• Food Science of Animal Resources
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• v.28 no.4
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• pp.493-498
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• 2008

The aim of this work was to analyze the effects of salt and $NaNO_2$ on weight loss, proximate compositions. chemical parameters and texture characteristics of dry-cured ham processed using Korean methods. Four different treatments were considered: The HS group of 3 hams (11.30 kg) was salted with 9.2 g/kg salt (w/w) (high salt batch), the HS+$NaNO_2$ group of 3 hams (10.65 kg) was salted same as HS group and added 100 ppm $NaNO_2$. The LS group of 3 hams (11.42 kg) was salted with 6.2 g/kg salt (w/w) (Low salt batch), the LS+$NaNO_2$ group of 3 hams (10.62 kg) was salted same as LS group and added 100 ppm $NaNO_2$. The highest weight losses took place at the drying stage (27.46, 28.25, 26.99, and 28.42%). However, there were no significant differences in the weight losses between treatments (p>0.05). The moisture content was significantly affected with addition of $NaNO_2$ (p<0.05), the LS hams had significantly higher moisture content than HS+$NaNO_2$ and LS+$NaNO_2$ (p<0.05). The level of salt and $NaNO_2$ did not affect the fat, protein and ash contents. The hardness and chewiness in biceps femoris muscle from LS hams were significantly lower than in the muscles from HS+$NaNO_2$ hams (p<0.05). The $NaNO_2$ did not affect the texture characteristics of dry-cured hams. The processing conditions significantly affected the chemical parameters of biceps femoris muscle (p<0.05). The water activity in biceps femoris muscle from LS hams was significantly higher than in muscles from HS and HS+$NaNO_2$ hams (p<0.05). The salt content in biceps femoris muscles from LS+$NaNO_2$ hams was significantly lower than in the muscles from HS and HS+$NaNO_2$ hams (p<0.05). The $NaNO_2$ treatment did not affect the $NaNO_2$ content in biceps femoris muscles (p>0.05). The processing conditions did not significantly affect the lightness (L), redness (a), and $h^{\circ}$ of biceps femoris muscles (p>0.05). The yellowness (b) and chroma in biceps femoris muscle from HS+$NaNO_2$ hams were significantly higher than in the muscles from HS and LS hams.

• Korean Chemical Engineering Research
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• v.50 no.4
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• pp.627-631
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• 2012

Sodium borohydride, $NaBH_4$, shows a number of advantages as hydrogen source for portable proton exchange membrane fuel cells (PEMFCs). The durability of Co-P-B/Cu catalyst for sodium borohydride hydrolysis reaction was studied. The effect of reaction temperature, $NaBH_4$ concentration, NaOH concentration and calcination temperature of catalyst on the durability of Co-P-B/Cu catalyst were measured. The gel formed during hydrolysis reaction affected the durability of catalyst (loss of catalyst). Formation of gel increased the loss of the catalyst. When $NaBH_4$ concentration was high and reaction temperature was higher than $60^{\circ}C$, loss of catalyst was low because gel was not formed. But under the temperature of $40^{\circ}C$, loss of catalyst increased due to gel formation When $NaBH_4$ concentration was 40 weight % and the reaction temperature was $40^{\circ}C$, the loss of catalyst increased as the NaOH concentration increased. As the calcination temperature of catalyst decreased, the loss of catalyst decreased and the activity of catalyst decreased. Calcination of the catalyst at high temperature enhanced the durability of catalyst but diminished the activity of catalyst.

• Transactions of the Korean hydrogen and new energy society
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• v.21 no.5
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• pp.383-389
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• 2010

Co-B, Co-P-B, Co-Ni-B and Co-Ni-P-B catalysts supported on Ni foam were prepared using electroless plating in the present study. The surface morphology of the catalysts/Ni foam was observed using SEM and EDS analysis. The Co-Ni-P-B/Ni foam catalyst showed the superior performance on hydrogen generation due to the uniform formation of catalyst particles on the Ni foam surface. The characteristics of hydrogen generation with Co-Ni-P-B/Ni foam catalyst was investigated at the variety of $NaBH_4$ and NaOH concentrations. Durability test was performed, resulting in the stable hydrogen generation for 6 hours.

