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A piezoelectric cantilever was manufactured using a PMN-PZT thick film for an electric harvesting device. In order to find better properties, we manufactured the piezoelectric cantilever in two forms (bi-morph and triple-morph); then, the bi-morph cantilever and the triple-morph cantilever were compared as to electric micro power. The generation characteristics were investigated at various frequencies, load resistances, and masses. The output power of the bi-morph piezoelectric cantilever showed a maximum value at 0.25 g mass at 197 Hz, and the triple-morph piezoelectric cantilever showed a maximum at 0.25 g mass at 154 Hz. The piezoelectric cantilever output voltage increased with the increasing load resistance, and the output power quality was investigated by changing the load resistance, the mass, and the frequency. The bi-morph piezoelectric cantilever‘s output power at 33 k , 0.25 g, and 197 Hz was 0.23 mW at 2.75 Vrms, and the average micro power from the triple-morph piezoelectric cantilever was 0.432 mW at 6.57 Vrms and 154 Hz.
In this study, multilayer piezo stack transformers for switching mode power supply (SMPS) application were manufactured using 0.01Pb(Ni1/3Nb2/3)O3 - 0.08Pb(Mn1/3Nb2/3)O3 -0.91Pb(Zr0.505Ti0.495)O3 (PNN-PMN-PZT) ceramics. The voltage ratio of a multilayer piezo stack transformer showed a maximum at the resonance frequency of the input and then increased with increasing load resistance. The efficiency of the multilayer piezo stack transformer showed its highest value at around the matching load. The output power increased with increasing input voltage. The temperature of the multilayer piezo stack transformer increased with increasing output power and load resistance. The manufactured multilayer piezo stack transformer could be used up to 5W at a resonance frequency of 70.25 kHz for SMPS application because the temperature rise from room temperature is believed to about 20 ℃ and because the transformer is electrically stable. The newly-developed ring-dot-type step-down multilayer piezo stack transformer shows possible applications as SMPS for electronic power sources with excellent input-to-output properties.
In this research, the electrical properties of a ring-type step-down stack piezoelectric transformer with pure Ag electrodes were investigated using simulated models and practical experiments. A prototype of the transformer was fabricated, 30 mm in diameter and 3 mm in total thickness, using a piezoelectric ceramic. In this design, the isolated gap between the input and the output sections was 1.5 mm, and a no-printed area existed. The 3D model with a size corresponding to the experiment was created in the simulation. The voltage step-down ratio and the power increased with increasing input voltage at resonant frequency. In the simulation, the potential distribution in the model was described, and the potential at any node could be shown. At an output power of 5 W, the transformer characteristics across a 150 Ω load were found to be an input voltage of 100 V and a temperature rise of less than 20 ℃ from room temperature.
Phragmites australis, Zizania latifolia and Typha angustifoliawere grown in mono culture in order to compare growth (relative biomass increase rate), variation of photosynthetic pigment (total chlorophyll, Chl a, Chl b and Chl a/Chl b) and effectiveness of nutriment removal in 15‰ NaCl-salt solution or processed-leachate (salinity 19.6‰) from sanitary landfill sites. The relative biomass increase rate of P. australis was significantly higher than Z. latifolia and T. angustifolia. In the case of P. australiswere 178 %, 148 % and 157 %, respectively. Also, in 15 ‰ NaCl-salt solution treatment, the relative biomass increase rates of P. australis increased as folows; 161 % (above-part), 183 % (rhizome) and 112 % (root). Total chlorophyll contents increased significantly in the leaves of P. australis and Z. latifolia grown in 15 ‰ NaCl-salt solution and processed-leachate. Among three macrophytes, P. australis was evaluated as most effective macrophyte for the biological retreatment of processed-leachate from sanitary landfill sites.
In this study, the Hall effect has been studied in n-GaAs samples characterized by V/III growth ratios of 25, 50 and 100 and prepared by metal organic chemical vapor deposition. For the Hall effect measurements, the grown samples were cut to a size of 1×1 cm. The measurements were carried out at room temperature, using Indium contact metal at the four corners of the samples. According to the experimental results, the Schottky effect was not ovservation. Also for the n-GaAs sample of V/III 100 ratio the electron drift velocity was very high. In this study, the Hall effect has been studied in n-GaAs samples characterized by V/III growth ratios of 25, 50 and 100 and prepared by metal organic chemical vapor deposition. For the Hall effect measurements, the grown samples were cut to a size of 1×1 cm. The measurements were carried out at room temperature, using Indium contact metal at the four corners of the samples. According to the experimental results, the Schottky effect was not ovservation. Also for the n-GaAs sample of V/III 100 ratio the electron drift velocity was very high.
Since 2010 when Medvedev visited Kuril islands,the Russian government has increased its interest in the Kuril problem. And plans to develop the Kuril Islands and to increase military facilities were discussed. The governmental plans on Kuril islands were enhanced and realised fully since 2011. As a result of the plans,the social and economic situation of the islands seem to become improved much better. The quality of residents‘ life was significantly improved. Outdated facilities such as water and sanitation, electricity,road paving,hospitals,kindergartens,gymnasium,airports, harbors,and apartments were newly constructed. Concerning the military aspects of the Kuril region,by 2014 two military towns will be constructed and new military weapons will be deployed. Increase and modernization of military force seems not to aim at the Japanese Maritime Self-Defense Force. Because territorial disputes between Russia and Japan since its inception never led to military collision,which seems not to occur in the near future. Problems concerning Kuril islands are obstacles to Russian government’s Northeast Asia strategy. So Russian government wants to settle these problems. A series of words and actions by Medvedev related to the Kuril problems do not necessarily mean turning into a more aggressive policy. In consideration of Medvedev and Putin’5 words and actions,Russian government is sending a warning to ‘Japan,which stubbornly demand to transfer all four islands without any economic compensations. In other words,Russian government wants to attract much more Japanese capital to develop Far East region,which is possible only under condition of the settlement of the territorial dispute. Improvement of the relationships with Japan remains as an important problems by which the Russian government confronted.
The collapse of the USSR bequeathed plenty of problems to the Russian Federation. One of the most important issues is related to the overseas russians in the Commonwealth of Independent States(CIS). To understand this problem we have to know three tensely related issues. First issue is the conditions surrounding overseas russians. Second is the policies of the newly independent states on overseas russians. The last is policies of the Russian Federation on overseas russians. The economic and political situations of the overseas russians are various according to the place of the residence. But few of them enjoy stable life, which was the main reason for Russian Government to engage in the protection of the civil rights and freedom of the overseas russians. Meanwhile, Russian Government wants overseas russians to play a role of a leverage to excercise influence over the countries of the former USSR. With the introduction of the new Civil Law in 2002 favorable conditions for overseas russians disappeared, which was resurrected by the presidential decree in 2006. But whether the decree means that Russian Government intends to exercise influence over the countries of the former USSR is now uncertain.