103 results on '"Sung Phil Mun"'
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2. Potential of Hardwood Kraft Lignin as a Bio-based Dye for Cotton Fabrics
- Author
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Ji Sun Mun and Sung Phil Mun
- Subjects
hardwood kraft lignin ,bio-based dye ,cotton ,dyeing ,mordanting ,cationization ,Biotechnology ,TP248.13-248.65 - Abstract
The dyeing characteristics of hardwood kraft lignin (KL) were investigated on cotton fabrics, assessing its potential as a sustainable and environmentally friendly dye. Dyeability was evaluated by varying the KL concentrations, temperature, and time. An aqueous solution of Na2CO3 (1.0%) as the dye bath and a fabric-to-liquor ratio of 1:50 were used. Cationizing effects were studied using (3-chloro-2-hydroxypropyl) trimethylammonium chloride (CHPTAC), and the mordanting effects of various mordants were also evaluated. Post-mordanting was performed with FeSO4, FeCl2, Fe-lactate (Fe-lac), MgSO4, CuCl2, CuSO4, and Al2(SO4)3. A mordant concentration of 1 mM o.w.f. (0.5 mM for Al2(SO4)3), with a liquor ratio of 1:30, at 60 °C for 30 min were employed. Suitable dyeing conditions were 2.0% o.w.b., 90 °C, and 90 min, resulting in a brownish color of the cotton fabric. The fabrics exhibited a range of light brown to light grayish brown colors and showed lighter colors than the untreated fabrics when mordanted with MgSO4 and Al2(SO4)3. The color difference (ΔE) between cationized and uncationized cotton fabrics was 3.48. From the colorfastness assessment, KL-dyed cotton fabric showed good rubbing and washing fastness for staining, but poor light and washing fastness for fading.
- Published
- 2023
3. Proanthocyanidin-rich Extract from Pinus radiata Bark: Mild-Alkaline Extraction and Characterization
- Author
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Sung Phil Mun
- Subjects
pinus radiata bark ,proanthocyanidin (pa)-rich extracts ,mild-alkaline extraction ,pa content ,antioxidant activity ,Biotechnology ,TP248.13-248.65 - Abstract
This study assessed the efficacy of mild-alkaline extraction from P. radiata bark in obtaining proanthocyanidin (PA)-rich extracts. When the bark was treated with three types of bases—Na2CO3, NaHCO3, and NaOH—at varying concentrations, the extract yields increased with higher concentrations. When the pH of the extracts exceeded 7, the PA content and antioxidant activity were remarkably reduced. This result suggests that the pH holds a greater effect in the alkaline extraction of the bark rather than the type of base used. Among the bases used, NaHCO3 was selected and the extraction conditions of pine bark were examined at a concentration where the pH of the extract did not exceed 7. The extraction time during mild-alkaline extraction using 0.2% NaHCO3 was reduced compared to water-only extraction at the same temperature. Moreover, the extract yields were over 10% higher than those of water extraction, and the dried extracts exhibited good solubility in water. The mild-alkaline extracts were characterized using FT-IR and 13C NMR spectroscopic techniques, and acidic alcoholysis. Analyses of the spectra of the mild-alkaline extracts showed similarities to that of pure PA and hot water extract. This result indicated that PA in the bark was not significantly affected during mild-alkaline extraction.
- Published
- 2023
4. Thermal Characterization of Kraft Lignin Prepared from Mixed Hardwoods
- Author
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Justin Alfred Pe III, Ji Sun Mun, and Sung Phil Mun
- Subjects
kraft lignin (kl) ,acacia ,mixed hardwoods ,thermal analysis ,pyrolysis-gc/ms ,syringyl (s) ,guaiacyl (g) ,Biotechnology ,TP248.13-248.65 - Abstract
Thermal characterization of kraft lignin (KL) prepared from mixed hardwoods was conducted to determine their thermal and thermo-oxidative stability, glass transition temperature (Tg), pyrolysis products composition, and syringyl/guaiacyl ratio. Two milled wood lignins (MWLs) from acacia (MWL-aca) and mixed hardwoods (MWL-mhw), the same hardwood species employed in the production of KL, were also characterized for comparison with KL. Thermogravimetric analysis (TGA) indicated that KL had higher thermal and thermo-oxidative stability than MWLs. Based on differential scanning calorimetry (DSC), the Tg of KL was 63.2 °C, while MWLs gave similar values near 165 °C. The syringyl (S), guaiacyl (G), p-hydroxyphenyl (H) composition of KL acquired from pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) at 675 °C was 48:44:8 (S/G ratio 1.07), while MWL-aca and MWL-mhw were 31:60:9 and 46:48:6, respectively.
- Published
- 2022
5. Characterization of Kraft Lignin Prepared from Mixed Hardwoods by 2D HMQC and 31P NMR Analyses
- Author
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Ji Sun Mun, Justin Alfred Pe III, and Sung Phil Mun
- Subjects
kraft lignin ,mixed hardwood ,hmqc ,31p nmr ,hydroxyl content ,Biotechnology ,TP248.13-248.65 - Abstract
This study was conducted to determine the lignin substructures, hydroxyl (phenolic + aliphatic) contents, and carboxyl contents in kraft lignin (KL) prepared from mixed hardwoods by using 2D Heteronuclear Multiple Quantum Coherence Nuclear Magnetic Resonance (HMQC NMR) and 31P NMR techniques. Based on 2D HMQC NMR analysis of KL, stilbene and vanillin substructures were present in the aromatic region, while trace amounts of β-O-4 and β-β moieties were detected in the oxygenated aliphatic region. The total hydroxyl content calculated from 31P NMR was 5.24 mmol/g KL. The aliphatic hydroxyl content was 1.04 mmol/g KL, and phenolic hydroxyl content was 4.20 mmol/g KL. Of the phenolic hydroxyl groups, the contribution of syringyl (S) and guaiacyl (G) was 1.02 and 0.97 mmol/g KL, respectively. The S/G molar ratio of KL calculated from 31P NMR was 1.05. The carboxyl content was 0.44 mmol/g KL.
- Published
- 2022
6. Hydroxypropylation of Polyphenol-Rich Alkaline Extracts from Pinus radiata Bark and Their Physicochemical Properties
- Author
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Sung Phil Mun
- Subjects
Pinus radiata bark ,alkaline extract ,propylene oxide (PO) ,hydroxypropylation ,molar substitution (MS) ,PEG#400 ,Organic chemistry ,QD241-441 - Abstract
Pinus radiata bark is a rich source of polyphenols, which are mainly composed of proanthocyanidins. This study aimed to utilize P. radiata bark as a polyol source for bio-foam production in the future. Polyphenol-rich alkaline extracts (AEs) from P. radiata bark were prepared by mild alkaline treatment and then derivatized with propylene oxide (PO). Hydroxypropylated alkaline extracts (HAEs) with varying molar substitutions (MS 0.4–8.0) were characterized by FT-IR, NMR, GPC, TGA, and DSC. The hydroxyl value and solubility in commercial polyols were also determined. The molecular weights of the acetylated HAEs (Ac-HAEs) were found to be 4000 to 4900 Da. Analyses of FT-IR of HAEs and 1H NMR of Ac-HAEs indicated that the aromatic hydroxyl groups were hydroxypropylated and showed an increase in aliphatic hydroxyl group content. The glass transition temperature (Tg) of AE and HAEs were 58 to 60 °C, showing little difference. The hydroxyl value increased as the hydroxypropylation proceeded. Although salts were produced upon neutralization after hydroxypropylation, HAEs still showed suitable solubility in polyether and polyester polyols; HAEs dissolved well in polyether polyol, PEG#400, and solubility reached about 50% (w/w). This indicated that neutralized HAEs could be directly applied to bio-foam production even without removing salts.
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- 2022
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7. Chemical Characterization of Kraft Lignin Prepared from Mixed Hardwoods
- Author
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Ji-Sun Mun, Justin Alfred Pe, and Sung-Phil Mun
- Subjects
kraft lignin ,acacia ,mixed hardwood ,milled wood lignin ,structural analysis ,Organic chemistry ,QD241-441 - Abstract
Chemical characterization of kraft lignin (KL) from mixed hardwoods (Acacia spp. from Vietnam and mixed hardwoods (mainly Quercus spp.) from Korea) was conducted for its future applications. To compare the structural changes that occurred in KL, two milled wood lignins (MWLs) were prepared from the same hardwood samples used in the production of KL. Elemental analysis showed that the MWL from acacia (MWL-aca) and mixed hardwood (MWL-mhw) had almost similar carbon content, methoxyl content, and C9 formula. KL had high carbon content but low oxygen and methoxyl contents compared to MWLs. The C9 formula of KL was determined to be C9H7.29O2.26N0.07S0.12(OCH3)1.24. The Mw of KL and MWLs was about 3000 Da and 12,000–13,000 Da, respectively. The structural features of KL and MWLs were investigated by Fourier transform infrared spectroscopy (FT-IR) and nuclear magnetic resonance spectrometry (1H, 13C NMR). The analyses indicated that KL underwent severe structural modifications, such as γ-carbon cleavage, demethylation, and polycondensation reactions during kraft pulping, which resulted in increased aromatic content and decreased aliphatic content. The main linkages in lignin, β-O-4 moieties, were hardly detected in the analysis as these linkages were extensively cleaved by nucleophilic attack of SH- and OH- during pulping.