• Journal of Environmental Science International
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• v.20 no.10
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• pp.1337-1345
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• 2011

The removal performances of divalent heavy metal ions ($Pb^{2+}$, $Cu^{2+}$, $Cd^{2+}$, $Sr^{2+}$ and $Mn^{2+}$) were studied using the Na-P1 zeolite synthesized from Jeju scoria in the batch and continuous fixed column reactor. The uptakes of heavy metal ions by synthetic Na-P1 zeolite decreased in the order of $Pb^{2+}$ > $Cu2^{2+}$ > $Cd^{2+}$ > $Sr^{2+}$ > $Mn^{2+}$ based on the selectivity of each ion to ionic exchange site of Na-P1 zeolite for single and mixed solutions in batch or continuous fixed column reactor. For mixed solution, each heavy metal ion uptake was lower than that in single solution, and especially the uptake for $Mn^{2+}$ decreased greatly. In batch reactor, the uptakes of heavy metal ions by synthetic Na-P1 zeolite were described by Freundlich or Langmuir equation, but they followed the former better than the latter. In continuous fixed column reactor, the maximum ion exchange capacity obtained for each of heavy metal ions, was about 90----- of that in batch reactor. The uptakes of heavy metal ions by synthetic Na-P1 zeolite increased with the increase of initial heavy metal concentration and solution pH, and the decrease of the amount and particle size of synthetic zeolite.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.6
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• pp.693-698
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• 1997

Drought resistance and salt resistance of seedlings were compared with the polyethylene glycol(P.E.G) and NaCl solutions of the same osmotic potential($\Psi_\pi$=-10 bar). Plant height, seedling dry weight, chlorophyll content and leaf water potential decreased while the free proline content increased more in the P.E.G. than in the NaCl solution. Free amino acids increased 2.6 times in the P.E.G. solution and 3.6 times in the NaCl solution more than in the untreated(Hoagland's solution). Free proline occupied 66% and 61% of the content of total amino acids under water stress and salt stress, respectively. Besides free proline, phenylalanine in the P.E.G. solution and phenylalanine, alanine and asparagine in the NaCl solution increased distinctly. In short, it was shown that water and salt stress responses in seedling stage were relatively similar.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.2
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• pp.297-302
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• 2011

Acid drainage generated by pyrite oxidation has caused the acidification of soil and surface water, the heavy metal contamination and the corrosion of structures in abandoned mine and construction sites. The applicability of Na-acetate (Na-OAc) buffer and/or Na-silicate solution was tested for suppressing pyrite oxidation by reacting pyrite containing rock and treating solution and by analyzing solution chemistry after the reaction. A finely ground Mesozoic andesite containing 10.99% of pyrite and four types of reacting solutions were used in the applicability test: 1) $H_2O_2$, 2) $H_2O_2$ and Na-silicate, 3) $H_2O_2$ and 0.01M Na-OAc buffer at pH 6.0, and 4) $H_2O_2$, Na-silicate and 0.01M Na-OAc buffer at pH 6.0. The pH in the solution after the reaction with the andesite sample and the solutions was decreased with increasing the initial $H_2O_2$ concentration but the concentrations of Fe and $SO_4^{2-}$ were increased 10 - 20 times. However, the pH of the solution after the reaction increased and the concentrations of Fe and $SO_4^{2-}$ decreased in the presence of Na-acetate buffer and with increasing Na-silicate concentration at the same $H_2O_2$ concentration. The solution chemistry indicates that Na-OAc buffer and Na-silicate suppress the oxidation of pyrite due to the formation of Fe-hydroxide and Fe-silicate complex and their coating on the pyrite surface. The effect of Na-OAc buffer and Na-silicate on reduction of pyrite oxidation was also confirmed with the surface examination of pyrite using scanning electron microscopy (SEM). The result of this study implies that the treatment of pyrite containing material with the Na-OAc buffer and Na-silicate solution reduces the generation of acid drainage.

• The Korean Journal of Physiology and Pharmacology
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• v.7 no.3
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• pp.187-191
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• 2003

$Na^+/H^+$ exchanger (NHE) has a critical role in regulation of intracellular pH (pHi) in the renal proximal tubular cells. It has recently been shown that dopamine inhibits NHE in the renal proximal tubules. Nevertheless, there is a dearth of information on the effects of long-term (chronic) dopamine treatment on NHE activities. This study was performed to elucidate the pHi regulatory mechanisms during the chronic dopamine treatments in renal proximal tubular OK cells. The resting pHi was greatly decreased by chronic dopamine treatments. The initial rate and the amplitude of intracellular acidification by isosmotical $Na^+$ removal from the bath medium in chronically dopamine-treated cells were much smaller than those in control. Although it seemed to be attenuated in $Na^+$-dependent pH regulation system, $Na^+$-dependent pHi recovery by NHE after intracelluar acid loading in the dopamine-treated groups was not significantly different from the control. The result is interpreted to be due to the balance between the stimulation effects of lower pHi on the NHE activity and counterbalance by dopamine. Our data strongly suggested that chronic dopamine treatment increased intrinsic intracellular buffer capacity, since higher buffer capacity was induced by lower resting pHi and this effect could attenuate pHi changes under extracellular $Na^+$-free conditions in chronically dopamine-treated cells. Our study also demonstrated that intracellular acidification induced by chronic dopamine treatments was not mediated by changes in NHE activity.

