WorldWideScience

Sample records for adaptive physicochemical structure

  1. Adaptive Space Structures

    Wada, B.

    1993-01-01

    The term adaptive structures refers to a structural control approach in which sensors, actuators, electronics, materials, structures, structural concepts, and system-performance-validation strategies are integrated to achieve specific objectives.

  2. Diffractaic acid: Crystalline structure and physicochemical characterization

    de Castro Fonseca, Jéssica; de Oliveira, Yara Santiago; Bezerra, Beatriz P.; Ellena, Javier; Honda, Neli Kika; Silva, Camilla V. N. S.; da Silva Santos, Noemia Pereira; Santos-Magalhães, Nereide Stela; Ayala, Alejandro Pedro

    2016-08-01

    Diffractaic acid (DA) is a secondary metabolite of lichens that belongs to the chemical class of depsides, and some relevant pharmacological properties are associated with this natural product, such as antioxidant, antiulcerogenic and gastroprotective effects. Considering the relevant biological activities and taking into account that the activities are intrinsically related to the structure, the main goal of this study was to elucidate the structure of diffractaic acid by single crystal X-ray diffraction as well to characterize its physicochemical properties by powder X-ray diffraction, thermal analysis and vibrational spectroscopy. It was observed that DA belongs to the monoclinic crystal system, crystallizing in the space group P21/c with the following cell parameters: a = 18.535(7) Å, b = 4.0439(18) Å, c = 23.964(6) Å, β = 91.55(3)°. The crystal packing is characterized by difractaic acid dimers, which are reflected in the vibrational spectrum. These observations were supported by quantum mechanical calculations.

  3. Robust Adaptive Structural Control

    Yang, Chi-Ming; Beck, James L.

    1995-01-01

    A new robust adaptive structural control design methodology is developed and presented which treats modeling uncertainties and limitations of control devices. Furthermore, no restriction is imposed on the structural models and the nature of the control devices so that the proposed method is very general. A simple linear single degree-of-freedom numerical example is presented to illustrate this approach.

  4. Adaptive structures flight experiments

    Martin, Maurice

    The topics are presented in viewgraph form and include the following: adaptive structures flight experiments; enhanced resolution using active vibration suppression; Advanced Controls Technology Experiment (ACTEX); ACTEX program status; ACTEX-2; ACTEX-2 program status; modular control patch; STRV-1b Cryocooler Vibration Suppression Experiment; STRV-1b program status; Precision Optical Bench Experiment (PROBE); Clementine Spacecraft Configuration; TECHSAT all-composite spacecraft; Inexpensive Structures and Materials Flight Experiment (INFLEX); and INFLEX program status.

  5. Structure and physico-chemical properties of Kumkol petroleum deposit

    Results of study of physico-chemical properties and structure of Kumkol deposit petroleum in Southern Kazakhstan are presented. It is determined, that these petroleums are light, paraffinic, with low sulfur and ash contents, has insignificant concentration of vanadium and nickel, and has not porphyrin complexes. (author)

  6. Adaptive building skin structures

    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

  7. [Physico-chemical properties of microbial and plant polysaccharides structurants].

    Votselko, S K; Dankevytch, L A; Lytvynchuk, O O

    2012-01-01

    The comparative investigation of physico-chemical properties of plant (guar gum, konjac-mannan) and microbial (xanthan gum) origin structurants have been carried out. Among them, xanthan sigma (1544 mPa) and konjac-mannan (5000 mPa) have the best initial viscosity. It has been shown that due to molecular-mass characteristics xanthan (74.3%) gum, ksampan (39%) and konjac-mannan (42.1%) have the highest percentage of high-weight fractions. It has been established that mannose, glucose and galactose as well as unidentified substances are presented in different concentrations in the structure of structurants. PMID:22686017

  8. Adaptive Structural Mode Control Project

    National Aeronautics and Space Administration — M4 Engineering proposes the development of an adaptive structural mode control system. The adaptive control system will begin from a "baseline" dynamic model of the...

  9. Distribution of Fish in the Upper Citarum River: an Adaptive Response to Physico-Chemical Properties

    SUNARDI; KEUKEU KANIAWATI; TEGUH HUSODO; DESAK MADE MALINI; ANNISA JOVIANI ASTARI

    2012-01-01

    Distribution of fish in river is controlled by physico-chemical properties of the water which is affected by land-use complexity and intensity of human intervention. A study on fish distribution was carried out in the upper Citarum River to map the effects of physio-chemical properties on habitat use. A survey was conducted to collect fish and to measure the water quality both on dry and rainy season. The result showed that distribution of the fish, in general, represented their adaptive resp...

  10. Structures and physicochemical properties of molecular aggregates of lipids

    Structures and physicochemical properties of lipids such as fatty acids, alcohols, acylglycerols and steroids in their two- or three-dimensional states were studied through the measurements of surface pressure (π), surface-molecular area (A), vapor-pressure osmosis, radioactivity (R), self-diffusion coefficient (D), density, viscosity, near-infrared spectroscopy (NIR), 13C-NMR spin-lattice relaxation time (T1), ESR, SEM, DSC, X-ray diffraction and small-angle neutron scattering (SANS). Following results are obtained: (1) π-A and R-A relationships indicate that the explanation, being widely believed, of the reaction occurred in the oleic acid or the trioleylglycerol monolayer on the aqueous KMnO4 solution is incorrect. (2) By using the LB film of 3H-labelled fatty acid, the upper limit of the neutrino mass was determined. In addition, by using the LB film of 14C-labelled fatty acid, a new type of crystal-transformation process was found, in which fatty-acid crystal transforms from its unstable state to its stable one by the transfer of the fatty acid molecules through the vapor phase. (3) Fatty acids always exist as their dimers in their liquid state and mostly in non-polar solvents; the dimers are the units of the molecular movements in the molten liquid and in solvents. T1 results clearly showed the internal molecular movements of the dimers. In addition, D and SANS results indicated that two different kinds of fatty acids in their binary mixture make only each homodimers. (4) Furthermore, the study on the liquid structure of fatty acids such as cis-6-, cis-9-, cis-11-, trans-9-octadecenoic acids and stearic acid indicated that these fatty-acid dimers construct the clusters resemble to the smectic-liquid crystal in the liquid state. The clusters determine the physicochemical properties of the liquid of the fatty acid. (author)

  11. Physicochemical and structural studies of clathrate hydrates of tetrabutylammonium polyacrylates.

    Terekhova, Irina S; Manakov, Andrey Yu; Komarov, Vladislav Yu; Villevald, Galina V; Burdin, Alexander A; Karpova, Tamara D; Aladko, Eugeny Ya

    2013-03-01

    In this work, physicochemical and structural studies have been carried out for semiclathrate hydrates of linear (un-cross-linked) and cross-linked tetrabutylammonium polyacrylates with different degrees of cross-linking of the polymeric guest molecules (n = 0.5, 1, 2, 3%) and different degrees of substitution of proton ions of carboxylic groups in poly(acrylic acid) for TBA cations (x = 1, 0.8, 0.6). The changes in the hydrates' stability and composition depending on the outlined parameters were examined in the course of phase diagram studies of the binary systems water-tetrabutylammonium polyacrylates using differential thermal analysis method and calorimetric measurements of fusion enthalpies of the hydrates. Phase diagram studies of the binary system water-linear tetrabutylammonium polyacrylate revealed the formation of four hydrates. Based on the data of chemical analysis of hydrate crystals the compositions of all hydrates have been determined. Single-crystal X-ray diffraction studies revealed a tetragonal structure, space group 4/m, and unit cell parameters are close for different hydrates and lie in the ranges a = 23.4289-23.4713 Å and c = 12.3280-12.3651 Å (150 K). The structure can be related to tetragonal structure I typical for the clathrate hydrates of tetraalkylammonium salts with monomeric anions. Powder X-ray diffraction analyses confirmed the identity of the above crystal structure to that of the hydrates with cross-linked tetrabutylammonium polyacrylates. The behavior of TBA polyacrylate hydrates under the pressure of methane was studied and quantitative assessment of the gas content in the hydrates was made using volumetric analysis method. PMID:23383955

  12. Electronic structure and physicochemical properties of selected penicillins

    Soriano-Correa, Catalina; Ruiz, Juan F. Sánchez; Raya, A.; Esquivel, Rodolfo O.

    Traditionally, penicillins have been used as antibacterial agents due to their characteristics and widespread applications with few collateral effects, which have motivated several theoretical and experimental studies. Despite the latter, their mechanism of biological action has not been completely elucidated. We present a theoretical study at the Hartree-Fock and density functional theory (DFT) levels of theory of a selected group of penicillins such as the penicillin-G, amoxicillin, ampicillin, dicloxacillin, and carbenicillin molecules, to systematically determine the electron structure of full ?-lactam antibiotics. Our results allow us to analyze the electronic properties of the pharmacophore group, the aminoacyl side-chain, and the influence of the substituents (R and X) attached to the aminoacyl side-chain at 6? (in contrast with previous studies focused at the 3? substituents), and to corroborate the results of previous studies performed at the semiempirical level, solely on the ?-lactam ring of penicillins. Besides, several density descriptors are determined with the purpose of analyzing their link to the antibacterial activity of these penicillin compounds. Our results for the atomic charges (fitted to the electrostatic potential), the bond orders, and several global reactivity descriptors, such as the dipole moments, ionization potential, hardness, and the electrophilicity index, led us to characterize: the active sites, the effect of the electron-attracting substituent properties and their physicochemical features, which altogether, might be important to understand the biological activity of these type of molecules.

  13. Improving protein fold recognition and structural class prediction accuracies using physicochemical properties of amino acids.

    Raicar, Gaurav; Saini, Harsh; Dehzangi, Abdollah; Lal, Sunil; Sharma, Alok

    2016-08-01

    Predicting the three-dimensional (3-D) structure of a protein is an important task in the field of bioinformatics and biological sciences. However, directly predicting the 3-D structure from the primary structure is hard to achieve. Therefore, predicting the fold or structural class of a protein sequence is generally used as an intermediate step in determining the protein's 3-D structure. For protein fold recognition (PFR) and structural class prediction (SCP), two steps are required - feature extraction step and classification step. Feature extraction techniques generally utilize syntactical-based information, evolutionary-based information and physicochemical-based information to extract features. In this study, we explore the importance of utilizing the physicochemical properties of amino acids for improving PFR and SCP accuracies. For this, we propose a Forward Consecutive Search (FCS) scheme which aims to strategically select physicochemical attributes that will supplement the existing feature extraction techniques for PFR and SCP. An exhaustive search is conducted on all the existing 544 physicochemical attributes using the proposed FCS scheme and a subset of physicochemical attributes is identified. Features extracted from these selected attributes are then combined with existing syntactical-based and evolutionary-based features, to show an improvement in the recognition and prediction performance on benchmark datasets. PMID:27164998

  14. Physico-Chemical and Structural Properties of DeNOx and SO2 Oxidation Catalysts

    Masters, Stephen Grenville; Oehlers, Cord; Nielsen, Kurt;

    1996-01-01

    Commercial catalysts for NOx removal and SO2 oxidation and their model systems have been investigated by spectroscopic, thermal, electrochemical and X-ray methods. Structural information on the vanadium complexes and compounds as well as physico-chemical properties for catalyst model systems have...... been obtained. The results are discussed in relation to proposed reaction mechanisms....

  15. The solid phase of ginkgolide K: Structure and physicochemical properties

    Zhang, Yiwen; Zhang, Guoshun; Wang, Zhenzhong; Lv, Yang; Xiao, Wei

    2016-05-01

    Four solvates of ginkgolide K with dimethyl sulfoxide(I), water molecule(II), acetone-isopropyl alcohol(III), methanol-ethanol(IV) and one solvate-free (V) have been described in this work. And the solid-state techniques such as X-ray diffraction, thermal analysis and Fourier transform infrared spectroscopy were used for characterization of the solid phases. The single crystal structures of ginkgolide K solvates (I-IV) have been determined. Ginkgolide K shows strong inflexibility and solvents being incorporated in the crystal structure results in it forming polymorphs via the diverse hydrogen bond interactions.

  16. Synthesis, structure and physicochemical properties of rutherfordite and tetrasodiumuranyltricarbonate

    Optimal methods of UO2CO3 and Na4[UO2(CO3)3] synthesis are developed. By the methods of x-ray diffraction, precision IR spectroscopy and thermography structure of these compounds and the process of their thermal decomposition are studied. Standard formation enthalpy at 298.15 K of crystalline Na4[UO2(CO3)3] (-4010±8.0 kJ/mol) are determined by the reaction calorimetry method

  17. Serum Albumin-Alginate Microparticles Prepared by Transacylation: Relationship between Physicochemical, Structural and Functional Properties.

    Hadef, Imane; Rogé, Barbara; Edwards-Lévy, Florence

    2015-08-10

    Our laboratory develops a method of microencapsulation using a transacylation reaction in a water-in-oil (W/O) emulsion. The method is based on the creation of amide bonds between free amine functions of a protein (human serum albumin (HSA)) and ester groups of propylene glycol alginate (PGA) in the inner aqueous phase after alkalization. The aim of this work is to study the influence of physicochemical properties of HSA-PGA mixtures on microparticle characteristics. Microparticles were prepared varying the concentrations of PGA and HSA, then characterized (inner structure, size, swelling rate, release kinetics). PGA and each polymer mixture used in the microencapsulation procedure were examined in order to elucidate the mechanism of microstructure formation. It was found that the morphology and functional properties of HSA-alginate microparticles were related to the two polymer concentrations in the aqueous solution. Actually, the polymer concentration variations led to physicochemical changes, which affected the microparticle structure and functional properties. PMID:26121308

  18. Physico-chemical properties and cytotoxic effects of sugar-based surfactants: Impact of structural variations.

    Lu, Biao; Vayssade, Muriel; Miao, Yong; Chagnault, Vincent; Grand, Eric; Wadouachi, Anne; Postel, Denis; Drelich, Audrey; Egles, Christophe; Pezron, Isabelle

    2016-09-01

    Surfactants derived from the biorefinery process can present interesting surface-active properties, low cytotoxicity, high biocompatibility and biodegradability. They are therefore considered as potential sustainable substitutes to currently used petroleum-based surfactants. To better understand and anticipate their performances, structure-property relationships need to be carefully investigated. For this reason, we applied a multidisciplinary approach to systematically explore the effect of subtle structural variations on both physico-chemical properties and biological effects. Four sugar-based surfactants, each with an eight carbon alkyl chain bound to a glucose or maltose head group by an amide linkage, were synthesized and evaluated together along with two commercially available standard surfactants. Physico-chemical properties including solubility, Krafft point, surface-tension lowering and critical micellar concentration (CMC) in water and biological medium were explored. Cytotoxicity evaluation by measuring proliferation index and metabolic activity against dermal fibroblasts showed that all surfactants studied may induce cell death at low concentrations (below their CMC). Results revealed significant differences in both physico-chemical properties and cytotoxic effects depending on molecule structural features, such as the position of the linkage on the sugar head-group, or the orientation of the amide linkage. Furthermore, the cytotoxic response increased with the reduction of surfactant CMC. This study underscores the relevance of a methodical and multidisciplinary approach that enables the consideration of surfactant solution properties when applied to biological materials. Overall, our results will contribute to a better understanding of the concomitant impact of surfactant structure at physico-chemical and biological levels. PMID:27137806

  19. Landscape structure and the speed of adaptation

    The role of fragmentation in the adaptive process is addressed. We investigate how landscape structure affects the speed of adaptation in a spatially structured population model. As models of fragmented landscapes, here we simulate the percolation maps and the fractal landscapes. In the latter the degree of spatial autocorrelation can be suited. We verified that fragmentation can effectively affect the adaptive process. The examination of the fixation rates and speed of adaptation discloses the dichotomy exhibited by percolation maps and fractal landscapes. In the latter, there is a smooth change in the pace of the adaptation process, as the landscapes become more aggregated higher fixation rates and speed of adaptation are obtained. On the other hand, in random percolation the geometry of the percolating cluster matters. Thus, the scenario depends on whether the system is below or above the percolation threshold. - Highlights: • The role of fragmentation on the adaptive process is addressed. • Our approach makes the linkage between population genetics and landscape ecology. • Fragmentation affects gene flow and thus influences the speed of adaptation. • The level of clumping determines how the speed of adaptation is influenced

  20. A modular approach to adaptive structures

    A remarkable property of nastic, shape changing plants is their complete fusion between actuators and structure. This is achieved by combining a large number of cells whose geometry, internal pressures and material properties are optimized for a given set of target shapes and stiffness requirements. An advantage of such a fusion is that cell walls are prestressed by cell pressures which increases, decreases the overall structural stiffness, weight. Inspired by the nastic movement of plants, Pagitz et al (2012 Bioinspir. Biomim. 7) published a novel concept for pressure actuated cellular structures. This article extends previous work by introducing a modular approach to adaptive structures. An algorithm that breaks down any continuous target shapes into a small number of standardized modules is presented. Furthermore it is shown how cytoskeletons within each cell enhance the properties of adaptive modules. An adaptive passenger seat and an aircrafts leading, trailing edge is used to demonstrate the potential of a modular approach. (paper)

  1. Structure, physicochemical properties and in vitro fermentation of enzymatically degraded cell wall materials from apples.

    Förster, S; Dongowski, G; Kunzek, H

    2002-06-01

    Cell wall materials (CWM) prepared from apple parenchyma tissue by treatment with commercial enzymes for maceration, mash fermentation and liquefaction were characterised with regard to their composition and structure as well as their physicochemical and physiological properties. Increasing enzymatic degradation of the CWM resulted in growing loss of the pectin matrix, decreasing porosity as well as increasing particle aggregation. Due to these structural alterations the water binding, the viscoelastic properties of the CWM-water-suspensions and the in vitro fermentation, forming short chain fatty acids, were reduced. The investigations showed that interrelations exist between enzymatic treatment and changes of (i) structure and state of matrices (evaluated by means of thermal analysis), (ii) physicochemical properties and (iii) physiological properties. So the application of liquefying enzymes can lead to a complete removal of the pectin matrix, causing an essentially improved thermal stability of the CWM preparation, but strongly reduced water binding and reduced structure-forming properties into the CWM-water-suspensions. The formation of short-chain fatty acids during in vitro fermentation of the CWM preparations by fresh human faeces flora depended on the portion and the state of the pectin matrix and the cellulose network, respectively. PMID:12108214

  2. Inclusion compound of vitamin B6 in {beta}-CD. Physico-chemical and structural investigations

    Borodi, Gheorghe; Kacso, Irina; Farcas, Sorin I; Bratu, Ioan, E-mail: ioan.bratu@itim-cj.r [National Institute for Research and Development of Isotopic and Molecular Technologies, 65-103 Donath, 400293 Cluj-Napoca (Romania)

    2009-08-01

    Structural and physico-chemical characterization of supramolecular assembly of vitamin B6 with {beta}-cyclodextrin ({beta}-CD) prepared by different methods (kneading, co-precipitation and freeze-drying) has been performed by using several spectroscopic techniques (FTIR, {sup 1}H NMR, UV-Vis), powder X-ray diffraction and DSC in order to evidence the inclusion compound formation. An analysis of the chemical shifts observed in the {sup 1}H-NMR spectra and of the vibrational frequency shifts led to the tentative conclusion that the vitamin B6 probably enters the cyclodextrin torus when forming the {beta}-CD-vitamin B6 inclusion complex.

  3. Effect of KGM deacetylation on the physicochemical rheological and structural properties of glucomannan gels.

    Solo de Zaldívar, Beatriz; Tovar, C. A.; Borderías, A. Javier

    2014-01-01

    This paper focuses on the relationship between network structure and physicochemical and rheological properties of aqueous glucomannan dispersions (AGD) as a function of pH, to establish optimal conditions of glucomannan gelation for making restructured seafood products. Various lots of AGD were prepared from 3% (L1) and 5% (L2) konjac glucomannan adding different amounts (0.5-5%) of 0.6N KOH to obtain samples with successively increasing degrees of alkalinity, from pH= 8.9 t...

  4. Effect of γ-irradiation on the physicochemical properties and structure of fish myofibrillar proteins

    The influence of γ-irradiation on physicochemical properties and structures of myofibrillar protein from grass crap exposed to dose up to 10 kGy was investigated. Irradiated samples exhibited decreased emulsifying property and increased surface hydrophobicity. Increasing dose resulted in decreasing free and total sulphydryl groups, decreasing myosin heavy chains in the sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) patterns. This study demonstrated that γ-irradiation decreased the myofibrillar protein ordered structure and generated the crosslinking and provided a possible reference for the identification of irradiated fish products. - Highlights: • Irradiation decreases emulsifying properties of fish myofibrillar protein. • Irradiation caused the decrease of ordered structure of protein molecule. • Irradiation up to 6 kGy distinctly decreases the content of myosin heavy chains. • Irradiation caused an intermolecular crosslinking in the myofibrillar protein

  5. Disciplined structured communications with disciplined runtime adaptation

    Di Giusto, Cinzia; Perez, Jorge A.

    2015-01-01

    Session types offer a powerful type-theoretic foundation for the analysis of structured communications, as commonly found in service-oriented systems. They are defined upon core programming calculi which offer only limited support for expressing requirements related to runtime adaptation. This is un

  6. Adaptive finite element strategies for shell structures

    Stanley, G.; Levit, I.; Stehlin, B.; Hurlbut, B.

    1992-01-01

    The present paper extends existing finite element adaptive refinement (AR) techniques to shell structures, which have heretofore been neglected in the AR literature. Specific challenges in applying AR to shell structures include: (1) physical discontinuities (e.g., stiffener intersections); (2) boundary layers; (3) sensitivity to geometric imperfections; (4) the sensitivity of most shell elements to mesh distortion, constraint definition and/or thinness; and (5) intrinsic geometric nonlinearity. All of these challenges but (5) are addressed here.

  7. Effect of the conditions of structure formation on the physicochemical properties of ozonated shungites

    Emel'Yanova, G. I.; Gorlenko, L. E.; Rozhkova, N. N.; Rumyantseva, M. N.; Lunin, V. V.

    2010-08-01

    It was investigated the influence of ozone on the physicochemical properties of shungites (type 1) (75-98% C) from Nigozero and Chebolaksha deposits (Karelia) formed by hydrothermal (Nigozero) and high-temperature (Chebolaksha) processes. Ozonation was found to affect the specific surface and the total pore volume of shungites considerably. The pore size distribution pattern depends on the volume morphology (texture) of the sample. An increase in the temperature and pressure during the structure formation of shungite (Chebolaksha) led to a shift of the maximum on the distribution pattern towards the formation of mesopores. The size distribution of pores with the dominant contents of micro- and submesopores for both shungites correlated with the basic structural nanoelements of shungite carbon. The peculiarities of the ozonation of shungite nanocarbon found previously (the non-steady state vibrational kinetics of ozonation and the absence of carbon(II) oxide among the reaction products) were confirmed.

  8. Physicochemical properties and starch structure of a rice mutant with reduction of starch paste viscosity

    Variations in starch physicochemical properties and starch structure between the rice low-paste viscosity mutant RSV-1 and its original parent II-32B were investigated. The results indicated that the apparent amylose content (AAC), gel consistency (GC), alkali spreading value (ASV) of mutant RSV-1 were higher than the wild type. However, major parameters of starch paste viscosity in mutant RSV-1 starch, i. e. peak paste viscosity, hot paste viscosity, and cool paste viscosity were significantly lower than those of the original parent. Compared to the original parent, the mutant had a similar peak time, but less energy and longer time needed for gelatinization. The starch manifested C-type crystalline and starch granule in the endosperm were irregular with different diameters. The mutation of the starch structure might play a key role for the decrease of starch paste viscosity in the mutant RSV-1. (authors)

  9. Supramolecular structure of jackfruit seed starch and its relationship with digestibility and physicochemical properties.

    Chen, Jin; Liang, Yi; Li, Xiaoxi; Chen, Ling; Xie, Fengwei

    2016-10-01

    The influence of supramolecular structure on the physicochemical properties and digestibility of jackfruit seed starch (JSS) were investigated. Compared with maize and cassava starches (MS and CS), JSS had smaller granules and higher amylose content (JSS: 24.90%; CS: 16.68%; and MS: 22.42%), which contributed to higher gelatinization temperature (To: 81.11°C) and setback viscosity (548.9mPas). From scanning electron microscopy, the digestion of JSS was observed mainly at the granule surface. Due to its higher crystallinity (JSS: 30.6%; CS: 30.3%; and MS: 27.4%) and more ordered semi-crystalline lamellae, JSS had a high RS content (74.26%) and melting enthalpy (19.61J/g). In other words, the supramolecular structure of JSS extensively determined its digestibility and resistance to heat and mechanical shear treatment. PMID:27312638

  10. Physicochemical and nanotechnological approaches to the design of 'rigid' spatial structures of DNA

    This review focuses on physicochemical and nanotechnological approaches to the design of 'rigid' particles based on double-stranded DNA molecules. The physicochemical methods imply cross-linking of adjacent DNA molecules ordered in quasinematic layers of liquid-crystalline dispersion particles by synthetic nanobridges consisting of alternating molecules of an antibiotic (daunomycin) and divalent copper ions, as well as cross-linking of these molecules as a result of their salting-out in quasinematic layers of liquid-crystalline dispersion particles under the action of lanthanide cations. The nanotechnological approach is based on the insertion of gold nanoparticles into the free space between double-stranded DNA molecules that form quasinematic layers of liquid-crystalline dispersion particles. This gives rise to extended clusters of gold nanoparticles and is accompanied by an enhancement of the interaction between the DNA molecules through gold nanoparticles and by a decrease in the solubility of dispersion particles. These approaches produce integrated 'rigid' DNA-containing spatial structures, which are incompatible with the initial aqueous polymeric solutions and have unique properties. The bibliography includes 116 references

  11. Pentaglyme-K salt binary mixtures: phase behavior, solvate structures, and physicochemical properties.

    Mandai, Toshihiko; Tsuzuki, Seiji; Ueno, Kazuhide; Dokko, Kaoru; Watanabe, Masayoshi

    2015-01-28

    We prepared a series of binary mixtures composed of certain K salts (KX) and pentaglyme (G5) with different salt concentrations and anionic species ([X](-): [(CF3SO2)2N](-) = [TFSA](-), [CF3SO3](-) = [TfO](-), [C4F9SO3](-) = [NfO](-), PF6(-), SCN(-)), and characterized them with respect to their phase diagrams, solvate structures, and physicochemical properties. Their phase diagrams and thermal stability strongly implied the formation of equimolar complexes. Single-crystal X-ray crystallography was performed on certain equimolar complexes, which revealed that G5 molecules coordinate to K(+) cations in a characteristic manner, like 18-crown-6 ether in the crystalline state, irrespective of the paired anions. The solvate structures in the molten state were elucidated by a combination of temperature-dependent Raman spectroscopy and X-ray crystallography. A drastic spectral variation was observed in the [K(G5)1][TfO] Raman spectra, indicating that solvate structures in the crystalline state break apart upon melting. The solvate stability of [K(G5)1]X is closely related to the ion-ion interaction of the parent salts. A stable solvate forms when the ion-dipole interaction between K(+) and G5 overwhelms the ion-ion interaction between K(+) and X(-). Furthermore, the physicochemical properties of certain equimolar mixtures were evaluated. A Walden plot clearly reflects the ionic nature of the molten equimolar complexes. Judging from the structural characteristics and dissociativity, we classified [K(G5)1]X into two groups, good and poor solvate ionic liquids. PMID:25501925

  12. Parallel computations and control of adaptive structures

    Park, K. C.; Alvin, Kenneth F.; Belvin, W. Keith; Chong, K. P. (Editor); Liu, S. C. (Editor); Li, J. C. (Editor)

    1991-01-01

    The equations of motion for structures with adaptive elements for vibration control are presented for parallel computations to be used as a software package for real-time control of flexible space structures. A brief introduction of the state-of-the-art parallel computational capability is also presented. Time marching strategies are developed for an effective use of massive parallel mapping, partitioning, and the necessary arithmetic operations. An example is offered for the simulation of control-structure interaction on a parallel computer and the impact of the approach presented for applications in other disciplines than aerospace industry is assessed.

  13. Adaptive, tolerant and efficient composite structures

    Wiedemann, Martin; Sinapius, Michael (eds.) [German Aerospace Center DLR, Braunschweig (Germany). Inst. of Composite Structures and Adaptive Systems

    2013-07-01

    Polymer composites offer the possibility for functional integration since the material is produced simultaneously with the product. The efficiency of composite structures raises through functional integration. The specific production processes of composites offer the possibility to improve and to integrate more functions thus making the structure more valuable. Passive functions can be improved by combination of different materials from nano to macro scale, i.e. strength, toughness, bearing strength, compression after impact properties or production tolerances. Active functions can be realized by smart materials, i.e. morphing, active vibration control, active structure acoustic control or structure health monitoring. The basis is a comprehensive understanding of materials, simulation, design methods, production technologies and adaptronics. These disciplines together deliver advanced lightweight solutions for applications ranging from mechanical engineering to vehicles, airframe and space structures along the complete process chain. The book provides basics as well as inspiring ideas for engineers working in the field of adaptive, tolerant and robust composite structures.

  14. Changes in crystal structure and physicochemical properties of potato starch treated by induced electric field.

    Li, Dandan; Yang, Na; Jin, Yamei; Zhou, Yuyi; Xie, Zhengjun; Jin, Zhengyu; Xu, Xueming

    2016-11-20

    The effects of induced electric field (IEF) on the crystal structure and physicochemical properties of potato starch were investigated by subjecting identically treated control and electrically-modified samples to the same temperature history. Additionally, a method of combining IEF with heating for efficient modification of native polymer was also proposed. Results showed that the application of IEF at an electric voltage of 75V has a statistically significant effect on starch gelatinization and pasting properties, especially when combined with heating at 50°C. After treatment by the combination method for 96h, the gelatinization temperatures increased, which can be explained by the slight increase in the ratio of 1044/1015cm(-1) and relative crystallinity. Furthermore, IEF reduced granular swelling and therefore contributed to decreasing the peak, breakdown, and setback viscosity of potato starch. This study explores the potential of IEF as innovative technology for starch modification. PMID:27561526

  15. Structural diversity, physicochemical properties and application of imidazolium surfactants: Recent advances.

    Bhadani, Avinash; Misono, Takeshi; Singh, Sukhprit; Sakai, Kenichi; Sakai, Hideki; Abe, Masahiko

    2016-05-01

    The current review covers recent advances on development and investigation of cationic surfactants containing imidazolium headgroup, which are being extensively investigated for their self-aggregation properties and are currently being utilized in various conventional and non-conventional application areas. These surfactants are being used as: soft template for synthesis of mesoporous/microporous materials, drug and gene delivery agent, stabilizing agent for nanoparticles, dispersants for single/multi walled carbon nanotubes, antimicrobial and antifungal agent, viscosity modifiers, preparing nanocomposite materials, stabilizing microemulsions, corrosion inhibitors and catalyst for organic reactions. Recently several structural derivatives of these surfactants have been developed having many interesting physicochemical properties and they have demonstrated enormous potential in the area of nanotechnology, material science and biomedical science. PMID:27063924

  16. Population structure and adaptation in fishes

    Limborg, Morten

    Marine fishes represent a valuable resource for the global economy and food consumption. Accordingly, many species experience high levels of exploitation necessitating effective management plans. However, long term sustainability may be jeopardized from insufficient knowledge about intra-specific......Marine fishes represent a valuable resource for the global economy and food consumption. Accordingly, many species experience high levels of exploitation necessitating effective management plans. However, long term sustainability may be jeopardized from insufficient knowledge about intra......-specific population structure and adaptive divergence. The large population sizes and high migration rates common to most marine fishes impede the differentiating effect of genetic drift, having led to expectations of no population structure and that the occurrence of local adaptation should be rare in these species...... glacial time scales and more recent colonisation of new habitats. Further, strong genetic divergence at several regional scales demonstrated limited connectivity among sea-going and local fjord populations along the Norwegian coast as well as indications for the potential of locally adapted populations in...

