• Title, Summary, Keyword: Microwave irradiation

Search Result 283, Processing Time 0.043 seconds

Effect of Microwave Irradiation Time on Microwave-Assisted Weak Acid Protein Hydrolysis

  • Kim, Dahee;Joo, Minhee;Lee, Dabin;Nguyen, Huu-Quang;Kim, Jeongkwon
    • Mass Spectrometry Letters
    • /
    • v.10 no.3
    • /
    • pp.79-83
    • /
    • 2019
  • Horse heart myoglobin (MYG) and bovine serum albumin (BSA) were hydrolyzed by microwave-assisted weak-acid hydrolysis for 10, 20, 30, 40, 50, and 60 min using 2% formic acid (FA) at $100^{\circ}C$. Generally, the number of identified peptides increased with increasing irradiation time, indicating that the duration of microwave irradiation is linked to the efficiency of hydrolysis. For MYG, irradiation for 60 min provided the highest number of identified peptides, the greatest sequence coverage values and the highest MASCOT score values among the investigated irradiation times. Irradiation of BSA for 50 min, however, yielded a greater number of peptides than irradiation for 60 min due to the generation of miscleaved peptides after microwave irradiation for 50 min.

Effects of Microwave Irradiation on the Composition of Swine Manure and Crystallization of MAP (극초단파 조사가 돈분뇨의 성상과 MAP 결정화 반응에 미치는 영향)

  • Cho, Joon-Hee;Ra, Chang-Six
    • Journal of Animal Science and Technology
    • /
    • v.51 no.1
    • /
    • pp.75-80
    • /
    • 2009
  • Composition changes of swine manure and the effects on MAP ($MgNH_4PO_46H_2O$) crystallization by microwave irradiation were examined. The concentration of ${PO_4}^{3-}$ was increased within a fixed period of time and then decreased, but $NH_4$-N was reduced continuously during microwave irradiation. Concentration of ${PO_4}^{3-}$ was started to reduce just from the point of foam formation during microwave irradiation, and the temperature at that time was always $49^{\circ}C$ irrespectively to microwave irradiation rate. Inorganic carbon was reduced with microwave irradiation, but soluble organic carbon (TOCs) was increased proportionally. Crystallization rate under conditions of non-microwave irradiation, irradiation up to $93^{\circ}C$ and $48^{\circ}C$ was 87.8%, 87.3% and 98.5%, respectively, showing 10% enhancement when irradiated up to $48^{\circ}C$. However, removal efficiency of ammonia nitrogen was proportional to the microwave irradiation rate or duration, obtaining 2.5%, 4.5% and 10.2%, respectively. Based on these results, it would be a useful strategy to irradiate microwave up to $49^{\circ}C$ to enhance MAP crystallization rate by changing the ionic pattern of nutrients in the manure. Meanwhile, provision of enough microwave irradiation rate might be needed to achieve high $NH_4$-N removal.

Improvement of Device Characteristic on Solution-Processed InGaZnO Thin-Film-Transistor (TFTs) using Microwave Irradiation

  • Moon, Sung-Wan;Cho, Won-Ju
    • JSTS:Journal of Semiconductor Technology and Science
    • /
    • v.15 no.2
    • /
    • pp.249-254
    • /
    • 2015
  • Solution-derived amorphous indium-gallium-zinc oxide (a-IGZO) thin-film-transistor (TFTs) were developed using a microwave irradiation treatment at low process temperature below $300^{\circ}C$. Compared to conventional furnace-annealing, the a-IGZO TFTs annealed by microwave irradiation exhibited better electrical characteristics in terms of field effect mobility, SS, and on/off current ratio, although the annealing temperature of microwave irradiation is much lower than that of furnace annealing. The microwave irradiated TFTs showed a smaller $V_{th}$ shift under the positive gate bias stress (PGBS) and negative gate bias stress (NGBS) tests owing to a lower ratio of oxygen vacancies, surface absorbed oxygen molecules, and reduced interface trapping in a-IGZO. Therefore, microwave irradiation is very promising to low-temperature process.

