Search

Molecular dynamics simulations of linear C78H158 were conducted to investigate the dynamics of individual chains under shear. The distribution of the end-to-end vector exhibited Gaussian behavior at low shear rates; however, it displayed a bimodal form at high shear rates as rotational motion of the individual chains effectively lowered the vector's magnitude. Correlations between the components of the end-to-end vector revealed multiple time scales associated with the fluid response: the Rouse time, and several that were associated with the deformation and rotational dynamics of the fluid.

A new rheocasting process was applied to develop a diesel engine block using ADC10 alloy. This type of diesel engine block requires much higher mechanical properties for a high engine power, and this is why heat treatment for improving mechanical properties should accompany processing. Therefore, the manufacturing process for a diesel engine block must prevent inner defects such as blow-holes, gas porosities and shrinkages. Rheocasting is considered as a manufacturing technique for this purpose. In order to apply the rheocasting technique in manufacturing a diesel engine block, it is important to produce large-volume slurry. Establishing the injection condition has been particularly focused on for the integral inner parts. The Advanced Rheocasting Technology (ART) system, in this study, was used for large-volume slurry with ADC10 alloy. Through computer simulation, the injection condition was determined to stabilize feeding patterns which were verified from experimental results. Various heat treatments were tested to determine the optimal condition for the rheocast diesel engine block. The rheocast engine block showed fine and uniform microstructures, where the average diameter of primary α-globules was 75 μm and its form-factor indicating the degree of globularity was 0.83 including gas contents below 4cc/100 g Al. Mechanical properties indicated 317 MPa Ultimate Tensile Strength (UTS) and 1.2% elongation good enough for the objective usage after modified T6 heat treatment.

Surface morphology of the screen-printed activated carbon paste with organophobic montmorillonite clay and electron field emission properties was studied. X-ray diffraction (XRD), and scanning electron microscopy (SEM) were used to evaluate the distribution of filler in the carbon paste and the structure of carbon film. The addition of clay particles improved homogeneous dispersion of carbon in paste, which contributed to the formation of uniform carbon film during screen-printing. The current density J increased significantly, while the threshold electric field E th decreased when the filler particles were added to the carbon paste. The enhancement of field emission properties is believed to be due to the improvement of the dispersivity and adhesiveness of the paste. The organoclay loading also showed better thermal stability.

We have performed nonequilibrium molecular dynamic simulations of the linear short-chain polyethylene liquids C 24 H 50 , C 50 H 102 , C 78 H 158 , and C 128 H 258 under homogenous shear and elongational flows. We present visualizations of the molecular structure of each of the four liquids under shear and elongation, and compare them with their equilibrium static structures. These graphics provide a structural understanding of the various statistical measures that have been used in the literature to characterize the change in chain conformation as a function of strain rate and chain length. Moreover, these graphics allow a visualization of the inherent chain dynamics and orientation induced by shear and elongational flows. We discuss the molecular-level mechanisms apparent in the graphics.

The structural, energetic and rheological properties of seven short-chain perfluoropolyethers (PFPEs) under planar Couette flow have been investigated through nonequilibrium molecular dynamics (NEMD) simulation. The full parameter set of a revised universal force field (A.K. Rappe et al., UFF, a full periodic table force field for molecular mechanics and molecular dynamics simulations, J. Am. Chem. Soc. 114 (1992), p. 10024) is presented for linear PFPEs, allowing for multiple types of fluorine atoms depending upon their local environment (B. Jiang et al., Comparison of rheological properties of short-chain PFPEs through simulation and experiment. Mol. Simul. 33 (2007), p. 871). The NEMD simulations quantitatively reproduce experimental zero-shear-rate viscosities for five PFPEs with varying molecular architectures. Rheological properties and structural variations of PFPEs are investigated as functions of flow strength, temperature and chain architecture. We find the following general relationships betwee...

