bluuebunny/crossref_metadata_2025 huggingface dataset:
Current State of the Law of International Watercourses: Progress and Paradigm Shifts 1815–2008
Authors: Malla Katak
Published: November 2008

This article focuses on the current state of the law of international watercourses. Progress and management paradigm shifts of the regime of uses and environmental protection of the international watercourses (1815–2008) are examined through the main sources of international law. Current state of the law is demonstrated by analysing the transition of the various concepts and approaches (i.e. international river to international basin), substantive principles (i.e. absolute sovereignty to equitable utilisation), implementation mechanisms (i.e. piecemeal to integrated management) and dispute settlement venues (i.e. adjudication to impartial fact-finding). The present state of the law recognises developmental needs and environmental considerations as equal, establishing parity between the regimes of uses and environmental protection. The findings can be helpful to determine how the law of international watercourses, particularly relevant treaties, has to be aligned with sustainable developments, elaborating the prospects for an integrated legal perspective, combating the adverse impacts of the global hydro-climate change.
Minority Rights, Democracy and Development: The African Experience
Authors: Appiagyei-Atua Kwadwo
Published: November 2008

The article contends that in spite of recent attempts to marry human rights to development, the marriage remains one of convenience, and to the inconvenience of disadvantaged groups, particularly indigenous peoples who are the focus of discussion. The author further contends that contrary to the claim that the relationship between rights and development were non-existent to begin with, there was such recognition. In the context of promoting effective minority rights which lies at the heart of peace and stability in Africa, a re-visioning of the relationship between rights, democracy and development in Africa is suggested which challenges the current notions of “market democracy,” “good governance” and “liberal international orthodoxy”. The analysis tackles ways in which effective promotion of minority rights can be realised, based on a cultural relativist perspective. The paper finally proposes the creation of a distinct Protocol or Charter on Minority Peoples in Africa to better serve their peculiar needs and interests.
Self-Assembly and Graft Polymerization Route to Monodispersed Fe3O4@SiO2—Polyaniline Core–Shell Composite Nanoparticles: Physical Properties
Authors: Reddy Kakarla Raghava , Lee Kwang-Pill , Kim Ju Young , Lee Youngil
Published: November 2008

This study describes the synthesis of monodispersed core–shell composites of silica-modified magnetic nanoparticles and conducting polyaniline by self-assembly and graft polymerization. Magnetic ferrite nanoparticles (Fe3O4) were prepared by coprecipitation
of Fe+2 and Fe+3 ions in alkaline solution, and then silananized. The silanation of magnetic particles (Fe3O4@SiO2) was carried out using 3-bromopropyltrichlorosilane (BPTS) as the coupling agent. FT-IR spectra indicated the presence
of Fe—O—Si chemical bonds in Fe3O4@SiO2. Core–shell type nanocomposites (Fe3O4@SiO2/PANI) were prepared by grafting polyaniline (PANI) on the surface of silanized magnetic particles through surface
initiated in-situ chemical oxidative graft polymerization. The nanocomposites were characterized by high resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), X-ray photoelectron spectra (XPS), Fourier transform infrared (FTIR) spectra, UV-visible spectroscopy,
photoluminescence (PL) spectra, electrical conductivity and magnetic characteristics. HRTEM images of the nanocomposites revealed that the silica-modified magnetic particles made up the core while PANI made up the shell. The XPS spectrum revealed the presence of silica in the composites, and
the XRD results showed that the composites were more crystalline than pure PANI. PL spectra show that composites exhibit photoluminescent property. Conductivity of the composites (6.2 to 9.4 × 10−2 S/cm) was higher than that of pristine PANI (3.7 × 10−3
S/cm). The nanocomposites exhibited superparamagnetism. Formation mechanism of the core–shell structured nanocomposites and the effect of modified magnetic nanoparticles on the electro-magnetic properties of the Fe3O4@SiO2/PANI nanocomposites are
also investigated. This method provides a new strategy for the generation of multi-functional nanocomposites that composed of other conducting polymers and metal nanoparticles.
Fabrication of Gold Nanotubes from Removable MgO Nanowires Templates
Authors: Kim Hyoun Woo , Lee Jong Woo , Kebede Mesfin A. , Kim Hyo Sung , Srinivasa Buddhudu , Kong Myung Ho , Lee Chongmu
Published: November 2008

We have prepared MgO/Au core–shell nanowires, subsequently demonstrating the fabrication of Au nanotubes by using MgO nanowires as a sacrificial template. The samples were characterized by scanning electron microscopy, X-ray diffraction, transmission electron microscopy, and energy-dispersive
X-ray spectroscopy. MgO nanowires were coated with a conformal layer of Au via sputtering. By etching away the MgO core in aqueous (NH3)2SO4 solution, hollow nanotube-like structures of Au were readily obtained. This approach offers a potentially useful route
for the fabrication of a variety of hollow metallic structures.
Zirconia Coating of Carbon Nanotubes by a Hydrothermal Method
Authors: Garmendia N. , Bilbao L. , Muñoz R. , Imbuluzqueta G. , García A. , Bustero I. , Calvo-Barrio L. , Arbiol J. , Obieta I.
Published: November 2008

