• Title/Summary/Keyword: Reverse Plate

Search Result 179, Processing Time 0.024 seconds

A Study on the Mitigation of Welding Distortion of a Precision Component for Automobile Transmission (자동차 변속기용 정밀 부품의 용접변형 감소화에 관한 연구)

  • Chung, Hoi-Yoon;Kim, Jae-Woong;Yun, Seok-Chul
    • Journal of Welding and Joining
    • /
    • v.30 no.4
    • /
    • pp.31-37
    • /
    • 2012
  • In recent years, a demand for precision-welding is increasing in wide industrial fields for getting a high quality welded structures. Although laser welding is commonly used for precision-welding, gas tungsten arc (GTA) welding is also attempted as a precision-welding due to the cost benefit. However, welding heat causes an uneven temperature distribution leading to welding deformation. Since it causes geometric errors and degrades product quality, welding distortion recently rises as an important issue in the field of automobile parts. To control welding deformation, it is needed to design in shapes that can maximize stiffness against deformation during welding; control the welding sequence; minimize heat input; and weld allowing reverse deformation; etc. Thus it is necessary to find the one, among such approaches, that can minimize the deformation range by mathematical analysis and understand how effective it would be when it is actually used in industrial fields. This study performs analyses by numerical calculations and experiments for the De-Tent Lever, one of transmission part that requires precision the most among automobile parts, as the subject of experiment. Decrease in welding deformation is required for this part, since there is currently a trouble in guaranteeing precision due to angular deformation by welding between boss and plate. Finally the ways to minimize welding deformation has been suggested in this study through analyses on it.

Single- and Repeated-Dose Oral Toxicity in Rats and Bacterial Reverse Mutation Test of Morus alba L. Extracts (상지추출물의 단회/반복투여 독성 및 복귀돌연변이능 평가)

  • Han, Taewon;Um, Min Young;Lim, Young Hee;Kim, Jeong-Keun;Kim, In-Ho
    • Journal of the Korean Society of Food Science and Nutrition
    • /
    • v.45 no.10
    • /
    • pp.1406-1413
    • /
    • 2016
  • This study was carried out to evaluate the toxicity of ethanolic extracts of Morus alba L. branch (ME). In the reverse mutation test, Salmonella Typhimurium TA98, TA100, TA1535, TA1357, and Escherichia coli WP2uvrA were used to estimate the mutagenic potential of ME. Sprague-Dawley rats were orally administered ME at levels of 1,250, 2,500, and 5,000 mg/kg for the single-dose toxicity test and 500, 1,000, and 2,000 mg/kg/d for the repeated-dose toxicity test for 28 consecutive days. As expected, reverse mutation was not detected at any concentration of ME, regardless of application of the metabolic activation system with or without S9 mix. In the single-dose toxicity test, ME caused neither significant visible signs of toxicity nor mortality in rats, and $LD_{50}$ was estimated to be over 5,000 mg/kg. In the repeated-dose toxicity test, ME administration at 500, 1,000, and 2,000 mg/kg for 28 days to male or female rats did not result in mortality. Similarly, no toxicologically significant treatment-related changes in body weight, food intake, or organ weights were noted. Several hematological and biochemical parameters in both genders showed significant differences, but these were within normal ranges. These results support the safe use of ME.

Adhesion Characteristics and the High Pressure Resistance of Biofilm Bacteria in Seawater Reverse Osmosis Desalination Process (역삼투 해수담수화 공정 내 바이오필름 형성 미생물의 부착 및 고압내성 특성)

  • Jung, Ji-Yeon;Lee, Jin-Wook;Kim, Sung-Youn;Kim, In-S.
    • Journal of Korean Society of Environmental Engineers
    • /
    • v.31 no.1
    • /
    • pp.51-57
    • /
    • 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.

