545 research outputs found
Report of results of pleural biopsy (Needle biopsy and open biopsy) in 108 cases and 245 biopsies
No full text1. The results of 245 pleural biopsies perfomed in 108 patients including 219 pleural needle biopsies and 26 pleural open biopsies were reported. The method of pleural biopsy seems to be superior to any other currently available diagnostic procedures for the etiological diagnosis of pleurisy. 2. When the pleural needle biopsy is compared with the pleural open biopsy, the former method has definite advantages over the open biopsy. The pleural needle biopsy is simple, repeatable and has almost no complication. The method of pleural needle biopsy is the initial method of choice as Donohoe correctly stated and should be employed in every cases of the pleurisy to confirm the etiological diagnosis. The open biopsy should be reserved only for those cases in whom the needle biopsy had not proved satisfactory. 3. Utilizing the method of needle biopsy, the pathological diagnosis was made in 86 per cent of our cases at the initial biopsy. By repeated
needle biopsies, the results have improved to 91-92 per cent. 4. Most of the failures of the pleural needle biopsy were noted at the early stage of the study due to the unfamiliarity of the biopsy technique and later due to the incooperation of the patients. 5. The presence of the free pleural fluid serves as a convenient guide for the performance of the needle biopsy but successful needle biopsy was easily done without presence of pleural fluid when there is adequate pleural thickening. 6. 63-75 per cent of our diagnosed cases were proved to have granulomatous pleuritis, 13-31 per cent non-specific pleuritis and 5.4-5.8 per cent eosinophilic pleuritis due to paragonomiasis. The distribution of this pathological diagnosis seems to reflect quite well the actual picture of incidences of pleurisy of various different etiology in young adults in Korea. 7. The relationship of the success in obtaining adequate tissue by needle biopsy and interval between onset of symptom and biopsy was discussed. It was found that the interval has no significant effect on the production of adequate tissue by needle biopsy if the time elapsed is 4 weeks or more from the onset of symptom. 8. The significance of the pathological findings of ranulomatous pleuritis at one biopsy and non-specific pleuritis at another biopsy in the same patient was discussed. It is concluded that the single finding of nonspecific pleuritis at one needle biopsy cannot rule out the presence of granulomatous pleuritis and it is recommended that pleural biopsy be repeated whenever necessary. 9. The diagnostic significance of the chemical analysis of the pleural fluid was discussed in correlation with the results of the pleural needle biopsies. It is concluded that the number of examinations are not quite sufficient to draw any definite conclusion at the present stage of our study. 10. The finding of sanguinous pleural fluid in the patient of granulomatous pleuritis is quite high (72.7 %) and it was found that the sanguinous pleural fluid was most frequently found in the patients with granulomatous pleuritis in non-cancerous age. 11. Two groups of pleurisy patients with or without parenchymal lung lesion on chest X-ray were discussed in correlation with the results of the needle biopsy. It was found that the incidence of the pathological evidence of granulomatous inflammation on the biopsy specimens in these two groups is almost the same regardless of the presence of the demonstrable parenchymal lung lesion.
