Effect Of Ultrasonic Irradiation Research Articles

The sonochemistry of zinc powder

The effects of ultrasonic irradiation on the chemical reactivity, particle and surface morphology, and surface atomic composition of Zn powder are studied.

Effects of Ultrasonic Irradiation at Various pH on Several Properties of Gelatin

Effects of Ultrasonic Irradiation at Various pH on Several Properties of Gelatin

Ultrasonic irradiation of copper powder

Ultrasonic irradiation enhances the reactivity of metal surfaces. Because of this, the sonochemical activation of various metals has become a routine synthetic technique. The mechanisms of heterogeneous sonochemistry, however, remain largely unexplored. In comparison, a detailed understanding of the mechanism of homogeneous sonochemistry has recently been developed. To more fully understand the origins of heterogeneous sonochemistry, we have examined the effects of ultrasonic irradiation on copper in terms of surface morphology, atomic composition, and reactivity. We report here that ultrasonic irradiation of Cu powder leads to substantial changes in all three areas. We believe that these effects are due to interparticle collisions driven by the shock waves created by the ultrasonic field: the origin of the enhanced chemical reactivity comes from the removal of the surface oxide passivating layer and surface damage that these collisions induce.

Effect of Ultrasonic Irradiation on the Recovery of Uranium from Seawater with Adsorbents

Ultrasonic irradiation is reported to promote chelate formation between metal ions and polymeric ligands in solution (1). It is expected that the recovery of uranium from seawater with adsorbents i...

Effects of ultrasonic irradiation in flow-injection systems

The effects of ultrasonic irradiation on transport and reactions in several flow-injection manifolds are described. The influences of ultrasound on the physical dispersion of the injected plug is considered. Its effects on systems involving homogeneous (catalytic and non-catalytic) and heterogeneous (liquid/liquid extraction, precipitation) reactions are critically evaluated. In general, greater sensitivity is obtained, especially for heterogeneous systems, slow reactions and low analyte concentrations. Finally, practical considerations and potential uses of the combination of ultrasonic irradiation with flow-injection analysis are discussed.

Effect of ultrasonic irradiation on the dissociation of antigen-antibody complexes. Application to homogeneous enzyme immunoassay.

Effect of ultrasonic irradiation on the dissociation of antigen-antibody complexes. Application to homogeneous enzyme immunoassay.

Effect of ultrasonic irradiation on ion binding by synthetic polyelectrolytes using terbium(3+) as a fluorescence probe

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTEffect of ultrasonic irradiation on ion binding by synthetic polyelectrolytes using terbium(3+) as a fluorescence probeN. Yoshino, S. Paoletti, J. Kido, and Y. OkamotoCite this: Macromolecules 1985, 18, 7, 1513–1515Publication Date (Print):July 1, 1985Publication History Published online1 May 2002Published inissue 1 July 1985https://doi.org/10.1021/ma00149a028RIGHTS & PERMISSIONSArticle Views104Altmetric-Citations29LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (350 KB) Get e-Alerts Get e-Alerts

じゃがいもでんぷんに及ぼす超音波照射の影響

超音波照射(400kHz,5W/cm2)によって引き起される馬鈴薯澱粉粒の破壊について研究した.顕微鏡による観察では澱粉粒の大きさに従った損傷形態が認められ,小粒には多くの深い小穴を生じるが,大粒にはこれを生じがたい.このことは,照射による澱粉粒の可溶化の値の相違から証明しうる.しかし,被照射の大・小粒のゲル炉過による分析では粒子の大きさにかかわらず澱粉分子の分解は同じように示された.このことから,超音波照射による大・小粒の損傷形態の相違は澱粉粒の構造間の違いを示唆すると考えられる. この研究の費用の一部は文部省科学研究費補助金(課題番号58360011)によって行った.ここに感謝の意を表します.

