• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.42 no.2
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• pp.67-74
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• 2010

This study was carried out to investigate the pulping and papermaking characteristics of lotus (Nelumbo nucifera G.) leafstalk for the development of high performance paper. Anatomical and chemical properties of the lotus leafstalk were analyzed. The pulping and papermaking properties of the lotus leafstalk by conventional alkali and sulfomethylated pulping processes were also evaluated. The length and width of fibers were 0.06-3.32 mm (av. 1.23 mm) and 3.47-25.6 ${\mu}m$ (av. 20.7 ${\mu}m$), respectively. The length and width of vessel elements were 0.07-0.78 mm (av. 0.20 mm) and 14.1-330.0 ${\mu}m$ (av. 54.13 ${\mu}m$), respectively. The fiber length/fiber width ratio was 60.20. The extractives (cold water, hot water, 1% NaOH and ethanol-benzene) and lignin content of lotus leafstalk were higher than those of plant bast fiber. The contents of holocellulose, lignin, and ash were 73.8%, 24.3%, and 4.3%, respectively. The pulp yields based on pulping methods were sulfomethylated pulping av. 52%, and alkaline pulping av. 42%. The conventional alkaline pulping shows better pulp and sheet properties than the sulfomethylated pulping which was modified pulping processes. But the sulfomethylated pulping shows higher brightness than alkali pulping. In the consequence of FE-SEM observation, lotus leafstalk pulp consists of various kinds of thin walled fibers which have large amount of small pits.

• Journal of the Korea Institute of Building Construction
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• v.15 no.4
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• pp.383-389
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• 2015

The objective of this study is to develop mixture proportioning approach of crack controlled lightweight foamed concrete without using high-pressure steam curing processes, as an alternative to autoclaved lightweight concrete blocks (class 0.6 specified in KS). To control thermal cracks owing to hydration heat of cementitious materials, 30% ground granulated blast-furnace slag (GGBS) was used as a partial replacement of ordinary portland cement (OPC). Furthermore, polyvinyl alcohol (PVA) and polyamid (PA) fibers were added to improve the crack resistance of foamed concrete. The use of 30% GGBS reduced the peak value of hydration production rate measured from isothermal tests by 28% and the peak temperature of foamed concrete measured from semi-adiabatic hydration tests by 9%. Considering the compressive strength development, internal void structure, and flexural strength of the lightweight foamed concrete, the optimum addition amount of PVA or PA fibers could be recommended to be $0.6kg/m^3$, although PA fiber slightly preferred to PVA fiber in enhancing the flexural strength of foamed concrete.

• Korean Journal of Plant Resources
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• v.36 no.4
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• pp.290-298
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• 2023

Several members of the genus Broussonetia are woody plants with high-quality cellulose fibers and are used to make a traditional type of Korean paper known as Hanji. Three of these species, Broussonetia kazinoki, Broussonetia monoica, and Broussonetia papyrifera, are found in the Korean Peninsula. Because it is challenging to distinguish different Broussonetia species based on morphology alone, we have developed a set of insertion/deletion (InDel) markers for genetic identification of these species. From twenty-two Broussonetia samples collected throughout Korea, we selected six for next-generation sequencing analysis. InDel marker candidates were identified by comparing this sequence information with the B. kazinoki chloroplast genome sequence. The marker candidates were used to screen the genomes of the twenty-two Broussonetia plants, and five useful chloroplast-based InDel markers were identified. Detailed genotyping using these five markers showed that the twenty-two plants of the genus Broussonetia could be clustered into five groups, verifying that the markers developed here can be used for breeding, identification, and analysis of species in the genus Broussonetia.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.4 no.1
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• pp.57-66
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• 2001

The floating islands have been constructed for the water quality improvement and the biodiversity conservation in an disturbed aquatic ecosystem. We made floating islands consisted of a special float and substrates of coconut fibers implanted with four emergent macrophytes such as Phragmites australis, Zizania latifolia, Iris pseudoacorus, Typha angustifolia. Vegetation structure and plant growth were compared between on the floating islands and on ground in order to select suitable plants for the construction of floating islands. Emergent-macrophytic vegetation on the floating islands showed lower coverages and higher plant biodiversity due to natural introduction of various hydrophytes and hygrophytes. Shoot density was increased on floating islands except for Zizania latifolia. From the point of coverage and density of plants, Phragmites australis and Iris pseudoacorus were suitable for floating islands. Total biomass of emergent macrophytes was decreased on the floating islands. The belowground/aboveground biomass ratio of floating islands was higher than that of the ground. Out of planted macrophytes, Iris pseudoacorus with a high belowground/aboveground biomass ratio could be evaluated a suitable plant for the floating islands because a plenty of its root is profitable to adapt with the nutrient-limited environment of floating islands.

