knowledge society. The paper is a brief of the contributions of the team re-search at the project type A applied to CNCSIS "Research on the Role of XML in Building Extensible and Homogeneous ERP Systems".

Statistical discovery of site inter-dependencies in sub-molecular hierarchical protein structuring.

Science.gov (United States)

Durston, Kirk K; Chiu, David Ky; Wong, Andrew Kc; Li, Gary Cl

2012-07-13

Much progress has been made in understanding the 3D structure of proteins using methods such as NMR and X-ray crystallography. The resulting 3D structures are extremely informative, but do not always reveal which sites and residues within the structure are of special importance. Recently, there are indications that multiple-residue, sub-domain structural relationships within the larger 3D consensus structure of a protein can be inferred from the analysis of the multiple sequence alignment data of a protein family. These intra-dependent clusters of associated sites are used to indicate hierarchical inter-residue relationships within the 3D structure. To reveal the patterns of associations among individual amino acids or sub-domain components within the structure, we apply a k-modes attribute (aligned site) clustering algorithm to the ubiquitin and transthyretin families in order to discover associations among groups of sites within the multiple sequence alignment. We then observe what these associations imply within the 3D structure of these two protein families. The k-modes site clustering algorithm we developed maximizes the intra-group interdependencies based on a normalized mutual information measure. The clusters formed correspond to sub-structural components or binding and interface locations. Applying this data-directed method to the ubiquitin and transthyretin protein family multiple sequence alignments as a test bed, we located numerous interesting associations of interdependent sites. These clusters were then arranged into cluster tree diagrams which revealed four structural sub-domains within the single domain structure of ubiquitin and a single large sub-domain within transthyretin associated with the interface among transthyretin monomers. In addition, several clusters of mutually interdependent sites were discovered for each protein family, each of which appear to play an important role in the molecular structure and/or function. Our results

Multicriteria Analysis of Assembling Buildings from Steel Frame Structures

Science.gov (United States)

Miniotaite, Ruta

2017-10-01

Steel frame structures are often used in the construction of public and industrial buildings. They are used for: all types of slope roofs; walls of newly-built public and industrial buildings; load bearing structures; roofs of renovated buildings. The process of assembling buildings from steel frame structures should be analysed as an integrated process influenced by such factors as construction materials and machinery used, the qualification level of construction workers, complexity of work, available finance. It is necessary to find a rational technological design solution for assembling buildings from steel frame structures by conducting a multiple criteria analysis. The analysis provides a possibility to evaluate the engineering considerations and find unequivocal solutions. The rational alternative of a complex process of assembling buildings from steel frame structures was found through multiple criteria analysis and multiple criteria evaluation. In multiple criteria evaluation of technological solutions for assembling buildings from steel frame structures by pairwise comparison method the criteria by significance are distributed as follows: durability is the most important criterion in the evaluation of alternatives; the price (EUR/unit of measurement) of a part of assembly process; construction workers’ qualification level (category); mechanization level of a part of assembling process (%), and complexity of assembling work (in points) are less important criteria.

Structural Group-based Auditing of Missing Hierarchical Relationships in UMLS

Science.gov (United States)

Chen, Yan; Gu, Huanying(Helen); Perl, Yehoshua; Geller, James

2009-01-01

The Metathesaurus of the UMLS was created by integrating various source terminologies. The inter-concept relationships were either integrated into the UMLS from the source terminologies or specially generated. Due to the extensive size and inherent complexity of the Metathesaurus, the accidental omission of some hierarchical relationships was inevitable. We present a recursive procedure which allows a human expert, with the support of an algorithm, to locate missing hierarchical relationships. The procedure starts with a group of concepts with exactly the same (correct) semantic type assignments. It then partitions the concepts, based on child-of hierarchical relationships, into smaller, singly rooted, hierarchically connected subgroups. The auditor only needs to focus on the subgroups with very few concepts and their concepts with semantic type reassignments. The procedure was evaluated by comparing it with a comprehensive manual audit and it exhibits a perfect error recall. PMID:18824248

Hierarchical Genetic Analysis of German Cockroach (Blattella germanica) Populations from within Buildings to across Continents

Science.gov (United States)

Vargo, Edward L.; Crissman, Jonathan R.; Booth, Warren; Santangelo, Richard G.; Mukha, Dmitry V.; Schal, Coby

2014-01-01

Understanding the population structure of species that disperse primarily by human transport is essential to predicting and controlling human-mediated spread of invasive species. The German cockroach (Blattella germanica) is a widespread urban invader that can actively disperse within buildings but is spread solely by human-mediated dispersal over longer distances; however, its population structure is poorly understood. Using microsatellite markers we investigated population structure at several spatial scales, from populations within single apartment buildings to populations from several cities across the U.S. and Eurasia. Both traditional measures of genetic differentiation and Bayesian clustering methods revealed increasing levels of genetic differentiation at greater geographic scales. Our results are consistent with active dispersal of cockroaches largely limited to movement within a building. Their low levels of genetic differentiation, yet limited active spread between buildings, suggests a greater likelihood of human-mediated dispersal at more local scales (within a city) than at larger spatial scales (within and between continents). About half the populations from across the U.S. clustered together with other U.S. populations, and isolation by distance was evident across the U.S. Levels of genetic differentiation among Eurasian cities were greater than those in the U.S. and greater than those between the U.S. and Eurasia, but no clear pattern of structure at the continent level was detected. MtDNA sequence variation was low and failed to reveal any geographical structure. The weak genetic structure detected here is likely due to a combination of historical admixture among populations and periodic population bottlenecks and founder events, but more extensive studies are needed to determine whether signatures of global movement may be present in this species. PMID:25020136

A Probabilistic Model for Exteriors of Residential Buildings

KAUST Repository

Fan, Lubin

2016-07-29

We propose a new framework to model the exterior of residential buildings. The main goal of our work is to design a model that can be learned from data that is observable from the outside of a building and that can be trained with widely available data such as aerial images and street-view images. First, we propose a parametric model to describe the exterior of a building (with a varying number of parameters) and propose a set of attributes as a building representation with fixed dimensionality. Second, we propose a hierarchical graphical model with hidden variables to encode the relationships between building attributes and learn both the structure and parameters of the model from the database. Third, we propose optimization algorithms to generate three-dimensional models based on building attributes sampled from the graphical model. Finally, we demonstrate our framework by synthesizing new building models and completing partially observed building models from photographs.

Energy-efficient hierarchical processing in the network of wireless intelligent sensors (WISE)

Science.gov (United States)

Raskovic, Dejan

Sensor network nodes have benefited from technological advances in the field of wireless communication, processing, and power sources. However, the processing power of microcontrollers is often not sufficient to perform sophisticated processing, while the power requirements of digital signal processing boards or handheld computers are usually too demanding for prolonged system use. We are matching the intrinsic hierarchical nature of many digital signal-processing applications with the natural hierarchy in distributed wireless networks, and building the hierarchical system of wireless intelligent sensors. Our goal is to build a system that will exploit the hierarchical organization to optimize the power consumption and extend battery life for the given time and memory constraints, while providing real-time processing of sensor signals. In addition, we are designing our system to be able to adapt to the current state of the environment, by dynamically changing the algorithm through procedure replacement. This dissertation presents the analysis of hierarchical environment and methods for energy profiling used to evaluate different system design strategies, and to optimize time-effective and energy-efficient processing.

The Relationship between Self-Leadership and Personality: A Comparison of Hierarchical Factor Structures

OpenAIRE

Houghton, Jeffery D.

2000-01-01

This study examined the relationship between self-leadership and personality through an analysis and comparison of hierarchical factor structures. More specifically, this study examined the relationships between the self-leadership dimensions of behavior-focused strategies, natural reward strategies, and constructive thought strategies, and the personality dimensions of extraversion, emotional stability, and conscientiousness. The results of the study provide evidence that the self-leadershi...

Multi-Hierarchical Gray Correlation Analysis Applied in the Selection of Green Building Design Scheme

Science.gov (United States)

Wang, Li; Li, Chuanghong

2018-02-01

As a sustainable form of ecological structure, green building is widespread concerned and advocated in society increasingly nowadays. In the survey and design phase of preliminary project construction, carrying out the evaluation and selection of green building design scheme, which is in accordance with the scientific and reasonable evaluation index system, can improve the ecological benefits of green building projects largely and effectively. Based on the new Green Building Evaluation Standard which came into effect on January 1, 2015, the evaluation index system of green building design scheme is constructed taking into account the evaluation contents related to the green building design scheme. We organized experts who are experienced in construction scheme optimization to mark and determine the weight of each evaluation index through the AHP method. The correlation degree was calculated between each evaluation scheme and ideal scheme by using multilevel gray relational analysis model and then the optimal scheme was determined. The feasibility and practicability of the evaluation method are verified by introducing examples.

Page Layout Analysis of the Document Image Based on the Region Classification in a Decision Hierarchical Structure

Directory of Open Access Journals (Sweden)

Hossein Pourghassem

2010-10-01

Full Text Available The conversion of document image to its electronic version is a very important problem in the saving, searching and retrieval application in the official automation system. For this purpose, analysis of the document image is necessary. In this paper, a hierarchical classification structure based on a two-stage segmentation algorithm is proposed. In this structure, image is segmented using the proposed two-stage segmentation algorithm. Then, the type of the image regions such as document and non-document image is determined using multiple classifiers in the hierarchical classification structure. The proposed segmentation algorithm uses two algorithms based on wavelet transform and thresholding. Texture features such as correlation, homogeneity and entropy that extracted from co-occurrenc matrix and also two new features based on wavelet transform are used to classifiy and lable the regions of the image. The hierarchical classifier is consisted of two Multilayer Perceptron (MLP classifiers and a Support Vector Machine (SVM classifier. The proposed algorithm is evaluated on a database consisting of document and non-document images that provides from Internet. The experimental results show the efficiency of the proposed approach in the region segmentation and classification. The proposed algorithm provides accuracy rate of 97.5% on classification of the regions.

Fabrication of semi-transparent superoleophobic thin film from fabrics and nanoparticle-based hierarchical structure

Directory of Open Access Journals (Sweden)

Nishizawa S.

2013-08-01

Full Text Available Superoleophobic thin films have many potential applications including fluid transfer, fluid power systems, stain resistant and antifouling materials, and microfluidics among others. Transparency is also desired with superhydrophobicity for their numerous applications; however transparency and oleophobicity are almost incompatible relationship with each other in the point of surface structure. Because oleophobicity required rougher structure at nano-micro scale than hydrophobicity, and these rough structure brings light scattering. So far, there is very few report of the compatible of transparency and superoleophobicity. In this report, we proposed the see-through type fabrics using the nanoparticle-based hierarchical structure thin film for improving both of oleophobicity and transparency. The vacant space between fibrils of fabrics has two important roles: the one is to through the light, another one is to introduce air layer to realize Cassie state of liquid droplet on thin film. To realize the low surface energy and nanoscale rough structure surface on fibrils, we used the spray method with perfluoroalkyl methacrylic copolymer (PMC, silica nano particles and volatile solvent. From the SEM image, the hierarchical structures of nanoparticle were formed uniformly on the fabrics. The transparency of thin film obtained was approximately 61% and the change of transparency between pre-coated fabrics and coated was 11%. From investigation of the surface wettability, the contact angles of oils (rapeseed oil and hexadecane and water droplet on the fabricated film were over 150 degree.

Hierarchical classification with a competitive evolutionary neural tree.

Science.gov (United States)

Adams, R G.; Butchart, K; Davey, N

1999-04-01

A new, dynamic, tree structured network, the Competitive Evolutionary Neural Tree (CENT) is introduced. The network is able to provide a hierarchical classification of unlabelled data sets. The main advantage that the CENT offers over other hierarchical competitive networks is its ability to self determine the number, and structure, of the competitive nodes in the network, without the need for externally set parameters. The network produces stable classificatory structures by halting its growth using locally calculated heuristics. The results of network simulations are presented over a range of data sets, including Anderson's IRIS data set. The CENT network demonstrates its ability to produce a representative hierarchical structure to classify a broad range of data sets.

Synthesis of a hierarchically structured zeolite-templated carbon starting from fly ash-derived zeolite X

CSIR Research Space (South Africa)

Musyoka, Nicholas M

2014-05-01

Full Text Available A hierarchically structured zeolite derived from coal fly ash was used as a hard templating agent for the synthesis of a templated carbonaceous material. The samples were characterized using XRD, SEM, TEM, TGA, EDS and BET. The resulting carbon had...

A Review of Influence of Various Types of Structural Bracing to the Structural Performance of Buildings

Science.gov (United States)

Razak, S. M.; Kong, T. C.; Zainol, N. Z.; Adnan, A.; Azimi, M.

2018-03-01

Excessive lateral drift can contribute significantly towards crack formation, leading to structural damage. The structural damage will in turn reduce the capacity of the structure and weaken it from the intended design capacity. Generally, lateral drift is more pronounced in higher and longer structure, such as high rise buildings and bridges. A typical method employed to control lateral drift is structural bracing, which works by increasing stiffness and stability of structure. This paper reviews the influence of various types of structural bracing to structural performance of buildings. The history of structural bracing is visited and the differences between numerous structural bracing in term of suitability to different types of buildings and loading, mechanisms, technical details, advantages and limitations, and the overall effect on the structural behaviour and performance are dissected. Proper and efficient structural bracing is pertinent for each high rise building as this will lead towards safer, sustainable and more economical buildings, which are cheaper to maintain throughout the life of the buildings in the future.

Hierarchically Nanoporous Bioactive Glasses for High Efficiency Immobilization of Enzymes

DEFF Research Database (Denmark)

He, W.; Min, D.D.; Zhang, X.D.

2014-01-01

Bioactive glasses with hierarchical nanoporosity and structures have been heavily involved in immobilization of enzymes. Because of meticulous design and ingenious hierarchical nanostructuration of porosities from yeast cell biotemplates, hierarchically nanostructured porous bioactive glasses can...... and products of catalytic reactions can freely diffuse through open mesopores (2–40 nm). The formation mechanism of hierarchically structured porous bioactive glasses, the immobilization mechanism of enzyme and the catalysis mechanism of immobilized enzyme are then discussed. The novel nanostructure...

Co3O4 based non-enzymatic glucose sensor with high sensitivity and reliable stability derived from hollow hierarchical architecture

Science.gov (United States)

Tian, Liangliang; He, Gege; Cai, Yanhua; Wu, Shenping; Su, Yongyao; Yan, Hengqing; Yang, Cong; Chen, Yanling; Li, Lu

2018-02-01

Inspired by kinetics, the design of hollow hierarchical electrocatalysts through large-scale integration of building blocks is recognized as an effective approach to the achievement of superior electrocatalytic performance. In this work, a hollow, hierarchical Co3O4 architecture (Co3O4 HHA) was constructed using a coordinated etching and precipitation (CEP) method followed by calcination. The resulting Co3O4 HHA electrode exhibited excellent electrocatalytic activity in terms of high sensitivity (839.3 μA mM-1 cm-2) and reliable stability in glucose detection. The high sensitivity could be attributed to the large specific surface area (SSA), ample unimpeded penetration diffusion paths and high electron transfer rate originating from the unique two-dimensional (2D) sheet-like character and hollow porous architecture. The hollow hierarchical structure also affords sufficient interspace for accommodation of volume change and structural strain, resulting in enhanced stability. The results indicate that Co3O4 HHA could have potential for application in the design of non-enzymatic glucose sensors, and that the construction of hollow hierarchical architecture provides an efficient way to design highly active, stable electrocatalysts.

Automated detection of repeated structures in building facades

Directory of Open Access Journals (Sweden)

M. Previtali

2013-10-01

Full Text Available Automatic identification of high-level repeated structures in 3D point clouds of building façades is crucial for applications like digitalization and building modelling. Indeed, in many architectural styles building façades are governed by arrangements of objects into repeated patterns. In particular, façades are generally designed as the repetition of some few basic objects organized into interlaced and\\or concatenated grid structures. Starting from this key observation, this paper presents an algorithm for Repeated Structure Detection (RSD in 3D point clouds of building façades. The presented methodology consists of three main phases. First, in the point cloud segmentation stage (i the building façade is decomposed into planar patches which are classified by means of some weak prior knowledge of urban buildings formulated in a classification tree. Secondly (ii, in the element clustering phase detected patches are grouped together by means of a similarity function and pairwise transformations between patches are computed. Eventually (iii, in the structure regularity estimation step the parameters of repeated grid patterns are calculated by using a Least- Squares optimization. Workability of the presented approach is tested using some real data from urban scenes.

Bayesian Hierarchical Structure for Quantifying Population Variability to Inform Probabilistic Health Risk Assessments.

Science.gov (United States)

Shao, Kan; Allen, Bruce C; Wheeler, Matthew W

2017-10-01

Human variability is a very important factor considered in human health risk assessment for protecting sensitive populations from chemical exposure. Traditionally, to account for this variability, an interhuman uncertainty factor is applied to lower the exposure limit. However, using a fixed uncertainty factor rather than probabilistically accounting for human variability can hardly support probabilistic risk assessment advocated by a number of researchers; new methods are needed to probabilistically quantify human population variability. We propose a Bayesian hierarchical model to quantify variability among different populations. This approach jointly characterizes the distribution of risk at background exposure and the sensitivity of response to exposure, which are commonly represented by model parameters. We demonstrate, through both an application to real data and a simulation study, that using the proposed hierarchical structure adequately characterizes variability across different populations. © 2016 Society for Risk Analysis.

Formation process of hierarchical structures in crystalline polymers as analyzed by simultaneous measurements of small-angle X-ray scattering and other techniques

International Nuclear Information System (INIS)

Yamamoto, Katsuhiro; Sakurai, Shinichi

2006-01-01

Crystalline polymers spontaneously form hierarchical structures, which provide us a potential use as a specialty material. Recently, not only a crystalline homopolymer but also semi-crystalline block copolymers and crystalline polymer blends have been attracting interests for the study of a hierarchical structure. In order to analyze such hierarchical structures in a variety of length scales, a simultaneous measurement of small-(SAXS) and wide-angle (WAXS) X-ray scattering with differential scanning calorimetry (DSC), or with small-angle light scattering (Hv-SALS) are most suitable. In this review, we show some examples of the simultaneous measurements. With DSC, exothermic heat flow can be simultaneously measured with X-ray scattering. On the other hand, with Hv-SALS it is possible to analyze evolution of a spherulitic structure, which is the structure at the highest rank in the hierarchy. For both cases, one can realize that it is impossible to obtain good statistics for SAXS and WAXS measurements without synchrotron radiations. (author)

Synthesis and Characterization of Wooden Magnetic Activated Carbon Fibers with Hierarchical Pore Structures

Directory of Open Access Journals (Sweden)

Dongna Li

2018-04-01

Full Text Available Wooden magnetic activated carbon fibers (WMACFs with hierarchical pore structures were obtained by adding magnetic iron oxide (Fe3O4 nanoparticles into the liquefied wood. The structures and properties of WMACFs were analyzed by scanning electronmicroscopy (SEM, X-ray diffraction (XRD, Fourier transform infrared spectroscopy (FTIR, N2 adsorption, and vibrating sample magnetometer (VSM. The results showed that WMACFs had high Brunauer-Emmett-Teller (BET surface area (1578 m2/g and total pore volume (0.929 cm3/g, of which 45% was the contribution of small mesopores of 2–3 nm. It is believed that Fe3O4 nanoparticles play an important role in the formation of hierarchical pores. With the Fe3O4 content increasing, the yield rate of WMACFs decreased, and the Fe3O4 crystal plane diffraction peaks and characteristic adsorption peaks were obviously observed. At the same time, it was also found that WMACFs had favorable magnetic properties when the Fe3O4 content was above 1.5%. As a result, WMACFs could be a promising candidate for high efficiency, low cost, and convenient separation for the magnetic field.

30 CFR 57.4530 - Exits for surface buildings and structures.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Exits for surface buildings and structures. 57... Fire Prevention and Control Installation/construction/maintenance § 57.4530 Exits for surface buildings and structures. Surface buildings or structures in which persons work shall have a sufficient number...

Hierarchical Micro-Nano Coatings by Painting

Science.gov (United States)

Kirveslahti, Anna; Korhonen, Tuulia; Suvanto, Mika; Pakkanen, Tapani A.

2016-03-01

In this paper, the wettability properties of coatings with hierarchical surface structures and low surface energy were studied. Hierarchically structured coatings were produced by using hydrophobic fumed silica nanoparticles and polytetrafluoroethylene (PTFE) microparticles as additives in polyester (PES) and polyvinyldifluoride (PVDF). These particles created hierarchical micro-nano structures on the paint surfaces and lowered or supported the already low surface energy of the paint. Two standard application techniques for paint application were employed and the presented coatings are suitable for mass production and use in large surface areas. By regulating the particle concentrations, it was possible to modify wettability properties gradually. Highly hydrophobic surfaces were achieved with the highest contact angle of 165∘. Dynamic contact angle measurements were carried out for a set of selected samples and low hysteresis was obtained. Produced coatings possessed long lasting durability in the air and in underwater conditions.

Visualization of hierarchically structured information for human-computer interaction

Energy Technology Data Exchange (ETDEWEB)

Cheon, Suh Hyun; Lee, J. K.; Choi, I. K.; Kye, S. C.; Lee, N. K. [Dongguk University, Seoul (Korea)

2001-11-01

Visualization techniques can be used to support operator's information navigation tasks on the system especially consisting of an enormous volume of information, such as operating information display system and computerized operating procedure system in advanced control room of nuclear power plants. By offering an easy understanding environment of hierarchically structured information, these techniques can reduce the operator's supplementary navigation task load. As a result of that, operators can pay more attention on the primary tasks and ultimately improve the cognitive task performance. In this report, an interface was designed and implemented using hyperbolic visualization technique, which is expected to be applied as a means of optimizing operator's information navigation tasks. 15 refs., 19 figs., 32 tabs. (Author)

Topics in Computational Bayesian Statistics With Applications to Hierarchical Models in Astronomy and Sociology

Science.gov (United States)

Sahai, Swupnil

This thesis includes three parts. The overarching theme is how to analyze structured hierarchical data, with applications to astronomy and sociology. The first part discusses how expectation propagation can be used to parallelize the computation when fitting big hierarchical bayesian models. This methodology is then used to fit a novel, nonlinear mixture model to ultraviolet radiation from various regions of the observable universe. The second part discusses how the Stan probabilistic programming language can be used to numerically integrate terms in a hierarchical bayesian model. This technique is demonstrated on supernovae data to significantly speed up convergence to the posterior distribution compared to a previous study that used a Gibbs-type sampler. The third part builds a formal latent kernel representation for aggregate relational data as a way to more robustly estimate the mixing characteristics of agents in a network. In particular, the framework is applied to sociology surveys to estimate, as a function of ego age, the age and sex composition of the personal networks of individuals in the United States.

Scaling of the first-passage time of biased diffusion on hierarchical comb structures

International Nuclear Information System (INIS)

Lin Zhifang; Tao Ruibao.

