• Journal of Pharmacopuncture
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• v.20 no.1
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• pp.36-44
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• 2017

Objectives: The goal of this study was to characterize Suvarna Bhasma Parada Marit by using the Ayurvedic test parameters, physico-chemical tests, and various instrumentation techniques. Methods: Suvarna Bhasma, an Ayurvedic formulation manufactured as per Bharat Bhaishajya Ratnakar 5/8357 (BBR), has been studied using various instrumentation techniques: X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDAX), laser particle size distribution (PSD) analysis, fourier transform infrared spectroscopy (FT-IR), and atomic absorption spectroscopy (AAS), and physico-chemical parameters, such as the loss on drying (LOD), loss on ignition (LOI), and acid insoluble Ash (AIA) were determined. In addition, Ayurvedic tests, such as Rekhapurnatva (enterable in the furrows of the fingers), Varitaratwa (floatable over water), Nirdhoomta (smokeless), Dantagre Kach-Kach (gritty particle feeling between the teeth), were performed. Results: The XRD study showed Suvarna Bhasma to be crystalline in nature and to contain more than 98% gold. The mean size of the gold crystallites was less than 10 microns, and the morphology was globular and irregular. Suvarna Bhasma contains gold as its single and major element, with EDAX and FT-IR spectra showing that it is more than 98% pure gold. The moisture content (LOD) is less than 0.5%, the LOI is less than 2%, and the AIA is not less than 95%. The Ayurvedic tests, as specified above, helped to confirm the quality of Suvarna bhasma prepared as per the text reference (BBR). Conclusion: This chemical characterization of Suvarna Bhasma performed in this study by using modern instrumentation techniques will be helpful in understanding its pharmacological actions and will help in establishing quality protocols and specifications to substantiate the safety, efficacy & quality of Suvarna Bhasma.

• Journal of the Korea institute for structural maintenance and inspection
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• v.18 no.4
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• pp.107-117
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• 2014

This study tests homogeneity and performs multiple comparison analysis among treatment levels of each factor group through t-test by materials and analysis of variance by structural type and service period. For that descriptive statistical analysis is performed for static and dynamic response characteristics and their ratios of calculated versus measured values based on a good many safety assessment reports for bridges. Homogeneity and post hoc test based on descriptive statistical analysis provide the measures for homogeneity identification among comparison groups in addition to the statistical reference values such as central tendency, variation and shape. This study is expected to be valuable for structural integrity assessment and design by comparing the measured and calculated values with the reference values for the homogeneous group identified, which can help the engineers review the adequacy of the values and put the group database to practical use.

• Journal of the Korean GEO-environmental Society
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• v.10 no.6
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• pp.49-60
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• 2009

In order to develop a new rockfall protection fence using high carbon steel wire rod (HSWR) material instead of the conventional wire rope material, the author has conducted the laboratory strength tests of both materials and their connections, and carried out evaluation of absorbing rockfall energy through the vertical field rockfall tests. The vertical filed rockfall tests showed that the new rockfall protection fence with 12 rows of the HSWR could absorb more rockfall energy than 50 kJ which stands for the typical design criteria. In addition, when the quantity of HSWR was increased up to the 16 rows, the capacity of absorbing energy was greatly improved. The new rockfall protection fence was successfully applied to the highway rock-cut slope. As a result of the filed application, its constructability was similar to the conventional fence, but its total image was improved as simple and clean. The total construction cost was saved up to 20% in comparison with the conventional one.

• Journal of the Korean Geosynthetics Society
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• v.9 no.3
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• pp.29-37
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• 2010

This study aims at evaluating the engineering properties of very poor graded fine sands deposited on the sea. Using materials sampled at SAEMANKEUM area, a series of rowe cell consolidation tests and triaxial compression tests are conducted in order to evaluate the characteristics of deformation and shear strength by the relative density. Prior to those tests, a maximum and a minimum relative densities are obtained. As a result, it appears that the minimum void ratio is 0.88, and the maximum compactible relative density is about 71%. In addition, internal frictional angle appears to increase linearly with an increase of the relative density which is similar to that of the port KUNJANG.

• Steel and Composite Structures
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• v.1 no.1
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• pp.17-32
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• 2001

The Rosette-joining system is a completely new press-joining method for cold-formed steel structures. One Rosette-joint has a shear capacity equal to that of approximately four screws or rivets. The Rosette thin-walled steel truss system presents a new fully integrated prefabricated alternative to light-weight roof truss structures. The trusses are built up on special industrial production lines from modified top hat sections used as top and bottom chords and channel sections used as webs which are joined together with the Rosette press-joining technique to form a completed structure easy to transport and install. A single web section is used when sufficient but can be strengthened by double-nesting two separate sections or by using two lateral profiles where greater compressive axial forces are met. An individual joint in the truss can be strengthened by introducing a hollow bolt into the joint hole. The bolt gives the connection capacity a boost of approximately 20%. A series of laboratory tests have been carried out in order to verify the Rosette truss system in practice. In addition to compression tests on individual sections of different lengths, tests have also been done on small structural assemblies and on actual full-scale trusses of a span of 10 metres. Design calculations have been performed on selected roof truss geometries based on the test results, FE-analysis and on the Eurocode 3 and U.S.(AISI) design codes.

