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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. 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...

  3. 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.

  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; 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.

  4. 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.

  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. 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

  7. 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

  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. 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...

  11. 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...

  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. 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

  6. 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.

  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. 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.

  16. 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.

  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. 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

  20. 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

  1. 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.

  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. 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

  6. 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

  7. 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

  8. 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

  9. 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.

  10. 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.

  11. 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

  12. 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.

  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. 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

  8. 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

  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. 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.

  12. 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.

  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. 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

  5. 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.

  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. 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.

  4. 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

  5. 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.

  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. 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...

  15. 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.,

  16. 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…

  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. 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.

  20. 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...

  1. 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...

  2. 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.

  3. 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...

  4. [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

  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. 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).

  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. 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....

  14. 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...

  15. 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

  16. 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...

  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. 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...

  19. 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 ...

  20. 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

  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. 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.

  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 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.

  7. 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.

  8. 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.

  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

    2016-07-01

    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.

  20. 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.

  1. 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.

  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. 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.

  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. 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...

  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 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.

  12. 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

  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. 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

  16. 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.

  17. [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

  18. 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.

  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. 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....

  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. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. Subfamily-specific adaptations in the structures of two penicillin-binding proteins from Mycobacterium tuberculosis.

    Daniil M Prigozhin

    Full Text Available Beta-lactam antibiotics target penicillin-binding proteins including several enzyme classes essential for bacterial cell-wall homeostasis. To better understand the functional and inhibitor-binding specificities of penicillin-binding proteins from the pathogen, Mycobacterium tuberculosis, we carried out structural and phylogenetic analysis of two predicted D,D-carboxypeptidases, Rv2911 and Rv3330. Optimization of Rv2911 for crystallization using directed evolution and the GFP folding reporter method yielded a soluble quadruple mutant. Structures of optimized Rv2911 bound to phenylmethylsulfonyl fluoride and Rv3330 bound to meropenem show that, in contrast to the nonspecific inhibitor, meropenem forms an extended interaction with the enzyme along a conserved surface. Phylogenetic analysis shows that Rv2911 and Rv3330 belong to different clades that emerged in Actinobacteria and are not represented in model organisms such as Escherichia coli and Bacillus subtilis. Clade-specific adaptations allow these enzymes to fulfill distinct physiological roles despite strict conservation of core catalytic residues. The characteristic differences include potential protein-protein interaction surfaces and specificity-determining residues surrounding the catalytic site. Overall, these structural insights lay the groundwork to develop improved beta-lactam therapeutics for tuberculosis.

  11. 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.

  12. Structural adaptation of extreme halophilic proteins through decrease of conserved hydrophobic contact surface

    Siglioccolo Alessandro

    2011-12-01

    Full Text Available Abstract Background Halophiles are extremophilic microorganisms growing optimally at high salt concentrations. There are two strategies used by halophiles to maintain proper osmotic pressure in their cytoplasm: accumulation of molar concentrations of potassium and chloride with extensive adaptation of the intracellular macromolecules ("salt-in" strategy or biosynthesis and/or accumulation of organic osmotic solutes ("osmolyte" strategy. Our work was aimed at contributing to the understanding of the shared molecular mechanisms of protein haloadaptation through a detailed and systematic comparison of a sample of several three-dimensional structures of halophilic and non-halophilic proteins. Structural differences observed between the "salt-in" and the mesophilic homologous proteins were contrasted to those observed between the "osmolyte" and mesophilic pairs. Results The results suggest that haloadaptation strategy in the presence of molar salt concentration, but not of osmolytes, necessitates a weakening of the hydrophobic interactions, in particular at the level of conserved hydrophobic contacts. Weakening of these interactions counterbalances their strengthening by the presence of salts in solution and may help the structure preventing aggregation and/or loss of function in hypersaline environments. Conclusions Considering the significant increase of biotechnology applications of halophiles, the understanding of halophilicity can provide the theoretical basis for the engineering of proteins of great interest because stable at concentrations of salts that cause the denaturation or aggregation of the majority of macromolecules.

  13. Structural Basis for Conserved Regulation and Adaptation of the Signal Recognition Particle Targeting Complex.

    Wild, Klemens; Bange, Gert; Motiejunas, Domantas; Kribelbauer, Judith; Hendricks, Astrid; Segnitz, Bernd; Wade, Rebecca C; Sinning, Irmgard

    2016-07-17

    The signal recognition particle (SRP) is a ribonucleoprotein complex with a key role in targeting and insertion of membrane proteins. The two SRP GTPases, SRP54 (Ffh in bacteria) and FtsY (SRα in eukaryotes), form the core of the targeting complex (TC) regulating the SRP cycle. The architecture of the TC and its stimulation by RNA has been described for the bacterial SRP system while this information is lacking for other domains of life. Here, we present the crystal structures of the GTPase heterodimers of archaeal (Sulfolobus solfataricus), eukaryotic (Homo sapiens), and chloroplast (Arabidopsis thaliana) SRP systems. The comprehensive structural comparison combined with Brownian dynamics simulations of TC formation allows for the description of the general blueprint and of specific adaptations of the quasi-symmetric heterodimer. Our work defines conserved external nucleotide-binding sites for SRP GTPase activation by RNA. Structural analyses of the GDP-bound, post-hydrolysis states reveal a conserved, magnesium-sensitive switch within the I-box. Overall, we provide a general model for SRP cycle regulation by RNA. PMID:27241309

  14. Adaptive Methods within a Sequential Bayesian Approach for Structural Health Monitoring

    Huff, Daniel W.

    Structural integrity is an important characteristic of performance for critical components used in applications such as aeronautics, materials, construction and transportation. When appraising the structural integrity of these components, evaluation methods must be accurate. In addition to possessing capability to perform damage detection, the ability to monitor the level of damage over time can provide extremely useful information in assessing the operational worthiness of a structure and in determining whether the structure should be repaired or removed from service. In this work, a sequential Bayesian approach with active sensing is employed for monitoring crack growth within fatigue-loaded materials. The monitoring approach is based on predicting crack damage state dynamics and modeling crack length observations. Since fatigue loading of a structural component can change while in service, an interacting multiple model technique is employed to estimate probabilities of different loading modes and incorporate this information in the crack length estimation problem. For the observation model, features are obtained from regions of high signal energy in the time-frequency plane and modeled for each crack length damage condition. Although this observation model approach exhibits high classification accuracy, the resolution characteristics can change depending upon the extent of the damage. Therefore, several different transmission waveforms and receiver sensors are considered to create multiple modes for making observations of crack damage. Resolution characteristics of the different observation modes are assessed using a predicted mean squared error criterion and observations are obtained using the predicted, optimal observation modes based on these characteristics. Calculation of the predicted mean square error metric can be computationally intensive, especially if performed in real time, and an approximation method is proposed. With this approach, the real time

  15. Microgeographical population structure and adaptation in Atlantic cod Gadus morhua: spatio-temporal insights from gene-associated DNA markers

    Poulsen, Nina Aagaard; Hemmer-Hansen, Jakob; Loeschcke, V.; Carvalho, G.R.; Eg Nielsen, Einar

    2011-01-01

    populations, indicating long-term temporal adaptive stability driven by strong local selection. In an environmentally dynamic area, on the other hand, patterns of genetic structuring were more variable. Overall, our results not only suggest separation of populations under both evolutionary and ecological......Recent technical advances have stimulated studies on spatial scales of adaptive genetic variation in marine fishes. However, very few studies have combined spatial and temporal sampling to investigate adaptive genetic structuring at local and microgeographical scales, i.e. scales at which neutral...... stability, we included long- and short-term (i.e. from 24 to 38 and from 8 to 11 yr, ­respectively) temporally replicated samples from a subset of populations. As expected, we found very low levels of neutral genetic population structure (FST = 0.003). Three specific loci, however, showed highly elevated...

  16. From epidemics to information propagation: Striking differences in structurally similar adaptive network models

    Trajanovski, S.; Guo, D.; Van Mieghem, P.F.A.

    2015-01-01

    The continuous-time adaptive susceptible-infected-susceptible (ASIS) epidemic model and the adaptive information diffusion (AID) model are two adaptive spreading processes on networks, in which a link in the network changes depending on the infectious state of its end nodes, but in opposite ways: (i

  17. Structure identification of an uncertain network coupled with complex-variable chaotic systems via adaptive impulsive control

    In this paper, structure identification of an uncertain network coupled with complex-variable chaotic systems is investigated. Both the topological structure and the system parameters can be unknown and need to be identified. Based on impulsive stability theory and the Lyapunov function method, an impulsive control scheme combined with an adaptive strategy is adopted to design effective and universal network estimators. The restriction on the impulsive interval is relaxed by adopting an adaptive strategy. Further, the proposed method can monitor the online switching topology effectively. Several numerical simulations are provided to illustrate the effectiveness of the theoretical results. (general)

  18. Structure transformations of endocrine system organs during adaptation to increased radioactivity

    Ermakova, O.V. [Institute of Biology, Komi Scientific Centre, Ural Division of Russian Academy of Sciences, Syktyvkar (Russian Federation)

    2004-07-01

    It is well known that during ecological monitoring of contaminated territories registration of early abnormalities in an organism is hampered by man-caused influence of habitat. Under these circumstances study of both structural and functional changes in organs and tissues of rodents inhabiting radioactive contaminated territories is of great importance. Study of structural features of endocrine glands, hormones of which trigger the process of active adaptive changes in an organism, is very important in radioecological surveys. Basing on long-term study of voles we have determined that long-term living by rodents on the territories characterized by increased natural and artificial radioactivity (radium contaminated fields in the Komi Republic and 30-km zone of Chernobyl APS) substantially influences morpho-functional state of endocrine system organs, causing quantitative and qualitative changes. It is demonstrated that population processes modify biological consequences of small doze chronic ionizing radiation in habitat. We noticed the following: high heterogeneity of histological changes of thyroid gland and adrenal gland as a response to radioactive habitat contamination; disorder of interconnection among different links of endocrine system; dependence of radiation effects on gender, age, degree and character of radiation contamination of a habitat as well as duration of radioactive influence. We have got data on morphological characteristics of thyroid gland and adrenal gland during different phases of population amount of this kind of rodents. It was discovered that effectiveness of radiation influence is not the same during different periods of population cycle. Presence of voles on the territories characterized by increased radioactivity causes chronic tension of adrenal cortex (increasing of the organ mass, enlarging of thickness of zona fasciculata and zona reticularis). Destructive-necrotic processes combine with manifestation of reparative regeneration

  19. Structure transformations of endocrine system organs during adaptation to increased radioactivity

    It is well known that during ecological monitoring of contaminated territories registration of early abnormalities in an organism is hampered by man-caused influence of habitat. Under these circumstances study of both structural and functional changes in organs and tissues of rodents inhabiting radioactive contaminated territories is of great importance. Study of structural features of endocrine glands, hormones of which trigger the process of active adaptive changes in an organism, is very important in radioecological surveys. Basing on long-term study of voles we have determined that long-term living by rodents on the territories characterized by increased natural and artificial radioactivity (radium contaminated fields in the Komi Republic and 30-km zone of Chernobyl APS) substantially influences morpho-functional state of endocrine system organs, causing quantitative and qualitative changes. It is demonstrated that population processes modify biological consequences of small doze chronic ionizing radiation in habitat. We noticed the following: high heterogeneity of histological changes of thyroid gland and adrenal gland as a response to radioactive habitat contamination; disorder of interconnection among different links of endocrine system; dependence of radiation effects on gender, age, degree and character of radiation contamination of a habitat as well as duration of radioactive influence. We have got data on morphological characteristics of thyroid gland and adrenal gland during different phases of population amount of this kind of rodents. It was discovered that effectiveness of radiation influence is not the same during different periods of population cycle. Presence of voles on the territories characterized by increased radioactivity causes chronic tension of adrenal cortex (increasing of the organ mass, enlarging of thickness of zona fasciculata and zona reticularis). Destructive-necrotic processes combine with manifestation of reparative regeneration

  20. Local adaptation of a bacterium is as important as its presence in structuring a natural microbial community.

    Gómez, Pedro; Paterson, Steve; De Meester, Luc; Liu, Xuan; Lenzi, Luca; Sharma, M D; McElroy, Kerensa; Buckling, Angus

    2016-01-01

    Local adaptation of a species can affect community composition, yet the importance of local adaptation compared with species presence per se is unknown. Here we determine how a compost bacterial community exposed to elevated temperature changes over 2 months as a result of the presence of a focal bacterium, Pseudomonas fluorescens SBW25, that had been pre-adapted or not to the compost for 48 days. The effect of local adaptation on community composition is as great as the effect of species presence per se, with these results robust to the presence of an additional strong selection pressure: an SBW25-specific virus. These findings suggest that evolution occurring over ecological time scales can be a key driver of the structure of natural microbial communities, particularly in situations where some species have an evolutionary head start following large perturbations, such as exposure to antibiotics or crop planting and harvesting. PMID:27501868

  1. Nonlocal sparse model with adaptive structural clustering for feature extraction of aero-engine bearings

    Zhang, Han; Chen, Xuefeng; Du, Zhaohui; Li, Xiang; Yan, Ruqiang

    2016-04-01

    Fault information of aero-engine bearings presents two particular phenomena, i.e., waveform distortion and impulsive feature frequency band dispersion, which leads to a challenging problem for current techniques of bearing fault diagnosis. Moreover, although many progresses of sparse representation theory have been made in feature extraction of fault information, the theory also confronts inevitable performance degradation due to the fact that relatively weak fault information has not sufficiently prominent and sparse representations. Therefore, a novel nonlocal sparse model (coined NLSM) and its algorithm framework has been proposed in this paper, which goes beyond simple sparsity by introducing more intrinsic structures of feature information. This work adequately exploits the underlying prior information that feature information exhibits nonlocal self-similarity through clustering similar signal fragments and stacking them together into groups. Within this framework, the prior information is transformed into a regularization term and a sparse optimization problem, which could be solved through block coordinate descent method (BCD), is formulated. Additionally, the adaptive structural clustering sparse dictionary learning technique, which utilizes k-Nearest-Neighbor (kNN) clustering and principal component analysis (PCA) learning, is adopted to further enable sufficient sparsity of feature information. Moreover, the selection rule of regularization parameter and computational complexity are described in detail. The performance of the proposed framework is evaluated through numerical experiment and its superiority with respect to the state-of-the-art method in the field is demonstrated through the vibration signals of experimental rig of aircraft engine bearings.

  2. Inspiratory muscle training in patients with chronic obstructive pulmonary disease: structural adaptation and physiologic outcomes.

    Ramirez-Sarmiento, Alba; Orozco-Levi, Mauricio; Guell, Rosa; Barreiro, Esther; Hernandez, Nuria; Mota, Susana; Sangenis, Merce; Broquetas, Joan M; Casan, Pere; Gea, Joaquim

    2002-12-01

    The present study was aimed at evaluating the effects of a specific inspiratory muscle training protocol on the structure of inspiratory muscles in patients with chronic obstructive pulmonary disease. Fourteen patients (males, FEV1, 24 +/- 7% predicted) were randomized to either inspiratory muscle or sham training groups. Supervised breathing using a threshold inspiratory device was performed 30 minutes per day, five times a week, for 5 consecutive weeks. The inspiratory training group was subjected to inspiratory loading equivalent to 40 to 50% of their maximal inspiratory pressure. Biopsies from external intercostal muscles and vastus lateralis (control muscle) were taken before and after the training period. Muscle samples were processed for morphometric analyses using monoclonal antibodies against myosin heavy chain isoforms I and II. Increases in both the strength and endurance of the inspiratory muscles were observed in the inspiratory training group. This improvement was associated with increases in the proportion of type I fibers (by approximately 38%, p < 0.05) and in the size of type II fibers (by approximately 21%, p < 0.05) in the external intercostal muscles. No changes were observed in the control muscle. The study demonstrates that inspiratory training induces a specific functional improvement of the inspiratory muscles and adaptive changes in the structure of external intercostal muscles. PMID:12406842

  3. Design Process of Flight Vehicle Structures for a Common Bulkhead and an MPCV Spacecraft Adapter

    Aggarwal, Pravin; Hull, Patrick V.

    2015-01-01

    Design and manufacturing space flight vehicle structures is a skillset that has grown considerably at NASA during that last several years. Beginning with the Ares program and followed by the Space Launch System (SLS); in-house designs were produced for both the Upper Stage and the SLS Multipurpose crew vehicle (MPCV) spacecraft adapter. Specifically, critical design review (CDR) level analysis and flight production drawing were produced for the above mentioned hardware. In particular, the experience of this in-house design work led to increased manufacturing infrastructure for both Marshal Space Flight Center (MSFC) and Michoud Assembly Facility (MAF), improved skillsets in both analysis and design, and hands on experience in building and testing (MSA) full scale hardware. The hardware design and development processes from initiation to CDR and finally flight; resulted in many challenges and experiences that produced valuable lessons. This paper builds on these experiences of NASA in recent years on designing and fabricating flight hardware and examines the design/development processes used, as well as the challenges and lessons learned, i.e. from the initial design, loads estimation and mass constraints to structural optimization/affordability to release of production drawing to hardware manufacturing. While there are many documented design processes which a design engineer can follow, these unique experiences can offer insight into designing hardware in current program environments and present solutions to many of the challenges experienced by the engineering team.

  4. Adaptive resolution simulation of a biomolecule and its hydration shell: Structural and dynamical properties.

    Fogarty, Aoife C; Potestio, Raffaello; Kremer, Kurt

    2015-05-21

    A fully atomistic modelling of many biophysical and biochemical processes at biologically relevant length- and time scales is beyond our reach with current computational resources, and one approach to overcome this difficulty is the use of multiscale simulation techniques. In such simulations, when system properties necessitate a boundary between resolutions that falls within the solvent region, one can use an approach such as the Adaptive Resolution Scheme (AdResS), in which solvent particles change their resolution on the fly during the simulation. Here, we apply the existing AdResS methodology to biomolecular systems, simulating a fully atomistic protein with an atomistic hydration shell, solvated in a coarse-grained particle reservoir and heat bath. Using as a test case an aqueous solution of the regulatory protein ubiquitin, we first confirm the validity of the AdResS approach for such systems, via an examination of protein and solvent structural and dynamical properties. We then demonstrate how, in addition to providing a computational speedup, such a multiscale AdResS approach can yield otherwise inaccessible physical insights into biomolecular function. We use our methodology to show that protein structure and dynamics can still be correctly modelled using only a few shells of atomistic water molecules. We also discuss aspects of the AdResS methodology peculiar to biomolecular simulations. PMID:26001481

  5. Structural basis of evasion of cellular adaptive immunity by HIV-1 Nef

    Jia, Xiaofei; Singh, Rajendra; Homann, Stefanie; Yang, Haitao; Guatelli, John; Xiong, Yong (Yale); (VA); (UCSD)

    2012-10-24

    The HIV-1 protein Nef inhibits antigen presentation by class I major histocompatibility complex (MHC-I). We determined the mechanism of this activity by solving the crystal structure of a protein complex comprising Nef, the MHC-I cytoplasmic domain (MHC-I CD) and the {mu}1 subunit of the clathrin adaptor protein complex 1. A ternary, cooperative interaction clamps the MHC-I CD into a narrow binding groove at the Nef-{mu}1 interface, which encompasses the cargo-recognition site of {mu}1 and the proline-rich strand of Nef. The Nef C terminus induces a previously unobserved conformational change in {mu}1, whereas the N terminus binds the Nef core to position it optimally for complex formation. Positively charged patches on {mu}1 recognize acidic clusters in Nef and MHC-I. The structure shows how Nef functions as a clathrin-associated sorting protein to alter the specificity of host membrane trafficking and enable viral evasion of adaptive immunity.

  6. Adaptive resolution simulation of a biomolecule and its hydration shell: Structural and dynamical properties

    Fogarty, Aoife C.; Potestio, Raffaello; Kremer, Kurt

    2015-05-01

    A fully atomistic modelling of many biophysical and biochemical processes at biologically relevant length- and time scales is beyond our reach with current computational resources, and one approach to overcome this difficulty is the use of multiscale simulation techniques. In such simulations, when system properties necessitate a boundary between resolutions that falls within the solvent region, one can use an approach such as the Adaptive Resolution Scheme (AdResS), in which solvent particles change their resolution on the fly during the simulation. Here, we apply the existing AdResS methodology to biomolecular systems, simulating a fully atomistic protein with an atomistic hydration shell, solvated in a coarse-grained particle reservoir and heat bath. Using as a test case an aqueous solution of the regulatory protein ubiquitin, we first confirm the validity of the AdResS approach for such systems, via an examination of protein and solvent structural and dynamical properties. We then demonstrate how, in addition to providing a computational speedup, such a multiscale AdResS approach can yield otherwise inaccessible physical insights into biomolecular function. We use our methodology to show that protein structure and dynamics can still be correctly modelled using only a few shells of atomistic water molecules. We also discuss aspects of the AdResS methodology peculiar to biomolecular simulations.

  7. Application of fibre Bragg grating sensors for structural health monitoring of an adaptive wing

    This paper presents the concept of application of fibre Bragg grating (FBG) sensors for structural health monitoring (SHM) of an adaptive wing. In this concept, the shape of the wing is controlled and altered due to the wing design and the use of integrated shape memory alloy (SMA) actuators. FBG sensors are great tools for controlling the condition of composite structures due to their immunity to electromagnetic fields as well as their small size and weight. They can be mounted onto the surface or embedded into the wing skin without any significant influence on the wing strength. In the first part of the paper a determination of the twisting moments produced by activation of the SMA actuators is presented. As a first step, a numerical analysis using a finite element method (FEM) commercial code ABAQUS® is presented. Then a comparison between strain values measured by FBG sensors and determined numerically is used for determination of the real value of the activation moment of every SMA actuator. Two types of damage scenarios are analysed and discussed in the paper. The first scenario is reduction of the twisting moment values produced by one of the SMA actuators. The second scenario is outer skin damage. In both damage scenarios, a neural network is used for damage detection and localization

  8. Adaptive-frequency Resonant Harmonic-Compensator structure for a 3-phase grid-connected photovoltaic system

    Highlights: • An adaptive-frequency Harmonic-Compensation structure is used. • The frequency spectrum of the grid current is analyzed for different scenarios. • A comparison with the normative of the harmonic distortions is carried out. • The algorithms can be used in any country regardless its nominal frequency. - Abstract: In this paper, an adaptive-frequency Harmonic-Compensation structure for a Voltage Source Inverter used in a 3-phase grid-connected Photovoltaic system is presented. The main purpose is to show the frequency adaptation of the used control algorithm in order to improve the compensation of the low-order utility grid current harmonics when frequency variations occur, which can be seen as an outstanding feature when comparing to conventional non-adaptive Harmonic-Compensator structures, and can be used in any country regardless its nominal frequency and maintaining its Harmonic Compensation capability without making any change in the control algorithm. The frequency spectrum of the utility grid current is analyzed for three different scenarios: Proportional Resonant Controller without Harmonic Compensation, Proportional Resonant Controller with Harmonic Compensation, and adaptive-frequency Proportional Resonant Controller with Harmonic Compensation; a comparison with the normative of its individual and total harmonic amplitude distortions is carried out for the three situations. In order to validate the algorithms, some simulations using MATLAB/SIMULINK from The MathWorks, Inc. are shown firstly, and secondly, some real-time digital simulations are carried out

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

    Hurley Thomas D

    2007-12-01

    Full Text Available Abstract 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 part of the substrate and inhibitor binding pocket. This adaptability is important for accommodating inhibitors with variations in size. When compared with the human isozymes, this loop either becomes buried in the human type I enzyme due to an N-terminal extension that covers its position or is replaced by a unique insert in the human type II enzyme. Conclusion The adaptability of the YHGY loop in E. coli methionine aminopeptidase, and likely in other bacterial methionine aminopeptidases, enables the enzyme active pocket to accommodate inhibitors of differing size. The differences in this adaptable loop between the bacterial and human methionine aminopeptidases is a structural feature that can be exploited to design inhibitors of bacterial methionine aminopeptidases as therapeutic agents with minimal inhibition of the corresponding human enzymes.

  10. Micro-ion beam analysis of physico-chemical reactions in vitro induced by nano-structured sol-gel derived bioactive glasses

    The study of bioactive glasses is a multi-field area of research aiming at a major goal: the development of new generation biomaterials that would be able to bond with host tissues through the formation of a strong interfacial bond, together with helping the body heal itself through the stimulation of specific cellular responses. Thus clinical applications of bioactive glasses mainly concern dental surgery and orthopedics, for filling osseous defects. For this purpose, we have elaborated bioactive glasses in the binary SiO2-CaO system, ternary SiO2-CaO-P2O5 system, and for the first time, to our knowledge, strontium-doped SiO2-CaO-SrO and SiO2-CaO-P2O5-SrO glasses. The materials were elaborated using the sol-gel process, which allowed the synthesis of nano-porous materials with great purity and homogeneity. The bio-activity of the glasses was clearly demonstrated in vitro: in contact with biological fluids, the whole lot of mate-rials were able to induce the formation of a Ca-P-Mg layer a few microns thick at their surface. Our work is characterized by the use of PIXE-RBS nuclear microprobes to study the bioactive glass/biological fluids interface. Thanks to these methods we obtained chemical maps that made possible the analysis of major and trace elements concentrations at the interface. Moreover, quantitative information regarding the local reactivity of glasses were acquired. These data are important to evaluate the kinetics and amplitude of the physico-chemical reactions involved in the bio-activity process. Thus, we highlighted that the binary glass is the highest reactive regarding the dissolution of the glassy matrix as well as the first appearance of the Ca-P rich layer. However the Ca/P atomic ratio calculated at the glass/biological fluids interface decreases slowly, indicating that the Ca-P-Mg layer encounters difficulties to be changed into a more stable apatitic phase. For the P-containing glasses, the de-alkalinization of the matrix and the formation

  11. Ambiguous Adaptation

    Møller Larsen, Marcus; Lyngsie, Jacob

    We investigate why some exchange relationships terminate prematurely. We argue that investments in informal governance structures induce premature termination in relationships already governed by formal contracts. The formalized adaptive behavior of formal governance structures and the flexible and...... reciprocal adaptation of informal governance structure create ambiguity in situations of contingencies, which, subsequently, increases the likelihood of premature relationship termination. Using a large sample of exchange relationships in the global service provider industry, we find support for a hypothesis...

  12. Adaptive variable structure control for large-scale time-delayed systems with unknown nonlinear dead-zone

    Shen Qikun; Zhang Tianping

    2007-01-01

    The problem of adaptive fuzzy control for a class of large-scale, time-delayed systems with unknown nonlinear dead-zone is discussed here. Based on the principle of variable structure control, a design scheme of adaptive, decentralized, variable structure control is proposed. The approach removes the conditions that the dead-zone slopes and boundaries are equal and symmetric, respectively. In addition, it does not require that the assumptions that all parameters of the nonlinear dead-zone model and the lumped uncertainty are known constants. The adaptive compensation terms of the approximation errors are adopted to minimize the influence of modeling errors and parameter estimation errors. By theoretical analysis, the closed-loop control system is proved to be semiglobally uniformly ultimately bounded, with tracking errors converging to zero. Simulation results demonstrate the effectiveness of the approach.

  13. Multiclass Classification by Adaptive Network of Dendritic Neurons with Binary Synapses Using Structural Plasticity.

    Hussain, Shaista; Basu, Arindam

    2016-01-01

    The development of power-efficient neuromorphic devices presents the challenge of designing spike pattern classification algorithms which can be implemented on low-precision hardware and can also achieve state-of-the-art performance. In our pursuit of meeting this challenge, we present a pattern classification model which uses a sparse connection matrix and exploits the mechanism of nonlinear dendritic processing to achieve high classification accuracy. A rate-based structural learning rule for multiclass classification is proposed which modifies a connectivity matrix of binary synaptic connections by choosing the best "k" out of "d" inputs to make connections on every dendritic branch (k classification problem, a two-step solution is proposed. First, an adaptive approach is proposed which scales the relative size of the dendritic trees of neurons for each class. It works by progressively adding dendrites with fixed number of synapses to the network, thereby allocating synaptic resources as per the complexity of the given problem. As a second step, theoretical capacity calculations are used to convert each neuronal dendritic tree to its optimal topology where dendrites of each class are assigned different number of synapses. The performance of the model is evaluated on classification of handwritten digits from the benchmark MNIST dataset and compared with other spike classifiers. We show that our system can achieve classification accuracy within 1 - 2% of other reported spike-based classifiers while using much less synaptic resources (only 7%) compared to that used by other methods. Further, an ensemble classifier created with adaptively learned sizes can attain accuracy of 96.4% which is at par with the best reported performance of spike-based classifiers. Moreover, the proposed method achieves this by using about 20% of the synapses used by other spike algorithms. We also present results of applying our algorithm to classify the MNIST-DVS dataset collected from a

  14. The role of physicochemical and structural surface properties in co-adhesion of microbial pairs in a parallel-plate flow chamber

    Bos, R; van der Mei, Henderina; de Vries, Jacob; Busscher, HJ

    1996-01-01

    Biofilm formation on solid surfaces involves interactions between planktonic organisms and the substratum as well as between flowing and already adhering organisms (''co-adhesion''). Biochemical studies have yielded information on the structural cell surface properties involved in interspecies bindi

  15. Structural and psycho-social limits to climate change adaptation in the great barrier reef region

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

    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...

  16. Stochastic Physicochemical Dynamics

    Tsekov, Roumen

    2001-01-01

    The monograph considers thermodynamic relaxation in quantum systems, stochastic dynamics of gas molecules, fluctuation stability of thin liquid films, resonant diffusion in modulated solid structures and catalytic kinetics of chemical dissociation.

  17. Using Structural Equation Modeling to Validate Online Game Players' Motivations Relative to Self-Concept and Life Adaptation

    Yang, Shu Ching; Huang, Chiao Ling

    2013-01-01

    This study aimed to validate a systematic instrument to measure online players' motivations for playing online games (MPOG) and examine how the interplay of differential motivations impacts young gamers' self-concept and life adaptation. Confirmatory factor analysis determined that a hierarchical model with a two-factor structure of…

  18. Unraveling the effect of genomic structural changes in the rhesus macaque - implications for the adaptive role of inversions

    Ullastres, Ana; Farré, Marta; Capilla, Laia; Ruiz-Herrera, Aurora

    2014-01-01

    Background By reshuffling genomes, structural genomic reorganizations provide genetic variation on which natural selection can work. Understanding the mechanisms underlying this process has been a long-standing question in evolutionary biology. In this context, our purpose in this study is to characterize the genomic regions involved in structural rearrangements between human and macaque genomes and determine their influence on meiotic recombination as a way to explore the adaptive role of ge...

  19. Screen image sequence compression method utilizing adaptive block size coding and hierarchical GOP structure

    WU Xing; MEI Liang; XI Qi; ZHANG Shen-sheng; CHEN Yan-wei

    2010-01-01

    To compress screen image sequence in real-time remote and interactive applications,a novel compression method is proposed.The proposed method is named as CABHG.CABHG employs hybrid coding schemes that consist of intra-frame and inter-frame coding modes.The intra-frame coding is a rate-distortion optimized adaptive block size that can be also used for the compression of a single screen image.The inter-frame coding utilizes hierarchical group of pictures(GOP)structure to improve system performance during random accesses and fast-backward scans.Experimental results demonstrate that the proposed CABHG method has approximately 47%-48% higher compression ratio and 46%-53% lower CPU utilization than professional screen image sequence codecs such as TechSmith Ensharpen codec and Sorenson 3 codec.Compared with general video codecs such as H.264codec,XviD MPEG-4 codec and Apple's Animation codec,CABHG also shows 87%-88% higher compression ratio and 64%-81%lower CPU utilization than these general video codecs.

  20. Exchange repulsive potential adaptable for electronic structure changes during chemical reactions

    Hybrid methods combining quantum mechanical (QM) and classical calculations are becoming important tools in chemistry. The popular approach to calculate the interaction between QM and classical calculations employs interatomic potentials. In most cases, the interatomic potential is constructed of an electrostatic (ES) potential and a non-ES potential. Because QM treatment is employed in the calculation of the ES potential, the electronic change can be considered in this ES potential. However, QM treatment of the non-ES potential is difficult because of high computational cost. To overcome this difficulty of evaluating the non-ES potential, we proposed an exchange repulsive potential as the main part of the non-ES potential on the basis of a QM approach. This potential is independent of empirical parameters and adaptable for electronic structure. We combined this potential with the reference interaction site model self-consistent field explicitly including spatial electron density distribution and successfully applied it to the chemical reactions in aqueous phase

  1. Adaptive selective ES-FEM limit analysis of cracked plane-strain structures

    H. NGUYEN-XUAN[1; T. RABCZUK[2

    2015-01-01

    This paper presents a simple and efficient approach for predicting the plastic limit loads in cracked plane- strain structures. We use two levels of mesh repartitioning for the finite element limit analysis. The master level handles an adaptive primal-mesh process through a dissipation-based indicator. The slave level performs the subdivision of each triangle into three sub-triangles and constitutes a dual mesh from a pair of two adjacent sub-triangles shared by common edges of the primal mesh. Applying a strain smoothing projection to the strain rates on the dual mesh, the incompressibility constraint and the flow rule constraint are imposed over the edge-based smoothing domains and everywhere in the problem domain. The limit analysis problem is recast into the compact form of a second-order cone programming (SOCP) for the purpose of exploiting interior-point solvers. The present method retains a low number of optimization variables. It offers a convenient way for designing and solving the large-scale optimization problems effectively. Several benchmark examples are given to show the simplicity and effectiveness of the present method.

