• Applied Chemistry for Engineering
• /
• v.24 no.1
• /
• pp.10-17
• /
• 2013

Heavy oil residue upgrading process was being used in conventional refinery process. Recently, as the importance of non conventional energy development is growing up, the commercial projects of heavy oil upgrading are getting more active than before. For having competitive business model in the resource competition, non conventional energy development should be considered as an important business strategy. In developing oil sands, extra heavy oil, and shale gas, canadian oil sands and extra heavy oil have great importance in substitution of conventional oil consumption. In oil sands development, the bitumen, which is extracted from oil sands, has great value after upgrading or refining process. Similar process is being used current conventional refinery process. The bitumen is highly viscous hydrocarbon. This bitumen includes impurities which can not be treated in conventional refinery process. As this reason, specified process is needed in bitumen or extra heavy oil upgrading process. Moreover, there will be additional specified facilities in the process of production, transportation and marketing. In oil sands, there are various kinds of commercial upgrading process. Extraction, dilution, coking and cracking method were being used commercially.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.25 no.6
• /
• pp.231-238
• /
• 2015

Sapphire single crystals have been highlighted for epitaxial of gallium nitride films in high-power laser and light emitting diode industries. Among the many crystal growth methods, vertical Bridgman process is an excellent commercial method for growing high quality sapphire crystals with c-axis. In this study, the thermally induced stress in Sapphire during the vertical Bridgman crystal growth process was investigated using a finite element model. A vertical Bridgman process of 2-inch Sapphire was considered for the model. The effects of vertical and transverse temperature gradients on the thermal stress during the process were discussed based on the finite element analysis results.

• Journal of Korean Society of Water and Wastewater
• /
• v.28 no.2
• /
• pp.195-206
• /
• 2014

Immobilization of anaerobic ammonium oxidizing bacteria has been studied to enhance the biomass retention of the slowly growing bacteria and the process stability. The purpose of this study was to compare the nitrogen removal efficiency of granular and immobilized anammox bacteria with poly vinyl alcohol and alginate. The specific anammox activity of the granular, homoginized and immobilized anammox bacteria were $0.016{\pm}0.0002gN/gVSS/d$, $0.011{\pm}0.001gN/gVSS/d$ and $0.007{\pm}0.0005gN/gVSS/d$, respectively. Although the activity decreased to 43.7 % of the original one due to low pH and $O_2$ exposure during the homogination and the immobilization, it was rapidly recovered within 7 days in the following continuous culture. When synthetic T-N concentrations of 100, 200, 400, 800 mg/L were fed, the immobilized anammox bacteria showed higher nitrogen removal efficiencies at all operational conditions than those of granular anammox bacteria. When the sludge retention time was shorten below 30.7 days and the reject water was fed, the nitrite removal efficiency of the granular anammox bacteria dropped to 8 % of the initial value, while that of the immobilized anammox bacteria was maintained over 95 % of the initial one. The immobilization with poly vinyl alcohol and alginate would be a feasible method to improve the performance and stability of the anammox process.

• Journal of the Korean Institute of Gas
• /
• v.22 no.4
• /
• pp.55-62
• /
• 2018

There is growing interest in solar power generation due to global warming. As a result, demand for polysilicon, which is the core material for solar cells, is increasing day by day. As the market grows, large and small accidents occurred in the production process. In 2013, hydrochloric acid leaked from the polysilicon manufacturing plant in SangJu. In 2014, a fire occurred at a polysilicon manufacturing plant in Yeosu, and in 2015, STC(Silicon Tetrachloride) leaked at a polysilicon manufacturing plant in Gunsan City. Leakage of chemicals in the polysilicon manufacturing process can affect not only the workplace but also the surrounding area. Therefore, in this study, we identified the hazardous materials used in the polysilicon manufacturing process and quantitatively estimate the amount of leakage and extent of damage when the worst case scenario is applied. As a result, the damage distance by explosion was estimated to be 726 m, and the damage distance to toxicity was estimated to be 4,500 m. And, if TCS(Trichlorosilane), STC(Silicon Tetrachloride), DCS(Dichlorosilane) leaks into the air and reacts with water to generate HCl, the damage distance is predicted to 5.7 km.

• Journal of KIISE
• /
• v.41 no.9
• /
• pp.625-632
• /
• 2014

With the trend of increasing needs for high-technology from customer and tightening regulation on automotive fuel efficiency and safety, application of E/E system has been expanding consistently in automotive industry. Thus, demand for core elements of E/E system has been growing: micro controller, analog IC and ASIC. But, development process of automotive semiconductor hasn't been clearly established in domestic area. This research aims to present a guide and an example for construction of requirement and design development process on semiconductor based on ISO/TS 16949 that is requirement for quality management system, CMMI that has been proven in various area and ISO 26262 widely used methodology for functional safety. It is expected that the result of this research is used as guidance for construction of semiconductor development process.

