Influence of the ultrasound (US) on the formation of hydrogen bonds in acrylic acid (AA) and N-isopropylacrylamide (NIPAM) polymer P(NIPAM-co-AA) was investigated. It was expected that the sonic wave led to change the breaking ability of the hydrogen bonds between AA and NIPAM under US exposure. The polymer solutions contained 4g P(NIPAM-co-AA) in 96ml water was used. In the polymer solution, viscosity was measured when B type viscosity meter was used with 6 and 60 rpm rotation after exposure of different frequency (28, 45, 100 kHz) and the power of US (200W). It was found that hydrogen bonds were broken by irradiating the US. As a result, the viscosity of the solution decreased and increased with and without the exposure of US

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Ultrasound (US) has been shown to induce apoptosis and cell lysis in cancer cells. In this 26 study, we report on the potential of using Sonazoid, a new echo-contrast agent, that is chemically more stable and US-resistant hi combination with US in cancer therapy. The biological effects and their mechanisms in the presence or absence of ultrasonic exposure in vitro were investigated. In addition, the impact of the agent on the expression levels of genes responsive to US was studied using global-scale microarrays and computational gene expression analysis tools. Our results show that the combination led to enhanced cell killing in the presence of 1 MHz acoustic field. The apoptosis induction was shown to be mediated by the mitochondrial pathway. The occurrence of US-induced DNA damage was also observed. Despite these findings, the agent at concentrations similar to those clinically used can be considered as well tolerated. Furthermore, Sonazoid enhanced expression of genes that related to apoptosis and are responsive to US, although it alone had almost no effect. These results indicate the potential of Sonazoid for US contrast enhancement as well as the possibility of its use in US-aided therapies.

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Titanium dioxide (TiO_2) is known as sonocatalyst which generate hydroxyl radicals when the ultrasonic (US) is irradiated to TiO_2 (TiO_2/ US method). In this study, we investigated the cell damage effect and antitumor effect by the combination of ultrasonic irradiation and TiO_2 nanoparticles that is modified with preSl/S2 protein for targeting HepG2 cells. For irradiating of US to the preS1/S2-TiO_2 nanoparticles incorporated HepG2, cell injuring efficiency was evaluated by Trypan blue dye exclusion test. As a result, the cytostatic activity was acquired when irradiated at 1MHz, 0.1 W/ cm^2, 30 second, 50% duty in the presence of TiO_2 nanoparticle modified with preS1/S2 protein. This cytostatic activity was observed at 24 hour after US irradiation, and this effect was significantly enhanced as time elapsed. Also, antitumor effect by TiO_2 / U.S. method in vivo was evaluated. When ultrasonic irradiation was performed by the frequency of 3 times per week, and the irradiation conditions of 1 MHz, 1 W/cm^2, 1 min, no significant damages to the mice was ovserved. These irradiation condition revealed the antitumor effect significantly. Moreover the further research, such as the examination of the irradiation conditions of ultrasound, injection amount of TiO_2 nanoparticles and the specific binding ability to HepG2 tumor after i.v. injection, are proposed.

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Recently, technique for the degradation of hazardous organic compounds has been investigated, and ultrasound has been investigated as one of the techniques for degradation of hazardous organic compounds. In this study, indirect ultrasonic irradiation method was applied to degradation process of phenol, the model hazardous organic compound. We focused on the effects of the relationship between ultrasonic transducer and reactor on degradation of phenol, radical generation and ultrasonic power inside the reactor. The degradation rate of phenol was influenced by reactor's position. And, the effect of reactor's position on the degradation rate overlapped with its effects on chemical efficiency estimated by KI oxidation dosimetry and ultrasonic power measured by calorimetry. The degradation rate of phenol was improved by TiO_2 particle addition, because the particle's surface area was considered to be working for OH radical formation by ultrasonic irradiation. On the other hand, the reactor's position influenced the degree of the improvement of the decomposition conversion by particle addition. When the particles are dispersed well, the surface area of particle is considered to be large. However, when a part of particles are agglomerated, the surface area of particle is considered to be small. Therefore, it is supposed that the dispersion condition of TiO_2 particles in the sample solution is influenced bv reactor's position.

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To enhance the particle agglomeration in a precipitation process, 2.0 MHz ultrasound was irradiated to suspension of calcium phosphate. Only with 1 minute irradiation, the ultrasound triggered particle growth, and enhanced sedimentation. During the ultrasonic irradiation, floe of particles grew progressively. The flocculated particles rapidly settled down under gravity after stopping the irradiation and the suspension separated into layers such as clear, cloudy and dense. Progress of the separation with time was expressed by the normalized height of the boundaries. Effects of ultrasonic power on the particles agglomeration were examined. The irradiation with high power was found to be effective. There was a threshold power for the agglomeration. Appearance of the surface and inside the suspension changed significantly depending on the power below and above the threshold. Visually observable bubbles appeared and moved around at the power above the threshold. Ultrasonic particle agglomeration is relating with physical effects of ultrasound and the possible mechanisms are particle acceleration by vibration, radiation force under standing wave, acoustic streaming, jet flow induced by the bubble collapse and microstreaming around vibrating bubbles. The investigation suggested that microstreaming and acoustic streaming probably contribute to the agglomeration.

