Calorimetric measurements of the Li–Zn system. Direct reaction method and mixing enthalpy

2016 ◽  
Vol 98 ◽  
pp. 111-117 ◽  
Author(s):  
A. Dębski ◽  
W. Gąsior
Keyword(s):  
Mixing Enthalpy ◽  
Direct Reaction ◽  
Reaction Method ◽  
Calorimetric Measurements

scholarly journals Calorimetric Measurements of Ga-Li System by Direct Reaction Method

2017 ◽  
Vol 62 (2) ◽  
pp. 919-926 ◽  
Author(s):  
A. Dębski
Keyword(s):  
Formation Enthalpy ◽  
Intermetallic Phases ◽  
Direct Reaction ◽  
Miedema Model ◽  
X Ray Diffraction ◽  
Reaction Method ◽  
X Ray ◽  
Calorimetric Measurements ◽  
Experimental Values

AbstractThe direct reaction calorimetric method was used for the determination of the formation enthalpy of alloys which concentrations correspond to the: Ga7Li2, Ga9Li5, GaLi, Ga4Li5, Ga2Li3, and GaLi2intermetallic phases. The obtained experimental values of the formation enthalpy were: −18.1 ±0.8 kJ/mol at., −26.5 ±0.3 kJ/mol at., −34.7 ±0.3 kJ/mol at., −33.5 ±0.5 kJ/mol at., −32.8 ±0.3 kJ/mol at. and −24.6 ±1.4 kJ/mol at., respectively. After the calorimetric measurements, all the samples were checked by way of X-ray diffraction investigations to confirm the structure of the measured alloys. All the measured values of the formation enthalpy of the Ga-Li alloys were compared with literature data and the data calculated with use of the Miedema model.

Uranium(VI) Uptake by Synthetic Calcium Silicate Hydrates

2008 ◽  
Vol 1107 ◽  
Author(s):  
J. Tits ◽  
T. Fujita ◽  
M. Tsukamoto ◽  
E. Wieland
Keyword(s):  
Solid Phase ◽  
Near Field ◽  
Sorption Isotherms ◽  
Alkaline Solutions ◽  
Precipitation Process ◽  
Direct Reaction ◽  
Reaction Method ◽  
Calcium Silicate Hydrates ◽  
Chemical Conditions ◽  
Co Precipitation

AbstractThe immobilization of U(VI) by C-S-H phases under conditions relevant for the cementitious near field of a repository for radioactive waste has been investigated. C-S-H phases have been synthesized using two different procedures: the “direct reaction” method and the “solution reaction” method.The stabilities of alkaline solutions of U(VI) (presence of precipitates or colloidal material) were studied prior to sorption and co-precipitation tests in order to determine the experimental U(VI) solubility limits. These U(VI) solubility limits were compared with the U(VI) solubilities obtained from thermodynamic speciation calculations assuming the presence of combinations of different solid U(VI) phases. The solid phase controlling U(VI) solubility in the present experiments was found to be CaUO4(s).The U(VI) uptake kinetics and sorption isotherms on C-S-H phases with different C:S ratios were determined under various chemical conditions; e.g., sorption and co-precipitation experiments and different pH’s. U(VI) was found to sorb fast and very strongly on C-S-H phases with distribution ratios (Rd values) ranging in value between 103 L kg-1 and 106 L kg-1. Both sorption and co-precipitation experiments resulted in Rd values which were very similar, thus indicating that no additional sorption sites for U(VI) were generated in the co-precipitation process. Furthermore, C-S-H synthesis procedures did not have a significant influence on U(VI) uptake. The U(VI) sorption isotherms were found to be non-linear, and further, increasing Ca concentrations resulted in increasing U(VI) uptake. The latter observation suggests that U(VI) uptake is controlled by a solubility-limiting process, while the former observation further indicates that pure Ca-uranate is not the solubility-limiting phase. It is proposed that a solid solution containing Ca and could control U(VI) uptake by C-S-H phases.

Synthesis and Characterization of Complex from K4[Co(SCN)6], Zinc(II) Chloride and Quinoline as Electrode Material of K-Ion Battery

2020 ◽  
Vol 851 ◽  
pp. 3-8
Author(s):  
Ade Rifaldi ◽  
Fariati ◽  
Husni Wahyu Wijaya ◽  
Wiwin Dwi Jayanti ◽  
Stephane Golhen ◽  
...  
Keyword(s):  
Cyclic Voltammetry ◽  
Prussian Blue ◽  
Electrode Material ◽  
Reduction Potential ◽  
Synthesis And Characterization ◽  
Direct Reaction ◽  
Reaction Method ◽  
Ft Ir

Prussian Blue Like (PBL) compounds that are potentially used as K-Ion Battery (KIB) electrodes have been synthesized from zinc(II) chloride and quinoline (Qn) precursors combining melting and direct reaction method. The formed K2[Zn(Qn)2][Co(SCN)6] compounds melt in range 179-181°C with conductivity value reaches 468 μS/cm. Thiocyanate and quinoline ligands were characterized using FT-IR and UV-Vis spectrometry. The cyclic voltammetry of the formed compounds showed the reduction potential up to -0.34 V (versus AgCl/Ag).

