scholarly journals Theoretical aspects of dipolar interactions and their appearance in first-order reversal curves of thermally activated single-domain particles

2006 ◽  
Vol 111 (B12) ◽  
pp. n/a-n/a ◽  
Author(s):  
R. Egli
2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Juanjuan Zhao ◽  
Yujiao Sun ◽  
Fachao Wu ◽  
Minjian Shi ◽  
Xurui Liu

Antibiotic residues and antibiotic resistance genes (ARGs) pose a great threat to public health and food security via the horizontal transfer in the food production chain. Oxidative degradation of amoxicillin (AMO) in aqueous solution by thermally activated persulfate (TAP) was investigated. The AMO degradation followed a pseudo-first-order kinetic model at all tested conditions. The pseudo-first-order rate constants of AMO degradation well-fitted the Arrhenius equation when the reaction temperature ranged from 35°C to 60°C, with the apparent activate energy of 126.9 kJ·mol−1. High reaction temperature, high initial persulfate concentration, low pH, high Cl− concentration, and humic acid (HA) concentration increased the AMO degradation efficiency. The EPR test demonstrated that both ·OH and SO4·− were generated in the TAP system, and the radical scavenging test identified that the predominant reactive radical species were SO4·− in aqueous solution without adjusting the solution pH. In groundwater and drinking water, AMO degradation suggested that TAP could be a reliable technology for water remediation contaminated by AMO in practice.


2014 ◽  
Vol 675-677 ◽  
pp. 547-550
Author(s):  
Jun Jie Yue ◽  
Xiao Qiao Zhu ◽  
Yu Ting Wang ◽  
Yu Qin Zhang ◽  
Li Zhao ◽  
...  

In situ chemical oxidation with persulfate (PS) anion (S2O82-) is a viable technique for remediation of groundwater contaminants such as trichloroethylene (TCE). This laboratory study investigated the use of the oxidant sodium PS for the chemical oxidation of TCE at different conditions to determine the influence of temperature, pH, and the PS/TCE molar ratio. Experiments revealed that higher temperatures, lower pH, and higher PS/TCE molar ratios were to the benefit of TCE oxidation by PS. By investigating the reaction kinetics, the degradations of contaminant can be described by use of pseudo-first-order reaction. At the temperatures ranging from 25°C to 40°C, the activation energy for the degradation of TCE was determined to be 85.04 KJ/mol.


2015 ◽  
Vol 2015 ◽  
pp. 1-6
Author(s):  
Romario J. da Silva ◽  
Nara C. de Souza ◽  
Josmary R. Silva

We report on the investigation of the influence of UV-B radiation (306 nm) on the salicylic acid mixed with poly(allylamine hydrochloride), PAH, in aqueous solution. UV-Vis spectra versus irradiation time reveal kinetics of photoproducts formation. At pH 9 and 10 are found a growth regime and another of decay of photoproducts formation. In addition, the growth does not depend on temperature, whereas the decay showed a significant dependence on this parameter suggesting a thermally activated process. These processes were well fitted with first-order exponential functions.


2016 ◽  
Vol 47 (10) ◽  
pp. 5234-5241 ◽  
Author(s):  
Sima Alikhanzadeh-Arani ◽  
Mohammad Almasi-Kashi ◽  
Zahra Pezeshki-Nejad ◽  
Abdolali Ramazani ◽  
Masoud Salavati-Niasari

2018 ◽  
Vol 5 (3) ◽  
Author(s):  
Andrew Smerald ◽  
Frédéric Mila

We study the triangular-lattice Ising model with dipolar interactions, inspired by its realisation in artificial arrays of nanomagnets. We show that a classical spin-liquid forms at intermediate temperatures, and that its behaviour can be tuned by temperature and/or a small lattice distortion between a string Luttinger liquid and a domain-wall-network state. At low temperature there is a transition into a magnetically ordered phase, which can be first-order or continous with a crossover in the critical behaviour between Pokrovsky-Talapov and 2D-Ising universality. When the Pokrovsky-Talapov criticality dominates, the transition is essentially of the Kasteleyn type.


1996 ◽  
Vol 452 ◽  
Author(s):  
Easwar Srinivasan ◽  
Jeremy S. Bordeaux ◽  
Gregory N. Parsons

AbstractIn situ mass spectroscopy is used to monitor and analyze the hydrogen elimination reaction products during cyclical exposure of thin films of amorphous silicon to a flux of atomic deuterium. Mass spectroscopy results that atomic deuterium etches deposited silicon forming SiD4 and abstracts hydrogen bonded to silicon in the film to form HD. The relative signal intensities show that abstraction is the primary hydrogen elimination mechanism. The energy of activation for the abstraction reaction is obtained from the mass spectroscopy signals through a first order kinetic analysis and is found to be approximately zero, indicating that abstraction is not thermally activated.


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