bluuebunny/crossref_metadata_2025 huggingface dataset:
Nanosize Structure of Sputter-Deposited Tungsten Carbide Thin Films
Authors: Dubček P. , Radić Nenad , Bernstorff S. , Salamon K. , Milat O.
Published: March 2009

The structure of thin films of tungsten-carbon, deposited onto monocrystalline silicon substrates by reactive magnetron sputtering (argon + benzene) in a wide range of preparation parameters has been investigated by GISAXS. Substrates were in a fixed position relative to the two adjacent cylindrical magnetrons. Benzene partial pressure was varied from 1% to 10% of the total working gas pressure. A series of samples were prepared, with the substrate held at room temperature and 400°C, and the substrate potential held at floating potential or biased -70 V with respect to the discharge plasma. The bulk particle contribution to the scattering was investigated outside of the specular plane, applying a two dimensional CCD detector. For higher values of benzene partial pressure, the generated films consist of densely packed tungsten carbide grains in an amorphous, carbon rich matrix, while, in some cases, the lower benzene pressure resulted in isolated carbon rich particles in tungsten carbide. From earlier work it is known that the preparation parameters influence the film’s chemical composition, the relatively complex dependence of particle sizes on benzene partial pressure can be explained as a function of the relative carbon content.
Studies of Multiwall Carbon Nanotubes Using Raman Spectroscopy and Atomic Force Microscopy
Authors: Zdrojek M. , Gebicki W. , Jastrzebski C. , Melin T. , Huczko A.
Published: March 2009

Preliminary results of Raman scattering measurements of multiwall carbon nanotubes (MWCNT) are presented. The nanotubes have been carefully dissolved, separated and then characterized by AFM. The micro-Raman spectra are taken with 514,5nm wavelength excitations in the range 4K - 400K. Basically the spectra are quite similar to the well known single wall carbon nanotube spectra, but the low frequency band is absent. The major Raman bands, observed in single wall nanotubes are found in the spectra. In particular the disorder effects are visible due to the pronounced D band at ~1350 cm-1. Metallic and semiconducting type of conductivity is distinguished through analysis of the G (LO) mode at ~1600 cm-1. A new feature in these spectra exists at ~843 cm-1. Low energy radial breathing mode absence has been explained.
Intersublevel Relaxation Dependence of Carrier Hopping in Self-Organized InAs Quantum Dot Heterostructures
Authors: Wu Y.F. , Shen H.T. , Lin Y.H. , Cheng C.C. , Lin R.M. , Nee Tzer En , Yeh N.T.
Published: March 2009

The temperature dependence of the photoluminescence (PL) emission spectra of
self-organized InAs/GaAs quantum dots (QDs) grown under different growth conditions in the range 20-300K has been investigated. Three InAs QD samples were grown on (100) 2º-tilted toward (111)A Si-doped GaAs substrates by metal-organic chemical vapour epitaxy (MOVPE), with various size uniformities and dot densities. Observing the measured PL spectra at 20K, the differences caused by size uniformities among the three samples were obvious. The PL spectra
were simulated with rate equations, taking into account the carrier relaxation between the first excited state and the ground state. Interestingly, the calculated relaxation lifetimes at 20K were 198ps, 139ps and 54ps for the samples. The temperature dependent PL spectra were also simulated using the same model. Based on the calculated values of temperature dependent relaxation lifetimes, the differences in changes with temperature among the three samples are discussed. The results are consistent with the thermal redistribution effect.
Fabrication of GaSb Microlenses by Photo and E-Beam Lithography and Dry Etching
Authors: Papis E. , Piotrowska Anna , Piotrowski T.T. , Gołaszewska K. , Ilka L. , Kruszka R. , Ratajczak Jacek , Kątcki J. , Wróbel J. , Aleszkiewicz M. , Łukaskiewicz R.
Published: March 2009

Fabrication of surface-relief microstructures in GaSb for application in mid-infrared optoelectronic devices is described. Photo- and e-beam lithography was used to define patterns on GaSb surfaces. Ar/O2 sputter etching and RIE in BCl3-based plasma were applied to transfer preshaped master into the GaSb substrate. Circular microlenses with an aspect ratio (height to diameter) 0.4/10 µm and circular gratings with 0.4 µm linewidth / 1 µm period and 1.7 µm depth have been demonstrated.
Biomineralization: Peptide‐Mediated Synthesis of Materials
Authors: Rutledge Ryan D. , Wright David W.
Published: March 2009

Biomineralization provides many examples of the ambient synthesis of materials. Often associated with these systems are peptide templates. Synthetically, these templates offer tunable entities that can be altered in ways that affect the resulting composition, size, and morphology of the desired material. The development of peptide‐display methods has aided in the expansion of this approach to include many types of abiological substances. Accordingly, this review focuses on the identification and use of peptides involved in the syntheses of a number of different types of materials (metal oxides, calcium carbonate, metallic nanostructures). Covering only the most recent of advances (2004–2007), we examine the control exhibited by peptides free in solution and the ability of researchers to address and alter that control. The effects demonstrated as a result of immobilizing the peptide on a nanostructured or biological surface are discussed. Finally, the future of biomimetic synthesis of nanomaterials is considered in an attempt to gauge where biomineralization is headed and what possibilities it might offer down the road.
Biomineralization: Self‐Assembly Processes
Authors: Yu Shu‐Hong , Chen Shaofeng
Published: March 2009