Carbon nanotubes have unique mechanical properties that open attractive possibilities in many fields, such as the biomedical one. Currently, zirconia ceramics are widely used as femoral heads, but case studies show that delayed failure can occur in vivo due to crack propagation.
Nanotubes could avoid the slow crack propagation and enhance the toughness of the ceramic material used for prostheses fabrication. In this work, single-wall carbon nanotubes and multi-wall carbon nanotubes have been partially coated with nanozirconia via hydrothermal synthesis and characterized
by several techniques: X-ray diffraction, infrared spectroscopy, scanning electron microscope, transmission electron microscope, electron energy loss spectra, X-ray photoelectronic spectroscopy and atomic force microscopy. By means of these techniques, the existence of bonds between zirconium
and the carbon nanotube has been proved. The as covered nanotubes should offer a better wettability in the ceramic matrix and improve the dispersion of the carbon nanotubes, to obtain the desired new ceramic biomaterial with a longer lifetime and better reliability.
Molten Salt Synthesis of Nanocrystalline Phase of High Dielectric Constant Material CaCu3Ti4O12
Authors: Prakash B. Shri , Varma K. B. R.
Published: November 2008

Nanocrystalline powders of giant dielectric constant material, CaCu3Ti4O12 (CCTO), have been prepared successfully by the molten salt synthesis (MSS) using KCl at 750 °C/10 h, which is significantly lower than the calcination temperature (∼1000
°C) that is employed to obtain phase pure CCTO in the conventional solid-state reaction route. The water washed molten salt synthesized powder, characterized by X-ray powder diffraction (XRD), Scanning electron microscopy (SEM), and Transmission electron microscopy (TEM) confirmed to be
a phase pure CCTO associated with ∼150 nm sized crystallites of nearly spherical shape. The decrease in the formation temperature/duration of CCTO in MSS method was attributed to an increase in the diffusion rate or a decrease in the diffusion length of reacting ions in the molten salt
medium. As a consequence of liquid phase sintering, pellets of as-synthesized KCl containing CCTO powder exhibited higher sinterability and grain size than that of KCl free CCTO samples prepared by both MSS method and conventional solid-state reaction route. The grain size and the dielectric
constant of KCl containing CCTO ceramics increased with increasing sintering temperature (900 °C–1050 °C). Indeed the dielectric constants of these ceramics were higher than that of KCl free CCTO samples prepared by both MSS method and those obtained via the solid-state reaction
route and sintered at the same temperature. Internal barrier layer capacitance (IBLC) model was invoked to correlate the observed dielectric constant with the grain size in these samples.
Control of Single-Electron Charging of Metallic Nanoparticles onto Amorphous Silicon Surface
Authors: Weis Martin , Gmucová Katarína , Nádaždy Vojtech , Capek Ignác , Šatka Alexander , Kopáni Martin , Cirák Július , Majková Eva
Published: November 2008

Sequential single-electron charging of iron oxide nanoparticles encapsulated in oleic acid/oleyl amine envelope and deposited by the Langmuir-Blodgett technique onto Pt electrode covered with undoped hydrogenated amorphous silicon film is reported. Single-electron charging (so-called
quantized double-layer charging) of nanoparticles is detected by cyclic voltammetry as current peaks and the charging effect can be switched on/off by the electric field in the surface region induced by the excess of negative/positive charged defect states in the amorphous silicon layer. The
particular charge states in amorphous silicon are created by the simultaneous application of a suitable bias voltage and illumination before the measurement. The influence of charged states on the electric field in the surface region is evaluated by the finite element method. The single-electron
charging is analyzed by the standard quantized double layer model as well as two weak-link junctions model. Both approaches are in accordance with experiment and confirm single-electron charging by tunnelling process at room temperature. This experiment illustrates the possibility of the creation
of a voltage-controlled capacitor for nanotechnology.
Al3+ Environments in Nanostructured ZnAl2O4 and Their Effects on the Luminescence Properties
Authors: da Silva Alison A. , Gonçalves Agnaldo S. , Davolos Marian R. , Santagneli Silvia H.
Published: November 2008

Single-phase zinc aluminate (ZnAl2O4) with the spinel structure was successfully obtained by the Pechini method at different calcining temperatures for 4 hours. The nanoparticles are highly crystalline with no impurities related to ZnO or Al2O3
residues. The microstructural environment of aluminium ions changes with heat treatment temperature, as observed by Fourier transform infrared spectroscopy. The spinel structure might present two different AlO6 sites as evidenced by 27Al solid-state magic-angle-spinning
nuclear magnetic resonance spectra. Some AlO4 sites were also detected for samples calcined at a temperature lower than 900 °C. The photoluminescence spectra show that the emission can be tuned depending on the calcining temperature. This effect was discussed on the basis of
symmetry and oxygen vacancies.
Nanocasted Synthesis of Mesoporous Metal Oxides and Mixed Oxides from Mesoporous Cubic (Ia3d) Vinylsilica
Authors: Wang Yangang , Wang Yanqin , Liu Xiaohui , Guo Yun , Guo Yanglong , Lu Guanzhong , Schüth Ferdi
Published: November 2008

