Nano-biotechnology (nanobio) is one of the great technological fusions from various different fields. Analysis of biological functions significantly improved because of the recent nanotechnology development. We study this field based on neuroscience. Here we introduce our approach to this field, starting from neural analysis to receptor analysis in order to establish a nano-bio interface. Nano-gap electrode is one of the possible devices for this purpose. Combination of the electrode with receptor protein is investigated.

抄録全体を表示

Recent topics in spectroscopy and photochemistry of biomolecules adsorbed on surfaces are discussed in terms of synchrotron radiation techniques. Due to remarkable development of high resolution spectroscopy in soft X-ray region, each amino acid is now being able to be distinguishable each other.

抄録全体を表示

The studies on the chemical reactions of organic molecules induced by low-energy electrons and gas cluster ions are reviewed. The author's group has developed the in-situ observation technique for electron-irradiated surfaces. The technique employs a scanning tunneling microscope as a field-emitted electron source, as well as a probe for surface analysis. By using the technique, we have investigated the effect of low-energy-electron irradiations to adsorbed molecules, such as ethylene and DNA. Desorption, dissociation of the molecules and changes to other chemical species, were observed, depending on electron energy and electron dosage. When a gas cluster ion, consisting of thousands of atoms or molecules, collides with a solid surface, several types of reactions are uniquely induced at the surface. The average kinetic energy of a constituent atom of the cluster can be defined by dividing the acceleration energy by the number of constituent atoms. Thus, very low-energy-ion irradiation is easily achieved by using large cluster ions. DNA adsorbed graphite surfaces were irradiated with argon(Ar) gas cluster ions. The secondary ion yield and the structural changes of the surfaces were investigated. These results are compared with the case by the irradiation with monomer ions (Ar⁺) and are discussed from the view point of the kinetic energy of a constituent atom of the cluster ion.

抄録全体を表示

Surface temperature and gas pressure are major parameters for control of chemical reactions between gas molecules and solid surfaces, followed by ultra-thin layers formation or etching reactions. Molecular adsorption at surfaces are occasionally induced by translational kinetic energy of incident molecules even if the incident energy is only several eV. The chemical reaction field is extended into a bulk region deeper than 10 nm if the incident energy is achieved to several keV. Thus the incident energy is the third parameter for control of chemical reactions. In this review article, generation methods of various kinds of high-speed atomic and molecular beams are briefly introduced. Especially, supersonic molecular beam techniques and neutral beam generation methods based on ion beams techniques are concretely explained. Furthermore, as an application of beam-induced surface nano-process study, etching induction at silicon surfaces by supersonic chlorine molecular beams, oxidation induction by supersonic oxygen molecular beams, and nitridation of a silicon oxide film on an Si(001) substrate at room temperature by nitrogen atomic ion beams are reviewed.

抄録全体を表示

Synchrotron light-excited process is one of the promising techniques for future semiconductor processes. In this report, we introduce several examples of the application of the synchrotron light-excited process on the semiconductor development, and focus especially on the growth and etching of II-VI compound semiconductor. In addition, the outline of a beamline for the development of advanced materials and processing at Saga Light Source is reported as a future perspective of the synchrotron light-excited process.

抄録全体を表示

Oxidation reactions at Si(001) surfaces have been studied via real-time in-situ photoemission spectroscopy for chemical bonding states of Si and O atoms, and mass spectrometry for desorbing SiO molecules with synchrotron radiation and supersonic O₂ molecular beams in the temperature range from 900 K to 1300 K. In our previous studies, the SiO desorption yield decreased with increasing incident energy in the temperature range from 900 K to 1000 K,. In that case, the time evolutions of Si 2p photoemission spectra showed that SiO₂ structure on the surface was easily formed by the action of larger incident energy and the increased SiO₂ coverage correlated with the decreased SiO desorption yield. In this study, coincidence measurements of Si 2p photoemission spectra and SiO desorption yield revealed that the decrease of SiO correlated with the increase of Si²⁺ component, and the SiO desorption was terminated at the oxide thickness of 0.22 nm. These facts indicate that the SiO desorption takes place at the topmost Si dimmers and its precursor is so called T site, in which O atoms are bonding with the dangling bonds of the dimmers. Consequently, M1 and M2 in the Dual-Oxide-Species (DOS) model were clarified to be T sites and Si²⁺ states, respectively.

