• Korean Journal of Soil Science and Fertilizer
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• v.11 no.2
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• pp.81-87
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• 1979

In order to observe the lasting effect of NK-compound mineral fertilizer and organic compound fertilizer including Myweon organic liquid fertilizer, a pot experiment was conducted with rice (Oriza Sativa) variety: Nong Back. These fertilizers were applied as basal and the same amount of urea form of nitrogen was top dressed about a month after transplanting, July seventh, 1977. Results obtained are as follows; 1. The lasting effect of various fertilizers were laid in following decreasing order; Myweon liquid < Organic compound fertilizer (Myweon coop. made) > NK-compound fertilizer (Chosun coop. made) Single fertilizer. It was considered that organic matter served as microbial feed and lead a temporary fixation of available plant nutrients in the soil, and the reduced surface area of the compound fertilizers slowed down the availability of the fertilizers. 2. The fertilizer showing greater lasting effect produced more panicles per hill and less grains per panicle than the fertilizers showing less lasting effect, and brought low maturity, which resulted in low paddy yield the paddy producing efficiency of nitrogen absorbed by straw was also low in the former fertilizers. Such advanced effect of the former fertilizer was considered to be related with the variety of early maturity and unseasonable topdressing of fertilizer which made at the maximum tillering stage. 3. For the production of Japonica type paddy with heavy fertilization which may required to depress the early growth a little and promote the late growth, it might be necessary to develop slow releasing fertilizers such as single fertilizer formulated to a large grains or compound fertilizer containing organic matter. 4. If the nitrogen content of paddy, Nong Back, far excess 0.64 or 0.65% and reaches 0.68% or above, the yield of the variety seemed to be decreased remarkbly through the low maturity rate and thousand grain weight.

• Journal of the Korean Society for Heat Treatment
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• v.23 no.3
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• pp.150-155
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• 2010

Generally, plasma nitriding process has composed with a nitriding layer within glow discharge region occurred by energy exchange. The dissociations of nitrogen molecules are very difficult to make neutral atoms or ionic nitrogen species via glow discharge area. However, the captured electrons in which a double-folded screen with same potential cathode can stimulate and come out some single atoms or activated ionic species. It was showed an important thing that is called "hat is a dominant component in this nitriding process?" in plasma nitriding process and it can take an effective species for without compound layer. During a plasma nitriding process, it was able to estimate with analyzing and identification by optical emission spectroscopy (OES) study. And then we can make comparative studies on the nitrogen transfer with plasma nitriding and ATONA process using plasma diagnosis and metallurgical observation. From these observations, we can understand role of active species of nitrogen, like N, $N^+$, ${N_2}^+$, ${N_2}^*$ and $NH_x$-radical, in bulk plasma of each process. And the same time, during DC plasma nitriding and other processes, the species of FeN atom or any ionic nitride species were not detected by OES analyzing.

• Journal of Ginseng Research
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• v.21 no.3
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• pp.214-218
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• 1997

New simple methods for the Isolation of sesquiterpenes from Panax ginseng were developed. First, volatile compounds were isolated by simultaneous distillation and extraction (SDE) with 30% methanol and $\alpha$-hexane instead of water and ethyl ether/pentane (1:1). Secondly, head space volatiles in U-shaped tube at 7$0^{\circ}C$ were passed through C18 Sep-Pak by nitrogen gas streaming and the adsorbed volatiles were fluted by $\alpha$-hexane. TLC analysis showed that the volatile concentrates consisted mainly of terpenes when colored by vanillin-sulfuric and. GC/MS data revealed that approximately 30 sesquiterpenes of molecular weight 204 occupied 81.1% or more of the volatile concentrates isolated by those two newly developed methods. Among these, alloaromadendrene, germacrene B, isocaryophyllene, $\alpha$-neoclovene, ${\gamma}$-muurolene, $\beta$-panaslnsene, and $\alpha$-humulene were identified as being major sesqulterpenes by authentic samples or literatme search Key words : Panax ginseng, volatile compound, sesquiterpene, isolation, new method, GC/MS.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.223-223
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• 2007

Thermal and mechanical properties were investigated in several semi-conductive materials which is composed of carbon black and polymer. EVA, EEA, and EBA is normally used for matrix polymer and normally acetylene black and furnace black is used. Isothermal thermo gravimetric analysis is done as a function of atmosphere and temperature. In nitrogen atmosphere semicon compound was slowly degradaded but in ambient condition degradaded fast. So in the cable manufacturing, atmosphere and materials are very important.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2009.04a
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• pp.165-171
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• 2009

A compound agent that mixes inert gas agents and halocarbon agents and a complex fire suppression system using the compound agent have been developed. The ultimate goal of this study is to develop the extinguishing agent which doesn't destroy the ozone layer and has low GWP and to develop the fire suppression system. As a result of the test and research for inert gas agents and halocarbon agents, nitrogen and FK-5-1-12 were selected finally and have been tested and studies for three years. Thus, the optimal extinguishing agent and fire suppression system have been accomplished. The performance of the agent and system was tested according to KFI performance test technical standards for gas fire extinguishing system and the fitness of the agent and system for a fire was certified by Korea Fire Industry Technology Institute (KFI).

