Slit Type Research Articles

OS1529 ガラスセラミックスの疲労き裂進展の超音波音速による検討

In order to study the effect of the interaction and coalescence of multiple surface cracks by slit type surface crack on static fatigue behavior of brittle materials such as glass and ceramics, the various slit length were introduced on the surfaces of plate specimens of glass ceramics by scriber. Where, glass ceramic material with crystal grain size of about 0.05μm was used. It was found that the time-to-failure for a given applied stress significantly decreased with a increase in the distance of the slit length. Furthermore, the fatigue crack propagation was examined by ultrasonic testing. As the result, the ultrasonic velocity of transversal wave decreased with the progress of loading time.

Sediment Dynamics in Tenryu River Upper Reaches and its Future Theme

The Tenryu River Upper Reaches River Office has carried out many investigations to reveal hydrological process and sediment discharge of Tenryu river upper reaches actually. We have placed the sediment transport observation facility in Yotagiri River that is a sediment discharge measurement device by the method to gather sediment discharge directly. It became clear that the tendency that quantity of sediment discharge increases after outbreak of debris flow temporarily and tapers after that, and sediment which flowed down at Bouzudaira consisted of about 50% silt, about 40% sand, and about 10% pebbles. It is necessary for us establishing of the ruled about repairing to slit type, and management of deposit of sabo dam based on the knowledge about sediment movement properties in the Yotagiri River.

CFD analysis of fin tube heat exchanger with a pair of delta winglet vortex generators

Among tubular heat exchangers, fin-tube types are the most widely used in refrigeration and air-conditioning equipment. Efforts to enhance the performance of these heat exchangers included variations in the fin shape from a plain fin to a slit and louver type. In the context of heat transfer augmentation, the performance of vortex generators has also been investigated. Delta winglet vortex generators have recently attracted research interest, partly due to experimental data showing that their addition to fin-tube heat exchangers considerably reduces pressure loss at heat transfer capacity of nearly the same level. The efficiency of the delta winglet vortex generators widely varies depending on their size and shape, as well as the locations where they are implemented. In this paper, the flow field around delta winglet vortex generators in a common flow up arrangement was analyzed in terms of flow characteristics and heat transfer using computational fluid dynamics methods. Flow mixing due to vortices and delayed separation due to acceleration influence the overall fin performance. The fin with delta winglet vortex generators exhibited a pressure loss lower than that of a plain fin, and the heat transfer performance was enhanced at high air velocity or Reynolds number.

The microstructure of highly-oriented graphite tape prepared from mesophase pitch by melt-blowing

A highly-oriented continuous carbon/graphite tape was prepared from a coal tar-based mesophase pitch by melt-blowing using a slit type nozzle. The average thickness and width of tape were ca. 20μm and 7.2mm, respectively. The molten precursor pitch was continuously extruded through the slit nozzle to produce a pitch tape along the drawing direction. The tape was oxidized, carbonized and graphitized. The micro area X-ray diffraction revealed that the carbon layer planes were oriented parallel to the tape surface indicating a strong anisotropy. The orientation was greater in the tape drawing direction than in the tape width direction, and also in the center area than in the edge area. The mechanical properties were higher than those of conducting polymers, but lower than those of carbon fiber with lower elastic modulus grade.

The influence of nozzle throat length on the resolution of a low pressure impactor—An experimental and numerical study

This study investigates the effect of the nozzle throat length on the resolution of the low pressure impactor (LPI). Two basic nozzle geometries, rectangular slit and round nozzle with 25nm cutpoint were investigated both experimentally and by numerical simulation. A new impactor stage with variable nozzle throat length and jet-to-plate distance was designed, built and tested. The impactor was calibrated at four different configurations with monodisperse dioctyl sebacate (DOS) aerosol. A very good agreement between the simulated and the experimental resolutions and cutpoints were found. The main conclusions are that (a) the length of the nozzle is a crucial parameter affecting the resolution and (b) it is possible to achieve a better resolution with a rectangular slit type impactor than with a round nozzle type LPI. The best observed resolution was achieved with the slit type LPI with a nozzle throat length to width ratio of only 0.33. Compared to similar cutpoint impactor stages of commercially available LPIs, the resolution of the new stage is by far the highest.

