• Agricultural and Biosystems Engineering
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• v.7 no.1
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• pp.1-7
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• 2006

A need exists to monitor and control the localized high temperatures often experienced in solar grain dryers, which result in grain cracking, reduced germination and loss of cooking quality. A verified finite element model would be a useful to monitor and control the drying process. This study examined the feasibility of the finite element method (FEM) to predict temperature distribution in solar grain dryers. To achieve this, an indirect solar grain dryer system was developed. It consisted of a solar collector, plenum and drying chambers, and an electric fan. The system was used to acquire the necessary input and output data for the finite element model. The input data comprised ambient and plenum chamber temperatures, prevailing wind velocities, thermal conductivities of air, grain and dryer wall, and node locations in the xy-plane. The outputs were temperature at the different nodes, and these were compared with measured values. The ${\pm}5%$ residual error interval employed in the analysis yielded an overall prediction performance level of 83.3% for temperature distribution in the dryer. Satisfactory prediction levels were also attained for the lateral (61.5-96.2%) and vertical (73.1-92.3%) directions of grain drying. These results demonstrate that it is feasible to use a two-dimensional (2-D) finite element model to predict temperature distribution in a grain solar dryer. Consequently, the method offers considerable advantage over experimental approaches as it reduces time requirements and the need for expensive measuring equipment, and it also yields relatively accurate results.

• Korean Journal of Agricultural Science
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• v.47 no.1
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• pp.105-117
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• 2020

Abiotic stress is one of the most serious problems in plant productivity because it dramatically delays plant growth and development. One of the abiotic stresses, soil salinity, has an adverse effect on plant growth, particularly in areas where irrigation is necessary like semiarid Asia and Africa. Among several physiological parameters, anthocyanin accumulation is a valuable indicator of the condition of the plant, and it tends to increase under salt stress conditions because of its protective role in such an environment. Consequently, it may be important to search for well adapted genotypes for upcoming climate changes. Anthocyanins are known to have important roles in defense against biotic and abiotic stresses, providing important functions for protecting plant cells from reactive oxygen species. In this study, we investigated the anthocyanin accumulation between two Korean sorghum genotypes, Sodamchal and Nampungchal. The two genotypes were subjected to a regulated salinity condition, and the anthocyanin contents were evaluated in both. In Nampungchal, the anthocyanin content increased with 150 mM NaCl treatment during the time course of the experiment. However, the anthocyanin content of Sodamchal decreased in the same condition. The measured values of the anthocyanin content should be useful to identify the intensity of the salt tolerance in Sorghum bicolor L. Furthermore, we studied gene expression profiling of salt stress related genes with qRT-PCR. These results suggest that Nampungchal is a more tolerant genotype to salt stress compared to Sodamchal. This information should be useful for breeding salt-resistant cultivars in sorghum.

• Journal of Biosystems Engineering
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• v.38 no.4
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• pp.312-317
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• 2013

Purpose: Conventional methods used to evaluate seeds viability are destructive, time consuming, and require the use of chemicals, which are not feasible to implement to process plant in seed industry. In this study, the effectiveness of Fourier transform near infrared (FT-NIR) spectroscopy to differentiate between viable and nonviable watermelon seeds was investigated. Methods: FT-NIR reflectance spectra of both viable and non-viable (aging) seeds were collected in the range of 4,000 - 10,000 $cm^{-1}$ (1,000 - 2,500 nm). To differentiate between viable and non-viable seeds, a multivariate classification model was developed with partial least square discrimination analysis (PLS-DA). Results: The calibration and validation set derived from the PLS-DA model classified viable and non-viable seeds with 100% accuracy. The beta coefficient of PLS-DA, which represented spectral difference between viable and non-viable seeds, showed that change in the chemical component of the seed membrane (such as lipids and proteins) might be responsible for the germination ability of the seeds. Conclusions: The results demonstrate the possibility of using FT-NIR spectroscopy to separate seeds based on viability, which could be used in the development of an online sorting technique.

• Journal of Biosystems Engineering
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• v.42 no.3
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• pp.227-233
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• 2017

Purpose: Morphological properties of soybean roots are important indicators of the vigor of the seed, which determines the survival rate of the seedlings grown. The current vigor test for soybean seeds is manual measurement with the human eye. This study describes an application of a machine vision technique for rapid measurement of soybean seed vigor to replace the time-consuming and labor-intensive conventional method. Methods: A CCD camera was used to obtain color images of seeds during germination. Image processing techniques were used to obtain root segmentation. The various morphological parameters, such as primary root length, total root length, total surface area, average diameter, and branching points of roots were calculated from a root skeleton image using a customized pixel-based image processing algorithm. Results: The measurement accuracy of the machine vision system ranged from 92.6% to 98.8%, with accuracies of 96.2% for primary root length and 96.4% for total root length, compared to manual measurement. The correlation coefficient for each measurement was 0.999 with a standard error of prediction of 1.16 mm for primary root length and 0.97 mm for total root length. Conclusions: The developed machine vision system showed good performance for the morphological measurement of soybean roots. This image analysis algorithm, combined with a simple color camera, can be used as an alternative to the conventional seed vigor test method.

