bluuebunny/crossref_metadata_2025 huggingface dataset:
Electrical Transport Phenomena in Systems of Semiconductor Quantum Dots
Authors: Balberg Isaac
Published: March 2008

While a fairly good understanding of optical and transport properties that are associated with single quantum dots has emerged in recent years the understanding of the relation between these properties and the observed macroscopic optical and electrical properties of solid ensembles
of such dots is still at a very rudimentary level. This is in particular so in regard to the transport properties where the interplay between inter-dot conduction and the connectivity of the dots network determines the macroscopic observations. Reviewing the basic concepts and issues associated
with these two essential ingredients, and considering some recent experimental observations on quantum dot ensembles of CdSe and Si, an effort is made here to derive a whole-but-simple physical basis for the understanding of the transport and the optoelectronic properties of solid state ensemble
of semiconductor quantum dots.
Reconstructed Structures of Nanosized Co Islands on Ag/Ge(111) √3 × √3 Surfaces
Authors: Fu Tsu-Yi , Tsay Sung-Lin , Lin Chun-Liang
Published: March 2008

Structural evolution of Co/Ag/Ge(111) at high temperatures was studied by using scanning tunneling microscopy and low energy electron diffraction. The √3 × √3-Ag layer between the substrate Ge(111) and Co adatoms can avoid the formation of Co–Ge compounds below
800 K. The Co atoms nucleate to form islands where √13 × √13 or 2 × 2 reconstructions were observed after annealing between 373 K and 737 K. The √13 × √13 structure with mirror symmetry relative to [−211], [11-2], and [1-21] axes was observed
for 1–2 layer Co islands. Co islands with over 2 layers appear 2 × 2 structure. All reconstruction structures of the nano-sized Co islands and substrate Ag/Ge(111) √3 × √3 surface were analyzed using the atomic hard sphere model. The bright protrusions of these
reconstructions all sit in the centers of Ag or Ge trimers, which were predicted to have maximum binding energy.
Coating of LaCoO3 Thin Film with Sol–Gel Dip Coating Method
Authors: Okuyucu Hasan , Dahl Paul Inge , Einarsrud Mari Ann
Published: March 2008

LaCoO3 thin film was coated on Al2O3 single crystal by sol–gel route. Appropriate composition of precursors, chelating agents and the solvent put together into a flask and magnetically stirred on a magnetic stirrer. After having the red transparent
solution, it was stirred for 12 hours before coating. Ultrasonically cleaned substrate is dipped into the solution and taken immediately into vertical furnace which is preheated at 550 °C. A dense amorphous film is coated on the substrate. Fired amorphous films are annealed at temperature
between 900 °C and 1000 °C for 20 minutes in the air. Then coated film was characterized by means of XRD, AFM, and SEM. Conductivity of the film was measured to be −0.1819 for 881 °C for the log σ value by assuming the thickness as 1 μm.
Effect of Ion Doping with Donor and Acceptor Impurities on Intensity and Lifetime of Photoluminescence from SiO2 Films with Silicon Quantum Dots
Authors: Mikhaylov A. N. , Tetelbaum D. I. , Burdov V. A. , Gorshkov O. N. , Belov A. I. , Kambarov D. A. , Belyakov V. A. , Vasiliev V. K. , Kovalev A. I. , Gaponova D. M.
Published: March 2008

Doping with donor and acceptor impurities is an effective way to control light emission originated from quantum-size effect in Si nanocrystals. Combined measurements of photoluminescence intensity and kinetics give valuable information on mechanisms of the doping influence. Phosphorus,
boron, and nitrogen were introduced by ion implantation into Si+-implanted thermal SiO2 films either before or after synthesis of Si nanocrystals performed at Si excess of about 10 at.% and annealing temperatures of 1000 and 1100 °C. After the implantation of the
impurity ions the samples were finally annealed at 1000 °C. It is found that, independently of ion kind, the ion irradiation (the first stage of the doping process) completely quenches the photoluminescence related to Si nanocrystals (peak at around 750 nm) and modifies visible luminescence
of oxygen-deficient centers in the oxide matrix. The doping with phosphorus increases significantly intensity of the 750 nm photoluminescence excited by a pulse 337 nm laser for the annealing temperature of 1000 °C, while introduction of boron and nitrogen atoms reduces this emission for
all the regimes used. In general, the effective lifetimes (ranging from 4 to 40 μs) of the 750 nm photoluminescence correlate with the photoluminescence intensity. Several factors such as radiation damage, influence of impurities on the nanocrystals formation, carrier-impurity interaction
are discussed. The photoluminescence decay is dominated by the non-radiative processes due to formation or passivation of dangling bonds, whereas the intensity of photoluminescence (for excitation pulses much shorter than the photoluminescence decay) is mainly determined by the radiative lifetime.
The influence of phosphorus doping on radiative recombination in Si quantum dots is analyzed theoretically.
Direct Observation of Polarons in Electron Populated Quantum Dots by Resonant Raman Scattering
Authors: Aslan B. , Liu H. C. , Korkusinski M. , Hawrylak P. , Lockwood D. J.
Published: March 2008

