• Journal of the Korean Chemical Society
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• v.9 no.4
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• pp.174-178
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• 1965

p-Phenylenediamine dihydrobromide and p-phenylenediamine dihydrochloride are found to be isomorphous. p-Phenylenediamine dihydrobromide is triclinic with lattice parameters, $a=4.52{\pm}0.02{\AA}\;b=6.13{\pm}0.02{\AA},c=8.88{\pm}0.03{\AA},\;{\alpha}=111{\pm}1^{\circ},\;{\beta}=97{\pm}1^{\circ},\;{\gamma}=101{\pm}1^{\circ}.$ It belongs to space group $P\bar{1}$, and there is one molecule in the unit cell. The crystal structure is determined according to the method of Fourier synthesis from the electron density projections in three principal crystallographic axes. The crystal structure, thus determined is refined by the method of two-dimensional difference Fourier synthesis.

• Journal of the Korean Chemical Society
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• v.16 no.1
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• pp.18-24
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• 1972

Benzidine dihydrochloride crystallizes in the triclinic system. The space group is $P_1$. The unit cell dimensions are; a = 4.38${\pm}$0.01, b = 5.76${\pm}$0.01, c = 12.82${\pm}$0.02${\AA}$, $\alpha$ = 101.5${\pm}$0.2, $\beta$ = 99.5${\pm}$0.2, $\gamma$ = 99.5${\pm}$0.2$^{\circ}$; with one molecule per unit cell. The crystal structure has been solved by two dimensional Patterson and by trial and error methods, and refined by means of two dimensional differential synthesis. The bond distances are C-C(*) = 1.40${\pm}$0.02, C-C = 1.52${\pm}$0.02, C-N = 1.51${\pm}$0.03 and N-H${\cdot}{\cdot}{\cdot}$Cl = 3.21${\pm}$0.03${\AA}$. The structure consists of hydrogen bonded molecular layers, extending to the (100) plane, and the hydrogen bonding scheme is similar to that of p-phenylenediamine dihydrochloride. The adhesion between hydrogen bonded molecular layers is due to van der Waals forces.

• Journal of the Korean Chemical Society
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• v.9 no.3
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• pp.142-147
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• 1965

The crystal structure of p-phenylenediamine dihydrochloride has been determined from X-ray oscillation and Weissenberg photographs. The crystal is triclinic, space group $C_i1-P{\bar\1},$ with cell dimensions $a = 4.38{\pm}0.02, b = 5.90{\pm}0.02, c = 8.76{\pm}0.03 {\AA}, {\alpha} = 110{\AA}1, {\beta} = 96{\pm}1\; and\; {\gamma} = 101{\pm}1^{\circ}.$ There is one molecule in the unit cell. The atomic coordinates were found by means of two-dimensional Fourier projection and ($F_o-F_c$) projection along the a, b and c axes. The structure of p-phenylenediamine dihydrochloride is discussed in relation to the structures of hexamethylenediamine dihydrochloride, hexamethylenediamine dihydroiodide and ethylenediamine dihydrochloride.

• Journal of the Korean Society of Marine Environment & Safety
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• v.22 no.5
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• pp.547-553
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• 2016

Black carbon (BC) contained in particulate matter (PM) originating from the exhaust gases of ships' diesel engines has been receiving great attention as a cause of glacial melting and warming in the polar regions. In this study, we took samples from various locations of PM emitted from the training ship (T/S) HANBADA's main engine, in cooperation with the Korea Maritime and Ocean University. We analyzed the structure and characteristics of these samples using high-resolution transmission electron microscopy (HR-TEM) and applied our findings as fundamental research for developing PM reduction technology. We also employed our results to determine appropriate preemptive action to meet upcoming PM/BC regulations. In addition, we confirmed the emission trend of pollutants from exhaust gases under various engine operating conditions using an exhaust gas analyzer. Results obtained from the analysis of HR-TEM images showed that the structure of the PM is chain-like wispy agglomerates consisting of a number of individual spherical particles. As the sampling location was moved away from the turbo charger (T/C) towards the funnel, more condensates were observed at a low temperature and the molecular structure of the PM lost its characteristic BC structure as an amorphous structure gradually appeared. Furthermore, through the analysis of exhaust gases, we predicted a decrease in PM concentration in the exhaust stream as engine rpm increase.

