• Title/Summary/Keyword: Microwave treatment

Search Result 330, Processing Time 0.03 seconds

Solid-phase Synthesis of 7-Aryl-benzo[b][1,4]oxazin-3(4H)-one Derivatives on a BOMBA Resin Utilizing the Smiles Rearrangement

  • Lee, Ji-Min;Yu, Eun-Ae;Park, Joo-Yeon;Ryu, In-Ae;Shin, Dong-Soo;Gong, Young-Dae
    • Bulletin of the Korean Chemical Society
    • /
    • v.30 no.6
    • /
    • pp.1325-1330
    • /
    • 2009
  • A general method has been developed for the solid phase synthesis of drug-like 7-aryl-benzo[b][1,4]oxazin-3(4H)- one derivatives 6. The method relies on a novel, microwave irradiation promoted cyclization reaction of the BOMBA resin bound, N-substituted-$\alpha$-(2-chloro-4-bromophenoxy)acetamide 3 that takes place via a Smiles rearrangement. The 7-bromobenzo[1,4]oxazine 4, produced in this process is converted to 7-aryloxazin analogs 5 by utilizing Suzuki coupling with various substituted arylboronic acids. Finally, the target 7-aryl-benzo[b][1,4]oxazin-3(4H)-ones 6 are liberated from the resin by treatment with 5% TFA. The progress of the reactions involved in this preparative route can be monitored by using ATR-FTIR spectroscopy on a single bead. The target compounds, obtained by using this five-step sequence, are produced in high yields and purities.

Surface Modification with Atmospheric Microwave Agron Plasma Jet Assisted with Admixture of H2O2 and Analysis of Plasma Characteristics

  • Won, I.H.;Shin, H.K.;Kwon, H.C.;Kim, H.Y.;Kang, S.K.;Lee, J.K.
    • Proceedings of the Korean Vacuum Society Conference
    • /
    • 2013.02a
    • /
    • pp.544-545
    • /
    • 2013
  • Recently, low-temperature atmospheric-pressure plasmas have been investigated [1,2] for biomedical applications and surface treatments. Experiments for improving hydrophilicity of stainless steel (SUS 304) plate with atmospheric microwave argon and H2O2 mixture plasma jet [3] were carried out and experimental measurements and plasma simulations were conducted for investigating the characteristics of plasma for the process. After 30 s of low power (under 10 W) and low temperature (under $50^{\circ}C$) plasma treatment, the water contact angle decreased rapidly to around $10^{\circ}$ from $75^{\circ}$ and was maintained under $30^{\circ}$ for a day (24 hours). The surface free energy, calculated from the contact angles, increased. The chemical properties of the surface were examined by X-ray Photoelectron Spectroscopy (XPS) and the surface morphology and roughness were examined by Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM) respectively. The characteristics of plasma sources with several frequencies were investigated by Optical Emission Spectroscopy (OES) measurement and one-dimensional Particle-in-Cell (PIC) simulation and zero-dimensional global simulation [4]. The relation between plasma components and the efficacy of the surface modification were discussed.

  • PDF

Maximizing biogas production by pretreatment and by optimizing the mixture ratio of co-digestion with organic wastes

  • Lee, Beom;Park, Jun-Gyu;Shin, Won-Beom;Kim, Beom-Soo;Byun, Byoung-su;Jun, Hang-Bae
    • Environmental Engineering Research
    • /
    • v.24 no.4
    • /
    • pp.662-669
    • /
    • 2019
  • Anaerobic digestion is a popular sewage sludge (Ss) treatment method as it provides significant pollution control and energy recovery. However, the low C/N ratio and poor biodegradability of Ss necessitate pretreatment methods that improve solubilization under anaerobic conditions in addition to anaerobic co-digestion with other substrates to improve the process efficiency. In this study, three pretreatment methods, namely microwave irradiation, ultrasonication, and heat treatment, were investigated, and the corresponding improvement in methane production was assessed. Additionally, the simplex centroid design method was utilized to determine the optimum mixture ratio of food waste (Fw), livestock manure (Lm), and Ss for maximum methane yield. Microwave irradiation at 700 W for 6 min yielded the highest biodegradability (62.0%), solubilization efficiency (59.7%), and methane production (329 mL/g VS). The optimum mixture ratio following pretreatment was 61.3% pretreated Ss, 28.6% Fw, and 10.1% Lm. The optimum mixture ratio without pretreatment was 33.6% un-pretreated Ss, 46.0% Fw, and 20.4% Lm. These results indicate that the choice of pretreatment method plays an important role in efficient anaerobic digestion and can be applied in operational plants to enhance methane production. Co-digestion of Ss with Fw and Lm was also beneficial.

