• Journal of Energy Engineering
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• v.26 no.2
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• pp.39-49
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• 2017

Coffee is one of the most popular and consumed beverages in the world, which leads to a high contents of solid residue known as spent coffee grounds (SCG). As is known, coffee beans contain several classes of health related chemicals, including phenolic compounds, melanoidins, diterpenes, xanthines and carotenoids. The waste water coming out of coffee industries has high concentration of organic pollutants and is very harmful for surrounding water bodies, human health and aquatic life if discharged directly into the surface waters. Hence it is essential to treat and manage the coffee waste. Oyster shells are a waste product from mariculture that creates a major disposal problem in coastal regions of southeast Korea. In the study, the oyster shell waste was used to treat the coffee waste and its effluents. Oyster shells are calcined at $1000^{\circ}C$ for 2 h, and allowed to test the calcined CaO powder ability to inhibit the growth of bacteria in different aging coffee wastes. Calcined oyster shell powder showed anti-bacterial effect that inhibited cell growth of Escherichia coli and other bacterial forms. The antimicrobial activity of calcium oxide from oyster shell waste for biological treatment and utilization as a fertilizers with economic ecofriendly in nature.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.49 no.2
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• pp.93-101
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• 2000

This paper presents a novel method for the transient of eddy currents in the dampers of a super-conducting synchronous generator(SCG). The method proposes a 2-D corrected model which takes into account the influence of leakage fluxes of the field winding ends by increasing the effective air gap in order to consider the high precision of the analysis for the conventional 2-D model. The electromagnetic fields for the corrected model are analyzed by the time-stepping finite element method, thus the eddy currents in the dampers and electro-motive forces(EMF) in the stator windings are calculated. As the results, it is proved the presented method is comparatively accurate by comparing measured phase EMF values and the simulation ones, where about 6.4% error at the maximum value of EMF is occurred between them.

• Physical Therapy Rehabilitation Science
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• v.12 no.1
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• pp.56-61
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• 2023

Objective: Core training is a key exercise for conditioning and fitness programs, injury prevention, and more. This study aimed to find out the effect of adding dynamic core training, which is frequently prescribed in clinical practice, on dynamic balance and muscle activity compared to conventional static core training. Design: An experimental study Methods: This study is an experimental pilot study of prospective parallel design. Six healthy young adults were allocated to static core training group (SCG; crunch and plank) and blended group (BG; crunch, plank, and dead bug exercise) for two weeks to perform core training. Dynamic balance and muscle activity (erector spinae, rectus abdominis) were measured for all participants before and after core training. Results: All six healthy young adults enrolled completed the study. No significant difference was found before and after 6 sessions of core training in each group (P>0.05). Likewise, no significant difference was found in the results of the difference comparison between groups (P>0.05). Conclusions: In conclusion, in this experimental study, no difference was found when dynamic core training was added. Although the results before and after core training did not show improvement in dynamic balance and muscle activity, a randomized controlled trial is needed considering the results of previous studies and the limitations of this experimental study.

• Wind and Structures
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• v.36 no.6
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• pp.423-434
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• 2023

Aerodynamic force coefficients are generally obtained from traditional wind tunnel tests or computational fluid dynamics (CFD). Unfortunately, the techniques mentioned above can sometimes be cumbersome because of the cost involved, such as the computational cost and the use of heavy equipment, to name only two examples. This study proposed to build a deep neural network model to predict the aerodynamic force coefficients based on data collected from CFD simulations to overcome these drawbacks. Therefore, a series of CFD simulations were conducted using different geometric parameters to obtain the aerodynamic force coefficients, validated with wind tunnel tests. The results obtained from CFD simulations were used to create a dataset to train a multilayer perceptron artificial neural network (ANN) model. The models were obtained using three optimization algorithms: scaled conjugate gradient (SCG), Bayesian regularization (BR), and Levenberg-Marquardt algorithms (LM). Furthermore, the performance of each neural network was verified using two performance metrics, including the mean square error and the R-squared coefficient of determination. Finally, the ANN model proved to be highly accurate in predicting the force coefficients of similar bridge sections, thus circumventing the computational burden associated with CFD simulation and the cost of traditional wind tunnel tests.