  17. Physico-Chemical and Structural Interpretation of Discrete Derivative Indices on N-Tuples Atoms

    Martínez-Santiago, Oscar; Marrero-Ponce, Yovani; Barigye, Stephen J.; Le Thi Thu, Huong; Torres, F. Javier; Zambrano, Cesar H.; Muñiz Olite, Jorge L.; Cruz-Monteagudo, Maykel; Vivas-Reyes, Ricardo; Vázquez Infante, Liliana; Artiles Martínez, Luis M.

    2016-01-01

    This report examines the interpretation of the Graph Derivative Indices (GDIs) from three different perspectives (i.e., in structural, steric and electronic terms). It is found that the individual vertex frequencies may be expressed in terms of the geometrical and electronic reactivity of the atoms and bonds, respectively. On the other hand, it is demonstrated that the GDIs are sensitive to progressive structural modifications in terms of: size, ramifications, electronic richness, conjugation effects and molecular symmetry. Moreover, it is observed that the GDIs quantify the interaction capacity among molecules and codify information on the activation entropy. A structure property relationship study reveals that there exists a direct correspondence between the individual frequencies of atoms and Hückel’s Free Valence, as well as between the atomic GDIs and the chemical shift in NMR, which collectively validates the theory that these indices codify steric and electronic information of the atoms in a molecule. Taking in consideration the regularity and coherence found in experiments performed with the GDIs, it is possible to say that GDIs possess plausible interpretation in structural and physicochemical terms. PMID:27240357

  18. Probabilistic structural analysis of adaptive/smart/intelligent space structures

    Pai, Shantaram S.; Chamis, Christos C.

    1992-01-01

    A three-bay, space, cantilever truss is probabilistically evaluated for adaptive/smart/intelligent behavior. For each behavior, the scatter (ranges) in buckling loads, vibration frequencies, and member axial forces are probabilistically determined. Sensitivities associated with uncertainties in the structure, material and load variables that describe the truss are determined for different probabilities. The relative magnitude for these sensitivities are used to identify significant truss variables that control/classify its behavior to respond as an adaptive/smart/intelligent structure. Results show that the probabilistic buckling loads and vibration frequencies increase for each truss classification, with a substantial increase for intelligent trusses. Similarly, the probabilistic member axial forces reduce for adaptive and intelligent trusses and increase for smart trusses.

  19. Adapting Bayes Network Structures to Non-stationary Domains

    Nielsen, Søren Holbech; Nielsen, Thomas Dyhre

    2008-01-01

    When an incremental structural learning method gradually modifies a Bayesian network (BN) structure to fit a sequential stream of observations, we call the process structural adaptation. Structural adaptation is useful when the learner is set to work in an unknown environment, where a BN is gradu......When an incremental structural learning method gradually modifies a Bayesian network (BN) structure to fit a sequential stream of observations, we call the process structural adaptation. Structural adaptation is useful when the learner is set to work in an unknown environment, where a BN...

  20. Optimization of a sponge cake formulation with inulin as fat replacer: structure, physicochemical, and sensory properties.

    Rodríguez-García, Julia; Puig, Ana; Salvador, Ana; Hernando, Isabel

    2012-02-01

    The effects of several fat replacement levels (0%, 35%, 50%, 70%, and 100%) by inulin in sponge cake microstructure and physicochemical properties were studied. Oil substitution for inulin decreased significantly (P cake structure development during baking. Cryo-SEM micrographs of cake crumbs showed a continuous matrix with embedded starch granules and coated with oil; when fat replacement levels increased, starch granules appeared as detached structures. Cakes with fat replacement up to 70% had a high crumb air cell values; they were softer and rated as acceptable by an untrained sensory panel (n = 51). So, the reformulation of a standard sponge cake recipe to obtain a new product with additional health benefits and accepted by consumers is achieved. Practical Application:  In this study, fat is replaced by inulin in cakes, which is a fiber mainly obtained from chicory roots. Sponge cake formulations with reductions in fat content up to 70% are achieved. These high-quality products can be labeled as "reduced in fat" according to U.S. FDA (2009) and EU regulations (European-Union 2006). PMID:22250810

  1. Adaptive dynamics for physiologically structured population models.

    Durinx, Michel; Metz, J A J Hans; Meszéna, Géza

    2008-05-01

    We develop a systematic toolbox for analyzing the adaptive dynamics of multidimensional traits in physiologically structured population models with point equilibria (sensu Dieckmann et al. in Theor. Popul. Biol. 63:309-338, 2003). Firstly, we show how the canonical equation of adaptive dynamics (Dieckmann and Law in J. Math. Biol. 34:579-612, 1996), an approximation for the rate of evolutionary change in characters under directional selection, can be extended so as to apply to general physiologically structured population models with multiple birth states. Secondly, we show that the invasion fitness function (up to and including second order terms, in the distances of the trait vectors to the singularity) for a community of N coexisting types near an evolutionarily singular point has a rational form, which is model-independent in the following sense: the form depends on the strategies of the residents and the invader, and on the second order partial derivatives of the one-resident fitness function at the singular point. This normal form holds for Lotka-Volterra models as well as for physiologically structured population models with multiple birth states, in discrete as well as continuous time and can thus be considered universal for the evolutionary dynamics in the neighbourhood of singular points. Only in the case of one-dimensional trait spaces or when N = 1 can the normal form be reduced to a Taylor polynomial. Lastly we show, in the form of a stylized recipe, how these results can be combined into a systematic approach for the analysis of the (large) class of evolutionary models that satisfy the above restrictions. PMID:17943289

  2. RNA Structure Duplications and Flavivirus Host Adaptation.

    Villordo, Sergio M; Carballeda, Juan M; Filomatori, Claudia V; Gamarnik, Andrea V

    2016-04-01

    Flaviviruses include a highly diverse group of arboviruses with a global distribution and a high human disease burden. Most flaviviruses cycle between insects and vertebrate hosts; thus, they are obligated to use different cellular machinery for their replication and mount different mechanisms to evade specific antiviral responses. In addition to coding for viral proteins, the viral genome contains signals in RNA structures that govern the amplification of viral components and participate in triggering or evading antiviral responses. In this review, we focused on new information about host-specific functions of RNA structures present in the 3' untranslated region (3' UTR) of flavivirus genomes. Models and conservation patterns of RNA elements of distinct flavivirus ecological groups are revised. An intriguing feature of the 3' UTR of insect-borne flavivirus genomes is the conservation of complex RNA structure duplications. Here, we discuss new hypotheses of how these RNA elements specialize for replication in vertebrate and invertebrate hosts, and present new ideas associating the significance of RNA structure duplication, small subgenomic flavivirus RNA formation, and host adaptation. PMID:26850219

  3. Physico-chemical studies of hardened cement paste structure with micro-reinforcing fibers

    Steshenko, Aleksei, E-mail: steshenko.alexey@gmail.com; Kudyakov, Aleksander; Konusheva, Viktoriya [Tomsk State University of Architecture and Building, 2 Solyanaya Sq., Tomsk, 634003 (Russian Federation)

    2016-01-15

    The results of physico-chemical studies of modified hardened cement paste with micro-reinforcing fibers are given in this article. The goal was to study the reasons of the increase of strength properties of modified hardened cement paste by the method of X-ray diffraction and electron microscopy. It is shown that the use of mineral fibers in the production of cement based material has positive effect on its properties. The study found out that the increase in the strength of the hardened cement paste with micro-reinforcing fibers is due to the increase of the rate of hydration of cement without a significant change in the phase composition in comparison with hardened cement paste without additive. The results of microstructure investigation (of control samples and samples of the reinforced hardened cement paste) have shown that introduction of mineral fibers in the amount of 0.1-2 % by weight of cement provides the structure of the homogeneous microporous material with uniform distribution of the crystalline phase provided by densely packed hydrates.

  4. Physico-chemical studies of hardened cement paste structure with micro-reinforcing fibers

    Steshenko, Aleksei; Kudyakov, Aleksander; Konusheva, Viktoriya

    2016-01-01

    The results of physico-chemical studies of modified hardened cement paste with micro-reinforcing fibers are given in this article. The goal was to study the reasons of the increase of strength properties of modified hardened cement paste by the method of X-ray diffraction and electron microscopy. It is shown that the use of mineral fibers in the production of cement based material has positive effect on its properties. The study found out that the increase in the strength of the hardened cement paste with micro-reinforcing fibers is due to the increase of the rate of hydration of cement without a significant change in the phase composition in comparison with hardened cement paste without additive. The results of microstructure investigation (of control samples and samples of the reinforced hardened cement paste) have shown that introduction of mineral fibers in the amount of 0.1-2 % by weight of cement provides the structure of the homogeneous microporous material with uniform distribution of the crystalline phase provided by densely packed hydrates.

  5. Dengue Virus RNA Structure Specialization Facilitates Host Adaptation

    Villordo, Sergio M.; Filomatori, Claudia V.; Sánchez-Vargas, Irma; Blair, Carol D; Gamarnik, Andrea V.

    2015-01-01

    Many viral pathogens cycle between humans and insects. These viruses must have evolved strategies for rapid adaptation to different host environments. However, the mechanistic basis for the adaptation process remains poorly understood. To study the mosquito-human adaptation cycle, we examined changes in RNA structures of the dengue virus genome during host adaptation. Deep sequencing and RNA structure analysis, together with fitness evaluation, revealed a process of host specialization of RNA...

  6. Calculation of aqueous solubility of crystalline un-ionized organic chemicals and drugs based on structural similarity and physicochemical descriptors.

    Raevsky, Oleg A; Grigor'ev, Veniamin Yu; Polianczyk, Daniel E; Raevskaja, Olga E; Dearden, John C

    2014-02-24

    Solubilities of crystalline organic compounds calculated according to AMP (arithmetic mean property) and LoReP (local one-parameter regression) models based on structural and physicochemical similarities are presented. We used data on water solubility of 2615 compounds in un-ionized form measured at 25±5 °C. The calculation results were compared with the equation based on the experimental data for lipophilicity and melting point. According to statistical criteria, the model based on structural and physicochemical similarities showed a better fit with the experimental data. An additional advantage of this model is that it uses only theoretical descriptors, and this provides means for calculating water solubility for both existing and not yet synthesized compounds. PMID:24456022

  7. In vitro digestibility and changes in physicochemical and structural properties of common buckwheat starch affected by high hydrostatic pressure.

    Liu, Hang; Wang, Lijing; Cao, Rong; Fan, Huanhuan; Wang, Min

    2016-06-25

    High hydrostatic pressure (HHP), a non-thermal processing technology, was applied at 120, 240, 360, 480, and 600MPa to assess its effect on the in vitro digestibility, physicochemical, and structural properties of common buckwheat starch (CBS). HHP treatment resulted in CBS granules with more rough surfaces. With the increasing pressure level, amylose content, pasting temperature, and thermal stability substantially increased and relative crystallinity, hardness, swelling power, and viscosity decreased. At 120-480MPa, HHP did not affect the 'A'-type crystalline pattern of CBS. However, at 600MPa, HHP contributed to a similar 'B'-type pattern. Compared with native starch, HHP-modified CBS samples had lower in vitro hydrolysis, reduced content of rapidly digestible starch, and increased levels of slowly digestible starch and resistant starch. These results revealed that the in vitro digestibility, physicochemical, and structural properties of CBS are effectively modified by HHP. PMID:27083786

  8. On the structural and physicochemical properties of gamma irradiated UHMWPE/silane hybrid

    This study has been carried to investigate the influence of gamma rays on the structural and physicochemical properties of UHMWPE/silane hybrid. UHMWPE was mixed with vinyltriethoxysilane (VTES) and compression molded sheets were irradiated at different doses of gamma rays. Fourier transform infrared spectroscopy indicated the formation of siloxane linkages in hybrids, which were found to be shifted towards lower wave number upon irradiation. The X-ray diffraction patterns showed significant increase in the percentage crystallinity of hybrid upon gamma irradiation, especially at 65 kGy absorbed dose. Scanning electron micrographs showed good consolidation and compaction with no surface defects. Moreover, the rough topography was changed to smooth ripple-like appearance upon γ-irradiation. Thermal analysis revealed that irradiated hybrids exhibited higher onset thermal degradation temperature, peak melting temperature, and crystalline lamellae thickness compared with the water treated hybrid. In addition, the tensile testing confirmed an increase of 41% and 133% in yield strength and Young's modulus in 100 kGy irradiated hybrid respectively than that of water treated hybrid. We hope that the irradiated UHMWPE/silane hybrids can be used in various high-strength applications such as total joint replacements, pickers for textile machinery, lining for coal chutes and dump trucks. - Highlights: • UHMWPE/silane hybrids have been prepared and irradiated using gamma rays. • The structural analysis revealed the formation siloxane linkages in the hybrid. • The crystallinity, thermal stability and mechanical properties of hybrids were improved with irradiation. • The irradiated hybrids can be used in various high-strength applications

  9. On the structural and physicochemical properties of gamma irradiated UHMWPE/silane hybrid

    Shafiq, Muhammad [Advanced Polymer Laboratory, Department of Metallurgy and Materials Engineering, Pakistan Institute of Engineering and Applied Sciences, 45650 Islamabad (Pakistan); Mehmood, Malik Sajjad [Advanced Polymer Laboratory, Department of Metallurgy and Materials Engineering, Pakistan Institute of Engineering and Applied Sciences, 45650 Islamabad (Pakistan); Department of Basic Sciences and Humanities, University of Engineering and Technology, 47050 Taxila (Pakistan); Yasin, Tariq, E-mail: yasintariq@yahoo.com [Advanced Polymer Laboratory, Department of Metallurgy and Materials Engineering, Pakistan Institute of Engineering and Applied Sciences, 45650 Islamabad (Pakistan)

    2013-12-16

    This study has been carried to investigate the influence of gamma rays on the structural and physicochemical properties of UHMWPE/silane hybrid. UHMWPE was mixed with vinyltriethoxysilane (VTES) and compression molded sheets were irradiated at different doses of gamma rays. Fourier transform infrared spectroscopy indicated the formation of siloxane linkages in hybrids, which were found to be shifted towards lower wave number upon irradiation. The X-ray diffraction patterns showed significant increase in the percentage crystallinity of hybrid upon gamma irradiation, especially at 65 kGy absorbed dose. Scanning electron micrographs showed good consolidation and compaction with no surface defects. Moreover, the rough topography was changed to smooth ripple-like appearance upon γ-irradiation. Thermal analysis revealed that irradiated hybrids exhibited higher onset thermal degradation temperature, peak melting temperature, and crystalline lamellae thickness compared with the water treated hybrid. In addition, the tensile testing confirmed an increase of 41% and 133% in yield strength and Young's modulus in 100 kGy irradiated hybrid respectively than that of water treated hybrid. We hope that the irradiated UHMWPE/silane hybrids can be used in various high-strength applications such as total joint replacements, pickers for textile machinery, lining for coal chutes and dump trucks. - Highlights: • UHMWPE/silane hybrids have been prepared and irradiated using gamma rays. • The structural analysis revealed the formation siloxane linkages in the hybrid. • The crystallinity, thermal stability and mechanical properties of hybrids were improved with irradiation. • The irradiated hybrids can be used in various high-strength applications.

  10. Electron-beam processed corn starch: evaluation of physicochemical and structural properties and technical-economic aspects of the processing

    M. Braşoveanu; M. R. Nemţanu; D. Duţă

    2013-01-01

    The properties of starch can be modified by a variety of methods in order to meet desirable technological needs. Electron beam irradiation is able to induce changes in starch properties. The paper deals with investigation of physicochemical and structural modifications of corn starch processed by electron beam up to 50 kGy and evaluation of the technical-economic aspects of starch processing. Paste viscosity, pasting and peak temperatures decreased in a dose-dependent manner, indicating degra...

  11. Identification of multiple physicochemical and structural properties associated with soluble expression of eukaryotic proteins in cell-free bacterial extracts

    AlexanderA.Tokmakov

    2014-01-01

    Bacterial extracts are widely used to synthesize recombinant proteins. Vast data volumes have been accumulated in cell-free expression databases, covering a whole range of existing proteins. It makes possible comprehensive bioinformatics analysis and identification of multiple features associated with protein solubility and aggregation. In the present paper, an approach to identify the multiple physicochemical and structural properties of amino acid sequences associated with soluble expressio...

  12. Towards Computerized Adaptive Assessment Based on Structured Tasks

    Tvarožek, Jozef; Kravcik, Milos; Bieliková, Mária

    2008-01-01

    Tvarožek, J., Kravčík, M., & Bieliková, M. (2008). Towards Computerized Adaptive Assessment Based on Structured Tasks. In W. Nejdl et al. (Eds.), Adaptive Hypermedia and Adaptive Web-Based Systems (pp. 224-234). Springer Berlin / Heidelberg.

  13. Adaptive Control of Flexible Structures Using Residual Mode Filters

    Balas, Mark J.; Frost, Susan

    2010-01-01

    Flexible structures containing a large number of modes can benefit from adaptive control techniques which are well suited to applications that have unknown modeling parameters and poorly known operating conditions. In this paper, we focus on a direct adaptive control approach that has been extended to handle adaptive rejection of persistent disturbances. We extend our adaptive control theory to accommodate troublesome modal subsystems of a plant that might inhibit the adaptive controller. In some cases the plant does not satisfy the requirements of Almost Strict Positive Realness. Instead, there maybe be a modal subsystem that inhibits this property. This section will present new results for our adaptive control theory. We will modify the adaptive controller with a Residual Mode Filter (RMF) to compensate for the troublesome modal subsystem, or the Q modes. Here we present the theory for adaptive controllers modified by RMFs, with attention to the issue of disturbances propagating through the Q modes. We apply the theoretical results to a flexible structure example to illustrate the behavior with and without the residual mode filter. We have proposed a modified adaptive controller with a residual mode filter. The RMF is used to accommodate troublesome modes in the system that might otherwise inhibit the adaptive controller, in particular the ASPR condition. This new theory accounts for leakage of the disturbance term into the Q modes. A simple three-mode example shows that the RMF can restore stability to an otherwise unstable adaptively controlled system. This is done without modifying the adaptive controller design.

  14. Effects of heavy metals and soil physicochemical properties on wetland soil microbial biomass and bacterial community structure.

    Zhang, Chang; Nie, Shuang; Liang, Jie; Zeng, Guangming; Wu, Haipeng; Hua, Shanshan; Liu, Jiayu; Yuan, Yujie; Xiao, Haibing; Deng, Linjing; Xiang, Hongyu

    2016-07-01

    Heavy metals (HMs) contamination is a serious environmental issue in wetland soil. Understanding the micro ecological characteristic of HMs polluted wetland soil has become a public concern. The goal of this study was to identify the effects of HMs and soil physicochemical properties on soil microorganisms and prioritize some parameters that contributed significantly to soil microbial biomass (SMB) and bacterial community structure. Bacterial community structure was analyzed by polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE). Relationships between soil environment and microorganisms were analyzed by correlation analysis and redundancy analysis (RDA). The result indicated relationship between SMB and HMs was weaker than SMB and physicochemical properties. The RDA showed all eight parameters explained 74.9% of the variation in the bacterial DGGE profiles. 43.4% (contain the variation shared by Cr, Cd, Pb and Cu) of the variation for bacteria was explained by the four kinds of HMs, demonstrating HMs contamination had a significant influence on the changes of bacterial community structure. Cr solely explained 19.4% (p<0.05) of the variation for bacterial community structure, and Cd explained 17.5% (p<0.05), indicating Cr and Cd were the major factors related to bacterial community structure changes. PMID:27046142

  15. Structure and physico-chemical properties in mixed aqueoussolution of sodium alkylcarboxylate-alkyltrimethylammoniumbromide

    HUANG, Jian-Bin(黄建滨); ZHAO, Guo-Xi(赵国玺); HE, Xu(何煦); ZHU, Bu-Yao(朱步瑶); FU, Hong-Lan(付宏兰)

    2000-01-01

    The physico-chemical properties of organized assemblies (micelle or vesicle) from sodium alkylcarboxylate-alkyltrimethyl-ammonium bromide mixture have been investigated systematically. In different mixed cationic-anionic surfactant systems, micelles and vesicles can coexist or be transformed into each other on different conditions. The experimental results are explained prelimilarily from the viewpoint of molecular packing geometry. The solubilization of organic compound in the mixed surfactant system was also studied in detail.

  16. Performance Evaluation of Adaptive Filters Structures for Acoustic Echo Cancellation

    Sanjeev Dhull

    2011-05-01

    Full Text Available We have designed and simulated an acoustic echo cancellation system for conferencing. Thissystem is based upon a least-mean-square (LMS adaptive algorithm and uses multi filtertechnique. A comparative study of both structure has been carried out and it is found that thisnew multi-filter converge faster than similar single long adaptive filter.

  17. Physicochemical and Biological Investigation of Different Structures of Carbon Coatings Deposited onto Polyurethane

    Witold Kaczorowski

    2016-01-01

    Full Text Available The aim of this study was to examine the thrombogenic properties of polyurethane that was surface modified with carbon coatings. Physicochemical properties of manufactured coatings were investigated using transmission electron microscopy (TEM, atomic force microscopy (AFM, X-ray Photoelectron Spectroscopy (XPS, Raman spectroscopy and contact angle measurement methods. Samples were examined by the Impact-R method evaluating the level of platelets activation and adhesion of particular blood cell elements. The analysis of antimicrobial resistance against E. coli colonization and viability of endothelial cells showed that polyurethane modified with use of carbon layers constituted an interesting solution for biomedical application.

  18. Structural systems biology perspective on the metabolic impact of physicochemical stress

    Chang, Roger Larken

    2012-01-01

    Due to the relative prevalence and centrality of the proteome, it is unsurprising that a great number of environmental stressors exert pressure on the cell via impacting proteome function. Whether it be in a global sense, as in temperature or pH destabilizing large fractions of the proteome, or in a more local sense, as in the targeting of one or a handful of proteins by an inhibitory compound, it is not possible to understand physicochemical pressures on the cellular system without consideri...

  19. Interactive ion-mediated sap flow regulation in olive and laurel stems: physicochemical characteristics of water transport via the pit structure.

    Jeongeun Ryu

    Full Text Available Sap water is distributed and utilized through xylem conduits, which are vascular networks of inert pipes important for plant survival. Interestingly, plants can actively regulate water transport using ion-mediated responses and adapt to environmental changes. However, ionic effects on active water transport in vascular plants remain unclear. In this report, the interactive ionic effects on sap transport were systematically investigated for the first time by visualizing the uptake process of ionic solutions of different ion compositions (K+/Ca2+ using synchrotron X-ray and neutron imaging techniques. Ionic solutions with lower K+/Ca2+ ratios induced an increased sap flow rate in stems of Olea europaea L. and Laurus nobilis L. The different ascent rates of ionic solutions depending on K+/Ca2+ ratios at a fixed total concentration increases our understanding of ion-responsiveness in plants from a physicochemical standpoint. Based on these results, effective structural changes in the pit membrane were observed using varying ionic ratios of K+/Ca2+. The formation of electrostatically induced hydrodynamic layers and the ion-responsiveness of hydrogel structures based on Hofmeister series increase our understanding of the mechanism of ion-mediated sap flow control in plants.

  20. Structured and Unstructured Cache Models for SMT Domain Adaptation

    Louis, Annie; Webber, Bonnie L.

    2014-01-01

    We present a French to English translation system for Wikipedia biography articles. We use training data from out-of-domain corpora and adapt the system for biographies. We propose two forms of domain adaptation. The first biases the system towards words likely in biographies and encourages repetition of words across the document. Since biographies in Wikipedia follow a regular structure, our second model exploits this structure as a sequence of topic segments, where each segment discusses a ...

  1. Adaptive Distributed Data Structure Management for Parallel CFD Applications

    Frisch, Jerome

    2013-09-01

    Computational fluid dynamics (CFD) simulations require a lot of computing resources in terms of CPU time and memory in order to compute with a reasonable physical accuracy. If only uniformly refined domains are applied, the amount of computing cells is growing rather fast if a certain small resolution is physically required. This can be remedied by applying adaptively refined grids. Unfortunately, due to the adaptive refinement procedures, errors are introduced which have to be taken into account. This paper is focussing on implementation details of the applied adaptive data structure management and a qualitative analysis of the introduced errors by analysing a Poisson problem on the given data structure, which has to be solved in every time step of a CFD analysis. Furthermore an adaptive CFD benchmark example is computed, showing the benefits of an adaptive refinement as well as measurements of parallel data distribution and performance. © 2013 IEEE.

  2. Structural Probability Concepts Adapted to Electrical Engineering

    Steinberg, Eric P.; Chamis, Christos C.

    1994-01-01

    Through the use of equivalent variable analogies, the authors demonstrate how an electrical subsystem can be modeled by an equivalent structural subsystem. This allows the electrical subsystem to be probabilistically analyzed by using available structural reliability computer codes such as NESSUS. With the ability to analyze the electrical subsystem probabilistically, we can evaluate the reliability of systems that include both structural and electrical subsystems. Common examples of such systems are a structural subsystem integrated with a health-monitoring subsystem, and smart structures. Since these systems have electrical subsystems that directly affect the operation of the overall system, probabilistically analyzing them could lead to improved reliability and reduced costs. The direct effect of the electrical subsystem on the structural subsystem is of secondary order and is not considered in the scope of this work.

  3. Morphological, physico-chemical and structural characterization of mucilage isolated from the seeds of Buchanania lanzan Spreng

    Sudarshan Singh

    2014-01-01

    Full Text Available Context: Mucilage isolated from the seeds of Buchanania lanzan a wild Indian plant. This mucilage can be commercially exploited, by evaluating physico-chemical properties of this mucilage. Materials and Methods: Various physico-chemical parameter using scanning electron microscopy (SEM, molecular weight, X-ray diffraction (XRD spectrometry, zeta potential (ZP, Fourier transform infrared (FT-IR spectroscopy and 1D ( 1 H and 13 C nuclear magnetic resonance (NMR have been employed to characterize mucilage in the present study. Results: SEM analysis suggests that the mucilage has irregular particle size. Thermogravimetry analysis suggested that mucilage had good thermal stability with two stage decomposition. The weight-average molecular weight of mucilage was determined to be 4883, by gel permeation chromatography. The XRD pattern of the mucilage indicated a completely amorphous structure. The ZP was obtained 1.56 and −9.49 mV in water and 0.1 N NaCl respectively. The major functional groups identified from FT-IR spectrum include 3459/cm (-OH, 1667/cm (Alkenyl C-H and C = C stretch, 1407/cm (-COO- and 1321/cm (-CH 3 CO. Analysis of mucilage by paper chromatography and 1D NMR indicated the presence of rhamnose, arabinose and fructose. Conclusion: The spectral and chromatography analysis of mucilage indicate that the mucilage is composed of basic sugar moiety such as (arabinose, rhamnose, fructose and mannose as complex carbohydrates.

  4. Gradient-based adaptation of continuous dynamic model structures

    La Cava, William G.; Danai, Kourosh

    2016-01-01

    A gradient-based method of symbolic adaptation is introduced for a class of continuous dynamic models. The proposed model structure adaptation method starts with the first-principles model of the system and adapts its structure after adjusting its individual components in symbolic form. A key contribution of this work is its introduction of the model's parameter sensitivity as the measure of symbolic changes to the model. This measure, which is essential to defining the structural sensitivity of the model, not only accommodates algebraic evaluation of candidate models in lieu of more computationally expensive simulation-based evaluation, but also makes possible the implementation of gradient-based optimisation in symbolic adaptation. The proposed method is applied to models of several virtual and real-world systems that demonstrate its potential utility.

  5. Simulation of Adaptive Kinetic Architectural Structures

    Kirkegaard, Poul Henning

    2010-01-01

    order to obtain the control forces that must be known in order to control the shape of a real variable geometry truss structure. An experimental test of the of the shape control approach has been implemented using VGT truss structure and a low-cost data acquisition system based on the open...

  6. Photocatalysis Activity and Physicochemical Structure of Titanium Dioxide Co-doped with N and B

    YAN Gui-Yang; ZHENG Liu-Ping; LIN Shen; YE Jin-Hua

    2008-01-01

    Titanium dioxide co-doped with N and B was prepared by sol-gel method. The photocatalytic activity was evaluated by the photodegradation of methylene blue under visible light. Its physicochemical properties were characterized by means of UV-Vis DRS, XRD, FT-IR, and XPS. The results indicated that N-B-TiO2 has good activity to the photodegradation of MB. Its decolourizing rate of methylene blue solution goes up to 98.4% under the visible light irradiation with 5 h. The doping nitrogen forms N-Ti-O and boron primarily existing in oxide appears in the N-B-TiO2 sample. They response for visible light of TiO2 was also exploited.

  7. Adaptive, tolerant and efficient composite structures

    Sinapius, Michael

    2013-01-01

    Polymer composites offer the possibility for functional integration since the material is produced simultaneously with the product. The efficiency of composite structures raises through functional integration. The specific production processes of composites offer the possibility to improve and to integrate more functions thus making the structure more valuable. Passive functions can be improved by combination of different materials from nano to macro scale, i.e. strength, toughness, bearing strength, compression after impact properties or production tolerances.  Active functions can be realized by smart materials, i.e. morphing, active vibration control, active structure acoustic control or structure health monitoring. The basis is a comprehensive understanding of materials, simulation, design methods, production technologies and adaptronics. These disciplines together deliver advanced lightweight solutions for applications ranging from mechanical engineering to vehicles, airframe and space structures along ...

