• Title/Summary/Keyword: forest products

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Isolation and Identification of the Origins Causing the Slime Found in Pulp and Paper Making Processes (제재공장내 슬라임 발생원의 분리와 동정)

  • Oh, Jung-Soo;Jo, Byoung-Muk;Kim, Eun-Hee
    • Journal of the Korean Wood Science and Technology
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    • v.25 no.3
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    • pp.50-57
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    • 1997
  • The presence of slime in paper mills is practically universal. Many researches have been performed for many years to resolve the problem caused by the slime in pulp and paper mill. Many papers have been published to show the bacteria is a major cause of paper mill slime. Now that the recycling of the water has been increased and the regulations of a toxic chemical dosage have become more strengthen, the importance of the control of slime in pulp and paper mill recently has been more recognized. Therefore, to produce quality products at the lowest economic and environmental costs, a through study of the microbial ecology and the indentification of troublesome slime-forming bacteria is a quite necessary. The purpose of this paper is to indentify slime~forming bacteria isolated from the papermaking process. The samples were taken from four parts of making fine paper : machine chest, head box, wire part, white water tank. Machine chest showed the most numbers of bacteria, numbering $2.55{\times}10^7$. The different colony types were taken from the 105 dilution plate. Nine bacteria were identified u sing the Biolog system and the vitek system: 6 gram-negative bacteria, 3 gram-positive bacteria. They are Pseudomonas paucimobilis B., Staphylococcus sp., Acinetobacter calcoaceticus., Pseudomonas cepacia, Actinobaci1lus capsulatus, Acidovorax sp., Flavobacterium sp., and Staphylococcus auricularis in addition to one unidentified sp., Among them. Pseudomonas paucimobillis was found in all places where the samples were taken. And, each parts had the different predominant bacteria in it : Pseudomonas paucimobilis B. in machine chest, Acinetobactor calcoaceticus. in Wire Part and Staphylococcus sp. in head box.

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Evaluation on the Appearance and Gluing Characteristics of Pine Laminated Boards according to Overlaying Materials (소나무 집성판의 표면화장 재료별 외관품질 및 접착성 평가)

  • So, Won-Tek
    • Journal of the Korean Wood Science and Technology
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    • v.35 no.1
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    • pp.27-35
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    • 2007
  • This experiment was carried out to investigate the appearance and surface gluing characteristics of laminated boards overlaied with teak sliced veneer, printing paper, wall paper, cotton cloth, and wool cloth, The overlaying sheets were glued on the laminated boards with polyvinyl acetate emulsion adhesives and the species for laminated boards was red pine. The obtained results are summarized as follows; in case of the teak sliced veneer overlaied boards, the appearance quality was very good and showed the first grade of KS standard. but the delamination rate was 44.0% and 895% for cold water or warm water dipping treatments, respectively, so the wet gluing properties were very bed. In the case of the paper or cloth overlaied boards, the appearance quality was same good and showed the first grade of KS standard, but their delamination rate was 10~20% and 39.3~49.0 for cold water or warm water dipping treatments, respectively, so the wet gluing properties were bed, relatively better than sliced veneer overlaied boards. The present work showed that appearance of laminated boards overlaid with several sheets appeared quite positive in terms of secondary gluing qualities of laminated boards, suggesting that sliced veneer, paper, and cloth would be appropriate for the overlaying materials of laminated boards.

Effects of Electron Beam Treatment on the Characteristics of Pulping and Papermaking of Hemp Bast Fibers (전자빔 처리가 대마 인피섬유의 펄프화 및 초지 특성에 미치는 영향)

  • Bae, Paek-Hyun;Seo, Jae-Hwan;Jung, Jin-Ho;Lee, Jae-Jung;Paik, Ki-Hyun;Kim, Hyoung-Jin
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.44 no.4
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    • pp.51-61
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    • 2012
  • The new alkali pulping process combined with electron beam treatment was applied to utilize hemp bast tissues as a new valuable fibrous resource. Hemp bast tissues have some chemical properties with high lignin contents and holocellulose not to be defiberized by alkali pulping only, compared with the bast tissue of paper mulberry. To make up for the weakness of traditional alkali pulping process, electron beams were directly irradiated into the swelled bast tissue of hemp in NaOH solution and distilled water, and then facilitated the defiberization of hemp bast tissues. The papermaking from hemp bast fibers manufactured by the combination pulping process showed good apparent density, formation structure and air permeability, and had some mechanical properties with lower tensile, tear, burst strength and folding endurance. It is finally concluded that the combination pulping process with electron beam treatment could be suggested a new alternative for non-woody fibers.