Isolation of Plasmid DNA and Physiological Characteristics of Rhizobium japonicum (Rhizobium japonicum의 생리적(生理的) 특성(特性) 및 Plasmid DNA의 분리(分離))

  • Oh, Seh Heun;Kang, Sang Jai;Park, Woo Churl
    • Current Research on Agriculture and Life Sciences
    • /
    • v.12
    • /
    • pp.69-82
    • /
    • 1994
  • This study was conducted to investigate the physiological characteristics and to isolate plasmid DNA of R. japonicum strains. The results obtained were as follows; Strains S117, S118, 005, 011 and DY-1 were slow-growers and showed alkaline reaction, whereas strains S110, S111, S114, S116, S120 and 010 were fast-growers and produced acid reaction in YEM broth. All the fast- and slow-growing R. japonicum showed gram negative and formed mucous white colony on agar plate. After 7 days, the colonies of the fast-growers were between 2.0 and 4.0mm in diameter, whereas those of slow-growers were approximately between 0.5 and 1.5mm. The fast-growers were uniformly sensitive to the pH of 4.5 and tolerant of the pH of 9.5, whereas the reverse was found for the slow-growers. All the fast-growers were able to grow in the presence of 2% NaCl however the slow-growers were not grown. All the microorganisms grew rapidly in simple mineral salt medium containing as the sole source of carbon. Starch was rarely utilized. All the fast-growers utilized sucrose. The slow-growing R. japonicum strains examined usually contained 1 to 3 plasmid DNA ranging between 15Kb and 250 Kb, whereas the fast-growing R. japonicum strains contained 1 to 3 plasmid DNA ranging from 20 Kb to 250Kb.

  • PDF

High-resolution Seismic Imaging of Shallow Geology Offshore of the Korean Peninsula: Offshore Uljin (신기 지구조운동의 해석을 위한 한반도 근해 천부지질의 고해상 탄성파 탐사: 울진 주변해역)

  • Kim, Han-Joon;Jou, Hyeong-Tae;Yoo, Hai-Soo;Kim, Kwang-Hee;You, Lee-Sun
    • Geophysics and Geophysical Exploration
    • /
    • v.14 no.2
    • /
    • pp.127-132
    • /
    • 2011
  • We acquired and interpreted more than 650 km of high-resolution seismic reflection profiles in the Hupo Basin, offshore east coast of Korea at $37^{\circ}N$ in the East Sea (Japan Sea) to image shallow and basement deformation. The seismic profiles reveal that the main depocenter of the Hupo Basin in the study area is bounded by the large offset Hupo Fault on the east and an antithetic fault on the west; however, the antithetic fault is much smaller both in horizontal extension and in vertical displacement than the Hupo Fault. Sediment infill in the Hupo Basin consists of syn-rift (late Oligocene. early Miocene) and post-rift (middle Miocene.Holocene) units. The Hupo Fault and other faults newly defined in the Hupo Basin strike dominantly north and show a sense of normal displacement. Considering that the East Sea has been subjected to compression since the middle Miocene, we interpret that these normal faults were created during continental rifting in late Oligocene to early Miocene times. We suggest that the current ENE direction of maximum principal compressive stress observed in and around the Korean peninsula associated with the motion of the Amurian Plate induces the faults in the Hupo Basin to have reverse and right-lateral, strike-slip motion, when reactivated. A recent earthquake positioned on the Hupo Fault indicates that in the study area and possibly further in the eastern Korean margin, earthquakes would occur on the faults created during continental rifting in the Tertiary.

Effects of carbendazim on DNA, gene and chromosome (살균제 carbendazim이 DNA, 유전자 및 염색체에 미치는 영향)

  • Lee, Je-Bong;Sung, Pil-Nam;Jeong, Mi-Hye;Shin, Jin-Sup;Kang, Kyu-Young
    • The Korean Journal of Pesticide Science
    • /
    • v.8 no.4
    • /
    • pp.288-298
    • /
    • 2004
  • Benzimidazole pesticide carbendazim that is effective against a wide range of fungal plant pathogens is a protective, eradicant, and systemic fungicide. For genetic toxicity evaluation of carbendazim on DNA, genes and chromosome, were investigated with chromosome aberration, bacterial reverse mutation, micronucleus test in mouse born marrow and DNA damage assay by single cell microgel electrophoresis. Substitution and frameshift mutation were not induce at variable concentration of carbendazim on Ames test with or without rat liver microsomal activation. For the result of chromosome aberration test, numerical changes of chromosome were detected at the concentrations higher than $4.0{\mu}g/m{\ell}$, but structural aberration was not induced. Positive control, Mitomycin-C and captafol made a structural aberration, but numerical change of chromosome did not appear. In the micronucleus test for mouse born marrow, carbendazim was negative, but was weak positive in DNA damage assay by single cell microgel electrophoresis because of increased DNA moving length of 20% to control.

