• Korean Journal of Fisheries and Aquatic Sciences
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• v.46 no.6
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• pp.746-752
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• 2013

An 8-week feeding experiment was conducted to evaluate three types of squid Sepia esculenta liver powder (SLP) as a dietary protein source for replacement of fish meal (FM) in the juvenile black rockfish, Sebastes schlegeli. For replacement of FM, six experimental diets were formulated with 5 or 10% of either of three types (A, B, C) of SLP: SLP-$A_5$, SLP-$A_{10}$, SLP-$B_5$, SLP-$B_{10}$, SLP-$C_5$, and SLP-$C_{10}$. One of the control diets contained 100% FM as the protein source, and the other was a commercial diet (Com). Fish with an average body weight of $6.50{\pm}0.03g$ ($mean{\pm}SD$) were allocated randomly in triplicate groups of 50 to aquaria and fed the experimental diets until satiation. The weight gain (WG) and specific growth rate (SGR) of fish fed the FM, SLP-$A_5$, SLP-$A_{10}$, and SLP-$B_5$ diets were higher than those of fish fed the Com, SLP-$B_{10}$, SLP-$C_5$ and SLP-$C_{10}$ diets. No significant differences were observed in WG and SGR among the diet groups, with the exception of the SLP-$C_{10}$ diet group. The feed efficiency (FE) and protein efficiency ratio (PER) of fish fed the SLP-$A_5$, SLP-$A_{10}$, and SLP-$B_5$ diets did not differ from those fed the control diet. However, fish fed SLP-$B_{10}$ and SLP-$C_{10}$ had lower FE and PER than the fish fed the FM, commercial, SLP-$A_5$, SLP-$A_{10}$, and SLP-$B_5$ diets. Both the SLP-A and SLP-B diets, but not the SLP-C diets, replaced up to 10% and 5% of FM for juvenile black rockfish, respectively. The results of this experiment provide information that will assist in formulating an inexpensive and practical diet containing SLP for juvenile black rockfish.

• Journal of the Mineralogical Society of Korea
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• v.17 no.1
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• pp.75-83
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• 2004

Blackening on stone monuments is serious problem, because it is not only aesthetically unattractive, but also an important process in stone deterioration. Black surface layers contain often a large amounts of iron compound. Therefore it is assumed that besides another elements the iron have influence on blackening of surface. After the samples of black surface layers were collected from the stone monuments (Museumsinsel) in Berlin, Germany, especially in this study has been used Mossbauer spectroscopy in order to determine the valence and chemical composition of iron. Mineralogical and chemical analyses were carried out X-ray diffractormetry and X-ray fluorescence method on the black surface layer's samples and original stone samples. The origin of Iron compound in the black surface provides the important clue for the conservation work of stone monuments, like removing of black surface. To find it, black surface layer on white sandstone -it contains very small amount of iron compound- was compared with that on the red sandstone (Fe contains very small amount of iron compound- was compared with that on the red sandstone (Fe abundant). As a results, it is assumed that the iron in black layer on white sandstone is originated mainly from a surrounding environmental material and for the iron in black layer on the red sandstone is responsible the original stone. Even if black surface layer was removed from the red sandstone, some other conservation method should be studied beyond removing of black surface layer, because the iron can move continuously from the inner zone of original stone to surface area.

• Korean Journal of Materials Research
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• v.11 no.8
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• pp.685-689
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• 2001

We carried out these experiments to examine the effects of element substitution of Co and La-Co for Sr-ferrite. The calcined properties of Co and La-Co element substitution were examined, and also the sintered magnetic properties were measured with the stoichiometric condition. The magnetic properties of $(La-Co)_{0.3}-SrM$ composition are as follows; $(M_s)$: 71.08 emu/g, $iH_c$: 4.38 kOe and $B_r$ : 4.18 kG, $iH_ c$ :4.35 kOe, $BH_{max}$: 4.3 MGOe. The $BH_{max}$ value was increased up to 10 % compared with conventional values. Our results imply that the magnetic properties of Sr-ferrite can be improved by the substitution of those elements.

