• Journal of Bio-Environment Control
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• v.14 no.3
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• pp.160-165
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• 2005

Since the growth and quality of oak mushrooms are sensitively affected by environmental conditions, an adequate environmental control is very essential to improve the yield and quality under protected cultivation. In this study, the diameter, thickness, length and hardness of cap and stipe, the dry weight, fresh weight and moisture content of the mushrooms were analyzed under the environmental conditions such as night air temperatures (control, $5{\~}11^{\circ}C$ and $12{\~}18^{\circ}C$), relative humidities in the daytime (control, humidifying for 6 h and 12 h), and wind velocities (control, fan-operation for 6 h and 12 h). At a lower night temperature, the quality of the mushrooms was improved, and considered to be optimum at $3{\~}8^{\circ}C$ in terms of fresh weight and quality. At $70{\~}80{\%}$ of relative humidity in the daytime, the fresh weight was increased, but the quality decreased. Considering the quality, the relative humidity in the daytime is adequate at around $50{\%}$. At 6 h of maintaining the wind velocity at $1{\~}2\;my{\cdot}s^{-1}$, the growth and quality were better, but the lightness became higher at 12 h although the fresh weight was reduced by evaporation. It is concluded that even though both of the yield and quality are not easily improved at a same time, optimum approaches should be required by using the relationship among environmental factors and the growth and quality.

• Journal of the Korean Wood Science and Technology
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• v.38 no.1
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• pp.66-74
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• 2010

This study was carried out to investigate the optimum condition for sap exudation of Acer mono Max. tree in a site of Mt. Baekun, Kwangyang city, Korea. Amount of sap exudation, air temperature, relative air humidity and tree diameter at breast height (DBH) were monitored for the period of January 5 through March 28, 2008, and correlation analysis of several factors affecting on sap exudation was carried out. As the diameter of Acer mono at breast height increased, the amount of sap was linearly proportional. Sap exudation initiated at February 18, and occurred intensively in the period of February 28 through March 10, resulting in 84% of total sap amount by volume. During sap exudation, the minimum temperature was averaged at $-2.4{\pm}1.5^{\circ}C$ and the maximum at $6.0{\pm}1.8^{\circ}C$, while there was no sap exudation whenever temperature was below or above $0^{\circ}C$ all the day long. The maximum temperature, range of temperature and the maximum, minimum and mean humidities in air were significant factors affecting on amount of sap. The maximum air temperature had the highest correlation coefficient with 0.768 (P < 0.01) and was also considered as the principal factor by partial-correlation analysis. These results showed that sap exudation required daily air-temperature fluctuation from below to above $0^{\circ}C$, and the amount of sap was strongly dependent on the highest daily-temperature and DBH of tree.

• Journal of Bio-Environment Control
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• v.11 no.4
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• pp.175-180
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• 2002

This study was conducted to examine the effect of row covering materials on the growth and yield of broccoli for early production in the open meld. Materials for plastic tunnel were row-covering (ventilating non-woven fabric), perforated film (2.3％ pore space) and P.E. film. The types of row covers were tunnel and covering period was one months after transplanting. The row cover and perforated film increased daily air and soil temperature by 3~4$^{\circ}C$ and 2~3$^{\circ}C$, respectively as compared to no covering. Also, relative humidities in those treatments were higher than those in P.E. and no covering. The row covering and perforated film enhanced plant growth. Broccoli grew best and abnormal head appeared the least with row covering treatment. Days taken for head formation, however, did not differ between treatments but the weight of curd was over 400 g in the treatment of row covering and perforated film covering. Marketable yield doubled under row covering as compared to no covering. The first harvest time was earlier by two weeks in row-covering. The results of this experiment indicated that covering row-cover film in spring cultivation was effective fer not only yield increase but also quality evaluation in early production of broccoli.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.6 no.1_2
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• pp.37-43
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• 1973

