• Journal of the Korean Society for Precision Engineering
• /
• v.31 no.2
• /
• pp.125-131
• /
• 2014

Winding is an integral operation in almost every roll-to-roll continuous process and center-winding is suitable and general scheme in the winding system. However, the internal stresses within center-wound rolls can cause damage such as buckling, spoking, cinching, etc. It is therefore necessary to analyze the relationship between taper tension in winding section and internal stress distribution within center-wound roll to prevent the winding failure. In this study, an optimal taper tension control method with parabolic taper tension profile for producing high quality wound roll was developed. The new logic was designed from analyzing the winding mechanism by using the stress model in center-wound rolls. The performance of the proposed taper tension profile was verified experimentally.

• Journal of Advanced Marine Engineering and Technology
• /
• v.29 no.6
• /
• pp.701-706
• /
• 2005

Pipes, tubes. and tubular sections with external transverse high fins have been used extensively for heating cooling, and degumidifying air and other gases. This work was performed to investigate an air side heat transfer charactieristics of minichannel with tension wound transverse fin. This estimate was confirmed conversion heat capacity the air side surface area enlargement and heat transfer charactieristics performed available inlet tube side hot water mass flux or outlet tube side air frontal air velocity. The most suitable tension wound transverse finned minichannel was measured extremely low in air side pressure drop and fin effectiveness $3.3\~4.4$. The pressure drop $0.9\~2.8Pa$ was ranged frontal air velocity $0.5\~1.2m/s$. It is also appeared that heat transfer in air side could be better conversion heat area which has been increased $330\%$ of heat capacity compared with the bare tube.

• Journal of the Korean Society for Precision Engineering
• /
• v.32 no.12
• /
• pp.1011-1016
• /
• 2015

In a roll-to-roll continuous system, winding is one of the most important processes since it determines the quality of the final manufactured products such as flexible film and printed electronic devices. Since an adequate winding tension can reduce the incidence of the defects that are derived from the inner stress of the wound roll such as starring and telescoping, it is necessary to determine the optimal taper-tension profile. In this study, an algorithm for the setting of an optimal taper-tension profile in consideration of the residual stress in the wound roll is suggested; furthermore, the algorithm was adjusted for the determination of an optimal taper-tension profile regarding the winding process of $10{\mu}m$ polypropylene (PP) film. As a result of the algorithm-generated, optimal taper-tension profile, the residual stress and radial stress in a PP wound roll were decreased to 27.37 % and 40.05 % (mean value), respectively.

• Journal of Trauma and Injury
• /
• v.37 no.2
• /
• pp.147-150
• /
• 2024

This case report describes the management of a 51-year-old female patient who arrived at the emergency room with a stab wound to the upper right chest. Immediate medical interventions were undertaken, including blood transfusions and endotracheal intubation. To prevent tension and control bleeding, gauze packing was applied directly through the large open wound. Further surgical exploration identified a laceration in the lung, necessitating a right upper lobe resection. Postoperatively, the patient's vital signs stabilized, and she was subsequently discharged without complications. This case highlights the decision-making process in selecting between an emergency department thoracotomy and an operating room thoracotomy for patients with penetrating chest trauma. It also illustrates the role of gauze packing in managing tension and hemorrhage. In summary, gauze packing can be an effective interim measure for stabilizing patients with traumatic injuries, unstable vital signs, and large open chest wounds, particularly when a chest tube is already in place, to prevent tension and facilitate bleeding control prior to surgical intervention.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2007.06a
• /
• pp.83-84
• /
• 2007

• Journal of the Korean Burn Society
• /
• v.22 no.2
• /
• pp.58-65
• /
• 2019

Wound caused by high-tension electrical burns is difficult to manage because the wound is deep and complex. The wound is progressively necrotic due to microvascular injury resulting in deep tissue exposure. So, coverage of the wound at the entry point and the exit point is cumbersome, often requiring flap coverage. We experienced a case of one patient for peroneal artery perforator free flap coverage on the palm of the right hand of the entry point of electrical burn. The left foot wound of electrical exit point was covered by full thickness skin graft. Also a small wound was on the left side of the lower back was the exit point of electrical burn. The lower back wound was healed and recurred repeatedly after burn. On postburn day 6 month, through the radiologic exam, metal shadow was identified in the left gluteus muscle forming chronic sinus. We explored the wound of sinus and a foreign body was identified in the sac as multi braid wires thin as hair. According to the patient's past history, we suspected that the back wound was caused by electrical burn injury through the wires.

• Journal of the Korean Society for Precision Engineering
• /
• v.15 no.2
• /
• pp.45-52
• /
• 1998

The contact roll is often used to regulate the winding tension as well as the entrained air in a wound roll by adjusting the contact force to the winding roll. But the contact force generated by other rolls, like assistant nip rolls, in a winding(or roll changing) process may act as disturbance to the control of the winding tension. In this paper, the mechanism of a roll change process is analysed. Ana, the behavior of the contact and the nip rolls are mathematically modeled. A nonlinear PID(NPID) controller is designed to control the winding tension and to reject the effect of disturbance generated by the nip roll on the winding tension variation. Computer simulation study showed that the performance of the suggested NPID controller is improved compared with that of the PID controller in controlling the winding tension and in rejecting the effect of the disturbance.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1996.11a
• /
• pp.748-753
• /
• 1996

The contact roll is often used to regulate the winding tension as well as the entrained air in a wound roli by adjusting the contact force to the winding roll. But the contact force generated by other rolls, like assistant nip rolls, in a winding(or roll changing) process may act as disturbance to the control of the winding tension. In this paper, the mechanism of a roll change process is analyzed. And, the behavior of the contact and the assistant nip rolls are mathematically modeled. A nonlinear PID(NPID) controller is designed to control the winding tension and to reject the effect of disturbance generated by the assistant nip roll on the winding tension variation. Computer simulation study showed that the performance of the suggested NPID controller is improved compared with that of the PID controller in con trolling the winding tension and in rejecting the effect of the disturbance.

• Archives of Plastic Surgery
• /
• v.39 no.5
• /
• pp.457-462
• /
• 2012

Background The elasticity of the back skin of the rat reduced the tension around wounds during the wound healing process in that region, and thus activates wound contraction. The authors proposed two skin fixation methods using readily available materials to decrease the influence of wound contraction on wound healing and designed an experiment to determine their effects. Methods The authors made 36 skin wounds on the backs of 18 rats, and they divided them into three groups. Each group was treated with three different kinds of dressing materials, each with different skin fixing characteristics. Group A was a control group. Group B and group C were dressed by the first and the second skin fixation method. We measured the areas of the wounds post-surgically and calculated the wound area reduction rates. Results The two skin fixation methods both reduced the effect of wound contraction compared to the control group. Each of the two methods had different outcomes in reducing wound contraction. Conclusions The experiment demonstrated significant differences among the wound areas and the wound area reduction rates of the three groups as a result of differences in the degree of wound contraction. To obtain accurate results from wound healing experiments, appropriate skin fixation methods must be adopted.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.46 no.5
• /
• pp.361-366
• /
• 2020

Guided bone regeneration (GBR) is a surgical procedure that utilizes bone grafts with barrier membranes to reconstruct small defects around dental implants. This procedure is commonly deployed on dehiscence or fenestration defects ≥2 mm, and mixing with autogenous bone is recommended on larger defects. Tension-free primary closure is a critical factor to prevent wound dehiscence, which is critical cause of GBR failure. A barrier membrane should be rigidly fixed without mobility. If the barrier is exposed, closed monitoring should be utilized to prevent secondary infection.