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        검색결과 86

        2.
        2024.01 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, a low-cost and easily recyclable porous green adsorbent (magnetic porous loofah biochar, MPLB) was synthesized by modifying the almost zero-cost loofah biochar material with Fe3O4. The successful synthesis of the material was demonstrated by XRD, FTIR, SEM, VSM, and BET. In addition, the material exhibits outstanding magnetic separation performance (40.01 umg/g) allowing for rapid recovery within just 90 s. The adsorption process of phenol on MPLB was found to be spontaneous and endothermic. The experimental data fit exceptionally well with the pseudo-second-order kinetic model and Langmuir model (R2 > 0.99), indicating that the dominant adsorption mechanisms involved monolayer adsorption and chemisorption. These interactions were attributed to host–guest interaction, π–π conjugation, hydrogen bonding, and pore filling. The maximum adsorption capacity calculated using the Langmuir model at 298 K is 39.4 mg/g. Importantly, even after undergoing seven cycles of recycling, MPLB retained 78% of its initial adsorption capacity. In simulated experiments employing MPLB for phenol removal in actual wastewater, an impressive removal rate of 96.4% was achieved. In conclusion, MPLB exhibits significant potential as an effective adsorbent for phenol removal in wastewater.
        4,000원
        3.
        2023.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study aimed to investigate the growth and phenol content changes of basil (Ocimum basilicum L.) under five different light intensities and photoperiods, maintaining the same Daily Light Integral (DLI) conditions in a plant factory. Basil seeds were sown on a rockwool medium for four weeks and then transplanted. To maintain a DLI 17mol·m-2·d-1, light intensity and photoperiod were set at 16h-295, 18h-260, 20h-235, 22h-215, and 24h-200μ mol·m-2·s-1 and cultivated for four weeks. The harvested results showed that basil plant height, number of lateral branches, and leaf number tended to decrease from the 16h-295 treatment to the 24h-200 treatment. Shoot fresh weight, dry weight, leaf area, leaf width, and leaf length were significantly higher in the 18 h-260 treatment. The total phenolic contents in the 18h-260 treatment was significantly higher by 51.3%, 172.7%, 111%, and 119.7% compared to the 16h-295, 20h-235, 22h-215, and 24h-200 treatments, respectively. Therefore, it is anticipated that cultivating basil under the condition of 18h-260 treatment could yield enhanced growth quality and an increase in total phenolic contents.
        4,000원
        4.
        2023.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study investigated durian (Durio zibethinus) peels to produce powdered activated carbon (DPAC). The influence of process variables such as carbonization temperature, activation time, contact time, CO2 flow rate, and adsorption dosage was optimized using response surface methodology (RSM). A six-factor and two levels Box–Behnken design (BBD) was used to optimize the parameters. The independent variables were activation temperature (°C), duration (min), CO2 flow rate during the activation process (L/min), irradiation of adsorbent (kGy), irradiation duration (min), and adsorbent dosage (g) while phenol removal (mg/L) was the dependent variable (response). Following the observed correlation coefficient values, the design was fitted to a quadratic model (R2 = 0.9896). The optimal removal efficiency (97.25%) was observed at an activation temperature of 900 °C, activation time of 30 min, CO2 flow rate of 0.05 L/min, irradiation dose of 100 kGy, contact time of 35 min and adsorption dosage of 0.75 g. The optimal DPAC showed a BET surface of 281.33 m2/ g. The removal efficiency was later compared with a commercially available activated carbon which shows a 98.56% phenol removal. The results show that the durian peel could be an effective precursor for making activated carbon for phenol removal, and irradiation can significantly enhance surface activation.
        4,000원
        5.
        2021.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The paper deals with a comparative study of equilibrium and kinetics of phenol adsorption from aqueous solutions by means of commercial activated carbons and semi-cokes, differing in the nature of feedstock, production technology and structural characteristics. The main adsorption parameters are calculated with the usage of Langmuir and Dubinin–Radushkevich equations. The change in the characteristics of the structure and state of the surface of semi-coke P2 as a result of modification is estimated. It was found that phenol adsorption kinetics is described by a pseudo-second-order model. The adsorption rate constants and the coefficient of external diffusion mass transfer are calculated. It is proved that phenol extraction from aqueous solutions presents a mixed-diffusion nature, and the process rate is limited by external mass transfer for 13 min for SKD-515 and 22 min for ABG. To increase the adsorption capacity, the oxidative modification of the semi-coke P2 was carried out. Considering the economic and technological aspects, ABG semi-coke is recognized as a promising sorbent for phenol extraction from aqueous media.