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Lithium iron phosphate has attracted attention as a promising cathode material for lithium ion battery, because of its less expensive, abundance. However, the battery capability of this material is at present limited by its low electronic conductivity and low lithium diffusion rate. In order to improve the poor diffusion of lithium ions and the low electronic conductivity, mainly two possible approaches have been studied. One is to increase the surface area of active materials which can reduce the ion-diffusion pathway, and the other is to deposit conductive carbon layers on the surface to improve electronic conductivity. Since the surface area is dependent on the particle size of LiFePO_4, the synthetic method is very important to control the particle size. In this study, Olivine-type LiFePO_4 was prepared via a Sonochemical reaction to gain the fine particles. LiOH・H_2O, (NH_4)_2HPO_4 and FeSO_4・7H_2O were used as the starting materials. An Alcohol was added to the solution of the raw materials. When ultrasonic irradiation upon an alcohol, it is so effective for prohibition of conversion from Fe^<2+> to Fe^<3+> in the solution without reducing agent. The precipitate prepared from the solution gave fine particles of LiFePO_4 after calcination. The LiFePO_4 powders obtained was of homogeneity and globular structure with sub-micron particle sizes. In addition, we examined the application of CNF as a conductive carbon to improve the electronic conductivity of LiFePO_4.

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Copper formate hydroxide particles were sonochemically synthesized, and morphology of the particles were largely influenced by composition of the original solutions. Three kinds of microsized particles were obtained: rhombic, star-shaped and rectangular particles. Element analysis of the particles proved that all particles have the identical chemical component CH_2Cu_2O_4, that have never reported previously. Infrared spectra of the particles indicate the existence of HCOO group and Cu-OH. Therefore, the particles obtained could be expressed as Cu(HCOO)_2・Cu(OH)_2-2CuO. From the PXRD patterns, it was shown that all these particles have metal hydroxide having layered structures similar to Cu_2(OH)_3(NO_3),Cu_2(OH)_3Cl. PXRD patterns showed that the crystal structure of the rhombic particles and the star-shaped particles are identical, while that of the rectangular particles is different from other two particles. Magnetic susceptibility was measured by SQUID: the rhombic particles showed antiferromagnetism (2〜13 K and 25〜300 K), ferromagnetism (13〜20K) and paramagnetism (20〜25K) depending on the temperature. Whereas, the rectangular particles showed only antiferromagnetism (2K〜300K).

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Enzymatic hydrolysis of cellulose produces glucose. However the enzymatic saccharification of woods is low efficiency and slow reaction rate because the cellulose in wood has complex structure. In this study, the effect of ultrasonic irradiation on enzymatic saccharification of wood biomass was examined. Ultrasound was irradiated wood powder and enzyme (cellulase) in solution during saccharification by using horn-type transducer at 20 kHz. The concentrations of total sugar and glucose after enzymatic saccharification with ultrasound were higher than those without ultrasound. The cellulase consists of endoglucanase, cellobiohydrolase and β-glucosidase. The activities of endoglucanase, cellobiohydrolase and β-glucosidase increased by ultrasonic irradiation. From these data, it is considered that the ultrasound physically breaks wood surface and accelerates contact number between cellulase and cellulose.

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We investigated the relation between the sonochemical efficiency and the liquid flow under sonication in a rectangular sonochemical reactor with and without a mechanical stir. We observed ultrasound field in the rectangular sonochemical reactor with the sheeted laser and velocity profiles within the rectangular sonochemical reactor by LDV (Laser Doppler Velocimetry). The reactor consisted of the 490 kHz transducer and the rectangular glass cell of 20 cm×20 cm×65 cm. The experimental set up was shown in Fig.l. All measurements were carried out at room temperature. The increase of revolution of a stir leads to complex asymmetrical cavitation behavior and fluid convection in the reactor. With a mechanical stir, the direction of the flow changed and the average magnitude of the flow velocity was increased remarkably. As the revolution increased, the region showing the sonochemical luminescence expanded and sonochemical efficiency increased up to about 2 times than the value obtained without a mechanical stir. From these results, the suitable construction of the flow field leads to enhance the sonochemical efficiency.

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In our previous work, we developed a novel methoxylation electrosynthesis using a thin-layer micro-flow cell without added electrolyte. However, a problem of low current efficiency still remains. In this work, to improve current efficiency, the part of the micro-flow cell was dipped in the ultrasonic cleaning bath for introducing ultrasonic agitation into the cell. By using this system, the current efficiency in preparative scale of the electrochemical methoxylation of furan was actually improved.