Critical comments on the interpretation of heat capacities of activation and on the experimental evidence for other recent mechanistic proposals for solvolyses of t-butyl halides in water and in binary aqueous mixtures

Kinetic data for solvolyses of t-butyl bromide in homogeneous solutions in water and in aqueous binary mixtures with acetone, methanol and ethanol at 25 °C are reported, illustrating the development of simple conductometric techniques for studying relatively fast solvolytic reactions of sparingly soluble solutes. Solvolyses of t-butyl chloride in water and in aqueous ethanol are re-examined. Experimental errors due to (a) equilibration of solute between liquid and vapour phases and (b) formation of hydrophobic aggregates which can be disrupted by ultrasonic irradiation are discussed. Four recent mechanistic proposals are critically reassessed. It is shown that: (1) the induction period observed at low solute concentrations for solvolyses of t-butyl chloride in water is due to the buffering action of absorbed carbon dioxide; (2) recent kinetic data on the effects of ultrasonic irradiation are unreliable; (3) deviations from first-order kinetics for solvolyses of t-butyl chloride in 40% ethanol + water mixtures are due to equilibration of solute between liquid and vapour phases. It is also argued that (4) the most recent interpretations of heat capacities of activation, suggesting partially reversible formation of an intermediate in hydrolysis of t-butyl chloride, do not take adequate account of alternative interpretations.

The effect of ultrasound on the solvolysis of 2-chloro-2-methylpropane in aqueous alcoholic media

The effect of ultrasonic irradiation (45KHz at 25°C) on the solvolysis of t -butyl chloride in aqueous ethanol, i -propanol and t -butanol is (1) to increase the rate constants in the more alcoholic media and (2) to reduce the m values of these reactions.

The effect of ultrasonic irradiation on the template activity of calf thymus DNA.

An aqueous solution of calf thymus DNA was irradiated with 19.5 kHz ultrasound, and the template activity of the DNA for RNA synthesis in vitro was investigated. The template activity of the DNA was assayed by the incorporation of 14C-AMP into the synthesized RNA. The template activity of DNA decreased rapidly by sonication for the initial short period, and then further decreased exponentially with the increment of sonication period. The neutral sucrose gradient analysis of the sonicated DNA showed that the rapid reduction of the molecular weight was induced for the initial short period of sonication, and that the further sonication had little effect on it. This result indicated that the initial rapid decrease of the template activity was mainly due to the reduction of the molecular weight, i, e., due to the double strand breaks. The production of single strand breaks in the sonicated DNA was also investigated by alkaline sucrose gradient analysis. It was found that the number of single strand breaks increased with the increment of sonication period. The single strand breaks produced by sonication seem to participate in the above mentioned exponential decrease of the template activity.

Suspension polymerization of styrene under ultrasonic irradiation.

The suspension polymerization of styrene under ultrasonic irradiation was carried out in batch and continuous stirred tank reactors. In both reactors, it was confirmed that ultrasonic irradiation was an effective method to prevent the agglomeration between droplets and sticking of droplets to the reactor wall. In the batch reactor, the effects of ultrasonic irradiation on the conversion of monomer and the average molecular weight of polymer were negligibly small. In the continuous reactor, the experimental results of the conversion and the average molecular weight showed that the interaction between droplets in the reactor was not small. The calculated results in the two extreme cases of complete micro-mixing and complete segregation showed that the conversion and the average molecular weight were noticeably affected by the interaction between droplets in the region, where the gel effect became remarkable.

Blood chemical and hematological effects of ultrasonic irradiation of mice

Batteries of 23 chemical and 7 hematological blood constituents and factors were determined to indicate possible damage to female albino Swiss-Webster mice of ultrasonic irradiation in vivo (2MHz continuous wave, 1 W/cm 2, 34°C). Untreated, sham-treated, and treated mice were used. Effects observed 2 and 24 hr after ultrasonic exposure for 200 sec, and those seen 24 hr after 50 and 200 sec exposure, were compared. These comparisons showed: (1) Sham treatment alone induced significant changes in levels of certain of the blood constituents. (2) Some significant differences between the treatment and the shamtreatment groups were separately apparent 2 and 24 hr after irradiation, indicating recovery at 24 hr from certain of the 2 hr effects. Other changes, probably more significant, were still present 24 hr after treatment. (3) Changes found with 200, but not 50, sec of irradiation indicate that there is a threshold between these times for the appearance of the changes evoked under the conditions used.

The effect of ultrasonic irradiation on the structural integrity of the inner ear labyrinth.