This article focuses on biomineralization processing involving nanoparticle self‐assembly. Biomineralization is a process of depositing inorganic or inorganic–organic hybrid materials as complex shapes or as hierarchical structures on various size scales having unique properties. Emerging nonclassical crystallization methods of self‐assembly are summarized, including oriented attachment, mesocrystal growth from amorphous precursors, and polymer particle assembly from polymer‐induced liquid precursors. Recent progress in understanding biomineralization in nature and biomimetic mineralization via nanoparticle self‐assembly directed by organic molecules is summarized. Crystallization in organisms commonly involves biopolymer‐induced nucleation and growth, self‐assembly of nanobuilding blocks, and organization of amorphous precursors. A better understanding of biomineralization in organisms and self‐assembly process, in general, will lead to the rational design and synthesis of functional materials having well‐defined hierarchical structures, controlled length scales, and desired properties under environment‐friendly conditions.
Inorganic Semiconductor Nanomaterials for High‐Performance Flexible Electronics
Authors: Ahn Jong‐Hyun , Baca Alfred J. , Rogers John A.
Published: March 2009

This article reviews several classes of high‐quality inorganic semiconductor nanomaterials for high‐performance flexible and stretchable electronics in two‐ or three‐dimensional layouts. Approaches for fabricating inorganic semiconductors in the forms of wires, ribbons, and membranes, and methods for integrating these materials on flexible substrates are presented. Finally, perspectives on the trends for future work related to flexible electronics are described.
Carbon Nanotubes: Fluorinated Derivatives
Authors: Khabashesku Valery N. , Kuznetsov Oleksandr V. , Pulikkathara Merlyn X.
Published: March 2009

Ongoing extensive research on carbon nanotubes (CNTs) has been facilitated by unique physicochemical properties and wide opportunities the CNTs offer for the new field of nanotechnology. Recent studies have shown that for efficient use of the remarkable properties of CNTs, particularly in the design of multifunctional materials for engineering and biomedical applications, they need to be surface modified by attachment of functional groups for improving solubility, processing, and compatability with host materials. It has been shown that fluorination is an efficient way to modify and control the surface properties of CNTs. For instance, fluorine functional groups on the sidewalls of CNTs effectively assist in unroping the nanotube bundles and in dispersion in alcohols and other polar solvents. Weakness of the CF bond and solubility of fluorinated nanotubes (fluoronanotubes) provide an opportunity for the synthesis of a variety of nanotube derivatives by substitution of fluorine through wet chemistry methods. This approach has been applied to preparation of a series of amino, amide, hydroxyl, thiol, and carboxyl group‐terminated derivatives. The activated sidewall CC π bonds in fluoronanotubes also permit a solution‐phase chemistry leading to addition reactions of free radicals, carbenes, dienes, and other reactive molecules. Functional groups chemically attached to the CNTs effectively assist in the dispersion of CNTs in polymer matrices, crucial for nanocomposites fabrication. “Tailored” chemical modifications are particularly useful for creating multiple sites for covalent bonding of nanotubes to polymer matrices for the enhancement of mechanical properties of epoxy, polyethylene, polypropylene, and nylon. Fluorinated CNTs represent a new family of nanoscale fluorocarbon materials. They enable various applications of functionalized CNTs, derived from fluoronanotubes, particularly in nanocomposites, sensors, nanoelectronic devices, nanoengineered drug delivery systems, and nanolubricants.
Carbon Nanotubes, Multi‐Walled
Authors: Andrews Rodney , Weisenberger Matthew C. , Qian Dali , Meier Mark S. , Cassity Kelby , Yeary Paul E.
Published: March 2009

Well‐aligned carbon multiwalled nanotubes (MWNTs) have been synthesized continuously by pyrolysis of xylene–ferrocene mixtures. To study the MWNT growth mechanism, two‐step processes and various chemical vapor deposition (CVD) parameters have been employed. Transmission electron microscopy observations support a tip‐root growth model of MWNTs by floating catalytic CVD. Hydrocarbon analyzer is used to measure the total carbon balance within the CVD reactor, while mass spectra analyses monitor the concentrations of hydrocarbon species, which helps to understand the catalyst deactivation and pyrolysis chemistry of xylene over catalyst Fe(C) nanoparticles. MWNTs can be treated to attach required functional groups on nanotube walls and/or caps for specific applications by various methods including acid oxidation, reduction, addition of radicals, and cycloadditions. Carbon nanotubes (CNTs) have shown promising applications in advanced CNT–polymer composites. To realize CNT potentials to enhance the properties of matrices, several important issues such as dispersion, orientation, interfacial effects, and processing parameters have been addressed. The dependence of the CNT–polymer composite properties on CNT diameter, length, and interfacial effects has been used to develop models to predict and optimize variables for maximum composite performance. CNT–polymer composites have been developed for enhanced mechanical, electrical, and thermal properties, which have wide applications for the next generation of truly multifunctional materials as well as lighter weights and increased manufacturability over current materials.
Liquid‐Phase Synthesis of Inorganic Nanoparticles
Authors: Caruntu Gabriel , Caruntu Daniela , O'Connor Charles J.
Published: March 2009

