• Advances in concrete construction
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• v.11 no.1
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• pp.73-80
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• 2021

Rice Husk Ash (RHA) geopolymer paste activated by sodium aluminate were characterized by X-ray diffractogram (XRD), scanning electron microscope (SEM), energy dispersion X-Ray analysis (EDAX)and fourier transform infrared spectroscopy (FTIR). Five series of RHA geopolymer specimens were prepared by varying the Si/Al ratio as 1.5, 2.0, 2.5, 3.0 and 3.5. The paper focuses on the correlation of microstructure with hardened state parameters like bulk density, apparent porosity, sorptivity, water absorption and compressive strength. XRD analysis peaks indicates quartz, cristobalite and gibbsite for raw RHA and new peaks corresponding to Zeolite A in geopolymer specimens. In general, SEM micrographs show interconnected pores and loosely packed geopolymer matrix except for specimens made with Si/Al of 2.0 which exhibited comparatively better matrix. Incorporation of Al from sodium aluminate were confirmed with the stretching and bending vibration of Si-O-Si and O-Si-O observations from the FTIR analysis of geopolymer specimen. The dense microstructure of SA2.0 correlate into better performance in terms of 28 days maximum compressive strength of 16.96 MPa and minimum for porosity, absorption and sorptivity among the specimens. However, due to the higher water demand to make the paste workable, the value of porosity, absorption and sorptivity were reportedly higher as compared with other geopolymer systems. Correlation regression equations were proposed to validate the interrelation between physical parameters and mechanical strength. RHA geopolymer shows comparatively lower compressive strength as compared to Fly ash geopolymer.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.53 no.4
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• pp.382-387
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• 2008

This study was conducted to determine the effect of rice bran on rice yield, grain quality and weeds control depending on applying times. The redox potential was severely reduced $4{\sim}7$ days after rice bran application but that of conventional practice was reduced 17 days after transplanting. During the decomposing of the rice bran in the water, the dissolved oxygen in the water was exhausted right away after rice bran application. The dry weight of weed increased as the rice bran application time was delayed that weed dry weights increased by 138% in applying before puddling (ABP), 219% in 5 DAT (days after transplanting), 300% in 7 DAT and 619% in 9 DAT compared to conventional practice. The rice yield reduced remarkably in rice bran treatments after transplanting compared to conventional practice and applying before puddling. In the rice quality, the head rice ratio in the rice bran treatment was higher than that in conventional practice, and its protein content decreased. The results confirm that the rice bran application make the rice palatability higher, but there was no difference in rice qualities depending on application times.

• Korean Journal of Environmental Agriculture
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• v.19 no.5
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• pp.401-418
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• 2000

1. Production of the artificial zeolite from coal ash Coal fly ash is mainly composed of several oxides including $SiO_2$ and $Al_2O_3$ derived from inorganic compounds remained after burning. As minor components, $Fe_2O_3$ and oxides of Mg, Ca, P, Ti (trace) are also contained in the ash. These components are presented as glass form resulting from fusion in the process of the combustion of coal. In other word, coal ash may refer to a kind of aluminosilicate glass that is known to easily change to zeolite-like materials by hydrothermal reaction. Lots of hot seawater is disposing near thermal power plants after cooling turbine generator periodically. Using seawater in the hydrothermal reaction caused to produce low price artificial zeolite by reduction of sodium hydroxide consumption, heating energy and water cost. As coal ash were reacted hydrothermally, peaks of quartz and mullite in the ash were weakened and disappeared, and new Na-Pl peaks were appeared strengthily. Si-O-Si bonding of the bituminous coal ash was changed to Si-O-Al (and $Fe^{3+}$) bonding by the reaction. Therefore the produced Na-Pl type zeolite had high CEC of 276.7 $cmol^+{\cdot}kg^{-1}$ and well developed molecular sieve structure with low concentration of heavy metals. 2. Utilization of the artificial zeolite in agro-environment The artificial zeolite(1g) could remove 123.5 mg of zinc, 164.7 mg copper, 184.4 mg cadmium and 350.6 mg lead in the synthetic wastewater. The removability is higher 2.8 times in zinc, 3.3 times in copper, 4.7 times in cadmium and 4.8 times in lead than natural zeolite and charcoal powder. When the heavy metals were treated at the ratio of 150 $kg{\cdot}ha^{-1}$ to the rice plant, various growth inhibition were observed; brownish discoloration and death of leaf sheath, growth inhibition in culm length, number of panicles and grains, grain ripening and rice yield. But these growth inhibition was greatly alleviated by the application of artificial zeolite, therefore, rice yield increased $1.1{\sim}3.2$ times according to the metal kind. In addition, the concentration of heavy metals in the brown rice also lowered by $27{\sim}75%$. Artificial Granular Zeolites (AGZ) was developed for the purification of wastewater. Canon exchange capacity was 126.8 $cmol^+{\cdot}kg^{-1}$. AGZ had Na-Pl peaks mainly with some minor $C_3S$ peaks in X-ray diffractogram. In addition, AGZs had various pore structure that may be adhere the suspended solid and offer microbiological niche to decompose organic pollutants. AGZ could remove ammonium, orthophosphate and heavy metals simultaneously. Mixing ratio of artificial zeolite in AGZs was related positively with removal efficiency of $NH_4\;^+$ and negatively with that of $PO_4\;^{3-}$. Root growth of rice seedling was inhibited severely in the mine wastewater because of strong acidity and high concentration of heavy metals. As AGZ(1 kg) stayed in the wastewater(100L) for 4days, water quality turned into safely for agricultural usage and rice seedlings grew normally.