        4,000원
        6.
        2020.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study investigated the degradation characteristics and biodegradability of phenol, refractory organic matters, by injecting MgO and CaO-known to be catalyst materials for the ozonation process-into a Dielectric Barrier Discharge (DBD) plasma. MgO and CaO were injected at 0, 0.5, 1.0, and 2 g/L, and the pH was not adjusted separately to examine the optimal injection amounts of MgO and CaO. When MgO and CaO were injected, the phenol decomposition rate was increased, and the reaction time was found to decrease by 2.1 to 2.6 times. In addition, during CaO injection, intermediate products combined with Ca2+ to cause precipitation, which increased the COD (chemical oxygen demand) removal rate by approximately 2.4 times. The biodegradability of plasma treated water increased with increase in the phenol decomposition rate and increased as the amount of the generated intermediate products increased. The biodegradability was the highest in the plasma reaction with MgO injection as compared to when the DBD plasma pH was adjusted. Thus, it was found that a DBD plasma can degrade non-biodegradable phenols and increase biodegradability.
        4,000원
        7.
        2019.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This objective of this study was to investigate the degradation characteristics of phenol, a refractory substance, by using a submerged dielectric barrier discharge (DBD) plasma reactor. To indirectly determine the concentration of active species produced in the DBD plasma, the dissolved ozone was measured. To investigate the phenol degradation characteristics, the phenol and chemical oxygen demand (COD) concentrations were evaluated based on pH and the discharge power. The dissolved ozone was measured based on the air flow rate and power discharged. The highest dissolved ozone concentration was recorded when the injected air flow rate was 5 L/min. At a discharge power of 40W as compared to 70W, the dissolved ozone was approximately 2.7 – 6.5 times higher. In regards to phenol degradation, the final degradation rate was highest at about 74.06%, when the initial pH was 10. At a discharged power of 40W, the rate of phenol decomposition was observed to be approximately 1.25 times higher compared to when the discharged power was 70W. It was established that the phenol degradation reaction was a primary reaction, and when the discharge power was 40W as opposed to 70W, the reaction rate constant(k) was approximately 1.72 times higher.
        4,000원
        8.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        약용매에 용해가 가능한 알킬기 변성 에폭시수지를 합성하기 위하여, 1단계에서 당량비 기준 dodecyl phenol (DP)/formaldehyde = 1.25~1.333/1.0로 하여, 합성된 도데실 페놀 노볼락 화합물의 벤젠 고리수가 3.0~5.0가 되도록 합성하였고, 2단계에서는 당량비 기준으로 1단계에서 합성된 도데실 페놀 노 볼락 화합물/비스페놀A형 에폭시수지 (YD-128) = 1/2로 합성하였고, 3단계는 지방산을 투입하여 지방산 변성 도데실 페놀 노볼락 에폭시수지를 합성하였다. 합성된 수지의 반응성도, 점성도와 분자량 변화, 약용 매 가용성 등을 측정한 결과, 1단계에서 합성된 도데실 페놀 노볼락 화합물의 벤젠고리수가 늘어남에 따라 지방산 변성 도데실 페놀 노볼락 에폭시수지의 점도가 상승하였고, 약용매 가용성이 우수하였다. 도료 제 조 후 물성을 측정한 결과, 개환촉매로 triphenylphosphine(TPP)을 사용한 DPFAC-5는 건조속도, 접착성, 도막경도, 내충격성, 내산성 및 저장안정성이 양호하였다.
        4,300원
        9.
        2016.09 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Microstructure evolutions of thermosetting resin coating layers fabricated by electrostatic spray deposition (ESD) at various processing conditions were investigated. Two different typical polymer systems, a thermosetting phenol-formaldehyde resin and a thermoplastic polyvinylpyrrolidone (PVP), were employed for a comparative study. Precursor solutions of the phenol-formaldehyde resin and of the PVP were electro-sprayed on heated silicon substrates. Fundamental differences in the thermomechanical properties of the polymers resulted in distinct ways of microstructure evolution of the electro-sprayed polymer films. For the thermosetting polymer, phenol-formaldehyde resin, vertically aligned micro-rod structures developed when it was deposited by ESD under controlled processing conditions. Through extensive microstructure and thermal analyses, it was found that the vertically aligned micro-rod structures of phenol-formaldehyde resin were formed as a result of the rheological behavior of the thermosetting phenol-formaldehyde resin and the preferential landing phenomenon of the ESD method.