  2. Complex band structure eigenvalue method adapted to Floquet systems: topological superconducting wires as a case study

    For systems that can be modeled as a single-particle lattice extended along a privileged direction, such as, for example, quantum wires, the so-called eigenvalue method provides full information about the propagating and evanescent modes as a function of energy. This complex band structure method can be applied either to lattices consisting of an infinite succession of interconnected layers described by the same local Hamiltonian or to superlattices: systems in which the spatial periodicity involves more than one layer. Here, for time-dependent systems subject to a periodic driving, we present an adapted version of the superlattice scheme capable of obtaining the Floquet states and the Floquet quasienergy spectrum. Within this scheme the time periodicity is treated as existing along a spatial dimension added to the original system. The solutions at a single energy for the enlarged artificial system provide the solutions of the original Floquet problem. The method is suited for arbitrary periodic excitations, including strong and anharmonic drivings. We illustrate the capabilities of the methods for both time-independent and time-dependent systems by discussing: (a) topological superconductors in multimode quantum wires with spin–orbit interaction and (b) microwave driven quantum dots in contact with a topological superconductor. (paper)

  3. Investigation of instabilities affecting detonations: Improving the resolution using block-structured adaptive mesh refinement

    Ravindran, Prashaanth

    The unstable nature of detonation waves is a result of the critical relationship between the hydrodynamic shock and the chemical reactions sustaining the shock. A perturbative analysis of the critical point is quite challenging due to the multiple spatio-temporal scales involved along with the non-linear nature of the shock-reaction mechanism. The author's research attempts to provide detailed resolution of the instabilities at the shock front. Another key aspect of the present research is to develop an understanding of the causality between the non-linear dynamics of the front and the eventual breakdown of the sub-structures. An accurate numerical simulation of detonation waves requires a very efficient solution of the Euler equations in conservation form with detailed, non-equilibrium chemistry. The difference in the flow and reaction length scales results in very stiff source terms, requiring the problem to be solved with adaptive mesh refinement. For this purpose, Berger-Colella's block-structured adaptive mesh refinement (AMR) strategy has been developed and applied to time-explicit finite volume methods. The block-structured technique uses a hierarchy of parent-child sub-grids, integrated recursively over time. One novel approach to partition the problem within a large supercomputer was the use of modified Peano-Hilbert space filling curves. The AMR framework was merged with CLAWPACK, a package providing finite volume numerical methods tailored for wave-propagation problems. The stiffness problem is bypassed by using a 1st order Godunov or a 2nd order Strang splitting technique, where the flow variables and source terms are integrated independently. A linearly explicit fourth-order Runge-Kutta integrator is used for the flow, and an ODE solver was used to overcome the numerical stiffness. Second-order spatial resolution is obtained by using a second-order Roe-HLL scheme with the inclusion of numerical viscosity to stabilize the solution near the discontinuity

  4. Soil Architecture and physicochemical functions

    de Jonge, Lis Wollesen; Møldrup, Per; Vendelboe, Anders Lindblad;

    2012-01-01

    generation of environmentalists, soil scientists, and environmental engineers with the best education possible. The 16 papers in this special section on soil architecture and physicochemical functions in the Vadose Zone Journal contribute to these goals by improving and linking measurement, visualization...

  5. Physico-chemical wastewater treatment

    Mels, A.R.; Teerikangas, E.

    2002-01-01

    Wastewater reclamation strategies aimed at closing industrial water cycles and recovery of valuable components will in most cases require a combination of wastewater treatment unit operations. Biological unit operations are commonly applied as the core treatment. In addition, physico-chemical unit o

  6. 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

    2011-05-01

    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) lower total muscle power output. To test these hypotheses, we used three-dimensional joint mechanical measurements and a simple model to estimate the elastic and muscle contributions to joint work and power. Contradictory to our first hypothesis, we found that ostriches and humans generate the same amounts of mechanical power to swing the limbs at a similar self-selected running speed, indicating that limb swing probably does not contribute to the difference in energy cost of running between these species. In contrast, we estimated that ostriches generate 120 per cent more stance-phase mechanical joint power via release of elastic energy compared with humans. This elastic mechanical power occurs nearly exclusively at the tarsometatarso-phalangeal joint, demonstrating a shift of mechanical power generation to distal joints compared with humans. We also estimated that positive muscle fibre power is 35 per cent lower in ostriches compared with humans, and is accounted for primarily by higher capacity for storage and release of elastic energy. Furthermore, our analysis revealed much larger frontal and internal/external rotation joint loads during ostrich running than in humans. Together, these findings support the hypothesis that a primary limb structure specialization linked to economical running in cursorial species is an elevated storage and release of elastic energy in tendon. In the ostrich, energy-saving specializations may also include passive frontal and internal

  7. Two factors defining humus as a key structural component of soil organic matter and as a physicochemical speciation of carbon in its turnover wending its way through the micro environment of soil, sediments and natural waters

    Aleksandrova, Olga

    2016-04-01

    on a change in the partitioning of roaming H-bonds, and in turn, define components, into which non-humified SOM can be disintegrated. Therefore, some physicochemical species of SOM, which can be observed in physicochemical processes of carbon turnover in soil, originate from disintegrated SOM bulged at the seams of weak H-bonds, and doesn't reveal strong properties of humus because humus structure is still bound to SOM via stronger H-bonds. Also, SL EPR examination of native and labeled soil samples revealed the substantial influence of hydrophobic interaction on physicochemical speciation of carbon in soil, and this interaction is mediated by humus [3]. Among different effects of hydrophobic interaction, the formation of condensed matter is of great interest. Condensed matter mediated by humic acids is shown to reveal specific quantum properties and invoke hydrodynamic instability on the surface of plant roots that results in uptake of the whole nano-pieces of humus by plant roots, as it was observed in [6, 7]. Considered effects of H-bonds with different bonding energy and hydrophobic interaction in SOM show that a carbon turnover in soil is mediated by humus, and humus play a substantial role as the physicochemical speciation in carbon turnover. Thus, model of 'humus' is still an up-to-date model. 1.Lehmann J. &Kleber H. (2015). Nature, 528, Issue 7580, 60 - 68. 2. M. Hutta, R. Gora, R. Halko, et al., (2011). J. Chromatogr. A., 1218, 8946. 3. Alexanderova O.N. (2015). J Soils Sediments, DOI 10.1007/s11368-015-1195-2 4. Aleksandrova O.N., Kholodov V.A., Perminova I.V. (2015). Russian Journal of Physical Chemistry A, 2015, Vol. 89, No. 8, pp. 1407-1413. 5. Aleksandrova O.N. (2013). J Geochem Explor 129:6-13. 6. Smirnov A.I. et al. (1991). J. of Magnetic Resonance 91, 386-391 7. Kulikova N.V. et al. (2012). Conference HIT-2012.

  8. The GaCl3-detector of the GALLEX-experiment for the measurement of solar neutrinos - physicochemical data and properties of GaCl3-solution and structural materials

    Laboratory tests comprised: 1. Physicochemical data of the detector solution, e.g. density, viscosity, surface tension etc. of the highly concentrated, hydrochloric GaCl3-solution. 2. The volatility of HCl and H2O, so that the depletion of these solution components during the course of the experiment can be estimated. Particularly important is a knowledge of the volatility of Ge, the product of the nuclear reaction of the neutrinos with Ga, which must be quantitatively separated and measured. The desorption of GeCl4 from the GaCl3 solution follows an exponential rate down to residual concentrations of c/c0 = 10-4. The last traces are trapped in the solution in a less volatile form. This effect was studied. A Ge-desorption test was carried out routinely as a quality control on all delivery charges of the GaCl3-solution (100 t) from the supplier. 3. The longtime stability of the structural materials in the aggressive GaCl3-solution had to be assured. Most important are the PVDF liner of the detector tank made of glassfiber-reinforced vinylester plastic, the absorption columns and their packings made of glass, and containers and tanks made of polypropylene (PP) serving as transport vessels or for emergency situations (leakage). In addition it had to be ascertained that Ge was not trapped by adsorption of diffusion at the walls of the tank or the absorption columns. (orig./HP)

  9. A Knowledge-Structure-Based Adaptive Dynamic Assessment System for Calculus Learning

    Ting, M.-Y.; Kuo, B.-C.

    2016-01-01

    The purpose of this study was to investigate the effect of a calculus system that was designed using an adaptive dynamic assessment (DA) framework on performance in the "finding an area using an integral". In this study, adaptive testing and dynamic assessment were combined to provide different test items depending on students'…

  10. Evaluating Knowledge Structure-Based Adaptive Testing Algorithms and System Development

    Wu, Huey-Min; Kuo, Bor-Chen; Yang, Jinn-Min

    2012-01-01

    In recent years, many computerized test systems have been developed for diagnosing students' learning profiles. Nevertheless, it remains a challenging issue to find an adaptive testing algorithm to both shorten testing time and precisely diagnose the knowledge status of students. In order to find a suitable algorithm, four adaptive testing…

  11. Factor structure of the relationship of indicators of physical condition and learning to adapt to younger students

    Lyasota T.I.

    2012-03-01

    Full Text Available The experience of the use of factor analysis in the research of specialists in physical education was studied. It is studied interrelation of indexes that characterize indexes of physical state, motive activity, level of disease and adaptation to the conditions of education at school. The experiment, which was attended by 34 girls and 30 boys 6 and 7 years of age, found that the most significant contribution to the factor structure are data on the physical development of school-age children, as well as indicators of physical fitness of patients. It is proved that between the child's adaptation to social changes and physical activity there is a deep connection.

  12. Ventricular structure, function, and mechanics at high altitude: chronic remodeling in Sherpa vs. short-term lowlander adaptation

    Stembridge, Mike; Ainslie, Philip N; Hughes, Michael G.; Stöhr, Eric J.; Cotter, James D.; Nio, Amanda Q. X.; Shave, Rob

    2014-01-01

    Short-term, high-altitude (HA) exposure raises pulmonary artery systolic pressure (PASP) and decreases left-ventricular (LV) volumes. However, relatively little is known of the long-term cardiac consequences of prolonged exposure in Sherpa, a highly adapted HA population. To investigate short-term adaptation and potential long-term cardiac remodeling, we studied ventricular structure and function in Sherpa at 5,050 m (n = 11; 31 ± 13 yr; mass 68 ± 10 kg; height 169 ± 6 cm) and lowlanders at s...

  13. Time-space adaptive simulation of incompressible flows and fluid-structure interaction on the Cray SV1

    This paper addresses the adaptive simulation of incompressible flows and of fluid-structure interaction problems, with special emphasis on the efficient use of the parallel vector resources of the Cray SV1 machine. The continuum model is based on the incompressible Navier-Stokes equations, written in primitive variables, and includes the Boussinesq approximation of thermally induced buoyancy forces. Arbitrary Lagrangian-Eulerian (ALE) co-ordinates are used when dealing with fluid-structure interaction problems. These problems are important in various branches of engineering and, in particular, in the design and analysis of the heat transfer equipment of nuclear power plants. Adaptive simulations of free and forced convection flows and of fluid-structure interaction problems are presented. Performance measurements on the Cray SV1 demonstrate the effectiveness of the numerical techniques employed. (authors)

  14. The crystal structure and physicochemical characteristics of 2-hydroxy-N-[3(5)-pyrazolyl]-1,4-naphthoquinone-4-imine, a new antitrypanosomal compound

    Sperandeo, Norma R.; Karlsson, Alicia; Cuffini, Silvia; Pagola, Silvina; Stephens, Peter W.

    2005-01-01

    This study was designed to investigate the physical characteristics and crystalline structure of 2-hydroxy-N-[3(5)-pyrazolyl]-1,4-naphthoquinone-4-imine (PNQ), a new active compound againstTrypanosoma cruzi, the causative agent of American trypanosomiasis. Methods used included differential scanning calorimetry, thermogravimetry, hot stage microscopy, polarized light microscopy (PLM), Fourier-transform infrared (FTIR) spectroscopy, and high-resolution X-ray powder diffraction (HR-XRPD). Accor...

  15. The crystal structure and physicochemical characteristics of 2-hydroxy-N-[3(5)-pyrazolyl]-1,4-naphthoquinone-4-imine, a new antitrypanosomal compound.

    Sperandeo, Norma R; Karlsson, Alicia; Cuffini, Silvia; Pagola, Silvina; Stephens, Peter W

    2005-01-01

    This study was designed to investigate the physical characteristics and crystalline structure of 2-hydroxy-N-[3(5)-pyrazolyl]-1,4-naphthoquinone-4-imine (PNQ), a new active compound against Trypanosoma cruzi, the causative agent of American trypanosomiasis. Methods used included differential scanning calorimetry, thermogravimetry, hot stage microscopy, polarized light microscopy (PLM), Fourier-transform infrared (FTIR) spectroscopy, and high-resolution X-ray powder diffraction (HR-XRPD). According to PLM and HR-XRPD data, PNQ crystallized as red oolitic crystals (absolute methanol) or prisms (dimethyl sulfoxide [DMSO]-water) with the same internal structure. The findings obtained with HR-XRPD data (applying molecular location methods) showed a monoclinic unit cell [a = 18.4437(1) A, b = 3.9968(2) A, c = 14.5304(1) A, alpha = 90 degrees , beta = 102.71(6) degrees , gamma = 90 degrees , V = 1044.9(1) A(3), Z = 4, space group P2(1)/c], and a crystal structure (excluding H-positions) described by parallel layers in the direction of the b-axis, with molecules held by homochemical (phenyl-phenyl and pyrazole-pyrazole) van der Waals interactions. In addition, FTIR spectra displayed the NH-pyrazole stretch overlapped with the OH absorption at 3222 cm(-1), typical of -NH and -OH groups associated through H-bondings; and a carbonyl stretching absorption at 1694 cm(-1), indicating a nonextensively H-bonded quinonic C=O, which was in accordance with the solved crystal structure of PNQ. The existence of such cohesive forces shed light on the thermoanalytical data, which revealed that PNQ is a stable solid, unaffected by oxygen that decomposed without melting above 260 degrees C. PMID:16408868

  16. Germination and microwave processing of barley (Hordeum vulgare L) changes the structural and physicochemical properties of β-d-glucan & enhances its antioxidant potential.

    Ahmad, Mudasir; Gani, Adil; Shah, Asima; Gani, Asir; Masoodi, F A

    2016-11-20

    The nutraceutical potential of β-d-glucan is largely dependent on its structure, size and viscosity. The present study analyzed the effect of germination and microwave processing of barley on the structural, size, antioxidant and thermal characteristics of β-d-glucan. The molecular weight and viscosity of β-d-glucan obtained from germinated barley (GGB) were the lowest (144kDa and 37.33cp) as compared to β-d-glucan from microwave processed barley (GMB) and unprocessed barley (GUB). The GGB exhibited higher antioxidant potential than GMB and GUB. The Structural elucidation by ATR-FTIR revealed scission in polymeric chain and β glycosydic linkage of β-d-glucan obtained from processed barley. The highest peak intensity at glycosydic linkage in GGB confirms more scission in the molecule. The DSC curve of GGB showed the highest transition temperature. It was concluded that germination of barley can be a good approach for enhancing the antioxidant potential of β-d-glucan. PMID:27561541

  17. New process of preparation, structure, and physicochemical investigations of the new titanyl phosphate Ti2O(H2O)(PO4)2

    New titanyl phosphate Ti2O(H2O)(PO4)2 has been prepared and characterized by X-ray and neutron diffraction, nuclear magnetic resonance, infrared and Raman spectroscopies and thermogravimetric analysis. The crystal structure has been solved from neutron powder diffraction data at 300 K by Rietveld method in P21 space group. The refinement led to satisfactory profile factors (Rp=2.7%, Rwp=3.2%) and crystal structure model indicators (RB=5.8%, RF=3.2%). The cell is monoclinic with a=7.3735 A, b=7.0405 A, c=7.6609 A and β=121.48o, Z=4. The structure can be described as a three-dimensional framework built up by chains of [TiO5(OH2)] octahedra with alternative short bonds [Ti(1)-O(12); Ti(2)-O(12), 1.88-1.84 A] and long ones [Ti(1)-OW; Ti(2)-OW, 2.25-2.23 A] along c-axis and connected via [PO4] tetrahedra. Oxygen atom denoted O(12) is only linked to two titanium atoms and Oxygen atom denoted OW is linked to two titanium atoms and two hydrogen atoms. O(12) and OW are not linked to P atoms and justify the titanyl phosphate formulation Ti2O(H2O)(PO4)2. The infrared and Raman spectra presents peaks due to vibrations of Ti-O, P-O and O-H bonds. The 31P MAS NMR spectrum reveals two 31P resonance lines, in agreement with the structure which showed two crystallographic sites for phosphorus. The thermogravimetric analysis show that Ti2O(H2O)(PO4)2 is thermally stable until 400 deg. C. Above this temperature, it losses water and decomposes to Ti5O4(PO4)4 and TiP2O7. - Graphical abstract: The structure of TiHP can be described as a TiOPO4 framework constituted by chains of tilted corner-sharing [TiO6] octahedra and cross linked by [PO4] tetrahedra with empty cavities in the framework

  18. Syntheses, structural characterizations and physico-chemical properties of tetravalent elements fluorides; Syntheses, caracterisations structurales et physico-chimiques de fluorures d'elements tetravalents

    Mapemba Moulakou, E

    2007-07-15

    This work initially was devoted to the study of phase relationship in the ternary system KF-MnF{sub 2}-ZrF{sub 4}. During the study in this system the compound of KMn.ZrF{sub 7} has been evidenced. The crystal structure determination allowed to show the opportunity to substitute two rare earths Ln{sup 3+} for the couple Zr{sup 4+} and Mn{sup 2+} without any charge compensation. This study also allowed to clarify the phase-relationship in the binary system KF-ZrF{sub 4}. The study of the insertion of lithium ions in tetravalent lanthanides or actinides fluorides led to the obtention of a new phase Li{sub 5,5}Ce{sub 12}F{sub 50}. The crystal structure determination revealed the simultaneous presence of Ce{sup 4+} in 8 and 9-coordination building tetra-meric units as well as Ce{sup 3+} and Ce{sup 3+}/Ce{sup 4+} (in statistical distribution) encompassed in isolated in 8-coordination polyhedra. In the light of this result we have revised the study of the LiM{sub 4}F{sub 17} phases initially reported as belonging to the binary systems LiF-MF{sub 4} (M = Ce, U, Th) and shown that these phases were in fact mixed valence (III/IV) fluorinated compounds. A new method of mixed valence fluorides synthesis by electrochemical intercalation of lithium ions in the host matrix has been developed. To this aim containing Ce, Tb, U, Th have been tested. Finally this research work has been extended to the study of fluoro-zirconates and fluoro-terbates of formula LiLniMF{sub 8} (M = Zr and Tb). The structural characterization of these LiLnMF{sub 8} compounds allowed to show the existence of structural relationships with the fluorides LiNaY{sub 2}F{sub 8}. LiNaYb{sub 2}F{sub 8} and BaY{sub 2}F{sub 8}. These compounds LiLnMF{sub 8} (M = Zr and Tb) exhibit open structures susceptible to enhance the diffusion of the alkaline ions. Thus the intercalation and de-intercalation of the alkaline ions in the LiY TbF{sub 8} host matrix allowed the obtention of new mixed valence fluorinated compounds

  19. Guest-responsive structural adaptation of a rationally-designed molecular tweezer based on Tröger’s base

    Ishita Neogi; Alankriti Bajpai; Jarugu Narasimha Moorthy

    2014-09-01

    We have designed and synthesized a modified Tröger’s base TB in which the sterically-rigidified aryl rings that protrude into its groove were envisaged to preclude self-inclusion. From a limited preliminary experimentation, TB has been found to exhibit guest inclusion. The X-ray determined structures of the crystals of guest-free TB and its inclusion compounds with acetonitrile and -dichlorobenzene reveal remarkable adaptability of the TB core to undergo subtle structural changes in response to the guest that is included. The structural analyses demonstrate the fact that TB behaves like a molecular tweezer.

  20. MAPPING THE CLUMPY STRUCTURES WITHIN SUBMILLIMETER GALAXIES USING LASER-GUIDE STAR ADAPTIVE OPTICS SPECTROSCOPY

    We present the first integral-field spectroscopic observations of high-redshift submillimeter-selected galaxies (SMGs) using Laser-Guide Star Adaptive Optics. We target Hα emission of three SMGs at redshifts z ∼ 1.4-2.4 with the OH-Suppressing Infrared Imaging Spectrograph on Keck. The spatially resolved spectroscopy of these galaxies reveals unresolved broad-Hα line regions (FWHM >1000 km s–1) likely associated with an active galactic nucleus (AGN) and regions of diffuse star formation traced by narrow-line Hα emission (FWHM ∼–1) dominated by multiple Hα-bright stellar clumps, each contributing 1%-30% of the total clump-integrated Hα emission. We find that these SMGs host high star formation rate surface densities, similar to local extreme sources, such as circumnuclear starbursts and luminous infrared galaxies. However, in contrast to these local environments, SMGs appear to be undergoing such intense activity on significantly larger spatial scales as revealed by extended Hα emission over 4-16 kpc. Hα kinematics show no evidence of ordered global motion as would be found in a disk, but rather large velocity offsets (∼few × 100 km s–1) between the distinct stellar clumps. Together with the asymmetric distribution of the stellar clumps around the AGN in these objects, it is unlikely that we are unveiling a clumpy disk structure as has been suggested in other high-redshift populations of star-forming galaxies. The SMG clumps in this sample may correspond to remnants of originally independent gas-rich systems that are in the process of merging, hence triggering the ultraluminous SMG phase.

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

    Aleksandra Kroemeke

    2015-02-01

    The obtained results indicated very high reliability and accuracy for the Polish adaptation of the SPA. The tool can be used as a predictor and/or indicator of successful aging and life quality of seniors.

  2. Parallel Simulation of the Shallow Water Equations on Structured Dynamically Adaptive Triangular Grids.

    Vigh, Csaba Attila

    2013-01-01

    One of the most important computational challenges in the context of the numerical treatment of Partial Differential Equations is the generation, management, and dynamic adaptivity of grids. Dynamic adaptivity is extremely important in applications that require frequent changes of the grid pattern during a simulation run. One such application example is Tsunami simulation, where waves have to be tracked with highly resolved local grids. Arbitrary unstructured grids that can ...

  3. Physicochemical characterization of Gozitan Honey

    Everaldo Attard; Joseph Mizzi

    2013-01-01

    Honey quality is clearly defined in the EU Directive 2001/110/EC, and by Codex Alimentarius (Codex Stan 12-1981) and the International Honey Commission (IHC, 2002). Our investigation aimed to characterize the physicochemical properties of honey produced on a small island, Gozo which is situated near Malta.  Ten randomly collected honey samples were analysed for moisture content, pH, free acidity, water insoluble content, hydroxymethylfurfural (HMF) content and total phenolic compounds.  Moist...

  4. Effects of gamma ray and electron beam irradiation on the mechanical, thermal, structural and physicochemical properties of poly (ether-block-amide) thermoplastic elastomers.

    Murray, Kieran A; Kennedy, James E; McEvoy, Brian; Vrain, Olivier; Ryan, Damien; Cowman, Richard; Higginbotham, Clement L

    2013-01-01

    Both gamma ray and electron beam irradiation are widely used as a means of medical device sterilisation. However, it is known that the radiation produced by both processes can lead to undesirable changes within biomedical polymers. The main objective of this research was to conduct a comparative study on the two key radiosterilisation methods (gamma ray and electron beam) in order to identify the more detrimental process in terms of the mechanical, structural, chemical and thermal properties of a common biomedical grade polymer. Poly (ether-block-amide) (PEBA) was prepared by injection moulding ASTM testing specimens and these were exposed to an extensive range of irradiation doses (5-200 kGy) in an air atmosphere. The effect of varying the irradiation dose concentration on the resultant PEBA properties was apparent. For instance, the tensile strength, percentage elongation at break and shore D hardness can be increased/decreased by controlling the aforementioned criteria. In addition, it was observed that the stiffness of the material increased with incremental irradiation doses as anticipated. Melt flow index demonstrated a dramatic increase in the melting strength of the material indicating a sharp increase in molecular weight. Conversely, modulated differential scanning calorimetry established that there were no significant alterations to the thermal transitions. Noteworthy trends were observed for the dynamic frequency sweeps of the material, where the crosslink density increased according to an increase in electron beam irradiation dose. Trans-vinylene unsaturations and the carbonyl group concentration increased with an increment in irradiation dose for both processes when observed by FTIR. The relationship between the irradiation dose rate, mechanical properties and the subsequent surface properties of PEBA material is further elucidated throughout this paper. This study revealed that the gamma irradiation process produced more adverse effects in the PEBA

  5. STRUCTURAL ADAPTATIONS OF CELLULAR WALLS OF AQUATIC PLANTS TO THE ACTION OF IONS OF ZINC AND LEAD

    Grubinko V.V.

    2012-11-01

    Full Text Available Main specific and nonspecific cells responses and membrane structures participation in formation of cells resistance in stress conditions, caused by heavy metals (chlorella, waterweed, duckweed in toxic concentrations are analyzed. The cell membranes participation in adaptation to toxicants (formation of growths, multiplication, fluidization, forming of aquaporin, apoptosis, which are first exposed to stressors, is discussed. Found specific and nonspecific reactions in membrane formation are proposed to use as biomarkers of toxicity.

  6. Características estruturais e físico-químicas de amidos de mandioquinha-salsa (Arracacia xanthorrhiza Structural and physicochemical characteristics of Peruvian carrot (Arracacia xanthorrhiza starch

    Thaís Souza Rocha

    2008-09-01

    Full Text Available O amido apresenta propriedades físico-químicas importantes que são dependentes de sua fonte botânica e de suas características estruturais. O amido de mandioquinha-salsa possui características especiais que o tornam elegível para utilização em vários alimentos processados. Neste trabalho, amidos de duas variedades de mandioquinha-salsa, Amarela de Carandaí (AC e Amarela de Senador Amaral (ASA, foram isolados e suas características físico-químicas e estruturais determinadas. O amido obtido da variedade ASA apresentou grânulos com diâmetro médio maior que aqueles da variedade AC e mais que o dobro da quantidade de grânulos com tamanho >20 µm, quando comparado à outra variedade. Os amidos de ambas as variedades, observados em microscópio eletrônico de varredura, mostraram superfícies granulares lisas com formatos circulares e poliédricos para grânulos grandes e pequenos, respectivamente. A distribuição de tamanho molecular, viscosidade intrínseca e índice de cristalinidade dos amidos de ambas as variedades foram semelhantes, porém o teor de amilose foi maior para o amido da variedade AC. Maiores valores de viscosidade, poder de inchamento, e temperaturas de gelatinização foram observados para o amido da variedade ASA e podem estar relacionados ao menor teor de amilose e à maior proporção de grânulos grandes apresentados por este amido.Starch has very important physicochemical properties that depend on its botanical source and structural characteristics. Peruvian carrot starch displays special characteristics, which make it appropriate for industrial application in many processed foods. In this work, starch from two Peruvian carrot varieties, Amarela de Carandaí (AC and Amarela de Senador Amaral (ASA, were isolated and their physicochemical and structural properties were determined. Starch from the ASA variety exhibited granules with a greater average diameter than those from the AC variety and more than double

  7. Enhanced oxygen vacancy diffusion in Ta2O5 resistive memory devices due to infinitely adaptive crystal structure

    Jiang, Hao; Stewart, Derek A.

    2016-04-01

    Metal oxide resistive memory devices based on Ta2O5 have demonstrated high switching speed, long endurance, and low set voltage. However, the physical origin of this improved performance is still unclear. Ta2O5 is an important archetype of a class of materials that possess an adaptive crystal structure that can respond easily to the presence of defects. Using first principles nudged elastic band calculations, we show that this adaptive crystal structure leads to low energy barriers for in-plane diffusion of oxygen vacancies in λ phase Ta2O5. Identified diffusion paths are associated with collective motion of neighboring atoms. The overall vacancy diffusion is anisotropic with higher diffusion barriers found for oxygen vacancy movement between Ta-O planes. Coupled with the fact that oxygen vacancy formation energy in Ta2O5 is relatively small, our calculated low diffusion barriers can help explain the low set voltage in Ta2O5 based resistive memory devices. Our work shows that other oxides with adaptive crystal structures could serve as potential candidates for resistive random access memory devices. We also discuss some general characteristics for ideal resistive RAM oxides that could be used in future computational material searches.

  8. WO3-TiO2 monolithic catalysts for high temperature SCR of NO by NH3. Influence of preparation method on structural and physico-chemical properties, activity and durability

    The WO3-TiO2 catalysts with different WO3 loadings prepared by the coprecipitation method were investigated in comparison with those prepared by the conventional impregnation method for the activity and durability in the high temperature SCR of NO by NH3 and the structural and physico-chemical properties which were characterized by BET and XRD measurements, IR, Raman and XPS spectroscopies. The catalyst prepared by coprecipitation, as compared with that prepared by impregnation, was found to exhibit a higher SCR activity at high temperatures and also to possess a larger surface area, higher Broensted acidity and larger monolayer capacity of the support with WO3. Increasing the WO3 loading of the catalysts enhances the SCR activity and simultaneously increases the Broensted acidity. The observed improvement of SCR activity for the catalyst prepared by coprecipitation is mainly attributed to the higher Broensted acidity and the presence of the more highly dispersed WO3 species which is suggested by the larger monolayer capacity of ca. 13 μmol(W)/m2 and no crystalline WO3 on TiO2 detected with XRD at the high WO3 loading up to 40 wt.%. The catalyst with 20 wt.% WO3, as compared with that prepared by impregnation, was found to exhibit a better thermal durability at high temperatures from 550 to 600 C. The better durability is attributed to that the reduction of the surface area and the formation and subsequent growth of crystalline WO3 upon aging are more remarkably inhibited. (author)

  9. Effects of Different Modification on Physicochemical Properties and Granule Structure of Rice Starch%不同改性方法对大米淀粉理化性质及颗粒结构的影响

    张民; 吴娜; 董家美; 王芳

    2013-01-01

    采用压热处理、微波处理、超声波处理等方法对大米淀粉改性,用DSC、布拉班德粘度仪和扫描电镜等仪器测定了大米淀粉理化指标和颗粒结构.研究结果表明,与原淀粉相比,压热处理淀粉的To、Tp、Tm最高(143.61℃、159.82℃、170.30℃);峰值粘度最低(142 BU);抗酶解性最高(13.49%);除超声波处理,其它方法改性的淀粉的溶解度、膨胀能力、凝沉性都有一定程度的升高,淀粉颗粒均已熔融为一体,无完整的颗粒存在.%Rice starch was modified by autoclaving, microwave and ultrasonic methods, respectively. Then its physicochemical properties and granule structure were explored by differential scanning calorimetry (DSC), Brabender amylograph analyzer, scanning electron microscopy (SEM) and other test methods. The results showed that, in comparison with native starch, the autoclaving treated starch showed higher values of To (143.61 ℃), TP (159.82 ℃) and Tm (170.30 ℃) Jiigher anti-enzymatic property (13.49%) and lower peak viscosity (142BU). The solubility, swelling power, retrogradation of autoclaving and microwave modified starches increased. These starch melted blend and showed no complete particles.

  10. Evaluation of the physicochemical properties of structured materials: metallic, polymeric and ceramic, for the treatment of sour gases; Evaluacion de las propiedades fisicoquimicas de materiales estructurados: metalico, polimerico y ceramico, para el tratamiento de gases acidos

    Salazar, A.; Chavez, R. H. [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Olea, O.; Solis, D., E-mail: rosahilda.chavez@inin.gob.mx [Universidad Autonoma del Estado de Mexico, Facultad de Quimica, Cerro de Coatepec s/n, Ciudad Universitaria, 50100 Toluca, Estado de Mexico (Mexico)

    2013-07-01

    in this work the physicochemical properties of three structured materials: metallic, polymeric and ceramic, from Sulzer Brothers Limited brand, are studied in order to removal sour gases, by absorption process, in aqueous solution of Monoethanolamine (Mea), at 30% weight. Mechanical properties, chemical composition, morphology and corrosion resistance were determined, using different characterization techniques, such as: 1) mechanically, according to standard procedures Astm E-384-1990, 2) chemically, by the corrosion resistance in the presence of an electrochemical cell, in aqueous solution of H{sub 2}SO{sub 4}, 1 N by Astm G-5-1999, 3) morphologically by scanning electron microscopy technique, and 4) efficiency of separation, by the gas chromatography technique in order to determine the chemical absorption of CO{sub 2} by Mea. The ceramic material was the hardest with 700 Hk value and tensile strength of 90 MPa, likewise showed resistance to corrosion of 10.28 m py, separation efficiency of 74% CO{sub 2}, at 10 minutes. The metallic material had a hardness of 190 Hk and it was the most resistant of tension, with 831 MPa, and corrosion resistance of 780.4 x 10{sup -6} m py, likewise promoted CO{sub 2} separation efficiency of 90% during the evaluation. The polymeric material presented hardness of 20 Hk and 35 MPa and it was not suffered surface change with electrochemical attack, with 282.4 x 10{sup -6} m py, and separation efficiency of 88%. Therefore the polymer was the most ductile, with smooth surface and greater resistance with H{sub 2}SO{sub 4}. The metal material was more resistant to plastic deformation and more corrugated surface and the second resistance in the presence of acid medium in aqueous solutions. For all the above, the metallic material is recommended by its greater separation in the reduction of acid gases and the polymer due to its greater chemical resistance. (Author)

  11. Adaptive Multi-resolution 3D Hartree-Fock-Bogoliubov Solver for Nuclear Structure

    Pei, Junchen; Harrison, Robert; Nazarewicz, Witold; Shi, Yue; Thornton, Scott

    2014-01-01

    Complex many-body systems, such as triaxial and reflection-asymmetric nuclei, weakly-bound halo states, cluster configurations, nuclear fragments produced in heavy-ion fusion reactions, cold Fermi gases, and pasta phases in neutron star crust, they are all characterized by large sizes and complex topologies, in which many geometrical symmetries characteristic of ground-state configurations are broken. A tool of choice to study such complex forms of matter is an adaptive multi-resolution wavelet analysis. This method has generated much excitement since it provides a common framework linking many diversified methodologies across different fields, including signal processing, data compression, harmonic analysis and operator theory, fractals, and quantum field theory. To describe complex superfluid many-fermion systems, we introduce an adaptive pseudo-spectral method for solving self-consistent equations of nuclear density functional theory in three dimensions, without symmetry restrictions. The new adaptive mult...

