JOURNAL OF PHYCOLOGY, Issue 2 2006

The effects of phosphate (P) limitation, varying salinity (5,65 psu), and solid media growth conditions on the polysaccharides produced by the model diatom, Phaeodactylum tricornutum Bohlin were determined. Sequential extraction was used to separate polymers into colloidal (CL), colloidal extracellular polymeric substances (cEPS), hot water soluble (HW), hot bicarbonate soluble (HB), and hot alkali (HA) soluble fractions. Media-soluble polymers (CL and cEPS) were enriched in 4-linked mannosyl, glucosyl, and galactosyl residues as well as terminal and 3-linked xylosyl residues, whereas HW polymers consisted mainly of 3-linked glucosyl as well as terminal and 2,4-linked glucuronosyl residues. The HB fraction was enriched in terminal and 2-linked rhamnosyl residues derived from the mucilage coating solubilized by this treatment. Hot alkali treatment resulted in the complete dissolution of the frustule releasing 2,3- and 3-linked mannosyl residues. The fusiform morphotype predominated in standard and P-limited cultures and cultures subjected to salinity variations, but growth on solid media resulted in an enrichment of the oval morphotype. The proportion and linkages of 15 residues, including neutral, uronic acid, and O -methylated sugars, varied with environmental conditions. P limitation and salinity changes resulted in 1.5- to 2.5,fold increase in carbohydrate production, with enrichment of highly branched/substituted and terminal rhamnose, xylose, and fucose as well as O -methylated sugars, uronic acids, and sulfate. The increased deoxy- and O -methylated sugar content under unfavorable environments enhances the hydrophobicity of the polymers, whereas the anionic components may play important roles in ionic cross-linking, suggesting that these changes could ameliorate the effects of salinity or P-stress and that these altered polysaccharide characteristics may be useful as bioindicators for environmental stress. [source]

IDENTIFYING CAUSALITY IN PUBLIC INSTITUTIONAL CHANGE: THE ADAPTATION OF THE NATIONAL ASSEMBLY FOR WALES TO THE EUROPEAN UNION

PUBLIC ADMINISTRATION, Issue 2 2008
CAITRÍONA A. CARTER
The aim of this article is to identify causes and effects of public institutional change. Analysis is centred on those endogenous, not exogenous, sources of political change that account for the institutional metamorphosis of the Welsh Assembly in its engagement with UK-EU processes since 1999. The central research question addressed is to explain a qualitative shift in the logic of action of Assembly engagement, resulting in the conduct of a territorially sensitive ,parliamentary' EU scrutiny, but within a model of executive devolution. To capture agency and change, and to engage with sociological institutionalist debates, the article develops analytical tools of ,framing' and ,operationalizing' institutions to study the interplay between informal and formal processes of institution building since devolution. In so doing, we place refined sociological conceptions of institutions at the heart of analyses of political discontinuity and theorization of public institutional change. [source]

Improved Detection Limit and Stability of Amperometric Carbon Nanotube-Based Immunosensors by Crosslinking Antibodies with Polylysine

ELECTROANALYSIS, Issue 2 2008
Vito Cataldo
Abstract Amperometric immunosensor configurations featuring covalently bound anti-biotin antibodies (Ab) embedded into a polylysine (PLL)-single walled carbon nanotube (SWCNT) composite layer were evaluated. Assemblies were made by first oxidizing pyrolytic graphite (PG) electrodes to form surface carboxylic acid groups, to which PLL, SWCNTs and anti-biotin were covalently linked. Incorporating SWCNT into PLL-antibody assemblies improved the amperometric detection limit for biotin (Ag) labeled with horseradish peroxidase to 10,fmol mL,1. Anti-biotin embedded into the PLL matrix had improved thermal stability and retained its binding ability for biotin after exposure to temperatures of 42,°C for up to 3 hours, while the noncrosslinked antibody was inactivated at this temperature in several minutes. [source]

