• Title/Summary/Keyword: CSA

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Use of Conformational Space Annealing in Molecular Docking

  • Lee, Kyoung-Rim;Czaplewski, Cezary;Kim, Seung-Yeon;Lee, Joo-Young
    • Proceedings of the Korean Society for Bioinformatics Conference
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    • 2004.11a
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    • pp.221-233
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    • 2004
  • Molecular docking falls into the general category of global optimization problems since its main purpose is to find the most stable complex consisting of a receptor and its ligand. Conformational space annealing (CSA), a powerful global optimization method, is incorporated with the Tinker molecular modeling package to perform molecular docking simulations of six receptor-ligand complexes (3PTB, 1ULB, 2CPP, 1STP, 3CPA and 1PPH) from the Protein Data Bank. In parallel, Monte Carlo with minimization (MCM) method is also incorporated into the Tinker package for comparison. The energy function, consisting of electrostatic interactions, van der Waals interactions and torsional energy terms, is calculated using the AMBER94 all-atom empirical force field. Rigid docking simulations for all six complexes and flexible docking simulations for three complexes (1STP, 3CPA and 1PPH) are carried out using the CSA and the MCM methods. The simulation results show that the docking procedures using the CSA method generally find the most stable complexes as well as the native -like complexes more efficiently and accurately than those using the MCM, demonstrating that CSA is a promising search method for molecular docking problems.

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Effects of Admixtures in Properties of Polymer Cement Mortar for Concrete Repair (혼화재료가 보수용 폴리머 시멘트 모르타르의 성질에 미치는 영향)

  • Song, Hyung-Soo;Lee, Chin-Yong;Min, Chang-Shik
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.11 no.1
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    • pp.85-94
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    • 2007
  • The EVA polymer is used as a modifier in the repair mortar, which contains various admixtures and mineral admixtures. It has been reported that the effect of polymer in cement mortar by the cement-polymer ratio only, but effect of admixtures over the polymer mortar was unknown. In this study, the fresh and mechanical properties of polymer cement mortar influenced by the range of admixtures(CSA expansive addictive, CSA accelerator, gypsum, silica fume) ratio were investigated.

Physicochemical properties and autogenous healing performance of ternary blended binders composed of OPC-BFS-CSA clinker

  • H.N. Yoon;Joonho Seo;Naru Kim;H.M. Son;H.K. Lee
    • Advances in concrete construction
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    • v.15 no.1
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    • pp.11-22
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    • 2023
  • Autogenous healing of concrete can be helpful in structural maintenance by healing cracks using a healing material created by the precipitation of calcite and by the hydration of unhydrated binder around the cracks. Against this backdrop, this study investigated the physicochemical properties and autogenous healing performance of ternary blended binder composed of ordinary Portland cement (OPC), blast furnace slag (BFS), and calcium sulfoaluminate (CSA) clinker. Ternary blended binders with various contents of OPC-BFS-CSA clinker were prepared, and their physicochemical properties and autogenous healing performances were examined using various analytical techniques and visually observed using a microscope. The obtained results indicated that increase in the BFS content accompanied the increased the amount of unreacted BFS even after 28 days of curing and had a positive effect on the autogenous healing performance due to its latent hydration. However, replacing the CSA clinker did not increase the autogenous healing performance owing to an insufficient sulfate source for the formation of ettringite. The main precipitates around the cracks were calcite, C-S-H. Other hydration products such as portlandite, monosulfate, and ettringite, which were not found in the Raman and scanning electron microscope analyses.

Evaluation of Stability of CLC through Strength and Reduction of Drying Shrinkage (강도 및 건조수축 저감을 통한 CLC의 안정성 평가)

  • Lee, Chang-Woo;Hwang, Woo-Jun;Lee, Sang-Soo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2022.11a
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    • pp.205-206
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    • 2022
  • This study intends to conduct tests on subsidence and drying shrinkage by mixing CaO-CSA expansion materials to ensure the stability of CLC, and to understand its properties. Based on CLC of 0.6, the replacement ratio of CaO-CSA expansion material was conducted at five levels compared to blast furnace slag, and the results are as follows. The replacement of CaO-CSA expansion material at an appropriate level produces ethringhite and potassium hydroxide, and it is believed that the internal voids of CLC and the Tobelmorite interlayer structure are charged to increase the structural stability, leading to an increase in compressive strength and a decrease in the drying shrinkage. However, it is judged that tissue relaxation due to excessive substances in the high replacement ratio affects the stability of CLC. In the future, we will conduct additional experiments on density, absorption rate, flow test, and settlement, and evaluate and analyze the stability of CLC by selecting the optimal replacement ratio of CaO-CSA expansion materials.