• Korean Journal of Environmental Agriculture
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• v.14 no.1
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• pp.1-6
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• 1995

This experiment was carried out to clarify the evapotranspiration and water use efficiency in rice plant canopy. Two rice cultivars, Daechungbyo(japonica type) and Samgangbyo(Tongil) were planted on the field of Suwon Weather Forecast Station in 1989. Evapotranspiration, dry matter production and leaf area of rice plant were measured to investigate the water use efficiency. There was significant correlation between cumulative evapotranspiration and dry matter production of aboveground. The parameter of linear regression was 4.13. The ratio of cumulative top dry matter production per cumulative evapotranspiration was increased until $5.5{\sim}5.9$ leaf area index. The de Wit's "m" value revealed maximum record at heading-flowering stage. At the harvest, the values were ranged from 175.5 to 191.7. The parameter of cumulative solar radiation to dry matter production was $1.011{\sim}1.248$. The evapotranspiration ratio(g.water/g.DW) of Samgangbyo(278) was higher than that of Daechungbyo (299.9). The efficiency of evapotranspiration(g.DW/g. water) was 1.58 in Daechungbyo and 1.98 in Samgangbyo.

• Korean Journal of Soil Science and Fertilizer
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• v.20 no.2
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• pp.123-129
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• 1987

In order to find out more effective countermeasures against growth damage of paddy rice due to the irrigation of livestock waste water, pot experiments were carried out in 1985 and 1986. Experiment I conducted in 1985 was to find out the effects of irrigation control and application of ameliorators to paddy soil with irrigation of animal waste water. Experiment II conducted in 1986 was to find out the amounts of wollastonite to be applied. The results obtained were as follows. Experiment I ; Rice yields were higher in the treatment of continuously submersion until harvest than in that of intermittent irrigation. The yield was also increased with the application of soil ameliorators and it showed higher increase in the treatment of zeolite and wollastonite. Nitrogen contents in plant were increased with the nitrogen application and more amounts of irrigation of waste water, but they were considerably decreased with the application of soil ameliorators. Experiment II ; Rice yields were increased with the application of wollastonite and the optimum level of wollastonite for maximum yield in condition of 3.0 g/pot of nitrogen application was belived to be 60g/pot. The increment of yield by the application of wollastinte was though to be due to increase of No. of grains per panicle and ripening ratio. Steriled neck occurred by rice disease such as rice blast was increased with increasing the amounts of nitrogen application and nitrogen contained in irrigated waste water but that was remarkably decreased with the application of wollastonite.

• Korean Journal of Environmental Agriculture
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• v.27 no.3
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• pp.225-230
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• 2008

Objective of this study was to access the environmental impacts of the use of discharge water from municipal waste water treatment plant as alternative irrigation resources during drought season for rice cultivation. For the field experiments, it was observed that plant growth and yield characteristics at 20 days of alternative irrigation period with application of FAST (fertilizer application based on soil test) 50% were relatively the same as the control. For the surface water quality, it appeared that $EC_i$ (electrical conductivity of irrigation water) and SAR (sodium adsorption ratio) values of DMWT (discharge waters from municipal wastewater treatment plant) irrigation were twofold higher than those of ground water irrigation as the control regardless of fertilization levels. For the irrigation periods, there were not significantly difference between 10 and 20 days of treatments, but $EC_i$ and SAR values of surface water were highest at 30 days of irrigation periods at initial rice growing stages. Generally, $EC_i$ values of percolation water in all the treatments were gradually increasing until 30days after irrigation, and then decreasing to harvest stage. Overall, it might be considered that there was possibility to irrigate DMWT with application of FAST 50% for 20 days of drought periods at rice transplanting season. Furthermore, efficiency rate of alternative irrigation water for 20 days of drought period was 32.7% relative to the total annual irrigation water for rice cultivation.

