The relaxation behavior of complex-disordered systems, such as spin glasses, polymers, colloidal suspensions, structural glasses,and granular media, has not been clarified. Theoretical studies show that relaxation in ...The relaxation behavior of complex-disordered systems, such as spin glasses, polymers, colloidal suspensions, structural glasses,and granular media, has not been clarified. Theoretical studies show that relaxation in these systems has a topological origin. In this paper, we focus on the rotational stretched exponential relaxation behavior in complex-disordered systems and introduce a simple phase space model to understand the mechanism of the non-exponential relaxation of these systems. By employing the Monte Carlo simulation method to the model, we obtain the rotational relaxation function as a function of temperature. We show that the relaxation function has a stretched exponential form under the critical temperature while it obeys the Debye law above the critical temperature.展开更多
We studied the effect of titanium dioxide(TiO_(2))nanoparticles(NPs)on dielectric behavior of Naþion-conducting salt-complexed polymer nanocomposite system formed from a binary polymer blend of poly(ethylene oxid...We studied the effect of titanium dioxide(TiO_(2))nanoparticles(NPs)on dielectric behavior of Naþion-conducting salt-complexed polymer nanocomposite system formed from a binary polymer blend of poly(ethylene oxide)(PEO)and polyvinyl pyrrolidone(PVP),with the addition of both sodium metaperiodate(NaIO_(4))at concentration 10 wt.%and TiO_(2) NPs of size10 nm,at concentrations 1,2,3,4 and 5 wt.%.Free standing nanocomposite PEO/PVP/NaIO_(4)/TiO_(2) films(150m)were characterized at room-temperature by analyzing their complex electrical impedance and dielectric spectra in the range 1 Hz–1 MHz.At the concentration of 3 wt.%of TiO_(2) NPs,both ion conductivity and dielectric permittivity of the PEO/PVP/NaIO_(4)/TiO_(2) ion-conducting dielectrics reach an enhancement by more than one order of magnitude as compared to nanoadditive-free case.展开更多
Microalgae cultivation using organic wastewater like kitchen wastewater(KWW)and sewage wastewater(SWW)are recommended for wastewater treatment along with simultaneous biomass production which is a cost effective strat...Microalgae cultivation using organic wastewater like kitchen wastewater(KWW)and sewage wastewater(SWW)are recommended for wastewater treatment along with simultaneous biomass production which is a cost effective strategy.KWW is rich in nutrients which might be an efficient wastewater feedstock for microalgae cultivation to achieve reasonably high biomass yield for energy generation.KWW has not been investigated extensively for microalgae cultivation till now because of high concentration of ammonia as it could inhibit algae growth.In order to make KWW suitable for microalgae growth,a common method is to dilute with water.Hence,in the present study,KWW was diluted with water at dilution ration 1:1 and compared with SWW for microalgae biomass growth,biomass yields and nutrient removal efficiency specifically using Chlorella.Both KWW and SWW showed highest biomass productivity in mixotrophic cultivation mode.The average biomass productivity in SWW was 0.6 g/L which was higher when compared to KWW.Fourier infrared spectroscopy(FTIR)of algal biomass revealed the presence of certain organic compound groups such as eOH,eCOOH,NH_(2),and ■O.It was concluded from the results that Chlorella was very effective in the treatment of KWW,SWW and industrial flue gas on the other hand the biomass obtained is a sustainable green energy source for biofuels.展开更多
The stress relaxation of semi-crystalline nylon 1010 cannot be fitted by the Kohlrausch-Williams-Watts formula when the experiments were performed at pre-yielding regime below the glass transition temperature.We study...The stress relaxation of semi-crystalline nylon 1010 cannot be fitted by the Kohlrausch-Williams-Watts formula when the experiments were performed at pre-yielding regime below the glass transition temperature.We study this problem and identify the two-step mechanism of stress relaxation.At short time scale,relaxation is fast,dominated by stress biased thermal fluctuation with a fixed short-range length scale(activation volume).At long time scale,relaxation is slow due to the emergence of a cooperative long-range length scale determined by the stress fluctuation.The cooperative length scale is proportional to the reciprocal of stress and the amplitude of stress fluctuation is the product of stress and activation volume.Based on this two-step mechanism,we propose a new kinetics equation to capture the stress relaxation effectively,where the short time relaxation is described by an Eyring-like local activation and the long-time relaxation is captured by a cooperative excitation process resorting to an extension from the random first order transition theory.Our equation fits the experimental data well and can serve as a model to guide the related experiments of relaxation processes in crystalline solids.展开更多
基金Project supported by Istanbul University(Grant Nos.28432 and 45662)
文摘The relaxation behavior of complex-disordered systems, such as spin glasses, polymers, colloidal suspensions, structural glasses,and granular media, has not been clarified. Theoretical studies show that relaxation in these systems has a topological origin. In this paper, we focus on the rotational stretched exponential relaxation behavior in complex-disordered systems and introduce a simple phase space model to understand the mechanism of the non-exponential relaxation of these systems. By employing the Monte Carlo simulation method to the model, we obtain the rotational relaxation function as a function of temperature. We show that the relaxation function has a stretched exponential form under the critical temperature while it obeys the Debye law above the critical temperature.
