• Microbiology and Biotechnology Letters
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• v.13 no.2
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• pp.103-107
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• 1985

A variety of plasmid curing agents such as sodium dodecyl sulfate, acriflavine, ethidium bromide, and mitomycin-C were used to cure Bacillus subtilis cells of streptomycin resistant factor. The drug susceptibility was increased by 0.1％ sodim dodecyl sulfate at stationary growth phase. The curing frequency was obtained highly at 4 $\mu\textrm{g}$/$m\ell$ of acriflavine, 10 $\mu\textrm{g}$/$m\ell$ of ethidium bromide, and 200 $\mu\textrm{g}$/$m\ell$ of mitomycin-C. respectively. Curing action occurred competitively for the streptomycin and terramycin resistant factors in B. subtilis.

• Structural Engineering and Mechanics
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• v.82 no.4
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• pp.543-556
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• 2022

Fly ash (FA) is the main additive to concretes currently produced. This substitute of ordinary Portland cement (OPC) have a positive effect on the structure and mechanical parameters of mature concrete. Unfortunately, the problem of using FA as the OPC replacement is that it significantly reduces the performance of concretes in the early stages of their curing. This limits the possibility of using this type of concrete, e.g., in the prefabrication, where it is required to obtain high strength composites after short periods of their curing. In order to minimize these negative effects, research has been undertaken to increase the early strength of the concretes with FA through the application of a specially dedicated chemical nanoadmixture (NA) in the form of seeds of the C-S-H phase. Therefore, this paper presents results of tests of modified concretes both with the addition of FA and with NA. The analyses were carried out based on the results of the macroscopic and microstructural tests in 5 time periods, i.e. after: 4, 8, 12, 24 and 72 hours. The greatest increase in mechanical strength parameters and rapid development of the basic matrix phases in composites in the first 12 hours of composites curing was observed.

• Journal of the Korean Graphic Arts Communication Society
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• v.18 no.2
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• pp.13-27
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• 2000

The UV curing industry is one of the most wide application fields in the coating and printing inks industry. Applications extend to general coating for paper, board, wood tapes, compact discs and holograms, ink, photoresists for imaging processes and adhesives for welding and sealing in circuit boards. The UV-curing resins have advantages of quick set, space saving, clean environment and efficient use of energy. The purpose of this study has been to control of morphology structures consist of UV-curing resins and alkyd resins. Therefore, we are investigated with regard to rheology properties on the exposure to UV-curing, structures and mechanical properties for curing films.

• Macromolecular Research
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• v.11 no.4
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• pp.267-272
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• 2003

The isothermal cure reactions of blends of epoxy (DGEBA, diglycidyl ether of bisphenol A)/anhydride resin with polyamide copolymer (poly(dimmer acid-co-alkyl polyamine)) or PEI were studied using differential scanning calorimetry (DSC). Rheological measurements have been made to investigate the viscosity and mechanical relaxation behavior of the blends. The reaction rate and the final cure conversion were decreased with increasing the amount of thermoplastics in the blends. Lower values of final cure conversions in the epoxy/thermoplastic blends indicate that thermoplastics hinder the cure reaction between the epoxy and the curing agent. Complete miscibility was observed in the uncured blends of epoxy/thermoplastics up to $120^{\circ}C$ but phase separations occurred in the early stages of the curing process at higher temperatures than $120^{\circ}C$. According to the rheological measurement results, a rise of G' and G" at the onset of phase separation is seen. A rise of G' and G" is not observed for neat epoxy system since no phase separation is seen during cure reaction. At the onset of phase separation the rheological behavior was influenced by the amount of thermoplastics in the epoxy/thermoplastic blends, and the onset of phase separation can be detected by rheological measurements.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.37 no.1
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• pp.56-62
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• 2024

By introducing curing kinetics and chemo-rheology for the epoxy resin formulation for ultra-high voltage gas insulated switchgear (GIS) Insulating Spacers, a study was conducted to simulate the curing behavior, flow and warpage analysis for optimization of the molding process in automatic pressure gelation. The curing rate equation and chemo-rheology equation were set as fixed values for various factors and other physical property values, and the APG molding process conditions were entered into the Moldflow software to perform optimization numerical simulations of the three-phase insulating spacer. Changes in curing shrinkage according to pack pressure were observed under the optimized process conditions. As a result, it was confirmed that the residence time in the solid state was shortened due to the lowest curing reaction when the curing holding pressure was 3 bar, and the occurrence of deformation due to internal residual stress was minimized.

