Attachment Mode Research Articles

Expansion of Antimonato Polyoxovanadates with Transition Metal Complexes: (Co(N3C5H15)2)2[{Co(N3C5H15)2}V15Sb6O42(H2O)]·5H2O and (Ni(N3C5H15)2)2[{Ni(N3C5H15)2}V15Sb6O42(H2O)]·8H2O

Two new polyoxovanadates (Co(N(3)C(5)H(15))(2))(2)[{Co(N(3)C(5)H(15))(2)}V(15)Sb(6)O(42)(H(2)O)]·5H(2)O (1) and (Ni(N(3)C(5)H(15))(2))(2)[{Ni(N(3)C(5)H(15))(2)}V(15)Sb(6)O(42)(H(2)O)]·8H(2)O (2) (N(3)C(5)H(15) = N-(2-aminoethyl)-1,3-propanediamine) were synthesized under solvothermal conditions and structurally characterized. In both structures the [V(15)Sb(6)O(42)(H(2)O)](6-) shell displays the main structural motif, which is strongly related to the {V(18)O(42)} archetype cluster. Both compounds crystallize in the triclinic space group P1 with a = 14.3438(4), b = 16.6471(6), c = 18.9186(6) Å, α = 87.291(3)°, β = 83.340(3)°, γ = 78.890(3)°, and V = 4401.4(2) Å(3) (1) and a = 14.5697(13), b = 15.8523(16), c = 20.2411(18) Å, α = 86.702(11)°, β = 84.957(11)°, γ = 76.941(11)°, and V = 4533.0(7) Å(3) (2). In the structure of 1 the [V(15)Sb(6)O(42)(H(2)O)](6-) cluster anion is bound to a [Co(N(3)C(5)H(15))(2)](2+) complex via a terminal oxygen atom. In the Co(2+)-centered complex, one of the amine ligands coordinates in tridentate mode and the second one in bidentate mode to form a strongly distorted CoN(5)O octahedron. Similarly, in compound 2 an analogous NiN(5)O complex is joined to the [V(15)Sb(6)O(42)(H(2)O)](6-) anion via the same attachment mode. A remarkable difference between the two compounds is the orientation of the noncoordinated propylamine group leading to intermolecular Sb···O contacts in 1 and to Sb···N interactions in 2. In the solid-state lattices of 1 and 2, two additional [M(N(3)C(5)H(15))(2)](2+) complexes act as countercations and are located between the [{M(N(3)C(5)H(15))(2)}V(15)Sb(6)O(42)(H(2)O)](4-) anions. Between the anions and cations strong N-H···O hydrogen bonds are observed. In both compounds the clusters are stacked along the b axis in an ABAB fashion with cations and water molecules occupying the space between the clusters. Magnetic characterization demonstrates that the Ni(2+) and Co(2+) cations do not significantly couple with the S = 1/2 vanadyl groups. The susceptibility data can be successfully reproduced assuming a distorted ligand field for the Co(2+) ions (1) and an O(h)-symmetric Ni(2+) ligand field (2).

Pet in the therapy room: An attachment perspective on Animal-Assisted Therapy

John Bowlby's (1973, 1980, 1982) attachment theory is one of the most influential theories in personality and developmental psychology and provides insights into adjustment and psychopathology across the lifespan. The theory is also helpful in defining the target of change in psychotherapy, understanding the processes by which change occurs, and conceptualizing cases and planning treatment (Daniel, 2006; Obegi & Berant, 2008; Sable, 2004; Wallin, 2007). Here, we propose a model of Animal-Assisted Therapy (AAT) based on attachment theory and on the unique characteristics of human–pet relationships. The model includes clients' unmet attachment needs, individual differences in attachment insecurity, coping, and responsiveness to therapy. It also suggests ways to foster the development of more adaptive patterns of attachment and healthier modes of relating to others.

