• PNF and Movement
• /
• 제13권4호
• /
• pp.197-202
• /
• 2015

Purpose: This study aimed to examine the effects of a proprioceptive neuromuscular facilitation (PNF) program on neck pain, cervical range of motion, pressure pain, and the cervical flexion-relaxation ratio in a visual display terminal (VDT) worker. Methods: We recruited a 33-year-old VDT worker diagnosed with chronic VDT syndrome. The subject was treated using a PNF program for 20 minutes a day, three times a week for six weeks. All evaluations were performed every two weeks on the first test day. Results: The PNF program resulted in a significant improvement in the subject's neck pain, cervical range of motion, pressure pain, and the cervical flexion-relaxation ratio after six weeks, in comparison to the subject's condition before treatment. Conclusion: The PNF program can be used effectively to improve neck pain, cervical range of motion, pressure pain, and the cervical flexion-relaxation ratio in visual display terminal (VDT) workers.

• Journal of Chest Surgery
• /
• 제24권3호
• /
• pp.229-244
• /
• 1991

A bioassay technique and organ bath study were performed to analyze the effects of extracellular $Ca^{2+}$ and $Ca^{2+}$-antagonists on endothelium-derived relaxing factor[s][EDRF] released from the endothelial cells of rabbit aorta. Transverse strips with intact endothelium or damaged endothelium were used for the mechanical contraction experiment using organ bath. Long segment including thoracic and abdominal aorta with endothelium [EDRF donor aorta] was perfused with Tyrode solution which was aerated with 95% $O_2-5%$ $CO_2$ mixed gas and kept at 35oC. The perfusate was bioassayed with a transverse strip of thoracic aorta with damaged endothelium. The test strip was contracted with nor-epinephrine and acetylcholine was used to stimulate the release of EDRF from endothelial cells. The results obtained were as follows; 1] The endothelium-dependent relaxation[EDR] induced by acetylcholine was biphasic; an initial rapid relaxation followed by a slow relaxation. 2] EDR induced by acetylcholine was reduced gradually with the decrease in the concentration of extracellular $Ca^{2+}$. The effect of extracellular $Ca^{2+}$ on EDR was more prominent in the late slow relaxation phase. 3] EDR to acetylcholine was not altered by acute exposure to organic $Ca^{2+}$-antagonists. Pretreatment with verapamil to the EDRF donor aortic segment did not alter the magnitude of EDR. 4] Among the inorganic $Ca^{2+}$-antagonists $Mn^{2+}$ and $Cd^{2+}$ did not inhibit EDR, whereas $Co^{2+}$ and $La^{3+}$ inhibited EDR. 5] The inhibitory response of $Co^{2+}$ to EDR developed when infused directly on the test strip. That of $La^{3+}$, however, was evoked when added to solution perfusing the donor aortic segment. The above results suggest that $Ca^{2+}$-antagonists do not affect EDR and the inhibitory effect of $Ca^{2+}$ results from influencing the action of EDRF on vascular smooth muscle, whereas that of $La^{3+}$ results from its action on the release of EDRF from endothelial cells.

