冠岳樹木園地域內 荒廢山地土壤의 肥沃化를 통한 綠化促進에 關한 硏究

李宗學,麻鎬燮,李憲浩,權台鎬,禹保命 서울大學校 農科大學 1984 서울대농학연구지 Vol.9 No.2

冠岳樹木園地域의 山復斜面은 地質的으로 대보화강암에서 풍화생성된 거친 돌부수러기가 많은 粗砂質壤土로 구성되었으므로 表土層의 土壤流矢이 심하여 土深이 대단히 얕거나 岩盤露出이 심하여 林木生長이 심히 不良한 地帶로서, 山地의 地力恢復 및 現存하는 散生樹木의 生長力恢復을 通한 山地綠化保全이 시급히 요청되고 있다. 이와같은 요청에 부응하여 荒廢地斜面에 自生하고 있는 주요한 4樹種(소나무, 리기다소나무, 노간주나무, 철쭉)에 대하여 山地施肥效果 試驗을 春期와 秋期로 나누어 실시한 결과 樹高 및 直徑生長量에 있어서 無施肥區에 比하여 현저한 施肥效果가 인정되었다. 따라서 冠岳山地帶의 荒廢地를 조속히 復舊綠化하기 위해서는 砂防土木的 工事方法 및 砂方造林的 播植方法이외에도 현존 수목의 保全 및 生長力恢復을 통한 速成綠化方法도 채용되어야 할 것이다. Hillsides in the Kwanak arboretum area were composed mainly of coarse sandy loam having relatively high proportion of rough weathered debris derived from the Daebo granite geologically. Owing to heavy soil erosion resulted to shallow soil depth and heavy rock exposures, the growing trees in this type of surface soil are very poor in their growth. For woody plant vegetation establishment in this montain area, it is urgent to recover the fertility of soil and the growth of existing trees. For this purpose, in spring and autumn season in 1983~84 the fertilization experiment was conducted with the 4 principal native species(Pinus densifltora, Pinus rigida, Juniperus rigida, Rhododendron schlippenbachii) growing in this denuded forest land, and the effects of fertilized tree plots were more prominent than the control plot in both height and root-collar diameter growth. Therefore, the accelerating measures of vegetation rehabilitation through conservation of existing trees and recovery of tree growth by forest fertilization practices, besides forest engineering measur es and soil erosion control afforestation measures, could be acceptable as the measures for the recovery of denuded forest land in Mt. Kwanak area.

冠岳樹木園地域內 荒廢山地土壤의 肥沃化를 통한 綠化促進에 關한 硏究

李宗學,麻鎬燮,權台鎬,李憲浩,禹保命 서울大學校農業生命科學大學附屬樹木園 1984 서울大學校 樹木園 硏究報告 Vol.- No.5

冠岳樹木園地域의 山腹斜面은 地質的으로 대보화강암에서 풍화생성된 거친 돌부수러기가 많은 粗砂質壤土로 구성되었으므로 表土層의 土壤流失이 심하여 土深이 대단히 얕거나 岩盤露出이 심하여 林木生長이 심히 不良한 地帶로서,山地의 地力恢復 및 現存하는 散生樹木의 生長力恢復을 通한 山地綠化保全이 시급히 요청되고 있다. 이와같은 요청에 부응하여 荒廢地斜面에 自生하고있는 주요한 4樹種(소나무, 리기다소나무, 노간주나무, 철쭉)에 대하여 山地施肥效果 試驗을 春期와 秋期로 나누어 실시한 결과 樹高 및 直徑生長量에 있어서 無施肥區에 比하여 현저한 施肥效果가 인정되었다. 따라서 冠岳山地帶의 荒廢地를 조속히 復舊綠化하기 위해서는 砂防土木的 工事方法 및 砂防造林的 播植方法이외에도 현존 수목의 保全 및 生長力恢復을 통한 速成綠化方法도 채용되어야 할 것이다. Hillsides in the Kwanak arboretum area were composed mainly of coarse sandy loam having relatively high proportion of rough weathered debris derived from the Daebo granite geologically. Owing to heavy soil erosion resulted to shallow soil depth and heavy rock exposures, the growing trees in this type of surface soil are very poor in their growth. For woody plant vegetation establishment in this montain area, it is urgent to recover the fertility of soil and the growth of existing trees. For this purpose, in spring and autumn season in 1983∼84 the fertilization experiment was conducted with the 4 principal native species(Pinus densiflora, Pinus rigida, Juniperus rigida, Rhododendron schlippenbachii) growing in this denuded forest land, and the effects of fertilized tree plots were more prominent than the control plot in both height and root-collar diameter growth. Therefore, the accelerating measures of vegetation rehabilitation through conservation of existing trees and recovery of tree growth by forest fertilization practices, besides forest engineering measur es and soil erosion control afforestation measures, could be acceptable as the measures for the recovery of denuded forest land in Mt. Kwanak area.

