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Na atualidade, há diferentes frentes de pesquisa (uso de novas estruturas de transistores, novos materiais, etc.) quer nas instituições de ensino, quer nos centros de pesquisa, visando a redução das dimensões do Transistor de Efeito de Campo Metal-Óxido-Semicondutor (MOSFET), para que, desta forma, possa continuar a atender a chamada Lei de Moore. Recentemente, foi proposta uma inovadora abordagem que não adiciona custos aos atuais processos de fabricação de circuitos integrados (CIs) MOS Complementar planares, chamada de MOSFET com leiaute de portas não convencionais, que são capazes de potencializar o seu desempenho elétrico em aplicações analógicas em relação ao MOSFET de geometria de porta retangular equivalente. Esta dissertação de mestrado visa realizar um estudo experimental comparativo do comportamento da distorção harmônica total normalizada pelo ganho de tensão (THD/Av) no MOSFET com leiaute de porta do tipo Diamante Híbrido (Composto pela associação paralela de 3 MOSFETs: ao centro um MOSFET do tipo Diamante e dois MOSFETs de porta retangular) em relação ao MOSFET convencional de geometria de porta retangular (CM), por se tratar de uma figura de mérito de grande importância em aplicações analógicas. O MOSFET do tipo Diamante Híbrido (HDM) foi desenvolvido devido às limitações do processo de fabricação de CIs mais sofisticados que não permitem que a região de porta seja definida de forma ortogonal à da região ativa do transistor. Os MOSFETs utilizados neste projeto de pesquisa foram fabricados com processo comercial de fabricação de CIs CMOS convencional (Bulk) de 0,18 µm da TSMC, via programa universitário Mini@sic do IMEC. O Método da Função Integral foi usado para realizar o estudo da THD/Av dos MOSFETs. Esse método usa somente a curva característica de corrente contínua do MOSFET operando na região de saturação (essa curva é a de corrente entre o dreno e a fonte em função da tensão entre a porta e a fonte). Um dos principais resultados obtidos mostra que o HDM com um ângulo alfa (a) igual a 45° é capaz de reduzir a THD/Av cerca de 6,4 dB para uma sobretensão de porta igual a 600 mV quando comparado ao CM, isso ocorre porque o MOSFET do tipo Diamante Híbrido com ângulo a igual a 45° apresentou um ganho de tensão intrísico maior que à do CM, visto que a THD/Av é fortemente dependente do ganho de tensão desses dispositivos Nowadays there are different researches fronts (use of new transistor structures, new materials, etc.) both in educational institutions and research centers, that aim to reduce the size of the Metal-Oxide-Semiconductor Field Effect Transistor (MOSFET), then to keep the socalled Moore Law. An innovative approach has been recently proposed that does not add additional costs to the current manufacturing processes of Planar Complementary MOS Integrated Circuits (ICs), called unconventional gate layout MOSFETs, which are able to enhance their electrical performance in analog applications over the equivalent rectangular gate geometry MOSFET. This master thesis aims to conduct a comparative experimental study of the behavior of the total harmonic distortion normalized by the voltage gain (THD/Av) in the Hybrid Diamond type gate layout MOSFET (Composed by the parallel association of 3 MOSFETs: in the center a MOSFET of Diamond type and two rectangular gate MOSFETs) compared to the conventional rectangular gate geometry MOSFET (CM), as it is a very important figure of merit in analog applications. Hybrid Diamond MOSFET (HDM) was developed due to the limitations of the manufacturing process of more sophisticated ICs that do not allow the gate region to be defined orthogonally to the active transistor region. The MOSFETs used in this research project were manufactured using commercial process TSMC's 0.18 µm CMOS Bulk via IMEC's Mini @ sic university program. The Integral Function Method was used to perform the THD/Av study of MOSFETs. This method uses only the direct current characteristic curve of the MOSFET operating in the saturation region (this curve is the current between the drain and the source as a function of the voltage between the gate and the source). One of the main results obtained by this research project shows that HDM with an alpha (a) angle of 45 ° is able to reduce THD/Av by about 6.4 dB for a gate overvoltage of 600 mV when Compared to CM, this is because the Hybrid Diamond MOSFET with angle a equal to 45 ° had a higher intrinsic voltage gain than CM, since THD/Av is strongly dependent on the voltage gain of these devices

