• Title/Summary/Keyword: Science and Technology Park

Search Result 24,729, Processing Time 0.065 seconds

Optimal Extract Condition for the Enhancement of Anticancer Activities of Artemisia princeps Pampanini (강화 사자발쑥의 항암활성 증진을 위한 추출조건의 최적화)

  • Kwon, Min-Chul;Kim, Cheol-Hee;Kim, Hyou-Sung;Lee, Sang-Hee;Chio, Geun-Pyo;Park, Uk-Yeon;You, Sang-Guan;Lee, Hyeon-Young
    • Korean Journal of Medicinal Crop Science
    • /
    • v.15 no.4
    • /
    • pp.233-240
    • /
    • 2007
  • Extractions of Artemisia princeps Pampanini were obtained by using water and ethanol at different temperatures ($60^{\circ}C,\;100^{\circ}C$) with or without ultrasonification process (40 kHz). Yield of ultrasonificated extracts were about 20% higher than that of control group. Cytotoxicity of all conditions through adding 1.0 mg/$m{\ell}$ was below 37%, and treated with ultrasonification group was lower than the other group, about $5{\sim}8%$. $100^{\circ}C$ water extract with ultrasonification was higher anticancer activities as maximum 73% and higher selectivities at concentrations over 0.8 mg/$m{\ell}$. The extracts treated with ultrasonification were higher anticancer activities than the control. Densitometric analysis of bcl-2 revealed that extracts of high anticancer activity had low density. This results suggest that expression of bcl-2 protein by adding of Artemisia princeps Pampanini extracts relative to taking cancer. To conclude, optimum condition for efficient extraction of Artemisia princeps Pampanini is using water with ultrasonification at over $60^{\circ}C$ below $100^{\circ}C$.

The Biological Activity from Prunella vulgaris Extracts (하고초(Prunella vulgaris) 추출물의 생리활성)

  • Kim, Jin-Sung;Lee, Ju-Yeong;Park, Ki-Tae;An, Bong-Jeun;Lee, Sun-Ho;Cho, Young-Je
    • Food Science and Preservation
    • /
    • v.20 no.2
    • /
    • pp.234-241
    • /
    • 2013
  • The phenolic compounds of water extracts from Prunella vulgaris were highest at 9.25 mg/g, respectively, when various extraction solvents were used. The optimum condition for extracting phenolic compounds from Prunella vulgaris was extraction in water for 18hr. The DPPH-scavenging activities of Prunella vulgaris were highest at the water extracts. The ABTS radical cation decolorization was higher than 40% in the range of 0~100% ethanol extract section. The antioxidant protection factor on the lipophilic phenolic metabolites was shown to be 1.1 PF in the water extracts from Prunella vulgaris. The TBARS was lower than the control ($0.53{\mu}M$) in all the sections. The tyrosinase inhibitory effect, which is related to skin whitening, was above 40%, and for the anti-wrinkle effect, the elastase inhibition activity was above 40% at 0.2 mg/mL. The astringent effect of the Prunella vulgaris 40% ethanol extracts was 98.1% at 1 mg/mL. As a result, it can be concluded that Prunella vulgaris has the potential to be used as a cosmetic material.

Analysis of High School Students' Understanding of Acid-Base Related Concepts Using Three Different Neutralization Titration Technologies (세 가지 다른 중화적정 실험 방법에 따른 고등학생들의 산.염기 관련 개념의 이해 분석)

  • Ree, Jong-Baik;Park, Ga-Young;Lee, Sang-Kwon
    • Journal of The Korean Association For Science Education
    • /
    • v.31 no.6
    • /
    • pp.864-875
    • /
    • 2011
  • The purpose of this study was to investigate high school students' understanding of acid-base related concepts using three different titration technologies. The test population was composed of 209 students from three classes in the 10th grade. The different titration experiments using indicator, or pH-meter or MBL were performed in each class unit, respectively. The analyses of the effect on the understanding of different titration technologies were carried out by comparing the mean scores of the concept test taken before and after the titration for the three groups. The results of the acid-base related concept test indicated that statistically significant effects on the understanding of the concepts were shown by all groups. Comparing the effect on the comprehension of the three groups, the MBL group showed the most significant effect, while the pH-meter group showed the least significant. It was also attempted to analyze the effect on comprehension of the concepts by the cognitive and the motivational levels of students. This study revealed that the students in the formal operation stage showed higher understanding of the acidbase related concepts, while those in the concrete operation stage showed lower comprehension. It was also shown that the students at the active motivational level scored higher in comprehension than those who had a low score. The results of this study implied that each group showed differently enhanced comprehension of concepts by titration technologies. Therefore, teachers need to promote an appropriate experiment technology for the cognitive and motivational levels of students as well as try to help students express freely their own perspectives.