This paper presents the dynamic infinite element formulations that have been developed for soil-structure interaction analysis both in frequency domain and time domain by the present authors and our colleagues during the past 20 years. Axisymmetric, 2D and 3D layered half-space soil media were considered in the developments. The displacement shape functions of the infinite elements were established using approximate expressions of analytical solutions in frequency domain to represent the characteristics of multiple waves propagating into the unbounded outer domain of the media. The shape functions were determined in terms of the excitation frequency as well as the spatial and material characteristics of the far-field soil region. Thereby the element mass and stiffness matrices are frequency dependent. As for time domain analysis, the shape functions were further simplified to obtain closed-form frequency-dependent mass and stiffness matrices, which can analytically be transformed into time domain terms by the Fourier transform. The proposed infinite elements were verified using benchmark examples, which showed that the present formulations are very effective for the soil-structure interaction analysis either in frequency or in time domain. Example applications to actual soil-structure interaction problems are also given to demonstrate the capability and versatility of the present methodology.

This paper presents wrinkled microparticles as unreplicable, unique, yet configurable microtaggants for anti-counterfeiting purposes. We mimicked the shape of the human fingerprint in microscale structures using three-dimensional wrinkle patterning. We utilized irreproducible distributions of ridges on wrinkled microparticles as unique codes, similar to human fingerprints, for identification. These wrinkled microparticles can provide reliable authentication by attaching to authentic products because they can be analyzed by general fingerprint-identification methods, exhibit high individuality, and allow mass production by combining lithography-free patterning with a particle-based substrate.

The current study was carried out to define the involvement of Peroxiredoxin (Prx) II in progression of hepatocellular carcinoma (HCC) and the underlying molecular mechanism(s). Expression and function of Prx II in HCC was determined using H-ras(G12V)-transformed HCC cells (H-ras(G12V)-HCC cells) and the tumor livers from H-ras(G12V)-transgenic (Tg) mice and HCC patients. Prx II was upregulated in H-ras(G12V)-HCC cells and H-ras(G12V)-Tg mouse tumor livers, the expression pattern of which highly similar to that of forkhead Box M1 (FoxM1). Moreover, either knockdown of FoxM1 or site-directed mutagenesis of FoxM1-binding site of Prx II promoter significantly reduced Prx II levels in H-ras(G12V)-HCC cells, indicating FoxM1 as a direct transcription factor of Prx II in HCC. Interestingly, the null mutation of Prx II markedly decreased the number and size of tumors in H-ras(G12V)-Tg livers. Consistent with this, knockdown of Prx II in H-ras(G12V)-HCC cells reduced the expression of cyclin D1, cell proliferation, anchorage-independent growth and tumor formation in athymic nude mice, whereas overexpression of Prx II increased or aggravated the tumor phenotypes. Importantly, the expression of Prx II was correlated with that of FoxM1 in HCC patients. The activation of extracellular signal-related kinase (ERK) pathway and the expression of FoxM1 and cyclin D1 were highly dependent on Prx II in H-ras(G12V)-HCC cells and H-ras(G12V)-Tg livers. Prx II is FoxM1-dependently-expressed antioxidant in HCC and function as an enhancer of Ras(G12V) oncogenic potential in hepatic tumorigenesis through activation of ERK/FoxM1/cyclin D1 cascade.

The present study investigates the effects of Yukmijihwang-tang Derivatives (YMJd) on learning and memory through the Morris water maze task and the central cholinergic system of rats with excitotoxic medial septum (MS) lesion. In the water maze test, the animals were trained to find a platform in a fixed position for 6 d and then received a 60-s probe trial in which the platform was removed from the pool on the 7th day. Ibotenic lesion of the MS showed the impaired performance in the Morris water maze test and severe cell losses in the MS, as indicated by decreased choline acetyltransferase-immunoreactivity in the medial septum. Daily administrations of YMJd (100 mg/kg, i.p.) for 21 consecutive days produced significant reversals of ibotenic acid-induced deficit in learning and memory. These treatments also reduced the loss of choline acetyltransferase (ChAT) immunoreactivity in the MS induced by ibotenic acid. These results suggest that impairments of spatial learning and memory might be attributable to the degeneration of septohippocampal cholinergic (SHC) neurons and that YMJd treatment ameliorated learning and memory deficits partly due through neuroprotective effects on the central acetylcholine system. Our studies suggest that YMJd might be useful in the treatment of Alzheimer's disease.