  12. On-line identification, flutter testing and adaptive notching of structural parameters for V-22 tiltrotor aircraft

    R K Mehra; P O Arambel; A M Sampath; R K Prasanth; T C Parham

    2000-04-01

    New algorithms and results are presented for flutter testing and adaptive notching of structural modes in V-22 tiltrotor aircraft based on simulated and flight-test data from Bell Helicopter Textron, Inc. (BHTI). For flutter testing and the identification of structural mode frequencies, dampings and mode shapes, time domain state space techniques based on Deterministic Stochastic Realization Algorithms (DSRA) are used to accurately identify multiple modessimultaneously from sine sweep and other multifrequency data, resulting in great savings over the conventional Prony method. Two different techniques for adaptive notching are explored in order to design an Integrated Flight Structural Control (IFSC) system. The first technique is based on on-line identification of structural mode parameters using DSRA algorithm and tuning of a notch filter. The second technique is based on decoupling rigid-body and structural modes of the aircraft by means of a Kalman filter and using rigid-body estimates in the feedback control loop. The difference between the two approaches is that on-line identification and adaptive notching in the first approach are entirely based on the knowledge of structural modes, whereas the Kalman filter design in the second approach is based on the rigid-body dynamic model only.In the first IFSC design, on-line identification is necessary for flight envelope expansion and to adjust the notch filter frequencies and suppress aero-servoelastic instabilities due to changing flight conditionssuch as gross weight, sling loads, and airspeed. It isshown that by tuning the notch filterfrequency to the identified frequency, the phase lag is reduced and the corresponding structural mode is effectively suppressed and stability is maintained. In the second IFSC design using Kalman filter design, the structural modes are again effectively suppressed. Furthermore, the rigid-body estimates are found to be fairly insensitive to both natural frequency and damping factor

  13. Structural self-assembly and avalanchelike dynamics in locally adaptive networks

    Gräwer, Johannes; Modes, Carl D.; Magnasco, Marcelo O.; Katifori, Eleni

    2015-07-01

    Transport networks play a key role across four realms of eukaryotic life: slime molds, fungi, plants, and animals. In addition to the developmental algorithms that build them, many also employ adaptive strategies to respond to stimuli, damage, and other environmental changes. We model these adapting network architectures using a generic dynamical system on weighted graphs and find in simulation that these networks ultimately develop a hierarchical organization of the final weighted architecture accompanied by the formation of a system-spanning backbone. In addition, we find that the long term equilibration dynamics exhibit behavior reminiscent of glassy systems characterized by long periods of slow changes punctuated by bursts of reorganization events.

  14. Integrated Flight/Structural Mode Control for Very Flexible Aircraft Using L1 Adaptive Output Feedback Controller

    Che, Jiaxing; Cao, Chengyu; Gregory, Irene M.

    2012-01-01

    This paper explores application of adaptive control architecture to a light, high-aspect ratio, flexible aircraft configuration that exhibits strong rigid body/flexible mode coupling. Specifically, an L(sub 1) adaptive output feedback controller is developed for a semi-span wind tunnel model capable of motion. The wind tunnel mount allows the semi-span model to translate vertically and pitch at the wing root, resulting in better simulation of an aircraft s rigid body motion. The control objective is to design a pitch control with altitude hold while suppressing body freedom flutter. The controller is an output feedback nominal controller (LQG) augmented by an L(sub 1) adaptive loop. A modification to the L(sub 1) output feedback is proposed to make it more suitable for flexible structures. The new control law relaxes the required bounds on the unmatched uncertainty and allows dependence on the state as well as time, i.e. a more general unmatched nonlinearity. The paper presents controller development and simulated performance responses. Simulation is conducted by using full state flexible wing models derived from test data at 10 different dynamic pressure conditions. An L(sub 1) adaptive output feedback controller is designed for a single test point and is then applied to all the test cases. The simulation results show that the L(sub 1) augmented controller can stabilize and meet the performance requirements for all 10 test conditions ranging from 30 psf to 130 psf dynamic pressure.

  15. Limited Pollen Dispersal Contributes to Population Genetic Structure but Not Local Adaptation in Quercus oleoides Forests of Costa Rica.

    Nicholas John Deacon

    Full Text Available Quercus oleoides Cham. and Schlect., tropical live oak, is a species of conservation importance in its southern range limit of northwestern Costa Rica. It occurs in high-density stands across a fragmented landscape spanning a contrasting elevation and precipitation gradient. We examined genetic diversity and spatial genetic structure in this geographically isolated and genetically distinct population. We characterized population genetic diversity at 11 nuclear microsatellite loci in 260 individuals from 13 sites. We monitored flowering time at 10 sites, and characterized the local environment in order to compare observed spatial genetic structure to hypotheses of isolation-by-distance and isolation-by-environment. Finally, we quantified pollen dispersal distances and tested for local adaptation through a reciprocal transplant experiment in order to experimentally address these hypotheses.High genetic diversity is maintained in the population and the genetic variation is significantly structured among sampled sites. We identified 5 distinct genetic clusters and average pollen dispersal predominately occurred over short distances. Differences among sites in flowering phenology and environmental factors, however, were not strictly associated with genetic differentiation. Growth and survival of upland and lowland progeny in their native and foreign environments was expected to exhibit evidence of local adaptation due to the more extreme dry season in the lowlands. Seedlings planted in the lowland garden experienced much higher mortality than seedlings in the upland garden, but we did not identify evidence for local adaptation.Overall, this study indicates that the Costa Rican Q. oleoides population has a rich population genetic history. Despite environmental heterogeneity and habitat fragmentation, isolation-by-distance and isolation-by-environment alone do not explain spatial genetic structure. These results add to studies of genetic structure by

  16. Enterprise System Adaptation: a Combination of Institutional Structures and Sensemaking Processes

    Svejvig, Per; Jensen, Tina Blegind

    2009-01-01

    In this paper we set out to investigate how an Enterprise System (ES) adaptation in a Scandinavian high-tech organization, SCANDI, can be understood using a combination of institutional and sensemaking theory. Institutional theory is useful in providing an account for the role that the social and...

  17. Influence of the structure branch market on adaptive development of the enterprise

    T.O. Zagornaya

    2012-03-01

    Full Text Available Problem of the study of branch markets influence on development and realization adaptive development strategy of the enterprise is considered in article. The basis of the offered approach forms the development of the alternative directions of the strategic decisions for some industrial enterprises with taking into account their position on the market and features of branch markets functioning.

  18. Strategic Adaptation

    Andersen, Torben Juul

    2015-01-01

    This article provides an overview of theoretical contributions that have influenced the discourse around strategic adaptation including contingency perspectives, strategic fit reasoning, decision structure, information processing, corporate entrepreneurship, and strategy process. The related...... concepts of strategic renewal, dynamic managerial capabilities, dynamic capabilities, and strategic response capabilities are discussed and contextualized against strategic responsiveness. The insights derived from this article are used to outline the contours of a dynamic process of strategic adaptation...

  19. Evolution of genomic structural variation and genomic architecture in the adaptive radiations of African cichlid fishes

    Shaohua eFan

    2014-06-01

    Full Text Available African cichlid fishes are an ideal system for studying explosive rates of speciation and the origin of diversity in adaptive radiation. Within the last few million years, more than 2000 species have evolved in the Great Lakes of East Africa, the largest adaptive radiation in vertebrates. These young species show spectacular diversity in their coloration, morphology and behavior. However, little is known about the genomic basis of this astonishing diversity. Recently, five African cichlid genomes were sequenced, including that of the Nile tilapia (Oreochromis niloticus, a basal and only relatively moderately diversified lineage, and the genomes of four representative endemic species of the adaptive radiations, Neolamprologus brichardi, Astatotilapia burtoni, Metriaclima zebra, and Pundamila nyererei. Using the tilapia genome as the reference genome, we generated a high-resolution genomic variation map, consisting of single nucleotide polymorphisms (SNPs, short insertions and deletions (indels, inversions and deletions. In total, around 18.8, 17.7, 17.0 and 17.0 million SNPs, 2.3, 2.2, 1.4 and 1.9 million indels, 262, 306, 162, and 154 inversions, and 3509, 2705, 2710 and 2634 deletions were inferred to have evolved in the N. brichardi, A. burtoni, P. nyererei and M. zebra respectively. Many of these variations affected the annotated gene regions in the genome. Different patterns of genetic variation were detected during the adaptive radiation of African cichlid fishes. For SNPs, the highest rate of evolution was detected in the common ancestor of N. brichardi, A. burtoni, P. nyererei and M. zebra. However, for the evolution of inversions and deletions, we found that the rates at the terminal taxa are substantially higher than the rates at the ancestral lineages. The high-resolution map provides an ideal opportunity to understand the genomic bases of the adaptive radiation of African cichlid fishes.

  20. Structural Basis for Phosphotyrosine Recognition by the Src Homology-2 Domains of the Adapter Proteins SH2-B and APS

    Hu,J.; Hubbard, S.

    2006-01-01

    SH2-B, APS, and Lnk constitute a family of adapter proteins that modulate signaling by protein tyrosine kinases. These adapters contain an N-terminal dimerization region, a pleckstrin homology domain, and a C-terminal Src homology-2 (SH2) domain. SH2-B is recruited via its SH2 domain to various protein tyrosine kinases, including Janus kinase-2 (Jak2) and the insulin receptor. Here, we present the crystal structure at 2.35 Angstroms resolution of the SH2 domain of SH2-B in complex with a phosphopeptide representing the SH2-B recruitment site in Jak2 (pTyr813). The structure reveals a canonical SH2 domain-phosphopeptide binding mode, but with specific recognition of a glutamate at the +1 position relative to phosphotyrosine, in addition to recognition of a hydrophobic residue at the +3 position. Biochemical studies of SH2-B and APS demonstrate that, although the SH2 domains of these two adapter proteins share 79% sequence identity, the SH2-B SH2 domain binds preferentially to Jak2, whereas the APS SH2 domain has higher affinity for the insulin receptor. This differential specificity is attributable to the difference in the oligomeric states of the two SH2 domains: monomeric for SH2-B and dimeric for APS.

  1. Genetic Diversity and Population Structure in a Legacy Collection of Spring Barley Landraces Adapted to a Wide Range of Climates

    Walther, Alexander; Özkan, Hakan; Graner, Andreas; Kilian, Benjamin

    2014-01-01

    Global environmental change and increasing human population emphasize the urgent need for higher yielding and better adapted crop plants. One strategy to achieve this aim is to exploit the wealth of so called landraces of crop species, representing diverse traditional domesticated populations of locally adapted genotypes. In this study, we investigated a comprehensive set of 1485 spring barley landraces (Lrc1485) adapted to a wide range of climates, which were selected from one of the largest genebanks worldwide. The landraces originated from 5° to 62.5° N and 16° to 71° E. The whole collection was genotyped using 42 SSR markers to assess the genetic diversity and population structure. With an average allelic richness of 5.74 and 372 alleles, Lrc1485 harbours considerably more genetic diversity than the most polymorphic current GWAS panel for barley. Ten major clusters defined most of the population structure based on geographical origin, row type of the ear and caryopsis type – and were assigned to specific climate zones. The legacy core reference set Lrc648 established in this study will provide a long-lasting resource and a very valuable tool for the scientific community. Lrc648 is best suited for multi-environmental field testing to identify candidate genes underlying quantitative traits but also for allele mining approaches. PMID:25541702

  2. Genetic diversity and population structure in a legacy collection of spring barley landraces adapted to a wide range of climates.

    Raj K Pasam

    Full Text Available Global environmental change and increasing human population emphasize the urgent need for higher yielding and better adapted crop plants. One strategy to achieve this aim is to exploit the wealth of so called landraces of crop species, representing diverse traditional domesticated populations of locally adapted genotypes. In this study, we investigated a comprehensive set of 1485 spring barley landraces (Lrc1485 adapted to a wide range of climates, which were selected from one of the largest genebanks worldwide. The landraces originated from 5° to 62.5° N and 16° to 71° E. The whole collection was genotyped using 42 SSR markers to assess the genetic diversity and population structure. With an average allelic richness of 5.74 and 372 alleles, Lrc1485 harbours considerably more genetic diversity than the most polymorphic current GWAS panel for barley. Ten major clusters defined most of the population structure based on geographical origin, row type of the ear and caryopsis type - and were assigned to specific climate zones. The legacy core reference set Lrc648 established in this study will provide a long-lasting resource and a very valuable tool for the scientific community. Lrc648 is best suited for multi-environmental field testing to identify candidate genes underlying quantitative traits but also for allele mining approaches.

  3. PHYSICOCHEMICAL AND STRUCTURAL-PROPERTIES OF THE SURFACES OF PEPTOSTREPTOCOCCUS-MICROS AND STREPTOCOCCUS-MITIS AS COMPARED TO THOSE OF MUTANS STREPTOCOCCI, STREPTOCOCCUS-SANGUIS AND STREPTOCOCCUS-SALIVARIUS

    COWAN, MM; VANDERMEI, HC; ROUXHET, PG; BUSSCHER, HJ

    1992-01-01

    The surface properties of nine Streptococcus mitis and four Peptostreptococcus micros strains from the oral cavity were examined and compared with a large group of oral streptococci. Zeta potential and contact angle measurements were employed to determine physico-chemical cell surface properties. In

  4. Asian International Students at an Australian University: Mapping the Paths between Integrative Motivation, Competence in L2 Communication, Cross-Cultural Adaptation and Persistence with Structural Equation Modelling

    Yu, Baohua

    2013-01-01

    This study examined the interrelationships of integrative motivation, competence in second language (L2) communication, sociocultural adaptation, academic adaptation and persistence of international students at an Australian university. Structural equation modelling demonstrated that the integrative motivation of international students has a…

  5. The crystal structure of Haloferax volcanii proliferating cell nuclear antigen reveals unique surface charge characteristics due to halophilic adaptation

    Morroll Shaun

    2009-08-01

    Full Text Available Abstract Background The high intracellular salt concentration required to maintain a halophilic lifestyle poses challenges to haloarchaeal proteins that must stay soluble, stable and functional in this extreme environment. Proliferating cell nuclear antigen (PCNA is a fundamental protein involved in maintaining genome integrity, with roles in both DNA replication and repair. To investigate the halophilic adaptation of such a key protein we have crystallised and solved the structure of Haloferax volcanii PCNA (HvPCNA to a resolution of 2.0 Å. Results The overall architecture of HvPCNA is very similar to other known PCNAs, which are highly structurally conserved. Three commonly observed adaptations in halophilic proteins are higher surface acidity, bound ions and increased numbers of intermolecular ion pairs (in oligomeric proteins. HvPCNA possesses the former two adaptations but not the latter, despite functioning as a homotrimer. Strikingly, the positive surface charge considered key to PCNA's role as a sliding clamp is dramatically reduced in the halophilic protein. Instead, bound cations within the solvation shell of HvPCNA may permit sliding along negatively charged DNA by reducing electrostatic repulsion effects. Conclusion The extent to which individual proteins adapt to halophilic conditions varies, presumably due to their diverse characteristics and roles within the cell. The number of ion pairs observed in the HvPCNA monomer-monomer interface was unexpectedly low. This may reflect the fact that the trimer is intrinsically stable over a wide range of salt concentrations and therefore additional modifications for trimer maintenance in high salt conditions are not required. Halophilic proteins frequently bind anions and cations and in HvPCNA cation binding may compensate for the remarkable reduction in positive charge in the pore region, to facilitate functional interactions with DNA. In this way, HvPCNA may harness its environment as

  6. Relations between Classroom Goal Structures and Students' Goal Orientations in Mathematics Classes: When Is a Mastery Goal Structure Adaptive?

    Skaalvik, Einar M.; Federici, Roger A.

    2016-01-01

    The purpose of this study was to test possible interactions between mastery and performance goal structures in mathematics classrooms when predicting students' goal orientations. More specifically, we tested if the degree of performance goal structure moderated the associations between mastery goal structure and students' goal orientations.…

  7. From epidemics to information propagation: Striking differences in structurally similar adaptive network models

    Trajanovski, Stojan; Guo, Dongchao; Van Mieghem, Piet

    2015-09-01

    The continuous-time adaptive susceptible-infected-susceptible (ASIS) epidemic model and the adaptive information diffusion (AID) model are two adaptive spreading processes on networks, in which a link in the network changes depending on the infectious state of its end nodes, but in opposite ways: (i) In the ASIS model a link is removed between two nodes if exactly one of the nodes is infected to suppress the epidemic, while a link is created in the AID model to speed up the information diffusion; (ii) a link is created between two susceptible nodes in the ASIS model to strengthen the healthy part of the network, while a link is broken in the AID model due to the lack of interest in informationless nodes. The ASIS and AID models may be considered as first-order models for cascades in real-world networks. While the ASIS model has been exploited in the literature, we show that the AID model is realistic by obtaining a good fit with Facebook data. Contrary to the common belief and intuition for such similar models, we show that the ASIS and AID models exhibit different but not opposite properties. Most remarkably, a unique metastable state always exists in the ASIS model, while there an hourglass-shaped region of instability in the AID model. Moreover, the epidemic threshold is a linear function in the effective link-breaking rate in the AID model, while it is almost constant but noisy in the AID model.

  8. Physicochemical Characteristics of Transferon™ Batches

    Emilio Medina-Rivero

    2016-01-01

    Full Text Available Transferon, a biotherapeutic agent that has been used for the past 2 decades for diseases with an inflammatory component, has been approved by regulatory authorities in Mexico (COFEPRIS for the treatment of patients with herpes infection. The active pharmaceutical ingredient (API of Transferon is based on polydispersion of peptides that have been extracted from lysed human leukocytes by a dialysis process and a subsequent ultrafiltration step to select molecules below 10 kDa. To physicochemically characterize the drug product, we developed chromatographic methods and an SDS-PAGE approach to analyze the composition and the overall variability of Transferon. Reversed-phase chromatographic profiles of peptide populations demonstrated batch-to-batch consistency from 10 representative batches that harbored 4 primary peaks with a relative standard deviation (RSD of less than 7%. Aminogram profiles exhibited 17 proteinogenic amino acids and showed that glycine was the most abundant amino acid, with a relative content of approximately 18%. Further, based on their electrophoretic migration, the peptide populations exhibited a molecular mass of about 10 kDa. Finally, we determined the Transferon fingerprint using a mass spectrometry tool. Because each batch was produced from independent pooled buffy coat samples from healthy donors, supplied by a local blood bank, our results support the consistency of the production of Transferon and reveal its peptide identity with regard to its physicochemical attributes.

  9. Physicochemical Characteristics of Transferon™ Batches

    Pérez-Sánchez, Gilberto; Favari, Liliana; Estrada-Parra, Sergio

    2016-01-01

    Transferon, a biotherapeutic agent that has been used for the past 2 decades for diseases with an inflammatory component, has been approved by regulatory authorities in Mexico (COFEPRIS) for the treatment of patients with herpes infection. The active pharmaceutical ingredient (API) of Transferon is based on polydispersion of peptides that have been extracted from lysed human leukocytes by a dialysis process and a subsequent ultrafiltration step to select molecules below 10 kDa. To physicochemically characterize the drug product, we developed chromatographic methods and an SDS-PAGE approach to analyze the composition and the overall variability of Transferon. Reversed-phase chromatographic profiles of peptide populations demonstrated batch-to-batch consistency from 10 representative batches that harbored 4 primary peaks with a relative standard deviation (RSD) of less than 7%. Aminogram profiles exhibited 17 proteinogenic amino acids and showed that glycine was the most abundant amino acid, with a relative content of approximately 18%. Further, based on their electrophoretic migration, the peptide populations exhibited a molecular mass of about 10 kDa. Finally, we determined the Transferon fingerprint using a mass spectrometry tool. Because each batch was produced from independent pooled buffy coat samples from healthy donors, supplied by a local blood bank, our results support the consistency of the production of Transferon and reveal its peptide identity with regard to its physicochemical attributes. PMID:27525277

  10. Effect of bowelrehabilitative therapy on structural adaptation of remnant small intestine: animal experiment

    Xin Zhou; Yuan Xin Li; Ning Li; Jie Shou Li

    2001-01-01

    GH, vs 320 μm± 16 μm in ENcon,P<0.05) and the mucosa thickness (jejunum740 μm ± 66 μm in EN ± Fib, 705 μm ± 27 μm in EN ±GH, vs 608 μm ± 58 μm in ENcon, ileum 570 μm ±27 μm in EN ± Fib, 560 μm ± 56 μm in EN ± GH, vs480μm ± 40 μm in ENcon, P<0.05) in remnantjejunum and ileum. Glutamine-enriched ENproduced little effect in body mass, plasma IGF-Ⅰ level, and remnant small bowel mucosalstructure. The ENint group had greater bodymass (280g ± 2.2g), plasma IGF-Ⅰ level(1450g@L-1 ± 137g. L 1), and villus height(jejunum 620 μm ± 56 μm, ileum 450 um ± 31 μm)and mucosal thickness (jejunum 800 μm ± 52 μm,ileum 633 μm± 33 μm) than those in ENcon, EN +Gin (jejunum villus height and mucosa thickness450 μm ± 47 μm and 610 μm ± 63 μm, ileum villusheight and mucosa thickness 330 μm ± 39 μm and500 μm± 52 μm), EN + GH groups (P<0.05), andthan those in EN + Fib group although nostatistical significance was attained.CONCLUSION Both dietary fiber and GH whenused separately can enhance the postresectionalsmall bowel structural adaptation. Simultaneoususe of these two gut-trophic factors can producesynergistic effects on small bowel structuraladaptation. Enteral glutamine perfusion isbeneficial in preserving small bowel mucosalstructure during TPN, but has little beneficialeffect during EN.

  11. Blurring the boundaries between actuator and structure: Investigating the use of stereolithography to build adaptive robots

    Mahdavi, S. H.; Hanna, S.

    2004-01-01

    The aim of this work is to investigate whether stereolithographic models, combined with shape memory alloys, can be used to create robotic structures that act both as support structure and actuator. In order to test this, a structural topology was evolved and subsequently, through a deterministic process, optimised to withstand predetermined forces similar to those possibly encountered in a robot. The results show that by using this two stage process, structures can be designed and built that...

  12. A Unifying Framework for Adaptive Radar Detection in Homogeneous Plus Structured Interference— Part I: On the Maximal Invariant Statistic

    Ciuonzo, D.; De Maio, A.; Orlando, D.

    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 deterministic interference. The aforementioned problem corresponds to a generalization of the well-known Generalized Multivariate Analysis of Variance (GMANOVA). In this first part of the work, we formulate the considered problem in canonical form and, after identifying a desirable group of transformations for the considered hypothesis testing, we derive a Maximal Invariant Statistic (MIS) for the problem at hand. Furthermore, we provide the MIS distribution in the form of a stochastic representation. Finally, strong connections to the MIS obtained in the open literature in simpler scenarios are underlined.

  13. Adaptive multi-resolution 3D Hartree-Fock-Bogoliubov solver for nuclear structure

    Pei, J. C.; Fann, G. I.; Harrison, R. J.; Nazarewicz, W.; Shi, Yue; Thornton, S.

    2014-08-01

    Background: Complex many-body systems, such as triaxial and reflection-asymmetric nuclei, weakly bound halo states, cluster configurations, nuclear fragments produced in heavy-ion fusion reactions, cold Fermi gases, and pasta phases in neutron star crust, are all characterized by large sizes and complex topologies in which many geometrical symmetries characteristic of ground-state configurations are broken. A tool of choice to study such complex forms of matter is an adaptive multi-resolution wavelet analysis. This method has generated much excitement since it provides a common framework linking many diversified methodologies across different fields, including signal processing, data compression, harmonic analysis and operator theory, fractals, and quantum field theory. Purpose: To describe complex superfluid many-fermion systems, we introduce an adaptive pseudospectral method for solving self-consistent equations of nuclear density functional theory in three dimensions, without symmetry restrictions. Methods: The numerical method is based on the multi-resolution and computational harmonic analysis techniques with a multi-wavelet basis. The application of state-of-the-art parallel programming techniques include sophisticated object-oriented templates which parse the high-level code into distributed parallel tasks with a multi-thread task queue scheduler for each multi-core node. The internode communications are asynchronous. The algorithm is variational and is capable of solving coupled complex-geometric systems of equations adaptively, with functional and boundary constraints, in a finite spatial domain of very large size, limited by existing parallel computer memory. For smooth functions, user-defined finite precision is guaranteed. Results: The new adaptive multi-resolution Hartree-Fock-Bogoliubov (HFB) solver madness-hfb is benchmarked against a two-dimensional coordinate-space solver hfb-ax that is based on the B-spline technique and a three-dimensional solver

  14. Novel graphene-based nanostructures: physicochemical properties and applications

    The review concerns graphene-based nanostructures including graphene nanoribbons a few nanometres wide, structures functionalized with hydrogen and fluorine atoms as well as pure carbon composites. The physicochemical properties and the chemical engineering methods for their fabrication are considered. Methods for solving problems in modern nanotechnology are discussed. Possible applications of graphene and graphene-based nanostructures in various devices are outlined. The bibliography includes 286 references

  15. New hypotheses derived from the structure of a flaviviral Xrn1-resistant RNA: Conservation, folding, and host adaptation.

    Kieft, Jeffrey S; Rabe, Jennifer L; Chapman, Erich G

    2015-01-01

    Arthropod-borne flaviviruses (FVs) are a growing world-wide health threat whose incidence and range are increasing. The pathogenicity and cytopathicity of these single-stranded RNA viruses are influenced by viral subgenomic non-protein-coding RNAs (sfRNAs) that the viruses produce to high levels during infection. To generate sfRNAs the virus co-opts the action of the abundant cellular exonuclease Xrn1, which is part of the cell's normal RNA turnover machinery. This exploitation of the cellular machinery is enabled by discrete, highly structured, Xrn1-resistant RNA elements (xrRNAs) in the 3'UTR that interact with Xrn1 to halt processive 5' to 3' decay of the viral genomic RNA. We recently solved the crystal structure of a functional xrRNA, revealing a novel fold that provides a mechanistic model for Xrn1 resistance. Continued analysis and interpretation of the structure reveals that the tertiary contacts that knit the xrRNA fold together are shared by a wide variety of arthropod-borne FVs, conferring robust Xrn1 resistance in all tested. However, there is some variability in the structures that correlates with unexplained patterns in the viral 3' UTRs. Finally, examination of these structures and their behavior in the context of viral infection leads to a new hypothesis linking RNA tertiary structure, overall 3' UTR architecture, sfRNA production, and host adaptation. PMID:26399159

  16. Effect of microwave treatment on the physicochemical properties of potato starch granules

    XIE, YANLI; Yan, Mingxia; Yuan, Shasha; SUN, ShuMin; Huo, Quangong

    2013-01-01

    Background The degree of polymerization of amylose starch in potato was so large that the gel was hardness after gelatinization. Therefore, it is one of the most important ways that the microwave treatment was used to change the physicochemical properties of starch gel to make it suitable for the preparation of instant food. Results The effect of microwave treatment on the physicochemical properties including morphology, crystalline structure, molecular weight distribution and rheological pro...

  17. Physicochemical evolution and positive selection of the gymnosperm matK proteins

    Da Cheng Hao; Jun Mu; Shi Lin Chen; Pei Gen Xiao

    2010-04-01

    It is not clear whether matK evolves under Darwinian selection. In this study, the gymnosperm Taxaceae, Cephalotaxaceae and Pinaceae were used to illustrate the physicochemical evolution, molecular adaptation and evolutionary dynamics of gene divergence in matKs. matK sequences were amplified from 27 Taxaceae and 12 Cephalotaxaceae species. matK sequences of 19 Pinaceae species were retrieved from GenBank. The phylogenetic tree was generated using conceptual-translated amino acid sequences. Selective influences were investigated using standard $d_{\\text{N}}/d_{\\text{S}}$ ratio methods and more sensitive techniques investigating the amino acid property changes resulting from nonsynonymous replacements in a phylogenetic context. Analyses revealed the presence of positive selection in matKs (N-terminal region, RT domain and domain X) of Taxaceae and Pinaceae, and found positive destabilizing selection in N-terminal region and RT domain of Cephalotaxaceae matK. Moreover, various amino acid properties were found to be influenced by destabilizing positive selection. Amino acid sites relating to these properties and to different secondary structures were found and have the potential to affect group II intron maturase function. Despite the evolutionary constraint on the rapidly evolving matK, this protein evolves under positive selection in gymnosperm. Several regions of matK have experienced molecular adaptation which fine-tunes maturase performance.

  18. Ventricular structure, function, and mechanics at high altitude: chronic remodeling in Sherpa vs. short-term lowlander adaptation.

    Stembridge, Mike; Ainslie, Philip N; Hughes, Michael G; Stöhr, Eric J; Cotter, James D; Nio, Amanda Q X; Shave, Rob

    2014-08-01

    Short-term, high-altitude (HA) exposure raises pulmonary artery systolic pressure (PASP) and decreases left-ventricular (LV) volumes. However, relatively little is known of the long-term cardiac consequences of prolonged exposure in Sherpa, a highly adapted HA population. To investigate short-term adaptation and potential long-term cardiac remodeling, we studied ventricular structure and function in Sherpa at 5,050 m (n = 11; 31 ± 13 yr; mass 68 ± 10 kg; height 169 ± 6 cm) and lowlanders at sea level (SL) and following 10 ± 3 days at 5,050 m (n = 9; 34 ± 7 yr; mass 82 ± 10 kg; height 177 ± 6 cm) using conventional and speckle-tracking echocardiography. At HA, PASP was higher in Sherpa and lowlanders compared with lowlanders at SL (both P stroke volumes than lowlanders at SL with lower RV systolic strain (P < 0.05) but similar LV systolic mechanics. In contrast to LV systolic mechanics, LV diastolic, untwisting velocity was significantly lower in Sherpa compared with lowlanders at both SL and HA. After partial acclimatization, lowlanders demonstrated no change in the RV end-diastolic area; however, both RV strain and LV end-diastolic volume were reduced. In conclusion, short-term hypoxia induced a reduction in RV systolic function that was also evident in Sherpa following chronic exposure. We propose that this was consequent to a persistently higher PASP. In contrast to the RV, remodeling of LV volumes and normalization of systolic mechanics indicate structural and functional adaptation to HA. However, altered LV diastolic relaxation after chronic hypoxic exposure may reflect differential remodeling of systolic and diastolic LV function. PMID:24876358

  19. Brazilian version of the Structured Interview for Disorders of Extreme Stress - Revised (SIDES-R: adaptation and validation process

    Jessica Camargo

    2013-12-01

    Full Text Available BACKGROUND: Posttraumatic stress disorder (PTSD contemplates the impact of acute traumatic events, but the literature indicates that this is not true for chronic exposure to stress. In this sense, the category disorders of extreme stress not otherwise specified (DESNOS has been proposed to characterize the behavior and cognitive alterations derived from exposure to continuous early life stress. The Structured Interview for Disorders of Extreme Stress - Revised (SIDES-R was developed to investigate and measure DESNOS. Considering the lack of instruments designed to assess DESNOS, especially in Brazil, the aim of this study was to translate, adapt, and validate the contents of SIDES-R to Brazilian Portuguese (SIDES-R-BR. METHOD: The original interview was subjected to translation, back-translation, semantic equivalence and conceptual correspondence analyses by naive and specialized judges, respectively, an acceptability trial, and inter-rater validity analysis. RESULTS: The interview underwent semantic and structural adaptations considering the Brazilian culture. The final version, SIDES-R-BR, showed a mean understanding score of 4.98 on a 5-point verbal rating scale, in addition to a kappa coefficient of 0.853. CONCLUSION: SIDES-R-BR may be a useful tool in the investigation of DESNOS and contributes a valuable input to clinical research in Brazil. The availability of the instrument allows to test symptoms with adequate reliability, as verified by the kappa coefficient and translation steps.

