• KIEAE Journal
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• 제10권5호
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• pp.131-137
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• 2010

The building industry must aim at high-durability and sustainability. A holistic life cycle based approach is recommended to reduce the environmental load. In recent years, technical innovations in the construction industry have advanced to a great extent, and caused the active research and development of high-performance and multifunctional construction materials. Nowadays, various polymer powders have been commercialized to manufacture construction materials in the form of prepackaged-type products, which have rapidly been developed for lack of skilled workmen in construction sites. Recently, terpolymer powders of improved quality have been developed and commercialized as cement modifiers. And, hydrocalumite is a material that can adsorb the chloride ions (Cl-) causing the corrosion of reinforcing bars and liberate the nitrite ions (NO2-) inhibiting the corrosion in reinforced concrete, and can provide a self-corrosion inhibition function to the reinforced concrete. The purpose of this study is to ascertain the self-corrosion inhibition function of polymer-modified mortars using redispersible powders with hydrocalumite. Polymer-modified mortars using VA/E/MMA and VAE redispersible powders are prepared with various calumite contents and polymer-binder ratios, and tested for chloride ion penetration depth, corrosion inhibition. As a result, regardless of the polymer-binder ratio, the replacement of ordinary portland cement with hydrocalumite has a marked effect on the corrosion-inhibiting property of the polymer-modified mortars. Anti-corrosion effect of polymer-modified mortars using VA/E/MMA terpolymer powder with hydrocalumite is higher than that of VAE copolymer powder.

• The Korean Journal of Physiology and Pharmacology
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• 제5권3호
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• pp.231-241
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• 2001

The mammalian cortical collecting duct (CCD) plays a major role in regulating renal NaCl reabsorption, which is important in $Na^+$ and $Cl^-$ homeostasis. The M-1 cell line, derived from the mouse cortical collecting duct, has been used as a mammalian model of the study on the electrolytes transport in CCD. M-1 cells were grown on collagen-coated permeable support and short circuit current $(I_{sc})$ was measured. M-1 cells developed amiloride-sensitive current $5{\sim}7$ days after seeding. Apical and basolateral addition of ATP induced increase in $I_{sc}$ in M-1 cells, which was partly retained in $Na^+-free$ or $Cl^--free$ solution, indicating that ATP increased $Na^+$ absorption and $Cl^-$ secretion in M-1 cells. $Cl^-$ secretion was mediated by the activation of apical cystic fibrosis transmembrane regulator (CFTR) chloride channels and $Ca^{2+}-activated$ chloride channels, but $Na^+$ absorption was not mediated by activation of epithelal sodium channel (ENaC). ATP increased cAMP content in M-1 cells. The RT-PCR analysis demonstrated that M-1 cells express $P2Y_2,\;P2X_3\;and\;P2Y_4$ receptors. These results showed that ATP regulates $Na^+$ and $Cl^-$ transports via multiple P2 purinoceptors on the apical and basolateral membranes in M-1 cells.

• The Korean Journal of Physiology and Pharmacology
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• 제15권5호
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• pp.285-289
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• 2011

Shilajit, a medicine herb commonly used in Ayurveda, has been reported to contain at least 85 minerals in ionic form that act on a variety of chemical, biological, and physical stressors. The substantia gelatinosa (SG) neurons of the trigeminal subnucleus caudalis (Vc) are involved in orofacial nociceptive processing. Shilajit has been reported to be an injury and muscular pain reliever but there have been few functional studies of the effect of Shilajit on the SG neurons of the Vc. Therefore, whole cell and gramicidin-perfotrated patch clamp studies were performed to examine the action mechanism of Shilajit on the SG neurons of Vc from mouse brainstem slices. In the whole cell patch clamp mode, Shilajit induced short-lived and repeatable inward currents under the condition of a high chloride pipette solution on all the SG neurons tested. The Shilajit-induced inward currents were concentration dependent and maintained in the presence of tetrodotoxin (TTX), a voltage gated $Na^+$ channel blocker, CNQX, a non-NMDA glutamate receptor antagonist, and AP5, an NMDA receptor antagonist. The Shilajit-induced responses were partially suppressed by picrotoxin, a $GABA_A$ receptor antagonist, and totally blocked in the presence of strychnine, a glycine receptor antagonist, however not affected by mecamylamine hydrochloride (MCH), a nicotinic acetylcholine receptor antagonist. Under the potassium gluconate pipette solution at holding potential 0 mV, Shilajit induced repeatable outward current. These results show that Shilajit has inhibitory effects on the SG neurons of Vc through chloride ion channels by activation of the glycine receptor and $GABA_A$ receptor, indicating that Shilajit contains sedating ingredients for the central nervous system. These results also suggest that Shilajit may be a potential target for modulating orofacial pain processing.