• Korean Journal of Environmental Agriculture
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• v.36 no.2
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• pp.129-134
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• 2017

BACKGROUND: Yeasts are used in a variety of industries. However, most industries are biased toward Saccharomyces cerevisiae ; so we sought to explore non-conventional yeasts (NCY). This study aimed to isolate yeasts from seawater collected from the East Sea of Korea and to analyze the NCY. METHODS AND RESULTS: We first collected seawater and performed pure isolation using four kinds of medium (GPY, DOB + CSM, DG18, and SCG). In total, 314 strains and 17 genera were isolated by ITS sequencing, including Aureobasidum pullulans (236 strains), Cryptococcus (19 strains), Cystobasidium (18 strains), and Rhodotorula (9 strains). Upon in-depth analysis, A. pullulans, the most dominant genus (236 strains), was divided into Group II (147 strains), Unknown I (8 strains), and Unknown II (49 strains). CONCLUSION: In this study, a total of 314 strains were isolated from seawater; many of these yeasts have been found and reported in seawater previously. In-depth analysis of A. pullulans, showed the dominance of Group I (21 strains) and Group II (147 strains) We also discovered Unknown I (8 strains) and Unknown II (49 strains), which have not been reported previously.

• Journal of Haehwa Medicine
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• v.29 no.1
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• pp.18-25
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• 2020

Objective: The goal of this study is to investigate whether peripheral axonal regeneration is affected by diabetes in experimental animals. Method: Sprague Dawely rat was injected with 45~50 mg/kg of streptozotocin (STZ) to generate an animal model of diabetes. Three months after STZ injection, sciatic nerve (2 cm length) was removed and the same length of nerve segments from STZ-injected animal or from control animal (CTL) was transplanted into STZ-injected animals (STZ-STZ and STZ-CTL respectively). Similarly, sciatic nerve segments from STZ-injected animal or from control animal were grafted into the control animals (CTL-STZ and CTL-CTL respectively). All animals were sacrificed 2 weeks after transplantation. Sciatic nerve sections were prepared and subjected to immunofluorescence staining analysis. Results: Immunofluorescence staining for NF-200 showed that distal elongation of regenerating axons reached 40~80% of proximal neve in both CTL-STZ and CTL-CTL groups. However, distal elongation in both STZ-STZ and STZ-CTL groups were 20~60% of proximal nerve. Furthermore, measurement of axonal regeneration after immuno-staining with SCG10 showed that the scores of distal elongation relative to proximal nerve were 50~90% in CTL-CTL and CTL-STZ groups and 10-60% in STZ-CTL and STZ-STZ. Conclusions: Our data showed that the levels of axonal regeneration were not affected irrespective of whether they were from STZ- or CTL graft, but were greatly reduced when the nerves were transplanted into the STZ host.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.4
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• pp.505-514
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• 2015

This paper proposes a probabilistic generation assessment model of renewable energy generators(REGs) considering uncertainty of resources, mainly focused on Wind Turbine Generator(WTG) and Solar Cell Generator(SCG) which are dispersed widely in South Korea The proposed numerical analysis method assesses the one day-ahead generation by combining equivalent generation characteristics function and probabilistic distribution function of wind speed(WS) and solar radiation(SR) resources. The equivalent generation functions(EGFs) of the wind and solar farms are established by grouping a lot of the farms appropriately centered on Weather Measurement Station(WMS). First, the EGFs are assessed by using regression analysis method based on typical least square method from the recorded actual generation data and historical resources(WS and SR). Second, the generation of the REGs is assessed by adding the one day-ahead resources forecast, announced by WMS, to the EGFs which are formulated as third order degree polynomials using the regression analysis. Third, a Renewable Energy Generation Assessment System(REGAS) including D/B of recorded actual generation data and historical resources is developed using the model and algorithm predicting one day-ahead power output of renewable energy generators.