• Korean Chemical Engineering Research
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• v.56 no.3
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• pp.297-302
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• 2018

Bead type and hollow fiber type catalyst (HFC, Hollow Fiber type Catalyst) was prepared by $La_{0.1}Sr_{0.9}Co_{0.2}Fe_{0.8}O_{3-{\delta}}$ (LSCF1928) perovskite powder catalyst which showed excellent methane complete oxidation characteristics through previous studies. The HFC have a cylindrical shape with an empty interior, and pores can be formed through Phase inversion method so the specific surface area can be remarkably improved. In the case of the bead type catalyst prepared by adding Methyl Cellulose (MC), $SrCO_3$ was produced in addition to the original catalyst composition of LSCF1928 due to the reaction of $CO_2$ emitted from MC and Sr of the catalyst. In the case of the HFC, a single phase perovskite structure was obtained without impurities. The HFC calcined at $700{\sim}900^{\circ}C$ showed pore structure of finger-sponge-finger structure, and 99.9% oxygen conversion rate was achieved through complete oxidation of methane at $475^{\circ}C$. Air gap and spinning pressure condition were changed to control the HFC pore. 2 cm air gap and 7 bar spinning pressure showed the best catalytic performance and achieved oxygen conversion rates of more than 70.65%, 93.01%, and 99.99% at $425^{\circ}C$, $450^{\circ}C$ and $475^{\circ}C$, respectively.

• Journal of Energy Engineering
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• v.7 no.1
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• pp.146-156
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• 1998

Fly ash produced in coal combustion is a fine-grained material consisting mostly of spherical, glassy, and porous particles. A physical, morphological, and chemical characteristic of fly ash has been analyzed. This study may contribute to the data base of domestic fly ash, the improvement of combustion efficiency, ash recycling and ash collection in the electrostatic precipitator. The physical property of fly ash is determined using a particle counter for the measurement of ash size distribution and gravimeter. Morphological characteristic of fly ash is performed using a scanning electron micrograph and an optical microscope. The chemical components of fly ash are determined using an inductively coupled plasma emission spectrometry (ICP). The distribution of fly ash size was ranged from 15 to 25 $\mu$m in mass median diameter. Exposure conditions of flue gas temperature and duration within the combustion zone of the boiler played an important role on the morphological properties of the fly ash such as shape, relative opacity, coloration, cenosphere and plerosphere. The spherical fly ash might be generated at the condition of complete combustion. The size of fly ash was found to be increased the with particle-particle interaction of agglomeration and coagulation. Fly ash consisted of $SiO_2\;Al_2O_3\;and\;Fe_2O_3$ with 85% and carbon with 3~10% of total mass.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.21 no.1
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• pp.41-46
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• 2011

The artificial aggregates (AAs) composing of 2 wastes, coal bottom ash and dredged soil (7 : 3, weight ratio) were fabricated as a function of red mud contents,0~30 wt% using direct sintering method at $1050{\sim}1250^{\circ}C$ for 10 min, and those physical properties were evaluated. Especially, in order to analyze the red mud addition effect on the bloating phenomenon of AAs manufactured, the specific gravity and water absorption were measured and studied linked with the microstructural observation results. The lightening of AAs was enhanced due to increased bloating with increasing temperature and red mud contents. The AAS sintered at $1050{\sim}1150^{\circ}C$ showed well-developed black-coring structure, but for the specimens containing red mud sintered over $1200^{\circ}C$ generated excessive liquid and gas caused by reduction of $Fe_2O_3$, thus the black-coring part was gradually burst open out of shell of AAs. Particularly, all specimens containing 30 wt% red mud was burst up when sintered over $1100^{\circ}C$. The AAs containing no red mud sintered at $1200^{\circ}C$ had a specific gravity of about 1.2 and those containing 20 wt% had below 1.0 which are characters of lightweight aggregate.