• 한국건설순환자원학회논문집
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• 제7권3호
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• pp.262-270
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• 2019

본 논문에서는 페로니켈슬래그 미분말 및 혼화재의 복합사용에 따른 모르타르의 강도 및 내구성 평가를 실시하였다. 페로니켈슬래그 및 생석회, 석고, 염화칼슘을 OPC 대비 20%로 치환하여 복합사용 하였으며, 휨강도 및 압축강도, SEM분석을 통한 모르타르의 강도 평가를 실시하였다. 석고를 혼화재로 사용하였을 때 초기강도 발현은 보이지만, 페로니켈슬래그 및 생석회, 염화칼슘을 혼화재로 복합사용 하였을 때 강도발현과 강도증진효과가 극대화 되었으며, 혼화재의 적절한 복합사용이 미세한 공극 채움과 밀도개선효과로 인해 강도와 내구성 개선에 영향을 주는 것으로 판단된다. 또한 화학적침식저항성 및 XRD 분석을 통해 혼화재의 적절한 복합사용은 수화 생성물인 Muscovite의 함량에 따라 강도가 증가하는 경향을 보였고, 규산염은 산 알칼리에는 용해되지 않으므로 화학적 침식 저항 성능이 OPC에 비하여 우수한 것으로 사료된다.

• 셀메드
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• 제9권1호
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• pp.2.1-2.6
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• 2019

Decoction of Cocos nucifera husk fibre is used indigenously in Nigeria for malaria treatment. Polyphenols have been identified as the phytochemicals responsible for the antimalarial activity of Cocos nucifera husk fibre, though their toxicity has not been evaluated. The polyphenols of Cocos nucifera husk fibre were therefore evaluated for their effects on selected kidney function indices in mice. Fifty mice were randomly divided into five groups (A-E) of ten mice each. Mice in group A were orally administered 5% DMSO solution while those in groups B, C, D and E were orally administered 31.25, 62.5, 125 and 250 mg/Kg body weight of the polyphenols respectively for seven days. Serum urea, creatinine and uric acid concentrations were determined. Serum levels of sodium, potassium, chloride and calcium ions and kidney alkaline phosphatase (ALP), glutamate dehydrogenase (GDH) and gamma-glutamyltransferase (GGT) activities were also determined. The results showed that the polyphenols significantly reduced (p<0.05) urea concentration at 250 mg/Kg body weight and creatinine concentration at all doses compared to controls. The polyphenols caused no significant alteration (p>0.05) in serum uric acid concentration and kidney ALP, GGT and GDH activities compared to controls. There was significant increase (p<0.05) in serum sodium ion concentration at 31.25, 125 and 250 mg/Kg body weight of polyphenols whereas significant increase (p<0.05) in serum potassium and chloride ions was observed at 62.5 and 250 mg/Kg body weight compared to controls. Thus, polyphenols of Cocos nucifera husk fibre may adversely affect some osmoregulatory functions of the kidney, especially at higher concentrations.

