• 한국동물위생학회지
• /
• 제23권1호
• /
• pp.45-59
• /
• 2000

The present study was conducted to investigate the epidemiological properties of salmonellosis of poultry farms in Kyongbuk province during the relied from November 1998 to November 1999 And antibiotic susceptibility and biochemical characteristics of 120 Salmonella cultures isolated from chicken samples were also investigated. The results obtained through this study were summarized as follows, 1. Among 667,200 chickens of 31 flocks in 17 layer farms and 9 broiler farms, 61,350 chickens of 31 flocks were died with salmonellosis. The death rate of 25 farms varied from 0.1% to 75.0%, and the average death rate was 9.2%. 2. According to etiological agents, fowl typhoid was shown the most predominant outbreak among the salmonellosis during a year, which accounted for 8R.0%(22/25) of the total case 3. The serotypes of 120 Salmonella isolates were identified as 7 strains(5.8%) of S pullorum, 10 strains(8.4%) of S typhimurium and 103 strains(85.8%) of S gallinarum. 4. Most outbreak of fowl typhoid were prevalent on the layer chicken farms(77.1%), and the summer season(45.5%) also appeared the most hazardous season during the year. 5. It seemed that the Hyline breed(70.6%) was the most susceptible among the layer chicken breeds, and followed by Isabrown(23.5%), Tetra(5.9%) in order. 6. In layers, 76.4% of fowl typhoid occurred commonly from 14 to 40 weeks including the early laying peroid, but in broiler farms, all cases was outbreak within first second weeks. 7 All the strains of S pullorum were resistant to lincomycin(Lm), penicillin(Pm), and steptomycin(Sm), but sensitive to amikacin(Ak), ampicillin(Am), cephalothin(Ce), ciprofloxacin (CiP), chloramphenicol(Cm), colistin(Co), enrofloxacin(Enr), furazolidone(Fu), gentamicin(Gm), kanamycin(Km), neomycin(Nm), polymyxin(Po), and teracycline(Tc). All the strains of S typhimurium were resistant to Lm(100%), Pm(100%), Po(90%), and Sm(90%), but were sensitive to Ak, Am, Ce, CiP, Cm, Co, Enr, Fu, Gm, Km, Nm, and Tc. 8. Minimum inhibitory concentration(MIC) of 103 strains of S gallinarum were also evaluated and their patterns were much more variable than others. All the strains of S gallinarum were sensitive to Ak, Am, Ce, Cip, Cm, Enr, Fu, Km, and Nm, but resistant to Lm(100%), and Sm(100%), 99(96.1%) to Co, 83(80.6%) to Pm, and 83(80.6%) to Po, 55(53.4%) to Gm, and 33(32.0%) to Tc. 9. The multiple drug resistance patterns of 120 Salmonella strains were CoLmPmPo Sm pattern(34.2%), CoGmLmPmPoSmTc(20.8%), CoGmLmPmPoSm(13.3%), CoGmLmSm(7.5%), LmPmSm(7.5%), LmPm(6.7%), CoLmSmTc(3.3%),, CoGmLmSmTc(1.7%), GmLmSmTc(1.7%), CoGmLmPoSm(0.1%), LmPmPo(0.1%), CoLm Sm(0.1%), and LmSm(0.1%), in order.

• 한국토양비료학회지
• /
• 제45권3호
• /
• pp.428-434
• /
• 2012

A fungal strain, capable of solubilizing insoluble phosphate under diverse temperature, pH and salt conditions was isolated from Waste Mushroom bed of Agaricus bisporus in South Korea. Based on 18S rRNA analysis, the strain was identified as Aspergillus awamori bxq33110. The strain showed maximum phosphate solubilization in AYG medium (525 ${\mu}g\;mL^{-1}$) followed by NBRIP medium (515 ${\mu}g\;mL^{-1}$). The strain solubilized $Ca_3(PO_4)_2$ to a greater extent and rock phosphate and $FePO_4$ to a certain extent. However $AlPO_4$ solubilizing ability of the strain was found to be very low. Glucose at the rate of 2% ($561{\mu}g\;mL^{-1}$) was found be the best carbon source for Aspergillus awamori bxq33110 to solubilize maximum amount of phosphate. However, no significant difference ($P{\leq}0.05$) in phosphorus solubilization was found between 1% and 2% glucose concentrations. $(NH_4)_2SO_4$ was the best nitrogen source for Aspergillus awamori bxq33110 followed by $NH_4Cl$ and $NH_4NO_3$. At pH 7, temperature $30^{\circ}C$ and 5% salt concentration (674 ${\mu}g\;mL^{-1}$) were found to be the optimal conditions for insoluble phosphate solubilization. However, strain Aspergillus awamori bxq33110 was shown to have the ability to solublize phosphate under different stress conditions at $30-40^{\circ}C$ temperature, pH 7-10 and 0-10% salt concentrations indicating it's potential to be used as bio-inoculants in different environmental conditions.