- Published
- 2021
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8. Preliminary investigation of the UV LED photodegradation of methylene blue using TiO2–carbonized medium-density fiberboard
- Author
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Justin Alfred Pe III, Sung Phil Mun, and Jae Pil Kim
- Subjects
Environmental Engineering ,Bioengineering ,Waste Management and Disposal - Abstract
This preliminary study aimed to realize the potential use of titanium dioxide–carbonized medium-density fiberboard (TiO2–cMDF) as a biomaterial for dye wastewater treatment. TiO2–cMDF, which was prepared by carbonizing MDF treated with titanium tetraisopropoxide in isopropyl alcohol, was investigated for adsorption and then photodegradation of methylene blue (MB) under UV-A (390 nm, 19 W) and UV-C (280 nm, 12 W) light emitting diodes (LEDs). After two full cycles of adsorption, four successive cycles of photodegradation were conducted under UV-A LED. For every adsorption or photodegradation cycle, TiO2–cMDF practically removed MB. Both adsorption and photodegradation followed pseudo-first-order kinetics. The rate constants for adsorption decreased by half. The rate constants for photodegradation were similar. This finding suggests that UV-A LED is a robust and steady source of UV light. Photodegradation under UV-C LED was also performed. However, due to its high-energy output, the UV-C LED module overheated even though a cooling fan was present. Although the results indicate a slow photodegradation under UV LEDs, because of the limited number of specimens, increasing the number of specimens and UV LED modules will improve its performance.
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- 2022
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9. Alkaline Hydrogen Peroxide Delignification of Three Lignocellulosic Biomass under Atmospheric Pressure.
- Author
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Ji Sun Mun and Sung Phil Mun
- Subjects
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LIGNOCELLULOSE , *DELIGNIFICATION , *CRYPTOMERIA japonica , *ATMOSPHERIC pressure , *BIOMASS , *CONSTRUCTION materials , *HYDROGEN peroxide - Abstract
The study's goal was to investigate the delignification characteristics using alkaline hydrogen peroxide (AHP) under atmospheric pressure, intending it as a pre-treatment method for transforming low-value lignocellulosic biomass into high-performance structural materials. The lignocellulosic biomass used in this study were Japanese cedar (Cryptomeria japonica), Hyun aspen (Populus alba x glandulosa), and bamboo (Phyllostachys pubescens), which are underutilized and low-value lignocellulosic biomass in Korea. The delignification conditions used were pH 11, liquor ratio 12.5, H2O2 (3 to 10%), temperature (25 to 100 °C), and time (1 to 24 h). Japanese cedar exhibited <30% delignification even under the most severe conditions. In contrast, Hyun aspen achieved more than double that level of delignification. However, reaching over 60% delignification was challenging. Bamboo was easily delignified, reaching approximately 80% delignification using similar conditions performed in Japanese cedar and Hyun aspen. These differences observed in AHP delignification among three species were likely to be primarily due to the structural differences and proportion of condensed units in lignin. Consequently, for Hyun aspen and bamboo, the AHP delignification process under atmospheric pressure was considered to be feasible as a pre-treatment method for high-performance structural materials. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
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10. Potential of Hardwood Kraft Lignin as a Bio-based Dye for Cotton Fabrics.
- Author
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Ji Sun Mun and Sung Phil Mun
- Subjects
- *
NATURAL dyes & dyeing , *COTTON textiles , *COTTON , *LIGNINS , *HARDWOODS , *DYES & dyeing , *IRON chlorides - Abstract
The dyeing characteristics of hardwood kraft lignin (KL) were investigated on cotton fabrics, assessing its potential as a sustainable and environmentally friendly dye. Dyeability was evaluated by varying the KL concentrations, temperature, and time. An aqueous solution of Na2CO3 (1.0%) as the dye bath and a fabric-to-liquor ratio of 1:50 were used. Cationizing effects were studied using (3-chloro-2-hydroxypropyl) trimethylammonium chloride (CHPTAC), and the mordanting effects of various mordants were also evaluated. Post-mordanting was performed with FeSO4, FeCl2, Fe-lactate (Fe-lac), MgSO4, CuCl2, CuSO4, and Al2(SO4)3. A mordant concentration of 1 mM o.w.f. (0.5 mM for Al2(SO4)3), with a liquor ratio of 1:30, at 60 °C for 30 min were employed. Suitable dyeing conditions were 2.0% o.w.b., 90 °C, and 90 min, resulting in a brownish color of the cotton fabric. The fabrics exhibited a range of light brown to light grayish brown colors and showed lighter colors than the untreated fabrics when mordanted with MgSO4 and Al2(SO4)3. The color difference (E) between cationized and uncationized cotton fabrics was 3.48. From the colorfastness assessment, KL-dyed cotton fabric showed good rubbing and washing fastness for staining, but poor light and washing fastness for fading. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
11. Proanthocyanidin-rich Extract from Pinus radiata Bark: Mild-Alkaline Extraction and Characterization.
- Author
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Sung Phil Mun
- Subjects
- *
PINUS radiata , *HOT water , *EXTRACTS , *ALCOHOLYSIS , *SPECTRUM analysis - Abstract
This study assessed the efficacy of mild-alkaline extraction from P. radiata bark in obtaining proanthocyanidin (PA)-rich extracts. When the bark was treated with three types of bases--Na2CO3, NaHCO3, and NaOH--at varying concentrations, the extract yields increased with higher concentrations. When the pH of the extracts exceeded 7, the PA content and antioxidant activity were remarkably reduced. This result suggests that the pH holds a greater effect in the alkaline extraction of the bark rather than the type of base used. Among the bases used, NaHCO3 was selected and the extraction conditions of pine bark were examined at a concentration where the pH of the extract did not exceed 7. The extraction time during mild-alkaline extraction using 0.2% NaHCO3 was reduced compared to water-only extraction at the same temperature. Moreover, the extract yields were over 10% higher than those of water extraction, and the dried extracts exhibited good solubility in water. The mild-alkaline extracts were characterized using FT-IR and 13C NMR spectroscopic techniques, and acidic alcoholysis. Analyses of the spectra of the mildalkaline extracts showed similarities to that of pure PA and hot water extract. This result indicated that PA in the bark was not significantly affected during mild-alkaline extraction. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
12. Black Color Expression of Silk and Cotton Fabrics Using Neutral Extract from Pinus radiata Bark and Various Iron Mordants
- Author
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Ji Sun Mun, Hwan Chul Kim, and Sung Phil Mun
- Subjects
Polymers and Plastics ,General Chemical Engineering ,General Chemistry - Published
- 2022
- Full Text
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13. TiO2-carbonized medium-density fiberboard for the photodegradation of methylene blue
- Author
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Sung Phil Mun, Min Lee, and Justin Alfred Pe
- Subjects
Aqueous solution ,Forestry ,Isopropyl alcohol ,Plant Science ,Fiberboard ,Industrial and Manufacturing Engineering ,chemistry.chemical_compound ,Adsorption ,Reaction rate constant ,chemistry ,visual_art ,Photocatalysis ,visual_art.visual_art_medium ,General Materials Science ,Photodegradation ,Methylene blue ,Nuclear chemistry - Abstract
TiO2-carbonized medium-density fiberboard (TiO2-cMDF), prepared by carbonization of MDF treated with 50% (v/v) titanium tetraisopropoxide (Ti-tip) in isopropyl alcohol (IPA) as a precursor, was investigated for adsorption and photodegradation in aqueous methylene blue (MB) solution under UV-C (254 nm) irradiation. After full adsorption of MB, four successive cycles of photodegradation were conducted. After the second cycle, the TiO2-cMDF was rinsed with water, dried, and subjected to photodegradation again. For every photodegradation cycle, the TiO2-cMDF practically removed MB. The photodegradation results of the second (unrinsed) and third (rinsed) cycle were similar, however, the result of the fourth (rinsed) cycle was lower than the third cycle. The rate constant of adsorption was 3.3 × 10–3/h and followed pseudo-first-order kinetics. The rate constant of photodegradation decreased from 11.0 × 10–3/h (first cycle) to 5.9 × 10–3/h (fourth cycle) and likewise followed pseudo-first-order kinetics. A reduction in Ti content on the surface of TiO2-cMDF was observed after photodegradation based on scanning electron microscope-energy dispersive X-ray spectrometer (SEM–EDS) analysis; nonetheless, photodegradation of MB was still accomplished. Although TiO2-cMDF in aqueous system exhibited slow photodegradation, it is due to the limited number of TiO2-cMDF slabs. The number of slabs must be increased to improve the photocatalytic performance.
- Published
- 2021
- Full Text
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14. Potential of Neutral Extract Prepared by Treating Pinus radiata Bark with NaHCO3 as a Dyestuff
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Ji Sun MUN, Hwan Chul KIM, and Sung Phil MUN
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Materials Science (miscellaneous) ,Industrial and Manufacturing Engineering - Published
- 2021
- Full Text
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15. Conditions for the Extraction of Polyphenols from Radiata Pine (Pinus radiata) Bark for Bio-Foam Preparation
- Author
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Sung Phil Mun, Su Hyeon Jeong, and Min Lee
- Subjects
Chromatography ,biology ,Chemistry ,Materials Science (miscellaneous) ,Pinus radiata ,Radiata ,Extraction (chemistry) ,biology.organism_classification ,Industrial and Manufacturing Engineering ,Solvent ,Proanthocyanidin ,Polyphenol ,visual_art ,visual_art.visual_art_medium ,Bark ,Solubility - Abstract
The use of polyphenol extracts from radiata pine (Pinus radiata) bark as raw materials for bio-foams was investigated along with the optimal NaOH extraction conditions. The targeted yield of alkaline extracts was 60%, and the targeted pH was 11 to 12. The radiata pine bark was composed of 70% of a 1% NaOH extract, which contained mainly polyphenols, such as proanthocyanidin (PA). As the particle size of the bark decreased, the yield of the 1% NaOH extracts increased from 57 to 87%. A range of NaOH concentrations, liquor ratios, and extraction times were explored to establish an economic polyphenol extraction method. More than 60% of the alkaline extract was extracted, and the pH of the extract was approximately 12 when the optimum extraction conditions were employed, i.e., a liquor to bark ratio of 5:1, a NaOH dosage of 17 to 18% based on the bark weight, and a 1 h extraction time. Following neutralization of the alkaline extract, structural analysis indicated severe structural changes in the PA during the alkaline extraction. Because the alkaline extract was barely soluble in the solvent used for the structural analyses, it is assumed that chemical modification is required to increase the solubility of the alkaline extract for the production of bio-foams.