1989-12-01

Biased diffusion on hierarchical comb structures is studied within an exact renormalization group scheme. The scaling exponents of the moments of the first-passage time for random walks are obtained. It is found that the scaling properties of the diffusion depend only on the direction of bias. In this particular case, the presence of bias may give rise to a new multifractality. (author). 7 refs, 2 figs

Bioinspired Omnidirectional Self-Stable Reflectors with Multiscale Hierarchical Structures.

Science.gov (United States)

Han, Zhiwu; Mu, Zhengzhi; Li, Bo; Feng, Xiaoming; Wang, Ze; Zhang, Junqiu; Niu, Shichao; Ren, Luquan

2017-08-30

Structured surfaces, demonstrating various wondrous physicochemical performances, are ubiquitous phenomena in nature. Butterfly wings with impressive structural colors are an interesting example for multiscale hierarchical structures (MHSs). However, most natural structural colors are relatively unstable and highly sensitive to incident angles, which limit their potential practical applications to a certain extent. Here, we reported a bioinspired color reflector with omnidirectional reflective self-stable (ORS) properties, which is inspired by the wing scales of Papilio palinurus butterfly. Through experimental exploration and theoretical analysis, it was found that the vivid colors of such butterfly wings are structure-based and possess novel ORS properties, which attributes to the multiple optical actions between light and the complex structures coupling the inverse opal-like structures (IOSs) and stacked lamellar ridges (SLRs). On the basis of this, we designed and successfully fabricated the SiO 2 -based bioinspired color reflectors (BCRs) through a facile and effective biotemplate method. It was confirmed that the MHSs in biotemplate are inherited by the obtained SiO 2 -based BCRs. More importantly, the SiO 2 -based BCRs also demonstrated the similar ORS properties in a wide wavelength range. We forcefully anticipate that the reported MHS-based ORS performance discovered in butterfly wing scales here could offer new thoughts for scientists to solve unstable reflection issues in particular optical field. The involved biotemplate fabrication method offers a facile and effective strategy for fabricating functional nanomaterials or bioinspired nanodevices with 3D complex nanostructures, such as structured optical devices, displays, and optoelectronic equipment.

Construction of a Hierarchical Architecture of Covalent Organic Frameworks via a Postsynthetic Approach.

Science.gov (United States)

Zhang, Gen; Tsujimoto, Masahiko; Packwood, Daniel; Duong, Nghia Tuan; Nishiyama, Yusuke; Kadota, Kentaro; Kitagawa, Susumu; Horike, Satoshi

2018-02-21

Covalent organic frameworks (COFs) represent an emerging class of crystalline porous materials that are constructed by the assembly of organic building blocks linked via covalent bonds. Several strategies have been developed for the construction of new COF structures; however, a facile approach to fabricate hierarchical COF architectures with controlled domain structures remains a significant challenge, and has not yet been achieved. In this study, a dynamic covalent chemistry (DCC)-based postsynthetic approach was employed at the solid-liquid interface to construct such structures. Two-dimensional imine-bonded COFs having different aromatic groups were prepared, and a homogeneously mixed-linker structure and a heterogeneously core-shell hollow structure were fabricated by controlling the reactivity of the postsynthetic reactions. Solid-state nuclear magnetic resonance (NMR) spectroscopy and transmission electron microscopy (TEM) confirmed the structures. COFs prepared by a postsynthetic approach exhibit several functional advantages compared with their parent phases. Their Brunauer-Emmett-Teller (BET) surface areas are 2-fold greater than those of their parent phases because of the higher crystallinity. In addition, the hydrophilicity of the material and the stepwise adsorption isotherms of H 2 O vapor in the hierarchical frameworks were precisely controlled, which was feasible because of the distribution of various domains of the two COFs by controlling the postsynthetic reaction. The approach opens new routes for constructing COF architectures with functionalities that are not possible in a single phase.

Hierarchical virtual screening approaches in small molecule drug discovery.

Science.gov (United States)

Kumar, Ashutosh; Zhang, Kam Y J

2015-01-01

Virtual screening has played a significant role in the discovery of small molecule inhibitors of therapeutic targets in last two decades. Various ligand and structure-based virtual screening approaches are employed to identify small molecule ligands for proteins of interest. These approaches are often combined in either hierarchical or parallel manner to take advantage of the strength and avoid the limitations associated with individual methods. Hierarchical combination of ligand and structure-based virtual screening approaches has received noteworthy success in numerous drug discovery campaigns. In hierarchical virtual screening, several filters using ligand and structure-based approaches are sequentially applied to reduce a large screening library to a number small enough for experimental testing. In this review, we focus on different hierarchical virtual screening strategies and their application in the discovery of small molecule modulators of important drug targets. Several virtual screening studies are discussed to demonstrate the successful application of hierarchical virtual screening in small molecule drug discovery. Copyright © 2014 Elsevier Inc. All rights reserved.

Symptom structure of PTSD: support for a hierarchical model separating core PTSD symptoms from dysphoria

NARCIS (Netherlands)

Rademaker, Arthur R.; van Minnen, Agnes; Ebberink, Freek; van Zuiden, Mirjam; Hagenaars, Muriel A.; Geuze, Elbert

2012-01-01

As of yet, no collective agreement has been reached regarding the precise factor structure of posttraumatic stress disorder (PTSD). Several alternative factor-models have been proposed in the last decades. The current study examined the fit of a hierarchical adaptation of the Simms et al. (2002)

Category theoretic analysis of hierarchical protein materials and social networks.

Directory of Open Access Journals (Sweden)

David I Spivak

Full Text Available Materials in biology span all the scales from Angstroms to meters and typically consist of complex hierarchical assemblies of simple building blocks. Here we describe an application of category theory to describe structural and resulting functional properties of biological protein materials by developing so-called ologs. An olog is like a "concept web" or "semantic network" except that it follows a rigorous mathematical formulation based on category theory. This key difference ensures that an olog is unambiguous, highly adaptable to evolution and change, and suitable for sharing concepts with other olog. We consider simple cases of beta-helical and amyloid-like protein filaments subjected to axial extension and develop an olog representation of their structural and resulting mechanical properties. We also construct a representation of a social network in which people send text-messages to their nearest neighbors and act as a team to perform a task. We show that the olog for the protein and the olog for the social network feature identical category-theoretic representations, and we proceed to precisely explicate the analogy or isomorphism between them. The examples presented here demonstrate that the intrinsic nature of a complex system, which in particular includes a precise relationship between structure and function at different hierarchical levels, can be effectively represented by an olog. This, in turn, allows for comparative studies between disparate materials or fields of application, and results in novel approaches to derive functionality in the design of de novo hierarchical systems. We discuss opportunities and challenges associated with the description of complex biological materials by using ologs as a powerful tool for analysis and design in the context of materiomics, and we present the potential impact of this approach for engineering, life sciences, and medicine.

Structured building model reduction toward parallel simulation

Energy Technology Data Exchange (ETDEWEB)

Dobbs, Justin R. [Cornell University; Hencey, Brondon M. [Cornell University

2013-08-26

Building energy model reduction exchanges accuracy for improved simulation speed by reducing the number of dynamical equations. Parallel computing aims to improve simulation times without loss of accuracy but is poorly utilized by contemporary simulators and is inherently limited by inter-processor communication. This paper bridges these disparate techniques to implement efficient parallel building thermal simulation. We begin with a survey of three structured reduction approaches that compares their performance to a leading unstructured method. We then use structured model reduction to find thermal clusters in the building energy model and allocate processing resources. Experimental results demonstrate faster simulation and low error without any interprocessor communication.

Optically controlled three-dimensional assembly of microfabricated building blocks

DEFF Research Database (Denmark)

Rodrigo, Peter John; Kelemen, Lorand; Palima, Darwin

2009-01-01

We demonstrate a system for constructing reconfigurable microstructures using multiple, real-time configurable counterpropagating-beam traps. We optically assemble geometrically complementary microstructures with complex three-dimensional (3D) topologies produced by two-photon polymerization....... This demonstrates utilization of controllable 3D optical traps for building hierarchical structures from microfabricated building blocks. Optical microassembly with translational and tip-tilt control in 3D achieved by dynamic multiple CB traps can potentially facilitate the construction of functional microdevices...... and may also lead to the future realization of optically actuated micromachines. Fabricating morphologically complex microstructures and then optically manipulating these archetypal building blocks can also be used to construct reconfigurable microenvironments that can aid in understanding cellular...

Assessment of structural reliability of precast concrete buildings

Directory of Open Access Journals (Sweden)

Koyankin Alexandr

2018-01-01

Full Text Available Precast housing construction is currently being under rapid development, however, reliability of building structures made from precast reinforced concrete cannot be assessed rationally due to insufficient research data on that subject. In this regard, experimental and numerical studies were conducted to assess structural reliability of precast buildings as described in the given paper. Experimental studies of full-scale and model samples were conducted; numerical studies were held based on finite element models using “Lira” software. The objects under study included fragment of flooring of a building under construction, full-size fragment of flooring, full-scale models of precast cross-beams-to-columns joints and joints between hollow-core floor slabs and precast and cast-in-place cross-beams. Conducted research enabled to perform an objective assessment of structural reliability of precast buildings.

Biomimetic fabrication and tunable wetting properties of three-dimensional hierarchical ZnO structures by combining soft lithography templated with lotus leaf and hydrothermal treatments

OpenAIRE

Dai, Shuxi; Zhang, Dianbo; Shi, Qing; Han, Xiao; Wang, Shujie; Du, Zuliang

2013-01-01

Three-dimensional hierarchical ZnO films with lotus-leaf-like micro/nano structures were successfully fabricated via a biomimetic route combining sol-gel technique, soft lithography and hydrothermal treatments. PDMS mold replicated from a fresh lotus leaf was used to imprint microscale pillar structures directly into a ZnO sol film. Hierarchical ZnO micro/nano structures were subsequently fabricated by a low-temperature hydrothermal growth of secondary ZnO nanorod arrays on the micro-structur...

Interaction of light with hematite hierarchical structures: Experiments and simulations

Science.gov (United States)

Distaso, Monica; Zhuromskyy, Oleksander; Seemann, Benjamin; Pflug, Lukas; Mačković, Mirza; Encina, Ezequiel; Taylor, Robin Klupp; Müller, Rolf; Leugering, Günter; Spiecker, Erdmann; Peschel, Ulf; Peukert, Wolfgang

2017-03-01

Mesocrystalline particles have been recognized as a class of multifunctional materials with potential applications in different fields. However, the internal organization of nanocomposite mesocrystals and its influence on the final properties have not yet been investigated. In this paper, a novel strategy based on electrodynamic simulations is developed to shed light on how the internal structure of mesocrystals influences their optical properties. In a first instance, a unified design protocol is reported for the fabrication of hematite/PVP particles with different morphologies such as pseudo-cubes, rods-like and apple-like structures and controlled particle size distributions. The optical properties of hematite/PVP mesocrystals are effectively simulated by taking their aggregate and nanocomposite structure into consideration. The superposition T-Matrix approach accounts for the aggregate nature of mesocrystalline particles and validate the effective medium approximation used in the framework of the Mie theory and electromagnetic simulation such as Finite Element Method. The approach described in our paper provides the framework to understand and predict the optical properties of mesocrystals and more general, of hierarchical nanostructured particles.

Structure of urban movements: polycentric activity and entangled hierarchical flows.

Directory of Open Access Journals (Sweden)

Camille Roth

Full Text Available The spatial arrangement of urban hubs and centers and how individuals interact with these centers is a crucial problem with many applications ranging from urban planning to epidemiology. We utilize here in an unprecedented manner the large scale, real-time 'Oyster' card database of individual person movements in the London subway to reveal the structure and organization of the city. We show that patterns of intraurban movement are strongly heterogeneous in terms of volume, but not in terms of distance travelled, and that there is a polycentric structure composed of large flows organized around a limited number of activity centers. For smaller flows, the pattern of connections becomes richer and more complex and is not strictly hierarchical since it mixes different levels consisting of different orders of magnitude. This new understanding can shed light on the impact of new urban projects on the evolution of the polycentric configuration of a city and the dense structure of its centers and it provides an initial approach to modeling flows in an urban system.

Hierarchically structured transparent hybrid membranes by in situ growth of mesostructured organosilica in host polymer

Science.gov (United States)

Vallé, Karine; Belleville, Philippe; Pereira, Franck; Sanchez, Clément

2006-02-01

The elaborate performances characterizing natural materials result from functional hierarchical constructions at scales ranging from nanometres to millimetres, each construction allowing the material to fit the physical or chemical demands occurring at these different levels. Hierarchically structured materials start to demonstrate a high input in numerous promising applied domains such as sensors, catalysis, optics, fuel cells, smart biologic and cosmetic vectors. In particular, hierarchical hybrid materials permit the accommodation of a maximum of elementary functions in a small volume, thereby optimizing complementary possibilities and properties between inorganic and organic components. The reported strategies combine sol-gel chemistry, self-assembly routes using templates that tune the material's architecture and texture with the use of larger inorganic, organic or biological templates such as latex, organogelator-derived fibres, nanolithographic techniques or controlled phase separation. We propose an approach to forming transparent hierarchical hybrid functionalized membranes using in situ generation of mesostructured hybrid phases inside a non-porogenic hydrophobic polymeric host matrix. We demonstrate that the control of the multiple affinities existing between organic and inorganic components allows us to design the length-scale partitioning of hybrid nanomaterials with tuned functionalities and desirable size organization from ångström to centimetre. After functionalization of the mesoporous hybrid silica component, the resulting membranes have good ionic conductivity offering interesting perspectives for the design of solid electrolytes, fuel cells and other ion-transport microdevices.

Copper oxide assisted cysteine hierarchical structures for immunosensor application

Energy Technology Data Exchange (ETDEWEB)

Pandey, Chandra Mouli [Biomedical Instrumentation Section, CSIR-National Physical Laboratory, New Delhi 110012 (India); Department of Chemistry, Faculty of Science, Banaras Hindu University, Varanasi 221005 (India); Sumana, Gajjala, E-mail: sumanagajjala@gmail.com [Biomedical Instrumentation Section, CSIR-National Physical Laboratory, New Delhi 110012 (India); Tiwari, Ida [Department of Chemistry, Faculty of Science, Banaras Hindu University, Varanasi 221005 (India)

2014-09-08

The present work describes the promising electrochemical immunosensing strategy based on copper (II) assisted hierarchical cysteine structures (CuCys) varying from star to flower like morphology. The CuCys having average size of 10 μm have been synthesised using L-Cysteine as initial precursor in presence of copper oxide under environmentally friendly conditions in aqueous medium. To delineate the synthesis mechanism, detailed structural investigations have been carried out using characterization techniques such as X-ray diffraction, transmission electron microscopy, and Fourier transform infrared spectroscopy. The electrochemical behaviour of self-assembled CuCys on gold electrode shows surface controlled electrode reaction with an apparent electron transfer rate constant of 3.38 × 10{sup −4 }cm s{sup −1}. This innovative platform has been utilized to fabricate an immunosensor by covalently immobilizing monoclonal antibodies specific for Escherichia coli O157:H7 (E. coli). Under the optimal conditions, the fabricated immunosensor is found to be sensitive and specific for the detection of E. coli with a detection limit of 10 cfu/ml.

Building occupancy diversity and HVAC (heating, ventilation, and air conditioning) system energy efficiency

International Nuclear Information System (INIS)

Yang, Zheng; Ghahramani, Ali; Becerik-Gerber, Burcin

2016-01-01

Approximately forty percent of total building energy consumption is attributed to HVAC (heating, ventilation, and air conditioning) systems that aim to maintain healthy and comfortable indoor environments. An HVAC system is a network with several subsystems, and there exist heat transfer and balance among the zones of a building, as well as heat gains and losses through a building's envelope. Diverse occupancy (diversity in terms of when and how occupants occupy a building) in spaces could result in increase of loads that are not actual demands for an HVAC system, leading into inefficiencies. This paper introduces a framework to quantitatively evaluate the energy implications of occupancy diversity at the building level, where building information modeling is integrated to provide building geometries, HVAC system layouts, and spatial information as inputs for computing potential energy implications if occupancy diversity were to be eliminated. An agglomerate hierarchical clustering-based iterative evaluation algorithm is designed for iteratively eliminating occupancy diversity. Whole building energy simulations for a real-world building, as well as virtual reference buildings demonstrate that the proposed framework could effectively quantify the HVAC system energy efficiency affected by occupancy diversity and the framework is generalizable to different building geometries, layouts, and occupancy diversities. - Highlights: • Analyze relationships between occupancy diversity and HVAC energy efficiency. • Integrate BIM for quantifying energy implications of occupancy diversity. • Demonstrate the effectiveness and generalizability of iterative evaluation algorithm. • Improve agglomerative hierarchical clustering process using heap data structure.

FEM Updating of the Heritage Court Building Structure

DEFF Research Database (Denmark)

Ventura, C. E.; Brincker, Rune; Dascotte, E.

2001-01-01

. The starting model of the structure was developed from the information provided in the design documentation of the building. Different parameters of the model were then modified using an automated procedure to improve the correlation between measured and calculated modal parameters. Careful attention......This paper describes results of a model updating study conducted on a 15-storey reinforced concrete shear core building. The output-only modal identification results obtained from ambient vibration measurements of the building were used to update a finite element model of the structure...

* Hierarchically Structured Electrospun Scaffolds with Chemically Conjugated Growth Factor for Ligament Tissue Engineering.

Science.gov (United States)

Pauly, Hannah M; Sathy, Binulal N; Olvera, Dinorath; McCarthy, Helen O; Kelly, Daniel J; Popat, Ketul C; Dunne, Nicholas J; Haut Donahue, Tammy Lynn

2017-08-01

The anterior cruciate ligament (ACL) of the knee is vital for proper joint function and is commonly ruptured during sports injuries or car accidents. Due to a lack of intrinsic healing capacity and drawbacks with allografts and autografts, there is a need for a tissue-engineered ACL replacement. Our group has previously used aligned sheets of electrospun polycaprolactone nanofibers to develop solid cylindrical bundles of longitudinally aligned nanofibers. We have shown that these nanofiber bundles support cell proliferation and elongation and the hierarchical structure and material properties are similar to the native human ACL. It is possible to combine multiple nanofiber bundles to create a scaffold that attempts to mimic the macroscale structure of the ACL. The goal of this work was to develop a hierarchical bioactive scaffold for ligament tissue engineering using connective tissue growth factor (CTGF)-conjugated nanofiber bundles and evaluate the behavior of mesenchymal stem cells (MSCs) on these scaffolds in vitro and in vivo. CTGF was immobilized onto the surface of individual nanofiber bundles or scaffolds consisting of multiple nanofiber bundles. The conjugation efficiency and the release of conjugated CTGF were assessed using X-ray photoelectron spectroscopy, assays, and immunofluorescence staining. Scaffolds were seeded with MSCs and maintained in vitro for 7 days (individual nanofiber bundles), in vitro for 21 days (scaled-up scaffolds of 20 nanofiber bundles), or in vivo for 6 weeks (small scaffolds of 4 nanofiber bundles), and ligament-specific tissue formation was assessed in comparison to non-CTGF-conjugated control scaffolds. Results showed that CTGF conjugation encouraged cell proliferation and ligament-specific tissue formation in vitro and in vivo. The results suggest that hierarchical electrospun nanofiber bundles conjugated with CTGF are a scalable and bioactive scaffold for ACL tissue engineering.

Hierarchical regression analysis in structural Equation Modeling

NARCIS (Netherlands)

de Jong, P.F.

1999-01-01

In a hierarchical or fixed-order regression analysis, the independent variables are entered into the regression equation in a prespecified order. Such an analysis is often performed when the extra amount of variance accounted for in a dependent variable by a specific independent variable is the main

FRF-based structural damage detection of controlled buildings with podium structures: Experimental investigation

Science.gov (United States)

Xu, Y. L.; Huang, Q.; Zhan, S.; Su, Z. Q.; Liu, H. J.

2014-06-01

How to use control devices to enhance system identification and damage detection in relation to a structure that requires both vibration control and structural health monitoring is an interesting yet practical topic. In this study, the possibility of using the added stiffness provided by control devices and frequency response functions (FRFs) to detect damage in a building complex was explored experimentally. Scale models of a 12-storey main building and a 3-storey podium structure were built to represent a building complex. Given that the connection between the main building and the podium structure is most susceptible to damage, damage to the building complex was experimentally simulated by changing the connection stiffness. To simulate the added stiffness provided by a semi-active friction damper, a steel circular ring was designed and used to add the related stiffness to the building complex. By varying the connection stiffness using an eccentric wheel excitation system and by adding or not adding the circular ring, eight cases were investigated and eight sets of FRFs were measured. The experimental results were used to detect damage (changes in connection stiffness) using a recently proposed FRF-based damage detection method. The experimental results showed that the FRF-based damage detection method could satisfactorily locate and quantify damage.

Hierarchical surfaces for enhanced self-cleaning applications

Science.gov (United States)

Fernández, Ariadna; Francone, Achille; Thamdrup, Lasse H.; Johansson, Alicia; Bilenberg, Brian; Nielsen, Theodor; Guttmann, Markus; Sotomayor Torres, Clivia M.; Kehagias, Nikolaos

2017-04-01

In this study we present a flexible and adaptable fabrication method to create complex hierarchical structures over inherently hydrophobic resist materials. We have tested these surfaces for their superhydrophobic behaviour and successfully verified their self-cleaning properties. The followed approach allow us to design and produce superhydrophobic surfaces in a reproducible manner. We have analysed different combination of hierarchical micro-nanostructures for their application to self-cleaning surfaces. A static contact angle value of 170° with a hysteresis of 4° was achieved without the need of any additional chemical treatment on the fabricated hierarchical structures. Dynamic effects were analysed on these surfaces, obtaining a remarkable self-cleaning effect as well as a good robustness over impacting droplets.

