• Title/Summary/Keyword: 무기물 특성

Search Result 296, Processing Time 0.025 seconds

Quantum Dot-Sensitized Solar Cells Based on Mesoporous TiO2 Thin Films (메조포러스 이산화티타늄 박막 기반 양자점-감응 태양전지)

  • Lee, Hyo Joong
    • Journal of the Korean Electrochemical Society
    • /
    • v.18 no.1
    • /
    • pp.38-44
    • /
    • 2015
  • This review article summarizes the recent progress of quantum dot (QD)-sensitized solar cells based on mesoporous $TiO_2$ thin films. From the intrinsic characteristics of nanoscale inorganic QDs with various compositions, it was possible to construct a variety of 3rd-generation thin film solar cells by solution process. Depending on preparation methods, colloidal QD sensitizers are pre-prepared for later deposition onto the surface of $TiO_2$ or in-situ deposition of QDs from chemical bath is done for direct growth of QD sensitizers over substrates. Recently, colloidal QD sensitizers have shown an overall power conversion efficiency of ~7% by a very precise control of composition while a representative CdS/CdSe from chemical bath deposition have done ~5% with polysulfide electrolytes. In the near future, it is necessary to carry out systematic investigations for developing new hole-conducting materials and controlling interfaces within the cell, thus leading to an enhancement of both open-circuit voltage and fill factor while keeping the current high value of photocurrents from QDs towards more efficient and stable QD-sensitized solar cells.

Risk Assessment of Groundwater Used for Washing GAP-certified Agricultural Crops after Harvest (GAP 농산물의 수확 후 처리에 사용되는 지하수의 위해성평가)

  • Kim, Hwang-Yong;Paik, Min-Kyoung;Kim, Areumnuri;Lee, Dong Gyu;Jeong, Mihye;Kim, Won-Il;Oh, Jin-A;Kim, Se-Ri;Hong, Su-Myeong
    • Journal of Food Hygiene and Safety
    • /
    • v.34 no.6
    • /
    • pp.551-556
    • /
    • 2019
  • Recently, due to the fact that the mineral content in the wash water of the GAP-certified melon exceeds the GAP wash water standards, there are cases where the certification cannot be maintained. Therefore, agricultural industry demand requesting relaxation of the inorganic elements standard for water quality has been increasing, taking into account the consumption characteristics of Korean melon, which is eaten after removing the peel. This study was conducted to evaluate the human risks of four inorganic materials (fluorine, arsenic, iron and manganese) based on the water quality data of 142 samples of groundwater that was used for washing GAP-certified Korean melon in Seongju area from 2017 to 2019. As a result, the HQ of four minerals in Koreans who consumed groundwater used for washing GAP-certified Korean melons in the Seongju area was below 0.10 on average. In particular, in the case of iron and manganese which are esthetic influence substances, the average HQ was 0.00. The overexposure group showed 0.01, which was lower than the HQ (average 0.01, overexposure group 0.03) of the group that consumed Korean melon. Based on all the results, even if the groundwater of the Seongju area is used to wash GAP-certified Korean melon, the impact from these four inorganic materials, including iron and manganese, for Korean population consuming Korean melon will be minimal.

A Study on Physico-chemical Property and Composition of Velvet Antler and Byproducts in Elk. (Elk종의 녹용과 부산물의 이화학적 특성에 관한 연구)

