• Title/Summary/Keyword: Deterioration factors

Search Result 650, Processing Time 0.03 seconds

Post-Laminectomy Kyphosis in Patients with Cervical Ossification of the Posterior Longitudinal Ligament : Does It Cause Neurological Deterioration?

  • Cho, Won-Sang;Chung, Chun-Kee;Jahng, Tae-Ahn;Kim, Hyun-Jib
    • Journal of Korean Neurosurgical Society
    • /
    • v.43 no.6
    • /
    • pp.259-264
    • /
    • 2008
  • Objective : Total laminectomy (TL) is an effective surgical technique for the treatment of cervical ossification of the posterior longitudinal ligament (OPLL) along multiple levels. However, kyphosis and probable neurological deterioration have been frequently reported after laminectomy. We analyzed the changes in the cervical curvature after TL and subsequent changes in neurological status. Methods : We retrospectively reviewed the records of 14 patients who underwent TL for the treatment of cervical OPLL between Jan. 1998 and Dec. 2003. TL was selected according to the previously determined criteria. The curvature of the cervical spine was visualized on a lateral cervical spine X-ray and measured using Ishihara's Curvature Index (CI) before the operation and at the last follow-up examination. Perioperative neurological status was estimated using the modified Japanese Orthopedic Association score and the Improvement Rate (IR) at the same time as the images were evaluated. Results : The mean age of the patients was 57 years, the male/female ratio was 10:4, and the mean follow-up period was 41 months. The mean number of OPLL was 4.9, and the mean number of operated levels was also 4.9. The CI decreased after TL (p=0002), which was indicative of a kyphotic change. However, this kyphotic change showed no correlation with the length of the follow-up period, number of operated levels and preoperative CI. Neurological examination at the last follow-up showed an improved neurological status in all patients (p=0.001). There was no neurological deterioration in any case during the follow-up period. Moreover, there was no correlation between IR and the degree of kyphotic change. Postoperative complications, such as C5 radiculopathy and epidural bleeding, resolved spontaneously without neurological sequelae. Conclusion : Kyphotic change was observed in all but one patient who underwent TL for the treatment of cervical OPLL. However, we did not find any contributing factors to kyphosis or evidence of postoperative neurological deterioration.

Novel technique for preventing make up deterioration using performance materials

  • Miyazawa, Masakazu;Nishikata, Kazuhiro;Mohri, Kunihiko
    • Proceedings of the SCSK Conference
    • /
    • 2003.09b
    • /
    • pp.370-378
    • /
    • 2003
  • MFD (Make up Film Deterioration) is a gradual deterioration of applied make up and is a common problem experienced by most foundation users. Our investigation revealed that for 64% of all make up users MFD is their greatest consern is using foundations. Known that the primary cause of MFD is sebum secretion. We observed that the length of time prior to onset of MFD in people who produce high level of sebum varies significantly from person to person. This suggests that other factors besides quantity of sebum production can affect MFD. Control over this factor would, we believe, be key to developing longer-lasting makeups. We studied the relationship between MFD and skin surface conditions. Our study revealed that furrows on the skin surface affect MFD significantly. Sebum reaches the skin surface from sebaceous glands and flows along furrow on the skin. If there are many deep furrows, it takes longer for sebum to overflow. But if the furrows are few or shallow, sebum quickly overflows and spreads over the skin surface where it can degrade the make up film. Therefore even when the volume of sebum produced is the same, the rate of MFD will be different depending on the number and shape of the furrows. A longer-lasting foundation could be produced by matching personal skin condition, but this would be very difficult because individual variations in texture are very large. Therefore we approached the problem by attempting to impose sebum resistance in under make up and foundation. We have developed two new materials and make up products based on our theory. A new fluoroalkyl acrylate-methacrylates copolymer designed for incorporation in under make up is extremely sebum resistant and sweat proof. Another new acrylate polymer designed for inclusion in foundation absorbs sebum and changes to a solid. Usage tests confirm it is possible to reduce MFD by using under make up and foundation which incorporate our new materials to cover where skin furrows are few or shallow

  • PDF

An Experimental Study on the Durability Evaluation of Polymer Cement Restoration Materials for Deteriorated Reinforced Concrete Structures (성능저하된 철근콘크리트구조물 폴리머시멘트계 보수용 단면복구재의 내구성 평가에 관한 실험적 연구)

  • Kim, Moo-Han;Kim, Jae-Hwan;Cho, Bong-Suk;Park, Jong-Ho
    • Journal of the Korea institute for structural maintenance and inspection
    • /
    • v.10 no.1
    • /
    • pp.123-130
    • /
    • 2006
  • The duties of the restorative materials are to bear up against stress and to protect reinforcement corrosion. So the restorative materials are estimated by various kinds of strength, permeability and etc, But, in case of existing performance evaluation of restorative materials, because various deterioration factors are separately acted, the system of performance evaluation is different from that of combined deterioration of real structure and it is difficult to evaluate the exact performance of restorative materials. In this study, to evaluate Performance of restorative materials, we compare their korea standard properties in terms of compressive and bending strength and permeability of water and air with real durability for carbonation, salt damage and actual reinforcement corrosion like ratio of corrosion area. weight reduction and corrosion velocity of steel bar under environment of combined deterioration. The results showed that strength and permeability of restorative materials are similar but their resistance to carbonation, salt damage and actual reinforcement corrosion are very different.

