• Journal of Astronomy and Space Sciences
• /
• 제36권2호
• /
• pp.75-86
• /
• 2019

UV Psc is a typical RS CVn type system undergoing dynamic chromosphere activity. We performed photometric observations of the system in 2015 and secured new BVR light curves showing well-defined photometric waves. In this paper, we analyzed the light curves using Wilson-Devinney binary code and investigated the orbital period of the system. The combination of our light curve synthesis with the spectroscopic solution developed by previous investigators yielded the absolute parameters as: $M_1=1.104{\pm}0.042M_{\odot}$, $R_1=1.165{\pm}0.025R_{\odot}$, and $L_1=1.361{\pm} 0.041L_{\odot}$ for the primary star, and $M_2=0.809{\pm}0.082M_{\odot}$, $R_2=0.858{\pm}0.018R_{\odot}$, and $L_2=0.339 {\pm}0.010L_{\odot}$ for the secondary star. The eclipse timing diagram for accurate CCD and photoelectric timings showed that the orbital period may vary either in a downward parabolic manner or a quasi-sinusoidal pattern. If the latter is adopted as a probable pattern for the period change, a more plausible account for the cyclic variation may be the light time effect caused by a circumbinary object rather than an Applegate-mechanism occurring via variable surface magnetic field strengths.

• The Korean Journal of Physiology
• /
• 제20권1호
• /
• pp.53-63
• /
• 1986

과산화수소$(H_2O_2)$가 급성 일산화탄소(CO)중독의 회복에 미치는 영향을 알아보기 위하여 가토를 1% Corktm에 30분간 노출시킨후 자연회복군, 100%산소 흡입군 및 $H_2O_2$관장군(10ml/kg의 0.5% $H_2O_2$용액을 2ml내외의 사람혈액과 함께 관장)으로 나누어, 회복기 15,30,60 및 90분에 동맥혈의 $pH,\;PCO_2,\;CO_2$ 및 HbCO 포화도를 측정하여 다음과 같은 결론을 얻었다. pH는 급성 CO중독시 3개군 모두에서 감소하였고, 회복기에는 서서히 증가하여 자연회복군과 100%산소 흡입군은 회복기 90분에 거의 회복되나, $H_2O_2$관장군에서는 pH의 회복이 다른군보다 늦었다. $PaCO_2$는 급성 Co중독시 3개군 모두에서 감소하였고, 회복기에는 서서히 증가하였으나, 자연회복군의 $PaCO_2$는 회복기 90분에 거의 회복하는데 반하여 100%산소흡입군과 $H_2O_2$관장군의 $PaCO_2$는 회복이 늦었고 회복기 90분에도 완전히 회복되지 못하였다. $PaO_2$는 급성 Co중독시 약간 감소하였다가 회복기에는 회복기 15분부터 급격히 증가하였고 회복기 90분까지 대조치보다 높은 $PaO_2$를 유지하였다. 회복기동안 $H_2O_2$관장군의 $PaO_2$는 $102{\sim}107mmhg$로 자연회복군보다 약 10 mmhg 높은 수준을 보였다. HbCO 포화도는 급성 CO중독시 $54{\sim}72%$까지 증가하였다. 회복기에는 $H_2O_2$관장군의 HbCO 포화도의 회복이 자연회복군이나 100%산소 흡입군보다 빨랐으며, 100%산소 흡입군은 회복기 30분에서 60분사이에 자연회복군보다 더 빠른 회복을 보였다. 이상의 결과에서 0.5% $H_2O_2$관장은 CO중독시 혈액의 산소분압을 어느정도 증가시킬 뿐 아니라 혈색소와 결합된 CO의 해리를 촉진시켜, 단독요법 또는 산소요법과 병행하여 사용할 때 급성CO중독에 효과적인 치료법이 될 수 있을 것으로 사료된다.