Hierarchical CuO hollow microspheres: Controlled synthesis for enhanced lithium storage performance

International Nuclear Information System (INIS)

Guan Xiangfeng; Li Liping; Li Guangshe; Fu Zhengwei; Zheng Jing; Yan Tingjiang

2011-01-01

Graphical abstract: Hierarchical CuO microspheres with hollow interiors were formed through self-wrapping of a single layer of radically oriented CuO nanorods, and these microspheres showed excellent cycle performance and enhanced lithium storage capacity. Display Omitted Research highlights: → Hierarchical CuO hollow microspheres were prepared by a hydrothermal method. → The CuO hollow microspheres were assembled from radically oriented nanorods. → The growth mechanism was proposed to proceed via self-assembly and Ostwald's ripening. → The microspheres showed good cycle performance and enhanced lithium storage capacity. → Hierarchical microstructures with hollow interiors promote electrochemical property. - Abstract: In this work, hierarchical CuO hollow microspheres were hydrothermally prepared without use of any surfactants or templates. By controlling the formation reaction conditions and monitoring the relevant reaction processes using time-dependent experiments, it is demonstrated that hierarchical CuO microspheres with hollow interiors were formed through self-wrapping of a single layer of radically oriented CuO nanorods, and that hierarchical spheres could be tuned to show different morphologies and microstructures. As a consequence, the formation mechanism was proposed to proceed via a combined process of self-assembly and Ostwald's ripening. Further, these hollow microspheres were initiated as the anode material in lithium ion batteries, which showed excellent cycle performance and enhanced lithium storage capacity, most likely because of the synergetic effect of small diffusion lengths in building blocks of nanorods and proper void space that buffers the volume expansion. The strategy reported in this work is reproducible, which may help to significantly improve the electrochemical performance of transition metal oxide-based anode materials via designing the hollow structures necessary for developing lithium ion batteries and the relevant

Super-hydrophobic nickel films with micro-nano hierarchical structure prepared by electrodeposition

International Nuclear Information System (INIS)

Hang Tao; Hu Anmin; Ling Huiqin; Li Ming; Mao Dali

2010-01-01

Super-hydrophobic nickel films were prepared by a simple and low cost electrodepositing method. The surface morphologies of the films characterized by scanning electronic microscope exhibit hierarchical structure with micro-nanocones array, which can be responsible for their super-hydrophobic characteristic (water contact angle over 150 o ) without chemical modification. The wettability of the film can be varied from super-hydrophobic (water contact angle 154 o ) to relatively hydrophilic (water contact angle 87 o ) by controlling the size of the micro-nanocones. The mechanism of the hydrophobic characteristic of nickel films with this unique structure was illustrated by several models. Such micro-nanostructure and its special wettability are expected to be applied in the practical industry.

Anti-hierarchical evolution of the active galactic nucleus space density in a hierarchical universe

International Nuclear Information System (INIS)

Enoki, Motohiro; Ishiyama, Tomoaki; Kobayashi, Masakazu A. R.; Nagashima, Masahiro

2014-01-01

Recent observations show that the space density of luminous active galactic nuclei (AGNs) peaks at higher redshifts than that of faint AGNs. This downsizing trend in the AGN evolution seems to be contradictory to the hierarchical structure formation scenario. In this study, we present the AGN space density evolution predicted by a semi-analytic model of galaxy and AGN formation based on the hierarchical structure formation scenario. We demonstrate that our model can reproduce the downsizing trend of the AGN space density evolution. The reason for the downsizing trend in our model is a combination of the cold gas depletion as a consequence of star formation, the gas cooling suppression in massive halos, and the AGN lifetime scaling with the dynamical timescale. We assume that a major merger of galaxies causes a starburst, spheroid formation, and cold gas accretion onto a supermassive black hole (SMBH). We also assume that this cold gas accretion triggers AGN activity. Since the cold gas is mainly depleted by star formation and gas cooling is suppressed in massive dark halos, the amount of cold gas accreted onto SMBHs decreases with cosmic time. Moreover, AGN lifetime increases with cosmic time. Thus, at low redshifts, major mergers do not always lead to luminous AGNs. Because the luminosity of AGNs is correlated with the mass of accreted gas onto SMBHs, the space density of luminous AGNs decreases more quickly than that of faint AGNs. We conclude that the anti-hierarchical evolution of the AGN space density is not contradictory to the hierarchical structure formation scenario.

Anti-hierarchical evolution of the active galactic nucleus space density in a hierarchical universe

Energy Technology Data Exchange (ETDEWEB)

Enoki, Motohiro [Faculty of Business Administration, Tokyo Keizai University, Kokubunji, Tokyo 185-8502 (Japan); Ishiyama, Tomoaki [Center for Computational Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8577 (Japan); Kobayashi, Masakazu A. R. [Research Center for Space and Cosmic Evolution, Ehime University, Matsuyama, Ehime 790-8577 (Japan); Nagashima, Masahiro, E-mail: enokimt@tku.ac.jp [Faculty of Education, Nagasaki University, Nagasaki, Nagasaki 852-8521 (Japan)

2014-10-10

Recent observations show that the space density of luminous active galactic nuclei (AGNs) peaks at higher redshifts than that of faint AGNs. This downsizing trend in the AGN evolution seems to be contradictory to the hierarchical structure formation scenario. In this study, we present the AGN space density evolution predicted by a semi-analytic model of galaxy and AGN formation based on the hierarchical structure formation scenario. We demonstrate that our model can reproduce the downsizing trend of the AGN space density evolution. The reason for the downsizing trend in our model is a combination of the cold gas depletion as a consequence of star formation, the gas cooling suppression in massive halos, and the AGN lifetime scaling with the dynamical timescale. We assume that a major merger of galaxies causes a starburst, spheroid formation, and cold gas accretion onto a supermassive black hole (SMBH). We also assume that this cold gas accretion triggers AGN activity. Since the cold gas is mainly depleted by star formation and gas cooling is suppressed in massive dark halos, the amount of cold gas accreted onto SMBHs decreases with cosmic time. Moreover, AGN lifetime increases with cosmic time. Thus, at low redshifts, major mergers do not always lead to luminous AGNs. Because the luminosity of AGNs is correlated with the mass of accreted gas onto SMBHs, the space density of luminous AGNs decreases more quickly than that of faint AGNs. We conclude that the anti-hierarchical evolution of the AGN space density is not contradictory to the hierarchical structure formation scenario.

Structural acceptance criteria Remote Handling Building Tritium Extraction Facility

Energy Technology Data Exchange (ETDEWEB)

Mertz, G.

1999-12-16

This structural acceptance criteria contains the requirements for the structural analysis and design of the Remote Handling Building (RHB) in the Tritium Extraction Facility (TEF). The purpose of this acceptance criteria is to identify the specific criteria and methods that will ensure a structurally robust building that will safely perform its intended function and comply with the applicable Department of Energy (DOE) structural requirements.

Structural acceptance criteria Remote Handling Building Tritium Extraction Facility

International Nuclear Information System (INIS)

Mertz, G.

1999-01-01

This structural acceptance criteria contains the requirements for the structural analysis and design of the Remote Handling Building (RHB) in the Tritium Extraction Facility (TEF). The purpose of this acceptance criteria is to identify the specific criteria and methods that will ensure a structurally robust building that will safely perform its intended function and comply with the applicable Department of Energy (DOE) structural requirements

ERP Responses to Violations in the Hierarchical Structure of Functional Categories in Japanese Verb Conjugation

Science.gov (United States)

Kobayashi, Yuki; Sugioka, Yoko; Ito, Takane

2018-01-01

An event-related potential experiment was conducted in order to investigate readers' response to violations in the hierarchical structure of functional categories in Japanese, an agglutinative language where functional heads like Negation (Neg) as well as Tense (Tns) are realized as suffixes. A left-lateralized negativity followed by a P600 was…

Biomolecule-Assisted Hydrothermal Synthesis and Self-Assembly of Bi2Te3 Nanostring-Cluster Hierarchical Structure

DEFF Research Database (Denmark)

Mi, Jianli; Lock, Nina; Sun, Ting

2010-01-01

A simple biomolecule-assisted hydrothermal approach has been developed for the fabrication of Bi2Te3 thermoelectric nanomaterials. The product has a nanostring-cluster hierarchical structure which is composed of ordered and aligned platelet-like crystals. The platelets are100 nm in diameter...

Hierarchical Analysis of the Omega Ontology

Energy Technology Data Exchange (ETDEWEB)

Joslyn, Cliff A.; Paulson, Patrick R.

2009-12-01

Initial delivery for mathematical analysis of the Omega Ontology. We provide an analysis of the hierarchical structure of a version of the Omega Ontology currently in use within the US Government. After providing an initial statistical analysis of the distribution of all link types in the ontology, we then provide a detailed order theoretical analysis of each of the four main hierarchical links present. This order theoretical analysis includes the distribution of components and their properties, their parent/child and multiple inheritance structure, and the distribution of their vertical ranks.

One-Step Synthesis of Hierarchical ZSM-5 Using Cetyltrimethylammonium as Mesoporogen and Structure-Directing Agent

OpenAIRE

Meng, Lingqian; Mezari, Brahim; Goesten, Maarten G.; Hensen, Emiel J. M.

2017-01-01

Hierarchical ZSM-5 zeolite is hydrothermally synthesized in a single step with cetyltrimethylammonium (CTA) hydroxide acting as mesoporogen and structure-directing agent. Essential to this synthesis is the replacement of NaOH with KOH. An in-depth solid-state NMR study reveals that, after early electrostatic interaction between condensed silica and the head group of CTA, ZSM-5 crystallizes around the structure-directing agent. The crucial aspect of using KOH instead of NaOH lies in the faster...

A hierarchical method for structural topology design problems with local stress and displacement constraints

DEFF Research Database (Denmark)

Stolpe, Mathias; Stidsen, Thomas K.

2005-01-01

In this paper we present a hierarchical optimization method for finding feasible true 0-1 solutions to finite element based topology design problems. The topology design problems are initially modeled as non-convex mixed 0-1 programs. The hierarchical optimization method is applied to the problem...... and then successively refined as needed. At each level of design mesh refinement, a neighborhood optimization method is used to solve the problem considered. The non-convex topology design problems are equivalently reformulated as convex all-quadratic mixed 0-1 programs. This reformulation enables the use of methods...... of minimizing the weight of a structure subject to displacement and local design-dependent stress constraints. The method iteratively solves a sequence of problems of increasing size of the same type as the original problem. The problems are defined on a design mesh which is initially coarse...

Analysis of the structural design process of the adaptive reuse of building structures

NARCIS (Netherlands)

Pasterkamp, S.

2014-01-01

In the field of structural building engineering there is a market shift taking place as a result of the growing number of buildings that are listed as cultural heritage, secularization, the economic situation and the increasing office vacancy rate in Europe and the US. More and more structural

Performance evaluation of existing building structure with pushover analysis

Science.gov (United States)

Handana, MAP; Karolina, R.; Steven

2018-02-01

In the management of the infrastructure of the building, during the period of buildings common building damage as a result of several reasons, earthquakes are common. The building is planned to work for a certain service life. But during the certain service life, the building vulnerable to damage due to various things. Any damage to cultivate can be detected as early as possible, because the damage could spread, triggering and exacerbating the latest. The newest concept to earthquake engineering is Performance Based Earthquake Engineering (PBEE). PBEE divided into two, namely Performance Based Seismic Design (PBSD) and Performance Based Seismic Evaluation (PBSE). Evaluation on PBSE one of which is the analysis of nonlinear pushover. Pushover analysis is a static analysis of nonlinear where the influence of the earthquake plan on building structure is considered as burdens static catch at the center of mass of each floor, which it was increased gradually until the loading causing the melting (plastic hinge) first within the building structure, then the load increases further changes the shapes of post-elastic large it reached the condition of elastic. Then followed melting (plastic hinge) in the location of the other structured.

Elementary structural building blocks encountered in silicon surface reconstructions

International Nuclear Information System (INIS)

Battaglia, Corsin; Monney, Claude; Didiot, Clement; Schwier, Eike Fabian; Garnier, Michael Gunnar; Aebi, Philipp; Gaal-Nagy, Katalin; Onida, Giovanni

2009-01-01

Driven by the reduction of dangling bonds and the minimization of surface stress, reconstruction of silicon surfaces leads to a striking diversity of outcomes. Despite this variety even very elaborate structures are generally comprised of a small number of structural building blocks. We here identify important elementary building blocks and discuss their integration into the structural models as well as their impact on the electronic structure of the surface. (topical review)

Hierarchical Nanoceramics for Industrial Process Sensors

Energy Technology Data Exchange (ETDEWEB)

Ruud, James, A.; Brosnan, Kristen, H.; Striker, Todd; Ramaswamy, Vidya; Aceto, Steven, C.; Gao, Yan; Willson, Patrick, D.; Manoharan, Mohan; Armstrong, Eric, N., Wachsman, Eric, D.; Kao, Chi-Chang

2011-07-15

This project developed a robust, tunable, hierarchical nanoceramics materials platform for industrial process sensors in harsh-environments. Control of material structure at multiple length scales from nano to macro increased the sensing response of the materials to combustion gases. These materials operated at relatively high temperatures, enabling detection close to the source of combustion. It is anticipated that these materials can form the basis for a new class of sensors enabling widespread use of efficient combustion processes with closed loop feedback control in the energy-intensive industries. The first phase of the project focused on materials selection and process development, leading to hierarchical nanoceramics that were evaluated for sensing performance. The second phase focused on optimizing the materials processes and microstructures, followed by validation of performance of a prototype sensor in a laboratory combustion environment. The objectives of this project were achieved by: (1) synthesizing and optimizing hierarchical nanostructures; (2) synthesizing and optimizing sensing nanomaterials; (3) integrating sensing functionality into hierarchical nanostructures; (4) demonstrating material performance in a sensing element; and (5) validating material performance in a simulated service environment. The project developed hierarchical nanoceramic electrodes for mixed potential zirconia gas sensors with increased surface area and demonstrated tailored electrocatalytic activity operable at high temperatures enabling detection of products of combustion such as NOx close to the source of combustion. Methods were developed for synthesis of hierarchical nanostructures with high, stable surface area, integrated catalytic functionality within the structures for gas sensing, and demonstrated materials performance in harsh lab and combustion gas environments.

Static and dynamic friction of hierarchical surfaces.

Science.gov (United States)

Costagliola, Gianluca; Bosia, Federico; Pugno, Nicola M

2016-12-01

Hierarchical structures are very common in nature, but only recently have they been systematically studied in materials science, in order to understand the specific effects they can have on the mechanical properties of various systems. Structural hierarchy provides a way to tune and optimize macroscopic mechanical properties starting from simple base constituents and new materials are nowadays designed exploiting this possibility. This can be true also in the field of tribology. In this paper we study the effect of hierarchical patterned surfaces on the static and dynamic friction coefficients of an elastic material. Our results are obtained by means of numerical simulations using a one-dimensional spring-block model, which has previously been used to investigate various aspects of friction. Despite the simplicity of the model, we highlight some possible mechanisms that explain how hierarchical structures can significantly modify the friction coefficients of a material, providing a means to achieve tunability.

Models test on dynamic structure-structure interaction of nuclear power plant buildings

International Nuclear Information System (INIS)

Kitada, Y.; Hirotani, T.

1999-01-01

A reactor building of an NPP (nuclear power plant) is generally constructed closely adjacent to a turbine building and other buildings such as the auxiliary building, and in increasing numbers of NPPs, multiple plants are being planned and constructed closely on a single site. In these situations, adjacent buildings are considered to influence each other through the soil during earthquakes and to exhibit dynamic behaviour different from that of separate buildings, because those buildings in NPP are generally heavy and massive. The dynamic interaction between buildings during earthquake through the soil is termed here as 'dynamic cross interaction (DCI)'. In order to comprehend DCI appropriately, forced vibration tests and earthquake observation are needed using closely constructed building models. Standing on this background, Nuclear Power Engineering Corporation (NUPEC) had planned the project to investigate the DCI effect in 1993 after the preceding SSI (soil-structure interaction) investigation project, 'model tests on embedment effect of reactor building'. The project consists of field and laboratory tests. The field test is being carried out using three different building construction conditions, e.g. a single reactor building to be used for the comparison purposes as for a reference, two same reactor buildings used to evaluate pure DCI effects, and two different buildings, reactor and turbine building models to evaluate DCI effects under the actual plant conditions. Forced vibration tests and earthquake observations are planned in the field test. The laboratory test is planned to evaluate basic characteristics of the DCI effects using simple soil model made of silicon rubber and structure models made of aluminum. In this test, forced vibration tests and shaking table tests are planned. The project was started in April 1994 and will be completed in March 2002. This paper describes an outline and the summary of the current status of this project. (orig.)

A top-down approach for fabricating free-standing bio-carbon supercapacitor electrodes with a hierarchical structure

OpenAIRE

Yingzhi Li; Qinghua Zhang; Junxian Zhang; Lei Jin; Xin Zhao; Ting Xu

2015-01-01

Biomass has delicate hierarchical structures, which inspired us to develop a cost-effective route to prepare electrode materials with rational nanostructures for use in high-performance storage devices. Here, we demonstrate a novel top-down approach for fabricating bio-carbon materials with stable structures and excellent diffusion pathways; this approach is based on carbonization with controlled chemical activation. The developed free-standing bio-carbon electrode exhibits a high specific ca...

Hierarchical surfaces for enhanced self-cleaning applications

International Nuclear Information System (INIS)

Fernández, Ariadna; Francone, Achille; Sotomayor Torres, Clivia M; Kehagias, Nikolaos; Thamdrup, Lasse H; Johansson, Alicia; Bilenberg, Brian; Nielsen, Theodor; Guttmann, Markus

2017-01-01

In this study we present a flexible and adaptable fabrication method to create complex hierarchical structures over inherently hydrophobic resist materials. We have tested these surfaces for their superhydrophobic behaviour and successfully verified their self-cleaning properties. The followed approach allow us to design and produce superhydrophobic surfaces in a reproducible manner. We have analysed different combination of hierarchical micro-nanostructures for their application to self-cleaning surfaces. A static contact angle value of 170° with a hysteresis of 4° was achieved without the need of any additional chemical treatment on the fabricated hierarchical structures. Dynamic effects were analysed on these surfaces, obtaining a remarkable self-cleaning effect as well as a good robustness over impacting droplets. (paper)

A Persistent Structured Hierarchical Overlay Network to Counter Intentional Churn Attack

Directory of Open Access Journals (Sweden)

Ramanpreet Kaur

2016-01-01

Full Text Available The increased use of structured overlay network for a variety of applications has attracted a lot of attention from both research community and attackers. However, the structural constraints, open nature (anybody can join and anybody may leave, and unreliability of its participant nodes significantly affect the performance of these applications and make it vulnerable to a variety of attacks such as eclipse, Sybil, and churn. One attack to compromise the service availability in overlay network is intentional churn (join/leave attack, where a large number of malicious users will join and leave the overlay network so frequently that the entire structure collapses and becomes unavailable. The focus of this paper is to provide a new robust, efficient, and scalable hierarchical overlay architecture that will counter these attacks by providing a structure that can accommodate the fleeting behaviour of nodes without causing much structural inconsistencies. The performance evaluation showed that the proposed architecture has more failure resilience and self-organization as compared to chord based architecture. Experimental results have demonstrated that the effect of failures on an overlay is proportional to the size of failure.

Hierarchical porous microspheres of the Co3O4@graphene with enhanced electrocatalytic performance for electrochemical biosensors.

Science.gov (United States)

Yang, MinHo; Jeong, Jae-Min; Lee, Kyoung G; Kim, Do Hyun; Lee, Seok Jae; Choi, Bong Gill

2017-03-15

The integration of organic and inorganic building blocks into hierarchical porous architectures makes potentially desirable electrocatalytic materials in many electrochemical applications due to their combination of attractive qualities of dissimilar components and well-constructed charge transfer pathways. Herein, we demonstrate the preparation of the hierarchical porous Co 3 O 4 @graphene (Co 3 O 4 @G) microspheres by one-step hydrothermal method to achieve high electrocatalytic performance for enzyme-free biosensor applications. The obtained Co 3 O 4 @G microspheres are consisted of the interconnected networks of Co 3 O 4 and graphene sheets, and thus provide large accessible active sites through porous structure, while graphene sheets offer continuous electron pathways for efficient electrocatalytic reaction of Co 3 O 4 . These structural merits with synergy effect of Co 3 O 4 and graphene lead to a high performance of enzyme-free detection for glucose: high sensitivity, good selectivity, and remarkable stability. Copyright © 2016 Elsevier B.V. All rights reserved.

The hierarchical structure of childhood personality in five countries: continuity from early childhood to early adolescence.

Science.gov (United States)

Tackett, Jennifer L; Slobodskaya, Helena R; Mar, Raymond A; Deal, James; Halverson, Charles F; Baker, Spencer R; Pavlopoulos, Vassilis; Besevegis, Elias

2012-08-01

Childhood personality is a rapidly growing area of investigation within individual differences research. One understudied topic is the universality of the hierarchical structure of childhood personality. In the present investigation, parents rated the personality characteristics of 3,751 children from 5 countries and 4 age groups. The hierarchical structure of childhood personality was examined for 1-, 2-, 3-, 4-, and 5-factor models across country (Canada, China, Greece, Russia, and the United States) and age group (3-5, 6-8, 9-11, and 12-14 years of age). Many similarities were noted across both country and age. The Five-Factor Model was salient beginning in early childhood (ages 3-5). Deviations across groups and from adult findings are noted, including the prominent role of antagonism in childhood personality and the high covariation between Conscientiousness and intellect. Future directions, including the need for more explicit attempts to merge temperament and personality models, are discussed. © 2011 The Authors. Journal of Personality © 2011, Wiley Periodicals, Inc.

Does pop music exist? Hierarchical structure in phonographic markets

Science.gov (United States)

Buda, Andrzej

2012-11-01

I find a topological arrangement of assets traded in phonographic markets which has associated a meaningful economic taxonomy. I continue using the Minimal Spanning Tree and the correlations between assets, but now outside the stock markets. This is the first attempt to use these methods on phonographic markets where we have artists instead of stocks. The value of an artist is defined by record sales. The graph is obtained starting from the matrix of correlation coefficients computed between the world’s most popular 30 artists by considering the synchronous time evolution of the difference of the logarithm of weekly record sales. This method provides the hierarchical structure of the phonographic market and information on which music genre is meaningful according to customers. Statistical properties (including the Hurst exponent) of weekly record sales in the phonographic market are also discussed.

Topology of foreign exchange markets using hierarchical structure methods

Science.gov (United States)

Naylor, Michael J.; Rose, Lawrence C.; Moyle, Brendan J.

2007-08-01

This paper uses two physics derived hierarchical techniques, a minimal spanning tree and an ultrametric hierarchical tree, to extract a topological influence map for major currencies from the ultrametric distance matrix for 1995-2001. We find that these two techniques generate a defined and robust scale free network with meaningful taxonomy. The topology is shown to be robust with respect to method, to time horizon and is stable during market crises. This topology, appropriately used, gives a useful guide to determining the underlying economic or regional causal relationships for individual currencies and to understanding the dynamics of exchange rate price determination as part of a complex network.

