scholarly journals Electrochemical evidence of sulfinic acid derivative as an intermediate in the reduction of aromatic sulfonyl chloride in an aprotic medium

2005 ◽  
Vol 30 (3) ◽  
pp. 57-61 ◽  
Author(s):  
A. C .D. Angelo ◽  
S. M. A. Jorge ◽  
N. R. Stradiotto

The electrochemical reduction of p-nitrobenzenesulfonyl chloride (NBSCl) in dimethylsulfoxide (DMSO) solution is used here as a model to investigate the role of sulfinic acid derivative in this compound's global reduction process. Cyclic voltammetric experiments reveal the production of sulfinic acid derivative, which is important in chemical reactions involving the original compound and other intermediates. This paper also discusses the probable mechanisms of the reduction.

Author(s):  
David R. Veblen

Extended defects and interfaces control many processes in rock-forming minerals, from chemical reactions to rock deformation. In many cases, it is not the average structure of a defect or interface that is most important, but rather the structure of defect terminations or offsets in an interface. One of the major thrusts of high-resolution electron microscopy in the earth sciences has been to identify the role of defect fine structures in reactions and to determine the structures of such features. This paper will review studies using HREM and image simulations to determine the structures of defects in silicate and oxide minerals and present several examples of the role of defects in mineral chemical reactions. In some cases, the geological occurrence can be used to constrain the diffusional properties of defects.The simplest reactions in minerals involve exsolution (precipitation) of one mineral from another with a similar crystal structure, and pyroxenes (single-chain silicates) provide a good example. Although conventional TEM studies have led to a basic understanding of this sort of phase separation in pyroxenes via spinodal decomposition or nucleation and growth, HREM has provided a much more detailed appreciation of the processes involved.


2020 ◽  
Vol 40 ◽  
pp. 156-170 ◽  
Author(s):  
Ping Shao ◽  
Luocai Yi ◽  
Shumei Chen ◽  
Tianhua Zhou ◽  
Jian Zhang

2010 ◽  
Vol 645-648 ◽  
pp. 271-276 ◽  
Author(s):  
Robert E. Stahlbush ◽  
Rachael L. Myers-Ward ◽  
Brenda L. VanMil ◽  
D. Kurt Gaskill ◽  
Charles R. Eddy

The recently developed technique of UVPL imaging has been used to track the path of basal plane dislocations (BPDs) in SiC epitaxial layers. The glide of BPDs during epitaxial growth has been observed and the role of this glide in forming half-loop arrays has been examined. The ability to track the path of BPDs through the epitaxy has made it possible to develop a BPD reduction process for epitaxy grown on 8° offcut wafers, which uses an in situ growth interrupt and has achieved a BPD reduction of > 98%. The images also provide insight into the strong BPD reduction that typically occurs in epitaxy grown on 4° offcut wafers.


2021 ◽  
pp. 2151037
Author(s):  
Yu Meng ◽  
Qing Zhong ◽  
Arzugul Muslim

Because −NH2 and −NH− in poly-[Formula: see text]-phenylenediamine (P[Formula: see text]PD) can interact strongly with the empty orbitals of Cu to show unique electrochemical activity, P[Formula: see text]PD is suitable for the removal of Cu[Formula: see text] by electrochemical oxidation–reduction process. In this study, with P[Formula: see text]PD and its carbon dot composite (CDs/P[Formula: see text]PD) as working electrodes, the electrochemical reduction and removal of Cu[Formula: see text] in the aqueous solution were carried out with the potentiostatic method. According to effects of voltage, pH of the solution, initial concentration of Cu[Formula: see text], and electrochemical reduction time on the Cu[Formula: see text] removal, the Cu[Formula: see text] removal ratios of P[Formula: see text]PD and CDs/P[Formula: see text]PD were up to 64.69% and 73.34%, respectively, at −0.2 V and the optimal pH. Additionally, results showed that these processes were in line with the quasi-first order kinetic model. Both P[Formula: see text]PD and CDs/P[Formula: see text]PD showed good reproducibility in six cycles. After five times of repeated usage, the regeneration efficiencies of P[Formula: see text]PD and CDs/P[Formula: see text]PD dropped to 77.04% and 79.36%, respectively.


Author(s):  
Mengran Li ◽  
Mohamed Nazmi Idros ◽  
Yuming Wu ◽  
Thomas Burdyny ◽  
Sahil Garg ◽  
...  

The electrochemical reduction of carbon dioxide (CO2RR) requires access to ample gaseous CO2 and liquid water to fuel reactions at high current densities for industrial-scale. Substantial improvement of the CO2RR...


2004 ◽  
Vol 188 (3) ◽  
pp. 288-293 ◽  
Author(s):  
Faruk O. Aytekin ◽  
Koray Tekin ◽  
Burhan Kabay ◽  
Ergun Erdem ◽  
Halil Erbis ◽  
...  

Jurnal Socius ◽  
2016 ◽  
Vol 1 (1) ◽  
Author(s):  
Roghyati Roghyati

Nonformal education in Paket A, B, and C is one of the civil right for the citizens to be easily accessible and this is held by PKBM. The research has to objective to know the characteristics of learning community and tutor, the role of PKBM Barito in providing facility and equipment for learning, social learning process of Kejar Paket B celebrated by PKBM Barito. The research uses the qualitative method. The source of data is chosen purposively, and the data collection uses observation, interview, and documentation. The research instruments are interview guide, observation sheet, and documentation. Data analysis by data reduction process, data display, and verification. The research finding say that (1) the characteristics of learning community are in variation whether in age, marital status, profession, education background, motivation, skill, the interestedness to subject, expectation after graduation, and problem in their lives. Whereas characteristics of tutor could be seen from the education level, professional competence, and pedagogic competence; (2) the role of PKBM does not work maximally whether in recruiting community learning, providing facility and equipment for learning celebration, and learning evaluation; however PKBM has the role in recruiting tutor and celebration fund; (3) the learning process of social science for Paket B has fulfilled minimal standar involving preparation, implementation, and evaluation but does not work maximally in learning for the mature learners.Key words: social science learning, Kejar Paket, PKBM role, learning community, tutor.


2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Оrest Kuntyi ◽  
Galyna Zozulya ◽  
Andriy Kytsya

The main features of the “green” synthesis of metallic nanoparticles (MNPs) by the sonoelectrochemical methods are manufacturability, environmental friendliness, and the possibility of controlling the geometry of the forming particles. The electrochemical reduction technique allows efficiently designing the metal nanoparticles and provides the control of the content of components of bimetallic nanoparticles, as well as minimizing the number of precursors in working solutions. Due to the generation of turbulence, microjets, and shock waves, ultrasound increases mass transfer and formation of radicals in aqueous solutions and, accordingly, accelerates the processes of nucleation and growth of MNPs. Therefore, this hybrid method, which combines electrolysis and ultrasound, has attracted the interest of researchers in the last two decades as one of the most promising techniques. The present work presents a short analysis of the reference literature on sonoelectrochemical synthesis of metallic and bimetallic nanoparticles. The main factors influencing the geometry of nanoparticles and their size distribution are analyzed. The use of pulsed ultrasound and pulsed current supply during sonoelectrochemical synthesis is especially effective in designing MNPs. Emphasis is placed on the role of surfactants in the formation of MNPs and sacrificial anodes in providing the algorithm: “anodic dissolution-electrochemical reduction of metal-nucleation and formation of МNPs.” It is noted that ultrasound allows synthesizing the MNPs and M1M2NPs during the galvanic replacement, and an analogy of the formation of nanoparticles by sonogalvanic replacement and sonoelectrochemical method is shown.


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