• Title/Summary/Keyword: Low-density concentration

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Effect of Sea Tangle (Laminaria japonica) and Charcoal Supplementation as Alternatives to Antibiotics on Growth Performance and Meat Quality of Ducks

  • Islam, M.M.;Ahmed, S.T.;Kim, Y.J.;Mun, H.S.;Kim, Y.J.;Yang, C.J.
    • Asian-Australasian Journal of Animal Sciences
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    • v.27 no.2
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    • pp.217-224
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    • 2014
  • A total of 150 growing ducks were assigned to five dietary treatments to study the effect of sea tangle and charcoal (STC) supplementation on growth performance and meat characteristics in a completely randomized design. There were six replicates and five ducklings in each replication. The five dietary treatments were control, antibiotic, and 0.1%, 0.5%, and 1% STC supplemented diets. No significant differences were found on ADG, ADFI, and gain:feed among treatments in different weeks. The overall (0 to 3 weeks) ADFI decreased in antibiotic treatment (p<0.05) whereas the gain:feed increased significantly upon 1.0% STC supplementation compared to control (p<0.05). No significant variation was found in meat chemical composition except crude fat content which was high in 1.0% STC dietary group (p<0.05). Meat cholesterol was reduced in 0.1% STC group (p<0.05) compared to other dose levels while serum cholesterol was unaffected. High density lipoprotein (HDL) content was high in 1.0% STC (p<0.05) and low density lipoprotein (LDL) was low in 0.1% and 1.0% STC dietary groups (p = 0.06). No significant effect was found on the thiobarbituric acid reactive substances (TBARS) of fresh meat, whereas the TBARS value of meat preserved for 1 week was reduced significantly in STC dietary groups (p<0.05). The 0.1% STC dietary group showed an increased myristic acid (p = 0.07) content whereas, the content of eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids increased in STC supplementation than antibiotic group (p<0.05). An increased concentration of omega-3 fatty acids and a reduced ratio of n-6/n-3 PUFA ratio was found upon 1.0% STC supplementation compared to antibiotic dietary group (p<0.05). Therefore, 1.0% STC dietary supplementation can be used as alternatives to antibiotics in duck production.

Modeling the Chemical Kinetics of Atmospheric Plasma

  • Kim, Ho-Yeong;Lee, Hyeon-U;Kim, Gyu-Cheon;Lee, Jae-Gu
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.08a
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    • pp.270-270
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    • 2012
  • Low temperature atmospheric pressure plasmas (APPs) have been known to be effective for living cell inactivation in the water [1]. Many earlier research found that pH level of the solution was changed from neutral to acidic after plasma treatment. The importance of the effect of acidity of the solution for cell treatments has already been reported by many experiments. In addition, several studies have demonstrated that the addition of a small amount of oxygen to pure helium results in higher sterilization efficiency of APPs [2]. However, it is not clear yet which species are key factors for the cell treatment. To find key factors, we used GMoo simulation. We elucidate the processes through which pH level in the solution is changed from neutral to acidic after plasma exposure and key components with pH and air variation with using GMoo simulation. First, pH level in a liquid solution is changed by He+ and He(21S) radicals. Second, O3 density decreases as pH level in the solution decreases and air concentration decreases. It can be a method of removing O3 that cause chest pain and damage lung tissue when the density is very high. H2O2, HO2 and NO radicals are found to be key factors for cell inactivation in the solution with pH and air variation.

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Studies on the Chemical Resistance of Phytopathogenic Bacteria I. Chemical Resistance of the Rice Bacterial Leaf Blight Pathogen, Xanthomonas oryzae (Uyeda et Ishiyama) Dowson, to Agrepto (식물병원성 세균의 약제저항성에 관한 연구 1. 벼흰빛잎마름병균의 Agrepto에 대한 저항성)