Effect of Microwave Irradiation on Crystallinity and Pasting Viscosity of Corn Starches Different in Amylose Content

  • Lee, Su-Jin;Sandhu, Kawaljit Singh;Lim, Seung-Taik
    • Food Science and Biotechnology
    • /
    • v.16 no.5
    • /
    • pp.832-835
    • /
    • 2007
  • Moisture content of normal, waxy, and high amylose com starches was adjusted to 10-35%, and irradiated in a microwave oven. The effect of microwave irradiation on the crystalline structure of starch was measured by using a differential scanning calorimetry (DSC), and X-ray diffractometry. Pasting viscosity profile was also determined by using a rapid viscoanalyzer (RVA). For all the 3 types of starches tested, the rate of temperature increase by the microwave irradiation was faster and more rapidly reached the maximum temperature of the pressure bomb ($120^{\circ}C$) when the moisture content was higher. X-ray diffraction and DSC data revealed that the microwave irradiated starch underwent partial disruption of crystalline structure. RVA studies showed that the irradiation caused significant reductions in maximal viscosity and breakdown, whereas pasting temperature was increased. Overall trends revealed that the microwave irradiation on the starch containing limited moisture content (less than 35%) provided the effects similar to the heat moisture treatment. These effects became more significant when the moisture content was higher. Compared to waxy com starch, normal, and high amylose com starches appeared to be more susceptible to the microwave irradiation.

Effect of Microwave Irradiation and Chemical Conditioning for Dewatering Characteristics of Sludge (슬러지의 탈수 특성에 대한 마이크로파와 약품개량의 영향)

  • Park, Sang-Sook;Kang, Hwa-Young;Wang, Seung-Ho
    • Journal of Korean Society of Environmental Engineers
    • /
    • v.27 no.7
    • /
    • pp.732-738
    • /
    • 2005
  • The purpose of this study is the presentation of the proper microwave treatment conditions by means of the investigation of the effect of microwave irradiation on the dewaterability and dryability of sludge. For the improving of dewatering efficiency of sludge using the microwave, the proper time of microwave irradiation is very important. The dewatering efficiency of thickening sludge conditioned by microwave irradiation for proper time was considerably improved with reducing of capillary suction time from 52.3 sec to 30.8 sec, and the sludge conditioned by microwave irradiation had contained the moisture of 81.4% after that pressure filtrationed. The result of drying characteristics of dewatered sludge using the microwave irradiation and furnace heating, for drying of sludge to moisture of below 55%, microwave irradiation time was required 3 min, whereas, furnace heating was required 40 min at $105^{\circ}C$, 20 min at $170^{\circ}C$ and 9 min at $300^{\circ}C$, respectively. We certified that the drying of dewatered sludge using the microwave irradiation was effectively reduction of moisture of sludge compare to traditional heating method.

Quality Characteristics of Pan Bread Depending on the Time of Microwave Irradiation Time (Microwave 조사 시간에 따른 식빵의 품질 특성)

  • Park, Sang-Jun;An, Hye-Lyung;Lee, Kwang-Suck
    • Journal of the East Asian Society of Dietary Life
    • /
    • v.20 no.3
    • /
    • pp.423-432
    • /
    • 2010
  • In order to streamline bread making process that is time-consuming in regard to the characteristics of process, this study focused on microwave irradiation to dough and raising its temperature to monitor potential variations of dough properties and bread quality, and also examined optimum irradiation time to deduce effective ways for streamlining bread making process. According to analyze dough properties depending on microwave irradiation time, it was found that microwave heat (MWH) 2 showed the highest specific volume and oven spring of all and the lowest hardness (i.e. the highest softness). Moreover, MWH 2 scored the highest points in overall preference under sensory characteristics. As a result, it found that 80-second heating of 700 g bread dough, when exposed to microwave irradiation, contributed to the highest quality of bread.