• 한국전문물리치료학회지
• /
• 제27권1호
• /
• pp.70-77
• /
• 2020

Background: Neck pain can be caused by any structure in the neck, such as intervertebral discs, ligaments, muscles, facet joints, dura mater, and nerve roots. The hyoid bone is a structure that is also related to head and neck posture, neck movement and pain, but there are no studies on hyoid deviation, neck pain, and range of motion (ROM). Objects: The purpose of this study was to investigate the effect of fascia relaxation and mobilization of the hyoid bone on the ROM, pain, and lateral deviation of the hyoid bone. Methods: Twenty-five patients with neck pain identified by the lateral motion test (10 males [35.13 ± 7.67 years, 172.69 ± 3.90 cm, 78.77 ± 6.96 kg] and 15 females [35.13 ± 10.05 years, 161.11 ± 4.09 cm, 52.59 ± 2.98 kg]) was chosen randomly. Baseline values for pain, neck ROM, and lateral deviation in the hyoid bone were recorded using a visual analogue scale (VAS), goniometer, and tape measure. Then, each patient was treated with hyoid fascia relaxation and mobilization, and all results were recorded after intervention. Comparison of the results before and after intervention was analyzed using paird t-test (p < 0.05). Results: Right rotation, extension, VAS, and rotational asymmetry statistically significant differences (p < 0.05). Right rotation and extension increased ROM, rotational asymmetry ratio and VAS decreased. However, there was no significant difference in flexion, left rotation, center point (p > 0.05). Conclusion: Fascia relaxation and hyoid mobilization could improve the ROM of cervical extension, asymmetry of the cervical rotation and neck pain.

• Corrosion Science and Technology
• /
• 제11권2호
• /
• pp.48-55
• /
• 2012

Clamping force of a high strength bolt is reduced by a certain period of time after the initial set-up. In case of special treatments on faying surfaces such as protective coating, clamping force is relaxed more severely. Tests for slip critical joints subject to various faying surface parameters were conducted. Five different surface treatments were tested including mill scale surface, blast surface, rust surface and coated surfaces. Each specimen was composed of F10T M20 of high strength bolts and steel plates. Based on the result of slip coefficient test, blast treatment surface showed 0.59, rust treatment surface showed 0.54 and inorganic zinc treatment surface exhibited 0.44. Clean mill treatment surface and red lead paint treatment surface were 0.23, 0.21 respectively. It is identified that the slip coefficient in Korean structural design guide should be determined for various surface conditions. Subsequently from long term relaxation test of ASTM A 490 high strength bolts, relaxation of no-coated surfaces such as blast, clean mill, rust treatment, the loss of initial clamping load was 10.5%, 13.6% and 7.9% for 1,000 hours, while the loss of initial clamping force was reached as 15.0%, 18.7% more than the required redundancy 10% in case of inorganic zinc and red lead painted treatment. It is required that the limit of relaxation on coated faying surface should be established separately for various surfaces.

• 한국식품과학회지
• /
• 제41권3호
• /
• pp.292-295
• /
• 2009

국내산 콩 25종과 중국산 콩 24종을 일반성분 분석을 실시하고 10MHz pulsed NMR의 relaxation pattern을 이용하여 농산물의 원산지에 따른 차이를 구명하고 이에 따른 정확하고 신속한 원산지 판별이 가능하도록 하였다. 국내산과 중국산 콩의 일반성분 분석을 실시한 결과 수분, 지방, 회분에 유의적 차이가 없었고 조단백질 함량에서는 국내산이 중국산보다 높았다. T1-IR을 이용하여 측정한 NMR값은 중국산 콩이 국내산 콩보다 짧은 이완시간을 갖는 것으로 나타났으며(p<0.0001), $T_1-Sr$도 마찬가지였다(p<0.0001). 횡이완시간 중 $T_2-SE$의 값은 국내산이 중국산보다 높게 나타났다(t-test, p<0.0086). $T_1-IR$과 $T_1-SR$ 두 개의 변수를 이용하여 판별식을 작성한 경우 국내산과 중국산 모두 96%의 판별 가능성을 보였으며, $T_1-IR$과 $T_1-SR$, $T_2-SE$, $T_2-CPMG$의 모든 변수를 이용하여 판별한 결과 국내산과 중국산 콩의 판별 정확성이 100%로 나타났다. 이 연구를 통하여 저자장 NMR을 이용하여 국내산과 중국산 콩을 유의적 선별해 낼 수 있는 가능성을 확인하였다.