The general problem of the pairing of strongly interacting elementary excitations producing new quasiparticles such as polarons arises in many areas of solid state physics. Recent interest in polaron formation in semiconductor quantum dots has been motivated by the need to understand
the physical nature of the carrier relaxation processes and their role in quantum-dot based devices. We report on the direct observation of polarons in InAs/GaAs self-assembled quantum dots populated by few electrons where the polarons are strongly coupled modes of quantum dot phonons and
electron intersublevel transitions. The degree of coupling is varied in a systematic way in a set of samples having electron intersublevel spacing changing from larger to smaller than the longitudinal optical phonon energy. The signature of polarons is evidenced clearly by the observation
of a large (12–20 meV) anticrossing for both InAs and GaAs-like quantum dot phonons using resonant Raman spectroscopy.
Peculiarities of Both Light and β-Particles Scattering by Ultrathin Diamond-Like Semiconductor Film
Authors: Rumyantsev Vladimir V. , Shtaerman Esfir Ya.
Published: March 2008

Peculiarities of scattering of TM-polarized light wave by a diamond-like crystalline nano-layer are studied. They are due to specific dispersion of n-phonon polaritons localized in the layer. The IR polaritons discussed here (relating to diamond and Si crystals which are nonpolar
materials) will only appear if some of the vibration modes become polar, e.g., due to the presence of the surface. As a result of mixing of g- and u-modes of ion oscillations along the 〈111〉-direction in the near-surface layer, it is possible to observe additional (with
respect to bulk) scattering of coherent electromagnetic waves of the Stokes and anti- Stokes frequencies. β-particles can be utilized as an independent tool of study of new semiconductors, in particular thin diamond films. The effect associated with response of a quasi-two-dimensional
diamond-like layer to the moving electron field is considered. β-particle field induces phonon excitation modes to arise in the material. Coupled with the β-particle electromagnetic modes they generate polaritons. Spectral density of the radiation intensity of the flashed
phonon polaritons has been estimated as a function of the layer thickness as well as of the scattering angle and the β-particle velocity.
Self-Organization of CrSi2 Nanoislands on Si(111) and Growth of Monocrystalline Silicon with Buried Multilayers of CrSi2 Nanocrystallites
Authors: Galkin Nickolay G. , Goroshko Dmitrii L. , Dotsenko Sergey A. , Turchin Taras V.
Published: March 2008

The process of self-organization of CrSi2 nanosize islands on Si(111)7×7 surface has been investigated during reactive deposition (RDE) of Cr at 500 °C by methods of low energy diffraction (LEED) and differential reflectance spectroscopy (DRS). Morphology of grown
samples has been studied by atomic force microscopy (AFM). DRS data have demonstrated the semiconductor nature of silicide islands from the beginning of Cr deposition at 500 °C. The optimal temperature (750 °C) and optimal Si thickness (50 nm) have been determined for silicon molecular
epitaxy (MBE) growth atop CrSi2 nanosize islands. Monolithic silicon–silicide heterostructures with multilayers of CrSi2 nanosize crystallites have been grown.
Hybrid Nanocomposites Based on Luminescent Colloidal Nanocrystals in Poly(methyl methacrylate): Spectroscopical and Morphological Studies
Authors: Tamborra M. , Striccoli M. , Curri M. L. , Agostiano A.
Published: March 2008

We report on preparation process and optical characterization of a nanocomposite material obtained dispersing colloidal semiconductor nanocrystals (NCs), namely CdS and CdSe@ZnS core–shell system in poly(methyl methacrylate) (PMMA). Such method allows a large flexibility
on nanocrystal materials and on the choice of the polymer characteristics. Nanocomposite thin films were extensively investigated by means optical and morphological techniques. The effects on NC composition, concentration, size, and surface chemistry on the spectroscopical and structural behaviour
of the nanocomposite properties were studied. The NC size dependent optical properties of the nanocomposites are mainly accounted by the NC composition and size, while the morphology of the films is explained on the base of the NC surface characteristics and their concentration in the nanocomposites.
Atomistic Structure Simulation of Silicon Nanocrystals Driven with Suboxide Penalty Energies
Authors: YıImaz D. E. , Bulutay C. , Çagın T.
Published: March 2008

The structural control of silicon nanocrystals embedded in amorphous oxide is currently an important technological problem. In this work, an approach is presented to simulate the structural behavior of silicon nanocrystals embedded in amorphous oxide matrix based on simple valence force
fields as described by Keating-type potentials. After generating an amorphous silicon-rich-oxide, its evolution towards an embedded nanocrystal is driven by the oxygen diffusion process implemented in the form of a Metropolis algorithm based on the suboxide penalty energies. However, it is
observed that such an approach cannot satisfactorily reproduce the shape of annealed nanocrystals. As a remedy, the asphericity and surface-to-volume minimization constraints are imposed. With the aid of such a multilevel approach, realistic-sized silicon nanocrystals can be simulated. Prediction
for the nanocrystal size at a chosen oxygen molar fraction matches reasonably well with the experimental data when the interface region is also accounted. The necessity for additional shape constraints suggests the use of more involved force fields including long-range forces as well as accommodating
different chemical environments such as the double bonds.
Electrical and Memory Properties of Si3N4 MIS Structures with Embedded Si Nanocrystals
Authors: Horváth Zs. J. , Basa P. , Jászi T. , Pap A. E. , Dobos L. , Pécz B. , Tóth L. , Szöllősi P. , Nagy K.
Published: March 2008

