• The Korean Journal of Mycology
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• v.38 no.2
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• pp.112-119
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• 2010

Pleurotus spp. have been used for edible and medicinal purposes in Asian countries for a long time. The fruiting bodies of the Pleurotus ostreatus, Pleurotus citrinopileatus and Pleurotus salmoneostramineus contained many physiologically beneficial substances for human health. Therefore, it is necessary to study the genetic diversity of Pleurotus mushroom cultivars commercially cultivated in Korea. Eleven strains of Pleurotus spp. were collected from different geographical regions in South-East Asia and ITS regions of rDNA and RAPD of genomic DNA were analyzed. The size of the ITS1 and ITS2 regions of rDNA from the different strains varied from 167 to 254 bp and 156 to 213 bp, respectively. The sequence of ITS1 was more variable than that of ITS2, and the 5.8S sequences were identical. A phylogenetic tree based on the ITS region sequences indicated that selected strains could be classified into 4 clusters. Eleven Pleurotus species were also analyzed by RAPD with 20 arbitrary primers. Ten of these primers were efficiently amplified the genomic DNA. The number of amplified bands varied with the primers and strains, with polymorphic fragments in the range from 0.1 to 2.0kb. The results revealed that genetic diversity of selected strains of P. ostreatus, P. citrinopileatus and P. salmoneostramineus is low.

• Childhood Kidney Diseases
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• v.17 no.2
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• pp.101-109
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• 2013

Purpose: Pediatric urolithiasis is uncommon in children but is a cause of significant morbidity and damage to the kidney. Although much information on adult urolithiasis is available in the literature, large studies on the pediatric population are still scarce. In this report, we review our experience with pediatric urolithiasis over 22 years at a tertiary referral center. Method: We retrospectively reviewed the records of children with newly diagnosed urolithiasis between January 1991 and May 2013. We assessed the age, sex, family history, initial symptoms, location of stones, underlying cause, stone analysis, treatment, and recurrence among the patients. Results: In total, 137 patients (96 male, 41 female) were assessed. The age range was 0-17 years (mean age, 6.0 years). Forty-three (31%) children were aged <1 year, and 37% (16/43) had a history of intensive care unit (ICU) admission. Thirteen patients (9.5%) had a family history of stones. The most common symptoms at presentation among the patients were gross hematuria (56/137, 41%) and flank or abdominal pain (46/137, 34%). The stones were located in the kidney (85/137, 62%), ureter (29/137, 21%), bladder (2/137, 1.4%), and multiple locations (20/137, 15 %). Congenital abnormalities of the genitourinary (G-U) tract, with or without metabolic abnormality, or urinary tract infection (UTI) was detected in 26 children (19%). Ninety-one patients (66%) underwent metabolic examination, and 38% of these patients exhibited an abnormality. UTI, with or without abnormalities of the G-U tract, or metabolic abnormality was detected in 26 children (19%). Of the 35 stones analyzed, the majority were calcium stones (20/35, 57%), followed by infected stones (5/35, 14%), uric acid stones (4/35, 11%), carbonate apatite stones (3/35, 7%), cystine stones (2/35, 6%), and phosphate stones (1/35, 3%). Five patients (4%) required open procedures, with or without non-open procedures, whereas 77 patients (56%) were managed conservatively; the remaining 55 patients (40%) received some other form of intervention. Eighteen patients (13%) had stone recurrence during the follow-up period. Conclusions: Pediatric urolithiasis is commonly associated with abnormalities of the G-U tract and/or metabolic disorders and/or UTI. Half of the patients will pass their stones spontaneously, and all the techniques of minimally invasive surgery are applicable in the treatment of children with stones. As the recurrence rates are high among this population, long-term follow-up is recommended and the complete clearance of stones is important.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.17 no.2
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• pp.93-103
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• 1981