The Structural Characteristics of the Active Ingredients in Several 'Hot and Warm' Herbal Medicine (한약(韓藥)의 온열성약(溫熱性藥)의 성분(成分)과 화학적(化學的) 특성(特性)에 관(關)한 연구(硏究))

  • Shin, Joon-Shik;Ahn, Duk-Kyun;Park, Ho-Koon
    • The Journal of Korean Medicine
    • /
    • v.20 no.1 s.37
    • /
    • pp.1-10
    • /
    • 1999
  • 한약(韓藥)의 효능(效能)은 약성(藥性)에 의해 분류(分類)되고 질병(疾病)을 치료(治療)하며 예방(豫防)하는 작용(作用)을 한다. 그러나 약성(藥性) 이론(理論)의 문헌(文獻)과 임상연구(臨床硏究)는 비교적 많지만 상대적으로 실험연구(實驗硏究)는 일부분에 불과하여 효능(效能)을 입증(立證)하는데 어려움이 많다. 이에 저자(著者)는 온열성약(溫熱性藥)들이 지니고 있는 유효(有效) 성분(成分)들을 조사(調査)하고 이 온열성약(溫熱性藥)에 함유(含有)되어 있는 유효(有效) 성분(成分)들의 구조적(構造的)인 특성(特性)과 화학적(化學的)인 공통점(共通點)을 찾아 온열성약(溫熱性藥)의 분류(分類)에 대한 일반적(一般的)인 기준(基準)을 제시(提示)하고자 하였다. 그 결과 각각의 열성약(熱性藥)과 온성약(溫性藥)들이 함유(含有)하고 있는 유효(有效) 성분(成分)간의 구조적(構造的)인 공통점(共通點)을 찾아내었으며 구조적(構造的)인 공통점(共通點)으로부터 다음과 같은 결론(結論)을 얻었다. 1. 열성약(熱性藥) 중에서 강(强)한 독성(毒性)을 나타내는 부자(附子)와 초오(草烏)의 효능을 나타내는 유효 성분(成分)들은 C19-diterpenoid alkaloid과 C20-diterpenoid alkaloid 계열의 구조(構造)를 지닌 화합물들로 구성(構成)되어 있다. 이 디테르펜 알카로이드(diterpene alkaloid)들의 경우 고리의 구조(構造)가 aconitane(1), hetisan(16)과 7,20-cycloveatchane(17)의 기본골격(基本骨格)을 지니고 있으며, 이 두 가지 기본구조(基本構造)의 공통점(共通點)은 A 고리에 질소를 포함한 2-azabicyclo-[3.3.1]-nonanyl의 부분구조를 갖고 있으며, 이 부분 구조는 자연계에 존재하는 tropane alkaloid들의 기본구조(基本構造)와 유사하다. Tropane alkaloid들은 중추신경계에 작용하는 약물들로 알려져 있으며, tropane alkaloid는 일반적으로 anatoxin a(171)와 같이 강(强)한 독성(毒性)을 나타내며, 부자(附子)와 초오(草烏)가 지니고 있는 강한 독성(毒性)은 바로 2-azabicyclo-[3.3.1]-nonanyl 구조(構造)에 기인하는 것으로 추정할 수 있다. 2. 육계(肉桂)에 주성분으로 함유(含有)되어 있는 cinncassiol(47) 화합물(化合物)들은 분자 내에 bicyclo-[4.3.0]-nonanyl과 bicyclo-[3.3.0]-octanyl의 기본 혹은 부분 구조를 지니고 있다. 3. Cinncassiol(47) 화합물(化合物)들은 강(强)한 항균력(抗菌力)을 보이고 있는데, cinncassiol(47) 화합물들이 지니고 있는 구조적인 특성인 bicyclo-[4.3.0]-nonanyl과 bicyclo-[3.3.0]-octanyl의 기본 혹은 부분 고리구조는 sesquiterpenoid 화합물(化合物)들과 diterpenoid 화합물(化合物)들 중에서 많이 발견되며, 이러한 구조(構造)를 지니고 있는 sesquiterpenoid 화합물(化合物)과 diterpenoid 화합물(化合物)들도 좋은 항균력(抗菌力)을 보이고 있다. 이러한 공통(共通)된 구조상(構造上)의 유사점(類似點)이 항균력(抗菌力)을 나타내는 지표로서 활용 가능성이 기대된다. 4. 온성약(溫性藥)의 경우, 백지(白芷)의 coumarin(39) 화합물(化合物)들과 furocoumarin(61) 화합물(化合物)들, 건량(乾量)의 gingerol(87), shogaol(93), gingerdiol(95) 등과 capsaicin(102), 마황(麻黃)의 ephedrine(124) 계렬(系列) 화합물(化合物)들, 세신(細辛)의 methyleugenol(136)과 asaricin(137)의 구조(構造)에서 발견(發見)할 수 있는 공통적(共通的)인 요소는 phenolic 또는 methoxyphenyl의 공통구조를 지니고 있다. 온성약(溫性藥)의 유효성분들은 공통적으로 phenolic aromatic 화합물(化合物)을 함유(含有)하고 있다. 따라서, 열성약(熱性藥)과 온성약(溫性藥)은 주성분(主成分)들의 분포(分布)가 각기 다르며, 독성(毒性)을 나타내는 열성약(熱性藥)은 2-azabicyclo-[3.3.1]-nonanyl 구조(構造)를 지니고 있고, 육계(肉桂)와 같은 항균력(抗菌力)을 지니는 약물(藥物)은 bicyclo-[3.3.0]-octanyl 또는 bicyclo-[4.3.0]-nonanyl의 구조(構造)를 지닌다. 백지(白芷), 마황(麻黃), 세신(細辛) 등에서 볼 수 있듯이 온성약(溫性藥)은 benzene 구조(構造)를 함유(含有)하는 phenolic aromatic 화합물(化合物)들이 주종을 이룬다.

