• Title/Summary/Keyword: Repair materials and methods

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Conservation Status, Construction Type and Stability Considerations for Fortress Wall in Hongjuupseong (Town Wall) of Hongseong, Korea (홍성 홍주읍성 성벽의 보존상태 및 축성유형과 안정성 고찰)

  • Park, Junhyoung;Lee, Chanhee
    • Korean Journal of Heritage: History & Science
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    • v.51 no.3
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    • pp.4-31
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    • 2018
  • It is difficult to ascertain exactly when the Hongjuupseong (Town Wall) was first constructed, due to it had undergone several times of repair and maintenance works since it was piled up newly in 1415, when the first year of the reign of King Munjong (the 5th King of the Joseon Dynasty). Parts of its walls were demolished during the Japanese occupation, leaving the wall as it is today. Hongseong region is also susceptible to historical earthquakes for geological reasons. There have been records of earthquakes, such as the ones in 1978 and 1979 having magnitudes of 5.0 and 4.0, respectively, which left part of the walls collapsed. Again, in 2010, heavy rainfall destroyed another part of the wall. The fortress walls of the Hongjuupseong comprise various rocks, types of facing, building methods, and filling materials, according to sections. Moreover, the remaining wall parts were reused in repair works, and characteristics of each period are reflected vertically in the wall. Therefore, based on the vertical distribution of the walls, the Hongjuupseong was divided into type I, type II, and type III, according to building types. The walls consist mainly of coarse-grained granites, but, clearly different types of rocks were used for varying types of walls. The bottom of the wall shows a mixed variety of rocks and natural and split stones, whereas the center is made up mostly of coarse-grained granites. For repairs, pink feldspar granites was used, but it was different from the rock variety utilized for Suguji and Joyangmun Gate. Deterioration types to the wall can be categorized into bulging, protrusion of stones, missing stones at the basement, separation of framework, fissure and fragmentation, basement instability, and structural deformation. Manually and light-wave measurements were used to check the amount and direction of behavior of the fortress walls. A manual measurement revealed the sections that were undergoing structural deformation. Compared with the result of the light-wave measurement, the two monitoring methods proved correlational. As a result, the two measuring methods can be used complementarily for the long-term conservation and management of the wall. Additionally, the measurement system must be maintained, managed, and improved for the stability of the Hongjuupseong. The measurement of Nammunji indicated continuing changes in behavior due to collapse and rainfall. It can be greatly presumed that accumulated changes over the long period reached the threshold due to concentrated rainfall and subsequent behavioral irregularities, leading to the walls' collapse. Based on the findings, suggestions of the six grades of management from 0 to 5 have been made, to manage the Hongjuupseong more effectively. The applied suggested grade system of 501.9 m (61.10%) was assessed to grade 1, 29.5 m (3.77%) to grade 2, 10.4 m (1.33%) to grade 3, 241.2 m (30.80%) and grade 4. The sections with grade 4 concentrated around the west of Honghwamun Gate and the east of the battlement, which must be monitored regularly in preparation for a potential emergency. The six-staged management grade system is cyclical, where after performing repair and maintenance works through a comprehensive stability review, the section returned to grade 0. It is necessary to monitor thoroughly and evaluate grades on a regular basis.

A study on the status of asbestos use on ships (선박에서의 석면 사용실태 연구)

  • Park, Seung-Hyun;Chung, Eun-Kyo;Kwon, Ji-Woon;Kim, Kab-Bae;Chung, Kwang-Jae;Yi, Gwang-Yong;Shin, Jung-Ah;Lee, In-Seop;Kang, Seong-Kyu
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.21 no.3
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    • pp.123-127
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    • 2011
  • Objectives: The purpose of this study was to investigate the status of asbestos-containing materials (ACMs) used on ships and to consider measures for preventing worker exposure to asbestos fibers. Methods: A total of 17 ships including 16 ships under repair and a ship under construction at shipyards in Korea were investigated. Bulk samples were collected from suspected ACMs on engine exhaust pipes, boiler steam pipes, generator exhaust pipes, and etc. in ships in order to identify the presence of ACMs. Types and contents of asbestos were determined using polarized light microscopy (PLM). Results: ACMs were found from 14 ships out of 17 ships investigated. Only chrysotile asbestos was found from all samples. ACMs were mainly found from samples collected at the exhaust pipes of the engine, generator and incinerator, and boiler steam pipes where exhaust gases or steam of high temperature pass through. In most cases, types of ACMs were asbestos-containing fabrics such as asbestos tape. Friable ACMs were also found in some cases. Use of ACMs on ships was relevant to built time and owner of the ships rather than type and tonnage of the ships. Conclusions: ACMs were found from most ships built prior to 2000s. Therefore, measures for preventing asbestos-related diseases such as preparation of asbestos map on the ship and installation of warning signs, hazard communication with workers (ship-repairing workers, engine room workers and etc.), and follow-up for worker's health management are needed.

