• Title/Summary/Keyword: Ultrasound irradiation

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Synthesis and Antimicrobial Screening of Some Fluorinated Azoles Containing (2-(6-Methyl-2-P-tolyl-lH-imidazo[1,2-a]pyridin-3-yl) Nucleus ((2-(6-Methyl-2-P-tolyl-lH-imidazo[1,2-a]pyridin-3-yl)핵종을 가지고 있는 불소화된 아조화합물의 합성과 항균활성의 스크리닝)

  • Shelke, Sharad;Salunkhe, Nilesh;Sangale, Sandeep;Bhalerao, Swapnil;Naik, Nilesh;Mhaske, Ganesh;Jadhav, Ranjana;Karale, Bhausaheb
    • Journal of the Korean Chemical Society
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    • v.54 no.1
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    • pp.59-64
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    • 2010
  • The synthesis of a series of fluorinated thiadiazoles 3, triazoles 4 and oxadiazoles 5 are synthesized from thiosemicarbazides 2 containing (2-(6-methyl-2-p-tolyl-lH-imidazo[1,2-a]pyridin-3-yl nucleus. These reactions were carried out by conventional method as well as ultra sound irradiation method. All products have been characterized by IR, 1H NMR, MS study and screened for their antimicrobial activity.

An Experimental Study on Bacterial Adhesion onto Activated Carbon and Ceramic (활성탄 및 세라믹 재질에의 세균 부착성에 대한 연구)

  • Kwon Sung-Hyun;Cho Dae-Chul;Rhee In-Hyoung
    • Journal of Environmental Science International
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    • v.14 no.12
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    • pp.1163-1170
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    • 2005
  • The microbial adsorption characteristics of two different media for biological treatment were studied using attached diverse microbes onto activated carbon and ceramic. The results in the experiments of the characteristics of physical adhesion on two different media with addition of high and low concentrated substrate in the culture were observed that the efficient of adhesion onto F-400 activated carbon was higher over that of ceramic due to the surface area of media. The irradiation treatment by ultrasonication with 400 W power and 3 min retention time on the media without addition substrate conditions and subsequent mixing throughly the culture showed the highest efficiency of cell detachment on the media. Three different microbes, P. ovalis, A calcoaceticus, and B. subtillis were used for the study of the characteristics of microbial adhesion on the media. p ovalis showed the highest adhesion capability while B. subtillis showed the lowest capability adhesion onto media either addition of substrate in the culture. The mixed bacterial culture showed $10\%$ lower removal efficiency of DOC in the low concentrated substrate culture compared to the single pure culture. Whileas, it did not show significant difference between two cultures at high concentrated substrate. It was also observed same population density of microorganism by counting of microbes adhered to microbial media with an ultrasound treatment.

Effect of Hydrogen Peroxide on the Acid Hydrolysis of Inulin (Inulin의 산 가수분해 반응에 과산화수소가 미치는 영향)

  • 윤석준;김성배최주홍박영철
    • KSBB Journal
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    • v.10 no.3
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    • pp.298-303
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    • 1995
  • Hydrogen peroxide has a characteristic of being dissociated rapidly into atomic oxygen and water when it is contacted with organic materials, resulting in a decrease in molecular weight of a polymer like carbohydrate. This effect on inulin hydrolysis under ultrasound irradiation was investigated. Maximum effect of hydrogen peroxide appeared at the H2O2 concentration of 2.3%(w/v) under the range of $50∼60^{\circ}C$ and 0.1∼0.3%(w/w) HCl. Compared to control reactions, the promotion effect reached 9∼43%. The activation energy, 26kca1/mo1, of inulin hydrolysis with H2O2 addition was similar to that without H2O2 addition, 25kca1/mo1. This implies that the rate enhancement of inulin hydrolysis with H2O2 addition is due to the increase of frequency factor.

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The Effects of Sonic Waves on the Reduction of Aromatic Nitro Groups Using Iron, Hydrazine Hydrate and Activated Carbon (유기 초음파화학. 초음파가 히드라진, 철, 활성탄을 이용한 방향족 니트로기의 환원반응에 미치는 영향)

  • Dae Hyun Shin;Byung Hee Han;Sung Yun Cho
    • Journal of the Korean Chemical Society
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    • v.30 no.1
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    • pp.105-108
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    • 1986
  • Ultrasound(50KHz) accelerated the reduction reaction of aromatic nitro group to aromatic amino group in high yield with mild condition using iron, hydrazine hydrate and activated carbon under room temperature and atmospheric pressure. The activated carbon has been used as a mixing material to highly active metals. However, aromatic nitro group does not reduce at all only with iron-hydrazine witliout adding activated carbon even under ultrasonic irradiation. We also discovered that the conversion yield from nitro group to amino group is directly proportional to the amount of activated carbon.

