• 제목/요약/키워드: lateral branch

검색결과 206건 처리시간 0.021초

Evaluation of seismic reliability and multi level response reduction factor (R factor) for eccentric braced frames with vertical links

  • Mohsenian, Vahid;Mortezaei, Alireza
    • Earthquakes and Structures
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    • 제14권6호
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    • pp.537-549
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    • 2018
  • Using vertical links in eccentric braced frames is one of the best passive structural control approaches due to its effectiveness and practicality advantages. However, in spite of the subject importance there are limited studies which evaluate the seismic reliability and response reduction factor (R-factor) in this system. Therefore, the present study has been conducted to improve the current understanding about failure mechanism in the structural systems equipped with vertical links. For this purpose, following definition of demand and capacity response reduction factors, these parameters are computed for three different buildings (4, 8 and 12 stories) equipped with this system. In this regards, pushover and incremental dynamic analysis have been employed, and seismic reliability as well as multi-level response reduction factor according to the seismic demand and capacity of the frames have been derived. Based on the results, this system demonstrates high ductility and seismic energy dissipation capacity, and using the response reduction factor as high as 8 also provides acceptable reliability for the frame in the moderate and high earthquake intensities. This system can be used in original buildings as lateral load resisting system in addition to seismic rehabilitation of the existing buildings.

단족지 신전근 도상 피판에 의한 족부 및 족관절부의 연부조직 수복 (The Extensor Digitorum Brevis Muscle Island Flap for Soft Tissue Loss Around the Ankle and Distal Foot)

  • 최수중;전병혁
    • Archives of Reconstructive Microsurgery
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    • 제14권2호
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    • pp.131-137
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    • 2005
  • The extensor digitorum brevis (EDB) muscle island flap is a reliable, safe method for coverage of foot and ankle. There are many variation in approach such as curvilinear, zigzag, L-shaped or vertical longitudinal incision for exposure of the EDB muscle. These approaches use only single incision excluding the distal incision for exposure of the distal tendon. Since dorsalis pedis artery vascular bundle and sinus tarsi branch of the lateral tarsal artery both requires careful dissection, single incision alone may cause not only difficulty in exposure but also skin sloughing at donor site. So we tried to modify the approach into two parallel longitudinal incision, one for dorsalis pedis vascular bundle and the other for sinus tarsi branch exposure. The author treated 9 patient with EDB muscle flap. We used single incision in six patients, and two parallel incision in three patients. All the flap survived. In two parallel incision group, dissection was more easy and rapid. So we would like to suggest that two parallel longitudinal incision approach is better method than the single incision technique for exposure of the EDB muscle flap.

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Numerical study on the performance of corrugated steel shear walls

  • Edalati, S.A.;Yadollahi, Y.;Pakar, I.;Emadi, A.;Bayat, M.
    • Wind and Structures
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    • 제19권4호
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    • pp.405-420
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    • 2014
  • This paper examines the nonlinear behaviour of corrugated steel plate shear walls under lateral pushover load. One of the innovations in these types of walls which have used in recent years is the use of the corrugated steel shear walls rather un-stiffness plates. In the last decades many experimental studies have been done on the on the corrugated steel shear walls. A finite element analysis that includes both material and geometric nonlinearities is employed for the investigation. A comparison is made between the behaviour of steel shear walls with sinusoidal corrugated plate and trapezoidal corrugated plate. The effects of parameters such as the thickness of the corrugated plate, the corrugation depth in the corrugated plates and the corrugation length of the infill of the corrugated plates, are investigated. The results of this study have demonstrated that in the wall with constant dimensions, the trapezoidal plates have higher energy dissipation, ductility and ultimate bearing than sinusoidal waves, while decreasing the steel material consumption.

