This study investigated the effect of the hatch spacing parameter on the microstructure and mechanical properties of SA508 Gr.3 steel manufactured by laser powder bed fusion (L-PBF) for a nuclear pressure vessel. Materials were prepared with varying hatch spacing (0.04 mm [H4] and 0.06 mm [H6]). The H4 exhibited finer and more uniformly distributed grains, while the H6 showed less porosity and a lower defect fraction. The yield strength of the H4 material was higher than that of the H6 material, but there was a smaller difference between the materials in tensile strength. The measured elongation was 5.65% for the H4 material and 10.41% for the H6 material, showing a significantly higher value for H6. An explanation for this is that although the H4 material had a microstructure of small and uniform grains, it contained larger and more numerous pore defects than the H6 material, facilitating stress concentration and the initiation of microcracks.

Gray leaf spot caused by Stemphylium spp., is a major disease of tomatoes, and it threatens its cultivation worldwide, especially in warm and humid areas. This study was conducted on 223 tomato germplasm conserved at the National Agrobiodiversity Center to select the resources resistant to the gray leaf spot pathogen strain previously isolated in Korea, using a bioassay and genotypic analysis of the resistance gene (Sm). Two weeks after inoculation with Stemphylium lycopersici, the disease index (rated on a scale of 0-4) of gray leaf spot was assessed in detached tomato leaves. The results showed that 22 resources were resistant, with a disease index of 0-1. Additionally, 65 genetic resources were found to be moderately resistant, with a disease index between 1.0 and 2.0. Subsequently, Hybridization Probe Melting (HPM) analysis of the 22 resistant genetic resources confirmed the genotype of the gray leaf spot resistance gene (Sm). Among them, 20 genetic resources showed a homozygous resistant genotype. The resources selected in this research may contribute to the breeding of new tomato varieties resistant to gray leaf spot and may serve as a basis for further genotypic analysis studies.

The Ag/WC electrical contacts were prepared via powder metallurgy using 60 wt% Ag, 40 wt% WC, and small amounts of Co3O4 with varying WC particle sizes. After the fabrication of the contact materials, microstructure observations confirmed that WC-1 had an average grain size (AGS) of 0.27 μm, and WC-2 had an AGS of 0.35 μm. The Ag matrix in WC-1 formed fine grains, whereas a significantly larger and continuous growth of the Ag matrix was observed in WC-2. This indicates the different flow behaviors of liquid Ag during the sintering process owing to the different WC sizes. The electrical conductivities of WC-1 and WC-2 were 47.8% and 60.4%, respectively, and had a significant influence on the Ag matrix. In particular, WC-2 exhibited extremely high electrical conductivity owing to its large and continuous Ag-grain matrix. The yield strengths of WC-1 and WC-2 after compression tests were 349.9 MPa and 280.7 MPa, respectively. The high yield strength of WC-1 can be attributed to the Hall–Petch effect, whereas the low yield strength of WC-2 can be explained by the high fraction of high-angle boundaries (HAB) between the WC grains. Furthermore, the relationships between the microstructure, electrical/mechanical properties, and deformation mechanisms were evaluated.

The Ti-6Al-4V lattice structure is widely used in the aerospace industry owing to its high specific strength, specific stiffness, and energy absorption. The quality, performance, and surface roughness of the additively manufactured parts are significantly dependent on various process parameters. Therefore, it is important to study process parameter optimization for relative density and surface roughness control. Here, the part density and surface roughness are examined according to the hatching space, laser power, and scan rotation during laser-powder bed fusion (LPBF), and the optimal process parameters for LPBF are investigated. It has high density and low surface roughness in the specific process parameter ranges of hatching space (0.06–0.12 mm), laser power (225–325 W), and scan rotation (15°). In addition, to investigate the compressive behavior of the lattice structure, a finite element analysis is performed based on the homogenization method. Finite element analysis using the homogenization method indicates that the number of elements decreases from 437,710 to 27 and the analysis time decreases from 3,360 to 9 s. In addition, to verify the reliability of this method, stress–strain data from the compression test and analysis are compared.

The global demand for raw lithium materials is rapidly increasing, accompanied by the demand for lithiumion batteries for next-generation mobility. The batch-type method, which selectively separates and concentrates lithium from seawater rich in reserves, could be an alternative to mining, which is limited owing to low extraction rates. Therefore, research on selectively separating and concentrating lithium using an electrodialysis technique, which is reported to have a recovery rate 100 times faster than the conventional methods, is actively being conducted. In this study, a lithium ion selective membrane is prepared using lithium lanthanum titanate, an oxide-based solid electrolyte material, to extract lithium from seawater, and a large-area membrane manufacturing process is conducted to extract a large amount of lithium per unit time. Through the developed manufacturing process, a large-area membrane with a diameter of approximately 20 mm and relative density of 96% or more is manufactured. The lithium extraction behavior from seawater is predicted by measuring the ionic conductivity of the membrane through electrochemical analysis.

Recently, considerable attention has been given to nickel-based superalloys used in additive manufacturing. However, additive manufacturing is limited by a slow build rate in obtaining optimal densities. In this study, optimal volumetric energy density (VED) was calculated using optimal process parameters of IN718 provided by additive manufacturing of laser powder-bed fusion. The laser power and scan speed were controlled using the same ratio to maintain the optimal VED and achieve a fast build rate. Cube samples were manufactured using seven process parameters, including an optimal process parameter. Analysis was conducted based on changes in density and melt-pool morphology. At a low laser power and scan speed, the energy applied to the powder bed was proportional to and not . At a high laser power and scan speed, a curved track was formed due to Plateau-Rayleigh instability. However, a wide melt-pool shape and continuous track were formed, which did not significantly affect the density. We were able to verify the validity of the VED formula and succeeded in achieving a 75% higher build rate than that of the optimal parameter, with a slight decrease in density and hardness.

AlSi10Mg alloys are being actively studied through additive manufacturing for application in the automobile and aerospace industries because of their excellent mechanical properties. To obtain a consistently high quality product through additive manufacturing, studying the flowability and spreadability of the metal powder is necessary. AlSi10Mg powder easily forms an oxide film on the powder surface and has hydrophilic properties, making it vulnerable to moisture. Therefore, in this study, AlSi10Mg powder was hydrophobically modified through silane surface treatment to improve the flowability and spreadability by reducing the effects of moisture. The improved flowability according to the number of silane surface treatments was confirmed using a Carney flowmeter. In addition, to confirm the effects of improved spreadability, the powder prior to surface treatment and that subjected to surface treatment four times were measured and compared using s self-designed recoating tester. The results of this study confirmed the improved flowability and spreadability based on the modified metal powder from hydrophilic to hydrophobic for obtaining a highquality additive manufacturing product.

A Cu-15Ag-5P filler metal (BCuP-5) is fabricated on a Ag substrate using a high-velocity oxygen fuel (HVOF) thermal spray process, followed by post-heat treatment (300oC for 1 h and 400oC for 1 h) of the HVOF coating layers to control its microstructure and mechanical properties. Additionally, the microstructure and mechanical properties are evaluated according to the post-heat treatment conditions. The porosity of the heat-treated coating layers are significantly reduced to less than half those of the as-sprayed coating layer, and the pore shape changes to a spherical shape. The constituent phases of the coating layers are Cu, Ag, and Cu-Ag-Cu3P eutectic, which is identical to the initial powder feedstock. A more uniform microstructure is obtained as the heat-treatment temperature increases. The hardness of the coating layer is 154.6 Hv (as-sprayed), 161.2 Hv (300oC for 1 h), and 167.0 Hv (400oC for 1 h), which increases with increasing heat-treatment temperature, and is 2.35 times higher than that of the conventional cast alloy. As a result of the pull-out test, loss or separation of the coating layer rarely occurs in the heat-treated coating layer.

In this study, a new manufacturing process for a multilayer-clad electrical contact material is suggested. A thin and dense BCuP-5 (Cu-15Ag-5P filler metal) coating layer is fabricated on a Ag plate using a high-velocity oxygen-fuel (HVOF) process. Subsequently, the microstructure and bonding properties of the HVOF BCuP-5 coating layer are evaluated. The thickness of the HVOF BCuP-5 coating layer is determined as 34.8 μm, and the surface fluctuation is measured as approximately 3.2 μm. The microstructure of the coating layer is composed of Cu, Ag, and Cu-Ag-Cu3P ternary eutectic phases, similar to the initial BCuP-5 powder feedstock. The average hardness of the coating layer is 154.6 HV, which is confirmed to be higher than that of the conventional BCuP-5 alloy. The pull-off strength of the Ag/BCup-5 layer is determined as 21.6 MPa. Thus, the possibility of manufacturing a multilayer-clad electrical contact material using the HVOF process is also discussed.

This study investigates the effect of process stopping and restarting on the microstructure and local nanoindentation properties of 316L stainless steel manufactured via selective laser melting (SLM). We find that stopping the SLM process midway, exposing the substrate to air having an oxygen concentration of 22% or more for 12 h, and subsequently restarting the process, makes little difference to the density of the restarted area (~ 99.8%) as compared to the previously melted area of the substrate below. While the microstructure and pore distribution near the stop/restart area changes, this modified process does not induce the development of unusual features, such as an inhomogeneous microstructure or irregular pore distribution in the substrate. An analysis of the stiffness and hardness values of the nano-indented steel also reveals very little change at the joint of the stop/restart area. Further, we discuss the possible and effective follow-up actions of stopping and subsequently restarting the SLM process.

