bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of late Paleozoic volcanic arcs in the Canadian Cordillera: an example from the Klinkit Group, northern British Columbia and southern Yukon
Authors: Simard Renée-Luce , Dostal Jaroslav , Roots Charlie F
Published: September 2003

The late Paleozoic volcanic rocks of the northern Canadian Cordillera lying between Ancestral North America to the east and the accreted terranes of the Omineca belt to the west record early arc and rift magmatism along the paleo-Pacific margin of the North American craton. The Mississippian to Permian volcano-sedimentary Klinkit Group extends discontinuously over 250 km in northern British Columbia and southern Yukon. The two stratotype areas are as follows: (1) in the Englishman Range, southern Yukon, the English Creek Limestone is conformably overlain by the volcano-sedimentary Mount McCleary Formation (Lower Clastic Member, Alkali-Basalt Member and Volcaniclastic Member), and (2) in the Stikine Ranges, northern British Columbia, the Screw Creek Limestone is conformably overlain by the volcano-sedimentary Butsih Formation (Volcaniclastic Member and Upper Clastic Member). The calc-alkali nature of the basaltic volcaniclastic members of the Klinkit Group indicates a volcanic-arc setting ((La/Yb)N = 2.774.73), with little involvement of the crust in their genesis (εNd = +6.7 to +7.4). Alkali basalts in the Mount McCleary Formation ((La/Yb)N = 12.517.8) suggest periodic intra-arc rifting events. Broadly coeval and compositionally similar volcano-sedimentary assemblages occur in the basement of the Mesozoic Quesnel arc, north-central British Columbia, and in the pericratonic YukonTanana composite terrane, central Yukon, suggesting that they all represent pieces of a single long-lived, late Paleozoic arc system that was dismembered prior to its accretion onto Ancestral North America. Therefore, YukonTanana terrane is possibly the equivalent to the basement of Quesnel terrane, and the northern Quesnel terrane has a pericratonic affinity.
Emmons Lake Volcanic Center, Alaska Peninsula: source of the Late Wisconsin Dawson tephra, Yukon Territory, Canada
Authors: Mangan Margaret T , Waythomas Christopher F , Miller Thomas P , Trusdell Frank A
Published: September 2003

The Emmons Lake Volcanic Center on the Alaska Peninsula of southwestern Alaska is the site of at least two rhyolitic caldera-forming eruptions (C1 and C2) of late Quaternary age that are possibly the largest of the numerous caldera-forming eruptions known in the Aleutian arc. The deposits produced by these eruptions are widespread (eruptive volumes of >50 km3 each), and their association with Quaternary glacial and eolian deposits on the Alaska Peninsula and elsewhere in Alaska and northwestern Canada enhances the likelihood of establishing geochronological control on Quaternary stratigraphic records in this region. The pyroclastic deposits associated with the second caldera-forming eruption (C2) consist of loose, granular, airfall and pumice-flow deposits that extend for tens of kilometres beyond Emmons Lake caldera, reaching both the Bering Sea and Pacific Ocean coastlines north and south of the caldera. Geochronological and compositional data on C2 deposits indicate a correlation with the Dawson tephra, a 24 000 14C BP (27 000 calibrated years BP), widespread bed of silicic ash found in loess deposits in west-central Yukon Territory, Canada. The correlation clearly establishes the Dawson tephra as the time-stratigraphic marker of the last glacial maximum.
Utilisation de la scanographie pour l'étude des sédiments : influence des paramètres physiques, chimiques et biologiques sur la mesure des intensités tomographiques
Authors: Montety Laure de , Long Bernard , Desrosiers Gaston , Crémer Jean-François , Locat Jacques , Stora Georges
Published: September 2003

In July 1996, a flash flood resulted in the input of 9 million m3of sediment toward the Bay of Ha! Ha!, leading to the elimination, partly or totally, of the benthic fauna of the bay. In this study, the CT scanner has been used in a highly perturbed environment, the Bay of Ha! Ha!, to both assess (i) the relationships between the variations of tomographic intensities and the sedimentologic parameters of the sedimentary column and (ii) to quantify the biogenic structures resulting from the activity of benthic organisms. Compaction, CaCO3contents, and granulometry of sediments are the most important influences on the variation of tomographic intensities. The scanner allowed the study and quantification, in a non destructive way, of the sediment occupation by biogenic structures and, more particularly, allowed to further assess most of the relative importance of the fine fraction of biogenic structures (0.2501 mm) in the surface sediment layer (05 cm). Sediment occupation by biogenic structures reached maximal values at the upper part of the sedimentary column and decreased with depth. If sedimentary reworking leads to an increase in the sediment porosity, destabilization generated by the activity of organisms is balanced by the consolidation of the wall of the biogenic structures. Bioturbation resulting from the activity of benthic organisms into the sediments has a significant role on the sedimentary structure and biogeochemical processes. It is therefore necessary to quantify the volume of sediments occupied by biogenic structures to assess the activity of benthic organisms in the sedimentary column.
Geology, geochronology, and geochemistry of Archean rocks in the Eqe Bay area, north-central Baffin Island, Canada: constraints on the depositional and tectonic history of the Mary River Group of northeastern Rae Province
Authors: Bethune K M , Scammell R J
Published: September 2003