In this paper, non-enzymatic browning reactions as a factor of self stability of boiled and dried anchovy were studied to discuss the effect of water activity to the discoloring reaction and the preservative moisture content. The development of rancidity of the fish meat was also mentioned since the fish is fatty and the lipid oxidation is a functional deteriorative reaction. Fresh anchovies were boiled in $10\%$ salt solution immediately after the catch, sun dried, and stored at room temperature ($20^{\circ}C$) for two months in humidistat chambers maintaining different levels of water activity as described in Table 1. The pigments formed by non-enzymatic browning reations were extracted in two fractions, those were chloroform-methanol soluble and water dialyzed fraction, and analyzed spectrophotometrically at the wavelength of 460 nm. These two fractions were considered, respectively to be the brown pigments formed by lipid oxidation reactions for the formler and for the latter, to be the pigments developed by sugar-amino or Maillard reaction. The oxidation of lipid in anchovy meat during the storage was measured as the changes in Peroxide value and the color development of thiobarbituric acid reaction. It is summarized from the results that the rate of both reactions, lipid oxidation and browning, was affected by water activity levels. In regard to the changes in peroxide and TBA value during the storage, the propagation of lipid oxidation was obviously accelerated at lower humidities whereas the development of browning progressed at the higher. These two reactions occurring simultaneously and contrary in activity resulted in that the rate of deterioration occurring oxidatively or by browning, was the minimum at the water activity of 0.32-0.45 which were $7-9\%$ as moisture content and slightly higher value than that of monolayer (Aw=0.21, $5.11\%$ as moisture content). It is also noted that the lipid oxidative browning was presumed to dominate sugar-amino reactions so that the rate of browning of the meat was ultimately depended on the development of rancidity although sugar-amino reactions initiated earlier than the other at the first ten days of storage, particulary at higher humidity. At the lower humidity sugar-amino reactions were occurred gradually but lower levels in color development in contrast to the consistent increase in lipid oxidative browning.

• Korean Journal of Food Science and Technology
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• v.28 no.3
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• pp.545-551
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• 1996

Water-vapor transmission rate and water-vapor permeability of carrageenan-based edible film with three different thicknesses of 0.05, 0.08 and 0.11 mm were measured to investigate the potential applicability of the films to powder foods at five different temperatures (20, 25, 30. 35 and $4^{\circ}C$) and three different relative humidities (50. 70 and 90% RH). Water-vapor transmission rate of the carrageenan-based film was gound to be 2.3 times higher than that of polyethylene (PE) film and water-vapor permeability of the film was 45-230 times higher than that of PE film. Water-ydpor permeability of the film seemed to increase linearly with the film thicknees like other hydrophilic edible films. Water-vapor transmission rate were found to be dependent on the temperature. Activation energies of the water-vapor transmission rate of the film were found to be between 7.898 and 12.8702 kj/mol depending on the film thickness. The water-vapor transmission rate of the film showed the typical kinetic compensation effect between activation energies and preexponential factors. which was proved by the linear increase in the value of logarithms of preecponential factor.

• Korean Journal of Food Science and Technology
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• v.37 no.6
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• pp.1028-1034
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• 2005

Effects of temperature and relative humidity on contents of water-soluble vitamins (vitamins $B_1,\;B_2,\;B_3,\;B_6$, and C) of two commercial tablets ("Multivitamin Dandelion" and "Chewable vitamin C") were investigated. When stored at various temperatures (25, 35, and $45^{\circ}C$) with cap, all measured vitamins were stable and degraded very slowly during 24 weeks of storage; low relative humidity (11% RH) without cap also provided stability during storage period. At higher relative humidities (75 and 100% RH), contents of all water-soluble vitamins, except vitamins $B_2\;and\;B_3$, decreased significantly at early storage period. These results showed that stability of water-soluble vitamins is highly dependent on relative humidity rather than storage temperature.

• Proceedings of the Ginseng society Conference
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• 1988.08a
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• pp.99-107
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• 1988

Samples of red ginseng. which had been manufactured and packaged by the Korea Monopoly Corporation. were stored at ambient temperatures $(12-28^{\circ}C)$ and humidities $(55-68\%)$ for one to nine years to examine their overall quality stability and. in particular. antioxidant activity. The approximate compositions. contents of various solvent extracts. and TLC and HPLC patterns of ginsenosides in the samples which are otherwise susceptible to oxidation. were stable as judged by the changes of the TLC and GLC patterns of the lipids and fatty acids. It was also found that polyunsaturated fatty acids such as linoleic (C18: 2) and linolenic acid (C18: 3) present in the samples had been very stable during the long storage periods. The intensity of the brown color of the red ginseng samples increased significantly with storage time. The pH of the aqueous extracts of the samples also increased slightly during storage. The coloration changes seem to indicate that extensive browning reactions had occurred during storage. The reducing powers of aqueous and ethanol extracts and antioxidant activity of ethyl acetate extracts also increased with storage time. The increase in reducing powers and antioxidant activity appeared to be directly attributable to the increased amounts of non-enzymatic browning reaction products formed progressively during the long storage periods. Therefore. it seems that those antioxidative compounds. which will be progressively formed in red ginseng through non-enzymatic browning reactions during the manufacturing process and long-term storage. will not only contribute to their overall quality stability but also have some significant relationship with their antiaging pharmacological effects.