Memory structures with an embedded sheet of separated Si nanocrystals were prepared by low pressure chemical vapour deposition using a Si3N4 control layer and different SiO2 or Si3N4 tunnel layers. It was obtained that Si nanocrystals
improve the charging behaviour of the MNOS structures. Memory window width of 1.3 Vand 2.0 V were obtained for pulse amplitudes of ±9 V and ±10 V, 100 ms, respectively. The extrapolated memory window after 10 years is about 15% of its initial value.
Nanostructure Assembly of Indium Sulphide Quantum Dots and Their Characterization
Authors: Vigneashwari B. , Ravichandran V. , Parameswaran P. , Dash S. , Tyagi A. K.
Published: March 2008

Nanocrystals (∼5 nm) of the semiconducting wide band gap material β-In2S3 obtained by chemical synthesis through a hydrothermal route were characterized for phase and compositional purity. These nanoparticles exhibited quantum confinement characteristics
as revealed by a blue-shifted optical absorption. These quantum dots of β-In2S3 were electrically driven from a monodisperse colloidal suspension on to conducting glass substrates by Electophoretic Deposition (EPD) technique and nanostructural thin films were
obtained. The crystalline and morphological structures of these deposits were investigated by X-ray diffraction and nanoscopic techniques. We report here that certain interesting nanostructural morphologies were observed in the two-dimensional quantum dot assemblies of β-In2S3.
The effect of the controlling parameters on the cluster growth and deposit integrity was also systematically studied through a series of experiments and the results are reported here.
Modification of Spontaneous Emission of (CdSe)ZnS Nanocrystals Embedded in Nanoimprinted Photonic Crystals
Authors: Reboud V. , Kehagias N. , Zelsmann M. , Striccoli M. , Tamborra M. , Curri M. L. , Agostiano A. , Fink M. , Reuther F. , Gruetzner G. , Torres C. M. Sotomayor
Published: March 2008

Highly luminescent (CdSe)ZnS nanocrystals, with band edge emission in the red region of the visible spectrum, were successfully synthesized and incorporated in a resist, namely mr-NIL 6000. The nanocomposite material was imprinted by using conventional nanoimprint lithography (NIL)
process. We report on the fabrication and characterization of nanoimprinted photonic crystals in this new functional material. Experiments showed good imprint properties of the NC/polymer based material and that the surface nanostructuration improves the light extraction efficiency by over
2 compared to a nanoimprinted unpatterned surface.
Surface Morphology of Al0.3Ga0.7N/Al2O3-High Electron Mobility Transistor Structure
Authors: Çörekçi S. , Usanmaz D. , Tekeli Z. , Çakmak M. , Özçelik S. , Özbay E.
Published: March 2008

We present surface properties of buffer films (AlN and GaN) and Al0.3Ga0.7N/Al2O3-High Electron Mobility Transistor (HEMT) structures with/without AlN interlayer grown on High Temperature (HT)-AlN buffer/Al2O3 substrate
and Al2O3 substrate. We have found that the GaN surface morphology is step-flow in character and the density of dislocations was about 108–109 cm−2. The AFM measurements also exhibited that the presence of atomic steps with
large lateral step dimension and the surface of samples was smooth. The lateral step sizes are in the range of 100–250 nm. The typical rms values of HEMT structures were found as 0.27, 0.30, and 0.70 nm. HT-AlN buffer layer can have a significant impact on the surface morphology of Al0.3Ga0.7N/Al2O3-HEMT
structures.
Tight Binding Modelling of Energy Band Structure in Nitride Heterostructures
Authors: Akıncı Özden , Gürel H. Hakan , Ünlü Hilmi
Published: March 2008

We studied the electronic structure of group III–V nitride ternary/binary heterostructures by using a semi-empirical sp3s* tight binding theory, parametrized to provide accurate description of both valence and conductions bands. It is shown that the
sp3s* basis, along with the second nearest neighbor (2NN) interactions, spin-orbit splitting of cation and anion atoms, and nonlinear composition variations of atomic energy levels and bond length of ternary, is sufficient to describe the electronic structure of
III–V ternary/binary nitride heterostructures. Comparison with experiment shows that tight binding theory provides good description of band structure of III–V nitride semiconductors. The effect of interface strain on valence band offsets in the conventional Al1−xGaxN/GaN
and In1−xGaxN/GaN and dilute GaAs1−xNx/GaAs nitride heterostructures is found to be linear function of composition for the entire composition range (0 ≤ x ≤ 1) because of smaller valence band deformations.
Synthesis of Nanosized ZnO by High Frequency Induction Method
Authors: Chang Ho , Tsai Ming-Hsun
Published: March 2008

In this study, presents an innovative method for nanoparticle synthesis system for nanosized ZnO fabrication with powder or suspension type. The experimental device is primarily composed of a high frequency induction heating system, a pressure control system, a temperature control system
and an automatic nanoparticle collection system. This study employs an automatic collection system with liquid nitrogen to condense and collect the nanoparticles. The influence of such process variables such as heating temperature and vacuum pressure are analyzed and compared through experimentation
in order to identify the working conditions most conducive to the production of nanoparticles with smaller mean particle size. The prepared ZnO nanoparticles are characterized for nanostructural properties by the TEM and XRD. An Ultraviolet–Visible (UV–Vis) spectrophotometer is
used to analyze the optical property of the nanoparticles. The ZnO nanofluid already has good dispersion, so even without dispersant, it can still remain in stable suspension for a fairly long time. Experimental results indicate that the particle size of produced ZnO nanoparticles is around
20 nm and with the production rate of 1.24 g/min.
Thickness Dependence of Magnetic Properties of Co90Fe10 Nanoscale Thin Films
Authors: Yalçin O. , Kazan S. , Şahingöz R. , Yıldız F. , Yerli Y. , Aktaş B.
Published: March 2008