- Published
- 2020
- Full Text
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16. Chemical Characterization of Neutral Extracts Prepared by Treating Pinus radiata Bark with Sodium Bicarbonate
- Author
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Ji Sun MUN, Hwan Chul KIM, and Sung Phil MUN
- Subjects
Materials Science (miscellaneous) ,Industrial and Manufacturing Engineering - Published
- 2020
- Full Text
- View/download PDF
17. One-step preparation of visible-light-responsive TiO2 with carbonized medium-density fiberboard for toluene degradation
- Author
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Sang-Bum Park, Sung Phil Mun, and Min Lee
- Subjects
Materials science ,Carbonization ,chemistry.chemical_element ,Forestry ,One-Step ,Plant Science ,Fiberboard ,Toluene ,Decomposition ,Industrial and Manufacturing Engineering ,chemistry.chemical_compound ,chemistry ,Chemical engineering ,Rutile ,visual_art ,visual_art.visual_art_medium ,General Materials Science ,Cobalt ,Visible spectrum - Abstract
A visible-light-responsive TiO2 with carbonized medium-density fiberboard (c-MDF) was prepared by a one-step preparation method, and its application as an interior building material for decomposition of harmful aromatic volatile organic compounds was evaluated by investigating its toluene decomposition performance. Titanium tetraisopropoxide, cobalt nitrate, and iron nitrate were used as precursor materials for synthesizing metal-doped TiO2, which was then treated on MDF followed by carbonization. After carbonization at 800 °C for 2 h, the crystal structure of metal-doped TiO2 was similar to that of rutile TiO2. Further, a toluene decomposition test was conducted using a modified 20-L chamber system with a commercial fluorescent lamp as the light source. The results revealed that 0.1 mol% metal-doped TiO2/c-MDF completely decomposed toluene in 15 h under visible-light irradiation.
- Published
- 2020
- Full Text
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18. Chemical Characterization of Kraft Lignin Prepared from Mixed Hardwoods
- Author
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Justin Alfred Pe, Ji-Sun Mun, and Sung Phil Mun
- Subjects
Pharmaceutical Science ,chemistry.chemical_element ,Organic chemistry ,Article ,Analytical Chemistry ,chemistry.chemical_compound ,mixed hardwood ,QD241-441 ,Drug Discovery ,milled wood lignin ,Hardwood ,Lignin ,structural analysis ,Physical and Theoretical Chemistry ,Fourier transform infrared spectroscopy ,acacia ,Demethylation ,kraft lignin ,Carbon-13 NMR ,chemistry ,Kraft process ,Chemistry (miscellaneous) ,Elemental analysis ,Molecular Medicine ,Carbon ,Nuclear chemistry - Abstract
Chemical characterization of kraft lignin (KL) from mixed hardwoods (Acacia spp. from Vietnam and mixed hardwoods (mainly Quercus spp.) from Korea) was conducted for its future applications. To compare the structural changes that occurred in KL, two milled wood lignins (MWLs) were prepared from the same hardwood samples used in the production of KL. Elemental analysis showed that the MWL from acacia (MWL-aca) and mixed hardwood (MWL-mhw) had almost similar carbon content, methoxyl content, and C9 formula. KL had high carbon content but low oxygen and methoxyl contents compared to MWLs. The C9 formula of KL was determined to be C9H7.29O2.26N0.07S0.12(OCH3)1.24. The Mw of KL and MWLs was about 3000 Da and 12,000–13,000 Da, respectively. The structural features of KL and MWLs were investigated by Fourier transform infrared spectroscopy (FT-IR) and nuclear magnetic resonance spectrometry (1H, 13C NMR). The analyses indicated that KL underwent severe structural modifications, such as γ-carbon cleavage, demethylation, and polycondensation reactions during kraft pulping, which resulted in increased aromatic content and decreased aliphatic content. The main linkages in lignin, β-O-4 moieties, were hardly detected in the analysis as these linkages were extensively cleaved by nucleophilic attack of SH- and OH- during pulping.
- Published
- 2021
19. Fe–Doped TiO2–Carbonized Medium–Density Fiberboard for Photodegradation of Methylene Blue under Visible Light
- Author
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Sung Phil Mun, Min Lee, and Justin Alfred Pe
- Subjects
Technology ,Fe–doped TiO2 ,Materials science ,Kinetics ,Analytical chemistry ,Fiberboard ,Article ,law.invention ,chemistry.chemical_compound ,Adsorption ,Reaction rate constant ,law ,General Materials Science ,Photodegradation ,visible light ,Microscopy ,QC120-168.85 ,QH201-278.5 ,Engineering (General). Civil engineering (General) ,medium-density fiberboard ,TK1-9971 ,chemistry ,Descriptive and experimental mechanics ,visual_art ,visual_art.visual_art_medium ,methylene blue ,Electrical engineering. Electronics. Nuclear engineering ,TA1-2040 ,photodegradation ,Methylene blue ,Visible spectrum ,Light-emitting diode - Abstract
Fe–doped titanium dioxide–carbonized medium–density fiberboard (Fe/TiO2–cMDF) was evaluated for the photodegradation of methylene blue (MB) under a Blue (450 nm) light emitting diode (LED) module (6 W) and commercial LED (450 nm + 570 nm) bulbs (8 W, 12 W). Adsorption under daylight/dark conditions (three cycles each) and photodegradation (five cycles) were separately conducted. Photodegradation under Blue LED followed pseudo-second-order kinetics while photodegradation under commercial LED bulbs followed pseudo-first-order kinetics. Photodegradation rate constants were corrected by subtracting the adsorption rate constant except on the Blue LED experiment due to their difference in kinetics. For 8 W LED, the rate constants remained consistent at ~11.0 × 10−3/h. For 12 W LED, the rate constant for the first cycle was found to have the fastest photodegradation performance at 41.4 × 10−3/h. After the first cycle, the rate constants for the second to fifth cycle remained consistent at ~28.5 × 10−3/h. The energy supplied by Blue LED or commercial LEDs was sufficient for the bandgap energy requirement of Fe/TiO2–cMDF at 2.60 eV. Consequently, Fe/TiO2–cMDF was considered as a potential wood-based composite for the continuous treatment of dye wastewater under visible light.
- Published
- 2021
20. Synthesis of TiO2 via modified sol-gel method and its use in carbonized medium-density fiberboard for toluene decomposition
- Author
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Min Lee, Sung Phil Mun, and Sang-Bum Park
- Subjects
Environmental Engineering ,Aqueous solution ,Materials science ,Ethanol ,Carbonization ,Bioengineering ,Fiberboard ,Decomposition ,Toluene ,chemistry.chemical_compound ,chemistry ,visual_art ,visual_art.visual_art_medium ,Photocatalysis ,Waste Management and Disposal ,Nuclear chemistry ,Sol-gel - Abstract
A solution-type TiO2-based photocatalyst for the decomposition of volatile organic compounds was synthesized using a modified sol-gel method under either alcohol (ethanol or isopropanol) or aqueous conditions. Anatase-type TiO2 was successfully synthesized with additional hydrothermal treatment using either type of medium. However, the aqueous condition for TiO2 synthesis was more convenient for the formation of anatase-type TiO2. Based on X-ray diffraction analysis data, the optimal hydrothermal treatment temperature was 80 °C for anatase-type TiO2 formation; at temperatures below 80 °C or above 90 °C, mostly rutile-type TiO2 was formed. The synthesized anatase-type TiO2 solution was applied to the surface of carbonized medium-density fiberboard (c-MDF). The anatase-type TiO2 on c-MDF showed good maintenance of toluene decomposition performance even after repeated use for 14 weeks.
- Published
- 2019
- Full Text
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21. One-step preparation of TiO2–carbonized medium-density fiberboard for volatile organic compound photodegradation
- Author
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Sung Phil Mun, Min Lee, and Sang-Bum Park
- Subjects
chemistry.chemical_classification ,Anatase ,Environmental Engineering ,Carbonization ,Formaldehyde ,Bioengineering ,Toluene ,Catalysis ,chemistry.chemical_compound ,chemistry ,Photocatalysis ,Volatile organic compound ,Photodegradation ,Waste Management and Disposal ,Nuclear chemistry - Abstract
Photocatalytic carbonized medium density fiberboard (MDF) was prepared by one-step carbonization with titanium tetraisopropoxide (Ti-tip) as a TiO2 precursor. Anatase TiO2 was formed at carbonizing temperatures of 600 to 800 °C. However, at > 900 °C, most crystalline TiO2 was rutile. Ti-tip-treated carbonized MDF (c-MDF) showed outstanding formaldehyde reduction performance with complete removal of formaldehyde from the chamber in 1 to 3 days. However, with non Ti-tip-treated c-MDF, formaldehyde remained after 20 days. No toluene was detected after 3 h on 50% Ti-tip-treated c-MDF, while toluene was continuously detected with other samples (10% and 5% Ti-tip-treated c-MDF, and untreated c-MDF). After 9 h ultraviolet exposure, toluene was completely reduced on 10% and 50% Ti-tip-treated c-MDF; reduction was only 20% on untreated c-MDF. In addition, c-MDF/TiO2 prepared at 800 and 900 °C had significantly higher photocatalytic performances compared to those obtained at lower carbonization temperatures. Based on the results, the combination of 10% Ti-tip treatment and carbonizing at 800 °C provided the optimum photodegradation capacity for formaldehyde and toluene.