Evaluation of Antioxidant Capacity and Antimutagen Activity of Bulbil Extracts of the Dioscorea japonica Decaisne and Dioscorea batatas Decaisne (단마와 장마 영여자의 항산화능 및 항돌연변이 활성 검정)

  • Park, Jeong-Seob;Lee, Jung-Ho;Bang, Keuk-Soo
    • Korean Journal of Plant Resources
    • /
    • v.25 no.2
    • /
    • pp.200-208
    • /
    • 2012
  • The bulbil of the $Dioscorea$ $species$ is produced, the amount of which is 2,000 tons annually, but it has been discarded without specific use. In this study the antioxidant and antimutagenicity of bulbil of the $Dioscorea$, which compared to bulbil of Danma($Dioscorea$ $japonica$ Decaisne) and Jangma($Dioscorea$ $batatas$ Decaisne), a major domestic cultivation species. The study was done by extracting bulbil of the Dioscorea methanol and the methanol extracts was re-extracted with chloroform, ethyl acetate, $n$-butanol and water. In methanol extract of Danma and Jangma, polyphenolic compounds contained 2.2 and 3.9 mg/g extract, respectively. The ethyl acetate fraction of Danma and Jangma had higher polyphenolic contents of 33.9 and 39.1 mg/g, whereas water fractions were much lower at 2.4 and 5.8 mg/g. Determination of antioxidant activity showed that the ethylacetate fraction strong DPPH radical scavenging activity and ABTS radical scavenging activity. The inhibitory effects of methanol extracts and chloroform, ethylacetate, $n$-butanol, water fraction from bulbil of Danma and Jangma on the mutagenicity in 1-NP, $AFB_1$, Trp-P-1 were investigated using $S.$ $typhimurium$ TA98. Danma and Jangma cultivars decreased the reverse mutation induced by 1-NP, $AFB_1$, Trp-P-1 in $S.$ $typhimurium$ TA98. The fraction of chloroform and ethylacetate showed strong inhibitory effects, in a dose dependant manner against the mutagenicities induced by 1-NP, $AFB_1$, Trp-P-1 in $S.$ $typhimurium$ TA98.

Agaricus blazei Mycelial Liquid Culture Extract Containing Eritadenine Improves Benign Prostatic Hyperplasia-related Biochemical Markers in RWPE-1 Cells through Anti-inflammatory and Anti-oxidative Actions (RWPE-1 전립선세포에서 eritadenine을 함유한 신령버섯균사체 액체배양물의 항염증효과 및 항산화효과에 의한 전립선비대증 관련 biochemical marker 개선 효과)

  • Ha, Yeong Lae;Moon, Yun-Gu;Kim, Na-Hyun;Heo, Jeong Doo;Cho, Min Jung;Kim, Ye Ra;Kim, Young Suk;Kim, Jeong OK
    • Journal of Life Science
    • /
    • v.28 no.10
    • /
    • pp.1147-1155
    • /
    • 2018
  • Agaricus blazei mycelial liquid culture extract (ABMLCE) promoted the production of testosterone (TS) in TM-3 mouse Leydig testis cells. Now, we report that ABMLCE containing eritadenine (EA) as a minor constituent (15.3 mg/100 g) reduced $5{\alpha}-reductase$ 2 ($5{\alpha}-R2$) enzyme activity and dihydrotestosterone (DHT) content which are key constituents for the benign prostatic hyperplasia (BPH) inductions. RWPE-1 prostate cells were grown in a Keratinocyte serum-free medium (K-SFM) containing ABMLCE (0~50 ppm), EA (0~10 ppm,), and finasteride (FS $10{\mu}M$: a positive control) in a 24-well plate for 24 hr. Supernatants collected from cell-cultured media were used for the assay of $5{\alpha}-R2$, superoxide dismutase (SOD), catalase (CAT) and cyclooxygenase-2 (COX-2) enzyme activities, and for TS, DHT, tumor necrosis $factor-{\alpha}$ ($TNF-{\alpha}$) and $interleukin-1{\beta}$ ($IL-1{\beta}$) contents by their assay kits. The $5{\alpha}-R2$ activity and DHT content were proportionally reduced (p<0.05) to concentrations of ABMLCE. The SOD and CAT enzyme activities were significantly (p<0.05) elevated concomitant with ABMLCE concentrations, while COX-2, $TNF-{\alpha}$ and $IL-1{\beta}$ showed reverse results (p<0.05). Similarly, the effects of EA were similar to those of ABMLCE. Efficacies of ABMLCE 50 ppm and EA 10 ppm in $5{\alpha}-R2$ and DHT reduction were similar to those of $10{\mu}M$ FS. These results suggest that ABMLCE and EA reduced $5{\alpha}-R2$ and DHT through their anti-inflammatory and anti-oxidative actions. This implies that ABMLCE containing EA could be a beneficial material in the cure of BPH in humans.

