Solvothermal synthesis of high-performance Ni-Co layered double hydroxide nanofoam electrode for electrochemical energy storage

Patel, R.,Inamdar, A.I.,Hou, B.,Cha, S.,Ansari, A.T.,Gunjakar, J.L.,Im, H.,Kim, H. ELSEVIER 2017 CURRENT APPLIED PHYSICS Vol.17 No.4

<P>A nanofoam nickel cobalt layered double hydroxide (NiCo(OH)(2)) electrode film is fabricated on a stainless-steel substrate with the use of a simple one-step solvothermal process. The nanofoam NiCo(OH)(2) electrode exhibits a high specific capacitance of 2710.2 Fig at a current density.of 9.1 A/g, and a good capacity retention of similar to 70% after 2000 charge-discharge cycles at a high current density of 31.8 A/g. An energy density of 60.23 Wh/kg is obtained at a power density of 1.8 kW/kg. The excellent electrochemical energy storage performance of the NiCo(OH)(2) electrode is due to the synergetic effect of a significantly improved ionic diffusion and an effective charge transfer, which is linked to a well-dispersed interconnected nanofoam morphology and binder-free direct contact with the current collector. (C) 2017 Elsevier B.V. All rights reserved.</P>

정화조에서 배출되는 하수관악취 저감방안 연구

조용모 ( Yong Mo Cho ),남미아 ( Mi A Nam ) 서울시정개발연구원 2009 연구보고서 Vol.2009 No.5

Outline: Recently, the urban foul odor problem is frequently happening all around Seoul area; CBD, large apartment districts, and low-lying areas where a foul water running velocity is slow. Even though a life foul odor has not been regarded as a serious problem until now, cases of civil appeal are increasing for the sewer foul odor all around Seoul along with the improvement of standard of living and frequent rise of bad smell problems especially in large buildings. The purpose of this study is deliberating the way of reducing the sewer foul odor by examining the origin and process of the urban sewer foul odor generating throughout Seoul. 2. Main results of the study The result of the survey had performed for three years, during 2006~2008, shows that the generating spot of the life sewage foul odor is increasing every year; 1,442 cases in 2006, 2,067 cases in 2007, and 2,523 cases in 2008, total 6,032 cases had been reported. 608,205 Septic tanks including polluted water purifying devices had installed in Seoul, and 11,454 tanks among them are over 500 people capacity tanks. 2) Foul odor concentration examination in Seoul The foul odor in the circumference of Yeosung Green Castle apartment was examined to find the generating characteristics of the life sewage foul odor. Yeosung Green Castle apartment is located where about 10% gradient road is continued more than 500 meters. Foul odor is severly generated at the end of this road, the entrance of a path up a mountain. The sewage foul odor of Namhyun-dong neighborhood is generated from the foul odor of Septic tanks in the houses and apartments. The result of foul odor examination showed the degree of mixed foul odor at the 1 and 2 spots of rainwater receivers are individually 144 and 208 dilution rate, and they are far over 15 that is permissible level. Hydrogen sulfide was measured 15 times higher than the permissible level, 20.0ppb, at the each spots. Methyl mercaptan also was gauged as largely exceeding 2.0ppb, the permissible level. 3) Types of life foul odor The foul odor generated in Seoul could be largely classified into five types as follows; A. the foul odor adjacent to the large buildings, B. the foul odor of small water-purifiers in single-family housing districts, C. the foul odor of sewer system in upstream hilly sections, D. the foul odor of sewer system in low-lying areas, and E. the foul odor of Storm Overflow Diverging Tanks. 4) Problems of life sewage foul odor The problems of the life sewage foul odor are as follows; A. absence of the efficient alteration of sewage foul odor prevention, B. difficulty of a origin blockade in the Septic tanks, the main source of life sewage foul odor, C. absence of a provision for prevention of life sewage foul odor in the Foul Odor Prevention Law and D. difficulty of achieving the foul odor reducing effect by resetting the quality standard of Septic thank`s discharging water. 