Electrochemical Biosensors Based on Layer-by-Layer Assemblies

ELECTROANALYSIS, Issue 18 2006
Wei Zhao
Abstract Layer-by-layer (LBL) assemblies, which have undergone great progress in the past decades, have been used widely in the construction of electrochemical biosensors. The LBL assemblies provide a strategy to rationally design the properties of immobilized films and enhance the performance of biosensors. The following review focuses on the application of LBL assembly technique on electrochemical enzyme biosensors, immunosensors and DNA sensors. [source]

Magneto,Structural Correlations in Discrete MnII -WV Cyano-Bridged Assemblies with Polyimine Ligands

EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 26 2010
Robert Podgajny
Abstract We present the magneto,structural correlations for two novel discrete cyano-bridged assemblies based on cationic complexes of manganese(II) with diimine ligands and octacyanotungstate(V) ions. The crystal structure of [MnII(terpy)(dmf)(H2O)2][MnII(terpy)(H2O)(dmf)(,-NC)WV(CN)7]2·6H2O (1) (terpy = 2,2,;6,,2,-terpyridine, dmf = dimethylformamide) contains dinuclear {MnIIWV}, cyano-bridged anions, while the crystal structure of [MnII(phen)3]2[MnII(phen)2(,-NC)2WV(CN)6]2(ClO4)2·9H2O (2) (phen = 1,10-phenanthroline) is built of tetranuclear {MnII2WV2}2, square anions. Intramolecular Mn,W magnetic interactions through the cyano bridges are represented by magnetic coupling constants J = ,39 cm,1 for the {MnIIWV}, unit in 1 and J1 = ,25.7 and J2 = ,16.7 cm,1 for the {MnII2WV2}2, unit in 2. J and J1 represent relatively strong W,CN,Mn interactions and are ascribed to the bridges in b positions of TPRS-8 (trigonal prism square-face bicapped) of [W(CN)8]3, polyhedra, favoring the strongest electronic interactions between the d,d orbital of W and the ,* orbitals of CN,, whereas J2 is related to the m vertex of [W(CN)8]3,. The magnetic properties of 1 and 2 are compared with reference compounds and discussed in the context of the type of coordination polyhedra of [W(CN)8]3, as well as the metric parameters of cyano-bridged W,CN,Mn linkages. We found the type of coordination polyhedra and bridging mode of [W(CN)8]3, to be the most important factors influencing the magnitude of the Mn,W magnetic interaction. [source]

Syntheses, Crystal Structures, and the Phase Transformation of Octacyanometallate-Based LnIII,WV Bimetallic Assemblies with Two-Dimensional Corrugated Layers

EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 23 2010
Ai-Hua Yuan
Abstract The reactions between Ln(NO3)3·nH2O and (Bu3NH)3[W(CN)8]·H2O have led to two series of octacyanometallate-based complexes: Ln(H2O)5[W(CN)8] [Ln = La(1), Pr(2), Nd(3), Eu(4), Gd(5)] and Ln(H2O)4[W(CN)8] [Ln = Ho(6), Er(7), Tm(8), Lu(9)]. The crystal structures of 1,9 have two-dimensional corrugated layers in which the LnIII and WV centres are linked in an alternating fashion. Thermogravimetric (TG) and powder XRD results reveal the presence of a phase transformation in the LnIII,WV system with increasing atomic number of the LnIII atoms. [source]

Experimental and Theoretical Evidence of ,-d Interactions in Supramolecular Assemblies Based on TTF-CH=CH-Py Ligands Tethered to Mo6Xi8 Octahedral Molybdenum Halide Cluster Cores

EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 14 2009
Ganesan Prabusankar
Abstract Synthesis, characterization, and physical properties of [Mo6Xi8(TTF-CH=CH-Py)a6]4+ supramolecular assemblies [TTF = tetrathiafulvalene; Py = pyridine; X = Cl (1), Br (2),I (3)] resulting from the reaction between [Mo6Xi8(OSO2CF3)6]2, cluster precursor and TTF-CH=CH-Py ligands were investigated. They are based on the association of the strongly delocalized metallic electron [Mo6Xi8]4+ cluster cores with six redox-active ,-conjugated TTF-CH=CH-Py terminal ligands attached to the Mo clusters through the pyridinyl group. Synergetic ,-d interactions between the organic ligands and the cluster core were experimentally evidenced by electrochemistry and absorption measurements, and corroborated by DFT calculations.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) [source]

