• Nuclear Engineering and Technology
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• v.55 no.7
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• pp.2687-2696
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• 2023

The fuel operating ranges of fusion tokamak-based power plants are estimated using the improved engineering breakeven equation. The Lawson criterion equations are derived in the form of a triple product with a focus on engineering breakeven and the subbreakeven operating range. The relationship of fuel parameters to the power plant net efficiency is outlined. Analysis shows that the operating ranges of the suitable fuel parameters form a closed area, the size of which affects the net efficiency of the power plant. The obtained fuel operating ranges confirm the well-known fact that DT fuel is currently the only fusion fuel useable in tokamak-based fusion power plants. It is also shown that the energy utilization of pB fuel is possible in the subbreakeven operating range but is conditioned by the very high efficiency of the power plant equipment. For the utilization of DD, DHe3, and pB fuels, the required magnetic fields are indicatively estimated.

• The Korean Journal of Ecology
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• v.27 no.2
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• pp.79-86
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• 2004

An extensive study of the vegetation characteristics of the Hamersley Ranges, a mountainous desert area of north-west Australia, facilitated the comparison of plant species diversity measures with mountainous deserts of other parts of the world. Alpha diversity was defined as the number of species co-existing at local scales and was found to average 18 species per 0.1 ha for the Hamersley Ranges. This was found to be similar to seven other mountainous deserts in North and South America, and southern Africa. Variation in alpha diversity between these deserts was found to considerably lower than within deserts, suggesting that local processes control species richness at local scales. Beta diversity, defined here as turnover in species composition at various spatial scales, can be measured in many ways. For the Hamersley Ranges, Wilson's β ranged from 1.2 to 1.6 for five sites along a topographic gradient, whereas Whittaker's β between different plant communities was found to average 0.93. Comparable data was not found for other desert areas, but comparisons to non-desert areas suggest beta diversity within landscapes is relatively high and is likely to reflect the considerable landform heterogeneity of the Hamersley Ranges. 55∼70% of species were shared between different landscapes of the Hamersley Ranges; comparisons to other regions suggest beta diversity at this scale is relatively low. Gamma diversity, the number of species over large spatial extents, was successfully compared using regression analysis of the log-log species - area relationship. This revealed that the northern Sonoran desert has significantly less species than the Nama (inland) Karoo and Hamersley Ranges over medium spatial extents, but species numbers were similar at a regional scale. Several constraints to the valid comparison of species diversity were identified, including lack of standardisation of sampling techniques, the wide range of measures employed, general lack of published data, and the influence of the various components of spatial scale on most diversity measures. Recommendations on how to improve future comparative work are provided.

• Journal of Ecology and Environment
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• v.38 no.2
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• pp.195-211
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• 2015

The objectives of this research were to determine mean and maximum tolerance ranges of Carassius auratus ($C_a$) and Cyprinus carpio ($C_c$) populations on various physico-chemical parameters and ecological indicator metrics. Little is known about chemical tolerance ranges of the two species, even though these species are widely distributed species in aquatic ecosystems. Maximum tolerance ranges of $C_a$-population to total nitrogen (TN) and total phosphorus (TP) were $20.3mgL^{-1}$ and $2.0mgL^{-1}$, respectively. Optimal ranges of TN and TP in the $C_a$-population were $1.7-5.0mgL^{-1}$ and $0.06-0.30mgL^{-1}$, respectively. Such nutrient regimes of the $C_a$-population were evaluated as hypereutrophy, indicating high tolerance limits. The $C_c$-population had similar ecological characteristics to $C_a$-population, but the mean tolerance ranges of TN, TP, BOD, and COD were significantly (p < 0.05) greater than the $C_a$-population. Ecological patterns of trophic composition and tolerance guilds in the $C_a$-population were similar to those of the $C_c$-population. The model value of Index of Biological Integrity (IBI) of the habitat where C. auratus and C. carpio co-occurred averaged $15.0{\pm}4.3$ and $12.9{\pm}3.6$, respectively. Based on the modified criteria of the United States Environmental Protection Agency (Klemm et al. 1993), it indicated poor ecological health of both species. These results suggest that both species are highly tolerant to chemical and physical habitat conditions of waterbodies, and that the chemical tolerance range of $C_c$-population was higher than $C_a$-population.

