• 한국재료학회:학술대회논문집
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• 한국재료학회 2003년도 추계학술발표강연 및 논문개요집
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• pp.101-101
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• 2003

• 자원리싸이클링
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• 제27권5호
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• pp.23-29
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• 2018

일반적으로 탄산니켈을 제조하기 위한 원료로 $NiSO_4$ 및 $NiCl_2$가 사용되었다. 제조된 탄산니켈의 경우 표면 및 내부에 있어 $Na_2SO_4$ 및 NaCl이 생성되어 탄산니켈의 순도를 감소시키는 원인이 되고 있으며, 이러한 불순물의 제거정도에 따라 고순도 탄산니켈을 제조할 수 있다. 본 연구에서는 니켈MHP 용매추출 공정으로 제조된 $NiCl_2$를 이용하여 탄산니켈제조 연구를 진행하였다. 실험은 니켈염과 탄산염 당량비에 따른 제조, 탄산니켈 수세에 따른 탄산니켈 내 Na 및 Cl 감소 및 수세용수의 온도에 따른 Na 및 Cl의 감소에 대한 조건을 실험하여 고순도 탄산니켈을 제조할 수 있었다.

• Korean Chemical Engineering Research
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• 제56권4호
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• pp.555-560
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• 2018

$NaCl-KCl-ZnCl_2$ 혼합물(NaKZn-Chloride)의 열물성을 조사하여 열저장 매체로서의 잠재성을 평가하였다. 고온용 축열물질로 이용하기 위해서는 축열온도 범위에서 안정된 열물성을 유지하여야 하는데, 사전실험 결과 해당 혼합물은 알려진 고온안정온도인 $850^{\circ}C$ 보다 훨씬 낮은 온도에서 급격한 분해가 진행되었다. 이에 본 연구에서는, 흡수된 수분에 의해 축열물질의 열적 성질이 변화되는지 확인하고자 하였다. 혼합물의 수분함량에 따라 열물성이 변화되는 지를 열물성 장비로 측정하였으며, 가열-냉각 반복실험을 통해 다시 한 번 확인하였다. 그 결과 녹는 점의 경우 흡수된 수분에 관계없이 일정하지만, 고온 안정성의 경우 흡습한 샘플에서 다소 낮아지는 것을 알 수 있었다. 본 연구결과에 따라 흡습성을 가지는 고온 축열물질을 사용하는 시스템에서 수분과의 접촉을 줄임으로써 축열물질의 손실을 줄일 수 있다.

• 한국미생물·생명공학회지
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• 제22권2호
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• pp.175-181
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• 1994

A bacterial strain producing highly viscous polysaccharide(A29 POL) was isolated from soil and identified sa Bacillus sp. A29. The cultural conditions of the Bacillus sp. A29 for the polysaccharide prouction were dextrin 12%, soytone 0.2%, SnCl$_{2}$ $\cdot $2H$_{2}$O 0.02%, Na$_{2}$HPO$_{4}$ $\CDOT $12H$_{2}$O 0.36%, L-alanine 0.01%, initial pH6.8, and 30$\circ $C at pH 3 FOR 4 days. Final viscosity of the culture broth was 65, 000 cp and then the amount of produced polysaccharide was 8.3 g/l. A29 POL was composed of glucose and xylose. A29 POL showed high viscosity at low concentration(0.1%) and in the presence of the salts such as NaCl or CaCl$_{2}$. A29 POL showed high viscosity acid condition and at alkali condition and high pseudoplasticity in the presence of a NaCl or CaCl$_{2}$. It was shown that the viscosity at high temperature(80$\circ $C) was decreased but it was recovered at low temperature (20$\circ $C. A29 POL was able to from film and gel in the presence of MgSO$_{4}$ $\CDOT $7H$_{2}$O, Na$_{2}$CO$_{3}$ \CDOT $H$_{2}$O, MnSO$_{4}$ $\CDOT $ 7H$_{2}$O. A29 POL had anionic charge.