Mesoporous metal oxides and mixed oxides, such as NiO, CeO2, Cr2O3, Fe2O3, Mn2O3, NiFe2O4 and CexZr1−xO2 (x = 0.8 and 0.6) have
been synthesized by nanocasting from mesoporous cubic (Ia3d) vinyl-functionalized silica (vinylsilica). Their structural properties were characterized by XRD, TEM, N2-sorption and Raman spectra. Thus-prepared mesoporous materials possess a high BET surface area (110–190
m2g−1), high pore volume (0.25–0.40 cm3g−1) and relatively ordered structures. The catalytic properties of Cr2O3 were tested in the oxidation of toluene. The mesoporous Cr2O3 exhibits
unusually high catalytic activity in the complete oxidation of toluene as compared with commercial Cr2O3.
Fine Grained Ba1−xSrxTiO3 Ceramics by Spark Plasma Sintering
Authors: Tian Huyong , Chen Wanpin , Buckley C. E. , Chan H. L. W.
Published: November 2008

Fine grained Ba0.75Sr0.25TiO3 (BST) ceramics were prepared via spark plasma sintering technique. BST nano-powders freshly prepared by a low-temperature direct solution synthesis technique were used as starting materials. X-ray diffraction measurements
indicated that the ceramics had a pure perovskite phase and the observation under scanning electron microscope revealed that the ceramic had a grain size in the range of 50 to 300 nm. The dielectric properties of the fine-grained BST ceramics were determined at different temperatures and frequencies.
At room temperature, the ceramics exhibited a moderate dielectric constant (3962±10), a good dielectric tunability (53.84% under a dc bias of 19.72 kV/cm). The highest tunability and figure of merit (FOM) values are 83.27% at 50.2 °C and 289.28 at 62.3 °C, respectively. These
results suggested that the BST ceramics are suitable for use in tunable microwave devices.
Antimicrobial Activity of Organically Modified Nano-Clays
Authors: Hong Seok-In , Rhim Jong-Whan
Published: November 2008

Antimicrobial activity of three kinds of commercially available montmorillonite nano-clays including a naturally occurring one (Cloisite Na+) and two organically modified ones (Cloisite 20A and Cloisite 30B) against four representative pathogenic bacteria (two Gram-positive
ones such as Staphylococcus aureus and Listeria monocytogenes, and two Gram-negative ones such as Salmonella typhimurium and E. coli O157:H7) was investigated. Antimicrobial activity was found to be dependent on the type of nano-clay and microorganisms tested. Among
the nano-clays tested, Cloisite 30B showed the highest antibacterial activity followed by Cloisite 20A, however, the unmodified montmorillonite (Cloisite Na+) did not show any antibacterial activity. Especially, Cloisite 30B inactivated Gram-positive bacteria completely within an
hour of incubation and inactivated Gram-negative bacteria by more than 2–3 log cycles after 8 hours incubation. SEM and TEM images of cell structure indicated that the organically modified nano-clay caused rupture of cell membrane and inactivation of the bacteria. This finding of antimicrobial
activity of the organo-clay would open a new opportunity to develop polymer nanocomposites with additional functionality, i.e., antimicrobial function.
High-Strength Waterborne Polyurethane Reinforced with Waxy Maize Starch Nanocrystals
Authors: Wang Yixiang , Zhang Lina
Published: November 2008

High-strength elastic nanocomposite materials were successfully prepared from waxy maize starch nanocrystals as the reinforcing phase and waterborne polyurethane (WPU) as the matrix by casting and evaporating. Sulfuric acid hydrolysis of waxy maize starch granules yielded the crystalline
platelets of the starch nanocrystals with an average equivalent diameter of 25–40 nm. The morphology, thermal behavior and mechanical properties of the nanocomposite films were investigated by means of transmission electron microscopy, wide-angle X-ray diffraction, scanning electron
microscopy, ultraviolet-visible spectroscopy, thermogravimetric analysis, differential scanning calorimetry and tensile testing. The results revealed that the pre-dispersing process made a good effort on dispersing starch nanocrystals into the WPU matrix as small aggregates, and strong interactions
occurred between filler and matrix, leading to the efficient strengthening of the composites. The films having 1 wt% starch nanocrystal, rested for one week in 75% RH, exhibited a significant increase from 0.6 to 3.2 MPa for Young's modulus and from 10.4 to 24.1 MPa for tensile strength. Interestingly,
they showed high elongation at break, and remained basically in the range from 1148 to 1136%. Further, the WPU based composites possessed good thermal stability. This work provided a new environmentally friendly pathway to prepare WPU based elastomer with high strength.
Ambient Air Effects on Electrical Transport Properties of ZnO Nanorod Transistors
Authors: Park Jae Young , Kim Ju-Jin , Kim Sang Sub
Published: November 2008

ZnO nanorod (NR) transistors were fabricated in a back-gated structure, and their electrical transport properties were investigated as a function of air pressure. A large shift (19.4 V) of threshold voltage Vt, g toward negative gate bias is observed as the air pressure
decreases to 9.06 × 10−4 Pa. The shift of Vt, g and the change in the flowing current between the source and drain electrode with changing the air pressure are fully reversible. The adsorption and desorption of oxygen molecules and/or OH groups in air
are likely to be responsible for the reversibility. Most importantly, the electron concentration and the flowing current rapidly change only in a vacuum regime less than a certain pressure as likely as 1.33 × 10−1 Pa. In contrast, in the low vacuum regime (>1.33 ×
10−1 Pa) ZnO NR transistors are insensitive to the change of air pressure. This observation indicates that nanosized vacuum sensors based on ZnO NR transistors will be effective only in the high vacuum regime.
Nanoscale Chemical Effect on Friction Force
Authors: Hsieh Shuchen
Published: November 2008