  • PDF

Studies on the Viability of In Vitro-Matured Bovine Oocytes Vitrified by Microdrop and Straw Method (Microdrop과 Straw 방법으로 초자화 동결한 소 난자의 생존율에 관한 연구)

  • Yang, B.C.;Yang, B.S.;Sung, H.H.;Im, S.K.;Park, S.B.;Chang, W.K.;Lee, C.K.
    • Journal of Animal Science and Technology
    • /
    • v.44 no.6
    • /
    • pp.701-710
    • /
    • 2002
  • Studies on the Viability of In Vitro-Matured Bovine Oocytes Vitrified by Microdrop and Straw Method To establish vitrification method for bovine oocytes, mature bovine oocytes were vitrified by microdrop (MD) or straw (Straw) method and the viability of vitrified oocytes with or without cumulus cells (CC) were examined by several methods; a) parthenogenetic activation; b) pronuclear formation after in vitro fertilization (IVF); and c) embryonic development after IVF. The survival rate of vitrified oocytes by MD was significantly higher than by Straw (92.50 vs. 74.19%, p<0.05). Most of the oocytes survived from vitrification using the MD methods. Cleavage and blastocyst development of parthenogenetically activated oocytes were higher in MD (45.05% and 10.81%, respectively; p<0.05)) than those in Straw method (27.17% and 6.52%, respectively; p<0.05). Male and female pronuclear formation of vitrified-thawed oocytes with or without cumulus cells (CC) after IVF were examined, respectively. The survival rate of vitrified oocytes by MD without CC was no difference between MD and Straw (80.368.14% vs. 67.31%). Normal fertilization (2PN) rates were not different among groups (Fresh; 54.55% vs. MD; 42.22% vs. Straw; 37.14%, p>0.05). While no fertilization (<1PN) rates were significantly different between fresh and vitrified-thawed groups (Fresh; 32.47% vs. MD; 57.78% and Straw 62.86%, p<0.05). The polyspermy (3PN) was appeared in the fresh (12.99%), but no appeared in the vitrified-thawed groups. In the without CC, normal fertilization (2PN) rates were significantly different between fresh and vitrified-thawed oocytes (Fresh; 59.38% vs. MD; 17.31% and Straw; 30.43%, p<0.05). Moreover, no fertilization (<1PN) rates were significantly different between fresh and vitrified-thawed groups (Fresh; 23.44% vs. MD; 73.08% and Straw 58.70%, p<0.05). The polyspermy (3PN, >4PN) was appeared not only fresh but vitrified-thawed groups. After IVF, two-cell developmental rates of vitrified oocytes with CC by MD and Straw were significantly low compared to fresh oocytes (Fresh; 81.76% vs. MD; 22.22% and Straw; 11.36%, p<0.05). Blastocyst developmental rates of vitrified oocytes also were significantly low compared to fresh oocytes (Fresh; 28.38 vs. MD; 1.71% and Straw 0%, p<0.05). In the without CC, two-cell developmental rates were no difference between Fresh and MD (27.59% vs. 19.25%, p<0.05), while blastocyst rates were difference between Fresh and MD or Straw (4.31% vs. 0.62% and 0%, respectively; p<0.05). In conclusion, the results indicate that the vitrified bovine oocytes have the ability to develop to the blastocyst stage after IVF.

Recent Progress in Air-Conditioning and Refrigeration Research : A Review of Papers Published in the Korean Journal of Air-Conditioning and Refrigeration Engineering in 2013 (설비공학 분야의 최근 연구 동향 : 2013년 학회지 논문에 대한 종합적 고찰)

  • Lee, Dae-Young;Kim, Sa Ryang;Kim, Hyun-Jung;Kim, Dong-Seon;Park, Jun-Seok;Ihm, Pyeong Chan
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
    • /
    • v.26 no.12
    • /
    • pp.605-619
    • /
    • 2014