抄録全体を表示

The initial sticking probability S₀ of O₂ molecules on a Ti(0001)1×1 surface at room temperature was measured as a function of translational kinetic energy E_t by real-time photoelectron spectroscopy. The O 1s photoelectron spectra can be fitted well with three components A, B and C, where the chemical shift of component B and C are +0.7 and +1.6 eV relative to the binding energy of component A (528.8 eV). Upon exposing to the O₂ beam, component A and C appear dominantly and component B grows with an incubation time, indicating that two kinds of chemical adsorption states are concerned with dissociative adsorption of O₂ molecules at the initial stage. The E_t dependences of S₀ show quite different behaviors between component A and C: S₀ of component C decreases monotonously with E_t and is almost constant above 0.6 eV, while S₀ of component A shows a rapid decrease followed by a gradual increase with a minimum at ∼0.5 eV and then decreases two small maxima at ∼0.9 and ∼1.8 eV. The observed E_t dependences of S₀ for component A and C are discussed in terms of a trapping-mediated adsorption and an activated adsorption process and the chemical adsorption state corresponding to component A and C is also considered.

抄録全体を表示

Soft x-ray and gamma-ray beam sources are developed by using laser and high energy electron beams. Laser plasma soft x-ray source is a cryogenic Xe target irradiated by a high average power (>100 W) and high peak power (30MW, 0.3 J/10 ns) laser. A conversion efficiency from the laser energy to the soft x-ray (70-200eV) energy of 22% was achieved. Laser Compton gamma-ray source on a synchrotron radiation facility, NewSUBARU, is new quasi-monochromatic high energy photon beam. World highest class gamma-ray flux of more than 10⁶ photons/s is generated at photon energy range of 6 to 17 MeV.

抄録全体を表示

In the development of extreme ultraviolet (EUV) lithography source using laser-produced plasma (LPP), it is important to investigate the optimum wavelength of the driver laser to obtain the high conversion efficiency. We have proposed the EUV generation pumped by CO₂ laser-produced plasma. In this article, we show the characteristics of EUV emission from gas and solid Xe irradiated by a TEA CO₂ laser. The conversion efficiency to 13.5 nm was ∼0.2 %. This value is comparable to those of Nd: YAG LPP with Xe in early works. In order to gain insight into the difference between the CO₂ LPP and Nd:YAG LPP, we investigated the emission characteristics from Nd: YAG LPP and CO₂ LPP with solid tin under the same experimental setup. As the results, we confirmed that the conversion efficiency of CO₂ LPP is comparable to that of Nd: YAG LPP. The conversion efficiency was estimated to be 2 % in maximum.

抄録全体を表示

LIGA process has been developed in the 2.5-dimensional world. We introduced new technologies of a 3D X-ray lithography and a worm injection molding with an unscrewing demolding mechanism, and succeeded in the deployment of a three- dimensional LIGA process. Furthermore, it succeeded to fabricate a spiral microcoil using 3D-LIGA process and a metallization technique combined flat and smooth electroplating and isotropic chemical etching. A diameter of the microcoil was 0.5 mm and the length was 1 mm. The width of coil lines was 10 μm, and the pitch was 20 μm. Also the characteristics as an inductor of this microcoil is such that the inductance and the quality factor at the frequency of 1 GHz was 91 nH and 5.8, respectively.

抄録全体を表示

We fabricated two kinds of Si X-ray masks only in a dry etching without electroplating and chemical etching. The first mask is a stencil X-ray mask without a membrane. An X-ray absorber of thickness 30 μm with vertical sidewalls was able to be fabricated. The second mask is an X-ray mask with a Si membrane. The thickness of the X-ray absorber and the membrane is 30 μm and 5 μm, respectively. In addition, we succeeded in demonstration of the X-ray lithography in the beam line BL-4 of the synchrotron radiation facility TERAS of AIST using the Si stencil X-ray mask. Line and space patterns with the line width 2 - 200 μm were transcribed plainly on the surface of a PMMA sheet. It was confirmed that the edge of PMMA microstructures was sharp by SEM observation.