• Journal of the Korean Society for Heat Treatment
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• v.14 no.1
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• pp.8-16
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• 2001

The effects of gas composition, pressure, temperature and time on the case thickness, hardness and nitride formation in the surface of tool steels(STD11 and STD61) have been studied by micro-pulse plasma nitriding. External compound layer and internal diffusion layer and the diffusion layer were observed in the nitrided case of tool steels. The relative amounts and kind of phases formed in the nitrided case changed with the change of nitriding conditions. Generally, only nitride phases such as ${\gamma}(Fe_4N)$, ${\varepsilon}(Fe_{2-3}N)$, or $Cr_{1.75}V_{0.25}N_2$ phases were detected in the compound layer, while nitride and carbide phases such as ${\varepsilon}-nitride(Fe_{2-3}N)$, $(Cr,Fe)_{\gamma}C_3$ or $Fe_3C$ were detected in the diffusion layer by XRD analysis. The thickness of compound layer increased with the increase of nitrogen content in the gas composition. Maximum case depth was obtained at gas pressure of 200Pa.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.10
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• pp.4047-4054
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• 2010

We studied the release characteristics of the marine sediment which could facilitate sea eutrophication through some lab-scale simulation experiments. Environmental indicators such as pH, ORP(oxidation reduction potential), nitrogens, and phosphates were measured in order to calculate the corresponding release rates. $CaO_2$, an oxygen releasing compound was used to determine how it would effect on the natural process of sedimental release. COD, ammonia nitrogen, phosphorous compounds were less released under the oxic environment caused by $CaO_2$. This basic data will help developing methodology for reducing marine eutrophication which may be initiated by the sedimental release.

• Journal of the Korean Society for Heat Treatment
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• v.9 no.2
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• pp.130-138
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• 1996

It has been investigated that the ion nitriding effects of a STD61 steel in various time conditions of 3 to 9 hours, and the microstructure of compound and diffusion layers of the ion nitrided specimen for 6 hours and subsequently reheated for 1 hour at various temperatures of $400{\sim}800^{\circ}C$ As the nitriding time increased, the thickness of compound and diffusion layers was increased, but the hardness of surface was not considerably increased (Max Hv=1045 at 9hrs). Some of the nitrogen was denitrided out of the surfac and diffused into the core, and also the oxides ($Fe_3O_4$, $Fe_2O_3$) were formed on the surface of the specimen during reheating. The compound layer was partially decomposed at about $600^{\circ}C$ but the diffusion layer was increased up to $800^{\circ}C$. With increasing reheated temperture, the hardness of the surface was decreased, whereas the hardness depth of diffusion layer (0.25mm) was increased up to $600^{\circ}C$ more than that of ion nitrided (0.18mm). The blend-heat treated STD61 steel by ion nitriding is therefore expected to hold on the characteristics of ion nitriding up to $600^{\circ}C$.

• Bulletin of the Korean Chemical Society
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• v.23 no.7
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• pp.948-952
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• 2002

Three-dimensional terbium coordination polymers with the formulas of [Tb4(NDC)6(H2O)5]${\cdot}$2H2O (1) and [Tb2(BPDC)3(H2O)3]${\cdot}$H2O (2) (NDC = 2,6-naphthalenedicarboxylate; BPDC = 2,2'-bipyridine-4,4'-dicarboxy-late) were prepared by hydrothermal reactions. Both compounds were structurally characterized by X-ray diffraction. Compound 1 has a polymeric structure that contains four distinct Tb metals. Three Tb metals have a square-antiprismatic structure, and the remaining one has a 9-coordinate, triply capped trigonal-prismatic structure. Compound 2 is also a polymer with two distinct Tb metals, both of which have a square-antiprismatic structure. The pyridine nitrogen atoms of the BPDC 2- ligand do not coordinate to the metal centers in compound 2.

• Journal of the Korean institute of surface engineering
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• v.29 no.5
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• pp.443-448
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• 1996

In order to plasma-sulfnitride by combining ion-nitriding of a steel and sputtering of MoS$_2$, chromium-molybdenum steel was plasma-sulfritrided using hollow cathode discharge with parallel electrodes which are a main of the steel and a subsidiary cathode of $MoS_2$. The treatment was carried out at 823K for 10.8ks under 665Pa in a 30% $N_2$-70% $H_2$ gas atmosphere. Plasma-sulfnitriding layers formed of the steel were characterized with EDX, XRD, micrographic structure observation and hardness measurement. A compound layer of 8-15$\mu\textrm{m}$ and nitrogen diffusion layer of about 400$\mu\textrm{m}$ were formed on the surface of plasma-sulfnitrided steel. The compound layer consisted of FeS containing Mo and iron nitrides. The nitrides of $\varepsilon$-$Fe_2_3N$ and $\gamma$'-$Fe_4N$ formed under the FeS. The thickness of compound layer and surface hardness were different with the gaps between main and subsidiary cathodes even in the same sulfnitriding temperature. The surface hardnesses after plasma-sulfnitriding were distributed from 640 to 830Hv. The surface hardness was higher in the plasma-sulfnitriding than the usual sulfnitriding in molten salt. This may be due to Mo in sulfnitriding layer.