• Journal of Biosystems Engineering
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• v.36 no.4
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• pp.267-272
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• 2011

The latent heat of vaporization in rough rice, brown rice, white rice and rice hull was calculated by Clausius-Clapeyron equation, which does not require complex constraints as in Othmer method. Equilibrium relative humidity and ratio of the latent heat of vaporization with ln$P_{\upsilon}$ and ln$P_S$ were estimated with moisture contents ranging from 10% (d.b.) to 36% (d.b.) with 2% (d.b.) increment and temperatures ranging from $10^{\circ}C$ to $50^{\circ}C$ with $2.5^{\circ}C$ increment. An empirical equation for calculating the latent heat of vaporization in rice was developed as a function of moisture content and temperature. The equation agreed well with the calculated results. The ratio for latent heat of vaporization were the greatest for white rice while they were similar among rough rice, brown rice and rice hull.

• Korean Journal of Poultry Science
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• v.33 no.1
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• pp.65-80
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• 2006

Ash amendment to manure holds potential as a method to neutralize manure for reducing odor and reduce phosphorus (P) solubility in runoff from fields where manure has been applied. This review focuses on the literature published about ash characteristics and their environmental uses. There is no uniform physico-chemical definition of the selected ashes (coal fly ash-CFA, wood ash-WA, and rice hull ash-RHA) used in various studies. These ashes vary greatly in their acidity (pH<6.0) or alkalinity (pH>12.5) based on the conditions at which they were farmed and the composition of the ash source. CFA amendment to manure reduced manure-P solubility and application of CFA amended manure to agricultural soils is a method to improve water quality WA may prove to be a valuable manure odor control amendment since WA contains a high level of carbon. A major biomass source is rice hull (husk) which provides an ash source (RHA). The .ice hull and RHA are sources of silica, compromising about 20% and 60%, respectively. So far research has been directed at the use of CFA, WA and RHA as soil amendments, but there is potential use of these materials as manure additives to sequester P and reduce odors.

• Korean Journal of Organic Agriculture
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• v.21 no.3
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• pp.413-422
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• 2013

This experiment was conducted to clarify the effect of double layer mulching on reducing the labor required to weed control and Leaf sheath training of the garlic cultivation. Six mulching methods(non-mulching, transparent P.E., rice hull+transparent P.E., sawdust+transparent P.E., rice straw+transparent P.E., black P.E. film+ transparent P.E.) were used for the experiment, and transparent P.E film was removed on April 10. Weed occurrence was in the order of black P.E. film< transparent P.E

• Journal of the Korea Organic Resources Recycling Association
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• v.18 no.1
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• pp.110-118
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• 2010

Supercritical treatment of liquefaction technology for rice hull was investigated the biomass conversion rate and evaluated its crude oil in respect to feasibility of burner in order to heat the green house. The reaction was carried out in a 5,000 mL liquefaction system with dispenser and external electrical furnace. Raw materials (160 g) of rice hull and 3,000 mL of different solvents were fed into the reactor. It was observed that the maximum crude oil yield was about 84.4 % with 1-butanol. The calorific value of crude oil from ethanol solvent were 7,752 kcal/kg. Furthermore, in case study of co-solvent with ethanol and bulk-glycerol, it observed that more than 80 % of rice hull was decomposed and liquefied in its solvent at $315{\sim}326^{\circ}C$ for 30 min. For the development of applicable bio-fuel from rice hull, it was considered that its feasibility is necessary to be carried out for co-solvent soluble portions. Regarding to utilize the crude oil into burner as fuel, it was observed that its calorific value was lower at approximately 24 % than the diesel. Also, flame length from crude oil at lower temperature was decreasing due to incomplete incineration. The temperature of warm wind on the burner was maintained between 63 and $65^{\circ}C$, and the temperature of emission line was appeared at $350{\sim}380^{\circ}C$.

• Journal of Bio-Environment Control
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• v.10 no.2
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• pp.101-105
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• 2001

Plant roots are affected by the root zone environment rather than substrate material itself. It is important to provide a suitable environment for the roots by amending the substrate and adjusting supply of the nutrient solution. In an expanded rice hull substrates, 1.5 L nutrient solution was supplied on each day at different frequency. In rice hull substrate, plant growth and yield were the greatest in the treatment where a 1.5L nutrient solution was supplied as 24 equal aliquots, wheres in perlite substrate plant growth and yield were the greatest in the treatment with 16 aliquots. Nitrogen deficiency symptoms caused by early decomposition of rice hulls by microorganisms was recovered by increasing solution EC from 1.7 to EC 2.0 dS.m$^{-1}$ for 25 days after planting. Plant growth and yield increased in the treatment of Ec 3.0 dS.m$^{-1}$ , but the cause for this increase is not clear.

• Korean Journal of Medicinal Crop Science
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• v.17 no.6
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• pp.415-420
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• 2009

This study was carried out to select economical byproduct composts as the substitute for the traditional organic fertilizer, Yacto, in the cultivation of ginseng seedlings, and to investigate the application method of a selected compost. Among tested byproduct composts, popped rice hull compost was the best substitute for Yacto, while the application of domestic animal manure composts resulted in red skinned roots of ginseng seedlings. Optimal mixing ratio of the popped rice hull compost with virgin soil (fine sand) were 3~4 : 1 in bulk, showing the same root yield compared to that of conventional seedbed soil. When the popped rice hull compost was lower than $1\;{\pm}\;0.1%$ in nitrogen content, the expeller cake of oil seed was added to seedbed soil to rise nitrogen content until $1\;{\pm}\;0.1%$.