抄録全体を表示

We prepared five kinds of photo-curable resins, and conducted evaluation experiments for their thermal properties, mechanical properties, and application availability for the imprint process. Measurements of thermal properties using the TG method, TM-DSC method, and laser interferometric method were studied. From these measurements, it was found that the measurements of the thermally stable temperature, glass-transition temperature, and linear expansion coefficient of the resins were possible. Also, measurements of mechanical properties using the nano indentation were studied. In this method, the measurements of Young's modulus of the thin resin film on the substrate were possible. With respect to application availability for the imprint process, we investigated effects of the mold release treatment and their durability for two kinds of resins by measuring their adhesive force. It was observed that the difference in durability of mold release treatment effects depends on the resin type.

抄録全体を表示

We have investigated nanomachining of inorganic materials using laser plasma soft X-rays. The soft X-ray was generated by irradiating Ta targets with pulsed Nd:YAG laser light. The laser plasma soft X-rays were focused using an ellipsoidal mirror, which is designed so as to focus soft X-rays at around 10 nm efficiently. The focused soft X-rays were incident to the surfaces of inorganic materials such as silica glass, LiF, CaF₂ and LiNbO₃. It is found that these materials are ablated by soft X-ray irradiation. In particular, silica glass can be ablated at rates of 0.2-150 nm/shot, which can be controlled by the intensity of soft X-rays. It is remarkable that silica can be ablated smoothly with a roughness of 1 nm after 10 shots of soft X-ray irradiation at a rate of 50 nm/shot. In order to demonstrate nanomachining of silica glass, we used contact masks on top of silica glass plates fabricated by electron beam lithography technique. The silica glass plates were irradiated with laser plasma soft X-rays through the windows of the contact masks. We found that nanofabrication of trenches with a width of 70 nm are performed clearly.

抄録全体を表示

We have developed a new 3D x-ray lithography system for LIGA processing using synchrotron radiation at the NewSUBARU facility of the University of Hyogo. The x-ray lithography system can utilize two different energy regions; one is a high-energy region from 3 keV to 10 keV, and the other is a low-energy region from 0.1 to 2 keV. Each energy region can be selected in accordance with the size and shape of the desired microstructures. It is demonstrated that large-area high luminescence 7 inch optical waveguide for the liquid crystal back light unit was successfully fabricated using this x-ray lithography method.

抄録全体を表示

Secondary electrons with kinetic energies below 20 eV are abundant species generated in living cells by the irradiation with ionizing radiations. It is unclear whether such low-energy electrons are able to induce damage on DNA. In this study, we have directly observed the structural changes of DNA molecules under the irradiation with 4-40 eV electrons which are field-emitted from the tip of a scanning tunneling microscope. Single- and double-strand breaks of linear DNA molecules (λDNA and ΦX DNA) are induced by the electron irradiations. By the electron irradiations of circular DNA molecules (pUC18 DNA) in an entanglement, some parts of the DNA were lost or spread by the dissociation of the molecules. These electron-induced reactions are strongly dependent on the electron energies.

抄録全体を表示

In mammals, two kinds of adipose tissue are known to exist, i.e., white (WAT) and brown (BAT) adipose tissue. The physiological role of WAT is storage of excess energy as fat, whereas that of BAT is the expenditure of excess energy as heat. The uncoupling protein UCP1, which is specifically expressed in brown fat mitochondria, dissipates the proton electrochemical potential across the inner mitochondrial membrane, known as a driving force of ATP synthesis, and thus it dissipates excess energy in a form of heat. Because deficiency in effective expenditure of excess energy causes accumulation of this energy in the form of fat (i.e., obesity), it is very important to understand the energy metabolism in this tissue for the development of anti-obesity drugs. In this article, in addition to providing a brief introduction to the functional properties of BAT and UCP1, the results of our exploratory studies on protein components involved in the energy-dissipating function in BAT.

抄録全体を表示

Microreactors and micro total analysis system (μTAS) are recognized as powerful tools for genomics, proteomics, clinical diagnostics, and environmental testing. In this paper, we describe enzyme linked immunosorvent assay (ELISA) using a new microreactor with a vertical fluid flow operation. This microreactor is composed of two reaction vessels stacked on the vertical lines through PMMA fluid filters (φ3mm). The fluid filters constructed by deep X-ray lithography possess 2,100 pores (φ 40 μm), and have valve functions, which maintain liquid layer in each reaction vessel. In addition, the liquid can be selectively transferred by air pressure from upper vessel to lower, and vice versa. As a model of ELISA using the microreactor, we planed to detect mouse immunoglobulin (IgG). We bound the goat anti-IgG antibody to the surface of the PMMA filters, and assayed the IgG by ELISA using anti-IgG antibody/ peroxidase conjugate. We found that the mouse IgG (100 ng/ml) was quantitatively detected within 45 min of analytical period, which was ca. 1/3 of the period required for the conventional method using micro titer plate.