  8. Adaptive structures for fixed and rotary wing aircraft

    Martin, Willi; Jänker, Peter; Siemetzki, Markus; Lorkowski, Thomas; Grohmann, Boris; Maier, Rudolf; Maucher, Christoph; Klöppel, Valentin; Enenkl, Bernhard; Roth, Dieter; Hansen, Heinz

    2007-07-01

    Since more than 10 years EADS Innovation Works, which is the corporate research centre of EADS (European Aeronautic Defence and Space Company), is investigating smart materials and adaptive structures for aircraft in cooperation with EADS business units. Focus of research efforts are adaptive systems for shape control, noise reduction and vibration control of both fixed and rotary wing aircraft as well as for lift optimisation of fixed wing aircraft. Two outstanding adaptive systems which have been pushed ahead in cooperation with Airbus Germany and Eurocopter Germany are adaptive servo flaps for helicopter rotor blades and innovative high lift devices for fixed wing aircraft which both were tested in flight for the first time representing world premieres. In this paper various examples of adaptive systems are presented which were developed and realized by EADS in recent years.

  9. Performance Evaluation of Adaptive Filters Structures for Acoustic Echo Cancellation

    Sanjeev Dhull

    2011-05-01

    Full Text Available We have designed and simulated an acoustic echo cancellation system for conferencing. This system is based upon a least-mean-square (LMS adaptive algorithm and uses multi filter technique. A comparative study of both structure has been carried out and it is found that this new multi-filter converge faster than similar single long adaptive filter. Index Terms: LMS,Multiple sub filter ,Echo cancellation

  10. Improved classification of lung cancer tumors based on structural and physicochemical properties of proteins using data mining models.

    R Geetha Ramani

    Full Text Available Detecting divergence between oncogenic tumors plays a pivotal role in cancer diagnosis and therapy. This research work was focused on designing a computational strategy to predict the class of lung cancer tumors from the structural and physicochemical properties (1497 attributes of protein sequences obtained from genes defined by microarray analysis. The proposed methodology involved the use of hybrid feature selection techniques (gain ratio and correlation based subset evaluators with Incremental Feature Selection followed by Bayesian Network prediction to discriminate lung cancer tumors as Small Cell Lung Cancer (SCLC, Non-Small Cell Lung Cancer (NSCLC and the COMMON classes. Moreover, this methodology eliminated the need for extensive data cleansing strategies on the protein properties and revealed the optimal and minimal set of features that contributed to lung cancer tumor classification with an improved accuracy compared to previous work. We also attempted to predict via supervised clustering the possible clusters in the lung tumor data. Our results revealed that supervised clustering algorithms exhibited poor performance in differentiating the lung tumor classes. Hybrid feature selection identified the distribution of solvent accessibility, polarizability and hydrophobicity as the highest ranked features with Incremental feature selection and Bayesian Network prediction generating the optimal Jack-knife cross validation accuracy of 87.6%. Precise categorization of oncogenic genes causing SCLC and NSCLC based on the structural and physicochemical properties of their protein sequences is expected to unravel the functionality of proteins that are essential in maintaining the genomic integrity of a cell and also act as an informative source for drug design, targeting essential protein properties and their composition that are found to exist in lung cancer tumors.

  11. Physicochemical and structural evaluation of alkali extracted chickpea starch as affected by γ-irradiation.

    Bashir, Mudasir; Haripriya, Sundaramoorthy

    2016-08-01

    In this study, starch isolated from chickpea was exposed to gamma-irradiation at 0, 4, 8 and 12kGy doses. The irradiated starches were evaluated for their physicochemical, morphological and pasting properties. The results revealed significant (p≤0.05) reduction in apparent amylose content, swelling power, turbidity, syneresis, L (lightness) value, and pasting parameters whereas solubility and b (yellowness) value increased with increase in irradiation dose. X-ray diffraction showed C-type of crystallographic pattern. Relative crystallinity (RC) of irradiated starches was different at different irradiation doses. Prominent changes were recorded in the FT-IR spectra of irradiated starch samples with respect to intensity and shifting of major bands in specific regions. Analysis of O - H and C - H stretches, bending mode of water and glycoside bonds of irradiated starches revealed marked decrease in their absorbance intensities. Scanning electron microscopy revealed cracking and clumping of starch granules at elevated doses of gamma-irradiation. Radiation doses were negatively correlated to swelling power, pasting parameters (peak viscosity, hold viscosity, final viscosity, setback viscosity and pasting temperature), turbidity, syneresis and apparent amylose content except solubility. PMID:27132882

  12. Guided Adaptive Image Smoothing via Directional Anisotropic Structure Measurement.

    Zang, Yu; Huang, Hua; Zhang, Lei

    2015-09-01

    Image smoothing prefers a good metric to identify dominant structures from textures adaptive of intensity contrast. In this paper, we drop on a novel directional anisotropic structure measurement (DASM) toward adaptive image smoothing. With observations on psychological perception regarding anisotropy, non-periodicity and local directionality, DASM can well characterize structures and textures independent on their contrast scales. By using such measurement as constraint, we design a guided adaptive image smoothing scheme by improving extrema localization and envelopes construction in a structure-aware manner. Our approach can well suppresses the staircase-like artifacts and blur of structures that appear in previous methods, which better suits structure-preserving image smoothing task. The algorithm is performed on a space-filling curve as the reduced domain, so it is very fast and much easy to implement in practice. We make comprehensive comparisons with previous state-of-the-art methods for a variety of applications. Experimental results demonstrate the merit using our DASM as metric to identify structures, and the effectiveness and efficiency of our adaptive image smoothing approach to produce commendable results. PMID:26357284

  13. Adaptive structural vibration control of acoustic deflector

    Ostasevicius, Vytautas; Palevicius, Arvydas; Ragulskis, Minvydas; Dagys, Donatas; Janusas, Giedrius

    2004-06-01

    Vehicle interior acoustics became an important design criterion. Both legal restrictions and the growing demand for comfort, force car manufacturers to optimize the vibro-acoustic behavior of their products. The main source of noise is, of course, the engine, but sometimes some ill-designed cover or other shell structure inside the car resonates and makes unpredicted noise. To avoid this, we must learn the genesis mechanism of such vibrations, having as subject complex 3D shells. The swift development of computer technologies opens the possibility to numerically predict and optimize the vibrations and noises.

  14. Adaptive Control of Truss Structures for Gossamer Spacecraft

    Yang, Bong-Jun; Calise, Anthony J.; Craig, James I.; Whorton, Mark S.

    2007-01-01

    Neural network-based adaptive control is considered for active control of a highly flexible truss structure which may be used to support solar sail membranes. The objective is to suppress unwanted vibrations in SAFE (Solar Array Flight Experiment) boom, a test-bed located at NASA. Compared to previous tests that restrained truss structures in planar motion, full three dimensional motions are tested. Experimental results illustrate the potential of adaptive control in compensating for nonlinear actuation and modeling error, and in rejecting external disturbances.

  15. Block-structured adaptive mesh refinement - theory, implementation and application

    Deiterding, Ralf [ORNL

    2011-01-01

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

  16. Cross-Lingual Adaptation using Structural Correspondence Learning

    Prettenhofer, Peter

    2010-01-01

    Cross-lingual adaptation, a special case of domain adaptation, refers to the transfer of classification knowledge between two languages. In this article we describe an extension of Structural Correspondence Learning (SCL), a recently proposed algorithm for domain adaptation, for cross-lingual adaptation. The proposed method uses unlabeled documents from both languages, along with a word translation oracle, to induce cross-lingual feature correspondences. From these correspondences a cross-lingual representation is created that enables the transfer of classification knowledge from the source to the target language. The main advantages of this approach over other approaches are its resource efficiency and task specificity. We conduct experiments in the area of cross-language topic and sentiment classification involving English as source language and German, French, and Japanese as target languages. The results show a significant improvement of the proposed method over a machine translation baseline, reducing th...

  17. Seasonal changes in phytoplankton community structure in relation to physico-chemical factors in Bukan dam reservoir (northwest Iran)

    Azari, Ali Mohsenpour; MOHEBBI, Fereidun; ASEM, Alireza

    2011-01-01

    This study examines the relationship between phytoplankton population and some important physicochemical variables in the Bukan Dam Reservoir. The sampling was performed monthly from 8 sampling sites from April 2008 to February 2009. Phytoplankton counts were made by inverted microscope. Totally, 55 phytoplankton taxa were identified and included Chlorophyta, Bacillariophyta, Dinophyta, Cyanobacteria, Euglenophyta, Chrysophyta and Cryptophyta. Correlations between some important physicochemic...

  18. The physico-chemical properties and structural characteristics of artificial soil for cut slope restoration in Southwestern China

    Chen, Shunan; Ai, Xiaoyan; Dong, Tengyun; Li, Binbin; Luo, Ruihong; Ai, Yingwei; Chen, Zhaoqiong; Li, Chuanren

    2016-02-01

    Cut slopes are frequently generated by construction work in hilly areas, and artificial soil is often sprayed onto them to promote ecological rehabilitation. The artificial soil properties are very important for effective management of the slopes. This paper uses fractal and moment methods to characterize soil particle size distribution (PSD) and aggregates composition. The fractal dimension (D) showed linear relationships between clay, silt, and sand contents, with coefficients of determination from 0.843 to 0.875, suggesting that using of D to evaluate the PSD of artificial soils is reasonable. The bias (CS) and peak convex (CE) coefficients showed significant correlations with structure failure rate, moisture content, and total porosity, which validated the moment method to quantitatively describe soil structure. Railway slope (RS) soil has lower organic carbon and soil moisture, and higher pH than natural slope soil. Overall, RS exhibited poor soil structure and physicochemical properties, increasing the risk of soil erosion. Hence, more effective management measures should be adopted to promote the restoration of cut slopes.

  19. Parallel computation of geometry control in adaptive truss structures

    Ramesh, A. V.; Utku, S.; Wada, B. K.

    1992-01-01

    The fast computation of geometry control in adaptive truss structures involves two distinct parts: the efficient integration of the inverse kinematic differential equations that govern the geometry control and the fast computation of the Jacobian, which appears on the right-hand-side of the inverse kinematic equations. This paper present an efficient parallel implementation of the Jacobian computation on an MIMD machine. Large speedup from the parallel implementation is obtained, which reduces the Jacobian computation to an O(M-squared/n) procedure on an n-processor machine, where M is the number of members in the adaptive truss. The parallel algorithm given here is a good candidate for on-line geometry control of adaptive structures using attached processors.

  20. Physico-Chemical Structural and Electrical Studies of Cu-Zn Ferrites Synthesized by Novel Chemical Route

    Lohar, K. S.; Patange, S. M.; Mane, D. R.; Shirsath, Sagar E.; Shinde, N. D.; Kulkarni, Nilesh

    The physico-chemical, structural and electrical properties of zinc substituted copper ferrites having the general formula Cu1-xZnxFe2O4 (x=0.0 to x=0.8) have been studied as a function of zinc ion concentration. The sample was prepared by co-precipitation method from corresponding metal sulphates. X-ray diffraction patterns were used to confirm the structure of synthesized samples. The calculated and theoretical values of average lattice constant, tetrahedral bond, tetrahedral edge and unshared octahedral edge were found to increase, while the shared octahedral edge and octahedral bond decrease as the Zn ion concentration increases. The dielectric constant (ε‧) and dielectric loss tangent (tan δ) were measured at a constant frequency 1 kHz as a function of temperature. The dielectric constant and loss tangent were found to increase with rise in temperature. The conduction mechanism in these ferrites is discussed on the basis of electron exchange between Fe2+ and Fe3+ ions. The temperature dependent dc resistivity was carried out in the temperature range 300 to 800 K. The plots of log ρ versus 103/T are linear showing two regions, corresponding to ferrimagnetic and paramagnetic regions.

  1. Decentralized model reference adaptive control of large flexible structures

    Lee, Fu-Ming; Fong, I-Kong; Lin, Yu-Hwan

    1988-01-01

    A decentralized model reference adaptive control (DMRAC) method is developed for large flexible structures (LFS). The development follows that of a centralized model reference adaptive control for LFS that have been shown to be feasible. The proposed method is illustrated using a simply supported beam with collocated actuators and sensors. Results show that the DMRAC can achieve either output regulation or output tracking with adequate convergence, provided the reference model inputs and their time derivatives are integrable, bounded, and approach zero as t approaches infinity.

  2. Adaptive control of large space structures using recursive lattice filters

    Sundararajan, N.; Goglia, G. L.

    1985-01-01

    The use of recursive lattice filters for identification and adaptive control of large space structures is studied. Lattice filters were used to identify the structural dynamics model of the flexible structures. This identification model is then used for adaptive control. Before the identified model and control laws are integrated, the identified model is passed through a series of validation procedures and only when the model passes these validation procedures is control engaged. This type of validation scheme prevents instability when the overall loop is closed. Another important area of research, namely that of robust controller synthesis, was investigated using frequency domain multivariable controller synthesis methods. The method uses the Linear Quadratic Guassian/Loop Transfer Recovery (LQG/LTR) approach to ensure stability against unmodeled higher frequency modes and achieves the desired performance.

  3. Adaptations in Electronic Structure Calculations in Heterogeneous Environments

    Talamudupula, Sai [Iowa State Univ., Ames, IA (United States)

    2011-01-01

    Modern quantum chemistry deals with electronic structure calculations of unprecedented complexity and accuracy. They demand full power of high-performance computing and must be in tune with the given architecture for superior e ciency. To make such applications resourceaware, it is desirable to enable their static and dynamic adaptations using some external software (middleware), which may monitor both system availability and application needs, rather than mix science with system-related calls inside the application. The present work investigates scienti c application interlinking with middleware based on the example of the computational chemistry package GAMESS and middleware NICAN. The existing synchronous model is limited by the possible delays due to the middleware processing time under the sustainable runtime system conditions. Proposed asynchronous and hybrid models aim at overcoming this limitation. When linked with NICAN, the fragment molecular orbital (FMO) method is capable of adapting statically and dynamically its fragment scheduling policy based on the computing platform conditions. Signi cant execution time and throughput gains have been obtained due to such static adaptations when the compute nodes have very di erent core counts. Dynamic adaptations are based on the main memory availability at run time. NICAN prompts FMO to postpone scheduling certain fragments, if there is not enough memory for their immediate execution. Hence, FMO may be able to complete the calculations whereas without such adaptations it aborts.

  4. Correlating microbial community with physicochemical indices and structures of a full-scale integrated constructed wetland system.

    Wu, Yinghai; Han, Rui; Yang, Xunan; Fang, Xiaohang; Chen, Xi; Yang, Di; Zhang, Renduo

    2016-08-01

    Microorganisms play a key role in removal of pollutants in constructed wetlands (CWs). The aim of this study was to investigate the composition and diversity of microbes in a full-scale integrated constructed wetland system and examine how microbial assemblages were shaped by the structures and physicochemical properties of the sediments. The microbial assemblages were determined using 16S rRNA high-throughput sequencing. Results showed that the microbial phenotypes were more diverse in the system than in single CWs. The genera of Zoogloea, Comamonas, Thiobacillus, Nitrosospira, Denitratisoma, Azonexus, and Azospira showed relatively high abundances, which contributed to the removal of organic matter and nitrogen. The interactions among the three CWs in series acted a key role in the increase of phylogenetic diversity and high percentage of shared operational taxonomic units. In the system, some core microbes always existed even with the changing environment. Redox potential and NH4-N were the important factors affecting the overall microbial community patterns. Total organic carbon had a relatively high impact on some denitrifiers. The results from this study should be useful to better understand the microbial mechanism of wastewater treatment in integrated constructed wetland systems. PMID:27100531

  5. Effects of polyelectrolyte hybridization on the crystal structure, physicochemical properties, and electrochemical activity of layered manganese oxide

    Research highlights: → Polyelectrolyte-layered manganate nanohybrids were prepared by reassembling method. → The effect of hybridization on the electrode activity of manganate was investigated. → A lower charge density polymer is a better guest for improving electrode performance. - Abstract: The effects of polyelectrolyte intercalation on the crystal structure, physicochemical properties, and electrode performance of manganese oxide were investigated with intercalative nanohybrids composed of layered manganate nanosheets and polyelectrolytes such as polyethylenimine (PEI), poly(allylamine hydrochloride) (PAH), and poly(diallyldimethyl ammonium) chloride (PDDA). The intercalative hybridization between layered manganate nanosheets and polyelectrolytes was confirmed by X-ray diffraction, field emission-scanning electron microscopy, and FT-IR spectroscopy. N2 adsorption-desorption isotherm analysis clearly demonstrated that the PEI-layered MnO2 nanohybrid showed a larger surface area than the other nanohybrids. According to Mn K-edge X-ray absorption spectroscopy, the PEI-layered MnO2 nanohybrid possessed a lower Mn oxidation state compared with the other nanohybrids, reflecting the electron transfer from Lewis basic amine groups of the PEI to the manganate layers. All the present nanohybrids exhibited pseudocapacitance behavior, suggesting their applicability as electrode for supercapacitor. The PEI-layered MnO2 nanohybrid showed larger capacitances than the PDDA- and PAH-intercalates. The observed superior electrode performance of the former could be understood by a larger surface area and a lower Mn oxidation state of this material.

  6. Physicochemical conditions, metabolites and community structure of the bacterial microbiota in the gut of wood-feeding cockroaches (Blaberidae: Panesthiinae).

    Bauer, Eugen; Lampert, Niclas; Mikaelyan, Aram; Köhler, Tim; Maekawa, Kiyoto; Brune, Andreas

    2015-02-01

    While the gut microbiota of termites and its role in symbiotic digestion have been studied for decades, little is known about the bacteria colonizing the intestinal tract of the distantly related wood-feeding cockroaches (Blaberidae: Panesthiinae). Here, we show that physicochemical gut conditions and microbial fermentation products in the gut of Panesthia angustipennis resemble that of other cockroaches. Microsensor measurements confirmed that all gut compartments were anoxic at the center and had a slightly acidic to neutral pH and a negative redox potential. While acetate dominated in all compartments, lactate and hydrogen accumulated only in the crop. The high, hydrogen-limited rates of methane emission from living cockroaches were in agreement with the restriction of F420-fluorescent methanogens to the hindgut. The gut microbiota of both P. angustipennis and Salganea esakii differed strongly between compartments, with the highest density and diversity in the hindgut, but similarities between homologous compartments of both cockroaches indicated a specificity of the microbiota for their respective habitats. While some lineages were most closely related to the gut microbiota of omnivorous cockroaches and wood- or litter-feeding termites, others have been encountered also in vertebrates, reinforcing the hypothesis that strong environmental selection drives community structure in the cockroach gut. PMID:25764554

  7. A hirshfeld surface analysis, crystal structure and physicochemical characterization of 1-ethylpiperazinium trichlorocadmate(II)

    Soudani, S.; Jeanneau, E.; Jelsch, C.; Lefebvre, F.; Ben Nasr, C.

    2016-07-01

    A novel organic-inorganic hybrid material, C6H15N2CdCl3.H2O, was synthesized, and its structure was determined at room temperature in the monoclinic space group P21/n with the following parameters: a = 10.3829 (17), b = 7.7459 (12), c = 14.905 (2) Å, β = 98.801 (15), and Z = 4. Its crystal structure is characterized by one-dimensional polymeric chains of edge-sharing CdCl5N distorted octahedra. These chains are linked to the water molecules via Osbnd H … Cl hydrogen bonds to form layers parallel to the (b, a + c) plane. The crystal structure was stabilized by an extensive network of Nsbnd H … Cl, Osbnd H … Cl and Nsbnd H … O hydrogen bonds. The differential scanning calorimetry (DSC) reveals that the title compound is stable until 101.6 °C. The optimized geometry parameters, normal mode frequencies, and corresponding vibrational assignments of the present compound were theoretically examined by DFT/B3LYP method with the Lanl2dz basis set. The FT-IR spectrum of the polycrystalline sample was examined and compared to the calculated spectrum. The calculated results showed that the optimized geometry could well reproduce the crystal structure and that the theoretical vibrational frequency values were in good agreement with their experimental counterparts.

  8. Peroxynitrite-induced structural perturbations in human IgG: A physicochemical study.

    Arfat, Mir Yasir; Arif, Zarina; Chaturvedi, Sumit Kumar; Moinuddin; Alam, Khursheed

    2016-08-01

    IgG is an important defence protein. To exhibit optimum function the molecule must maintain its native structure. Peroxynitrite is a potent oxidizing and nitrating agent produced in vivo under pathophysiological conditions. It can oxidize and/or nitrate various amino acids causing changes in the structure and function of proteins. Such proteins may be involved in the pathogenesis of many inflammatory diseases, including rheumatoid arthritis. In the present work, peroxynitrite-induced structural changes in IgG have been studied by UV-visible, fluorescence, CD, FT-IR, DLS spectroscopy and DSC as well as by SDS-PAGE. Peroxynitrite-modified IgG exhibited hyperchromicity at 280 nm, quenching of tryptophan fluorescence, increase in ANS fluorescence, loss of β-sheet, shift in the positions of amide I and amide II bands, appearance of new peak in FT-IR, attachment of nitro residues and increase in melting temperature, compared to native IgG. Furthermore, peroxynitrite-modified IgG exhibited an additional peak at 420 nm, quenching in tyrosine fluorescence and enhancement in dityrosine fluorescence compared to native IgG. Generation of nitrotyrosine, dityrosine and nitrotryptophan was also observed in peroxynitrite-modified IgG. Gross structural changes in IgG caused by peroxynitrite and observed in vitro may favour autoantibodies induction in vivo under similar conditions. PMID:27210739

  9. Adaptive sensor array algorithm for structural health monitoring of helmet

    Zou, Xiaotian; Tian, Ye; Wu, Nan; Sun, Kai; Wang, Xingwei

    2011-04-01

    The adaptive neural network is a standard technique used in nonlinear system estimation and learning applications for dynamic models. In this paper, we introduced an adaptive sensor fusion algorithm for a helmet structure health monitoring system. The helmet structure health monitoring system is used to study the effects of ballistic/blast events on the helmet and human skull. Installed inside the helmet system, there is an optical fiber pressure sensors array. After implementing the adaptive estimation algorithm into helmet system, a dynamic model for the sensor array has been developed. The dynamic response characteristics of the sensor network are estimated from the pressure data by applying an adaptive control algorithm using artificial neural network. With the estimated parameters and position data from the dynamic model, the pressure distribution of the whole helmet can be calculated following the Bazier Surface interpolation method. The distribution pattern inside the helmet will be very helpful for improving helmet design to provide better protection to soldiers from head injuries.

  10. Cytotoxic substances produced by a fungal strain from a sponge: physico-chemical properties and structures.

    Amagata, T; Usami, Y; Minoura, K; Ito, T; Numata, A

    1998-01-01

    Five novel metabolites, trichodenones A-C (1-3), harzialactone A (4) and B (5), have been isolated together with known R-mevalonolactone (6) from the culture broth of a strain of Trichoderma harzianum OUPS-N115 originally separated from the sponge Halichondria okadai. Their structures have been elucidated by spectral evidence. Among them, 1-3 exhibited significant cytotoxicity against cultured P388 cells. PMID:9531985

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

    Deiterding Ralf

    2011-12-01

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

  12. Hybrid adaptive feedforward control of structures to seismic inputs

    Matevosian, Armond

    1996-01-01

    The key conclusions of this research are: 1. The EFXLMS algorithm demonstrated superior performance than the FXLMS algorithm during fast adaptive processes, in particular for non-stationary inputs. 2. Good attenuation of the peak. and root-mean-square (rms) values of the structural responses using the hybrid control system were observed for most of the real accelerograms. It was also observed that the hybrid control system always improved the performance of the passive contr...

  13. Temporal and structural heterogeneities emerging in adaptive temporal networks

    Aoki, Takaaki; Gross, Thilo

    2015-01-01

    We introduce a model of adaptive temporal networks whose evolution is regulated by an interplay between node activity and dynamic exchange of information through links. We study the model by using a master equation approach. Starting from a homogeneous initial configuration, we show that temporal and structural heterogeneities, characteristic of real-world networks, spontaneously emerge. This theoretically tractable model thus contributes to the understanding of the dynamics of human activity and interaction networks.

  14. Temporal and structural heterogeneities emerging in adaptive temporal networks

    Aoki, Takaaki; Rocha, Luis E. C.; Gross, Thilo

    2016-04-01

    We introduce a model of adaptive temporal networks whose evolution is regulated by an interplay between node activity and dynamic exchange of information through links. We study the model by using a master equation approach. Starting from a homogeneous initial configuration, we show that temporal and structural heterogeneities, characteristic of real-world networks, spontaneously emerge. This theoretically tractable model thus contributes to the understanding of the dynamics of human activity and interaction networks.

  15. Adaptive evolvement of information age C4ISR structure

    Yushi Lan; Kebo Deng; Shaojie Mao; Heng Wang; Kan Yi; Ming Lei

    2015-01-01

    Command, control, communication, computing, intel-ligence, surveil ance and reconnaissance (C4ISR) in information age is a complex system whose structure always changes ac-tively or passively during the warfare. Therefore, it is important to optimize the structure, especial y in ambiguous and quick-tempo modern warfare. This paper proposes an adaptive evolvement mechanism for the C4ISR structure to survive the changeable warfare. Firstly, the information age C4ISR structure is defined and modeled based on the complex network theory. Secondly, taking the observe, orient, decide and act (OODA) model into consideration, four kinds of loops in the C4ISR structure are pro-posed and their coefficient of networked effects (CNE) is further defined. Then, the adaptive evolvement mechanisms of the four kinds of loops are presented respectively. Final y, taking the joint air-defense C4ISR as an example, simulation experiments are im-plemented, which validate the evolvement mechanism and show that the information age C4ISR structure has some characteristics of smal-world network and scale-free network.

  16. Physicochemical and structural characteristics of HEU-type zeolitic tuff treated by hydrochloric acid

    MAGDALENA TOMASEVIC-CANOVIC

    2004-04-01

    Full Text Available Samples of natural HEU-type zeolites – clinoptilolite-Ca, from the Novakovici deposit (near Prijedor, Bosnia and Herzegovina were treated with the hydrochloric acid of various concentrations (from 10-3 M to 2 M. Zeolitic tuffs before and after the acid treatment were examined using IR, XRPD, and chemical analyses. The changes in the crystal structure of acid treated samples showed a significant reduction in the crystallinity of zeolitic tuffs (60–70 %, which were effected by hydrochloric acid with concentrations of 1 M and above.

  17. Nonlinear vibration with control for flexible and adaptive structures

    Wagg, David

    2015-01-01

    This book provides a comprehensive discussion of nonlinear multi-modal structural vibration problems, and shows how vibration suppression can be applied to such systems by considering a sample set of relevant control techniques. It covers the basic principles of nonlinear vibrations that occur in flexible and/or adaptive structures, with an emphasis on engineering analysis and relevant control techniques. Understanding nonlinear vibrations is becoming increasingly important in a range of engineering applications, particularly in the design of flexible structures such as aircraft, satellites, bridges, and sports stadia. There is an increasing trend towards lighter structures, with increased slenderness, often made of new composite materials and requiring some form of deployment and/or active vibration control. There are also applications in the areas of robotics, mechatronics, micro electrical mechanical systems, non-destructive testing and related disciplines such as structural health monitoring. Two broader ...

  18. Segmentation of branching vascular structures using adaptive subdivision surface fitting

    Kitslaar, Pieter H.; van't Klooster, Ronald; Staring, Marius; Lelieveldt, Boudewijn P. F.; van der Geest, Rob J.

    2015-03-01

    This paper describes a novel method for segmentation and modeling of branching vessel structures in medical images using adaptive subdivision surfaces fitting. The method starts with a rough initial skeleton model of the vessel structure. A coarse triangular control mesh consisting of hexagonal rings and dedicated bifurcation elements is constructed from this skeleton. Special attention is paid to ensure a topological sound control mesh is created around the bifurcation areas. Then, a smooth tubular surface is obtained from this coarse mesh using a standard subdivision scheme. This subdivision surface is iteratively fitted to the image. During the fitting, the target update locations of the subdivision surface are obtained using a scanline search along the surface normals, finding the maximum gradient magnitude (of the imaging data). In addition to this surface fitting framework, we propose an adaptive mesh refinement scheme. In this step the coarse control mesh topology is updated based on the current segmentation result, enabling adaptation to varying vessel lumen diameters. This enhances the robustness and flexibility of the method and reduces the amount of prior knowledge needed to create the initial skeletal model. The method was applied to publicly available CTA data from the Carotid Bifurcation Algorithm Evaluation Framework resulting in an average dice index of 89.2% with the ground truth. Application of the method to the complex vascular structure of a coronary artery tree in CTA and to MRI images were performed to show the versatility and flexibility of the proposed framework.

  19. Effects of partial hydrolysis and subsequent cross-linking on wheat gluten physicochemical properties and structure.

    Wang, Kaiqiang; Luo, Shuizhong; Cai, Jing; Sun, Qiaoqiao; Zhao, Yanyan; Zhong, Xiyang; Jiang, Shaotong; Zheng, Zhi

    2016-04-15

    The rheological behavior and thermal properties of wheat gluten following partial hydrolysis using Alcalase and subsequent microbial transglutaminase (MTGase) cross-linking were investigated. The wheat gluten storage modulus (G') and thermal denaturation temperature (Tg) were significantly increased from 2.26 kPa and 54.43°C to 7.76 kPa and 57.69°C, respectively, by the combined action of partial hydrolysis (DH 0.187%) and cross-linking. The free SH content, surface hydrophobicity, and secondary structure analysis suggested that an appropriate degree of Alcalase-based hydrolysis allowed the compact wheat gluten structure to unfold, increasing the β-sheet content and surface hydrophobicity. This improved its molecular flexibility and exposed additional glutamine sites for MTGase cross-linking. SEM images showed that a compact 3D network formed, while SDS-PAGE profiles revealed that excessive hydrolysis resulted in high-molecular-weight subunits degrading to smaller peptides, unsuitable for cross-linking. It was also demonstrated that the combination of Alcalase-based partial hydrolysis with MTGase cross-linking might be an effective method for modifying wheat gluten rheological behavior and thermal properties. PMID:26616937

  20. Phytocenotic structure and physico-chemical properties of a small water body in agricultural landscape

    Joanna Sender

    2014-07-01

    Full Text Available Small water bodies, until recently considered as wasteland, are an essential element of the so-called small water retention. Their main use can vary significantly, but they always play a positive role by increasing water resources and enhancing the natural values of the landscape. Moreover, by increasing bio- diversity thanks to plants forming habitats for many species of flora and fauna, small water bodies act as a biofilter, improving water quality. But these small reservoirs belong to the groups of waters that are most exposed to damage, especially within the catchment area. Because of the invaluable role of small farmland water bodies, a study was undertaken to investigate their phytocenotic structure. In addition, an attempt was made to assess the level of threats and to indicate their role in the development of habitat conditions. The investigated reservoir was created in 2007. Before that time, it functioned as a part of the Zemborzycki reservoir, as they were close to each other. Almost the entire surrounding of this small reservoir consisted of farmland. In 2011 a revitalization project was carried out in the reservoir. Plants typical for wetland habitats were mainly introduced, while synanthropic vegetation was removed. Based on chemical and physical analyses, it can be concluded that the investigated reservoir serves as a natural biofilter thanks to the qualitative and quantitative changes in the structure of macrophytes. After the revitalization project, the investigated pond gained new aesthetic and ecological qualities.

