• Textile Coloration and Finishing
• /
• v.10 no.1
• /
• pp.11-19
• /
• 1998

For the purpose of standardization and practicability of dyeing by natural dyes, the mordanting and dyeing properties of cochineal and carminic acid were studied. Appropriate extraction, dyeing and mordanting condition of cochineal were determined, and the effect of mordanting method on dye uptake and color fastness of dyed fabric was investigated. The maximum absorbance of cochineal solution was 495nm, carminic acid was 533nm and 577nm. The color of carminic acid solution was affected by pH 6~9. The optimum temperature to extract cochineal was $80-100^\circ{C}$ and dyeing solution for 1 hour. And effective dyeing time to silk was 60min. Effective mordanting temperature was $80^\circ{C}$, and its time was 30min. In case mordants concentration, the maximum absorbance of Sn solution was 3%, K, Cu and Cr were in 1%. K/S value of dyeing fabrics was recoginazed by mordant treatment, specially Fe, Sn, Al, Cu. In the case of cochineal light fastness was increased by mordant treatment, specially Fe treatment. Perspiration fastness was good in acidic solution than in alkaline solution and perspiration fastness of cochineal was poor. Fastness of abrasion and dry-cleaning were good and these fastness improvement were generally effective for post-mordanting treatment.

• Textile Coloration and Finishing
• /
• v.26 no.3
• /
• pp.263-271
• /
• 2014

The purpose of this study is to investigate the dyeability of silk fabrics with Humulus japonicus (Hwansam) extract which is a kind of weeds that grows wild in the suburbs. In the research, the general extract method was conducted with the extract from fresh herb of root-removed Humulus japonicus while we investigated the optimal dyeing conditions and dyeability depending on the changes of the kind of mordants, methods and temperature. The functional properties such as antibacterial activities, deodorization and UV protection were also reviewed. The ideal output, as a result, was shown at 100% of dye concentration, $90^{\circ}C$ of dyeing temperature and 40 minutes of dyeing time while in terms of dye uptake depending on the kind of mordants and methods, it was found that among four mordants of $SnCl_2$, $AlK(SO_4)_2$, $CuSO_4$, and $FeSO_4$ post-mordanting with $FeSO_4$ showed the best result. Color fastness to washing, dry cleaning and rubbing was found strong at grade 4-5 and the grade to light was as good as 3 while to perspiration was good at 4-5 as well. In aspects of functional properties, it showed excellent results of 99% deodorization rate, 98% UV protection rate and 99.9% bacterial reduction against Staphylococcus aureus.

• The Transactions of the Korean Institute of Electrical Engineers P
• /
• v.66 no.2
• /
• pp.94-97
• /
• 2017

A method of improving the anti-fouling characteristics of porcelain insulators was proposed in this study. Functional coating was performed as a method of reducing the surface contamination of the porcelain insulators. The functional coating was applied on a ceramic substrate, which has the same material as the porcelain insulators. After coating the ceramic substrate 2, 3, 4, and 5 times alternately in the horizontal and vertical directions, the surface characteristics according to the thickness of the coating film were analyzed. The optimal process was selected to coat the surfaces of the post insulators and long rod insulators, which are the representative porcelain insulators. After coating, heat treatment was performed for 1 hour at $200^{\circ}C$ in a furnace to secure the durability of the coating film. Compared to the uncoated insulators, the insulators with the functional coating showed significantly improved anti-fouling characteristics as well as excellent adhesion to the coated insulator surface.

• KIEAE Journal
• /
• v.10 no.6
• /
• pp.105-114
• /
• 2010

As children are known to touch and chew everything, green cleaning procedures are an important step in preventing children from ingesting harmful toxins. The objectives of this study are to develop a new, self-evaluation checklist and to suggest design recommendations which comply with easy, adaptable, economical ways to improve the eco-friendly indoor environment of Korean childcare facilities. The information compiled during this study was collected through literature review and internet surveys1) from July, 2009 to February, 2010. The results of this study show that the current Korean childcare accreditation system and practices emphasize clean building interiors, policies for sanitation and cleanliness, and control of humidity and lighting. On the other hand, the information provided by green-building rating systems from GBCC, LEED, and GBTool offers additional and comparative details regarding indoor environment quality and standards regarding the IAQ performance and management plan, ventilation and thermal comfort systems, views from windows, acoustics, and lighting. In conclusion, this document provides an appropriate and easy-to-follow, self-evaluation checklist composed of eight criteria and 51 practical items. This study also provides the design recommendations composed of 27 practical ideas focusing on interior elements. Both the checklist and design recommendations I have suggested can be a post-occupancy tool for evaluating eco-healthy facility standards as well as tips for continuing to maintain eco-healthy childcare facilities.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.13 no.2
• /
• pp.131-136
• /
• 2000

We have investigated the slurry induced metallic contaminations of undoped and doped silicate oxides surface on CMP cleaning process. The metallic contaminations by CMP slurry were evaluated in four different oxide films, such as plasma enhanced tetra-ethyl-orthyo-silicate glass(PE-TEOS), O3 boro-phos-pho-silicate glass(O3-BPSG), PE-BPSG, and phospho-silicate glass(PSG). All films were polished with KOH-based slurry prior to entering the post-CMP cleaner. The Total X-Ray fluorescence(TXRF) measurements showed that all oxide surfaces are heavily contaminated by potassium and calcium during polishing which is due to a CMP slurry. The polished O3-BPSG films presented higher potassium and calcium contaminations compared to PE-TEOS because of a mobile ions gettering ability of phosphorus. For PSG oxides, the slurry induced mobile ion contamination increased with an increase of phosphorus contents. In addition, the polishing removal rate of PSG oxides had a linear relationship as a function of phosphorus contents.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.25 no.8
• /
• pp.1484-1492
• /
• 2001