抄録全体を表示

The vertical fluid flow operation and multifunctional fluid filter for the operation were proposed. We calculated the flow behaviour by FLUENT of the CFD software. The CFD analysis estimated the threshold pressure of flow transmission and efficiency of mixing and the results indicated that the vertical liquid transportation is useful and the good multi function as channel , valve , mixer and micro reactor of the filter we proposed. So we fabricated the filter by SR lithography and performed the flow transmission experiment. As the result, the calculated threshold pressure configurate the measured pressure. We demonstrated ring-opening reaction of the Catechol by Catechol 2,3-dioxygenase as the catalyst to evaluate the performance of mixing. It shows that the filter mixes the fluid efficiently and is enough to mix at five times transportation.

抄録全体を表示

An electrochemical sensing system using a planar microelectrode array has been developed to monitor biological molecules with relatively high special and temporal resolutions. This enables us a real time imaging of the biological molecules release from a tissue invasively. In this study, we have established a multichannel hydrogen peroxide (H₂O₂) sensing system to monitor the real time H₂O₂ distribution in a tissue using a planar sensor array. H₂O₂ has been recognized in association with the pathology of neurological diseases because it is a by-product of a degenerative reaction of reactive oxygen species, one of the major causes of oxidative stress in mammalian cells. The sensor array is based on a 64-channel ITO electrode array of 50x50 μm electrodes modified with an enzyme, horseradish peroxidase, and an electron transfer mediator. Then we place a cultured rat hippocampal slice on the array and measure the current at each sensor using a multipotentiostat. When we introduce bicuculline into the solution as a stimulant, in the presence of a catalase inhibitor, we can observe a distinct increase in the H₂O₂ concentration. This real-time H₂O₂ distribution monitoring system will be a powerful tool with which to explore the neuronal cell death mechanism in biological systems.

抄録全体を表示

Microchip electrophoresis has recently attracted much attention in the field of nuclear acid analysis due to its high efficiency, ease of operation, low consumption of samples and reagents, and relatively low costs. Nucleic acid fragments are separated by capillary electrophoresis in a chip with microfabricated channels, with automated detection as well as on-line data evaluation. Microfabricated devices are forecast to be fundamental to the postgenome era, especially in the field of genetics and medicine. However, although there are many reports of the use of these instruments to evaluate standard DNA, DNA ladders, PCR products, and commercially available plasmid digests, little information is available their use with biological material. In this report, we showed the accuracy of sizing and quantification of endonuclease-digested plasmid DNA. We also showed the feasibility of on-microchip endonuclease treatment of plasmid DNA and sequential analysis as an additional application for DNA analysis. Furthermore, to evaluate the possibility of microchip electrophoresis for biological application, the results of the examination of blood sugar in human plasma and mitochondrial membrane potential were shown.

抄録全体を表示

It is difficult to estimate path loss for land mobile radio using a single path loss model such as diffraction model or Okumura model individually when mobile radio is utilized in widespread area. Furthermore, high accuracy of the path loss estimation is needed when the radio system is digitized because degradation of CNR due to interference deteriorates communications.
In this paper, conventional path loss models, i.e. the diffraction model, Okumura model and two-ray model, were evaluated with 400 MHz land mobile radio field measurements, and a method of improving path loss estimation by using each of these conventional models selectively was proposed. The ratio of error between -10 dB and +10 dB for the method applying the correction factors derived from our field measurements was 71.41 %, while the ratios for the conventional diffraction and Okumura models without any correction factors were 26.71 % and 49.42 %, respectively.

抄録全体を表示

This paper presents a novel common-source active clamped complex type converter. This converter is the intermediate isolated bus converter for the distributed power supply system in telecommunications equipment. Using active clamped circuits, the switching loss and switching noise can be reduced by means of the soft switching techniques. By adding an auxiliary winding to the transformer, proposed converter is a common-source type that is direct connection of sources of the two MOSFET switches. As a result, the pulse transformer becomes unnecessary, and the drive circuit is simplified. In the experiment, at 48V ratings input voltage, 36∼72V world wide input voltage, and 12V output voltage, the ZVS operation is performed on main switch and auxiliary switch, and highest efficiency 92.7% is obtained.