Arthroscopic Treatment of Meniscal Cyst (슬관절 반월상 연골 낭종의 관절경적 치료)

  • Bae, Dae-Kyung;Yoon, Kyung-Ho;Kwon, Oh-Soo;Shin, Dong-Jun;Im, Yang-Jin
    • Journal of the Korean Arthroscopy Society
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    • v.6 no.1
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    • pp.14-20
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    • 2002
  • Purpose : To analyze the clinical result of the arthroscopic decompression of meniscal cyst and meniscus resection or repair of meniscus tear. Materials and Methods : From April 1994 and October 2001, 19 patients with diagnosis of meniscal cyst associated with tears of the meniscus were treated by arthroscopic meniscal resection or repair with decompression of the cyst. The mean age was 39.8 years(range, 22-58years). The follow-up period ranged from 3 months to 36 months with an average of 18 months. Seven of 19 patients had tenderness over the joint line with palpable mass. Treatment consists of arthroscopic resection or repair of meniscal tear with decompression of the cyst through transmeniscal approach. Open excision of cyst was performed in one case. Clinical evaluation was performed using Lysholm knee score and Tegner activity. All cases were executed proper treatment using arthroscopy. Results : Twelve cysts involved the lateral meniscus$(64\%)$ and seven cysts were on medial cyst$(36\%)$. Most of lateral meniscal cysts were located in anterior one-third and medial meniscal cyst were on posterior one-third. Meniscal tear were observed in seventeen cases$(89.5\%)$ and most tears were horizontal$(79\%)$. Preoperative symptom disappeared and no cyst recurrences were observed at last follow-up(mean follow-up: 18 months). Conclusion : Meniscal cysts involved lateral side in $64\%$ and most of them were associated with meniscus tear$(89.5\%)$ which consists of mainly horizontal component$(79\%)$.

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Anchor Hole Augmentation with Bone Cement in Arthroscopic Rotator Cuff Repair (관절경적 회전근 개 봉합술에서 골 시멘트를 이용한 봉합 나사 구멍 보강술)

  • Lee, Ho-Min;Tae, Suk-Kee;Park, Jeong-Min
    • Clinics in Shoulder and Elbow
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    • v.13 no.2
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    • pp.237-243
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    • 2010
  • Purpose: In arthroscopic rotator cuff repair, the crucial step is secure fixation of Anchor to bone. However, osteoporosis of the tuberosity is frequently encountered in old patients, and can cause insecure fixation of anchors. The Aim of our study was to introduce a technique for anchor hole augmentation with bone cement when fixation failure of an anchor occurs, and to investigate the outcome. Materials and methods: Among 223 rotator cuff repairs performed between 2005 and 2009, anchor hole augmentation with polymethylmethacrylate was performed in 15 cases (all females; mean age of 65 years: range 49~77). Bone cement was injected into the anchor hole in a thick fluid state and the procedure was repeated to make a pot-like cement mantle. The anchor was inserted into the cement mantle while the cement hardened. The outcome was investigated, on average, at 16 months (6~32). Results: Radiographs showed cystic changes of the tuberosity. On follow-up radiographs and MRI, a change in the cement mantle was not noted. The final average UCLA score was 31 (28~35); 6 had excellent, 8 good and 1 fair results (p=0.008). Age-sex matched Constants score was 90 (74~98) (p=0.008). Conclusion: Anchor hole augmentation with bone cement is useful when fixation failure of an anchor is encountered due to bone atrophy. Anchor hole augmentation with bone cement does not negatively influence the outcome.

