• Resources Recycling
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• v.4 no.3
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• pp.19-25
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• 1995

A Study on the recovery of the valuable metals(Vanadium Molybdenium) was carried out using spent catalysts originated from desulfurizing process of oil refinery. Experiments consisted of pre-roasting for Sulfur and Carbon removal, soda roasting and leaching for the extraction of valuable metals, and selective precipitation of Vanadium and Molybdenium. Effects of temperature and time in roasting for Sulfur removal, of $Na_2CO_3$ concentrations in soda roasting, and of pulp density, temperature and time in leaching were investigated for the recovery of Vanadium and Molybdenium. A optimum condition having over 85% in yield of Vanadium and Molybdenium was found. In the selective precipitation, more than 98% of Vanadium and Molybdenium were obtained by the variation of pH and concentration of additives.

• The Korean Journal of Food And Nutrition
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• v.27 no.1
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• pp.89-98
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• 2014

In this study, soybean is used to produce soymilk according to various extracting methods and heating time. Specifically, the soy slurry is being filtered before being heated, or heated before being filtered. Following that the soymilk produced is freeze-dried to be powdered, and then, the quality characteristics of the powdered soymilk are mutually compared to determine the applicability of various food additives. The freeze-dried soymilk powder shows 2.03~6.35% of moisture content, and in terms of unit quantity, retained more proteins, which suggests that the ratio of protein extraction is higher than any other nutrients. Accordingly, the protein coefficient is significantly higher in soymilk powder being heated and processed than in raw soybeans. In particular, protein coefficient is the highest in the soymilk which is heated for 20 minutes before being filtered (SHBF20). The longer the heating time was, the trypsin inhibitor (TI) tended to be far less active. Such an inactivation seems to be more apparent in the "SHAF" soymilk powder than "SHBF" soymilk powder. Because protein had to be denaturated by heating for soymilk, the nitrogen solubility index (NSI) of soymilk powder is decreased considerably, while the protein digestibility, water absorption, emulsification and foaming activity all increase. Oil absorption tends to decrease slightly. As discussed above, the soymilk heated for 10 minutes after being filtered (SHAF10) and the soymilk heated for 20 minutes before being filtered (SHBF20) show optimum processing conditions for soymilk powder.

• Journal of Adhesion and Interface
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• v.24 no.4
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• pp.131-135
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• 2023

Lecithin self-assembles into reverse spherical micelles in organic solvents as an amphiphilic molecule. When additives such as bile salts and water are introduced into lecithin solutions, it induces structural changes in the molecular form of lecithin, leading to the transformation into reverse cylindrical micelles. In this study, we observe the rheological changes of lecithin/bile salt mixtures in a decane system after the addition of water. The resulting mixtures exhibit high viscosity and characteristics of viscoelasticity, suggesting potential applications in various fields such as drug delivery and edible oil gels.

• Applied Chemistry for Engineering
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• v.27 no.6
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• pp.583-589
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• 2016

Lubricant additives including zinc dialkyldithiophosphate (ZDDP) containing metal have been widely used due to the advantage of very low cost, but they can generate impurities such as ash. In this work, ZDDP containing metals was partially replaced with bis[3-(dialkyloxyphosphorothionyl) thio-2-methylpropanyloxy] butane (BAP4s) which was synthesized conveniently and effectively from alkanediol without any metal components. Also, the wear resistance property of synthesized BAP4s were studied. Wear scar diameter (WSD) values of BAP4s with butyl, octyl, decyl, dodecyl or tetradecyl groups were also measured by four-ball test. As the length of the alkyl group increased from 4 to 8, the WSD value of BAP4s decreased rapidly from 0.59 to 0.45 mm, but from 8 to 14, the value increased very slowly from 0.45 to 0.50 mm. Thus, among all BAP4s, B8P4 having BAP4 with the octyl group, showed the lowest WSD value. Furthermore, the WSD values were measured in a lubricant base oil mixed with a 0.50 percent concentration (w/w) of either BAP4 or ZDDP. The former was 0.55 mm, and the latter was 0.45 mm. The thermal stability and tribofilm formation peroperty were also measured by thermogravimetric analyzer (TGA) and energy-dispersive X-rays spectroscopy (EDS), respectively.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.11
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• pp.1767-1775
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• 2013