12. Histopathological finding of granulomatous pleuritis was discussed in conjunction with the significance of two types of tubercles, the soft tubercles and hard tubercles. In all specimens diagnosed as granulomatous pleuritis granulomas were demonstrated ranging from large, conglomerate tubercles with central caseation or giant cells to small granulomas without central caseation or Langhans' giant cells. 13. Histopathological significance of the finding of non-specific pleuritis on the biopsy specimens was discussed and the existence of a specific entity of "non-specific pleuritis" which is equivalent to the non-specific inflammation of the pericardium. 14. Cases of pleurisy due to paragonomiasis were discussed and the need of specific attention for search of new cases was emphasized.</p
Bayesian probabilistic damage detection of a reinforced-concrete bridge column
No full textA Bayesian probabilistic approach for damage detection has been proposed for the continuous monitoring of civil structures (Sohn H, Law KH. Bayesian probabilistic approach for structure damage detection. Earthquake Engineering and Structural Dynamics 1997; 26: 1259-1281). This paper describes the application of the Bayesian approach to predict the location of plastic hinge deformation using the experimental data obtained from the vibration tests of a reinforced-concrete bridge column. The column was statically pushed incrementally with lateral displacements until a plastic hinge is fully formed at the bottom portion of the column. Vibration tests were performed at different damage stages. The proposed damage detection method was able to locate the damaged region using a simplified analytical model and the modal parameters estimated from the vibration tests, although (1) only the first bending and first torsional modes were estimated from the experimental test data, (2) the locations where the accelerations were measured did not coincide with the degrees of freedom of the analytical model, and (3) there existed discrepancies between the undamaged test structure and the analytical model. The Bayesian framework was able to systematically update the damage probabilities when new test data became available. Better diagnosis was obtained by employing multiple data sets than just by using each test data set separately. Copyright (C) 2000 John Wiley & Sons, Ltd.The "rst author wishes to express his sincere thanks to Professor Gerard C. Pardoen and his students at the
University of California at Irvine for providing an opportunity to observe the bridge column test. Also, the
authors are indebted to Dr Charles R. Farrar and Dr Scott W. Doebling of the Los Alamos National
Laboratory for providing the vibration test data. This research was partially sponsored by the National
Science Foundation under Grant No. CMS-95261-2
Troca ou produção? Uma introdução crítica à proposta teórica de Alfred Sohn-Rethel
No full textThis paper explores and analyzes the critique of the modern-traditional epistemology of the philosopher Alfred Sohn-Rethel, focusing on the categories of "social synthesis" and "real abstraction" that the author postulated in his magnum opus Manual Work and Intellectual Work (2001) . Sohn-Rethel\u27s perspective seeks to critically adapt Marx\u27s materialist conception of history to the analysis of the emergence of the fundamental categories of scientific knowledge, as formulated in European modernity. However, the author\u27s emphasis on exchange over production ends up being inconsistent with basic postulates derived from the critique of political economy formulated by Marx in Capital. Thus, from the review of Marx\u27s categories and taking into account the position of other authors, the research emphasizes the limitations derived from the Sohn-Rethel proposal when analyzing the social forms of knowledge.El presente artículo explora y analiza la crítica a la epistemología moderna-tradicional del filósofo Alfred Sohn-Rethel centrándose en las categorías de “síntesis social” y “abstracción real” que el autor postuló en su obra magna Trabajo manual y trabajo intelectual (2001). La perspectiva de Sohn-Rethel busca adecuar críticamente la concepción materialista de la historia de Marx al análisis de la emergencia de las categorías fundamentales del conocimiento científico, tal y como se formularon en la modernidad europea. Sin embargo, el énfasis que el autor sostiene del intercambio por encima de la producción termina por ser incongruente con postulados básicos derivados de la crítica de la economía política formulada por Marx en El Capital. Así, a partir de la revisión de las categorías de Marx y tomando en cuenta la posición de otros autores, la investigación enfatiza en los limitantes derivados de la propuesta de Sohn-Rethel al analizar las formas sociales del conocimiento.Este artigo explora e analisa a crítica à epistemologia moderno-tradicional do filósofo Alfred Sohn-Rethel, com foco nas categorias de "síntese social" e "abstração real" que o autor postulou em sua magnum opus Trabalho Manual e Trabalho Intelectual (2001). ). A perspectiva de Sohn-Rethel procura adaptar criticamente a concepção materialista da história de Marx à análise da emergência das categorias fundamentais do conhecimento científico, tal como formuladas na modernidade europeia. No entanto, a ênfase do autor na troca sobre a produção acaba sendo inconsistente com os postulados básicos derivados da crítica da economia política formulada por Marx em O Capital. Assim, a partir da revisão das categorias de Marx e levando em conta a posição de outros autores, a pesquisa enfatiza as limitações derivadas da proposta de Sohn-Rethel ao analisar as formas sociais de conhecimento
Application of time reversal guided waves to field bridge testing for baseline free damage diagnosis
