• Title/Summary/Keyword: AAB

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Laboratory investigations on the effects of acid attack on concrete containing portland cement partially replaced with ambient-cured alkali-activated binders

  • Ramagiri, Kruthi K.;Patil, Swaraj;Mundra, Harsh;Kar, Arkamitra
    • Advances in concrete construction
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    • v.10 no.3
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    • pp.221-236
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    • 2020
  • To reduce the CO2 emissions associated with the manufacture of portland cement (PC), an efficient alternative like an alkali-activated binder (AAB) is the requirement of the industry. To promote the use of AAB in construction activities, a practically implementable mix proportion is required. Owing to the several raw ingredients of AAB concrete and their associated uncertainties, partial replacement of PC by AAB may be adopted instead of complete replacement as per industrial requirements. Hence, the present study aims to determine an optimal proportion for partial replacement of PC with AAB and recommend a technique for it based on site conditions. Three modes of partial replacement are followed: combining all the dry ingredients for AAB and PC followed by the addition of the requisite liquids (PAM); combining the PC and the AAB concrete in two horizontal layers (PAH); and two vertical layers (PAV). 28-day old specimens are exposed to 10% v/v solutions of HCl, H2SO4, and HNO3 to evaluate changes in mechanical, physical, and microstructural characteristics through compressive strength, corrosion depth, and microscopy. Based on deterioration in strength and integrity, PAH or PAV can be adopted in absence of acid attack, whereas PAM is recommended in presence of acid attack.

Molecular Identification and Technological Properties of Acetic Acid Bacteria Isolated from Malatya Apricot and Home-Made Fruit Vinegars

  • Buyukduman, Eda;Kirtil, Hatice Ebrar;Metin, Banu
    • Microbiology and Biotechnology Letters
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    • v.50 no.1
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    • pp.81-88
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    • 2022
  • Acetic acid bacteria (AAB) are versatile organisms involved in the production of variety of fermented foods, such as vinegar and kombucha, and products of biotechnological relevance, such as bacterial cellulose. In the present study, Malatya apricot, a variety with protected designation of origin (PDO), and vinegar samples produced using various fruits were used to isolate AAB. The 19 AAB isolates obtained were typed using (GTG)5 fingerprinting, and the ones selected were identified by sequencing either 16S rDNA alone or in combination with 16S-23S rRNA internal transcribed spacer region or ligA gene. While all apricot isolates (n = 10) were Gluconobacter cerinus, vinegar isolates (n = 9) were composed of Komagataeibacter saccharivorans, Acetobacter syzygii, and possible two new species of AAB, Komagataeibacter sp., and Gluconobacter sp. (GTG)5 fingerprinting showed the presence of several genotypes of G. cerinus in the apricot samples. Screening for some technologically relevant properties, including thermotolerance, ethanol tolerance, and cellulose production capability, showed that all Komagataeibacter and some Gluconobacter isolates could tolerate the temperature of 35℃, and that vinegar isolates could tolerate up to 8% ethanol. One isolate, Komagataeibacter sp. GUS3 produced bacterial cellulose (1 g/l) and has the potential to be used for cellulose production.

Prediction models for compressive strength of concrete with Alkali-activated binders

  • Kar, Arkamitra;Ray, Indrajit;Unnikrishnan, Avinash;Halabe, Udaya B.
    • Computers and Concrete
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    • v.17 no.4
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    • pp.523-539
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    • 2016
  • Alkali-activated binder (AAB) is increasingly being considered as an eco-friendly and sustainable alternative to portland cement (PC). The present study evaluates 30 different AAB mixtures containing fly ash and/or slag activated by sodium hydroxide and sodium silicate by correlating their properties from micro to specimen level using regression. A model is developed to predict compressive strength of AAB as a function of volume fractions of microstructural phases (physicochemical properties) and ultrasonic pulse velocity (elastic properties and density). The predicted models are ranked and then compared with the experimental data. The correlations were found to be quite reasonable (R2 = 0.89) for all the mixtures tested and can be used to estimate the compressive strengths for similar AAB mixtures.

Development of Polyclonal Antibodies to Abdominal and Subcutaneous Adipocyte for Reducing Body Fat of Rat (흰쥐 체지방 감소를 위한 지방부위별 특이 다클론 항체 개발 연구)

