• Korean Journal of Crystallography
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• v.11 no.1
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• pp.22-27
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• 2000

The structure of cis-(malonato)[(4R,5R)-4,5-bis(aminomethyl)-2-isopropyl-1,3-dioxolane]platinum(II) with a potent anticancer activity has been determined by the X-ray crystallographic method. Crystal data are as follows: Pt(C/sub 11/H/sub 20/N₂O/sub 6/), M/sub 4/=471.38, monoclinic, P2₁, a=7.112(1), b=33.615(3), c=7.135(1)Å, β=116.80(1)°, V=1522.6(3)Å, and Z=4. The two independent molecules with very similar structures are approximately related by pseudo two-fold screw axis symmetry, which makes the monolinic cell look like the orthorhombic cell with one molecule in the asymmetric unit and space group C222₁. The crystal packing mode is similar to that of the analogue with the dimethyl substituents instead of the isopropyl group. The Pt atom is coordinate to two O and two N atoms in a square planar structure. The six-membered chelate ring in the leaving ligand assumes a conformation intermediate between the half chair and the boat forms. The seven-membered ring in the carrier ligand assumes a twist-chair conformation and the oxolane ring assumes an envelope conformation. Crystal packing consists of the extensive hydrogen-bonding network in the two-dimensional molecular layers and weak van der Waals interactions between these layers.

• Nuclear Engineering and Technology
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• v.53 no.7
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• pp.2174-2183
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• 2021

Helium cooled solid breeder blanket as an important blanket candidate of the Tokamak fusion reactor uses ceramic pebble bed for tritium breeding. Considering the poor effective thermal conductivity of the ceramic breeder pebble bed, thin structure of tritium breeder pebble bed is usually adopted in the blanket design. The container wall has a great influence on the thin pebble bed packing structure, especially for the assembly of mono-sized particles, and thin pebble bed will appear anisotropic effective thermal conductivity phenomenon. In this paper, thin ceramic pebble beds composed of 1 mm diameter Li₄SiO₄ particles are generated by the EDEM 2.7. The effective thermal conductivity of different thickness pebble beds in the three-dimensional directions are analyzed by three-dimensional thermal network method. It is observed that thin Li₄SiO₄ pebble bed showing anisotropic effective thermal conductivity under the practical design size. Normally, the effective thermal conductivity along the bed vertical direction is higher than the horizontal direction due to the gravity effect. As the thickness increases from 10 mm to 40 mm, the effective thermal conductivity of the pebble bed gradually increases.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37C no.11
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• pp.1138-1147
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• 2012

In this paper, an efficient power control based MF-TDMA resource allocation scheme is proposed for next generation military satellite communication systems. The proposed scheme has the flexibility is used to support heterogeneous terminals with differ in transmission capabilities. The method can be divided into two parts : burst size calculation and burst structure determination. At first, we estimate the link budget taken into account a dynamic satellite link state variation. Then, applicable ACM level and burst size is chosen. In burst structure determination phase, we reorganize the burst structure in time-frequency domain by controlling limited power, bandwidth, time resources. In particular, we compensate the power spectral density among different terminals to integrate them in same transponder, Furthermore, we increase the packing efficiency by controlling the ACM level of the burst in applicable power spectral density range. Simulation results show that the method increase the spectral efficiency and burst packing efficiency. In addition, slot allocation rejection ratio is successfully reduced.

• Computers and Concrete
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• v.3 no.5
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• pp.301-312
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• 2006

Experimental research revealed that the spatial dispersion of aggregate grains exerts pronounced influences on the mechanical and durability properties of concrete. Therefore, insight into this phenomenon is of paramount importance. Experimental approaches do not provide direct access to three-dimensional spacing information in concrete, however. Contrarily, simulation approaches are mostly deficient in generating packing systems of aggregate grains with sufficient density. This paper therefore employs a dynamic simulation system (with the acronym SPACE), allowing the generation of dense random packing of grains, representative for concrete aggregates. This paper studies by means of SPACE packing structures of aggregates with a Fuller type of size distribution, generally accepted as a suitable approximation for actual aggregate systems. Mean free spacing $\bar{\lambda}$, mean nearest neighbour distance (NND) between grain centres $\bar{\Delta}_3$, and the probability density function of ${\Delta}_3$ are used to characterize the spatial dispersion of aggregate grains in model concretes. Influences on these spacing parameters are studied of volume fraction and the size range of aggregate grains. The values of these descriptors are estimated by means of stereological tools, whereupon the calculation results are compared with measurements. The simulation results indicate that the size range of aggregate grains has a more pronounced influence on the spacing parameters than exerted by the volume fraction of aggregate. At relatively high volume density of aggregates, as met in the present cases, theoretical and experimental values are found quite similar. The mean free spacing is known to be independent of the actual dispersion characteristics (Underwood 1968); it is a structural parameter governed by material composition. Moreover, scatter of the mean free spacing among the serial sections of the model concrete in the simulation study is relatively small, demonstrating the sample size to be representative for composition homogeneity of aggregate grains. The distribution of ${\Delta}_3$ observed in this study is markedly skew, indicating a concentration of relatively small values of ${\Delta}_3$. The estimate of the size of the representative volume element (RVE) for configuration homogeneity based on NND exceeds by one order of magnitude the estimate for structure-insensitive properties. This is in accordance with predictions of Brown (1965) for composition and configuration homogeneity (corresponding to structure-insensitive and structure-sensitive properties) of conglomerates.