Mo1253 Development of a Slit & Hole Type Endoscope Hood With Additional Functions for More Reliable Diagnosis and Safer Treatment

Endoscopic submucosal dissection (ESD) has many advantages, such as the possibility of conducting curative resection en bloc, even in the case of large lesions, so long as appropriate preoperative diagnosis has been made. Most of the complications encountered in patients undergoing ESD were attributable to inadequate securing of the visual field. Therefore, it would appear that securing a satisfactory visual field is essential for the appropriate diagnosis and the safe conduct of ESD.

Young-Type Interference for Scattering of Fast Helium Atoms from an Oxygen Covered Mo(112) Surface

In studies on two structures of oxygen adsorbates on Mo(112), we demonstrate the potential of fast atom diffraction to derive the surface unit cell size and its symmetry. Helium atoms with energies of 1-2 keV are scattered from an adsorbate covered Mo(112) surface along low indexed surface directions under grazing angles of incidence. From the observed diffraction patterns, the lateral periodicity of the surface structures is derived. In addition to the periodic lattice, information on the structure within the unit cell can be obtained from double slit type of interference.

Thermal conductance in a two-slit quantum waveguide

Using the scattering-matrix method, we investigate the thermal conductance in a two-slit quantum waveguide at low temperature. The results show that the total thermal conductance decreases monotonically with temperature increasing. Moreover, we find that the behaviours of the thermal conductance versus temperature are different for different types of slits.

The Pyrolysis Characteristics and Pore Structure of Oil Shale of Different Densities

This study has been undertaken to provide an insight into the proximate and ultimate analysis, mineral matter distributions, pyrolysis characteristics and pore structure of three density fractions of Huadian oil shale. XRD analysis shows that the major phases in oil shale of different densities are present as clays, quartz and calcite. Low-density pulverized oil shale predominantly contains organic matter and a small amount of mineral matter while high-density pulverized oil shale contains an abundance of mineral matter. The difference is that the former contains mainly internal mineral matter, but in the latter a large quantity of excluded mineral matter predominates. The pyrolysis curves of oil shale of three densities indicate that the light density fraction assumes a most intense pyrolysis and the weight loss, and the decomposition rate becomes ever weaker with an increase of density in the range of 250–550 ̊C. Clays have a catalytic effect on the reactivity of oil shale pyrolysis, causing the degradation of the medium and high fraction to start at a lower temperature. Pore structure of oil shale was measured by using a N2 isothermal adsorption/desorption method. The pore shapes of oil shale of different densities all present slit types. The pore volume and BET surface area of the medium density fraction is higher than that of the light and high density fraction.

OS2107 ガラスセラミックスの静疲労特性に及ぼすスリット型表面き裂と結晶粒径の影響

In order to study the effect of the interaction and coalescence of multiple surface cracks by slit type surface crack on static fatigue behavior of brittle materials such as glass and ceramics, the various slit length were introduced on the surfaces of plate specimens of glass ceramics by scriber. Glass ceramics used for the experiment is a N-0(about 0.05μm grain size) and N-11(about 1μm grain size) material. It was found that the time-to-failure for a given applied stress significantly decreased with a increase in the distance of the slit length. However, the static fatigue life does not lower in case of the long slit length in the N-11.

Aspectos morfológicos da cérvice de ovelhas

A principal barreira para a aplicação da inseminação artificial transcervical é a anatomia cervical aliada à baixa viabilidade e sobrevida do sêmen ovino congelado. Assim, este experimento teve como objetivo estudar a morfologia da cérvice de ovelhas. Para tal, foram adquiridas, em matadouro, 81 peças do trato reprodutor de ovelhas, nas quais se avaliou a morfologia cervical, segundo as seguintes características: tipo de óstio cervical, mensuração do tamanho da cérvice, integralidade e interdigitação entre os anéis das pregas cervicais, tamanho e características macroscópicas dos ovários (folículos e corpo lúteo) e tempo da passagem do aplicador de sêmen pela cérvice. Foi identificada maior frequência do tipo liso de abertura da cérvice e integralidade e interdigitação dos anéis grau II. O tempo de passagem do aplicador pela cérvice foi em média de seis minutos e 15 segundos, sendo que o corante aplicado se difundiu por todo o canal, atingindo o útero na maioria das ovelhas. A média do diâmetro da abertura cervical foi de 0,68cm e o comprimento cervical de 4,4cm. A atividade folicular ovariana foi encontrada em 75% das fêmeas. Foi possível estabelecer várias correlações entre as variáveis. Conclui-se que o tamanho da abertura cervical sofre influência estrogênica, e o tipo liso de abertura cervical, o grau III de integralidade e interdigitação dos anéis e o maior comprimento da cérvice foram associados à maior dificuldade de passar o cateter no lúmen cervical.

