• Title/Summary/Keyword: Blast method

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Engineering Properties of the Non-Cement Mortar using the Fly ash from Combined Heat Power Plant and Recycled Fine Aggregate (열병합발전소 플라이애시와 순환잔골재를 사용한 무시멘트 모르타르의 공학적 특성)

  • Nam, Han-Kook;Lim, Jeong-Geun;Lee, Sang-Soo
    • Journal of the Korea Institute of Building Construction
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    • v.15 no.6
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    • pp.553-559
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    • 2015
  • In this study, to suggest the application method of recycled fine aggregate, the non-cement mortar was prepared and studied with the binders of blast furnace slag, fly ash, and fly ash from combined heat power plant. As a basic experiment, a series of tests was conducted to determine the potions of the binders and types of activator. When the binder was consisted with 20% of fly ash and 40% of fly ash from combined heat power plant, the highest strength of the mortar was obtained, and as an activator, the combination of sodium hydroxide 2.5%, and calcium hydroxide 7.5% showed the highest strength of the mortar. Therefore, this study focuses on engineering properties of mortar contains fly ash from combined heat power plant and recycled fine aggregate according to replacement ratio of recycled fine aggregate based on the optimum mix from the basic experiment. As a result, the best replacement ratio of recycled fine aggregate is 75%.

An Availability Assessment of Protection Wall Installed in LPG Filling Station (LPG 충전소 내 설치된 방호벽의 효용성 평가)

  • Lee, Jin-Han;Jo, Young-Do;Moon, Jong-Sam;Kim, Lae Hyun
    • Journal of the Korean Institute of Gas
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    • v.22 no.5
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    • pp.38-45
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    • 2018
  • Jet fire, pool fire, and vapor cloud explosion are major accident scenarios in LPG filling station. The protection wall would mitigate radiation effect in a jet fire. In case of a pool fire, the protection wall would restrict expanding the pool area. The protection wall might both obstruct the dispersion of released vapor and protect blast overpressure in a vapor cloud explosion scenario. In this paper, An availability assessment method of the protection wall how much reduce damage to receptors is proposed. Additionally application cases are presented for the effectiveness of protection wall in the LPG filling station. The study shows that the protection wall can effectively reduce the death probabilities of receptors located behind the wall in cases of the jet fires and the vapor cloud explosions.

The retrospective study of survival rate of implants with maxillary sinus floor elevation (상악동 거상술을 동반한 임플란트 식립 후 생존율에 대한 후향적 연구)

  • Yu, Jeoung-A;Lee, Sang-Min;Yoo, Mi-Kyung;Jung, Ui-Won;Kim, Chang-Sung;Choi, Seong-Ho;Park, Pil-Kyoo;Cho, Kyoo-Sung
    • Journal of Periodontal and Implant Science
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    • v.39 no.3
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    • pp.293-301
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    • 2009
  • Purpose: The purpose of this study is to show the total survival rate of implants with maxillary sinus floor elevation and the effects that reach the survival rate by classifying types of graft materials, implant surface, operation method, bone height. Methods: In a total of 131 patients, 251 implants with sinus floor elevation were installed simultaneously or after regular healing. Various bone grafts (autograft, xonograft, allograft, alloplast) and implant surface (MTX-HA implant, chemical etching implant, Titanium oxide surface implant, resorbable blasting media implant, resorbable blast texturing implant, HA-coated implant) were used. All implants were investigated clinically and radiographically, being with 1 to 5 years follow-up period after installation. Results: The survival rate of 251 implants with maxillary sinus floor elevation was 94%. The types of implant, surface, graft material, bone height have no statistically signi-ficant differencies. Conclusions: It can be suggested that maxillary sinus floor elevation may have predictable result with various bone graft materials and implant surface.

Permeability Evaluation of OPC and GGBFS Concrete with Cold Joint (콜드조인트를 가진 OPC 및 GGBFS 콘크리트의 투수성 평가)

  • Choi, Se-Jin;Kim, Seong-Jun;Moon, Jin-Man;Kwon, Seung-Jun
    • Journal of the Korea Concrete Institute
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    • v.27 no.4
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    • pp.435-441
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    • 2015
  • Concrete, as a porous media, has permeability and it is considered as a major parameter for durability evaluation. Cold joint caused by delayed placing of concrete accelerates water permeation and intrusion of harmful ions. In the paper, concrete specimens containing GGBFS (Ground Granulated Blast Furnace Slag) and OPC (Ordinary Portland Cement) are prepared with cold joint section, and water permeability and water flow at the age of 91 days are measured for 2 weeks. Sound concrete with GGBFS shows decreased permeability to 89% for sound concrete with OPC and 0.86 of decreasing ratio is evaluated in GGBFS concrete with cold joint. Through WPT (Water Penetration Test), the effects of mineral admixture and cold joint on water permeability are evaluated, and variation in water behavior via cold joint is analyzed through probabilistic method as well.