• Tribology and Lubricants
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• 제20권2호
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• pp.91-96
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• 2004

Wear behavior of self-mated stainless steels in NaCl solution has been investigated. The experiment was done in the corrosive liquid of which NaCl concentration of $0\~3\%$ and temperature of $15\~90^{\circ}C$. Two kinds of wear type were observed: one is 'severe wear' type which shows gradually increasing wear volume with increasing sliding distances, the other is 'mild wear' type which shows change of wear rate from high value to low at transition distance. The specific wear rate in severe wear type was not sensitive to the liquid temperature and concentration of NaCl but stable at value of $1\times10^{-3}\;mm^3$ approximately.

• 대한한의학회지
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• 제23권2호
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• pp.139-150
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• 2002

OBJECTIVES : Schizandra chinensis is well known for its efficacy at liver function reinforcement, relieving thirst and recovery from fatigue. In this study, we examined the effects of sports drink containing Schizandra chinensis on serum metabolic substrate, electrolyte, stress indicators, related-enzyme and exercise performance, rectal temperature, and heat shock proteinb70 (HSP70). METHODS : Elite long-distance runners (male, 21.3yrs, n=16) were selected and divided into two groups; an experimental group (EXP, n=8) and a control group (CON, n=8). A beverage containing Schizandra chinensis was supplemented 3 times per day to EXP for 4 weeks. Serum biochemical elements (glucose, lactate, total cholesterol, triglyceride, high density lipoprotein cholesterol, glutamate oxaloacetate transaminase, glutamate pyruvate transaminase, creatinine, creatine phosphokinase, lactate dehydrogenase, blood urea nitrogen, Na, K, Cl) were analyzed by auto blood analyzer. Exercise performance was measured by treadmill exercise test, HSP70 was detected by electrophoresis and Western blotting, and rectal temperature was measured by rectal temperature probe. RESULTS : Administration of the beverage increased significantly the rest level of blood Na, Cl and glucose and decreased significantly lactate dehydrogenase, glutamate oxaloacetate transaminase. No difference was found in exercise performance, rectal temperature increment or HSP70 concentration between groups. CONCLUSIONS : Administration of a sports drink containing Schizandra chinensis altered blood glucose, lactate dehydrogenase, glutamate oxaloacetate transaminase, Na and Cl levels.

• 한국식품과학회지
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• 제36권3호
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• pp.456-460
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• 2004

L. monocytogenes가 biofilm을 생성하는데 ${\sigma}^{B}$가 어떤 영향을 미치는가를 구명하기 위해 L monocytogenes wild type인 10403S와 ${\sigma}^{B}$를 제거한 sigB null mutant의 biofilm 생성능을 고삼투압 및 저온 조건에서 비교하였다. 고삼투압 조건인 6%의 NaCl이 첨가된 BHI 배지에서 배양된 L. monocytogenes 10403S는 배양 72시간 후 $6.83{\pm}0.38\;log\;cfu/cm^{2}$의 biofilm을 생성하였으며, sigB null mutant의 경우는 $5.33{\pm}0.45log\;cfu/cm^{2}$ 의 biofilm을 생성하였는데, L. monocytogenes 10403S가 sigB null mutant보다 31.8배나 많은 biofilm을 생성하였다. 또한 L. monocytogenes 10403S를 6%의 NaCl이 첨가된 BHI 배지에서 배양했을 시 NaCl을 첨가하지 않은 배지에서 배양한 경우보다 4.7배나 많은 biofilm을 생성하였는데, L. monocytogenes 10403S와 같이 ${\sigma}^{B}$가 존재하는 경우 고삼투압 조건에서 biofilm을 더욱 많이 생성하였으며, ${\sigma}^{B}$가 biofilm의 생성에 영향을 미친다고 할 수 있었다. 또한 저온 조건($4^{\circ}C$ 배양)에서 ${\sigma}^{B}$가 biofilm 생성에 영향을 미치는지를 조사하였는데, ${\sigma}^{B}$는 저온 스트레스 시 biofilm 생성에 영향을 미치지 않는 것으로 나타났다.