• The korean journal of orthodontics
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• v.20 no.1
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• pp.87-100
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• 1990

This study was designed to compare the craniofacial structure of orthodontic patients with that of normal adult. For that purpose, 61 male and 64 female adults with normal occlusion were selected and utilizing the cephalogram that had taken under the natural head position and computerized graphic image, the special position of each anatomical structure against true horizontal and vertical reference plane was investigated. The following results were obtained. 1. The absolute special positions of each anatomic structure were calculated. 2. The inclination of Sella-Nasion plane to true horizontal plane was $8.3^{\circ}{\pm}3.9$ in male and $9.3^{\circ}{\pm}3.2^{\circ}$ in female. 3. The inclination of Frankfort horizontal plane to true horizontal plane was $1.3^{\circ}{\pm}3.0^{\circ}$ in male and $1.7^{\circ}{\pm}3.0^{\circ}$ in female. 4. The dimensions of Nasion-sella and Nasion-Anterior nasal spine to be used as the basic units of mesh diagram were $70.7mm{\pm}3.1mm$, $61.8mm{\pm}2.7mm$ in male and $67.8mm{\pm}3.3mm$, $57.0mm{\pm}2.6mm$ in female respectively. 5. The standard templates of craniofacial structure of male and female adult normal group were constructed. 6. The mesh diagrams of craniofacial structure of male and female adult normal group were constructed.

• The Plant Pathology Journal
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• v.37 no.2
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• pp.115-123
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• 2021

The purpose of this study was to determine the virulence structure of oat powdery mildew (Blumeria graminis f. sp. avenae, Bga) populations in Poland collected in 2014 and 2015. Powdery mildew isolates were collected from 18 locations in Poland. In total, nine lines and cultivars of oat, with different mildew resistance genes, were used to assess virulence of 180 isolates. The results showed that a significant proportion of the Bga isolates found in Poland were virulent to differentials with Pm1, Pm3, Pm6, and Pm3 + Pm8 genes. In contrast Pm4, Pm5, Pm2, and Pm7 genes were classified as resistant to all pathogen isolates used in the experiment. Based on obtained results we can state that there are differences in virulence pattern and diversity parameters between sites and years, but clear trends are not deducible.

• Communications for Statistical Applications and Methods
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• v.25 no.6
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• pp.619-631
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• 2018

Functional data analysis continues to attract interest because advances in technology across many fields have increasingly permitted measurements to be made from continuous processes on a discretized scale. Particulate matter is among the most harmful air pollutants affecting public health and the environment, and levels of PM10 (particles less than 10 micrometers in diameter) for regions of California remain among the highest in the United States. The relatively high frequency of particulate matter sampling enables us to regard the data as functional data. In this work, we investigate the dominant modes of variation of PM10 using functional data analysis methodologies. Our analysis provides insight into the underlying data structure of PM10, and it captures the size and temporal variation of this underlying data structure. In addition, our study shows that certain aspects of size and temporal variation of the underlying PM10 structure are associated with changes in large-scale climate indices that quantify variations of sea surface temperature and atmospheric circulation patterns.

• Proceedings of the KIEE Conference
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• 2005.07b
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• pp.1261-1263
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• 2005

The micro permanent magnet(PM) type stewing motor preferred solution for many small electronics position determination devices since it is small in size. Thus, there are growing demands for PM type stepping motor that greater mechanical output, smaller size. But, the design of the it, having high performance and small size is very difficult because of its complex mechanical structure. This paper deals with a development of the newly structured micro PM type stepping motor with claw-poles. We introduced the small-sized PM type stepping motor that has new structure and analyzed the magnetic characteristic of it versus general type model using 3-D finite element analysis(FEA).

• The korean journal of orthodontics
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• v.13 no.2
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• pp.201-204
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• 1983

To study the calcification of second molars in Class I malocclusion with normal craniofacial structure, the author examined cephalograms, orthopantomograms, periapical films of 538 children from 7 y 0 m to 15y 11m old who had Class I malocclusion with normal craniofacial structure, and observed the calcification stage of upper and lower second molars. The results are as follows. 1. The mean ages of crown completion of upper and lower second molars are $8.82{\pm}1.14,\;8.72{\pm}0.75$ in boys, and $8.60{\pm}1.46,\;8.22{\pm}0.92$ in girls. 2. The mean ages of root completion of upper and lower second molars are $14.25{\pm}1.46,\;14.15{\pm}0.83$ in boys, and $14.12{\pm}0.93,\;14.15{\pm}0.83$ in girls. 3. There are no difference between the calcification stages of upper second molars and those of lower second molars in both sexes.

• Journal of the Korean Chemical Society
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• v.19 no.2
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• pp.85-91
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• 1975

The crystal structure of piperidinothiosemicarbazide, $C_6H_{13}N_3S$, has been determined by single crystal X-ray analysis. The space group is P21/c with four molecules in the unit cell of dimensions $a=14.68{\pm}0.04,\;b=4.59{\pm}0.02,\;c=12.92{\pm}0.04{\AA}\;and\;{\beta}=109.4{\pm}0.2^{\circ}$. Three-dimensional photographic intensities were estimated visually. The structure has been solved by an interpretation of a Patterson synthesis and refined by block-diagonal least-squares methods to give a final R value of 0.14 for 378 observed independent reflections. There are two independent hydrogen bonds in the structure. One of them is of the type N-H${\ldots}$S with the length 3.28 and $3.39{\AA}$, and another is of the type N-H${\ldots}$N with the length $3.03{\AA}$. Apart from the hydrogen bonding system the molecules are held together in the crystal by van der Waals forces.