Ti-6Al-4V alloy has a wide range of applications, ranging from turbine blades that require smooth surfaces for aerodynamic purposes to biomedical implants, where a certain surface roughness promotes biomedical compatibility. Therefore, it would be advantageous if the high volumetric density is maintained while controlling the surface roughness during the LPBF of Ti-6Al-4V. In this study, the volumetric energy density is varied by independently changing the laser power and scan speed to document the changes in the relative sample density and surface roughness. The results where the energy density is similar but the process parameters are different are compared. For comparable energy density but higher laser power and scan speed, the relative density remained similar at approximately 99%. However, the surface roughness varies, and the maximum increase rate is approximately 172%. To investigate the cause of the increased surface roughness, a nonlinear finite element heat transfer analysis is performed to compare the maximum temperature, cooling rate, and lifetime of the melt pool with different process parameters.

Oxide dispersion-strengthened (ODS) steel has excellent high-temperature properties, corrosion resistance, and oxidation resistance, and is expected to be applicable in various fields. Recently, various studies on mechanical alloying (MA) have been conducted for the dispersion of oxide particles in ODS steel with a high number density. In this study, ODS steel is manufactured by introducing a complex milling process in which planetary ball milling, cryogenic ball milling, and drum ball milling are sequentially performed, and the microstructure and high-temperature mechanical properties of the ODS steel are investigated. The microstructure observation revealed that the structure is stretched in the extrusion direction, even after the heat treatment. In addition, transmission electron microscopy (TEM) analysis confirmed the presence of oxide particles in the range of 5 to 10 nm. As a result of the room-temperature and high-temperature compression tests, the yield strengths were measured as 1430, 1388, 418, and 163 MPa at 25, 500, 700, and 900oC, respectively. Based on these results, the correlation between the microstructure and mechanical properties of ODS steel manufactured using the composite milling process is also discussed.

The effects of different spray angles (90°, 85°, 80°) on the microstructure and mechanical properties of a Y2O3 coating layer prepared using the atmospheric plasma spray (APS) process were studied. The powders employed in this study had a spherical shape and included a cubic Y2O3 phase. The APS coating layer exhibited the same phase as the powders. Thickness values of the coating layers were 90°: 203.7 ± 8.5 μm, 85°: 196.4 ± 9.6 μm, and 80°: 208.8 ± 10.2 μm, and it was confirmed that the effect of the spray angle on the thickness was insignificant. The porosities were measured as 90°: 3.9 ± 0.85%, 85°: 11.4 ± 2.3%, and 80°: 12.7 ± 0.5%, and the surface roughness values were 90°: 5.9 ± 0.3 μm, 85°: 8.5 ± 1.1 μm, and 80°: 8.5 ± 0.4 μm. As the spray angle decreased, the porosity increased, but the surface roughness did not show a significant difference. Vickers hardness measurements revealed values of 90°: 369.2 ± 22.3, 85°: 315.8 ± 31.4, and 80°: 267.1 ± 45.1 HV. It was found that under the condition of a 90° angle with the lowest porosity exhibited the best hardness value. Based on the aforementioned results, an improved method for the APS Y2O3 coating layer was also discussed.

In this study, an AISI 316 L alloy was manufactured using a selective laser melting (SLM) process. The tensile and impact toughness properties of the SLM AISI 316 L alloy were examined. In addition, stress relieving heat treatment (650oC / 2 h) was performed on the as-built SLM alloy to investigate the effects of heat treatment on the mechanical properties. In the as-built SLM AISI 316 L alloy, cellular dendrite and molten pool structures were observed. Although the molten pool did not disappear following heat treatment, EBSD KAM analytical results confirmed that the fractions of the low- and high-angle boundaries decreased and increased, respectively. As the heat treatment was performed, the yield strength decreased, but the tensile strength and elongation increased only slightly. Impact toughness results revealed that the impact energy increased by 33.5% when heat treatment was applied. The deformation behavior of the SLM AISI 316 L alloy was also examined in relation to the microstructure through analyses of the tensile and impact fracture surfaces.

Ni–Cr–Al metal-foam-supported catalysts for steam methane reforming (SMR) are manufactured by applying a catalytic Ni/Al2O3 sol–gel coating to powder alloyed metallic foam. The structure, microstructure, mechanical stability, and hydrogen yield efficiency of the obtained catalysts are evaluated. The structural and microstructural characteristics show that the catalyst is well coated on the open-pore Ni–Cr–Al foam without cracks or spallation. The measured compressive yield strengths are 2–3 MPa at room temperature and 1.5–2.2 MPa at 750oC regardless of sample size. The specimens exhibit a weight loss of up to 9–10% at elevated temperature owing to the spallation of the Ni/Al2O3 catalyst. However, the metal-foam-supported catalyst appears to have higher mechanical stability than ceramic pellet catalysts. In SMR simulations tests, a methane conversion ratio of up to 96% is obtained with a high hydrogen yield efficiency of 82%.

In this study, the high-temperature oxidation properties of austenitic 316L stainless steel manufactured by laser powder bed fusion (LPBF) is investigated and compared with conventional 316L manufactured by hot rolling (HR). The initial microstructure of LPBF-SS316L exhibits a molten pool ~100 μm in size and grains grown along the building direction. Isotropic grains (~35 μm) are detected in the HR-SS316L. In high-temperature oxidation tests performed at 700oC and 900oC, LPBF-SS316L demonstrates slightly superior high-temperature oxidation resistance compared to HR-SS316L. After the initial oxidation at 700oC, shown as an increase in weight, almost no further oxidation is observed for both materials. At 900oC, the oxidation weight displays a parabolic trend and both materials exhibit similar behavior. However, at 1100oC, LPBF-SS316L oxidizes in a parabolic manner, but HR-SS316L shows a breakaway oxidation behavior. The oxide layers of LPBF-SS316L and HR-SS316L are mainly composed of Cr2O3, Febased oxides, and spinel phases. In LPBF-SS316L, a uniform Cr depletion region is observed, whereas a Cr depletion region appears at the grain boundary in HR-SS316L. It is evident from the results that the microstructure and the hightemperature oxidation characteristics and behavior are related.

In this study, we fabricate a thin- and dense-BCuP-5 coating layer, one of the switching device multilayers, through a plasma spray process. In addition, the microstructure and macroscopic properties of the coating layer, such as hardness and bond strength, are investigated. Both the initial powder feedstock and plasma-sprayed BCuP-5 coating layer show the main Cu phase, Cu-Ag-Cu3P ternary phases, and Ag phase. This means that microstructural degradation does not occur during plasma spraying. The Vickers hardness of the coating layer was measured as 117.0 HV, indicating that the fine distribution of the three phases enables the excellent mechanical properties of the plasma-sprayed BCuP-5 coating layer. The pull-off strength of the plasma-sprayed BCuP-5 coating layer is measured as 16.5 kg/cm2. Based on the above findings, the applicability of plasma spray for the fabrication process of low-cost multi-layered electronic contact materials is discussed and suggested.

A T-800 (Co-Mo-Cr) coating material is fabricated using Co-Mo-Cr powder feedstock and laser cladding. The microstructure and melted Al erosion properties of the laser-cladded T-800 coating material are investigated. The Al erosion properties of the HVOF-sprayed MoB-CoCr and bulk T-800 material are also examined and compared with the laser-cladded T-800 coating material. Co and lave phases (Co2MoCr and Co3Mo2Si) are detected in both the lasercladded T-800 coating and the bulk T-800 materials. However, the sizes of the lave phases are measured as 7.9 μm and 60.6 μm for the laser-cladded and bulk T-800 materials, respectively. After the Al erosion tests, the erosion layer thicknesses of the three materials are measured as 91.50 μm (HVOF MoB-CoCr coating), 204.83 μm (laser cladded T- 800), and 226.33 μm (bulk T-800). In the HVOF MoB-CoCr coating material, coarse cracks and delamination of the coating layer are observed. On the other hand, no cracks or local delamination of the coating layer are detected in the laser T-800 material even after the Al erosion test. Based on the above results, the authors discuss the appropriate material and process that could replace conventional bulk T-800 materials used as molten Al pots.

The Fe-22wt.%Cr-6wt.%Al foams were fabricated via the powder alloying process in this study. The structural characteristics, microstructure, and mechanical properties of Fe-Cr-Al foams with different average pore sizes were investigated. Result of the structural analysis shows that the average pore sizes were measured as 474 μm (450 foam) and 1220 μm (1200 foam). Regardless of the pore size, Fe-Cr-Al foams had a Weaire-Phelan bubble structure, and α-ferrite was the major constituent phase. Tensile and compressive tests were conducted with an initial strain rate of 10−3 /s. Tensile yield strengths were 3.4 MPa (450 foam) and 1.4 MPa (1200 foam). Note that the total elongation of 1200 foam was higher than that of 450 foam. Furthermore, their compressive yield strengths were 2.5 MPa (450 foam) and 1.1 MPa (1200 foam), respectively. Different compressive deformation behaviors according to the pore sizes of the Fe-Cr-Al foams were characterized: strain hardening for the 450 foam and constant flow stress after a slight stress drop for the 1200 foam. The effect of structural characteristics on the mechanical properties was also discussed.

The prediction of Jominy hardness curves and the effect of alloying elements on the hardenability of boron steels (19 different steels) are investigated using multiple regression analysis. To evaluate the hardenability of boron steels, Jominy end quenching tests are performed. Regardless of the alloy type, lath martensite structure is observed at the quenching end, and ferrite and pearlite structures are detected in the core. Some bainite microstructure also appears in areas where hardness is sharply reduced. Through multiple regression analysis method, the average multiplying factor (regression coefficient) for each alloying element is derived. As a result, B is found to be 6308.6, C is 71.5, Si is 59.4, Mn is 25.5, Ti is 13.8, and Cr is 24.5. The valid concentration ranges of the main alloying elements are 19 ppm < B < 28 ppm, 0.17 < C < 0.27 wt%, 0.19 < Si < 0.30 wt%, 0.75 < Mn < 1.15 wt%, 0.15 < Cr < 0.82 wt%, and 3 < N < 7 ppm. It is possible to predict changes of hardenability and hardness curves based on the above method. In the validation results of the multiple regression analysis, it is confirmed that the measured hardness values are within the error range of the predicted curves, regardless of alloy type.