• The Journal of Korean Academy of Prosthodontics
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• v.30 no.2
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• pp.247-257
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• 1992

The present study quantitates the in vitro cytotoxicity of a variety of denture base acrylic resins using cell culture techniques combined with image analysis to measure nuclear area and DNA contents. In this study, a comparison was made among direct curing, heat curing and microwave curing resins. The results obtained from this study were as follows : 1. Morphologically, cell process and nucleus became prominent but macroscopic difference according to the resins were nit observed. In addition, increased cellular density around the specimen were observed. 2. In DNA contents measurements, $S-G_2M$ phase cell was 15.47%, 14.58% in control and heat curing resin on 1st day and the others group $21.39\sim33.36%$ were measured. 3. Nuclear area and DNA contents were increased on 3rd day except DNA content of the microwave curing resin group. These results suggest that denture base acrylic resins stimulate gingival fibroblasts in vitro, especially stimulation of direct curing resin is larger and longer than the others.

• Bulletin of the Korean Chemical Society
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• v.33 no.2
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• pp.473-482
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• 2012

A novel malemide epoxy containing Co(II), Ni(II) and Cu(II) ions have been synthesized by curing malemide epoxy resin (MIEB-13) and Co(II), Ni(II) and Cu(II) complexes of macrocyclic bis-hydrazone Schiff base. The Schiff base was synthesized by reacting 1,4-dicarbnyl phenyl dihydrazide with 2,6-diformyl-4-methyl phenol. The Schiff base and its Co(II), Ni(II) and Cu(II) complexes have been characterized by elemental analyses, spectral (IR, $^1H$ NMR, UV-vis., FAB mass, ESR), thermal and magnetic data. The curing reaction of maleimide epoxy compound with metal complexes was studied as curing agents. The stability of cured samples was studied by thermo-gravimetric analyses and which have excellent chemical (acid/alkali/solvent) and water absorption resistance. Further, the scanning electron microscopy (SEM) and definitional scanning colorimetric (DSC) techniques were confirmed the phase homogeneity of the cured systems.

• Bulletin of the Korean Chemical Society
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• v.31 no.8
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• pp.2272-2278
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• 2010

A new hybrid thermosetting maleimido epoxy compound 4-(N-maleimidophenyl) glycidylether (N-MPGE) is prepared by reacting N-(4-hydroxyphenyl) maleimide (HPM) with Epichlorohydrin by using benzyltrimethylammonium chloride as a catalyst. The resulting compound possesses both the oxirane ring and maleimide group. The curing reaction of these maleimidophenyl glycidylether epoxy compound (N-MPGE) with amines as curing agents such as ethylendiamine (EDA), diethylentriamine (DETA) and triethylenetetramine (TETA), aminoethylpiperazine (AEP) and isophoronediamine, IPDA), are studied. Incorporation of maleimide groups in the epichlorohydrin provides cyclic imide structure and high cross-linking density to the cured resins. The cured samples exhibited good thermal stability, excellent chemical (acid/alkali/solvent) and water absorption resistance. Morphological studies by the SEM technique further confirmed the phase homogeneity net work of the cured systems.

• Proceedings of the Korean Printing Society Conference
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• 2000.04a
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• pp.61-66
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• 2000

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.27 no.6
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• pp.295-302
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• 2017

In this study, the effect of pre-curing process on the enhancement of mechanical properties of IGCC-slag-based-geopolymer was studied. Pre-curing is a process in which the green geopolymer is left at room temperature for a certain period of time prior to the high-temperature curing, and it is known as increasing the strength of a specimen. Therefore, in this experiment, the compressive strength of the geopolymers was measured according to various pre-curing conditions, and microstructure and crystal phase changes were observed by SEM and XRD, respectively. The W/S ratio was determined to be 0.26, which can offer the maximum geopolymer strength with easy molding ability, and the concentration of the alkali solution was 15 M. Pre-curing was performed at room temperature for 0 to 27 days. Compressive strength of the geopolymer made with pre-curing process increased by 36~87 % compared with the specimens made with no pre-curing process. Those improved compressive strength for the pre-cured geopolymer was confirmed owing to promotion effect of pre-curing process on generation of C-S-H gel and zeolite phases, which were analyzed using by XRD and SEM measurement.