3. Policy recommendation: 1) Basic principles for reducing ife foul odor (1) Analyzing reality of life sewage foul odor generation The foul odor is inevitably generated in most Korean buildings when discharging water of a Septic tank is influented to the sewer system. However, the foul odor prevention with improving efficiency of a Septic tank has not only much difficulty of securing effectiveness but also lack of scientific approaches. (2) Establishing basic frame for life foul odor prevention The basic frame for life foul odor prevention is as follows, Firstly, introducing the public concept, the mandatory installation and management of Septic tanks and sewer systems, to reduce the sewage foul odor. Secondly, promoting the synthesized management that focuses on a sewer pipe; moving from point control to line control Thirdly, establishing a system by adding the life sewer foul odor provision in the Foul Odor Prevention Law or legislating a new law for the preventing life sewer foul odor, Fourthly, connecting the measure for reduction of Septic tanks and sewer pipe foul odor with the sewerage maintenance, Lastly, founding the effective reduction measure with considering limited effect of a rainwater receiver for the sewer foul odor prevention. (1) Process for managing life sewer foul odor The main contents of process for the life sewer foul odor management are as follows in the order named; A. recognizing the generation spot of the life sewer foul odor, B. examining the life sewer foul odor, C. selecting sewer systems for managing the life sewer foul odor, D. requiring the reduction facility to the large buildings discharging sewage to the sewer system and water-purifying tanks over 500 people capacity by law, E. establishing the synthesized reduction plan in the selected sewer system district, and F. installing the reduction facility for the life sewer foul odor. (2) Systemic improvement for reduction of sewer foul odor Adding the sewer foul odor section in the Foul Odor Prevention Law or Sewerage Law is necessary, and legislating the municipal ordinance for the life sewer foul odor in Seoul is required. It is necessary to make installing the foul odor facility into a mandatory requirement both new construction buildings installed Septic tank over 500 people capacity or larger than 1,500 floor area, and existing buildings located within the sewer foul odor sewer system area. (3) Efficient plan for reducing foul odor in building district ① Installing plan of the foul odor reduction facility for existing buildings in the urban building districts installing vertical outlets on the building side using existing sewer pipes as an induction pipe. ② New construction buildings in single-family housing districts systemizing installing the foul odor reduction facility as mandatory requirement in the buildings both have Septic tank over 500 people capacity and larger than 1500 floor area, ③ Indistinctive source of the sewer foul odor installing the "L"type induction pipe using a street light or telephone pole as a prop. (4) Establishing a plan for sewer four odor reduction Establishing the sewer foul odor maintenance and improvement scheme is required in each district of the sewer foul odor management, On top of that, the sewer foul odor reduction study should be proceeded with the whole region of Seoul, (5) Operating sewer foul odor counterplan party under the government of Seoul The foul odor counterplan party that is consisted with professionals and public service workers should be organized, and the solutions for the foul odor should be made such as a field study, reduction programs, the allotment of facility construction in the regions where the foul odor reduction measure is urgent.

A microfluidic electrochemical aptasensor for enrichment and detection of bisphenol A.

Kashefi-Kheyrabadi, Leila,Kim, Junmoo,Gwak, Hogyeong,Hyun, Kyung-A.,Bae, Nam Ho,Lee, Seok Jae,Jung, Hyo-Il Elsevier 2018 Biosensors & bioelectronics Vol.117 No.-