In this article we review some of the most representative liquid‐phase synthetic methodologies for the preparation of inorganic nanoparticles. Metallic nanoparticles and alloys have been chosen as a model to discuss the preparation of colloidal nanocrystals and their functionalization with organic molecules. Of a particular interest have been the synthetic methodologies allowing not only the compositional control of the nanoparticles but also the size/shape of the nanoparticles along with their ability to organize into hierarchical architectures suitable for different technological applications.
Gold Nanoparticles: Monolayer‐Protected Scaffolds and Building Blocks
Authors: Ofir Yuval , Srivastava Sudhanshu , Rotello Vincent M.
Published: March 2009

Nanoparticles provide key tools for bridging the gap between “bottom‐up” synthetic methods and “top‐down” fabrication. In this article, we describe recent progress in the recognition‐mediated assembly of metal nanoparticles using small molecules and polymers. A significant portion of the article focuses on the interaction of nanoparticles with biological moieties such as peptides and proteins, and the use of nanoparticles as drug and gene carriers for application in biomedical applications.
Nano/Microporous Materials: Crystalline Metal‐Chalcogenide Superlattices
Authors: Lin Zhien , Feng Pingyun , Bu Xianhui
Published: March 2009

This article describes the recent research progress in the field of crystalline metal‐chalcogenide superlattices containing tetrahedron‐shaped nanoclusters as building units. With the development of new synthetic strategies and structural concepts, new clusters that are members of three series of tetrahedral clusters (i.e., supertetrahedral clusters, pentasupertetrahedral clusters, and capped supertetrahedral clusters) have been prepared and organized into extended frameworks with a variety of topologies, such as single diamond, double diamond, ABW, CrB4, SOD, cubic C3N4, UCR‐1, ICF‐24, ICF‐25, α‐ and β‐quartz, moganite, and boracite. These materials show rich compositional diversities with tunable optical properties, microporosity, and ion‐exchange properties, suggesting their potential applications in photocatalysis, fast‐ion conductors, solar cells, etc.
Nanocomposite Materials: Polyhedral Silsesquioxanes
Authors: Seifalian Alexander M. , Kannan Ruben Y. , Ghanbari Hossein , Bakhshi Raheleh
Published: March 2009

The unique properties of nanocomposites have revolutionized the field of materials science. Polyhedral oligomeric silsesquioxane (POSS) is one of the widely used nanostructured materials for the synthesis of hybrid nanocomposites. POSS nanocrystals have been incorporated as building blocks of controllable shapes into polymers to form hybrid materials exhibiting improved properties. A variety of polymerization techniques have been used in the preparation of POSS‐containing hybrids. Incorporation of POSS into polymers can result in substantial improvement in physical properties of the polymers, such as low dielectric constants, increased glass‐transition temperatures, low coefficient of thermal expansion, enhanced thermal stability, mechanical strength, as well as improved oxidation resistance and reduction in flammability, oxygen permeability, heat evolution, and viscosity during processing. The most interesting POSS‐polymer has been the development of POSS–poly(carbonate‐urea)urethane that is used in medical applications owing to its enhanced biocompatibility and antithrombogenesity. These composites are materials of choice in the fabrication of various cardiovascular devices, such as artificial heart valves, stent‐grafts, bypass grafts, microvascular beds, and other biomedical devices including breast implants, and as scaffolds for tissue engineering.
Nanocomposite Materials: Semiconductors in Zeolites
Authors: Goldbach Andreas , Saboungi Marie‐Louise
Published: March 2009

Encapsulation in zeolites holds considerable promise for organizing semiconductor quantum dots and quantum wires into ordered two‐ and three‐dimensional arrays that can be used in a variety of applications. While the use of such materials has been limited until now by a number of practical difficulties, considerable progress has been made in the last few years in surmounting these obstacles. This article reviews recent progress in the field, particularly with regard to stabilization of the nanocomposites against moisture, modulation of their properties by appropriate cation substitution, and preparation of materials in the form of thin films that can exhibit strong nonlinear optical activity. Finally, the article discusses the present perspectives for the field and outlines some research directions that must be pursued for these materials to achieve their full range of potential applications.
Inorganic Nanocrystals: Patterning and Assembling
Authors: Curri Maria Lucia , Comparelli Roberto , Striccoli Marinella , Depalo Nicoletta , Fanizza Elisabetta
Published: March 2009

Recently, increasing interest has been devoted to the study of the size‐dependent properties of inorganic nanocrystals and nanoparticles, in order to investigate and exploit their original potential. The ability to access nanoparticle properties for device fabrication is based on their organization in morphologically controlled assembly and/or ordered arrays, with suitable patterning, in order to bridge the gap between nanoscopic and mesoscopic scale.