  • Choi, Chang-Weon;Park, Dong-Woo;Jo, Ik-Hwan;Oh, Young-Kyoon;Chang, Sun-Sik;Choi, Nag-Jin;Kam, Dong-Keun;Baek, Kyoung-Hoon
    • Journal of agriculture & life science
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    • v.46 no.5
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    • pp.47-55
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    • 2012
  • Polyclonal antisera against regional (abdominal and subcutaneous) fats were developed to reduce body fat in rats. Isolation and culture of abdominal and subcutaneous adipocytes of rats were performed for analyzing lactate dehydrogenase (LDH) concentration. At the level of 1:1,000 dilution, little antibody reactivity appeared in non-immunized serum whereas both of antisera against abdominal (AAb) and subcutaneous adipocyte plasma membrane proteins (SAb) had relatively strong reactivity till the level of 1:128,000 dilutions. Compared with regional fats, extremely low reactivities of AAb and SAb were detected with PMP of the organs (p<0.001). Both AAb and SAb were most strongly reacted with each adipocyte plasma memebrane proteins and showed statistically (p<0.01) higher cross-reactivities compared with non-immunized serum based on LDH analysis. In conclusion, these results may indicate that the present polyclonal antibodies against regional inedible adipocyte plasma membrane proteins are well developed and have safety in cross-reactivities with body organs.

The Study on the Landscape Preference and Characteristics of the Agricultural Aqueduct Bridges (수로교 경관선호도 및 이미지 특성 분석)

  • Joo, Shin-Ha
    • Journal of Korean Society of Rural Planning
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    • v.18 no.3
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    • pp.67-76
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    • 2012
  • The purpose of this study is to analyze the landscape preference and landscape images of the Agricultural Aqueduct Bridges(AAB) by several different criteria. Semantic Differential Scale(SD scale) with landscape adjectives and landscape preference are used to estimate the alternatives of the AAB. The statistic methods such as descriptive analysis, t-test, factor analysis and regression, cluster analysis, are operated. The landscape preference of the alternatives is generally positive, 3.977 out of 7.000. The gate type is the most preferred, but the road-along type is the worst, by the location types. The simple repair type is the worst preferred, but total remodeling is the most, by the repair types. The characteristics of the AAB are analyzed and 4 factors of visual landscape are contracted; interest, orderliness, naturality and spatiality. Cumulative factor loading of these factors is about 65%, which is quite high. The higher and bigger AAB's are preferred, and the advanced finishing materials are also preferred, such as aluminum or wood panels. The long span is also preferred and the high repair cost would be preferred. But in this study, the cost-benefit analysis is not included, so it is recommended to research further, considering the cost variable with the visual factors.

Electroluminescent Properties of White Light-Emitting Device Using Photoconductive Polymer and Anthracene Derivatives (광전도성 고분자와 안트라센 유도체를 이용한 백색 전계발광소자의 발광 특성)

  • Lee Jeong-Hwan;Choi Hee-Lack;Lee Bong
    • Korean Journal of Materials Research
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    • v.15 no.8
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    • pp.543-547
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    • 2005
  • Organic electroluminescence devices were made from 1,4-bis-(9-anthrylvinyl)benzene (AVB) and 1,4-bis-(9-aminoanthryl)benzene (AAB) anthracene derivatives. Device structure was ITO/AVB/PANI(EB)/Al (multi-layer device) and ITO/AAB:DCM/Al(single-layer device). In these devices, AVB, polyaniline(emeraldine base) (PANI(EB)) and AAB were used as the emitting material. 4-(dicyanomethylene)-2-methyl-6-p-(dimethylamino)styryl-4H -pyran(DCM) was used as red fluorescent dopant. We studied change of fluorescence wavelength with concentration of DCM doped in AAB. The ionization potential (IP) and optical band gap (Eg) were measured by cyclic voltammetry and UV-visible spectrum. We compared with difference of emitting wavelength between photoluminescence and electroluminescence spectrum. In case of the multi-layer device, PANI and AVB EL spectra have similar wave pattern to each PL spectrum and when PAM and AVB were used at the same time, and multi-layer device showed that a balanced recombination and radiation kom PANI and AVB. In case of the single-layer device, with the increase of DCM concentration, the blue emission decreases and red emission increases. This indicates that DCM was excited by the energy transfer from AAB to DCM or the direct recombination at the dopant sites due to carrier trapping, or both. The device with $1.0wt\%$ DCM concentration gave white light.

Bone Healing Properties of Autoclaved Autogenous Bone Grafts Incorporating Recombinant Human Bone Morphogenetic Protein-2 and Comparison of Two Delivery Systems in a Segmental Rabbit Radius Defect