To investigate emission properties depending on the inorganic binders, two types of photosensitive CNT paste were formulated using glass frit and spin on glass (SOG) as an inorganic binder. For uniform thickness and patterning of CNT paste, backside exposure and development process were carried out after screen printing and drying process. CNT paste films with different inorganic binders were fired at various conditions and their emission properties were evaluated. We also investigated emission stabilities of printed CNT emitter after the electrical aging treatment.

Single-walled nanotubes (SWNTs), thin multiwalled carbon nanotubes (t-MWNTs) and multiwalled carbon nanotubes (MWNTs) were treated with H2SO4–HNO3 acid solution, under different chemical conditions. The acid-treated CNTs were dispersed in DI water and in poly (3,4-ethylenedioxythiophene) (PEDOT) solution. Furthermore, the finely dispersed CNTs/PEDOT solutions were employed to a simple method of bar coating to obtain the transparent conductive films on the glass and polyethylene terephthalate (PET) film. A sheet resistance of 247 V/sq and a transmission of 84.7% were obtained at a concentration of the acid-treated CNTs of 0.01 wt.%. D 2005 Elsevier B.V. All rights reserved.

Background: Acinetobacter baumannii is one of the most important nosocomial pathogens, and its multiple antibiotic resistance has emerged as an obstacle in the treatment of these infections worldwide. Aims: To identify risk factors of mortality for A. baumannii bacteraemia. Methods: A retrospective cohort study of 72 patients with significant A. baumannii bacteraemia was conducted to evaluate risk factors for mortality. Results: The median age of the 72 enrolled patients was 48 years, 96% of the cases were hospital-acquired, and the bacteraemia-related mortality rate was 29% (21 of 72 patients). Univariate analysis revealed that the risk factors for mortality included: an elevated acute physiology and chronic health evaluation (APACHE II) score, receipt of in vitro ineffective definitive antimicrobial therapy, in vitro A. baumannii resistance to cefoperazone/ sulbactam, neutropenia, and presentation with septic shock. Multivariate analysis reveals that the independent risk factors for mortality are neutropenia and elevated APACHE II scores. Conclusion: Risk factors such as neutropenia and elevated APACHE II scores are found to be associated with higher mortality rates of A. baumannii bacteraemia. Further study is necessary for the determination of optimal strategies for both the prevention and treatment of these infections. (Intern Med J 2005; 35: 599–603)

Escherichia coli is associated with inflammation in the brain. To investigate whether astrocytes are involved in E. coil-induced inflammation, we assessed the levels of expression of proinflammatory mediators produced by E. coli-infected astrocytes. E. coli infection in primary human astrocytes and cell lines increased expression of the CXC chemokine IL-8/GRO-alpha, the CC chemokine MCP-1, TNF-alpha, and iNOS. E. coli infection activated p65/p50 heterodimeric NF-kappaB and concurrently decreased the signals of IkappaBalpha. Blocking the NF-kappaB signals by IkappaBalpha-superrepressor-containing retrovirus or antisense p50 oligonucleotide transfection resulted in down-regulation of expression of the proinflammatory mediators. Furthermore, superrepressors of IkappaBalpha, IkappaB kinase (IKK) or NF-kappaB inducing kinase (NIK) inhibited the up-regulated expression of the downstream target genes of NF-kappaB such as IL-8 and MCP-1, and superrepressors of TNF receptor-associated factor (TRAF)2 and TRAF5 also inhibited expression of the E. coli-induced target genes of NF-kappaB. These results indicate that proinflammatory mediators such as the CXC chemokine IL-8/GRO-alpha, the CC chemokine MCP-1, TNF-alpha, and iNOS can be expressed in E. coli-infected astrocytes via an NF-kappaB pathway, suggesting that these mediators may contribute to inflammation in the brain, including infiltration of inflammatory cells.

A two-dimensional computational model, coupling a hmacroscopic heat and fluid flow analysis with a cellular automaton model under electromagnetic stirring, was developed. The dynamic evolution of solidification grain structures and transport phenomena during solidification were presented successfully. The Gaussian distribution was chosen to deal with nucleation events both on the mold wall and in the bulk melt. The KGT (Kurz-Giovanola-Trivedi) model, based on the calculated temperature field, was adopted to evaluate the growth velocity of a dendrite tip. The material used was an Al-5.0wt%Cu alloy. Both the computational and experimental results showed that grain refinement was improved remarkably with electromagnetic stirring. The fully equiaxed grain structures were obtained with a proper choosing of the casting process variables, such as pouring temperature, cooling rate and stirring intensity.