Preparation of zinc layered hydroxide–chloroacetate nanohybrid using direct reaction method

2016 ◽  
Vol 21 (6) ◽  
pp. 396-400 ◽  
Author(s):  
Norhayati Hashim ◽  
Zuhailimuna Muda ◽  
Sharifah N. M. Sharif ◽  
Illyas M. Isa ◽  
Noorshida M. Ali ◽  
...  
Keyword(s):  
Direct Reaction ◽  
Reaction Method ◽  
Zinc Layered Hydroxide

Theoretical and Experimental Evaluation of the Effect of Fluorinated Substituent on the Topological Landscape and Thermodynamic Stability of Zeolitic Imidazolate Framework Polymorphs

2018 ◽  
Author(s):  
Mihails Arhangelskis ◽  
Athanassis Katsenis ◽  
Novendra Novendra ◽  
Zamirbek Akimbekov ◽  
Dayaker Gandrath ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Mechanochemical Synthesis ◽  
Thermodynamic Stability ◽  
Experimental Evaluation ◽  
Density Functional ◽  
Theoretical Calculations ◽  
Zeolitic Imidazolate Framework ◽  
Functional Theory ◽  
Calorimetric Measurements ◽  
And Calorimetry

By combining mechanochemical synthesis and calorimetry with theoretical calculations, we demonstrate that dispersion-corrected periodic density functional theory (DFT) can accurately survey the topological landscape and predict relative energies of polymorphs for a previously inaccessible fluorine-substituted zeolitic imidazolate framework (ZIF). Experimental screening confirmed two out of three theoretically anticipated polymorphs, and the calorimetric measurements provided an excellent match to theoretically calculated energetic difference between them.<br>

Grand-Reaction Method for Simulations of Ionization Equilibria and Ion Partitioning in a Broad Range of pH and Ionic Strength

2019 ◽  
Author(s):  
Jonas Landsgesell ◽  
Oleg Rud ◽  
Pascal Hebbeker ◽  
Raju Lunkad ◽  
Peter Košovan ◽  
...  
Keyword(s):  
Mean Field ◽  
Coarse Grained ◽  
Reactive System ◽  
Acid Base ◽  
Buffer Solution ◽  
Reaction Method ◽  
Ionization Equilibria ◽  
Coarse Grained Simulations ◽  
Ph Range ◽  
Weak Polyelectrolytes

We introduce the grand-reaction method for coarse-grained simulations of acid-base equilibria in a system coupled to a reservoir at a given pH and concentration of added salt. It can be viewed as an extension of the constant-pH method and the reaction ensemble, combining explicit simulations of reactions within the system, and grand-canonical exchange of particles with the reservoir. Unlike the previously introduced methods, the grand-reaction method is applicable to acid-base equilibria in the whole pH range because it avoids known artifacts. However, the method is more general, and can be used for simulations of any reactive system coupled to a reservoir of a known composition. To demonstrate the advantages of the grand-reaction method, we simulated a model system: A solution of weak polyelectrolytes in equilibrium with a buffer solution. By carefully accounting for the exchange of all constituents, the method ensures that all chemical potentials are equal in the system and in the multi-component reservoir. Thus, the grand-reaction method is able to predict non-monotonic swelling of weak polyelectrolytes as a function of pH, that has been known from mean-field predictions and from experiments but has never been observed in coarse-grained simulations. Finally, we outline possible extensions and further generalizations of the method, and provide a set of guidelines to enable safe usage of the method by a broad community of users.<br><br>

INFLUENCE OF MIXING ENTHALPY ON THE MICROSTRUCTURE OF LASER MULTI--LAYER DEPOSITED Ti--6Al--4V ALLOY

2013 ◽  
Vol 48 (2) ◽  
pp. 159-163 ◽  
Author(s):  
Fengying ZHANG ◽  
Hua TAN ◽  
Jing CHEN ◽  
Xin LIN ◽  
Weidong HUANG
Keyword(s):  
Mixing Enthalpy

Formulation of Modified Release Atorvastatin Nanoparticles by Emulsion Interfacial Reaction Method

2015 ◽  
Vol 8 (3) ◽  
pp. 2937-2940
Author(s):  
Sudhakar Sekar ◽  
Shee Sim May
Keyword(s):  
Interfacial Reaction ◽  
Therapeutic Potential ◽  
Chitosan Nanoparticles ◽  
In Vitro Release ◽  
Morphological Characteristics ◽  
Preparation Technique ◽  
Modified Release ◽  
Reaction Method ◽  
Vitro Release

The aim of the study is to formulate a modified release chitosan nanoparticles for the oral delivery of atorvastatin and to study the in vitro release of atorvastatin from chitosan nanoparticles. Atorvastatin-loaded chitosan nanoparticles were prepared with different concentration of cross-linking agent (glutaraldehyde) by emulsion interfacial reaction method. The formed nanoparticles were characterized in terms of size and morphological characteristics by scanning electron microscopy (SEM) and transmission electron microscope (TEM). Spherical and regular nanoparticles with the size range of 100-250nm were formed. Atorvastatin encapsulation efficiency of nanoparticles was found to be highest in ANP3, followed by ANP2 and ANP1. The in vitro release of atorvastatin was studied by membrane diffusion technique. The resulted cumulative percentage of drug released for ANP1, ANP2 and ANP3 were 60.08%, 34.81% and 20.39% respectively. Through this study, the nanoparticles preparation technique has shown to be a promising approach for enhancing the dissolution of hydrophobic drugs like atorvastatin calcium. The application of this novel delivery system offers good therapeutic potential in the management of hypercholesterolemia and dyslipidemia.

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