Investigation on Products and Regulation of Flexible Adhesive Rubber Asphalt Type Sealant for the Development of Korea-China Joint Standard (점착유연형 고무아스팔트계 씰재의 한중 공동 품질관리 규정 개발을 위한 제품 및 기술기준 현황 조사)

  • An, Ki-Won;Kim, Dong-Bum;Choi, Su-Young;He, Xing-Yang;Oh, Sang-Keun
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.7 no.4
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    • pp.323-332
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    • 2019
  • Non-curable rubberized polymer asphalt waterproof coating materials in Korea and China are manufactured without advanced quality control techniques and common standard, And they are exposed consistent water leakage problems. Import and application of Korean waterproofing products and installation methods is difficult in the present situation as the Chinese standard(JC/T 2428) is different in nature with the Korean counterpart products, And quality assurance is inevitable based on mutual standards. In order to resolve this issue, alternatives such as using standards provided by the ISO (International Organization for Standardization) are generally employed, but there is no such ISO standard as a waterproof material for non-curable rubberized polymer asphalt material. Furthermore, it is unreasonable to develop the ISO standard for rubber asphalt seals for exchange in terms of time and cost. This study proposes that the establishment of a quality standard that can be applied for both countries will be required via an joint international standard that outlines the properties of materials if applied in mutual trade exchange.

The Wound Healing Effect of PDRN(polydeoxyribonucleotide) Material on Full Thickness Skin Defect in the Mouse (흰 쥐의 전층피부 결손에 대한 PDRN (polydeoxyribonucleotide) 제재의 창상치유 효과)

  • Kim, Yo-Han;Lee, Jong-Hoon;Min, Kyung-Hee;Hong, Sung-Hee;Lee, Won-Mi;Jun, Jin-Hyun
    • Archives of Plastic Surgery
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    • v.37 no.3
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    • pp.220-226
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    • 2010
  • Purpose: Many topical agents had been used for burn or wound treatment. An awareness of topical agents on various aspects of wound healing permits the clinician to choose the most appropriate material to advantageously control the wound process and final results. Although polydeoxyribonucleotide (PDRN) was used as a tissue repair stimulating agent in a number of human diseases, such as ulcers and burns, its wound healing effects were largely unreported. We aimed to compare the woundhealing effects of PDRN and common dressing materials on full-thickness skin defect in the mouse. Methods: Full-thickness skin defects were made on the back of mice (N=60). The mice were divided into the following 4 groups according to the dressing used for the wounds: group O (Polydeoxyribonucleotide cream), group I (Polydeoxyribonucleotide solution), group M (Medifoam$^{(R)}$), and group G (dry gauze, control group). We analyzed the gross findings, wound sizes and histological findings for the groups. Results: The rate of wound size was decreased in order of group I, group O, group M and group G. The histological findings revealed that the I group showed more reepithelialization and granulation tissue formation and less inflammatory cell infiltration than the other materials. The grade score of wound healing was increased in order of group I, group O, group M and group G. Conclusion: PDRN applicated wound dressings can be used for treating a full-thickness skin defect wounds. Considering its superior efficacy in comparison to the efficacies of other wound dressings, PDRN soaked gauze dressing should be preferentially used for the treatment of fullthickness skin wounds.

Postoperative malocclusion after maxillofacial fracture management: a retrospective case study