To improve the reliability of electronic devices, electromigration (EM) in lead-free solders is actively being studied. In particular, EM testing methods that use 1-D stripe samples have significant merit. However, some aspects of the reasonability of the EM resistance evaluation remain to be discussed. In this study, the validity of the evaluation method utilising stripe-shaped samples without passivation was verified. Sn-3.0Ag-0.5Cu (SAC) and Sn-3.5Ag-0.5Cu-0.07Ni-0.01Ge (SACNG) solders (in wt.%) with a reference of four nine Sn were used as testing materials for the verification. EM resistance was evaluated by measuring the total volume of hillocks observed in the designated region per unit time of current supply. First, the effect of sample length on EM was confirmed by observing the hillock volume, which increased based on the sample length. In addition, EM resistance was ranked Sn < SAC < SACNG under a combination of experimental conditions as well as under another combination of the conditions. Therefore, the consistency of the EM resistance ranking regardless of the experimental conditions was shown through the experiment. Furthermore, an evaluation formula including the effects of sample length on the EM was derived. Finally, it was theoretically shown that the present method of EM resistance evaluation was consistent regardless of the experimental conditions. These experimental results and theoretical discussion demonstrated the validity of the presented evaluation method.

137Cs in seawater is one of the most powerful tracers of water motion. Large volumes of samples have been required for determination of 137Cs in seawater. This paper describes improvement of separation and purification processes of 137Cs in seawater, which includes purification of 137Cs using hexachloroplatinic acid in addition to ammonium phosphomolybdate (AMP) precipitation. As a result, we succeeded the 137Cs determination in seawater with a smaller sample volume of 10 liter by using ultra-low background gamma-spectrometry in the Ogoya underground facility. 137Cs detection limit was about 0.1 mBq (counting time: 106 s). This method is applied to determine 137Cs in small samples of the South Pacific deep waters. © 2008 Springer Science+Business Media, LLC.

Almost pure Z-type phases of hexaferrites were synthesized by firing preliminarily milled M- and Y-type phases intermediates at 1250 °C. These phases were obtained by calcining the stoichiometric powder mixture precursors at 1080 °C, followed by wet milling in a planetary mill for 1 h and subsequent heating at 1250 °C that increased the fractional crystallization of the Z-phase up to 96%. Addition of 0.2 wt% SiO 2 to the intermediates reduced the milling time necessary for the sintered density required for practical permeability measurement. Z-phase hexaferrite sintered at 1250 °C for 2 h exhibited fairly good high-frequency properties, i.e. an initial real permeability of up to 19.3 below 100 MHz and 8–10 at around 1 GHz.

A fully coherent free electron laser (FEL) seeded with a higher-order harmonic (HH) pulse from high-order harmonic generation (HHG) is successfully operated for a sufficiently prolonged time in pilot user experiments by using a timing drift feedback. For HHG-seeded FELs, the seeding laser pulses have to be synchronized with electron bunches. Despite seeded FELs being non-chaotic light sources in principle, external laser-seeded FELs are often unstable in practice because of a timing jitter and a drift between the seeding laser pulses and the accelerated electron bunches. Accordingly, we constructed a relative arrival-timing monitor based on non-invasive electro-optic sampling (EOS). The EOS monitor made uninterrupted shot-to-shot monitoring possible even during the seeded FEL operation. The EOS system was then used for arrival-timing feedback with an adjustability of 100 fs for continual operation of the HHG-seeded FEL. Using the EOS-based beam drift controlling system, the HHG-seeded FEL was operated over half a day with an effective hit rate of 20%–30%. The output pulse energy was $20~{\rm\mu}\text{J}$ at the 61.2 nm wavelength. Towards seeded FELs in the water window region, we investigated our upgrade plan to seed high-power FELs with HH photon energy of 30–100 eV and lase at shorter wavelengths of up to 2 nm through high-gain harmonic generation (HGHG) at the energy-upgraded SPring-8 Compact SASE Source (SCSS) accelerator. We studied a benefit as well as the feasibility of the next HHG-seeded FEL machine with single-stage HGHG with tunability of a lasing wavelength.

M-type hexagonal ferrite precursor was prepared by a soft mechanochemical treatment of BaCO3 and α-FeOOH mixtures. The effect of milling on its structure and thermal behaviour was examined by XRD, SEM and FTIR. Well crystallizedM-type hexagonal ferrite was formed from just 1 h milled precursors at 800°C. The beneficial effect of milling was explained in terms of increased homogeneity with simultaneous hetero bridging bond formation between powder constituents.

