Park J.,University of New South Wales |
Kim W.,Korea Interfacial Science and Engineering Institute |
Cho N.,Korea University of Technology and Education |
Lee H.,Korea Interfacial Science and Engineering Institute |
Park N.,Korea Electronics Technology Institute
Green Chemistry | Year: 2016
A sustainable method for reclaiming silicon (Si) wafers from an end-of-life photovoltaic module is examined in this paper. A thermal process was employed to remove ethylene vinyl acetate and the back-sheet. We found that a ramp-up rate of 15 °C min-1 and an annealing temperature of 480 °C enabled recovery of the undamaged wafer from the module. An ecofriendly process to remove impurities from the cell surface was developed. We also developed an etching process that precludes the use of hydrofluoric (HF) acid. The method for removing impurities consists of three steps: (1) recovery of the silver (Ag) electrode using nitric acid (HNO3); (2) mechanical removal of the anti-reflecting coating, emitter layer, and p-n junction simultaneously; and (3) removal of the aluminum (Al) electrode using potassium hydroxide (KOH). The reclaimed wafers showed properties that are almost identical to those of commercial virgin wafers: 180 μm average thickness; 0.5 and 3.7 Ω cm minimum and maximum resistivities, respectively; and 1.69 μs average carrier lifetime. In addition, cells fabricated with the reclaimed wafers showed an efficiency equivalent to that of the initial cells. © The Royal Society of Chemistry 2016.
Rai B.,Tata Research Development And Design Center |
Sathish P.,Tata Research Development And Design Center |
Tanwar J.,Tata Research Development And Design Center |
Pradip,Tata Research Development And Design Center |
And 2 more authors.
Journal of Colloid and Interface Science | Year: 2011
Surface characteristics of complex aluminosilicate minerals like spodumene [LiAl(SiO3)2], jadeite [NaAl(SiO3)2], feldspar [KAlSi3O8], and muscovite [K2Al4(Al2Si6O20)(OH)4]) are modeled. Surface energies are computed for the cleavage planes of these minerals. Adsorption mechanisms of anionic chemisorbing type oleate and cationic physisorbing type dodecylammonium chloride molecules on two different crystal planes, that is (110) and (001), of spodumene and jadeite are studied in terms of the surface-surfactant interaction energies computed using molecular dynamics (MD) simulations. The conclusions drawn from purely theoretical computations match remarkably well with our experimental results. © 2011 Elsevier Inc.
Park H.,Korea Interfacial Science and Engineering Institute |
Kim T.-Y.,Korea Interfacial Science and Engineering Institute |
Woo D.,Korea Interfacial Science and Engineering Institute |
Cho Y.-S.,Hanyang University
Water Science and Technology: Water Supply | Year: 2015
Removal of natural organic matter (NOM) and taste and odor problems in drinking water are a sensitive issue in municipal water treatment plants. This study investigated the effectiveness of ozone (O3) + granular activated carbon (GAC), O3 + hydroperoxide (H2O2) + GAC, and GAC processes using a pilot scale plant to remove NOM and geosmin (50-1,000 ng/L), and 2-methylisoborneol (2-MIB: 50-300 ng/L). In the O3 + GAC process, NOM-related parameters showed an average of 52% dissolved organic carbon (DOC) removal from 2 mg/L DOC influent, 99.3% haloacetic acids (HAAs) removal from 0.097 mg/L HAAs influent, and 100% removal from 0.05 mg/L bromide influent. Taste and odor removal rates were 94-100% for geosmin and 87-100% for 2-MIB. The O3 + H2O2 + GAC process removed an average of 55% DOC, 99.7% HAAs, 100% bromate, 94-100% geosmin, and 93-100% 2-MIB. The GAC process removed 46% DOC, 98.3% HAAs, 100% bromate, 83-100% geosmin, and 81-100% 2-MIB. Based on a comparison of the efficiencies and an economic analysis, the O3 + H2O2 + GAC process was determined to be the optimal system for removing NOM and taste and odor compounds. © IWA Publishing 2015.
Woo D.-S.,Korea Interfacial Science and Engineering Institute |
Hwang B.-G.,Sangmyung University
KSCE Journal of Civil Engineering | Year: 2014
To evaluate the corrosivity of seawater, the SWRO (Sea Water Reverse Osmosis) produced water, and the community tap water were used in this study. Weight loss method and potentiodynamic polarization test were applied to compare the corrosivity between them. Coupons and pipes for the experiments were prepared with the same materials such as carbon steel, zinc, copper, and STS304 achieved in equivalent condition. As a result of experiments, seawater showed constituent ions such as Cl-, SO4 2-, Mg2+, and Ca2+ (in order of abundance), while the SWRO produced water showed lower pH, calcium hardness and alkalinity than the tap water. Since chloride ion, as an acceleration factor of corrosion, was highly detected, the test results of weight loss method and potentiodynamic polarization indicated that release of metal ions and weigh loss were more abundant in the SWRO membrane desalted permeate than in the tap water. Besides, corrosion potential was also lower in SWRO membrane desalted permeate. It represents that the surface of metal could be exposed easily to oxidize in SWRO condition due to low dissolved alkali metal ion of water. © 2014 Korean Society of Civil Engineers and Springer-Verlag Berlin Heidelberg.
Park H.,Korea Interfacial Science and Engineering Institute |
Woo D.-S.,Korea Interfacial Science and Engineering Institute
International Journal of Software Engineering and its Applications | Year: 2014
This study developed a decision support system in a water treatment system capable of supporting the operator to make informed decisions about the best course of action for using multiple water resources. This system consists of a process operation and diagnosis to calculate historical and real-time data to optimize water blending ratios and diagnose each water treatment unit. According to the decision support system, the operator can easily organize calculated and analyzed data and as such can expect long-term operational and analytical benefits in terms of economic, social, and environmental effects in the future. © 2014 SERSC.
Korea Interfacial Science And Engineering Institute | Date: 2010-09-07
The present invention relates to a self-steering device for a railway vehicle, which includes axles installed on a truck supporting a vehicle body of the railway vehicle, wheels, each of which is connected to the axle and has a wheel tread moving on a top surface of a rail and supporting a vertical load of the railway vehicle, and a wheel flange protruding from the wheel tread to prevent the railway vehicle from derailing and being in contact with a lateral surface of the rail during straight movement of the railway vehicle to form an interference section, and guide rollers, each of which is in rolling contact with a top surface edge or a lateral surface of the rail in front or to the rear of the wheel when the railway vehicle enters curved rails and supports a greater transverse load than the interference section. The guide rollers can be directly installed on the railway vehicle or at least one of the vehicle body, the truck, and the axle.