  1. Recrystallization of starches by hydrothermal treatment: digestibility, structural, and physicochemical properties.

    Trinh, Khanh Son

    2015-12-01

    Gelatinized starches were recrystallized under hydrothermal treatment and their properties were characterized by X-ray diffractometry, solid-state (13)C cross-polarization and magic-angle spinning nuclear magnetic resonance, differential scanning calorimetry, gel-permeation chromatography, high-performance anion-exchange chromatography using pulsed amperomeric detection, high-performance size-exclusion chromatography with attached multiangle laser light scattering and refractive index detectors, and digestibility analysis. Amylopectin molecules of hylon (V, VII) and water yam starch contained long side-chains with high proportion of fb1 and fb2. Under hydrothermal treatment, the double helix proportion and relative crystallinity significantly increased and reached maxima of water yam (48.7 and 28.2 %, respectively). Except water yam starch, X-ray diffraction pattern of all starches exhibited the evidence of type 2 amylose-lipid complex. Besides, under DSC measurement, potato and hylon starches showed the endotherm of amylose-amylose interaction. The hydrothermal treatment caused the recrystallization resulting in the decrease of RDS, especially in case of hylon and water yam starch. HTT water yam contained highest SDS (48.3 %) and HTT hylon VII contained highest RS (44.5 %). The relationship between structure and digestibility was observed, in which, high amylose content and specific structures of amylopectin molecule were necessary for the production of RS and/or SDS of hydrothermally treated starches. PMID:26604340

  2. Heterogeneity of Physico-Chemical Properties in Structured Soils and Its Consequences

    E. JASINSKA; H. WETZEL; T. BAUMGARTL; R. HORN

    2006-01-01

    Structured soils are characterized by the presence of inter- and intra-aggregate pore systems and aggregates, which show varying chemical, physical, and biological properties depending on the aggregate type and land use system. How far these aspects also affect the ion exchange processes and to what extent the interaction between the carbon distribution and kind of organic substances affect the internal soil strength as well as hydraulic properties like wettability are still under discussion. Thus, the objective of this research was to clarify the effect of soil aggregation on physical and chemical properties of structured soils at two scales: homogenized material and single aggregates. Data obtained by sequentially peeling off soil aggregates layers revealed gradients in the chemical composition from the aggregate surface to the aggregatecore. In aggregates from long term untreated forest soils we found lower amounts of carbon in the external layer, while in arable soils the differentiation was not pronounced. However, soil aggregates originating from these sites exhibited a higher concentration of microbial activity in the outer aggregate layer and declined towards the interior. Furthermore,soil depth and the vegetation type affected the wettability. Aggregate strength depended on water suction and differences in tillage treatments.

  3. Polymeric Thin Films for Organic Electronics: Properties and Adaptive Structures

    Bruno Pignataro

    2013-03-01

    Full Text Available This review deals with the correlation between morphology, structure and performance of organic electronic devices including thin film transistors and solar cells. In particular, we report on solution processed devices going into the role of the 3D supramolecular organization in determining their electronic properties. A selection of case studies from recent literature are reviewed, relying on solution methods for organic thin-film deposition which allow fine control of the supramolecular aggregation of polymers confined at surfaces in nanoscopic layers. A special focus is given to issues exploiting morphological structures stemming from the intrinsic polymeric dynamic adaptation under non-equilibrium conditions.

  4. Models Adaptation of Complex Objects Structure Dynamics Control

    Sokolov, B. V.; Zelentsov, V. A.; Brovkina, Olga; Mochalov, V. F.; Potryasaev, S. A.

    Cham: Springer, 2015 - (Šilhavý, R.; Šenkeřík, R.; Komínková-Oplatková, Z.; Prokopová, Z.; Šilhavý, P.), s. 21-33. (Intelligent Systems in Cybernetics and Automation Theory . 348). ISBN 978-3-319-18502-6. ISSN 2194-5357. [Computer Science On-line Conference /4./. Zlín (CZ), 27.04.2015-30.04.2015] Institutional support: RVO:67179843 Keywords : complex technical * organizational system * structure dynamic control * planning and scheduling * parametric and structure adaptation of models Subject RIV: EH - Ecology, Behaviour

  5. Structural elucidation and physicochemical properties of mononuclear Uranyl(VI) complexes incorporating dianionic units.

    Azam, Mohammad; Velmurugan, Gunasekaran; Wabaidur, Saikh Mohammad; Trzesowska-Kruszynska, Agata; Kruszynski, Rafal; Al-Resayes, Saud I; Al-Othman, Zeid A; Venuvanalingam, Ponnambalam

    2016-01-01

    Two derivatives of organouranyl mononuclear complexes [UO2(L)THF] (1) and [UO2(L)Alc] (2), where L = (2,2'-(1E,1'E)-(2,2-dimethylpropane-1,3-dyl)bis(azanylylidene, THF = Tetrahydrofuran, Alc = Alcohol), have been prepared. These complexes have been determined by elemental analyses, single crystal X-ray crystallography and various spectroscopic studies. Moreover, the structure of these complexes have also been studied by DFT and time dependent DFT measurements showing that both the complexes have distorted pentagonal bipyramidal environment around uranyl ion. TD-DFT results indicate that the complex 1 displays an intense band at 458.7 nm which is mainly associated to the uranyl centered LMCT, where complex 2 shows a band at 461.8 nm that have significant LMCT character. The bonding has been further analyzed by EDA and NBO. The photocatalytic activity of complexes 1 and 2 for the degradation of rhodamine-B (RhB) and methylene blue (MB) under the irradiation of 500W Xe lamp has been explored, and found more efficient in presence of complex 1 than complex 2 for both dyes. In addition, dye adsorption and photoluminescence properties have also been discussed for both complexes. PMID:27595801

  6. Structural, physicochemical characterization and antimicrobial activities of a new Tetraaqua bismaleato Iron(II) complex

    Badiaa Essghaier; Jawher Abdelhak; Amani Naouar; Nourchene Toukebri; Mohamed Faouzi Zid; Najla Sadfi-Zouaoui

    2015-12-01

    Tetraaqua bismaleato iron(II) [Fe(C4H3O4)2 (H2O)4], (1) is a new synthetic antimicrobial agent. Thermal analysis shows that the dehydration of the compound occurs in agreement with the structure. The single crystal salt crystallizes in the triclinic space group -1 with = 5.171(2) Å, = 7.309(3) Å, = 9.731(3) Å, = 109.15(2)°, = 115.02(2)°, = 92.42(1)°, = 313.6(3) Å3 and Z = 1. Three dimensional network is formed by strong intermolecular O – H . . . O hydrogen bonds. Magnetic susceptibility measurements of 1 in the range 2–300 K exhibited paramagnetic behavior at high temperature. However, at low temperature, the susceptibility data showed weak antiferromagnetic interactions between the local spins. Antimicrobial activity of 1 was tested. It showed high response against gram-positive and gram-negative bacteria as well as fungi and the MIC and IC50 values ranged from 8 to 256 g.mL−1 and from 1.38 to 22.19 g.mL−1, respectively.

  7. Structural and physicochemical characteristics of a novel water-soluble gum from Lallemantia royleana seed.

    Razavi, Seyed Mohammad Ali; Cui, Steve W; Ding, Huihuang

    2016-02-01

    In this study, the structural information (monosaccharide compositions, molecular weight parameters & FTIR analysis), chemical composition (moisture, protein, ash, carbohydrate & uronic acids), rheological properties, and surface activity of Lallemantia royleana seeds mucilage (BSG) were determined. The results showed BSG contains 8.51% (w.b.) moisture, 8.24% (d.b.) ash, 2.71% (d.b.) protein, 75.87% (d.b.) carbohydrate and 20.33% (d.b.) uronic acids. Monosaccharide analysis revealed the presence of arabinose (37.88%), galactose (33.54%), rhamnose (18.44%), xylose (6.02%) and glucose (4.11%) in the BSG polysaccharide. Although BSG had similar molecular weight (1.294×10(6) Da) compared to most seed gums, the intrinsic viscosity (23.06 dL/g) and gyration radius (104.84 nm) were higher. The BSG exhibited a strong shear-thinning behavior (n<0.29) over the shear rate range of 0.01 to 1000 s(-1). Flow behavior data was correlated with different time-independent models, which provided a good description of BSG rheological properties. Dynamic mechanical spectra demonstrated BSG is a typical of weak gel, which its rheological parameters were superior to those of many commercial gums. The FTIR spectra of the BSG polymer showed the presence of carboxyl groups, which may serve as binding sites for ions. BSG exhibited the ability to reduce the surface tension of water at concentrations lower than 0.75%. PMID:26645141

  8. Structural and physicochemical characterization of Sphenostylis stenocarpa (Hochst. ex A. Rich.) Harms tuber starch.

    Malumba, Paul; Bungu, Mulombo Denis; Katanga, Kabalevi Joseph; Doran, Lynn; Danthine, Sabine; Béra, François

    2016-12-01

    Several characteristics of African Yam Bean tuber starch (AYB) were studied and compared with that of a well-known native potato starch (P). The diameter of AYB granules ranged from 5.7μ to 49μ with a median at 19.5μ. During its pasting, AYB exhibited a low peak of viscosity in accordance with its low granules swelling and disintegration capacity. The gelatinization temperature of AYB was 75.2°C while that of P was 60.4°C. AYB was observed to be more stable during thermo-gravimetrical Analysis. Its degradation peak was observed at 308°C while that of P was 303°C. The X-ray diffraction analysis revealed that AYB belongs to the A-type crystalline group instead of C-type as claimed for several legumes starches. The stability of AYB and its capacity to structure starch-water systems make this resource an interesting ingredient for new food and non-food products. PMID:27374537

  9. Polyelectrolyte complexes via desalting mixtures of hyaluronic acid and chitosan-Physicochemical study and structural analysis.

    Lalevée, G; Sudre, G; Montembault, A; Meadows, J; Malaise, S; Crépet, A; David, L; Delair, T

    2016-12-10

    Polyelectrolyte complexes (PECs) were prepared from Chitosan (CS) and Hyaluronic Acid (HYA) homogeneous mixtures of aqueous solutions. The method consisted of preparing a homogeneous mixture of the two polysaccharides via charge screening at high salt concentrations. Then, the mixture was dialyzed, leading to the controlled self-assembly of the two polyelectrolytes. Critical parameters like the chitosan degree of acetylation (DA) and molar mass (Mw), the residual salt concentration and the molar charge ratio r=nNH3(+) (CS)/nCOO(-) (HYA) accounted for the transition from homogeneous aqueous solutions to colloidal suspensions (r=0.1) or gel coacervates (r=0.5). The influence of the DA and Mw of CS was evaluated by visual observations, light scattering and rheological measurements. For low values of r, Small Angle X-ray Scattering (SAXS) experiments revealed that the HYA nanostructure was weakly affected by the presence of PECs. On the contrary, the structure was impacted when increasing r, revealing a heterogeneous aggregate morphology with ladder-like chain interactions. PMID:27577900

  10. Electronic and physico-chemical properties of nanometric boron delta-doped diamond structures

    Chicot, G., E-mail: gauthier.chicot@neel.cnrs.fr; Fiori, A.; Tran Thi, T. N.; Bousquet, J.; Delahaye, J.; Grenet, T.; Eon, D.; Omnès, F.; Bustarret, E. [Université Grenoble Alpes, Institut NEEL, 38042 Grenoble (France); CNRS, Institut NEEL, 38042 Grenoble (France); Volpe, P. N.; Tranchant, N.; Mer-Calfati, C.; Arnault, J. C. [CEA, LIST, Diamond Sensors Laboratory, 91191 Gif-sur-Yvette (France); Gerbedoen, J. C.; Soltani, A.; De Jaeger, J. C. [IEMN, UMR-CNRS 8520, Avenue Poincaré, Université de Lille 1, 59652 Villeneuve d' Ascq (France); Alegre, M. P.; Piñero, J. C.; Araújo, D. [Dpto Ciencia de los Materiales, Facultad de Ciencias, Universidad de Cádiz, 11510 Puerto Real (Cádiz) (Spain); Jomard, F. [Groupe d' Étude de la Matière Condensée (GEMaC), UMR 8635 du CNRS, UVSQ, 45 Avenue des États-Unis, 78035 Versailles Cedex (France); and others

    2014-08-28

    Heavily boron doped diamond epilayers with thicknesses ranging from 40 to less than 2 nm and buried between nominally undoped thicker layers have been grown in two different reactors. Two types of [100]-oriented single crystal diamond substrates were used after being characterized by X-ray white beam topography. The chemical composition and thickness of these so-called delta-doped structures have been studied by secondary ion mass spectrometry, transmission electron microscopy, and spectroscopic ellipsometry. Temperature-dependent Hall effect and four probe resistivity measurements have been performed on mesa-patterned Hall bars. The temperature dependence of the hole sheet carrier density and mobility has been investigated over a broad temperature range (6 K < T < 450 K). Depending on the sample, metallic or non-metallic behavior was observed. A hopping conduction mechanism with an anomalous hopping exponent was detected in the non-metallic samples. All metallic delta-doped layers exhibited the same mobility value, around 3.6 ± 0.8 cm{sup 2}/Vs, independently of the layer thickness and the substrate type. Comparison with previously published data and theoretical calculations showed that scattering by ionized impurities explained only partially this low common value. None of the delta-layers showed any sign of confinement-induced mobility enhancement, even for thicknesses lower than 2 nm.

  11. Ferrocenyl-substituted Schiff base complexes of boron: Synthesis, structural, physico-chemical and biochemical aspects

    Yadav, Sunita; Singh, R. V.

    2011-01-01

    Biological important complexes of boron(III) derived from 1-acetylferrocenehydrazinecarboxamide (L 1H), 1-acetylferrocenehydrazinecarbothioamide (L 2H) and 1-acetylferrocene carbodithioic acid (L 3H) have been prepared and investigated using a combination of microanalytical analysis, melting point, electronic, IR, 1H NMR and 13C NMR spectral studies, cyclic voltammetry and X-ray powder diffraction studies. Boron isopropoxide interacts with the ligands in 1:1, 1:2 and 1:3 molar ratios (boron:ligand) resulting in the formation of coloured products. On the basis of conductance and spectral evidences, tetrahedral structures for boron(III) complexes have been assigned. The ligands are coordinated to the boron(III) via the azomethine nitrogen atom and the thiolic sulfur atom/enolic oxygen atom. On the basis of X-ray powder diffraction study one of the representative boron complex was found to have orthorhombic lattice, having lattice parameters: a = 9.9700, b = 15.0000 and c = 7.0000. Both the ligands and their complexes have been screened for their biological activity on several pathogenic fungi and bacteria and were found to possess appreciable fungicidal and bactericidal properties. Plant growth regulating activity of one of the ligand and its complexes has also been recorded on gram plant, and results have been discussed.

  12. Electronic and physico-chemical properties of nanometric boron delta-doped diamond structures

    Heavily boron doped diamond epilayers with thicknesses ranging from 40 to less than 2 nm and buried between nominally undoped thicker layers have been grown in two different reactors. Two types of [100]-oriented single crystal diamond substrates were used after being characterized by X-ray white beam topography. The chemical composition and thickness of these so-called delta-doped structures have been studied by secondary ion mass spectrometry, transmission electron microscopy, and spectroscopic ellipsometry. Temperature-dependent Hall effect and four probe resistivity measurements have been performed on mesa-patterned Hall bars. The temperature dependence of the hole sheet carrier density and mobility has been investigated over a broad temperature range (6 K 2/Vs, independently of the layer thickness and the substrate type. Comparison with previously published data and theoretical calculations showed that scattering by ionized impurities explained only partially this low common value. None of the delta-layers showed any sign of confinement-induced mobility enhancement, even for thicknesses lower than 2 nm

  13. Learning Unknown Structure in CRFs via Adaptive Gradient Projection Method

    Wei Xue

    2016-08-01

    Full Text Available We study the problem of fitting probabilistic graphical models to the given data when the structure is not known. More specifically, we focus on learning unknown structure in conditional random fields, especially learning both the structure and parameters of a conditional random field model simultaneously. To do this, we first formulate the learning problem as a convex minimization problem by adding an l_2-regularization to the node parameters and a group l_1-regularization to the edge parameters, and then a gradient-based projection method is proposed to solve it which combines an adaptive stepsize selection strategy with a nonmonotone line search. Extensive simulation experiments are presented to show the performance of our approach in solving unknown structure learning problems.

  14. Adaptive symbiotic organisms search (SOS algorithm for structural design optimization

    Ghanshyam G. Tejani

    2016-07-01

    Full Text Available The symbiotic organisms search (SOS algorithm is an effective metaheuristic developed in 2014, which mimics the symbiotic relationship among the living beings, such as mutualism, commensalism, and parasitism, to survive in the ecosystem. In this study, three modified versions of the SOS algorithm are proposed by introducing adaptive benefit factors in the basic SOS algorithm to improve its efficiency. The basic SOS algorithm only considers benefit factors, whereas the proposed variants of the SOS algorithm, consider effective combinations of adaptive benefit factors and benefit factors to study their competence to lay down a good balance between exploration and exploitation of the search space. The proposed algorithms are tested to suit its applications to the engineering structures subjected to dynamic excitation, which may lead to undesirable vibrations. Structure optimization problems become more challenging if the shape and size variables are taken into account along with the frequency. To check the feasibility and effectiveness of the proposed algorithms, six different planar and space trusses are subjected to experimental analysis. The results obtained using the proposed methods are compared with those obtained using other optimization methods well established in the literature. The results reveal that the adaptive SOS algorithm is more reliable and efficient than the basic SOS algorithm and other state-of-the-art algorithms.

  15. Direct Adaptive Aircraft Control Using Dynamic Cell Structure Neural Networks

    Jorgensen, Charles C.

    1997-01-01

    A Dynamic Cell Structure (DCS) Neural Network was developed which learns topology representing networks (TRNS) of F-15 aircraft aerodynamic stability and control derivatives. The network is integrated into a direct adaptive tracking controller. The combination produces a robust adaptive architecture capable of handling multiple accident and off- nominal flight scenarios. This paper describes the DCS network and modifications to the parameter estimation procedure. The work represents one step towards an integrated real-time reconfiguration control architecture for rapid prototyping of new aircraft designs. Performance was evaluated using three off-line benchmarks and on-line nonlinear Virtual Reality simulation. Flight control was evaluated under scenarios including differential stabilator lock, soft sensor failure, control and stability derivative variations, and air turbulence.

  16. Adaptive Color Calibration Based One-Shot Structured Light System

    Jie Yuan

    2012-08-01

    Full Text Available In one-shot color structured light systems, the color of stripe patterns are typically distorted with respect to color crosstalk, ambient light and the albedo of the scanned objects, leading to mismatch in the correspondence of color stripes between the projected and captured images. In this paper, an adaptive color calibration and Discrete Trend Transform algorithm are presented to achieve high-resolution 3D reconstructions. The adaptive color calibration, according to the relative albedo in RGB channels, can improve the accuracy of labeling stripe by alleviating the effect of albedo and ambient light while decoding the color. Furthermore, the Discrete Trend Transform in the M channel makes the color calibration an effective method for detecting weak stripes due to the uneven surfaces or reflectance characteristics of the scanned objects. With this approach, the presented system is suitable for scanning moving objects and generating high-resolution 3D reconstructions without the need of dark laboratory environments.

  17. Self-Adaptive Stepsize Search Applied to Optimal Structural Design

    Nolle, L.; Bland, J. A.

    Structural engineering often involves the design of space frames that are required to resist predefined external forces without exhibiting plastic deformation. The weight of the structure and hence the weight of its constituent members has to be as low as possible for economical reasons without violating any of the load constraints. Design spaces are usually vast and the computational costs for analyzing a single design are usually high. Therefore, not every possible design can be evaluated for real-world problems. In this work, a standard structural design problem, the 25-bar problem, has been solved using self-adaptive stepsize search (SASS), a relatively new search heuristic. This algorithm has only one control parameter and therefore overcomes the drawback of modern search heuristics, i.e. the need to first find a set of optimum control parameter settings for the problem at hand. In this work, SASS outperforms simulated-annealing, genetic algorithms, tabu search and ant colony optimization.

  18. A structure-based approach to evaluation product adaptability in adaptable design

    Adaptable design, as a new design paradigm, involves creating designs and products that can be easily changed to satisfy different requirements. In this paper, two types of product adaptability are proposed as essential adaptability and behavioral adaptability, and through measuring which respectively a model for product adaptability evaluation is developed. The essential adaptability evaluation proceeds with analyzing the independencies of function requirements and function modules firstly based on axiomatic design, and measuring the adaptability of interfaces secondly with three indices. The behavioral adaptability reflected by the performance of adaptable requirements after adaptation is measured based on Kano model. At last, the effectiveness of the proposed method is demonstrated by an illustrative example of the motherboard of a personal computer. The results show that the method can evaluate and reveal the adaptability of a product in essence, and is of directive significance to improving design and innovative design

  19. Adaptive polyphase subband decomposition structures for image compression.

    Gerek, O N; Cetin, A E

    2000-01-01

    Subband decomposition techniques have been extensively used for data coding and analysis. In most filter banks, the goal is to obtain subsampled signals corresponding to different spectral regions of the original data. However, this approach leads to various artifacts in images having spatially varying characteristics, such as images containing text, subtitles, or sharp edges. In this paper, adaptive filter banks with perfect reconstruction property are presented for such images. The filters of the decomposition structure which can be either linear or nonlinear vary according to the nature of the signal. This leads to improved image compression ratios. Simulation examples are presented. PMID:18262904

  20. Decentralized adaptive generalized predictive control for structural vibration

    LU Minyue; GU Zhongquan

    2005-01-01

    A decentralized generalized predictive control (GPC) algorithm is developed for strongly coupled multi-input multi-output systems with parallel computation. The algorithm is applied to adaptive control of structural vibration. The key steps in this algorithm are to group the actuators and the sensors and then to pair these groups into subsystems. It is important that the on-line identification and the control law design can be a parallel process for all these subsystems. It avoids the high computation cost in ordinary predictive control,and is of great advantage especially for large-scale systems.

  1. Exploring Structural and Physicochemical Profiles of Potential GSK-3β Inhibitors Using Structure- and Ligand-Based Modeling Studies.

    Hossain, Tabassum; Saha, Achintya; Mukherjee, Arup

    2016-01-01

    Glycogen synthase kinase-3β (GSK-3β) is a promising target for therapeutic invasion of Alzheimer's disease (AD). The kinase enzyme plays major role in pathological process for the formation of β-amyloid plaques and neurofibrillary tangles in AD. In the present study, structure-based pharmacophore and ligand-based 3D QSAR, HQSAR and pharmacophore mapping studies have been emphasized to explore the possible structural requirement of this potential kinase inhibitors using a structurally diverse set of compounds. The developed models were validated with the interaction study at the catalytic cleft. The 3D QSAR studies yield robust models of CoMFA R(2) = 0.965, se = 0.212, Q(2) = 0.525, R(2)pred = 0.709, r(2)m = 0.579 and CoMSIA: R(2) = 0.935, se = 0.289, Q(2) = 0.581, R(2)pred = 0.723, r(2)m = 0.935, that explain the importance of steric, electrostatic, hydrogen bond (HB) acceptor of the molecule for inhibition of GSK-3β. The HQSAR study (R(2) = 0.871, se = 0.400, Q(2) = 0.639, R(2)pred = 0.721, r(2)m = 0.664) indicated the fragments of the molecular fingerprints that might be important for inhibition. Both structure- and ligand-based pharmacophore mapping proposed that acceptor and donor features of the molecule are essential for receptor-ligand interactions. Molecular diversity provides an opportunity on wide range of applicability for the GSK-3β inhibitors, and depicts information on the structural and properties requirement for effective binding at the active site selectivity that minimize the side effects with therapeutic benefits. PMID:27064095

  2. Adaptive base-isolation of civil structures using variable amplification

    Kenneth K. Walsh; Makola M. Abdullah

    2006-01-01

    Semi-active dampers are used in base-isolation to reduce the seismic response of civil engineering structures.In the present study, a new semi-active damping system using variable amplification will be investigated for adaptive baseisolation. It uses a novel variable amplification device (VAD) connected in series with a passive damper. The VAD is capable of producing multiple amplification factors, each corresponding to a different amplification state. Forces from the damper are amplified to the structure according to the current amplification state, which is selected via a semi-active control algorithm specifically tailored to the system's unique damping characteristics. To demonstrate the effectiveness of the VAD-damper system for adaptive base-isolation, numerical simulations are conducted for three and seven-story base-isolated buildings subject to both far and near-field ground motions. The results indicate that the system can achieve significant reductions in response compared to the base-isolated buildings with no damper. The proposed system is also found to perform well compared to a typical semi-active damper.

  3. Novel MRE/CFRP sandwich structures for adaptive vibration control

    Kozlowska, J.; Boczkowska, A.; Czulak, A.; Przybyszewski, B.; Holeczek, K.; Stanik, R.; Gude, M.

    2016-03-01

    The aim of this work was the development of sandwich structures formed by embedding magnetorheological elastomers (MRE) between constrained layers of carbon fibre-reinforced plastic (CFRP) laminates. The MREs were obtained by mechanical stirring of a reactive mixture of substrates with carbonyl-iron particles, followed by orienting the particles into chains under an external magnetic field. Samples with particle volume fractions of 11.5% and 33% were examined. The CFRP/MRE sandwich structures were obtained by compressing MREs samples between two CFRP laminates composed. The used A.S.SET resin was in powder form and the curing process was carried out during pressing with MRE. The microstructure of the manufactured sandwich beams was inspected using SEM. Moreover, the rheological and damping properties of the examined materials with and without a magnetic field were experimentally investigated. In addition, the free vibration responses of the adaptive three-layered MR beams were studied at different fixed magnetic field levels. The free vibration tests revealed that an applied non-homogeneous magnetic field causes a shift in natural frequency values and a reduction in the vibration amplitudes of the CFRP/MRE adaptive beams. The reduction in vibration amplitude was attributed mainly to the stiffening effect of the MRE core and only a minor contribution was made by the enhanced damping capacity, which was evidenced by the variation in damping ratio values.

  4. Preparation, Spectroscopy, Physicochemical Properties and X-ray Structure Analysis of 3,4,5-Trimethoxy N(2-hydroxybenzylidene) aniline

    Kodjo Charles Guillaume; Zabri Herve; Benie Anoubile; Estienne Jacques

    2009-01-01

    3,4,5-Trimethoxy N-(salicylidene) aniline was synthesized and characterized by IR spectroscopy, 1H NMR and x-ray single crystal analysis. UV-visible spectroscopy was used for physicochemical tests. X-ray data reveals that the crystalline network cohesion of this compound is essentially assured by CH/pi type hydrogen bounds. It crystallized in the orthorhombic Pbcn space group. Electronic spectroscopy shows that the title compound doesn't present photochromic property but thermochromic one. In...

  5. Design, realization and structural testing of a compliant adaptable wing

    Molinari, G.; Quack, M.; Arrieta, A. F.; Morari, M.; Ermanni, P.

    2015-10-01

    This paper presents the design, optimization, realization and testing of a novel wing morphing concept, based on distributed compliance structures, and actuated by piezoelectric elements. The adaptive wing features ribs with a selectively compliant inner structure, numerically optimized to achieve aerodynamically efficient shape changes while simultaneously withstanding aeroelastic loads. The static and dynamic aeroelastic behavior of the wing, and the effect of activating the actuators, is assessed by means of coupled 3D aerodynamic and structural simulations. To demonstrate the capabilities of the proposed morphing concept and optimization procedure, the wings of a model airplane are designed and manufactured according to the presented approach. The goal is to replace conventional ailerons, thus to achieve controllability in roll purely by morphing. The mechanical properties of the manufactured components are characterized experimentally, and used to create a refined and correlated finite element model. The overall stiffness, strength, and actuation capabilities are experimentally tested and successfully compared with the numerical prediction. To counteract the nonlinear hysteretic behavior of the piezoelectric actuators, a closed-loop controller is implemented, and its capability of accurately achieving the desired shape adaptation is evaluated experimentally. Using the correlated finite element model, the aeroelastic behavior of the manufactured wing is simulated, showing that the morphing concept can provide sufficient roll authority to allow controllability of the flight. The additional degrees of freedom offered by morphing can be also used to vary the plane lift coefficient, similarly to conventional flaps. The efficiency improvements offered by this technique are evaluated numerically, and compared to the performance of a rigid wing.

  6. Realization of Complete Synchronization between Different Systems by Using Structure Adaptation

    LIU Zeng-Rong; LUO Ji-Gui

    2006-01-01

    @@ We study the complete synchronization between different systems. Based on our new idea about structure adaptation, a new synchronized method, i.e. the structure adaptive method, is proposed. We believe that this self-adaptive mechanism correctly represents essential characteristics of self-adaptation in complex systems. We also show that this method is reasonable both from the coupling viewpoint in physics and from the controller design viewpoint in control theory.

  7. Delineating the physico-chemical, structural, and water characteristic changes during the deterioration of fresh noodles: Understanding the deterioration mechanisms of fresh noodles.

    Li, Man; Ma, Meng; Zhu, Ke-Xue; Guo, Xiao-Na; Zhou, Hui-Ming

    2017-02-01

    In this study, changes in fresh noodles during storage were evaluated at the physico-chemical, structural, and molecular levels. An increase in TPC and decrease in L(∗) value mostly occurred during the first 24h; the pH value significantly decreased (Pwater sorption isotherm of fresh noodles decreased during storage, and the NMR transverse relaxation peak shifted right with an increased peak area between 10 and 100ms. MRI images showed that with increased storage time, the original structure was damaged and water distribution became non-uniform and migrated to the surface. TPC, pH, and L(∗) value were selected as the visualized parameters to characterize the fresh noodle deterioration, based on the correlation and factor analyses. PMID:27596433

  8. Physicochemical status of plasma membranes of adipose tissue and liver of rats at remote times following 1 Gy gamma, irradiation structural changes in membranes

    The structural status of plasma membranes of adipose tissue and liver of rats was investigated at remote times (from 15 to 380 days) after single 1 Gy gamma-irradiation. The structural status was estimated by pyrene excimerisation parameters and also by both induction resonance energy transfer method and membrane tryptophan fluorescence spectral characteristics. On days 50-100 following irradiation the microviscosity of a lipid phase of membranes increased and the mode of lipid/protein interactions changed, whereas at later times the indices under study did not vary from the controls. Comparison of the data obtained with the former results on lipid content changes indicates that the physicochemical status of plasma membranes in rat adipose tissue and liver is modified at remote times following 1 Gy gamma-irradiation

  9. Improving predictions of protein-protein interfaces by combining amino acid-specific classifiers based on structural and physicochemical descriptors with their weighted neighbor averages.