  20. Coherent structure extraction in turbulent channel flow using boundary adapted wavelets

    Sakurai, Teluo; Schneider, Kai; Farge, Marie; Morishita, Koji; Ishihara, Takashi

    2016-01-01

    We present a construction of isotropic boundary adapted wavelets, which are orthogonal and yield a multi-resolution analysis. We analyze direct numerical simulation data of turbulent channel flow computed at a friction Reynolds number of 395, and investigate the role of coherent vorticity. Thresholding of the vorticity wavelet coefficients allows to split the flow into two parts, coherent and incoherent vorticity. The coherent vorticity is reconstructed from their few intense wavelet coefficients. The statistics of the coherent part, i.e., energy and enstrophy spectra, are close to the statistics of the total flow, and moreover, the nonlinear energy budgets are very well preserved. The remaining incoherent part, represented by the large majority of the weak wavelet coefficients, corresponds to a structureless, i.e., noise-like, background flow whose energy is equidistributed.

  1. Spatio-Temporal Video Object Segmentation via Scale-Adaptive 3D Structure Tensor

    Hai-Yun Wang

    2004-06-01

    Full Text Available To address multiple motions and deformable objects' motions encountered in existing region-based approaches, an automatic video object (VO segmentation methodology is proposed in this paper by exploiting the duality of image segmentation and motion estimation such that spatial and temporal information could assist each other to jointly yield much improved segmentation results. The key novelties of our method are (1 scale-adaptive tensor computation, (2 spatial-constrained motion mask generation without invoking dense motion-field computation, (3 rigidity analysis, (4 motion mask generation and selection, and (5 motion-constrained spatial region merging. Experimental results demonstrate that these novelties jointly contribute much more accurate VO segmentation both in spatial and temporal domains.

  2. Adaptive Smith-Waterman residue match seeding for protein structural alignment.

    Topham, Christopher M; Rouquier, Mickaël; Tarrat, Nathalie; André, Isabelle

    2013-10-01

    The POLYFIT rigid-body algorithm for automated global pairwise and multiple protein structural alignment is presented. Smith-Waterman local alignment is used to establish a set of seed equivalences that are extended using Needleman-Wunsch dynamic programming techniques. Structural and functional interaction constraints provided by evolution are encoded as one-dimensional residue physical environment strings for alignment of highly structurally overlapped protein pairs. Local structure alignment of more distantly related pairs is carried out using rigid-body conformational matching of 15-residue fragments, with allowance made for less stringent conformational matching of metal-ion and small molecule ligand-contact, disulphide bridge, and cis-peptide correspondences. Protein structural plasticity is accommodated through the stepped adjustment of a single empirical distance parameter value in the calculation of the Smith-Waterman dynamic programming matrix. Structural overlap is used both as a measure of similarity and to assess alignment quality. Pairwise alignment accuracy has been benchmarked against that of 10 widely used aligners on the Sippl and Wiederstein set of difficult pairwise structure alignment problems, and more extensively against that of Matt, SALIGN, and MUSTANG in pairwise and multiple structural alignments of protein domains with low shared sequence identity in the SCOP-ASTRAL 40% compendium. The results demonstrate the advantages of POLYFIT over other aligners in the efficient and robust identification of matching seed residue positions in distantly related protein targets and in the generation of longer structurally overlapped alignment lengths. Superposition-based application areas include comparative modeling and protein and ligand design. POLYFIT is available on the Web server at http://polyfit.insa-toulouse.fr. PMID:23720362

  3. Granule Structure and Physico-chemical Properties of Light Speckled Kidney Bean Starch%奶白花芸豆淀粉颗粒结构及理化特性研究

    韩春然; 姚珊珊; 许鑫

    2012-01-01

    研究奶白花芸豆淀粉的颗粒结构及基本理化性质。结果表明:奶白花芸豆中直链淀粉含量较高,为37.1%;芸豆淀粉-碘的最大吸收光谱在波长617nm附近;芸豆淀粉颗粒较大的呈现卵形,颗粒大小分布较均匀。X射线衍射分析表明,该芸豆淀粉属于A型结晶结构;芸豆淀粉的粒度均呈光滑单峰型,分布曲线为正态分布,高峰出现在21.12~23.51μm处。芸豆淀粉颗粒偏光十字极其明显。芸豆淀粉糊凝沉性质表明该淀粉容易老化;芸豆淀粉糊的透光率在0~12h内没有显著变化,12~24h内透明度呈显著下降趋势,24~48h内没有显著变化。在质量浓度为2g/100mL时,析水率最高,冻融稳定性最差;差示扫描量热仪(DSC)分析结果表明,起始糊化温度为61.3℃,2个糊化峰值温度分别为73℃和74.6℃,糊化结束温度为83.4℃,糊化所需焓值为50.55J/g。淀粉糊质量浓度对其黏度具有显著影响,4g/100mL为该芸豆淀粉成糊临界质量浓度。%The granule structure and basic physico-chemical properties of starch from light speckled kidney bean grown in Heilongjiang province were studied. The amylose content of light speckled kidney bean starch was 37.1%. The starch showed maximum absorbance at 617 nm after complexing with iodine. The starch granules were large and oval in shape and showed an uniform size distribution. The crystal structure of the starch, as indicated by X-ray analysis, belonged to type A. The granularity distribution showed a single smooth peak at 21.12--23.51/a m and was in a normal manner. The birefringence cross of starch granules was very obvious and the starch revealed an obvious retrogradation property. In addition, the transparency of the starch gel had no significant change during 0-- 12 h and 24--48 h, while a significant change was observed during 12-- 24 h. The freeze-thaw stability was the weakest at the concentration of 2%. DSC results showed that the original pasting

  4. 水葫芦水热碳化过程中焦炭物化结构演变特性%Forming property of water hyacinth hydro-char physicochemical structure during hydrothermal carbonation

    高英; 袁巧霞; 陈汉平; 王贤华

    2015-01-01

    以水葫芦为原料,利用高温高压反应釜对240℃、停留时间0.5~24.0 h下水热炭物化结构的演变特性进行分析.研究发现:不同停留时间下焦炭的产率及O/C和H/C原子比的范围分别为22.17%~31.67%,0.19~0.45和0.94~1.51,焦炭的热值范围为16.83~20.63 M J/kg .通过对焦炭进行分析测试,探讨水热炭的生成机理以及炭微球的形成机制,结果表明:4.0h后延长停留时间对焦炭的化学特性没有明显的影响;但是随着时间的进一步延长,水热炭却表现出较好的结构特性,可以观察到焦炭表面有大量微球的生成,具有典型的核壳结构,炭微球的表面含有大量的活性含氧官能团,内部则为低活性的含氧官能团;水热炭比表面积随着时间的延长先增大后减小.%Hydrothermal carbonization of water hyacinth was conducted in an autoclave from 0 .5 h to 24 .0 h at 240 ℃ ,the physicochemical characteristics of water hyacinth hydro‐char was investigated . T he results show that hydro‐char yield ,oxygen/carbon ratio ,and hydrogen/carbon ratio in all hydro‐char products are 22 .17% to 31 .67% ,0 .19 to 0 .45 ,and 0 .94 to 1 .51 ,respectively ,and higher heat‐ing value of hydro‐char products is 16 .83 to 20 .63 MJ/kg .To further investigate the hydrothermal formation mechanism and carbon microspheres formation mechanism ,it is indicated that there′s no significant change in the chemical properties of hydro‐char after 4 .0 h ,but with time increasing ,the hydro‐char show better structural characteristics . The surface generates a large number of micro‐spheres with a typical core‐shell structure and the surface of carbon microspheres contains large a‐mounts of reactive oxygen‐containing functional groups ,compares with low activity of the internal ox‐ygen‐containing functional groups ,and specific surface area increases first ,and then decreases

  5. EDITORIAL: Adaptive and active materials: Selected papers from the ASME 2010 Conference on Smart Materials, Adaptive Structures and Intelligent Systems (SMASIS 10) (Philadelphia, PA, USA, 28 September-1 October 2010) Adaptive and active materials: Selected papers from the ASME 2010 Conference on Smart Materials, Adaptive Structures and Intelligent Systems (SMASIS 10) (Philadelphia, PA, USA, 28 September-1 October 2010)

    Brei, Diann

    2011-09-01

    The third annual meeting of the AMSE/AIAA Smart Materials, Adaptive Structures and Intelligent Systems Conference (SMASIS) took place in the heart of historic Philadelphia's cultural district, and included a pioneer banquet in the National Constitutional Center. The applications emphasis of the 2010 conference was reflected in keynote talks by Dr Alan Taub, vice president of General Motors global research and development, 'Smart materials in the automotive industry'; Dr Charles R Farrar, engineering institute leader at Los Alamos National Laboratory, 'Future directions for structural health monitoring of civil engineering infrastructure'; and Professor Christopher S Lynch of the University of California Los Angeles, 'Ferroelectric materials and their applications'. The SMASIS conference was divided into six technical symposia each of which included basic research, applied technological design and development, and industrial and governmental integrated system and application demonstrations. The six symposia were: SYMP 1 Multifunctional Materials; SYMP 2 Active Materials, Mechanics and Behavior; SYMP 3 Modeling, Simulation and Control; SYMP 4 Enabling Technologies and Integrated System Design; SYMP 5 Structural Health Monitoring/NDE; and SYMP 6 Bio-inspired Smart Materials and Structures. In addition, the conference introduced a new student and young professional development symposium. Authors of papers in the materials areas (symposia 1, 2 and 6) were invited to write a full journal article on their presentation topic for publication in this special issue of Smart Materials and Structures. This set of papers demonstrates the exceptional quality and originality of the conference presentations. We are appreciative of their efforts in producing this collection of highly relevant articles on smart materials.

  6. Physicochemical studies of silicoaluminophosphate microporous materials

    Crystalline microporous molecular sieve materials such as alumino phosphates (AlPO/sub 4/-n) and silicoaluminophosphates (SAPO-n) are gaining tremendous importance for petroleum refining and petrochemical industries due to its fascinating catalytic and ion exchange properties. Some selected silicoaluminophosphate crystalline microporous materials topologically related to the zeolites chabazite (SAPO-34), faujasite (SAPO-37) structure and to the novel structure Pentasil-types ( SAPO-5 and SAPO-11) have been synthesized hydrothermally at an autogenous pressure and different temperatures in PTFE-lined stainless steel digestion bomb. The physico-chemical characteristics of as-synthesized and calcined products were studied using different analytical techniques such as the differential thermal analysis (DTA), thermogravimetric (TG), differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and x-ray diffraction (XRD). Pore size was measured by the sorption of hydrocarbon molecules (n-hexane, neopentane). The surface area, porosity, particle size and particle size distribution were resolved using BET volumetric system and laser particle size analyzer. Crystallinity and unit cell parameters of these materials were also ascertained. (author)

  7. Integrated and Distributed Adaptive Metacomposites for vibroacoustic control of Aerospace Structures

    Collet, Manuel; Ouisse, Morvan; Tateo, Flaviano; Ichchou, Mohamed Najib

    2013-01-01

    Research activities in smart materials and structures represent a significant potential for technological innovation in mechanics and electronics. The necessity of controlling vibroacoustic behavior of industrial systems motivates a broad research effort for introducing active or passive technologies to control noise and vibrations. New processes are now available which allow active transducers and their driving electronics to be directly integrated into otherwise passive structures. This new...

  8. Closed-Loop Input Shaping Control of Vibration in Flexible Structures via Adaptive Sliding Mode Control

    Ming-Chang Pai

    2012-01-01

    Input shaping technique is widely used in reducing or eliminating residual vibration of flexible structures. The exact elimination of the residual vibration via input shaping technique depends on the amplitudes and instants of impulse application. However, systems always have parameter uncertainties which can lead to performance degradation. In this paper, a closed-loop input shaping control scheme is developed for uncertain flexible structures. The algorithm is based on input shaping control...

  9. Active membrane having uniform physico-chemically functionalized ion channels

    Gerald, II, Rex E; Ruscic, Katarina J; Sears, Devin N; Smith, Luis J; Klingler, Robert J; Rathke, Jerome W

    2012-09-24

    The present invention relates to a physicochemically-active porous membrane for electrochemical cells that purports dual functions: an electronic insulator (separator) and a unidirectional ion-transporter (electrolyte). The electrochemical cell membrane is activated for the transport of ions by contiguous ion coordination sites on the interior two-dimensional surfaces of the trans-membrane unidirectional pores. One dimension of the pore surface has a macroscopic length (1 nm-1000 .mu.m) and is directed parallel to the direction of an electric field, which is produced between the cathode and the anode electrodes of an electrochemical cell. The membrane material is designed to have physicochemical interaction with ions. Control of the extent of the interactions between the ions and the interior pore walls of the membrane and other materials, chemicals, or structures contained within the pores provides adjustability of the ionic conductivity of the membrane.

  10. Topology optimization of adaptive fluid-actuated cellular structures with arbitrary polygonal motor cells

    Lv, Jun; Tang, Liang; Li, Wenbo; Liu, Lei; Zhang, Hongwu

    2016-05-01

    This paper mainly focuses on the fast and efficient design method for plant bioinspired fluidic cellular materials and structures composed of polygonal motor cells. Here we developed a novel structural optimization method with arbitrary polygonal coarse-grid elements based on multiscale finite element frameworks. The fluidic cellular structures are meshed with irregular polygonal coarse-grid elements according to their natural size and the shape of the imbedded motor cells. The multiscale base functions of solid displacement and hydraulic pressure are then constructed to bring the small-scale information of the irregular motor cells to the large-scale simulations on the polygonal coarse-grid elements. On this basis, a new topology optimization method based on the resulting polygonal coarse-grid elements is proposed to determine the optimal distributions or number of motor cells in the smart cellular structures. Three types of optimization problems are solved according to the usages of the fluidic cellular structures. Firstly, the proposed optimization method is utilized to minimize the system compliance of the load-bearing fluidic cellular structures. Second, the method is further extended to design biomimetic compliant actuators of the fluidic cellular materials due to the fact that non-uniform volume expansions of fluid in the cells can induce elastic action. Third, the optimization problem focuses on the weight minimization of the cellular structure under the constraints for the compliance of the whole system. Several representative examples are investigated to validate the effectiveness of the proposed polygon-based topology optimization method of the smart materials.

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

    Hurley Thomas D; Nan Fa-Jun; Huang Qing-Qing; Xie Sheng-Xue; Ma Ze-Qiang; Ye Qi-Zhuang

    2007-01-01

    Abstract 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 ...

  12. The ever changing moods of calmodulin: how structural plasticity entails transductional adaptability.

    Villarroel, Alvaro; Taglialatela, Maurizio; Bernardo-Seisdedos, Ganeko; Alaimo, Alessandro; Agirre, Jon; Alberdi, Araitz; Gomis-Perez, Carolina; Soldovieri, Maria Virginia; Ambrosino, Paolo; Malo, Covadonga; Areso, Pilar

    2014-07-29

    The exceptional versatility of calmodulin (CaM) three-dimensional arrangement is reflected in the growing number of structural models of CaM/protein complexes currently available in the Protein Data Bank (PDB) database, revealing a great diversity of conformations, domain organization, and structural responses to Ca(2+). Understanding CaM binding is complicated by the diversity of target proteins sequences. Data mining of the structures shows that one face of each of the eight CaM helices can contribute to binding, with little overall difference between the Ca(2+) loaded N- and C-lobes and a clear prevalence of the C-lobe low Ca(2+) conditions. The structures reveal a remarkable variety of configurations where CaM binds its targets in a preferred orientation that can be reversed and where CaM rotates upon Ca(2+) binding, suggesting a highly dynamic metastable relation between CaM and its targets. Recent advances in structure-function studies and the discovery of CaM mutations being responsible for human diseases, besides expanding the role of CaM in human pathophysiology, are opening new exciting avenues for the understanding of the how CaM decodes Ca(2+)-dependent and Ca(2+)-independent signals. PMID:24857860

  13. Alternative Adaptive Filter Structures for Improved Radio Frequency Interference Cancellation in Radio Astronomy

    Mitchell, D A; Sault, R J

    2010-01-01

    In radio astronomy, reference signals from auxiliary antennas that receive only the radio frequency interference (RFI) can be modified to model the RFI environment at the astronomy receivers. The RFI can then be canceled from the astronomy signal paths. However, astronomers typically only require signal statistics. If the RFI statistics are changing slowly, the cancellation can be applied to the signal correlations at a much lower rate than is required for standard adaptive filters. In this paper we describe five canceler setups; precorrelation and postcorrelation cancelers that use one or two reference signals in different ways. The theoretical residual RFI and added noise levels are examined and are demonstrated using microwave television RFI at the Australia Telescope Compact Array. The RFI is attenuated to below the system noise, a reduction of at least 20 dB. While dual-reference cancelers add more reference noise than single-reference cancelers, this noise is zero-mean and only adds to the system noise,...

  14. Mapping the Clumpy Structures within Submillimeter Galaxies using Laser-Guide Star Adaptive Optics Spectroscopy

    Menéndez-Delmestre, Karín; Swinbank, Mark; Smail, Ian; Ivison, Rob J; Chapman, Scott C; Gonçalves, Thiago S

    2013-01-01

    We present the first integral-field spectroscopic observations of high-redshift submillimeter-selected galaxies (SMGs) using Laser Guide Star Adaptive Optics (LGS-AO). We target H-alpha emission of three SMGs at redshifts z~1.4-2.4 with the OH-Suppressing Infrared Imaging Spectrograph (OSIRIS) on Keck. The spatially-resolved spectroscopy of these galaxies reveals unresolved broad H-alpha line regions (FWHM>1000 km/s) likely associated with an AGN and regions of diffuse star formation traced by narrow-line H-alpha emission (FWHM<500 km/s) dominated by multiple Halpha-bright stellar clumps, each contributing 1-30% of the total clump-integrated H-alpha emission. We find that these SMGs host high star-formation rate surface densities, similar to local extreme sources, such as circumnuclear starbursts and luminous infrared galaxies. However, in contrast to these local environments, SMGs appear to be undergoing such intense activity on significantly larger spatial scales as revealed by extended H-alpha emission ...

  15. Structural insight into DFMO resistant ornithine decarboxylase from Entamoeba histolytica: an inkling to adaptive evolution.

    Preeti

    Full Text Available BACKGROUND: Polyamine biosynthetic pathway is a validated therapeutic target for large number of infectious diseases including cancer, giardiasis and African sleeping sickness, etc. α-Difluoromethylornithine (DFMO, a potent drug used for the treatment of African sleeping sickness is an irreversible inhibitor of ornithine decarboxylase (ODC, the first rate limiting enzyme of polyamine biosynthesis. The enzyme ODC of E. histolytica (EhODC has been reported to exhibit resistance towards DFMO. METHODOLOGY/PRINCIPAL FINDING: The basis for insensitivity towards DFMO was investigated by structural analysis of EhODC and conformational modifications at the active site. Here, we report cloning, purification and crystal structure determination of C-terminal truncated Entamoeba histolytica ornithine decarboxylase (EhODCΔ15. Structure was determined by molecular replacement method and refined to 2.8 Å resolution. The orthorhombic crystal exhibits P2(12(12(1 symmetry with unit cell parameters a = 76.66, b = 119.28, c = 179.28 Å. Functional as well as evolutionary relations of EhODC with other ODC homologs were predicted on the basis of sequence analysis, phylogeny and structure. CONCLUSIONS/SIGNIFICANCE: We determined the tetrameric crystal structure of EhODCΔ15, which exists as a dimer in solution. Insensitivity towards DFMO is due to substitution of key substrate binding residues in active site pocket. Additionally, a few more substitutions similar to antizyme inhibitor (AZI, a non-functional homologue of ODCs, were identified in the active site. Here, we establish the fact that EhODC sequence has conserved PLP binding residues; in contrast few substrate binding residues are mutated similar to AZI. Further sequence analysis and structural studies revealed that EhODC may represent as an evolutionary bridge between active decarboxylase and inactive AZI.

  16. Structural studies of a cold-adapted dimeric β-D-galactosidase from Paracoccus sp. 32d.

    Rutkiewicz-Krotewicz, Maria; Pietrzyk-Brzezinska, Agnieszka J; Sekula, Bartosz; Cieśliński, Hubert; Wierzbicka-Woś, Anna; Kur, Józef; Bujacz, Anna

    2016-09-01

    The crystal structure of a novel dimeric β-D-galactosidase from Paracoccus sp. 32d (ParβDG) was solved in space group P212121 at a resolution of 2.4 Å by molecular replacement with multiple models using the BALBES software. This enzyme belongs to glycoside hydrolase family 2 (GH2), similar to the tetrameric and hexameric β-D-galactosidases from Escherichia coli and Arthrobacter sp. C2-2, respectively. It is the second known structure of a cold-active GH2 β-galactosidase, and the first in the form of a functional dimer, which is also present in the asymmetric unit. Cold-adapted β-D-galactosidases have been the focus of extensive research owing to their utility in a variety of industrial technologies. One of their most appealing applications is in the hydrolysis of lactose, which not only results in the production of lactose-free dairy, but also eliminates the `sandy effect' and increases the sweetness of the product, thus enhancing its quality. The determined crystal structure represents the five-domain architecture of the enzyme, with its active site located in close vicinity to the dimer interface. To identify the amino-acid residues involved in the catalytic reaction and to obtain a better understanding of the mechanism of action of this atypical β-D-galactosidase, the crystal structure in complex with galactose (ParβDG-Gal) was also determined. The catalytic site of the enzyme is created by amino-acid residues from the central domain 3 and from domain 4 of an adjacent monomer. The crystal structure of this dimeric β-D-galactosidase reveals significant differences in comparison to other β-galactosidases. The largest difference is in the fifth domain, named Bgal_windup domain 5 in ParβDG, which contributes to stabilization of the functional dimer. The location of this domain 5, which is unique in size and structure, may be one of the factors responsible for the creation of a functional dimer and cold-adaptation of this enzyme. PMID:27599737

  17. Genetic structure and ecogeographical adaptation in wild barley (Hordeum chilense Roemer et Schultes as revealed by microsatellite markers

    Sourdille Pierre

    2010-11-01

    Full Text Available Abstract Background Multi-allelic microsatellite markers have become the markers of choice for the determination of genetic structure in plants. Synteny across cereals has allowed the cross-species and cross-genera transferability of SSR markers, which constitute a valuable and cost-effective tool for the genetic analysis and marker-assisted introgression of wild related species. Hordeum chilense is one of the wild relatives with a high potential for cereal breeding, due to its high crossability (both interspecies and intergenera and polymorphism for adaptation traits. In order to analyze the genetic structure and ecogeographical adaptation of this wild species, it is necessary to increase the number of polymorphic markers currently available for the species. In this work, the possibility of using syntenic wheat SSRs as a new source of markers for this purpose has been explored. Results From the 98 wheat EST-SSR markers tested for transferability and polymorphism in the wild barley genome, 53 primer pairs (54.0% gave cross-species transferability and 20 primer pairs (20.4% showed polymorphism. The latter were used for further analysis in the H. chilense germplasm. The H. chilense-Triticum aestivum addition lines were used to test the chromosomal location of the new polymorphic microsatellite markers. The genetic structure and diversity was investigated in a collection of 94 H. chilense accessions, using a set of 49 SSR markers distributed across the seven chromosomes. Microsatellite markers showed a total of 351 alleles over all loci. The number of alleles per locus ranged from two to 27, with a mean of 7.2 alleles per locus and a mean Polymorphic Information Content (PIC of 0.5. Conclusions According to the results, the germplasm can be divided into two groups, with morphological and ecophysiological characteristics being key determinants of the population structure. Geographic and ecological structuring was also revealed in the analyzed

  18. Adaptive processing of thin structures to augment segmentation of dual-channel structural MRI of the human brain

    Withers, James

    2010-01-01

    This thesis presents a method for the segmentation of dual-channel structural magnetic resonance imaging (MRI) volumes of the human brain into four tissue classes. The state-of-the-art FSL FAST segmentation software (Zhang et al., 2001) is in widespread clinical use, and so it is considered a benchmark. A significant proportion of FAST’s errors has been shown to be localised to cortical sulci and blood vessels; this issue has driven the developments in this thesis, rather than ...

  19. The methods and computer structures for adaptive Fourier descriptive image analysis

    V.Perzhu; A. Gurau

    1997-01-01

    New architectures of image processing computer systems, based on the algorithms of Fourier - descriptive (FD) analysis have been developed. A new computing processes organisation method on the basis of FD image features has been proposed. The structures of two problem-oriented optical-electronic computer systems have been developed. The estimation of time expenditures in the systems have been carried out.

  20. Applying Adaptive Swarm Intelligence Technology with Structuration in Web-Based Collaborative Learning

    Huang, Yueh-Min; Liu, Chien-Hung

    2009-01-01

    One of the key challenges in the promotion of web-based learning is the development of effective collaborative learning environments. We posit that the structuration process strongly influences the effectiveness of technology used in web-based collaborative learning activities. In this paper, we propose an ant swarm collaborative learning (ASCL)…

  1. Conception et exploitation d'une structure active pour une aile laminaire adaptative experimentale

    Coutu, Daniel

    This doctoral research contributed to the success of the project CRIAQ 7.1, demonstrating the capability of a morphing laminar wing to reduce fuel consumption. Respectively, this thesis shows the design of the experimental wing and its operation in a subsonic wind tunnel (Mach numbers of 0.2 to 0.3 with angles of attack between -1 and 2°). First of all, the morphing wing is formed of a composite laminate linked to an actuation system to build an active structure capable of modifying the wing upper surface geometry. The design was performed using a new developed methodology to solve aero-structural problems. Using ANSYS software, the finite elements method was applied to model the different possible active structure configurations Aerodynamic loads applied over the active structure as well as targeted morphed geometries have been provided by the Ecole Polytechnique team. Next, laminar flow enhancements allowed by each active structure configuration we' re evaluated using the aerodynamic solver XFoil 6.96. A best trade-off between aerodynamic performance and energy needed for wing morphing was found using a multi-objective optimization technique. Among the retained stable configurations, a 4-ply composite laminated shell driven by 2 actuation lines was retained. Thereafter, the research effort focused on the exploitation of the morphing capabilities of the experimental wing over each given set of flow conditions. Therefore, once the prototype was built, the structural model was refined, calibrated and coupled with the aerodynamic solver to accurately predict the aero-structural behavior in the wind tunnel. Optimal morphing wing shapes were numerically calculated using a generalized pattern search algorithm and a local search routine to refine the solution. In the wind tunnel, this open-loop control approach allowed an average 25% laminar flow regime extension over the wing prototype upper surface. Consequently, an average 18.5% profile drag reduction was measured by

  2. Spatially adaptive stochastic methods for fluid–structure interactions subject to thermal fluctuations in domains with complex geometries

    We develop stochastic mixed finite element methods for spatially adaptive simulations of fluid–structure interactions when subject to thermal fluctuations. To account for thermal fluctuations, we introduce a discrete fluctuation–dissipation balance condition to develop compatible stochastic driving fields for our discretization. We perform analysis that shows our condition is sufficient to ensure results consistent with statistical mechanics. We show the Gibbs–Boltzmann distribution is invariant under the stochastic dynamics of the semi-discretization. To generate efficiently the required stochastic driving fields, we develop a Gibbs sampler based on iterative methods and multigrid to generate fields with O(N) computational complexity. Our stochastic methods provide an alternative to uniform discretizations on periodic domains that rely on Fast Fourier Transforms. To demonstrate in practice our stochastic computational methods, we investigate within channel geometries having internal obstacles and no-slip walls how the mobility/diffusivity of particles depends on location. Our methods extend the applicability of fluctuating hydrodynamic approaches by allowing for spatially adaptive resolution of the mechanics and for domains that have complex geometries relevant in many applications

  3. Adaptability and selectivity of human peroxisome proliferator-activated receptor (PPAR) pan agonists revealed from crystal structures

    The structures of the ligand-binding domains (LBDs) of human peroxisome proliferator-activated receptors (PPARα, PPARγ and PPARδ) in complexes with a pan agonist, an α/δ dual agonist and a PPARδ-specific agonist were determined. The results explain how each ligand is recognized by the PPAR LBDs at an atomic level. Peroxisome proliferator-activated receptors (PPARs) belong to the nuclear hormone receptor family, which is defined as transcriptional factors that are activated by the binding of ligands to their ligand-binding domains (LBDs). Although the three PPAR subtypes display different tissue distribution patterns and distinct pharmacological profiles, they all are essentially related to fatty-acid and glucose metabolism. Since the PPARs share similar three-dimensional structures within the LBDs, synthetic ligands which simultaneously activate two or all of the PPARs could be potent candidates in terms of drugs for the treatment of abnormal metabolic homeostasis. The structures of several PPAR LBDs were determined in complex with synthetic ligands, derivatives of 3-(4-alkoxyphenyl)propanoic acid, which exhibit unique agonistic activities. The PPARα and PPARγ LBDs were complexed with the same pan agonist, TIPP-703, which activates all three PPARs and their crystal structures were determined. The two LBD–ligand complex structures revealed how the pan agonist is adapted to the similar, but significantly different, ligand-binding pockets of the PPARs. The structures of the PPARδ LBD in complex with an α/δ-selective ligand, TIPP-401, and with a related δ-specific ligand, TIPP-204, were also determined. The comparison between the two PPARδ complexes revealed how each ligand exhibits either a ‘dual selective’ or ‘single specific’ binding mode

  4. Adaptation of the structured clinical interview for DSM-IV disorder for assessing depression in women during pregnancy and postpartum across countries and cultures

    Hayes, S; Figueiredo, Bárbara; Gorman, L.L; O'Hara, M. W.; Jacquemain, F.; Kammerer, M. H.; Klier, C M; Rosi, S.; Seneviratne, G.; Sutter-Dallay, A.-L.; TCS-PND Group

    2004-01-01

    Background: To date, no study has used standardised diagnostic assessment procedures to determine wether rates of perinatal depression vary across cultures. Aims:To adapt the Structured Clinical Interview for DSM IV Disorders (SCID) for assessing depression and other non-psychotic psychiatric illness perinatally and to pilot the instrument in different centres and cultures. Method: Assessments using the adapted SCID and the Edinburgh Postnatal Depression Scale were conducte...

  5. Study of new structures adapted to gas-graphite and gas-heavy water reactors

    The experience acquired as a result of the operation of the Marcoule reactors and of the construction and start-up of the E.D.F. reactors on the one hand, and the conclusions of research and tests carried out out-of-pile on the other hand, lead to a considerable change in the general design of reactors of the gas-graphite type. The main modifications envisaged are analysed in the paper. The adoption of an annular fuel element and of a down-current cooling will make it possible to increase considerably the specific power and the power output of each channel; as a result there will be a considerable reduction in the number of the channels and a corresponding increase in the size of the unit cell. The graphite stack will have to be adapted to there new conditions. For security reasons, the use of prestressed concrete for the construction of the reactor vessel is becoming more widespread; they could lead to the exchangers and the fuel-handling apparatus becoming integrated inside the vessel (the so-called 'attic' device). A full-size mode) of this attic has been built at Saclay with the participation of EURATOM; the operational results obtained are presented as well as a new original design for the control rods. As for as the gas-heavy-water system is concerned, the research is carried out on two points of design; the first, which retains the use of horizontal pressure tubes, takes into account the experience acquired during the construction of the EL 4 reactor of which it will constitute an extrapolation; the second, arising from the research carried out on the gas-graphite system, will use a pre-stressed concrete vessel for holding the pressure, the moderator being almost at the same pressure as the cooling fluid and the fuel being placed in vertical channels. The relative merits of these two variants are analysed in the present paper. (authors)

  6. The population genomic landscape of human genetic structure, admixture history and local adaptation in Peninsular Malaysia.

    Deng, Lian; Hoh, Boon Peng; Lu, Dongsheng; Fu, Ruiqing; Phipps, Maude E; Li, Shilin; Nur-Shafawati, Ab Rajab; Hatin, Wan Isa; Ismail, Endom; Mokhtar, Siti Shuhada; Jin, Li; Zilfalil, Bin Alwi; Marshall, Christian R; Scherer, Stephen W; Al-Mulla, Fahd; Xu, Shuhua

    2014-09-01

    Peninsular Malaysia is a strategic region which might have played an important role in the initial peopling and subsequent human migrations in Asia. However, the genetic diversity and history of human populations--especially indigenous populations--inhabiting this area remain poorly understood. Here, we conducted a genome-wide study using over 900,000 single nucleotide polymorphisms (SNPs) in four major Malaysian ethnic groups (MEGs; Malay, Proto-Malay, Senoi and Negrito), and made comparisons of 17 world-wide populations. Our data revealed that Peninsular Malaysia has greater genetic diversity corresponding to its role as a contact zone of both early and recent human migrations in Asia. However, each single Orang Asli (indigenous) group was less diverse with a smaller effective population size (N(e)) than a European or an East Asian population, indicating a substantial isolation of some duration for these groups. All four MEGs were genetically more similar to Asian populations than to other continental groups, and the divergence time between MEGs and East Asian populations (12,000--6,000 years ago) was also much shorter than that between East Asians and Europeans. Thus, Malaysian Orang Asli groups, despite their significantly different features, may share a common origin with the other Asian groups. Nevertheless, we identified traces of recent gene flow from non-Asians to MEGs. Finally, natural selection signatures were detected in a batch of genes associated with immune response, human height, skin pigmentation, hair and facial morphology and blood pressure in MEGs. Notable examples include SYN3 which is associated with human height in all Orang Asli groups, a height-related gene (PNPT1) and two blood pressure-related genes (CDH13 and PAX5) in Negritos. We conclude that a long isolation period, subsequent gene flow and local adaptations have jointly shaped the genetic architectures of MEGs, and this study provides insight into the peopling and human migration

  7. Physicochemical characterization of Gozitan Honey

    Everaldo Attard

    2013-10-01

    Full Text Available Honey quality is clearly defined in the EU Directive 2001/110/EC, and by Codex Alimentarius (Codex Stan 12-1981 and the International Honey Commission (IHC, 2002. Our investigation aimed to characterize the physicochemical properties of honey produced on a small island, Gozo which is situated near Malta.  Ten randomly collected honey samples were analysed for moisture content, pH, free acidity, water insoluble content, hydroxymethylfurfural (HMF content and total phenolic compounds.  Moisture content, pH, free acidity, water insoluble content, and HMF content were within the range specified in standards but the electrical conductivity was generally higher than 0.800 mS cm-1. This may be the result of the relatively high atmospheric and soil salinity on this small island. All the samples analysed were within the 40 mg kg-1 HMF limit, which is an indicator of honey quality. The total phenolic compounds, which represent some of the constituents derived from the nectar and pollen obtained during foraging, ranged between 236.555 and 294.209 GAE kg-1 honey. Principal Component Analysis showed the properties of polyfloral honey samples obtained from the southern part of the island to be different from those obtained from the northern part.

