Journal of Advanced Science

On the Occurence of Droplet Oscillations During Liquid Jet Disintegration

Günter BRENN

1992 Volume 4 Issue 3 Pages 189-196
Published: September 15, 1992
Released on J-STAGE: February 25, 2010

DOIhttps://doi.org/10.2978/jsas.4.189

JOURNAL FREE ACCESS

Show abstractHide abstract

Experimental investigations of oscillatory droplet deformations during liquid jet breakup are presented. Droplets are produced using a pinhole droplet generator. The droplet diameter is roughly 100μm, and the experiments are carried out using propanol-2. The droplets may be produced under atmospheric or under vacuum conditions. Oscillations occur due to initial deformations of the droplets shortly after their separation from the jet. Oscillatory motions of the fundamental mode and of higher order modes may occur during the disintegration of the liquid jet. The periodical production of the droplets leads to a periodical repetition of the oscillation processes, Therefore, the experimental method allows the observation and evaluation of each phase of the motion under quasi-steady conditions. Oscillation modes dominating the droplet deformations are determined by comparison of observed and calculated droplet shapes. Different regimes of the disintegration process are found to be dominated by different oscillation modes. It could be shown that, besides oscillations of the fundamental mode, oscillations dominated by the first higher order mode may occur due to merging of droplets of different size.

View full abstract

Download PDF (3209K)
INFLUENCE OF VORTEX MOTION ON MAGNETOSTATIC WAVE PROPAGATION IN THE FERRITE-HIGH TEMPERATURE SUPERCONDUCTOR LAYERED STRUCTURE

Natalya I. POLZIKOVA, Alexander O. RAEVSKII

1992 Volume 4 Issue 3 Pages 197-203
Published: September 15, 1992
Released on J-STAGE: February 25, 2010

DOIhttps://doi.org/10.2978/jsas.4.197

JOURNAL FREE ACCESS

Show abstractHide abstract

The influence of the mixed state of type II superconductor on magnetostatic wave (MSW) dispersion and absorption is theoretically investigated. The MSW characteristics are shown to depend on the relationship between the MSW a.c. field penetration depth into superconductor 1, wavelength λ and superconductor thickness b. The former is expressed in terms of an effective conductivity, which is strongly dependent on the d.c. vortex velocity v_o due to a d.c. current. If v_o exceeds the MSW phase velocity, instead of absorption of the wave, we have its amplification. The effect of d.c. voltage generation owing to the dragging of vortices by MSW is also studied.

View full abstract

Download PDF (964K)
A Simple Mean-Field Theory of d-wave Superconductivity

Minoru SATO

1992 Volume 4 Issue 3 Pages 204-206
Published: September 15, 1992
Released on J-STAGE: February 25, 2010

DOIhttps://doi.org/10.2978/jsas.4.204

JOURNAL FREE ACCESS

Show abstractHide abstract

A simple interpolation scheme neglecting doubly occupied states is established between insulating and metallic limits of the t-J model. The equation of motion is linearized by applying the mean field approximation. Self-consistent equations of d-wave superconducting states are given and 2T_c/t as a function of carrier density δ is calculated.

View full abstract

Download PDF (441K)
SIMULATION OF ISOTOPE SEPARATION IN SHEET PLASMA BY ION CYCLOTRON RESONANCE METHOD

K. Kawamura, K. Nanri, T. Tanikawa, K. Sunako, K. Arai, K. Yamauchi, T ...

1992 Volume 4 Issue 3 Pages 207-209
Published: September 15, 1992
Released on J-STAGE: February 25, 2010

DOIhttps://doi.org/10.2978/jsas.4.207

JOURNAL FREE ACCESS

Show abstractHide abstract

The effect of space potential well in sheet plasma on the resonance condition in isotope separation by means of ion cyclotron resonance method is elucidated numerically by computer simulation. It is found that the resonance frequency and minimum rf peak electric field increase monotonously with the increase of peak space potential well of sheet plasma.

View full abstract

Download PDF (374K)
Rapid Measurement of Shape Memory Deformation Behavior Using Peltier Effect Elements

Yasubumi Furuya, Kouyuu Abe, Tsuneo Teshima, Minoru Matsumoto

1992 Volume 4 Issue 3 Pages 210-213
Published: September 15, 1992
Released on J-STAGE: February 25, 2010

DOIhttps://doi.org/10.2978/jsas.4.210

JOURNAL FREE ACCESS

Show abstractHide abstract

The fatigue test device of Shape Memory Alloy wire was developed using the Peltier element of Bi₂Te₃ and Sb₂Te₃ for p type and Bi₃Te₃ and Sb₂Se₃ for n type. The measurements of Ti-Ni-Cu wire and rapidly solidified Ti-Ni and Ti-Ni-Cu were carried out by short cycle time of heating and cooling under stable temperature control. From the experiment, it was concluded that the elongation by plastic deformation caused the fatigue and degradation of Shape Memory Alloy.

