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The heterogeneous assembly of colloidal polymer particles on the nano- and microstructures of a metal is a versatile platform for adjusting the mechanical and electrical properties simultaneously. The assemblies of silver (Ag) microrods and flower-like zinc oxide (ZnO) microparticles with poly(methyl methacrylate) (PMMA) nanospheres are presented to prepare advanced composite materials. PMMA nanoparticles are prepared via the emulsion polymerization technique using a microfluidic preparation step in the presence of cationic surfactant. The surface charge of PMMA particles determines the binding interaction strength with inorganic constituents. Ag microrods and ZnO microparticles are prepared in a batch and in a continuous flow process, respectively. The assembling process can be explained by a particle-particle binding process due to the electrostatic interaction for both types of nanoassemblies. The observed binding pattern reveals certain lateral mobility of the small polymer particles at the surface of larger metal particle. The particle ratios in the nanoassemblies can be tuned over a wide range by changing the reaction parameters. [ABSTRACT FROM AUTHOR]

Abstract: Well-defined Pd nanodendrite assemblies (Pd-NDAs) with high surface area are successfully synthesized through a facile cyanogel-reduction route in the absence of surfactant. The detailed morphology, composition and structure of the Pd-NDAs are thoroughly investigated by various characterization methods, demonstrating that the Pd-NDAs are highly porous and self-supported structures. Cyclic voltammetry, CO-stripping and chronoamperometry tests show that the Pd-NDAs exhibit superior electrocatalytic activity and stability for the formic acid oxidation under acidic conditions, which make them promising anodic electrocatalysts for the future. [Copyright &y& Elsevier]

Linear polysilanes, [{PhHSi} x{Ph(RSCH2CH2CH2)Si}1− x] n [R = n-dodecyl ( 1), n-hexyl ( 2), n-butyl ( 3)], have been synthesized and their reactivity with HAuCl4·3H2O (Polymer:Au = 10:1, RT, toluene) examined to gain an insight into the role of polymer-supported thioether groups in the stabilization of in situ generated gold nanoparticles (AuNPs). The method allows a simple approach for expeditious synthesis of assemblies of AuNPs comprising of well-separated individual nanoparticles of average diameter 4.5 ± 1.9 nm. In this regard, polysilane 1 with dodecyl side chains serves as a superior matrix than 2 and 3 and confers long shelf-life stability to the nanoparticle assembly. The structural attributes are preserved in Au-Pd bimetallic nanoparticles which have been synthesized from the polymer-gold nanoassembly. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013 [ABSTRACT FROM AUTHOR]

Microfiber assemblies prepared from ellagic acid (EA) were functionalized with histidine (His) and dispersed in hyaluronic acid (HA) hydrogel microstructures. Swelling studies indicated that the hybrids had a relatively lower water uptake compared to HA and was pH dependent. The percentage swelling ratio for EA-His-HA hybrids was 48 % when 0.04 mg/mL of HA was incorporated and increased to 70 % when 1.2 mg/mL HA was integrated. Release studies using the dye crystal violet (CV) as a model drug showed that the rates were concentration-dependent. Further the hybrids were found to be thermally stable compared to HA. Cellular toxicity assays performed with normal rat kidney (NRK) cells indicated biocompatibility and adherence of the hybrids to the cells. Thus, we have developed a new family of hybrid hydrogels which readily formed on the EA-His functionalized microfibers and may have potential applications in drug delivery or tissue regeneration applications. [ABSTRACT FROM AUTHOR]

The separation of surface-enhanced raman scattering (SERS)-active Ag-multi-nanoparticle (NP) assemblies by low melting point agarose gel electrophoresis was accomplished here by controlling surface charge using NP capping agents, and the pore size of agarose gel matrix. Detailed transmission electron microscopy analysis of excised gel fractions showed dimers and small clusters to have the greatest SERS activity and a mobility in between the monomers and large aggregates. This strategy enables one to: (1) stabilize small multispherical Ag clusters against further aggregation during purification; (2) fractionate and recover spherical assemblies by nuclearity; and (3) analyze SERS-enhancements for each fraction to optimize purification conditions. [ABSTRACT FROM AUTHOR]