Chondrocutaneous posterior auricular artery perforator free flap for single-stage reconstruction of the nasal tip: a case report

  • Lee, Jun Yong;Seo, Jeong Hwa;Jung, Sung-No;Seo, Bommie Florence
    • 대한두개안면성형외과학회지
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    • 제22권6호
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    • pp.337-340
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    • 2021
  • Full-thickness nasal tip reconstruction is a challenging process that requires provision of ample skin and soft tissue, and intricate cartilage structure that maintains its architecture in the long term. In this report, we describe reconstruction of a full-thickness nasal tip and ala defect using a posterior auricular artery perforator based chondrocutaneous free flap. The flap consisted of two lay ers of skin covering conchal cartilage, and was based on a perforating branch of the posterior auricular artery. A superficial vein was secured at the posterior margin. The donor perforator was anastomosed to a perforating branch of the lateral nasal artery. The superficial vein was connected to a superficial vein of the surrounding soft tissue. The donor healed well after primary closure. The flap survived without complications, and the contour of the nasal rim was sustained at follow-up 6 months later. As opposed to combined composite reconstructions using a free cartilage graft together with a small free flap or pedicled nasolabial flap, the posterior auricular artery perforator free flap encompasses all required tissue types, and is similar in contour to the alar area. This flap is a useful option in single-stage reconstruction of nasal composite defects.

Effect of connection stiffness on the earthquake-induced progressive collapse

  • Ali, Seyedkazemi;Mohammad Motamedi, Hour
    • Earthquakes and Structures
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    • 제23권6호
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    • pp.503-515
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    • 2022
  • Global or partial damage to a structure due to the failure of gravity or lateral load-bearing elements is called progressive collapse. In the present study, the alternate load path (ALP) method introduced by GSA and UFC 4-023-03 guidelines is used to evaluate the progressive collapse in special steel moment-resisting frame (SMRF) buildings. It was assumed that the progressive collapse is due to the earthquake force and its effects after the removal of the elements still remain on the structures. Therefore, nonlinear dynamic time history analysis employing 7 earthquake records is used to investigate this phenomenon. Internal and external column removal scenarios are investigated and the stiffness of the connections is changed from semi-rigid to rigid. The results of the analysis performed in the OpenSees program show that the loss of the bearing capacity of an exterior column due to a seismic event and the occurrence of progressive collapse can increase the inter-story drift of the structure with semi-rigid connections by more than 50% and make the structure unable to satisfy the life safety performance level. Furthermore, connection stiffness severely affects the redistribution of forces and moments in the adjacent elements of the removed column.

Anatomical study of divergences in facial artery endings

  • Yasser Ayish Alharbi
    • Anatomy and Cell Biology
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    • 제56권2호
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    • pp.211-218
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    • 2023
  • Despite several studies focusing on the facial arteries variable courses, the findings have significantly differed. The divergent findings have made it increasingly challenging to establish consistent correlations. Thus, as a vital artery, the facial artery is prone to numerous variations, which makes the identification of the variations vital to clinical practice, particularly for the orofacial and rhinoplastic surgery, and the increasingly selective chemotherapy procedures. The present research uses angiography images for analysis in studying the bilateral facial artery variations noted in patients undergoing carotid angiography for the evaluation of congenital anomalies, cerebral vascular malformations, and intra-arterial procedures. Conventional angiography was used, as it is a vital assessment tool that helps in the assessment of variations in the facial arteries and is suitable in evaluating smaller vascular anatomy, due to the perfect spatial resolution and portrayal of vascular anatomy. Thus, rather than normal ending of the facial artery as an angular artery, the study disclosed that in certain instances, the artery termination took the form of a superior labial artery with a small lateral nasal artery branch located closer to the midline compared to the normal cases. Also, the study has disclosed a conspicuous pre-masseteric branch with small branches originating from the infraorbital artery and providing potential compensation for the facial artery's shortness. Regardless of the infrequency of such variations, it is vital that they are considered during the performance of any facial surgical procedure.

