• Journal of Hydrogen and New Energy
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• v.23 no.5
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• pp.455-460
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• 2012

This work describes the hydriding chemical vapor synthesis (HCVS) of the $MgH_2$ in a hydrogen atmosphere and the product's hydriding-dehydridng properties. Mg powder was used as a starting material to synthesize $MgH_2$ and uniformly heated to a temperature of $600^{\circ}C$ for Mg vaporization. The effects of hydrogen pressure on the morphology and the composition of HCVS-$MgH_2$ were examined by using X-ray diffraction (XRD) and scanning electron microscopy (SEM). It is clearly seen that after the HCVS process, the particle size of synthesized $MgH_2$ was drastically reduced to the submicron or micrometer-scale and these showed different shapes (needle-like nanofibers and angulated plate) depending on the hydrogen pressure. It was found that after the HCVS process, the $H_2$ desorption temperature of HCVS-$MgH_2$ decreased from 380 to $410^{\circ}C$, and the minimum hydrogen desorption tempreature of HCVS-$MgH_2$ powder with needle-like shape can be obtained. In addition, the enhanced hydrogen storage performance for needle-like $MgH_2$ was achieved during subsequent hydriding-dehydriding cycles.

• Journal of the Korean Society of Food Science and Nutrition
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• v.16 no.1
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• pp.18-21
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• 1987

Influence of magnesium and calcium on the serum cholesterol concentration in rabbit blood serum was studied. The subjects were fed with the basal diet and magnesium, calcium and Korea Ginseng. The results obtained are summarized as follows: The subjects body weight fed a basal diet, magnesium, calcium and ginseng powder added did not increased, but the weight of liver was increased. Total cholesterol level of the subject fed ginseng powder 4mg. added diet group showed the lowest concentration. The subjects fed with a basal diet and magnesium/calcium(1:2) added diet showed the lower than anyother group. In case of free cholesterol and cholesterol ester, the subject fed with ginseng powder tap. magnesium/calcium(1:2) added diet showed the lowest concentration. The subjects of the lowest concentration of total cholesterol showed the lowest concentration of low density lipoprotein(LDL) and high density lipoprotein(HDL)/total cholesterol ratio was the higher level than any other group. In case of triglyceride and phospholipid, the subject fed with ginseng powder showed the triglyceride concentration gradually do creased, but phospholipid level was increased positively. In case of electrolytes, sodium and potassium of the subject fed with magnesium, calcium and ginseng powder 4mg added diet showed 120mEq/l 1 and 6.8mEq/l, respectively.

• Food Science and Preservation
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• v.21 no.3
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• pp.388-395
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• 2014

Six types of mixed cereals powder were prepared using different mixing ratios of barley, proso millet, sorghum, and adlay, and their nutritional components and functionalities were analyzed. The mixed cereals powders contained high levels of crude protein. The free amino acid and mineral contents of Sample E were the highest among all the samples. Fructose, glucose, sucrose, and maltose were detected as the four major free sugars in all the mixed cereals powders, and Sample D had the highest amount of reducing sugar among all the samples. The total polyphenol and total flavonoid contents of Sample F were significantly higher than those of the other samples. Sample C showed the highest level of DPPH radical scavenging activity and reducing power. As for the ABTS radical scavenging activity, the $IC_{50}$ of Sample D was the lowest among all the samples, but did not significantly differ from that of Sample C. Therefore, we suggest 2:2:1:1 (in Sample D) as the best mixing ratio of barley, proso millet, sorghum, and adlay to produce a mixed cereals powder with excellent nutritional value and antioxidant activities.

• Journal of Food Hygiene and Safety
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• v.35 no.5
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• pp.489-494
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• 2020

A total of 101 samples of convenience baby food products were analyzed by microwave digestion and mineral nutrients (iron, zinc, calcium, magnesium) were determined by inductively coupled plasma optical emission spectroscopy (ICP-OES). By type, the samples included 44 rice porridges, 40 soft-boiled rices, 11 purees, and 6 powders. The mean values for iron (Fe) content were 0.05 to 0.45 mg/100 g (excepted powder type, mg/l0 g). This was equivalent to 22.35% for rice porridge, 10.55% for soft-boiled rice, 9.88% for puree and 2.74% for powder type compared to the KDRIs (Dietary Reference Intakes for Koreans), respectively. The mean values for zinc (Zn) was 0.06 to 0.28 mg/100 g (excepted powder type, mg/l0 g) and the KDRI ratio was the lowest at 5.94% in puree, with 27.76%, 28.95% and 10.91% in rice porridge, soft-boiled rice and powder type, respectively. Calcium (Ca) content relative to KDRIs was relatively low compared to other minerals, with 6.65% for rice porridge, 3.61% for soft-boiled rice, 6.24% for puree and 3.07% for powder type, respectively. The magnesium (Mg) content of baby food ranged from 13.4% to 39.0% compared to KDRIs, and was included in all baby food as a whole. For balanced nutritional mineral supply to infants, it is recommended that information on mineral sources and ingredients in convenience baby food be clearly provided to ensure proper growth and development.