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The drive method of ultrasonic transducers is explained in order to design sonochemical reactors. The impedance of piezo electric ceramics changes with resonance frequency. Moreover, since ultrasonic wave is reflected with the water surface or a vessel wall, water resonates on some conditions and the impedance of a transducer also changes. The optimal drive frequency is obtained by monitoring the imrjedance of a transducer.

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A new ultrasonic thermometry for monitoring temperature distributions of materials being heated or cooled is presented. The method consists of an ultrasonic pulse-echo measurement and an inverse analysis for determining a one-dimensional temperature distribution. The advantages of the method are that (1) no boundary condition at the heating surface of a material is needed, (2) it is possible to estimate both internal and surface temperature distributions of materials, (3) it provides non-invasive or non-contact measurements, and (4) the time response is faster than that of a conventional thermocouple and therefore it is appropriate to monitor transient variation of temperature. To demonstrate the practicability of the ultrasonic method, some experiments are carried out. At first, the internal temperature distributions of thick plates of 30 mm thickness (silicone rubber or steel plate) whose single sides are being heated are evaluated. The temperature distributions determined by the ultrasonic method agree with those measured using thermocouples installed in the plates. Next, a laser-ultrasound technique that provides non-contact ultrasonic measurements is employed to evaluate surface temperature distributions. It is demonstrated that the ultrasonically determined results almost agree with those measured using an infrared radiation camera. Thus, the ultrasonic method is believed to be effective for the in-situ or in-process monitoring of temperature distributions of materials being processed at high temperatures.

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Microbubble contrast agents were originally developed to enhance echogenicity in diagnostic sonography. However, their somewhat unique acoustic response and facility to transduct energy into spatially focussed regimes, together with the clinical demand for non-invasive adjuncts and options to conventional therapy, have seen interest in exploring the therapeutic potential of microbubbbles grow steadily within this past decade or more. For the purposes of the present paper, the author has sought to select several key aspects of acoustically driven microbubble interactions, (both with other bubbles, and with cells also) and to assess what we have learned, and perhaps more importantly, what we still require to understand better. This is presented in the context of both in vitro sonoporation experimentation, and also with more clinically related areas such as transdermal drug delivery En route, we will highlight some personal preferences with in-vitro experiments, namely the advantages to be gleaned by controlling the spatial placement of microbubbles within bespoke optical traps. The objective here is to improve our understanding of their statistical behaviour of interactions, and to validate computational models for eventual optimisation. Observations first centre on individual microbubbles of commercial [low-index] ultrasound contrast agents and their interactions with proximal surfaces. We then progress to the situation of multiple microbubbles in controlled geometries. Some nuances of high speed imaging cameras are highlighted. We also compare our own observations with a selection of corroborative highlights from the literature, and finally, make some suggestions as to where future research efforts might be most fruitfully directed.

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Ultrasound is often used in the preparation of size-controlled liposome, which is used as drug delivery carrier. The effects of sonicating liposome have a lot of questions to be resolved. In this work, we investigated the oxidation of unsaturated phospholipid by sonication, particularly focusing on the effects of irradiation time, frequency, and intensity of the ultrasound. The phospholipid we used is egg yolk phosphatidylcholine. Phospholipid solution was sonicated with a horn type homogenizer (20kHz) and a bath-type ultrasonic reactor (490kHz), both of which have a thermostatting system which kept the sample solutions 25℃. The sonication times are from 0 to 2 hours, and the effective power of the ultrasound, which is determined by a calorimetric method, are 9W, 21W and 33W for 490kHz experiments, and 21W for 20kHz sonication. We determined the amount of double bond and bisallyl hydrogen in phospholipid from the area of their characteristic peaks by NMR, and the amount of TBARs, which are the product of the reactions of aldehydes and lipid peroxides with 2-thiobarbituric acid, were determined by a TEA assay. As a result, it was revealed that the sonication brought about decreases in the amount of double bond and bisallyl hydrogen, and increase in that of TBARs. It indicates that the lipid was oxidized by sonication. From the change of the amount of these species, the sonication of higher intensity caused stronger lipid peroxidation, and lower frequency ultrasound has more powerful oxidation effect than higher frequency one. We measured the amount of OH radical generated by sonication with a KI method, and we found higher frequency sonication is more efficient to product OH radical. Therefore our experimental results suggest that the rate of OH radical production is not the only mechanism that affects the ultrasound-induced peroxidation of lipids.

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Precision cleanings of stainless steel plates covered with press working oil by using ozone microbubble(bubble size: Ca. 2-50 μm) combined with sonication(42KHz, 40W) were investigated in water. Oil removal efficiencies of the sample plates were investigated by using a microscope, FT-IR and a waterdrop contact angle measurering apparatus. From experimental results, effective removals of press working oil from the surfaces of the sample plates by the investigated cleaning mehod were shown to be achieved.

