http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Aziz, Md. Abdul,Shanmugam, Sangaraju Royal Society of Chemistry 2017 Journal of Materials Chemistry A Vol.5 No.32
<▼1><P>An ultra-high ion-selective SPAEK/ZrNT composite membrane is developed and exhibits an improved VRB self-discharge time compared with SPAEK and Nafion-212 membranes.</P></▼1><▼2><P>An ultra-high ion-selective membrane composed of an aromatic block copolymer sulfonated poly(arylene ether ketone) (SPAEK) and ZrO2 nanotubes (ZrNTs) is designed and fabricated <I>via</I> a solution-casting method. The composite membrane showed high proton conductivity and a reduced VO<SUP>2+</SUP> crossover rate compared with a pristine SPAEK membrane. The SPAEK/ZrNT composite membrane exhibits a high proton conductivity and superior ion selectivity by reducing the crossover of vanadium ions during the long-term operation of an all vanadium redox flow battery (VRB). The VO<SUP>2+</SUP> permeability rate of SPAEK/ZrNT is 0.09 × 10<SUP>−7</SUP> cm<SUP>2</SUP> min<SUP>−1</SUP>, which is 11- and 37-fold lower compared to that of the pristine SPAEK (1.0 × 10<SUP>−7</SUP> cm<SUP>2</SUP> min<SUP>−1</SUP>) and Nafion-212 (3.3 × 10<SUP>−7</SUP> cm<SUP>2</SUP> min<SUP>−1</SUP>) membranes, respectively. The VRB assembled with a SPAEK/ZrNT composite membrane showed a significantly lower self-discharge rate, retaining an open circuit voltage of 1.3 V for 500 h, compared to the pristine SPAEK (126 h) and Nafion-212 (29 h) membranes, indicating the superior ion selectivity of the composite membrane (6.6 × 10<SUP>6</SUP> S min cm<SUP>−3</SUP>), which is an 11- and 41-fold higher ion selectivity compared to that of the pristine SPAEK and Nafion-212 membranes, respectively. The SPAEK/ZrNT composite membrane exhibits a higher coulombic efficiency (CE, 99.86%) and energy efficiency (EE, 83.82%) at 40 mA cm<SUP>−2</SUP>, as compared to the pristine SPAEK (CE, 97.76% and EE, 81.56%) and Nafion-212 (CE, 89.65% and EE, 75.53%) membranes. The capacity retention of the SPAEK/ZrNT composite membrane is 93%, which is much higher than that of the SPAEK (72%) and Nafion-212 (38%) membranes after 100 VRB cycles. Moreover, the VRB with the SPAEK/ZrNT composite membrane maintains a stable cycling performance at different current densities, indicating the great potential of this separator as a substitute for the commercial Nafion membrane widely used in VRBs.</P></▼2>
Md. Abdul Aziz,양해식 대한화학회 2007 Bulletin of the Korean Chemical Society Vol.28 No.7
We have developed an electrochemical immunosensor that combines the electrocatalytic property of carbon nanotube and the low background current of indium tin oxide (ITO) electrode. A partial monolayer of carboxylated single-walled carbon nanotube (CCNT) is covalently formed on an ITO electrode modified with amine-terminated phosphonic acid. Nonspecifically adsorbed avidin on the hydrophobic sidewalls of CCNT is used to immobilize biotinylated antibody and to reduce the nonspecific binding to CCNT. The biotinylated antimouse IgG bound on avidin and the antimouse IgG conjugated with alkaline phosphatase (ALP) sandwiches a target mouse IgG. ALP catalyzes the conversion of p-aminophenyl phosphate monohydrate into p-aminophenol, which is electrocatalytically oxidized to p-quinone imine on CCNT surface. Moderate electrocatalytic electrode obtained with the combination of CCNT and ITO allows low detection limit (0.1 ng/mL).
Aziz, Md.Abdul,Yang, Hae-Sik Korean Chemical Society 2007 Bulletin of the Korean Chemical Society Vol.28 No.7
We have developed an electrochemical immunosensor that combines the electrocatalytic property of carbon nanotube and the low background current of indium tin oxide (ITO) electrode. A partial monolayer of carboxylated single-walled carbon nanotube (CCNT) is covalently formed on an ITO electrode modified with amine-terminated phosphonic acid. Nonspecifically adsorbed avidin on the hydrophobic sidewalls of CCNT is used to immobilize biotinylated antibody and to reduce the nonspecific binding to CCNT. The biotinylated antimouse IgG bound on avidin and the antimouse IgG conjugated with alkaline phosphatase (ALP) sandwiches a target mouse IgG. ALP catalyzes the conversion of p-aminophenyl phosphate monohydrate into p-aminophenol, which is electrocatalytically oxidized to p-quinone imine on CCNT surface. Moderate electrocatalytic electrode obtained with the combination of CCNT and ITO allows low detection limit (0.1 ng/ mL).
