• KSTLE International Journal
• /
• v.3 no.1
• /
• pp.49-53
• /
• 2002

Inconel 690 for nuclear steam generator tube has more chromium than the conventionally used Inconel 600 in order to increase the corrosion resistance. TD evaluate the tribological characteristics under fretting condition the fretting tests as well as sliding tests were carried out in elevated temperature water environment. Fretting tests of the cross-cylinder type were done under various vibrating amplitudes and applied normal loads in order to measure the friction forces and wear volumes. Also, the conventional sliding tests of pin-en-disk type were carried out to compare the test results. In fretting, the friction was very sensitive to the load and the amplitude. The friction coefficient decreased with increasing load and decreasing amplitude. Also, the wear of Inconel 690 can be predictable using the work rate model. Depending on normal loads and vibrating amplitudes, distinctively different wear mechanisms and of ten drastically different wear rates can occur. It was fecund that the fretting wear coefficients in water were increased as increasing the temperature of water.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2001.11a
• /
• pp.130-135
• /
• 2001

In this study, I have researched into the causes of defects in apartment house, The results of this study are listed below. (1) Water leakages which result from land sinking and cracks, results of misuse of back filling method, are the main reason of defects in civil engineering work and architectural work. (2) Inexperience and unwillingness are the main reason of defects in plaster work. (3) In windows work and painting work, the main reasons are lacks of precision construction and efflorescence resulting from outdoor air, respectively. (4) Defects in waterproofing work and electric work result from fault construction by low unit Costs. (5) Equipment work requires uses of standardized construction materials and management, and landscape architecture work requires minimizing human mistakes, for instance, degin carelessness. For the reasons stated above, the causes of defects in apartment house are insufficient construction labors, inferior construction materials, urgent construction process time, and conscientiousless industrialists who only seek after a profit margin.

• Journal of Integrative Natural Science
• /
• v.2 no.1
• /
• pp.28-31
• /
• 2009

We describe the synthesis and characterization of silicon nanoparticles prepared by the soluton reduction of SiCl4. These reactions produce Si nanoparticles with surfaces that are covalently terminated. The resultant organic derivatized Si nanoparticles as well as a probable distribution of Water-soluble Si nanoparticles are observed and characterized by photoluminescence(PL) spectroscopy. This work focuses originally on the organic- and water-soluble silicon nanoparticles in terms of the photoluminescence. Further this work displays probably the first layout of hydrogen terminated Si nanoparticles synthesized in solution at room temperature.

• Journal of the Korean Professional Engineers Association
• /
• v.35 no.4
• /
• pp.14-18
• /
• 2002

Water must be readily available to support all lives life and to create our earth. At first thought, It may seem that water is always available, since the earth is literally surrounded by water, so called water planet. The manner in which water circulates between earth and atmosphere determines where ample water supplies can be found and used for all organisms. If no forces except gravity were at work, the earth's water would settle in to the ocean basins and remain there.

• Journal of the Korean Chemical Society
• /
• v.53 no.4
• /
• pp.415-421
• /
• 2009

A convenient and practical synthesis of 1, 8-dioxo-octahydroxanthene derivatives using various aldehydes, 5, 5-dimethyl-1, 3-cyclohexanedione in water was successfully carried out in the presence of polyethylene glycol (PEG) as a catalyst. Simple work-up, clean products, high yields and water as a green solvent are the attractive features of this methodology.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.5 no.3
• /
• pp.58-65
• /
• 2002

This study synthesizes previous research accomplishments with analysis of problems and counterplan for the riparian forest zone management and ongoing research strategy is suggested. If a part of budgets for water use allotments is supported for forest watershed owner, this policy for the forest owner could encourage the forest management of watershed. Integrated riparian forest management guideline in city and county needs to be established for the implementation of government guidelines. Base on the guideline, working plans of city and county could be evaluated. Public Forest Tending Work for stream water quality and quantity conservation should be enlarged for forest watershed and forest area management in five big river watersheds. Forest watershed should be managed with a connected system for a pollutant reduction strategy in urban and industrial areas.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.5 no.2
• /
• pp.65-72
• /
• 2001

In order to improve the performance of a free power turbine type gas turbine engine by injecting the atomized water into a compressor inlet., a study on Moisture Air Turbine (MAT) cycle was proposed. Compressor work by air-water mixtures in phase change was theoretically considered, and it was found that the water evaporation might reduce the compressor work. Cycle model calculations predicted that power increments of 16.2%, 14.9% and 12.6% by 1.0% water to the air flow rate at the compressor intake with rotational shaft speeds of 1000, 1210, 1350 rps were obtained, and also thermal efficiency due to the reduction of compressor work was improved.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2001.04a
• /
• pp.54-58
• /
• 2001

In order to Improve the performance of a free power turbine type gas turbine engine by injecting the atomized water into a compressor inlet., a study on Moisture Air Turbine (MAT) cycle was proposed. Compressor work by air-water mixtures in phase change was theoretically considered, and it was found that the water evaporation might reduce the compressor work. Cycle model calculations predicted that power increments of 21.7%, 20.2% and 18.4% by 1.5% water to the air flow rate at the compressor intake with rotational shaft speeds of 1000, 1210, 1350 rps were obtained, and also thermal efficiency due to the reduction of compressor work was improved.

• Journal of Information Technology Applications and Management
• /
• v.25 no.3
• /
• pp.55-66
• /
• 2018

Early smart-work of company K was a technology-led way of applying ICT such as smart phones and mobile devices to business. After company K perceived the limitations of ICT-driven smart work, it propelled the work-smart, doing a work smart toward the way that human beings become central and a creative organizational culture is engendered. Company K propelled work-smart strategy in eight categories: simplification of data requirements, establishment efficient meeting culture, streamlining reporting and approval process, simplified document creation, overtime decrease, spreading flexible work system, settlement of healing leave, creating work-smart place. Company K set up an organizational culture secretariat dedicated to work-smart promotion and selected task priorities in consideration of urgency and effectiveness. Owing to such efforts, the company K's work-smart index rose sharply to 72 points this year from 56 points in the previous year. At the organizational culture survey, employees responded that organizational culture improved in all area. For a better future, company K analyzed its work-smart outcomes and planned progressively to improve its work-smart efforts based on employees opinions. This case study will serve as a guideline, for companies to make efforts to going forward to today work-smart beyond yesterday smart-work.

• Journal of the Korean Society of Safety
• /
• v.34 no.4
• /
• pp.103-110
• /
• 2019

Underwater works are indispensable in the coastal and ocean engineering fields, and the reliance on manpower is higher than land works. Divers who work for a long time in a high-pressure underwater environment are always exposed to the risks of diving-related diseases. To prevent them, proper planning, operation, and management of diving by a supervisor with professional diving knowledge are required. This study provides the basic data for supervisors to plan, operate, and manage air diving for safe and efficient work in underwater construction sites. It is well-known that air diving simulations using the varying permeability model (VPM) require a longer decompression time as the water depth and the residence time in water increase. Therefore, it is crucial to have a proper surface interval through repetitive diving rather than single diving to improve the safety of the divers and the efficiency of underwater work. Furthermore, coastal and ocean engineers who manage and supervise underwater construction work must acquire expert knowledge on diving before they can plan, operate, and manage diving.