• Preventive Nutrition and Food Science
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• 제13권4호
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• pp.334-339
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• 2008

This study was designed to determine the optimum conditions of heating temperature, heating time and dilution rates for producing heated garlic juice by using central composite design of response surface methodology. Garlic 3Department of Biosystems Engineering, Chungbuk National University, Cheongju 361-763, Korea was heated using a high temperature and pressure treatment apparatus. Total soluble solid contents ranged from 4.4 at $130^{\circ}C$ 3 hr and 6 fold dilution to 5.89 at $115^{\circ}C$ for 2 hr and 8 fold dilution. The highest total acidity was 0.55% at $120^{\circ}C$ for 3 hr and 2 fold dilution. The pH ranged from 4.01 at $130^{\circ}C$, 3 hr and 6 fold dilution to 5.85 at $120^{\circ}C$, 1 hr and 6 fold dilution. From the results of statistical analysis on the sensory evaluation the predicted optimum processing conditions for best color, taste, flavor and overall acceptance were $119.41^{\circ}C$, 3.11 hr, 5.85 fold dilution, $118.23^{\circ}C$, 3.57 hr, 3.15 fold dilution, $120.54^{\circ}C$, 3.47 hr, 5.01 fold dilution and $119.54^{\circ}C$, 3.18 hr, 5.66 fold dilution, respectively. The application of response surface methodology for preparing heated garlic juice processing showed a good correlation with high significance.

• Tribology and Lubricants
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• 제33권2호
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• pp.65-70
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• 2017

In vertical hydro/hydraulic power turbine-generator applications, traditionally, cylindrical turbine guide bearings (TGBs) are widely used to provide turbine runner shafts with smooth rotation guides and supports. All existing cylindrical TGBs with simple plain pads have drawbacks such as having no pressure generation and film stiffness at the no-load condition and in addition, at the low-load/low-eccentricity condition, having very low film stiffness values and lacking design credibility in the stiffness values themselves. In this paper, in order to fundamentally improve the low-load/low-eccentricity performance of conventional cylindrical TGBs and thus enhance their design-application availability and usefulness, we propose to introduce a rotation-directional leading-edge taper to each partitioned pad, i.e., a pad leading-edge taper. We perform a design analysis of lubrication performance on $4-Pad{\times}4-Row$ cylindrical TGBs to verify an engineering/technical usefulness of the proposed pad leading-edge taper. Analysis results show that by introducing the leading-edge taper to each pad of the cylindrical TGB one can expect a constant high average direct stiffness with a high degree of design credibility, regardless of load value, even at the low-load/low-eccentricity condition and also control the average direct stiffness value by exploring the taper height as a design parameter. Therefore, we conclude that the proposed pad leading-edge tapers are greatly effective in more accurately predicting and controlling rotordynamic characteristics of vertical hydro-power turbine-generator rotor-bearing systems to which cylindrical TGBs are applied.

• 방사선산업학회지
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• 제6권2호
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• pp.159-164
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• 2012

Bacterial cellulose (BC) is generated from citrus gel by Gluconacetobacter hansenii TL-2C. BC has good properties such as high-burst pressure, high-water contact and the ultrafine highly nanofibrous structure of mimic natural extracellular matrix (ECM) for tissue engineering. In this study, acrylic acid (AAc) was grafted onto BC surfaces under aqueous conditions using gamma-ray irradiation, and then immobilized gelatin onto AAc-g-BC. The characterization of scaffolds was performed by scanning electron microscopy (SEM), attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), toluidine blue O (TBO) assay. Morphology of gelatin and AAc incorporation onto BC nanofibers did not changed. Our study suggests that gelatin-immobilized BC nanofibers scaffold has a potentiality to fabricate 3D nanofibrous scaffolds for tissue engineering.

• 대한의생명과학회지
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• 제27권4호
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• pp.291-297
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• 2021

Codonopsis lanceolata, called deodeok in Korean, has been verified for various effects, including anti-aging and anti-inflammatory effects and insomnia improvement, and is one of the healthy foods that Koreans enjoy eating. In this study, the saponin content, lansemaside A content, and total saponin content of deodeok were analyzed using high-pressure sterilization and solid fermentation by mixed lactic acid bacteria. The antioxidant effect was compared to determine improved processing methods of deodeok. The lansemaside A content of deodeok samples depending on the preprocessing methods was analyzed: 2,594.10 mg/kg for dried deodeok, 2,100.93 mg/kg for steamed deodeok, and 1,151.31mg/kg for fermented deodeok. The total saponin content was found to be 7,209 mg/kg for dried deodeok and 8,605 mg/kg for steamed deodeok, showing a high saponin content. The total polyphenol content was highest for dried deodeok, steamed deodeok, and fermented deodeok. As for the antioxidant effect, it was analyzed that the effect of dried deodeok was the highest, followed by steamed deodeok and fermented deodeok; Dried deodeok had the highest value in total polyphenol content, not in total saponin content, which is considered to have a positive influence on its antioxidant effect. The content of lansemaside A was the highest for dried deodeok. When fermented deodeok is consumed, more beneficial effects on health can be expected by ingesting it with lactic acid bacteria cultured using saponins and polyphenols. Therefore, this study suggests the possibility of manufacturing products suitable for the needs of consumers, such as the flavor of deodeok, according to the processing methods.