Arc Attachments on Aluminium During Tungsten Electrode Positive Polarity in TIG Welding of Aluminium

In modem AC power sources, both balance and current of EP (tungsten electrode positive) and EN (tungsten electrode negative) can be readily adjusted. According to conventional assumptions the surface of aluminium workpieces is cleaned during EP but the tungsten electrode is more heated due to electron work function. During EN the tungsten electrode cools down and the workpiece is melted. Therefore, optimal settings of the power source mostly aim for maximal penetration and minimal electrode wear. This paper presents a study of arc attachments in TIG welding on aluminium. Two different arc attachments to the cathodic workpiece could be attested with only one of them actually cleaning the surface. The first one is a spot mode (highly dynamic) that attaches to the edges of oxide layers and cracks them. The second one is also a spot mode, but it attaches to weld pools. It does not clean the surface but heats the base material intensively. Both arc attachment modes compete against each other. As a result, the cleaning area narrows with wider weld pools due to an increasing attachment to the weld pool during EP. The influences on the arc attachment to the aluminium cathode as well as the contradictions in present literature are discussed. Possible adjustments of the AC balance for optimized processes are proposed.

Component mode synthesis approaches for quantum mechanical electrostatic analysis of nanoscale devices

In this paper, two component mode synthesis (CMS) approaches, namely, the fixed interface CMS approach and the free interface CMS approach, are presented and compared for an efficient solution of 2-D Schrodinger-Poisson equations for quantum-mechanical electrostatic analyses of nanostructures and devices with arbitrary geometries. In the CMS approaches, a nanostructure is divided into a set of substructures or components and the eigenvalues (energy levels) and eigenvectors (wave functions) are computed first for all the substructures. The computed wave functions are then combined with constraint or attachment modes to construct a transformation matrix. By using the transformation matrix, a reduced-order system of the Schrodinger equation is obtained for the entire nanostructure. The global energy levels and wave functions can be obtained with the reduced-order system. Through an iteration procedure between the Schrodinger and Poisson equations, a self-consistent solution for charge concentration and potential profile can be obtained. Numerical calculations show that both CMS approaches can largely reduce the computational cost. The free interface CMS approach can provide significantly more accurate results than the fixed interface CMS approach with the same number of retained wave functions in each component. However, the fixed interface CMS approach is more efficient than the free interface CMS approach when large degrees of freedom are included in the simulation.

Environmental determinants and ecologic selectivity of benthic faunas from nearshore to bathyal zones in the end-Permian mass extinction: Brachiopod evidence from South China

In South China the Changhsingian brachiopods are extraordinarily abundant and diverse, comprising 447 species in 143 genera. They were widespread in nearshore, shallow sea, reef, carbonate platform, shelf basin, and bathyal zones. Brachiopod attachment modes were also highly diversified and include burrowing, body cementation, pedicle attaching on substratum, body spines anchoring on substratum, pedicle attaching on objects, and clasping spines anchoring on other objects. They suffered the species and genus extinction rates of 91.5% and 86%, respectively in the first episode of the end-Permian mass extinction and further species and genus extinction rates of 84.2% and 80.0%, respectively in the second crisis. For the Permian−Triassic (P–Tr) brachiopods, there were (1) selective extinction of the normal shallow marine dwellers relative to these inhabiting deep sea or marginal seas, and (2) among the normal shallow marine habitats, selective extinction of reef-dwellers relative to non-reef forms. Ecologically, the body-cementation forms suffered much higher extinction rates than other lifestyle elements. In contrast, both the burrowing and clasping spine-anchoring forms had much lower extinction rates than other lifestyle elements. Although the reef and bathyal dwellers partly survived the first extinction event, they migrated to other habitats to survive the crisis. The estimation of extinction rates based on the single-episode mass extinction pattern cannot reveal precisely the extinction severity of brachiopod faunas over the P–Tr transition. Brachiopod diversity changes support the two-stage mass extinction pattern near the P−Tr boundary.

