• Title/Summary/Keyword: Stress Method

Search Result 10,658, Processing Time 0.042 seconds

POLYMERIZATION SHRINKAGE OF COMPOSITE RESINS CURED BY VARIABLE LIGHT INTENSITIES (가변 광도 중합에 따른 복합레진의 중합수축에 관한 연구)

  • Lim, Mi-Young;Cho, Kyung-Mo;Hong, Chan-Ui
    • Restorative Dentistry and Endodontics
    • /
    • v.32 no.1
    • /
    • pp.28-36
    • /
    • 2007
  • The purpose of this study was to compare the effect of exponential curing method with conventional curing and soft start curing method on polymerization shrinkage of composite resins. Three brands of composite resins (Synergy Duo Shade, Z250, Filtek Supreme) and three brands of light curing units (Spectrum 800, Elipar Highlight, Elipar Trilight) were used. 40 seconds curing time was given. The shrinkage was measured using linometer for 90 seconds. The effect of time on polymerization shrinkage was analysed by one-way ANOVA and the effect of curing modes and materials on polymerization shrinkage at the time of 90s were analysed by two-way ANOVA. The shrinkage ratios at the time of 20s to 90s were taken and analysed the same way. The results were as follows : 1. All the groups except Supreme shrank almost within 20s Supreme cured by soft start and exponential curing had no further shrinkage after 30s (p < 0.05). 2. Statistical analysis revealed that polymerization shrinkage varied among materials (p = 0.000) and curing modes (p = 0.003). There was no significant interaction between material and curing mode. 3. The groups cured by exponential curing showed the statistically lower polymerization shrinkage at 90s than the groups cured by conventional curing and soft start curing (p < 0.05). 4. The initial shrinkage ratios of soft start and exponential curing were statistically lower than conventional curing (p < 0.05). From this study, the use of low initial light intensities may reduce the polymerization rate and, as a result, reduce the stress of polymerization shrinkage.

Qualitative Study on Experiences of Responding to COVID-19 of Therapists in Long-term Care Hospitals (요양병원 치료사의 코로나19 대응 경험에 대한 질적 연구)

  • Bae, Won-Jin;Park, Ju-Young
    • Journal of Korea Entertainment Industry Association
    • /
    • v.15 no.4
    • /
    • pp.337-347
    • /
    • 2021
  • This study is a qualitative study conducted to provide basic data for therapists working in long-term care hospitals to improve their countermeasure strategies for new infectious diseases and improvement of the treatment room infection management system, and to help therapists understand their infection management work. Colaizzi's phenomenological research method was applied as the research method. Telephone interviews were conducted with nine occupational therapists and physical therapists working in nursing hospitals. The contents of the interview were recorded with the consent of the study subjects, and additional confirmation was received by email. The recorded content was analyzed after transcription, and the meaning and nature of the experience coping with COVID-19 were described. The content was organized into 6 themes, 17 main meaning and 49 meaning units. In accordance with the COVID-19 situation, the infection control system has been strengthened by reinforcing infection control education in nursing hospitals, practicing infection control, and supervising infection control outside business hours. It was found that the treatment environment was changed due to the restriction of treatment activities by practicing distancing in the treatment room, adjusting rest and meal times during working hours, and strengthening infection control. In addition, the therapist's role has been expanded and the paradigm of treatment has changed, such as considering the untact intervention, and they have experienced cohort quarantine, pre-tested for COVID-19, vaccinations, and side effects from COVID-19. However, due to the infection work, the therapist's work burden is increased, and the person is experiencing fear, depression, and work stress from the spread of COVID-19. They were also aware of the need for nursing hospital care personnel support, such as guaranteeing rest after vaccination and providing infection control tools and equipment. The results of this study are expected to be used as basic data for human and physical support for the development of infectious disease response strategy programs in nursing hospital treatment rooms and for infection control in nursing hospitals.