Results of stratigraphic, UPb geochronological, and geochemical study are reported for rocks in a 2800 km2 area along the southeastern margin of the Archean Rae Province on north-central Baffin Island. Archean rocks include a gneiss complex, two greenstone belts of the Mary River Group, and various younger plutonic rocks. The 30002800 Ma gneiss complex contains intrusions of orthogneiss, dated at 27802770 Ma. Intermediate-felsic volcanism in overlying greenstone belts occurred at 27402725 Ma and was accompanied and outlasted by calc-alkaline plutonism (27302715 Ma). Peraluminous plutonism at ca. 2700 Ma, possibly associated with low- to medium-pressure metamorphism, represents the culmination of the Archean tectonic cycle. Dating of metamorphic zircon and titanite in Archean gneissic rocks indicates that overprinting, high-grade metamorphism in the northwest part of the area (footwall of the Isortoq fault zone) is Paleoproterozoic (ca. 1820 Ma). A weaker, somewhat older thermal disturbance (ca. 18501840 Ma with large errors) is recorded in the hanging wall of this zone. Additional tectonothermal events at ca. 15001400 Ma and ca. 700 Ma may, respectively, correlate with Mesoproterozoic faulting and emplacement of the Franklin dyke swarm. Unlike their age-correlative counterparts in the Mary River area and on the mainland to the southwest, the greenstone belts at Eqe Bay lack abundant orthoquartzite and komatiitic volcanic rocks: calc-alkaline volcanic rocks predominate, suggesting a fundamentally different tectonic environment. Striking similarities, both in lithology and age, to greenstone belts of the Minto block of the Superior Province raises the question of RaeSuperior correlation.
Le bassin de Tizi n'Test (Haut Atlas, Maroc) : exemple d'évolution d'un segment oblique au rift de l'Atlantique central au Trias
Authors: Qarbous Abdelmounim , Medina Fida , Hoepffner Christian
Published: September 2003

Detailed mapping completed by a microtectonic study of the Tizi n'Test Triassic basin, located along the Tizi n'Test fault zone in the Moroccan High Atlas, has allowed us to improve the knowledge on the geometry of the structures and the activity of faults during the Triassic extensional events related to the rifting of the central Atlantic. The latter are reflected by the development of a rift, at present inverted and deformed by the collision of Africa and Europe, comprising kilometric-scale grabens and half-grabens bounded by major faults trending ENEWSW, with a dip towards the NNW, and a dip-slip syndepositional motion. Inverse analysis of fault slickenside populations shows a heterogeneous Triassic state of stress. However, in the most significant measurement sites, the maximum horizontal stress σ1 is vertical, while the minimum stress σ3 is horizontal with a NWSE trend. The strike-slip component appears to be very small during the Triassic, a noticeable fact because of the obliquity of the basin with respect to the Atlantic rift.
Basin architecture and density structure beneath the Strait of Georgia, British Columbia
Authors: Lowe C , Dehler S A , Zelt B C
Published: September 2003

Georgia Basin is located within one of the most seismically active and populated areas on Canada's west coast. Over the last decade, geological investigations have resolved important details concerning the basin's shallow structure and composition. Yet, until recently, relatively little was known about deeper portions of the basin. In this study, new seismic velocity information is employed to develop a 3-dimensional density model of the basin. Comparison of the calculated gravity response of this model with the observed gravity field validates the velocity model at large scales. At smaller scales, several differences between model and observed gravity fields are recognized. Analysis of these differences and correlation with independent geoscience data provide new insights into the structure and composition of the basin-fill and underlying basement. Specifically, four regions with thick accumulations of unconsolidated Pleistocene and younger sediments, which were not resolved in the velocity model, are identified. Their delineation is particularly important for studies of seismic ground-motion amplification and offshore aggregate assessment. An inconsistency between the published geology and the seismic structure beneath Texada and Lasqueti Islands in the central Strait of Georgia is investigated; however, the available gravity data cannot preferentially validate either the geologic interpretation or the seismic model in this region. We interpret a northwest-trending and relatively linear gradient extending from Savory Island in the north to Boundary Bay in the south as the eastern margin of Wrangellia beneath the basin. Finally, we compare Georgia Basin with the Everett and Seattle basins in the southern Cascadia fore arc. This comparison indicates that while a single mechanism may be controlling present-day basin tectonics and deformation within the fore arc this was not the case for most of the Mesozoic and Tertiary time periods.
A new species of catfish (Claroteidae, Chrysichthys) from an Eocene crater lake in East Africa
Authors: Murray Alison M , Budney Lisa A
Published: September 2003

Several specimens of a fossil catfish, collected from the Eocene Mahenge site of Tanzania, are identified as a member of Chrysichthys (Claroteidae) based on several features, including long, thick pectoral and dorsal spines and the presence of nasal barbels. The fossil fish is described as a new species based on unique characters (e.g., 20 principal caudal fin rays). The fossil record of Siluriformes in Africa includes few articulated skeletons; isolated spines or crania are more common. Although several African Eocene catfish crania previously have been described in their own genera, the Mahenge specimens preserve details that indicate their relationship to the living genus Chrysichthys, and therefore the new species is included in that genus instead of being given its own. Previously, the oldest record for Chrysichthys was from the Pliocene; these specimens extend the range of Chrysichthys back to the Eocene. The Mahenge locality itself is significant because it contributes knowledge of the poorly known sub-Saharan Eocene fauna and flora.
Distinguishing between Archean and Paleoproterozoic tectonism, and evolution of the Isortoq fault zone, Eqe Bay area, north-central Baffin Island, Canada
Authors: Bethune K M , Scammell R J
Published: September 2003