Stripping of acetone from isopropanol solution with membrane and mesh gas–liquid contactors

Stripping of acetone from isopropanol utilizing nitrogen as a sweeping gas was conducted in gas/liquid contactors with slit type microchannels and containing flat sheet, metal and Teflon tortuous pore membranes or microfabricated metal meshes with straight pores. The contactor consisted of parallel metal plates, gaskets, and the membrane or the microstructured mesh so that passages for gas and liquid phases were formed. These slit type microchannels were 200 μm thick for both gas and liquid phases. All the membranes/meshes were wetted by the isopropanol solution. Breakthrough of one phase into the other was successfully described if contortion of the gas/liquid interface was considered at the pore ends. Various conditions during acetone stripping were investigated such as membrane type, gas and liquid flowrates and inlet acetone concentration. A contactor employing a Micro-Etch metal mesh with 76 μm openings and thickness of 50 μm offered the lowest mass transfer resistance and resulted to the best acetone stripping performance. The separation efficiency increased by increasing the gas/liquid flowrate ratio, but was not affected when increasing the inlet acetone concentration. Good agreement between the experiments and an one-dimensional model with no adjustable parameters was observed.

THE POSSIBILITY OF REAL-TIME MEASUREMENT FOR AIRBORNE BACTERIA CONCENTRATION IN INDOOR ENVIRONMENT

Traditional method for measuring airborne bacterium is based on two procedures called sampling and incubation. Sampling normally involves drawing a sampler from an air stream or room by means of instruments based on impaction, liquid impingement and filtration. Incubation of agar plates typically requires several days. Though the traditional methods can identify the species of microorganisms, they can't obtain any information about suspended viable particles in real time.The technology for real time detection of the presence of suspended viable particles was developed. In order to verify the performance of a new type measurement IMD (Instantaneous Microbial Detection, Bio Vigilant, Inc.), which is used to measure the concentrations of suspended particles with different size distribution based on optical technology and can simultaneously determine whether each particle is inert or biologic in real time. Not only laboratory tests by using latex particles (as a substitute for inert particles) and fluorescence particles (as a substitute for biologic particles) were conducted, but measurements on airborne microbes in six hospital waiting rooms, one office, and one residence were conducted by using an IMD and MG sampler (culture-based, slit type, Mattson-Garvin Inc.) in parallel.Significant correlations between suspended bacterial concentration and biological particle concentration were obtained. The measurement results pointed out that the IMD can measure the fluctuation patterns of suspended bacterial particles in field environments in real time.

Field Application of the Slit Type Coastal Structures under Waves and Currents

Redevelopment of the domestic small fishing ports is being started in earnest by applying the environmentally friendly technology in order to attract tourists. For the purpose of improving water quality in the harbor, selection of breakwater type might have the priority to secure calmness and stability. Therefore, this study is to determine the hydraulic characteristics of reflective ratio, installation efficiency and stability of the special type of blocks through the hydraulic model experiment. The results were introduced to analyze for the effect of infield construction work through numerical analysis. Gujora, a small fishing port in southern Korea, is affected by the waves of SSE, S, SSW direction and strong tidal currents. The results of applying cylindrical slit block show that stability of the blocks and harbor calmness were secured. Considering that the pass rate of a long period wave is still excellent, the primary objective of wave control and the secondary objective of improving water exchange are satisfied simultaneously.

앵커볼트 체결 Slit형 강판 보강 RC보의 전단거동에 관한 실험적 연구

기존 구조물에서 RC보는 여러 가지 이유로 불충분한 전단에 대한 문제에 직면하게 된다. 전단내력이 부족한 RC보의 전단 보강방법으로 강판이 널리 사용되고 있다. 본 연구에서는 앵커볼트가 체결된 경사, 수직 슬릿형 강판의 표면부착에 의해 전단보강된 RC보에 대한 실험을 하였으며, 여러 형태의 앵커볼트 체결 슬릿형 강판으로 보강된 RC보에 대한 전단보강효과, 파괴모드 및 전단내력을 평가하는 것을 연구의 목적으로 하였다. 실험의 변수는 앵커볼트가 부착된 슬릿의 폭, 간격, 경사각 및 수직 길이로 하였다. 연구 결과, 에폭시 부착과 볼트 체결로 보강된 슬릿형 강판 실험체의 파괴 유형은 최대하중 시 전단파괴 모드로 나타났다. 휨균열은 보의 인장측에서 최초로 발생하였으며, 경사 균열은 전단스팬에서 발생하였다. 최종적으로 에폭시 부착과 볼트 체결로 보강된 슬릿형 강판에서의 급격한 박리현상은 지연되었으며, RC보의 본체로부터 완전하게 분리 되지는 않음을 알 수 있었다.