• 수면정신생리
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• 제29권1호
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• pp.4-8
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• 2022

Obesity hypoventilation syndrome (OHS) is defined as the triad of obesity (body mass index, [BMI] ≥ 30 kg/m²), daytime hypercapnia (PaCO2 ≥ 45 mm Hg), and sleep breathing disorder, after excluding other causes for hypoventilation. As the obese population increases worldwide, the prevalence of OHS is also on the rise. Patients with OHS have poor quality of life, high risk of frequent hospitalization and increased cardiopulmonary mortality. However, most patients with OHS remain undiagnosed and untreated. The diagnosis typically occurs during the 5th and 6th decades of life and frequently first diagnosed in emergency rooms as a result of acute-on-chronic hypercapnic respiratory failure. Due to the high mortality rate in patients with OHS who do not receive treatment or have developed respiratory failure, early recognition and effective treatment is essential for improving outcomes. Positive airway pressure (PAP) therapy including continuous PAP (CPAP) or noninvasive ventilation (NIV) is the primary management option for OHS. Changes in lifestyle, rehabilitation program, weight loss and bariatric surgery should be also considered.

• Genomics & Informatics
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• 제21권3호
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• pp.33.1-33.11
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• 2023

Type 2 diabetes mellitus (T2DM) is a multifactorial, polygenic, and metabolically complicated disease. A large number of genes are responsible for the biogenesis of T2DM and calpain10 (CAPN10) is one of them. The association of numerous CAPN10 genetic polymorphisms in the development of T2DM has been widely studied in different populations and noticed inconclusive results. The present study is an attempt to evaluate the plausible association of CAPN10 polymorphism SNP-19 (rs3842570) with T2DM and T2DM-related anthropometric and metabolic traits in the Noakhali region of Bangladesh. This case-control study included 202 T2DM patients and 75 healthy individuals from different places in Noakhali. A significant association (p < 0.05) of SNP-19 with T2DM in co-dominant 2R/3R vs. 3R/3R (odds ratio [OR], 2.7; p=0.0014) and dominant (2R/3R) + (2R/2R) vs. 3R/3R (OR, 2.47; p=0.0011) genetic models was observed. High-risk allele 2R also showed a significant association with T2DM in the allelic model (OR, 1.67; p=0.0109). The genotypic frequency of SNP-19 variants showed consistency with Hardy-Weinberg equilibrium (p > 0.05). Additionally, SNP-19 genetic variants showed potential associations with the anthropometric and metabolic traits of T2DM patients in terms of body mass index, systolic blood pressure, diastolic blood pressure, total cholesterol, and triglycerides. Our approach identifies the 2R/3R genotype of SNP-19 as a significant risk factor for biogenesis of T2DM in the Noakhali population. Furthermore, a large-scale study could be instrumental to correlate this finding in overall Bangladeshi population.

• Korean Chemical Engineering Research
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• 제59권3호
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• pp.417-428
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• 2021

낮은 반응성으로 인해 복잡한 공정이 필요한 무연탄은 순환유동층 내의 동적 거동을 통해 연소 특성이 고찰되어야 한다. Pilot 규모의 0.1MW_th 급 순산소 순환유동층 연소로에서의 무연탄 연소 특성을 고찰하기 위하여 본 연구에서는 전산유체해석 기법을 이용하였다. 순산소 순환유동층 보일러는 연소로(0.15 m l.D., 10 m High), 싸이클론, 재순환부 등으로 구성되었고 동일한 크기의 3D 모델 반응기를 구축하였다.실험에 사용한 무연탄은 평균 입도 1,070 ㎛, 밀도 2,326 kg/m³이다. 공기 연소에서 순산소 연소로의 연소 환경 변화에 따른 반응기 내부의 기-고 흐름 패턴을 고찰하였다. 이때, 공기 연소와 순산소 연소에서 온도 분포는 비슷한 양상을 보이지만 압력 분포는 순산소 연소에서 더 낮음을 알 수 있었다. 더불어 공기 연소에 비해 순산소 연소에서 더 높은 CO₂ 농도를 가지므로 이산화탄소 포집이 활발히 이루어질 것을 예상해 볼 수 있다. 결과적으로 본 연구를 통해 무연탄 활용 시 순환유동층 반응기의 최적화된 설계 및 운전에 기여할 수 있음을 확인하였다.