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Correlations of Cross-sectional Areas of Psoas and Paraspinal Muscles in Patients with Lumbar Disc Herniation According to the Age Groups (연령대별 요추 추간판탈출증 환자의 요근과 척추주위근 단면적에 대한 분석)

  • Kong, Deok-Hyun;Bae, Kwang-Ho;Go, Ho-Yeon;Kang, Myung-Jin;Kim, Jun-Su;Yang, Kee-Young;Lee, Jae-Hoon;Eun, Young-Jun
    • Journal of Korean Medicine Rehabilitation
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    • v.20 no.4
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    • pp.159-169
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    • 2010
  • Objectives : This study was designed to evaluate the correlation of the cross-sectional areas(CSA) of paraspinalis(iliocostalis lumborum, multifidus, longissimus thoracis parts lumborum) and psoas muscle and sex, age, change of the VAS(visual analogue scale) and past history of chronic low back pain in patients suffering from HIVD(herniation of intervertebral disc). Methods : Medical records of 140 subjects with HIVD were retrospectively reviewed. The MRI(magnetic resonance imaging) findings on the patients were scanned and analyzed by PiView program to find the paraspinal and psoas muscle CSA and were evaluated by the correlation of sex, age, change of the VAS, and past history of chronic low back pain. Results : There was significant difference between groups in male and female, young-adults age and middle age, middle age and old age, young-adults age and old age. But the correlation of the paraspinal and psoas muscle CSA and past history of chronic low back pain were partially significant. On the other hand, the correlation of the paraspinal and psoas muscle CSA and change of the VAS were not significant. Conclusions : These results suggest that the cross-sectional areas(CSA) of paraspinalis and psoas muscle have relevance to sex and age.

Experimental Study of Laser Assisted Microvascular Anastomosis(LAMA) Using the Nd:YAG Contact Laser (Laser를 이용한 새로운 미세혈관 문합술의 실험적 연구)

  • Cho, Jin-Hwan;Lim, Jae-Ho;Park, Seung-Ha;Kim, Woo-Kyung
    • Archives of Reconstructive Microsurgery
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    • v.2 no.1
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    • pp.82-92
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    • 1993
  • A comparative study was undertaken to evaluate the contact Neo-dymium : yttrium aluminum garnet(Nd:YAG) laser system for vascular anastomosis of small caliber blood vessels(diameter 0.5-1.2 mm) in the animal model. In this study 40 femoral arteries and 40 femoral veins of Sprague-Dawley rats were anastomosed by contact laser assisted microvascular anastomosis(LAMA) utilizing 3 stay sutures which were placed 120 degrees apart and the intervals welded with contact Nd:YAG laser unit, conventionally sutured anastomosis(CSA) served as controls. The time needed for vascular anastomosis, patency rate(immediate postoperative, postoperative 2nd day, postoperative 1 week, postoperative 4 weeks), gross and microscopic evaluations were compared to conventional microsurgical suture technique. The results are as follows: 1. Postoperative patency rate was 82.5% for femoral artery and 75% for femoral vein by contact LAMA technique compared to 90% and 75% by CSA technique at postoperative 4 weeks. 2. Less time-consumed for arterial anastomosis by 6 minutes 23 seconds and venous anastomosis by 8 minutes 55 seconds with contact LAMA technique compared to CSA technique. 3. Grossly almost complete healing had taken place by postoperative 1 week by contact LAMA technique. 4. Aneurysm formation was 5% for femoral artery and 15% for femoral vein by contact LAMA technique compared to 5% and 10% respectively by CSA technique. 5. Microscopically, re-endothelization was complete by postoperative 7th day by contact LAMA technique. There was less medial hypertrophy and hyperplasia and also less inflammatory response compared to CSA.

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Maximum Shear Reinforcement of RC Beams using High Strength Concrete (고강도 콘크리트를 사용한 RC보의 최대철근비)

  • Lee, Jung-Yoon;Hwang, Hyun-Bok
    • Proceedings of the Korea Concrete Institute Conference
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    • 2008.11a
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    • pp.839-842
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    • 2008
  • The ACI 318-05 code requires the maximum amount of shear reinforcement in reinforced concrete (RC) beams to prevent possible sudden shear failure due to over reinforcement. The design equations of the maximum amount of shear reinforcement provided by the current four design codes, ACI 318-05, CSA-04, EC2-02, and JCI-99, differ substantially from one another. The ACI 318-05, CSA-04, and EC2-02 codes provide an expression for the maximum amount of shear reinforcement ratio as a function of the concrete compressive strength, but Japanese code does not take into account the influence of the concrete compressive strength. For high strength concrete, the maximum amount of shear reinforcement calculated by the EC2-02 and CSA-04 is much greater than that calculated by the ACI 318-05. This paper presents the effects of shear reinforcement ratio and compressive strength of concrete on the maximum shear reinforcement in reinforced concrete beams. Ten RC beams having various shear reinforcement ratio were tested. Although the test beams were designed to have much more amount of shear reinforcement than that required in the ACI 318-05 code, all beams failed due to web concrete crushing after the stirrups reached the yield strain.

