Borate 완충용액에서 Ni의 부동화 피막의 생성과정(growth kinetics)과 부동화 피막의 전기적 성질을 변전위법, 대 시간 전류법 그리고 단일 주파수 또는 다중 주파수 전기화학적 임피던스 측정법으로 조사하였다. 이때 생성되는 산화피막은 Mott-Schottky 식이 적용되는 p-형 반도체 성질을 보였으며, 낮은 전극전위에서 생성되는 Ni의 부동화 피막 $Ni(OH)_2$는 전극 전위가 증가하면서 NiO, NiO(OH)로 변화되는 것을 알 수 있었다.

The oxidative decarboxylation of phenylsulfinylacetic acid (PSAA) by Cr(VI) in 20% acetonitrile -80% water (v/v) medium follows overall second order kinetics, first order each with respect to [PSAA] and [Cr(VI)] at constant [$H^+$] and ionic strength. The reaction is acid catalysed, the order with respect to [$H^+$] is unity and the active oxidizing species is found to be $HCrO_3^+$. The reaction mechanism involves the rate determining nucleophilic attack of sulfur atom of PSAA on chromium of $HCrO_3^+$ forming a sulfonium ion intermediate. The intermediate then undergoes ${\alpha}$,${\beta}$-cleavage leading to the liberation of $CO_2$. The product of the reaction is found to be methyl phenyl sulfone. The operation of substituent effect shows that PSAA containing electron-releasing groups in the meta- and para-positions accelerate the reaction rate while electron withdrawing groups retard the rate. An excellent correlation is found to exist between log $k_2$ and Hammett ${\sigma}$ constants with a negative value of reaction constant. The ${\rho}$ value decreases with increase in temperature evidencing the high reactivity and low selectivity in the case of substituted PSAAs.

Corrosion inhibition of 304 stainless steel (SS) in 1 M HCl by aqueous extract of coriander seeds was studied using weight loss, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and electrochemical frequency modulation (EFM) techniques. Values of inhibition efficiency obtained are dependent upon the concentration of extract and temperature. Generally, inhibition was found to increase with inhibitor concentration, but decrease with temperature. Physical adsorption mechanism has been proposed for the inhibition with Langmuir adsorption isotherm obeyed. Values of activation energy of the inhibited corrosion reaction of 304 SS are greater than the value obtained for the blank. Thermodynamic consideration reveals that adsorption of aqueous extract of coriander seeds 304 SS surface is spontaneous.

In the course of work on new pharmacologically active antimicrobial agents, we have reported the synthesis of a new class of structurally novel derivatives, incorporating two bioactive structures, a benzothiazole and thiazolidin-4-one, to yield a class of compounds having interesting antimicrobial properties. The antimicrobial properties of the synthesized compounds were investigated against bacteria (Staphylococcus aureus and Escherchia coli) and fungi (Candida albicans and Aspergillus niger) using serial plate dilution method. The structure of the synthesized compounds have been established by elemental analysis and spectroscopic data.

A facile transformation of aryl aldehydes to benzyl iodides through one-pot reductive iodination is reported. This protocol displays remarkable functional group tolerance and the title compound was obtained in good to excellent yield.

Catalytic performance of Lewis acids have been investigated in the synthesis of 1,2,3,4-tetrahydroquinolines via cyclocondensation reaction of aniline derivatives with cyclic enol ethers such as 3,4-dihydro-2H-pyran and 2,3-dihydrofuran. The catalytic activity of various of these catalysts in different solvents was compared with other classical catalysts such as KSF clay (1.5 g), $InCl_3$ (10-20 mol%), $ZrOCl_2$ (10 mol%), $Sc(OTf)_3$ (3 mol%), PANI-$InCl_3$ (10 mol%), $I_2$ (20 mol%), $InCl_3$ (5 mol%), 4-npa (25 mol%) and Cellulose-$SO_3H$ (0.03 g).