Additively manufactured metallic components contain high surface roughness values, which lead to unsatisfactory high cycle fatigue resistance. In this study, high cycle fatigue properties of selective laser melted Ti-6Al- 4V alloy are investigated and the effect of dry-electropolishing, which does not cause weight loss, on the fatigue resistance is also examined. To reduce the internal defect in the as-built Ti-6Al-4V, first, hot isostatic pressing (HIP) is conducted. Then, to improve the mechanical properties, solution treatment and aging are also implemented. Selective laser melting (SLM)-built Ti64 shows a primary α and secondary α+β lamellar structure. The sizes of secondary α and β are approximately 2 μm and 100 nm, respectively. On the other hand, surface roughness Ra values of before and after dry-electropolishing are 6.21 μm and 3.15 μm, respectively. This means that dry-electropolishing is effective in decreasing the surface roughness of selective laser melted Ti-6Al-4V alloy. The comparison of high cycle fatigue properties between before and after dry-electropolished samples shows that reduced surface roughness improves the fatigue limit from 150 MPa to 170 MPa. Correlations between surface roughness and high cycle fatigue properties are also discussed based on these findings.

In this study, the formation, microstructure, and wear properties of Colmonoy 88 (Ni-17W-15Cr-3B-4Si wt.%) + Stellite 1 (Co-32Cr-17W wt.%) coating layers fabricated by high-velocity oxygen fuel (HVOF) spraying are investigated. Colmonoy 88 and Stellite 1 powders were mixed at a ratio of 1:0 and 5:5 vol.%. HVOF sprayed selffluxing composite coating layers were fabricated using the mixed powder feedstocks. The microstructures and wear properties of the composite coating layers are controlled via a high-frequency heat treatment. The two coating layers are composed of γ-Ni, Ni3B, W2B, and Cr23C6 phases. Co peaks are detected after the addition of Stellite 1 powder. Moreover, the WCrB2 hard phase is detected in all coating layers after the high-frequency heat treatment. Porosities were changed from 0.44% (Colmonoy 88) to 3.89% (Colmonoy 88 + ST#1) as the content of Stellite 1 powder increased. And porosity is denoted as 0.3% or less by inducing high-frequency heat treatment. The wear results confirm that the wear property significantly improves after the high-frequency heat treatment, because of the presence of wellcontrolled defects in the coating layers. The wear surfaces of the coated layers are observed and a wear mechanism for the Ni-based self-fluxing composite coating layers is proposed.

1. 본 연구는 한국 재래종 강낭콩 209자원의 phytochemical 및 항산화활성을 평가하였다. 2. 항산화활성은 DPPH, ABTS, FRAP, SOD를 분석하였으며 phytochemical은 kaempferol, myricetin, quercetin, naringenin 함량을 각각 분석하였다. 3. 항산화활성은 강낭콩 자원 간 다양한 분포를 보였으며 DPPH의 경우 62.3~643.9 (IC50), ABTS의 경우 0.28~1.49 mgAAE/g, FRAP의 경우 0.41~5.44 mgAAE/g, SOD의 경우 50.4 ~ 299.8 (IC50)로 나타났다. 4. Relative antioxidant capacity index (RACI)로 강낭콩 자원의 항산화활성을 비교한 결과 IT104587이 가장 높은 항산화활성을 보였으며 IT189598이 가장 낮은 항산화활성을 보였다. 5. 분석된 Phytochemical 중에서 한국 재래종 강낭콩에서는 Kaempferol이 가장 높은 함량을 나타냈다. 6. PCA 분석 결과 209자원은 3개의 그룹으로 나뉘었으며 이중 그룹 III에 속한 46자원의 강낭콩이 낮은 항산화활성 및 phytochemical 함량을 보였다. 7. 본 연구 결과는 한국 재래종 강낭콩의 항산화활성 및 phytochemical 정보를 제공하며 이 정보는 강낭콩 품종 개발을 위한 기초 정보로 사용될 수 있을 것이다.

This study investigates the microstructure and wear properties of cermet (ceramic + metal) coating materials manufactured using high velocity oxygen fuel (HVOF) process. Three types of HVOF coating layers are formed by depositing WC-12Co, WC-20Cr-7Ni, and Cr3C2-20NiCr (wt.%) powders on S45C steel substrate. The porosities of the coating layers are 1 ± 0.5% for all three specimens. Microstructural analysis confirms the formation of second carbide phases of W2C, Co6W6C, and Cr7C3 owing to decarburizing of WC phases on WC-based coating layers. In the case of WC-12Co coating, which has a high ratio of W2C phase with high brittleness, the interface property between the carbide and the metal binder slightly decreases. In the Cr3C2-20CrNi coating layer, decarburizing almost does not occur, but fine cavities exist between the splats. The wear loss occurs in the descending order of Cr3C2-20NiCr, WC-12Co, and WC-20Cr-7Ni, where WC-20Cr-7Ni achieves the highest wear resistance property. It can be inferred that the ratio of the carbide and the binding properties between carbide–binder and binder–binder in a cermet coating material manufactured with HVOF as the primary factors determine the wear properties of the cermet coating material.

This study investigates the directional recrystallization behavior of Ni based oxide dispersion strengthened (ODS) alloy according to the zone annealing velocity. The zone annealing temperature is set as 1390oC, while the zone velocities are set as 2.5, 4, 6, and 10 cm/h, respectively. The initial microstructure observation of the as-extruded sample shows equiaxed grains of random orientation, with an average grain size of 530 nm. On the other hand, the zone annealed samples show a large deviation in grain size depending on the zone velocities. In particular, grains with a size of several millimeters are observed at 2.5-cm/h zone velocity. It is also found that the preferred orientation varies with the zone annealing velocity. On the basis of these results, this study discusses the role of zone velocities in the directional recrystallization of Ni base ODS alloy.

In order to expand the application of oxide dispersion-strengthened (ODS) steel, a composite material is manufactured by adding mechanically alloyed ODS steel powder to conventional steel and investigated in terms of microstructure and wear properties. For comparison, a commercial automobile part material is also tested. Initial microstructural observations confirm that the composite material with added ODS steel contains i) a pearlitic Fe matrix area and ii) an area with Cr-based carbides and ODS steel particles in the form of a Fe-Fe3C structure. In the commercial material, various hard Co-, Fe-Mo-, and Cr-based particles are present in a pearlitic Fe matrix. Wear testing using the VSR engine simulation wear test confirms that the seatface widths of the composite material with added ODS steel and the commercial material are increased by 24% and 47%, respectively, with wear depths of 0.05 mm and 0.1 mm, respectively. The ODS steel-added composite material shows better wear resistance. Post-wear-testing surface and cross-sectional observations show that particles in the commercial material easily fall off, while the ODS steel-added material has an even, smooth wear surface.

In this study we manufacture a Ni-Cr-B-Si +WC/12Co composite coating layer on a Cu base material using a laser cladding (LC) process, and investigate the microstructural and mechanical properties of the LC coating and Ni electroplating layers (reference material). The initial powder used for the LC coating layer is a powder feedstock with an average particle size of 125 μm. To identify the microstructural and mechanical properties, OM, SEM, XRD, room and high temperature hardness, and wear tests are implemented. Microstructural observation of the initial powder and LC coating layer confirm the layer is composed mainly of γ-Ni phases and WC and Cr23C6 carbides. The measured hardness of the LC coating and Ni electroplating layers are 653 and 154 Hv, respectively. The hardness measurement from room up to high temperatures of 700°C result in a hardness decrease as the temperature increases, but the hardness of the LC coating layer is higher for all temperature conditions. Room temperature wear results show that the wear loss of the LC coating layer is 1/12 of the wear level of the Ni electroplating layer. The measured bond strength is also greater in the LC coating than the Ni electroplating.

This study investigates the oxidation properties of Fe-14Cr ferritic oxide-dispersion-strengthened (ODS) steel at various high temperatures (900, 1000, and 1100°C for 24 h). The initial microstructure shows that no clear structural change occurs even under high-temperature heat treatment, and the average measured grain size is 0.4 and 1.1 μm for the as-fabricated and heat-treated specimens, respectively. Y–Ti–O nanoclusters 10–50 nm in size are observed. High-temperature oxidation results show that the weight increases by 0.27 and 0.29 mg/cm2 for the asfabricated and heat-treated (900°C) specimens, and by 0.47 and 0.50 mg/cm2 for the as-fabricated and heat-treated (1000°C) specimens, respectively. Further, after 24 h oxidation tests, the weight increases by 56.50 and 100.60 mg/cm2 for the as-fabricated and heat-treated (1100°C) specimens, respectively; the latter increase is approximately 100 times higher than that at 1000°C. Observation of the surface after the oxidation test shows that Cr2O3 is the main oxide on a specimen tested at 1000°C, whereas Fe2O3 and Fe3O4 phases also form on a specimen tested at 1100°C, where the weight increases rapidly. The high-temperature oxidation behavior of Fe-14Cr ODS steel is confirmed to be dominated by changes in the Cr2O3 layer and generation of Fe-based oxides through evaporation.

