• Title/Summary/Keyword: the year of chemistry

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Effect of soil organic matter content on plant uptake factor of ginseng for endosulfan (토양유기물 함량이 인삼근의 endosulfan 흡수이행에 미치는 영향)

  • Oh, Kyeong-Yeol;Choi, Geun-Hyoung;Bae, Ji-Yeon;Lee, Deuk-Yeong;Lee, Sung-Woo;Kim, Jin-Hyo
    • Journal of Applied Biological Chemistry
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    • v.63 no.4
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    • pp.401-406
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    • 2020
  • The plant uptake of endosulfan, a new persistent organic pollutants from soil environment was investigated on ginseng through the field survey in Korea. The endosulfan residues in soil for this survey were ranged on 0.013-0.136 mg kg-1. The plant uptake factor (PUF) for endosulfan in ginseng was 0.243-1.708 and the highest PUF was found on 3-year-old ginseng. The PUF for endosulfan decreased in the longer cultivation period and it might be caused by the dilution effect of ginseng growth. In addition, the soil organic matter (SOM) content affected on the PUF negatively and Pearson correlation coefficient (r) between SOM and PUF was -0.7812 (p <0.05). Thus, higher SOM would positively affect to reduce the endosulfan residue in ginseng root.

Analysis of Students' Responses on the Items of Chemistry II in the College Scholastics Ability Test (대학수학능력시험 화학II 문항에 대한 학생들의 응답 분석)

  • Hong, Mi-Young;Jeon, Kyung-Moon;Yi, Bum-Hong;Lee, Yang-Rak
    • Journal of The Korean Association For Science Education
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    • v.22 no.1
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    • pp.204-213
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    • 2002
  • In this study, the students' responses on the items of chemistry II in the College Scholastics Ability Test (CSAT) implemented for the past 3 years since 1999 was investigated. The number of applicants and mean score of chemistry II, average percent correct by contents and inquiry process, and the items with high and/or low percent correct are analysed and discussed. The percentage of applicants for natural science track is reduced each year. However, more than 25% of natural science track applied to chemistry II, which ranked second to biology II. The mean score of chemistry II was increased in 2001 along with those of other subjects. There is no difference in average percent correct either by contents or inquiry process. Students performed generally poor at solving test items relating to 'colligative properties of solution' such as 'boiling point elevation' or 'osmotic pressure', and very well at solving test items relating to 'reaction rates'. Educational implications are discussed.

Synthesis and Anti-corrosion Properties of Succinic Acid Alkyl Half-amide Derivatives (숙신산 알킬 하프-아마이드 유도체의 합성 및 해수에 대한 방청성능)

  • Baek, Seung-Yeob;Kim, Young-Wun;Chung, Keun-Wo;Yoo, Seung-Hyun;Kim, Nam-Kyun
    • Clean Technology
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    • v.17 no.4
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    • pp.314-324
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    • 2011
  • Several amide derivatives have been used as additives for base oil of metal working fluids and pressure working oils. In this paper, a series of succinic acid alkyl half-amide derivatives were synthesized as over 97% yields by ring-opening reaction of succinic anhydride and several amines and were soluble in 100 N base oil within 1 wt% concentration. The structures of the synthesized amides were confirmed by $^1H$-NMR, FT-IR spectrum and GC analysis. Anti-corrosion properties of the amides in sea water were evaluated through ASTM D665 method and weight loss method. As the results of anti-corrosion properties, the properties of the amides with shorter alkyl chain and high concentration showed better performance than those with longer alkyl chain and low concentration. Also, the dialkyl amides showed better anti-corrosion properties than those of the monoalkyl amides. Inhibition efficiency% (IE%) was over 93% in the concentration of 40 ppm and corrosion rate (CR) was below 0.5 mm/year in the same concentration.

