• Title/Summary/Keyword: Layer Thickness

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GAMETOGENESIS AND REPRODUCTIVE CYCLE OF THE TOPSHELL, TURBO CORNUTUS SOLANDER (소라, Turbo cornutus의 생식세포형성과정 및 생식주기에 관한 조직학적 연구)

  • LEE Ju Ha
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.13 no.4
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    • pp.125-134
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    • 1980
  • The dovelopment of the gonads, gametogenesis and the reproductive cycle of the topshell, Turbo cornutus Solander, which is one of valuable food animals fom Korean waters were studied by photomicroscophy. The materials were monthly collected from Bangeojin, Jeongjari and Dangweol, all these places being located in the south-eastern part of Korea, for one year from March 1979 to February 1980. Topshell is dioecious and oviparous. Gonad is situated on the surface of liver, which lies posteriorly. The surface of ovary and testis is covered with a fibrous membrane, membrane of connective and muscular fibers and then an outermost layer of simple-columnar epithelial cells which are composed of cuboidal and columnar mucous gland cells. Primordial germ cells develop on the germinal epithelium of ovarian and testicular lobuli which are originated from the fibrous membrane and extend toward hepatic gland. Undifferentiated mesenchymal tissue and pigment granular cells are abundantly distributed between the growing oocytes and spermatocytes in the early development stages. With the further development of the ovary and testis these tissue and cells gradually disappear. Then the undifferentiated mesenchymal tissue and pigment granular cells are considered to be related to the growing of the oocytes and spermatocytes. Early multiplicating oogonium is ca. 10μ in diameter and nucleushaving a central nucleolus is ra. 8μ. As the oocytea grow to ca. 5060μ by the increase of cytoplasm, the oocytes become look like bunches of grapes which are attached to ovarian lobuli. Mature eggs are ca. 180210μ in diameter and it is surrounded by a gelatinous membrane of ca. 10μ in thickness. After spawning, undischarged ripe eggs and spermatozoa remain in the ovary and testis respectively for some time. Then they finally degenerate, and proliferation of new oogonia and spermatogonia occur along the germinal epithelia of newly developed ovarian and testicular lobuli. Reprocuctive cycle of Turbo cornutus could be classified into five successive stages: multiplicative, growing, maturer spent and recovery stages. Spawning occurs from August to November with Peak spawning from early September to late October.

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Effect of the Application of a Suspended and a Mixing-in-Pipe Type Aerator on the Liquid Fertilization of Pig Manure Slurry (현수, 배관 내 혼합 폭기방식 적용이 돼지분뇨 슬러리의 액상 비료화에 미치는 영향)

  • Jeong, Kwang Hwa;Kim, Jung-Kon;Khan, Modabber Ahmed;Kwag, Jung-Hoon;Han, Duk-Woo
    • Journal of the Korea Organic Resources Recycling Association
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    • v.22 no.4
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    • pp.62-71
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    • 2014
  • Three types of diffuser systems were manufactured and applied to investigate the effect of liquid fertilization of pig manure slurry by application of aeration processes. In the first type reactor, commonly used diffuser system, which diffuse air upward by diffusing aerator fixed at the bottom of the reactor is installed. In case of the second type, air diffuser is installed 10 cm above of the bottom of a reactor. In the third type reactor, the venturi-type air diffuser is installed at circulation pipe, which return pig slurry in the reactor(mixing-in-pipe process). The pig manure slurry separated to solid/liquid was flowed into the experimental reactor, and left as it for one week to precipitate solids. The concentration of organic matter, T-N, T-P and BOD in the raw pig manure slurry flowed into the reactor of bottom-fixed type aeration process were 1.82%, 4,400 mg/L, 360 mg/L and 13,542 mg/L, respectively. After aeration the concentration of organic matters, T-N, T-P and BOD in the slurry were 2.01%, 4,400 mg/L, 420 mg/L and 16,824 mg/L, respectively. The concentration of organic matter, T-N, T-P and BOD in the mixing-in-pipe type changed from 1.58%, 3,700 mg/L, 260 mg/L and 15,735 mg/L to 1.96%, 4,000 mg/L, 340 mg/L, and 18,098 mg/L, respectively. Changes of the concentration of organic matter, T-N, T-P and BOD of the pig manure slurry collected from the middle layers of two aeration reactors; bottom aeration process and the mixing-in-pipe process, were 10.4%, 0%, 16.7% and 24.2% and 24.0%, 8.1%, 30.8% and 15.0%, respectively. The thickness of foam layer generated on the surface of pig manure slurry in aeration tank was thinner in mixing-in-pipe reactor than bottom-fixed type aeration reactor.