Structural, metamorphic, and UPb geochronological data bear on the distinction between Archean and Paleoproterozoic tectonism along the southeastern margin of the Rae Province on Baffin Island. Archean rocks include ca. 3.02.8 Ga gneiss, two greenstone belts of the Mary River Group, and various younger granitoid intrusions. In the greenstone belts, intermediatefelsic volcanism (2.742.725 Ga) was accompanied and outlasted by calc-alkaline plutonism (2.732.715 Ga). Deformation, low- to medium-pressure metamorphism, and peraluminous plutonism followed at ca. 2.7 Ga. Archean rocks and the locally overlying Piling Group (ca. 2.21.9 Ga) were deformed and metamorphosed together during development of the Paleoproterozoic Foxe fold belt. Tectonism is linked to the Isortoq fault zone, a major southeast-dipping structure marking an abrupt northwestward transition to granulite facies. Within a 5-km-wide zone, tight folds of the Archean Mary River Group give way down-section to moderately southeast-dipping, highly transposed, high-grade gneissic rocks. Several northeast- and north-striking ductilebrittle faults, some recording normal-sinistral oblique displacement, truncate early gneissosity and folds. This progression, along with UPb metamorphic ages, suggests early northwest-directed thrusting, starting at ca. 1.85 Ga, with peak metamorphism in the footwall at ca. 1.831.82 Ga. Later extensional displacement caused juxtaposition of lower grade on higher grade rocks. Archean ages of metamorphism (and deformation) are well preserved only in the hanging wall and the youngest metamorphic ages are restricted to the footwall. The data indicate that mountain building involved thrust-related thickening followed by gravitational collapse, a sequence characteristic of Phanerozoic orogens.
Assessment of landslide hazard under combined loading
Authors: Wu Tien H
Published: September 2003

A method for assessing landslide hazard under combined loading is described. The loads are considered as pulses that occur randomly in time. The method accounts for the rate of occurrence and the duration of the loads and calculates the rate of coincidence of two or more loads. This is used to calculate the failure probability, which is equal to the probability that the load combination will exceed a threshold value during a given time period. The method was applied to a site in the Cascade Mountains of Washington. The loads considered include those as a result of gravity, pore pressure from infiltration of rainfall plus snowmelt, loss of root reinforcement through fire or logging, and earthquakes. The example demonstrates a rational approach that accounts for the properties of the loads and the different loading conditions that may be expected.Key words: earthquake, failure probability, landslide hazard, load coincidence, load combination, pore pressure, root reinforcement.
Numerical analysis of seismically induced liquefaction in earth embankment foundations. Part I. Benchmark model
Authors: Aydingun Ogun , Adalier Korhan
Published: September 2003

A numerical analysis has been performed for a clayey embankment founded on a liquefiable foundation soil using an effective stress based, fully coupled, finite element code called DIANA-SWANDYNE II. The results were compared with data obtained from centrifuge experiments. In Part I, the numerical method and the analysis procedure are explained. The results obtained for a series of three consecutive, increasing amplitude shaking events are presented. An attempt has been made to calibrate a benchmark model to be used in the application of different remedial measures which are discussed in Part II. The numerical predictions compared well with the experimental data and provided further insights into the dynamic behavior of embankmentfoundation systems.Key words: liquefaction, numerical modeling, coupled formulation, centrifuge, embankment, earthquakes.
An explicit analytical solution for calculating horizontal stress changes and displacements around an excavated diaphragm wall panel
Authors: Ng C WW , Lei G H
Published: September 2003

A new, simple, and explicit analytical solution has been derived for calculating horizontal stress changes and displacements caused by the excavation for a diaphragm wall panel. The theoretical solution is obtained by applying the principle of superposition appropriately to model diaphragm wall construction using a basic elastic solution to the problem of an infinite horizontal plate with a rectangular opening subjected to a uniaxial stress at infinity. The basic elastic solution can be obtained by using the method of complex variables with a simplified conformal transformation function. Key parameters governing the magnitude of horizontal stress changes and displacements are identified. Computed results are given in a normalized form in terms of aspect ratio (length to width) of a diaphragm wall panel. Two extreme cases for diaphragm wall panels with dimensions 1 m × 1 m and 10 m × 1 m have been analysed to investigate the distributions of stress changes and deformations around the panels during the bentonite stage. By performing a parametric study, calculation charts have been developed for computing horizontal stress changes and displacements for practising engineers and researchers to carry out preliminary designs and for numerical modellers to verify their sophisticated predictions. The ease of use of the charts is illustrated by two examples, and the limitations of the derived solutions are discussed.Key words: diaphragm wall, elasticity, stress change, displacement, stress analysis, earth pressure.
Influence of a permanent liner on the skin friction of large-diameter bored piles in Hong Kong granitic saprolites
Authors: Lo S -C.R , Li K S
Published: September 2003

The skin friction of large-diameter bored piles in Hong Kong granitic saprolite manifested high variability. The influence of one construction detail, a full-length permanent liner, is studied by examining full-scale load test results and by numerical simulation of this construction detail. It is concluded that the use of a full-length liner will give very low skin friction because the local method of constructing a large-diameter bored pile with a full-length permanent liner leads to a significant reduction in radial stress acting on the pilesoil interface.Key words: construction, pile, stress, skin friction, numerical simulation.
Établissement d'une méthode de caractérisation minéralogique décrivant les sols contaminés par le plomb
Authors: Duchesne Josée , Mercier Guy
Published: September 2003

Many metal-contaminated soils originate in old abandoned industrial sites. One of the problems encountered in the reclamation of soils lies in the selection of the decontamination techniques. Few data are available to predict the efficiency of the extraction of metals from the contaminated soils. Moreover, a signifiant part of the contamination is often found as particles. These can be extracted from the soils by means of mineralurgical separation techniques. A trial and error procedure is often used for selecting the technique and the procedure parameters. The purpose of this study is to develop a method of mineralogical characterization for the identification and localisation of the metal contamination so as to allow a more enlightened choice of the mineralurgical treatments. Besides the identification of the contaminant particles, the method takes into account the distribution of contaminants, which can be found on the surface of the particles or included within the volume of the particle, the average proportion and the size of the contaminants in the contaminated particles, and the association of the iron oxide contaminant. The frequency of appearance of the particles depending on the different categories of the method guides the choice of the treatment technologies to be used so as to optimize the extraction of contaminant particles.Key words: metals, contamination, soils, lead, mineralurgical techniques, mineralogy.[Journal translation]
Upper bound limit analysis of slope stability using rigid finite elements and nonlinear programming
Authors: Chen Jian , Yin Jian-Hua , Lee C F
Published: September 2003

