• Journal of the Korean Magnetics Society
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• v.7 no.1
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• pp.44-48
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• 1997

The nanocrystalline Nd-Fe-B alloys with low Nd content were prepared by rapid solidification technique. The alloys consist of both$\alpha$-Fe as the main phase and $Nd_2Fe_{14}B_1$ as a secondary phase and have an ultrafine grain structure of about 30 nm. The addition of Ga in $Nd_4Fe_{82}B_{10}Mo_3Cu_1$ alloy increases remanence up to 1.29 T and improves squareness. The nanocrystalline $Nd_5Fe_{81}B_9Mo_3Cu_1Ga_1$ alloy has a volume fraction of $Nd_2Fe_{14}B_1$ phase of around 35% due to the increase of Nd content and shows an improved coercivity. The remanence, coercivity and energy product of optimally annealed nanocrystalline $Nd_5Fe_{81}B_9Mo_3Cu_1Ga_1$ alloy are 1.24 T, 257.4 kA/m (3.23 kOe), and 100.3 kJ/ ㎥ (12.6 MGOe), respectively.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.13 no.2
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• pp.83-87
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• 2003

$(Nd/Y)_{1.8}Ba_{}2.4Cu_{3.4}O_{7-x}$high $T_c$ superconductor was directionally grown by floating Bone melt growth process with a large temperature gradient in air. Cylindrical green rods of (Nd/Y)1.8 oxides were fabricated by cold isostatic pressing (CIP) method using rubber mold. Microstructures were observed by SEM and TEM and superconducting properties were measured by a SQUID magnetometer. Nonsuperconducting $(Nd/Y)_2BaCuO_5$ inclusions were uniformly distributed within the superconducting $(Nd/Y)Ba_2Cu_3O_x$ matrix. The directionally melt-textured (Nd/Y) 1.8 superconductor showed an onset Tc $\geq$ 90 K and a sharp superconducting transition.

• The Korean Journal of Malacology
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• v.29 no.4
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• pp.335-341
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• 2013

The seven mitochondrial DNA regions (ND2, ND5, ND4, ND4L, ND6, ND1 and 12SrRNA) of Haliotis discus hannai were examined to estimate the availability as a genetic marker for the study of population genetic. The region with the highest genetic variation was ND4 (Haplotype diversity = 1.0000, Nucleotide diversity = 0.0108). On the other hand, ND2 and ND1 regions have significantly appeared genetic divergence between clusters (divergence of 90% and 87%). Also, pairwise $F_{ST}$ between clusters within ND2 and ND1 regions showed high values; 0.4061 (P = 0.0000), 0.4805 (P = 0.0000) respectively. Therefore we can infer that it is the most efficient and accurate way to analyze the region of ND4 with the highest variation in addition to the regions of ND2 and ND1, which formed clusters with high bootstrap value, for study of population genetic structure in this species.

• Journal of Sericultural and Entomological Science
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• v.45 no.1
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• pp.6-9
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• 2003

This experiment was done to know developmental characteristics of Sericin jam. Incubation periods were 10 day 2 hr, and 10 day 1 hr. 11 day 1 hr for Nd-s jam, N $d^{H}$ jam, and Baegok jam, respectively. Hatching rates were 83.9, 83.3 and 96.0% for Nd-s jam, N $d^{H}$ jam, and Baegok jam. Larval periods were, 20 days 1 hr for Nd-s jam, 20 days 5 hrs for N $d^{H}$ jam, and 22 days 12 hrs for Baegok jam. Death rate of larvae was highest in N $d^{H}$ iam, followed by Nd-s jam and Baegok jam. Pupation rate was highest in Baegok Jam followed by Nd-s jam and that of N $d^{H}$ jam was the lowest among the three. Cocoon weight was 1.39, 1.08, and 2.01 g for Nd-s jam, N $d^{H}$ jam, and Baegok jam, respectively. Shell weight were 13, 3, and 48 cg for Nd-s jam, N $d^{H}$ jam, and Baegok jam. Cocoon shell ratios were 9.0% for Nd-s jam, 2.8% for N $d^{H}$ jam and 23.9% for Baegok jam. Cocoon sizes were 30.6${\times}$15.8 mm for Nd-s jam, 24.7${\times}$14.9 mm for N $d^{H}$ jam and 35.8 ${\times}$ 20.5 mm(1${\times}$w) for Baegok jam.w) for Baegok jam.

• Applied Chemistry for Engineering
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• v.24 no.3
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• pp.227-230
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• 2013

The phase change of $(U_{1-x}Nd_x)_3O_8$ powder produced by oxidation of Nd-doped $UO_2$ pellet at $500^{\circ}C$ was investigated by high temperature oxidation heat treatment at $900{\sim}1500^{\circ}C$ under an air atmosphere. The XRD analysis results showed that the formation of $(U_{1-y}Nd_y)O_{2+z}$ phase and $U_3O_8$ phase from metastable $(U,Nd)_3O_8$ phase initiated at a temperature of $1000^{\circ}C$. The relative integrated intensity of $(U_{1-y}Nd_y)O_{2+z}$ phase to $U_3O_8$ phase increased with increasing of the oxidation temperature from 1100 to $1500^{\circ}C$. And also, it was found from the SEM observation that the particle size of $(U_{1-y}Nd_y)O_{2+z}$ phase increased with increasing of the oxidation temperature. However, electrone probe X-ray microanalyzer (EPMA) analysis results showed that Nd contents in $(U_{1-y}Nd_y)O_{2+z}$ phase decreased with increasing of the oxidation temperature. This behavior on the ground of XRD, SEM, and EPMA analysis data could be interpreted in terms of the transportation of U ions from $U_3O_8$ phase into $(U_{1-y}Nd_y)O_{2+z}$ phase through the interface of two phases during high temperature oxidation.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2001.05a
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• pp.329-332
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• 2001