  • 이길왕
    • Journal of Life Science
    • /
    • v.14 no.3
    • /
    • pp.496-500
    • /
    • 2004
  • This study has been performed for physico-chemical property and composition of sinew, testes, tail, blood and velvet antler in Elk. Amino acid contents in the sinew taurine, alanine, histidine, and lysine were high contained, histidine, glutamic acid, taurine, and lysine were high contained in testes, glutamic acid, lysine, alanine, glycine, and phenylalanine were high contained in tail, histidine, glycine, and lysine were high contained in blood, glutamic acid, lysine, taurine, alanine, and glycine were high contained in velvet antler. And, based on the amount of mineral, $K^{+}$, $Ca^{2+}$, and $P^{+}$ were 444.8, 166.6 and 242.9mg per 100g in sinew, respectively. $K^{+}$, $Ca^{2+}$ and $P^{+}$ were 294.4, 330.5, and 514.3 mg per 100g in testes, respectively, $K^{+}$, $Mg^{2+}$, and $P^{+}$ were 1420.6, 118.4, and 1105.2mg per 100 mg in tail, respectively. Fe3+,-K+, and P+ were 344.1, 1023.6 and 157.2 mg per 100 mg in blood, respectively and $K^{+}$, $Ca^{2+}$ and $P^{+}$ were 888.4, l1533.1 and 14722.0 in velvet antler, respectively. Finaly, difference were found in comparison of composition of free mwtal ion (N $a^{+}$, $K^{+}$, $Mg^{2+}$ and $Ca^2$) bwteen blood, tail, tests, sinew and velvet antler, and composition of free metal in blood higher than those othersd higher than those others.

Nutritional Properties and Biological Activities of Artemisia annua L. (개똥쑥의 영양적 특성 및 생리활성)

  • Ryu, Ji-Hyun;Kim, Ra-Jeong;Lee, Soo-Jung;Kim, In-Soo;Lee, Hyun-Ju;Sung, Nak-Ju
    • Journal of the Korean Society of Food Science and Nutrition
    • /
    • v.40 no.2
    • /
    • pp.163-170
    • /
    • 2011
  • The nutritional properties and biological activities of leaves and stems of Gaeddongssuk (Artemisia annua L.) were investigated. Contents of moisture, crude lipid and crude protein were significantly higher in the leaves, and then ash, crude fiber and mineral were significantly higher in the stems. Contents of total phenols and flavonoids of leaves were about 2 fold higher than those of stems. Antioxidant activity was significantly increased in a dose-dependent manner; also, water and ethanol extracts of leaves were stronger than those of stems. Especially, DPPH radical scavenging activity, reducing power and tyrosinase inhibition activity were significantly higher in leaves extracts than stems extracts of Gaeddongssuk. But, ${\alpha}$-glucosidase inhibition activity was higher in stem than its leaves extract. In MTT assay by human breast adenocarcinoma cell line MCF-7 and MDA-MB-231, ethanol extracts of leaves showed the highest anticancer activity; the rates of growth inhibition were 76.26% and 52.59% on MCF-7 and MDA-MB-231 cells, at the concentration of $250\;{\mu}g$/mL, respectively. In conclusion, biological activities of extracts from Gaeddongssuk were dependent on the fiber, phenolic and flavonoid content.

Ecological Characteristics of the Epiphytes on Seagrass - I. Variations of the Epiphytic Community and Biomass Related to the Host Plant ($Zostera$ $marina$ (eelgrass) (해초에 부착하는 부착생물 군집의 생태학적 특성 - I. 잘피 ($Zostera$ $marina$ L.)의 성장에 따른 부착생물의 군집 변화)

  • Chung, Mi-Hee;Youn, Seok-Hyun
    • Korean Journal of Environmental Biology
    • /
    • v.29 no.4
    • /
    • pp.362-372
    • /
    • 2011
  • The relationships among total epiphytes, algal epiphytes and eelgrass ($Zostera$ $marina$ L.) were studied at eelgrass medows from July, 1998 to July, 1999 in Yulim-ri, Yeosu, Korea. Epiphytic diatoms on eelgrass leaves were observed from July to December 1998. From the results of this study, we inferred the following three (3) conclusions : 1) As eelgrass grew older, biomass of epiphytes increased, according to relationships between the leaf length and area of eelgrass and biomass (DW, AFDW and Chl. $a$) of epiphytes. 2) According to the ratio of dry weight, ash-free dry weight and Chlorophyll of epiphytes, the algae with calcareous or siliceous skeletons, such as coralline algae or diatoms, were dominated in the epitphytic algae community. 3) The autotrophic index (AI) calculated from AFDW and Chl. $a$ of epiphytes varied from 151 to 375. However, the period of autotrophic community was shorter than heterotrophic community and the value of AI was high. From these results, we inferred that heterotrophic community, including detritus or microorganisms were dominated in the most of research period.

