• Advances in nano research
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• v.16 no.4
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• pp.325-340
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• 2024

There are several novel uses for dispersing many nanoparticles into a conventional fluid, including dynamic sealing, damping, heat dissipation, microfluidics, and more. Therefore, melting heat and mass transfer characteristics of a 3-D MHD Hybrid Nanofluid flow over a rotating disc with presenting dufour and soret effects are assessed numerically in this study. In this instance, we investigated both ferric sulfate and molybdenum disulfide as nanoparticles suspended within base fluid water. The governing partial differential equations are transformed into linked higher-order non-linear ordinary differential equations by the local similarity transformation. The collection of these deduced equations is then resolved using a Chebyshev spectral collocation-based algorithm built into the Mathematica software. To demonstrate how different instances of hybrid/ nanofluid are impacted by changes in temperature, velocity, and the distribution of nanoparticle concentration, examples of graphical and numerical data are given. For many values of the material parameters, the computational findings are shown. Simulations conducted for different physical parameters in the model show that adding hybrid nanoparticle to the fluid mixture increases heat transfer in comparison to simple nanofluids. It has been identified that hybrid nanoparticles, as opposed to single-type nanoparticles, need to be taken into consideration to create an effective thermal system. Furthermore, porosity lowers the velocities of simple and hybrid nanofluids in both cases. Additionally, results show that the drag force from skin friction causes the nanoparticle fluid to travel more slowly than the hybrid nanoparticle fluid. The findings also demonstrate that suction factors like magnetic and porosity parameters, as well as nanoparticles, raise the skin friction coefficient. Furthermore, It indicates that the outcomes from different flow scenarios correlate and are in strong agreement with the findings from the published literature. Bar chart depictions are altered by changes in flow rates. Moreover, the results confirm doctors' views to prescribe hybrid nanoparticle and particle nanoparticle contents for achalasia patients and also those who suffer from esophageal stricture and tumors. The results of this study can also be applied to the energy generated by the melting disc surface, which has a variety of industrial uses. These include, but are not limited to, the preparation of semiconductor materials, the solidification of magma, the melting of permafrost, and the refreezing of frozen land.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.14 no.2
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• pp.80-89
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• 2009

The rates of sediment oxygen demand(SOD) and denitrification(DNF) were measured using $^{15}N$ isotope pairing technique in intact sediment cores in the shelf of Dok Island. The SOD and DNF in the continental shelf of Dok Island were ranged from 1.04 to $9.08\;mmol\;m^{-2}\;d^{-1}$ and from 7.06 to $37.67\;{\mu}mol\;m^{-2}\;d^{-1}$, respectively. The SOD and DNF values in this study are higher than typical deep sea sediment. The SOD and DNF in this study were high in the high organic matter content sediment and high organic matter content was promotive of coupled nitrification-denitrification. Organic carbon contents in surface sediment ranged from 1.8 to 2.4%, which is higher than typical deep sea sediments. Therefore we conclude that the organic matter content in surface sediment is determined by the nature of the export production not the water depth in East sea sediment and the nature of the export production also determines remineralization processes such as SOD and DNF in East sea/Ulleung Basin sediment.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.12 no.4
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• pp.349-358
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• 2007

In order to understand biogeochemical cycles of organic carbon in the permeable intertidal sandy sediments of the Nakdong estuary, we estimated the organic carbon production and consumption rates both in situ and in the laboratory. The Chl-a content of the sediment and the nutrient concentrations in below surface pore water in the sandy sediment were lower than in the muddy sediment. The sediment oxygen consumption rates were relatively high, especially when compared with rates reported from other coastal muddy sediments with higher organic carbon contents. This implied that both the organic carbon degradation and material transport in the sandy sediment were enhanced by advection-related process. The simple mass balance estimation of organic carbon fluxes showed that the major sources of carbon in the sediment would originate from benthic microalgae and detrital organic carbon derived from salt marsh. The daily natural biocatalzed filtration, extrapolated from filtration rates and the total area of the Nakdong estuary, was one order higher than the maximum capability of sewage plants in Busan metropolitan city. This implies that the sandy sediment contributes greatly to biogeochemical purification in the area, and is important for the re-distribution of materials in the coastal environment.

