• Resources Recycling
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• v.31 no.3
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• pp.53-60
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• 2022

The physical properties of chlorine-containing cement were analyzed to optimize the operational conditions when waste resources containing chlorine were used in the cement manufacturing process. Cement with clinker to gypsum weight ratios of 95:5 and 93:7 were manufactured. In addition, the iron modulus (IM) of clinker was set to 1.3, 1.5, and 1.7 to evaluate the burnability and physical properties of clinker. With constant chlorine content, increasing gypsum content resulted in a decrease in the 3 day-compressive strength, whereas the 28 day-compressive strength increased. In addition, flow and setting time also increased with increasing gypsum content. As the IM decreased, burnability was improved, free-CaO content decreased, alite and ferrite content increased, and compressive strength increased In particular, the compressive strength of IM 1.3 was approximately 14% greater than that of IM 1.7.

• Journal of the Korean Ceramic Society
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• v.26 no.3
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• pp.323-330
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• 1989

Wear restance titanium carbonitride (TiCN) films were deposited on the SKH9 tool steels and WC-Co cutting tools by plasma assisted chemical vapor deposition (PACVD) using a gaseous mixture of TiCl4, CH4, N2, H2 and Ar. The effects of the deposition temperature and RF(Radio Frequency) power on the deposition rate, chlorine content and crystallinity of the deposited layer were studied. The experimental results showed that the stable and adherent films could be obtained above the deposition temperature of 47$0^{\circ}C$ and maximum deposition rate was obtained at 485$^{\circ}C$. The deposition rate was much affected by RF power and maximum at 40W. The crystallinity of the deposited layer was improved with increasing the deposition temperature and RF power. The TiCN films deposited by PACVD contained much chlorine. The chlorine content in the TiCN films was affected by deposition conditions and decreased with improving the crystallinity of the deposited layer. The deposited TiCN films deposited at the deposition temperature of 52$0^{\circ}C$ and RF power of 40W had an uniform surface with very fine grains of about 500$\AA$ size. The microhardness of the deposited layer was 2,300Kg/$\textrm{mm}^2$.

• Research in Plant Disease
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• v.21 no.2
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• pp.45-49
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• 2015

Seeds of wheat (Triticum aestivum L. cv. Olgeurumil) were infected with Penicillium sp. at mean infection rate of 83%. Penicillium sp. was detected in endosperm with bran but not in embryo. Gaseous chlorine dioxide ($ClO_2$) effectively inhibited growth of Penicillium sp. at concentration of 5 to $20{\mu}g/ml$. As treatment duration was extended from 1 to 3 h, growth of Penicillium sp. was completely suppressed even at $10{\mu}g/ml$. There was no significant reduction in the incidence of Penicillium sp. at 30% relative humidity (RH). However, the incidence of Penicillium sp. was 27.7% at 50% RH, further those were 3.5% and 0.2% at 70% and 80% RH, respectively. Seed germination was not affected by $ClO_2$ treatment at all the RH conditions. Water-soaked seeds (30% seed moisture content) showed a drastic reduction in the incidence of Penicillium sp. when treated at more than $10{\mu}g/ml$ of $ClO_2$. The incidences of Penicillium sp. were 3.3, 1.8 and 1.2% at 10, 15 and $20{\mu}g/ml$, respectively. The incidence of Penicillium sp. in dry seeds with 9.7% seed moisture content did not reduce when treated with 5 and $10{\mu}g/ml$ at 50% RH although it tended to decrease as $ClO_2$ concentration increased to $20{\mu}g/ml$. Seed germination was not affected by $ClO_2$ treatment at the tested concentrations. These results indicated that gaseous $ClO_2$ was effective disinfectant to wheat seeds infected with Penicillium sp. and that the effectiveness of $ClO_2$ strongly increased when moisture content around or inside of the seed was increased.