Reinforcing Effects around Face of Soil-Tunnel by Crown & Face-Reinforcing - Large Scale Model Testing (천단 및 막장면 수평보강에 의한 토사터널 보강효과 - 실대형실험)

  • Kwon Oh-Yeob;Choi Yong-Ki;Woo Sang-Baik;Shin Jong-Ho
    • Journal of the Korean Geotechnical Society
    • /
    • v.22 no.6
    • /
    • pp.71-82
    • /
    • 2006
  • One of the most popular pre-reinforcement methods of tunnel heading in cohesionless soils would be the fore-polling of grouted pipes, known as RPUM (reinforced protective umbrella method) or UAM (umbrella arch method). This technique allows safe excavation even in poor ground conditions by creating longitudinal arch parallel to the tunnel axis as the tunnel advances. Some previous studies on the reinforcing effects have been performed using numerical methods and/or laboratory-based small scale model tests. The complexity of boundary conditions imposes difficulties in representing the tunnelling procedure in laboratory tests and theoretical approaches. Full-scale study to identify reinforcing effects of the tunnel heading has rarely been carried out so far. In this study, a large scale model testing for a tunnel in granular soils was performed. Reinforcing patterns considered are four cases, Non-Reinforced, Crown-Reinforced, Crown & Face-Reinforced, and Face-Reinforced. The behavior of ground and pipes as reinforcing member were fully measured as the surcharge pressure applied. The influences of reinforcing pattern, pipe length, and face reinforcement were investigated in terms of stress and displacement. It is revealed that only the Face-Reinforced has decreased sufficiently both vertical settlement in tunnel heading and horizontal displacement on the face. Vertical stresses along the tunnel axis were concentrated in tunnel heading from the test results, so the heading should be reinforced before tunnel advancing. Most of maximum axial forces and bending moments for Crown-reinforced were measured at 0.75D from the face. Also it should be recommended that the minimum length of the pipe is more than l.0D for crown reinforcement.

Effect of Organizational Support Perception on Intrinsic Job Motivation : Verification of the Causal Effects of Work-Family Conflict and Work-Family Balance (조직지원인식이 내재적 직무동기에 미치는 영향 : 일-가정 갈등 및 일-가정 균형의 인과관계 효과 검증)

  • Yoo, Joon-soo;Kang, Chang-wan
    • Journal of Venture Innovation
    • /
    • v.6 no.1
    • /
    • pp.181-198
    • /
    • 2023
  • This study aims to analyze the influence of organizational support perception of workers in medical institutions on intrinsic job motivation, and to check whether there is significance in the mediating effect of work-family conflict and work-family balance factors in this process. The results of empirical analysis through the questionnaire are as follows. First, it was confirmed that organizational support recognition had a significant positive effect on work-family balance as well as intrinsic job motivation, and work-family balance had a significant positive effect on intrinsic job motivation. Second, it was confirmed that organizational support recognition had a significant negative effect on work-family conflict, but work-family conflict had no significant influence on intrinsic job motivation. Third, in order to reduce job stress for medical institution workers, it is necessary to reduce job intensity, assign appropriate workload for ability. And in order to improve manpower operation and job efficiency, Job training and staffing in the right place are needed. Fourth, in order to improve positive organizational support perception and intrinsic job motivation, It is necessary to induce long-term service by providing support and institutional devices to increase attachment to the current job and recognize organizational problems as their own problems with various incentive systems. The limitations of this study and future research directions are as follows. First, it is believed that an expanded analysis of medical institution workers nationwide by region, gender, medical institution, academic, and income will not only provide more valuable results, but also evaluate the quality of medical services. Second, it is necessary to reflect the impact of the work-life balance support system on each employee depending on the environmental uncertainty or degree of competition in the hospital to which medical institution workers belong. Third, organizational support perception will be recognized differently depending on organizational culture and organizational type, and organizational size and work characteristics, working years, and work types, so it is necessary to reflect this. Fourth, it is necessary to analyze various new personnel management techniques such as hospital's organizational structure, job design, organizational support method, motivational approach, and personnel evaluation method in line with the recent change in the government's medical institution policy and the global business environment. It is also considered important to analyze by reflecting recent and near future medical trends.