In this study, we probed the biomimetic formation of gallic acid (GA)-ZnO nanoparticle hybrids. It was found that the morphologies formed were dependent upon pH values, resulting in GA-ZnO hybrids of varying shapes such as micro or nanoplates or fibers. The formed supramolecular GA-ZnO hybrids were found to be luminescent as indicated by confocal microscopy and were utilized for the photocatalytic degradation of the organic dye methylene blue. We also explored the bactericidal effects of the hybrids on Staphylococcus aureus ( S. aureus) as well as Escherichia Coli ( E. Coli). Thus, we have developed a new class of shape-controlled nanohybrid assemblies via mild, green synthetic methods that may be utilized for photocatalytic degradation for environmental remediation as well as for antibacterial applications. [ABSTRACT FROM AUTHOR]

Abstract: The aim of the present work is to present an efficient numerical tool for the simulation of the behavior of 3D assemblies of structures with contact and friction when strong structural modifications occur. The paper focuses on the effects of missing connection elements (screws, bolts, rivets, …) on the behavior of the assembly. A fast and efficient domain decomposition strategy for predicting the responses of an assembly for different configurations of missing elements is proposed. The efficiency is provided by the use of a pre-calculated solution as initialization for the calculation of a new design configuration. Applications are concerned with bolted joints under quasi-static loads. [Copyright &y& Elsevier]

This profile looks at the emergence of the 15M Movement in Spain. It analyses the role played by social networks in the movement's formation and identifies the grievances that mobilised a broad coalition of groups and individuals including dissatisfaction with the two-party political system, the venality of political and economic elites, widespread corruption, the economic crisis and the politics of austerity. The profile also looks at the action repertoire employed by the movement and its organisational structure. In terms of the former, it focuses attention on the role played by protest camps and assemblies in giving a voice to the excluded and building the bonds of solidarity necessary to sustain activists through protest. In terms of organisation, it describes a structure that is highly decentralised, has been influenced by protest movements in other parts of the world such as Latin America and has marked regional differences. It concludes with observations about what the 15M means for Spanish politics and the direction it might take in its struggle against the political and economic elites that have dominated Spain since the transition to democracy in the 1970s. [ABSTRACT FROM AUTHOR]

Abstract: The metal derivatives (CoII, NiII, CuII, ZnII and SnIV) of hexaporphyrinato cyclotriphosphazene systems were prepared by treating the hexaporphyrin assembly on cyclotriphosphazene ring with the appropriate metal salt under standard metallation conditions. The complete metallation of all six porphyrin units in hexaporphyrin assembly required 10–12h reflux as judged by the absorption spectroscopy. The metal derivatives were confirmed by molecular ion peak in mass spectra for all compounds. 31P and 1H NMR spectra for Ni(II), Zn(II) and Sn(IV) derivatives and ESR spectra for Cu(II) derivative also confirmed the complete metallation of all six porphyrin units. The hexametalloporphyrin assemblies are freely soluble in common organic solvents. The spectral, electrochemical and fluorescence studies indicate that the six porphyrin units in assemblies interact very weakly and retain their individual characteristic features in the ground and excited states. [Copyright &y& Elsevier]

Copolymers of N-isopropylacrylamide and octadecyl acrylate (PNO), of which the content of octadecyl acrylate (ODA) was 1.3% (PNO 1.5), 1.7% (PNO 2.0), and 3.0% (PNO 4.0), were prepared using a free radical reaction. Various assemblies were obtained depending on the concentration of PNOs and the contents of ODA. Hydrophobic interaction between ODA residues is likely to act as crosslinker. PNO 1.5 formed hydrogel at the concentration of 7%. With PNO 2.0, hydrogels were formed when the concentration was 5 and 7%. With PNO 4.0, the opaque gel was obtained when the concentration was 7%. Upon heating across the lower critical solution temperature, the hydrogels shrank but the opaque gel was broken down into a suspension. At 40°C, the release degrees of fluorescein isothiocyanate-dextran were much smaller than those of release at 23°C. The temperature-sensitive release is due to temperature-sensitive swelling ratio. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011 [ABSTRACT FROM AUTHOR]