Effect of Some Treatments on the Autolysis of Baker's Yeast (Saccharomyces cerevisiae) (빵효모의 자기분해에 대한 몇가지 처리의 효과)

  • Choi, Im-Soon;Shim, Kyung-Mi
    • Journal of the Korean Society of Food Science and Nutrition
    • /
    • v.13 no.3
    • /
    • pp.313-318
    • /
    • 1984
  • Some chemical, biochemical and physical treatments on the baker's yeasts (Saccharomyces cerevisiae) before 12-hour digestion at $50^{\circ}C$ were made to accelerate their autolysis. Dilute alkali treatment with 0.01N-NaOH solution showed a considerable increase in soluble nitrogen extraction only in the 6-hour initial autolysis. The addition of fresh yeast autolysate, 10% to the yeast slurry, could increase the autolysis rate from 65% to 83%. Microwave treatment of yeast slurry for 40 seconds also raised the autolysis rate by about 15%, while longer exposures to the microwave accompanying high temperatures repressed the autolysis process. Extrusion of the yeast cells with high pressures of 16,000 to 20,000 psi brought about significantly higher autolysis rate until the digestion time of 9 hours, but thereafter it showed a gradual drop in soluble nitrogen extraction.

  • PDF

Application of cold atmospheric microwave plasma as an adjunct therapy for wound healing in dogs and cats

  • Jisu Yoo;Yeong-Hun Kang;Seung Joon Baek;Cheol-Yong Hwang
    • Journal of Veterinary Science
    • /
    • v.24 no.4
    • /
    • pp.56.1-56.13
    • /
    • 2023
  • Background: Cold atmospheric plasma is a novel innovative approach for wound care, and it is currently underrepresented in veterinary medicine. Objectives: To investigate the efficacy and safety of using cold atmospheric microwave plasma (CAMP) as an adjunct therapy for wound healing in dogs and cats. Methods: Wound healing outcomes were retrospectively analyzed using clinical records of client-owned dogs and cats who were first managed through standard wound care alone (pre-CAMP period) and subsequently via CAMP therapy (CAMP period). The degree of wound healing was estimated based on wound size and a modified wound scoring system. Results: Of the 27 acute and chronic wounds included in the analysis, 81.48% showed complete healing after the administration of CAMP as an adjunct therapy to standard care. Most wounds achieved complete healing in < 5 weeks. Compared with the pre-CAMP period, the rate of wound healing significantly increased every week in the CAMP period in terms of in wound size (first week, p < 0.001; second week, p = 0.012; third week, p < 0.001) and wound score (first week, p < 0.001; second week, p < 0.001; third week, p = 0.001). No adverse events were noted except for mild discomfort and transient erythema. Conclusions: CAMP is a well-tolerated therapeutic option with immense potential to support the treatment of wounds of diverse etiology in small animal practice. Further research is warranted to establish specific criteria for CAMP treatment according to wound characteristics.

Effect of Heat Treatments on Physical Properties and in vitro Glucose, Bile Acid, and Cadmium Transport Retardation of Wax Gourd (Benincasa hispida) (동아의 물리적 특성 및 in vitro 포도당, 담즙산, 카드뮴 투과억제 효과에 대한 열처리 영향)

  • Ju, In-Ok;Jung, Gi-Tai;Ryu, Jeong;Kim, Young-Soo
    • Korean Journal of Food Science and Technology
    • /
    • v.35 no.6
    • /
    • pp.1117-1123
    • /
    • 2003
  • The effects of heat treatment on the physical and physical and physiological properties of wax gourd (Benincasa hispida) were examined. The applied heat treatments were autoclaved at $121^{\circ}C$ for 1 hr, boiled for 30 min, and microwaved at 680 W for 5 min. The water retention capacity (WRC) of the wax gourds was 9.43 g/g for the microwaved samples, 5.12 g/g for the boiled samples, 4.63 g/g for the raw samples, and 2.61 g/g for the autoclaved samples. Heat treatment caused to increase swelling by up to $4.4{\sim}7.8\;mL/g$. Calcium binding capacity of heat-treated wax gourd increased in the order of microwaved, boiled, raw, autoclaved samples. Scanning electron microscopy (SME) showed that autoclaving caused the most severe structural modifications, while microwave treatment produced the least modifications. The retarding effect on glucose and bile acid transport depended on the heat treatment. Only boiling showed the glucose retardation effect. Bile acid retardation effect increased in order of boiling (22.9%), autoclaving (17.1%), microwave treatment (14.3%), and raw wax gourd (8.6%). The cadmium retardation effect was significantly high in all samples.

