• Title/Summary/Keyword: Current treatment

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A mini-review on microplastics in drinking water treatment processes (정수처리장 내의 미세플라스틱의 유입 및 처리기술 현황에 관한 고찰)

  • Choi, Byeonggyu;Kim, Jiyoon;Choi, Soohoon
    • Journal of Korean Society of Water and Wastewater
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    • v.34 no.5
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    • pp.357-371
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    • 2020
  • Microplastics have become a rising issue in due to its detection in oceans, rivers, and tap water. Although a large number of studies have been conducted on the detection and quantification in various water bodies, the number of research conducted on the removal and treatment of microplastics are still comparatively low. In the current research, the inflow and removal of microplastics were investigated for various drinking water treatment plants around the world. Addition to the investigation of filed research, a survey was also conducted on the current research trend on microplastic removal for different treatment processes in the drinking water treatment plants. This includes the researches conducted on coagulation/flocculation, sedimentation, dissolved air flotation, sand filtration and disinfection processes. The survey indicated mechanisms of microplastic removal in each process followed by the removal characteristics under various conditions. Limitations of current researches were also mentioned, regarding the gap between the laboratory experimental conditions and field conditions of drinking water treatment plants. We hope that the current review will aid in the understanding of current research needs in the field of microplastic removal in drinking water treatment.

Study on Anodizing at Constant Current for Sealing Treatment of Nano-diamond Powder (나노 다이아몬드 분말 봉공처리 적용을 위한 정전류에서의 알루미늄 양극산화 제조 연구)

  • Kang, Soo Young;Lee, Dae Won
    • Journal of Powder Materials
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    • v.21 no.2
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    • pp.114-118
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    • 2014
  • In this study, an aluminum oxide layer for sealing treatment of nano-diamond powder was synthesized by anodizing under constant current. The produced pore size and oxide thickness were investigated using scanning electron microscopy. The pore size increased as the treatment time increased, current density increased, sulfuric acid concentration decreased, which is different from the results under constant voltage, due to a dissolution of the oxide layers. The oxide layer thickness by the anodizing increased as temperature, time, and current density increased. The results of this study can be applied to optimize the sealing treatment process of nano-diamond particles of 4-10 nm to enhance the resistances of corrosion and wear of the matrix.

A Study on the Problem about Oriental Treatment Fee Based on Valuation of Resources (투입자원 평가에 근거한 한방 침구 부항 시술 수가의 문제점에 관한 연구)

  • Kim, Yong-Ho;Lee, Won-Hui;Chang, Hye-Jung;Lim, Sa-Bi-Na
    • The Journal of Korean Medicine
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    • v.29 no.1
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    • pp.15-24
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    • 2008
  • Objectives : The purpose of this study is to reexamine current oriental medical treatment fees based on valuation of input resources which are the treating time, the treatment's difficulty, and the material cost. Methods : This study obtained the following results by reviewing the answers given by 172 oriental medical doctors from March 1 to April 15, 2006. To investigate material cost, we took inventory of treatment materials used by 2 oriental hospitals. Results : The current system does not reflect well enough the treating time and treatment's difficulty. Considering current oriental treatment fees, material costs are too much of doctors' fees. Especially, Wang-ssuk-dduem, which is another form of moxibustion treatment, was spent as much as 74.6% on materials cost. Conclusions : The findings suggest the current oriental treatment fees should be revised to reflect the actual input resources into oriental medical doctor activities and to avoid a distortion of physicians' behavior.

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A Retrospective Statistical Analysis of Miniscalpel Needle Therapy for Herniated Intervertebral Disc or Spinal Stenosis