抄録全体を表示

This paper proposes an improved method to detect a crack of drain. The conventional method tends to fail to detect a crack where its direction is changed. The proposed method solves this problem by smoothing structures of crack. A crack has a global direction in large scaled background structures. Therefore the smoothing process to the direction of a crack is supposed to be useful for reducing noise structures without the influence to crack structures. It makes the continuity of cracks improved, and helps the crack detection method to obtain superior results. The two processes are repeated in the proposed method: one is the crack detection process and the other is the noise-reducing process. The experimental results show that the proposed method is useful for improving the detection rate of the crack pixels in comparison with the conventional method.

抄録全体を表示

In this paper, a new H_∞ controller reduction method are proposed to preserve the H_∞ property using frequency-weightings. It is necessary to consider decreasing degradation of H_∞ property for H_∞ controller reduction. It is well known that all H_∞ controllers are represented by free parameters which are stable and bounded. In the paper, frequency-weightings are given to stabilize the free parameter, and low order controller is provided by using frequency-weighted balanced technique. Some numerical examples are illustrated to show effectiveness of our method.

抄録全体を表示

This paper describes the experimental evaluation of a cooperative distance learning method, which can be utilized on the narrow-band Internet. In this method, students of group-learning perform a series of study a couple of times, which create an on-line report, communicating through the chat about given theme. they try to gain improvement in the study effect with higher cooperative attitude. Teacher gives a short lecture at the first stage, and then gives supplementary explanation after grasping the degree of comprehension of students at the middle stage of the study. Teaching materials are distributed to students' PCs beforehand and the lecture could be carried out on the narrow-band environment by transmitting the commands. The teacher analyzes students' communication logs and gives advice for the next study. This paper describes the result of the evaluation of the proposed method by carrying out simulated installation of the environment within the campus supposing a trial of cooperative distance learning in overseas desert circumference area environment.

抄録全体を表示

This paper concerns a DC-DC converter control. In DC-DC converters, there exist both continuous components such as inductance, conductance and resistance and discrete ones, IGBT and MOSFET as semiconductor switching elements. Such a system can be regarded as a hybrid dynamical system. Thus, this paper presents a dc-dc control technique based on the model predictive control. Specifically, a case in which the load of the dc-dc converter changes from active to sleep is considered. In the case, a control method which makes the output voltage follow to the reference quickly in transition, and the switching frequency be constant in steady state. In addition, in applying the model predictive control to power electronics circuits, the switching characteristic of the device and the restriction condition for protection are also considered. The effectiveness of the proposed method is illustrated by comparing a conventional method through some simulation results.

抄録全体を表示

A shunting schedule in a railroad depot consists of instructions to allocate or move train-units in the field. In this paper, we propose a scheduling method which can reconstruct solution in response to various changes in operational conditions. Under classification of train-units to be re-scheduled into two sets; one is a group of having invalid schedule (ISU) and another is a group of having valid schedule (VSU), the method is escalating the re-scheduling target by adding ISUs to a set of VSU and repeatedly solving a partial problem of the target until all the unit is processed. Based on the mathematical model which formalizes the problem as a kind of Flexible Job Shop Scheduling Problems (FJSSP), the partial solution can be derived by an algorithm which uses Constraint Programming (CP) with domain-oriented heuristics. Being evaluated on some test cases, it is showed that the proposed method can find a reasonable solution in a practical time while suppressing the differences from the original schedule.

抄録全体を表示

We propose applying the EDI system that is based on centralized database and supports conversion of code data to the meat industry. This system makes it possible to share exchange data on beef between enterprises from producers to retailers by using Web EDI technology. In order to efficiently convert code direct conversion of a sender's code to a receiver's code using a code map is used. This system that mounted this function has been implemented in September 2004. Twelve enterprises including retailers, and processing traders, and wholesalers were using the system as of June 2005. In this system, the number of code maps relevant to the introductory cost of the code conversion function was lower than the theoretical value and were close to the case that a standard code is mediated.

抄録全体を表示