Surfactant-Assisted Synthesis and Characterization of Novel Chain-Like CoNi Alloy Assemblies

EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 25 2007
Lu-Ping Zhu
Abstract Novel chain-like CoNi alloy assemblies with a length of up to 6,7 ,m were successfully prepared by a surfactant-assisted hydrothermal synthetic route at 100 °C for 2 h. The individual submicrospheres built from smaller CoNi nanoparticles had a diameter of about 400,500 nm. These microspheres were then integrated to form the novel chain-like CoNi alloy assemblies. The effects of synthetic parameters such as surfactant and solvent on the formation and morphology of CoNi samples were investigated. The experimental results showed that N2H4·H2O and CTA+ play important roles in the formation of the novel chain-like CoNi alloy assemblies. Based on the structural information provided by X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy, selected-area electron diffraction and energy-dispersive X-ray analysis, a growth mechanism was tentatively proposed for the formation of chain-like CoNi alloy assemblies. Magnetic hysteresis measurement revealed that the chain-like CoNi alloy assemblies display ferromagnetic behavior with a saturation magnetization of 96.15 emu/g and a coercivity of 144.75 Oe at room temperature. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007) [source]

Non-Covalent Aggregation of Discrete Metallo-Supramolecular Helicates into Higher Assemblies by Aromatic Pathways: Structural and Chemical Studies of New Aniline-Based Neutral Metal(II) Dihelicates

EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 17 2005
Miguel Vázquez
Abstract Neutral manganese(II), iron(II), cobalt(II), nickel(II), zinc(II) and cadmium(II) complexes with an N -tosyl-substituted N4 -donor Schiff base containing a 4,4'-methylenedianiline residue as spacer [H2La: N,N' -bis(2-tosylaminobenzylidene)-4,4'-methylenedianiline], and the zinc(II) complex with an analogous ligand [H2Lb: N,N' -bis(2-tosylaminobenzylidene)-4,4'-oxodianiline] have been prepared by an electrochemical procedure. FAB and ESI mass spectra of the complexes show peaks due to species corresponding to a general formula [M2(La,b)2 + H]+, thereby suggesting their dinuclear nature. A detailed study of the crystal packing in the unit cell of the zinc(II) complex with H2La shows that the helicates aggregate to form discrete prismatic moieties containing three molecules held together by ,,, and ,,, interactions. Moreover, the ZnII neutral dihelicate with H2Lb forms a 3D network in the solid state due to intermolecular ,-stacking interactions. 1H NMR studies of the diamagnetic compounds reported herein have been performed. Finally, the ligand H2La and its ZnII and CdII complexes have been studied by spectrophotometric and spectrofluorimetric techniques in order to get a better understanding of the formation mechanisms of the complexes and of the nature of their fluorescence emission. Emission studies show that the ZnII and CdII dihelicates with H2La display a green fluorescence in acetonitrile solution (, = 473 nm, , = 0.03 and , = 476 nm, , = 0.01, respectively). (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005) [source]

Photophysical and Energy-Transfer Properties of (Salen)zinc Complexes and Supramolecular Assemblies

EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 12 2003
Kathryn E. Splan
Abstract The absorption, emission, and energy-transfer properties of monomeric and supramolecular (salen)Zn complexes (square and rectangular assemblies) are reported. The monomeric complexes fluoresce in solution, displaying photophysical behavior similar to typical (porphyrin)zinc complexes. Rhenium coordination chemistry is used to assemble molecular rectangles and squares that largely retain the photophysical properties of the parent compounds. Host-guest assemblies obtained by binding a fifth (salen)Zn complex to a tetrakis(salen) square are capable of efficient salen-to-salen electronic energy transfer. Energy transfer flow through these systems can be manipulated by modification of the salen building-block structure. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003) [source]

