• 한국세라믹학회지
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• 제37권5호
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• pp.453-458
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• 2000

Glasses showing the composition of blast furnace slag were made in the laboratory, and the effect of the chemical composition on the latent hydraulic activity of the slags was examined. The latent hydraulicity was greatly influenced by the composition change, the optimal characteristic of the hydraulicity was achieved at the slag composition of 47CaO:20Al2O3:33SiO2. The content of CaO and Al2O3 were not equivalent to the hydraulic activity of the slags as the b-formula (KS L 5210) indicates. Good latent hydraulicity was shown when Al2O3 was richly contained at the high (CaO＋Al2O3):SiO ratio, while the more the MgO content was, the more negative the result turned out.

• Animal Bioscience
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• 제36권6호
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• pp.908-919
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• 2023

Objective: Information about the chemical composition of cassava-based feed ingredients is needed to accurately formulate animal diets. A study was conducted to determine the chemical composition of cassava-based feed ingredients and to test the hypothesis that there is variation in chemical composition among cassava products originating from different South-East Asian countries. Methods: Sources of dried peeled and unpeeled cassava roots, cassava chips, cassava meal, high-ash cassava meal, and cassava residue were used. All samples were analyzed for dry matter, gross energy, nitrogen, amino acids (AA), acid-hydrolyzed ether extract (AEE), ash, minerals, total starch, insoluble dietary fiber, and soluble dietary fiber. Samples of peeled and unpeeled cassava roots, cassava chips, and cassava meal were also analyzed for sugars. Results: High-ash cassava meal had greater (p<0.05) dry matter and ash, but lower (p<0.05) total starch and gross energy than all other cassava products. Peeled cassava roots, unpeeled cassava roots, and cassava chips had greater (p<0.05) total starch than the other cassava-based ingredients. Cassava residue had greater (p<0.05) concentrations of lysine, insoluble dietary fiber, and soluble dietary fiber compared with the other cassava products, but tryptophan and glutamic acid were greater (p<0.05) in peeled cassava roots, cassava chips, and cassava meal samples compared with the other ingredients. Concentration of most minerals was greater (p<0.05) in high-ash cassava meal than in the other cassava products. Conclusion: Cassava-based ingredients sold as peeled roots, unpeeled roots, chips, or meal have chemical compositions that are not different from each other, and peeling has little impact on chemical composition. High-ash cassava meal has lower nutritional quality compared with other cassava products due to low starch and gross energy. The high fiber content in cassava residue makes this ingredient more suitable for ruminants and sows than for younger pigs or poultry.

• 열처리공학회지
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• 제16권3호
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• pp.127-133
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• 2003

The effect of chemical composition on the microstructural change and tensile property in TRIP-assisted steels with different chemical composition was investigated by using SEM, TEM, XRD and UTM. As a result of microscopic observation, the morphology of retained austenite could be identified as two types; a granular type in a steel containing higher Si and a film type in a steel having higher C. For the case of higher C-containing steel with a tensile strength of 860 MPa and a total elongation of 38%, film-typed retained austenite could be observed between lath bainitic ferrite. Actually, metastable retained austenite was a requisite for the good formability, which means that chemical composition plays a significant role in the microstructure and tensile property of TRIP-assisted steels. With respect to tensile property, the steels containing suitable Si and Mn, respectively, showed a typical TRIP effect in stress-strain curve, while a steel containing higher Mn content exhibited the similar behavior shown in dual phase steel.

• 한국자동차공학회논문집
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• 제15권3호
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• pp.106-113
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• 2007

The effect of chemical composition on the microstructural change and tensile property in TRIP-assisted steels with different chemical composition was investigated by using SEM, TEM, XRD and UTM. As a result of microscopic observation, the morphology of retained austenite could be identified as two types : a granular type in a steel containing higher sillicon and a film type in a steel having higher carbon. For the case of higher carbon-containing steel with a tensile strength of 860 MPa and a total elongation of 38%, film-typed retained austenite could be observed between lath bainitic ferrite. Actually, metastable retained austenite was a requisite for the good formability, which means that chemical composition plays a significant role in the microstructure and tensile property of TRIP-assisted steels. With respect to tensile property, the steels containing suitable silicon and manganese, respectively, showed a typical TRIP effect in stress-strain curve, while a steel containing higher manganese content exhibited the assimilar behavior shown in dual phase steel.

• 열처리공학회지
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• 제2권4호
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• pp.40-46
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• 1989

The hardenability of steel is related to its chemical composition. About this relationship, multiple regression analysis of hardenability data was proposed to explain the effect of chemical composition on a hardenability of steel. To establish the formula for calculation hardenability, given hardenability curve(U.S.S. Atlas) were quantitatively analyzed by multiple regression analysis program of computer. The established hardenability model was applied to predict the hardenability of commercial steel fair well. The effect of chemical composition was also expressed quantitatively.

