• Advances in concrete construction
• /
• v.14 no.2
• /
• pp.103-113
• /
• 2022

On the basis of fabrication, the utilization of nano material in numerous industrial and technological system, obtained the utmost significance in current decade. Therefore, the current investigation presents a theoretical disposition regarding the flow of electric conducting Williamson nanoliquid over a stretchable surface in the presence of the motile microorganism. The impact of thermal radiation and magnetic parameter are incorporated in the energy equation. The concentration field is modified by adding the influence of chemical reaction. Moreover, the splendid features of nanofluid are displayed by utilizing the thermophoresis and Brownian motion aspects. Compatible similarity transformation is imposed on the equations governing the problem to derive the dimensionless ordinary differential equations. The Homotopy analysis method has been implemented to find the analytic solution of the obtained differential equations. The implications of specific parameters on profiles of velocity, temperature, concentration and motile microorganism density are investigated graphically. Moreover, coefficient of skin friction, Nusselt number, Sherwood number and density of motile number are clarified in tabular forms. It is revealed that thermal radiation, thermophoresis and Brownian motion parameters are very effective for improvement of heat transfer. The reported investigation can be used in improving the heat transfer appliances and systems of solar energy.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.18 no.1
• /
• pp.39-46
• /
• 1982

The author has developed the computer program in order to calculate the optimum alignment condition of marine propulsion shafting by linear programming method. The input of program was calculated by the matrix method of three-moment. He compared the calculated values with the experimental values measured by the strain gage on the model shaft, and the values of calculation on actual propulsion shafting with those of Det norske Veritas. The computer program of optimum alignment has been applied to the actual shaft. The results obtained are as follows: 1. To obtain the reaction of supporting points in the straight line necessary to the optimum alignment and the reaction influence number, after the computer program had been developed and then adapted, the result of experimental values and calculated values agreed with each other and the values of the actual shaft were also approximately similar to the values of other program. 2. In this paper, the measuring method on model shaft by strain gage can be effectively used at the time of adjusting alignment condition of actual shaft. 3. The supporting bearing should be considerably readjusted to the vertical direction in order to satisfy some limited condition.

• Elastomers and Composites
• /
• v.36 no.4
• /
• pp.268-277
• /
• 2001

The MDI(4,4'-diphenyl methane diisocyanate) was mixed with PPG, PEG and trimethylolpropane(TMP) respectively to prepare polyurethane resin. The various physical properties were measured for the mixtures. The gel-time was shortened by adding of PEG and TMP The molecular weight made a greater influence on the gel-time than the number of functional groups. The NCO-OH reaction was more active and faster than the NCO-NCO reaction. The hardness was influenced by crosslinking-density and molecular structure. The NCO-OH reactions yielded the flexible films and the NCO-NCO reactions yielded the brittle films. The increase of crystallinity and shrinkage induced the low adhesion ratio but the adding of TMP induced the high adhesion ratio. The flame-retardancy was influenced by quantity and kinds of flame-retardant. IXOL B-251 was the most excellent among the flame-retardants employed in this study. TCCP was partially separated because of the lack of solubility.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.3 no.3
• /
• pp.31-39
• /
• 1999

In this paper, numerical experiment is attempted to analyze and compare the combustion efficiency of the burning sprays due to OFO, FOF triplet / FOOF split doublet injectors. Preconditioned Wavier-Stokes equation system with low Reynolds number $\kappa$-$\varepsilon$ model for turbulence closure, is LU-SGS time-integrated. Spray processes are modeled by DSF analysis with experimentally determined injection characteristics. n-heptane/air global reaction model approximates the combustion for simplicity, and the influence of turbulence on the chemical reaction is included using eddy dissipation model. The results showed the FOF triplet injector of highest combustion efficiency, whereas the OFO type of poet performance. It was also observed that the droplet mean diameter and the average gas temperature due to the mixing efficiency, are the representative parameters for the performance design of combustion.

• Journal of the Korean Society of Safety
• /
• v.28 no.4
• /
• pp.38-42
• /
• 2013

This study performed the quantitative distribution analysis of created voids to an insulator when applying general flame and DC short-circuit current to 2.5 $mm^2$ HIV (600 V Grade Heat-Resistant Polyvinyl Chloride Insulated Wires). The diameter of cross-section of HIV normal product and the radius of conductor were measured to be 3.3 mm and 1.8 mm. The exterior of HIV exposed to general flame showed severe carbonization and its interior exhibited voids created by dechlorination reaction. This study observed the characteristics that, when the shortcircuit current applied for 2 seconds from a DC 12 V lead battery, the conductor and neighboring insulator were melted, causing the insulator adhering to the conductor. On average, 87 voids were created on 10 mm of the HIV. The average diameter of voids was 0.25 mm. In addition, it was found that, when the short-circuit current applied for 4 seconds, the interior of insulator in contact with conductor severely carbonized and showed exfoliation phenomenon. On average, 47 voids were created, with more voids at the bottom. The average diameter of voids was 0.20 mm. When the short-circuit current for 6 seconds, most parts of upper part of conductor was carbonized, 20 voids were created. The average diameter of voids was measured to be 0.24 mm. It could be seen that the created voids received little influence by the type of energy source and the number of created voids was reduced as the energy supply time increased.