Changes in Nutritive Value and Digestion Kinetics of Canola Seed Due to Microwave Irradiation

  • Ebrahimi, S.R.;Nikkhah, A.;Sadeghi, A.A.
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.23 no.3
    • /
    • pp.347-354
    • /
    • 2010
  • This study aimed to evaluate effects of 800 W microwave irradiation for 2, 4 and 6 min on chemical composition, antinutritional factors, ruminal dry matter (DM) and crude protein (CP) degradability, and in vitro CP digestibility of canola seed (CS). Nylon bags of untreated or irradiated CS were suspended in the rumen of three bulls from 0 to 48 h. Protein subfractions of untreated and microwave irradiated CS before and after incubation in the rumen were monitored by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Microwave irradiation had no effect on chemical composition of CS (p>0.05). There was a linear decrease (p<0.001) in the phytic acid and glucosinolate contents of CS as irradiation time increased. Microwave irradiation for 2, 4 and 6 min decreased the phytic acid content of CS by 8.2, 27.6 and 48.6%, respectively. The total glucosinolate contents of CS microwave irradiated for 2, 4 and 6 min decreased by 41.5, 54.7 and 59.0% respectively, compared to untreated samples. The washout fractions of DM and CP and degradation rate of the b fraction of CP decreased linearly (p<0.001) as irradiation time increased. Microwave irradiation for 2, 4 and 6 min decreased effective degradability (ED) of CP at a ruminal outflow rate of 0.05 $h^{-1}$ by 4.7, 12.3 and 21.0%, respectively. Microwave irradiation increased linearly (p<0.001) in vitro CP digestibility of ruminally undegraded CS collected after 16 h incubation. Electrophoresis results showed that napin subunits of untreated CS disappeared completely within the zero incubation period, whereas cruciferin subunits were degraded in the middle of the incubation period (16 h incubation period). In 4 and 6 min microwave irradiated CS, napin subunits were degraded after 4 and 16 h incubation periods, respectively, and cruciferin subunits were not degraded untile 24 h of incubation. In conclusion, it seems that microwave irradiation not only protected CP of CS from ruminal degradation, but also increased in vitro digestibility of CP. Moreover, microwave irradiation was effective in reducing glucosinolate and phytic acid contents of CS.

Oscillatory Reaction in a Liquid-Liquid System with Nano-Particle Under Microwave Irradiation

  • Asakuma, Y.;Takahashi, S.;Saptoro, A.;Maeda, Y.;Araki, N.
    • Particle and aerosol research
    • /
    • v.11 no.3
    • /
    • pp.77-85
    • /
    • 2015
  • A Belousov-Zhabotinsky reaction in a liquid-liquid system under microwave radiation was observed under non-stirring conditions. To control this non-equilibrium reaction, nano-particle, which is active under microwave irradiation, was added to the solution. Color changes of the solution during the oscillatory reaction were found to be influenced by the irradiation power although the droplet temperature was equal to the temperature of surrounding oil. During the irradiation, the period of oscillation became shorter because the reaction rate was faster. It could also be observed that there is possibility to eliminate oscillatory behaviors of the reaction using higher power of microwave. The possibility of controlling non-linear reaction using microwave was shown since microwave can easily travel through oil phase and reach water phase.

Synthesis and Characterization of Some Quinazoline Derivatives as Potential Antimicrobial Agents under Microwave Irradiation

  • Mehta, Sarika;Swarnkar, Neelam;Vyas, Madhuri;Vardia, Jitendra;Punjabi, Pinki B.;Ameta, Suresh C.
    • Bulletin of the Korean Chemical Society
    • /
    • v.28 no.12
    • /
    • pp.2338-2343
    • /
    • 2007
  • Under the framework of green chemistry, an efficient and extremely fast procedure for the synthesis of 5a-h through four-step procedure starting from 2-arylidenetetralin-1-one 1a-d under microwave irradiation is described. A considerable increase in the reaction rate has been observed with better yield. The structures of the synthesized compounds have been characterized on the basis of their elemental analysis and spectral data. Synthesized compounds 5a-h was evaluated for their antimicrobial activity. Some of the compounds exhibited appreciable activity.