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When ultrasound is irradiated to liquid surface, small liquid droplets are generated from fountain jet. The purpose of this study is the estimation of the flow rate of droplet in ultrasonic atomization. The rectangular vessel was put on an electronic balance. An ultrasonic transducer at 2.4 MHz and 20 mm in diameter was installed at the center of the vessel bottom. In order to produce fountain jet without ultrasound, the liquid pump and nozzle was used. The mass change for ultrasound is larger than that for liquid pump. It is defined that the difference of mass changes between ultrasound and liquid pump is the flow rate of droplet. The flow rate of droplet in ultrasonic atomization increase with height of fountain jet and acoustic pressure.

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The ultrasonic degradation products of poly(ethylene oxide)-poly(propylene oxide) diblock copolymers were characterized by MALDI-TOF-MS and high resolution mass spectrometry. Several ions in the products could not be assigned by MALDI-TOF-MS because of its low mass resolution. However, using high resolution mass spectrometry it was determined whether the end-group of these ions is oxo or ethoxy structure. The mass spectra obtained with high mass resolution are useful information for detailed analyses of repeat unit and end-group of the ultrasonic degradation products.

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The correlation between sonoluminescence and ultrasonic degradation (UD) efficiency of polyethylene glycol (PEG) was studied using 100, 400, and 1000 kHz ultrasonic transducers. The intensity of luminol luminescence was obtained from visualization of cavitation and sonication of PEG was measured using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). The results showed that both the luminescence due to reactive radicals and the sonication of polymers were accelerated with increasing in applied voltage and the 400 kHz transducer was the highest efficient for the sonication of PEG. As a result, the luminescence was found to give an indication of optimization for polymer degradation.

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In recent years, ultrasonic atomizers have received much attention in light of their potential practical applications. It has been found that a large amount of mist and/or very small droplets are produced from a solution resulting in a foggy state in the area over a gas (air)-liquid interface at 2.4 MHz. Ultrasonic irradiation was performed from the bottom of the reactor using ultrasonic atomizer (Honda Electric, HM-303N, 2.4 MHz). Sonolysis of several kinds of reactants, such as potassium iodide, pure water, and malonic acid was perfomed using an ultrasonic atomizer at 2.4MHz. Reactions proceeded all the cases. In the case of pure water, however, abnormal rates of products were sometimes obtained under direct irradiation of ultrasound. These phenomena could not observe under indirect irradiations through Pyrex glass although lower yields were obtained. After examination, it might be considered that metal surface on the transducer played a catalyst for degradation of hydrogen peroxide. As another example reaction, sonolysis of malonic acid was carried out. Similar products were obtained compared with 200 kHz transducer. The yield of hydrogen peroxide, however, was lower because of direct irradiation.

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Megahertz ultrasound use harmless technique for diagnosis and therapeutic technique. However, megahertz ultrasound technique induces irreparable damage to body tissue. In our studies, we aimed to assess safety of megahertz ultrasound and further investigate the mechanism of megahertz ultrasound induced gene expression. Continuous-wave ultrasound in the range of frequency of 1.0 MHz to 5.7 MHz was delivered to human myeloid leukemia U937 cells. Ultrasound exposure was delivered with 10-seconds and a various intensity level, which was determined by calorimetry and verified with ultrasonic hydrophone. As a result, induced gene expression was different by ultrasound irradiance condition. The effect of ultrasound on the rate of cell proliferation was evaluated using a particle counter in all frequencies after irradiation 72 h. The effect of ultrasound cell membrane damage was observed in the frequency range from 1.0 MHz to 3.4 MHz. Cell membrane damage was tested using a flow cytometer. We also observed apoptotic cells at 5.7 MHz using a flow cytometer. These results were caused presumably with generation of free radical by ultrasound cavitation. We determined quantity of free radical by ultrasound exposure using an electron spin resonance in order to confirm relevance gene expression and free radical. We intend to report various biological effect of megahertz ultrasound on human myeloid leukemia U937 cells.

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Photoactivatable caged reagents are useful tools for researching the cell system. These caged reagents can be activated on request with UV light as a trigger. The main idea of this research is to activate these reagents by sonolysis instead of photolysis for the development of new drug derivery systems. As a caged reagent, we tested (l-(4,5-dimethoxy-2-nitrophenyl)-1, 2-diaminoethane-N, N,N',N'-tetraacetic acid) : DMNP-EDTA, which is known as a Ca^<2+> chelater. Destruction of caging moiety leads the loss of chelating ability in DMNP-EDTA. As a result of UV irradiation, DMNP-EDTA release chelated ion. Photolysis of caged reagent was done with 500 W high pressure mercury lamp SX-UI501HQ (USHIO, Japan). For the attempt of sonoactivation, 1 MHz continuous wave was employed. Intensity of ultrasound was evaluated with TORAY NH1184 hydrophone. Photon emission from aequarin combined with Ca^<2+> was assayed with AB-2200 Luminescencer PSN (ATTO, Japan). Just as UV irradiation, sonoirradiation induced the decrease of chelating ability of DMNP-EDTA to Ca^<2+>. These results show the possibility that ultrasound will control the dynamics of materials in living systems.