In this paper, the development and application of a new upper bound limit method for two- and three-dimensional (2D and 3D) slope stability problems is presented. Rigid finite elements are used to construct a kinematically admissible velocity field. Kinematically admissible velocity discontinuities are permitted to occur at all inter-element boundaries. The proposed method formulates the slope stability problem as an optimization problem based on the upper bound theorem. The objective function for determination of the minimum value of the factor of safety has a number of unknowns that are subject to a set of linear and nonlinear equality constraints as well as linear inequality constraints. The objective function and constrain equations are derived from an energywork balance equation, the MohrCoulomb failure (yield) criterion, an associated flow rule, and a number of boundary conditions. The objective function with constraints leads to a standard nonlinear programming problem, which can be solved by a sequential quadratic algorithm. A computer program has been developed for finding the factor of safety of a slope, which makes the present method simple to implement. Four typical 2D and 3D slope stability problems are selected from the literature and are analysed using the present method. The results of the present limit analysis are compared with those produced by other approaches reported in the literature.Key words: limit analysis, upper bound, rigid finite element, nonlinear programming, sequential quadratic algorithm, slope stability.
Voltammetric studies and assay of the anti-inflammatory drug ketoprofen in pharmaceutical formulation and human plasma at a mercury electrode
Authors: Ghoneim M M , Tawfik A
Published: September 2003

The electrochemical reduction of the anti-inflammatory drug ketoprofen was studied in a Britton-Robinson (B-R.) buffer series of pH 211 using dc-polarography, cyclic voltammetry, and coulometry techniques. The electrode reaction pathway of the drug at the dropping mercury electrode was proposed and discussed. A new adsorptive cathodic stripping square-wave voltammetric procedure was optimized for the assay of bulk drug in a B-R. buffer of pH 2.0. The peak current was linear with the drug concentration over the ranges 2 × 109 to 2 × 107 M of the bulk drug, using a 60 s accumulation time period at 0.6 V (vs. Ag/AgCl/KCls). The percentage recovery of the bulk drug was 99.57 ± 0.54 and a detection limit of 0.10 ng mL1 was achieved. The proposed procedure was successfully applied for the assay of ketoprofen in pharmaceutical formulation (Ketofan®) and human plasma. The percentage recoveries were 99.66 ± 0.47 and 101.76 ± 0.64 in pharmaceutical formulation and human plasma, respectively. A detection limit of 0.14 ng mL1 plasma was achieved which was below that reported in literature using the different analytical techniques.Key words: ketoprofen (Ketofan®) determination, polarography, cyclic voltammetry, adsorptive cathodic stripping square-wave voltammetry, human plasma.
A new class of bolaforms bearing sulfobetaine and cationic heads: Synthesis and aggregation properties
Authors: Souirti Souad , Baboulene Michel
Published: September 2003

We describe here a convenient route to a new family of bolaforms bearing sulfobetaine and cationic heads, which could be scaled up for industrial applications. Their aggregation modes were studied by measurement of surface tension and by dynamic light scattering and transmission electronic microscopy methods. Grafting a hydrophobic chain onto the cationic head modifies both the surface properties and aggregation. Compared to conventional bolaforms, the relationship between the length of the spacer and the side-chain and the resultant hydrophobic interactions are at the origin of these novel properties. Various models of these molecular associations were proposed.Key words: dissymmetric bolaform, sulfobetaine, cationic amphiphile, aggregation.
The activity of 3- and 7-hydroxyflavones as scavengers of superoxide radical anion generated from photo-excited riboflavin
Authors: Montaña Paulina , Pappano Nora , Debattista Nora , Ávila Vicente , Posadaz Ariana , Bertolotti Sonia G , García Norman A
Published: September 2003

The visible-light irradiation of the system Rivoflavin plus 3-hydroxyflavone or plus 7-hydroxyflavone, under aerobic conditions, produces a series of competitive processes that depend on the relative concentrations of the pigment and the flavones. The picture comprises photochemical mechanisms that potentially operate in nature. They mainly include the quenching of Rf singlet (1Rf*) and triplet (3Rf*) excited states (with bimolecular rate constants in the order of 109 M1 s1) and superoxide radical anion-mediated reactions. The participation of the oxidative species singlet molecular oxygen was not detected. The overall result shows chemical transformations in both Rf and 3-hydroxyflavone. No experimental evidence was found indicating any chemical reaction involving 7-hydroxyflavone. The fate of the pigment also depends on the amount of the dissolved flavonoid. At 50 mM concentrations of these compounds or higher, practically no photochemistry occurs, owing to the extensive quenching of 1Rf*. When the concentration of the flavones is in the mM range or lower, 3Rf* is photogenerated. Then, the excited triplet species can be quenched mainly by the flavones through an electron-transfer process, yielding the semireduced pigment. The latter interacts with dissolved oxygen producing O2·, which reacts with both the pigment and 3-hydroxyflavone. In summary, 3-hydroxyflavone and 7-hydroxyflavone participate in the generation of superoxide ion in an Rf-sensitized process, and simultaneously 3-hydroxyflavone constitutes a degradable quencher of the oxidative species.Key words: flavones, riboflavin, sensitization, singlet molecular oxygen, superoxide radical anion.
Phase behaviour and structure of amphiphilic poly(ethylene oxide)-poly(propylene oxide) triblock copolymers ((EO)4(PO)59(EO)4 and (EO)17(PO)59(EO)17) in ternary mixtures with water and xylene
Authors: Kipkemboi Pius , Khan Ali , Lindman Björn , Alfredsson Viveka
Published: September 2003