Foot Reconstruction by Reverse Island Medial Plantar Flap Based on the Lateral Plantar Vessel

  • Moon, Min-Cheol;Oh, Suk-Joon;Cha, Jeong-Ho;Kim, Yoo-Jeong;Koh, Sung-Hoon
    • Archives of Plastic Surgery
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    • 제37권2호
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    • pp.137-142
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    • 2010
  • Purpose: Tumor ablation and traumatic intractable ulceration of the plantar surface of the foot results in skin and soft tissue defects of the weight-bearing sole. Simple skin grafting is not sufficient for reconstruction of the weight-bearing areas. Instead, the island medial plantar flap (instep flap) and distally-based island medial plantar flap was used for proper reconstruction of the weight bearing area. However, there are some disadvantages. In particular, an island medial plantar flap has a short pedicle limiting the mobility of the flap and the distally-based island medial plantar flap is based on a very small vessel. We investigated whether good results could be obtained using a reverse island medial plantar flap based on the lateral plantar vessel as a solution to the above limitations. Methods: Three patients with malignant melanoma were cared for in our tertiary hospital. The tumors involved the lateral forefoot, the postero-lateral heel, and the medial forefoot area. We designed and harvested the flap from the medial plantar area, dissected the lateral and medial plantar artery and vena comitans, and clamped and cut the vessel 1 cm proximal to the branch from the posterior tibial artery and vena comitans. The medial plantar nerve fascicles of these flaps anastomosed to the sural nerve, the 5th interdigital nerve, and the 1st interdigital nerve of each lesion. The donor sites were covered with skin grafting. Results: The mean age of the 3 subjects was 64.7 years (range, 57 - 70 years). Histologically, all cases were lentiginous malignant melanomas. The average size of the lesion was $5.3\;cm^2$. The average size of the flap was $33.1\;cm^2$. The flap color and circulation were intact during the early postoperative period. There was no evidence of flap necrosis, hematomas or infection. All patients had a normal gait after the surgery. Sensory return progressively improved. Conclusion: Use of an island medial plantar flap based on the lateral plantar vessel to the variable weight-bearing sole is a simple but useful procedure for the reconstruction of any difficult lesion of the weight-bearing sole.

외측 복사뼈 상부 근막-피부 섬피판을 이용한 발 및 발목관절 연부조직 결손의 재건 (Lateral Supramalleolar Fasciocutaneous Island Flap for Reconstruction of the Foot and Ankle Soft Tissue Defect)

  • 최재훈;김남균;최태현;이경석;김준식
    • Archives of Plastic Surgery
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    • 제33권6호
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    • pp.784-788
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    • 2006
  • Purpose: For the reconstruction of the ankle joint as well as the soft tissue defect in the distal lower leg, a free flap or a local flap has been used, and because of the condition of patients, if a complex microvascular surgery under general anesthesia could not be performed, it could be reconstructed by using the distally based lateral supramalleolar fascio-cutaneous island flap using the perforating branch of the peroneal artery in the ankle area. Methods: The study subjects were 4 male patients between 53 years and 73 years of age. 2 cases were tissue defect in the medial malleolus area due to systemic diseases such as gouty arthritis accompanied traffic accident, diabetes mellitus foot, atherosclerotic obliterans, etc., 1 case was the defect in the pretibia area, and 1 case was the defect underneath the lateral malleolus, which was reconstructed by the distally based lateral supramalleolar fascio-cutaneous island flap. The donor area was the skin harvested from the groin, and the full thickness skin graft was performed. The size of the flap varied from $4{\times}3cm$ to $9{\times}6cm$. As the flap border, the medial side was to the tibialis anterior tendon, the lateral side was to the fibula crest, and the proximal area was less than the fibula size. Results: The consequence is that, in total 4 cases, the congestion in the flap began from 12 hours after the surgery, and the progression of congestion was ceased on the 5th day after the surgery, and finally epidermal bulla and sloughing, partial necrosis was developed. After the end of necrosis, the defect area was reconstructed successfully by the second full thickness skin graft. Conclusions: Although the distally based lateral supramalleolar fascio-cutaneous island flap has the shortcoming of requiring the second skin graft, it has the advantages that it does not require a long complex microsurgery, the flap itself is thin, it is similar to the color of the skin in the recipient area, and it does not leave a big scar in the donor area. Therefore, it is thought that for the cases who could not undergo a long complex surgery due to systemic diseases or the cases of patients whose condition of the recipient area is not suitable for microsurgery, the lateral supramalleolar fascio-cutaneous island flap is very useful for the reconstruction of the distal lower leg and the ankle joint area.