We present the clinical and molecular findings of mosaic ring chromosome 4. The patient was referred to us for infertility and short stature. Results of three repeated cytogenetic analyses from lymphocytes showed a similar mosaic karyotype with multiple cell-lines [46,XX,r(4)/45,XX,–4/46,XX,dic r(4)/47,XX,r(4),+r(4)/46,XX]. FISH showed deletion of the 4p subtelomeric region and the 4q telomeric region from the ring chromosome 4. The breakpoints were mapped using molecular analysis. Parental karyotypes were normal. During the course of this study, the patient became pregnant without assisted reproductive technology. The result of amniocentesis performed at 16 weeks gestation showed a normal karyotype. Delivery was uncomplicated. This is the first report, to our knowledge, of the presence of ring chromosome 4 having various mosaic conditions in a female having a chromosomally normal fetus.

For field emitters as a cathode of traveling wave tube–microwave power amplifiers (TWT–MPA), field-emission (FE) properties of in situ grown carbon nanotubes (CNTs) onto electrically conducting substrate were systematically characterized. CNTs grown on the Co/TiN coated Ta substrate with properly controlled process exhibited the best FE property. The maximum current density and corresponding total emission current were 3.5 mA/cm 2 and ∼1.7 mA at 21.6 V/μm, respectively. Details on the correlation between the FE properties and the morphological parameters will be discussed.

Enzymatic hydrolysis of onion was performed by three different commercial enzyme products (Econase, Rapidase and Viscozyme) for preparation of onion hydrolysates. The hydrolysis yield was determined through the analysis of reducing and total sugar contents in final hydrolysates. Total sugar contents after 2 h-hydrolysis with Econase, Rapidase and Viscozyme were 59.6, 64.1 and 62.2 mg/mL, respectively, and reducing sugar contents of 28.5, 42.7 and 35.9 mg/mL in the same order. According to these results Rapidase was more suitable for the hydrolysis of onion than the other enzymatic products. The effect of temperature on non-enzymatic browning reaction kinetics of the onion hydrolysate was determined. The browning index variation was adequately described by both the first- and the zero-order kinetic. However, the zero-order kinetic model was preferred because its fitting was higher. The values of kinetic constants were 0.081 (60 C), 0.185 (70 C), 0.270 (80 C) and 0.377 (90 C). According to the Arrhenius model, the activation energy for browning index in the range 60–90 C was 21.9 kJ/mol.

Gene therapy represents a possible alternative to the chronic delivery of recombinant antiangiogenic proteins to cancer patients. We have constructed retroviral and adenoviral vectors that express murine N-terminal fragments of thrombospondin-2 (NfTSP2), a potent endogenous inhibitor of tumor growth and angiogenesis. To test the possibility of anticancer gene therapy using NfTSP2, we tested whether an ex vivo retrovirus-mediated procedure could be used for the treatment of tumors. The treatment of tumor-bearing mice with syngenic immortalized cell lines expressing NfTSP2 led to a tumor volume reduction up to 70% as compared with the controls (P

A triode structure of field emission displays based upon carbon-nanotube emitters is studied. In this structure, gate electrodes are located underneath cathode electrodes with an in-between insulating layer, so called an under-gate-type triode structure. The modulation of electron emission by changing gate voltages is confirmed. Charging on the insulating layer by emission electrons could be reduced by pattering the insulating layer. Results of our experiment show that emission properties are improved in the triode structure with the patterned insulator. The simple structure and fabrication process may lead the under-gate-type triode structure to the practical applications.

