• Journal of The Korean Astronomical Society
• /
• v.9 no.1
• /
• pp.9-14
• /
• 1976

Godel models of the universe filled with fluid are studied in the framework of the Einstein-Cartan theory of gravitation. It is assumed that the models admit a group of motions simply transitive on space-time. The combined effects of spin and rotation(vorticity) are studied with a particular attention to whether the held equations impose any restriction on alignement of spin direction (a polarized spin distribution). The solutions are found explicitly in a closed form, which show that spin components are vanishingly small except in the direction of z-axis (the compass of inertia) in which they can assume an arbitrary distribution.

• The korean journal of orthodontics
• /
• v.33 no.2 s.97
• /
• pp.131-140
• /
• 2003

The purpose of this study was to evaluate clinical applications of electroplating method through investigation of the physical properties of orthodontic rectangular wires according to varying their cross section. For the study, it was accomplished to electroplate the 0.016-inched orthodontic rectangular stainless steel wire. The cross section of stainless steel orthodontic rectangular wire increased from $0.016{\times}0.016inch\;to\;0.017{times}0.017inch$ by electroplating. The wire was heat treated to improve an adhesion between the wire and electroplated metal. h three-point bending test and torsion test were conducted in order to compare physical properties among three wire groups; $0.016{\times}0.016wires(group 016),\; electroplated\;0.016{\times}0.016wires(group\;016P)\;and\;0.017{\times}0.017$ wires (group 017). Through the investigations of each wire group, following results were obtained 1. At three-point bending test, the group Ol6P showed higher tendency in the degree of stiffness, yield strength and ultimate tensile strength than the group 016. Stiffness and ultimate tensile strength showed statistically significant differences between two groups at three-point bending test (p<0.05). 2. Stiffness, yield strength, and ultimate tensile strength of the group 016P showed lower tendency than those of the group 017 Stiffness showed statistically significant differences between two groups at three-point bending test (p<0.05). 3. Torque/twist rate, yield torsional moment, and ultimate torsional moment of the group 016P showed higher tendency than those of the group 016. All measurements showed statistically significant differences between two groups alter torsion test (p<0.05). 4. Torque/twist rate, yield torsional moment, and ultimate torsional moment of the group 0166P showed lower tendency than those of the group 017. Yield torsional moment, and ultimate torsional moment showed statistically significant differences between two groups after torsion test (p<0.05).

• Bulletin of the Korean Chemical Society
• /
• v.11 no.2
• /
• pp.144-149
• /
• 1990

Conformational free energy calculations using an empirical potential function (ECEPP/2) and the hydration shell model were carried out on the sulfonylurea herbicides of bensulfuron methyl (Londax) and metsulfuron methyl (Ally). The conformational energy was minimized from starting conformations which included possible combinations of torsion angles in the molecule. The conformational entropy of each conformation was computed using a harmonic approximation. To understand the hydration effect on the conformation of the molecule in aqueous solution, the hydration free energy of each group was calculated and compared each other. It was found that the low-free-energy conformations of two molecules in aqueous solution prefer the overall folded structure, in which an interaction between the carbonyl group of ester in aryl ring and the first amido group of urea bridge plays an important role. From the analysis of total free energy, the hydration and conformational entropy are known to be essential in stabilizing low-free-energy conformations of Londax, whereas the conformational energy is proved to be a major contribution to the total free energy of low-free-energy conformations of Ally.

• Journal of The Korean Society of Integrative Medicine
• /
• v.8 no.2
• /
• pp.75-88
• /
• 2020

Purpose : Dysmenorrhea can be caused by misalignment of the pelvis. Since pilates stabilization exercise is a methods that affects pelvic alignment by inducing contraction of abdominal muscles, the purpose of this study is to determine whether dysmenorrhea is reduced when pilates stabilization exercise is applied. Methods : 47 dysmenorrhea patients were randomly divided into experimental (n=23) and control (n=24) groups. The experimental group performed pilates stabilization exercise three times a week for 12 weeks, and the control group did not perform any intervention. Abdominal muscle thickness, lumbar pelvic alignment, and dysmenorrhea were measured before intervention, 6 weeks, and 12 weeks after intervention to determine the mean change over time and the effect of group and factor interactions (repeated measured ANOVA and contrast test for each period). Results : In the experimental group, the thickness of the transverse abdominis, internal oblique, and external oblique muscles were increased significantly by group and period (p<.05). The pelvic torsion, lordosis and dysmenorrhea were also significantly decreased by group and period. But the control group did not change significantly in any of the variables. Conclusion : Applying pilates stabilization exercise to women with dysmenorrhea may be an effective intervention that contributes to relieving dysmenorrhea by correcting the stability and alignment of the lumbar pelvis.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
• /
• v.28 no.1
• /
• pp.1-7
• /
• 2022

Purpose: The purpose of this study is to examine the unstable wall squat exercise and stable bridge exercise on posture in normal adults. Methods: The subjects of this study were 34 university students who were normal health adults, equally and randomly allocated to a unstable wall squat exercise group (male 7, female 10), an experimental group, and a stable bridge exercise group, a control group. Both did so for 30 minutes three times per week over a six-weeks period. Using Back Mapper, their trunk inclination (TIN), trunk imbalance (TIM), pelvic position (PPO), pelvic torsion (PTO), pelvic rotation (PRO) and the position of their scapula (PSA) were evaluated. Results: When the pre-test and post-test results of experimental group and control group were compared, statistically significant differences in TIN, PTO and PSA of experimental group were seen. Conclusion: Unstable wall squat exercise accompanied by abdominal drawing-in may be applied as a method to correct the posture in normal adults.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
• /
• v.19 no.1
• /
• pp.63-68
• /
• 2013