Array of Slot-Sleeve Antennas for Hyperthermia Therapy

  • Park Soo-Man;Lim Yeongseog
    • Journal of electromagnetic engineering and science
    • /
    • v.5 no.3
    • /
    • pp.126-131
    • /
    • 2005
  • To increase the efficiency of an applicator during microwave hyperthermia therapy, first, the length from the antenna end to a slot is varied to get the optimal matching of the characteristic impedance at the frequency of 2.45 GHz. Using the electric and thermal constants of biological tissue, we compose a phantom to calculate temperature increment as well as the resonance characteristics and the SAR distributions. The proposed 3-slot sleeve antenna inserted in an applicator plays an effective role in increasing the therapy size in the view of heating performance as electromagnetic energy tends to concentrate on not feed point direction but treatment area. The SAR is then used in combination with a finite difference heat transfer equation to determine the temperature distribution. Also, in order to shorten treatment time and increase therapy size, a square-array structure is suggested and analyzed.

Enhanced thermomechanical properties of poly(ethylene oxide) and functionalized bacterial cellulose nanowhiskers composite nanofibers

  • Yun, Ok-Ja
    • Proceedings of the Korean Vacuum Society Conference
    • /
    • 2016.02a
    • /
    • pp.376-376
    • /
    • 2016
  • Poly(ethylene oxide) (PEO)/functionalized bacterial cellulose nanowhiskers (f-BCNW) (0.1 wt%) composite nanofibers were fabricated by electrospinning process and the thermomechanical properties were significantly enhanced more than the PEO and PEO/bacterial cellulose nanowhiskers (BCNW) (0.1 wt%) composite nanofibers. The functionalization of BCNW (f-BCNW) was performed by microwave plasma treatment for effects of nitrogen functionalization of chemically-driven BCNW. The N-containing functional groups of f-BCNW enhanced chemical bonding between the hydroxyl groups of the polymer chains in the PEO matrix and diameter size of PEO/f-BCNW (0.1 wt%) composite nanofibers were decreased more than PEO and PEO/BCNW (0.1 wt%) composite nanofibers on the same concentration. The strong interfacial interactions between the f-BCNW nanofillers and polymer matrix were improved the thermomechanical properties such as crystallization temperature, weight loss and glass transition temperature (Tg) compared to PEO and PEO/BCNW composites nanofibers. The results demonstrated that N2 plasma treatment of BCNW is very useful in improving thermal stability for bio-applications.

  • PDF

Detection of Bio-chemical by Boron-doped Diamond Electrode (붕소가 도핑된 다이아몬드 전극을 이용한 생체화학물질의 검출)

  • Kim, Gyu-Sik;Einaga, Y.;Fujishima, A.;Park, Soo-Gil
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 2001.11b
    • /
    • pp.569-572
    • /
    • 2001
  • Selective. highly stable determination of epinephrine(adrenalin) was achieved in cyclic voltammetric measurement carried out at electrochemically treated conductive boron-doped diamond electrode. Boron-doped diamond electrodes were prepared on single crystal Si wafers by microwave plasma chemical vapor deposition and $B_{2}O_{3}$ was dissolved in acetone/methanol(9:1) mixture solution so that the B/C weight ratio ca. $10^{4}ppm$. Epinephrine is a kind of catecholamines, which secreted from adrenal marrow cells. The serious problem to detection of epinephrine is the interference phenomena of electroactive constituent. including AA. In this study. electrochemical treatment of BDD was carried out to discriminate between epinephrine and AA responses. Experimental results showed that the peak potential of AA oxidation shift to the positive direction and the oxidation peak of epinephrine was unchanged. The effect of electrochemical treatment was maintained up to 40hrs.

  • PDF

Microwave and RF Heating for Medical Application under Noninvasive Temperature Measurement Using Magnetic Resonance

  • Nikawa, Yoshio;Ishikawa, Akira
    • Journal of electromagnetic engineering and science
    • /
    • v.10 no.4
    • /
    • pp.244-249
    • /
    • 2010
  • Recent development of magnetic resonance imaging (MRI) equipment enables interventional radiology (IVR) as diagnosis and treatment under MRI usage. In this paper, a new methodology for magnetic resonance (MR) scanner to apply not only diagnostic equipment but for treatment one is discussed. The temperature measuring procedure under MR is to measure phase shift of $T_1$, which is the longitudinal relaxation time of proton, for the position inside a sample material with the application of pulsed RF for heating inside the sample as artificial dielectrics. The result shows the possibility to apply MR as temperature measuring equipment and as a heating equipment for applying such as hyperthermia heating modality.