    Fábio R de Moraes

    Full Text Available Protein-protein interactions are involved in nearly all regulatory processes in the cell and are considered one of the most important issues in molecular biology and pharmaceutical sciences but are still not fully understood. Structural and computational biology contributed greatly to the elucidation of the mechanism of protein interactions. In this paper, we present a collection of the physicochemical and structural characteristics that distinguish interface-forming residues (IFR from free surface residues (FSR. We formulated a linear discriminative analysis (LDA classifier to assess whether chosen descriptors from the BlueStar STING database (http://www.cbi.cnptia.embrapa.br/SMS/ are suitable for such a task. Receiver operating characteristic (ROC analysis indicates that the particular physicochemical and structural descriptors used for building the linear classifier perform much better than a random classifier and in fact, successfully outperform some of the previously published procedures, whose performance indicators were recently compared by other research groups. The results presented here show that the selected set of descriptors can be utilized to predict IFRs, even when homologue proteins are missing (particularly important for orphan proteins where no homologue is available for comparative analysis/indication or, when certain conformational changes accompany interface formation. The development of amino acid type specific classifiers is shown to increase IFR classification performance. Also, we found that the addition of an amino acid conservation attribute did not improve the classification prediction. This result indicates that the increase in predictive power associated with amino acid conservation is exhausted by adequate use of an extensive list of independent physicochemical and structural parameters that, by themselves, fully describe the nano-environment at protein-protein interfaces. The IFR classifier developed in this study

  10. Improving predictions of protein-protein interfaces by combining amino acid-specific classifiers based on structural and physicochemical descriptors with their weighted neighbor averages.

    de Moraes, Fábio R; Neshich, Izabella A P; Mazoni, Ivan; Yano, Inácio H; Pereira, José G C; Salim, José A; Jardine, José G; Neshich, Goran

    2014-01-01

    Protein-protein interactions are involved in nearly all regulatory processes in the cell and are considered one of the most important issues in molecular biology and pharmaceutical sciences but are still not fully understood. Structural and computational biology contributed greatly to the elucidation of the mechanism of protein interactions. In this paper, we present a collection of the physicochemical and structural characteristics that distinguish interface-forming residues (IFR) from free surface residues (FSR). We formulated a linear discriminative analysis (LDA) classifier to assess whether chosen descriptors from the BlueStar STING database (http://www.cbi.cnptia.embrapa.br/SMS/) are suitable for such a task. Receiver operating characteristic (ROC) analysis indicates that the particular physicochemical and structural descriptors used for building the linear classifier perform much better than a random classifier and in fact, successfully outperform some of the previously published procedures, whose performance indicators were recently compared by other research groups. The results presented here show that the selected set of descriptors can be utilized to predict IFRs, even when homologue proteins are missing (particularly important for orphan proteins where no homologue is available for comparative analysis/indication) or, when certain conformational changes accompany interface formation. The development of amino acid type specific classifiers is shown to increase IFR classification performance. Also, we found that the addition of an amino acid conservation attribute did not improve the classification prediction. This result indicates that the increase in predictive power associated with amino acid conservation is exhausted by adequate use of an extensive list of independent physicochemical and structural parameters that, by themselves, fully describe the nano-environment at protein-protein interfaces. The IFR classifier developed in this study is now

  11. The Coevolution of Phycobilisomes: Molecular Structure Adapting to Functional Evolution

    Fei Shi

    2011-01-01

    Full Text Available Phycobilisome is the major light-harvesting complex in cyanobacteria and red alga. It consists of phycobiliproteins and their associated linker peptides which play key role in absorption and unidirectional transfer of light energy and the stability of the whole complex system, respectively. Former researches on the evolution among PBPs and linker peptides had mainly focused on the phylogenetic analysis and selective evolution. Coevolution is the change that the conformation of one residue is interrupted by mutation and a compensatory change selected for in its interacting partner. Here, coevolutionary analysis of allophycocyanin, phycocyanin, and phycoerythrin and covariation analysis of linker peptides were performed. Coevolution analyses reveal that these sites are significantly correlated, showing strong evidence of the functional and structural importance of interactions among these residues. According to interprotein coevolution analysis, less interaction was found between PBPs and linker peptides. Our results also revealed the correlations between the coevolution and adaptive selection in PBS were not directly related, but probably demonstrated by the sites coupled under physical-chemical interactions.

  12. Parallel Block Structured Adaptive Mesh Refinement on Graphics Processing Units

    Beckingsale, D. A. [Atomic Weapons Establishment (AWE), Aldermaston (United Kingdom); Gaudin, W. P. [Atomic Weapons Establishment (AWE), Aldermaston (United Kingdom); Hornung, R. D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Gunney, B. T. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Gamblin, T. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Herdman, J. A. [Atomic Weapons Establishment (AWE), Aldermaston (United Kingdom); Jarvis, S. A. [Atomic Weapons Establishment (AWE), Aldermaston (United Kingdom)

    2014-11-17

    Block-structured adaptive mesh refinement is a technique that can be used when solving partial differential equations to reduce the number of zones necessary to achieve the required accuracy in areas of interest. These areas (shock fronts, material interfaces, etc.) are recursively covered with finer mesh patches that are grouped into a hierarchy of refinement levels. Despite the potential for large savings in computational requirements and memory usage without a corresponding reduction in accuracy, AMR adds overhead in managing the mesh hierarchy, adding complex communication and data movement requirements to a simulation. In this paper, we describe the design and implementation of a native GPU-based AMR library, including: the classes used to manage data on a mesh patch, the routines used for transferring data between GPUs on different nodes, and the data-parallel operators developed to coarsen and refine mesh data. We validate the performance and accuracy of our implementation using three test problems and two architectures: an eight-node cluster, and over four thousand nodes of Oak Ridge National Laboratory’s Titan supercomputer. Our GPU-based AMR hydrodynamics code performs up to 4.87× faster than the CPU-based implementation, and has been scaled to over four thousand GPUs using a combination of MPI and CUDA.

  13. Adapt

    Bargatze, L. F.

    2015-12-01

    Active Data Archive Product Tracking (ADAPT) is a collection of software routines that permits one to generate XML metadata files to describe and register data products in support of the NASA Heliophysics Virtual Observatory VxO effort. ADAPT is also a philosophy. The ADAPT concept is to use any and all available metadata associated with scientific data to produce XML metadata descriptions in a consistent, uniform, and organized fashion to provide blanket access to the full complement of data stored on a targeted data server. In this poster, we present an application of ADAPT to describe all of the data products that are stored by using the Common Data File (CDF) format served out by the CDAWEB and SPDF data servers hosted at the NASA Goddard Space Flight Center. These data servers are the primary repositories for NASA Heliophysics data. For this purpose, the ADAPT routines have been used to generate data resource descriptions by using an XML schema named Space Physics Archive, Search, and Extract (SPASE). SPASE is the designated standard for documenting Heliophysics data products, as adopted by the Heliophysics Data and Model Consortium. The set of SPASE XML resource descriptions produced by ADAPT includes high-level descriptions of numerical data products, display data products, or catalogs and also includes low-level "Granule" descriptions. A SPASE Granule is effectively a universal access metadata resource; a Granule associates an individual data file (e.g. a CDF file) with a "parent" high-level data resource description, assigns a resource identifier to the file, and lists the corresponding assess URL(s). The CDAWEB and SPDF file systems were queried to provide the input required by the ADAPT software to create an initial set of SPASE metadata resource descriptions. Then, the CDAWEB and SPDF data repositories were queried subsequently on a nightly basis and the CDF file lists were checked for any changes such as the occurrence of new, modified, or deleted

  14. Analysis of morphological structuring elements generated using adaptive resonance theory

    Sharpe, John P.; Sungar, Nilgun; Narayanswamy, Ramkumar; Johnson, Kristina M.

    1995-03-01

    In this paper we consider the formation of morphological templates using adaptive resonance theory. We examine the role of object variability and noise on the clustering of different sized objects as a function of the vigilance parameter. We demonstrate that the fuzzy adaptive resonance theory is robust in the presence of noise but that for poor choice of vigilance there is a proliferation of prototypical categories. We apply the technique to detection of abnormal cells in pap smears.

  15. Physicochemical and micro-structural properties of flours, starch and proteins from two varieties of legumes: bambara groundnut (Vigna subterranea).

    Kaptso, Kuaté Giscard; Njintang, Yanou Nicolas; Nguemtchouin, Mbouga Marie Goletti; Scher, Joël; Hounhouigan, Joseph; Mbofung, Carl Moses

    2015-08-01

    This work is part of a large study aimed to evaluate the potential of bambara groundnut (Vigna subterranea) flour as starting raw material for the preparation of a widely cherished legume-based food product known as koki. Towards this objective, the flours from two varieties of bambara groundnut along with their respective starch and protein isolates were analyzed for some physicochemical and microstructural properties. It was observed that bambara flour contained appreciable amount of proteins (24.0-25.5 g/100 g), carbohydrates (57.9-61.7 g/100 g), fiber (3.45-3.68 g/100 g) and ash (3.65-3.85 g/100 g) with marginal differences between both varieties. The properties of starch and proteins isolated from the flours were different from one variety to another. In particular the starch granules of the white variety were larger (size range 10-35 μm) and polygonal while those from the black variety were smaller (size range 6-15 μm) and spherical in shape. In addition, the peak of gelatinization temperature was higher for white variety (81.7 °C) than for black variety (77.5 °C). The gelatinization temperature and the enthalpy of gelatinization of starch in the flours were systematically lower than for the starch isolates, suggesting an interaction of starch with other components on the gelatinization process. PMID:26243911

  16. Adaptive synchronization of a class of chaotic systems via variable structure control

    Li Huiguang; Zhang Xinying; Guan Xinping

    2005-01-01

    The synchronization problem under two cases is considered. One is that the bound on the uncertainty existing in the controller is known, the other is that the bound is unknown. In the latter case, the simple adaptation laws for upper bound on the norm of the uncertainty is proposed. Using this adaptive upper bound, a variable structure control is designed. The proposed method does not guarantee the convergence of the adaptive upper bound to the real one but makes the system asymptotically stable.

  17. DCB-adapted plant cells possess unique wall structure

    Shedletzky, E.; Shmuel, M. (Hebrew Univ., Jerusalem (Israel)); Delmer, D. (Hebrew Univ., Jerusalem (Israel) Michigan State Univ., East Lansing (USA)); Lamport, D. (Michigan State Univ., East Lansing (USA))

    1990-05-01

    Suspension-cultured cells of tomato (Lycopersicon esculentum VF 36) haven been adapted to growth on high concentrations of 2,6-dichloro-benzonitrile (DCB), an herbicide which inhibits cellulose biosynthesis. The mechanism of adaptation appears to rest largely on the ability of thee cells to divide and expand in the virtual absence of a cellulose-xyloglucan network. Walls of adapted cells growing on DCB also differ from non-adapted cells by having reduced levels of hydroxyproline in protein, both in bound and salt-elutable form, and in having a much higher proportion of homogalacturonon and rhamnogalacturonan-like polymers. Most of these latter polymers are apparently cross-linked in the wall via phenolic-esters and/or phenolic ether linkages, and these polymers appear to represent the major load-bearing network in thee unusual cell walls. The surprising finding that plant cells can survive in the virtual absence of a major load-bearing network in their primary cell walls indicates that plants possess remarkable flexibility for tolerating changes in wall composition.

  18. Self-Reconfigurable Modular Robots Adaptively Transforming a Mechanical Structure: Algorithm for Adaptive Transformation to Load Condition

    Yosuke Suzuki

    2011-01-01

    Full Text Available Self-reconfigurable modular robots are composed of modules which are able to autonomously change the way they are connected. An appropriate control algorithm enables the modular robots to change their shape in order to adapt to their immediate environment. In this paper, we propose an algorithm for adaptive transformation to load condition of the modular robots. The algorithm is based on a simple idea that modules have tendency to gather around stress-concentrated parts and reinforce the parts. As a result of the self-reconfiguration rule, the modular robots form an appropriate structure to stand for the load condition. Applying the algorithm to our modular robot named “CHOBIE II,” we show by computer simulation that the modules are able to construct a cantilever structure with avoiding overstressed states.

  19. Leaf structural adaptations of two Limonium miller (Plumbaginales, Plumbaginaceae taxa

    Zorić Lana N.

    2013-01-01

    Full Text Available Limonium gmelinii (Willd. O. Kuntze 1891 subsp. hungaricum (Klokov Soó is Pannonian endemic subspecies that inhabits continental halobiomes, while Limonium anfractum (Salmon Salmon 1924 is one of the indicators of halophyte vegetation of marine rocks and its distribution is restricted to the southern parts of Mediterranean Sea coast. In this work, micromorphological and anatomical characters of leaves of these two Limonium taxa were analyzed, in order to examine their adaptations to specific environmental conditions on saline habitats. The results showed that both taxa exhibited strong xeromorphic adaptations that reflected in flat cell walls of epidermal cells, thick cuticle, high palisade/spongy tissue ratio, high index of palisade cells, the presence of sclereid idioblasts in leaf mesophyll and mechanical tissue by phloem and xylem. Both taxa are crynohalophytes and have salt glands on adaxial and abaxial epidermis for excretion of surplus salt. Relatively high dimensions of mesophyll cells, absence of non-glandular hairs and unprotected stomata slightly increased above the level of epidermal cells, are also adaptations to increased salinity. [Projekat Ministarstva nauke Republike Srbije, br. 173002

  20. Synthesis, structural and physico-chemical studies of the monocrystal superconductor oxides Hg Ba2 Can-1 Cun O2n+2+δ

    The thesis presents the synthesis and the structural and physico-chemical properties of the mercury-based monocrystal superconductor oxides. The results reported in the first chapter refer to the first three members of the mercury cuprate series Hg-1201, Hg-1212 and Hg-1223. In the second chapter detailed results concerning the structure of these compounds are given highlighting the features common to all cuprates and pointing out the peculiarities of mercury phases. The third chapter presents the phase diagrams (δ, T, p(O2)) of the compounds HgBa2CuO4+δ and HgBa2Ca2Cu3O8+δ obtained by thermogravimetry under controlled atmosphere between 150 deg.C and 500 deg.C and thermodynamic equilibrium conditions. In the case of Hg-1201, the critical temperature shows a variation close to a parabolic law, with an optimal Tc of 96 K (δ≅0.10) while in Hg-1223 the Tc increases linearly with the O content up to the optimal Tc of 135 K (δ≅0.19) and decreases only by 2 K in the over-doped regime. Finally, in the fourth chapter different physical properties are reviewed. The obtained monocrystals allowed studying the resistive transitory anisotropy, the torque, the specific heat, the nuclear magnetic resonance and the Raman diffusion

  1. New physicochemical concepts on exoemission

    Results of investigations of exoemission ionic component from organic and inorganic solids in physico-chemical transformations are presented. Thermostimulated exoemission of negative and positive ions from ammonium surface after corrosion tests in 0.1 M NaCl solution during 20 hours is studied. Positive and negative charge exoemission on cooling to 77 K and on the following heating to 293 K of rigid foam polyuretane sample is also studied. Independent on the emitter nature and excitation means one and the same processes take place - break of chemical bonds and separation of charges in the dielectric with the following recombination of active particles. Thermostimulated emission peaks are in the regions of phase (relaxation) transitions due to the most probable physico-chemical interactions in the broken emitter structure. Energy of relaxation transitions and chemical interactions is consumed on the charge emission

  2. An Adaptive Mesh Algorithm: Mesh Structure and Generation

    Scannapieco, Anthony J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-06-21

    The purpose of Adaptive Mesh Refinement is to minimize spatial errors over the computational space not to minimize the number of computational elements. The additional result of the technique is that it may reduce the number of computational elements needed to retain a given level of spatial accuracy. Adaptive mesh refinement is a computational technique used to dynamically select, over a region of space, a set of computational elements designed to minimize spatial error in the computational model of a physical process. The fundamental idea is to increase the mesh resolution in regions where the physical variables are represented by a broad spectrum of modes in k-space, hence increasing the effective global spectral coverage of those physical variables. In addition, the selection of the spatially distributed elements is done dynamically by cyclically adjusting the mesh to follow the spectral evolution of the system. Over the years three types of AMR schemes have evolved; block, patch and locally refined AMR. In block and patch AMR logical blocks of various grid sizes are overlaid to span the physical space of interest, whereas in locally refined AMR no logical blocks are employed but locally nested mesh levels are used to span the physical space. The distinction between block and patch AMR is that in block AMR the original blocks refine and coarsen entirely in time, whereas in patch AMR the patches change location and zone size with time.

  3. Substitution effect of pentavalent bismuth ions on the electronic structure and physicochemical properties of perovskite-structured Ba(In0.5Ta0.5-xBix)O3 semiconductors

    We have investigated the substitution effect of pentavalent bismuth ions on the electronic structure and physicochemical properties of barium indium tantalate. X-ray diffraction, X-ray absorption spectroscopic, and energy dispersive spectroscopic microprobe analyses reveal that, under oxygen atmosphere of 1 atm, pentavalent Bi ions are successfully stabilized in the octahedral site of the perovskite tantalate lattice. According to diffuse reflectance UV-vis spectroscopic analysis, the Bi substitution gives rise to the significant narrowing of band gap of barium indium tantalate even at a low Bi content of ∼5%, underscoring a high efficiency of Bi substitution in the band gap engineering. Such an effective narrowing of the band gap upon the Bi substitution would be attributable to the lowering of conduction band position due to the high electronegativity of BiV substituent. As a result of band gap engineering, the Ba(In0.5Ta0.5-xBix)O3 compounds with x ≥ 0.03 can generate photocurrents under visible light irradiation (λ > 420 nm). Based on the present experimental findings, it becomes clear that the substitution of highly electronegative p-block element like BiV ion can provide a very powerful tool for tailoring the electronic structure and physicochemical properties of wide band gap semiconductors

  4. ADAPTIVE FINITE ELEMENT METHOD FOR HIGH-SPEED FLOW-STRUCTURE INTERACTION

    Wiroj LIMTRAKARN; Pramote DECHAUMPHAI

    2004-01-01

    An adaptive finite element method for high-speed flow-structure interaction is presented. The cell-centered finite element method is combined with an adaptive meshing technique to solve the Navier-Stokes equations for high-speed compressible flow behavior. The energy equation and the quasi-static structural equations for aerodynamically heated structures are solved by applying the Galerkin finite element method. The finite element formulation and computational procedure are described. Interactions between the high-speed flow, structural heat transfer, and deformation are studied by two applications of Mach 10 flow over an inclined plate, and Mach 4 flow in a channel.

  5. Synthesis, structure and physicochemical characterization of a noncentrosymmetric, quaternary thiostannate: EuCu2SnS4

    EuCu2SnS4 was prepared by a stoichiometric combination of the elements heated to 700 deg. C for 125 h. The structure was determined by single crystal X-ray diffraction methods. The compound crystallizes in the noncentrosymmetric, orthorhombic space group Ama2 with a=10.4793(1) A, b=10.3610(2) A, c=6.4015(1) A, Z=4, R1=0.99% and wR2=2.37%. The structure type is that of SrCu2GeSe4. The structure can be described as a three-dimensional network built from near perfect SnS4 and distorted CuS4 tetrahedra together with EuS8 square antiprisms. The dark red compound is a semiconductor with an optical bandgap of 1.85 eV. - Graphical Abstract: EuCu2SnS4 crystallizes in the orthorhombic space group Ama2 and adopts the SrCu2GeSe4 structure-type. The structure can be described as a three-dimensional network built from near perfect SnS4 and distorted CuS4 tetrahedra together with EuS8 square antiprisms

  6. Structured estimation - Sample size reduction for adaptive pattern classification

    Morgera, S.; Cooper, D. B.

    1977-01-01

    The Gaussian two-category classification problem with known category mean value vectors and identical but unknown category covariance matrices is considered. The weight vector depends on the unknown common covariance matrix, so the procedure is to estimate the covariance matrix in order to obtain an estimate of the optimum weight vector. The measure of performance for the adapted classifier is the output signal-to-interference noise ratio (SIR). A simple approximation for the expected SIR is gained by using the general sample covariance matrix estimator; this performance is both signal and true covariance matrix independent. An approximation is also found for the expected SIR obtained by using a Toeplitz form covariance matrix estimator; this performance is found to be dependent on both the signal and the true covariance matrix.

  7. Composites prepared from the waterborne polyurethane cationomers-modified graphene. Part I. Synthesis, structure, and physicochemical properties

    Król, P.; Król, B.; Pielichowska, K.; Špírková, Milena

    2015-01-01

    Roč. 293, č. 2 (2015), s. 421-431. ISSN 0303-402X R&D Projects: GA ČR(CZ) GA13-06700S Institutional support: RVO:61389013 Keywords : polyurethane film s * surface structure * AFM microscopy Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.865, year: 2014

  8. Effect of various structure directing agents on the physicochemical properties of the silica aerogels prepared at an ambient pressure

    Sarawade, Pradip

    2013-12-01

    We studied the effects of various surfactants on the textural properties (BET surface area, pore size, and pore volume) of the silica aerogels prepared at an ambient pressure. A simple surface modification of silica gel prepared at an ambient pressure through hydrolysis and polycondensation of TEOS as asilica precursor was conducted using various structure directing agents. The treatment was found to induce a significant difference in the porosity of the silica aerogel. Highly porous silica aerogels with bimodal porous structures were prepared by modifying the surface of the silica wet-gel (alcogel) with trimethylchlorosilane (TMCS) in order to preserve its porosity. The samples were analyzed by small-angle X-ray scattering and nitrogen adsorption. In this work, a possible new type of highly porous hydrophobic silica aerogel with a bimodal porous structure is presented. A hydrophilic extremely porous (high surface area and large pore volume) silica aerogel was obtained by heating the as-synthesized hydrophobic silica aerogel at 400°C for 1 h. There was a significant effect of structure directing agent on the textural properties, such as specific surface area, pore size distribution and cumulative pore volume of the silicaaerogels. © 2013 Elsevier B.V. All rights reserved.

  9. Inverse Finite Element Method Investigation for Adaptive Structures Project

    National Aeronautics and Space Administration — This research project is evaluating an innovative technique that uses fiber optic strain sensors to measure structural deformations and full field strains. An...

  10. Trust, Contracting, and Adaptation in Agri-Food Hybrid Structures

    Gaetano Martino

    2011-01-01

    The paper considers the relationship between trust and governance structure from a Transaction Cost Economics perspective. The role of trust in the coordinating decisions is variously conceptualized according to the theoretical view adopted by the scholars. The present study adopt the three-level schema introduced by Williamson (1996) and suggest that determinants of trust may operate both at institutional and governance structure level. The analytical framework depicted maintains that trust ...

  11. Synthesis, structure, and physicochemical investigations of the new α Cu0.50TiO(PO4) oxyphosphate

    The room-temperature crystal structure of a new Cu(II) oxyphosphate-α Cu0.50IITiO(PO4)-was determined from X-ray single crystals diffraction data, in the monoclinic system, space group P21/c. The refinement from 5561 independent reflections lead to the following parameters: a=7.5612(4)A, b=7.0919(4)A, c=7.4874(4)A, β=122.25(1)o, Z=4, with the final R=0.0198, wR=0.0510. The structure of α Cu0.50IITiO(PO4) can be described as a TiOPO4 framework constituted by chains of tilted corner-sharing [TiO6] octahedra running parallel to the c-axis and cross linked by phosphate [PO4] tetrahedra, where one-half of octahedral cavities created are occupied by Cu atoms. Ti atoms are displaced from the center of octahedra units in alternating long (2.308 A) and short (1.722 A) Ti-O(1) bonds along chains. Such O(1) atoms not linked to P atoms justify the oxyphosphate formulation α Cu0.50TiO(PO4). The divalent cations Cu2+ occupy a Jahn-Teller distorted octahedron sharing two faces with two [TiO6] octahedra. EPR and optical measurements are in good agreement with structural data. The X-ray diffraction results are supported by Raman and infrared spectroscopy studies that confirmed the existence of the infinite chains -Ti-O-Ti-O-Ti-. α Cu0.50TiO(PO4) shows a Curie-Weiss paramagnetic behavior in the temperature range 4-80 K. - Graphical abstract: Projection of the structure of α Cu0.50TiO(PO4) along the a-axis

  12. A framework for adaptive e-learning for continuum mechanics and structural analysis

    Mosquera Feijoo, Juan Carlos; Plaza Beltrán, Luis Francisco; González Rodrigo, Beatriz

    2015-01-01

    This paper presents a project for providing the students of Structural Engineering with the flexibility to learn outside classroom schedules. The goal is a framework for adaptive E-learning based on a repository of open educational courseware with a set of basic Structural Engineering concepts and fundamentals. These are paramount for students to expand their technical knowledge and skills in structural analysis and design of tall buildings, arch-type structures as well as bridges. Thus, conc...

  13. Genetic algorithms for optimal design and control of adaptive structures

    Ribeiro, R; Dias-Rodrigues, J; Vaz, M

    2000-01-01

    Future High Energy Physics experiments require the use of light and stable structures to support their most precise radiation detection elements. These large structures must be light, highly stable, stiff and radiation tolerant in an environment where external vibrations, high radiation levels, material aging, temperature and humidity gradients are not negligible. Unforeseen factors and the unknown result of the coupling of environmental conditions, together with external vibrations, may affect the position stability of the detectors and their support structures compromising their physics performance. Careful optimization of static and dynamic behavior must be an essential part of the engineering design. Genetic Algorithms ( GA) belong to the group of probabilistic algorithms, combining elements of direct and stochastic search. They are more robust than existing directed search methods with the advantage of maintaining a population of potential solutions. There is a class of optimization problems for which Ge...

  14. Successive cambia: a developmental oddity or an adaptive structure?

    Elisabeth M R Robert

    Full Text Available BACKGROUND: Secondary growth by successive cambia is a rare phenomenon in woody plant species. Only few plant species, within different phylogenetic clades, have secondary growth by more than one vascular cambium. Often, these successive cambia are organised concentrically. In the mangrove genus Avicennia however, the successive cambia seem to have a more complex organisation. This study aimed (i at understanding the development of successive cambia by giving a three-dimensional description of the hydraulic architecture of Avicennia and (ii at unveiling the possible adaptive nature of growth by successive cambia through a study of the ecological distribution of plant species with concentric internal phloem. RESULTS: Avicennia had a complex network of non-cylindrical wood patches, the complexity of which increased with more stressful ecological conditions. As internal phloem has been suggested to play a role in water storage and embolism repair, the spatial organisation of Avicennia wood could provide advantages in the ecologically stressful conditions species of this mangrove genus are growing in. Furthermore, we could observe that 84.9% of the woody shrub and tree species with concentric internal phloem occurred in either dry or saline environments strengthening the hypothesis that successive cambia provide the necessary advantages for survival in harsh environmental conditions. CONCLUSIONS: Successive cambia are an ecologically important characteristic, which seems strongly related with water-limited environments.

  15. Adaptive variable structure control based on backstepping for spacecraft with reaction wheels during attitude maneuver

    SONG Bin; MA Guang-fu; LI Chuan-jiang

    2009-01-01

    An adaptive variable structure control method based on backstepping is proposed for the attitude maneuver problem of rigid spacecraft with reaction wheel dynamics in the presence of uncertain inertia matrix and external disturbances. The proposed control approach is a combination of the backstepping and the adaptive variable structure control. The cascaded structure of the attitude maneuver control system with reaction wheel dynamics gives the advantage for applying the backstepping method to construct Lyapunov functions. The robust stability to external disturbances and parametric uncertainty is guaranteed by the adaptive variable structure control. To validate the proposed control algorithm, numerical simulations using the proposed approach are performed for the attitude maneuver mission of rigid spacecraft with a configuration consisting of four reaction wheels for actuator and three magnetorquers for momentum unloading. Simulation results verify the effectiveness of the proposed control algorithm.

  16. Improving the performance of link prediction by adaptively exploiting multiple structural features of networks

    Ma, Chuang; Zhang, Hai-Feng

    2016-01-01

    So far, many network-structure-based link prediction methods have been proposed. However, these traditional methods were proposed by highlighting one or two structural features of networks, and then use the methods to implement link prediction in different networks. In many cases, the performance is not ideal since each network has its unique underlying structural features. In this article, by analyzing different real networks, we find that the structural features of different networks are remarkably different. In particular, even in the same networks, their inner structural features are utterly different. Inspired by these facts, an \\emph{adaptive} link prediction method is proposed to incorporate multiple structural features from the perspective of combination optimization. In the model, the weight of each structural feature is \\emph{adaptively } determined by logistic regression but not be artificially given in advance. According to our experimental results, we find that the logistic regression based link ...

  17. Object oriented structures for adaptive multilevel methods for flow simulation; Objektorientierte Strukturen fuer adaptive Multilevelverfahren zur Stroemungssimulation

    Mueller, A.