        4,000원
        10.
        2015.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Total phenol contents, total flavonoid contents and antioxidant activity of 70% methanol, 70% ethanol and chloroform-methanol (CM, 2:1, v/v) extracts from onion (Allium cepa L.) peels were studied. The IC50 values of DPPH (2,2-diphenyl-1-picrylhydrazyl) radical and ABTS [2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt] radical scavenging activity in 70% ethanol extract were remained to be lowest followed by 70% methanol extract and CM extract. And the total phenol content (113.56±0.86 mg CAE/g), total flavonoid content (49.63 mg QE/g) and ferric reducing antioxidant power value were also found to be the highest. In contrast, 70% methanol extract possessed the strongest antioxidant activity by β-carotene bleaching assay. CM extract displayed the lowest antioxidant activity compared with other extracts. Onion peels exhibited strong antioxidant activity and abundant phytochemicals, which could be used in a various food products to add phytochemicals and promote good health.
        4,000원
        11.
        2014.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        페놀은 보통 대기로 배출되며 반감기가 비교적 짧은 물질로서 환경에 농축되는 경우는 드물다. 하지만, 누출사고가 발생되어 수계나 토양에 오염될 경우 페놀에 오염된 농수산물의 안전성을 확보하기 위하여 페놀을 정확하게 검출할 수 있는 시험법을 확립하고자 하였다. 식품 중 페 놀을 초음파추출기로 추출하고 GPC로 정제하여 GC/MS 로 분석하는 시험법을 확립하였으며, 시험법의 유효성 확인을 위한 실험 결과들이 AOAC 가이드라인에서 제시하 는 Criteria를 만족함으로써 시험법의 신뢰성을 확보할 수 있었다. 확립된 시험법은 식품 중 페놀의 오염조사 및 이행률 조사에 활용될 수 있다.
        3,000원
        12.
        2014.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        멜라민수지 조리기구 제조에 사용되는 formaldehyde와 phenol의 경우 식품에 이행될 우려가 있다. 이에 본 연구에서는 국내에서 유통되고 있는 멜라민수지 조리기구 222 건에 대하여 formaldehyde와 phenol의 식품유사용매로의 이행량을 조사하였다. 멜라민수지 조리기구는 컵(14), 공기(75), 접시(85), 숟가락(10), 젓가락(4), 식판(8), 주걱(4), 뒤지게(9) 및 국자(12)등을 수거하였다. 식품유사용매로는 물, 4% 초산, 20% 에탄올, n-헵탄을 사용하였다. 한국의 멜라민수지 기구 및 용기·포장 중 formaldehyde와 phenol의 용출기준은 각각 4 mg/L, 5 mg/L 이며, 수거된 222건 멜라 민수지 조리기구 모두 기준·규격에 적합하였다. 멜라민 수지 조리기구 중 formaldehyde와 phenol의 이행량은 각각 N.D~2,949 μg/L, N.D~78 μg/L이었다. 위 분석결과는 멜라민수지 기구 및 용기·포장의 안전관리의 과학적 근거 자료로 제공될 수 있을 것으로 판단된다.
        4,000원
        13.
        2014.07 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A hierarchical pore structured novolac-type phenol based-activated carbon with micropores and mesopores was fabricated. Physical activation using a sacrificialsilicon dioxide (SiO2) template and chemical activation using potassium hydroxide (KOH) were employed to pre-pare these materials. The morphology of the well-developed pore structure was character-ized using field-emissionscanning electron microscopy. The novolac-type phenol-based activated carbon retained hierarchical pores (micropores and mesopores); it exhibited high Brunauer-Emmett-Teller specificsurface areas and hierarchical pore size distributions. The hierarchical pore novolac-type phenol-based activated carbon was used as an electrode in electric double-layer capacitors, and the specificcapacitance and the retained capacitance ratio were measured. The specificcapacitances and the retained capacitance ratio were en-hanced, depending on the SiO2 concentration in the material. This result is attributed to the hierarchical pore structure of the novolac-type phenol-based activated carbon.
        4,000원
        14.
