• Advances in concrete construction
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• v.5 no.2
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• pp.87-99
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• 2017

After passing through a magnetic field, the physical quality of water improves, and magnetic water (MW) is produced. There are many investigations on the effects of magnetic field on water that shows MW properties like saturation and memory effect. This study investigates the fresh and hardened properties of concrete mixed with MW, which contains silica fume (SF) and superplasticizer (SP). The test variables included the magnetic field intensity for producing MW (three kinds of water), SF content replaced cement (0 and 10 percent), water-to-cementitious materials ratio (W/CM=0.25, 0.35 and 0.45) and curing time (7, 28 and 90 days). The results of this study show that MW had a positive impact on the workability and compressive strength of concrete. By rising the intensity of the magnetic field which was used for producing MW, its positive influence on both workability and compressive strength improved. MW had greater positive impacts on samples containing SP that did not have SF. Moreover, the best compressive strength improvements of concrete achieved as W/CM ratio decreased.

• Advances in concrete construction
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• v.8 no.1
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• pp.1-7
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• 2019

The possibility of using recycled coarse glass aggregates as a substitute for natural crushed stone are relatively limited. In order to promote it for engineering application, this paper reports the effect of coarse glass aggregate on mechanical behavior of concrete. The coarse aggregates are substituted for coarse glass aggregate (CGA) as 0%,20%,40%,60%,80% and 100%.The results show that increasing the coarse glass aggregate content cause decrease in compressive strength, the elastic modulus, the splitting tensile strength, the flexural strength. An equation is presented to generate the relationship between cube compressive strength and prism compressive strength, the relationship between cube compressive strength and elastic modulus, the relationship between cube compressive strength and splitting tensile strength, the relationship between cube compressive strength and flexural strength of coarse glass concrete.

• Advances in concrete construction
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• v.12 no.6
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• pp.461-467
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• 2021

Polyethylene-terephthalate (PET) from bottle waste and linear low-density polyethylene (LLDPE) from barrels and tanks waste are widely available and need to be recycled. Recycling them in concrete and mortar is an alternative solution for their disposal. In this study various quantities of sand (5%, 10%, 15% and 20%) were substituted by powder from LLDPE waste. In addition, PET waste fibers (corrugated, straight) were added to the mortar with different percentages (0.5%, 1%, 1.5% and 2%) of cement mass. This paper evaluate the mechanical and physical properties of the composites in fresh (workability, air content and density) and hardened state (compressive and flexural strength, water absorption and total shrinkage). From the experimental results, it can be concluded that the strengthening in tensile of the mortar with plastic waste corrugated fibers is improved. Other important results are that the water absorption and the density rate are less than that of the ordinary mortar.

• Korean journal of food and cookery science
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• v.23 no.3 s.99
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• pp.409-412
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• 2007

The aim of this study was to examine the content of bioactive component, ${\gamma}$-aminobutyric acid (GABA) in 7 commercial green teas. The teas were grown in different regions in Sourhtern Korea, and were picked during the middle of the season. The green tea extracts were each derivatized with 6-aminoquinolyl-N-hydroxy-succinimidyl carbamate(AccQ${\cdot}$Fluor), and GABA was detected by a fluorescence detector at arf excitation of 250 nm and emission of 395 nm. The GABA contents varied depending on the regions where the green tea samples were produced. There was no significant difference in GABA contents between samples A and C, where it ranged from from 45.21${\pm}$0.99 (nmol/g) to 63.83${\pm}$0.61 (nmol/g): however, a significantly different amount of GABA was found in the green tea produced in B. The highest GABA content was 210.67${\pm}$0.85 (nmol/g), whereas the lowest content was 3.88${\pm}$0.71 (nmol/g). This variation in GABA contents was probably due to the regional differences, even within the same location, as well as the processing technology, which may retain or develop more GABA components in the final green tea.