Ferromagnetic monolayers Co90Fe10 thin films with individual layer thicknesses 2, 6, and 8 nm were grown on thermally oxidized Si substrate and magnetic properties of these were investigated with Ferromagnetic resonance (FMR) technique at room temperature. The
magnetoresistance (MR) of the samples were measured as a function of applied DC magnetic field and the thickness dependence of the MR was plotted. The FMR spectra were recorded for both parallel and perpendicular geometry. The X-band (9.5 GHz) FMR spectra and resonance field of samples were
analyzed and fitted theoretically by using the Landau-Lifshits dynamic equation of motion for magnetization with the Bloch-Bloembergen type damping term. The computer programs have been written to extract the effective magnetization (M), g-values and spin–spin relaxation time
(T2) fitting parameters. The thickness dependence of magnetic parameters has been obtained from experimental data by mean of a theoretical model.
Preparation and Characterization of Ni-Nitrilotriacetic Acid Bearing Poly(Methacrylic Acid) Coated Superparamagnetic Magnetite Nanoparticles
Authors: Tural Bilsen , Kaya Murat , Özkan Necati , Volkan Mürvet
Published: March 2008

Stable superparamagnetic magnetite (Fe3O4) nanoparticles were synthesized via co-precipitation in the presence of poly(methacrylic acid) (PMAA) in aqueous solution. The polymer coated Fe3O4 nanoparticles were characterized using transmission
electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction, thermal analysis, and vibrating sample magnetometry (VSM) techniques. These measurements reveal the presence of magnetite nanoparticles with a size of approximately 8 nm inside the PMAA matrix. The
magnetization value of these superpara-magnetic nanoparticles at room temperarure and 7 T was measured as about 40 emu/g. PMAA-coated Fe3O4 nanoparticles were further assembled with Ni-chelate through a reaction between a primary amine-bearing NTA (nitrilotriacetic acid)
ligand and carboxy-functional groups of PMAA. NTA-PMAA-coated magnetite nanoparticles were then loaded with nickel ions and characterized using FTIR. The average amount of binded Ni on the surface of the NTA-modified PMAA coated Fe3O4 was calculated as 1.65 ± 0.3
× 10−6 mol nickel(II) ions per g of the magnetic particles from the inductively coupled plasma optical emission spectroscopy (ICP-OES) measurements.
Size Effects in Ferroelectric PbTiO3 Nanomaterials Observed by Multi-Frequency Electron Paramagnetic Resonance Spectroscopy
Authors: Erdem Emre , Matthes Anke , Böttcher Rolf , Gläsel Hans-Jürgen , Hartmann Eberhard
Published: March 2008

Lead titanate (PbTiO3) micro- and nanocrystalline powders have been prepared from metallo-oranic precursor through combined polymerisation and pyrolysis (CPP). The enhanced liquid-precursor based version of the cpp route in combination with soft milling enables an adjustment
of the mean particle size up to 5 nm. A multi-frequency (X, Q, and W band) electron paramagnetic resonance study of Cr-doped micro- and nanocrystalline PbTiO3 samples was performed. Three Cr3+ centers (C1, C2, and C3) with different axial Zero Field Splitting (ZFS) parameters
were identified in micro-crystalline samples. The center C1 is similar to that observed in previous X band single crystal and ceramic sample measurements. The superposition model by Newman and Urban was applied to translate the ZFS data of these centers into local Cr3+ displacements
inside the distorted oxygen octahedra of the microcrystalline PbTiO3 lattice. In the nanocrystalline powders only the center C1 was observed. Its EPR spectra in dependence on the mean particle size were fitted using a spin-Hamiltonian in which a Gaussian distribution of ZFS terms
was assumed. The variation of the mean value of ZFS parameter D and distribution width ΔD was determined and the critical particle size of the size-driven phase (tetragonal-cubic) transition was estimated. In nanocrystalline powders with mean particle size d <
dcr the tetragonal C1 spectrum is not more detectable. A new Cr3+ center spectrum, C4, consisting of a single line with an isotropic g-factor is detectable allowing the cubic phase in the nanomaterials to be quantified. Further, temperature dependent EPR measurements
were made which allowed the variation in Curie temperature with mean particle size to be determined.
The Influence of Polymer Architecture on Nanosized Hydroxyapatite Precipitation
Authors: Dogan Özlem , Öner Mualla
Published: March 2008