Self-assembled alkylsilane monolayers reduce friction on silicon surfaces. Bias-assisted nanolithography can be used to create chemical patterns on such films by the process of local oxidation, whereby an atomic force microscope is used to scan a biased tip across the surface in a pre-defined
pattern. The chemistry of this process involves a redox reaction that oxidizes the terminal methyl groups of the film forming carboxyl groups in their place. In this study, we have prepared a sample designed specifically for measuring nanoscale chemical friction on a silicon substrate without
topography effects. This unique sample possesses wide regions of both oxidized and unmodified film within a small area, so that direct measurement of the relative friction between the two films can be made within a single 1 μm scan, eliminating tip and sample inconsistencies that
are common when comparing friction force measurements in consecutive scans or on different samples. Further, since the oxidation process modifies the film chemically, there is almost no contribution from the surface topography. We found that friction force increases as a function of applied
load for both types of terminal groups and that the coefficient of friction for the carboxyl terminated region is five times greater than for the methyl terminated region. Moreover, friction force decreases for both surfaces as the tip velocity increases, though much more dramatically for
the carboxyl terminated film. Both of these observations are consistent with a model that includes tip/sample bonding and localized condensation as the significant factors influencing chemically induced friction.
Highly Selective Determination of Dopamine in the Presence of Ascorbic Acid and Serotonin at Glassy Carbon Electrodes Modified with Carbon Nanotubes Dispersed in Polyethylenimine
Authors: Rodríguez Marcela C. , Rubianes María D. , Rivas Gustavo A.
Published: November 2008

We report the highly selective and sensitive voltammetric dopamine quantification in the presence of ascorbic acid and serotonin by using glassy carbon electrodes modified with a dispersion of multi-wall carbon nanotubes (MWCNT) in polyethylenimine, PEI (GCE/MWCNT-PEI). The electrocatalytic
activity of the MWCNT deposited on the glassy carbon electrode has allowed an important decrease in the overvoltages for the oxidation of ascorbic acid and dopamine, making possible a clear definition of dopamine, serotonin and ascorbic acid oxidation processes. The sensitivities for dopamine
in the presence and absence of 1.0 mM ascorbic acid and serotonin were (2.18±0.03 × 105 μAM−1 (r = 0.9998); and (2.10±0.07 × 105 μAM−1 (r = 0.9985), respectively, demonstrating
the excellent performance of the GCE/MWCNT-PEI. The detection limit for dopamine in the mixture was 9.2 × 10−7 M. The R. S. D. for the determination of 50 μM dopamine using four different electrodes was 3.9% when modified with the same MWCNT/PEI dispersion,
and 4.6% when using four different dispersions. The modified electrode has been successfully applied for recovery assays of dopamine in human blood serum. Therefore, the new sensor represents an interesting and promising alternative for the electrochemical quantification of neurotransmitters
and other analytes of clinical interest.
Synthesis and Optical Properties of Sulfide Nanoparticles Prepared in Dimethylsulfoxide
Authors: Li Yuebin , Ma Lun , Zhang Xing , Joly Alan G. , Liu Zuli , Chen Wei
Published: November 2008

Many methods have been reported for the formation of sulfide nanoparticles by the reaction of metallic salts with sulfide chemical sources in aqueous solutions or organic solvents. Here, we report the formation of sulfide nanoparticles in dimethylsulfoxide (DMSO) by boiling metallic
salts without sulfide sources. The sulfide sources are generated from the boiling of DMSO and react with metallic salts to form sulfide nanoparticles. In this method DMSO functions as a solvent and a sulfide source as well as a stabilizer for the formation of the nanoparticles. The recipe
is simple and economical making sulfide nanoparticles formed in this way readily available for many potential applications.
Photosensitizer-Loaded Magnetic Nanoemulsion for Use in Synergic Photodynamic and Magnetohyperthermia Therapies of Neoplastic Cells
Authors: Primo Fernando L. , Rodrigues Marcilene M. A. , Simioni Andreza Ribeiro , Lacava Zulmira G. M. , Morais Paulo C. , Tedesco Antonio C.
Published: November 2008

In this study a magnetic nanoemulsion (MNE) was developed from a mixture of two components, namely biodegradable surfactants and biocompatible citrate-coated cobalt ferrite-based magnetic fluid, for entrapment of Zn(II)-Phthalocyanine (ZnPc), the latter a classical photosensitizer (PS)
species used in photodynamic therapy (PDT) procedures. The sample's stability was evaluated as a function of time using photocorrelation spectroscopy (PCS) for determination of the average hydrodynamic diameter, diameter dispersion and zeta potential. The ZnPc-loaded magneto nanoemulstion
(ZnPc/MNE) formulation was evaluated in vitro assays to access the phototoxicity and the effect of application of AC magnetic fields (magnetohyperthermia damage) after incubation with J774-A1 macrophages cells. Darkness toxicity, phototoxicity and AC magnetic field exposures revealed
an enhancement response for combined photodynamic and magnetohyperthermia (MHT) processes, indicating the presence of the synergic effect.
Preparation and Luminescent Properties of Polymer Fibers Containing Y2O3:Eu Nanoparticles by Electrospinning
Authors: Yu Hongquan , Song Hongwei , Pan Guohui , Fan Libo , Li Suwen , Bai Xue , Lu Shaozhe , Zhao Haifeng
Published: November 2008