Component Mode Modification Technique for Vibration Control

In the present paper, a vibration mode modification method when the dynamic characteristics of the vibration system change by assembly is proposed. When the dynamic characteristics change, component mode synthesis (CMS) is widely used. However, CMS is not suitable for vibration control. Therefore, the present paper proposes a component mode modification technique for vibration control problem. The vibration modes are modified using component modes for constructing a reduced-order model. In this method, vibration modes are modified using static correction modes (attachment modes). Using these modes, orthogonalization is performed by subspace iteration. First, the concept of vibration mode modification is proposed. This concept is then applied to the proposed modeling method, which is referred to as the extended reduced-order physical modeling method. Finally, the proposed method is examined through dynamic responses of an elastic vehicle. Using the elastic vehicle, a single lane change test and simulation are carried out.

Chain Stiffness and Attachment-Dependent Attraction between Polyelectrolyte-Grafted Colloids

We report here the effects of chain stiffness and surface attachment on the effective interactions between polyelectrolyte-grafted colloidal particles in monovalent salt obtained using Monte Carlo simulations. Our approach involves computation of the distance-dependent potential of mean force between two polyelectrolyte-grafted colloidal particles treated at a coarse-grained resolution. Two chain stiffnesses, flexible and stiff, and two surface attachment modes, free and constrained, at low grafting densities are examined. PMF calculations across a range of surface and polyelectrolyte charge allows us to map out the strength and extent of the attractive and repulsive regime in the two-dimensional charge space. We observe striking differences in the effects of chain stiffness between the two modes of attachment. When the chains are freely attached, the stiff-chains colloids exhibit a marginal reduction in the attraction compared to their flexible-chain counterparts. In contrast, when the chains are attached in a constrained manner, the colloids with stiff chains exhibit a significantly stronger attraction and a broader attractive regime compared to flexible-chain colloids. These differences in the effects of stiffness between the two attachment modes are explained in terms of differences in the energetic and entropic forces balancing adsorption of chains at their own surface versus chain extension to mediate bridging interactions across two particles. Our results thus underscore the importance of surface attachment of chains and its proper accounting in computational and experimental studies and suggests the mode of chain attachment as an additional control parameter for modulating intercolloid interactions for applications such as stabilization of colloidal systems and bottom-up self-assembly of nanostructures.

Larval release and attachment modes of the hydroid Ectopleura larynx on aquaculture nets in Norway

[Extract] In the finfish industry, clean cage nets are essential for the health of the stock (Braithwaite & McEvoy 2005). The accumulation of biofouling, the unwanted attachment of marine organisms on submerged surfaces, decreases the water flow through nets. Subsequently, the water quality within sea cages is reduced, which may affect fish health negatively (Cronin, Cheshire, Clarke & Melville 1999; de Nys & Guenther 2009). Over the last decade, the hydroid Ectopleura larynx (syn. Tubularia larynx) has become one of the most common fouling organisms in the Norwegian fish farming industry, causing increasing problems for farmers (Guenther, Carl & Sunde 2009). The rapid growth of E. larynx on aquaculture nets requires fish farmers to clean their nets regularly, often on a fortnightly basis during the peak of the biofouling season between July and November (Guenther et al. 2009). To reduce biofouling, the majority of Norwegian salmon farmers use copper-based coatings on nets, combined with regular underwater high-pressure washing (200–300 bar) with rotating discs (Olafsen 2006). Anecdotal observations suggest that hydroids grow back faster once the first washing has taken place (B. Jensen, salmon farm manager, pers. comm.).

Performances of some reduced bases for the stability analysis of a disc/pads system in sliding contact

The complex eigenvalue analysis is a widely used technique to investigate the stability of a dynamical system with frictional contact. In the case of brake systems, it is the most frequently employed method to study the propensity of the brake to generate squeal noise. When finite element models are considered, iterative solvers are needed to calculate the complex modes and eigenvalues with good precision. In practice, reduced real bases are often used in order to reduce the computational times. However, great attention should be focused on the errors introduced by the reduction, which is rarely done. In this paper, the performances of some reduced bases are investigated in the case of a simple disc/pads system. Bases composed of real coupled modes and bases provided by Component Mode Synthesis (CMS) techniques are tested. An enrichment of these bases is proposed in order to improve the precision of the results. In particular, new rubbing attachment modes are proposed to adapt free-interface CMS techniques to frictional contact. When real coupled modes are used, it is suggested to complete the basis by the static response to a first-order approximation of the friction forces. Applied to the disc/pads model, the different enrichment options allow a reduction of the errors on frequencies, divergence rates and mode shapes by a factor comprised between 10 and 100 without significantly increasing the computational times.