• Journal of the Korean Applied Science and Technology
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• v.36 no.4
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• pp.1119-1127
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• 2019

This study analyzes the content of niacin, B1, and B2, which are among the water-soluble vitamin B group, in cultivars of the commonly consumed agricultural products of apples, peaches, nectarines and strawberries to compare content differences and to use results as base material for the Korean Food Composition Table. While the vitamin B1 content of apples according to different cultivars was found to be within the ranges of 0.063-0.208 mg/100g, and the content of vitamin B2 was found to be within the value ranges of 0.006-0.031 mg/100g, no niacin was found. The vitamin B1 content of peaches and nectarines according to different cultivars was found to be within the value ranges of 0.014-0.276 mg/100g, the content of vitamin B2 was found to be within he value ranges of 0.019-0.042 mg/100g, and niacin content was found to be within the value ranges of 0.298-1.096 mg/100g. The vitamin B1 content of strawberries according to cultivars was found to be within the value ranges of 0.112-0.394 mg/100g, the content of vitamin B2 was found to within the value ranges of 0.001-0.027 mg/100g, and niacin content was found to be within the value ranges of 0.388-0.809 mg/100g. Therefore, when nutrient composition analysis databases for the fruits of apples, peaches, and strawberries are constructed, cultivar factors must be put into consideration. In addition, differences can be found according to fruit harvest times, cultivation methods, and environmental factors, so related additional is needed.

• Journal of Soil and Groundwater Environment
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• v.20 no.6
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• pp.8-18
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• 2015

Pollutants such as heavy metals and explosives originating from the military operational ranges can be migrated to adjacent surface water body or offsite soil, and can affect to local residents and aquatic ecosystem. Therefore, Korea Ministry of the National Defense has established various guidelines for environmental management including the installation of pollutant migration prevention facilities (PMPFs) and monitoring methodologies for heavy metals in the operational range soil and effluent and sediment of PMPFs. However, current guidelines neither address the explosive compounds such as 2, 4, 6-trinitrotoluene (TNT) and hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) nor suggest detailed environmental investigation protocol. This paper introduces the new “Environmental Management Manual for Military Firing Ranges”, which includes the environmental criteria for explosives as well as the detailed investigation protocol for the affected environmental media including soil, effluent and sediment of PMPFs.

• The Journal of the Acoustical Society of Korea
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• v.21 no.2E
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• pp.81-90
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• 2002

Single absorbing materials and Helmholtz resonators have limited absorption characteristics over limited frequency ranges due to their structures and properties. Porous materials are highly absorptive for mid and high frequency ranges, while they have little sound absorption for low frequency sounds. Helmholtz resonators are generally used to absorb sound energy for a specified frequency range. Hence they have limited capability in controlling the overall acoustic properties of a space. Not much has been known about useful finishing materials which have enough rigidity and absorption over broad frequency range, in spite of wide demands from acoustic designers and consultants. The present work measured and analyzed absorption characteristics of a slit absorber by varying surface materials, depths of air gap, dimensions of slat and slit widths. It was found that the narrower the slit width, the larger the absorptions over the wide frequency ranges and the pattern was dependent on the presence of porous material. Narrower slat's width tend to increase the slit absorber's absorption more or less. Absorption coefficients at low frequency ranges were dramatically improved (from 0.23 to 0.56) by increasing air gap when porous materials were present.

• Journal of Forest and Environmental Science
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• v.32 no.4
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• pp.377-383
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• 2016

We obtained a total of 36 GPS coordinates of the seven bat species of Rhinolophus ferrumequinum, Myotis ikonnikovi, M. nattereri, M. petax, Murina ussuriensis, Plecotus auritus, and Pipistrellus abramus. Characteristics of forests (forest type, age class, DBH class and crown density), terrain (aspect, slope and distance from mountain stream) and disturbance factors (distance from human residential areas and distance from cultivated areas) that bats have used as their habitats were revealed from the GIS analysis based on GPS coordinates of the 36 positions that bats were found. The bats-preferred forest type is broad-leaf forests (43%) with the trees of the 2th (31%) and 5th (31%) age class, the trees of sapling (36%) and large DBH class (31%), and sparse crown density (67%). Bats prefer the slop direction of the east (39%), the gradient below $15^{\circ}$ (61%), the ranges within 200 m from the mountain streams (92%), the ranges within 200 m near roads (89%), the ranges of 200-400 m from human residential areas (28%), and the ranges within 200 m from cultivated areas (36%).