The isothermal ternary phase behaviour and structure of amphiphilic copolymerwaterxylene systems was investigated for two poly(ethylene oxide)poly(propylene oxide) (PEOPPO) triblock copolymers, (EO)4(PO)59(EO)4 and (EO)17(PO)59(EO)17, at 25°C. The phase boundaries were identified using 2H NMR and inspection under polarized light. The microstructure and structural length scales in the lyotropic liquid crystalline phases were determined and characterized by small-angle X-ray scattering. The amounts and relative proportions of the selective solvents can modulate the resulting microstructures, although the phase sequence observed depends on the relative PEOPPO block ratio. A variety of lyotropic liquid crystalline (LLC) phases are thermodynamically stable in the system with copolymer (EO)17(PO)59(EO)17, both of the normal ("oil-in-water") and of the reverse ("water-in-oil") morphology. The high hydrophobic content of copolymer (EO)4(PO)59(EO)4, however, favours reverse LLC structures with low interfacial curvature. No normal LLC phases are formed by this system.Key words: amphiphilic, triblock copolymers, poly(ethylene oxide), poly(propylene oxide), ternary mixtures, phase behaviour, lyotropic liquid crystals, SAXS, 2H NMR.
5-Hydroxy[1,2]oxazinan-3-ones as potential carbapenem and D-ala-D-ala surrogates
Authors: Wolfe Saul , Akuche Christiana , Ro Stephen , Wilson Marie-Claire , Kim Chan-Kyung , Shi Zheng
Published: September 2003

The title compounds are amino acids whose nitrogen atom is enclosed in a six-membered cyclic hydroxamate bearing a C5-hydroxyl group. They belong to a proposed new family of antibacterial agents targeted to the penicillin receptor. The glycine and alanine members of the family have been synthesized, as racemates, in seven steps from the four-carbon synthon diketene and the tert-butyl esters of N-hydroxyglycine and N-hydroxyalanine. Numerous alternatives to diketene have also been examined, but these lead mainly to five-membered cyclic hydroxamates. The theoretical considerations that have led to this synthetic programme are discussed in some detail. They include analysis of the structures of natural and unnatural penicillin surrogates, analysis of the penicillin pharmacophore, and a treatment of the chemical reaction with which penicillin blocks bacterial cell wall synthesis. The glycine derivative exhibits marginal but real activity vs. Micrococcus luteus. The alanine derivative, which more closely resembles D-ala-D-ala, is fifty times more active. Two five-membered structural isomers of the glycine derivative are inactive. Key words: cyclocanaline, cycloserine, lactivicin, oxamazins, peptidoglycan, penicillin-binding proteins.
CHARACTERISTICS AND MICROPATTERNING OF SPIN SELF-ASSEMBLED ULTRATHIN MULTILAYERS
Authors: CHAR KOOKHEON , KIM SANGCHEOL , CHO JINHAN , SOHN HIESANG , JANG HONGSEOK
Published: September 2003

A new method is introduced to build organic/organic multilayer films composed of cationic poly(allylamine hydrochloride) (PAH) and negatively-charged poly(sodium 4-styrenesulfonate) (PSS) using the spinning process. The adsorption process is governed by both the viscous force induced by fast solvent elimination and the electrostatic interaction between oppositely-charged species. On the other hand, the centrifugal and air shear forces applied by the spinning process enhance significantly the desorption of weakly-bound polyelectrolyte chains and also induce the planarization of the adsorbed polyelectrolyte layer. The surface of the multilayer films prepared with the spinning process is quite homogeneous and smooth. Also, a new approach to create multilayer ultrathin films with well-defined micropatterns in short process time is introduced. To achieve such micropatterns with high line resolution in organic multilayer films, microfluidic channels were combined with the convective self-assembly process employing both hydrogen bonding and electrostatic intermolecular interactions. As a next step, we extended the spin SA to the fabrication of multilayer micropatterns with vertical heterostructure.
BIONANOMAGNET AND ITS APPLICATION
Authors: MATSUNAGA TADASHI , OKAMURA YOSHIKO
Published: September 2003

Magnetic bacteria synthesize intracellular magnets which are encapsulated by lipid bilayer membranes. Easy aqueous dispersion of bacterial magnetic particles (BMPs) enable development of highly sensitive chemiluminescence enzyme immunoassays by antibodies on BMP surfaces. We have reported a technique for preparing recombinant BMPs on which proteins were displayed by gene-fusion. We further applied such recombinant BMPs to biotechnologically-important issues, including novel bioassay platforms for medicine and environmental management.
EFFECT OF LIPID-PACKAGING ON THE CHARGE TRANSFER CHARACTERISTICS OF ONE-DIMENSIONAL, MIXED-VALENCE PLATINUM COMPLEXES
Authors: LEE CHANG-SOO , HATANAKA YASUHIRO , KIMIZUKA NOBUO
Published: September 2003

Lipid-packaged platinum complexes of [ Pt ( en )2][ Pt X2( en )2] (X= Cl , Br , I ) are newly synthesized and their morphology and charge transfer (CT) absorption characteristics are compared in organic media. They show remarkably red-shifted CT absorption characteristics, which are ascribed to the significantly promoted exciton delocalization along the chains.
SELF-ORGANIZATION OF METAL NANOPARTICLES AND ITS APPLICATION TO SYNTHESES OF Pd/Ag/Rh TRIMETALLIC NANOPARTICLE CATALYSTS WITH TRIPLE CORE/SHELL STRUCTURES
Authors: TOSHIMA NAOKI , SHIRAISHI YUKIHIDE , MATSUSHITA TORU , MUKAI HISAYOSHI , HIRAKAWA KAZUTAKA
Published: September 2003

