• 한국식품과학회지
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• 제33권5호
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• pp.582-588
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• 2001

단체급식용으로 납품되는 생계육에서 Salmonella를 분리하여 생육제어를 위한 생리특성을 분석하였다. 계육의 총균수는 표피의 내부 살부위에서도 표피 균수의 약 10%정도가 검출되었으며 75 개 계육시료로부터 선택배지를 사용하여 분리한 후 최종적으로 51 주의 Salmonella를 동정하였다. 이들 균주 중 약 70%의 Salmonella는 4종 이상의 항생제에 내성을 보이는 다제내성균으로 보여 국내에서의 기 분리균에 비해서 높은 비율의 항생제에 대한 내성을 나타내었다. 이들 Salmonella에 대한 여러 가지 위생처리제인 유기산의 중 lactic acid와 trisodium phosphate를 agar disk diffusion으로 표준균주인 S. typhimurium ATCC 14028, S. typhimurium ATCC 12023, S. heidelberg and S. enteritidis(isolated from egg)와 비교하였다. Lactic acid는 분리된 Salmonella나 표준균주 모두 비슷한 정도의 내성을 보여 주었고 오히려 분리 Salmonella는 더 내성이 적었다. 그러나 최근에 중요시되는 trisodium phosphate에는 표준균주에 비하여 분리된 wild type에서 내성이 강한 균주가 거의 절반에 가까운 정도로 많음을 알 수가 있었다. 또한 trisodium phosphate에 대한 내성은 처리시간과 처리 후 재생배지에 따라 다르게 보여서 이들은 환경에 따 라 내성이 다르게 나타난다는 것을 알았다. 계육에 오염된 Salmonella는 wild type이므로 실제 위생처리제로 사용할 때는 좀더 철저한 처리가 요망되었다. 그러므로 집단 급식소에 납품되는 계육은 브로일러 사육단계에서의 항생제 관리와 도계과정으로부터 세균오염을 줄여야 하는 노력과 함께 이러한 식중독균의 제어를 위한 위생처리제에 대한 지속적인 기술개발도 필요할 것이다.

• 상하수도학회지
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• 제19권4호
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• pp.404-410
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• 2005

A series of batch type adsorption experiments were performed to remove aquatic phosphorus, where the layered double hydroxide (HTAL-CI) was used as an powdered adsorbent. It showed high adsorption capacity (T-P removal: 99.9%) in the range of pH 5.5 to 8.8 in spite of providing low adsorption characteristics (pH<4). The adsorption isotherm was approximated as a modified Langmuir type equation, where the maximum adsorption amount (50.5mg-P/g) was obtained at around 80mg-P/L of phosphorus concentration. A phosphate ion can occupy three adsorption sites with a chloride ion considering the result that 1 mol of phosphate ion adsorbed corresponded to the 3 moles of chloride ion released. Although the chloride ion at less than 1,000mg-CI/L did not significantly affect the adsorption capacity of phosphate, carbonate ion inhibited the adsorption property.

• 한국인쇄학회지
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• 제15권2호
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• pp.77-90
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• 1997

Positive type presensitized offset plate developer were blended by quantitative analysis method. The test had been proceeeded to check variation of developability, shelf life and tone reproduction by SiO2/Na2O ratio to PS plate developer, added glycerin, and sodium phosphate with glycerin. This study of tone reproduction had been tested 5 times to get accuracy by PS platesusing kodak CCG C-3, KMS. The test result of tone reproduction of presensitized offset plates can be summarized as follows ; major compositions in positive type plate developer were Na, Si, K and P, developability were increased by Sio2/NaO2 ratio in positive type plate developer. Shelf life can be kept by add glycerin to positive type plate developer. Tone reproduction were improved by sodium phosphate due to buffer action while shelf life can be kept by add glycerin in positive type plate developer.