The aim of this report is to understand the status and management of genetic resources on ICRISAT(International Crops Research Institute for the Semi-Arid Tropics) to promote exchange of germplasm and information. ICRISAT genebank at Patancheru, India has the responsibility to collect, conserve, characterize, document and distribute the genetic resources. Also, ICRISAT has performed the estimation of environment tolerance, disease resistance, and functional compounds of genetic resources. ICRISAT has assembled more than 120,000 accessions of chickpea, groundnut, pigeonpea, pearl millet, sorghum, and six small millets. Since 1974 to 2008, ICRISAT provided 1,350,000 accessions with 144 countries to develop new cultivars. The provision pattern of genetic resources in ICRISAT showed that more than 80 % of each crop by the total holdings resources had been offered and that it is the direction of the ideal conserve and management of genetic resources. To evaluate their genetic resources (chickpea, groundnut, pigeonpea, pearl millet, sorghum, and six small millets), they made descritors for each crop and investigated their germplasms. This report would be meaningful to understand utilization and effect of the germplasms to be held at ICRISAT.

This study investigates the thermal shock property of a polycrystalline diamond compact (PDC) produced by a high-pressure, high-temperature (HPHT) sintering process. Three kinds of PDCs are manufactured by the HPHT sintering process using different particle sizes of the initial diamond powders: 8-16 μm (D50 = 4.3 μm), 10-20 μm (D50 = 6.92 μm), and 12-22 μm (D50 = 8.94 μm). The microstructure observation results for the manufactured PDCs reveal that elemental Co and W are present along the interface of the diamond particles. The fractions of Co and WC in the PDC increase as the initial particle size decreases. The manufactured PDCs are subjected to thermal shock tests at two temperatures of 780oC and 830oC. The results reveal that the PDC with a smaller particle size of diamond easily produces microscale thermal cracks. This is mainly because of the abundant presence of Co and WC phases along the diamond interface and the easy formation of Co-based (CoO, Co3O4) and W-based (WO2) oxides in the PDC using smaller diamond particles. The microstructural factors for controlling the thermal shock property of PDC material are also discussed.

Sesquiterpene lactones (SLs) are a group of over 500 compounds, characteristic of the Asteraceae. They are interesting from the chemical and chemotaxonomic point of view, and show antitumour, anti-leukaemic, anti-cardiovascular disease, reduction of inflammation, and anti-microbial activities. The SLs, free lactucin and lactucopicrin, content in 572 accessions of lettuce (Lactuca sp.) germplasm introduced from 30 countries were quantified using high-performance liquid chromatography. Variation range of free lactucin content exhibited trace ~ 235.3 μg from 1g of dried leaves and average was 41.2 ± 1.2 μg (Avr ± SE), variation range 55.0 ~ 3,041.0 μg and average 526.9 ± 17.5 μg in free lactucopicrin content, and variation range 66.3 ~ 3,188.5 μg and average 568.1 ± 18.1 μg in total free SLs content. Lactucopicrin occupied 92.7% of the total SLs content. Among the varietal types, crisphead type exhibited the highest average total free SLs content, next is leaf lettuce, and butterhead type lettuce exhibited the lowest that of content. German accessions exhibited the lowest average total free SLs content, Korean accessions exhibited the highest, and European origin accessions exhibited lower that of content. Red leaf color accessions having higher SLs content than that of green color. Seven accessions having more than 2,000 μg·g-1 dwt of total free SLs content and five accessions having less than 100 μg·g- 1dwt that of content. These accessions can be used as low SLs content cultivar breeding or high SLs content cultivar breeding sources as well as research materials for medical treatment such as, anti-tumour, anti-leukaemic, and antimicrobial activities, etc.

Niobium is one of the most important and rarest metals, and is used in the electronic and energy industries. However, it’s extremely high melting point and oxygen affinity limits the manufacture of Nb coating materials. Here, a Nb coating material is manufactured using a kinetic spray process followed by hot isotactic pressing to improve its properties. OM (optical microscope), XRD (X-ray diffraction), SEM (scanning electron microscopy), and Vickers hardness and EPMA (electron probe micro analyzer) tests are employed to investigate the macroscopic properties of the manufactured Nb materials. The powder used to manufacture the material has angular-shaped particles with an average particle size of 23.8 μm. The porosity and hardness of the manufactured Nb material are 0.18% and 221 Hv, respectively. Additional HIP is applied to the manufactured Nb material for 4 h under an Ar atmosphere after which the porosity decreases to 0.08% and the hardness increases to 253 Hv. Phase analysis after the HIP shows the presence of only pure Nb. The study also discusses the possibility of using the manufactured Nb material as a sputtering target.

A bulk-type Ta material is fabricated using the kinetic spray process and its microstructure and physical properties are investigated. Ta powder with an angular size in the range 9-37 μm (purity 99.95%) is sprayed on a Cu plate to form a coating layer. As a result, ~7 mm-sized bulk-type high-density material capable of being used as a sputter material is fabricated. In order to assess the physical properties of the thick coating layer at different locations, the coating material is observed at three different locations (surface, center, and interface). Furthermore, a vacuum heat treatment is applied to the coating material to reduce the variation of physical properties at different locations of the coating material and improve the density. OM, Vickers hardness test, SEM, XRD, and EBSD are implemented for analyzing the microstructure and physical properties. The fabricated Ta coating material produces porosity of 0.11~0.12%, hardness of 311~327 Hv, and minor variations at different locations. In addition, a decrease in the porosity and hardness is observed at different locations upon heat treatment.

중앙아시아에서 수집한 꽃피는 마늘 A. longicuspis의 주아와 주아를 도입해서 생산한 1년생 통구를 각각 노지에 재배하여 우리나라에서 주아재배를 통한 종구(통구)생산과 통구재배를 통한 마늘생산 가능성을 검토하였다. 평균 월동율은 주아재배에서 77.3%, 통구재배에서는 100%로서 우리나라의 대표적인 재래종인 단양마늘이나 의성마늘에 비하여 훨씬 높아서꽃피는 마늘의 주아와 통구를 중부지방에서 재배함에 있어서월동성은 큰 문제가 되지 않을 것으로 사료되었다. 주아재배에서 월동한 모든 개체가 통구 수확이 가능하였고 통구 형성율은 모든 자원이 100%이었다. 통구재배에서 추대율이 100%이었으며, 재래종 대비 화경장이 길고 주아 수가 많았다. 구크기는 대부분이 재래종에 비하여 작았지만 K248215 자원은구중이 40 g으로서 단양마늘과 비슷하였으며 구당 쪽수는 재래종에 비하여 대부분의 자원이 많았고 화기에 꽃과 주아가동시에 존재하였으며 주아를 제거하지 않은 상태에서는 종자가 맺히지 않았다.

This study investigated the microstructure and wear resistance property of HPHT (high pressure high temperature) sintered PDC (polycrystalline diamond compact) in accordance with initial molding pressure. After quantifying an identical amount of diamond powder, the powder was inserted in top of WC-Co sintered material, and molded under four different pressure conditions (50, 100, 150, 200 kgf/cm2). The obtained diamond compact underwent sintering in high pressure, high temperature conditions. In the case of the 50 kgf/cm2 initial molding pressure condition, cracks were formed on the surface of PDC. On the other hand, PDCs obtained from 100~200 kgf/cm2 initial molding pressure conditions showed a meticulous structure. As molding pressure increased, low Co composition within PDC was detected. A wear resistance test was performed on the PDC, and the 200 kgf/cm2 condition PDC showed the highest wear resistance property.

This study investigates the microstructure and thermal shock properties of polycrystalline diamond compact (PDC) produced by the high-temperature, high-pressure (HPHT) process. The diamond used for the investigation features a 12~22 μm- and 8~16 μm-sized main particles, and 1~2 μm-sized filler particles. The filler particle ratio is adjusted up to 5~31% to produce a mixed particle, and then the tap density is measured. The measurement finds that as the filler particle ratio increases, the tap density value continuously increases, but at 23% or greater, it reduces by a small margin. The mixed particle described above undergoes an HPHT sintering process. Observation of PDC microstructures reveals that the filler particle ratio with high tap density value increases direct bonding among diamond particles, Co distribution becomes even, and the Co and W fraction also decreases. The produced PDC undergoes thermal shock tests with two temperature conditions of 820 and 830, and the results reveals that PDC with smaller filler particle ratio and low tap density value easily produces cracks, while PDC with high tap density value that contributes in increased direct bonding along with the higher diamond content results in improved thermal shock properties.

This study investigated the microstructure and tensile properties of a recently made block-type Ni-Cr-Al powder porous material. The block-type powder porous material was made by stacking multiple layers of powder porous thin plates with post-processing such as additional compression and sintering. This study used block-type powder porous materials with two different cell sizes: one with an average cell size of 1,200 μm (1200 foam) and the other with an average cell size of 3,000 μm (3000 foam). The γ-Ni and γ’-Ni3Al were identified as the main phases of both materials. However, in the case of the 1,200 foam, a β-NiAl phase was additionally observed. The relative density of each block-type powder porous material, with 1200 foam and 3000 foam, was measured to be 5.78% and 2.93%, respectively. Tensile tests were conducted with strain rates of 10−2~10−4 sec−1. The test result showed that the tensile strength of the 1,200 foam was 6.0~7.1 MPa, and that of 3,000 foam was 3.0~3.3 MPa. The elongation of the 3,000 foam was higher (~9%) than that (~2%) of the 1,200 foam. This study also discussed the deformation behavior of block-type powder porous material through observations of the fracture surface, with the results above.

The effect of heat treatment environment on the microstructure and properties of tantalum coating layer manufactured by kinetic spraying was examined. Heat treatments are conducted for one hour at 800oC, 900oC, and 1000oC in two different environments of vacuum and Ar gas. Evaluation of microstructure and physical properties are conducted. High density α- tantalum single phase coating layer with a porosity of 0.04% and hardness of 550 Hv can be obtained. As heat treatment temperature increases, porosity identically decreases regardless of heat treatment environment (vacuum and Ar gas). Hardness of heat treated coating layer especially in Ar gas environment deceases from 550 Hv to 490 Hv with increasing heat treatment temperature. That in vacuum environment deceases from 550 Hv to 530 Hv. The boundary between particles became vague as heat treatment temperature increases. Oxygen distribution of tantalum coating layer is minute after heat treatment in vacuum environment than Ar gas environment.

