• Journal of Microbiology and Biotechnology
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• v.30 no.1
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• pp.21-30
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• 2020

Natural products are widely used due to their various biological activities which include anti-inflammatory, antioxidant, and anti-obesity effects. In this study, we determined the antioxidative and anti-obesity effects of Polygonum cuspidatum 50% ethanol extract (PEE). The antioxidative effect of PEE was evaluated using its radical scavenging activity, total phenolic content, and reducing power. The anti-obesity effect of PEE was investigated using 3T3-L1 adipocytes. The antioxidative activity of PEE was progressively increased in various concentrations, mainly due to the presence of phenolic compounds. PEE also alleviated lipid accumulation on 3T3-L1 adipocytes and downregulated the mRNA and protein production of adipogenesis-related (SREBP-1c, PPARγ, C/EBPα) and lipogenesis-related (aP2, FAS, ACC) markers. Furthermore, we found that the inhibitory effect on lipid accumulation via PEE was caused by the alleviation of NF-κB, p38 MAPK, ERK1/2, and JNK at the protein level. Taken together, our results imply that PEE is a potential antioxidant that can prevent obesity-associated disorders.

• Advances in concrete construction
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• v.9 no.2
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• pp.217-225
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• 2020

The recovery of waste proves a solution with two impacts: the environmental impact by the reduction of pollution and the gain of the occupied space by this waste, and the economic impact by the use of these lasts in the building and in the area of public works. The present research consists in recovering a waste marble (thrown powder exposed to the different meteorological phenomena) generated by the quarry marble of Fil-fila, located at the east side of Skikda in the north-east of Algeria, and add it, as sand in the composition of sand concrete. To carry out this research, we analyzed the evolution brought by the substitution of ordinary sand by marble waste sand, with 25%, 50%, 75% and 100% on the properties in the fresh state (density, workability and air content) and in the cured state (compressive strength, tensile strength, surface hardness and sound velocity). For durability we tested water absorption by immersion and chloride penetration. The results obtained are compared with control samples of 0% of substitution rate. In order to have a good filling of the voids in the granular skeleton; we added a quantity of limestone recycled fines from the quarries and for a good workability a super-plasticizing additive. The results showed that the partial substitution modified both the fresh and the hardened characteristics of the tested concretes, the durability parameters also improved.

• Advances in concrete construction
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• v.10 no.5
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• pp.455-462
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• 2020

This study investigated the effect of horizontal casting joints on the mechanical properties and structural behavior of sustainable self-compacting reinforced concrete beams (SCRCB). The experimental research consisted of two stages. The first stage used four types of concrete mixtures which were produced to indicate the effects of cement replaced with cement waste at 0%, 5%, 10%, and 15% by weight of cement content on fresh concrete properties of self-compacting concrete (SCC) such as, passing ability, filling ability, and segregation resistance. In addition, mechanical properties such as compressive, tensile, and flexural strength were also studied. The second stage selected the best mixture from the first stage and studied the effect of horizontal casting joints on the structural behavior of sustainable SCRCBs. The effect of horizontal casting joints on the mechanical properties and structural behavior were at the 25%, 50%, 75%, and 100% of sample height. Load deflection, failure mode, and theoretical analysis were studied. Results indicated that the incorporation of replacement with cement waste by 5% to 10% led to economic and environmental advantages, and the results were acceptable for fresh and mechanical properties. The results indicated that delaying the time for casting the second layer and increasing the cement waste in concrete mixtures had a great effect on the mechanical properties of SCC. The ultimate load capacity of horizontal casting joints reinforced concrete beams slightly decreased compared with the control beam. The maximum deflection of casting joint beams with 75% of samples height is similar with the control beam. The experimental results of reinforced concrete beams were substantially acceptable with the theoretical results. The failure modes obtained the best forced casting joint on the structural behavior at 50% height of casting in the beam.

• Advances in concrete construction
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• v.9 no.6
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• pp.537-545
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• 2020

In order to reduce the usage of cement slurry in grouting engineering and consume the tunnel excavation waste soil, a new geopolymeric grouting material (GGM) was prepared by combine completely weathered granite (CWG) and blast-furnace slag (BFS), which can be applied to in-situ grouting treatment of completely weathered granite strata. The results showed CWG could participate in the geopolymerization process, and GGM slurry has the characteristics of short setting time, high flowability, low viscosity, high stone rate and high mechanical strength, and a design method of grouting pressure based on viscosity evolution was proposed. By adjusted the content of completely weathered granite and alkali activator concentration, the setting time of GGM were ranged from 5 to 30 minutes, the flowability was more than 23.5 cm, the stone rate was higher than 90%, the compressive strength of 28 days were 7.8-16.9 MPa, the porosity were below 30%. This provides a novel grouting treatment and utilizing excavated soil of tunnels in the similar strata.

