• Bulletin of the Korean Chemical Society
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• v.32 no.2
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• pp.656-658
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• 2011

A green and efficient method for the synthesis of 3,4-dihydropyrimidin-2(1H)-ones and -thiones through one-pot three-component reaction of ethyl acetoacetate, an aryl aldehyde, and urea or thiourea in acetonitrile using silica gel-supported polyphosphoric acid (PPA-$SiO_2$) as catalyst is described. Compared to the classical Biginelli reaction conditions, the present methodology offers several advantages such as high yields, relatively short reaction times, mild reaction condition and a recyclable catalyst with a very easy work up.

• Bulletin of the Korean Chemical Society
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• v.30 no.6
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• pp.1293-1296
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• 2009

A new series of N-substituted 2-n-butyl-3-fluoropyrroles were prepared by a simple one-pot reaction designed of retrosynthesis. $\alpha,\alpha-Difluoro-\gamma-iodo-\gamma$-(trimethylsilyl)propyl n-butyl ketone, a component precursor molecule to 2-n-butyl-3-fluoropyrroles, was prepared with Cu(0) catalyst. It reacted with various primary amines to yield N-substituted 2-n-butyl-3-fluoropyrroles. The products were synthesized via a one-pot reaction scheme between $\alpha,\alpha-Difluoro-\gamma-iodo-\gamma$-(trimethylsilyl) propyl n-butyl ketone and primary amines in excess ( $\geq$ 5 molar equivalence), which eliminate the need of KF required in obtaining n-butyl-1H-3-fluoropyrrole. The yield of products depended reversely on spatial bulkness around N-binding carbon.

• Bulletin of the Korean Chemical Society
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• v.35 no.4
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• pp.994-1000
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• 2014

Synthesis of tetrahydroimidazo[1,2-a]pyridines and tetrahydropyrido[1,2-a] pyrimidines by a one-pot and three component reaction of ${\alpha}$-oxoketenedithioacetals, diamines and DMAD in water has been described. Different routes for accessing the desired compounds were examined and a few specially designed-substrates have been utilized further to afford the new imidazo and pyrido fused [1,8] naphthyridine tetracyclic compound by $S_NAr$ intramolecular cyclization.

• Journal of the Korean Ceramic Society
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• v.44 no.7
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• pp.393-402
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• 2007

Polyaluminocarbosilane was synthesized by direct reaction of polydimethylsilane with aluminum(III)-acetylacetonate in the presence of zeolite catalyst. A fraction of higher molecular weight polycarbosilane was formed due to the binding of aluminium acetylacetonate radicals with the polycarbosilane backbone. Small amount of Si-O-Si bond was observed in the as-prepared polyaluminocarbosilane as the result. Polyaluminocarbosilane fiber was obtained through a melt spinning and was pyrolyzed and sintered into SiC fiber from $1200{\sim}2000^{\circ}C$ under a controlled atmosphere. The nucleation and growth of ${\beta}-SiC$ grains between $1400{\sim}1600^{\circ}C$ are accompanied with nano pores formation and residual carbon generation. Above $1800^{\circ}C$, SiC fiber could be sintered to give a fully crystallized ${\beta}-SiC$ with some ${\alpha}-SiC$.

• Advances in nano research
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• v.5 no.2
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• pp.171-178
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• 2017

Superparamagnetic Zinc ferrite submicropheres are firstly synthesized via a one-pot solvothermal approach at $200-215^{\circ}C$ for 4-8 hours. $ZnCl_2$, $FeCl_3$ and NaAc are used as precursors with ethylene glycol solvent. The X-ray diffraction (XRD) data indicate that $ZnFe_2O_4$ nanoparticles with the grain size around $15{\pm}3nm$ can be successfully synthesized via the one-pot method. The scanning/transmission electronic microscope (SEM/TEM) images further show the samples are submicrospheres self-assembled by nanoparticles with size about 375-500 nm changed with reaction conditions. Room-temperature vibration magnetic strength measurements (VMS) demonstrates the as-obtained $ZnFe_2O_4$ submicrospheres show prefect superparamagnetism, whose coercivity force and remanence are practically nil. The reaction temperature and time influence on the crystallinity, diameter, saturated magnetic intensity and morphology of the particles.

• Nano
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• v.13 no.11
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• pp.1850132.1-1850132.14
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• 2018

The direct synthesis of metal-organic frameworks (MOFs) with acidic and basic active sites is challenging due to the introduction of functional groups by post-functionalization method often jeopardize the framework integrity. Herein, we report the direct synthesis of acid-base bifunctional MOFs with tuning acid-base strength. Employing modulated hydrothermal (MHT) approach, microporous MOFs named $UiO-66-NH_2$ was prepared. Through the ring-opening reaction of 1,3-propanesultone with amino group, $UiO-66-NH_2-SO_3H-type$ catalysts can be obtained. The synthesized catalysts were well characterized and their catalytic performances were evaluated in one-pot glucose to 5-HMF conversion. Results revealed the acid-base bi-functional catalyst possessed high activity and excellent stability. This work provides a general and economically viable approach for the large-scale synthesis of acid-base bi-functional MOFs for their potential use in catalysis field.