Changes in Physicochemical Characteristics of Green Barley according to Days after Heading (출수 후 일수에 따른 쌀보리 종실의 이화학적 특성 변화)

  • Ju, Jung-Il;Lee, Ka-Soon;Min, Hee-Il;Lee, Byung-Jin;Kwon, Byung-Gu;Gu, Ja-Hyeong;Oh, Man-Jin
    • KOREAN JOURNAL OF CROP SCIENCE
    • /
    • v.52 no.1
    • /
    • pp.36-44
    • /
    • 2007
  • In order to evaluate the utilization of immature green barley kernels as food processing material, these experiments were carried out to analyze free sugars, free amino acids, mineral contents and color of two naked barley varieties according to their heading dates. Contents such as moisture, protein, fat, ash, and free sugars were gradually decreased according to the days after heading of the nonwaxy naked barley 'Saessalbori' and waxy naked barley 'Hinchalssalbori', while crude fiber and starch were gradually increased. Contents like maltose and maltotriose in immature green kernels were high, but free amino acids showed a tendency to decrease, among which the alanine content was the highest. As barley matured, beta-glucan content, redness and yellowness increased, while lightness decreased. Considering chemical composition and color, the immature green cereals were produced through blanching the spikes harvested before the yellow ripe stage around $26{\sim}27$ days after heading. The optimum duration of harvest was very limited to produce green whole grains. The harvested green barley cereals is able to eat raw barley or cook it as food processing material.

Combustion Properties of Wood Treated by Combining Phosphorus-Nitrogen Compounds (인-질소 화합물 조합에 의해 처리된 목재의 연소성)

  • Jin, Eui;Chung, Yeong-Jin;Kim, Si-Kuk
    • Applied Chemistry for Engineering
    • /
    • v.27 no.1
    • /
    • pp.39-44
    • /
    • 2016
  • This study was to investigate the characteristics of combustion toxic gases of pinus rigida specimens treated with chemical additives such as pyrophosphoric acid (PP)/ammonuium ion ($NH_4{^+}$), methylenepiperazinomethyl-bis-phosphonic acid (PIPEABP) and $PIPEABP/NH_4{^+}$. Each pinus rigida plates was painted in three times with 15 wt% of each chemical additives in the aqueous solution. After drying these specimens at room temperature, the production of combustion gases and smoke was examined by the cone calorimeter (ISO 5660-1). As a result, the peak mass loss rate time (PMLR time) treated with chemicals was delayed upto 10.5~47.4% compared to that of using untreated specimen. In addition, the peak production of carbon monoxide ($CO\;_{peak}$) of 32.1~71.4% and total smoke release rate (TSRR) of 15.6~43.6% for test pieces treated with the chemical additive were higher than that of using the virgin plate. In particular, for the specimens treated with the chemical additive, the rate of smoke release (RSR) 29.4~41.5% was obtained higher than that of untreated plate except the specimen treated with $PP/4NH_4{^+}$. It can thus be concluded that the treatment using the chemical additive could partially increase the combustion-retardation properties of the species when compared to those of the virgin plate.

Physicochemical Characteristics and Antioxidant Activities of Fermented Garlic Husk (발효 마늘껍질의 이화학적 특성 및 항산화 활성)