Analysis of Quantitative Indices in Tl-201 Myocardial Perfusion SPECT: Comparison of 4DM, QPS, and ECT Program (Tl-201 심근 관류 SPECT에서 4DM, QPS, ECT 프로그램의 정량적 지표 비교 분석)

  • Lee, Dong-Hun;Shim, Dong-Oh;Yoo, Hee-Jae
    • The Korean Journal of Nuclear Medicine Technology
    • /
    • v.13 no.3
    • /
    • pp.67-75
    • /
    • 2009
  • Purpose: As to the analytical method of data, the various programs in which it is used for the quantitative rating of the Tl-201 myocardial perfusion SPECT are reported that there is a difference. Therefore, the measured value error of the mutual program is expected to be generated even if the quantitative analysis is made against data of the same patient. Using quantitative index that able to represent myocardial perfusion defect level, we aimed to determine correlation among three myocardial perfusion analysis programs 4DM (4DMSPECT), QPS (Quantitative Perfusion SPECT), ECT (Emory Cardiac Toolbox) that be used generally in most departments of Nuclear Medicine. Materials and Methods: We analyzed the 145 patients who were examined by Tl-201 gated myocardial perfusion SPECT in department of nuclear medicine at Asan Mediacal Center from December 1th 2008 to February 14th 2008. We sorted as normal group and abnormal group. Normal group consist of 80 patients (Male/Female=38/42, age:$65.1{\pm}9.9$) who have low possibility of cardiovascular disease. And abnormal group consist of 65 patients (Male/Female=45/20, age:$63.0{\pm}8.7$) who were diagnosed cardiovascular disease with reversible perfusion defect or fixed perfusion defect through myocardial perfusion SPECT results. Using the 4DM, QPS, and ECT programs, the total defect extent (TDE) such as LAD, LCX, RCA and the summed stress score (SSS) have been analysed for their correlations and statistical comparison with the paried t-test for the quantitative indices analysed from each group. Results: The correlation of 4DM:QPS, QPS:ECT, ECT:4DM each group result from 145 patients is 0.84, 0.86, 0.82 at SSS, 0.87, 0.84, 0.87 at TDE, and both index showed good correlation. In paired t-test and Bland-Altman analysis results showed no statistically significant difference in the comparison of QPS:ECT at the mean SSS and TDE, 4DM:QPS, ECT:4DM comparative analysis results showed statistically significant difference at SSS and TDE index. The correlation of 4DM:QPS, QPS:ECT, ECT:4DM program results from abnormal group (65 patients) is 0.72, 0.72, 0.70 at SSS and 0.77, 0.70, 0.77 at TDE and TDE and SSS has a good correlation. In abnormal group, paired t-test and Bland-Altman analysis results showed no statistically significant difference at QPS:ECT SSS (p=0.89) and TDE (p=0.23) comparison, 4DM:QPS, ECT:4DM comparative analysis results showed statistically significant difference at SSS and TDE index (p<0.01). In normal group (80 patients), paired t-test and Bland-Altman analysis results showed no statistically significant difference at QPS:ECT SSS (p=0.95) and TDE (p=0.73) comparison. And 4DM:QPS, ECT:4DM comparative analysis results showed statistically significant difference at SSS and TDE index (p<0.01). Conclusions: The perfusion defect of the Tl-201 myocardial perfusion SPECT was analyzed in not only the patient in whom it has the cardiovascular disease but also the patient in whom the possibility of the cardiovascular disease is few. In the comparison of the all group research, the mean of the TDE and SSS, 4DM was lower than QPS and ECT progrms. Each program showed good correlation and the results showed statistically significant difference. However, in this way, it is determined to be compatible about the analysis value in which the large-scale side between the programs uses each program a difference in a clinical in the Bland-Altman analyzed result in spite of the good correlation and cannot use. but, this analyzed result will be able to be usefully used as the reference material for the clinical read and is expected.

  • PDF

Respiratory Gas Exchange and Ventilatory Functions at Maximal Exercise (최대운동시의 호흡성 가스교환 및 환기기능)

