Repository of NNCT (Nagano National College of Technology)
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自動車用0.23%Cホットスタンプ材のYAGレーザ溶接性
Get PDFThe effects of YAG laser welding conditions on mechanical properties of ultrahigh strength 0.23C-0.19Si-1.29Mn-0.013P-0.001S-0.052Al-0.024Ti-0.21Cr-0.003B (mass%) hot-formed (22MnB5) steel were investigated. Tensile tests have been conducted for laser butt welded joints obtained from the combination of the same steel. The tensile properties were affected by the welding speed and the pulse energy. The joint penetration was obtained by using the energy of 15.2 J/pulse (mean power: 685 W, pulse frequency: 45Hz, pulse width: 3.8ms) and the welding speed of 250 mm/min. It was concluded that the YAG laser weldability of the 22MnB5 steel was ascribed to the weld joint formation. The joint strength decreased by about 500 MPa, compared with the tensile strength of base material, and welded efficiency was 75%, because of notch effect and crack initiation at the laser weld of welded heat affected zone (HAZ) and the base material.departmental bulletin pape
長野高専校舎における電力使用状況の分析
Get PDFThis paper described the analysis result of the electric power consumed in campus of Nagano National College of Technology, and the electricity-saving method and its effect and its effect in college. Change of the electric power of campus was measured with the demand monitoring system and Wattmeter. The key points of this paper ware as follows: (1) electric power and electric power consumption became the maximum in January; (2) in winter, electricity demand increased to the morning which is conducting graduation research and an experiment, and after school; (3) the power-saving effect was verified a lunch break and after school, and they had an effect.departmental bulletin pape
パッシブ手法による教室の温熱環境の快適性に関する研究
Get PDFIn this paper we deal with the amenity of the thermal environment in the classroom by the passive technique.
Temperature of the exterior wall fell 3 ℃ by Green curtain. When solar radiation shielding with light shield sheet, operative temperature drop 4.1℃. Shielding effect of the blind can be reduced by 20% operating rate of air conditioning. A result of examining the air conditioning energy, reduction of heating energy is more important than cooling energy in cold temperature area, such as Nagano.departmental bulletin pape
街路空間評価意識構造モデルを用いた歩行者優先道路空間のサービスレベル評価
Get PDFThe purpose of this study is to clarify improvements in consideration of road traffic condition of pedestrian space. We executed the investigation concerning the satisfaction rating of the street space by the pedestrian in a transit-mall social experiment of Nagano City. The experiments on the transit-mall was carried out by the Center of Nagano City during consecutive holidays of May,2007,2008 and 2009. First of all, We applied the factor analysis to the satisfaction rating data. Next, the correlation of the satisfaction rating data and the measurement data were clarified. Thirdly, the behavioral trait of pedestrians is extracted by gathering the pedestrian occupation data, which show exact point where pedestrians walked through. We applied the covariance structuer analysis, and were able to clarify the relation between the subconsciousness factor and the pedestrian flow the pedestrian behavior model.departmental bulletin pape
自動車用TRIP鋼板の疲労特性に及ぼすバーリング・タッピングの影響
Get PDFFor the purpose of further improvement on the barring-tapping, in this investigation, the effect of burring and tapping on fatigue characteristics in TRIP sheet steels (TDP steels) were studied.
The chemical composition of the TDP steels used in this study was (0.1-0.4)C-1.5Si-1.5Mn (mass%) steels of cold-rolled sheet steels (thickness: 1.2 mm). These steels after heat treatment were named TDP1 to TDP4. For comparison with TDP steel, the ferrite martensite dual-phase sheet steel (MDP steel) was also prepared. Burring test was performed by a machining center (MC) at cutting feedrate of F=10 mm/min and rotational speed of n=3500 rpm, using plate specimens of 150×50 mm. A bushing was produced by flowdrill of M6 short type (diameter: D=5.3 mm). Tapping test was performed by a MC at F= 20 mm/min and n= 20 rpm after burring.
Burring and tapping tests were measured z-axis loading meter (S) corresponds to thrust and spindle loading meter (T) corresponds to torque, respectively. In addition, we have performed measuring the hardness of the specimen after processing, microstructure observation and fatigue tests.departmental bulletin pape
ハミルトニアン・アルゴリズムによる楽音合成
Get PDFHamiltonian Algorithm (HA) is an algorithm for searching solutions is optimization problems. This paper introduces a sound synthesis technique using Hamiltonian Algorithm and shows a simple example. "Hamiltonian Algorithm Sound Synthesis" uses phase transition effect in HA. Because of this transition effect, totally new waveforms are produced.departmental bulletin pape
高機能性カーボン材料開発のためのナノ構造の顕微鏡と画像処理による評価法の検討
Get PDFTEM techniques progress and samples can be observed atomic level. Selected area electron diffraction (SAD) which is one of the transmission electron microscopy techniques is difficult to apply to nano sized area. 2 dimensional fast Fourier transform (2D-FFT) was used for structural analysis of small area of carbon materials. The 2D-FFT gives comparable result with SAD and useful for nano sized carbon materials. In this study, we try to prove that the 2D-FFT gives comparable result with SAD and useful for nano structured carbons.departmental bulletin pape