Fluorescent Labeling of (Oligo)Nucleotides by a New Fluoride Cleavable Linker Capable of Versatile Attachment Modes

The development of a fluoride cleavable linker 1 for reversibly labeling (oligo)nucleotides is described here. The linker allows different ways of chemical attachment of a reporter molecule, for example, click chemistry or amide formation. The versatile attachment modes of labels are demonstrated by derivatizations with pyrene and fluorescein. Besides the synthesis of the new linker, we also show the derivatization of iodobenzene as a model compound and a nucleoside to demonstrate the applicability. Further, cleavability studies in solution and on a solid-supported oligonucleotide are shown. The linker can be applied in the synthesis of reversible terminators, useful for new DNA sequencing technologies like cyclic reversibly terminating (CRT) sequencing.

Peptide−TiO2 Interaction in Aqueous Solution: Conformational Dynamics of RGD Using Different Water Models

Adsorption behavior and dynamics of Arg-Gly-Asp (RGD) tripeptides with different orientations onto the rutile TiO(2) (110) surface in water solution were systematically investigated by molecular dynamics (MD) simulations, using two different water models, TIP3P (transferable intermolecular potential 3P) and SPC/E (extended simple point charge). Possible RGD-TiO(2) binding modes in the form of hydrogen-bonding interactions, involving the amide groups (NH(3)(+) or NH(2)(+), NH(2)) and surface oxygen atoms were identified. The behavior of RGD in contact with the TiO(2) layer was elucidated in detail by the analysis of atom-atom distances, backbone dihedral angles and hydration layers distributed over the interface. The simulation results suggest that, the attachment modes of tripeptides with the same starting arrangement are similar when solvated in TIP3P and SPC/E water, but the conformational stability of the amino sequence is somewhat sensitive to the adopted solvent model. Moreover, the intensity of peptide-surface interaction varies widely depending on the initial arrangement of the RGD sequence.

Native chemical ligation in the synthesis of internally modified oligonucleotide–peptide conjugates

Peptide-oligonucleotide conjugates have frequently been synthesized to improve cellular delivery of antisense or antigene compounds, to allow the immobilization of peptide and protein conjugates on DNA arrays, or to decorate nucleic acid architectures with peptide functions. In such applications, the site of conjugation is of little importance, and peptides have predominantly been appended to one of the terminal ends of the oligonucleotide by using an oxime-, thioether-, or disulfide-linkage or native chemical ligation. We, herein, demonstrate the first coupling of peptides to sequence internal sites. This attachment mode provides better control of the spatial arrangement of peptides presented by self-assembled nucleic acid scaffolds. Internal modification requires special phosphoramidite building blocks that can be used in automated DNA synthesis. For this purpose, Fmoc/StBu-protected cysteine was attached via an aminopropargyl linker to the C5-position of uridine. The rigid triple bond conferred a high reactivity in native chemical ligation reactions of 5-6mer peptide thioesters with up to 15 nucleotides long oligonucleotides. The desired peptide-oligonucleotide conjugates were obtained in high yields after purification. UV melt experiments revealed that the peptide modification does not hamper nucleic acid hybridization. This finding marked an important step in our research program devoted to studies of multivalent presentation of peptides via modular assembly of nucleic acid complexes.

