• Journal of the Korean Society of Combustion
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• v.9 no.2
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• pp.38-44
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• 2004

The evolution of incipient soot particles has been examined by high resolution electron microscopy (HRTEM) and elemental analyzer in ethylene-air inverse diffusion flames. Laser Induced Incandescence(LII) and laser scattering methods were introduced for examining the soot volume fraction and morphological properties in combustion generated soot qualitatively. Soot particles, collected by thermophoretic sampling, were analyzed by using HRTEM to examine the nano structure of precursor particles. HRTEM micrographs apparently reveal a transformation of condensed phase of semitransparent tar-like material into precursor particles with relatively distinct boundary and crystalline which looks like regular layer structures. During this evolution histories, C/H analysis was also performed to estimate the chemical evolution of precursor particles. The changes of C/H ratio of soot particles with respect to residence time can be divided into two parts: one is a very slowly increasing regime where tar-like materials are transformed into precursor particles (inception process) the other is an increasing region with constant rate where surface growth affects the increase of C/H ratio dominantly (surface growth process). These results provide a clear picture of a transition to mature soot from precursor materials.

• Korean Journal of Agricultural Science
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• v.10 no.1
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• pp.74-83
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• 1983

In order to examine the relationship of fruit abscission and ethylene evolution in 'Jojuro' and 'Imamuraaki' pear trees, the thinning chemicals, ${\beta}$-naphthalene acetic acid (NAA), O, O-dimethyl-O-(3-methyl-4 nitrophenyl) posphorothioate (MEP), 1-naphthyl N-methyl carbamate (carbaryl), and 2-chloroethyl phosphonic acid (ethephon) were applied. Concurrently the effect of calcium acetate on the control of fruit abscission were examined when calcium acetate was added to ethephon and carbaryl. 1. All the applied chemicals (MEP, NAA, carbaryl and ethephon) was effective to abscise fruits in 'Jojuro', and MEP and carbaryl in 'Imamuraaki's. 2. The application of ethephon increased the ethylene evolution but other chemicals did not increase it. 3. There were no significant differences in total sugar contents of fruits by MEP, NAA, carbaryl and ethephon treatments. 4. When the calcium acetate was added to the ethephon and carbaryl, the thinning effects were offsetted. 5. The rate of defoliation due to ethephon treatment was controlled by addition of calcium acetate at 0.1~0.25 M. It was clarified that fruit abscission induced by thinning chemicals except ethephon was not directly related to ethylene production and that degree of fruit thinning can be regulated by addition of calcium acetate to thinning chemicals.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.28 no.1
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• pp.89-93
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• 1983

Rice plant was tested in the phytotron to know the varietal difference of ethylene production in different nitrogen levels. The high nitrogen concentrated varieties among tested varieties produced a large amount of ethylene. But high nitrogen concentrated leaf in the one variety produced less amount of ethylene. The varieties which produced a large amount of ethylene was remarkably increased ethylene in no nitrogen plot$(N_0)$ compare to standard level$(N_1)$. In contrast low ethylene producing varieties was remarkably decreased in double nitrogen level$(N_2)$.

• Korean Journal of Weed Science
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• v.12 no.1
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• pp.39-45
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• 1992

This experiment was conducted to evaluate the effect of gibberellin biosynthesis retardants as used by rice lodging inhibitors on the gibberellin antagonism, auxin interation, ethylene evolution and growth of second crops. Results obtained can be summarized as follows. Inabenfide, paclobutrazol and uniconazole markedly inhibited the epicotyl elongation of mung bean. Inhibiting effect of epicotyl by these chemicals was markedly stimulated by gibberellic acid, thus showing clear antagonism between these chemicals and gibberellic acid. Significantly large number of roots were formed in the mung bean cuttings which were rooted in the paclobutrazol and uniconazol of 1 ppm. The higher the concentration, the more the number of roots forms. It was guessed that these effect was closely related with auxin. Ethylene evolution was a little stimulated in the leaf of rice under the treatment of inabenfide, paclobutrazol and uniconazole at earlier stage(5 DAT), however it was suppressed at later stage(10, 30 DAT) at higher concentration. The effect of gibberllin biosynthesis inhibitors to second crops retarded tomato plants without influencing the height of barley. The treatment of paclobutrazol and uniconazol which is triazole-type more severely inhibited than that of inabenfide which is isonicotinanilide-type. The more the concentration, the less the height of tomato plants.

