• Applied Chemistry for Engineering
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• v.24 no.3
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• pp.320-326
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• 2013

In this study, various polyimide films were synthesized via low temperature cure in order to understand changes in their physical properties when using 4,4'-oxydianiline (ODA) as a diamine and dianhydride molecules with different backbones on a single diamine such as 4,4'-Oxydiphthalic anhydride (ODPA), 4,4-hexafluoroisopropylidene diphthalic dianhydride (6FDA), and 3,3', 4,4'-benzophenone tetracarboxylic dianhydride (BTDA). After the synthesis of poly(amic acid), polyimide films were fabricated by adding 1,4-diazabicyclo [2.2.2]octane (DABCO), a low-temperature catalyst, at various wt% to poly(amic acid)s. Changes of optical and thermal properties were compared and analyzed between polyimide films without catalyst and polyimide films with catalyst by FT-IR, UV-Vis transmittance, DSC/TGA, and WAXD analysis. Wide-angle X-ray diffraction (WAXD) analysis revealed that the mean intermolecular distance decreased with the use of a catalyst by the type of dianhydride. Thus, while the optical properties of the films improve by a low-temperature cure performed using a catalyst, their thermal properties decrease. These changes can be explained by the changes in the morphological structure of the films triggered by a catalyst-induced reduction in the mean intermolecular distance. Moreover, the results show that the type of dianhydride determines the degree of change in the optical and thermal properties in each types of polyimide, demonstrating that changes in the optical and thermal properties are directly associated with the backbone of the polyimide structure.

• Journal of the Korean GEO-environmental Society
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• v.10 no.5
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• pp.33-39
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• 2009

This study was conducted to evaluate production of complex odor and 12 specific odorous compounds in a pilot-scale (capacity : $100m^3$) ultra thermophilic aerobic composting. There were three types input: municipal wasted sludge, livestock manure and slurry, and food waste produced in Jung-Eb city. Each raw material was mixed with seed material and operated for two periods (1st : 50 days, 2nd : 60days). During composting, the temperature hit $90{\sim}95^{\circ}C$ after every mixing in both periods. Therefore, it was concluded that increasing temperature also saves the time which required for composting and high reduction of organics and water contents. The primary odorous compounds were ammonia, methyl mercaltan, dimethyl disulfide and trimethylamine. The concentration of the primary compounds and complex odor during the operation were higher than those on final day and most compounds did not exceed the allowable exhaust standard for odor. Also, it was found that optimal mixing time and control of high temperature are the most important parameters for odor control in ultra thermophilic aerobic composting.

• Journal of the Korean Applied Science and Technology
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• v.39 no.2
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• pp.161-168
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• 2022

Unmodified castor oil (CO) was used to obtain a castor-based aqueous polyurethane (CPUD) and isophorone diisocyanate (IPDI) was used to obtain a transparent film. The mixing effect of polypropyleneglycole (PPG) was analyzed to increase flexibility. In addition, ethylenediamine (EDA) was used as a chain extender. Tensile strength, elongation, and abrasion resistance were measured according to the change according to the castor oil content and the change in the chain extender, respectively. The tensile strength of the sample containing a lot of castor oil was 1.112 kgf/㎟, and the elongation was 88%. The tensile strength of the sample containing a lot of chain extender was 3.33kgf/㎟, and the elongation was 99%. The surface strength was visually confirmed through SEM. The surface strength was visually confirmed through SEM.

• Korean Journal of Food Science and Technology
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• v.50 no.2
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• pp.152-164
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• 2018

Fermented seasoning pastes were prepared by Aspergillus oryzae and Bacillus subtilis using three edible insects, Tenebrio molitor larvae (TMP), Gryllus bimaculatus (GBP), and Bombyx mori pupa (SPP), with soybean (SBP) as a negative control. Volatile compounds were extracted by the headspace solid-phase microextraction (HS-SPME) method and confirmed by gas chromatograph-mass spectrometry (GC-MS). In total, 121 volatiles from four samples were identified and sub-grouped as 11 esters, 18 alcohols, 23 aldehydes, 5 acids, 10 pyrazines, 2 pyridines, 7 aromatic hydrocarbons, 10 ketones, 19 alkanes, 9 amides, 4 furans and 3 miscellaneous. TMP, GBP, SPP and SBP had 48, 54, 36, and 55 volatile compounds, respectively. Overall, 2,6-dimethylpyrazine and trimethylpyrazine were found by a high proportion in all samples. Tetramethylpyrazine, a main flavor of doenjang, a Korean fermented seasoning soybean paste, was identified as one of the major compounds in TMP, SPP, and SBP. SBP had benzaldehyde, hexanal, n-pentanal, and aldehydes and SPP with pyrazines.