• Journal of the Korea Safety Management & Science
• /
• v.12 no.1
• /
• pp.105-111
• /
• 2010

The air logistics process is complex and need many informations because various agencies participate in the logistics service and there are many stakeholders in air logistics. But it is hard to improve the infra of facilities because of an enormous expense, so it needs to simplify air logistics process for growing air freight. When documents are sent, it needs to change the form of documents in spite of same document due to different form by agencies. Also documents are changed even though different documents have same informations. Consequently, errors are increased because the names of the same data are different from each other and stakeholders reproduce the documents. In order to mitigate these problems, we selected documents and analyzed data of documents for the interface optimization in general air logistics process. Next, we unified the names of data and defined contents of data. Also we set the type of the defined data on DB type, and gave the code to the defined data. It made easy to exchange informations among the stakeholders to match documents corresponding with the defined data.

• Journal of KIISE:Software and Applications
• /
• v.41 no.8
• /
• pp.533-544
• /
• 2014

The hardware-based software has been loaded in almost all industrial fields including the embedded system field. As it is increasingly important to control product quality, the more businesses are expending great quality cost. However, most domestic corporations in Korea are bent on spending more money solving problems caused by poor quality rather than prevention of quality loss cost. Therefore, it's time to improve to use quality prevention cost efficiently. As for this, there has been a growing interest in controlling quantitative quality, but the managing activities for quantitative quality require a high maturity process, belonging to Level 4 and 5. So it is necessary that statistical quality control activities should be fulfilled. This study introduces various measures to build up quality control among the process areas of TMMi Level 5 to help establish the high maturity test processes of statistical quality control.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.45 no.2
• /
• pp.46-55
• /
• 2013

Recently, there are growing interests on carbon emissions related in climate change which is worldwide emerging important issue. Some research works are now carrying out in order to reduce the carbon emission in pulp and paper industries by the synthesis of precipitated calcium carbonate using the exhaust carbon dioxide from combustion furnace or incinerator. However, for solving the original problems on carbon emission, we need to consider the analysis of basic methodology on $CO_2$ through the process efficiencies. There are two general tools for carbon emissions; one is the greenhouse gas inventory and the other is $LCCO_2$ method which is applied to particular items of raw materials and utilities in unit process. In this study, the carbon emissions in wood-containing printing paper production line were calculated by using $LCCO_2$ method. The general materials and utilities for paper production, such as fibrous materials, chemical additives, electric power, steam, and industrial water were analyzed. As the results, $Na_2SiO_3$ showed the highest loads in carbon emissions, and the total amount of carbon emissions was the highest in electricity. In the production line of printing paper using de-inked pulp and BTMP, as the mixing ratio of DIP was higher, the carbon emissions were decreased because of high use of electric power in TMP process.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2011.02a
• /
• pp.77-77
• /
• 2011

These days, a growing demand for memory device is filled up with the flash memory and the dynamic random access memory (DRAM). Although DRAM is a reasonable solution for current demand, the universal novel memory with high density, high speed and nonvolatility, needs to be developed. Among various new memories, the magnetic random access memory (MRAM) device is considered as one of good candidate memories because of excellent features including high density, high speed, low operating power and nonvolatility. The etching of MTJ stack which is composed of magnetic materials and insulator such as MgO is one of the vital process for MRAM. Recently, MgO has attracted great interest in the MTJ stack as tunneling barrier layer for its high tunneling magnetoresistance values. For the successful realization of high density MRAM, the etching process of MgO thin films should be investigated. Until now, there were some works devoted to the investigations on etch characteristics of MgO thin films. Initially, ion milling was applied to the etching of MgO thin films. However, ion milling has many disadvantages such as sidewall redeposition and etching damage. High density plasma etching containing the magnetically enhanced reactive ion etching and high density reactive ion etching have been employed for the improvement of etching process. In this work, inductively coupled plasma reactive ion etching (ICPRIE) system was adopted for the improvement of etching process using MgO thin films and etching gas mixes of $CH_4$/Ar and $CH_4$/$O_2$/Ar have been employed. The etch rates are measured by a surface profilometer and etch profiles are observed using field emission scanning emission microscopy (FESEM). The effects of gas concentration and etch parameters such as coil rf power, dc-bias voltage to substrate, and gas pressure on etch characteristics will be systematically explored.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.32 no.2
• /
• pp.120-131
• /
• 2009

Most world-leading companies are aware that Environment and Health and Safety Issues are critical to the product quality and sustainable growth of their company. Environment-friendly efforts are seen in almost all aspects of business operations in an advanced nation. The Extended Producer Responsibility(EPR) and EU Directive on Waste Electric and Electronic Equipment(WEEE) attempt to tackle the growing quantity of WEEE by making producers responsible for the costs of the collection and recycling of their products at the End-of-Life(EOL). To implement the RFID-based integration system for EOL household electric appliances, such as washing machines and refrigerators, we analyzed the process of collecting, recovering, and recycling the EOL products returned from the distribution points. Furthermore, we proposed a soon-to-be process using the RFID-based integration system in the metropolitan recycling center(MRC). This soon-to-be process model is composed of RFID tags, readers, ALEs, applications and several devices. Through the introduction of the RFID-based integration system, we are expecting to see increasing traceability and real-time management for EOL products from customers, and also improvements in valuable reusable materials(VRM) produced from recycling processes.