• Title/Summary/Keyword: Sample disturbance

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The Effects of Sample Disturbance on Undrained Properties of Yangsan Clay (양산점토의 비배수 특성에 대한 시료교란의 효과)

  • 김길수;임형덕;이우진
    • Proceedings of the Korean Geotechical Society Conference
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    • 2000.03b
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    • pp.639-646
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    • 2000
  • It is important to estimate the mechanical properties of clay since it is directly related to the design and the construction of geotechnical structures. Site exploration, which is composed of boring, sampling, in-situ, or laboratory tests, is preformed to estimate the mechanical properties. However, mechanical properties of clay measured from laboratory test may be different from in-situ properties due to disturbances occurred during sampling, transportation, storage, and trimming. In this study, the degree of disturbance according to sampling method was estimated with the test results of CK/sub o/U triaxial compression test on Yangsan clay. The soil samples were obtained by three types of sampling method, j.e., 76mm-tube sampler, 76mm-piston sampler, and block sampler. In order to evaluate the quality of samples, volumetric strain, undrained shear strength, secant Young's modulus, and pore pressure coefficient at peak measured from each sample were compared with one another. From the test results, it was observed that mechanical properties of the block and piston samples were more reliable than those of tube samples. But it was observed that the water content of piston was similar to that of tube samples at given depths while the water content of block samples was 14.3∼15.8% smaller than that of piston and tube samples. In addition to the evaluation of the quality of samples, relationship between c/sub u// σ/sub vc/'and OCR was established from the results of the CK/sub o/U triaxial compression tests, which were carried out using SHANSEP method. And also undrained shear strength was analyzed using the in-situ test data such as Cone Penetration Test(CPT), Dilatometer Test(DMT), and Field Vane Test(FVT) and was compared with that evaluated from CK/sub o/U triaxial compression test.

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Development of a Sampler that Minimizes Sample Disturbance and Review of its Applicability (인발시 시료이탈을 최소화한 불교란시료 채취 샘플러 개발 및 적용성 검토)

  • Kim, Jongkwan;Han, Jin-Tae;Park, Ka-hyun;Shin, Hyu-Soung;Zhuang, Li;Yeom, Sun;Kim, Ki-Seog
    • Journal of the Korean Geotechnical Society
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    • v.39 no.3
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    • pp.17-27
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    • 2023
  • In order to accurately determine soil characteristics, it is necessary to collect undisturbed samples, and it is important to collect these samples with minimal disturbance. In this study, a sampler that minimizes sample disturbance was developed by attaching a catcher to the tip, and its applicability was reviewed through in situ sampling, X-ray CT, and laboratory tests. Results confirmed that horizontal cracks are likely to occur when using the Shelby tube sampler, whereas these cracks can be suppressed when using the newly developed sampler. Moreover, consolidation and shear test results showed that the samples collected using the newly developed sampler showed higher maximum shear strength compared to those collected using the Shelby tube sampler.

The Effects of the Hominis Placenta Herbal acupuncture on Sleep pattern disturbance (자하거(紫河車) 약침(藥鐵)이 수면장애(睡眠障碍)에 미치는 효과(效果))

  • Lee, Chae-Wooi;Kim, Hong-K;Youn, Hyoun-Min
    • Journal of Pharmacopuncture
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    • v.8 no.1
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    • pp.5-11
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    • 2005
  • Objectives : This study has been designed and performed to identify the effect of Hominis Placenta herbal acupuncture which is usually used in reducing sleep pattern disturbances. Methods : The study subjects studied included 48 patients who were admitted in hospital located in Pusan, and they were classified into 2 groups : 25 patients in the experimental group who injected Hominis Placenta herbal acupuncture and 23 patients in the control group who were treated by acupuncture. The both group injected on $GB_{20}$, $GB_{12}$ and $GB_{20}$ for 5 days without medicine. The sleep pattern disturbance score was measured by using 15 questions according to Korean Sleep Scale A(Oh, Jin Joo. Song, Mi. Soon. Kim, Shin Mi. 1998). Results & conclusions : The sleep pattern disturbance score of the experimental group who injected Hominis Placenta herbal acupuncture was significantly lower than that of the control group(t=7.00 p=.00). These results provided that Hominis Placenta herbal acupuncture of $GB_{20}$, $GB_{12}$ and HT, was effective for relieving sleep pattern disturbances, it is need mere sample's number and more treatment's duration.

