화상인식을 이용한 Al-Si 주조용 합금의 화학조성 예측

정상준,황인규,조인성,김희수 대한금속·재료학회 2019 대한금속·재료학회지 Vol.57 No.3

In this study, we analyzed the chemical composition of Al-Si cast alloys from microstructural images, using image recognition and machine learning. Binary Al-Si alloys of Si = 1~10 wt% were cast and prepared as reference images in the dataset used for machine learning. The machine learning procedure was constructed with Inception V3 model. Repeated training to relate the microstructural images to their chemical composition was carried out, for up to 10,000 steps, to increase the reliability of the analysis. The peaks of similarity existed in the dataset with chemical compositions corresponding to the known target composition. The heights of the peaks became higher and the distribution of similarity became sharper with further training steps. This means that the weighted average of the chemical composition approached the target composition with increasing training steps. The correctness of the analysis increased with training steps up to 10,000, then was saturated. It was found that the chemical composition outside the dataset range could not be analyzed correctly. Analysis of the compositions between the datasets showed incorrect but reasonable results. The reliability of the chemical composition analysis using machine learning and image recognition developed in this study will increase when a vast range of reference images are collected and verified.

Compositional engineering of solution-processed BiVO₄ photoanodes toward highly efficient photoelectrochemical water oxidation

Byun, Segi,Jung, Gihun,Moon, Song-Yi,Kim, Bumsoo,Park, Jeong Young,Jeon, Seokwoo,Nam, Sung-Wook,Shin, Byungha Elsevier 2018 Nano energy Vol.43 No.-

<P><B>Abstract</B></P> <P>While BiVO<SUB>4</SUB> is a promising photoanode for solar-driven photoelectrochemical (PEC) water splitting, fine control of its chemical composition (Bi/V ratio) and modification of its electrical properties via extrinsic doping are necessary to improve its PEC performance. Here, we performed compositional engineering of BVO—varying Bi/V ratio and inclusion of different concentrations of Mo dopants. Through physical and chemical analyses, we found that the materials properties of BiVO<SUB>4</SUB> and its PEC performance were highly sensitive to the chemical composition. Our optimized BiVO<SUB>4</SUB>-based photoanode exhibited the highest photocurrent density among the state-of-the-art SnO<SUB>2</SUB>/BiVO<SUB>4</SUB> heterojunction photoanodes reported in the literature: 2.62 and 4.20mAcm<SUP>−2</SUP> measured at 1.23V vs. a reversible hydrogen electrode for the oxygen evolution reaction and sulfite oxidation reaction, respectively. A complete picture explaining various PEC performances with different chemical compositions via the band structure of BiVO<SUB>4</SUB> has emerged. This work points to the importance of specific control of the chemical composition in achieving highly efficient BiVO<SUB>4</SUB>-based photoanodes, which will guide future research directions in the fabrication of other high performance photoelectrodes.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Highly efficient SnO<SUB>2</SUB>/BiVO<SUB>4</SUB> photoanodes are achieved by engineering its composition. </LI> <LI> The material and PEC properties of BiVO<SUB>4</SUB> are affected by its chemical composition. </LI> <LI> The improved PEC performance is correlated with band alignments of SnO<SUB>2</SUB>/BiVO<SUB>4</SUB>. </LI> <LI> Our optimized sample exhibits superior performance in PEC water oxidation. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Chemical composition of cassava-based feed ingredients from South-East Asia

Fanelli Natalia S,Torres-Mendoza Leidy J,Abelilla Jerubella J,Stein Hans H. 아세아·태평양축산학회 2023 Animal Bioscience Vol.36 No.6

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 cassavabased 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.

Effects of Dietary Protein Level on Dry Matter Intake, and Production and Chemical Composition of Velvet Antler in Spotted Deer Fed Forest By-product Silage

Jeon, B.T.,Kim, M.H.,Lee, S.M.,Moon, S.H. Asian Australasian Association of Animal Productio 2006 Animal Bioscience Vol.19 No.12

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.

Study on Aging Characteristics and Chemical Composition of Hydrogenated Transformer Oil

Yi-Hua Qian,Yi-Bin Huang,Qiang Fu,Zhen-Sheng Zhong 대한전기학회 2013 Journal of Electrical Engineering & Technology Vol.8 No.3

Under the condition of Baader aging, the chemical composition variation and the influence of transformer oil aging on electrical properties such as dielectric loss factor and physicchemical properties such as interfacial tension were studied in the aging precess. Moreover, the correlation between hydrogenated transformer oil electrical and physic-chemical properties and its chemical composition variation were also investigated. The results show that these parameters of physic-chemical and electrical properties of hydrogenated transformer oil relate to each other and have closed correlation with chemical composition.