Factors Associated with the Concentrations of Urinary Creatinine in Korean Children and Adolescents (한국 어린이와 청소년의 요중 크레아티닌 농도와 영향요인에 대한 연구)

  • Lee, Jin-Heon;Ahn, Ryeong-Mi;Kang, Hee-Sook;Choi, Suk-Nam;Hong, Chun-Pyo;Kim, Jin-Gyong
    • Journal of Environmental Health Sciences
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    • v.38 no.4
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    • pp.291-299
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    • 2012
  • Creatinine-adjustment is an important process in the urinary monitoring of the environmental exposure of children and adolescents. The purpose of this study was to investigate the concentrations of urinary creatinine and factors associated with them among Korean children and adolescents. We recruited 1,025 persons from 128 extracted schools. They were from three to 18 years old and supplied urine samples for measuring creatinine. The concentrations of urinary creatinine were 98.18 mg/dl (SD, 67.67) in arithmetic mean and 72.05 mg/dl (GSD 2.49) in geometric mean, were significantly higher among male children/adolescents than females in all age groups, and higher values appeared following increasing ages, heights and BMIs. The rates of the number who were below the lowest limit recommended by WHO (<30 mg/dl) were 25.57% among three to four year olds, 21.77% among five to six year olds, 20.0% among seven to eight year olds and 14.69% among nine to ten year olds, respectively. The rates of those above the highest limit (>300 mg/dl) were 0.0% among three to twelve year olds. The coefficient of determination R-square of the fitted regression model for urinary creatinine was 27.4% with general characteristic variables of sex, age, BMI and height. The significant variables among these were height (standardized beta = 0.372) and age (standardized beta = 0.129). Another coefficient of determination R-square was 15.3% with dietary habit variables of smoking, drinking, dining area, number of meals and snacks, and intake of milk food, cup-noodles, canned foods, popcorn, nachos, and hamburgers. In conclusion, the concentration of urinary creatinine was significantly lower in children than in adults, and was very significantly associated with the height of children. Therefore, children need the recommended concentrations for urinary creatinine, as distinguished from adults.

A Survey of Pesticide Residues of Citrus Fruits and Citrus Orchard Soil in Jeju Island - Part 2. On the Pesticide Residue of Citrus Orchard Soil - (제주도(濟州道)의 감귤(柑橘)및 감귤원토양(柑橘園土壤)에 관(關)한 잔류농약조사(殘留農藥調査) - 제2보(第二報), 감귤원(柑橘園) 토양중(土壤中)의 농약잔류(農藥殘留)에 관(關)하여 -)

  • Lee, Kyu-Seung
    • Applied Biological Chemistry
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    • v.23 no.3
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    • pp.184-188
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    • 1980
  • A survey of pesticide and copper residues of the citrus orchard soil was conducted during October 1979-June 1980 in Jeju, Seogwipo county. The citrus orchards were classified into five groups according to different cultivated period; 5 year orchard, 10 year orchard, 15 year orchard, 20 year orchard, and 30 year orchard. Each of the above samples was divided again to three layers of soil depth; the surface layer$(0{\sim}10cm)$, the middle layer $(10{\sim}20cm)$, and the bottom layer $(20{\sim}40cm)$. In this experiments, Kelthane and Akar, as well as copper residues were detected in all soil samples. Residue levels of above chemicals were increased in soils of orchard with longer cultivation periods, and at the same time, decreased with soil depth. The residues of those ranged as follows; a) from trace to 1.359ppm in Kelthane, b) from trace to 0.925ppm in Akar, and c) from trace to 40.734ppm in copper. It is noted that the average residues of Kelthane was 0.251ppm, Akar, 0.120ppm, and that of copper was 2.168ppm, respectively.

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Annual Cycle of the Seminiferous Epithelium of Miniopterus schreibersi fuliginosus

  • Kang Mu-Shik;Lee Jung-Hun
    • Biomedical Science Letters
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    • v.10 no.4
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    • pp.435-445
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    • 2004
  • The characteristics of the testis and the annual cycle of the seminiferous epithelium of the Miniopterus schreibersi fuliginosus were examined by optical microscopy. The testis weight and diameter of the seminiferous tubules were increased gradually from May to July, and the highest activity was observed in August. The size then decreased rapidly from October. Spermatogenesis began in May, peaked in August, and was suspended from October to April in the following year. Spermatocytogenesis were produced from May to July. Spermiogenesis occurred from August to September. In particular, immature spematogenic cells in the seminiferous tubules were engulfed by the phagocytosis of Sertoli cells in October. From November to April, the seminiferous tubuly contained only Sertoli cells and Ad spermatogonia. Therefore, the periodic changes in the seminiferous epithelium of M. S. fuliginosus suggest that a long hibernation is an adaptive strategy for the preservation of energy and the regulation of the breeding cycle.