• Journal of Life Science
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• v.20 no.11
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• pp.1718-1724
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• 2010

Bioactive and chemical properties of silkworm powder (SP) degradation by fruit extract containing the proteolytic enzymes of kiwifruit, papaya, pineapple and pear were investigated. Silkworm powder was incubated with extracts from each fruit at $60^{\circ}C$ for 24 hr. Protein content was slightly higher in the SP treated with fruit extract than that in the control SP. Major minerals were K, Ca, Mg, and Zn. Major fatty acids were linolenic acid, oleic acid, and palmitic acid. When total protein patterns were analyzed by SDS-polyacrylamide gel electrophoresis (PAGE), silkworm protein was strongly degraded by the treatment of fruit extract from pineapple, papaya, and pear, but little silkworm degradation was observed in kiwifruit extract treatment. Fibriolytic activity was only detected in the SP by the fruit extract treatments from papaya and pear. DPPH radical scavenging activity was slightly stronger in the SP treated with fruit extract than that in silkworm powder. However, all these samples exhibiteda relatively low activity compared with the butylated hydroxytoluene (BHT). These results may provide the basic data for understanding the biological activities and chemical characteristics of SP treated with fruit extract for development of functional foods.

• The Korean Journal of Food And Nutrition
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• v.20 no.1
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• pp.27-33
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• 2007

An investigation evaluating the preparation and physicochemical properties of Oddi Jelly(jelly using mulberry fruit powder) with various increments of sericultural products(0.5, 1, 1.5 and 2%) derived from mulberry fruit powder was performed. The effects of the different increments of mulberry fruit powder added to Oddi Jelly were assessed using physicochemical, sensory and texture analysis properties. The moisture and crude protein content of the Oddi Jelly were significantly higher than the control(p<0.05). Conversely, the crude fat content of the Oddi Jelly were significantly lower than the control(p<0.05). A positive trend was observed for both mineral content and dark color with increased mulberry fruit powder. Similarly, a positive relationship was observed for texture analysis, hardness, gumminess and chewiness of the Oddi Jelly with increasing levels of mulberry fruit powder(p<0.05). Color, taste, texture and overall preference of Oddi Jelly were significantly highest in the Oddi Jelly containing 2% mulberry fruit powder(p<0.05). Results suggest that the optimal amount of mulberry fruit powder added in the manufacturing of Oddi Jelly was 2% of the total weight.

• Korean Journal of Food Science and Technology
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• v.54 no.3
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• pp.251-256
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• 2022

This study was conducted to determine whether Diospyros lotus L. fruit could be used as a natural functional food ingredient and whether its use should be increased. D. lotus fruit powder was found to have high acidity in the immature IDL stage and significantly higher sugar content in the mature MDL stage. The levels of crude fat, selenium, and tannins decreased significantly from the IDL stage to the MDL stage in D. lotus fruit powder. However, the levels of magnesium and calcium were significantly greater in the MDL stage than in the IDL stage (p<0.05). The total phenol content was significantly higher in the IDL stage, but the DPPH radical scavenging activity significantly increased in the MDL stage (p<0.05). In conclusion, the fruits of D. lotus. have high nutritional quality in both the immature and mature growth stages. Thus, it is a good candidate for use as a functional food, and its use should be increased because of its high nutritional qualities.

• Journal of Life Science
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• v.19 no.10
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• pp.1468-1477
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• 2009

The comparative effects of the fibrinolytic, and tyrosinase inhibition activities and electrophoretical protein patterns with freeze-drying silkworm powder (FDSW), heating-drying silkworm powder (HDSW) and fermented silkworm powder by Bacillus subtilis or Lactobacillus hilgardii were investigated. When total protein patterns of FDSW, HDSW, both fermented SW, were analyzed by native- and SDS-polyacrylamide gel electrophoresis (PAGE), there were slightly varietal differences in electrophoretical protein patterns. Major minerals of FDSW and HDSW were K, Ca, Mg, and Zn. Major compositional amino acids of FDSW and HDSW were glycine, alanine, glutamic acid, aspartic acid, and serine. Major fatty acids of FDSW and HDSW were linolenic acid, oleic acid, and palmitic acid. Fibriolytic activity was the highest in the fermented FDSW by 5% B. subtilis among the various samples. Tyrosinase inhibition activity was higher in the water and 70% methanolic extract of FDSW than in HDSW. DPPH radical scavenging activity was slightly stronger in HDSW than in FDSW. In addition, DPPH radical scavenging activity was higher in FDSW or HDSW fermented by L. hilgardii than that fermented by B. subtilis, however, all samples exhibited a relatively low activity compared to the butylated hydroxytoluene (BHT). These results may provide the basic data to understand the biological activities of fermented SW.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.2
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• pp.475-481
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• 2013