  • Cho, Yong-Keun;Jung, Tae-Hoon
    • Tuberculosis and Respiratory Diseases
    • /
    • v.42 no.6
    • /
    • pp.900-912
    • /
    • 1995
  • Background: Although graded exercise stress tests are widely used for the evaluation of cardiorespiratory performance, normal standards on respiratory gas exchange and ventilatory functions at maximal exercise in Koreans have not been well established. The purpose of this study is to provide reference values on these by sex and age, along with derivation of some of their prediction equations. Method: Symptom-limited maximal exercise test was carried out by Bruce protocol in 1,000 healthy adults consisting of 603 males and 397 females, aged 20~66 years. Among them VC, $FEV_1$ and MVV were also determined in 885 cases. All the subjects were members of a health center, excluding athletes. During the exercise, subjects were allowed to hold on to front hand rail of the treadmill for safety purpose. Results: The $VO_2\;max/m^2$, $VCO_2\;max/m^2$ and $V_E\;max/m^2$ were greater in males than in females and decreased with age. The RR max in men and women was similar but decreased slightly with age. The $V_T$ max was markedly greater in men but showed no significant changes with age in either gender. The mean of $V_T$ max/VC, $V_E$ max/MVV and BR revealed that there were considerable ventilatory reserves at maximal exercise even in older females. The regression equations of the cardinal parameters obtained using exercise time(ET, min), age(A, yr), height(Ht, cm), weight(W, kg), sex(S, 0=male; 1=female), VC(L), $FEV_1$(L) and $V_E$ max(L) as variables are as follows: $VO_2\;max/m^2$(L/min)=1.449+0.073 ET-0.007A+0.010W-0.006Ht-0.209S, $VCO_2\;max/m^2$(L/min)=1.672+0.063ET-0.008A+0.010W-0.005Ht-0.319S, VE max/$m^2$(L/min)=58.161+1.503ET-0.315A-9.871S or VE max/$m^2$(L/min)=47.873+6.548 $FEV_1$-5.715 S, and VT max(L)=1.497+0.223VC-0.493S. Conclusion: Respiratory gas exchange and ventilatory variables at maximal exercise were studied in 1,000 non-athletes by Bruce protocol. During exercise, the subjects were allowed to hold on to hand rail of the treadmill for safety purpose. We feel that our results would provide ideal target values for patients and healthy individuals to be achieved, since our study subjects were members of a health center whose physical fitness levels were presumably higher than ordinary population.

  • PDF

A literal study on the Gu-Chang (구창의 문헌연구)

  • Jung Han Sol;Park Jong Hoon;Ryuk Sang Won;Lee Kwang Gyu
    • Journal of Physiology & Pathology in Korean Medicine
    • /
    • v.16 no.1
    • /
    • pp.32-44
    • /
    • 2002
  • Gu-Chang is a disorder characterized by recurring ulcers confined to the oral mucosa. Despite much clinical and research attention, the causes remain poorly understood. In this paper, we will compare Gu-Chang with Recurrent Aphthous Stomatitis(RAS) in order to know what is the similiarity between Gu-Chang and RAS. So we will arrange various oriental and western medical literatures which are important. As a result of arrangement of the causes, symptoms and therapys of Gu-Chang, we can conclude through the studies as follows. 1. The etiologies of Gu-chang are following. In the Sthenia syndrome, there are evil heat of external factor, heat of heart and spleen, insomnia, heat of upper warmer, stress and diet, heat of lung and heart, excessive heat of upper warmer, inappropriate food intake, heat conveyance of organ, heat of stomach merdian, moistured heat of spleen and stomach and stasis of liver energy. In the Asthenia syndrome, there are deficiency of stomach energy, deficiency of upper warmer leading to heat, deficiency of middle warmer leading to cold, deficiency of lower warmer leading to heat, deficiency of middle energy, deficiency of blood, decreased fire and deficiency of soil, yin fire of lower warmer, deficiency of heart yin, deficiency of spleen yin and deficiency of qi and blood. 2. In western medicine the causes of RAS is presumed as local, microbial, systemic, nutritional, genetic, immunologic factors. 3. Once Gu-chang is compared with RAS, in the deficiency of yin leading to hyperactivity of fire, deficiency of yin leading to floating of fire and stasis of liver energy, recurring of Gu-chang is similar to RAS. Although recurring of Gu-chang due to tripple warmer of excessive fire has no recurrance, since there are the degree of Pain, site of lesion, dysphagia etc, it is similar to major RAS. It is may be believed that Sthenia Gu-chang is similar to major RAS, shape of recurring, site of lesion, degrree of Pain and white color of Asthenia Gu-chang are similar to minor RAS, but there is no similarity concerning herpes RAS in the literatures that describe the symptoms. 4. Generally, the treatment of Gu-chang is divided into Asthenia and Sthenia Syndrome. The method of cure to Sthenia syndrome is heat cleaning and purge fire, Asthenia syndrome is nourish yin to lower and adverse rising energy and strength the middle warmer and benefit vital energy. 5. Following is the medication for Sthenia syndrome. Heat of heart and spleen is Do Jok San, Yang Gyek San, Juk Yup Suk Go Tang, evil heat of external factor is Yang Gyek San Ga Gam, Stasis of liver energy is Chong Wi Fae Dok Yum, moistured heat of spleen and stomach is Chong Gi Sam Syep Tang. The medication for Asthenia Syndrome is following. Deficiency of upper warmer leading to heat is Bo Jung Ik Gi Tang, deficiency of middle warmer leading to cold is Bu Ja Lee Jung Tang, deficiency of lower warmer leading to heat is Yuk Mi Ji Hwang Tang, deficiency of yin leading to hyperactivity of fire is Ji Baek Ji Hwang Hwan, deficiency of yin leading to floating of fire is Lee Jung Tang Ga Bu Ja Medicine for external use were Yang Suk San, Boo Wyen San, Rok Po San, Yoo Hwa San ate. 6. In western medicine, there is no specific treatment for RAS, and management strategies depend on dinical presentation and symptoms and includes antibiotics, oral rinses, glucocorticoids, immunomodulatory drugs, vitamines, analgesics, laser and antiviral agents.