• Applied Biological Chemistry
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• v.37 no.4
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• pp.266-271
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• 1994

In order to investigate the effects of the mixing ratio of rice on Doenjang, Meju Doenjang and Koji Doenjang were prepared respectively with oaring mix ratio of raw materials. The following results were obtained, after fermentation of up to 3 months. Significant differences between the kinds of Doenjang were not found in moisture and salt contents. Protein solubility $(water\;soluble\;nitrogen/total\;nitrogen{\times}100)$ was $32{\sim}50%$ and $14{\sim}24%$ in Koji Doenjang and Meju Doenjang, respectively. Protein digestibility $(formol\;nitrogen/total\;nitrogen{\times}100)$ was similar to the tendency of protein solubility. Reducing sugar content was $5{\sim}6%$ in Meju Doenjang, while $19{\sim}21%$ in Koji Doenjang. As the mixing ratio of rice increased, reducing sugar content also increased. Sensory evaluation showed that Koji Doenjang was desirable than Meju Doenjang and the mixing ratio of 20% rice was recommened for Koji Doenjang.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.2
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• pp.271-279
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• 2016

The aim of this study was to evaluate the potential of natural humectants such as honey and rice syrup to replace sorbitol in the production of restructured duck jerky. Each humectant was mixed at 3%, 6%, and 10% (wt/wt) concentrations with the marinating solution. The values of water activity and the moisture-to-protein ratio of all of the samples were maintained below 0.75. Jerky samples treated with honey retained more moisture than those exposed to other treatments. Among all samples, those treated with 10% sorbitol produced the highest processing yield and the lowest shear force values. The highest $L^*$ value and the lowest $b^*$ value were observed for the sorbitol-treated sample, followed by the rice syrup- and honey-treated samples. Duck jerky samples treated with 10% honey showed the highest scores for the sensory parameters evaluated. The overall acceptability scores of samples treated with rice syrup were comparable with those of samples treated with sorbitol. Microscopic observation of restructured duck jerky samples treated with honey showed stable forms and smaller pores when compared with other treatments.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.52 no.4
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• pp.387-392
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• 2007

The effect of mixed treatments of wood vinegar and sulfonylurea-based herbicides on weed control, yield and yield components, and quality of rice was investigated. Two herbicides were tested namely: imazosulfuron-ethyl+thiobencarb[ethyl-1-(2-chloroimidazo[1,2-$\alpha$]pyridin-3-ylsulfonyl)-3-(4,6-dimethoxypyrimidin-2-yl) urea+S-4-chlorobenzyl diethyl(thiocarbamate)], and bensulfuronmethyl+butachlor [methyl $\alpha$-[(4,6-dimethoxypyrimidin-2-ylcarbamoyl)sulfamoyl]-o-toluate+N-butoxymethyl-2-chloro-2',6'-diethylacetanilide]. The experiment was carried out in a randomized complete block design with 3 replications and 5 treatments. Treatments used were recommended(RH: 100%) and half-recommended(HRH: 50%) application rates of each herbicide. Half-recommended application rates were combined with 1 mL wood vinegar $500mL\;water^{-1}$(500) and 1 mL wood vinegar $1000mL\;water^{-1}$(1000) wood vinegar. Plots for no herbicide treatments were also prepared and used as control. Results showed that wood vinegar significantly increased efficacy of HRH in bensulfuron-methyl+butachlor while high efficacy was already obtained in HRH treatment of imazosulfuron-ethyl+thiobencarb. Wood vinegar did not improve the efficacy of imazosulfuron-ethyl+thiobencarb but improved rice yield. Significantly similar rice yields were obtained in the HRH+1000 WV and RH treatments of both herbicides. There were no significant variations in the yield components among the treatments; however, differences in yield can be attributed to the variations in the spikelet number and ripening ratio. Data on rice quality analysis did not show clear trend on the effects of the treatments on grain appearance and nutritional quality.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.2
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• pp.141-145
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• 1997

The long wave infrared which is ranged to 4～1, 000 ${\mu}{\textrm}{m}$ is a kind of electromagnetic wave, and the wave is being absorbed by higher plant easily. The absorbed wave in the plant promotes the metabolism of plant cell by way of resonance with the water molecules of plant cell. This experiment was carried out to determine the effect of long wave infrared radiation ceramic on growth of rice seedling, and to make the optimum mixture rate of ceramic powder when ceramics was mixed with bed soil at 4, 8, 12, 16％ levels for machine transplanting. The results of this study indicate that the growth of the seedling significantly higher in the treatment sites than that of control sites. However, there was no significant differences in dry matter weight between the treatment and control sites. At the 9.6％ mixing ratio, the highest growth of rice seedling was found.