  • Shim Jai Wook
    • Korean journal of applied entomology
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    • v.14 no.1 s.22
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    • pp.7-12
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    • 1975
  • The experiments were conducted to examine the formation of chemical resistance of Xanthomonas oryze, the causal organism of rice bacterial leaf blight, to Agrepto in the succeeding geerations. The measurements of the bacterial growth were determined with the optical density as indirect method, and the results obtained were summarized as follows. 1. The Agrepto was effective in hindering the bacterial growth in the treatment of first generation, which was added in the broth even as low concentration as 30ppm. 2. when the successive four generations were treated with same concentrations, the bacterial growth increased conspicuously with succeeding generations and this phenomenon showed remarkable in the plots treated with 30ppm than in that of 10ppm. 3. When selections were repeated at treatment of 20 ppm, increasing the concentrations of the treatment in successive generations, the resistance increased with succeeding generations. 4. There was a tendency to acquire the higher rate of resistance in the progenies which selected from the treated plot of higher concentrations in previous generation than that of low concentrations.

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Growth and solute pattern of Suaeda maritima and Suaeda asparagoides in an abandoned salt field

  • Choi, Sung-Chul;Lim, Sung-Hwan;Kim, Sang-Hun;Choi, Deok-Gyun;Kim, Jong-Guk;Choo, Yeon-Sik
    • Journal of Ecology and Environment
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    • v.35 no.4
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    • pp.351-358
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    • 2012
  • To investigate the environmental adaptation and ecophysiological characteristics of Suaeda maritima and S. asparagoides under saline conditions, plant growth and density were analyzed according to environmental changes of habitats. The total ion content of soil decreased with time, which was caused by the predominance of exchangeable $Na^+$ and $Cl^-$ in the upper layers. The population of S. maritima was more densely distributed in the region with higher ion contents of $Cl^-$, $Mg^{2+}$, $K^+$ and $Na^+$ than the population of S. asparagoides. Both species were showed a decreased population density according to increases in plant growth. Under the conditions of a salt field, S. maritima and S. asparagoides contained high inorganic ions to maintain low water potential, but low water soluble carbohydrate contents. In the case of free amino acid, S. maritima showed an especially high proline content, and contained rather large amounts of free amino acids, whereas S. asparagoides did not. Both species showed high inorganic ion contents in the leaves, which might be a mechanism of avoiding the ionic toxicity by diluting the accumulated ionic concentration with a high ratio of water content to dry weight. This result suggests that S. maritima seems to adapt to saline conditions by accumulating proline in addition to inorganic ions. S. asparagoides seems to adapt by osmoregulation processes, using inorganic ions rather than free amino acids.

Preventive Effects of GLEDITSIAE SPINA Ethanol Extracts and its Fraction on Oxidative Stress and Human LDL Oxidation (GLEDITSIAE SPINA 에탄올 추출물 및 분획물이 산화적 스트레스와 human LDL 산화억제에 미치는 영향)

  • Kim, Hyuck;Lee, Min-Ja;Lee, Hye-Sook;Jung, Hyun-Jung;Choi, Sung-Kyu;Lee, Chang-Sub;Park, Won-Hwan
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.23 no.3
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    • pp.631-638
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    • 2009
  • GLEDITSIAE SPINA (GS) has been used as folk remedies traditionally for treatment of antiphlogistic and antifebrile agents. An ethanol extract and its fraction of GS were assessed to determine the mechanism of its antioxidant activity. Also, inhibitory effect of extract from GS and its fraction measuring the inhibitory effect on $Cu^{2+}$-induced human low-density lipoprotein (LDL) oxidation. GS ethanol extract and its fraction exhibited a concentration-dependent reactive oxygen species (ROS) and reactive nitrogen species (RNS) scavenging activities, including trolox equivalent antioxidant capacity (TEAC), OPPH radical, superoxide anion, hydroxyl radicals, peroxynitrite and nitric oxide, using different assay systems. Furthermore, the GS ethanol extract and its fraction showed dose-dependent protection of LDL oxidation induced by $CuSO_4$. In addition, the GS ethanol extract and its fraction were characterized as containing a high amount of total phenolics. These results suggest that GS ethanol extract and its fraction might be helpful for preventing oxidative stress and protecting LDL oxidation.