• Korean Journal of Medicinal Crop Science
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• v.9 no.3
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• pp.192-197
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• 2001

This study was carried out to select proper SPME fiber for volatile component analysis in Zanthoxylum schinifolium and Z. piperitum. PDMS, PDMS/DVB and CAR/PDMS were better for single standard absorption analysis. PDMS and PDMS/DVB showed similar results in comparison between direct injection and the mixture of 24 single standards as well as the mixture of 10 single standards. PDMS and PDMS/DVB were not different each other in absorption patterns between direct injection and headspace SPME regardless of split ratio of GC injection port. However PDMS/DVB rather than PDMS was effective in absorbing the sesquiterpenes within 30-40 minutes as using the SDE extracts from Z. schinifolium and Z. piperitum.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.32-32
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• 2022

Abaca (Musa textilis L. Nee) is a native Musa species from the Philippines known for its natural fiber. Abaca fiber a.k.a. Manila hemp extracted from its pseudostems is considered one of the strongest fibers in the world. This is used for commodities such as ropes, papers, and money bills. Abaca is vulnerable to pests and diseases such as the Abaca Bunchy Top Disease (ABTD) caused by Abaca Bunchy Top Virus (ABTV) and Banana Bunchy Top Virus (BBTV). Inosa, one of the varieties of abaca utilized in the Philippines, is highly susceptible to ABTD. In contrast, Pacol (Musa balbisiana L.), a close relative of abaca, is highly resistant to the same disease. Here, we report the sequencing and de novo genome assembly of both abaca var. Inosa and banana var. Pacol. A total of ~16 Gb and ~21 Gb raw reads for Inosa and Pacol, respectively, were generated using Pacbio Hifi sequencing method and assembled with Hifiasm. High-quality de novo assemblies of both Musa species with 99% recovered as per BUSCO analysis were obtained. The assembled Inosa genome has a total length of ~654 Mb and N50 of 7 Mb while Pacol has a total length of 527 Mb and N50 of 3 Mb which are close to their estimated genome size of ~638 Mb and ~503 Mb, respectively. The information that can be derived from the de novo assembled genomes would provide a solid foundation for further research in disease resistance and fiber quality improvement in abaca.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.9 no.2
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• pp.23-32
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• 2006

Total suspended solids (TSS), five-day biochemical oxygen demand ($BOD_5$), total nitrogen (T-N), and total phosphorous (T-P) concentrations around and under a floating island were examined from October 2002 to September 2003. The island was installed in July 2002 on the surface of an agricultural irrigation reservoir located in the southern part of the Korean Peninsula. It was composed of six polyethylene panels. Each panel was 2 m (length) ${\times}$ 1 m (width) ${\times}$ 0.02 m (thick) and had about thirty-two holes each with a diameter of eight centimeters, through which plant roots grew down into the water. Coconut fibers of nine-centimeters in height were placed on the panel, which sustained plants rhizomes and roots. Both the fibers and the panel were raped with polyethylene wire mashes. About thirty irises (Iris pseudoacorus) were planted into the fibers of each panel. The concentrations of TSS, $BOD_5$, T-N and T-P below the island during the iris-growing season averaged 9.70, 2.59, 3.61 and 0.14 mg/L, respectively and those around it averaged 9.99, 2.83, 4.07 and 0.16 mg/L, respectively. The average concentrations of TSS, $BOD_5$, T-N and T-P below it during the iris non-growing season were 8.68, 2.37, 3.25 and 0.14 mg/L, respectively and those near it were 8.76, 2.43, 3.34 and 0.15 mg/L, respectively. At a significance level of ${\alpha}$=0.05, $BOD_5$, T-N and T-P concentrations under the island during the iris-growing season were significantly low when compared with those around it except TSS. No differences in TSS, $BOD_5$, T-N and T-P concentrations between around and near it were found at a significance level of ${\alpha}$=0.05 during the iris non-growing season. The removal of $BOD_5$, T-N, and T-P during the growing season were significantly high when compared with those during the non-growing season. TSS abatement of the floating island was very low during both the growing and non-growing seasons. The island's reductions of $BOD_5$, T-N and T-P were good during the growing season, especially T-N and T-P, which have been considered as primary pollutant sources causing the water quality degradation of reservoirs. The removal of T-N and T-P was primarily attributed to the absorption of nitrogen and phosphorous by the irises during the growing season.