Hierarchical capillary adhesion of microcantilevers or hairs

International Nuclear Information System (INIS)

Liu Jianlin; Feng Xiqiao; Xia Re; Zhao Hongping

2007-01-01

As a result of capillary forces, animal hairs, carbon nanotubes or nanowires of a periodically or randomly distributed array often assemble into hierarchical structures. In this paper, the energy method is adopted to analyse the capillary adhesion of microsized hairs, which are modelled as clamped microcantilevers wetted by liquids. The critical conditions for capillary adhesion of two hairs, three hairs or two bundles of hairs are derived in terms of Young's contact angle, elastic modulus and geometric sizes of the beams. Then, the hierarchical capillary adhesion of hairs is addressed. It is found that for multiple hairs or microcantilevers, the system tends to take a hierarchical structure as a result of the minimization of the total potential energy of the system. The level number of structural hierarchy increases with the increase in the number of hairs if they are sufficiently long. Additionally, we performed experiments to verify our theoretical solutions for the adhesion of microbeams

One-step synthesis of g-C{sub 3}N{sub 4} hierarchical porous structure nanosheets with dramatic ultraviolet light photocatalytic activity

Energy Technology Data Exchange (ETDEWEB)

Lu, Jing; Wang, Yong; Huang, Jianfeng, E-mail: huangjfsust@126.com; Cao, Liyun; Li, Jiayin; Hai, Guojuan; Bai, Zhe

2016-12-15

Highlights: • g-C{sub 3}N{sub 4} nanosheets with hierarchical porous structure were synthesized via one step. • The band gap of the nanosheets was wider and investigated in detail. • The nanosheets can degrade almost all of the RhB within 9 min. • The photocurrent of the nanosheets is 5.97 times as high as that of the P-25. - Abstract: Graphitic carbon nitride (g-C{sub 3}N{sub 4}) nanosheets with hierarchical porous structure were synthesized via one-step thermal condensation-oxidation process. The microstructure of g-C{sub 3}N{sub 4} was characterized to explain the dramatic ultraviolet light photocatalytic activity. The results showed that g-C{sub 3}N{sub 4} hierarchical aggregates were assembled by nanosheets with a length of 1–2 μm and a thickness of 20–30 nm. And the N{sub 2}-adsorption/desorption isotherms further informed the presence of fissure form mesoporous structure. An enhanced photocurrent of 37.2 μA was obtained, which is almost 5 times higher than that of P-25. Besides, the g-C{sub 3}N{sub 4} nanosheets displayed the degradation of Rhodamine B with 99.4% removal efficiency in only 9 min. Such highly photocatalytic activity could be attributed to the nano platelet morphology which improves electron transport ability along the in-plane direction. In addition, the hierarchical porous structure adapted a wider band gap of C{sub 3}N{sub 4}. Therefore, the photoinduced electron-hole pairs have a stronger oxidation-reduction potential for photocatalysis.

Trees and Hierarchical Structures

CERN Document Server

Haeseler, Arndt

1990-01-01

The "raison d'etre" of hierarchical dustering theory stems from one basic phe­ nomenon: This is the notorious non-transitivity of similarity relations. In spite of the fact that very often two objects may be quite similar to a third without being that similar to each other, one still wants to dassify objects according to their similarity. This should be achieved by grouping them into a hierarchy of non-overlapping dusters such that any two objects in ~ne duster appear to be more related to each other than they are to objects outside this duster. In everyday life, as well as in essentially every field of scientific investigation, there is an urge to reduce complexity by recognizing and establishing reasonable das­ sification schemes. Unfortunately, this is counterbalanced by the experience of seemingly unavoidable deadlocks caused by the existence of sequences of objects, each comparatively similar to the next, but the last rather different from the first.

Programming with Hierarchical Maps

DEFF Research Database (Denmark)

Ørbæk, Peter

This report desribes the hierarchical maps used as a central data structure in the Corundum framework. We describe its most prominent features, ague for its usefulness and briefly describe some of the software prototypes implemented using the technology....

Ways of looking ahead: hierarchical planning in language production.

Science.gov (United States)

Lee, Eun-Kyung; Brown-Schmidt, Sarah; Watson, Duane G

2013-12-01

It is generally assumed that language production proceeds incrementally, with chunks of linguistic structure planned ahead of speech. Extensive research has examined the scope of language production and suggests that the size of planned chunks varies across contexts (Ferreira & Swets, 2002; Wagner & Jescheniak, 2010). By contrast, relatively little is known about the structure of advance planning, specifically whether planning proceeds incrementally according to the surface structure of the utterance, or whether speakers plan according to the hierarchical relationships between utterance elements. In two experiments, we examine the structure and scope of lexical planning in language production using a picture description task. Analyses of speech onset times and word durations show that speakers engage in hierarchical planning such that structurally dependent lexical items are planned together and that hierarchical planning occurs for both direct and indirect dependencies. Copyright © 2013 Elsevier B.V. All rights reserved.

Towards Sustainable Smart Homes by a Hierarchical Hybrid Architecture of an Intelligent Agent

Directory of Open Access Journals (Sweden)

K. Yang

2016-10-01

Full Text Available A smart home can be realized by the provision of services, such as building control, automation and security implemented in accordance with a user’s request. One of the important issues is how to respond quickly and appropriately to a user’s request in a “dynamic environment”. An intelligent agent infers the user’s intention and provides the intact service. This paper proposes a smart home agent system based on a hierarchical hybrid architecture of a user intention model, which models the user intention as a hierarchical structure and implements it in a dynamic environment. The conventional rule-based approach needs to obtain all information before it is executed, which requires a large number of rules and is hardly scalable as the control objects are increasing. On the other hand, the proposed system consists of several modules that construct a hierarchical user intention model. The smart home system needs to take account of the information, such as time, state of device and state of the home, in addition to users’ intention. We evaluate the performance of the proposed system in a dynamic environment and conduct a blind test with seven subjects to measure the satisfaction of service, resulting in the average score of 81.46.

Structure-function relationship in complex brain networks expressed by hierarchical synchronization

International Nuclear Information System (INIS)

Zhou Changsong; Zemanova, Lucia; Zamora-Lopez, Gorka; Hilgetag, Claus C; Kurths, Juergen

2007-01-01

The brain is one of the most complex systems in nature, with a structured complex connectivity. Recently, large-scale corticocortical connectivities, both structural and functional, have received a great deal of research attention, especially using the approach of complex network analysis. Understanding the relationship between structural and functional connectivity is of crucial importance in neuroscience. Here we try to illuminate this relationship by studying synchronization dynamics in a realistic anatomical network of cat cortical connectivity. We model the nodes (cortical areas) by a neural mass model (population model) or by a subnetwork of interacting excitable neurons (multilevel model). We show that if the dynamics is characterized by well-defined oscillations (neural mass model and subnetworks with strong couplings), the synchronization patterns are mainly determined by the node intensity (total input strengths of a node) and the detailed network topology is rather irrelevant. On the other hand, the multilevel model with weak couplings displays more irregular, biologically plausible dynamics, and the synchronization patterns reveal a hierarchical cluster organization in the network structure. The relationship between structural and functional connectivity at different levels of synchronization is explored. Thus, the study of synchronization in a multilevel complex network model of cortex can provide insights into the relationship between network topology and functional organization of complex brain networks

Structure-function relationship in complex brain networks expressed by hierarchical synchronization

Energy Technology Data Exchange (ETDEWEB)

Zhou Changsong [Institute of Physics, University of Potsdam, PF 601553, 14415 Potsdam (Germany); Zemanova, Lucia [Institute of Physics, University of Potsdam, PF 601553, 14415 Potsdam (Germany); Zamora-Lopez, Gorka [Institute of Physics, University of Potsdam, PF 601553, 14415 Potsdam (Germany); Hilgetag, Claus C [Jacobs University Bremen, Campus Ring 6, Rm 116, D-28759 Bremen (Germany); Kurths, Juergen [Institute of Physics, University of Potsdam, PF 601553, 14415 Potsdam (Germany)

2007-06-15

The brain is one of the most complex systems in nature, with a structured complex connectivity. Recently, large-scale corticocortical connectivities, both structural and functional, have received a great deal of research attention, especially using the approach of complex network analysis. Understanding the relationship between structural and functional connectivity is of crucial importance in neuroscience. Here we try to illuminate this relationship by studying synchronization dynamics in a realistic anatomical network of cat cortical connectivity. We model the nodes (cortical areas) by a neural mass model (population model) or by a subnetwork of interacting excitable neurons (multilevel model). We show that if the dynamics is characterized by well-defined oscillations (neural mass model and subnetworks with strong couplings), the synchronization patterns are mainly determined by the node intensity (total input strengths of a node) and the detailed network topology is rather irrelevant. On the other hand, the multilevel model with weak couplings displays more irregular, biologically plausible dynamics, and the synchronization patterns reveal a hierarchical cluster organization in the network structure. The relationship between structural and functional connectivity at different levels of synchronization is explored. Thus, the study of synchronization in a multilevel complex network model of cortex can provide insights into the relationship between network topology and functional organization of complex brain networks.

Hierarchical Rhetorical Sentence Categorization for Scientific Papers

Science.gov (United States)

Rachman, G. H.; Khodra, M. L.; Widyantoro, D. H.

2018-03-01

Important information in scientific papers can be composed of rhetorical sentences that is structured from certain categories. To get this information, text categorization should be conducted. Actually, some works in this task have been completed by employing word frequency, semantic similarity words, hierarchical classification, and the others. Therefore, this paper aims to present the rhetorical sentence categorization from scientific paper by employing TF-IDF and Word2Vec to capture word frequency and semantic similarity words and employing hierarchical classification. Every experiment is tested in two classifiers, namely Naïve Bayes and SVM Linear. This paper shows that hierarchical classifier is better than flat classifier employing either TF-IDF or Word2Vec, although it increases only almost 2% from 27.82% when using flat classifier until 29.61% when using hierarchical classifier. It shows also different learning model for child-category can be built by hierarchical classifier.

A facile approach to fabricate hierarchically structured poly(3-hexylthiophene-2,5-diyl) films

DEFF Research Database (Denmark)

Zhang, Weihua; Zong, Chuanyong; Xie, Jixun

2017-01-01

Microstructured surfaces have great potentials to improve the performances and efficiency of optoelectronic devices. In this work, a simple robust approach based on surface instabilities was presented to fabricate poly(3-hexylthiophene-2,5-diyl) (P3HT) films with ridge-like/wrinkled composite...... microstructures. Namely, the hierarchically patterned films were prepared by spin coating the P3HT/tetrahydrofuran (THF) solution on a polydimethylsiloxane (PDMS) substrate to form stable ridge-like structures, followed by solvent vapor swelling to create surface wrinkles with the orientation guided by the ridge......-like structures. During spin coating of the P3HT/THF solution, the ridge-like structures were generated by the in-situ template of the THF swelling-induced creasing structures on the PDMS substrate. To our knowledge, it is the first report that the creasing structures are used as a recoverable template...

A hierarchical method for discrete structural topology design problems with local stress and displacement constraints

DEFF Research Database (Denmark)

Stolpe, Mathias; Stidsen, Thomas K.

2007-01-01

In this paper, we present a hierarchical optimization method for finding feasible true 0-1 solutions to finite-element-based topology design problems. The topology design problems are initially modelled as non-convex mixed 0-1 programs. The hierarchical optimization method is applied to the problem...... and then successively refined as needed. At each level of design mesh refinement, a neighbourhood optimization method is used to treat the problem considered. The non-convex topology design problems are equivalently reformulated as convex all-quadratic mixed 0-1 programs. This reformulation enables the use of methods...... of minimizing the weight of a structure subject to displacement and local design-dependent stress constraints. The method iteratively treats a sequence of problems of increasing size of the same type as the original problem. The problems are defined on a design mesh which is initially coarse...

Evolution of Hierarchical Structure and Spatial Pattern of Coastal Cities in China – Based on the Data of Distribution of Marine-Related Enterprises

Directory of Open Access Journals (Sweden)

Wang Lili

2017-11-01

Full Text Available In this paper, a comprehensive research of the evolution of the hierarchical structure and spatial pattern of coastal cities in China was conducted based on the data of distribution of the headquarters and subsidiaries of marine-related enterprises in 1995, 2005 and 2015 using the city network research method proposed by Taylor. The results of the empirical research showed: China’s coastal city network had an obvious hierarchical characteristics of “national coastal cityregional coastal city-sub-regional coastal city-local coastal city”, in the 20 years of development process, the hierarchies of coastal cities in China showed a hierarchical progressive evolution; in past 20 years, the spatial pattern and network structure of coastal cities in China tended to be complete, and the city network was more uniform, forming a “three tiers and three urban agglomerations” network structure; the strength of connection among the cities was obviously strengthened, and the efficiency of urban spatial connection was improved overall.

Structural wood products in onshore buildings at Naval Station Norfolk, 2000.

Science.gov (United States)

David B. McKeever

2003-01-01

As of December 31, 2000, there were 603 buildings at Naval Station (NAVSTA) Norfolk with a combined floor area of nearly 17.3 million ft2. In one-third of these buildings, structural wood products were used in one or more major structural building applications, utilizing an estimated 11.6 million board feet of lumber, 0.4 million ft2 (3/8-in. basis) of structural...

Radar Mapping of Building Structures Applying Sparse Reconstruction

NARCIS (Netherlands)

Tan, R.G.; Wit, J.J.M. de; Rossum, W.L. van

2012-01-01

The ability to map building structures at a certain stand-off distance allows intelligence, reconnaissance, and clearance tasks to be performed in a covert way by driving around a building. This will greatly improve security, response time, and reliability of aforementioned tasks. Therefore,

Visible-light photocatalytic activity of Ag2O coated Bi2WO6 hierarchical microspheres assembled by nanosheets

International Nuclear Information System (INIS)

Chen, Lin; Hua, Hao; Yang, Qi; Hu, Chenguo

2015-01-01

Graphical abstract: - Highlights: • Bi 2 WO 6 hierarchical microspheres assembled by nanosheets and dispersed nanosheets are synthesized. • Ag 2 O/Bi 2 WO 6 heterostuctures exhibites an enhanced photocatalytic activity compared with the Bi 2 WO 6 nanostructures. • Photocatalytic activity of the Ag 2 O/Bi 2 WO 6 microspheres is higher than that of the nanosheets. • Bi 2 WO 6 hierarchical structure is an excellent architecture for loading of Ag 2 O nanoparticles. - Abstract: Bi 2 WO 6 hierarchical microspheres assembled by nanosheets and dispersed nanosheets were synthesized by hydrothermal reaction in different conditions. Ag 2 O nanoparticles were deposited on the surface of Bi 2 WO 6 microspheres and nanosheets by the chemical precipitation method. The photocatalytic performance of pure Bi 2 WO 6 nanostructures and Ag 2 O/Bi 2 WO 6 heterostructures were evaluated by the photocatalytic decolorization of RhB solution under visible-light irradiation. Compared with the pure Bi 2 WO 6 nanostructures, the Ag 2 O/Bi 2 WO 6 heterostructures exhibited an obviously enhanced photocatalytic activity. And photocatalytic activity of the Ag 2 O/Bi 2 WO 6 microspheres is higher than that of the Ag 2 O/Bi 2 WO 6 nanosheets. This work demonstrates that the Bi 2 WO 6 hierarchical three-dimensional structure is an excellent architecture for the loading of Ag 2 O nanoparticles to build a highly efficient photocatalyst

Constructive systems, load-bearing and enclosing structures of high-rise buildings

Science.gov (United States)

Anatol'evna Korol', Elena; Olegovna Kustikova, Yuliya

2018-03-01

As the height of the building increases, loads on load-carrying structures increase dramatically, and as a result of the development of high-rise construction, several structural systems of such buildings have been developed: frame, frame-frame, cross-wall, barrel, box-type, box-to-wall ("pipe in pipe", "Trumpet in the farm"), etc. In turn, the barrel systems have their own versions: cantilever support of the ceilings on the trunk, suspension of the outer part of the overlap to the upper carrying console "hanging house" or its support by means of the walls on the lower bearing cantilever, intermediate position of the supporting cantilevers in height to the floor, from a part of floors. The object of the study are the structural solutions of high-rise buildings. The subject of the study is the layout of structural schemes of high-rise buildings, taking into account the main parameters - altitude (height), natural climatic conditions of construction, materials of structural elements and their physical and mechanical characteristics. The purpose of the study is to identify the features and systematization of structural systems of high-rise buildings and the corresponding structural elements. The results of the research make it possible, at the stage of making design decisions, to establish rational parameters for the correspondence between the structural systems of high-rise buildings and their individual elements.

Ethical Guidelines for Structural Interventions to Small-Scale Historic Stone Masonry Buildings.

Science.gov (United States)

Hurol, Yonca; Yüceer, Hülya; Başarır, Hacer

2015-12-01

Structural interventions to historic stone masonry buildings require that both structural and heritage values be considered simultaneously. The absence of one of these value systems in implementation can be regarded as an unethical professional action. The research objective of this article is to prepare a guideline for ensuring ethical structural interventions to small-scale stone historic masonry buildings in the conservation areas of Northern Cyprus. The methodology covers an analysis of internationally accepted conservation documents and national laws related to the conservation of historic buildings, an analysis of building codes, especially Turkish building codes, which have been used in Northern Cyprus, and an analysis of the structural interventions introduced to a significant historic building in a semi-intact state in the walled city of Famagusta. This guideline covers issues related to whether buildings are intact or ruined, the presence of earthquake risk, the types of structural decisions in an architectural conservation project, and the values to consider during the decision making phase.

Task Switching in a Hierarchical Task Structure: Evidence for the Fragility of the Task Repetition Benefit

Science.gov (United States)

Lien, Mei-Ching; Ruthruff, Eric

2004-01-01

This study examined how task switching is affected by hierarchical task organization. Traditional task-switching studies, which use a constant temporal and spatial distance between each task element (defined as a stimulus requiring a response), promote a flat task structure. Using this approach, Experiment 1 revealed a large switch cost of 238 ms.…

Hierarchical cellular designs for load-bearing biocomposite beams and plates

International Nuclear Information System (INIS)

Burgueno, Rigoberto; Quagliata, Mario J.; Mohanty, Amar K.; Mehta, Geeta; Drzal, Lawrence T.; Misra, Manjusri

2005-01-01

Scrutiny into the composition of natural, or biological materials convincingly reveals that high material and structural efficiency can be attained, even with moderate-quality constituents, by hierarchical topologies, i.e., successively organized material levels or layers. The present study demonstrates that biologically inspired hierarchical designs can help improve the moderate properties of natural fiber polymer composites or biocomposites and allow them to compete with conventional materials for load-bearing applications. An overview of the mechanics concepts that allow hierarchical designs to achieve higher performance is presented, followed by observation and results from flexural tests on periodic and hierarchical cellular beams and plates made from industrial hemp fibers and unsaturated polyester resin biocomposites. The experimental data is shown to agree well with performance indices predicted by mechanics models. A procedure for the multi-scale integrated material/structural analysis of hierarchical cellular biocomposite components is presented and its advantages and limitations are discussed

Soil Structure Interaction Effect on High Rise and Low Rise Buildings

OpenAIRE

Divya Pathak; PAresh H. SHAH

2000-01-01

Effect of supporting soil on the response of structure has been analyzed in the present study. A low rise (G+ 5 storey) and a high rise (G+12 storey) building has been taken for the analysis. For both type of buildings, the response of building with and without consideration of soil structure interaction effect has been compared.Without interaction case is the case in which ends of the structure are assumed to be fixed while in interaction case, structure is assumed to be...

Adsorption-Induced Deformation of Hierarchically Structured Mesoporous Silica-Effect of Pore-Level Anisotropy.

Science.gov (United States)

Balzer, Christian; Waag, Anna M; Gehret, Stefan; Reichenauer, Gudrun; Putz, Florian; Hüsing, Nicola; Paris, Oskar; Bernstein, Noam; Gor, Gennady Y; Neimark, Alexander V

2017-06-06

The goal of this work is to understand adsorption-induced deformation of hierarchically structured porous silica exhibiting well-defined cylindrical mesopores. For this purpose, we performed an in situ dilatometry measurement on a calcined and sintered monolithic silica sample during the adsorption of N 2 at 77 K. To analyze the experimental data, we extended the adsorption stress model to account for the anisotropy of cylindrical mesopores, i.e., we explicitly derived the adsorption stress tensor components in the axial and radial direction of the pore. For quantitative predictions of stresses and strains, we applied the theoretical framework of Derjaguin, Broekhoff, and de Boer for adsorption in mesopores and two mechanical models of silica rods with axially aligned pore channels: an idealized cylindrical tube model, which can be described analytically, and an ordered hexagonal array of cylindrical mesopores, whose mechanical response to adsorption stress was evaluated by 3D finite element calculations. The adsorption-induced strains predicted by both mechanical models are in good quantitative agreement making the cylindrical tube the preferable model for adsorption-induced strains due to its simple analytical nature. The theoretical results are compared with the in situ dilatometry data on a hierarchically structured silica monolith composed by a network of mesoporous struts of MCM-41 type morphology. Analyzing the experimental adsorption and strain data with the proposed theoretical framework, we find the adsorption-induced deformation of the monolithic sample being reasonably described by a superposition of axial and radial strains calculated on the mesopore level. The structural and mechanical parameters obtained from the model are in good agreement with expectations from independent measurements and literature, respectively.

A mechanical model of biomimetic adhesive pads with tilted and hierarchical structures.

Science.gov (United States)

Schargott, M

2009-06-01

A 3D model for hierarchical biomimetic adhesive pads is constructed. It is based on the main principles of the adhesive pads of the Tokay gecko and consists of hierarchical layers of vertical or tilted beams, where each layer is constructed in such a way that no cohesion between adjacent beams can occur. The elastic and adhesive properties are calculated analytically and numerically. For the adhesive contact on stochastically rough surfaces, the maximum adhesion force increases with increasing number of hierarchical layers. Additional calculations show that the adhesion force also depends on the height spectrum of the rough surface.

A mechanical model of biomimetic adhesive pads with tilted and hierarchical structures

Energy Technology Data Exchange (ETDEWEB)

Schargott, M [Institute of Mechanics, Technische Universitaet Berlin, Strd 17 Juni 135, 10623 Berlin (Germany)], E-mail: martin.schargott@tu-berlin.de

2009-06-01

A 3D model for hierarchical biomimetic adhesive pads is constructed. It is based on the main principles of the adhesive pads of the Tokay gecko and consists of hierarchical layers of vertical or tilted beams, where each layer is constructed in such a way that no cohesion between adjacent beams can occur. The elastic and adhesive properties are calculated analytically and numerically. For the adhesive contact on stochastically rough surfaces, the maximum adhesion force increases with increasing number of hierarchical layers. Additional calculations show that the adhesion force also depends on the height spectrum of the rough surface.

A mechanical model of biomimetic adhesive pads with tilted and hierarchical structures

International Nuclear Information System (INIS)

Schargott, M

2009-01-01

A 3D model for hierarchical biomimetic adhesive pads is constructed. It is based on the main principles of the adhesive pads of the Tokay gecko and consists of hierarchical layers of vertical or tilted beams, where each layer is constructed in such a way that no cohesion between adjacent beams can occur. The elastic and adhesive properties are calculated analytically and numerically. For the adhesive contact on stochastically rough surfaces, the maximum adhesion force increases with increasing number of hierarchical layers. Additional calculations show that the adhesion force also depends on the height spectrum of the rough surface

A self-defining hierarchical data system

Science.gov (United States)

Bailey, J.

1992-01-01

The Self-Defining Data System (SDS) is a system which allows the creation of self-defining hierarchical data structures in a form which allows the data to be moved between different machine architectures. Because the structures are self-defining they can be used for communication between independent modules in a distributed system. Unlike disk-based hierarchical data systems such as Starlink's HDS, SDS works entirely in memory and is very fast. Data structures are created and manipulated as internal dynamic structures in memory managed by SDS itself. A structure may then be exported into a caller supplied memory buffer in a defined external format. This structure can be written as a file or sent as a message to another machine. It remains static in structure until it is reimported into SDS. SDS is written in portable C and has been run on a number of different machine architectures. Structures are portable between machines with SDS looking after conversion of byte order, floating point format, and alignment. A Fortran callable version is also available for some machines.