The purpose of this study is to investigate the total polyphenol and antioxidant activities of radish buds (Raphanus sativus L.) based on sprouting periods and extraction solvents in order to present basic data that are needed for using the radish buds as functional food material. The antioxidant activities were assessed by using various antioxidant models (DPPH, TBARS, Rancimat method, POV). The total polyphenol contents according to the extraction solvents were 84.11 and 296.51 mg/g, and the ethanol extract on day 4 of showed the highest value as 296.51 mg/g. As for DPPH radical-scavenging activity, on the day 4 of sprouting, water extracts indicated the highest scavenging activity by 86.67%, and the acetone extracts indicated a rather low scavenging activity as 77.23%. As for TBARS measurement of the radish bud extracts on day 4 of sprouting the extract of 70% ethanol was highest (71.48%). On day 8 of sprouting the TBARS value was increased and the methanol extract was highest (78.99%). As for the oxidative induction period on day 4 of sprouting in Rancimat measurement, the methanol extract was highest (6.07 hours) on day 4 and the antioxidant index was 1.16. On day 12 of sprouting, the general oxidative induction period tended to be reduced to 5.25 to 5.91 hours. In the peroxide value measurement on day 4 of sprouting and beginning of the storage, the extracts showed no difference between 3.02 meq/kg oil and 4.12 meq/kg oil, and on the day 60 of storage, the water extract (43.83 meq/kg oil) and the methanol extract (45.42 meq/kg oil) were lowest with higher antioxidant effect. In conclusion, the radish bud extract with higher total polyphenol contents and antioxidant activities may serve as functional material for food additives, such as natural antioxidants and food preserving agents.

• Journal of Advanced Marine Engineering and Technology
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• v.39 no.6
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• pp.620-625
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• 2015

In an effort to reduce the onset of global warming, the International Maritime Organization Marine Environment Protection Committee (IMO MEPC) proposed the reduction in ship speeds as a way of lowering the proportion of carbon dioxide ($CO_2$) in the Green House Gas emissions from ships. To minimize fuel costs, shipping companies have already been performing slow steaming for their own fleets. Specifically, the slow steaming approach has been adopted for most ocean-going container lines. In addition, because of the increased marine fuel cost that is required to enable increased capacity, there is an urgent need for more advanced fuel-saving technologies. Therefore, in this present study, we propose a fuel-cost reduction method that can improve the performance of diesel engines. We introduce a predetermined amount (0.025% of the amount of fuel used) of fuel additive (oil-soluble calcium-based organometallic compound). For improved experimental accuracy, as the test subjects, we utilize a large two-stroke diesel engine installed in land plants. The loads of the test engine were classified as low, medium, and high (50, 75, and 100%, respectively). We compare the engine performance parameters (power output, fuel consumption rate, p-max, and exhaust temperature) before and after the addition of fuel additives. Our experimental results, confirmed that we can realize fuel-cost savings of at least 2% by adding the fuel additive in low load conditions (50%). Likewise, the maximum combustion pressure was found to have increased. On the other hand, we observed that there was a reduction in the exhaust temperature.

• Applied Chemistry for Engineering
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• v.8 no.3
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• pp.425-429
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• 1997

Polyisobutenylsuccinic anhydride(PIBSA), an intermediate for the lubricating oil additive, was prepared by the reaction of polyisobutylene(PIB) with maleic anhydride (MA). The functionality, which indicates the extent of reaction of PIB-a and MA, was determined in the various reaction conditions : fuctionality was 0.98 under the reaction conditions of no solvent for 12 hours at $190^{\circ}C$, 0.21 in benzyl alcohol solvent for 12 hours at $190^{\circ}C$, and 0.03~0.20 with various Lewis acids such as $AlCl_3$, $SnCl_4$, $Et_2AlCl$, and $TiCl_4$. The fuctionality also depended on the structure of PIBs. As ${\alpha}$-olefin content (exo-form) in PIB increased, the fuctionality had a higher value. The structure of PIBSA prepared from PIB and MA was determined with FT IR and $^1H$ NMR spectroscopy. Two strong anhydride IR bands at 1782 and $1855cm^{-1}$ were obserbed and two IR bands at 1639 and $897cm^{-1}$ for unsaturated groups of PIB disappeared. The presence of the anhydride was difficult to find by $^1H$ NMR spectroscopy because the anhydride protons gave relatively small peaks over a 2.0~3.0 range. Polyisobutenylsccinimide (PIBSI), a lublicating oil additive, was prepared by the reaction of PIBSA with diaminoethane.