  • This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2013. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) The research works on the thermal and fluid engineering have been reviewed as groups of fluid machinery, pipes and relative parts including orifices, dampers and ducts, fuel cells and power plants, cooling and air-conditioning, heat and mass transfer, two phase flow, and the flow around buildings and structures. Research issues dealing with home appliances, flows around buildings, nuclear power plant, and manufacturing processes are newly added in thermal and fluid engineering research area. (2) Research works on heat transfer area have been reviewed in the categories of heat transfer characteristics, pool boiling and condensing heat transfer and industrial heat exchangers. Researches on heat transfer characteristics included the results for general analytical model for desiccant wheels, the effects of water absorption on the thermal conductivity of insulation materials, thermal properties of Octadecane/xGnP shape-stabilized phase change materials and $CO_2$ and $CO_2$-Hydrate mixture, effect of ground source heat pump system, the heat flux meter location for the performance test of a refrigerator vacuum insulation panel, a parallel flow evaporator for a heat pump dryer, the condensation risk assessment of vacuum multi-layer glass and triple glass, optimization of a forced convection type PCM refrigeration module, surface temperature sensor using fluorescent nanoporous thin film. In the area of pool boiling and condensing heat transfer, researches on ammonia inside horizontal smooth small tube, R1234yf on various enhanced surfaces, HFC32/HFC152a on a plain surface, spray cooling up to critical heat flux on a low-fin enhanced surface were actively carried out. In the area of industrial heat exchangers, researches on a fin tube type adsorber, the mass-transfer kinetics of a fin-tube-type adsorption bed, fin-and-tube heat exchangers having sine wave fins and oval tubes, louvered fin heat exchanger were performed. (3) In the field of refrigeration, studies are categorized into three groups namely refrigeration cycle, refrigerant and modeling and control. In the category of refrigeration cycle, studies were focused on the enhancement or optimization of experimental or commercial systems including a R410a VRF(Various Refrigerant Flow) heat pump, a R134a 2-stage screw heat pump and a R134a double-heat source automotive air-conditioner system. In the category of refrigerant, studies were carried out for the application of alternative refrigerants or refrigeration technologies including $CO_2$ water heaters, a R1234yf automotive air-conditioner, a R436b water cooler and a thermoelectric refrigerator. In the category of modeling and control, theoretical and experimental studies were carried out to predict the performance of various thermal and control systems including the long-term energy analysis of a geo-thermal heat pump system coupled to cast-in-place energy piles, the dynamic simulation of a water heater-coupled hybrid heat pump and the numerical simulation of an integral optimum regulating controller for a system heat pump. (4) In building mechanical system research fields, twenty one studies were conducted to achieve effective design of the mechanical systems, and also to maximize the energy efficiency of buildings. The topics of the studies included heating and cooling, HVAC system, ventilation, and renewable energies in the buildings. Proposed designs, performance tests using numerical methods and experiments provide useful information and key data which can improve the energy efficiency of the buildings. (5) The field of architectural environment is mostly focused on indoor environment and building energy. The main researches of indoor environment are related to infiltration, ventilation, leak flow and airtightness performance in residential building. The subjects of building energy are worked on energy saving, operation method and optimum operation of building energy systems. The remained studies are related to the special facility such as cleanroom, internet data center and biosafety laboratory. water supply and drain system, defining standard input variables of BIM (Building Information Modeling) for facility management system, estimating capability and providing operation guidelines of subway station as shelter for refuge and evaluation of pollutant emissions from furniture-like products.