Attachment mode performance of network-modeled ballistic fabric shielding

A central issue in the use of ballistic fabric shielding is the mode of attachment to the structure that it is intended to protect. In order to investigate this issue, a discrete multi-scale yarn-network model is developed for structural fabric undergoing ballistic impact, based on work found in Zohdi and Powell [Zohdi TI, Powell D. Multiscale construction and large-scale simulation of structural fabric undergoing ballistic impact. Comput Meth Appl Mech Eng 2006;195:94–109] and Zohdi [Zohdi TI. Modeling/simulation of progressive penetration of multilayered ballistic fabric shielding. Comput Mech 2002;29:61–7]. The model is comprised of a network of yarn with stochastic properties determined by smaller-scale fibrils, which are randomly misaligned. The effects of stochasticity on the overall response are explored, and the model is compared against macro-scale experiments. The key feature of the model is the fact that it does not depend on phenomenological parameters, and can be calibrated by simply measuring the properties of an individual, smallest-scale, fibril. The properties of a fibril are easily ascertained from a simple tension test. The response of the overall fabric model and ballistic experiments are in excellent agreement. The model indicates that fabric which is attached by being pinned at the corners generally absorbs more energy, relative to fabric clamped along the sides. The basis for this result is discussed at length in the body of this work. Furthermore, it is observed that a uniform-yarn model, one which ignores the stochastic nature of the yarn, over-estimates the amount of energy absorbed.

Influence of a transverse magnetic field on arc root movements in a dc plasma torch: Diamagnetic effect of arc column

The effect of a transverse magnetic field on the anodic arc root movement inside a dc plasma torch has been investigated. The arc voltage fluctuation, which represents the degree of the arc instability, was reduced to 28.6% of the original value and the high frequency components in the voltage signal also decreased in their magnitudes. The inherent arc instability in a dc thermal plasma torch seems to be suppressed by a diamagnetic effect of the arc column. Furthermore, the measured voltage wave forms indicated that the arc root attachment mode would be controllable by a transverse magnetic field.

CdSe Quantum Dot-Sensitized TiO2 Electrodes: Effect of Quantum Dot Coverage and Mode of Attachment

We have investigated the sensitization of nanoporous titanium dioxide by previously synthesized CdSe quantum dots (QDs) protected with trioctylphosphine. Covering the nanoporous TiO2 films with QDs has been achieved using two strategies: (i) direct adsorption from dichoromethane dispersions and (ii) anchoring the QDs through a molecular linker, concretely, mercaptopropionic acid (MPA). In contrast with MPA-mediated adsorption, direct adsorption leads to a high degree of QD aggregation, as revealed by atomic force microscopy (AFM) images obtained with both TiO2 nanoporous films and monocrystalline surfaces. Importantly, at saturation, only 14% of the real surface area of a 5-μm thick P25 TiO2 layer is covered for both attachment modes. For MPA attachment, the incident photon-to-current efficiency (IPCE) increases with the loading, whereas a maximum (close to 40% at the QD excitonic peak) is defined for intermediate coverages in the case of QD direct adsorption. In addition, for equivalent QD loading, IPCE ...

Cardiac Output During High Afterload Artificial Lung Attachment

Attachment of thoracic artificial lungs (TALs) can increase right ventricular (RV) afterload and decrease cardiac output (CO) under certain conditions. However, there is no established means of predicting the extent of RV dysfunction. The zeroth harmonic impedance modulus, Z0, was thus examined to determine its effectiveness at predicting CO during high afterload TAL attachment. The MC3 Biolung was attached in four adult sheep groups based on baseline (BL) pulmonary vascular resistance and TAL attachment mode: normal, parallel (n=7); normal, series (n=7); chronic pulmonary hypertension, parallel (n=5), and chronic pulmonary hypertension, series (n=5). The resistance of each attachment mode was increased incrementally and instantaneous pulmonary system hemodynamic data were acquired at each increment. The change in Z0 from BL, DeltaZ0, and percent change in CO (DeltaCO%) were then calculated to determine their relationship. The DeltaCO% varied significantly with DeltaZ0 (p<10(-40)) and DeltaZ02 (p<10(-4)) but not with the attachment and pulmonary hemodynamics group. The relationship between the variables for all sheep groups was DeltaCO%=0.215DeltaZ0(2)-7.14DeltaZ0+2.94 (R2=0.82) for DeltaZ0 in mm Hg/(L/min). Therefore, Z0 is an effective index for determining the CO during TAL attachment in both attachment modes with and without elevated pulmonary vascular resistance.