In this paper, composite fibers of polyvinylpyrrolidone (PVP) and Y2O3:Eu3+ nanocrytals were prepared by electrospinning and characterized by electron microscope, Fourier transform infrared spectra (FT-IR) and X-ray diffraction (XRD). The composite fibers
are in random orientation and with average diameter of ∼300 nm and length up to several ten micrometers. The luminescent properties were investigated and compared with the pure Y2O3:Eu3+ nanocrystals. Due to certain weak interactions between nanocrystals
and PVP matrix, charge transfer band in the excitation spectra show slightly red shift for the fibers relative to in the case of pure Y2O3:Eu3+ nanocrystals. The PVP polymer may modified the surface defect states of nanocrystals, yielding decreased intensity
ratio of 5D0–7F2 to 5D0–7F1 transition in the emission spectra. The fluorescence lifetimes of 5D0 level for Eu3+ in the composite fibers and Y2O3:Eu3+
nanocrystals were respectively determined to be 1.40 and 1.74 ms. The decreased fluorescence lifetime in the composite fibers was attributed to increased radiative transition rate, as result of the influence of refractive index of the surrounding PVP media instead of air.
Synthesis of Al-Catalyzed Si Nanowires Using the Al Remaining After Removal of Anodic Aluminum Oxide
Authors: Jung Jin-Young , Jee Sang-Won , Park Kwang-Tae , Lee Jung-Ho
Published: November 2008

Single-crystal, Al-catalyzed silicon nanowires were grown under atmospheric pressure using the dimpled feature of the Al metal that remained after removal of an anodic aluminum oxide (AAO) template directly formed on a Si substrate. Upon annealing in a hydrogen-rich atmosphere, the
dimpled morphology of Al was transformed into a smooth, rounded shape in which Si nanodots were periodically embedded due to Si migration from the substrate. The positions of the nanodots were exactly the same as the positions of sawtooth features on the dimpled surface. Although Al-catalyzed
silicon nanowires have been known to grow only under vacuum due to the tendency of Al to oxidize, these silicon nanodots, surrounded by residual Al, showed excellent resistance to oxidation under atmospheric pressure. These nanodots were also capable of acting as catalysts for the growth of
nanowires, and played a role in determining the diameter of the nanowires. A thinner residual Al layer made it easier to form Si nanodots while reducing the size of the nanodots, which subsequently led to the growth of nanowires with smaller diameters and better crystalline morphology.
Controlling the Catalyst During Carbon Nanotube Growth
Authors: Robertson J. , Hofmann S. , Cantoro M. , Parvez A. , Ducati C. , Zhong G. , Sharma R. , Mattevi C.
Published: November 2008

We have recently been able to grow single-walled carbon nanotubes by purely thermal chemical vapour deposition (CVD) at temperatures as low as 400 °C. This has been achieved by separating the catalyst pre-treatment step from the growth step. In the pre-treatment step, a thin film
catalyst is re-arranged into a series of nano-droplets, which are then the active catalysts. Both steps have been studied by in-situ environmental transmission electron microscopy and X-ray photoemission spectroscopy. We have also studied the catalyst yield, the weight of nanotubes
grown per weight of transition metal catalyst. Using very thin layers of Fe on Al2O3 support in a remote plasma-assisted CVD, we have achieved yields of order 100,000. This may be due to control of catalyst poisoning by ensuring an etching path.
Growth Window and Possible Mechanism of Millimeter-Thick Single-Walled Carbon Nanotube Forests
Authors: Hasegawa Kei , Noda Suguru , Sugime Hisashi , Kakehi Kazunori , Maruyama Shigeo , Yamaguchi Yukio
Published: November 2008

Our group recently reproduced the water-assisted growth method, so-called "SuperGrowth," of millimeter-thick single-walled carbon nanotube (SWNT) forests by using C2H4/H2/H2O/Ar reactant gas and Fe/Al2O3 catalyst. In
this current work, a parametric study was carried out on both reaction and catalyst conditions. Results revealed that a thin Fe catalyst layer (about 0.5 nm) yielded rapid growth of SWNTs only when supported on Al2O3, and that Al2O3 support enhanced
the activity of Fe, Co, and Ni catalysts. The growth window for the rapid SWNT growth was narrow, however. Optimum amount of added H2O increased the SWNT growth rate but further addition of H2O degraded both the SWNT growth rate and quality. Addition of H2
was also essential for rapid SWNT growth, but again, further addition decreased both the SWNT growth rate and quality. Because Al2O3 catalyzes hydrocarbon reforming, Al2O3 support possibly enhances the SWNT growth rate by supplying the carbon source
to the catalyst nanoparticles. The origin of the narrow window for rapid SWNT growth is also discussed.
Multi-Time Step Modeling of Plume Dynamics in Nanosecond-Scale Carbon Ablation
Authors: Pathak Kedar , Povitsky Alex
Published: November 2008