Z-type hexaferrites (Ba3(1 − x)Sr3x Co2Fe24O41with x = 0–0.5, Z-hex) were prepared in a nearly phase pure state by a two-step calcination with an intermediate wet milling. The first calcination of the starting mixture comprising oxides or hydroxides at temperatures below 1100∘C brought about a mixture of layer-structured M and Y-type hexaferrite phases, together with a spinel phase of Co ferrite. Z-hex was fully crystallized after the second calcination up to 1230∘C. Wet milling between the two calcination steps was decisive for the phase purity. Emphasis was laid on the quantitative analyses of Z-hex, together with the evaluation of anisotropic growth of the crystallites. Sr addition stabilizes Z-hex, while decreases degree of anisotropy simultaneously.

A comparative study on the wet and dry milling of the intermediates for the Z-type hexagonal ferrite (Ba3Co2Fe24O41, Z phase) was performed. Phase-pure Z phase was synthesized by wet milling the intermediates comprising M and Y-type hexaferrites. The intermediates were obtained by calcining the stoichiometric powder mixture at 1080 °C. Subsequent wet milling by a planetary mill for 1 h increased the crystallization rate of Z phase upon subsequent heating at 1230 °C. In contrast, dry milling the intermediates resulted in the severe surface amorphization and led to heterogeneous crystalline states. The observed favorable effect of wet milling the intermediates was explained by the particle size reduction for the decrease of diffusion distance while preserving the basic layer units common to the related hexaferrites.

The feasibility study of Melt Refining Decontamination by Slagging (MRDS) havs been performed for the release and recycling of Low Level Radioactive Metal Waste (LLRMW) contaminated with uranium discharged from nuclear fuel cycle facilities. Experiments and their evaluation have been performed for the decontamination performance of the waste containing aluminum and have clarified the followings. Simulated waste was decontaminated to 0.01 Bq/g when the addition of aluminum is below 1.5 wt% in laboratory scale test equipment. This was demonstrated also in the engineering scale experiment for MRDS. These results demonstrate that the MRDS is an effective processing technology for low level radioactive metal waste with uranium.

The ability of Japanese cedar (Cryptomeria japonica) bark to remove Cr(VI) from aqueous solutions was investigated. The research parameters included the solution pH, temperature, and initial concentration of Cr(VI) in solution. The removal of Cr(VI) was highly solution pH dependent and adsorbate concentration dependent, and mainly governed by physicochemical adsorption under the weak acidic conditions studied (initial solution pH ≥ 3). However, the reduction of Cr(VI) to Cr(III) occurred extensively at low solution pH (initial solution pH ≤ 2). The equilibrium data at different temperatures fit well in the Langmuir isotherm model. The endothermic nature of the adsorption was confirmed by the positive value of enthalpy change (18.9 kJ mol−1). The positive value of entropy change (65.2 J mol−1 K−1) suggested the increased randomness at the solid–solution interface during the adsorption. The studies showed that Japanese cedar bark can be used as a cost‐effective adsorbent for the removal of Cr(VI) f...

In the tandem mirror GAMMA 10, a gold neutral beam probe (GNBP) has been developed to measure the local electrostatic potential and electric field of the central plasma. The potentials at two point...

Y-type (Ba2Co2Fe12O22) hexaferrite precursors have been prepared via a soft mechanochemical route from mixtures comprising BaCO3, Co(OH)2 and α-FeOOH. The mixture was activated with a multi-ring type mill for varying duration. The chemical and structural changes during grinding were examined in detail by XRD, DTA-TG, SEM, XPS and FTIR. During grinding, extended crystallinity loss or lattice disturbance was observed without an emersion of any new crystalline phases. At the same time, electronic states were changed toward the final product, fully crystallized Y-phase ferrite. Mechanical activation for only 1 h was sufficient to obtain a precursor for phase pure Y-type by subsequent heating in air at temperatures as low as 1000 °C. Development of plate-like anisotropy by using a precursor with prolonged milling was also observed. Magnetic permeability, μ′, was ca. 3 at 1 GHz, equivalent to the reported data, in spite of the lower firing temperature.

