The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Katsuaki Shimazu - One of the best experts on this subject based on the ideXlab platform.
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Succinimidyl Ester Surface Chemistry: Implications of the Competition between Aminolysis and Hydrolysis on Covalent Protein Immobilization
2016Co-Authors: Marc D Porter, Makoto Takahashi, Katsuaki ShimazuAbstract:ABSTRACT: N-Hydroxysuccinimide (NHS) ester terminal groups are commonly used to covalently couple amine-containing biomolecules (e.g., proteins and peptides) to surfaces via amide linkages. This one-step aminolysis is often performed in buffered aqueous solutions near physiological pH (pH 6 to pH 9). Under these conditions, the hydrolysis of the ester group competes with the amidization process, potentially degrading the efficiency of the coupling chemistry. The work herein examines the efficiency of covalent protein immobiliza-tion in borate buffer (50 mM, pH 8.50) using the thiolate monolayer formed by the chemisorption of dithiobis (succinimidyl propionate) (DSP) on gold films. The structure and reactivity of these adlayers are assessed via infrared spectroscopy (IR), X-ray photoelectron spectroscopy (XPS), electrochemical reductive desorption, and contact angle measurements. The hydrolysis of the DSP-based monolayer is proposed to follow a reaction mechanism with an initial nucleation step, in contrast to a simple pseudo first-order reaction rate law for the entire reaction, indicating a strong dependence of th
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succinimidyl ester surface chemistry implications of the competition between aminolysis and hydrolysis on covalent protein immobilization
Langmuir, 2014Co-Authors: Nicholas A Owens, Ronald D Wampler, Yixin Ying, Jennifer H Granger, Marc D Porter, Makoto Takahashi, Katsuaki ShimazuAbstract:N-Hydroxysuccinimide (NHS) ester terminal groups are commonly used to covalently couple amine-containing biomolecules (e.g., proteins and peptides) to surfaces via amide linkages. This one-step aminolysis is often performed in buffered aqueous solutions near physiological pH (pH 6 to pH 9). Under these conditions, the hydrolysis of the ester group competes with the amidization process, potentially degrading the efficiency of the coupling chemistry. The work herein examines the efficiency of covalent protein immobilization in borate buffer (50 mM, pH 8.50) using the thiolate monolayer formed by the chemisorption of dithiobis (succinimidyl propionate) (DSP) on gold films. The structure and reactivity of these adlayers are assessed via infrared spectroscopy (IR), X-ray photoelectron spectroscopy (XPS), electrochemical reductive desorption, and contact angle measurements. The hydrolysis of the DSP-based monolayer is proposed to follow a reaction mechanism with an initial nucleation step, in contrast to a simp...
Ibrahim F Nassar - One of the best experts on this subject based on the ideXlab platform.
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corrosion inhibition of tubing steel during Acidization of oil and gas wells
Electrochimica Acta, 2008Co-Authors: M A Migahed, Ibrahim F NassarAbstract:Acidization is an oil reservoir stimulation technique for increasing well productivity. Hydrochloric acid, HCl, is used in oil and gas production to stimulate the formation. The acid treatment occurs through steel tubes. The process requires a high degree of corrosion inhibition. The present study deals with the evaluation of the effectiveness of the new synthesized compound namely; 6-methyl-5-[m-nitro styryl]-3-mercapto-1,2,4-triazine as corrosion inhibitor for mild steel in 12% HCl solution at 50 °C using various chemical and electrochemical techniques. The results showed that anodic dissolution of mild steel was remarkably decreased. The strong adsorption ability of this new synthesized compound can be attributed to the presence of multiple adsorption centers of nitrogen as well as π-donor moieties.
Mahendra Yadav - One of the best experts on this subject based on the ideXlab platform.
