One of the promising candidates for accident-tolerant fuel (ATF), a ceramic microcell fuel, which can be distinguished by an unusual cell-like microstructure (UO2 grain cell surrounded by a doped oxide cell wall), is being developed. This study deals with the microstructural observation of the constituent phases and the wetting behaviors of the cell wall materials in three kinds of ceramic microcell UO2 pellets: Si-Ti-O (STO), Si-Cr-O (SCO), and Al-Si-Ti-O (ASTO). The chemical and physical states of the cell wall materials are estimated by HSC Chemistry and confirmed by experiment to be mixtures of Si-O and Ti-O for the STO; Si-O and Cr-O for SCO; and Si-O, Ti-O, and Al-Si-O for the ASTO. From their morphology at triple junctions, UO2 grains appear to be wet by the Si-O or Al-Si-O rather than other oxides, providing a benefit on the capture-ability of the ceramic microcell cell wall. The wetting behavior can be explained by the relationships between the interface energy and the contact angle.

사고저항성 핵연료의 일환으로 UO2 입자가 세라믹 셀 벽으로 둘러싸인 미세구조를 갖는 세라믹 미소셀 UO2 소결체를 개발 중이다. 이는 핵분열생성물들을 UO2 펠렛 내에 포집하여 펠렛 외부로의 방출을 저감함으로써 봉내압 상승을 완화하고 응력부식균열 발생률을 낮춘다. 생성량이나 방사능 측면에서 위험한 핵분열생성물 중 하나로 여겨지는 세슘은 세라믹 미소셀 소결체 내에서 셀 물질과 화학반응 하여 포집될 수 있다. 따라서, 세슘 포집능은 해당 화학반응의 열역학적, 속도론적 특성에 의해 결정된다. 역으로, 미소셀 소결체의 조성설계 시 해당 반응에 대한 열역학적 예측이 필수적이다. 본 연구는 세라믹 현재 개발 중인 여러 미소셀 조성(Si-Ti-O, Si-Cr-O, Si-Al-O)에 대해 세슘의 포집능을 평가하는 열역학적 계산을 다룬다. 계 산에 앞서 먼저 HSC Chemistry를 이용해 세슘과 셀 물질의 물리/화학적 상태를 정의한 후, LWR 정상운전 모사환경에서 계 산된 세슘포텐셜(ΔGCs)과 산소포텐셜(ΔG02)에 근거하여 세슘포집 반응성을 평가하였다. 계산 결과에 근거하면, 세슘 포집 반응은 상기 모든 조성에서 자발적일 것으로 예상되며 이로써 조성설계의 근거를 제시함과 동시에 세슘의 포집능을 평가하는 효과적인 방법을 제공한다.

Graphite was diffusion-bonded by hot-pressing to W-25Re alloy using a Ti interlayer. For the joining, a uniaxial pressure of 25 MPa was applied at 1600 oC for 2 hrs in an argon atmosphere with a heating rate of 10 oC min−1. The interfacial microstructure and elemental distribution of the W-25Re/Ti/Graphite joints were analyzed by scanning electron microscopy (SEM). Hot-pressed joints appeared to form a stable interlayer without any micro-cracking, pores, or defects. To investigate the high-temperature stability of the W-25Re/Ti/Graphite joint, an oxy-acetylene torch test was conducted for 30 seconds with oxygen and acetylene at a 1.3:1 ratio. Cross-sectional analysis of the joint was performed to compare the thickness of the oxide layer and its chemical composition. The thickness of W-25Re changed from 250 to 20 μm. In the elemental analysis, a high fraction of rhenium was detected at the surface oxidation layer of W-25Re, while the W-25Re matrix was found to maintain the initial weight ratio. Tungsten was first reacted with oxygen at a torch temperature over 2500 oC to form a tungsten oxide layer on the surface of W-25Re. Then, the remaining rhenium was subsequently reacted with oxygen to form rhenium oxide. The interfacial microstructure of the Ti-containing interlayer was stable after the torch test at a temperature over 2500 oC.

