Amount Of Stress Reduction Research Articles

Direct Investment Casting For Pattern Developed By Desktop 3D Printer

Development of RP technologies has encouraged rapid study on portable 3D Printer in which there are varieties of portable 3D printer machines in market. Nevertheless, less reports regarding its consumption of fabricated pattern to be used in direct investment casting. This study has focused on development of ABS P400 pattern in terms of collapsibility behaviour which has capability to be used as sacrificial pattern in direct investment casting. In addition, the internal built structures have been built into two designs such as square and polygon patterns respectively. The patterns were constructed in semi cylindrical geometry which comes with one side opened and one side closed together wrapped with 4 mm of ceramic shell. This experimental were conducted with variation temperature starting from 30°C until 150°C with increment of 5°C per minutes while for the numerical simulation, the temperature selected was between 30 °C to 120 °C with 10 °C increment per minutes. Moreover, the observation was made that glass transition temperature, Tg happened near 110°C. It was observed that the shell cracking happened on the ceramic shell. Other than that, the polygon pattern tends to collapsed inwardly rather than square pattern during the burnout process. A result also shows that, there is significant amount of stress reduction on both square and polygon which was 45 % respectively. Besides that, the amount of strain on pattern itself has shown about 9% reduction. Moreover, there is greater difference in terms of ceramic shell strain reduction which was 38% for square and polygon patterns respectively. Lastly, there is 11 % reduction of strain when compared square and polygon in terms of axial strain on ceramic shell

Effect of progressive muscular relaxation exercises versus transcutaneous electrical nerve stimulation on tension headache: A comparative study

Abstract Tension-type headache (TTH) is most frequent among all types of headaches. According to the International Headache Classification Subcommittee of the International Headache Society (2004), TTH occurs in 30–78% of the population. Progressive muscular relaxation exercises have been shown to reduce TTH, and home-based relaxation programmes can result in significant improvement in headaches. Transcutaneous electrical nerve stimulation (TENS) is a method of electrical stimulation that primarily aims to provide a degree of symptomatic pain relief by exciting sensory nerves and stimulating either the pain gate mechanisms or the opioid systems. The objective of this study was to compare between the effects of progressive muscular relaxation exercises and TENS on pain intensity and stress in people with TTH. Thirty patients with TTH were allocated to either Group A or Group B. Group A practised progressive muscular relaxation exercise, whereas Group B received TENS. In the latter group, TENS electrodes were placed bilaterally either on the head at the site of pain or on the occiput. The treatment was carried out for 15 minutes a day, for 7 days. Patients were assessed for pain intensity (Visual Analogue Scale) and level of stress (Lakaev Academic Stress Response Scale) before and after the intervention period. The results showed that progressive muscular relaxation exercises were effective in reducing pain as well as stress ( p p p = 0.233). Between-group analysis revealed that there was no statistically significant difference in reduction of pain between the two groups ( p = 0.595), but the amount of stress reduction in Group A ( p = 0.002) was significantly more than that in Group B. In conclusion, progressive muscular relaxation exercises were more effective in reducing stress level than TENS in patients with TTH. The effect on pain reduction was similar between the two treatment methods.

Stress Build-Up during Multilayer Welding with Novel Martensitic Filler Materials*

Abstract Controlling the level of mostly detrimental residual stresses already during the welding process would be highly attractive as time and cost consuming post processing may be prevented. Innovative Low Transformation Temperature (LTT-) filler materials are specially designed for controlling weld residual stresses by means of adjusted martensite formation already during welding. Numerous publications can be found on this issue, but they provide only little insight into the interaction between martensite formation and resulting welding residual stresses. Within this study a component weld test was performed in a special large-scale testing facility. In-situ load analysis revealed that the amount of stress reduction during deposition of the individual weld runs is dependent on the weld volume undergoing phase transformation related to the shrinking volume. The residual stresses found after welding show that the desired residual stress control by using LTT alloys is sensitive to welding boundary conditions (i. e. weld geometry, plate thickness) and to be evaluated separately for varying weld scenarios.

Effect of Martensitic Phase Transformation on Stress Build-up during Multilayer Welding

Innovative low transformation temperature (LTT) welding filler materials are featuring a characteristic chemical composition which favors the formation of martensite at comparatively low temperatures. This permits deliberate adjustment of welding residual stresses. Even though numerous investigations can be found in the literature on this issue, they provide only little insight into the interaction between phase transformation and resulting welding residual stresses. For this purpose, a component weld test was performed in a special large-scale testing facility. The results illustrate that the desired residual stress control by using LTT alloys is actually feasible. With increasing shrinkage restraint, however, higher tensile residual stresses are formed in transverse direction of the weld. By contrast, the residual stress level in longitudinal weld direction is nearly independent of the restraint conditions. On-line stress analysis revealed that the amount of stress reduction during cooling of the individual weld runs is dependent on the weld volume undergoing phase transformation. Overall, evidence was furnished that the approach of residual stress engineering by LTT alloys is suitable even in the case of large-scale multilayer welding.

SP1-105 The application of collaborative counselling model to manage stress and coping in infertile women undergoing IVF: a randomised clinical trial

IntroductionInfertility is an acute life crisis with psychological consequences which may last for an indeterminate length of time and one of the greatest challenges of infertile women is coping with...