<P><B>Abstract</B></P> <P>Bisphenol A (BPA) is an organic monomer used to make common consumer goods such as plastic containers, sports equipment, and cosmetics which are heavily produced worldwide. A growing interest has been drawn to general public as BPA is one of the major endocrine disrupting chemicals threating human health. To date, numerous BPA sensors have been attempted to be developed but important challenges still remained such as limited linearity range, easy to use, and long term response time. To address the present issues, a microfluidic channel should be integrated into an electrochemical aptasensor and it is called Geometrically Activated Surface Interaction (GASI) chip. The vigorous generation of the micro-vortex in the GASI fluidic chamber provides the high collision chances between BPA and anti-BPA aptamer (BPAPT) and consequently more BPA molecules can be captured on the aptasensor surface, which finally results in high sensitivity of the aptasensor. To construct the integrated aptasensor, a miniaturized gold electrode is fabricated using shadow mask and e-beam evaporation process. Afterward, BPAPT is immobilized on a nanostructured gold electrode via thiol chemistry, and other terminus of the aptamer is labeled with a ferrocene (Fc) redox probe. Then, the microfluidic channel is mounted over the miniaturized gold electrode to introduce and enrich BPA to the aptasensor. Upon the specific interaction between BPA and its aptamer, configuration of aptamer is changed so that Fc tag approaches to the electrode surface and direct oxidation signal of Fc and BPA are followed as analytical signals. The unique microfluidic integrated electrochemical aptasensor delivers a wide linear dynamic range over 5 × 10<SUP>–12</SUP> to 1 × 10<SUP>−9</SUP> M, with a limit of detection 2 × 10<SUP>–13</SUP> M. This aptasensor provides a precise platform for simple, selective and more importantly rapid detection of BPA. Such kind of sensing platforms can serve as a fertile ground for designing miniaturized portable sensors.</P> <P><B>Highlights</B></P> <P> <UL> <LI> GASI generates micro-vortex resulting in enhanced capture of BPA and subsequently enhanced sensitivity of the aptasensor. </LI> <LI> The aptasensor has low LOD, wide linear dynamic range and good response time compared to conventional aptasensors. </LI> </UL> </P>

A spick-and-span approach to the immobilization of horseradish peroxidase on Au nanospheres incorporated with a methionine/graphene biomatrix for the determination of endocrine disruptor bisphenol A

Vilian, A.T. Ezhil,Giribabu, Krishnan,Choe, Sang Rak,Muruganantham, Rethinasabapathy,Lee, Hoomin,Roh, Changhyun,Huh, Yun Suk,Han, Young-Kyu Elsevier Sequoia 2017 Sensors and actuators. B Chemical Vol.251 No.-

<P><B>Abstract</B></P> <P>In the present study, we employ a straightforward, benign strategy to prepare thiol-functionalized reduced graphene oxide (S-RGO) using methionine as the sulphur source and reducing agent. The immobilization of horseradish peroxidase (HRP) over the AuNPs/S-RGO was developed by incorporating AuNPs on the S-RGO surface. The fabricated HRP/AuNPs/S-RGO electrode exhibits a remarkable decrease in the overpotential and a significantly increased oxidation peak current of bisphenol A (BPA) compared with the bare glassy carbon electrode (GCE) and AuNPs/S-RGO electrode. The biosensor shows an excellent amperometric analytical performance with a low detection limit of 2.6×10<SUP>−12</SUP> M and a linear range from 2.0×10<SUP>−11</SUP> to 1.18×10<SUP>−9</SUP> M, with the response time <2s for BPA. From the results, the apparent Michaelis-Menten constant was calculated as 8.14nM. The HRP/AuNPs/S-RGO biosensor exhibited faster response, adequate storage stability, inexpensive, simple fabrication with disposability, satisfactory reproducibility and repeatability, and outstanding selectivity. Finally, the constructed biosensor was utilized successfully for detecting BPA in tomato juice and milk samples with acceptable results.</P> <P><B>Highlights</B></P> <P> <UL> <LI> HRP/AuNPs/S-RGO biocomposite has been prepared to determine bisphenol A. </LI> <LI> The AuNPs/S-RGO is a promising platform for HRP immobilization. </LI> <LI> The biosensor exhibits excellent stability, reproducibility and high selectivity. </LI> <LI> It exhibits LOD of 2.6×10<SUP>−12</SUP> in a wide linear range from 2.0×10<SUP>−11</SUP> to 1.18×10<SUP>−9</SUP> M. </LI> <LI> It detects bisphenol A in real samples such as tomato juice and milk. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Development of Sensitive Analytical Method of Rhodanthpyrone A by a LC-MS/MS and its Application to Bioavailability Study in Rats

Kang, Bitna,Yoon, Jeong A,Song, Im-Sook,Han, Young Taek,Choi, Min-Koo Korean Society for Mass Spectrometry 2019 Mass spectrometry letters Vol.10 No.3

