The Effects of MWD on the Rheological Properties of Shear-Induced Structural Formation for PVA Solutions in DMSO

Lee, Eun Jeoung,Kim, Byoung Chul WILEY-VCH Verlag 2007 Macromolecular symposia Vol.249 No.1

<P>The effects of molecular weight distribution (MWD) on the rheological responses of shear-induced structural formation in the general-purpose polyvinyl alcohol (PVA) solutions dissolved in dimethyl sulfoxide (DMSO) were investigated. On the whole, time-dependence of rheological properties was more influenced by the PVA solutions with broad MWD at the similar weight average molecular weight (M<SUB>w</SUB>). The dynamic viscosity (η′) of PVA/DMSO solution with broad MWD was lower than that with narrow MWD at the similar M<SUB>w</SUB> until the second time sweep (T2) of PVA/DMSO solution. After the time-sweep experiment was repeated, the η′ of PVA/DMSO solution with narrow MWD was lower than that of PVA/DMSO solution with broad MWD at the similar M<SUB>w</SUB>. The G′ until 5 min of relaxation of PVA/DMSO solution with broad MWD was lower than that of PVA/ DMSO solution with narrow MWD at the similar M<SUB>w</SUB>. After the time-sweep experiment was repeated, the G′ of PVA/DMSO solution with narrow MWD was lower than that of PVA/DMSO solution with broad MWD at the similar M<SUB>w</SUB>. It could be interpreted as a consequence of the formation of three-dimensional gel structure through the polar interactions by hydroxyl groups whose strength was dependent on shearing conditions and MWD.</P>

직사각형 단면을 갖는 유체 저장 구조물의 거동에 관한 연구

박장호 한국산업안전학회 2003 한국안전학회지 Vol.18 No.1

Dynamic behavior of flexible rectangular liquid storage structures is analysed by the developed method. The rectangular liquid storage structures are assumed to be fixed to the ground and a moving coordinate system is used. The irrotational motion of invicid and incompressible ideal fluid is represented by two analytic solutions. One is the solution of the fluid motion in the rigid rectangular liquid storage structure due to ground motions and the other is the solution of the fluid motion by the motion of the wall in the flexible rectangular liquid storage structure. The motion of structure is modeled by finite elements. The fluid-structure interaction effect is reflected into the coupled equation of motion as added fluid mass matrix. The free surface sloshing motion and hydrodynamic pressure acting on the wall in the flexible rectangular liquid storage structure due to the horizontal ground motion are obtained by the developed method and verified.

Effect of precursor molecular structure while synthesizing hetero-carbon nanomaterials via solution plasma process

현광룡 한국마린엔지니어링학회 2023 한국마린엔지니어링학회지 Vol.47 No.2

Solution plasma processes (SPP) have recently attracted significant attention for the synthesis of heterocarbon nanomaterials (HCNs). However, to date, very few studies have reported the control of HCNs structures using SPP. Therefore, the factors affecting the structure of HCNs were investigated using a precursor with a similar molecular structure. In this study, powder X-ray diffraction and Raman spectroscopy results revealed that the nitrogen conjugation in the cyanopyrazine molecular structure could lead to facile crystalline carbon formation compared to the pyrazine precursor.

Solution Structure of Water-soluble Mutant of Crambin and Implication for Protein Solubility

Kang, Su-Jin,Lim, Jong-Soo,Lee, Bong-Jin,Ahn, Hee-Chul Korean Chemical Society 2011 Bulletin of the Korean Chemical Society Vol.32 No.5

Water-soluble mutant of intrinsically insoluble protein, crambin, was produced by mutagenesis based on the sequence analysis with homologous proteins. Thr1, Phe13, and Lys33 of crambin were substituted for Lys, Tyr, and Lys, respectively. The resultant mutant was soluble in aqueous buffer as well as in dodecylphosphocholine (DPC) micelle solution. The $^1H-^{15}N$ spectrum of the mutant crambin showed spectral similarity to that of the wild-type protein except for local regions proximal to the sites of mutation. Solution structure of water-soluble mutant crambin was determined in aqueous buffer by NMR spectroscopy. The structure was almost identical to the wild-type structure determined in non-aqueous solvent. Subtle difference in structure was very local and related to the change of the intra- and inter-protein hydrophobic interaction of crambin. The structural details for the enhanced solubility of crambin in aqueous solvent by the mutation were provided and discussed.