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Sonochemical reaction of acetic acid has been carried out. When pure acetic acid was irradiated with ultrasonic wave, carbon monoxide, carbon dioxide, hydrogen, methane, ethane, ethene were produced in gas phase. Moreover, succinic acid was produced in liquid phase. Pure water added into pure acetic acid as aim of increasing yields of radicals. In the case of addition of a small amount of water, the ratio of products was maintained although the yields of products increased. The rate of production was over 10 times, as large as in the pure acetic acid system. On the other hand, products ratio changed, when a large amount of water added into acetic acid. Thus, it is considered that efficiency of production of radicals was advanced up with addition of water into acetic acid. It was thought that succinic acid was formed through dimerization of acetate radicals. Thus, the elongation of carbon chain was observed.

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In this paper, we demonstrate the isomerization of unsaturated dicarboxylic acids during sonication. Almost all trials were carried out under irradiation of 200 kHz, 200W. Before sonication, pure argon gas (Ar) was passed through the reactant solution in order to expel the air. Concentrations and volumes of trial samples were 8-10 mM and 30-100 cm^3, respectively. Fumaric acid and maleic acid made isomerization under sonication each other. Because of obtaining similar amounts of CO and CO_2 each other, cleavage of reactants occurred and reactivities of both acids would almost the same. Higher stability trans type had higher yield, namely fumaric acid. So far, isomerization under ultrasonic irradiation was shown. However, additives were needed for isomerizaiton in those reports. In our system, on the other hand, isomerization occurred without additives. We also demonstrated dehydrogenation and forming double bond. In the case of sonolysis of succinic acid, unsaturated dicarboxylic acids were detected; those are fumaric acid and maleic acid. They are isomer each other and the carbon number of them are the same as succinic acid, namely 4. Succinic acid could be produced from acetic acid under sonication as reported Poster presentation (P-9) in this conference. Thus, continuous reactions under ultrasonic irradiation; those are carbon chain elongation from acetic acid, dehydrogenation from succinic acid and isomerization of their products might occur.

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Microbubble with a diameter less than 50 urn in a liquid has very useful characteristics. However, it is difficult to control the dynamic behavior of microbubbles in a liquid. In our previous study, when the ultrasound is irradiated into the microbubble suspension that looks milky white, the suspension rapidly becomes clear. In this study, the mechanism of this behavior was investigated by visualization. Especially, the effects of surfactant addition, pH of solution and ultrasonic frequency on dynamic behavior of microbubbles in an ultrasonic field were investigated. Before ultrasonic irradiation, microbubbles stably dispersed in the liquid by electrical repulsion. After ultrasonic irradiation, microbubbles approached and were agglomerated by second Bjerknes force, and rise velocity of bubble was increased. After ultrasonic irradiation was stopped, the bubble dispersed again. This behavior of microbubble was able to be reversibly controlled by ultrasonic power. And, the size and shape of agglomerated bubbles were influenced by ultrasonic frequency. On the other hand, electrical repulsive force of microbubble decreased with lowering pH of solution, and microbubbles were coalesced at pH = 3.5. Then, the relationship between second Bjerknes force and potential of surface of the microbubble influence the agglomeration behavior.

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Palladium nanoparticles were successfully immobilized on the surface of magnetic γ-Fe_2O_3 nanoparticles by the sonochemical reduction method. HAADF-STEM observation showed that the size of the immobilized palladium nanoparticles were several nanometers. The Pd/γ-Fe_2O_3 composite nanocatalysts exhibited high catalytic activity for nitrobenzene reduction, and formed aniline with high selectivity and high turn over frequencies. In addition, after several reuse cycles, the catalysts maintained the activity.

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In recent years, many countries around the world have the energy and environmental problems such as the depletion of fossil fuels and the increase of green house gas including CO_2. To settle the problems, the use of biodiesel fuel that is one of biofuels should be useful, since the biodiesel fuel has features of carbon neutral and renewable energy, etc. Generally, fatty acid methyl ester (FAME) that is constituents of the biodiesel fuel is synthesized by using alkali hydroxide that is a homogeneous catalyst. However, it costs a lot of money to removal of the catalyst and to wash the product in this method. The use of a heterogeneous catalyst such as CaO for synthesis of FAME can solve the problems because it is easier to separate it from the solution after reaction. However, the synthesis rate of FAME using a heterogeneous catalyst decreases compared with that using a homogeneous catalyst. In this study, an attempt was made to synthesize the biodiesel fuel using a CaO catalyst under the ultrasonic irradiation. We compared the formation behavior of the biodiesel fuel under sonication with that under the mechanical stirring. In addition, the effect of the ultrasonic power on the reaction rate was investigated.

