• Advances in concrete construction
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• v.3 no.4
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• pp.317-331
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• 2015

This paper presents the effect of different micro-silica (MS) contents of 5, 10 and 15 wt.% as partial replacement of cement on mechanical and durability properties of high volume fly ash - recycled aggregate concretes (HVFA-RAC) containing 50% class F fly ash (FA) and 35% recycled coarse aggregate (RCA) as partial replacement of cement and natural coarse aggregate (NCA), respectively. The measured mechanical and durability properties are compressive strength, indirect tensile strength, elastic modulus, drying shrinkage, water sorptivity and chloride permeability. The effects of different curing ages of 7, 28, 56 and 91 days on above properties are also considered in this study. The results show that the addition of MS up to 10% improved the early age (7 days) strength properties of HVFA-RAC, however, at later ages (e.g. 28-91 days) the above mechanical properties are improved for all MS contents. The 5% MS exhibited the best performance among all MS contents for all mechanical properties of HVFA-RAC. In the case of measured durability properties, mix results are obtained, where 10% and 5% MS exhibited the lowest sorptivity and drying shrinkage, respectively at all ages. However, in the case of chloride ion permeability a decreasing trend is observed with increase in MS contents and curing ages. Strong correlations of indirect tensile strength and modulus of elasticity with square root of compressive strength are also observed in HVFA-RAC. Nevertheless, it is established in this study that MS contributes to the sustainability of HVFA-RAC significantly by improving the mechanical and durability properties of concrete containing 50%less cement and 35% less natural coarse aggregates.

• Fisheries and Aquatic Sciences
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• v.18 no.2
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• pp.151-158
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• 2015

We evaluated the effects of rice distillers dried grain (DDG) as a partial replacement for fish meal in the practical diet on growth performance, feed utilization, and body composition of juvenile olive flounder Paralichthys olivaceus. Six isonitrogenous and isocaloric diets were formulated to contain 0%, 7%, 14%, 21%, 28%, and 35% DDG (designated DDG0, DDG7, DDG14, DDG21, DDG28, and DDG35, respectively). Three replicate groups of juvenile olive flounder averaging $9.6{\pm}0.2g$ were fed one of the experimental diets to visual satiety twice daily for 8 weeks. Neither survival nor daily feed intake was affected by the dietary DDG levels. Weight gain of the flounder fed the DDG28 and DDG35 diets was lower than that of flounder fed the DDG7 diet. The feed efficiency of flounder fed the DDG28 diet was lower than that of flounder fed the DDG0, DDG7, and DDG14 diets. The protein efficiency ratio of flounder fed the DDG28 diet was lower than that of flounder fed the DDG7 diet. The proximate composition of muscle was not affected by the dietary DDG levels. The plasma contents of total protein, glucose, cholesterol, glutamate oxaloacetate transaminase, phospholipid, and triglyceride were not affected by the dietary DDG levels. The results of this experiment suggest that DDG has the potential to replace fish meal and could be used up to 21% DDG without any negative effects on the growth and feed utilization of juvenile flounder.

• Fisheries and Aquatic Sciences
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• v.17 no.1
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• pp.85-93
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• 2014

A 9-week feeding experiment was designed to test the effects of the dietary inclusion of distillers dried grain (DDG) on the growth performance, body composition, and antioxidant activity of juvenile rockfish Sebastes schlegeli. Five isonitrogenous and isocaloric diets were formulated to contain 0% DDG (DDG0), 7% and 14% DDG from rice (diets DDG-R7 and DDG-R14, respectively), as well as 7% and 14% DDG from rice and wheat flour (diets DDG-RW7 and DDG-RW14, respectively). Three replicate groups of juvenile rockfish averaging $68.0{\pm}0.4g$ were fed one of the diets to apparent satiation twice a day. Survival, weight gain, feed efficiency, and the protein efficiency ratio of fish were not affected by dietary DDG (P > 0.05). Proximate and amino acid compositions of the whole body were not affected by dietary DDG (P > 0.05). Plasma total protein, glucose, total cholesterol, glutamate oxaloacetate transaminase, glutamate pyruvate transaminase, phospholipid, and triglyceride were not affected by dietary DDG (P > 0.05). Radical scavenging activity on 1,1-diphenyl-2-picryl-hydrazyl (DPPH) in the plasma of rockfish fed the DDG-RW14 diet was higher than that of fish fed the DDG0 diet (P < 0.05). Hydroxyl radical scavenging activity in the liver of rockfish fed diets containing DDG was higher than that of fish fed the DDG0 diet (P < 0.05). Alkyl radical scavenging activity in the liver of rockfish fed the DDG-R7 diet was higher than that of fish fed the DDG0 diet (P < 0.05). These results suggest that DDG is a suitable ingredient for the partial replacement of wheat flour and can be used at a rate of up to 14% in the diet without incurring negative effects on the growth performance or body chemical composition of juvenile rockfish.