The time span of plume dynamics in laser ablation of carbon ranges from nanoseconds to milliseconds. Multi-time step approach is developed to study the plume dynamics over this entire range with minimum requirements of numerical computational resources. This approach is applied to study
one of the important aspects of nanosecond-scale laser ablation, namely the shielding of incident laser beam with previously ejected plumes. Capturing the shielding effect requires smaller than nanosecond-scale time step because of large velocity and pressure gradients in plume. Use of this
time step over the entire domain needs enormous amount of computer time to cover the whole time span of plume dynamics. Multi-time step modeling for such an application is therefore useful. In general, for nanosecond-scale laser ablation this shielding is caused by ionized particles and by
gas molecules. It is shown for carbon plume resulting from the nanosecond-scale lasers that the degree of ionization is small. Ionization of ablated carbon is estimated by Saha equation for the given initial plume conditions. The shielding of incident laser beam is therefore calculated by
normal molecular absorption. The laser-light intensity that reaches the target for subsequent pulses is evaluated.
Annual Cycle of Rainfall in the Western North Pacific and East Asian Sector
Authors: Chou Chia , Huang Li-Fan , Tseng Lishan , Tu Jien-Yi , Tan Pei-Hua
Published: November 2008

The annual cycle of precipitation over the western North Pacific and East Asian (WNP–EA) sector has five major periods: spring, the first and second wet periods, fall, and winter. In this study, processes that induce precipitation in each period are examined from a large-scale point of view. The wet phase over this sector has two distinct periods, which are dominated by the Asian summer monsoon circulation induced by the land–ocean contrast of net energy into the atmospheric column (Fnet). In the first wet period, the pre-mei-yu/mei-yu rainband is directly associated with a moisture flux convergence caused by the southwesterly Asian summer monsoon flow and the southeasterly trade winds, and indirectly associated with a dynamic feedback induced by this horizontal moisture convergence. The tropical convection, in the meantime, is associated with a rising motion that is induced by positive Fnet. In the second wet period, the WNP summer monsoon gyre dominates the rainfall of this region, which is partially associated with warmer local sea surface temperature (SST) via positive Fnet. The land–sea contrast of Fnet and the atmosphere–ocean interaction also play an important role in establishing the monsoon gyre. The dry phase over the WNP–EA region is the winter period in which precipitation is associated with winter storm activities and large-scale lifting associated with a pressure surge. In the two transition phases, due to a difference in heat capacity, the atmosphere and ocean have distinct impacts on precipitation, albeit similar solar insolations during the two periods. In the spring period, the atmospheric condition is favorable for convection, while the ocean surface is relatively colder, so the horizontal moisture advection associated with the westward extent of the Pacific subtropical high, which is different from a typical winter frontal system, is a major source for the spring rain. In the fall period, however, the atmospheric conditions dominated by the Asian winter monsoon circulation suppress convection, while relatively warmer SST still maintains tropical convection over the southern part of the WNP–EA region. Over the northern part of the WNP–EA region, the fall precipitation is associated with frontal systems, similar to those in winter.
Hadley Cell Widening: Model Simulations versus Observations
Authors: Johanson Celeste M. , Fu Qiang
Published: November 2008

Observations show that the Hadley cell has widened by about 2°–5° since 1979. This widening and the concomitant poleward displacement of the subtropical dry zones may be accompanied by large-scale drying near 30°N and 30°S. Such drying poses a risk to inhabitants of these regions who are accustomed to established rainfall patterns. Simple and comprehensive general circulation models (GCMs) indicate that the Hadley cell may widen in response to global warming, warming of the west Pacific, or polar stratospheric cooling. The combination of these factors may be responsible for the recent observations. But there is no study so far that has compared the observed widening to GCM simulations of twentieth-century climate integrated with historical changes in forcings. Here the Hadley cell widening is assessed in current GCMs from historical simulations of the twentieth century as well as future climate projections and preindustrial control runs. The authors find that observed widening cannot be explained by natural variability. This observed widening is also significantly larger than in simulations of the twentieth and twenty-first centuries. These results illustrate the need for further investigation into the discrepancy between the observed and simulated widening of the Hadley cell.
El Niño Impacts on Precipitation in the Western North Pacific–East Asian Sector
Authors: Chou Chia , Huang Li-Fan , Tu Jien-Yi , Tseng Lishan , Hsueh Yu-Chieh
Published: November 2008

In this study, the western North Pacific–East Asian (WNP–EA) rainfall anomaly induced by the strong El Niño in 1982–83, 1991–92, and 1997–98, and its association with the mean state, are examined. Over the northern part of the WNP–EA region (north of 20°N), which is dominated by southwest–northeast tilting frontal systems, positive rainfall anomalies from the fall before the El Niño peak phase (year 0) to the first wet period after the peak phase (year 1) are affected by low- and midlevel horizontal moisture convergence anomalies induced by low-level anticyclonic circulation anomalies over the WNP region that are associated with El Niño. Over the southern part of the WNP–EA region (south of 20°N), which is dominated by tropical convection, positive precipitation anomalies in the first and second wet periods of year 0 and negative precipitation anomalies from the fall of year 0 to the second wet period of year 1 are associated with the variation of the net energy into the atmosphere, which is mainly contributed to by local evaporation anomalies. The mechanisms for inducing the precipitation anomalies over both northern and southern parts of the WNP–EA region are similar to the mechanisms of the mean precipitation in each rainy period, but the detailed processes for the southern WNP–EA precipitation anomalies are more complicated, particularly in summer. In the first wet periods of years 0 and 1 and the fall of year 0, the precipitation anomalies are induced by evaporation anomalies that are contributed to by similar effects of sea surface temperature (SST) and wind speed anomalies. In the second wet period of years 0 and 1, on the other hand, near-surface wind speed anomalies affect precipitation via the process of evaporation. These wind speed anomalies are associated with the concurrence of the low-level circulation anomalies over the WNP region and the Asian summer monsoon trough. The SST anomalies are merely a response to evaporation and downward solar radiation anomalies. The dependence of the rainfall anomalies on the mean state, that is, similar causes for the rainfall mean and anomalies in each rainy period, implies that the mean state plays a key role in simulating the interannual variation over the WNP–EA region.
Social Class and Sickness Absence in Norway
Authors: Hansen Hans-Tore , Ingebrigtsen Tor
Published: November 2008