• Journal of Bio-Environment Control
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• v.10 no.4
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• pp.251-257
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• 2001

This experiment was conducted to investigate the effect of chitosan on the growth and yield of fall-planted potatoes. The research was carried out in fall-planted potatoes from August 2000 to Aprial 2001 at the height of 250m above sea level in Jeju Island. Soaking for 30 min. of seed potatoes in 200 times diluted solution of 3% liquid chitosan shortened days to emergence by 4 to 6 days. Stem length, number of stems and number of stolons per plant were 56.5 cm, 4.3, and 19.0, respectively, when seed potatoes were soaked for 30 min. in 200 times diluted solution of 3% liquid chitossan. Total potato yield in this treatment reached 2,963 kg per 10a and was significantly greater than in other treatments. Yield of marketable tubers (greater than 30g) per 10a for treatment of seed potatoes soaking in 200 times diluted solution of 3% liquid chitosan and for treatment of foliage spray with 200 times diluted solution of 3% liquid chitosan plus chitosna power (10 kg per 10a) miximg with soil was 2,761 kg and 2,628 kg, respectively. Contents of Mg, Fe and B were the greatest in the treatment of 30 min. soaking of seed potatoes in 200 times diluted solution of 3% liquid chitosanm. The increased contents of these elements are considered to have caused yield increase as a result of increased chlorophyll content for photosynthesis.

• Proceedings of the Korean Institute of Resources Recycling Conference
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• 2004.12a
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• pp.27-34
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• 2004

This experiment was carried out to examine the effects of morphology on properties of La-Co substituted SrM ferrite. The magnetic properties of calcined and sintered materials varied with the substitutional amount of La and Co elements in Sr-ferrite. In the substituted SrM ferrite, the atomic fraction x of La is directly related to the mole ratio n of iron oxide and the atomic fraction y of Co by equation x=2ny. The HcJ values of the calcined powder were about 270 kA/m and 240 kA/m with x=0.3 and K=0.2, respectively at stoichiometriy, n=6.0. Crystallites of the sintered material were grown with a plate shape, and their size decreased with increasing mole ratios. Such a shape was caused by the initial state of crystallite formed after calcination. In case of x=0.3 and n=6.0, Br was 415 mT and HcJ was 355 kA/m, and in x=0.2 and n=6.0, Br was 410 mT and HcJ was 370kA/m. The squareness in 2nd quarter of BH curve with x=0.2 was smoothly improved compared with x=0.3

• Analytical Science and Technology
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• v.15 no.4
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• pp.365-372
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• 2002

In this study, inorganic elemental distribution in Korean adult human tissue of liver, lung, muscle, kidney, rib and thyroid has been investigated. These tissues were collected from human's body within 48 hours after their death according to IAEA's recommended method, dried by freeze drying method and then pulverized. Neutron activation analysis was applied to these samples to determine the concentrations of 5 major elements of Ca, Mg, Na, K, and Cl and 12 trace elements of Mn, I, Sr, As, Br, Co, Cr, Cs, Fe, Rb, Se, and Zn. To confirm accuracy of analytical result was performed using three kinds of standard reference materials and resulted that the relative error is within 10% for the most of elements and the Z-score indicating a performance of analysis is within 2. The elemental distribution shows that the major elements are distributed homogeneously with a specific concentration and that the trace elements shows a distribution of different concentration with kinds of tissue and their age. Particularly, iodine shows higher concentration with 1000 ${\mu}g/g$ in thyroid, and calcium and strontium show the concentration with 15.9% and 84.4 ${\mu}g/g$ in rib, respectively.

• Applied Chemistry for Engineering
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• v.21 no.5
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• pp.590-592
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• 2010

Li-Mn spinel ($LiMn_2O_4$) is prepared by a hydrothermal process with K-Birnessite ($KMnO_4{\cdot}yH_2O$) as a precursor. The K-Birnessite obtained via a hydrothermal process with potassium permanganate [$KMnO_4$] and urea [$CO(NH_2)_2$] as starting materials are converted to Li-Mn spinel nanoparticles reacting with LiOH. The molar ratio of LiOH/K-Birnessite is adjusted in order to find the effect of the ratio on the structural, morphological and electrochemical performances of the Li-Mn spinel. X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDS), and thermogravimetry (TG) are used to investigate the crystal structure and morphology of the samples. Galvanostatic charge and discharge are carried out to measure the capacity and rate capability of the Li-Mn spinel. The capacity shows a maximum value of $117\;mAhg^{-1}$ when the molar ratio of LiOH/K-Birnessite is 0.8 and decreases with the increase of the ratio. However the rate capability is improved with the increase of the ratio due to the reduction of the particle size.