The Effect of Bee Venom Therapy on Skin Aging (봉독이 피부 노화에 미치는 영향)

  • Kim, Jin-Myoung;Kim, Yoon-Bum
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.23 no.2
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    • pp.27-40
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    • 2010
  • Background and Objective : Increasing interest in anti-aging and anti-wrinkling agents for the skin has triggered the recent outflow of researches and studies in this field. This study was designed to investigate the effects of bee venom on skin wrinkling and skin aging by testing the skin wrinkling, skin elasticity, trans-epidermal water loss (TEWL), free radical level, anti-oxidative agent level, and skin tissue after infusion of bee venom on hairless mouse. Materials and Methods : Fifteen hairless mice aged between 36~40 weeks were divided randomly into 3 Group; the Bee Venom Syringe Group, the Bee Venom Needle Group, and the control group. The Bee Venom Syringe Group were injected subcutaneously with bee venom (0.1cc in total) using an insulin syringe on three spots in the lumbar spine (one spot on the center and two spots 1~2cm to the side bilaterally). The Bee Venom Needle Group were pricked with bee venom-smeared acupuncture needles on three longitudinal spots in the lumbar spine each 1cm apart, after which the needles were removed 10 minutes later. The Control Group did not receive any form of intervention. All procedures took place thrice a week for four weeks, during which the mice were allowed free access to water and fodder. The mice were measured and compared in the weight, skin wrinkling scale, skin elasticity, and TEWL before and after the experiment. After the experiment, blood samples were taken to measure the free radical and anti-oxidative agent level, and the skin tissue was sliced for examination. Data was analyzed using the SPSS program (ver 12.0). The ANOVA analysis was used to compare and contrast the three groups, and t-test for paired samples was used to evaluate skin-wrinkling before and after experiment. The cut-off p-value of significance was set at p<0.05. Results : 1. Administration of bee venom did not cause serious weight loss or gain. 2. Compared to the control group, the Bee Venom Syringe Group and the Bee Venom Needle Group both showed a decrease in skin wrinkling scale after intervention. Especially, the Bee Venom Syringe Group showed a significant decrease (p<0.05). 3. Compared to the control group, the Bee Venom Syringe Group and the Bee Venom Needle Group both showed an increase in skin elasticity. Especially, the Bee Venom Syringe Group showed a significant increase (p<0.05). 4. No significant change in TEWL was found in the mice in all the three groups before and after experiment. 5. Free radical level was normal in all 15 mice in all the three groups, and anti-oxidative agent was not significantly different across the three groups. 6. The Bee Venom Syringe Group, the Bee Venom Needle Group, and the control group did not show any significant difference in the thickness of epidermis and dermis, infiltration of inflammatory cells, and skin wrinkling. The epidermis layer was relatively better preserved in the Bee Venom Syringe Group as compared to the Bee Venom Needle Group and the control group. Conclusion : Direct injection of bee venom on the hairless mouse using a syringe was found to improve wrinkling of the skin and increase skin elasticity but did not show effectiveness on skin dryness due to water loss. The bee venom appears to have suppressive effects on skin wrinkling, one of the symptoms of skin aging, through a process independent of suppression of free radicals or increase of anti-oxidative agent.

Growth Characters and Their Seasonal Changes in Bupleurum falcatum L. Cultivars, 'Jeongsun' and 'Mishima' (재배종 시호의 생육특성 및 생육시기별 변화)

  • Kim, Kwan-Su;Chae, Young-Am;Lee, Bong-Ho
    • Korean Journal of Medicinal Crop Science
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    • v.8 no.3
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    • pp.234-242
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    • 2000
  • There are two cultivars, 'Jeongsun' and 'Mishima' of Bupleurum falcatum L., a medicinal plant, have been cultivated in Korea. Two cultivars were evaluated and compared in details for major growth characters and their seasonal changes. Jeongsun was higher in stem length and root weight per plant, and earlier in maturity than Mishima, while Mishima was higher in top weight per plant and the ratio of outer phloem layer(OPL) to whole root, and more in branch number. Coefficients of variations of most growth characters were higher in Mishima than in Jeongsun. In relationship between root and shoot growth characters, root weight, root diameter, etc. were positively correlated with stem thickness, top weight, branch number, etc. in both cultivars. In comparison of seasonal changes for growth characters between two cultivars, stem length and node number were almost not increased after September, but root length and branch number tended to increase until November. There were continuous increases of top and root weights in both cultivars after September. Increase rates of top and root weights were higher in Mishima and Jeongsun, respectively. The weight ratio of root part to whole plant in Jeongsun and the ratio of OPL to whole root in Mishima were higher during whole growth stages; especially Mishima showed their continuous increases after October. Jeongsun flowered earlier (August 17) than Mishima (September 16) by one month. Complete flowering date was on August 30 in Jeongsun and on September 30 in Mishima. Basic difference in plant growth between two cultivars was maturity, so shoot growth almost stopped after October in Jeongsun, and continued vegetative growth until November in Mishima with late flowering habit. These results indicate that higher root weight in Jeongsun is due to its earlier flowering character leading to relatively longer time for root growth, as compared with Mishima.