Vertically aligned carbon nanorods and multi walled carbon nanotubes (MWNTs) were synthesized by electron cyclotron resonance chemical vapor deposition (ECR-CVD) on Ni- coated glass substrates with the RF-self biasing of –100 and –200 V, respectively. High-resolution transmission electron microscopy indicated that the distance between adjacent graphene layers of carbon nanorods is much larger than that of well-graphitized MWNTs. In electron-energy-loss spectra, the energy of π+σ plasmon peak for the carbon nanorod shifts towards lower value of 23.8 eV, by comparison with the well-graphitized MWNT at 25.5 eV. In addition, the π palsmon peak at 6 eV is clearly defined for the well-graphitized MWNT, but not seen for the carbon nanorod. X-ray photoelectron spectroscopy also showed that the delocalization of π electrons gets more pronounced with the structural evolvement from the carbon nanorod to the well-graphitized MWNT. Therefore, it is suggested that ionic bombardment can provide sufficient internal energy for dehydrogenation from hydrocarbon molecules, and thus, well-graphitized MWNTs could be grown even at low temperatures.

In the present study, three-dimensional thermal elastoplastic analysis has been carried out in order to clarify the mechanical phenomena of the thermal elastoplastic behaviour of multispot welded joints. As the shape of multispot welded joints is not axisymmetrical, unlike single spot welded joints, the solution domain for simulation should be three-dimensional. Therefore, the present study first developed three-dimensional heat conduction and thermal elastoplastic programs using the isoparametric finite element method. Second, from the results analysed by the developed programs, thermal and mechanical characteristics and their production mechanisms on single and multispot welded joints were clarified. Moreover, effects of pitch length on the temperature distribution, welding residual stresses and plastic strain of multispot welded joints were evaluated, indicating that a pitch of 30 mm was more advantageous compared to a pitch of 15 mm.

The effect of NH 3 plasma pre-treatment on the growth characteristics of CNTs was investigated. We observed that NH 3 plasma pre-treatment etched and conglomerated Ni catalyst film, resulting in the formation of Ni nanoparticles. The aligned CNTs from the Ni nanoparticles were grown by plasma enhanced chemical vapor deposition (PECVD). As Ni film thickness decreased from 300 to 30 A, the size of Ni nanoparticles decreased about from 140 to 90 nm and the average diameter of CNTs became smaller. As the NH 3 plasma power was increased, the density of Ni nanoparticles was decreased, leading to the decrease in the density of CNTs.

We controlled the density of carbon nanotubes (CNTs) through in situ NH3 plasma pretreatment and investigated field emission properties with the density variation. Ni catalytic layer was transformed into small nanoparticles with NH3 plasma pretreatment time and power. As NH3 plasma pretreatment time was increased, the growth rate of grown CNTs was gradually decreased. Also, the density of CNTs reduced from 2×109 to 8×106/cm2 with an increase in NH3 plasma pretreatment time from 10 to 30 min for the Ni layer of 10 A. With a decrease in the density of CNTs, the emission current density was increased and turn on electric field was decreased. We obtained large and uniform emission current (about 9 mA/emission area of 0.49 cm2) from CNTs film with the density of 8×106/cm2.

Vertically aligned multi walled carbon nanotubes (MWNTs) were synthesized by electron cyclotron resonance chemical vapor deposition on Ni-coated glass substrates at temperatures as low as 400°C. Negative self-biases were applied to the substrates by radio-frequency (RF) plasma for ion bombardment of the growing surface. It was observed that ion bombardment by RF biasing to the substrates had a great effect upon the growth of carbon nanotubes and their morphologies. High-resolution transmission electron microscopy revealed that the degree of ordering of graphene layers in the synthesized nanotubes increased with RF bias. Raman spectroscopic analyses indicated that the shortening of C–C bonds within the graphene layers of the MWNTs occurred at larger negative biases, which seemed to result from removal of bonded hydrogen from the MWNTs by ion bombardment.

We controlled the size and distribution of catalytic Ni nanoparticles to control the density and diameter of carbon nanotubes (CNTs). With an increase in plasma power from 30 to 90 W for Ni layer of 30 A, the average diameter of particles decreased from 157 to 58 nm due to an enhanced etching effect. Size and distribution of Ni nanoparticles varied by plasma power, pre-treatment time and thickness of catalytic layer, resulting in the change in the density of grown CNTs. Density of CNTs reduced from 1×10 9 to 8×10 6 cm −2 , depending on the pre-treatment condition.

