• Membrane and Water Treatment
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• v.10 no.4
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• pp.277-286
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• 2019

In 2014, the first demineralization plant, using nanofiltration (NF) membrane coupled with renewable energies was realized at Al Annouar high school of Sidi Taibi, Kenitra, Morocco. This project has revealed difficulties related to the membrane performances loss (pressure increase, flux decline, poor water quality of the produced water and increase of energy consumption), as consequences of membrane fouling. To solve this problem, an autopsy of the membrane was done in order to determine the nature and origin of the fouling. The samples of membrane and fouling were then analyzed by scanning electron microscopy using a scanning electron microscope (SEM) connected with an energy dispersive X-ray (EDX) detection system and X-ray diffractometer (XRD). Moreover, three cleaning solutions (hydrochloric acid, nitric acid and sulfuric acid) were tested and assessed in a single cleaning step to find the suitable one for the fouled membrane to regain its initial permeability and performances. The analysis of the experimental results showed that the fouling layer is mainly composed of calcium carbonate (inorganic fouling). Results showed also that the permeability is improved by the hydrochloric acid cleaning (pH=3) with a cleaning efficiency of 93%. Cleaning efficiency did not exceed 75 % with nitric acid (pH=3) and 40 % with sulfuric acid (pH=3).

• Journal of the Korean Applied Science and Technology
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• v.41 no.1
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• pp.9-18
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• 2024

Smilax china is known for its excellent antimicrobial, antioxidant, and anti-inflammatory properties. As a foundational study for applying the functionality of Smilax china extracts to cosmetics, it is necessory to investigate the concentration-dependent skin permation characteristics of the flavonoids in the extract, namely quercetin, catechin, and naringenin. Therefore, it serves as a crucial method for conducting this basic research on the functional aspects fo Smilax china extracts for cosmetic applications. This investigation focused on examining the percutaneous permeability characteristics of flavonoids originating from Smilax china. Applying Marzulli's definition, the Kp value of quercetin was categorized as "fast" at 0.1 mg/mL and "moderate" at 0.2 and 0.4 mg/mL. Notably, the permeation rate exhibited a decline with increasing concentration. For naringenin, Flux values were 0.69, 1.07, and 1.42 ㎍/hr/cm² at concentrations of 0.1, 0.2, and 0.4 mg/mL, respectively, with corresponding Kp values of 6.95, 5.34, and 3.56. Naringenin's Kp value fell into the "moderate" category across all concentrations, and as observed with quercetin, the permeation rate decreased with higher concentrations. Likewise, for catechin, Flux values were 0.75, 1.09, and 1.66 ㎍/hr/cm², and corresponding Kp values were 7.55, 5.46, and 4.16. Catechin's Kp value was consistently classified as "moderate" across all concentrations. The efficacy of quercetin, catechin, and naringenin, active ingredients in high-performance and anti-inflammatory Smilax china extracts, was found to exhibit skin penetration properties above the average. This confirms their suitability as excellent natural materials for use in functional cosmetics, given their outstanding capabilities in preventing acne and reducing inflammation.

• (The)Study of the Eastern Classic
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• no.49
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• pp.109-136
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• 2012

'Old man' or 'old age' was not the parts of academic discipline in the Joseon era but Yeoheon put it in the philosophical 'problematization' of the learning of the Confucianism. He was argued that the old man or old age is not merely biological decline but it has the goal to achieve. The completion of self is the meaning and end of the life throughout the subjective realization and procedure of attaining the goal step by step. Well-aged old man is affirming the getting old and making the positive changing of old life time in his one sake. This essay is showing the Yeoheon's thought of old aging as the self-realizing well-ageing. Next, it is argued that the predicament of old age or old man is not just social welfare or biological aspects but it is serious philosophical problems. If it was just social or biological aspects then it is just a social phenomenon to approach the view of scientists. However, this is not only life and death and flux of time and relativities but also it is problematizing the self-identification subjectivities. Obviously, it is the significant that the old and or old age is fundamentally philosophical subject rather than social or biological materials. In the third chapter, we are dealing with the views of the life and death of Yeoheon. He was insisted that quite interesting opinion that is the all the lives in the universe include himself is 'a wayfarer'. It looks like a time traveler in the universe; we are just one who stays in a body for awhile. When we follow him, we are living in this universe in a time (disposable) but the same theorem is applying to the whole universe as well myriad creatures. Therefore, man has a job to do as an entity of the universe. Yeoheon was called it is the business as a job and we have to do the Dao till you end. The fourth, Yeoheon was suggested that the old man has his work and business. There are two kind of works for an old man, the former is self control as an old age that is call the old man's job and the latter is staying with the Dao that is called the old man's business. According to Yeoheon, man has charged to realize the law of the universe that means we are the moral entity; therefore we are business to complete ourselves. Old age is decline of physical activities rather than vigorous, therefore, we have to follow our body and self-affirmation of declination is the Dao. The final, Yeoheon was advised that the old man better saved in the current of the Dao, because the physical function is declining but the shining Dao is within the mind in the body. It is motivation of the self-dignity of old man and one who recognizes the work to do even in the old body that he will be the significant among all the society not a lonely old man anymore. Old aging is biological twilight but the considerable real size expertise and self-affirmation is the Dao of old age. We are meditating nowadays in Yeoheon's philosophical context on old man or old aging. By him, the old age is man of dignity as long as he realizes in his Dao through the business and self-affirmation.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.1
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• pp.31-36
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• 2008