Assembly procedures allow the formation of original ordered state of matter and the fabrication of 2‐/3‐D patterned micro‐ and nanostructure, representing a promising route for producing functional materials and for processing and integrating the nanoparticles in macroscopic systems to fully develop their unprecedented functionality for materials and devices for biomedical, electronic, catalytic, and separation process technologies. Top‐down technological methods and techniques, conventional and emerging, have been cleverly and ingenuously combined and matched with dedicated bottom‐up approaches, paying attention to the peculiarity of the nanoparticle size regime. In most approaches, a precise control on the size and shape of the nanoparticles is crucial for driving the assembling and the extent to which the building blocks can be engineered, designed, and fabricated with desired features, including encoded instructions for assembling, has been greatly progressing in the last years. This article focuses on the potential of exploitation of inorganic nanocrystals and nanoparticles for assembling. An overview of the inorganic nanocrystal functions in the different and complementary strategies is outlined, highlighting the novelty and originality of the specific results and placing them in the scenario of the emerging material science, toward the envisioned creation of materials by design.
Semiconductor Nanocrystals: Doped Compositions
Authors: Vela Javier , Hollingsworth Jennifer A.
Published: March 2009

We review the state of the art in the field of semiconductor nanocrystal (SC NC) doping, with emphasis on cationic doping for modified optical and magnetic properties. Doping has the potential to greatly expand the already vast technological promise of SC NCs by allowing for the introduction of dopant‐specific or dopant‐modified properties. In the last several years, tremendous progress has been made with respect to both the understanding and implementation of SC NC–doping strategies. Here, we review the prevailing theoretical models (the “dopant extrusion model” and the “sticky surface model”) underpinning the current understanding of the process of dopant ion incorporation during NC growth. Further, we review the general synthetic approaches that have been developed in the context of this understanding, as well as many specific examples of SC NC–dopant systems, revealing both the successes and those that have fallen short in either achieving doping or fully demonstrating that doping was achieved. In support of this aim, we also provide a summary of the characterization methods (spectroscopic, structural, and chemical) that are critical for critiquing the doped system. We have necessarily focused on cationic doping as anionic doping has yet to be realized in a similar fashion. Further, the topic of electronic doping is only briefly addressed. While examples are reasonably abundant with respect to transition metal and lanthanide doping for modified magnetic/optical and optical properties respectively, permanent electronic doping of SC NCs has yet to be demonstrated. Finally, we identify (in addition to anionic and electronic doping) the topic areas that remain to be explored in this field of SC NC doping.
Molecular and Supramolecular Arrays of the [
Re
6
(μ
3
‐
Se
)
8
]
2+
Core‐Containing Clusters
Authors: Zheng Zhiping
Published: March 2009

Transition metal clusters are a unique class of chemical substances. Not only do they have well‐defined molecular structures, they also exhibit interesting and potentially useful properties that are inherent to metal–metal bonded species. In this contribution, our efforts in developing synthetic methodologies necessary to bring a cluster system out of the limited sphere of fundamental cluster chemistry and into general synthetic applicability are summarized. Specifically, we have explored the uses of site‐differentiated cluster complexes of the [Re
6
(μ
3
‐Se)
8
]
2+
core as stereospecific building blocks for supramolecular construction. A great variety of cluster‐supported molecular and supramolecular architectures have been realized. These include Tinkertoy‐like molecular cluster arrays featuring cluster units bridged by multitopic ligands and supramolecular assemblies of clusters engineered via hydrogen bonding and metal–ligand coordination. Some of these nanoscopic cluster‐containing systems display rather interesting electronic and spectroscopic properties and, therefore, hold great potential in developing molecule‐based electronic and optical materials. The work therefore marks the beginning of what promises to be an exciting new chapter in cluster chemistry.
Functional Supramolecular Hybrid Materials
Authors: Rurack Knut , Martínez‐Máñez Ramón
Published: March 2009

The combination of suitable nanoscopic inorganic supports with supramolecular concepts and bioconjugation strategies opens up exciting perspectives for the development of bioinorganic and organic–inorganic hybrid materials with improved functionalities. Many of the examples from the period 2004 to mid‐2007 reviewed here bridge the gap between molecules, materials sciences, biochemistry, and nanotechnology. The synergistic use of these approaches has led to the advancement of various functions such as enhanced recognition, amplified signaling, the controlled assembly and disassembly of aggregates and 3‐D architectures. Many of the implemented active functions can be carried out in a reversible and directed fashion on purpose by triggering with an external stimulus. These ideas bring tunability to properties of inorganic solids and new perspectives of application to biochemical and supramolecular concepts. Classic inorganic chemistries such as metal or semiconductor nanoparticles, silica or carbon materials, and coordination chemistry are thus elevated to another level of sophistication and contribute significantly to frontier research areas in directed transport and delivery, nanoelectronics and mechanics, chip technology, smart materials, memory devices, and bioanalytics.
Gold Nanoparticles as Chemical Catalysts
Authors: Ma Zhen , Overbury Steven H. , Dai Sheng
Published: March 2009

Gold, often known as being
chemically inert
, has rich inorganic and organic chemistry. In particular, gold nanoparticles, either protected by organic ligands or supported on solid surfaces, have attracted wide attention for their applications in catalysis, electronics, nonlinear optics, and biology. In this article, we summarize some recent advances in the synthesis of supported gold catalysts from the perspective of inorganic materials chemistry. These advances include new methods used to load gold, to prepare functionalized supports, and to postdecorate supported gold catalysts. More recent advances in the use of nanoparticle supports and other ordered nanostructures in making supported gold catalysts are also highlighted, and a critical analysis of the status of the field is presented. From this review, it is hoped that the reader will get an impression that inorganic materials chemistry can contribute to the synthesis of novel gold catalysts with good catalytic performance.
Semiconductor/Ceramic Nanocomposites: Synthesis, Characterization, and Properties
Authors: Moore Joshua T.
Published: March 2009