- Published
- 2019
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22. CHARACTERISATION OF LIGNIN EXTRACTED FROM SIX MANGROVE SPECIES GROWN IN BANGLADESH
- Author
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Sung Phil Mun, M. Aminul Ahsan, Inars, Bcsir, Dr. Qudrat-i-Khuda Road, Dhaka , Bangladesh, A. Al-Maruf, and M. Sarwar Jahan
- Subjects
chemistry.chemical_compound ,chemistry ,Organic Chemistry ,Botany ,Materials Chemistry ,Lignin ,Mangrove - Published
- 2019
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23. Thermal Characterization of Kraft Lignin Prepared from Mixed Hardwoods.
- Author
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Pe III, Justin Alfred, Ji Sun Mun, and Sung Phil Mun
- Subjects
LIGNINS ,GLASS transition temperature ,DIFFERENTIAL scanning calorimetry ,PYROLYSIS gas chromatography ,WOOD - Abstract
Thermal characterization of kraft lignin (KL) prepared from mixed hardwoods was conducted to determine their thermal and thermooxidative stability, glass transition temperature (T
g ), pyrolysis products composition, and syringyl/guaiacyl ratio. Two milled wood lignins (MWLs) from acacia (MWL-aca) and mixed hardwoods (MWL-mhw), the same hardwood species employed in the production of KL, were also characterized for comparison with KL. Thermogravimetric analysis (TGA) indicated that KL had higher thermal and thermo-oxidative stability than MWLs. Based on differential scanning calorimetry (DSC), the Tg of KL was 63.2 °C, while MWLs gave similar values near 165 °C. The syringyl (S), guaiacyl (G), p-hydroxyphenyl (H) composition of KL acquired from pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) at 675 °C was 48:44:8 (S/G ratio 1.07), while MWL-aca and MWL-mhw were 31:60:9 and 46:48:6, respectively. [ABSTRACT FROM AUTHOR]- Published
- 2023
- Full Text
- View/download PDF
24. Characterization of Kraft Lignin Prepared from Mixed Hardwoods by 2D HMQC and 31P NMR Analyses.
- Author
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Ji Sun Mun, Justin Alfred Pe III, and Sung Phil Mun
- Subjects
HARDWOODS ,NUCLEAR magnetic resonance ,QUANTUM coherence ,LIGNIN structure ,STILBENE derivatives ,HYDROXYL group ,LIGNINS - Abstract
This study was conducted to determine the lignin substructures, hydroxyl (phenolic + aliphatic) contents, and carboxyl contents in kraft lignin (KL) prepared from mixed hardwoods by using 2D Heteronuclear Multiple Quantum Coherence Nuclear Magnetic Resonance (HMQC NMR) and 31P NMR techniques. Based on 2D HMQC NMR analysis of KL, stilbene and vanillin substructures were present in the aromatic region, while trace amounts of β-O-4 and β-β moieties were detected in the oxygenated aliphatic region. The total hydroxyl content calculated from 31P NMR was 5.24 mmol/g KL. The aliphatic hydroxyl content was 1.04 mmol/g KL, and phenolic hydroxyl content was 4.20 mmol/g KL. Of the phenolic hydroxyl groups, the contribution of syringyl (S) and guaiacyl (G) was 1.02 and 0.97 mmol/g KL, respectively. The S/G molar ratio of KL calculated from 31P NMR was 1.05. The carboxyl content was 0.44 mmol/g KL. [ABSTRACT FROM AUTHOR]
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- 2022
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25. Essential oil from Korean Chamaecyparis obtusa leaf ameliorates respiratory activity in Sprague-Dawley rats and exhibits protection from NF-κB-induced inflammation in WI38 fibroblast cells
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Jeong Doo Heo, Sung Phil Mun, Sang Joon Lee, Venu Venkatarame Gowda Saralamma, Eun Hee Kim, Ho Jeong Lee, Sang Eun Ha, Seong Min Kim, Suchismita Raha, and Gon Sup Kim
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0106 biological sciences ,Lipopolysaccharides ,Male ,030213 general clinical medicine ,Nitric Oxide Synthase Type II ,Pharmacology ,01 natural sciences ,law.invention ,Rats, Sprague-Dawley ,0302 clinical medicine ,law ,Chamaecyparis ,terpene ,medicine.diagnostic_test ,biology ,Chemistry ,Respiration ,NF-kappa B ,General Medicine ,Articles ,Nitric oxide synthase ,medicine.anatomical_structure ,medicine.symptom ,Cell Survival ,Chamaecyparis obtusa ,Inflammation ,Protective Agents ,Models, Biological ,essential oil ,gas chromatography/mass spectrometry ,Cell Line ,03 medical and health sciences ,Western blot ,Administration, Inhalation ,Genetics ,medicine ,Oils, Volatile ,Animals ,Humans ,Fibroblast ,Hinoki Cypress ,Essential oil ,WI38 fibroblast cells ,Terpenes ,Fibroblasts ,biology.organism_classification ,Plant Leaves ,Pulmonary Alveoli ,Cell culture ,Cyclooxygenase 2 ,biology.protein ,010606 plant biology & botany - Abstract
To date, Korean hinoki cypress (Chamaecyparis obtusa), has been widely used for household and commercial purposes. Although the medicinal efficacy of hinoki cypress essential oil has been observed, that of the essential oil-derived terpenes, which exhibit a mechanism that acts against lung inflammation, remains to be fully elucidated. The present study investigated the anti-inflammatory effect of hinoki cypress leaf extracted essential oil on lipopolysaccharide (LPS)-stimulated WI38 fibroblast cells by inhibiting the nuclear factor κ-light-chain-enhancer of activated B cells (NF-κB) pathway, which exhibited lung tissue protection through the olfactory administration of essential oil in Sprague-Dawley rats. GC/MS analysis derived 24 terpenes from the essential oil. The morphological observations revealed that, upon LPS stimulation of WI38 fibroblast cells, inflammation was induced, whereas the condition of the cells reverted to normal in the essential oil extract pre-treated group. The results of western blot analysis revealed the inhibition of inducible nitric oxide synthase, activation of cyclooxygnase-2, and the degradation of cytosolic p65 and inhibitor of NF-κB-α in the LPS-stimulated group. Additionally, confocal imaging of nuclei revealed the translocation of phosphorylated p65, which was recovered in the cytosol in the phytoncide essential oil pre-treated group. Histopathological observation revealed that the alveolar capacity was enhanced in the essential oil olfactory administered rat group, compared with that in the normal rat group. These findings suggest that terpenes in essential oil from the Chamaecyparis obtusa leaf have therapeutic potential against respiratory inflammation-related disease.
- Published
- 2018
26. Preliminary Investigation of the UV LED Photodegradation of Methylene Blue Using TiO2-carbonized Medium-density Fiberboard.
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Alfred Pe III, Justin, Sung Phil Mun, and Jae Pil Kim
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- *
FIBERBOARD , *PHOTODEGRADATION , *LIGHT emitting diodes , *TITANIUM dioxide nanoparticles , *WASTEWATER treatment - Abstract
This preliminary study aimed to realize the potential use of titanium dioxide-carbonized medium-density fiberboard (TiO2-cMDF) as a biomaterial for dye wastewater treatment. TiO2-cMDF, which was prepared by carbonizing MDF treated with titanium tetraisopropoxide in isopropyl alcohol, was investigated for adsorption and then photodegradation of methylene blue (MB) under UV-A (390 nm, 19 W) and UV-C (280 nm, 12 W) light emitting diodes (LEDs). After two full cycles of adsorption, four successive cycles of photodegradation were conducted under UV-A LED. For every adsorption or photodegradation cycle, TiO2-cMDF practically removed MB. Both adsorption and photodegradation followed pseudo-first-order kinetics. The rate constants for adsorption decreased by half. The rate constants for photodegradation were similar. This finding suggests that UV-A LED is a robust and steady source of UV light. Photodegradation under UV-C LED was also performed. However, due to its high-energy output, the UV-C LED module overheated even though a cooling fan was present. Although the results indicate a slow photodegradation under UV LEDs, because of the limited number of specimens, increasing the number of specimens and UV LED modules will improve its performance. [ABSTRACT FROM AUTHOR]
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- 2022
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27. Effect of Proanthocyanidin-rich Extracts from Pinus radiata Bark on Termite Feeding Deterrence
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Darrel D. Nicholas and Sung Phil Mun
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Proanthocyanidin ,biology ,Materials Science (miscellaneous) ,Pinus radiata ,visual_art ,Deterrence (psychology) ,Botany ,visual_art.visual_art_medium ,Bark ,biology.organism_classification ,Industrial and Manufacturing Engineering - Published
- 2017
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28. The role of immobilized rennet on carbon cloth in flavor development during ripening of Gouda cheese
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Sung Phil Mun, Sei-Eok Yun, and Su-Hyeon Jeong
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Immobilized enzyme ,Chemistry ,Cheese Flavor ,010401 analytical chemistry ,food and beverages ,Ripening ,04 agricultural and veterinary sciences ,040401 food science ,01 natural sciences ,Applied Microbiology and Biotechnology ,Article ,0104 chemical sciences ,0404 agricultural biotechnology ,Gouda cheese ,food ,Rennet ,Chymosin ,Food science ,food.cheese ,Lactic acid fermentation ,Flavor ,Food Science ,Biotechnology - Abstract
Rennet-free Gouda (RFG) cheese was prepared to investigate the influence of rennet on the non-volatile and volatile profiles of cheese and was characterized by HPLC and GC/MS analyses. Chymosin, a major protease in rennet, was immobilized onto oxidized and chemically modified carbon cloth. The chymosin immobilization efficiency was 60.4%, and the milk-clotting activity used as an index of the stability of the immobilized chymosin decreased by around 20% in 2 weeks. However, the activity was maintained at 70–80% from 2 weeks to 32 weeks and was more stable than that of chymosin solution alone. Non-volatile (organic acids) and volatile profiles of the RFG cheese and rennet-containing normal Gouda cheese were not significantly different during ripening with a few exceptions. Therefore, it can be concluded that cheese flavor is developed by lactic acid fermentation, irrespective of the presence of rennet.