For the purpose of standardization and practicability of dyeing by natural dye, the mordanting and dyeing properties of Lithodpermum officinale were studied. Appropriate extraction, dveing and mordanting conditions of Lithodpermum officinale were determined, and the effect of mordanting no dye uptake and color fastness of dyed fabric was investigated. The maximum absorbances of Lithopermum officinale solution were at 521 and 561 mn, shikonin solution were 517 and 556 mn. According to the UV-VIS spectroscopy of shikonin solution showed batho chromic shift with the increase of temperature and the absorbance of shikonin solution increased with the increase of temperature. The color of Lithodpermum officinale solution was affected by pH 8∼9, they became dark, reduced reddish and bluish. The optimum conditions for extraction from Lithodpermum officinale were at 80$\^{C}$ and for 1 hour and at 25$\^{C}$ for 24 hours. And effective dyeing conditions with silk fabric were temperature at 80∼100$\^{C}$ and period for 60min. K/S value and color fastness of dyed fabrics were increased by mordanting treatment. In the case of Lithodpermum officinale light fastness was better than Sophora japonica, Gaesalpinia Sappan, Rhusjara,. Cochineal dyeing fabrics. Perspiration fastness of Lithodpermum officinale were good. Fastness of abrasion and dry-cleaning were good these fastness improvement were generatlly effected by post-mordanting treatment.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2004.07a
• /
• pp.20-23
• /
• 2004

As the integrated circuit device shrinks to the smaller dimension, the chemical mechanical polishing(CMP) process was required for the global planarization of inter-metal dielectric(IMD) layer with free-defect. However, as the IMD layer gets thinner, micro-scratches are becoming as major defects. Chemical-Mechanical polishing(CMP) of conductors is a key process in Damascene patterning of advanced interconnect structure. The effect of alternative commercial slurries pads, and post-CMP cleaning alternatives are discuss, with removal rate, scratch dentisty, surface roughness, dishing, erosion and particulate density used as performance metrics. Electroplated copper deposition is a mature process from a historical point of view, but a very young process from a CMP perspective. While copper electro deposition has been used and studied for decades, its application to Cu damascene wafer processing is only now gaining complete acceptance in the semiconductor industry. The polishing mechanism of Cu-CMP process has been reported as the repeated process of passive layer formation by oxidizer and abrasion action by slurry abrasives. however it is important to understand the effect of oxidizer on copper passivation layer in order to obtain higher removal rate and non-uniformity during Cu-CMP process. In this paper, we investigated the effects of oxidizer on Cu-CMP process regarding the additional volume of oxidizer.

• Tribology and Lubricants
• /
• v.34 no.6
• /
• pp.226-234
• /
• 2018

Copper chemical mechanical planarization (CMP) has become a key process in integrated circuit (IC) technology. The results of copper CMP depend not only on the mechanical abrasion, but also on the slurry chemistry. The slurry used for Cu CMP is known to have greater chemical reactivity than mechanical material removal. The Cu CMP slurry is composed of abrasive particles, an oxidizing agent, a complexing agent, and a corrosion inhibitor. Citric acid can be used as the complexing agent in Cu CMP slurries, and is widely used for post-CMP cleaning. Although many studies have investigated the effect of citric acid on Cu CMP, no studies have yet been conducted on the interfacial friction characteristics and step height reduction in CMP patterns. In this study, the effect of citric acid on the friction characteristics and step height reduction in a copper wafer with varying pattern densities during CMP are investigated. The prepared slurry consists of citric acid ($C_6H_8O_7$), hydrogen peroxide ($H_2O_2$), and colloidal silica. The friction force is found to depend on the concentration of citric acid in the copper CMP slurry. The step heights of the patterns decrease rapidly with decreasing citric acid concentration in the copper CMP slurry. The step height of the copper pattern decreases more slowly in high-density regions than in low-density regions.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.37 no.3
• /
• pp.337-344
• /
• 2024

This work focuses on improving the light-harvesting efficiency of thin-film silicon solar cells through innovative multi-architecture surface modifications. To create a regular optical structure, a lithographic process was performed to form it on a glass substrate through various etching processes, from Etch-1 to Etch-3. AZO was deposited on top of the structures and re-etched to create a multi-architectural surface. These surface-modified structures improved the light absorption and overall performance of the solar cell through changes in optical and physical properties, which we will analyze. In addition, we investigated the effect of post-cleaning on the etched glass structures through EDX analysis to understand the mechanism of the etching action. The results of this study are expected to provide important guidelines for the design and fabrication of solar cells and other photovoltaic devices.

• Applied Chemistry for Engineering
• /
• v.29 no.1
• /
• pp.10-17
• /
• 2018

POU (point of use) scrubbers were applied for the treatment of waste gases including PFCs (perfluorocompounds) exhausted from the CVD (chemical vapor deposition), etching, and cleaning processes of semiconductor and display manufacturing plant. The GWP (global warming potential) and atmosphere lifetime of PFCs are known to be a few thousands higher than that of $CO_2$, and extremely high temperature more than 3,000 K is required to thermally decompose PFCs. Therefore, POU gas scrubbers based on the thermal plasma technology were developed for the effective control of PFCs and industrial application of the technology. The thermal plasma technology encompasses the generation of powerful plasma via the optimization of the plasma torch, a highly stable power supply, and the matching technique between two components. In addition, the effective mixture of the high temperature plasma and waste gases was also necessary for the highly efficient abatement of PFCs. The purpose of this paper was to provide not only a useful technical information of the post-treatment process for the waste gas scrubbing but also a short perspective on R&D of POU plasma gas scrubbers.