4-Substituted and 4,5-Disubstituted 3,6-Di(2-pyridyl)pyridazines: Ligands for Supramolecular Assemblies

EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 9 2008
Edwin C. Constable
Abstract The syntheses by inverse electron demand Diels,Alder reactions and characterization of 28 members of a family of 3,6-di(2-pyridyl)pyridazines, functionalized in the 4- or 4,5-positions are reported. Single crystal structural data are presented for four representative derivatives. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008) [source]

Multi-scale Microstructure Characterization of Solid Oxide Fuel Cell Assemblies With Ultra Small-Angle X-Ray Scattering,

ADVANCED ENGINEERING MATERIALS, Issue 6 2009
Andrew J. Allen
Ultra small angle X-ray scattering with synchrotron radiation is applied to assess the pore space of a highly complex solid oxide fuel cell assembly. The instrument permits to record scattering curves covering a size range from 1,nm to several ,m in a fine step width of 15,,m. [source]

Design of Multiresponsive Hydrogel Particles and Assemblies

ADVANCED FUNCTIONAL MATERIALS, Issue 11 2010
Grant R. Hendrickson
Abstract In the realm of soft nanotechnology, hydrogel micro- and nanoparticles represent a versatile class of responsive materials. Over the last decade, our group has investigated the synthesis and physicochemical properties of a variety of synthetic hydrogel particles. From these efforts, several particle types have emerged with potentially enabling features for biological applications, including nanogels for targeted drug delivery, microlenses for biosensing, and coatings for biomedical devices. For example, core/shell nanogels have been used to encapsulate and deliver small interfering RNA to ovarian cancer cells; nanogels used in this fashion may improve therapeutic outcomes for a variety of macromolecular therapeutics. Microgels arranged as multilayers on implantable biomaterials greatly minimize the host inflammatory response to the material. Furthermore, the triggered release of drugs (i.e., insulin) has been demonstrated from similar assemblies. The goal of this feature article is to highlight developments in the design of responsive microgels and nanogels in the context of our recent efforts and in relation to the community that has grown up around this fascinating class of materials. [source]

Investigation of a Novel Catalyst Coated Membrane Method to Prepare Low-Platinum-Loading Membrane Electrode Assemblies for PEMFCs

FUEL CELLS, Issue 2 2009
X. Leimin
Abstract In this work, a novel catalyst coated membrane (CCM) approach,a catalyst-sprayed membrane under irradiation (CSMUI),was developed to prepare MEAs for proton exchange membrane fuel cell (PEMFC) application. Catalyst ink was sprayed directly onto the membrane and an infrared light was used simultaneously to evaporate the solvents. The resultant MEAs prepared by this method yielded very high performance. Based on this approach, the preparation of low-platinum-content MEAs was investigated. It was found that for the anode, even if the platinum loading was decreased from 0.2 to 0.03,mg,cm,2, only a very small performance decrease was observed; for the cathode, when the platinum loading was decreased from 0.3 to 0.15,mg,cm,2, just a 5% decrease was detected at 0.7,V, but a 35% decrease was observed when the loading was decreased from 0.15 to 0.06,mg,cm,2. These results indicate that this approach is much better than the catalyst coated gas diffusion layer (GDL) method, especially for the preparation of low-platinum-content MEAs. SEM and EIS measurements indicated ample interfacial contact between the catalyst layer and the membrane. [source]

Arrays of Inorganic Nanodots and Nanowires Using Nanotemplates Based on Switchable Block Copolymer Supramolecular Assemblies