Al합금의 고속 원통가공에서 발생하는 치수오차와 진원도의 영향 고찰

윤종학,서성원,이헌철 한국공작기계학회 2001 한국생산제조학회지 Vol.10 No.5

Recently, the requirements for high precision and efficiency machining are gradually increased to raise international competitiveness at the industrial fields of die and molds. This trend had made effects on the industrial fields in Korea and which needs for studying of high precision and efficiency machining. This study is to investigate the effects of the run-out of end mill in the external cylindrical machining operated by solid carbide end mills with Al-alloy in high speed machining center relating to high spindle revolution and fast feed per minute on the dimensional precision, roundness of workpiece. From the results of experimentation followings are obtained; when Al-alloy is processed by the external cylindrical cutting of end milling through the high speed revolution, if the spindle revolution is higher relating to radial depth of cut, feed per tooth in very lower situation, finally, productivity can be raised because high precision and quality products are machined high efficiently.

AI합금의 고속가공에서 치수오차와 표면정도 추이 고찰

윤종학,정문섭,이헌철 韓國工作機械學會 2000 한국생산제조학회지 Vol.9 No.3

High speed machining aims to raise the productivity and efficiency by making more precise and higher value-added products than any other machining method by means of the high speediness of spindle and feed drive system. The purpose of this study is to investigate the effects of the run-out of endmill on the dimension precision of workpiece and to obtain the fundamental data on high speed machining, which is available by machining the side of Al-alloy with solid carbide endmills in high speed machining center and by measuring dimensions and surface roughness. From the results of experimentations followings are obtained ; if spindle speed is ultrahigh in conditions that radial depth of cut and feed per tooth are very small, highly precise and accurate products are to be made efficiently with high feed rate, and so we can raise productivity.

고속가공용 엔드밀의 동특성 분석

임경화,유중학,이우영,장헌탁 한국공작기계학회 2004 한국공작기계학회 춘계학술대회논문집 Vol.2004 No.-

Performance Evaluation of end mills for high speed cutting has been performed in a view of dynamic characteristics and noise-vibration under operation. The tools tested in this research consist of three foreign country made and one korean made. In addition, numerical models using finite element method are established, which are confirmed by experimental results. The evaluation results has been feedback for developing high performance end mills for high speed cutting tools.

Pretreatment and enzymatic saccharification process of rapeseed straw for production of bioethanol

Heon-Hak Lee,Min-Ki Jeon,Min-Ho Yoon 충남대학교 농업과학연구소 2016 Korean Journal of Agricultural Science Vol.43 No.4

Stage-specific expression of DDX4 and c-kit at different developmental stages of the porcine testis

Lee, Ran,Lee, Won-Young,Park, Hyun-Jung,Ha, Woo-Tae,Woo, Jae-Seok,Chung, Hak-Jae,Lee, Ji-Heon,Hong, Kwonho,Song, Hyuk Elsevier 2018 Animal reproduction science Vol.190 No.-