• Journal of the Korea Organic Resources Recycling Association
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• v.31 no.1
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• pp.57-68
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• 2023

In this study, coffee waste was recycled into nitrogen-doped porous carbon fibers as an active material for high-energy EDLC (Electric Double Layer Capacitors). The coffee waste was mixed with polyvinylpyrrolidone and dissolved into dimethylformamide. The mixture was then electrospun to fabricate coffee waste-derived nanofibers (Bare-CWNF), and carbonization process was followed under a nitrogen atmosphere at 900℃. Similar to Bare-CWNF, the as-synthesized carbonized coffee waste-derived nanofibers (Carbonized-CWNF) maintained its fibrous form while preserving the composition of nitrogen. The electrochemical performance was analyzed for carbonized coffee waste (Carbonized-CW)-, carbonized PAN-derived nanofibers (Carbonized-PNF)-, and Carbonized-CWNF-based electrodes in the operating voltage window of -1.0-0.0V, Among the electrodes, Carbonized-CWNF-based electrodes exhibited the highest specific capacitance of 123.8F g^-1 at 1A g^-1 owing to presence of nitrogen and porous structure. As a result, nitrogen-contained porous carbon fibers synthesized from coffee waste showed excellent electrochemical performance as electrodes for high-energy EDLC. The experimental designed in this study successfully demonstrated the recycling of the coffee waste, one of the plant-based biomass that causes the environmental pollution into high-energy materials, also, attaining the ecofriendliness.

• Journal of the Korea institute for structural maintenance and inspection
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• v.28 no.3
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• pp.47-58
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• 2024

This study were conduced experimentally to analyze the heat-generating performance, flexural strength, and microstructure of conductive mortar mixed with micro steel fiber and multi-wall carbon nanotube (MWCNT). In the conductive mortar heat-generating performance and flexural strength tests, the mixing concentration of MWCNT was selected as 0.0wt%, 0.5wt%, and 1.0wt% relative to the weight of cement, and micro steel fibers were mixed at 2.0vol% relative to the volume. The performance experiments were conducted with various applied voltages (DC 10V, 30V, 60V) and different electrode spacings (40 mm, 120 mm) as parameters, and the flexural strength was measured at the curing age of 28 days and compared and analyzed with the normal mortar. Furthermore, the surface shape and microstructure of conductive mortar were analyzed using a field emission scanning electron microscope (FE-SEM). The results showed that the heat-generating performance improved as the mixing concentration of MWCNT and the applied voltage increased, and it further improved as the electrode spacing became narrower. However, even if the mixing concentration of MWCNT was added up to 1.0 wt%, the heat-generating performance was not significantly improved. As a result of the flexural strength test, the average flexural strength of all specimens except the PM specimen and the MWCNT mixed specimens was 4.5 MPa or more, showing high flexural strength due to the incorporation of micro steel fibers. Through FE-SEM image analysis, Through FE-SEM image analysis, it was confirmed that a conductive network was formed between micro steel fibers and MWCNT particles in the cement matrix.

• Parasites, Hosts and Diseases
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• v.51 no.5
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• pp.537-544
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• 2013

The present study was performed to observe histopathological changes in tissues of Bithynia siamensis goniomphalos (Gastropoda, Bithyniidae) incubated in crude extract solutions of camellia (Camellia oleifera) seed and mangosteen (Garcinia mangostana) pericarp, and furthermore to estimate the molluscicidal effects of 2 plant substances. Substantial numbers of bithyniid snails were incubated in various concentrations of 2 plant solution for 24 hr. As the positive control, snails incubated in various concentrations of niclosamide, a chemical molluscicide, were used. The histopathological findings were observed in sectioned snail specimens of each experimental and control groups. The results showed that both camellia and mangosteen extracts had molluscicidal effects at 24 hr with 50% lethal concentration ($LC_{50}$) at concentrations of 0.003 and 0.002 g/ml, respectively, while niclosamide had $LC_{50}$ at concentrations 0.599 ppm. B. siamensis goniomphalos snail tissues (foot, gill, and digestive system) showed disruption of columnar muscle fibers of the foot, reduction of the length and number of gill cilia, numerous mucous vacuoles, and irregularly shaped of epithelial cells. Irregular apical and calciferous cells, dilatation of the digestive gland tubule, and large hemolymphatic spaces, and irregular apical surfaces, detachment of cilia, and enlargement of lysosomal vacuoles of epidermis were also shown in all groups. By the present study, it is confirmed that 2 plants, camellia and mangosteen, are keeping some substance having molluscicidal effects, and histopathological findings obtained in this study will provide some clues in further studies on their action mechanisms to use them as natural molluscicides.