In this paper, it's shown that the saturable absorber Nd:LSB has a capability as a saturable absorber in Q-switching system. In the passively Q-switched 1.3${\mu}{\textrm}{m}$ Nd:YAG laser with saturable absorber, we theoretically investigated the optimized output mirror, peak power, output power, pulse width and output efficiency. The passively Q-switched Nd:YAG laser with saturable absorber Nd:LSB gives peak power of 30MW and pulse width of 6.23 ps at 30cm resonator length and output mirror reflectivity 98%. Consequently the output energies are 143, 200 and 209 $\mu$J at loss of 2.2%, 2.1% and 1.5%, respectively.

• Journal of the Korean Magnetics Society
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• v.9 no.3
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• pp.154-158
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• 1999

Magnetic properties and microstructure of nanocrystalline $\alpha$-(Fe, Co)-based Nd-(Fe, Co)-B-Nb-Cu alloys have been investigated. $Nd_x(Fe_{0.9}Co_{0.1})_{90-x}B_6Nb_3Cu_1$(x=2, 3, 4, 5, 6) alloys prepared by rapid solidification process show amorphous phase except the one with x=2. By a proper annealing, the amorphous in the alloy is changed to a nanocrystalline phase. It is confirmed that the nanocrystalline alloys are composed of $\alpha$-(Fe, Co) and $Nd_2(Fe, Co)_{14}B_1$ phase. The optimally annealed $Nd_3(Fe_{0.9}Co_{0.1})_87B_6Nb_3Cu_1$ alloy shows the highest remanence of 1.55 T. The coercivity increases with the increase of Nd content The maximum coercivity of 4.6 kOe is obtained from an optimally annealed $Nd_6(Fe_{0.9}Co_{0.1})_84B_6Nb_3Cu_1$ alloy, resulting in the maximum energy product of 10.6 MGOe.

• Journal of the Korean Magnetics Society
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• v.5 no.5
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• pp.880-894
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• 1995

Magnetic properties of $Nd_{x}{(Fe_{0.9}Co_{0.1})}_{90-x}B_{6}Nb_{3}Cu_{1}(x=\;3,\;4,\;5)$ rrelt-spun alloys with 6 at% B content were studied aiming for finding out a new $\alpha$-Fe based Nd-Fe-B nanocrystalline alloy with good hard magnetic properties. $Nd_{x}{(Fe_{0.9}Co_{0.1})}_{90-x}B_{6}Nb_{3}Cu_{1}$ melt-spun alloys prepared by RSP crystallized to nanocrystalline phase. An optimally annealed $Nd_{3}{(Fe_{0.9}Co_{0.1})}_{87}B_{6}Nb_{3}Cu_{1}$ melt-spun alloys had larger volume ratio of $\alpha$-Fe(Co) than that of higher Nd content alloy and showed high remanence of about 1.6 T. On the contrary, the increase of Nd content in $Nd_{x}{(Fe_{0.9}Co_{0.1})}_{90-x}B_{6}Nb_{3}Cu_{1}$ alloys gave rise to gradual increase of an amount of $Nd_{2}{(Fe,\;Co)}_{14}B$ phase and improved coercivity. An optimally annealed $Nd_{5}{(Fe_{0.9}Co_{0.1})}_{85}B_{6}Nb_{3}Cu_{1}$ alloy showed the most improved hard mag¬netic properties. The remanence, coercivityand energy product of the alloy were 1.35 T, 219 kA/m (2.75 kOe), and $129\;kJ/m^{3}$ (16.2 MGOe), respectively.

• Journal of the Korean Magnetics Society
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• v.5 no.1
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• pp.38-41
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• 1995

The effects of Nb and Cu additives as will as substitutional Co into $Nd_{4}Fe_{85.5}B_{10.5}$ melt-spun alloy were studied aiming for finding a $\alpha$-Fe based Nd-Fe-B composite alloys with high energy product. The addition of Nb and Cu to $Nd_{4}Fe_{85.5}B_{10.5}$ decreased the average grain size and increased the coercivity up to 207kA/m(2.6kOe), Further-more, the substitution of Co for Fe in $Nd_{4}Fe_{82}B_{10}Nb_{3}Cu_{1}$ alloy resulted in the decrease of the average grain size (<20nm) and improved the hard magnetic properties. The remanence, coercivity and energy product of optimally annealed $Nd_{4}Fe_{74}Co_{8}B_{10}Nb_{3}Cu_{1}$ alloy were 1.345, 219kA/m(2.75kOe) and $95.5kJ/m^{3}$(12MGOe), respectively.

• Progress in Superconductivity
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• v.10 no.2
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• pp.128-132
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• 2009

Polycrystalline samples of $(Ru_{0.8}Nb_{0.2})Sr_2(Gd_{1.5-x}Nd_xCe_{0.5})Cu_2O_z$($ 0{\leq}x{\leq}1.25$) have been synthesized by a solid-state reaction route. The X-ray diffraction data revealed that the Nd solubility limit can be placed between x=0.5 and x=0.75. The superconducting transition temperature decreased with increasing Nd content, confirming that Nd entered the lattice. Room-temperature thermoelectric power measurements showed that all the samples are in the underdoped state and the partial substitution of Nd for Gd resulted in a decrease in the carrier density on the superconducting layers.