A Study on the Excavated Sab(a funeral fan) from Lime-filled Tomb and Lime-layered Tomb during the Joseon Dynasty (조선시대 회격·회곽묘 출토 삽(翣)에 대한 고찰)

  • Yi, Seung Hae;An, Bo Yeon
    • Korean Journal of Heritage: History & Science
    • /
    • v.41 no.2
    • /
    • pp.43-59
    • /
    • 2008
  • Sap(?, a funeral fan) is a funeral ceremonial object used in association with a Confucian ceremonial custom, which was crafted by making a wooden frame, attaching a white cloth or a thick paper onto it, drawing pictures on it, and making a holder for a handle. According to Liji(Records of Rites), Sap was used since the Zhou Dynasty, and these Chinese Sap examples are no big different than the Korean Sap examples, which were described in Joseon Wangjo Sillok(Annals of the Joseon Dynasty), Gukjo Oryeui(the Five Rites of the State), and Sarye Pyeollam(Handbook on Four Rituals). This study explored Sap excavated in lime-filled tombs and lime-layered tombs of aristocrats dating back to Joseon, as well as their historical records to examine Sap's characteristics according to their examples, manufacturing methods, and use time. The number and designs of Sap varied according to the deceased' social status aristocrats used mainly one pair of 亞-shaped Bulsap, and a pair of Hwasap with a cloud design depicted on it. A Sap was wrapped twice with Chojuji paper or Jeojuji paper, and for the third time with Yeonchangji paper. Then, it was covered with a white ramie, a hemp, a cotton, a silk satin, etc. Bobul(an axe shape and 亞-shape design) was drawn on both sides of Sap, and a rising current of cloud was drawn at the peripheral area mainly with red or scarlet pigments. Sap, which were excavated from aristocrats'lime-filled and lime-layered tombs, are the type of Sap which were separated from its handle. These excavated Sap are those whose long handles were burnt during the death carriage procession, leaving Sap, which later were erected on both sides of the coffin. The manufacturing process of excavated relics can be inferred by examining them. The excavated relics are classified into those with three points and those with two points according to the number of point. Of the three-point type(Type I), there is the kind of relic that was woven into something like a basket by using a whole wood plate or cutting bamboo into flat shapes. The three-point Sap was concentrated comparatively in the early half of Joseon, and was manufactured with various methods compared with its rather unified overall shape. In the meantime, the two-point Sap was manufactured with a relatively formatted method; its body was manufactured in the form of a rectangle or a reverse trapezoid, and then its upper parts with two points hanging from them were connected, and the top surface was made into a curve(Type II) or a straight line(Type III) differentiating it from the three-point type. This manufacturing method, compared with that of the three-point type, is simple, but is not greatly different from the three-point type manufacturing method. In particular, the method of crafting the top surface into a straight line has been used until today. Of the examined 30 Sap examples, those whose production years were made known from the buried persons'death years inscribed on the tomb stones, were reexamined, indicating that type I was concentrated in the first half of the $16^{th}$ century. Type II spanned from the second half of the $16^{th}$ century to the second half of the $17^{th}$ century, and type III spanned from the first half of the $17^{th}$ century to the first half of the $18^{th}$ century. The shape of Sap is deemed to have changed from type I to type II and again from type II to type III In the $17^{th}$ century, which was a time of change, types II and III coexisted. Of the three types of Sap, types II and III re similar because they have two points; thus a noteworthy transit time is thought to have been the middle of the $16^{th}$ century. Type I compared with types II and III is thought to have required more efforts and skills in the production process, and as time passed, the shape and manufacturing methods of Sap are presumed to have been further simplified according to the principle of economy. The simplification of funeral ceremonies is presumed to have been furthered after Imjinwaeran(Japanese invasion of Joseon, 1592~1598), given that as shown in the Annals of King Seonjo, state funerals were suspended several times. In the case of Sap, simplification began from the second half of the $16^{th}$ century, and even in the $18^{th}$ century, rather than separately crafting Sap, Sap was directly drawn on the coffin cover and the coffin. However, in this simplification of form, regulations on the use of Sap specified in Liji were observed, and thus the ceremony was rationally simplified.