Development and validation of an analytical method for fungicide fenpyrazamine determination in agricultural products by HPLC-UVD (HPLC-UVD를 이용한 살균제 fenpyrazamine의 시험법 개발 및 검증)

  • Park, Hyejin;Do, Jung-Ah;Kwon, Ji-Eun;Lee, Ji-Young;Cho, Yoon-Jae;Kim, Heejung;Oh, Jae-Ho;Rhee, Kyu-Sik;Lee, Sang-Jae;Chang, Moon-Ik
    • Analytical Science and Technology
    • /
    • v.27 no.3
    • /
    • pp.172-180
    • /
    • 2014
  • Fenpyrazamine which is a pyrazole fungicide class for controlling gray mold, sclerotinia rot, and Monilinia in grapevines, stone fruit trees, and vegetables has been registered in republic of Korea in 2013 and the maximum residue limits of fenpyrazamine is set to grape, peach, and mandarin as 5.0, 2.0, and 2.0 mg/kg, respectively. Very reliable and sensitive analytical method for determination of fenpyrazamine residues is required for ensuring the food safety in agricultural products. Fenpyrazamine residues in samples were extracted with acetonitrile, partitioned with dichloromethane, and then purified with silica-SPE cartridge and eluted with hexane and acetone mixture. The purified samples were determined by HPLC-UVD and confirmed with LC-MS and quantified using external standard method. Linear range of fenpyrazamine was between $0.1{\sim}5.0{\mu}g/mL$ with the correlation coefficient (r) 0.999. The average recovery ranged from 71.8 to 102.7% at the spiked level of 0.05, 0.5, and 5.0 mg/kg, while the relative standard deviation was between 0.1 and 7.3%. In addition, limit of detection and limit of quantitation were 0.01 and 0.05 mg/L, respectively. The results revealed that the developed and validated analytical method is possible for fenpyrazamine determination in agricultural product samples and will be used as an official analytical method.

Recent Progress in Air-Conditioning and Refrigeration Research : A Review of Papers Published in the Korean Journal of Air-Conditioning and Refrigeration Engineering in 2012 (설비공학 분야의 최근 연구 동향 : 2012년 학회지 논문에 대한 종합적 고찰)