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A Study on Learners' Perceptions and Learning styles of Task Research (R&E) conducted by Science High School Students

  • Dong-Seon Shin;Jong Keun Park
    • International Journal of Advanced Culture Technology
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    • v.11 no.4
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    • pp.286-294
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    • 2023
  • We studied learners' perceptions and learning styles of project research activities in the chemical field conducted by 54 science high school students. In a survey of students' perceptions of task research, positive responses were found in "internal motivation," "cooperation," "task solving," and "tenacity and immersion," and statistically significant differences were found in "self-directedness," "cooperation," and "tenacity and immersion" by year. The 'lower' group responded most positively in the 'cooperation' category, and the 'higher' group responded most positively in the 'task solving' category. As a result of investigating the learning styles of the students who conducted the task research, it was found in the order of assimilator, converger, accommodator, and diverger. The assimilators showed the characteristic of systematically and scientifically approaching the problem. Convergers were found to have excellent problem-solving and decision-making ability, are practical, and have experimental-based thinking characteristics. In this study, the characteristics of science high school students showed well in the results of the learning style performed.

History of the Korean Society of Applied Entomology for its First Fifty Years (한국응용곤충학회의 첫 50년 역사)

  • Boo, Kyung-Saeng
    • Korean journal of applied entomology
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    • v.51 no.2
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    • pp.171-190
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    • 2012
  • The Korean Society of Applied Entomology (KSAE) celebrates its First 50 years history this year, 2011. It began in the year 1962, as the Korean Society of Plant Protection (KSPP) to discuss all aspects of plant protection including entomology and plant pathology. At that time it was one of the earliest scientific ones among agricultural societies in Korea. Before liberation from the Japanese colonial rule there were a few scientific societies for Japanese scientists only in the Korean Peninsula. It seemed that there was a single exception, in medical field, formed by and operated for Korean ethnics. Right after the liberation, Korean scientists rushed to form new scientific societies in the fields of mechanical engineering, architecture, textile, internal medicine, biology, etc. in 1945, mathematics, chemistry, metallurgy, etc. in 1946, and so on. But agricultural scientists had to wait for more time before setting up their own scientific society, Korean Agricultural Society(韓國農學會), comprising all agricultural subfields, in 1954. They had annual meetings and published their own journal every year until 1962. Then those working in the plant protection field established their own KSPP, right after their section meeting in 1962. At that time the total number of participants for KSPP were only around 50. KSPP scientists were interested in plant pathology, agricultural chemicals, weed science, or bioclimate, besides entomology. They had annual meetings once or twice a year until 1987 and published their own journal, Korean Journal of Plant Protection (KJPP), once a year at the earlier years but soon gradually increasing the frequency to four times a year later. Articles on entomology and plant pathology occupied about 40% each, but the number of oral or posters were a little bit higher on plant pathology than entomology, with the rest on nematology, agricultural chemicals, or soil microarthropods. There also had a number of symposia and special lectures. The presidentship lasted for two years and most of president served only one term, except for the first two. The current president should be $28^{th}$. In the year 1988, KSPP had to be transformed into the applied entomology society, Korean Society of Applied Entomology (KSAE), because most of plant pathologists participating left the society to set up their own one, Korean Society of Plant Pathology in 1984. Since that time the Society concentrates on entomology, basic and applied, with some notes on nematology, acarology, soil microarthropods, agricultural chemicals, etc. The Society has been hosting annual meetings at least twice a year with special lectures and symposia, from time to time, on various topics. It also hosted international symposia including binational scientific meetings twice with two different Japanese (applied entomology in 2003 and acarology in 2009) societies and the Asia-Pacific Congress of Entomology in 2005. The regular society meeting of this year, 2011, turns out to be the 43rd and this autumn non-regular meeting would be the 42nd. It has been publishing two different scientific journals, Korean Journal of Applied Entomology (KJAE) since 1988 and the Journal of Asia-Pacific Entomology (JAPE) since 1998. Both journals are published 4 times a year, with articles written in Korean or English in the first, but those in English only in the latter with cooperation from the Taiwan Entomological Society and the Malaysian Plant Protection Society since 2008. It is now enlisted as one of those SCI(science citation index) extended. The highest number of topics discussed at their annual meetings was on ecology, behavior, and host resistance. But at the annual meetings jointly with the Korean Society of Entomology, members were more interested in basic aspects, instead of applied aspects, such as physiology and molecular biology fields. Among those societies related to entomology and plant protection, plant pathology, pesticide, and applied entomology societies are almost similar in membership, but entomology and plant pathology societies are publishing more number of articles than any others. The Society is running beautifully, but there are a few points to be made for further improvement. First, the articles or posters should be correctly categorized on the journals or proceedings. It may be a good idea to ask members to give their own version of correct category for their submissions, either oral or poster or written publication. The category should be classified detailed as much as possible (one kind of example would be systematics, morphology, evolution, ecology, behavior, host preference or resistance, physiology, anatomy, chemical ecology, molecular biology, pathology, chemical control, insecticides, insecticide resistance, biocontrol, biorational control, natural enemies, agricultural pest, forest pest, medical pest, etc.) and such scheme should be given to members beforehand. The members should give one or two, first and second, choices when submitting, if they want. Then the categories might be combined or grouped during editing for optimal arrangement for journals or proceedings. Secondly the journals should carry complete content of the particular year and author index at the last issue of that year. I would also like to have other information, such as awards and awardees in handy way. I could not find any document for listing awards. Such information or article categorization may be assigned to one of the vice presidents. I would rather strongly recommend that the society should give more time and energy on archive management to keep better and more correct history records.