  8. Synthesis, structure, physicochemical characterization and electronic structure of thio-lithium super ionic conductors, Li{sub 4}GeS{sub 4} and Li{sub 4}SnS{sub 4}

    MacNeil, Joseph H. [Department of Chemistry, Chatham University, 1 Woodland Road, Pittsburgh, PA 15232 (United States); Massi, Danielle M.; Zhang, Jian-Han; Rosmus, Kimberly A.; Brunetta, Carl D.; Gentile, Taylor A. [Department of Chemistry and Biochemistry, Duquesne University, 600 Forbes Ave., Pittsburgh, PA 15282 (United States); Aitken, Jennifer A., E-mail: aitkenj@duq.edu [Department of Chemistry and Biochemistry, Duquesne University, 600 Forbes Ave., Pittsburgh, PA 15282 (United States)

    2014-02-15

    Highlights: • The title compounds were prepared by a high-temperature, direct-combination route. • The room temperature structure of Li{sub 4}SnS{sub 4} is reported in space group Pnma. • The Li(2)S{sub 4} tetrahedra invert upon going from the RT to low temperature structure. • Electronic structure calculations indicate the Li–S bonding to be primarily ionic. • Li{sub 4}GeS{sub 4} and Li{sub 4}SnS{sub 4} have shown to be stable up to ∼850 and 950 °C respectively. -- Abstract: Li{sub 4}SnS{sub 4} and Li{sub 4}GeS{sub 4} were synthesized by single-step, high-temperature, solid-state methods. The room temperature (296 K) structures of both compounds were determined from single crystal X-ray diffraction, and were found to be isostructural. Both room temperature structures exhibit significant variations from a 100 K structure of Li{sub 4}SnS{sub 4} published recently by Kaib et al. (Chem. Mater. 24 (2012) 2211–2219). Differential thermal analysis (DTA) shows that in the absence of air, both Li{sub 4}SnS{sub 4} and Li{sub 4}GeS{sub 4} are thermally stable at least up to their melting points of 858 °C (Li{sub 4}GeS{sub 4}) and 958 °C (Li{sub 4}SnS{sub 4}). The band gaps for Li{sub 4}GeS{sub 4} and Li{sub 4}SnS{sub 4} are 4.13 eV and 3.54 eV respectively, measured using optical diffuse reflectance spectroscopy in the UV/Vis/NIR regions. Electronic band structure calculations using density functional theory as implemented in CASTEP predict an indirect band gap for Li{sub 4}GeS{sub 4} and a direct band gap for Li{sub 4}SnS{sub 4}. The (Sn/Ge)–S bonds were determined to have significant covalent bonding character, while the Li–S bonds are primarily ionic in nature.

  9. Sequential Adaptive RBF-Fuzzy Variable Structure Control Applied to Robotics Systems

    Mohammed Salem

    2014-08-01

    Full Text Available In this paper, we present a combination of sequential trained radial basis function networks and fuzzy techniques to enhance the variable structure controllers dedicated to robotics systems. In this aim, four RBFs networks were used to estimate the model based part parameters (Inertia, Centrifugal and Coriolis, Gravity and Friction matrices of a variable structure controller so to respond to model variation and disturbances, a sequential online training algorithm based on Growing-Pruning "GAP" strategy and Kalman filter was implemented. To eliminate the chattering effect, the corrective control of the VS control was computed by a fuzzy controller. Simulations are carried out to control three degrees of freedom SCARA robot manipulator where the obtained results show good disturbance rejection and chattering elimination.

  10. Small artery structure adapts to vasodilatation rather than to blood pressure during antihypertensive treatment

    Mathiassen, Ole N; Buus, Niels H; Larsen, Mogens L; Mulvany, Michael J; Christensen, Kent L

    2007-01-01

    OBJECTIVE: Correction of the abnormal structure of resistance arteries in essential hypertension may be an important treatment goal in addition to blood pressure (BP) reduction. We investigated how this may be achieved in a prospective clinical study. METHODS: Plethysmography was used to measure....... RESULTS: In group A, mean ambulatory blood pressure (ABP) fell from 119 +/- 2 (SE) to 103 +/- 2 mmHg (P < 0.01), whereas mean ABP was unchanged in group B (100 +/- 1 to 99 +/- 1 mmHg, P = NS). Both groups showed similar reductions in Rrest (-33.4 and -28.5%, respectively) and in Rmin (-15.4 and -15...... forearm resting vascular resistance (Rrest) and minimum vascular resistance (Rmin) as a measure of vascular structure. Two different groups of patients with essential hypertension were examined at baseline and after 6 months of antihypertensive treatment. In group A, 21 patients with never...

  11. Features of the structural organization of practical preparation of experts in the field of adaptive physical training

    Vasenin G.A.

    2012-04-01

    Full Text Available A research purpose was a ground of structure and maintenance of the type stage to practical oriented preparations of students. In an experiment accepted участие190 students. As criteria quantitative and high-quality indexes, reflecting the level of domain students by knowledges and abilities of professional activity of specialist of adaptive physical culture in school educational establishments, were used. Registration of these indexes was carried out in a few stages for period of teaching of students. The estimations of 3 basic forms of employments are resulted: health measures in the mode of educational day, employments by a medical physical culture (by a correction gymnastics, employments by the physical culture of the fixed type. It is marked that more than 87% students of experimental group got in the total an estimation «fine», other - «well».

  12. Multiclass Classification by Adaptive Network of Dendritic Neurons with Binary Synapses Using Structural Plasticity

    Hussain, Shaista; Basu, Arindam

    2016-01-01

    The development of power-efficient neuromorphic devices presents the challenge of designing spike pattern classification algorithms which can be implemented on low-precision hardware and can also achieve state-of-the-art performance. In our pursuit of meeting this challenge, we present a pattern classification model which uses a sparse connection matrix and exploits the mechanism of nonlinear dendritic processing to achieve high classification accuracy. A rate-based structural learning rule f...

  13. Facilitating Emergent and Adaptive Information Structures in Enterprise 2.0 Platforms

    Neubert, Christian

    2013-01-01

    Enterprise 2.0 platforms are increasingly being used as lightweight repositories that allow users to collaboratively manage information. However, due to the free-form nature of the content managed on these platforms (e.g., wiki pages), efficient information retrieval becomes challenging with a growing number of users. Hybrid Wikis empower business users to incrementally structure and classify content using attributes, types, and constraints. This way, users can access content like an object-o...

  14. Multiclass Classification by Adaptive Network of Dendritic Neurons with Binary Synapses using Structural Plasticity

    Shaista eHussain; Arindam eBasu

    2016-01-01

    The development of power-efficient neuromorphic devices presents the challenge of designing spike pattern classification algorithms which can be implemented on low-precision hardware and can also achieve state-of-the-art performance. In our pursuit of meeting this challenge, we present a pattern classification model which uses a sparse connection matrix and exploits the mechanism of nonlinear dendritic processing to achieve high classification accuracy. A rate-based structural learning rule f...

  15. Weedy Adaptation in Setaria spp.: VIII. Structure of Setaria faberi Seed, Caryopsis and Embryo Germination

    Haar, Milt; van Aelst, Adriaan; Dekker, Jack

    2014-01-01

    Giant foxtail (Setaria faberi) seeds differ in requirements for germination. Variable germinability arises during seed development under the influence of genotype, environment and parent plant. Giant foxtail seed germination has been shown to be regulated by independent asynchronous or dependent synchronous action of seed structures. To gain better insight into the process, germination was divided into axis specific embryo growth categories or states. Three states were defined for each embryo...

  16. A Nonlinear Dual-Adaptive Control Strategy for Identification and Control of Flexible Structures

    Thau, F. E.

    1985-01-01

    A technique is presented for obtaining a control law to regulate the modal dynamics and identify the modal parameters of a flexible structure. The method is based on using a min-max performance index to derive a control law which may be considered to be a best compromise between optimum one step control and identification inputs. Features of the approach are demonstrated by a computer simulation of the controlled modal response of a flexible beam.

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

    Plotnikova, S. V.; KULIKOV M.G.

    2011-01-01

    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 thermopiezoel...

  18. Special Issue: Adaptive/Smart Structures and Multifunctional Materials with Application to Morphing Aircraft

    Rafic Ajaj

    2014-12-01

    Full Text Available Recent advances in smart structures and multifunctional materials have facilitated many novel aerospace technologies such as morphing aircraft. A morphing aircraft, bio-inspired by natural fliers, has gained a lot of interest as a potential technology to meet the ambitious goals of the Advisory Council for Aeronautics Research in Europe (ACARE Vision 2020 and the FlightPath 2050 documents. A morphing aircraft continuously adjusts its wing geometry to enhance flight performance, control authority, and multi-mission capability.[...

  19. In Silico Analysis of β-Galactosidases Primary and Secondary Structure in relation to Temperature Adaptation

    Vijay Kumar

    2014-01-01

    Full Text Available β-D-Galactosidases (EC 3.2.1.23 hydrolyze the terminal nonreducing β-D-galactose residues in β-D-galactosides and are ubiquitously present in all life forms including extremophiles. Eighteen microbial β-galactosidase protein sequences, six each from psychrophilic, mesophilic, and thermophilic microbes, were analyzed. Primary structure reveals alanine, glycine, serine, and arginine to be higher in psychrophilic β-galactosidases whereas valine, glutamine, glutamic acid, phenylalanine, threonine, and tyrosine are found to be statistically preferred by thermophilic β-galactosidases. Cold active β-galactosidase has a strong preference towards tiny and small amino acids, whereas high temperature inhabitants had higher content of basic and aromatic amino acids. Thermophilic β-galactosidases have higher percentage of α-helix region responsible for temperature tolerance while cold loving β-galactosidases had higher percentage of sheet and coil region. Secondary structure analysis revealed that charged and aromatic amino acids were significant for sheet region of thermophiles. Alanine was found to be significant and high in the helix region of psychrophiles and valine counters in thermophilic β-galactosidase. Coil region of cold active β-galactosidase has higher content of tiny amino acids which explains their high catalytic efficiency over their counterparts from thermal habitat. The present study has revealed the preference or prevalence of certain amino acids in primary and secondary structure of psychrophilic, mesophilic, and thermophilic β-galactosidase.

  20. Collagen-curcumin interaction - A physico-chemical study

    N Nishad Fathima; R Saranya Devi; K B Rekha; Aruna Dhathathreyan

    2009-07-01

    Curcumin is a widely used therapeutic agent with a wide spectrum of biological and physiological applications like wound healing and interacts with the skin protein, collagen. This work reports the effect of curcumin on various physico-chemical properties of collagen. The results suggest that significant changes in viscosity and surface tension occur on collagen interacting with curcumin. Secondary structure analysis using circular dichroism shows that curcumin does not alter the triple helical structure of collagen. Increasing concentration of curcumin resulted in aggregation of the protein. Further, curcumin imparts high level of thermal stability to collagen with shrinkage temperature of collagen increasing from 60 to 90°C.

  1. Adaptation of high viscous dampers (HVD) for essential decreasing of in-structure floor response spectra

    This paper concerns a further development of High Viscous Damper (HVD) approach for essential decreasing of structure's floor response spectra. Usually restraining of components and pipelines by HVD is used for significant decreasing of operational vibration and seismic loads. A new approach consists of dampers installation for essential upgrading of a whole system's damping that is much more efficient in both technical and economical points of view than restraining of each component of the system. In that way using of HVD means high energy dissipation for whole dynamic system 'Building-Components' subjected to the base seismic or other extreme load excitation. The specific feature of each NPP site is an existing of a few closely spaced buildings: reactor building, turbine hall and so on. As the rule such buildings play sufficiently different roles in NPP operation and therefore have sufficiently different design, natural frequencies (periods) and distortion of floors and different rocking modes on a soil. The main idea explained in the paper is an interconnection of buildings by HVD. Then differences in their mechanical properties provide their out-of-phase relative motions during an earthquake and therefore effective dissipative work provided by HVD devices. At the same time implementation of HVD approach allows to eliminate possible interactions and collisions in the gaps between building structures that wears potential threat of building failure. The detailed 3D finite element models of reactor building, turbine hall and special building were developed for NPP with VVER-1000 MWt reactor type. Performed analysis has shown high efficiency of suggested approach for protection of buildings, structures, systems and components against seismic and other impacts. (authors)

  2. Development of Micro Air Vehicle Technology With In-Flight Adaptive-Wing Structure

    Waszak, Martin R. (Technical Monitor); Shkarayev, Sergey; Null, William; Wagner, Matthew

    2004-01-01

    This is a final report on the research studies, "Development of Micro Air Vehicle Technology with In-Flight Adaptrive-Wing Structure". This project involved the development of variable-camber technology to achieve efficient design of micro air vehicles. Specifically, it focused on the following topics: 1) Low Reynolds number wind tunnel testing of cambered-plate wings. 2) Theoretical performance analysis of micro air vehicles. 3) Design of a variable-camber MAV actuated by micro servos. 4) Test flights of a variable-camber MAV.

  3. Structural and functional neural adaptations in obstructive sleep apnea: An activation likelihood estimation meta-analysis.

    Tahmasian, Masoud; Rosenzweig, Ivana; Eickhoff, Simon B; Sepehry, Amir A; Laird, Angela R; Fox, Peter T; Morrell, Mary J; Khazaie, Habibolah; Eickhoff, Claudia R

    2016-06-01

    Obstructive sleep apnea (OSA) is a common multisystem chronic disorder. Functional and structural neuroimaging has been widely applied in patients with OSA, but these studies have often yielded diverse results. The present quantitative meta-analysis aims to identify consistent patterns of abnormal activation and grey matter loss in OSA across studies. We used PubMed to retrieve task/resting-state functional magnetic resonance imaging and voxel-based morphometry studies. Stereotactic data were extracted from fifteen studies, and subsequently tested for convergence using activation likelihood estimation. We found convergent evidence for structural atrophy and functional disturbances in the right basolateral amygdala/hippocampus and the right central insula. Functional characterization of these regions using the BrainMap database suggested associated dysfunction of emotional, sensory, and limbic processes. Assessment of task-based co-activation patterns furthermore indicated that the two regions obtained from the meta-analysis are part of a joint network comprising the anterior insula, posterior-medial frontal cortex and thalamus. Taken together, our findings highlight the role of right amygdala, hippocampus and insula in the abnormal emotional and sensory processing in OSA. PMID:27039344

  4. Mechanical adaptability of the Bouligand-type structure in natural dermal armour.

    Zimmermann, Elizabeth A; Gludovatz, Bernd; Schaible, Eric; Dave, Neil K N; Yang, Wen; Meyers, Marc A; Ritchie, Robert O

    2013-01-01

    Arapaima gigas, a fresh water fish found in the Amazon Basin, resist predation by piranhas through the strength and toughness of their scales, which act as natural dermal armour. Arapaima scales consist of a hard, mineralized outer shell surrounding a more ductile core. This core region is composed of aligned mineralized collagen fibrils arranged in distinct lamellae. Here we show how the Bouligand-type (twisted plywood) arrangement of collagen fibril lamellae has a key role in developing their unique protective properties, by using in situ synchrotron small-angle X-ray scattering during mechanical tensile tests to observe deformation mechanisms in the fibrils. Specifically, the Bouligand-type structure allows the lamellae to reorient in response to the loading environment; remarkably, most lamellae reorient towards the tensile axis and deform in tension through stretching/sliding mechanisms, whereas other lamellae sympathetically rotate away from the tensile axis and compress, thereby enhancing the scale's ductility and toughness to prevent fracture. PMID:24129554

  5. Structural and Functional Insights into the Evolution and Stress Adaptation of Type II Chaperonins.

    Chaston, Jessica J; Smits, Callum; Aragão, David; Wong, Andrew S W; Ahsan, Bilal; Sandin, Sara; Molugu, Sudheer K; Molugu, Sanjay K; Bernal, Ricardo A; Stock, Daniela; Stewart, Alastair G

    2016-03-01

    Chaperonins are essential biological complexes assisting protein folding in all kingdoms of life. Whereas homooligomeric bacterial GroEL binds hydrophobic substrates non-specifically, the heterooligomeric eukaryotic CCT binds specifically to distinct classes of substrates. Sulfolobales, which survive in a wide range of temperatures, have evolved three different chaperonin subunits (α, β, γ) that form three distinct complexes tailored for different substrate classes at cold, normal, and elevated temperatures. The larger octadecameric β complexes cater for substrates under heat stress, whereas smaller hexadecameric αβ complexes prevail under normal conditions. The cold-shock complex contains all three subunits, consistent with greater substrate specificity. Structural analysis using crystallography and electron microscopy reveals the geometry of these complexes and shows a novel arrangement of the α and β subunits in the hexadecamer enabling incorporation of the γ subunit. PMID:26853941

  6. Adaptation of Campylobacter jejuni to biocides used in the food industry affects biofilm structure, adhesion strength, and cross-resistance to clinical antimicrobial compounds.

    Techaruvichit, Punnida; Takahashi, Hajime; Kuda, Takashi; Miya, Satoko; Keeratipibul, Suwimon; Kimura, Bon

    2016-08-01

    The emergence of biocide-adapted Campylobacter jejuni strains that developed into biofilms and their potential to develop clinical resistance to antimicrobial compounds was studied. C. jejuni was grown in sub-lethal concentrations of five biocides used in the food industry. C. jejuni exhibited adaptation to these biocides with increased minimum inhibitory concentrations. The 3-D structures of the biofilms produced by the biocide-adapted cells were investigated by atomic force microscopy (AFM). The results revealed marked variability in biofilm architecture, including ice-crystal-like structures. Adaptation to the biocides enhanced biofilm formation, with significant increases in biovolume, surface coverage, roughness, and the surface adhesion force of the biofilms. Adaptation to commercial biocides induced resistance to kanamycin and streptomycin. This study suggests that the inappropriate use of biocides may lead to cells being exposed to them at sub-lethal concentrations, which can result in adaptation of the pathogens to the biocides and a subsequent risk to public health. PMID:27353218

  7. An application of neural network for Structural Health Monitoring of an adaptive wing with an array of FBG sensors

    This paper presents an application of neural networks to determinate the level of activation of shape memory alloy actuators of an adaptive wing. In this concept the shape of the wing can be controlled and altered thanks to the wing design and the use of integrated shape memory alloy actuators. The wing is assumed as assembled from a number of wing sections that relative positions can be controlled independently by thermal activation of shape memory actuators. The investigated wing is employed with an array of Fibre Bragg Grating sensors. The Fibre Bragg Grating sensors with combination of a neural network have been used to Structural Health Monitoring of the wing condition. The FBG sensors are a great tool to control the condition of composite structures due to their immunity to electromagnetic fields as well as their small size and weight. They can be mounted onto the surface or embedded into the wing composite material without any significant influence on the wing strength. The paper concentrates on analysis of the determination of the twisting moment produced by an activated shape memory alloy actuator. This has been analysed both numerically using the finite element method by a commercial code ABAQUS (registered) and experimentally using Fibre Bragg Grating sensor measurements. The results of the analysis have been then used by a neural network to determine twisting moments produced by each shape memory alloy actuator.

  8. A new look at the structure of the Antarctic continent from P wave travel times and adaptively parameterized tomography

    Bishop, J. A.; Hansen, S. E.

    2011-12-01

    The geologic processes shaping the Antarctic continent are widely debated. In order to evaluate candidate models for the region, tomographic images that highlight the upper mantle structure are crucial; however, existing continental-scale tomography models for Antarctica lack sufficient resolution to delineate important, diagnostic features. Most tomographic models are generated using a uniformly-spaced grid over the entire study area, which can result in reduced resolution by over-emphasizing poorly sampled areas of the model and not providing enough emphasis in areas containing pertinent small-scale structure. Alternatively, the adaptively parameterized tomography method constructs a more condensed grid spacing in areas with better seismic ray coverage, thereby allowing such regions to be better resolved, while at the same time limiting the resolution of features in areas with less seismic coverage. By generating such a model for Antarctica, this approach allows candidate geologic models to be more critically assessed, resulting in a better understanding not only of Antarctic geodynamic processes but also of important processes on a global scale. In addition, the resulting tomographic model will impact thermal lithospheric estimates used to characterize ice sheet dynamics and climate-ice models, which are important in understanding the cooling history of the continent. Preliminary results will be shown.

  9. Population genomic structure and adaptation in the zoonotic malaria parasite Plasmodium knowlesi.

    Assefa, Samuel; Lim, Caeul; Preston, Mark D; Duffy, Craig W; Nair, Mridul B; Adroub, Sabir A; Kadir, Khamisah A; Goldberg, Jonathan M; Neafsey, Daniel E; Divis, Paul; Clark, Taane G; Duraisingh, Manoj T; Conway, David J; Pain, Arnab; Singh, Balbir

    2015-10-20

    Malaria cases caused by the zoonotic parasite Plasmodium knowlesi are being increasingly reported throughout Southeast Asia and in travelers returning from the region. To test for evidence of signatures of selection or unusual population structure in this parasite, we surveyed genome sequence diversity in 48 clinical isolates recently sampled from Malaysian Borneo and in five lines maintained in laboratory rhesus macaques after isolation in the 1960s from Peninsular Malaysia and the Philippines. Overall genomewide nucleotide diversity (π = 6.03 × 10(-3)) was much higher than has been seen in worldwide samples of either of the major endemic malaria parasite species Plasmodium falciparum and Plasmodium vivax. A remarkable substructure is revealed within P. knowlesi, consisting of two major sympatric clusters of the clinical isolates and a third cluster comprising the laboratory isolates. There was deep differentiation between the two clusters of clinical isolates [mean genomewide fixation index (FST) = 0.21, with 9,293 SNPs having fixed differences of FST = 1.0]. This differentiation showed marked heterogeneity across the genome, with mean FST values of different chromosomes ranging from 0.08 to 0.34 and with further significant variation across regions within several chromosomes. Analysis of the largest cluster (cluster 1, 38 isolates) indicated long-term population growth, with negatively skewed allele frequency distributions (genomewide average Tajima's D = -1.35). Against this background there was evidence of balancing selection on particular genes, including the circumsporozoite protein (csp) gene, which had the top Tajima's D value (1.57), and scans of haplotype homozygosity implicate several genomic regions as being under recent positive selection. PMID:26438871

  10. Nonlinear fitness-space-structure adaptation and principal component analysis in genetic algorithms: an application to x-ray reflectivity analysis

    Tiilikainen, J [Micro- and Nanosciences Laboratory, Helsinki University of Technology, Micronova, PO Box 3500, FI-02015 TKK (Finland); Tilli, J-M [Micro- and Nanosciences Laboratory, Helsinki University of Technology, Micronova, PO Box 3500, FI-02015 TKK (Finland); Bosund, V [Micro- and Nanosciences Laboratory, Helsinki University of Technology, Micronova, PO Box 3500, FI-02015 TKK (Finland); Mattila, M [Micro- and Nanosciences Laboratory, Helsinki University of Technology, Micronova, PO Box 3500, FI-02015 TKK (Finland); Hakkarainen, T [Micro- and Nanosciences Laboratory, Helsinki University of Technology, Micronova, PO Box 3500, FI-02015 TKK (Finland); Airaksinen, V-M [MINFAB, Helsinki University of Technology, Micronova, PO Box 3500, FI-02015 TKK (Finland); Lipsanen, H [Micro- and Nanosciences Laboratory, Helsinki University of Technology, Micronova, PO Box 3500, FI-02015 TKK (Finland)

    2007-01-07

    Two novel genetic algorithms implementing principal component analysis and an adaptive nonlinear fitness-space-structure technique are presented and compared with conventional algorithms in x-ray reflectivity analysis. Principal component analysis based on Hessian or interparameter covariance matrices is used to rotate a coordinate frame. The nonlinear adaptation applies nonlinear estimates to reshape the probability distribution of the trial parameters. The simulated x-ray reflectivity of a realistic model of a periodic nanolaminate structure was used as a test case for the fitting algorithms. The novel methods had significantly faster convergence and less stagnation than conventional non-adaptive genetic algorithms. The covariance approach needs no additional curve calculations compared with conventional methods, and it had better convergence properties than the computationally expensive Hessian approach. These new algorithms can also be applied to other fitting problems where tight interparameter dependence is present.

  11. Nonlinear fitness-space-structure adaptation and principal component analysis in genetic algorithms: an application to x-ray reflectivity analysis

    Two novel genetic algorithms implementing principal component analysis and an adaptive nonlinear fitness-space-structure technique are presented and compared with conventional algorithms in x-ray reflectivity analysis. Principal component analysis based on Hessian or interparameter covariance matrices is used to rotate a coordinate frame. The nonlinear adaptation applies nonlinear estimates to reshape the probability distribution of the trial parameters. The simulated x-ray reflectivity of a realistic model of a periodic nanolaminate structure was used as a test case for the fitting algorithms. The novel methods had significantly faster convergence and less stagnation than conventional non-adaptive genetic algorithms. The covariance approach needs no additional curve calculations compared with conventional methods, and it had better convergence properties than the computationally expensive Hessian approach. These new algorithms can also be applied to other fitting problems where tight interparameter dependence is present

  12. Physico-chemical studies on samarium soaps in solid state

    The physico-chemical characteristics of samarium soaps (caproate and caprate) in solid state were investigated by IR, X-ray diffraction and TGA measurements. The IR results revealed that the fatty acids exist in dimeric state through hydrogen bonding and samarium soaps possess partial ionic character. The X-ray diffraction measurements were used to calculate the long spacings and the results confirmed the double layer structure of samarium soaps. The decomposition reaction was found kinetically of zero order and the values of energy of activation for the decomposition process for caproate and caprate were found to be 8,0 and 7,8 kcal mol-1, respectively. (Authors)

  13. The Relationship of Organizational Structure to Organizational Adaptiveness in Elementary Schools. Report from the Project on Organization for Instruction and Administrative Arrangements.

    Walter, James Ellsworth

    This study attempted to examine the organizational structures of elementary schools in terms of complexity, centralization, formalization, stratification, and job satisfaction; and to analyze the relationship of these variables to the adaptiveness of elementary schools. More specifically, it compared the Multiunit School-Elementary (MUS-E) type of…

  14. Physicochemical properties of bismuth tungstate catalysts

    It is shown that in the Bi2O3-WO3 system there are formed the following compounds: 1. Bi2x3WO3=Bi(WO4)3 tsub(m)-890 deg C 2. Bi2O3x2WO3=Bi2W2O9 tsub(m)-910 deg C 3. Bi2O3xWO3=Bi2WO6 tsub(m)-1040 deg C 4. 3BiO3xWO3=Bi6WO12 tsub(m)-905 deg C In the 440-650 deg C range these compounds are characterized by endothermal maxima corresponding to dehydration and followed by exothermal maxima referred to the exothermal transition of some phases into other modifications. Increased catalytic activity is attributed to Bi2WO6 phase, activity and celectivity of which are bound with the presence of W-O octahedrons connected by the angles in the solid body volume, what leads to the growth of (W-O) tetrahonal-pyramidal centres on the surface. The concentration of such supposed active centres (W=O) reaches its maximum in Bi2WO6 phase, the least active phase Bi6WO12 having its maximum concentration of centres as W-O-W. Samples of Bi2(WO4)3 and Bi2W2O9 compositions have centres of both types. Correlation between physicochemical properties and activity shows that selective oxidation stops when Bi/W > 2, that is an active structural group of (Bi2O2)2+(WO4)2- octahedron type can exist in the catalyst containing Bi up to 57%

  15. EDITORIAL: Adaptive and active materials: Selected papers from the ASME 2011 Conference on Smart Materials, Adaptive Structures and Intelligent Systems (SMASIS 11) (Scottsdale, AZ, USA, 18-21 September 2011) Adaptive and active materials: Selected papers from the ASME 2011 Conference on Smart Materials, Adaptive Structures and Intelligent Systems (SMASIS 11) (Scottsdale, AZ, USA, 18-21 September 2011)

    Brei, Diann

    2012-09-01

    The fourth annual meeting of the ASME/AIAA Smart Materials, Adaptive Structures and Intelligent Systems Conference (SMASIS) took place in sunny Scottsdale, Arizona. Each year we strive to grow and offer new experiences. This year we held a special Guest Symposium on Sustainability along with two focused topic tracks on energy harvesting and active composites to encourage cross-fertilization between these important fields and our community. This cross-disciplinary emphasis was reflected in keynote talks by Dr Wayne Brown, President and founder of Dynalloy, Inc., 'Cross-Discipline Sharing'; Dr Brad Allenby, Arizona State University, 'You Want the Future? You can't Handle the Future!'; and Professor Aditi Chattopadhyay, Arizona State University, 'A Multidisciplinary Approach to Structural Health Monitoring and Prognosis'. SMASIS continues to grow our community through both social and technical interchange. The conference location, the exotic Firesky Resort and Spa, exemplified the theme of our Guest Symposium on Sustainability, being the only Green Seal certified resort in Arizona, and highlighting four elements thought to represent all that exist: fire, water, earth and air. Several special events were held around this theme including the night at the oasis reception sponsored by General Motors, sustainability bingo, smart trivia and student networking lunches, and an Arizona pow-wow with a spectacular Indian hoop dance. Our student and young professional development continues to grow strong with best paper and hardware competitions, scavenger student outing and games night. We are very proud that our students and young professionals are always seeking out ways to give back to the community, including organizing outreach to local high school talent. We thank all of our sponsors who made these special events possible. We hope that these social events provided participants with the opportunity to expand their own personal community and broaden their horizons. Our

  16. Oligomerization as a strategy for cold adaptation: Structure and dynamics of the GH1 β-glucosidase from Exiguobacterium antarcticum B7.

    Zanphorlin, Leticia Maria; de Giuseppe, Priscila Oliveira; Honorato, Rodrigo Vargas; Tonoli, Celisa Caldana Costa; Fattori, Juliana; Crespim, Elaine; de Oliveira, Paulo Sergio Lopes; Ruller, Roberto; Murakami, Mario Tyago

    2016-01-01

    Psychrophilic enzymes evolved from a plethora of structural scaffolds via multiple molecular pathways. Elucidating their adaptive strategies is instrumental to understand how life can thrive in cold ecosystems and to tailor enzymes for biotechnological applications at low temperatures. In this work, we used X-ray crystallography, in solution studies and molecular dynamics simulations to reveal the structural basis for cold adaptation of the GH1 β-glucosidase from Exiguobacterium antarcticum B7. We discovered that the selective pressure of low temperatures favored mutations that redesigned the protein surface, reduced the number of salt bridges, exposed more hydrophobic regions to the solvent and gave rise to a tetrameric arrangement not found in mesophilic and thermophilic homologues. As a result, some solvent-exposed regions became more flexible in the cold-adapted tetramer, likely contributing to enhance enzymatic activity at cold environments. The tetramer stabilizes the native conformation of the enzyme, leading to a 10-fold higher activity compared to the disassembled monomers. According to phylogenetic analysis, diverse adaptive strategies to cold environments emerged in the GH1 family, being tetramerization an alternative, not a rule. These findings reveal a novel strategy for enzyme cold adaptation and provide a framework for the semi-rational engineering of β-glucosidases aiming at cold industrial processes. PMID:27029646

  17. Adaptive Airborne Doppler Wind Lidar Beam Scanning Patterns for Complex Terrain and Small Scale Organized Atmospheric Structure Observations

    Emmitt, G.; O'Handley, C.; de Wekker, S. F.

    2008-12-01

    The conical scan is the traditional pattern used to obtain vertical profiles of the wind field with an airborne Doppler wind lidar. Nadir or zenith pointing scanning wedges are ideal for this type of scan. A bi-axis scanner has been operated on a Navy Twin Otter for more than 6 years and has been recently installed on a Navy P3 for use in a field experiment to study typhoons. The bi-axis scanner enables a broad range of scanning patterns. A subset of the possible patterns is critical to obtaining useful wind profiles in the presence of complex terrain or small (~ 100's of meters) organized atmospheric structures (rolls, updrafts, waves, etc). Several scanning strategies have been tested in flights over the Monterey Peninsula and within tropical cyclones. Combined with Google Earth (on-board) and satellite imagery overlays, new realtime adaptive scanning algorithms are being developed and tested. The results of these tests (both real and simulated) will be presented in the form of case studies.