In this article we study class differences, as measured by the Erikson, Goldthorpe and Portocarero (EGP) class scheme, in long-term sickness absence, and, using data from three years of the Norwegian Level of Living Survey, we investigate the possible explanatory mechanisms for these differences in Norway. Our results show that there are class differences in sickness absence especially among men, but also among women. The two main underlying factors are education and physical work environment. The results suggest that selection mechanisms and material conditions are important, and prompt the question whether psychosocial work environment explains the marked class differences in sickness absence.
Bootstrap Standard Error and Confidence Intervals for the Difference Between Two Squared Multiple Correlation Coefficients
Authors: Wai Chan
Published: November 2008

A typical question in multiple regression analysis is to determine if a set of predictors gives the same degree of predictor power in two different populations. Olkin and Finn (1995) proposed two asymptotic-based methods for testing the equality of two population squared multiple correlations, ρ21 and ρ22. Simulation results indicated that these methods failed to perform accurately under certain model conditions (Algina & Keselman, 1999). In the present study, a unified bootstrap procedure is proposed for estimating the standard error of R 21 − R22 and constructing the confidence interval for ρ21 − ρ2 2. A simulation study was conducted to examine the empirical performance of the proposed procedure under different levels of ρ2, sample sizes, numbers of predictors, and types of data distribution. Results indicated that the asymptotic method, in general, can only work well with normal data. The bootstrap procedure, on the other hand, performs satisfactorily with both normal and nonnormal data. However, both methods fail when ρ2 1 and ρ22 are zero.
Afrocentric Humanism and African American Women’s Humanizing Activism
Authors: Harvell Valeria G.
Published: November 2008

Afrocentric scholars have consistently emphasized the thematic importance of the humanistic viewpoint to the overall liberation struggles of African Americans. Often, the essential principles defining this humanist outlook have been assumed rather than specified or described. This oversight has facilitated the exclusion of those who represent the main vanguards and chief practitioners of this humanistic vision of social change: African American women. Culling key points presented in the writings of mostly Afrocentric scholars, this article identifies some of the major tenets that characterize that humanistic perspective. It also discusses how African American women have interpreted and applied those principles through their activism in the Black community. Black women activists represent the best instructional models for discourse and analysis on the humanistic vision of liberation. The presentation also highlights what has been commonly perceived and subtly suggested as the feminine characteristics of the humanistic motif.
A Cosmopolitan Way of Life for All?
Authors: Carter J. Scott
Published: November 2008

The purpose of this article is to re-evaluate the independent impact of urban and regional residency on racial tolerance from 1972 to 2006. Recent scholarship has questioned the extent to which the effects of these subcultures reflect general toleration and/or more deep-seated underlying racial attitudes. Using data collected by the National Opinion Research Center’s General Social Survey, this article builds upon past research by including different measures of racial tolerance borrowed from the contemporary work of Schuman, Steeh, Bobo, and Krysan to reassess the impact of these subcultures over a four-decade period. Findings indicate that Southerners remain more obdurate regardless of how racial tolerance is measured and this effect appears to be persisting across the four-decade period. The impact of urbanism, on the other hand, and its effect across time is much more variable and dependent on how racial tolerance is measured. This article further discusses these findings in the framework of the classical theories of Louis Wirth and Samuel Stouffer.
Using Early Standardized Language Measures to Predict Later Language and Early Reading Outcomes in Children at High Risk for Language-Learning Impairments
Authors: Flax Judy F. , Realpe-Bonilla Teresa , Roesler Cynthia , Choudhury Naseem , Benasich April
Published: November 2008

The aim of the study was to examine the profiles of children with a family history (FH+) of language-learning impairments (LLI) and a control group of children with no reported family history of LLI (FH—) and identify which language constructs (receptive or expressive) and which ages (2 or 3 years) are related to expressive and receptive language abilities, phonological awareness, and reading abilities at ages 5 and 7 years. Participants included 99 children (40 FH+ and 59 FH—) who received a standardized neuropsychological battery at 2, 3, 5, and 7 years of age. As a group, the FH+ children had significantly lower scores on all language measures at 2 and 3 years, on selected language and phonological awareness measures at 5 years, and on phonological awareness and nonword reading at 7 years. Language comprehension at 3 years was the best predictor of later language and early reading for both groups. These results support past work suggesting that children with a positive family history of LLI are at greater risk for future language and reading problems through their preschool and early school-age years. Furthermore, language comprehension in the early years is a strong predictor of future language-learning status.
Language-Minority Learners in Special Education
Authors: Samson Jennifer F. , Lesaux Nonie K.
Published: November 2008