基金supported by the Ministry of Education and Science of Bulgaria(MESB),through the National Science Fund of Bulgaria(research project No.KP-06-N58/6/2021)Todor Vlakhov gratefully acknowledges the support by the MESB under the National Research Programme,Young scientists and postdoctoral researches-2 approved by DCM 206/07.04.2022.
文摘We studied the effect of titanium dioxide(TiO_(2))nanoparticles(NPs)on dielectric behavior of Naþion-conducting salt-complexed polymer nanocomposite system formed from a binary polymer blend of poly(ethylene oxide)(PEO)and polyvinyl pyrrolidone(PVP),with the addition of both sodium metaperiodate(NaIO_(4))at concentration 10 wt.%and TiO_(2) NPs of size10 nm,at concentrations 1,2,3,4 and 5 wt.%.Free standing nanocomposite PEO/PVP/NaIO_(4)/TiO_(2) films(150m)were characterized at room-temperature by analyzing their complex electrical impedance and dielectric spectra in the range 1 Hz–1 MHz.At the concentration of 3 wt.%of TiO_(2) NPs,both ion conductivity and dielectric permittivity of the PEO/PVP/NaIO_(4)/TiO_(2) ion-conducting dielectrics reach an enhancement by more than one order of magnitude as compared to nanoadditive-free case.
基金support for carrying research work(order No.DST/IS-STAC/CO2-SR-212/14(G)dated 17.09.2015)Author Dr.D Bhagawan would like to thank the University Grants Commission(UGC),Government of India/Bharat Sarkar,for providing with fund and encouragement to carry out the research work(order No.F./31-1/2017/PDFSS-2017-18-TEL-14164)and Dr.Kavita Verma would like to thank the Department of Biotechnology(DBT)(UGC),Government of India/Bharat Sarkar,for providing funds.
文摘Microalgae cultivation using organic wastewater like kitchen wastewater(KWW)and sewage wastewater(SWW)are recommended for wastewater treatment along with simultaneous biomass production which is a cost effective strategy.KWW is rich in nutrients which might be an efficient wastewater feedstock for microalgae cultivation to achieve reasonably high biomass yield for energy generation.KWW has not been investigated extensively for microalgae cultivation till now because of high concentration of ammonia as it could inhibit algae growth.In order to make KWW suitable for microalgae growth,a common method is to dilute with water.Hence,in the present study,KWW was diluted with water at dilution ration 1:1 and compared with SWW for microalgae biomass growth,biomass yields and nutrient removal efficiency specifically using Chlorella.Both KWW and SWW showed highest biomass productivity in mixotrophic cultivation mode.The average biomass productivity in SWW was 0.6 g/L which was higher when compared to KWW.Fourier infrared spectroscopy(FTIR)of algal biomass revealed the presence of certain organic compound groups such as eOH,eCOOH,NH_(2),and ■O.It was concluded from the results that Chlorella was very effective in the treatment of KWW,SWW and industrial flue gas on the other hand the biomass obtained is a sustainable green energy source for biofuels.
基金financially supported by the National Natural Science Foundation of China (Nos.21873054,21774131 and 21544007)the National Natural Science Foundation of China (Nos.U1862205 and 51673110)China Petroleum & Chemical Corporation for financial support。
文摘The stress relaxation of semi-crystalline nylon 1010 cannot be fitted by the Kohlrausch-Williams-Watts formula when the experiments were performed at pre-yielding regime below the glass transition temperature.We study this problem and identify the two-step mechanism of stress relaxation.At short time scale,relaxation is fast,dominated by stress biased thermal fluctuation with a fixed short-range length scale(activation volume).At long time scale,relaxation is slow due to the emergence of a cooperative long-range length scale determined by the stress fluctuation.The cooperative length scale is proportional to the reciprocal of stress and the amplitude of stress fluctuation is the product of stress and activation volume.Based on this two-step mechanism,we propose a new kinetics equation to capture the stress relaxation effectively,where the short time relaxation is described by an Eyring-like local activation and the long-time relaxation is captured by a cooperative excitation process resorting to an extension from the random first order transition theory.Our equation fits the experimental data well and can serve as a model to guide the related experiments of relaxation processes in crystalline solids.