• The Korean Journal of Ceramics
• /
• 제4권2호
• /
• pp.68-71
• /
• 1998

The effect of Mn and Nb additions on the electrical properties of BaTiO$_3$ has been studied by means of equilibrium electrical conductivity as a function of temperature, oxygen partial pressure(Po$_2$) and composition. If the manganese ion is added to the normal Ti site, i.e. BaTi$_{1-x}Mn_xO_{\delta-6}$, the equilibrium conductivity shows strong evidence of acceptor-doped behavior. The conductivity minimum, corresponding to the transition from oxygen excess, p-type behavior to oxygen deficient, n-type behavior with decreasing Po$_2$, is displaced to lower Po$_2$ and is broadened and flattened. The partial replacement of Mn ion with Nb decreases the acceptor-doped effect and the total replacement exhibits a typical donor-doped behavior. It was confirmed that unlike undoped or other acceptor-doped behavior. It was confirmed that unlike undoped or other acceptor-doped samples, for the p-type region, the electrical conductivity follows the 1/6th power dependence of oxygen partial pressure.

• 한국환경과학회지
• /
• 제21권3호
• /
• pp.363-368
• /
• 2012

The influence of plasma discharge on the nutrient components ($NO_3$-N, $NH_4$-N, $PO_4$-P, K, Ca, and Mg) and water quality [pH, ORP (oxidation-reduction potential) and electric conductivity] of hydroponic water were investigated. It was observed that the $NH_4$-N, $PO_4$-P, K, Ca, and Mg were kept at the constant concentrations for plasma discharging of 90 min. On the other hand, $NO_3$-N concentration was increased with proceeding of the plasma discharge. The increase of $NO_3$-N concentration was considered with the fact that nitric acid was created from nitrogen among supplying air for the insulation of inside of dielectric barrier. ORP and electric conductivity was increased with plasma discharging time. However, pH was decrease with what because of the generation of the nitric acid. When adjusting the hydroponic ingredients, pH and conductivity must to be considered because of the change of pH and conductivitiy with the discharging.

• 구강회복응용과학지
• /
• 제30권2호
• /
• pp.112-120
• /
• 2014

목적: 이 논문의 목적은 열가압법을 이용한 도재의 축성이 금속과 어떠한 결합력을 나타내는지 알아보는 것이다. 연구 재료 및 방법: 90개의 비귀금속 시편($4{\times}4{\times}8mm$)을 제작하여 세 개의 군으로 나누었다. 모든 시편은 군에 따라 2종류의 다른 방법으로 포세린 축성($4{\times}4{\times}3mm$)하였다: Group I : $Inspiration^{(R)}$, Group II : Ivoclar, IPS $Inline^{(R)}PoM$, Group III: GC Initial IQ-One $Body^{(R)}PoM$. 각 군의 시편의 반은 열순환시켰다. 모든 시편의 전단 결합 강도는 Instron universal testing machine을 이용하여 측정하였다. 통계학적 분석을 위해, 2-way ANOVA가 사용되었다. 결과: 열순환을 하지 않은 시편의 전단결합강도는 모든 실험군에서 유사한 값으로 나타나 통계적 유의성이 없었다(P > 0.05). 각 실험군에서 열순환 처리 한 시편에서는 전단결합강도의 감소가 나타났으나 통계적 유의성은 없었다(P > 0.05). 열순환 처리한 시편의 실험군간 전단결합강도 비교에서 실험 III군에서 높게 나타났으나 유의한 차이는 없었다(P > 0.05). 결론: 전단결합력의 관점에서 보았을 때 열가압성형 도재는 임상적으로 유의한 것으로 사료된다.

• 한국식품과학회지
• /
• 제21권5호
• /
• pp.619-623
• /
• 1989

토양으로부터 분리 동정된 Pseudomonas mendocina의 다당류 생산조건을 검토하였다. 최적 배지조성은 Sucrose 23.75g/L, $(NH_4)_2SO_4$ 1.57g/L, Yeast extract 0.5g/L, $KH_2PO_4\;2.0g/L,\;MgSO_4.\;7H_2O\;1.0g/L,\;CaCO_3$ 2.5g/L이었으며, 최적 pH 및 배양온도는 6.5 및 $30^{\circ}C$이었다. 이 조건에서 다당류의 생산량은 5.98g/L이며 대당 수율은 25.18%, 비생산속도는 32.83mg/g-cell/h이었다.