Technology of selective absorber coatings on solar collectors using black chromium+3 sulfate acid on substrates (흑색 황산3가크롬을 이용한 태양열 흡열판 선택흡수막 도금기술)

  • Ohm, Tae-In;Yeo, Woon-Tack;Kim, Dong-Chan
    • Journal of the Korean Solar Energy Society
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    • v.33 no.3
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    • pp.27-35
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    • 2013
  • One of the most important factors that have a large influence on performance of the solar water heater system is performance of the solar collector, more detailedly, coating technology on the surface of the solar collector, which can provide high solar absorptance and low emittance. The core of the coating technology is to coat solar selective surfaces. In this study, various performance experiments are carried out using $Cr_2(SO_4)_3{\cdot}15H_2O$ coating technology. Here, IGBT(Insulated Gate Bipolar Transistor) of 5000A-15V was used as the surface processing rectifier which can stably output power and also can control voltage and current. The plating solution mainly contains black chrome$^{+3}$ concentration, H-y Conductivity, N-u Complex, NF Additive and NC-2 Wetter. Before applying the black chrome coating on the copper plate, optimal conditions are provided by using various preprocessing methods such as removal of fat, activation, electrolytic polishing, nickel strike, copper sulfate plating and bright neckel plating, and then the automatic continuous coating experiment are performed according to plating time and cathode current density. In the experiment, after the removal of fat, chemical polishing, nickel strike and activation processes as the preprocessing methods, the black chrome coating was performed in a plate solution temperature of $28^{\circ}C$ and a cathode current density of $18A/cm^2$ for 90 seconds. The thickness of chrome and nickel on the coated plate is $0.389{\mu}m$, $159{\mu}m$ respectively. As a result of the coating experiment, it showed the most excellent performance having a high solar absorptance of 98% and a low emittance of $5{\pm}1%$ when the black chrome surface had a thickness of $0.398{\mu}m$.

Effects of Pharbitidis Semen on 3T3-L1 Cells and Obesity-induced Rats (흑축이 3T3-L1 세포와 비만 유도 흰 쥐에 미치는 영향)

  • Shin, Man-ho;Lee, Da-eun;Jang, Hye-yeon;Lee, Young-su
    • The Journal of Internal Korean Medicine
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    • v.40 no.3
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    • pp.356-368
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    • 2019
  • Objectives: This study was designed to evaluate the efficacy of Pharbitidis Semen (PS) on obesity using 3T3-L1 cells and high-fat-diet rats. Methods: After the administration of PS at a concentration of 0.125, 0.25, and 0.50 mg/ml in 3T3-L1 cells, the degree of differentiation of adipocytes was measured by Oil Red O staining. The experimental animals were divided into five groups in vivo. Normal group: diet-fed normal group (Normal), Control group (Control): high-fat-diet (HFD)-fed, Positive control group (PC): HFD+Contrave 200 mg/kg, PS_Low group: HFD+PS 250 mg/kg group, PS_High group: HFD+PS 500 mg/kg. Results: The total cholesterol, low density lipoprotein-cholesterol (LDL-cholesterol), and triglycerides (TG) content of the PS medication groups were significantly lower than those of the control group. In addition, high density lipoprotein cholesterol (HDL-cholesterol) tended to increase, and free fatty acid, total lipid, and phospholipid tended to decrease, but the decrease was not statistically significant. The administration of PS inhibited the differentiation of 3T3-L1 adipocytes, and a statistically significant difference was found in the group administered with 0.125 mg/ml. The mRNA expression of $PPAR-{\gamma}$ and leptin, which are involved in the differentiation of adipocytes, was observed using reverse transcription polymerase chain reaction (RT-PCR). The expressions of $PPAR-{\gamma}$ and leptin significantly decreased in comparison with the control and the positive control.

Combustion-Retardation Properties of Low Density Polyethylene and Ethylene Vinyl Acetate Mixtures with Magnesium Hydroxide (수산화마그네슘이 첨가된 저밀도 폴리에틸렌과 에틸렌 비닐 아세테이트 혼합물의 난연성)