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Effect of reducing sodium chloride based on the sensory properties of meat products and the improvement strategies employed: a review

  • Kim, Tae-Kyung;Yong, Hae In;Jung, Samooel;Kim, Hyun-Wook;Choi, Yun-Sang
    • Journal of Animal Science and Technology
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    • v.63 no.4
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    • pp.725-739
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    • 2021
  • Many consumers are concerned about the high levels of salt intake owing to the accompanied risk of chronic diseases. Due to this dietary concern, the food industry has recommended the reduction of salt content in many products. However, the addition of salt to meat products improves their quality and sensory properties, including saltiness, color, juiciness, and texture. Because quality deteriorations could induce decreased sensory scores owing to salt reductions, the challenges involved in improving the quality of reduced-salt meat products have been addressed. During the development of low-salt meat products, it is important to reduce sodium content and address the problems that arise with this reduction. Modified salt, organic acids, amino acids, nucleotides, hydrocolloids, high-pressure, ultrasound, electric pulsed field, and irradiation have been suggested as strategies to replace or reduce sodium content, and sensory scores could be improved by these strategies. Therefore, when developing a low-salt meat product, several perspectives must be considered and the latest technologies that could resolve this problem should be adopted.

A Study on the Synergistic Effects of Hybrid System Simultaneously Irradiating the UV and US (자외선과 초음파를 동시에 조사하는 연계 공정의 시너지 효과에 관한 연구)

  • Lee, Hanuk;Han, Jonghun;Yoon, Yeomin;Lee, Jongyeol;Park, Jaewoo;Her, Namguk
    • Journal of the Korean GEO-environmental Society
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    • v.15 no.7
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    • pp.5-11
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    • 2014
  • Both ultraviolet (UV) and ultrasound (US) systems are used in degrading of organic contaminants and they can thus be applicable simultaneously as an UV/US hybrid system in attempts further to increase the degradation efficiency. The pseudo-first order degradation rate constants with the UV, US and UV/US hybrid irradiation were 2.60, 10.34, and $14.81{\times}10^{-3}min^{-1}$, respectively. It was observed that the synergistic effect of UV/US hybrid system for degrading the bis (2-ethylhexyl) phthalate (DEHP). The highest rate of DEHP degradation was found during UV/US hybrid irradiation and the synergistic effect factor (SEF) was calculated to be 1.15 based on the pseudo-first order degradation rate constants. Results indicate that synergistic effect of UV/US hybrid system is closely correlated to the enhancement of sonochemical reactivity with the UV-US interaction of increasing the formation rate of OHby providing additional $H_2O_2$ production through the pyrolysis of water molecules during UV/US hybrid irradiation.

Microbial Hazards and Microbe Reduction Technologies for Mushrooms (버섯의 미생물 위해성 및 저감화 처리기술 개발 현황)

  • Hyunji Song;Areum Han;Boyang Meng;A-Ra Jang;Ji-Yeon Kim;Sun-Young Lee
    • Journal of Food Hygiene and Safety
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    • v.38 no.5
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    • pp.287-296
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    • 2023
  • Mushroom consumption is gradually growing annually worldwide for many centuries. Oyster mushrooms (Pleurotus ostreatus), button mushrooms (Agaricus bisporus), and enokitake (Flammulina filiformis) are mainly consumed in Korea. However, mushrooms can be contaminated with pathogenic microorganisms, such as Listeria monocytogenes, because antibacterial treatment during mushroom cultivation and processing is insufficient. Therefore, many cases of mushroom contamination-related foodborne illnesses and food recalls have been reported. Three representative treatments are used to prevent microbial contamination in mushrooms: chemical, physical, and combination treatments. Among the chemical treatments, chlorine compounds, peroxyacetic acid, and quaternary ammonium compounds are commercially used and ozone and electrolyzed water has recently been used. Additionally, physical treatments, including ultrasound, irradiation, and cold plasma, are being developed. Combination techniques include ultraviolet/chlorine compounds, ozone/organic acid, and ultrasound/organic acid. This review describes the domestically consumed mushroom types and their characteristics, and investigates the mushroom contamination levels. Additionally, effective antibacterial technologies for reducing microbial contamination in mushrooms are also discussed.