Preliminary study for aging of latent fingerprints on nonporous substrate

  • Nam Yee Kim;Woo-Yong ParK;Jong Shin Park;Yuna Kim;Hee Sook Kim
    • Analytical Science and Technology
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    • v.36 no.2
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    • pp.80-88
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    • 2023
  • Fingerprints play a crucial role in the identification of potential suspects in criminal cases. However, determining the actual time, i.e., the time at which the fingermark was deposited, is challenging. Herein, we investigated the persistence and aging of fingerprints over time by observing the time evolution of latent fingerprints on a polystyrene box stored in a dark room. Fingerprint samples that were stored for up to two years could be detected with maximum accuracy using a black iron-oxide-based emulsion (black emulsion). To estimate the time of fingerprint deposition, fingerprint aging was studied by analyzing the lipid components of the fingerprints after their development. Cholesterol and squalene were selected as indicators of fingerprint aging, and their ratio was estimated to assess aging. In the case of fingerprint samples stored in a dark room for up to one month after deposition, the cholesterol/squalene ratio was approximately 0.01; it increased gradually to ≥ 0.1 over six months. A substantial reduction in the levels of cholesterol and squalene from the initial levels was also noted. Cholesterol and squalene were not detected after one year of storage. Thus, the extent of aging could be determined by analyzing the aging indicators for up to six months. Two cases that could cause error in the estimation of the fingerprint deposition time, namely, heating of the fingerprint sample before development and storage of the developed fingerprints in a dark room, were also investigated.

Analysis of major ginsenosides in various ginseng samples

  • Lee, Dong Gu;Lee, Ju Sung;Kim, Kyung-Tack;Kim, Hyun Young;Lee, Sanghyun
    • Journal of Applied Biological Chemistry
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    • v.62 no.1
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    • pp.87-91
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    • 2019
  • The contents of major ginsenosides (ginsenosides Rb1, ginsenoside Rc, ginsenoside Rd, ginsenoside Re, ginsenoside Rf, and ginsenoside Rg1) in ginseng cultivated in different areas in Korea, ginseng that underwent different cultivation processes and ages, and ginseng cultivated in different countries were determined using high-performance liquid chromatography equipped with UV/VIS detector. Ginsenoside Rc was the most abundant ginsenoside in all different ginseng samples. The highest total concentration of major ginsenosides was found in the ginseng cultivated in Jinan (0.931 mg/g) and 4-year grown red ginseng (1.785 mg/g). Major ginsenosides were the most abundant in Korean ginseng (1.264 mg/g), compared to those in Chinese and American ginseng. The results of this study showed the different contents of major ginsenosides in the ginseng samples tested and emphasized which sample could contain high yield of ginsenosides.