Cryopreservation of avian semen is a useful tool to preserve genetic resource for aim of preventing extinction induced by infectious disease like avian influenza. Unlike those of mammals, data from chicken cryopreserved semen has not been showed feasible results. So, various cryoprotectants and diluents have been examined in many methods. In this report, as a major ingredient of avian seminal plasm, glutamine was substituted by alanyl glutamine to enhance physiological stability of chicken semen during freezing. We studied effect of glycerol and Dimethylacetamide(DMA) on motility and progressive motility of spermatozoa using glutamine diluent(EK-G) or alanyl glutamine diluent(EK-A) condition. The semen of Ogye was collected twice a week by the dorso-abdominimal massage method and diluted with same volume of EK-G or EK-A at 25℃ and stored for 10 min at 4℃ in cold chamber. Glycerol or DMA was added to diluted semen to reached 7% of final concentration at 4℃. After 3min of equilibration, the diluted semen was packed into 0.25ml straws and subjected to cryopreservation used freezing equipment. The packed straw were placed on height 5 cm above surface of liquid nitrogen(LN2) and held for 10min. After preserved for 2 weeks, the straw was thawed onto the 4℃ cooling bath. The images of motility and progressive motility spermatozoa were recorded by digital image recorder and analyzed by manual. The results showed 68.5% motility and 34.1% progressive motility in DMA/EKA diluent, 31.45% and 17.6% in glycerol/EKA, 45.4% and 8.6% in DMA/EKG, and 9.7% and 6.4% in glycerol/EKG. With these results, the alanyl glutamine and DMA could be used as a main composition of diluent and cryoprotectant for cryopreservation of chicken semen.

The cottony cushion scale, Icerya purchasi Maskell (Hemiptera: Margarodidae), is a destructive pest on citrus. This study was conducted to obtain the stage-specific phenology of I.purchasi for use in field application. The crawlers (hatched nymphs) from the egg sac of overwintered female began to move from late May and peaked in early to mid-June with most crawlers completed the movement till late June. The 1st nymph population peaked in mid June in 1stgeneration and early October in 2ndgeneration. The 2nd nymphs showed peak activity in late July and late October during the 1st and 2nd generation, respectively. The 3rd nymphs peaked in early September in 1st generation, while it kept a plateau without forming a peak after mid October in 2nd generation. The 1st generation adults peaked in mid September, and the tail was overlapped with 2nd generation adult population. Consequently, two life cycles were competed in Jeju area. An average of 20.7% of citrus orchards was infested with I. purchasi with a 3.9% of mean infested trees in Jeju. The present results should be useful in establishing management strategies for I. purchasi in citrus orchards.

Background : The effective components of Omija(Schisandra chinensis Bailllon) are lignans (schizandrins and gomisins), and this components were contented mostly in seed part on Omija, which have various physiological functionalities such as anti-cancer, anti-inflammatory, and antioxidant activities. Methods and Results : This study was carried out to determine effective condition(CO2, CO2+ethanol) on extraction using supercritical carbon dioxide extraction (SFE) system and to find interrelation on effective components and antioxidant activity of extracts and residues obtained after extraction. Effective components were analysed lignans and phenolic compounds and antioxidant activirty was determined for DPPH radical scavenging ability on methanol extracts of SFE-extract and SFE-residue. On SFE with ethanol, SFE extract was separated two phase, upper(water phase) and lower(oil phase). SFE-extract showed the highest total lignans content(61.36 mg/g, 72.14 mg/g on lower, 50.58 mg/g on upper) and the lowest total phenolic compounds(6.52 mg/100g) and SFE-residue showed the lowest total lignans content(1.45 mg/g) and the highest total phenolic compounds(16.23 mg/100g) by extracted on CO2+ethanol treatment. SFE-residue methanol extract showed the highest DPPH radical scavenging abilities and SFE-extract upper showed the lowest. Conclusion : Thus, this results showed SFE-extract showed the highest total lignans content, but SFE-residue showed the highest DPPH radical scavenging ability although the lowest total lignans content.

This paper provides a way for the expletive there to associate directly with its indefmite DP via Agree between their Sc` -features in narrow-syntactic derivation. It is claimed that in English, External Merge of there with _u[person] and _u[Case] features need to be allowed in the Spec of a weak v, where no θ-role is assigned to there and the there-argument link can be established by assuming that the _u[person] feature of there is valued via Agree with the φ-set of the associate DP. It is assumed that there and an indefinite DP are selected as a pair in the Sub-Lexical Array. A single θ-role and a unique Case value may thus be given to them. The single θ-role will be saturated as they merge into the weak vP and the unique Case value will be given to them via Multiple Agree with a higher T or v during the derivation. These are based on the assumption that Multiple Agree takes place sequentially, but not simultaneously, contra Chomsky (2001). Sequential application of Multiple Agree may contribute to rendering the computation purely derivational and remove the distinction of Multiple Agree from Agree.

Dongseok Kim. 2000. On the EPP-Feature of T. Studies in Modern Grammar 22, 125-144. In this paper, we argue that defective T is devoid of EPP-feature, and that the weak expletive there bears Case feature. On the observation that the target of Move or Merge for the purpose of satisfying the EPP of T is invariably a Case marked position, we propose to reduce the EPP-feature to Case checking requirement. The proposed analysis has advantages of eliminating the Merge over Move Preference and redundancy in EPP and Case checking.

