scholarly journals Entropy change of biological dynamics in COPD

2017 ◽  
Vol Volume 12 ◽  
pp. 2997-3005 ◽  
Author(s):  
Yu Jin ◽  
Chang Chen ◽  
Zhixin Cao ◽  
Baoqing Sun ◽  
Iek Long Lo ◽  
...  
Keyword(s):  
Entropy Change ◽  
Biological Dynamics

scholarly journals Entropy Change of Biological Dynamics in Asthmatic Patients and Its Diagnostic Value in Individualized Treatment: A Systematic Review

Entropy ◽  
2018 ◽  
Vol 20 (6) ◽  
pp. 402 ◽  
Author(s):  
Shixue Sun ◽  
Yu Jin ◽  
Chang Chen ◽  
Baoqing Sun ◽  
Zhixin Cao ◽  
...  
Keyword(s):  
Systematic Review ◽  
Entropy Change ◽  
Diagnostic Value ◽  
Individualized Treatment ◽  
Asthmatic Patients ◽  
Biological Dynamics

Breakthrough analysis for hexavalent chromium removal from drinking water in a fixed bed column

2009 ◽  
Vol 9 (6) ◽  
pp. 661-670 ◽  
Author(s):  
S. P. Dubey ◽  
K. Gopal
Keyword(s):  
Aqueous Solution ◽  
Hexavalent Chromium ◽  
Fixed Bed ◽  
Entropy Change ◽  
Spectroscopic Technique ◽  
Fixed Bed Column ◽  
Chromium Vi ◽  
Fixed Bed Adsorption ◽  
Optimal Column ◽  
Eucalyptus Bark

The activated carbon of Eucalyptus globulus was tested for their effectiveness in removing hexavalent chromium from aqueous solution using column experiments. Result revealed that adsorption of chromium(VI) on eucalyptus bark carbon was endothermic in nature. Thermodynamic parameters such as the entropy change, enthalpy change and Gibbs free energy change were found to be 1.39 kJ mol−1 K−1, 1.08 kJ mol−1 and −3.85 kJ mol−1, respectively. Different chromium concentrations were used for the fixed bed adsorption studies. The pre- and post-treated adsorbents were characterized using a FTIR spectroscopic technique. It was concluded that Eucalyptus bark carbon column could be used effectively for removal of hexavalent chromium from aqueous solution at optimal column conditions. This study showed that this biological material is potential adsorbent of Cr(VI) from water.

scholarly journals Effective Magnetic MOFs Adsorbent for the Removal of Bisphenol A, Tetracycline, Congo Red and Methylene Blue Pollutions

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1917
Author(s):  
Guangpu Zhang ◽  
Rong Wo ◽  
Zhe Sun ◽  
Gazi Hao ◽  
Guigao Liu ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Electron Microscope ◽  
Bisphenol A ◽  
Congo Red ◽  
Reduction Process ◽  
Entropy Change ◽  
Potential Candidate ◽  
Order Kinetic ◽  
Adsorption Processes ◽  
Infrared Spectrometer

A magnetic metal−organic frameworks adsorbent (Fe3O4@MIL-53(Al)) was prepared by a typical solvothermal method for the removal of bisphenol A (BPA), tetracycline (TC), congo red (CR), and methylene blue (MB). The prepared Fe3O4@MIL-53(Al) composite adsorbent was well characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD), and fourier transform infrared spectrometer (FTIR). The influence of adsorbent quantity, adsorption time, pH and ionic strength on the adsorption of the mentioned pollutants were also studied by a UV/Vis spectrophotometer. The adsorption capacities were found to be 160.9 mg/g for BPA, 47.8 mg/g for TC, 234.4 mg/g for CR, 70.8 mg/g for MB, respectively, which is superior to the other reported adsorbents. The adsorption of BPA, TC, and CR were well-fitted by the Langmuir adsorption isotherm model, while MB followed the Freundlich model, while the adsorption kinetics data of all pollutants followed the pseudo-second-order kinetic models. The thermodynamic values, including the enthalpy change (ΔH°), the Gibbs free energy change (ΔG°), and entropy change (ΔS°), showed that the adsorption processes were spontaneous and exothermic entropy-reduction process for BPA, but spontaneous and endothermic entropy-increasing processes for the others. The Fe3O4@MIL-53(Al) was also found to be easily separated after external magnetic field, can be a potential candidate for future water treatment.