• Journal of the Korean Home Economics Association
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• v.39 no.1
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• pp.103-111
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• 2001

This study was attempted to investigate the effect of partial replacement of rice flour with black or brown rice flour on texture properties and retrogradation of Julpyun(Korean rice cake). In sensory evaluation, the Julpyuns replaced black or brown rice flour 20% had high score in color, flavor and overall acceptability not including mouthfeel. As the result of the measurement with texture analyzer, hardness, gumminess and chewiness of Julpyuns tended to decrease in proportion to the amount of black and brown rice flour in the formula. These resets implied that the degree of retrogradation of black and brown rice Julpyuns might be low. Julpyuns replaced with black rice were a little lower than those of brown rice in the hardness. In the retrogradation speed by Avrami,s equation, the rate constants of Julpyun replaced black and brown rice flour was lower than that of milled rice, restating in delay in firming.

• Structural Engineering and Mechanics
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• v.87 no.5
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• pp.499-516
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• 2023

To defend against harmful gamma radiation, new types of materials for use in the construction of heavyweight concrete (HWC) are still needed to be developed. This research introduces new materials to be employed as a partial replacement for fine aggregate (FA) to manufacture high-performance heavyweight concrete (HPHWC). These materials include hematite, black sand, ilmenite, and magnetite, with substitution ratios of 50% and 100% of FA. In this research, the hardening and fresh characteristics of HPHWC were obtained. Concrete samples' Gamma-ray linear attenuation coefficient was evaluated utilizing a gamma source of Co-60 through the thicknesses of 2.5, 5, 7.5, 10, 12.5, and 15 cm. High temperatures were studied for HPHWC samples, which were exposed to up to 700℃ for two hours. Energy-dispersive x-rays and a scanning electron microscope carried out microstructure analyses. Magnetite as an FA attained the lowest compressive strength of 87.1 MPa, but the best radiation protection characteristics and the highest density of 3100 kg/m³ were achieved. After 28 days, the attenuation efficiency of concrete mixtures was increased by 6.5% when fine sand was replaced with black sand at a ratio of 50%. HPHWC, which contains hematite, black sand, ilmenite, and magnetite, is designed to reduce environmental and health dangers and be used in medicinal, military, and civil applications.

• Korean Journal of Materials Research
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• v.34 no.1
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• pp.21-26
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• 2024

In this investigation, samples of the chemical (Hg_1-xPb_xBa₂Ca_1.8Mg_0.2Cu₃O_8+δ) were prepared utilizing a solid-state reaction technique with a range of lead concentrations (x = 0.0, 0.05, 0.10, and 0.20). Specimens were pressed at 8 tons per square centimeter and then prepared at 1,138 K in the furnace. The crystalline structure and surface topography of all samples were examined using X-ray diffraction (XRD) and atomic force microscopy (AFM). X-ray diffraction results showed that all of the prepared samples had a tetragonal crystal structure. Also, the results showed that when lead was partially replaced with mercury, an increase in the lead value impacted the phase ratio, and lattice parameter values. The AFM results likewise showed excellent crystalline consistency and remarkable homogeneity during processing. The electrical resistivity was calculated as a function of temperature, and the results showed that all samples had a contagious behavior, as the resistivity decreased with decreasing temperature. The critical temperature was calculated and found to change, from 102, 96, 107, and 119 K, when increasing the lead values in the samples from 0.0 to 0.05, 0.10, and 0.20, respectively.