  • Kim, Ra-Jeong;Kang, Min-Jung;Lee, Soo-Jung;Shin, Jung-Hye;Sung, Nak-Ju
    • Journal of the Korean Society of Food Science and Nutrition
    • /
    • v.39 no.12
    • /
    • pp.1731-1738
    • /
    • 2010
  • This study was carried out to evaluate the possibility for functional characteristics of garlic husk and its products fermented by Lactobacillus plantarum. Each water and 80% ethanol extracts made from garlic husk and its fermented products were tested for antioxidant activities. Total mineral content of fermented garlic husk was 2,056.23 mg/100 g and its content was 1.5 times higher than the unfermented sample. Total phenol contents were the highest in the ethanol extracts made from fermented garlic husk. Activities of electron donating, reducing power and NO radical scavenging in the ethanol extracts of fermented product were significantly higher than the unfermented sample. ABTS radical scavenging activity of fermented garlic husk was higher than the unfermented sample. Also, its activity was higher in the ethanol extracts than the water extracts. Nitrite scavenging activity of garlic husk was significantly different between fermented and not fermented sample. Because antioxidative effects of fermented garlic husk were elevated, these results recommended its utilization as a functional materials for animal feed.

Studies on the Nutritional Components and Physicochemical Characteristics of Various Flax(Linum usitatissimum) Seeds and Oils (아마인과 아마인유의 영양성분과 물리화학적 특성)

  • Nam, Jin-Sik
    • The Korean Journal of Food And Nutrition
    • /
    • v.23 no.4
    • /
    • pp.516-525
    • /
    • 2010
  • Flaxseed has recently gained attention as a functional food. In this paper, physicochemical analyses of flaxseed and its oil were performed. Crude fat content ranged from 37~43%, moisture 0.2~6.8%, carbohydrate 30~35%, crude protein 18~23%, and crude ash 3~4%. Flaxseed is also an important source of dietary fiber. The TDF(total dietary fiber) contents of the flaxseed samples were 28~31%, and the SDF(souble dietary fiber) content of roasted flaxseeds was higher than that of raw flaxseeds. The major minerals found in flaxseed were calcium, potassium, magnesium, and phosphate. The flaxseeds were rich in ${\gamma}$-tocopherol with 234.3 mg/kg in raw brown flaxseed and 134.1 mg/kg in raw gold flaxseed, respectively. Roasted flaxseeds showed slightly lower vitamin and amino acid contents than those of the raw samples. The iodine, saponification, and acid values of brown flaxseed oil were 204.1 g/100 g, 193.6 mg/g, and 1.59 mg/g, and for gold flaxseed oil were 203.0 g/100 g, 189.9 mg/g, and 2.35 mg/g, respectively. ${\alpha}$-Linolenic acid(ALA, C18:3n-3) was highly concentrated in the flaxseed oil, which constituted about 55.5~56.1% of total fatty acids. Thus, flaxseed oil is a good source of omega-3 fatty acids and beneficial for the heart. Flaxseed contains high levels of dietary fiber including lignans, as well as minerals and vitamins, which may have antioxidant actions and help protect against certain cancers.

Behavior Interpretation and Secondary Degradation of the Standing Sculptured Buddha at the Yongamsa Temple, Ogcheon, Korea (옥천 용암사 마애불의 거동특성 해석과 이차적 훼손)

  • Lee, Chan Hee;Chung, Youn Sam;Kim, Ji Young;Yi, Jeong Eun
    • Journal of Conservation Science
    • /
    • v.17 s.17
    • /
    • pp.83-94
    • /
    • 2005
  • Host rock or the standing sculptured Buddha in the Yongamsa temple is macular porphyritic biotite granite, which has gone through mechanical and chemical weathering. The rock around the Buddha statue is busily scattered with steep inclinations that are almost vertically discontinuous planes with the strikes of $N8^{\circ}E$. Especially the development of the joints that cross the major joints causes the structural instability of the rock. The rock of the Buddha statue is separated into several rock blocks because of many different discontinuity. Thus it is estimated that the bed rock has not only plane and toppling failure but also wedge failure in all the sides. Since the differential pressure is imposed on the body of the Buddha in the host rock, it is urgent to give a reinforce treatment of geotechnical engineering for the safe of its structural stability. Very contact area of joints have turned into soil, which promotes the growth of weeds and plant roots, then aggravates the mechanical weathering of the rock. Thus conservational treatments should also be considered to get rid of secondary contaminants and vegetation along the discontinuities and to prevent further damages.

  • PDF