• Title/Summary/Keyword: stability evaluation

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Evaluation of Lead, Copper, Cadmium, and Mercury Species in the Leachate of Steel Making Slag by Seawater (해수에 의한 제강 슬래그의 납, 구리, 카드뮴 및 수은 화합물의 용출특성 평가)

  • Lee, Han-Kook;Lee, Dong-Hoon
    • Journal of Korean Society of Environmental Engineers
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    • v.27 no.1
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    • pp.75-84
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    • 2005
  • The aim of this study is to evaluate the leaching characteristics of lead, copper, cadmium, and mercury from steel making slag by seawater. To demonstrate the leaching characteristics of heavy metals from steel making slag by seawater, it was carried to various leaching tests such as regular leaching tests, liquid/sold(LS) leaching test and pH static test. From the leachability of $Pb^{+2},\;Cu^{+2},\;and\;Cd^{+2}$ from steel making slag in pH static test, it is distinguished between distilled water and seawater. With distilled water, it is very low between pH 7-8 and pH 11-12. On the other hands, with the seawater, its leaching is higher than that of distilled water. In particular, concentration of $Hg^{+2}$ leached from slag by seawater is lower than that of distilled water. Meanwhile, we found that the heavy metals from steel making slag would be dissolved and precipitated using geochemcial equilibrium program such as visual minteq. Lead and copper leached from steel making slag with seawater were dissolved nearly in the range of pH 11-12, but in the range of pH 7-10 those were precipitated about 90%. And cadmium leached from steel making slag with seawater were dissolved completely. On pH static test with distilled water, lead leached from steel making slag seemed to be similar to pH static test with seawater. However, copper and cadmium leached from steel making slag were dissolved. In general, the species of lead leached from steel making slag were formed mainly of $PbCl^+,\;PbSO_4$, the species of copper were formed mainly of $CuSO_4,\;CuCO_3$, the species of cadmium were formed mainly of $CdCl^+,\;CdSO_4$ due to being sorbed with the anions($Cl^-,\;CO_3^{-2},\;SO_4^{-2}$) of the seawater. Both pH static test with seawater and distilled water, it is not in the case of the mercury. Most of mercury leached from steel making slag was precipitated(SI=0). Because the decreasing of $Hg^{+2}$ concentrations depends ferociously on the variation of chloride($Cl^-$) existed in the seawater. $Hg^{+2}$ leached from steel making slag could be sorbed strongly with chloride($Cl^-$) compared of carbonate($CO_3^{-2}$) and sulfate($SO_4^{-2}$) in the seawater. On the basis of that result, we found that the species of mercury was formed of calomel($Hg_2Cl_2$) as one of finite solid. Due to forming a calomel($Hg_2Cl_2$) in the seawater, the stability of mercury species by steel making slag should be higher than those of lead, copper, and cadmium species. Regarding the results stated above, we postulated that the steel making slag could be recycled to sea aggregates due to being distinguishing leachability of heavy metals($Pb^{+2},\;Cu^{+2},\;Cd^{+2},\;and\;Hg^{+2}$) between leaching tests by distilled water and seawater.

Evaluation of the stress distribution in the external hexagon implant system with different hexagon height by FEM-3D (임플란트 hexagon 높이에 따른 임플란트와 주위 조직의 응력분포 평가)