In this work we present a facile way to produce hydroxyapatite (HAP) nanoparticles by wet chemical synthesis in the presence of polyelectrolytes under controlled temperature, pH, and atmospheric conditions. The resulting calcium rich carbonated HAP is sintered in an air atmosphere to
investigate the thermal stability of the synthesized powders. The morphology and microstructure of the HAP nanoparticles were investigated by XRD, SEM, FTIR spectroscopy, thermal analysis, and particle size analyzer. Polyelectrolytes affect the coherent length of the crystalline domain, the
dimension and particle size distribution of the crystals. The reduction in size is greater in the direction of the c-axis. The SEM micrograph shows the formation of well-crystallized, agglomerated small particles of HAP. The mean size of the subunit is smaller than that of the surface
of the grain observed in SEM. X-ray analysis have shown that the resulting particles have high thermal stability.
Impurity-Driven Nanocrystallization of Zr-Based Bulk Amorphous Alloys
Authors: Akdeniz M. Vedat , Mekhrabov Amdulla O.
Published: March 2008

The effect of oxygen content and Ti addition on the glass forming ability (GFA) and crystallization kinetic of Zr-based bulk glass forming alloys have been studied by means of thermal analysis and X-ray diffraction techniques. Presence of oxygen triggers the formation of a nanocrystalline
metastable f.c.c. Zr2 Ni-type phase which can act as heterogenous nucleation sites for the formation of dendrites during solidification. An increase in oxygen content changes the crystallization behaviour from a single- to a double-step process and triggers the crystallization of
stable Zr2(Cu,Al) besides metastable Zr2 Ni-type phase. Oxygen-triggered nucleation of a nanocrystalline metastable Zr2 Ni-type phase is found to be the initial step of crystallization. The important parameters of GFA such as glass transition temperatures,
Tg, the crystallization temperatures, Tx, and crystallization enthalpies, ΔH, were determined by using DSC. It was observed that the presence of oxygen, even in a very small amount, and Ti addition cause a drastic reduction of the supercooled liquid
region, ΔTx, accompanied by a change of the crystallization kinetic. This leads to the decrease in stability of the supercooled liquid, consequently results in a deterioration of the glass forming ability of the alloy.
Functionality of C(4,4) Carbon Nanotube as Molecular Detector
Authors: Malcıoglu Osman Barış , Erkoç Şakir
Published: March 2008

Alterations in the electronic transport properties of C(4,4) single walled carbon nanotube when an agent is introduced to the outer surface are investigated theoretically. Several chemical agents in this context are investigated. The calculations are performed in two steps: First an
optimized geometry for the functionalized carbon nanotube is obtained using semi-empirical calculations at the PM3 level, and then the transport relations are obtained using non equilibrium green-function approach. Gaussian and Transiesta-C simulation packages are used in the calculations
correspondingly. The "electrodes" are chosen to be ideal geometry of the particular carbon nanotube, eliminating current quantization effects due to contact region. By varying chemical potential in the electrode regions, an I–V curve is traced for each particular functionalisation.
Conductance in carbon nanotubes show a strong dependence on the geometry and aromaticity, both are which altered when the suitable agent is introduced. This dependence results in rather dramatic response in the I–V trace, the current is reduced significantly, and quantization
effects are observed, even for a single molecule. However due to chemically stable nature, not all agents form a chemical bond to the surface. Overall, the material is a promising candidate for detector equipment.
Large-Scale, Reliable and Robust SERS-Active Nanowire Substrates Prepared Using Porous Alumina Templates
Authors: Kartopu G. , Es-Souni M. , Sapelkin A. V. , Dunstan D.
Published: March 2008

We have developed new concepts and successfully prepared large area, ordered, and compact nanowire arrays for surface-enhanced Raman scattering applications. These nanowire films were synthesized via electrodeposition using porous alumina templates of varying order, thickness and pore
diameters. Mechanical polishing has been shown to be a very effective method to prepare nanowire arrays with monodisperse length over comprehensively large dimensions. On the other hand, a convenient synthesis route has been suggested that allows the formation of nanoparticle arrays using
very thin and/or large area porous alumina films. It is reckoned that even films with the smallest obtainable pore sizes can be utilized to prepare large area, fine nanoparticle arrays. Such arrays may also find use in other areas, such as solar cells and electrochemistry. Preliminary Raman
experiments indicated that the nanowire/nanoparticle arrays are indeed surface-enhanced Raman scattering-active. Finally, the potentials offered by the reported processing methods for fabricating substrates with predictable and high Raman amplifications are discussed.
An On-Line Measurement and Control System for Submerged Arc Spray Synthesis of TiO2 Nanoparticles
Authors: Chen Liang-Chia , Ji Bao-Hong
Published: March 2008

This article presents the development of an on-line measurement and control system for process characterization and optimization of the nanoparticle manufacturing process, called the submerged arc-spray nanoparticle synthesis system (SANSS). To achieve optimized control of particle
uniformity, this research investigates the feasibility of employing optical fiber probe and the dynamic light scattering (DLS) technique to monitor and control particle sizes. According to the theory of DLS, an on-line nanoparticle sampling and measurement system was developed and integrated
with the SANSS as an important step to verify the measurement performance of the proposed method. To examine the measurement accuracy of the developed system, calibrated polystyrene latex particles with known accurate sizes were employed to verify the particle sizing accuracy of the proposed
system. The data conformity between the measurement results of TiO2 nanoparticles obtained by various methods, including TEM, a calibrated commercial particle sizing system and the on-line measurement system, has indicated that the developed method was feasible and effective.
Anomalous Absorption of Isolated Silver Nanoparticulate Films in Visible Region of Electromagnetic Field
Authors: Kim Sang Woo , Hui Bang Jae , Bae Dong-Sik
Published: March 2008