A survey of the preparation of semiconductor nanocrystal‐ceramic nanocomposite materials and related nanostructured materials is provided. Nanocomposite materials described here contain elemental semiconductors (Si and Ge), II–VI and IV–VI semiconductors (ZnE, CdE, and PbE where E = S, Se, Te), and III–V semiconductors (GaE, AlE, and InE where E = N, P, As) embedded in various ceramic matrices. Semiconductor nanocrystals and nanoparticles were prepared using a variety of physical, chemical, and electrochemical synthesis strategies. Sol‐gel processing, and single‐ or multiple‐source precursors were used to prepare semiconductor nanoparticles with diameters as small as 2–4 nm or as large as 50–200 nm. Formation of the semiconductor nanophase was carried out by reduction of mixed‐metal oxides, pyrolysis of well‐characterized precursor molecules or in situ generated precursor complexes, chemical vapor deposition (CVD), and electrochemical reduction.
Monodisperse Magnetic Nanoparticles: Chemical Synthesis and Surface Modification
Authors: Xie Jin , Sun Shouheng
Published: March 2009

Magnetic nanoparticles, due to their prospective applications in data storage, drug delivery, hyperthermia, and magnetic resonance imaging, have attracted considerable attention in the past decade. From aqueous‐phase condensation to organic‐phase thermal decomposition, the synthesis of magnetic nanoparticles has been greatly improved. Nowadays, one can readily synthesize monodisperse magnetic nanoparticles with controlled sizes, shapes, and magnetic properties. In this article, we first briefly describe the general synthesis of monodisperse nanoparticles, and then focus on the synthesis of magnetic nanoparticles via thermal decomposition of metal precursors. The nanoparticles are grouped into ferrite, metallic, alloy, and multicomponent categories, and the mechanism for the formation of nanoparticles with critical parameters in determining size, shape, and multifunctionality is discussed. We further summarize the chemistry used for nanoparticle surface functionalization and briefly discuss the potential applications of these magnetic nanoparticles in biomedicine.
Endohedral Fullerenes
Authors: Yang Shangfeng , Dunsch Lothar
Published: March 2009

The recent state in endohedral fullerenes is reviewed in terms of both sides of the fullerene: the new carbon cages including non‐IPR (IPR, isolated pentagon rule) structures as well as new species encaged in the inner fullerene void. A general principle is valid nowadays and used in endohedral fullerene research: the stabilizing ability of the encaged structure for the fullerene cage architecture and that of the fullerene cage for the encaged species. Thus, the cage size ranges from C66, the first non‐IPR fullerene cage, to C100while the encaged species are extended up to five atomic clusters as for Sc3C2. The world of endohedral fullerenes was significantly enlarged within the past seven years by the cluster fullerenes containing structures like the M3N nitrides. This review is focused on the new development of this amazing world of carbon nanostructures since 1999, including new structures, properties, and potential applications of endohedral fullerenes as well as prospects.
Inorganic Nanomaterials Synthesis Using Alkalide Reduction
Authors: Wagner Michael J.
Published: March 2009

Chemical (solution) methods of nanomaterial synthesis offer the advantages of simplicity, stoichiometric control, ease of scale‐up, and the possibilities of size control and narrow size distributions. Of the many solution methods of making nanoparticles, the reduction of metal salts by alkalides or electrides, generally referred to asalkalide reduction, is particularly promising due to its ability to protect highly oxyphilic elements and its use of the most power reductants possible in any given solvent. This makes it general across the periodic table including the early transition metals and rare earth elements. In fact, to date, it is the only solution method shown to be capable of synthesizing lanthanide metal nanoparticles. Binary and higher order phase nanomaterials are also possible by the simultaneous alkalide reduction of multiple elements. Nanoscale oxides and nitrides can be formed by reacting nanomaterials made by alkalide reduction with the appropriate gas. Spheroidal nanoparticles as small as ∼1 nm in diameter can be synthesized by this method as can rods up to ∼1 µm in length. The current practice and capabilities of highly versatile synthetic routes to nanomaterials are outlined in this article.
Biomimetic Chemistry of Hybrid Materials
Authors: Rurack Knut , Martínez‐Máñez Ramón
Published: March 2009

The article discusses representative examples published in the field of functional biomimetic chemistry of hybrid materials between 2004 and mid‐2007. First, we focus on the modification of morphological aspects of (bio)organic–inorganic hybrid materials to create sophisticated gating and switching mechanisms. The architecture of the systems is presented and the elements of control by external stimuli that have been established in recent years, such as optical, electrochemical, chemical, thermal, or magnetic means, are described. Various functions ranging from (site‐specific) delivery to indication at the nanometric level are reported. Next we develop the idea of utilizing hybrid frameworks for biomimetic signaling inspired by the way nature has created binding pockets and the concept of induced‐fit. Such a merging of inorganic scaffolds with supramolecular concepts results in enhanced molecular recognition and signaling. Finally selected recent advances in the field of hybrid biomimetic motors both of linear and rotary types are presented. The contribution shows how novel biomimetic functions can arise from synergisms between specifically designed hybrid materials and the implementation of supramolecular and/or bioorganic concepts.
Electrophilic Amination of Carbanions, Enolates, and Their Surrogates
Authors: Ciganek Engelbert
Published: March 2009