  • Park, Seong-Jae;Kim, Joo-Hyeun;Kim, So-Yeun;Yun, Mi-Jung;Ko, Sok-Min;Huh, Jung-Bo
    • The Journal of Korean Academy of Prosthodontics
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    • v.50 no.1
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    • pp.36-43
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    • 2012
  • Purpose: To analyze the stress distribution of the implant and its supporting structures through 3D finite elements analysis for implants with different hexagon heights and to make the assessment of the mechanical stability and the effect of the elements. Materials and methods: Infinite elements modeling with CAD data was designed. The modeling was done as follows; an external connection type ${\phi}4.0mm{\times}11.5mm$ Osstem$^{(R)}$ USII (Osstem Co., Pusan, Korea) implant system was used, the implant was planted in the mandibular first molar region with appropriate prosthetic restoration, the hexagon (implant fixture's external connection) height of 0.0, 0.7, 1.2, and 1.5 mm were applied. ABAQUS 6.4 (ABAQUS, Inc., Providence, USA) was used to calculate the stress value. The force distribution via color distribution on each experimental group's implant fixture and titanium screw was studied based on the equivalent stress (von Mises stress). The maximum stress level of each element (crown, implant screw, implant fixture, cortical bone and cancellous bone) was compared. Results: The hexagonal height of the implant with external connection had an influence on the stress distribution of the fixture, screw and upper prosthesis and the surrounding supporting bone. As the hexagon height increased, the stress was well distributed and there was a decrease in the maximum stress value. If the height of the hexagon reached over 1.2mm, there was no significant influence on the stress distribution. Conclusion: For implants with external connections, a hexagon is vital for stress distribution. As the height of the hexagon increased, the more effective stress distribution was observed.

Changes in Characteristics of Bark and Piggery Manure By-Product Fertilizers During the Composting (수피${\cdot}$돈분 부산물 비료의 부숙단계별 특성 변화)

  • Yang, Jae-E;Park, Chang-Jin;Yong, Seok-Ho;Kim, Jeong-Je
    • Korean Journal of Environmental Agriculture
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    • v.18 no.4
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    • pp.372-377
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    • 1999
  • Objective of this research was to draw the basic criteria of the compost maturity evaluation, by assessing the stability of chemical and physical properties of the bark and piggery manure byproduct composts during the composting. Colors of the mature composts were black and dark brown for the bark and piggery manure by-product composts, respectively. Good earthy odor was detected for both by-product composts after approximately 40 days composting, by which odors of the original raw materials were disappeared. pH and EC of the mature bark: compost were stabilized at 6.5 and 1dS/m, respectively. The respective values for the piggery compost were stabilized at 7.2 and 6dS/m. Organic matter contents were decreased with time to be stabilized at about 60% at the end of composting. During composting, total N contents of the bark and piggery composts were maintained at $1.1{\sim}1.5%$, and $1.5{\sim}2.2%$, respectively. For both fertilizers, $NH_4-N$ contents were increased at the initial stage bur. decreased after the middle stages of decomposition, resulting in the increase of $NO_3-N$ contents. Total inorganic N contents were increased with time. C/N ratios of both mature composts were stabilized at $25{\sim}27$. CEC of the bark compost was increased logarithmically with time and that of mature compost was 87cmol(+)/㎏. CEC of the piggery manure compost was hyperbolic function with rime and reached at 70cmol(+)/㎏ at the mature stage. Crude fiber analysis indicated that relative contents of lignin were increased with composting by compensating for the decreases of cellulose and hemicellulose contents.

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Effect of Temperature and Relative Humidity on the Storage Stability of Boiled- Dried Anchovy (건멸치의 저장 안정성에 미치는 온도 및 습도의 영향)

  • Jo, Kil-Suk;Kim, Young-Myoung
    • Korean Journal of Food Science and Technology
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    • v.19 no.3
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    • pp.188-194
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    • 1987
  • Changes in some qualities of boiled-dried anchovy during storage at $-18^{\circ}C$, $-3^{\circ}C$, $5^{\circ}C$, $10^{\circ}C$ and room temperature for 12 months were studied. The monolayer moisture contents were 8.12% and 5.88% at $5^{\circ}C$ and $25^{\circ}C$, respectively. Volatile basic nitrogen (VBN) content was found to be higher at $5^{\circ}C$ and $-3^{\circ}C$ than those values at $10^{\circ}C$, $-18^{\circ}C$ and room temperature. Lipid oxidative browing and Hunter color values of L, a and b were remarkably developed with increase of storage temperature. Judging from organoleptic evaluation boiled-dried anchovy could be preserved in acceptable condition for $4{\sim}6\;months$ at room temperature, $5{\sim}8\;months$ at $10^{\circ}C$, $8{\sim}10\;months$ at $5^{\circ}C$ and 12 months at 7 below $-3^{\circ}C$. During storage at room temperature for 5 months after 7 months storage at $5^{\circ}C$ and $-18^{\circ}C$. VBN concept was increased by 1.03 and 1.38. browning rate by 1.03 and 2.15, and a and b values by $1.21{\sim}1.60 $and $1.02{\sim}2.80$ times in comparison with the basic room temperature, respectively.