Survey of Nematodes in Decideous Bonsai (활엽수 분재의 선충 조사)

  • Choi, Jin Young;Jung, Young Hack;Lee, Dong Woon;Choo, Ho Yul;Park, Chung Gyoo
    • Korean journal of applied entomology
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    • v.57 no.4
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    • pp.303-315
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    • 2018
  • Bonsai is part of export forest products in Korea. Demand for bonsai exports to other countries is growing but the need for quarantine hazards must be eliminated in other to export. Plant parasitic nematode is also an important factor in quarantine. The nematodes were surveyed from bonsai farms in 6 areas of Korea. The surveyed deciduous bonsai plants were Acer palmatum, Zinnia elegans, Ligustrum obtusiflium, Carpinus turcaninowii, and Malus sieboldii. Three plant parasitic nematodes (Hemicyliophora koreana, Rotylenchus blothrotylus and Xiphinema americanum) and three non-parasitic nematodes (Aporclaimellus donghwaens, Egtitus andhricus, and Mesodorylaimus usitatus) were isolated from bonsai. Non-parasitic nematode, Mesodorylaimus usitatus was isolated from all surveyed bonsai trees. Only two species of quarantine nematodes (Hemcylicopora koreana and Xiphinema americanum) were found from bonsai. A. donghwaens and M. usitatus were isolated from root of bonsai tree. However other nematodes were isolated from soil in bonsai trees.

Solvent Extraction of Preservative Components from CCA Treated Wood (CCA 처리재로부터 방부제 유효성분의 용제추출)

  • Kim, Gyu-Hyeok;Kong, Il-Gon;Ra, Jong-Bum;Cho, Jae-Sung;Kim, Jae-Jin
    • Journal of the Korean Wood Science and Technology
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    • v.31 no.4
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    • pp.50-56
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    • 2003
  • This research was performed to select an appropriate agent to extract preservative components from CCA-treated wood, and then to evaluate the effect of reagent concentration, extracting temperature, and extracting time on the removal of chrome, copper, and arsenic from treated wood. Hydrogen peroxide was selected as the best extracting agent when considered extraction yield as well as use and environmental safety. Its extraction yield was dependent on extracting variables (temperature, concentration, and time), and a highly significant interaction existed among variables. It should be possible to optimize extraction by manipulating these extracting variables. The results may suggest that the required temperature conditions for the reasonable removal of CCA components are at least above 40℃ because extracting time is too long at low temperature (20℃). Reagent concentrations for extracting at above 40℃ should be decided by considering the extracting time.

Removing Sapstain of Radiata Pine by Bleaching (표백에 의한 라디에타소나무의 청변 제거)

  • Kim, Gyu-Hyeok;Kim, Hyung-Jun;Ra, Jong-Bum;Kim, Jae-Jin
    • Journal of the Korean Wood Science and Technology
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    • v.31 no.1
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    • pp.46-51
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    • 2003
  • The feasibility of using bleaching treatments for removing fungal stain was evaluated on heavily stained raiadta pine sapwood. Sodium chlorite and sodium hypochlorite appeared to destain fungal discoloration by providing proper treatment conditions (chemical concentration, treatment temperature, and treatment time), while hydrogen peroxide did not remove fungal stain under the bleaching regimes evaluated. The addition of sodium silicate and sodium hydroxide in the hydrogen peroxide solution as a buffer could remove fungal discoloration completely; however, the color of wood surface turned faint green after bleaching, thereby reducing the lightness of bleached samples. The results suggest that hydrogen peroxide bleaching could be a feasible method for removing fungal discoloration of stained radiata pine sapwood, although further research is needed to solve the problem of color change after bleaching. Also, further tests under field conditions are recommended.

Research for the Selection of Agricultural environment in Papua New Guinea (파푸아뉴기니 농업 환경 기초조사)

  • Chang, Kwang Jin;Koo, Hyun Jung;Choi, Jang-Nam
    • Journal of Practical Agriculture & Fisheries Research
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    • v.17 no.1
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    • pp.183-204
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    • 2015
  • Papua New Guinea, birthplace of the South Pacific, is a natural nation which have potential of increasing crops output because it has optimum condition for crop growth as tropical rain forest climate under hot and humid climate. Farming village of Papua New Guinea want to produce crops for create income beyond the self-sufficiency. It needs the technological transfer such as irrigation facilities and understanding of agricultural weather condition for good crops production. In particular, it needs a improvement through pH, EC, ORP for make optimum soil condition and it need the standardization production and farm products what the consumer wants. Internationally technical cooperation is needed for agricultural development of Papua New Guinea and maintenance of international cooperation will help for economic development between the two countries. In particular, basic environment research for agricultural development of Papua New Guinea is expected to play a larger role of technical cooperation of agriculture.