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In this study, the effect of the initial pH of solution on sonochemical degradation of EDTA, CuEDTA or ZnEDTA in an aqueous solution was observed. Also, the synergy effect of sonochemical degradation of metal complex and sulfurizing agent addition on the degradation rate was investigated. The frequency of ultrasound was 503kHz. During ultrasonic irradiation, the temperature of sample solution was kept at 298±2 K. The initial concentrations of EDTA, CuEDTA and ZnEDTA were 5.0x10^<-4>M. The pH adjustment of solutions was made by adding the buffer solution, hydrochloric acid solution, or sodium hydroxide solution. Sonochemical degradation rate constant of EDTA, CuEDTA or ZnEDTA under acidic condition was greater than that under base condition in all sample solution experiments. It is expect ed that sample compounds have higher hydrophobic property under acidic condition. As a result, they are likely to be concentrated at the surface layer of hot spot, which may enhance the degradation rates. Because of structural difference between CuEDTA and ZnEDTA, Cu^<2+> in CuEDTA reacted easily with Na_2S to form precipitates, CuS, whereas Zn^<2+> in ZnEDTA was not sulfurized at all. When ZnEDTA was sonicated with the addition of Na_2S, the degradation rate constant in the condition of stoichiometric Na_2S was greater than that in the condition of only sonication.

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Mechanoluminescent (ML) material is a novel functional material and it can emit intensive light emission repeatedly with weak stress application excising in our ordinary life. The ML materials are powder of ceramics, and as the characters one by one particle itself is stress sensor and emitting material. In addition, recently, we succeeded to synthesize the ML nanoparticle with the size of 10 nm, and it is enough small to inject and use in bio-body. From these viewpoints, we believe that our ML nano- or micro- particle can be used as an ubiquitous light source even in the dark bio-tissue and cell. For the purpose, we have investigated mechanoluminescence induced by ultrasonic wave, non-destructive and non-inventive stimulation for bio-tissue, and we successfully detect the mechanoluminescence.

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Sonochemical degradation of aromatic compounds was performed by a 200kHz ultrasound sonicator in water. A Langmuir type mechanism was adapted to discuss the reaction kinetics, although a homogeneous solution was used for the degradation experiments. The kinetics model used here is based on the local reaction zone at the interface region of cavitation bubbles, where an extremely high concentration of OH radicals exists. To confirm the proposed kinetics model, the effects of initial concentration of aromatic compounds on the degradation rates were investigated. It was suggested that the degradation of aromatic compounds mainly proceeds inside the local reaction zone of the cavitation bubbles and the hydrophobisity of compounds affect the accumulation amount at the interface region of cavitation bubbles.

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Oil sands are the mixture of bitumen (heavy oil) and siliceous materials (sand, sandstone). The bitumen content of oil sands is 10-15wt.%. Main industrial processes to extract bitumen from oil sands need treatment with hot water and steam. The addition of chemical agents (alkaline reagent, surfactants) has been investigated to improve the yield of bitumen. The objective of the present work is to study the extraction of bitumen from oil sands using ultrasound irradiation combined with hot water treatment, and remove the use of chemical agent, thereby reducing the environmental burden. A sample of oil sands from Alberta, in Canada was used in this experiment. The suspension of oil sand was prepared by mixing oil sand with distilled water in a flask and sonicating it at 28 kHz. Then the suspention was treated by hot water while being stirred. After the hot water treatment, the extracted bitumen floating on the water surface was collected and weighed after drying. Oil sand and the recovered bitumen were analyzed with a thermo-gravimetric analyzer (TGA) under Ar flow. The result of TGA indicated that the bitumen content in the oil sand was 12.3 wt.%. We applied ultrasound irradiation in combination with hot water treatment, and successfully extracted 60 % of the bitumen content. After this extraction process, fine particles of sands in the suspension were precipitated by sonication at 200 kHz without addition of any precipitant. Thus, our bitumen extraction process does not require chemical agents and reduces environmental burden.

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The present study aimed for the sterilization of soil and aquifer polluted with microorganisms, and investigated the influence of ultrasound treatment on soil particles. Microorganisms used for this study belong to the genus of Bacillus that lives in underground aquifers. Green tuff (Akita, Japan) was used as soil particles. A "microbial solution" containing 2.0×10^<-6> CFU/ml microorganisms and a "microbial suspension" containing 2.0×10^<-6> CFU/ml microorganisms and 1.0×10^<-3> wt% green tuff were used as sample solutions. When the comparison is made for microbial solutions between 28 kHz and 200 kHz treatments, bactericidal effect of 28kHz irradiation was higher than 200kHz irradiation. When the green tuff particles were included in the solution, 28 kHz irradiation had the same sterilization effect as for the solution without particles, but the effect of 200 kHz irradiation was remarkably reduced. The reason of this deteriorated sterilization effect at 200 kHz is not clear, but likely that radicals and hydrogen peroxide reacted with the particles, thus reducing the rate of reaction for the sterilization. 28kHz irradiation had a beneficial effect on sterilization process of microorganisms belong to the genus of Bacillus.