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corrosion inhibition of tubing steel during Acidization of oil and gas wells
Journal of Petroleum Engineering, 2013Co-Authors: Mahendra Yadav, Sanjay Kumar, P N YadavAbstract:Acidization is an oil reservoir stimulation technique for increasing oil well productivity. Hydrochloric acid is used in oil and gas production to stimulate the formation. The acid treatment occurs through N80 steel tubes. The process requires a high degree of corrosion inhibition of tubing material (N80 steel). In the present investigation effect of synthesized amino acid compounds, namely, acetamidoleucine (AAL) and benzamidoleucine (BAL) as corrosion inhibitors for N80 steel in 15% HCl solution was studied by polarization, AC impedance (EIS), and weight loss measurements. It was found that both the inhibitors were effective inhibitors and their inhibition efficiency was significantly increased with increasing concentration of inhibitors. Polarization curves revealed that the studied inhibitors represent mixed type inhibitors. AC impedance studies revealed that charge transfer resistance increases and double layer capacitance decreases in presence of inhibitors. Adsorption of inhibitors at the surface of N80 steel was found to obey Langmuir isotherm.
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development of ecofriendly corrosion inhibitors for application in Acidization of petroleum oil well
Journal of Chemistry, 2013Co-Authors: Mahendra Yadav, Sumit Kumar, P N YadavAbstract:In the present investigation the protective ability of 1-(2-aminoethyl)-2-octadecylimidazoline (AEODI) and 1-(2-octadecylamidoethyl)-2-octadecylimidazoline (ODAEODI) as corrosion inhibitors for N80 steel in 15% hydrochloric acid has been studied, which may find application as ecofriendly corrosion inhibitors in acidizing processes in petroleum industry. Different concentration of synthesized inhibitors AEODI and ODAEODI was added to test solution (15% HCl), and corrosion inhibition of N80 steel was tested by weight loss, potentiodynamic polarization, and AC impedance measurements. Influence of temperature (298 to 323 K) on the inhibition behaviour was studied. Surface studies were performed by using SEM. It was found that both the inhibitors were effective inhibitors, and their inhibition efficiency was significantly increased with increasing their concentration. Polarization curves revealed that the used inhibitors represent mixed-type inhibitors. The adsorption of used inhibitors led to a reduction in the double-layer capacitance and an increase in the charge transfer resistance. The adsorption of used compounds was found to obey Langmuir isotherm. The adsorption of the corrosion inhibitors at the surface of N80 steel is the root cause of corrosion inhibition.
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development of corrosion inhibitors used in Acidization ofpetroleum oil well
Der Chemica Sinica, 2012Co-Authors: Mahendra Yadav, Debasis Behera, Usha SharmaAbstract:An important method of protecting metallic materials against deterioration due to corrosion is by the use of corrosion inhibitors. In the present investigation, corrosion inhibition study of two amino acid compounds, 2- amino-N-decyl-3-phenylpropionamide (Inh I) and 2-amino-N-decylpropionamide (Inh II) have been performed for oil-well tubular steel (N-80) in 15% HCl using weight loss, electrochemical polarization and SEM techniques. The inhibition efficiencies of the inhibitors follow the sequence, Inh I > Inh II. The results showed that inhibition efficiency of all inhibitors increased with increase in inhibitors concentration. Both inhibitors act as mixed inhibitors and obey the Langmuir adsorption isotherm. Corrosion inhibition mechanism followed the adsorption phenomenon
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corrosion inhibitors for Acidization of petroleum oil well
Asian Journal of Research in Chemistry, 2011Co-Authors: Mahendra Yadav, Usha SharmaAbstract:An important method of protecting metallic materials against deterioration due to corrosion is by the use of corrosion inhibitors. In the present investigation, corrosion inhibition study of two imidazoline derivatives, 1-(2-hydroxy ethyl)-2-methylimidazoline (Inh I) and 1-(2-hydroxyethyl)-2-decylimidazoline (Inh II)) have been performed for oil-well tubular steel (N-80) in 15% HCl using weight loss, electrochemical polarization and SEM techniques. The inhibition efficiencies of the inhibitors follow the sequence, Inh II > Inh I. The results showed that inhibition efficiency of both the inhibitors increased with increase in inhibitors concentration. Both inhibitors act as mixed inhibitors and obey the Langmuir adsorption isotherm. Corrosion inhibition mechanism take place through adsorption phenomenon.
