• Title/Summary/Keyword: 혼합정수법

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MXene Based Composite Membrane for Water Purification and Power Generation: A Review (정수 및 발전을 위한 맥신(MXene) 복합막에 관한 고찰)

  • Seohyun Kim;Rajkumar Patel
    • Membrane Journal
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    • v.33 no.4
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    • pp.181-190
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    • 2023
  • Wastewater purification is one of the most important techniques for controlling environmental pollution and fulfilling the demand for freshwater supply. Various technologies, such as different types of distillations and reverse osmosis processes, need higher energy input. Capacitive deionization (CDI) is an alternative method in which power consumption is deficient and works on the supercapacitor principle. Research is going on to improve the electrode materials to improve the efficiency of the process. A reverse electrodialysis (RED) is the most commonly used desalination technology and osmotic power generator. Among many studies conducted to enhance the efficiency of RED, MXene, as an ion exchange membrane (IEM) and 2D nanofluidic channels in IEM, is rising as a promising way to improve the physical and electrochemical properties of RED. It is used alone and other polymeric materials are mixed with MXene to enhance the performance of the membrane further. The maximum desalination performances of MXene with preconditioning, Ti3C2Tx, Nafion, and hetero-structures were respectively measured, proving the potential of MXene for a promising material in the desalination industry. In terms of osmotic power generating via RED, adopting MXene as asymmetric nanofluidic ion channels in IEM significantly improved the maximum osmotic output power density, most of them surpassing the commercialization benchmark, 5 Wm-2. By connecting the number of unit cells, the output voltage reaches the point where it can directly power the electronic devices without any intermediate aid. The studies around MXene have significantly increased in recent years, yet there is more to be revealed about the application of MXene in the membrane and osmotic power-generating industry. This review discusses the electrodialysis process based on MXene composite membrane.

Separation of Antioxidants and Glucose from Grape Skin Extract Using Polyethylene Glycol and Sodium Citrate (폴리에틸렌글리콜과 구연산 나트륨을 이용하여 포도껍질 추출물에서 항산화물질과 포도당 분리)

  • Eun Min Shin;Yeong Eun Joo;Su Min Jung;Jaechan Suh;Chang-Joon Kim
    • Clean Technology
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    • v.29 no.2
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    • pp.109-117
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    • 2023
  • The purpose of this study is to develop a method for separating antioxidants and sugars from grape skin extract. The extract was first mixed with a variety of organic solvents to investigate whether the separation was feasible. When employing acetone, ethanol, dimethylsulfoxide, or dimethylformamide, the organic solvent-extract combination formed a single phase. However, when benzene, ethyl acetate, or n-hexane was added to the extract, the mixture separated into an organic and an aqueous phase and the pigments remained in the aqueous phase. On the other hand, when polyethylene glycol-2,000 (PEG-2000) and sodium citrate were added to the extract, the mixture was separated into three layers, with the majority of the flavonoids migrating to the top layer and 53% of the extract's glucose migrating to the bottom layer. The top layer had significant antioxidant activity, whereas the bottom layer showed no antioxidant activity. The glucose recovery in the bottom layer increased as the molecular weight of PEG increased and the highest recovery (67%) was observed when PEG-8,000 was added. The highest flavonoid separation was observed with PEG-2,000, followed by PEG-8,000 and PEG-400. The flavonoid separation when PEG-2,000 was added resulted in a flavonoid recovery of 48% and 0.2% from the top and bottom layers, respectively. Examining the effect of the separated solution using the agar disc diffusion method on yeast cell growth confirmed that the addition of the extract, the top, and the bottom layer did not inhibit cell growth.

Effects of Aromatherapy on Depression, Anxiety and the Autonomic Nervous System in Breast Cancer Patients Undergoing Adjuvant Radiotherapy (방사선 요법을 받는 유방암 환자에게 적용한 아로마 요법이 우울, 불안 및 자율신경계 반응에 미치는 효과)

  • Yun, Sun-Hee;Cha, Jung-Hee;Yoo, Yang-Sook;Kim, Yeong-In;Chung, Su-Mi;Jeong, Hea-Lim
    • Journal of Hospice and Palliative Care
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    • v.15 no.2
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    • pp.68-76
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    • 2012
  • Purpose: The study was designed to verify effects of aromatherapy on depression, anxiety and the autonomic nervous system in breast cancer patients who are undergoing adjuvant radiotherapy. Methods: Data were collected from November 2006 through March 2007 at the C university hospital in Seoul. The study included 33 patients and they were assigned to three groups. Group I had aroma oil inhalation for 2 minutes per time, three times a day for six weeks whereas Group II and a control group inhaled aroma oil for 2 minutes per time, once a day for six weeks. For Groups I and II, a mixture of lemon, lavender, rosewood and rose essential oils were used while control group inhaled tea tree oil. Results: Depression was significantly decreased in patients in the experimental groups only. In Groups I and II patients, anxiety level was lower than that in control patients. Patients in Groups I and II also showed stronger physical resistance to stress than control group patients. Conclusion: Aromatherapy should be considered as a method that can significantly decrease depression in breast cancer patients who are undergoing adjuvant radiotherapy.