This study is a basic research for repair material production which manufactured a Cu repair coating layer on the base material of a Cu plate using kinetic spray process. Furthermore, the manufactured material underwent an annealing heat treatment, and the changes of microstructure and macroscopic properties in the Cu repair coating layer and base material were examined. The powder feedstocks were sphere-shaped pure Cu powders with an average size of 27.7μm. The produced repair coating material featured 600μm thickness and 0.8% porosity, and it had an identical α-Cu single phase as the early powder. The produced Cu repair coating material and base material displayed extremely high adhesion characteristics that produced a boundary difficult to identify. Composition analysis confirmed that the impurities in the base material and repair coating material had no significant differences. Microstructure observation after a 500℃/1hr. heat treatment (vacuum condition) identified recovery, recrystallization and grain growth in the repair coating material and featured a more homogeneous microstructure. The hardness difference (δHv) between the repair coating material and base material significantly reduced from 87 to 34 after undergoing heat treatment.

The effect of alpha phase on the fatigue properties of Fe-29%Ni-17%Co low thermal expansion alloy was investigated. Two kinds of alloys (Base alloy and Alpha alloy) were prepared by controlling the minimal alloy composition. Microstructure observation, tensile, high-cycle fatigue, and low-cycle fatigue results were measured in this study. The Base alloy microstructure showed typical austenite γ phase. Alpha alloy represented the dispersed phase in the austenite γ matrix. As a result of tensile testing, Alpha alloy was found to have higher strengths (Y.S. & T.S.) and lower elongation compared to those of the Base alloy. High cycle fatigue results showed that Alpha alloy had a higher fatigue limit (360MPa) than that (330MPa) of the Base alloy. The Alpha alloy exhibited the superior high cycle fatigue property in all of the fatigue stress conditions. SEM fractography results showed that the alpha phase could act to effectively retard both fatigue crack initiation and crack propagation. In the case of low-cycle fatigue, the Base alloy had longer fatigue life in the high plastic strain amplitude region and the Alpha alloy showed better fatigue property only in the low plastic strain amplitude region. The fatigue deformation behavior of the Fe-29%Ni-17%Co alloy was also discussed as related with its microstructure.

This study manufactured a CIG-based composite coating layer utilizing a new warm spray process, and amixed powder of Cu-20at.%Ga and Cu-20at.%In. In order to obtain the mixed powder with desired composition, theCu-20at.%Ga and Cu-20at.%In powders were mixed with a 7:1 ratio. The mixed powder had an average particle size of35.4 µm. Through the utilization of a warm spray process, a CIG-based composite coating layer of 180 µm thicknesscould be manufactured on a pure Al matrix. To analyze the microstructure and phase, the warm sprayed coating layerunderwent XRD, SEM/EDS and EMPA analyses. In addition, to improve the physical properties of the coating layer, anannealing heat treatment was conducted at temperatures of 200℃, 400℃ and 600℃ for 1 hour each. The microstructureanalysis identified α-Cu, Cu4In and Cu3Ga phases in the early mixed powder, while Cu4In disappeared, and additionalCu9In4 and Cu9Ga4 phases were identified in the warm sprayed coating layer. Porosity after annealing heat treatmentreduced from 0.75% (warm sprayed coating layer) to 0.6% (after 600℃/1 hr. heat treatment), and hardness reducedfrom 288 Hv to 190 Hv. No significant phase changes were found after annealing heat treatment.

Fe-Cr-Al powder porous metal was manufactured by using new electro-spray process. First, ultra-finefecralloy powders were produced by using the submerged electric wire explosion process. Evenly distributed colloid(0.05~0.5% powders) was dispersed on Polyurethane foam through the electro-spray process. And then degreasing andsintering processes were conduced. In order to examine the effect of cell size (200 µm, 450 µm, 500 µm) in process,pre-samples were sintered for two hours at temperature of 1450˚C, in H₂ atmospheres. A 24-hour thermo gravimetricanalysis test was conducted at 1000˚C in a 79% N₂ + 21% O₂ to investigate the high temperature oxidation behavior ofpowder porous metal. The results of the high temperature oxidation tests showed that oxidation resistance increased withincreasing cell size. In the 200 µm porous metal with a thinner strut and larger specific surface area, the depletion ofthe stabilizing elements such as Al and Cr occurred more quickly during the high-temperature oxidation compared withthe 450, 500 µm porous metals.

The effect of carrier gases (He, ) on the properties of Ti coating layers were investigated to manufacture high-density Ti coating layers. Cold spray coating layers manufactured using He gas had denser and more homogenous structures than those using gas. The He gas coating layers showed porosity value of 0.02% and hardness value of Hv 229.1, indicating more excellent properties than the porosity and hardness of gas coating layers. Bond strengths were examined, and coating layers manufactured using He recorded a value of 74.3 MPa; those manufactured using gas had a value of 64.6 MPa. The aforementioned results were associated with the fact that, when coating layers were manufactured using He gas, the powder could be easily deposited because of its high particle impact velocity. When Ti coating layers were manufactured by the cold spray process, He carrier gas was more suitable than gas for manufacturing excellent coating layers.

본 연구는 농업유전자원센터에 보존되어있는 불가리아 재래종 고추 유전자원 61 점을 대상으로 농업형질을 조사하고, 22개의 분자마커(SSR marker)를 이용하여 불가리아 재래종 고추 유전자원의 유전적 다양성 및 집단분석을 통하여, 자원보존 및 효율적인 작물 육종을 위한 기초정보를 제공하고자 본실험을 수행하였으며 결과는 다음과 같다. 1. 파종 후 발아까지 소요일수는 최소 11일에서 최대 26 일,평균 16.9 일이었고 개화 소요일수는 최소 48일, 최대 65일, 평균 56.9일이었으며 성숙까지의 소요일수는 최소 73일, 최대 98일, 평균 90.7일이었다. 2. 농업형질의 특성을 바탕으로 PCA 분석을 이용하여 불가리아 고추의 다양성을 분석한 결과, 파종 후 개화까지의 소요일수에 따라 조생종, 중생종, 만생종 3개의 그룹으로 나눌 수있었다. 3. 61점의 고추자원에 대하여 22개 SSR 마커에 의해 나타난 대립유전자 (allele)수는 총 82개였다. 마커당 평균 allele수는 3.7 개였고, allele 수의 범위는 2개에서 5개로 확인되었다. 유전적 다양성을 나타내는 PIC 값의 범위는 0.061-0.636이었으며 평균 PIC 값은 0.349로 확인되었다. 4. 분자마커(SSR)를 이용하여 UPGMA, PCoA, STUCTURE 분석을 통한 고추의 다양성 및 집단 구조를 분석한 결과, 3개의 그룹으로 나뉘어졌다. 결론적으로, 농업형질 특성을 바탕으로 한 불가리아 재래종고추의 다양성과 분자학적 특성을 이용한 다양성 결과와는 차이가 있었다.

딜에 관한 연구는 대부분이 항산화 물질 및 항암효과 등에 관한 연구가 수행되었으며, 유전적 다양성에 대한 연구는 수행되지 않고 있다. 작물의 유전적 다양성 분석은 자원의 보존, 관리 및 새로운 품종 개발 등에 활용될 수 있는 중요한 정보를제공한다. 본 연구는 Dill 유전자원에 대한 유전적 다양성 분석을 위한 마커 선발을 위해 수행하였다. 1. 유전적 다양성 평가를 위하여 Operon사의 OPA, OPB 그리고 OPC 3 set, 60개 RAPD 마커에 대해서 1차 선발 후, 재현성이 있는 마커를 최종 선발하였다. 선발된 RAPD 마커의 다형성 분석을 위하여 국립농업유전자원센터에서 보유중인 dill 자원 16점을 사용하였다. 2. PCR 산물의 크기가 200 bp에서 3,000 bp 사이에 있는band들을 분석한 결과, 마커 당 평균 7 ~ 14개의 단편들을 나타내었다. 총 band 수는 119개였으며, 그 중 109개가 다형성을보였다. 총 12개의 마커 중 7개의 마커는 모든 band가 다형성을 보였고, 나머지 5개 마커는 70%~ 91%가 다형성 band였다. 각각의 마커에 대한 Nei’s gene diversity(H) 지수는 0.13 ~ 0.28였으며, 평균은 0.214이다. Shannon’s information index(I) 지수는 0.23 ~ 0.44이며, 평균은 0.353이다. 3. UPGMA tree에서는 그루지아 원산 1점을 제외한 15점이 3개 군집으로 나누어졌다. 군집 I은 2점, 군집 II는 11점이 포함되었으며, 군집 III에서는 2점이 포함되었다. 본 실험으로 선발된 RAPD marker들은 dill 유전자원에 대한 유전적 다양성 분석에 활용될 수 있을 것이다.