• Advances in concrete construction
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• v.4 no.2
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• pp.71-88
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• 2016

Metakaolin, a dehydroxylated product of the mineral kaolinite, is one of the most valuable admixtures for high-performance concrete applications, including constructing reinforced concrete bridges and impact- and fire-resistant structures. Concretes produced using metakaolin become more homogeneous and denser compared to normal-strength concrete. Yet, these changes cause a change of volume throughout hardening, and increase the brittleness of hardened concrete significantly. In order to examine how the use of metakaolin affects the fracture and mechanical behavior of high-performance concrete we produced concretes using a range of water to binder ratio (0.42, 0.35 and 0.28) at three different weight fractions of metakaolin replacement (8%, 16% and 24%). The results showed that the rigidity of concretes increased with using 8% and 16% metakaolin, while it decreased in all series with 24% of metakaolin replacement. Similar effect has also been observed for other mechanical properties. While the peak loads in load-displacement curves of concretes decreased significantly with increasing water to binder ratio, this effect have been found to be diminished by using metakaolin. Pore structure analysis through mercury intrusion porosimetry test showed that the addition of metakaolin decreased the critical pore size of paste phases of concrete, and increasing the amount of metakaolin reduced the total porosity for the specimens with low water to binder ratios in particular. To determine the optimal values of water to binder ratio and metakaolin content in producing high-strength and high-performance concrete we applied a multi-objective optimization, where several responses were simultaneously assessed to find the best solution for each parameter.

• Advances in concrete construction
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• v.4 no.2
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• pp.123-143
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• 2016

Use of heavy fuel fly ash (HFFA) (diesel and cracked fuel) for power generation in Saudi Arabia has generated and accumulated large quantities of HFFA as a byproduct. In this research, HFFA is studied with the emphasis on the utilization of this waste material in concrete blocks and asphalt concrete mixes. Two types of mixes, one with low and other with high cement content, were studied for concrete blocks. Different mixes having varying percentages of HFFA (0% to 25%), as cement/sand replacement or as an additive, were studied. The performance of concrete blocks is evaluated in terms of compressive strength, water absorption, durability and environmental concerns. The results showed that blocks cannot be cast if more than 15% HFFA is used; also there is a marginal reduction in the strength of all the mixes before and after being exposed to the sulfate solution for a period of ten months. HFFA is studied in asphalt concrete mixes in two ways, as an asphalt modifier (3&5%) and as a filler (50%) replacement, the results showed an improvement in stiffness and fatigue life of mixes. However, the stability and indirect tensile strength loss were found to be high as compared to the control mix due to moisture damage, indicating a need of using antistripping agents. On environmental concerns, it was found that most of the concerned elements are within acceptable limits also it is observed that lower concentration of barium is leached out with the higher HFFA concentrations, which indicates that HFFA may work as an adsorbent for this leaching element.

• Advances in concrete construction
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• v.5 no.6
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• pp.639-658
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• 2017

Very limited studies have been accomplished concerning the historical structures around Harran area. Collected mortar samples from the historic structures in the area were tested to explore their mechanical, chemical and mineralogical properties. Mortar samples from three different points of each historical structure were taken and specified in accordance with the related standards taking into consideration their mechanical, chemical and mineralogical properties. By means of SEM-EDX the presence of organic fibres and calcite, quartz, plagioclase and muscovite minerals has been examined. Additionally, by means of XRF analysis, oxide ($SiO_2$, $Al_2O_3$, and $Fe_2O_3$) percentages of mortar ingredients have been specified, also. According to the test results obtained, it was confirmed that the mortars had densities ranging between $1.51-2.10g/cm^3$, porosity values ranging between 8.89-35.38% and compressive strengths ranging between 5.02-5.90 MPa. Specimen HU, which has the highest durability and lowest water absorption and porosity, was the mortar taken from the most intact building in the mosque complex. This result is most likely due to the very little fine aggregate content of HU. In contrast, HUC mortars with a small amount of fine particles and brick contents yielded slightly lower compressive strengths. The interesting point of this study is the mineralogical analysis results and especially the presence of ettringite in these historic mortars linked to the use of pozzolanic materials. Survival of these historic structures in Harran Area through centuries of use and, also, having been subjected to many earthquakes can probably be explained by these properties of the mortars.