Dongseok Kim. 1999. Cyclicity in A-Movement. Studies in Modern Grammar 18, 21-37. In this paper, we examine operations that eliminate uninterpretable features in the recent version of the Minimalist Program presented in Chomsky (1998), and propose that defective T lacks EPP feature, contrary to Chomsky`s assumption. It is shown that if defective T is given EPP feature, problems arise in deleting ψ -feature of defective infinitival T in expletive raising constructions, since ψ -feature of expletive there, being defective, is not capable of deleting the probe. Reviewing arguments for SPEC position of infinitival T, we show that EPP feature is not forced or necessary for tenseless T. Thus, we suggest that there is no successive cyclic A-movement through SPEC of defective T.

Kim Dongseok. 1998. Distribution and Licensing of Null Subjects. Studies in Modern Grammar 14, 85-105. The primary aim of this paper is to examine the distribution and the status of null subjects, and to reduce the pro-drop parameter to the feature checking mechanism of the minimalist program presented in Chomsky(1993, 1995). We have demonstrated that if there is a topic, it becomes the first candidate to be the antecedent of the null argument; otherwise the null argument is controlled by a c-commanding argument. The difference between Italian and Korean in the possibility of null arguments getting their reference from the discourse context is explained by the availability of the D-morpheme proposed in Moon(1989). And the pro-drop parameter is analysed in terms of feature checking under the hypothesis that the EPP-feature is weak in pro-drop languages, whereas it is strong in non-pro-drop languages.

Dongseok Kim. 1998. Feature Checking in CP and the That-t Effect. Studies in Modern Grammatical Theories 12, 83-102. This paper briefly reviews the ECP and the minimalist theoretic accounts of the that-t effect, and proposes that the that-t effect together with the adverb effect can be adequately explained with the assumption that the [+Q]-feature of the subject wh-phrase is directly attracted by the strong [+Q]-feature of C(i.e. the complementary categorial feature of C) whereas the wh-phrase moves through the [SPEC, CP] of the embedded clauses, if any. In the analysis proposed in this paper, that; if, etc., which have been taken to be complementizers, are reanalyzed as C-checkers, and the that-t effect is captured by the Case checking mechanism in CP. Under the hypothesis that the subject wh-phrase moves from the vP-internal position to [SPEC, CP] for Case feature checking the that-t effect appears when the [-Q]-feature of C is checked by a C-checker with phonological features which do not permit T-to-C raising. The account on this track has the advantage, over the existing analyses, of reducing the chain formed by movement of a wh-subject to a uniform A´-chain, and taking complementizers to be null categories in conformity with the other functional categories such as T, v, etc.

Kim Dongseok. 1997. Case Checking in Double Object Construction. Studies in Modern Grammatical Theories 10: 21-96. This paper critically reviews Larson`s(1988) and Fujita`s(1996) analyses of double object construction, and proposes an alternative one that can effectively explain the asymmetries shown in dative and double object constructions. The major contents are summarized as follows: (a) In dative construction the argument assigned the role of Goal is not a complement of V but an argument merged with V`. (b) The thematic role of indirect object in double object construction is different from that of dative construction. The former assumes Benefactive or Affective, while the latter, Goal. (c) The verb in dative construction and the corresponding one in double object construction are separate lexical items that have the same phonological features but are different in their semantic and formal features. The former selects Theme and Goal as its internal arguments while the latter selects Theme and Benefactive, Experiencer or Affective. (d) The difference in thematic interpretation of the subjects in dative and double object constructions is not from the syntactic relation but from the difference in the properties of semantic selection of the verbs. (e) Indirect object of double object construction moves to the SPEC of V to satisfy the [+SPEC] feature of V. The movement is not for Case assignment or checking of Case feature.

Kim, Doug-seok. 1996. Island Constraints on Attract-F. Studies in Modern Grammatical Theories 8: 129-151. Chomsky`s(1995) definition of Attract-F comprises the effects of the MLC and Last Resort. However, the CED, which is not reducible to the Shortest Movement Condition, is not incorporated in the definition. As a result, Attract-F itself cannot block illegitimate extractions out of islands such as subject, adjunct; and complex NP. To include the island constraints in the definition of Attract-F this paper captures the common properties of the islands in terms of c-command relation between a head and the category contained in the projection of the head, and proposes a revised definition of Attract-F: K attracts F if (i) F is the closest feature that can enter into a checking relation with a sublabel of K, and (ii) these is no X, X a head, such that a projection of X contains a maximal projection YP dominating a category with F and X does not c-command YP. The first part of this definition comprises the effects of the MLC and Last Resort and the second part incorporates the effects of the island constraints.