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Sonoluminescence pulse width of sodium atom and continuum emissions were observed from NaCl solution in ethylene glycol and Na2SO4 solution in sulfuric acid. The sodium atom emission pulse in ethylene glycol showed multi-peak shape, which disagrees with the result by Arakeri et al. who reported Gaussian shape pulse with the width ranging from 10 to 165 ns The multi-peak pulse may be superposition of single pulses. The result of high-speed photography suggests that the cause of multi-peak pulse is due to many daughter bubbles fragmented from large bubble. In the case of sulfuric acid solutions, pulse shape of sodium atom emission is similar to that in ethylene glycol, whereas the pulse width of continuum emission is about 15 ns.

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Heat shock protein (HSP) induced in cells has a cytoprotective effect. Recently, the application of heat shock and medical agents to cells has been studied as one of the methods to induce HSP. However, these methods have drawbacks such as heavy burden for human body and difficulty in controlling the prescription condition. The present study focused on the chemical effects (the generation of active oxygen species) of ultrasound exposure on the induction of HSP. Our objective was to induce HSP in HuH7 cells by ultrasound exposure in vitro. The ultrasound exposure condition was at the frequency of 1MHz and the power output of 0.5〜2.3 W. To confirm the basic performance of this device, we exposed ion-exchange water by ultrasound and measured the concentration of the generated H_2O_2 by KI method. H_2O_2 was generated at power outputs over 1.4 W. HuH7 cells were exposed by ultrasound for 1 to 20 min at the intensity of 1.4 W or 2.3 W. When the device intensity was 1.4 W, HO-1 and HSP72 were not induced. However, when the exposure intensity was increased to 2.3 W, HO-1 and HSP 72 were successfully induced after 10 min and 20min of irradiation, respectively. Thus, we demonstrated that ultrasound exposure could induce HO-1 and HSP 72 in HuH7 cells..

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We present a method to treat suspension contaminated with trichloroethylene (TCE). We aimed to remove TCE and precipitate the fine particles in the suspension using ultrasound irradiation. The solution was prepared from ion-change water and TCE. The suspension was prepared from the solution and green tuff. TCE solution (500ppm) was completely decomposed by 2h sonication in argon atmosphere. And the complete decomposition of TCE in suspension (500ppm) was also confirmed at the same condition. The decomposition rate of TCE in solution and suspension were almost same. Isoelectric zone of green tuff suspension was 1.4-3.8 in pH. The degradation of TCE acidified the solution and brought the pH level of the suspension to the isoelectric zone. Thus, it is feasible to remove TCE and precipitate fine particles in the suspension using ultrasound irradiation.

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We have suggested the volatile organic compound (VOC) removal processes using ultrasonic mist containing photocatalysis (UMP) and UV irradiation to generate OH radicals in our previous study. In this study, we want to develop the removal process of toluene gas using reactive mist produced by ultrasonic irradiation with hydrogen peroxide solutions and UV irradiation to generate OH radicals. It was shown that effective removal toluene gas was achievable by both of the UV irradiation and OH radicals when hydrogen peroxide presented in the ultrasonic mist. This process may be applied as a new air purification technique.

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The growth and collapse processes of cavitation bubbles under ultrasonication lead to generation of enormous pressures and temperatures, so that physical and chemical effects emerge at the local locations in the liquid in a reactor. The chemical reaction processes utilizing these effects are called sonochemical processes. On designing the sonochemical reactor, it is important to know how a variety of physical or chemical parameters influence acoustic power or cavitation intensity. The purpose of this study is to investigate the relation between the pressure or temperature and the efficiency of the chemical reaction induced by ultrasonication in a flow-type sonochemical reactor. The frequency-dependence of the transducer impedance was investigated under the different pressure and temperature conditions. The effects of the pressure and temperature on the sonochemical effect were evaluated by KI dosimetry.

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Polymer hydrogels, like carrageenan, have various functions which is used to many field of the medicine, food, the manufacturing product and construction, etc. Recently, we have investigated the swelling behavior and the crosslinked structure of the natural polymer gel, since, especially, the research example of the gel characteristic by the ultrasound was very little, the clarification of the ultrasound (US) effect could be proved do apply for various fields in the new future. In this research, the influence of ultrasound on the κ and i-carrageenan-hydrogels were studied in the view point of US effect. The carrageenan gel solution contained 3g κ or i-carrageenan in 97ml water was used. In the carrageenan gel solution, viscosity was measured when B type viscosity meter was used with 6 and 30 rpm rotation after exposure of 28kHz frequency with the US power of 200W. It was found that hydrogen bonds in the hydrogels were broken by irradiating the US.