scholarly journals Insight into the mechanism of thermostabilization of GH10 xylanase from Bacillus sp. strain TAR-1 by the mutation of S92 to E

2021 ◽  
Vol 85 (2) ◽  
pp. 386-390
Author(s):  
Manami Suzuki ◽  
Teisuke Takita ◽  
Kohei Kuwata ◽  
Kota Nakatani ◽  
Tongyang Li ◽  
...  
Keyword(s):  
Amino Acid ◽  
Thermodynamic Analysis ◽  
Thermal Inactivation ◽  
Entropy Change ◽  
Crystallographic Analysis ◽  
Bacillus Sp ◽  
Amino Acid Residues ◽  
Gh10 Xylanase ◽  
Insight Into

ABSTRACT The mechanism of thermostabilization of GH10 xylanase, XynR, from Bacillus sp. strain TAR-1 by the mutation of S92 to E was investigated. Thermodynamic analysis revealed that thermostabilization was driven by the decrease in entropy change of activation for thermal inactivation. Crystallographic analysis suggested that this mutation suppressed the fluctuation of the amino acid residues at position 92-95.

scholarly journals The Carnot Cycle, Reversibility and Entropy

Entropy ◽  
2021 ◽  
Vol 23 (7) ◽  
pp. 810
Author(s):  
David Sands
Keyword(s):  
Irreversible Process ◽  
Entropy Change ◽  
External Pressure ◽  
Step Change ◽  
Equilibrium States ◽  
Rate Equations ◽  
Carnot Cycle ◽  
Work Processes ◽  
Reversible Process ◽  
External Conditions

The Carnot cycle and the attendant notions of reversibility and entropy are examined. It is shown how the modern view of these concepts still corresponds to the ideas Clausius laid down in the nineteenth century. As such, they reflect the outmoded idea, current at the time, that heat is motion. It is shown how this view of heat led Clausius to develop the entropy of a body based on the work that could be performed in a reversible process rather than the work that is actually performed in an irreversible process. In consequence, Clausius built into entropy a conflict with energy conservation, which is concerned with actual changes in energy. In this paper, reversibility and irreversibility are investigated by means of a macroscopic formulation of internal mechanisms of damping based on rate equations for the distribution of energy within a gas. It is shown that work processes involving a step change in external pressure, however small, are intrinsically irreversible. However, under idealised conditions of zero damping the gas inside a piston expands and traces out a trajectory through the space of equilibrium states. Therefore, the entropy change due to heat flow from the reservoir matches the entropy change of the equilibrium states. This trajectory can be traced out in reverse as the piston reverses direction, but if the external conditions are adjusted appropriately, the gas can be made to trace out a Carnot cycle in P-V space. The cycle is dynamic as opposed to quasi-static as the piston has kinetic energy equal in difference to the work performed internally and externally.

scholarly journals Giant room temperature elastocaloric effect in metal-free thin-film perovskites

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Cheng Li ◽  
Yu Hui Huang ◽  
Jian-Jun Wang ◽  
Bo Wang ◽  
Yong Jun Wu ◽  
...  
Keyword(s):  
Thin Films ◽  
Solid State ◽  
Room Temperature ◽  
Entropy Change ◽  
Stress Change ◽  
Chemical Doping ◽  
Metal Free ◽  
Organic Ferroelectrics ◽  
Potential Applications ◽  
Unit Stress

AbstractSolid-state refrigeration which is environmentally benign has attracted considerable attention. Mechanocaloric (mC) materials, in which the phase transitions can be induced by mechanical stresses, represent one of the most promising types of solid-state caloric materials. Herein, we have developed a thermodynamic phenomenological model and predicted extraordinarily large elastocaloric (eC) strengths for the (111)-oriented metal-free perovskite ferroelectric [MDABCO](NH4)I3 thin-films. The predicted room temperature isothermal eC ΔSeC/Δσ (eC entropy change under unit stress change) and adiabatic eC ΔTeC/Δσ (eC temperature change under unit stress change) for [MDABCO](NH4)I3 are −60.0 J K−1 kg−1 GPa−1 and 17.9 K GPa−1, respectively, which are 20 times higher than the traditional ferroelectric oxides such as BaTiO3 thin films. We have also demonstrated that the eC performance can be improved by reducing the Young’s modulus or enhancing the thermal expansion coefficient (which could be realized through chemical doping, etc.). We expect these discoveries to spur further interest in the potential applications of metal-free organic ferroelectrics materials towards next-generation eC refrigeration devices.

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