    2000-09-01

    The dissertation investigates object-oriented structures on whose basis adaptive multilevel methods can be implemented. First, concepts for grid management, building of numeric structures and for representation and solution of the resulting systems of equations are discussed. These abstract concepts are then concretized on the basis of two examples. The first example is a standard FE discretization of a two-dimensional linear elliptic second order boundary value problem. The grid is refined adaptively using an a-posteriory error assessment element. The linear equation systems are solved by a multilevel preconditioned CG method. The second example is the solution of the three-dimensional, stationary incompressible Eulerian equations in a rotary coordinate system. Discretization takes place with the aid of a finite element developed by Rannacher and Turek on the basis of hexalaterial grids. The equation systems are solved using a nonlinear multigrid system. Local refining and a multilevel solution have been prepared. Test calculations show that the theory is practically applicable, e.g. to flow through hydraulic turbine rotors. [German] Die Dissertation befasst sich mit objektorientierten Strukturen, auf deren Basis sich adaptive Multilevelverfahren implementieren lassen. Zunaechst werden Konzepte zur Gitterverwaltung, zum Aufbau numerischer Strukturen und zur Darstellung sowie Loesung der resultierenden Gleichungssysteme erlaeutert. Anschliessend werden diese abstrakten Konzepte anhand zweier Beispiele konkretisiert. Das erste Beispiel betrifft die Standard Finite Elemente Diskretisierung eines zweidimensionalen linearen elliptischen Randwertproblems 2. Ordnung. Die Netzverfeinerung geschieht adaptiv mit Hilfe eines a-posteriori Fehlerschaetzers. Zur Loesung der linearen Gleichungssysteme wird ein multilevel vorkonditioniertes CG-Verfahren verwendet. Als zweites Beispiel dient die Loesung der dreidimensionalen, stationaeren, inkompressiblen Euler Gleichungen im

  18. CONSTRUCTIVE MODEL OF DATA STRUCTURES ADAPTATION IN RAM: PART I. PROGRAM TEXT CONSTRUCTING

    V. I. Shynkarenko

    2016-02-01

    Full Text Available Purpose. Rapidly growing volumes of information systems data being manipulated significantly reduce the temporary algorithms effeciency of their processing . Effective data layout in RAM is one of the directions of solving this problem. It is necessary to develop the model to solve problems of efficient automated data layout in RAM. Methodology. For processes simulation of data structures (DS adaptation in RAM, the methodology of mathematical and algorithmic constructivism was applied. This approach involves the development of constructive and productive structures (CPS with transformations of specialization, interpretation, specification and implementation. CPS development provides definition of expandable vector, signature of relations, transactions and constructive axioms. The most complex and essential part of the set of axioms is generated substitution rules that determine the output process of respective structures. Findings. CPS system was developed by the authors, consisting of the logical structure constructor of data, converters of logical structure in to a software interface and implementation in a programming language, constructors of scenarios and adaptation processes. The result of the adaptation process constructor is software text generations of the class library that implements the specified logical data structure with appropriate processing operations and its compilation in binary code. Originality. Structural model of development processes and data structures adaptation to different software and hardware environments was first proposed. It adapts date layout in the RAM and data processing algorithms. Application of constructivism in simulation allowed within a single approach and applied tools linking the data models and algorithms of their processing with performance criteria. Formation methodology of CPS system, mechanisms, and links between complementary CPS were improved. Modification of the constructor and converters

  19. Human population structure and the adaptive response to pathogen-induced selection pressures

    Novembre, John; Han, Eunjung

    2012-01-01

    The past few years of research in human evolutionary genetics have provided novel insights and questions regarding how human adaptations to recent selective pressures have taken place. Here, we review the advances most relevant to understanding human evolution in response to pathogen-induced selective pressures. Key insights come from theoretical models of adaptive evolution, particularly those that consider spatially structured populations, and from empirical population genomic studies of ad...

  20. NMR solution structure of a cold-adapted thiol-disulfide oxidoreductase

    Collins, Tony; Matzapetakis, Manolis; Pais, Tiago; Lamosa, Pedro; Santos, Helena

    2011-01-01

    Psychrophilic enzymes produced by cold-adapted micro-organisms have successfully overcome the low temperature challenge and adapted to maintain high catalytic rates in their permanently cold environments. The current consensus is that this high activity at low temperatures is mainly achieved through an increase in the flexibility of the protein structure, thereby allowing for the molecular motions necessary for activity in their low thermal energy environment. The actual molecular basis for t...

  1. Physico-chemical, functional and structural properties of RS3/RS4 from kidney bean (Phaseolus vulgaris) cultivars.

    Gani, Adil; Jan, Amreen; Shah, Asima; Masoodi, F A; Ahmad, Mudasir; Ashwar, Bilal Ahmad; Akhter, Rehana; Wani, Idrees Ahmed

    2016-06-01

    Starch isolated from four kidney bean cultivars (Yellow bean, Red bean, Black bean and White bean) were physically and chemically modified in order to prepare resistant starch (RS3/RS4). Following the Heat-moisture treatment (HMT) and Citric acid modification (CT) of the native starch, the amylose content got decreased whereas bulk and tapped density (g/ml) increased. Both HMT and CT reduced the swelling power and the solubility of native starch. Pasting temperature increased and peak, breakdown, final, and set-back viscosity decreased after both the modifications. Fourier Transform Infrared Spectroscopy (FTIR) analysis displayed peaks at 1020cm(-1) in HMT and 1724cm(-1) in CT starches. Differential Scanning Calorimetry (DSC) analysis revealed that samples were more stable after modification. X-ray diffraction (XRD) analysis revealed reordering of chain segments to more crystalline structure. These results suggested modifications resulted in starch with improved properties and could be a possible method for the RS preparation with better thermal stability. PMID:26976068

  2. Exploring functional relationships between post-fire soil water repellency, soil structure and physico-chemical properties

    Quarfeld, Jamie; Brook, Anna; Keestra, Saskia; Wittenberg, Lea

    2016-04-01

    Soil water repellency (WR) and aggregate stability (AS) are two soil properties that are typically modified after burning and impose significant influence on subsequent hydrological and geomorphological dynamics. The response of AS and soil WR to fire depends upon how fire has influenced other key soil properties (e.g. soil OM, mineralogy). Meanwhile, routine thinning of trees and woody vegetation may alter soil properties (e.g. structure and porosity, wettability) by use of heavy machinery and species selection. The study area is situated along a north-facing slope of Mount Carmel national park (Israel). The selected sites are presented as a continuum of management intensity and fire histories. To date, the natural baseline of soil WR has yet to be thoroughly assessed and must be investigated alongside associated soil aggregating parameters in order to understand its overall impact. This study examines (i) the natural baseline of soil WR and physical properties compared to those of disturbed sites in the immediate (controlled burn) and long-term (10-years), and (ii) the interactions of soil properties with different control factors (management, surface cover, seasonal-temporal, burn temperature, soil organic carbon (OC) and mineralogy) in Mediterranean calcareous soils. Analysis of surface soil samples before and after destruction of WR by heating (200-600°C) was implemented using a combination of traditional methods and infrared (IR) spectroscopy. Management and surface cover type conditioned the wettability, soil structure and porosity of soils in the field, although this largely did not affect the heat-induced changes observed in the lab. A positive correlation was observed along an increasing temperature gradient, with relative maxima of MWD and BD reached by most soils at the threshold of 400-500°C. Preliminary analyses of soil OC (MIR) and mineralogical composition (VIS-NIR) support existing research regarding: (i) the importance of soil OC quality and

  3. Physicochemical and structural characterization of alkali soluble lignins from oil palm trunk and empty fruit-bunch fibers.

    Sun, R; Fang, J M; Tomkinson, J; Bolton, J

    1999-07-01

    Six alkali soluble lignin fractions were extracted from the cell wall materials of oil palm trunk and empty fruit-bunch (EFB) fibers with 5% NaOH, 10% NaOH, and 24% KOH/2% H(3)BO(3). All of the lignin fractions contained rather low amounts of associated neutral sugars (0.8-1.2%) and uronic acids (1.1-2.0%). The lignin fractions isolated with 5% NaOH from the lignified palm trunk and EFB fibers gave a relatively higher degree of polymerization as shown by weight-average molecular weights ranging between 2620 and 2840, whereas the lignin fractions isolated with 10% NaOH and 24% KOH/2% H(3)BO(3) from the partially delignified palm trunk and EFB fibers showed a relatively lower degree of polymerization, as shown by weight-average molecular weights ranging between 1750 and 1980. The results obtained by alkaline nitrobenzene oxidation showed that all of the lignin preparations contained a high proportion of noncondensed syringyl units with small amounts of noncondensed guaiacyl and fewer p-hydroxyphenyl units. The lignin fraction extracted with 5% NaOH from the lignified EFB fiber was mainly composed of beta-O-4 ether-linked units. Small amounts of 5-5', beta-5, and beta-beta' carbon-carbon linkages were also found to be present between the lignin structural units. Further studies showed that uronic, p-hydroxybenzoic, and ferulic acids in the cell walls of palm fibers were esterified to lignin. PMID:10552589

  4. Synthesis, crystal growth, structural and physicochemical studies of novel binary organic complex: 4-chloroaniline-3-hydroxy-4-methoxybenzaldehyde

    Sharma, K.P.; Reddi, R.S.B.; Bhattacharya, S. [Department of Chemistry, Centre of Advance Study, Banaras Hindu University, Varanasi-221005 (India); Rai, R.N., E-mail: rn_rai@yahoo.co.in [Department of Chemistry, Centre of Advance Study, Banaras Hindu University, Varanasi-221005 (India)

    2012-06-15

    The solid-state reaction, which is solvent free and green synthesis, has been adopted to explore the novel compound. The phase diagram of 4-chloroaniline (CA) and 3-hydroxy-4-methoxybenzaldehyde (HMB) system shows the formation of a novel 1:1 molecular complex, and two eutectics on either sides of complex. Thermochemical studies of complex and eutectics have been carried out for various properties such as heat of fusion, entropy of fusion, Jackson's parameters, interfacial energy and excess thermodynamic functions. The formation of molecular complex was also studied by IR, NMR, elemental analysis and UV-Vis absorption spectra. The single crystal of molecular complex was grown and its XRD study confirms the formation of complex and identifies the crystal structure and atomic packing of crystal of complex. Transmission spectra of grown crystal of the complex show 70% transmittance efficiency with cut off wavelength 412 nm. The band gap and refractive index of the crystal of complex have also been studied. - Graphical abstarct: Exploiting phase diagram study and solvent free synthesis a novel compound was synthesized and its single crystal growth, atomic packing, energy band gap and refractive index were studied. Highlights: Black-Right-Pointing-Pointer Novel organic complex was synthesized using Green or solvent free synthesis. Black-Right-Pointing-Pointer Phase diagram study provided the information to identify the worthy composition of novel complex. Black-Right-Pointing-Pointer The single crystal of the sufficient size was grown from the ethanol solution. Black-Right-Pointing-Pointer Crystal analysis suggested that the covalent bond is formed between the two parent compounds. Black-Right-Pointing-Pointer The transmittance of the crystal was found to be 70% and it was transparent from 412 to 850 nm.

  5. Synthesis, crystal growth, structural and physicochemical studies of novel binary organic complex: 4-chloroaniline–3-hydroxy-4-methoxybenzaldehyde

    The solid-state reaction, which is solvent free and green synthesis, has been adopted to explore the novel compound. The phase diagram of 4-chloroaniline (CA) and 3-hydroxy-4-methoxybenzaldehyde (HMB) system shows the formation of a novel 1:1 molecular complex, and two eutectics on either sides of complex. Thermochemical studies of complex and eutectics have been carried out for various properties such as heat of fusion, entropy of fusion, Jackson's parameters, interfacial energy and excess thermodynamic functions. The formation of molecular complex was also studied by IR, NMR, elemental analysis and UV–Vis absorption spectra. The single crystal of molecular complex was grown and its XRD study confirms the formation of complex and identifies the crystal structure and atomic packing of crystal of complex. Transmission spectra of grown crystal of the complex show 70% transmittance efficiency with cut off wavelength 412 nm. The band gap and refractive index of the crystal of complex have also been studied. - Graphical abstarct: Exploiting phase diagram study and solvent free synthesis a novel compound was synthesized and its single crystal growth, atomic packing, energy band gap and refractive index were studied. Highlights: ► Novel organic complex was synthesized using Green or solvent free synthesis. ► Phase diagram study provided the information to identify the worthy composition of novel complex. ► The single crystal of the sufficient size was grown from the ethanol solution. ► Crystal analysis suggested that the covalent bond is formed between the two parent compounds. ► The transmittance of the crystal was found to be 70% and it was transparent from 412 to 850 nm.

  6. The Aviation Adaptability of the New Structure Framework Material

    Jiang Jinsan

    2013-01-01

    In this study, 0Cr15Ni5Cu2Ti, stainless steel sheet material with high strength is introduced to replace light metal of magnesium as aviation structural material. The research on heat process technology is emphasized and overall welding of 0Cr15Ni5Cu2Ti sheet is employed, adopting such methods as argon arc protection, anti-deformation technology of hot bending forming, special heat treatment technology, five-axis numerical control machining. It is the first time for the new material applied t...

  7. The Aviation Adaptability of the New Structure Framework Material

    Jiang Jinsan

    2013-05-01

    Full Text Available In this study, 0Cr15Ni5Cu2Ti, stainless steel sheet material with high strength is introduced to replace light metal of magnesium as aviation structural material. The research on heat process technology is emphasized and overall welding of 0Cr15Ni5Cu2Ti sheet is employed, adopting such methods as argon arc protection, anti-deformation technology of hot bending forming, special heat treatment technology, five-axis numerical control machining. It is the first time for the new material applied to the external measuring set with pylon-balance of aircraft in our country, overcoming the weaknesses of the aluminum framework in strength and meeting the needs of new airborne equipment.

  8. Structural and Psycho-Social Limits to Climate Change Adaptation in the Great Barrier Reef Region

    Evans, Louisa S.; Hicks, Christina C.; Adger, W. Neil; Barnett, Jon; Perry, Allison L.; Fidelman, Pedro; Tobin, Renae

    2016-01-01

    Adaptation, as a strategy to respond to climate change, has limits: there are conditions under which adaptation strategies fail to alleviate impacts from climate change. Research has primarily focused on identifying absolute bio-physical limits. This paper contributes empirical insight to an emerging literature on the social limits to adaptation. Such limits arise from the ways in which societies perceive, experience and respond to climate change. Using qualitative data from multi-stakeholder workshops and key-informant interviews with representatives of the fisheries and tourism sectors of the Great Barrier Reef region, we identify psycho-social and structural limits associated with key adaptation strategies, and examine how these are perceived as more or less absolute across levels of organisation. We find that actors experience social limits to adaptation when: i) the effort of pursuing a strategy exceeds the benefits of desired adaptation outcomes; ii) the particular strategy does not address the actual source of vulnerability, and; iii) the benefits derived from adaptation are undermined by external factors. We also find that social limits are not necessarily more absolute at higher levels of organisation: respondents perceived considerable opportunities to address some psycho-social limits at the national-international interface, while they considered some social limits at the local and regional levels to be effectively absolute. PMID:26960200

  9. Structural and Psycho-Social Limits to Climate Change Adaptation in the Great Barrier Reef Region.

    Louisa S Evans

    Full Text Available Adaptation, as a strategy to respond to climate change, has limits: there are conditions under which adaptation strategies fail to alleviate impacts from climate change. Research has primarily focused on identifying absolute bio-physical limits. This paper contributes empirical insight to an emerging literature on the social limits to adaptation. Such limits arise from the ways in which societies perceive, experience and respond to climate change. Using qualitative data from multi-stakeholder workshops and key-informant interviews with representatives of the fisheries and tourism sectors of the Great Barrier Reef region, we identify psycho-social and structural limits associated with key adaptation strategies, and examine how these are perceived as more or less absolute across levels of organisation. We find that actors experience social limits to adaptation when: i the effort of pursuing a strategy exceeds the benefits of desired adaptation outcomes; ii the particular strategy does not address the actual source of vulnerability, and; iii the benefits derived from adaptation are undermined by external factors. We also find that social limits are not necessarily more absolute at higher levels of organisation: respondents perceived considerable opportunities to address some psycho-social limits at the national-international interface, while they considered some social limits at the local and regional levels to be effectively absolute.

  10. Augmented Adaptive Control of a Wind Turbine in the Presence of Structural Modes

    Frost, Susan A.; Balas, Mark J.; Wright, Alan D.

    2010-01-01

    Wind turbines operate in highly turbulent environments resulting in aerodynamic loads that can easily excite turbine structural modes, potentially causing component fatigue and failure. Two key technology drivers for turbine manufacturers are increasing turbine up time and reducing maintenance costs. Since the trend in wind turbine design is towards larger, more flexible turbines with lower frequency structural modes, manufacturers will want to develop methods to operate in the presence of these modes. Accurate models of the dynamic characteristics of new wind turbines are often not available due to the complexity and expense of the modeling task, making wind turbines ideally suited to adaptive control. In this paper, we develop theory for adaptive control with rejection of disturbances in the presence of modes that inhibit the controller. We use this method to design an adaptive collective pitch controller for a high-fidelity simulation of a utility-scale, variable-speed wind turbine operating in Region 3. The objective of the adaptive pitch controller is to regulate generator speed, accommodate wind gusts, and reduce the interference of certain structural modes in feedback. The control objective is accomplished by collectively pitching the turbine blades. The adaptive pitch controller for Region 3 is compared in simulations with a baseline classical Proportional Integrator (PI) collective pitch controller.

  11. Modified Adaptive Control for Region 3 Operation in the Presence of Wind Turbine Structural Modes

    Frost, Susan Alane; Balas, Mark J.; Wright, Alan D.

    2010-01-01

    Many challenges exist for the operation of wind turbines in an efficient manner that is reliable and avoids component fatigue and failure. Turbines operate in highly turbulent environments resulting in aerodynamic loads that can easily excite turbine structural modes, possibly causing component fatigue and failure. Wind turbine manufacturers are highly motivated to reduce component fatigue and failure that can lead to loss of revenue due to turbine down time and maintenance costs. The trend in wind turbine design is toward larger, more flexible turbines that are ideally suited to adaptive control methods due to the complexity and expense required to create accurate models of their dynamic characteristics. In this paper, we design an adaptive collective pitch controller for a high-fidelity simulation of a utility-scale, variable-speed horizontal axis wind turbine operating in Region 3. The objective of the adaptive pitch controller is to regulate generator speed, accommodate wind gusts, and reduce the excitation of structural modes in the wind turbine. The control objective is accomplished by collectively pitching the turbine blades. The adaptive collective pitch controller for Region 3 was compared in simulations with a baseline classical Proportional Integrator (PI) collective pitch controller. The adaptive controller will demonstrate the ability to regulate generator speed in Region 3, while accommodating gusts, and reducing the excitation of certain structural modes in the wind turbine.

  12. An Improved Variable Structure Adaptive Filter Design and Analysis for Acoustic Echo Cancellation

    A. Kar

    2015-04-01

    Full Text Available In this research an advance variable structure adaptive Multiple Sub-Filters (MSF based algorithm for single channel Acoustic Echo Cancellation (AEC is proposed and analyzed. This work suggests a new and improved direction to find the optimum tap-length of adaptive filter employed for AEC. The structure adaptation, supported by a tap-length based weight update approach helps the designed echo canceller to maintain a trade-off between the Mean Square Error (MSE and time taken to attain the steady state MSE. The work done in this paper focuses on replacing the fixed length sub-filters in existing MSF based AEC algorithms which brings refinements in terms of convergence, steady state error and tracking over the single long filter, different error and common error algorithms. A dynamic structure selective coefficient update approach to reduce the structural and computational cost of adaptive design is discussed in context with the proposed algorithm. Simulated results reveal a comparative performance analysis over proposed variable structure multiple sub-filters designs and existing fixed tap-length sub-filters based acoustic echo cancellers.

  13. Effect of the nature of a structure-forming additive on the physicochemical properties of zeolites and the activity of Zn-containing catalysts based on them in ethane aromatization

    Vosmerikova, L. N.; Barbashin, Ya. E.; Vosmerikov, A. V.

    2014-03-01

    The effect the nature of the structure-forming additive has on the physicochemical properties of synthesized zeolites and the activity of Zn-containing catalysts prepared on their basis in converting ethane into aromatic hydrocarbons is studied. It is shown that the structure-forming additive plays an important role in the hydrothermal synthesis of zeolites. It is found that the highest activity and stability in ethane aromatization is exhibited by a catalyst based on a zeolite synthesized using hexamethylenediamine as a template.

  14. Cutthroat cooperation: the effects of team role decisions on adaptation to alternative reward structures

    B. Beersma; J.R. Hollenbeck; D.E. Conlon; S.E. Humphrey; H. Moon; D.R. Ilgen

    2009-01-01

    Structural Adaptation Theory proposes that it is more difficult for teams to change from competitive to cooperative reward conditions than it is for them to change in the opposite direction, and this has been labeled the cutthroat cooperation effect [Johnson, M. D., Hollenbeck, J. R., Ilgen, D. R.,

  15. Ways and Means of Adapting Culture and Structure: Case Studies. Support Document 1

    Clayton, Berwyn; Fisher, Thea; Harris, Roger; Bateman, Andrea; Brown, Mike

    2008-01-01

    The resource in this support document is a set of small case studies, offering insights into how a range of organisations have gone about adapting their organisational structure and/or culture to enhance their capability. Key elements of each case are presented with a particular emphasis on: (1) the principles that have underpinned each approach…

  16. Adaptive stability as the conceptual model for managing Russian corporate structures in modern geoeconomic environment

    Olga Andreeva

    2014-01-01

    This article represents the author's approach to provision of adaptive stability of corporate structures as the essential characteristic in a highly moderated geoeconomic uncertainty environment. The analysis of current theoretical and methodological background of modern corporate management, such as network economics theory, financial globalization theory, uncertainty theory within conspiracy theories group, economic and mathematical instruments in supporting management decision making, incl...

  17. Parallel structures for disaster risk reduction and climate change adaptation in Southern Africa

    Per Becker

    2013-01-01

    Full Text Available During the last decade, the interest of the international community in the concepts of disaster risk reduction and climate change adaptation has been growing immensely. Even though an increasing number of scholars seem to view these concepts as two sides of the same coin (at least when not considering the potentially positive effects of climate change, in practice the two concepts have developed in parallel rather than in an integrated manner when it comes to policy, rhetoric and funding opportunities amongst international organisations and donors. This study investigates the extent of the creation of parallel structures for disaster risk reduction and climate change adaptation in the Southern African Development Community (SADC region. The chosen methodology for the study is a comparative case study and the data are collected through focus groups and content analysis of documentary sources, as well as interviews with key informants. The results indicate that parallel structures for disaster risk reduction and climate change adaptation have been established in all but one of the studied countries. The qualitative interviews performed in some of the countries indicate that stakeholders in disaster risk reduction view this duplication of structures as unfortunate, inefficient and a fertile setup for conflict over resources for the implementation of similar activities. Additional research is called for in order to study the concrete effects of having these parallel structures as a foundation for advocacy for more efficient future disaster risk reduction and climate change adaptation.

  18. Design of control adaptability system model for TV media organization structure

    WANG Dong-dong; WANG Ya-lin; MA Tao

    2008-01-01

    To resolve the control adaptability problem of TV media in complex competitive environment, a con-trol system model of TV media organization structure was designed. Based on the designed system model for TV media organization structure, the relations among the main factors of the system constitution, missions, organi-zing decision entity, and carrying bodies were analyzed. By means of applying multi-objective decision method and complex control system theory, and combining the integration model of TV media organization structure, the basic model was concluded and the corresponding parameters were designed. The current organization process of TV media is analyzed by this model, which comes to the adaptability appearance with different parameters. The results indicate that the model can estimate current TV media organization structure for the chain appearance of communications and the correlation between platforms and policy-making agencies.

  19. Designing of Elastoplastic Adaptive Truss Structures with the Use of Particle Swarm Optimization

    Jacek Szklarski; Marcin Wikło

    2015-01-01

    In the paper we demonstrate how Particle Swarm Optimization (PSO) can be employed to solve the Adaptive Impact Absorption (AIA) problem. We consider a truss structure which is subjected to impact loads. Stiff bars can be replaced by elastoplastic fuses which control theirs dynamical response. The point of optimization is to maximize or minimize a given objective function by redesigning the structure. This is realized by redistributing the initial mass, finding proper fuse localizations and ad...

  20. Molecular dynamics modelling of mechanical properties of polymers for adaptive aerospace structures

    Papanikolaou, Michail; Drikakis, Dimitris; Asproulis, Nikolaos

    2015-02-01

    The features of adaptive structures depend on the properties of the supporting materials. For example, morphing wing structures require wing skin materials, such as rubbers that can withstand the forces imposed by the internal mechanism while maintaining the required aerodynamic properties of the aircraft. In this study, Molecular Dynamics and Minimization simulations are being used to establish well-equilibrated models of Ethylene-Propylene-Diene Monomer (EPDM) elastomer systems and investigate their mechanical properties.

  1. Structure identification and adaptive synchronization of uncertain general complex dynamical networks

    This Letter proposes an approach to identify the topological structure and unknown parameters for uncertain general complex networks simultaneously. By designing effective adaptive controllers, we achieve synchronization between two complex networks. The unknown network topological structure and system parameters of uncertain general complex dynamical networks are identified simultaneously in the process of synchronization. Several useful criteria for synchronization are given. Finally, an illustrative example is presented to demonstrate the application of the theoretical results.

  2. Application of adaptive wavelet networks for vibration control of base isolated structures

    Karimi, Hamid Reza; Zapateiro, Mauricio; Luo, Ningsu

    2010-01-01

    This paper presents an application of wavelet networks (WNs) in identification and control design for a class of structures equipped with a type of semiactive actuators, which are called magnetorheological (MR) dampers. The nonlinear model is identified based on a WN framework. Based on the technique of feedback linearization, supervisory control and H∞ control, an adaptive control strategy is developed to compensate for the nonlinearity in the structure so as to enhance the response of the s...

  3. An adaptive model reduction strategy for post-buckling analysis of stiffened structures

    Barrière, Ludovic; Marguet, Steven; Castanié, Bruno; Cresta, Philippe; Passieux, Jean-Charles

    2013-01-01

    The finite element simulation of structures subjected to post-buckling still faces computational limits, especially for large stiffened structures. Several solving strategies have already been proposed in response to this issue. Among them are the adaptive model reduction solving techniques which demonstrated their ability to drastically reduce the number of unknowns as well as to control the approximation error of solving non-linear problems like post-buckling. The challenges regarding these...

  4. Scale-adaptive tensor algebra for local many-body methods of electronic structure theory

    Liakh, Dmitry I [ORNL

    2014-01-01

    While the formalism of multiresolution analysis (MRA), based on wavelets and adaptive integral representations of operators, is actively progressing in electronic structure theory (mostly on the independent-particle level and, recently, second-order perturbation theory), the concepts of multiresolution and adaptivity can also be utilized within the traditional formulation of correlated (many-particle) theory which is based on second quantization and the corresponding (generally nonorthogonal) tensor algebra. In this paper, we present a formalism called scale-adaptive tensor algebra (SATA) which exploits an adaptive representation of tensors of many-body operators via the local adjustment of the basis set quality. Given a series of locally supported fragment bases of a progressively lower quality, we formulate the explicit rules for tensor algebra operations dealing with adaptively resolved tensor operands. The formalism suggested is expected to enhance the applicability and reliability of local correlated many-body methods of electronic structure theory, especially those directly based on atomic orbitals (or any other localized basis functions).

  5. A low-complexity adaptive beamformer for ultrasound imaging using structured covariance matrix.

    Asl, Babak Mohammadzadeh; Mahloojifar, Ali

    2012-04-01

    In recent years, adaptive beamforming methods have been successfully applied to medical ultrasound imaging, resulting in simultaneous improvement in imaging resolution and contrast. These improvements have been achieved at the expense of higher computational complexity, with respect to the conventional non-adaptive delay-and-sum (DAS) beamformer, in which computational complexity is proportional to the number of elements, O(M). The computational overhead results from the covariance matrix inversion needed for computation of the adaptive weights, the complexity of which is cubic with the subarray size, O(L(3)). This is a computationally intensive procedure, which makes the implementation of adaptive beamformers less attractive in spite of their advantages. Considering that, in medical ultrasound applications, most of the energy is scattered from angles close to the steering angle, assuming spatial stationarity is a good approximation, allowing us to assume the Toeplitz structure for the estimated covariance matrix. Based on this idea, in this paper, we have applied the Toeplitz structure to the spatially smoothed covariance matrix by averaging the entries along all subdiagonals. Because the inverse of the resulting Toeplitz covariance matrix can be computed in O(L(2)) operations, this technique results in a greatly reduced computational complexity. By using simulated and experimental RF data-point targets as well as cyst phantoms-we show that the proposed low-complexity adaptive beamformer significantly outperforms the DAS and its performance is comparable to that of the minimum variance beamformer, with reduced computational complexity. PMID:22547277

  6. [Phospholipids and structural modification of tissues and cell membranes for adaptation in high altitude mountains].

    Iakovlev, V M; Vishnevskiĭ, A A; Shanazarov, A S

    2012-01-01

    The nature of the impact of physical factors of high altitudes (3200 m) on the lipids of tissues and membranes of animals was researched. It was established that the adaptation process in Wistar rats was followed by peroxide degradation and subsequent modification of the phospholipids' structure of tissues and microsomal membranes. Adaptive phospholipids reconstruction takes place in microsomal membranes in the tissues of the lungs, brain, liver and skeletal muscles. Together with this, the amount of phosphatidylinositol and phosphatidic acid accumulates, indicating that the hydrolysis of phosphatidylinositol-4, 5 biphosphate to diacylglycerol and secondary messenger--inositol triphosphate, occurs. A decrease in temperature adaptation (+10 degrees C) leads to a more noticeable shift in peroxide oxidation of lipids, phospholipid structure in the tissues and membranes rather than adaptation in thermoneutral conditions (+30 degrees C). Modification of lipid composition of tissues and cell membranes in the highlands obviously increases the adaptive capabilities of cells of the whole body: physical performance and resistance to hypoxia increases in animals. PMID:22586936

  7. A new adaptive mesh refinement data structure with an application to detonation

    Ji, Hua; Lien, Fue-Sang; Yee, Eugene

    2010-11-01

    A new Cell-based Structured Adaptive Mesh Refinement (CSAMR) data structure is developed. In our CSAMR data structure, Cartesian-like indices are used to identify each cell. With these stored indices, the information on the parent, children and neighbors of a given cell can be accessed simply and efficiently. Owing to the usage of these indices, the computer memory required for storage of the proposed AMR data structure is only {5}/{8} word per cell, in contrast to the conventional oct-tree [P. MacNeice, K.M. Olson, C. Mobary, R. deFainchtein, C. Packer, PARAMESH: a parallel adaptive mesh refinement community toolkit, Comput. Phys. Commun. 330 (2000) 126] and the fully threaded tree (FTT) [A.M. Khokhlov, Fully threaded tree algorithms for adaptive mesh fluid dynamics simulations, J. Comput. Phys. 143 (1998) 519] data structures which require, respectively, 19 and 2{3}/{8} words per cell for storage of the connectivity information. Because the connectivity information (e.g., parent, children and neighbors) of a cell in our proposed AMR data structure can be accessed using only the cell indices, a tree structure which was required in previous approaches for the organization of the AMR data is no longer needed for this new data structure. Instead, a much simpler hash table structure is used to maintain the AMR data, with the entry keys in the hash table obtained directly from the explicitly stored cell indices. The proposed AMR data structure simplifies the implementation and parallelization of an AMR code. Two three-dimensional test cases are used to illustrate and evaluate the computational performance of the new CSAMR data structure.