The plenary courts of Alfonso VIII of Castile (1158-1214) have not been studied in depth by his biographers, nor by those interested in the early history of parliamentary assemblies, yet their function, composition and frequency reveal interesting aspects in the dynamics of institutional change and the relationship between the monarchy and the aristocracy. These courts became an important instrument for the centralisation of governance; their political relevance is clearly recognised in the commemorative clauses of some royal diplomas, but has been generally overlooked by scholars more concerned with constitutional landmarks and parliamentary developments. The present study will address the institutional nature and political importance of the great courts summoned by Alfonso VIII, from the great court of Burgos in 1169 to that of Carrion de los Condes in 1188, gatherings that served to publicise two crucial moments in his long reign: the coming of the king's majority, and his consolidation as an Iberian leader. [ABSTRACT FROM AUTHOR]

This article investigates relations between qadis and local assemblies in the Touat in the Algerian Sahara. It argues that both drew on an Islamic framework of reference, even though they were frequently obliged to conjugate universal legal injunctions with local notions of overriding communal responsibility that had no place in Islamic law. Islamic notions of private property remained central to the functioning of local assemblies, in which political rights depended on ownership rather than residence. Meanwhile, qadis necessarily relied on the assembly as a source of expertise, for the validation of documents and judgments, and for political and at times also financial backing. Tensions did occur between individual rights of ownership and collective responsibilities, but assemblies and qadis tended to deal with them in similar ways. [ABSTRACT FROM AUTHOR]

Abstract: Air intrusion through roof assembly is a concern for wind uplift resistance and life-cycle performance of roofs. Airflow control is usually achieved by the installation of an air barrier/retarder in the roofing assembly. Even though the concept of air barrier/retarder and air barrier systems has been around for decades, it is still considered a new notion to the roofing industry. Currently, there are no widely accepted standard specifications or test methods to determine air intrusion through roofs or roof assemblies. An experimental procedure has been under development at the National Research Council of Canada to quantify the air intrusion of roof assemblies. As part of this investigation, five roofing assembly configurations were quantified for air intrusion. Relative performance of the air retarding effect of the five assemblies indicated that assemblies with air barrier/retarder had lower air intrusion rates than without. Measured air intrusion rates are compared with the existing codes of practice and standards. This comparison clearly demonstrates the significance of air intrusion into the roofing assembly and the necessity of a standardized air intrusion test method for the roofing industry. With the measured data, attempts were made to perform thermal load calculations using a simplified procedure, and through two case studies the impact of air intrusion through roofing assemblies on energy performance was estimated. [Copyright &y& Elsevier]

Abstract: Semi-circular shaped ZnO nanowhiskers assemblies were fabricated on a substrate by a simple bottom-up approach using an aqueous solution at 88°C. The substrate was coated with ZnO seeds derived from the thermal decomposition of zinc nitrate hexahydrate at 350°C. A 200-mL aqueous solution of 0.1mol/L zinc nitrate hexahydrate, 0.1mol/L hexamethylenetetramine, and 0.02mol/L polyethylenimine was used for depositing ZnO nanowhiskers. X-ray diffraction (XRD) and a field emission scanning electron microscope (FE-SEM) were used to characterize phase and orientation, and morphology and microstructure, respectively. The pre-existing aggregated ZnO nanosheets on the substrate promoted heterogeneous nucleation and growth of ZnO nanowhiskers assemblies preferentially orientated along the c-axis direction, resulting in the formation of the semi-circular shape. [Copyright &y& Elsevier]

This paper discusses the factors that affect the fire resistance performance of lightweight wood frame unrestrained floor assemblies protected with Type X gypsum board ceiling finishes. Twenty-two fire resistance experiments were conducted on full-scale load-bearing wood joist floor assemblies using the ULC standard fire exposure time–temperature curve that is similar to ASTM E119 standard. Parameters investigated in this study include the effects of gypsum board screws spacing from board edges, insulation installation, insulation type, joist spacing for assemblies with gypsum board attached to resilient channels, joist depth, resilient channel installation, resilient channel spacing, sub-floor topping, number of sub-floor layers, and load magnitude. The impact of these parameters on the fire resistance of wood joist frame floor assemblies is discussed. The fire resistance of wood frame floors appears essentially to be governed by the gypsum board screw spacing from the board edges and the type of insulation in assemblies with one layer of gypsum board and by the resilient channel spacing and the gypsum board screw spacing from the board edges in assemblies with two layers of gypsum board. The effects of other parameters in assemblies with two layers of gypsum board such as the joist spacing where the gypsum boards are attached to resilient channels, installation of resilient channels, insulation installation, insulation type, adding gyp-crete topping above the sub-floor and number of sub-floor layers on fire resistance are relatively insignificant. [ABSTRACT FROM AUTHOR]