Background: The purpose of this study is to examine the effects of unstable bridge exercise on the posture of female university students. Methods: The subjects of this study were 30 female university students who were equally and randomly allocated to a unstable bridge exercise group, an experimental group, and a stable bridge exercise group, a control group. Both did so for 30 minutes three times per week over a six-week period. Using BackMapper, their trunk inclination (TIN), trunk imbalance (TIM), pelvic position (PPO), pelvic torsion (PTO), pelvic rotation (PRO), and the position of their scapulae (PSA) were evaluated. Results: The unstable bridge exercise group obtained significant results in TIN, TIM, PPO, PTO and PSA, while the stable bridge exercise group obtained significant results in TIN, PPO. Conclusion: unstable bridge exercise may be applied as a method to correct the posture of average adults.

• Korean Journal of Crystallography
• /
• v.2 no.2
• /
• pp.13-21
• /
• 1991

X-ray methods have been used to determine the chain conformation and packing of the thermotropic liquid crystalline copolyester prepared from 50% tarephthaloyl chloride(TPA) and 50% (1-phenylethyl) hydroquinone(PEHQ). The x-ray patterns of annealed melt-spun fibers contain a series of annealed melt-Pointing to a well ordered crystalline structure, despite the random sense(2 or 3-) of the 1-phenylethyl substiuttion on the TPA-hydroquinone backbone. The crystalline fiber is monoclinic with space group P2l and the unit cell has dimensions 11=12.77 A, b=10.17 A (upique axis), c=12.58 h (fiber axis). and β=90.1° and contains TPA-PEHO units of to or chains. The random substitution of 1-phenylethyl groups was modelled by placing these groups at both the 2and 3 positions and giving each a weight of one-hal(. T he structure has been refined by linked a rom least square methods(LALS) against 16 observed and 21 unobserved reflections. and had a final R value of 0.20. Packing of the side chains is effected by staggering adjacent chains along the b axis by approximately c/2, so that the side chains are interleaved. The phenyl-COO and COO-phenyl torsion angles are -6.1 and 65.6, respectively, such that the main chain phenyls are mutually inclined at 59.5 (the ester groups are assumed to be planar). These torsion angles compare very well with those for the model compounds, notably phenylbenzoate, and can be used in future analyses of the structures of more complex random sequence copolyesters.

• Biomolecules & Therapeutics
• /
• v.12 no.2
• /
• pp.62-67
• /
• 2004

Trauma remains one of the important sources leading to systemic inflammatory response anti sub-sequent multiple organ failure. Although hepatic microvascular dysfunction occurs during trauma, the mechanism responsible remains unclear. The aim of this study was to investigate the effect of trauma on hepatic vascular stress gene expression. Femur fracture (EFx) was induced by torsion to the femur at midshaft. Liver samples were taken for RT-PCR analysis of mRNA for gtenes of interest: endothelin-1 (ET-1), its receptors $ET_A$ and $ET_B$, nitric oxide synthases (iNOS and eNOS), cyclooxygenase-2 (COX-2), heme oxygenase-1 (HO-1), and tumor necrosis tactor-${\alpha}$ (TNF-${\alpha}$). The expression of ET-1 mRNA was significantly increased by FFx. Expression of mRNA in FFx group showed no change in $ET_A$, $ET_B$, iNOS and HO-1 and showed a slight increase of 2.2-fold and 2.7-fold for eNOS tll1d COX-2, respectively. The level of TNF-${\alpha}$ mRNA significantly increased in FFx group. In conclusion, mild trauma alone causes little change in expression of vasoactive mediators.

• Journal of the Korean Mathematical Society
• /
• v.48 no.1
• /
• pp.191-205
• /
• 2011

It is well known that for a Krull domain R, the divisor class group of R is a torsion group if and only if every subintersection of R is a ring of quotients. Thus a natural question is that under what conditions, for a non-Krull domain R, every (t-)subintersection (resp., t-linked overring) of R is a ring of quotients or every (t-)subintersection (resp., t-linked overring) of R is at. To address this question, we introduce the notions of *-compact packedness and *-coprime packedness of (an ideal of) an integral domain R for a star operation * of finite character, mainly t or w. We also investigate the t-theoretic analogues of related results in the literature.

• Archives of Pharmacal Research
• /
• v.13 no.1
• /
• pp.43-50
• /
• 1990

Conformational free energy calculations using an empirical potential function (ECEPP/2) and hydration shell model were carried out on the four-4-aminodiphenyl sulfone analogues of 4, 4'-diamino-2' methyldiphenyl sulfone, 4, 2', 4-triaminodiphenyl sulfone, 4, 4'-diaminodiphenyl sulfone, and 4-aminodiphenyl sulfone as antibacterial agents on Mycobacterium lufu. The conformational energy was minimized from starting conformations which included possible combinations of torsion angles in the molecule. The conformational entropy change of each conformation was computed using a harmonic approximation. To understand the hydration effect on the conformation of the molecule in aqueous solution, the contributions of water-accessible volume and the hydration free energy of each group or atom in the lowest-free-energy conformation was calculated and compared each other. From comparison of the computed lowest-free-energy conformations of four analogues with their antibacterial activities, it is known that the conformation and the hydrophobicity of sulfonyl group and its adjacent carbon atom in each compound are the essential factors to show the strong antibacterial activity.