Different pyrazoline derivatives (6a-h and 7a-h) were synthesized by cyclization of substituted chalcones with hydrazine hydrate in acidic as well as basic conditions. Both the reactions were performed under conventional heating and microwave irradiation and percentage yields were compared. All the reactions were accelerated in acidic and basic conditions under microwave irradiation, with higher yields. All the synthesized compounds were characterized by their spectral study (IR, MS, $^1H$ and $^{13}C$ NMR) and were tested for their antibacterial and antifungal activity. The compounds 6g and 7g exhibited significant activity against S. aureu, 7g against E. faecalis, 6b and 7b against E. coli and 6b, 6c, 7b, 7c against S. typhi. The compounds 6d and 7d exhibited significant activity against C. albicans and 6c against M. luteus. Rest of the synthesized compounds showed moderate to poor activity against tested species with compared to standard.

The 4-(1H)-benzotriazoyl methyl amino benzoate 3 was prepared by Mannich reaction of benzotriazole 1, ethyl-paminobenzoate 2 and formaldehyde. The prepared compound 3 then react with hydrazine hydrate results in the 4-(1H)-benzotriazoyl methyl amino benzoyl hydrazide 4. This compound on condensation with pre-prepared different ethyl 2-(2-(4-(4-substituted phenyl)thiazol-2-yl)hydrazono)-3-oxobutanoates 6a-d, furnished 1-(4-((1H-benzo[d] [1,2,3] triazol-1-yl)methyl amino) benzoyl)-4-(2-(4-(4-substituted phenyl)thiazol-2-yl) hydrazono)-3-methyl-1H-pyrazol-5(4H)-one 7a-d. All the compounds 7a-d was characterized by spectral studies. The compounds showed significant antimicrobial activity against various bacteria and fungi.

In the present study a novel series of (2-substituted-4-methylthiazol-5-yl)(4-substituted piperazin-1-yl)methanone derivatives were synthesized by reaction of 2-substituted-4-methylthiazole-5-carboxylic acid with N-substituted benzyl piperazine by using 1-ethyl-3-[3-(dimethylamino)propyl]carbodiimide hydrochloride (EDCl) and 1-hydroxybenzotriazole (HOBt) in DMF. All the newly synthesized compounds were characterized by spectral methods. The title compounds were screened for in vitro antibacterial activity. Most of the compounds show moderate to good antimicrobial activity.

Petroleum refining unavoidably generates large volumes of oily wastewater. The environmentally acceptable disposal of oily wastewater is a current challenge to the petroleum industry. Nowadays, more attentions have been focused on the treatment techniques of oily wastewater. Oily wastewater contained highly concentrated and toxic organic compounds. Wet peroxide oxidation (WPO) and catalytic wet oxidation (CWO) were applied to eliminate pollutants to examine the feasibility of the WPO/CWO of oily wastewater. The results indicated that more than 80% chemical oxygen demand (COD) removal from oily wastewater was achieved with CWO. Homogenous catalyst, $NaHCO_3$ and $Na_2CO_3$ and NaOH showed effective removal for pollutants in oily wastewater. Greater than 90% COD removal was achieved with WPO. It was concluded that WPO was a far more effective process for oily wastewater.

In the presence of zeolites, 4,4'-dibromobiphenyl could be region-selectively nitrated by the action of nitrogen dioxide and molecular oxygen. The ratio of 4,4'-dibromo-2-nitrobiphenyl to 4,4'-dibromo-3-nitrobiphenyl could reach 14 in a high yield of 90%. Zeolites could be easily regenerated by heating and reused four times to give the results similar to those obtained with fresh catalyst. Compared with the classic nitration method, no nitric acid and sulfuric acid were used, which suggested that the method was an environmentally economic process.

Petroleum refinery effluents are waste originating from industries primarily engaged in refining crude oil. It is a very complex compound of various oily wastes, water, heavy metals and so on. Conventional processes are unable to effectively remove the chemical oxygen demand (COD) of petroleum refinery effluents. Supercritical water oxidation (SCWO) was proposed to treat petroleum refinery effluents. In this paper, methanol was used to investigate co-oxidative effect of methanol on petroleum refinery effluents treatment. The results indicated that supercritical water oxidation is an effective process for petroleum refinery effluents treatment. Adding methanol caused an increase in COD removal. When reaction temperature is $440^{\circ}C$, residence time is 20 min, OE is 0.5 and initial COD is 40000 mg/L, and COD removal increases 8.5%.