Nicholas A Owens - One of the best experts on this subject based on the ideXlab platform.
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succinimidyl ester surface chemistry implications of the competition between aminolysis and hydrolysis on covalent protein immobilization
Langmuir, 2014Co-Authors: Nicholas A Owens, Ronald D Wampler, Yixin Ying, Jennifer H Granger, Marc D Porter, Makoto Takahashi, Katsuaki ShimazuAbstract:N-Hydroxysuccinimide (NHS) ester terminal groups are commonly used to covalently couple amine-containing biomolecules (e.g., proteins and peptides) to surfaces via amide linkages. This one-step aminolysis is often performed in buffered aqueous solutions near physiological pH (pH 6 to pH 9). Under these conditions, the hydrolysis of the ester group competes with the amidization process, potentially degrading the efficiency of the coupling chemistry. The work herein examines the efficiency of covalent protein immobilization in borate buffer (50 mM, pH 8.50) using the thiolate monolayer formed by the chemisorption of dithiobis (succinimidyl propionate) (DSP) on gold films. The structure and reactivity of these adlayers are assessed via infrared spectroscopy (IR), X-ray photoelectron spectroscopy (XPS), electrochemical reductive desorption, and contact angle measurements. The hydrolysis of the DSP-based monolayer is proposed to follow a reaction mechanism with an initial nucleation step, in contrast to a simp...
Jisheng Kou - One of the best experts on this subject based on the ideXlab platform.
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thermodynamically consistent darcy brinkman forchheimer framework in matrix Acidization
Oil & Gas Science and Technology – Revue d’IFP Energies nouvelles, 2021Co-Authors: Jisheng Kou, Shuyu SunAbstract:Matrix Acidization is an important technique used to enhance oil production at the tertiary recovery stage, but its numerical simulation has never been verified. From one of the earliest models, i.e., the two-scale model (Darcy framework), the Darcy–Brinkman–Forchheimer (DBF) framework is developed by adding the Brinkman term and Forchheimer term to the momentum conservation equation. However, in the momentum conservation equation of the DBF framework, porosity is placed outside of the time derivation term, which prevents a good description of the change in porosity. Thus, this work changes the expression so that the modified momentum conservation equation can satisfy Newton’s second law. This modified framework is called the improved DBF framework. Furthermore, based on the improved DBF framework, a thermal DBF framework is given by introducing an energy balance equation to the improved DBF framework. Both of these frameworks are verified by former works through numerical experiments and chemical experiments in labs. Parallelization to the complicated framework codes is also realized, and good scalability can be achieved.
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a decoupled scheme to solve the mass and momentum conservation equations of the improved darcy brinkman forchheimer framework in matrix Acidization
arXiv: Computational Physics, 2020Co-Authors: Jisheng Kou, Shuyu Sun, Yilin XiaAbstract:Matrix Acidization simulation is a challenging task in the study of flows in porous media, due to the changing porosity in the procedure. The improved DBF framework is one model to do this simulation, and its numerical scheme discretises the mass and momentum conservation equations together to form a pressure-velocity linear system. However, this linear system can only be solved by direct solvers to solve for pressure and velocity simultaneously, since zeros appear in the diagonal of the coefficient matrix. Considering the large-scale attribute of matrix Acidization simulation, the solving time of direct solvers is not intolerant. Thus, a decoupled scheme is proposed in this work to decouple the coupled pressure-velocity linear system into two independent linear systems: one is to solve for pressure, and the other one is to solve for velocity. Both of the new linear systems can be solved by parallel and iterative solvers, which guarantees the large-scale simulation can be finished in a reasonable time period. A numerical experiment is carried out to demonstrate the correctness of the decoupled scheme and its higher computing efficiency.