The present study examined the effects of heat treatment and the addition of Cu-Ni alloy on the corrosion resistance of the matrix of spheroidal graphite cast iron in aqueous environments. Test materials of white cast iron and carbon steel were used for comparison with spheroidal graphite cast iron. The alloy spheroidal graphite cast iron that added Cu and Ni was prepared. The spheroidal graphite cast iron was subjected to three kinds of heat treatment to adjust the matrix: annealing, oil quenching, and austemper heat treatment. In electrochemical tests, measurements of corrosion electrode potential and cathode and anode polarization were used. The following was clarified from the relationship between the electrode potential and current density of each of the materials in each of the solution. The alloy spheroidal graphite cast iron had a high corrosion electrode potential owing to the addition of Cu-Ni, and tended to have a low corrosion current density. This demonstrates that in any of the materials having a matrix adjusted by heat treatment, the addition of Cu-Ni increased the corrosion resistance. The corrosion current density was highest in a sulfuric acid environment.

Spectroscopic ellipsometry, reflectometry and magnetooptical (MO) spectroscopy in the zero and first diffraction orders are used to analyze submicron ultrathin MO gratings. Two different theoretical approaches, a rigorous analysis and an approximate method, are used to simulate the optical and MO response of the gratings. The numerical analysis suggests the presence of native oxide layers on the substrate and capping. A strong spectral anomaly observed in the MO response is identified by the integration of both theoretical approaches. The possibility to monitor the quality and topography of shallow gratings with high sensitivity is concluded.

Submitted by Guilherme Lemeszenski (guilherme@nead.unesp.br) on 2013-08-22T18:52:21Z No. of bitstreams: 1 S0100-84042003000400005.pdf: 854373 bytes, checksum: e07b0de7af93c8a707049440a4e682c7 (MD5) Made available in DSpace on 2013-08-22T18:52:21Z (GMT). No. of bitstreams: 1 S0100-84042003000400005.pdf: 854373 bytes, checksum: e07b0de7af93c8a707049440a4e682c7 (MD5) Previous issue date: 2003-12-01 Made available in DSpace on 2013-09-30T19:43:27Z (GMT). No. of bitstreams: 2 S0100-84042003000400005.pdf: 854373 bytes, checksum: e07b0de7af93c8a707049440a4e682c7 (MD5) S0100-84042003000400005.pdf.txt: 38373 bytes, checksum: 5696766467b39b9f6f038110130a4bcd (MD5) Previous issue date: 2003-12-01 Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-20T13:56:49Z No. of bitstreams: 2 S0100-84042003000400005.pdf: 854373 bytes, checksum: e07b0de7af93c8a707049440a4e682c7 (MD5) S0100-84042003000400005.pdf.txt: 38373 bytes, checksum: 5696766467b39b9f6f038110130a4bcd (MD5) Made available in DSpace on 2014-05-20T13:56:49Z (GMT). No. of bitstreams: 2 S0100-84042003000400005.pdf: 854373 bytes, checksum: e07b0de7af93c8a707049440a4e682c7 (MD5) S0100-84042003000400005.pdf.txt: 38373 bytes, checksum: 5696766467b39b9f6f038110130a4bcd (MD5) Previous issue date: 2003-12-01 Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Com o objetivo de colaborar na delimitação taxonômica de Aechmea, subgênero Lamprococcus, foram estudadas as folhas de 25 táxons morfologicamente relacionados entre si (13 de Aechmea, três de Ronnbergia E. Morren & André, quatro de Araeococcus Brongn. e cinco de Lymania Read). Apesar das folhas serem todas hipoestomáticas e possuírem mesofilo dorsiventral portador de hipoderme, elas exibem características que podem ser utilizadas na delimitação de cada representante. Essas características incluem: posição dos estômatos na superfície foliar, presença ou não de oclusão nas câmaras subestomáticas, ocorrência ou não de grupos de fibras dispersos no mesofilo, natureza da parede das células que compõem as bainhas e extensões dos feixes vasculares e morfologia das células dos diafragmas, que interrompem os canais de aeração. A distribuição desses caracteres, nos diferentes táxons, permitiu elaborar uma chave de identificação, com base apenas na estrutura foliar. With the aim of recognising useful features for taxonomic purposes, we studied the leaf anatomy of 25 taxa that are morphologically related (13 of Aechmea subgenus Lamprococcus, three of Ronnbergia E. Morren & André, four of Araeococcus Brongn. and five of Lymania Read). Although all leaves are hypostomatic and have a dorsiventral mesophyll with a hypodermis, they show some features that characterise each species. These features include, the stomata position on leaf surface, the presence or absence of substomatic occlusions, the occurrence or not of fibre clusters in the mesophyll, the nature of the cell walls of the vascular bundle sheaths and the cell morphology of the diaphragm that interrupt the air channels. By associating these characters we have elaborated an identification key for the studied taxa, based on the leaf structure. Universidade Estadual Paulista Departamento de Botânica Universidade Estadual Paulista Departamento de Botânica