1. 세계 26개국에서 도입된 녹두 유전자원 705점에 대하여16개의 형태적 형질 특성을 이용하여 각각 두 가지의 군집방법, 핵심집단 자원수 결정방법 및 표본추출 방법을 조합하여 총8개의 핵심집단(SUNPR, SUNPPr, UNPR, UNPPr, SUNLR, SUNLPr, UNLR, UNLPr)을 작성하여 원수집단과 비교한바 8개핵심집단 모두 원수집단과는 분산과 평균치에서 차이가 없었다. 2. Nei의 다양성지수는 8개 핵심집단 모두 원수집단 보다높았고, 특히 UNLPr이 가장 높았으며, UNPR은 다른 핵심집단에 비하여 상대적으로 낮은 지수를 보였다. 3. 원수집단과 핵심집단간 자원분포의 동질성을 파악하기 위하여 카이자승 검증을 한 결과 12개 양적형질과 1개의 질적형질(종피색)은 모든 핵심집단이 동질분포를 보였으나 3개의질적 형질 (배축색, 종피광택, 생육습성)은 핵심집단에 따라서동질분포를 하는 것과 그렇지 않은 것이 있었으며, 8개 핵심집단 중 UNPPr은 동질성이 가장 높았다. 평균차율(MD%)과일치율(CR%)은 8개 핵심집단 모두 유의한 수준을 보였다. 4. 8개의 모든 핵심집단이 원수집단과 평균치에서 차이가 없고, 높은 다양성을 과 동질한 분포를 보이며, 평균차율(MD%)과 일치율(CR%)이 유의한 수준을 보여 원수집단의 다양성을잘 나타내는 것으로 해석되었다. 5. 핵심수집단 크기(10%와 15%)에 따른 다양성은 유의한차이가 없었으며, 8개의 핵심집단 중 평균치, 동질분포, 일치율 및 도복내성을 고려할 때 UNPPr이 가장 좋은 핵심집단으로 사료되었다.

A new manufacturing process of Fe-Cr-Al powder porous metal was attempted. First, ultra-fine fecralloy powders were produced by using the submerged electric wire explosion process. Evenly distributed colloid (0.05~0.5% powders) was dispersed on PU (Polyurethane) foam through the electrospray process. And then degreasing and sintering processes were conduced. In order to examine the effect of sintering temperature in process, pre-samples were sintered for two hours at temperatures of , , , and , respectively, in atmospheres. A 24-hour TGA (thermo gravimetric analysis) test was conducted at in a 79% +21% to investigate the high temperature oxidation behavior of powder porous metal. The results of the high temperature oxidation tests showed that oxidation resistance increased with increasing sintering temperature (2.57% oxidation weight gain at sintered specimen). The high temperature oxidation mechanism of newly manufactured Fe-Cr-Al powder porous metal was also discussed.

Cold spray deposition using Titanium powder was carried out to investigate the effects of powder morphology and powder preheating on the coating properties such as porosity and hardness. The in-flight particle velocity of Ti powder in cold spray process was directly measured using the PIV (particle image velocimetry) equipment. Two types of powders (spherical and irregular ones) were used to manufacture cold sprayed coating layer. The results showed that the irregular morphology particle appeared higher in-flight particle velocity than that of the spherical one under the same process condition. The coating layer using irregular morphology powder represented lower porosity level and higher hardness. Two different preheating conditions (no preheating and preheating at ) were used in the process of cold spraying. The porosity decreased and the hardness increased by conducting preheating at . It was found that the coating properties using different preheating conditions were dependent not on the particle velocity but on the deformation temperature of particle. The deposition mechanism of particles in cold spray process was also discussed based on the experimental results of in flight-particle velocity.

미얀마는 한국에 비해 3배 큰 국토를 가진 동남아시아 국가이며 다양한 기후대가 분포하여 생물상이 다양하다. 미얀마에 서는 농업이 가장 중요한 산업으로 농업자원에 대해 중요하게 생각하며, 농업유전자원보존을 위해, 1990년에 농업관개부 산하 농업연구청에 소속된 종자은행이 설립하였으며. 이곳에는 단기저장시설에 벼 6,302점을 비롯하여 10,108점이, 중기저장 시설에 벼 6,250점을 포함하여 9,905점, 합계 20,013점이 보존되고 있다. 한편, 미얀마의 유용식물자원은 185과 1,528종으로 정리되어지며, 이중 41과 59종의 약용식물이 다양한 병 치료에 이용되어진다. 농업관개부 산하에 약용식물원을 조성하여, 말라리아 치료용 517점, 결핵치료용 712점의 허브자원, 기타 약용식물 6,090점, 희귀 약용식물 4,055점 등을 현지 내 보존 중이다.

본 연구는 농업유전자원센터에 보존되어있는 우리나라 및 불가리아 재래종 강낭콩 유전자원 130점을 대상으로 형태적특성을 조사하고, 155점에 대해 분자마커를 이용하여 우리나라와 불가리아 재래종 강낭콩 유전자원의 유전적 다양성을 분석하였으며 결과는 다음과 같다. 1. 개화일수는 최소 50일에서 최대 79일, 평균 54.5일이었으며 성숙일수는 최소 25일, 최대 64일, 평균 38.9일 이었고 생육일수는 최소 83일, 최대 123일, 평균 93.4일이었다. 불가리아 재래종 자원들이 한국 재래종 자원보다 개화일수는 3.1일, 성숙일수는 3.6일, 생육일수는 6.7일 늦은 것으로 조사되었다. 2. 공시자원의 100립중은 19~71g 사이에 분포하였고, 평균 100립중은 41.2 g이었으며, 우리나라 재래종 자원은 평균 100립중이 40.9 g, 불가리아 재래종 자원은 42.4 g 이었다. 3. 조사대상 자원의 질적형질 중 생육습성은 한국 자원은 직립형이 87.6%인 반면 불가리아 자원은 덩굴성이 60.0%였으며, 한국 자원의 화색은 보라색 줄무늬가 있는 백색이 80%로 가장 많았으나 불가리아 자원은 백색자원이 52%를 차지하였다. 종피색은 한국 자원은 적색이 61%, 불가리아 자원은 백색이48%를 차지하여 국가간 선호도와 용도에 따른 차이가 있을것으로 보였다. 4. 10개의 SSR 마커를 이용하여 다양성을 분석한 결과 PIC 0.6181을 얻었으며, 국가별 분석 결과 다양성은 gene diversity와 PIC로 볼 때 불가리아 자원이 다양성이 높은 것으로 조사되어 불가리아에서 도입한 강낭콩 유전자원이 강낭콩 수집단의 유전적 다양성 증대에 기여한 것으로 평가된다.

This study investigated the effects of annealing environment for the densification and purification properties of pure titanium coating layer manufactured by cold spraying. The annealing was conducted at /1 h and three kinds of environments of vacuum, Ar gas, and mixture gas were controlled. Cold sprayed Ti coating layer (as sprayed) represented 6.7% of porosity and 228 HV of hardness, showing elongated particle shapes (severe plastic deformation) perpendicular to injection direction. Regardless of gas environments, all thermally heat treated coating layers consisted of pure -Ti and minimal oxide. Vacuum environment during heat treatment represented superior densification properties (3.8% porosity, 156.7 HV) to those of Ar gas (5.3%, 144.5 HV) and mixture gas (5.5%, 153.1 HV). From the results of phase analysis (XRD, EPMA, SEM, EDS), it was found that the vacuum environment during heat treatment could be effective for reducing oxide contents (purification) in the Ti coating layer. The characteristic of microstructural evolution with heat treatment was found to be different at three different gas environments. The controlling method for improving densification and purification in the cold sprayed Ti coating material was also discussed.

China is a one of the largest agricultural countries in the world. China consumes around 12.5 billion kilograms of seeds each year. Suchhuge demand for seeds has made the Chinese seed market more and more attractive for investment. Through analysis on the present situation and existing problems of the seed industry in China and based on the current Chinese seed industry development, some future prospects for investments are indicated. This investigation was carried out to propose the appropriate strategies on the development of the Korea seed industry as it considers its entry into the China seed market as a new growth engine in the agricultural sector. The basic law regulating the Chinese seed industry is the PRC Seed Law that generally refers to the protection of germplasm resources, verification of varieties, seed quality issues, the import and export of seeds, seed administrative management, and various rights and obligations. The regulations were aimed at the protection of the rights concerning new varieties of plants. China has two main industry associations, the National Seed Association and the China Seed Industry IP Union, that are non-profit associations consisting of entities and people engagin in the seed scientific research, production, operation and management. The China National Seed Group Co., Ltd. (“Sino Seeds”) is the market leader in China regarding the seed industry. The chinese government, however, encourages investment from multinational companies as well as importation of modern crop planting management technologies and equipment. It supports the entry of investors with proven experiences in breeding and germplasm resources expansion and R&D. There has never been a better time for multinational companies with proven seed industry experience to look at building relationships with the Chinese government and enterprises.

국화과(Compositae)는 현화식물 중 세계에서 가장 넓게 분포하고, 쌍자엽식물 중 가장 진화된 식물분류군이며, 우리나라에는 약 300여종이 존재하는 것으로 알려져 있다. 구절초, 감국, 쑥, 쑥갓, 개미취, 참취, 곰취 등 국화과 식물들은 예로부터 민간에서 약용 및 식용 소재로써 다양하게 사용되어왔다. 본 연구는 국화 및 국화근연종 유용유전자원 선발을 통하여 육종 소재를 확대하고, 중간모본 및 신품종 육성기반을 구축하고자 DNA 마커시스템의 개발을 위해 수행되었다. 1. 화단국인 Smileball(Dendranthema grandiflorum) 품종을 사용하여 SSR-enriched library를 작성하였고, GS FLX 분석을 통해 18.83Mbp의 염기서열 결과를 얻었으며, read의 평균 길이는 280.06bp로 나타났다. 2. 단순반복염기서열(SSR) 부위를 포함하는 26,780개 clones 중 di-nucleotide motifs가 16,375개(61.5%)로 우세하였고, trinucleotide motifs(6,616개, 24.8%), tetra-nucleotide motifs(1,674개, 6.3%), penta-nucleotide motifs(1,283개, 4.8%), hexa-nucleotide motifs(693개, 2.6%) 순으로 나타났다. 3. 얻어진 di-nucleotide motifs들 중에서는, AC/CA class가 93.5%로 대부분이었고, tri-nucleotide motifs에서는 AAC class가 50.5%, tetra-nucleotide motifs는 ACGT class가 43.6%이고, pentanucleotide motif에서는 AACGT class 27.2%이며, hexa-nucleotide motif에서는 ACGATG class 21.8%였다. 4. 얻어진 염기서열 결과를 토대로 다양한 motif를 갖는 100개의 SSR 마커를 제작하였고, 차후 이를 활용하여 국화 유전자원의 다형성 및 유전자형 분석을 통해 분자유전학적 다양성 및 집단의 구조분석이 가능하고, 국화의 분자육종기반 구축을 위한 유용한 도구가 될 것 이다.