• 한국토양비료학회지
• /
• 제49권5호
• /
• pp.429-433
• /
• 2016

Adsorption and precipitation of cadmium (Cd) could be dependent on rate of P addition and Cd level in soil. Therefore, the objective of this study was to examine how addition rate of P affect mechanisms of Cd immobilization such as adsorption and precipitation in different levels of Cd in soil. Arable soils were spiked with inorganic Cd ($CdCl_2$) to give a total Cd concentration of 10, 100, and $1,000mg\;Cd\;kg^{-1}$. Monopotassium phosphate ($KH_2PO_4$, MPP) was selected as phosphate material and mixed with the pretreated arable soil at the rates of 0, 800, 1,600 and $3,200mg\;P\;kg^{-1}$. The mixture soils were incubated at $25^{\circ}C$ for 8 weeks in dark condition. Soil pH decreased with increasing MPP addition rate in all levels of Cd but negative charge of soil increased, thereby reducing 1 M $NH_4OAc$ extractable Cd. Soil solutions were undersaturated with respect to $CdCO_3$ and $Cd_3(PO_4)_2$ with all P addition rate in soil with low Cd level (${\leq}100mg\;Cd\;kg^{-1}$) but supersaturated in soil with high Cd level ($1,000mg\;Cd\;kg^{-1}$). From the above results, Cd solubility was controlled by precipitation of Cd minerals such as $CdCO_3$ and $Cd_3(PO_4)_2$ in soil with high Cd level but by Cd adsorption induced by increase in negative charge of soil with low level of Cd.

• 한국재료학회지
• /
• 제29권9호
• /
• pp.519-524
• /
• 2019

Spherical $Li_3V_2(PO_4)_3$ (LVP) and carbon-coated LVP with a monoclinic phase for the cathode materials are synthesized by a hydrothermal method using $N_2H_4$ as the reducing agent and saccharose as the carbon source. The results show that single phase monoclinic LVP without impurity phases such as $LiV(P_2O_7)$, $Li(VO)(PO_4)$ and $Li_3(PO_4)$ can be obtained after calcination at $800^{\circ}C$ for 4 h. SEM and TEM images show that the particle sizes are $0.5{\sim}2{\mu}m$ and the thickness of the amorphous carbon layer is approximately 3~4 nm. CV curves for the test cell are recorded in the potential ranges of 3.0~4.3 V and 3.0~4.8 V at a scan rate of $0.01mV\;s^{-1}$ and at room temperature. At potentials between 3.0 and 4.8 V, the third $Li^+$ ions from the carbon-coated LVP can be completely extracted, at voltages close to 4.51 V. The carbon-coated LVP exhibits an initial specific discharge capacity of $118mAh\;g^{-1}$ in the voltage region of 3.0 to 4.3 V at a current rate of 0.2 C. The results indicate that the reducing agent and carbon source can affect the crystal structure and electrochemical properties of the cathode materials.

• Applied Biological Chemistry
• /
• 제43권2호
• /
• pp.124-129
• /
• 2000

농업유역에서 영양원소들은 시비 후 강우에 의해 지표 유출이 생기면 용해되거나 토사에 흡착된 상태로 하천에 유입되어 부영양화의 주요한 요인이 되고 있다. 농경지로부터의 영양염류 유실 정도를 평가하기 위해 경북 영천군 임고천 유역의 대표적 영농형태인 과수원 토양에 $14.3{\times}24.8\;m$면적의 유출 시험포를 설치하고 1999년 3월부터 11월 사이에 발생한 26개의 강우 사상에 대하여 지표 유출수량과 토양 유실량을 측정하였으며 이들과 함께 발생하는 질소와 인의 유실량을 조사하였다. 시험 포장에는 화학비료와 혼합유박비료로 질소와 인이 각각 112, 46kg/ha씩 처리되었다 조사 기간 동안 발생한 총 표면 유출수량은 $421.5\;m^3/ha$이었고 토양 유실량은 1,989kg/ha이었다. 유출수중의 T-N, $NO_3-N$, $NH_4-N$, T-P 및 $PO_4-P$의 농도는 각각 $4.7{\sim}171.0,\;0.1{\sim}188.0,\;0.13{\sim}3.36,\;0.58{\sim}4.99$ 및 $0.05{\sim}3.71\;mg/l$ 범위였다 강우에 의해 지표면으로 유실된 총 질소량은 16.39 kg/ha였으며 이중 질산태 질소와 암모늄태 질소가 각각 75%와 3%를 차지하였다. 인의 유실량은 총 16.39 kg/ha였으며 이 중에서 이온형태의 인이 47%였으며 토사와 함께 유실되는 인은 27% 정도였다. 질소와 인의 총 유실량은 각각 총 시비량의 9.5% 및 2.3%였다.

• 한국산학기술학회논문지
• /
• 제2권2호
• /
• pp.91-94
• /
• 2001

Glass ceramics composed of (5-X)$Li_2O$ㆍ$XAg_2O$ㆍ36CaOㆍ$20TiO_2$.27$P_2O_5$(X=1 to 5) were prepared by melting process and 2 step heat treatment for nucleation at$610^{\circ}C$ and crystallization at $730^{\circ}C$, Fabricated crystal phases were $LiTi_2(PO_4)_3$(LTP),$AgTi_2(PO_4)_3$(AgTP)와 $\beta-Ca_3(PO_4)$. Antibacterial effects and characterizations of the glass ceramics as $Ag_2$O content were investigated. Staphylococcus aureus and Salmonella typhi were used in this study. Staphylococcus aureus and Salmonella typhi bacteria were removed 5 hours added after glass ceramics.