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New Approach to Chuncheon Dakgalbi Processing by Various Chicken Materials, Seasoning and Cooking Methods

  • Muhlisin, Muhlisin;Kang, Sun Moon;Choi, Won Hee;Kim, Cheon-Jei;An, Byoung Ki;Kang, Chang Won;Lee, Sung Ki
    • Food Science of Animal Resources
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    • v.32 no.6
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    • pp.740-748
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    • 2012
  • This research was conducted to develop a new approach to Chuncheon Dakgalbi processing by various chicken materials, seasoning (conventional sauce/CS and new approach of seasoning by adding the curing mixture/CSA), and cooking methods. Three chicken breeds (broiler, old broiler and spent laying hen) were divided into five experimental groups: broiler-CS, old broiler-CS, old broiler-CSA, spent laying hen-CS, and spent laying hen-CSA. All samples were stored at $5^{\circ}C$ for 12 d. For sensory evaluation, all samples were cooked with conventional cooking (pan grilling) or high temperature and pressure cooking (at $121^{\circ}C$ with pressure 1.5 $Kg_f/cm^2$ for 30 min). The chicken material analysis showed that the moisture and crude protein content, cooking loss and shear-force of the old broiler and spent laying hen were higher (p<0.05) than those of the current broiler, but the crude ash, crude lipid and WHC were lower (p<0.05). The addition of CSA increased the pH value and reduced the lipid oxidation at the end of storage regardless of chicken breeds (p<0.05). The high temperature and pressure cooking method seemed to increase the taste, smell and overall-acceptability scores of the old broiler and spent laying hen Chuncheon Dakgalbi regardless of the implementation of new approach of seasoning (CSA). In conclusion, an old broiler and spent laying hen can be used as material of Chuncheon Dakgalbi by the application of a new approach of seasoning and cooking method.

Comparison and Evaluation of Current Strut-and-Tie Design Provisions for Reinforced Concrete Deep Beams (철근콘크리트 깊은 보의 현행 스트럿-타이 설계기준에 대한 비교 및 평가)

  • Kim, Jin Woo;Hong, Sung-Gul;Lee, Young Hak;Kim, Heecheul;Kim, Dae-Jin
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.27 no.4
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    • pp.305-312
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    • 2014
  • The current American Concrete Institute(ACI), Canadian Standard Associate(CSA) and CEB-FIP Model Code 2010 provisions on the shear strength of a simply supported deep beam suggest that deep beams should be designed using the strut-and-tie model. Although this is a useful methodology to design members in disturbed regions, the quality of the design is highly dependent on the truss model that designers create. However, Hong et al. derived the shear strength equations of reinforced concrete deep beams. This thesis investigates the validity of the current ACI, CSA and CEB-FIP code provisions on the shear strength of simply supported reinforced concrete deep beams by comparing them with the shear strength equations proposed by Hong et al. The comparison shows that all of these code provisions provide reasonable estimates on the shear strength of concrete deep beam members and the selection of an internal truss model plays an important role on the estimation of shear strength.

Performance of cement-stabilized sand subjected to freeze-thaw cycles

  • Jumassultan, Assel;Sagidullina, Nazerke;Kim, Jong;Ku, Taeseo;Moon, Sung-Woo
    • Geomechanics and Engineering
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    • v.25 no.1
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    • pp.41-48
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    • 2021
  • In cold regions, the integrity of the infrastructures built on weak soils can be extensively damaged by weathering actions due to the cyclic freezing and thawing. This damage can be mitigated by exploiting soil stabilization techniques. Generally, ordinary Portland cement (OPC) is the most commonly used binding material for investigating the chemo-hydromechanical behavior. However, due to the environmental issue of OPC producing a significant amount of carbon dioxide emission, calcium sulfoaluminate (CSA) cement can be used as one of the eco-sustainable alternatives. Although recently several studies have examined the strength development of CSA treated sand, no research has been concerned about CSA cement-stabilized sand affected by cyclic freeze and thaw. This study aims to conduct a comprehensive laboratory work to assess the effect of the cyclic freeze-thaw action on strength and durability of CSA cement-treated sand. For this purpose, unconfined compressive strength (UCS) and ultrasonic pulse velocity (UPV) tests were performed on the stabilized soil specimens cured for 7 and 14 days which are subjected to 0, 1, 3, 5, and 7 freeze-thaw cycles. The test results show that the strength and durability index of the samples decrease with the increase of the freeze-thaw cycles. The loss of the strength and durability considerably decreases for all soil samples subjected to the freeze-thaw cycles. Overall, the use of CSA as a stabilizer for sandy soils would be an eco-friendly option to achieve sufficient strength and durability against the freeze-thaw action in cold regions.