• Journal of the Korean Applied Science and Technology
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• v.23 no.4
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• pp.328-339
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• 2006

The PU flame-retardant coatings (TTBAH, ATBAH-10C, -20C, and -30C) were prepared using the synthesized ATBAs and HDI-trimer as curing agent at room temperature. The physical properties of PU flame-retardant coatings with chlorine and phosphorus were inferior to those with phosphorus only and the properties were getting worse with increasing chlorine content. Flame retardancy was tested with three methods. With the vertical method, complete combustion time of ATBAHs were $259^{\sim}347$ seconds, which means that the prepared coatings are good flame-retardant. With the $45^{\circ}$ Meckel burner method, char lengths of the three prepared coatings were less than 2.9 cm, which indicates that the prepared coatings are first grade. With the limiting oxygen index (LOI) method, the LOI values of the three prepared coatings were in the range of $30^{\sim}35%$, which proves good flame retardancy of the prepared coatings. from the result of flame retardancy tests of the specimens that contain the same amounts of flame retarding compounds. it was found that the coatings containing both phosphorus and chlorine show higher flame retardancy than the coatings containing only phosphorus. This indicates that there exists, some synergy effect between coexisting phosphorus and chlorine.

• Journal of the Korean Applied Science and Technology
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• v.24 no.1
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• pp.31-46
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• 2007

This study was focused on the maximization of flame-retardancy of polyesters by a synergism of simultaneously introduced chlorine and phosphorus into polymer chains of modified polyesters. To prepare modified polyesters, reaction intermediates, TD-adduct (prepared from trimethylolpropane/2,4-dichlorobenzoic acid (2,4-DCBA)) and TMBO (prepared from tetramethylene bis(orthophosphate)), were prepared first, then condensation polymerization of the prepared intermediates, adipic acid, and 1,4-butanediol were carried out. In the condensation polymerization, the content of phosphorus was fixed to be 2%, and the content of 2,4-DCBA that provides chlorine component was varied to be 10, 20, and 30wt%, and we designated the prepared modified polyesters containing chlorine and phosphorus as ABTT-10C, -20C, -30C. Two-component PU flame-retardant coatings (ABTTC, ABTTC-10C, ABTTC-20C, ABTTC-30C) were prepared by the curing of synthesized ABTTs with a curing agent of allophanate/trimer at room temperature. To examine the film properties of the prepared PU flame-retardant coatings, film specimens were prepared with the prepared coatings. The film properties of ABTTC, ABTTC-10C and ABTTC-20C, which contain 0, 10 and 20wt% 2,4-DCBA, respectively, were proved to be good, whereas the film properties of ABTTC-30C, which contains 30wt% 2,4-DCBA, was proved to be a little bit poor. Two kinds of flame retardancy tests, $^{\circ}45Meckel$ burner method and LOI method were performed. With the $^{\circ}45Meckel$ burner method, three flame-retardant coatings except ABTTC showed less than 3.4cm of char length, and showed less than 2 seconds of afterflaming and afterglow. From this result, the prepared flame-retardant coatings were proved to have the 1st grade flame retardancy. With the LOI method, the LOI values of the coatings containing more than 10wt% 2,4-DCBA were higher than 30%, which means that the coatings possess good flame retardancy. From these results, it was found that synergistic effect in flame retardancy was taken place by the introduced phosphorus and chlorine.

• Food Science and Preservation
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• v.30 no.2
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• pp.190-204
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• 2023

Because of their short harvest season, large quantities of persimmons must often be processed within a limited time. Therefore, new methods to extend their storage life are required. This study examined the effects of chlorine dioxide (ClO₂) gas fumigation for various treatment periods on the storage quality of astringent persimmons Cheongdobansi under low-temperature conditions. The conditions consisted of continuous treatment with ClO₂, treatment for 2 weeks with ClO₂, and no treatment, all of which are stored at low temperatures. Control samples (storage 0 days) without any treatment were prepared and all experiments were conducted for 10 weeks at two-week intervals. The ClO₂ gas treatment maintained the moisture content, color value, hardness, soluble tannin content, and sensory characteristics. However, ClO₂ gas treatment did not affect the soluble solids, pH, and total sugar content. In particular, continuous treatment with ClO₂ maintained the storage quality after 6-8 weeks of storage, particularly the hardness and weakness (sensory evaluation). The results suggest the potential of continuous treatment with ClO₂ as a highly effective method for maintaining the freshness of Cheongdobansi.