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- 2016
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29. Pinus radiata bark extract induces caspase-independent apoptosis-like cell death in MCF-7 human breast cancer cells
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Sung Phil Mun, Young-Woong Choi, Thamizhiniyan Venkatesan, and Young-Kyoon Kim
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0301 basic medicine ,Programmed cell death ,Cell Survival ,Health, Toxicology and Mutagenesis ,Apoptosis ,Breast Neoplasms ,Biology ,Toxicology ,03 medical and health sciences ,Cell Line, Tumor ,Autophagy ,Humans ,Cytotoxic T cell ,Viability assay ,Inner mitochondrial membrane ,Plant Extracts ,Endoplasmic reticulum ,Cell Biology ,Pinus ,Mitochondria ,Cell biology ,Oxidative Stress ,030104 developmental biology ,Biochemistry ,Caspases ,Cancer cell ,MCF-7 Cells ,Plant Bark ,Unfolded protein response ,Female ,Lysosomes ,Reactive Oxygen Species - Abstract
In the present study, we investigated the anticancer activity of Pinus radiata bark extract (PRE) against MCF-7 human breast cancer cells. First, we observed that PRE induces potent cytotoxic effects in MCF-7 cells. The cell death had features of cytoplasmic vacuolation, plasma membrane permeabilization, chromatin condensation, phosphatidylserine externalization, absence of executioner caspase activation, insensitivity to z-VAD-fmk (caspase inhibitor), increased accumulation of autophagic markers, and lysosomal membrane permeabilization (LMP). Both the inhibition of early stage autophagy flux and lysosomal cathepsins did not improve cell viability. The antioxidant, n-acetylcysteine, and the iron chelator, deferoxamine, failed to restore the lysosomal integrity indicating that PRE-induced LMP is independent of oxidative stress. This was corroborated with the absence of enhanced ROS production in PRE-treated cells. Chelation of both intracellular calcium and zinc promotes PRE-induced LMP. Geranylgeranylacetone, an inducer of Hsp70 expression, also had no significant protective effect on PRE-induced LMP. Moreover, we found that PRE induces endoplasmic reticulum (ER) stress and mitochondrial membrane depolarization in MCF-7 cells. The ER stress inhibitor, 4-PBA, did not restore the mitochondrial membrane integrity, whereas cathepsin inhibitors demonstrated significant protective effects. Collectively, our results suggest that PRE induces an autophagic block, LMP, ER stress, and mitochondrial dysfunction in MCF-7 cells. However, further studies are clearly warranted to explore the exact mechanism behind the anticancer activity of PRE in MCF-7 human breast cancer cells.
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- 2016
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30. Change in Chemical Compositions of Leachate and Medium Density Fiberboard from a Laboratory-scale Simulated Landfill
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Lynn Prewitt, Min Lee, and Sung Phil Mun
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0106 biological sciences ,Materials science ,020209 energy ,Materials Science (miscellaneous) ,02 engineering and technology ,Laboratory scale ,Pulp and paper industry ,01 natural sciences ,Industrial and Manufacturing Engineering ,chemistry.chemical_compound ,chemistry ,Elemental analysis ,010608 biotechnology ,0202 electrical engineering, electronic engineering, information engineering ,Lignin ,Soil treatment ,sense organs ,Fiber ,Leachate ,Composite material ,Medium density fiberboard ,Chemical composition - Abstract
The change in chemical compositions of leachate and medium density fiberboard (MDF) from a labo-ratory-scale simulated landfill which constructed in a plastic container containing alternating layers of soil and MDF was investigated to evaluate decomposing of MDF in soil. Four treatments were conducted: 1) MDFin soil, 2) MDF only, 3) cured UF resin in soil, and 4) soil only. Molecular weight (MW) distribution ofcompounds in leachate from soil only treatment did not change over time. In UF resin in soil treatment, the MW distribution shifted to a lower MW distribution over time, while the peak shifted to the left indicated changing to higher MW distribution in leachate from treatment 1 and 2 contained MDF. Higher percentnitrogen in leachate was observed in MDF containing treatments due to the UF resin in the MDF. The percentcarbon slightly increased in MDF only while that greatly decreased in MDF in soil treatment maybe due to bacterial activity. The percent of extractable materials from the MDF decreased greatly on day 35 compare to day 0, and subsequently did not change much on day 77. In contrast, percent holocellulose and lignin did not change much over time. No structural change of the wood fiber in MDF occurs during the study. Water-solublematerials from MDF in soil contributed the change in chemical composition of leachate.Keywords : simulated landfill, leachate, medium density fiberboard, urea-formaldehyde resin, chemical analysis, elemental analysis
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- 2016
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31. Environmental Assessments of Leachate from Medium Density Fiberboard in a Simulated Landfill
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Sung Phil Mun, Min Lee, and Lynn Prewitt
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Biochemical oxygen demand ,Materials science ,Waste management ,Materials Science (miscellaneous) ,Chemical oxygen demand ,Formaldehyde ,Pulp and paper industry ,complex mixtures ,Industrial and Manufacturing Engineering ,chemistry.chemical_compound ,chemistry ,Soil treatment ,Leachate ,Leaching (agriculture) ,Medium density fiberboard ,Wastewater quality indicators - Abstract
This study investigated environmental assessments of leachate containing formaldehyde from medium density fiberboard (MDF) disposed in laboratory-scale simulated landfills. Environmental impact assessment of leachate was conducted by measuring formaldehyde, toxicity, biochemical oxygen demand (BOD), chemical oxygen demand (COD), bacterial enumeration, and pH. Amount of formaldehyde in leachate from MDF in soil decreased to the level of soil only treatment by 28 days, and toxicity decreased as the amount of formaldehyde decreased. BOD and COD levels in leachate from the treatments containing MDF exceeded permissible discharge levels of BOD or COD throughout the experimental period. The pH levels of all treatment were within permissible discharge range except on day 0. Fewer bacteria were observed in leachate from MDF in soil treatment than other treatments (MDF only, cured UF resin in soil, and soil only). Consequently, the leachate from disposal of MDF in soil detrimentally affect on environment. However, soil buffered formaldehyde leaching and pH on leachate in this study. Waste MDF may be required the pre-water soaking treatment for leaching formaldehyde to reclaim on land.
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- 2015
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32. Preparation of Fe-cored carbon nanomaterials from mountain pine beetle-killed pine wood
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Sung Phil Mun, Jilei Zhang, and Zhiyong Cai
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Pinus contorta ,Materials science ,biology ,Carbonization ,Mechanical Engineering ,chemistry.chemical_element ,Condensed Matter Physics ,biology.organism_classification ,Carbide ,chemistry.chemical_compound ,chemistry ,Nitrate ,Mechanics of Materials ,Pine wood ,Environmental chemistry ,General Materials Science ,Composite material ,Carbon ,Carbon nanomaterials ,Mountain pine beetle - Abstract
The mountain pine beetle-killed lodgepole pine ( Pinus contorta ) wood treated with iron (III) nitrate solution was used for the preparation of Fe-cored carbon nanomaterials (Fe-CNs) under various carbonization temperatures. The carbonization yield of Fe-treated sample (5% as Fe) was always 1–3% higher (after ash compensation) than that of the non-treated samples heated at the same condition. The lowest carbonization temperature required to produce Fe-CNs was 700 °C. The carbon shell was composed of 30–40 well-aligned layers of graphitic carbon nanostructure. The iron captured by graphitic layers was assumed to be iron carbides and/or α-Fe and γ-Fe. This study indicates that at least 700 °C of carbonization temperature is needed for the production of Fe-CNs and the mountain pine beetle-killed pine wood can be a carbon source for the production of Fe-CNs.
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- 2015
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33. Proanthocyanidin-rich Pinus radiata bark extract inhibits mast cell-mediated anaphylaxis-like reactions
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Chang Ho Song, Sung Phil Mun, and Yun Ho Choi
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0301 basic medicine ,Hypersensitivity, Immediate ,Male ,Allergy ,chemistry.chemical_element ,Calcium ,Pharmacology ,Immunoglobulin E ,03 medical and health sciences ,chemistry.chemical_compound ,Mice ,0302 clinical medicine ,In vivo ,medicine ,Animals ,Proanthocyanidins ,Mast Cells ,Anaphylaxis ,biology ,Plant Extracts ,Mast cell ,medicine.disease ,Pinus ,In vitro ,Rats ,030104 developmental biology ,medicine.anatomical_structure ,chemistry ,biology.protein ,Intracellular ,Histamine ,030215 immunology - Abstract
Mast cells play a critical role in the effector phase of immediate hypersensitivity and allergic reactions. Pinus radiata bark extract exerts multiple biological effects and exhibits immunomodulatory and antioxidant properties. However, its role in mast cell-mediated anaphylactic reactions has not been thoroughly investigated. In this study, we examined the effects of proanthocyanidin-rich water extract (PAWE) isolated from P. radiata bark on compound 48/80-induced or antidinitrophenyl (DNP) immunoglobulin E (IgE)-mediated anaphylaxis-like reactions in vivo. In addition, we evaluated the mechanism underlying the inhibitory effect of PAWE on mast cell activation, with a specific focus on histamine release, using rat peritoneal mast cells. PAWE attenuated compound 48/80-induced or anti-DNP IgE-mediated passive cutaneous anaphylaxis-like reactions in mice, and it inhibited histamine release triggered by compound 48/80, ionophore A23187, or anti-DNP IgE in rat peritoneal mast cells in vitro. Moreover, PAWE suppressed compound 48/80-elicited calcium uptake in a concentration-dependent manner and promoted a transient increase in intracellular cyclic adenosine-3',5'-monophosphate levels. Together, these results suggest that proanthocyanidin-rich P. radiata bark extract effectively inhibits anaphylaxis-like reactions.