• Journal of the Korean Society of Marine Environment & Safety
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• v.20 no.1
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• pp.78-85
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• 2014

LNG-RV has the additional equipments that enable to re-gastify liquefied LNG in LNG carrier. This vessel has Submerged Turret Loading(STL) system which transports gas through submarine terminal. When LNG-RV is operating at sea, the opening condition is formed by detaching STL equipment from a vessel. The primary objective of the current work is to estimate accurate speed loss for the opening condition of the LNG-RV employing numerical calculations and model tests. In the model tests, resistance and self-propulsion tests are carried out for the bare-hull and the opening condition without STL. In addition to these, flow visualization utilizing tuft is used to make the flow patterns visible, in order to get a qualitative or quantitative information for inner part in case of detaching the STL.

• Korean Journal of Materials Research
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• v.30 no.3
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• pp.123-130
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• 2020

In this study, two types of thick steel plates are prepared by controlling carbon equivalent and nickel content, and their microstructures are analyzed. Tensile tests, Vickers hardness tests, and Charpy impact tests are conducted to investigate the correlation between microstructure and mechanical properties of the steels. The H steel, which has high carbon equivalent and nickel content, has lower volume fraction of granular bainite (GB) and smaller GB packet size than those of L steel, which has low carbon equivalent and nickel content. However, the volume fraction of secondary phases is higher in the H steel than in the L steel. As a result, the strength of the L steel is higher than that of the H steel, while the Charpy absorbed energy at -40 ℃ is higher than that of the L steel. The heat affected zone (HAZ) simulated H-H specimen has higher volume fraction of acicular ferrite (AF) and lower volume fraction of GB than the HAZ simulated L-H specimen. In addition, the grain size of AF and the packet sizes of GB and BF are smaller in the H-H specimen than in the L-H specimen. For this reason, the Charpy absorbed energy at -20 ℃ is higher for the H-H specimen than for the L-H specimen.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.27 no.2
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• pp.109-118
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• 2016

Objectives: The aim of this study was to develop the computerized Comprehensive Learning Test-Reading (CLT-R) to evaluate the cognitive processes and achievements related to their basic reading ability and identify dyslexia in children and adolescents in South Korea. We also obtained the normative data and evaluated the reliability and validity of the test. Methods: We developed the CLT-R, including the word attack/nonword decoding, paragraph reading, sound blending, nonword repetition, rapid automatized naming, letter-sound matching, visual attention, orthography awareness, and digit span tests, for the purpose of diagnosing dyslexia. We investigated the reliability and validity of the tests and gathered the normative data from 399 subjects (male 48.9%), aged 5-14 years, from the last grade in kindergarten to middle school, dwelling in Seoul and Gyeonggi Province, South Korea. Results: No statistical differences were observed between the means of the tests and retests of the CAT. The mean of the correlation coefficient of the test-retest scores was 0.85. According to the construct validity test calculated by principal constant analysis using the oblique rotation method, 4 factors explained 70.0% of the cumulative variances. In addition, the normative data were obtained for all of the CLT-R subtests. Conclusion: The computerized CLT-R can be used as a reliable and valid tool to evaluate the reading achievement and reading related cognitive process in Korean children and adolescents in schools, clinics, and research institutes.

• Journal of the Korean Geotechnical Society
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• v.32 no.3
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• pp.15-27
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• 2016

In this study, a series of triaxial compressive strength tests were conducted for basaltic intact rocks sampled in the northeastern onshore and offshore, southeastern offshore and northwestern offshore of Jeju Island. Hoek-Brown constants $m_i$ were estimated from the results of the triaxial compression tests, and the properties of the Hoek-Brown constants $m_i$ were investigated. In addition, the cohesion and internal friction angle, strength parameters of Mohr-Coulomb failure criterion, obtained from the results of the triaxial compression tests were compared and analyzed with those estimated from Hoek-Brown failure criterion, respectively. As results, it was found that the Hoek-Brown constant $m_i$ is deeply related to the internal friction angle. As the internal friction grows, the Hoek-Brown constant $m_i$ increases exponentially. The cohesions estimated from the Hoek-Brown failure criterion, on average, are approximately 24% higher than those obtained from the Mohr-Coulomb failure criterion. The internal friction angles estimated from the Hoek-Brown failure criterion are similar to those obtained from the Mohr-Coulomb failure criterion.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.37 no.3
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• pp.307-313
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• 2009

In general, pyroshock is generated from the actuation of separation devices for several stage, fairing, and satellite separation in the flight of a launch vehicle. During these events, transient vibration phenomenon called pyroshock, which shows large acceleration in the high frequency range, occurs and it can result in the malfunction of electronic components which is equipped inside the launch vehicle or satellite. In this paper, mesh washer isolators made out of SMA were introduced for the isolation of pyroshock. One type of isolator primarily used pseudoelastic characteristics of SMA and the other type of isolator used shape memory effect of SMA. For the study of basic load-displacement relationship of each SMA isolator, compressive loading tests were performed and the results showed the capability of the isolator itself. Pyroshock isolation tests were followed and verified the outstanding isolation performance of isolator. In addition, random vibration tests were also performed and checked the dynamic characteristics of each SMA isolator.