Self-organization of metal nanoparticles, which is observed by mixing Ag nanoparticles and precious metal nanoparticles, is applied to the synthesis of Pd/Ag/Rh trimetallic nanoparticles having a Pd-core/Ag-interlayer/Rh-shell structure. These trimetallic nanoparticles work as a more active catalyst for hydrogenation of olefin than the corresponding monometallic and bimetallic nanoparticles.
LIPOPHILIC-FULLERENE DERIVATIVE MONOLAYERS AT THE AIR–WATER INTERFACE
Authors: KOO J. S. , SHIN K. , JENG U. , LIN T.-L. , WU M. H. , CHI Z. A. , SHIH M. C. , HSU C.-H. , LEE H.-Y. , CHIANG L. Y.
Published: September 2003

Monolayers of a lipophilic C 60-derivative (FPTL) mixed in dipalmitoyl-phosphatidyl-choline (DPPC) have been studied by the Langmuir film balance technique and Brewster angle microscopy. Previous X-ray scattering studies showed that the FPTL molecules intercalated into the DPPC monolayers and modified the bending and compression modulus of the host DPPC membranes. Combined study of surface pressure–area isotherms and Brewster angle microscopy measurements clearly established that the liquid-condensed domain structures are strongly influenced by an addition of the fullerene bearing lipid molecules, where it caused smaller liquid-condensed domain structures.
NANOSTRUCTURED LB FILMS AND EMISSION LIGHT DUE TO MULTIPLE SURFACE PLASMON EXCITATIONS IN THE KRETSCHMANN CONFIGURATION
Authors: KANEKO FUTAO , TERAKADO MITSURU , SATO TOSHIHARU , HATAKEYAMA HIROTSUGI , SAITO WATARU , SHINBO KAZUNARI , KATO KEIZO , WAKAMATSU TAKASHI
Published: September 2003

Surface plasmon (SP) excitations have been investigated in the attenuated total reflection (ATR) Kretschmann configuration of prism/metal/Langmuir–Blodgett (LB) films containing dyes. The emission light through the prism was observed using direct irradiation of a laser beam from air to the LB films, i.e., reverse irradiation. The emission intensities depend on the emission angles through the prism, nanostructure of metal and LB films, dye molecules, separation between metal and dye molecules, interactions of dye molecules, etc. The spectra is strongly depended on the emission angles, and the emission light was caused by multiple SP excitations. Nanostructured devices of LB films using SP excitations are described.
"HONEYCOMB FILMS": BIOINTERFACE FOR TISSUE ENGINEERING
Authors: NISHIKAWA TAKEHIRO , ARAI KEIKO , HAYASHI JUNKO , HARA MASAHIKO , SHIMOMURA MASATSUGU
Published: September 2003

We report that tissue-like structure can be formed when cells are cultured on a microporous polymer film (honeycomb film). The honeycomb films were fabricated by applying a moist air to a spread polymer solution containing biodegradable polymers (poly(L-lactic acid) (PLLA) and poly(ε-caprolactone) (PCL)) and an amphiphilic polymer. Hepatocytes were cultured on a self-supporting honeycomb film of PLLA. The hepatocytes formed a single layer of columnar shape cells with a thickness of 20 μm. The tissue formation of hepatocytes was specifically occurred on the honeycomb film of PLLA and not on a flat film of PLLA. Three-dimensional tissue structures were formed, when cells were cultured on both sides of the self-supporting honeycomb film. Double layers of hepatocytes were obtained by the method. Striated tissues such as heart and blood vessel could be reconstructed by utilizing a stretched honeycomb film of PCL.
SURFACE STRUCTURE AND PROPERTIES OF MULTICOMPONENT MICROPATTERNED ORGANOSILANE MONOLAYERS PREPARED BY STEPWISE PHOTODECOMPOSITION AND CHEMISORPTION PROCESS
Authors: KOGA TOMOYUKI , MORITA MASAMICHI , SAKATA HIROKI , OTSUKA HIDEYUKI , TAKAHARA ATSUSHI
Published: September 2003

Multicomponent micropatterned organosilane monolayers were successfully fabricated on Si substrate by stepwise vacuum ultraviolet-ray (VUV) photodecomposition and chemisorption process. The area-specific introduction of different organosilane molecules was confirmed by X-ray photoelectron spectroscopy (XPS). Atomic force microscopic (AFM) observation and lateral force microscopic (LFM) measurement revealed that the line-widths of the micropatterned surface corresponded to those of photomask. Micropatterning of the functional groups influenced the magnitudes of the surface free energy. The patterned surface was also applied for the site-specific polymerization and site-specific adsorption of microparticles.
MECHANICAL PROPERTIES OF SURFACTANT-COATING CARBON NANOFIBER/EPOXY COMPOSITE
Authors: YING ZHE , DU JIN-HONG , BAI SHUO , LI FENG , LIU CHANG , CHENG HUI-MING
Published: September 2003

Carbon nanofibers (CNFs) were coated by surfactants of polyoxyetheylene alkyl ether ( AEO 9, AEO 7) and polyvinyl alcohol (PVA 1799), respectively, after being mixed with surfactant aqueous solution and then treated with ultrasonication, high shear and magnetic stirring. The CNF/epoxy composites were prepared by mixing the surfactant coated CNFs with epoxy. Tensile strength, elastic modulus and ultimate strain of the composites were studied. The tensile strength and the ultimate strain of the composites were increased by 20% and 70%, respectively, after the CNFs were coated by surfactants. However, the elastic modulus of the composite will be lowered when the CNFs were treated by too high a concentration of surfactant solution.
PREPARATION OF CUBE-SHAPED CdS NANOPARTICLES BY SONOCHEMICAL METHOD
Authors: WANG HUI , LU YINONG , ZHU JUNJIE
Published: September 2003