The process of petroleum involves in a large amount of oily wastewater that contains high levels of chemical oxygen demand (COD) and toxic compounds. So they must be treated before their discharge into the receptor medium. In this paper, wet peroxide oxidation (WPO) was adopted to treat the oily wastewater. Central composite design, an experimental design for response surface methodology (RSM), was used to create a set of 31 experimental runs needed for optimizing of the operating conditions. Quadratic regression models with estimated coefficients were developed to describe the COD removals. The experimental results show that WPO could effectively reduce COD by 96.8% at the optimum conditions of temperature $290^{\circ}C$, $H_2O_2$ excess (HE) 0.8, the initial concentration of oily wastewater 3855 mg/L and reaction time 9 min. RSM could be effectively adopted to optimize the operating multifactors in complex WPO process.

The corrosion behavior of aluminum and mild steel in hydrochloric acid medium was studied using a nicotinic acid hydrazide as inhibitor by potentiodynamic polarization, electrochemical impedance spectroscopy technique and gravimetric methods. The effects of inhibitor concentration and temperature were investigated. The experimental results suggested, nicotinic acid hydrazide is a good corrosion inhibitor for both aluminum and mild steel in hydrochloric acid medium and the inhibition efficiency increased with increase in the inhibitor concentration. The polarization studies revealed that nicotinic acid hydrazide exhibits mixed type of inhibition. The inhibition was assumed to occur via adsorption of the inhibitor molecules on the aluminum and mild steel surface and inhibits corrosion by blocking the reaction sites on the surface of aluminum.

The pH sensitive hydrogels composed of N-isopropylacrylamide (NIPA) and acryloyl phenylalanine (APA) were prepared by redox polymerization using N,N'-methylenebisacrylamide (MBA) as a crosslinker. Anti-inflammatory and analgesic agent, Keterolac Tromethamine (KT), was loaded successfully into poly(NIPA-co-APA) copolymeric hydrogels by swelling equilibrium method. To understand the nature of drug in the polymeric matrix, the newly synthesized drug loaded poly(NIPA-co-APA) copolymeric hydrogels were characterized by using differential scanning calorimetry (DSC) and X-ray diffraction (XRD) techniques. The scanning electron microscopy (SEM) technique result indicates the spherical smooth surface of the hydrogels. The drug (KT) releasing nature of the poly(NIPA-co-APA) hydrogels was studied in pH 1.2 and 7.4. Effects of drug loading, crosslinking agent, pH and the ionic strength of the external medium on swelling of hydrogels were also investigated.

Magnetite nanoparticles were prepared by co-precipitation method and then silica was coated onto the surface of $Fe_3O_4$ by hydrolysis of TEOS. The silica coated magnetite nanoparticles were characterized for its structural, microstructural, optical, vibrational and magnetic properties by X-ray diffraction analysis, Scanning electron microscopy, UV-visible spectroscopy, Infrared spectroscopy and Vibration sample magnetometer, respectively. XRD study confirmed the presence of $SiO_2$ on the surface of magnetite nanoparticles. SEM study indicated that with increase in TEOS content the particles become bigger and mono-disperse. It was also found that the silica coating prevents magnetic particles from aggregation and imparts excellent stability.

이 연구의 목적은 예비화학교사들이 사범대학에서 수강한 과학교육 과목은 학습관과 어떠한 관련성을 갖는지를 고찰하는 것이었다. 이를 위해, 예비교사 3인의 학습관 및 수강한 과학교육 과목과 관련한 설문과 면담을 실시하였다. 연구 결과, 예비교사들은 과학교육 과목의 수강을 통해 자신의 학습관을 변화, 수정하거나 유지, 강화하는 모습을 보였다. 과학교육 과목을 수강하기 전에 지녔던 예비교사 K와 P의 전통적 학습관은 과학교육 과목의 수강을 통해 구성주의적 학습관으로 변화하였다. 그러나 구성주의 학습관은, 학교 현장 실제성에 바탕을 둔 과학교육 과목 수강 이후에 다시 현장의 수업 상황을 고려하여 수정되고 변형되었다. 예비교사 H는 이전부터 지녔던 구성주의적 학습관에 전통적 학습관을 추가하여 지니게 되었다. 이로부터 정도와 방향의 차이는 있지만 예비교사 K, P, H 모두 과학교육 과목의 수강을 통해 학습관을 고찰하고 수정하는 것을 알 수 있다. 이러한 연구 결과는, 이론의 현장 적용을 강조한 과학교육 과목이 예비교사들로 하여금 자신의 학습관을 고찰하고 수정할 수 있는 기회를 제공한다는 것을 보여주는 것으로써, 교원 양성대학의 과학교육 과목의 내용에 현장성이 많이 반영되어야 할 것이며, 예비교사별 맞춤식 교수활동 및 학습관 정립을 위한 예비교사의 반성적 사고과정이 포함되어야 할 것임을 시사한다.