• Advances in nano research
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• v.12 no.3
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• pp.291-300
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• 2022

The behavior of hydrogen species on the surface of the catalyst during the Lewis acid transformation to form Brønsted acid sites over the spherical silica-supported WO_x catalyst was investigated. To understand the structure-activity relationship of Lewis acid transformation and hydrogen bonding interactions, we explore the potential of using the in situ diffuse reflection infrared Fourier transform spectroscopy (DRIFTS) with adsorbed ammonia and hydrogen exposure. From the results of in situ DRIFTS measurements, Lewis acid sites on surface catalysts were transformed into new Brønsted acid sites upon hydrogen exposure. The adsorbed NH₃ on Lewis acid sites migrated to Brønsted acid sites forming NH⁴⁺. The results show that the dissociated H atoms present on the catalyst surface formed new Si-OH hydroxyl species - the new Brønsted acid site. Besides, the isolated Si-O-W species is the key towards H-bond and Si-OH formation. Additionally, the H atoms adsorbed surrounding the Si-O-W species of mono-oxo O=WO₄ and di-oxo (O=)₂WO₂ species, where the Si-O-W species are the main species presented on the Inc-SSP catalysts than that of the IWI-SSP catalysts.

• Korean Journal of Environmental Agriculture
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• v.32 no.3
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• pp.240-243
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• 2013

BACKGROUND: Several yeast species have potential applications in biotechnology and the identification of such yeast species is of great interest. The first step in the identification of yeasts is the establishment of an effective isolation method. Thus, we compared the efficacy of different yeast media in the isolation of yeast associated with Aloe vera and Aloe saponaria. METHODS AND RESULTS: In this study, we spread homogenized A. vera and A. saponaria leaves onto 4 different yeast selective media containing chloramphenicol, streptomycin, Triton X-100 and L-sorbose. We observed high selectivity for yeast and many colonies on media. We isolated 67 yeast strains from A. vera and 42 yeast strains from A. saponaria. We used phylogenetic analysis to identify the yeast isolates based on ITS region sequencing and performed sequence analysis on representative isolates from each agar plate. Further, we compared the sequences obtained with reference sequences. The yeast species isolated from A. vera were as follows: 56 isolates of Meyerozyma, 9 isolates of Cryptococcus, and 1 isolate each of Rhodotorula and Sporobolomyces. Those isolated from A. saponaria were as follows: 41 isolates of Rhodosporidium and 1 isolate of Sporobolomyces. CONCLUSION(S): All the isolates obtained using large agar plate containing chloramphenicol, streptomycin, Triton X-100 and L-sorbose were identified as yeast. Therefore, we concluded that this method is useful for selective screening of yeast species.

• Progress in Medical Physics
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• v.11 no.1
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• pp.29-38
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• 2000

The signal transduction pathway for most neurotransmitter induced inhibition of $Ca^{2+}$ channels in sympathetic neurons involves a G-protein mediated, membrane-delimited mechanism without the participation of any known protein kinase. However, activation of protein kinase C (PKC) has been proposed as one of the intracellular mechanisms mediating some neurotransmitter induced $Ca^{2+}$ channel inhibition. In the present study, we investigated the effects of phorbol-12, 13-dibutyrate (PDBu) on $Ca^{2+}$ channel currents of acutely dispersed neurons from adult rat superior cervical ganglion (SCG) neurons using whole cell variant of the patch clamp technique. PDBu (500 nM), the activator of PKC, increased $Ca^{2+}$ channel currents and retarded the deactivation of tail currents. The effects of PDBu were voltage dependent and the maximal increase in the current amplitudes was observed between -10 to 10 mV (n=4). PDBu attenuated $Ca^{2+}$ current inhibition induced by norepinephrine (NE), which modulates $Ca^{2+}$ channels via a pertussis toxin (PTX)-sensitive pathway. Inhibition of PDBu by staurosporine (1 $\mu$M) blocked the effects of PDBu on current amplitudes and NE-induced G-protein mediated inhibition of $Ca^{2+}$ currents. Further experiment should be done to know if G-protein or $Ca^{2+}$ channel itself is the target of PKC phosphorvlation.phosphorvlation.