<P><B>Abstract</B></P> <P>Spermatogenesis begins with spermatogonial stem cells (SSCs), which are located in the basement membrane of the adult testes. Previous studies have described specific biomarkers for undifferentiated porcine spermatogonia or SSCs; however, these markers are not sufficient to understand spermatogenesis at different developmental stages. The objective of this study was characterize the expression of DEAD-Box polypeptide 4 (DDX4, also known as VASA) and tyrosine-protein kinase kit (c-kit), as potential markers of male germ cells in the porcine testis. In porcine testis tissue at prepubertal stages (5, 30, and 60 days), DDX4 and c-kit protein expression was detected in the most undifferentiated spermatogonia, which also express protein gene product 9.5 (PGP9.5). However, in porcine testis tissues from pubertal and postpubertal stages (90, 120, and 150 days), DDX4 and c-kit were not detected in PGP9.5-positive undifferentiated spermatogonia. The DDX4 expression pattern was similar to that of c-kit in the porcine testis. In adult porcine testes, DDX4-expressing cells were located on the lumenal side, compared to synaptonemal complex protein 3-positive primary spermatocytes, but DDX-4 was not co-expressed with acrosin, a known acrosome marker. In addition, DDX4 was detected in PGP9.5-expressing porcine SSCs in culture. Based on our results, we suggest that DDX4 and c-kit are putative markers of undifferentiated spermatogonia in the prepubertal porcine testis. While in the postpubertal porcine testis, they are markers of differentiated spermatocytes. These findings may facilitate future studies of porcine spermatogenesis.</P> <P><B>Highlights</B></P> <P> <UL> <LI> DDX4 and C-kit were detected in pocine undifferentiated spermatogonia at prepubertal stages. </LI> <LI> DDX4 and C-kit were detected in porcine spermatocyte at postpubertal stages. </LI> <LI> DDX4 expressed spermatocyte was not detected SCP3 and acrosin. </LI> <LI> DDX4 detected in <I>in-vitro</I> cultured porcine undifferentiated spermatogonia. </LI> </UL> </P>

각종 위질환에 있어서의 혈청 gastrin 치에 관한 임상적 연구

이용덕,이학중,이종석,이헌실,박승억,박성휘 대한핵의학회 1981 핵의학 분자영상 Vol.15 No.2

The fasting serum gastrin levels were measured by radioimmunoassay in 32 normal healthy subjects without recognized gastrointestinal symptoms and 93 patients with various gastric diseases, who were visited of admitted to National Medical Center from February to June, 1981. The following results were obtained; 1) The fasting mean serum gastrin level in normal subjects was 55.9±26.3 pg/m1, and there was no difference between male and female. 2) The gastrin levels in gastric and duodenal ulcer were 85.0±28.4 and 76.0±43.0 pg/ml respectively, and it's values were elevated as compared with normal subjects. In gastric ulcer, the gastrin level was elevated than that of duodenal ulcer, but no significant difference in each other. 3) The gastrin level in stomach cancer was 89.5±42.2 pg/ml, and it's values were markedly elevated as compared with values in normal subjects. 4) The gastrin level in gastritis was 73.4±37. 4 pg/ml, and it's values were elevated as compared with values in normal subjects. 5) The gastrinl in post-gastrectomy state was 50.3±16.3 pg/ml, and it's values were slightly decreased as compared with values in normal subjects.

Development of succinate producing Cellulomonas flavigena mutants with deleted succinate dehydrogenase gene

Heon-Hak Lee,Min-Ki Jeon,Min-Ho Yoon 충남대학교 농업과학연구소 2017 Korean Journal of Agricultural Science Vol.44 No.1

Confirming Single Nucleotide Polymorphisms from Expressed Sequence Tag Datasets Derived from Three Cattle cDNA Libraries

Lee, Seung-Hwan,Park, Eung-Woo,Cho, Yong-Min,Lee, Ji-Woong,Kim, Hyoung-Yong,Lee, Jun-Heon,Oh, Sung-Jong,Cheong, Il-Cheong,Yoon, Du-Hak Korean Society for Biochemistry and Molecular Biol 2006 Journal of biochemistry and molecular biology Vol.39 No.2

Using the Phred/Phrap/Polyphred/Consed pipeline established in the National Livestock Research Institute of Korea, we predicted candidate coding single nucleotide polymorphisms (cSNPs) from 7,600 expressed sequence tags (ESTs) derived from three cDNA libraries (liver, M. longissimus dorsi, and intermuscular fat) of Hanwoo (Korean native cattle) steers. From the 7,600 ESTs, 829 contigs comprising more than two EST reads were assembled using the Phrap assembler. Based on the contig analysis, 201 candidate cSNPs were identified in 129 contigs, in which transitions (69%) outnumbered transversions (31%). To verify whether the predicted cSNPs are real, 17 SNPs involved in lipid and energy metabolism were selected from the ESTs. Twelve of these were confirmed to be real while five were identified as artifacts, possibly due to expressed sequence tag sequence error. Further analysis of the 12 verified cSNPs was performed using the program BLASTX. Five were identified as nonsynonymous cSNPs, five were synonymous cSNPs, and two SNPs were located in 3'-UTRs. Our data indicated that a relatively high SNP prediction rate (71%) from a large EST database could produce abundant cSNPs rapidly, which can be used as valuable genetic markers in cattle.