Anomalous absorption of isolated silver nanoparticulate films with different morphological patterns prepared by the wet colloidal route and followed by thermal treatment were investigated. A polymer embedded silver nanoparticulate film thermally treated at 200 °C showed maximum
absorbance at ∼412 nm. The peakposition of the surface plasmon band was slightly different but still consistent with theoretical prediction derived by the Mie theory. An isolated nanopariculate film thermally treated at 300 °C showed anomalous absorption. Its maximum absorption band
was shifted to green regime of 506.9 nm and the bandwidth at half-maximum absorbance of the surface plasmon band was greatly broadened. The plasmon band and its bandwidth were much deviated compared to the theoretical prediction calculated for the silver nanoparticles in the surrounding medium
of air and poly(vinyl pyrrolidone) or soda-lime-silica glass. Even though there was no significant growth of silver nanoparticles during thermal treatment at 300 °C, the anomalous absorption was observed. The anomalous absorption was not attributed to effects of particle shape and size
but to effects of pores induced by development of a great number of pores in the nanoparticulate film. The anomalous absorption greatly decreased with increase in heating temperature from 400 °C to 500 °C. The extraordinary plasmon damping of the isolated film decreased and the plasmon
absorption band was re-shifted to violet regime of 416 nm because of large decrease in size of particles with dramatic change of pore morphology from circular pores with rim to small continuous pores induced by spontaneous formation of new silver nanoparticles.
Microstructures and Shape Memory Characteristics of a Nanostructured Ti-50.0Ni(at%) Alloy
Authors: Cho Gyu-bong , Kim Yeon-ho , Kim Han-sung , Choi Ju-young , Lee Jung-moo , Nam Tae-hyun
Published: March 2008

Nanostructured Ti-Ni alloys were prepared by cold working followed by annealing, and then their shape memory characteristics and superelasticity were investigated by means of differential scanning calorimetry (DSC), transmission electron microscopy (TEM), thermal cycling tests under
constant load and tensile tests. Morphology of amorphous phases induced by cold working depended largely on the amount of cold working. They had domain like shape in the 40% cold rolled alloy, while had mainly wide band shape in the 70% cold rolled alloy. In 40% cold rolled alloy, the average
grain size increased from 27 nm to 80 nm with increasing annealing temperature from 573 K to 673 K. Transformation elongation increases with raising annealing temperature, which was ascribed to the increase in grain size reducing the constraints of grain boundaries. Transformation hysteresis
increased rapidly with raising annealing temperature up to 623 K, above which they almost keep constant, which was ascribed to the small grain size and large constraints of grain boundaries.
Silver Nanoparticle-Doped Polyvinyl Alcohol Coating as a Mediumfor Surface-Enhanced Raman Scattering Analysis
Authors: Karabıçak Seher , Kaya Murat , Vo-Dinh Tuan , Volkan Mürvet
Published: March 2008

A simple polymer substrate for inducing Surface-Enhanced Raman Scattering (SERS) has been investigated. This SERS substrate consists of a solid support, such as a glass slide covered with polyvinyl alcohol (PVA) impregnated with fine silver nanoparticles. The preparation simply involves
mixing aqueous PVA polymer with solid AgNO3 to produce a solution that can be easily spin coated on the glass substrate and dried to obtain a hard translucent coating. Aqueous solution of FeSO4·7H2O was used to reduce Ag+ ions to silver nanoparticles.
The effects of various experimental conditions of sample preparation were investigated in order to improve the Raman enhancement efficiency of the substrate. The overall substrate performance was evaluated with the use of biologically important compounds: benzoic acid, p-amino benzoic acid,
pyridine and dopamine. The spectral features of these compounds closely matched with those reported in literature. The use of the polymer matrix made the SERS substrate resistant to scratching, therefore, improving it to be more suitable for field applications. The hydrophilic nature of the
polymer provides additional advantages for probing biological samples. The shelf-life of the dried, unreduced substrates is at least one month.
Assessing Static and Dynamic Influences on Inmate Violence Levels
Authors: Steiner Benjamin
Published: March 2008

Inmate misconduct creates problems for other inmates as well as correctional staff. Most empirical assessments of the correlates of inmate misconduct have been conducted at the individual level; however, a facility's level of misconduct may be of equal importance to prison management and state officials because these numbers can reflect order, or lack thereof, within an institution. Prior prison research also has typically been cross-sectional and conducted at one time point. In this study, the relative contributions of facility-and state-level predictors of misconduct, considered elements of the social organization of a prison, are examined across two time points for 512 state-operated prisons housing adult men. Cross-sectional and longitudinal findings reveal that predictors such as the racial composition of the inmates and staff, measures of administrative control, and state-level factors have both static and dynamic effects on levels of violent misconduct.
Trust and Confidence in the Courts
Authors: Sprott Jane B. , Greene Carolyn
Published: March 2008

It is assumed that legitimacy of the legal system is important, yet almost nothing is known about how young offenders view this institution. A sample of youths were interviewed at their first appearance in court and asked about their feelings regarding how they have been treated (procedural justice) by their lawyer, by the crown attorney, and by the judge, as well as their views on the overall legitimacy of the legal system. Youths were again interviewed at sentencing, using the same questionnaire, to explore changes in their views over time. Generally, it appears that how youths feel they have been treated— specifically, by their own lawyer and by the judge—affected broad views of legitimacy, even when controlling for their overall satisfaction of the outcome of their case.
Combating NEED
Authors: Hazirjian Lisa Gayle
Published: March 2008