        2014.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Formaldehyde and phenol used in the production of melamine-wares may be intended to come into foodstuffs. So this study investigated the migration of formaldehyde and phenol from 222 articles Articles were cups(14), bowls(75), plates(85), spoons(10), chopsticks(4), food trays(8), rice paddles(4), spatulas(9) and scoops(12). The food stimulants were 4% acetic acid, 20% ethanol, distilled water and n-heptane. Korea regulation (Standards and specifications for food utensils, containers and package) specifies migration limits for formaldehyde and phenol in food stimulants. Formaldehyde and phenol are restricted by 4 mg/L, 5 mg/L respectively. In all cases the migration of formaldehyde and phenol were below the limit set in Korea regulation. The level of formaldehyde and phenol migrated to food simulants were in the range of N.D~2.949 mg/L, N.D~0.078 mg/L respectively. These migration results of formaldehyde and phenol will provide a scientific basis for the safety management of melamine-wares.
        4,000원
        15.
        2013.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        재래유자, 개량종 I(유자+탱자), 개량종 II(유자+유자) 세가 지 유자의 종류별, 부위별 이화학적인 특성과 유기산, 지방산 및 향기성분을 분석하였고, 총 페놀 화합물을 분석하는 실험 을 수행하였다. 중량은 재래종이, 껍질(혹은 껍질+씨)의 비율 은 개량종이 높았다. 단백질은 재래종보다 개량종Ⅰ의 껍질 에서 다소 높게 나타났고, 회분도 개량종의 껍질에서 다소 높 았다. Vit. C는 과즙의 경우 재래종에서 29.6 ㎎%로 껍질에서 는 개량종 I이 57.7 ㎎%로 다소 높았다. 유리당은 과당이 주 였는데, 개량종 I에서 가장 높은 함량을, 유기산은 구연산이 대부분을 차지하였는데, 개량종 II에서 가장 유기산 함량이 높았다. 유자의 지방산 조성은 리놀레인산이 가장 많았고, 과 피와 과즙에서 품종별 특징을 보이고 있었다. 향기성분은 dl-Limonene이 향기성분의 64~70%를 차지하는 물질로, gammaterpinene과 함께 개량종 II에서 유의하게 높았다. 유자에 함 유된 총 페놀 함량은 품종별로는 유의한 차이를 보이지 않았 으나, 과즙에 비해 과피에 2.5배 정도 많은 양이 들어 있었다.
        4,000원
        16.
        2012.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Herein, macroporous carbon foams were successfully prepared with phenol and formaldehyde as carbon precursors and an ionic liquid, 1-butyl-3-methylimidazolium hexafluorophosphate (BMIPF6), as a pore generator by employing a polymerization-induced phase separation method. During the polycondensation reaction of phenol and formaldehyde, BMIPF6 forms a clustered structure which in turn yields macropores upon carbonization. The morphology, pore structure, electrical conductivity of carbon foams were investigated in terms of the amount of the ionic liquid. The as-prepared macroporous carbon foams had around 100-150 μm-sized pores. More importantly, the electrical conductivity of the carbon foams was linearly improved by the addition of BMIPF6. To the best of the author's knowledge, this is the first result reporting the possibility of the use of an ionic liquid to prepare porous carbon materials.
        4,000원
        17.
        2011.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A voltammetric assay of phenol ions was investigated using three electrode systems of graphite pencil working, reference and counter electrodes. Under optimum analytical parameters, square wave stripping working ranges were attained at a mili range of 10~80 mg/L and a micro range of 20~90 ug/L using seawater electrolyte. The developed sensor was applied to tap water and the human body system of a smoker. It was found that the methods can be applied to in vivo fluid or medicinal diagnosis.
        4,000원
        18.
        2011.06 KCI 등재후보 구독 인증기관 무료, 개인회원 유료
        Objectives : The purpose of this study is to identify the characteristics that affect the urinary phenol of workers exposed to phenol.
        Subjects and Methods : Total 41 workers were selected at bisphenol A manufacturing plant and their urinary phenol concentration were measured before and after work along with the phenol concentration in the workplace air, and carried out a survey on work characteristics and lifestyle factors that could affect urinary phenol.
        Results : The phenol concentration in air during work hours was 0.91 (non-detection~2.88) mg/m3, and the worker’s urinary phenol concentrations before and after work were 100.27±75.76 and 138.13±109. 58 mg/g creatinine, respectively, which showed a statistically significant increase. Comparing smoking and urinary phenol concentration, smokers had 194.54±137.52 mg/g creatinine while non-smokers had 108.88±80.10 mg/g creatinine, thus showing the urinary phenol concentration of smokers to be statistically significantly higher (p=0.046). The urinary phenol concentration increased as work hours, the frequency of skin exposure to phenol, and the amount of drinking increased, and there were differences in its concentration depending on the work type and whether or not workers wore protective gear. The results of carrying out a multiple regression analysis showed that phenol concentration in air, work hours, frequency of skin exposure, and smoking were statistically significant. In other words, the urinal phenol concentration increased more for smokers than for non-smokers, when work hours became longer, and when the frequency of skin exposure was over five times.