• Horticultural Science & Technology
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• v.30 no.6
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• pp.718-724
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• 2012

Sugars play important roles in petal senescence of cut flowers. In the Expt. 1 of this study, the effects of different concentrations of glucose (60, 90, and $120g{\cdot}L^{-1}$) and sucrose (30, 60, and $90g{\cdot}L^{-1}$) application on the vase life, rate of flower diameter increase, rate of flower weight increase and ethylene production of cut tree peony (Paeonia suffruticosa 'Luoyang Hong') were evaluated. At the earlier stage, treatments of different concentrations of glucose and sucrose all retarded the process of flower opening and inhibited the increase of flower diameter and weight, while senescence of flowers fed with different concentrations of glucose was delayed at later stage. Flowers treated with $90g{\cdot}L^{-1}$ glucose displayed the longest vase life, which showed significant difference (P < 0.05) from those of flowers with the control and sucrose treatments. All treatments with glucose or sucrose not only retarded the decrease of flower diameter and weight, but also suppressed the ethylene production at the earlier stage and delayed the peak of ethylene evolution. In order to study the effect of exogenous sugar on the postharvest response of cut tree peony to ethylene, Expt. 2 was conducted. Cut flowers were treated with $90g{\cdot}L^{-1}$ glucose for 4 hours before (GE) or after (EG) exposed to $10{\mu}L{\cdot}L^{-1}$ ethylene for 4 hours. Generally, the opening process of flowers with GE and EG treatments was similar to that of the control, however GE treatment delayed flower senescence. Both GE and EG treatments improved flower diameter and weight, and GE treatment delayed the time of flower weight decrease. Besides, GE delayed climacteric ethylene evolution for 8 hours. All above suggest that exogenous sugars delay tree peony 'Luoyang Hong' cut flower senescence and extend flower vase life through their roles in the decrease of water loss and the suppression of sensitivity to ethylene and ethylene production.

• Korean Journal of Agricultural Science
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• v.25 no.1
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• pp.12-18
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• 1998

This study was conducted to examine the effect of several postharvest treatments on the storable quality of three apple cultivars, 'Tsugaru', 'jonagold', and 'Hokudo' which are difference in harvest season. Ethylene evolution level showed cultivar-dependent pattern during storage and there was no correlation between the amount of ethylene evolution and storage period among cultivars. Polyethylene film(PE) wrapping was effective in the inhibition of water loss and functional ceramic film was also effective in the prevention of ethylene accumulation inside the wrap during 1 to 3 months of cold storage compared to those of simple PE wrapping. Ethylene scrubber and wax treatment positively contributed to keep the fruit firmness 10% higher than that of control fruit during storage. Waxing enhanced the appearance of 'jonagold' even after simulated marketing period through inhibiting wax accumulation on the fruit surface.

• Applied Chemistry for Engineering
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• v.5 no.4
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• pp.609-615
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• 1994

Partial oxidation of ethylene over 10wt% $Ag/{\alpha}-Al_2O_3$ catalyst was studied with a pulse reactor which was connected directly to a G. C. When ethylene was injected after oxygen injection at the temperature where molecular adsorption of oxygen is difficult ethylene oxide was evolved. From the results, it is suggested that adsorbed atomic oxygen is related with the evolution of ethylene oxide. The selectivity to ethylene oxide decreased with the decrease of the amounts of adsorbed oxygen and bulk oxygen. Ethylene oxide was either decomposed to ethylene and adsorbed oxygen or isomerized to acetaldehyde. However, the isomerization of ethylene oxide to acetaldehyde was strongly suppressed by the preadsorbed oxygen.