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The Evaluation of Usefulness of Two Times Elution a Day of $^{99m}Tc$ Using $^{99}Mo$-$^{99m}Tc$ Generator ($^{99m}Tc$ 발생기의 24시간 내 2회 용출의 유용성 평가)

  • Kim, Jeong-Ho;Seo, Han-Kyung;Jeong, Yeong-Hwan;Kim, Yeong-Su;Kim, Byung-Cheol;Gwon, Yong-Ju;Lee, Jeong-Ok;Park, Yeong-Sun;Kim, Dong-Yun
    • The Korean Journal of Nuclear Medicine Technology
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    • v.14 no.2
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    • pp.83-86
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    • 2010
  • Purpose: The Molybdenum which is the raw material of $^{99}Mo$-$^{99m}Tc$ generator (generator) is produced from the nuclear reactor. However, output has dwindled as the two nuclear reactors supplying the bulk of radioactive material-one in Chalk River, Ontario and the other in Petten, the Netherlands-have been closed for repairs or maintenance. This resulted in the enhancement of its price. Therefore we have tried to seek the new method which could run generator to increase activity of $^{99m}Tc$ in this study. Materials and Methods: The $^{99m}Tc$ activity obtained from 5 times elution for 5 days from Monday to Friday using two generators was compared with 10 times elution. Appearance test, pH test, LAL test, sterility test, chemical impurity(Al) test, radio chemical purity test, ratio of $^{99}Mo$/$^{99m}Tc$ activity test have been done to check the stability of $^{99m}Tc$ eluting from generator respectively. Results: The $^{99m}Tc$ activity obtained from 5 times elution for 5 days was 168.2 GBq (4545 mCi) and 10 times was 230.5 GBq (6230 mCi). All quality control tests were within normal limit. Conclusion: We got to know that 2 times elution a day obtained more $^{99m}Tc$ activity than one time elution in this study.

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Clinical Evaluation of TightRope Cranial Cruciate Ligament Technique for Treatment of Cranial Cruciate Ligament Deficiency in Dogs (전방 십자인대 결손을 보이는 개에서 TightRope을 이용한 치료방법 평가)

  • Yoon, Hun-Young;Kim, Kyung-Hee;Jeong, Soon-Wuk
    • Journal of Veterinary Clinics
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    • v.29 no.6
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    • pp.455-459
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    • 2012
  • Nine dogs presented to the Veterinary Medical Teaching Hospital of Konkuk University and Woosung Animal Hospital with a history of pelvic limb lameness. On physical examination, 9 dogs all showed a consistent weight bearing lameness and mild muscle atrophy. There was cranial drawer sign with pain in 9 dogs. Mediolateral radiographic projection revealed cranial subluxation of the tibial tuberosity in a tibial compression view. The right and left stifle joints were affected in 7 dogs and 2 dogs respectively. TightRope cranial cruciate ligament (CCL) technique for treatment of CCL deficiency was performed. Polyester and nylon were used to stabilize the stifle in 3 dogs and 6 dogs respectively. Suture sizes were 0.8 mm (n = 2), 0.9 mm (n = 4), 1.1 mm (n = 2), and $1.1mm{\times}2$ strands (n = 1) in diameter. Mean (${\pm}SD$) surgical duration was $48.3{\pm}8.5$ minutes (range 35 to 60 minutes). Preoperative and postoperative mean (${\pm}SD$) cranial drawer signs were $8.6{\pm}1.6$ mm (rage 7 to 12 mm) and $1.2{\pm}1.0$ mm (rage 0 to 3 mm) respectively. Immediate postoperative radiographs of the affected limb revealed no evidence of cranial subluxation of the tibial tuberosity in a tibial compression view of 9 dogs. Normal limb function was regained in 8 dogs within 8 weeks postoperatively. A consistent weight bearing lameness resolved in all dogs after TightRope CCL technique, but reoccurred in one dog (case No. 6) 2 weeks after surgery. Cranial subluxation of the tibial tuberosity was identified in a tibial compression test. During the second surgery, breakage of surgical button was identified and a tibial wedge osteotomy was performed. Based on surgical time, complication, stifle stability, and functional recovery, the present study indicated that TightRope CCL technique is effective treatment for the dogs with CCL deficiency.