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Magnetic and Electric Transport Properties of MnTe Thin Film Grown by Molecular Beam Epitaxy (분자선 증착법에 의해 성장한 MnTe 박막의 자기적 및 전기수송 특성)

  • Kim, Woo-Chul;Bae, Sung-Whan;Kim, Sam-Jin;Kim, Chul-Sung;Kim, Kwang-Joo;Yoon, Jung-Bum;Jung, Myung-Hwa
    • Journal of the Korean Magnetics Society
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    • v.17 no.2
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    • pp.81-85
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    • 2007
  • MnTe layers of high crystalline quality were successfully grown on Si(100) : B and Si(111) substrates by molecular beam epitaxy (MBE). Under tellurium-rich condition and the substrate temperature around 400C, a layer thickness of 700\AA could be easily obtained with the growth rate of 1.1\AA/s. We investigated the structural, magnetic and transport properties of MnTe layers by using x-ray diffraction (XRD), superconducting quantum interference device (SQUID) magnetometry, and physical properties measurement system (PPMS). Characterization of MnTe layers on Si(100) : B and Si(111) substrates by XRD revealed a hexagonal structure of polycrystals with lattice parameters, α=4.143±0.001\AAandc=6.707±0.001\AA. Investigation of magnetic and transport properties of MnTe films showed anomalies unlike antiferromagnetic powder MnTe. The temperature dependence of the magnetization data taken in zero-field-tooling (ZFC) and field-cooling (FC) conditions indicates three magnetic transitions at around 21, 49, and 210 K as well as the great irreversibility between ZFC and FC magnetization in the films. These anomalies are attributable to a magnetic-elastic coupling in the films. Magnetization measurements indicate ferromagnetic behaviour with hysteresis loops at 5 and 300 K for MnTe polycrystalline film. The coercivity (Hc) values at 5 and 300 K are 55 and 44 Oe, respectively. In electro-transport measurements, the temperature dependence of resistivity revealed a noticeable semiconducting behaviours and showed conduction via Mott variable range hopping at low temperatures.

Site Characterization using Shear-Wave Velocities Inverted from Rayleigh-Wave Dispersion in Chuncheon, Korea (레일리파 분산을 역산하여 구한 횡파속도를 이용한 춘천시의 부지특성)

  • Jung, JinHoon;Kim, Ki Young
    • Geophysics and Geophysical Exploration
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    • v.17 no.1
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    • pp.1-10
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    • 2014
  • To reveal and classify site characteristics in densely populated areas in Chuncheon, Korea, Rayleigh-waves were recorded at 50 sites including four sites in the forest area using four 1-Hz velocity sensors and 24 4.5-Hz vertical geophones during the period of January 2011 to May 2013. Dispersion curves of the Rayleigh waves obtained by the extended spatial autocorrelation method were inverted to derive shear-wave velocity (vs) models comprising 40 horizontal layers of 1-m thickness. Depths to weathered rocks (Db), shear wave velocities of these basement rocks (vsb), average velocities of the overburden layer (v¯ss), and the average velocity to a depth of 30 m (vs30), were then derived from those models. The estimated values of Db, vsb, v¯ss, and vs30 for 46 sites at lower altitudes were in the ranges of 5 to 29 m, 404 to 561 m/s, 208 to 375 ms/s, and 226 to 583 m/s, respectively. According to the Korean building code for seismic design, the estimated vs30 indicates that the lower altitude areas in Chuncheon are classified as SC (very dense soil and soft rock) or SD (stiff soil). To determine adequate proxies for vs30, we compared the computed values with land cover, lithology, topographic slope, and surface elevation at each of the measurement sites. Due to a weak correlation (r = 0.41) between vs30 and elevation, the best proxy of them, applications of this proxy to Chuncheon of a relatively small area seem to be limited.