본 연구는 농업유전자원센터에 보존되어있는 우리나라 원산재래종 팥 유전자원 164점을 대상으로 농업기초형질을 조사하고, 팥 근연종을 포함하여 180점을 대상으로 분자마커를 이용하여 우리나라 재래종 팥 유전자원의 유전적 다양성을 분석한결과는 다음과 같다. 1. 기초 특성조사 된 자원의 개화일수는 최소 44일에서 최대 83일, 평균 67.1일이었으며 성숙일수는 최소 27일, 최대 42일, 평균 34.2일 이었고 생육일수는 최소 83일, 최대 118일, 평균 101.2이었다. 조사된 자원들은 북한원산자원들이 남한원산자원들보다 다소 일찍 개화하나 늦게성숙하는 경향을 보였다. 2. 대비품종인 충주팥의 개화일수는 65일, 성숙일수는 42일, 생육일수는 107일로 대비품종에 비해 우리 재래종 팥 자원의 평균개화일수는 약 2일 늦은 반면 성숙일수는 약 8일정도 빨랐고, 생육일수는 약 6일정도 빨라 평가 대상재래종자원은 대비품종인 충주팥에 비해 조숙종이 많은것으로 조사되었다. 3. 본 시험에 이용된 우리나라 재래종 자원은 일본의 기상생태형에 배치해본 결과 비교적 조생종에 속하는 것으로분석되었다. 4. 10개의 SSR 마커를 이용하여 다양성을 분석한 결과 PIC0.70을 얻었으며, 집단별로 분석한 결과 다양성은 야생종집단이 가장 다양성이 높고 남한원산 자원이 가장 낮은것으로 조사되었다.

This study attempted to manufacture a Cu-15 at.%Ga coating layer via the cold spray process and investigated the effect of heat treatment environment on the properties of cold sprayed coating material. Three kinds of heat treatment environments, +argon, pure argon, and vacuum were used in this study. Annealing treatments were conducted at /1 hr. With the cold sprayed coating layer, pure -Cu and small amounts of were detected in the XRD, EDS, EPMA analyses. Porosity significantly decreased and hardness also decreased with increasing annealing temperature. The inhomogeneous dendritic microstructure of cold sprayed coating material changed to the homogeneous and dense one (microstructural evolution) with annealing heat treatment. Oxides near the interface of particles could be reduced by heat treatment especially in vacuum and argon environments. Vacuum environment during heat treatment was suggested to be most effective one to improve the densification and purification properties of cold sprayed Cu-15 at.%Ga coating material.

W-ZrC and W-HfC composite powders were fabricated by the Plasma Alloying & Spheroidization (PAS) method and the powders were sprayed into hybrid coating layers by using Low Vacuum Plasma Spray (LVPS) process, respectively. Microstructure, mechanical properties, and ablation characteristics of the fabricated coating layers were investigated. The LVPS process led to successful production of W-Carbide hybrid coatings, approximately 400 or above in thickness. As the substrate preheating temperature increased from to , the hardness of the W-ZrC coating layer increased due to decreased porosity. Vickers hardness showed higher value (about 108.4 HV) in W-ZrC hybrid coating material compared to that of W-HfC while adhesive strength was found to be similar in both coating layers. The plasma torch test revealed good ablation resistance of the W-Carbide hybrid coating layers. The relatively high performance W-ZrC coating layer at the elevated temperature is thought to be attributed to both the strengthening effect of ZrC particle remained in the layer and the formation of ZrO2 phase with high temperature stability.

This study investigated the high temperature oxidation behavior of Ni-22.4%Fe-22%Cr-6%Al (wt.%) porous metal. Two types of open porous metals with different pore sizes of 30 PPI and 40 PPI (pore per inch) were used. A 24-hour TGA test was conducted at three different temperatures of , and . The results of the BET analysis revealed that the specific surface area increased as the pore size decreased from 30 PPI to 40 PPI. The oxidation resistance of porous metal decreased with decreasing pore size. As the temperature increased, the oxidation weight gain of the porous metal also increased. Porous metals mainly created oxides such as , , , and . In the 40 PPI porous metal with small pore size and larger specific surface area, the depletion of stabilizing elements such as Al and Cr occurred more quickly during oxidation compared to the 30 PPI porous metal. Ni-Fe-Cr-Al porous metal's high-temperature oxidation micro-mechanism was also discussed.

Garlic (Allium sativum L.) has been used as both food and medicine in many cultures for thousands of years. Garlic cultivars are completely sterile and propagated through vegetative method. Collection of a large number of fertile accessions of these genus is needed to explore genetic variability. In order to investigate genetic variation among Allium species and its possibilities for direct cultivation in Korea, we characterized 12 accessions of A. longicuspis, flowering wild garlic which had collected from Central Asia, the main center of garlic diversity. Most of A. longicuspis accessions showed higher over-wintering and bolting rate, longer scape length and more number of bulbils than Korean landraces cultivar, Danyang and Euiseong, but A. longicuspis accessions exhibited smaller size of bulbs and bulbils. Most accessions of A. longicuspis had more number of cloves per bulb, except K229596 and K248824 than Korean landraces. All the accessions of A. longicuspis from Central Asia had complete bolters having many flowers and topsets in umbel. Further studies of A. longicuspis should focus on securing true seeds through removal of topsets and crosses among accessions to create the genetic variability.

토마토는 남아메리카 서부 고원지대가 원산지이며 전 세계에 널리 재배되고 있는 가지과 작물이다. 최근 토마토의 건강 증진 효과에 대한 연구와 소비의 다양성으로 인해 재배 및 생산량이 증가함과 동시에 다량으로 발생하는 부산물 활용 방안 수립에 대한 관심이 증가하였다. 따라서 토마토 42자원 잎 추출물의 항산화 활성과 flavone aglycones를 분석하여 기능성 소재의 활용 가능성을 보고자 하였다. 토마토 잎 추출물의 DPPH 라디칼 소거 활성 검정 결과, IT191046 (CHN, 130.9 ± 1.2 ug/ml)이 가장 높았고 IT207234 (BTN, 376.7 ± 14.1 ug/ml)가 가장 낮았으며 ABTS의 경우 IT189949 (IND, 1348.6 ± 36.4 ug/ml)이 가장 높았고 IT259255 (TWN, 3789.3 ± 84.4 ug/ml)가 가장 낮았다. 총 폴리페놀 함량은 IT207214 (NPL, 59.9 ± 0.0 mg GAE g-1)이 가장 높았고 IT203262 (RUS, 16.8 ± 0.3 mg GAE g-1)가 가장 낮았다. 토마토 잎 추출물의 총 flavone aglycones 함량을 분석한 결과, IT229711 (KOR, 78.9 ± 1.0 ug/mg)가 가장 높았다. myricetin, quercetin, naringenin, kaempferol, isorhamnetin 함량은 각각 0.08 ~ 0.28 ug/mg, 0.6 ~ 24.1 ug/mg, 1.4 ~ 53.1 ug/mg, 0.19 ~ 4.73 ug/mg, 0.06 ~ 0.42 ug/mg 이었으며 특히 isorhamnetin은 88% (37 자원)가 검출한계치 (0.05 ug/mg) 미만이었다. 토마토 잎 추출물의 항산화 활성과 flavone aglycones 함량의 상관관계를 분석한 결과, DPPH와 ABTS 라디칼 소거 활성은 높은 정의 상관을 보였으며, 이 두 활성 모두 myricetin과 정의 상관을 나타냈다. 또한 총 flavone aglycones 함량은 quercetin, naringenin, isorhamnetin과 높은 정의 상관을 보였다. 이 연구 결과를 토대로 토마토 잎의 기능성 소재로의 이용 가능성을 확인 할 수 있었고 토마토 부산물 활용을 위한 다양한 활용 방안 수립에 도움이 될 것으로 사료 된다.

토마토는 남아메리카 서부 고원지대가 원산지이며 전 세계적으로 재배 및 생산되고 있는 가지과 작물로 토마토에 함유된 steroid glycoalkaloids 화합물은 미생물이나 곤충에 독성을 나타내지만 최근 항염증, 항균 등의 생리활성을 나타내는 것으로 밝혀졌다. 따라서 토마토 42자원 잎 추출물의 항염증 활성을 검정하고 steroid glycoalkaloids 함량을 비교하고자 하였다. 토마토 잎 추출물이 RAW 264.7 세포주에 미치는 독성 효과를 알아본 결과, 추출물 처리 농도 범위 (20 ~ 100 ug/m)l 안에서 RAW 264.7 세포주가 50%이상 생존하였고, 추출물의 농도가 증가할수록 세포 생존율이 감소하는 것을 확인할 수 있었다. 이것은 추출물 자체가 세포에 독성으로 작용하지 않아 세포가 생존 가능한 범위 안에서 실험이 가능함을 의미하여 같은 농도 범위의 추출물로 항염증 활성을 검정하였다. 20 ug/ml의 추출물을 처리한 경우 14.1%의 낮은 nitric oxide (NO) 생성 저해율을 보였고 50 ug/ml을 처리 시 79.4%까지 증가하였으며 100 ug/ml 처리 시 98.9%의 높은 저해율을 보였다. 각 자원의 IC50 값을 비교한 결과 IT173907 (BRA, 84.0 ± 0.1 ug/ml)이 가장 높은 저해 활성을 보였고 IT211836 (JPN, 130.7 ± 2.5 ug/ml)이 가장 낮았다. 또한 steroid glycoalkaloids를 분석한 결과, tomatine 함량은 IT203466 (AUS, 8.2 ± 0.6 100 ug/mg)이 가장 높았고 IT229711 (KOR, 2.5 ± 0.5 100 ug/mg)가 가장 낮았다. 또한 tomatidine의 경우, IT173906 (BRA, 1.41 ± 0.22 100 ug/mg)이 가장 높았고 IT235444 (THA, 0.28±0.07 100 ug/mg)가 가장 낮았다. 토마토 잎 추출물의 항염증 활성과 steroid glycoalkaloids 함량의 상관관계를 분석한 결과, tomatine과 tomatidine은 높은 정의 상관관계를 보였으나 두 물질과 nitric oxide (NO) 생성 저해 활성은 유의적 상관관계를 보이지 않았다. 본 연구의 결과를 통해 토마토 잎 추출물의 tomatine, tomatidine 함량과 항염증 활성의 상관관계를 확인할 수는 없었지만, 토마토 잎의 천연 항염증제로의 활용 가능성을 확인하였고 토마토 부산물의 다양한 활용 방안 수립에 도움이 될 것으로 사료 된다.