A Simple Strip Model in the Volume-Surface Integral Equation for Analysis of Arbitrary Probe-Fed Conformal Microstrip Antennas

A strip model is incorporated in the volume-surface integral equation (VSIE) to simplify the analysis of the probe-fed conformal microstrip antennas (CMSAs) with arbitrary shapes. The thin wire-surface junction of the feeding probe and the patch is transferred to the surface-surface junction that can be modeled by using Rao-Wilton-Glisson (RWG) basis functions easily. Thus, the use of complicated attachment mode basis function in the conventional VSIE is eliminated, which simplifies the calculation of the method-of-moments (MoM) matrix. The construction of RWG basis functions at the surface-surface junction is detailed as well. An effective remedy is also proposed to overcome the computation breakdown in the near-singularity treatment when the field point locates at the extension of one side of the source domain. Numerical results show the reliability and accuracy of the proposed method.

Interface‐reduction for the Craig–Bampton and Rubin method applied to FE–BE coupling with a large fluid–structure interface

AbstractComponent mode‐based model‐order reduction (MOR) methods like the Craig–Bampton method or the Rubin method are known to be limited to structures with small coupling interfaces. This paper investigates two interface‐reduction methods for application of MOR to systems with large coupling interfaces: for the Craig–Bampton method a direct reduction method based on strain energy considerations is investigated. Additionally, for the Rubin method an iterative reduction scheme is proposed, which incrementally constructs the reduction basis. Hereby, attachment modes are tested if they sufficiently enlarge the spanned subspace of the current reduction basis. If so, the m‐orthogonal part is used to augment the basis. The methods are applied to FE–BE coupled systems in order to predict the vibro‐acoustic behavior of structures, which are partly immersed in water. Hereby, a strong coupling scheme is employed, since for dense fluids the feedback of the acoustic pressure onto the structure is not negligible. For two example structures, the efficiency of the reduction methods with respect to numerical effort, memory consumption and computation time is compared with the exact full‐order solution. Copyright © 2008 John Wiley &amp; Sons, Ltd.

Distribution, habitat use and ecology of deepwater Anemones (Actiniaria) in the Gulf of Mexico

Abstract The distribution of deepwater Actiniaria is poorly known. Rarely are these organisms identified to family, as this requires both well-preserved specimens and taxonomic expertise. Ecological information is similarly lacking. From the results of a comprehensive surveying program in the deep Gulf of Mexico, we report the occurrence of nine species of Actiniaria. For the most abundant four of these, we plot distributions and discuss habitat use, morphological variation, and feeding strategies. Actiniaria in the Gulf appear to have broad, basin-wide distributions with little depth preference. Faunal biomass is highest in the NE Gulf within submarine canyons or at the base of slope escarpments. Attachment mode is mostly opportunistic on various types of hard substrata, including trash. Sediment-dwelling forms are very abundant at an organically rich site within a large submarine canyon.

Excitation of an Infinite Microstrip Line With a Vertical Coaxial Feed

An efficient method is presented for the analysis of a vertical coaxial probe excitation of an infinite microstrip line. The novel feature of the method is that it uses a semianalytical Green's function that is derived for current sources in the presence of the infinite microstrip line. Hence, in a method of moments approach, unknown currents need only be placed on the conducting probe feed and not on the infinite strip surface. The method also utilizes an attachment mode at the contact point between the probe and line so that the correct Kirchhoff condition is automatically satisfied. Once the surface current density on the probe is known, the surface current density on the strip conductor can be readily obtained using the Green's function of the background grounded substrate. The method is valid even at high frequency, where simple transmission line theory fails to account for effects such as the continuous-spectrum current that is excited on the line. After validating the method with various commercial software simulation packages, results are presented to study the fundamental behavior of the input impedance, probe current, and current launched on the microstrip line, and to examine the high-frequency behavior of these currents.