• Journal of the Korean earth science society
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• v.30 no.2
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• pp.185-195
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• 2009

We investigated the change of several meteorological variables due to deforestation. We established two sets of automatic weather observation system: one on a hill where forest was destructed by lumbering (Point 1) and the other in a neighboring district (Point 2) of fairly preserved forest. The observations were continued for one year (2006. 12-2007. 12). In this study, we analysed the data observed for one week from the nea day after summertime rainfall. The results showed that the air temperatures of Point 1 were about $1.5^{\circ}C$ higher than those of Point 2 during the daytime. But there were small gaps between the two poults during the nighttime. The relative humidities also differed greatly between the two during the daytime. It was as high as about 10% at Point 2. The surface and underground (15 cm in depth) soil temperatures were also fealty different between the two points during the daytime. They were $3-10^{\circ}C$ higher at Point 2 than those of Point 1. And the gaps reduced drastically during the nighttime. The averaged soil moistures were 7.1% at Point 1 and 19.5% at Point 2 during the observation period, respectively. The differences of wind direction were small, but the wind speeds differed between the two points. The observed wind speeds during the observation period were roughly estimated to be about 0.5m/s at Point 1 and 0.3m/s at Point 2. The heat budget analysis was also performed based on the observation data.

• Journal of Korean Society for Atmospheric Environment
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• v.24 no.1
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• pp.91-99
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• 2008

A multilayer tower-type photoreactor, in which $TiO_2$-coated glass-tubes were installed, was used to measure the vapor-phase BTEX removal efficiencies by ozone oxidation ($O_3$/UV), photocatalytic oxidation ($TiO_2$/UV) and the combination of ozone and photocatalytic oxidation ($O_3/TiO_2$/UV) process, respectively. The experiments were conducted under various relative humidities, temperatures, ozone concentrations, gas flow rates and BTEX concentrations. As a result, the BTEX removal efficiency and the oxidation rate by $O_3/TiO_2$/UV system were highest, compared to $O_3$/UV and $TiO_2$/UV system. The $O_3/TiO_2$/UV system accelerated the low oxidation rate of low-concentration organic compounds and removed organic compounds to a large extent in a fixed volume of reactor in a short time. Therefore, $O_3/TiO_2$/UV system as a superimposed oxidation technology was developed to efficiently and economically treat refractory VOCs. Also, this study demonstrated feasibility of a technology to scale up a photoreactor from lab-scale to pilot-scale, which uses (i) a separated light-source chamber and a light distribution system, (ii) catalyst fixing to glass-tube media, and (iii) unit connection in series and/or parallel. The experimental results from $O_3/TiO_2$/UV system showed that (i) the highest BTEX removal efficiencies were obtained under relative humidity ranging from 50 to 55% and temperature ranging from 40 to $50^{\circ}C$, and (ii) the removal efficiencies linearly increased with ozone dosage and decreased with gas flow rate. When applying Langmuir-Hinshelwood model to $TiO_2$/UV and $O_3/TiO_2$/UV system, reaction rate constant for $O_3/TiO_2$/UV system was larger than that for $TiO_2$/UV system, however, it was found that adsorption constant for $O_3/TiO_2$/UV system was smaller than that for $TiO_2$/UV system due to competitive adsorption between organics and ozone.

• Journal of Wetlands Research
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• v.17 no.1
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• pp.1-10
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• 2015

The bleaching phenomenon of otter spraints is indicates that the age of spraints (fresh or old spraints). As previous studies on the old otter faeces (spraint) have focused only on the external changes of spraints, it has been difficult to explain the difference of the decomposition rates among old spraints. We hypothesized that the micrometeorology difference caused by various characteristics of sprainting sites such as porosity and consistency of soil could affect the extent of the decomposition rate, the solar bleaching phenomenon of spraints used as a measure of the patterns of old spraints. Sprainting sites were classified into four types (Clay, Sand, Rock and Concrete spot) and each type was divided into two groups according to the sunlight condition (Sunny site and Shady site) to measure the effect of solar radiation. Micrometeorology of the sites were evaluated by measuring temperatures and humidities of the sites during the whole season. The variations in micrometeorology of the sunny sites according to the sprainting site types were examined with correlation analyses between the factors of micrometeorology. The analyses on the bleaching phenomenon of the spraints by micrometeorology showed that the highest rate of bleaching was found at the 'Rock spot' and 'Concrete spot' of the sunny site and especially in summer, the highest rate of bleaching ($63.4{\pm}7.6%$) was found at the 'Clay spot' of the sunny sites. The lowest rate of bleaching was found at the 'Sand spot' of the sunny sites. The above findings show that the difference in bleaching rates among sprainting sites was due to the seasonal or sunny condition. In addition, we found that the differences in thermal conductivity among sprainting site characteristics have resulted in different sprainting site temperature which have affected the rate of bleaching of spraints. In conclusion, this study suggests that studies of otters on their population size and home ranges using spraints as an indirect sign, should consider the effects of sprainting site characteristics and weather conditions.