Comparison of the $SO_2$ Removal Efficiency by Mixing Enhancement Shape (혼합 촉진 장치의 형상에 따른 탈황효율 비교)

  • Chung, Jin-Do;Kim, Jang-Woo;Bae, Young-Peel
    • Journal of Korean Society of Environmental Engineers
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    • v.32 no.1
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    • pp.17-22
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    • 2010
  • The aim of this study is to research applicable possibility of DSI (Dry Sorbent Injection) technique in $SO_2$ removal process using lab-scale facility based on 500MW in capacity coal-fired thermal power plant operated by South Korea N. Power Co., Ltd. To increase the $SO_2$ removal efficiency, it is considered the mixing enhancement as different shapes called lobed-plate and stepplate tested ultimately for optimum shape. Also it tested to analysis $SO_2$ removal efficiency by numbers of injection holes. At experimental it showed the $SO_2$ removal efficiency is higher using mixing enhancement than not installed mixing enhancement and case on the step-plate was shown the most $SO_2$ removal efficiency. Also, $SO_2$ removal efficiency was higher recording which will increase the injection holes case on not installed mixing enhancement. But, the $SO_2$ removal efficiency was higher 4 injection holes case on installed mixing enhancement.

Hemicellulose Recovery from Lignocellulosic Material Hydrolyzed by Water (물로 가수분해된 섬유성 기질로부터 hemicellulose 회수)

  • Kim, Sung-Bae;Kim, Chang, Joon
    • KSBB Journal
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    • v.20 no.4
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    • pp.317-322
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    • 2005
  • Various recovery methods were investigated to maximize hemicellulose recovery from lignocellulosic material hydrolyzed by pure water. The pretreatment conditions of water hydrolysis were $170\~180^{\circ}C$ and 1 hour of reaction time. The percentage of hemicellulose solubilized increased as the temperature increased from 170 to $180^{\circ}C$. However, significant decomposition of sugar was observed at temperature of $180^{\circ}C$. From the results of water hydrolysis, the total amount of glucan in solid residue and liquid hydrolyzate was close to the total glucan in the original biomass. For hemicellulose, however, there was a significant difference between both contents. To prove this difference, various recovery methods were proposed. From the total sugar accountability (sugar in liquid + sugar in solid), it was confirmed that hemicellulose recovery in the hydrolyzate was increased if the product including both hydrolyzate and solid residue was physically stimulated by such as heating and ultrasound irradiation. This indicated that, in commercial scale processes that much bigger substrate sizes are used and a sufficient amount of leaching solvent can not be used after pretreatment, a significant amount of oligomers could be trapped in the solid matrix.

Photocatalytic hydrogen production by water splitting using novel catalysts under UV-vis light irradiation

  • Marquez, Francisco;Masa, Antonio;Cotto, Maria;Garcia, Abraham;Duconge, Jose;Campo, Teresa;Elizalde, Eduardo;Morant, Carmen
    • Advances in Energy Research
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    • v.2 no.1
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    • pp.33-45
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    • 2014
  • Photocatalytic hydrogen generation by water splitting ($H_2O_{(1)}{\rightarrow}H_2_{(g)}+1/2O_2_{(g)}$) has been studied on photocatalysts based on Zn, Cd, Fe and Cu, synthesized by coprecipitation. Iron and copper nanoparticles were incorporated as cocatalysts to enhance the photocatalytic activity of the ZnCd solid solution. The effect of the different synthesis parameters (temperature, elemental atomic ratios, amount of Cu and Fe incorporated in the catalyst and calcination temperature) on the photocatalytic production of hydrogen has been studied in order to determine the best experimental synthesis conditions. The catalysts have been characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and BET. The experiments of photocatalytic water splitting were performed in aqueous solution of the photocatalysts previously dispersed in a soft ultrasound bath. The photocatalysts were irradiated under different lights ranging from 220 to 700 nm. The photocatalytic activity was found to be clearly dependent on the specific area of the photocatalyst.