A sensitive analytical method of rhodanthpyrone A in rat plasma was developed using a liquid chromatography-tandem mass spectrometry (LC-MS/MS). Rhodanthpyrone A and rhodanthpyrone B (internal standard) in rat plasma were extracted by a liquid-liquid extraction method with ethyl acetate. This extraction method gave results in high and reproducible extraction recovery in the range of 73.75-79.90% with no interfering peaks around the peak elution time of rhodanthpyrone A and B. The standard calibration curves for rhodanthpyrone A ranged from 0.5 to 2000 ng/mL were linear with $r^2$ > 0.994 and the inter- and intra-day accuracy and precision and the stability were within acceptance criteria. Using this validated analytical method, pharmacokinetics of rhodanthpyrone A following intravenous and oral administration of rhodanthpyrone A at doses of 2 mg/kg and 30 mg/kg, respectively, were investigated. Rhodanthpyrone A in rat plasma showed multi-exponential elimination pattern with high clearance and volume of distribution values. The absolute oral bioavailability of this compound was calculated as 3.7%. Collectively, the newly developed sensitive LC-MS/MS analytical method of rhodanthpyrone A could be successfully applied to investigate the pharmacokinetic properties of this compound and would be useful for the further studies on the efficacy, toxicity, and biopharmaceutics of rhodanthpyrone A.

Photocatalytic abatement of phenol on amorphous TiO2-BiOBr-bentonite heterostructures under visible light irradiation

Menelisi C. Dlamini,Mbongiseni L. Dlamini,Pumza Mente,Boitumelo Tlhaole,Rudolph Erasmus,Manoko S. Maubane-Nkadimeng,John A. Moma 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.111 No.-

A simplistic solvothermal process to fabricate novel amorphous TiO2-BiOBr-Bentonite (A-TiO2-BiOBr-Bt)multidimensional photocatalysts in this work is a practical and economically feasible technique for thefabrication of the reported photocatalysts as it is a one-pot process. The stickiness of the A-TiO2-BiOBr-Bt wet cake and the low drying temperature make A-TiO2-BiOBr-Bt a feasible platform compositefor the fabrication of the photoreactive inner coating of water treatment containers for photocatalytictreatment of drinking water. The A-TiO2-BiOBr-Bt photocatalyst with an A-TiO2:BiOBr:Bt mass ratio of1:1:2 (Ti1Bi1Bt2) displayed the highest BET surface area of 124.8 m2/g, a low bandgap of 2.86 eV, and sufficientlylow electron-hole recombination rate. The high number of A-TiO2-BiOBr p-n heterojunctions,and the Ti-O-Si and Bi-O-Si bonds between A-TiO2-BiOBr and Bt in Ti1Bi1Bt2 lowered its electron-holerecombination rate with enhanced visible light-harvesting ability. Within 70 min of visible light irradiation,150 mg of Ti1Bi1Bt2 gave 100% conversion of 100 mL of 20 ppm phenol with a pseudo-first-order rateconstant of 0.0322 min1 at pH 4.0. Scavenging experiments showed superoxide radicals (O2) and electrons(e) being the most dominant reactive oxidation species (ROS) responsible for the phenol photodegradationprocess while holes (h+) and hydroxyl radicals (OH) also exerted appreciableparticipation.

2G HTS wire with enhanced engineering current density attained through the deposition of HTS layer with increased thickness

A. Molodyk,A. Markelov,A. Valikov,V. Chepikov,A. Petrzhik,B. Massalimov,P. Degtyarenko,R. Uzkih,A. Soldatenko,Kideok Sim,Soon Hwang 한국초전도.저온공학회 2019 한국초전도저온공학회논문지 Vol.21 No.4

2G HTS wire with high engineering current density is desired for applications where compact, high power density superconducting equipment is important. We have succeeded in enhancing engineering current density of commercial SuperOx 2G HTS wire based on GdBCO by increasing the HTS layer thickness without fast degradation of the HTS film microstructure. This was possible after improving the temperature uniformity along the HTS film deposition zone. In particular, the wire engineering current density was increased from 700-770 A/mm2 (for a 65 µm-thick wire without stabilisation) or 430-480 A/mm2 (for a 105 µm-thick stabilised wire) at the beginning of this study to almost 1200 A/mm2 (for a 67 µm-thick wire without stabilisation) or 770 A/mm2 (for a 107 µm-thick stabilised wire) at completion of this study.