• 유기물자원화
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• 제14권2호
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• pp.83-90
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• 2006

음식물 쓰레기로 만든 퇴비 중의 염분함량을 1% 이하로 조절하기 위해 지금까지 여러 가지 방법이 개발되었다. 그러나 이런 방법들은 침출수 과다로 인한 환경오염 또는 높은 설치비 등의 문제를 가지고 있어 실용화에 어려움이 있다. 염분이 충분히 제거되지 않은 음식물 쓰레기로 만든 퇴비를 농지에 사용할 경우 염해로 인한 식물의 성장 장애 및 염류축적이 일어날 수 있다. 본 연구는 음식물 쓰레기 퇴비에 함유된 염분을 $KHSO_5$, $KHSO_4$, $K_2SO_4$로 구성된 삼중염을 이용하여 분해하는 방법이며 기존 화학적 처리방법과 달리 염분을 분해하여 칼륨비료의 원료인 KCl로 전환시켰다. 또한 음식물 쓰레기 퇴비화 발효설비에서 음식물 쓰레기 600톤에 삼중염을 적용해본 결과 발효시의 온도가 평균 $5^{\circ}C$가 상승되었다. 온도상승과 함께 전처리 공정 및 발효공정에서 현저한 악취저감 효과가 나타났으며 이는 삼중염으로 인한 염분함량 감소로 호기성균의 활성화 및 악취원인물질을 효과적으로 제거하기 때문이다.

• Macromolecular Research
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• 제17권12호
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• pp.1015-1020
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• 2009

The role of the water structure present in hydrogels from nutlets of three species of salvias, S. miltiorrhiza (SM), S. sclarea (SS) and S. viridis (SV), was analyzed by differential scanning calorimetry (DSC). The sharp endothermic peaks that appeared at $5.9^{\circ}C$ (SM), $2.8^{\circ}C$ DC (SS) and $1.8^{\circ}C$ (SV) in each 1.0% hydrogel of 10.4-15.8% were not affected by addition of 0.1 M urea and alkali-metal salts. The order-disorder portions in the network were slightly affected by the distribution of freezable and non-freezable water in the hydrogel networks. The SV hydrogel was further used to investigate the effects of additives (0.1-8.0 M urea and 0.1-5.0 M NaCl) on its melting behavior. At 0.5-4.0 M urea and 1.0-3.0 M NaCl, two endothermic peaks appeared, corresponding to unbound (high temperature) and bound (low temperature) water in the gel networks, and eventually merged into one endothermic peak at 5.0-8.0 M urea and 4.0-4.5 M NaCl. After this merger, the endothermic peak shifted to 3.7, 4.0 and $5.6^{\circ}C$ at 5.0, 6.0 and 8.0 M urea, respectively. In the case of NaCl, a combination of peaks that occurred at 4.0-4.5 M were accompanied by a shift to lower temperature (-14.4 and $15.3^{\circ}C$) and the endothermic peak finally disappeared at 5.0 M NaCl due to the strong binding of water in the gel networks.

• 한국재료학회지
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• 제22권5호
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• pp.243-248
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• 2012

ZrN nanoparticles were prepared by an exothermic reduction of $ZrCl_4$ with $NaN_3$ in the presence of NaCl flux in a nitrogen atmosphere. Using a solid-state combustion approach, we have demonstrated that the zirconium nitride nanoparticles synthesis process can be completed in only several minutes compared with a few hours for previous synthesis approaches. The chemistry of the combustion process is not complex and is based on a metathesis reaction between $ZrCl_4$ and $NaN_3$. Because of the low melting and boiling points of the raw materials it was possible to synthesize the ZrN phase at low combustion temperatures. It was shown that the combustion temperature and the size of the particles can be readily controlled by tuning the concentration of the NaCl flux. The results show that an increase in the NaCl concentration (from 2 to 13 M) results in a temperature decrease from 1280 to $750^{\circ}C$. ZrN nanoparticles have a high surface area (50-70 $m^2/g$), narrow pore size distribution, and nano-particle size between 10 and 30 nm. The activation energy, which can be extracted from the experimental combustion temperature data, is: E = 20 kcal/mol. The method reported here is self-sustaining, rapid, and can be scaled up for a large scale production of a transition metal nitride nanoparticle system (TiN, TaN, HfN, etc.) with suitable halide salts and alkali metal azide.