• Environmental Analysis Health and Toxicology
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• v.10 no.1_2
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• pp.47-54
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• 1995

To investigate and evaluated the scavenging and antioxidative effects of various flavonoids on paraquat induced toxicity, in vivo and vitro tests of eight flavonoids (catechin, epocatechin, flavone, chrysin, apigenin, quercetin, morin and biochanin A) were carried out. The generation of reactive oxygen substances(ROS) in PMS-NADH system $H_2O_2$ induced hemolysis and lipidperoxidation to blood, NADPH dependent lipidperoxidation to liver and lung microsome by paraquat were studied.The results are summerized as follows; 1) In the concentration ranges from 3.3 to 9.8$\mu$M of catechin,epicatechin, quercetin and biochanin A removed the 50% of DPPH radical scavenging effects. 2) In the concentration ranges from 0.60 to 1.86 mM of catechin, epicatechin, quercetin and biochanin A showed the inhibitory and antioxidative activity on superoxide anion which gernerated in PMA-NADH system. 3) In the concentration ranges from 0.12 to 0.49mM of catechin, epicatechin, quercetin and biochanin A showed the inhibitory and antioxidative activity on H202 which generated in PMA-NADH system. 4) In the concentration ranges from 0.6 x10$^{-5}$ to 6.3 x 10$^{-5}$mM of catechin, epicatechin, flavone, chrysin, quercetin and morin showed the inhibitory and antioxidative activity on $H_2O_2$ induced hemolysis to blood 5) All flavonoids tested exhibited inhibitory and antioxidative effects on paraquat induced liver and tung microsomal lipidperoxidation. Therefore, all flavonoids evaluated showed the useful compounds for scavenger and antioxidant on paraquat induced toxicity.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.15 no.9
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• pp.738-743
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• 2003

In the present study, the heating and cooling characteristics of system air-conditioner using a PWM compressor or a BLDC inverter compressor are investigated by the psychometric calorimeter using air enthalpy method. Cooling and heating capacities, power inputs and COPs are measured at the low, moderate, high loads under the cooling and heating standard conditions. At cooling conditions, the capacity of the PWM system is larger than that of the inverter case. Due to large power input, however, low COPs are measured under total load ranges. At heating conditions, the capacity of the PWM method is a little larger than that of the inverter case, except high load range. Since power input is low, large COPs are measured at moderate and high load ranges, which are different from cooling data. This shows that the PW system compared with the inverter case has good energy consumption efficiency at moderate and high load ranges except low load range. And when the system A/C is operated under the cooling and heating standard conditions, COPs are nearly uniform at total load ranges.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.24 no.1
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• pp.74-78
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• 2014

Objectives: Purpose of this study was to evaluate the noise level exposures at the different cannonball type and locations in the tank gun drill ranges. Methods: We visited the tank gun drill ranges and measured with a sound level meter(3M Quest SoundPro$^{TM}$) with the value of Peak(dB(A)). Results: The highest peak value of impulse noise level averaged 166.3 dB(A) at the site of loading solider. The highest peak value of impulse noise level by size of cannonball averaged 165.9 dB(A) at the 120 mm size cannonball of the tank. This result was significantly different from the other size of cannonballs such as 7.62 mm, 90 mm, and 105 mm(p < 0.001). Among the four types of soldier site on the tank, average noise levels of loading soldier, 156.6 dB(A), were higher than the other three types of soldier site (p > 0.05). Conclusions: This study confirmed that there were needed for a proper control to reduce the amount of impulse noise exposure at the tank gun drill ranges.