  • Choi, Eun Joo;Kang, Sang-Hoon;Kwon, Hyun-Jin;Cho, Sung-Won;Kim, Hyung Jun
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.36 no.3
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    • pp.94-102
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    • 2014
  • Purpose: This study aims to validate the effect of autoclaved autogenous bone (AAB), incorporating Escherichia coli-derived recombinant human bone morphogenetic protein-2 (ErhBMP-2), on critical-sized, segmental radius defects in rabbits. Delivery systems using absorbable collagen sponge (ACS) and fibrin glue (FG) were also evaluated. Methods: Radius defects were made in 12 New Zealand white rabbits. After autoclaving, the resected bone was reinserted and fixed. The animals were classified into three groups: only AAB reinserted (group 1, control), and AAB and ErhBMP-2 inserted using an ACS (group 2) or FG (group 3) as a carrier. Animals were sacrificed six or 12 weeks after surgery. Specimens were evaluated using radiology and histology. Results: Micro-computed tomography images showed the best bony union in group 2 at six and 12 weeks after operation. Quantitative analysis showed all indices except trabecular thickness were the highest in group 2 and the lowest in group 1 at twelve weeks. Histologic results showed the greatest bony union between AAB and radial bone at twelve weeks, indicating the highest degree of engraftment. Conclusion: ErhBMP-2 increases bony healing when applied on AAB graft sites. In addition, the ACS was reconfirmed as a useful delivery system for ErhBMP-2.

Report of eight unrecorded Acetobacter species in Korea, discovered during the survey in 2018-2019

  • Heo, Jun;Won, Miyoung;Lee, Daseul;Han, Byeong-Hak;Hong, Seung-Beom;Kwon, Soon-Wo
    • Journal of Species Research
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    • v.11 no.3
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    • pp.155-161
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    • 2022
  • Acetic acid bacteria (AAB) convert ethanol to acetic acid through oxidation, and the fermentation pathway of AAB is important in the vinegar industry. The genus Acetobacter is the representative one of AAB, and several Korean traditional vinegars are produced using Acetobacter strains. Until now, four species in the genus Acetobacter were reported as native species in Korea. During the past two years, we isolated several AAB strains from fruits, flowers and fermented foods, and several AAB species unrecorded in Korea were found on the basis of 16S rRNA gene sequence analyses. In this study, we report eight Acetobacter species as native ones which are A. fabarum C10-3 (=KACC 21483) isolated from plumcot fruit (Naju-si), A. lovaniensis KDG-EC1 (=KACC 22697) isolated from diced radish kimchi (Naju-si), A. okinawensis GAM12-M2 (=KACC 22696) isolated from persimmon fruit (Sangju-si), A. orientalis FR32C4 (=KACC 22370) isolated from fruit of Cudrania tricuspidata (Jeonju-si), A. papaya FR35B3 (=KACC 22046) isolated from grape fruit (Yeongdong-gun), A. suratthaniensis GAM15-R2 (=KACC 22694) isolated from persimmon fruit(Gimje-si), A. syzygii C25-1 (=KACC 22048) isolated from peach fruit (Namwon-si) and A. thailandicus JDF1-M1 (=KACC 22693) isolated from plum fruit(Seoul).

Effects of Polyclonal Antibody Candidate to Adipocytes for Reducing Body Fat on Body Weight, Fecal Digestibility and Blood Metabolites in Pigs (체지방 감소 다클론 후보 항체가 비거세돈의 체중, 분 소화율 및 혈액 대사물질에 미치는 영향)

  • Choi, Chang-Weon;Baek, Kyung-Hoon;Cho, Sung-Back;Oh, Young-Kyoon;Hong, Seong-Koo;Choi, Chang-Bon
    • Journal of Animal Science and Technology
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    • v.52 no.5
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    • pp.375-382
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    • 2010
  • Twelve pigs were used to investigate the effects of polyclonal antibody candidate against abdominal (AAb) and subcutaneous adipocyte membrane proteins (SAb) on body weight, fecaldigestibility and blood metabolites. When AAb and SAb developed by Choi et al. (2010) were injected to pigs, the numerical increase in BW (body weight) occurred at 4 weeks post-treatment, but BW for an entire period was also increased, indicating that the BW increase may not be affected by the antibodies injection. Antibodies treatment did not affect (P>0.05) fecal digestibility of dry matter, crude protein, crude fat and crude fiber. Fecal digestibility of crude ash for control (no treatment) at 2 weeks decreased, and that for non-immunized serum treatmentgroup at 4 weeks post-treatment increased, respectively (P<0.05). However, fecal digestibility of crude ash for AAb and SAb groups did not significantly change. At 4 weeks after the antibodies treatment, blood urea N concentration for AAb and SAb groups was significantly increased (P<0.05). However, these increases may not be caused by the antibodies treatment because similar pattern in blood urea N concentration occurred before the antibodies treatment. Antibodies treatment did not affect concentration of plasma glucose and triglycerides (P<0.05). Compared with control, concentration of plasma total cholesterol for AAb and SAb groups at 4 weeks post-treatment was significantly (P<0.05) decreased. This may suggest that body fat reduction possibly occurs. In conclusion, the AAb and the SAb developed by Choi et al. (2010) may have safety in nutritional physiological metabolism in pigs. Further study on in vivo fat reduction of the antibodies against abdominal and subcutaneous adipocytes of pigs should be required for fat-reduced pork production.