• Applied Chemistry for Engineering
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• v.31 no.4
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• pp.416-422
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• 2020

In this study, eco-friendly biodegradable materials were prepared using poly(lactic acid) (PLA), poly(butylene adipate-co-terephthalate) (PBAT), and hydrogenated castor oil power (HCO) as an additive. The prepared PLA/PBAT/HCO blended films were characterized by the scanning electron microscope (SEM) and fourier-transform infrared spectroscopy (FT-IR). The results of SEM analysis indicated that PLA/PBAT (8 : 2) blended films added HCO showed no rough area, crack, or large agglomeration when compared with those adding various additives (12-hydroxy stearic acid (12HSA) and cellulose). The FT-IR results indicated the presence of specific peak of HCO in the PLA/PBAT blended films, and its peak intensity increased with increasing HCO content (0~5.0 wt%). Tensile strength, elongation at break, and water barrier and thermal properties of the prepared PLA/PBAT/HCO blended films were also investigated, indicating that the physical and thermal properties was improved more than three times by the addition of HCO. The biodegradability test in soil revealed that the prepared biodegradable materials were degraded by about 6.0~20% after 90 days.

• Journal of the Korean Applied Science and Technology
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• v.37 no.6
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• pp.1678-1686
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• 2020

This study attempted to derive the possibility of using wood pellet using rice husk, which is an agricultural byproduct, and tried to improve the lower calorific value of rice hulls thorough expansion technology and combustion additives. In the physical and chemical analysis of rice husk, the result was obtained that the chlorine content was 0.09%, which did not meet the wood pellet quality standard of Korea. When making rice hulls into expanded rice husk through the expansion technology, the chlorine content decreased, resulting in a product of 0.02%, which is equivalent to the wood pellet standard of Korea, and the calorific value was also increased to 4,280 kcal/kg compared to the existing 3,780 kcal/kg. To obtain a product of 5,000 kcal/kg or more, borax, hydrogen peroxide, and sodium hydroxide was used as combustion improver. However the improvement in calorific value was insufficient. After conversion to coffee oil path using coffee grounds, which is a waste resource biomass, it is mixed into an expanded rice husk, and when the product is analyzed, the coffee oil 15 wt% mixed product shows an excess of 4,949 kcal/kg. When using rice husk, an agricultural byproduct, as wood pellets, it is considered desirable to use waste resources to improve the calorific value, and according to the results of this study, when mixing coffee oil, rice husk can be sufficiently used as wooden pellets.

• Applied Chemistry for Engineering
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• v.29 no.4
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• pp.405-412
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• 2018

Three types of bis[3-(dialkyloxylphosphorothionyl) thio-2-methylpropanyloxy]alkane (BAPA) drived from alkane diol were synthesized. The principal chain of each BAPA had a different carbon number, i.e., 6, 9, and 11. The three types of synthesized BAPA were compared to zinc dialkyl dithiophosphates (ZDDPs) in terms of abrasion resistance. A four-ball test was conducted to evaluate the anti-abrasion performance of the synthesized BAPA according to the length of the principal carbon chain. Each product was added to an additive at a concentration of 1% of the base oil weight, and the wear scar diameter (WSD) was measured as 0.472, 0.459, and 0.480 mm, respectively. Among the BAPA compounds, dialkyl dithiophosphoric acid (DDP), which is the side chain of bis[methacryloyloxy] nonane (BMOO9), was synthesized by varying the carbon number, i.e., 4, 8, and 12, and subsequently the 4-ball test was carried out. The WSD was determined as 0.537, 0.459, and 0.531 mm, respectively. As a result, it was found that when a side chain is short, a thin film is formed. In contrast, a long side chain hindered the formation of a film, and hence the best result was achieved when the carbon number was 8. As for the ZDDPs, the WSD was determined to be 0.563 mm, when measured under the same conditions. The measurements confirm that the synthesized BAPA compounds are superior to the ZDDPs as abrasion resistance additives.