Cube-shaped CdS nanoparticles have been successfully prepared by a sonochemical method in an oil-in-water microemulsion. The product was characterized by using techniques including X-ray powder diffraction, high-resolution transmission electron microscopy, energy-dispersive X-ray analysis and UV-visible absorption spectroscopy. This microemulsion system in the presence of high-intensity ultrasound irradiation provides special conditions for the nucleation and growth of the CdS nanoparticles.
XANES STUDY OF COPPER NANOPARTICLES IN THE ELECTROCHEMICAL REACTION OFLiWITHCuO
Authors: CHOI HYUN CHUL , JUNG YOUNG MEE , KIM SEUNG BIN
Published: September 2003

The electrochemical insertion–deinsertion of lithium into CuO electrode was examined by Cu K-edge X-ray absorption near edge structure (XANES) during the first electrochemical cycle. The XANES spectra in the LixCuO (x: lithium content) system reveal that the initial insertion of lithium leads to the reduction of the Cu2+in the pristine CuO to form the reduced nanosized Cu metal. In the successive deinsertion of lithium, the reduced Cu particles changed partially to the phase of Cu2O .
SELF-ASSEMBLED NANOSTRUCTURES OF A BOLAAMPHIPHILIC DIACID IN THE SPREAD LANGMUIR FILM ON THE AQUEOUS SUBPHASE CONTAINING LANTHANUM ION
Authors: LIU MINGHUA , IIMURA KEN-ICHI , KATO TEIJI
Published: September 2003

The spreading behavior of a bolaamphiphilic diacid (1,18-octadecanedicarboxylic acid, ODA) on an aqueous subphase containing lanthanum chloride was investigated. ODA formed a multilayer film on the subphase, and flower- or ring-like nanoarchitectures were observed by an AFM measurement on the transferred one-layer film. It was found that while the above exotic nanostructures were formed in the spreading films at lower concentration of La 3+ ion, only aggregated circular nanoparticles were observed for those on a higher concentration of La 3+ ion.
SYNTHESIS OF NOVEL MANGANESE-BASED SINGLE-MOLECULE NANOMAGNETS
Authors: KIM JINKWON , CHO HAENGKYU , GUPTA AHKILESH K. , LIM JIN MOOK , DO YOUNGKYU
Published: September 2003

New Mn12 single-molecule nanomagnets [ Mn 12 O 12( O 2 CCHCl 2)( H 2 O )4]· 2CH 2 Cl 2· H 2 O and [ Mn 12 O 12( O 2 CCHCl 2)( H 2 O )4]· 2CH 3 C 6 H 5· 4H 2 O and novel Mn18 complexes [ M 18 O 14( O 2 CR )18( hmp )4( hmpH )2( H 2 O )2] (R=Me, Et) have been synthesized and characterized by single crystal X-ray crystallography and dc- and ac-magnetic susceptibility measurements. Mn12 complexes show characteristic SMM properties, such as temperature-dependent out-of-phase ac-susceptibility. Mn18 does not show relaxation behaviors down to 2.0 K, but reveals magnetic anisotropy in reduced magnetization experiment.
SIZE EFFECT OF CYANINE DYE J-AGGREGATES IN MICROMETER-SIZED POLYMER "DOMES"
Authors: KARTHAUS OLAF , OKAMOTO KIYOSHI , CHIBA RYOTA , KAGA KAZUAKI
Published: September 2003

The fluorescence behavior of 3,3′diethyl-thiacarbocyanine iodide in micrometer-sized polystyrene droplets, or "domes" on glass substrates was investigated. The samples were prepared by casting dilute polymer/dye solutions onto the substrates. A dewetting process leads to the formation of small polymer domes with a diameter of 1–100 μm and a height of 100 nm to several μm. Fluorescence microscopy shows that the dye is incorporated into these polymer domes. It was found that the absorption and fluorescence spectra depend on the size of the polymer domes. Larger domes show red-shifted fluorescence spectra.
MOLECULE-UP FABRICATION AND MANIPULATION OF LIPID NANOTUBES
Authors: SHIMIZU TOSHIMI , JOHN GEORGE , FUKAGAWA AKIHIRO , ITO KOHZO , FRUSAWA HIROSHI
Published: September 2003

Self-assembling behavior of both a cardanol-appended glycolipid mixture and the fractionated four components has been examined in aqueous solutions. The cardanyl glucoside mixture differing in the degree of unsaturation in the hydrophobic chain was found to self-assemble in water to form open-ended nanotube structures with 10–15 nm inner diameters. The pure saturated homologue produced twisted helical ribbons through self-assembly, whereas the monoene derivative gave tubular structures. The rational control of helical and tubular morphologies has been achieved by a combinatorial approach through the binary self-assembly of the saturated and monoene derivatives. The flexural rigidity of a single lipid nanotube was first evaluated using optical tweezers manipulation and then compared with that of natural microtubules.
PREPARATION AND STABILITY OF THE NANOCHAINS CONSISTING OF COPPER NANOPARTICLES AND PVA NANOFIBER
Authors: WANG CE , LI ZHEN YU , LI DONGMEI , YANG QING BIAO , HONG YOULIANG
Published: September 2003

One-dimensional nanochains consisting of Cu nanoparticles and PVA nanofiber were prepared in the presence of a deoxidant NaHSO 3 by electrospinning. Their morphologies and stability were characterized by TEM and UV-vis spectra. The results show that three kinds of nanochains were formed according to the ratio of diameters of the nanoparticles to the nanofiber, i.e., Cu/PVA is equal to, larger, and smaller than 1. The nanochains are stable in air.
REMOVAL OF THE SURFACTANT SURROUNDING Ag NANOCLUSTERS SYNTHESIZED BY NEW THERMAL DECOMPOSITION METHOD
Authors: KEUN LEE DON , KANG YOUNG SOO
Published: September 2003