• Current Applied Physics
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• v.18 no.11
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• pp.1255-1260
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• 2018

In this work, a green and simple one-pot route was developed for the synthesis of highly fluorescent aminofunctionalized graphene quantum dots (a-GQDs) via hydrothermal process without any further modification or surface passivation. We synthesized the a-GQDs using glucose as the carbon source and ammonium as a functionalizing agent without the use of a strong acid, oxidant, or other toxic chemical reagent. The as-obtained aGQDs have a uniform size of 3-4 nm, high contents of amino groups, and show a bright green emission with high quantum yield of 32.8%. Furthermore, the a-GQDs show effective fluorescence quenching for $Cu^{2+}$ ions which can serve as effective fluorescent probe for the detection of $Cu^{2+}$. The fluorescent probe using the obtained aGQDs exhibits high sensitivity and selectivity toward $Cu^{2+}$ with the limit of detection as low as 5.6 nM. The mechanism of the $Cu^{2+}$ induced fluorescence quenching of a-GQDs can be attributed to the electron transfer by the formation of metal complex between $Cu^{2+}$ and the amino groups on the surface of a-GQDs. These results suggest great potential for the simple and green synthesis of functionalized GQDs and a practical sensing platform for $Cu^{2+}$ detection in environmental and biological applications.

• Korean Journal of Agricultural Science
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• v.4 no.2
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• pp.317-343
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• 1977

This study was carried out to obtain the informations about evaporation from pot, soil temperature and soil atmosphere composition in pot, and the effect on the growth of nine ornamental species using seven different containers. The investigated containers were clay pot(CP), clay pot painted in green(CP-P), varnished clay pot(CP-V), polyethylene film inserting in clay pot(CP-PI), clay pot mulched with black polyethylene film(CP-PM), porcelain pot(POP), and plastic pot(PLP). Nine ornamental species were balsam(Impatiens balsamina), chrysanthemum(Chrysanthemum morifolium), cosmos(Cosmos bipinatus), English ivy(Hedera helix), geranium(Pelargonium zonale), kochia(Kochia scoparia var. trichophila), marigold(Tagetes patula), ornamental kale(Brassica oleraceae var. acephala), and salvia (Salvia splendens). The results obtained are summarized as follows: 1. Dry weight of all tested species grown in PLP, POP, CP-P, CP-V and CP-PI was heavier than that of CP. 2. Plant height in nine tested species grown in PLP, POP, CP-P, CP-V, and CP-PI was taller than that of CP. 3. Geranium grown in PLP, POP, CP-P, and CP-V gave more number of leaf than that of CP. 4. The number of flower in balsam grown in PLP, POP, CP-P, CP-V and CP-PI was more than that of CP. The result from marigold was very similar to this tendency. Spike length and floret number in salvia gave the same tendency, but its spike number was not different among containers used. 5. The average diurnal evaporation from PLP and POP was about 43% of that of CP. About two third of total evaporation from CP was through pot wall. 6. The evaporation rate from the slowest to the highest was PLP, POP, CP-P, CP-V, CP-PI, CP-PM and CP. Containers inhibiting evaporation through pot wall hold more soil moisture than CP from one day after water supply. 7. The more evaporative water-loss from containers gave the lower soil temperature. The variation of soil temperature among containers was higher during the day than the night. 8. The $O_2$ concentration of soil atmosphere in CP was higher than that of nonporous containers, and the difference between them was 0.40-1.12%. The range of the $O_2$ concentration 17.95~19.62%. The $CO_2$ concentration of soil atmosphere in CP was lower than that of nonporous containers, and its range was 0.59-1.76%. This deviation in soil atmosphere composition did not influenced on the growth of plants. 9. There was a possitive correlation between the amount of soil water and the plant growth. 10. Plant grown on CP gave more total nitrogen content in top growth than that on PLP. C/N ratio was somewhat low in plant on CP. From the above results, $O_2$ and $CO_2$ concentration in soil atmosphere did not gave enough deviation to the extent which affect the plant growth. The effect of soil moisture on the plant growth using different containers was the far-most significant factor from this investigation. Therefore, it was obious that the utilization of the nonporous container might save the cost for water supply and reduce the production cost of the pot-grown ornamental plant in Korea eventually.

• Bulletin of the Korean Chemical Society
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• v.33 no.6
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• pp.2079-2082
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• 2012

• The Korea Journal of Herbology
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• v.36 no.3
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• pp.9-14
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• 2021

Objectives : The purpose of this study was to clarify the daily dose and uses of Goju-tang in Treatise on Cold Damage Diseases. Methods : We compared major editions of Treatise on Cold Damage Diseases with the original text of Supplement to the Essential Prescriptions Worth a Thousand Gold and chose the most appropriate text. If none of the existing texts seemed reasonable, We compared texts item by item. When there is nothing adequate even item by item, it was newly modified. These results were compared with currently distributed Pinellia Tuber and standards of eggs. Results : Goju-tang consisted of Goju(vinegar), Pinellia Tuber and an eggshell. Generally, a daily dose was extracted at once and taken 3 times a day, but in Goju-tang, 4 pieces of Pinellia Tuber and one-third Sheong of Goju(solvent) were used, which were one third of average volume. Pinellia Tuber was used cut in small pieces. And it was boiled gradually by low heat. Goju was mainly to reduce the pungency of Pinellia Tuber by cutting raphides of calcium oxalate. The Pot preparing medicines was eggshell which was chosen by its small size, because the volume of Pinellia Tuber and Goju was one-third of average volume. Since an egg shell is consisted of protein, it didn't react with vinegar(Goju). Conclusions : The 4 pieces of Pinellia Tuber and one-third Sheong of Goju(Vinegar) in the Goju-tang were one-third of average dose, and the eggshell was Pot preparing medicines.