  • Han, Hwataik;Lee, Dae-Young;Kim, Sa Ryang;Kim, Hyun-Jung;Choi, Jong Min;Park, Jun-Seok;Kim, Sumin
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
    • /
    • v.25 no.6
    • /
    • pp.346-361
    • /
    • 2013
  • This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2012. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. The conclusions are as follows : (1) The research works on thermal and fluid engineering have been reviewed as groups of fluid machinery, pipes and valves, fuel cells and power plants, ground-coupled heat pumps, and general heat and mass transfer systems. Research issues are mainly focused on new and renewable energy systems, such as fuel cells, ocean thermal energy conversion power plants, and ground-coupled heat pump systems. (2) Research works on the heat transfer area have been reviewed in the categories of heat transfer characteristics, pool boiling and condensing heat transfer, and industrial heat exchangers. Researches on heat transfer characteristics included the results for natural convection in a square enclosure with two hot circular cylinders, non-uniform grooved tube considering tube expansion, single-tube annular baffle system, broadcasting LED light with ion wind generator, mechanical property and microstructure of SA213 P92 boiler pipe steel, and flat plate using multiple tripping wires. In the area of pool boiling and condensing heat transfer, researches on the design of a micro-channel heat exchanger for a heat pump, numerical simulation of a heat pump evaporator considering the pressure drop in the distributor and capillary tubes, critical heat flux on a thermoexcel-E enhanced surface, and the performance of a fin-and-tube condenser with non-uniform air distribution and different tube types were actively carried out. In the area of industrial heat exchangers, researches on a plate heat exchanger type dehumidifier, fin-tube heat exchanger, an electric circuit transient analogy model in a vertical closed loop ground heat exchanger, heat transfer characteristics of a double skin window for plant factory, a regenerative heat exchanger depending on its porous structure, and various types of plate heat exchangers were performed. (3) In the field of refrigeration, various studies were executed to improve refrigeration system performance, and to evaluate the applicability of alternative refrigerants and new components. Various topics were presented in the area of refrigeration cycle. Research issues mainly focused on the enhancement of the system performance. In the alternative refrigerant area, studies on CO2, R32/R152a mixture, and R1234yf were performed. Studies on the design and performance analysis of various compressors and evaporator were executed. (4) In building mechanical system research fields, twenty-nine studies were conducted to achieve effective design of mechanical systems, and also to maximize the energy efficiency of buildings. The topics of the studies included heating and cooling, HVAC system, ventilation, renewable energy systems, and lighting systems in buildings. New designs and performance tests using numerical methods and experiments provide useful information and key data, which can improve the energy efficiency of buildings. (5) In the fields of the architectural environment, studies for various purposes, such as indoor environment, building energy, and renewable energy were performed. In particular, building energy-related researches and renewable energy systems have been mainly studied, reflecting interests in global climate change, and efforts to reduce building energy consumption by government and architectural specialists. In addition, many researches have been conducted regarding indoor environments.

Recent Progress in Air-Conditioning and Refrigeration Research: A Review of Papers Published in the Korean Journal of Air-Conditioning and Refrigeration Engineering in 2014 (설비공학 분야의 최근 연구 동향: 2014년 학회지 논문에 대한 종합적 고찰)