Study on Aging Characteristics and Chemical Composition of Hydrogenated Transformer Oil

Qian, Yi-Hua,Huang, Yi-Bin,Fu, Qiang,Zhong, Zhen-Sheng The Korean Institute of Electrical Engineers 2013 Journal of Electrical Engineering & Technology Vol.8 No.3

Under the condition of Baader aging, the chemical composition variation and the influence of transformer oil aging on electrical properties such as dielectric loss factor and physic-chemical properties such as interfacial tension were studied in the aging precess. Moreover, the correlation between hydrogenated transformer oil electrical and physic-chemical properties and its chemical composition variation were also investigated. The results show that these parameters of physic-chemical and electrical properties of hydrogenated transformer oil relate to each other and have closed correlation with chemical composition.

Chemical Composition and Antibacterial Activity of Opuntia Ficus-Indica F. Inermis (Cactus Pear) Flowers

Monia Ennouri,Imene Ammar,Bassem Khemakhem,Hamadi Attia 한국식품영양과학회 2014 Journal of medicinal food Vol.17 No.8

Opuntia ficus-indica f. inermis (cactus pear) flowers have wide application in folk medicine. However, there are few reports focusing on their biological activity and were no reports on their chemical composition. The nutrient composition and hexane extracts of Opuntia flowers at 4 flowering stages and their antibacterial and antifungal activities were investigated. The chemical composition showed considerable amounts of fiber, protein, and minerals. Potassium (K) was the predominant mineral followed by calcium (Ca), magnesium (Mg), sodium (Na), iron (Fe), and zinc (Zn). The main compounds in the various hexane extracts were 9.12-octadecadienoic acid (29–44%) and hexadecanoic acid (8.6–32%). The antibacterial activity tests showed that O. inermis hexane extracts have high effectiveness against Escherichia coli and Staphylococcus aureus, making this botanical source a potential contender as a food preservative or food control additive.

Fracture toughness of chemical treated carbon nanotubes reinforced basalt/epoxy composites

( Seong-ock Lee ),( Soo-jin Park ) 한국공업화학회 2015 한국공업화학회 연구논문 초록집 Vol.2015 No.1

In this study, we analyzed the effect of chemical treatment of carbon nanotubes (CNTs) on fracture toughness of basalt fibers/epoxy composites. The surface properties of the CNTs were determined by FT-IR, XPS, and acid-base values. The mechanical properties of the composites were assessed by critical stress intensity factor (KIC), fracture energy (GIC), and impact strength. The chemical treatments led to a significant change of surface characteristics of the CNTs and mechanical properties of the composites.

식물조직단백의 물리적 특성에 영향을 미치는 화학적 성분

정휘원,최현우,김현석 한국산업식품공학회 2020 산업 식품공학 Vol.24 No.4

The objective of this study was to determine chemical compositions affecting the physical and thermal properties of the textured vegetable protein (TVP). The 14 commercial TVPs were pulverized, followed by analyzing their morphology, chemical composition, water absorption index (WAI) and water solubility index (WSI) (for the pulverized and original TVPs), solubility, swelling power, melting property, and hardness. All TVPs showed the rough surface with irregular cracks and pores and the porous structure with varied pore sizes. WAI was positively correlated to moisture and crude protein contents and negatively correlated to the total carbohydrate content. WSI and solubility were directly and reversely influenced by the crude ash and total carbohydrate contents and the crude protein and total starch contents, respectively. The swelling power and melting temperature of TVPs did not significantly affect chemical compositions. Melting enthalpies increased with crude ash content, while decreased with the total starch content. The hardness of the rehydrated TVPs was enhanced with their crude ash and total carbohydrate contents, whereas reduced with their crude protein and total starch contents. Overall, the yield and texture of the rehydrated TVP could be modulated with the crude protein and ash contents of TVP.

화학침착법과 고분자함침 열분해법의 복합공정으로 제조한 SiC_f/SiC 복합체의 제조 공정에 따른 파괴거동

박지연,한장원,김대종,김원주,이세훈,Park, Ji Yeon,Han, Jangwon,Kim, Daejong,Kim, Weon-Ju,Lee, Sea Hoon 한국세라믹학회 2014 한국세라믹학회지 Vol.51 No.5

$SiC_f$/SiC composites were prepared using the hybrid process of chemical vapor infiltration (CVI) and polymer impregnation and pyrolysis (PIP). Before the application of PIP, partially matrix-filled preform composites with different densities were fabricated by control of chemical vapor infiltration time and temperature. The changes of the final density of the $SiC_f$/SiC composites had a tendency similar to that of preform composites partially filled by CVI. Composites with lower density after the CVI process had a larger increment of density during the PIP process. Three types of microstructures were observed on the fractured surface of the composite: 1) well pulled-out fibers and lower density, 2) slightly pulled-out fibers and higher density, and 3) only bulk SiC. The different fractions and distributions of the microstructures could have an effect on the mechanical properties of the composites. In this study, $SiC_f$/SiC composites prepared using a hybrid process of CVI and PIP had density values in the range of $1.05{\sim}1.44g/cm^3$, tensile strength values in the range of 76.4 ~ 130.7 MPa, and fracture toughness values in the range of $11.2{\sim}13.5MPa{\cdot}m^{1/2}$.