Facile synthesis and photocatalytic activity of zinc oxide hierarchical microcrystals

KAUST Repository

Xu, Xinjiang

2013-04-04

ZnO microcrystals with hierarchical structure have been synthesized by a simple solvothermal approach. The microcrystals were studied by means of X-ray diffraction, transmission electron microscopy, and scanning electron microscopy. Research on the formation mechanism of the hierarchical microstructure shows that the coordination solvent and precursor concentration have considerable influence on the size and morphology of the microstructures. A possible formation mechanism of the hierarchical structure was suggested. Furthermore, the catalytic activity of the ZnO microcrystals was studied by treating low concentration Rhodamine B (RhB) solution under UV light, and research results show the hierarchical microstructures of ZnO display high catalytic activity in photocatalysis, the catalysis process follows first-order reaction kinetics, and the apparent rate constant k = 0.03195 min-1.

Influence of geometry on mechanical properties of bio-inspired silica-based hierarchical materials

International Nuclear Information System (INIS)

Dimas, Leon S; Buehler, Markus J

2012-01-01

Diatoms, bone, nacre and deep-sea sponges are mineralized natural structures found abundantly in nature. They exhibit mechanical properties on par with advanced engineering materials, yet their fundamental building blocks are brittle and weak. An intriguing characteristic of these structures is their heterogeneous distribution of mechanical properties. Specifically, diatoms exhibit nanoscale porosity in specific geometrical configurations to create regions with distinct stress strain responses, notably based on a single and simple building block, silica. The study reported here, using models derived from first principles based full atomistic studies with the ReaxFF reactive force field, focuses on the mechanics and deformation mechanisms of silica-based nanocomposites inspired by mineralized structures. We examine single edged notched tensile specimens and analyze stress and strain fields under varied sample size in order to gain fundamental insights into the deformation mechanisms of structures with distinct ordered arrangements of soft and stiff phases. We find that hierarchical arrangements of silica nanostructures markedly change the stress and strain transfer in the samples. The combined action of strain transfer in the deformable phase, and stress transfer in the strong phase, acts synergistically to reduce the intensity of stress concentrations around a crack tip, and renders the resulting composites less sensitive to the presence of flaws, for certain geometrical configurations it even leads to stable crack propagation. A systematic study allows us to identify composite structures with superior fracture mechanical properties relative to their constituents, akin to many natural biomineralized materials that turn the weaknesses of building blocks into a strength of the overall system. (paper)

Hierarchically structured self-supported latex films for flexible and semi-transparent electronics

International Nuclear Information System (INIS)

Määttänen, Anni; Ihalainen, Petri; Törngren, Björn; Rosqvist, Emil; Pesonen, Markus; Peltonen, Jouko

2016-01-01

Graphical abstract: - Highlights: • Transparent self-supported latex films were fabricated by a peel-off process. • Various template substrates were used for creating e.g. hierarchically structured latex films. • Ultra-thin and semi-transparent conductive gold electrodes were evaporated on the latex films.Electrochemical experiments were carried out to verify the applicability of the electrodes. - Abstract: Different length scale alterations in topography, surface texture, and symmetry are known to evoke diverse cell behavior, including adhesion, orientation, motility, cytoskeletal condensation, and modulation of intracellular signaling pathways. In this work, self-supported latex films with well-defined isotropic/anisotropic surface features and hierarchical morphologies were fabricated by a peel-off process from different template surfaces. In addition, the latex films were used as substrates for evaporated ultrathin gold films with nominal thicknesses of 10 and 20 nm. Optical properties and topography of the samples were characterized using UV–vis spectroscopy and Atomic Force Microscopy (AFM) measurements, respectively. The latex films showed high-level transmittance of visible light, enabling the fabrication of semi-transparent gold electrodes. Electrochemical impedance spectroscopy (EIS) measurements were carried out for a number of days to investigate the long-term stability of the electrodes. The effect of 1-octadecanethiol (ODT) and HS(CH_2)_1_1OH (MuOH) thiolation and protein (human serum albumin, HSA) adsorption on the impedance and capacitance was studied. In addition, cyclic voltammetry (CV) measurements were carried out to determine active medicinal components, i.e., caffeic acid with interesting biological activities and poorly water-soluble anti-inflammatory drug, piroxicam. The results show that the fabrication procedure presented in this study enables the formation of platforms with hierarchical morphologies for multimodal (optical and

Hierarchically structured self-supported latex films for flexible and semi-transparent electronics

Energy Technology Data Exchange (ETDEWEB)

Määttänen, Anni, E-mail: anni.maattanen@abo.fi [Laboratory of Physical Chemistry, Faculty of Science and Engineering, Center for Functional Materials, Åbo Akademi University, Porthaninkatu 3, 20500, Turku (Finland); Ihalainen, Petri, E-mail: petri.ihalainen@abo.fi [Laboratory of Physical Chemistry, Faculty of Science and Engineering, Center for Functional Materials, Åbo Akademi University, Porthaninkatu 3, 20500, Turku (Finland); Törngren, Björn, E-mail: bjorn.torngren@abo.fi [Laboratory of Physical Chemistry, Faculty of Science and Engineering, Center for Functional Materials, Åbo Akademi University, Porthaninkatu 3, 20500, Turku (Finland); Rosqvist, Emil, E-mail: emil.rosqvist@abo.fi [Laboratory of Physical Chemistry, Faculty of Science and Engineering, Center for Functional Materials, Åbo Akademi University, Porthaninkatu 3, 20500, Turku (Finland); Pesonen, Markus, E-mail: markus.pesonen@abo.fi [Physics, Faculty of Science and Engineering, Center for Functional Materials, Åbo Akademi University, Porthaninkatu 3, 20500, Turku (Finland); Peltonen, Jouko, E-mail: jouko.peltonen@abo.fi [Laboratory of Physical Chemistry, Faculty of Science and Engineering, Center for Functional Materials, Åbo Akademi University, Porthaninkatu 3, 20500, Turku (Finland)

2016-02-28

Graphical abstract: - Highlights: • Transparent self-supported latex films were fabricated by a peel-off process. • Various template substrates were used for creating e.g. hierarchically structured latex films. • Ultra-thin and semi-transparent conductive gold electrodes were evaporated on the latex films.Electrochemical experiments were carried out to verify the applicability of the electrodes. - Abstract: Different length scale alterations in topography, surface texture, and symmetry are known to evoke diverse cell behavior, including adhesion, orientation, motility, cytoskeletal condensation, and modulation of intracellular signaling pathways. In this work, self-supported latex films with well-defined isotropic/anisotropic surface features and hierarchical morphologies were fabricated by a peel-off process from different template surfaces. In addition, the latex films were used as substrates for evaporated ultrathin gold films with nominal thicknesses of 10 and 20 nm. Optical properties and topography of the samples were characterized using UV–vis spectroscopy and Atomic Force Microscopy (AFM) measurements, respectively. The latex films showed high-level transmittance of visible light, enabling the fabrication of semi-transparent gold electrodes. Electrochemical impedance spectroscopy (EIS) measurements were carried out for a number of days to investigate the long-term stability of the electrodes. The effect of 1-octadecanethiol (ODT) and HS(CH{sub 2}){sub 11}OH (MuOH) thiolation and protein (human serum albumin, HSA) adsorption on the impedance and capacitance was studied. In addition, cyclic voltammetry (CV) measurements were carried out to determine active medicinal components, i.e., caffeic acid with interesting biological activities and poorly water-soluble anti-inflammatory drug, piroxicam. The results show that the fabrication procedure presented in this study enables the formation of platforms with hierarchical morphologies for multimodal

Adoption of Smart Structures for Prevention of Health Hazards in Buildings

Science.gov (United States)

Oke, Ayodeji; Aigbavboa, Clinton; Ngema, Wiseman

2017-11-01

The importance of building quality to the health and well-being of occupants and surrounding neighbors cannot be overemphasized. Smart structures were construed to proffer solution to various issues of sustainable development including social factors that is concerned with health and safety of people. Based on existing literature materials on building quality, smart structures and general aspect of sustainable developments, this study examined the benefits of smart structures in the prevention of various health issues in infrastructural buildings, which has been a concern for stakeholders in the architecture, engineering and construction industry. The criterion for indoor environmental quality was adopted and various health and bodily issues related to building quality were explained. The adoption of smart structure concept will help to manage physical, chemical, biological and psychological factors of building with a view to enhancing better quality of life of occupants.

Hierarchical analysis of acceptable use policies

Directory of Open Access Journals (Sweden)

P. A. Laughton

2008-01-01

Full Text Available Acceptable use policies (AUPs are vital tools for organizations to protect themselves and their employees from misuse of computer facilities provided. A well structured, thorough AUP is essential for any organization. It is impossible for an effective AUP to deal with every clause and remain readable. For this reason, some sections of an AUP carry more weight than others, denoting importance. The methodology used to develop the hierarchical analysis is a literature review, where various sources were consulted. This hierarchical approach to AUP analysis attempts to highlight important sections and clauses dealt with in an AUP. The emphasis of the hierarchal analysis is to prioritize the objectives of an AUP.

Deployable bamboo structure project: A building life-cycle report

Science.gov (United States)

Firdaus, Adrian; Prastyatama, Budianastas; Sagara, Altho; Wirabuana, Revian N.

2017-11-01

Bamboo is considered as a sustainable material in the world of construction, and it is vastly available in Indonesia. The general utilization of the material is increasingly frequent, however, its usage as a deployable structure-a recently-developed use of bamboo, is still untapped. This paper presents a report on a deployable bamboo structure project, covering the entire building life-cycle phase. The cycle encompasses the designing; fabrication; transportation; construction; operation and maintenance; as well as a plan for future re-use. The building is made of a configuration of the structural module, each being a folding set of bars which could be reduced in size to fit into vehicles for easy transportation. Each structural module was made of Gigantochloa apus bamboo. The fabrication, transportation, and construction phase require by a minimum of three workers. The fabrication and construction phase require three hours and fifteen minutes respectively. The building is utilized as cafeteria stands, the operation and maintenance phase started since early March 2017. The maintenance plan is scheduled on a monthly basis, focusing on the inspection of the locking mechanism element and the entire structural integrity. The building is designed to allow disassembly process so that it is reusable in the future.

Hierarchically structured distributed microprocessor network for control

International Nuclear Information System (INIS)

Greenwood, J.R.; Holloway, F.W.; Rupert, P.R.; Ozarski, R.G.; Suski, G.J.

1979-01-01

To satisfy a broad range of control-analysis and data-acquisition requirements for Shiva, a hierarchical, computer-based, modular-distributed control system was designed. This system handles the more than 3000 control elements and 1000 data acquisition units in a severe high-voltage, high-current environment. The control system design gives one a flexible and reliable configuration to meet the development milestones for Shiva within critical time limits

Hierarchical Design of Tissue Regenerative Constructs.

Science.gov (United States)

Rose, Jonas C; De Laporte, Laura

2018-03-01

The worldwide shortage of organs fosters significant advancements in regenerative therapies. Tissue engineering and regeneration aim to supply or repair organs or tissues by combining material scaffolds, biochemical signals, and cells. The greatest challenge entails the creation of a suitable implantable or injectable 3D macroenvironment and microenvironment to allow for ex vivo or in vivo cell-induced tissue formation. This review gives an overview of the essential components of tissue regenerating scaffolds, ranging from the molecular to the macroscopic scale in a hierarchical manner. Further, this review elaborates about recent pivotal technologies, such as photopatterning, electrospinning, 3D bioprinting, or the assembly of micrometer-scale building blocks, which enable the incorporation of local heterogeneities, similar to most native extracellular matrices. These methods are applied to mimic a vast number of different tissues, including cartilage, bone, nerves, muscle, heart, and blood vessels. Despite the tremendous progress that has been made in the last decade, it remains a hurdle to build biomaterial constructs in vitro or in vivo with a native-like structure and architecture, including spatiotemporal control of biofunctional domains and mechanical properties. New chemistries and assembly methods in water will be crucial to develop therapies that are clinically translatable and can evolve into organized and functional tissues. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Hierarchical temporal structure in music, speech and animal vocalizations: jazz is like a conversation, humpbacks sing like hermit thrushes.

Science.gov (United States)

Kello, Christopher T; Bella, Simone Dalla; Médé, Butovens; Balasubramaniam, Ramesh

2017-10-01

Humans talk, sing and play music. Some species of birds and whales sing long and complex songs. All these behaviours and sounds exhibit hierarchical structure-syllables and notes are positioned within words and musical phrases, words and motives in sentences and musical phrases, and so on. We developed a new method to measure and compare hierarchical temporal structures in speech, song and music. The method identifies temporal events as peaks in the sound amplitude envelope, and quantifies event clustering across a range of timescales using Allan factor (AF) variance. AF variances were analysed and compared for over 200 different recordings from more than 16 different categories of signals, including recordings of speech in different contexts and languages, musical compositions and performances from different genres. Non-human vocalizations from two bird species and two types of marine mammals were also analysed for comparison. The resulting patterns of AF variance across timescales were distinct to each of four natural categories of complex sound: speech, popular music, classical music and complex animal vocalizations. Comparisons within and across categories indicated that nested clustering in longer timescales was more prominent when prosodic variation was greater, and when sounds came from interactions among individuals, including interactions between speakers, musicians, and even killer whales. Nested clustering also was more prominent for music compared with speech, and reflected beat structure for popular music and self-similarity across timescales for classical music. In summary, hierarchical temporal structures reflect the behavioural and social processes underlying complex vocalizations and musical performances. © 2017 The Author(s).

Fabrication of hierarchically structured superhydrophobic PDMS surfaces by Cu and CuO casting

Science.gov (United States)

Migliaccio, Christopher P.; Lazarus, Nathan

2015-10-01

Poly(dimethylsiloxane) (PDMS) films decorated with hierarchically structured pillars are cast from large area copper and copper oxide negative molds. The molds are fabricated using a single patterning step and electroplating. The process of casting structured PDMS films is simpler and cheaper than alternatives based on deep reactive ion etching or laser roughening of bulk silicone. Texture imparted to the pillars from the mold walls renders the PDMS films superhydrophobic, with the contact angle/hysteresis of the most non-wetting surfaces measuring 164°/9° and 158°/10° for surfaces with and without application of a low surface energy coating. The usefulness of patterned PDMS films as a "self-cleaning" solar cell module covering is demonstrated and other applications are discussed.

Learning with hierarchical-deep models.

Science.gov (United States)

Salakhutdinov, Ruslan; Tenenbaum, Joshua B; Torralba, Antonio

2013-08-01

We introduce HD (or “Hierarchical-Deep”) models, a new compositional learning architecture that integrates deep learning models with structured hierarchical Bayesian (HB) models. Specifically, we show how we can learn a hierarchical Dirichlet process (HDP) prior over the activities of the top-level features in a deep Boltzmann machine (DBM). This compound HDP-DBM model learns to learn novel concepts from very few training example by learning low-level generic features, high-level features that capture correlations among low-level features, and a category hierarchy for sharing priors over the high-level features that are typical of different kinds of concepts. We present efficient learning and inference algorithms for the HDP-DBM model and show that it is able to learn new concepts from very few examples on CIFAR-100 object recognition, handwritten character recognition, and human motion capture datasets.

Deep hierarchical attention network for video description

Science.gov (United States)

Li, Shuohao; Tang, Min; Zhang, Jun

2018-03-01

Pairing video to natural language description remains a challenge in computer vision and machine translation. Inspired by image description, which uses an encoder-decoder model for reducing visual scene into a single sentence, we propose a deep hierarchical attention network for video description. The proposed model uses convolutional neural network (CNN) and bidirectional LSTM network as encoders while a hierarchical attention network is used as the decoder. Compared to encoder-decoder models used in video description, the bidirectional LSTM network can capture the temporal structure among video frames. Moreover, the hierarchical attention network has an advantage over single-layer attention network on global context modeling. To make a fair comparison with other methods, we evaluate the proposed architecture with different types of CNN structures and decoders. Experimental results on the standard datasets show that our model has a more superior performance than the state-of-the-art techniques.

Multiscale mechanics of hierarchical structure/property relationships in calcified tissues and tissue/material interfaces

International Nuclear Information System (INIS)

Katz, J. Lawrence; Misra, Anil; Spencer, Paulette; Wang, Yong; Bumrerraj, Sauwanan; Nomura, Tsutomu; Eppell, Steven J.; Tabib-Azar, Massood

2007-01-01

This paper presents a review plus new data that describes the role hierarchical nanostructural properties play in developing an understanding of the effect of scale on the material properties (chemical, elastic and electrical) of calcified tissues as well as the interfaces that form between such tissues and biomaterials. Both nanostructural and microstructural properties will be considered starting with the size and shape of the apatitic mineralites in both young and mature bovine bone. Microstructural properties for human dentin and cortical and trabecular bone will be considered. These separate sets of data will be combined mathematically to advance the effects of scale on the modeling of these tissues and the tissue/biomaterial interfaces as hierarchical material/structural composites. Interfacial structure and properties to be considered in greatest detail will be that of the dentin/adhesive (d/a) interface, which presents a clear example of examining all three material properties, (chemical, elastic and electrical). In this case, finite element modeling (FEA) was based on the actual measured values of the structure and elastic properties of the materials comprising the d/a interface; this combination provides insight into factors and mechanisms that contribute to premature failure of dental composite fillings. At present, there are more elastic property data obtained by microstructural measurements, especially high frequency ultrasonic wave propagation (UWP) and scanning acoustic microscopy (SAM) techniques. However, atomic force microscopy (AFM) and nanoindentation (NI) of cortical and trabecular bone and the dentin-enamel junction (DEJ) among others have become available allowing correlation of the nanostructural level measurements with those made on the microstructural level

Hierarchical structures consisting of SiO2 nanorods and p-GaN microdomes for efficiently harvesting solar energy for InGaN quantum well photovoltaic cells.

Science.gov (United States)

Ho, Cheng-Han; Lien, Der-Hsien; Chang, Hung-Chih; Lin, Chin-An; Kang, Chen-Fang; Hsing, Meng-Kai; Lai, Kun-Yu; He, Jr-Hau

2012-12-07

We experimentally and theoretically demonstrated the hierarchical structure of SiO(2) nanorod arrays/p-GaN microdomes as a light harvesting scheme for InGaN-based multiple quantum well solar cells. The combination of nano- and micro-structures leads to increased internal multiple reflection and provides an intermediate refractive index between air and GaN. Cells with the hierarchical structure exhibit improved short-circuit current densities and fill factors, rendering a 1.47 fold efficiency enhancement as compared to planar cells.

The Origin of Hierarchical Structure in Self-Assembled Graphene Oxide Papers and the Effect on Mechanical Properties

Science.gov (United States)

Nandy, Krishanu

The quest for new materials with ever improving properties has motivated interest in bulk nanostructured materials. Graphene, a two-dimensional sheet of hexagonally arranged carbon atoms, has been of particular interest given its exceptional mechanical, thermal, optical and electrical properties. Graphene oxide is a chemically modified form of graphene in which the honeycomb lattice of carbon atoms is decorated with oxygen bearing functional groups. Graphene oxide represents a facile route for the production of large quantities of graphene based materials, is stable in aqueous and polar organic solvents and has the potential for further chemical modification. In this dissertation, the origin and influence of hierarchical structure on the mechanical properties of graphene oxide paper and graphene oxide paper based materials has been investigated. Free-standing papers derived from graphene oxide are of interest as structural materials due to their impressive mechanical properties. While studies have investigated the mechanical properties of graphene oxide papers, little is known about the formation mechanism. Using a series of flash-freezing experiments on graphene oxide papers undergoing formation, a stop-motion animation of the fabrication process was obtained. The results explain the origin of the hierarchical nature of graphene oxide papers and provide a method for the tailoring of graphene oxide based materials. An in depth study of fusion of graphene oxide papers demonstrates a simple single-step route for the fabrication of practical materials derived from graphene oxide papers. Fused papers retain the properties of constituent papers allowing for the fabrication of mechanical heterostructures that replicate the hierarchical nature of natural materials. The contribution of the hierarchical nature of graphene oxide papers to the mechanical properties was examined by comparing papers formed by two different mechanisms. The intermediate length scale structures

Building with electromagnetic shield structure for individual floors

International Nuclear Information System (INIS)

Takahashi, T.; Nakamura, M.; Yabana, Y.; Ishikawa, T.; Nagata, K.

1991-01-01

This invention relates to a building having a floor-by-floor electromagnetic shield structure well-suited for application to an information network system in which an electromagnetically shielded space is divided by individual floors and electric waves are utilized within the building on a floor-by-floor basis. (author). 8 figs

Building with electromagnetic shield structure for individual floors

Energy Technology Data Exchange (ETDEWEB)

Takahashi, T; Nakamura, M; Yabana, Y; Ishikawa, T; Nagata, K

1991-09-10

This invention relates to a building having a floor-by-floor electromagnetic shield structure well-suited for application to an information network system in which an electromagnetically shielded space is divided by individual floors and electric waves are utilized within the building on a floor-by-floor basis. (author). 8 figs.

Probabilistic Assessment of Structural Seismic Damage for Buildings in Mid-America

International Nuclear Information System (INIS)

Bai, Jong-Wha; Hueste, Mary Beth D.; Gardoni, Paolo

2008-01-01

This paper provides an approach to conduct a probabilistic assessment of structural damage due to seismic events with an application to typical building structures in Mid-America. The developed methodology includes modified damage state classifications based on the ATC-13 and ATC-38 damage states and the ATC-38 database of building damage. Damage factors are assigned to each damage state to quantify structural damage as a percentage of structural replacement cost. To account for the inherent uncertainties, these factors are expressed as random variables with a Beta distribution. A set of fragility curves, quantifying the structural vulnerability of a building, is mapped onto the developed methodology to determine the expected structural damage. The total structural damage factor for a given seismic intensity is then calculated using a probabilistic approach. Prediction and confidence bands are also constructed to account for the prevailing uncertainties. The expected seismic structural damage is assessed for a typical building structure in the Mid-America region using the developed methodology. The developed methodology provides a transparent procedure, where the structural damage factors can be updated as additional seismic damage data becomes available

Effect of structural design on traffic-induced building vibrations

DEFF Research Database (Denmark)

Persson, Peter; Andersen, Lars Vabbersgaard; Persson, Kent

2017-01-01

Population growth and urbanization results in densified cities, where new buildings are being built closer to existing vibration sources such as road-, tram- and rail traffic. In addition, new transportation systems are constructed closer to existing buildings. Potential disturbing vibrations...... are one issue to consider in planning urban environment and densification of cities. Vibrations can be disturbing for humans but also for sensitive equipment in, for example, hospitals. In determining the risk for disturbing vibrations, the distance between the source and the receiver, the ground...... properties, and type and size of the building are governing factors. In the paper, a study is presented aiming at investigating the influence of various parameters of the building's structural design on vibration levels in the structure caused by ground surface loads, e.g. traffic. Parameters studied...