The temporal variation of water column inventories of 137Cs in the North Pacific since the 1960s was examined based on the analysis of the 137Cs profiles in HAM database. 137Cs in seawater in the North Pacific have originated mainly from global fallout from atmospheric nuclear weapons tests, which occurred in the early 1960s. In the 1960s, both the meridional distribution of 137Cs inventory in the North Pacific and that of fallout on land stations showed mid-latitude maximum. The region with higher deposition at land stations, however, was more northern than the latitudes where the 137Cs inventory in the North Pacific showed a maximum. The difference of the latitude where maximum 137Cs deposition/inventory was observed reflects the difference of the geographical distribution of the precipitation amount in the Pacific and Atlantic Oceans followed by the different warm current systems in each ocean. A good positive relation between 137Cs inventory and annual precipitation amount was discovered in the ocean stations at the middle latitude in the North Pacific. The horizontal distribution of 137Cs inventories at the middle latitudes in the North Pacific is characterized as west-high and east-low in the early 1960s, which was basically controlled by the distribution of annual precipitation amount. Eastward advection, then, modified it to be less difference in 1966–1967 after the highest deposition periods in 1963–1965. In the 1970s and 1980s, increases of the 137Cs inventory at the lower latitude of 10–20 deg. N are found. Surface and subsurface southward transports are considered as the source of this increasing 137Cs inventory.

An efficient Escherichia coli expression system was constructed for the production of a variant form of HNF1 protein having the additional five amino acid residues (Asp-Arg-Trp-Gly-Ser) at the NH2-terminal. The cDNA encoding HNF1 was ligated to 6×His tag and inserted into an inducible bacterial expression vector pRSET A. After expression in E. coli, the recombinant product was purified by Ni-NTA affinity column chromatography. The purified product showed expected NH2-terminal sequence and specific binding to the HNF1 site. The effect of pyridoxal 5′-phosphate and its analogues on the binding activity of recombinant HNF1 was examined and found that only pyridoxal 5′-phosphate effectively inhibited the DNA binding. The concentration of pyridoxal 5′-phosphate that inhibited 50% of DNA binding was around 100 μM. Furthermore, we identified Lys197 of HNF1 molecule as the essential residue of DNA binding. These observations suggest that pyridoxal 5′-phosphate directly interacts with tissue-specific transcription factor HNF1 and modulates the binding to DNA.

Anomalies, which we have recently discovered at x =0.21 in La 2− x Sr x Cu 1− y Zn y O 4 single crystals, are reviewed. In the 1% Zn-substituted crystal with x =0.21, the resistivity exhibits an upturn at low temperatures below about 80 K and the superconductivity (SC) is markedly suppressed. The muon-spin-relaxation ( μ SR) measurements have revealed the existence of a static ordered state of Cu spins in this crystal at low temperatures below 2 K. From the elastic neutron-scattering experiment, incommensurate magnetic peaks around ( π , π ) have been observed in this crystal at low temperatures below 20 K. Even in the Zn-free crystal with x =0.21, the SC is a little suppressed and the magnetic correlation has been found from the μ SR measurements to be enhanced at low temperatures below about 0.8 K. These results strongly suggest that the dynamical stripe correlations of spins and holes tend to become static singularly at x =0.21 and are pinned by a small amount of Zn at x =0.21, leading to the static stripe-order and the marked suppression of SC, as in the case of x =0.115.

The ability of larch (Larix leptolepis Gold.) bark to remove Cr(VI) from dilute aqueous solutions was investigated. The research parameters included the solution pH, contact time, temperature and initial concentration of Cr(VI) in solution. Of the parameters studied, the solution pH was found to be the most crucial. The Cr(VI) removal decreased steadily throughout the pH range studied (pH 2–6), while the Cr adsorption peaked at pH 3. Because the chemical reduction of Cr(VI) to trivalent state occurred to lesser extents even in strong acidic media, the Cr(VI) removal was mainly governed by physico-chemical adsorption. The positive value of the heat adsorption (ΔH 0) indicates the endothermic nature of the Cr(VI) adsorption. The relatively slow rate and irreversible nature of the adsorption as well as the order of the magnitude of the heat adsorption value suggest that the adsorption is of a chemical type. The adsorption data obtained from the equilibrium experiments were well fitted to both the Langmuir and Freundlich isotherms.

