• Resources Recycling
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• v.2 no.4
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• pp.17-22
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• 1993

SiC whiskers were synthesized from rice hulls and activated carbon by carbothermal reduction method. The effects of gases and various additives were studied. Carbothermal reduction to produce SiC whiskers was conducted at $1450^{\circ}C$ and the synthesized SiC whiskers were examined using SEM and XRD. The length of whiskers is increased with the increases of $H_2$concentration and total gas flows. The most favorable form of SiC whiskers couble be obtained in the following experimental conditins : Ar : $H_2$=300:45(ml/min), $SiO_2$(inrice hulls): $CaF_2$=1:0.5:0.5(mole ratio) and the addition of Ni flakes ($1{\times}1$mm).

• BMB Reports
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• v.34 no.4
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• pp.310-315
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• 2001

The uneven distribution of acidic and basic chitinases in different parts of rice seed, and also the characterization of hull-specific chitinases, are reported here. After extraction of chitinases from polished rice, bran, and rice hulls, the chitinases were separated into acidic and basic fractions, according to their behavior on an anion exchanger column. Both fractions from different parts of rice seed showed characteristic activity bands on SDS-PAGE that contained 0.01% glycol chitin. The basic chitinases from rice hulls were further purified using chitin affinity chromatography. The chitinase, specific to rice hulls (RHBC), was 88-fold purified with a 1.3% yield. RHBC has an apparent molecular weight of 22.2 kDa on SDS-PAGE. The optimal pH and temperature were 4.0 and $35^{\circ}C$, respectively. With [$^3H$]chitin as a substrate, RHBC has $V_{max}$ of 13.51 mg/mg protein/hr and $K_m$ of 1.36 mg/ml. This enzyme was an endochitinase devoid of ${\beta}$-1,3-glucanase, lysozyme, and chitosanase activities.

• Journal of Navigation and Port Research
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• v.43 no.5
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• pp.328-334
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• 2019

Underwater architecture in providing a comfortable living space underwater is mandated to survive prevailing environmental loads, especially hydrostatic ambient water pressure exerted on the structure of individual habitat hulls at depth and hydrodynamic fluctuation of external forces that perturb the postural equilibrium and mooring stability of the underwater housing system, for which the design including the hull shape and mooring system constraint the responses. In this study, the postural stability of a proposed underwater floating housing system with three vertically connected ellipsoidal-shape habitat hulls of different sizes are theorized and calculated for hydrostatic stability, using MATLAB in the volumetric integration of a hull and the weight of operational loads under assumed scenarios. The assumptions made in the numerical method to estimate the stability of the habitat system include the fixed weight of the hulls, and their adjustable loads within operational limits for the set meteorological oceanic conditions. The purpose of this study was to numerically manipulate a) The buoyancy and b) The adjusted center of mass of the system within the range of designed external and internal load changes, by which the effective mooring system capability and postural equilibrium requirements were argued with the quantitative analysis.

• Composites Research
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• v.36 no.6
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• pp.448-453
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• 2023

This paper explores developing sustainable 3D printing filaments using organic soybean hulls mixed with polylactic acid (PLA). The study experiments with various particle sizes and mixing ratios, examining the physical and mechanical properties of the resulting filaments. Results show that smaller soybean hull particles and specific mixing ratios enhance the filament's quality while maintaining PLA's characteristics. This research signifies a step towards environmentally friendly 3D printing materials, offering a viable alternative to conventional filaments and addressing ecological concerns in the industry.

• Journal of the Society of Naval Architects of Korea
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• v.61 no.1
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• pp.61-67
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• 2024

A naval mine is an effective weapon system implemented for defending defends ports and seas. A mine is an underwater weapon that poses a great threat to ships sailing over the sea from shallow areas. Most of the influence-type naval mines detect magnetic field signals from ships and determine the final time of fire. Therefore, the level of underwater electro-magnetic signatures of ships is a key requirement for determining the survival of ships in wartime situations where mines are emplaced. The main reason why the high manganese steel is attracting attention for naval ship hulls is its nature as a non-magnetic steel. The non-magnetic hull does not generate electro-magnetic signatures; thus, it has the advantage improving the stealth of the ship. In this paper, I examine whether this material can be applied in the hulls material of naval ships that must be ableto reduce underwater electro-magnetic signatures by considering the non-magnetic characteristics of the first developed high manganese steel in the world.