TiO2 nanowire-templated hierarchical nanowire network as water-repelling coating

Science.gov (United States)

Hang, Tian; Chen, Hui-Jiuan; Xiao, Shuai; Yang, Chengduan; Chen, Meiwan; Tao, Jun; Shieh, Han-ping; Yang, Bo-ru; Liu, Chuan; Xie, Xi

2017-12-01

Extraordinary water-repelling properties of superhydrophobic surfaces make them novel candidates for a great variety of potential applications. A general approach to achieve superhydrophobicity requires low-energy coating on the surface and roughness on nano- and micrometre scale. However, typical construction of superhydrophobic surfaces with micro-nano structure through top-down fabrication is restricted by sophisticated fabrication techniques and limited choices of substrate materials. Micro-nanoscale topographies templated by conventional microparticles through surface coating may produce large variations in roughness and uncontrollable defects, resulting in poorly controlled surface morphology and wettability. In this work, micro-nanoscale hierarchical nanowire network was fabricated to construct self-cleaning coating using one-dimensional TiO2 nanowires as microscale templates. Hierarchical structure with homogeneous morphology was achieved by branching ZnO nanowires on the TiO2 nanowire backbones through hydrothermal reaction. The hierarchical nanowire network displayed homogeneous micro/nano-topography, in contrast to hierarchical structure templated by traditional microparticles. This hierarchical nanowire network film exhibited high repellency to both water and cell culture medium after functionalization with fluorinated organic molecules. The hierarchical structure templated by TiO2 nanowire coating significantly increased the surface superhydrophobicity compared to vertical ZnO nanowires with nanotopography alone. Our results demonstrated a promising strategy of using nanowires as microscale templates for the rational design of hierarchical coatings with desired superhydrophobicity that can also be applied to various substrate materials.

Hierarchical columnar silicon anode structures for high energy density lithium sulfur batteries

Science.gov (United States)

Piwko, Markus; Kuntze, Thomas; Winkler, Sebastian; Straach, Steffen; Härtel, Paul; Althues, Holger; Kaskel, Stefan

2017-05-01

Silicon is a promising anode material for next generation lithium secondary batteries. To significantly increase the energy density of state of the art batteries with silicon, new concepts have to be developed and electrode structuring will become a key technology. Structuring is essential to reduce the macroscopic and microscopic electrode deformation, caused by the volume change during cycling. We report pulsed laser structuring for the generation of hierarchical columnar silicon films with outstanding high areal capacities up to 7.5 mAh cm-2 and good capacity retention. Unstructured columnar electrodes form a micron-sized block structure during the first cycle to compensate the volume expansion leading to macroscopic electrode deformation. At increased silicon loading, without additional structuring, pronounced distortion and the formation of cracks through the current collector causes cell failure. Pulsed laser ablation instead is demonstrated to avoid macroscopic electrode deformation by initial formation of the block structure. A full cell with lithiated silicon versus a carbon-sulfur cathode is assembled with only 15% overbalanced anode and low electrolyte amount (8 μl mgsulfur-1). While the capacity retention over 50 cycles is identical to a cell with high excess lithium anode, the volumetric energy density could be increased by 30%.

Interactive computer graphics displays for hierarchical data structures

International Nuclear Information System (INIS)

Cahn, D.F.; Murano, C.V.

1980-05-01

An interactive computer graphical display program was developed as an aid to user visualization and manipulation of hierarchically structured data systems such as thesauri. In the present configuration, a thesaurus term and its primary and secondary conceptual neighbors are presented to the user in tree graph form on a CRT; the user then designates, via light pen or keyboard, any of the neighbors as the next term of interest and receives a new display centered on this term. By successive specification of broader, narrower, and related terms, the user can course rapidly through the thesaurus space and refine his search file. At any stage, he deals with a term-centered, conceptually meaningful picture of a localized portion of the thesaurus, and is freed from the artificial difficulties of handling the traditional alphabetized thesaurus. Intentional limitation of the associative range of each display frame, and the use of color, case, and interconnecting vectors to encode relationships among terms, enhance interpretability of the display. Facile movement through the term space, provided by interactive computation, allows the display to remain simple, and is an essential element of the system. 3 figures

The contribution of reinforcement sensitivity to the personality-psychopathology hierarchical structure in childhood and adolescence.

Science.gov (United States)

Slobodskaya, Helena R

2016-11-01

This study examined the contribution of reinforcement sensitivity to the hierarchical structure of child personality and common psychopathology in community samples of parent reports of children aged 2-18 (N = 968) and self-reports of adolescents aged 10-18 (N = 1,543) using the Inventory of Child Individual Differences-Short version (ICID-S), the Strengths and Difficulties Questionnaire (SDQ), and the Sensitivity to Punishment and Sensitivity to Reward Questionnaire (SPSRQ). A joint higher-order factor analysis of the ICID-S and SDQ scales suggested a 4-factor solution; congruence coefficients indicated replicability of the factors across the 2 samples at all levels of the personality-psychopathology hierarchy. The canonical correlation analyses indicated that reinforcement sensitivity and personality-psychopathology dimensions shared much of their variance. The main contribution of reinforcement sensitivity was through opposing effects of reward and punishment sensitivities. The superordinate factors Beta and Internalizing were best predicted by reinforcement sensitivity, followed by the Externalizing and Positive personality factors. These findings provide evidence for consistency of the hierarchical structure of personality and common psychopathology across informants and highlight the role of reinforcement systems in the development of normal and abnormal patterns of behavior and affect. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Hierarchically Organized Behavior and Its Neural Foundations: A Reinforcement Learning Perspective

Science.gov (United States)

Botvinick, Matthew M.; Niv, Yael; Barto, Andrew C.

2009-01-01

Research on human and animal behavior has long emphasized its hierarchical structure--the divisibility of ongoing behavior into discrete tasks, which are comprised of subtask sequences, which in turn are built of simple actions. The hierarchical structure of behavior has also been of enduring interest within neuroscience, where it has been widely…

Hierarchical Recurrent Neural Hashing for Image Retrieval With Hierarchical Convolutional Features.

Science.gov (United States)

Lu, Xiaoqiang; Chen, Yaxiong; Li, Xuelong

Hashing has been an important and effective technology in image retrieval due to its computational efficiency and fast search speed. The traditional hashing methods usually learn hash functions to obtain binary codes by exploiting hand-crafted features, which cannot optimally represent the information of the sample. Recently, deep learning methods can achieve better performance, since deep learning architectures can learn more effective image representation features. However, these methods only use semantic features to generate hash codes by shallow projection but ignore texture details. In this paper, we proposed a novel hashing method, namely hierarchical recurrent neural hashing (HRNH), to exploit hierarchical recurrent neural network to generate effective hash codes. There are three contributions of this paper. First, a deep hashing method is proposed to extensively exploit both spatial details and semantic information, in which, we leverage hierarchical convolutional features to construct image pyramid representation. Second, our proposed deep network can exploit directly convolutional feature maps as input to preserve the spatial structure of convolutional feature maps. Finally, we propose a new loss function that considers the quantization error of binarizing the continuous embeddings into the discrete binary codes, and simultaneously maintains the semantic similarity and balanceable property of hash codes. Experimental results on four widely used data sets demonstrate that the proposed HRNH can achieve superior performance over other state-of-the-art hashing methods.Hashing has been an important and effective technology in image retrieval due to its computational efficiency and fast search speed. The traditional hashing methods usually learn hash functions to obtain binary codes by exploiting hand-crafted features, which cannot optimally represent the information of the sample. Recently, deep learning methods can achieve better performance, since deep

Decentralized Networked Control of Building Structures

Czech Academy of Sciences Publication Activity Database

Bakule, Lubomír; Rehák, Branislav; Papík, Martin

2016-01-01

Roč. 31, č. 11 (2016), s. 871-886 ISSN 1093-9687 R&D Projects: GA ČR GA13-02149S Institutional support: RVO:67985556 Keywords : decentralized control * networked control * building structures Subject RIV: BC - Control Systems Theory Impact factor: 5.786, year: 2016

3D hierarchically porous Cu-BiOCl nanocomposite films: one-step electrochemical synthesis, structural characterization and nanomechanical and photoluminescent properties

Science.gov (United States)

Guerrero, Miguel; Pané, Salvador; Nelson, Bradley J.; Baró, Maria Dolors; Roldán, Mònica; Sort, Jordi; Pellicer, Eva

2013-11-01

Three-dimensional (3D) hierarchically porous composite Cu-BiOCl films have been prepared by a facile one-step galvanostatic electrodeposition process from acidic electrolytic solutions containing Cu(ii) and Bi(iii) chloride salts and Triton X-100. The films show spherical, micron-sized pores that spread over the whole film thickness. In turn, the pore walls are made of randomly packed BiOCl nanoplates that are assembled leaving micro-nanopore voids beneath. It is believed that Cu grows within the interstitial spaces between the hydrogen bubbles produced from the reduction of H+ ions. Then, the BiOCl sheets accommodate in the porous network defined by the Cu building blocks. The presence of Cu tends to enhance the mechanical stability of the composite material. The resulting porous Cu-BiOCl films exhibit homogeneous and stable-in-time photoluminescent response arising from the BiOCl component that spreads over the entire 3D porous structure, as demonstrated by confocal scanning laser microscopy. A broad-band emission covering the entire visible range, in the wavelength interval 450-750 nm, is obtained. The present work paves the way for the facile and controlled preparation of a new generation of photoluminescent membranes.Three-dimensional (3D) hierarchically porous composite Cu-BiOCl films have been prepared by a facile one-step galvanostatic electrodeposition process from acidic electrolytic solutions containing Cu(ii) and Bi(iii) chloride salts and Triton X-100. The films show spherical, micron-sized pores that spread over the whole film thickness. In turn, the pore walls are made of randomly packed BiOCl nanoplates that are assembled leaving micro-nanopore voids beneath. It is believed that Cu grows within the interstitial spaces between the hydrogen bubbles produced from the reduction of H+ ions. Then, the BiOCl sheets accommodate in the porous network defined by the Cu building blocks. The presence of Cu tends to enhance the mechanical stability of the

Superhydrophobic hierarchically structured surfaces in biology: evolution, structural principles and biomimetic applications.

Science.gov (United States)

Barthlott, W; Mail, M; Neinhuis, C

2016-08-06

A comprehensive survey of the construction principles and occurrences of superhydrophobic surfaces in plants, animals and other organisms is provided and is based on our own scanning electron microscopic examinations of almost 20 000 different species and the existing literature. Properties such as self-cleaning (lotus effect), fluid drag reduction (Salvinia effect) and the introduction of new functions (air layers as sensory systems) are described and biomimetic applications are discussed: self-cleaning is established, drag reduction becomes increasingly important, and novel air-retaining grid technology is introduced. Surprisingly, no evidence for lasting superhydrophobicity in non-biological surfaces exists (except technical materials). Phylogenetic trees indicate that superhydrophobicity evolved as a consequence of the conquest of land about 450 million years ago and may be a key innovation in the evolution of terrestrial life. The approximate 10 million extant species exhibit a stunning diversity of materials and structures, many of which are formed by self-assembly, and are solely based on a limited number of molecules. A short historical survey shows that bionics (today often called biomimetics) dates back more than 100 years. Statistical data illustrate that the interest in biomimetic surfaces is much younger still. Superhydrophobicity caught the attention of scientists only after the extreme superhydrophobicity of lotus leaves was published in 1997. Regrettably, parabionic products play an increasing role in marketing.This article is part of the themed issue 'Bioinspired hierarchically structured surfaces for green science'. © 2016 The Author(s).

Superhydrophobic hierarchically structured surfaces in biology: evolution, structural principles and biomimetic applications

Science.gov (United States)

Mail, M.; Neinhuis, C.

2016-01-01

A comprehensive survey of the construction principles and occurrences of superhydrophobic surfaces in plants, animals and other organisms is provided and is based on our own scanning electron microscopic examinations of almost 20 000 different species and the existing literature. Properties such as self-cleaning (lotus effect), fluid drag reduction (Salvinia effect) and the introduction of new functions (air layers as sensory systems) are described and biomimetic applications are discussed: self-cleaning is established, drag reduction becomes increasingly important, and novel air-retaining grid technology is introduced. Surprisingly, no evidence for lasting superhydrophobicity in non-biological surfaces exists (except technical materials). Phylogenetic trees indicate that superhydrophobicity evolved as a consequence of the conquest of land about 450 million years ago and may be a key innovation in the evolution of terrestrial life. The approximate 10 million extant species exhibit a stunning diversity of materials and structures, many of which are formed by self-assembly, and are solely based on a limited number of molecules. A short historical survey shows that bionics (today often called biomimetics) dates back more than 100 years. Statistical data illustrate that the interest in biomimetic surfaces is much younger still. Superhydrophobicity caught the attention of scientists only after the extreme superhydrophobicity of lotus leaves was published in 1997. Regrettably, parabionic products play an increasing role in marketing. This article is part of the themed issue ‘Bioinspired hierarchically structured surfaces for green science’. PMID:27354736

Synthesis of vibration control and health monitoring of building structures under unknown excitation

International Nuclear Information System (INIS)

He, Jia; Huang, Qin; Xu, You-Lin

2014-01-01

The vibration control and health monitoring of building structures have been actively investigated in recent years but often treated separately according to the primary objective pursued. In this study, a time-domain integrated vibration control and health monitoring approach is proposed based on the extended Kalman filter (EKF) for identifying the physical parameters of the controlled building structures without the knowledge of the external excitation. The physical parameters and state vectors of the building structure are then estimated and used for the determination of the control force for the purpose of the vibration attenuation. The interaction between the health monitoring and vibration control is revealed and assessed. The feasibility and reliability of the proposed approach is numerically demonstrated via a five-story shear building structure equipped with magneto-rheological (MR) dampers. Two types of excitations are considered: (1) the EI-Centro ground excitation underneath of the building and (2) a swept-frequency excitation applied on the top floor of the building. Results show that the structural parameters as well as the unknown dynamic loadings could be identified accurately; and, at the same time, the structural vibration is significantly reduced in the building structure. (paper)

A Graph-Based Approach for 3D Building Model Reconstruction from Airborne LiDAR Point Clouds

Directory of Open Access Journals (Sweden)

Bin Wu

2017-01-01

Full Text Available 3D building model reconstruction is of great importance for environmental and urban applications. Airborne light detection and ranging (LiDAR is a very useful data source for acquiring detailed geometric and topological information of building objects. In this study, we employed a graph-based method based on hierarchical structure analysis of building contours derived from LiDAR data to reconstruct urban building models. The proposed approach first uses a graph theory-based localized contour tree method to represent the topological structure of buildings, then separates the buildings into different parts by analyzing their topological relationships, and finally reconstructs the building model by integrating all the individual models established through the bipartite graph matching process. Our approach provides a more complete topological and geometrical description of building contours than existing approaches. We evaluated the proposed method by applying it to the Lujiazui region in Shanghai, China, a complex and large urban scene with various types of buildings. The results revealed that complex buildings could be reconstructed successfully with a mean modeling error of 0.32 m. Our proposed method offers a promising solution for 3D building model reconstruction from airborne LiDAR point clouds.

KEY ASPECTS OF ENSURING ENERGY EFFICIENCY OF BUILDINGS AND STRUCTURES

Directory of Open Access Journals (Sweden)

S.G. Abramyan

2017-06-01

Full Text Available The paper is based on the review of the foreign and national academic literature and intended to emphasize the issues of ensuring energy efficiency of buildings and structures applicable to all the countries as for reconstruction of existing buildings as for erection of new ones . The author highlights the key aspects of the provision of energy efficiency of buildings and structures in some foreign countries. The conclusion is made that the studies are mainly aimed at discovering new heat insulation materials, whereby polystyrene insulation is found to be the most widespread wall insulation material in a number of countries. At the same time, it is observed that the ongoing research is focused on solutions to optimize the structure of walling systems in terms of both insulant thickness and the number and sequence of insulation layers in the walling structure. A conclusion is made that hyper insulation of external walls leads to considerable expenses arising due to cooling during the summer season. The use of prefabricated vacuum panels as a heat insulation layer and off-the-shelf single-layer structures, subject to their heat insulation characteristics, appears a more constructive way to meet the energy efficiency requirements, as the arrangement of ideal air space in multilayered walls proves a significant challenge today. One of the most promising ways to ensure energy efficiency is the use of multifunctional polyvalent walls and provision of polyvalent heat supply from renewable energy sources. Since energy efficiency depends on the spatial arrangement of buildings, construction must ensure a minimum ratio of the area of enclosing structures to the overall building volume (by adding on new facilities in case of reconstruction. It is noted that a systemic approach to ensuring energy efficiency of buildings is impossible without proper regard to the environmental parameters of heat insulation materials.

Leadership styles across hierarchical levels in nursing departments.

Science.gov (United States)

Stordeur, S; Vandenberghe, C; D'hoore, W

2000-01-01

Some researchers have reported on the cascading effect of transformational leadership across hierarchical levels. One study examined this effect in nursing, but it was limited to a single hospital. To examine the cascading effect of leadership styles across hierarchical levels in a sample of nursing departments and to investigate the effect of hierarchical level on the relationships between leadership styles and various work outcomes. Based on a sample of eight hospitals, the cascading effect was tested using correlation analysis. The main sources of variation among leadership scores were determined with analyses of variance (ANOVA), and the interaction effect of hierarchical level and leadership styles on criterion variables was tested with moderated regression analysis. No support was found for a cascading effect of leadership across hierarchical levels. Rather, the variation of leadership scores was explained primarily by the organizational context. Transformational leadership had a stronger impact on criterion variables than transactional leadership. Interaction effects between leadership styles and hierarchical level were observed only for perceived unit effectiveness. The hospital's structure and culture are major determinants of leadership styles.

Multifaceted Modularity: A Key for Stepwise Building of Hierarchical Complexity in Actinide Metal–Organic Frameworks

Energy Technology Data Exchange (ETDEWEB)

Dolgopolova, Ekaterina A. [Department; Ejegbavwo, Otega A. [Department; Martin, Corey R. [Department; Smith, Mark D. [Department; Setyawan, Wahyu [Pacific Northwest National Laboratory, Richland, Washington 99352, United States; Karakalos, Stavros G. [College; Henager, Charles H. [Pacific Northwest National Laboratory, Richland, Washington 99352, United States; zur Loye, Hans-Conrad [Department; Shustova, Natalia B. [Department

2017-11-07

Growing necessity for efficient nuclear waste management is a driving force for development of alternative architectures towards fundamental understanding of mechanisms involved in actinide integration inside extended structures. In this manuscript, metal-organic frameworks (MOFs) were investigated as a model system for engineering radionuclide containing materials through utilization of unprecedented MOF modularity, which cannot be replicated in any other type of materials. Through the implementation of recent synthetic advances in the MOF field, hierarchical complexity of An-materials were built stepwise, which was only feasible due to preparation of the first examples of actinide-based frameworks with “unsaturated” metal nodes. The first successful attempts of solid-state metathesis and metal node extension in An-MOFs are reported, and the results of the former approach revealed drastic differences in chemical behavior of extended structures versus molecular species. Successful utilization of MOF modularity also allowed us to structurally characterize the first example of bimetallic An-An nodes. To the best of our knowledge, through combination of solid-state metathesis, guest incorporation, and capping linker installation, we were able to achieve the highest Th wt% in mono- and bi-actinide frameworks with minimal structural density. Overall, combination of a multistep synthetic approach with homogeneous actinide distribution and moderate solvothermal conditions could make MOFs an exceptionally powerful tool to address fundamental questions responsible for chemical behavior of An-based extended structures, and therefore, shed light on possible optimization of nuclear waste administration.

Bottom-up GGM algorithm for constructing multiple layered hierarchical gene regulatory networks

Science.gov (United States)

Multilayered hierarchical gene regulatory networks (ML-hGRNs) are very important for understanding genetics regulation of biological pathways. However, there are currently no computational algorithms available for directly building ML-hGRNs that regulate biological pathways. A bottom-up graphic Gaus...

A hierarchical structure approach to MultiSensor Information Fusion

Energy Technology Data Exchange (ETDEWEB)

Maren, A.J. (Tennessee Univ., Tullahoma, TN (United States). Space Inst.); Pap, R.M.; Harston, C.T. (Accurate Automation Corp., Chattanooga, TN (United States))

1989-01-01

A major problem with image-based MultiSensor Information Fusion (MSIF) is establishing the level of processing at which information should be fused. Current methodologies, whether based on fusion at the pixel, segment/feature, or symbolic levels, are each inadequate for robust MSIF. Pixel-level fusion has problems with coregistration of the images or data. Attempts to fuse information using the features of segmented images or data relies an a presumed similarity between the segmentation characteristics of each image or data stream. Symbolic-level fusion requires too much advance processing to be useful, as we have seen in automatic target recognition tasks. Image-based MSIF systems need to operate in real-time, must perform fusion using a variety of sensor types, and should be effective across a wide range of operating conditions or deployment environments. We address this problem through developing a new representation level which facilitates matching and information fusion. The Hierarchical Scene Structure (HSS) representation, created using a multilayer, cooperative/competitive neural network, meets this need. The MSS is intermediate between a pixel-based representation and a scene interpretation representation, and represents the perceptual organization of an image. Fused HSSs will incorporate information from multiple sensors. Their knowledge-rich structure aids top-down scene interpretation via both model matching and knowledge-based,region interpretation.

A hierarchical structure approach to MultiSensor Information Fusion

Energy Technology Data Exchange (ETDEWEB)

Maren, A.J. [Tennessee Univ., Tullahoma, TN (United States). Space Inst.; Pap, R.M.; Harston, C.T. [Accurate Automation Corp., Chattanooga, TN (United States)

1989-12-31

A major problem with image-based MultiSensor Information Fusion (MSIF) is establishing the level of processing at which information should be fused. Current methodologies, whether based on fusion at the pixel, segment/feature, or symbolic levels, are each inadequate for robust MSIF. Pixel-level fusion has problems with coregistration of the images or data. Attempts to fuse information using the features of segmented images or data relies an a presumed similarity between the segmentation characteristics of each image or data stream. Symbolic-level fusion requires too much advance processing to be useful, as we have seen in automatic target recognition tasks. Image-based MSIF systems need to operate in real-time, must perform fusion using a variety of sensor types, and should be effective across a wide range of operating conditions or deployment environments. We address this problem through developing a new representation level which facilitates matching and information fusion. The Hierarchical Scene Structure (HSS) representation, created using a multilayer, cooperative/competitive neural network, meets this need. The MSS is intermediate between a pixel-based representation and a scene interpretation representation, and represents the perceptual organization of an image. Fused HSSs will incorporate information from multiple sensors. Their knowledge-rich structure aids top-down scene interpretation via both model matching and knowledge-based,region interpretation.