• Korean Journal of Clinical Pharmacy
• /
• v.21 no.4
• /
• pp.353-363
• /
• 2011

The World Health Organization (WHO) declared the outbreak of H1N1 pandemic in 2009. South Korea also had outbreaks of H1N1 virus and used oseltamivir in large volume with increased reports of adverse drug reaction(ADR). The present study was aimed to investigate the ADR frequency, the factors related to ADR, and characteristics of oseltamivir's ADR. Participants for the study were patients randomly drawn from those who were prescribed oseltamivir for treatment from CHA Bundang Medical Center during October 1 and October 30. The information examined as factors related to ADR were collected by a subsequent cross-sectional telephone survey. The factors are the following; a) age; b) gender; c) patient medical history; d) diagnosis of H1N1 virus; e) adherence; f) whether taking other medication with oseltamivir or not; and g) the number of combined medications. We also asked ADR after taking oseltamivir. Total subjects were 86 patients. The average age is $22.6{\pm}18.48$ years old. The gender was 45.3% women and 54.7% men. Half (50%) of all respondents showed one or more ADR, 67.4% were positively diagnosed for H1N1 virus, and 54.7% were completed the full course of oseltamivir (i.e. twice daily x 5days). The most frequently reported ADR symptoms were: dizziness (15.1%), nausea (11.6%), lethargy (10.4%), diarrhea (10.4%), abdominal pain (8.1%), headache and vomiting (6.9%). ADR classifications by categories are gastro intestinal (44.2%), neuropsychiatric events (22.1%), systemic symptom (20.9%), skin events (5.8%), eye events (4.7%), and other cases (2.3%). The onset of ADR 'after taking 1~3 doses' was 69.7%. No increase in neuropsychiatric events was detected in children and adolescents. No factors examined for the study do have significant influence on the presence of ADR. This study showed that ADR of oseltamivir have occurred in half of the patients. The use of oseltamivir is essential for treatment and prophylaxis of influenza A(H1N1). But mass treatment should be properly monitored for ADR.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.20 no.6
• /
• pp.1048-1061
• /
• 1996

The most important practical feature that represents the performance of a washing machine is its ability to remove stains or soils from clothes. There are various tests to measure a washing machine's ability to remove stains or soils from clothes. The results of these tests are dependent upon the kind of soiled fabrics used. Moreover, these results may reflect some aspects of the effectiveness of a washing machine in cleaning clothes due to the paritcular compositions of chemicals which comprise soils in soiled fabrics and the particular conditions in which the results are evaluated. After selecting factors presumed to have a major effect on the cleaning ability of a washing machine and choosing most widely used soiled fabrics, we use experimetal statistics methods to screen real factors from them that influence the cleaning ability of a washing machine in a statistically significant manner for each soiled fabric. Using the least number of experimental rules required to extract the necessary information, we then proceed to present the study on the relations between the sets of selected factors and the soiled fabrics. We would then suggest which soiled fabrics is the best for evaluating the performance in cleaning clothes of a washing machine based on the above study.

• Journal of Welding and Joining
• /
• v.11 no.2
• /
• pp.42-52
• /
• 1993

The corrosion fatigue fracture behaviour of dual phase steel was investigated in 3% NaCl solution at 302MPa and 137MPa. Fatigue test was conducted by cantilever type of self-made rotary bending fatigue testing machine. The fatigue strength increased with increasing the hardness of 2nd phase. Corrosion pit originated at the boundary of the 2nd phase. The size and number of corrosion pits were influenced by the 2nd phase hardness, and pits remained constant in size just after they were transited into cracks. The life of crack initiation was effected by stress level. The shape of relation of .DELTA. K and da/dN has smaller scattering in it in 3% NaCl solution than that in air. The higher the 2nd phase hardness is, the greater the corrosion fatigue life becomes. Corrosion fatigue fracture behaviour was primarily effected by mechanical factor in case of high stress(302MPa), but by electro-chemical reaction in a lower stress(137MPa). As stress level got lower and hardness of the 2nd phase got higher, the roughness of fracture surface increased.

• Advances in environmental research
• /
• v.2 no.1
• /
• pp.35-49
• /
• 2013

Research work on removal of fluoride from water, referred to as water defluoridation, has resulted into the development of a number of technologies over the years but they suffer from either cost or efficiency drawbacks. In this work, enhancement effects of phosphate and silicate on defluoridation of water by low-cost Plaster of Paris (calcined gypsum) were studied. To our knowledge, the influence of silicate on defluoridation was not reported. It was claimed, that the presence of some ions in the treated water samples, was decreasing the fluoride removal since these ions compete the fluoride ions on occupying the available adsorption sites, however, phosphate and silicate ions, from its sodium slats, have enhanced the fluoride % removal, hence, precipitation of calcium-fluoro compounds of these ions can be suggested. Percentage removal of $F^-$ by neat Plaster is 48%, the electrical conductance (EC) curve shows the typical curve of Plaster setting which begins at 20 min and finished at 30 min. The addition of phosphate and silicate ions enhances the removal of fluoride to high extent > 90%. Thermodynamics parameters showed spontaneous fluoride removal by neat Plaster and Plaster-silicate system. The percentage removal with time showed second-order reaction kinetics.

• The Journal of Asian Finance, Economics and Business
• /
• v.8 no.2
• /
• pp.993-1003
• /
• 2021

The contribution made by the tourism sector is strategic enough to provide job opportunities and increase the state's foreign exchange which will be followed by development in the information and technology sectors. The population of this study includes all domestic tourists who visit the Batu City Angkut Museum over 17 years of age and who have obtained information via eWOM from other tourists. Based on the measurement, a minimum of 160 respondents must be selected as the research sample. Non-probability sampling techniques are used to select samples. Social media had been used by companies to provide information, services, and products related to tourism, and it was utilized by tourists to share information about their traveling experiences. Nowadays, tourists have become more selective and critical in selecting their destinations as they have become good observant in finding adequate information about certain destinations before deciding to visit the place. This reaction can be influenced by positive eWOM communication, positive image, and trust given to certain tourist destinations. Therefore, improving the number of visits requires the management of certain tourism service companies to apply proper marketing strategy and provide various advantages and best service quality to attract more visitors and give satisfaction to visitors.