  18. In-Flight Suppression of a De-Stabilized F/A-18 Structural Mode Using the Space Launch System Adaptive Augmenting Control System

    Wall, John; VanZwieten, Tannen; Giiligan Eric; Miller, Chris; Hanson, Curtis; Orr, Jeb

    2015-01-01

    Adaptive Augmenting Control (AAC) has been developed for NASA's Space Launch System (SLS) family of launch vehicles and implemented as a baseline part of its flight control system (FCS). To raise the technical readiness level of the SLS AAC algorithm, the Launch Vehicle Adaptive Control (LVAC) flight test program was conducted in which the SLS FCS prototype software was employed to control the pitch axis of Dryden's specially outfitted F/A-18, the Full Scale Advanced Systems Test Bed (FAST). This presentation focuses on a set of special test cases which demonstrate the successful mitigation of the unstable coupling of an F/A-18 airframe structural mode with the SLS FCS.

  19. Physico-chemical stability of tomato products.

    den Ouden, F.W.C.

    1995-01-01

    The effect of some physical processes and enzymatic hydrolysis on the physicochemical properties of tomato suspensions was studied.Concentration degree has a large effect on the apparent viscosity and the storage modulus of suspensions after being diluted to a standardized water insoluble solids lev

  20. Physico-chemical evaluation of Dovyalis spp

    The purpose of this research was to establish physico-chemical characterization of dovyalis hybrid fruits (MIA 25359). Samples of 30 fruits were characterized by evaluation of fruit and seed weight, length and width, percentage and number of seeds per fruit, peel and pulp percentage, total soluble s...

  1. Physicochemical Properties of Starch Isolated from Bracken (Pteridium aquilinim) Rhizome.

    Yu, Xurun; Wang, Jin; Zhang, Jing; Wang, Leilei; Wang, Zhong; Xiong, Fei

    2015-12-01

    Bracken (Pteridium aquilinum) is an important wild plant starch resource worldwide. In this work, starch was separated from bracken rhizome, and the physicochemical properties of this starch were systematically investigated and compared with 2 other common starches, that is, starches from waxy maize and potato. There were significant differences in shape, birefringence patterns, size distribution, and amylose content between bracken and the 2 other starches. X-ray diffraction analysis revealed that bracken starch exhibited a typical C-type crystalline structure. Bracken starch presented, respectively, lower and higher relative degree of crystallinity than waxy maize and potato starches. Ordered structures in particle surface differed among these 3 starches. The swelling power tendency of bracken starch in different temperature intervals was very similar to that of potato starch. The viscosity parameters during gelatinization were the lowest in waxy maize, followed by bracken and potato starches. The contents of 3 nutritional components, that is, rapidly digestible, slowly digestible, and resistant starches in native, gelatinized, and retrograded starch from bracken rhizome presented more similarities with potato starch than waxy maize starch. These finding indicated that physicochemical properties of bracken starch showed more similarities with potato starch than waxy maize starch. PMID:26551243

  2. The structural rigidity of the cranium of Australopithecus africanus: implications for diet, dietary adaptations, and the allometry of feeding biomechanics.

    Strait, David S; Grosse, Ian R; Dechow, Paul C; Smith, Amanda L; Wang, Qian; Weber, Gerhard W; Neubauer, Simon; Slice, Dennis E; Chalk, Janine; Richmond, Brian G; Lucas, Peter W; Spencer, Mark A; Schrein, Caitlin; Wright, Barth W; Byron, Craig; Ross, Callum F

    2010-04-01

    Australopithecus africanus is an early hominin (i.e., human relative) believed to exhibit stress-reducing adaptations in its craniofacial skeleton that may be related to the consumption of resistant food items using its premolar teeth. Finite element analyses simulating molar and premolar biting were used to test the hypothesis that the cranium of A. africanus is structurally more rigid than that of Macaca fascicularis, an Old World monkey that lacks derived australopith facial features. Previously generated finite element models of crania of these species were subjected to isometrically scaled loads, permitting a direct comparison of strain magnitudes. Moreover, strain energy (SE) in the models was compared after results were scaled to account for differences in bone volume and muscle forces. Results indicate that strains in certain skeletal regions below the orbits are higher in M. fascicularis than in A. africanus. Moreover, although premolar bites produce von Mises strains in the rostrum that are elevated relative to those produced by molar biting in both species, rostral strains are much higher in the macaque than in the australopith. These data suggest that at least the midface of A. africanus is more rigid than that of M. fascicularis. Comparisons of SE reveal that the A. africanus cranium is, overall, more rigid than that of M. fascicularis during premolar biting. This is consistent with the hypothesis that this hominin may have periodically consumed large, hard food items. However, the SE data suggest that the A. africanus cranium is marginally less rigid than that of the macaque during molar biting. It is hypothesized that the SE results are being influenced by the allometric scaling of cranial cortical bone thickness. PMID:20235314

  3. Adapt or Die

    Brody, Joshua Eric; Larsen, Kasper Green

    2015-01-01

    In this paper, we study the role non-adaptivity plays in maintaining dynamic data structures. Roughly speaking, a data structure is non-adaptive if the memory locations it reads and/or writes when processing a query or update depend only on the query or update and not on the contents of previously...... read cells. We study such non-adaptive data structures in the cell probe model. This model is one of the least restrictive lower bound models and in particular, cell probe lower bounds apply to data structures developed in the popular word-RAM model. Unfortunately, this generality comes at a high cost......: the highest lower bound proved for any data structure problem is only polylogarithmic. Our main result is to demonstrate that one can in fact obtain polynomial cell probe lower bounds for non-adaptive data structures. To shed more light on the seemingly inherent polylogarithmic lower bound barrier, we...

  4. State recognition of the viscoelastic sandwich structure based on the adaptive redundant second generation wavelet packet transform, permutation entropy and the wavelet support vector machine

    The viscoelastic sandwich structure is widely used in mechanical equipment, yet the structure always suffers from damage during long-term service. Therefore, state recognition of the viscoelastic sandwich structure is very necessary for monitoring structural health states and keeping the equipment running with high reliability. Through the analysis of vibration response signals, this paper presents a novel method for this task based on the adaptive redundant second generation wavelet packet transform (ARSGWPT), permutation entropy (PE) and the wavelet support vector machine (WSVM). In order to tackle the non-linearity existing in the structure vibration response, the PE is introduced to reveal the state changes of the structure. In the case of complex non-stationary vibration response signals, in order to obtain more effective information regarding the structural health states, the ARSGWPT, which can adaptively match the characteristics of a given signal, is proposed to process the vibration response signals, and then multiple PE features are extracted from the resultant wavelet packet coefficients. The WSVM, which can benefit from the conventional SVM as well as wavelet theory, is applied to classify the various structural states automatically. In this study, to achieve accurate and automated state recognition, the ARSGWPT, PE and WSVM are combined for signal processing, feature extraction and state classification, respectively. To demonstrate the effectiveness of the proposed method, a typical viscoelastic sandwich structure is designed, and the different degrees of preload on the structure are used to characterize the various looseness states. The test results show that the proposed method can reliably recognize the different looseness states of the viscoelastic sandwich structure, and the WSVM can achieve a better classification performance than the conventional SVM. Moreover, the superiority of the proposed ARSGWPT in processing the complex vibration response

  5. EDITORIAL Smart materials, multifunctional composites, and morphing structures: selected papers from the 20th International Conference on Adaptive Structures and Technologies (ICAST 2009) Smart materials, multifunctional composites, and morphing structures: selected papers from the 20th International Conference on Adaptive Structures and Technologies (ICAST 2009)

    Liao, Wei-Hsin

    2010-12-01

    The 20th International Conference on Adaptive Structures and Technologies (ICAST) was held on 20-22 October 2009 in Hong Kong. This special section of Smart Materials and Structures is derived from the research papers presented at the conference. Of the 106 papers presented at the conference, 11 papers were reviewed and accepted for this special section, following the regular review procedures of the journal. This special section is focused on smart materials, multifunctional composites, and applications on morphing structures. Smart materials. Smart materials are the foundation of adaptive structures and intelligent systems. The development of new materials will lead to significant improvement in various applications. Three articles are focused on the fabrication of new materials and investigation of their behaviors: Barium strontium zirconate titanate ((Ba1-xSrx)(ZrxTi1-x)O3; BSZT, x = 0.25 and 0.75) ceramics with a highly crystalline structure were fabricated using the combustion technique. The microstructure of BSZT powders exhibited an almost-spherical morphology and had a porous agglomerated form. Polyaniline (PANI)/clay nanoparticles with unique core-shell structure were synthesized via Pickering emulsion polymerization. By dispersing PANI/clay nanoparticles in silicone oil, the ER fluid was made. Magnetic field effects were investigated on the deposition rate and surface morphology of chromium nitride coatings deposited by magnetron sputtering for superior hardness, excellent wear and oxidation resistance. The surface morphology of chromium nitride films was also examined by a scanning electron microscope (SEM). Multifunctional composites. Composites are made from two or more constituent materials so they can combine the best properties of different materials. Five papers deal with fabrication, testing, and modeling of various multifunctional composites: A new active structural fiber (ASF) was fabricated by coating a single carbon fiber with a concentric

  6. High-altitude adaptations in vertebrate hemoglobins

    Weber, Roy E.

    2007-01-01

    ’s intrinsic O2-affinity and its allosteric interaction with cellular effectors (organic phosphates, protons and chloride). Whereas short-term altitudinal adaptations predominantly involve adjustments in allosteric interactions, long-term, genetically-coded adaptations typically involve changes in the....... Molecular heterogeneity (multiple isoHbs with differentiated oxygenation properties) can further broaden the range of physico-chemical conditions where Hb functions under altitudinal hypoxia. This treatise reviews the molecular and cellular mechanisms that adapt haemoglobin-oxygen affinities in mammals......, birds and ectothermic vertebrates at high altitude....

  7. Structural and functional cardiac adaptations to a 10-week school-based football intervention for 9-10-year-old children

    Krustrup, Peter; Hansen, Peter Riis; Nielsen, Claus Malta;

    2014-01-01

    The present study investigated the cardiac effects of a 10-week football training intervention for school children aged 9-10 years using comprehensive transthoracic echocardiography as a part of a larger ongoing study. A total of 97 pupils from four school classes were cluster-randomized into a c...... pressure. In conclusion, a short-term, school-based intervention comprising small-sided football sessions resulted in significant structural and functional cardiac adaptations in pre-adolescent children....

  8. Improving drug candidates by design: a focus on physicochemical properties as a means of improving compound disposition and safety.

    Meanwell, Nicholas A

    2011-09-19

    refinement, while deeper analyses have explored the correlation with metabolic stability and toxicity. These insights have been augmented by careful analyses of physicochemical aspects of drug-target interactions, with thermodynamic profiling indicating that the signature of best-in-class drugs is a dependence on enthalpy to drive binding energetics rather than entropy, which is dependent on lipophilicity. Optimization of the entropic contribution to the binding energy of a ligand to its target is generally much easier than refining the enthalpic element. Consequently, in the absence of a fundamental understanding of the thermodynamic complexion of an interaction, the design of molecules with increased lipophilicity becomes almost inevitable. The application of ligand efficiency, a measure of affinity per heavy atom, group efficiency, which assesses affinity in the context of structural changes, and lipophilic ligand efficiency, which relates potency to lipophilicity, offer less sophisticated but practically useful analytical algorithms to assess the quality of drug-target interactions. These parameters are readily calculated and can be applied to lead optimization programs in a fashion that helps to maximize potency while minimizing the kind of lipophilic burden that has been dubbed "molecular obesity". Several recently described lead optimization campaigns provide illustrative, informative, and productive examples of the effect of paying close attention to carefully controlling physicochemical properties by monitoring ligand efficiency and lipophilic ligand efficiency. However, to be successful during the lead optimization phase, drug candidate identification programs will need to adopt a holistic approach that integrates multiple parameters, many of which will have unique dependencies on both the drug target and the specific chemotype under prosecution. Nevertheless, there are many important drug targets that necessitate working in space beyond that which has been defined

  9. Physicochemical properties of TiO2/Hydroxyapatite nanocomposite

    The TiO2/Hydroxyapatite (TiO2/HAp) nanocomposites with different ratios were prepared by precipitation of hydroxyapatite in the presence of TiO2 or TiO(OH)2. The physicochemical properties of TiO2/HAp material were characterized using the batch equilibration method and BET, XPS, DRS, FTIR analyses. The XPS result showed that binding energy of Ca-P was 347.2 eV, that of P-OH was 133.3 eV and the Ti 2p spectrum could be resolved into spin-orbit pairs 2p3/2 and 2p1/2 with binding energies of 458.6 and 464.1 eV, respectively, which are the characteristics of titanium(IV) in TiO2. The FTIR result suggested that the formation of the TiO2/HAp nanocomposites have not changed the structure nor the phase of the hydroxyapatite crystals. However, the physicochemical properties of TiO2/HAp nanocomposites such as pHpzc values, band gap energy, specific surface area and pore volume were higher than those of pure TiO2 and HAp. (author)

  10. Adaptive Architectural Envelope

    Foged, Isak Worre; Kirkegaard, Poul Henning

    2010-01-01

    Recent years have seen an increasing variety of applications of adaptive architectural structures for improvement of structural performance by recognizing changes in their environments and loads, adapting to meet goals, and using past events to improve future performance or maintain serviceability....... The general scopes of this paper are to develop a new adaptive kinetic architectural structure, particularly a reconfigurable architectural structure which can transform body shape from planar geometries to hyper-surfaces using different control strategies, i.e. a transformation into more than one or...... two different shape alternatives. The adaptive structure is a proposal for a responsive building envelope which is an idea of a first level operational framework for present and future investigations towards performance based responsive architectures through a set of responsive typologies. A mock- up...

  11. Adaptive and active materials: selected papers from the ASME 2013 Conference on Smart Materials, Adaptive Structures and Intelligent Systems (SMASIS 13) (Snowbird, UT, USA, 16-18 September 2013)

    Johnson, Nancy; Naguib, Hani; Turner, Travis; Anderson, Iain; Bassiri-Gharb, Nazanin; Daqaq, Mohammed; Baba Sundaresan, Vishnu; Sarles, Andy

    2014-10-01

    The sixth annual meeting of the ASME Smart Materials, Adaptive Structures and Intelligent Systems Conference (SMASIS) was held in the beautiful mountain encircled Snowbird Resort and Conference Center in Little Cottonwood Canyon near Salt Lake City, Utah. It is the conference's objective to provide an up-to-date overview of research trends in the entire field of smart materials systems in a friendly casual forum conducive to the exchange of ideas and latest results. As each year we strive to grow and offer new experiences, this year we included special focused topic tracks on nanoscale multiferroic materials and origami engineering. The cross-disciplinary emphasis was reflected in keynote speeches by Professor Kaushik Bhattacharya (California Institute of Technology) on 'Cyclic Deformation and the Interplay between Phase Transformation and Plasticity in Shape Memory Alloys', by Professor Alison Flatau (University of Maryland at College Park) on 'Structural Magnetostrictive Alloys: The Other Smart Material', and by Dr Leslie Momoda (Director of the Sensors and Materials Laboratories, HRL Laboratories, LLC, Malibu, CA) on 'Architecturing New Functional Materials: An Industrial Perspective'. SMASIS 2013 was divided into seven symposia which span basic research, applied technological design and development, and industrial and governmental integrated system and application demonstrations. SYMP 1. Development and Characterization of Multifunctional Materials. SYMP 2. Mechanics and Behavior of Active Materials. SYMP 3. Modeling, Simulation and Control of Adaptive Systems. SYMP 4. Integrated System Design and Implementation. SYMP 5. Structural Health Monitoring. SYMP 6. Bioinspired Smart Materials and Systems. SYMP 7. Energy Harvesting. Authors of selected papers in the materials areas (symposia 1, 2, and 6) as well as energy harvesting (symposium 7) were invited to write a full journal article on their presentation topic for publication in this special issue of Smart

  12. Physicochemical insight into gap openings in graphene

    Zhu, Y F; Dai, Q. Q.; Zhao, M.; Jiang, Q.

    2013-01-01

    Based on a newly developed size-dependent cohesive energy formula for two-dimensional materials, a unified theoretical model was established to illustrate the gap openings in disordered graphene flakes, involving quantum dots, nanoribbons and nanoporous sheets. It tells us that the openings are essentially dominated by the variation in cohesive energy of C atoms, associated to the edge physicochemical nature regarding the coordination imperfection or the chemical bonding. In contrast to those...

  13. Physicochemical parameters of Amazon Melipona honey

    Ligia Bicudo de Almeida-Muradian; Adriana Hitomi Matsuda; Deborah Helena Markowicz Bastos

    2007-01-01

    Stingless bees produce a honey that is different from the Apis honey in terms of composition. There aren't enough data to establish quality control parameters for this product, mainly due to lack of research results. The aim of this work is to evaluate some physicochemical parameters that can be used for the characterization and for the quality control of the Meliponinae honey. Four different samples were collected in the Amazon region of Brazil in 2004 (Melipona compressipes manaoense bee an...

  14. Adaptive Lighting

    Petersen, Kjell Yngve; Søndergaard, Karin; Kongshaug, Jesper

    2015-01-01

    Adaptive LightingAdaptive lighting is based on a partial automation of the possibilities to adjust the colour tone and brightness levels of light in order to adapt to people’s needs and desires. IT support is key to the technical developments that afford adaptive control systems. The possibilities offered by adaptive lighting control are created by the ways that the system components, the network and data flow can be coordinated through software so that the dynamic variations are controlled i...

  15. [Physico-chemical profiling of centrally acting molecules for prediction of pharmacokinetic properties].

    Deák, Katalin

    2008-01-01

    Physico-chemical profiling is a fundamental tool at the early stage of drug discovery in screening drug-like candidates. Complex physico-chemical profiling, including molecular properties such as solubility, ionization, lipophilicity and permeability, has been found to be of predictive power in ADME (absorption, distribution, metabolism, elimination). In the present thesis work, the physico-chemical properties of centrally acting compounds were investigated. We determined the protonation constants (K), the partition coeffitient in octanol/water (Poct) and cyclohexane/water (Pch) systems of antidepressive sertraline and 15 antipsychotic piperidine and piperazine derivatives and calculated the delta logP (logPoct-logPch) values of the molecules. Due to the poor water solubility of the compounds potentiometry using the "co-solvent" technique was applied for the determination of the protonation constants. The logP values were measured by the dual-phase potentiometric titration in octanol/water system and the traditional shake-flask method was used in cyclohexane/water system. Highly precise physico-chemical data were obtained by these validated methods. The relationship between the structure of the molecules and the physico-chemical data was investigated. The pharmacokinetic properties of the compounds were predicted by the physico-chemical parameters. Linear relationship has been found between the brain penetration characterized by the logBB values and the delta logP values. The validity of the equation was controlled by the delta logP and the logBB values of sertraline. PMID:18986088

  16. High resolution adaptive optics imaging complements standard spectral domain optical coherent tomography in retinal diseases with micro-structural details: a case series

    Gibran Syed Khurshid

    2016-01-01

    Full Text Available Purpose: To evaluate if high resolution adaptive optics confocal scanning laser ophthalmoscopy (AO-SLO can be used as an adjunct complementary diagnostic tool to spectral domain optical coherent tomography (SD-OCT in characterizing three macular diseases: rod-cone dystrophy, acute retinal pigment epitheliitis (Krill’s disease, and occult macular dystrophy. Methods: As part of a complete clinical examination, each patient was subjected to color fundus pictures, multimodal imaging scans with Heidelberg SpectralisTM and high resolution retinal images with a custom built adaptive optics scanning laser ophthalmolscope (AO-SLO. The registered AO-SLO images were averaged to improve the signal to noise ratio and used to generate larger photoreceptor mosaics. Results: AO-SLO mosaics for all three conditions showed distinct, characteristic disruptions of the photoreceptors in areas that corresponded to the abnormalities observed on fundus photography and SD-OCT scans. Conclusions: AO-SLO defined fine structural changes associated with retinal pathology at the photoreceptor level that could not be achieved using standard diagnostic methods. A combination of adaptive optics scanning laser ophthalmoscopy (AO-SLO and SD-OCT provided views of the retina with enhanced lateral and axial resolution. High-resolution, ultra-structural details of the retina may provide additional insights into the disease etiology, progression and management of patients with vision threatening macular diseases.

  17. Liposomes for Drug Delivery : from Physico-chemical Studies to Applications

    Bergstrand, Nill

    2003-01-01

    Physico-chemical characterisation of structure and stability of liposomes intended for drug delivery is the central issue in this thesis. In addition, targeted liposomes to be used in boron neutron capture therapy (BNCT) were developed. Lysolipids and fatty acids are products formed upon hydrolysis of PC-lipids. The aggregate structure formed upon mixing lysolipids, fatty acids and EPC were characterised by means of cryo-TEM. A relatively monodisperse population of unilamellar liposomes was d...

  18. Physicochemical parameters for computerized simulation of oxide melt-crystallization products system

    The results on application of physicochemical models of electron structure of oxide and metal melts for studying the phase equilibria by crystallization are considered. Two groups of oxide systems, including the ZrO2(HgO2)-Y2O3-Al2O3(CaO)-type one, are studied. The possibility of forecasting the primary phase structure through the interatomic interaction characteristics in the ordered and disordered oxide systems is shown

  19. In-Flight Suppression of an Unstable F/A-18 Structural Mode Using the Space Launch System Adaptive Augmenting Control System

    VanZwieten, Tannen S.; Gilligan, Eric T.; Wall, John H.; Miller, Christopher J.; Hanson, Curtis E.; Orr, Jeb S.

    2015-01-01

    NASA's Space Launch System (SLS) Flight Control System (FCS) includes an Adaptive Augmenting Control (AAC) component which employs a multiplicative gain update law to enhance the performance and robustness of the baseline control system for extreme off-nominal scenarios. The SLS FCS algorithm including AAC has been flight tested utilizing a specially outfitted F/A-18 fighter jet in which the pitch axis control of the aircraft was performed by a Non-linear Dynamic Inversion (NDI) controller, SLS reference models, and the SLS flight software prototype. This paper describes test cases from the research flight campaign in which the fundamental F/A-18 airframe structural mode was identified using post-flight frequency-domain reconstruction, amplified to result in closed loop instability, and suppressed in-flight by the SLS adaptive control system.

  20. In-Flight Suppression of a Destabilized F/A-18 Structural Mode Using the Space Launch System Adaptive Augmenting Control System

    Wall, John H.; VanZwieten, Tannen S.; Gilligan, Eric T.; Miller, Christopher J.; Hanson, Curtis E.; Orr, Jeb S.

    2015-01-01

    NASA's Space Launch System (SLS) Flight Control System (FCS) includes an Adaptive Augmenting Control (AAC) component which employs a multiplicative gain update law to enhance the performance and robustness of the baseline control system for extreme off nominal scenarios. The SLS FCS algorithm including AAC has been flight tested utilizing a specially outfitted F/A-18 fighter jet in which the pitch axis control of the aircraft was performed by a Non-linear Dynamic Inversion (NDI) controller, SLS reference models, and the SLS flight software prototype. This paper describes test cases from the research flight campaign in which the fundamental F/A-18 airframe structural mode was identified using frequency-domain reconstruction of flight data, amplified to result in closed loop instability, and suppressed in-flight by the SLS adaptive control system.

  1. Adaptive Lagrange finite element methods for high precision vibrations and piezoelectric acoustic wave compu- tations in SMT structures and plates with nano interfaces

    2002-01-01

    This paper discusses the validity of (adaptive) Lagrange generalized plain finite element method(FEM) and plate element method for accurate analysis of acoustic waves in multi-layered piezoelectric structures with tiny interfaces between metal electrodes and surface mounted piezoelectric substrates. We have come to conclusion that the quantitative relationships between the acoustic and electric fields in a piezoelectric structure can be accurately determined through the proposed finite element methods. The higher-order Lagrange FEM proposed for dynamic piezoelectric computation is proved to be very accurate (prescribed relative error 0.02%-0.04%) and a great improvement in convergence accuracy over the higher order Mindlin plate element method for piezoelectric structural analysis due to the assumptions and corrections in the plate theories. The converged Lagrange finite element methods are compared with the plate element methods and the computed results are in good agreement with available exact and experimental data. The adaptive Lagrange finite element methods and a new FEA computer program developed for macro- and micro-scale analyses are reviewed, and recently extended with great potential to high-precision nano-scale analysis in this paper and the similarities between piezoelectric and seismic wave propagations in layered structures and plates are stressed.

  2. Adaptation of topology optimization on truck-structure; Kinshitsukaho ni yoru iso saitekika shuho no truck kozo eno tekiyo

    Tachibana, H.; Kojima, A.; Chiba, S. [Mitsubishi Motors Corp., Tokyo (Japan)

    1997-10-01

    An optimization using the homogenization method has been applied to a truck-structure on the concept design stage. A truck-structure is grouped into 3 classes (thin plate structure , thick plate structure and solid structure), then example, effectiveness and method for the application for the purpose of weight reduction , high rigidity and high eigen-frequency are introduced. 3 refs., 24 figs., 1 tab.

  3. Using Artificial Intelligence to Retrieve the Optimal Parameters and Structures of Adaptive Network-Based Fuzzy Inference System for Typhoon Precipitation Forecast Modeling

    Chien-Lin Huang

    2015-01-01

    Full Text Available This study aims to construct a typhoon precipitation forecast model providing forecasts one to six hours in advance using optimal model parameters and structures retrieved from a combination of the adaptive network-based fuzzy inference system (ANFIS and artificial intelligence. To enhance the accuracy of the precipitation forecast, two structures were then used to establish the precipitation forecast model for a specific lead-time: a single-model structure and a dual-model hybrid structure where the forecast models of higher and lower precipitation were integrated. In order to rapidly, automatically, and accurately retrieve the optimal parameters and structures of the ANFIS-based precipitation forecast model, a tabu search was applied to identify the adjacent radius in subtractive clustering when constructing the ANFIS structure. The coupled structure was also employed to establish a precipitation forecast model across short and long lead-times in order to improve the accuracy of long-term precipitation forecasts. The study area is the Shimen Reservoir, and the analyzed period is from 2001 to 2009. Results showed that the optimal initial ANFIS parameters selected by the tabu search, combined with the dual-model hybrid method and the coupled structure, provided the favors in computation efficiency and high-reliability predictions in typhoon precipitation forecasts regarding short to long lead-time forecasting horizons.

  4. Organizational Leadership Assessment in Servant Organizations: Adaptation for Turkish Culture, Language Validity and Examination of Factor Structure

    KAHVECİ, Hakkı; Ahmet AYPAY

    2012-01-01

    The purpose of this study is to adapt Laub’s (1999) Organizational Leadership Assessment in Servant Organizations to Turkish literaturate on servant leadership. Validity and reliability analyzes were conducted. The original instrument included 60 questions and six dimensions. Data was collected from primaryschool teachers in Eskişehir and Balıkesir. Descriptive statistics and exploratory factor analyis were used to analyze the data. Resulst indicated that, a valid and relaible instrument incl...

  5. Adaptive skills

    Staša Stropnik; Jana Kodrič

    2013-01-01

    Adaptive skills are defined as a collection of conceptual, social and practical skills that are learned by people in order to function in their everyday lives. They include an individual's ability to adapt to and manage her or his surroundings to effectively function and meet social or community expectations. Good adaptive skills promote individual's independence in different environments, whereas poorly developed adaptive skills are connected to individual's dependency and with g...

  6. A new adaptive algorithm for automated feature extraction in exponentially damped signals for health monitoring of smart structures

    Qarib, Hossein; Adeli, Hojjat

    2015-12-01

    In this paper authors introduce a new adaptive signal processing technique for feature extraction and parameter estimation in noisy exponentially damped signals. The iterative 3-stage method is based on the adroit integration of the strengths of parametric and nonparametric methods such as multiple signal categorization, matrix pencil, and empirical mode decomposition algorithms. The first stage is a new adaptive filtration or noise removal scheme. The second stage is a hybrid parametric-nonparametric signal parameter estimation technique based on an output-only system identification technique. The third stage is optimization of estimated parameters using a combination of the primal-dual path-following interior point algorithm and genetic algorithm. The methodology is evaluated using a synthetic signal and a signal obtained experimentally from transverse vibrations of a steel cantilever beam. The method is successful in estimating the frequencies accurately. Further, it estimates the damping exponents. The proposed adaptive filtration method does not include any frequency domain manipulation. Consequently, the time domain signal is not affected as a result of frequency domain and inverse transformations.

  7. Physicochemical bases of underground leaching process

    Physicochemical bases of uranium underground leaching (UL) from ores are considered. The UL process is generally characterized. Advantages and disadvantages of acidic and carbonate leaching techniques are discussed. UO2 oxidation and solution using oxygen and MnO2 as oxidizers in the presence of 3+Fe catalysts and nitrogen oxides, are considered. The data on the solvent interaction with ore and enclosing rock components are given. The mechanisms and kinetic regularities of extracting uranium from ores with natural and artificial permeability are described as well as the mechanisms and kinetic regularities of the process of dissolved uranium absorption by ore-free rocks

  8. City snow's physicochemical property affects snow disposal

    Dovbysh, V. O.; Sharukha, A. V.; Evtin, P. V.; Vershinina, S. V.

    2015-10-01

    At the present day the industrial cities run into severe problem: fallen snow in a city it's a concentrator of pollutants and their quantity is constantly increasing by technology development. Pollution of snow increases because of emission of gases to the atmosphere by cars and factories. Large accumulation of polluted snow engenders many vexed ecological problems. That's why we need a new, non-polluting, scientifically based method of snow disposal. This paper investigates polluted snow's physicochemical property effects on snow melting. A distinctive feature of the ion accelerators with self-magnetically insulated diode is that there.

  9. Adaptive Finite Elements for Monolithic Fluid-StructureInteraction on a Prolongated Domain: Applied to an Heart Valve Simulation

    Wick, Thomas

    2011-01-01

    In this work, we apply a fluid-structure interaction method to a long axis heart valve simulation. Our method of choice is based on a monolithic coupling scheme for fluid-structure interaction, where the fluid equations are rewritten in the arbitrary Lagrangian Eulerian' framework. To prevent back-flow of waves in the structure due to its hyperbolic nature, a damped structure equation is solved on an artificial layer that prolongates the computational domain. This coupling is stable on th...

  10. Adaptive Lighting

    Petersen, Kjell Yngve; Søndergaard, Karin; Kongshaug, Jesper

    2015-01-01

    Adaptive Lighting Adaptive lighting is based on a partial automation of the possibilities to adjust the colour tone and brightness levels of light in order to adapt to people’s needs and desires. IT support is key to the technical developments that afford adaptive control systems. The possibilities...... offered by adaptive lighting control are created by the ways that the system components, the network and data flow can be coordinated through software so that the dynamic variations are controlled in ways that meaningfully adapt according to people’s situations and design intentions. This book discusses...... distributed differently into an architectural body. We also examine what might occur when light is dynamic and able to change colour, intensity and direction, and when it is adaptive and can be brought into interaction with its surroundings. In short, what happens to an architectural space when artificial...

  11. Organizational Leadership Assessment in Servant Organizations: Adaptation for Turkish Culture, Language Validity and Examination of Factor Structure

    Hakkı KAHVECİ

    2012-06-01

    Full Text Available The purpose of this study is to adapt Laub’s (1999 Organizational Leadership Assessment in Servant Organizations to Turkish literaturate on servant leadership. Validity and reliability analyzes were conducted. The original instrument included 60 questions and six dimensions. Data was collected from primaryschool teachers in Eskişehir and Balıkesir. Descriptive statistics and exploratory factor analyis were used to analyze the data. Resulst indicated that, a valid and relaible instrument included 54 questions with two dimensions.

  12. Physicochemical Properties of Palm Kernel Oil

    Amira P. Olaniyi

    2014-09-01

    Full Text Available Physicochemical analyses were carried out on palm kernel oil (Adin and the following results were obtained: Saponification value; 280.5±56.1 mgKOH/g, acid value; 2.7±0.3 mg KOH/g, Free Fatty Acid (FFA; 1.35±0.15 KOH/g, ester value; 277.8±56.4 mgKOH/g, peroxide value; 14.3±0.8 mEq/kg; iodine value; 15.86±4.02 mgKOH/g, Specific Gravity (S.G value; 0.904, refractive index; 1.412 and inorganic materials; 1.05%. Its odour and colour were heavy burnt smell and burnt brown, respectively. These values were compared with those obtained for groundnut and coconut oils. It was found that the physico-chemical properties of palm kernel oil are comparable to those of groundnut and coconut oils except for the peroxide value (i.e., 14.3±0.8 mEq which was not detectable in groundnut and coconut oils. Also the odour of both groundnut and coconut oils were pleasant while that of the palm kernel oil was not as pleasant (i.e., heavy burnt smell.