Aziz, Md. Abdul,Shanmugam, Sangaraju Elsevier 2017 Journal of Power Sources Vol.337 No.-
<P><B>Abstract</B></P> <P>A high-performance composite membrane for vanadium redox flow battery (VRB) consisting of ZrO<SUB>2</SUB> nanotubes (ZrNT) and perfluorosulfonic acid (Nafion) was fabricated. The VRB operated with a composite (Nafion-ZrNT) membrane showed the improved ion-selectivity (ratio of proton conductivity to permeability), low self-discharge rate, high discharge capacity and high energy efficiency in comparison with a pristine commercial Nafion-117 membrane. The incorporation of zirconium oxide nanotubes in the Nafion matrix exhibits high proton conductivity (95.2 mS cm<SUP>−1</SUP>) and high oxidative stability (99.9%). The Nafion-ZrNT composite membrane exhibited low vanadium ion permeability (3.2 × 10<SUP>−9</SUP> cm<SUP>2</SUP> min<SUP>−1</SUP>) and superior ion selectivity (2.95 × 10<SUP>7</SUP> S min cm<SUP>−3</SUP>). The VRB constructed with a Nafion-ZrNT composite membrane has lower self-discharge rate maintaining an open-circuit voltage of 1.3 V for 330 h relative to a pristine Nafion membrane (29 h). The discharge capacity of Nafion-ZrNT membrane (987 mAh) was 3.5-times higher than Nafion-117 membrane (280 mAh) after 100 charge-discharge cycles. These superior properties resulted in higher coulombic and voltage efficiencies with Nafion-ZrNT membranes compared to VRB with Nafion-117 membrane at a 40 mA cm<SUP>−2</SUP> current density.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The Nafion-ZrNT composite membrane was successfully fabricated. </LI> <LI> Nafion-ZrNT membrane shows low vanadium-ion crossover thus superior ion selectivity. </LI> <LI> VRB showed low self-discharge rate for Nafion-ZrNT composite membrane than Nafion-117. </LI> <LI> Nafion-ZrNT exhibits high discharge capacity and efficiency compared with Nafion-117. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>
Aziz, Md. Abdul,Jo, Kyungmin,Qaium, Md. Abdul,Huh, Chan-Hwa,Hong, In Seok,Yang, Haesik WILEY-VCH Verlag 2009 Electroanalysis Vol.21 No.19
<P>We report a versatile platform for highly sensitive alkaline phosphatase (ALP)-based electrochemical biosensors that uses an avidin-modified indium tin oxide (ITO) electrode as a sensing electrode and 1-naphthyl phosphate (NPP) as an ALP substrate. Almost no electrocatalytic activity of NPP and good electrocatalytic activity of 1-naphthol (ALP product) on the ITO electrodes allow a high signal-to-background ratio. The effective surface covering of avidin on the ITO electrodes allows very low levels of nonspecific binding of proteins to the sensing electrodes. The platform technology is used to detect mouse IgG with a detection limit of 1.0 pg/mL.</P>
Evaluation of Noise Environment and Noise Mapping with ArcGIS in Chittagong City, Bangladesh
Md. Abdul Aziz,Ahasanul Karim,Md. Mehedi Hassan Masum,Kazi Kader Newaz 대한환경공학회 2021 대한환경공학회지 Vol.43 No.4
Objectives : Noise pollution in Chittagong City of Bangladesh is a big concern because of huge population growth and urbanization. The objective of the study was to evaluate and mapping the noise levels in twelve locations of this city at different periods. Methods : Noise level data were collected at various locations by a precision grade sound level meter and the noise pollution parameters (Lmin, LAeq,2h and Lmax) were calculated. Furthermore, the noise pollution maps of Chittagong City were developed using geographical information system to address the locations which are prone to the environmental hazards. Results and discussion : The study revealed that the average noise levels were 64.6, 76.9, and 75.5 ㏈(A) for residential, commercial and silence zones, respectively. The interpolated noise maps showed that noise environment of this city was unsatisfactory, especially, in the areas of New Market, Nasirabad, and Bawa School & College were exposed to high noise pollutions. The afternoon and evening periods were experiencing higher noise pollution in the commercial and silence zones than the morning period of the day. Conclusions : The study suggests that the noise levels are above the acceptable limit and hence urgent measures should be taken into consideration to control the level of noise pollution in the city.
Aziz, Md. Abdul,Selvaraju, Thangavelu,Yang, Haesik WILEY-VCH Verlag 2007 Electroanalysis Vol.19 No.14
<P>The electrochemical, selective determination of catechol (CT) in the presence of hydroquinone (HQ) is not readily achieved, because the formal potentials of two phenolic compounds are very close. Here, we have developed a simple electrochemical method for the selective determination of CT by using bare indium tin oxide electrodes and employing CT redox cycling by hydrazine. The cyclic voltammetry of CT and HQ was investigated in Tris buffer (pH 9.0), phosphate buffered saline buffer (pH 7.4), and acetate buffer (pH 4.5). Especially in Tris buffer, the anodic peak potential of CT is much lower than that of HQ, resulting in a large difference between two peak potentials (ca. 0.4 V). The difference allows the selective determination of CT in the presence of excess HQ. The anodic current of CT is amplified using CT redox cycling by hydrazine, which also helps to stabilize CT and HQ in Tris buffer for several hours. The detection limits of CT in Tris buffer containing 0.1 mM HQ are 1 μM and 10 μM in the presence and absence of hydrazine, respectively.</P>