We carry out the in situ analysis of chemical species for the growth of carbon nanotubes (CNTs) in direct current plasma enhanced chemical vapor deposition (DC-PECVD) with C 2 H 2 –NH 3 , C 3 H 4 –NH 3 and CO–NH 3 mixtures by optical emission spectroscopy (OES). From OES analysis, it was shown that the hydrogen related radical was regarded as etching species in CNTs growth and the C 2 and CH radical as available carbon sources for the growth of CNTs irrespective of carbon source gas. As the NH 3 flow rate changed, different chemical species in plasma made effects on the growth of CNTs depending on the source gas.

The morphology of primary phase in solidification of hypo-eutectic Al-Si alloys has been investigated by both experiment and numerical simulation using the modified cellular automaton(MCA) method. ...

We have developed an easily operable scanning near-field optical microscope for multicolor fluorescence imaging by applying a highly sensitive charge-coupled-device (CCD) camera. The CCD camera is used as a variable area photosensor, and a mean intensity of a selected area in the CCD camera is converted to a numerical value. By combining a spectrometer with the CCD camera, arbitrary wavelength ranges can be selected to provide plural fluorescence images separated by fluorescence wavelength. The function of the system is demonstrated by imaging mixed fluorescence particles and a two-color stained chromosome sample of Hordeum vulgare treated with a two-color fluorescent banding stain method.

We show that in dimension 8, a semiflat metric is flat and that in dimension (8k+4) higher than 8, a semiflat metric does not necessarily imply flat.

The effect of temperature (296–238 K) on the reaction of combustion soot (n-hexane) with ozone at low concentration (6–8 ppm) has been measured. Long optical path FTIR spectroscopy has revealed the rate law for ozone loss beyond initial stages, second order in O3, to be the same over this range of conditions. The reaction rate is 3.5 times lower at 238 K than at 296 K, and reveals an activation energy of 12.9 ± 0.5 kJ mol−1. The effect of humidity on the reaction has been estimated using its recently determined rate law dependence (p0.2). These data, differing from O3 reaction kinetics obtained from other types of carbonaceous particles used as surrogates for atmospheric soot, have implications for the role of combustion soot in atmospheric chemistry. Any involvement of aircraft soot in ozone depletion near the tropopause, for example, should be estimated using these temperature and humidity dependences.

Interleukin-18 (IL-18) has multiple important pro-inflammatory effects, including the induction of interferon-gamma (IFN-gamma) in various diseases. In this study, we investigated the IL-18-producing activities in human pulmonary and pleural tuberculosis (TB) in response to purified protein derivative (PPD) antigen (Ag) from Mycobacterium tuberculosis. The most significant IL-18 production was found in chronic refractory TB (CRTB) patients. However, IFN-gamma production in CRTB patients was significantly less than that in healthy tuberculin reactors or in patients with tuberculous pleurisy (TBP). Elevated levels of both IL-18 and IFN-gamma were found in pleural fluids from TBP patients. In vitro production of IL-18 was dramatically decreased following an 18 h stimulation with PPD. However, IFN-gamma was markedly increased in pleural mononuclear cells from TBP patients after in vitro stimulation with PPD. The mesothelial cell type was the main source of pro-IL-18 in pleural cells from TBP patients, suggesting an important role for these cells in TBP. Taken together, these data indicate that IL-18 is elevated in peripheral blood mononuclear cells from CRTB patients, as well as at the site of TBP, indicating a possible role for IL-18 in both protective immunity and pathologic responses in human TB.

We investigated the localization accuracy of single current dipoles from the tangential components of auditory evoked fields. The tangential fields were measured using planar gradiometers arranged in a way so as to detect two orthogonal field components parallel to a flat plane. Field responses to 1 kHz pure tones were recorded and equivalent current dipoles (ECDs) of N1m peak were estimated based on a locally fitted spherical conductor model. As a measure of localization accuracy, the standard deviation of the coordinates of the ECDs of N1m was obtained from repeated measurements for one subject. The estimated ECDs had a standard deviation of 5.5 mm and their mean location was at the supratemporal plane in the sylvian fissure on the MR image of the subject. In order to investigate the contribution of various errors to the localization accuracy, simulations using a sphere model and experiments using a realistically shaped skull phantom were performed. It was found that the background noise, which consisted of instrumental noise and spontaneous brain fields, was the main source of the errors that could explain the observed standard deviation. Further, the amount of systematic error was much less than the standard deviation due to the background noise. These results suggest that the volume currents in a non-spherical conductor shape such as the temporal region do not produce substantial errors in the localization of current dipoles from tangential components of auditory evoked fields.