Silver nanoclusters have been formed by thermal decomposition of Ag-oleate complex. Transmission electron microscopic (TEM) images of the particles showed two-dimensional assembly of particles with diameter of 10.5 nm. Energy-dispersive X-ray (EDX) spectrum and X-ray diffraction (XRD) peaks of the nanoclusters showed the highly crystalline nature of the silver structures. The decomposition of silver-oleate complex was analyzed by Thermo Gravimetric Analyzer (TGA) and the crystallization process was observed by XRD. The removal of the surfactant surrounding silver nanoclusters was measured by FT-IR and SEM images.
SYNTHESIS OF THICK PORPHYRIN MOLECULAR WIRES BY A PALLADIUM CATALYZED OLIGOMERIZATION
Authors: OZAWA HIROAKI , OGAWA TAKUJI
Published: September 2003

In the aim to prepare thick porphyrin molecular wires, which is visible by atomic force microscopy (AFM), even on the rough surfaces of nanogap electrodes fabricated by electron beam lithography, dendrimer protected porphyrins whose two meso-positions are substituted with ethynyl groups. The porphyrin monomer was reacted with palladium catalyst to make oligomers. Analyses of them with time-of-flight mass spectroscopy (TOF-MS), gel-permeation-chromatography (GPC) revealed that the oligomers were distributed up to 16 mer, whose molecular weight was about 38 000 Daltons.
A STUDY ON A NEW SYNTHETIC METHOD OF CdS AND CdSe NANOPARTICLES AND THEIR ORGANIC/INORGANIC NANOCOMPOSITE
Authors: LEE JU YOUNG , KANG YOUNG SOO , KIM YONG JOO
Published: September 2003

Materials such as CdS and CdSe inorganic nanoparticles have photoluminescence. Sodium oleate has been used as effective stabilizers for the synthesis of CdS and CdSe nanoparticles in water by autoclave method. Photoluminescence of CdS and CdSe with particle size of 5–14 nm showed λ max at 520 nm and 600 nm, respectively, when were excited at 365 nm. These nanoparticles doped into the PVA resulted in the organic/inorganic films ( PVA/CdS , CdSe ). Photoluminescence, X-ray diffraction and transmission electron microscopy were employed for their characterization.
SYNTHESIS OF METAL AND METAL OXIDE NANOPARTICLES IN THE NANOSPACE OF ULTRATHIN TiO2-Gel FILMS: ROLE OF THE ION-EXCHANGE SITE
Authors: HE JUNHUI , ICHINOSE IZUMI , FUJIKAWA SHIGENORI , KUNITAKE TOYOKI
Published: September 2003

In this work, we showed that metal salts were easily deposited as aggregates (e.g., ultrathin planar microcrystals) on the surface of TiO 2- gel films in the absence of ion-exchange sites. In contrast, metal ions were efficiently incorporated into ultrathin TiO 2- gel films, when ion-exchange sites were created using Mg ( O - Et )2 as template. A variety of metal ions, including those of main group, transition, and lanthanide elements were successfully doped into TiO 2 thin films by the current approach. Probable distribution of the ion-exchange site in the film interior was discussed.
"PROTEOSILICA" A NOVEL NANOCOMPOSITE WITH PEPTIDE ASSEMBLIES IN SILICA NANOSPACE: PHOTOISOMERIZATION OF SPIROPYRAN DOPED IN CHIRAL ENVIRONMENT
Authors: ARIGA KATSUHIKO , AIMIYA TAKUJI , ZHANG QINGMIN , OKABE AKIHIRO , NIKI MAKIKO , AIDA TAKUZO
Published: September 2003

Mesoporous silica composites filling densely peptide assemblies (Proteosilica) were newly synthesized as transparent films. Spiropyran guest was co-doped in the films and photo-isomerization between spiropyran form and merocyanine form was repeated by alternate irradiation of visible and UV lights. Circular dichroism (CD) active spectra were observed only for the spiropyran form in the Proteosilica with hexagonal geometry. However, the CD active behavior was absent for the spiropyran in lamellar Proteosilica. Difference in peptide assembling structures would affect chiral sensitivity of the doped spiropyran guest.
PREPARATION AND PROPERTIES OF AlPdRe ICOSAHEDRAL QUASICRYSTALLINE THIN FILMS BY MOLECULAR BEAM EPITAXY
Authors: KIRIHARA KAZUHIRO , KAWAGUCHI KENJI , KOSHIZAKI NAOTO , KIMURA KAORU
Published: September 2003

We obtained thin films of the AlPdRe icosahedral quasicrystals by molecular beam epitaxy and post-annealing. The thickness of the films was estimated to be smaller than 100 nm. Any preferred orientation in the X-ray diffraction peaks was not observed in the films.
FABRICATIONS OF LUMINESCENT POLYMERIC NANOPARTICLES CONTAINING LANTHANIDE (III) ION COMPLEXES
Authors: TAMAKI KOICHI , SHIMOMURA MASATSUGU
Published: September 2003

Luminescent poly(ethylene glycol)-coated polystyrene (PSt) nanometer-sized particles (nanoparticles) containing trivalent europium or terbium ion were prepared by free-radical dispersion copolymerization of styrene, poly(ethylene glycol) (PEG) macromonomer, and the lanthanide complex which was coordinated with 1,10-phenanthroline possessing acryl group. Red and green luminescences with narrow band width were observed from each nanoparticle containing europium and terbium complexes, respectively.
PREPARATION AND CHARACTERIZATION OF SiO2 NANOPARTICLE AND MESOPOROUS SILICATE MOLECULAR SIEVE MCM-48
Authors: SEO KYUNG WON , MOON SUNG DU , KANG YOUNG SOO , KIM YONG JOO
Published: September 2003

Nanosize SiO 2 particles with narrow size distribution were produced by modified Stober–Fink–Bohn method. Average particle size was determined as 170 nm by SEM image. Organosilica mesoporous molecular sieve (MCM-48) was synthesized. The calcined MCM-48 has pore diameter of 26.8 Å and a surface area of 1024 m 2 g -1 by BET (Brunauer–Emmet–Teller) measurement.