This work was performed to evaluate the effect of membrane material and structure on fouling in a submerged membrane bioreactor(MBR). Three types of microfiltration membranes with the same pore size of 0.1 $\mu$m but different materials, polytetrafluoroethylene (PTFE), polycarbonate(PCTE) and polyester(PETE), were used. While PETE membrane exhibited the most rapid flux decline throughout the operation, PCTE and PTFE had a similar tendency with regard to permeability. Difference in permeability between PETE and the other membranes gradually decreased with time, which was probably due to chemical cleaning. The higher TOC rejection of PETE membrane could be attributable to its faster fouling, resulting from a larger amount of foulants to get attached to the membrane in a shorter time. DOC fractionation using a DAX-8 resin showed that the composition of each fraction between the supernatant and permeates did not change significantly with operation time, indicating that membrane hydrophilicity/hydrophobicity was not a dominant factor affecting to MBR fouling in this study. Compared to other membranes, the fouling of PETE membrane was more influenced by pore clogging (irreversible fouling), which would probably contribute to a higher organic rejection of the PETE membrane.

• Journal of Haehwa Medicine
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• v.26 no.1
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• pp.33-48
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• 2017

Objective : Ten heavenly stems and twelve earthly branches are the important means to understand the orders of changes in heaven and earth. Method : We have so far looked into detailed explanations about twelve earthly branches in Seolmunhaeja, annotations in Seolmun of four major people, and commentaries in Jeongyeokwonui. Result & Conclusion : This can be also applied to the explanations of twelve early branches, as follows. In the $11^{th}$ month of the lunar calendar, the yang energy is finally born amid full of the ying energy. In the $12^{th}$ month, the yang energy prepares to break through the knots of the ying energy and gets ready to come out of the ground. In the first month, three kinds of the yang energy start to become vigorous and active. In the second month, the yang energy gains more force, sprouting various plants on the ground. In the third month, the yang energy arouse further, strengthening and growing plants. In the fourth month, all the yang energy is released, while the ying energy is still hiding. In the fifth month, one ying energy is born amid full of the yang energy, and there are interchanges between the yang energy and the ying energy. In the sixth month, the yang energy is still strong and vigorous, ripening the fruits in the fields. In the seventh month, the yang energy starts to hurt all creation. In the eighth month, the ying energy starts to flourish, and the yang energy starts to decline, diminishing all creation and, however, still ripening grains to be harvested. In the ninth month, one yang energy starts to hide from sight, not working its duty, while five kinds of the ying energy start to annihilate all creation. Finally, in the tenth month, the small yang energy hides to be rebirthed amid the flux and reflux of the ying-yang energy. The creative and unique interpretation of Jeongyeokwonui about twelve earthly branches is worth to be referred. It is definitely beyond the other existing explanations, as it incorporates trigrams and hexagrams from I Ching (Book of Changes) and the five primary substances.

• Journal of Navigation and Port Research
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• v.39 no.6
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• pp.485-491
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• 2015

The technology review about risk of hypothermia of victim according to heat transfer characteristic of life raft and sea state can use accident correspondence of standing and sinking of ship. This study studied heat transfer characteristics required for the design of life raft and thermal insulation property analysis and evaluation methods. In addition, it is study for comprehend the risk of hypothermia and suggest analysis result that is experiment of thermal insulation property and body temperature property for decide of prediction the body temperature decline Thermal Analysis apply the finite element analysis method is comprehended the property of heat conductivity, convective effect of sea water and properties changes according to property of insulation material. it measure the heat flux with attach temperature sensor on body in order to comprehend the variation of body temperature with boarding a life raft experiment on a human body. This study validate results by comparing variation of temperature measured from experiment on a body with variation of temperature from finite element analysis model. Also, the criteria of hypothermia was discussed through result of finite element analysis.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.1
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• pp.51-57
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• 2009

Biofouling in seawater reverse osmosis (SWRO) desalination process causes many problems such as flux decline, biodegradation of membrane, increased cleaning time, and increased energy consumption and operational cost. Therefore biofouling is considered as the most critical problem in system operation. To control biofouling in early stage, detection of the most problematic bacteria causing biofouling is required. In this study, six model bacteria were chosen; Bacillus sp., Flavobacterium sp., Mycobacterium sp., Pseudomonas aeruginosa, Pseudomonas fluorescens, and Rhodobacter sp. based on report in the literature and phylogenetic analysis of seawater intake and fouled RO membrane. The adhesion to RO membrane, the high pressure resistance, and the hydrophobicity of the six model bacteria were examined to find out their fouling potential. Rhodobacter sp. and Mycobacterium sp. were found to attach very well to RO membrane surface compared to others used in this study. The test of hydrophobicity revealed that the bacteria which have high hydrophobicity or similar contact angle with RO membrane ($63^{\circ}$ of contact angle) easily attached to RO membrane surface. P. aeruginosa which is highly hydrophilic ($23.07^{\circ}$ of contact angle) showed the least adhesion characteristic among six model bacteria. After applying a pressure of 800 psi to the sample, Rhodobacter sp. was found to show the highest reduction rate; with 59-73% of the cells removed from the membrane under pressure. P. fluorescens on the other hand analyzed as the most pressure resistant bacteria among six model bacteria. The difference between reduction rates using direct counting and plate counting indicates that the viability of each model bacteria was affected significantly from the high pressure. Most cells subjected to high pressure were unable to form colonies even thought they maintained their structural integrity.