- Published
- 2017
34. Formaldehyde Release from Medium Density Fiberboard in Simulated Landfills for Recycling
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Sung Phil Mun, Lynn Prewitt, and Min Lee
- Subjects
chemistry.chemical_compound ,Materials science ,chemistry ,Waste management ,Materials Science (miscellaneous) ,Formaldehyde ,Leachate ,Medium density fiberboard ,Industrial and Manufacturing Engineering - Published
- 2014
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35. Efficacy and Reusability of Commercial Adsorbent for Isolation of Proanthocyanidins from Hot Water Extract of Pinus radiata Bark
- Author
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Sung Phil Mun
- Subjects
Ethanol ,Materials science ,Chromatography ,Materials Science (miscellaneous) ,Industrial and Manufacturing Engineering ,Hydrophobe ,chemistry.chemical_compound ,Adsorption ,chemistry ,Proanthocyanidin ,Sephadex ,Desorption ,visual_art ,visual_art.visual_art_medium ,Taxifolin ,Bark - Abstract
This study was carried out to investigate the feasibility and usefulness of a commercial synthetic adsorbent, Diaion HP 20, for the isolation of proanthocyanidins (PAs) from hot water extract (HWE) prepared from Pinus radiata bark. Most ultraviolet (UV) absorbing materials in HWE were adsorbed onto Diaion HP 20 and easily recovered by simple ethanol (EtOH) washing. More than 50% of the UV absorbing materials were adsorbed within 20 minutes, and the adsorption equilibrium was reached within 3 h. The recovered materials from Diaion HP 20 were mostly composed of PAs, but some monomeric flavonoids such as taxifolin and unidentified hydrophobic materials were also adsorbed. The impurities such as carbohydrates and inorganic materials contained in HWE were mostly removed by Diaion HP 20. The adsorption ability of the UV absorbing materials onto Diaion HP 20 was almost the same as the first cycle even after 14 times of repeating cycles of adsorption and desorption. The radical scavenging ability of the recovered materials from the ad-sorbentwas slightly higher than that of thepure PAs prepared by Sephadex LH 20 from the same HWE.
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- 2014
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36. Fe-catalyzed thermal conversion of sodium lignosulfonate to graphene
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Sung Phil Mun, Zhiyong Cai, and Jilei Zhang
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Materials science ,Graphene ,Scanning electron microscope ,Sodium lignosulfonate ,Mechanical Engineering ,Inorganic chemistry ,Nanoparticle ,Thermal treatment ,Condensed Matter Physics ,law.invention ,Catalysis ,chemistry.chemical_compound ,symbols.namesake ,chemistry ,Mechanics of Materials ,Transmission electron microscopy ,law ,symbols ,General Materials Science ,Raman spectroscopy - Abstract
Sodium lignosulfonate (LS) from sulfite pulping processing was used as a carbon source to synthesize graphene. LS was mixed with Fe nanoparticles (FeNPs) as a catalyst and thermally treated at 1000 °C for 1 h. The Raman spectrum and X-ray diffraction pattern suggested that graphene sheets were formed in LS thermally treated with FeNPs (Fe-HTLS). Scanning electron microscopy image of Fe-HTLS showed clusters of thin graphene sheets appearing in the form of nanoflowers. High-resolution transmission electron microscopy and electron reflection images provided further evidence of the formation of graphene in LS thermally treated in the presence of Fe catalyst.
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- 2013
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37. Thermal Conversion of Pine Wood Char to Carbon Nanomaterials in the Presence of Iron Nanoparticles
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Fumiya Watanabe, Umesh P Agarwal, Zhiyong Cai, Jilei Zhang, and Sung Phil Mun
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Materials science ,chemistry.chemical_element ,Nanoparticle ,Forestry ,Plant Science ,Nanomaterials ,Catalysis ,symbols.namesake ,chemistry ,Chemical engineering ,Transmission electron microscopy ,symbols ,General Materials Science ,Graphite ,Char ,Composite material ,Raman spectroscopy ,Carbon - Abstract
Southern yellow pine (Pinus taeda) wood char powder was thermally treated at 1,000°C in the presence of a 25-nm-size Fe nanoparticle catalyst. The thermally treated carbon materials were analyzed by Raman spectroscopy and high-resolution transmission electron microscopy. Well-aligned graphitic carbon structures with 15 to 17 layers on average were observed. These graphitic carbon structures were similar to those of graphite with an average interplanar distance of 0.34 nm. The Raman spectra results showed that the full-width half-maximum values of Raman G and D bands, and the peak intensity ratio, ID″/IG, of thermally treated pine char after an acid purification treatment were 69 cm−1, 126 cm−1, and 0.16, respectively.
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- 2012
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38. Immobilization of a Mediator onto Carbon Cloth Electrode and Employment of the Modified Electrode to an Electroenzymatic Bioreactor
- Author
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Eun Seon Jeong, Muthuswamy Sathishkumar, Sei Eok Yun, Sung Phil Mun, Su Hyeon Jeong, Song Yie Park, and Rasu Jayabalan
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Working electrode ,DTNB ,Dithionitrobenzoic Acid ,Dehydrogenase ,Electrochemistry ,Applied Microbiology and Biotechnology ,Electron Transport ,Bioreactors ,Alpha ketoglutarate ,Glutamate Dehydrogenase ,Multienzyme Complexes ,Sodium Glutamate ,NADH, NADPH Oxidoreductases ,Enzyme Inhibitors ,Electrodes ,Enzyme Assays ,Aqueous solution ,Chromatography ,Chemistry ,Electrochemical Techniques ,General Medicine ,NAD ,Carbon ,Electrode ,Ketoglutaric Acids ,NAD+ kinase ,Oxidation-Reduction ,Biotechnology ,Nuclear chemistry - Abstract
5,5'-Dithiobis(2-nitrobenzoic acid) (DTNB) was selected as an electron transfer mediator and was covalently immobilized onto high porosity carbon cloth to employ as a working electrode in an electrochemical NAD(+)-regeneration process, which was coupled to an enzymatic reaction. The voltammetric behavior of DTNB attached to carbon cloth resembled that of DTNB in buffered aqueous solution, and the electrocatalytic anodic current grew continuously upon addition of NADH at different concentrations, indicating that DTNB is immobilized to carbon cloth effectively and the immobilized DTNB is active as a soluble one. The bioelectrocatalytic NAD+ regeneration was coupled to the conversion of L-glutamate into alpha-ketoglutarate by L-glutamate dehydrogenase within the same microreactor. The conversion at 3 mM monosodium glutamate was very rapid, up to 12 h, to result in 90%, and then slow up to 24 h, showing 94%, followed by slight decrease. Low conversion was shown when substrate concentration exceeding 4 mM was tested, suggesting that L-glutamate dehydrogenase is inhibited by alpha-ketoglutarate. However, our electrochemical NAD+ regeneration procedure looks advantageous over the enzymatic procedure using NADH oxidase, from the viewpoint of reaction time to completion.
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- 2012
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39. Effect ofPinus radiataBark Polyphenols on Phenol Liquefaction of Cellulose in the Presence ofp-Toluene Sulfonic Acid Catalyst
- Author
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Sung Phil Mun, Jeong Phil Jang, and Moon G. Kim
- Subjects
chemistry.chemical_classification ,Materials science ,Liquefaction ,Forestry ,Sulfuric acid ,Plant Science ,Sulfonic acid ,complex mixtures ,Catalysis ,chemistry.chemical_compound ,chemistry ,Polyphenol ,visual_art ,visual_art.visual_art_medium ,Organic chemistry ,Phenol ,General Materials Science ,Bark ,Cellulose - Abstract
The influence of Pinus radiata bark polyphenol components in the phenol liquefaction of P. radiata bark was investigated using p-toluene sulfonic acid (PTSA) and sulfuric acid (SA) as acid catalysts. A series of the phenol liquefaction reactions were carried out using mixtures of pure cellulose with increasing amounts of hot-water extract (HWE) of P. radiata bark—the polyphenol-rich component of bark. The yields of liquefied product reactions and combined phenol amounts in them were determined, and the liquefaction residues were also analyzed for determination of acid-soluble and insoluble polyphenols and residual cellulose fractions. The yield of cellulose liquefaction decreased linearly with increasing amounts of HWE with the effect being more pronounced for SA than for PTSA. The combined phenol amount increased with liquefaction yield increases for both SA and PTSA catalysts, but at liquefaction yield levels above 83 percent, more phenol was combined for SA catalyst than for PTSA catalyst. The...
- Published
- 2012
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40. Effect of Pinus radiate bark extracts with different molecular weight distributions on cell growth of NIH/3T3 fibroblasts and dendrite retraction of B16 melanoma cells
- Author
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Sung Phil Mun and Chang Sub Ku
- Subjects
Biomaterials ,Melanin ,chemistry.chemical_compound ,Non-competitive inhibition ,Biochemistry ,Proanthocyanidin ,chemistry ,Cell growth ,Tyrosinase ,Arbutin ,Viability assay ,Ascorbic acid - Abstract
Hot water extract (HWE) of Pinus radiata bark was separated into monomeric polyphenol (MPP), oligomeric proanthocyanidin (OPA), and polymeric proanthocyanidin (PPA) fractions by monitored chromatography using a Sephadex LH 20 column and an UV detector at 250 nm. The effects of these fractions on NIH/3T3 fibroblasts and B16 melanoma cells were examined by evaluating cell viability, melanogenesis (melanin content), morphological changes, and tyrosinase inhibitory activity. The polyphenolic fractions had a proliferation effect on fibroblasts, with cell growth increasing significantly (P < 0.01) even at the high concentration of 1250 μg/ml. At 125 μg/ml, HWE, MPP, and OPA had no effect on melanogenesis, whereas PPA significantly upregulated melanogenesis (P < 0.05). Melanogenesis was significantly upregulated in melanoma cells treated with these fractions at the high concentration of 600 μg/ml (P < 0.01). B16 melanoma cells cultured with the proanthocyanidin (PA)-rich fractions (HWE, OPA, and PPA) showed marked dendrite retraction, leading to significant morphological transformation. OPA in particular showed colored adhesion on the surface of melanoma cells. All four fractions significantly inhibited mushroom tyrosinase activity when compared to arbutin and ascorbic acid 2-glucoside (P < 0.05). The tyrosinase inhibitory activity of OPA and PPA did not differ significantly (P = 0.11), indicating that the inhibitory effects had a low correlation with molecular weight distribution. The inhibition kinetics of PPA determined using a Lineweaver-Burk plot indicated that PPA is a noncompetitive inhibitor of l-3,4-dihydroxyphenylalanine oxidation by mushroom tyrosinase.