Although the lightly burnt MgO at $850{\sim}1000^{\circ}C$ has expansibility, it does not lead to unsound concrete. The expansion of MgO could compensate for shrinkage of concrete for a long-term, because the hydration of MgO occurs at a slow pace. Recently, the study and application of mineral admixture such as fly ash and blast furnace slag have increased for the hydration heat reduction, durability improvement, and reducing $CO_2$ emission in the construction industry. Thus, it is necessary to research on the concrete that contains both a mineral admixture and MgO as an expansion agent. This study investigates fundamental properties of fly ash concrete with lightly burnt MgO through various experiments. The adiabatic temperature test results showed that the fly ash concrete with MgO of the 5% replacement ratio had the slower pace of the temperature rise and the lower final temperature than the fly ash concrete. The influences of MgO on long-term compressive strength varied depending on water-binder ratio, and the long-term length change test results indicated the expansion effects of the FA concrete containing MgO.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.167-167
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• 2013

최근에 산화물 형광체는 황화물 형광체에 비해 높은 화학적 안정성을 나타내기 때문에 백색 발광 다이오드, 전계방출 디스플레이와 플라즈마 디스플레이 패널에 그 응용성을 넓히고 있다. 마그네슘 니오베이트(magnesium niobate, MgNb2O6)는 우수한 유전 특성(상대 유전상수=18.4)을 나타내기 때문에 마이크로파 유전체로 응용 가능하며, 단일상 릴랙서 페라브스카이트(relaxor perovskite) Pb(Mg1/3Nb2/3)O3을 합성하기 위한 전구체 (precursor)로 널리 사용되고 있으며, 나이오븀산염 이온에서 다양한 색상을 방출하는 활성제 이온으로 효율적인 에너지 전달이 일어남으로써 Sm3+, Dy3+, Eu3+와 같은 희토류 이온의 좋은 모체 격자로 개발할 수 있다. 본 연구에서는 마그네슘 니오베이트 MgNb2O6 모체 결정에 다양한 활성제 이온, 즉 Eu3+, Sm3+, Dy3+, Tb3+를 선택적으로 주입하여 발광 효율이 높은 천연색 형광체를 합성하고자 한다. 특히, 모체 결정에 주입되는 활성제 이온 주위의 국소적인 환경이 반전 대칭에서 변형되는 척도를 조사하여 활성제의 주 발광 파장의 세기가 최대가 되는 최적의 조건을 결정하고자 한다. Mg1-1.5xNb2O6:REx3+ 형광체 분말 시료는 초기 물질 MgO, Nb2O5와 희토류 이온을 화학 반응식에 맞게 정밀 저울로 측량하여 플라스틱 용기에 ZrO2 볼과 함께 넣고, 소정의 에탄올을 채운 뒤 밀봉하고서, 300 rpm의 속도로 20시간 볼밀 (ball-mill) 작업을 수행하였다. 그 후, 체(sieve)로 ZrO2 볼을 걸러낸 다음에 혼합된 용액을 각 비커에 담아서 $40^{\circ}C$의 건조기에서 24시간 건조하였고, 건조된 시료를 막자 사발에 넣고 잘게 갈고 80 ${\mu}m$의 체로 걸러낸 후에, 알루미나 도가니에 활성제 이온별로 각각 담아, 전기로에 장입하여 매분당 $5^{\circ}C$의 비율로 온도를 상승시켜 $350^{\circ}C$에서 5시간 동안 하소 공정을 실시한 후에, 온도를 계속 일정한 율로 증가시켜 $1,200^{\circ}C$에서 5시간 동안 소성하여 합성하였다. 합성된 형광체 분말의 결정 구조는 $Cu-K{\alpha}$ 복사선(파장: 1.5406)을 사용하여 X-선회절장치로 측정하였으며, 형광체의 표면 형상은 전계형 주사전자현미경으로 관측하였다. 흡광와 발광스펙트럼은 제논 램프를 광원으로 갖는 형광 광도계를 사용하여 측정하였다. 모체 결정에 활성제 이온 Eu3+, Sm3+, Dy3+, Tb3+가 도핑된 형광체 분말은 각각 적색, 주황색, 황색, 녹색 발광이 관측되었다. 각 발광 스펙트럼과 결정 입자의 크기와 형상 사이의 상호 관계를 조사하였다. 실험 결과로부터, 각 형광체의 발광 파장은 활성제 이온의 종류 와 서로 밀접하게 관련되어 있으며, 형광체 시료 합성시 활성제 이온의 농도를 선택적으로 조절함으로써 발광의 세기를 제어할 수 있음을 확인하였다.