A Study on Women's Fatigue and Sleeping Disturbance (성인여성의 피로와 수면장애에 관한 연구)

  • Lee, Sun-Ok;Ahn, Sook-Hee;Kim, Mi-Ok
    • Women's Health Nursing
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    • v.11 no.2
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    • pp.163-168
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    • 2005
  • Purpose: This study was to identify the relationship between fatigue and sleep disturbance in adult women so as to provide basic data for developing a women's health promotion program and nursing intervention. Method: A convenience sample of 184 women who visited a Well-baby clinic at P city Maternal child center during October in 2004 was obtained. Data was collected by self-administered questionnaires. Results: The Subjects' mean age was 36.87 years and 70% were employed and had more education than high school. The mean level of fatigue was 56.65, mean sleeping hours were 6.54, and time until falling asleep was 17.58 minutes. Scores of fatigue differed by subject's age, level of education, and menstruation status. In addition, sleeping hours differed by age, occupation status, and income level. There were significant low levels of correlation between fatigue and sleeping hours (r=-.16) and getting up too early (r=-.15). Conclusion: This study concludes that fatigue and sleeping patterns have a significant relationship.

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Prediction Model of Fatigue in Women with Rheumatoid Arthritis (여성 류마티스 관절염 환자의 피로 예측 모형)

  • Lee, Kyung-Sook;Lee, Eun-Ok
    • Journal of muscle and joint health
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    • v.8 no.1
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    • pp.27-50
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    • 2001
  • Rheumatoid arthritis is a chronic systemic autoimmune disease. Although the joints are the major loci of the disease activity, fatigue is a common extraarticular symptom that exists in all gradations of rheumatoid arthritis. Fatigue is defined as a subjective sense of generalized tiredness or exhaustion and has multiple dimensions. Therefore fatigue is a common and frequent problem for those with rheumatoid arthritis. In fact, 88-100% of individuals with rheumatoid arthritis experience fatigue. Especially the degree of fatigue is higher in women than men with rheumatoid arthritis. Despite the importance of fatigue among the patients with rheumatoid arthritis, the mechanism that leads to fatigue in rheumatoid arthritis is not completely understood. This study was intended to test and validate a model to predict fatigue in women with rheumatoid arthritis. Especially it was intended to identify the direct and indirect effects of the variables of pain, disability, depression, sleep disturbance, morning stiffness, and symptom duration to fatigue. Data were collected by questionnaires including Multidimensional Assesment of Fatigue(Tack, 1991), numeric scale of pain, graphic scale of joints, Ritchie Articular Index, Korean Health Assessment Questionnaire(Bae, et al., 1998), Inventory of Function Status(Tulman, et al., 1991), Center for Epidemiologic Studies-Depression, and Korean Sleep Scale(Oh, et al 1998). The sample consisted of 345 women with a mean duration of rheumatoid arthritis for 10.06 years and a mean age of 49.64 years. SPSS win and Win LISREL were used for the data analysis. Structural equation modeling revealed the overall fit of the model. Pain predicted fatigue directly and indirectly through disability, depression, and sleep disturbance. Disability, sleep disturbance predicted fatigue only directly, while depression only indirectly through disability and sleep disturbance. Also morning stiffness and symptom duration predicted fatigue through disability and depression. All predictors accounted for 65% of the variance of fatigue. Depression, pain, and disability predicted sleep disturbance. Depression had reciprocal relationship with disability and they both were predicted by pain directly and indirectly. In summary, pain, depression, disability, sleep disturbance, morning stiffness, and symptom duration contributed to the fatigue of patients with rheumatoid arthritis. The best predictor of fatigue was pain. This finding indicates that the modification of pain, depression, disability, sleep disturbance, morning stiffness could be nursing intervention for relief or prevention of fatigue.

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Case Study Of Reducing Specimen Disturbance Using Vertical Fixing Sample Frame (VFSF) (연직고정장치(VFSF)를 활용한 불교란시료의 교란효과 저감사례)

  • Lim, Beyong-Seok;Seo, Deok-Dong
    • Journal of the Korean GEO-environmental Society
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    • v.7 no.2
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    • pp.55-66
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    • 2006
  • The existing Highway LA-1 of US is required to be replaced for covering increasing regional demands of transportation such as Hurricane evacuation and oil industry. This 28 km crosses wetlands and is a sensitive environmental area. Huge amount of soil investigation and laboratory tests were performed with best efforts to overcome inherit errors of sampling, disturbance, and testing procedures for this project. The data scattering was corrected through using central tendency theory.

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Pattern of Species Distribution along Environmental Variables in Two Different Forest Beat of Raghunandan Reserve Forest of Habiganj