Effects of the Cu-site substitution on the 1/8 anomaly in the Bi-2212 and Y-123 phases and also on the anomaly at x = 0.21 in La 2-x Sr x CuO 4 (LSCO) have been investigated from the transport, muon-spin relaxation and neutron-scattering measurements. It is suggested that the dynamical stripe correlations of spins and holes exist in the Bi-2212 and Y-123 phases as well as in the La-214 phase and that they tend to be pinned by Zn at the hole concentration of ∼1/8 per Cu in the high-T c cuprates and also at x = 0.21 in LSCO. Based upon the stripe-pinning model, universal properties in the high-T c cuprates that partially substituted Zn is a strong scatterer and that the Zn substitution markedly suppresses the superconductivity are also discussed.

Our recent experimental studies on the 1/8 anomaly in the Bi-2212 and Y-123 phases and on the new anomaly at x=0.21 in La2−xSrxCu1−yZnyO4 are reviewed. In the Zn-substituted Bi-2212 and Y-123 phases, we have found anomalous suppression of superconductivity at p (the hole concentration per Cu in the CuO2 plane) ∼1/8, and it has been found from the muon spin relaxation (μ SR) measurements that the magnetic correlation between Cu spins is enhanced singularly at p∼1/8. Furthermore, we have found marked suppression of superconductivity singularly at x=0.21 in the 1% Zn-substituted single-crystals of La2−xSrxCu1−yZnyO4, and it has been found from the μ SR measurements that the magnetic correlation is also enhanced at x=0.21. These results suggest that the dynamical stripe correlations of holes and spins exist in the Bi-2212 and Y-123 phases as well as in the La-214 phase and that they tend to be pinned by Zn, leading to the suppression of superconductivity. If this tendency is the case in a wide range of p, it ...

Our recent experimental studies on the so-called 1/8 anomaly in the Bi-2212 and Y-123 phases and also on the new anomaly in the overdoped region of the La-214 phase are reviewed. In the partially Zn-substituted Bi-2212 and Y-123 phases, we have found anomalous suppression of superconductivity (SC) at p (the hole concentration per Cu in the CuO 2 plane) ~1/8, and it has been found from the muon-spin-relaxation (μSR) measurements that the magnetic correlation between Cu spins is enhanced singularly at p~1/8. Furthermore, we have found giant suppression of SC singularly at x=0.21 in the 1% Zn-substituted single-crystals of La 2-x Sr x Cu 1-y Zn yO4 (LSCZO), and it has been found from the μSR measurements that the magnetic correlation is also enhanced at x=0.21. These results suggest that the dynamical stripe correlations of holes and spins exist in the Bi-2212 and Y-123 phases as well as in the La-214 phase and that they tend to be pinned by a small amount of Zn, leading to quasi-static stripe order and the suppression of SC at p~1/8 in the Bi-2212, Y-123, La-214 phases and also at x=0.21 in LSCZO. If this tendency is the case in a wide range of p, it is possible to understand the universal experimental results in the high-Tc cuprates that Zn is a strong scatterer in the unitarity limit and that the Zn substitution markedly suppresses SC.

Static and dynamical properties of Cu spins in the overdoped single-crystals of La 2-x Sr x Cu 1-y Zn y O 4 have been investigated by the muon-spin-relaxation (μSR) method. In the Zn-substituted single-crystal with x=0.21 and y=0.01, where the high-T c superconductivity is anomalously suppressed, a coexisting state of statically ordered Cu-spins and localized holes has been found at low temperatures below about 2 K. The dynamical depolarization rate of the muon spin at 3.0 K has been found to be nearly proportional to minus-root-square of the external magnetic-field applied along the initial muon-spin polarization. This field-dependence can be explained by assuming the existence of an excited state of the Cu spins diffusing in a one-dimensional direction. The present study suggests a high possibility of the existence of a new one-dimensional stripe ordered state of the Cu spins and doped holes at x=0.21 in the overdoped region of La 2-x Sr x Cu 1-y Zn y O 4.

The ability of carbonized waste newsprint fiber to remove Hg(II) from aqueous solutions by physicochemical adsorption was investigated. Defiberized waste newsprint was carbonized in a nitrogen atmosphere at temperatures ranging 600 to 900°C for 3 h. Research parameters included carbonization temperature, initial solution pH, contact time, solution temperature, and initial concentration of Hg(II). The studies showed the adsorbents to be an efficient adsorbent for removing Hg(II) from aqueous solutions. Of the parameters studied, carbonization temperature and initial solution pH were considered to be the most crucial. The amount of Hg(II) adsorbed onto the adsorbent increased with increasing carbonization temperature in the pH range 3 to 9, while it decreased as the temperature increased at pH 11. The extent of the adsorption was also dependent upon the contact time, solution temperature, and initial concentration of Hg(II). The adsorption data were well fitted to both the Freundlich and Langmuir isotherms....