• Tuberculosis and Respiratory Diseases
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• v.65 no.5
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• pp.379-384
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• 2008

Background: Sputum decontamination with NALC-NaOH (N-acetyl-L-cysteine-sodium hydroxide) is known to better detect Mycobacterium tuberculosis (M. tb) by culture than that with using NaOH, which is widely used in Korean hospitals. In this report, sputum samples collected from pulmonary tuberculosis (TB) patients were treated with either NaOH or NALC-NaOH, and we compared the results of smear and culture positivity to determine whether the NALC-NaOH treatment method improves culture positivity in the sputum samples, and especially for those sputum samples that are smear negative and scanty. Methods: For each decontamination method, 436 sputum samples from pulmonary TB patients in the National Masan Tuberculosis Hospital were collected for this study. Sputum from a patient was collected two times for the first and second day of sampling time, and these samples were employed for the decontamination process by performing the 4% NaOH and NALC-2% NaOH treatment methods, respectively, for detecting M. tb by an AFB (Acid Fast Bacilli) smear and also by culture in solid Ogawa medium. Results: The NaOH and NALC-NaOH treatment methods did not significantly affect the AFB smear positivity of the sputum samples (33.0% vs 39.0%, respectively, p=0.078). However, the culture positive percents of M. tb in the Ogawa medium treated with NALC-NaOH and NaOH were 39.7% and 28.0%, respectively, which was a significantly different (p=0.0003). This difference in culture was more prominent in the sputum samples that were smear negative (the positive percents with NALC-NaOH and NaOH were 15.8% and 7.2%, respectively, p=0.0017) and scanty (NALC-NaOH and NaOH were 60.8% and 42.9%, respectively, p=0.036), but not for a smear that was 1+ or higher (p>0.05). Conclusion: NALC-NaOH treatment is better than NaOH treatment for the detection of M. tb by culture, but not by smear, and especially when the AFB smear is negative and scanty.

• Microbiology and Biotechnology Letters
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• v.50 no.2
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• pp.211-217
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• 2022

Sodium hypochlorite (NaClO) is a disinfectant widely used in hospitals and food industries because of its antimicrobial activity against not only bacteria but also fungi and virus. The antibacterial activity of NaClO lies in the maintenance of a stable hypochlorous acid (HClO) concentration, which is regulated by pH of the solution. HClO can easily penetrate bacterial cell membrane due to its chemical neutrality and the antibacterial activity of NaClO is thought to depend on the concentration of HClO in solution rather than hypochlorite ions (ClO^-). In this study, we investigated the antibacterial activity of NaClO according to pH adjustment by means of time kill test and assays of Reactive Oxygen Species (ROS) and adenosine triphosphate (ATP) concentration changes before and after NaClO treatment. We also investigated that the degree of cell wall destruction through field emission scanning electron microscopy (FE-SEM). Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) exposed to 5 ppm NaClO at pH 5 exhibited 99.9% mortality. ROS production at pH 5 was 48% higher than that produced at pH 7. In addition, the ATP concentration in E. coli and S. aureus exposed to pH 5 decreased by 94% and 91%, respectively. As a result of FE-SEM, it was confirmed that the cell wall was destroyed in the bacteria by exposing to pH 5 NaClO. Taken together, our results indicate that the antibacterial activity of 5 ppm NaClO can be improved simply by adjusting the pH.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.21 no.5
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• pp.210-213
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• 2011

Glass-ceramics composed of $5Na_2O-36CaO-10TiO_2-xP_2O_5$ could be obtained with $P_2O_5$ content as following procedure: 1) leaching out $Ca_3(PO_4)_2$ crystals between $Ca_3(PO_4)_2$ and $NaTi_2(PO_4)_3$ selectively in 1 N HCl solution for 2 days, and 2) exchanging $Na^+$ ion to $Ag^+$ ion in Ag($NO_3$) solution for 1 day. Scanning electron microscope (SEM) and X-rat diffractometer (XRD) were measured to verify the proper synthesis of glass-ceramics. And anti-bacteria test was accomplished using Staphylococus aureus bacteria. In the results of anti-bacteria test, the bacteria were died perfectly after 3 hours.