  • Hosen, Md. Shahadat;Ahamed, Md. Saleh
    • Journal of Forest and Environmental Science
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    • v.33 no.4
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    • pp.257-269
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    • 2017
  • The study has piloted to find the Pattern of species distribution along environmental variables and disturbance in Raghunandan Reserve Forest. Shaltila and Shahapur beat of Raghunandan Hill Reserve Forest are situated in Chunarughat sub-district of Habiganj district between $24^{\circ}5^{\prime}-24^{\circ}10^{\prime}N$ and $91^{\circ}25^{\prime}-91^{\circ}30^{\prime}E$ under the Sylhet Forest Division. The Environmental variable and vegetation data were collected from 30 sample plots from each forest beat by using arbitrary sampling without preconceived bias. 51 species were found from Shaltila and 34 species found in Shahapur forest beat. Thus the dataset continued with total 85 species in 60 samples. To determine the relationships between tree species distribution and environmental variables, Canonical Correspondence Analysis (CCA) ordination method were performed separately for two forest beat. In CCA ordination, tree species showed significant variation along environmental gradients in terms of soil organic matter and disturbances (p<0.05) in the case of Shaltila forest. Potassium has a significant relationship with axis 1 and axis 2 in this forest. But Shahapur forest showed no significant relationship between species and environmental variables. Phosphorus has a significantly negative relationship with axis 2 in this forest. Disturbance played as a critical role of this forest thus influencing the distribution of species. The study showed that the distributions of tree species are strongly influenced by disturbance and organic matter in Shaltila and Shahapur forest beat showed no significant relationship between species and environmental variables. Future research should be included more environmental variables with larger study area that identify the most important environmental forces which will drive by species distribution findings in this forest.

Effectiveness of low-level laser therapy on recovery from neurosensory disturbance after sagittal split ramus osteotomy: a systematic review and meta-analysis

  • Firoozi, Parsa;Keyhan, Seied Omid;Kim, Seong-Gon;Fallahi, Hamid Reza
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.42
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    • pp.41.1-41.11
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    • 2020
  • Background: Orthognathic surgery such as bilateral sagittal split ramus osteotomy (BSSRO) for the treatment of mandibular deformities is one of the most common procedures in maxillofacial operations that may lead to neurosensory disturbance. In this study, we aimed to evaluate the effectiveness of low-level laser therapy (LLLT) on augmenting recovery of neurosensory disturbance of inferior alveolar nerve (IAN) in patients who underwent BSSRO surgery. Methods: A comprehensive literature search was conducted by two independent authors in PubMed, Cochrane Central Register of Controlled Trials (CENTRAL), Scopus, Embase, and Google Scholar electronic databases. Besides, a manual search of all textbooks and relevant articles were conducted. Searches took place in August 2020 and were limited to published and peer-reviewed articles from 2000 to 2020. All analysis was performed using the comprehensive meta-analysis (CMA) and the STATA MP (version:16) software. The weighted mean difference (WMD) using the inverse variance method and the standard mean difference (SMD) was considered for continuous variables. Results: Seventy-four papers were retrieved after removing duplicate studies and finally, eight studies were assessed for qualitative synthesis and five for meta-analysis. Totally, 94 patients were included in the meta-analysis. Based on the meta-analysis, it was shown that LLLT was not effective in a short interval (0 to 48 h) after surgery, but in a period of more than 1 month after surgery, the positive results of treatment can be observed strikingly. Also, LLLT side/group showed no significant difference in some aspects of neurosensory recovery such as thermal sensation compared to the placebo side/group. Conclusions: The meta-analysis of randomized controlled trials revealed that LLLT generally improves IAN sensory disturbance caused by BSSRO. Further high-quality clinical trials with longer follow-up periods and larger sample sizes are recommended.

Microstructure, mineralogy and physical properties: techniques and application to the Pusan Clay

  • Locat, Jacques;Tanaka, Hiroyuki
    • Proceedings of the Korean Geotechical Society Conference
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    • 1999.11b
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    • pp.15-31
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    • 1999
  • The Pusan Clay is analyzed hereafter from a point of view of mineralogy and microstructure. Results indicate that the Pusan Clay is basically illitic in nature and that the soil microstructure reveals some characteristics which could be responsible for its brittle behavior as observed from sample disturbance. The overall analysis would tend to consider that the Pusan Clay profile analyzed here shows mechanical properties similar to well structured soils or so-called cemented soils.

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Compressibility Characteristics Associated with Depositional Environment of Pusan Clay in the Nakdong River Estuary (낙동강 하구지역 부산점토의 퇴적환경에 따른 압축특성)

  • Chung, Sung-Gyo;Ninjgarav, E.;Ryu, Chun-Kil;Jang, Woo-Young
    • Journal of the Korean Geotechnical Society
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    • v.22 no.12
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    • pp.57-65
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    • 2006
  • In the Nakdong River estuary soft and thick clay, which called Pusan clay, are deposited. Despite a number of great reclaimed projects that have been performed in the area, the consolidation settlement and time have been significantly underestimated due dominantly to sample disturbance, since the last decade. In order to resolve the underestmation, it was necessary to examine the compressibility characteristics through a systematic geotechnical investigation on the clay. In this study an advanced sampling technique was adopted on two sites chosen along the coastline, and then oedometer testing and geological investigation were performed for the undisturbed and reconstituted samples. As the results, the compressibility parameters of the clay were representatively determined, as well as their correlation. Particularly the effects of depositional environment on the physical indexes, level of structure, sample disturbance and compressibility parameters were analyzed for the clay.