No full textThis research is partially supported by Pennsylvania Infrastructure Technology Alliance (PITA) Program and Pennsylvania Department of Transportation (PennDOT). The first author would like to acknowledge the graduate fellowship program from Samsung Lee Kun Hee Scholarship Foundation in Seoul, Korea. The authors would like to thank Paul Majoris and James Johnson for granting access to the Buffalo Creek Bridge site. The authors also would like to thank Profs. David W. Greve and Irving J. Oppenheim for providing invaluable comments and making the scaled girder specimen available for our study
Development of Dual PZT Transducers for Reference-Free Crack Detection in Thin Plate Structures
Get PDFA new Lamb-wave-based nondestructive testing (NDT) technique, which does not rely on previously stored baseline data, is developed for crack monitoring in plate structures. Commonly, the presence of damage is identified by comparing "current data" measured from a potentially damaged stage of a structure with "baseline data" previously obtained at the intact condition of the structure. In practice, structural defects typically take place long after collection of the baseline data, and the baseline data can be also affected by external loading, temperature variations, and changing boundary conditions. To eliminate the dependence on the baseline data comparison, the authors previously developed a reference-free NDT technique using 2 pairs of collocated lead zirconate titanate (PZT) transducers placed on both sides of a plate. This reference-free technique is further advanced in the present study by the necessity of attaching transducers only on a single surface of a structure for certain applications such as aircraft. To achieve this goal, a new design of PZT transducers called dual PZT transducers is proposed. Crack formation creates Lamb wave mode conversion due to a sudden thickness change of the structure. This crack appearance is instantly detected from the measured Lamb wave signals using the dual PZT transducers. This study also suggests a reference-free statistical approach that enables damage classification using only the currently measured data set. Numerical simulations and experiments were conducted using an aluminum plate with uniform thickness and fundamental Lamb waves modes to demonstrate the applicability of the proposed technique to reference-free crack detection.This research is supported by the Radiation Technology Program under
Korea Science and Engineering Foundation (KOSEF) and the Ministry
of Science and Technology (M20703000015-07N0300-01510) and
Korea Research Foundation Grant funded by the Korean Government
(MOEHRD, Basic Research Promotion Fund) (KRF-2007-331-D00462).
Any opinions, findings, and conclusions or recommendations expressed
in this material are those of the author(s) and do not necessarily reflect
the views of the funding agencies
Continuous fatigue crack monitoring without baseline data
No full textIn order to overcome the susceptibility of conventional non-destructive testing (NDT) techniques to operational and environmental variations, a new damage detection technique that does not require direct comparison with baseline data was previously developed by the authors for detecting a crack in a plate structure. This reference-free technique employs two pairs of collocated lead zirconate titanate transducers (PZTs) placed on both sides of the plate to generate and measure Lamb waves. Then, the existence of mode conversion due to the crack is identified from the Lamb wave signals instantly measured by PZTs. In this study, the effectiveness of the proposed technique is tested using a steel girder specimen. A cyclic loading is applied to the girder resulting in fatigue cracks, and the proposed technique detects the appearance of fatigue damage solely based on the measured Lamb waves at the present stage. Experimental results are presented to demonstrate the applicability of the proposed technique to fatigue crack monitoring, and issues related to PZT installation are discussed.This research is supported by the Radiation Technology
Program under Korea Science and Engineering Foundation
(KOSEF) and the Ministry of Science and Technology
(M20703000015-07N0300-01510) andKorea Research
Foundation Grant funded by the Korean Government
(MOEHRD, Basic Research Promotion Fund)
(KRF-2007-331-D00462). Any opinions, findings and
conclusions or recommendations expressed in this material
are those of the author(s) and do not necessarily reflect
the views of the funding agencies. The authors also
would like to thank Professors Kent A. Harris and Piervincenzo
Rizzo at University of Pittsburgh for designing
the steel girder specimen and conducting fatigue loading
tests
A study of vector electrocardiography.
No full textThe vector electrocardiographic method was applied on 126 healthy young Korean adults without any evidence of cardiac diseases. The range of the age of the subjects were between 19 and 34. The normal values of the magnitude
and direction of the mean QRS, T, P vectors, ventricular gradient and QRS-T angle in frontal plane were presented and discussed in comparison with those previously reported in the literature. Considering the age of the subjects under study, our results were in general agreement with those previously reported by other authors.</p
Energy-based Reference-Free Damage Diagnosis using A Single Pair of Collocated PZTs
No full textThis research is supported by the Radiation Technology Program (M20703000015-07N0300-01510) under Korea Science and Engineering Foundation (KOSEF) and U-Eco city project (C007L7510001-08L015800110) under Korea Institute of Construction & Transportation technology Evaluation and Planning (KICTEP). Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the funding agencies
A study of vector electrocardiography.