인삼 개갑종자의 초저온보존 효과 및 최적조건을 구명하기 위하여 건조 조건과 수분함량 및 액체질소 보존 전 동결처리와 보존 후 해동처리에 따른 초저온보존 효과를 조사하였다. 건조처리는 25℃ air flow 챔버(RH 10～12%)와 15℃ 건조실(RH 22～25%)을 이용하여 실시하였고 보존 전 동결은 –24℃에서 30일간 처리하였으며 보존 후 해동은 4℃에서 24시간, 40℃에서 2분 처리구를 각각 비교하였다. 그 결과 15℃에서 종자수분 8-12%로 건조된 종자가 보존 전 처리 없이 액체질소에 보존된 후 40℃에서 해동되었을 때 발아율이 가장 높은 것으로 나타났다. 그러나 종자수분이 2.2% 이하일 때 건조가 지속되면 발아율은 감소하는 것으로 나타났으며, 4% 이하에 이르면 보존 전후 처리효과는 나타나지 않는 것으로 조사되었다. 반면 25℃에서 건조된 종자는 상대적으로 높은 발아율을 유지하였다. 건조 및 초저온보존에 의한 인삼 개갑 종자의 유근 및 자엽 생장율을 조사한 결과, GA배지 치상 10일 후 무처리한 대조구에서 첫 유근이 출현하였으며 3주 후에는 자엽발달이 시작되었다. 30일째에는 자엽생장율이 유근발달과 함께 유의하게 증가하는 것으로 나타났다. 치상 30일까지 초저온보존에 의한 생장율은 같은 양상을 보이면서 대조구보다 현저히 낮게 나타났으나 40일째에는 양상은 같았으나 회복율이 대조구보다 증가세를 보였다. 또한 보존 전 동결처리 없었던 종자는 동결처리한 종자보다 모든 처리구에서 높은 유근 및 자엽 생장율을 보였다.

농촌진흥청 농업유전자원센터에 보존되고 있는 우리나라 재래종 벼 유전자원 중 선발된 394품종의 미질과 관련된 특 성을 분석하고 상호관계에 대한 결과는 다음과 같다. 1. 단백질 함량은 5.2~9.9%까지 다양한 분포를 보였고, Mg함량은 12.7 mg에서 37.7 mg까지의 넓은 범위의 분포를 보였으며, K함량 또한 60.0 mg에서 125.9 mg 까지의 넓은 범위의 분포를 나타냈고, 차진정도의 지 표로 사용되는 Mg/K 비율은 일품벼보다 높게 분포하 였다. 2. 쌀의 차진정도를 결정하는 주된 인자이며 미질을 나타 내는 척도의 하나인 아밀로스 함량은 현재 우리나라 밥쌀용 수도 장려품종들이 대체로 18～20% 수준에 있는데 비하여 재래종 유전자원에서 메벼의 범위가 12.4～28.9%였고 18～20% 범위에 있는 품종은 144 품종이었다. 3. KOH에 의한 알카리붕괴도는 0.0~7.0까지 분포하였는 데 일품벼의 6.4와 유사한 품종이 95품종이었다. 4. Toyo 식미계를 이용한 식미 검정에서 현재 양식미 품 종으로 평가받고 있는 일품벼와 유사한 품종이 16품 종이고, 우리나라 사람들이 양식미로 선호하는 호화온 도가 낮고 Toyo 식미치가 높은 품종은 IT 173444번, 008530번, IT 006554번이 대표적 이었다.

농촌진흥청 농업유전자원센터에서 보유하고 있는 재래조 유전자원 325점을 대상으로 2007년에서 2008년, 2년에 걸쳐 단국대학교 전작과 포장에서 재배하여 출수기, 간장, 수형, 성숙기, 종피색, 1수립수, 천립중 등의 작물학적 특성을 조사하였고, 동시에 이들 자원의 이미지특성을 확보하기 위하여 출수기에 전식물체, 성숙기에 이삭, 수확후에 종실의 영상자료를 제작하였으며, 메찰성 분석은 농업유전자원센터에서 증식된 종실자원으로 요드반응을 조사하였다. 재래조 유전자원 325점은 용도별로 메조 49%(159점), 차조 51%(166점)로 나눌 수 있었으며, 메조, 차조를 합쳐서 강원도 29%, 경북도 25%, 경기도12% 순으로 수집도수분포가 높았다. 용도별 남한지역별 분포는 메조에서는 경북도가 전체의 22%, 차조에서는 강원도가 전체의 17%로 가장 높은 분포를 보이고 있어 용도별 지역특이성이 뚜렷하였다. 이삭모양 분포는 메조, 차조 공히 원통형 42%, 원추형 31% 순으로 가장 높았고, 또한 간장은 메조에서 장간이나 단간이 많았으며, 숙기는 메조에서는 조생종이, 차조에서는 만생종이 수집분포비율이 높아 용도별 특이성도 뚜렷한 경향이었다. 재래조 중 대표적인 자원은 극조생이며 곤봉형인 자원은 삼척메조-2(IT103288), 극조생이며 원통형인 자원은 강화차조-10(IT209312), 극조생이며 방추형인 자원은 강화차조-11(IT209313), 중생이며 선단분지형은 정선차조(IT104454), 중생이며 분지형인 자원은 화성차조-1(IT103755), 극만생이며 원추형인자원은밀양차조(IT185955)등 이었다. 본 연구에 활용된 다양한 한국 재래조 유전자원은 자원주권 확보 및 육종소재로서의 활용도가 높을 것으로 생각된다.

농촌진흥청 농업유전자원센터에서 보유하고 있는 재래옥수수 유전자원 940점을 대상으로 2008년에서 2012년의 5개년에 걸쳐 강원도원 홍천옥수수시험 포장에서 재배하여 출사기, 간장, 착수고, 엽형, 주간엽수, 자수열수, 종피색, 1수립중, 백립중 등의 작물학적 특성을 조사하였고, 동시에 이들 자원의 이미지특성을 확보하기 위하여 웅수출현기에 전식물체, 성숙기에 이삭, 수확후에 종실의 영상자료를 제작하였으며, 메찰성 분석은 홍천옥수수시험장에서 증식된 종실자원으로 요드반응을 조사하였다. 재래옥수수 유전자원 940점은 용도별로 메옥수수 48%(453점), 찰옥수수 43%(407점), 사료용옥수수 5%(47점)로 나눌 수 있었으며, 재래옥수수 지역별 분포는 강원도 21%, 충남도 15%, 경남도9% 순으로 분포가 높았다. 용도별 지역별 분포는 메옥수수에서는 지역간 차이가 없었으나, 찰옥수수에서는 강원도가 전체의 17%로 높은 분포를 보이고 있어 용도별 지역특이성이 큰 경향이었다. 또한 간장은 메옥수수에서 장간이나 단간이 많았으며, 숙기는 메옥수수에서는 조생종이, 찰옥수수에서는 만생종의 분포비율이 다소 높아 용도별 특이성도 인정되었다. 수당립중과 백립중은 메옥수수가 찰옥수수 보다 대체로 무거운 경향이었다. 재래옥수수 중 대표적인 유망한 자원은 흰찰옥수수에서는『서천찰 IT208593』이 극조생,『고성찰, IT195284』이 조생,『홍천찰17, K 139943』이 중생,『평창찰11, IT026524』이 만생으로 유망하였으며, 검정찰옥수수에서는『금산찰15 K140119』이 중생, 『성주찰 IT208576』이 만생,『미상찰 8 IT178746』이 극만생종으로 유망하였다. 본 연구에 활용된 다양한 한국 재래옥수수 유전자원은 자원주권 확보 및 육종소재로서의 활용도가 높을 것으로 생각된다.

This study was undertaken to develop a technique of discrimination using SSR makers in boxthorn cultivars.Forty one boxthorn cultivars, which were collected from Korea and China, were evaluated by 10 SSR markers. Total of 61alleles were detected, ranging from 3 to 13 with an average of 6.1 alleles per locus. The averages of gene diversity and PICvalues were 0.482 and 0.428, with a range from 0.25 (GB-LCM-022 and GB-LCM-087) to 0.83 (GB-LCM-167) and from0.24 (GB-LCM-022 and GB-LCM-087) to 0.81 (GB-LCM-167), respectively. Five markers out of 10 markers, GB-LCM-022, GB-LCM-075, GB-LCM-104, GB-LCM-167 and GB-LCM-217, were selected as key markers for discrimination inboxthorn cultivars. All of boxthorn cultivars were individually distinguished by the combination of five SSR markers.