• Journal of Environmental Science International
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• v.33 no.4
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• pp.257-268
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• 2024

This study investigated the growth characteristics of Euonymus japonicus, Hedera helix, and Peperomia puteolata treated with different calcium chloride (CaCl₂) concentrations to evaluate salt tolerance limits in hydroculture cultivation. Six concentrations of CaCl₂ (0, 1, 2, 5, 10, and 15 g·L^-1 referred to as Cont., C1, C2, C5, C10, and C15) were applied to solution - grown plant species. The survival rate, growth index, plant height, plant width, leaf width, leaf length, number of leaves, and relative chlorophyll contents were measured at monthly intervals. Euonymus japonicus, Hedera helix, and Peperomia puteolata survived up to C2, C5, and C10 at each CaCl₂ concentration. The Euonymus japonicus was higher in the C1 treatment than in the Cont. for most growth characteristics. Hedera helix had the highest leaf width, leaf length, and number of leaves in the Cont., a significant difference was observed compared with the C1 treatment. The chlorophyll content did not differ significantly between the C5 and Cont. treatments. The leaf width and length of Peperomia puteolata were greater in the C2 and C1 treatments than in the Cont., whereas the number of leaves and chlorophyll content were the highest in C5. Dry weight analysis revealed that Euonymus japonicus, Hedera helix, and Peperomia puteolata were the lowest in the Cont. treatments. Euonymus japonicus was 74% in C15, and Hedera helix, and Peperomia puteolata were analyzed at approximately 37%- 50% and 9%-14%, respectively, regardless of the concentration in the CaCl₂ treatment groups. In indoor hydroponic cultivation, the salt tolerance limit concentrations of Euonymus japonicus, Hedera helix, and Peperomia puteolata are 2, 5, and 10 g·L^-1, respectively, indicating that hydroculture management techniques should be applied at higher concentrations.

• Economic and Environmental Geology
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• v.57 no.2
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• pp.263-270
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• 2024

In this study, impact factors for dehydration with KOMIR-Tube system using flocculant and dewatering tube were evaluated for mine drainage sludges. The experiments were conducted on semi-active facility sludges with water contents above 90 % using KOMIR-Tube system. The flocculant and input amount were determined from laboratory experiment and the dewatering efficiency was verified onsite experiment. The sludge characteristics were identified by instrumental analysis such as zeta potential measurement, particle size analysis, XRD, XRF and SEM-EDS. Selection of flocculants for sludge dewatering treatment need to consider not only precipitated rate but also filterated rate. Floc size has to keep at least 0.7 mm. From on-site experiments, sludge dewatering using KOMIR-Tube system suggests to carry out April and May that is low rainfall and humidity considering to climate conditions. Also, dewatering rate depends on the crystal degree of mineral that mainly makes up sludges. Particularly, goethite of the iron hydroxides has better dewatering rate than ferrihydrite. Ferrihydrite is low degree of crystallinity and uncleared or broad shaped crystal, goethite is good crystallinity with needle shaped crystal so that the effect of flocculation and dewatering showed to depend on the crystal. In results, impact factors of dewatering for mine drainage sludges are related to flocculant, climate, crystallinity and shape of iron hydroxides.

• Food Science and Preservation
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• v.30 no.2
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• pp.235-246
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• 2023

Yellowball (Citrus hybrid cv. Yellowball ) is a new citrus hybrid between Haruka (C. tamurana × natsudaidai ) and Kiyomi (C. unshiu × sinensis) and is known to possess strong antioxidant activity. However, detailed information on the antioxidant components of its peel has not yet been reported. This study evaluated the antioxidant activity of the peel and identified the antioxidant components by fractionating a methanolic extract of Yellowball peels using liquid-liquid extraction with n-hexane, ethyl ether (ether), ethyl acetate (EA), butanol, and water. The phenolic contents and antioxidant activities of the n-hexane, ether, and EA fractions were higher than those of the other fractions, and these fractions were further separated by semi-preparative high-performance liquid chromatography (HPLC). Four antioxidant peaks, EA1, EA2, EA3, and He1, were isolated and analyzed using ultra-performance liquid chromatography-quadrupole-time- of-flight mass spectrometry (UPLC-Q-TOF MS). Sinapoyl glucoside and hesperidin were identified in EA2 and EA3, respectively, and a polymethoxylated flavone (PMF) complex (5-hydroxy-3,6,7,8,3',4'-hexamethoxyflavone, natsudaidain, tetrameth- oxyflavone, and tangeretin) was identified in He1. A compound in EA1 with m/z 223.0246 [M-H] could not be identified and was named unknown2. The antioxidant activity of unknown2 (IC₅₀=69.17 ㎍/mL) was similar to that of Trolox, which was noted as a major antioxidant in Yellowball peel. Further studies on the antioxidant capacity of Yellowball peel are required; however, these results provide a foundation for using Yellowball peel as an antioxidant.

• The Journal of the Convergence on Culture Technology
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• v.10 no.2
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• pp.555-563
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• 2024

We were selected oriental medicinal herbs known to be effective in strengthening muscles, improving sarcopenia, treating arthritis and osteoporosis. Amino acids have been reported to be associated with the above-mentioned effects. During the manufacturing process of water extracts of ginseng and samchae, the content of arginine, a basic amino acid, was significantly reduced. The decrease was 99.48mg/100ml for steamed red ginseng compared to 114.07mg/100ml for dried white ginseng, and 54.69mg/100ml for steamed samchae compared to 118.90mg/100ml for dried samchae. The extracts of the wild roots of Acanthus apias and the above-ground twigs of Acanthus apias showed significantly higher DPPH and ABTS radical scavenging activities. Meanwhile, DPPH activity was higher in steamed red ginseng and steamed samchae compared to dried white ginseng and dried samche, but ABTS activity increased to 66.88% for steamed red ginseng compared to 41.96% for dried white ginseng, but was 77.48% for dried samchae and 77.52% for steamed samchae.