- Published
- 2011
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41. Antifungal Activity of Organic Extracts from Juniperus virginiana Heartwood against Wood Decay Fungi
- Author
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Sung Phil Mun and Lynn Prewitt
- Subjects
Chloroform ,Chromatography ,biology ,Ethyl acetate ,Forestry ,Plant Science ,Sesquiterpene ,biology.organism_classification ,Juniperus virginiana ,Hexane ,chemistry.chemical_compound ,chemistry ,Gloeophyllum trabeum ,Organic chemistry ,General Materials Science ,Methanol ,Trametes versicolor - Abstract
Easter red cedar (Juniperus virginiana) is a valuable source of heartwood extractives that provide decay resistance against termites and wood decay fungi. This study sought to determine the antifungal activity of heartwood extracts obtained using solvents with increasing polarity (hexane, chloroform, ethyl acetate, and methanol) against two wood decay fungi. The heartwood was extracted with methanol, and the methanol extract was sequentially extracted with hexane, chloroform, and ethyl acetate. The yield of the methanol extractives was 5.26 percent based on dry wood and the percentages of the hexane, chloroform, and ethyl acetate soluble fractions from the methanol extract were 46.4, 8.3, and 28.7 percent, respectively. Hexane and chloroform soluble fractions showed a high inhibitory effect on the growth of the wood decay fungi Trametes versicolor and Gloeophyllum trabeum. Gas chromatography–mass spectrometry analysis identified skeletons of sesquiterpenes and sesquiterpene alcohols in both extracts and t...
- Published
- 2011
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42. Effects of Water Extraction Temperatures on the Yield, Molecular Weight, and Antioxidant Activity of Proanthocyanidins Extracted from Pinus radiata Bark
- Author
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Jeong Phil Jang, Chang Sub Ku, and Sung Phil Mun
- Subjects
Antioxidant ,Chromatography ,Chemistry ,Depolymerization ,medicine.medical_treatment ,Extraction (chemistry) ,Forestry ,Water extraction ,Plant Science ,Degree of polymerization ,Gel permeation chromatography ,Proanthocyanidin ,Polyphenol ,medicine ,General Materials Science - Abstract
Pinus radiata bark is a rich source of proanthocyanidins (PAs), a potent and valuable plant antioxidant. This study was performed to evaluate PA extraction conditions with water at various temperatures ranging from 25°C to 120°C. The properties of the water extract (WE) obtained at each temperature were investigated in terms of PA content, molecular weight (MW) distribution, and antioxidant activity. The WE yield was significantly dependent on temperature. The PA yield and the absorbance at 280 nm (an indicator of PA concentration) of WE reached maximum values at 80°C, implying increased extraction of monomeric polyphenols. Gel permeation chromatography results suggested that water extraction above 100°C caused depolymerization of extracted PAs, thereby noticeably reducing MW. It was found that more monomeric polyphenols can be extracted by increasing temperature. The WE antioxidant activity was maximized at 80°C and was dependent to some extent on the degree of polymerization.
- Published
- 2011
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43. Effects of Proanthocyanidin-rich Extract from Pinus radiata Bark on Immune Responses of Broiler Chickens
- Author
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Hyung-Kwan Jang, Sung-Phil Mun, Se-Yeoun Cha, Kyung-Seon Ryu, Young-Ho Son, Yang-Seop So, Min Kang, In-Jae Park, and Hiw-Gon Go
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education.field_of_study ,animal structures ,Population ,Broiler ,Biology ,Peripheral blood mononuclear cell ,Andrology ,medicine.anatomical_structure ,Immune system ,Humoral immunity ,Immunology ,medicine ,Interleukin 18 ,education ,CD8 ,B cell - Abstract
Proantocyanidins are naturally occurring compounds that are widely found in fruits, vegetables, nuts, seeds, flowers and bark. In part I, we evaluated the immunomodulatory effects of proanthocyanidin-rich extract (PAE) from Pinus radiata bark in specific pathogen free (SPF) White Leghorn chickens. Proliferation of peripheral blood mononuclear cells was significantly enhanced in chickens treated for 2 weeks with 20 ㎎/㎏ PAE. Proliferation of splenocytes and bursal cells was significantly enhanced in chickens treated for 5 weeks with 5, 10, and 20 ㎎/㎏ PAE. Thymocyte proliferation was significantly enhanced in chickens treated for 5 weeks with 5 and 10 ㎎/㎏ PAE. These effects were markedly enhanced by the presence of lipopolysaccharide, which actedon B cells responsible for humoral immunity, and concanvalin A, which acteddirectly on T cells involved in cell mediated immunity. PAE significantly promoted the expression of Th1 cytokine (interferon-gamma) and decreased the expression of Th2 cytokine (interleukin-6). In part Ⅱ, we evaluated the immunomodulatory effects of proanthocyanidin-rich extract (PAE) from Pinus radiata bark in broiler. Proliferation of peripheral blood mononuclear cells and thymocytes was significantly enhanced in 2.5, 5, 10 ㎎/㎏ PAE-treated broiler chickens. Proliferation of splenocytes was significantly enhanced in 1.25, 2.5, 5, 10 ㎎/㎏ PAE-treated broiler chickens. These effects were markedly enhanced by the presence of LPS, which acts on B cells responsible for humoral immunity, and Con A, which acts directly on T cells involved in cell mediated immunity. PAE significantly promoted the expression of interleukin-18 and interleukin-1 β. In part Ⅲ, We evaluated the immunomodulatory effects of proanthocyanidin-rich extract (PAE) from Pinus radiata bark in Korean native chickens. In experiment 1, proliferation of peripheral blood mononuclear cells (PBMCs) was significantly enhanced in chickens administered for 2 weeks with 1.25, 2.5, 5 and 10 ㎎/㎏ PAE. Proliferation of splenocytes and thymocytes cells was significantly enhanced in chickens administered for 5 weeks with 1.25, 2.5, 5 and 10 ㎎/㎏ PAE. In experiment 2, proliferation of PBMCs, splenocytes and thymocytes in the PAE-administered chickens for 6 weeks were continuously higher than other groups and significantly promoted the expression of Th1 cytokines (IL-2, IL-12, and IFN- γ). Also, the CD4+CD8? (Th1 cell) and Bu-1+ (B cell) cell population significantly upregulated after 4 weeks in PAE-administered chickens.
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- 2010
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44. Chemical characterization of six mangrove species in Bangladesh
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Sung Phil Mun, A. Al-Maruf, M. Sarwar Jahan, and D. A. Nasima Chowdhury
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biology ,Chemistry ,Pulp (paper) ,Forestry ,Avicennia alba ,Plant Science ,engineering.material ,Excoecaria agallocha ,biology.organism_classification ,Syringaldehyde ,Industrial and Manufacturing Engineering ,chemistry.chemical_compound ,Bruguiera gymnorhiza ,Botany ,engineering ,Hardwood ,Heritiera fomes ,General Materials Science ,Mangrove - Abstract
Lack of data especially pertaining to the chemistry of mangrove wood species makes it difficult to prepare successful plans for their conservation and to use mangroves as a source of wood fiber. In this paper, chemical characterizations of the six main mangrove species of Bangladesh [namely Keora (Sonneratia apetala), Geoa (Excoecaria agallocha), Bine (Avicennia alba), Sundari (Heritiera fomes) Pashur (Xyloccarpous mekongests), and Kakra (Bruguiera gymnorhiza)] were investigated. The chemical results revealed that these species contain high percentages of dichloromethane followed by methanol extractives. Methanol extracts in Pashur, Sundari, and Bine were higher than 10%, which indicates high percentage of tannin material. The total lignin content in these species was higher than 25%, except for Gewa (23.6%) and Pashur (21.3%), which is higher than that of the normal range of hardwood. The pentosan content in these six species was within the range of 19.4–22.8%. The α-cellulose content in Keora and Gewa was acceptable for pulp production, but the others were lower than the normal range of hardwood. Alkaline nitrobenzene oxidation showed that all these species had a very high syringaldehyde to vanillin (2.6–5.0) ratio except Keora (1.6). Surprisingly, rhamnose is the main constituent with xylose of hemicelluloses of these six mangrove species. The ash content in these six mangrove wood species was also higher than that in normal hardwood.