Immediate effects of cigarette smoking on exercise in young adult smokers (젊은 성인 흡연자에게 흡연이 운동능에 미치는 즉시효과)

  • Park, In Won;Koh, Hyung Ki;Kang, Yoon Jung;Choi, Jae Sun;Yoo, Jee Hoon;Shin, Jong Wook;Lim, Seong-Yong;Choi, Byoung Whui;Seo, Seung Cheon;Na, Moon Jun;Hue, Sung Ho
    • Tuberculosis and Respiratory Diseases
    • /
    • v.44 no.1
    • /
    • pp.154-161
    • /
    • 1997
  • Background : Although the long term adverse effects of cigarette smoking on health are well known, the acute possible detrimental effects of smoking on pulmonary or cardiovascular function, especially when these systems are stressed by the metabolic demands of exercise, have not been well studied The purpose of this study is to determine the acute action of cigarette smoking on cardiopulmonary function under stress. Method : Twenty -one healthy smoking subjects were studied. Before exrecise testing, history taking, physical examination and baseline studies, including CBC, chest PA, PFT and EKG, were done. The subjects performed an incremental bicycle exercise test to exhaustion on two occasions, one without smoking and the other after smoking 5 cigarettes/h for 2 hours. All indices of P.F.T. and bicycle ergometry were compared between before and after smoking. Results : 1. $VO_2$max and $O_2$ pulse showed significant decrease in smoking day. 2. Although there were no significant differences, anaerobic threshold showed a tendency of decrease and HRmax showed that of increase in smoking day. 3. P.F.T. and respiratory indices showed no significant change io smoking day. Conclusion : Cigarette smoking has immediate adverse effect, especially on the cardiovascular system rather than the respiratory system. These results would be due to the effect of elevated HbCO and/or impaired blood flow in response to the exercise stimulus.

  • PDF

A Study on the Development of Curriculum for the Department of Fisheries Processing in Fisheries Junior College (전문대학(專門大學) 수산가공과(水產加工科) 교육과정(敎育科程) 개선(改善)에 관한 연구(硏究))