This chapter deals with the formation of carbon‐nitrogen bonds by reaction of carbon nucleophiles with electrophilic aminating reagents. The former encompass aliphatic and aromatic carbanions, enolates and their surrogates such as enamines, enol esters, and enol ethers, as well as carbanions stabilized by cyano or sulfone groups or by phosphorus. A section entitled Reagents and Mechanisms lists the many aminating reagents available and discusses the mechanisms by which the more important ones react. Among the electrophiles discussed are halo amines, various hydroxylamine derivatives, oxaziridines, imines, oximes, diazonium salts, diazo compounds, azo compounds, and azides. The section on Scope and Limitations is organized by carbon nucleophiles and attempts to suggest the best reagents for each class. A number of electrophilic aminating reagents that have been omitted from the scope of this chapter are briefly discussed, with references to reviews, in the section on Comparison with Other Methods. Tables listing references to the preparation of the various aminating reagents are found in the section on Experimental Conditions. References to the conversion of non‐amine products into amines are also provided there. The literature is covered to the middle of 2007.
Desulfonylation Reactions
Authors: Alonso Diego A. , Ájera Carmen N
Published: March 2009

The use of sulfones in organic chemistry, acting as an auxiliary group, is still a very important synthetic strategy, especially for the formation of carbon‐carbon single and double bonds. Once the synthetic objective is achieved, the sulfone gruop is usually removed from the molecule. This removal most commonly involves a reductive desulfonylation process with either replacement of the sulfone by hydrogen, or a process that results in the formation of a carbon‐carbon double bond when a β‐hydroxy or β‐alkoxy sulfone is employed.

This chapter is devoted to the replacement of the sulfone group by a hydrogen (reductive desulfonylation reactions), and reductive elimination reactions of Julia‐type substrates (Julia‐Lythgoe olefination process). The chapter addresses the full scope, generality, limitations, and synthetic applications of these reactions. The literature through most of 2007 is covered.
Portable and Handheld Systems for Energy‐Dispersive X‐ray Fluorescence Analysis
Authors: Cesareo Roberto , Gigante Giovanni E. , Castellano Alfredo , Ridolfi Stefano
Published: March 2009

Energy‐dispersive X‐ray fluorescence (EDXRF) portable spectrometers are becoming very popular in many fields for the on‐site analysis of elements. This is mainly because EDXRF is a nondestructive, multielemental technique that is extremely well suited for the analysis of any material.

An EDXRF spectrometer mainly consists of an X‐ or γ‐ray excitation source, an X‐ray detector with electronics, and a pulse‐height analyzer. Recent technological developments have resulted in small, low‐power, dedicated X‐ray tubes, thermoelectrically cooled semiconductor detectors, and small pulse‐height analyzers. Therefore, completely portable EDXRF spectrometers are available that can be assembled on‐site, having the size of a book and a weight ranging from as light as 500 g (using a radioactive source) to a few kilograms (using an X‐ray tube). These spectrometers can be employed for on‐site analysis in various fields, such as works of art, alloys, soil, environmental samples, forensic medicine, paper, waste materials, mineral ores and their products, or anywhere a portable apparatus would be required.

This article reviews the present status of the development and application of EDXRF portable systems. The various components of a portable system are described: the radiation source, i.e. small, low‐power, dedicated X‐ray tubes or, alternatively, radioactive sources that emit X‐rays or low‐energy γ‐rays; and X‐ray detectors, i.e. proportional gas counters and semiconductor detectors, with special emphasis on the more recent thermoelectrically cooled X‐ray detectors: Si‐PIN (Positive‐Intrinsic‐Negative), Si‐drift, CdTe, CdZnTe, HgI2, and others.

Commercial systems are considered, and finally the most common and significant applications are described, with particular emphasis to the field of works of art.
Actuarial Journals
Authors: Colquitt L. Lee , D'Arcy Stephen P.
Published: March 2009

This article describes broad classifications within the actuarial profession, gives descriptive information about some of the most influential actuarial journals, and discusses the relative influence and accessibility of these journals.
Male–male combats in a polymorphic lizard: residency and size, but not color, affect fighting rules and contest outcome
Authors: Sacchi Roberto , Pupin Fabio , Gentilli Augusto , Rubolini Diego , Scali Stefano , Fasola Mauro , Galeotti Paolo
Published: March 2009