• Applied Chemistry for Engineering
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• v.28 no.2
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• pp.177-185
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• 2017

In the present work, the interaction of fatty acid with vesicle membrane of phospholipids was investigated using 3 different kinds of fatty acids such as stearic acid (SA), oleic acid (OA) and linoleic acid (LA). Basically, the same trend has been found in 3 fatty acid systems. The addition of fatty acid produced a close packing of liposome due to the penetration of fatty acid molecules into liposome vesicles, which resulted in a decrease in size and an increase in zeta potential of liposome. However, excessive addition of fatty acid produced a transition from liposomes to aggregates of lipid particles having polymorphic structure. The membrane fluidity, characterized by measuring membrane deformability and fluorescence anisotropy ratio of liposomes, was in good agreement with measurement results of transmission electron microscopy (TEM) and particle size. The minimum size and closest packing of liposome with SA, OA and LA were found when the molar ratios of fatty acid to lecithin were 0.70, 0.50, and 0.25 respectively.

• Journal of Integrative Natural Science
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• v.9 no.4
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• pp.255-260
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• 2016

The crystal structure of the saliciline derivatives N,N'-bis(3-chloro-2-methylsalicylidene)-1,4-butanediamine ($C_{20}H_{22}Cl_2N_2O_2$) has been determined from single crystal X-ray diffraction data. In the title compound crystallizes in the triclinic space group $P{\bar{i}}$ with unit cell dimension $a=4.6085(3){\AA}$, $b=5.9747(3){\AA}$ and $c=5.9747(3){\AA}$ [${\alpha}=83.889(4)^{\circ}$, ${\beta}=86.744(5)^{\circ}$ and ${\gamma}=82.085(5)^{\circ}$]. The title compound is essentially planar conformation. The compound lies across a crystallographic inversion centre and adopts E configurations with respect to the C-N bonds. The crystal packing of the molecules of compound is stabilized through weak O-H...N intra molecular interactions

• Journal of Integrative Natural Science
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• v.9 no.4
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• pp.261-267
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• 2016

The crystal structure of the saliciline derivatives 4-chloro-2{[(2-hydroxy-5-methylphenyl)amino]methyl}5-methylphenol ($C_{15}H_{15}ClNO_2$) has been determined from single crystal X-ray diffraction data. In the title compound crystallizes in the monoclinic space group P21/c with unit cell dimension $a=11.5241(2){\AA}$, $b=8.733(2){\AA}$ and $c=13.649(2){\AA}$ [${\alpha}=90^{\circ}$, ${\beta}=130.876(2)^{\circ}$ and ${\gamma}=90^{\circ}$]. the title compound are essentially planar conformation. The compound lies across a crystallographic inversion centre and adopts E configurations with respect to the C-N bonds. The crystal packing of the molecules of compound is stabilized through weak O-H...O inter molecular interactions.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.04a
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• pp.217-222
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• 2000

A large Pc structure building is system that consisted of bearing wall and slab joint. It has general structure stability from unity thar each members tied at joint. The strength of mortar that packing in joint among panels is important to internal force in entire building system. Do, if we could get early strength estimation with microwave. It would bring good construction planning, reduce construction time, and judge building stability and so on. The purpose of this study is to develop early estimation method for making better quality control and constructing good PC panel structure. The results of this study were as follows :1) With sealed molds, reduced moisture volatilization to more than 60% and enlarged 30% accelerated compressive strength than before one. 2) To get more accelerated strength, we should control maximum temperature difference to $30^{\circ}C$ downward 3)Interrelation with 7-day and 28-day strength were 0.831,0.902, and it is above than before one

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.32 no.3
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• pp.32-38
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• 2000

This study was carried out to determine the effect of the type of plastic pigment on the coat-ing structure and printability of coated paper. Three kinds of plastic pigments(solid-bead type binder type and hollow type) were used for hti purpose. IN this research it was observed that particle shape and structure of plastic pigment had influenced the rheology of coating color the state of packing and the properties of coated paper. Inorganic pigments used in this research were platelike kaolin clay and rhombic calcium carbonate. Three kinds of plastic pigments were blended with two inorganic pigments respec-tively. The combination of pigments were carried out(1) to determined the effect of particle structure of plastic pigment on the state of dispersion of coating color(2) to observe the effect of calendering temperature on the property of coated paper prepared with different plastic pigments. The data indicated that binder and hollow type plastic pigment gave the best results in improving the properties of coated paper such as paper gloss opacity and air pet-meability.

• Journal of Integrative Natural Science
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• v.1 no.2
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• pp.76-78
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• 2008

A series of the long-chain iron(II) alkylsulfonate hydrates were synthesized via self-assembly of surfactant alkyl chains in aqueous medium. Reaction of iron(II) salts with n-alkylsulfonate yields lamellar $Fe(CnH2n+1SO3)2{\cdot}4H_2O$. These compounds show a layered structure, as determined by XRD, consisting of alternating organic alkylsulfonate layers and inorganic iron(II) hydrate layers, with interlayer distances of upto 3.2 nm. This lamellar structure may be attributed to the amphiphilic nature of the surfactants, mediating the coordination and H-bionding interactions, and the hydrophobic alkyl chains. An alkyl chain packing of present system are differ from those of similar Cu(II) series, which are attributed from the size of hydrated metal(II) ions.