  • Kim, Sang-Yun;Choi, Yong-Hoon;Kim, Young-Kyun
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.40
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    • pp.27.1-27.8
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    • 2018
  • Purpose: Various complications occur when a maxillofacial fracture is malunionized or improperly resolved. Malocclusion is the most common complication, followed by facial deformity, temporomandibular joint disorder (TMD), and neurological symptoms. The purpose of this study was to evaluate the dental treatment of postoperative complications after maxillofacial fracture. Materials and methods: In this study, nine patients with a postoperative complication after maxillofacial fracture who had been performed the initial operation from other units and were referred to the authors' department had been included. Of the nine patients, six had mandibular fractures, one had maxillary fractures, one had maxillary and mandibular complex fractures, and one had multiple facial fractures. All the patients had tooth fractures, dislocations, displacements, and alveolar bone fractures at the time of trauma, but complications occurred because none of the patients underwent preoperative and postoperative dental treatment. Malocclusion and TMD are the most common complications, followed by dental problems (pulp necrosis, tooth extrusion, osteomyelitis, etc.) due to improper treatment of teeth and alveolar bone injuries. The patients were referred to the department of dentistry to undergo treatment for the complications. One of the nine patients underwent orthognathic surgery for a severe open bite. Another patient underwent bone reconstruction using an iliac bone graft and vestibuloplasty with extensive bone loss. The other patients, who complained of moderate occlusal abnormalities and TMDs such as mouth-opening limitation, underwent occlusal treatment by prosthodontic repair and temporomandibular joint treatment instead of surgery. Results: One patient who underwent orthognathic surgery had complete loss of open bite and TMD after surgery. One patient who underwent reconstruction using an iliac bone graft had a good healing process. Other patients were treated with splint, injection, and physical therapy for mouth-opening limitation and temporomandibular joint pain. After treatment, the TMDs were resolved, but the remaining occlusal abnormalities were resolved with prosthetic restoration. Conclusions: Considering the severity of malocclusion and TMJ symptom and the feasibillity of reoperation, nonsurgical methods such as orthodontic and prosthodontic treatments and splint therapy can be used to manage the dental and TMD complication after the trauma surgery. However, reoperation needs to be strongly considered for severe malocclusion and TMD problem.

Sensitive and Noninvasive Detection of Aberrant SFRP2 and MGMT-B Methylation in Iranian Patients with Colon Polyps

  • Naini, M Alizade;Mokarram, P;Kavousipour, S;Zare, N;Atapour, A;Zarin, M Hassan;Mehrabani, G;Borji, M
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.4
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    • pp.2185-2193
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    • 2016
  • Background: The pathogenesis of sporadic colorectal cancer (CRC) is influenced by the patient genetic background and environmental factors. Based on prior understanding, these are classified in two major pathways of genetic instability. Microsatellite instability (MSI) and CPG island methylator phenotype (CIMP) are categorized as features of the hypermethylated prototype, and chromosomal instability (CIN) is known to be indicative of the non-hypermethylated category. Secreted frizzled related protein 2 (SFRP2), APC1A in WNT signaling pathway and the DNA repair gene, O6-methylguanine-DNA methyltransferase (MGMT), are frequently hypermethylated in colorectal cancer. Detection of methylated DNA as a biomarker by easy and inexpensive methods might improve the quality of life of patients with CRC via early detection of cancer or a precancerous condition. Aim: To evaluate the rate of SFRP2 and MGMT hypermethylation in both polyp tissue and serum of patients in south Iran as compared with matched control normal population corresponding samples. Materials and Methods: Methylation-specific PCR was used to detect hypermethylation in DNA extracted from 48 polypoid tissue samples and 25 healthy individuals. Results: Of total polyp samples, 89.5% had at least one promoter gene hypermethylation. The most frequent methylated locus was SFRP2 followed by MGMT-B (81.2 and 66.6 percent respectively). Serologic detection of hypermethylation was 95% sensitive as compared with polyp tissue. No hypermethylation was detected in normal tissue and serum and its detection in patients with polyps, especially of serrated type, was specific. Conclusions: Serologic investigation for detection of MGMT-B, SFRP2 hypermethylation could facilitate prioritization of high risk patients for colonoscopic polyp detection and excision.