• Journal of the Korean Society of Tobacco Science
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• v.16 no.2
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• pp.128-133
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• 1994

This study was carried out to get agronomic information about the tobacco culture in paddy soil where incidence of grey tobacco leaves used to appearly uptake of iron, manganese and chlorine due to soil acidity and high water level. Application of lime to paddy soil(pH5.4-5.6) reduced content of iron, manganese known as proceeding materials giving rise to variegated grey tobacco after curing, compared with non-treatment. Grey leaves were found mainly at lower and middle stalk positions, and incidence of grey tobacco was lowered by application of lime in the well drained field but was not affected by level of fertilizer application. Amendment of soil acidity by lime tended to decrease chlorine and manganese content in leaves. Nicotine and mangenese content of leaves were lowered by reduction of one-quarter fertilizer level. In case of lime treatment, increase of yield reached to 4-6% comparing with those of non-treatment but price per kg was not affected. Reduction of N fertilizer level to three-quarters had the equal yield but high quality of leaf comparing with standard fertilization in paddy field.

• Journal of environmental and Sanitary engineering
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• v.17 no.1
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• pp.63-68
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• 2002

Amount of styrene and divinylbenzene(DVB) was adjusted under injection of nitrogen, copolymer having crosslink of 1%, 2% and 5% was synthesized and zinc chloride was added to it. Put into benzene, swell it, add potassium iodide and 1-aza-15-crown-5 of 21.93g in toluene solution and functional resin which can adsorb heavy metal ions by stir reflex at $55^{\circ}C$ for 30 hours was synthesized. The content of divinylbenzene of this resin was increased as crosslink increase, macroporous gets smaller and the content of chlorine was reduced, which affects macrocyclic ligand in the process of substitution and content of nitrogen was also reduced. And the form of functional synthetic resin was distorted by substitution reaction of hydrogen and chlorine atoms.

• The Plant Pathology Journal
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• v.38 no.5
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• pp.513-521
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• 2022

Our study was carried out to determine the control efficacy of sodium hypochlorite (NaOCl) for violet root rot caused by Helicobasidium mompa in apple. The experiment was conducted in the farm located at Chungbuk province in South Korea from 2014 to 2016. When infected apple trees were treated at least two or three times with 31.25 and 62.5 ml/l available chlorine content in NaOCl, it greatly increased the rooting of rootstock, and restored the tree crown density by 44.4-60.5%. In addition, the number of commercial fruit setting was increased by 54.3-64.5%, and the total starch content in shoots was significantly higher than other non-treated apple trees. However, the untreated disease control and thiophanate-methyl WP treated trees showed the symptom of dieback. Therefore, our results indicate that the drenching treatment of NaOCl with 31.25-62.5 ml/l available chlorine content more than two times from late fall to early spring could effectively control the violet root rot and recover tree vigor up to 60%.

• Resources Recycling
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• v.32 no.6
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• pp.18-24
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• 2023

This study undertook initial investigations into the carbonation of chlorine bypass dust, aiming to apply it as a raw material for cement and as an admixture for concrete. Various experimental methods, including XRD(X-ray diffraction), XRF(X-ray fluorescence), and particle size distribution analyses, were employed to verify the physical and chemical properties of chlorine bypass dust, with and without water washing. The mineral carbonation extent of chlorine bypass dust was examined by considering the dust type, stirring temperature, and experiment duration. Notably, a higher degree of mineral carbonation was observed in water-washed bypass dust than its non-water-washed counterpart, indicating an elevated calcium content in the former. Furthermore, an augmented stirring temperature positively impacted the initial stages of mineral carbonation. However, divergent outcomes were observed over time, contingent upon the specific characteristics of dust types under consideration.