  • Seong, Dae-Hwan;Choi, Jong-Duck;Kim, Jeong-Gyun
    • Journal of Fisheries and Marine Sciences Education
    • /
    • v.2 no.1
    • /
    • pp.15-28
    • /
    • 1989
  • The aim of this study is to improve the curriculum for the fisheries processing department in fisheries junior college in Korea. For this study, questionaries to alumani and students of the fisheries processing department of Tong-Yeong Fisheries Junior College are made and meeting materials of professors concerned and some leading managers of food processing company. In addition, curricula of the department food processing in two year or four year colleges both domestic and foreign are refered. The results obtained can be shown as follows ; 1. Subjects of the standard laboratory work designated by the Ministry of Education and required at the practical techique examination for the food precessing technitian certificates were chosen to student compulsorily, and the other subjects necessary to acquistion of the techniques were opened in this course electively. 2. The food processing departments in nationwide twenty-three junior college open seventy-eight major subject courses. Among those subjects, we choose the subjects only related to fisheries processing ones to put stress on the features of fisheries processing department. 3. The selected courses in improved curricula of this work are total 119 credits spending 142 class-hour per weeks. Detailed curricula are as follows ; liberal arts are consist of 13 subjects-24 credits, essential major subjects 12 subjects-32 credits, elective subjects 24 subject-56 credits and interdisciplinary subjects 2 subjects-5 credits. 4. The linking system of industrial-educational co-operation have to be established to fulfil the field practice, and legal basis should be made to support these educational circumstances. 5. To make sure a live education in junior college, present education terms should be extended more than 1 year, and improved textbook, method of experiment, practice and evaluation continuously.

  • PDF

THE EFFECT OF CYCLIC LOADING ON THE RETENTIVE STRENGTH OF FULL VENEER CROWNS (반복 하중이 Full veneer crown의 유지력에 미치는 영향에 관한 연구)

  • Kim, Ki-Youn;Lee, Sun-Hyung;Chung, Hun-Young;Yang, Jae-Ho;Heo, Seong-Joo
    • The Journal of Korean Academy of Prosthodontics
    • /
    • v.38 no.5
    • /
    • pp.583-594
    • /
    • 2000
  • Dislodgement of a crown or extension bridge and the loosening of a retainer of a bridge is a serious clinical problem in fixed restoration. Generally these problems are considered to be associated with deformation of the restoration. During biting, the restoration is subjected to complex forces and deforms considerably within the limit of its elasticity. Deformation of the restoration under the occlusal force induces excessive stress in the cement film, which then leads to the cement fracture. Such a fracture may eventually cause loss of the restoration. Because most of the past retention tests for full veneer crown were done without fatigue loading, they were not exactly simulating intraoral environment. And the purpose of this study was to evaluate the effect of cyclic cantilever loading on the retentive strength of full veneer crowns depending on different type of cements and taper of prepared abutment. Steel dies with $8^{\circ}\;or\;16^{\circ}$ convergence angle were fabricated through milling and crowns with the same method. These dies and crowns were divided into 8 groups. Group 1 : $16^{\circ}$ taper die, cementation with zinc phosphate cement, without loading Group 2 : $16^{\circ}$ taper die, cementation with zinc phosphate cement, with loading Group 3 : $8^{\circ}$ taper die, cementation with zinc phosphate cement, without loading Group 4 : $8^{\circ}$ taper die, cementation with zinc phosphate cement, with loading Group 5 : $16^{\circ}$ taper die, cementation with Panavia 21, without loading Group 6 : $16^{\circ}$ taper die, cementation with Panavia 21, with loading Group 7 : $8^{\circ}$ taper die, cementation with Panavia 21 without loading Group 8 : $8^{\circ}$ taper die, cementation with Panavia 21, with loading After checking the fit of die and crown, the luting surface of dies and inner surface of crowns were air-abraded for 10 seconds. The crowns were cemented to the dies, with cements mixed according to the manufacturer's recommendations. A static load of 5kg was then applied for 10 minutes with static loading device. Twenty-four hours later, group 1, 3, 5, 7 were only thermocycled, group 2, 4, 6, 8 were subjected to cyclic loading after thermocycling. Retentive tests were performed on the Instron machine. From the finding of this study, the following conclusions were obtained 1. Panavia 21 showed significantly higher retentive strength than zinc phosphate cement for all groups (p<0.05). 2. There was a significant difference in the retentive strength between $8^{\circ}\;and\;16^{\circ}$ taper for zinc phosphate cement(p<0.05), but no significant difference for Panavia 21 (p>0.05). 3. Cyclic loading significantly decreased the retentive strength for all groups(p<0.05). 4. For zinc phosphate cement, there was 35% reduction of the retentive strength after loading in the $16^{\circ}$ taper die, 25% in the $8^{\circ}$ taper die, and for Panavia 21, 21% in the $16^{\circ}$ taper die, 18% in the $8^{\circ}$ taper die.

  • PDF