• 한국세라믹학회지
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• 제39권5호
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• pp.503-510
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• 2002

가압유동층 복합발전용으로 사용 가능한 탄화규소 캔들형 필터를 압출성형법으로 제조하였다. 필터의 기공율을 조절하기 위해 2.5 vol%의 탄소분말을 첨가하였고, 필터의 강도를 부여하기 위해 무기결합제로써 점토와 $CaCO_3$를 첨가하였다. 평균 기공율이 약 40%, 평균 기공크기가 약 $47{\mu}m$인 지지체 위에 평균 기공크기가 약 $10{\mu}m$를 갖도록 탄화규소 분말을 분무 코팅하였고, 이후 대기압 분위기 하에서 1400${\circ}C$의 온도로 소결하였다. 코팅층이 형성된 캔들형 필터를 500${\circ}C$, $5kgf/cm^2$의 고온, 고압 하에서 성능평가를 행한 결과 입자크기별 집진 성능이 모두 99.99% 이상을 나타내었다. 따라서 제조된 탄화규소 캔들형 필터는 가압유동층 연소가스에 포함되어 있는 미세한 먼지를 효과적으로 제거할 수 있을 것으로 판단되었다.

• 한국임상수의학회지
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• 제27권3호
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• pp.262-267
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• 2010

마그네슘($Mg^{2+}$)은 325 개 이상의 생리적 및 생화학적 과정에 필수적인 조효소이며 신경활성, 심장근 감수성, 신경근 전달, 근수축, 혈관운동 긴장과 혈압 등의 신체활동과 관련된 일련의 과정에서 중요한 역할은 한다. 하지만 신체활동과 관련된 혈액 이온화 $Mg^{2+}$ ($iMg^{2+}$)에 관한 보고는 거의 없을 뿐만 아니라 혈액 총 $Mg^{2+}$을 측정한 연구결과들은 논란의 여지가 있다. 대사적 요구가 증가하는 단기간의 고강도 운동에서 혈액 $iMg^{2+}$의 변화를 측정하였다. 고강도의 수영운동 후에 혈액 산도, 혈당, 중탄산염, 산소 및 칼슘은 감소한 반면, 젖산, 이산화탄소, $iMg^{2+}$, 나트륨, 칼륨은 유효한 증가를 보였다. 고강도 수영에서 혈액 $iMg^{2+}$의 변화는 혈액 산도, 혈당, 중탄산염과 칼슘의 변화와는 역관계의 상관을 보인 반면, 젖산과 음이온차와는 정관계의 유의한 상관을 보였다. 이 결과는 단기간 고강도의 수영운동이 고마그네슘혈증을 야기할 수 있고 이는 대사성 및 호흡성 산증에 의한 근육내 $iMg^{2+}$의 증가에 수반하는 근육에서의 $iMg^{2+}$ 유출의 증가에 의한 것으로 판단된다.

• 환경위생공학
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• 제14권3호
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• pp.54-62
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• 1999

2,4-Dichlorophenol was known pollutants caused by the endocrine disruptor into the refractory substances of environment and this is difficult to be degradable by conventional methods. Therefore, a considerable interest has been devoted to developing new process where 2,4-Dichlorophenol can easily decomposed. In this study, the series of ultrasonic irradiation for removal of 2,4-Dichlorophenol has been selected as a model reaction in the batch reactor system in order to obtain the basic data investigate the influence of various experimental parameters such as concentration, pH, reaction temperature, acoustic intensity. The products obtained form the ultrasonic irradiation were analysed by GC/MS and HPLC. The formation of $H_2O_2$, a well-known the strong oxidant was found proportionally to increase with irradiation time. The intermediates of ultrasonic irradiation of 2,4-Dichlorophenol were identified as HCl, catechol, hydroquinone, o,p-benzoquinone, muconic acid, and maleic acid. The final products of this was $CO_2$ and $H_2O$. As the decomposition of 2,4-Dichlorophenol proceeds by the ultrasonic irradiation, the pH of 2,4-Dichlorophenol containing aqueous solution increases slowly, The decomposition of 2,4-Dichlorophenol was found to be occured fast in the basic medium. In general, the rate of reaction is proportional to the reaction temperature obeying the Arrhenius' law. However, in the ultrasonic irradiation, this suggests as the reaction temperature increase the decomposition rate of the reactant decreases. This result meant that the increase of reaction temperature due to the increase of vapor pressure of water accelerated the decrease of acoustic intensity which was can be proportional to the decomposition rae of these compounds. It was found that more than 80% of phenol solution was removed within hours in all reaction conditions. The reaction order in the degradation of the 2,4-Dichlorophenol compounds was verified as the Pseude-first order. From the fore-mentioned results, it can be concluded that the refractory organic compounds caused by endocrine disruptor as 2,4-dichlorophenol could be removed by the ultrasonic irradiation with radicals, such as $H{\;}{\cdot}{\;}and{\;}OH{\;}{\cdot}$ radical causing the high increase of pressure and temperature. Finally, it apeared that the technology using ultrasonic irradiation can be applied to the treatment of refractory substances caused by endocrine disruptor which are difficult to be decomposed by the conventional methods.