Characterization of Entomopathogenic Fungus from Trialeurodes vaporariorum and Evaluation as Insecticide (온실가루이 병원성 곰팡이의 특성 및 살충제 개발을 위한 평가)

  • Yoon, Hwi Gun;Shin, Tae Young;Yu, Mi Ra;Lee, Won Woo;Ko, Seung Hyun;Bae, Sung Min;Choi, Jae Bang;Woo, Soo Dong
    • Korean Journal of Microbiology
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    • v.49 no.1
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    • pp.64-70
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    • 2013
  • The greenhouse whitefly, Trialeurodes vaporariorum, is an economically important pest for greenhouse crops because they cause direct damage by feeding on plant nutrients and indirect damage as transmits many virus vectors. It has recently become a serious problem because of the continuous use of insecticide resulting in resistance among greenhouse whitefly population. To overcome these problems, in this study, the biological characteristics and virulence of an entomopathogenic fungus isolated from the cadaver of nymph greenhouse whitefly were investigated. Isolated fungus was identified as Isaria fumosorosea by morphological examinations and genetic identification using sequences of the ITS, ${\beta}$-tubulin, and EF1-${\alpha}$ regions. This fungus was named as I. fumosorosea SDTv and tested for the virulence against nymphs T. vaporariorum and the cold activity, the thermotolerance and the stability of UV-B irradiation on conidia. Mortality rate of greenhouse whitefly showed from 84 to 100% and the virulence increased with increasing conidial concentrations, $1{\times}10^5$ to $10^8$ conidia/ml. Conidia were stable at $35^{\circ}C$, 0.1 $J/cm^2$ of UV irradiation and germinated after 8 days at $4^{\circ}C$. Additionally, the activities of chitinases and proteases produced by I. fumosorosea SDTv were varied according to the medium. In conclusion, I. fumosorosea SDTv which showed high mortality rate against greenhouse whitefly will be used effectively in the integrated pest management programs against the greenhouse whitefly.

Precessing of Smoked Dried and Powdered, Sardine for Instant Soup (정어리 분말수우프의 가공)

  • Oh, Kwang-Soo;Chung, Bu-Kil;Kim, Myung-Chan;Sung, Nak-Ju;Lee, Eung-Ho
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.17 no.2
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    • pp.149-157
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    • 1988
  • This study was carried out to prepare the flavoring substance using sardine for instant soup, and to examine the taste compounds and storage stability of the product. In preparation of product, raw sardine are gutted, boiled for 10 minutes and smoked 3 times to $9{\sim}10%$ moisture content at $80^{\circ}C$ for 8 hours. The smoked-dried sardine meat were followed to be 50 mesh of particle size. The powdered-dried sardine were mixed 4.0% sugar, 20.0% table salt, 3.0% monosodium glutamate, 0.2% black pepper, 0.2% garlic powder and 0.2% onion powder, Finally the powdered instant soup product were vacuum packed in a laminated film(PET/A1 foil/CPP) bag, and then stored at room temperature for 120 days. The effect of smoking on enhancing flavor and on preventing lipid oxidation of product during storage were observed. From the chemical analysis and omission test, the principal taste compounds of product were IMP, 478.2mg/l00g; free amino acids such as glutamic acid, histidine, arginine, phenylalaine 3292.5mg/l00g; non-volatile organic acids such as lactic acid, ${\alpha}-ketoglutaric$ acid, 712.2mg/l00g; total creatinine 409.0mg/100g, and small amount of betaine, TMAO. Fatty acid composition of product were mainly consisted of polyenoic acids such as 20:5, 22:6, followed by saturated acids, monoenoic acid. The major fatty acid were 16:0, 16:1, 18:1, 20:5 and 22:6. From the results of sensory evaluation and chemical experiments during storage, the vacuum packed product were good condition for preserving the quality during storage for 120 days. We may conclude that the quality of present product was not inferior to that of seasoning powder of anchovy on the market, and it can be commercialized as a flavoring substance in preparing soup and broth.