Substantial Study on Constituent Elements of the Foot Taeyang Meridian Muscle in the Human Truncus

  • Park, Kyoung-Sik
    • 대한한의학회지
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    • 제30권3호
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    • pp.15-27
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    • 2009
  • Objective : This study was carried to identify the anatomical component of BMM (Foot Taeyang Meridian Muscle in the human truncus), and further to help the accurate application to real acupunctuation. Methods: The human truncus was stripped off in order to demonstrate muscles, nerves and other components, and to display the internal structure of the BMM, dividing into outer, middle, and inner parts. Results: The BMM in the human truncus is composed of muscles, nerves, ligaments etc. The internal composition of the BMM in the human truncus is as follows: 1. Muscle A. Outer layer: medial palpebral ligament, orbicularis oculi, frontalis, galea aponeurotica, occipitalis, trapezius, latissimus dorsi, thoracolumbar fascia, gluteus maximus. B. Middle layer: frontalis, semispinalis capitis, rhomboideus minor, serratus posterior superior, splenius cervicis, rhomboideus major, latissimus dorsi, serratus posterior inferior, levator ani. C. Inner layer: medial rectus, superior oblique, rectus capitis, spinalis, rotatores thoracis, longissimus, longissimus muscle tendon, longissimus muscle tendon, multifidus, rotatores lumbaris, lateral intertransversi, iliolumbaris, posterior sacroiliac ligament, iliocostalis, sacrotuberous ligament, sacrospinous ligament. 2. Nerve A. Outer layer: infratrochlear nerve, supraorbital n., supratrochlear n., temporal branch of facial n., auriculotemporal n., branch of greater occipital n., 3rd occipital n., dorsal ramus of 1st, 2nd, 3rd, 4th, 5th, 6th, 7th, 8th, 9th, 10th, 11th, 12th thoracic n., dorsal ramus of 1st, 2nd, 3rd, 4th, 5th lumbar n., dorsal ramus of 1st, 2nd, 3rd, 4th, 5th sacral n. B. Middle layer: accessory nerve, anicoccygeal n. C. Inner layer: branch of ophthalmic nerve, trochlear n., greater occipital n., coccygeal n., Conclusions : This study shows that BMM is composed of the muscle and the related nerves and there are some differences from already established studies from the viewpoint of constituent elements of BMM at the truncus, and also in aspect of substantial assay method. In human anatomy, there are some conceptional differences between terms (that is, nerves which control muscles of BMM and those which pass near by BMM).

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The effect of cyclic loading on the rubber bearing with slit damper devices based on finite element method

  • Saadatnia, Mahdi;Riahi, Hossein Tajmir;Izadinia, Mohsen
    • Earthquakes and Structures
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    • 제18권2호
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    • pp.215-222
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    • 2020
  • In this paper, slit steel rubber bearing is presented as an innovative seismic isolator device. In this type of isolator, slit steel damper is an energy dissipation device. Its advantages in comparison with that of the lead rubber bearing are its simplicity in manufacturing process and replacement of its yielding parts. Also, slit steel rubber bearing has the same ability to dissipate energy with smaller value of displacement. Using finite element method in ABAQUS software, a parametric study is done on the performance of this bearing. Three different kinds of isolator with three different values of strut width, 9, 12 and 15 mm, three values of thickness, 4, 6 and 8 mm and two steel types with different yield stress are assessed. Effects of these parameters on the performance characteristics of slit steel rubber bearing are studied. It is shown that by decreasing the thickness and strut width and by selecting the material with lower yield stress, values of effective stiffness, energy dissipation capacity and lateral force in the isolator reduce but equivalent viscous damping is not affected significantly. Thus, by choosing appropriate values for thickness, strut width and slit steel damper yield stress, an isolator with the desired behavior can be achieved. Finally, the performance of an 8-storey frame with the proposed isolator is compared with the same frame equipped with LRB. Results show that SSRB is successful in base shear reduction of structure in a different way from LRB.