In Vitro Evaluation of Shear Bond Strengths of Zirconia Cerami with Various Types of Cement after Thermocycling on Bovine Dentin Surface (지르코니아 표면 처리와 시멘트 종류에 따른 치면과의 전단 결합 강도 비교 연구)

  • Cho, Soo-Hyun;Cho, In-Ho;Lee, Jong-Hyuk;Nam, Ki-Young;Kim, Jong-Bae;Hwang, Sang-Hee
    • Journal of Dental Rehabilitation and Applied Science
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    • v.23 no.3
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    • pp.249-257
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    • 2007
  • State of problem : The use of zirconium oxide all-ceramic material provides several advantages, including a high flexural strength(>1000MPa) and desirable optical properties, such as shading adaptation to the basic shades and a reduction in the layer thickness. Along with the strength of the materials, the cementation technique is also important to the clinical success of a restoration. Nevertheless, little information is available on the effect of different surface treatments on the bonding of zirconium high-crystalline ceramics and resin luting agents. Purpose : The aim of this study was to test the effects of surface treatments of zirconium on shear bond strengths between bovine teeth and a zirconia ceramic and evaluate differences among cements Material and methods : 54 sound bovine teeth extracted within a 1 months, were used. They were frozen in distilled water. These were rinsed by tap water to confirm that no granulation tissues have left. These were kept refrigerated at 4C until tested. Each tooth was placed horizontally at a plastic cylinder (diameter 20mm), and embedded in epoxy resin. Teeth were sectioned with diamond burs to expose dentin and grinded with #600 silicon carbide paper. To make sure there was no enamel left, each was observed under an optical microscope. 54 prefabricated zirconium oxide ceramic copings(Lava, 3M ESPE, USA) were assigned into 3 groups ; control, airborne-abraded with 110μm Al2O3 and scratched with diamond burs at 4 directions. They were cemented with a seating force of 10 ㎏ per tooth, using resin luting cement(Panavia F(R)), resin cement(Superbond C&B^{(R)}), and resin modified GI cement(Rely X Luting(R)). Those were thermocycled at 5C and 55C for 5000 cycles with a 30 second dwell time, and then shear bond strength was determined in a universal test machine(Model 4200, Instron Co., Canton, USA). The crosshead speed was 1 mm/min. The result was analyzed with one-way analysis of variance(ANOVA) and the Tukey test at a significance level of P<0.05. Results : Superbond C&B^{(R)} at scratching with diamond burs showed the highest shear bond strength than others (p<.05). For Panavia F(R), groups of scratching and sandblasting showed significantly higher shear bond strength than control group(p<.05). For Rely X Luting(R), only between scratching & control group, significantly different shear bond strength was observed(p<.05). Conclusion : Within the limitation of this study, Superbond C&B^{(R)} showed clinically acceptable shear bond between bovine teeth & zirconia ceramics regardless of surface treatments. For the surface treatment, scratching increased shear bond strength. Increase of shear bond strength by sandblasting with 110μm Al2O3 was not statistically different.

Effect of Dietary β-Cyclodextrin on Egg Quality and Cholesterol Content of Egg Yolks (난황 콜레스테롤 및 계란 품질에 관한 식이내 베타-사이클로덱스트린의 효과)

  • 박병성
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.33 no.4
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    • pp.614-620
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    • 2004
  • This study was to determine the effect of dietary β-cyclodextrin (βCD) on egg quality and cholesterol content of egg yolk. One-hundred 28-week-old laying hens were randomly distributed into five groups of twenty hens each and maintained in individual laying cages for 10 weeks of the experiment. They were assigned to the five treatments of experimental layer diets containing 0, 3, 5, 7 or 10% pure βCD of diets. Food intake, egg production and egg weight varied slightly and insignificantly in the hens fed with 0, 3, 5 or 7% βCD-added diets. But food intake, egg production, and egg weight were uniformly lower (p<0.05) in the hens fed with 10% βCD-added diets. Food conversion rate, when expressed per number egg, was impaired (p<0.05) without having an obvious relation to the dietary βCD level. No difference in haugh unit, egg yolk color, and egg shell thickness was found among treatment. The cholesterol content of egg yolks was significantly decreased (p<0.05) to 3.76, 5.12, 5.49 and 6.48 mg/g yolk in βCD 3, 5, 7 and 10% treatments respectively when compared to that of the βCD 0% group. The cholesterol content of eggs, when expressed in mg/60 g egg, was greatly (p<0.05) decreased to 54, 71, 77 and 86 mg in βCD 3, 5, 7 and 10% treatments when compared to that of the βCD 0% group. The most striking effects (p<0.05) were observed in βCD 5% and 7% treatments, whose cholesterol content decreased from 28.19% to 30.23%. In conclusion, βCD added-diets fed to laying hens can reduced the cholesterol content of egg yolk, and this new type of egg yolk with lower cholesterol can be considered a functional livestock food.