  13. Pharmacognostical and physicochemical evaluation of Agasti leaf.

    Yadav, Pramod; Harisha, C R; Prajapati, P K

    2010-10-01

    Sesbania grandiflora (L.) Pers., commonly known as Agasti, is widely used in Ayurveda for the treatment of diseases and for processing of various formulations in Rasashastra. It is used for its astringent, antihistaminic, anxiolytic, anticonvulsive and febrifugal activities. Moreover, because of its edible nature, the leaves and pods are used as flavoring items in the cuisine of South India. A detailed investigation of fresh and powder of leaves of Agasti was carried out. The diagnostic characters of this plant include stomatal characters, presence of resins, oil globules, appressed epidermal hair and mucilage cells. Physicochemical studies revealed loss on drying (0.6%), total ash (10.75%), acid insoluble ash (0.045%), alcohol-soluble extractive (21.7%), and water-soluble extractive (30.72%). Preliminary analysis for the presence of various functional groups revealed the presence of alkaloids, saponins, phenols and proteins. Thin layer chromatographic study of the alcoholic extract showed the presence of five, six and seven spots in short UV, long UV and after spraying developing reagent, respectively. The information generated by this particular study will provide relevant pharmacognostical and physicochemical data needed for proper identification and authentication of leaves of this particular species. PMID:21455451

  14. Physicochemical parameters of Amazon Melipona honey

    Ligia Bicudo de Almeida-Muradian

    2007-06-01

    Full Text Available Stingless bees produce a honey that is different from the Apis honey in terms of composition. There aren't enough data to establish quality control parameters for this product, mainly due to lack of research results. The aim of this work is to evaluate some physicochemical parameters that can be used for the characterization and for the quality control of the Meliponinae honey. Four different samples were collected in the Amazon region of Brazil in 2004 (Melipona compressipes manaoense bee and Melipona seminigra merribae bee. Honey analyses were performed as described by the official methods. The mean results were: moisture (30.13%, pH (3.65, acidity (24.57 mEq/kg, water activity (0.75, fructose (31.91%, glucose (29.30% and sucrose (0.19%. These results reinforce the need for a specific regulation for stingless bee honey. This will only be feasible when enough data is available to establish upper and lower limits for the physicochemical parameters used for quality control.

  15. Natural selection of adaptive mutations in non-structural genes increases trans-encapsidation of hepatitis C virus replicons lacking envelope protein genes.

    Fournier, Carole; Helle, François; Descamps, Véronique; Morel, Virginie; François, Catherine; Dedeurwaerder, Sarah; Wychowski, Czeslaw; Duverlie, Gilles; Castelain, Sandrine

    2013-05-01

    A trans-packaging system for hepatitis C virus (HCV) replicons lacking envelope glycoproteins was developed. The replicons were efficiently encapsidated into infectious particles after expression in trans of homologous HCV envelope proteins under the control of an adenoviral vector. Interestingly, expression in trans of core or core, p7 and NS2 with envelope proteins did not enhance trans-encapsidation. Expression of heterologous envelope proteins, in the presence or absence of heterologous core, p7 and NS2, did not rescue single-round infectious particle production. To increase the titre of homologous, single-round infectious particles in our system, successive cycles of trans-encapsidation and infection were performed. Four cycles resulted in a 100-fold increase in the yield of particles. Sequence analysis revealed a total of 16 potential adaptive mutations in two independent experiments. Except for a core mutation in one experiment, all the mutations were located in non-structural regions mainly in NS5A (four in domain III and two near the junction with the NS5B gene). Reverse genetics studies suggested that D2437A and S2443T adaptive mutations, which are located at the NS5A-B cleavage site did not affect viral replication, but enhanced the single-round infectious particles assembly only in trans-encapsidation model. In conclusion, our trans-encapsidation system enables the production of HCV single-round infectious particles. This system is adaptable and can positively select variants. The adapted variants promote trans-encapsidation and should constitute a valuable tool in the development of replicon-based HCV vaccines. PMID:23288424

  16. Freshwater prokaryote and virus communities can adapt to a controlled increase in salinity through changes in their structure and interactions

    Marine, Combe; Thierry, Bouvier; Olivier, Pringault; Emma, Rochelle-Newall; Corinne, Bouvier; Martin, Agis; The Thu, Pham; Jean-Pascal, Torreton; Van Thuoc, Chu; Bettarel, Yvan

    2013-11-01

    Little information exists on the ecological adaptive responses of riverine microorganisms to the salinity changes that typically occur in transitional waters. This study examined the precise effects of a gradual increase in salinity (+3 units per day for 12 days) on freshwater virus and prokaryote communities collected in the Red River Delta (northern Vietnam). The abundance, activity, morphology and diversity of both communities were examined along this simulated salinity gradient (0-36). Three main successive ecological stages were observed: (1) a continuous decline in prokaryotic and viral abundance from the start of the salinization process up to salinity 12-15 together with a strong decrease in the proportion of active cells, (2) a shift in both community compositions (salinity 9-15) and (3) a marked prevalence of lysogenic over lytic cycles up to salinity 21 followed by a collapse of both types of viral infection. Finally, after salinity 21, and up to seawater salinities (i.e. 36) the prokaryotic community showed multiple signs of recovery with their abundance and function even reaching initial levels. These results suggest that most of the physiological and phylogenetic changes that occurred within the salinity range 10-20 seemed to favor the installation of osmotically adapted prokaryotes accompanied by a specific cortege of viral parasites which might both be able to survive and even proliferate in saltwater conditions.

  17. Physicochemical characterizations of nano-palm oil fuel ash

    Palm Oil Fuel Ash (POFA) is known as a good supplementary cementing material due to its siliceous-rich content. The application of nanotechnology in the pozzolanic materials could invent new functions in the efficiency of physical and chemical properties of materials. Thus, the present study aims to generate nano-sized POFA and characterize the physicochemical properties of nano-palm oil fuel ash (nPOFA). The nPOFA was prepared by mechanically grinding micro POFA using a high intensity ball milling for 6 hours. The physicochemical properties of nPOFA were characterized via X-Ray Fluoresence (XRF), Scanning Emission microscopy- Energy Dispersive X-Ray (SEM-EDX), Transmission Electron Microscope (TEM) and X-Ray Diffraction (XRD). The particle size of nPOFA acquired from TEM analysis was in the range of 20 nm to 90 nm, while the average crystallite size calculated from XRD diffractogram was 61.5 nm. The resulting nPOFA has a BET surface area of 145.35 m2/g, which is more than 85% increment in surface area compared to micro-sized POFA. The morphology and elemental studies showed the presence of spherical as well as irregularly shaped and fine nPOFA particles contains with high silicon content. The presence of α-quartz as the major phase of the nPOFA was identified through XRD analysis. The study concludes that nPOFA has the potential as a supplementary cementing material due to the high silica content, high surface area and the unique behaviors of nano-structured particles

  18. Physicochemical characterizations of nano-palm oil fuel ash

    Rajak, Mohd Azrul Abdul, E-mail: azrulrajak88@gmail.com [Department of Chemistry, Faculty of Science, Universiti Teknologi Malaysia, 81310 UTM Johor Bahru (Malaysia); Preparatory Centre of Science and Technology, Universiti Malaysia Sabah, Jalan UMS, 88400, Kota Kinabalu, Sabah (Malaysia); Majid, Zaiton Abdul, E-mail: zaiton@kimia.fs.utm.my [Department of Chemistry, Faculty of Science, Universiti Teknologi Malaysia, 81310 UTM Johor Bahru (Malaysia); Ismail, Mohammad [Department of Structure and Material, Faculty of Civil Engineering, Universiti Teknologi Malaysia, 81310 UTM Johor Bahru (Malaysia)

    2015-07-22

    Palm Oil Fuel Ash (POFA) is known as a good supplementary cementing material due to its siliceous-rich content. The application of nanotechnology in the pozzolanic materials could invent new functions in the efficiency of physical and chemical properties of materials. Thus, the present study aims to generate nano-sized POFA and characterize the physicochemical properties of nano-palm oil fuel ash (nPOFA). The nPOFA was prepared by mechanically grinding micro POFA using a high intensity ball milling for 6 hours. The physicochemical properties of nPOFA were characterized via X-Ray Fluoresence (XRF), Scanning Emission microscopy- Energy Dispersive X-Ray (SEM-EDX), Transmission Electron Microscope (TEM) and X-Ray Diffraction (XRD). The particle size of nPOFA acquired from TEM analysis was in the range of 20 nm to 90 nm, while the average crystallite size calculated from XRD diffractogram was 61.5 nm. The resulting nPOFA has a BET surface area of 145.35 m{sup 2}/g, which is more than 85% increment in surface area compared to micro-sized POFA. The morphology and elemental studies showed the presence of spherical as well as irregularly shaped and fine nPOFA particles contains with high silicon content. The presence of α-quartz as the major phase of the nPOFA was identified through XRD analysis. The study concludes that nPOFA has the potential as a supplementary cementing material due to the high silica content, high surface area and the unique behaviors of nano-structured particles.

  19. Physicochemical characterizations of nano-palm oil fuel ash

    Rajak, Mohd Azrul Abdul; Majid, Zaiton Abdul; Ismail, Mohammad

    2015-07-01

    Palm Oil Fuel Ash (POFA) is known as a good supplementary cementing material due to its siliceous-rich content. The application of nanotechnology in the pozzolanic materials could invent new functions in the efficiency of physical and chemical properties of materials. Thus, the present study aims to generate nano-sized POFA and characterize the physicochemical properties of nano-palm oil fuel ash (nPOFA). The nPOFA was prepared by mechanically grinding micro POFA using a high intensity ball milling for 6 hours. The physicochemical properties of nPOFA were characterized via X-Ray Fluoresence (XRF), Scanning Emission microscopy- Energy Dispersive X-Ray (SEM-EDX), Transmission Electron Microscope (TEM) and X-Ray Diffraction (XRD). The particle size of nPOFA acquired from TEM analysis was in the range of 20 nm to 90 nm, while the average crystallite size calculated from XRD diffractogram was 61.5 nm. The resulting nPOFA has a BET surface area of 145.35 m2/g, which is more than 85% increment in surface area compared to micro-sized POFA. The morphology and elemental studies showed the presence of spherical as well as irregularly shaped and fine nPOFA particles contains with high silicon content. The presence of α-quartz as the major phase of the nPOFA was identified through XRD analysis. The study concludes that nPOFA has the potential as a supplementary cementing material due to the high silica content, high surface area and the unique behaviors of nano-structured particles.

  20. Thermodynamic description of Beta amyloid formation using physicochemical scales and fractal bioinformatic scales.

    Phillips, J C

    2015-05-20

    Protein function depends on both protein structure and amino acid (aa) sequence. Here we show that modular features of both structure and function can be quantified economically from the aa sequences alone for the small (40,42 aa) plaque-forming (aggregative) amyloid beta fragments. Some edge and center features of the fragments are predicted. Bioinformatic scales based on β strand formation propensities and the thermodynamically second order fractal hydropathicity scale based on evolutionary optimization (self-organized criticality) are contrasted with the standard first order physicochemical scale based on complete protein (water-air) unfolding. The results are consistent with previous studies of these physicochemical factors that show that aggregative properties, even of beta fragments, are driven primarily by near-equilibrium hydropathic forces. PMID:25702750

  1. Physico-chemical study of coating plasma duplex alumina/hydroxyapatite for medical applications relation elaboration/structure/properties(dissolution/adherence/residual constraints); Etude physico-chimique de depots plasma duplex alumine/hydroxyapatite pour applications medicales relations elaboration/structure/proprietes (dissolution/adherence/contraintes residuelles)

    Demonet, N

    1998-11-19

    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.)

  2. Physicochemical properties and transport of steroids across Caco-2 cells

    Faassen, F.; Kelder, J.; Lenders, J.; Onderwater, R.; Vromans, H.

    2003-01-01

    Purpose. The purpose of this work was to study the relevant physicochemical properties for the absorption of steroids. Methods. Various physicochemical properties of steroids were calculated (molecular weight, ClogP, static polar surface area [PSA], etc.). Within this series of steroids, different p

  3. Robust Sensorless Control for Induction Motor Drives Fed by a Matrix Converter with Variable Structure Model Reference Adaptive

    Kim, Won-Sang; Lee, Kyo-Beum; Huh, Sunghoi;

    2007-01-01

    This paper presents a new robust sensorless control system for high performance induction motor drives fed by a matrix converter with variable structure. The lumped disturbances such as parameter variation and load disturbance of the system are estimated by a variable structure approach based...

  4. Crystal structure analysis of a glycosides hydrolase family 42 cold-adapted ß-galactosidase from Rahnella sp. R3

    The ß-galactosidase isolated from a psychrotrophic bacterium, Rahnella sp. R3 (R-ß-Gal), exhibits high activity at low temperature. R-ß-Gal is a member of the glycoside hydrolases family 42 (GH42), and forms a 225 kDa trimeric structure in solution. The X-ray crystal structure of R-ß-Gal was determi...

  5. Adaptive Lighting

    Petersen, Kjell Yngve; Søndergaard, Karin; Kongshaug, Jesper

    2015-01-01

    Adaptive Lighting Adaptive lighting is based on a partial automation of the possibilities to adjust the colour tone and brightness levels of light in order to adapt to people’s needs and desires. IT support is key to the technical developments that afford adaptive control systems. The possibilities...... offered by adaptive lighting control are created by the ways that the system components, the network and data flow can be coordinated through software so that the dynamic variations are controlled in ways that meaningfully adapt according to people’s situations and design intentions. This book discusses...... the investigations of lighting scenarios carried out in two test installations: White Cube and White Box. The test installations are discussed as large-scale experiential instruments. In these test installations we examine what could potentially occur when light using LED technology is integrated and...

  6. Cyclodextrin Inclusion Complex to Improve Physicochemical Properties of Herbicide Bentazon: Exploring Better Formulations

    Claudia Yáñez; Paulina Cañete-Rosales; Juan Pablo Castillo; Nicole Catalán; Tomás Undabeytia; Esmeralda Morillo

    2012-01-01

    The knowledge of the host-guest complexes using cyclodextrins (CDs) has prompted an increase in the development of new formulations. The capacity of these organic host structures of including guest within their hydrophobic cavities, improves physicochemical properties of the guest. In the case of pesticides, several inclusion complexes with cyclodextrins have been reported. However, in order to explore rationally new pesticide formulations, it is essential to know the effect of cyclodextrins ...

  7. Non-covalent interactions and physico-chemical properties of small biological systems : theoretical approaches

    Riffet, Vanessa

    2014-01-01

    The three-dimensional structure and physico-chemical properties of biomolecules such as peptides are not only governed by their elementary composition but also various non-covalent intra-and inter-molecular interactions. The characterization, measurement and effects of these interactions are currently at the center of many researches at the interface between biology and physical chemistry. In this context, the aim of our thesis is a better understanding of these interactions in biomolecules a...

  8. Sensory and physicochemical evaluation of low-fat chicken mortadella with added native and modified starches

    Prestes, R. C.; Silva, L. B.; Torri, A. M. P.; Kubota, E. H.; C.S. ROSA; S.S. ROMAN; Kempka, A. P.; I.M. DEMIATE

    2014-01-01

    The objective of this work was to evaluate the effect of adding different starches (native and modified) on the physicochemical, sensory, structural and microbiological characteristics of low-fat chicken mortadella. Two formulations containing native cassava and regular corn starch, coded CASS (5.0 % of cassava starch) and CORN (5.0 % of regular corn starch), and one formulation produced with physically treated starch coded as MOD1 (2.5 % of Novation 2300) and chemically modified starch coded...

  9. Adaptive skills

    Staša Stropnik

    2013-02-01

    Full Text Available Adaptive skills are defined as a collection of conceptual, social and practical skills that are learned by people in order to function in their everyday lives. They include an individual's ability to adapt to and manage her or his surroundings to effectively function and meet social or community expectations. Good adaptive skills promote individual's independence in different environments, whereas poorly developed adaptive skills are connected to individual's dependency and with greater need for control and help with everyday tasks. Assessment of adaptive skills is often connected to assessment of intellectual disability, due to the reason that the diagnosis of intellectual disability includes lower levels of achievements on standardized tests of intellectual abilities as well as important deficits in adaptive skills. Assessment of adaptive behavior is a part of standard assessment battery with children and adults with different problems, disorders or disabilities that affect their everyday functioning. This contribution also presents psychometric tools most regularly used for assessment of adaptive skills and characteristics of adaptive skills with individual clinical groups.

  10. ADAPT Dataset

    National Aeronautics and Space Administration — Advanced Diagnostics and Prognostics Testbed (ADAPT) Project Lead: Scott Poll Subject Fault diagnosis in electrical power systems Description The Advanced...

  11. Physicochemical state of the spent fuel leaving the reactors

    This report focuses on the current knowledge, updated at the end of 1999, about the physicochemical state of the fuels leaving light water reactors, and particularly pressurized water reactors. Lessons are withdrawn from it making it possible to determine the points which require a necessary deepening of the data and coherence of interpretations. Lastly, evolution of the sailed fuel rod as well as the potential availability of gases and volatile fission products, during a secular storage or of a multi-millennium disposal, are the subject of an attempt at forecast. Accessible data in the scientific literature, or those acquired at the CEA, are particularly numerous. Their analysis and their synthesis are joined together to constitute a collection of references intended to the specialists in nuclear fuel and for all those which contribute to the reflexion on the storage or final disposal of the irradiated fuel. This memory is structured in ten chapters. The last chapter makes it possible to retain on some pages, the essential lessons of this study. Chapter I: Introduction; Chapter II: Characteristics of assemblies and fuels before irradiation; Chapter III: Transformations in reactor; Chapter IV: State of rods leaving the reactor; Chapter V: State of pellets; Chapter VI: Chemical and structural composition of the fuel; Chapter VII: Fuel fragmentation and density; Chapter VIII: Phenomena at the pellet periphery. Formation, characteristics and structure of the rim.Chemical interaction between pellet and cladding; Chapter IX: Location of fission gases and volatile fission products; Chapter X: Review, lessons and predictions. (authors)

  12. Adaptive Neural Control for a Class of Low-triangular-structured Nonlinear Systems with H-∞Performance Analysis

    WANG Hui-feng; DU Hong-bin

    2008-01-01

    In this paper,a neural-network-based variable structure control scheme is presented for a class of nonlinear systems with a general low triangular structure.The proposed variable structure controller is proved to be C1,thus can be applied for backstepping design,which has extended the scope of previous nonlinear systems in the form of strict-feedback and pure-feedback.With the help of neural network approximator,H-oo performance analysis of stability is given.The effectiveness of proposed control law is verified via simulation.

  13. Theory of adaptive adjustment

    Weihong Huang

    2000-01-01

    Full Text Available Conventional adaptive expectation as a mechanism of stabilizing an unstable economic process is reexamined through a generalization to an adaptive adjustment framework. The generic structures of equilibria that can be stabilized through an adaptive adjustment mechanism are identified. The generalization can be applied to a broad class of discrete economic processes where the variables interested can be adjusted or controlled directly by economic agents such as in cobweb dynamics, Cournot games, Oligopoly markets, tatonnement price adjustment, tariff games, population control through immigration etc.

  14. A vision-based system for measuring the displacements of large structures: Simultaneous adaptive calibration and full motion estimation

    Santos, C. Almeida; Costa, C. Oliveira; Batista, J.

    2016-05-01

    The paper describes a kinematic model-based solution to estimate simultaneously the calibration parameters of the vision system and the full-motion (6-DOF) of large civil engineering structures, namely of long deck suspension bridges, from a sequence of stereo images captured by digital cameras. Using an arbitrary number of images and assuming a smooth structure motion, an Iterated Extended Kalman Filter is used to recursively estimate the projection matrices of the cameras and the structure full-motion (displacement and rotation) over time, helping to meet the structure health monitoring fulfilment. Results related to the performance evaluation, obtained by numerical simulation and with real experiments, are reported. The real experiments were carried out in indoor and outdoor environment using a reduced structure model to impose controlled motions. In both cases, the results obtained with a minimum setup comprising only two cameras and four non-coplanar tracking points, showed a high accuracy results for on-line camera calibration and structure full motion estimation.

  15. Banana cultivars, cultivation practices, and physicochemical properties.

    Arvanitoyannis, I S; Mavromatis, A

    2009-02-01

    The physicochemical (pH, texture, Vitamin C, ash, fat, minerals) and sensory properties of banana were correlated with the genotype and growing conditions. Minerals in particular were shown to discriminate banana cultivars of different geographical origin quite accurately. Another issue relates to the beneficial properties of bananas both in terms of the high dietary fiber and antioxidant compounds, the latter being abundant in the peel. Therefore, banana can be further exploited for extracting several important components such as starch, and antioxidant compounds which can find industrial and pharmaceutical applications. Finally, the various storage methodologies were presented with an emphasis on Modified Atmosphere Packaging which appears to be one of the most promising of technologies. PMID:18989831

  16. Physicochemical Characteristic of Malt Vinegar with Spices

    Andrei Borşa

    2015-11-01

    Full Text Available The malt vinegar is very popular in England, being prepared from barley malt using a method resembling to the one used to produce the wine vinegar. It has a strong taste and a medium acidity. Regarding the fact that it is not very common in Romania, the aim of the study was flavouring the malt vinegar with seasoning plants for a high concentration of antioxidants, flavour and also for making it more popular amongst consumers. Two types of flavoured malt vinegar were obtained, one of them with turmeric and the other one with rosemary, pepper and grain mustard. In order to characterize the new products, several physicochemical analyses were conducted (antioxidant capacity, total extract and acidity. 

  17. Physicochemical Properties of Palm Kernel Oil

    Amira P. Olaniyi; O.O. Babalola; Oyediran A. Mary

    2014-01-01

    Physicochemical analyses were carried out on palm kernel oil (Adin) and the following results were obtained: Saponification value; 280.5±56.1 mgKOH/g, acid value; 2.7±0.3 mg KOH/g, Free Fatty Acid (FFA); 1.35±0.15 KOH/g, ester value; 277.8±56.4 mgKOH/g, peroxide value; 14.3±0.8 mEq/kg; iodine value; 15.86±4.02 mgKOH/g, Specific Gravity (S.G) value; 0.904, refractive index; 1.412 and inorganic materials; 1.05%. Its odour and colour were heavy burnt smell and burnt brown, respectively. These va...

  18. Endoglucanase Peripheral Loops Facilitate Complexation of Glucan Chains on Cellulose via Adaptive Coupling to the Emergent Substrate Structures

    Lin, Yuchun; Beckham, Gregg T.; Himmel, Michael E.; Crowley, Michael F.; Chu, Jhih-wei

    2013-09-19

    We examine how the catalytic domain of a glycoside hydrolase family 7 endoglucanase catalytic domain (Cel7B CD) facilitates complexation of cellulose chains from a crystal surface. With direct relevance to the science of biofuel production, this problem also represents a model system of biopolymer processing by proteins in Nature. Interactions of Cel7B CD with a cellulose microfibril along different paths of complexation are characterized by mapping the atomistic fluctuations recorded in free-energy simulations onto the parameters of a coarse-grain model. The resulting patterns of protein-biopolymer couplings also uncover the sequence signatures of the enzyme in peeling off glucan chains from the microfibril substrate. We show that the semiopen active site of Cel7B CD exhibits similar barriers and free energies of complexation over two distinct routes; namely, scooping of a chain into the active-site cleft and threading from the chain end into the channel. On the other hand, the complexation energetics strongly depends on the surface packing of the targeted chain and the resulting interaction sites with the enzyme. A revealed principle is that Cel7B CD facilitates cellulose deconstruction via adaptive coupling to the emergent substrate. The flexible, peripheral segments of the protein outside of the active-site cleft are able to accommodate the varying features of cellulose along the simulated paths of complexation. The general strategy of linking physics-based molecular interactions to protein sequence could also be helpful in elucidating how other protein machines process biopolymers.

  19. Structure of Allozymatic Diversity of Ten Temperate and Adapted Exotic Breeding Populations of Maize (Zea mays L.)

    ZHENG Da-hao; YU Yang; WANG Zhen-ping; LI Yan-ru

    2009-01-01

    Ten temperate and adapted exotic breeding populations of maize were studied with electrophoretic techniques. Three isozyme systems coded by nine allozyme loci were used for evaluating the genetic variability within and among populations.The results revealed that 78.57% of allozyme loci were polymorphic. Low allelic variation with a mean number of 1.84 alleles per locus per population was detected. But, these populations still maintained higher level of heterozygosity;moreover, the exotic populations had greater gene diversity than the temperate populations. All the populations were non-panmictic with negative Wright's fixation indexes (-0.091- -0.424). The tropical BS16 was typified by maximum allelic richness, percent of polymorphic loci and heterozygosity. More than 93% of the gene diversity maintained within populations, and the genetic differentiation among populations was low (0.002-0.191). Multivariate analysis demonstrated that the tropical BS29 diverged from other populations in the reverse direction. The temperate BS9 and tropical BS 16 were divergent each other, and highly differentiated from other temperate and tropical populations, consequently, these two populations would be analogically postulated as potential germplasms to establish new heterotic groups for temperate maize breeding programs.

  20. Organic complexed superphosphates (CSP): physicochemical characterization and agronomical properties.

    Erro, Javier; Urrutia, Oscar; Baigorri, Roberto; Aparicio-Tejo, Pedro; Irigoyen, Ignacio; Storino, Francesco; Torino, Francesco; Mandado, Marcos; Yvin, Jean Claude; Garcia-Mina, Jose M

    2012-02-29

    A new type of superphosphate (organic complexed superphosphate (CSP)) has been developed by the introduction of organic chelating agents, preferably a humic acid (HA), into the chemical reaction of single superphosphate (SSP) production. This modification yielded a product containing monocalcium phosphate complexed by the chelating organic agent through Ca bridges. Theoretically, the presence of these monocalcium-phosphate-humic complexes (MPHC) inhibits phosphate fixation in soil, thus increasing P fertilizer efficiency. This study investigateed the structural and functional features of CSP fertilizers produced employing diverse HA with different structural features. To this end were used complementary analytical techniques: solid-phase ³¹P NMR, ¹³C NMR, laser-confocal microscopy, X-ray diffraction, and molecular modeling. Finally, the agronomical efficiency of four CSP have been compared with that of SSP as P sources for wheat plants grown in both alkaline and acidic soils in greenhouse pot trials under controlled conditions. The results obtained from the diverse analytical studies showed the formation of MPHC in CSP. Plant-soil studies showed that CSP products were more efficient than SSP in providing available phosphate for wheat plants cultivated in various soils with different physicochemical features. This fact is probably associated with the ability of CSP complexes to inhibit phosphate fixation in soil. PMID:22300509

  1. Chain conformational and physicochemical properties of fucoidans from sea cucumber.

    Xu, Xiaoqi; Xue, Changhu; Chang, Yaoguang; Wang, Jun; Jiang, Kunhao

    2016-11-01

    Although fucoidans from sea cucumber (SC-FUCs) have been proven as potential bioactive polysaccharides and functional food ingridents, their chain conformation and physicochemical properties were still poorly understood. This study investigated the chain conformation of fucoidans from sea cucumber Acaudina molpadioides (Am-FUC), Isostichopus badionotus (Ib-FUC) and Apostichopus japonicus (Aj-FUC), of which primary structure has been recently clarified. Chain conformation parameters demonstrated that studied SC-FUCs adopted random coil conformation in 150mM NaCl solution (pH 7.4). Based on the worm-like cylinder model and atomic force microscopy, the chain stiffness of SC-FUCs was further evaluated as Am-FUC≈Ib-FUC>Aj-FUC. It was suggested that the existence of branch structure increased the chain flexibility, while sulfated pattern exerted limited influence. SC-FUCs demonstrated shear-thinning rheological behavior and negative charge. Am-FUC possessed a higher thermostability than Ib-FUC and Aj-FUC. These results have important implications for understanding the molecular characteristics of SC-FUCs, which could facilitate their further application. PMID:27516290

  2. The genetic and structural basis of two distinct terminal side branch residues in stewartan and amylovoran exopolysaccharides and their potential role in host adaptation.

    Wang, Xiaolei; Yang, Fan; von Bodman, Susanne B

    2012-01-01

    Stewartan and amylovoran exopolysaccharide (EPS) produced by the plant pathogenic bacteria Pantoea stewartii and Erwinia amylovora are virulence factors in the cause of Stewart's vascular wilt and fire blight. The biosynthesis of amylovoran and stewartan is encoded by a set of homologous operons that have been partially characterized, although some annotations are solely on the basis of sequence homology. The major distinguishing features of these two EPS forms are the presence of a terminal pyruvate in amylovoran and glucose in stewartan, even though the gene systems to account for both are conserved and present in each bacterium. This study explores the genetic, structural and functional differences of amylovoran and stewartan, and their potential role in host adaptation. We report that the pyruvyl transferase gene in P. stewartii is non-functional, while the terminal glucosyl transferase is catalytically active. Conversely, in E. amylovora, the homologous glucosyl transferase activity appears to be relatively ineffective, while the pyruvyl transferase function predominates. We also show that the terminally pyruvylated versus glucosylated EPS require specific repeating unit translocases (Wzx). We discuss the evolutionary, functional and biological implications of the terminally pyruvylated and glucosylated polymers and their potential contribution to plant and insect host adaptation. PMID:22111898

  3. Adapting coastal structures to a moving relative sea level: Roman Time geoarchaeological evidence from Posillipo promontory (Naples, Italy).

    Aucelli, Pietro; Cinque, Aldo; Giordano, Francesco; Mattei, Gaia; Pappone, Gerardo; Rizzo, Angela

    2016-04-01

    The Posillipo promontory belongs to the southern periphery the active volcanic complex called Campi Flegrei. Especially the central caldera of CF is well known for offering a rich geoarchaeological record of the vertical ground movements it has been suffering since Roman times; which includes the ruins of Portus Julius (built in 37 BC) presently found between 10 and 5 m bsl and the Middle Ages Lithophaga perforations at about 7m asl on the marble columns of the Serapeo building (Morhange, 2006 and references therein). In order to better constraint the vertical movements suffered by the Posillipo promontory during the last two millennia, we selected three geoarcaeolgical coastal sites (Nisida Roman port, Marechiaro Roman port and Villa Robery) and we studied them by means of both geomorphological observations and geophysical surveys (Side Scan Sonar and Single Beam echo-sounder). Within the submerged Roman port of Nisida, built in the 1st AD, we found two pilae of the ancient pier. The submersion measuring of the well-preserved one provided a palaeo-sea level at 3.1±0.30 m bsl. In the submerged Roman port of Marechiaro, we recognized a still preserved breakwater connected to the tuffaceous sea cliff, and submerged foundations of a 1st century small sea-side villa. Nearby there is also a two-storeyed Roman building (Palazzo degli Spiriti), built in the 1st cent. BC and later restructured to adapt to a phase of subsidence (Gunther 1908). From our submersion measurements, two different paleo-sea levels can be deduced: one for the 1st cent. BC at -4.4 + -0.50 m and another for the 1st cent. AD at -3 + - 0.30 m. Finally, in front of the modern Villa Rosebery the sea bottom shows a sub-horizontal element at -3m to -3.5m bsl, emerged during the 1st BC century. In fact, at least three houses were erected there during said century (Gunther, 1908). As the area was very little elevated, an alignment of pilae was also constructed to protect those houses from the breakers. By

  4. Adaptively Forward Modelling the Spatial Magnetic Effects Due to a Magnetized Structure by Tesseroids in Spherical Coordinate System

    Du, Jinsong; Chen, Chao

    2015-04-01

    GLQI when nodes are ones. The RP method shows a better accuracy when the computing point nears the source located in the low latitude but worse in the high latitude where the RP fails to depict the actual geometric shape of the tesseroid. Because the error decays most quickly as the distance between the source and the computing point increasing, the 3D GLQI with higher than first-order Gaussian nodes is most efficiently combined with the reasonable subdivision technique. Investigation of computational efficiency indicates that, in practical applications, combination of different methods and reasonable choices for the number of subdivision and the Gaussian nodes of the GLQI can produce the most accurate results in an acceptable computational time. The calculated magnetic effects of the global lithospheric magnetization model show that there are little differences between the results at the satellite altitude by the MD method and by the 3D GLQI method but very large differences at the low altitude, which means that the MD method will introduce large errors and become worse and worse as the altitude decreasing. However, the corresponding computation is very time-consuming, especially when the geometric size of the source is large or the DSO is short. Because the error decays most quickly as the DSO increasing, the 3D GLQI with higher than first-order Gaussian nodes is most efficiently combined with the reasonable subdivision technique. Therefore, in order to reduce the computing time while maintaining the desired accuracy, an adaptive forward modeling scheme that consists of using a fixed Gaussian order and recursively subdivision is employed. As a key point in this approach, the relationships between the accuracy of the magnetic effects and the size-to-DSO ratio are focused and investigated. Numerical test shows that this adaptive approach improves the computational efficiency significantly.

  5. Adaptive Multigrid Methods for Fluid-Structure Interaction (FSI) Optimization in an Aircraft and Design of Integrated Structural Health Monitoring (SHM) Systems

    Ebna Hai, Bhuiyan Shameem Mahmood; Bause, Markus

    2013-01-01

    Nowadays, advanced composite materials such as carbon fiber reinforced plastics (CFRP) are being applied to many aircraft structures in order to improve performance and reduce weight. Most composites have strong, stiff fibres in a matrix which is weaker and less stiff. However, aircraft wings can break due to Fluid-Structure Interaction (FSI) oscillations or material fatigue. Material inspection by piezoelectric induced ultrasonic waves is a relatively new and an intelligent technique to moni...