Comparative Evaluation of Intron Prediction Methods and Detection of Plant Genome Annotation Using Intron Length Distributions

  • Yang, Long;Cho, Hwan-Gue
    • Genomics & Informatics
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    • v.10 no.1
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    • pp.58-64
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    • 2012
  • Intron prediction is an important problem of the constantly updated genome annotation. Using two model plant (rice and $Arabidopsis$) genomes, we compared two well-known intron prediction tools: the Blast-Like Alignment Tool (BLAT) and Sim4cc. The results showed that each of the tools had its own advantages and disadvantages. BLAT predicted more than 99% introns of whole genomic introns with a small number of false-positive introns. Sim4cc was successful at finding the correct introns with a false-negative rate of 1.02% to 4.85%, and it needed a longer run time than BLAT. Further, we evaluated the intron information of 10 complete plant genomes. As non-coding sequences, intron lengths are not limited by a triplet codon frame; so, intron lengths have three phases: a multiple of three bases (3n), a multiple of three bases plus one (3n + 1), and a multiple of three bases plus two (3n + 2). It was widely accepted that the percentages of the 3n, 3n + 1, and 3n + 2 introns were quite similar in genomes. Our studies showed that 80% (8/10) of species were similar in terms of the number of three phases. The percentages of 3n introns in $Ostreococcus$ $lucimarinus$ was excessive (47.7%), while in $Ostreococcus$ $tauri$, it was deficient (29.1%). This discrepancy could have been the result of errors in intron prediction. It is suggested that a three-phase evaluation is a fast and effective method of detecting intron annotation problems.

Screening of Differentially Expressed Genes by Desferrioxamine or Ferric Ammonium Citrate Treatment in HepG2 Cells

  • Park, Jong-Hwan;Lee, Hyun-Young;Roh, Soon-Chang;Kim, Hae-Yeong;Yang, Young-Mok
    • BMB Reports
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    • v.33 no.5
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    • pp.396-401
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    • 2000
  • A differential display method is used to identify novel genes whose expression is affected by treatment with ferric ammonium citrate (FAC) or desferrioxamine (DFO), an iron chelating agent in the human hepatoblastoma cell line (HepG2). These chemicals are known to deplete or increase the intracellular concentration of iron, respectively. Initially, we isolated seventeen genes whose expressions are down- or up regulated by the treatment of the chemicals, as well as their four differentially expressed genes that are designated as clone-1, -2, -3, and -4. These are further characterized by cDNA sequencing and Northern blot analysis. Through the cDNA sequencing, as well as comparing them to genes published using the NCBI BLAST program, we identified the sequence of the clone-1 that is up-regulated by the treatment of DFO. It is identical to the human insulin-like growth factor binding protein-1 (IGFBP-1). This suggests that the IGFBP-1 gene in the HepG2 cell is up-regulated by an iron depletion condition. Also, the expression of the clone-3 and -4 is up-regulated by FAC treatment and their eDNA sequences are identical to the human ferritin-fight chain and human NADH-dehydrogenase, respectively. However, the sequence of the clone-2 has no significant homology to any other known gene. Therefore, we suggest that changes of the cellular iron level in the HepG2 cell affects the transcription of cellular genes. This includes human IGFBP-1, ferritin-fight chain, and NADH-dehydrogenase. Regulation of these gene expressions may have an important role in cellular functions that are related to cellular iron metabolism.

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A Study on Safety Blasting Design with Blast Vibration Analysis Urban Area (도심지 미진동 제어 발파에서 진동분석을 통한 안전발파설계에 관한 연구)

  • 안명석;박종남;배상근
    • Explosives and Blasting
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    • v.17 no.2
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    • pp.36-44
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    • 1999
  • A study was made on the design of the prediction model concerning blasting vibration in a constraction site, Namgu, Daegu City. The geology in this area consists of hornfels of shale and mud underlain by quartize, of which the main strike of the geological structure is NW direction. Measurements were carried out on the top of the wall concrete water storage tank, which is burried in the ground earth. The attenuation due to the vertical wall of the concrete structure may be experted because of spherical divergency at the bottom corner of the wall by the Huygens principle. For design of blasting prediction model, thus among scaled distance(SD) may be preferable to use in the regression model, since they represents most likely the average ground condition. Judging from the regression results, the cube root method may be more suitable for this area. The SD values for the maximum allowable vibration velocity of 0.5 cm/s, in this area are 22.5, 28.0 and 30.6 for the significance level of 50%, 95% and 99%, respectively.