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We examined sono-responsibility of volume phase trasition of cross-linked polyN-isopropylacrylamide (PNIPAM) , P(NIPAM-co-acrylic acid) (PNAM) and P(NIPAM-co-methacrylic acid) (PNMM) microgels, which were produced by surfactant-free emulsion polymerization. The volume phase transition behaviors of these microgels were investigated in the absence and presence of ultrasound (24, 48, 100kHz, 300W). The results shows that the volume phase transition of PNAM was shifted toward higher temperature region by ultrasound exposure, while that of PNMM and PNM was un-changed.

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In this work, an application of the ultrasonic method to internal temperature measurements of materials during casting has been studied. The principle of the method is based on the temperature dependence of the velocity of ultrasonic wave propagating through a material. An inverse analysis coupled with a finite difference calculation is used to determine a one-dimensional temperature distribution. An attempt to monitor both temperatures of a solidifying alloy and a die during casting process has been made. A low melting-point alloy is employed as the melt. Ultrasonic pulse-echo measurements are performed and the changes in the transit times of the reflected echoes through the die and the alloy are continuously acquired, and then the temperature distributions inside the die and the alloy have been estimated during the casting process.

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Kenaf is one of the most promising biomass for biofuel production due to its rapid growth. However, lignin covering cellulose fiber is obstacle against effective saccharification by enzyme. Therefore in the present study, we employed ultrasonic (US) for simple and effective pretreatment of biomass, which was needed for subsequent enzymatic saccharification. First, effect of US pretreatment on the saccharification ratio was investigated. Moreover, effect of TiO_2 addition into US pretreatment on the saccharification ratio was also investigated. The saccharification ratio enhanced from 30% to 42%by US treatment for 360 min, although no significant enhancement was observed by US treatment for 60 min. On the other hand, in the presence of TiO_2 (non woven fabrics type), there was significant enhancement of the saccharification ratio by US treatment even for 60 min. This might be attributed to that the presence of TiO_2 enhanced OH radical generation under US irradiation. These results suggested TiO_2/US method could be used as effective biomass pretreatment.

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Chemotherapy is often complicated by toxic side-effect of the antitumor drugs. To solve this problem, it is necessary that antitumor drugs are effectively delivered to the tumor site specifically. The drug delivery system (DDS) using liposome as drug carriers has been proposed. However traditional DDS can not achieve full therapeutic effect. Recently, next-generation DDS that combines treatment of utilized physical energy and DDS of antitumor drugs is proposed. Therefore we propose development of pinpoint antitumor drug delivery using ultrasound and liposome as the next-generation DDS. We used liposome modified with thermosensitive polymer as ultrasound stimulus-responsive carrier. This polymer develops phase transition at a lower critical temperature (LCST) and interacts with liposomal membrane. In this study, we made the calcein-loaded thermosensitive liposome (TSP-Lip), and irradiated it with ultrasound. After irradiation, the release of calcein from liposome was measured by the fluorescence intensity with a spectrofluorometer. The results indicated that the release of calcein from TSP-Lip was increased with an increase of ultrasound intensity compared to the non-modified liposome.

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We observed ultrasonic cleaning process of molecules absorbed on metal surface by surface enhanced Raman scattering. The metal is silver, and adsorbed molecules are rhodamine 6G (R6G). Metal surface is treated by oxidation-reduction cycle, and saturated with R6G in 10^<-9>M solution. The ultrasonic bath is shown in Fig. 1, which is consisted of 477 Hz transducer, glass inner cylinder, and acrylic outer cylinder. The sample is excited by argon ion laser. The scattering light is focused onto a spectrograph and detected by CCD. Raman spectrum is shown in Fig.2. Broad background emission is fluorescence, and sharp peaks are SERS. Fluorescence decreased quickly, whereas SERS decreased slowly. SERS intensity of Raman spectrum around 1700 cm^<-1> is shown in Fig.3. Although the decrease in SERS intensity occurs gradually without sonication, the decay rate greatly enhanced by ultrasound, which indicates that the R6G molecules adsorbed on the silver plate are desorbed on decomposed by the ultrasound. Comparing the results with different ultrasonic powers, SERS is lost within 5 minutes under 26 W ultrasound, while small amount of SERS remains after the 30minutes irradiation of 5 W ultrasound. It means that the absorbed R6G is lost more efficiently with stronger ultrasound.

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A two-phase (H_2O/CHCl_3) procedure for the mono-bromination of phenol with KBr and H_2O_2 catalyzed by molybdenum was carried out under sonication. This reaction does not take place under our silent conditions. The irradiation of 20 kHz ultrasound gave 93% yield of o-and p-bromophenols in 4 h. With neither catalyst nor H_2O_2 it gave only 23% yields. Increasing the ratio of H_2O/CHCl_3 did not change the result. This suggests the possibility to make the use of organic solvent decrease. Although 480 kHz compared to 20 kHz gave the lower yield, 68%, the ratio of o-/p-bromophenol did not changed. This suggests the reaction mechanism is the same and the role of ultrasound may be mainly an efficient mixing.

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