  6. Physico-chemical behavior of ultra high molecular weight polyethylene gamma-irradiated

    Ultra high molecular weight polyethylene (UHMWPE) has been used in several applications, due to its excellent engineering properties. Since 70' that UHMWPE is applied in medical devices specially in orthopedic implants. The use of gamma irradiation has become the preferred method for sterilizing medical products. It is well known that the exposure to gamma rays introduces structural changes that may alter the polymer performance. In the present work, a commercial grade UHMWPE was exposed to gamma radiation at room temperature in the air. The effect of the irradiation on the physico-chemical behavior of a commercial UHMWPE was investigated by gel determination, infrared spectroscopy analysis and thermal analysis (TGA and DSC). The experimental data show changes in the physico-chemical behavior of UHMWPE. The results are presented and discussed. (author)

  7. Effect of Microwave Irradiation on the Physicochemical and Digestive Properties of Lotus Seed Starch.

    Zeng, Shaoxiao; Chen, Bingyan; Zeng, Hongliang; Guo, Zebin; Lu, Xu; Zhang, Yi; Zheng, Baodong

    2016-03-30

    The objective of this study is to investigate the effect of microwave irradiation on the physicochemical and digestive properties of lotus seed starch. The physicochemical properties of lotus seed starch were characterized by light microscopy, (1)H NMR, FT-IR spectroscopy, and HPSEC-MALLS-RI. The starch-water interaction and crystalline region increased due to the changed water distribution of starch granules and the increase of the double-helix structure. The swelling power, amylose leaching, molecular properties, and radius of gyration reduced with the increasing microwave power, which further affected the sensitivity of lotus seed starch to enzymatic degradation. Furthermore, the resistant starch and slowly digestible starch increased with the increasing microwave irradiation, which further resulted in their decreasing hydrolysis index and glycemic index. The digestive properties of lotus seed starch were mainly influenced by the reduced branching degree of amylopectin and the strong amylose-amylose interaction. PMID:26912092

  8. Effect of Potassium Permanganate Nano-Zeolite and Storage Time on Physicochemical Properties of Kiwifruit (Hayward

    H Mirzaee Moghaddam

    2016-04-01

    Full Text Available In this research, kiwifruits (Hayward were selected in two mass ranges (large and small. They were placed in one-liter glass bottles in the vicinity of the polyethylene sachets containing potassium permanganate nano-zeolite (0, 0.2, 0.4 and 0.8 g and were stored in a germinator (5°C temperature and 30% relative humidity. Then, the physicochemical properties of the fruits (soluble solid content, pH, moisture content and fruit firmness and potassium permanganate nano-zeolite color (L, Hue angle, Chroma and E were measured after t 0, 2, 4 and 6 weeks of storage. The factorial treatment structure based on completely randomized block design was used for analyzing the obtained data. The results of analysis showed that potassium permanganate nano-zeolite had a significant effect on the measured physicochemical properties, except for the moisture content (P

  9. The Adaptability of Teams

    Jørgensen, Frances; Boer, Harry

    2006-01-01

    In this paper, data from a longitudinal case study in an organization attempting to adapt its internal work processes to changes in its external context are presented, analyzed and discussed. Specifically, functionally structured work teams in one department of a Danish production facility were...... proper alignment between the structuring of the work processes and characteristics of the external context (Lawrence & Lorsch, 1967) – it provides a unique opportunity to explore the adaptation process in practice. The paper contributes to the development of contingency theory by lending support to the...

  10. Long-chain fatty acids inhibition and adaptation process in anaerobic thermophilic digestion: Batch tests, microbial community structure and mathematical modelling

    Paltsi, Jordi; Illa, J.; Prenafeta-Boldu, F.X.;

    2010-01-01

    . Population profiles of eubacterial and archaeal 16S rDNA genes revealed that no significant shift on microbial community composition took place upon biomass exposure to LCFA. DNA sequencing of predominant DGGE bands showed close phylogenetic affinity to ribotypes characteristic from specific beta......Biomass samples taken during the continuous operation of thermophilic anaerobic digestors fed with manure and exposed to successive inhibitory pulses of long-chain fatty acids (LCFA) were characterized in terms of specific metabolic activities and 16S rDNA DGGE profiling of the microbial community...... structure. Improvement of hydrogenotrophic and acidogenic (beta-oxidation) activity rates was detected upon successive LCFA pulses, while different inhibition effects over specific anaerobic trophic groups were observed. Bioreactor recovery capacity and biomass adaptation to LCFA inhibition were verified...

  11. The spatial habitat structure of host populations explains the pattern of rejection behavior in hosts and parasitic adaptations in cuckoos

    Roskaft, E.; Moksnes, A.; Stokke, B. G.; Moskát, C.; Honza, Marcel

    2002-01-01

    Roč. 13, č. 2 (2002), s. 163-168. ISSN 1045-2249 R&D Projects: GA AV ČR KSK6005114 Institutional research plan: CEZ:AV0Z6093917 Keywords : Cuculus canorus * habitat structure * brood parasitism Subject RIV: EG - Zoology Impact factor: 2.449, year: 2002 http://beheco.oxfordjournals.org/cgi/reprint/13/2/163.pdf

  12. The structure of TAX1BP1 UBZ1+2 provides insight into target specificity and adaptability.

    Ceregido, M Angeles; Spínola Amilibia, Mercedes; Buts, Lieven; Rivera-Torres, José; Garcia-Pino, Abel; Bravo, Jerónimo; van Nuland, Nico A J

    2014-02-01

    TAX1BP1 is a novel ubiquitin-binding adaptor protein involved in the negative regulation of the NF-kappaB transcription factor, which is a key player in inflammatory responses, immunity and tumorigenesis. TAX1BP1 recruits A20 to the ubiquitinated signaling proteins TRAF6 and RIP1, leading to their A20-mediated deubiquitination and the disruption of IL-1-induced and TNF-induced NF-kappaB signaling, respectively. The two zinc fingers localized at its C-terminus function as novel ubiquitin-binding domains (UBZ, ubiquitin-binding zinc finger). Here we present for the first time both the solution and crystal structures of two classical UBZ domains in tandem within the human TAX1BP1. The relative orientation of the two domains is slightly different in the X-ray structure with respect to the NMR structure, indicating some degree of conformational flexibility, which is rationalized by NMR relaxation data. The observed degree of flexibility and stability between the two UBZ domains might have consequences on the recognition mechanism of interacting partners. PMID:24239949

  13. Adaptive Heat Engine

    Allahverdyan, A. E.; Babajanyan, S. G.; Martirosyan, N. H.; Melkikh, A. V.

    2016-07-01

    A major limitation of many heat engines is that their functioning demands on-line control and/or an external fitting between the environmental parameters (e.g., temperatures of thermal baths) and internal parameters of the engine. We study a model for an adaptive heat engine, where—due to feedback from the functional part—the engine's structure adapts to given thermal baths. Hence, no on-line control and no external fitting are needed. The engine can employ unknown resources; it can also adapt to results of its own functioning that make the bath temperatures closer. We determine resources of adaptation and relate them to the prior information available about the environment.

  14. Adaptation to the ECTS of the subject "Construction of Non-structural Elements" for the future degree "Building Engineer"

    Céspedes López, María Francisca; Mora García, Raúl Tomás; Jiménez Delgado, Antonio; Rodríguez Valenzuela, Leoncio

    2009-01-01

    Due to the imminent creation of the degree "Building Engineer", it has been thought appropriate to verify if the criteria set by the EHEA is being applied to the subject of "Construction of Non-structural Elements" in the third year of Technical Architecture. The main objective of the subject is to ensure that students get knowledge and that they can apply it in a technical and objective way. For this reason, a programming of tasks orientated towards the acquisition of competences has been de...

  15. Global displacement of canine parvovirus by a host-adapted variant: structural comparison between pandemic viruses with distinct host ranges.

    Organtini, Lindsey J; Allison, Andrew B; Lukk, Tiit; Parrish, Colin R; Hafenstein, Susan

    2015-02-01

    Canine parvovirus type 2 (CPV-2) emerged in 1978 and spread worldwide within 2 years. Subsequently, CPV-2 was completely replaced by the variant CPV-2a, which is characterized by four specific capsid (VP2) mutations. The X-ray crystal structure of the CPV-2a capsid shows that each mutation confers small local changes. The loss of a hydrogen bond and introduction of a glycine residue likely introduce flexibility to sites that control interactions with the host receptor, antibodies, and sialic acids. PMID:25410876

  16. Nucleosome adaptability conferred by sequence and structural variations in histone H2A-H2B dimers.

    Shaytan, Alexey K; Landsman, David; Panchenko, Anna R

    2015-06-01

    Nucleosome variability is essential for their functions in compacting the chromatin structure and regulation of transcription, replication and cell reprogramming. The DNA molecule in nucleosomes is wrapped around an octamer composed of four types of core histones (H3, H4, H2A, H2B). Nucleosomes represent dynamic entities and may change their conformation, stability and binding properties by employing different sets of histone variants or by becoming post-translationally modified. There are many variants of histones H2A and H2B. Specific H2A and H2B variants may preferentially associate with each other resulting in different combinations of variants and leading to the increased combinatorial complexity of nucleosomes. In addition, the H2A-H2B dimer can be recognized and substituted by chaperones/remodelers as a distinct unit, can assemble independently and is stable during nucleosome unwinding. In this review we discuss how sequence and structural variations in H2A-H2B dimers may provide necessary complexity and confer the nucleosome functional variability. PMID:25731851

  17. A NOVEL APPROACH TO SMOOTHING ON 3D STRUCTURED ADAPTIVE MESH OF THE KINECT-BASED MODELS

    Erdal Özbay

    2013-11-01

    Full Text Available 3-dimensional object modelling of real world objects in steady state by means of multiple point cloud (pcl depth scans taken by using sensing camera and application of smoothing algorithm are suggested in this study. Polygon structure, which is constituted by coordinates of point cloud (x,y,z corresponding to the position of 3D model in space and obtained by nodal points and connection of these points by means of triangulation, is utilized for the demonstration of 3D models. Gaussian smoothing and developed methods are applied to the mesh consisting of merge of these polygons, and a new mesh simplification and augmentation algorithm are suggested for the over the 3D modelling. Mesh consisting of merge of polygons can be demonstrated in a more packed, smooth and fluent way. In this study is shown that applied the triangulation and smoothing method for 3D modelling, perform to a fast and robust mesh structures compared to existing methods therewithal no remeshing is necessary for refinement and reduction.

  18. On the physico-chemical characteristics of brines

    Shirodkar, P.V.; Rao, P.V.S.S.D.P.; Singbal, S.Y.S.

    Analyses of the natural brines form the salt lakes, salt pans and the artificial brines obtained after the solar desalination of seawater respectively, showed wide differences in their physico-chemical characteristics. The natural brines are markEd...

  19. Synthesis, structure and physicochemical properties of lithium uranovanadate

    A new chemical compound, i.e. lithium uranovanadate, was synthesized and studied by the methods of X-ray diffraction, IR spectroscopy and thermography. The standard enthalpies of formation of lithium uranovanadate and its dihydrate at 298.15 K were ascertained using reaction and adiabatic vacuum calorimetry. Temperature dependence of heat capacity in the range of 80 - 300 K of crystal LiVUO6 · 2H2O was studied, thermodynamic characteristics of its synthesis being calculated

  20. Physicochemical and physiological basis of dichromatic colour

    Kreft, Samo; Kreft, Marko

    2007-11-01

    Out of three perceptual characteristics of the colour of any substance, the hue depends mostly on the spectral properties of a substance, while the brightness and saturation depend also on the concentration of a substance and its thickness. Here, we report that evident change of the hue of the colour (i.e., from green to red) is due to a change in concentration or the thickness of a layer in some exceptional substances such as pumpkin seed oil or an aqueous solution of bromophenol blue. In some regions of Central Europe, salad dressing is made preferably with the pumpkin seed oil, which has a strong characteristic nut-like taste and remarkable properties of the colour: it appears red in a bottle, but green when served as a salad dressing. The colour of the pumpkin seed oil was previously described as brownish yellow, dark green, dark green to red ochre or dark reddish brown to light yellow green. We elucidated the physicochemical and physiological basis of such dichromatism by Beer-Lambert law and by the characteristics of human colour perception. Our concept was corroborated by the outcome of calculations of colour from spectral properties using colour matching functions. We found that dichromatism is observed if the absorption spectrum of any substance has at least two local minima: one wide but shallow and one narrow but deep local minimum.

  1. Physicochemical and Antioxidant Properties of Black Garlic

    Il Sook Choi

    2014-10-01

    Full Text Available Black garlic (BG is a processed garlic product prepared by heat treatment of whole garlic bulbs (Allium sativum L. at high temperature under high humidity for several days, resulting in black cloves with a sweet taste. BG has recently been introduced to the Korean market as a product beneficial to health. To clarify how BG changes during the 35 day aging period, the physicochemical characteristics, antioxidant contents, and antioxidant activities were evaluated under controlled conditions of 70 °C and 90% relative humidity. Reducing sugar and total acidity of BG increased during the aging period, whereas pH decreased from pH 6.33 to 3.74. Lightness and yellowness values of BG radically decreased during the aging period, whereas redness values increased significantly. Antioxidant components, including the total polyphenol and total flavonoids contents of BG, increased significantly until the 21st day of aging (p < 0.05 and correspondingly, the antioxidant activities of BG, measured by DPPH, ABTS, FRAP, and reducing power assays, were highest on the 21st day of aging. These results indicate that BG can be considered to not only possess antioxidant properties during the aging period, but also to reach its optimal antioxidant properties at the 21st day of aging.

  2. Pharmaceutical wastewater treatment: a physicochemical study

    A physicochemical study for the treatment of pharmaceutical wastewater was performed. Objective of the laboratory investigation was to study the removal of color, Total Dissolved Solids (TDS), Biochemical Oxygen Demand (BOD), Chemical Oxygen Demand (COD), turbidity and phenol and bring them up to the allowable limits for reuse purposes. Efficiency of coagulation, flocculation, sedimentation, sand filtration followed by activated carbon adsorption was determined. It was found that tested coagulants (alum, ferric chloride, and ferrous sulphate) are not much effective and required high dosage for the removal; of TSS, BOD, COD and turbidity. Alum was found to be more effective among tested coagulants and reduce TSS, BOD, COD and turbidity 79.6%, 34.8, 48.6% and 69.2% respectively. Sand filtration further reduced the studied parameters 97.7%, 95.7%, 93.9% and 76.9% respectively. As the concentration of phenol in the studied pharmaceutical wastewater was 100 mg/l, granular activated carbon was used to remove phenol up to the allowable limit for reuse purpose. Activated carbon adsorption further reduces phenol, TDS, TSS, BOD, and COD up to 99.9%, 99.1%, 21.4%, 81.3% and 71.1% respectively. High removal of color observed after activated carbon adsorption. It was concluded that the suggested treatment scheme is suitable to bring the effluent quality up to the water quality standards. (author)

  3. Physicochemical characterization of two deproteinized bovine xenografts

    Thais Accorsi-Mendonça

    2008-03-01

    Full Text Available Calcium phosphate salts, or more specifically hydroxyapatite, are products of great interest in the fields of medical and dental science due to their biocompatibility and osteoconduction property. Deproteinized xenografts are primarily constituted of natural apatites, sintered or not. Variations in the industrial process may affect physicochemical properties and, therefore, the biological outcome. The purpose of this work was to characterize the physical and chemical properties of deproteinized xenogenic biomaterials, Bio-Oss (Geistlich Biomaterials, Wolhuser, Switzerland and Gen-Ox (Baumer S.A., Brazil, widely used as bone grafts. Scanning electron microscopy, infrared region spectroscopy, X-ray diffraction, thermogravimetry and degradation analysis were conducted. The results show that both materials presented porous granules, composed of crystalline hydroxyapatite without apparent presence of other phases. Bio-Oss presented greater dissolution in Tris-HCl than Gen-Ox in the degradation test, possibly due to the low crystallinity and the presence of organic residues. In conclusion, both commercial materials are hydroxyapatite compounds, Bio-Oss being less crystalline than Gen-Ox and, therefore, more prone to degradation.

  4. Physicochemical properties of cookies enriched with xylooligosaccharides.

    Ayyappan, P; Abirami, A; Anbuvahini, N A; Tamil Kumaran, P S; Naresh, M; Malathi, D; Antony, Usha

    2016-07-01

    The growing commercial importance of xylooligosaccharides is based on their beneficial health properties, particularly their ability to stimulate the growth and activity of intestinal bacteria such as Bifidobacterium and Lactobacillus species. Xylooligosaccharides are less sweet, acid, and heat stable, with low recommended levels of intake compared to other oligosaccharides. In view of the consumer demand for foods with low sugar, low fat, and high fiber contents, they are suitable for incorporation into bakery products. In this study, we have developed wheat-based cookies incorporated with xylooligosaccharides at 5%, 10%, and 15% levels. The nutritive value and physicochemical properties of the cookies changed with xylooligosaccharides incorporation; both crude fiber and dietary fiber contents increased by 14% and 35%, respectively, in the enriched cookies. The moisture levels increased with increase in the percentage of xylooligosaccharides incorporated. Cookies with 5% xylooligosaccharides were found most acceptable, although the color was slightly darker compared to the control, while cookies with 10% and 15% xylooligosaccharides were softer and darker and therefore less acceptable. Enrichment with xylooligosaccharides at 5% provided a product stable for 21 days at room temperature (25 ± 2℃). The storage stability of cookies with higher levels of xylooligosaccharides was less than the 5% xylooligosaccharides cookies and control. The retention of the prebiotic xylooligosaccharides in the products was relatively high (74%). PMID:26644158

  5. PHYSICOCHEMICAL AND RHEOLOGICAL CHARACTERIZATION OF AVOCADO OILS

    Tamara de Souza Jorge

    2015-08-01

    Full Text Available Avocado oil is rich in bioactive compounds, which can improve human health by acting as an antioxidant. It may be extracted from different varieties of avocado, such as Margarida and Hass varieties, each of them with particular characteristics. Aiming to evaluate the differences between them, avocado fruits and pulps from these were analyzed according to their physicochemical characteristics. After extracted, the oils had their bioactive characteristics studied and rheological behavior determined through a rotational rheometer. They were then compared to commercial avocado oil. The fruits of Margarida variety had greater size, higher weight (664.51 g, and higher pulp yield (72.19% than Hass variety, which showed higher lipid content (65.29 g/100 g dry basis. The commercial oil showed less primary oxidative degradation, whereas Margarida variety had a lower level of secondary degradation products as well as a higher content of bioactive compounds, such as phytosterols (999.60 mg/kg and tocopherols (36.73 mg/kg. The rheological behaviors of both oils were appropriately described through Newton model, with R2 > 0.999 for all temperatures. By an Arrhenius type equation, it was verified that Hass's rheological parameters are more influenced by temperature than Margarida and commercial oil, presenting activation energy of 33.6 kJ/mol.

  6. Microbiological and physicochemical quality of drinking water

    This study was conducted on the water samples collected before and after filtration treatment was given. Five types of filtered drinking water (A1, B1, C1, D1 and E2) were chosen randomly from houses in Klang Valley for analyses. The purpose of this study was to determine the quality of filtered drinking water by looking into microbiological aspect and several physicochemical analyses such as turbidity, pH and total suspended solid (TSS). The microbiological analyses were performed to trace the presence of indicator organisms and pathogens such as Escherichia coli, Streptococcus faecalis and Pseudomonas aeruginosa. All of the water did not comply with the regulations of Food Act as consisted of more than 103-104 cfu/ mL for total plate count. However, the total coliforms and E. coli were detected lower than 4 cfu/ mL and not exceeding the maximum limit of Food Act. While the presence of S. faecalis and P. aeruginosa were negative in all samples. The pH value was slightly acidic (pH -4 - 2.2 x 10-3 mg/ L) and the turbidity for all the samples were recorded below 1 Nephelometric Turbidity units (NTU) thus, complying with the regulations. All the water samples that undergo the filtration system were fit to be consumed. (author)

  7. Is adaptation. Truly an adaptation? Is adaptation. Truly an adaptation?

    Thais Flores Nogueira Diniz

    2008-04-01

    Full Text Available The article begins by historicizing film adaptation from the arrival of cinema, pointing out the many theoretical approaches under which the process has been seen: from the concept of “the same story told in a different medium” to a comprehensible definition such as “the process through which works can be transformed, forming an intersection of textual surfaces, quotations, conflations and inversions of other texts”. To illustrate this new concept, the article discusses Spike Jonze’s film Adaptation. according to James Naremore’s proposal which considers the study of adaptation as part of a general theory of repetition, joined with the study of recycling, remaking, and every form of retelling. The film deals with the attempt by the scriptwriter Charles Kaufman, cast by Nicholas Cage, to adapt/translate a non-fictional book to the cinema, but ends up with a kind of film which is by no means what it intended to be: a film of action in the model of Hollywood productions. During the process of creation, Charles and his twin brother, Donald, undergo a series of adventures involving some real persons from the world of film, the author and the protagonist of the book, all of them turning into fictional characters in the film. In the film, adaptation then signifies something different from itstraditional meaning. The article begins by historicizing film adaptation from the arrival of cinema, pointing out the many theoretical approaches under which the process has been seen: from the concept of “the same story told in a different medium” to a comprehensible definition such as “the process through which works can be transformed, forming an intersection of textual surfaces, quotations, conflations and inversions of other texts”. To illustrate this new concept, the article discusses Spike Jonze’s film Adaptation. according to James Naremore’s proposal which considers the study of adaptation as part of a general theory of repetition

  8. Relation between Grape Wine Quality and Related Physicochemical Indexes

    Zi-Yue Chen; Yuan-Biao Zhang; Qiu-Ye Qian

    2013-01-01

    The aim of this study is to evaluate grape wine quality more objectively by reducing the error of traditional grape-wine-quality evaluation. On combining grape wine quality and physicochemical index of grapevine, we provided a grape-wine-quality evaluation model by grapevine’s physicochemical index in this study. Firstly, evaluations of the tasters are analyzed, for eliminating the disturbance caused by their individual difference. Then, relationship between grape wine and grapevines are anal...

  9. Physicochemical characterization of natural honeys from different regions in Slovakia

    Sudzina, M.; Melich, Martin; Kňazovická, Vladimíra; Felšöciová, Soňa; Kociubinski, Guillermo; Andreji, Jaroslav; Pavličová, Simona; Kráčmar, Stanislav

    2009-01-01

    This study is intended to determine the physicochemical characteristics of Slovakian honeys, and compare them with specifications described in the Codex Alimentarius Standard, the European Honey directive, the Slovak Codex Alimentarius and Slovak standard No. 1/2006. In addition, we tried to find out correlations between individual constituents of honeys. Physicochemical characterization was carried out following the harmonized methods dictated by the International Honey Commission IHC. Honey...

  10. The Physicochemical Changes of Black Garlic during Thermal Processing

    Mengmeng Lei; Zesheng Zhang; Rui Liu; Min Zhang; Mengying Xu

    2015-01-01

    To explore the physicochemical changes of black garlic during the thermal processing steps and further reveal the role of Maillard reaction in the formation mechanism of black garlic. The physicochemical changes including UV-Vis absorbance, fluorescence and color difference were determined. The UV absorbance at 294 nm and browning intensity at 420 nm gradually increased with increasing heating time, while the fluorescence intensity showed a maximum value at the heating time of 3 days. The col...

  11. EVALUATION OF PHYSICOCHEMICAL & PHYTOCHEMICAL PARAMETERS OF AMARANTHUS CAUDATUS LEAVES

    Hiremath G. Urmila

    2012-01-01

    The present study was carried out to provide physicochemical and phytochemical detail about the plant Amaranthus caudatus. The physicochemical results obtained can be used for the identification of the powdered drugs. In the phytochemical screening different type of extracts were prepared to find the presence of secondary metabolites. The results revealed the presence of carbohydrates, glycosides, saponins, proteins, amino acids, tannins, and phenolic compounds in the plant. Amaranthus caud...

  12. Evaluation of Physicochemical and Microbiological Parameters of Smoked Sausages

    Melinda Nagy; Sonia A. Socaci; Maria Tofană; Crina Mureșan; Ana Viorica Pop (Cuceu); Carmen Pop

    2015-01-01

    Meat and meat products continue to supply nutrients and play a vital role in human life because of their high biological value protein, iron, zinc, selenium and vitamin B12 contents, being a crucial component of a well balanced diet. The objective of this paper was to analyse the microbiological and physicochemical characteristics of smoked sausage obtain by a modern recipe. The meat  material was obtained from local butchery (Cluj-Napoca, Romania). The physicochemical analyses highlighted th...

  13. Electrical conduction in solid materials physicochemical bases and possible applications

    Suchet, J P

    2013-01-01

    Electrical Conduction in Solid Materials (Physicochemical Bases and Possible Applications) investigates the physicochemical bases and possible applications of electrical conduction in solid materials, with emphasis on conductors, semiconductors, and insulators. Topics range from the interatomic bonds of conductors to the effective atomic charge in conventional semiconductors and magnetic transitions in switching semiconductors. Comprised of 10 chapters, this volume begins with a description of electrical conduction in conductors and semiconductors, metals and alloys, as well as interatomic bon

  14. Physicochemical characterization of chitosan nanoparticles: electrokinetic and stability behavior.

    López-León, T; Carvalho, E L S; Seijo, B; Ortega-Vinuesa, J L; Bastos-González, D

    2005-03-15

    Some physical properties of nanogel particles formed by chitosan ionically cross-linked by tripolyphosphate (TPP) have been studied. Electrokinetic properties and colloidal stability were analyzed as a function of pH and ionic strength of the medium. Chitosan particles showed volume phase transitions (swelling/shrinking processes) when the physicochemical conditions of the medium were changed. Experimental data were mainly obtained by electrophoretic mobility measurements and by photon correlation spectroscopy and static light scattering techniques. Chitosan chains possess glucosamine groups that can be deprotonated if the pH increases. Therefore, modification of pH from acid to basic values caused a deswelling process based on a reduction of the intramolecular electric repulsions inside the particle mesh. Electrophoretic mobility data helped to corroborate the above electrical mechanism as responsible for the size changes. Additionally, at those pH values around the isoelectric point of the chitosan-TPP particles, the system became colloidally unstable. Ionic strength variations also induced important structural changes. In this case, the presence of KCl at low and moderate concentrations provoked swelling, which rapidly turned on particle disintegration due to the weakness of chitosan-TPP ionic interactions. These last results were in good agreement with the predictions of gel swelling theory by salt in partially ionized networks. PMID:15721903

  15. The physicochemical characterisation of pepsin degraded pig gastric mucin.

    Abodinar, Atiga; Tømmeraas, Kristoffer; Ronander, Elena; Smith, Alan M; Morris, Gordon A

    2016-06-01

    Mucins are the main macromolecular components of the mucus secretions that cover the oral cavity, gastrointestinal and urogenital tracts of animals. The properties of the mucus secretions are therefore directly correlated with the physicochemical properties of mucin glycoproteins. In this study, mucins were obtained from pig gastric mucous after digestion with pepsin at 37°C for 4h, these mucins were characterised in terms of compositional and hydrodynamic properties. Compositional analysis showed that this mucin contains protein (15%), carbohydrates (55%) of which the constituents are: fucose (4%), galactose (9%), glucosamine (55%), glucosamine (33%) and sialic acid (2%). The latter component gives the mucin polymer a pH-dependant negative charge, with a ζ-potential of -3mV at pH 1.2 up to -11mV at pH 7.4. The weight average molar mass was ∼1×10(6)g/mol and intrinsic viscosity was ∼0.42dL/g although there was a small pH dependency due to the polyelectrolyte behavior of the polymer. The measurements of viscosity versus shear rate showed shear thinning behavior and the critical overlap concentration was determined to be 10-11% w/v indicating a compact structure. Knowledge of these properties is fundamental to the understanding interactions of mucins, with for example, novel drug delivery systems. PMID:26944659

  16. Characterization and Physicochemical Properties of Condensed Tannins from Acacia catechu.

    Duval, Antoine; Avérous, Luc

    2016-03-01

    Condensed tannins from Acacia catechu were carefully studied to determine their chemical structure and physicochemical properties. The combined use of MALDI-TOF-MS and (13)C NMR revealed that catechin and epicatechin are the predominant monomers. Most of the compounds were dimers, as confirmed by size exclusion chromatography measurements. To evaluate their potential as aromatic building block in polymer synthesis, special care was given to the characterization and quantification of the different OH groups. A detailed (31)P NMR analysis showed the predominance of catechin, with a catechin/epicatechin ratio of 4.2:1. Two distinct (1)H NMR measurements confirmed the quantification. The thermal properties were also determined: the tannins showed a high temperature of degradation (ca. 190 °C) and a high glass transition temperature (ca. 140 °C), allowing for thermal processing or chemical reactions at relatively high temperature. A. catechu tannins thus present interesting features to be used as aromatic building blocks in polymer materials. PMID:26853705

  17. Physicochemical and functional properties of yeast fermented brown rice flour.

    Ilowefah, Muna; Bakar, Jamilah; Ghazali, Hasanah M; Mediani, Ahmed; Muhammad, Kharidah

    2015-09-01

    In the current study, effects of fermentation on physicochemical and functional properties of brown rice flour (BRF) were investigated. Fermentation conditions were optimized using response surface methodology to achieve moderate acidity (pH 5-6), specifically pH 5.5 of brown rice batter with time, temperature and yeast concentration as the independent variables. The results indicated that brown rice batter was well fermented to maintain pH 5.5 at optimum conditions of 32 °C for 6.26 h using 1 % yeast concentration. Fermentation at moderate acidity significantly increased the levels of protein, total ash, insoluble fiber, soluble fibre, minerals, phenolics, antioxidants, resistant starch, riboflavin, pyridoxine, nicotinic acid, γ-tocotrienol, and δ-tocotrienol. However, it reduced the contents of γ-oryzanol, γ-tocopherol, α-tocopherol, phytic acid, amylose and total starch. Foaming capacity, foaming stability, oil holding capacity, gelatinization temperatures, enthalpy and whiteness of BRF were increased after fermentation. In contrast, its swelling power, water solubility index, hot paste viscosity, breakdown, and setback significantly decreased. Microstructure of BRF was also influenced, where its starch granules released from its enclosed structure after fermentation. This investigation shows evidence that yeast fermentation modified the functionality of BRF and can be used as a functional food ingredient. PMID:26344967

  18. Structure and function of cytochrome P450S in insect adaptation to natural and synthetic toxins: insights gained from molecular modeling.

    Schuler, Mary A; Berenbaum, May R

    2013-09-01

    Over evolutionary time, insect herbivores have adapted to the presence of natural toxins and more recently to synthetic insecticides in or on the plants they consume. Biochemical analyses and molecular modeling of the cytochrome P450 monooxygenases (P450s) that metabolize these compounds have provided insight into the many variations affecting their catalytic activity. Phylogenetically distinct P450s may metabolize similar substrates, and phylogenetically similar P450s may metabolize different substrates; as well, some P450s process broad arrays of both phytochemicals and synthetic insecticides, while closely related P450s are restricted to a narrow range of phytochemicals. Mapped on the predicted three-dimensional structures of insect P450s developed from available mammalian P450 crystal structures, differences in multiple regions of the insect proteins reveal the evolutionary processes occurring as P450 genes have duplicated and diverged. Analyses of site-directed mutants in select lepidopteran and dipteran P450s demonstrate that slight changes in the catalytic site, the putative product release channel, and the proximal surface (interacting with electron transfer partners such as cytochrome P450 reductase and cytochrome b5) yield pronounced activity differences. Additionally, changes in the catalytic site and in the linker region preceding the proline-hinge influence P450 folding. With predicted structures available for many mammalian P450s involved in metabolism of xenobiotics, it is possible to record allelic variation relative to catalytically important regions in the overall P450 structure and to predict functionally critical differences. Together with information on the relative levels of allelic variant transcripts, comprehensive characterization of the mechanisms that modulate metabolism of natural and synthetic xenobiotics in insects can yield insights into plant-insect coevolution and into novel approaches for chemical pest management. PMID:24036972

  19. In silico Analysis of HIV-1 Env-gp120 Reveals Structural Bases for Viral Adaptation in Growth-Restrictive Cells

    Yokoyama, Masaru; Nomaguchi, Masako; Doi, Naoya; Kanda, Tadahito; Adachi, Akio; Sato, Hironori

    2016-01-01

    Variable V1/V2 and V3 loops on human immunodeficiency virus type 1 (HIV-1) envelope-gp120 core play key roles in modulating viral competence to recognize two infection receptors, CD4 and chemokine-receptors. However, molecular bases for the modulation largely remain unclear. To address these issues, we constructed structural models for a full-length gp120 in CD4-free and -bound states. The models showed topologies of gp120 surface loop that agree with those in reported structural data. Molecular dynamics simulation showed that in the unliganded state, V1/V2 loop settled into a thermodynamically stable arrangement near V3 loop for conformational masking of V3 tip, a potent neutralization epitope. In the CD4-bound state, however, V1/V2 loop was rearranged near the bound CD4 to support CD4 binding. In parallel, cell-based adaptation in the absence of anti-viral antibody pressures led to the identification of amino acid substitutions that individually enhance viral entry and growth efficiencies in association with reduced sensitivity to CCR5 antagonist TAK-779. Notably, all these substitutions were positioned on the receptors binding surfaces in V1/V2 or V3 loop. In silico structural studies predicted some physical changes of gp120 by substitutions with alterations in viral replication phenotypes. These data suggest that V1/V2 loop is critical for creating a gp120 structure that masks co-receptor binding site compatible with maintenance of viral infectivity, and for tuning a functional balance of gp120 between immune escape ability and infectivity to optimize HIV-1 replication fitness. PMID:26903989

  20. Adapting to Environmental Jolts.

    Meyer, Alan D.

    1982-01-01

    Examines the reactions of three San Francisco (California) hospitals to the 1975 doctors' strike. Analyzes the anticipatory, responsive, and readjustment phases of the hospitals' adaptations in terms of each hospital's previous market strategy, organizational structure and ideology, and deployment of slack resources, including financial, human,…