Fabrication of Nanoshell-Based 3D Periodic Structures by Templating Process using Solution-derived ZnO

Araki, Shinji,Ishikawa, Yasuaki,Wang, Xudongfang,Uenuma, Mutsunori,Cho, Donghwi,Jeon, Seokwoo,Uraoka, Yukiharu Springer US 2017 NANOSCALE RESEARCH LETTERS Vol.12 No.1

<P>Fabrication methods for a 3D periodic nanostructure with excellent and unique properties for various applications, such as photonic and phononic crystals, have attracted considerable interest. Templating processes using colloidal crystals have been proposed to create nanoshell-based 3D structures over a large area with ease. However, there are technical limitations in structural design, resulting in difficulties for structural flexibility. Here, we demonstrate a combination of proximity field nanopatterning and infiltration processes using solution-derived ZnO for a nanoshell-based 3D periodic structure with high structural flexibility and controllability. A unique process of infiltration of a solution-derived material into a polymeric template prepared by a proximity field nanopatterning process achieves the fabrication of a pre-formed layer that works as a protective layer for the template and framework for the inverse structure. Subsequently, this process shows the controllability of nanoshell thickness and significant improvement in the structure height shrinkage factor (16%) compared to those of a previous non-vacuum infiltration method (34%). The proposed method offers high controllability and flexibility in the design of structural sizes, leading to further development toward nanoshell-based 3D structures for various applications including energy devices and sensors.</P><P><B>Electronic supplementary material</B></P><P>The online version of this article (doi:10.1186/s11671-017-2186-6) contains supplementary material, which is available to authorized users.</P>

Solution Structure of Human Orexin-A: Regulator of Appetite and Wakefulness

Kim, Hai-Young,Hong, Eun-Mi,Kim, Jae-Il,Lee, Weon-Tae Korean Society for Biochemistry and Molecular Biol 2004 Journal of biochemistry and molecular biology Vol.37 No.5

Orexin-A and orexin-B (hypocretin-1 and hypocretin-2, respectively) are important hypothalamic neuro-peptides, which are encoded by a single mRNA transcript and stimulate food intake as well as regulate wakefulness. Here we determined the solution structure of orexin-A by NMR spectroscopy and by simulated-annealing calculation. The structural features of orexin-A involve two $\alpha$-helices, with the hydrophobic residues disposed to on one side of helix, and hydrophilic residues to the other. A hydrophilic turn induced by two disulfide bonds provides the key difference between orexin-A and -B. With previous mutagenic studies, the derived structure of orexin-A provides us with a structure-functional view for novel drug design.

Solution Structure of Human Orexin-A: Regulator of Appetite and Wakefulness

( Hai Young Kim ),( Eun Mi Hong ),( Jae Il Kim ),( Weon Tae Lee ) 생화학분자생물학회 2004 BMB Reports Vol.37 No.5

Orexin-A and orexin-B (hypocretin-1 and hypocretin-2, respectively) are important hypothalamic neuro-peptides, which are encoded by a single mRNA transcript and stimulate food intake as well as regulate wakefulness. Here we determined the solution structure of orexin-A by NMR spectroscopy and by simulated-annealing calculation. The structural features of orexin-A involve two a-helices, with the hydrophobic residues disposed to on one side of helix, and hydrophilic residues to the other. A hydrophilic turn induced by two disulfide bonds provides the key difference between orexin-A and -B. With previous mutagenic studies, the derived structure of orexin-A provides us with a structure-functional view for novel drug design.