Theoretical models predict that the outcome of dyadic agonistic encounters between males is influenced by resource‐holding potential, resource value, and intrinsic aggressiveness of contestants. Moreover, in territorial disputes residents enjoy a further obvious competitive advantage from the residency itself, owing to the intimate familiarity with their territory. Costs of physical combats are, however, dramatically high in many instances. Thus, signals reliably reflecting fighting ability of the opponents could easily evolve in order to reduce these costs. For example, variation in color morph in polymorphic species has been associated with dominance in several case studies. In this study, we staged asymmetric resident‐intruder encounters in males of the common wall lizard Podarcis muralis, a species showing three discrete morphs (white, yellow, and red) to investigate the effects of asymmetries in color morph, residency, and size between contestants on the outcome of territorial contests. We collected aggression data by presenting each resident male with three intruders of different color morph, in three consecutive tests conducted in different days, and videotaping their interactions. The results showed that simple rules such as residency and body size differences could determine the outcome of agonistic interactions: residents were more aggressive than intruders, and larger males were competitively superior to smaller males. However, we did not find any effect of color on male aggression or fighting success, suggesting that color polymorphism in this species is not a signal of status or fighting ability in intermale conflicts. Aggr. Behav. 35:274–283, 2009. © 2009 Wiley‐Liss, Inc.
Magnetic emulation of microgravity for earth‐bound multiphase catalytic reactor studies—Potentialities and limitations
Authors: Larachi Faïçal , Munteanu Mugurel C.
Published: March 2009

A method is proposed to generate Earth‐bound artificial microgravity in a controlled facility capable of emulating lunar/Martian gravity or microgravity for experiments on passive/reactive catalytic multiphase flows. Its applicability was illustrated for trickle beds where flowing gas and liquid experience artificial microgravity inside the bore of a superconducting magnet generating large gradient magnetic fields to compensate for gravity. Artificial gravity is realized by commuting into apparent gravity acceleration the magnetization force at work on common “chemical engineering” non‐magnetic fluids. The scaling property to be matched and maintained invariant in multiphase systems to achieve magnetic mimicry is phasic mass magnetic susceptibility. Hydrodynamic (liquid holdup, wetting efficiency, pressure drop) as well as catalytic reaction (conversion and selectivity) measurements were obtained. The main finding is a proof that magnetic fields affect reactor outcomes exclusively via hydrodynamic phenomena making them appealing proxies for emulating non‐terrene reactor applications. © 2009 American Institute of Chemical Engineers AIChE J, 2009
Autosomal dominant inheritance in a large family with focal facial dermal dysplasia (Brauer–Setleis syndrome)
Authors: Graul‐Neumann Luitgard M. , Stieler Karola M. , Blume‐Peytavi Ulrike , Tzschach Andreas
Published: March 2009

Focal facial dermal dysplasia (FFDD) (OMIM 227260) is a rare ectodermal disorder characterized by congenital bitemporal scar‐like depressions resembling forceps marks and variable additional facial manifestations. No gene defects or gene loci for FFDD are known to date. We report on a large multi‐generational German family with typical characteristics of FFDD and provide a detailed clinical description of four affected individuals. They had large bitemporal discolored dermal depressions, sparse lateral eyebrows, abnormal eyelashes, and dysplastic and low‐set ears. Three of the four affected individuals had congenital horizontal nystagmus, which had hitherto only been reported in a single patient with FFDD. In contrast to previous assumptions about an autosomal recessive etiology of this disorder, this family provides further evidence that FFDD is inherited in an autosomal dominant mode. Although this family is not large enough to yield significant results in linkage analysis, it may, in combination with other families, contribute to the identification of a gene locus for this intriguing ectodermal disorder. © 2009 Wiley‐Liss, Inc.
Molecular cytogenetic characterization of an interstitial de novo 13q deletion in a 3‐month‐old with severe pediatric gastroesophageal reflux
Authors: Champaigne Neena L. , Laird Nicole A. , Northup Jill K. , Velagaleti Gopalrao V.N.
Published: March 2009

Gastroesophageal reflux (GER) occurs when gastric contents travel back into the esophagus through the esophageal sphincter. GER is very common in infants with most growing out of it, but some continue to have chronic symptoms throughout childhood and adulthood. A gene for severe pediatric gastroesophageal reflux disease (GERD) was identified by linkage analysis and was mapped to chromosome 13. We report here a de novo interstitial deletion of chromosome 13 in a 3‐month‐old biracial male who presented to the emergency room with severe GER and failure to thrive. Chromosome analysis showed an interstitial deletion of chromosome 13, with the karyotype reported as 46, XY, del(13)(q12.3q14.1). BAC‐FISH analysis demonstrated that the deletion encompasses 12.3 Mb and does involve the GERD1 locus. The GERD1 locus has been mapped to a 9‐cM interval between the markers CAGR1 and D13S263, both of which are deleted in our patient. We propose that the GER phenotype in our patient is due to a haploinsufficiency of GERD1. © 2009 Wiley‐Liss, Inc.
The missense mutation G12D in connexin30.3 can cause both erythrokeratodermia variabilis of Mendes da Costa and progressive symmetric erythrokeratodermia of Gottron
Authors: van Steensel M.A.M. , Oranje A.P. , van der Schroeff J.G. , Wagner A. , van Geel M.
Published: March 2009

Progressive symmetric erythrokeratoderma of Gottron (PSEK) is commonly distinguished from erythrokeratodermia variabilis Mendes da Costa (EKV). However, conclusive proof that the disorders are identical is still lacking. We performed mutation analysis and microsatellite haplotyping in two independently referred patients with PSEK and three patients from a previously published family with EKV. All patients had the same mutation in the GJB4 gene causing the amino acid substitution p.Gly12Asp (G12D). Haplotype analysis showed that all five patients had the same allelic haplotype over 2 Mb covering the disease locus. Apparently, the same GJB4 mutation may cause either an EKV or a PSEK phenotype. A single ancestral founder might have introduced EKV in the Netherlands. © 2009 Wiley‐Liss, Inc.
Fluid flow in an impacting symmetrical tee junction III: three‐phase air/water/oil flow
Authors: Doherty A. P. , Murphy A. , Spedding P. L.
Published: March 2009