Risk Factors of Deteriorated Voice Quality in Patients Who Underwent Thyroidectomy (갑상선 절제술 후 발생하는 주관적인 음성 기능 저하의 위험 요인에 대한 연구)

  • Lee, Hyoung Shin;Kim, Sung Won;Park, Chanwoo;Kim, Chang Hoi;Kim, Seobin;Lim, Sujin;Lee, Kang Dae
    • Korean Journal of Head & Neck Oncology
    • /
    • v.32 no.1
    • /
    • pp.7-11
    • /
    • 2016
  • Background and Objectives: Quality of voice may be deteriorated after thyroidectomy without any injury to recurrent laryngeal nerve. While there have been several studies showing the change of acoustic parameters after thyroidectomy, factors related to deteriorated voice quality have been rarely studies. In this study, we sought to analyze the factors associated to deteriorated voice quality after thyroidectomy. Materials and Methods: We made a retrospective review of 35 patients who underwent thyroidectomy for papillary thyroid carcinoma. Voice analysis including acoustic analysis, voice handicap index 10 (VHI-10), and GRBAS score was conducted before and 3 months after surgery. Patients were grouped according to the amount of increase in VHI-10 after surgery ; group A (${\Delta}VHI<7$) and group B (${\Delta}VHI{\geq}7$). Clinicopathologic factors associated to patients of group B were analyzed and changes of parameters from acoustic analysis in each group were evaluated. Results : Patients of group B were associated with age ${\geq}45$ years (p=0.025) and showed borderline association to total thyroidectomy (p=0.075) and tumor size ${\geq}1cm$ (p=0.086). Multivariate analysis demonstrated that those with age ${\geq}45$ years were independently associated to deteriorated quality of voice (p=0.014, HR=18.38). Patients of group B were also associated to significant deterioration of high pitch (p<0.001) and Grade score with borderline significance (p=0.054). Conclusion: Patients older than 45 years may have higher risk of deterioration of quality of voice after thyroidectomy based on increase of VHI-10 score (${\Delta}VHI{\geq}7$). Association with deterioration of high pitch should also be considered in these patients.

Development of the Deterioration Models for the Port Structures by the Multiple Regression Analysis and Markov Chain (다중 회귀분석 및 Markov Chain을 통한 항만시설물의 상태열화모델 개발)

  • Cha, Kyunghwa;Kim, Sung-Wook;Kim, Jung Hoon;Park, Mi-Yun;Kong, Jung Sik
    • Journal of the Computational Structural Engineering Institute of Korea
    • /
    • v.28 no.3
    • /
    • pp.229-239
    • /
    • 2015
  • In light of the significant increase in the quantities of goods transported and the development of the shipping industry, the frequency of usage of port structures has increased; yet, the government's budget for the shipping & port of SOC has been reduced. Port structures require systematically effective maintenance and management trends that address their growing frequency of usage. In order to construct a productive maintenance system, it is essential to develop deterioration models of port structures that consider various characteristics, such as location, type, use, constructed level, and state of maintenance. Processes for developing such deterioration models include examining factors that cause the structures to deteriorate, collecting data on deteriorating structures, and deciding methods of estimation. The techniques used for developing the deterioration models are multiple regression analysis and Markov chain theory. Multiple regression analysis can reflect changes over time and Markov chain theory can apply status changes based on a probabilistic method. Along with these processes, the deterioration models of open-type and gravity-type wharfs were suggested.

Calculation of Deterioration Depth of Major Rock Type Slopes caused by Freezing-Thawing in Korea (국내 주요 암종별 사면의 동결-융해에 의한 열화심도 계산)

  • Kwon, O-Il;Baek, Yong;Yim, Sung-Bin;Seo, Yong-Seok
    • The Journal of Engineering Geology
    • /
    • v.17 no.3
    • /
    • pp.359-365
    • /
    • 2007
  • Freezing and thawing cycle is one of the major weathering-induced factors in the mechanical weathering of the rock mass. This natural process accelerates rock weathering process by breaking down the parent rock materials and makes soil or weathered rock formation in a rock slope surface zone. It can also cause reduction of the shear strength in slopes. It is important to calculate the deterioration depth caused by freezing-thawing for a slope stability analysis. In this study, deterioration depths of rock slope due to freezing-thawing were calculated using the 1-D heat conductivity equation. The temperature distribution analysis was also carried out using collected temperature distribution data for last five years of several major cities in Korea. The analysis was performed based on the distributed rock types in study areas. Thermal conductivities, specific heats and densities of the calculation rocks are tested in the laboratory. They are thermal properties of rocks as input parameters for calculating deterioration depths. Finally, the paper is showing the calculated deterioration depths of each rock type slopes in several major cities of Korea.