• 생명과학회지
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• 제18권6호
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• pp.878-883
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• 2008

생물비료의 개발을 위하여 분리된 난용성 인산염의 가용화능이 우수한 균주인 Aeromonas hydrophila DA33의 분자육종을 위해 인산가용화 관련 유전자를 도입하였다. E. coli의 gdh 유전자를 도입한 A. hydrophila DA33은 GDH 활성이 증가하여 유전자가 발현됨을 확인하였으며, wild type에 비해 GDH 활성이 약 40% 정도 높게 나타났으며, 이는 도입된 gdh 유전자의 발현에 의한 것으로 보여 진다. 이 균주는 인산가용화에 기여하는 유기산인 gluconate의 생성도 증가하였다. A. hydrophila DA33의 wild type과 gdh 유전자를 도입한 A. hydrophila pGHS/DA33의 난용성 인산염 가용화능을 실험한 결과, gdh 유전자를 도입한 균주의 인산 가용화능이 약 1.4배 정도의 효과를 보였다. 지금까지의 결과로 비춰볼때 앞으로 생물 비료로서의 A. hydrophila DA33 이용 가능성을 나타내며, 분자육종균 A. hydrophila pGHS/DA33은 생물비료로서의 효율성을 가질 것으로 기대된다.

• Food Science and Biotechnology
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• 제17권4호
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• pp.794-798
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• 2008

Guar gum and $\kappa$-carrageenan were investigated as a substitutes for phosphate in pork meat processing. Emulsion-type pork sausages were prepared in which 0.5% phosphate was used for the control, and either $\kappa$-carrageenan or guar gum were added at levels of 0.1 or 0.5% for comparison. The hydrocolloid compounds significantly enhanced water holding capacity and cooking loss. However, hardness, cohesiveness, and chewiness were not well-maintained when compared to the control; this was attributable to the altered water distribution as well as enhanced water holding capacity of the sausages by the addition of $\kappa$-carrageenan and guar gum. Furthermore, the phosphate-free sausages had similar storage stability as the phosphate-added sausage. Overall, the results suggest that $\kappa$-carrageenan or guar gum can be used in place of phosphate in conventional processing to successfully prepare phosphate-tree pork sausages.

• 상하수도학회지
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• 제35권6호
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• pp.455-463
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• 2021

The adsorption process using GAC is one of the most secured methods to remove of phosphate from solution. This study was conducted by impregnating Cu(II) to GAC(GAC-Cu) to enhance phosphate adsorption for GAC. In the preparation of GAC-Cu, increasing the concentration of Cu(II) increased the phosphate uptake, confirming the effect of Cu(II) on phosphate uptake. A pH experiment was conducted at pH 4-8 to investigate the effect of the solution pH. Decrease of phosphate removal efficiency was found with increase of pH for both adsorbents, but the reduction rate of GAC-Cu slowed, indicating electrostatic interaction and coordinating bonding were simultaneously involved in phosphate removal. The adsorption was analyzed by Langmuir and Freundlich isotherm to determine the maximum phosphate uptake(q_m) and adsorption mechanism. According to correlation of determination(R²), Freundlich isotherm model showed a better fit than Langmuir isotherm model. Based on the negative values of q_m, Langmuir adsorption constant(b), and the value of 1/n, phosphate adsorption was shown to be unfavorable and favorable for GAC and GAC-Cu, respectively. The attempt of the linearization of each isotherm obtained very poor R². Batch kinetic tests verified that ~30% and ~90 phosphate adsorptions were completed within 1h and 24 h, respectively. Pseudo second order(PSO) model showed more suitable than pseudo first order(PFO) because of higher R². Regardless of type of kinetic model, GAC-Cu obtained higher constant of reaction(K) than GAC.

• Elastomers and Composites
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• 제49권4호
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• pp.313-322
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• 2014

난연제 가운데 가장 많이 사용되는 할로겐 함유 난연제는 사용상 환경적인 제한을 받고 있어서 비할로겐타입인 인계에 기초한 난연제가 각광을 받고 있다. 난연제는 수지에 가해지는 경우에 흔히 열분해와 기계적 특성저하를 일으킨다. 물성의 열화를 최소화하고 충분한 난연성을 얻기 위한 시도로 새로운 난연제에 대한 연구를 수행하였다. 본 연구에 있어서는 diaryl alkyl phosphate esters, aromatic phosphate esters 및 phosphonium nitron 난연제 등 세가지 형태의 비할로겐 인계에 기초한 난연제를 합성하여 GC, IR 및 TGA 등으로 합성 및 열적 특성을 확인하였다.