• Advances in concrete construction
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• v.8 no.1
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• pp.65-76
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• 2019

This paper investigates the effect of recycled glass powder (RGP) on flowing properties of self-compacting mortars (SCMs) containing different ratios of fillers and superplasticizer dosages. Fly ash (FA), nano-silica (NS), micro-silica (MS), metakaolin (MK) and rice husk ash (RHA) are used as fillers and their synergistic effect with RFP is studied. The effects of fillers and high-range water reducer (HRWR) on flowing ability of mortars are primarily determined by slump flow and V-funnel flow time tests. The results showed that for composites with a higher RGP content, the mortar flowing ability increased but tended to decrease when the composites containing 10% MK or 5% RHA. However, the flowing ability of samples incorporating 5% RGP and 10% SF or 25% FA showed an opposite result that their slump flow spread decreased and then increased with increasing RGP content. For specimens with 3% NS, the influence of RGP content on flowing properties was not significant. Except RHA and MS, the fillers studied in this paper could reduce the dosage of HRWR required for achieving the same followability. Also, the mixture parameters were determined and indicated that the flowability of mixtures was also affected by the content of sand and specific surface area of cement materials. It is believed that excess fine particles provided ball-bearing effect, which could facilitate the movement of coarse particles and alleviate the interlocking action among particles. Also, it can be concluded that using fillers in conjunction with RGP as cementitious materials can reduce the material costs of SCM significantly.

• Advances in concrete construction
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• v.15 no.3
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• pp.161-170
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• 2023

Ultra-high-performance concrete (UHPC) is produced using high amount of cementitious materials, very low water/cementitious materials ratio, fine-sized fillers, and steel fibers. Due to the dense microstructure of UHPC, it possesses very high strength, elasticity, and durability. Besides that, the UHPC exhibits high ductility and fracture toughness due to presence of fibers in its matrix. While the high ductility of UHPC allows it to undergo high strain/deflection before failure, the high fracture toughness of UHPC greatly enhances its capacity to absorb impact energy without allowing the formation of severe cracking or penetration by the impactor. These advantages with UHPC make it a suitable material for construction of the structural members subjected to special loading conditions. In this research work, the UHPC mixtures having three different dosages of steel fibers (2%, 4% and 6% by weight corresponding to 0.67%, 1.33% and 2% by volume) were characterized in terms of their mechanical properties including facture toughness, before using these concrete mixtures for casting the slab specimens, which were tested under high-energy impact loading with the help of a drop-weight impact test setup. The effect of fiber content on the impact energy absorption capacity and central deflection of the slab specimens were investigated and the equations correlating fiber content with the energy absorption capacity and central deflection were obtained with high degrees of fit. Finite element modeling (FEM) was performed to simulate the behavior of the slabs under impact loading. The FEM results were found to be in good agreement with their corresponding experimentally generated results.

• Korean Journal of Medicinal Crop Science
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• v.28 no.6
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• pp.395-411
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• 2020

Background: This study investigated the anti-obesity effect of the flavonoid rich fraction (FRF) and its constituent, rutin obtained from the leaf of Morus alba L., on the lipid accumulation mechanism in 3T3-L1 adipocyte and C57BL/6 mouse models. Methods and Results: In Oil Red O staining, FRF (1,000 ㎍/㎖) treatments showed inhibition rate of 35.39% in lipid accumulation compared to that in the control. AdipoRedTM assay indicated that the triglyceride content in 3T3-L1 adipocytes treated with FRF (1,000 ㎍/㎖) was reduced to 23.22%, and free glycerol content was increased to 106.04% that of the control. FRF and its major constituent, rutin affected mRNA gene expression. Rutin contributed to the inhibition of Sterol regulatory element binding protein-1c (SREBP-1c) gene expression, and inhibited the transcription factors SREBP-1c, peroxisome proliferator-activated receptor gamma (PPAR-γ), CCAAT/enhancer binding protein α (C/EBPα), fatty acid synthase (FAS) and acetyl-CoA carboxylase (ACC). In addition, the effect of FRF administration on obesity development in C57BL/6 mice fed high-fat diet (HFD) was investigated. FRF suppressed weight gain, and reduced liver triglyceride and leptin secretion. FRF exerted potential anti-inflammatory effects by improving insulin resistance and adiponectin levels, and could thus be used to help counteract obesity. The mRNA expressions of PPAR-γ, FAS, ACC, and CPT-1 were determined in liver tissue. Quantitative real-time PCR analysis was also performed to evaluate the expression of IL-1β, IL-6, and TNF-α in epididymal adipose tissue. Compared to the control group, mice fed the HFD showed the up-regulation in PPAR-γ, FAS, IL-6, and TNF-α genes, and down-regulation in CPT1 gene expression. FRF treatement markedly reduced the expression of PPAR-γ, FAS, IL-6, and TNF-α compared to those in HFD control, whereas increased the expression level of CPT1. Conclusions: These results suggest that the FRF and its major active constituent, rutin, can be used as effective anti-obesity agents.