It is well-known that nowadays heat resisting and anti-corrosive materials have been widely used as the components materials of gas turbines, nuclear power plants and engines etc. In the fields of machine production industry. And materials for engine components, like as the exhaust valve of internal combustion engine, have been required to operate under the high temperature range of $700^{\circ}C$-$800^{\circ}C$ and high pressured gas with repeated mechanical load for the high performance of engines. For these components, friction welding for bonding of dissimilar steels can be applied for in order to obtain process shortening, production cost reduction and excellent bonding quality. And age hardening recently has been noticed to the heat resisting materials for further strengthening of high temperature strength, especially high temperature fatigue strength. However, it is difficult to find out any report concerning the effects of age hardening for strengthening high temperature fatigue strength to the Friction welded heat resisting and anti-corrosive materials. In this study the experiment was carried out as the high temperature rotary bending fatigue testing under the condition of $700^{\circ}C$ high temperature to the friction welded domestic heat resisting steels, SUH3-SUS303, which were 10hr., 100hr. aging heat treated at $700^{\circ}C$ after solution treatment 1hr. at $1, 060^{\circ}C$ for the purpose of observing the effects of the high temperature fatigue strength and fatigue fracture behaviors as well as with various mechanical properties of welded joints. The results obtained are summarized as follows: 1) Through mechanical tests and micro-structural examinations, the determined optimum welding conditions, rotating speed 2420 rpm, heating pressure 8kg/mm super(2), upsetting pressure 22kg/mm super(2), the amount of total upset 7mm (heating time 3 sec and upsetting time 2 sec) were satisfied. 2) The solution treated material SUH 3, SUS 303, have the highest inclination gradient on S-N curve due to the high temperature fatigue testing for long time at $700^{\circ}C$. 3) The optimum aging time of friction welded SUH3-SUS 303, has been recognized near the 10hr. at $700^{\circ}C$ after the solution treatment of 1hr. at $1, 060^{\circ}C$. 4) The high temperature fatigue limits of aging treated materials were compared with those of raw material according to the extender of aging time, on 10hr. aging, fatigue limits were increased by SUH 3 75.4%, SUS 303 28.5%, friction welded joints SUH 3-SUS 303 44.2% and 100hr. aging the rates were 64.9%, 30.4% and 36.6% respectively. 5) The fatigue fractures occurred at the side of the base matal SUS303 of the friction welded joints SUH 3-SUS 303 and it is difficult to find out fractures at the friction welding interfaces. 6) The cracking mode of SUS 303, SUH 3-303 is intergranular in any case, but SUH 3 is fractured by transgranular cracking.

• Korean Journal of Plant Taxonomy
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• v.34 no.3
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• pp.221-244
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• 2004

Prunus sargentii complex of subgenus Cerasus is an Eastem Asiatic plant group that exhibits a broad range of morphological variation and includes P. takesimensis, P. yedosensis, P. verecunda, and P. sargentii. In this study, a morphological analysis was undertaken to determine whether the observed morphological variation was primarily attributable to morphological discontinuities among the taxa. P. sargentii, which distributed eastem area in Korea, northern area in Japan and far east Russia had umbel like inflorescence and additionally was characterized by sticky bud and leaf twigs, compared with P. serrulata complex. Also, P. verecunda in Korea and Japan was characterized by umbel like inflorescence and presence of hair in leaf, petiole and pedicel, and was treated as a variety of P. sargentii. Evidence obtained from multivariate morphometric analyses indicated that the entity of P. takesimensis formed a cohesive group somewhat distinct from P. sargenti.. Especially, P. takesimensis was characterized by relatively small flowers (26-32mm in diameter) and many flowers [(2)3-5] per umbel inflorescence, compared with P. sargentii (34-48mm and 2(3) per inflorescence) and should be recognized as an independent and endeImic taxon in Korea. Additionally, P. yedosensis, which was known to have umbel inflorescence (short peduncle type) with pubescent style based on the type specimen, was comprised of corymb inflorescence (long peduncle type) as well. The morphological differentiation between these two types of P. yedosensis was not considered sufficient to warrant recognition of specific status because of the putative hybrid origin, no distinctive geographical distribution pattern, and existence of various peduncle length on Island Jeju-do of Korea.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.31 no.4 s.54
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• pp.289-293
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• 2005

Nowadays there are many sun protection cosmetics including organic or inorganic UV filter as an active ingredient. Chemically stable inorganic sunsEreen agents, usually metal oxides, we widely employed in high SPF products. Titanium dioxide is one of the most frequently used inorganic UV filters. It has been used as pigments for a long period of cosmetic history. With the development of micronization techniques, it becomes possible to incorporate titanium dioxide in sunscreen formulations without whitening effect and it becomes an important research topic. However, there are very few works related to quantitations of titanium dioxide in sunscreen products. In this research, we analyzed amounts of titanium dioxide in sunscreen cosmetics by adapting redof titration, reduction of Ti(IV) to Ti(III) and reoxidation to Ti(IV). After calcification of other organic ingredients of cosmetics, titanium dioxide is dissolved by hot sulfuric acid. The dissolved Ti(IV) is reduced to the Ti(III) by adding aluminum metals. The reduced Ti(III) is titrated against a standard oxidizing agent, Fe(III) (ammonium iron(III) sulfate), with potassium thiocyanate as an indicator In order to test accuracy and applicability of the proposed method, we analyzed the amounts of titanium dioxide in four types of sunscreen cosmetics, such as cream, make-up base, foundation and powder, after adding known amounts of titanium dioxide $(1{\sim}25w/w%)$. The percent recoveries of the titanium dioxide in four types of formulations were in the range between 96 and 105%. We also analyzed 7 commercial cosmetic products labeled titanium dioxide as an ingredient and compared the results with those of obtained from ICP-AES (Inductively Coupled Plasma-Atomic Emission Spectrometry), one of the most powerful atomic analysis techniques. The results showed that the titrated amounts were well coincided with the analyzed amounts of titanium dioxide by ICP-AES. Although instrumental analytical methods, ICP-MS (Inductively Coupled Plasma-Mass Spectrometry) and ICP-AES, are the best for the analysis of titanium, it is hard to adopt because of their high prices for small cosmetic companies. It was found that the volumetric method presented here gat e quantitative and reliable results with routine lab-wares and chemicals.