• Applied Biological Chemistry
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• v.19 no.4
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• pp.202-218
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• 1976

In this experiment American Summer Pairman apple was selected as test fruit in order to study the effect of sub-atmospheric pressure storage in the apple. keeping a certain pressure condition, a new sub-atmospheric pressure system was designed and constructed in which fruits were stored at $25^{\circ}C$ under two different atmospheric pressure conditions such as Normal Atmospheric Pressure (NAP) and Sub-Atmospheric Pressure (SAP). Moreover, they were divided into plots of 5% and 0% of $CO_2$, on the basis of gas composition. Under these conditions, the amount of respiration and ethylene evolution, and the changes of intercellular gas composition and organic components were investigated throughout the storage. The results obtained are as follows: (1) The intercellular gas was exhausted so rapidly by the SAP treatment that the gas equilibrium in the tissues reached within 5 minutes. (2) The amount of respiration was found to be higher in plots of NAP than SAP, and under the conditions, controlling $CO_2$ content, plots of $CO_2$ 5% were lower in the amount of respiration than $CO_2$ 0%. The climateric rise was revealed more slowly in plots of the SAP than NAP. These results indicate that the SAP treatment was an efficient method for controlling the respiration of fruits. Furthermore, these results were also realized with the results of the respiratory quotient (R.Q) and intercellular gas composition. (3) Evolution of ethylene, the ripening hormone in plant, was shown the similar tendency to the climacteric pattern of respiration; at the stage of climacteric maximum, the maximun amount of ethylene was found earlier in plots of NAP than SAP, and post climacteric stage was prolonged in the plots of the SAP compared to those of the NAP. The ethylene concentration in tissue appeared lower in plots of the SAP than NAP, which might suggest that the SAP treatment was caused to restriction of ethylene evolution. (4) Effects of the SAP treatment mentioned hitherto were proved also with the test of the external appearance such as changes of color and freshness, firmness, rotting and weight loss. (5) In the investigation of organic components, vitamin C and organic acids varied less in plots of SAP than NAP. Specially, it was remarkable that the loss of malic acid was least decreased by the SAP treatment. These effects of the SAP treatment were distinctive in the changes of the ratios of malic and citric acid to total acid, and the ratios of free sugar to free acid.

• Korean Journal of Agricultural Science
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• v.37 no.2
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• pp.209-216
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• 2010

In order to understand the effects of a single or combined treatments of 1-MCP($1{\mu}L/L$) and $CO_2$(100%) on the firmness of melting type peach fruit(cv. Chunjungdo), fruit were harvested at commercial maturity and examined physiological changes including flesh firmness during 10 days of shelf-life. Firmness loss of fruit was delayed by both single and combined treatments of 1-MCP and $CO_2$. The treatment of 1-MCP was more effective than $CO_2$ treatment but no additive effective on firmness retention was found in the combined treatment. The upsurge of ethylene evolution occurred 5 days of shelf-life in air treated control but ethylene evolution gradually increased in fruit treated by 1-MCP and 1-MCP+$CO_2$. The suppression of ethylene evolution seemed stronger in $CO_2$ treatment. The respiration of fruit significantly inhibited up to 10 days except control where climacteric increase of respiration was found at 10 days of shelf-life. A molecular shift of pectic polymers(an increase of chelator soluble pectins and decrease of water soluble pectins) was induced by both 1-MCP and $CO_2$ treatments. An increase of water soluble pectins was coincident with firmness loss. The delay of firmness loss seemed to be associated with the migration of calcium to wall matrix, especially pectins, resulting in the increase of wall bound calcium. The polygalacturonase activity was significantly reduced by 1-MCP alone 1 day after treatment and increased to similar level of activity 5 days after treatment compared to other treatment except air treated control whereas pectin methylesterase activity seemed not to be affected by both 1-MCP and $CO_2$ treatments. Thus, the molecular shift of pectic polymers appeared not to be related with pectin methylesterase. Further study is required to clarify the softening mechanism associated with molecular shift of pectic polymers and the inter- or intra-cellular movement of calcium ions induced by postharvest treatments of 1-MCP and $CO_2$.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.32 no.3
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• pp.353-356
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• 1987

To find out the effect of 2.4-D on growth response and fruit quality of strawberry, by leaf treatment (spray) of 120l/10a of 2.4-D(amine salt 40%) 10 ppm solution at flowering stage of 1st cluster, the experiment was carried out in the P-E film covered green-house. The strawberry plant showed the epinastic growing response with long petiole and petide and increased the evolution of ethylene from leaves and fruits after 2.4-D spraying. Therefore, the peak of picking time was accerated about 15 days according to the higher amount of ethylene evolution from strawberry plants, and the yield of fruit increased about 18% by improving the average weight of a fruit.