The angiotensin-converting enzyme (ACE) inhibitory effect was tested in the culture broth from submerged mycelial cultures of 20 basidiomycetes. The ACE inhibitory effect of culture broth from Flammulina velutipes strain 414 was the highest (52.8%), followed by Lentinus edodes strains 2 (44.4%) and 16 (41.3%). Nutritional requirements for the production of ACE inhibitory substance from F. velutipes were studied. Sucrose, ammonium acetate, and glutamic acid were chosen for the maximum production of ACE inhibitory substance. The optimal medium composition was (g/l): sucrose 20, ammonium acetate 5, glutamic acid 2, KH(2)PO(4) 3, MgSO(4).7H(2)O 0.8, and yeast extract 0.5. Under optimal culture conditions, the ACE inhibitory effect was more than 80%.

Triode-type carbon-nanotube field emission displays (CNT-FEDs) with the 5″. diagonal were fabricated using screen printing as well as thin film processing. We developed a photosensitive paste including single walled CNTs for screen printing. CNT emitter dots with the diameter of 5 μm were defined inside gate holes with a diameter of 10 μm by screen printing the CNT paste and a subsequent backside photolithography. CNTs were exposed to erect on the surface by development, serving as electron emitters. A thick Ni wall structure was electroplated just above gate electrodes to suppress diode emission caused by an anode potential and to improve focusing of electron beams. An onset gate voltage for emission was as low as 40–45 V. Under an optimum design of a FED panel, R, G, B colors were satisfactorily separated. Our vacuum-sealed CNT-FED demonstrated full color moving images with high brightness and good color purity at a video-speed operation.

We report a method to fabricate carbon nanotubes (CNT)/conducting polymer composite films for the application of CNTs to field emission displays. The composite was prepared by a combination of electrochemical polymerization of pyrrole and electrophoretic deposition of CNTs. We obtained a uniform CNT/conducting polypyrrole polymer composite film. The CNTs were mainly coated on protrusions of the polypyrrole film and emitted electrons without rubbing and stretching. We realized a triode-type field emission array (FEA) using the CNT/polypyrrol composite. This FEA showed that the emission current was modulated by gate voltage of 30 V. The film morphology and emission characteristics of the CNT/conducting polymer composite were studied using optical microscopy, scanning electron microscopy, and an emission test in vacuum.

A two step isothermal heating process was developed to prepare a semisolid slurry of AZ91 alloy. In the process the alloy was heated isothermally at its liquidus temperature, cooled to a semisolid temperature, and then heated isothermally at the temperature before it was deformed. This relatively simple method was found to be a highly efficient way to generate a non-dendritic microstructure. The influence of strontium addition on the soundness of semisolid formed parts was also studied. AZ91 alloy is prone to shrinkage porosity because the freezing range of the alloy is wide. Porosity formation during the process was observed to be suppressed by the microaddition of strontium.

The effect of partial substitution of tungsten for molybdenum on the microstructure and corrosion resistance in 22Cr–5Ni–3Mo duplex stainless steel (DSS) has been investigated following aging heat treatments in a temperature range of 600-1000°C. Electrochemical tests were carried out for the evaluation of corrosion resistance. Aging treatment had hardly influenced the general corrosion resistance. With the increase of aging time, the pitting corrosion resistance of the DSSs had decreased. After aging for 2 min at 700–900°C, the pitting potential of the 3Mo steel decreased remarkably, while that of the W substituted steel hardly changed. During aging, the intermetallic σ and secondary austenite (γ2) phases were precipitated, and the pitting corrosion and intergranular corrosion resistance were significantly decreased after aging at 700–750°C for 10 h, which could be caused by the γ2 formation. The γ2 phase could effect the depletion of molybdenum and chromium in the γ2 /α and γ2/σ boundaries.