Direct Monitoring of Membrane Fatty Acid Changes and Effects on the Isoleucine/Valine Pathways in an ndgR Deletion Mutant of Streptomyces coelicolor

  • Tae-Rim Choi;Suk Jin Oh;Jeong Hyeon Hwang;Hyun Jin Kim;Nara Shin;Jeonghee Yun;Sang-Ho Lee;Shashi Kant Bhatia;Yung-Hun Yang
    • Journal of Microbiology and Biotechnology
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    • v.33 no.6
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    • pp.724-735
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    • 2023
  • NdgR, a global regulator in soil-dwelling and antibiotic-producing Streptomyces, is known to regulate branched-chain amino acid metabolism by binding to the upstream region of synthetic genes. However, its numerous and complex roles are not yet fully understood. To more fully reveal the function of NdgR, phospholipid fatty acid (PLFA) analysis with gas chromatography-mass spectrometry (GC-MS) was used to assess the effects of an ndgR deletion mutant of Streptomyces coelicolor. The deletion of ndgR was found to decrease the levels of isoleucine- and leucine-related fatty acids but increase those of valine-related fatty acids. Furthermore, the defects in leucine and isoleucine metabolism caused by the deletion impaired the growth of Streptomyces at low temperatures. Supplementation of leucine and isoleucine, however, could complement this defect under cold shock condition. NdgR was thus shown to be involved in the control of branched-chain amino acids and consequently affected the membrane fatty acid composition in Streptomyces. While isoleucine and valine could be synthesized by the same enzymes (IlvB/N, IlvC, IlvD, and IlvE), ndgR deletion did not affect them in the same way. This suggests that NdgR is involved in the upper isoleucine and valine pathways, or that its control over them differs in some respect.

Backward estimation of precipitation from high spatial resolution SAR Sentinel-1 soil moisture: a case study for central South Korea

  • Nguyen, Hoang Hai;Han, Byungjoo;Oh, Yeontaek;Jung, Woosung;Shin, Daeyun
    • Proceedings of the Korea Water Resources Association Conference
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    • 2022.05a
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    • pp.329-329
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    • 2022
  • Accurate characterization of terrestrial precipitation variation from high spatial resolution satellite sensors is beneficial for urban hydrology and microscale agriculture modeling, as well as natural disasters (e.g., urban flooding) early warning. However, the widely-used top-down approach for precipitation retrieval from microwave satellites is limited in several hydrological and agricultural applications due to their coarse spatial resolution. In this research, we aim to apply a novel bottom-up method, the parameterized SM2RAIN, where precipitation can be estimated from soil moisture signals based on an inversion of water balance model, to generate high spatial resolution terrestrial precipitation estimates at 0.01º grid (roughly 1-km) from the C-band SAR Sentinel-1. This product was then tested against a common reanalysis-based precipitation data and a domestic rain gauge network from the Korean Meteorological Administration (KMA) over central South Korea, since a clear difference between climatic types (coasts and mainlands) and land covers (croplands and mixed forests) was reported in this area. The results showed that seasonal precipitation variability strongly affected the SM2RAIN performances, and the product derived from separated parameters (rainy and non-rainy seasons) outperformed that estimated considering the entire year. In addition, the product retrieved over the mainland mixed forest region showed slightly superior performance compared to that over the coastal cropland region, suggesting that the 6-day time resolution of S1 data is suitable for capturing the stable precipitation pattern in mainland mixed forests rather than the highly variable precipitation pattern in coastal croplands. Future studies suggest comparing this product to the traditional top-down products, as well as evaluating their integration for enhancing high spatial resolution precipitation over entire South Korea.

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Social Wasp Diversity and Wasp Nest Removal Trends on Ulleungdo Island, South Korea

  • Jaehee Kim;Il-Kwon Kim;Ohseok Kwon;Moon Bo Choi
    • Proceedings of the National Institute of Ecology of the Republic of Korea
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    • v.4 no.4
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    • pp.146-153
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    • 2023
  • This study aimed to conduct a comprehensive survey of social wasp diversity and its impacts on remote Ulleungdo Island, South Korea. A total of 12 wasp traps were placed across the island, and specimens were collected monthly from May to October. Additional collection was conducted by thoroughly inspecting the areas surrounding the traps. The traps yielded a total of 5,068 individuals, representing two genera and two species. A total of 3,961 Vespa simillima simillima Smith individuals (78.2%) were collected, and 1,107 individuals (21.8%) were identified as Vespula flaviceps flaviceps Smith. Additionally, five individuals of Polistes snelleni de Saussure were collected through sweeping, bringing the total to 5,132 individuals of three genera and three species. It is worth noting that our findings indicate potential misidentifications in the species list of Vespidae found in the literature. Emergency services call centers reported the removal of 60 social wasp nests on Ulleungdo Island between 2018 and 2022, with the highest number of reports occurring from July to September, accounting for 87% of all cases. Dodong-ri and Jeodong-ri, with the highest populations, reported the most incidents, although fortunately, there have been no recent injuries. Past incidents involving the destruction of dried squid products by Vespula species have resulted in significant economic losses, underscoring the need for preventative measures. Furthermore, ongoing surveillance of hornet invasions is essential to safeguard the Jangwon bees being reared on Ulleungdo Island.