• Journal of Astronomy and Space Sciences
• /
• 제4권2호
• /
• pp.69-80
• /
• 1987

Okazaki(1997)의 2색(V와B)의 광전측광에 의한 광도곡선을 Wilson and Devinney모델을 이용하여 T LMi의 광전궤도요소를 구하였으며 지금까지 발표된 이 별의 극심시각을 문헌으로 수집하여 궤도공전주기변화를 분석하였다.T LMi의 공전주기 변화는 simusoidal한 주기변화를 나타내며 그 진폭은 $0.^{d}0425$ 이고 장주기변화는 $62.^{y}01$ 로 나타났다. 한편, 이번 연구에서 얻어진 T LKi의 물리적 성질에 따르면 이 별은 "R CMa" 형으로 분류한다는 것은 재검토가 있어야 하겠다.검토가 있어야 하겠다.

• 한국농업기계학회:학술대회논문집
• /
• 한국농업기계학회 1997년도 하계 학술대회 논문집
• /
• pp.89-98
• /
• 1997

This study was conducted to develop an automatic nutrient-solution control system for small-scale growers. The nutrient-solution control system consisted of a low-cost and precise metering device and a personal computer. The system controlled electric conductivity(EC) and pH of nutrient-solution based on the time-based feedback control method with the information about temperature, EC, and pH of the nutrient-soIution. The performance of the nutrient-solution control system was evaluated through the control of EC and pH while compared with those of commercial nutrient-solution control system. Also an experimental cultivation of tomato was conducted to verify and to improve the developed system. Results of this study were as follows. 1. An automatic nutrient-solution control system based on a low-cost and precise metering device was developed. 2. The developed system controlled EC and pH within $\pm$0.05 mS/cm and $\pm$0.2 pH full scale error respectively at $24^{/circ}C$. 3. When using the commercial system, the controlled values of EC and pH of the 500l of water were 1.29 mS/cm and 6.1 pH for the setting points of 1.4 mS/cm and 6.0 pH respectively at $22^{/circ}C$. 4. The developed nutrient-solution control system showed $\pm$0.05 mS/cm of deviation from the setting EC value over the experimental cultivation period. 5. The deviation from the average values of Ca and Mg mass content in the several nutrient-solution were 0.5% and 1.8% respectively.

• 대한약침학회지
• /
• 제6권2호
• /
• pp.105-111
• /
• 2003

Objective : The purpose of this study was to investigate the stability of bee venom according to the keeping method and period. Method : The author observed microbial contamination of bee venom in nutrient agar, broth, YPD agar and YPD media and antibacterial activity for S. aureus, E. coli manufactured 12, 6 and 3 months ago as the two type of room temperature and $4^{\circ}C$ cold storage. Results : 1. 1:3,000 and 1:4,000 diluted bee venom solution did not show microbial contamination both room temperature and cold storage within twelve months. 2. There was antibacterial activity of diluted bee venom for S. aureus in cold storage within twelve months and there was no antibacterial activity of diluted bee venom for S. aureus in twelve months, room temperature storage. 3. We could not observe the zone of inhibition around paper disc of all for E.coli. in 1:3,000, 1:30,000 and 1:3,000,000 diluted bee venom solution, respectively. According to results, we expect that diluted bee venom solution is stable both cold and room temperature storage within twelve months.