  • Kim, Jae Ik;Jeong, Jeong Kyo;Kim, Myung Kwan;Jeon, Ju Hyun;Kim, Eun Seok;Kim, Young Il
    • Journal of Acupuncture Research
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    • v.35 no.4
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    • pp.226-237
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    • 2018
  • Background: This study examined the characteristics and prognosis of patients admitted to the Dunsan Korean medicine hospital for treatment of herniated intervertebral disc (HIVD) or spinal stenosis with Miniscalpel needle therapy (MSN). Methods: Patients were admitted to the Dunsan Korean medicine hospital from January 01, 2016 to September 30, 2017 for the treatment of HIVD or spinal stenosis with MSN. Crossover analysis, Independent sample t test, one-way ANOVA, multiple linear regression analysis, and binary logistic regression analysis were performed. Results: Crossover analysis showed statistically significant differences in treatment methods according to gender, current pain according to the disease duration, satisfaction of MSN according to disease duration, treatment methods, and intention of re-treatment with MSN according to treatment methods. Independent t test and one-way ANOVA showed that there was a difference in current Numeric Rating Scale (NRS) according to disease duration, and difference between discharge and current NRS, and number of MSN according to disease. Multiple linear regression analysis showed that age, disease duration, and number of MSN affect discharge NRS, disease duration, and number of MSN affect current NRS, and Western medical treatment after MSN, discharge NRS, and current NRS affect satisfaction of MSN. Binary logistic regression analysis showed that discharge NRS affects current pain, and gender, discharge NRS, and treatment methods affect intention of re-treatment with MSN. Conclusion: Characteristics, prognosis, satisfaction and variables affecting prognosis of MSN were statistically significant, indicating that more systematic studies are required to further examine the effects of MSN on HIVD or spinal stenosis.

The Improvement of the Off-Current Characteristics in the Short Channel a-Si:H TFTs

  • Bang, J.H.;Ahn, Y.K.;Ryu, W.S.;Kim, J.O.;Kang, Y.K.;Yang, J.Y.;Yang, M.S.;Kang, I.B.;Chung, I.J.
    • 한국정보디스플레이학회:학술대회논문집
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    • 2008.10a
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    • pp.867-869
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    • 2008
  • We have investigated the effects of hydrogen plasma treatment by PECVD (Plasma Enhanced Chemical Vapor Deposition) in the back channel region, the method for reducing the off state leakage current which increases with the short channel length of a-Si:H TFTs. To improve the off current characteristics, we analyzed the hydrogen plasma treatment with various RF power and plasma treatment times of PECVD. As the result of hydrogen plasma treatment in the back channel region it was remarkably reduced the off current level of 2um channel length TFT.

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Effect of Additional Electrical Current on Adhesion Strength between Copper and Polyimide Films (인가 전류가 구리 도금 피막과 폴리이미드 필름의 접합력에 미치는 영향)

  • Lee, Jang-Hun;Han, Yoonsung;Lee, Ho-Nyun;Hur, Jin-Young;Lee, Hong Kee
    • Journal of Surface Science and Engineering
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    • v.46 no.1
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    • pp.9-15
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    • 2013
  • The effect of the additionally applied electrical current on the adhesion strength between electroless Cu and polyimide films was investigated. Peel tests were performed after applying electrical current within the range from 0.1 to 100 mA for the duration from 1 to 30 minutes. Sample with more than 1 mA of additional electrical current for 1 minute showed higher adhesion strength than that without additional electrical current. However, samples with 10 mA of additional electrical current for more than 10 miniutes showed the degradation of adhesion strength. Ra and RMS values of the peeled polyimide surface were proportional to the adhesion strength though there were no significant changes in the morphology of the peeled surfaces with varied amount and time-length of additional electrical current. Applying electrical current could increase the density of chemical bonding, which results in increase of the adhesion strength between copper and polyimide. However, in the case of applying additional electrical current for excessive amount or time, the degradation of the adhesion strength owing to the formation of copper oxide at the interface could occur.

Reverse-bias Leakage Current Mechanisms in Cu/n-type Schottky Junction Using Oxygen Plasma Treatment

  • Kim, Hogyoung
    • Transactions on Electrical and Electronic Materials
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    • v.17 no.2
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    • pp.113-117
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    • 2016
  • Temperature dependent reverse-bias current-voltage (I-V) characteristics in Cu Schottky contacts to oxygen plasma treated n-InP were investigated. For untreated sample, current transport mechanisms at low and high temperatures were explained by thermionic emission (TE) and TE combined with barrier lowering, respectively. For plasma treated sample, experimental I-V data were explained by TE or TE combined with barrier lowering models at low and high temperatures. However, the current transport was explained by a thermionic field emission (TFE) model at intermediate temperatures. From X-ray photoemission spectroscopy (XPS) measurements, phosphorus vacancies (VP) were suggested to be generated after oxygen plasma treatment. VP possibly involves defects contributing to the current transport at intermediate temperatures. Therefore, minimizing the generation of these defects after oxygen plasma treatment is required to reduce the reverse-bias leakage current.