View full abstract

Download PDF (422K)
DEVELOPMENT OF OPTICAL PRESSURE SENSOR SYSTEM

Yoshitaka YOSHIZAWA, Takao TSUTAYA, Seiichi NAKAHARA, Toshio KANEKO

1992 Volume 4 Issue 3 Pages 214-216
Published: September 15, 1992
Released on J-STAGE: February 25, 2010

DOIhttps://doi.org/10.2978/jsas.4.214

JOURNAL FREE ACCESS

Show abstractHide abstract

As a method to measure fluid pressure, it is known to detect the displacement of a diaphragm electrically. However we must pay attention to measure the data under the condition of bad environment electrically and take steps to eliminate electrical noise if it is existed.
We conceived of the method to detect the displacement of a diaphragm optically with adopting newly developed our original special filter. We developed optical pressure sensor system using optical fiber for signal transmission lines, and evaluated its ability.

View full abstract

Download PDF (2077K)
THE SPINNING BY RAPIDLY SOLIDIFIED PROCESS OF ABRASIONPROOF Co BASED ALLOYS.

Yukio MIYAGAWA, Ikuo ISHIGURO, Yoshimasa SUZUKI, Zenzo KITAYAMA, Masak ...

1992 Volume 4 Issue 3 Pages 217-222
Published: September 15, 1992
Released on J-STAGE: February 25, 2010

DOIhttps://doi.org/10.2978/jsas.4.217

JOURNAL FREE ACCESS

Show abstractHide abstract

“In-Rotating-Water Spinning” process is a useful technique which can obtain directly the continuous wires having circular cross-section by injecting molten metal jet into a rotating water layer, and further, which can make the crystal grains fine by rapid cooling solidification effect, and improve the mechanial properties.
We applied this method to try the direct wire making of hard and brittle, wear resistant Co-base alloys and the improvement of the mechanical strength.
According to the characteristics of the production method, (1) the apparatus for vertical type spinning in rotating liquid for 0.1-0.3mm diameter and (2) the apparatus for horizontal type spinning in rotating liquidfor 0.3-0.5mm diameter were used.
The kind of coolant is a very important factor, and in the case of this alloy, it was found that sodium carbonate aqueous solution was particularly effective.
The wires obtained by rapid cooling solidification were heattreated (at 1273-1373K for 1h), and the stabilization of the metastable phase and the refining of the crystalline structure were carried out, in this way, the wires having the aimed-at wear resistance and mechanical strength were obtained.

View full abstract

Download PDF (7321K)
PREPARATION OF ULTRA PURE TUNGSTEN

Masayoshi TADA, Mamoru KAWAKAMI, Tomoyuki SAITO, Shinta OHIWA

1992 Volume 4 Issue 3 Pages 223-227
Published: September 15, 1992
Released on J-STAGE: February 25, 2010

DOIhttps://doi.org/10.2978/jsas.4.223

JOURNAL FREE ACCESS

Show abstractHide abstract

The method of Electron Beam Floating Zone Melting (EBFZM) is well known as an effective treatment in refining of metals that has high melting point and reactive properties at high temperature.^{1, 2, 3} However, the sintered tungsten rod contains a great deal of gases.⁴ Thus, degassing is very important process for purification.
In this present work, we refined tungsten rods by method of EBFZM, and estimated a purity of tungsten rods by measurement of Residual Resistivity Ratio (RRR)^{5, 6} and micro Vicker's hardness.⁷ As a result, it was confirmed as follows.
1. Annealing was very effective treatment in degassing of tungsten rods.
2. EB Gun's fast travel brought about a difference in refining conditions between rod's inside and one's surface, resulting in the formation of gaseous pools in rod's inside.

View full abstract

Download PDF (2440K)
The production of a Functional Gradient Material by Ordinary P/M Technique

Ichiro Sogaishi, Takeshi Nagai, Noboru Matsunaga

1992 Volume 4 Issue 3 Pages 228-234
Published: September 15, 1992
Released on J-STAGE: February 25, 2010

DOIhttps://doi.org/10.2978/jsas.4.228

JOURNAL FREE ACCESS

Show abstractHide abstract

In the technique of producing functional gradient materials, made with different specific layers, a lot of intense investigations were done until now, especially in layers contactiong a surface and the control of interfaces.
In our work, we tried to make FGM with a conventional method.
The procedure is as follows:
(1) fabrication of a porous bulk with a density gradient.
(2) filling this bulk with a specific material. In the first step, we try to figure out the possibility of producing such a density gradient porous bulk.

View full abstract

Download PDF (9763K)

Register with J-STAGE for free!