• Clean Technology
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• v.25 no.1
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• pp.81-90
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• 2019

A dielectric barrier discharge (DBD) plasma reactor packed with $Ni-CeO_2/{\gamma}-Al_2O_3$ catalyst was used for the dry ($CO_2$) reforming of propane (DRP) to improve the production of syngas (a mixture of $H_2$ and CO) and the catalyst stability. The plasma-catalytic DRP was carried out with either thermally or plasma-reduced $Ni-CeO_2/{\gamma}-Al_2O_3$ catalyst at a $C_3H_8/CO_2$ ratio of 1/3 and a total feed gas flow rate of $300mL\;min^{-1}$. The catalytic activities associated with the DRP were evaluated in the range of $500{\sim}600^{\circ}C$. Following the calcination in ambient air, the ${\gamma}-Al_2O_3$ impregnated with the precursor solution ($Ni(NO_3)_2$ and $Ce(NO_3)_2$) was subjected to reduction in an $H_2/Ar$ atmosphere to prepare $Ni-CeO_2/{\gamma}-Al_2O_3$ catalyst. The characteristics of the catalysts were examined using X-ray diffraction (XRD), transmission electron microscopy (TEM), field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectrometry (EDS), temperature programmed reduction ($H_2-TPR$), temperature programmed desorption ($H_2-TPD$, $CO_2-TPD$), temperature programmed oxidation (TPO), and Raman spectroscopy. The investigation revealed that the plasma-reduced $Ni-CeO_2/{\gamma}-Al_2O_3$ catalyst exhibited superior catalytic activity for the production of syngas, compared to the thermally reduced catalyst. Besides, the plasma-reduced $Ni-CeO_2/{\gamma}-Al_2O_3$ catalyst was found to show long-term catalytic stability with respect to coke resistance that is main concern regarding the DRP process.

• Korean Journal of Environment and Ecology
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• v.33 no.3
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• pp.266-279
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• 2019

We investigated the characteristics of fish communities and habitat status of endangered species Rhodeus pseudosericeus in Heuk Stream, a tributary of the Han River, from April to October 2018. During this period, we collected 47 species of 14 families from 10 survey stations using kick nets, cast nets, and long bag set nets. The dominant and subdominant species were Zacco platypus (37.6%) and Z. koreanus (13.8%), respectively. The next most abundant species were Squalidus gracilis majimae (11.1%), Pungtungia herzi (7.7%), Rhodeus pseudosericeus (5.0%), Microphysogobio yaluensis (4.3%), and Hemibarbus longirostris (3.0%). Among the fish collected, 19 species (40.4%) were Korean endemic species. Endangered species were R. pseudosericeus and Acheilognathus signifer while exotic species were Micropterus salmoides and Oncorhynchus mykiss, and land-locked species were Plecoglossus altivelis and Rhinogobius brunneus. The community analysis showed that the dominance and evenness indexes were mostly low and that the diversity and richness indexes were high. Moreover, the river health (index of biological integrity) was mostly excllent (1 site is good, 9 sites are very good). R. pseudosericeus inhabited widely from St. 3 to St. 9 in Heuk Stream, and its population size was large. Age groups for R. pseudosericeus estimated by the frequency distribution of total length in spawning season (April) indicated the 32~45 mm group as 1-year old, the 46~59 mm group as 2-years old, 60~69 mm group as 3-years old, and the 70~89 mm group as 4-years or older. Total length range of male and female was similar, and the sex ratio of female (426) to male (394) was 1 : 0.95. A. signifer, which had been released in Heuk Stream, inhabited from St. 4 to St. 5, but its population size was small. Lastly, this paper discusses a conservation plan for fish in Heuk Stream.