This article examines the struggle for control over Rocky Mount's Community Action Program (CAP)— Nash-Edgecombe Economic Development (NEED)—as a turning point in a longstanding urban conflict. For decades, white businessmen and government officials had repeatedly blocked African Americans from using federal policy innovations to promote racial equality and black economic advancement. Implementation of the city's War on Poverty initially followed these well-established patterns. But by the summer of 1967, working-class African American neighborhood organizations, supported by federal and state agencies, loosened the white political establishment's grip on NEED, secured improvements in rental housing regulation, and increased their role within the city's evolving black freedom movement. In exploring these transformations, this essay argues that the CAP should be reevaluated from the perspective of how it altered the course of local economic and political struggles, and how local contests over implementation of the CAP reshaped the War on Poverty.
Writing Watts
Authors: Widener Daniel
Published: March 2008

The Watts Writers Workshop was among the most visible community arts projects to develop in Southern California after the 1965 Watts riot. The brainchild of author, screenwriter, and Hollywood personality Budd Schulberg, the workshop sought to develop creative writing talent as an antidote for black social alienation. As an effort in interracial urban reform through artistic expression, the workshop found strong initial support among liberal celebrities, government officials, and private foundations. The increasing salience of the black power movement, however, raised serious internal questions regarding the workshop's avowedly integrationist mission. The Watts Writers Workshop thus offers an important window into the 1960s-era conflict between liberal and radical forces.
Redefining the Axis of Beijing
Authors: Shuishan Yu
Published: March 2008

This article analyzes the urban planning controversies that led to the fast expansion of Chang'an Avenue and the irreversible alteration of Beijing's urban fabric, focusing on the issue of Beijing city's dominant axis in the Liang-Chen Scheme and Zhu-Zhao Scheme around the year 1950. My argument is that the failure of Liang's vision for Beijing was mainly due to the nostalgic nature of his proposal and its close affiliation with the imperial model, which did not meet the expectation of the revolutionary spirit of the time. Politics did play a central role in the urban transformation of Beijing in the People's Republic of China. However, instead of treating architects' debate as a footnote to Mao's casual comments, this article integrates the Chinese Communist Party's political agenda as part of the architectural discourse.
The 1994 Tax Reform and Its Impact on China's Rural Fiscal Structure
Authors: An Chen
Published: March 2008

This article analyzes the fiscal crisis at the township level and the related worsening of the peasant burden that was predominantly caused by the 1994 tax reform. This reform changed the tax-sharing rules in favor of the central government. The pressure for performance under tighter fiscal constraints drove local officials to replicate the central government's "self-serving" policy and to desperately attempt to balance their budgets at the cost of their subordinate jurisdictions. Located at the bottom of the administrative hierarchy, the township had no subordinate governments to absorb its fiscal losses or contribute to its coffers. Diminished sources of revenue compelled township officials to squeeze the peasants even harder, particularly in the agricultural provinces. While the tax-for-fee reform and the repeal of the agricultural tax eliminated most of the burden on the peasants, the fundamental structural problem with rural finance not only still exists but also is getting worse.
Creating Your Own Hostile Environment: A Laboratory Examination of Trait Aggressiveness and the Violence Escalation Cycle
Authors: Anderson Craig A. , Buckley Katherine E. , Carnagey Nicholas L.
Published: March 2008

A dyadic interactive aggression paradigm tested hypotheses from the General Aggression Model about how trait aggressiveness can create behaviorally hostile social environments. Pairs of college student participants competed in a modified reaction time task in which they repeatedly delivered and received each other's punishments. The trait aggressiveness of both participants influenced the punishment intensities (aggression level) set by each member of the dyad on later trials. Furthermore, there was a pattern of escalation from early to later trials. These trait aggressiveness effects (both self and partner) on later aggressive behavior were largely mediated by partner aggression levels during early trials. Results also suggested two aggressive motives—hostile and instrumental—resulted from high partner aggression during early trials and these motives partially mediated the effects of trait aggressiveness and of early trial aggression on later aggressive behavior.
Gender Differences in Interpersonal Complementarity Within Roommate Dyads
Authors: Ansell Emily B. , Kurtz John E. , Markey Patrick M.
Published: March 2008

Complementarity theory proposes specific hypotheses regarding interpersonal styles that will result in successful relationships. The present study sought to extend previous research on gender differences in complementarity through the examination of same-sex peer dyads and the use of informant reports of interpersonal style. One hundred twenty participants (30 male and 30 female roommate dyads) completed interpersonal circumplex ratings of their roommates and a relationship cohesion measure. Examinations of complementarity indicate that women reported significantly more complementarity than men within their roommate dyads. However, for men and women, the closer the dyad was to perfect complementarity in terms of dominance, the more cohesive the relationship. Results are discussed in relation to gender differences in social development.
Reciprocal Effects Between Academic Self-Concept, Self-Esteem, Achievement, and Attainment Over Seven Adolescent Years: Unidimensional and Multidimensional Perspectives of Self-Concept
Authors: Marsh Herbert W. , O'Mara Alison
Published: March 2008