• Korean Journal of Ichthyology
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• v.36 no.2
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• pp.182-187
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• 2024

Feeding habits of the large yellow croaker, Larimichthys crocea, was studied using 816 specimens collected by large pair-trawl fishery from June 2021 to May 2022 in the coastal waters of Jeju Island, Korea. The range of total length was 19.8~57.4 cm. Using the IRI, Pisces were mainly prey component constituted 57.5%. Euphausiacea and Macrura were important prey component constituted 23.2% and 18.7%, respectively. There was a significant difference in the change in diet composition by size group. As the L. crocea grew, the feeding rate of Euphausiacea decreased and the feeding rate of Pisces increased. There were also significant differences in the changes in diet composition by seasonal group. The most important prey species for L. crocea in the winter and spring were Pisces, in the summer it was Macrura, and in the fall it was Euphausiacea. As a result of analyzing the feeding relationship between size groups and season groups, L. crocea showed significant differences in the interaction between size groups and season groups.

• Journal of Nutrition and Health
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• v.57 no.2
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• pp.196-210
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• 2024

Purpose: This study investigated the anti-obesity effects of a combination of Syzygium aromaticum L. and Sorbus commixta Hedl. (SS) in vitro and in vivo. Methods: The extracts of Syzygium aromaticum extract (SA) and Sorbus commixta extract (SC) were prepared individually using distilled water. They were mixed in a 1:2 ratio for use in the experiment. To assess the anti-obesity potential of SS in vitro, we examined cell proliferation, cellular triglyceride (TG), and total cholesterol (TC) levels, as well as lipogenesis and β-oxidation in 3T3-L1 cells. To confirm its anti-obesity potential in vivo, C57BL/6J mice were fed a 60% high-fat diet (HFD) to induce obesity. SA alone, SC alone, and their combination compound, SS (at a dosage of 200 mg/kg) were orally administered for 6 weeks. Thereafter, to conduct a comparative evaluation, serum analysis, western blotting of liver tissues, and histopathological analysis were performed. Results: Both SS200 and SS400 significantly inhibited the cellular TG and TC contents in the 3T3-L1 cells. Furthermore, treatment of the cells with SS (at a dose 200 and 400 ㎍/mL) also led to a noticeable regulation of key lipogenic and β-oxidation factors. Treatment of obese mice with SS resulted in a greater reduction in serum leptin and TG levels compared to treatment with the individual compounds (SA and SC). Furthermore, activation of AMP-activated protein kinase α by SS treatment resulted in the suppression of sterol regulatory element-binding proteins (SREBP)-1, leading to the inhibition of acetyl-CoA carboxylase (ACC) expression. Conclusion: Our results suggest that SS may have the potential to prevent obesity through a reduction in the TG and TC levels and regulation of lipogenesis and β-oxidation.

• Journal of Ecology and Environment
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• v.48 no.1
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• pp.24-31
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• 2024

Background: Honey from different geographical origins can have distinct characteristics due to variations in the floral sources available to stingless bees in different regions. The most abundant stingless bee for meliponiculture in Thailand is Tetragonula pagdeni. However, only a few studies about the properties of honey from a different origin were carried out. The objective of this study was focused on a comparative study to evaluate the melissopalynological, physicochemical, antioxidant activities, and total phenolic contents (TPCs) of stingless bee honey produced by T. pagdeni from different parts of Thailand. Results: Fifty honey samples were collected from five locations, and the physicochemical properties of T. pagdeni honey samples are acidic (pH 3.02-4.15) and have a high water content (18.42-25.06 %w/w), which is related to the regions of meliponary. Melisopalynological analysis reveals the predominant pollen from Melaleuca quinquenervia, Cocus nuciferca, Nephelium lappaceum, Salacca wallichiana, and multiflora honey. All honey samples were analyzed for their TPC and 2,2-diphenyl1-picrylhydrazyl radical scavenging activity. The results show that all samples had high TPC and antioxidant activities with a strong correlation (p < 0.05). Conclusions: The data from this study indicates the importance of geographical origin, which links physicochemical properties, phenolic compounds, and functional characteristics to their floral. Besides, the floral sources and harvesting location affected the properties of stingless bee honey. Our results identify Melaleuca honey as a promising source of phenolic content and antioxidant activity that can be used as a functional food, as well as multiflora and Cocus honey. However, further studies are required to characterize the phenolic compound and its biological potential, which could be a stingless bee honey biomarker and quality control, simultaneously with the physicochemical analysis.