The histological appearance of the inner ear labyrinth was examined following ultrasonic irradiation of the vestibule and the cochlea in cats and guinea pigs. Directing ultrasound through the round window towards the ampulla of the superior semicircular canal produced severe balance dysfunction together with histological damage throughout the vestibular labyrinth. Cochlear damage was restricted to a small region of the basilar membrane proximal to the round window. When ultrasonic energy was directed into the cochlea cellular disruption extended over an area of at least two cochlear turns and included changes in the stria vascularis as well as to hair cells. The outer hair cells were found to be more sensitive than the inner hair cells to the damaging effects of ultrasound.

Effect of ultrasonic irradiation on the solvolysis of 2-chloro-2-methylpropane in aqueous ethanol mixtures

Ultrasonic irradiation has been found to increase the rate constants for the solvolysis of 2-chloro-2-methylpropane in aqueous ethanol by a factor of 1·5 at 10% v/v ethanol and 1·9 at 40% v/v ethanol.

Effect of ultrasonic irradiation on Mammalian cells and chromosomes in vitro

Human peripheral blood and HeLa cells were irradiated in vitro at the ultrasonic frequency of 65 kHz. The whole blood and HeLa cell suspensions were exposed to continuous and pulsed ultrasonic power levels of 0.12, 0.16, 0.72, 1.12 and 2.24 W for a period of one minute. The irradiation was carried out with the suspensions coupled directly to a cylindrical transducer while heating of the cell suspensions in excess of 41 degrees C was avoided. Irradiated and unirradiated peripheral blood lymphocyte chromosome cultures were prepared and scored for selected numerical and morphological aberrations. There was no significant difference in the frequency of chromosomal aberrations between irradiated and unirradiated cells. The fraction of cells S surviving after an exposure to an ultrasound dose of D can be represented by S=exp(-D/D0). Further, D0 is shown to depend on the time after exposure at which survival is assayed.

The Effects of Ultrasonic Irradiation on Electroless Nickel Plating

SummaryThe effects of ultrasonic irradiation on electroless nickel plating were studied for both basic and practical purposes. The results reported here indicate that the application of ultrasound during the plating process can be beneficial. The rate of deposition is ncreased by ultrasound. The hardness of the resultant deposits was 635 VHN50 compared to 535 VHN50 for normal deposits. Significant changes in the microstructure of the Ni-P deposits were also observed. Deposits formed with ultrasound had a lower phosphorus content. The concentration of catalytic inhibitors, such as thiourea, was found to be critical in the presence of ultrasonic irradiation. The formulation of the experimental plating baths, exemplified by the metal-chelate stability constant, becomes an important factor when ultrasound is applied to an electroless nickel plating system.

Histological effect of ultrasonic irradiation in Menière's disease.

The lateral semicircular canal and the crista ampullaris from five patients previously treated with ultrasound for Menière's disease showed the following histological and ultrastructural changes: 1. The lateral semicircular canal was completely obliterated by dense connective and osteoid tissue. 2. In the subepithelial tissue in Crista ampullaris no signs of degeneration was found. The nerve fibers were normal. 3. Also the sensory cells with nerve-endings and supporting cells appeared normal. 4. In the transitional epithelium there was vacuolization and extensive swelling with protrusion of the cells into the endolymphatic space. 5. The secretory cells showed pronounced cellular vacuolization and increased intercellular space. It is concluded that the massive destruction of the normal anatomy in the lateral semicircular canal may be the morphological basis of a functional endolymphatic fistula for drainage of the endolymphatic hydrops.

Spreading depression elicited by thermal effects of ultrasonic irradiation of cerebral cortex in rats.

Cortical spreading depression (CSD) was elicited by focused ultrasonic irradiation (800 kHz) of exposed cerebral cortex in anesthetized rats. With the acoustic output of 0.64 W at the probe-tissue contact (3 mm in diameter), CSD was elicited after 28-sec irradiation in normothermic rats. Reduction of cortical temperature to 31 degrees C increased the threshold irradiation time to 82 sec on the average. Ten- to thirty-sec heating of cerebral cortex with a thermode elicited CSD when surface temperature exceeded 47 degrees C. Histological examination of the cortical areas exposed to threshold irradiation revealed a central coagulation lesion surrounded by edema. It is concluded that the ultrasonic irradiation elicits CSD by dissipated heat. Differences in threshold duration of irradiation in hypothermic and normothermic rats were used to compute the threshold temperature which had to be exceeded in the critical volume of cortex in order to start CSD.

Effect of ultrasonic irradiation on cells synchronous culture

Effect of ultrasonic irradiation on cells synchronous culture