  8. Adaptive solution of some steady-state fluid-structure interaction problems

    This paper presents a general integrated and coupled formulation for modeling the steady-state interaction of a viscous incompressible flow with an elastic structure undergoing large displacements (geometric non-linearities). This constitutes an initial step towards developing a sensitivity analysis formulation for this class of problems. The formulation uses velocity and pressures as unknowns in a flow domain and displacements in the structural components. An interface formulation is presented that leads to clear and simple finite element implementation of the equilibrium conditions at the fluid-solid interface. Issues of error estimation and mesh adaptation are discussed. The adaptive formulation is verified on a problem with a closed form solution. It is then applied to a sample case for which the structure undergoes large displacements induced by the flow. (author)

  9. Adaptive Neuro-Fuzzy Inference System Models for Force Prediction of a Mechatronic Flexible Structure

    Achiche, S.; Shlechtingen, M.; Raison, M.;

    2016-01-01

    This paper presents the results obtained from a research work investigating the performance of different Adaptive Neuro-Fuzzy Inference System (ANFIS) models developed to predict excitation forces on a dynamically loaded flexible structure. For this purpose, a flexible structure is equipped with...... influence of the sampling frequency and sensor location on the model performance is investigated. The results obtained in this paper show that ANFIS models can be used to set up reliable force predictors for dynamical loaded flexible structures, when a certain degree of inaccuracy is accepted. Furthermore...

  10. Adaptation to structural modifications of the human vocal tract during speech: Electropalatographic measures

    Aasland, Wendi A.; Baum, Shari R.; McFarland, David H.

    2001-05-01

    Structural modifications to the vocal tract force speakers to alter their previously learned articulatory patterns in order to produce perceptually adequate speech. Previous research has shown that acoustic output in the production of alveolar consonants changes during adaptation to structural alterations of the palate, but to date, little is known regarding exactly how these changes result kinematically. The present study examines the adjustments made to tongue-palate contact patterns, measured using electropalatography (EPG), during adaptation to a palatal perturbation for the fricative [s]. Productions of the nonsense word [asa] were elicited in nine subjects at five time intervals, 15 min apart, while speakers wore electropalates modified with a thicker-than-normal alveolar ridge. Between measurement intervals, speakers read [s]-laden passages to promote adaptation. Productions were also elicited with an unperturbed electropalate in place to characterize normal articulation. Electropalatographic analyses revealed a posterior shift in center of gravity of tongue-palate contact, alterations in the width of the medial groove necessary for [s] production, and increased variability in productions, which may reflect the instability of the new motor programs. Results are discussed in relation to the development of adaptive articulatory programs in speech motor control. [Work supported by NSERC and a FRSQ Bourse de Formation.

  11. Structural bistability in quasi-hard-discs under adaptive circular confinement

    Williams, Ian; Oguz, Erdal C.; Bartlett, Paul; Loewen, Hartmut; Royall, C. Patrick

    2014-03-01

    The behaviour of materials under spatial confinement is dramatically different from that in the bulk. The exact nature of behavioural modification in confined systems is strongly dependent on the boundary enclosing the system with soft walls inducing different phenomena than similar hard walls. Here we present a quasi-two-dimensional colloidal model system confined by an adaptive circular boundary defined using holographic optical tweezers. The adaptive boundary is deformable, enabling mechanical measurements of pressure and leading to the observation of a novel structural bistability between concentric particle layering and locally hexagonal configurations at high density. These findings are reproduced in analogous Monte Carlo simulations. Additionally, shearing the confined system drives the this bistability resulting in the observation of a novel oscillatory state characterised by periodically self-similar structural organisation. Under varying conditions, both shear melted and rigid-body-like flow behaviour is observed.

  12. Single-Pass GPU-Raycasting for Structured Adaptive Mesh Refinement Data

    Kaehler, Ralf

    2012-01-01

    Structured Adaptive Mesh Refinement (SAMR) is a popular numerical technique to study processes with high spatial and temporal dynamic range. It reduces computational requirements by adapting the lattice on which the underlying differential equations are solved to most efficiently represent the solution. Particularly in astrophysics and cosmology such simulations now can capture spatial scales ten orders of magnitude apart and more. The irregular locations and extensions of the refined regions in the SAMR scheme and the fact that different resolution levels partially overlap, poses a challenge for GPU-based direct volume rendering methods. kD-trees have proven to be advantageous to subdivide the data domain into non-overlapping blocks of equally sized cells, optimal for the texture units of current graphics hardware, but previous GPU-supported raycasting approaches for SAMR data using this data structure required a separate rendering pass for each node, preventing the application of many advanced lighting sche...

  13. Adaptations for economical bipedal running: the effect of limb structure on three-dimensional joint mechanics

    Rubenson, Jonas; Lloyd, David G.; Heliams, Denham B.; Besier, Thor F.; Fournier, Paul A.

    2010-01-01

    The purpose of this study was to examine the mechanical adaptations linked to economical locomotion in cursorial bipeds. We addressed this question by comparing mass-matched humans and avian bipeds (ostriches), which exhibit marked differences in limb structure and running economy. We hypothesized that the nearly 50 per cent lower energy cost of running in ostriches is a result of: (i) lower limb-swing mechanical power, (ii) greater stance-phase storage and release of elastic energy, and (iii...

  14. New Low Cost Structure for Dual Axis Mount Solar Tracking System Using Adaptive Solar Sensor

    Argeseanu, Alin; Ritchie, Ewen; Leban, Krisztina Monika

    2010-01-01

    A solar tracking system is designed to optimize the operation of solar energy receivers. The objective of this paper is proposing a new tracking system structure with two axis. The success strategy of this new project focuses on the economical analysis of solar energy. Therefore it is important to...... determine the most cost effective design, to consider the costs of production and maintenance, and operating. The proposed tracking system uses a new solar sensor position with an adaptive feature....

  15. Block Structured Adaptive Mesh and Time Refinement for Hybrid, Hyperbolic + N-body Systems

    Miniati, Francesco; Colella, Phillip

    2006-01-01

    We present a new numerical algorithm for the solution of coupled collisional and collisionless systems, based on the block structured adaptive mesh and time refinement strategy (AMR). We describe the issues associated with the discretization of the system equations and the synchronization of the numerical solution on the hierarchy of grid levels. We implement a code based on a higher order, conservative and directionally unsplit Godunov's method for hydrodynamics; a symmetric, time centered m...

  16. A new adaptive variable structure control for chaotic synchronization and secure communication

    A novel adaptive complementary variable structure control is proposed in this paper for chaotic synchronization. The bounded parameters of the model approximation error and the external disturbance are all regarded as unknown constants in this paper. Based on Lyapunov's stability theory and the Babalat's lemma the proposed controller has been shown to render the synchronous error to zero. The Duffing-Holmes oscillator was used as an illustrative example. Simulation results validated that the proposed scheme in the application of secure communication

  17. Experimental study of robustness in adaptive control for large flexible structures

    Ih, Che-Hang Charles; Bayard, David S.; Ahmed, Asif; Wang, Shyh Jong

    1990-01-01

    An experimental study is performed to investigate the robustness of model reference adaptive control for the large flexible structures control application. The main nonidealities of concern are unmodeled dynamics, input saturation, and time delay effects (here, actuator and sensor dynamics are lumped into the last item for convenience). This study focuses on the robustness with respect to input saturation and time delay effects, since robustness to unmodeled dynamics is inherent to the basic algorithm and has been demonstrated experimentally elsewhere.

  18. A Patch-based Partitioner for Structured Adaptive Mesh Refinement : Implementation and Evaluation

    Vakili, Abbas

    2008-01-01

    To increase the speed of computer simulations we solve partial differential equations (PDEs) using structured adaptive mesh refinement (SAMR). During the execution of an SAMR-application, finer grids are superimposed dynamically on coarser grids where a more accurate solution is needed in the computation area. To further decrease the computation time, we use parallel computers and divide the computational work between the processors. This gives rise to challenging load balancing problem. The ...

  19. The impact of priming on new technology appropriation: An extension of adaptive structuration theory

    Comi, Alice; Eppler, Martin J.; Herrmann, Andreas

    2012-01-01

    In this paper we present a theoretical and methodological extension of Adaptive Structuration Theory (AST), as applicable to information systems (IS), by showing how technology appropriation can be influenced and measured. We address the questions of how people react to novel user interfaces – specifically, an interactive online product configurator – and if that reaction can be influenced through two priming mechanisms. To answer these questions, we experimentally assess if priming use...

  20. Application of new advanced CNN structure with adaptive thresholds to color edge detection

    Deng, Shaojiang; Tian, Yuan; Hu, Xipeng; Wei, Pengcheng; Qin, Mingfu

    2012-04-01

    Color edge detection is much more efficient than gray scale detection when edges exist at the boundary between regions of different colors with no change in intensity. This paper presents adaptive templates, which are capable of detecting various color and intensity changes in color image. To avoid conception of multilayer proposed in literatures, modification has been done to the CNN structure. This modified structure allows a matrix C, which carries the change information of pixels, to replace the control parts in the basic CNN equation. This modification is necessary because in multilayer structure, it faces the challenge of how to represent the intrinsic relationship among each primary layer. Additionally, in order to enhance the accuracy of edge detection, adaptive detection threshold is employed. The adaptive thresholds are considered to be alterable criteria in designing matrix C. The proposed synthetic system not only avoids the problem which is engendered by multi-layers but also exploits full information of pixels themselves. Experimental results prove that the proposed method is efficient.

  1. Hierarchical structured robust adaptive attitude controller design for reusable launch vehicles

    Guangxue Yu; Huifeng Li

    2015-01-01

    Reentry attitude control for reusable launch vehicles (RLVs) is chal enging due to the characters of fast nonlinear dy-namics and large flight envelop. A hierarchical structured attitude control system for an RLV is proposed and an unpowered RLV con-trol model is developed. Then, the hierarchical structured control frame consisting of attitude control er, compound control strategy and control al ocation is presented. At the core of the design is a robust adaptive control (RAC) law based on dual loop time-scale separation. A radial basis function neural network (RBFNN) is implemented for compensation of uncertain model dynamics and external disturbances in the inner loop. And then the robust op-timization is applied in the outer loop to guarantee performance robustness. The overal control design frame retains the simplicity in design while simultaneously assuring the adaptive and robust performance. The hierarchical structured robust adaptive con-trol er (HSRAC) incorporates flexibility into the design with regard to control er versatility to various reentry mission requirements. Simulation results show that the improved tracking performance is achieved by means of RAC.

  2. Fibrin Networks Support Recurring Mechanical Loads by Adapting their Structure across Multiple Scales.

    Kurniawan, Nicholas A; Vos, Bart E; Biebricher, Andreas; Wuite, Gijs J L; Peterman, Erwin J G; Koenderink, Gijsje H

    2016-09-01

    Tissues and cells sustain recurring mechanical loads that span a wide range of loading amplitudes and timescales as a consequence of exposure to blood flow, muscle activity, and external impact. Both tissues and cells derive their mechanical strength from fibrous protein scaffolds, which typically have a complex hierarchical structure. In this study, we focus on a prototypical hierarchical biomaterial, fibrin, which is one of the most resilient naturally occurring biopolymers and forms the structural scaffold of blood clots. We show how fibrous networks composed of fibrin utilize irreversible changes in their hierarchical structure at different scales to maintain reversible stress stiffening up to large strains. To trace the origin of this paradoxical resilience, we systematically tuned the microstructural parameters of fibrin and used a combination of optical tweezers and fluorescence microscopy to measure the interactions of single fibrin fibers for the first time, to our knowledge. We demonstrate that fibrin networks adapt to moderate strains by remodeling at the network scale through the spontaneous formation of new bonds between fibers, whereas they adapt to high strains by plastic remodeling of the fibers themselves. This multiscale adaptation mechanism endows fibrin gels with the remarkable ability to sustain recurring loads due to shear flows and wound stretching. Our findings therefore reveal a microscopic mechanism by which tissues and cells can balance elastic nonlinearity and plasticity, and thus can provide microstructural insights into cell-driven remodeling of tissues. PMID:27602730

  3. Physico-chemical study of coating plasma duplex alumina/hydroxyapatite for medical applications relation elaboration/structure/properties(dissolution/adherence/residual constraints)

    The physico-chemical behavior of porous ceramics depositing is studied in order to use them to favour the biological fixing of hip prosthesis fixed without cement. Alumina depositing, hydroxyapatite depositing and duplex (the both together) have been realized by plasma projection on a substrate in Ti-6Al-V. Tests of dissolution have been made. An original method of sound followed by radioactive tracers has allowed to establish an order of phases degradation and to consider the kinetics of calcium ions in function of several parameters of tests. (N.C.)

  4. A Solution Adaptive Structured/Unstructured Overset Grid Flow Solver with Applications to Helicopter Rotor Flows

    Duque, Earl P. N.; Biswas, Rupak; Strawn, Roger C.

    1995-01-01

    This paper summarizes a method that solves both the three dimensional thin-layer Navier-Stokes equations and the Euler equations using overset structured and solution adaptive unstructured grids with applications to helicopter rotor flowfields. The overset structured grids use an implicit finite-difference method to solve the thin-layer Navier-Stokes/Euler equations while the unstructured grid uses an explicit finite-volume method to solve the Euler equations. Solutions on a helicopter rotor in hover show the ability to accurately convect the rotor wake. However, isotropic subdivision of the tetrahedral mesh rapidly increases the overall problem size.

  5. Formal structure and culture : organizational influence on adaptive capacity to climate change in quasi-public network sectors

    2012-01-01

    List of articles. The articles are removed from the thesis due to copyright restrictions. Article 1: Inderberg, Tor Håkon (2011). Institutional constraints to adaptive capacity: adaptability to climate change in the Norwegian electricity Sector. Local Environment, 16(04), pp. 303–317. doi:10.1080/13549839.2011.569538 Article 2: Inderberg, Tor Håkon (2012). Governance for adaptive capacity in the Swedish electricity industry: Do changes in structure and culture m...

  6. Adaptive finite element modeling of direct current resistivity in 2-D generally anisotropic structures

    Yan, Bo; Li, Yuguo; Liu, Ying

    2016-07-01

    In this paper, we present an adaptive finite element (FE) algorithm for direct current (DC) resistivity modeling in 2-D generally anisotropic conductivity structures. Our algorithm is implemented on an unstructured triangular mesh that readily accommodates complex structures such as topography and dipping layers and so on. We implement a self-adaptive, goal-oriented grid refinement algorithm in which the finite element analysis is performed on a sequence of refined grids. The grid refinement process is guided by an a posteriori error estimator. The problem is formulated in terms of total potentials where mixed boundary conditions are incorporated. This type of boundary condition is superior to the Dirichlet type of conditions and improves numerical accuracy considerably according to model calculations. We have verified the adaptive finite element algorithm using a two-layered earth with azimuthal anisotropy. The FE algorithm with incorporation of mixed boundary conditions achieves high accuracy. The relative error between the numerical and analytical solutions is less than 1% except in the vicinity of the current source location, where the relative error is up to 2.4%. A 2-D anisotropic model is used to demonstrate the effects of anisotropy upon the apparent resistivity in DC soundings.

  7. Algorithms and data structures for massively parallel generic adaptive finite element codes

    Bangerth, Wolfgang

    2011-12-01

    Today\\'s largest supercomputers have 100,000s of processor cores and offer the potential to solve partial differential equations discretized by billions of unknowns. However, the complexity of scaling to such large machines and problem sizes has so far prevented the emergence of generic software libraries that support such computations, although these would lower the threshold of entry and enable many more applications to benefit from large-scale computing. We are concerned with providing this functionality for mesh-adaptive finite element computations. We assume the existence of an "oracle" that implements the generation and modification of an adaptive mesh distributed across many processors, and that responds to queries about its structure. Based on querying the oracle, we develop scalable algorithms and data structures for generic finite element methods. Specifically, we consider the parallel distribution of mesh data, global enumeration of degrees of freedom, constraints, and postprocessing. Our algorithms remove the bottlenecks that typically limit large-scale adaptive finite element analyses. We demonstrate scalability of complete finite element workflows on up to 16,384 processors. An implementation of the proposed algorithms, based on the open source software p4est as mesh oracle, is provided under an open source license through the widely used deal.II finite element software library. © 2011 ACM 0098-3500/2011/12-ART10 $10.00.

  8. Adaptive modeling, identification, and control of dynamic structural systems. I. Theory

    Safak, Erdal

    1989-01-01

    A concise review of the theory of adaptive modeling, identification, and control of dynamic structural systems based on discrete-time recordings is presented. Adaptive methods have four major advantages over the classical methods: (1) Removal of the noise from the signal is done over the whole frequency band; (2) time-varying characteristics of systems can be tracked; (3) systems with unknown characteristics can be controlled; and (4) a small segment of the data is needed during the computations. Included in the paper are the discrete-time representation of single-input single-output (SISO) systems, models for SISO systems with noise, the concept of stochastic approximation, recursive prediction error method (RPEM) for system identification, and the adaptive control. Guidelines for model selection and model validation and the computational aspects of the method are also discussed in the paper. The present paper is the first of two companion papers. The theory given in the paper is limited to that which is necessary to follow the examples for applications in structural dynamics presented in the second paper.

  9. Single-pass GPU-raycasting for structured adaptive mesh refinement data

    Kaehler, Ralf; Abel, Tom

    2013-01-01

    Structured Adaptive Mesh Refinement (SAMR) is a popular numerical technique to study processes with high spatial and temporal dynamic range. It reduces computational requirements by adapting the lattice on which the underlying differential equations are solved to most efficiently represent the solution. Particularly in astrophysics and cosmology such simulations now can capture spatial scales ten orders of magnitude apart and more. The irregular locations and extensions of the refined regions in the SAMR scheme and the fact that different resolution levels partially overlap, poses a challenge for GPU-based direct volume rendering methods. kD-trees have proven to be advantageous to subdivide the data domain into non-overlapping blocks of equally sized cells, optimal for the texture units of current graphics hardware, but previous GPU-supported raycasting approaches for SAMR data using this data structure required a separate rendering pass for each node, preventing the application of many advanced lighting schemes that require simultaneous access to more than one block of cells. In this paper we present the first single-pass GPU-raycasting algorithm for SAMR data that is based on a kD-tree. The tree is efficiently encoded by a set of 3D-textures, which allows to adaptively sample complete rays entirely on the GPU without any CPU interaction. We discuss two different data storage strategies to access the grid data on the GPU and apply them to several datasets to prove the benefits of the proposed method.

  10. Physicochemical Properties and Structure Characterization of Two Polysaccharides from Tricholoma matsutake%松茸多糖的理化性质与结构表征

    刘刚; 王辉; 周本宏

    2013-01-01

    Objective: To investigate the physicochemical properties and structure characterization of two polysaccharides MTS1 -2 isolated from T. matsutake. Method: The content of glucuronic acid and S042- were determined by m-hydroxydiphenyl method and barium sulfate turbidimetry. The specific rotation and the element proportion of C and H were determined by an automatic polarimeter and an elementary analyzer. The molecular weight and the purity of the polysaccharides were analyzed by high performance gel permeation chromatography ( HPGPC ). After completely acid-hydrolyzed and trimethylsilyl derivatized, the monosaccharides in the polysaccharides were analyzed by gas chromatography ( GC ). Meanwhile, the structural investigation of the polysaccharides was characterized by ultraviolet-visible spectrophotometry ( UV-VIS ), Fourier transform infrared spectrophotometry ( FTIR ), one and two-dimensional nuclear magnetic resonance spectroscopy ( NMR ). Result: The molecular weight of the two polysaccharides was 180 357 and 5 939, respectively. MTS-1 from T. matsutake contained glucose, xylose and galactose in a molar ratio of 16. 77: 1. 63: 1. The main backbone of MTS-1 was composed of a-D-glucose linked by 1→6 glucoside bond along with α-D-xylose and β-D-galactose in the side chains. MTS-2 was identified to be composed of glucose units. According to the comprehensive analysis,the backbone of MTS-2 consisted of 36-unit β-D-glucoses with 1→6 glycosidic linkage. Conclusion: The results provide basis for the further research on the structural characteristics and functions of the polysaccharides from T. matsutake.%目的:研究从松茸中提取的两个多糖MTS1-2的理化性质和结构表征.方法:采用间羟联苯法和硫酸钡浊度法测定两个多糖的糖醛酸含量及硫酸根含量;自动旋光仪和元素分析仪测定多糖的比旋光度和C、H元素组成比例;高效凝胶渗透色谱(HPGPC)对多糖的纯度和相对分子质量(Mr)进行分析和测

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

    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 engin

  12. A Unifying Framework for Adaptive Radar Detection in Homogeneous Plus Structured Interference— Part II: Detectors Design

    Ciuonzo, Domenico; De Maio, Antonio; Orlando, Danilo

    2016-06-01

    This paper deals with the problem of adaptive multidimensional/multichannel signal detection in homogeneous Gaussian disturbance with unknown covariance matrix and structured (unknown) deterministic interference. The aforementioned problem extends the well-known Generalized Multivariate Analysis of Variance (GMANOVA) tackled in the open literature. In a companion paper, we have obtained the Maximal Invariant Statistic (MIS) for the problem under consideration, as an enabling tool for the design of suitable detectors which possess the Constant False-Alarm Rate (CFAR) property. Herein, we focus on the development of several theoretically-founded detectors for the problem under consideration. First, all the considered detectors are shown to be function of the MIS, thus proving their CFARness property. Secondly, coincidence or statistical equivalence among some of them in such a general signal model is proved. Thirdly, strong connections to well-known simpler scenarios found in adaptive detection literature are established. Finally, simulation results are provided for a comparison of the proposed receivers.

  13. Adapting federated cyberinfrastructure for shared data collection facilities in structural biology

    It has been difficult, historically, to manage and maintain early-stage experimental data collected by structural biologists in synchrotron facilities. This work describes a prototype system that adapts existing federated cyberinfrastructure technology and techniques to manage collected data at synchrotrons and to facilitate the efficient and secure transfer of data to the owner's home institution. Early stage experimental data in structural biology is generally unmaintained and inaccessible to the public. It is increasingly believed that this data, which forms the basis for each macromolecular structure discovered by this field, must be archived and, in due course, published. Furthermore, the widespread use of shared scientific facilities such as synchrotron beamlines complicates the issue of data storage, access and movement, as does the increase of remote users. This work describes a prototype system that adapts existing federated cyberinfrastructure technology and techniques to significantly improve the operational environment for users and administrators of synchrotron data collection facilities used in structural biology. This is achieved through software from the Virtual Data Toolkit and Globus, bringing together federated users and facilities from the Stanford Synchrotron Radiation Lightsource, the Advanced Photon Source, the Open Science Grid, the SBGrid Consortium and Harvard Medical School. The performance and experience with the prototype provide a model for data management at shared scientific facilities

  14. An Matching Method for Vehicle-borne Panoramic Image Sequence Based on Adaptive Structure from Motion Feature

    ZHANG Zhengpeng

    2015-10-01

    Full Text Available Panoramic image matching method with the constraint condition of local structure from motion similarity feature is an important method, the process requires multivariable kernel density estimations for the structure from motion feature used nonparametric mean shift. Proper selection of the kernel bandwidth is a critical step for convergence speed and accuracy of matching method. Variable bandwidth with adaptive structure from motion feature for panoramic image matching method has been proposed in this work. First the bandwidth matrix is defined using the locally adaptive spatial structure of the sampling point in spatial domain and optical flow domain. The relaxation diffusion process of structure from motion similarity feature is described by distance weighting method of local optical flow feature vector. Then the expression form of adaptive multivariate kernel density function is given out, and discusses the solution of the mean shift vector, termination conditions, and the seed point selection method. The final fusions of multi-scale SIFT the features and structure features to establish a unified panoramic image matching framework. The sphere panoramic images from vehicle-borne mobile measurement system are chosen such that a comparison analysis between fixed bandwidth and adaptive bandwidth is carried out in detail. The results show that adaptive bandwidth is good for case with the inlier ratio changes and the object space scale changes. The proposed method can realize the adaptive similarity measure of structure from motion feature, improves the correct matching points and matching rate, experimental results have shown our method to be robust.

  15. Adaptable structural synthesis using advanced analysis and optimization coupled by a computer operating system

    Sobieszczanski-Sobieski, J.; Bhat, R. B.

    1979-01-01

    A finite element program is linked with a general purpose optimization program in a 'programing system' which includes user supplied codes that contain problem dependent formulations of the design variables, objective function and constraints. The result is a system adaptable to a wide spectrum of structural optimization problems. In a sample of numerical examples, the design variables are the cross-sectional dimensions and the parameters of overall shape geometry, constraints are applied to stresses, displacements, buckling and vibration characteristics, and structural mass is the objective function. Thin-walled, built-up structures and frameworks are included in the sample. Details of the system organization and characteristics of the component programs are given.

  16. MORPHO-STRUCTURAL ADAPTATIONS OF SOME AQUATIC CARNIVOROUS PLANT SPECIES (ALDROVANDA VESICULOSA L. AND UTRICULARIA VULGARIS L.

    STANESCU IRINA

    2007-12-01

    Full Text Available In the present work the authors emphasize a few structure particularities of two aquatic carnivorous plant species, Aldrovanda vesiculosa L. and Utricularia vulgaris L., underlining their adaptation to the aquatic medium and to the carnivory menu.

  17. Antibacterial Barbituric Acid Analogues Inspired from Natural 3-Acyltetramic Acids; Synthesis, Tautomerism and Structure and Physicochemical Property-Antibacterial Activity Relationships

    Yong-Chul Jeong

    2015-02-01

    Full Text Available The synthesis, tautomerism and antibacterial activity of novel barbiturates is reported. In particular, 3-acyl and 3-carboxamidobarbiturates exhibited antibacterial activity, against susceptible and some resistant Gram-positive strains of particular interest is that these systems possess amenable molecular weight, rotatable bonds and number of proton-donors/acceptors for drug design as well as less lipophilic character, with physicochemical properties and ionic states that are similar to current antibiotic agents for oral and injectable use. Unfortunately, the reduction of plasma protein affinity by the barbituric core is not sufficient to achieve activity in vivo. Further optimization to reduce plasma protein affinity and/or elevate antibiotic potency is therefore required, but we believe that these systems offer unusual opportunities for antibiotic drug discovery.

  18. Antibacterial barbituric acid analogues inspired from natural 3-acyltetramic acids; synthesis, tautomerism and structure and physicochemical property-antibacterial activity relationships.

    Jeong, Yong-Chul; Moloney, Mark G

    2015-01-01

    The synthesis, tautomerism and antibacterial activity of novel barbiturates is reported. In particular, 3-acyl and 3-carboxamidobarbiturates exhibited antibacterial activity, against susceptible and some resistant Gram-positive strains of particular interest is that these systems possess amenable molecular weight, rotatable bonds and number of proton-donors/acceptors for drug design as well as less lipophilic character, with physicochemical properties and ionic states that are similar to current antibiotic agents for oral and injectable use. Unfortunately, the reduction of plasma protein affinity by the barbituric core is not sufficient to achieve activity in vivo. Further optimization to reduce plasma protein affinity and/or elevate antibiotic potency is therefore required, but we believe that these systems offer unusual opportunities for antibiotic drug discovery. PMID:25710842

  19. Dip-separated structural filtering using seislet transform and adaptive empirical mode decomposition based dip filter

    Chen, Yangkang

    2016-04-01

    The seislet transform has been demonstrated to have a better compression performance for seismic data compared with other well-known sparsity promoting transforms, thus it can be used to remove random noise by simply applying a thresholding operator in the seislet domain. Since the seislet transform compresses the seismic data along the local structures, the seislet thresholding can be viewed as a simple structural filtering approach. Because of the dependence on a precise local slope estimation, the seislet transform usually suffers from low compression ratio and high reconstruction error for seismic profiles that have dip conflicts. In order to remove the limitation of seislet thresholding in dealing with conflicting-dip data, I propose a dip-separated filtering strategy. In this method, I first use an adaptive empirical mode decomposition based dip filter to separate the seismic data into several dip bands (5 or 6). Next, I apply seislet thresholding to each separated dip component to remove random noise. Then I combine all the denoised components to form the final denoised data. Compared with other dip filters, the empirical mode decomposition based dip filter is data-adaptive. One only need to specify the number of dip components to be separated. Both complicated synthetic and field data examples show superior performance of my proposed approach than the traditional alternatives. The dip-separated structural filtering is not limited to seislet thresholding, and can also be extended to all those methods that require slope information.

  20. Dip-separated structural filtering using seislet transform and adaptive empirical mode decomposition based dip filter

    Chen, Yangkang

    2016-07-01

    The seislet transform has been demonstrated to have a better compression performance for seismic data compared with other well-known sparsity promoting transforms, thus it can be used to remove random noise by simply applying a thresholding operator in the seislet domain. Since the seislet transform compresses the seismic data along the local structures, the seislet thresholding can be viewed as a simple structural filtering approach. Because of the dependence on a precise local slope estimation, the seislet transform usually suffers from low compression ratio and high reconstruction error for seismic profiles that have dip conflicts. In order to remove the limitation of seislet thresholding in dealing with conflicting-dip data, I propose a dip-separated filtering strategy. In this method, I first use an adaptive empirical mode decomposition based dip filter to separate the seismic data into several dip bands (5 or 6). Next, I apply seislet thresholding to each separated dip component to remove random noise. Then I combine all the denoised components to form the final denoised data. Compared with other dip filters, the empirical mode decomposition based dip filter is data-adaptive. One only needs to specify the number of dip components to be separated. Both complicated synthetic and field data examples show superior performance of my proposed approach than the traditional alternatives. The dip-separated structural filtering is not limited to seislet thresholding, and can also be extended to all those methods that require slope information.

  1. Evolutionary genomics reveals conserved structural determinants of signaling and adaptation in microbial chemoreceptors

    Alexander, Roger P [ORNL; Jouline, Igor B [ORNL

    2007-01-01

    As an important model for transmembrane signaling, methyl-accepting chemotaxis proteins (MCPs) have been extensively studied by using genetic, biochemical, and structural techniques. However, details of the molecular mechanism of signaling are still not well understood. The availability of genomic information for hundreds of species enables the identification of features in protein sequences that are conserved over long evolutionary distances and thus are critically important for function. We carried out a large-scale comparative genomic analysis of the MCP signaling and adaptation domain family and identified features that appear to be critical for receptor structure and function. Based on domain length and sequence conservation, we identified seven major MCP classes and three distinct structural regions within the cytoplasmic domain: signaling, methylation, and flexible bundle subdomains. The flexible bundle subdomain, not previously recognized in MCPs, is a conserved element that appears to be important for signal transduction. Remarkably, the N- and C-terminal helical arms of the cytoplasmic domain maintain symmetry in length and register despite dramatic variation, from 24 to 64 7-aa heptads in overall domain length. Loss of symmetry is observed in some MCPs, where it is concomitant with specific changes in the sensory module. Each major MCP class has a distinct pattern of predicted methylation sites that is well supported by experimental data. Our findings indicate that signaling and adaptation functions within the MCP cytoplasmic domain are tightly coupled, and that their coevolution has contributed to the significant diversity in chemotaxis mechanisms among different organisms.