• 한국지하수토양환경학회지:지하수토양환경
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• 제29권3호
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• pp.23-36
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• 2024

Miryang City, the study area, has a water supply rate of 87.4%, which is 12% lower than the national water supply rate of 99.4%, but has a high dependence on groundwater due to the high ratio of farms. In agricultural areas, contamination becomes relatively more critical, requiring significant attention to the management and conservation of groundwater resources. This study aims at estimate groundwater vulnerability of Miryang City using the DRASTIC index map, Piper diagram, and water quality data to correlated with the DRASTIC index. The results from DRASTIC map were divided into five classes: very high, high, moderate, low, and very low. The areas in central and southern part of study area, which are characterize by a very high index with [Ca-Cl] and [Na-Cl] water types, covering a large alluvium with the Miryang River and Nakdonggang River. In addition, a correlation analysis between groundwater quality parameters and the DRASTIC index was carried out. Chloride, sodium, and sulfate ions showed a weak relationship with DRASTIC index, with correlation coefficient was 0.507, 0.487 and 0.344, respectively. These results suggest that aquifer media, soil media, hydraulic conductivity, and chloride ion are important factors for groundwater vulnerability.

• 대한화학회지
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• 제37권2호
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• pp.228-236
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• 1993

Grignard 시약,CH_3$MgI와 브로모벤질과의 반응은 전자전달과정(SET)과 라디칼 이온쌍 중간체를 거쳐 생성되는 동종짝지음 생성물 bibenzyl을 주생성물로 이온성 공격에 의해 생성되는 교차짝지음 생성물, 에틸벤젠을 부생성물로 생성시키며 전이금속 불순물이 거의 제거된 순수 금속 Mg으로 CH_3$MgI을 제조하였을 때 그 비는 78:22이었다. 그러나 실험실용 금속 Mg을 사용하였을 때 그 비는 감소하여 67:33이었으며 이 비는 촉매량으로 첨가시킨 $FeCl_3$ 양의 증가로 더욱 감소되어 최고 20:80 비로 Fe 이온은 이온성 교차생성물, 에틸벤젠을 주생성물로 유도하였으며 이러한 반응결과는 좋은 수소원자주게로 디이소프로필 에테르를 디에틸 에테르 대신 용매를 사용하였을 때에도 큰 변화가 관찰되지 않았다. 이러한 관찰은 Grignard 시약과 유기할로겐 화합물이나 카르보닐 화합물과의 반응에서 촉매 양의 전이금속염이 전자전달과정 속도를 증가시켜 동종짝지음 이합체 생성물의 증가를 일으키는 보고와 반대의 경향을 보인다. 이러한 촉매량의 $FeCl_3$ 첨가가 CH_3$MgI의 이온성 공격의 증가와 그에 따른 교차짝지음 생성물의 증가로 유도하는 것은 브로모벤질과 반응 중 생성된 Fe 종과의 착화합물 형성에 의해 벤질탄소-브롬 결합이 CH_3$MgI의 탄소음이온 공격에 대해 반응성이 증가되는 것으로 설명하였다. 이러한 설명은 2-페닐-1-브로모에탄의 CH_3$MgI와의 반응연구에서 관찰된 반응성 결여가 뒷받침하고 있다.

• Journal of Biosystems Engineering
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• 제35권5호
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• pp.343-349
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• 2010

Rapid on-site sensing of nitrate-nitrogen and potassium ions in hydroponic solution would increase the efficiency of nutrient use for greenhouse crops cultivated in closed hydroponic systems while reducing the potential for environmental pollution in water and soil. Ion-selective electrodes (ISEs) are a promising approach because of their small size, rapid response, and the ability to directly measure the analyte. The capabilities of the ISEs for sensing nitrate and potassium in hydroponic solution can be affected by the presence of other ions such as calcium, magnesium, sulfate, sodium, and chloride in the solution itself. This study was conducted to investigate the applicability of two ISEs consisting of TDDA-NPOE and valinomycin-DOS PVC membranes for quantitative determinations of $NO_3$-N and K in hydroponic solution. Nine hydroponic solutions were prepared by diluting highly concentrated paprika hydroponic solution to provide a concentration range of 3 to 400 mg/L for $NO_3$-N and K. Two of the calibration curves relating membrane response and nutrient concentration provided coefficients of determination ($R^2$) > 0.98 and standard errors of calibration (SEC) of < 3.79 mV. The use of the direct potentiometry method, in conjunction with an one-point EMF compensation technique, was feasible for measuring $NO_3$-N and K in paprika hydroponic solution due to almost 1:1 relationships and high coefficients of determination ($R^2$ > 0.97) between the levels of $NO_3$-N and K obtained with the ion-selective electrodes and standard instruments. However, even though there were strong linear relationships ($R^2$ > 0.94) between the $NO_3$-N and K concentrations determined by the Gran's plot-based multiple standard addition method and by standard instruments, hydroponic $NO_3$-N concentrations measured with the ISEs, on average, were about 10% higher than those obtained with the automated analyzer whereas the K ISE predicted about 59% lower K than did the ICP spectrometer, probably due to no compensation for a difference between actual and expected concentrations of standard solutions directly prepared.