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The Effects of Addition of Agar on the Texture Characteristics (한천을 이용한 복숭아 젤리의 질감 특성과 기호도)

  • 박금순;조재욱
    • The Korean Journal of Food And Nutrition
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    • v.11 no.1
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    • pp.61-67
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    • 1998
  • Effects of various jelly prepared with different concentrations of agar and sugars on overall acceptability of the peach jelly were investigated. The preparations of peach for experimental jelly were carried by the mixture of peach pulp and juice(MPJ), and the extract form peach(EP). The results were summarized as follows ; 1. The pH for MPJ and EP were 3.95 to 4/31, respectively, and the brix degree were 13.0% and 11.5%, respectively. 2. The jelly prepared with MPJ added 3% agar and 30% sugar were most effective in appearance, hardness, springiness and overall acceptability. The relation of samples(P<0.001) was found to be significant. On the other hand, the jelly prepared with EP was higher scored than that with MPJ in overall acceptability, but there was no significant differences between samples. 3. The Hunter values of L*, a* and b* were the highest in both the jelly prepared with MPJ and that with EP, added 2% agar and 10% sugar. However, the L*, a* and b* values of the jelly added MPJ were higher than those of the sample added EP. 4. Texture and color scores of both the jelly added EP became higher as the concentrations of agar and sugars increased and there was significant differences between samples. 5. The relation between springiness and overall acceptability, and L* value of the jelly added MPJ showed negative at P<0.05 and that between springiness and overall acceptability of the jelly added EP also showed negative.

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Comparative Medium Term Results of Arthroscopic ACL Reconstruction with Quadrupled Semitendinosus Tendon versus BPB tendon (4겹의 반건양건과 골-슬개건-골을 이용한 관절경적 전방 십자 인대 재건술의 중기적 치료 결과 비교)

  • Kim, Hyoung-Soo;Park, Seung-Rim;Kang, Joon-Soon;Lee, Woo-Hyeong;Kim, Ki-Wook
    • Journal of the Korean Arthroscopy Society
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    • v.5 no.1
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    • pp.1-6
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    • 2001
  • Purpose : The purpose of this study was to compare the postoperative success and stability of arthroscopically assisted anterior cruciate ligament(ACL) reconstructions using central one third bone-patellar-tendon bone(BPB) autograft versus quadrupled semitendinos-us(ST) autograft as the medium term review. Materials and Methods : Eighty patients(40 BPBs,40 STs) with isolated ACL injury were available for a mean follow up of 49.4 months(BPB) and 48.8 months(ST). There was no significant difference between the two groups with respect to age and sex. We compare the final results between two groups with respect to subjective Lysholm score, objective laxity including anterior drawer test, Lachman test, pivot shift test, KT-2000 measurements and International Knee Documentation Committee(IKDC) evaluation system. Results : Postoperatively, positive anterior drawer test was found in $22.5\%\;and\;27.5\%$, positive Lachman test was found in $30.0\%$ and $25.0\%$ and positive pivot shift test was found in $15\%\;and\;20\%$ of the ST and BPB group, respectively(p>0.05). Mean side to side difference of KT-2000 at 20 lbs was 2.2 mm for the ST group and 2.1 mm for the BPB group. There was no significant difference between the two groups about Lysholm score(>0.05). Anterior knee pain was knee common in the BPB group. Eighty-three percent of the patients were nearly normal according to the IKDC grade in both groups. Conclusion : We consider that autogenous semitendinosus tendon is a good alternative subsititute in ACL reconstruction together with the bone-patellar tendon-bone autograft.

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