        Conclusions : The factors that influenced urinary phenol in workers exposed to phenol were phenol concentration in air, work hour, frequency of skin exposure, smoking, work and lifestyle habits. Accordingly, biological monitoring for phenol exposure assessment must reflect these factors, and effort must be made to reduce skin exposure at workplace.
        4,300원
        19.
        2011.06 구독 인증기관 무료, 개인회원 유료
        페놀류는 석유정제, 섬유산업, 도로포장 및 광산산업 등의 폐수에 다량 함유되어있는 내분비계교란 및 독성 물질로서 연안해역으로 유입 시 해양 서식 생물의 생식세포 및 배아 발생 등에 영향을 미치 는 것으로 알려져 있다. 성게는 수정 및 배아 발생과 같은 초기생활사 연구에 중요한 생물 종으로서 유해물질 위해성 평가에 유용하게 이용되고 있다. 본 연구는 우리나라 조간대 암반 지역에 주로 서식 하는 말똥성게 (Hemicentrotus pulcherrimus)를 이용하여 페놀이 말똥성게 (H. pulcherrimus)의 생식 세포 및 배아 발생에 어떤 영향을 미치는지에 대하여 관찰하였다. 성숙한 말똥성게 (H. pulcherrimus) 에 0.5 M KCl를 주입하여 방란 및 방정을 유도한 후, 수집한 정자 및 난자를 페놀 농도 (10, 100, 500, 1000, 5000, 10000 ppb)에서 10분간 인공수정 한 후, 수정 및 배아발생을 관찰하였다. 수정률 은 페놀 농도에 유의적인 영향을 받지 않았으나 배아 발생은 페놀 농도가 높을수록 정상적으로 발생 하는 개체가 감소하는 농도 의존성을 나타냈다. Metallothionein mRNA 유전자는 페놀 농도가 증가할 수록 발현이 높게 나타났으며 Nodal mRNA 유전자는 유의적인 차이가 나타나지 않았다. 말똥성게 (H. pulcherrimus) 배아 발생에 미치는 페놀의 영향을 독성치로 나타낼 때, 무영향농도 (NOEC)는 10 ppb, 최소영향농도 (LOEC)는 100 ppb를 나타냈으며 반수영향농도 (EC50)는 1565.86 ppb를 나타내 었다. 본 연구 결과로서, 연안 해역에 유입되는 페놀이 무영향농도 (NOEC) 10 ppb를 초과할 경우, 성게를 비롯한 조간대 암반에 서식하는 생물종의 생식 및 발생에 유해한 영향을 미칠 것으로 판단된 다.
        3,000원
        20.
        2010.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        탄소막은 고분자막에 비해 높은 선택성과 투과성, 열적, 화학적 안정성을 가지고 있어 기체 분리, 특히 휘발성 유기화합물(VOCs) 분리막으로 많은 관심을 받고 있다. 활성탄소중공사막은 기공 표면(pore wall)에 형성된 흡착성 미세기공에 의해 선택적으로 응축성 성분이 흡착, 확산되는 흡착-확산 기구에 의해 흡착성-비흡착성 물질이 분리된다. 본 연구에서는 다공성 알루미나 중공사막 지지체에 phenolic resin (novolac type)을 코팅한 후 산화, 탄화 및 활성화 등의 열분해 과정을 통해 막 표면과 기공 표변에 흡착성 미세기공이 형성된 활성탄소중공사막을 제조하였다. 또한 열분해 조건에 따른 phenol/alumina 복합 활성탄소중공사막의 물리적 특성과 기체 투과특성에 대해 살펴보았다. 그 결과, 제조된 phenol/alumina 복합 활성탄소중공사막이 휘발성 유기물질의 대부분을 차지하고 있는 탄화수소를 선택적으로 분리 회수하는데 매우 효과적인 특성을 갖고 있음을 확인할 수 있었다. 따라서 본 연구에서 개발된 phenol/alumina 복합 활성탄소중공 사막은 VOCs의 분리, 농축에 매우 효과적으로 활용 가능할 것으로 기대된다.
        4,000원
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