• Carbon letters
• /
• v.23
• /
• pp.63-68
• /
• 2017

• International Journal of Highway Engineering
• /
• v.18 no.6
• /
• pp.97-104
• /
• 2016

OBJECTIVES : The objective of this research is to develop additives for the modification of Solvent DeAsphalting Residue (SDAR) to be used as pavement materials, and evaluate the performance of asphalt mixture manufactured using the SDAR modified by developed additives. METHODS : The SDAR generally consists of more asphaltenes and less oil components compared to the conventional asphalt binder, and hence, the chemical/physical properties of SDAR are different from that of conventional asphalt binder. In this research, the additives are developed using the low molecular oil-based plasticizer to improve the properties of SDAR. First, the chemical property of two SDARs is analyzed using SARA (saturate, aromatic, resin, and asphaltene) method. The physical/rheological properties of SDARs and SDARs containing additives are also evaluated based on PG-grade method and dynamic shear-modulus master curve. Second, various laboratory tests are conducted for the asphalt mixture manufactured using the SDAR modified with additives. The laboratory tests conducted in this study include the mix design, compactibility analysis, indirect tensile test for moisture susceptibility, dynamic modulus test for rheological property, wheel-tracking test for rutting performance, and direct tension fatigue test for cracking performance. RESULTS : The PG-grade of SDARs is higher than PG 76 in high temperature grades and immeasurable in low temperature grades. The dynamic shear modulus of SDARs is much higher than that of conventional asphalt, but the modified SDARs with additives show similar modulus compared to that of conventional asphalt. The moisture susceptibility of asphalt mixture with modified SDARs is good if, the anti-stripping agent is included. The performance (dynamic modulus, rutting resistance, and fatigue resistance) of asphalt mixture with modified SDARs is comparable to that of conventional asphalt mixture when appropriate amount of additives is added. CONCLUSIONS : The saturate component of SDARs is much less than that of conventional asphalt, and hence, it is too hard and brittle to be used as pavement materials. However, the modified SDARs with developed additives show comparable or better rheological/physical properties compared to that of conventional asphalt depending on the type of SDAR and the amount of additives used.

• Korean Journal of Food Science and Technology
• /
• v.31 no.5
• /
• pp.1188-1195
• /
• 1999

This study was conducted to determin basic mineral compositions, chemical components, description of particle size distribution and whiteness for 32 items of insoluble mineral substances, i.e., 3 items of diatomaceus earth, 1 item of kaolin, 10 items of bentonite, 13 items of acid clay, 3 items of talc and 2 items of perlite. The chemical components and XRD (X-Ray diffractometer) for insoluble mineral substances, were similar with those of the reported references except kaolin. However, whiteness was determined in 90% level for talc, diatomaceus earth and kaolin. The contents of heavy metals in insoluble mineral substances were determined as follows : Pb, $nd{\sim}23.10$ ppm ; Cd, $nd{\sim}0.67$ ppm ; Hg, $nd{\sim}0.58$ ppm ; As, $nd{\sim}1.42$ ppm ; Cu, $nd{\sim}39.35$ ppm. These data were significanty lower than the references.

• Applied Chemistry for Engineering
• /
• v.2 no.1
• /
• pp.30-37
• /
• 1991

The production of hydrogen from steam by reduced iron with additives such as CuO, $In_2O_3$, $MoO_3$ and $WO_3$ has been kinetically investigated. It was shown that all additives have a promoting effect on reaction activity in the order of $$MoO_3{\gg}In_2O_3{\sim_=}WO_3{\sim_=}CuO$$. The shrinking core model was applied to predict the complete conversion time and the results were quite comparable with experimental values. The reaction was carried out in a fixed flow reactor packed with reduced iron with 1 wt % of additives under the conditions, $600-750^{\circ}C$, Ar flow rate of 1 L/min and steam partial pressure of 0.085 atm. The apparent activation energies were 14.2, 20.9, 21.3, 22.4 and 27.9 kJ/mol with $MoO_3$, $In_2O_3$, $WO_3$, CuO and without additive, respectively.

• Korean Journal of Materials Research
• /
• v.26 no.4
• /
• pp.173-181
• /
• 2016

In order to use coal tar pitch (CTP) as a raw material for carbon fibers, it should have suitable properties such as a narrow range of softening point, suitable viscosity and uniform optical properties. In this study, raw CTP was modified by heat treatment with three types of polymer additives (PS, PET, and PVC) to make a spinnable pitch for carbon fibers. The yield, softening point, C/H ratio, insoluble yield, and meso-phase content of various modified CTPs with polymer additives were analyzed by changing the type of polymer additive and the heat treatment temperature. The purpose of this study was to compare the properties of CTPs modified by polymer addition with those of a commercial CTP. After the pitch spinning, the obtained green fibers were stabilized and carbonized. The properties of the respective fibers were analyzed to compare their uniformity, diameter change, and mechanical properties. Among three polymer additives, PS220 and PET261 pitches were found to be spinnable, but the carbon fibers from PET261 showed mechanical properties comparable with those of a commercial CTP produced by an air-blowing method (OCI284). The CTPs modified with polymer additive had higher ${\beta}$-resin fractions than the CTP with only thermal treatment indicating a beneficial effect of carbon fiber application.