A study of nerve agent model organophosphonate binding with manganese-A₂B-corrole and -A₂B₂-porphyrin systems

Kim, K.,Kim, I.,Maiti, N.,Kwon, S.J.,Bucella, D.,Egorova, O.A.,Lee, Y.S.,Kwak, J.,Churchill, D.G. Pergamon Press 2009 Polyhedron Vol.28 No.12

Herein the synthesis and binding studies of novel trans-A<SUB>2</SUB>B-corrole and trans-A<SUB>2</SUB>B<SUB>2</SUB>-porphyrin derivatives are presented in comparing manganese(III)-organophosphonate (OP) binding (e.g., M<SUP>n+</SUP>←O?PR(OR)<SUB>2</SUB>) capabilities. H<SUB>3</SUB>(PFP-VC) [PFP-VC=5,15-di(pentafluorophenyl)-10-(3-vinylphenyl)corrolate] was synthesized by way of literature procedures and was characterized by a variety of 2-D NMR spectroscopic techniques and single-crystal X-ray diffraction. These compounds represent the first example of 3-vinyl-phenyl-containing meso-substituted corroles or porphyrins. Mn(PFP-VC) (3) was treated separately with (CH<SUB>3</SUB>CH<SUB>2</SUB>O)<SUB>2</SUB>P?O(C<SUB>3</SUB>H<SUB>6</SUB>NMe<SUB>2</SUB>), (C<SUB>4</SUB>H<SUB>9</SUB>O)<SUB>2</SUB>P?O(Me), (C<SUB>2</SUB>H<SUB>5</SUB>O)<SUB>2</SUB>P?O(CH<SUB>2</SUB>COCH<SUB>3</SUB>), (CH<SUB>3</SUB>CH<SUB>2</SUB>O)<SUB>2</SUB>P?O(Me), to give 1:1 adducts, as determined by UV-Vis spectroscopy (Job Plot), giving a red shift; Ph<SUB>3</SUB>P?O, was also found to bind, but very weakly. The trans-A<SUB>2</SUB>B<SUB>2</SUB>-porphyrin analogue Mn(PFP-VP) (4) was also prepared by way of a literature procedure; related binding studies gave 1:1 organophosphonate-Mn(PFP-VP) adducts (Job Plot). A clean blue shift occurred for the Mn-porphyrins at higher organophosphonate loadings (K<SUB>a</SUB> values: 6.7 (0.9)-11.9 (0.4)M<SUP>-1</SUP>). DFT geometry optimizations of O?P(OMe)<SUB>2</SUB>Me binding and formal Mn-O or P-O cleavage products in the unsubstituted neutral Mn-corrolato and -porphyrinato systems with a range of metal-based spin states revealed greatest stability in formal phosphoryl oxygen binding (energies: 11-13kcal/mol) for the Mn-corrole (singlet); the Mn-porphyrin (sextet) was also quite stable.