• Journal of Chest Surgery
• /
• 제13권4호
• /
• pp.321-337
• /
• 1980

The increasing use of cardioplegic solution for the reduction of ischemic tissue injury requires that all cardiplegic solution be carefully assessed for any protective or damaging properties. This study describes functional, enzymatic and structural assessment of the efficiency of three cardioplegic solutions (Young & GIK, Bretschneider, and $K^{+}$ Albumin solution) in a Modified Isolated Rat Heart Model of cardiopulmonary bypass and ischemic arrest. Isolated rat heart were subjected to a 2-minute period of coronary infusion with a cold cardioplegic or a noncardioplegic solution immediately before and also at the midpoint of a 60-minute period of hypothermic ($10{\pm}1$. C) ischemic cardiac arrest. The results of this study were as follow: 1. Spontaneous heart beat after ischemic arrest occured 16 seconds later after Langendorff reperfusion in the Young & GIK group (n=6), and 40 second later in the Bretschneider group (n=6) and 6 minute later in the $K^{+}$ Albumin group (n=6), and 16 minute later in the control group (non-cardioplegia). A good recovery state of spontaneous heart beat was shown in the Young & GIK and Bretschneider groups. 2. The percentage of recorveries of heart function at 30 minute after postischemic working heart perfusion were : heart rate $91.6{\pm}3.1$% (P<0.01)m oeaj airtuc oressyre $83{\pm}3$% (P<0.01), coronary flow $70{\pm}8$% (P<0.05) and aortic flow flow rate $39{\pm}9.3$% (P<0.05) in the Young & GIK group. This percentage of recoveries of the Young & GIK group was significantly greater than the control group. In the Bretschneider group, the percentage of recoveries were : heart rate $87.8{\pm}7.5$%(P<0.05), peak aortic pressure $71{\pm}2.3$% (P<0.05) and aortic flow rate $33.2{\pm}6.6$%(P<0.05). hte percentage of recoveries were significantly greater than in the control group. In the $K^{+}$ Albumin group, recoveries of heart function were poor. 3. Total CPK leakage was $131.2{\pm}12.75$IU/30 min/gm. dry weight in the control group, $50.65{\pm}12.75$IU in the Young & GIK gruop, $69.40{\pm}32.21$Iu in Bretschneider group, and $103.65{\pm}15.47$IU in the $K^{+}$ Albumin group during the 30 minute postischemic Langendorff reperfusion. Total CPK leakage was significantly less (P<0.001) in the Young & GIK group, than in the control group. 4. Direct correlatin between percentage recovery of aortic flow rate and total amount of CPK leakage from Myocardium was noticed.(Correlation Coefficient r = 0.76, P<0.001). 5. Mild perivascular edema was the only finding of light microscopic study of myocardium after 60 minute ischemic arrest with cold cardioplegic solutions and hypothermla.

• 자원환경지질
• /
• 제38권6호
• /
• pp.657-662
• /
• 2005

Extractions fro fertilizer and soil samples were performed to yield the operationally defined fractions 'soluble' chromate (extractable with $NH_4NO_3$), 'exchangeable' chromate (extractable with phosphate buffer pH 7.2), and these results were compared with the data obtained by extractions with ammonium sulfate, borate buffer pH 7.2, saturated borax pH 9.6, and polyphosphate (Graham's salt). In order to maintain the pH of extractant solution about constant, the concentration of extractant buffer had to be raised to at least 0.5 M. The results strongly depended on the kind of extractant, and the solid: liquid ratio. For most of the samples investigated, the extraction efficiency increased in the order borate-sulfate-nitrate-phosphate. Whereas the recovery of $K_2CrO_4\;and\;CaCrO_4$ added to the samples of basic slags prior to the extraction was about complete, the recovery of added $PbCrO_4$ was highly variable. In soil extracts, the color reaction was interfered from co-extracted humics, which react with the chromate in weak acid solution during the time period necessary for color reaction (1 hour). However, this problem can be overcome by standard addition and subtraction of the color of the extractant solution. In soil extract of about pH < 7, organic material reduced chromate during the extraction period also, and standard addition of soluble chromate is recommended to prove recovery and the stability of chromate in the samples. In admixtures of soils and basic slags, results for hexavalent chromium were lower than from the mere basic slags. This effect was more pronounced in phosphate than in nitrate extracts. As a proficiency test, samples low in organic carbon from contaminated sites in Hungary were tested. The results from $NH_4NO_3$ extracts satisfactorily matched the results of the Hungarian labs obtained from $CalCl_2$ extractants.