• Proceedings of the Botanical Society of Korea Conference
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• 1987.07a
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• pp.191-211
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• 1987

Common usage of the concept of juvenility implies that there is one physiological phase, the juvenile phase, which manifests itself in the various morphological and physiological phenomena observed in juvenile higher plants. The juvenile phase is often defined as that time from seed germination until the plant attains the ability to flower regulating such behaviour. This definition precludes plants from flowering in the juvenile phase. It is of major interest, therefore, to identify the physiological controls(Bluehreife) regulating such behavior. The length of the juvenile period in higher plants ranges from one year to over 60 years in different species. The long juvenile period of seedling is the main cause of the long duration of the breeding process. I determined the length of the juvenile period in various plants and its control of phase changes in natural system in relation to factors such as plant size and age, shoot morphology, apex size, root system and phytohormonal and nutritional status is reviewed. From the own experimental and observational evidence available it appears that both hormonal and nutritional factors can be involved in control of juvenility but that a specific juvenile or flowering hormone is not involved. Grafting, ringing, scoring, root pruning and fertilization have been used to accelerate flowering, but in most cases these cultured treatments are only successful on plants that were passed the juvenile phase. It is suggested that there are intrinsic difference between the meristematic cells of the apieces of juvenile and adult shoot, which are thus determined with respect to there development potentialities. The problems associated with the maintenance of the determined state through mitosis are discussed. The properties of transitional forms of Ribes nigrum L. intermediate between the juvenile and adult phase, are descrived and there implications discussed. Analogies are drawn between juvenile phenomena in woody perennials and in herbaceous species.

• Korean journal of applied entomology
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• v.21 no.4 s.53
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• pp.207-210
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• 1982

The studies were carried out to examine susceptibility or resistance of junipers as an inform ediate host of pear rust, to select effective fungicides to pear and juniper rust, and to determine their application time. The telia were formed abundanty on Juniperus chinensis var. kaizuka, moderately on J. chinensis, J. chinensis var. sargentii and J. virginiana, but little on J. chinensis var. globosa and J. utilis. The telia from the junipers were pathogenic to pear. Spraying juniper host with the fungicide Actidione in the 1st and End parts of April greaty inhibited swelling of telia as well as germination of teliospores. The two or three applications of Bayleton at the end of April to May 10 were remarkably effective for the control of pear rust. Fungicide sprays just before rain were more effective than those after rain.

• Journal of Radiation Industry
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• v.4 no.4
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• pp.297-306
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• 2010

Due to the increasing incidence of diabetes, obesity and hypertensive, stevia has been placed great attentions as the sweetener to substitute sucrose in the world. Stevia was introduced to Korea in 1970's, but it has not been an attractive crop in that time. However, recently it has more attention for the natural food sweet additives. Because stevia have many problems for cultivation especially cultivar, seed germination, fertility, uniformity and glycoside quality, the sport mutation was attempted to in vitro plants for the improvement of some characteristics. The young in vitro plants was nursed on MS medium supplemented with $1mg\;l^{-1}\;GA_3$. Shoots of 10 cm height were irradiated with 0~200 Gy of gamma ray and the every node was separated and inoculated on MS basic medium. The lethality, number and length of shoot, numbers of node and branch were investigated for the evaluation of radiosensitivity. The optimum dose of gamma ray seemed to be around 80 Gy for the sport mutation induction in stevia. The lower node was more sensitive than higher node to radiation.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.29 no.3
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• pp.275-279
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• 1984

To develop a long term storage technique of soybean germplasm, fifty lines of soybean seeds were kept in storage room controlled by air-conditioner and dehumidifier at KAERI. The storage room was kept below 25$^{\circ}C$ of temperature and 60% relative humidity. Germinability of stored seeds was evaluated at every three or six months. On the other hand, the newly harvested seeds of the lines were accerelated aging at 40$^{\circ}C$ and 90% of relative humidity, and compared with non-accerelated seeds. The average germinability at the starting time of storage was 97% but the germinability was decreased to 62% at 42 months after storage in the storage room. The germinability seemed to be affected by seed size and seed coat color. The germinability of small seed lot tended to be higher than that of large seed lot, and the germination response in longer term of storage was greater than those of shorter term of storage. The accerelated aging test for 7 days proved to be a useful technique to pretest germinability of soybean seeds for assaying the relative storage potential.

• Applied Microscopy
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• v.24 no.3
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• pp.67-77
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• 1994

Storage material of endosperm cells digested by various enzymes should be transported to the embryo. At this time, the cellulose of the endosperm cell wall is guessed to be hydrolyzed by the cellulase enabling to transfer the storage material from the endosperm cells to the embryo. Therefore, this study has been carried out to investigate the ultrastructure of endosperm and the localization of the cellase activity on Cannabis sativa L. during germination. Endosperm cells contain a large number of lipid bodies and protein bodies with globoids as the storage material. During gemination they are gradually degenerated, however, the former almost remain until the cells are completely digested. Electron-microscopical reaction products of cellulase on endosperm cells are present. The closer the embryo, the more amount of reaction products on the endosperm cell wall are appeared.

• Natural Product Sciences
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• v.23 no.2
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• pp.125-131
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• 2017

Clitoria ternatea or Commonly known blue pea, is a perennial climber crop native to Asian countries. The current study was aimed to evaluate the antimicrobial activity C. ternatea extract on food borne microorganisms and its antifungal effect on Penicillium expansum. The extract showed significant antimicrobial activity against 3 Gram positive bacteria, 2 Gram negative bacteria and 1 filamentous fungus on disc diffusion assay. The extract also showed good biocidal effect on all Gram positive bacteria tested and P. expansum. However, the kill curve analysis revealed that the fungicidal activity of the extract against P. expansum conidia was depend on the concentration of the extract and the time of exposure of the conidia to the extract. The scanning electron micrograph of the extract treated P. expansum culture showed alterations in the morphology of fungal hyphae. The germination of P. expansum conidia was completely inhibited and conidial development was totally suppressed by the extract, suggesting the possible mode of action of anthocyanin. Besides, the extract also exhibited 5.0-log suppression of microbial growth relative to control in the rice model. The results indicate the potential use of the C. ternatea anthocyanin as food biopreservative.