• 멤브레인
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• 제14권2호
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• pp.108-116
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• 2004

본 연구에서는 비대칭 polyvinylidene fluoride (PVDF)막을 기질막으로 하여 Pore-filled 이온교환막을 제조하였다. 먼저 다공성 PVDF막의 기공에 80%의 chloromethylate aryl ring을 가지고 있는 poly(vinylbenzyl chloride) (PVBCI)과 1,4- diaminobicyclo［2,2,2］octane (DABCO)을 tetrahydrofuran (THF)와 dimethylforamide (DMF)가 8:2로 혼합된 용액에 녹여서 채워 넣고 겔화시킨 후, 남아 있는 chloromethyl group에 trirnethylamine (TMA, 40 wt% in water)을 이용하여 양이온 암모니움 site를 형성시키면 pore-filled 음이온교환막이 형성된다. 이와 같이 2단계의 제조 방식으로 제조된 pore-filled 막은 크기의 변화가 없으며, 가교도의 조절로써 최종 막의 특성이 간단하게 조절되는 것을 보여주었다. SEM과 AFM의 표면촬영의 결과로부터 기질막의 기공 내에 고분자겔의 존재를 확인하였다. 투과도와 배제율에 많은 영향을 미치는 용매를 조사한 결과 tetrahydrofuran (THF)만을 사용하여 제조한 막보다 THF와 DMF를 함께 사용할 때 더 우수한 막이 제조되었다. 제조된 최종 막의 수투과도 조사결과, 가교도 10% 막의 경우 아주 낮은 압력에서(100 Kpa) 전형적인 한외여과막의 투과도(8∼10 kg/$m^2$hr)를 보여주었으며 배제율 또한 우수한 결과(55∼60%)를 보여주었다. 압력에 대한 pore-filled 이온교환막의 성능을 관찰한 결과 압력이 증가할수록 투과도와 배제율은 함께 증가하였다.

• 한국토양비료학회지
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• 제41권5호
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• pp.310-317
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• 2008

포화추출액중 전기전도도는 $1.0\sim28.4dS\;m^{-1}$의 범위로 평균 $4.8dS\;m^{-1}$를 나타내어 매우 높은 농도로 염류가 집적되고 있었다. 전기전도도 $4dS\;m^{-1}$ (포화추출액 조건으로 환산)를 초과한 경우가 전체의 55%를 차지하고 있었다. 복분자 비가림하우스 재배토양 중 전기전도도와 각각의 무기이온과의 단순상관관계를 조사한 결과, 전기전도도와 염소 ($r=0.85^{**}$), 질산 ($r=0.94^{**}$), 인산 ($r=0.88^{**}$), 황산 ($r=0.84^{**}$) 이온과 같은 음이온과 고도의 유의성 있는 정(+)의 상관관계를 나타내었고, 마그네슘 ($r=0.41^*$), 칼슘 ($r=0.38^*$), 칼리 ($r=0.47^*$) 이온과 같은 양이온과는 유의성 있는 정(+)의 상관관계를 나타내었다. 비가림 하우스형 복분자 재배토양 중에 함유되어 있는 염류집적 유발물질을 제거하는데 있어 작업의 편이성, 농업용수의 절감 및 처리시간 등을 고려하였을 때 용탈법보다 수세법이 더 효과적인 것으로 나타났다.