• Bulletin of the Korean Chemical Society
• /
• v.30 no.2
• /
• pp.319-322
• /
• 2009

Gel polymer electrolytes were prepared by immersing a porous poly(vinylidene fluoride-co-hexafluoropropylene) membrane in an electrolyte solution containing small amounts of polymerizable additive (3,4-ethylenedioxythiophene, thiophene, biphenyl). The organic additives were electrochemically oxidized to form conductive polymer films on the electrode at high potential. With the gel polymer electrolytes containing different organic additive, lithium-ion polymer cells composed of carbon anode and LiCo$O_2$ cathode were assembled and their cycling performances were evaluated. Adding small amounts of thiophene or 3,4-ethylenedioxythiophene to the gel polymer electrolyte was found to reduce the charge transfer resistance in the cell and it thus exhibited less capacity fading and better high rate performance.

• Journal of Environmental Science International
• /
• v.11 no.3
• /
• pp.235-240
• /
• 2002

The blocks using flyash were prepared in this study. The characteristic of sound absorption of flyash block was investigated. It was revealed that the chemical additives and flyash played an important role to determine the characteristic of sound absorption. Chemical additive affects the capability of sound absorption while flyash affects the characteristic of sound absorption, i.e. high value of the sound absorption coefficient at the specific frequencies(1KHz and 2KHz). The flyash block showed higher sound absorption coefficient than that of the commercial concrete block having carpet on the surface. It was also shown that the sound absorption coefficient increases with increase of the content of flyash in the block. However, it was found that the 70wt% of flyash in the flyash block was the optimum content to obtain the highest sound absorption coefficient.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2003.07a
• /
• pp.791-794
• /
• 2003

To synthesize $Gd_{2}O_{3}:Eu$ phosphor powder of nano size and high luminescence efficiency under UV (ultraviolet) and VUV (vacuum ultraviolet) light, organic additives such as citric acid and ethylene glycol and $Na_{2}CO_{3}$ flux were introduced in large-scale spray pyrolysis and critical conditions for forming nano-sized particles were investigated. The $Gd_{2}O_{3}:Eu$ phosphor particles prepared from solutions with organic additives such as citric acid and ethylene glycol had micron size and spherical shape. However, the particles prepared from polymeric precursor solution with $Na_{2}CO_{3}$ flux had nano size and non-aggregation characteristics. The as-prepared spherical particles with micron size turned into nano-sized particles during post-treatment by recrystallization process. The nano-sized $Gd_{2}O_{3}:Eu$ phosphor particles showed higher brightness than the commercial $Y_2O_3:Eu$ phosphor product under both UV light of 254nm and VUV light of 147 nm.

• Korean Chemical Engineering Research
• /
• v.48 no.3
• /
• pp.375-381
• /
• 2010

Cetane number of diesel fuel for compression ignition engine is one of main properties for fuel ignition quality. Recently the cetane index has been replaced the cetane number in order to resolve the disadvantage of CFR engine test, but these two value have slightly difference values due to addition of various additives. In this study, we analyzed the cetane number, derived cetane number and cetane index for diesel fuel which was blended with various ratios of biodiesel, kerosene and cetane improver as additives. As a result, Cetane number showed the similar value with derived cetane number, but cetane index showed quite different value with cetane number when biodiesel and cetane improver were used as additives.

• Journal of Veterinary Clinics
• /
• v.22 no.2
• /
• pp.125-129
• /
• 2005

This experiment was conducted for the development of oriental feed additives in broiler chicks. It conducted experiment to investigate the effect of $1\%$ dietary supplementation of oriental feed additives containing oriental herbal medicines such as Saururus Chnensis B.(S. chnensis) and Carthamus Tinctorius L.(C. tinctorius) on growth performance, and physicochemical properties in broiler chicks. The results of this study demonstrated that chicks feed $1\%$ oriental feed additives decreased feed gain, and death rates compared with control treatment. Weight gain and meat color were higher in the $1\%$ supplement group than control. The supplementation of $1\%$ oriental feed additives increased unsaturated fatty acid, and reduced crude fat in the broiler chicks compared with those of control. In conclusion, this study implied that oriental feed additives containing oriental herbal medicines such as S. Chnensis and C. Tinctorius were effective in improving broiler chicks on growth performance, physical-chemical properties and is highly recommended for increasing economic returns.