• 한국해양공학회:학술대회논문집
• /
• 한국해양공학회 2003년도 추계학술대회 논문집
• /
• pp.167-170
• /
• 2003

Thermal elastic-plastic analysis was performed to assess the initial residual stress distribution of welded joints considering temperature dependent material properties. The test model was the idealized boxing fillet specimen, frequently appeared in the joints of longitudinal and transverse members of ship structure. Residual stress relaxations due to external loads were analyzed by subsequent elastic-plastic analysis considering loading and unloading steps, and the characteristics of residual stress relaxations were discussed with the levels of external loads. Additionally, to define the fatigue life of crack initiation and propagation, the S-N data for each crack length were appraised.

• 한국소성가공학회:학술대회논문집
• /
• 한국소성가공학회 2003년도 춘계학술대회논문집
• /
• pp.195-198
• /
• 2003

High temperature deformation and softening behavior of SAF 2507 super duplex stainless steel (SDSS) has been investigated in connection with an FEM analysis of hot forging process. Flow curves at various strain rates and temperatures were determined first from compression tests, and the kinetics of dynamic recrystallization were also formulated through the analysis of load relaxation test results. Applying the dynamic materials and proposed by Prasad et al., it was possible to determine the characteristics of deformation behavior effectively at a given condition of deformation. Constitutive relations and recrystallization kinetics formulated from the test results were then implemented in a commercial FEM code. Flow stress compensation formulated upon the volume fraction of recrystallization and adiabatic heating was found to improve significantly the FEA solutions in predicting the forming load and the distribution of recrystallized volume fraction after forging.

• 한국소성가공학회:학술대회논문집
• /
• 한국소성가공학회 2003년도 춘계학술대회논문집
• /
• pp.295-298
• /
• 2003

High temperature deformation behavior of a Ti-Al intermetallic compound has been investigated. Specimens with a near gamma and a lamella structures were obtained by performing heat treatment at 1200 and 1330$^{\circ}C$, respectively, for 24 hr and stabilized at 900$^{\circ}C$ for 4 hr followed by air cooling. A series of load relaxation tests has been conducted on these samples at temperatures ranging from 850 to 950$^{\circ}C$ to construct flow curves in the strain rate range from 10$\^$-6//s to 10$\^$-3//s. Strain hardening was observed even at the temperature of 950$^{\circ}C$ in both the near gamma and the lamella structures. Further aging treatment for 12 hr at test temperatures has found to cause no softening in both microstructures.

• Management Science and Financial Engineering
• /
• 제11권2호
• /
• pp.85-103
• /
• 2005

In this paper, we consider the routing and wavelength assignment problem in survivable WDM transport network without wavelength conversion. We assume the single-link failure and a path protection scheme in optical layer. When a physical network and a set of working paths are given, the problem is to select a link-disjoint protection path for each working path and assign a wavelength for each working and protection path. We give an integer programming formulation of the problem and propose an algorithm to solve it. Though the formulation has exponentially many variables, we solve the linear programming relaxation of it by using column generation technique. We devise a branch-and price algorithm to solve the column generation problem. After solving the linear programming relaxation, we apply a variable fixing procedure combined with the column generation to get an integral solution. We test the proposed algorithm on some randomly generated data and test results show that the algorithm gives very good solutions.

• 한국소성가공학회:학술대회논문집
• /
• 한국소성가공학회 2004년도 춘계학술대회 논문집
• /
• pp.186-189
• /
• 2004

Although magnesium has high potential for structural material due to the lightweight and high specific strength, the structural application has been limited by the low ductility at room temperature. The reason of the poor ductility is few activated slip systems of magnesium (HCP structure) during deformation. As temperature increases, however, additional non-basal slip systems are incorporated to exhibit higher ductility comparable to aluminum. In the present study, a series of tensile tests of Mg-Al alloy has been carried out to study deformation behavior with temperature variation. Analysis of load relaxation test results based on internal variable approach gave information about relationship between the micromechanical character and corresponding deformation behavior of magnesium. Especially, the material parameter, p representing dislocation permeability through barriers was altered from 0.1 to 0.15 as the non-basal slip systems were activated at high temperature.