Ionothermal synthesis of hierarchical BiOBr microspheres for water treatment

Energy Technology Data Exchange (ETDEWEB)

Zhang, Dieqing [The Education Ministry Key Lab of Resource Chemistry and Shanghai Key Laboratory of Rare Earth Functional Materials, Shanghai Normal University, 100 Guilin Road, Shanghai 200231 (China); Department of Chemistry and Institute of Environment, Energy and Sustainability, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong (China); Wen, Meicheng; Jiang, Bo; Li, Guisheng [The Education Ministry Key Lab of Resource Chemistry and Shanghai Key Laboratory of Rare Earth Functional Materials, Shanghai Normal University, 100 Guilin Road, Shanghai 200231 (China); Yu, Jimmy C., E-mail: jimyu@cuhk.edu.hk [Department of Chemistry and Institute of Environment, Energy and Sustainability, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong (China)

2012-04-15

Graphical abstract: Hierarchical BiOBr microspheres were prepared from a bromine-containing ionic liquid. The material was found effective for removing heavy metals, degrading organic pollutants and killing bacteria. Highlight: Black-Right-Pointing-Pointer Ionothermal synthesis of BiOBr microspheres with hierarchical structure. Black-Right-Pointing-Pointer Efficient mass transfer and excellent light-harvesting ability. Black-Right-Pointing-Pointer Suitable for removing heavy metals and treatment of organic dyes. Black-Right-Pointing-Pointer Remarkable photocatalytic bactericidal property. - Abstract: Bismuth oxybromide (BiOBr) micropsheres with hierarchical morphologies have been fabricated via an ionothermal synthesis route. Ionic liquid acts as a unique soft material capable of promoting nucleation and in situ growth of 3D hierarchical BiOBr mesocrystals without the help of surfactants. The as-prepared BiOBr nanomaterials can effectively remove heavy metal ions and organic dyes from wastewater. They can also kill Micrococcus lylae, a Gram positive bacterium, in water under fluorescent light irradiation. Their high adaptability in water treatment may be ascribed to their hierarchical structure, allowing them high surface to volume ratio, facile species transportation and excellent light-harvesting ability.

Ionothermal synthesis of hierarchical BiOBr microspheres for water treatment

International Nuclear Information System (INIS)

Zhang, Dieqing; Wen, Meicheng; Jiang, Bo; Li, Guisheng; Yu, Jimmy C.

2012-01-01

Graphical abstract: Hierarchical BiOBr microspheres were prepared from a bromine-containing ionic liquid. The material was found effective for removing heavy metals, degrading organic pollutants and killing bacteria. Highlight: ► Ionothermal synthesis of BiOBr microspheres with hierarchical structure. ► Efficient mass transfer and excellent light-harvesting ability. ► Suitable for removing heavy metals and treatment of organic dyes. ► Remarkable photocatalytic bactericidal property. - Abstract: Bismuth oxybromide (BiOBr) micropsheres with hierarchical morphologies have been fabricated via an ionothermal synthesis route. Ionic liquid acts as a unique soft material capable of promoting nucleation and in situ growth of 3D hierarchical BiOBr mesocrystals without the help of surfactants. The as-prepared BiOBr nanomaterials can effectively remove heavy metal ions and organic dyes from wastewater. They can also kill Micrococcus lylae, a Gram positive bacterium, in water under fluorescent light irradiation. Their high adaptability in water treatment may be ascribed to their hierarchical structure, allowing them high surface to volume ratio, facile species transportation and excellent light-harvesting ability.

The fundamentals of structural building codes

NARCIS (Netherlands)

Vrouwenvelder, A.C.W.M.

2001-01-01

Partial Factor Design is nowadays a generally accepted design method for building and civil engineering structures. For most engineers the general philosophy that the safety factors depend on the type of the load and on the limit state under consideration makes sense. However, the background, in

High performance natural rubber composites with a hierarchical reinforcement structure of carbon nanotube modified natural fibers

International Nuclear Information System (INIS)

Tzounis, Lazaros; Debnath, Subhas; Rooj, Sandip; Fischer, Dieter; Mäder, Edith; Das, Amit; Stamm, Manfred; Heinrich, Gert

2014-01-01

A simple and facile method for depositing multiwall carbon nanotubes (MWCNTs) onto the surface of naturally occurring short jute fibers (JFs) is reported. Hierarchical multi-scale structures were formed with CNT-networks uniformly distributed and fully covering the JFs (JF–CNT), as depicted by the scanning electron microscopy (SEM) micrographs. The impact of these hybrid fillers on the mechanical properties of a natural rubber (NR) matrix was systematically investigated. Pristine JFs were cut initially to an average length of 2.0 mm and exposed to an alkali treatment (a-JFs) to remove impurities existing in the raw jute. MWCNTs were treated under mild acidic conditions to generate carboxylic acid moieties. Afterward, MWCNTs were dispersed in an aqueous media and short a-JFs were allowed to react with them. Raman spectroscopy confirmed the chemical interaction between CNTs and JFs. The JF–CNT exposed quite hydrophobic behavior as revealed by the water contact angle measurements, improving the wettability of the non-polar NR. Consequently, the composite interfacial adhesion strength was significantly enhanced while a micro-scale “mechanical interlocking” mechanism was observed from the interphase-section transmission electron microscopy (TEM) images. SEM analysis of the composite fracture surfaces demonstrated the interfacial strength of NR/a-JF and NR/JF–CNT composites, at different fiber loadings. It can be presumed that the CNT-coating effectively compatibillized the composite structure acting as a macromolecular coupling agent. A detailed analysis of stress-strain and dynamic mechanical spectra confirmed the high mechanical performance of the hierarchical composites, consisting mainly of materials arising from natural resources. - Highlights: • Natural rubber (NR) composites reinforced with CNT-modified short jute fibers. • MWCNTs deposited to the surface of jute fibers via non-covalent interactions. • Hierarchical reinforcement structure with

Context updates are hierarchical

Directory of Open Access Journals (Sweden)

Anton Karl Ingason

2016-10-01

Full Text Available This squib studies the order in which elements are added to the shared context of interlocutors in a conversation. It focuses on context updates within one hierarchical structure and argues that structurally higher elements are entered into the context before lower elements, even if the structurally higher elements are pronounced after the lower elements. The crucial data are drawn from a comparison of relative clauses in two head-initial languages, English and Icelandic, and two head-final languages, Korean and Japanese. The findings have consequences for any theory of a dynamic semantics.

From Nano to Macro: Studying the Hierarchical Structure of the Corneal Extracellular Matrix

Science.gov (United States)

Quantock, Andrew J.; Winkler, Moritz; Parfitt, Geraint J.; Young, Robert D.; Brown, Donald J.; Boote, Craig; Jester, James V.

2014-01-01

In this review, we discuss current methods for studying ocular extracellular matrix (ECM) assembly from the ‘nano’ to the ‘macro’ levels of hierarchical organization. Since collagen is the major structural protein in the eye, providing mechanical strength and controlling ocular shape, the methods presented focus on understanding the molecular assembly of collagen at the nanometer level using x-ray scattering through to the millimeter to centimeter level using nonlinear optical (NLO) imaging of second harmonic generated (SHG) signals. Three-dimensional analysis of ECM structure is also discussed, including electron tomography, serial block face scanning electron microscopy (SBF-SEM) and digital image reconstruction. Techniques to detect non-collagenous structural components of the ECM are also presented, and these include immunoelectron microscopy and staining with cationic dyes. Together, these various approaches are providing new insights into the structural blueprint of the ocular ECM, and in particular that of the cornea, which impacts upon our current understanding of the control of corneal shape, pathogenic mechanisms underlying ectatic disorders of the cornea and the potential for corneal tissue engineering. PMID:25819457

Hierarchical mixture of experts and diagnostic modeling approach to reduce hydrologic model structural uncertainty: STRUCTURAL UNCERTAINTY DIAGNOSTICS

Energy Technology Data Exchange (ETDEWEB)

Moges, Edom [Civil and Environmental Engineering Department, Washington State University, Richland Washington USA; Demissie, Yonas [Civil and Environmental Engineering Department, Washington State University, Richland Washington USA; Li, Hong-Yi [Hydrology Group, Pacific Northwest National Laboratory, Richland Washington USA

2016-04-01

In most water resources applications, a single model structure might be inadequate to capture the dynamic multi-scale interactions among different hydrological processes. Calibrating single models for dynamic catchments, where multiple dominant processes exist, can result in displacement of errors from structure to parameters, which in turn leads to over-correction and biased predictions. An alternative to a single model structure is to develop local expert structures that are effective in representing the dominant components of the hydrologic process and adaptively integrate them based on an indicator variable. In this study, the Hierarchical Mixture of Experts (HME) framework is applied to integrate expert model structures representing the different components of the hydrologic process. Various signature diagnostic analyses are used to assess the presence of multiple dominant processes and the adequacy of a single model, as well as to identify the structures of the expert models. The approaches are applied for two distinct catchments, the Guadalupe River (Texas) and the French Broad River (North Carolina) from the Model Parameter Estimation Experiment (MOPEX), using different structures of the HBV model. The results show that the HME approach has a better performance over the single model for the Guadalupe catchment, where multiple dominant processes are witnessed through diagnostic measures. Whereas, the diagnostics and aggregated performance measures prove that French Broad has a homogeneous catchment response, making the single model adequate to capture the response.

Assessment of Technogenic Accident Risk of Industrial Building Structures

Science.gov (United States)

Baiburin, D. A.; Baiburin, A. Kh

2017-11-01

A methodology for assessing the risk of an industrial building accident was developed taking into account the damage caused by various localization of collapse. Before the beginning of the survey of a facility technical condition, groups including the same type of building structures are selected. Further, assessment is made for the reduction in their load-carrying capacity from the strength and stability conditions taking into account defects. The characteristics of the influence of defects and structural damage on a building safety is the degree of compliance with the standards expressed by the reliability level. Reliability levels assignment is carried out on the basis of calculations, operating experience and inspection of a particular type of structure according to the formalized rules. The risk of collapse according to a separate scenario is calculated for structures that are capable and incapable of causing a progressive ossification. The results of the technique application are based on the analysis of the accident risk at the welding shop “Vysota (Height) 239” of the Chelyabinsk Pipe Rolling Plant.

On Directionality of Phrase Structure Building

Science.gov (United States)

Chesi, Cristiano

2015-01-01

Minimalism in grammatical theorizing (Chomsky in "The minimalist program." MIT Press, Cambridge, 1995) led to simpler linguistic devices and a better focalization of the core properties of the structure building engine: a lexicon and a free (recursive) phrase formation operation, dubbed Merge, are the basic components that serve in…

Analysis hierarchical model for discrete event systems

Science.gov (United States)

Ciortea, E. M.

2015-11-01

The This paper presents the hierarchical model based on discrete event network for robotic systems. Based on the hierarchical approach, Petri network is analysed as a network of the highest conceptual level and the lowest level of local control. For modelling and control of complex robotic systems using extended Petri nets. Such a system is structured, controlled and analysed in this paper by using Visual Object Net ++ package that is relatively simple and easy to use, and the results are shown as representations easy to interpret. The hierarchical structure of the robotic system is implemented on computers analysed using specialized programs. Implementation of hierarchical model discrete event systems, as a real-time operating system on a computer network connected via a serial bus is possible, where each computer is dedicated to local and Petri model of a subsystem global robotic system. Since Petri models are simplified to apply general computers, analysis, modelling, complex manufacturing systems control can be achieved using Petri nets. Discrete event systems is a pragmatic tool for modelling industrial systems. For system modelling using Petri nets because we have our system where discrete event. To highlight the auxiliary time Petri model using transport stream divided into hierarchical levels and sections are analysed successively. Proposed robotic system simulation using timed Petri, offers the opportunity to view the robotic time. Application of goods or robotic and transmission times obtained by measuring spot is obtained graphics showing the average time for transport activity, using the parameters sets of finished products. individually.

Automated Detection of Buildings from Heterogeneous VHR Satellite Images for Rapid Response to Natural Disasters

Directory of Open Access Journals (Sweden)

Shaodan Li

2017-11-01

Full Text Available In this paper, we present a novel approach for automatically detecting buildings from multiple heterogeneous and uncalibrated very high-resolution (VHR satellite images for a rapid response to natural disasters. In the proposed method, a simple and efficient visual attention method is first used to extract built-up area candidates (BACs from each multispectral (MS satellite image. After this, morphological building indices (MBIs are extracted from all the masked panchromatic (PAN and MS images with BACs to characterize the structural features of buildings. Finally, buildings are automatically detected in a hierarchical probabilistic model by fusing the MBI and masked PAN images. The experimental results show that the proposed method is comparable to supervised classification methods in terms of recall, precision and F-value.

Hierarchical scaffolds enhance osteogenic differentiation of human Wharton’s jelly derived stem cells

International Nuclear Information System (INIS)

Canha-Gouveia, Analuce; Rita Costa-Pinto, Ana; Martins, Albino M; Sousa, Rui A; Reis, Rui L; Neves, Nuno M; Silva, Nuno A; Salgado, António J; Sousa, Nuno; Faria, Susana

2015-01-01

Hierarchical structures, constituted by polymeric nano and microfibers, have been considered promising scaffolds for tissue engineering strategies, mainly because they mimic, in some way, the complexity and nanoscale detail observed in real organs. The chondrogenic potential of these scaffolds has been previously demonstrated, but their osteogenic potential is not yet corroborated. In order to assess if a hierarchical structure, with nanoscale details incorporated, is an improved scaffold for bone tissue regeneration, we evaluate cell adhesion, proliferation, and osteogenic differentiation of human Wharton’s jelly derived stem cells (hWJSCs), seeded into hierarchical fibrous scaffolds. Biological data corroborates that hierarchical fibrous scaffolds show an enhanced cell entrapment when compared to rapid prototyped scaffolds without nanofibers. Furthermore, upregulation of bone specific genes and calcium phosphate deposition confirms the successful osteogenic differentiation of hWJSCs on these scaffolds. These results support our hypothesis that a scaffold with hierarchical structure, in conjugation with hWJSCs, represents a possible feasible strategy for bone tissue engineering applications. (paper)

Seismic safety of building structures of NPP Kozloduy III

International Nuclear Information System (INIS)

Varbanov, G.I.; Kostov, M.K.; Stefanov, D.D.; Kaneva, A.D.

2005-01-01

In the proposed paper is presented a general summary of the analyses carried out to evaluate the dynamic behavior and to assess the seismic safety of some safety related building structures of NPP Kozloduy. The design seismic loads for the site of Kozloduy NPP has been reevaluated and increased during and after the construction of investigated Units 5 and 6. Deterministic and probabilistic approaches are applied to assess the seismic vulnerability of the investigated structures, taking into account the newly defined seismic excitations. The presented results show sufficient seismic safety for the studied critical structures and good efficiency of the seismic upgrading. The applicability of the investigated structures at sites with some higher seismic activities is discussed. The presented study is dealing mainly with the civil structures of the Reactor building, Turbine hall, Diesel Generator Station and Water Intake Structure. (authors)

Structural integrity analysis of an INPP building under external loading

International Nuclear Information System (INIS)

Dundulis, G.; Karalevicius, R.; Uspuras, E.; Kulak, R.F.; Marchertas, A.

2005-01-01

After the terrorist attacks in New York and Washington D. C. using civil airplanes, the evaluation of civil airplane crashes into civil and NPP structures has become very important. The interceptions of many terrorists' communications reveal that the use of commandeered commercial aircraft is still a major part of their plans for destruction. Aircraft crash or other flying objects in the territory of the Ignalina Nuclear Power Plant (INPP) represents a concern to the plant. Aircraft traveling at high velocity have a destructive potential. The aircraft crash may damage the roof and walls of buildings, pipelines, electric motors, cases of power supplies, power cables of electricity transmission and other elements and systems, which are important for safety. Therefore, the evaluation of the structural response to an of aircraft crash is important and was selected for analysis. The structural integrity analysis due to the effects of an aircraft crash on an NPP building structure is the subject of this paper. The finite element method was used for the structural analysis of a typical Ignalina NPP building. The structural integrity analysis was performed for a portion of the ALS using the dynamic loading of an aircraft crash impact model. The computer code NEPTUNE was used for this analysis. The local effects caused by impact of the aircraft's engine on the building wall were evaluated independently by using an empirical formula. (authors)

Analyzing security protocols in hierarchical networks

DEFF Research Database (Denmark)

Zhang, Ye; Nielson, Hanne Riis

2006-01-01

Validating security protocols is a well-known hard problem even in a simple setting of a single global network. But a real network often consists of, besides the public-accessed part, several sub-networks and thereby forms a hierarchical structure. In this paper we first present a process calculus...... capturing the characteristics of hierarchical networks and describe the behavior of protocols on such networks. We then develop a static analysis to automate the validation. Finally we demonstrate how the technique can benefit the protocol development and the design of network systems by presenting a series...

A conceptual modeling framework for discrete event simulation using hierarchical control structures

Science.gov (United States)

Furian, N.; O’Sullivan, M.; Walker, C.; Vössner, S.; Neubacher, D.

2015-01-01

Conceptual Modeling (CM) is a fundamental step in a simulation project. Nevertheless, it is only recently that structured approaches towards the definition and formulation of conceptual models have gained importance in the Discrete Event Simulation (DES) community. As a consequence, frameworks and guidelines for applying CM to DES have emerged and discussion of CM for DES is increasing. However, both the organization of model-components and the identification of behavior and system control from standard CM approaches have shortcomings that limit CM’s applicability to DES. Therefore, we discuss the different aspects of previous CM frameworks and identify their limitations. Further, we present the Hierarchical Control Conceptual Modeling framework that pays more attention to the identification of a models’ system behavior, control policies and dispatching routines and their structured representation within a conceptual model. The framework guides the user step-by-step through the modeling process and is illustrated by a worked example. PMID:26778940

A conceptual modeling framework for discrete event simulation using hierarchical control structures.

Science.gov (United States)

Furian, N; O'Sullivan, M; Walker, C; Vössner, S; Neubacher, D

2015-08-01

Conceptual Modeling (CM) is a fundamental step in a simulation project. Nevertheless, it is only recently that structured approaches towards the definition and formulation of conceptual models have gained importance in the Discrete Event Simulation (DES) community. As a consequence, frameworks and guidelines for applying CM to DES have emerged and discussion of CM for DES is increasing. However, both the organization of model-components and the identification of behavior and system control from standard CM approaches have shortcomings that limit CM's applicability to DES. Therefore, we discuss the different aspects of previous CM frameworks and identify their limitations. Further, we present the Hierarchical Control Conceptual Modeling framework that pays more attention to the identification of a models' system behavior, control policies and dispatching routines and their structured representation within a conceptual model. The framework guides the user step-by-step through the modeling process and is illustrated by a worked example.

Predicting allergic contact dermatitis: a hierarchical structure activity relationship (SAR) approach to chemical classification using topological and quantum chemical descriptors

Science.gov (United States)

Basak, Subhash C.; Mills, Denise; Hawkins, Douglas M.

2008-06-01

A hierarchical classification study was carried out based on a set of 70 chemicals—35 which produce allergic contact dermatitis (ACD) and 35 which do not. This approach was implemented using a regular ridge regression computer code, followed by conversion of regression output to binary data values. The hierarchical descriptor classes used in the modeling include topostructural (TS), topochemical (TC), and quantum chemical (QC), all of which are based solely on chemical structure. The concordance, sensitivity, and specificity are reported. The model based on the TC descriptors was found to be the best, while the TS model was extremely poor.

Diagnostic Classifiers: Revealing how Neural Networks Process Hierarchical Structure

NARCIS (Netherlands)

Veldhoen, S.; Hupkes, D.; Zuidema, W.

2016-01-01

We investigate how neural networks can be used for hierarchical, compositional semantics. To this end, we define the simple but nontrivial artificial task of processing nested arithmetic expressions and study whether different types of neural networks can learn to add and subtract. We find that

Adaptive building skin structures

International Nuclear Information System (INIS)

Del Grosso, A E; Basso, P

2010-01-01

The concept of adaptive and morphing structures has gained considerable attention in the recent years in many fields of engineering. In civil engineering very few practical applications are reported to date however. Non-conventional structural concepts like deployable, inflatable and morphing structures may indeed provide innovative solutions to some of the problems that the construction industry is being called to face. To give some examples, searches for low-energy consumption or even energy-harvesting green buildings are amongst such problems. This paper first presents a review of the above problems and technologies, which shows how the solution to these problems requires a multidisciplinary approach, involving the integration of architectural and engineering disciplines. The discussion continues with the presentation of a possible application of two adaptive and dynamically morphing structures which are proposed for the realization of an acoustic envelope. The core of the two applications is the use of a novel optimization process which leads the search for optimal solutions by means of an evolutionary technique while the compatibility of the resulting configurations of the adaptive envelope is ensured by the virtual force density method

Intrinsic hierarchical structural imperfections in a natural ceramic of bivalve shell with distinctly graded properties.

Science.gov (United States)

Jiao, Da; Liu, Zengqian; Zhang, Zhenjun; Zhang, Zhefeng

2015-07-22

Despite the extensive investigation on the structure of natural biological materials, insufficient attention has been paid to the structural imperfections by which the mechanical properties of synthetic materials are dominated. In this study, the structure of bivalve Saxidomus purpuratus shell has been systematically characterized quantitatively on multiple length scales from millimeter to sub-nanometer. It is revealed that hierarchical imperfections are intrinsically involved in the crossed-lamellar structure of the shell despite its periodically packed platelets. In particular, various favorable characters which are always pursued in synthetic materials, e.g. nanotwins and low-angle misorientations, have been incorporated herein. The possible contributions of these imperfections to mechanical properties are further discussed. It is suggested that the imperfections may serve as structural adaptations, rather than detrimental defects in the real sense, to help improve the mechanical properties of natural biological materials. This study may aid in understanding the optimizing strategies of structure and properties designed by nature, and accordingly, provide inspiration for the design of synthetic materials.

A hierarchical model for structure learning based on the physiological characteristics of neurons

Institute of Scientific and Technical Information of China (English)

WEI Hui

2007-01-01

Almost all applications of Artificial Neural Networks (ANNs) depend mainly on their memory ability.The characteristics of typical ANN models are fixed connections,with evolved weights,globalized representations,and globalized optimizations,all based on a mathematical approach.This makes those models to be deficient in robustness,efficiency of learning,capacity,anti-jamming between training sets,and correlativity of samples,etc.In this paper,we attempt to address these problems by adopting the characteristics of biological neurons in morphology and signal processing.A hierarchical neural network was designed and realized to implement structure learning and representations based on connected structures.The basic characteristics of this model are localized and random connections,field limitations of neuron fan-in and fan-out,dynamic behavior of neurons,and samples represented through different sub-circuits of neurons specialized into different response patterns.At the end of this paper,some important aspects of error correction,capacity,learning efficiency,and soundness of structural representation are analyzed theoretically.This paper has demonstrated the feasibility and advantages of structure learning and representation.This model can serve as a fundamental element of cognitive systems such as perception and associative memory.Key-words structure learning,representation,associative memory,computational neuroscience

Structural design of the turbine building of Angra Nuclear Power Station, Unit 1

International Nuclear Information System (INIS)

Varella, L.N.; Reis, F.J.C.; Jurkiewicz, W.J.