• 환경생물
• /
• 제17권2호
• /
• pp.183-190
• /
• 1999

The bioleaching of heavy metals from fly ash was performed by Thiobacillus thiooxidans MET isolated from the enrichment culture of an anaerobically digested sludge. The effect of solid concentrations on the efficiency of metal leaching was studied in shaken flasks. In the range of solid concentrations 20 g.L­$^1$to 100 g.L­$^1$T. thiooxidans MET oxidized S$^{0}$ to sulfate without any lag period. The final pH of slurry solution was decreased to below pH 1, and the final oxide-redox potential (ORP) was increased to over 420 mV in the solid concentrations below 100 g.L­$^1$. However, the initial lag period of 4 to 8 days was required to obtain the pH reduction and ORP increase of the slurry solutions in the range of solid concentrations 150 g.L­$^1$to 300 g.L­$^1$. The sulfur oxidation rate of T. thiooxidans MET in 20~100 g.L­$^1$solid concentrations was 0.70~0.75 g-S.L­$^1$ㆍ d­$^1$, but its sulfur oxidation activity was remarkably inhibited with increasing solid concentration over 150 g.L­$^1$. Increasing fly ash solids concentration in the range of solids concentration 20 g.L­$^1$ to 200 g.L­$^1$decreased the removal efficiency of Zn, Cu, Mn, Cr and Pb. The solubilization of heavy metals from fly ash was strongly correlated with the pH value of slurry solution. When the pH of slurry solution was reduced to 3, the solubilization process of Zn, Cu and Mn started, and their solubilization efficiency of Zn, Cu and Mn was progressively increased below pH 2. However, the solubilization process of Cr and Pb started at pH 2.5 and 2.0, respectively.

• 한국대기환경학회지
• /
• 제29권1호
• /
• pp.56-63
• /
• 2013

This study was aimed at developing and evaluating a diffusive sampling method using a barium hydroxide solution as an absorbent for measuring carbon dioxide ($CO_2$) in ambient air. The collected $CO_2$ concentration was calculated by the change of conductivity resulted in the reaction of $CO_3{^{2-}}$ and $Ba^{2+}$ in aqueous solution. The sampling rate for the diffusive sampler was determined 0.218 mL/min, as obtained from the slope of the linear correlation between the $CO_2$ mass collected by the diffusive sampler and the time-weighted $CO_2$ concentration with the active sampling method. The unexposed blank sampler sealed in aluminium foil-polyethylene laminated packets has remained stable during at least one-month storage period. A good correlation was observed between the diffusive sampler and active sampler with a coefficient of determination of 0.956. This diffusive sampler would be suitable for the indoor $CO_2$ concentration monitoring.

• 한국작물학회지
• /
• 제50권1호
• /
• pp.28-31
• /
• 2005

To identify salt-tolerance characteristics of corn seedling was treated in solution of 0, 50 and 100 mM NaCl of hydroponic cultivation. In photosynthesis of corn seedling, there was no large difference between 50mM and 0 mM NaCl solution, however, in 100 mM NaCl solution, the tolerance gradually decreased to $76\%,\;49\%,\;and\;31\%$ after one day, four days, and seven days, respectively, in comparison to 0 mM NaCl solution. Osmotic potential of corn in seedling period was significantly decreased with increasing saline level, however, free proline content in the plant on the ground was significantly increased with increasing saline level and with the lapse of time. In terms of correlation among major characteristics, there was a highly significant positive difference between osmotic pressure potential and photosynthesis, However, highly negative correlation was found between osmotic pressure potential and free proline content. In addition, it was expected that young seedling of corn with saline tolerance may be utilized in the transplantation in salt-accumulated land. Based on above-shown result, in terms of saline tolerance of Chalok-2 variety, growth suppression was serious with 100mM NaCl solution. However, growth was expected that seedling growth would be favorable under 50 mM NaCl solution.