Abstract: Within the framework of composite structures crashworthiness, bearing rupture specific to composite riveted joints shows an interesting potential insofar this benign failure mode exhibits relevant energy absorption capacities. Therefore, one could anticipate using such properties as a contributing mechanism to address safety in transportation vehicles where composite materials are increasingly introduced. As a contribution to this scientific and economical challenge, the presented paper aims at analysing mechanisms involved in the bearing fracture of composite assemblies. An experimental ASTM procedure is therefore first adapted to the studied material, in terms of specimen dimensions. This new protocol is then applied to conduct a comprehensive static experimental study focused on the analysis of the influence of the number of inter-ply interfaces on bearing properties. The results confirm the strong influence of this parameter on the initiation of bearing failure in composite laminates. [Copyright &y& Elsevier]

In North America, approximately one-fourth of low-slope buildings are roofed with a mechanically attached assembly (MAA) with a single-ply membrane. During wind suctions, the membrane can lift and billow. This creates localized suction under the membrane. If design provisions are not made to control the air intruison at the deck level, this suction pressure can draw the indoor conditioned air into the assembly. Two main factors influence the air intrusion: the air permeability of the components and shape or volume changes during the wind uplift. Available standard test procedures can quantify the former for roof materials. However, there is no widely accepted standard specification or test to address the air intrusion characteristics of roofing assemblies. Air leakage measurement techniques used for walls are also not applicable for roof assemblies due to the membrane shape and volume changes in the roof assembly. Research efforts are under way at the National Research Council of Canada to quantify the air intrusion rate of roof assemblies. This paper presents the details of the experimental setup, test procedure, and validation effort of this newly developed test method. [ABSTRACT FROM AUTHOR]

This paper presents a method to determine whether an assembly of planar parts will stay assembled as it is pushed over a support surface. For a given pushing motion, an assembly is classified into one of three categories: (P = possible): any force necessary to preserve the assembly can be generated by the pushing contacts; (I = impossible): pushing forces cannot preserve the assembly; and (U = undecided): pushing forces may or may not be able to preserve the assembly. This classification is made based on the solution of linear constraint satisfaction problems. If the part-part and part-pusher contacts are frictionless, motions labeled P are guaranteed to preserve the assembly. The results are based on bounds on the possible support friction acting on individual parts in the face of indeterminacy in the distribution of support forces. Experimental results supporting the analysis are given. [ABSTRACT FROM AUTHOR]

Geometric Reasoning ability is central to many applications in CAD/CAM/ CAPP environments. An increasing demand exists for Geometric Reasoning systems which evaluate the feasibility of virtual scenes specified by geometric relations. Thus, the Geometric Constraint Satisfaction or Scene Feasibility (GCS/SF) problem consists of a basic scenario containing geometric entities, whose context is used to propose constraining relations among still undefined entities. If the constraint specification is consistent, the answer of the problem is one of finitely or infinitely many solution scenarios satisfying the prescribed constraints. Otherwise, a diagnostic of inconsistency is expected. The three main approaches used for this problem are numerical, procedural or operational and mathematical. Numerical and procedural approaches answer only part of the problem, and are not complete in the sense that a failure to provide an answer does not preclude the existence of one. The mathematical approach previously presented by the authors describes the problem using a set of polynomial equations. The common roots to this set of polynomials characterizes the solution space for such a problem. That work presents the use of Groebner basis techniques for verifying the consistency of the constraints. It also integrates subgroups of the Special Euclidean Group of Displacements SE(3) in the problem formulation to exploit the structure implied by geometric relations. Although theoretically sound, these techniques require large amounts of computing resources. This work proposes Divide-and-Conquer techniques applied to local GCS/SF subproblems to identify strongly constrained clusters Of geometric entities. The identification and preprocessing of these clusters generally reduces the effort required in solving the overall problem. Cluster identification can be related to identifying short cycles in the Spatial Constraint graph for the GCS/SF problem. Their preprocessing uses the aforementioned Algebraic Geometry and Group theoretical techniques on the local GCS/SF problems that correspond to these cycles. Besides improving the efficiency of the solution approach, the Divide-and-Conquer techniques capture the physical essence of the problem. This is illustrated by applying the discussed techniques to the analysis of the degrees of freedom of mechanisms. [ABSTRACT FROM AUTHOR]