No full textThe vector electrocardiographic method was applied on 126 healthy young Korean adults without any evidence of cardiac diseases. The range of the age of the subjects were between 19 and 34. The normal values of the magnitude
and direction of the mean QRS, T, P vectors, ventricular gradient and QRS-T angle in frontal plane were presented and discussed in comparison with those previously reported in the literature. Considering the age of the subjects under study, our results were in general agreement with those previously reported by other authors.</p
Report of results of pleural biopsy (Needle biopsy and open biopsy) in 108 cases and 245 biopsies
No full text1. The results of 245 pleural biopsies perfomed in 108 patients including 219 pleural needle biopsies and 26 pleural open biopsies were reported. The method of pleural biopsy seems to be superior to any other currently available diagnostic procedures for the etiological diagnosis of pleurisy. 2. When the pleural needle biopsy is compared with the pleural open biopsy, the former method has definite advantages over the open biopsy. The pleural needle biopsy is simple, repeatable and has almost no complication. The method of pleural needle biopsy is the initial method of choice as Donohoe correctly stated and should be employed in every cases of the pleurisy to confirm the etiological diagnosis. The open biopsy should be reserved only for those cases in whom the needle biopsy had not proved satisfactory. 3. Utilizing the method of needle biopsy, the pathological diagnosis was made in 86 per cent of our cases at the initial biopsy. By repeated
needle biopsies, the results have improved to 91-92 per cent. 4. Most of the failures of the pleural needle biopsy were noted at the early stage of the study due to the unfamiliarity of the biopsy technique and later due to the incooperation of the patients. 5. The presence of the free pleural fluid serves as a convenient guide for the performance of the needle biopsy but successful needle biopsy was easily done without presence of pleural fluid when there is adequate pleural thickening. 6. 63-75 per cent of our diagnosed cases were proved to have granulomatous pleuritis, 13-31 per cent non-specific pleuritis and 5.4-5.8 per cent eosinophilic pleuritis due to paragonomiasis. The distribution of this pathological diagnosis seems to reflect quite well the actual picture of incidences of pleurisy of various different etiology in young adults in Korea. 7. The relationship of the success in obtaining adequate tissue by needle biopsy and interval between onset of symptom and biopsy was discussed. It was found that the interval has no significant effect on the production of adequate tissue by needle biopsy if the time elapsed is 4 weeks or more from the onset of symptom. 8. The significance of the pathological findings of ranulomatous pleuritis at one biopsy and non-specific pleuritis at another biopsy in the same patient was discussed. It is concluded that the single finding of nonspecific pleuritis at one needle biopsy cannot rule out the presence of granulomatous pleuritis and it is recommended that pleural biopsy be repeated whenever necessary. 9. The diagnostic significance of the chemical analysis of the pleural fluid was discussed in correlation with the results of the pleural needle biopsies. It is concluded that the number of examinations are not quite sufficient to draw any definite conclusion at the present stage of our study. 10. The finding of sanguinous pleural fluid in the patient of granulomatous pleuritis is quite high (72.7 %) and it was found that the sanguinous pleural fluid was most frequently found in the patients with granulomatous pleuritis in non-cancerous age. 11. Two groups of pleurisy patients with or without parenchymal lung lesion on chest X-ray were discussed in correlation with the results of the needle biopsy. It was found that the incidence of the pathological evidence of granulomatous inflammation on the biopsy specimens in these two groups is almost the same regardless of the presence of the demonstrable parenchymal lung lesion.
12. Histopathological finding of granulomatous pleuritis was discussed in conjunction with the significance of two types of tubercles, the soft tubercles and hard tubercles. In all specimens diagnosed as granulomatous pleuritis granulomas were demonstrated ranging from large, conglomerate tubercles with central caseation or giant cells to small granulomas without central caseation or Langhans' giant cells. 13. Histopathological significance of the finding of non-specific pleuritis on the biopsy specimens was discussed and the existence of a specific entity of "non-specific pleuritis" which is equivalent to the non-specific inflammation of the pericardium. 14. Cases of pleurisy due to paragonomiasis were discussed and the need of specific attention for search of new cases was emphasized.</p
- …