In their influential review, Baumeister, Campbell, Krueger, and Vohs (2003) concluded that self-esteem— the global component of self-concept—has no effect on subsequent academic performance. In contrast, Marsh and Craven's (2006) review of reciprocal effects models from an explicitly multidimensional perspective demonstrated that academic self-concept and achievement are both a cause and an effect of each other. Ironically, both reviews cited classic Youth in Transition studies in support of their respective claims. In definitive tests of these counter claims, the authors reanalyze these data—including self-esteem (emphasized by Baumeister et al.), academic self-concept (emphasized by Marsh & Craven), and postsecondary educational attainment—using stronger statistical methods based on five waves of data (grade 10 through 5 years after graduation; N = 2,213). Integrating apparently discrepant findings under a common theoretical framework based on a multidimensional perspective, academic self-concept had consistent reciprocal effects with both achievement and educational attainment, whereas self-esteem had almost none.
Justice for Whom, Exactly? Beliefs in Justice for the Self and Various Others
Authors: Sutton Robbie M. , Douglas Karen M. , Wilkin Katie , Elder Tracey J. , Cole Jennifer M. , Stathi Sofia
Published: March 2008

The present studies examine why people think the world is more just to themselves than to others generally. Beliefs in justice for the self were uniquely associated with psychological adjustment, consistent with the theoretical motive to believe in justice for the self (Studies 1 and 2). However, this “justice motive” did not appear to affect the relative strength of justice beliefs. Instead, self–other differences in justice beliefs appeared to reflect objective assessments of the justice received by various demographics. Undergraduates believed the world to be more just to themselves than to others but not their undergraduate peers specifically (Study 1). Participants of both genders believed the world to be more just to men, and to themselves, than to women (Study 2). Women did not exempt themselves individually from injustice but believed, similar to men, that undergraduate women receive as much justice as men (Study 3).
Attitudinal Ambivalence and Message-Based Persuasion: Motivated Processing of Proattitudinal Information and Avoidance of Counterattitudinal Information
Authors: Clark Jason K. , Wegener Duane T. , Fabrigar Leandre R.
Published: March 2008

Attitudinal ambivalence has been found to increase processing of attitude-relevant information. In this research, the authors suggest that ambivalence can also create the opposite effect: avoidance of thinking about persuasive messages. If processing is intended to reduce experienced ambivalence, then ambivalent people should increase processing of information perceived as proattitudinal (agreeable) and able to decrease ambivalence. However, ambivalence should also lead people to avoid processing of counterattitudinal (disagreeable) information that threatens to increase ambivalence. Three studies provide evidence consistent with this proposal. When participants were relatively ambivalent, they processed messages to a greater extent when the messages were proattitudinal rather than counterattitudinal. However, when participants were relatively unambivalent, they processed messages more when the messages were counterattitudinal rather than proattitudinal. In addition, ambivalent participants perceived proattitudinal messages as more likely than counterattitudinal messages to reduce ambivalence, and these perceptions accounted for message position effects on amount of processing.
On Being ‘Frank’ about Terrorism
Authors: Oliverio Annamarie
Published: March 2008

Andre Gunder Frank's work on the global economy, social movements and his own experiences reflect critical issues related to the state and terror. He understood all too well the insidious, yet symbiotic relationship between the state and terror. Frank views politics and terror as a manipulation, a corrupt act of states, powerful elites, groups and organizations that have the resources to enforce their version of political and social reality. Similar to former US President Eisenhower, Frank bemoaned the power of the military post-industrial complex for its organized and systematic capability to legitimize and institutionalize terrorism. Frank was sensitive to how certain acts by states, typically referred to as counter-terrorism, enable them to shape the political agenda not only within countries but also in international affairs. Perhaps a more fruitful path of action, as implied by Frank's research and by the ‘blowback’ consequences of the state of terror, is to work on changing the social, economic and political conditions that give rise to the use of terror as a strategy by states or challenge groups.
World System History, The Papacy, and the Transition from Transitions
Authors: Denemark Robert A.
Published: March 2008

In a very controversial argument, Andre Gunder Frank suggested that scholars abandon ideas like ‘transitions’ and ‘modes of production’ in favor of more accurate, less Eurocentric concepts. This work reviews three relevant debates on the use of these concepts. The class backgrounds of 64 popes from 1300 to 1900 are then analyzed to see if leaders of a powerful, non-hereditary office altered over that time. The analysis offers no support regarding the role of transitions or modes of production in helping to understand elite recruitment. This finding supports Frank's suggestion that we consider alternative conceptual foundations for understanding development.
Q-Methodology in Nursing Research
Authors: Akhtar-Danesh Noori , Baumann Andrea , Cordingley Lis
Published: March 2008

This article provides an overview and application of Q-methodology for nursing researchers, with an illustration of its appropriate usage. Q-methodology has been identified as a method for the analysis of subjective viewpoints and has the strengths of both qualitative and quantitative methods. It shares with qualitative methodologies the aim of exploring subjectivity; however, statistical techniques are used to reveal the structure of views. This article describes the use of Q-methodology to examine subjectivity systematically, revealing connections between accounts that other techniques may overlook. An example from the literature is presented. Q-methodology is useful in qualitative nursing research concerned with the exploration and comparison of subjectivity and attitudes. It can be used to effectively identify attitudes, perceptions, feelings, and values as well as explore life experiences such as stress, self-esteem, body image, and satisfaction.