• Korean Journal of Soil Science and Fertilizer
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• v.49 no.2
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• pp.181-193
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• 2016

This experiment was conducted to evaluate the effect of carbonized rice hull (CRH) application on soil carbon storage and $N_2O$ emissions from upland soil. It was used at different rates of 0, 5, 10 and $20Mg\;ha^{-1}$. During the Chinese cabbage cultivation, several soil chemical characteristics such as soil moisture, temperature and soil carbon were observed. Also, $CO_2$ and $N_2O$ emissions were monitored. Soil organic matter contents slightly increased with carbonized rice hull applied in all the treatments. The soil carbon contents with application rate of 0, 5, 10 and $20Mg\;ha^{-1}$ were 0, 1.3, 1.2 and $2.6g\;kg^{-1}$, respectively. It was observed that soil carbon content was higher with increasing CRH application rate. Total nitrogen contents of soil applied with CRH relatively decreased with the course of time. However, $NO_3$-N contents in the soil with CRH application rate of 5, 10 and $20Mg\;ha^{-1}$ were 28.6, 25.7 and $21.5mg\;kg^{-1}$ at the end of experiment, respectively. $CO_2$ emission at the $5Mg\;ha^{-1}$ application of CRH was higher about 18.9% than non-treatment, whereas those of $10Mg\;ha^{-1}$ and $20Mg\;ha^{-1}$ treatment were lower 14.4% and 11.8% compared to non-treatment, respectively. Also, it was shown that $N_2O$ emission reduced by 19.9, 28.3 and 54.0% when CRH was applied at 5, 10 and $5Mg\;ha^{-1}$, respectively.

• Korean Journal of Agricultural Science
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• v.43 no.2
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• pp.176-185
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• 2016

This research was conducted to evaluate various levels of dolomitic lime incorporated as pre-planting fertilizers on the growth of red-leaf lettuce. To achieve this, three root media were formulated by mixing coir dust with expanded rice hull (CD+ERH, 8:2, v/v), carbonized rice hull (CD+CRH, 6:4, v/v), and ground pine bark (CD+GRPB, 6:4, v/v). During formulation, equal amounts of essential nutrients, except dolomitic lime, were incorporated into all root media and the levels of dolomitic lime were varied from 0 to $7.5g\;L^{-1}$ at 1.5 g increments. Seedlings of red-leaf lettuces at the 3rd leaf stage were transplanted into each medium treatment. Crop growths were measured 5 weeks after transplant and soil solutions were collected every week and analyzed for pH, EC, and nutrient concentrations. The treatments showing the heaviest fresh and dry weights in CD+ERH, CD+CRH, and CD+GRPB were 4.5 g, 4.5 g, and $7.5g\;L^{-1}$ of dolomite, respectively. The pHs of three root media yielding the highest crop growths were in the ranges of 6.4 to 7.1. These ECs in CD+CRH medium were around $1.0dS\;m^{-1}$ higher than those of CD+ERH and CD+GRPB when application rates of dolomitic lime were equal. $K^+$ concentrations were higher than $Ca^{+2}$ and $Mg^{+2}$ concentrations until week 2 in three root media. But $Ca^{+2}$ and $Mg^{+2}$ concentrations were higher than $K^+$ concentrations after week 3 in all root media. The concentrations of $PO_4{^{-3}}$ in all root media got abruptly lower until week 2. These results indicate that appropriate levels of dolomitic lime, as pre-planting nutrient charge fertilizers in CD+ERH and CD+GRPB media, are 4.5 and $7.5g\;L^{-1}$, respectively.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.5
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• pp.696-701
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• 2016

This study was conducted to evaluate the effects of heat treatment and germination on tricin and tricin 4'-O-(threo-${\beta}$-guaiacylglyceryl) ether (TTGE) formation from rice hull (Oryza sativa L.). Heat treatments were conducted at $80{\sim}140^{\circ}C$ for 1~5 h. Germination periods were 1~6 days at $37^{\circ}C$. Germinated rough rice extracts were classified as non-filtrated, filtrated, and residue after filtration. For heat treatment, the highest contents of tricin and TTGE were 253.12 and $208.39{\mu}g/g$ at $130^{\circ}C$ after 1 h, respectively. For germination, the highest contents of tricin and TTGE in rice hull were 118.20 and $95.37{\mu}g/g$ after 2 days, respectively. In the germinated rough rice extract treatment, the highest contents of tricin and TTGE were 361.76 and $308.08{\mu}g/g$, respectively, in residue after filtration of germinated rice extract for 6 days. Therefore, the optimum conditions for tricin and TTGE formation were heat treatment at $130^{\circ}C$ for 1 h, germination for 2 days, and addition of residue after filtration of germinated rough rice extract for 6 days.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.6
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• pp.775-780
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• 2011

We investigated the changes in antioxidant and angiotensin converting enzyme I (ACE) inhibitory activity in different parts of 'Ilpum' (Oryza sativa L.) rough rice before and after germination. Rough rice, either before or after germination, were separated into hull, brown rice, or sprout, and then extracted with distilled water and 70% ethanol. After germination, the total polyphenol contents of the distilled water extract of the brown rice was higher than before germination (5.84 and 1.67 mg/g, respectively). The DPPH radical scavenging activity on the unseparated rough rice ethanol extract increased from 22.95% before germination to 31.32% after germination, but it decreased in both the hull and brown rice extracts. The ABTS radical scavenging activity was highest in the sprout extract with a value of 4.41 mg AA eq/g. The reducing power of the brown rice ethanol extract increased from 0.32 before germination to 0.45 after germination. The ACE inhibitory activity of the in hull ethanol extract increased after germination. These results indicate that antioxidant capacity increases in the hull and sprout after germination could be considered having significant health benefits.