• Asian-Australasian Journal of Animal Sciences
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• v.10 no.2
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• pp.185-191
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• 1997

This experiment was conducted to determine the effects of a low-protein diet supplemented with DL-methionine plus L-cystine (Met + Cys) on the growth performance and fat accumulation of female broiler chicks during the growing period (3-6 wks old). A low-protein diet (17% CP; 3,200 ME kcal/kg) was supplemented with Met + Cys (1.1 : 1.0) at levels 0.75, 0.94, 1.25, 1.31 or 1.50% of diet, respectively. Another diet with 21% CP and 3,200 ME kcal/kg served as the control group. All essential amino acids were adjusted to meet the National Research Council (1984) requirement for chicks. Feed and water were given ad libitum. Body weight of the chicks fed the low-CP diets supplemented with Met + Cys were heavier than those of the control birds. Feed conversion ratio and feed intakes were not significantly different between and among the treatment groups. Similary, abdominal fat content was not significantly different among the various treatments except that of the chicks fed the low CP diet with 1.25% Met + Cys which was higher than that of the control group. Fatty acid synthetase (FAS), acetyl-CoA carboxylase (ACC) activities and carcass protein content were not influenced by dietary treatments. Carcass fat content was lowest in chicks fed low CP diet with 0.75% Met + Cys and highest in the group that received 1.50% Met + Cys supplementation. Liver triglyceride increased as Met + Cys supplementation level increased. Various lipid fraction concentrations (cholesterol ester, free cholesterol, and phospholipid) in the serum went up as Met + Cys increased up to 1.25% after which it levelled off. Results of this experiment suggest that it is possible to reduce dietary protein level from 21% to 17% for growing broiler chicks by the supplementation of Met + Cys when other EAA were sufficient.

• Advances in concrete construction
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• v.10 no.1
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• pp.81-92
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• 2020

Flexural and splitting strength behavior of conventional concrete can significantly be improved by incorporating the fibers in it. A significant number of research studies have been conducted on various types of fibers and their influence on the tensile capacity of concrete. However, as an important property, tensile capacity of fiber reinforced concrete (FRC) is not modelled properly. Therefore, this paper intends to formulate a model based on experiments that show the relationship between the fiber properties such as the aspect ratio (length/diameter), fiber content, compressive strength, flexural strength and splitting strength of FRC. For the purpose of modeling, various FRC mixes only with steel fiber are adopted from the existing research papers. Automated neural network search (ANS) is then developed and used to investigate the effect of input parameters such as fiber content, aspect ratio and compressive strength to the output parameters of flexural and splitting strength of FRC. It is found that the ANS model can be used to predict the flexural and splitting strength of FRC in a sensible precision.

• Advances in concrete construction
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• v.9 no.5
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• pp.449-457
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• 2020

The influence of subsequent curing on the performance of fly ash contained mortar under steam curing was studied. Mortar samples incorporated with different content (0%, 20%, 50% and 70%) of Class F fly ash under five typical subsequent curing conditions, including standard curing (ZS), water curing(ZW) under 25℃, oven-dry curing (ZD) under 60℃, frozen curing (ZF) under -10℃, and nature curing (ZN) exposed to outdoor environment were implemented. The unsteady chloride diffusion coefficient was measured by rapid chloride migration test (RCM) to analyze the influence of subsequent curing condition on the resistance to chloride penetration of fly ash contained mortar under steam curing. The compressive strength was measured to analyze the mechanical properties. Furthermore, the open porosity, mercury intrusion porosimetry (MIP), x-ray diffraction (XRD) and thermogravimetric analysis (TGA) were examined to investigate the pore characteristics and phase composition of mortar. The results indicate that the resistance to chloride ingress and compressive strength of steam-cured mortar decline with the increase of fly ash incorporated, regardless of the subsequent curing condition. Compared to ZS, ZD and ZF lead to poor resistance to chloride penetration, while ZW and ZN show better performance. Interestingly, under different fly ash contents, the declining order of compressive strength remains ZS>ZW>ZN>ZD>ZF. When the fly ash content is blow 50%, the open porosity grows with increase of fly ash, regardless of the curing conditions are diverse. However, if the replacement amount of fly ash exceeds a certain high proportion (70%), the value of open porosity tends to decrease. Moreover, the main phase composition of the mortar hydration products is similar under different curing conditions, but the declining order of the C-S-H gels and ettringite content is ZS>ZD>ZF. The addition of fly ash could increase the amount of harmless pores at early age.