ADVANCED FUNCTIONAL MATERIALS, Issue 17 2009
Bhanu Nandan
Abstract Here, a novel and simple route to fabricate highly dense arrays of palladium nanodots and nanowires with sub-30,nm periodicity using nanoporous templates fabricated from supramolecular assemblies of a block copolymer, polystyrene- block -poly(4-vinylpyridine) (PS- b -P4VP) and a low molecular weight additive, 2-(4,-hydroxybenzeneazo) benzoic acid (HABA) is demonstrated. The palladium nanoparticles, which are directly deposited in the nanoporous templates from an aqueous solution, selectively migrate in the pores mainly due to their preferential attraction to the P4VP block covering the pore wall. The polymer template is then removed by oxygen plasma etching or pyrolysis in air resulting in palladium nanostructures whose large scale morphology mirrors that of the original template. The method adopted in this work is general and versatile so that it could easily be extended for patterning a variety of metallic materials into dot and wire arrays. [source]

Reduced Surfactant Uptake in Three Dimensional Assemblies of VOx Nanotubes Improves Reversible Li+ Intercalation and Charge Capacity

ADVANCED FUNCTIONAL MATERIALS, Issue 11 2009
Colm O'Dwyer
Abstract The relationship between the nanoscale structure of vanadium pentoxide nanotubes and their ability to accommodate Li+ during intercalation/deintercalation is explored. The nanotubes are synthesized using two different precursors through a surfactant-assisted templating method, resulting in standalone VOx (vanadium oxide) nanotubes and also "nano-urchin". Under highly reducing conditions, where the interlaminar uptake of primary alkylamines is maximized, standalone nanotubes exhibit near-perfect scrolled layers and long-range structural order even at the molecular level. Under less reducing conditions, the degree of amine uptake is reduced due to a lower density of V4+ sites and less V2O5 is functionalized with adsorbed alkylammonium cations. This is typical of the nano-urchin structure. High-resolution TEM studies revealed the unique observation of nanometer-scale nanocrystals of pristine unreacted V2O5 throughout the length of the nanotubes in the nano-urchin. Electrochemical intercalation studies revealed that the very well ordered xerogel-based nanotubes exhibit similar specific capacities (235,mA h g,1) to Na+ -exchange nanorolls of VOx (200,mA h g,1). By comparison, the theoretical maximum value is reported to be 240,mA h g,1. The VOTPP-based nanotubes of the nano-urchin 3D assemblies, however, exhibit useful charge capacities exceeding 437,mA h g,1, which is a considerable advance for VOx based nanomaterials and one of the highest known capacities for Li+ intercalated laminar vanadates. [source]

Balancing Intermolecular and Molecule,Substrate Interactions in Supramolecular Assemblies

ADVANCED FUNCTIONAL MATERIALS, Issue 2 2009
Dimas G. de Oteyza
Abstract Self-assembly of functional supra-molecular nanostructures is among the most promising strategies for further development of organic electronics. However, a poor control of the interactions driving the assembling phenomena still hampers the tailored growth of designed structures. Here exploration of how non-covalent molecule-substrate interactions can be modified on a molecular level is described. For that, mixtures of DIP and F16CuPc, two molecules with donor and acceptor character, respectively are investigated. A detailed study of their structural and electronic properties is performed. In reference to the associated single-component layers, the growth of binary layers results in films with strongly enhanced intermolecular interactions and consequently reduced molecule-substrate interactions. This new insight into the interplay among the aforementioned interactions provides a novel strategy to balance the critical interactions in the assembly processes by the appropriate choice of molecular species in binary supra-molecular assemblies, and thereby control the self-assembly of functional organic nanostructures. [source]

Colloidal Networks: Polymorphic Meniscus Convergence for Construction of Quasi-Periodic Assemblies and Networks of Colloidal Nanoparticles (Adv. Mater.

ADVANCED MATERIALS, Issue 37 2010
37/2010)
Quasi-periodic colloidal networks can be constructed on the basis of polymorphic meniscus convergence (MC) in an air-cavity-embedded, nanocolloidal system, report Sin-Doo Lee and coworkers on p. 4172. Depending on the flow associated with the air-cavities, the colloidal particles are self-organized into nanowires through binary MC, hexagonal networks with Y-junctions through ternary MC and square networks with X-junctions through quaternary MC, reflecting the flow symmetry according to the air-cavity deformation. [source]

Polymorphic Meniscus Convergence for Construction of Quasi-Periodic Assemblies and Networks of Colloidal Nanoparticles