• Journal of Welding and Joining
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• 제18권5호
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• pp.90-97
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• 2000

Effect of alloy elements on joinability of insert metal for liquid phase diffusion bonding of heat resistant alloys was investigated in this study. Also, optimum chemical composition of insert metal was explained using interpolation method. The insert metals utilized was commercial Ni-base amorphous foils and newly developed Ni-base filler metals with B, Si and Cr in this study. Melting point and critical interlayer width(CIW) decreased with increasing additional amount of B, Si and Cr, melting point lowering element of the insert metal. Optimized chemical composition of insert metals could be estimated by interpolation method. The optimum amount of B, Si, Cr addition into the insert metal were found to be about 3%, 4% and 3%, respectively. The measured characteristic values, melting point, microhardness in the bonded interlayer and CIW of the insert metals were the almost identical to ones of the calculated results by interpolation method.

• 한국대기환경학회지
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• 제15권1호
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• pp.13-22
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• 1999

This study is carried out to investigate the chemical composition of atmospheric deposition in Cheju Island, Korea. For this purpose, dustfall matter samples are collected by dust jar from August, 1995 to July, 1996 at five sampling sites and total suspended particulate matters (TSP) and rain are also collected at one site from October, 1995 to July, 1996. All the samples collected are analyzed, and then the information of the 19 chemical species and deposition amount of each species is obtained. These data are used to determine the regional trends in dustfall chemistry and deposition, and compare the characteristics of chemical compositions between dustfall, TSP and rainwater.

• 한국세라믹학회지
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• 제26권4호
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• pp.521-531
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• 1989

The dependence of the chemical durability of simulated waste glasses containing the simplified waste similar to the SRP waste on compositions of host glasses, amounts of waste loading, and kinds of leachants has been investigated as a basic study on the waste immobilization through vitrification. The maximum limit of the amount of waste loading for glassforming with the host sodium borosilicate glasses selected in this study was 50wt%. The chemical durability of waste glasses whose host glass belonged to the immiscible composition region was much higher than that of waste glasses whose host glass belonged to the miscible composition region. The former waste glass showed lower chemical durability in deionized and silicate waters than in brine, while the latter glass showed the lowest chemical durability in deionized and silicate waters than in brine, while the latter glass showed the lowest chemical durability in silicate water. It was also observed that the total leaching rates in brine were noticeably small in comparison with those in other solutions. The composition of the host borosilicate glass which was suitable for the treatment of the waste through vitrification was found to be 25 Na2O-5B2O3-70SiO2(wt.%).

• Asian-Australasian Journal of Animal Sciences
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• 제30권12호
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• pp.1718-1723
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• 2017

Objective: The study explored the dynamics of shearing force and its correlation with chemical compositions and in vitro dry matter digestibility (IVDMD) of stylo. Methods: The shearing force, diameter, linear density, chemical composition, and IVDMD of different height stylo stem were investigated. Linear regression analysis was done to determine the relationships between the shearing force and cut height, diameter, chemical composition, or IVDMD. Results: The results showed that shearing force of stylo stem increased with plant height increasing and the crude protein (CP) content and IVDMD decreased but fiber content increased over time, resulting in decreased forage value. In addition, tall stem had greater shearing force than short stem. Moreover, shearing force is positively correlated with stem diameter, linear density and fiber fraction, but negatively correlated with CP content and IVDMD. Conclusion: Overall, shearing force is an indicator more direct, easier and faster to measure than chemical composition and digestibility for evaluation of forage nutritive value related to animal performance. Therefore, it can be used to evaluate the nutritive value of stylo.

• Asian-Australasian Journal of Animal Sciences
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• 제19권12호
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• pp.1737-1741
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• 2006

The aim of this study was to provide basic information to allow improved nutritional management for velvet production by investigating the effects of dietary protein levels on dry matter intake and production and chemical composition of velvet antler in spotted deer (Cervus nippon). Twenty-four spotted deer stags were assigned to 4 unreplicated groups, Control (15% CP in diet, higher dry matter), CP10 (10% CP), CP15 (15% CP) and CP20 (20% CP). The velvet antlers were harvested from each stag on the 55th day after casting of the buttons from the previous set, measured for their size and weight, and the chemical composition of each antler was determined in three sections (top, middle, and base). Dry matter (DMI) and crude protein (CPI) intake were highest (p<0.05) for the Control and increased progressively (p<0.05) with increasing dietary protein level. Although not significant, mean length and girth of the main antler beam tended to be larger in either left or right beam with increasing protein level in the diet, longest in CP20 and shortest in CP10. Velvet antler production was lowest in CP10 and highest in CP20, which differed significantly (p<0.05). Only negligible differences were found between groups in chemical composition. It is concluded that dietary protein clearly influenced dry matter intake and velvet antler production, whereas there was comparatively little effect of dietary protein on chemical composition of antler in spotted deer.