Effects of growth parameters such as plasma intensity, flow rate, composition of reactant gases, growth temperature, and hole size on the selective area growth (SAG) of carbon nanotubes (CNTs) were investigated using the triode type field emission array structure in plasma enhanced chemical vapor deposition (PECVD) system . As the plasma intensity was increased, the diameter of CNTs was reduced from 180 to 90 nm, but the growth rate was promoted. With an increase in the NH 3 flow rate, the average diameter of CNTs was decreased due to the enhanced etching effect by NH 3 . An increase in the total flow rate of reactant gases reduced the growth rate of CNTs, but the average diameter of CNTs remained nearly constant. An increase in growth rate and diameter was observed at higher growth temperatures. As the hole size of the triode structure increased, the growth rate of CNTs gradually decreased because of the reduced lateral diffusion of reactant species into the hole.

The effects of NH 3 on the growth characteristics of carbon nanotubes (CNTs) were systematically investigated in plasma enhanced chemical vapor deposition (PECVD) with C 2 H 2 as a carbon source. CNTs were not formed when N 2 was used instead of NH 3 . Carbon films instead of CNTs were observed without NH 3 . As the growth of CNTs with only C 2 H 2 proceeded after the initial growth of CNTs with NH 3 and C 2 H 2 , films were formed with rugged surface morphology instead of nanotube-features. High-resolution transmission electron microscopy revealed that carbon films consisted of graphite carbons, and 20–30 nm graphite onions covered with amorphous layers. NH 3 was found to be essential to the growth of CNTs in the PECVD system. NH 3 may provide additional etching effects for the growing carbon surface, and suppression of carbon supply.

Alumina tubes of diameters 8 and 20 mm were successfully fabricated by centrifugal casting of a weakly-coagulated aqueous slurry in rotating tubular molds under accelerations of 28 and 70 times of gravitational acceleration, respectively. Due to differential settling during the casting, the microstructure was not uniform throughout the tubes but there was an indication of porosity-gradient through their thickness. This porosity-gradient might be beneficial for membrane application. We could control the porosity, pore size distribution and thus permeability of the tubes by varying particle size of starting alumina powders and controlling sintering temperature. This investigation demonstrates that centrifugal casting be a promising technique to fabricate alumina tubes for membrane application.

The dependence of specific properties of black carbon (BC) soots on fuel type and combustion conditions has been studied, and the effects of these properties on soot particle hydration and reaction with ozone determined. Series of soots were prepared from n-hexane, diesel and JP8 aircraft fuels, utilizing a flow combustion system designed for accurate control of the air/fuel ratio in premixed flames. It has been shown that, for each of these, linear relationships exist between the state of soot surface oxidation, surface area, unpaired electron spin density, and air/fuel ratio. The interrelationship of these properties potentially enables the preparation of soots with pre-selected characteristics by establishing combustion conditions for each fuel type. Predictable variations in these soot characteristics have been demonstrated through preparations near sea level and at higher elevation. Soot hydration and its reactivity with ozone are quantitatively related to surface oxidation and, thus, the air/fuel combustion ratio for soot's formation in premixed flames. The effect of relative humidity (RH) on the soot-ozone reaction over the O3 concentration and RH ranges 2–4.8 ppm and17–78%, respectively, is expressed by−d[O3]/dt =k[O3]2[H2O]0.2and is directly related to particle surface oxidation.

We fabricated a low-noise magnetoencephalography (MEG) system based on a continuously operating reliquefier for cooling of low-temperature superconducting quantum interference device gradiometers. In order to reduce the vibration transmission, the gradiometers are mounted in the vacuum space of the helmet dewar with direct thermal contact with the liquid helium helmet. The reliquefier uses a 1.4 W pulse tube cryocooler with a remote motor, and a horizontal transfer tube with a downslope angle of 1°. The white noise of the system is 3.5 fTrms/√Hz (at 100 Hz). The vibration-induced peak at 1.4 Hz is 18 fTrms/√Hz averaged over the whole helmet array of 150 channels, which is the lowest among the reported values using reliquefier cooling and comparable to the noise peak cooled by conventional direct liquid helium cooling with axial gradiometers of the same baseline. The spontaneous brain activity signal showed nearly identical signal quality with the reliquefier turned on and off, and the reliquefier-based MEG system noise is well below the brain noise level.