남매 관계 서사민요의 구조적 특징과 의미

서영숙 한국민요학회 2009 한국민요학 Vol.25 No.-

This paper concerns about the structural characteristics and meaning of folk ballads about relation between brother and sister. Folk ballads about relation between brother and sister consists of two types. (1) The sister who laments because her brother suspects her play with love (2) The sister who laments because her brother didn't save her from the river. The structure can be classified with three sub-types : the first is the type of desire completion, the second is the type of demand frustration, and the last is the mixed type. Most of folk ballads about relation between brother and sister belong to the type of demand frustration. They are narrated in the viewpoint of a sister and the third person is intervened between a brother and a sister. Most of folk ballads about relation between brother and sister are closed with the unhappy ending because of these third persons who are a man and a brother's wife. In the closure a sister dies to testify her purity of due to bet brother. The death of a sister is a sort of paradoxical solution. This means that it is not easy fur brother and sisters in the traditional society to be happy in the family. Woman not married can not be a member of her family forever because they have to be a member of her husband's family after marriage. Therefore they are not treated proper. This shows the reality of lire and a person's spiritlessness confronting with the reality in the traditional society. People who create and transmit folk ballads about relation of brother and sister express their consciousness through them as follows. 1) They frustrate at the reality that the relation between a brother and a sister cannot be in harmony. 2) They express the suffering of women not married and criticize a traditional family system. 3) They reflect the low status of women not married and make people reconsider them carefully. Folk ballads about relation of brother and sister makes women out married conceive that their brother can not take care of them forever and they have to prepare the new independent life separated from their brother. So these songs express the pain of growth from a maiden to a woman. These songs are composed of a dramatic narrative story and contains the frankness in people's consciousness. They could, therefore, be got very important valuation in literal estimation. This paper concerns about the structural characteristics and meaning of folk ballads about relation between brother and sister. Folk ballads about relation between brother and sister consists of two types. (1) The sister who laments because her brother suspects her play with love (2) The sister who laments because her brother didn't save her from the river. The structure can be classified with three sub-types : the first is the type of desire completion, the second is the type of demand frustration, and the last is the mixed type. Most of folk ballads about relation between brother and sister belong to the type of demand frustration. They are narrated in the viewpoint of a sister and the third person is intervened between a brother and a sister. Most of folk ballads about relation between brother and sister are closed with the unhappy ending because of these third persons who are a man and a brother's wife. In the closure a sister dies to testify her purity of due to bet brother. The death of a sister is a sort of paradoxical solution. This means that it is not easy fur brother and sisters in the traditional society to be happy in the family. Woman not married can not be a member of her family forever because they have to be a member of her husband's family after marriage. Therefore they are not treated proper. This shows the reality of lire and a person's spiritlessness confronting with the reality in the traditional society. People who create and transmit folk ballads about relation of brother and sister express their consciousness through them as follows. 1) They frustrate at the reality that the relation between a brother and a sister cannot be in harmony. 2) They express the suffering of women not married and criticize a traditional family system. 3) They reflect the low status of women not married and make people reconsider them carefully. Folk ballads about relation of brother and sister makes women out married conceive that their brother can not take care of them forever and they have to prepare the new independent life separated from their brother. So these songs express the pain of growth from a maiden to a woman. These songs are composed of a dramatic narrative story and contains the frankness in people's consciousness. They could, therefore, be got very important valuation in literal estimation.

Solution Structure of Water-soluble Mutant of Crambin and Implication for Protein Solubility

Su-Jin Kang,이봉진,Jongsoo Lim,Hee-Chul Ahn 대한화학회 2011 Bulletin of the Korean Chemical Society Vol.32 No.5

Water-soluble mutant of intrinsically insoluble protein, crambin, was produced by mutagenesis based on the sequence analysis with homologous proteins. Thr1, Phe13, and Lys33 of crambin were substituted for Lys, Tyr,and Lys, respectively. The resultant mutant was soluble in aqueous buffer as well as in dodecylphosphocholine (DPC) micelle solution. The ^1H-^15N spectrum of the mutant crambin showed spectral similarity to that of the wild-type protein except for local regions proximal to the sites of mutation. Solution structure of water-soluble mutant crambin was determined in aqueous buffer by NMR spectroscopy. The structure was almost identical to the wild-type structure determined in non-aqueous solvent. Subtle difference in structure was very local and related to the change of the intra- and inter-protein hydrophobic interaction of crambin. The structural details for the enhanced solubility of crambin in aqueous solvent by the mutation were provided and discussed.

Polymers with Diphosphonium Structure Showing Lower Critical Solution Temperature Behavior as Draw Solute for Forward Osmosis Process

박찬혁,주창하,김태형,강신우,강효 한국공업화학회 2019 한국공업화학회 연구논문 초록집 Vol.2019 No.0

We synthesized thermo-responsive polymers, a series of poly(alkane-1, #-diylbis(tributylphosphonium) 4-vinylbenzenesulfonate) (PSSBP#, # = 8, 6, and 4), where # is number of carbons in centered bridge of diphosphonium moiety, to confirm potential application as draw solute in forward osmosis (FO) process. These polymers show lower critical solution temperature (LCST) property in aqueous solution, which is an essential factor for recovering draw solute from pure water. The LCST of aqueous solutions of PSSBP8, PSSBP6, and PSSBP4 were confirmed approximately 30, 38, 26 °C at 20 wt% concentration, respectively. When concentration of PSSBP8 draw solution was 20 wt%, water flux and reverse solute flux were determined to be 1.84 LMH, and 1.12 gMH approximately in pressure retarded osmosis (PRO) mode. PSSBP# can be a next-generation draw solute due to effective recovery. Therefore, this study can give inspiration for novel ideas in development of draw solute and availability as draw solute.