The Investigation of COD Treatment and Energy Consumption of Urban Wastewater by a Continuous Electrocoagulation System

  • DEDE SAGSOZ, Yesim;YILMAZ, Alper Erdem;EKMEKYAPAR TORUN, Fatma;KOCADAGISTAN, Beyhan;KUL, Sinan
    • Journal of Electrochemical Science and Technology
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    • v.13 no.2
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    • pp.261-268
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    • 2022
  • In this study, electrochemical treatment of urban wastewater with electrical conductivity of 1000 μS cm-1 and chemical oxygen demand of 250 mg L-1 was investigated using the variables of initial pH value, current density and flow rate. Electrocoagulation was used, in which aluminum and stainless steel were selected, as the electrochemical treatment process. The electrocoagulation process was operated in continuous mode. The data obtained in experimental studies show that the best COD removal efficiency occurred in experiments where the initial pH value was 6. The increase in current density from 5 A to 15 A decreased the removal efficiency from 79 to 67%. The increase in flow rate under constant current density also reduced the efficiency of removal as expected. In experiments in which current density and flow rate were examined together, the increase in flow rate allowed the application of higher current densities. This situation led to considerable reductions in energy consumption values, even if the COD removal efficiency did not significantly increase. The high COD removal obtained with the use of high flow rate and high current density indicates that the electrocoagulation process can be used for high flow rate municipal wastewater treatment.

Treatment Rate-up Methods in the Oriental Medicine (한의학 치료율 제고 방안에 관한 연구)

  • Lee Sun-Dong
    • Journal of Society of Preventive Korean Medicine
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    • v.3 no.1
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    • pp.35-54
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    • 1999
  • This thesis shows about the meaning of treatment rate increasing, the current treated level and the reason of low treatment rate and increasing methods. 1. Treatment rate incresing means high treat level within short time, keeping treatment effect for a long time as well as raising treatment rate. 2. The current by diseases each others completed treatment rate of oriental medicine is 14.0% to 89.7%$(mean:\;{\pm}40.0%)$. Therefore the rate is show too low. 3. The reasons of low treatment rate; low academic level of oriental, academic limitation, clinic and prevention problem of oriental medicine, lack of medical approch suitable for current diseases and symptoms, mostly incurrable diseases using oriental medicine, lack of preventive education, disappropriate medical service and nonspecialty of the treatment, etc. 4. The next methods for incresing the treatment rate must be improved; such as accurate establishment of process that diagnosis symptoms and treats them, system research of microdiagnosis, positive treatment with medicine and nonmedicine method at the same time, appropriate subdivision and actualization of clinical basic research, research of dose and response, diversity of treatment methods and forms, development of treatment service and prevention based on health level, enormous change as cure medicine and opening-up of new disease field, specialization of medical examination, reinforcement of public medical part and herbal drugs use with same origin, mental and pysical stability of patients, accurate extract and oral drinking ways, etc.

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Analysis of Heat Treatment Process Conditions for Output Characteristics of Permalloy Core on Current Sensors using DOE (실험계획법을 이용한 퍼멀로이 전류 코어 센서의 출력특성에 관한 열처리 공정조건 분석)

  • Kim, Young Shin;Kim, Yoon Sang;Jeon, Euy Sik
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.19 no.4
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    • pp.16-23
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    • 2020
  • An electric vehicle operates at high currents and requires real-time monitoring of the entire system for ensuring efficiency and safety of the vehicle. Current sensors are applied to drive the motors, inverters, and battery control systems, and are the key components to ensure constant monitoring of the magnitude and waveforms of the operating current. In this study, a heat treatment process condition to influence the performance of Permalloy current sensors was developed; the correlation between the output capacity, low-temperature characteristics, and high-temperature characteristics of the current sensor was studied; and the process was optimized to meet the required output accuracy and temperature characteristics.