1978-01-01

The Turbine Building of the Angra Nuclear Power Plant, Unit 1, and particularly its structure and structural design are described. The Turbine Building, as far as its structure is concerned, deviates from the standard structure of any turbine building due to the fact that huge ducts are provided in the foundation mat as to accomodate the circulating water system. This aspect and the fact that the building is founded upon a very deep strata of compacted and controlled fill, makes out of the building structure 'a concrete ship floating in the sea of sand', and by the same reason presents by itself an interesting structure, worth to be known to all engineers involved in design of power plants. This pape, suplemented by a few slides shown during presentation of the paper at the conference, covers the subject mainly from the designers' point of view. (Author)

Calculation methods of Structure-Soil-Structure Interaction (3SI) for embedded buildings: Application to NUPEC tests

International Nuclear Information System (INIS)

Clouteau, D.; Broc, D.; Devesa, G.; Guyonvarh, V.; Massin, P.

2012-01-01

This work aims at improving and validating methods coupling Finite Element (FE) and Boundary Element (BE) Methods in the context of Soil-Structure Interaction (SSI) and Structure-Soil-Structure Interaction (3SI) tests performed by NUPEC on mock-up structures built on an unmade ground. Several cases have been tested: single and juxtaposed buildings, shallow and embedded foundations, with various loading conditions: forced and natural seismic loadings. The numerical simulations of forced vibration tests are in good agreement with the results of the NUPEC experiments in the case of two embedded buildings either in terms of amplitude and resonance. The numerical simulation of seismic response tests by FEM and BEM allows for a proper choice of the 'reference point' where the computed and the experimental displacements coincide. A parametric analysis of Structure-Soil-Structure Interaction carried out by the FEM has allowed to determine the influence of some parameters on SSI. Most of them like the position of the building in the excavation, the direction of the load, the quality of the contact between the sidewalls of the buildings and the soil for embedded foundations, do not show to have a strong influence on the dynamic system behaviour, which is mainly governed by the stiffness of the first soil layer. As far as 3SI is concerned, this paper shows that when the cross interaction has a small effect on the building response in the case of surface foundations, it has a strong influence in the case of embedded foundations with an important decrease of the response at the top of the buildings. (authors)

Dynamic soil-structure interactions on embedded buildings

International Nuclear Information System (INIS)

Kobarg, J.; Werkle, H.; Henseleit, O.

1983-01-01

The dynamic soil-structure interaction on the horizontal seismic excitation is investigated on two typical embedded auxiliary buildings of a nuclear power plant. The structure and the soil are modelled by various analytical and numerical methods. Under the condition of the linear viscoelastic theory, i.e. soil characteristic constant in time and independent of strain, the interaction influences between a homogenous soil layer and a structure are analysied for the following parameters: 4) mathematical soil modells; 4) mathematical structure modells; 4) shear wave velocities; 3) embedment conditions; 4) earthquake time histories. (orig.) [de

Hierarchical Modelling of Flood Risk for Engineering Decision Analysis

DEFF Research Database (Denmark)

Custer, Rocco

protection structures in the hierarchical flood protection system - is identified. To optimise the design of protection structures, fragility and vulnerability models must allow for consideration of decision alternatives. While such vulnerability models are available for large protection structures (e...... systems, as well as the implementation of the flood risk analysis methodology and the vulnerability modelling approach are illustrated with an example application. In summary, the present thesis provides a characterisation of hierarchical flood protection systems as well as several methodologies to model...... and robust. Traditional risk management solutions, e.g. dike construction, are not particularly flexible, as they are difficult to adapt to changing risk. Conversely, the recent concept of integrated flood risk management, entailing a combination of several structural and non-structural risk management...

The Emergence of Hierarchical Structure in Human Language

Directory of Open Access Journals (Sweden)

Shigeru eMiyagawa

2013-02-01

Full Text Available We propose a novel account for the emergence of human language syntax. Like many evolutionary innovations, language arose from the adventitious combination of two pre-existing, simpler systems that had been evolved for other functional tasks. The first system, Type E(xpression, is found in birdsong, where it marks territory, mating availability, and similar ‘expressive’ functions. The second system, Type L(exical, has been suggestively found in non-human primate calls and in honeybee waggle dances, where it demarcates predicates with one or more ‘arguments,’ such as combinations of calls in monkeys or compass headings set to sun position in honeybees. We show that human language syntax is composed of two layers that parallel these two independently evolved systems: an E layer resembling the Type E system of birdsong and an L layer providing words. The existence of the E and L layers can be confirmed using standard linguistic methodology. Each layer, E and L, when considered separately, are characterizable as finite state systems, as observed in several non-human species. When the two systems are put together they interact, yielding the unbounded, non-finite state, hierarchical structure that serves as the hallmark of ful

Extent of moisture and mould damage in structures of public buildings

Directory of Open Access Journals (Sweden)

Petri J. Annila

2017-06-01

Full Text Available The study concentrated on the extent of moisture and mould damage in different structures in 25 public buildings in Finland. Users of all the buildings had health symptoms suspected to be the result of moisture and mould damage, which is why moisture performance assessments had been performed. The assessment reports on each building were available as research material. The reports indicated that the examined buildings suffered from multiple moisture and mould problems in several different structures. On average, however, a relatively small proportion of the total number of structures had suffered damage. On the basis of the research material, damage was most extensive in walls in soil contact (16.3% and base floor structures (12.5%. The lowest damage rates were found in partition walls (2.4%, external walls (2.6% and intermediate floors (2.5%. The results of the study underline the importance of thorough moisture performance assessments to ensure that all point-sized moisture and mould damage is detected.

Robust Real-Time Music Transcription with a Compositional Hierarchical Model.

Science.gov (United States)

Pesek, Matevž; Leonardis, Aleš; Marolt, Matija

2017-01-01

The paper presents a new compositional hierarchical model for robust music transcription. Its main features are unsupervised learning of a hierarchical representation of input data, transparency, which enables insights into the learned representation, as well as robustness and speed which make it suitable for real-world and real-time use. The model consists of multiple layers, each composed of a number of parts. The hierarchical nature of the model corresponds well to hierarchical structures in music. The parts in lower layers correspond to low-level concepts (e.g. tone partials), while the parts in higher layers combine lower-level representations into more complex concepts (tones, chords). The layers are learned in an unsupervised manner from music signals. Parts in each layer are compositions of parts from previous layers based on statistical co-occurrences as the driving force of the learning process. In the paper, we present the model's structure and compare it to other hierarchical approaches in the field of music information retrieval. We evaluate the model's performance for the multiple fundamental frequency estimation. Finally, we elaborate on extensions of the model towards other music information retrieval tasks.

A Hierarchically Micro-Meso-Macroporous Zeolite CaA for Methanol Conversion to Dimethyl Ether

Directory of Open Access Journals (Sweden)

Yan Wang

2016-11-01

Full Text Available A hierarchical zeolite CaA with microporous, mesoporous and macroporous structure was hydrothermally synthesized by a ”Bond-Blocking” method using organo-functionalized mesoporous silica (MS as a silica source. The characterization by XRD, SEM/TEM and N2 adsorption/desorption techniques showed that the prepared material had well-crystalline zeolite Linde Type A (LTA topological structure, microspherical particle morphologies, and hierarchically intracrystalline micro-meso-macropores structure. With the Bond-Blocking principle, the external surface area and macro-mesoporosity of the hierarchical zeolite CaA can be adjusted by varying the organo-functionalized degree of the mesoporous silica surface. Similarly, the distribution of the micro-meso-macroporous structure in the zeolite CaA can be controlled purposely. Compared with the conventional microporous zeolite CaA, the hierarchical zeolite CaA as a catalyst in the conversion of methanol to dimethyl ether (DME, exhibited complete DME selectivity and stable catalytic activity with high methanol conversion. The catalytic performances of the hierarchical zeolite CaA results clearly from the micro-meso-macroporous structure, improving diffusion properties, favoring the access to the active surface and avoiding secondary reactions (no hydrocarbon products were detected after 3 h of reaction.

Structural response of steel high rise buildings to fire

DEFF Research Database (Denmark)

Gentili, Filippo; Giuliani, Luisa; Bontempi, Franco

2013-01-01

Due to the significant vertical elevation and complexity of the structural system, high rise buildings may suffer from the effects of fire more than other structures. For this reason, in addition to evacuation strategies and active fire protection, a careful consideration of structural response t...

Packaging glass with hierarchically nanostructured surface

KAUST Repository

He, Jr-Hau; Fu, Hui-Chun

2017-01-01

An optical device includes an active region and packaging glass located on top of the active region. A top surface of the packaging glass includes hierarchical nanostructures comprised of honeycombed nanowalls (HNWs) and nanorod (NR) structures

Multi functional roof structures of the energy efficient buildings

Directory of Open Access Journals (Sweden)

Krstić Aleksandra

2006-01-01

Full Text Available Modern architectural concepts, which are based on rational energy consumption of buildings and the use of solar energy as a renewable energy source, give the new and significant role to the roofs that become multifunctional structures. Various energy efficient roof structures and elements, beside the role of protection, provide thermal and electric energy supply, natural ventilation and cooling of a building, natural lighting of the indoor space sunbeam protection, water supply for technical use, thus according to the above mentioned functions, classification and analysis of such roof structures and elements are made in this paper. The search for new architectural values and optimization in total energy balance of a building or the likewise for the urban complex, gave to roofs the role of "climatic membranes". Contemporary roof forms and materials clearly exemplify their multifunctional features. There are numerous possibilities to achieve the new and attractive roof design which broadens to the whole construction. With such inducement, this paper principally analyze the configuration characteristics of the energy efficient roof structures and elements, as well as the visual effects that may be achieved by their application.

Biominerals- hierarchical nanocomposites: the example of bone

Science.gov (United States)

Beniash, Elia

2010-01-01

Many organisms incorporate inorganic solids in their tissues to enhance their functional, primarily mechanical, properties. These mineralized tissues, also called biominerals, are unique organo-mineral nanocomposites, organized at several hierarchical levels, from nano- to macroscale. Unlike man made composite materials, which often are simple physical blends of their components, the organic and inorganic phases in biominerals interface at the molecular level. Although these tissues are made of relatively weak components at ambient conditions, their hierarchical structural organization and intimate interactions between different elements lead to superior mechanical properties. Understanding basic principles of formation, structure and functional properties of these tissues might lead to novel bioinspired strategies for material design and better treatments for diseases of the mineralized tissues. This review focuses on general principles of structural organization, formation and functional properties of biominerals on the example the bone tissues. PMID:20827739

Functional Biomass Carbons with Hierarchical Porous Structure for Supercapacitor Electrode Materials

International Nuclear Information System (INIS)

Chen, Hao; Liu, Duo; Shen, Zhehong; Bao, Binfu; Zhao, Shuyan; Wu, Limin

2015-01-01

Highlights: • We successfully prepared bamboo-derived porous carbon with B and N co-doping. • This novel carbon exhibits significantly enhanced specific capacitance and energy density. • The highest specific capacitance exceeds those of most similar carbon materials. • Asymmetric supercapacitor based on this carbon shows satisfactory capacitive performance. - Abstract: This paper presents nitrogen and boron co-doped KOH-activated bamboo-derived carbon as a porous biomass carbon with utility as a supercapacitor electrode material. Owing to the high electrochemical activity promoted by the hierarchical porous structure and further endowed by boron and nitrogen co-doping, electrodes based on the as-obtained material exhibit significantly enhanced specific capacitance and energy density relative to those based on most similar materials. An asymmetric supercapacitor based on this novel carbon material demonstrated satisfactory energy density and electrochemical cycling stability.

Hierarchical modularity in human brain functional networks

Directory of Open Access Journals (Sweden)

David Meunier

2009-10-01

Full Text Available The idea that complex systems have a hierarchical modular organization originates in the early 1960s and has recently attracted fresh support from quantitative studies of large scale, real-life networks. Here we investigate the hierarchical modular (or “modules-within-modules” decomposition of human brain functional networks, measured using functional magnetic resonance imaging (fMRI in 18 healthy volunteers under no-task or resting conditions. We used a customized template to extract networks with more than 1800 regional nodes, and we applied a fast algorithm to identify nested modular structure at several hierarchical levels. We used mutual information, 0 < I < 1, to estimate the similarity of community structure of networks in different subjects, and to identify the individual network that is most representative of the group. Results show that human brain functional networks have a hierarchical modular organization with a fair degree of similarity between subjects, I=0.63. The largest 5 modules at the highest level of the hierarchy were medial occipital, lateral occipital, central, parieto-frontal and fronto-temporal systems; occipital modules demonstrated less sub-modular organization than modules comprising regions of multimodal association cortex. Connector nodes and hubs, with a key role in inter-modular connectivity, were also concentrated in association cortical areas. We conclude that methods are available for hierarchical modular decomposition of large numbers of high resolution brain functional networks using computationally expedient algorithms. This could enable future investigations of Simon's original hypothesis that hierarchy or near-decomposability of physical symbol systems is a critical design feature for their fast adaptivity to changing environmental conditions.

Broadband locally resonant metamaterials with graded hierarchical architecture

Science.gov (United States)

Liu, Chenchen; Reina, Celia

2018-03-01

We investigate the effect of hierarchical designs on the bandgap structure of periodic lattice systems with inner resonators. A detailed parameter study reveals various interesting features of structures with two levels of hierarchy as compared with one level systems with identical static mass. In particular: (i) their overall bandwidth is approximately equal, yet bounded above by the bandwidth of the single-resonator system; (ii) the number of bandgaps increases with the level of hierarchy; and (iii) the spectrum of bandgap frequencies is also enlarged. Taking advantage of these features, we propose graded hierarchical structures with ultra-broadband properties. These designs are validated over analogous continuum models via finite element simulations, demonstrating their capability to overcome the bandwidth narrowness that is typical of resonant metamaterials.

An economic growth model based on financial credits distribution to the government economy priority sectors of each regency in Indonesia using hierarchical Bayesian method

Science.gov (United States)

Yasmirullah, Septia Devi Prihastuti; Iriawan, Nur; Sipayung, Feronika Rosalinda

2017-11-01

The success of regional economic establishment could be measured by economic growth. Since the Act No. 32 of 2004 has been implemented, unbalance economic among the regency in Indonesia is increasing. This condition is contrary different with the government goal to build society welfare through the economic activity development in each region. This research aims to examine economic growth through the distribution of bank credits to each Indonesia's regency. The data analyzed in this research is hierarchically structured data which follow normal distribution in first level. Two modeling approaches are employed in this research, a global-one level Bayesian approach and two-level hierarchical Bayesian approach. The result shows that hierarchical Bayesian has succeeded to demonstrate a better estimation than a global-one level Bayesian. It proves that the different economic growth in each province is significantly influenced by the variations of micro level characteristics in each province. These variations are significantly affected by cities and province characteristics in second level.

The role of the hierarchical theory in explaining the capital structure of the firms based on enterprise life cycle model

Directory of Open Access Journals (Sweden)

Jamal Bahiri Saleth

2016-01-01

Full Text Available Capital structure is a controversial issue in the field of corporate finance. There are several studies to find a way to determine the optimal capital structure to minimize the cost of capital and maximize the corporate value. In fact, capital structure is a combination of firms’ liabilities and capital to meet long term assets. This paper investigates the role of the hierarchical theory in explaining the capital structure of the firms based on enterprise life cycle model on selected firms listed on Tehran Stock Exchange (TSE using three methods of net equities, net liabilities and retained earnings. The study uses Park and Chen’s (2006 method [Park, Y., & Chen, K. H. (2006. The effect of accounting conservatism and life-cycle stages on firm valuation. Journal of Applied Business Research (JABR, 22(3, 75-92.] to categorize the life cycle of 81 randomly selected firms from TSE over the period 2007-2012. The results indicate that the hierarchical theory represents the growing firms better than the matured firms do. The results also show that firms were more willing to reduce their dividend per share for financing their projects.

A Hierarchical Clustering Methodology for the Estimation of Toxicity

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A Quantitative Structure Activity Relationship (QSAR) methodology based on hierarchical clustering was developed to predict toxicological endpoints. This methodology utilizes Ward's method to divide a training set into a series of structurally similar clusters. The structural sim...

Finding the displacement of wood structure in heritage building by 3D laser scanner

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Lee, M. C.; Tsai, Y. L.; Wang, R. Z.; Lin, M. L.

2015-08-01

Heritage buildings are highly prone to long term damage from the microclimate, scourge and vandalism, which can result in damaged materials, structures, painting and cultural heritage items. This study will focus on finding the displacement of wood structural members through the use of a 3D laser scanner and the 4D concept of time. The results will compare the scans from different periods to find the difference (if any) in the structural member position. Wood structures usually consist of numerous wood members connected to form the structure. However, these members can be damaged in various ways such as physical mechanisms, chemical reactions, and biological corrosion. When damage to the wood structure occurs, the structural displacement can be affected, and if affected severely, can lead to a building collapse. Monitoring of the structural displacement is the best way to discover damage immediately and to preserve the heritage building. However, the Cultural Heritage Preservation Law in Taiwan prohibits the installation of monitoring instruments (e.g strain gauge, accelerometer) in historic structures (heritage buildings). Scanning the wood structure with 3D lasers is the most non-intrusive method and quickly achieves displacement through visualization. The displacement scan results can be compared with different periods and different members to analyze the severity of damage. Once the 3D scanner is installed, the whole building is scanned, and point clouds created to build the visual building model. The structural displacement can be checked via the building model and the differences are measured between each member to find the high risk damaged areas or members with large displacement. Early detection of structural damage is the most effective way means of preservation.

LIFE-CYCLE COST MODEL AND DESIGN OPTIMIZATION OF BASE ISOLATED BUILDING STRUCTURES

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Chara C. Mitropoulou

2016-11-01

Full Text Available Design of economic structures adequately resistant to withstand during their service life, without catastrophic failures, all possible loading conditions and to absorb the induced seismic energy in a controlled fashion, has been the subject of intensive research so far. Modern buildings usually contain extremely sensitive and costly equipment that are vital in business, commerce, education and/or health care. The building contents frequently are more valuable than the buildings them-selves. Furthermore, hospitals, communication and emergency centres, police and fire stations must be operational when needed most: immediately after an earthquake. Conventional con-struction can cause very high floor accelerations in stiff buildings and large interstorey drifts in flexible structures. These two factors cause difficulties in insuring the safety of both building and its contents. For this reason base-isolated structures are considered as an efficient alternative design practice to the conventional fixed-base one. In this study a systematic assessment of op-timized fixed and base-isolated reinforced concrete buildings is presented in terms of their initial and total cost taking into account the life-cycle cost of the structures.

Synthesis of Pt@TiO2@CNTs Hierarchical Structure Catalyst by Atomic Layer Deposition and Their Photocatalytic and Photoelectrochemical Activity.

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Liao, Shih-Yun; Yang, Ya-Chu; Huang, Sheng-Hsin; Gan, Jon-Yiew

2017-04-29

Pt@TiO2@CNTs hierarchical structures were prepared by first functionalizing carbon nanotubes (CNTs) with nitric acid at 140 °C. Coating of TiO2 particles on the CNTs at 300 °C was then conducted by atomic layer deposition (ALD). After the TiO2@CNTs structure was fabricated, Pt particles were deposited on the TiO2 surface as co-catalyst by plasma-enhanced ALD. The saturated deposition rates of TiO2 on a-CNTs were 1.5 Å/cycle and 0.4 Å/cycle for substrate-enhanced process and linear process, respectively. The saturated deposition rate of Pt on TiO2 was 0.39 Å/cycle. The photocatalytic activities of Pt@TiO2@CNTs hierarchical structures were higher than those without Pt co-catalyst. The particle size of Pt on TiO2@CNTs was a key factor to determine the efficiency of methylene blue (MB) degradation. The Pt@TiO2@CNTs of 2.41 ± 0.27 nm exhibited the best efficiency of MB degradation.

Hierarchical Micro/Nano Structures by Combined Self-Organized Dewetting and Photopatterning of Photoresist Thin Films.

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Sachan, Priyanka; Kulkarni, Manish; Sharma, Ashutosh

2015-11-17

Photoresists are the materials of choice for micro/nanopatterning and device fabrication but are rarely used as a self-assembly material. We report for the first time a novel interplay of self-assembly and photolithography for fabrication of hierarchical and ordered micro/nano structures. We create self-organized structures by the intensified dewetting of unstable thin (∼10 nm to 1 μm) photoresist films by annealing them in an optimal solvent and nonsolvent liquid mixture that allows spontaneous dewetting to form micro/nano smooth dome-like structures. The density, size (∼100 nm to millimeters), and curvature/contact angle of the dome/droplet structures are controlled by the film thickness, composition of the dewetting liquid, and time of annealing. Ordered dewetted structures are obtained simply by creating spatial variation of viscosity by ultraviolet exposure or by photopatterning before dewetting. Further, the structures thus fabricated are readily photopatterned again on the finer length scales after dewetting. We illustrate the approach by fabricating several three-dimensional structures of varying complexity with secondary and tertiary features.

An Approach to Structure Determination and Estimation of Hierarchical Archimedean Copulas and its Application to Bayesian Classification

Czech Academy of Sciences Publication Activity Database

Górecki, J.; Hofert, M.; Holeňa, Martin

2016-01-01

Roč. 46, č. 1 (2016), s. 21-59 ISSN 0925-9902 R&D Projects: GA ČR GA13-17187S Grant - others:Slezská univerzita v Opavě(CZ) SGS/21/2014 Institutional support: RVO:67985807 Keywords : Copula * Hierarchical archimedean copula * Copula estimation * Structure determination * Kendall’s tau * Bayesian classification Subject RIV: IN - Informatics, Computer Science Impact factor: 1.294, year: 2016

RANDOM FUNCTIONS AND INTERVAL METHOD FOR PREDICTING THE RESIDUAL RESOURCE OF BUILDING STRUCTURES

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Shmelev Gennadiy Dmitrievich

2017-11-01

Full Text Available Subject: possibility of using random functions and interval prediction method for estimating the residual life of building structures in the currently used buildings. Research objectives: coordination of ranges of values to develop predictions and random functions that characterize the processes being predicted. Materials and methods: when performing this research, the method of random functions and the method of interval prediction were used. Results: in the course of this work, the basic properties of random functions, including the properties of families of random functions, are studied. The coordination of time-varying impacts and loads on building structures is considered from the viewpoint of their influence on structures and representation of the structures’ behavior in the form of random functions. Several models of random functions are proposed for predicting individual parameters of structures. For each of the proposed models, its scope of application is defined. The article notes that the considered approach of forecasting has been used many times at various sites. In addition, the available results allowed the authors to develop a methodology for assessing the technical condition and residual life of building structures for the currently used facilities. Conclusions: we studied the possibility of using random functions and processes for the purposes of forecasting the residual service lives of structures in buildings and engineering constructions. We considered the possibility of using an interval forecasting approach to estimate changes in defining parameters of building structures and their technical condition. A comprehensive technique for forecasting the residual life of building structures using the interval approach is proposed.