Development for Penetrative Performance Improving Agent to In Prevent Deterioration of Concrete Structures (콘크리트 구조물의 내구성능 저하를 방지하는 침투형 성능개선제 개발)

  • Ryu Gum-Sung;Koh Kyoung-Taek;Kim Sung-Wook;Kim Do-Gyeum
    • Journal of the Korea Concrete Institute
    • /
    • v.17 no.4 s.88
    • /
    • pp.489-498
    • /
    • 2005
  • Recently, the deterioration of concrete structures have been increased by the damage from salt, carbonization, freezing & thawing and the others. Therefore, the measures for the deterioration of concretes have been taken. Among them, it has been often used that surface treatment which cut off the deterioration factors of durability by protecting the surface of concrete. The water proof and repair materials for concrete mainly use organic materials such as epoxy, these materials excel in intial bonding force and resistance to chemical agents. But they cause difference in the modulus of elasticity and the rate of shrinkage and expansion of concrete, and thus result in such problems as scaling and spatting in the progress of time. Therefore in this study it develop the performance Improving agent of concrete surface that can block a deterioration cause such as $CO_2$ gas, chloride ion and water from the outside and enhance waterproofing ability by reinforcing the concrete surface when applying it to concrete structures.

Safety factor calibration for bridge concrete girders

  • Silva, Rita C.;Cremona, Christian
    • Structural Engineering and Mechanics
    • /
    • v.49 no.2
    • /
    • pp.163-182
    • /
    • 2014
  • Safety factors proposed in codes CEB, B.A.E.L 91 and EUROCODE 1 cover a great number of uncertainties; making them inadequate for the assessment of existing structures. Suitable safety factors are established using a probabilistic assessment, once real dimensions, materials strength and existing structures deterioration mechanisms are taken into account. This paper presents a calibration method for safety factors using a typical set of RC bridges in France. It considers the principal stages of corrosion provoked by $CO_2$ and $Cl^-$ penetration and threshold indexes (${\beta}_0$) for existing structures. Reliability indexes are determined by the FORM method in the calibration method.

Predictors of Violent Behavior by Patient or Caregiver of Patient in the Emergency Department (응급실 환자 및 보호자의 폭력행위 예측요인)

  • Park, Eun Young;Lee, Eun-Nam
    • Korean Journal of Adult Nursing
    • /
    • v.26 no.5
    • /
    • pp.500-511
    • /
    • 2014
  • Purpose: The purpose of this study was to investigate predictors of violent behavior by patient or caregiver of patient in the emergency department. Methods: Subjects of the study were 447 residents who have visited the emergency department in community P Metropolitan City during the past year. The data collecting period was from June 1, 2012 to August 31, 2012. Data was collected using self-reported questionnaires. Results: Predictors of violent behavior in the emergency department were divided into personal and institutional factors. Personal factors included relationship with patients, presence of alcohol, reports of discontent during and past treatment and responses to deterioration in patient's conditions, institution factors included perceived attitudes toward medical workers' explanations and proficiency of medical workers, and delay in medical treatment hours. Conclusion: Knowledge of personal and institutional factors may permit emergency staff to minimize or prevent potential violence in the emergency department.

Characterization of Surface Deterioration for Stone Property around the Hyeonleung (Royal Tomb of Joseon Dynasty) in Guri, Korea (구리 현릉 능상석물의 표면 손상특성 평가)

  • Oh, Jeong Hyun;Kim, Sa Dug;Lee, Chan Hee;Lee, Tae Jong
    • Journal of Conservation Science
    • /
    • v.32 no.3
    • /
    • pp.353-364
    • /
    • 2016
  • The materials of sculptured stone property around the Hyeonleung Royal Tomb in Guri consist mainly of high weathered of granitic rocks with magnetite-series. Deterioration characteristics occurred highly with microorganism, soil inflow and black contaminants at the burial mound zone. As a result of deterioration evaluation, stone surface around the burial mound zone show serious comprehensive damage of soil inflow (50.5%) and lichen coverage (47.6%) which are the major damaging factors, and there are about 8.6% of biological growth noticeably in the north side. Surface contaminants and the discoloration had the complex causes. Gypsum occurred between joints of stones and the major contaminant type, darkening which was analyzed organic bodies caused discoloration. From result of ultrasonic velocity measurements, there are mean value of 2,195 m/s with highly weathered (HW) grade. Most of the stone properties showed 4 to 5 weathered grade. Therefore, it turned out that sculpture stone properties require conservation treatments. To remove soil accelerating damage factors and lichen occupying high percents, the cleaning process is necessary and consolidation, rejoining and filling are needed as well. Also, consideration on removing conservation materials containing Ca and e fflorescence is required and retreatments need to be considered.