This paper examines the use of a series of three low tech interactive assemblies that have been exhibited by the authors in a range of fairs, expositions and galleries. The paper does not present novel technical developments, but rather uses the low tech assemblies to help scope out the design space for CSCW in museums and galleries and to investigate the ways in which people collaboratively encounter and explore technological exhibits in museums and galleries. The bulk of the paper focuses on the analysis of the use of one interactive installation that was exhibited at the Sculpture, Objects and Functional Art (SOFA) Exposition in Chicago, USA. The study uses audio-visual recordings of interaction with and around the work to consider how people, in and through their interaction with others, make sense of an assembly of traditional objects and video technologies. The analysis focuses on the organised practices of ‘assembly’ and how ‘assembling’ the relationship between different parts of the work is interactionally accomplished. The analysis is then used to develop a series of ‘design sensitivities’ to inform the development of technological assemblies to engender informal interaction and sociability in museums and galleries. [ABSTRACT FROM AUTHOR]

This paper presents a dedicated approach to the calculation of the random response of assemblies with uncertain interface characteristics. The random response is constructed using a polynomial chaos expansion (PCE). A decomposition of the assemblies into substructures and interfaces is defined and associated with a dedicated computational strategy which leads to a local/global algorithm enabling the treatments of the substructure and of the interface problems to be uncoupled. Since the only uncertain parameters are those which appear in the interface equations, this approach results in a drastic reduction of the computational costs. This paper first presents the classical stochastic finite element strategy for this kind of problem, then details the proposed dedicated approach. The applications concern structures assembled with uncertain elastic bonded joints. The proposed approach is compared to the Monte Carlo method and to the stochastic finite element method. [Copyright &y& Elsevier]

Binding energies of the interaction of collagen like triple helical peptides with a series of polyphenols, viz. gallic acid, catechin, epigallocatechingallate and pentagalloylglucose have been computed using molecular modelling approaches. A correlation of calculated binding energies with the interfacial molecular volumes involved in the interaction is observed. Calculated interface surface areas for the binding of polyphenols with collagen-like triple helical peptides vary in the range of 60-210 Å and hydrogen bond lengths vary in the range of 2.7-3.4 Å. Interfacial molecular volumes can be calculated from the solvent inaccessible surface areas and hydrogen bond lengths involved in the binding of polyphenols to collagen. Molecular aggregation of collagen in the presence of some polyphenols and chromium (III) salts has been probed experimentally in monolayer systems. The monolayer arrangement of collagen seems to be influenced by the presence of small molecules like formaldehyde, gluteraldehyde, tannic acid and chromium (III) salts. A fractal structure is observed on account of two-dimensional aggregation of collagen induced by tanning species. Atomic force microscopy has been employed to probe the topographic images of two-dimensional aggregation of collagen induced by chromium (III) salts. A case is made that long-range ordering of collagen by molecular species involved in its stabilisation is influenced by molecular geometries involved in its interaction with small molecules. [ABSTRACT FROM AUTHOR]

The main goals of quality management in all industries are customer satisfaction by delivery of defect-free products, the radical reduction of defect rates and also of quality costs in the production. Controlled technological processes are the most important way to reach these goals. These principles are standard in mechanical engineering and are in use with great success. But the properties in electronics productions are different from the properties in mechanical engineering companies. The processes are difficult and many environmental influences act on these processes. These influences are very strong, especially in case of producing small batches of assemblies (high mix-low volume). Some processes can become uncontrolled and the defect rates may go up. What can we do with these processes? This paper will give you an answer to this question. It describes quality cost models to compare the quality behaviors of different technological processes and of different inspection strategies (no inspection/statistical process control (SPC)/100% inspection). The quality costs are the "measurement system" to compare the different inspection strategies with each other. The costs are calculated by the use of mathematical models-the quality cost models. These models contain also the influence of pseudo defects and defect flow at the inspection processes. [ABSTRACT FROM PUBLISHER]