Application of Geophysical Methods to Detection of a Preferred Groundwater Flow Channel at a Pyrite Tailings Dam (황철석 광산 광미댐에서의 지하수흐름 경로탐지를 위한 물리탐사 적용)

  • Hwang, Hak Soo
    • Economic and Environmental Geology
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    • v.30 no.2
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    • pp.137-142
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    • 1997
  • At the tailings dam of the disused Brukunga pyrite mine in South Australia, reaction of groundwater with the tailings causes the formation and discharge of sulphuric acid. There is a need to improve remediation efforts by decreasing groundwater flow through the tailings dam. Geophysical methods have been investigated to determine whether they can be used to characterise variations in depth to watertable and map preferred groundwater flow paths. Three methods were used: transient electromagnetic (TEM) soundings, direct current (DC) soundings and profiling, and self potential (SP) profiling. The profiling methods were used to map the areal extent of a given response, while soundings was used to determine the variation in response with depth. The results of the geophysical surveys show that the voltages measured with SP profiling are small and it is hard to determine any preferred channels of groundwater flow from SP data alone. Results obtained from TEM and DC soundings, show that the DC method is useful for determining layer boundaries at shallow depths (less than about 10 m), while the TEM method can resolve deeper structures. Joint use of TEM and DC data gives a more complete and accurate geoelectric section. The TEM and DC measurements have enabled accurate determination of depth to groundwater. For soundings centred at piezometers, this depth is consistent with the measured watertable level in the corresponding piezometer. A map of the watertable level produced from all the TEM and DC soundings at the site shows that the shallowest level is at a depth of about 1 m, and occurs at the southeast of the site, while the deepest watertable level (about 17 m) occurs at the northwest part of the site. The results indicate that a possible source of groundwater occurs at the southeast area of the dam, and the aquifer thickness varies between 6 and 13 m. A map of the variation of resistivity of the aquifer has also been produced from the TEM and DC data. This map shows that the least resistive (i.e., most conductive) section of the aquifer occurs in the northeast of the site, while the most resistive part of the aquifer occurs in the southeast. These results are interpreted to indicate a source of fresh (resistive) groundwater in the southeast of the site, with a possible further source of conductive groundwater in the northeast.

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Evaluation of Hydrogeologic Seal Capacity of Mudstone in the Yeongil Group, Pohang Basin, Korea: Focusing on Mercury Intrusion Capillary Pressure Analysis (포항분지 영일층군 이암층의 수리지질학적 차폐능 평가: 수은 모세관 압입 시험의 결과 분석을 중심으로)

  • Kim, Seon-Ok;Wang, Sookyun;Lee, Minhee
    • Economic and Environmental Geology
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    • v.53 no.1
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    • pp.23-32
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    • 2020
  • Geological CO2 sequestration is a global warming response technology to limit atmospheric emissions by injecting CO2 captured on a large scale into deep geological formations. The presented results concern mineralogical and hydrogeological investigations (FE-SEM, XRD, XRF, and MICP) of mudstone samples from drilling cores of the Pohang basin, which is the research area for the first demonstration-scale CO2 storage project in Korea. They aim to identify the mineral properties of the mudstone constituting the caprock and to quantitatively evaluate the hydrogeologic sealing capacity that directly affects the stability and reliability of geological CO2 storage. Mineralogical analysis showed that the mudstone samples are mainly composed of quartz, K-feldspar, plagioclase and a small amount of pyrite, calcite, clay minerals, etc. Mercury intrusion capillary pressure analysis also showed that the samples generally had uniform particle configurations and pore distribution and there was no distinct correlation between the estimated porosity and air permeability. The allowable CO2 column heights based on the estimated pore-entry pressures and breakthrough pressures were found to be significantly higher than the thickness of the targeting CO2 injection layer. These results showed that the mudstone layers in the Yeongil group, Pohang basin, Korea have sufficient sealing capacity to suppress the leakage of CO2 injected during the demonstration-scale CO2 storage project. It should be noticed, however, that the applicability of results and analyses in this study is limited by the lack of available samples. For rigorous assessment of the sealing efficiency for geological CO2 storage operations, significant efforts on collection and multi-aspect evaluation for core samples over entire caprock formations should be accompanied.