森林セラピーロードにおける森林散策路の景観評価と心理面における森林浴効果との関連性

Forest occupies most of Japanese domain. Nevertheless there is not enough area of flat forest park. Thus a forest footpath is an important element as the space of contact of city people and forest. Yet,a research which analyzed the relationship evaluation of forest footpath and the relaxation effect of walking in the forest is not enough. Thus,this paper analyzed the relationship between the relaxation effect of forest bathing by POMS and the evaluation of the forest footpath. The evaluation of the forest footpath : A number of photographs of favorable space during walk, an error in assessing time and distance in the walk. In the result, amount of stress reduction and vitality increase of the participants are likely to be improved in the footpath which was as follow. : Higher diversity of forest landscape, easier walking road, many attractive scene.In addition, The number of pictures of the good scenery is related to the value of the stress response before walking and frequency forest trail.

Fatigue Crack Growth Comparison between Sleeved and Non-Sleeved Pipeline

A section of gas pipeline containing dormant stress corrosion cracks was removed from service and pressure cycled, and the crack growth from fatigue was measured. Crack growth was able to be conservatively calculated by BS7910. Parts of the pipeline section had composite repair sleeves placed over it in order to compare fatigue crack growth of sleeved and unsleeved cracks. Sleeved cracks consistently showed less crack growth than unsleeved cracks; this is believed to be due to reduced hoop stresses in the pipe under the composite repair sleeve and reduced crack opening. A simple model of the sleeve repair was developed which was consistent with the measured strains in the pipe. The application pressure of the sleeve repair affects the amount of stress reduction in the pipe and the amount of crack growth experienced. Two possible methods of repair of SCC affected pipelines were validated by this work.

The Effect of Music on Decreasing Arousal Due to Stress: A Meta-Analysis

A meta-analytic review of research articles using music to decrease arousal due to stress was conducted on 22 quantitative studies. Results demonstrated that music alone and music assisted relaxation techniques significantly decreased arousal (d = +.67). Further analysis of each study revealed that the amount of stress reduction was significantly different when considering age, type of stress, music assisted relaxation technique, musical preference, previous music experience, and type of intervention. Implications and suggestions for future research are discussed.

A Study of Mechanical Stress Relief (MSR) Treatment of Residual Stresses for One-Pass Submerged Arc Welding of V-Grooved Mild Steel Plate

The heat-transfer and thermal stress distributions in one-pass submerged arc welding (SAW) were numerically determined using the finite element method (FEM) for a V-grooved rectangular steel plate in which the weld preparation was filled during welding. A two-dimensional non-linear heat-transfer analysis was performed for a transverse section of the plate. This was followed by a thermo-elasto-plastic transient thermal stress analysis, assuming plane strain to be constant for the same model section. The same stress model was used to simulate a mechanical stress relief (MSR) treatment of the plate. This has frequently been used in the fabrication of large pressure vessels instead of post-weld heat treatment (PWHT). In this way its effect in reducing the residual stress in the welded plate was investigated. MSR was simulated by enforcing a constant displacement loading in the welding direction. The solution of the thermal stress analysis showed that it was possible for the residual stress around the weld centre to be accurately estimated by accurate modelling of the dilution of the filler metal in the fused zone of the base metal. The conclusion derived from the MSR simulation was that it could quantitatively predict the effect of reducing the residual stress in the welded plate. Only limited experimental data were available. The mechanism of stress reduction was plastic straining in regions of high residual stress. The amount of stress reduction at the weld centre had a linear relationship to the magnitude of the external stress relieving load. The numerical results for the MSR simulation agreed fairly well with experimental ones obtained from the MSR test performed on a welded plate.

Residual Stresses and Their Redistribution During Annealing of a Girth-Butt Welded Thin-Walled Pipe

The redistribution of calculated welding stresses during different post weld heat treatments (PWHT) is numerically investigated for a girth-butt welded thin-walled pipe made of a micro-alloyed carbon manganese steel. A finite element analysis with assumed rotational symmetry is performed. The influence of creep, relaxation and phase transformations is included. The amount of stress reduction is found to be mainly controlled by the holding temperature. Most of this reduction was observed to occur during the end of the heating period where the transient stresses followed the fall of the yield stress with temperature.

Dynamic recovery during and after steady state deformation of Al-11wt%Zn

Cylindrical specimens of Al-11wt%Zn were deformed at constant stress and at 523 K in tensile creep tests. The stress dependence of the steady state deformation rate ge s , was determined from stress change tests, ge s shows an exponential stress dependence in the stress range above 10 MPa. The steady state values of the dislocation density in the subgrain interior ( ρ i ) and of the subgrain size were determined by means of transmission electron microscopy. The fundamental equation of steady state deformation ge s = ( b M) Agr − was tested by independent measurement of ge s and gr −. A is of the order of the subgrain size. gr − was determined from the recovery behavior of the dislocation density immediately after steady state deformation. The shape of the recovery curves did not depend on type and amount of stress reduction but was strongly dependent on ge s . These results were confirmed by measurements of the transient creep behavior after reloading the specimens with the initial load. For the exact determination of gr − an interpolation method was used, which is based on the decrease of ρ i during stress relaxation. The shape of the recovery curves and the stress dependence of ge s . A and gr − suggest that recovery during and immediately after steady state deformation is of dynamic nature.