The leucine zipper (LZ) domain of the HY5 transcription factor from Arabidopsis thaliana has unique primary structural properties, including major occupation by the Leu residues as well as two buried polar residues in the a positions and a localized distribution of charged and polar residues in the first three heptad repeats. In this study, we solved the crystal structure of the HY5 LZ domain and show that the peculiarities in the primary sequence yield unusual structural characteristics. For example, the HY5 LZ domain exhibits a bipartite charge distribution characterized by a highly negative electrostatic surface potential in its N-terminal half and a nearly neutral potential in its C-terminal half. The LZ N-terminal region also contains two consecutive putative trigger sites for dimerization of the coiled coils. In addition, two buried asparagines at a positions 19 and 33 in the HY5 LZ domain display distinct modes of polar interaction. Whereas Asn 19 shows a conformational flip-flop, Asn 33 is engaged in a permanent hydrogen bond network. CD spectropolarimetry and analytical ultracentrifugation experiments performed with versions of the HY5 LZ domain containing mutations in the a positions yielded further evidence that position a amino acid residues are crucial for achieving an oligomeric state and maintaining stability. However, a low correlation between position a amino acid preference, core packing geometry, and rotamer conformations suggests that the oligomeric state of the LZ domain is not governed entirely by known structural properties. Taken together, our results suggest structural factors conferring conformational integrity of the HY5 LZ homodimer that are more complicated than proposed previously.A major challenge that faces protein chemists is the ability to predict the three-dimensional structures of proteins from their primary amino acid sequences. Because of its simplicity and periodicity, the coiled-coil motif is an ideal model system with which to investigate properties of the protein folding process. In terms of biological function, the coiled coil is one of the most common structural motifs and participates in many cellular processes through the formation of protein-protein interactions.Among coiled-coil proteins, the basic leucine zipper (bZIP) 3 proteins play crucial roles in the regulation of transcription. These proteins bind to their cognate DNA elements through their basic regions as they dimerize via their leucine zipper (LZ) domains. The LZ domain consists of an ␣-helix that contains a series of leucine residues on one face. Two LZ ␣-helices intertwine to produce a dimeric structure with a slight superhelical twist (1). The LZ domain consists of n heptad sequence repeats, designated (abcdefg) n (2), where positions a and d create the interface between two LZ strands by engaging in hydrophobic interactions, and positions e and g flank the dimer interface by forming electrostatic interactions. The various amino acid positions of the LZ heptad repeat have been shown to play unique role...

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This paper presents the magnetic field analysis of the racetrack double pancake field coil for the 10 MW class superconducting wind turbine which is considered to be the next generation of wind turbines using the 3 Dimensional FEM(Finite Elements Method). Generally, the racetrack-shaped field coil which is wound by the second generation(2G) superconducting wire in the longer axial direction is used, because the racetrack-shaped field coil generates the higher magnetic field density at the minimum size and reduces the synchronous reactance. To analysis the performance of the wind turbines, It is important to calculate the distribution of magnetic flux density at the straight parts and both end sections of the racetrack-shaped high temperature superconductivity(HTS) field coil. In addition, Lorentz force acting on the superconducting wire is calculated by the analysis of the magnetic field and it is important that through this way Lorentz force can be used as a parameter in the mechanical analysis which analyzes the mechanical stress on the racetrack-shaped field coil.

The Jeju Special Self-Governing Province is currently promoting the "Carbon-free Island by 2030" policy, which requires the use of renewable energy instead of fossil fuel so that the island will have no carbon gases generated by 2030. To implement this policy, the island plans to build a wind power plant capacity of 1.09 GW in 2020; this wind power plant is currently ongoing. However, when wind power output is greater than the power demand of the island, the stability of Jeju Island power system must be prepared for it because it can be a problem. Therefore, this study proposes a voltage source-type MMC-HVDC system linked to mainland Korea to expand the wind power penetration limits of Jeju Island under the stable operation of the Jeju Island power system. To verify the effectiveness of the proposed scheme, computer simulations using the PSCAD/EMTDC program are conducted, and the results are demonstrated. The scenarios of the computer simulation consist of two cases. First, the MMC-HVDC system is operated under variable wind power in the Jeju Island power system. Second, it is operated under the predicted Jeju Island power system in 2020.

td a t e:2 0 1 4 .6 .1 1 . ,J u d g me n td a t e:2 0 1 4 .6 .1 8 . ,P u b l i c a t i o nd e c i d ed a t e:2 0 1 4 .8 .2 5 . )Abstract : Th ef l u c t u a t i o no ft h eo u t p u tp o we ro fwi n df a r mswi l lb ea b l et oc a u s et h ei mp a c to nt h eJ e j up o we r s y s t e m s u c ha sp o we rq u a l i t ya n ds t a b i l i t y . Tos e t t l et h ema t t e r , ma n yr e s e a r c h e r sh a v ep r o p o s e dt h eu s eo ft h e BE S S ( Ba t t e r yE n e r g yS t o r a g eS y s t e m)i nt h ewi n df a r m. I nt h i sp a p e r , Th eBE S Si sa p p l i e dt oe a c hwi n df a r ms f o rmi t i g a t i n gt h ef l u c t u a t i o no fwi n dp o we ro u t p u t . Th eBE S S i sc o n t r o l l e df o rs mo o t h i n g t h eo u t p u to fwi n d f a r ms .Two k i n d so fs i mu l a t i o n wi l lb ec a r r i e d o u t .F i r s t ,t h es i mu l a t i o n r e s u l t sb y u s i n g P S C AD/ E MTDC s i mu l a t i o np r o g r a m a r ec o mp a r e dt ot h eme a s u r e dd a t af r o m t h er e a lpo we rg r i di nJ e j uI s l a n d .Th eo t h e ri st o a n a l y z et h eo u t p u to fwi n df a r mswh e nt h eBE S Si sa p p l i e dt ot h es i mu l a t i o nwo r k s . Th es i mu l a t i o nr e s u l t swi l l d e mo n s t r a t et h ee f f e c t i v e n e s so fu s i n gBE S S t os t a b i l i z ef o rp o we rg r i di nJ e j uI s l a n d .Key Words : 배터리에너지저장장치( Ba t t e r ye n e r g ys t o r a g es y s t e m) , 풍력( Wi n dp o we r ) , 잔존용량( S t a t eo fc h a r g e )