이 연구의 목적은 Nature-Study의 형성 과정을 역사적으로 고찰함으로써 오늘날 이루어지고 있는 과학교육의 방향과 의미를 재고하여 시사점을 찾는 것이다. Nature-Study의 사상은 실물 교육을 강조한 캄파넬라, 라트케, 코메니우스, 페스탈로치 등의 사상에 기초하고 쉘던의 사물학습, 아가시의 자연사, 파커의 진보주의에 의해 형성되었다. Nature-Study는 방법적 측면에서는 사물학습의 '실물 주제 중심의 학습', 내용적 측면에서는 자연사의 '자연에 대한 학습', 철학적 측면에서는 진보주의의 '학습자 중심의 학습'에 영향을 받아 발전해 나갔다. 아가시의 제자로 쉘던의 오스위고 사범학교와 파커의 쿡 카운티 사범학교에서 근무한 스트레이트는 이 세 영역을 종합화하여 Nature-Study 형성의 기틀을 마련하였다. 이어 쿡 카운티 사범학교의 잭만은 Nature-Study를 교과로서 확립시켰으며 코넬 대학의 베일리와 콤스톡은 미국 Nature-Study 협회를 구성하여 대중화에 공헌하였다. 그러나 교육자들이 점차 통합적인 Nature-Study를 거부하고 직접 경험보다 교과서를 중요하게 여기면서 1920년대 이후 Nature-Study가 쇠퇴하게 되었다. 과학교육에서 Nature-Study 정신은 통합과 실제적 학습을 강조하는 오늘날 과학교육에 있어 자연을 주제로 한 통합교육, 자기주도적 학습, 자연과의 교감, 학습자의 인격 형성에 큰 역할을 할 것으로 판단된다.

본 연구는 과학학습의 어려움이나 낮은 흥미도의 한 원인으로 과학 교과학습에서의 중요한 통로 혹은 입구에 해당하는 문지방개념의 존재를 가정하고 특히 화학의 어떠한 개념들이 여기에 해당하는지를 알아보았다. 또한, 각 개념의 속성이 무엇이며 개념을 이해하고 "아~하"의 깨달음을 얻는 경험은 어떠했는지도 함께 알아보았다. 이를 위해, 화학 II를 학습한 239명의 고등학생이 연구에 참여하였고 설문에 대한 응답으로 화학 교과의 어려운 개념이 무엇인지, 문지방에 해당하는 개념이 무엇인지, 혹은 문지방개념을 이해한 경험이 화학 학습에 어떠한 영향을 주었는지를 설명하였다. 몰과 원자구조가 화학 교과의 문지방개념으로 제시되었고 구체적으로는 제시된 두 개념이 문지방개념이 되는 속성이 무엇인지를 집중적으로 분석하였다. 문지방을 극복하고 이해하는 것은 각자의 경험에 따르지만, 문지방개념을 분석하는 기준은 각각의 경험에 일정한 준거를 제시하여 서로 다른 경험들을 객관화 시킬뿐 아니라 개념의 과학적 의미와 본성을 잘 드러내어 준다. 특히, 교사가 제시하는 화학의 문지방개념을 조사한 사전연구와의 비교는 문지방개념의 통합적 속성이 학생들의 학습과 과학흥미도 증진에 중요함을 보여준다.