• Composites Research
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• v.37 no.3
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• pp.150-154
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• 2024

In this study, nanofibrillated cellulose was extracted from soybean hulls - a by-product of soybeans - and compared with soybean hull nanofibrillated cellulose obtained by using other nanofibrillated methods. Dry soybean hulls were ground into prepare micrometer-sized powders, from which microcellulose was isolated using NaOH and HCl. The nanometer-sized cellulose was successfully extracted through ultrasonic dispersion and ball milling. The soybean hull nanofibrillated cellulose exhibited a diameter of 60-100 nm and a length of 0.3-1.0 ㎛, which matches the diameter of soybean nanofibrillated cellulose made by other nanofibrillated methods but is significantly shorter in length.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.11 no.1
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• pp.69-75
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• 2013

The recovery of Zr from Zircaloy-4 (Zry-4) cladding hulls was demonstrated to investigate the effect of the oxidation process on the reaction rate of the chlorination reaction. In chlorination reaction experiments performed for 6 h, where reaction products were collected every 2 h, it was observed that a significant decrease in the reaction rate was caused by the oxidation process ($500^{\circ}C$, 10 h under an air atmosphere) within the reaction period of 0 - 2 h. The amount of reaction residue increased from 0.95 to 1.65wt% of initial weights in the fresh and Zry-500-10 (Zry-4 hulls oxidized at $500^{\circ}C$ for 10 h under an air atmosphere) hulls, respectively. The purity of the recovered Zr was identical at 99.61wt% for the fresh Zry-4 and Zry-500-10 hulls. Quantitative analysis of the chlorination reaction rate was performed by varying the reaction time from 0.5 to 1.0, 2.0, and 4.0 h. The fitting results showed that the relationship between weight loss and reaction time can be interpreted by a linear line with a slope of 23.35wt%/h for the fresh Zry-4 case, while two linear lines were necessary to fit the results of Zry-500-10. In addition, the slope values were 17.12 and 27.16wt%/h for (0 - 20) and (20 - 100)wt% loss regions, respectively.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.spc1
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• pp.175-180
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• 2005

This study was carried out to determine total contents of phenol and flavonoid in common and tartary buckwheat for the purpose of developing new kind of functional food with buckwheat materials. Total content of phenol and flavonoid in seeds of tartary buckwheat were higher than that of common buckwheat. It showed same tendency in groats and hulls. Total content of phenol and flavonoid in groats showed higher than hulls in tartary buckwheat while those of hulls was a little higher than groats in common buckwheat seed. Rutin content in common buckwheat was higher in odor of the hulls (25.2 mg/100 g)>dehulled seed(19.8 mg/100 g)>groats (12.8mg/100 g). But tartary buckwheat was higher in oder of the groats(2042.1 mg/100 g)>dehulled seed (1375.8 mg/100 g)>hulls(138.7 mg/100 g). Flavanol content in dehulled seeds of the tartary and common buckwheat did not show the difference. However, flavanol contents in leaf, stem and spouts of tartary buckwheat were respectively higher than in those of common. Among the flavanols, catechin content was highest in all plant parts of their buckwheat and also was higher in odor of epicatechin>epicatechingallate. However, epicatechingallate content in sprouts of both buckwheat species was about 30-40 times higher than seeds.

• Korean Journal of Food Science and Technology
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• v.6 no.3
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• pp.147-157
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• 1974

This study was undertaken to observe the effect of sesame in the diet of rats (Splague Dowley). Comparisons were made of weight gains, organ weights and the cholesterol, phospholipid and triglyceride content of the blood serum and liver tissue. Rats weighing 67-80 g were used for the study, while rats weighing 160-165 g were used in the study. In the both studies, the experimental animals were fed on sesame mixtures for 24 weeks. The study was conducted to determine the effect of sesame hulls which are known to contain a high proportion of oxalic acid and phytic acid, which are toxic substances causing various physical disorders. The rats were divided into four groups, a control group which was fed on a standard diet and three groups fed with 20%, 10% and 5% mixtures of sesame seed hulls respectively. The study was designed to observe the same effect, but in this case the rats were divided into two groups, one fed with a 5% mixture of whole sesame seeds and the other with a 5% mixture of dehulled seeds. The results are as follows: 1) An examination of weight gains showed that group I and II which were fed on 20% and 10% mixture of sesame hulls were significantly retarded in comparison with the control group(P<0. 05). 2) Comparisons of organ weights, group I (20% mixture) showed relatively lower weights(P<0.05). 3) The cholesterol content of the blood serum and liver tissue of group I (20% mixture) and group II (10% mixture) were significantly higher than that of the control. 4) The group fed on the whole sesame seed diet and that fed on the dehulled seed diet differed significantly from each other. 5) With the results stated above, the investigators could observe that a high content of sesame hulls in the diet caused retardation in growth and might be the cause of many physical disorders. Though these effects are not important in Korea at present, the increasing intake of sesame seeds and oils indicates that it may become an important problems.

• Proceedings of the KWS Conference
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• 2000.04a
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• pp.219-221
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• 2000