  2. Structure-based analysis of high pressure adaptation of alpha-actin.

    Morita, Takami

    2003-07-25

    Deep-sea fishes occur to depths of several thousand meters, and at these abyssal depths encounter pressures that shallower living fishes cannot tolerate. Tolerance of abyssal pressures by deep-sea fish is likely to depend in part on adaptive modifications of proteins. However, the types of structural modifications to proteins that allow function at high pressure have not been discovered. To elucidate the mechanisms of protein adaptation to high pressure, we cloned the alpha-skeletal actin cDNAs from two abyssal Coryphaenoides species, C. armatus and C. yaquinae, and identified three amino acid substitutions, V54A or L67P, Q137K, and A155S, that distinguish these abyssal actins from orthologs of alpha-actin from non-abyssal Coryphaenoides. These substitutions, Q137K and A155S, prevent the dissociation reactions of ATP and Ca2+ from being influenced by high pressure. In particular, the lysine residue at position 137 results in a much smaller apparent volume change in the Ca2+ dissociation reaction. The V54A or L67P substitution reduces the volume change associated with actin polymerization and has a role in maintaining the DNase I activity of actin at high pressure. Together, these results indicate that a few amino acid substitutions in key functional positions can adaptively alter the pressure sensitivity of a protein. PMID:12740368

  3. VLT/NACO infrared adaptive optics images of small scale structures in OMC1

    Lacombe, F; Rouan, D; Clénet, Y; Lemaire, J L; Lagrange, A M; Mouillet, D; Rousset, G; Marlot, C; Feautrier, P; Gustafsson, M; Field, D; Lacombe, Francois; Gendron, Eric; Rouan, Daniel; Clenet, Yann; Lemaire, Jean-Louis; Lagrange, Anne-Marie; Mouillet, David; Rousset, Gerard; Marlot, Claude; Feautrier, Philippe; Field, David; Proxy, Bernard Servan; ccsd-00000915, ccsd

    2003-01-01

    Near-infrared observations of line emission from excited H2 and in the continuum are reported in the direction of the Orion molecular cloud OMC1, using the European Southern Observatory Very Large Telescope UT4, equipped with the NAOS adaptive optics system and the CONICA infrared array camera. Spatial resolution has been achieved at close to the diffraction limit of the telescope (0.08" - 0.12") and images show a wealth of morphological detail. Structure is not fractal but shows two preferred scale sizes of 2.4" (1100 AU) and 1.2" (540 AU), where the larger scale may be associated with star formation.

  4. Block Structured Adaptive Mesh and Time Refinement for Hybrid, Hyperbolic + N-body Systems

    Miniati, F; Miniati, Francesco; Colella, Phillip

    2006-01-01

    We present a new numerical algorithm for the solution of coupled collisional and collisionless systems, based on the block structured adaptive mesh and time refinement strategy (AMR). We describe the issues associated with the discretization of the system equations and the synchronization of the numerical solution on the hierarchy of grid levels. We implement a code based on a higher order, conservative and directionally unsplit Godunov method for hydrodynamics; a symmetric, time centered modified symplectic scheme for collisionless component; and a multilevel, multigrid relaxation algorithm for the elliptic equation coupling the two components. Numerical results that illustrate the accuracy of the code and the relative merit of various implemented schemes are also presented.

  5. Perceived Autonomy in Old Age scale: Factor structure and psychometric properties of the Polish adaptation

    Aleksandra Kroemeke

    2015-01-01

    Objectives Sense of autonomy – the possibility to choose and decide – is one of the markers of positive and active aging. The goal of this study was to examine the Polish adaptation of the Perceived Autonomy in Old Age (PAA) scale and to determine its internal structure and psychometric properties: reliability, as well as construct and discriminant validity. Methods 277 seniors (female=187; male=90), without cognitive function disorders aged 60 to 100 (M=77.4; SD=9.2) took part in t...

  6. Vibrational behavior of adaptive aircraft wing structures modelled as composite thin-walled beams

    Song, O.; Librescu, L.; Rogers, C. A.

    1992-01-01

    The vibrational behavior of cantilevered aircraft wings modeled as thin-walled beams and incorporating piezoelectric effects is studied. Based on the converse piezoelectric effect, the system of piezoelectric actuators conveniently located on the wing yield the control of its associated vertical and lateral bending eigenfrequencies. The possibility revealed by this study enabling one to increase adaptively the eigenfrequencies of thin-walled cantilevered beams could play a significant role in the control of the dynamic response and flutter of wing and rotor blade structures.

  7. An adaptive structure data acquisition system using a graphical-based programming language

    Baroth, Edmund C.; Clark, Douglas J.; Losey, Robert W.

    1992-01-01

    An example of the implementation of data fusion using a PC and a graphical programming language is discussed. A schematic of the data acquisition system and user interface panel for an adaptive structure test are presented. The computer programs (a series of icons 'wired' together) are also discussed. The way in which using graphical-based programming software to control a data acquisition system can simplify analysis of data, promote multidisciplinary interaction, and provide users a more visual key to understanding their data are shown.

  8. An Innovations-Based Noise Cancelling Technique on Inverse Kepstrum Whitening Filter and Adaptive FIR Filter in Beamforming Structure

    Jinsoo Jeong

    2011-06-01

    Full Text Available This paper presents an acoustic noise cancelling technique using an inverse kepstrum system as an innovations-based whitening application for an adaptive finite impulse response (FIR filter in beamforming structure. The inverse kepstrum method uses an innovations-whitened form from one acoustic path transfer function between a reference microphone sensor and a noise source so that the rear-end reference signal will then be a whitened sequence to a cascaded adaptive FIR filter in the beamforming structure. By using an inverse kepstrum filter as a whitening filter with the use of a delay filter, the cascaded adaptive FIR filter estimates only the numerator of the polynomial part from the ratio of overall combined transfer functions. The test results have shown that the adaptive FIR filter is more effective in beamforming structure than an adaptive noise cancelling (ANC structure in terms of signal distortion in the desired signal and noise reduction in noise with nonminimum phase components. In addition, the inverse kepstrum method shows almost the same convergence level in estimate of noise statistics with the use of a smaller amount of adaptive FIR filter weights than the kepstrum method, hence it could provide better computational simplicity in processing. Furthermore, the rear-end inverse kepstrum method in beamforming structure has shown less signal distortion in the desired signal than the front-end kepstrum method and the front-end inverse kepstrum method in beamforming structure.

  9. Physicochemical Insights on Alkylcarbonate-Alkanol Solutions.

    Alcalde, Rafael; Atilhan, Mert; Trenzado, José Luis; Aparicio, Santiago

    2016-06-01

    Macroscopic properties and structuring at the molecular level of dialkylcarbonate + 1-alkanol mixed fluids have been studied as a function of alkyl chain lengths in 1-alkanol and dialkylcarbonate, mixture composition, and temperature. A combined experimental and computational approach was considered for studying the relationships between the nanoscopic structure of the mixed fluids; nature, extension, and organization of hydrogen bonding; and physicochemical properties. Thermodynamics characterization, using excess and mixing properties, are related with the strength and characteristics of intermolecular forces. Classic molecular dynamics simulations and quantum chemistry calculations provide a detailed picture of the mixed fluids' structuring and dynamic behavior. PMID:27171831

  10. 1H and 13C NMR spectra, structure and physicochemical features of phenyl acridine-9-carboxylates and 10-methyl-9-(phenoxycarbonyl)acridinium trifluoromethanesulphonates--alkyl substituted in the phenyl fragment.

    Krzymiński, K; Malecha, P; Zadykowicz, B; Wróblewska, A; Błażejowski, J

    2011-01-01

    The 1H and 13C NMR spectra of twelve phenyl acridine-9-carboxylates--alkyl-substituted in the phenyl fragment--and their 10-methyl-9-(phenoxycarbonyl)acridinium salts dissolved in CD3CN, CD3OD, CDCl3 and DMSO-d6 were recorded in order to examine the influence of the structure of these compounds and the properties of the solvents on chemical shifts and 1H-(1)H coupling constants. Experimental data were compared with 1H and 13C chemical shifts predicted at the GIAO/DFT level of theory for DFT(B3LYP)/6-31G** optimised geometries of molecules, as well as with values of 1H chemical shifts and 1H-(1)H coupling constants, estimated using ACD/HNMR database software to ensure that the assignment was correct. To investigate the relations between chemical shifts and selected structural or physicochemical characteristics of the target compounds, the values of several of these parameters were determined at the DFT or HF levels of theory. The HOMO and LUMO energies obtained at the HF level yielded the ionisation potentials and electron affinities of molecules. The DFT method provided atomic partial charges, dipole moments, LCAO coefficients of pz LUMO of selected C atoms, and angles reflecting characteristic structural features of the compounds. It was found that the experimentally determined 1H and 13C chemical shifts of certain atoms relate to the predicted dipole moments, the angles between the acridine and phenyl moieties, and the LCAO coefficients of the pz LUMO of the C atoms believed to participate in the initial step of the oxidation of the target compounds. The spectral and physicochemical characteristics of the target compounds were investigated in the context of their chemiluminogenic ability. PMID:21134782

  11. The periparturient period is associated with structural and transcriptomic adaptations of rumen papillae in dairy cattle.

    Steele, M A; Schiestel, C; AlZahal, O; Dionissopoulos, L; Laarman, A H; Matthews, J C; McBride, B W

    2015-04-01

    The structural and functional adaption of the rumen epithelium during the transition period is largely undescribed. To characterize the adaptation of the rumen epithelium during transition, multiparous dairy cattle (n=12) fitted with rumen fistulas and fed a low-energy dry cow diet (1.37 Mcal/kg, net energy for lactation) were transitioned abruptly to a high-energy lactating cow diet (1.68 Mcal/kg, net energy for lactation) immediately after parturition. Rumen papillae were biopsied at -3, +1, and +6 wk relative to calving. The histology of morphology of the rumen papillae was evaluated under the light microscope and electron microscope, and mRNA profiling was performed using an Affymetrix GeneChip Bovine Gene 1.0 ST Array (Affymetrix, Santa Clara, CA). Data preprocessing was conducted using the robust multi-array average method, and detection of significant genes was conducted using ANOVA. Also, the Benjamini-Hochberg false discovery rate of 0.1 was applied. Microscopic examination of rumen papillae revealed an increase in epithelial desquamation during early lactation as sloughing scores increased from 1.7 ± 0.2 at -3 wk to 4.1 ± 0.3 and 3.4 ± 0.2 at +1 and + 6 wk, respectively. A total of 1,011 (-3 vs. +1 wk) and 729 (-3 vs. +6 wk) differentially expressed genes were identified (false discovery rate of 0.10, Ptransition period in dairy cattle. In conclusion, the experimental data support the hypothesis that rumen papillae adapt in early lactation by altering their gene expression patterns and, thus, their epithelial structure. PMID:25682143

  12. The network structure of adaptive governance - A single case study of a fish management area

    Annica Charlotte Sandström

    2009-09-01

    Full Text Available The challenge of establishing adaptive management systems is a widely discussed topic in the literature on natural resource management. Adaptive management essentially focuses on achieving a governance process that is both sensitive to and has the capacity to continuously react to changes within the ecosystem being managed. The adoption of a network approach that perceives governance structures as social networks, searching for the kind of network features promoting this important feature, has been requested by researchers in the field. In particular, the possibilities associated with the application of a formal network approach, using the tools and concepts of social network analysis (SNA, have been identified as having significant potential for advancing this branch of research. This paper aims to address the relation between network structure and adaptability using an empirical approach. With the point of departure in a previously generated theoretical framework as well as related hypotheses, this paper presents a case study of a governance process within a fish management area in Sweden. The hypotheses state that, although higher levels of network density and centralisation promote the rule-forming process, the level of network heterogeneity is important for the existence and spread of ecological knowledge among the actors involved. According to the empirical results, restricted by the single-case study design, this assumption is still a well-working hypothesis. However, in order to advance our knowledge concerning these issues and test the validity of the hypotheses, more empirical work using a similar approach in multiple case study designs is needed.

  13. Adaptive neural network/expert system that learns fault diagnosis for different structures

    Simon, Solomon H.

    1992-08-01

    Corporations need better real-time monitoring and control systems to improve productivity by watching quality and increasing production flexibility. The innovative technology to achieve this goal is evolving in the form artificial intelligence and neural networks applied to sensor processing, fusion, and interpretation. By using these advanced Al techniques, we can leverage existing systems and add value to conventional techniques. Neural networks and knowledge-based expert systems can be combined into intelligent sensor systems which provide real-time monitoring, control, evaluation, and fault diagnosis for production systems. Neural network-based intelligent sensor systems are more reliable because they can provide continuous, non-destructive monitoring and inspection. Use of neural networks can result in sensor fusion and the ability to model highly, non-linear systems. Improved models can provide a foundation for more accurate performance parameters and predictions. We discuss a research software/hardware prototype which integrates neural networks, expert systems, and sensor technologies and which can adapt across a variety of structures to perform fault diagnosis. The flexibility and adaptability of the prototype in learning two structures is presented. Potential applications are discussed.

  14. Towards Global Jihadism: Al-Qaeda's Strategic, Ideological and Structural Adaptations since 9/11

    Bill Braniff

    2011-05-01

    Full Text Available In recent years, Al-Qaeda has suffered a number of setbacks, but has also successfully spawned an expansionist global jihadist movement that will survive the death of Osama bin Laden. This article describes how the multifaceted threat posed by global jihadism has evolved over the last decade. It first recounts some of the more salient examples of Al-Qaeda’s post-9/11 strategic, ideological, and structural adaptations, and then offers a balance sheet of Al-Qaeda’s contemporary strengths and weaknesses. Al-Qaeda continues to enable the violence of others, orient that violence towards the United States and its allies in a distributed game of attrition warfare, and foster a dichotomous “us versus them” narrative between the Muslim world and the rest of the international community. Despite this overarching consistency, Al-Qaeda shepherds a different phenomenon than it did ten years ago. The aggregation of the movement’s strategic, ideological, and structural adaptations has fundamentally changed the nature of the jihadist threat to the West. This evolved threat is not inherently more dangerous, as counterterrorism efforts today focus on and disrupt capability earlier and more consistently than prior to September 2001. This multifaceted global jihad will, however, continue to produce greater numbers of attacks in more locations, from a more diverse cadre of individuals spanning a wider ideological spectrum.   

  15. [Night sleep structural alteration as a function of individual strategy of adapting to 520-isolation].

    Zavalko, I M; Boritko, Ya S; Kovrov, G V; Vinokhodova, A G; Chekalina, A I; Smoleevsky, A E

    2014-01-01

    Purpose of the work was to establish a relationship between trends in sleep alteration and individual adaptation to the stress-factors in the 520-day isolation study. Psychological evaluations using a battery of motivation tests and L. Sobchik's modification of the Luscher personality test, and Mirror coordinograph enabled to differentiate groups reacting to the stress on the pattern of "control" (G-1) or "search" (G-2) manifested in individual styles of behavior and operator's activity. The 2 groups showed different dynamics of the night sleep structure. Difficulties with falling asleep in G-1 arose on the eve of "landing onto Mars" and end of the experiment, whereas in G-2 they were evident prior to the end only. Besides, the micro- and segmental sleep structures were more stable in G-1 suggesting the integrity of somnogenic mechanisms despite difficult sleep initiation. PMID:25033611

  16. Designing of Elastoplastic Adaptive Truss Structures with the Use of Particle Swarm Optimization

    Jacek Szklarski

    2015-01-01

    Full Text Available In the paper we demonstrate how Particle Swarm Optimization (PSO can be employed to solve the Adaptive Impact Absorption (AIA problem. We consider a truss structure which is subjected to impact loads. Stiff bars can be replaced by elastoplastic fuses which control theirs dynamical response. The point of optimization is to maximize or minimize a given objective function by redesigning the structure. This is realized by redistributing the initial mass, finding proper fuse localizations and adjusting, in real-time, the elastoplastic limits. Comparing to the previous results, we show that PSO is capable of achieving results at least as good as gradient-based optimization, having at the same time much larger flexibility regarding the definition of the objective function. This gives significantly broader field of potential applications. In particular, we present how PSO can be used to solve the simultaneous optimization problem: mass redistribution and fuse positioning for a set of expected, various impacts.

  17. Structural adaptive and optimal speckle filtering in multilook full polarimetric SAR images

    Sun Nan; Zhang Bingchen; Wang Yanfei

    2007-01-01

    A novel approach is proposed for speckle reduction in multilook full polarimetric SAR images.In contrast to others, this approach adopts an enhanced structure detection method to estimate the parameters of the polarimetric covariance matrix for the multilook polarimetric whitening filtering (MPWF) algorithm and thus a structural adaptive and optimal speckle filter is developed.To evaluate the present approach, NASA SIR-C/X-SAR, L band, four-look processed polarimetric SAR data of the Tian-Mountain Forest is used for simulation.Experimental results demonstrate the effectiveness of this novel filtering algorithm in case of both speckle reduction and preservation of texture information.Comparisons with other methods are also made.

  18. A model of physical factors in the structural adaptation of microvascular networks in normotension and hypertension

    Jacobsen, Jens Christian Brings; Gustafsson, Finn; Holstein-Rathlou, N.-H.

    2003-01-01

    a persistent change in luminal diameter. On this basis we hypothesize that wall influencing substances released from the endothelium in response to shear stress have a certain optimal level in the vascular wall. Deviation from this level will cause vascular remodeling, i.e. a structural change in luminal...... diameter, until equilibrium is restored. The model explains several of the key features observed experimentally in the microcirculation in normotension and hypertension. Most importantly, it suggests a scenario where overall network structure and network hemodynamics depend on adaptation to local...... hemodynamic stimuli in the individual vessel. Simulated results show emanating microvascular networks with properties similar to those observed in vivo. The model points to an altered endothelial function as a key factor in the development of vascular changes characteristic of hypertension....

  19. Structural Characteristics and Eco-adaptability of Heteromorphic Leaves of Populus euphratica

    Li Zhao-xia; Zheng Cai-xia

    2005-01-01

    The microstructural and ultrastructural traits of three kinds of typical leaves of Populus euphratica Olive, including lanceolate, broad-ovate and dentate broad-ovate leaves, were studied by using electron microscope and optical microscope. The results showed that with the leaves changing from lanceolate shape to dentate broad-ovate shape, their structure obviously tended to be xeromorph: developed palisade tissue, undeveloped spongy tissue, thick cutin layer and sunken stomas. The amount of mitochondria tended to be increased, and the shape of chloroplasts varied from regular spindle to irregular rotundity or oval. The leaves were covered with wax without cilium, and the stomas on the upper and lower epidermis of the leaves opened unevenly. The stomas on the lower epidermis were deeper than those on the upper epidermis under the scanning electron microscope. The results implied that the structural characteristics of the diversiform-leaves of P. euphratica are related to its eco-adaptability.

  20. Adaptive cellular structures and devices with internal features for enhanced structural performance

    Pontecorvo, Michael Eugene

    This dissertation aims to develop a family of cellular and repeatable devices that exhibit a variety of force-displacement behaviors. It is envisioned that these cellular structures might be used either as stand-alone elements, or combined and repeated to create multiple types of structures (i.e. buildings, ship hulls, vehicle subfloors, etc.) with the ability to passively or actively perform multiple functions (harmonic energy dissipation, impact mitigation, modulus change) over a range of loading types, amplitudes, and frequencies. To accomplish this goal, this work combines repeatable structural frameworks, such as that provided by a hexagonal cellular structure, with internal structural elements such as springs, viscous dampers, buckling plates, bi-stable von Mises trusses (VMTs), and pneumatic artificial muscles (PAMs). The repeatable framework serves to position damping and load carrying elements throughout the structure, and the configuration of the internal elements allow each cell to be tuned to exhibit a desired force-displacement response. Therefore, gradient structures or structures with variable load paths can be created for an optimal global response to a range of loads. This dissertation focuses on the development of cellular structures for three functions: combined load-carrying capability with harmonic energy dissipation, impact mitigation, and cell modulus variation. One or more conceptual designs are presented for devices that can perform each of these functions, and both experimental measurements and simulations are used to gain a fundamental understanding of each device. Chapter 2 begins with a presentation of a VMT model that is the basis for many of the elements. The equations of motion for the VMT are derived and the static and dynamic behavior of the VMT are discussed in detail. Next, two metrics for the energy dissipation of the VMT - hysteresis loop area and loss factor - are presented. The responses of the VMT to harmonic displacement

  1. Experimental Study of an Adaptive Sequential Nonlinear LSE with Unknown Inputs for Structural Damage Tracking

    Tengfei Mu

    2014-01-01

    Full Text Available An improved adaptive sequential nonlinear LSE with unknown inputs (ASNLSE-UI approach was proposed to real-time-track the structural damage when it occurs for structural safety and management after emergency event. Experimental studies are presented to verify the capability of the improved ASNLSE-UI approach. A series of tests using a small-scale 3-story base-isolated building have been performed. White noise and earthquake excitations, applied to the base of the model, have been used. To simulate structural damages during the test, an innovative device is designed and manufactured to reduce the stiffness of some stories. With the measured response data of different damage scenarios, the improved ASNLSE-UI approach is used to track the variation of structural physical parameters. Besides, the unknown inputs are simultaneously identified. Experimental results demonstrate that the improved ASNLSE-UI approach is capable of tracking the variation of stiffness parameters leading to the detection of structural damages.

  2. PACS—Realization of an adaptive concept using pressure actuated cellular structures

    A biologically inspired concept is investigated which can be utilized to develop energy efficient, lightweight and applicational flexible adaptive structures. Building a real life morphing unit is an ambitious task as the numerous works in the particular field show. Summarizing fundamental demands and barriers regarding shape changing structures, the basic challenges of designing morphing structures are listed. The concept of Pressure Actuated Cellular Structures (PACS) is arranged within the recent morphing activities and it is shown that it complies with the underlying demands. Systematically divided into energy-related and structural subcomponents the working principle is illuminated and relationships between basic design parameters are expressed. The analytical background describing the physical mechanisms of PACS is presented in concentrated manner. This work focuses on the procedure of dimensioning, realizing and experimental testing of a single cell and a single row cantilever made of PACS. The experimental outcomes as well as the results from the FEM computations are used for evaluating the analytical methods. The functionality of the basic principle is thus validated and open issues are determined pointing the way ahead. (paper)

  3. Physicochemical properties of quinoa starch.

    Li, Guantian; Wang, Sunan; Zhu, Fan

    2016-02-10

    Physicochemical properties of quinoa starches isolated from 26 commercial samples from a wide range of collection were studied. Swelling power (SP), water solubility index (WSI), amylose leaching (AML), enzyme susceptibility, pasting, thermal and textural properties were analyzed. Apparent amylose contents (AAM) ranged from 7.7 to 25.7%. Great variations in the diverse physicochemical properties were observed. Correlation analysis showed that AAM was the most significant factor related to AML, WSI, and pasting parameters. Correlations among diverse physicochemical parameters were analyzed. Principal component analysis using twenty three variables were used to visualize the difference among samples. Six principal components were extracted which could explain 88.8% of the total difference. The wide variations in physicochemical properties could contribute to innovative utilization of quinoa starch for food and non-food applications. PMID:26686137

  4. Structural analysis of inhibition of E. coli methionine aminopeptidase: implication of loop adaptability in selective inhibition of bacterial enzymes

    Ma, Ze-qiang; Xie, Sheng-xue; Huang, Qing-Qing; Nan, Fa-jun; Hurley, Thomas D.; Ye, Qi-Zhuang

    2007-01-01

    Background Methionine aminopeptidase is a potential target of future antibacterial and anticancer drugs. Structural analysis of complexes of the enzyme with its inhibitors provides valuable information for structure-based drug design efforts. Results Five new X-ray structures of such enzyme-inhibitor complexes were obtained. Analysis of these and other three similar structures reveals the adaptability of a surface-exposed loop bearing Y62, H63, G64 and Y65 (the YHGY loop) that is an integral ...

  5. Adaptive AFM scan speed control for high aspect ratio fast structure tracking

    Ahmad, Ahmad; Schuh, Andreas; Rangelow, Ivo W. [Department of Microelectronic and Nanoelectronic Systems, Faculty of Electrical Engineering and Information Technology Ilmenau University of Technology, Gustav-Kirchhoffstr. 1, 98684 Ilmenau (Germany)

    2014-10-15

    Improved imaging rates in Atomic Force Microscopes (AFM) are of high interest for disciplines such as life sciences and failure analysis of semiconductor wafers, where the sample topology shows high aspect ratios. Also, fast imaging is necessary to cover a large surface under investigation in reasonable times. Since AFMs are composed of mechanical components, they are associated with comparably low resonance frequencies that undermine the effort to increase the acquisition rates. In particular, high and steep structures are difficult to follow, which causes the cantilever to temporarily loose contact to or crash into the sample. Here, we report on a novel approach that does not affect the scanner dynamics, but adapts the lateral scanning speed of the scanner. The controller monitors the control error signal and, only when necessary, decreases the scan speed to allow the z-piezo more time to react to changes in the sample's topography. In this case, the overall imaging rate can be significantly increased, because a general scan speed trade-off decision is not needed and smooth areas are scanned fast. In contrast to methods trying to increase the z-piezo bandwidth, our method is a comparably simple approach that can be easily adapted to standard systems.

  6. Structural and functional robustness of the adaptive-sorting signaling network

    Pang, Ning-Ning

    2016-06-01

    A major task of study on ligand discrimination by T cells is the construction of a mechanistic model to account for threshold setting in response to variant ligands interacting with the same T-cell receptors. Recently, Lalanne and Francois in a seminal paper (2013 Phys. Rev. Lett. 110 218102) have addressed this question by constructing minimal core circuits such that the biological outputs can satisfy the essential properties of early T-cell activation. To make this core set of network topology a valuable tool for synthetic biologists to robustly engineer biological circuits, we are motivated to ask a general question: is adaptive response encoded by the proposed circuit topology structurally stable, regardless of the values of the kinetic parameters? This has particularly relevant effects for the network reliability, since failures in ligand discrimination result in either infection or autoimmune diseases. To the best of our knowledge, a rigorous and complete mathematical proof of this issue is still lacking in the literature. In this paper, by giving a rigorous mathematical proof, we have shown that this regulatory circuitry is appropriately designed and the existence, uniqueness, and globally asymptotic attractiveness of the steady state are preserved. Moreover, we further generalize the adaptive sorting module and undertake an extensive analysis on the trade-off between antagonism and sensitivity of T-cell ligand discrimination in various cellular conditions. Notably, the optimal phosphorylation step in which to place the regulatory motif is analytically obtained and numerically confirmed. Finally, relevant experimental facts and biological implications are discussed.

  7. Structured Clinical Interview for DSM-IV (SCID Persian Translation and Cultural Adaptation:

    Mitra Hakim Shooshtari

    2007-05-01

    Full Text Available "nObjective: To translate the Structured Clinical Interview for DSM-IV axisI "ndisorders (SCID-I into Persian (Farsi and to adapt this instrument for the "nIranian culture. "nMethod: The SCID was translated into Persian using an elaborate procedure to "nachieve a satisfactory cross-cultural equivalent. This included forward "ntranslation by bilingual (English/Persian translators, discussion and revision of "nthe translation in an expert panel of bilingual mental health professionals, pilot "nassessment on a small sample of Persian-speaking patients, back-translation "ninto English and comparison with the original SCID. In addition, "nunderstandability and acceptability of the translated items were assessed in 299 "npatients in three psychiatric hospitals in Tehran, Iran. "nResults: Some adaptations were made to bring about cross-cultural "ncomparability, especially with regard to conceptual differences which led to "ndifficulties in transferring some psychiatric concepts from English to Persian. "nThe SCID questions were generally understandable and acceptable for the "nIranian patients. "nConclusion: The SCID was translated into Persian in a multi-stage process to "nensure a satisfactory cross-cultural equivalent.

  8. Electronic Structure Calculations and Adaptation Scheme in Multi-core Computing Environments

    Seshagiri, Lakshminarasimhan; Sosonkina, Masha; Zhang, Zhao

    2009-05-20

    Multi-core processing environments have become the norm in the generic computing environment and are being considered for adding an extra dimension to the execution of any application. The T2 Niagara processor is a very unique environment where it consists of eight cores having a capability of running eight threads simultaneously in each of the cores. Applications like General Atomic and Molecular Electronic Structure (GAMESS), used for ab-initio molecular quantum chemistry calculations, can be good indicators of the performance of such machines and would be a guideline for both hardware designers and application programmers. In this paper we try to benchmark the GAMESS performance on a T2 Niagara processor for a couple of molecules. We also show the suitability of using a middleware based adaptation algorithm on GAMESS on such a multi-core environment.

  9. Block structured adaptive mesh and time refinement for hybrid, hyperbolic + N-body systems

    Miniati, Francesco; Colella, Phillip

    2007-11-01

    We present a new numerical algorithm for the solution of coupled collisional and collisionless systems, based on the block structured adaptive mesh and time refinement strategy (AMR). We describe the issues associated with the discretization of the system equations and the synchronization of the numerical solution on the hierarchy of grid levels. We implement a code based on a higher order, conservative and directionally unsplit Godunov’s method for hydrodynamics; a symmetric, time centered modified symplectic scheme for collisionless component; and a multilevel, multigrid relaxation algorithm for the elliptic equation coupling the two components. Numerical results that illustrate the accuracy of the code and the relative merit of various implemented schemes are also presented.

  10. CALCULATION OF ADAPTIVE MULTILAYERED THIN-WALLED STRUCTURES SUBJECTED TO TEMPERATURE LOADING

    S. V. Plotnikova

    2011-04-01

    Full Text Available Problem statement. A number of difficult problems centre around the application of 3D isoparametric finite elements to compensate the strains and to control the shape of thin-walled structures. One of these problems is decreasing efficiency of the finite element code.Results. This paper presents a new 3D geometrically exact four-node solid-shell element based on the 7-parameter theory of thermoelectroelastic shells, which gives the possibility to use 3D constitutive equations of thermopiezoelectricity. As unknown functions, six tangential and transverse displacements of outer surfaces and the transverse displacement of the middle surface are chosen.Conclusions. Analytical integration used for deriving a stiffness matrix, as well as the fact that displacement vectors of outer and middle surfaces are represented in a local basis related to the reference shell surface permit one to increase the performance of a finite element code and to utilize it efficiently into controllers of adaptive thin-walled structures with segmented piezoceramic patches. Numerical examples are presented to substantiate the possibility of controlling the temperature strains in thin-walled composite structures by employing the converse piezoelectric effect.