• Journal of the Korean Recycled Construction Resources Institute
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• v.12 no.1
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• pp.72-81
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• 2024

In this study, DEIPA was used for enhancing cementitious performance of bottom ash replaced cement. By applying the partial or no-known crystal structure method to X-ray diffraction data, the amounts of amorphous bottom ash and calcium silicate hydrate(C-S-H) could be separated and quantified. In the sample without DEIPA, the bottom ash hardly reacted, resulting in low compressive strength. However, the addition of DEIPA not only altered the hydration behavior of the cement but also enhanced the pozzolanic reaction between bottom ash and calcium hydroxide, leading to the generation of additional C-S-H. This resulted in high compressive strength not only in the early stages but also in the later stages. Therefore, with the addition of DEIPA during the pulverization of the bottom ash, the reactivity of the bottom ash was significantly improved. Hence, there is potential in the development of bottom ash replacement cement.

• Advances in nano research
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• v.16 no.3
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• pp.217-229
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• 2024

This paper presents results of visual analysis of cracks formation and propagation of concretes made of quaternary binders (QBC). A composition of the two most commonly used mineral additives, i.e. fly ash (FA) and silica fume (SF) in combination with nanosilica (nS), has been proposed as a partial replacement of the cement. The principal objective of the present study is to achieve information about the effect of simultaneous incorporation of three pozzolans as partial replacement to the OPC on the fracture processes in concretes made from quaternary binders (QBC). The modern and precise non-contact measurement method (NCMM) via digital image correlation (DIC) technique was used, during the studies. In the course of experiments it was established that the substitution of OPC with three pozzolans including the nanoadditive in FA+SF+nS FA+SF+nS combination causes a clear change of brittleness and behavior during fractures in QBCs. It was found that the shape of cracks in unmodified concrete was quasi-linear. Substitution of the binder by SCMs resulted in a slight heterogeneity of the structure of the QBC, including only SF and nS, and clear heterogeneity for concretes with the FA additive. In addition, as content of FA rises throughout each of QBC series, material becomes more ductile and shows less brittle failure. It means that an increase in the FA content in the concrete mix causes a significant change in fracture process in this composite in comparison to concrete with the addition of silica modifiers only.

• Childhood Kidney Diseases
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• v.7 no.1
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• pp.86-90
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• 2003

An 8-month-old male infant presented with persistent, gross, orange-colored crystals in his urine. His physical and neurological development was normal. Laboratory study showed hyperuricemia, hyperuricosuria and urate crystaluria. He was determined to have partial hypoxanthine-guanine phosphoribosyl transferase(HPRT) deficiency. The molecular genetic analysis revealed a missense mutation in the patient's HPRT gene. By sequencing the patient's cDNA, we identified an A-to-G transition at nucleotide 239, resulting in the replacement of Aspartate with Glycine at amino acid 80 in the HPRT. To our knowledge, this mutation has not previously been reported. Our patient is now being placed on allopurinol therapy, and has had no problem since. Partial HPRT deficiency has been known to cause recurrent acute renal failure without the phenotypic features of Lesch-Nyhan syndrome. Therefore, we think that early diagnosis and treatment are very crucial in preventing acute renal failure.

• Computers and Concrete
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• v.17 no.3
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• pp.337-351
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• 2016

This paper presents the properties of pervious concrete containing high-calcium fly ash. The water to binder ratios of 0.19, 0.22, and 0.25, designed void ratios of 15, 20, and 25%, and fly ash replacements of 10, 20, and 30% were used. The results showed that the use of fly ash as partial replacement of Portland cement enhanced the mixing of paste resulting in a uniform mix and reduced amount of superplasticizer used in the mixture. The compressive strength and flexural strength of pervious concrete were slightly reduced with an increase in fly ash replacement level, while the abrasion resistance increased due mainly to the pozzolanic and filler effects. The compressive strength and flexural strengths at 28 days were still higher than 85% of the control concrete. The aggregate size also had a significant effect on the strength of pervious concrete. The compressive strength and flexural strength of pervious concrete with large aggregate were higher than that with small aggregate.