• The Korean Journal of Air & Space Law and Policy
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• v.33 no.2
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• pp.169-197
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• 2018

The purpose of this study is to present a reasonable and concrete standard for the Korean aviation insurance compulsory subscription system. Through this, we aim to improve the current revision of laws and regulations, and ultimately create an environment in which the safety and property of the Korean people who use aircraft with appropriate aviation insurance can be secured. In particular, by reviewing the aviation business law and its new laws and regulations enacted in 2017, the legislative improvement direction of aviation insurance will be proposed. In order to maintain the continuous growth of the air transportation industry and to make amicable compensation for the victims, considering the characteristics of the total accident, instantness, and giganticness of air accidents in which a lot of people and property are lost in the event of an accident, adequate insurance coverage is essential. In this respect, the compulsory insurance to amend the principle of freedom of contract, which is the great principle of the modern judicial system, will be persuasive. However, in comparison with foreign legislation, the legal provisions on Korea's obligation to comply with aviation insurance need to be revised around the following issues: First, it is reasonable to enforce the regulation of the mandatory aviation insurance by legislation from the Congress not by administrative regulations. Because it will force the monetary obligations of the individual such as common air carriers. Second, our law regulations respond to various kinds of air damages by using the phrase "limit of liability stipulated in international conventions". However, as we have seen in the text, the range of compensation are various according to the use of legal instruments in international conventions such as the Montreal Convention, which governs the compensation of passengers for damages to passengers today. Third, in countries with narrow territories, such as Korea, there are big differences in flying time and insurable risk between domestic and international transportation. Therefore, it is necessary to divide domestic transportation and international transportation even in the obligation to join the insurance. This dual discipline has the advantage for rookies in air carrier market who mainly start their business from domestic service. Fourth, according to Korean law, the regulations of automobile loss insurance is applicable to the aviation mandatory insurance of unmanned aerial vehicle accident which is lack of persuasion. In the future, it will be appropriate to discipline insurance for unmanned aerial vehicles with unlimited potential for development from a long-term perspective.

• Journal of Legislation Research
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• no.55
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• pp.57-94
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• 2018

Crisis of trust in Korean society, especially south-south conflicts among Korean political circle, civil society and peoples on the issue of the Korean peninsula policy driven by south Korean government, have weakened the sustainable and consistent energy of the policy for peace and unification of Korea peninsula. At the moment of drastic change of south-north relation in Korean peninsula, National agreement as a foundation of sustainable peace and unification policy has very important meaning. Because of this, national contract of unification as a kind of social concertation, has been demanded. National contract for peace and unification is an unprecedented process for making unofficial legal norm because it authorize quasi-legislative binding force on the agreement which is concluded by the Korean political circle, civil society and peoples for the peace and unification of Korean peninsula. National contract for peace and unification includes 'agreed aim and principles' for peace, prosperity and unification as well as process and result. And National contract for peace and unification, also is characterized long duration of aim achievement and openness of participating subjects. In terms of law, it will be legitimate source for comprehensive modification of international and internal law. In addition, The nature of National contract for peace and unification, as a people's law, should be considered as soft law which has the power to realize its contents through the enactment of legislation and policy. In order to guarantee the establishment and effectiveness of National contract for peace and unification, the setting of organization is need to determine the range of representatives, who participate in the process of contract making, procedure of contract and to carry out the contract after the conclusion of National contract for peace and unification. For the reason, the Council of National Contract for Peace and Unification as a independent administrative government committee and 'Act on National Contract for Peace and Unification' is needed.

• Korean Journal of Agricultural and Forest Meteorology
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• v.22 no.4
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• pp.327-339
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• 2020

Transpiration is the movement of water into the atmosphere through leaf stomata of plant, and it accounts for more than half of evapotranspiration from the land surface. The measurements of transpiration could be conducted in various ways including eddy covariance and water balance method etc. However, the transpiration measurements of individual trees are necessary to quantify and compare the water use of each species and individual component within stands. For the measurement of the transpiration by individual tree, the thermometric methods such as heat dissipation and heat pulse methods are widely used. However, it is difficult and labor consuming to maintain the transpiration measurements of individual trees in a wide range area and especially for long-term experiment. Therefore, the sharing of sapflow data through database should be useful to promote the studies on transpiration and water balance for large spatial scale. In this paper, we present sap flow database, which have Granier type sap flux data from 18 Korean pine (Pinus koraiensis) since 2011 and 16 (Quercus aliena) since 2013 in Mt.Taehwa Seoul National University forest and 18 needle fir (Abies holophylla), seven (Quercus serrata), three (Carpinus laxiflora and C. cordata each since 2013 in Gwangneung. In addition, the database includes the sapling transpiration of nine species (Prunus sargentii, Larix kaempferii, Quercus accutisima, Pinus densiflora, Fraxinus rhynchophylla, Chamecypans obtuse, P. koraiensis, Betulla platyphylla, A. holophylla, Pinus thunbergii), which were measured using heat pulse method since 2018. We believe this is the first database to share the sapflux data in Rep. of Korea, and we wish our database to be used by other researchers and contribute a variety of researches in this field.