Soil microbial biomass and microbial products play an important role in the stabilization of soil structure and, in turn, as a feedback, structure is believed to be a significant control of C dynamics in soils. We investigated the microbial mineralization and assimilation of added 13 C-[U]-glucose within macro- and microaggregates from surface soils (Humic Gleysol) obtained from long-term plots amended or not with cattle manure (20 Mg ha −1 yr −1 for 18 yr). Slaking-resistant macroaggregates (250–1000 μm) and microaggregates (53–250 μm) were separated by wet sieving and incubated with 13 C-labeled glucose (1000 μg C g −1 soil) and (NH 4 )SO 4 (67 μg N g −1 soil) for 14 d at 25°C following a 7-d period of conditioning at 25°C. The production of 13 C-labeled CO 2 was measured periodically and the chloroform-labile C (microbial biomass) derived from glucose was determined at the end of the 14-d incubation. The added glucose was mineralized less but assimilated more in the microbial biomass of macroaggregates than in microaggregates, and this effect was generally greater in the manure-amended soil. Overall, the percentage of 13 C-labeled glucose assimilated was inversely correlated ( r =0.59) with that mineralized during the 14-d incubation. The size of the native biomass 14 d after glucose addition followed the same trend as that of the glucose-derived biomass. Our results support the hypothesis that stable macroaggregates, especially those from manured-soil, support a greater microbial biomass than microaggregates and constitute ‘hot-spots’ for the metabolism of readily-available substrates.

Effects of long-term (18-yr) applications of cattle manure (20 Mg ha−1 yr−1) and NPK fertilizer on the labile organic matter (OM) and its protection in water-stable aggregates were investigated in a Le Bras silt loam (Humic Gleysol). Soil from the 0- to 10-cm depth was sampled from the untreated control, NPK, manure and NPK + manure treatments and fractionated into four size classes of slaking-resistant aggregates (>1000 µm, 250–1000 µm, 53–250 µm, 1000 µm) and intact microaggregates (

Culms of bamboo grass ( Sasa senanensis Rehd.) were treated with saturated steam at a range of temperatures between 170 and 197°C for 10 min in the presence of various acid catalysts in order to improve solubilization of the xylan in the substrate. The catalysts were Lewis acids, inorganic salts and organic acids. These compounds strongly modified the steam-hydrolysis and solubilization of bamboo grass xylan. The use of low levels of Lewis acids or CaCl 2 had the advantage of a substantial reduction in temperature requirement for the steaming treatment. The solubilized sugars were mainly composed of xylose, arabinose and low molecular weight xylo-oligosaccharides.

Summary The ability of coniferous leaves to remove Cr(VI) from dilute aqueous solutions by physico-chemical adsorption and chemical reduction was investigated. Of 30 coniferous tree species tested, relatively high removal ability was found in Ginkgo, Larix, Pinus, Cryptomeria, Metasequoia, Taxodium, Thuja and Thujopsis spp. To search for optimum operation condition for treatment of wastewater containing Cr(VI), factors affecting Cr(VI) removal were studied using P. densiflora leaves. The extent of the removal was dependent upon the initial solution pH, contact time, temperature and initial concentration of Cr(VI) in solution. The Cr(VI) removal was mainly governed by the physico-chemical adsorption onto the substrate. The adsorption data were well fitted to the Freundlich isotherm.

Application of cattle manure generally improves soil structure and organic matter (OM) content. However, changes in forms and location of OM within the aggregate structure are less well known. The effects of long-term (18-yr) applications of cattle manure (20 Mg ha–1 yr−1) and NPK fertilizer on the distribution of particulate and mineral-associated organic matter in water-stable aggregates were investigated in a Le Bras loam (Humic Gleysol). Soil samples from the 0- to 10-cm depth were taken from the untreated control, NPK, manure and NPK + manure treatments. They were separated into four aggregate-size fractions (>1000 µm, 250–1000 µm, 53–250 µm, and 53 µm) and mineral-associated OM (53 µm by sieving after mechanical dispersion. After 18 yr, manure increased the OM level of the whole soil and favored formation of slaking-resistant macroaggregates (250–1000 µm). This effect was primarily a result of the OM added by the manure. In contrast, NPK fertilizer did not affect soil OM level or macroaggregation. The increase in OM induced by manure application was observed primarily in macroaggregates, and both as mineral-associated and particulate OM. However, manure did not change OM located in the fraction