• Food Science of Animal Resources
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• v.41 no.4
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• pp.687-700
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• 2021

This study performed to evaluate the applicability of functional dairy food materials by comparing the calcium solubilization ability and anti-inflammatory effects of hydrolyzed casein protein. Commercial enzyme (Alcalase^®; Neutrase^®; Protamex^®; Flavourzyme^®) was added to the 10% casein solution to prepare the casein hydrolysates. Samples obtained every hour [1:200 (w/v)]. According to results of measuring the degree of hydrolysis (DH), all of four enzymatic hydrolysates increased rapidly from 30 to 40 min, and after 150 min, there were no change. Protamex^® and Neutrase^® had the highest DH compared to others enzymatic hydrolysates. After that, peptides obtained throughout a preparative liquid chromatography system. In the calcium solubility experiments, neutrase fraction (NF) 4 and NF7 showed similar activities with casein phosphopeptide (CPP). In vitro cell experiments showed that no cytotoxicity except for NF6. Also, the production of nitric oxide (NO) inhibited as the concentration of fraction samples increased. The cytokine (IL-1α, IL-6, and TNF-α) production was lower than lipopolysaccharide (+) group significantly. Therefore, the possibility of anti-inflammatory activity found in the hydrolyzed samples. According to the above experiments, NF3 and Protamex Fraction (PF) 3 selected. Amino acids selected throughout an AccQ-Tag system. As a result, 17 species of amino acids and several species of unknown amino acids identified. Both fractions had the highest content of phenylalanine. This study identified the potential of biologically active and functional peptides derived from casein that affect the food and dairy industry.

• Advances in concrete construction
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• v.11 no.5
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• pp.419-428
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• 2021

The pH of cement-based materials (CBMs) is an important factor for their durability, sustainability, and long service life. Currently, the use of supplementary cementitious materials (SCMs) is becoming mandatory due to economic, environmental, and sustainable issues. There is a decreasing trend in pH of CBMs due to incorporation of SCMs. The determination of numerical values of pH is very important for various low and high volume SCMs blended cement mortars for the better understanding of different defects and durability issues during their service life. In addition, the effect of cement hydration and pozzolanic reaction of SCMs on the pH should be determined at initial and later ages. In this study, the effect of low and high-volume fly ash (FA) and ground granulated ballast furnace slag (GGBFS) cement mortars in different curing conditions on their pH values has been determined. Thermal gravimetric analysis (TGA) was carried out to support the findings from pH measurements. In addition, thermal conductivity (k-value) and strength activity indices of these cement mortars were discussed. The results showed that pH values of all blended cement mortars were less than ordinary Portland cement (OPC) mortar in all curing conditions used. There was a decreasing tendency in pH of all mortars with passage of time. In addition, the pH of cement mortars was not only dependent on the quantity of Ca(OH)₂. The effect of adding SCMs on the pH value of cement mortar should be monitored and measured for both short and long terms.

• Advances in concrete construction
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• v.13 no.1
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• pp.71-81
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• 2022

Aluminosilicate materials as precursors are heterogenous in nature, consisting of inert and partially reactive portion, and have varying proportions depending upon source materials. It is essential to assess the reactivity of precursor prior to synthesize geopolymers. Moreover, reactivity may act as decisive factor for setting molar concentration of NaOH, curing temperature and setting proportion of different precursors. In this experimental work, the reactivities of two precursors, low calcium (fly ash (FA)) and high calcium (ground granulated blast furnace slag (GGBS)), were assessed through the dissolution of aluminosilicate at (i) three molar concentrations (8, 12, and 16 M) of NaOH solution, (ii) 6 to 24 h dissolution time, and (iii) 20-100℃. Based on paratermeters influencing the reactivity, different proportions of ternary binders (two precursors and ordinary cement) were activated by the combined NaOH and Na2SiO3 solutions with two alkaline activators to precursor ratios, to synthesize the geopolymer. Reactivity results revealed that GGBS was 20-30% more reactive than FA at 20℃, at all three molar concentrations, but its reactivity decreased by 32-46% with increasing temperature due to the high calcium content. Setting time of geopolymer paste was reduced by adding GGBS due to its fast reactivity. Both GGBS and cement promoted the formation of all types of gels (i.e., C-S-H, C-A-S-H, and N-A-S-H). As a result, it was found that a specified mixing proportion could be used to improve the compressive strength over 30 MPa at both the ambient and hot curing conditions.