  • Lee, Dae-Young;Kim, Sa Ryang;Kim, Hyun-Jung;Kim, Dong-Seon;Park, Jun-Seok;Ihm, Pyeong Chan
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
    • /
    • v.27 no.7
    • /
    • pp.380-394
    • /
    • 2015
  • This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2014. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) The research works on the thermal and fluid engineering have been reviewed as groups of heat and mass transfer, cooling and heating, and air-conditioning, the flow inside building rooms, and smoke control on fire. Research issues dealing with duct and pipe were reduced, but flows inside building rooms, and smoke controls were newly added in thermal and fluid engineering research area. (2) Research works on heat transfer area have been reviewed in the categories of heat transfer characteristics, pool boiling and condensing heat transfer and industrial heat exchangers. Researches on heat transfer characteristics included the results for thermal contact resistance measurement of metal interface, a fan coil with an oval-type heat exchanger, fouling characteristics of plate heat exchangers, effect of rib pitch in a two wall divergent channel, semi-empirical analysis in vertical mesoscale tubes, an integrated drying machine, microscale surface wrinkles, brazed plate heat exchangers, numerical analysis in printed circuit heat exchanger. In the area of pool boiling and condensing, non-uniform air flow, PCM applied thermal storage wall system, a new wavy cylindrical shape capsule, and HFC32/HFC152a mixtures on enhanced tubes, were actively studied. In the area of industrial heat exchangers, researches on solar water storage tank, effective design on the inserting part of refrigerator door gasket, impact of different boundary conditions in generating g-function, various construction of SCW type ground heat exchanger and a heat pump for closed cooling water heat recovery were performed. (3) In the field of refrigeration, various studies were carried out in the categories of refrigeration cycle, alternative refrigeration and modelling and controls including energy recoveries from industrial boilers and vehicles, improvement of dehumidification systems, novel defrost systems, fault diagnosis and optimum controls for heat pump systems. It is particularly notable that a substantial number of studies were dedicated for the development of air-conditioning and power recovery systems for electric vehicles in this year. (4) In building mechanical system research fields, seventeen studies were reported for achieving effective design of the mechanical systems, and also for maximizing the energy efficiency of buildings. The topics of the studies included energy performance, HVAC system, ventilation, and renewable energies, piping in the buildings. Proposed designs, performance performance tests using numerical methods and experiments provide useful information and key data which can improve the energy efficiency of the buildings. (5) The field of architectural environment was mostly focused on indoor environment and building energy. The main researches of indoor environment were related to the evaluation of work noise in tunnel construction and the simulation and development of a light-shelf system. The subjects of building energy were worked on the energy saving of office building applied with window blind and phase change material(PCM), a method of existing building energy simulation using energy audit data, the estimation of thermal consumption unit of apartment building and its case studies, dynamic window performance, a writing method of energy consumption report and energy estimation of apartment building using district heating system. The remained studies were related to the improvement of architectural engineering education system for plant engineering industry, estimating cooling and heating degree days for variable base temperature, a prediction method of underground temperature, the comfort control algorithm of car air conditioner, the smoke control performance evaluation of high-rise building, evaluation of thermal energy systems of bio safety laboratory and a development of measuring device of solar heat gain coefficient of fenestration system.

A survey on status of quality and risk assessment in dentifrices and mouthwashes (치약제 및 구중청량제의 품질 실태 조사 및 안전성 평가)

  • Jaeeun Kwak;Wonhee Park;Hoejin Ryu;Jin Han;Jeongeun Choe;Sungdan Kim;Insook Hwang;Yongseung Shin
    • Analytical Science and Technology
    • /
    • v.36 no.6
    • /
    • pp.300-314
    • /
    • 2023
  • The quality of the products was investigated by analyzing fluorine content, pH, preservatives and tar colors in 31 dentifrice products (6 items for children) and 15 mouthwash products (2 items for children) marketed. It was intended to provide correct information to consumers by checking whether the standards and product indications match. As a result of measuring the fluoride concentration, 26 dentifrice and 15 mouthwash products contained from 48 to 1,472 ppm and from 85 to 225 ppm, respectively. Fluorine detection rates of dentifrice and mouthwash products were 83.9 and 83.3 %, respectively showing similar levels. Of the 41 fluoride-detected dentifrice and mouthwash products, 40 were 90.7~109.8 % of the displayed amount and suitable for the fluorine content standard of 90.0 to 110.0 %, but one dentifrice was found to be inappropriate at 36.3 % of the content indicated on the product. The pH of the dentifrice was 5.1~9.4, and the mouthwash was 4.2~6.2, which met all standards. As a result of simultaneous analysis of the concentration of six preservatives, benzoic acid was detected the most in 15 cases with a 30.6 % detection rate, sorbic acid was detected in 9 cases (detection rate of 18.4 %), and all four types of methyl p-hydroxybenzoate, ethyl p-hydroxybenzoate, propyl p-hydroxybenzoate, butyl p-hydroxybenzoate were not detected. As a result of analyzing the concentration of 10 types of tar colors, six types including red40, yellow4, yellow5, yellow203, green3, and blue1 were detected in a total of 9 cases (2 dentifrices and 7 mouthwashes) with blue1 being the most frequently detected. Detected fluorine concentration, added preservatives and tar colors were consistent with the product markings and it was well written on product packaging. The detected preservatives and tar colors were at a safe level due to low risk compared to Acceptable Daily Intake.