초등학교 축구선수의 성격타입(A/B), 정신력과 운동몰입의 구조적 관계

김인수(Kim In-Soo),최정아(Choi Jeang-a) 한국체육교육학회 2016 한국체육교육학회지 Vol.20 No.4

이 연구는 초등학교 축구선수의 A/B 타입 성격과 정신력, 운동몰입 간에 어떤 인과관계가 있는지를 밝힘으로써 초등학교 축구선수의 경기력 향상에 도움을 주고자 수행되었다. 이러한 연구목적을 달성하기 위해 G광역시와 J도에 소재한 초등학교 축구선수로 등록된 236명과 중학교 축구 선수 110명을 대상으로 A/B 타입 성격척도, 정신력 척도, 운동몰입척도를 사용하여 집단 간 t-test 및 공변량 구조분석을 실시하였다. 변인 간의 구조적 관계분석을 위해 A/B 타입 성격을 외생변인으로 하고, 정신력과 운동몰입을 내생변인으로 한 구조모델을 설정하고 검증하였으며 그 결과 첫째, A/B 타입 성격 간 비교에서A 타입 성격소유자가 B타입 성격소유자에 비해 정신력과 운동몰입이 높은 것으로 나타났다. 입상경력유무집단 간 비교에서 입상경력이 있는 선수는 그렇지 못한 선수에 비해 A 타입 성격, 정신력, 운동몰입이 높았다. 초등학교 축구선수와 중학교 축구선수 간 비교에서는 성격타입, 정신력, 운동몰입에 차이가 없었다. 둘째, 변인 간 상관분석을 실기한 결과 A/B 타입 성격, 정신력, 운동몰입 간에는 서로 유의한(p<.01) 상관이 있었다. 셋째, 변인 간 구조관계를 분석한 결과 완전매개모형이 적합한 것으로 나타났고, A/B 타입 성격을 외생변인으로 하고 정신력과 운동몰입을 내생변인으로 한 구조모형은 이론모델로서 양호한 것으로 나타났으며(χ2=20.13, df=7, Q=2.88, RMR=.01, GFI=.97, TLI=.94, NFI=.96, CFI=.97, RMSEA=.08) 세부 구조경로에서는 A/B타입 성격 → 정신력, 정신력 → 운동몰입의 경로가 유의한(p<.01) 것으로 나타났다. 이를 요약하면 초등학교 축구선수의 경우 A타입 성격 성향이 강할수록 정신력과 운동몰입 수준이 높으며 지방대회 3위 이상의 입상경력을 가진 선수는 그렇지 않는 선수에 비해 A 타입 성격 성향이 강하고, 정신력과 운동몰입 수준이 높다. 또한, A/B 성격 성향은 정신력과 밀접한 관련이 있으며 정신력은 운동몰입과 인과관계가 있는 것으로 나타나 초등학교 축구선수의 운동몰입 수준을 증가시키기 위해서는 정신력의 강화가 필요함을 제시해 주고 있다. Purpose: The Purpose of this study was to define structural relation among A/B type behavior pattern, mental toughness, and sport commitment of elementary school soccer players. Methods: This study set up a structural relation model which was composed of exogenous variables as A/B type behavior pattern and endogenous variables were mental toughness, and sport commitment of soccer players. The participants were 236 elementary school and 110 middle school soccer players who lived in G city and J province. This study used A/B type behavior pattern scale, Mental toughness scale and commitment scale. Results: In analysis of t-test, A type players show higher mental toughness and sport commitment than those of B type. The players who had experienced more 3rd place in province soccer competition show higher A type behavior pattern, mental toughness, and behavioral commitment than those of the others. There were no differences between elementary school players and middle school players in A/B type behavior pattern, mental toughness and sport commitment. In analysis of correlation, there were significant relations between A/B type behavior pattern, mental toughness and sport commitment. In analysis structure equation, this model can be used as theoretical model because general indexes were proved(χ2=20.13, df=7, Q=2.88, RMR=.01, GFI=.97, TLI=.94, NFI=.96, CFI=.97, RMSEA=.08). In analysis details index, there were significant paths of A/B type behavior pattern → mental toughness, mental toughness → sport commitment. Conclusion: In this study define there are causal relationships among A/B type behavior pattern, mental toughness and sport commitment. To approve sport commitment of elementary school soccer players, players kept up A type behavior pattern and make strong mental toughness.

On the edge -to -vertex detour number of a graph

A.P. Santhakumaran 장전수학회 2014 Advanced Studies in Contemporary Mathematics Vol.24 No.3

For two vertices u and v in a graph G=(V,E), The detour distance D(u,v) s the length of a longest, u-v path in G. A u-v path of length D(u,v) is called a u-v detour. For subsets A and B of V, the detour distance D(A,B) is defined as D(A,B)=(formula). A u-v path of length D(A,B) is called an A-B detour joining the sets A, B⊆V where u∈B. A vertex x is said to lie on an A-B detour is a vertex of A-B detour. A set S⊆E is called an detour joining a pair of edges of S. The edge-to-vertex detour number dn2(G) OF G is the minimum order of its edge-to-vertex detour sets and any edge-to-vertex detour set of order dn2(G) is an edge-to-vertex detour basis of G. Graphs G of size q for which dn2(G) = q or dn2(G) = q-1 or dn2(G) = q-2 are characterized.