ADVANCED MATERIALS, Issue 37 2010
Sang-Wook Lee
Quasi-periodic colloidal networks are constructed on the basis of polymorphic meniscus convergence (MC) in an air-cavity-embedded, nano-colloidal system. Depending on the flow associated with the air-cavities, the colloidal particles are self-organized into nanowires through binary MC, Y-junctions through ternary MC, and X-junctions through quaternary MC. The colloidal networks in either square or hexagonal form reflect the flow symmetry according to the air-cavity deformation. [source]

A Biomolecular "Ship-in-a-Bottle": Continuous RNA Synthesis Within Hollow Polymer Hydrogel Assemblies

ADVANCED MATERIALS, Issue 6 2010
Andrew D. Price
The use of micrometer-sized, monodisperse polymer hydrogel capsules that act as both microreactors and drug carriers for de novo synthesized RNA is demonstrated (see figure). These capsules are expected to have broad impact as biophysical tools for the study of encapsulated RNA and as new biocompatible delivery vehicles for the cellular delivery of RNA therapeutics. [source]

Tissue Engineering Using Laminar Cellular Assemblies

ADVANCED MATERIALS, Issue 32-33 2009
Joseph Yang
Abstract As proposed in the late 1980s by Langer and Vacanti, the ultimate goal of tissue engineering is the development of structures that can be used to treat or replace damaged or diseased organs and tissues. For the regeneration of various organs such as the heart, liver, and kidney, the development of adequate vascular networks within the engineered tissues remains a significant obstacle in the formation of cell-dense structures that resemble the native parenchyma. While tissue engineering using biodegradable scaffolds has been successful in the re-creation of tissues where extracellular matrix is abundant, we have developed cell-sheet-based tissue engineering for the construction of tissues using laminar assemblies of cells harvested from temperature-responsive culture dishes. Using cell sheet engineering, we present new strategies for the development of organ-like tissue structures containing well-organized vascular networks. [source]

Syntheses of Porous Self-Supporting Metal-Nanoparticle Assemblies with 3D Morphologies Inherited from Biosilica Templates (Diatom Frustules)

ADVANCED MATERIALS, Issue 4 2009
Zhihao Bao
Porous 3D metal-nanoparticle assemblies with selectable morphologies are synthesized. Biosilica templates (diatom frustules) are first converted into silicon replicas via magnesiothermic reduction. Electroless metal deposition, followed by silicon dissolution, then yields metal-nanoparticle assemblies with the 3D template morphology (figure reveals a silver assembly; inset images reveal internal features after partial ion milling and EDX analysis). [source]

Synthesis of Light-Diffracting Assemblies from Microspheres and Nanoparticles in Droplets on a Superhydrophobic Surface,

ADVANCED MATERIALS, Issue 22 2008
Vinayak Rastogi
Aqueous suspension droplets of monodisperse latex or latex and gold nanoparticles mixtures assume spherical shape on superhydrophobic substrates. The drying sessile droplets serve as macroscopic templates for assembling microspheres into closed-packed structures. Upon illumination, the supraparticles display discrete colored rings because of the periodic arrangement of latex particles in the surface layer. The physical origin of the colored patterns is explained in detail. [source]