Using data from the Early Childhood Longitudinal Study—Kindergarten Cohort, this study was designed to investigate proportional representation, identification rates, and predictors of language-minority (LM) learners in special education using a nationally representative sample of kindergarten, first graders, and third graders. The findings indicate that although LM learners were underrepresented in special education in kindergarten and first grade, they were overrepresented in third grade across all disability categories. LM status, teacher ratings of language and literacy skills, and reading proficiency level were significant predictors of placement in special education. Kindergarten teacher ratings of language and literacy skills were highly predictive of subsequent placement in special education. The implications for developing a model of early identification, the response-to-intervention model in particular, for LM learners at risk for academic difficulties are discussed.
A Discriminant Analysis of the Factors Associated With the Career Plans of String Music Educators
Authors: Russell Joshua A.
Published: November 2008

The purpose of this study was to explore factors that may affect string teachers' career decisions. Six hundred string teachers were mailed a questionnaire designed to elicit responses about multiple factors and projected career plans in 1 year and in 5 years, and 304 teachers responded. The majority of teachers planned to remain in their positions the following year, whereas only half planned to remain in their positions in 5 years. Analyses indicated that work culture, perceptions about music's importance in the curriculum, satisfaction with student characteristics, psychological factors, and teacher socioeconomic background may affect immediate career plans. Further analyses indicated that work culture, satisfaction with student characteristics, psychological factors, and teaching experience were related to long-term career plans. In the Year 1 discriminant analysis, Stayers was the only group adequately classified. In the Year 5 analysis, Stayers were classified most accurately. Migrators and Leavers were classified slightly above the level of chance.
The Effect of Teacher Approval and Disapproval of Music Performed in a Rehearsal Setting on Music Preferences
Authors: Droe Kevin L.
Published: November 2008

The purpose of this study was to investigate the effects of teacher approvals and disapprovals of music performed in a rehearsal setting on the music preferences of middle school students. Students ( N = 440) from eight middle school bands participated in the study and were assigned one of four different rehearsal conditions. Teachers rehearsed either one or two assigned pieces of music, while implementing one of the following treatment conditions: (a) rehearsal of one piece with teacher approval and rehearsal of the other piece without comment; (b) rehearsal of one piece with teacher disapproval and rehearsal of the other without comment; (c) rehearsal of only one of the pieces, with teacher approval; and (d) rehearsal of only one of the pieces, with teacher disapproval. After five rehearsals of the music, students were given a listening survey on which to rate their preferences for the two compositions. Results indicated that the treatment conditions had a significant effect on preferences. Ratings from the approval treatment condition were significantly higher than those from the disapproval treatment condition.
Dream furniture
Authors: Phillips John
Published: November 2008

This article investigates the nature of the difference between the conscious acts of a rational subject and the enigmatic worlds of dream. In particular I am concerned with situations where the dream world is represented as effectively contaminating, surprising or, in more or less severe ways, influencing the world of consciously intended objects. Beginning with Wilfred Bion's explanation of how psychotic patients project parts of their ruined emotional life into their environment through the media of sense and sensation, the article aims to raise a question about these media and their connection to dream art.
Interpersonal Trust and Social Skill in Seeking Social Support Among Chinese and Americans
Authors: Mortenson Steven T.
Published: November 2008

The present study examined how social skills and interpersonal trust facilitate the support-seeking process in two different cultures, namely, those of China and the United States. Drawing from Sensitive Interactions Systems Theory and attachment theory, the current study examines the connections between social skill, interpersonal trust, the perceived appropriateness of seeking support, and the likelihood of displaying emotional distress to friends. Results indicated both similarities and differences between Americans and Chinese in terms of support seeking. Across both cultural groups, interpersonal trust was associated with appropriate help seeking, which, in turn, predicted the likelihood of showing emotional distress to friends. The two culture groups differed in terms of attenuating displays of distress (showing less than one actually feels). Among Chinese participants, attenuating displays of emotion was seen as positive and was associated with appropriateness. Among European Americans, attenuating displays of distress was negatively associated with appropriateness.
The Effects of Referent Item Parameters on Differential Item Functioning Detection Using the Free Baseline Likelihood Ratio Test
Authors: Lopez Rivas Gabriel E. , Stark Stephen , Chernyshenko Oleksandr S.
Published: November 2008

The purpose of this simulation study is to investigate the effects of anchor subtest composition on the accuracy of item response theory (IRT) likelihood ratio (LR) differential item functioning (DIF) detection (Thissen, Steinberg, & Wainer, 1988). Here, the IRT LR test was implemented with a free baseline approach wherein a baseline model was formed by freeing all items except a referent or anchor subset and examining the changes in fit with respect to a series of models wherein 1 item at a time was constrained in addition to the referent(s). The results clearly indicated that the composition of the anchor subtest is important for accurate DIF detection. It was found that using a single highly discriminating rather than a low discriminating referent greatly enhanced the power of the procedure. Moreover, in conditions involving small DIF or smaller sample sizes or both, power appeared to improve when a group of highly discriminating referents was used. These findings have implications for applied research involving short scales and small sample sizes.