  • Chung, Yeong-Jin;Lim, Hyung Mi;Jin, Eui;Oh, JungKyoo
    • Applied Chemistry for Engineering
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    • v.22 no.4
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    • pp.439-443
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    • 2011
  • It was performed to test the combustive properties of low density polyethylene and ethylene vinyl acetate (LDPE-EVA) mixture by the addition of magnesium hydroxide. Flame retardant of natural magnesium hydroxide was added to the mixture of LDPE-EVA in 40 to 80 wt% concentration. The composite was compounded to prepare specimen for combustive analysis by cone calorimeter (ISO 5660-1). Comparing with virgin LDPE-EVA, the specimens including the magnesium hydroxide had lower combustive properties. It is supposed that the combustion-retardation properties in the composites improved due to the endothermic decomposition of magnesium hydroxide. The specimens with magnesium hydroxide showed both the lower peak heat release rate (PHRR) and lower effective heat of combustion (EHC) than those of virgin polymer. As the magnesium hydroxide content increases, time to ignition increased and the peak heat release rate decreased.

Properties of Foamed Concrete According to Types and Concentrations of Foam Agent (기포제 종류 및 희석 농도에 따른 기포 콘크리트의 특성)

  • Kim, Jin-Man;Jeong, Ji-Yong;Hwang, Eui-Hwan;Shin, Sang-Chul
    • Journal of the Korea Concrete Institute
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    • v.24 no.1
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    • pp.61-70
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    • 2012
  • Recently, the government has been working feverously to save energy and reduce greenhouse gas emission by enacting Basic Act on Low Carbon Green Growth at the national level. Improving the insulation performance of building exterior and insulator can reduce the energy in the building sector. This study is about developing light-weight foamed concrete insulation panel that can be applied to buildings to save energy and to find the optimal condition for the development of insulation materials that can save energy by enhancing its physical, kinetic and thermal characteristics. Various experimental factors and conditions were considered in the study such as foam agent types (AES=Alcohol Ethoxy Sulfate, AOS=Alpha-Olefin Sulfonate, VS=Vegetable Soap, FP=Fe-Protein), foam agent dilution concentration (1, 3, 5%), and foam percentage (30, 50, 70%). Experiment results indicated that the surface tension of aqueous solution including foam agent, was lower when AOS was used over other foam agents. FP produced relatively stable foams in 3% or more, which produced unstable foams containing high water content and low surface tension when diluted at low concentration. Depending on foam agent types, compressive strength and thermal conductivity were similar at low density range but showed some differences at high concentration range. In addition, when concentrations of foam agent and foaming ratio increased, pore size increased and open pores are formed. In all types of foam agent, thermal conductivity were excellent, satisfying KS standards. The most outstanding performance for insulation panel was obtained when FP 3% was used.

Microbiological Characteristics of Gamma Irradiated and Low-Salted Fermented Squid (감마선 조사된 저염 오징어젓갈 발효의 미생물균총 특성)

  • Kim, Dong-Ho;Kim, Jae-Hun;Yook, Hong-Sun;Ahn, Hyun-Joo;Kim, Jung-Ok;Sohn, Cheon-Bae;Byun, Myung-Woo
    • Korean Journal of Food Science and Technology
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    • v.31 no.6
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    • pp.1619-1627
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    • 1999
  • Microbiological characteristics of gamma irradiated low salt squid Jeot-gal were examined. Following the fermentation periods, total bacterial cell, Lactobacillus spp., Staphylococcus spp., Streptococcus spp., Pseudomonas spp. and yeast cell number were counted on their selective media and some acid forming bacteria and Pseudomonas spp. were identified. As the gamma irradiation dose increased, the microbial density of early fermentation phase was reduced and the growth rate was delayed. The repression effects on microbiological growth by gamma irradiation were to be higher as salt concentration increased. Adequate conditions of salt concentration and gamma irradiation for low-salt squid Jeot-gal preparation were 10% and 10 kGy, respectively. Lactobacillus sp. 2, Micrococcus varians and Streptococcus sp. I were isolated from 5% salt containing squid Jeot-gal, and Micrococcus morrhuae was from 20% only while Lactobacillus plantarum and Lactobacillus brevis were widespread. Lactobacillus brevis, Pediococcus halophilus and Pseudomonas diminuta were sensitive and Lactobacillus plantarum, Micrococcus morrhuae and Pseudomonas sp. 3 were resistant to gamma irradiation. The diversity of microflora decreased as salt concentration decreased and gamma irradiation dose increased.

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