Fabrication of Precise Fluidic Structures in LTCC

INTERNATIONAL JOURNAL OF APPLIED CERAMIC TECHNOLOGY, Issue 1 2009
Fred Barlow
A number of emerging applications of low-temperature co-fired ceramic (LTCC) require embedded fluidic structure within the co-fired ceramic and or precise external dimensional tolerances. These structures enable the control of fluids for cooling, sensing, and biomedical applications, and variations in their geometry from the design can have a significant impact on the overall performance of the devices. One example of this type of application is a multilayer cooler developed recently by the authors for cooling laser diode bars. In many laser systems, laser diodes are the primary emitters, or assemblies of these diode bars are used to pump traditional laser crystals such as Nd:YLF. Assemblies of these diodes require large amounts of electrical current for proper operation, and the device operating temperature must be carefully controlled in order to avoid a shift in the output wavelength. These diodes are packaged into water-cooled assemblies and by their nature dissipate enormous amounts of heat, with waste heat fluxes on the order of 2000 W/cm2. The traditional solution to this problem has been the development of copper multilayer coolers. Assemblies of laser diodes are then formed by stacking these diode bars and coolers. Several problems exist with this approach including the erosion of the copper coolers by the coolant, a requirement for the use of deionized water within the system, and a significant CTE mismatch between the diode bar and the metal cooler. Diodes are bonded to these metal structures and liquid coolant is circulated through the metal layers in order to cool the diode bar. In contrast, the coolers developed by the authors utilize fluid channels and jets formed within LTCC as well as embedded cavity structures to control the flow of a high-velocity liquid and actively cool the laser diode bars mounted on the surface of the LTCC., The dimensional tolerances of these cooler assemblies and complex shapes that are used to control the fluid can have a significant impact on the overall performance of the laser system. This paper describes the fabrication process used to create the precise channel and jet structures used in these LTCC-based coolers, as well as some of the challenges associated with these processes. [source]

Multicolor Emission from Ordered Assemblies of Organic One-Dimensional Nanomaterials

ADVANCED MATERIALS, Issue 7 2008
Yong Sheng Zhao
No abstract is available for this article. [source]

Self-Assembly and Micropatterning of Spherical-Particle Assemblies,

ADVANCED MATERIALS, Issue 7 2005
Y. Masuda
Spherical-particle assemblies (see Figure) are fabricated by micropatterning of methanol droplets containing SiO2. Hydrophilic regions of a patterned self-assembled monolayer (SAM) are covered with methanol solution containing SiO2 particles and immersed in decahydronaphthalene. The particles assemble to form micropatterns of spherical-particle assemblies on the hydrophilic regions of the SAM. [source]

Linear Assemblies of Silica-Coated Gold Nanoparticles Using Carbon Nanotubes as Templates,

ADVANCED MATERIALS, Issue 23-24 2004
A. Correa-Duarte
Silica-coated gold nanoparticles were assembled on carbon nanotubes by polymer wrapping and layer-by-layer assembly (see Figure). The procedure was applied to ordered arrays of vertically aligned nanotubes, resulting in parallel nanotubes of compact nanoparticle monolayers for potential use in photonics. [source]

Oriented Assemblies of ZnS One-Dimensional Nanostructures ,

ADVANCED MATERIALS, Issue 9-10 2004
Y.-C. Zhu
Oriented ZnS nanobelt arrays and ZnS multicore microcables consisting of oriented nanowire bundles with sheaths (see Figure) have been synthesized via a controlled thermal process. Both the ZnS nanowires and nanobelts are single crystals grown along the [001] axis. The special structures of the oriented assemblies of ZnS one-dimensional nanostructures may have potential applications in nanoelectronics and photonics. [source]

Scanning Probe Studies of Porphyrin Assemblies and Their Supramolecular Manipulation at a Solid,Liquid Interface

ADVANCED MATERIALS, Issue 24 2003
J.A.A.W. Elemans
Dynamic self-assembly and metal,ligand coordination processes of porphyrin hexamers on a solid,liquid interface have been visualized with scanning tunneling microscopy. The organization of these hexamers into stable and highly organized arrays of "edge-on" or "face-on" oriented molecules can be controlled by the addition of different ditopic axial ligands (see Figure). [source]

Assemblies of Metal Nanoparticles and Self-Assembled Peptide Fibrils,Formation of Double Helical and Single-Chain Arrays of Metal Nanoparticles,

ADVANCED MATERIALS, Issue 11 2003
X. Fu
Double helical and single-chain arrays of Au and Pd metal nanoclusters have been achieved by assembling the corresponding metal nanoparticles on peptide nanofibril templates at different pH values. The assembled metal nanoparticles are useful for studying the superstructures of the peptide nanofibrils. Pd nanowires of different shapes have also been prepared by varying the amount of metal deposition. [source]