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Study on the Crack Generation Patterns with Change in the Geometry of Notches and Charge Conditions (노치 형상 및 장약조건의 변화에 따른 균열발생양상에 관한 연구)

  • Park, Seung-Hwan;Cho, Sang-Ho;Kim, Seung-Kon;Kim, Kwang-Yeom;Kim, Dong-Gyou
    • Tunnel and Underground Space
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    • v.20 no.1
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    • pp.65-72
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    • 2010
  • Crack-controlled blasting method which utilizes notched charge hole has been proposed in order to achieve smooth fracture plane and minimize the excavation damage zone. In this study, the blast models, which have a notched charge hole, were analyzed using dynamic fracture process analysis software to investigate the effect of the geometry of a notched charge hole and decoupling indexes of the charge hole on crack growth control in blasting. As a result, crack extension increased and damage crack decreased with the notch length. Ultimately, stress increment factors and resultant fracture patterns with different notch length and width were analyzed in order to examine the effect factors on the crack growth controlling in rock blasts using a notched charge hole.

Differentially Expressed Genes by Methylmercury in Neuroblastoma cell line using suppression subtractive hybridization (SSH) and cDNA Microarray

  • Kim, Youn-Jung;Chang, Suk-Tai;Yun, Hye-Jung;Ryu, Jae-Chun
    • Proceedings of the Korea Society of Environmental Toocicology Conference
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    • 2003.05a
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    • pp.187-187
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    • 2003
  • Methylmercury (MeHg), one of the heavy metal compounds, can cause severe damage to the central nervous system in humans. Many reports have shown that MeHg is poisonous to human body through contaminated foods and has released into the environment. Despite many studies on the pathogenesis of MeHg-induced central neuropathy, no useful mechanism of toxicity has been established so far. In this study, two methods, cDNA Microarray and SSH, were performed to assess the expression profile against MeHg and to identify differentially expressed genes by MeHg in neuroblastoma cell line. TwinChip Human-8K (Digital Genomics) was used with total RNA from SH-SY5Y (human neuroblastoma cell line) treated with solvent (DMSO) and 6.25 uM (IC50) MeHg. And we performed forward and reverse SSH method on mRNA derived from SH-SY5Y treated with DMSO and MeHg (6.25 uM). Differentially expressed cDNA clones were sequenced and were screened by dot blot and ribonuclease protection assay to confirm that individual clones indeed represent differentially expressed genes. These sequences were identified by BLAST homology search to known genes or expressed sequence tags (ESTs). Analysis of these sequences may provide an insight into the biological effects of MeHg in the pathogenesis of neurodegenerative disease and a possibility to develop more efficient and exact monitoring system of heavy metals as environmental pollutants.

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Predicting strength development of RMSM using ultrasonic pulse velocity and artificial neural network

  • Sheen, Nain Y.;Huang, Jeng L.;Le, Hien D.
    • Computers and Concrete
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    • v.12 no.6
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    • pp.785-802
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    • 2013
  • Ready-mixed soil material, known as a kind of controlled low-strength material, is a new way of soil cement combination. It can be used as backfill materials. In this paper, artificial neural network and nonlinear regression approach were applied to predict the compressive strength of ready-mixed soil material containing Portland cement, slag, sand, and soil in mixture. The data used for analyzing were obtained from our testing program. In the experiment, we carried out a mix design with three proportions of sand to soil (e.g., 6:4, 5:5, and 4:6). In addition, blast furnace slag partially replaced cement to improve workability, whereas the water-to-binder ratio was fixed. Testing was conducted on samples to estimate its engineering properties as per ASTM such as flowability, strength, and pulse velocity. Based on testing data, the empirical pulse velocity-strength correlation was established by regression method. Next, three topologies of neural network were developed to predict the strength, namely ANN-I, ANN-II, and ANN-III. The first two models are back-propagation feed-forward networks, and the other one is radial basis neural network. The results show that the compressive strength of ready-mixed soil material can be well-predicted from neural networks. Among all currently proposed neural network models, the ANN-I gives the best prediction because it is closest to the actual strength. Moreover, considering combination of pulse velocity and other factors, viz. curing time, and material contents in mixture, the proposed neural networks offer better evaluation than interpolated from pulse velocity only.