Slit effect of common ground patterns in affecting crosstalk noise between two parallel signal traces on printed circuit boards

AbstractIt is well known that electromagnetic (EM) disturbances in vehicle‐mounted radios are mainly caused by conducted noise currents flowing through wiring harnesses from vehicle‐mounted printed circuit boards (PCBs) having common ground patterns with slits. To evaluate the noise current outflows from PCBs of this kind, we previously measured noise current outflows from four types of simple three‐layer PCBs having two perpendicular signal traces and different ground patterns with or without slits, and showed that slits on a ground pattern allow conducted noise currents to flow out from PCBs, while the levels for the symmetric slit ground type are smaller than in the case of two asymmetric slit ground types. In the present study, to further investigate the above finding, we fabricated six types of simple two‐layer PCBs having two parallel signal traces and different ground patterns with and without slits, and measured the crosstalk noise between the traces. We found that the ground patterns with the slits perpendicular to the traces increased the crosstalk noise levels, which were 19 to 42 dB larger than those for the ground pattern with no slits, while the ground patterns with the slits parallel to the traces were able to reduce the noise levels, which were slightly smaller (by 2.5 to 4.5 dB) than in the case of the no‐slit ground pattern. These results were confirmed by FDTD simulation, and were also qualitatively explained by means of an equivalent bridge circuit model that we previously proposed. © 2010 Wiley Periodicals, Inc. Electron Comm Jpn, 93(10): 19–24, 2010; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/ecj.10287

W1526: Development of an Endoscope Hood for Safer and More Reliable Endoscopic Submocosal Dissection: A Slit & Hole Type Hood and an Oblique Broad-Angle ESD Hood

Endoscopic submucosal dissection(ESD) has many advantages, such as the possibility of conducting curative resection en bloc, even in the case of large lesions, so long as appropriate preoperative diagnosis has been made. Most of the complications (perforation and bleeding) encountered at our hospital in patients undergoing ESD were attributable to inadequate securing of the visual field during the operation. Therefore, it would appear that securing a satisfactory visual field is essential for the appropriate diagnosis and the safe conduct of ESD.

Development and effectiveness of a slit type--fenestrated tracheostomy tube in patients with respiratory muscular disease

Development and effectiveness of a slit type--fenestrated tracheostomy tube in patients with respiratory muscular disease

An Overload Prevention Mechanism in a Load Cell Using an H-slit Type Double Beam

Overload prevention is important for a force sensor in order to avoid fatal damage due to unexpected external force. Until now, most of the proposed mechanisms for this purpose prevent the damage to the sensor by using a screw and a straight pin. Few reports on the utility of these mechanisms have been published. In our previous work, we proposed a unidirectional force sensor based on an H-slit type parallel beam structure. The H-slit beam structure is a part of a force sensor and it can perform as an overload prevention mechanism without any additional mechanical parts. In this paper, we verify the utility of the H-slit type beam based overload prevention mechanism. Besides, based on the verification result, this paper proposes a new slit type beam overload prevention mechanism.

424 低カロリーガス燃料における水平噴流放射状拡散火炎の火炎挙動と安定限界に関する研究(エネルギー有効利用(2))

When the quantity of petroleum fuel resources is decreasing, substitutes for conventional petroleum fuel are needed. Therefore, there are various species of renewable fuel such as residual fuel of emission from the fuel cell and biomass gas. Now, there are assignments that the low-calorie fuel and the biomass gas are utilized for renewable energy. Various species of renewable fuel such as biomass gas which includes mainly methane are widely used for substitute fuel. Holding the flame is an important pole in the burning technique for taking out the energy effectively. It is found that the parameters for holding the diffusion flame are fuel velocity, co-flowing velocity, nozzle diameter (curvature), type of burner nozzle and condense of the fuel. The objective of the present study is to get further understanding of lifting/blow-off in the radial horizontal jet diffusion flame. The radial horizontal jet diffusion flame is formed by using slit type of nozzle. The simulation of the numerical computation by using PHOENICS is compared with experimental data for the flame structure on which flame holding of the horizontal jet diffusion flame depend. It is to make clear of the behaviors and the stability limit of the horizontal jet radial diffusion flame.