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- 2010
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45. Isolation and Characterization of Lignin from Tropical and Temperate Hardwood
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M. Sarwar Jahan and Sung Phil Mun
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Trema orientalis ,biology ,Chemical structure ,Pharmaceutical Science ,biology.organism_classification ,Pulp and paper industry ,Nitrobenzene ,chemistry.chemical_compound ,Complementary and alternative medicine ,chemistry ,Hardwood ,Temperate climate ,Lignin ,Molar mass distribution ,Organic chemistry ,Pharmacology (medical) ,Woody plant - Abstract
Dioxane and milled wood lignins (MWL) were isolated from tropical hardwood, Nalita (Trema orientalis ) and temperate hardwood, aspen. These lignins were characterized by UV, FTIR, 1 H-NMR and 13 C-NMR spectroscopy, alkaline nitrobenzene oxidation, molecular weight determination, elemental and methoxyl analysis. The structural analysis revealed that Nalita and aspen lignin is syringyl-guaiacyl type. Aspen lignin had higher syringyl unit than Nalita lignin. The β-O-4 type linkages are the main interunit linkages and more abundant in aspen than Nalita. Dioxane lignin showed higher free phenolic hydroxyl group than MWL in both species. The weight average molecular weight of aspen lignin was lower than that of Nalita lignin. Nalita and aspen lignins contained both erythro and threo configuration, but erythro proton gave stronger peak. A UV absorption maximum of aspen lignin was at 274 nm, whereas it was shifted to 280 nm for Nalita lignin. Keywords: Trema orientalis , Aspen, Dioxane lignin, Milled wood lignin, Syringyl-guaiacyl, β-O-4 linkages DOI: 10.3329/bjsir.v44i3.4399 Bangladesh J. Sci. Ind. Res. 44(3) , 271-280, 2009
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- 2010
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46. Dyeability with Silk Fabrics and Chemical Composition of Natural Dye PinuxTMManufactured from Pinus Radiata Balk
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Dae-Sung Kim, Young-Ki Hong, Kyung-Hun Song, and Sung-Phil Mun
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Materials science ,biology ,Pinus radiata ,biology.organism_classification ,chemistry.chemical_compound ,SILK ,Proanthocyanidin ,chemistry ,visual_art ,visual_art.visual_art_medium ,Phenol ,Bark ,Dyeing ,Composite material ,Natural dye ,Chemical composition ,Nuclear chemistry - Abstract
The chemical composition of natural powder dye manufactured from Pinus radiata bark and dyeability of dyed silk fabrics with were examined. It is made up of the optimum dyeing condition of silk fabric according to the dyeing concentration, dyeing time, and dyeing temperature. Also, we examined the colorfastness and antibiosis of dyed silk fabrics to washing, rubbing, perspiration and light. For the analysis of the chemical composition of , the total contents of phenolic compound, proanthocyanidin(PA) and anti-oxidative activities of the dye were analyzed. As a result, it was found that the main components of the manufactured from Pinus radiata bark is proanthocyanidin, mostly a flavonoid containing a procyanidin structure, and it consists of approximately 63% phenol. As a result of examining the dyeability of silk fabrics with , it showed that the dyeability was best under the conditions of the concentration of dye (wt/v%), dyeing time of 90 minutes, and dyeing temperature at . It was found that the colorfastness of dyed silk fabrics, colorfastness to washing, perspiration for acidic and rubbing were as good as grade 4 or 4-5. However, the colorfastness to light was low at grade 1, the same as the results of other natural dyed fabrics. As a result of the antibiosis measurement for the -dyed silk fabrics, it showed high antibacterial properties to Staphylococcus sureus at 99.6%.
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- 2009
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47. Studies on the macromolecular components of nonwood available in Bangladesh
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M. Sarwar Jahan and Sung Phil Mun
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Pulp (paper) ,Chemical structure ,food and beverages ,engineering.material ,Degree of polymerization ,Xylose ,Straw ,Crystallinity ,chemistry.chemical_compound ,chemistry ,engineering ,Organic chemistry ,Lignin ,Cellulose ,Agronomy and Crop Science - Abstract
The structural feature of macromolecular component of dhaincha, cotton stalks, jute fiber, rice straw and wheat straw, which are commonly used in paper pulp production in forest deficient countries, was thoroughly studied. Lignin was isolated by classical Bjorkman method and characterized by elemental and methoxyl analysis, alkaline nitrobenzene oxidation, FTIR and 1H NMR spectroscopy. The C9 formulas for cotton stalks, jute fiber, dhaincha, rice straw and wheat straw were C9H8.95O3.53(OCH3)1.00, C9H8.12O4.03(OCH3)1.65, C9H8.10O4.65(OCH3)1.32, C9H8.58O3.74(OCH3)1.23 and C9H8.31O3.54(OCH3)1.23, respectively. The alkaline nitrobenzene oxidation products showed that syringyl to vanilin ratio of these nonwood varied from 1.1 to 2.9. Jute fiber showed the highest syringyl to vanilin ratio that are consistent with C9 formula. The β-O-4 units in these nonwood lignins had predominately erythro stereochemistry type. The crystalline structure of these nonwood cellulose was also studied using X-ray diffraction and FTIR spectroscopy. The proportions of crystallinity, crystal size were varied from plant to plant. Jute fiber showed the highest proportion of crystallinity (73.4%) and crystal size (4.2 nm). The degree of polymerization of these nonwoods cellulose has also been studied. Degree of polymerization of jute cellulose was also the highest (3875). FTIR spectroscopy showed that these nonwoods cellulose was monoclinic unit cell structure (Iβ). Carbohydrate analysis showed that the main sugar component in the hydrolyzates of these nonwoods were xylose apart from glucose.
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- 2009
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48. Pyrolysis GC-MS analysis of tars formed during the aging of wood and bamboo crude vinegars
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Chang Sub Ku and Sung Phil Mun
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Bamboo ,biology ,Syringol ,Tar ,biology.organism_classification ,complex mixtures ,Biomaterials ,chemistry.chemical_compound ,Phyllostachys ,Pinus densiflora ,chemistry ,Organic chemistry ,Phenol ,Food science ,Gas chromatography–mass spectrometry ,Pyrolysis - Abstract
Constituents of tars formed during the aging of bamboo (Phyllostachys pubescens), oak (Quercus serrata), and pine (Pinus densiflora) wood crude vinegars were analyzed by pyrolysis-gas chromatography (Py-GC) and pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS) to investigate their origination. The pyrolysate of tars obtained from the wood and bamboo crude vinegars were almost identical and were primarily composed of phenolic compounds and aromatic hydrocarbons. In addition, during the aging of model wood vinegar that was prepared for comparison with the wood and bamboo vinegars, a marked decrease was observed in the levels of phenolic compounds (phenol; o-, p-, and m-cresol; and syringol). Furthermore, the Py-GC-MS results of the tars produced during the aging of the model wood vinegar revealed that phenolic compounds were primarily responsible for the formation of tar during the aging of wood and bamboo crude vinegars. Pyrroles, which may be derived from the primary pyrolysate of amino acids, nitrogen-containing extracts, or both, were also partially involved in the formation of tar during the aging period.
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- 2009
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49. Liquefaction of cellulose in the presence of phenol using p-toluene sulfonic acid as a catalyst
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Sung Phil Mun and Jeong Phil Jang
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inorganic chemicals ,chemistry.chemical_classification ,General Chemical Engineering ,Liquefaction ,Sulfuric acid ,Ether ,Sulfonic acid ,Toluene ,Catalysis ,chemistry.chemical_compound ,chemistry ,Organic chemistry ,Phenol ,Cellulose - Abstract
The kinetics of p -toluene sulfonic acid (PTSA)-catalyzed cellulose liquefaction in the presence of phenol were investigated at 130, 140 and 150 °C. The resulting liquefied products were also analyzed to evaluate the effectiveness of PTSA as a catalyst during the phenol liquefaction. The liquefaction rate of PTSA was slightly lower than that of sulfuric acid (SA), which was used as a reference catalyst, at each liquefaction temperature. The activation energies of the PTSA and SA catalysts during the phenol liquefaction of cellulose calculated using the Arrhenius equation were 34.5 and 35.5 kcal/mol, respectively. The chemical compositions of the ether extracts in the liquefied products were very similar to both catalysts. Methylene bisphenol and its isomers, which were the primary components in the ether extracts, comprise approximately 30% of the ether extract. The GPC curves of the 80% dioxane-soluble part of the liquefied product indicated that it consists of a remarkable amount of phenol-based trimers to hexomers. The average molecular weight and the polydispersity of the liquefied products were very similar after liquefaction using both catalysts; therefore, differences in the products produced using both catalysts used were not recognized. However the level of combined phenol in the liquefied product produced using the PTSA catalyst was approximately 50% lower than that of the SA catalyst. Although it is believed that this difference may cause retardation of the rate of liquefaction, further experiments are necessary to explain differences in the effectiveness of organic sulfonic acid catalysts during the phenol liquefaction of lignocellulosic biomass.
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- 2009
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50. Adsorption of metal and uranyl ions onto amidoximated Pinus densiflora bark
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Sung Phil Mun, Chang Sub Ku, and Jae Phil Kim
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biology ,Metal ions in aqueous solution ,Inorganic chemistry ,chemistry.chemical_element ,Forestry ,Plant Science ,biology.organism_classification ,Uranyl ,Copper ,Industrial and Manufacturing Engineering ,Metal ,chemistry.chemical_compound ,Hydrolysis ,Adsorption ,Pinus densiflora ,chemistry ,visual_art ,visual_art.visual_art_medium ,General Materials Science ,Acrylonitrile - Abstract
Pine (Pinus densiflora) bark was chemically modified by grafting with acrylonitrile (AN) through Fenton reaction and conversion of the cyano group to an amidoxime group by reaction with hydroxylamine. Treatments of pine bark with 160 mM H2O2 at 40°C yielded ~70% grafting in 6-h reaction. After alkali hydrolysis of amidoximated pine bark (AOPB), its adsorption capacity (q e) for copper ions was largely increased from 0.5 to 1.8 mmol/g. Adsorption of the hydrolyzed AOPB (HAOPB) followed the pseudo-second-order kinetic model. Among the metal ions tested, the order of adsorption capacity (q e) predicted by the kinetic model at equilibrium time was Hg2+ > UO2 2+ > Cd2+ > Cu2+ > Zn2+ > Ni2+. The adsorption process was pH-dependent, and the adsorption equilibrium was observed in the pH range of 6–7 for all the metal ions. Even though pine bark is a good adsorbent for Hg2+ and UO2 2+ ions, it had a poor affinity for the other ions tested. It was obviously found that HAOPB had very high adsorption abilities for heavy metal and uranyl ions.
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- 2009
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