Evaluation of Adhesion Characteristics of Crack Sealants Used in Asphalt Concrete Pavement (아스팔트 콘크리트 포장용 균열실링재의 부착특성 평가)

  • Lee, Jae-Jun;Kim, Seung-Hoon;Baek, Jong-Eun;Lim, Jae-Kyu;Kim, Yong-Joo
    • International Journal of Highway Engineering
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    • v.17 no.2
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    • pp.55-62
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    • 2015
  • Cracking is an inevitable fact of asphalt concrete pavements and plays a major role in pavement deterioration. Pavement cracking is one of the main factors determining the frequency and method of repair. Cracks can be treated with a number of preventative maintenance actions, including overlay surface treatments such as slurry sealing, crack sealing, or crack filling. Pavement cracks can show up as one or all of the following types: transverse, longitudinal, fatigue, block, reflective, edge, and slippage. Crack sealing is a frequently used pavement maintenance treatment because it significantly extends the pavement service life. However, crack sealant often fails prematurely due to a loss of adhesion. Because current test methods are mostly empirical and only provide a qualitative measure of the bond strength, they cannot accurately predict the adhesive failure of the sealant. This study introduces a laboratory test aimed at assessing the bonding of hot-poured crack sealant to the walls of pavement cracks. A pneumatic adhesion tensile testing instrument (PATTI) was adopted to measure the bonding strength of the hot-poured crack sealant as a function of the curing time and temperature. Based on a limited number of test results, the hot-poured crack sealants have very different bonding performances. Therefore, this test method can be proposed as part of a newly developed performance-based standard specification for hot-poured crack sealants for use in the future. PURPOSES : The purpose of this study was to evaluate both the adhesion and failure performance of a crack sealant as a function of its curing time and curing temperature. METHODS: A pneumatic adhesion tensile testing instrument (PATTI) was adopted to measure the adhesion performance of a crack sealant as a function of the curing time and curing temperature. RESULTS: With changes in the curing time, curing temperature, and sealant type, the bond strengths were found to be significantly different. Also, higher bond strengths were measured at lower temperatures. Different sealant types produced completely different bond strengths and failure behaviors. CONCLUSIONS: The bonding strength of an evaluated crack sealant was shown to differ depending on various factors. Two sealant types, which were composed of different raw materials, were shown to perform differently. The newly proposed test offers the possibility of evaluating and differentiating between different crack sealants. Based on alimited number of test results, this test method can be proposed as part of a newly developed performance-based standard specification for crack sealants or as part of a guideline for the selection of hot-poured crack sealant in the future.

Clinical and Arthroscopic Findings of Medial Meniscus Posterior Horn Insertion Tear (내측 반월상 연골판 후각 기시부 파열의 특징 및 관절경 소견)

  • Lee, Jun-Young;Kim, Dong-Hui;Ha, Sang-Ho;Lee, Sang-Hong;Gang, Joung-Hun
    • Journal of Korean Orthopaedic Sports Medicine
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    • v.8 no.1
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    • pp.33-38
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    • 2009
  • Purpose: We wanted to report the clinical characteristics and arthroscopic findings of radial tear in medial meniscus posterior horn insertion, commonly occurs in patient over middle age with documentary review. Materials and Methods: Retrograde study using hospital records was done to 40 cases in 40 patients who visited our hospital and had been performed knee arthroscopic surgery due to medial meniscus posterior horn insertion tear between January, 2005 to April, 2007. Seven cases were male and 33 cases were female with the mean age of 61 (range, 47-80). Trauma history, stage of arthritis, period between pain and operation, MRI findings, clinical symptoms and operation methods were evaluated. Results : Six cases had trauma history while 34 cases didn't. In simple x-ray, using Kellgren-Lawrence classification, 31 cases were between stage 0 and II while 9 cases were stage III. In arthroscopic exam, there were 17 cases of Outerbridge grade IV, 4 cases of grade III, 9 cases of grade II, 9 cases of grade I. The mean duration of pain was 5.3 months. In MRI, at least one finding of cleft in axial or coronal view or ghost sign in sagittal view was found in all cases. The shape of meniscus tears were blunt in 18 cases, transverse in 12 and degenerative tear in 10. Subtotal meniscectomy was performed in 16 cases, partial meniscectomy in 10 cases and meniscal repair in 14 cases. Conclusion : Medial meniscus posterior horn insertion tear occurs in patients over middle age is rarely related to trauma history but causes painful mechanical symptom and usually accompany arthritis. Meniscectomy can be done for the treatment but repair can be considered is some cases. Further study on the treatment result will be needed.

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