Results are presented on three‐phase air/oil/water horizontal flow in a 0.026 m i.d. symmetrical impacting tee junction. The flow regimes observed agreed with an existing three‐phase flow map. The inversion from water‐dominated (WD) to oil‐dominated (OD) flow was at an oil‐to‐liquid volumetric ratio of fo = 0.285. The inversion was at a low fo value because of the relatively tranquil conditions studied. Retention of oil on the pipe wall at the air/water two‐phase condition at fo = 0 resulted in a dramatic increase in the pressure drop above that expected for the two‐phase flow. The pressure drop in the tee junction arms increased with liquid‐flow rate. The actual tee junction pressure drop showed a similar pattern to that observed in the inlet arm. The pressure drop was relatively constant in the OD region but showed a dramatic increase in the WD and inversion regions at low fo values. Non‐dimensionalising the junction pressure drop as le/d gave a similar pattern but the scatter of data increased.

The tee pressure loss data were modelled using the Lockhart‐Martinelli ΦG parameter and gave similar but different correlations for the WD and OD regions. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd.
High‐temperature sequestration of elemental mercury by noncarbon based sorbents
Authors: Lee Sung Jun , Wendt Jost O. L. , Biermann Joep
Published: March 2009

This work is concerned with sequestration of elemental Hg at high temperatures (900–1100 °C) on a sorbent that is mineral based, rather than carbon based. This sorbent consists of an intimate mixture of CaO, CaCO3, and Al2O3–2SiO2, and is manufactured in industrially relevant quantities (metric tons) from residues produced in paper recycling processes. In contrast to activated carbon (AC), this noncarbon based sorbent has special advantages in that, it can actually enhance fly ash utilization for cement manufacture, rather than diminish it, as is the case for AC.

Disperse phase experiments have been conducted, using an externally heated quartz tube reactor, with sorbent feeding rates ranging from 1 to 6 g/h. Preliminary results indicate that Hg removal efficiency is sensitive to sorbent feed rates and to furnace temperature. The Hg removal percentage increased with both these variables. Two mechanisms come into play: an in‐flight Hg sorption mechanism, and an Hg sorption mechanism related to sorbent deposits on the reactor wall. A maximum total (in‐flight plus deposit‐related) Hg removal efficiency of 83–90% was obtained at temperatures of 900–1100 °C. There was negligible sorption by either mechanism at temperatures below 600 °C. Results for the in‐flight mechanism alone showed a maximum sorption efficiency at ∼900 °C, whereas that on the reactor surface increased monotonically with temperature. This suggests that sorbent deactivation can occur in‐flight at high temperatures, which is in agreement with other fixed bed results obtained in this laboratory. Deactivation was not apparent for the sorbent‐related substance formed on the reactor wall. Raw and spent sorbents were analyzed by X‐ray diffraction (XRD) and scanning electron microscopy with energy dispersive spectrophotometer (SEM‐EDS) to identify the sorbent mineral transitions that seem to activate the process. The in‐flight mechanisms appear to involve (1) activation of the sorbent, caused most probably by an internal solid–solid reaction, followed by (2) Hg sorption, and (3) possible deactivation, if the temperatures are too high for longer period. Reactor surface mechanisms still remain to be elucidated. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd.
Simultaneous continuous, nonchromatographic monitoring and discrete chromatographic monitoring of polymerization reactions
Authors: Alb Alina M. , Drenski Michael F. , Reed Wayne F.
Published: March 2009

Automatic continuous nonchromatographic monitoring and discrete chromatographic monitoring were coupled together for the first time and used to monitor free radical and controlled‐radical polymerization reactions. This was achieved by adding a multidetector Size Exclusion Chromatography (SEC) system (alternatively termed Gel Permeation Chromatography, GPC) to the ACOMP platform (Automatic Continuous Online Monitoring of Polymerization reactions). The fact that the reactor solution is already preconditioned in the ACOMP front‐end to the concentration levels used in SEC makes direct coupling possible. Kinetics from two different types of reactions, Reversible Addition Fragmentation Transfer (RAFT) and free radical polymerization of butyl acrylate were studied, including the production of a bimodal population. Complementary and contrasting features from the continuous and SEC approaches are highlighted. The main advantage of the SEC detection is to follow the evolution of full molecular weight distributions (MWD), especially in ‘living’ type reactions, where polydispersity decreases with monomer conversion, whereas the continuous detection provides a much more detailed characterization of the reaction. Interestingly, in the case where a bimodal molecular weight distribution was produced, the continuous method automatically detected the onset of the second mode in a model independent fashion, whereas SEC could only discern the bimodality by applying preconceived models. The SEC approach will have valuable niche applications, however, such as when reactions are relatively slow, monitoring narrow polydispersity is of primary importance, and also in copolymerization and terpolymerization reactions where complex mixtures of reagents (e.g., RAFT agents, copper ions, etc.) make unfractionated spectroscopic resolution of comonomers difficult. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009