• Journal of the Korea Organic Resources Recycling Association
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• v.14 no.2
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• pp.71-82
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• 2006

This study was carried out to assess and analyze the overall problems of the facilities in recycling and treating of foodwaste on the basis of the unit operation facilities. It proposes effective alternatives for the high profitable management that can meet the regulation of the facilities. The study is composed of several parts including a collection of academic reports, field studies regarding the facilities operated by local government and the private sector, the analysis on odor samples from compost facilities and processing facilities for animal feed from foodwaste. Twenty facilities were surveyed on the field to find out the existing problems and to compare between facilities. Several facilities didn't meet the governmental regulation on some processes, especially the stages of input, storage, odor control and the qualities of final products under the unit equipment operation. The analysis on the odors from the phases of input, shredding and fermentation of a compost facility and processing facilities for feed, the odors from shredding equipments were higher in concentration than the others. The Major odors from the composting facility contained hydrogen sulfide ($H_2S$), methyl mercaptan ($CH_3{SH}$), Dimethyl sulfide ($(CH_3)_2S$) and Ammonia ($NH_3$) and the major odors from the animal feed facility contained methyl mercaptan ($CH_3{SH}$), Trimethylamine ($(CH_3)_3N$) and Acetaldehyde ($CH_3CHO$).

• KSBB Journal
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• v.20 no.4
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• pp.323-327
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• 2005

RT-PCR is an useful method to investigate the expression of target gene as detection tools. Although RT-PCR is the powerful detection method for tissues, it was difficult to amplify the target gene product using the single cell. To clarify the expression level of the genes related to Parkinson's disease (PD), I performed the laser dissection of single cell from Substantia nigra. I examined the mRNA expression level in the dopaminergic neuron isolated from the PD patients by the single cell RT-PCR method. It is known that tyrosine hydroxylase (TH), DOPA decarboxylase (DDC) are involved in biosynthesis of the catecholamine such as dopamine. Little has been known about the gene expression features of these enzymes in single dopaminergic neuron. I could detect the specific gene products in single cell level. The different expression was observed in PD-related gene products from the single neuron of PD patients. Interestingly, TH gene expression was significantly decreased with comparing the ratio of decrease in other PD-related genes. Hence, I represented data that indicate the RT-PCR method described in this report is an effective method in detecting a specific single-cell mRNA level related with diseases.

• Applied Chemistry for Engineering
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• v.33 no.3
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• pp.309-314
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• 2022

Carbon dots (CDs) are few nanometer-sized carbon-based nanoparticles and emerging candidate materials in various fields such as biosensors and bioimaging due to their excellent optical properties and high biocompatibility. However, most CDs, emitting blue light, have limited their application in biomedical fields due to the low penetration of short-wavelength lights into the biological system. Therefore, there has been enormous need to develop long-wavelength emitting CDs. In this study, red-emitting CDs were successfully synthesized through the hydrothermal reaction of p-phenylenediamine with hydrochloric acid. In addition, the effect of the amount of hydrochloric acid on the formation of carbon dots, resulting in the variation of the chemical structures of CDs, were investigated, which was confirmed with the intensive structural analyses using infrared and X-ray photoelectron spectroscopy. It was found that the chemical structure of CDs governed their optical properties and quantum yield. Therefore, this study provides an insight into the role of acid in forming red-emitting CDs as the optimal probe for biomedical application.

• Journal of Chest Surgery
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• v.29 no.2
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• pp.191-198
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• 1996

Amrinone is a non-glycosidic, non-adrenergic positive inotropic agent with peripheral and coronary vasodilator effect. It inhibits phosphodiesterase F-III, the cardiac cyclic-AMP specific phosphodiesterase, selectively and potently. In this study, the effects of IV administered amrinone and dopamine were compared in 40 patients who had open heart surgery. Amrinone was administered as a bolus of 1 5~2mglkg for several minutes, followed by continuous infusion at 5~1 Oug/kg/min. The hemodynamic measurements including heart rate, systolic and diastolic pressure, cardiac index, pulmonary wedge pressure, and systemic vascular resistance were recorded immediately for 12~24 hours awl 7th day following operation. In amrinone group, cardiac index increased from 3.73$\pm$1.39 L/min/m2 to 5.44$\pm$2.65 L/min/m2 at the time of posterative 48 hours (n=20, p< 0.05). The decrease in systemic vascular resistance from 1237.5 $\pm$ 637.7 dyne/sec/cm2 to 1000.8 $\pm$ 608.5 dyne/sec/cm2(p<0.05). In Dopamine group, the heart rate increased from 92.1 $\pm$ 13.0/min to 101.0 $\pm$ 13.1/min and the cardiac index decreased from 3.40 $\pm$ 0.50 L/min/m2 to 2.53 $\pm$ 1.15 L/min/m2 at the time of postoperative 12 hours(p<0.05). Systemic vascular resistance increased from 1058.5 $\pm$ 234.6 dyne/sec/cm2 to 1979.7 $\pm$ 759.2 dynelsec/cm2 The comparison of the hemodynamic effects of amrinone and dopamine, both drugs improved cardiac performance. But the administration of amrinone results in a higher cardiac index, diastolic blood pressure and lower systemic vascular resistance than those achieved with dopamine (p<0.05). The uniqueness of the action of amrinone on the heart and its sustained hemodynamic effect suggest it has clinical promise, pos operative care of cardiac surgery