Transport and Tcanomalies around x=0.22 in La2−xSrxCuO4have been studied through the partial substitution of Zn, Ga and Ni for Cu. It has been found that the value of x where the anomalies occur shifts to lower x values through the Zn substitution, while it shifts to larger x values through the Ga substitution, and it disappears through the Ni substitution. There is a possibility that an order of holes and/or spins, such as the so-called stripe order, is formed or fluctuates around x=0.22 in La2−xSrxCuO4.

Charge damage occurring when via contact hole is exposed in sputter etch pre-cleaning process using Ar gas plasma prior to metal deposition was studied. MOS capacitors with two types of antenna structures were prepared to study this damage, one type is the expose antenna used to examine damage caused by non-uniform plasma and the other is the via hole antenna used to examine electron shading damage. No damage is detected in MOS capacitors having the expose antenna structure, whereas the damage is observed in the via hole antenna structure. This damage depends on the number of via holes and their aspect ratios. As a result of this study we found the damage by pre-clean plasma is caused by electron shading effects.

Three lignin model compounds of β-O-4 type, guaiacylglycerol-β-guaiacyl ether (1), guaiacylglycerol-β-(4-methylguaiacyl) ether (2) and veratrylglycerol-β-guaiacyl ether (3) were heated with dioxane-water mixture (1:1, v/v) at 180°C for 20 min in the absence of and in the presence of holocellulose. The reaction mixtures were analyzed with high performance liquid chromatography (HPLC). Compound (1) gave coniferyl alcohol (4), guaiacol (5), 1,2-diguaiacyl-propane-1,3-diol (7), dehydrodiconiferyl alcohol (8), DL-pinoresinol (9) and a trilignol (10) in the absence of holocellulose. Compound (2) gave (4), 4-methylguaiacol (6), (8), (9) and an unidentified compound (11) under the same reaction conditions. In contrast, the nonphenolic β-O-4 model compound (3) did not undergo both degradation and radical recombination on the treatment with the dioxane-water mixture under the same reaction conditions. After the treatment, the starting material was recovered almost quantitatively. Consequently, the reaction products (7), (8), (9) and (10) must be produced by recombination among the radical species derived from a homolytic cleavage of the phenolic β-O-4 linkage in (1) and (2). These results imply that the cleavage of phenolic β-O-4 linkages proceeds through the formation of quinone-methide intermediate on the treatment with dioxane-water at elevated temperature. When these model compounds were treated in the presence of holocellulose under the same reaction conditions, none of the secondary products (8), (9) and (10) were detected in the reaction mixtures, except (7) in only a trace amount. These results indicate that the carbohydrates act as hydrogen atom donor, reducing the radical species before the occurrence of radical recombinations.

The abilities of 15 coniferous barks for removing toxic heavy metal ions were investigated. The barks considerably varied in the adsorption ability to each metal ion. Of the barks tested, high adsorption ability for heavy metal ions was found inPicea abies (Norway spruce). Equilibrium experiments usingP. jezoensis (Yezo spruce) bark showed that the adsorption of Cd2+ was greatly affected by the pH of solution and the initial Cd2+ concentration in solution. The adsorption of Cd2+ byP. jezoensis bark followed Freundlich isotherm in the concentration range 10–330 mg Cd2+/L. The continuous column experiments usingP. jezoensis bark indicated that the packing had retained 10.1–14.2 mg Cd2+/g adsorbent until the column broke through.

The acetone extract of the bark ofMagnolia obovata Thunb. had potent antifungal activity against plant pathogenic and wood destroying fungi. The active principles were isolated and identified to be eudesmols (I), magnolol (II) and honokiol (III). Eudesmols, which are main components of the volatile bark oil, showed strong antifungal activity against all of the fungi tested, especially basidiomycetes. It completely inhibited the growths ofCoriolus versicolor, Lepista sordida, Pycnoporus coccineus, Rhizoctonia solani, Serpula lacrymans andTyphula ishikariensis at a concentration of 500 μg mL−1. Two biphenyl type neolignans, magnolol and honokiol, also exhibited potent antifungal activity against these fungi except againstC. versicolor andL. sordida. They completely depressed the growths ofS. lacrymans andT. ishikariensis at the same concentration.