• Macromolecular Research
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• 제14권5호
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• pp.491-498
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• 2006

The thermal degradation of poly(hexamethylene guanidine) phosphate (PHMG) was studied by dynamic thermogravimetric analysis (TGA) and pyrolysis-GC/MS (p-GC). Thermal degradation of PHMG occurs in three different processes, such as dephosphorylation, sublimation/vaporization of amine compounds and decomposition/ recombination of hydrocarbon residues. The kinetic parameters of each stage were calculated from the Kissinger, Friedman and Flynn-Wall-Ozawa methods. The Chang method was also used for comparison study. To investigate the degradation mechanisms of the three different stages, the Coats-Redfern and the Phadnis-Deshpande methods were employed. The probable degradation mechanism for the first stage was a nucleation and growth mechanism, $A_n$ type. However, a power law and a diffusion mechanism, $D_n$ type, were operated for the second degradation stage, whereas a nucleation and growth mechanism, $A_n$ type, were operated again for the third degradation stage of PHMG. The theoretical weight loss against temperature curves, calculated by the estimated kinetic parameters, well fit the experimental data, thereby confirming the validity of the analysis method used in this work. The life-time predicted from the kinetic equation is a valuable guide for the thermal processing of PHMG.

• 미생물학회지
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• 제24권3호
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• pp.308-316
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• 1986

Vertical distribution of heterotrophic bacteria and physico-chemical characteristics were measuted in Kum River estuarine sediments. And interrelationship between heterotrophic bacterka and environmental factors was also studied. The type of sediment of Site 1 was silty clay, and sand at Site 2. Annual pH ranges were between 7.1 and 7.7 in the clay type sediment (Site 1) and 6.9-7.2 in the sand type sediment (Site 2). It was shown that organic matter contents were higher in the clay type sediment than those of sand type sediment. Redox potential values of sediments were decreased rapidly with depth at Site 1, but those of Sete 2 showed vertical fluctuation. Nitrogens(ammonia+amino acid-N, nitrate-N, nitrite-N) and phosphate in the clay type sediment showed higher values than those of sand type sediment. Annual distribution of heterotrophic bacteria were ranged $6.71{\times}10^4$ cells/g dry wt. $-2.50{\times}10^6$ cells/g dry wt. In the clay type sediment and $2.67{\times}10^3$ cells/g dry wt. $-1.94{\times}10^6$ cells/g dry wt. in the sand type sediment. Distribution of proteolytic, lipolytic, and amylolytic bacteria were decreased with the depth and the highest density was found in April and the lowest in January. Bacterial populations in sediments were closely correlated with such environmental factors as pH, redox potential, moisture content, organic matter contents, and inorganic nutrients such as nitrite-N and phosphate-P.

• Asian-Australasian Journal of Animal Sciences
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• 제25권10호
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• pp.1457-1465
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• 2012

Intestinal phosphate (Pi) absorption across the apical membrane of small intestinal epithelial cells is mainly mediated by the type IIb Na-coupled phosphate co-transporter (NaPi-IIb), but its expression and regulation in the chicken remain unclear. In the present study, we investigated the mRNA and protein levels of NaPi-IIb in three regions of chicken small intestine, and related their expression levels to the rate of net phosphate absorption. Our results showed that maximal phosphate absorption occurs in the jejunum, however the highest expression levels of NaPi-IIb mRNA and protein occurs in the duodenum. In response to a low-Pi diet (TP 0.2%), there is an adaptive response restricted to the duodenum, with increased brush border membrane (BBM) Na-Pi transport activity and NaPi-IIb protein and mRNA abundance. However, when switched from a low-(TP 0.2%) to a normal diet (TP 0.6%) for 4 h, there is an increase in BBM NaPi-IIb protein abundance in the jejunum, but no changes in BBM NaPi-IIb mRNA. Therefore, our study indicates that Na-Pi transport activity and NaPi-IIb protein expression are differentially regulated in the duodenum vs the jejunum in the chicken.